1 #ifndef REFS_REFS_INTERNAL_H
2 #define REFS_REFS_INTERNAL_H
8 struct ref_transaction
;
11 * Data structures and functions for the internal use of the refs
12 * module. Code outside of the refs module should use only the public
13 * functions defined in "refs.h", and should *not* include this file.
17 * The following flags can appear in `ref_update::flags`. Their
18 * numerical values must not conflict with those of REF_NO_DEREF and
19 * REF_FORCE_CREATE_REFLOG, which are also stored in
20 * `ref_update::flags`.
24 * The reference should be updated to new_oid.
26 #define REF_HAVE_NEW (1 << 2)
29 * The current reference's value should be checked to make sure that
30 * it agrees with old_oid.
32 #define REF_HAVE_OLD (1 << 3)
35 * Used as a flag in ref_update::flags when we want to log a ref
36 * update but not actually perform it. This is used when a symbolic
37 * ref update is split up.
39 #define REF_LOG_ONLY (1 << 7)
42 * Return the length of time to retry acquiring a loose reference lock
43 * before giving up, in milliseconds:
45 long get_files_ref_lock_timeout_ms(void);
48 * Return true iff refname is minimally safe. "Safe" here means that
49 * deleting a loose reference by this name will not do any damage, for
50 * example by causing a file that is not a reference to be deleted.
51 * This function does not check that the reference name is legal; for
52 * that, use check_refname_format().
54 * A refname that starts with "refs/" is considered safe iff it
55 * doesn't contain any "." or ".." components or consecutive '/'
56 * characters, end with '/', or (on Windows) contain any '\'
57 * characters. Names that do not start with "refs/" are considered
58 * safe iff they consist entirely of upper case characters and '_'
59 * (like "HEAD" and "MERGE_HEAD" but not "config" or "FOO/BAR").
61 int refname_is_safe(const char *refname
);
64 * Helper function: return true if refname, which has the specified
65 * oid and flags, can be resolved to an object in the database. If the
66 * referred-to object does not exist, emit a warning and return false.
68 int ref_resolves_to_object(const char *refname
,
69 struct repository
*repo
,
70 const struct object_id
*oid
,
74 /* object was peeled successfully: */
78 * object cannot be peeled because the named object (or an
79 * object referred to by a tag in the peel chain), does not
84 /* object cannot be peeled because it is not a tag: */
87 /* ref_entry contains no peeled value because it is a symref: */
91 * ref_entry cannot be peeled because it is broken (i.e., the
92 * symbolic reference cannot even be resolved to an object
99 * Peel the named object; i.e., if the object is a tag, resolve the
100 * tag recursively until a non-tag is found. If successful, store the
101 * result to oid and return PEEL_PEELED. If the object is not a tag
102 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
103 * and leave oid unchanged.
105 enum peel_status
peel_object(const struct object_id
*name
, struct object_id
*oid
);
108 * Information needed for a single ref update. Set new_oid to the new
109 * value or to null_oid to delete the ref. To check the old value
110 * while the ref is locked, set (flags & REF_HAVE_OLD) and set old_oid
111 * to the old value, or to null_oid to ensure the ref does not exist
116 * If (flags & REF_HAVE_NEW), set the reference to this value
117 * (or delete it, if `new_oid` is `null_oid`).
119 struct object_id new_oid
;
122 * If (flags & REF_HAVE_OLD), check that the reference
123 * previously had this value (or didn't previously exist, if
124 * `old_oid` is `null_oid`).
126 struct object_id old_oid
;
129 * One or more of REF_NO_DEREF, REF_FORCE_CREATE_REFLOG,
130 * REF_HAVE_NEW, REF_HAVE_OLD, or backend-specific flags.
139 * If this ref_update was split off of a symref update via
140 * split_symref_update(), then this member points at that
141 * update. This is used for two purposes:
142 * 1. When reporting errors, we report the refname under which
143 * the update was originally requested.
144 * 2. When we read the old value of this reference, we
145 * propagate it back to its parent update for recording in
146 * the latter's reflog.
