To allow users of the refs namespace to check if the reference backend
requires optimization, add a new field `optimize_required` field to
`struct ref_storage_be`. This field is of type `optimize_required_fn`
which is also introduced in this commit.
Modify the debug, files, packed and reftable backend to implement this
field. A following commit will expose this via 'git pack-refs' and 'git
refs optimize'.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous commit removed all references to 'pack_refs()' within
the refs subsystem. Continue this cleanup by also renaming
'pack_refs_opts' to 'refs_optimize_opts' and the respective flags
accordingly. Keeping the naming consistent will make the code easier to
maintain.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `struct ref_store` variable exposes two ways to optimize a reftable
backend:
1. pack_refs
2. optimize
The former was specific to the 'files' + 'packed' refs backend. The
latter is more generic and covers all backends. While the naming is
different, both of these functions perform the same functionality.
Consolidate this code to only maintain the 'optimize' functions. Do this
by modifying the backends so that they exclusively implement the
`optimize` callback, only. All users of the refs subsystem already use
the 'optimize' function so there is no changes needed on the callee
side. Finally, cleanup all references to the 'pack_refs' field of the
structure and code around it.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that the peeled object ID gets propagated via the `struct reference`
there is no need anymore to call into the reference iterator itself to
dereference an object. Remove this infrastructure.
Most of the changes are straight-forward deletions of code. There is one
exception though in `refs/packed-backend.c::write_with_updates()`. Here
we stop peeling the iterator and instead just pass the peeled object ID
of that iterator directly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Both the "files" and "reftable" backend are able to store peeled values
for tags in the respective formats. This allows for a more efficient
lookup of the target object of such a tag without having to manually
peel via the object database.
The infrastructure to access these peeled object IDs is somewhat funky
though. When iterating through objects, we store a pointer reference to
the current iterator in a global variable. The callbacks invoked by that
iterator are then expected to call `peel_iterated_oid()`, which checks
whether the globally-stored iterator's current reference refers to the
one handed into that function. If so, we ask the iterator to peel the
object, otherwise we manually peel the object via the object database.
Depending on global state like this is somewhat weird and also quite
fragile.
Introduce a new `struct reference::peeled_oid` field that can be
populated by the reference backends. This field can be accessed via a
new function `reference_get_peeled_oid()` that either uses that value,
if set, or alternatively peels via the ODB. With this change we don't
have to rely on global state anymore, but make the peeled object ID
available to the callback functions directly.
Adjust trivial callers that already have a `struct reference` available.
Remaining callers will be adjusted in subsequent commits.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The reference flags encode information like whether or not a reference
is a symbolic reference or whether it may be broken. This information is
stored in a `int flags` bitfield, which is in conflict with our modern
best practices; we tend to use an unsigned integer to store flags.
Change the type of the field to be `unsigned`. While at it, refactor the
individual flags to be part of an `enum` instead of using preprocessor
defines.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `each_ref_fn` callback function type is used across our code base
for several different functions that iterate through reference. There's
a bunch of callbacks implementing this type, which makes any changes to
the callback signature extremely noisy. An example of the required churn
is e8207717f1 (refs: add referent to each_ref_fn, 2024-08-09): adding a
single argument required us to change 48 files.
It was already proposed back then [1] that we might want to introduce a
wrapper structure to alleviate the pain going forward. While this of
course requires the same kind of global refactoring as just introducing
a new parameter, it at least allows us to more change the callback type
afterwards by just extending the wrapper structure.
One counterargument to this refactoring is that it makes the structure
more opaque. While it is obvious which callsites need to be fixed up
when we change the function type, it's not obvious anymore once we use
a structure. That being said, we only have a handful of sites that
actually need to populate this wrapper structure: our ref backends,
"refs/iterator.c" as well as very few sites that invoke the iterator
callback functions directly.
Introduce this wrapper structure so that we can adapt the iterator
interfaces more readily.
