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72071 commits

Author SHA1 Message Date
Junio C Hamano a54a84b333 The sixth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 14:05:24 -08:00
Junio C Hamano bdfa7a2445 Merge branch 'rs/mem-pool-improvements'
MemPool allocator fixes.

* rs/mem-pool-improvements:
  mem-pool: simplify alignment calculation
  mem-pool: fix big allocations
2024-01-08 14:05:17 -08:00
Junio C Hamano 8a48cd484f Merge branch 'rs/fast-import-simplify-mempool-allocation'
Code simplification.

* rs/fast-import-simplify-mempool-allocation:
  fast-import: use mem_pool_calloc()
2024-01-08 14:05:16 -08:00
Junio C Hamano d73db002b5 Merge branch 'en/sparse-checkout-eoo'
"git sparse-checkout (add|set) --[no-]cone --end-of-options" did
not handle "--end-of-options" correctly after a recent update.

* en/sparse-checkout-eoo:
  sparse-checkout: be consistent with end of options markers
2024-01-08 14:05:16 -08:00
Junio C Hamano 863c596e68 Merge branch 'jc/sparse-checkout-set-default-fix'
"git sparse-checkout set" added default patterns even when the
patterns are being fed from the standard input, which has been
corrected.

* jc/sparse-checkout-set-default-fix:
  sparse-checkout: use default patterns for 'set' only !stdin
2024-01-08 14:05:16 -08:00
Junio C Hamano 492ee03f60 Merge branch 'en/header-cleanup'
Remove unused header "#include".

* en/header-cleanup:
  treewide: remove unnecessary includes in source files
  treewide: add direct includes currently only pulled in transitively
  trace2/tr2_tls.h: remove unnecessary include
  submodule-config.h: remove unnecessary include
  pkt-line.h: remove unnecessary include
  line-log.h: remove unnecessary include
  http.h: remove unnecessary include
  fsmonitor--daemon.h: remove unnecessary includes
  blame.h: remove unnecessary includes
  archive.h: remove unnecessary include
  treewide: remove unnecessary includes in source files
  treewide: remove unnecessary includes from header files
2024-01-08 14:05:15 -08:00
Junio C Hamano 9decd56cc9 Merge branch 'ml/doc-merge-updates'
Doc update.

* ml/doc-merge-updates:
  Documentation/git-merge.txt: use backticks for command wrapping
  Documentation/git-merge.txt: fix reference to synopsis
2024-01-08 14:05:15 -08:00
Junio C Hamano 6bf317df4b Merge branch 'jc/archive-list-with-extra-args'
"git archive --list extra garbage" silently ignored excess command
line parameters, which has been corrected.

* jc/archive-list-with-extra-args:
  archive: "--list" does not take further options
2024-01-08 14:05:14 -08:00
Tamino Bauknecht 39487a1510 fetch: add new config option fetch.all
Introduce a boolean configuration option fetch.all which allows to
fetch all available remotes by default. The config option can be
overridden by explicitly specifying a remote or by using --no-all.
The behavior for --all is unchanged and calling git-fetch with --all
and a remote will still result in an error.

Additionally, describe the configuration variable in the config
documentation and implement new tests to cover the expected behavior.
Also add --no-all to the command-line documentation of git-fetch.

Signed-off-by: Tamino Bauknecht <dev@tb6.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 13:36:23 -08:00
Patrick Steinhardt 8f4c00de95 builtin/worktree: create refdb via ref backend
When creating a worktree we create the worktree's ref database manually
by first writing a "HEAD" file so that the directory is recognized as a
Git repository by other commands, and then running git-update-ref(1) or
git-symbolic-ref(1) to write the actual value. But while this is fine
for the files backend, this logic simply assumes too much about how the
ref backend works and will leave behind an invalid ref database once any
other ref backend lands.

Refactor the code to instead use `refs_init_db()` to initialize the ref
database so that git-worktree(1) itself does not need to know about how
to initialize it. This will allow future ref backends to customize how
the per-worktree ref database is set up. Furthermore, as we now already
have a worktree ref store around, we can also avoid spawning external
commands to write the HEAD reference and instead use the refs API to do
so.

