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git/pack-bitmap.c

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pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "diff.h"
#include "revision.h"
#include "progress.h"
#include "list-objects.h"
#include "pack.h"
#include "pack-bitmap.h"
#include "pack-revindex.h"
#include "pack-objects.h"
pack: move open_pack_index(), parse_pack_index() alloc_packed_git() in packfile.c is duplicated from sha1_file.c. In a subsequent commit, alloc_packed_git() will be removed from sha1_file.c. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-19 01:20:19 +03:00
#include "packfile.h"
object-store: move packed_git and packed_git_mru to object store In a process with multiple repositories open, packfile accessors should be associated to a single repository and not shared globally. Move packed_git and packed_git_mru into the_repository and adjust callers to reflect this. [nd: while at there, wrap access to these two fields in get_packed_git() and get_packed_git_mru(). This allows us to lazily initialize these fields without caller doing that explicitly] Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-23 20:20:59 +03:00
#include "repository.h"
#include "object-store.h"
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
/*
* An entry on the bitmap index, representing the bitmap for a given
* commit.
*/
struct stored_bitmap {
pack-bitmap: convert struct stored_bitmap to object_id Convert struct stored_bitmap to use struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:55 +03:00
struct object_id oid;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct ewah_bitmap *root;
struct stored_bitmap *xor;
int flags;
};
/*
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
* The active bitmap index for a repository. By design, repositories only have
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
* a single bitmap index available (the index for the biggest packfile in
* the repository), since bitmap indexes need full closure.
*
* If there is more than one bitmap index available (e.g. because of alternates),
* the active bitmap index is the largest one.
*/
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_index {
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
/* Packfile to which this bitmap index belongs to */
struct packed_git *pack;
/*
* Mark the first `reuse_objects` in the packfile as reused:
* they will be sent as-is without using them for repacking
* calculations
*/
uint32_t reuse_objects;
/* mmapped buffer of the whole bitmap index */
unsigned char *map;
size_t map_size; /* size of the mmaped buffer */
size_t map_pos; /* current position when loading the index */
/*
* Type indexes.
*
* Each bitmap marks which objects in the packfile are of the given
* type. This provides type information when yielding the objects from
* the packfile during a walk, which allows for better delta bases.
*/
struct ewah_bitmap *commits;
struct ewah_bitmap *trees;
struct ewah_bitmap *blobs;
struct ewah_bitmap *tags;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
/* Map from object ID -> `stored_bitmap` for all the bitmapped commits */
kh_oid_map_t *bitmaps;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
/* Number of bitmapped commits */
uint32_t entry_count;
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
/* If not NULL, this is a name-hash cache pointing into map. */
pack-bitmap: implement optional name_hash cache When we use pack bitmaps rather than walking the object graph, we end up with the list of objects to include in the packfile, but we do not know the path at which any tree or blob objects would be found. In a recently packed repository, this is fine. A fetch would use the paths only as a heuristic in the delta compression phase, and a fully packed repository should not need to do much delta compression. As time passes, though, we may acquire more objects on top of our large bitmapped pack. If clients fetch frequently, then they never even look at the bitmapped history, and all works as usual. However, a client who has not fetched since the last bitmap repack will have "have" tips in the bitmapped history, but "want" newer objects. The bitmaps themselves degrade gracefully in this circumstance. We manually walk the more recent bits of history, and then use bitmaps when we hit them. But we would also like to perform delta compression between the newer objects and the bitmapped objects (both to delta against what we know the user already has, but also between "new" and "old" objects that the user is fetching). The lack of pathnames makes our delta heuristics much less effective. This patch adds an optional cache of the 32-bit name_hash values to the end of the bitmap file. If present, a reader can use it to match bitmapped and non-bitmapped names during delta compression. Here are perf results for p5310: Test origin/master HEAD^ HEAD ------------------------------------------------------------------------------------------------- 5310.2: repack to disk 36.81(37.82+1.43) 47.70(48.74+1.41) +29.6% 47.75(48.70+1.51) +29.7% 5310.3: simulated clone 30.78(29.70+2.14) 1.08(0.97+0.10) -96.5% 1.07(0.94+0.12) -96.5% 5310.4: simulated fetch 3.16(6.10+0.08) 3.54(10.65+0.06) +12.0% 1.70(3.07+0.06) -46.2% 5310.6: partial bitmap 36.76(43.19+1.81) 6.71(11.25+0.76) -81.7% 4.08(6.26+0.46) -88.9% You can see that the time spent on an incremental fetch goes down, as our delta heuristics are able to do their work. And we save time on the partial bitmap clone for the same reason. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:45 +04:00
uint32_t *hashes;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
/*
* Extended index.
*
* When trying to perform bitmap operations with objects that are not
* packed in `pack`, these objects are added to this "fake index" and
* are assumed to appear at the end of the packfile for all operations
*/
struct eindex {
struct object **objects;
uint32_t *hashes;
uint32_t count, alloc;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
kh_oid_pos_t *positions;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
} ext_index;
/* Bitmap result of the last performed walk */
struct bitmap *result;
pack-bitmap: save "have" bitmap from walk When we do a bitmap walk, we save the result, which represents (WANTs & ~HAVEs); i.e., every object we care about visiting in our walk. However, we throw away the haves bitmap, which can sometimes be useful, too. Save it and provide an access function so code which has performed a walk can query it. A few notes on the accessor interface: - the bitmap code calls these "haves" because it grew out of the want/have negotiation for fetches. But really, these are simply the objects that would be flagged UNINTERESTING in a regular traversal. Let's use that more universal nomenclature for the external module interface. We may want to change the internal naming inside the bitmap code, but that's outside the scope of this patch. - it still uses a bare "sha1" rather than "oid". That's true of all of the bitmap code. And in this particular instance, our caller in pack-objects is dealing with the bare sha1 that comes from a packed REF_DELTA (we're pointing directly to the mmap'd pack on disk). That's something we'll have to deal with as we transition to a new hash, but we can wait and see how the caller ends up being fixed and adjust this interface accordingly. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 22:07:01 +03:00
/* "have" bitmap from the last performed walk */
struct bitmap *haves;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
/* Version of the bitmap index */
unsigned int version;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
};
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
static struct ewah_bitmap *lookup_stored_bitmap(struct stored_bitmap *st)
{
struct ewah_bitmap *parent;
struct ewah_bitmap *composed;
if (st->xor == NULL)
return st->root;
composed = ewah_pool_new();
parent = lookup_stored_bitmap(st->xor);
ewah_xor(st->root, parent, composed);
ewah_pool_free(st->root);
st->root = composed;
st->xor = NULL;
return composed;
}
/*
* Read a bitmap from the current read position on the mmaped
* index, and increase the read position accordingly
*/
static struct ewah_bitmap *read_bitmap_1(struct bitmap_index *index)
{
struct ewah_bitmap *b = ewah_pool_new();
ewah: adjust callers of ewah_read_mmap() The return value of ewah_read_mmap() is now an ssize_t, since we could (in theory) process up to 32GB of data. This would never happen in practice, but a corrupt or malicious .bitmap or index file could convince us to do so. Let's make sure that we don't stuff the value into an int, which would cause us to incorrectly move our pointer forward. We'd always move too little, since negative values are used for reporting errors. So the worst case is just that we end up reporting a corrupt file, not an out-of-bounds read. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-15 06:44:43 +03:00
ssize_t bitmap_size = ewah_read_mmap(b,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
index->map + index->map_pos,
index->map_size - index->map_pos);
if (bitmap_size < 0) {
error("Failed to load bitmap index (corrupted?)");
ewah_pool_free(b);
return NULL;
}
index->map_pos += bitmap_size;
return b;
}
static int load_bitmap_header(struct bitmap_index *index)
{
struct bitmap_disk_header *header = (void *)index->map;
pack-bitmap: switch hard-coded constants to the_hash_algo Switch two hard-coded uses of 20 to references to the_hash_algo. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:57 +03:00
if (index->map_size < sizeof(*header) + the_hash_algo->rawsz)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
return error("Corrupted bitmap index (missing header data)");
if (memcmp(header->magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE)) != 0)
return error("Corrupted bitmap index file (wrong header)");
index->version = ntohs(header->version);
if (index->version != 1)
return error("Unsupported version for bitmap index file (%d)", index->version);
/* Parse known bitmap format options */
{
uint32_t flags = ntohs(header->options);
if ((flags & BITMAP_OPT_FULL_DAG) == 0)
return error("Unsupported options for bitmap index file "
"(Git requires BITMAP_OPT_FULL_DAG)");
pack-bitmap: implement optional name_hash cache When we use pack bitmaps rather than walking the object graph, we end up with the list of objects to include in the packfile, but we do not know the path at which any tree or blob objects would be found. In a recently packed repository, this is fine. A fetch would use the paths only as a heuristic in the delta compression phase, and a fully packed repository should not need to do much delta compression. As time passes, though, we may acquire more objects on top of our large bitmapped pack. If clients fetch frequently, then they never even look at the bitmapped history, and all works as usual. However, a client who has not fetched since the last bitmap repack will have "have" tips in the bitmapped history, but "want" newer objects. The bitmaps themselves degrade gracefully in this circumstance. We manually walk the more recent bits of history, and then use bitmaps when we hit them. But we would also like to perform delta compression between the newer objects and the bitmapped objects (both to delta against what we know the user already has, but also between "new" and "old" objects that the user is fetching). The lack of pathnames makes our delta heuristics much less effective. This patch adds an optional cache of the 32-bit name_hash values to the end of the bitmap file. If present, a reader can use it to match bitmapped and non-bitmapped names during delta compression. Here are perf results for p5310: Test origin/master HEAD^ HEAD ------------------------------------------------------------------------------------------------- 5310.2: repack to disk 36.81(37.82+1.43) 47.70(48.74+1.41) +29.6% 47.75(48.70+1.51) +29.7% 5310.3: simulated clone 30.78(29.70+2.14) 1.08(0.97+0.10) -96.5% 1.07(0.94+0.12) -96.5% 5310.4: simulated fetch 3.16(6.10+0.08) 3.54(10.65+0.06) +12.0% 1.70(3.07+0.06) -46.2% 5310.6: partial bitmap 36.76(43.19+1.81) 6.71(11.25+0.76) -81.7% 4.08(6.26+0.46) -88.9% You can see that the time spent on an incremental fetch goes down, as our delta heuristics are able to do their work. And we save time on the partial bitmap clone for the same reason. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:45 +04:00