[1]: <ZmarVcF5JjsZx0dl@tanuki>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git refs optimize" is added for not very well explained reason
despite it does the same thing as "git pack-refs"...
* ms/refs-optimize:
t: add test for git refs optimize subcommand
t0601: refactor tests to be shareable
builtin/refs: add optimize subcommand
doc: pack-refs: factor out common options
builtin/pack-refs: factor out core logic into a shared library
builtin/pack-refs: convert to use the generic refs_optimize() API
reftable-backend: implement 'optimize' action
files-backend: implement 'optimize' action
refs: add a generic 'optimize' API
Deal more gracefully with directory / file conflicts when the files
backend is used for ref storage, by failing only the ones that are
involved in the conflict while allowing others.
* kn/refs-files-case-insensitive:
refs/files: handle D/F conflicts during locking
refs/files: handle F/D conflicts in case-insensitive FS
refs/files: use correct error type when lock exists
refs/files: catch conflicts on case-insensitive file-systems
The existing `pack-refs` API is conceptually tied to the 'files'
backend, but its behavior is generic (e.g., it triggers compaction for
reftable). This naming is confusing.
Introduce a new generic refs_optimize() API that dispatches to a
backend-specific implementation via a new 'optimize' vtable method.
This lays the architectural groundwork for different reference backends
(like 'files' and 'reftable') to provide their own storage optimization
logic, which will be called from a single, generic entry point.
Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: shejialuo <shejialuo@gmail.com>
Signed-off-by: Meet Soni <meetsoni3017@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
During the 'prepare' phase of a reference transaction in the files
backend, we create the lock files for references to be created. When
using batched updates on case-insensitive filesystems, the entire
batched updates would be aborted if there are conflicting names such as:
refs/heads/Foo
refs/heads/foo
This affects all commands which were migrated to use batched updates in
Git 2.51, including 'git-fetch(1)' and 'git-receive-pack(1)'. Before
that, reference updates would be applied serially with one transaction
used per update. When users fetched multiple references on
case-insensitive systems, subsequent references would simply overwrite
any earlier references. So when fetching:
refs/heads/foo: 5f34ec0bfeac225b1c854340257a65b106f70ea6
refs/heads/Foo: ec3053b0977e83d9b67fc32c4527a117953994f3
refs/heads/sample: 2eefd1150e06d8fca1ddfa684dec016f36bf4e56
The user would simply end up with:
refs/heads/foo: ec3053b0977e83d9b67fc32c4527a117953994f3
refs/heads/sample: 2eefd1150e06d8fca1ddfa684dec016f36bf4e56
This is buggy behavior since the user is never informed about the
overrides performed and missing references. Nevertheless, the user is
left with a working repository with a subset of the references. Since
Git 2.51, in such situations fetches would simply fail without updating
any references. Which is also buggy behavior and worse off since the
user is left without any references.
The error is triggered in `lock_raw_ref()` where the files backend
attempts to create a lock file. When a lock file already exists the
function returns a 'REF_TRANSACTION_ERROR_GENERIC'. When this happens,
the entire batched updates, not individual operation, is aborted as if
it were in a transaction.
Change this to return 'REF_TRANSACTION_ERROR_CASE_CONFLICT' instead to
aid the batched update mechanism to simply reject such errors. The
change only affects batched updates since batched updates will reject
individual updates with non-generic errors. So specifically this would
only affect:
1. git fetch
2. git receive-pack
3. git update-ref --batch-updates
This bubbles the error type up to `files_transaction_prepare()` which
tries to lock each reference update. So if the locking fails, we check
if the rejection type can be ignored, which is done by calling
`ref_transaction_maybe_set_rejected()`.
As the error type is now 'REF_TRANSACTION_ERROR_CASE_CONFLICT',
the specific reference update would simply be rejected, while other
updates in the transaction would continue to be applied. This allows
partial application of references in case-insensitive filesystems when
fetching colliding references.
