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2024-02-27refs/reftable: don't fail empty transactions in repo without HEADPatrick Steinhardt
Under normal circumstances, it shouldn't ever happen that a repository has no HEAD reference. In fact, git-update-ref(1) would fail any request to delete the HEAD reference, and a newly initialized repository always pre-creates it, too. We have however changed git-clone(1) to partially initialize the refdb just up to the point where remote helpers can find the repository. With that change, we are going to run into a situation where repositories have no refs at all. Now there is a very particular edge case in this situation: when preparing an empty ref transacton, we end up returning whatever value `read_ref_without_reload()` returned to the caller. Under normal conditions this would be fine: "HEAD" should usually exist, and thus the function would return `0`. But if "HEAD" doesn't exist, the function returns a positive value which we end up returning to the caller. Fix this bug by resetting the return code to `0` and add a test. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-23for-each-ref: add new option to include root refsKarthik Nayak
The git-for-each-ref(1) command doesn't provide a way to print root refs i.e pseudorefs and HEAD with the regular "refs/" prefixed refs. This commit adds a new option "--include-root-refs" to git-for-each-ref(1). When used this would also print pseudorefs and HEAD for the current worktree. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-23refs: introduce `refs_for_each_include_root_refs()`Karthik Nayak
Introduce a new ref iteration flag `DO_FOR_EACH_INCLUDE_ROOT_REFS`, which will be used to iterate over regular refs plus pseudorefs and HEAD. Refs which fall outside the `refs/` and aren't either pseudorefs or HEAD are more of a grey area. This is because we don't block the users from creating such refs but they are not officially supported. Introduce `refs_for_each_include_root_refs()` which calls `do_for_each_ref()` with this newly introduced flag. In `refs/files-backend.c`, introduce a new function `add_pseudoref_and_head_entries()` to add pseudorefs and HEAD to the `ref_dir`. We then finally call `add_pseudoref_and_head_entries()` whenever the `DO_FOR_EACH_INCLUDE_ROOT_REFS` flag is set. Any new ref backend will also have to implement similar changes on its end. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-23refs: extract out `loose_fill_ref_dir_regular_file()`Karthik Nayak
Extract out the code for adding a single file to the loose ref dir as `loose_fill_ref_dir_regular_file()` from `loose_fill_ref_dir()` in `refs/files-backend.c`. This allows us to use this function independently in the following commits where we add code to also add pseudorefs to the ref dir. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-21refs: stop resolving ref corresponding to reflogsPatrick Steinhardt
The reflog iterator tries to resolve the corresponding ref for every reflog that it is about to yield. Historically, this was done due to multiple reasons: - It ensures that the refname is safe because we end up calling `check_refname_format()`. Also, non-conformant refnames are skipped altogether. - The iterator used to yield the resolved object ID as well as its flags to the callback. This info was never used though, and the corresponding parameters were dropped in the preceding commit. - When a ref is corrupt then the reflog is not emitted at all. We're about to introduce a new `git reflog list` subcommand that will print all reflogs that the refdb knows about. Skipping over reflogs whose refs are corrupted would be quite counterproductive in this case as the user would have no way to learn about reflogs which may still exist in their repository to help and rescue such a corrupted ref. Thus, the only remaining reason for why we'd want to resolve the ref is to verify its refname. Refactor the code to call `check_refname_format()` directly instead of trying to resolve the ref. This is significantly more efficient given that we don't have to hit the object database anymore to list reflogs. And second, it ensures that we end up showing reflogs of broken refs, which will help to make the reflog more useful. Note that this really only impacts the case where the corresponding ref is corrupt. Reflogs for nonexistent refs would have been returned to the caller beforehand already as we did not pass `RESOLVE_REF_READING` to the function, and thus `refs_resolve_ref_unsafe()` would have returned successfully in that case. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-21refs: drop unused params from the reflog iterator callbackPatrick Steinhardt
The ref and reflog iterators share much of the same underlying code to iterate over the corresponding entries. This results in some weird code because the reflog iterator also exposes an object ID as well as a flag to the callback function. Neither of these fields do refer to the reflog though -- they refer to the corresponding ref with the same name. This is quite misleading. In practice at least the object ID cannot really be implemented in any other way as a reflog does not have a specific object ID in the first place. This is further stressed by the fact that none of the callbacks except for our test helper make use of these fields. Split up the infrastucture so that ref and reflog iterators use separate callback signatures. This allows us to drop the nonsensical fields from the reflog iterator. Note that internally, the backends still use the same shared infra to iterate over both types. As the backends should never end up being called directly anyway, this is not much of a problem and thus kept as-is for simplicity's sake. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-21refs: always treat iterators as orderedPatrick Steinhardt
