Derrick Stolee [Tue, 30 Mar 2021 13:10:58 +0000 (13:10 +0000)]
sparse-index: check index conversion happens
Add a test case that uses test_region to ensure that we are truly
expanding a sparse index to a full one, then converting back to sparse
when writing the index. As we integrate more Git commands with the
sparse index, we will convert these commands to check that we do _not_
convert the sparse index to a full index and instead stay sparse the
entire time.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:57 +0000 (13:10 +0000)]
unpack-trees: allow sparse directories
The index_pos_by_traverse_info() currently throws a BUG() when a
directory entry exists exactly in the index. We need to consider that it
is possible to have a directory in a sparse index as long as that entry
is itself marked with the skip-worktree bit.
The 'pos' variable is assigned a negative value if an exact match is not
found. Since a directory name can be an exact match, it is no longer an
error to have a nonnegative 'pos' value.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:56 +0000 (13:10 +0000)]
submodule: sparse-index should not collapse links
A submodule is stored as a "Git link" that actually points to a commit
within a submodule. Submodules are populated or not depending on
submodule configuration, not sparse-checkout. To ensure that the
sparse-index feature integrates correctly with submodules, we should not
collapse a directory if there is a Git link within its range.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:55 +0000 (13:10 +0000)]
sparse-index: convert from full to sparse
If we have a full index, then we can convert it to a sparse index by
replacing directories outside of the sparse cone with sparse directory
entries. The convert_to_sparse() method does this, when the situation is
appropriate.
For now, we avoid converting the index to a sparse index if:
1. the index is split.
2. the index is already sparse.
3. sparse-checkout is disabled.
4. sparse-checkout does not use cone mode.
Finally, we currently limit the conversion to when the
GIT_TEST_SPARSE_INDEX environment variable is enabled. A mode using Git
config will be added in a later change.
The trickiest thing about this conversion is that we might not be able
to mark a directory as a sparse directory just because it is outside the
sparse cone. There might be unmerged files within that directory, so we
need to look for those. Also, if there is some strange reason why a file
is not marked with CE_SKIP_WORKTREE, then we should give up on
converting that directory. There is still hope that some of its
subdirectories might be able to convert to sparse, so we keep looking
deeper.
The conversion process is assisted by the cache-tree extension. This is
calculated from the full index if it does not already exist. We then
abandon the cache-tree as it no longer applies to the newly-sparse
index. Thus, this cache-tree will be recalculated in every
sparse-full-sparse round-trip until we integrate the cache-tree
extension with the sparse index.
Some Git commands use the index after writing it. For example, 'git add'
will update the index, then write it to disk, then read its entries to
report information. To keep the in-memory index in a full state after
writing, we re-expand it to a full one after the write. This is wasteful
for commands that only write the index and do not read from it again,
but that is only the case until we make those commands "sparse aware."
We can compare the behavior of the sparse-index in
t1092-sparse-checkout-compability.sh by using GIT_TEST_SPARSE_INDEX=1
when operating on the 'sparse-index' repo. We can also compare the two
sparse repos directly, such as comparing their indexes (when expanded to
full in the case of the 'sparse-index' repo). We also verify that the
index is actually populated with sparse directory entries.
The 'checkout and reset (mixed)' test is marked for failure when
comparing a sparse repo to a full repo, but we can compare the two
sparse-checkout cases directly to ensure that we are not changing the
behavior when using a sparse index.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:54 +0000 (13:10 +0000)]
sparse-index: add 'sdir' index extension
The index format does not currently allow for sparse directory entries.
This violates some expectations that older versions of Git or
third-party tools might not understand. We need an indicator inside the
index file to warn these tools to not interact with a sparse index
unless they are aware of sparse directory entries.
Add a new _required_ index extension, 'sdir', that indicates that the
index may contain sparse directory entries. This allows us to continue
to use the differences in index formats 2, 3, and 4 before we create a
new index version 5 in a later change.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:53 +0000 (13:10 +0000)]
sparse-checkout: hold pattern list in index
As we modify the sparse-checkout definition, we perform index operations
on a pattern_list that only exists in-memory. This allows easy backing
out in case the index update fails.
However, if the index write itself cares about the sparse-checkout
pattern set, we need access to that in-memory copy. Place a pointer to
a 'struct pattern_list' in the index so we can access this on-demand.
This will be used in the next change which uses the sparse-checkout
definition to filter out directories that are outside the sparse cone.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:52 +0000 (13:10 +0000)]
unpack-trees: ensure full index
The next change will translate full indexes into sparse indexes at write
time. The existing logic provides a way for every sparse index to be
expanded to a full index at read time. However, there are cases where an
index is written and then continues to be used in-memory to perform
further updates.
unpack_trees() is frequently called after such a write. In particular,
commands like 'git reset' do this double-update of the index.
Ensure that we have a full index when entering unpack_trees(), but only
when command_requires_full_index is true. This is always true at the
moment, but we will later relax that after unpack_trees() is updated to
handle sparse directory entries.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:51 +0000 (13:10 +0000)]
test-tool: don't force full index
We will use 'test-tool read-cache --table' to check that a sparse
index is written as part of init_repos. Since we will no longer always
expand a sparse index into a full index, add an '--expand' parameter
that adds a call to ensure_full_index() so we can compare a sparse index
directly against a full index, or at least what the in-memory index
looks like when expanded in this way.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:50 +0000 (13:10 +0000)]
test-read-cache: print cache entries with --table
This table is helpful for discovering data in the index to ensure it is
being written correctly, especially as we build and test the
sparse-index. This table includes an output format similar to 'git
ls-tree', but should not be compared to that directly. The biggest
reasons are that 'git ls-tree' includes a tree entry for every
subdirectory, even those that would not appear as a sparse directory in
a sparse-index. Further, 'git ls-tree' does not use a trailing directory
separator for its tree rows.
