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1 #ifndef REFS_REFS_INTERNAL_H
2 #define REFS_REFS_INTERNAL_H
3
4 #include "cache.h"
5 #include "refs.h"
6 #include "iterator.h"
7
8 struct ref_transaction;
9
10 /*
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.
14 */
15
16 /*
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`.
21 */
22
23 /*
24 * The reference should be updated to new_oid.
25 */
26 #define REF_HAVE_NEW (1 << 2)
27
28 /*
29 * The current reference's value should be checked to make sure that
30 * it agrees with old_oid.
31 */
32 #define REF_HAVE_OLD (1 << 3)
33
34 /*
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.
38 */
39 #define REF_LOG_ONLY (1 << 7)
40
41 /*
42 * Return the length of time to retry acquiring a loose reference lock
43 * before giving up, in milliseconds:
44 */
45 long get_files_ref_lock_timeout_ms(void);
46
47 /*
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().
53 *
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").
60 */
61 int refname_is_safe(const char *refname);
62
63 /*
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.
67 */
68 int ref_resolves_to_object(const char *refname,
69 struct repository *repo,
70 const struct object_id *oid,
71 unsigned int flags);
72
73 enum peel_status {
74 /* object was peeled successfully: */
75 PEEL_PEELED = 0,
76
77 /*
78 * object cannot be peeled because the named object (or an
79 * object referred to by a tag in the peel chain), does not
80 * exist.
81 */
82 PEEL_INVALID = -1,
83
84 /* object cannot be peeled because it is not a tag: */
85 PEEL_NON_TAG = -2,
86
87 /* ref_entry contains no peeled value because it is a symref: */
88 PEEL_IS_SYMREF = -3,
89
90 /*
91 * ref_entry cannot be peeled because it is broken (i.e., the
92 * symbolic reference cannot even be resolved to an object
93 * name):
94 */
95 PEEL_BROKEN = -4
96 };
97
98 /*
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.
104 */
105 enum peel_status peel_object(const struct object_id *name, struct object_id *oid);
106
107 /**
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
112 * before update.
113 */
114 struct ref_update {
115 /*
116 * If (flags & REF_HAVE_NEW), set the reference to this value
117 * (or delete it, if `new_oid` is `null_oid`).
118 */
119 struct object_id new_oid;
120
121 /*
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`).
125 */
126 struct object_id old_oid;
127
128 /*
129 * One or more of REF_NO_DEREF, REF_FORCE_CREATE_REFLOG,
130 * REF_HAVE_NEW, REF_HAVE_OLD, or backend-specific flags.
131 */
132 unsigned int flags;
133
134 void *backend_data;
135 unsigned int type;
136 char *msg;
137
138 /*
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.
147 */
148 struct ref_update *parent_update;
149
150 const char refname[FLEX_ARRAY];
151 };
152
153 int refs_read_raw_ref(struct ref_store *ref_store,
154 const char *refname, struct object_id *oid,
155 struct strbuf *referent, unsigned int *type);
156
157 /*
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.
161 */
162 int ref_update_reject_duplicates(struct string_list *refnames,
163 struct strbuf *err);
164
165 /*
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.
171 */
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,
177 const char *msg);
178
179 /*
180 * Transaction states.
181 *
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).
186 *
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
191 * aborted.
192 *
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.
197 */
198 enum ref_transaction_state {
199 REF_TRANSACTION_OPEN = 0,
200 REF_TRANSACTION_PREPARED = 1,
201 REF_TRANSACTION_CLOSED = 2
202 };
203
204 /*
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.
208 */
209 struct ref_transaction {
210 struct ref_store *ref_store;
211 struct ref_update **updates;
212 size_t alloc;
213 size_t nr;
214 enum ref_transaction_state state;
215 void *backend_data;
216 };
217
218 /*
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.
224 *
225 * extras and skip must be sorted lists of reference names. Either one
226 * can be NULL, signifying the empty list.
