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Автор SHA1 Сообщение Дата
Junio C Hamano 90891c6a0a Merge branch 'ds/object-info-for-prefetch-fix' into maint
Code cleanup and futureproof.

* ds/object-info-for-prefetch-fix:
  sha1-file: split OBJECT_INFO_FOR_PREFETCH
2019-07-25 14:27:08 -07:00
Derrick Stolee 31f5256c82 sha1-file: split OBJECT_INFO_FOR_PREFETCH
The OBJECT_INFO_FOR_PREFETCH bitflag was added to sha1-file.c in 0f4a4fb1
(sha1-file: support OBJECT_INFO_FOR_PREFETCH, 2019-03-29) and is used to
prevent the fetch_objects() method when enabled.

However, there is a problem with the current use. The definition of
OBJECT_INFO_FOR_PREFETCH is given by adding 32 to OBJECT_INFO_QUICK. This is
clearly stated above the definition (in a comment) that this is so
OBJECT_INFO_FOR_PREFETCH implies OBJECT_INFO_QUICK. The problem is that using
"flag & OBJECT_INFO_FOR_PREFETCH" means that OBJECT_INFO_QUICK also implies
OBJECT_INFO_FOR_PREFETCH.

Split out the single bit from OBJECT_INFO_FOR_PREFETCH into a new
OBJECT_INFO_SKIP_FETCH_OBJECT as the single bit and keep
OBJECT_INFO_FOR_PREFETCH as the union of two flags. This allows a clearer use
of flag checking while also keeping the implication of OBJECT_INFO_QUICK.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-28 13:31:50 -07:00
Junio C Hamano 454b419729 Merge branch 'ds/midx-too-many-packs'
The code to generate the multi-pack idx file was not prepared to
see too many packfiles and ran out of open file descriptor, which
has been corrected.

* ds/midx-too-many-packs:
  midx: add packs to packed_git linked list
  midx: pass a repository pointer
2019-05-19 16:45:30 +09:00
Junio C Hamano 4aeeef3773 Merge branch 'dl/no-extern-in-func-decl'
Mechanically and systematically drop "extern" from function
declarlation.

* dl/no-extern-in-func-decl:
  *.[ch]: manually align parameter lists
  *.[ch]: remove extern from function declarations using sed
  *.[ch]: remove extern from function declarations using spatch
2019-05-13 23:50:32 +09:00
Derrick Stolee af96fe3392 midx: add packs to packed_git linked list
The multi-pack-index allows searching for objects across multiple
packs using one object list. The original design gains many of
these performance benefits by keeping the packs in the
multi-pack-index out of the packed_git list.

Unfortunately, this has one major drawback. If the multi-pack-index
covers thousands of packs, and a command loads many of those packs,
then we can hit the limit for open file descriptors. The
close_one_pack() method is used to limit this resource, but it
only looks at the packed_git list, and uses an LRU cache to prevent
thrashing.

Instead of complicating this close_one_pack() logic to include
direct references to the multi-pack-index, simply add the packs
opened by the multi-pack-index to the packed_git list. This
immediately solves the file-descriptor limit problem, but requires
some extra steps to avoid performance issues or other problems:

1. Create a multi_pack_index bit in the packed_git struct that is
   one if and only if the pack was loaded from a multi-pack-index.

2. Skip packs with the multi_pack_index bit when doing object
   lookups and abbreviations. These algorithms already check the
   multi-pack-index before the packed_git struct. This has a very
   small performance hit, as we need to walk more packed_git
   structs. This is acceptable, since these operations run binary
   search on the other packs, so this walk-and-ignore logic is
   very fast by comparison.

3. When closing a multi-pack-index file, do not close its packs,
   as those packs will be closed using close_all_packs(). In some
   cases, such as 'git repack', we run 'close_midx()' without also
   closing the packs, so we need to un-set the multi_pack_index bit
   in those packs. This is necessary, and caught by running
   t6501-freshen-objects.sh with GIT_TEST_MULTI_PACK_INDEX=1.