This does not print the stat() information for the blobs. That will be
added in a future change with another option. The tests that are added
in the next few changes care only about the object types and IDs.
However, this future need for full index information justifies the need
for this test helper over extending a user-facing feature, such as 'git
ls-files'.
To make the option parsing slightly more robust, wrap the string
comparisons in a loop adapted from test-dir-iterator.c.
Care must be taken with the final check for the 'cnt' variable. We
continue the expectation that the numerical value is the final argument.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:49 +0000 (13:10 +0000)]
t1092: compare sparse-checkout to sparse-index
Add a new 'sparse-index' repo alongside the 'full-checkout' and
'sparse-checkout' repos in t1092-sparse-checkout-compatibility.sh. Also
add run_on_sparse and test_sparse_match helpers. These helpers will be
used when the sparse index is implemented.
Add the GIT_TEST_SPARSE_INDEX environment variable to enable the
sparse-index by default. This can be enabled across all tests, but that
will only affect cases where the sparse-checkout feature is enabled.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:48 +0000 (13:10 +0000)]
sparse-index: implement ensure_full_index()
We will mark an in-memory index_state as having sparse directory entries
with the sparse_index bit. These currently cannot exist, but we will add
a mechanism for collapsing a full index to a sparse one in a later
change. That will happen at write time, so we must first allow parsing
the format before writing it.
Commands or methods that require a full index in order to operate can
call ensure_full_index() to expand that index in-memory. This requires
parsing trees using that index's repository.
Sparse directory entries have a specific 'ce_mode' value. The macro
S_ISSPARSEDIR(ce->ce_mode) can check if a cache_entry 'ce' has this type.
This ce_mode is not possible with the existing index formats, so we don't
also verify all properties of a sparse-directory entry, which are:
1. ce->ce_mode == 0040000
2. ce->flags & CE_SKIP_WORKTREE is true
3. ce->name[ce->namelen - 1] == '/' (ends in dir separator)
4. ce->oid references a tree object.
These are all semi-enforced in ensure_full_index() to some extent. Any
deviation will cause a warning at minimum or a failure in the worst
case.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:47 +0000 (13:10 +0000)]
sparse-index: add guard to ensure full index
Upcoming changes will introduce modifications to the index format that
allow sparse directories. It will be useful to have a mechanism for
converting those sparse index files into full indexes by walking the
tree at those sparse directories. Name this method ensure_full_index()
as it will guarantee that the index is fully expanded.
This method is not implemented yet, and instead we focus on the
scaffolding to declare it and call it at the appropriate time.
Add a 'command_requires_full_index' member to struct repo_settings. This
will be an indicator that we need the index in full mode to do certain
index operations. This starts as being true for every command, then we
will set it to false as some commands integrate with sparse indexes.
If 'command_requires_full_index' is true, then we will immediately
expand a sparse index to a full one upon reading from disk. This
suffices for now, but we will want to add more callers to
ensure_full_index() later.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:46 +0000 (13:10 +0000)]
t1092: clean up script quoting
This test was introduced in 19a0acc83e4 (t1092: test interesting
sparse-checkout scenarios, 2021-01-23), but it contains issues with quoting
that were not noticed until starting this follow-up series. The old
mechanism would drop quoting such as in
test_all_match git commit -m "touch README.md"
The above happened to work because README.md is a file in the
repository, so 'git commit -m touch REAMDE.md' would succeed by
accident.
Other cases included quoting for no good reason, so clean that up now.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:45 +0000 (13:10 +0000)]
t/perf: add performance test for sparse operations
Create a test script that takes the default performance test (the Git
codebase) and multiplies it by 256 using four layers of duplicated
trees of width four. This results in nearly one million blob entries in
the index. Then, we can clone this repository with sparse-checkout
patterns that demonstrate four copies of the initial repository. Each
clone will use a different index format or mode so peformance can be
tested across the different options.
Note that the initial repo is stripped of submodules before doing the
copies. This preserves the expected data shape of the sparse index,
because directories containing submodules are not collapsed to a sparse
directory entry.
Run a few Git commands on these clones, especially those that use the
index (status, add, commit).
Here are the results on my Linux machine:
Test
--------------------------------------------------------------
2000.2: git status (full-index-v3) 0.37(0.30+0.09)
2000.3: git status (full-index-v4) 0.39(0.32+0.10)
2000.4: git add -A (full-index-v3) 1.42(1.06+0.20)
2000.5: git add -A (full-index-v4) 1.26(0.98+0.16)
2000.6: git add . (full-index-v3) 1.40(1.04+0.18)
2000.7: git add . (full-index-v4) 1.26(0.98+0.17)
2000.8: git commit -a -m A (full-index-v3) 1.42(1.11+0.16)
2000.9: git commit -a -m A (full-index-v4) 1.33(1.08+0.16)
It is perhaps noteworthy that there is an improvement when using index
version 4. This is because the v3 index uses 108 MiB while the v4
index uses 80 MiB. Since the repeated portions of the directories are
very short (f3/f1/f2, for example) this ratio is less pronounced than in
similarly-sized real repositories.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 30 Mar 2021 13:10:44 +0000 (13:10 +0000)]
sparse-index: design doc and format update
This begins a long effort to update the index format to allow sparse
directory entries. This should result in a significant improvement to
Git commands when HEAD contains millions of files, but the user has
selected many fewer files to keep in their sparse-checkout definition.
Currently, the index format is only updated in the presence of
extensions.sparseIndex instead of increasing a file format version
number. This is temporary, and index v5 is part of the plan for future
work in this area.
The design document details many of the reasons for embarking on this
work, and also the plan for completing it safely.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Simplify the signature of read_tree_recursive() to omit the "base",
"baselen" and "stage" arguments. No callers of it use these parameters
for anything anymore.
The last function to call read_tree_recursive() with a non-"" path was
read_tree_recursive() itself, but that was changed in ffd31f661d5 (Reimplement read_tree_recursive() using
tree_entry_interesting(), 2011-03-25).
