3 #include "refs-internal.h"
4 #include "../iterator.h"
5 #include "../dir-iterator.h"
6 #include "../lockfile.h"
13 struct object_id old_oid;
19 * Information used (along with the information in ref_entry) to
20 * describe a single cached reference. This data structure only
21 * occurs embedded in a union in struct ref_entry, and only when
22 * (ref_entry->flag & REF_DIR) is zero.
26 * The name of the object to which this reference resolves
27 * (which may be a tag object). If REF_ISBROKEN, this is
28 * null. If REF_ISSYMREF, then this is the name of the object
29 * referred to by the last reference in the symlink chain.
34 * If REF_KNOWS_PEELED, then this field holds the peeled value
35 * of this reference, or null if the reference is known not to
36 * be peelable. See the documentation for peel_ref() for an
37 * exact definition of "peelable".
39 struct object_id peeled;
42 struct files_ref_store;
45 * Information used (along with the information in ref_entry) to
46 * describe a level in the hierarchy of references. This data
47 * structure only occurs embedded in a union in struct ref_entry, and
48 * only when (ref_entry.flag & REF_DIR) is set. In that case,
49 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
50 * in the directory have already been read:
52 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
53 * or packed references, already read.
55 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
56 * references that hasn't been read yet (nor has any of its
59 * Entries within a directory are stored within a growable array of
60 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
61 * sorted are sorted by their component name in strcmp() order and the
62 * remaining entries are unsorted.
64 * Loose references are read lazily, one directory at a time. When a
65 * directory of loose references is read, then all of the references
66 * in that directory are stored, and REF_INCOMPLETE stubs are created
67 * for any subdirectories, but the subdirectories themselves are not
68 * read. The reading is triggered by get_ref_dir().
74 * Entries with index 0 <= i < sorted are sorted by name. New
75 * entries are appended to the list unsorted, and are sorted
76 * only when required; thus we avoid the need to sort the list
77 * after the addition of every reference.
81 /* A pointer to the files_ref_store that contains this ref_dir. */
82 struct files_ref_store *ref_store;
84 struct ref_entry **entries;
88 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
89 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are
90 * public values; see refs.h.
94 * The field ref_entry->u.value.peeled of this value entry contains
95 * the correct peeled value for the reference, which might be
96 * null_sha1 if the reference is not a tag or if it is broken.
98 #define REF_KNOWS_PEELED 0x10
100 /* ref_entry represents a directory of references */
104 * Entry has not yet been read from disk (used only for REF_DIR
105 * entries representing loose references)
107 #define REF_INCOMPLETE 0x40
110 * A ref_entry represents either a reference or a "subdirectory" of
113 * Each directory in the reference namespace is represented by a
114 * ref_entry with (flags & REF_DIR) set and containing a subdir member
115 * that holds the entries in that directory that have been read so
116 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
117 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
118 * used for loose reference directories.
120 * References are represented by a ref_entry with (flags & REF_DIR)
121 * unset and a value member that describes the reference's value. The
122 * flag member is at the ref_entry level, but it is also needed to
123 * interpret the contents of the value field (in other words, a
124 * ref_value object is not very much use without the enclosing
127 * Reference names cannot end with slash and directories' names are
128 * always stored with a trailing slash (except for the top-level
129 * directory, which is always denoted by ""). This has two nice
130 * consequences: (1) when the entries in each subdir are sorted
131 * lexicographically by name (as they usually are), the references in
132 * a whole tree can be generated in lexicographic order by traversing
133 * the tree in left-to-right, depth-first order; (2) the names of
134 * references and subdirectories cannot conflict, and therefore the
135 * presence of an empty subdirectory does not block the creation of a
136 * similarly-named reference. (The fact that reference names with the
137 * same leading components can conflict *with each other* is a
138 * separate issue that is regulated by verify_refname_available().)
140 * Please note that the name field contains the fully-qualified
141 * reference (or subdirectory) name. Space could be saved by only
142 * storing the relative names. But that would require the full names
143 * to be generated on the fly when iterating in do_for_each_ref(), and
144 * would break callback functions, who have always been able to assume
145 * that the name strings that they are passed will not be freed during
149 unsigned char flag; /* ISSYMREF? ISPACKED? */
151 struct ref_value value; /* if not (flags&REF_DIR) */
152 struct ref_dir subdir; /* if (flags&REF_DIR) */
155 * The full name of the reference (e.g., "refs/heads/master")
156 * or the full name of the directory with a trailing slash
157 * (e.g., "refs/heads/"):
159 char name[FLEX_ARRAY];
162 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
163 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len);
164 static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store,
165 const char *dirname, size_t len,
167 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry);
169 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
172 assert(entry->flag & REF_DIR);
173 dir = &entry->u.subdir;
174 if (entry->flag & REF_INCOMPLETE) {
175 read_loose_refs(entry->name, dir);
178 * Manually add refs/bisect, which, being
179 * per-worktree, might not appear in the directory
180 * listing for refs/ in the main repo.