227 */
228 const char *find_descendant_ref(const char *dirname,
229 const struct string_list *extras,
230 const struct string_list *skip);
231
232 /*
233 * Check whether an attempt to rename old_refname to new_refname would
234 * cause a D/F conflict with any existing reference (other than
235 * possibly old_refname). If there would be a conflict, emit an error
236 * message and return false; otherwise, return true.
237 *
238 * Note that this function is not safe against all races with other
239 * processes (though rename_ref() catches some races that might get by
240 * this check).
241 */
242 int refs_rename_ref_available(struct ref_store *refs,
243 const char *old_refname,
244 const char *new_refname);
245
246 /* We allow "recursive" symbolic refs. Only within reason, though */
247 #define SYMREF_MAXDEPTH 5
248
249 /*
250 * These flags are passed to refs_ref_iterator_begin() (and do_for_each_ref(),
251 * which feeds it).
252 */
253 enum do_for_each_ref_flags {
254 /*
255 * Include broken references in a do_for_each_ref*() iteration, which
256 * would normally be omitted. This includes both refs that point to
257 * missing objects (a true repository corruption), ones with illegal
258 * names (which we prefer not to expose to callers), as well as
259 * dangling symbolic refs (i.e., those that point to a non-existent
260 * ref; this is not a corruption, but as they have no valid oid, we
261 * omit them from normal iteration results).
262 */
263 DO_FOR_EACH_INCLUDE_BROKEN = (1 << 0),
264
265 /*
266 * Only include per-worktree refs in a do_for_each_ref*() iteration.
267 * Normally this will be used with a files ref_store, since that's
268 * where all reference backends will presumably store their
269 * per-worktree refs.
270 */
271 DO_FOR_EACH_PER_WORKTREE_ONLY = (1 << 1),
272
273 /*
274 * Omit dangling symrefs from output; this only has an effect with
275 * INCLUDE_BROKEN, since they are otherwise not included at all.
276 */
277 DO_FOR_EACH_OMIT_DANGLING_SYMREFS = (1 << 2),
278 };
279
280 /*
281 * Reference iterators
282 *
283 * A reference iterator encapsulates the state of an in-progress
284 * iteration over references. Create an instance of `struct
285 * ref_iterator` via one of the functions in this module.
286 *
287 * A freshly-created ref_iterator doesn't yet point at a reference. To
288 * advance the iterator, call ref_iterator_advance(). If successful,
289 * this sets the iterator's refname, oid, and flags fields to describe
290 * the next reference and returns ITER_OK. The data pointed at by
291 * refname and oid belong to the iterator; if you want to retain them
292 * after calling ref_iterator_advance() again or calling
293 * ref_iterator_abort(), you must make a copy. When the iteration has
294 * been exhausted, ref_iterator_advance() releases any resources
295 * associated with the iteration, frees the ref_iterator object, and
296 * returns ITER_DONE. If you want to abort the iteration early, call
297 * ref_iterator_abort(), which also frees the ref_iterator object and
298 * any associated resources. If there was an internal error advancing
299 * to the next entry, ref_iterator_advance() aborts the iteration,
300 * frees the ref_iterator, and returns ITER_ERROR.
301 *
302 * The reference currently being looked at can be peeled by calling
303 * ref_iterator_peel(). This function is often faster than peel_ref(),
304 * so it should be preferred when iterating over references.
305 *
306 * Putting it all together, a typical iteration looks like this:
307 *
308 * int ok;
309 * struct ref_iterator *iter = ...;
310 *
311 * while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
312 * if (want_to_stop_iteration()) {
313 * ok = ref_iterator_abort(iter);
314 * break;
315 * }
316 *
317 * // Access information about the current reference:
318 * if (!(iter->flags & REF_ISSYMREF))
319 * printf("%s is %s\n", iter->refname, oid_to_hex(iter->oid));
320 *
321 * // If you need to peel the reference:
322 * ref_iterator_peel(iter, &oid);
323 * }
324 *
325 * if (ok != ITER_DONE)
326 * handle_error();
327 */
328 struct ref_iterator {
329 struct ref_iterator_vtable *vtable;
330
331 /*
332 * Does this `ref_iterator` iterate over references in order
333 * by refname?