The last user of the "stage" parameter went away in the last commit,
and even that use was mere boilerplate.
So let's remove those and rename the read_tree_recursive() function to
just read_tree(). We had another read_tree() function that I've
refactored away in preceding commits, since all in-tree users read
trees recursively with a callback we can change the name to signify
that this is the norm.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
tree.h API: expose read_tree_1() as read_tree_at()
Rename the static read_tree_1() function to read_tree_at(). This
function works just like read_tree_recursive(), except you provide
your own strbuf.
This step doesn't make much sense now, but in follow-up commits I'll
remove the base/baselen/stage arguments to read_tree_recursive(). At
that point an anticipated in-tree user[1] for the old
read_tree_recursive() couldn't provide a path to start the
traversal.
Let's give them a function to do so with an API that makes more sense
for them, by taking a strbuf we should be able to avoid more casting
and/or reallocations in the future.
archive: stop passing "stage" through read_tree_recursive()
The "stage" variable being passed around in the archive code has only
ever been an elaborate way to hardcode the value "0".
This code was added in its original form in e4fbbfe9ecc (Add
git-zip-tree, 2006-08-26), at which point a hardcoded "0" would be
passed down through read_tree_recursive() to write_zip_entry().
It was then diligently added to the "struct directory" in ed22b4173bd (archive: support filtering paths with glob, 2014-09-21),
but we were still not doing anything except passing it around as-is.
Let's stop doing that in the code internal to archive.c, we'll still
feed "0" to read_tree_recursive() itself, but won't use it. That we're
providing it at all to read_tree_recursive() will be changed in a
follow-up commit.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactor away the read_tree() function into its only user,
overlay_tree_on_index().
First, change read_one_entry_opt() to use the strbuf parameter
read_tree_recursive() passes down in place. This finishes up a partial
refactoring started in 6a0b0b6de99 (tree.c: update read_tree_recursive
callback to pass strbuf as base, 2014-11-30).
Moving the rest into overlay_tree_on_index() makes this index juggling
we're doing easier to read.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
ls-files: don't needlessly pass around stage variable
Now that read_tree() has been moved to ls-files.c we can get rid of
the stage != 1 case that'll never happen.
Let's not use read_tree_recursive() as a pass-through to pass "stage =
1" either. For now we'll pass an unused "stage = 0" for consistency
with other read_tree_recursive() callers, that argument will be
removed in a follow-up commit.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
tree.c API: move read_tree() into builtin/ls-files.c
Since the read_tree() API was added around the same time as
read_tree_recursive() in 94537c78a82 (Move "read_tree()" to
"tree.c"[...], 2005-04-22) and b12ec373b8e ([PATCH] Teach read-tree
about commit objects, 2005-04-20) things have gradually migrated over
to the read_tree_recursive() version.
Now builtin/ls-files.c is the last user of this code, let's move all
the relevant code there. This allows for subsequent simplification of
it, and an eventual move to read_tree_recursive().
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add tests for "ls-files --with-tree". There was effectively no
coverage for any normal usage of this command, only the tests added in 54e1abce90e (Add test case for ls-files --with-tree, 2007-10-03) for
an obscure bug.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add missing tests for showing a tree with "git show". Let's test for
showing a tree, two trees, and that doing so doesn't recurse.
The only tests for this code added in 5d7eeee2ac6 (git-show: grok
blobs, trees and tags, too, 2006-12-14) were the tests in
t7701-repack-unpack-unreachable.sh added in ccc1297226b (repack:
modify behavior of -A option to leave unreferenced objects unpacked,
2008-05-09).
Let's add this common mode of operation to the "show" tests
themselves. It's more obvious, and the tests in
t7701-repack-unpack-unreachable.sh happily pass if we start buggily
emitting trees recursively.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Thu, 4 Mar 2021 22:51:32 +0000 (22:51 +0000)]
Documentation/RelNotes: improve release note for rename detection work
There were some early changes in the 2.31 cycle to optimize some setup
in diffcore-rename.c[1], some later changes to measure performance[2],
and finally some significant changes to improve rename detection
performance. The final one was merged with the note
Performance optimization work on the rename detection continues.
That works for the commit log, but feels misleading as a release note
since all the changes were within one cycle. Simplify this to just
Performance improvements for rename detection.
The former wording could be seen as hinting that more performance
improvements will come in 2.32, which is true, but we can just cover
those in the 2.32 release notes when the time comes.
This commit causes breakage on macOS (10.13). It causes errors on
startup and completely breaks the commit functionality. There are two
main problems. First, it uses `string cat` which is not supported on
older Tcl versions. Second, it does a half close of the bidirectional
pipe to git-stripspace which is also not supported on older Tcl
versions.
Reported-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>
Junio C Hamano [Mon, 1 Mar 2021 22:02:57 +0000 (14:02 -0800)]
Merge branch 'hv/trailer-formatting'
The logic to handle "trailer" related placeholders in the
"--format=" mechanisms in the "log" family and "for-each-ref"
family is getting unified.
* hv/trailer-formatting:
ref-filter: use pretty.c logic for trailers
pretty.c: capture invalid trailer argument
pretty.c: refactor trailer logic to `format_set_trailers_options()`
t6300: use function to test trailer options
Junio C Hamano [Mon, 1 Mar 2021 22:02:57 +0000 (14:02 -0800)]
Merge branch 'sv/t7001-modernize'
Test script modernization.