In the preceding commit we have converted the reflog iterator of the "files" backend to be ordered, which was the only remaining ref iterator that wasn't ordered. Refactor the ref iterator infrastructure so that we always assume iterators to be ordered, thus simplifying the code. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-21refs/files: sort merged worktree and common reflogsPatrick Steinhardt
When iterating through reflogs in a worktree we create a merged iterator that merges reflogs from both refdbs. The resulting refs are ordered so that instead we first return all worktree reflogs before we return all common refs. This is the only remaining case where a ref iterator returns entries in a non-lexicographic order. The result would look something like the following (listed with a command we introduce in a subsequent commit): ``` $ git reflog list HEAD refs/worktree/per-worktree refs/heads/main refs/heads/wt ``` So we first print the per-worktree reflogs in lexicographic order, then the common reflogs in lexicographic order. This is confusing and not consistent with how we print per-worktree refs, which are exclusively sorted lexicographically. Sort reflogs lexicographically in the same way as we sort normal refs. As this is already implemented properly by the "reftable" backend via a separate selection function, we simply pull out that logic and reuse it for the "files" backend. As logs are properly sorted now, mark the merged reflog iterator as sorted. Tests will be added in a subsequent commit. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-21refs/files: sort reflogs returned by the reflog iteratorPatrick Steinhardt
We use a directory iterator to return reflogs via the reflog iterator. This iterator returns entries in the same order as readdir(3P) would and will thus yield reflogs with no discernible order. Set the new `DIR_ITERATOR_SORTED` flag that was introduced in the preceding commit so that the order is deterministic. While the effect of this can only been observed in a test tool, a subsequent commit will start to expose this functionality to users via a new `git reflog list` subcommand. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-07refs/reftable: fix leak when copying reflog failsPatrick Steinhardt
When copying a ref with the reftable backend we also copy the corresponding log records. When seeking the first log record that we're about to copy fails though we directly return from `write_copy_table()` without doing any cleanup, leaking several allocated data structures. Fix this by exiting via our common cleanup logic instead. Reported-by: Jeff King <peff@peff.net> via Coverity Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-07refs: introduce reftable backendPatrick Steinhardt
Due to scalability issues, Shawn Pearce has originally proposed a new "reftable" format more than six years ago [1]. Initially, this new format was implemented in JGit with promising results. Around two years ago, we have then added the "reftable" library to the Git codebase via a4bbd13be3 (Merge branch 'hn/reftable', 2021-12-15). With this we have landed all the low-level code to read and write reftables. Notably missing though was the integration of this low-level code into the Git code base in the form of a new ref backend that ties all of this together. This gap is now finally closed by introducing a new "reftable" backend into the Git codebase. This new backend promises to bring some notable improvements to Git repositories: - It becomes possible to do truly atomic writes where either all refs are committed to disk or none are. This was not possible with the "files" backend because ref updates were split across multiple loose files. - The disk space required to store many refs is reduced, both compared to loose refs and packed-refs. This is enabled both by the reftable format being a binary format, which is more compact, and by prefix compression. - We can ignore filesystem-specific behaviour as ref names are not encoded via paths anymore. This means there is no need to handle case sensitivity on Windows systems or Unicode precomposition on macOS. - There is no need to rewrite the complete refdb anymore every time a ref is being deleted like it was the case for packed-refs. This means that ref deletions are now constant time instead of scaling linearly with the number of refs. - We can ignore file/directory conflicts so that it becomes possible to store both "refs/heads/foo" and "refs/heads/foo/bar". - Due to this property we can retain reflogs for deleted refs. We have previously been deleting reflogs together with their refs to avoid file/directory conflicts, which is not necessary anymore. - We can properly enumerate all refs. With the "files" backend it is not easily possible to distinguish between refs and non-refs because they may live side by side in the gitdir. Not all of these improvements are realized with the current "reftable" backend implementation. At this point, the new backend is supposed to be a drop-in replacement for the "files" backend that is used by basically all Git repositories nowadays. It strives for 1:1 compatibility, which means that a user can expect the same behaviour regardless of whether they use the "reftable" backend or the "files" backend for most of the part. Most notably, this means we artificially limit the capabilities of the "reftable" backend to match the limits of the "files" backend. It is not possible to create refs that would end up with file/directory conflicts, we do not retain reflogs, we perform stricter-than-necessary checks. This is done intentionally due to two main reasons: - It makes it significantly easier to land the "reftable" backend as tests behave the same. It would be tough to argue for each and every single test that doesn't pass