reftable/merged: reuse buffer to compute record keys
When iterating over entries in the merged iterator's queue, we compute
the key of each of the entries and write it into a buffer. We do not
reuse the buffer though and thus re-allocate it on every iteration,
which is wasteful given that we never transfer ownership of the
allocated bytes outside of the loop.
Refactor the code to reuse the buffer. This also fixes a potential
memory leak when `merged_iter_advance_subiter()` returns an error.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When writing a new reftable stack, Git will first create the stack with
a random suffix so that concurrent updates will not try to write to the
same file. This random suffix is computed via a call to rand(3P). But we
never seed the function via srand(3P), which means that the suffix is in
fact always the same.
Fix this bug by using `git_rand()` instead, which does not need to be
initialized. While this function is likely going to be slower depending
on the platform, this slowness should not matter in practice as we only
use it when writing a new reftable stack.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When starting a transaction via `reftable_stack_init_addition()`, we
create a lockfile for the reftable stack itself which we'll write the
new list of tables to. But if we terminate abnormally e.g. via a call to
`die()`, then we do not remove the lockfile. Subsequent executions of
Git which try to modify references will thus fail with an out-of-date
error.
Fix this bug by registering the lock as a `struct tempfile`, which
ensures automatic cleanup for us.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
reftable/stack: reuse buffers when reloading stack
In `reftable_stack_reload_once()` we iterate over all the tables added
to the stack in order to figure out whether any of the tables needs to
be reloaded. We use a set of buffers in this context to compute the
paths of these tables, but discard those buffers on every iteration.
This is quite wasteful given that we do not need to transfer ownership
of the allocated buffer outside of the loop.
Refactor the code to instead reuse the buffers to reduce the number of
allocations we need to do. Note that we do not have to manually reset
the buffer because `stack_filename()` does this for us already.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
reftable/stack: perform auto-compaction with transactional interface
Whenever updating references or reflog entries in the reftable stack, we
need to add a new table to the stack, thus growing the stack's length by
one. The stack can grow to become quite long rather quickly, leading to
performance issues when trying to read records. But besides performance
issues, this can also lead to exhaustion of file descriptors very
rapidly as every single table requires a separate descriptor when
opening the stack.
While git-pack-refs(1) fixes this issue for us by merging the tables, it
runs too irregularly to keep the length of the stack within reasonable
limits. This is why the reftable stack has an auto-compaction mechanism:
`reftable_stack_add()` will call `reftable_stack_auto_compact()` after
its added the new table, which will auto-compact the stack as required.
But while this logic works alright for `reftable_stack_add()`, we do not
do the same in `reftable_addition_commit()`, which is the transactional
equivalent to the former function that allows us to write multiple
updates to the stack atomically. Consequentially, we will easily run
into file descriptor exhaustion in code paths that use many separate
transactions like e.g. non-atomic fetches.
Fix this issue by calling `reftable_stack_auto_compact()`.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
reftable/stack: verify that `reftable_stack_add()` uses auto-compaction
While we have several tests that check whether we correctly perform
auto-compaction when manually calling `reftable_stack_auto_compact()`,
we don't have any tests that verify whether `reftable_stack_add()` does
call it automatically. Add one.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are calls to pread(3P) and read(3P) where we don't properly handle
interrupts. Convert them to use `pread_in_full()` and `read_in_full()`,
respectively.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `EXPECT` macros used by the reftable test framework are all using a
single `if` statement with the actual condition. This results in weird
syntax when using them in if/else statements like the following:
Note that there need not be a trailing semicolon. Furthermore, it is not
immediately obvious whether the else now belongs to the `if (foo)` or
whether it belongs to the expanded `if (foo == 2)` from the macro.
Fix this by wrapping the macros in a do/while loop.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Victoria Dye [Mon, 13 Nov 2023 23:17:51 +0000 (23:17 +0000)]
glossary: add definitions for dereference & peel
Add 'gitglossary' definitions for "dereference" (as it used for both symrefs
and objects) and "peel". These terms are used in options and documentation
throughout Git, but they are not clearly defined anywhere and the behavior
they refer to depends heavily on context. Provide explicit definitions to
clarify existing documentation to users and help contributors to use the
most appropriate terminology possible in their additions to Git.
Update other definitions in the glossary that use the term "dereference" to
link to 'def_dereference'.
Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Wed, 8 Nov 2023 06:04:41 +0000 (15:04 +0900)]
Merge branch 'ps/leakfixes'
Leakfix.
* ps/leakfixes:
setup: fix leaking repository format
setup: refactor `upgrade_repository_format()` to have common exit
shallow: fix memory leak when registering shallow roots
test-bloom: stop setting up Git directory twice
Junio C Hamano [Wed, 8 Nov 2023 02:04:01 +0000 (11:04 +0900)]
Merge branch 'kn/rev-list-missing-fix'
"git rev-list --missing" did not work for missing commit objects,
which has been corrected.
