Merge branch 'rj/header-check'
[git/git.git] / refs / refs-internal.h
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 * Return the length of time to retry acquiring a loose reference lock
36 * before giving up, in milliseconds:
37 */
38 long get_files_ref_lock_timeout_ms(void);
39
40 /*
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().
46 *
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").
53 */
54 int refname_is_safe(const char *refname);
55
56 /*
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.
60 */
61 int ref_resolves_to_object(const char *refname,
62 const struct object_id *oid,
63 unsigned int flags);
64
65 enum peel_status {
66 /* object was peeled successfully: */
67 PEEL_PEELED = 0,
68
69 /*
70 * object cannot be peeled because the named object (or an
71 * object referred to by a tag in the peel chain), does not
72 * exist.
73 */
74 PEEL_INVALID = -1,
75
76 /* object cannot be peeled because it is not a tag: */
77 PEEL_NON_TAG = -2,
78
79 /* ref_entry contains no peeled value because it is a symref: */
80 PEEL_IS_SYMREF = -3,
81
82 /*
83 * ref_entry cannot be peeled because it is broken (i.e., the
84 * symbolic reference cannot even be resolved to an object
85 * name):
86 */
87 PEEL_BROKEN = -4
88 };
89
90 /*
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.
96 */
97 enum peel_status peel_object(const struct object_id *name, struct object_id *oid);
98
99 /*
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.
102 */
103 void copy_reflog_msg(struct strbuf *sb, const char *msg);
104
105 /**
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
110 * before update.
111 */
112 struct ref_update {
113 /*
114 * If (flags & REF_HAVE_NEW), set the reference to this value
115 * (or delete it, if `new_oid` is `null_oid`).
116 */
117 struct object_id new_oid;
118
119 /*
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`).
123 */
124 struct object_id old_oid;
125
126 /*
127 * One or more of REF_NO_DEREF, REF_FORCE_CREATE_REFLOG,
128 * REF_HAVE_NEW, REF_HAVE_OLD, or backend-specific flags.
129 */
130 unsigned int flags;
131
132 void *backend_data;
133 unsigned int type;
134 char *msg;
135
136 /*
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.
145 */
146 struct ref_update *parent_update;
147
148 const char refname[FLEX_ARRAY];
149 };
150
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);
154
155 /*
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.
159 */
160 int ref_update_reject_duplicates(struct string_list *refnames,
161 struct strbuf *err);
162
163 /*
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.
169 */
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,
175 const char *msg);
176
177 /*
178 * Transaction states.
179 *
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).
184 *
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
189 * aborted.
190 *
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.
195 */
196 enum ref_transaction_state {
197 REF_TRANSACTION_OPEN = 0,
198 REF_TRANSACTION_PREPARED = 1,
199 REF_TRANSACTION_CLOSED = 2
200 };
201
202 /*
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.
206 */
207 struct ref_transaction {
208 struct ref_store *ref_store;
209 struct ref_update **updates;
210 size_t alloc;
211 size_t nr;
212 enum ref_transaction_state state;
213 void *backend_data;
214 };
215
216 /*
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.
222 *
223 * extras and skip must be sorted lists of reference names. Either one
224 * can be NULL, signifying the empty list.
225 */
226 const char *find_descendant_ref(const char *dirname,
227 const struct string_list *extras,
228 const struct string_list *skip);
229
230 /*
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.
235 *
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
238 * this check).
239 */
240 int refs_rename_ref_available(struct ref_store *refs,
241 const char *old_refname,
242 const char *new_refname);
243
244 /* We allow "recursive" symbolic refs. Only within reason, though */
245 #define SYMREF_MAXDEPTH 5
246
247 /* Include broken references in a do_for_each_ref*() iteration: */
248 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
249
250 /*
251 * Reference iterators
252 *
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.
256 *
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.
271 *
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.
275 *
276 * Putting it all together, a typical iteration looks like this:
277 *
278 * int ok;
279 * struct ref_iterator *iter = ...;
280 *
281 * while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
282 * if (want_to_stop_iteration()) {
283 * ok = ref_iterator_abort(iter);
284 * break;
285 * }
286 *
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));
290 *
291 * // If you need to peel the reference:
292 * ref_iterator_peel(iter, &oid);
293 * }
294 *
295 * if (ok != ITER_DONE)
296 * handle_error();
297 */
298 struct ref_iterator {
299 struct ref_iterator_vtable *vtable;
300
301 /*
302 * Does this `ref_iterator` iterate over references in order
303 * by refname?
304 */
305 unsigned int ordered : 1;
306
307 const char *refname;
308 const struct object_id *oid;
309 unsigned int flags;
310 };
311
312 /*
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
318 * ITER_ERROR.
319 */
320 int ref_iterator_advance(struct ref_iterator *ref_iterator);
321
322 /*
323 * If possible, peel the reference currently being viewed by the
324 * iterator. Return 0 on success.
325 */
326 int ref_iterator_peel(struct ref_iterator *ref_iterator,
327 struct object_id *peeled);
328
329 /*
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.
333 */
334 int ref_iterator_abort(struct ref_iterator *ref_iterator);
335
336 /*
337 * An iterator over nothing (its first ref_iterator_advance() call
338 * returns ITER_DONE).
339 */
340 struct ref_iterator *empty_ref_iterator_begin(void);
341
342 /*
343 * Return true iff ref_iterator is an empty_ref_iterator.
344 */
345 int is_empty_ref_iterator(struct ref_iterator *ref_iterator);
346
347 /*
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.
353 */
354 struct ref_iterator *refs_ref_iterator_begin(
355 struct ref_store *refs,
356 const char *prefix, int trim, int flags);
357
358 /*
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.