with the "reftable" backend. - It ensures compatibility between repositories that use the "files" backend and repositories that use the "reftable" backend. Like this, hosters can migrate their repositories to use the "reftable" backend without causing issues for clients that use the "files" backend in their clones. It is expected that these artificial limitations may eventually go away in the long term. Performance-wise things very much depend on the actual workload. The following benchmarks compare the "files" and "reftable" backends in the current version: - Creating N refs in separate transactions shows that the "files" backend is ~50% faster. This is not surprising given that creating a ref only requires us to create a single loose ref. The "reftable" backend will also perform auto compaction on updates. In real-world workloads we would likely also want to perform pack loose refs, which would likely change the picture. Benchmark 1: update-ref: create refs sequentially (refformat = files, refcount = 1) Time (mean ± σ): 2.1 ms ± 0.3 ms [User: 0.6 ms, System: 1.7 ms] Range (min … max): 1.8 ms … 4.3 ms 133 runs Benchmark 2: update-ref: create refs sequentially (refformat = reftable, refcount = 1) Time (mean ± σ): 2.7 ms ± 0.1 ms [User: 0.6 ms, System: 2.2 ms] Range (min … max): 2.4 ms … 2.9 ms 132 runs Benchmark 3: update-ref: create refs sequentially (refformat = files, refcount = 1000) Time (mean ± σ): 1.975 s ± 0.006 s [User: 0.437 s, System: 1.535 s] Range (min … max): 1.969 s … 1.980 s 3 runs Benchmark 4: update-ref: create refs sequentially (refformat = reftable, refcount = 1000) Time (mean ± σ): 2.611 s ± 0.013 s [User: 0.782 s, System: 1.825 s] Range (min … max): 2.597 s … 2.622 s 3 runs Benchmark 5: update-ref: create refs sequentially (refformat = files, refcount = 100000) Time (mean ± σ): 198.442 s ± 0.241 s [User: 43.051 s, System: 155.250 s] Range (min … max): 198.189 s … 198.670 s 3 runs Benchmark 6: update-ref: create refs sequentially (refformat = reftable, refcount = 100000) Time (mean ± σ): 294.509 s ± 4.269 s [User: 104.046 s, System: 190.326 s] Range (min … max): 290.223 s … 298.761 s 3 runs - Creating N refs in a single transaction shows that the "files" backend is significantly slower once we start to write many refs. The "reftable" backend only needs to update two files, whereas the "files" backend needs to write one file per ref. Benchmark 1: update-ref: create many refs (refformat = files, refcount = 1) Time (mean ± σ): 1.9 ms ± 0.1 ms [User: 0.4 ms, System: 1.4 ms] Range (min … max): 1.8 ms … 2.6 ms 151 runs Benchmark 2: update-ref: create many refs (refformat = reftable, refcount = 1) Time (mean ± σ): 2.5 ms ± 0.1 ms [User: 0.7 ms, System: 1.7 ms] Range (min … max): 2.4 ms … 3.4 ms 148 runs Benchmark 3: update-ref: create many refs (refformat = files, refcount = 1000) Time (mean ± σ): 152.5 ms ± 5.2 ms [User: 19.1 ms, System: 133.1 ms] Range (min … max): 148.5 ms … 167.8 ms 15 runs Benchmark 4: update-ref: create many refs (refformat = reftable, refcount = 1000) Time (mean ± σ): 58.0 ms ± 2.5 ms [User: 28.4 ms, System: 29.4 ms] Range (min … max): 56.3 ms … 72.9 ms 40 runs Benchmark 5: update-ref: create many refs (refformat = files, refcount = 1000000) Time (mean ± σ): 152.752 s ± 0.710 s [User: 20.315 s, System: 131.310 s] Range (min … max): 152.165 s … 153.542 s 3 runs Benchmark 6: update-ref: create many refs (refformat = reftable, refcount = 1000000) Time (mean ± σ): 51.912 s ± 0.127 s [User: 26.483 s, System: 25.424 s] Range (min … max): 51.769 s … 52.012 s 3 runs - Deleting a ref in a fully-packed repository shows that the "files" backend scales with the number of refs. The "reftable" backend has constant-time deletions. Benchmark 1: update-ref: delete ref (refformat = files, refcount = 1) Time (mean ± σ): 1.7 ms ± 0.1 ms [User: 0.4 ms, System: 1.2 ms] Range (min … max): 1.6 ms … 2.1 ms 316 runs Benchmark 2: update-ref: delete ref (refformat = reftable, refcount = 1) Time (mean ± σ): 1.8 ms ± 0.1 ms [User: 0.4 ms, System: 1.3 ms] Range (min … max): 1.7 ms … 2.1 ms 294 runs Benchmark 3: update-ref: delete ref (refformat = files, refcount = 1000) Time (mean ± σ): 2.0 ms ± 0.1 ms [User: 0.5 ms, System: 1.4 ms] Range (min … max): 1.9 ms … 2.5 ms 287 runs Benchmark 4: update-ref: delete ref (refformat = reftable, refcount = 1000) Time (mean ± σ): 1.9 ms ± 0.1 ms [User: 0.5 ms, System: 1.3 ms] Range (min … max): 1.8 ms … 2.1 ms 217 runs Benchmark 5: update-ref: delete ref (refformat = files, refcount = 1000000) Time (mean ± σ): 229.8 ms ± 7.9 ms [User: 182.6 ms, System: 46.8 ms] Range (min … max): 224.6 ms … 245.2 ms 6 runs Benchmark 6: update-ref: delete ref (refformat = reftable, refcount = 1000000) Time (mean ± σ): 2.0 ms ± 0.0 ms [User: 0.6 ms, System: 1.3 ms] Range (min … max): 2.0 ms … 2.1 ms 3 runs - Listing all refs shows no significant advantage for either of the backends. The "files" backend is a bit faster, but not by a significant margin. When repositories are not packed the "reftable" backend outperforms the "files" backend because the "reftable" backend performs auto-compaction. Benchmark 1: show-ref: print all refs (refformat = files, refcount = 1, packed = true) Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms] Range (min … max): 1.5 ms … 2.0 ms 1729 runs Benchmark 2: show-ref: print all refs (refformat = reftable, refcount = 1, packed = true) Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms] Range (min … max): 1.5 ms … 1.8 ms 1816 runs Benchmark 3: show-ref: print all refs (refformat = files, refcount = 1000, packed = true) Time (mean ± σ): 4.3 ms ± 0.1 ms [User: 0.9 ms, System: 3.3 ms] Range (min … max): 4.1 ms … 4.6 ms 645 runs Benchmark 4: show-ref: print all refs (refformat = reftable, refcount = 1000, packed = true) Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 