148 struct ref_update
*parent_update
;
150 const char refname
[FLEX_ARRAY
];
153 int refs_read_raw_ref(struct ref_store
*ref_store
, const char *refname
,
154 struct object_id
*oid
, struct strbuf
*referent
,
155 unsigned int *type
, int *failure_errno
);
158 * Write an error to `err` and return a nonzero value iff the same
159 * refname appears multiple times in `refnames`. `refnames` must be
160 * sorted on entry to this function.
162 int ref_update_reject_duplicates(struct string_list
*refnames
,
166 * Add a ref_update with the specified properties to transaction, and
167 * return a pointer to the new object. This function does not verify
168 * that refname is well-formed. new_oid and old_oid are only
169 * dereferenced if the REF_HAVE_NEW and REF_HAVE_OLD bits,
170 * respectively, are set in flags.
172 struct ref_update
*ref_transaction_add_update(
173 struct ref_transaction
*transaction
,
174 const char *refname
, unsigned int flags
,
175 const struct object_id
*new_oid
,
176 const struct object_id
*old_oid
,
180 * Transaction states.
182 * OPEN: The transaction is initialized and new updates can still be
183 * added to it. An OPEN transaction can be prepared,
184 * committed, freed, or aborted (freeing and aborting an open
185 * transaction are equivalent).
187 * PREPARED: ref_transaction_prepare(), which locks all of the
188 * references involved in the update and checks that the
189 * update has no errors, has been called successfully for the
190 * transaction. A PREPARED transaction can be committed or
193 * CLOSED: The transaction is no longer active. A transaction becomes
194 * CLOSED if there is a failure while building the transaction
195 * or if a transaction is committed or aborted. A CLOSED
196 * transaction can only be freed.
198 enum ref_transaction_state
{
199 REF_TRANSACTION_OPEN
= 0,
200 REF_TRANSACTION_PREPARED
= 1,
201 REF_TRANSACTION_CLOSED
= 2
205 * Data structure for holding a reference transaction, which can
206 * consist of checks and updates to multiple references, carried out
207 * as atomically as possible. This structure is opaque to callers.
209 struct ref_transaction
{
210 struct ref_store
*ref_store
;
211 struct ref_update
**updates
;
214 enum ref_transaction_state state
;
219 * Check for entries in extras that are within the specified
220 * directory, where dirname is a reference directory name including
221 * the trailing slash (e.g., "refs/heads/foo/"). Ignore any
222 * conflicting references that are found in skip. If there is a
223 * conflicting reference, return its name.
225 * extras and skip must be sorted lists of reference names. Either one
226 * can be NULL, signifying the empty list.
228 const char *find_descendant_ref(const char *dirname
,
229 const struct string_list
*extras
,
230 const struct string_list
*skip
);
232 /* We allow "recursive" symbolic refs. Only within reason, though */
233 #define SYMREF_MAXDEPTH 5
236 * These flags are passed to refs_ref_iterator_begin() (and do_for_each_ref(),
239 enum do_for_each_ref_flags
{
241 * Include broken references in a do_for_each_ref*() iteration, which
242 * would normally be omitted. This includes both refs that point to
243 * missing objects (a true repository corruption), ones with illegal
244 * names (which we prefer not to expose to callers), as well as
245 * dangling symbolic refs (i.e., those that point to a non-existent
246 * ref; this is not a corruption, but as they have no valid oid, we
247 * omit them from normal iteration results).
249 DO_FOR_EACH_INCLUDE_BROKEN
= (1 << 0),
252 * Only include per-worktree refs in a do_for_each_ref*() iteration.
253 * Normally this will be used with a files ref_store, since that's
254 * where all reference backends will presumably store their
257 DO_FOR_EACH_PER_WORKTREE_ONLY
= (1 << 1),
260 * Omit dangling symrefs from output; this only has an effect with
261 * INCLUDE_BROKEN, since they are otherwise not included at all.
263 DO_FOR_EACH_OMIT_DANGLING_SYMREFS
= (1 << 2),
267 * Reference iterators
269 * A reference iterator encapsulates the state of an in-progress
270 * iteration over references. Create an instance of `struct
271 * ref_iterator` via one of the functions in this module.
