aboutsummaryrefslogtreecommitdiffstats
path: root/refs/files-backend.c (follow)
AgeCommit message (Collapse)AuthorFilesLines
2024-05-23Merge branch 'ps/pseudo-ref-terminology' into ps/ref-storage-migrationJunio C Hamano1-2/+1
* ps/pseudo-ref-terminology: refs: refuse to write pseudorefs ref-filter: properly distinuish pseudo and root refs refs: pseudorefs are no refs refs: classify HEAD as a root ref refs: do not check ref existence in `is_root_ref()` refs: rename `is_special_ref()` to `is_pseudo_ref()` refs: rename `is_pseudoref()` to `is_root_ref()` Documentation/glossary: define root refs as refs Documentation/glossary: clarify limitations of pseudorefs Documentation/glossary: redefine pseudorefs as special refs
2024-05-23Merge branch 'ps/refs-without-the-repository-updates' into ↵Junio C Hamano1-23/+36
ps/ref-storage-migration * ps/refs-without-the-repository-updates: refs/packed: remove references to `the_hash_algo` refs/files: remove references to `the_hash_algo` refs/files: use correct repository refs: remove `dwim_log()` refs: drop `git_default_branch_name()` refs: pass repo when peeling objects refs: move object peeling into "object.c" refs: pass ref store when detecting dangling symrefs refs: convert iteration over replace refs to accept ref store refs: retrieve worktree ref stores via associated repository refs: refactor `resolve_gitlink_ref()` to accept a repository refs: pass repo when retrieving submodule ref store refs: track ref stores via strmap refs: implement releasing ref storages refs: rename `init_db` callback to avoid confusion refs: adjust names for `init` and `init_db` callbacks
2024-05-17refs/files: remove references to `the_hash_algo`Patrick Steinhardt1-2/+2
Remove references to `the_hash_algo` in favor of the hash algo specified by the repository associated with the files ref store. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17refs/files: use correct repositoryPatrick Steinhardt1-10/+13
There are several places in the "files" backend where we use `the_repository` instead of the repository associated with the ref store itself. Adapt those to use the correct repository. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17refs: implement releasing ref storagesPatrick Steinhardt1-0/+10
Ref storages are typically only initialized once for `the_repository` and then never released. Until now we got away with that without causing memory leaks because `the_repository` stays reachable, and because the ref backend is reachable via `the_repository` its memory basically never leaks. This is about to change though because of the upcoming migration logic, which will create a secondary ref storage. In that case, we will either have to release the old or new ref storage to avoid leaks. Implement a new `release` callback and expose it via a new `ref_storage_release()` function. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17refs: rename `init_db` callback to avoid confusionPatrick Steinhardt1-6/+6
Reference backends have two callbacks `init` and `init_db`. The similarity of these two callbacks has repeatedly confused me whenever I was looking at them, where I always had to look up which of them does what. Rename the `init_db` callback to `create_on_disk`, which should hopefully be clearer. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17refs: adjust names for `init` and `init_db` callbacksPatrick Steinhardt1-5/+5
The names of the functions that implement the `init` and `init_db` callbacks in the "files" and "packed" backends do not match the names of the callbacks, which is inconsistent. Rename them so that they match, which makes it easier to discover their respective implementations. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-15refs: classify HEAD as a root refPatrick Steinhardt1-2/+1
Root refs are those refs that live in the root of the ref hierarchy. Our old and venerable "HEAD" reference falls into this category, but we don't yet classify it as such in `is_root_ref()`. Adapt the function to also treat "HEAD" as a root ref. This change is safe to do for all current callers: - `ref_kind_from_refname()` already handles "HEAD" explicitly before calling `is_root_ref()`. - The "files" and "reftable" backends explicitly call both `is_root_ref()` and `is_headref()` together. This also aligns behaviour or `is_root_ref()` and `is_headref()` such that we stop checking for ref existence. This changes semantics for our backends: - In the reftable backend we already know that the ref must exist because `is_headref()` is called as part of the ref iterator. The existence check is thus redundant, and the change is safe to do. - In the files backend we use it when populating root refs, where we would skip adding the "HEAD" file if it was not possible to resolve it. The new behaviour is to instead mark "HEAD" as broken, which will cause us to emit warnings in various places. As there are no callers of `is_headref()` left afer the refactoring, we can absorb it completely into `is_root_ref()`. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-15refs: do not check ref existence in `is_root_ref()`Patrick Steinhardt1-2/+2