334 */
335 unsigned int ordered : 1;
336
337 const char *refname;
338 const struct object_id *oid;
339 unsigned int flags;
340 };
341
342 /*
343 * Advance the iterator to the first or next item and return ITER_OK.
344 * If the iteration is exhausted, free the resources associated with
345 * the ref_iterator and return ITER_DONE. On errors, free the iterator
346 * resources and return ITER_ERROR. It is a bug to use ref_iterator or
347 * call this function again after it has returned ITER_DONE or
348 * ITER_ERROR.
349 */
350 int ref_iterator_advance(struct ref_iterator *ref_iterator);
351
352 /*
353 * If possible, peel the reference currently being viewed by the
354 * iterator. Return 0 on success.
355 */
356 int ref_iterator_peel(struct ref_iterator *ref_iterator,
357 struct object_id *peeled);
358
359 /*
360 * End the iteration before it has been exhausted, freeing the
361 * reference iterator and any associated resources and returning
362 * ITER_DONE. If the abort itself failed, return ITER_ERROR.
363 */
364 int ref_iterator_abort(struct ref_iterator *ref_iterator);
365
366 /*
367 * An iterator over nothing (its first ref_iterator_advance() call
368 * returns ITER_DONE).
369 */
370 struct ref_iterator *empty_ref_iterator_begin(void);
371
372 /*
373 * Return true iff ref_iterator is an empty_ref_iterator.
374 */
375 int is_empty_ref_iterator(struct ref_iterator *ref_iterator);
376
377 /*
378 * Return an iterator that goes over each reference in `refs` for
379 * which the refname begins with prefix. If trim is non-zero, then
380 * trim that many characters off the beginning of each refname.
381 * The output is ordered by refname.
382 */
383 struct ref_iterator *refs_ref_iterator_begin(
384 struct ref_store *refs,
385 const char *prefix, int trim,
386 enum do_for_each_ref_flags flags);
387
388 /*
389 * A callback function used to instruct merge_ref_iterator how to
390 * interleave the entries from iter0 and iter1. The function should
391 * return one of the constants defined in enum iterator_selection. It
392 * must not advance either of the iterators itself.
393 *
394 * The function must be prepared to handle the case that iter0 and/or
395 * iter1 is NULL, which indicates that the corresponding sub-iterator
396 * has been exhausted. Its return value must be consistent with the
397 * current states of the iterators; e.g., it must not return
398 * ITER_SKIP_1 if iter1 has already been exhausted.
399 */
400 typedef enum iterator_selection ref_iterator_select_fn(
401 struct ref_iterator *iter0, struct ref_iterator *iter1,
402 void *cb_data);
403
404 /*
405 * Iterate over the entries from iter0 and iter1, with the values
406 * interleaved as directed by the select function. The iterator takes
407 * ownership of iter0 and iter1 and frees them when the iteration is
408 * over. A derived class should set `ordered` to 1 or 0 based on
409 * whether it generates its output in order by reference name.
410 */
411 struct ref_iterator *merge_ref_iterator_begin(
412 int ordered,
413 struct ref_iterator *iter0, struct ref_iterator *iter1,
414 ref_iterator_select_fn *select, void *cb_data);
415
416 /*
417 * An iterator consisting of the union of the entries from front and
418 * back. If there are entries common to the two sub-iterators, use the
419 * one from front. Each iterator must iterate over its entries in
420 * strcmp() order by refname for this to work.
421 *
422 * The new iterator takes ownership of its arguments and frees them
423 * when the iteration is over. As a convenience to callers, if front
424 * or back is an empty_ref_iterator, then abort that one immediately
425 * and return the other iterator directly, without wrapping it.
426 */
427 struct ref_iterator *overlay_ref_iterator_begin(
428 struct ref_iterator *front, struct ref_iterator *back);
429
430 /*
431 * Wrap iter0, only letting through the references whose names start
432 * with prefix. If trim is set, set iter->refname to the name of the
433 * reference with that many characters trimmed off the front;
434 * otherwise set it to the full refname. The new iterator takes over
435 * ownership of iter0 and frees it when iteration is over. It makes
436 * its own copy of prefix.