182 if (!strcmp(entry->name, "refs/")) {
183 int pos = search_ref_dir(dir, "refs/bisect/", 12);
185 struct ref_entry *child_entry;
186 child_entry = create_dir_entry(dir->ref_store,
189 add_entry_to_dir(dir, child_entry);
190 read_loose_refs("refs/bisect",
191 &child_entry->u.subdir);
194 entry->flag &= ~REF_INCOMPLETE;
199 static struct ref_entry *create_ref_entry(const char *refname,
200 const unsigned char *sha1, int flag,
203 struct ref_entry *ref;
206 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
207 die("Reference has invalid format: '%s'", refname);
208 FLEX_ALLOC_STR(ref, name, refname);
209 hashcpy(ref->u.value.oid.hash, sha1);
210 oidclr(&ref->u.value.peeled);
215 static void clear_ref_dir(struct ref_dir *dir);
217 static void free_ref_entry(struct ref_entry *entry)
219 if (entry->flag & REF_DIR) {
221 * Do not use get_ref_dir() here, as that might
222 * trigger the reading of loose refs.
224 clear_ref_dir(&entry->u.subdir);
230 * Add a ref_entry to the end of dir (unsorted). Entry is always
231 * stored directly in dir; no recursion into subdirectories is
234 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
236 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
237 dir->entries[dir->nr++] = entry;
238 /* optimize for the case that entries are added in order */
240 (dir->nr == dir->sorted + 1 &&
241 strcmp(dir->entries[dir->nr - 2]->name,
242 dir->entries[dir->nr - 1]->name) < 0))
243 dir->sorted = dir->nr;
247 * Clear and free all entries in dir, recursively.
249 static void clear_ref_dir(struct ref_dir *dir)
252 for (i = 0; i < dir->nr; i++)
253 free_ref_entry(dir->entries[i]);
255 dir->sorted = dir->nr = dir->alloc = 0;
260 * Create a struct ref_entry object for the specified dirname.
261 * dirname is the name of the directory with a trailing slash (e.g.,
262 * "refs/heads/") or "" for the top-level directory.
264 static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store,
265 const char *dirname, size_t len,
268 struct ref_entry *direntry;
269 FLEX_ALLOC_MEM(direntry, name, dirname, len);
270 direntry->u.subdir.ref_store = ref_store;
271 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
275 static int ref_entry_cmp(const void *a, const void *b)
277 struct ref_entry *one = *(struct ref_entry **)a;
278 struct ref_entry *two = *(struct ref_entry **)b;
279 return strcmp(one->name, two->name);
282 static void sort_ref_dir(struct ref_dir *dir);
284 struct string_slice {
289 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
291 const struct string_slice *key = key_;
292 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
293 int cmp = strncmp(key->str, ent->name, key->len);
296 return '\0' - (unsigned char)ent->name[key->len];
300 * Return the index of the entry with the given refname from the
301 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
302 * no such entry is found. dir must already be complete.
304 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
306 struct ref_entry **r;
307 struct string_slice key;
309 if (refname == NULL || !dir->nr)
315 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
316 ref_entry_cmp_sslice);
321 return r - dir->entries;
325 * Search for a directory entry directly within dir (without
326 * recursing). Sort dir if necessary. subdirname must be a directory
327 * name (i.e., end in '/'). If mkdir is set, then create the
328 * directory if it is missing; otherwise, return NULL if the desired
329 * directory cannot be found. dir must already be complete.
331 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
332 const char *subdirname, size_t len,
335 int entry_index = search_ref_dir(dir, subdirname, len);
336 struct ref_entry *entry;
337 if (entry_index == -1) {
341 * Since dir is complete, the absence of a subdir
342 * means that the subdir really doesn't exist;
343 * therefore, create an empty record for it but mark
344 * the record complete.
346 entry = create_dir_entry(dir->ref_store, subdirname, len, 0);
347 add_entry_to_dir(dir, entry);
349 entry = dir->entries[entry_index];
351 return get_ref_dir(entry);
355 * If refname is a reference name, find the ref_dir within the dir
356 * tree that should hold refname. If refname is a directory name
357 * (i.e., ends in '/'), then return that ref_dir itself. dir must
358 * represent the top-level directory and must already be complete.
359 * Sort ref_dirs and recurse into subdirectories as necessary. If
360 * mkdir is set, then create any missing directories; otherwise,
361 * return NULL if the desired directory cannot be found.
363 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
364 const char *refname, int mkdir)
367 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
368 size_t dirnamelen = slash - refname + 1;
369 struct ref_dir *subdir;
370 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
382 * Find the value entry with the given name in dir, sorting ref_dirs
383 * and recursing into subdirectories as necessary. If the name is not
384 * found or it corresponds to a directory entry, return NULL.
386 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
389 struct ref_entry *entry;
390 dir = find_containing_dir(dir, refname, 0);
393 entry_index = search_ref_dir(dir, refname, strlen(refname));
394 if (entry_index == -1)
396 entry = dir->entries[entry_index];
397 return (entry->flag & REF_DIR) ? NULL : entry;
401 * Remove the entry with the given name from dir, recursing into
402 * subdirectories as necessary. If refname is the name of a directory
403 * (i.e., ends with '/'), then remove the directory and its contents.