Note that we do not have an equivalent to passing the `--quiet` flag to
git-symbolic-ref(1) as we did before. This flag does not have an effect
anyway though, as git-symbolic-ref(1) only honors it when reading a
symref, but never when writing one.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 13:17:30 -08:00
Patrick Steinhardt b8a846b2e0 worktree: expose interface to look up worktree by name
Our worktree interfaces do not provide a way to look up a worktree by
its name. Expose `get_linked_worktree()` to allow for this usecase. As
callers are responsible for freeing this worktree, introduce a new
function `free_worktree()` that does so.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 13:17:30 -08:00
Patrick Steinhardt 84f0ea956f builtin/worktree: move setup of commondir file earlier
Shuffle around how we create supporting worktree files so that we first
ensure that the worktree has all link files ("gitdir", "commondir")
before we try to initialize the ref database by writing "HEAD". This
will be required by a subsequent commit where we start to initialize the
ref database via `refs_init_db()`, which will require an initialized
`struct worktree *`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 13:17:30 -08:00
Patrick Steinhardt 2eb1d0c452 refs/files: skip creation of "refs/{heads,tags}" for worktrees
The files ref backend will create both "refs/heads" and "refs/tags" in
the Git directory. While this logic makes sense for normal repositories,
it does not for worktrees because those refs are "common" refs that
would always be contained in the main repository's ref database.

Introduce a new flag telling the backend that it is expected to create a
per-worktree ref database and skip creation of these dirs in the files
backend when the flag is set. No other backends (currently) need
worktree-specific logic, so this is the only required change to start
creating per-worktree ref databases via `refs_init_db()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 13:17:30 -08:00
Patrick Steinhardt c358d165f2 setup: move creation of "refs/" into the files backend
When creating the ref database we unconditionally create the "refs/"
directory in "setup.c". This is a mandatory prerequisite for all Git
repositories regardless of the ref backend in use, because Git will be
unable to detect the directory as a repository if "refs/" doesn't exist.

We are about to add another new caller that will want to create a ref
database when creating worktrees. We would require the same logic to
create the "refs/" directory even though the caller really should not
care about such low-level details. Ideally, the ref database should be
fully initialized after calling `refs_init_db()`.

Move the code to create the directory into the files backend itself to
make it so. This means that future ref backends will also need to have
equivalent logic around to ensure that the directory exists, but it
seems a lot more sensible to have it this way round than to require
callers to create the directory themselves.

An alternative to this would be to create "refs/" in `refs_init_db()`
directly. This feels conceptually unclean though as the creation of the
refdb is now cluttered across different callsites. Furthermore, both the
"files" and the upcoming "reftable" backend write backend-specific data
into the "refs/" directory anyway, so splitting up this logic would only
make it harder to reason about.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 13:17:30 -08:00
Patrick Steinhardt 2e573d61ff refs: prepare refs_init_db() for initializing worktree refs
The purpose of `refs_init_db()` is to initialize the on-disk files of a
new ref database. The function is quite inflexible right now though, as
callers can neither specify the `struct ref_store` nor can they pass any
flags.

Refactor the interface to accept both of these. This will be required so
that we can start initializing per-worktree ref databases via the ref
backend instead of open-coding the initialization in "worktree.c".

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 13:17:30 -08:00
Junio C Hamano 5bf20d6c77 Merge branch 'ps/refstorage-extension' into ps/worktree-refdb-initialization
* ps/refstorage-extension:
  t9500: write "extensions.refstorage" into config
  builtin/clone: introduce `--ref-format=` value flag
  builtin/init: introduce `--ref-format=` value flag
  builtin/rev-parse: introduce `--show-ref-format` flag
  t: introduce GIT_TEST_DEFAULT_REF_FORMAT envvar
  setup: introduce GIT_DEFAULT_REF_FORMAT envvar
  setup: introduce "extensions.refStorage" extension
  setup: set repository's formats on init
  setup: start tracking ref storage format
  refs: refactor logic to look up storage backends
  worktree: skip reading HEAD when repairing worktrees
  t: introduce DEFAULT_REPO_FORMAT prereq
  builtin/clone: create the refdb with the correct object format
  builtin/clone: skip reading HEAD when retrieving remote
  builtin/clone: set up sparse checkout later
  builtin/clone: fix bundle URIs with mismatching object formats
  remote-curl: rediscover repository when fetching refs
  setup: allow skipping creation of the refdb
  setup: extract function to create the refdb
2024-01-08 12:58:54 -08:00
Patrick Steinhardt cd69c635a1 ci: add job performing static analysis on GitLab CI
Our GitHub Workflows definitions have a static analysis job that
runs the following tasks:

  - Coccinelle to check for suggested refactorings.

