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 * assocated 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. flags
351 * can be DO_FOR_EACH_INCLUDE_BROKEN to include broken references in
352 * the iteration. The output is ordered by refname.
354 struct ref_iterator
*refs_ref_iterator_begin(
355 struct ref_store
*refs
,
356 const char *prefix
, int trim
, int flags
);
359 * A callback function used to instruct merge_ref_iterator how to
360 * interleave the entries from iter0 and iter1. The function should
361 * return one of the constants defined in enum iterator_selection. It
362 * must not advance either of the iterators itself.
364 * The function must be prepared to handle the case that iter0 and/or
365 * iter1 is NULL, which indicates that the corresponding sub-iterator
366 * has been exhausted. Its return value must be consistent with the
367 * current states of the iterators; e.g., it must not return
368 * ITER_SKIP_1 if iter1 has already been exhausted.
370 typedef enum iterator_selection
ref_iterator_select_fn(
371 struct ref_iterator
*iter0
, struct ref_iterator
*iter1
,
375 * Iterate over the entries from iter0 and iter1, with the values
376 * interleaved as directed by the select function. The iterator takes
377 * ownership of iter0 and iter1 and frees them when the iteration is
378 * over. A derived class should set `ordered` to 1 or 0 based on
379 * whether it generates its output in order by reference name.
381 struct ref_iterator
*merge_ref_iterator_begin(
383 struct ref_iterator
*iter0
, struct ref_iterator
*iter1
,
384 ref_iterator_select_fn
*select
, void *cb_data
);
387 * An iterator consisting of the union of the entries from front and
388 * back. If there are entries common to the two sub-iterators, use the
389 * one from front. Each iterator must iterate over its entries in
390 * strcmp() order by refname for this to work.
392 * The new iterator takes ownership of its arguments and frees them
393 * when the iteration is over. As a convenience to callers, if front
394 * or back is an empty_ref_iterator, then abort that one immediately
395 * and return the other iterator directly, without wrapping it.
397 struct ref_iterator
*overlay_ref_iterator_begin(
398 struct ref_iterator
*front
, struct ref_iterator
*back
);
401 * Wrap iter0, only letting through the references whose names start
402 * with prefix. If trim is set, set iter->refname to the name of the
403 * reference with that many characters trimmed off the front;
404 * otherwise set it to the full refname. The new iterator takes over
405 * ownership of iter0 and frees it when iteration is over. It makes
406 * its own copy of prefix.
408 * As an convenience to callers, if prefix is the empty string and
409 * trim is zero, this function returns iter0 directly, without
412 * The resulting ref_iterator is ordered if iter0 is.
414 struct ref_iterator
*prefix_ref_iterator_begin(struct ref_iterator
*iter0
,
418 /* Internal implementation of reference iteration: */
421 * Base class constructor for ref_iterators. Initialize the
422 * ref_iterator part of iter, setting its vtable pointer as specified.
423 * `ordered` should be set to 1 if the iterator will iterate over
424 * references in order by refname; otherwise it should be set to 0.
425 * This is meant to be called only by the initializers of derived
428 void base_ref_iterator_init(struct ref_iterator
*iter
,
429 struct ref_iterator_vtable
*vtable
,
433 * Base class destructor for ref_iterators. Destroy the ref_iterator
434 * part of iter and shallow-free the object. This is meant to be
435 * called only by the destructors of derived classes.
437 void base_ref_iterator_free(struct ref_iterator
*iter
);
439 /* Virtual function declarations for ref_iterators: */
441 typedef int ref_iterator_advance_fn(struct ref_iterator
*ref_iterator
);
443 typedef int ref_iterator_peel_fn(struct ref_iterator
*ref_iterator
,
444 struct object_id
*peeled
);
447 * Implementations of this function should free any resources specific
448 * to the derived class, then call base_ref_iterator_free() to clean
449 * up and free the ref_iterator object.
451 typedef int ref_iterator_abort_fn(struct ref_iterator
*ref_iterator
);
453 struct ref_iterator_vtable
{
454 ref_iterator_advance_fn
*advance
;
455 ref_iterator_peel_fn
*peel
;
456 ref_iterator_abort_fn
*abort
;
460 * current_ref_iter is a performance hack: when iterating over
461 * references using the for_each_ref*() functions, current_ref_iter is
462 * set to the reference iterator before calling the callback function.
