1 #ifndef REFS_REFS_INTERNAL_H
2 #define REFS_REFS_INTERNAL_H
5 * Data structures and functions for the internal use of the refs
6 * module. Code outside of the refs module should use only the public
7 * functions defined in "refs.h", and should *not* include this file.
11 * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken
12 * refs (i.e., because the reference is about to be deleted anyway).
14 #define REF_DELETING 0x02
17 * Used as a flag in ref_update::flags when a loose ref is being
18 * pruned. This flag must only be used when REF_NODEREF is set.
20 #define REF_ISPRUNING 0x04
23 * Used as a flag in ref_update::flags when the reference should be
24 * updated to new_sha1.
26 #define REF_HAVE_NEW 0x08
29 * Used as a flag in ref_update::flags when old_sha1 should be
32 #define REF_HAVE_OLD 0x10
35 * Used as a flag in ref_update::flags when the lockfile needs to be
38 #define REF_NEEDS_COMMIT 0x20
41 * 0x40 is REF_FORCE_CREATE_REFLOG, so skip it if you're adding a
42 * value to ref_update::flags
46 * Used as a flag in ref_update::flags when we want to log a ref
47 * update but not actually perform it. This is used when a symbolic
48 * ref update is split up.
50 #define REF_LOG_ONLY 0x80
53 * Internal flag, meaning that the containing ref_update was via an
56 #define REF_UPDATE_VIA_HEAD 0x100
59 * Used as a flag in ref_update::flags when the loose reference has
62 #define REF_DELETED_LOOSE 0x200
65 * Return the length of time to retry acquiring a loose reference lock
66 * before giving up, in milliseconds:
68 long get_files_ref_lock_timeout_ms(void);
71 * Return true iff refname is minimally safe. "Safe" here means that
72 * deleting a loose reference by this name will not do any damage, for
73 * example by causing a file that is not a reference to be deleted.
74 * This function does not check that the reference name is legal; for
75 * that, use check_refname_format().
77 * A refname that starts with "refs/" is considered safe iff it
78 * doesn't contain any "." or ".." components or consecutive '/'
79 * characters, end with '/', or (on Windows) contain any '\'
80 * characters. Names that do not start with "refs/" are considered
81 * safe iff they consist entirely of upper case characters and '_'
82 * (like "HEAD" and "MERGE_HEAD" but not "config" or "FOO/BAR").
84 int refname_is_safe(const char *refname
);
87 * Helper function: return true if refname, which has the specified
88 * oid and flags, can be resolved to an object in the database. If the
89 * referred-to object does not exist, emit a warning and return false.
91 int ref_resolves_to_object(const char *refname
,
92 const struct object_id
*oid
,
96 /* object was peeled successfully: */
100 * object cannot be peeled because the named object (or an
101 * object referred to by a tag in the peel chain), does not
106 /* object cannot be peeled because it is not a tag: */
109 /* ref_entry contains no peeled value because it is a symref: */
113 * ref_entry cannot be peeled because it is broken (i.e., the
114 * symbolic reference cannot even be resolved to an object
121 * Peel the named object; i.e., if the object is a tag, resolve the
122 * tag recursively until a non-tag is found. If successful, store the
123 * result to sha1 and return PEEL_PEELED. If the object is not a tag
124 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
125 * and leave sha1 unchanged.
127 enum peel_status
peel_object(const unsigned char *name
, unsigned char *sha1
);
130 * Copy the reflog message msg to buf, which has been allocated sufficiently
131 * large, while cleaning up the whitespaces. Especially, convert LF to space,
132 * because reflog file is one line per entry.
134 int copy_reflog_msg(char *buf
, const char *msg
);
137 * Information needed for a single ref update. Set new_sha1 to the new
138 * value or to null_sha1 to delete the ref. To check the old value
139 * while the ref is locked, set (flags & REF_HAVE_OLD) and set
140 * old_sha1 to the old value, or to null_sha1 to ensure the ref does
141 * not exist before update.