  - `make hdr-check` to check for missing includes or forward
    declarations in our header files.

  - `make check-pot` to check our translations for issues.

  - `./ci/check-directional-formatting.bash` to check whether our
    sources contain any Unicode directional formatting code points.

Add an equivalent job to our GitLab CI definitions.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 11:23:03 -08:00
Patrick Steinhardt fc134b41ce git-prompt: stop manually parsing HEAD with unknown ref formats
We're manually parsing the HEAD reference in git-prompt to figure out
whether it is a symbolic or direct reference. This makes it intimately
tied to the on-disk format we use to store references and will stop
working once we gain additional reference backends in the Git project.

Ideally, we would refactor the code to exclusively use plumbing tools to
read refs such that we do not have to care about the on-disk format at
all. Unfortunately though, spawning processes can be quite expensive on
some systems like Windows. As the Git prompt logic may be executed quite
frequently we try very hard to spawn as few processes as possible. This
refactoring is thus out of question for now.

Instead, condition the logic on the repository's ref format: if the repo
uses the the "files" backend we can continue to use the old logic and
read the respective files from disk directly. If it's anything else,
then we use git-symbolic-ref(1) to read the value of HEAD.

This change makes the Git prompt compatible with the upcoming "reftable"
format.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 11:21:45 -08:00
Junio C Hamano 4081d45d7f Merge branch 'ps/refstorage-extension' into ps/prompt-parse-HEAD-futureproof
* ps/refstorage-extension:
  t9500: write "extensions.refstorage" into config
  builtin/clone: introduce `--ref-format=` value flag
  builtin/init: introduce `--ref-format=` value flag
  builtin/rev-parse: introduce `--show-ref-format` flag
  t: introduce GIT_TEST_DEFAULT_REF_FORMAT envvar
  setup: introduce GIT_DEFAULT_REF_FORMAT envvar
  setup: introduce "extensions.refStorage" extension
  setup: set repository's formats on init
  setup: start tracking ref storage format
  refs: refactor logic to look up storage backends
  worktree: skip reading HEAD when repairing worktrees
  t: introduce DEFAULT_REPO_FORMAT prereq
2024-01-08 11:21:18 -08:00
Rubén Justo 5aea3955bc branch: clarify <oldbranch> term
Since 52d59cc645 (branch: add a --copy (-c) option to go with --move
(-m), 2017-06-18) <oldbranch> is used in more operations than just -m.

Let's also clarify what we do if <oldbranch> is omitted.

Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-08 10:06:05 -08:00
Illia Bobyr 25aec06326 rebase: clarify --reschedule-failed-exec default
Documentation should mention the default behavior.

It is better to explain the persistent nature of the
--reschedule-failed-exec flag from the user standpoint, rather than from
the implementation standpoint.

Signed-off-by: Illia Bobyr <illia.bobyr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-05 09:41:25 -08:00
Jeff King 993d38a066 index-pack: spawn threads atomically
The t5309 script triggers a racy false positive with SANITIZE=leak on a
multi-core system. Running with "--stress --run=6" usually fails within
10 seconds or so for me, complaining with something like:

    + git index-pack --fix-thin --stdin
    fatal: REF_DELTA at offset 46 already resolved (duplicate base 01d7713666f4de822776c7622c10f1b07de280dc?)

    =================================================================
    ==3904583==ERROR: LeakSanitizer: detected memory leaks

    Direct leak of 32 byte(s) in 1 object(s) allocated from:
        #0 0x7fa790d01986 in __interceptor_realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98
        #1 0x7fa790add769 in __pthread_getattr_np nptl/pthread_getattr_np.c:180
        #2 0x7fa790d117c5 in __sanitizer::GetThreadStackTopAndBottom(bool, unsigned long*, unsigned long*) ../../../../src/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp:150
        #3 0x7fa790d11957 in __sanitizer::GetThreadStackAndTls(bool, unsigned long*, unsigned long*, unsigned long*, unsigned long*) ../../../../src/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp:598
        #4 0x7fa790d03fe8 in __lsan::ThreadStart(unsigned int, unsigned long long, __sanitizer::ThreadType) ../../../../src/libsanitizer/lsan/lsan_posix.cpp:51
        #5 0x7fa790d013fd in __lsan_thread_start_func ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:440
        #6 0x7fa790adc3eb in start_thread nptl/pthread_create.c:444
        #7 0x7fa790b5ca5b in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

    SUMMARY: LeakSanitizer: 32 byte(s) leaked in 1 allocation(s).
    Aborted

What happens is this:

  0. We construct a bogus pack with a duplicate object in it and trigger
     index-pack.

  1. We spawn a bunch of worker threads to resolve deltas (on my system
     it is 16 threads).

  2. One of the threads sees the duplicate object and bails by calling
     exit(), taking down all of the threads. This is expected and is the
     point of the test.