437 *
438 * As an convenience to callers, if prefix is the empty string and
439 * trim is zero, this function returns iter0 directly, without
440 * wrapping it.
441 *
442 * The resulting ref_iterator is ordered if iter0 is.
443 */
444 struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
445 const char *prefix,
446 int trim);
447
448 /* Internal implementation of reference iteration: */
449
450 /*
451 * Base class constructor for ref_iterators. Initialize the
452 * ref_iterator part of iter, setting its vtable pointer as specified.
453 * `ordered` should be set to 1 if the iterator will iterate over
454 * references in order by refname; otherwise it should be set to 0.
455 * This is meant to be called only by the initializers of derived
456 * classes.
457 */
458 void base_ref_iterator_init(struct ref_iterator *iter,
459 struct ref_iterator_vtable *vtable,
460 int ordered);
461
462 /*
463 * Base class destructor for ref_iterators. Destroy the ref_iterator
464 * part of iter and shallow-free the object. This is meant to be
465 * called only by the destructors of derived classes.
466 */
467 void base_ref_iterator_free(struct ref_iterator *iter);
468
469 /* Virtual function declarations for ref_iterators: */
470
471 /*
472 * backend-specific implementation of ref_iterator_advance. For symrefs, the
473 * function should set REF_ISSYMREF, and it should also dereference the symref
474 * to provide the OID referent. It should respect do_for_each_ref_flags
475 * that were passed to refs_ref_iterator_begin().
476 */
477 typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
478
479 /*
480 * Peels the current ref, returning 0 for success or -1 for failure.
481 */
482 typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
483 struct object_id *peeled);
484
485 /*
486 * Implementations of this function should free any resources specific
487 * to the derived class, then call base_ref_iterator_free() to clean
488 * up and free the ref_iterator object.
489 */
490 typedef int ref_iterator_abort_fn(struct ref_iterator *ref_iterator);
491
492 struct ref_iterator_vtable {
493 ref_iterator_advance_fn *advance;
494 ref_iterator_peel_fn *peel;
495 ref_iterator_abort_fn *abort;
496 };
497
498 /*
499 * current_ref_iter is a performance hack: when iterating over
500 * references using the for_each_ref*() functions, current_ref_iter is
501 * set to the reference iterator before calling the callback function.
502 * If the callback function calls peel_ref(), then peel_ref() first
503 * checks whether the reference to be peeled is the one referred to by
504 * the iterator (it usually is) and if so, asks the iterator for the
505 * peeled version of the reference if it is available. This avoids a
506 * refname lookup in a common case. current_ref_iter is set to NULL
507 * when the iteration is over.
508 */
509 extern struct ref_iterator *current_ref_iter;
510
511 /*
512 * The common backend for the for_each_*ref* functions. Call fn for
513 * each reference in iter. If the iterator itself ever returns
514 * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop
515 * the iteration and return that value. Otherwise, return 0. In any
516 * case, free the iterator when done. This function is basically an
517 * adapter between the callback style of reference iteration and the
518 * iterator style.
519 */
520 int do_for_each_repo_ref_iterator(struct repository *r,
521 struct ref_iterator *iter,
522 each_repo_ref_fn fn, void *cb_data);
523
524 struct ref_store;
525
526 /* refs backends */
527
528 /* ref_store_init flags */
529 #define REF_STORE_READ (1 << 0)
530 #define REF_STORE_WRITE (1 << 1) /* can perform update operations */
531 #define REF_STORE_ODB (1 << 2) /* has access to object database */
532 #define REF_STORE_MAIN (1 << 3)
533 #define REF_STORE_ALL_CAPS (REF_STORE_READ | \
534 REF_STORE_WRITE | \
535 REF_STORE_ODB | \
536 REF_STORE_MAIN)
537
538 /*
539 * Initialize the ref_store for the specified gitdir. These functions
540 * should call base_ref_store_init() to initialize the shared part of
541 * the ref_store and to record the ref_store for later lookup.