if (flags & BITMAP_OPT_HASH_CACHE) {
pack-bitmap: switch hard-coded constants to the_hash_algo Switch two hard-coded uses of 20 to references to the_hash_algo. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:57 +03:00
unsigned char *end = index->map + index->map_size - the_hash_algo->rawsz;
pack-bitmap: implement optional name_hash cache When we use pack bitmaps rather than walking the object graph, we end up with the list of objects to include in the packfile, but we do not know the path at which any tree or blob objects would be found. In a recently packed repository, this is fine. A fetch would use the paths only as a heuristic in the delta compression phase, and a fully packed repository should not need to do much delta compression. As time passes, though, we may acquire more objects on top of our large bitmapped pack. If clients fetch frequently, then they never even look at the bitmapped history, and all works as usual. However, a client who has not fetched since the last bitmap repack will have "have" tips in the bitmapped history, but "want" newer objects. The bitmaps themselves degrade gracefully in this circumstance. We manually walk the more recent bits of history, and then use bitmaps when we hit them. But we would also like to perform delta compression between the newer objects and the bitmapped objects (both to delta against what we know the user already has, but also between "new" and "old" objects that the user is fetching). The lack of pathnames makes our delta heuristics much less effective. This patch adds an optional cache of the 32-bit name_hash values to the end of the bitmap file. If present, a reader can use it to match bitmapped and non-bitmapped names during delta compression. Here are perf results for p5310: Test origin/master HEAD^ HEAD ------------------------------------------------------------------------------------------------- 5310.2: repack to disk 36.81(37.82+1.43) 47.70(48.74+1.41) +29.6% 47.75(48.70+1.51) +29.7% 5310.3: simulated clone 30.78(29.70+2.14) 1.08(0.97+0.10) -96.5% 1.07(0.94+0.12) -96.5% 5310.4: simulated fetch 3.16(6.10+0.08) 3.54(10.65+0.06) +12.0% 1.70(3.07+0.06) -46.2% 5310.6: partial bitmap 36.76(43.19+1.81) 6.71(11.25+0.76) -81.7% 4.08(6.26+0.46) -88.9% You can see that the time spent on an incremental fetch goes down, as our delta heuristics are able to do their work. And we save time on the partial bitmap clone for the same reason. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:45 +04:00
index->hashes = ((uint32_t *)end) - index->pack->num_objects;
}
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
index->entry_count = ntohl(header->entry_count);
pack-bitmap: make bitmap header handling hash agnostic Increase the checksum field in struct bitmap_disk_header to be GIT_MAX_RAWSZ bytes in length and ensure that we hash the proper number of bytes out when computing the bitmap checksum. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:54 +03:00
index->map_pos += sizeof(*header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
return 0;
}
static struct stored_bitmap *store_bitmap(struct bitmap_index *index,
struct ewah_bitmap *root,
pack-bitmap: replace sha1_to_hex Replace the uses of sha1_to_hex in the pack bitmap code with hash_to_hex to allow the use of SHA-256 as well. Rename a few variables since they are no longer limited to SHA-1. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:56 +03:00
const unsigned char *hash,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct stored_bitmap *xor_with,
int flags)
{
struct stored_bitmap *stored;
khiter_t hash_pos;
int ret;
stored = xmalloc(sizeof(struct stored_bitmap));
stored->root = root;
stored->xor = xor_with;
stored->flags = flags;
pack-bitmap: replace sha1_to_hex Replace the uses of sha1_to_hex in the pack bitmap code with hash_to_hex to allow the use of SHA-256 as well. Rename a few variables since they are no longer limited to SHA-1. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:56 +03:00
oidread(&stored->oid, hash);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
hash_pos = kh_put_oid_map(index->bitmaps, stored->oid, &ret);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
/* a 0 return code means the insertion succeeded with no changes,
* because the SHA1 already existed on the map. this is bad, there
* shouldn't be duplicated commits in the index */
if (ret == 0) {
pack-bitmap: replace sha1_to_hex Replace the uses of sha1_to_hex in the pack bitmap code with hash_to_hex to allow the use of SHA-256 as well. Rename a few variables since they are no longer limited to SHA-1. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:56 +03:00
error("Duplicate entry in bitmap index: %s", hash_to_hex(hash));
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
return NULL;
}
kh_value(index->bitmaps, hash_pos) = stored;
return stored;
}
pack-bitmap: do not use gcc packed attribute The "__attribute__" flag may be a noop on some compilers. That's OK as long as the code is correct without the attribute, but in this case it is not. We would typically end up with a struct that is 2 bytes too long due to struct padding, breaking both reading and writing of bitmaps. Instead of marshalling the data in a struct, let's just provide helpers for reading and writing the appropriate types. Besides being correct on all platforms, the result is more efficient and simpler to read. Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-27 08:24:01 +03:00
static inline uint32_t read_be32(const unsigned char *buffer, size_t *pos)
{
uint32_t result = get_be32(buffer + *pos);
(*pos) += sizeof(result);
return result;
}
static inline uint8_t read_u8(const unsigned char *buffer, size_t *pos)
{
return buffer[(*pos)++];
}
pack-bitmaps: plug memory leak, fix allocation size for recent_bitmaps Use an automatic variable for recent_bitmaps, an array of pointers. This way we don't allocate too much and don't have to free the memory at the end. The old code over-allocated because it reserved enough memory to store all of the structs it is only pointing to and never freed it. 160 64-bit pointers take up 1280 bytes, which is not too much to be placed on the stack. MAX_XOR_OFFSET is turned into a preprocessor constant to make it constant enough for use in an non-variable array declaration. Noticed-by: Stefan Beller <stefanbeller@gmail.com> Suggested-by: Jeff King <peff@peff.net> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-19 02:24:09 +03:00
#define MAX_XOR_OFFSET 160
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
static int load_bitmap_entries_v1(struct bitmap_index *index)
{
uint32_t i;
pack-bitmaps: plug memory leak, fix allocation size for recent_bitmaps Use an automatic variable for recent_bitmaps, an array of pointers. This way we don't allocate too much and don't have to free the memory at the end. The old code over-allocated because it reserved enough memory to store all of the structs it is only pointing to and never freed it. 160 64-bit pointers take up 1280 bytes, which is not too much to be placed on the stack. MAX_XOR_OFFSET is turned into a preprocessor constant to make it constant enough for use in an non-variable array declaration. Noticed-by: Stefan Beller <stefanbeller@gmail.com> Suggested-by: Jeff King <peff@peff.net> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-19 02:24:09 +03:00
struct stored_bitmap *recent_bitmaps[MAX_XOR_OFFSET] = { NULL };
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
for (i = 0; i < index->entry_count; ++i) {
int xor_offset, flags;
struct ewah_bitmap *bitmap = NULL;
struct stored_bitmap *xor_bitmap = NULL;
uint32_t commit_idx_pos;
const unsigned char *sha1;
pack-bitmap: do not use gcc packed attribute The "__attribute__" flag may be a noop on some compilers. That's OK as long as the code is correct without the attribute, but in this case it is not. We would typically end up with a struct that is 2 bytes too long due to struct padding, breaking both reading and writing of bitmaps. Instead of marshalling the data in a struct, let's just provide helpers for reading and writing the appropriate types. Besides being correct on all platforms, the result is more efficient and simpler to read. Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-27 08:24:01 +03:00
commit_idx_pos = read_be32(index->map, &index->map_pos);
xor_offset = read_u8(index->map, &index->map_pos);
flags = read_u8(index->map, &index->map_pos);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
sha1 = nth_packed_object_sha1(index->pack, commit_idx_pos);
bitmap = read_bitmap_1(index);
if (!bitmap)
return -1;
if (xor_offset > MAX_XOR_OFFSET || xor_offset > i)
return error("Corrupted bitmap pack index");
if (xor_offset > 0) {
xor_bitmap = recent_bitmaps[(i - xor_offset) % MAX_XOR_OFFSET];
if (xor_bitmap == NULL)
return error("Invalid XOR offset in bitmap pack index");
}
recent_bitmaps[i % MAX_XOR_OFFSET] = store_bitmap(
index, bitmap, sha1, xor_bitmap, flags);
}
return 0;
}
pack-bitmap.c: make pack_bitmap_filename() static Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-01-15 02:40:53 +03:00
static char *pack_bitmap_filename(struct packed_git *p)
{
use strip_suffix and xstrfmt to replace suffix When we want to convert "foo.pack" to "foo.idx", we do it by duplicating the original string and then munging the bytes in place. Let's use strip_suffix and xstrfmt instead, which has several advantages: 1. It's more clear what the intent is. 2. It does not implicitly rely on the fact that strlen(".idx") <= strlen(".pack") to avoid an overflow. 3. We communicate the assumption that the input file ends with ".pack" (and get a run-time check that this is so). 4. We drop calls to strcpy, which makes auditing the code base easier. Likewise, we can do this to convert ".pack" to ".bitmap", avoiding some manual memory computation. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25 00:07:09 +03:00
size_t len;
pack-bitmap.c: make pack_bitmap_filename() static Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-01-15 02:40:53 +03:00
use strip_suffix and xstrfmt to replace suffix When we want to convert "foo.pack" to "foo.idx", we do it by duplicating the original string and then munging the bytes in place. Let's use strip_suffix and xstrfmt instead, which has several advantages: 1. It's more clear what the intent is. 2. It does not implicitly rely on the fact that strlen(".idx") <= strlen(".pack") to avoid an overflow. 3. We communicate the assumption that the input file ends with ".pack" (and get a run-time check that this is so). 4. We drop calls to strcpy, which makes auditing the code base easier. Likewise, we can do this to convert ".pack" to ".bitmap", avoiding some manual memory computation. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25 00:07:09 +03:00
if (!strip_suffix(p->pack_name, ".pack", &len))
Replace all die("BUG: ...") calls by BUG() ones In d8193743e08 (usage.c: add BUG() function, 2017-05-12), a new macro was introduced to use for reporting bugs instead of die(). It was then subsequently used to convert one single caller in 588a538ae55 (setup_git_env: convert die("BUG") to BUG(), 2017-05-12). The cover letter of the patch series containing this patch (cf 20170513032414.mfrwabt4hovujde2@sigill.intra.peff.net) is not terribly clear why only one call site was converted, or what the plan is for other, similar calls to die() to report bugs. Let's just convert all remaining ones in one fell swoop. This trick was performed by this invocation: sed -i 's/die("BUG: /BUG("/g' $(git grep -l 'die("BUG' \*.c) Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-02 12:38:39 +03:00
