The ref and reflog iterators have their lifecycle attached to iteration:
once the iterator reaches its end, it is automatically released and the
caller doesn't have to care about that anymore. When the iterator should
be released before it has been exhausted, callers must explicitly abort
the iterator via `ref_iterator_abort()`.
This lifecycle is somewhat unusual in the Git codebase and creates two
problems:
- Callsites need to be very careful about when exactly they call
`ref_iterator_abort()`, as calling the function is only valid when
the iterator itself still is. This leads to somewhat awkward calling
patterns in some situations.
- It is impossible to reuse iterators and re-seek them to a different
prefix. This feature isn't supported by any iterator implementation
except for the reftable iterators anyway, but if it was implemented
it would allow us to optimize cases where we need to search for
specific references repeatedly by reusing internal state.
Detangle the lifecycle from iteration so that we don't deallocate the
iterator anymore once it is exhausted. Instead, callers are now expected
to always call a newly introduce `ref_iterator_free()` function that
deallocates the iterator and its internal state.
Note that the `dir_iterator` is somewhat special because it does not
implement the `ref_iterator` interface, but is only used to implement
other iterators. Consequently, we have to provide `dir_iterator_free()`
instead of `dir_iterator_release()` as the allocated structure itself is
managed by the `dir_iterator` interfaces, as well, and not freed by
`ref_iterator_free()` like in all the other cases.
While at it, drop the return value of `ref_iterator_abort()`, which
wasn't really required by any of the iterator implementations anyway.
Furthermore, stop calling `base_ref_iterator_free()` in any of the
backends, but instead call it in `ref_iterator_free()`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One of the checks done by `refs_verify_refnames_available()` is whether
any of the prefixes of a reference already exists. For example, given a
reference "refs/heads/main", we'd check whether "refs/heads" or "refs"
already exist, and if so we'd abort the transaction.
When updating multiple references at once, this check is performed for
each of the references individually. Consequently, because references
tend to have common prefixes like "refs/heads/" or refs/tags/", we
evaluate the availability of these prefixes repeatedly. Naturally this
is a waste of compute, as the availability of those prefixes should in
general not change in the middle of a transaction. And if it would,
backends would notice at a later point in time.
Optimize this pattern by storing prefixes in a `strset` so that we can
trivially track those prefixes that we have already checked. This leads
to a significant speedup with the "reftable" backend when creating many
references that all share a common prefix:
Benchmark 1: update-ref: create many refs (refformat = reftable, preexisting = 100000, new = 10000, revision = HEAD~)
Time (mean ± σ): 63.1 ms ± 1.8 ms [User: 41.0 ms, System: 21.6 ms]
Range (min … max): 60.6 ms … 69.5 ms 38 runs
Benchmark 2: update-ref: create many refs (refformat = reftable, preexisting = 100000, new = 10000, revision = HEAD)
Time (mean ± σ): 40.0 ms ± 1.3 ms [User: 29.3 ms, System: 10.3 ms]
Range (min … max): 38.1 ms … 47.3 ms 61 runs
Summary
update-ref: create many refs (refformat = reftable, preexisting = 100000, new = 10000, revision = HEAD) ran
1.58 ± 0.07 times faster than update-ref: create many refs (refformat = reftable, preexisting = 100000, new = 10000, revision = HEAD~)
For the "files" backend we see an improvement, but a much smaller one:
Benchmark 1: update-ref: create many refs (refformat = files, preexisting = 100000, new = 10000, revision = HEAD~)
Time (mean ± σ): 395.8 ms ± 5.3 ms [User: 63.6 ms, System: 330.5 ms]
Range (min … max): 387.0 ms … 404.6 ms 10 runs
Benchmark 2: update-ref: create many refs (refformat = files, preexisting = 100000, new = 10000, revision = HEAD)
Time (mean ± σ): 386.0 ms ± 4.0 ms [User: 51.5 ms, System: 332.8 ms]
Range (min … max): 380.8 ms … 392.6 ms 10 runs
Summary
update-ref: create many refs (refformat = files, preexisting = 100000, new = 10000, revision = HEAD) ran
1.03 ± 0.02 times faster than update-ref: create many refs (refformat = files, preexisting = 100000, new = 10000, revision = HEAD~)
This change also leads to a modest improvement when writing references
with "initial" semantics, for example when migrating references. The
following benchmarks are migrating 1m references from the "reftable" to
the "files" backend:
Benchmark 1: migrate reftable:files (refcount = 1000000, revision = HEAD~)
Time (mean ± σ): 836.6 ms ± 5.6 ms [User: 645.2 ms, System: 185.2 ms]
Range (min … max): 829.6 ms … 845.9 ms 10 runs
Benchmark 2: migrate reftable:files (refcount = 1000000, revision = HEAD)