* kn/rev-list-missing-fix:
rev-list: add commit object support in `--missing` option
rev-list: move `show_commit()` to the bottom
revision: rename bit to `do_not_die_on_missing_objects`
Junio C Hamano [Wed, 8 Nov 2023 02:03:59 +0000 (11:03 +0900)]
Merge branch 'ps/show-ref'
Teach "git show-ref" a mode to check the existence of a ref.
* ps/show-ref:
t: use git-show-ref(1) to check for ref existence
builtin/show-ref: add new mode to check for reference existence
builtin/show-ref: explicitly spell out different modes in synopsis
builtin/show-ref: ensure mutual exclusiveness of subcommands
builtin/show-ref: refactor options for patterns subcommand
builtin/show-ref: stop using global vars for `show_one()`
builtin/show-ref: stop using global variable to count matches
builtin/show-ref: refactor `--exclude-existing` options
builtin/show-ref: fix dead code when passing patterns
builtin/show-ref: fix leaking string buffer
builtin/show-ref: split up different subcommands
builtin/show-ref: convert pattern to a local variable
The codepath to traverse the commit-graph learned to notice that a
commit is missing (e.g., corrupt repository lost an object), even
though it knows something about the commit (like its parents) from
what is in commit-graph.
* ps/do-not-trust-commit-graph-blindly-for-existence:
commit: detect commits that exist in commit-graph but not in the ODB
commit-graph: introduce envvar to disable commit existence checks
Taylor Blau [Mon, 6 Nov 2023 22:56:33 +0000 (17:56 -0500)]
pack-bitmap: drop --unpacked non-commit objects from results
When performing revision queries with `--objects` and
`--use-bitmap-index`, the output may incorrectly contain objects which
are packed, even when the `--unpacked` option is given. This affects
traversals, but also other querying operations, like `--count`,
`--disk-usage`, etc.
Like in the previous commit, the fix is to exclude those objects from
the result set before they are shown to the user (or, in this case,
before the bitmap containing the result of the traversal is enumerated
and its objects listed).
This is performed by a new function in pack-bitmap.c, called
`filter_packed_objects_from_bitmap()`. Note that we do not have to
inspect individual bits in the result bitmap, since we know that the
first N (where N is the number of objects in the bitmap's pack/MIDX)
bits correspond to objects which packed by definition.
In other words, for an object to have a bitmap position (not in the
extended index), it must appear in either the bitmap's pack or one of
the packs in its MIDX.
This presents an appealing optimization to us, which is that we can
simply memset() the corresponding number of `eword_t`'s to zero,
provided that we handle any objects which spill into the next word (but
don't occupy all 64 bits of the word itself).
We only have to handle objects in the bitmap's extended index. These
objects may (or may not) appear in one or more pack(s). Since these
objects are known to not appear in either the bitmap's MIDX or pack,
they may be stored as loose, appear in other pack(s), or both.
Before returning a bitmap containing the result of the traversal back to
the caller, drop any bits from the extended index which appear in one or
more packs. This implements the correct behavior for rev-list operations
which use the bitmap index to compute their result.
Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Mon, 6 Nov 2023 22:56:30 +0000 (17:56 -0500)]
list-objects: drop --unpacked non-commit objects from results
In git-rev-list(1), we describe the `--unpacked` option as:
Only useful with `--objects`; print the object IDs that are not in
packs.
This is true of commits, which we discard via get_commit_action(), but
not of the objects they reach. So if we ask for an --objects traversal
with --unpacked, we may get arbitrarily many objects which are indeed
packed.
I am nearly certain this behavior dates back to the introduction of
`--unpacked` via 12d2a18780 ("git rev-list --unpacked" shows only
unpacked commits, 2005-07-03), but I couldn't get that revision of Git
to compile for me. At least as early as v2.0.0 this has been subtly
broken:
There, only the first, third, and sixth entries are loose, with the
remaining set of objects belonging to at least one pack.
The implications for this are relatively benign: bare 'git repack'
invocations which invoke pack-objects with --unpacked are impacted, and
at worst we'll store a few extra objects that should have been excluded.
Arguably changing this behavior is a backwards-incompatible change,
since it alters the set of objects emitted from rev-list queries with
`--objects` and `--unpacked`. But I argue that this change is still
sensible, since the existing implementation deviates from
clearly-written documentation.
The fix here is straightforward: avoid showing any non-commit objects
which are contained in packs by discarding them within list-objects.c,
before they are shown to the user. Note that similar treatment for
`list-objects.c::show_commit()` is not needed, since that case is
already handled by `revision.c::get_commit_action()`.
Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Todd Zullinger [Fri, 3 Nov 2023 14:17:51 +0000 (10:17 -0400)]
RelNotes: improve wording of credential helper notes
Offer a slightly more verbose description of the issue fixed by 7144dee3ec (credential/libsecret: erase matching creds only, 2023-07-26)
and cb626f8e5c (credential/wincred: erase matching creds only,
2023-07-26).
Signed-off-by: Todd Zullinger <tmz@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 7 Nov 2023 01:26:44 +0000 (10:26 +0900)]
Merge branch 'ms/send-email-validate-fix'
"git send-email" did not have certain pieces of data computed yet
when it tried to validate the outging messages and its recipient
addresses, which has been sorted out.