BUG("pack_name does not end in .pack");
use strip_suffix and xstrfmt to replace suffix When we want to convert "foo.pack" to "foo.idx", we do it by duplicating the original string and then munging the bytes in place. Let's use strip_suffix and xstrfmt instead, which has several advantages: 1. It's more clear what the intent is. 2. It does not implicitly rely on the fact that strlen(".idx") <= strlen(".pack") to avoid an overflow. 3. We communicate the assumption that the input file ends with ".pack" (and get a run-time check that this is so). 4. We drop calls to strcpy, which makes auditing the code base easier. Likewise, we can do this to convert ".pack" to ".bitmap", avoiding some manual memory computation. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25 00:07:09 +03:00
return xstrfmt("%.*s.bitmap", (int)len, p->pack_name);
pack-bitmap.c: make pack_bitmap_filename() static Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-01-15 02:40:53 +03:00
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git *packfile)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
int fd;
struct stat st;
char *idx_name;
if (open_pack_index(packfile))
return -1;
idx_name = pack_bitmap_filename(packfile);
sha1_file: rename git_open_noatime() to git_open() This function is meant to be used when reading from files in the object store, and the original objective was to avoid smudging atime of loose object files too often, hence its name. Because we'll be extending its role in the next commit to also arrange the file descriptors they return auto-closed in the child processes, rename it to lose "noatime" part that is too specific. Signed-off-by: Lars Schneider <larsxschneider@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-24 21:02:59 +03:00
fd = git_open(idx_name);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
free(idx_name);
if (fd < 0)
return -1;
if (fstat(fd, &st)) {
close(fd);
return -1;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (bitmap_git->pack) {
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
warning("ignoring extra bitmap file: %s", packfile->pack_name);
close(fd);
return -1;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_git->pack = packfile;
bitmap_git->map_size = xsize_t(st.st_size);
bitmap_git->map = xmmap(NULL, bitmap_git->map_size, PROT_READ, MAP_PRIVATE, fd, 0);
bitmap_git->map_pos = 0;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
close(fd);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (load_bitmap_header(bitmap_git) < 0) {
munmap(bitmap_git->map, bitmap_git->map_size);
bitmap_git->map = NULL;
bitmap_git->map_size = 0;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
return -1;
}
return 0;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static int load_pack_bitmap(struct bitmap_index *bitmap_git)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
pack-bitmap: drop "loaded" flag In the early days of the bitmap code, there was a single static bitmap_index struct that was used behind the scenes, and any bitmap-related functions could lazily check bitmap_git.loaded to see if they needed to read the on-disk data. But since 3ae5fa0768 (pack-bitmap: remove bitmap_git global variable, 2018-06-07), the caller is responsible for the lifetime of the bitmap_index struct, and we return it from prepare_bitmap_git() and prepare_bitmap_walk(), both of which load the on-disk data (or return NULL). So outside of these functions, it's not possible to have a bitmap_index for which the loaded flag is not true. Nor is it possible to accidentally pass an already-loaded bitmap_index to the loading function (which is static-local to the file). We can drop this unnecessary and confusing flag. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-01 10:50:57 +03:00
assert(bitmap_git->map);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
bitmap_git->bitmaps = kh_init_oid_map();
bitmap_git->ext_index.positions = kh_init_oid_pos();
pack-revindex: open index if necessary We can't create a pack revindex if we haven't actually looked at the index. Normally we would never get as far as creating a revindex without having already been looking in the pack, so this code never bothered to double-check that pack->index_data had been loaded. But with the new multi-pack-index feature, many code paths might not load the individual pack .idx at all (they'd find objects via the midx and then open the .pack, but not its index). This can't yet be triggered in practice, because a bug in the midx code means we accidentally open up the individual .idx files anyway. But in preparation for fixing that, let's have the revindex code check that everything it needs has been loaded. In most cases this will just be a quick noop. But note that this does introduce a possibility of error (if we have to open the index and it's corrupt), so load_pack_revindex() now returns a result code, and callers need to handle the error. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-05 21:04:24 +03:00
if (load_pack_revindex(bitmap_git->pack))
goto failed;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (!(bitmap_git->commits = read_bitmap_1(bitmap_git)) ||
!(bitmap_git->trees = read_bitmap_1(bitmap_git)) ||
!(bitmap_git->blobs = read_bitmap_1(bitmap_git)) ||
!(bitmap_git->tags = read_bitmap_1(bitmap_git)))
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
goto failed;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (load_bitmap_entries_v1(bitmap_git) < 0)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
goto failed;
return 0;
failed:
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
munmap(bitmap_git->map, bitmap_git->map_size);
bitmap_git->map = NULL;
bitmap_git->map_size = 0;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
return -1;
}
pack-*.c: remove the_repository references Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-10 08:49:08 +03:00
static int open_pack_bitmap(struct repository *r,
struct bitmap_index *bitmap_git)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
struct packed_git *p;
int ret = -1;
pack-bitmap: drop "loaded" flag In the early days of the bitmap code, there was a single static bitmap_index struct that was used behind the scenes, and any bitmap-related functions could lazily check bitmap_git.loaded to see if they needed to read the on-disk data. But since 3ae5fa0768 (pack-bitmap: remove bitmap_git global variable, 2018-06-07), the caller is responsible for the lifetime of the bitmap_index struct, and we return it from prepare_bitmap_git() and prepare_bitmap_walk(), both of which load the on-disk data (or return NULL). So outside of these functions, it's not possible to have a bitmap_index for which the loaded flag is not true. Nor is it possible to accidentally pass an already-loaded bitmap_index to the loading function (which is static-local to the file). We can drop this unnecessary and confusing flag. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-01 10:50:57 +03:00
assert(!bitmap_git->map);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-*.c: remove the_repository references Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-10 08:49:08 +03:00
for (p = get_all_packs(r); p; p = p->next) {
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (open_pack_bitmap_1(bitmap_git, p) == 0)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
ret = 0;
}
return ret;
}
pack-*.c: remove the_repository references Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-10 08:49:08 +03:00
struct bitmap_index *prepare_bitmap_git(struct repository *r)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-*.c: remove the_repository references Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-10 08:49:08 +03:00
if (!open_pack_bitmap(r, bitmap_git) && !load_pack_bitmap(bitmap_git))
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
return bitmap_git;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
free_bitmap_index(bitmap_git);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
return NULL;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
struct include_data {
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_index *bitmap_git;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct bitmap *base;
struct bitmap *seen;
};
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static inline int bitmap_position_extended(struct bitmap_index *bitmap_git,
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
const struct object_id *oid)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
khash: drop broken oid_map typedef Commit 5a8643eff1 (khash: move oid hash table definition, 2019-02-19) added a khash "oid_map" type to match the existing "oid" type, which is a simple set (i.e., just keys, no values). But in setting up the khash_oid_map typedef, it accidentally referred to "kh_oid_t", which is the set type. Nobody noticed the breakage because there are not yet any callers; the type was added just as a match to the existing sha1 types (whose map type confusingly _is_ called khash_sha1, and it has no matching set type). We could easily fix this with s/oid/oid_map/ in the typedef. But let's take this a step further, and just drop the typedef entirely. These typedefs were added by 5a8643eff1 to match the khash_sha1 typedefs. But the actual khash-derived type names are descriptive enough; this is just adding an extra layer of indirection. The khash names do not quite follow our usual style (e.g., they end in "_t"), but since we end up using other khash names (e.g., khiter_t, kh_get_oid()) anyway, just typedef-ing the struct name is not really helping much. And there are already many cases where we use the raw khash type names anyway (e.g., the "set" variant defined just above us does not have such a typedef!). So let's drop this typedef, and the matching oid_pos one (which actually _does_ have a user, but we can easily convert it). We'll leave the khash_sha1 typedef around. The ultimate fate of its callers should be conversion to kh_oid_map_t, so there's no point in going through the noise of changing the names now. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:41:25 +03:00
kh_oid_pos_t *positions = bitmap_git->ext_index.positions;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
khiter_t pos = kh_get_oid_pos(positions, *oid);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (pos < kh_end(positions)) {
int bitmap_pos = kh_value(positions, pos);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
return bitmap_pos + bitmap_git->pack->num_objects;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
return -1;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static inline int bitmap_position_packfile(struct bitmap_index *bitmap_git,
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
const struct object_id *oid)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
off_t offset = find_pack_entry_one(oid->hash, bitmap_git->pack);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (!offset)
return -1;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
return find_revindex_position(bitmap_git->pack, offset);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static int bitmap_position(struct bitmap_index *bitmap_git,
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
const struct object_id *oid)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
int pos = bitmap_position_packfile(bitmap_git, oid);
return (pos >= 0) ? pos : bitmap_position_extended(bitmap_git, oid);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static int ext_index_add_object(struct bitmap_index *bitmap_git,