1.0 ms, System: 3.3 ms] Range (min … max): 4.2 ms … 5.9 ms 643 runs Benchmark 5: show-ref: print all refs (refformat = files, refcount = 1000000, packed = true) Time (mean ± σ): 2.537 s ± 0.034 s [User: 0.488 s, System: 2.048 s] Range (min … max): 2.511 s … 2.627 s 10 runs Benchmark 6: show-ref: print all refs (refformat = reftable, refcount = 1000000, packed = true) Time (mean ± σ): 2.712 s ± 0.017 s [User: 0.653 s, System: 2.059 s] Range (min … max): 2.692 s … 2.752 s 10 runs Benchmark 7: show-ref: print all refs (refformat = files, refcount = 1, packed = false) Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms] Range (min … max): 1.5 ms … 1.9 ms 1834 runs Benchmark 8: show-ref: print all refs (refformat = reftable, refcount = 1, packed = false) Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms] Range (min … max): 1.4 ms … 2.0 ms 1840 runs Benchmark 9: show-ref: print all refs (refformat = files, refcount = 1000, packed = false) Time (mean ± σ): 13.8 ms ± 0.2 ms [User: 2.8 ms, System: 10.8 ms] Range (min … max): 13.3 ms … 14.5 ms 208 runs Benchmark 10: show-ref: print all refs (refformat = reftable, refcount = 1000, packed = false) Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 1.2 ms, System: 3.3 ms] Range (min … max): 4.3 ms … 6.2 ms 624 runs Benchmark 11: show-ref: print all refs (refformat = files, refcount = 1000000, packed = false) Time (mean ± σ): 12.127 s ± 0.129 s [User: 2.675 s, System: 9.451 s] Range (min … max): 11.965 s … 12.370 s 10 runs Benchmark 12: show-ref: print all refs (refformat = reftable, refcount = 1000000, packed = false) Time (mean ± σ): 2.799 s ± 0.022 s [User: 0.735 s, System: 2.063 s] Range (min … max): 2.769 s … 2.836 s 10 runs - Printing a single ref shows no real difference between the "files" and "reftable" backends. Benchmark 1: show-ref: print single ref (refformat = files, refcount = 1) Time (mean ± σ): 1.5 ms ± 0.1 ms [User: 0.4 ms, System: 1.0 ms] Range (min … max): 1.4 ms … 1.8 ms 1779 runs Benchmark 2: show-ref: print single ref (refformat = reftable, refcount = 1) Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms] Range (min … max): 1.4 ms … 2.5 ms 1753 runs Benchmark 3: show-ref: print single ref (refformat = files, refcount = 1000) Time (mean ± σ): 1.5 ms ± 0.1 ms [User: 0.3 ms, System: 1.1 ms] Range (min … max): 1.4 ms … 1.9 ms 1840 runs Benchmark 4: show-ref: print single ref (refformat = reftable, refcount = 1000) Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms] Range (min … max): 1.5 ms … 2.0 ms 1831 runs Benchmark 5: show-ref: print single ref (refformat = files, refcount = 1000000) Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms] Range (min … max): 1.5 ms … 2.1 ms 1848 runs Benchmark 6: show-ref: print single ref (refformat = reftable, refcount = 1000000) Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms] Range (min … max): 1.5 ms … 2.1 ms 1762 runs So overall, performance depends on the usecases. Except for many sequential writes the "reftable" backend is roughly on par or significantly faster than the "files" backend though. Given that the "files" backend has received 18 years of optimizations by now this can be seen as a win. Furthermore, we can expect that the "reftable" backend will grow faster over time when attention turns more towards optimizations. The complete test suite passes, except for those tests explicitly marked to require the REFFILES prerequisite. Some tests in t0610 are marked as failing because they depend on still-in-flight bug fixes. Tests can be run with the new backend by setting the GIT_TEST_DEFAULT_REF_FORMAT environment variable to "reftable". There is a single known conceptual incompatibility with the dumb HTTP transport. As "info/refs" SHOULD NOT contain the HEAD reference, and because the "HEAD" file is not valid anymore, it is impossible for the remote client to figure out the default branch without changing the protocol. This shortcoming needs to be handled in a subsequent patch series. As the reftable library has already been introduced a while ago, this commit message will not go into the details of how exactly the on-disk format works. Please refer to our preexisting technical documentation at Documentation/technical/reftable for this. [1]: https://public-inbox.org/git/CAJo=hJtyof=HRy=2sLP0ng0uZ4=S-DpZ5dR1aF+VHVETKG20OQ@mail.gmail.com/ Original-idea-by: Shawn Pearce <spearce@spearce.org> Based-on-patch-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-26Merge branch 'ps/worktree-refdb-initialization'Junio C Hamano
Instead of manually creating refs/ hierarchy on disk upon a creation of a secondary worktree, which is only usable via the files backend, use the refs API to populate it. * ps/worktree-refdb-initialization: builtin/worktree: create refdb via ref backend worktree: expose interface to look up worktree by name builtin/worktree: move setup of commondir file earlier refs/files: skip creation of "refs/{heads,tags}" for worktrees setup: move creation of "refs/" into the files backend refs: prepare `refs_init_db()` for initializing worktree refs
2024-01-16Merge branch 'ps/refstorage-extension'Junio C Hamano
Introduce a new extension "refstorage" so that we can mark a repository that uses a non-default ref backend, like reftable. * 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
2024-01-08Merge branch 'en/header-cleanup'Junio C Hamano
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
2024-01-08refs/files: skip creation of "refs/{heads,tags}" for worktreesPatrick Steinhardt
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>
2024-01-08setup: move creation of "refs/" into the files backendPatrick Steinhardt
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>
2024-01-08refs: prepare `refs_init_db()` for initializing worktree refsPatrick Steinhardt
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>