146 * If (flags & REF_HAVE_NEW), set the reference to this value:
148 struct object_id new_oid
;
151 * If (flags & REF_HAVE_OLD), check that the reference
152 * previously had this value:
154 struct object_id old_oid
;
157 * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF,
158 * REF_DELETING, REF_ISPRUNING, REF_LOG_ONLY,
159 * REF_UPDATE_VIA_HEAD, REF_NEEDS_COMMIT, and
169 * If this ref_update was split off of a symref update via
170 * split_symref_update(), then this member points at that
171 * update. This is used for two purposes:
172 * 1. When reporting errors, we report the refname under which
173 * the update was originally requested.
174 * 2. When we read the old value of this reference, we
175 * propagate it back to its parent update for recording in
176 * the latter's reflog.
178 struct ref_update
*parent_update
;
180 const char refname
[FLEX_ARRAY
];
183 int refs_read_raw_ref(struct ref_store
*ref_store
,
184 const char *refname
, unsigned char *sha1
,
185 struct strbuf
*referent
, unsigned int *type
);
188 * Write an error to `err` and return a nonzero value iff the same
189 * refname appears multiple times in `refnames`. `refnames` must be
190 * sorted on entry to this function.
192 int ref_update_reject_duplicates(struct string_list
*refnames
,
196 * Add a ref_update with the specified properties to transaction, and
197 * return a pointer to the new object. This function does not verify
198 * that refname is well-formed. new_sha1 and old_sha1 are only
199 * dereferenced if the REF_HAVE_NEW and REF_HAVE_OLD bits,
200 * respectively, are set in flags.
202 struct ref_update
*ref_transaction_add_update(
203 struct ref_transaction
*transaction
,
204 const char *refname
, unsigned int flags
,
205 const unsigned char *new_sha1
,
206 const unsigned char *old_sha1
,
210 * Transaction states.
212 * OPEN: The transaction is initialized and new updates can still be
213 * added to it. An OPEN transaction can be prepared,
214 * committed, freed, or aborted (freeing and aborting an open
215 * transaction are equivalent).
217 * PREPARED: ref_transaction_prepare(), which locks all of the
218 * references involved in the update and checks that the
219 * update has no errors, has been called successfully for the
220 * transaction. A PREPARED transaction can be committed or
223 * CLOSED: The transaction is no longer active. A transaction becomes
224 * CLOSED if there is a failure while building the transaction
225 * or if a transaction is committed or aborted. A CLOSED
226 * transaction can only be freed.
228 enum ref_transaction_state
{
229 REF_TRANSACTION_OPEN
= 0,
230 REF_TRANSACTION_PREPARED
= 1,
231 REF_TRANSACTION_CLOSED
= 2
235 * Data structure for holding a reference transaction, which can
236 * consist of checks and updates to multiple references, carried out
237 * as atomically as possible. This structure is opaque to callers.
239 struct ref_transaction
{
240 struct ref_store
*ref_store
;
241 struct ref_update
**updates
;
244 enum ref_transaction_state state
;
249 * Check for entries in extras that are within the specified
250 * directory, where dirname is a reference directory name including
251 * the trailing slash (e.g., "refs/heads/foo/"). Ignore any
252 * conflicting references that are found in skip. If there is a
253 * conflicting reference, return its name.
255 * extras and skip must be sorted lists of reference names. Either one
256 * can be NULL, signifying the empty list.
258 const char *find_descendant_ref(const char *dirname
,
259 const struct string_list
*extras
,
260 const struct string_list
*skip
);
263 * Check whether an attempt to rename old_refname to new_refname would
264 * cause a D/F conflict with any existing reference (other than
265 * possibly old_refname). If there would be a conflict, emit an error
266 * message and return false; otherwise, return true.