273 * A freshly-created ref_iterator doesn't yet point at a reference. To
274 * advance the iterator, call ref_iterator_advance(). If successful,
275 * this sets the iterator's refname, oid, and flags fields to describe
276 * the next reference and returns ITER_OK. The data pointed at by
277 * refname and oid belong to the iterator; if you want to retain them
278 * after calling ref_iterator_advance() again or calling
279 * ref_iterator_abort(), you must make a copy. When the iteration has
280 * been exhausted, ref_iterator_advance() releases any resources
281 * associated with the iteration, frees the ref_iterator object, and
282 * returns ITER_DONE. If you want to abort the iteration early, call
283 * ref_iterator_abort(), which also frees the ref_iterator object and
284 * any associated resources. If there was an internal error advancing
285 * to the next entry, ref_iterator_advance() aborts the iteration,
286 * frees the ref_iterator, and returns ITER_ERROR.
288 * The reference currently being looked at can be peeled by calling
289 * ref_iterator_peel(). This function is often faster than peel_ref(),
290 * so it should be preferred when iterating over references.
292 * Putting it all together, a typical iteration looks like this:
295 * struct ref_iterator *iter = ...;
297 * while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
298 * if (want_to_stop_iteration()) {
299 * ok = ref_iterator_abort(iter);
303 * // Access information about the current reference:
304 * if (!(iter->flags & REF_ISSYMREF))
305 * printf("%s is %s\n", iter->refname, oid_to_hex(iter->oid));
307 * // If you need to peel the reference:
308 * ref_iterator_peel(iter, &oid);
311 * if (ok != ITER_DONE)
314 struct ref_iterator
{
315 struct ref_iterator_vtable
*vtable
;
318 * Does this `ref_iterator` iterate over references in order
321 unsigned int ordered
: 1;
324 const struct object_id
*oid
;
329 * Advance the iterator to the first or next item and return ITER_OK.
330 * If the iteration is exhausted, free the resources associated with
331 * the ref_iterator and return ITER_DONE. On errors, free the iterator
332 * resources and return ITER_ERROR. It is a bug to use ref_iterator or
333 * call this function again after it has returned ITER_DONE or
336 int ref_iterator_advance(struct ref_iterator
*ref_iterator
);
339 * If possible, peel the reference currently being viewed by the
340 * iterator. Return 0 on success.
342 int ref_iterator_peel(struct ref_iterator
*ref_iterator
,
343 struct object_id
*peeled
);
346 * End the iteration before it has been exhausted, freeing the
347 * reference iterator and any associated resources and returning
348 * ITER_DONE. If the abort itself failed, return ITER_ERROR.
350 int ref_iterator_abort(struct ref_iterator
*ref_iterator
);
353 * An iterator over nothing (its first ref_iterator_advance() call
354 * returns ITER_DONE).
356 struct ref_iterator
*empty_ref_iterator_begin(void);
359 * Return true iff ref_iterator is an empty_ref_iterator.
361 int is_empty_ref_iterator(struct ref_iterator
*ref_iterator
);
364 * Return an iterator that goes over each reference in `refs` for
365 * which the refname begins with prefix. If trim is non-zero, then
366 * trim that many characters off the beginning of each refname.
367 * The output is ordered by refname.
369 struct ref_iterator
*refs_ref_iterator_begin(
370 struct ref_store
*refs
,
371 const char *prefix
, int trim
,
372 enum do_for_each_ref_flags flags
);
375 * A callback function used to instruct merge_ref_iterator how to
376 * interleave the entries from iter0 and iter1. The function should
377 * return one of the constants defined in enum iterator_selection. It
378 * must not advance either of the iterators itself.
380 * The function must be prepared to handle the case that iter0 and/or
381 * iter1 is NULL, which indicates that the corresponding sub-iterator
382 * has been exhausted. Its return value must be consistent with the
383 * current states of the iterators; e.g., it must not return
384 * ITER_SKIP_1 if iter1 has already been exhausted.