463 * If the callback function calls peel_ref(), then peel_ref() first
464 * checks whether the reference to be peeled is the one referred to by
465 * the iterator (it usually is) and if so, asks the iterator for the
466 * peeled version of the reference if it is available. This avoids a
467 * refname lookup in a common case. current_ref_iter is set to NULL
468 * when the iteration is over.
470 extern struct ref_iterator
*current_ref_iter
;
473 * The common backend for the for_each_*ref* functions. Call fn for
474 * each reference in iter. If the iterator itself ever returns
475 * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop
476 * the iteration and return that value. Otherwise, return 0. In any
477 * case, free the iterator when done. This function is basically an
478 * adapter between the callback style of reference iteration and the
481 int do_for_each_repo_ref_iterator(struct repository
*r
,
482 struct ref_iterator
*iter
,
483 each_repo_ref_fn fn
, void *cb_data
);
486 * Only include per-worktree refs in a do_for_each_ref*() iteration.
487 * Normally this will be used with a files ref_store, since that's
488 * where all reference backends will presumably store their
491 #define DO_FOR_EACH_PER_WORKTREE_ONLY 0x02
497 /* ref_store_init flags */
498 #define REF_STORE_READ (1 << 0)
499 #define REF_STORE_WRITE (1 << 1) /* can perform update operations */
500 #define REF_STORE_ODB (1 << 2) /* has access to object database */
501 #define REF_STORE_MAIN (1 << 3)
502 #define REF_STORE_ALL_CAPS (REF_STORE_READ | \
508 * Initialize the ref_store for the specified gitdir. These functions
509 * should call base_ref_store_init() to initialize the shared part of
510 * the ref_store and to record the ref_store for later lookup.
512 typedef struct ref_store
*ref_store_init_fn(const char *gitdir
,
515 typedef int ref_init_db_fn(struct ref_store
*refs
, struct strbuf
*err
);
517 typedef int ref_transaction_prepare_fn(struct ref_store
*refs
,
518 struct ref_transaction
*transaction
,
521 typedef int ref_transaction_finish_fn(struct ref_store
*refs
,
522 struct ref_transaction
*transaction
,
525 typedef int ref_transaction_abort_fn(struct ref_store
*refs
,
526 struct ref_transaction
*transaction
,
529 typedef int ref_transaction_commit_fn(struct ref_store
*refs
,
530 struct ref_transaction
*transaction
,
533 typedef int pack_refs_fn(struct ref_store
*ref_store
, unsigned int flags
);
534 typedef int create_symref_fn(struct ref_store
*ref_store
,
535 const char *ref_target
,
536 const char *refs_heads_master
,
538 typedef int delete_refs_fn(struct ref_store
*ref_store
, const char *msg
,
539 struct string_list
*refnames
, unsigned int flags
);
540 typedef int rename_ref_fn(struct ref_store
*ref_store
,
541 const char *oldref
, const char *newref
,
543 typedef int copy_ref_fn(struct ref_store
*ref_store
,
544 const char *oldref
, const char *newref
,
548 * Iterate over the references in `ref_store` whose names start with
549 * `prefix`. `prefix` is matched as a literal string, without regard
550 * for path separators. If prefix is NULL or the empty string, iterate
551 * over all references in `ref_store`. The output is ordered by
554 typedef struct ref_iterator
*ref_iterator_begin_fn(
555 struct ref_store
*ref_store
,
556 const char *prefix
, unsigned int flags
);
558 /* reflog functions */
561 * Iterate over the references in the specified ref_store that have a
562 * reflog. The refs are iterated over in arbitrary order.