268 * Note that this function is not safe against all races with other
269 * processes (though rename_ref() catches some races that might get by
272 int refs_rename_ref_available(struct ref_store
*refs
,
273 const char *old_refname
,
274 const char *new_refname
);
276 /* We allow "recursive" symbolic refs. Only within reason, though */
277 #define SYMREF_MAXDEPTH 5
279 /* Include broken references in a do_for_each_ref*() iteration: */
280 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
283 * Reference iterators
285 * A reference iterator encapsulates the state of an in-progress
286 * iteration over references. Create an instance of `struct
287 * ref_iterator` via one of the functions in this module.
289 * A freshly-created ref_iterator doesn't yet point at a reference. To
290 * advance the iterator, call ref_iterator_advance(). If successful,
291 * this sets the iterator's refname, oid, and flags fields to describe
292 * the next reference and returns ITER_OK. The data pointed at by
293 * refname and oid belong to the iterator; if you want to retain them
294 * after calling ref_iterator_advance() again or calling
295 * ref_iterator_abort(), you must make a copy. When the iteration has
296 * been exhausted, ref_iterator_advance() releases any resources
297 * assocated with the iteration, frees the ref_iterator object, and
298 * returns ITER_DONE. If you want to abort the iteration early, call
299 * ref_iterator_abort(), which also frees the ref_iterator object and
300 * any associated resources. If there was an internal error advancing
301 * to the next entry, ref_iterator_advance() aborts the iteration,
302 * frees the ref_iterator, and returns ITER_ERROR.
304 * The reference currently being looked at can be peeled by calling
305 * ref_iterator_peel(). This function is often faster than peel_ref(),
306 * so it should be preferred when iterating over references.
308 * Putting it all together, a typical iteration looks like this:
311 * struct ref_iterator *iter = ...;
313 * while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
314 * if (want_to_stop_iteration()) {
315 * ok = ref_iterator_abort(iter);
319 * // Access information about the current reference:
320 * if (!(iter->flags & REF_ISSYMREF))
321 * printf("%s is %s\n", iter->refname, oid_to_hex(&iter->oid));
323 * // If you need to peel the reference:
324 * ref_iterator_peel(iter, &oid);
327 * if (ok != ITER_DONE)
330 struct ref_iterator
{
331 struct ref_iterator_vtable
*vtable
;
333 const struct object_id
*oid
;
338 * Advance the iterator to the first or next item and return ITER_OK.
339 * If the iteration is exhausted, free the resources associated with
340 * the ref_iterator and return ITER_DONE. On errors, free the iterator
341 * resources and return ITER_ERROR. It is a bug to use ref_iterator or
342 * call this function again after it has returned ITER_DONE or
345 int ref_iterator_advance(struct ref_iterator
*ref_iterator
);
348 * If possible, peel the reference currently being viewed by the
349 * iterator. Return 0 on success.
351 int ref_iterator_peel(struct ref_iterator
*ref_iterator
,
352 struct object_id
*peeled
);
355 * End the iteration before it has been exhausted, freeing the
356 * reference iterator and any associated resources and returning
357 * ITER_DONE. If the abort itself failed, return ITER_ERROR.
359 int ref_iterator_abort(struct ref_iterator
*ref_iterator
);
362 * An iterator over nothing (its first ref_iterator_advance() call
363 * returns ITER_DONE).
365 struct ref_iterator
*empty_ref_iterator_begin(void);
368 * Return true iff ref_iterator is an empty_ref_iterator.
370 int is_empty_ref_iterator(struct ref_iterator
*ref_iterator
);
373 * Return an iterator that goes over each reference in `refs` for
374 * which the refname begins with prefix. If trim is non-zero, then
375 * trim that many characters off the beginning of each refname. flags
376 * can be DO_FOR_EACH_INCLUDE_BROKEN to include broken references in
379 struct ref_iterator
*refs_ref_iterator_begin(
380 struct ref_store
*refs
,
381 const char *prefix
, int trim
, int flags
);
384 * A callback function used to instruct merge_ref_iterator how to
385 * interleave the entries from iter0 and iter1. The function should
386 * return one of the constants defined in enum iterator_selection. It
387 * must not advance either of the iterators itself.
