Check the final reallocation for adding the terminating NULL and handle
it just like those in the loop. Simply use REFTABLE_ALLOC_GROW instead
of keeping the REFTABLE_REALLOC_ARRAY call and adding code to preserve
the original pointer value around it.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When realloc(3) fails, it returns NULL and keeps the original allocation
intact. REFTABLE_ALLOC_GROW overwrites both the original pointer and
the allocation count variable in that case, simultaneously leaking the
original allocation and misrepresenting the number of storable items.
parse_names() avoids the leak by keeping the original pointer if
reallocation fails, but still increase the allocation count in such a
case as if it succeeded. That's OK, because the error handling code
just frees everything and doesn't look at names_cap anymore.
reftable_buf_add() does the same, but here it is a problem as it leaves
the reftable_buf in a broken state, with ->alloc being roughly twice as
big as the actually allocated memory, allowing out-of-bounds writes in
subsequent calls.
Reimplement REFTABLE_ALLOC_GROW to avoid leaks, keep allocation counts
in sync and still signal failures to callers while avoiding code
duplication in callers. Make it an expression that evaluates to 0 if no
reallocation is needed or it succeeded and 1 on failure while keeping
the original pointer and allocation counter values.
Adjust REFTABLE_ALLOC_GROW_OR_NULL to the new calling convention for
REFTABLE_ALLOC_GROW, but keep its support for non-size_t alloc variables
for now.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When realloc(3) fails, it returns NULL and keeps the original allocation
intact. REFTABLE_ALLOC_GROW overwrites both the original pointer and
the allocation count variable in that case, simultaneously leaking the
original allocation and misrepresenting the number of storable items.
parse_names() and reftable_buf_add() avoid leaking by restoring the
original pointer value on failure, but all other callers seem to be OK
with losing the old allocation. Add a new variant of the macro,
REFTABLE_ALLOC_GROW_OR_NULL, which plugs the leak and zeros the
allocation counter. Use it for those callers.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Let's wait for git-gui, gitk, and possibly po/ and delay the tagging
of the -rc1. Many people are already offline for the end-of-year
holidays and it is a slow week, and 'master' front has too many new
things graduated from 'next' a bit too early for me to feel
comfortable.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git refs migrate" learned to also migrate the reflog data across
backends.
* kn/reflog-migration:
refs: mark invalid refname message for translation
refs: add support for migrating reflogs
refs: allow multiple reflog entries for the same refname
refs: introduce the `ref_transaction_update_reflog` function
refs: add `committer_info` to `ref_transaction_add_update()`
refs: extract out refname verification in transactions
refs/files: add count field to ref_lock
refs: add `index` field to `struct ref_udpate`
refs: include committer info in `ref_update` struct
A topic to optionally build with meson, which has graduated to
'master' recently, broke Documentation pipeline with asciidoctor
for the normal Makefile build as well as meson-based one, which
have been corrected.
* ma/asciidoctor-build-fixes:
asciidoctor-extensions.rb.in: inject GIT_DATE
asciidoctor-extensions.rb.in: add missing word
asciidoctor-extensions.rb.in: delete existing <refmiscinfo/>
A topic to optionally build with meson, which has graduated to
'master' recently, has regressed the normal Makefile build, which
is being corrected.
* ps/build-hotfix:
meson: add options to override build information
GIT-VERSION-GEN: fix overriding GIT_BUILT_FROM_COMMIT and GIT_DATE
GIT-VERSION-GEN: fix overriding GIT_VERSION
Makefile: introduce template for GIT-VERSION-GEN
Makefile: drop unneeded indirection for GIT-VERSION-GEN outputs
Makefile: stop including "GIT-VERSION-FILE" in docs
The meson-build procedure is integrated into CI to catch and
prevent bitrotting.
* ps/ci-meson:
ci: wire up Meson builds
t: introduce compatibility options to clar-based tests
t: fix out-of-tree tests for some git-p4 tests
Makefile: detect missing Meson tests
meson: detect missing tests at configure time
t/unit-tests: rename clar-based unit tests to have a common prefix
Makefile: drop -DSUPPRESS_ANNOTATED_LEAKS
ci/lib: support custom output directories when creating test artifacts
Code to reuse objects based on bitmap contents have been tightened
to avoid race condition even when multiple packs are involved.