  3. At the time exit() is called, we may still be spawning threads from
     the main process via pthread_create(). LSan hooks thread creation
     to update its book-keeping; it has to know where each thread's
     stack is (so it can find entry points for reachable memory). So it
     calls pthread_getattr_np() to get information about the new thread.
     That may allocate memory that must be freed with a matching call to
     pthread_attr_destroy(). Probably LSan does that immediately, but
     if you're unlucky enough, the exit() will happen while it's between
     those two calls, and the allocated pthread_attr_t appears as a
     leak.

This isn't a real leak. It's not even in our code, but rather in the
LSan instrumentation code. So we could just ignore it. But the false
positive can cause people to waste time tracking it down.

It's possibly something that LSan could protect against (e.g., cover the
getattr/destroy pair with a mutex, and then in the final post-exit()
check for leaks try to take the same mutex). But I don't know enough
about LSan to say if that's a reasonable approach or not (or if my
analysis is even completely correct).

In the meantime, it's pretty easy to avoid the race by making creation
of the worker threads "atomic". That is, we'll spawn all of them before
letting any of them start to work. That's easy to do because we already
have a work_lock() mutex for handing out that work. If the main process
takes it, then all of the threads will immediately block until we've
finished spawning and released it.

This shouldn't make any practical difference for non-LSan runs. The
thread spawning is quick, and could happen before any worker thread gets
scheduled anyway.

Probably other spots that use threads are subject to the same issues.
But since we have to manually insert locking (and since this really is
kind of a hack), let's not bother with them unless somebody experiences
a similar racy false-positive in practice.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-05 08:40:56 -08:00
Jeff King d70f554cdf commit-graph: retain commit slab when closing NULL commit_graph
This fixes a regression introduced in ac6d45d11f (commit-graph: move
slab-clearing to close_commit_graph(), 2023-10-03), in which running:

  git -c fetch.writeCommitGraph=true fetch --recurse-submodules

multiple times in a freshly cloned repository causes a segfault. What
happens in the second (and subsequent) runs is this:

  1. We make a "struct commit" for any ref tips which we're storing
     (even if we already have them, they still go into FETCH_HEAD).

     Because the first run will have created a commit graph, we'll find
     those commits in the graph.

     The commit struct is therefore created with a NULL "maybe_tree"
     entry, because we can load its oid from the graph later. But to do
     that we need to remember that we got the commit from the graph,
     which is recorded in a global commit_graph_data_slab object.

  2. Because we're using --recurse-submodules, we'll try to fetch each
     of the possible submodules. That implies creating a separate
     "struct repository" in-process for each submodule, which will
     require a later call to repo_clear().

     The call to repo_clear() calls raw_object_store_clear(), which in
     turn calls close_object_store(), which in turn calls
     close_commit_graph(). And the latter frees the commit graph data
     slab.

  3. Later, when trying to write out a new commit graph, we'll ask for
     their tree oid via get_commit_tree_oid(), which will see that the
     object is parsed but with a NULL maybe_tree field. We'd then
     usually pull it from the graph file, but because the slab was
     cleared, we don't realize that we can do so! We end up returning
     NULL and segfaulting.

     (It seems questionable that we'd write a graph entry for such a
     commit anyway, since we know we already have one. I didn't
     double-check, but that may simply be another side effect of having
     cleared the slab).

The bug is in step (2) above. We should not be clearing the slab when
cleaning up the submodule repository structs. Prior to ac6d45d11f, we
did not do so because it was done inside a helper function that returned
early when it saw NULL. So the behavior change from that commit is that
we'll now _always_ clear the slab via repo_clear(), even if the
repository being closed did not have a commit graph (and thus would have
a NULL commit_graph struct).

The most immediate fix is to add in a NULL check in close_commit_graph(),
making it a true noop when passed in an object_store with a NULL
commit_graph (it's OK to just return early, since the rest of its code
is already a noop when passed NULL). That restores the pre-ac6d45d11f
behavior. And that's what this patch does, along with a test that
exercises it (we already have a test that uses submodules along with
fetch.writeCommitGraph, but the bug only triggers when there is a
subsequent fetch and when that fetch uses --recurse-submodules).

