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Автор SHA1 Сообщение Дата
Junio C Hamano 9293bf6f2e Merge branch 'jk/add-ignore-errors-bit-assignment-fix'
A hotfix to an incomplete fix made earlier.

* jk/add-ignore-errors-bit-assignment-fix:
  add_to_index(): convert forgotten HASH_RENORMALIZE check
2019-02-06 22:05:31 -08:00
Junio C Hamano 7589e63648 Merge branch 'nd/the-index-final'
The assumption to work on the single "in-core index" instance has
been reduced from the library-ish part of the codebase.

* nd/the-index-final:
  cache.h: flip NO_THE_INDEX_COMPATIBILITY_MACROS switch
  read-cache.c: remove the_* from index_has_changes()
  merge-recursive.c: remove implicit dependency on the_repository
  merge-recursive.c: remove implicit dependency on the_index
  sha1-name.c: remove implicit dependency on the_index
  read-cache.c: replace update_index_if_able with repo_&
  read-cache.c: kill read_index()
  checkout: avoid the_index when possible
  repository.c: replace hold_locked_index() with repo_hold_locked_index()
  notes-utils.c: remove the_repository references
  grep: use grep_opt->repo instead of explict repo argument
2019-02-06 22:05:23 -08:00
Jeff King e2c2a37545 add_to_index(): convert forgotten HASH_RENORMALIZE check
Commit 9e5da3d055 (add: use separate ADD_CACHE_RENORMALIZE flag,
2019-01-17) switched out using HASH_RENORMALIZE in our flags field for a
new ADD_CACHE_RENORMALIZE flag. However, it forgot to convert one of the
checks for HASH_RENORMALIZE into the new flag, which totally broke "git
add --renormalize".

To make matters even more confusing, the resulting code would racily
pass the tests!  The forgotten check was responsible for defeating the
up-to-date check of the index entry. That meant that "git add
--renormalize" would refuse to renormalize things that appeared
stat-clean. But most of the time the test commands run fast enough that
the file mtime is the same as the index mtime. And thus we err on the
conservative side and re-hash the file, which is what "--renormalize"
would have wanted.

But if you're unlucky and cross that one-second boundary between writing
the file and writing the index (which is more likely to happen on a slow
or heavily-loaded system), then the file appears stat-clean. And
"--renormalize" would effectively do nothing.

The fix is straightforward: convert this check to use the right flag.

Noticed-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-06 18:56:45 -08:00
Junio C Hamano 1c418243a5 Merge branch 'jk/add-ignore-errors-bit-assignment-fix'
"git add --ignore-errors" did not work as advertised and instead
worked as an unintended synonym for "git add --renormalize", which
has been fixed.

* jk/add-ignore-errors-bit-assignment-fix:
  add: use separate ADD_CACHE_RENORMALIZE flag
2019-02-05 14:26:13 -08:00
Nguyễn Thái Ngọc Duy f8adbec9fe cache.h: flip NO_THE_INDEX_COMPATIBILITY_MACROS switch
By default, index compat macros are off from now on, because they
could hide the_index dependency.

Only those in builtin can use it.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-24 11:55:06 -08:00
Jeff King 9e5da3d055 add: use separate ADD_CACHE_RENORMALIZE flag
Commit 9472935d81 (add: introduce "--renormalize", 2017-11-16) taught
git-add to pass HASH_RENORMALIZE to add_to_index(), which then passes
the flag along to index_path(). However, the flags taken by
add_to_index() and the ones taken by index_path() are distinct
namespaces. We cannot take HASH_* flags in add_to_index(), because they
overlap with the ADD_CACHE_* flags we already take (in this case,
HASH_RENORMALIZE conflicts with ADD_CACHE_IGNORE_ERRORS).

We can solve this by adding a new ADD_CACHE_RENORMALIZE flag, and using
it to set HASH_RENORMALIZE within add_to_index(). In order to make it
clear that these two flags come from distinct sets, let's also change
the name "newflags" in the function to "hash_flags".

