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 * Return the length of time to retry acquiring a loose reference lock
36 * before giving up, in milliseconds:
38 long get_files_ref_lock_timeout_ms(void);
41 * Return true iff refname is minimally safe. "Safe" here means that
42 * deleting a loose reference by this name will not do any damage, for
43 * example by causing a file that is not a reference to be deleted.
44 * This function does not check that the reference name is legal; for
45 * that, use check_refname_format().
47 * A refname that starts with "refs/" is considered safe iff it
48 * doesn't contain any "." or ".." components or consecutive '/'
49 * characters, end with '/', or (on Windows) contain any '\'
50 * characters. Names that do not start with "refs/" are considered
51 * safe iff they consist entirely of upper case characters and '_'
52 * (like "HEAD" and "MERGE_HEAD" but not "config" or "FOO/BAR").
54 int refname_is_safe(const char *refname
);
57 * Helper function: return true if refname, which has the specified
58 * oid and flags, can be resolved to an object in the database. If the
59 * referred-to object does not exist, emit a warning and return false.
61 int ref_resolves_to_object(const char *refname
,
62 const struct object_id
*oid
,
66 /* object was peeled successfully: */
70 * object cannot be peeled because the named object (or an
71 * object referred to by a tag in the peel chain), does not
76 /* object cannot be peeled because it is not a tag: */
79 /* ref_entry contains no peeled value because it is a symref: */
83 * ref_entry cannot be peeled because it is broken (i.e., the
84 * symbolic reference cannot even be resolved to an object
91 * Peel the named object; i.e., if the object is a tag, resolve the
92 * tag recursively until a non-tag is found. If successful, store the
93 * result to oid and return PEEL_PEELED. If the object is not a tag
94 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
95 * and leave oid unchanged.
97 enum peel_status
peel_object(const struct object_id
*name
, struct object_id
*oid
);
100 * Copy the reflog message msg to sb while cleaning up the whitespaces.
101 * Especially, convert LF to space, because reflog file is one line per entry.
103 void copy_reflog_msg(struct strbuf
*sb
, const char *msg
);
106 * Information needed for a single ref update. Set new_oid to the new
107 * value or to null_oid to delete the ref. To check the old value
108 * while the ref is locked, set (flags & REF_HAVE_OLD) and set old_oid
109 * to the old value, or to null_oid to ensure the ref does not exist
114 * If (flags & REF_HAVE_NEW), set the reference to this value
115 * (or delete it, if `new_oid` is `null_oid`).
117 struct object_id new_oid
;
120 * If (flags & REF_HAVE_OLD), check that the reference
121 * previously had this value (or didn't previously exist, if
122 * `old_oid` is `null_oid`).
124 struct object_id old_oid
;
127 * One or more of REF_NO_DEREF, REF_FORCE_CREATE_REFLOG,
128 * REF_HAVE_NEW, REF_HAVE_OLD, or backend-specific flags.
137 * If this ref_update was split off of a symref update via
138 * split_symref_update(), then this member points at that
139 * update. This is used for two purposes:
140 * 1. When reporting errors, we report the refname under which
141 * the update was originally requested.
142 * 2. When we read the old value of this reference, we
143 * propagate it back to its parent update for recording in
144 * the latter's reflog.
146 struct ref_update
*parent_update
;
148 const char refname
[FLEX_ARRAY
];
151 int refs_read_raw_ref(struct ref_store
*ref_store
,
152 const char *refname
, struct object_id
*oid
,
153 struct strbuf
*referent
, unsigned int *type
);
156 * Write an error to `err` and return a nonzero value iff the same
157 * refname appears multiple times in `refnames`. `refnames` must be
158 * sorted on entry to this function.
160 int ref_update_reject_duplicates(struct string_list
*refnames
,
164 * Add a ref_update with the specified properties to transaction, and
165 * return a pointer to the new object. This function does not verify
166 * that refname is well-formed. new_oid and old_oid are only
167 * dereferenced if the REF_HAVE_NEW and REF_HAVE_OLD bits,
168 * respectively, are set in flags.
170 struct ref_update
*ref_transaction_add_update(
171 struct ref_transaction
*transaction
,
172 const char *refname
, unsigned int flags
,
173 const struct object_id
*new_oid
,
174 const struct object_id
*old_oid
,
178 * Transaction states.
180 * OPEN: The transaction is initialized and new updates can still be
181 * added to it. An OPEN transaction can be prepared,
182 * committed, freed, or aborted (freeing and aborting an open
183 * transaction are equivalent).