386 typedef enum iterator_selection
ref_iterator_select_fn(
387 struct ref_iterator
*iter0
, struct ref_iterator
*iter1
,
391 * Iterate over the entries from iter0 and iter1, with the values
392 * interleaved as directed by the select function. The iterator takes
393 * ownership of iter0 and iter1 and frees them when the iteration is
394 * over. A derived class should set `ordered` to 1 or 0 based on
395 * whether it generates its output in order by reference name.
397 struct ref_iterator
*merge_ref_iterator_begin(
399 struct ref_iterator
*iter0
, struct ref_iterator
*iter1
,
400 ref_iterator_select_fn
*select
, void *cb_data
);
403 * An iterator consisting of the union of the entries from front and
404 * back. If there are entries common to the two sub-iterators, use the
405 * one from front. Each iterator must iterate over its entries in
406 * strcmp() order by refname for this to work.
408 * The new iterator takes ownership of its arguments and frees them
409 * when the iteration is over. As a convenience to callers, if front
410 * or back is an empty_ref_iterator, then abort that one immediately
411 * and return the other iterator directly, without wrapping it.
413 struct ref_iterator
*overlay_ref_iterator_begin(
414 struct ref_iterator
*front
, struct ref_iterator
*back
);
417 * Wrap iter0, only letting through the references whose names start
418 * with prefix. If trim is set, set iter->refname to the name of the
419 * reference with that many characters trimmed off the front;
420 * otherwise set it to the full refname. The new iterator takes over
421 * ownership of iter0 and frees it when iteration is over. It makes
422 * its own copy of prefix.
424 * As an convenience to callers, if prefix is the empty string and
425 * trim is zero, this function returns iter0 directly, without
428 * The resulting ref_iterator is ordered if iter0 is.
430 struct ref_iterator
*prefix_ref_iterator_begin(struct ref_iterator
*iter0
,
434 /* Internal implementation of reference iteration: */
437 * Base class constructor for ref_iterators. Initialize the
438 * ref_iterator part of iter, setting its vtable pointer as specified.
439 * `ordered` should be set to 1 if the iterator will iterate over
440 * references in order by refname; otherwise it should be set to 0.
441 * This is meant to be called only by the initializers of derived
444 void base_ref_iterator_init(struct ref_iterator
*iter
,
445 struct ref_iterator_vtable
*vtable
,
449 * Base class destructor for ref_iterators. Destroy the ref_iterator
450 * part of iter and shallow-free the object. This is meant to be
451 * called only by the destructors of derived classes.
453 void base_ref_iterator_free(struct ref_iterator
*iter
);
455 /* Virtual function declarations for ref_iterators: */
458 * backend-specific implementation of ref_iterator_advance. For symrefs, the
459 * function should set REF_ISSYMREF, and it should also dereference the symref
460 * to provide the OID referent. It should respect do_for_each_ref_flags
461 * that were passed to refs_ref_iterator_begin().
463 typedef int ref_iterator_advance_fn(struct ref_iterator
*ref_iterator
);
466 * Peels the current ref, returning 0 for success or -1 for failure.
468 typedef int ref_iterator_peel_fn(struct ref_iterator
*ref_iterator
,
469 struct object_id
*peeled
);
472 * Implementations of this function should free any resources specific
473 * to the derived class, then call base_ref_iterator_free() to clean
474 * up and free the ref_iterator object.
476 typedef int ref_iterator_abort_fn(struct ref_iterator
*ref_iterator
);
478 struct ref_iterator_vtable
{
479 ref_iterator_advance_fn
*advance
;
480 ref_iterator_peel_fn
*peel
;
481 ref_iterator_abort_fn
*abort
;
485 * current_ref_iter is a performance hack: when iterating over
486 * references using the for_each_ref*() functions, current_ref_iter is
487 * set to the reference iterator before calling the callback function.
488 * If the callback function calls peel_ref(), then peel_ref() first
489 * checks whether the reference to be peeled is the one referred to by
490 * the iterator (it usually is) and if so, asks the iterator for the
491 * peeled version of the reference if it is available. This avoids a
492 * refname lookup in a common case. current_ref_iter is set to NULL
493 * when the iteration is over.