Reported-by: Dmitriy Smirnov <dmitriy.smirnov@jetbrains.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-17 13:40:21 -08:00
Junio C Hamano f2b6aa98be Merge branch 'nd/indentation-fix'
Code cleanup.

* nd/indentation-fix:
  Indent code with TABs
2019-01-14 15:29:32 -08:00
Nguyễn Thái Ngọc Duy 150fe065f7 read-cache.c: remove the_* from index_has_changes()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-14 12:13:05 -08:00
Nguyễn Thái Ngọc Duy 1b0d968b34 read-cache.c: replace update_index_if_able with repo_&
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-14 12:13:04 -08:00
Nguyễn Thái Ngọc Duy e1ff0a32e4 read-cache.c: kill read_index()
read_index() shares the same problem as hold_locked_index(): it
assumes $GIT_DIR/index. Move all call sites to repo_read_index()
instead. read_index_preload() and read_index_unmerged() are also
killed as a consequence.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-14 12:13:04 -08:00
Nguyễn Thái Ngọc Duy 3a95f31d1c repository.c: replace hold_locked_index() with repo_hold_locked_index()
hold_locked_index() assumes the index path at $GIT_DIR/index. This is
not good for places that take an arbitrary index_state instead of
the_index, which is basically everywhere except builtin/.

Replace it with repo_hold_locked_index(). hold_locked_index() remains
as a wrapper around repo_hold_locked_index() to reduce changes in builtin/

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-14 12:13:04 -08:00
Junio C Hamano cde555480b Merge branch 'nd/the-index'
More codepaths become aware of working with in-core repository
instance other than the default "the_repository".

* nd/the-index: (22 commits)
  rebase-interactive.c: remove the_repository references
  rerere.c: remove the_repository references
  pack-*.c: remove the_repository references
  pack-check.c: remove the_repository references
  notes-cache.c: remove the_repository references
  line-log.c: remove the_repository reference
  diff-lib.c: remove the_repository references
  delta-islands.c: remove the_repository references
  cache-tree.c: remove the_repository references
  bundle.c: remove the_repository references
  branch.c: remove the_repository reference
  bisect.c: remove the_repository reference
  blame.c: remove implicit dependency the_repository
  sequencer.c: remove implicit dependency on the_repository
  sequencer.c: remove implicit dependency on the_index
  transport.c: remove implicit dependency on the_index
  notes-merge.c: remove implicit dependency the_repository
  notes-merge.c: remove implicit dependency on the_index
  list-objects.c: reduce the_repository references
  list-objects-filter.c: remove implicit dependency on the_index
  ...
2019-01-04 13:33:33 -08:00
Junio C Hamano 3813a89fae Merge branch 'nd/i18n'
More _("i18n") markings.

* nd/i18n:
  fsck: mark strings for translation
  fsck: reduce word legos to help i18n
  parse-options.c: mark more strings for translation
  parse-options.c: turn some die() to BUG()
  parse-options: replace opterror() with optname()
  repack: mark more strings for translation
  remote.c: mark messages for translation
  remote.c: turn some error() or die() to BUG()
  reflog: mark strings for translation
  read-cache.c: add missing colon separators
  read-cache.c: mark more strings for translation
  read-cache.c: turn die("internal error") to BUG()
  attr.c: mark more string for translation
  archive.c: mark more strings for translation
  alias.c: mark split_cmdline_strerror() strings for translation
  git.c: mark more strings for translation
2019-01-04 13:33:31 -08:00
Nguyễn Thái Ngọc Duy ec36c42a63 Indent code with TABs
We indent with TABs and sometimes for fine alignment, TABs followed by
spaces, but never all spaces (unless the indentation is less than 8
columns). Indenting with spaces slips through in some places. Fix
them.

Imported code and compat/ are left alone on purpose. The former should
remain as close as upstream as possible. The latter pretty much has
separate maintainers, it's up to them to decide.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-09 12:37:32 +09:00
Junio C Hamano 9fc9555312 Merge branch 'cc/shared-index-permbits'
The way .git/index and .git/sharedindex* files were initially
created gave these files different perm bits until they were
adjusted for shared repository settings.  This was made consistent.