* tb/bitmap-fix-pack-reuse:
pack-bitmap.c: ensure pack validity for all reuse packs
meson-based build still tried to build and install gitweb even when
Perl is disabled, which has been corrected.
* ps/build-meson-gitweb:
meson: skip gitweb build when Perl is disabled
"git range-diff" learned to optionally show and compare merge
commits in the ranges being compared, with the --diff-merges
option.
* js/range-diff-diff-merges:
range-diff: introduce the convenience option `--remerge-diff`
range-diff: optionally include merge commits' diffs in the analysis
Update the way rename() emulation on Windows handle directories to
correct an earlier attempt to do the same.
* js/mingw-rename-fix:
mingw_rename: do support directory renames
Revert recent changes to the way windows environment is set up for
GitHub CI.
* js/github-windows-setup-fix:
GitHub ci(windows): speed up initializing Git for Windows' minimal SDK again
Build fixes for Windows.
* js/ps-build-cmake-fixup:
cmake/vcxproj: stop special-casing `remote-ext`
cmake: put the Perl modules into the correct location again
cmake: use the correct file name for the Perl header
cmake(mergetools): better support for out-of-tree builds
cmake: better support for out-of-tree builds follow-up
Regression fix for 'show-index' when run outside of a repository.
* as/show-index-uninitialized-hash:
t5300: add test for 'show-index --object-format'
show-index: fix uninitialized hash function
Start working to make the codebase buildable with -Wsign-compare.
* ps/build-sign-compare:
t/helper: don't depend on implicit wraparound
scalar: address -Wsign-compare warnings
builtin/patch-id: fix type of `get_one_patchid()`
builtin/blame: fix type of `length` variable when emitting object ID
gpg-interface: address -Wsign-comparison warnings
daemon: fix type of `max_connections`
daemon: fix loops that have mismatching integer types
global: trivial conversions to fix `-Wsign-compare` warnings
pkt-line: fix -Wsign-compare warning on 32 bit platform
csum-file: fix -Wsign-compare warning on 32-bit platform
diff.h: fix index used to loop through unsigned integer
config.mak.dev: drop `-Wno-sign-compare`
global: mark code units that generate warnings with `-Wsign-compare`
compat/win32: fix -Wsign-compare warning in "wWinMain()"
compat/regex: explicitly ignore "-Wsign-compare" warnings
git-compat-util: introduce macros to disable "-Wsign-compare" warnings
Reftable backend adds check for upper limit of log's update_index.
* kn/reftable-writer-log-write-verify:
reftable/writer: ensure valid range for log's update_index
GitLab CI updates.
* ps/ci-gitlab-update:
ci/lib: fix "CI setup" sections with GitLab CI
ci/lib: do not interpret escape sequences in `group ()` arguments
ci/lib: remove duplicate trap to end "CI setup" group
gitlab-ci: update macOS images to Sonoma
Recent reftable updates mistook a NULL return from a request for
0-byte allocation as OOM and died unnecessarily, which has been
corrected.
* ps/reftable-alloc-failures-zalloc-fix:
reftable/basics: return NULL on zero-sized allocations
reftable/stack: fix zero-sized allocation when there are no readers
reftable/merged: fix zero-sized allocation when there are no readers
reftable/stack: don't perform auto-compaction with less than two tables
In the preceding commits we have fixed a couple of issues when
allocating zero-sized objects. These issues were masked by
implementation-defined behaviour. Quoting malloc(3p):
If size is 0, either:
* A null pointer shall be returned and errno may be set to an
implementation-defined value, or
* A pointer to the allocated space shall be returned. The
application shall ensure that the pointer is not used to access an
object.
So it is perfectly valid that implementations of this function may or
may not return a NULL pointer in such a case.
Adapt both `reftable_malloc()` and `reftable_realloc()` so that they
return NULL pointers on zero-sized allocations. This should remove any
implementation-defined behaviour in our allocators and thus allows us to
detect such platform-specific issues more easily going forward.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar as the preceding commit, we may try to do a zero-sized
allocation when reloading a reftable stack that ain't got any tables.