While the earlier implementation allowed the last reference to be
applied overriding the initial references, this change would allow the
first reference to be applied while rejecting consequent collisions.
This should be an okay compromise since with the files backend, there is
no scenario possible where we would retain all colliding references.
Let's also be more proactive and notify users on case-insensitive
filesystems about such problems by providing a brief about the issue
while also recommending using the reftable backend, which doesn't have
the same issue.
Reported-by: Joe Drew <joe.drew@indexexchange.com>
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git remote rename origin upstream" failed to move origin/HEAD to
upstream/HEAD when origin/HEAD is unborn and performed other
renames extremely inefficiently, which has been corrected.
* ps/remote-rename-fix:
builtin/remote: only iterate through refs that are to be renamed
builtin/remote: rework how remote refs get renamed
builtin/remote: determine whether refs need renaming early on
builtin/remote: fix sign comparison warnings
refs: simplify logic when migrating reflog entries
refs: pass refname when invoking reflog entry callback
"git refs migrate" to migrate the reflog entries from a refs
backend to another had a handful of bugs squashed.
* ps/reflog-migrate-fixes:
refs: fix invalid old object IDs when migrating reflogs
refs: stop unsetting REF_HAVE_OLD for log-only updates
refs/files: detect race when generating reflog entry for HEAD
refs: fix identity for migrated reflogs
ident: fix type of string length parameter
builtin/reflog: implement subcommand to write new entries
refs: export `ref_transaction_update_reflog()`
builtin/reflog: improve grouping of subcommands
Documentation/git-reflog: convert to use synopsis type
When renaming a remote we also need to rename all references
accordingly. But while we only need to rename references that are
contained in the "refs/remotes/$OLDNAME/" namespace, we end up using
`refs_for_each_rawref()` that iterates through _all_ references. We know
to exit early in the callback in case we see an irrelevant reference,
but ultimately this is still a waste of compute as we knowingly iterate
through references that we won't ever care about.
Improve this by using `refs_for_each_rawref_in()`, which knows to only
iterate through (potentially broken) references in a given prefix.
The following benchmark renames a remote with a single reference in a
repository that has 100k unrelated references. This shows a sizeable
improvement with the "files" backend:
Benchmark 1: rename remote (refformat = files, revision = HEAD~)
Time (mean ± σ): 42.6 ms ± 0.9 ms [User: 29.1 ms, System: 8.4 ms]
Range (min … max): 40.1 ms … 43.3 ms 10 runs
Benchmark 2: rename remote (refformat = files, revision = HEAD)
Time (mean ± σ): 31.7 ms ± 4.0 ms [User: 19.6 ms, System: 6.9 ms]
Range (min … max): 27.1 ms … 36.0 ms 10 runs
Summary
rename remote (refformat = files, revision = HEAD) ran
1.35 ± 0.17 times faster than rename remote (refformat = files, revision = HEAD~)
The "reftable" backend shows roughly the same absolute improvement, but
given that it's already significantly faster than the "files" backend
this translates to a much larger relative improvement:
Benchmark 1: rename remote (refformat = reftable, revision = HEAD~)
Time (mean ± σ): 18.2 ms ± 0.5 ms [User: 12.7 ms, System: 3.0 ms]
Range (min … max): 17.3 ms … 21.4 ms 110 runs
Benchmark 2: rename remote (refformat = reftable, revision = HEAD)
Time (mean ± σ): 8.8 ms ± 0.5 ms [User: 3.8 ms, System: 2.9 ms]
Range (min … max): 7.5 ms … 9.9 ms 167 runs
Summary
rename remote (refformat = reftable, revision = HEAD) ran
2.07 ± 0.12 times faster than rename remote (refformat = reftable, revision = HEAD~)
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With `refs_for_each_reflog_ent()` callers can iterate through all the
reflog entries for a given reference. The callback that is being invoked
for each such entry does not receive the name of the reference that we
are currently iterating through. This isn't really a limiting factor, as
callers can simply pass the name via the callback data.