So that fixes the regression in the least-risky way possible.

I do think there's some fragility here that we might want to follow up
on. We have a global commit_graph_data_slab that contains graph
positions, and our global commit structs depend on the that slab
remaining valid. But close_commit_graph() is just about closing _one_
object store's graph. So it's dangerous to call that function and clear
the slab without also throwing away any "struct commit" we might have
parsed that depends on it.

Which at first glance seems like a bug we could already trigger. In the
situation described here, there is no commit graph in the submodule
repository, so our commit graph is NULL (in fact, in our test script
there is no submodule repo at all, so we immediately return from
repo_init() and call repo_clear() only to free up memory). But what
would happen if there was one? Wouldn't we see a non-NULL commit_graph
entry, and then clear the global slab anyway?

The answer is "no", but for very bizarre reasons. Remember that
repo_clear() calls raw_object_store_clear(), which then calls
close_object_store() and thus close_commit_graph(). But before it does
so, raw_object_store_clear() does something else: it frees the commit
graph and sets it to NULL! So by this code path we'll _never_ see a
non-NULL commit_graph struct, and thus never clear the slab.

So it happens to work out. But it still seems questionable to me that we
would clear a global slab (which might still be in use) when closing the
commit graph. This clearing comes from 957ba814bf (commit-graph: when
closing the graph, also release the slab, 2021-09-08), and was fixing a
case where we really did need it to be closed (and in that case we
presumably call close_object_store() more directly).

So I suspect there may still be a bug waiting to happen there, as any
object loaded before the call to close_object_store() may be stranded
with a bogus maybe_tree entry (and thus looking at it after the call
might cause an error). But I'm not sure how to trigger it, nor what the
fix should look like (you probably would need to "unparse" any objects
pulled from the graph). And so this patch punts on that for now in favor
of fixing the recent regression in the most direct way, which should not
have any other fallouts.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-05 08:35:26 -08:00
Chandra Pratap 556e68032f write-or-die: make GIT_FLUSH a Boolean environment variable
Among Git's environment variables, the ones marked as "Boolean"
accept values in a way similar to Boolean configuration variables,
i.e. values like 'yes', 'on', 'true' and positive numbers are
taken as "on" and values like 'no', 'off', 'false' are taken as
"off".

GIT_FLUSH can be used to force Git to use non-buffered I/O when
writing to stdout. It can only accept two values, '1' which causes
Git to flush more often and '0' which makes all output buffered.
Make GIT_FLUSH accept more values besides '0' and '1' by turning it
into a Boolean environment variable, modifying the required logic.
Update the related documentation.

Signed-off-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-04 10:32:21 -08:00
Sam Delmerico ee9895b0ff push: region_leave trace for negotiate_using_fetch
There were two region_enter events for negotiate_using_fetch instead of
one enter and one leave. This commit replaces the second region_enter
event with a region_leave.

Signed-off-by: Sam Delmerico <delmerico@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 15:32:44 -08:00
Maarten van der Schrieck 9cd30af991 Documentation: fix statement about rebase.instructionFormat
Since commit 62db5247 (rebase -i: generate the script via
rebase--helper, 2017-07-14), the short hash is given in
rebase-todo. Specifying rebase.instructionFormat does not alter this
behavior, contrary to what the documentation implies.

Signed-off-by: Maarten van der Schrieck <maarten@thingsconnected.nl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 11:21:15 -08:00
Patrick Steinhardt 19b9496c1f reftable/merged: transfer ownership of records when iterating
When iterating over records with the merged iterator we put the records
into a priority queue before yielding them to the caller. This means
that we need to allocate the contents of these records before we can
pass them over to the caller.

The handover to the caller is quite inefficient though because we first
deallocate the record passed in by the caller and then copy over the new
record, which requires us to reallocate memory.

Refactor the code to instead transfer ownership of the new record to the
caller. So instead of reallocating all contents, we now release the old
record and then copy contents of the new record into place.