It is implementation-defined whether malloc(3p) returns a NULL pointer
in that case or a zero-sized object. In case it does return a NULL
pointer though it causes us to think we have run into an out-of-memory
situation, and thus we return an error.
Fix this by only allocating arrays when they have at least one entry.
Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It was reported [1] that Git started to fail with an out-of-memory error
when initializing repositories with the reftable backend on NonStop
platforms. A bisect led to 802c0646ac (reftable/merged: handle
allocation failures in `merged_table_init_iter()`, 2024-10-02), which
changed how we allocate memory when initializing a merged table.
The root cause of this seems to be that NonStop returns a `NULL` pointer
when doing a zero-sized allocation. This would've already happened
before the above change, but we never noticed because we did not check
the result. Now we do notice and thus return an out-of-memory error to
the caller.
Fix the issue by skipping the allocation altogether in case there are no
readers.
[1]: <00ad01db5017$aa9ce340$ffd6a9c0$@nexbridge.com>
Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to compact tables we need at least two tables. Bail out early
from `reftable_stack_auto_compact()` in case we have less than two
tables.
In the original, `stack_table_sizes_for_compaction()` yields an array
that has the same length as the number of tables. This array is then
passed on to `suggest_compaction_segment()`, which returns an empty
segment in case we have less than two tables. The segment is then passed
to `segment_size()`, which will return `0` because both start and end of
the segment are `0`. And because we only call `stack_compact_range()` in
case we have a positive segment size we don't perform auto-compaction at
all. Consequently, this change does not result in a user-visible change
in behaviour when called with a single table.
But when called with no tables this protects us against a potential
out-of-memory error: `stack_table_sizes_for_compaction()` would try to
allocate a zero-byte object when there aren't any tables, and that may
lead to a `NULL` pointer on some platforms like NonStop which causes us
to bail out with an out-of-memory error.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After a38edab7c8 (Makefile: generate doc versions via GIT-VERSION-GEN,
2024-12-06), we no longer inject GIT_DATE when building with
Asciidoctor.
Replace the <date/> tag in the XML to inject the value of GIT_DATE.
Unlike <refmiscinfo/> as handled in a recent commit, we have no reason
to expect that this tag might be missing, so there's no need for "maybe
remove, then add" and we can just outright replace the one that
Asciidoctor has generated based on the mtime of the source file.
Compared to pre-a38edab7c8, we now end up injecting this also in the
build of Git.3pm, which until now has been using the mtime of Git.pm.
That is arguably even a good change since it results in more
reproducible builds.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit a38edab7c8 (Makefile: generate doc versions via GIT-VERSION-GEN,
2024-12-06) stopped providing an attribute value "Git $(GIT_VERSION)" to
asciidoc/Asciidoctor over the command line. Instead, we now provide the
attribute to asciidoc through a generated asciidoc.conf, where the value
is generated as "Git @GIT_VERSION@".
In the similar mechanism for Asciidoctor, we forgot the "Git" prefix.
Restore it.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After the recent a38edab7c8 (Makefile: generate doc versions via
GIT-VERSION-GEN, 2024-12-06), building with Asciidoctor results in
manpages where the headers no longer contain "Git Manual" and the
footers no longer identify the built Git version.
Before a38edab7c8, we used to just provide a few attributes to
Asciidoctor (and asciidoc). Commit 7a30134358 (asciidoctor-extensions:
provide `<refmiscinfo/>`, 2019-09-16) noted that older versions of
Asciidoctor didn't propagate those attributes into the built XML files,
so we started injecting them ourselves from this script. With newer
versions of Asciidoctor, we'd end up with some harmless duplication
among the tags in the final XML.
Post-a38edab7c8, we don't provide these attributes and Asciidoctor
inserts empty-ish values. After our additions from 7a30134358, we get
<refmiscinfo class="source"> </refmiscinfo>
<refmiscinfo class="manual"> </refmiscinfo>
<refmiscinfo class="source">2.47.1.[...]</refmiscinfo>
<refmiscinfo class="manual">Git Manual</refmiscinfo>
When these are handled, it appears to be first come first served,
meaning that our additions have no effect and we regress as described in
the first paragraph.