To manually test this change, I inserted trace2 logging into
close_pack_fd() and set pack_max_fds to 10, then ran 'git rev-list
--all --objects' on a copy of the Git repo with 300+ pack-files and
a multi-pack-index. The logs verified the packs are closed as
we read them beyond the file descriptor limit.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-07 13:48:42 +09:00
Denton Liu ad6dad0996 *.[ch]: manually align parameter lists
In previous patches, extern was mechanically removed from function
declarations without care to formatting, causing parameter lists to be
misaligned. Manually format changed sections such that the parameter
lists should be realigned.

Viewing this patch with 'git diff -w' should produce no output.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-05 15:20:10 +09:00
Denton Liu 554544276a *.[ch]: remove extern from function declarations using spatch
There has been a push to remove extern from function declarations.
Remove some instances of "extern" for function declarations which are
caught by Coccinelle. Note that Coccinelle has some difficulty with
processing functions with `__attribute__` or varargs so some `extern`
declarations are left behind to be dealt with in a future patch.

This was the Coccinelle patch used:

	@@
	type T;
	identifier f;
	@@
	- extern
	  T f(...);

and it was run with:

	$ git ls-files \*.{c,h} |
		grep -v ^compat/ |
		xargs spatch --sp-file contrib/coccinelle/noextern.cocci --in-place

Files under `compat/` are intentionally excluded as some are directly
copied from external sources and we should avoid churning them as much
as possible.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-05 15:20:06 +09:00
Junio C Hamano 32dc15dec1 Merge branch 'jt/batch-fetch-blobs-in-diff'
While running "git diff" in a lazy clone, we can upfront know which
missing blobs we will need, instead of waiting for the on-demand
machinery to discover them one by one.  Aim to achieve better
performance by batching the request for these promised blobs.

* jt/batch-fetch-blobs-in-diff:
  diff: batch fetching of missing blobs
  sha1-file: support OBJECT_INFO_FOR_PREFETCH
2019-04-25 16:41:19 +09:00
Jonathan Tan 0f4a4fb1c4 sha1-file: support OBJECT_INFO_FOR_PREFETCH
Teach oid_object_info_extended() to support a new flag that inhibits
fetching of missing objects. This is equivalent to setting
fetch_is_missing to 0, calling oid_object_info_extended(), then setting
fetch_if_missing to whatever it was before. Update unpack-trees.c to use
this new flag instead of repeatedly setting fetch_if_missing.

This new flag complicates things slightly in that there are now 2 ways
to do the same thing. But this eliminates the need to repeatedly set a
global variable, and more importantly, allows prefetching to be done in
parallel (in the future); hence, this patch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01 15:47:15 +09:00
brian m. carlson 538b152324 object-store: rename and expand packed_git's sha1 member
This member is used to represent the pack checksum of the pack in
question.  Expand this member to be GIT_MAX_RAWSZ bytes in length so it
works with longer hashes and rename it to be "hash" instead of "sha1".
This transformation was made with a change to the definition and the
following semantic patch:

@@
struct packed_git *E1;
@@
- E1->sha1
+ E1->hash

@@
struct packed_git E1;
@@
- E1.sha1
+ E1.hash

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01 11:57:38 +09:00
Junio C Hamano cba595ab1a Merge branch 'jk/loose-object-cache-oid'
Code clean-up.

* jk/loose-object-cache-oid:
  prefer "hash mismatch" to "sha1 mismatch"
  sha1-file: avoid "sha1 file" for generic use in messages
  sha1-file: prefer "loose object file" to "sha1 file" in messages
  sha1-file: drop has_sha1_file()
  convert has_sha1_file() callers to has_object_file()
  sha1-file: convert pass-through functions to object_id
  sha1-file: modernize loose header/stream functions
  sha1-file: modernize loose object file functions
  http: use struct object_id instead of bare sha1
  update comment references to sha1_object_info()
  sha1-file: fix outdated sha1 comment references
2019-02-06 22:05:27 -08:00
Junio C Hamano b99a579f8e Merge branch 'sb/more-repo-in-api'
The in-core repository instances are passed through more codepaths.

