Commit Graph

379 Commits (a8dda1af6ab400d45b7524bc46b64e04d14fc912)

Author SHA1 Message Date
Junio C Hamano 6f8ae955bd Merge branch 'kn/reflog-migration'
"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
2024-12-23 09:32:29 -08:00
Junio C Hamano 5f212684ab Merge branch 'bf/set-head-symref'
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
2024-12-19 10:58:27 -08:00
Karthik Nayak 84675fa271 refs: introduce the `ref_transaction_update_reflog` function
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>
2024-12-16 09:45:34 -08:00
Junio C Hamano ab738b2f1f Merge branch 'jc/forbid-head-as-tagname'
"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
2024-12-15 17:54:26 -08:00
Junio C Hamano 57e81b59f3 Merge branch 'sj/ref-contents-check'
"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
2024-12-04 10:14:42 +09:00
Junio C Hamano 93e5e048f8 refs: drop strbuf_ prefix from helpers
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>
2024-12-03 12:38:49 +09:00
Junio C Hamano 5bcbde9e49 refs: move ref name helpers around
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>
2024-12-03 12:38:49 +09:00
Patrick Steinhardt 0f5762b043 refs: adapt `initial_transaction` flag to be unsigned
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>
2024-11-26 08:39:38 +09:00
Bence Ferdinandy 9963746c84 refs: add create_only option to refs_update_symref_extended
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>
2024-11-25 11:46:36 +09:00
Bence Ferdinandy ed2f6f8804 refs: add TRANSACTION_CREATE_EXISTS error
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>
2024-11-25 11:46:36 +09:00
Bence Ferdinandy d842cd1301 refs: atomically record overwritten ref in update_symref
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>
2024-11-25 11:46:35 +09:00
Bence Ferdinandy 8102d10ff8 refs: standardize output of refs_read_symbolic_ref
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>
2024-11-25 11:46:35 +09:00
shejialuo 7c78d819e6 ref: support multiple worktrees check for refs
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>
2024-11-21 08:21:32 +09:00
Patrick Steinhardt e4929cdf79 refs: skip collision checks in initial transactions
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>
2024-11-21 07:59:16 +09:00
Patrick Steinhardt 1c299d03e5 refs: introduce "initial" transaction flag
There are two different ways to commit a transaction:

  - `ref_transaction_commit()` can be used to commit a regular
    transaction and is what almost every caller wants.

  - `initial_ref_transaction_commit()` can be used when it is known that
    the ref store that the transaction is committed for is empty and
    when there are no concurrent processes. This is used when cloning a
    new repository.

Implementing this via two separate functions has a couple of downsides.
First, every reference backend needs to implement a separate callback
even in the case where they don't special-case the initial transaction.
Second, backends are basically forced to reimplement the whole logic for
how to commit the transaction like the "files" backend does, even though
backends may wish to only tweak certain behaviour of a "normal" commit.
Third, it is awkward that callers must never prepare the transaction as
this is somewhat different than how a transaction typically works.

Refactor the code such that we instead mark initial transactions via a
separate flag when starting the transaction. This addresses all of the
mentioned painpoints, where the most important part is that it will
allow backends to have way more leeway in how exactly they want to
handle the initial transaction.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-11-21 07:59:15 +09:00
Patrick Steinhardt a0efef1446 refs: allow passing flags when setting up a transaction
Allow passing flags when setting up a transaction such that the
behaviour of the transaction itself can be altered. This functionality
will be used in a subsequent patch.

Adapt callers accordingly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-11-21 07:59:14 +09:00
Junio C Hamano 78ce6660bb Merge branch 'ak/typofix-2.46-maint'
Typofix.