Remove existing "source" or "manual" <refmiscinfo/> tags before adding
ours. I considered removing all <refmiscinfo/> to get a nice clean
slate, instead of just those two that we want to replace to be a bit
more precise. I opted for the latter. Maybe one day, Asciidoctor learns
to insert something useful there which `xmlto` can pick up and make good
use of -- let's not interfere.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ps/build-hotfix:
meson: add options to override build information
GIT-VERSION-GEN: fix overriding GIT_BUILT_FROM_COMMIT and GIT_DATE
GIT-VERSION-GEN: fix overriding GIT_VERSION
Makefile: introduce template for GIT-VERSION-GEN
Makefile: drop unneeded indirection for GIT-VERSION-GEN outputs
Makefile: stop including "GIT-VERSION-FILE" in docs
We inject various different kinds of build information into build
artifacts, like the version string or the commit from which Git was
built. Add options to let users explicitly override this information
with Meson.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Same as with the preceding commit, neither GIT_BUILT_FROM_COMMIT nor
GIT_DATE can be overridden via the environment. Especially the latter is
of importance given that we set it in our own "Documentation/doc-diff"
script.
Make the values of both variables overridable. Luckily we don't pull in
these values via any included Makefiles, so the fix is trivial compared
to the fix for GIT_VERSON.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
GIT-VERSION-GEN tries to derive the version that Git is being built from
via multiple different sources in the following order:
1. A file called "version" in the source tree's root directory, if it
exists.
2. The current commit in case Git is built from a Git repository.
3. Otherwise, we use a fallback version stored in a variable which is
bumped whenever a new Git version is getting tagged.
It used to be possible to override the version by overriding the
`GIT_VERSION` Makefile variable (e.g. `make GIT_VERSION=foo`). This
worked somewhat by chance, only: `GIT-VERSION-GEN` would write the
actual Git version into `GIT-VERSION-FILE`, not the overridden value,
but when including the file into our Makefile we would not override the
`GIT_VERSION` variable because it has already been set by the user. And
because our Makefile used the variable to propagate the version to our
build tools instead of using `GIT-VERSION-FILE` the resulting build
artifacts used the overridden version.
But that subtle mechanism broke with 4838deab65 (Makefile: refactor
GIT-VERSION-GEN to be reusable, 2024-12-06) and subsequent commits
because the version information is not propagated via the Makefile
variable anymore, but instead via the files that `GIT-VERSION-GEN`
started to write. And as the script never knew about the `GIT_VERSION`
environment variable in the first place it uses one of the values listed
above instead of the overridden value.
Fix this issue by making `GIT-VERSION-GEN` handle the case where
`GIT_VERSION` has been set via the environment.
Note that this requires us to introduce a new GIT_VERSION_OVERRIDE
variable that stores a potential user-provided value, either via the
environment or via "config.mak". Ideally we wouldn't need it and could
just continue to use GIT_VERSION for this. But unfortunately, Makefiles
will first include all sub-Makefiles before figuring out whether it
needs to re-make any of them [1]. Consequently, if there already is a
GIT-VERSION-FILE, we would have slurped in its value of GIT_VERSION
before we call GIT-VERSION-GEN, and because GIT-VERSION-GEN now uses
that value as an override it would mean that the first generated value
for GIT_VERSION will remain unchanged.
Furthermore we have to move the include for "GIT-VERSION-FILE" after the
includes for "config.mak" and related so that GIT_VERSION_OVERRIDE can
be set to the value provided by "config.mak".
[1]: https://www.gnu.org/software/make/manual/html_node/Remaking-Makefiles.html
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new template to call GIT-VERSION-GEN. This will allow us to
iterate on how exactly the script is called in subsequent commits
without having to adapt all call sites every time.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some of the callsites of GIT-VERSION-GEN generate the target file with a
"+" suffix first and then move the file into place when the new contents
are different compared to the old contents. This allows us to avoid a
needless rebuild by not updating timestamps of the target file when its
contents will remain unchanged anyway.
In fact though, this exact logic is already handled in GIT-VERSION-GEN,
so doing this manually is pointless. This is a leftover from an earlier
version of 4838deab65 (Makefile: refactor GIT-VERSION-GEN to be
reusable, 2024-12-06), where the script didn't handle that logic for us.