* sb/more-repo-in-api: (23 commits)
  t/helper/test-repository: celebrate independence from the_repository
  path.h: make REPO_GIT_PATH_FUNC repository agnostic
  commit: prepare free_commit_buffer and release_commit_memory for any repo
  commit-graph: convert remaining functions to handle any repo
  submodule: don't add submodule as odb for push
  submodule: use submodule repos for object lookup
  pretty: prepare format_commit_message to handle arbitrary repositories
  commit: prepare logmsg_reencode to handle arbitrary repositories
  commit: prepare repo_unuse_commit_buffer to handle any repo
  commit: prepare get_commit_buffer to handle any repo
  commit-reach: prepare in_merge_bases[_many] to handle any repo
  commit-reach: prepare get_merge_bases to handle any repo
  commit-reach.c: allow get_merge_bases_many_0 to handle any repo
  commit-reach.c: allow remove_redundant to handle any repo
  commit-reach.c: allow merge_bases_many to handle any repo
  commit-reach.c: allow paint_down_to_common to handle any repo
  commit: allow parse_commit* to handle any repo
  object: parse_object to honor its repository argument
  object-store: prepare has_{sha1, object}_file to handle any repo
  object-store: prepare read_object_file to deal with any repo
  ...
2019-02-05 14:26:09 -08:00
Jeff King 5d3679ee02 sha1-file: drop has_sha1_file()
There are no callers left of has_sha1_file() or its with_flags()
variant. Let's drop them, and convert has_object_file() from a wrapper
into the "real" function. Ironically, the sha1 variant was just copying
into an object_id internally, so the resulting code is actually shorter!

We can also drop the coccinelle rules for catching has_sha1_file()
callers. Since the function no longer exists, the compiler will do that
for us.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:41:06 -08:00
René Scharfe 8be88dbcb1 object-store: retire odb_load_loose_cache()
Inline odb_load_loose_cache() into its only remaining caller,
odb_loose_cache().  The latter offers a nicer interface for loading the
cache, as it doesn't require callers to deal with fanout directory
numbers directly.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:40:19 -08:00
René Scharfe 4cea1ce0f6 object-store: use one oid_array per subdirectory for loose cache
The loose objects cache is filled one subdirectory at a time as needed.
It is stored in an oid_array, which has to be resorted after each add
operation.  So when querying a wide range of objects, the partially
filled array needs to be resorted up to 255 times, which takes over 100
times longer than sorting once.

Use one oid_array for each subdirectory.  This ensures that entries have
to only be sorted a single time.  It also avoids eight binary search
steps for each cache lookup as a small bonus.

The cache is used for collision checks for the log placeholders %h, %t
and %p, and we can see the change speeding them up in a repository with
ca. 100 objects per subdirectory:

$ git count-objects
26733 objects, 68808 kilobytes

Test                        HEAD^             HEAD
--------------------------------------------------------------------
4205.1: log with %H         0.51(0.47+0.04)   0.51(0.49+0.02) +0.0%
4205.2: log with %h         0.84(0.82+0.02)   0.60(0.57+0.03) -28.6%
4205.3: log with %T         0.53(0.49+0.04)   0.52(0.48+0.03) -1.9%
4205.4: log with %t         0.84(0.80+0.04)   0.60(0.59+0.01) -28.6%
4205.5: log with %P         0.52(0.48+0.03)   0.51(0.50+0.01) -1.9%
4205.6: log with %p         0.85(0.78+0.06)   0.61(0.56+0.05) -28.2%
4205.7: log with %h-%h-%h   0.96(0.92+0.03)   0.69(0.64+0.04) -28.1%

Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:40:19 -08:00
Jeff King 514c5fdd03 sha1-file: modernize loose object file functions
The loose object access code in sha1-file.c is some of the oldest in
Git, and could use some modernizing. It mostly uses "unsigned char *"
for object ids, which these days should be "struct object_id".

It also uses the term "sha1_file" in many functions, which is confusing.
The term "loose_objects" is much better. It clearly distinguishes
them from packed objects (which didn't even exist back when the name
"sha1_file" came into being). And it also distinguishes it from the
checksummed-file concept in csum-file.c (which until recently was
actually called "struct sha1file"!).

This patch converts the functions {open,close,map,stat}_sha1_file() into
open_loose_object(), etc, and switches their sha1 arguments for
object_id structs. Similarly, path functions like fill_sha1_path()
become fill_loose_path() and use object_ids.