Time (mean ± σ): 759.8 ms ± 5.1 ms [User: 574.9 ms, System: 178.9 ms]
Range (min … max): 753.1 ms … 768.8 ms 10 runs
Summary
migrate reftable:files (refcount = 1000000, revision = HEAD) ran
1.10 ± 0.01 times faster than migrate reftable:files (refcount = 1000000, revision = HEAD~)
And vice versa:
Benchmark 1: migrate files:reftable (refcount = 1000000, revision = HEAD~)
Time (mean ± σ): 870.7 ms ± 5.7 ms [User: 735.2 ms, System: 127.4 ms]
Range (min … max): 861.6 ms … 883.2 ms 10 runs
Benchmark 2: migrate files:reftable (refcount = 1000000, revision = HEAD)
Time (mean ± σ): 799.1 ms ± 8.5 ms [User: 661.1 ms, System: 130.2 ms]
Range (min … max): 787.5 ms … 812.6 ms 10 runs
Summary
migrate files:reftable (refcount = 1000000, revision = HEAD) ran
1.09 ± 0.01 times faster than migrate files:reftable (refcount = 1000000, revision = HEAD~)
The impact here is significantly smaller given that we don't perform any
reference reads with "initial" semantics, so the speedup only comes from
us doing less string list lookups.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "files" backend explicitly carves out special logic for its initial
transaction so that it can avoid writing out every single reference as
a loose reference. While the assumption is that there shouldn't be any
preexisting references, we still have to verify that none of the newly
written references will conflict with any other new reference in the
same transaction.
Refactor the initial transaction to use batched refname availability
checks. This does not yet have an effect on performance as we still call
`refs_verify_refname_available()` in a loop. But this will change in
subsequent commits and then impact performance when cloning a repository
with many references or when migrating references to the "files" format.
This will improve performance when cloning a repository with many
references or when migrating references from any format to the "files"
format once the availability checks have learned to optimize checks for
many references in a subsequent commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Same as the "reftable" backend that we have adapted in the preceding
commit to use batched refname availability checks we can also do so for
the "files" backend. Things are a bit more intricate here though, as we
call `refs_verify_refname_available()` in a set of different contexts:
1. `lock_raw_ref()` when it hits either EEXISTS or EISDIR when creating
a new reference, mostly to create a nice, user-readable error
message. This is nothing we have to care about too much, as we only
hit this code path at most once when we hit a conflict.
2. `lock_raw_ref()` when it _could_ create the lockfile to check
whether it is conflicting with any packed refs. In the general case,
this code path will be hit once for every (successful) reference
update.
3. `lock_ref_oid_basic()`, but it is only executed when copying or
renaming references or when expiring reflogs. It will thus not be
called in contexts where we have many references queued up.
4. `refs_refname_ref_available()`, but again only when copying or
renaming references. It is thus not interesting due to the same
reason as the previous case.
5. `files_transaction_finish_initial()`, which is only executed when
creating a new repository or migrating references.
So out of these, only (2) and (5) are viable candidates to use the
batched checks.
Adapt `lock_raw_ref()` accordingly by queueing up reference names that
need to be checked for availability and then checking them after we have
processed all updates. This check is done before we (optionally) lock
the `packed-refs` file, which is somewhat flawed because it means that
the `packed-refs` could still change after the availability check and
thus create an undetected conflict. But unconditionally locking the file
would change semantics that users are likely to rely on, so we keep the
current locking sequence intact, even if it's suboptmial.
The refactoring of `files_transaction_finish_initial()` will be done in
the next commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactor the "reftable" backend to batch the availability check for
refnames. This does not yet have an effect on performance as
`refs_verify_refnames_available()` effectively still performs the
availability check for each refname individually. But this will be
optimized in subsequent commits, where we learn to optimize some parts
of the logic when checking multiple refnames for availability.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `refs_verify_refname_available()` functions checks whether a
reference update can be committed or whether it would conflict with
either a prefix or suffix thereof. This function needs to be called once
per reference that one wants to check, which requires us to redo a
couple of checks every time the function is called.