Before this patch series, root refs except for "HEAD" and our special refs were classified as pseudorefs. Furthermore, our terminology clarified that pseudorefs must not be symbolic refs. This restriction is enforced in `is_root_ref()`, which explicitly checks that a supposed root ref resolves to an object ID without recursing. This has been extremely confusing right from the start because (in old terminology) a ref name may sometimes be a pseudoref and sometimes not depending on whether it is a symbolic or regular ref. This behaviour does not seem reasonable at all and I very much doubt that it results in anything sane. Last but not least, the current behaviour can actually lead to a segfault when calling `is_root_ref()` with a reference that either does not exist or that is a symbolic ref because we never initialized `oid`, but then read it via `is_null_oid()`. We have now changed terminology to clarify that pseudorefs are really only "MERGE_HEAD" and "FETCH_HEAD", whereas all the other refs that live in the root of the ref hierarchy are just plain refs. Thus, we do not need to check whether the ref is symbolic or not. In fact, we can now avoid looking up the ref completely as the name is sufficient for us to figure out whether something would be a root ref or not. This change of course changes semantics for our callers. As there are only three of them we can assess each of them individually: - "ref-filter.c:ref_kind_from_refname()" uses it to classify refs. It's clear that the intent is to classify based on the ref name, only. - "refs/reftable_backend.c:reftable_ref_iterator_advance()" uses it to filter root refs. Again, using existence checks is pointless here as the iterator has just surfaced the ref, so we know it does exist. - "refs/files_backend.c:add_pseudoref_and_head_entries()" uses it to determine whether it should add a ref to the root directory of its iterator. This had the effect that we skipped over any files that are either a symbolic ref, or which are not a ref at all. The new behaviour is to include symbolic refs know, which aligns us with the adapted terminology. Furthermore, files which look like root refs but aren't are now mark those as "broken". As broken refs are not surfaced by our tooling, this should not lead to a change in user-visible behaviour, but may cause us to emit warnings. This feels like the right thing to do as we would otherwise just silently ignore corrupted root refs completely. So in all cases the existence check was either superfluous, not in line with the adapted terminology or masked potential issues. This commit thus changes the behaviour as proposed and drops the existence check altogether. Add a test that verifies that this does not change user-visible behaviour. Namely, we still don't want to show broken refs to the user by default in git-for-each-ref(1). What this does allow though is for internal callers to surface dangling root refs when they pass in the `DO_FOR_EACH_INCLUDE_BROKEN` flag. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-15refs: rename `is_pseudoref()` to `is_root_ref()`Patrick Steinhardt1-1/+1
Rename `is_pseudoref()` to `is_root_ref()` to adapt to the newly defined terminology in our gitglossary(7). Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-07refs: remove `create_symref` and associated dead codeKarthik Nayak1-67/+0
In the previous commits, we converted `refs_create_symref()` to utilize transactions to perform symref updates. Earlier `refs_create_symref()` used `create_symref()` to do the same. We can now remove `create_symref()` and any code associated with it which is no longer used. We remove `create_symref()` code from all the reference backends and also remove it entirely from the `ref_storage_be` struct. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-07refs: add support for transactional symref updatesKarthik Nayak1-21/+92
The reference backends currently support transactional reference updates. While this is exposed to users via 'git-update-ref' and its '--stdin' mode, it is also used internally within various commands. However, we do not support transactional updates of symrefs. This commit adds support for symrefs in both the 'files' and the 'reftable' backend. Here, we add and use `ref_update_has_null_new_value()`, a helper function which is used to check if there is a new_value in a reference update. The new value could either be a symref target `new_target` or a OID `new_oid`. We also add another common function `ref_update_check_old_target` which will be used to check if the update's old_target corresponds to a reference's current target. Now transactional updates (verify, create, delete, update) can be used for: - regular refs - symbolic refs - conversion of regular to symbolic refs and vice versa This also allows us to expose this to users via new commands in 'git-update-ref' in the future. Note that a dangling symref update does not record a new reflog entry, which is unchanged before and after this commit. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-07refs: move `original_update_refname` to 'refs.c'Karthik Nayak1-16/+5
The files backend and the reftable backend implement `original_update_refname` to obtain the original refname of the update. Move it out to 'refs.c' and only expose it internally to the refs library. This will be used in an upcoming commit to also introduce another common functionality for the two backends. We also rename the function to `ref_update_original_update_refname` to keep it consistent with the upcoming other 'ref_update_*' functions that'll be introduced. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-07files-backend: extract out `create_symref_lock()`Karthik Nayak1-14/+37