* sv/t7001-modernize:
t7001: use `test` rather than `[`
t7001: use here-docs instead of echo
t7001: put each command on a separate line
t7001: use '>' rather than 'touch'
t7001: avoid using `cd` outside of subshells
t7001: remove whitespace after redirect operators
t7001: modernize subshell formatting
t7001: remove unnecessary blank lines
t7001: indent with TABs instead of spaces
t7001: modernize test formatting
Junio C Hamano [Mon, 1 Mar 2021 22:02:57 +0000 (14:02 -0800)]
Merge branch 'jt/transfer-fsck-across-packs'
The approach to "fsck" the incoming objects in "index-pack" is
attractive for performance reasons (we have them already in core,
inflated and ready to be inspected), but fundamentally cannot be
applied fully when we receive more than one pack stream, as a tree
object in one pack may refer to a blob object in another pack as
".gitmodules", when we want to inspect blobs that are used as
".gitmodules" file, for example. Teach "index-pack" to emit
objects that must be inspected later and check them in the calling
"fetch-pack" process.
* jt/transfer-fsck-across-packs:
fetch-pack: print and use dangling .gitmodules
fetch-pack: with packfile URIs, use index-pack arg
http-fetch: allow custom index-pack args
http: allow custom index-pack args
Junio C Hamano [Mon, 1 Mar 2021 22:02:57 +0000 (14:02 -0800)]
Merge branch 'ds/chunked-file-api'
The common code to deal with "chunked file format" that is shared
by the multi-pack-index and commit-graph files have been factored
out, to help codepaths for both filetypes to become more robust.
* ds/chunked-file-api:
commit-graph.c: display correct number of chunks when writing
chunk-format: add technical docs
chunk-format: restore duplicate chunk checks
midx: use 64-bit multiplication for chunk sizes
midx: use chunk-format read API
commit-graph: use chunk-format read API
chunk-format: create read chunk API
midx: use chunk-format API in write_midx_internal()
midx: drop chunk progress during write
midx: return success/failure in chunk write methods
midx: add num_large_offsets to write_midx_context
midx: add pack_perm to write_midx_context
midx: add entries to write_midx_context
midx: use context in write_midx_pack_names()
midx: rename pack_info to write_midx_context
commit-graph: use chunk-format write API
chunk-format: create chunk format write API
commit-graph: anonymize data in chunk_write_fn
Junio C Hamano [Mon, 1 Mar 2021 22:02:56 +0000 (14:02 -0800)]
Merge branch 'en/diffcore-rename'
Performance optimization work on the rename detection continues.
* en/diffcore-rename:
merge-ort: call diffcore_rename() directly
gitdiffcore doc: mention new preliminary step for rename detection
diffcore-rename: guide inexact rename detection based on basenames
diffcore-rename: complete find_basename_matches()
diffcore-rename: compute basenames of source and dest candidates
t4001: add a test comparing basename similarity and content similarity
diffcore-rename: filter rename_src list when possible
diffcore-rename: no point trying to find a match better than exact
Junio C Hamano [Mon, 1 Mar 2021 22:02:56 +0000 (14:02 -0800)]
Merge branch 'jh/fsmonitor-prework'
Preliminary changes to fsmonitor integration.
* jh/fsmonitor-prework:
fsmonitor: refactor initialization of fsmonitor_last_update token
fsmonitor: allow all entries for a folder to be invalidated
fsmonitor: log FSMN token when reading and writing the index
fsmonitor: log invocation of FSMonitor hook to trace2
read-cache: log the number of scanned files to trace2
read-cache: log the number of lstat calls to trace2
preload-index: log the number of lstat calls to trace2
p7519: add trace logging during perf test
p7519: move watchman cleanup earlier in the test
p7519: fix watchman watch-list test on Windows
p7519: do not rely on "xargs -d" in test
Junio C Hamano [Mon, 1 Mar 2021 17:19:37 +0000 (09:19 -0800)]
Revert "commit-graph: when incompatible with graphs, indicate why"
This reverts commit c85eec7fc37e1ca79072f263ae6ea1ee305ba38c, as
it is a bit overzealous, we are in prerelease freeze, and we want
to have enough time to get this right and cook in 'next'.
Jeff King [Mon, 1 Mar 2021 09:29:47 +0000 (04:29 -0500)]
config.mak.uname: enable OPEN_RETURNS_EINTR for macOS Big Sur
We've had mixed reports on whether the latest release of macOS needs
this Makefile knob set. In most reported cases, there's antivirus
software running (which one might imagine could cause an open() call to
be delayed). However, one of the (off-list) reports I've gotten
indicated that it happened on an otherwise clean install of Big Sur.
Since the symptom is so bad (checkout randomly fails to write several
fails when the progress meter kicks in), and since the workaround is so
lightweight (if we don't see EINTR, it's just an extra conditional
check), let's just turn it on by default.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Fri, 26 Feb 2021 06:14:35 +0000 (01:14 -0500)]
Makefile: add OPEN_RETURNS_EINTR knob
On some platforms, open() reportedly returns EINTR when opening regular
files and we receive a signal (usually SIGALRM from our progress meter).
This shouldn't happen, as open() should be a restartable syscall, and we
specify SA_RESTART when setting up the alarm handler. So it may actually
be a kernel or libc bug for this to happen. But it has been reported on
at least one version of Linux (on a network filesystem):
as well as on macOS starting with Big Sur even on a regular filesystem.
We can work around it by retrying open() calls that get EINTR, just as
we do for read(), etc. Since we don't ever _want_ to interrupt an open()
call, we can get away with just redefining open, rather than insisting
all callsites use xopen().
We actually do have an xopen() wrapper already (and it even does this
retry, though there's no indication of it being an observed problem back
then; it seems simply to have been lifted from xread(), etc). But it is
used hardly anywhere, and isn't suitable for general use because it will
die() on error. In theory we could combine the two, but it's awkward to
do so because of the variable-args interface of open().
This patch adds a Makefile knob for enabling the workaround. It's not
enabled by default for any platforms in config.mak.uname yet, as we
don't have enough data to decide how common this is (I have not been
able to reproduce on either Linux or Big Sur myself). It may be worth
enabling preemptively anyway, since the cost is pretty low (if we don't
see an EINTR, it's just an extra conditional).