542 */
543 typedef struct ref_store *ref_store_init_fn(struct repository *repo,
544 const char *gitdir,
545 unsigned int flags);
546
547 typedef int ref_init_db_fn(struct ref_store *refs, struct strbuf *err);
548
549 typedef int ref_transaction_prepare_fn(struct ref_store *refs,
550 struct ref_transaction *transaction,
551 struct strbuf *err);
552
553 typedef int ref_transaction_finish_fn(struct ref_store *refs,
554 struct ref_transaction *transaction,
555 struct strbuf *err);
556
557 typedef int ref_transaction_abort_fn(struct ref_store *refs,
558 struct ref_transaction *transaction,
559 struct strbuf *err);
560
561 typedef int ref_transaction_commit_fn(struct ref_store *refs,
562 struct ref_transaction *transaction,
563 struct strbuf *err);
564
565 typedef int pack_refs_fn(struct ref_store *ref_store, unsigned int flags);
566 typedef int create_symref_fn(struct ref_store *ref_store,
567 const char *ref_target,
568 const char *refs_heads_master,
569 const char *logmsg);
570 typedef int delete_refs_fn(struct ref_store *ref_store, const char *msg,
571 struct string_list *refnames, unsigned int flags);
572 typedef int rename_ref_fn(struct ref_store *ref_store,
573 const char *oldref, const char *newref,
574 const char *logmsg);
575 typedef int copy_ref_fn(struct ref_store *ref_store,
576 const char *oldref, const char *newref,
577 const char *logmsg);
578
579 /*
580 * Iterate over the references in `ref_store` whose names start with
581 * `prefix`. `prefix` is matched as a literal string, without regard
582 * for path separators. If prefix is NULL or the empty string, iterate
583 * over all references in `ref_store`. The output is ordered by
584 * refname.
585 */
586 typedef struct ref_iterator *ref_iterator_begin_fn(
587 struct ref_store *ref_store,
588 const char *prefix, unsigned int flags);
589
590 /* reflog functions */
591
592 /*
593 * Iterate over the references in the specified ref_store that have a
594 * reflog. The refs are iterated over in arbitrary order.
595 */
596 typedef struct ref_iterator *reflog_iterator_begin_fn(
597 struct ref_store *ref_store);
598
599 typedef int for_each_reflog_ent_fn(struct ref_store *ref_store,
600 const char *refname,
601 each_reflog_ent_fn fn,
602 void *cb_data);
603 typedef int for_each_reflog_ent_reverse_fn(struct ref_store *ref_store,
604 const char *refname,
605 each_reflog_ent_fn fn,
606 void *cb_data);
607 typedef int reflog_exists_fn(struct ref_store *ref_store, const char *refname);
608 typedef int create_reflog_fn(struct ref_store *ref_store, const char *refname,
609 int force_create, struct strbuf *err);
610 typedef int delete_reflog_fn(struct ref_store *ref_store, const char *refname);
611 typedef int reflog_expire_fn(struct ref_store *ref_store,
612 const char *refname,
613 unsigned int flags,
614 reflog_expiry_prepare_fn prepare_fn,
615 reflog_expiry_should_prune_fn should_prune_fn,
616 reflog_expiry_cleanup_fn cleanup_fn,
617 void *policy_cb_data);
618
619 /*
620 * Read a reference from the specified reference store, non-recursively.
621 * Set type to describe the reference, and:
622 *
623 * - If refname is the name of a normal reference, fill in oid
624 * (leaving referent unchanged).
625 *
626 * - If refname is the name of a symbolic reference, write the full
627 * name of the reference to which it refers (e.g.
628 * "refs/heads/master") to referent and set the REF_ISSYMREF bit in
629 * type (leaving oid unchanged). The caller is responsible for
630 * validating that referent is a valid reference name.