389 * The function must be prepared to handle the case that iter0 and/or
390 * iter1 is NULL, which indicates that the corresponding sub-iterator
391 * has been exhausted. Its return value must be consistent with the
392 * current states of the iterators; e.g., it must not return
393 * ITER_SKIP_1 if iter1 has already been exhausted.
395 typedef enum iterator_selection
ref_iterator_select_fn(
396 struct ref_iterator
*iter0
, struct ref_iterator
*iter1
,
400 * Iterate over the entries from iter0 and iter1, with the values
401 * interleaved as directed by the select function. The iterator takes
402 * ownership of iter0 and iter1 and frees them when the iteration is
405 struct ref_iterator
*merge_ref_iterator_begin(
406 struct ref_iterator
*iter0
, struct ref_iterator
*iter1
,
407 ref_iterator_select_fn
*select
, void *cb_data
);
410 * An iterator consisting of the union of the entries from front and
411 * back. If there are entries common to the two sub-iterators, use the
412 * one from front. Each iterator must iterate over its entries in
413 * strcmp() order by refname for this to work.
415 * The new iterator takes ownership of its arguments and frees them
416 * when the iteration is over. As a convenience to callers, if front
417 * or back is an empty_ref_iterator, then abort that one immediately
418 * and return the other iterator directly, without wrapping it.
420 struct ref_iterator
*overlay_ref_iterator_begin(
421 struct ref_iterator
*front
, struct ref_iterator
*back
);
424 * Wrap iter0, only letting through the references whose names start
425 * with prefix. If trim is set, set iter->refname to the name of the
426 * reference with that many characters trimmed off the front;
427 * otherwise set it to the full refname. The new iterator takes over
428 * ownership of iter0 and frees it when iteration is over. It makes
429 * its own copy of prefix.
431 * As an convenience to callers, if prefix is the empty string and
432 * trim is zero, this function returns iter0 directly, without
435 struct ref_iterator
*prefix_ref_iterator_begin(struct ref_iterator
*iter0
,
439 /* Internal implementation of reference iteration: */
442 * Base class constructor for ref_iterators. Initialize the
443 * ref_iterator part of iter, setting its vtable pointer as specified.
444 * This is meant to be called only by the initializers of derived
447 void base_ref_iterator_init(struct ref_iterator
*iter
,
448 struct ref_iterator_vtable
*vtable
);
451 * Base class destructor for ref_iterators. Destroy the ref_iterator
452 * part of iter and shallow-free the object. This is meant to be
453 * called only by the destructors of derived classes.
455 void base_ref_iterator_free(struct ref_iterator
*iter
);
457 /* Virtual function declarations for ref_iterators: */
459 typedef int ref_iterator_advance_fn(struct ref_iterator
*ref_iterator
);
461 typedef int ref_iterator_peel_fn(struct ref_iterator
*ref_iterator
,
462 struct object_id
*peeled
);
465 * Implementations of this function should free any resources specific
466 * to the derived class, then call base_ref_iterator_free() to clean
467 * up and free the ref_iterator object.
469 typedef int ref_iterator_abort_fn(struct ref_iterator
*ref_iterator
);
471 struct ref_iterator_vtable
{
472 ref_iterator_advance_fn
*advance
;
473 ref_iterator_peel_fn
*peel
;
474 ref_iterator_abort_fn
*abort
;
478 * current_ref_iter is a performance hack: when iterating over
479 * references using the for_each_ref*() functions, current_ref_iter is
480 * set to the reference iterator before calling the callback function.
481 * If the callback function calls peel_ref(), then peel_ref() first
482 * checks whether the reference to be peeled is the one referred to by
483 * the iterator (it usually is) and if so, asks the iterator for the
484 * peeled version of the reference if it is available. This avoids a
485 * refname lookup in a common case. current_ref_iter is set to NULL
486 * when the iteration is over.