Junio C Hamano [Tue, 7 Nov 2023 01:26:43 +0000 (10:26 +0900)]
Merge branch 'jc/grep-f-relative-to-cwd'
"cd sub && git grep -f patterns" tried to read "patterns" file at
the top level of the working tree; it has been corrected to read
"sub/patterns" instead.
* jc/grep-f-relative-to-cwd:
grep: -f <path> is relative to $cwd
While populating the `repository_format` structure may cause us to
allocate memory, we do not call `clear_repository_format()` in some
places and thus potentially leak memory. Fix this.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
setup: refactor `upgrade_repository_format()` to have common exit
The `upgrade_repository_format()` function has multiple exit paths,
which means that there is no common cleanup of acquired resources.
While this isn't much of a problem right now, we're about to fix a
memory leak that would require us to free the resource in every one of
those exit paths.
Refactor the code to have a common exit path so that the subsequent
memory leak fix becomes easier to implement.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
shallow: fix memory leak when registering shallow roots
When registering shallow roots, we unset the list of parents of the
to-be-registered commit if it's already been parsed. This causes us to
leak memory though because we never free this list. Fix this.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're setting up the Git directory twice in the `test-tool bloom`
helper, once at the beginning of `cmd_bloom()` and once in the local
subcommand implementation `get_bloom_filter_for_commit()`. This can lead
to memory leaks as we'll overwrite variables of `the_repository` with
newly allocated data structures. On top of that it's simply unnecessary.
Fix this by only setting up the Git directory once.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Fri, 3 Nov 2023 16:20:19 +0000 (12:20 -0400)]
t: avoid perl's pack/unpack "Q" specifier
The perl script introduced by 86b008ee61 (t: add library for munging
chunk-format files, 2023-10-09) uses pack("Q") and unpack("Q") to read
and write 64-bit values ("quadwords" in perl parlance) from the on-disk
chunk files. However, some builds of perl may not support 64-bit
integers at all, and throw an exception here. While some 32-bit
platforms may still support 64-bit integers in perl (such as our linux32
CI environment), others reportedly don't (the NonStop 32-bit builds).
We can work around this by treating the 64-bit values as two 32-bit
values. We can't ever combine them into a single 64-bit value, but in
practice this is OK. These are representing file offsets, and our files
are much smaller than 4GB. So the upper half of the 64-bit value will
always be 0.
We can just introduce a few helper functions which perform the
translation and double-check our assumptions.
Reported-by: Randall S. Becker <randall.becker@nexbridge.ca> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
In April, GitHub announced that the `macos-13` pool is available:
https://github.blog/changelog/2023-04-24-github-actions-macos-13-is-now-available/.
It is only a matter of time until the `macos-12` pool is going away,
therefore we should switch now, without pressure of a looming deadline.
Since the `macos-13` runners no longer include Python2, we also drop
specifically testing with Python2 and switch uniformly to Python3, see
https://github.com/actions/runner-images/blob/HEAD/images/macos/macos-13-Readme.md
for details about the software available on the `macos-13` pool's
runners.
Also, on macOS 13, Homebrew seems to install a `gcc@9` package that no
longer comes with a regular `unistd.h` (there seems only to be a
`ssp/unistd.h`), and hence builds would fail with:
In file included from base85.c:1:
git-compat-util.h:223:10: fatal error: unistd.h: No such file or directory
223 | #include <unistd.h>
| ^~~~~~~~~~
compilation terminated.
The reason why we install GCC v9.x explicitly is historical, and back in
the days it was because it was the _newest_ version available via
Homebrew: 176441bfb58 (ci: build Git with GCC 9 in the 'osx-gcc' build
job, 2019-11-27).
To reinstate the spirit of that commit _and_ to fix that build failure,
let's switch to the now-newest GCC version: v13.x.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Linus Arver [Thu, 2 Nov 2023 20:51:17 +0000 (20:51 +0000)]
strvec: drop unnecessary include of hex.h
In 41771fa435 (cache.h: remove dependence on hex.h; make other files
include it explicitly, 2023-02-24) we added this as part of a larger
mechanical refactor. But strvec doesn't actually depend on hex.h, so
remove it.
Signed-off-by: Linus Arver <linusa@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 31 Oct 2023 05:23:30 +0000 (14:23 +0900)]
tests: teach callers of test_i18ngrep to use test_grep
They are equivalents and the former still exists, so as long as the
only change this commit makes are to rewrite test_i18ngrep to
test_grep, there won't be any new bug, even if there still are
callers of test_i18ngrep remaining in the tree, or when merged to
other topics that add new uses of test_i18ngrep.
and a good way to sanity check the result yourself is to run the
above in a checkout of c4603c1c (test framework: further deprecate
test_i18ngrep, 2023-10-31) and compare the resulting working tree
contents with the result of applying this patch to the same commit.
You'll see that test_i18ngrep in a few t/lib-*.sh files corrected,
in addition to the manual reproduction.