2024-01-02refs: refactor logic to look up storage backendsPatrick Steinhardt
In order to look up ref storage backends, we're currently using a linked list of backends, where each backend is expected to set up its `next` pointer to the next ref storage backend. This is kind of a weird setup as backends need to be aware of other backends without much of a reason. Refactor the code so that the array of backends is centrally defined in "refs.c", where each backend is now identified by an integer constant. Expose functions to translate from those integer constants to the name and vice versa, which will be required by subsequent patches. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-26treewide: remove unnecessary includes in source filesElijah Newren
Each of these were checked with gcc -E -I. ${SOURCE_FILE} | grep ${HEADER_FILE} to ensure that removing the direct inclusion of the header actually resulted in that header no longer being included at all (i.e. that no other header pulled it in transitively). ...except for a few cases where we verified that although the header was brought in transitively, nothing from it was directly used in that source file. These cases were: * builtin/credential-cache.c * builtin/pull.c * builtin/send-pack.c Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-17refs: remove `delete_refs` callback from backendsPatrick Steinhardt
Now that `refs_delete_refs` is implemented in a generic way via the ref transaction interfaces there are no callers left that invoke the `delete_refs` callback anymore. Remove it from all of our backends. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-17refs: deduplicate code to delete referencesPatrick Steinhardt
Both the files and the packed-refs reference backends now use the same generic transactions-based code to delete references. Let's pull these implementations up into `refs_delete_refs()` to deduplicate the code. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-17refs/files: use transactions to delete referencesPatrick Steinhardt
In the `files_delete_refs()` callback function of the files backend we implement deletion of references. This is done in two steps: 1. We lock the packed-refs file and delete all references from it in a single transaction. 2. We delete all loose references via separate calls to `refs_delete_ref()`. These steps essentially duplicate the logic around locking and deletion order that we already have in the transactional interfaces, where we do know to lock and evict references from the packed-refs file. Despite the fact that we duplicate the logic, it's also less efficient than if we used a single generic transaction: - The transactional interface knows to skip locking of the packed refs in case they don't contain any of the refs which are about to be deleted. - We end up creating N+1 separate reference transactions, one for the packed-refs file and N for the individual loose references. Refactor the code to instead delete references via a single transaction. As we don't assert the expected old object ID this is equivalent to the previous behaviour, and we already do the same in the packed-refs backend. Despite the fact that the result is simpler to reason about, this change also results in improved performance. The following benchmarks have been executed in linux.git: ``` $ hyperfine -n '{rev}, packed={packed} refcount={refcount}' \ -L packed true,false -L refcount 1,1000 -L rev master,pks-ref-store-generic-delete-refs \ --setup 'git -C /home/pks/Development/git switch --detach {rev} && make -C /home/pks/Development/git -j17' \ --prepare 'printf "create refs/heads/new-branch-%d HEAD\n" $(seq {refcount}) | git -C /home/pks/Reproduction/linux.git update-ref --stdin && if test {packed} = true; then git pack-refs --all; fi' \ --warmup=10 \ '/home/pks/Development/git/bin-wrappers/git -C /home/pks/Reproduction/linux.git branch -d new-branch-{1..{refcount}}' Benchmark 1: master packed=true refcount=1 Time (mean ± σ): 7.8 ms ± 1.6 ms [User: 3.4 ms, System: 4.4 ms] Range (min … max): 5.5 ms … 11.0 ms 120 runs Benchmark 2: master packed=false refcount=1 Time (mean ± σ): 7.0 ms ± 1.1 ms [User: 3.2 ms, System: 3.8 ms] Range (min … max): 5.7 ms … 9.8 ms 180 runs Benchmark 3: master packed=true refcount=1000 Time (mean ± σ): 283.8 ms ± 5.2 ms [User: 45.7 ms, System: 231.5 ms] Range (min … max): 276.7 ms … 291.6 ms 10 runs Benchmark 4: master packed=false refcount=1000 Time (mean ± σ): 284.4 ms ± 5.3 ms [User: 44.2 ms, System: 233.6 ms] Range (min … max): 277.1 ms … 293.3 ms 10 runs Benchmark 5: generic-delete-refs packed=true refcount=1 Time (mean ± σ): 6.2 ms ± 1.8 ms [User: 2.3 ms, System: 3.9 ms] Range (min … max): 4.1 ms … 12.2 ms 142 runs Benchmark 6: generic-delete-refs packed=false refcount=1 Time (mean ± σ): 7.1 ms ± 1.4 ms [User: 2.8 ms, System: 4.3 ms] Range (min … max): 4.2 ms … 10.8 ms 157 runs Benchmark 7: generic-delete-refs packed=true refcount=1000 Time (mean ± σ): 198.9 ms ± 1.7 ms [User: 29.5 ms, System: 165.7 ms] Range (min … max): 196.1 ms … 201.4 ms 10 runs Benchmark 8: generic-delete-refs packed=false refcount=1000 Time (mean ± σ): 199.7 ms ± 7.8 ms [User: 32.2 ms, System: 163.2 ms] Range (min … max): 193.8 ms … 220.7 ms 10 runs Summary generic-delete-refs packed=true refcount=1 ran 1.14 ± 0.37 times faster than master packed=false refcount=1 1.15 ± 0.40 times faster than generic-delete-refs packed=false refcount=1 1.26 ± 0.44 times faster than master packed=true refcount=1 32.24 ± 9.17 times faster than generic-delete-refs packed=true refcount=1000 32.36 ± 9.29 times faster than generic-delete-refs packed=false refcount=1000 46.00 ± 13.10 times faster than master packed=true refcount=1000 46.10 ± 13.13 times faster than master packed=false refcount=1000 ``` Especially in the case where we have many references we can see a clear performance speedup of nearly 30%. This is in contrast to the stated objecive in a27dcf89b68 (refs: make delete_refs() virtual, 2016-09-04), where the virtual `delete_refs()` function was introduced with the intent to speed things up rather than making things slower. So it seems like we have outlived the need for a virtual function. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-09files-backend.c: avoid stat in 'loose_fill_ref_dir'Victoria Dye
