Commit Graph

648 Commits

Author SHA1 Message Date
Junio C Hamano
0efa3d74e7 Merge branch 'nd/split-index-null-base-fix'
Split-index fix.

* nd/split-index-null-base-fix:
  read-cache.c: fix writing "link" index ext with null base oid
2019-03-07 09:59:56 +09:00
Junio C Hamano
7d0c1f4556 Merge branch 'tg/checkout-no-overlay'
"git checkout --no-overlay" can be used to trigger a new mode of
checking out paths out of the tree-ish, that allows paths that
match the pathspec that are in the current index and working tree
and are not in the tree-ish.

* tg/checkout-no-overlay:
  revert "checkout: introduce checkout.overlayMode config"
  checkout: introduce checkout.overlayMode config
  checkout: introduce --{,no-}overlay option
  checkout: factor out mark_cache_entry_for_checkout function
  checkout: clarify comment
  read-cache: add invalidate parameter to remove_marked_cache_entries
  entry: support CE_WT_REMOVE flag in checkout_entry
  entry: factor out unlink_entry function
  move worktree tests to t24*
2019-03-07 09:59:51 +09:00
Jeff Hostetler
42fee7a388 trace2:data: add trace2 instrumentation to index read/write
Add trace2 events to measure reading and writing the index.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:28:21 -08:00
Ben Peart
1956ecd0ab read-cache: add post-index-change hook
Add a post-index-change hook that is invoked after the index is written in
do_write_locked_index().

This hook is meant primarily for notification, and cannot affect
the outcome of git commands that trigger the index write.

The hook is passed a flag to indicate whether the working directory was
updated or not and a flag indicating if a skip-worktree bit could have
changed.  These flags enable the hook to optimize its response to the
index change notification.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-15 11:00:33 -08:00
Nguyễn Thái Ngọc Duy
6e37c8ed3c read-cache.c: fix writing "link" index ext with null base oid
Since commit 7db118303a (unpack_trees: fix breakage when o->src_index !=
o->dst_index - 2018-04-23) and changes in merge code to use separate
index_state for source and destination, when doing a merge with split
index activated, we may run into this line in unpack_trees():

    o->result.split_index = init_split_index(&o->result);

This is by itself not wrong. But this split index information is not
fully populated (and it's only so when move_cache_to_base_index() is
called, aka force splitting the index, or loading index_state from a
file). Both "base_oid" and "base" in this case remain null.

So when writing the main index down, we link to this index with null
oid (default value after init_split_index()), which also means "no split
index" internally. This triggers an incorrect base index refresh:

    warning: could not freshen shared index '.../sharedindex.0{40}'

This patch makes sure we will not refresh null base_oid (because the
file is never there). It also makes sure not to write "link" extension
with null base_oid in the first place (no point having it at
all). Read code already has protection against null base_oid.

There is also another side fix in remove_split_index() that causes a
crash when doing "git update-index --no-split-index" when base_oid in
the index file is null. In this case we will not load
istate->split_index->base but we dereference it anyway and are rewarded
with a segfault. This should not happen anymore, but it's still wrong to
dereference a potential NULL pointer, especially when we do check for
NULL pointer in the next code.

Reported-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-13 12:52:48 -08:00
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
Thomas Gummerer
6fdc205722 read-cache: add invalidate parameter to remove_marked_cache_entries
When marking cache entries for removal, and later removing them all at
once using 'remove_marked_cache_entries()', cache entries currently
have to be invalidated manually in the cache tree and in the untracked
cache.

Add an invalidate flag to the function.  With the flag set, the
function will take care of invalidating the path in the cache tree and
in the untracked cache.

Note that the current callsites already do the invalidation properly
in other places, so we're just passing 0 from there to keep the status
quo.

This will be useful in a subsequent commit.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-02 15:28:05 -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
Jeff King
67947c34ae convert "hashcmp() != 0" to "!hasheq()"
This rounds out the previous three patches, covering the
inequality logic for the "hash" variant of the functions.

As with the previous three, the accompanying code changes
are the mechanical result of applying the coccinelle patch;
see those patches for more discussion.

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
Jeff King
9001dc2a74 convert "oidcmp() != 0" to "!oideq()"
This is the flip side of the previous two patches: checking
for a non-zero oidcmp() can be more strictly expressed as
inequality. Like those patches, we write "!= 0" in the
coccinelle transformation, which covers by isomorphism the
more common:

  if (oidcmp(E1, E2))

As with the previous two patches, this patch can be achieved
almost entirely by running "make coccicheck"; the only
differences are manual line-wrap fixes to match the original
code.