495 extern struct ref_iterator
*current_ref_iter
;
498 * The common backend for the for_each_*ref* functions. Call fn for
499 * each reference in iter. If the iterator itself ever returns
500 * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop
501 * the iteration and return that value. Otherwise, return 0. In any
502 * case, free the iterator when done. This function is basically an
503 * adapter between the callback style of reference iteration and the
506 int do_for_each_repo_ref_iterator(struct repository
*r
,
507 struct ref_iterator
*iter
,
508 each_repo_ref_fn fn
, void *cb_data
);
514 /* ref_store_init flags */
515 #define REF_STORE_READ (1 << 0)
516 #define REF_STORE_WRITE (1 << 1) /* can perform update operations */
517 #define REF_STORE_ODB (1 << 2) /* has access to object database */
518 #define REF_STORE_MAIN (1 << 3)
519 #define REF_STORE_ALL_CAPS (REF_STORE_READ | \
525 * Initialize the ref_store for the specified gitdir. These functions
526 * should call base_ref_store_init() to initialize the shared part of
527 * the ref_store and to record the ref_store for later lookup.
529 typedef struct ref_store
*ref_store_init_fn(struct repository
*repo
,
533 typedef int ref_init_db_fn(struct ref_store
*refs
, struct strbuf
*err
);
535 typedef int ref_transaction_prepare_fn(struct ref_store
*refs
,
536 struct ref_transaction
*transaction
,
539 typedef int ref_transaction_finish_fn(struct ref_store
*refs
,
540 struct ref_transaction
*transaction
,
543 typedef int ref_transaction_abort_fn(struct ref_store
*refs
,
544 struct ref_transaction
*transaction
,
547 typedef int ref_transaction_commit_fn(struct ref_store
*refs
,
548 struct ref_transaction
*transaction
,
551 typedef int pack_refs_fn(struct ref_store
*ref_store
, unsigned int flags
);
552 typedef int create_symref_fn(struct ref_store
*ref_store
,
553 const char *ref_target
,
554 const char *refs_heads_master
,
556 typedef int delete_refs_fn(struct ref_store
*ref_store
, const char *msg
,
557 struct string_list
*refnames
, unsigned int flags
);
558 typedef int rename_ref_fn(struct ref_store
*ref_store
,
559 const char *oldref
, const char *newref
,
561 typedef int copy_ref_fn(struct ref_store
*ref_store
,
562 const char *oldref
, const char *newref
,
566 * Iterate over the references in `ref_store` whose names start with
567 * `prefix`. `prefix` is matched as a literal string, without regard
568 * for path separators. If prefix is NULL or the empty string, iterate
569 * over all references in `ref_store`. The output is ordered by
572 typedef struct ref_iterator
*ref_iterator_begin_fn(
573 struct ref_store
*ref_store
,
574 const char *prefix
, unsigned int flags
);
576 /* reflog functions */
579 * Iterate over the references in the specified ref_store that have a
580 * reflog. The refs are iterated over in arbitrary order.
582 typedef struct ref_iterator
*reflog_iterator_begin_fn(
583 struct ref_store
*ref_store
);
585 typedef int for_each_reflog_ent_fn(struct ref_store
*ref_store
,
587 each_reflog_ent_fn fn
,
589 typedef int for_each_reflog_ent_reverse_fn(struct ref_store
*ref_store
,
591 each_reflog_ent_fn fn
,
593 typedef int reflog_exists_fn(struct ref_store
*ref_store
, const char *refname
);
594 typedef int create_reflog_fn(struct ref_store
*ref_store
, const char *refname
,
595 int force_create
, struct strbuf
*err
);
596 typedef int delete_reflog_fn(struct ref_store
*ref_store
, const char *refname
);
597 typedef int reflog_expire_fn(struct ref_store
*ref_store
,
600 reflog_expiry_prepare_fn prepare_fn
,
601 reflog_expiry_should_prune_fn should_prune_fn
,
602 reflog_expiry_cleanup_fn cleanup_fn
,
603 void *policy_cb_data
);
606 * Read a reference from the specified reference store, non-recursively.
607 * Set type to describe the reference, and:
609 * - If refname is the name of a normal reference, fill in oid
610 * (leaving referent unchanged).
612 * - If refname is the name of a symbolic reference, write the full
613 * name of the reference to which it refers (e.g.