The function sha1_loose_object_info() already says "loose", so we can
just drop the "sha1" (and teach it to use object_id).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:40:19 -08:00
René Scharfe d4e19e5163 object-store: factor out odb_clear_loose_cache()
Add and use a function for emptying the loose object cache, so callers
don't have to know any of its implementation details.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:40:19 -08:00
René Scharfe 0000d6543f object-store: factor out odb_loose_cache()
Add and use a function for loading the entries of a loose object
subdirectory for a given object ID.  It frees callers from deriving the
fanout key; they can use the returned oid_array reference for lookups or
forward range scans.

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>
2019-01-08 09:40:19 -08:00
Stefan Beller 9b45f49981 object-store: prepare has_{sha1, object}_file to handle any repo
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14 17:22:40 +09:00
Stefan Beller afd69dcc21 object-store: prepare read_object_file to deal with any repo
As read_object_file is a widely used function (which is also regularly used
in new code in flight between master..pu), changing its signature is painful
is hard, as other series in flight rely on the original signature. It would
burden the maintainer if we'd just change the signature.

Introduce repo_read_object_file which takes the repository argument, and
hide the original read_object_file as a macro behind
NO_THE_REPOSITORY_COMPATIBILITY_MACROS, similar to
e675765235 (diff.c: remove implicit dependency on the_index, 2018-09-21)

Add a coccinelle patch to convert existing callers, but do not apply
the resulting patch to keep the diff of this patch small.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14 17:22:40 +09:00
Stefan Beller a3b72c89bd object-store: allow read_object_file_extended to read from any repo
read_object_file_extended is not widely used, so migrate it all at once.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14 17:22:40 +09:00
Jeff King 61c7711cfe sha1-file: use loose object cache for quick existence check
In cases where we expect to ask has_sha1_file() about a lot of objects
that we are not likely to have (e.g., during fetch negotiation), we
already use OBJECT_INFO_QUICK to sacrifice accuracy (due to racing with
a simultaneous write or repack) for speed (we avoid re-scanning the pack
directory).

However, even checking for loose objects can be expensive, as we will
stat() each one. On many systems this cost isn't too noticeable, but
stat() can be particularly slow on some operating systems, or due to
network filesystems.

Since the QUICK flag already tells us that we're OK with a slightly
stale answer, we can use that as a cue to look in our in-memory cache of
each object directory. That basically trades an in-memory binary search
for a stat() call.

Note that it is possible for this to actually be _slower_. We'll do a
full readdir() to fill the cache, so if you have a very large number of
loose objects and a very small number of lookups, that readdir() may end
up more expensive.

This shouldn't be a big deal in practice. If you have a large number of
reachable loose objects, you'll already run into performance problems
(which you should remedy by repacking). You may have unreachable objects
which wouldn't otherwise impact performance. Usually these would go away
with the prune step of "git gc", but they may be held for up to 2 weeks
in the default configuration.

So it comes down to how many such objects you might reasonably expect to
have, how much slower is readdir() on N entries versus M stat() calls
(and here we really care about the syscall backing readdir(), like
getdents() on Linux, but I'll just call this readdir() below).

If N is much smaller than M (a typical packed repo), we know this is a
big win (few readdirs() followed by many uses of the resulting cache).
When N and M are similar in size, it's also a win. We care about the
latency of making a syscall, and readdir() should be giving us many
values in a single call. How many?

On Linux, running "strace -e getdents ls" shows a 32k buffer getting 512
entries per call (which is 64 bytes per entry; the name itself is 38
bytes, plus there are some other fields). So we can imagine that this is
always a win as long as the number of loose objects in the repository is
a factor of 500 less than the number of lookups you make. It's hard to
auto-tune this because we don't generally know up front how many lookups
we're going to do. But it's unlikely for this to perform significantly
worse.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-13 14:22:03 +09:00
Jeff King 3a2e08245c object-store: provide helpers for loose_objects_cache
Our object_directory struct has a loose objects cache that all users of
the struct can see. But the only one that knows how to load the cache is
find_short_object_filename(). Let's extract that logic in to a reusable
function.

While we're at it, let's also reset the cache when we re-read the object
directories. This shouldn't have an impact on performance, as re-reads
are meant to be rare (and are already expensive, so we avoid them with
things like OBJECT_INFO_QUICK).