Modify the 'readdir' loop in 'loose_fill_ref_dir' to, rather than 'stat' a file to determine whether it is a directory or not, use 'get_dtype'. Currently, the loop uses 'stat' to determine whether each dirent is a directory itself or not in order to construct the appropriate ref cache entry. If 'stat' fails (returning a negative value), the dirent is silently skipped; otherwise, 'S_ISDIR(st.st_mode)' is used to check whether the entry is a directory. On platforms that include an entry's d_type in in the 'dirent' struct, this extra 'stat' check is redundant. We can use the 'get_dtype' method to extract this information on platforms that support it (i.e. where NO_D_TYPE_IN_DIRENT is unset), and derive it with 'stat' on platforms that don't. Because 'stat' is an expensive call, this confers a modest-but-noticeable performance improvement when iterating over large numbers of refs (approximately 20% speedup in 'git for-each-ref' in a 30k ref repo). Unlike other existing usage of 'get_dtype', the 'follow_symlinks' arg is set to 1 to replicate the existing handling of symlink dirents. This unfortunately requires calling 'stat' on the associated entry regardless of platform, but symlinks in the loose ref store are highly unlikely since they'd need to be created manually by a user. Note that this patch also changes the condition for skipping creation of a ref entry from "when 'stat' fails" to "when the d_type is anything other than DT_REG or DT_DIR". If a dirent's d_type is DT_UNKNOWN (either because the platform doesn't support d_type in dirents or some other reason) or DT_LNK, 'get_dtype' will try to derive the underlying type with 'stat'. If the 'stat' fails, the d_type will remain 'DT_UNKNOWN' and dirent will be skipped. However, it will also be skipped if it is any other valid d_type (e.g. DT_FIFO for named pipes, DT_LNK for a nested symlink). Git does not handle these properly anyway, so we can safely constrain accepted types to directories and regular files. Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-09ref-cache.c: fix prefix matching in ref iterationVictoria Dye
Update 'cache_ref_iterator_advance' to skip over refs that are not matched by the given prefix. Currently, a ref entry is considered "matched" if the entry name is fully contained within the prefix: * prefix: "refs/heads/v1" * entry: "refs/heads/v1.0" OR if the prefix is fully contained in the entry name: * prefix: "refs/heads/v1.0" * entry: "refs/heads/v1" The first case is always correct, but the second is only correct if the ref cache entry is a directory, for example: * prefix: "refs/heads/example" * entry: "refs/heads/" Modify the logic in 'cache_ref_iterator_advance' to reflect these expectations: 1. If 'overlaps_prefix' returns 'PREFIX_EXCLUDES_DIR', then the prefix and ref cache entry do not overlap at all. Skip this entry. 2. If 'overlaps_prefix' returns 'PREFIX_WITHIN_DIR', then the prefix matches inside this entry if it is a directory. Skip if the entry is not a directory, otherwise iterate over it. 3. Otherwise, 'overlaps_prefix' returned 'PREFIX_CONTAINS_DIR', indicating that the cache entry (directory or not) is fully contained by or equal to the prefix. Iterate over this entry. Note that condition 2 relies on the names of directory entries having the appropriate trailing slash. The existing function documentation of 'create_dir_entry' explicitly calls out the trailing slash requirement, so this is a safe assumption to make. This bug generally doesn't have any user-facing impact, since it requires: 1. using a non-empty prefix without a trailing slash in an iteration like 'for_each_fullref_in', 2. the callback to said iteration not reapplying the original filter (as for-each-ref does) to ensure unmatched refs are skipped, and 3. the repository having one or more refs that match part of, but not all of, the prefix. However, there are some niche scenarios that meet those criteria (specifically, 'rev-parse --bisect' and '(log|show|shortlog) --bisect'). Add tests covering those cases to demonstrate the fix in this patch. Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-21Merge branch 'tb/refs-exclusion-and-packed-refs'Junio C Hamano
Enumerating refs in the packed-refs file, while excluding refs that match certain patterns, has been optimized. * tb/refs-exclusion-and-packed-refs: ls-refs.c: avoid enumerating hidden refs where possible upload-pack.c: avoid enumerating hidden refs where possible builtin/receive-pack.c: avoid enumerating hidden references refs.h: implement `hidden_refs_to_excludes()` refs.h: let `for_each_namespaced_ref()` take excluded patterns revision.h: store hidden refs in a `strvec` refs/packed-backend.c: add trace2 counters for jump list refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) refs/packed-backend.c: refactor `find_reference_location()` refs: plumb `exclude_patterns` argument throughout builtin/for-each-ref.c: add `--exclude` option ref-filter.c: parameterize match functions over patterns ref-filter: add `ref_filter_clear()` ref-filter: clear reachable list pointers after freeing ref-filter.h: provide `REF_FILTER_INIT` refs.c: rename `ref_filter`
2023-07-10refs/packed-backend.c: add trace2 counters for jump listTaylor Blau
The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10refs/packed-backend.c: implement jump lists to avoid excluded pattern(s)Taylor Blau