* cc/shared-index-permbits:
  read-cache: make the split index obey umask settings
2018-11-21 20:39:03 +09:00
Jonathan Nieder 2a9dedef2e index: make index.threads=true enable ieot and eoie
If a user explicitly sets

	[index]
		threads = true

to read the index using multiple threads, ensure that index writes
include the offset table by default to make that possible.  This
ensures that the user's intent of turning on threading is respected.

In other words, permit the following configurations:

- index.threads and index.recordOffsetTable unspecified: do not write
  the offset table yet (to avoid alarming the user with "ignoring IEOT
  extension" messages when an older version of Git accesses the
  repository) but do make use of multiple threads to read the index if
  the supporting offset table is present.

  This can also be requested explicitly by setting index.threads=true,
  0, or >1 and index.recordOffsetTable=false.

- index.threads=false or 1: do not write the offset table, and do not
  make use of the offset table.

  One can set index.recordOffsetTable=false as well, to be more
  explicit.

- index.threads=true, 0, or >1 and index.recordOffsetTable unspecified:
  write the offset table and make use of threads at read time.

  This can also be requested by setting index.threads=true, 0, >1, or
  unspecified and index.recordOffsetTable=true.

Fortunately the complication is temporary: once most Git installations
have upgraded to a version with support for the IEOT and EOIE
extensions, we can flip the defaults for index.recordEndOfIndexEntries
and index.recordOffsetTable to true and eliminate the settings.

Helped-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-21 16:46:54 +09:00
Jonathan Nieder 429160544d ieot: default to not writing IEOT section
As with EOIE, popular versions of Git do not support the new IEOT
extension yet.  When accessing a Git repository written by a more
modern version of Git, they correctly ignore the unrecognized section,
but in the process they loudly warn

	ignoring IEOT extension

resulting in confusion for users.  Introduce the index extension more
gently by not writing it yet in this first version with support for
it.  Soon, once sufficiently many users are running a modern version
of Git, we can flip the default so users benefit from this index
extension by default.

Introduce a '[index] recordOffsetTable' configuration variable to
control whether the new index extension is written.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-21 13:43:06 +09:00
Jonathan Nieder d8465500c3 eoie: default to not writing EOIE section
Since 3b1d9e04 (eoie: add End of Index Entry (EOIE) extension,
2018-10-10) Git defaults to writing the new EOIE section when writing
out an index file.  Usually that is a good thing because it improves
threaded performance, but when a Git repository is shared with older
versions of Git, it produces a confusing warning:

  $ git status
  ignoring EOIE extension
  HEAD detached at 371ed0defa
  nothing to commit, working tree clean

Let's introduce the new index extension more gently.  First we'll roll
out the new version of Git that understands it, and then once
sufficiently many users are using such a version, we can flip the
default to writing it by default.

Introduce a '[index] recordEndOfIndexEntries' configuration variable
to allow interested users to benefit from this index extension early.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-21 13:43:06 +09:00
Ævar Arnfjörð Bjarmason c9d6c78870 read-cache: make the split index obey umask settings
Make the split index write out its .git/sharedindex_* files with the
same permissions as .git/index. This only changes the behavior when
core.sharedRepository isn't set, i.e. the user's umask settings will
be respected.

This hasn't been the case ever since the split index was originally
implemented in c18b80a0e8 ("update-index: new options to
enable/disable split index mode", 2014-06-13). A mkstemp()-like
function has always been used to create it. First mkstemp() itself,
and then later our own mkstemp()-like in
f6ecc62dbf ("write_shared_index(): use tempfile module", 2015-08-10)

A related bug was fixed in df801f3f9f ("read-cache: use shared perms
when writing shared index", 2017-06-25). Since then the split index
has respected core.sharedRepository.

However, using that setting should not be required simply to make git
obey the user's umask setting. It's intended for the use-case of
overriding whatever that umask is set to. This fixes cases where the
user has e.g. set his umask to 022 on a shared server in anticipation
of other user's needing to run "status", "log" etc. in his repository.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-19 08:29:02 +09:00
Junio C Hamano 26b80a841a Merge branch 'nd/pthreads'
The codebase has been cleaned up to reduce "#ifndef NO_PTHREADS".