Since the cache is already meant to be an approximation, it's tempting
to skip even this bit of safety. But it's necessary to allow more code
to use it. For instance, fetch-pack explicitly re-reads the object
directory after performing its fetch, and would be confused if we didn't
clear the cache.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-13 14:22:03 +09:00
Jeff King f0eaf63819 sha1-file: use an object_directory for the main object dir
Our handling of alternate object directories is needlessly different
from the main object directory. As a result, many places in the code
basically look like this:

  do_something(r->objects->objdir);

  for (odb = r->objects->alt_odb_list; odb; odb = odb->next)
        do_something(odb->path);

That gets annoying when do_something() is non-trivial, and we've
resorted to gross hacks like creating fake alternates (see
find_short_object_filename()).

Instead, let's give each raw_object_store a unified list of
object_directory structs. The first will be the main store, and
everything after is an alternate. Very few callers even care about the
distinction, and can just loop over the whole list (and those who care
can just treat the first element differently).

A few observations:

  - we don't need r->objects->objectdir anymore, and can just
    mechanically convert that to r->objects->odb->path

  - object_directory's path field needs to become a real pointer rather
    than a FLEX_ARRAY, in order to fill it with expand_base_dir()

  - we'll call prepare_alt_odb() earlier in many functions (i.e.,
    outside of the loop). This may result in us calling it even when our
    function would be satisfied looking only at the main odb.

    But this doesn't matter in practice. It's not a very expensive
    operation in the first place, and in the majority of cases it will
    be a noop. We call it already (and cache its results) in
    prepare_packed_git(), and we'll generally check packs before loose
    objects. So essentially every program is going to call it
    immediately once per program.

    Arguably we should just prepare_alt_odb() immediately upon setting
    up the repository's object directory, which would save us sprinkling
    calls throughout the code base (and forgetting to do so has been a
    source of subtle bugs in the past). But I've stopped short of that
    here, since there are already a lot of other moving parts in this
    patch.

  - Most call sites just get shorter. The check_and_freshen() functions
    are an exception, because they have entry points to handle local and
    nonlocal directories separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-13 14:22:03 +09:00
Jeff King f3f043a103 handle alternates paths the same as the main object dir
When we generate loose file paths for the main object directory, the
caller provides a buffer to loose_object_path (formerly sha1_file_name).
The callers generally keep their own static buffer to avoid excessive
reallocations.

But for alternate directories, each struct carries its own scratch
buffer. This is needlessly different; let's unify them.

We could go either direction here, but this patch moves the alternates
struct over to the main directory style (rather than vice-versa).
Technically the alternates style is more efficient, as it avoids
rewriting the object directory name on each call. But this is unlikely
to matter in practice, as we avoid reallocations either way (and nobody
has ever noticed or complained that the main object directory is copying
a few extra bytes before making a much more expensive system call).

And this has the advantage that the reusable buffers are tied to
particular calls, which makes the invalidation rules simpler (for
example, the return value from stat_sha1_file() used to be invalidated
by basically any other object call, but now it is affected only by other
calls to stat_sha1_file()).

We do steal the trick from alt_sha1_path() of returning a pointer to the
filled buffer, which makes a few conversions more convenient.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-13 14:22:02 +09:00
Jeff King b69fb867b4 sha1_file_name(): overwrite buffer instead of appending
The sha1_file_name() function is used to generate the path to a loose
object in the object directory. It doesn't make much sense for it to
append, since the the path we write may be absolute (i.e., you cannot
reliably build up a path with it). Because many callers use it with a
static buffer, they have to strbuf_reset() manually before each call
(and the other callers always use an empty buffer, so they don't care
either way). Let's handle this automatically.

Since we're changing the semantics, let's take the opportunity to give
it a more hash-neutral name (which will also catch any callers from
topics in flight).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-13 14:22:02 +09:00
Jeff King 263db403fa rename "alternate_object_database" to "object_directory"
In preparation for unifying the handling of alt odb's and the normal
repo object directory, let's use a more neutral name. This patch is
purely mechanical, swapping the type name, and converting any variables
named "alt" to "odb". There should be no functional change, but it will
reduce the noise in subsequent diffs.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-13 14:22:02 +09:00
Derrick Stolee 0bff5269d3 packfile: add all_packs list
If a repo contains a multi-pack-index, then the packed_git list
does not contain the packfiles that are covered by the multi-pack-index.
This is important for doing object lookups, abbreviations, and
approximating object count. However, there are many operations that
really want to iterate over all packfiles.