185 * PREPARED: ref_transaction_prepare(), which locks all of the
186 * references involved in the update and checks that the
187 * update has no errors, has been called successfully for the
188 * transaction. A PREPARED transaction can be committed or
191 * CLOSED: The transaction is no longer active. A transaction becomes
192 * CLOSED if there is a failure while building the transaction
193 * or if a transaction is committed or aborted. A CLOSED
194 * transaction can only be freed.
196 enum ref_transaction_state
{
197 REF_TRANSACTION_OPEN
= 0,
198 REF_TRANSACTION_PREPARED
= 1,
199 REF_TRANSACTION_CLOSED
= 2
203 * Data structure for holding a reference transaction, which can
204 * consist of checks and updates to multiple references, carried out
205 * as atomically as possible. This structure is opaque to callers.
207 struct ref_transaction
{
208 struct ref_store
*ref_store
;
209 struct ref_update
**updates
;
212 enum ref_transaction_state state
;
217 * Check for entries in extras that are within the specified
218 * directory, where dirname is a reference directory name including
219 * the trailing slash (e.g., "refs/heads/foo/"). Ignore any
220 * conflicting references that are found in skip. If there is a
221 * conflicting reference, return its name.
223 * extras and skip must be sorted lists of reference names. Either one
224 * can be NULL, signifying the empty list.
226 const char *find_descendant_ref(const char *dirname
,
227 const struct string_list
*extras
,
228 const struct string_list
*skip
);
231 * Check whether an attempt to rename old_refname to new_refname would
232 * cause a D/F conflict with any existing reference (other than
233 * possibly old_refname). If there would be a conflict, emit an error
234 * message and return false; otherwise, return true.
236 * Note that this function is not safe against all races with other
237 * processes (though rename_ref() catches some races that might get by
240 int refs_rename_ref_available(struct ref_store
*refs
,
241 const char *old_refname
,
242 const char *new_refname
);
244 /* We allow "recursive" symbolic refs. Only within reason, though */
245 #define SYMREF_MAXDEPTH 5
247 /* Include broken references in a do_for_each_ref*() iteration: */
248 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
251 * Reference iterators
253 * A reference iterator encapsulates the state of an in-progress
254 * iteration over references. Create an instance of `struct
255 * ref_iterator` via one of the functions in this module.
257 * A freshly-created ref_iterator doesn't yet point at a reference. To
258 * advance the iterator, call ref_iterator_advance(). If successful,
259 * this sets the iterator's refname, oid, and flags fields to describe
260 * the next reference and returns ITER_OK. The data pointed at by
261 * refname and oid belong to the iterator; if you want to retain them
262 * after calling ref_iterator_advance() again or calling
263 * ref_iterator_abort(), you must make a copy. When the iteration has
264 * been exhausted, ref_iterator_advance() releases any resources
265 * associated with the iteration, frees the ref_iterator object, and
266 * returns ITER_DONE. If you want to abort the iteration early, call
267 * ref_iterator_abort(), which also frees the ref_iterator object and
268 * any associated resources. If there was an internal error advancing
269 * to the next entry, ref_iterator_advance() aborts the iteration,
270 * frees the ref_iterator, and returns ITER_ERROR.
272 * The reference currently being looked at can be peeled by calling
273 * ref_iterator_peel(). This function is often faster than peel_ref(),
274 * so it should be preferred when iterating over references.
276 * Putting it all together, a typical iteration looks like this:
279 * struct ref_iterator *iter = ...;
281 * while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
282 * if (want_to_stop_iteration()) {
283 * ok = ref_iterator_abort(iter);
287 * // Access information about the current reference:
288 * if (!(iter->flags & REF_ISSYMREF))
289 * printf("%s is %s\n", iter->refname, oid_to_hex(iter->oid));
291 * // If you need to peel the reference:
292 * ref_iterator_peel(iter, &oid);
295 * if (ok != ITER_DONE)
298 struct ref_iterator
{
299 struct ref_iterator_vtable
*vtable
;
302 * Does this `ref_iterator` iterate over references in order
305 unsigned int ordered
: 1;
308 const struct object_id
*oid
;
313 * Advance the iterator to the first or next item and return ITER_OK.
314 * If the iteration is exhausted, free the resources associated with
315 * the ref_iterator and return ITER_DONE. On errors, free the iterator
316 * resources and return ITER_ERROR. It is a bug to use ref_iterator or
317 * call this function again after it has returned ITER_DONE or
320 int ref_iterator_advance(struct ref_iterator
*ref_iterator
);
323 * If possible, peel the reference currently being viewed by the
324 * iterator. Return 0 on success.