* nd/pthreads:
  Clean up pthread_create() error handling
  read-cache.c: initialize copy_len to shut up gcc 8
  read-cache.c: reduce branching based on HAVE_THREADS
  read-cache.c: remove #ifdef NO_PTHREADS
  pack-objects: remove #ifdef NO_PTHREADS
  preload-index.c: remove #ifdef NO_PTHREADS
  grep: clean up num_threads handling
  grep: remove #ifdef NO_PTHREADS
  attr.c: remove #ifdef NO_PTHREADS
  name-hash.c: remove #ifdef NO_PTHREADS
  index-pack: remove #ifdef NO_PTHREADS
  send-pack.c: move async's #ifdef NO_PTHREADS back to run-command.c
  run-command.h: include thread-utils.h instead of pthread.h
  thread-utils: macros to unconditionally compile pthreads API
2018-11-18 18:23:52 +09:00
Junio C Hamano 11aa560de9 Merge branch 'bp/refresh-index-using-preload'
The helper function to refresh the cached stat information in the
in-core index has learned to perform the lstat() part of the
operation in parallel on multi-core platforms.

* bp/refresh-index-using-preload:
  refresh_index: remove unnecessary calls to preload_index()
  speed up refresh_index() by utilizing preload_index()
2018-11-13 22:37:26 +09:00
Nguyễn Thái Ngọc Duy c207e9e1f6 cache-tree.c: remove the_repository references
This case is more interesting than other boring "remove the_repo"
commits because while we need access to the object database, we cannot
simply use r->index because unpack-trees.c can operate on a temporary
index, not $GIT_DIR/index. Ideally we should be able to pass an object
database to lookup_tree() but that ship has sailed.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 14:50:06 +09:00
Nguyễn Thái Ngọc Duy a71806a74c read-cache.c: add missing colon separators
typechange_fmt and added_fmt should have a colon before "needs
update". Align the statements to make it easier to read and see. Also
drop the unnecessary ().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 14:47:09 +09:00
Nguyễn Thái Ngọc Duy 9d0a9e9089 read-cache.c: mark more strings for translation
There are a couple other improvements on these strings as well:

 - add missing colon (as separator)
 - quote paths
 - provide more information on error messages
 - keep first word in lowercase

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 14:47:09 +09:00
Nguyễn Thái Ngọc Duy 391408e532 read-cache.c: turn die("internal error") to BUG()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 14:47:09 +09:00
Junio C Hamano 65f7a3232b Merge branch 'nd/unpack-trees-with-cache-tree'
Trivial bugfix.

* nd/unpack-trees-with-cache-tree:
  read-cache: use of memory after it is freed
2018-11-06 15:50:20 +09:00
Nguyễn Thái Ngọc Duy f5c4a9af45 read-cache.c: initialize copy_len to shut up gcc 8
It was reported that when building with NO_PTHREADS=1,
-Wmaybe-uninitialized is triggered. Just initialize the variable from
the beginning to shut the compiler up (because this warning is enabled
in config.dev)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-05 13:42:11 +09:00
Nguyễn Thái Ngọc Duy 88168b9b43 read-cache.c: reduce branching based on HAVE_THREADS
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-05 13:42:11 +09:00
Nguyễn Thái Ngọc Duy 62e5ee81a3 read-cache.c: remove #ifdef NO_PTHREADS
This is a faithful conversion with no attempt to clean up whatsoever.
Code indentation is left broken. There will be another commit to clean
it up and un-indent if we just indent now. It's just more code noise.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-05 13:42:11 +09:00
Ben Peart 99ce720c33 speed up refresh_index() by utilizing preload_index()
Speed up refresh_index() by utilizing preload_index() to do most of the work
spread across multiple threads.  This works because most cache entries will
get marked CE_UPTODATE so that refresh_cache_ent() can bail out early when
called from within refresh_index().

On a Windows repo with ~200K files, this drops refresh times from 6.64
seconds to 2.87 seconds for a savings of 57%.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-30 11:28:39 +09:00
Junio C Hamano 7a43ab6fb2 Merge branch 'sg/split-index-racefix'
The codepath to support the experimental split-index mode had
remaining "racily clean" issues fixed.