The function `create_symref_locked()` creates a symref by creating a '<symref>.lock' file and then committing the symref lock, which creates the final symref. Extract the early half of `create_symref_locked()` into a new helper function `create_symref_lock()`. Because the name of the new function is too similar to the original, rename the original to `create_and_commit_symref()` to avoid confusion. The new function `create_symref_locked()` can be used to create the symref lock in a separate step from that of committing it. This allows to add transactional support for symrefs, where the lock would be created in the preparation step and the lock would be committed in the finish step. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-07refs: accept symref values in `ref_transaction_update()`Karthik Nayak1-6/+6
The function `ref_transaction_update()` obtains ref information and flags to create a `ref_update` and add them to the transaction at hand. To extend symref support in transactions, we need to also accept the old and new ref targets and process it. This commit adds the required parameters to the function and modifies all call sites. The two parameters added are `new_target` and `old_target`. The `new_target` is used to denote what the reference should point to when the transaction is applied. Some functions allow this parameter to be NULL, meaning that the reference is not changed. The `old_target` denotes the value the reference must have before the update. Some functions allow this parameter to be NULL, meaning that the old value of the reference is not checked. We also update the internal function `ref_transaction_add_update()` similarly to take the two new parameters. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-06refs: return conflict error when checking packed refsIvan Tse1-1/+3
The TRANSACTION_NAME_CONFLICT error code refers to a failure to create a ref due to a name conflict with another ref. An example of this is a directory/file conflict such as ref names A/B and A. "git fetch" uses this error code to more accurately describe the error by recommending to the user that they try running "git remote prune" to remove any old refs that are deleted by the remote which would clear up any directory/file conflicts. This helpful error message is not displayed when the conflicted ref is stored in packed refs. This change fixes this by ensuring error return code consistency in `lock_raw_ref`. Signed-off-by: Ivan Tse <ivan.tse1@gmail.com> Acked-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-03-05Merge branch 'kn/for-all-refs'Junio C Hamano1-34/+93
"git for-each-ref" learned "--include-root-refs" option to show even the stuff outside the 'refs/' hierarchy. * kn/for-all-refs: for-each-ref: add new option to include root refs ref-filter: rename 'FILTER_REFS_ALL' to 'FILTER_REFS_REGULAR' refs: introduce `refs_for_each_include_root_refs()` refs: extract out `loose_fill_ref_dir_regular_file()` refs: introduce `is_pseudoref()` and `is_headref()`
2024-02-23refs: introduce `refs_for_each_include_root_refs()`Karthik Nayak1-5/+60
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 Nayak1-29/+33
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 Steinhardt1-10/+2
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 Steinhardt1-7/+1
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 Steinhardt1-4/+3
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 Steinhardt1-28/+2
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 Steinhardt1-2/+2
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>
2024-01-26Merge branch 'ps/worktree-refdb-initialization'Junio C Hamano1-6/+31
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 Hamano1-1/+0
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 Hamano1-2/+0
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 Steinhardt1-8/+14
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 Steinhardt1-0/+17
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 Steinhardt1-1/+3
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 Steinhardt1-1/+0
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 Newren1-2/+0
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 Steinhardt1-7/+0
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 Steinhardt1-45/+1
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 Steinhardt1-32/+34
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 Dye1-9/+5
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>
2023-07-21Merge branch 'tb/refs-exclusion-and-packed-refs'Junio C Hamano1-2/+3
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: plumb `exclude_patterns` argument throughoutTaylor Blau1-2/+3
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 Newren1-0/+1
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 Newren1-1/+1
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>
2023-06-13Merge branch 'jc/pack-ref-exclude-include'Junio C Hamano1-10/+17
"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 Cai1-8/+10
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 Cai1-6/+10
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>
2023-04-24hash-ll.h: split out of hash.h to remove dependency on repository.hElijah Newren1-0/+1
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 Newren1-0/+1
Signed-off-by: Elijah Newren <newren@gmail.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 Newren1-0/+1
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 Newren1-0/+1
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 Newren1-0/+1
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 Newren1-0/+1
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 Newren1-1/+2
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>