There is one thing to note for anybody replicating this,
though: coccinelle 1.0.4 seems to miss the case in
builtin/tag.c, even though it's basically the same as all
the others. Running with 1.0.7 does catch this, so
presumably it's just a coccinelle bug that was fixed in the
interim.

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
Jeff King
4a7e27e957 convert "oidcmp() == 0" to oideq()
Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.

The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).

This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.

I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).

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
Junio C Hamano
dc0f6f9e1d Merge branch 'nd/no-the-index'
The more library-ish parts of the codebase learned to work on the
in-core index-state instance that is passed in by their callers,
instead of always working on the singleton "the_index" instance.

* nd/no-the-index: (24 commits)
  blame.c: remove implicit dependency on the_index
  apply.c: remove implicit dependency on the_index
  apply.c: make init_apply_state() take a struct repository
  apply.c: pass struct apply_state to more functions
  resolve-undo.c: use the right index instead of the_index
  archive-*.c: use the right repository
  archive.c: avoid access to the_index
  grep: use the right index instead of the_index
  attr: remove index from git_attr_set_direction()
  entry.c: use the right index instead of the_index
  submodule.c: use the right index instead of the_index
  pathspec.c: use the right index instead of the_index
  unpack-trees: avoid the_index in verify_absent()
  unpack-trees: convert clear_ce_flags* to avoid the_index
  unpack-trees: don't shadow global var the_index
  unpack-trees: add a note about path invalidation
  unpack-trees: remove 'extern' on function declaration
  ls-files: correct index argument to get_convert_attr_ascii()
  preload-index.c: use the right index instead of the_index
  dir.c: remove an implicit dependency on the_index in pathspec code
  ...
2018-08-20 11:33:53 -07:00
Nguyễn Thái Ngọc Duy
4592e6080f cache-tree: verify valid cache-tree in the test suite
This makes sure that cache-tree is consistent with the index. The main
purpose is to catch potential problems by saving the index in
unpack_trees() but the line in write_index() would also help spot
missing invalidation in other code.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-18 09:47:46 -07:00
Nguyễn Thái Ngọc Duy
836ef2b69f unpack-trees: reuse (still valid) cache-tree from src_index
We do n-way merge by walking the source index and n trees at the same
time and add merge results to a new temporary index called o->result.
The merge result for any given path could be either

- keep_entry(): same old index entry in o->src_index is reused
- merged_entry(): either a new entry is added, or an existing one updated
- deleted_entry(): one entry from o->src_index is removed

For some reason [1] we keep making sure that the source index's
cache-tree is still valid if used by o->result: for all those
merged/deleted entries, we invalidate the same path in o->src_index,
so only cache-trees covering the "keep_entry" parts remain good.

Because of this, the cache-tree from o->src_index can be perfectly
reused in o->result. And in fact we already rely on this logic to
reuse untracked cache in edf3b90553 (unpack-trees: preserve index
extensions - 2017-05-08). Move the cache-tree to o->result before
doing cache_tree_update() to reduce hashing cost.

Since cache_tree_update() has risen up as one of the most expensive
parts in unpack_trees() after the last few patches. This does help
reduce unpack_trees() time significantly (on webkit.git):

    before       after
  --------------------------------------------------------------------
    0.080394752  0.051258167 s:  read cache .git/index
    0.216010838  0.212106298 s:  preload index
    0.008534301  0.280521764 s:  refresh index
    0.251992198  0.218160442 s:   traverse_trees
    0.377031383  0.374948191 s:   check_updates
    0.372768105  0.037040114 s:   cache_tree_update
    1.045887251  0.672031609 s:  unpack_trees
    0.314983512  0.317456290 s:  write index, changed mask = 2e
    0.062572653  0.038382654 s:    traverse_trees
    0.000022544  0.000042731 s:    check_updates
    0.073795585  0.050930053 s:   unpack_trees
    0.073807557  0.051099735 s:  diff-index
    1.938191592  1.614241153 s: git command: git checkout -

[1] I'm pretty sure the reason is an oversight in 34110cd4e3 (Make
    'unpack_trees()' have a separate source and destination index -
    2008-03-06). That patch aims to _not_ update the source index at
    all. The invalidation should have been done on o->result in that
    patch. But then there was no cache-tree on o->result even then so
    it's pointless to do so.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-18 09:47:46 -07:00
Nguyễn Thái Ngọc Duy
c46c406ae1 trace.h: support nested performance tracing
Performance measurements are listed right now as a flat list, which is
fine when we measure big blocks. But when we start adding more and
more measurements, some of them could be just part of a bigger
measurement and a flat list gives a wrong impression that they are
executed at the same level instead of nested.