When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). 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>
2023-07-10refs/packed-backend.c: refactor `find_reference_location()`Taylor Blau
The function `find_reference_location()` is used to perform a binary search-like function over the contents of a repository's `$GIT_DIR/packed-refs` file. The search it implements is unlike a standard binary search in that the records it searches over are not of a fixed width, so the comparison must locate the end of a record before comparing it. Extract the core routine of `find_reference_location()` in order to implement a function in the following patch which will find the first location in the `packed-refs` file that *doesn't* match the given pattern. The behavior of `find_reference_location()` is unchanged. 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>
2023-07-10refs: plumb `exclude_patterns` argument throughoutTaylor Blau
The subsequent patch will want to access an optional `excluded_patterns` array within `refs/packed-backend.c` that will cull out certain references matching any of the given patterns on a best-effort basis. To do so, the refs subsystem needs to be updated to pass this value across a number of different locations. Prepare for a future patch by introducing this plumbing now, passing NULLs at top-level APIs in order to make that patch less noisy and more easily readable. Signed-off-by: Taylor Blau <me@ttaylorr.co> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21repository: remove unnecessary include of path.hElijah Newren
This also made it clear that several .c files that depended upon path.h were missing a #include for it; add the missing includes while at it. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21cache.h: remove this no-longer-used headerElijah Newren
Since this header showed up in some places besides just #include statements, update/clean-up/remove those other places as well. Note that compat/fsmonitor/fsm-path-utils-darwin.c previously got away with violating the rule that all files must start with an include of git-compat-util.h (or a short-list of alternate headers that happen to include it first). This change exposed the violation and caused it to stop building correctly; fix it by having it include git-compat-util.h first, as per policy. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21statinfo: move stat_{data,validity} functions from cache/read-cacheElijah Newren
These functions do not depend upon struct cache_entry or struct index_state in any way, and it seems more logical to break them out into this file, especially since statinfo.h already has the struct stat_data declaration. Diff best viewed with `--color-moved`. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-13Merge branch 'jc/pack-ref-exclude-include'Junio C Hamano
"git pack-refs" learns "--include" and "--exclude" to tweak the ref hierarchy to be packed using pattern matching. * jc/pack-ref-exclude-include: pack-refs: teach pack-refs --include option pack-refs: teach --exclude option to exclude refs from being packed docs: clarify git-pack-refs --all will pack all refs
2023-05-12pack-refs: teach pack-refs --include optionJohn Cai
Allow users to be more selective over which refs to pack by adding an --include option to git-pack-refs. The existing options allow some measure of selectivity. By default git-pack-refs packs all tags. --all can be used to include all refs, and the previous commit added the ability to exclude certain refs with --exclude. While these knobs give the user some selection over which refs to pack, it could be useful to give more control. For instance, a repository may have a set of branches that are rarely updated and would benefit from being packed. --include would allow the user to easily include a set of branches to be packed while leaving everything else unpacked. Signed-off-by: John Cai <johncai86@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-12pack-refs: teach --exclude option to exclude refs from being packedJohn Cai
At GitLab, we have a system that creates ephemeral internal refs that don't live long before getting deleted. Having an option to exclude certain refs from a packed-refs file allows these internal references to be deleted much more efficiently. Add an --exclude option to the pack-refs builtin, and use the ref exclusions API to exclude certain refs from being packed into the final packed-refs file Signed-off-by: John Cai <johncai86@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-09Merge branch 'en/header-split-cache-h-part-2'Junio C Hamano
More header clean-up. * en/header-split-cache-h-part-2: (22 commits) reftable: ensure git-compat-util.h is the first (indirect) include diff.h: reduce unnecessary includes object-store.h: reduce unnecessary includes commit.h: reduce unnecessary includes fsmonitor: reduce includes of cache.h cache.h: remove unnecessary headers treewide: remove cache.h inclusion due to previous changes cache,tree: move basic name compare functions from read-cache to tree cache,tree: move cmp_cache_name_compare from tree.[ch] to read-cache.c hash-ll.h: split out of hash.h to remove dependency on repository.h tree-diff.c: move S_DIFFTREE_IFXMIN_NEQ define from cache.h dir.h: move DTYPE defines from cache.h versioncmp.h: move declarations for versioncmp.c functions from cache.h ws.h: move declarations for ws.c functions from cache.h match-trees.h: move declarations for match-trees.c functions from cache.h pkt-line.h: move declarations for pkt-line.c functions from cache.h base85.h: move declarations for base85.c functions from cache.h copy.h: move declarations for copy.c functions from cache.h server-info.h: move declarations for server-info.c functions from cache.h packfile.h: move pack_window and pack_entry from cache.h ...