Introduce a new function `refs_verify_refnames_available()` that does
the same, but for a list of references. For now, the new function uses
the exact same implementation, except that we loop through all refnames
provided by the caller. This will be tuned in subsequent commits.
The existing `refs_verify_refname_available()` function is reimplemented
on top of the new function. As such, the diff is best viewed with the
`--ignore-space-change option`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of the commands in git-update-ref(1) accept an old and/or new
object ID to update a specific reference to. These object IDs get parsed
via `repo_get_oid()`, which not only handles plain object IDs, but also
those that have a suffix like "~" or "^2". More surprisingly though, it
even knows to resolve arbitrary revisions, despite the fact that its
manpage does not mention this fact even once.
One consequence of this is that we also check for ambiguous references:
when parsing a full object ID where the DWIM mechanism would also cause
us to resolve it as a branch, we'd end up printing a warning. While this
check makes sense to have in general, it is arguably less useful in the
context of git-update-ref(1). This is due to multiple reasons:
- The manpage is explicitly structured around object IDs. So if we see
a fully blown object ID, the intent should be quite clear in
general.
- The command is part of our plumbing layer and not a tool that users
would generally use in interactive workflows. As such, the warning
will likely not be visible to anybody in the first place.
- Users can and should use the fully-qualified refname in case there
is any potential for ambiguity. And given that this command is part
of our plumbing layer, one should always try to be as defensive as
possible and use fully-qualified refnames.
Furthermore, this check can be quite expensive when updating lots of
references via `--stdin`, because we try to read multiple references per
object ID that we parse according to the DWIM rules. This effect can be
seen both with the "files" and "reftable" backend.
The issue is not unique to git-update-ref(1), but was also an issue in
git-cat-file(1), where it was addressed by disabling the ambiguity check
in 25fba78d36 (cat-file: disable object/refname ambiguity check for
batch mode, 2013-07-12).
Disable the warning in git-update-ref(1), which provides a significant
speedup with both backends. The user-visible outcome is unchanged even
when ambiguity exists, except that we don't show the warning anymore.
The following benchmark creates 10000 new references with a 100000
preexisting refs with the "files" backend:
Benchmark 1: update-ref: create many refs (refformat = files, preexisting = 100000, new = 10000, revision = HEAD~)
Time (mean ± σ): 467.3 ms ± 5.1 ms [User: 100.0 ms, System: 365.1 ms]
Range (min … max): 461.9 ms … 479.3 ms 10 runs
Benchmark 2: update-ref: create many refs (refformat = files, preexisting = 100000, new = 10000, revision = HEAD)
Time (mean ± σ): 394.1 ms ± 5.8 ms [User: 63.3 ms, System: 327.6 ms]
Range (min … max): 384.9 ms … 405.7 ms 10 runs
Summary
update-ref: create many refs (refformat = files, preexisting = 100000, new = 10000, revision = HEAD) ran
1.19 ± 0.02 times faster than update-ref: create many refs (refformat = files, preexisting = 100000, new = 10000, revision = HEAD~)
And with the "reftable" backend:
Benchmark 1: update-ref: create many refs (refformat = reftable, preexisting = 100000, new = 10000, revision = HEAD~)
Time (mean ± σ): 146.9 ms ± 2.2 ms [User: 90.4 ms, System: 56.0 ms]
Range (min … max): 142.7 ms … 150.8 ms 19 runs
Benchmark 2: update-ref: create many refs (refformat = reftable, preexisting = 100000, new = 10000, revision = HEAD)
Time (mean ± σ): 63.2 ms ± 1.1 ms [User: 41.0 ms, System: 21.8 ms]
Range (min … max): 61.1 ms … 66.6 ms 41 runs
Summary
update-ref: create many refs (refformat = reftable, preexisting = 100000, new = 10000, revision = HEAD) ran
2.32 ± 0.05 times faster than update-ref: create many refs (refformat = reftable, preexisting = 100000, new = 10000, revision = HEAD~)
Note that the absolute improvement with both backends is roughly in the
same ballpark, but the relative improvement for the "reftable" backend
is more significant because writing the new table to disk is faster in
the first place.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When reading an object ID via `get_oid_basic()` or any of its related
functions we perform a check whether the object ID is ambiguous, which
can be the case when a reference with the same name exists. While the
check is generally helpful, there are cases where it only adds to the
runtime overhead without providing much of a benefit.