Create a new 'all_packs' linked list that contains this list, starting
with the packfiles in the multi-pack-index and then continuing along
the packed_git linked list.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-20 15:31:40 -07:00
Junio C Hamano c00ba2233e Sync 'ds/multi-pack-index' to v2.19.0-rc0
* ds/multi-pack-index: (23 commits)
  midx: clear midx on repack
  packfile: skip loading index if in multi-pack-index
  midx: prevent duplicate packfile loads
  midx: use midx in approximate_object_count
  midx: use existing midx when writing new one
  midx: use midx in abbreviation calculations
  midx: read objects from multi-pack-index
  config: create core.multiPackIndex setting
  midx: write object offsets
  midx: write object id fanout chunk
  midx: write object ids in a chunk
  midx: sort and deduplicate objects from packfiles
  midx: read pack names into array
  multi-pack-index: write pack names in chunk
  multi-pack-index: read packfile list
  packfile: generalize pack directory list
  t5319: expand test data
  multi-pack-index: load into memory
  midx: write header information to lockfile
  multi-pack-index: add 'write' verb
  ...
2018-08-20 15:29:54 -07:00
Junio C Hamano 5ade034464 Merge branch 'en/incl-forward-decl'
Code hygiene improvement for the header files.

* en/incl-forward-decl:
  Remove forward declaration of an enum
  compat/precompose_utf8.h: use more common include guard style
  urlmatch.h: fix include guard
  Move definition of enum branch_track from cache.h to branch.h
  alloc: make allocate_alloc_state and clear_alloc_state more consistent
  Add missing includes and forward declarations
2018-08-20 12:41:32 -07:00
Elijah Newren ef3ca95475 Add missing includes and forward declarations
I looped over the toplevel header files, creating a temporary two-line C
program for each consisting of
  #include "git-compat-util.h"
  #include $HEADER
This patch is the result of manually fixing errors in compiling those
tiny programs.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-15 11:52:09 -07:00
Jeff King 0889aae1cd for_each_*_object: move declarations to object-store.h
The for_each_loose_object() and for_each_packed_object()
functions are meant to be part of a unified interface: they
use the same set of for_each_object_flags, and it's not
inconceivable that we might one day add a single
for_each_object() wrapper around them.

Let's put them together in a single file, so we can avoid
awkwardness like saying "the flags for this function are
over in cache.h". Moving the loose functions to packfile.h
is silly. Moving the packed functions to cache.h works, but
makes the "cache.h is a kitchen sink" problem worse. The
best place is the recently-created object-store.h, since
these are quite obviously related to object storage.

The for_each_*_in_objdir() functions do not use the same
flags, but they are logically part of the same interface as
for_each_loose_object(), and share callback signatures. So
we'll move those, as well, as they also make sense in
object-store.h.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-14 12:29:57 -07:00
Derrick Stolee c4d25228eb config: create core.multiPackIndex setting
The core.multiPackIndex config setting controls the multi-pack-
index (MIDX) feature. If false, the setting will disable all reads
from the multi-pack-index file.

Read this config setting in the new prepare_multi_pack_index_one()
which is called during prepare_packed_git(). This check is run once
per repository.