564 typedef struct ref_iterator
*reflog_iterator_begin_fn(
565 struct ref_store
*ref_store
);
567 typedef int for_each_reflog_ent_fn(struct ref_store
*ref_store
,
569 each_reflog_ent_fn fn
,
571 typedef int for_each_reflog_ent_reverse_fn(struct ref_store
*ref_store
,
573 each_reflog_ent_fn fn
,
575 typedef int reflog_exists_fn(struct ref_store
*ref_store
, const char *refname
);
576 typedef int create_reflog_fn(struct ref_store
*ref_store
, const char *refname
,
577 int force_create
, struct strbuf
*err
);
578 typedef int delete_reflog_fn(struct ref_store
*ref_store
, const char *refname
);
579 typedef int reflog_expire_fn(struct ref_store
*ref_store
,
580 const char *refname
, const struct object_id
*oid
,
582 reflog_expiry_prepare_fn prepare_fn
,
583 reflog_expiry_should_prune_fn should_prune_fn
,
584 reflog_expiry_cleanup_fn cleanup_fn
,
585 void *policy_cb_data
);
588 * Read a reference from the specified reference store, non-recursively.
589 * Set type to describe the reference, and:
591 * - If refname is the name of a normal reference, fill in oid
592 * (leaving referent unchanged).
594 * - If refname is the name of a symbolic reference, write the full
595 * name of the reference to which it refers (e.g.
596 * "refs/heads/master") to referent and set the REF_ISSYMREF bit in
597 * type (leaving oid unchanged). The caller is responsible for
598 * validating that referent is a valid reference name.
600 * WARNING: refname might be used as part of a filename, so it is
601 * important from a security standpoint that it be safe in the sense
602 * of refname_is_safe(). Moreover, for symrefs this function sets
603 * referent to whatever the repository says, which might not be a
604 * properly-formatted or even safe reference name. NEITHER INPUT NOR
605 * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION.
607 * Return 0 on success. If the ref doesn't exist, set errno to ENOENT
608 * and return -1. If the ref exists but is neither a symbolic ref nor
609 * an object ID, it is broken; set REF_ISBROKEN in type, set errno to
610 * EINVAL, and return -1. If there is another error reading the ref,
611 * set errno appropriately and return -1.
613 * Backend-specific flags might be set in type as well, regardless of
616 * It is OK for refname to point into referent. If so:
618 * - if the function succeeds with REF_ISSYMREF, referent will be
619 * overwritten and the memory formerly pointed to by it might be
620 * changed or even freed.
622 * - in all other cases, referent will be untouched, and therefore
623 * refname will still be valid and unchanged.
625 typedef int read_raw_ref_fn(struct ref_store
*ref_store
,
626 const char *refname
, struct object_id
*oid
,
627 struct strbuf
*referent
, unsigned int *type
);
629 struct ref_storage_be
{
630 struct ref_storage_be
*next
;
632 ref_store_init_fn
*init
;
633 ref_init_db_fn
*init_db
;
635 ref_transaction_prepare_fn
*transaction_prepare
;
636 ref_transaction_finish_fn
*transaction_finish
;
637 ref_transaction_abort_fn
*transaction_abort
;
638 ref_transaction_commit_fn
*initial_transaction_commit
;
640 pack_refs_fn
*pack_refs
;
641 create_symref_fn
*create_symref
;
642 delete_refs_fn
*delete_refs
;
643 rename_ref_fn
*rename_ref
;
644 copy_ref_fn
*copy_ref
;
646 ref_iterator_begin_fn
*iterator_begin
;
647 read_raw_ref_fn
*read_raw_ref
;
649 reflog_iterator_begin_fn
*reflog_iterator_begin
;
650 for_each_reflog_ent_fn
*for_each_reflog_ent
;
651 for_each_reflog_ent_reverse_fn
*for_each_reflog_ent_reverse
;
652 reflog_exists_fn
*reflog_exists
;
653 create_reflog_fn
*create_reflog
;
654 delete_reflog_fn
*delete_reflog
;
655 reflog_expire_fn
*reflog_expire
;
658 extern struct ref_storage_be refs_be_files
;
659 extern struct ref_storage_be refs_be_packed
;
662 * A representation of the reference store for the main repository or
663 * a submodule. The ref_store instances for submodules are kept in a
667 /* The backend describing this ref_store's storage scheme: */
668 const struct ref_storage_be
*be
;
672 * Fill in the generic part of refs and add it to our collection of
675 void base_ref_store_init(struct ref_store
*refs
,
676 const struct ref_storage_be
*be
);
678 #endif /* REFS_REFS_INTERNAL_H */