Add a new flag that allows us to disable the check. The flag will be
used in a subsequent commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new function `repo_get_oid_with_flags()`. This function
behaves the same as `repo_get_oid()`, except that it takes an extra
`flags` parameter that it ends up passing to `get_oid_with_context()`.
This function will be used in a subsequent commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Upgrade the minimum Perl version enforced by meson-based build to
match what Makefile-based build uses.
* po/meson-perl-fix:
meson: fix Perl version check for Meson versions before 1.7.0
meson: bump minimum required Perl version to 5.26.0
Correct the default target in Documentation/Makefile, and
future-proof all Makefiles from similar breakages by declaring the
default target (which happens to be "all") upfront.
* ad/set-default-target-in-makefiles:
Makefile: set default goals in makefiles
"git merge-tree --stdin" has been improved (including a workaround
for a deadlock).
* pw/merge-tree-stdin-deadlock-fix:
merge-tree: fix link formatting in html docs
merge-tree: improve docs for --stdin
merge-tree: only use basic merge config
merge-tree: remove redundant code
merge-tree --stdin: flush stdout to avoid deadlock
The documentation of "git commit" and "git rebase" now refer to
commit titles as such, not "subject".
* mh/doc-commit-title-not-subject:
doc: use 'title' consistently
The -G/-S options to the "diff" family of commands caused us to hit
a BUG() when they get no values; they have been corrected.
* bc/diff-reject-empty-arg-to-pickaxe:
diff: don't crash with empty argument to -G or -S
Noises from "-Wsign-compare" in the borrowed xdiff code has been
squelched.
* da/xdiff-w-sign-compare-workaround:
xdiff: avoid signed vs. unsigned comparisons in xutils.c
xdiff: avoid signed vs. unsigned comparisons in xpatience.c
xdiff: avoid signed vs. unsigned comparisons in xhistogram.c
xdiff: avoid signed vs. unsigned comparisons in xemit.c
xdiff: avoid signed vs. unsigned comparisons in xdiffi.c
xdiff: move sign comparison warning guard into each file
I recently had reported to me a crash from a coworker using the recently
added sendemail mailmap support:
3724814 Segmentation fault (core dumped) git check-mailmap "bugs@company.xx"
This appears to happen because of the NULL pointer name passed into
map_user(). Fix this by passing "" instead of NULL so that we have a
valid pointer.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Two configuration variables about SSL authentication material that
weren't mentioned in the documentations are now mentioned.
* ac/doc-http-ssl-type-config:
docs: indicate http.sslCertType and sslKeyType
Since 183ea3ea (Merge branch 'ps/mingw-rename', 2024-11-13),
a new technique is used on Windows to rename files, where supported.
The first step of this technique is to open the file with
`CreateFileW`. At that time, `FILE_ATTRIBUTE_NORMAL` was passed as
the value of the `dwFlagsAndAttributes` argument. In b30404df [2], this
was improved by passing `FILE_FLAG_BACKUP_SEMANTICS`, to support
directories as well as regular files.
However, neither value of `dwFlagsAndAttributes` is sufficient to open
a symbolic link with the correct semantics to rename it. Symlinks on
Windows are reparse points. Attempting to open a reparse point with
`CreateFileW` dereferences the reparse point and opens the target
instead, unless `FILE_FLAG_OPEN_REPARSE_POINT` is included in
`dwFlagsAndAttributes`. This is documented for that flag and in the
"Symbolic Link Behavior" section of the `CreateFileW` docs [3].
This produces a regression where attempting to rename a symlink on
Windows renames its target to the intended new name and location of the
symlink. For example, if `symlink` points to `file`, then running
git mv symlink symlink-renamed
leaves `symlink` in place and unchanged, but renames `file` to
`symlink-renamed` [4].