But this layout sometimes does make for a bit of an awkward calling
pattern. One example: when iterating through all reflogs, and for each
reflog we iterate through all refnames, we have to do some extra book
keeping to track which reference name we are currently yielding reflog
entries for.
Change the signature of the callback function so that the reference name
of the reflog gets passed through to it. Adapt callers accordingly and
start using the new parameter in trivial cases. The next commit will
refactor the reference migration logic to make use of this parameter so
that we can simplify its logic a bit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ps/reflog-migrate-fixes:
refs: fix invalid old object IDs when migrating reflogs
refs: stop unsetting REF_HAVE_OLD for log-only updates
refs/files: detect race when generating reflog entry for HEAD
refs: fix identity for migrated reflogs
ident: fix type of string length parameter
builtin/reflog: implement subcommand to write new entries
refs: export `ref_transaction_update_reflog()`
builtin/reflog: improve grouping of subcommands
Documentation/git-reflog: convert to use synopsis type
When migrating reflog entries between different storage formats we end
up with invalid old object IDs for the migrated entries: instead of
writing the old object ID of the to-be-migrated entry, we end up with
the all-zeroes object ID.
The root cause of this issue is that we don't know to use the old object
ID provided by the caller. Instead, we manually resolve the old object
ID by resolving the current value of its matching reference. But as that
reference does not yet exist in the target ref storage we always end up
resolving it to all-zeroes.
This issue got unnoticed as there is no user-facing command that would
even show the old object ID. While `git log -g` knows to show the new
object ID, we don't have any formatting directive to show the old object
ID.
Fix the bug by introducing a new flag `REF_LOG_USE_PROVIDED_OIDS`. If
set, backends are instructed to use the old and new object IDs provided
by the caller, without doing any manual resolving. Set this flag in
`ref_transaction_update_reflog()`.
Amend our tests in t1460-refs-migrate to use our test tool to read
reflog entries. This test tool prints out both old and new object ID of
each reflog entry, which fixes the test gap. Furthermore it also prints
the full identity used to write the reflog, which provides test coverage
for the previous commit in this patch series that fixed the identity for
migrated reflogs.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a subsequent commit we'll add another user that wants to write reflog
entries. This requires them to call `ref_transaction_update_reflog()`,
but that function is local to "refs.c".
Export the function to prepare for the change. While at it, drop the
`flags` field, as all callers are for now expected to use the same flags
anyway.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git for-each-ref" learns "--start-after" option to help
applications that want to page its output.
* kn/for-each-ref-skip:
ref-cache: set prefix_state when seeking
for-each-ref: introduce a '--start-after' option
ref-filter: remove unnecessary else clause
refs: selectively set prefix in the seek functions
ref-cache: remove unused function 'find_ref_entry()'
refs: expose `ref_iterator` via 'refs.h'
"git fetch --prune" used to be O(n^2) expensive when there are many
refs, which has been corrected.
* ph/fetch-prune-optim:
clean up interface for refs_warn_dangling_symrefs
refs: remove old refs_warn_dangling_symref
fetch-prune: optimize dangling-ref reporting
The ref iterator exposes a `ref_iterator_seek()` function. The name
suggests that this would seek the iterator to a specific reference in
some ways similar to how `fseek()` works for the filesystem.
However, the function actually sets the prefix for refs iteration. So
further iteration would only yield references which match the particular
prefix. This is a bit confusing.
Let's add a 'flags' field to the function, which when set with the
'REF_ITERATOR_SEEK_SET_PREFIX' flag, will set the prefix for the
iteration in-line with the existing behavior. Otherwise, the reference
backends will simply seek to the specified reference and clears any
previously set prefix. This allows users to start iteration from a
specific reference.