363 *
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.
369 */
370 typedef enum iterator_selection ref_iterator_select_fn(
371 struct ref_iterator *iter0, struct ref_iterator *iter1,
372 void *cb_data);
373
374 /*
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.
380 */
381 struct ref_iterator *merge_ref_iterator_begin(
382 int ordered,
383 struct ref_iterator *iter0, struct ref_iterator *iter1,
384 ref_iterator_select_fn *select, void *cb_data);
385
386 /*
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.
391 *
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.
396 */
397 struct ref_iterator *overlay_ref_iterator_begin(
398 struct ref_iterator *front, struct ref_iterator *back);
399
400 /*
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.
407 *
408 * As an convenience to callers, if prefix is the empty string and
409 * trim is zero, this function returns iter0 directly, without
410 * wrapping it.
411 *
412 * The resulting ref_iterator is ordered if iter0 is.
413 */
414 struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
415 const char *prefix,
416 int trim);
417
418 /* Internal implementation of reference iteration: */
419
420 /*
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
426 * classes.
427 */
428 void base_ref_iterator_init(struct ref_iterator *iter,
429 struct ref_iterator_vtable *vtable,
430 int ordered);
431
432 /*
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.
436 */
437 void base_ref_iterator_free(struct ref_iterator *iter);
438
439 /* Virtual function declarations for ref_iterators: */
440
441 typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
442
443 typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
444 struct object_id *peeled);
445
446 /*
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.
450 */
451 typedef int ref_iterator_abort_fn(struct ref_iterator *ref_iterator);
452
453 struct ref_iterator_vtable {
454 ref_iterator_advance_fn *advance;
455 ref_iterator_peel_fn *peel;
456 ref_iterator_abort_fn *abort;
457 };
458
459 /*
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.
469 */
470 extern struct ref_iterator *current_ref_iter;
471
472 /*
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
479 * iterator style.
480 */
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);
484
485 /*
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
489 * per-worktree refs.
490 */
491 #define DO_FOR_EACH_PER_WORKTREE_ONLY 0x02
492
493 struct ref_store;
494
495 /* refs backends */
496
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 | \
503 REF_STORE_WRITE | \
504 REF_STORE_ODB | \
505 REF_STORE_MAIN)
506
507 /*
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.
511 */
512 typedef struct ref_store *ref_store_init_fn(const char *gitdir,
513 unsigned int flags);
514
515 typedef int ref_init_db_fn(struct ref_store *refs, struct strbuf *err);
516
517 typedef int ref_transaction_prepare_fn(struct ref_store *refs,
518 struct ref_transaction *transaction,
519 struct strbuf *err);
520
521 typedef int ref_transaction_finish_fn(struct ref_store *refs,
522 struct ref_transaction *transaction,
523 struct strbuf *err);
524
525 typedef int ref_transaction_abort_fn(struct ref_store *refs,
526 struct ref_transaction *transaction,
527 struct strbuf *err);
528
529 typedef int ref_transaction_commit_fn(struct ref_store *refs,
530 struct ref_transaction *transaction,
531 struct strbuf *err);
532
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,
537 const char *logmsg);
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,
542 const char *logmsg);
543 typedef int copy_ref_fn(struct ref_store *ref_store,
544 const char *oldref, const char *newref,
545 const char *logmsg);
546
547 /*
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
552 * refname.
553 */
554 typedef struct ref_iterator *ref_iterator_begin_fn(
555 struct ref_store *ref_store,
556 const char *prefix, unsigned int flags);
557
558 /* reflog functions */
559
560 /*
561 * Iterate over the references in the specified ref_store that have a
562 * reflog. The refs are iterated over in arbitrary order.
563 */
564 typedef struct ref_iterator *reflog_iterator_begin_fn(
565 struct ref_store *ref_store);
566
567 typedef int for_each_reflog_ent_fn(struct ref_store *ref_store,
568 const char *refname,
569 each_reflog_ent_fn fn,
570 void *cb_data);
571 typedef int for_each_reflog_ent_reverse_fn(struct ref_store *ref_store,
572 const char *refname,
573 each_reflog_ent_fn fn,
574 void *cb_data);
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,
581 unsigned int flags,
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);
586
587 /*
588 * Read a reference from the specified reference store, non-recursively.
589 * Set type to describe the reference, and:
590 *
591 * - If refname is the name of a normal reference, fill in oid
592 * (leaving referent unchanged).
593 *
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.
599 *
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.
606 *
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.
612 *
613 * Backend-specific flags might be set in type as well, regardless of
614 * outcome.
615 *
616 * It is OK for refname to point into referent. If so:
617 *
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.
621 *
622 * - in all other cases, referent will be untouched, and therefore
623 * refname will still be valid and unchanged.
624 */
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);
628
629 struct ref_storage_be {
630 struct ref_storage_be *next;
631 const char *name;
632 ref_store_init_fn *init;
633 ref_init_db_fn *init_db;
634
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;
639
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;
645
646 ref_iterator_begin_fn *iterator_begin;
647 read_raw_ref_fn *read_raw_ref;
648
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;
656 };
657
658 extern struct ref_storage_be refs_be_files;
659 extern struct ref_storage_be refs_be_packed;
660
661 /*
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
664 * linked list.
665 */
666 struct ref_store {
667 /* The backend describing this ref_store's storage scheme: */
668 const struct ref_storage_be *be;
669 };
670
671 /*
672 * Fill in the generic part of refs and add it to our collection of
673 * reference stores.
674 */
675 void base_ref_store_init(struct ref_store *refs,
676 const struct ref_storage_be *be);
677
678 #endif /* REFS_REFS_INTERNAL_H */