The following benchmark of `git show-ref --quiet` in a repository with
around 350k refs shows a clear improvement. Before:

    HEAP SUMMARY:
        in use at exit: 21,163 bytes in 193 blocks
      total heap usage: 708,058 allocs, 707,865 frees, 36,783,255 bytes allocated

After:

    HEAP SUMMARY:
        in use at exit: 21,163 bytes in 193 blocks
      total heap usage: 357,007 allocs, 356,814 frees, 24,193,602 bytes allocated

This shows that we now have roundabout a single allocation per record
that we're yielding from the iterator. Ideally, we'd also get rid of
this allocation so that the number of allocations doesn't scale with the
number of refs anymore. This would require some larger surgery though
because the memory is owned by the priority queue before transferring it
over to the caller.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:54:21 -08:00
Patrick Steinhardt 5473aca376 reftable/merged: really reuse buffers to compute record keys
In 829231dc20 (reftable/merged: reuse buffer to compute record keys,
2023-12-11), we have refactored the merged iterator to reuse a pair of
long-living strbufs by relying on the fact that `reftable_record_key()`
tries to reuse already allocated strbufs by calling `strbuf_reset()`,
which should give us significantly fewer reallocations compared to the
old code that used on-stack strbufs that are allocated for each and
every iteration. Unfortunately, we called `strbuf_release()` on these
long-living strbufs that we meant to reuse on each iteration, defeating
the optimization.

Fix this performance issue by not releasing those buffers on iteration
anymore, where we instead rely on `merged_iter_close()` to release the
buffers for us.

Using `git show-ref --quiet` in a repository with ~350k refs this leads
to a significant drop in allocations. Before:

    HEAP SUMMARY:
        in use at exit: 21,163 bytes in 193 blocks
      total heap usage: 1,410,148 allocs, 1,409,955 frees, 61,976,068 bytes allocated

After:

    HEAP SUMMARY:
        in use at exit: 21,163 bytes in 193 blocks
      total heap usage: 708,058 allocs, 707,865 frees, 36,783,255 bytes allocated

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:54:21 -08:00
Patrick Steinhardt b31e3cc620 reftable/record: store "val2" hashes as static arrays
Similar to the preceding commit, convert ref records of type "val2" to
store their object IDs in static arrays instead of allocating them for
every single record.

We're using the same benchmark as in the preceding commit, with `git
show-ref --quiet` in a repository with ~350k refs. This time around
though the effects aren't this huge. Before:

    HEAP SUMMARY:
        in use at exit: 21,163 bytes in 193 blocks
      total heap usage: 1,419,040 allocs, 1,418,847 frees, 62,153,868 bytes allocated

After:

    HEAP SUMMARY:
        in use at exit: 21,163 bytes in 193 blocks
      total heap usage: 1,410,148 allocs, 1,409,955 frees, 61,976,068 bytes allocated

This is because "val2"-type records are typically only stored for peeled
tags, and the number of annotated tags in the benchmark repository is
rather low. Still, it can be seen that this change leads to a reduction
of allocations overall, even if only a small one.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:54:21 -08:00
Patrick Steinhardt 7af607c58d reftable/record: store "val1" hashes as static arrays
When reading ref records of type "val1", we store its object ID in an
allocated array. This results in an additional allocation for every
single ref record we read, which is rather inefficient especially when
iterating over refs.

Refactor the code to instead use an embedded array of `GIT_MAX_RAWSZ`
bytes. While this means that `struct ref_record` is bigger now, we
typically do not store all refs in an array anyway and instead only
handle a limited number of records at the same point in time.

Using `git show-ref --quiet` in a repository with ~350k refs this leads
to a significant drop in allocations. Before:

    HEAP SUMMARY:
        in use at exit: 21,098 bytes in 192 blocks
      total heap usage: 2,116,683 allocs, 2,116,491 frees, 76,098,060 bytes allocated

After:

    HEAP SUMMARY:
        in use at exit: 21,098 bytes in 192 blocks
      total heap usage: 1,419,031 allocs, 1,418,839 frees, 62,145,036 bytes allocated

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:54:20 -08:00
Patrick Steinhardt 88f59d9e31 reftable/record: constify some parts of the interface
We're about to convert reftable records to stop storing their object IDs
as allocated hashes. Prepare for this refactoring by constifying some
parts of the interface that will be impacted by this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:54:20 -08:00
Patrick Steinhardt ddac965965 reftable/writer: fix index corruption when writing multiple indices
Each reftable may contain multiple types of blocks for refs, objects and
reflog records, where each of these may have an index that makes it more
efficient to find the records. It was observed that the index for log
records can become corrupted under certain circumstances, where the
first entry of the index points into the object index instead of to the
log records.