In the packed and reftable backend, since references are available in a
sorted list, the changes are simply setting the prefix if needed. The
changes on the files-backend are a little more involved, since the files
backend uses the 'ref-cache' mechanism. We move out the existing logic
within `cache_ref_iterator_seek()` to `cache_ref_iterator_set_prefix()`
which is called when the 'REF_ITERATOR_SEEK_SET_PREFIX' flag is set. We
then parse the provided seek string and set the required levels and
their indexes to ensure that seeking is possible.
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `ref_iterator` is an internal structure to the 'refs/'
sub-directory, which allows iteration over refs. All reference iteration
is built on top of these iterators.
External clients of the 'refs' subsystem use the various
'refs_for_each...()' functions to iterate over refs. However since these
are wrapper functions, each combination of functionality requires a new
wrapper function. This is not feasible as the functions pile up with the
increase in requirements. Expose the internal reference iterator, so
advanced users can mix and match options as needed.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The refs_warn_dangling_symrefs interface is a bit fragile as it passes
in printf-formatting strings with expectations about the number of
arguments. This patch series made it worse by adding a 2nd positional
argument. But there are only two call sites, and they both use almost
identical display options.
Make this safer by moving the format strings into the function that uses
them to make it easier to see when the arguments don't match. Pass a
prefix string and a dry_run flag so the decision logic can be handled
where needed.
Signed-off-by: Phil Hord <phil.hord@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The dangling warning function that takes a single ref to search for
is no longer used. Remove it.
Signed-off-by: Phil Hord <phil.hord@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit 76e760b999 (refs: introduce enum-based transaction error
types, 2025-04-08) introduced enum-based transaction error types. The
refs transaction logic was also modified to propagate these errors. For
clients of the ref transaction system, it would be beneficial to provide
human readable messages for these errors.
There is already an existing mapping in 'builtin/update-ref.c', move it
to 'refs.c' as `ref_transaction_error_msg()` and use the same within the
'builtin/update-ref.c'.
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Updating multiple references have only been possible in all-or-none
fashion with transactions, but it can be more efficient to batch
multiple updates even when some of them are allowed to fail in a
best-effort manner. A new "best effort batches of updates" mode
has been introduced.
* kn/non-transactional-batch-updates:
update-ref: add --batch-updates flag for stdin mode
refs: support rejection in batch updates during F/D checks
refs: implement batch reference update support
refs: introduce enum-based transaction error types
refs/reftable: extract code from the transaction preparation
refs/files: remove duplicate duplicates check
refs: move duplicate refname update check to generic layer
refs/files: remove redundant check in split_symref_update()
The `refs_verify_refnames_available()` is used to batch check refnames
for F/D conflicts. While this is the more performant alternative than
its individual version, it does not provide rejection capabilities on a
single update level. For batched updates, this would mean a rejection of
the entire transaction whenever one reference has a F/D conflict.
Modify the function to call `ref_transaction_maybe_set_rejected()` to
check if a single update can be rejected. Since this function is only
internally used within 'refs/' and we want to pass in a `struct
ref_transaction *` as a variable. We also move and mark
`refs_verify_refnames_available()` to 'refs-internal.h' to be an
internal function.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git supports making reference updates with or without transactions.
Updates with transactions are generally better optimized. But
transactions are all or nothing. This means, if a user wants to batch
updates to take advantage of the optimizations without the hard
requirement that all updates must succeed, there is no way currently to
do so. Particularly with the reftable backend where batching multiple
reference updates is more efficient than performing them sequentially.
Introduce batched update support with a new flag,
'REF_TRANSACTION_ALLOW_FAILURE'. Batched updates while different from
transactions, use the transaction infrastructure under the hood. When
enabled, this flag allows individual reference updates that would
typically cause the entire transaction to fail due to non-system-related
errors to be marked as rejected while permitting other updates to
proceed. System errors referred by 'REF_TRANSACTION_ERROR_GENERIC'
continue to result in the entire transaction failing. This approach
enhances flexibility while preserving transactional integrity where
necessary.