Drop the needless indirection.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We include "GIT-VERSION-FILE" in our docs Makefile, but don't actually
use the "GIT_VERSION" variable that it provides. This is a leftover from
the conversion to make "GIT-VERSION-GEN" generate version information
in-place by substituting placeholders in 4838deab65 (Makefile: refactor
GIT-VERSION-GEN to be reusable, 2024-12-06) and subsequent commits,
where all usages of the variable were removed.
Stop including the file.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is possible to configure a Git build without Perl when disabling both
our test suite and all Perl-based features. In Meson, this can be
achieved with `meson setup -Dperl=disabled -Dtests=false`.
It was reported by a user that this breaks the Meson build because
gitweb gets built even if Perl was not discovered in such a build:
$ meson setup .. -Dtests=false -Dperl=disabled
...
../gitweb/meson.build:2:43: ERROR: Unable to get the path of a not-found external program
Fix this issue by introducing a new feature-option that allows the user
to configure whether or not to build Gitweb. The feature is set to
'auto' by default and will be disabled automatically in case Perl was
not found on the system.
Reported-by: Daniel Engberg <daniel.engberg.lists@pyret.net>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The error message produced by `transaction_refname_valid()` changes based
on whether the update is a ref update or a reflog update, with the use
of a ternary operator. This breaks translation since the sub-msg is not
marked for translation. Fix this by setting the entire message using a
`if {} else {}` block and marking each message for translation.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The alloc and nr fields of a prio-queue tell us how much memory is
allocated and used in the array. So the natural type for them is size_t,
which prevents overflow on 64-bit systems where "int" is still 32 bits.
This is unlikely to happen in practice, as we typically use it for
storing commits, and having 2^31 of those is rather a lot. But it's good
to keep our generic data structures as flexible as possible. And as we
start to enforce -Wsign-compare, it means that callers need to use
"int", too, and the problem proliferates. Let's fix it at the source.
The changes here can be put into a few groups:
1. Changing the alloc/nr fields in the struct to size_t. This requires
swapping out int for size_t in negotiator/skipping.c, as well as
in prio_queue_get(), because those all iterate over the array.
Building with -Wsign-compare complains about these.
2. Other code that assigns or passes around indexes into the array
(e.g., the swap() and compare() functions) won't trigger
-Wsign-compare because we are simply truncating the values. These
are caught by -Wconversion, but I've adjusted them here to
future-proof us.
3. In prio_queue_reverse() we compute "queue->nr - 1" without checking
if anything is in the queue, which underflows now that nr is
unsigned. We can fix that by returning early when the queue is
empty (there is nothing to reverse).
4. The insertion_ctr variable is currently unsigned, but can likewise
grow (it is actually worse, because adding and removing an element
many times will keep increasing the counter, even though "nr" does
not). I've bumped that to size_t here, as well.
But -Wconversion notes that computing the "cmp" result by
subtracting the counters and assigning to "int" is a potential
problem. And that's true even before this patch, since we use an
unsigned counter (imagine comparing "2^32-1" and "0", which should
be a high positive value, but instead is "-1" as a signed int).
Since we only care about the sign (and not the magnitude) of the
result, we could fix this by swapping out the subtraction for a
ternary comparison. Probably the performance impact would be
negligible, since we just called into a custom compare function and
branched on its result anyway. But it's easy enough to do a
branchless version by subtracting the comparison results.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git bundle create" with an annotated tag on the positive end of
the revision range had a workaround code for older limitation in
the revision walker, which has become unnecessary.
* tc/bundle-with-tag-remove-workaround:
bundle: remove unneeded code
"git fetch" honors "remote.<remote>.followRemoteHEAD" settings to
tweak the remote-tracking HEAD in "refs/remotes/<remote>/HEAD".
* bf/fetch-set-head-config:
remote set-head: set followRemoteHEAD to "warn" if "always"
fetch set_head: add warn-if-not-$branch option
fetch set_head: move warn advice into advise_if_enabled
fetch: add configuration for set_head behaviour
"git fetch" from a configured remote learned to update a missing
remote-tracking HEAD but it asked the remote about their HEAD even
when it did not need to, which has been corrected. Incidentally,
this also corrects "git fetch --tags $URL" which was broken by the
new feature in an unspecified way.