However, note that we must not enable this on Windows. It doesn't do
anything there, and the macro overrides the existing mingw_open()
redirection. I've added a preemptive #undef here in the mingw header
(which is processed first) to just quietly disable it (we could also
make it an #error, but there is little point in being so aggressive).
Reported-by: Aleksey Kliger <alklig@microsoft.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Fri, 26 Feb 2021 00:43:32 +0000 (16:43 -0800)]
Merge branch 'dl/doc-config-camelcase'
A handful of multi-word configuration variable names in
documentation that are spelled in all lowercase have been corrected
to use the more canonical camelCase.
* dl/doc-config-camelcase:
index-format doc: camelCase core.excludesFile
blame-options.txt: camelcase blame.blankBoundary
i18n.txt: camel case and monospace "i18n.commitEncoding"
Junio C Hamano [Fri, 26 Feb 2021 00:43:31 +0000 (16:43 -0800)]
Merge branch 'mt/add-chmod-fixes'
Various fixes on "git add --chmod".
* mt/add-chmod-fixes:
add: propagate --chmod errors to exit status
add: mark --chmod error string for translation
add --chmod: don't update index when --dry-run is used
Junio C Hamano [Fri, 26 Feb 2021 00:43:31 +0000 (16:43 -0800)]
Merge branch 'ds/merge-base-independent'
The code to implement "git merge-base --independent" was poorly
done and was kept from the very beginning of the feature.
* ds/merge-base-independent:
commit-reach: stale commits may prune generation further
commit-reach: use heuristic in remove_redundant()
commit-reach: move compare_commits_by_gen
commit-reach: use one walk in remove_redundant()
commit-reach: reduce requirements for remove_redundant()
Junio C Hamano [Fri, 26 Feb 2021 00:43:30 +0000 (16:43 -0800)]
Merge branch 'mt/checkout-index-corner-cases'
The error codepath around the "--temp/--prefix" feature of "git
checkout-index" has been improved.
* mt/checkout-index-corner-cases:
checkout-index: omit entries with no tempname from --temp output
write_entry(): fix misuses of `path` in error messages
Junio C Hamano [Fri, 26 Feb 2021 00:43:29 +0000 (16:43 -0800)]
Merge branch 'mz/doc-notes-are-not-anchors'
Objects that lost references can be pruned away, even when they
have notes attached to it (and these notes will become dangling,
which in turn can be pruned with "git notes prune"). This has been
clarified in the documentation.
* mz/doc-notes-are-not-anchors:
docs: clarify that refs/notes/ do not keep the attached objects alive
Junio C Hamano [Fri, 26 Feb 2021 00:43:29 +0000 (16:43 -0800)]
Merge branch 'ab/detox-gettext-tests'
Removal of GIT_TEST_GETTEXT_POISON continues.
* ab/detox-gettext-tests:
tests: remove most uses of test_i18ncmp
tests: remove last uses of C_LOCALE_OUTPUT
tests: remove most uses of C_LOCALE_OUTPUT
tests: remove last uses of GIT_TEST_GETTEXT_POISON=false
* jk/rev-list-disk-usage:
docs/rev-list: add some examples of --disk-usage
docs/rev-list: add an examples section
rev-list: add --disk-usage option for calculating disk usage
t: add --no-tag option to test_commit
Denton Liu [Wed, 24 Feb 2021 20:26:39 +0000 (12:26 -0800)]
i18n.txt: camel case and monospace "i18n.commitEncoding"
In 95791be750 (doc: camelCase the i18n config variables to improve
readability, 2017-07-17), the other i18n config variables were
camel cased. However, this one instance was missed.
Camel case and monospace "i18n.commitEncoding" so that it matches the
surrounding text.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
[jc: fixed 3 other mistakes that are exactly the same] Signed-off-by: Junio C Hamano <gitster@pobox.com>
Neeraj Singh [Thu, 18 Feb 2021 02:48:26 +0000 (02:48 +0000)]
read-cache: make the index write buffer size 128K
Writing an index 8K at a time invokes the OS filesystem and caching code
very frequently, introducing noticeable overhead while writing large
indexes. When experimenting with different write buffer sizes on Windows
writing the Windows OS repo index (260MB), most of the benefit came by
bumping the index write buffer size to 64K. I picked 128K to ensure that
we're past the knee of the curve.
With this change, the time under do_write_index for an index with 3M
files goes from ~1.02s to ~0.72s.
Signed-off-by: Neeraj Singh <neerajsi@ntdev.microsoft.com> Acked-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Matheus Tavares [Tue, 23 Feb 2021 01:10:35 +0000 (22:10 -0300)]
add: propagate --chmod errors to exit status
If `add` encounters an error while applying the --chmod changes, it
prints a message to stderr, but exits with a success code. This might
have been an oversight, as the command does exit with a non-zero code in
other situations where it cannot (or refuses to) update all of the
requested paths (e.g. when some of the given paths are ignored). So make
the exit behavior more consistent by also propagating --chmod errors to
the exit status.
Note: the test "all statuses changed in folder if . is given" uses paths
added by previous test cases, some of which might be symbolic links.
Because `git add --chmod` will now fail with such paths, this test would
depend on whether all the previous tests were executed, or only some
of them. Avoid that by running the test on a fresh repo with only
regular files.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Matheus Tavares [Tue, 23 Feb 2021 01:10:34 +0000 (22:10 -0300)]
add: mark --chmod error string for translation
This error message is intended for humans, so mark it for translation.
Also use error() instead of fprintf(stderr, ...), to make the
corresponding line a bit cleaner, and to display the "error:" prefix,
which helps classifying the nature/severity of the message.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Matheus Tavares [Tue, 23 Feb 2021 01:10:33 +0000 (22:10 -0300)]
add --chmod: don't update index when --dry-run is used
`git add --chmod` applies the mode changes even when `--dry-run` is
used. Fix that and add some tests for this option combination.
Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff Hostetler [Wed, 24 Feb 2021 14:31:57 +0000 (14:31 +0000)]
dir: fix malloc of root untracked_cache_dir
Use FLEX_ALLOC_STR() to allocate the `struct untracked_cache_dir`
for the root directory. Get rid of unsafe code that might fail to
initialize the `name` field (if FLEX_ARRAY is not 1). This will
make it clear that we intend to have a structure with an empty
string following it.
A problem was observed on Windows where the length of the memset() was
too short, so the first byte of the name field was not zeroed. This
resulted in the name field having garbage from a previous use of that
area of memory.
The record for the root directory was then written to the untracked-cache
extension in the index. This garbage would then be visible to future
commands when they reloaded the untracked-cache extension.
Since the directory record for the root directory had garbage in the
`name` field, the `t/helper/test-tool dump-untracked-cache` tool
printed this garbage as the path prefix (rather than '/') for each
directory in the untracked cache as it recursed.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Wed, 24 Feb 2021 17:12:22 +0000 (12:12 -0500)]
commit-graph.c: display correct number of chunks when writing
When writing a commit-graph, a progress meter is shown which indicates
the number of pieces of data to write (one per commit in each chunk).
In 47410aa837 (commit-graph: use chunk-format write API, 2021-02-18),
the number of chunks became tracked by the new chunk-format API. But a
stray local variable was left behind from when write_commit_graph_file()
used to keep track of the same.
Since this was no longer updated after 47410aa837, the progress meter
appeared broken:
$ git commit-graph write --reachable
Expanding reachable commits in commit graph: 837569, done.
Writing out commit graph in 3 passes: 166% (4187845/2512707), done.
Drop the local variable and rely instead on the chunk-format API to tell
us the correct number of chunks.
Reported-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Acked-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 23 Feb 2021 23:13:32 +0000 (15:13 -0800)]
push: do not turn --delete '' into a matching push
When we added a syntax sugar "git push remote --delete <ref>" to
"git push" as a synonym to the canonical "git push remote :<ref>"
syntax at f517f1f2 (builtin-push: add --delete as syntactic sugar
for :foo, 2009-12-30), we weren't careful enough to make sure that
<ref> is not empty.
Blindly rewriting "--delete <ref>" to ":<ref>" means that an empty
string <ref> results in refspec ":", which is the syntax to ask for
"matching" push that does not delete anything.
Worse yet, if there were matching refs that can be fast-forwarded,
they would have been published prematurely, even if the user feels
that they are not ready yet to be pushed out, which would be a real
disaster.
Noticed-by: Tilman Vogel <tilman.vogel@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Tue, 23 Feb 2021 20:50:58 +0000 (15:50 -0500)]
doc: mention approxidates for git-commit --date
We describe the more strict date formats accepted by GIT_COMMITTER_DATE,
etc, but the --date option also allows the looser approxidate formats,
as well. Unfortunately we don't have a good or complete reference for
this format, but let's at least mention that it _is_ looser, and give a
few examples.
If we ever write separate, more complete date-format documentation, we
should refer to it from here.
Based-on-a-patch-by: Utku Gultopu <ugultopu@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
This adds yet another vimdiff/gvimdiff variant and presents conflicts as
a two-way diff between 'LOCAL' and 'REMOTE'. 'MERGED' is not opened
which deviates from the norm so usage text is echoed as a Vim message on
startup that instructs the user with how to proceed and how to abort.
Vimdiff is well-suited to two-way diffs so this is an option for a more
simple, more streamlined conflict resolution. For example: it is
difficult to communicate differences across more than two files using
only syntax highlighting; default vimdiff commands to get and put
changes between buffers do not need the user to manually specify
a source or destination buffer when only using two buffers.
Like other merge tools that directly compare 'LOCAL' with 'REMOTE', this
tool will benefit when paired with the new `mergetool.hideResolved`
setting.
Signed-off-by: Seth House <seth@eseth.com> Tested-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Han-Wen Nienhuys [Tue, 23 Feb 2021 16:57:23 +0000 (16:57 +0000)]
doc/reftable: document how to handle windows
On Windows we can't delete or overwrite files opened by other processes. Here we
sketch how to handle this situation.
We propose to use a random element in the filename. It's possible to design an
alternate solution based on counters, but that would assign semantics to the
filenames that complicates implementation.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Eric Sunshine [Tue, 23 Feb 2021 07:31:07 +0000 (02:31 -0500)]
maintenance: fix incorrect `maintenance.repo` path with bare repository
The periodic maintenance tasks configured by `git maintenance start`
invoke `git for-each-repo` to run `git maintenance run` on each path
specified by the multi-value global configuration variable
`maintenance.repo`. Because `git for-each-repo` will likely be run
outside of the repositories which require periodic maintenance, it is
mandatory that the repository paths specified by `maintenance.repo` are
absolute.
Unfortunately, however, `git maintenance register` does nothing to
ensure that the paths it assigns to `maintenance.repo` are indeed
absolute, and may in fact -- especially in the case of a bare repository
-- assign a relative path to `maintenance.repo` instead. Fix this
problem by converting all paths to absolute before assigning them to
`maintenance.repo`.
While at it, also fix `git maintenance unregister` to convert paths to
absolute, as well, in order to ensure that it can correctly remove from
`maintenance.repo` a path assigned via `git maintenance register`.
Reported-by: Clement Moyroud <clement.moyroud@gmail.com> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 23 Feb 2021 00:12:43 +0000 (16:12 -0800)]
Merge branch 'ab/test-lib'
Test framework clean-up.