The implementation introduces several key components:
- Add 'rejection_err' field to struct `ref_update` to track failed
updates with failure reason.
- Add a new struct `ref_transaction_rejections` and a field within
`ref_transaction` to this struct to allow quick iteration over
rejected updates.
- Modify reference backends (files, packed, reftable) to handle
partial transactions by using `ref_transaction_set_rejected()`
instead of failing the entire transaction when
`REF_TRANSACTION_ALLOW_FAILURE` is set.
- Add `ref_transaction_for_each_rejected_update()` to let callers
examine which updates were rejected and why.
This foundational change enables batched update support throughout the
reference subsystem. A following commit will expose this capability to
users by adding a `--batch-updates` flag to 'git-update-ref(1)',
providing both a user-facing feature and a testable implementation.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace preprocessor-defined transaction errors with a strongly-typed
enum `ref_transaction_error`. This change:
- Improves type safety and function signature clarity.
- Makes error handling more explicit and discoverable.
- Maintains existing error cases, while adding new error cases for
common scenarios.
This refactoring paves the way for more comprehensive error handling
which we will utilize in the upcoming commits to add batch reference
update support.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code paths to check whether a refname X is available (by seeing
if another ref X/Y exists, etc.) have been optimized.
* ps/refname-avail-check-optim:
refs: reuse iterators when determining refname availability
refs/iterator: implement seeking for files iterators
refs/iterator: implement seeking for packed-ref iterators
refs/iterator: implement seeking for ref-cache iterators
refs/iterator: implement seeking for reftable iterators
refs/iterator: implement seeking for merged iterators
refs/iterator: provide infrastructure to re-seek iterators
refs/iterator: separate lifecycle from iteration
refs: stop re-verifying common prefixes for availability
refs/files: batch refname availability checks for initial transactions
refs/files: batch refname availability checks for normal transactions
refs/reftable: batch refname availability checks
refs: introduce function to batch refname availability checks
builtin/update-ref: skip ambiguity checks when parsing object IDs
object-name: allow skipping ambiguity checks in `get_oid()` family
object-name: introduce `repo_get_oid_with_flags()`
The `refs_verify_refname_available()` functions checks whether a
reference update can be committed or whether it would conflict with
either a prefix or suffix thereof. This function needs to be called once
per reference that one wants to check, which requires us to redo a
couple of checks every time the function is called.
Introduce a new function `refs_verify_refnames_available()` that does
the same, but for a list of references. For now, the new function uses
the exact same implementation, except that we loop through all refnames
provided by the caller. This will be tuned in subsequent commits.
The existing `refs_verify_refname_available()` function is reimplemented
on top of the new function. As such, the diff is best viewed with the
`--ignore-space-change option`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git refs migrate" can optionally be told not to migrate the reflog.
* kn/ref-migrate-skip-reflog:
builtin/refs: add '--no-reflog' flag to drop reflogs
The "git refs migrate" subcommand converts the backend used for ref
storage. It always migrates reflog data as well as refs. Introduce an
option to exclude reflogs from migration, allowing them to be discarded
when they are unnecessary.
This is particularly useful in server-side repositories, where reflogs
are typically not expected. However, some repositories may still have
them due to historical reasons, such as bugs, misconfigurations, or
administrative decisions to enable reflogs for debugging. In such
repositories, it would be optimal to drop reflogs during the migration.
To address this, introduce the '--no-reflog' flag, which prevents reflog
migration. When this flag is used, reflogs from the original reference
backend are migrated. Since only the new reference backend remains in
the repository, all previous reflogs are permanently discarded.
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `ref_transaction_update_reflog()` function is only used within
'refs.c', so mark it as static.
Reported-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git refs migrate" learned to also migrate the reflog data across
backends.