Add trace_performance_enter() and trace_performance_leave() to allow
indent these nested measurements. For now it does not help much
because the only nested thing is (lazy) name hash initialization
(e.g. called in diff-index from "git status"). This will help more
because I'm going to add some more tracing that's actually nested.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-18 09:47:46 -07:00
Junio C Hamano
8ba8642bd5 Merge branch 'en/abort-df-conflict-fixes'
"git merge --abort" etc. did not clean things up properly when
there were conflicted entries in the index in certain order that
are involved in D/F conflicts.  This has been corrected.

* en/abort-df-conflict-fixes:
  read-cache: fix directory/file conflict handling in read_index_unmerged()
  t1015: demonstrate directory/file conflict recovery failures
2018-08-17 13:09:57 -07:00
Nguyễn Thái Ngọc Duy
6d2df284e7 dir.c: remove an implicit dependency on the_index in pathspec code
Make the match_patchspec API and friends take an index_state instead
of assuming the_index in dir.c. All external call sites are converted
blindly to keep the patch simple and retain current behavior.
Individual call sites may receive further updates to use the right
index instead of the_index.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13 14:14:42 -07:00
Junio C Hamano
c18ac30e9e Merge branch 'en/dirty-merge-fixes'
The recursive merge strategy did not properly ensure there was no
change between HEAD and the index before performing its operation,
which has been corrected.

* en/dirty-merge-fixes:
  merge: fix misleading pre-merge check documentation
  merge-recursive: enforce rule that index matches head before merging
  t6044: add more testcases with staged changes before a merge is invoked
  merge-recursive: fix assumption that head tree being merged is HEAD
  merge-recursive: make sure when we say we abort that we actually abort
  t6044: add a testcase for index matching head, when head doesn't match HEAD
  t6044: verify that merges expected to abort actually abort
  index_has_changes(): avoid assuming operating on the_index
  read-cache.c: move index_has_changes() from merge.c
2018-08-02 15:30:45 -07:00
Junio C Hamano
ae533c4a92 Merge branch 'jm/cache-entry-from-mem-pool'
For a large tree, the index needs to hold many cache entries
allocated on heap.  These cache entries are now allocated out of a
dedicated memory pool to amortize malloc(3) overhead.

* jm/cache-entry-from-mem-pool:
  block alloc: add validations around cache_entry lifecyle
  block alloc: allocate cache entries from mem_pool
  mem-pool: fill out functionality
  mem-pool: add life cycle management functions
  mem-pool: only search head block for available space
  block alloc: add lifecycle APIs for cache_entry structs
  read-cache: teach make_cache_entry to take object_id
  read-cache: teach refresh_cache_entry to take istate
2018-08-02 15:30:43 -07:00
Elijah Newren
ad3762042a read-cache: fix directory/file conflict handling in read_index_unmerged()
read_index_unmerged() has two intended purposes:
  * return 1 if there are any unmerged entries, 0 otherwise
  * drops any higher-stage entries down to stage #0

There are several callers of read_index_unmerged() that check the return
value to see if it is non-zero, all of which then die() if that condition
is met.  For these callers, dropping higher-stage entries down to stage #0
is a waste of resources, and returning immediately on first unmerged entry
would be better.  But it's probably only a very minor difference and isn't
the focus of this series.

The remaining callers ignore the return value and call this function for
the side effect of dropping higher-stage entries down to stage #0.  As
mentioned in commit e11d7b5969 ("'reset --merge': fix unmerged case",
2009-12-31),

    The _only_ reason we want to keep a previously unmerged entry in the
    index at stage #0 is so that we don't forget the fact that we have
    corresponding file in the work tree in order to be able to remove it
    when the tree we are resetting to does not have the path.

In fact, prior to commit d1a43f2aa4 ("reset --hard/read-tree --reset -u:
remove unmerged new paths", 2008-10-15), read_index_unmerged() did just
remove unmerged entries from the cache immediately but that had the
unwanted effect of leaving around new untracked files in the tree from
aborted merges.