* jc/set-head-symref-fix:
fetch: do not ask for HEAD unnecessarily
When "git fetch $remote" notices that refs/remotes/$remote/HEAD is
missing and discovers what branch the other side points with its
HEAD, refs/remotes/$remote/HEAD is updated to point to it.
* bf/set-head-symref:
fetch set_head: handle mirrored bare repositories
fetch: set remote/HEAD if it does not exist
refs: add create_only option to refs_update_symref_extended
refs: add TRANSACTION_CREATE_EXISTS error
remote set-head: better output for --auto
remote set-head: refactor for readability
refs: atomically record overwritten ref in update_symref
refs: standardize output of refs_read_symbolic_ref
t/t5505-remote: test failure of set-head
t/t5505-remote: set default branch to main
Commit 44f9fd6496 (pack-bitmap.c: check preferred pack validity when
opening MIDX bitmap, 2022-05-24) prevents a race condition whereby the
preferred pack disappears between opening the MIDX bitmap and attempting
verbatim reuse out of its packs.
That commit forces open_midx_bitmap_1() to ensure the validity of the
MIDX's preferred pack, meaning that we have an open file handle on the
*.pack, ensuring that we can reuse bytes out of verbatim later on in the
process[^1].
But 44f9fd6496 was not extended to cover multi-pack reuse, meaning that
this same race condition exists for non-preferred packs during verbatim
reuse. Work around that race in the same way by only marking valid packs
as reuse-able. For packs that aren't reusable, skip over them but
include the number of objects they have to ensure we allocate a large
enough 'reuse' bitmap (e.g. if a pack in the middle of the MIDX
disappeared but we still want to reuse later packs).
Since we're ensuring the validity of these packs within the verbatim
reuse code, we no longer have to special-case the preferred pack and
open it within the open_midx_bitmap_1() function.
An alternative approach to the one taken here would be to open all
MIDX'd packs from within open_midx_bitmap_1(). But that would be both
slower and make the bitmaps less useful, since we can still perform some
pack reuse among the packs that still exist when the *.bitmap is opened.
After applying this patch, we can simulate the new behavior after
instrumenting Git like so:
diff --git a/packfile.c b/packfile.c
index 9560f0a33c..aedce72524 100644
--- a/packfile.c
+++ b/packfile.c
@@ -557,6 +557,11 @@ static int open_packed_git_1(struct packed_git *p)
; /* nothing */
p->pack_fd = git_open(p->pack_name);
+ {
+ const char *delete = getenv("GIT_RACILY_DELETE");
+ if (delete && !strcmp(delete, pack_basename(p)))
+ return -1;
+ }
if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
return -1;
pack_open_fds++;
and adding the following test:
test_expect_success 'disappearing packs' '
git init disappearing-packs &&
(
cd disappearing-packs &&
git config pack.allowPackReuse multi &&
test_commit A &&
test_commit B &&
test_commit C &&
A="$(echo "A" | git pack-objects --revs $packdir/pack-A)" &&
B="$(echo "A..B" | git pack-objects --revs $packdir/pack-B)" &&
C="$(echo "B..C" | git pack-objects --revs $packdir/pack-C)" &&
git multi-pack-index write --bitmap --preferred-pack=pack-A-$A.idx &&
test_pack_objects_reused_all 9 3 &&
test_env GIT_RACILY_DELETE=pack-A-$A.pack \
test_pack_objects_reused_all 6 2 &&
test_env GIT_RACILY_DELETE=pack-B-$B.pack \
test_pack_objects_reused_all 6 2 &&
test_env GIT_RACILY_DELETE=pack-C-$C.pack \
test_pack_objects_reused_all 6 2
)
'
Note that we could relax the single-pack version of this which was most
recently addressed in dc1daacdcc (pack-bitmap: check pack validity when
opening bitmap, 2021-07-23), but only partially. Because we still need
to know the object count in the pack, we'd still have to open the pack's
*.idx, so the savings there are marginal.
Note likewise that we add a new "if (!packs_nr)" early return in the
pack reuse code to avoid a potentially expensive allocation on the
'reuse' bitmap in the case that no packs are available for reuse.
[^1]: Unless we run out of open file handles. If that happens and we are
forced to close the only open file handle of a file that has been
removed from underneath us, there is nothing we can do.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