* kn/reflog-migration:
refs: mark invalid refname message for translation
refs: add support for migrating reflogs
refs: allow multiple reflog entries for the same refname
refs: introduce the `ref_transaction_update_reflog` function
refs: add `committer_info` to `ref_transaction_add_update()`
refs: extract out refname verification in transactions
refs/files: add count field to ref_lock
refs: add `index` field to `struct ref_udpate`
refs: include committer info in `ref_update` struct
When "git fetch $remote" notices that refs/remotes/$remote/HEAD is
missing and discovers what branch the other side points with its
HEAD, refs/remotes/$remote/HEAD is updated to point to it.
* bf/set-head-symref:
fetch set_head: handle mirrored bare repositories
fetch: set remote/HEAD if it does not exist
refs: add create_only option to refs_update_symref_extended
refs: add TRANSACTION_CREATE_EXISTS error
remote set-head: better output for --auto
remote set-head: refactor for readability
refs: atomically record overwritten ref in update_symref
refs: standardize output of refs_read_symbolic_ref
t/t5505-remote: test failure of set-head
t/t5505-remote: set default branch to main
Introduce a new function `ref_transaction_update_reflog`, for clients to
add a reflog update to a transaction. While the existing function
`ref_transaction_update` also allows clients to add a reflog entry, this
function does a few things more, It:
- Enforces that only a reflog entry is added and does not update the
ref itself.
- Allows the users to also provide the committer information. This
means clients can add reflog entries with custom committer
information.
The `transaction_refname_valid()` function also modifies the error
message selectively based on the type of the update. This change also
affects reflog updates which go through `ref_transaction_update()`.
A follow up commit will utilize this function to add reflog support to
`git refs migrate`.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git tag" has been taught to refuse to create refs/tags/HEAD
as such a tag will be confusing in the context of UI provided by
the Git Porcelain commands.
* jc/forbid-head-as-tagname:
tag: "git tag" refuses to use HEAD as a tagname
t5604: do not expect that HEAD can be a valid tagname
refs: drop strbuf_ prefix from helpers
refs: move ref name helpers around
"git fsck" learned to issue warnings on "curiously formatted" ref
contents that have always been taken valid but something Git
wouldn't have written itself (e.g., missing terminating end-of-line
after the full object name).
* sj/ref-contents-check:
ref: add symlink ref content check for files backend
ref: check whether the target of the symref is a ref
ref: add basic symref content check for files backend
ref: add more strict checks for regular refs
ref: port git-fsck(1) regular refs check for files backend
ref: support multiple worktrees check for refs
ref: initialize ref name outside of check functions
ref: check the full refname instead of basename
ref: initialize "fsck_ref_report" with zero
The helper functions (strbuf_branchname, strbuf_check_branch_ref,
and strbuf_check_tag_ref) are about handling branch and tag names,
and it is a non-essential fact that these functions use strbuf to
hold these names. Rename them to make it clarify that these are
more about "ref".
Signed-off-by: Junio C Hamano <gitster@pobox.com>
strbuf_branchname(), strbuf_check_{branch,tag}_ref() are helper
functions to deal with branch and tag names, and the fact that they
happen to use strbuf to hold the name of a branch or a tag is not
essential. These functions fit better in the refs API than strbuf
API, the latter of which is about string manipulations.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `initial_transaction` flag is tracked as a signed integer, but we
typically pass around flags via unsigned integers. Adapt the type
accordingly.
Suggested-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allow the caller to specify that it only wants to update the symref if
it does not already exist. Silently ignore the error from the
transaction API if the symref already exists.
Signed-off-by: Bence Ferdinandy <bence@ferdinandy.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently there is only one special error for transaction, for when
there is a naming conflict, all other errors are dumped under a generic
error. Add a new special error case for when the caller requests the
reference to be updated only when it does not yet exist and the
reference actually does exist.