326 int ref_iterator_peel(struct ref_iterator
*ref_iterator
,
327 struct object_id
*peeled
);
330 * End the iteration before it has been exhausted, freeing the
331 * reference iterator and any associated resources and returning
332 * ITER_DONE. If the abort itself failed, return ITER_ERROR.
334 int ref_iterator_abort(struct ref_iterator
*ref_iterator
);
337 * An iterator over nothing (its first ref_iterator_advance() call
338 * returns ITER_DONE).
340 struct ref_iterator
*empty_ref_iterator_begin(void);
343 * Return true iff ref_iterator is an empty_ref_iterator.
345 int is_empty_ref_iterator(struct ref_iterator
*ref_iterator
);
348 * Return an iterator that goes over each reference in `refs` for
349 * which the refname begins with prefix. If trim is non-zero, then
350 * trim that many characters off the beginning of each refname.
351 * The output is ordered by refname. The following flags are supported:
353 * DO_FOR_EACH_INCLUDE_BROKEN: include broken references in
356 * DO_FOR_EACH_PER_WORKTREE_ONLY: only produce REF_TYPE_PER_WORKTREE refs.
358 struct ref_iterator
*refs_ref_iterator_begin(
359 struct ref_store
*refs
,
360 const char *prefix
, int trim
, int flags
);
363 * A callback function used to instruct merge_ref_iterator how to
364 * interleave the entries from iter0 and iter1. The function should
365 * return one of the constants defined in enum iterator_selection. It
366 * must not advance either of the iterators itself.
368 * The function must be prepared to handle the case that iter0 and/or
369 * iter1 is NULL, which indicates that the corresponding sub-iterator
370 * has been exhausted. Its return value must be consistent with the
371 * current states of the iterators; e.g., it must not return
372 * ITER_SKIP_1 if iter1 has already been exhausted.
374 typedef enum iterator_selection
ref_iterator_select_fn(
375 struct ref_iterator
*iter0
, struct ref_iterator
*iter1
,
379 * Iterate over the entries from iter0 and iter1, with the values
380 * interleaved as directed by the select function. The iterator takes
381 * ownership of iter0 and iter1 and frees them when the iteration is
382 * over. A derived class should set `ordered` to 1 or 0 based on
383 * whether it generates its output in order by reference name.
385 struct ref_iterator
*merge_ref_iterator_begin(
387 struct ref_iterator
*iter0
, struct ref_iterator
*iter1
,
388 ref_iterator_select_fn
*select
, void *cb_data
);
391 * An iterator consisting of the union of the entries from front and
392 * back. If there are entries common to the two sub-iterators, use the
393 * one from front. Each iterator must iterate over its entries in
394 * strcmp() order by refname for this to work.
396 * The new iterator takes ownership of its arguments and frees them
397 * when the iteration is over. As a convenience to callers, if front
398 * or back is an empty_ref_iterator, then abort that one immediately
399 * and return the other iterator directly, without wrapping it.
401 struct ref_iterator
*overlay_ref_iterator_begin(
402 struct ref_iterator
*front
, struct ref_iterator
*back
);
405 * Wrap iter0, only letting through the references whose names start
406 * with prefix. If trim is set, set iter->refname to the name of the
407 * reference with that many characters trimmed off the front;
408 * otherwise set it to the full refname. The new iterator takes over
409 * ownership of iter0 and frees it when iteration is over. It makes
410 * its own copy of prefix.
412 * As an convenience to callers, if prefix is the empty string and
413 * trim is zero, this function returns iter0 directly, without
416 * The resulting ref_iterator is ordered if iter0 is.
418 struct ref_iterator
*prefix_ref_iterator_begin(struct ref_iterator
*iter0
,
422 /* Internal implementation of reference iteration: */
425 * Base class constructor for ref_iterators. Initialize the
426 * ref_iterator part of iter, setting its vtable pointer as specified.
427 * `ordered` should be set to 1 if the iterator will iterate over
428 * references in order by refname; otherwise it should be set to 0.
429 * This is meant to be called only by the initializers of derived
432 void base_ref_iterator_init(struct ref_iterator
*iter
,
433 struct ref_iterator_vtable
*vtable
,
437 * Base class destructor for ref_iterators. Destroy the ref_iterator
438 * part of iter and shallow-free the object. This is meant to be
439 * called only by the destructors of derived classes.
441 void base_ref_iterator_free(struct ref_iterator
*iter
);
443 /* Virtual function declarations for ref_iterators: */
446 * backend-specific implementation of ref_iterator_advance. For symrefs, the
447 * function should set REF_ISSYMREF, and it should also dereference the symref
448 * to provide the OID referent. If DO_FOR_EACH_INCLUDE_BROKEN is set, symrefs
449 * with non-existent referents and refs pointing to non-existent object names
450 * should also be returned. If DO_FOR_EACH_PER_WORKTREE_ONLY, only
451 * REF_TYPE_PER_WORKTREE refs should be returned.