So, that's the intended purpose of this function.  The problem is that
when directory/files conflicts are present, trying to add the file to the
index at stage 0 fails (because there is still a directory in the way),
and the function returns early with a -1 return code to signify the error.
As noted above, none of the callers who want the drop-to-stage-0 behavior
check the return status, though, so this means all remaining unmerged
entries remain in the index and the callers proceed assuming otherwise.
Users then see errors of the form:

    error: 'DIR-OR-FILE' appears as both a file and as a directory
    error: DIR-OR-FILE: cannot drop to stage #0

and potentially also messages about other unmerged entries which came
lexicographically later than whatever pathname was both a file and a
directory.  Google finds a few hits searching for those messages,
suggesting there were probably a couple people who hit this besides me.
Luckily, calling `git reset --hard` multiple times would workaround
this bug.

Since the whole purpose here is to just put the entry *temporarily* into
the index so that any associated file in the working copy can be removed,
we can just skip the DFCHECK and allow both the file and directory to
appear in the index.  The temporary simultaneous appearance of the
directory and file entries in the index will be removed by the callers
by calling unpack_trees(), which excludes these unmerged entries marked
with CE_CONFLICTED flag from the resulting index, before they attempt to
write the index anywhere.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-31 12:51:11 -07:00
Junio C Hamano
00624d608c Merge branch 'sb/object-store-grafts'
The conversion to pass "the_repository" and then "a_repository"
throughout the object access API continues.

* 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
2018-07-18 12:20:28 -07:00
Elijah Newren
e1f8694f33 merge-recursive: fix assumption that head tree being merged is HEAD
`git merge-recursive` does a three-way merge between user-specified trees
base, head, and remote.  Since the user is allowed to specify head, we can
not necesarily assume that head == HEAD.

Modify index_has_changes() to take an extra argument specifying the tree
to compare against.  If NULL, it will compare to HEAD.  We then use this
from merge-recursive to make sure we compare to the user-specified head.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-11 09:38:36 -07:00
Elijah Newren
1b9fbefbe0 index_has_changes(): avoid assuming operating on the_index
Modify index_has_changes() to take a struct istate* instead of just
operating on the_index.  This is only a partial conversion, though,
because we call do_diff_cache() which implicitly assumes work is to be
done on the_index.  Ongoing work is being done elsewhere to do the
remainder of the conversion, and thus is not duplicated here.  Instead,
a simple check is put in place until that work is complete.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03 13:13:18 -07:00
Elijah Newren
cffbfad50d read-cache.c: move index_has_changes() from merge.c
Since index_has_change() is an index-related function, move it to
read-cache.c, only modifying it to avoid uses of the active_cache and
active_nr macros.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03 13:13:17 -07:00
Jameson Miller
8616a2d0cb block alloc: add validations around cache_entry lifecyle
Add an option (controlled by an environment variable) perform extra
validations on mem_pool allocated cache entries. When set:

  1) Invalidate cache_entry memory when discarding cache_entry.

  2) When discarding index_state struct, verify that all cache_entries
     were allocated from expected mem_pool.

  3) When discarding mem_pools, invalidate mem_pool memory.

This should provide extra checks that mem_pools and their allocated
cache_entries are being used as expected.

Signed-off-by: Jameson Miller <jamill@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03 10:58:27 -07:00
Jameson Miller
8e72d67529 block alloc: allocate cache entries from mem_pool
When reading large indexes from disk, a portion of the time is
dominated in malloc() calls. This can be mitigated by allocating a
large block of memory and manage it ourselves via memory pools.

This change moves the cache entry allocation to be on top of memory
pools.

Design:

The index_state struct will gain a notion of an associated memory_pool
from which cache_entries will be allocated from. When reading in the
index from disk, we have information on the number of entries and
their size, which can guide us in deciding how large our initial
memory allocation should be. When an index is discarded, the
associated memory_pool will be discarded as well - so the lifetime of
a cache_entry is tied to the lifetime of the index_state that it was
allocated for.

In the case of a Split Index, the following rules are followed. 1st,
some terminology is defined:

Terminology:
  - 'the_index': represents the logical view of the index

  - 'split_index': represents the "base" cache entries. Read from the
    split index file.

'the_index' can reference a single split_index, as well as
cache_entries from the split_index. `the_index` will be discarded
before the `split_index` is.  This means that when we are allocating
cache_entries in the presence of a split index, we need to allocate
the entries from the `split_index`'s memory pool.  This allows us to
follow the pattern that `the_index` can reference cache_entries from
the `split_index`, and that the cache_entries will not be freed while
they are still being referenced.