* sg/split-index-racefix:
  split-index: BUG() when cache entry refers to non-existing shared entry
  split-index: smudge and add racily clean cache entries to split index
  split-index: don't compare cached data of entries already marked for split index
  split-index: count the number of deleted entries
  t1700-split-index: date back files to avoid racy situations
  split-index: add tests to demonstrate the racy split index problem
  t1700-split-index: document why FSMONITOR is disabled in this test script
2018-10-26 14:22:10 +09:00
Carlo Marcelo Arenas Belón b42ad7d57d read-cache: use of memory after it is freed
introduced with c46c406ae1 (trace.h: support nested performance tracing)
on Aug 18, 2018 but not affecting maint

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Acked-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-22 12:37:14 +09:00
Junio C Hamano 4d87b38e6c Merge branch 'nd/status-refresh-progress'
"git status" learns to show progress bar when refreshing the index
takes a long time.

* nd/status-refresh-progress:
  status: show progress bar if refreshing the index takes too long
2018-10-19 13:34:03 +09:00
Junio C Hamano e27bfaaee3 Merge branch 'bp/read-cache-parallel'
A new extension to the index file has been introduced, which allows
the file to be read in parallel.

* bp/read-cache-parallel:
  read-cache: load cache entries on worker threads
  ieot: add Index Entry Offset Table (IEOT) extension
  read-cache: load cache extensions on a worker thread
  config: add new index.threads config setting
  eoie: add End of Index Entry (EOIE) extension
  read-cache: clean up casting and byte decoding
  read-cache.c: optimize reading index format v4
2018-10-19 13:34:03 +09:00
Junio C Hamano 11877b9ebe Merge branch 'nd/the-index'
Various codepaths in the core-ish part learn to work on an
arbitrary in-core index structure, not necessarily the default
instance "the_index".

* nd/the-index: (23 commits)
  revision.c: reduce implicit dependency the_repository
  revision.c: remove implicit dependency on the_index
  ws.c: remove implicit dependency on the_index
  tree-diff.c: remove implicit dependency on the_index
  submodule.c: remove implicit dependency on the_index
  line-range.c: remove implicit dependency on the_index
  userdiff.c: remove implicit dependency on the_index
  rerere.c: remove implicit dependency on the_index
  sha1-file.c: remove implicit dependency on the_index
  patch-ids.c: remove implicit dependency on the_index
  merge.c: remove implicit dependency on the_index
  merge-blobs.c: remove implicit dependency on the_index
  ll-merge.c: remove implicit dependency on the_index
  diff-lib.c: remove implicit dependency on the_index
  read-cache.c: remove implicit dependency on the_index
  diff.c: remove implicit dependency on the_index
  grep.c: remove implicit dependency on the_index
  diff.c: remove the_index dependency in textconv() functions
  blame.c: rename "repo" argument to "r"
  combine-diff.c: remove implicit dependency on the_index
  ...
2018-10-19 13:34:02 +09:00
SZEDER Gábor 5581a019ba split-index: smudge and add racily clean cache entries to split index
Ever since the split index feature was introduced [1], refreshing a
split index is prone to a variant of the classic racy git problem.

Consider the following sequence of commands updating the split index
when the shared index contains a racily clean cache entry, i.e. an
entry whose cached stat data matches with the corresponding file in
the worktree and the cached mtime matches that of the index:

  echo "cached content" >file
  git update-index --split-index --add file
  echo "dirty worktree" >file    # size stays the same!
  # ... wait ...
  git update-index --add other-file

Normally, when a non-split index is updated, then do_write_index()
(the function responsible for writing all kinds of indexes, "regular",
split, and shared) recognizes racily clean cache entries, and writes
them with smudged stat data, i.e. with file size set to 0.  When
subsequent git commands read the index, they will notice that the
smudged stat data doesn't match with the file in the worktree, and
then go on to check the file's content and notice its dirtiness.