* ak/typofix-2.46-maint:
  upload-pack: fix a typo
  sideband: fix a typo
  setup: fix a typo
  run-command: fix a typo
  revision: fix a typo
  refs: fix typos
  rebase: fix a typo
  read-cache-ll: fix a typo
  pretty: fix a typo
  object-file: fix a typo
  merge-ort: fix typos
  merge-ll: fix a typo
  http: fix a typo
  gpg-interface: fix a typo
  git-p4: fix typos
  git-instaweb: fix a typo
  fsmonitor-settings: fix a typo
  diffcore-rename: fix typos
  config.mak.dev: fix a typo
2024-09-25 10:37:12 -07:00
Junio C Hamano 52f57e94bd Merge branch 'ps/reftable-exclude'
The reftable backend learned to more efficiently handle exclude
patterns while enumerating the refs.

* ps/reftable-exclude:
  refs/reftable: wire up support for exclude patterns
  reftable/reader: make table iterator reseekable
  t/unit-tests: introduce reftable library
  Makefile: stop listing test library objects twice
  builtin/receive-pack: fix exclude patterns when announcing refs
  refs: properly apply exclude patterns to namespaced refs
2024-09-25 10:37:11 -07:00
Andrew Kreimer 619cbc01a3 refs: fix typos
Fix typos in comments.

Signed-off-by: Andrew Kreimer <algonell@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-19 13:46:12 -07:00
Patrick Steinhardt 155dc8447d refs: properly apply exclude patterns to namespaced refs
Reference namespaces allow commands like git-upload-pack(1) to serve
different sets of references to the client depending on which namespace
is enabled, which is for example useful in fork networks. Namespaced
refs are stored with a `refs/namespaces/$namespace` prefix, but all the
user will ultimately see is a stripped version where that prefix is
removed.

The way that this interacts with "transfer.hideRefs" is not immediately
obvious: the hidden refs can either apply to the stripped references, or
to the non-stripped ones that still have the namespace prefix. In fact,
the "transfer.hideRefs" machinery does the former and applies to the
stripped reference by default, but rules can have "^" prefixed to switch
this behaviour to instead match against the full reference name.

Namespaces are exclusively handled at the generic "refs" layer, the
respective backends have no clue that such a thing even exists. This
also has the consequence that they cannot handle hiding references as
soon as reference namespaces come into play because they neither know
whether a namespace is active, nor do they know how to strip references
if they are active.

Handling such exclude patterns in `refs_for_each_namespaced_ref()` and
`refs_for_each_fullref_in_prefixes()` is broken though, as both support
that the user passes both namespaces and exclude patterns. In the case
where both are set we will exclude references with unstripped names,
even though we really wanted to exclude references based on their
stripped names.

This only surfaces when:

  - A repository uses reference namespaces.

  - "transfer.hideRefs" is active.

  - The namespaced references are packed into the "packed-refs" file.

None of our tests exercise this scenario, and thus we haven't ever hit
it. While t5509 exercises both (1) and (2), it does not happen to hit
(3). It is trivial to demonstrate the bug though by explicitly packing
refs in the tests, and then we indeed surface the breakage.

Fix this bug by prefixing exclude patterns with the namespace in the
generic layer. The newly introduced function will be used outside of
"refs.c" in the next patch, so we add a declaration to "refs.h".

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-16 13:57:18 -07:00
Patrick Steinhardt 9a20b889e8 refs: stop modifying global `log_all_ref_updates` variable
In refs-related code we modify the global `log_all_ref_updates`
variable, which is done because `should_autocreate_reflog()` does not
accept passing an `enum log_refs_config` but instead accesses the global
variable. Adapt its interface such that the value is provided by the
caller, which allows us to compute the proper value locally without
having to modify global state.

This change requires us to move the enum to "repo-settings.h", or
otherwise we get compilation errors due to include cycles. We're about
to fully move this setting into the repo-settings subsystem anyway, so
this is fine.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-12 10:15:43 -07:00
Junio C Hamano b3d175409d Merge branch 'sj/ref-fsck'
"git fsck" infrastructure has been taught to also check the sanity
of the ref database, in addition to the object database.