Managing transient cache_entry structs:
Cache entries are usually allocated for an index, but this is not always
the case. Cache entries are sometimes allocated because this is the
type that the existing checkout_entry function works with. Because of
this, the existing code needs to handle cache entries associated with an
index / memory pool, and those that only exist transiently. Several
strategies were contemplated around how to handle this:

Chosen approach:
An extra field was added to the cache_entry type to track whether the
cache_entry was allocated from a memory pool or not. This is currently
an int field, as there are no more available bits in the existing
ce_flags bit field. If / when more bits are needed, this new field can
be turned into a proper bit field.

Alternatives:

1) Do not include any information about how the cache_entry was
allocated. Calling code would be responsible for tracking whether the
cache_entry needed to be freed or not.
  Pro: No extra memory overhead to track this state
  Con: Extra complexity in callers to handle this correctly.

The extra complexity and burden to not regress this behavior in the
future was more than we wanted.

2) cache_entry would gain knowledge about which mem_pool allocated it
  Pro: Could (potentially) do extra logic to know when a mem_pool no
       longer had references to any cache_entry
  Con: cache_entry would grow heavier by a pointer, instead of int

We didn't see a tangible benefit to this approach

3) Do not add any extra information to a cache_entry, but when freeing a
   cache entry, check if the memory exists in a region managed by existing
   mem_pools.
  Pro: No extra memory overhead to track state
  Con: Extra computation is performed when freeing cache entries

We decided tracking and iterating over known memory pool regions was
less desirable than adding an extra field to track this stae.

Signed-off-by: Jameson Miller <jamill@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03 10:58:27 -07:00
Jameson Miller
a849735bfb block alloc: add lifecycle APIs for cache_entry structs
It has been observed that the time spent loading an index with a large
number of entries is partly dominated by malloc() calls. This change
is in preparation for using memory pools to reduce the number of
malloc() calls made to allocate cahce entries when loading an index.

Add an API to allocate and discard cache entries, abstracting the
details of managing the memory backing the cache entries. This commit
does actually change how memory is managed - this will be done in a
later commit in the series.

This change makes the distinction between cache entries that are
associated with an index and cache entries that are not associated with
an index. A main use of cache entries is with an index, and we can
optimize the memory management around this. We still have other cases
where a cache entry is not persisted with an index, and so we need to
handle the "transient" use case as well.

To keep the congnitive overhead of managing the cache entries, there
will only be a single discard function. This means there must be enough
information kept with the cache entry so that we know how to discard
them.

A summary of the main functions in the API is:

make_cache_entry: create cache entry for use in an index. Uses specified
                  parameters to populate cache_entry fields.

make_empty_cache_entry: Create an empty cache entry for use in an index.
                        Returns cache entry with empty fields.

make_transient_cache_entry: create cache entry that is not used in an
                            index. Uses specified parameters to populate
                            cache_entry fields.

make_empty_transient_cache_entry: create cache entry that is not used in
                                  an index. Returns cache entry with
                                  empty fields.

discard_cache_entry: A single function that knows how to discard a cache
                     entry regardless of how it was allocated.

Signed-off-by: Jameson Miller <jamill@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03 10:58:27 -07:00
Jameson Miller
825ed4d9a0 read-cache: teach make_cache_entry to take object_id
Teach make_cache_entry function to take object_id instead of a SHA-1.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03 10:58:15 -07:00
Jameson Miller
768d796506 read-cache: teach refresh_cache_entry to take istate
Refactor refresh_cache_entry() to work on a specific index, instead of
implicitly using the_index. This is in preparation for making the
make_cache_entry function apply to a specific index.

Signed-off-by: Jameson Miller <jamill@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03 10:58:15 -07:00
Junio C Hamano
42c8ce1c49 Merge branch 'bc/object-id'
Conversion from uchar[20] to struct object_id continues.