struct object *object, const char *name)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct eindex *eindex = &bitmap_git->ext_index;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
khiter_t hash_pos;
int hash_ret;
int bitmap_pos;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
hash_pos = kh_put_oid_pos(eindex->positions, object->oid, &hash_ret);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (hash_ret > 0) {
if (eindex->count >= eindex->alloc) {
eindex->alloc = (eindex->alloc + 16) * 3 / 2;
use REALLOC_ARRAY for changing the allocation size of arrays Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-16 22:56:57 +04:00
REALLOC_ARRAY(eindex->objects, eindex->alloc);
REALLOC_ARRAY(eindex->hashes, eindex->alloc);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
bitmap_pos = eindex->count;
eindex->objects[eindex->count] = object;
eindex->hashes[eindex->count] = pack_name_hash(name);
kh_value(eindex->positions, hash_pos) = bitmap_pos;
eindex->count++;
} else {
bitmap_pos = kh_value(eindex->positions, hash_pos);
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
return bitmap_pos + bitmap_git->pack->num_objects;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_show_data {
struct bitmap_index *bitmap_git;
struct bitmap *base;
};
static void show_object(struct object *object, const char *name, void *data_)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_show_data *data = data_;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
int bitmap_pos;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
bitmap_pos = bitmap_position(data->bitmap_git, &object->oid);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
list-objects: pass full pathname to callbacks When we find a blob at "a/b/c", we currently pass this to our show_object_fn callbacks as two components: "a/b/" and "c". Callbacks which want the full value then call path_name(), which concatenates the two. But this is an inefficient interface; the path is a strbuf, and we could simply append "c" to it temporarily, then roll back the length, without creating a new copy. So we could improve this by teaching the callsites of path_name() this trick (and there are only 3). But we can also notice that no callback actually cares about the broken-down representation, and simply pass each callback the full path "a/b/c" as a string. The callback code becomes even simpler, then, as we do not have to worry about freeing an allocated buffer, nor rolling back our modification to the strbuf. This is theoretically less efficient, as some callbacks would not bother to format the final path component. But in practice this is not measurable. Since we use the same strbuf over and over, our work to grow it is amortized, and we really only pay to memcpy a few bytes. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-12 01:28:36 +03:00
if (bitmap_pos < 0)
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_pos = ext_index_add_object(data->bitmap_git, object,
name);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_set(data->base, bitmap_pos);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
static void show_commit(struct commit *commit, void *data)
{
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static int add_to_include_set(struct bitmap_index *bitmap_git,
struct include_data *data,
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
const struct object_id *oid,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
int bitmap_pos)
{
khiter_t hash_pos;
if (data->seen && bitmap_get(data->seen, bitmap_pos))
return 0;
if (bitmap_get(data->base, bitmap_pos))
return 0;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
hash_pos = kh_get_oid_map(bitmap_git->bitmaps, *oid);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (hash_pos < kh_end(bitmap_git->bitmaps)) {
struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, hash_pos);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
bitmap_or_ewah(data->base, lookup_stored_bitmap(st));
return 0;
}
bitmap_set(data->base, bitmap_pos);
return 1;
}
static int should_include(struct commit *commit, void *_data)
{
struct include_data *data = _data;
int bitmap_pos;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
bitmap_pos = bitmap_position(data->bitmap_git, &commit->object.oid);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (bitmap_pos < 0)
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_pos = ext_index_add_object(data->bitmap_git,
(struct object *)commit,
NULL);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
if (!add_to_include_set(data->bitmap_git, data, &commit->object.oid,
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_pos)) {
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct commit_list *parent = commit->parents;
while (parent) {
parent->item->object.flags |= SEEN;
parent = parent->next;
}
return 0;
}
return 1;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static struct bitmap *find_objects(struct bitmap_index *bitmap_git,
struct rev_info *revs,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct object_list *roots,
struct bitmap *seen)
{
struct bitmap *base = NULL;
int needs_walk = 0;
struct object_list *not_mapped = NULL;
/*
* Go through all the roots for the walk. The ones that have bitmaps
* on the bitmap index will be `or`ed together to form an initial
* global reachability analysis.
*
* The ones without bitmaps in the index will be stored in the
* `not_mapped_list` for further processing.
*/
while (roots) {
struct object *object = roots->item;
roots = roots->next;
if (object->type == OBJ_COMMIT) {
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
khiter_t pos = kh_get_oid_map(bitmap_git->bitmaps, object->oid);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (pos < kh_end(bitmap_git->bitmaps)) {
struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct ewah_bitmap *or_with = lookup_stored_bitmap(st);
if (base == NULL)
base = ewah_to_bitmap(or_with);
else
bitmap_or_ewah(base, or_with);
object->flags |= SEEN;
continue;
}
}
object_list_insert(object, &not_mapped);
}
/*
* Best case scenario: We found bitmaps for all the roots,
* so the resulting `or` bitmap has the full reachability analysis
*/
if (not_mapped == NULL)
return base;
roots = not_mapped;
/*
* Let's iterate through all the roots that don't have bitmaps to
* check if we can determine them to be reachable from the existing
* global bitmap.
*
* If we cannot find them in the existing global bitmap, we'll need
* to push them to an actual walk and run it until we can confirm
* they are reachable
*/
while (roots) {
struct object *object = roots->item;
int pos;
roots = roots->next;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
pos = bitmap_position(bitmap_git, &object->oid);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (pos < 0 || base == NULL || !bitmap_get(base, pos)) {
object->flags &= ~UNINTERESTING;
add_pending_object(revs, object, "");
needs_walk = 1;
} else {
object->flags |= SEEN;
}
}
if (needs_walk) {
struct include_data incdata;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_show_data show_data;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (base == NULL)
base = bitmap_new();
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
incdata.bitmap_git = bitmap_git;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
incdata.base = base;
incdata.seen = seen;
revs->include_check = should_include;
revs->include_check_data = &incdata;
if (prepare_revision_walk(revs))
die("revision walk setup failed");
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
show_data.bitmap_git = bitmap_git;
show_data.base = base;
traverse_commit_list(revs, show_commit, show_object,
&show_data);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
return base;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static void show_extended_objects(struct bitmap_index *bitmap_git,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
show_reachable_fn show_reach)
{
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap *objects = bitmap_git->result;
struct eindex *eindex = &bitmap_git->ext_index;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
uint32_t i;
for (i = 0; i < eindex->count; ++i) {
struct object *obj;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (!bitmap_get(objects, bitmap_git->pack->num_objects + i))
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
continue;
obj = eindex->objects[i];
pack-bitmap: convert traverse_bitmap_commit_list to object_id Convert traverse_bitmap_commit_list and the callbacks it takes to use a pointer to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16 01:07:00 +03:00
show_reach(&obj->oid, obj->type, 0, eindex->hashes[i], NULL, 0);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
}
static void show_objects_for_type(
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_index *bitmap_git,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct ewah_bitmap *type_filter,
enum object_type object_type,
show_reachable_fn show_reach)
{
size_t pos = 0, i = 0;
uint32_t offset;
struct ewah_iterator it;
eword_t filter;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap *objects = bitmap_git->result;
if (bitmap_git->reuse_objects == bitmap_git->pack->num_objects)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
return;
ewah_iterator_init(&it, type_filter);
while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
eword_t word = objects->words[i] & filter;
ewah: use less generic macro name The ewah/ewok.h header pollutes the global namespace with "BITS_IN_WORD", without any specific notion that we are talking about the bits in an eword_t. We can give this the more specific name "BITS_IN_EWORD". Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-03 09:39:37 +03:00
for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
pack-bitmap: convert traverse_bitmap_commit_list to object_id Convert traverse_bitmap_commit_list and the callbacks it takes to use a pointer to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16 01:07:00 +03:00
struct object_id oid;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct revindex_entry *entry;
uint32_t hash = 0;
if ((word >> offset) == 0)
break;
offset += ewah_bit_ctz64(word >> offset);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (pos + offset < bitmap_git->reuse_objects)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
continue;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
entry = &bitmap_git->pack->revindex[pos + offset];
nth_packed_object_oid(&oid, bitmap_git->pack, entry->nr);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (bitmap_git->hashes)
hash = get_be32(bitmap_git->hashes + entry->nr);
pack-bitmap: implement optional name_hash cache When we use pack bitmaps rather than walking the object graph, we end up with the list of objects to include in the packfile, but we do not know the path at which any tree or blob objects would be found. In a recently packed repository, this is fine. A fetch would use the paths only as a heuristic in the delta compression phase, and a fully packed repository should not need to do much delta compression. As time passes, though, we may acquire more objects on top of our large bitmapped pack. If clients fetch frequently, then they never even look at the bitmapped history, and all works as usual. However, a client who has not fetched since the last bitmap repack will have "have" tips in the bitmapped history, but "want" newer objects. The bitmaps themselves degrade gracefully in this circumstance. We manually walk the more recent bits of history, and then use bitmaps when we hit them. But we would also like to perform delta compression between the newer objects and the bitmapped objects (both to delta against what we know the user already has, but also between "new" and "old" objects that the user is fetching). The lack of pathnames makes our delta heuristics much less effective. This patch adds an optional cache of the 32-bit name_hash values to the end of the bitmap file. If present, a reader can use it to match bitmapped and non-bitmapped names during delta compression. Here are perf results for p5310: Test origin/master HEAD^ HEAD ------------------------------------------------------------------------------------------------- 5310.2: repack to disk 36.81(37.82+1.43) 47.70(48.74+1.41) +29.6% 47.75(48.70+1.51) +29.7% 5310.3: simulated clone 30.78(29.70+2.14) 1.08(0.97+0.10) -96.5% 1.07(0.94+0.12) -96.5% 5310.4: simulated fetch 3.16(6.10+0.08) 3.54(10.65+0.06) +12.0% 1.70(3.07+0.06) -46.2% 5310.6: partial bitmap 36.76(43.19+1.81) 6.71(11.25+0.76) -81.7% 4.08(6.26+0.46) -88.9% You can see that the time spent on an incremental fetch goes down, as our delta heuristics are able to do their work. And we save time on the partial bitmap clone for the same reason. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:45 +04:00