As it turns out, this corruption can occur whenever we write a log index
as well as at least one additional index. Writing records and their index
is basically a two-step process:

  1. We write all blocks for the corresponding record. Each block that
     gets written is added to a list of blocks to index.

  2. Once all blocks were written we finish the section. If at least two
     blocks have been added to the list of blocks to index then we will
     now write the index for those blocks and flush it, as well.

When we have a very large number of blocks then we may decide to write a
multi-level index, which is why we also keep track of the list of the
index blocks in the same way as we previously kept track of the blocks
to index.

Now when we have finished writing all index blocks we clear the index
and flush the last block to disk. This is done in the wrong order though
because flushing the block to disk will re-add it to the list of blocks
to be indexed. The result is that the next section we are about to write
will have an entry in the list of blocks to index that points to the
last block of the preceding section's index, which will corrupt the log
index.

Fix this corruption by clearing the index after having written the last
block.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:54:20 -08:00
Patrick Steinhardt 75d790608f reftable/stack: do not auto-compact twice in reftable_stack_add()
In 5c086453ff (reftable/stack: perform auto-compaction with
transactional interface, 2023-12-11), we fixed a bug where the
transactional interface to add changes to a reftable stack did not
perform auto-compaction by calling `reftable_stack_auto_compact()` in
`reftable_stack_addition_commit()`. While correct, this change may now
cause us to perform auto-compaction twice in the non-transactional
interface `reftable_stack_add()`:

  - It performs auto-compaction by itself.

  - It now transitively performs auto-compaction via the transactional
    interface.

Remove the first instance so that we only end up doing auto-compaction
once.

Reported-by: Han-Wen Nienhuys <hanwenn@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:54:20 -08:00
Patrick Steinhardt d26c21483d reftable/stack: do not overwrite errors when compacting
In order to compact multiple stacks we iterate through the merged ref
and log records. When there is any error either when reading the records
from the old merged table or when writing the records to the new table
then we break out of the respective loops. When breaking out of the loop
for the ref records though the error code will be overwritten, which may
cause us to inadvertently skip over bad ref records. In the worst case,
this can lead to a compacted stack that is missing records.

Fix the code by using `goto done` instead so that any potential error
codes are properly returned to the caller.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:54:20 -08:00
René Scharfe 54d8a2531b t1006: prefer shell loop to awk for packed object sizes
To compute the expected on-disk size of packed objects, we sort the
output of show-index by pack offset and then compute the difference
between adjacent entries using awk. This works but has a few readability
problems:

  1. Reading the index in pack order means don't find out the size of an
     oid's entry until we see the _next_ entry. So we have to save it to
     print later.

     We can instead iterate in reverse order, so we compute each oid's
     size as we see it.

  2. Since the awk invocation is inside a text_expect block, we can't
     easily use single-quotes to hold the script. So we use
     double-quotes, but then have to escape the dollar signs in the awk
     script.

     We can swap this out for a shell loop instead (which is made much
     easier by the first change).

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:26:53 -08:00
Junio C Hamano a26002b628 The fifth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-02 13:51:30 -08:00
Junio C Hamano dbf668a1b7 Merge branch 'ps/pseudo-refs'
Assorted changes around pseudoref handling.

* ps/pseudo-refs:
  bisect: consistently write BISECT_EXPECTED_REV via the refdb
  refs: complete list of special refs
  refs: propagate errno when reading special refs fails
  wt-status: read HEAD and ORIG_HEAD via the refdb
2024-01-02 13:51:30 -08:00
Junio C Hamano 601b1571e8 Merge branch 'jc/orphan-unborn'
Doc updates to clarify what an "unborn branch" means.

* jc/orphan-unborn:
  orphan/unborn: fix use of 'orphan' in end-user facing messages
  orphan/unborn: add to the glossary and use them consistently
2024-01-02 13:51:30 -08:00
Junio C Hamano cce4778520 Merge branch 'rj/status-bisect-while-rebase'
"git status" is taught to show both the branch being bisected and
being rebased when both are in effect at the same time.

* rj/status-bisect-while-rebase:
  status: fix branch shown when not only bisecting
2024-01-02 13:51:29 -08:00
Junio C Hamano 59a29e1274 Merge branch 'la/trailer-cleanups'
Code clean-up.

* la/trailer-cleanups:
  trailer: use offsets for trailer_start/trailer_end
  trailer: find the end of the log message
  commit: ignore_non_trailer computes number of bytes to ignore
2024-01-02 13:51:29 -08:00
Junio C Hamano 43ec879169 Merge branch 'jc/retire-cas-opt-name-constant'
Code clean-up.