* bc/object-id: (42 commits)
  merge-one-file: compute empty blob object ID
  add--interactive: compute the empty tree value
  Update shell scripts to compute empty tree object ID
  sha1_file: only expose empty object constants through git_hash_algo
  dir: use the_hash_algo for empty blob object ID
  sequencer: use the_hash_algo for empty tree object ID
  cache-tree: use is_empty_tree_oid
  sha1_file: convert cached object code to struct object_id
  builtin/reset: convert use of EMPTY_TREE_SHA1_BIN
  builtin/receive-pack: convert one use of EMPTY_TREE_SHA1_HEX
  wt-status: convert two uses of EMPTY_TREE_SHA1_HEX
  submodule: convert several uses of EMPTY_TREE_SHA1_HEX
  sequencer: convert one use of EMPTY_TREE_SHA1_HEX
  merge: convert empty tree constant to the_hash_algo
  builtin/merge: switch tree functions to use object_id
  builtin/am: convert uses of EMPTY_TREE_SHA1_BIN to the_hash_algo
  sha1-file: add functions for hex empty tree and blob OIDs
  builtin/receive-pack: avoid hard-coded constants for push certs
  diff: specify abbreviation size in terms of the_hash_algo
  upload-pack: replace use of several hard-coded constants
  ...
2018-05-30 14:04:10 +09:00
Junio C Hamano
7913f53b56 Sync with Git 2.17.1
* maint: (25 commits)
  Git 2.17.1
  Git 2.16.4
  Git 2.15.2
  Git 2.14.4
  Git 2.13.7
  fsck: complain when .gitmodules is a symlink
  index-pack: check .gitmodules files with --strict
  unpack-objects: call fsck_finish() after fscking objects
  fsck: call fsck_finish() after fscking objects
  fsck: check .gitmodules content
  fsck: handle promisor objects in .gitmodules check
  fsck: detect gitmodules files
  fsck: actually fsck blob data
  fsck: simplify ".git" check
  index-pack: make fsck error message more specific
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  ...
2018-05-29 17:10:05 +09:00
Junio C Hamano
68f95b26e4 Sync with Git 2.16.4
* maint-2.16:
  Git 2.16.4
  Git 2.15.2
  Git 2.14.4
  Git 2.13.7
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  is_{hfs,ntfs}_dotgitmodules: add tests
  is_ntfs_dotgit: match other .git files
  is_hfs_dotgit: match other .git files
  is_ntfs_dotgit: use a size_t for traversing string
  submodule-config: verify submodule names as paths
2018-05-22 14:25:26 +09:00
Junio C Hamano
023020401d Sync with Git 2.15.2
* maint-2.15:
  Git 2.15.2
  Git 2.14.4
  Git 2.13.7
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  is_{hfs,ntfs}_dotgitmodules: add tests
  is_ntfs_dotgit: match other .git files
  is_hfs_dotgit: match other .git files
  is_ntfs_dotgit: use a size_t for traversing string
  submodule-config: verify submodule names as paths
2018-05-22 14:18:06 +09:00
Junio C Hamano
9e0f06d55d Sync with Git 2.14.4
* maint-2.14:
  Git 2.14.4
  Git 2.13.7
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  is_{hfs,ntfs}_dotgitmodules: add tests
  is_ntfs_dotgit: match other .git files
  is_hfs_dotgit: match other .git files
  is_ntfs_dotgit: use a size_t for traversing string
  submodule-config: verify submodule names as paths
2018-05-22 14:15:14 +09:00
Junio C Hamano
7b01c71b64 Sync with Git 2.13.7
* maint-2.13:
  Git 2.13.7
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  is_{hfs,ntfs}_dotgitmodules: add tests
  is_ntfs_dotgit: match other .git files
  is_hfs_dotgit: match other .git files
  is_ntfs_dotgit: use a size_t for traversing string
  submodule-config: verify submodule names as paths
2018-05-22 14:10:49 +09:00
Jeff King
10ecfa7649 verify_path: disallow symlinks in .gitmodules
There are a few reasons it's not a good idea to make
.gitmodules a symlink, including:

  1. It won't be portable to systems without symlinks.

  2. It may behave inconsistently, since Git may look at
     this file in the index or a tree without bothering to
     resolve any symbolic links. We don't do this _yet_, but
     the config infrastructure is there and it's planned for
     the future.

With some clever code, we could make (2) work. And some
people may not care about (1) if they only work on one
platform. But there are a few security reasons to simply
disallow it:

  a. A symlinked .gitmodules file may circumvent any fsck
     checks of the content.

  b. Git may read and write from the on-disk file without
     sanity checking the symlink target. So for example, if
     you link ".gitmodules" to "../oops" and run "git
     submodule add", we'll write to the file "oops" outside
     the repository.

Again, both of those are problems that _could_ be solved
with sufficient code, but given the complications in (1) and
(2), we're better off just outlawing it explicitly.