Signed-off-by: Bence Ferdinandy <bence@ferdinandy.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When updating a symref with update_symref it's currently not possible to
know for sure what was the previous value that was overwritten. Extend
refs_update_symref under a new function name, to record the value after
the ref has been locked if the caller of refs_update_symref_extended
requests it via a new variable in the function call. Make the return
value of the function notify the caller, if the previous value was
actually not a symbolic reference. Keep the original refs_update_symref
function with the same signature, but now as a wrapper around
refs_update_symref_extended.
Signed-off-by: Bence Ferdinandy <bence@ferdinandy.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the symbolic reference we want to read with refs_read_symbolic_ref
is actually not a symbolic reference, the files and the reftable
backends return different values (1 and -1 respectively). Standardize
the returned values so that 0 is success, -1 is a generic error and -2
is that the reference was actually non-symbolic.
Signed-off-by: Bence Ferdinandy <bence@ferdinandy.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have already set up the infrastructure to check the consistency for
refs, but we do not support multiple worktrees. However, "git-fsck(1)"
will check the refs of worktrees. As we decide to get feature parity
with "git-fsck(1)", we need to set up support for multiple worktrees.
Because each worktree has its own specific refs, instead of just showing
the users "refs/worktree/foo", we need to display the full name such as
"worktrees/<id>/refs/worktree/foo". So we should know the id of the
worktree to get the full name. Add a new parameter "struct worktree *"
for "refs-internal.h::fsck_fn". Then change the related functions to
follow this new interface.
The "packed-refs" only exists in the main worktree, so we should only
check "packed-refs" in the main worktree. Use "is_main_worktree" method
to skip checking "packed-refs" in "packed_fsck" function.
Then, enhance the "files-backend.c::files_fsck_refs_dir" function to add
"worktree/<id>/" prefix when we are not in the main worktree.
Last, add a new test to check the refname when there are multiple
worktrees to exercise the code.
Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: shejialuo <shejialuo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reference transactions use `refs_verify_refname_available()` to check
for colliding references. This check consists of two parts:
- Checks for whether multiple ref updates in the same transaction
conflict with each other.
- Checks for whether existing refs conflict with any refs part of the
transaction.
While we generally cannot avoid the first check, the second check is
superfluous in cases where the transaction is an initial one in an
otherwise empty ref store. The check results in multiple ref reads as
well as the creation of a ref iterator for every ref we're checking,
which adds up quite fast when performing the check for many refs.
Introduce a new flag that allows us to skip this check and wire it up in
such that the backends pass it when running an initial transaction. This
leads to significant speedups when migrating ref storage backends. From
"files" to "reftable":
Benchmark 1: migrate files:reftable (refcount = 100000, revision = HEAD~)
Time (mean ± σ): 472.4 ms ± 6.7 ms [User: 175.9 ms, System: 285.2 ms]
Range (min … max): 463.5 ms … 483.2 ms 10 runs
Benchmark 2: migrate files:reftable (refcount = 100000, revision = HEAD)
Time (mean ± σ): 86.1 ms ± 1.9 ms [User: 67.9 ms, System: 16.0 ms]
Range (min … max): 82.9 ms … 90.9 ms 29 runs
Summary
migrate files:reftable (refcount = 100000, revision = HEAD) ran
5.48 ± 0.15 times faster than migrate files:reftable (refcount = 100000, revision = HEAD~)
And from "reftable" to "files":
Benchmark 1: migrate reftable:files (refcount = 100000, revision = HEAD~)
Time (mean ± σ): 452.7 ms ± 3.4 ms [User: 209.9 ms, System: 235.4 ms]
Range (min … max): 445.9 ms … 457.5 ms 10 runs
Benchmark 2: migrate reftable:files (refcount = 100000, revision = HEAD)
Time (mean ± σ): 95.2 ms ± 2.2 ms [User: 73.6 ms, System: 20.6 ms]
Range (min … max): 91.7 ms … 100.8 ms 28 runs
Summary
migrate reftable:files (refcount = 100000, revision = HEAD) ran
4.76 ± 0.11 times faster than migrate reftable:files (refcount = 100000, revision = HEAD~)
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