* sj/ref-fsck:
  fsck: add ref name check for files backend
  files-backend: add unified interface for refs scanning
  builtin/refs: add verify subcommand
  refs: set up ref consistency check infrastructure
  fsck: add refs report function
  fsck: add a unified interface for reporting fsck messages
  fsck: make "fsck_error" callback generic
  fsck: rename objects-related fsck error functions
  fsck: rename "skiplist" to "skip_oids"
2024-08-16 12:51:51 -07:00
Junio C Hamano e7f86cb69d Merge branch 'jc/refs-symref-referent'
The refs API has been taught to give symref target information to
the users of ref iterators, allowing for-each-ref and friends to
avoid an extra ref_resolve_* API call per a symbolic ref.

* jc/refs-symref-referent:
  ref-filter: populate symref from iterator
  refs: add referent to each_ref_fn
  refs: keep track of unresolved reference value in iterators
2024-08-15 13:22:15 -07:00
John Cai e8207717f1 refs: add referent to each_ref_fn
Add a parameter to each_ref_fn so that callers to the ref APIs
that use this function as a callback can have acess to the
unresolved value of a symbolic ref.

Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-09 08:47:34 -07:00
shejialuo ab6f79d8df refs: set up ref consistency check infrastructure
The "struct ref_store" is the base class which contains the "be" pointer
which provides backend-specific functions whose interfaces are defined
in the "ref_storage_be". We could reuse this polymorphism to define only
one interface. For every backend, we need to provide its own function
pointer.

The interfaces defined in the `ref_storage_be` are carefully structured
in semantic. It's organized as the five parts:

1. The name and the initialization interfaces.
2. The ref transaction interfaces.
3. The ref internal interfaces (pack, rename and copy).
4. The ref filesystem interfaces.
5. The reflog related interfaces.

To keep consistent with the git-fsck(1), add a new interface named
"fsck_refs_fn" to the end of "ref_storage_be". This semantic cannot be
grouped into any above five categories. Explicitly add blank line to
make it different from others.

Last, implement placeholder functions for each ref backends.

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>
2024-08-08 09:36:53 -07:00
Patrick Steinhardt 91d351ec88 refs: drop `ref_store`-less functions
In c8f815c208 (refs: remove functions without ref store, 2024-05-07), we
have removed functions of the refs subsystem that do not take a ref
store as input parameter. In order to make it easier for folks to figure
out how to replace calls to such functions in in-flight patch series, we
kept their definitions around in an ifdeffed block.

Now that Git v2.46 is out, it is rather unlikely that anybody still has
references to these old functions in their unreleased patches. Let's
thus drop them.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-02 08:54:32 -07:00
Junio C Hamano f9e4f2599c Merge branch 'ch/refs-without-the-repository-fix'
Comment fix.

* ch/refs-without-the-repository-fix:
  refs: correct the version numbers in a comment
2024-07-18 08:30:25 -07:00
Christian Hesse 730914ed7e refs: correct the version numbers in a comment
The paragraph talks about a change made in c8f815c2 (refs: remove
functions without ref store, 2024-05-07), which is v2.46.0-rc0~119^2
and will be published as part of v2.46, not v2.45.

Signed-off-by: Christian Hesse <mail@eworm.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-07-16 09:06:22 -07:00
Junio C Hamano 7b472da915 Merge branch 'ps/use-the-repository'
A CPP macro USE_THE_REPOSITORY_VARIABLE is introduced to help
transition the codebase to rely less on the availability of the
singleton the_repository instance.