In the above example, however, in the second 'git update-index'
prepare_to_write_split_index() decides which cache entries stored only
in the shared index should be replaced in the new split index.  Alas,
this function never looks out for racily clean cache entries, and
since the file's stat data in the worktree hasn't changed since the
shared index was written, it won't be replaced in the new split index.
Consequently, do_write_index() doesn't even get this racily clean
cache entry, and can't smudge its stat data.  Subsequent git commands
will then see that the index has more recent mtime than the file and
that the (not smudged) cached stat data still matches with the file in
the worktree, and, ultimately, will erroneously consider the file
clean.

Modify prepare_to_write_split_index() to recognize racily clean cache
entries, and mark them to be added to the split index.  Note that
there are two places where it should check raciness: first those cache
entries that are only stored in the shared index, and then those that
have been copied by unpack_trees() from the shared index while it
constructed a new index.  This way do_write_index() will get these
racily clean cache entries as well, and will then write them with
smudged stat data to the new split index.

This change makes all tests in 't1701-racy-split-index.sh' pass, so
flip the two 'test_expect_failure' tests to success.  Also add the '#'
(as in nr. of trial) to those tests' description that were omitted
when the tests expected failure.

Note that after this change if the index is split when it contains a
racily clean cache entry, then a smudged cache entry will be written
both to the new shared and to the new split indexes.  This doesn't
affect regular git commands: as far as they are concerned this is just
an entry in the split index replacing an outdated entry in the shared
index.  It did affect a few tests in 't1700-split-index.sh', though,
because they actually check which entries are stored in the split
index; a previous patch in this series has already made the necessary
adjustments in 't1700'.  And racily clean cache entries and index
splitting are rare enough to not worry about the resulting duplicated
smudged cache entries, and the additional complexity required to
prevent them is not worth it.

Several tests failed occasionally when the test suite was run with
'GIT_TEST_SPLIT_INDEX=yes'.  Here are those that I managed to trace
back to this racy split index problem, starting with those failing
more frequently, with a link to a failing Travis CI build job for
each.  The highlighted line [2] shows when the racy file was written,
which is not always in the failing test but in a preceeding setup
test.

  t3903-stash.sh:
    https://travis-ci.org/git/git/jobs/385542084#L5858

  t4024-diff-optimize-common.sh:
    https://travis-ci.org/git/git/jobs/386531969#L3174

  t4015-diff-whitespace.sh:
    https://travis-ci.org/git/git/jobs/360797600#L8215

  t2200-add-update.sh:
    https://travis-ci.org/git/git/jobs/382543426#L3051

  t0090-cache-tree.sh:
    https://travis-ci.org/git/git/jobs/416583010#L3679

There might be others, e.g. perhaps 't1000-read-tree-m-3way.sh' and
others using 'lib-read-tree-m-3way.sh', but I couldn't confirm yet.

[1] In the branch leading to the merge commit v2.1.0-rc0~45 (Merge
    branch 'nd/split-index', 2014-07-16).

[2] Note that those highlighted lines are in the 'after failure' fold,
    and your browser might unhelpfully fold it up before you could
    take a good look.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-12 07:23:29 +09:00
Ben Peart 77ff1127a4 read-cache: load cache entries on worker threads
This patch helps address the CPU cost of loading the index by utilizing
the Index Entry Offset Table (IEOT) to divide loading and conversion of
the cache entries across multiple threads in parallel.

I used p0002-read-cache.sh to generate some performance data:

Test w/100,000 files reduced the time by 32.24%
Test w/1,000,000 files reduced the time by -4.77%

Note that on the 1,000,000 files case, multi-threading the cache entry parsing
does not yield a performance win.  This is because the cost to parse the
index extensions in this repo, far outweigh the cost of loading the cache
entries.

The high cost of parsing the index extensions is driven by the cache tree
and the untracked cache extensions. As this is currently the longest pole,
any reduction in this time will reduce the overall index load times so is
worth further investigation in another patch series.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 15:32:48 +09:00
Ben Peart 3255089ada ieot: add Index Entry Offset Table (IEOT) extension
This patch enables addressing the CPU cost of loading the index by adding
additional data to the index that will allow us to efficiently multi-
thread the loading and conversion of cache entries.