This regression is detectable by existing tests in `t7001-mv.sh`, but
the tests must be run by a Windows user with the ability to create
symlinks, and the `ln -s` command used to create the initial symlink
must also be able to create a real symlink (such as by setting the
`MSYS` environment variable to `winsymlinks:nativestrict`). Then
these two tests fail if the regression is present, and pass otherwise:
38 - git mv should overwrite file with a symlink
39 - check moved symlink
Let's fix this, so that renaming a symlink again renames the symlink
itself and leaves the target unchanged, by passing
FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT
as the `dwFlagsAndAttributes` argument. This is sufficient (and safe)
because including `FILE_FLAG_OPEN_REPARSE_POINT` causes no harm even
when used to open a file or directory that is not a reparse point. In
that case, as noted in [3], this flag is simply ignored.
[1]: 183ea3eabf
[2]: b30404dfc0
[3]: https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilew
[4]: https://github.com/git-for-windows/git/issues/5436
Signed-off-by: Eliah Kagan <eliah.kagan@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* 'master' of https://github.com/j6t/gitk:
gitk: introduce support for the Meson build system
gitk: extract script to build executable
gitk: make the "list references" default window width wider
gitk: fix arrow keys in input fields with Tcl/Tk >= 8.6
gitk: Use an external icon file on Windows
gitk: Unicode file name support
gitk(Windows): avoid inadvertently calling executables in the worktree
* 'pks-meson-support' of https://github.com/pks-t/gitk:
gitk: introduce support for the Meson build system
gitk: extract script to build executable
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
* 'g4w-gitk' of https://github.com/dscho/gitk:
gitk: make the "list references" default window width wider
gitk: fix arrow keys in input fields with Tcl/Tk >= 8.6
gitk: Use an external icon file on Windows
gitk: Unicode file name support
gitk(Windows): avoid inadvertently calling executables in the worktree
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Upstream Git has introduced support for the Meson build system.
Introduce support for Meson into gitk, as well, so that Git can easily
build its vendored copy of Gitk via a `subproject()` directive. The
instructions can be set up as follows:
$ meson setup build
$ meson compile -C build
$ meson install -C build
Specific options, like for example where Gitk shall be installed to, can
be specified at setup time via `-D`. Available options can be discovered
by running `meson configure` either in the source or build directory.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Command `perl --version` says, e.g., “This is perl 5, version 26,
subversion 0 (v5.26.0)”, which older versions of Meson interpret as
version 26.
This will be fixed in Meson 1.7.0, but at the time of writing that isn’t
yet released.
If we run `perl -V:version` we get the unambiguous response
“version='5.26.0';”, but we need at least Meson 1.5.0 to be able to do that.
Note that Perl are seriously considering dropping the leading 5 entirely
in the near future (https://perl.github.io/PPCs/ppc0025-perl-version/),
but that shouldn’t affect us.
Signed-off-by: Peter Oliver <git@mavit.org.uk>
Co-authored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 702d8c1f3b (Require Perl 5.26.0, 2024-10-23) dropped support
for Perl versions older than 5.26.0. The Meson build system, which
has been developed in parallel to that commit, hasn't been bumped
accordingly and thus still requires Perl 5.8.1 or newer.
Fix this by requiring Perl 5.26.0 or newer with Meson.
Signed-off-by: Peter Oliver <git@mavit.org.uk>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git difftool" code clean-up.
* da/difftool-sans-the-repository:
difftool: eliminate use of USE_THE_REPOSITORY_VARIABLE
difftool: eliminate use of the_repository
difftool: eliminate use of global variables
"git rev-list --missing=" learned to accept "print-info" that gives
known details expected of the missing objects, like path and type.
* jt/rev-list-missing-print-info:
rev-list: extend print-info to print missing object type
rev-list: add print-info action to print missing object path
"git push --atomic --porcelain" used to ignore failures from the
other side, losing the error status from the child process, which
has been corrected.
* ps/send-pack-unhide-error-in-atomic-push:
send-pack: gracefully close the connection for atomic push
t5543: atomic push reports exit code failure
send-pack: new return code "ERROR_SEND_PACK_BAD_REF_STATUS"
t5548: add porcelain push test cases for dry-run mode
t5548: add new porcelain test cases
t5548: refactor test cases by resetting upstream
t5548: refactor to reuse setup_upstream() function
t5504: modernize test by moving heredocs into test bodies
Lazy-loading missing files in a blobless clone on demand is costly
as it tends to be one-blob-at-a-time. "git backfill" is introduced
to help bulk-download necessary files beforehand.