453 typedef int ref_iterator_advance_fn(struct ref_iterator
*ref_iterator
);
455 typedef int ref_iterator_peel_fn(struct ref_iterator
*ref_iterator
,
456 struct object_id
*peeled
);
459 * Implementations of this function should free any resources specific
460 * to the derived class, then call base_ref_iterator_free() to clean
461 * up and free the ref_iterator object.
463 typedef int ref_iterator_abort_fn(struct ref_iterator
*ref_iterator
);
465 struct ref_iterator_vtable
{
466 ref_iterator_advance_fn
*advance
;
467 ref_iterator_peel_fn
*peel
;
468 ref_iterator_abort_fn
*abort
;
472 * current_ref_iter is a performance hack: when iterating over
473 * references using the for_each_ref*() functions, current_ref_iter is
474 * set to the reference iterator before calling the callback function.
475 * If the callback function calls peel_ref(), then peel_ref() first
476 * checks whether the reference to be peeled is the one referred to by
477 * the iterator (it usually is) and if so, asks the iterator for the
478 * peeled version of the reference if it is available. This avoids a
479 * refname lookup in a common case. current_ref_iter is set to NULL
480 * when the iteration is over.
482 extern struct ref_iterator
*current_ref_iter
;
485 * The common backend for the for_each_*ref* functions. Call fn for
486 * each reference in iter. If the iterator itself ever returns
487 * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop
488 * the iteration and return that value. Otherwise, return 0. In any
489 * case, free the iterator when done. This function is basically an
490 * adapter between the callback style of reference iteration and the
493 int do_for_each_repo_ref_iterator(struct repository
*r
,
494 struct ref_iterator
*iter
,
495 each_repo_ref_fn fn
, void *cb_data
);
498 * Only include per-worktree refs in a do_for_each_ref*() iteration.
499 * Normally this will be used with a files ref_store, since that's
500 * where all reference backends will presumably store their
503 #define DO_FOR_EACH_PER_WORKTREE_ONLY 0x02
509 /* ref_store_init flags */
510 #define REF_STORE_READ (1 << 0)
511 #define REF_STORE_WRITE (1 << 1) /* can perform update operations */
512 #define REF_STORE_ODB (1 << 2) /* has access to object database */
513 #define REF_STORE_MAIN (1 << 3)
514 #define REF_STORE_ALL_CAPS (REF_STORE_READ | \
520 * Initialize the ref_store for the specified gitdir. These functions
521 * should call base_ref_store_init() to initialize the shared part of
522 * the ref_store and to record the ref_store for later lookup.
524 typedef struct ref_store
*ref_store_init_fn(const char *gitdir
,
527 typedef int ref_init_db_fn(struct ref_store
*refs
, struct strbuf
*err
);
529 typedef int ref_transaction_prepare_fn(struct ref_store
*refs
,
530 struct ref_transaction
*transaction
,
533 typedef int ref_transaction_finish_fn(struct ref_store
*refs
,
534 struct ref_transaction
*transaction
,
537 typedef int ref_transaction_abort_fn(struct ref_store
*refs
,
538 struct ref_transaction
*transaction
,
541 typedef int ref_transaction_commit_fn(struct ref_store
*refs
,
542 struct ref_transaction
*transaction
,
545 typedef int pack_refs_fn(struct ref_store
*ref_store
, unsigned int flags
);
546 typedef int create_symref_fn(struct ref_store
*ref_store
,
547 const char *ref_target
,
548 const char *refs_heads_master
,
550 typedef int delete_refs_fn(struct ref_store
*ref_store
, const char *msg
,
551 struct string_list
*refnames
, unsigned int flags
);
552 typedef int rename_ref_fn(struct ref_store
*ref_store
,
553 const char *oldref
, const char *newref
,
555 typedef int copy_ref_fn(struct ref_store
*ref_store
,
556 const char *oldref
, const char *newref
,
560 * Iterate over the references in `ref_store` whose names start with
561 * `prefix`. `prefix` is matched as a literal string, without regard
562 * for path separators. If prefix is NULL or the empty string, iterate
563 * over all references in `ref_store`. The output is ordered by
566 typedef struct ref_iterator
*ref_iterator_begin_fn(
567 struct ref_store
*ref_store
,
568 const char *prefix
, unsigned int flags
);
570 /* reflog functions */
573 * Iterate over the references in the specified ref_store that have a
574 * reflog. The refs are iterated over in arbitrary order.