Add comparison commands in t5319-multi-pack-index.sh to check
typical Git behavior remains the same as the config setting is turned
on and off. This currently includes 'git rev-list' and 'git log'
commands to trigger several object database reads. Currently, these
would only catch an error in the prepare_multi_pack_index_one(), but
with later commits will catch errors in object lookups, abbreviations,
and approximate object counts.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-20 11:27:28 -07:00
Derrick Stolee 4d80560c54 multi-pack-index: load into memory
Create a new multi_pack_index struct for loading multi-pack-indexes into
memory. Create a test-tool builtin for reading basic information about
that multi-pack-index to verify the correct data is written.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-20 11:27:28 -07:00
Jonathan Tan 8527750626 commit-graph: store graph in struct object_store
Instead of storing commit graphs in static variables, store them in
struct object_store. There are no changes to the signatures of existing
functions - they all still only support the_repository, and support for
other instances of struct repository will be added in a subsequent
commit.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-17 15:47:48 -07:00
Jonathan Tan 14727b7fe6 object-store: add missing include
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-17 15:47:48 -07:00
Junio C Hamano b16b60f71b Merge branch 'sb/object-store-grafts' into sb/object-store-lookup
* sb/object-store-grafts:
  commit: allow lookup_commit_graft to handle arbitrary repositories
  commit: allow prepare_commit_graft to handle arbitrary repositories
  shallow: migrate shallow information into the object parser
  path.c: migrate global git_path_* to take a repository argument
  cache: convert get_graft_file to handle arbitrary repositories
  commit: convert read_graft_file to handle arbitrary repositories
  commit: convert register_commit_graft to handle arbitrary repositories
  commit: convert commit_graft_pos() to handle arbitrary repositories
  shallow: add repository argument to is_repository_shallow
  shallow: add repository argument to check_shallow_file_for_update
  shallow: add repository argument to register_shallow
  shallow: add repository argument to set_alternate_shallow_file
  commit: add repository argument to lookup_commit_graft
  commit: add repository argument to prepare_commit_graft
  commit: add repository argument to read_graft_file
  commit: add repository argument to register_commit_graft
  commit: add repository argument to commit_graft_pos
  object: move grafts to object parser
  object-store: move object access functions to object-store.h
2018-06-29 10:43:28 -07:00
Junio C Hamano ad635e82d6 Merge branch 'nd/pack-objects-pack-struct'
"git pack-objects" needs to allocate tons of "struct object_entry"
while doing its work, and shrinking its size helps the performance
quite a bit.

* nd/pack-objects-pack-struct:
  ci: exercise the whole test suite with uncommon code in pack-objects
  pack-objects: reorder members to shrink struct object_entry
  pack-objects: shrink delta_size field in struct object_entry
  pack-objects: shrink size field in struct object_entry
  pack-objects: clarify the use of object_entry::size
  pack-objects: don't check size when the object is bad
  pack-objects: shrink z_delta_size field in struct object_entry
  pack-objects: refer to delta objects by index instead of pointer
  pack-objects: move in_pack out of struct object_entry
  pack-objects: move in_pack_pos out of struct object_entry
  pack-objects: use bitfield for object_entry::depth
  pack-objects: use bitfield for object_entry::dfs_state
  pack-objects: turn type and in_pack_type to bitfields
  pack-objects: a bit of document about struct object_entry
  read-cache.c: make $GIT_TEST_SPLIT_INDEX boolean
2018-05-23 14:38:19 +09:00
Junio C Hamano 30b015bffe Merge branch 'nd/repack-keep-pack'
"git gc" in a large repository takes a lot of time as it considers
to repack all objects into one pack by default.  The command has
been taught to pretend as if the largest existing packfile is
marked with ".keep" so that it is left untouched while objects in
other packs and loose ones are repacked.

* nd/repack-keep-pack:
  pack-objects: show some progress when counting kept objects
  gc --auto: exclude base pack if not enough mem to "repack -ad"
  gc: handle a corner case in gc.bigPackThreshold
  gc: add gc.bigPackThreshold config
  gc: add --keep-largest-pack option
  repack: add --keep-pack option
  t7700: have closing quote of a test at the beginning of line
2018-05-23 14:38:14 +09:00
Stefan Beller cbd53a2193 object-store: move object access functions to object-store.h
This should make these functions easier to find and cache.h less
overwhelming to read.

In particular, this moves:
- read_object_file
- oid_object_info
- write_object_file

As a result, most of the codebase needs to #include object-store.h.
In this patch the #include is only added to files that would fail to
compile otherwise.  It would be better to #include wherever
identifiers from the header are used.  That can happen later
when we have better tooling for it.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:42:03 +09:00
Nguyễn Thái Ngọc Duy ed7e5fc3a2 repack: add --keep-pack option
We allow to keep existing packs by having companion .keep files. This
is helpful when a pack is permanently kept. In the next patch, git-gc
just wants to keep a pack temporarily, for one pack-objects
run. git-gc can use --keep-pack for this use case.

A note about why the pack_keep field cannot be reused and
pack_keep_in_core has to be added. This is about the case when
--keep-pack is specified together with either --keep-unreachable or
--unpack-unreachable, but --honor-pack-keep is NOT specified.