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
show_reach(&oid, object_type, 0, hash, bitmap_git->pack, entry->offset);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
ewah: use less generic macro name The ewah/ewok.h header pollutes the global namespace with "BITS_IN_WORD", without any specific notion that we are talking about the bits in an eword_t. We can give this the more specific name "BITS_IN_EWORD". Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-03 09:39:37 +03:00
pos += BITS_IN_EWORD;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
i++;
}
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static int in_bitmapped_pack(struct bitmap_index *bitmap_git,
struct object_list *roots)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
while (roots) {
struct object *object = roots->item;
roots = roots->next;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (find_pack_entry_one(object->oid.hash, bitmap_git->pack) > 0)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
return 1;
}
return 0;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
unsigned int i;
struct object_list *wants = NULL;
struct object_list *haves = NULL;
struct bitmap *wants_bitmap = NULL;
struct bitmap *haves_bitmap = NULL;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
/* try to open a bitmapped pack, but don't parse it yet
* because we may not need to use it */
pack-*.c: remove the_repository references Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-10 08:49:08 +03:00
if (open_pack_bitmap(revs->repo, bitmap_git) < 0)
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
goto cleanup;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap[-write]: use `object_array_clear()`, don't leak Instead of setting the fields of rev->pending to 0/NULL, thereby leaking memory, call `object_array_clear(&rev->pending)`. In pack-bitmap.c, we make copies of those fields as `pending_nr` and `pending_e`. We never update the aliases and the original fields never change, so the aliases are not really needed and just make it harder than necessary to understand the code. While we're here, remove the aliases to make the code easier to follow. Signed-off-by: Martin Ågren <martin.agren@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-23 02:34:54 +03:00
for (i = 0; i < revs->pending.nr; ++i) {
struct object *object = revs->pending.objects[i].item;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (object->type == OBJ_NONE)
object: convert parse_object* to take struct object_id Make parse_object, parse_object_or_die, and parse_object_buffer take a pointer to struct object_id. Remove the temporary variables inserted earlier, since they are no longer necessary. Transform all of the callers using the following semantic patch: @@ expression E1; @@ - parse_object(E1.hash) + parse_object(&E1) @@ expression E1; @@ - parse_object(E1->hash) + parse_object(E1) @@ expression E1, E2; @@ - parse_object_or_die(E1.hash, E2) + parse_object_or_die(&E1, E2) @@ expression E1, E2; @@ - parse_object_or_die(E1->hash, E2) + parse_object_or_die(E1, E2) @@ expression E1, E2, E3, E4, E5; @@ - parse_object_buffer(E1.hash, E2, E3, E4, E5) + parse_object_buffer(&E1, E2, E3, E4, E5) @@ expression E1, E2, E3, E4, E5; @@ - parse_object_buffer(E1->hash, E2, E3, E4, E5) + parse_object_buffer(E1, E2, E3, E4, E5) Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-07 01:10:38 +03:00
parse_object_or_die(&object->oid, NULL);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
while (object->type == OBJ_TAG) {
struct tag *tag = (struct tag *) object;
if (object->flags & UNINTERESTING)
object_list_insert(object, &haves);
else
object_list_insert(object, &wants);
if (!tag->tagged)
die("bad tag");
object: convert parse_object* to take struct object_id Make parse_object, parse_object_or_die, and parse_object_buffer take a pointer to struct object_id. Remove the temporary variables inserted earlier, since they are no longer necessary. Transform all of the callers using the following semantic patch: @@ expression E1; @@ - parse_object(E1.hash) + parse_object(&E1) @@ expression E1; @@ - parse_object(E1->hash) + parse_object(E1) @@ expression E1, E2; @@ - parse_object_or_die(E1.hash, E2) + parse_object_or_die(&E1, E2) @@ expression E1, E2; @@ - parse_object_or_die(E1->hash, E2) + parse_object_or_die(E1, E2) @@ expression E1, E2, E3, E4, E5; @@ - parse_object_buffer(E1.hash, E2, E3, E4, E5) + parse_object_buffer(&E1, E2, E3, E4, E5) @@ expression E1, E2, E3, E4, E5; @@ - parse_object_buffer(E1->hash, E2, E3, E4, E5) + parse_object_buffer(E1, E2, E3, E4, E5) Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-07 01:10:38 +03:00
object = parse_object_or_die(&tag->tagged->oid, NULL);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
if (object->flags & UNINTERESTING)
object_list_insert(object, &haves);
else
object_list_insert(object, &wants);
}
/*
* if we have a HAVES list, but none of those haves is contained
* in the packfile that has a bitmap, we don't have anything to
* optimize here
*/
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (haves && !in_bitmapped_pack(bitmap_git, haves))
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
goto cleanup;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
/* if we don't want anything, we're done here */
if (!wants)
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
goto cleanup;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
/*
* now we're going to use bitmaps, so load the actual bitmap entries
* from disk. this is the point of no return; after this the rev_list
* becomes invalidated and we must perform the revwalk through bitmaps
*/
pack-bitmap: drop "loaded" flag In the early days of the bitmap code, there was a single static bitmap_index struct that was used behind the scenes, and any bitmap-related functions could lazily check bitmap_git.loaded to see if they needed to read the on-disk data. But since 3ae5fa0768 (pack-bitmap: remove bitmap_git global variable, 2018-06-07), the caller is responsible for the lifetime of the bitmap_index struct, and we return it from prepare_bitmap_git() and prepare_bitmap_walk(), both of which load the on-disk data (or return NULL). So outside of these functions, it's not possible to have a bitmap_index for which the loaded flag is not true. Nor is it possible to accidentally pass an already-loaded bitmap_index to the loading function (which is static-local to the file). We can drop this unnecessary and confusing flag. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-01 10:50:57 +03:00
if (load_pack_bitmap(bitmap_git) < 0)
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
goto cleanup;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap[-write]: use `object_array_clear()`, don't leak Instead of setting the fields of rev->pending to 0/NULL, thereby leaking memory, call `object_array_clear(&rev->pending)`. In pack-bitmap.c, we make copies of those fields as `pending_nr` and `pending_e`. We never update the aliases and the original fields never change, so the aliases are not really needed and just make it harder than necessary to understand the code. While we're here, remove the aliases to make the code easier to follow. Signed-off-by: Martin Ågren <martin.agren@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-23 02:34:54 +03:00
object_array_clear(&revs->pending);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (haves) {
add `ignore_missing_links` mode to revwalk When pack-objects is computing the reachability bitmap to serve a fetch request, it can erroneously die() if some of the UNINTERESTING objects are not present. Upload-pack throws away HAVE lines from the client for objects we do not have, but we may have a tip object without all of its ancestors (e.g., if the tip is no longer reachable and was new enough to survive a `git prune`, but some of its reachable objects did get pruned). In the non-bitmap case, we do a revision walk with the HAVE objects marked as UNINTERESTING. The revision walker explicitly ignores errors in accessing UNINTERESTING commits to handle this case (and we do not bother looking at UNINTERESTING trees or blobs at all). When we have bitmaps, however, the process is quite different. The bitmap index for a pack-objects run is calculated in two separate steps: First, we perform an extensive walk from all the HAVEs to find the full set of objects reachable from them. This walk is usually optimized away because we are expected to hit an object with a bitmap during the traversal, which allows us to terminate early. Secondly, we perform an extensive walk from all the WANTs, which usually also terminates early because we hit a commit with an existing bitmap. Once we have the resulting bitmaps from the two walks, we AND-NOT them together to obtain the resulting set of objects we need to pack. When we are walking the HAVE objects, the revision walker does not know that we are walking it only to mark the results as uninteresting. We strip out the UNINTERESTING flag, because those objects _are_ interesting to us during the first walk. We want to keep going to get a complete set of reachable objects if we can. We need some way to tell the revision walker that it's OK to silently truncate the HAVE walk, just like it does for the UNINTERESTING case. This patch introduces a new `ignore_missing_links` flag to the `rev_info` struct, which we set only for the HAVE walk. It also adds tests to cover UNINTERESTING objects missing from several positions: a missing blob, a missing tree, and a missing parent commit. The missing blob already worked (as we do not care about its contents at all), but the other two cases caused us to die(). Note that there are a few cases we do not need to test: 1. We do not need to test a missing tree, with the blob still present. Without the tree that refers to it, we would not know that the blob is relevant to our walk. 2. We do not need to test a tip commit that is missing. Upload-pack omits these for us (and in fact, we complain even in the non-bitmap case if it fails to do so). Reported-by: Siddharth Agarwal <sid0@fb.com> Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-28 14:00:43 +04:00
revs->ignore_missing_links = 1;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
haves_bitmap = find_objects(bitmap_git, revs, haves, NULL);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
reset_revision_walk();