* ps/use-the-repository:
  hex: guard declarations with `USE_THE_REPOSITORY_VARIABLE`
  t/helper: remove dependency on `the_repository` in "proc-receive"
  t/helper: fix segfault in "oid-array" command without repository
  t/helper: use correct object hash in partial-clone helper
  compat/fsmonitor: fix socket path in networked SHA256 repos
  replace-object: use hash algorithm from passed-in repository
  protocol-caps: use hash algorithm from passed-in repository
  oidset: pass hash algorithm when parsing file
  http-fetch: don't crash when parsing packfile without a repo
  hash-ll: merge with "hash.h"
  refs: avoid include cycle with "repository.h"
  global: introduce `USE_THE_REPOSITORY_VARIABLE` macro
  hash: require hash algorithm in `empty_tree_oid_hex()`
  hash: require hash algorithm in `is_empty_{blob,tree}_oid()`
  hash: make `is_null_oid()` independent of `the_repository`
  hash: convert `oidcmp()` and `oideq()` to compare whole hash
  global: ensure that object IDs are always padded
  hash: require hash algorithm in `oidread()` and `oidclr()`
  hash: require hash algorithm in `hasheq()`, `hashcmp()` and `hashclr()`
  hash: drop (mostly) unused `is_empty_{blob,tree}_sha1()` functions
2024-07-02 09:59:00 -07:00
Junio C Hamano 5f14d20984 Merge branch 'kn/update-ref-symref'
"git update-ref --stdin" learned to handle transactional updates of
symbolic-refs.

* kn/update-ref-symref:
  update-ref: add support for 'symref-update' command
  reftable: pick either 'oid' or 'target' for new updates
  update-ref: add support for 'symref-create' command
  update-ref: add support for 'symref-delete' command
  update-ref: add support for 'symref-verify' command
  refs: specify error for regular refs with `old_target`
  refs: create and use `ref_update_expects_existing_old_ref()`
2024-06-20 15:45:12 -07:00
Junio C Hamano 4216329457 Merge branch 'ps/no-writable-strings'
Building with "-Werror -Wwrite-strings" is now supported.

* ps/no-writable-strings: (27 commits)
  config.mak.dev: enable `-Wwrite-strings` warning
  builtin/merge: always store allocated strings in `pull_twohead`
  builtin/rebase: always store allocated string in `options.strategy`
  builtin/rebase: do not assign default backend to non-constant field
  imap-send: fix leaking memory in `imap_server_conf`
  imap-send: drop global `imap_server_conf` variable
  mailmap: always store allocated strings in mailmap blob
  revision: always store allocated strings in output encoding
  remote-curl: avoid assigning string constant to non-const variable
  send-pack: always allocate receive status
  parse-options: cast long name for OPTION_ALIAS
  http: do not assign string constant to non-const field
  compat/win32: fix const-correctness with string constants
  pretty: add casts for decoration option pointers
  object-file: make `buf` parameter of `index_mem()` a constant
  object-file: mark cached object buffers as const
  ident: add casts for fallback name and GECOS
  entry: refactor how we remove items for delayed checkouts
  line-log: always allocate the output prefix
  line-log: stop assigning string constant to file parent buffer
  ...
2024-06-17 15:55:58 -07:00
Patrick Steinhardt 36026a0f30 refs: avoid include cycle with "repository.h"
There is an include cycle between "refs.h" and "repository.h" via
"commit.h", "object.h" and "hash.h". This has the effect that several
definitions of structs and enums will not be visible once we merge
"hash-ll.h" back into "hash.h" in the next commit.

The only reason that "repository.h" includes "refs.h" is the definition
of `enum ref_storage_format`. Move it into "repository.h" and have
"refs.h" include "repository.h" instead to fix the cycle.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 10:26:33 -07:00
Patrick Steinhardt b567004b4b global: improve const correctness when assigning string constants
We're about to enable `-Wwrite-strings`, which changes the type of
string constants to `const char[]`. Fix various sites where we assign
such constants to non-const variables.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-07 10:30:48 -07:00
Karthik Nayak ed3272720e update-ref: add support for 'symref-create' command
Add 'symref-create' command to the '--stdin' mode 'git-update-ref' to
allow creation of symbolic refs in a transaction. The 'symref-create'
command takes in a <new-target>, which the created <ref> will point to.

Also, support the 'core.prefersymlinkrefs' config, wherein if the config
is set and the filesystem supports symlinks, we create the symbolic ref
as a symlink. We fallback to creating a regular symref if creating the
symlink is unsuccessful.