Note the slightly tricky call to verify_path() in
update-index's update_one(). There we may not have a mode if
we're not updating from the filesystem (e.g., we might just
be removing the file). Passing "0" as the mode there works
fine; since it's not a symlink, we'll just skip the extra
checks.

Signed-off-by: Jeff King <peff@peff.net>
2018-05-21 23:50:11 -04:00
Jeff King
641084b618 verify_dotfile: mention case-insensitivity in comment
We're more restrictive than we need to be in matching ".GIT"
on case-sensitive filesystems; let's make a note that this
is intentional.

Signed-off-by: Jeff King <peff@peff.net>
2018-05-21 23:50:11 -04:00
Jeff King
e19e5e66d6 verify_path: drop clever fallthrough
We check ".git" and ".." in the same switch statement, and
fall through the cases to share the end-of-component check.
While this saves us a line or two, it makes modifying the
function much harder. Let's just write it out.

Signed-off-by: Jeff King <peff@peff.net>
2018-05-21 23:50:11 -04:00
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
brian m. carlson
75691ea345 Update struct index_state to use struct object_id
Adjust struct index_state to use struct object_id instead of unsigned
char [20].

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-02 13:59:50 +09:00
brian m. carlson
2182abd94b split-index: convert struct split_index to object_id
Convert the base_sha1 member of struct split_index to use struct
object_id and rename it base_oid.  Include cache.h to make the structure
visible.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-02 13:59:50 +09:00
Nguyễn Thái Ngọc Duy
4c2db93807 read-cache.c: make $GIT_TEST_SPLIT_INDEX boolean
While at there, document about this special mode when running the test
suite.

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
Junio C Hamano
a5bbc29994 Merge branch 'bc/object-id'
Conversion from uchar[20] to struct object_id continues.

* bc/object-id: (36 commits)
  convert: convert to struct object_id
  sha1_file: introduce a constant for max header length
  Convert lookup_replace_object to struct object_id
  sha1_file: convert read_sha1_file to struct object_id
  sha1_file: convert read_object_with_reference to object_id
  tree-walk: convert tree entry functions to object_id
  streaming: convert istream internals to struct object_id
  tree-walk: convert get_tree_entry_follow_symlinks internals to object_id
  builtin/notes: convert static functions to object_id
  builtin/fmt-merge-msg: convert remaining code to object_id
  sha1_file: convert sha1_object_info* to object_id
  Convert remaining callers of sha1_object_info_extended to object_id
  packfile: convert unpack_entry to struct object_id
  sha1_file: convert retry_bad_packed_offset to struct object_id
  sha1_file: convert assert_sha1_type to object_id
  builtin/mktree: convert to struct object_id
  streaming: convert open_istream to use struct object_id
  sha1_file: convert check_sha1_signature to struct object_id
  sha1_file: convert read_loose_object to use struct object_id
  builtin/index-pack: convert struct ref_delta_entry to object_id
  ...
2018-04-10 08:25:45 +09:00
Junio C Hamano
3112c3fa7f Merge branch 'nd/shared-index-fix' into maint
Code clean-up.

* nd/shared-index-fix:
  read-cache: don't write index twice if we can't write shared index
  read-cache.c: move tempfile creation/cleanup out of write_shared_index
  read-cache.c: change type of "temp" in write_shared_index()
2018-03-22 14:24:16 -07:00
Junio C Hamano
b0e0fc267b Merge branch 'tg/split-index-fixes' into maint
The split-index mode had a few corner case bugs fixed.

* tg/split-index-fixes:
  travis: run tests with GIT_TEST_SPLIT_INDEX
  split-index: don't write cache tree with null oid entries
  read-cache: fix reading the shared index for other repos
2018-03-22 14:24:10 -07:00
Junio C Hamano
d17811154b Merge branch 'rj/warning-uninitialized-fix'
Compilation fix.

* rj/warning-uninitialized-fix:
  read-cache: fix an -Wmaybe-uninitialized warning
  -Wuninitialized: remove some 'init-self' workarounds
2018-03-21 11:30:15 -07:00
Junio C Hamano
fddf9a2d06 Merge branch 'bp/refresh-cache-ent-rehash-fix'
The codepath to replace an existing entry in the index had a bug in
updating the name hash structure, which has been fixed.

* bp/refresh-cache-ent-rehash-fix:
  Fix bugs preventing adding updated cache entries to the name hash
2018-03-21 11:30:11 -07:00
Junio C Hamano
beb2cdf504 Merge branch 'ma/skip-writing-unchanged-index'
Internal API clean-up to allow write_locked_index() optionally skip
writing the in-core index when it is not modified.