add `ignore_missing_links` mode to revwalk When pack-objects is computing the reachability bitmap to serve a fetch request, it can erroneously die() if some of the UNINTERESTING objects are not present. Upload-pack throws away HAVE lines from the client for objects we do not have, but we may have a tip object without all of its ancestors (e.g., if the tip is no longer reachable and was new enough to survive a `git prune`, but some of its reachable objects did get pruned). In the non-bitmap case, we do a revision walk with the HAVE objects marked as UNINTERESTING. The revision walker explicitly ignores errors in accessing UNINTERESTING commits to handle this case (and we do not bother looking at UNINTERESTING trees or blobs at all). When we have bitmaps, however, the process is quite different. The bitmap index for a pack-objects run is calculated in two separate steps: First, we perform an extensive walk from all the HAVEs to find the full set of objects reachable from them. This walk is usually optimized away because we are expected to hit an object with a bitmap during the traversal, which allows us to terminate early. Secondly, we perform an extensive walk from all the WANTs, which usually also terminates early because we hit a commit with an existing bitmap. Once we have the resulting bitmaps from the two walks, we AND-NOT them together to obtain the resulting set of objects we need to pack. When we are walking the HAVE objects, the revision walker does not know that we are walking it only to mark the results as uninteresting. We strip out the UNINTERESTING flag, because those objects _are_ interesting to us during the first walk. We want to keep going to get a complete set of reachable objects if we can. We need some way to tell the revision walker that it's OK to silently truncate the HAVE walk, just like it does for the UNINTERESTING case. This patch introduces a new `ignore_missing_links` flag to the `rev_info` struct, which we set only for the HAVE walk. It also adds tests to cover UNINTERESTING objects missing from several positions: a missing blob, a missing tree, and a missing parent commit. The missing blob already worked (as we do not care about its contents at all), but the other two cases caused us to die(). Note that there are a few cases we do not need to test: 1. We do not need to test a missing tree, with the blob still present. Without the tree that refers to it, we would not know that the blob is relevant to our walk. 2. We do not need to test a tip commit that is missing. Upload-pack omits these for us (and in fact, we complain even in the non-bitmap case if it fails to do so). Reported-by: Siddharth Agarwal <sid0@fb.com> Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-28 14:00:43 +04:00
revs->ignore_missing_links = 0;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (haves_bitmap == NULL)
Replace all die("BUG: ...") calls by BUG() ones In d8193743e08 (usage.c: add BUG() function, 2017-05-12), a new macro was introduced to use for reporting bugs instead of die(). It was then subsequently used to convert one single caller in 588a538ae55 (setup_git_env: convert die("BUG") to BUG(), 2017-05-12). The cover letter of the patch series containing this patch (cf 20170513032414.mfrwabt4hovujde2@sigill.intra.peff.net) is not terribly clear why only one call site was converted, or what the plan is for other, similar calls to die() to report bugs. Let's just convert all remaining ones in one fell swoop. This trick was performed by this invocation: sed -i 's/die("BUG: /BUG("/g' $(git grep -l 'die("BUG' \*.c) Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-02 12:38:39 +03:00
BUG("failed to perform bitmap walk");
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
wants_bitmap = find_objects(bitmap_git, revs, wants, haves_bitmap);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (!wants_bitmap)
Replace all die("BUG: ...") calls by BUG() ones In d8193743e08 (usage.c: add BUG() function, 2017-05-12), a new macro was introduced to use for reporting bugs instead of die(). It was then subsequently used to convert one single caller in 588a538ae55 (setup_git_env: convert die("BUG") to BUG(), 2017-05-12). The cover letter of the patch series containing this patch (cf 20170513032414.mfrwabt4hovujde2@sigill.intra.peff.net) is not terribly clear why only one call site was converted, or what the plan is for other, similar calls to die() to report bugs. Let's just convert all remaining ones in one fell swoop. This trick was performed by this invocation: sed -i 's/die("BUG: /BUG("/g' $(git grep -l 'die("BUG' \*.c) Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-02 12:38:39 +03:00
BUG("failed to perform bitmap walk");
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (haves_bitmap)
bitmap_and_not(wants_bitmap, haves_bitmap);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_git->result = wants_bitmap;
pack-bitmap: save "have" bitmap from walk When we do a bitmap walk, we save the result, which represents (WANTs & ~HAVEs); i.e., every object we care about visiting in our walk. However, we throw away the haves bitmap, which can sometimes be useful, too. Save it and provide an access function so code which has performed a walk can query it. A few notes on the accessor interface: - the bitmap code calls these "haves" because it grew out of the want/have negotiation for fetches. But really, these are simply the objects that would be flagged UNINTERESTING in a regular traversal. Let's use that more universal nomenclature for the external module interface. We may want to change the internal naming inside the bitmap code, but that's outside the scope of this patch. - it still uses a bare "sha1" rather than "oid". That's true of all of the bitmap code. And in this particular instance, our caller in pack-objects is dealing with the bare sha1 that comes from a packed REF_DELTA (we're pointing directly to the mmap'd pack on disk). That's something we'll have to deal with as we transition to a new hash, but we can wait and see how the caller ends up being fixed and adjust this interface accordingly. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 22:07:01 +03:00
bitmap_git->haves = haves_bitmap;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
return bitmap_git;
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
cleanup:
free_bitmap_index(bitmap_git);
return NULL;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
struct packed_git **packfile,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
uint32_t *entries,
off_t *up_to)
{
/*
* Reuse the packfile content if we need more than
* 90% of its objects
*/
static const double REUSE_PERCENT = 0.9;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap *result = bitmap_git->result;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
uint32_t reuse_threshold;
uint32_t i, reuse_objects = 0;
assert(result);
for (i = 0; i < result->word_alloc; ++i) {
if (result->words[i] != (eword_t)~0) {
reuse_objects += ewah_bit_ctz64(~result->words[i]);
break;
}
ewah: use less generic macro name The ewah/ewok.h header pollutes the global namespace with "BITS_IN_WORD", without any specific notion that we are talking about the bits in an eword_t. We can give this the more specific name "BITS_IN_EWORD". Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-03 09:39:37 +03:00
reuse_objects += BITS_IN_EWORD;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
#ifdef GIT_BITMAP_DEBUG
{
const unsigned char *sha1;
struct revindex_entry *entry;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
entry = &bitmap_git->reverse_index->revindex[reuse_objects];
sha1 = nth_packed_object_sha1(bitmap_git->pack, entry->nr);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
fprintf(stderr, "Failed to reuse at %d (%016llx)\n",
reuse_objects, result->words[i]);
pack-bitmap: replace sha1_to_hex Replace the uses of sha1_to_hex in the pack bitmap code with hash_to_hex to allow the use of SHA-256 as well. Rename a few variables since they are no longer limited to SHA-1. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:56 +03:00
fprintf(stderr, " %s\n", hash_to_hex(sha1));
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
#endif
if (!reuse_objects)
return -1;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (reuse_objects >= bitmap_git->pack->num_objects) {
bitmap_git->reuse_objects = *entries = bitmap_git->pack->num_objects;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
*up_to = -1; /* reuse the full pack */
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
*packfile = bitmap_git->pack;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
return 0;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
reuse_threshold = bitmap_popcount(bitmap_git->result) * REUSE_PERCENT;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (reuse_objects < reuse_threshold)
return -1;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_git->reuse_objects = *entries = reuse_objects;
*up_to = bitmap_git->pack->revindex[reuse_objects].offset;
*packfile = bitmap_git->pack;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
return 0;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
void traverse_bitmap_commit_list(struct bitmap_index *bitmap_git,
show_reachable_fn show_reachable)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
assert(bitmap_git->result);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
show_objects_for_type(bitmap_git, bitmap_git->commits,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
OBJ_COMMIT, show_reachable);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
show_objects_for_type(bitmap_git, bitmap_git->trees,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
OBJ_TREE, show_reachable);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
show_objects_for_type(bitmap_git, bitmap_git->blobs,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
OBJ_BLOB, show_reachable);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
show_objects_for_type(bitmap_git, bitmap_git->tags,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
OBJ_TAG, show_reachable);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
show_extended_objects(bitmap_git, show_reachable);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
static uint32_t count_object_type(struct bitmap_index *bitmap_git,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
enum object_type type)
{
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap *objects = bitmap_git->result;
struct eindex *eindex = &bitmap_git->ext_index;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
uint32_t i = 0, count = 0;
struct ewah_iterator it;
eword_t filter;
switch (type) {
case OBJ_COMMIT:
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
ewah_iterator_init(&it, bitmap_git->commits);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
break;
case OBJ_TREE:
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
ewah_iterator_init(&it, bitmap_git->trees);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
break;
case OBJ_BLOB:
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
ewah_iterator_init(&it, bitmap_git->blobs);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
break;
case OBJ_TAG:
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
ewah_iterator_init(&it, bitmap_git->tags);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
break;
default:
return 0;
}
while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
eword_t word = objects->words[i++] & filter;
count += ewah_bit_popcount64(word);
}
for (i = 0; i < eindex->count; ++i) {
if (eindex->objects[i]->type == type &&
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_get(objects, bitmap_git->pack->num_objects + i))
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
count++;
}
return count;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
void count_bitmap_commit_list(struct bitmap_index *bitmap_git,
uint32_t *commits, uint32_t *trees,
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
uint32_t *blobs, uint32_t *tags)
{
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
assert(bitmap_git->result);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (commits)
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
*commits = count_object_type(bitmap_git, OBJ_COMMIT);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (trees)
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
*trees = count_object_type(bitmap_git, OBJ_TREE);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (blobs)
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