488 extern struct ref_iterator
*current_ref_iter
;
491 * The common backend for the for_each_*ref* functions. Call fn for
492 * each reference in iter. If the iterator itself ever returns
493 * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop
494 * the iteration and return that value. Otherwise, return 0. In any
495 * case, free the iterator when done. This function is basically an
496 * adapter between the callback style of reference iteration and the
499 int do_for_each_ref_iterator(struct ref_iterator
*iter
,
500 each_ref_fn fn
, void *cb_data
);
503 * Only include per-worktree refs in a do_for_each_ref*() iteration.
504 * Normally this will be used with a files ref_store, since that's
505 * where all reference backends will presumably store their
508 #define DO_FOR_EACH_PER_WORKTREE_ONLY 0x02
514 /* ref_store_init flags */
515 #define REF_STORE_READ (1 << 0)
516 #define REF_STORE_WRITE (1 << 1) /* can perform update operations */
517 #define REF_STORE_ODB (1 << 2) /* has access to object database */
518 #define REF_STORE_MAIN (1 << 3)
519 #define REF_STORE_ALL_CAPS (REF_STORE_READ | \
525 * Initialize the ref_store for the specified gitdir. These functions
526 * should call base_ref_store_init() to initialize the shared part of
527 * the ref_store and to record the ref_store for later lookup.
529 typedef struct ref_store
*ref_store_init_fn(const char *gitdir
,
532 typedef int ref_init_db_fn(struct ref_store
*refs
, struct strbuf
*err
);
534 typedef int ref_transaction_prepare_fn(struct ref_store
*refs
,
535 struct ref_transaction
*transaction
,
538 typedef int ref_transaction_finish_fn(struct ref_store
*refs
,
539 struct ref_transaction
*transaction
,
542 typedef int ref_transaction_abort_fn(struct ref_store
*refs
,
543 struct ref_transaction
*transaction
,
546 typedef int ref_transaction_commit_fn(struct ref_store
*refs
,
547 struct ref_transaction
*transaction
,
550 typedef int pack_refs_fn(struct ref_store
*ref_store
, unsigned int flags
);
551 typedef int peel_ref_fn(struct ref_store
*ref_store
,
552 const char *refname
, unsigned char *sha1
);
553 typedef int create_symref_fn(struct ref_store
*ref_store
,
554 const char *ref_target
,
555 const char *refs_heads_master
,
557 typedef int delete_refs_fn(struct ref_store
*ref_store
, const char *msg
,
558 struct string_list
*refnames
, unsigned int flags
);
559 typedef int rename_ref_fn(struct ref_store
*ref_store
,
560 const char *oldref
, const char *newref
,
564 * Iterate over the references in `ref_store` whose names start with
565 * `prefix`. `prefix` is matched as a literal string, without regard
566 * for path separators. If prefix is NULL or the empty string, iterate
567 * over all references in `ref_store`.
569 typedef struct ref_iterator
*ref_iterator_begin_fn(
570 struct ref_store
*ref_store
,
571 const char *prefix
, unsigned int flags
);
573 /* reflog functions */
576 * Iterate over the references in the specified ref_store that have a
577 * reflog. The refs are iterated over in arbitrary order.
579 typedef struct ref_iterator
*reflog_iterator_begin_fn(
580 struct ref_store
*ref_store
);
582 typedef int for_each_reflog_ent_fn(struct ref_store
*ref_store
,
584 each_reflog_ent_fn fn
,
586 typedef int for_each_reflog_ent_reverse_fn(struct ref_store
*ref_store
,
588 each_reflog_ent_fn fn
,
590 typedef int reflog_exists_fn(struct ref_store
*ref_store
, const char *refname
);
591 typedef int create_reflog_fn(struct ref_store
*ref_store
, const char *refname
,
592 int force_create
, struct strbuf
*err
);
593 typedef int delete_reflog_fn(struct ref_store
*ref_store
, const char *refname
);
594 typedef int reflog_expire_fn(struct ref_store
*ref_store
,
595 const char *refname
, const unsigned char *sha1
,
597 reflog_expiry_prepare_fn prepare_fn
,
598 reflog_expiry_should_prune_fn should_prune_fn
,
599 reflog_expiry_cleanup_fn cleanup_fn
,
600 void *policy_cb_data
);
603 * Read a reference from the specified reference store, non-recursively.