* ma/skip-writing-unchanged-index:
  write_locked_index(): add flag to avoid writing unchanged index
2018-03-21 11:30:10 -07:00
Ramsay Jones
00a4b03501 read-cache: fix an -Wmaybe-uninitialized warning
The function ce_write_entry() uses a 'self-initialised' variable
construct, for the symbol 'saved_namelen', to suppress a gcc
'-Wmaybe-uninitialized' warning, given that the warning is a false
positive.

For the purposes of this discussion, the ce_write_entry() function has
three code blocks of interest, that look like so:

        /* block #1 */
        if (ce->ce_flags & CE_STRIP_NAME) {
                saved_namelen = ce_namelen(ce);
                ce->ce_namelen = 0;
        }

        /* block #2 */
        /*
	 * several code blocks that contain, among others, calls
         * to copy_cache_entry_to_ondisk(ondisk, ce);
         */

        /* block #3 */
        if (ce->ce_flags & CE_STRIP_NAME) {
                ce->ce_namelen = saved_namelen;
                ce->ce_flags &= ~CE_STRIP_NAME;
        }

The warning implies that gcc thinks it is possible that the first
block is not entered, the calls to copy_cache_entry_to_ondisk()
could toggle the CE_STRIP_NAME flag on, thereby entering block #3
with saved_namelen unset. However, the copy_cache_entry_to_ondisk()
function does not write to ce->ce_flags (it only reads). gcc could
easily determine this, since that function is local to this file,
but it obviously doesn't.

In order to suppress this warning, we make it clear to the reader
(human and compiler), that block #3 will only be entered when the
first block has been entered, by introducing a new 'stripped_name'
boolean variable. We also take the opportunity to change the type
of 'saved_namelen' to 'unsigned int' to match ce->ce_namelen.

Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-20 09:59:21 -07:00
Ben Peart
0e267b7a24 Fix bugs preventing adding updated cache entries to the name hash
Update replace_index_entry() to clear the CE_HASHED flag from the new cache
entry so that it can add it to the name hash in set_index_entry()

Fix refresh_cache_ent() to use the copy_cache_entry() macro instead of memcpy()
so that it doesn't incorrectly copy the hash state from the old entry.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-15 10:58:30 -07:00
brian m. carlson
b4f5aca40e sha1_file: convert read_sha1_file to struct object_id
Convert read_sha1_file to take a pointer to struct object_id and rename
it read_object_file.  Do the same for read_sha1_file_extended.

Convert one use in grep.c to use the new function without any other code
change, since the pointer being passed is a void pointer that is already
initialized with a pointer to struct object_id.  Update the declaration
and definitions of the modified functions, and apply the following
semantic patch to convert the remaining callers:

@@
expression E1, E2, E3;
@@
- read_sha1_file(E1.hash, E2, E3)
+ read_object_file(&E1, E2, E3)

@@
expression E1, E2, E3;
@@
- read_sha1_file(E1->hash, E2, E3)
+ read_object_file(E1, E2, E3)

@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1.hash, E2, E3, E4)
+ read_object_file_extended(&E1, E2, E3, E4)

@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1->hash, E2, E3, E4)
+ read_object_file_extended(E1, E2, E3, E4)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-14 09:23:50 -07:00
Junio C Hamano
169c9c0169 Merge branch 'bw/c-plus-plus'
Avoid using identifiers that clash with C++ keywords.  Even though
it is not a goal to compile Git with C++ compilers, changes like
this help use of code analysis tools that targets C++ on our
codebase.

* bw/c-plus-plus: (37 commits)
  replace: rename 'new' variables
  trailer: rename 'template' variables
  tempfile: rename 'template' variables
  wrapper: rename 'template' variables
  environment: rename 'namespace' variables
  diff: rename 'template' variables
  environment: rename 'template' variables
  init-db: rename 'template' variables
  unpack-trees: rename 'new' variables
  trailer: rename 'new' variables
  submodule: rename 'new' variables
  split-index: rename 'new' variables
  remote: rename 'new' variables
  ref-filter: rename 'new' variables
  read-cache: rename 'new' variables
  line-log: rename 'new' variables
  imap-send: rename 'new' variables
  http: rename 'new' variables
  entry: rename 'new' variables
  diffcore-delta: rename 'new' variables
  ...
2018-03-06 14:54:07 -08:00