*blobs = count_object_type(bitmap_git, OBJ_BLOB);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (tags)
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
*tags = count_object_type(bitmap_git, OBJ_TAG);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
struct bitmap_test_data {
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_index *bitmap_git;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct bitmap *base;
struct progress *prg;
size_t seen;
};
list-objects: pass full pathname to callbacks When we find a blob at "a/b/c", we currently pass this to our show_object_fn callbacks as two components: "a/b/" and "c". Callbacks which want the full value then call path_name(), which concatenates the two. But this is an inefficient interface; the path is a strbuf, and we could simply append "c" to it temporarily, then roll back the length, without creating a new copy. So we could improve this by teaching the callsites of path_name() this trick (and there are only 3). But we can also notice that no callback actually cares about the broken-down representation, and simply pass each callback the full path "a/b/c" as a string. The callback code becomes even simpler, then, as we do not have to worry about freeing an allocated buffer, nor rolling back our modification to the strbuf. This is theoretically less efficient, as some callbacks would not bother to format the final path component. But in practice this is not measurable. Since we use the same strbuf over and over, our work to grow it is amortized, and we really only pay to memcpy a few bytes. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-12 01:28:36 +03:00
static void test_show_object(struct object *object, const char *name,
void *data)
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
{
struct bitmap_test_data *tdata = data;
int bitmap_pos;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
bitmap_pos = bitmap_position(tdata->bitmap_git, &object->oid);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (bitmap_pos < 0)
Convert struct object to object_id struct object is one of the major data structures dealing with object IDs. Convert it to use struct object_id instead of an unsigned char array. Convert get_object_hash to refer to the new member as well. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Jeff King <peff@peff.net>
2015-11-10 05:22:28 +03:00
die("Object not in bitmap: %s\n", oid_to_hex(&object->oid));
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
bitmap_set(tdata->base, bitmap_pos);
display_progress(tdata->prg, ++tdata->seen);
}
static void test_show_commit(struct commit *commit, void *data)
{
struct bitmap_test_data *tdata = data;
int bitmap_pos;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_pos = bitmap_position(tdata->bitmap_git,
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
&commit->object.oid);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
if (bitmap_pos < 0)
Convert struct object to object_id struct object is one of the major data structures dealing with object IDs. Convert it to use struct object_id instead of an unsigned char array. Convert get_object_hash to refer to the new member as well. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Jeff King <peff@peff.net>
2015-11-10 05:22:28 +03:00
die("Object not in bitmap: %s\n", oid_to_hex(&commit->object.oid));
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
bitmap_set(tdata->base, bitmap_pos);
display_progress(tdata->prg, ++tdata->seen);
}
void test_bitmap_walk(struct rev_info *revs)
{
struct object *root;
struct bitmap *result = NULL;
khiter_t pos;
size_t result_popcnt;
struct bitmap_test_data tdata;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
struct bitmap_index *bitmap_git;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-*.c: remove the_repository references Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-10 08:49:08 +03:00
if (!(bitmap_git = prepare_bitmap_git(revs->repo)))
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
die("failed to load bitmap indexes");
if (revs->pending.nr != 1)
die("you must specify exactly one commit to test");
fprintf(stderr, "Bitmap v%d test (%d entries loaded)\n",
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
bitmap_git->version, bitmap_git->entry_count);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
root = revs->pending.objects[0].item;
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
pos = kh_get_oid_map(bitmap_git->bitmaps, root->oid);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
if (pos < kh_end(bitmap_git->bitmaps)) {
struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
struct ewah_bitmap *bm = lookup_stored_bitmap(st);
fprintf(stderr, "Found bitmap for %s. %d bits / %08x checksum\n",
Convert struct object to object_id struct object is one of the major data structures dealing with object IDs. Convert it to use struct object_id instead of an unsigned char array. Convert get_object_hash to refer to the new member as well. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Jeff King <peff@peff.net>
2015-11-10 05:22:28 +03:00
oid_to_hex(&root->oid), (int)bm->bit_size, ewah_checksum(bm));
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
result = ewah_to_bitmap(bm);
}
if (result == NULL)
Convert struct object to object_id struct object is one of the major data structures dealing with object IDs. Convert it to use struct object_id instead of an unsigned char array. Convert get_object_hash to refer to the new member as well. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Jeff King <peff@peff.net>
2015-11-10 05:22:28 +03:00
die("Commit %s doesn't have an indexed bitmap", oid_to_hex(&root->oid));
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
revs->tag_objects = 1;
revs->tree_objects = 1;
revs->blob_objects = 1;
result_popcnt = bitmap_popcount(result);
if (prepare_revision_walk(revs))
die("revision walk setup failed");
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
tdata.bitmap_git = bitmap_git;
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
tdata.base = bitmap_new();
tdata.prg = start_progress("Verifying bitmap entries", result_popcnt);
tdata.seen = 0;
traverse_commit_list(revs, &test_show_commit, &test_show_object, &tdata);
stop_progress(&tdata.prg);
if (bitmap_equals(result, tdata.base))
fprintf(stderr, "OK!\n");
else
fprintf(stderr, "Mismatch!\n");
pack-bitmap.c: fix a memleak Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-31 04:22:10 +03:00
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
free_bitmap_index(bitmap_git);
pack-bitmap: add support for bitmap indexes A bitmap index is a `.bitmap` file that can be found inside `$GIT_DIR/objects/pack/`, next to its corresponding packfile, and contains precalculated reachability information for selected commits. The full specification of the format for these bitmap indexes can be found in `Documentation/technical/bitmap-format.txt`. For a given commit SHA1, if it happens to be available in the bitmap index, its bitmap will represent every single object that is reachable from the commit itself. The nth bit in the bitmap is the nth object in the packfile; if it's set to 1, the object is reachable. By using the bitmaps available in the index, this commit implements several new functions: - `prepare_bitmap_git` - `prepare_bitmap_walk` - `traverse_bitmap_commit_list` - `reuse_partial_packfile_from_bitmap` The `prepare_bitmap_walk` function tries to build a bitmap of all the objects that can be reached from the commit roots of a given `rev_info` struct by using the following algorithm: - If all the interesting commits for a revision walk are available in the index, the resulting reachability bitmap is the bitwise OR of all the individual bitmaps. - When the full set of WANTs is not available in the index, we perform a partial revision walk using the commits that don't have bitmaps as roots, and limiting the revision walk as soon as we reach a commit that has a corresponding bitmap. The earlier OR'ed bitmap with all the indexed commits can now be completed as this walk progresses, so the end result is the full reachability list. - For revision walks with a HAVEs set (a set of commits that are deemed uninteresting), first we perform the same method as for the WANTs, but using our HAVEs as roots, in order to obtain a full reachability bitmap of all the uninteresting commits. This bitmap then can be used to: a) limit the subsequent walk when building the WANTs bitmap b) finding the final set of interesting commits by performing an AND-NOT of the WANTs and the HAVEs. If `prepare_bitmap_walk` runs successfully, the resulting bitmap is stored and the equivalent of a `traverse_commit_list` call can be performed by using `traverse_bitmap_commit_list`; the bitmap version of this call yields the objects straight from the packfile index (without having to look them up or parse them) and hence is several orders of magnitude faster. As an extra optimization, when `prepare_bitmap_walk` succeeds, the `reuse_partial_packfile_from_bitmap` call can be attempted: it will find the amount of objects at the beginning of the on-disk packfile that can be reused as-is, and return an offset into the packfile. The source packfile can then be loaded and the bytes up to `offset` can be written directly to the result without having to consider the entires inside the packfile individually. If the `prepare_bitmap_walk` call fails (e.g. because no bitmap files are available), the `rev_info` struct is left untouched, and can be used to perform a manual rev-walk using `traverse_commit_list`. Hence, this new set of functions are a generic API that allows to perform the equivalent of git rev-list --objects [roots...] [^uninteresting...] for any set of commits, even if they don't have specific bitmaps generated for them. In further patches, we'll use this bitmap traversal optimization to speed up the `pack-objects` and `rev-list` commands. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:01 +04:00
}
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
static int rebuild_bitmap(uint32_t *reposition,
struct ewah_bitmap *source,
struct bitmap *dest)
{
uint32_t pos = 0;
struct ewah_iterator it;
eword_t word;
ewah_iterator_init(&it, source);
while (ewah_iterator_next(&word, &it)) {
uint32_t offset, bit_pos;
ewah: use less generic macro name The ewah/ewok.h header pollutes the global namespace with "BITS_IN_WORD", without any specific notion that we are talking about the bits in an eword_t. We can give this the more specific name "BITS_IN_EWORD". Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-03 09:39:37 +03:00
for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
if ((word >> offset) == 0)
break;
offset += ewah_bit_ctz64(word >> offset);
bit_pos = reposition[pos + offset];
if (bit_pos > 0)
bitmap_set(dest, bit_pos - 1);
else /* can't reuse, we don't have the object */
return -1;
}
ewah: use less generic macro name The ewah/ewok.h header pollutes the global namespace with "BITS_IN_WORD", without any specific notion that we are talking about the bits in an eword_t. We can give this the more specific name "BITS_IN_EWORD". Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-03 09:39:37 +03:00
pos += BITS_IN_EWORD;
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
}
return 0;
}
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
int rebuild_existing_bitmaps(struct bitmap_index *bitmap_git,
struct packing_data *mapping,
pack-bitmap: convert khash_sha1 maps into kh_oid_map All of the users of our khash_sha1 maps actually have a "struct object_id". Let's use the more descriptive type. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:41:35 +03:00
kh_oid_map_t *reused_bitmaps,
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
int show_progress)
{
uint32_t i, num_objects;
uint32_t *reposition;
struct bitmap *rebuild;
struct stored_bitmap *stored;
struct progress *progress = NULL;
khiter_t hash_pos;