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>
2024-06-07 10:25:45 -07:00
Karthik Nayak 2343720967 update-ref: add support for 'symref-delete' command
Add a new command 'symref-delete' to allow deletions of symbolic refs in
a transaction via the '--stdin' mode of the 'git-update-ref' command.
The 'symref-delete' command can, when given an <old-target>, delete the
provided <ref> only when it points to <old-target>.

This command is only compatible with the 'no-deref' mode because we
optionally want to check the 'old_target' of the ref being deleted.
De-referencing a symbolic ref would provide a regular ref and we already
have the 'delete' command for regular refs.

While users can also use 'git symbolic-ref -d' to delete symbolic refs,
the 'symref-delete' command in 'git-update-ref' allows users to do so
within a transaction, which promises atomicity of the operation and can
be batched with other commands.

When no 'old_target' is provided it can also delete regular refs,
similar to how the 'delete' command can delete symrefs when no 'old_oid'
is provided.

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>
2024-06-07 10:25:44 -07:00
Karthik Nayak 1451ac734f update-ref: add support for 'symref-verify' command
The 'symref-verify' command allows users to verify if a provided <ref>
contains the provided <old-target> without changing the <ref>. If
<old-target> is not provided, the command will verify that the <ref>
doesn't exist.

The command allows users to verify symbolic refs within a transaction,
and this means users can perform a set of changes in a transaction only
when the verification holds good.

Since we're checking for symbolic refs, this command will only work with
the 'no-deref' mode. This is because any dereferenced symbolic ref will
point to an object and not a ref and the regular 'verify' command can be
used in such situations.

Add required tests for symref support in 'verify'. Since we're here,
also add reflog checks for the pre-existing 'verify' tests, there is no
divergence from behavior, but we never tested to ensure that reflog
wasn't affected by the 'verify' command.

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>
2024-06-07 10:25:44 -07:00
Patrick Steinhardt 6d6a3a99c7 refs: implement logic to migrate between ref storage formats
With the introduction of the new "reftable" backend, users may want to
migrate repositories between the backends without having to recreate the
whole repository. Add the logic to do so.

The implementation is generic and works with arbitrary ref storage
formats so that a backend does not need to implement any migration
logic. It does have a few limitations though:

  - We do not migrate repositories with worktrees, because worktrees
    have separate ref storages. It makes the overall affair more complex
    if we have to migrate multiple storages at once.

  - We do not migrate reflogs, because we have no interfaces to write
    many reflog entries.

  - We do not lock the repository for concurrent access, and thus
    concurrent writes may end up with weird in-between states. There is
    no way to fully lock the "files" backend for writes due to its
    format, and thus we punt on this topic altogether and defer to the
    user to avoid those from happening.

In other words, this version is a minimum viable product for migrating a
repository's ref storage format. It works alright for bare repos, which
often have neither worktrees nor reflogs. But it will not work for many
other repositories without some preparations. These limitations are not
set into stone though, and ideally we will eventually address them over
time.

The logic is not yet used by anything, and thus there are no tests for
it. Those will be added in the next commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-06 09:04:33 -07:00
Patrick Steinhardt 64a6dd8ffc refs: implement removal of ref storages
We're about to introduce logic to migrate ref storages. One part of the
migration will be to delete the files that are part of the old ref
storage format. We don't yet have a way to delete such data generically
across ref backends though.

Implement a new `delete` callback and expose it via a new
`ref_storage_delete()` function.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-06 09:04:33 -07:00
Patrick Steinhardt fbd1a693c7 refs: allow to skip creation of reflog entries
The ref backends do not have any way to disable the creation of reflog
entries. This will be required for upcoming ref format migration logic
so that we do not create any entries that didn't exist in the original
ref database.

Provide a new `REF_SKIP_CREATE_REFLOG` flag that allows the caller to
disable reflog entry creation.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-06 09:04:31 -07:00
Patrick Steinhardt 318efb966b refs: convert ref storage format to an enum
The ref storage format is tracked as a simple unsigned integer, which
makes it harder than necessary to discover what that integer actually is
or where its values are defined.