* jc/retire-cas-opt-name-constant:
  remote.h: retire CAS_OPT_NAME
2024-01-02 13:51:29 -08:00
Junio C Hamano 9cc710098b Merge branch 'rs/rebase-use-strvec-pushf'
Code clean-up.

* rs/rebase-use-strvec-pushf:
  rebase: use strvec_pushf() for format-patch revisions
2024-01-02 13:51:29 -08:00
Junio C Hamano 72e6a61c40 Merge branch 'sh/completion-with-reftable'
Command line completion script (in contrib/) learned to work better
with the reftable backend.

* sh/completion-with-reftable:
  completion: support pseudoref existence checks for reftables
  completion: refactor existence checks for pseudorefs
2024-01-02 13:51:28 -08:00
Patrick Steinhardt 1b2234079b t9500: write "extensions.refstorage" into config
In t9500 we're writing a custom configuration that sets up gitweb. This
requires us to manually ensure that the repository format is configured
as required, including both the repository format version and
extensions. With the introduction of the "extensions.refStorage"
extension we need to update the test to also write this new one.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-02 09:24:49 -08:00
Patrick Steinhardt 5ed860f51b builtin/clone: introduce --ref-format= value flag
Introduce a new `--ref-format` value flag for git-clone(1) that allows
the user to specify the ref format that is to be used for a newly
initialized repository.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-02 09:24:48 -08:00
Patrick Steinhardt 48fa45f5fb builtin/init: introduce --ref-format= value flag
Introduce a new `--ref-format` value flag for git-init(1) that allows
the user to specify the ref format that is to be used for a newly
initialized repository.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-02 09:24:48 -08:00
Patrick Steinhardt 3c4a5318af builtin/rev-parse: introduce --show-ref-format flag
Introduce a new `--show-ref-format` to git-rev-parse(1) that causes it
to print the ref format used by a repository.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-02 09:24:48 -08:00
Patrick Steinhardt 58aaf59133 t: introduce GIT_TEST_DEFAULT_REF_FORMAT envvar
Introduce a new GIT_TEST_DEFAULT_REF_FORMAT environment variable that
lets developers run the test suite with a different default ref format
without impacting the ref format used by non-test Git invocations. This
is modeled after GIT_TEST_DEFAULT_OBJECT_FORMAT, which does the same
thing for the repository's object format.

Adapt the setup of the `REFFILES` test prerequisite to be conditionally
set based on the default ref format.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-02 09:24:48 -08:00
Patrick Steinhardt aa19619a98 setup: introduce GIT_DEFAULT_REF_FORMAT envvar
Introduce a new GIT_DEFAULT_REF_FORMAT environment variable that lets
users control the default ref format used by both git-init(1) and
git-clone(1). This is modeled after GIT_DEFAULT_OBJECT_FORMAT, which
does the same thing for the repository's object format.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-02 09:24:48 -08:00
Patrick Steinhardt d7497a42b0 setup: introduce "extensions.refStorage" extension
Introduce a new "extensions.refStorage" extension that allows us to
specify the ref storage format used by a repository. For now, the only
supported format is the "files" format, but this list will likely soon
be extended to also support the upcoming "reftable" format.

There have been discussions on the Git mailing list in the past around
how exactly this extension should look like. One alternative [1] that
was discussed was whether it would make sense to model the extension in
such a way that backends are arbitrarily stackable. This would allow for
a combined value of e.g. "loose,packed-refs" or "loose,reftable", which
indicates that new refs would be written via "loose" files backend and
compressed into "packed-refs" or "reftable" backends, respectively.

It is arguable though whether this flexibility and the complexity that
it brings with it is really required for now. It is not foreseeable that
there will be a proliferation of backends in the near-term future, and
the current set of existing formats and formats which are on the horizon
can easily be configured with the much simpler proposal where we have a
single value, only.

Furthermore, if we ever see that we indeed want to gain the ability to
arbitrarily stack the ref formats, then we can adapt the current
extension rather easily. Given that Git clients will refuse any unknown
value for the "extensions.refStorage" extension they would also know to
ignore a stacked "loose,packed-refs" in the future.

So let's stick with the easy proposal for the time being and wire up the
extension.

[1]: <pull.1408.git.1667846164.gitgitgadget@gmail.com>

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-02 09:24:48 -08:00