int hash_ret;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
num_objects = bitmap_git->pack->num_objects;
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
reposition = xcalloc(num_objects, sizeof(uint32_t));
for (i = 0; i < num_objects; ++i) {
pack-objects: convert packlist_find() to use object_id We take a raw hash pointer, but most of our callers have a "struct object_id" already. Let's switch to taking the full struct, which will let us continue removing uses of raw sha1 buffers. There are two callers that do need special attention: - in rebuild_existing_bitmaps(), we need to switch to nth_packed_object_oid(). This incurs an extra hash copy over pointing straight to the mmap'd sha1, but it shouldn't be measurable compared to the rest of the operation. - in can_reuse_delta() we already spent the effort to copy the sha1 into a "struct object_id", but now we just have to do so a little earlier in the function (we can't easily convert that function's callers because they may be pointing at mmap'd REF_DELTA blocks). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:41:03 +03:00
struct object_id oid;
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
struct revindex_entry *entry;
struct object_entry *oe;
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
entry = &bitmap_git->pack->revindex[i];
pack-objects: convert packlist_find() to use object_id We take a raw hash pointer, but most of our callers have a "struct object_id" already. Let's switch to taking the full struct, which will let us continue removing uses of raw sha1 buffers. There are two callers that do need special attention: - in rebuild_existing_bitmaps(), we need to switch to nth_packed_object_oid(). This incurs an extra hash copy over pointing straight to the mmap'd sha1, but it shouldn't be measurable compared to the rest of the operation. - in can_reuse_delta() we already spent the effort to copy the sha1 into a "struct object_id", but now we just have to do so a little earlier in the function (we can't easily convert that function's callers because they may be pointing at mmap'd REF_DELTA blocks). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:41:03 +03:00
nth_packed_object_oid(&oid, bitmap_git->pack, entry->nr);
oe = packlist_find(mapping, &oid, NULL);
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
if (oe)
pack-objects: move in_pack_pos out of struct object_entry This field is only need for pack-bitmap, which is an optional feature. Move it to a separate array that is only allocated when pack-bitmap is used (like objects[], it is not freed, since we need it until the end of the process) Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-14 18:35:04 +03:00
reposition[i] = oe_in_pack_pos(mapping, oe) + 1;
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
}
rebuild = bitmap_new();
i = 0;
if (show_progress)
progress = start_progress("Reusing bitmaps", 0);
pack-bitmap: remove bitmap_git global variable Remove the bitmap_git global variable. Instead, generate on demand an instance of struct bitmap_index for code that needs to access it. This allows us significant control over the lifetime of instances of struct bitmap_index. In particular, packs can now be closed without worrying if an unnecessarily long-lived "pack" field in struct bitmap_index still points to it. The bitmap API is also clearer in that we need to first obtain a struct bitmap_index, then we use it. This patch raises two potential issues: (1) memory for the struct bitmap_index is allocated without being freed, and (2) prepare_bitmap_git() and prepare_bitmap_walk() can reuse a previously loaded bitmap. For (1), this will be dealt with in a subsequent patch in this patch set that also deals with freeing the contents of the struct bitmap_index (which were not freed previously, because they have global scope). For (2), current bitmap users only load the bitmap once at most (note that pack-objects can use bitmaps or write bitmaps, but not both at the same time), so support for reuse has no effect - and future users can pass around the struct bitmap_index * obtained if they need to do 2 or more things with the same bitmap. Helped-by: Stefan Beller <sbeller@google.com> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:13 +03:00
kh_foreach_value(bitmap_git->bitmaps, stored, {
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
if (stored->flags & BITMAP_FLAG_REUSE) {
if (!rebuild_bitmap(reposition,
lookup_stored_bitmap(stored),
rebuild)) {
pack-bitmap: convert khash_sha1 maps into kh_oid_map All of the users of our khash_sha1 maps actually have a "struct object_id". Let's use the more descriptive type. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:41:35 +03:00
hash_pos = kh_put_oid_map(reused_bitmaps,
stored->oid,
&hash_ret);
pack-objects: implement bitmap writing This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-21 18:00:16 +04:00
kh_value(reused_bitmaps, hash_pos) =
bitmap_to_ewah(rebuild);
}
bitmap_reset(rebuild);
display_progress(progress, ++i);
}
});
stop_progress(&progress);
free(reposition);
bitmap_free(rebuild);
return 0;
}
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
void free_bitmap_index(struct bitmap_index *b)
{
if (!b)
return;
if (b->map)
munmap(b->map, b->map_size);
ewah_pool_free(b->commits);
ewah_pool_free(b->trees);
ewah_pool_free(b->blobs);
ewah_pool_free(b->tags);
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
kh_destroy_oid_map(b->bitmaps);
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
free(b->ext_index.objects);
free(b->ext_index.hashes);
bitmap_free(b->result);
pack-bitmap: save "have" bitmap from walk When we do a bitmap walk, we save the result, which represents (WANTs & ~HAVEs); i.e., every object we care about visiting in our walk. However, we throw away the haves bitmap, which can sometimes be useful, too. Save it and provide an access function so code which has performed a walk can query it. A few notes on the accessor interface: - the bitmap code calls these "haves" because it grew out of the want/have negotiation for fetches. But really, these are simply the objects that would be flagged UNINTERESTING in a regular traversal. Let's use that more universal nomenclature for the external module interface. We may want to change the internal naming inside the bitmap code, but that's outside the scope of this patch. - it still uses a bare "sha1" rather than "oid". That's true of all of the bitmap code. And in this particular instance, our caller in pack-objects is dealing with the bare sha1 that comes from a packed REF_DELTA (we're pointing directly to the mmap'd pack on disk). That's something we'll have to deal with as we transition to a new hash, but we can wait and see how the caller ends up being fixed and adjust this interface accordingly. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 22:07:01 +03:00
bitmap_free(b->haves);
pack-bitmap: add free function Add a function to free struct bitmap_index instances, and use it where needed (except when rebuild_existing_bitmaps() is used, since it creates references to the bitmaps within the struct bitmap_index passed to it). Note that the hashes field in struct bitmap_index is not freed because it points to another field within the same struct. The documentation for that field has been updated to clarify that. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-07 22:04:14 +03:00
free(b);
}
pack-bitmap: save "have" bitmap from walk When we do a bitmap walk, we save the result, which represents (WANTs & ~HAVEs); i.e., every object we care about visiting in our walk. However, we throw away the haves bitmap, which can sometimes be useful, too. Save it and provide an access function so code which has performed a walk can query it. A few notes on the accessor interface: - the bitmap code calls these "haves" because it grew out of the want/have negotiation for fetches. But really, these are simply the objects that would be flagged UNINTERESTING in a regular traversal. Let's use that more universal nomenclature for the external module interface. We may want to change the internal naming inside the bitmap code, but that's outside the scope of this patch. - it still uses a bare "sha1" rather than "oid". That's true of all of the bitmap code. And in this particular instance, our caller in pack-objects is dealing with the bare sha1 that comes from a packed REF_DELTA (we're pointing directly to the mmap'd pack on disk). That's something we'll have to deal with as we transition to a new hash, but we can wait and see how the caller ends up being fixed and adjust this interface accordingly. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 22:07:01 +03:00
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
int bitmap_has_oid_in_uninteresting(struct bitmap_index *bitmap_git,
const struct object_id *oid)
pack-bitmap: save "have" bitmap from walk When we do a bitmap walk, we save the result, which represents (WANTs & ~HAVEs); i.e., every object we care about visiting in our walk. However, we throw away the haves bitmap, which can sometimes be useful, too. Save it and provide an access function so code which has performed a walk can query it. A few notes on the accessor interface: - the bitmap code calls these "haves" because it grew out of the want/have negotiation for fetches. But really, these are simply the objects that would be flagged UNINTERESTING in a regular traversal. Let's use that more universal nomenclature for the external module interface. We may want to change the internal naming inside the bitmap code, but that's outside the scope of this patch. - it still uses a bare "sha1" rather than "oid". That's true of all of the bitmap code. And in this particular instance, our caller in pack-objects is dealing with the bare sha1 that comes from a packed REF_DELTA (we're pointing directly to the mmap'd pack on disk). That's something we'll have to deal with as we transition to a new hash, but we can wait and see how the caller ends up being fixed and adjust this interface accordingly. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 22:07:01 +03:00
{
int pos;
if (!bitmap_git)
return 0; /* no bitmap loaded */
if (!bitmap_git->haves)
return 0; /* walk had no "haves" */
pack-bitmap: switch hash tables to use struct object_id Instead of storing unsigned char pointers in the hash tables, switch to storing instances of struct object_id. Update several internal functions and one external function to take pointers to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-19 03:04:58 +03:00
pos = bitmap_position_packfile(bitmap_git, oid);
pack-bitmap: save "have" bitmap from walk When we do a bitmap walk, we save the result, which represents (WANTs & ~HAVEs); i.e., every object we care about visiting in our walk. However, we throw away the haves bitmap, which can sometimes be useful, too. Save it and provide an access function so code which has performed a walk can query it. A few notes on the accessor interface: - the bitmap code calls these "haves" because it grew out of the want/have negotiation for fetches. But really, these are simply the objects that would be flagged UNINTERESTING in a regular traversal. Let's use that more universal nomenclature for the external module interface. We may want to change the internal naming inside the bitmap code, but that's outside the scope of this patch. - it still uses a bare "sha1" rather than "oid". That's true of all of the bitmap code. And in this particular instance, our caller in pack-objects is dealing with the bare sha1 that comes from a packed REF_DELTA (we're pointing directly to the mmap'd pack on disk). That's something we'll have to deal with as we transition to a new hash, but we can wait and see how the caller ends up being fixed and adjust this interface accordingly. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 22:07:01 +03:00
if (pos < 0)
return 0;
return bitmap_get(bitmap_git->haves, pos);
}