* ab/test-lib:
test-lib-functions: assert correct parameter count
test-lib-functions: remove bug-inducing "diagnostics" helper param
test libs: rename "diff-lib" to "lib-diff"
t/.gitattributes: sort lines
test-lib-functions: move function to lib-bitmap.sh
test libs: rename gitweb-lib.sh to lib-gitweb.sh
test libs: rename bundle helper to "lib-bundle.sh"
test-lib-functions: remove generate_zero_bytes() wrapper
test-lib-functions: move test_set_index_version() to its user
test lib: change "error" to "BUG" as appropriate
test-lib: remove check_var_migration
Junio C Hamano [Tue, 23 Feb 2021 00:12:43 +0000 (16:12 -0800)]
Merge branch 'ab/pager-exit-log'
When a pager spawned by us exited, the trace log did not record its
exit status correctly, which has been corrected.
* ab/pager-exit-log:
pager: properly log pager exit code when signalled
run-command: add braces for "if" block in wait_or_whine()
pager: test for exit code with and without SIGPIPE
pager: refactor wait_for_pager() function
Junio C Hamano [Tue, 23 Feb 2021 00:12:42 +0000 (16:12 -0800)]
Merge branch 'bc/signed-objects-with-both-hashes'
Signed commits and tags now allow verification of objects, whose
two object names (one in SHA-1, the other in SHA-256) are both
signed.
* bc/signed-objects-with-both-hashes:
gpg-interface: remove other signature headers before verifying
ref-filter: hoist signature parsing
commit: allow parsing arbitrary buffers with headers
gpg-interface: improve interface for parsing tags
commit: ignore additional signatures when parsing signed commits
ref-filter: switch some uses of unsigned long to size_t
Junio C Hamano [Tue, 23 Feb 2021 00:12:42 +0000 (16:12 -0800)]
Merge branch 'dl/stash-cleanup'
Documentation, code and test clean-up around "git stash".
* dl/stash-cleanup:
stash: declare ref_stash as an array
t3905: use test_cmp() to check file contents
t3905: replace test -s with test_file_not_empty
t3905: remove nested git in command substitution
t3905: move all commands into test cases
t3905: remove spaces after redirect operators
git-stash.txt: be explicit about subcommand options
Andrzej Hunt [Fri, 19 Feb 2021 20:13:10 +0000 (20:13 +0000)]
commit-graph: avoid leaking topo_levels slab in write_commit_graph()
write_commit_graph initialises topo_levels using init_topo_level_slab(),
next it calls compute_topological_levels() which can cause the slab to
grow, we therefore need to clear the slab again using
clear_topo_level_slab() when we're done.
First introduced in 72a2bfca (commit-graph: add a slab to store
topological levels, 2021-01-16).
Direct leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x498ae9 in realloc /src/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xafbed8 in xrealloc /src/git/wrapper.c:126:8
#2 0x7966d1 in topo_level_slab_at_peek /src/git/commit-graph.c:71:1
#3 0x7965e0 in topo_level_slab_at /src/git/commit-graph.c:71:1
#4 0x78fbf5 in compute_topological_levels /src/git/commit-graph.c:1472:12
#5 0x78c5c3 in write_commit_graph /src/git/commit-graph.c:2456:2
#6 0x535c5f in graph_write /src/git/builtin/commit-graph.c:299:6
#7 0x5350ca in cmd_commit_graph /src/git/builtin/commit-graph.c:337:11
#8 0x4cddb1 in run_builtin /src/git/git.c:453:11
#9 0x4cabe2 in handle_builtin /src/git/git.c:704:3
#10 0x4cd084 in run_argv /src/git/git.c:771:4
#11 0x4ca424 in cmd_main /src/git/git.c:902:19
#12 0x707fb6 in main /src/git/common-main.c:52:11
#13 0x7fee4249383f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f)
Indirect leak of 524256 byte(s) in 1 object(s) allocated from:
#0 0x498942 in calloc /src/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
#1 0xafc088 in xcalloc /src/git/wrapper.c:140:8
#2 0x796870 in topo_level_slab_at_peek /src/git/commit-graph.c:71:1
#3 0x7965e0 in topo_level_slab_at /src/git/commit-graph.c:71:1
#4 0x78fbf5 in compute_topological_levels /src/git/commit-graph.c:1472:12
#5 0x78c5c3 in write_commit_graph /src/git/commit-graph.c:2456:2
#6 0x535c5f in graph_write /src/git/builtin/commit-graph.c:299:6
#7 0x5350ca in cmd_commit_graph /src/git/builtin/commit-graph.c:337:11
#8 0x4cddb1 in run_builtin /src/git/git.c:453:11
#9 0x4cabe2 in handle_builtin /src/git/git.c:704:3
#10 0x4cd084 in run_argv /src/git/git.c:771:4
#11 0x4ca424 in cmd_main /src/git/git.c:902:19
#12 0x707fb6 in main /src/git/common-main.c:52:11
#13 0x7fee4249383f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f)
SUMMARY: AddressSanitizer: 524264 byte(s) leaked in 2 allocation(s).
Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
ZheNing Hu [Fri, 19 Feb 2021 12:53:54 +0000 (12:53 +0000)]
difftool.c: learn a new way start at specified file
`git difftool` only allow us to select file to view in turn.
If there is a commit with many files and we exit in the middle,
we will have to traverse list again to get the file diff which
we want to see. Therefore,teach the command an option
`--skip-to=<path>` to allow the user to say that diffs for earlier
paths are not interesting (because they were already seen in an
earlier session) and start this session with the named path.
Signed-off-by: ZheNing Hu <adlternative@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Fri, 19 Feb 2021 12:34:10 +0000 (12:34 +0000)]
commit-reach: stale commits may prune generation further
The remove_redundant_with_gen() algorithm performs a depth-first-search
to find commits in the 'array' list, starting at the parents of each
commit in 'array'. The result is that commits in 'array' are marked
STALE when they are reachable from another commit in 'array'.
This depth-first-search is fast when commits lie on or near the
first-parent history of the higher commits. The search terminates early
if all but one commit becomes marked STALE.
However, it is possible that there are two independent commits with high
generation number. In that case, the depth-first-search might languish
by searching in lower generations due to the fixed min_generation used
throughout the method.