576 typedef struct ref_iterator
*reflog_iterator_begin_fn(
577 struct ref_store
*ref_store
);
579 typedef int for_each_reflog_ent_fn(struct ref_store
*ref_store
,
581 each_reflog_ent_fn fn
,
583 typedef int for_each_reflog_ent_reverse_fn(struct ref_store
*ref_store
,
585 each_reflog_ent_fn fn
,
587 typedef int reflog_exists_fn(struct ref_store
*ref_store
, const char *refname
);
588 typedef int create_reflog_fn(struct ref_store
*ref_store
, const char *refname
,
589 int force_create
, struct strbuf
*err
);
590 typedef int delete_reflog_fn(struct ref_store
*ref_store
, const char *refname
);
591 typedef int reflog_expire_fn(struct ref_store
*ref_store
,
592 const char *refname
, const struct object_id
*oid
,
594 reflog_expiry_prepare_fn prepare_fn
,
595 reflog_expiry_should_prune_fn should_prune_fn
,
596 reflog_expiry_cleanup_fn cleanup_fn
,
597 void *policy_cb_data
);
600 * Read a reference from the specified reference store, non-recursively.
601 * Set type to describe the reference, and:
603 * - If refname is the name of a normal reference, fill in oid
604 * (leaving referent unchanged).
606 * - If refname is the name of a symbolic reference, write the full
607 * name of the reference to which it refers (e.g.
608 * "refs/heads/master") to referent and set the REF_ISSYMREF bit in
609 * type (leaving oid unchanged). The caller is responsible for
610 * validating that referent is a valid reference name.
612 * WARNING: refname might be used as part of a filename, so it is
613 * important from a security standpoint that it be safe in the sense
614 * of refname_is_safe(). Moreover, for symrefs this function sets
615 * referent to whatever the repository says, which might not be a
616 * properly-formatted or even safe reference name. NEITHER INPUT NOR
617 * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION.
619 * Return 0 on success. If the ref doesn't exist, set errno to ENOENT
620 * and return -1. If the ref exists but is neither a symbolic ref nor
621 * an object ID, it is broken; set REF_ISBROKEN in type, set errno to
622 * EINVAL, and return -1. If there is another error reading the ref,
623 * set errno appropriately and return -1.
625 * Backend-specific flags might be set in type as well, regardless of
628 * It is OK for refname to point into referent. If so:
630 * - if the function succeeds with REF_ISSYMREF, referent will be
631 * overwritten and the memory formerly pointed to by it might be
632 * changed or even freed.
634 * - in all other cases, referent will be untouched, and therefore
635 * refname will still be valid and unchanged.
637 typedef int read_raw_ref_fn(struct ref_store
*ref_store
,
638 const char *refname
, struct object_id
*oid
,
639 struct strbuf
*referent
, unsigned int *type
);
641 struct ref_storage_be
{
642 struct ref_storage_be
*next
;
644 ref_store_init_fn
*init
;
645 ref_init_db_fn
*init_db
;
647 ref_transaction_prepare_fn
*transaction_prepare
;
648 ref_transaction_finish_fn
*transaction_finish
;
649 ref_transaction_abort_fn
*transaction_abort
;
650 ref_transaction_commit_fn
*initial_transaction_commit
;
652 pack_refs_fn
*pack_refs
;
653 create_symref_fn
*create_symref
;
654 delete_refs_fn
*delete_refs
;
655 rename_ref_fn
*rename_ref
;
656 copy_ref_fn
*copy_ref
;
658 ref_iterator_begin_fn
*iterator_begin
;
659 read_raw_ref_fn
*read_raw_ref
;
661 reflog_iterator_begin_fn
*reflog_iterator_begin
;
662 for_each_reflog_ent_fn
*for_each_reflog_ent
;
663 for_each_reflog_ent_reverse_fn
*for_each_reflog_ent_reverse
;
664 reflog_exists_fn
*reflog_exists
;
665 create_reflog_fn
*create_reflog
;
666 delete_reflog_fn
*delete_reflog
;
667 reflog_expire_fn
*reflog_expire
;
670 extern struct ref_storage_be refs_be_files
;
671 extern struct ref_storage_be refs_be_packed
;
674 * A representation of the reference store for the main repository or
675 * a submodule. The ref_store instances for submodules are kept in a
679 /* The backend describing this ref_store's storage scheme: */
680 const struct ref_storage_be
*be
;
684 * Fill in the generic part of refs and add it to our collection of
687 void base_ref_store_init(struct ref_store
*refs
,
688 const struct ref_storage_be
*be
);
690 #endif /* REFS_REFS_INTERNAL_H */