631 *
632 * WARNING: refname might be used as part of a filename, so it is
633 * important from a security standpoint that it be safe in the sense
634 * of refname_is_safe(). Moreover, for symrefs this function sets
635 * referent to whatever the repository says, which might not be a
636 * properly-formatted or even safe reference name. NEITHER INPUT NOR
637 * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION.
638 *
639 * Return 0 on success, or -1 on failure. If the ref exists but is neither a
640 * symbolic ref nor an object ID, it is broken. In this case set REF_ISBROKEN in
641 * type, and return -1 (failure_errno should not be ENOENT)
642 *
643 * failure_errno provides errno codes that are interpreted beyond error
644 * reporting. The following error codes have special meaning:
645 * * ENOENT: the ref doesn't exist
646 * * EISDIR: ref name is a directory
647 * * ENOTDIR: ref prefix is not a directory
648 *
649 * Backend-specific flags might be set in type as well, regardless of
650 * outcome.
651 *
652 * It is OK for refname to point into referent. If so:
653 *
654 * - if the function succeeds with REF_ISSYMREF, referent will be
655 * overwritten and the memory formerly pointed to by it might be
656 * changed or even freed.
657 *
658 * - in all other cases, referent will be untouched, and therefore
659 * refname will still be valid and unchanged.
660 */
661 typedef int read_raw_ref_fn(struct ref_store *ref_store, const char *refname,
662 struct object_id *oid, struct strbuf *referent,
663 unsigned int *type, int *failure_errno);
664
665 struct ref_storage_be {
666 struct ref_storage_be *next;
667 const char *name;
668 ref_store_init_fn *init;
669 ref_init_db_fn *init_db;
670
671 ref_transaction_prepare_fn *transaction_prepare;
672 ref_transaction_finish_fn *transaction_finish;
673 ref_transaction_abort_fn *transaction_abort;
674 ref_transaction_commit_fn *initial_transaction_commit;
675
676 pack_refs_fn *pack_refs;
677 create_symref_fn *create_symref;
678 delete_refs_fn *delete_refs;
679 rename_ref_fn *rename_ref;
680 copy_ref_fn *copy_ref;
681
682 ref_iterator_begin_fn *iterator_begin;
683 read_raw_ref_fn *read_raw_ref;
684
685 reflog_iterator_begin_fn *reflog_iterator_begin;
686 for_each_reflog_ent_fn *for_each_reflog_ent;
687 for_each_reflog_ent_reverse_fn *for_each_reflog_ent_reverse;
688 reflog_exists_fn *reflog_exists;
689 create_reflog_fn *create_reflog;
690 delete_reflog_fn *delete_reflog;
691 reflog_expire_fn *reflog_expire;
692 };
693
694 extern struct ref_storage_be refs_be_files;
695 extern struct ref_storage_be refs_be_packed;
696
697 /*
698 * A representation of the reference store for the main repository or
699 * a submodule. The ref_store instances for submodules are kept in a
700 * hash map; see get_submodule_ref_store() for more info.
701 */
702 struct ref_store {
703 /* The backend describing this ref_store's storage scheme: */
704 const struct ref_storage_be *be;
705
706 struct repository *repo;
707
708 /*
709 * The gitdir that this ref_store applies to. Note that this is not
710 * necessarily repo->gitdir if the repo has multiple worktrees.
711 */
712 char *gitdir;
713 };
714
715 /*
716 * Parse contents of a loose ref file.
717 */
718 int parse_loose_ref_contents(const char *buf, struct object_id *oid,
719 struct strbuf *referent, unsigned int *type);
720
721 /*
722 * Fill in the generic part of refs and add it to our collection of
723 * reference stores.
724 */
725 void base_ref_store_init(struct ref_store *refs,
726 const struct ref_storage_be *be);
727
728 /*
729 * Support GIT_TRACE_REFS by optionally wrapping the given ref_store instance.
730 */
731 struct ref_store *maybe_debug_wrap_ref_store(const char *gitdir, struct ref_store *store);
732
733 #endif /* REFS_REFS_INTERNAL_H */