In this case, we want to exclude objects from the packs specified on
command line, not from ones with .keep files. If only one bit flag is
used, we have to clear pack_keep on pack files with the .keep file.

But we can't make any assumption about unreachable objects in .keep
packs. If "pack_keep" field is false for .keep packs, we could
potentially pull lots of unreachable objects into the new pack, or
unpack them loose. The safer approach is ignore all packs with either
.keep file or --keep-pack.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-16 13:52:29 +09:00
Nguyễn Thái Ngọc Duy 43fa44fa3b pack-objects: move in_pack out of struct object_entry
Instead of using 8 bytes (on 64 bit arch) to store a pointer to a
pack. Use an index instead since the number of packs should be
relatively small.

This limits the number of packs we can handle to 1k. Since we can't be
sure people can never run into the situation where they have more than
1k pack files. Provide a fall back route for it.

If we find out they have too many packs, the new in_pack_by_idx[]
array (which has at most 1k elements) will not be used. Instead we
allocate in_pack[] array that holds nr_objects elements. This is
similar to how the optional in_pack_pos field is handled.

The new simple test is just to make sure the too-many-packs code path
is at least executed. The true test is running

    make test GIT_TEST_FULL_IN_PACK_ARRAY=1

to take advantage of other special case tests.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-16 12:38:58 +09:00
Stefan Beller c1274495ce replace-object: eliminate replace objects prepared flag
Make the oidmap a pointer.

That way we eliminate the need for the global boolean
variable 'replace_object_prepared' as we can put this information
into the pointer being NULL or not.

Another advantage of this is that we would more quickly catch
code that tries to access replace-map without initializing it.

This also allows the '#include "oidmap.h"' introduced in a previous
patch to be replaced by the forward declaration of 'struct oidmap;'.
Keeping the type opaque discourages circumventing accessor functions;
not dragging in other headers avoids some compile time overhead.

One disadvantage of this is change is performance as we need to
pay the overhead for a malloc. The alternative of moving the
global variable into the object store is less modular code.

Helped-by: René Scharfe <l.s.r@web.de>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-12 11:38:56 +09:00
Stefan Beller d88f9fdf8b replace-object: move replace_map to object store
The relationship between an object X and another object Y that
replaces the object X is defined only within the scope of a
single repository.

The exception in reachability rule around these replacement objects
is also local to a repository (i.e. if traversal from refs reaches
X, then both X and Y are reachable and need to be kept from gc).

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-12 11:38:56 +09:00
Stefan Beller bd27f50c80 sha1_file: allow map_sha1_file to handle arbitrary repositories
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-26 10:05:55 -07:00
Stefan Beller a68377b5de sha1_file: allow sha1_file_name to handle arbitrary repositories
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-26 10:05:55 -07:00
Stefan Beller e35454fa62 sha1_file: add repository argument to map_sha1_file
Add a repository argument to allow map_sha1_file callers to be more
specific about which repository to handle. This is a small mechanical
change; it doesn't change the implementation to handle repositories
other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

While at it, move the declaration to object-store.h, where it should
be easier to find.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-26 10:05:55 -07:00
Stefan Beller cf78ae4f3d sha1_file: add repository argument to sha1_file_name
Add a repository argument to allow sha1_file_name callers to be more
specific about which repository to handle. This is a small mechanical
change; it doesn't change the implementation to handle repositories
other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

While at it, move the declaration to object-store.h, where it should
be easier to find.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-26 10:05:55 -07:00
Stefan Beller 13068bf0a0 sha1_file: allow prepare_alt_odb to handle arbitrary repositories
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-26 10:05:55 -07:00
Stefan Beller 77f012e876 sha1_file: allow link_alt_odb_entries to handle arbitrary repositories
Actually this also allows read_info_alternates and link_alt_odb_entry to
handle arbitrary repositories, but link_alt_odb_entries is the most
interesting function in this set of functions, hence the commit subject.

These functions span a strongly connected component in the function
graph, i.e. the recursive call chain might look like

  -> link_alt_odb_entries
    -> link_alt_odb_entry
      -> read_info_alternates
        -> link_alt_odb_entries

That is why we need to convert all these functions at the same time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-26 10:05:55 -07:00