604 * Set type to describe the reference, and:
606 * - If refname is the name of a normal reference, fill in sha1
607 * (leaving referent unchanged).
609 * - If refname is the name of a symbolic reference, write the full
610 * name of the reference to which it refers (e.g.
611 * "refs/heads/master") to referent and set the REF_ISSYMREF bit in
612 * type (leaving sha1 unchanged). The caller is responsible for
613 * validating that referent is a valid reference name.
615 * WARNING: refname might be used as part of a filename, so it is
616 * important from a security standpoint that it be safe in the sense
617 * of refname_is_safe(). Moreover, for symrefs this function sets
618 * referent to whatever the repository says, which might not be a
619 * properly-formatted or even safe reference name. NEITHER INPUT NOR
620 * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION.
622 * Return 0 on success. If the ref doesn't exist, set errno to ENOENT
623 * and return -1. If the ref exists but is neither a symbolic ref nor
624 * a sha1, it is broken; set REF_ISBROKEN in type, set errno to
625 * EINVAL, and return -1. If there is another error reading the ref,
626 * set errno appropriately and return -1.
628 * Backend-specific flags might be set in type as well, regardless of
631 * It is OK for refname to point into referent. If so:
633 * - if the function succeeds with REF_ISSYMREF, referent will be
634 * overwritten and the memory formerly pointed to by it might be
635 * changed or even freed.
637 * - in all other cases, referent will be untouched, and therefore
638 * refname will still be valid and unchanged.
640 typedef int read_raw_ref_fn(struct ref_store
*ref_store
,
641 const char *refname
, unsigned char *sha1
,
642 struct strbuf
*referent
, unsigned int *type
);
644 struct ref_storage_be
{
645 struct ref_storage_be
*next
;
647 ref_store_init_fn
*init
;
648 ref_init_db_fn
*init_db
;
650 ref_transaction_prepare_fn
*transaction_prepare
;
651 ref_transaction_finish_fn
*transaction_finish
;
652 ref_transaction_abort_fn
*transaction_abort
;
653 ref_transaction_commit_fn
*initial_transaction_commit
;
655 pack_refs_fn
*pack_refs
;
656 peel_ref_fn
*peel_ref
;
657 create_symref_fn
*create_symref
;
658 delete_refs_fn
*delete_refs
;
659 rename_ref_fn
*rename_ref
;
661 ref_iterator_begin_fn
*iterator_begin
;
662 read_raw_ref_fn
*read_raw_ref
;
664 reflog_iterator_begin_fn
*reflog_iterator_begin
;
665 for_each_reflog_ent_fn
*for_each_reflog_ent
;
666 for_each_reflog_ent_reverse_fn
*for_each_reflog_ent_reverse
;
667 reflog_exists_fn
*reflog_exists
;
668 create_reflog_fn
*create_reflog
;
669 delete_reflog_fn
*delete_reflog
;
670 reflog_expire_fn
*reflog_expire
;
673 extern struct ref_storage_be refs_be_files
;
674 extern struct ref_storage_be refs_be_packed
;
677 * A representation of the reference store for the main repository or
678 * a submodule. The ref_store instances for submodules are kept in a
682 /* The backend describing this ref_store's storage scheme: */
683 const struct ref_storage_be
*be
;
687 * Fill in the generic part of refs and add it to our collection of
690 void base_ref_store_init(struct ref_store
*refs
,
691 const struct ref_storage_be
*be
);
693 #endif /* REFS_REFS_INTERNAL_H */