2023-05-02Merge branch 'tb/ban-strtok'Junio C Hamano
Mark strtok() and strtok_r() to be banned. * tb/ban-strtok: banned.h: mark `strtok()` and `strtok_r()` as banned t/helper/test-json-writer.c: avoid using `strtok()` t/helper/test-oidmap.c: avoid using `strtok()` t/helper/test-hashmap.c: avoid using `strtok()` string-list: introduce `string_list_setlen()` string-list: multi-delimiter `string_list_split_in_place()`
2023-04-24string-list: multi-delimiter `string_list_split_in_place()`Taylor Blau
Enhance `string_list_split_in_place()` to accept multiple characters as delimiters instead of a single character. Instead of using `strchr(2)` to locate the first occurrence of the given delimiter character, `string_list_split_in_place_multi()` uses `strcspn(2)` to move past the initial segment of characters comprised of any characters in the delimiting set. When only a single delimiting character is provided, `strpbrk(2)` (which is implemented with `strcspn(2)`) has equivalent performance to `strchr(2)`. Modern `strcspn(2)` implementations treat an empty delimiter or the singleton delimiter as a special case and fall back to calling strchrnul(). Both glibc[1] and musl[2] implement `strcspn(2)` this way. This change is one step to removing `strtok(2)` from the tree. Note that `string_list_split_in_place()` is not a strict replacement for `strtok()`, since it will happily turn sequential delimiter characters into empty entries in the resulting string_list. For example: string_list_split_in_place(&xs, "foo:;:bar:;:baz", ":;", -1) would yield a string list of: ["foo", "", "", "bar", "", "", "baz"] Callers that wish to emulate the behavior of strtok(2) more directly should call `string_list_remove_empty_items()` after splitting. To avoid regressions for the new multi-character delimter cases, update t0063 in this patch as well. [1]: https://sourceware.org/git/?p=glibc.git;a=blob;f=string/strcspn.c;hb=glibc-2.37#l35 [2]: https://git.musl-libc.org/cgit/musl/tree/src/string/strcspn.c?h=v1.2.3#n11 Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-24commit.h: reduce unnecessary includesElijah Newren
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-24hash-ll.h: split out of hash.h to remove dependency on repository.hElijah Newren
hash.h depends upon and includes repository.h, due to the definition and use of the_hash_algo (defined as the_repository->hash_algo). However, most headers trying to include hash.h are only interested in the layout of the structs like object_id. Move the parts of hash.h that do not depend upon repository.h into a new file hash-ll.h (the "low level" parts of hash.h), and adjust other files to use this new header where the convenience inline functions aren't needed. This allows hash.h and object.h to be fairly small, minimal headers. It also exposes a lot of hidden dependencies on both path.h (which was brought in by repository.h) and repository.h (which was previously implicitly brought in by object.h), so also adjust other files to be more explicit about what they depend upon. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-24copy.h: move declarations for copy.c functions from cache.hElijah Newren
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11treewide: reduce includes of cache.h in other headersElijah Newren
We had a handful of headers including cache.h that didn't need to anymore. Drop those includes and replace them with includes of smaller files, or forward declarations. However, note that two .c files now need to directly include cache.h, though they should have been including it all along given they are directly using structs defined in it. Signed-off-by: Elijah Newren <newren@gmail.com> Acked-by: Calvin Wan <calvinwan@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11treewide: remove double forward declaration of read_in_fullElijah Newren
cache.h's nature of a dumping ground of includes prevented it from being included in some compat/ files, forcing us into a workaround of having a double forward declaration of the read_in_full() function (see commit 14086b0a13 ("compat/pread.c: Add a forward declaration to fix a warning", 2007-11-17)). Now that we have moved functions like read_in_full() from cache.h to wrapper.h, and wrapper.h isn't littered with unrelated and scary #defines, get rid of the extra forward declaration and just have compat/pread.c include wrapper.h. Signed-off-by: Elijah Newren <newren@gmail.com> Acked-by: Calvin Wan <calvinwan@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11object-file.h: move declarations for object-file.c functions from cache.hElijah Newren
Signed-off-by: Elijah Newren <newren@gmail.com> Acked-by: Calvin Wan <calvinwan@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21write-or-die.h: move declarations for write-or-die.c functions from cache.hElijah Newren
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21setup.h: move declarations for setup.c functions from cache.hElijah Newren
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21environment.h: move declarations for environment.c functions from cache.hElijah Newren
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21wrapper.h: move declarations for wrapper.c functions from cache.hElijah Newren
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21treewide: remove unnecessary cache.h inclusion from several sourcesElijah Newren
A number of files were apparently including cache.h solely to get gettext.h. By making those files explicitly include gettext.h, we can already drop the include of cache.h in these files. On top of that, there were some files using cache.h that didn't need to for any reason. Remove these unnecessary includes. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21treewide: be explicit about dependence on gettext.hElijah Newren
Dozens of files made use of gettext functions, without explicitly including gettext.h. This made it more difficult to find which files could remove a dependence on cache.h. Make C files explicitly include gettext.h if they are using it. However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an include of gettext.h, it was left out to avoid conflicting with an in-flight topic. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>