It accomplishes this by adding an (optional) index extension that is a
table of offsets to blocks of cache entries in the index file.  To make
this work for V4 indexes, when writing the cache entries, it periodically
"resets" the prefix-compression by encoding the current entry as if the
path name for the previous entry is completely different and saves the
offset of that entry in the IEOT.  Basically, with V4 indexes, it
generates offsets into blocks of prefix-compressed entries.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 15:32:48 +09:00
Ben Peart abb4bb8384 read-cache: load cache extensions on a worker thread
This patch helps address the CPU cost of loading the index by loading
the cache extensions on a worker thread in parallel with loading the cache
entries.

In some cases, loading the extensions takes longer than loading the
cache entries so this patch utilizes the new EOIE to start the thread to
load the extensions before loading all the cache entries in parallel.

This is possible because the current extensions don't access the cache
entries in the index_state structure so are OK that they don't all exist
yet.

The CACHE_EXT_TREE, CACHE_EXT_RESOLVE_UNDO, and CACHE_EXT_UNTRACKED
extensions don't even get a pointer to the index so don't have access to the
cache entries.

CACHE_EXT_LINK only uses the index_state to initialize the split index.
CACHE_EXT_FSMONITOR only uses the index_state to save the fsmonitor last
update and dirty flags.

I used p0002-read-cache.sh to generate some performance data:

	Test w/100,000 files reduced the time by 0.53%
	Test w/1,000,000 files reduced the time by 27.78%

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 15:32:48 +09:00
Ben Peart 3b1d9e045e eoie: add End of Index Entry (EOIE) extension
The End of Index Entry (EOIE) is used to locate the end of the variable
length index entries and the beginning of the extensions. Code can take
advantage of this to quickly locate the index extensions without having
to parse through all of the index entries.

The EOIE extension is always written out to the index file including to
the shared index when using the split index feature. Because it is always
written out, the SHA checksums in t/t1700-split-index.sh were updated
to reflect its inclusion.

It is written as an optional extension to ensure compatibility with other
git implementations that do not yet support it.  It is always written out
to ensure it is available as often as possible to speed up index operations.

Because it must be able to be loaded before the variable length cache
entries and other index extensions, this extension must be written last.
The signature for this extension is { 'E', 'O', 'I', 'E' }.

The extension consists of:

- 32-bit offset to the end of the index entries

- 160-bit SHA-1 over the extension types and their sizes (but not
their contents).  E.g. if we have "TREE" extension that is N-bytes
long, "REUC" extension that is M-bytes long, followed by "EOIE",
then the hash would be:

SHA-1("TREE" + <binary representation of N> +
    "REUC" + <binary representation of M>)

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 15:32:48 +09:00
Ben Peart 371ed0defa read-cache: clean up casting and byte decoding
This patch does a clean up pass to minimize the casting required to work
with the memory mapped index (mmap).

It also makes the decoding of network byte order more consistent by using
get_be32() where possible.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 15:32:48 +09:00
Nguyễn Thái Ngọc Duy 252d079cbd read-cache.c: optimize reading index format v4
Index format v4 requires some more computation to assemble a path
based on a previous one. The current code is not very efficient
because

 - it doubles memory copy, we assemble the final path in a temporary
   first before putting it back to a cache_entry

 - strbuf_remove() in expand_name_field() is not exactly a good fit
   for stripping a part at the end, _setlen() would do the same job
   and is much cheaper.

 - the open-coded loop to find the end of the string in
   expand_name_field() can't beat an optimized strlen()

This patch avoids the temporary buffer and writes directly to the new
cache_entry, which addresses the first two points. The last point
could also be avoided if the total string length fits in the first 12
bits of ce_flags, if not we fall back to strlen().