* ds/backfill:
backfill: assume --sparse when sparse-checkout is enabled
backfill: add --sparse option
backfill: add --min-batch-size=<n> option
backfill: basic functionality and tests
backfill: add builtin boilerplate
The pickaxe options, -G and -S, need either a regex or a string to look
through the history for. An empty value isn't very useful since it
would either match everything or nothing, and what's worse, we presently
crash with a BUG like so when the user provides one:
BUG: diffcore-pickaxe.c:241: should have needle under -G or -S
Since it's not very nice of us to crash and this wouldn't do anything
useful anyway, let's simply inform the user that they must provide a
non-empty argument and exit with an error if they provide an empty one
instead.
Reported-by: Jared Van Bortel <cebtenzzre@gmail.com>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The first line of a commit message is variously called 'title' or
'subject'.
Prefer 'title' unless discussing email.
Signed-off-by: M Hickford <mirth.hickford@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the html documentation the link to the "OUTPUT" section is surrounded
by square brackets. Fix this by adding explicit link text to the cross
reference.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a section for --stdin in the list of options and document that it
implies -z so readers know how to parse the output. Also correct the
merge status documentation for --stdin as if the status is less than
zero "git merge-tree" dies before printing it.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 9c93ba4d0a (merge-recursive: honor diff.algorithm, 2024-07-13)
replaced init_merge_options() with init_basic_merge_config() for use in
plumbing commands and init_ui_merge_config() for use in porcelain
commands. As "git merge-tree" is a plumbing command it should call
init_basic_merge_config() rather than init_ui_merge_config(). The merge
ort machinery ignores "diff.algorithm" so the behavior is unchanged by
this commit but it future proofs us against any future changes to
init_ui_merge_config().
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
real_merge() only ever returns "0" or "1" as it dies if the merge status
is less than zero. Therefore the check for "result < 0" is redundant and
the result variable is not needed. The return value of real_merge() is
ignored because exit status of "git merge-tree --stdin" is "0" for both
successful and conflicted merges (the status of each merge is written to
stdout). The return type of real_merge() is not changed as it is used
for the program's exit status when "--stdin" is not given.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a process tries to read the output from "git merge-tree --stdin"
before it closes merge-tree's stdin then it deadlocks. This happens
because merge-tree does not flush its output before trying to read
another line of input and means that it is not possible to cherry-pick a
sequence of commits using "git merge-tree --stdin". Fix this by calling
maybe_flush_or_die() before trying to read the next line of
input. Flushing the output after each merge does not seem to affect the
performance, any difference is lost in the noise even after increasing
the number of runs.
$ git rev-list --merges --parents -n100 origin/master |
sed 's/^[^ ]* //' >/tmp/merges
$ hyperfine -L flush 0,1 --warmup 1 --runs 30 \
'GIT_FLUSH={flush} ./git merge-tree --stdin </tmp/merges'
Benchmark 1: GIT_FLUSH=0 ./git merge-tree --stdin </tmp/merges
Time (mean ± σ): 546.6 ms ± 11.7 ms [User: 503.2 ms, System: 40.9 ms]
Range (min … max): 535.9 ms … 567.7 ms 30 runs
Benchmark 2: GIT_FLUSH=1 ./git merge-tree --stdin </tmp/merges
Time (mean ± σ): 546.9 ms ± 12.0 ms [User: 505.9 ms, System: 38.9 ms]
Range (min … max): 529.8 ms … 570.0 ms 30 runs
Summary
'GIT_FLUSH=0 ./git merge-tree --stdin </tmp/merges' ran
1.00 ± 0.03 times faster than 'GIT_FLUSH=1 ./git merge-tree --stdin </tmp/merges'
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename `match_name_with_pattern()` to `match_refname_with_pattern()` to
better reflect its purpose and improve documentation comment clarity.
The previous function name and parameter names were inconsistent, making
it harder to understand their roles in refspec matching.
- Rename parameters:
- `key` -> `pattern` (globbing pattern to match)
- `name` -> `refname` (refname to check)
- `value` -> `replacement` (replacement mapping pattern)
Signed-off-by: Meet Soni <meetsoni3017@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