With the expectation that commits with lower generation are expected to
become STALE more often, we can optimize further by increasing that
min_generation boundary upon discovery of the commit with minimum
generation.
We must first sort the commits in 'array' by generation. We cannot sort
'array' itself since it must preserve relative order among the returned
results (see revision.c:mark_redundant_parents() for an example).
This simplifies the initialization of min_generation, but it also allows
us to increase the new min_generation when we find the commit with
smallest generation remaining.
This requires more than two commits in order to test, so I used the
Linux kernel repository with a few commits that are slightly off of the
first-parent history. I timed the following command:
The first two commits have similar generation and are near the v5.10
tag. Commit 160bab43419e is off of the first-parent history behind v5.5,
while the others are scattered somewhere reachable from v5.9. This is
designed to demonstrate the optimization, as that commit within v5.5
would normally cause a lot of extra commit walking.
Since remove_redundant_with_alg() is called only when at least one of
the input commits has a finite generation number, this algorithm is
tested with a commit-graph generated starting at a number of different
tags, the earliest being v5.5.
Note that these are only modest improvements for the case where the two
independent commits are not in the commit-graph (not until v5.10). All
algorithms get faster as more commits are indexed, which is not a
surprise. However, the cost of walking extra commits is more and more
prevalent in relative terms as more commits are indexed. Finally, the
last case allows us to jump to the minimum generation between the last
two commits (that are actually independent) so we greatly reduce the
cost in that case.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Fri, 19 Feb 2021 12:34:09 +0000 (12:34 +0000)]
commit-reach: use heuristic in remove_redundant()
Reachability algorithms in commit-reach.c frequently benefit from using
the first-parent history as a heuristic for satisfying reachability
queries. The most obvious example was implemented in 4fbcca4e
(commit-reach: make can_all_from_reach... linear, 2018-07-20).
Update the walk in remove_redundant() to use this same heuristic. Here,
we are walking starting at the parents of the input commits. Sort those
parents and walk from the highest generation to lower. Each time, use
the heuristic of searching the first parent history before continuing to
expand the walk.
The order in which we explore the commits matters, so update
compare_commits_by_gen to break generation number ties with commit date.
This has no effect when the commits are in a commit-graph file with
corrected commit dates computed, but it will assist when the commits are
in the region "above" the commit-graph with "infinite" generation
number. Note that we cannot shift to use
compare_commits_by_gen_then_commit_date as the method prototype is
different. We use compare_commits_by_gen for QSORT() as opposed to as a
priority function.
The important piece is to ensure we short-circuit the walk when we find
that there is a single non-redundant commit. This happens frequently
when looking for merge-bases or comparing several tags with 'git
merge-base --independent'. Use a new count 'count_still_independent' and
if that hits 1 we can stop walking.
To update 'count_still_independent' properly, we add use of the RESULT
flag on the input commits. Then we can detect when we reach one of these
commits and decrease the count. We need to remove the RESULT flag at
that moment because we might re-visit that commit when popping the
stack.
We use the STALE flag to mark parents that have been added to the new
walk_start list, but we need to clear that flag before we start walking
so those flags don't halt our depth-first-search walk.
On my copy of the Linux kernel repository, the performance of 'git
merge-base --independent <all-tags>' goes from 1.1 seconds to 0.11
seconds.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Fri, 19 Feb 2021 12:34:07 +0000 (12:34 +0000)]
commit-reach: use one walk in remove_redundant()
The current implementation of remove_redundant() uses several calls to
paint_down_to_common() to determine that commits are independent of each
other. This leads to quadratic behavior when many inputs are passed to
commands such as 'git merge-base'.
For example, in the Linux kernel repository, I tested the performance
by passing all tags:
(Note: I had to delete the tags v2.6.11-tree and v2.6.11 as they do
not point to commits.)
Here is the performance improvement introduced by this change:
Before: 16.4s
After: 1.1s
This performance improvement requires the commit-graph file to be
present. We keep the old algorithm around as remove_redundant_no_gen()
and use it when generation_numbers_enabled() is false. This is similar
to other algorithms within commit-reach.c. The new algorithm is
implemented in remove_redundant_with_gen().
The basic approach is to do one commit walk instead of many. First, scan
all commits in the list and mark their _parents_ with the STALE flag.
This flag will indicate commits that are reachable from one of the
inputs, except not including themselves. Then, walk commits until
covering all commits up to the minimum generation number pushing the
STALE flag throughout.
At the end, we need to clear the STALE bit from all of the commits
we walked. We move the non-stale commits in 'array' to the beginning of
the list, and this might overwrite stale commits. However, we store an
array of commits that started the walk, and use clear_commit_marks() on
each of those starting commits. That method will walk the reachable
commits with the STALE bit and clear them all. This makes the algorithm
safe for re-entry or for other uses of those commits after this walk.
This logic is covered by tests in t6600-test-reach.sh, so the behavior
does not change. This is tested both in the case with a commit-graph and
without.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Knowing about the core.bigFileThreshold configuration variable is
helpful when examining pack file size differences between repositories.
Add a reference to it to the manpages a user is likely to read in this
situation.
Capitalize CONFIGURATION for consistency with other pages having such a
section.
Signed-off-by: Christian Walther <cwalther@gmx.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Tan [Mon, 22 Feb 2021 19:20:09 +0000 (11:20 -0800)]
fetch-pack: print and use dangling .gitmodules
Teach index-pack to print dangling .gitmodules links after its "keep" or
"pack" line instead of declaring an error, and teach fetch-pack to check
such lines printed.
This allows the tree side of the .gitmodules link to be in one packfile
and the blob side to be in another without failing the fsck check,
because it is now fetch-pack which checks such objects after all
packfiles have been downloaded and indexed (and not index-pack on an
individual packfile, as it is before this commit).
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
projects / thirdparty / git.git / log