Running "test-tool read-cache 100" on webkit.git (275k files), reading
v2 only takes 4.226 seconds, while v4 takes 5.711 seconds, 35% more
time. The patch reduces read time on v4 to 4.319 seconds.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-26 15:19:49 -07:00
Nguyễn Thái Ngọc Duy 58bf2a4cc7 sha1-file.c: remove implicit dependency on the_index
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:48:11 -07:00
Nguyễn Thái Ngọc Duy d7b665c363 read-cache.c: remove implicit dependency on the_index
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:48:10 -07:00
Nguyễn Thái Ngọc Duy e675765235 diff.c: remove implicit dependency on the_index
A new variant repo_diff_setup() is added that takes 'struct repository *'
and diff_setup() becomes a thin macro around it that is protected by
NO_THE_REPOSITORY_COMPATIBILITY_MACROS, similar to NO_THE_INDEX_....
The plan is these macros will always be defined for all library files
and the macros are only accessible in builtin/

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:48:10 -07:00
Nguyễn Thái Ngọc Duy 92a1bf5a58 read-cache.c: remove 'const' from index_has_changes()
This function calls do_diff_cache() which eventually needs to set this
"istate" to unpack_options->src_index [1]. This is an unfortunate fact
that unpack_trees() _will_ update [2] src_index so we can't really pass a
const index_state there. Just remove 'const'.

[1] Right now diff_cache() in diff-lib.c assigns the_index to
    src_index. But the plan is to get rid of the_index, so it should
    be 'istate' from here that gets assigned to src_index.

[2] Some transient bits in the source index are touched. Optional
    extensions can also be removed. But other than that the source
    tree should still be valid.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:48:10 -07:00
Junio C Hamano 769af0fd9e Merge branch 'jk/cocci'
spatch transformation to replace boolean uses of !hashcmp() to
newly introduced oideq() is added, and applied, to regain
performance lost due to support of multiple hash algorithms.

* jk/cocci:
  show_dirstat: simplify same-content check
  read-cache: use oideq() in ce_compare functions
  convert hashmap comparison functions to oideq()
  convert "hashcmp() != 0" to "!hasheq()"
  convert "oidcmp() != 0" to "!oideq()"
  convert "hashcmp() == 0" to hasheq()
  convert "oidcmp() == 0" to oideq()
  introduce hasheq() and oideq()
  coccinelle: use <...> for function exclusion
2018-09-17 13:53:57 -07:00
Junio C Hamano 7e794d0a3f Merge branch 'nd/unpack-trees-with-cache-tree'
The unpack_trees() API used in checking out a branch and merging
walks one or more trees along with the index.  When the cache-tree
in the index tells us that we are walking a tree whose flattened
contents is known (i.e. matches a span in the index), as linearly
scanning a span in the index is much more efficient than having to
open tree objects recursively and listing their entries, the walk
can be optimized, which is done in this topic.

* nd/unpack-trees-with-cache-tree:
  Document update for nd/unpack-trees-with-cache-tree
  cache-tree: verify valid cache-tree in the test suite
  unpack-trees: add missing cache invalidation
  unpack-trees: reuse (still valid) cache-tree from src_index
  unpack-trees: reduce malloc in cache-tree walk
  unpack-trees: optimize walking same trees with cache-tree
  unpack-trees: add performance tracing
  trace.h: support nested performance tracing
2018-09-17 13:53:53 -07:00
Nguyễn Thái Ngọc Duy ae9af12287 status: show progress bar if refreshing the index takes too long
Refreshing the index is usually very fast, but it can still take a
long time sometimes. Cold cache is one. Or copying a repo to a new
place (*). It's good to show something to let the user know "git
status" is not hanging, it's just busy doing something.

(*) In this case, all stat info in the index becomes invalid and git
    falls back to rehashing all file content to see if there's any
    difference between updating stat info in the index. This is quite
    expensive. Even with a repo as small as git.git, it takes 3
    seconds.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-17 09:38:50 -07:00
Jeff King 6a29d7b7a7 read-cache: use oideq() in ce_compare functions
These functions return the full oidcmp() value, but the
callers really only care whether it is non-zero. We can use
the more strict !oideq(), which a compiler may be able to
optimize further.

This does change the meaning of the return value subtly, but
it's unlikely that anybody would try to use them for
ordering. They're static-local in this file, and they
already return other error values that would confuse an
ordering (e.g., open() failure gives -1).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00