Convert the ref storage format to instead be an enum.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-06 09:04:31 -07:00
Junio C Hamano 16a592f132 Merge branch 'ps/pseudo-ref-terminology'
Terminology to call various ref-like things are getting
straightened out.

* 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
2024-05-28 11:17:06 -07:00
Junio C Hamano 0ff6d23a0f Merge branch 'ps/pseudo-ref-terminology' into ps/ref-storage-migration
* 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
2024-05-23 09:14:32 -07:00
Junio C Hamano e55f364398 Merge branch 'ps/refs-without-the-repository-updates' into 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
2024-05-23 09:14:08 -07:00
Junio C Hamano 4beb7a3b06 Merge branch 'kn/ref-transaction-symref'
Updates to symbolic refs can now be made as a part of ref
transaction.

* kn/ref-transaction-symref:
  refs: remove `create_symref` and associated dead code
  refs: rename `refs_create_symref()` to `refs_update_symref()`
  refs: use transaction in `refs_create_symref()`
  refs: add support for transactional symref updates
  refs: move `original_update_refname` to 'refs.c'
  refs: support symrefs in 'reference-transaction' hook
  files-backend: extract out `create_symref_lock()`
  refs: accept symref values in `ref_transaction_update()`
2024-05-20 11:20:04 -07:00
Patrick Steinhardt 2bb444b196 refs: remove `dwim_log()`
Remove `dwim_log()` in favor of `repo_dwim_log()` so that we can get rid
of one more dependency on `the_repository`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17 10:33:39 -07:00
Patrick Steinhardt 97abaab5f6 refs: drop `git_default_branch_name()`
The `git_default_branch_name()` function is a thin wrapper around
`repo_default_branch_name()` with two differences:

  - We implicitly rely on `the_repository`.

  - We cache the default branch name.

None of the callsites of `git_default_branch_name()` are hot code paths
though, so the caching of the branch name is not really required.

Refactor the callsites to use `repo_default_branch_name()` instead and
drop `git_default_branch_name()`, thus getting rid of one more case
where we rely on `the_repository`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17 10:33:39 -07:00
Patrick Steinhardt 30aaff437f refs: pass repo when peeling objects
Both `peel_object()` and `peel_iterated_oid()` implicitly rely on
`the_repository` to look up objects. Despite the fact that we want to
get rid of `the_repository`, it also leads to some restrictions in our
ref iterators when trying to retrieve the peeled value for a repository
other than `the_repository`.

Refactor these functions such that both take a repository as argument
and remove the now-unnecessary restrictions.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17 10:33:39 -07:00
Patrick Steinhardt 330a2ae60b refs: pass ref store when detecting dangling symrefs
Both `warn_dangling_symref()` and `warn_dangling_symrefs()` derive the
ref store via `the_repository`. Adapt them to instead take in the ref
store as a parameter. While at it, rename the functions to have a `ref_`
prefix to align them with other functions that take a ref store.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17 10:33:38 -07:00
Patrick Steinhardt 8378c9d27b refs: convert iteration over replace refs to accept ref store
The function `for_each_replace_ref()` is a bit of an oddball across the
refs interfaces as it accepts a pointer to the repository instead of a
pointer to the ref store. The only reason for us to accept a repository
is so that we can eventually pass it back to the callback function that
the caller has provided. This is somewhat arbitrary though, as callers
that need the repository can instead make it accessible via the callback
payload.

Refactor the function to instead accept the ref store and adjust callers
accordingly. This allows us to get rid of some of the boilerplate that
we had to carry to pass along the repository and brings us in line with
the other functions that iterate through refs.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17 10:33:38 -07:00
Patrick Steinhardt e19488a60a refs: refactor `resolve_gitlink_ref()` to accept a repository
In `resolve_gitlink_ref()` we implicitly rely on `the_repository` to
look up the submodule ref store. Now that we can look up submodule ref
stores for arbitrary repositories we can improve this function to
instead accept a repository as parameter for which we want to resolve
the gitlink.

Do so and adjust callers accordingly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17 10:33:38 -07:00