614 * "refs/heads/master") to referent and set the REF_ISSYMREF bit in
615 * type (leaving oid unchanged). The caller is responsible for
616 * validating that referent is a valid reference name.
618 * WARNING: refname might be used as part of a filename, so it is
619 * important from a security standpoint that it be safe in the sense
620 * of refname_is_safe(). Moreover, for symrefs this function sets
621 * referent to whatever the repository says, which might not be a
622 * properly-formatted or even safe reference name. NEITHER INPUT NOR
623 * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION.
625 * Return 0 on success, or -1 on failure. If the ref exists but is neither a
626 * symbolic ref nor an object ID, it is broken. In this case set REF_ISBROKEN in
627 * type, and return -1 (failure_errno should not be ENOENT)
629 * failure_errno provides errno codes that are interpreted beyond error
630 * reporting. The following error codes have special meaning:
631 * * ENOENT: the ref doesn't exist
632 * * EISDIR: ref name is a directory
633 * * ENOTDIR: ref prefix is not a directory
635 * Backend-specific flags might be set in type as well, regardless of
638 * It is OK for refname to point into referent. If so:
640 * - if the function succeeds with REF_ISSYMREF, referent will be
641 * overwritten and the memory formerly pointed to by it might be
642 * changed or even freed.
644 * - in all other cases, referent will be untouched, and therefore
645 * refname will still be valid and unchanged.
647 typedef int read_raw_ref_fn(struct ref_store
*ref_store
, const char *refname
,
648 struct object_id
*oid
, struct strbuf
*referent
,
649 unsigned int *type
, int *failure_errno
);
651 struct ref_storage_be
{
652 struct ref_storage_be
*next
;
654 ref_store_init_fn
*init
;
655 ref_init_db_fn
*init_db
;
657 ref_transaction_prepare_fn
*transaction_prepare
;
658 ref_transaction_finish_fn
*transaction_finish
;
659 ref_transaction_abort_fn
*transaction_abort
;
660 ref_transaction_commit_fn
*initial_transaction_commit
;
662 pack_refs_fn
*pack_refs
;
663 create_symref_fn
*create_symref
;
664 delete_refs_fn
*delete_refs
;
665 rename_ref_fn
*rename_ref
;
666 copy_ref_fn
*copy_ref
;
668 ref_iterator_begin_fn
*iterator_begin
;
669 read_raw_ref_fn
*read_raw_ref
;
671 reflog_iterator_begin_fn
*reflog_iterator_begin
;
672 for_each_reflog_ent_fn
*for_each_reflog_ent
;
673 for_each_reflog_ent_reverse_fn
*for_each_reflog_ent_reverse
;
674 reflog_exists_fn
*reflog_exists
;
675 create_reflog_fn
*create_reflog
;
676 delete_reflog_fn
*delete_reflog
;
677 reflog_expire_fn
*reflog_expire
;
680 extern struct ref_storage_be refs_be_files
;
681 extern struct ref_storage_be refs_be_packed
;
684 * A representation of the reference store for the main repository or
685 * a submodule. The ref_store instances for submodules are kept in a
686 * hash map; see get_submodule_ref_store() for more info.
689 /* The backend describing this ref_store's storage scheme: */
690 const struct ref_storage_be
*be
;
692 struct repository
*repo
;
695 * The gitdir that this ref_store applies to. Note that this is not
696 * necessarily repo->gitdir if the repo has multiple worktrees.
702 * Parse contents of a loose ref file. *failure_errno maybe be set to EINVAL for
705 int parse_loose_ref_contents(const char *buf
, struct object_id
*oid
,
706 struct strbuf
*referent
, unsigned int *type
,
710 * Fill in the generic part of refs and add it to our collection of
713 void base_ref_store_init(struct ref_store
*refs
,
714 const struct ref_storage_be
*be
);
717 * Support GIT_TRACE_REFS by optionally wrapping the given ref_store instance.
719 struct ref_store
*maybe_debug_wrap_ref_store(const char *gitdir
, struct ref_store
*store
);
721 #endif /* REFS_REFS_INTERNAL_H */