404 * If the removal was successful, return the number of entries
405 * remaining in the directory entry that contained the deleted entry.
406 * If the name was not found, return -1. Please note that this
407 * function only deletes the entry from the cache; it does not delete
408 * it from the filesystem or ensure that other cache entries (which
409 * might be symbolic references to the removed entry) are updated.
410 * Nor does it remove any containing dir entries that might be made
411 * empty by the removal. dir must represent the top-level directory
412 * and must already be complete.
414 static int remove_entry(struct ref_dir *dir, const char *refname)
416 int refname_len = strlen(refname);
418 struct ref_entry *entry;
419 int is_dir = refname[refname_len - 1] == '/';
422 * refname represents a reference directory. Remove
423 * the trailing slash; otherwise we will get the
424 * directory *representing* refname rather than the
425 * one *containing* it.
427 char *dirname = xmemdupz(refname, refname_len - 1);
428 dir = find_containing_dir(dir, dirname, 0);
431 dir = find_containing_dir(dir, refname, 0);
435 entry_index = search_ref_dir(dir, refname, refname_len);
436 if (entry_index == -1)
438 entry = dir->entries[entry_index];
440 memmove(&dir->entries[entry_index],
441 &dir->entries[entry_index + 1],
442 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
445 if (dir->sorted > entry_index)
447 free_ref_entry(entry);
452 * Add a ref_entry to the ref_dir (unsorted), recursing into
453 * subdirectories as necessary. dir must represent the top-level
454 * directory. Return 0 on success.
456 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
458 dir = find_containing_dir(dir, ref->name, 1);
461 add_entry_to_dir(dir, ref);
466 * Emit a warning and return true iff ref1 and ref2 have the same name
467 * and the same sha1. Die if they have the same name but different
470 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
472 if (strcmp(ref1->name, ref2->name))
475 /* Duplicate name; make sure that they don't conflict: */
477 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
478 /* This is impossible by construction */
479 die("Reference directory conflict: %s", ref1->name);
481 if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid))
482 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
484 warning("Duplicated ref: %s", ref1->name);
489 * Sort the entries in dir non-recursively (if they are not already
490 * sorted) and remove any duplicate entries.
492 static void sort_ref_dir(struct ref_dir *dir)
495 struct ref_entry *last = NULL;
498 * This check also prevents passing a zero-length array to qsort(),
499 * which is a problem on some platforms.
501 if (dir->sorted == dir->nr)
504 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
506 /* Remove any duplicates: */
507 for (i = 0, j = 0; j < dir->nr; j++) {
508 struct ref_entry *entry = dir->entries[j];
509 if (last && is_dup_ref(last, entry))
510 free_ref_entry(entry);
512 last = dir->entries[i++] = entry;
514 dir->sorted = dir->nr = i;
518 * Return true if refname, which has the specified oid and flags, can
519 * be resolved to an object in the database. If the referred-to object
520 * does not exist, emit a warning and return false.
522 static int ref_resolves_to_object(const char *refname,
523 const struct object_id *oid,
526 if (flags & REF_ISBROKEN)
528 if (!has_sha1_file(oid->hash)) {
529 error("%s does not point to a valid object!", refname);
536 * Return true if the reference described by entry can be resolved to
537 * an object in the database; otherwise, emit a warning and return
540 static int entry_resolves_to_object(struct ref_entry *entry)
542 return ref_resolves_to_object(entry->name,
543 &entry->u.value.oid, entry->flag);
546 typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
549 * Call fn for each reference in dir that has index in the range
550 * offset <= index < dir->nr. Recurse into subdirectories that are in
551 * that index range, sorting them before iterating. This function
552 * does not sort dir itself; it should be sorted beforehand. fn is
553 * called for all references, including broken ones.
555 static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
556 each_ref_entry_fn fn, void *cb_data)
559 assert(dir->sorted == dir->nr);
560 for (i = offset; i < dir->nr; i++) {
561 struct ref_entry *entry = dir->entries[i];
563 if (entry->flag & REF_DIR) {
564 struct ref_dir *subdir = get_ref_dir(entry);
565 sort_ref_dir(subdir);
566 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
568 retval = fn(entry, cb_data);
577 * Load all of the refs from the dir into our in-memory cache. The hard work
578 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
579 * through all of the sub-directories. We do not even need to care about
580 * sorting, as traversal order does not matter to us.
582 static void prime_ref_dir(struct ref_dir *dir)
585 for (i = 0; i < dir->nr; i++) {
586 struct ref_entry *entry = dir->entries[i];
587 if (entry->flag & REF_DIR)
588 prime_ref_dir(get_ref_dir(entry));
593 * A level in the reference hierarchy that is currently being iterated
596 struct cache_ref_iterator_level {
598 * The ref_dir being iterated over at this level. The ref_dir
599 * is sorted before being stored here.
604 * The index of the current entry within dir (which might
605 * itself be a directory). If index == -1, then the iteration
606 * hasn't yet begun. If index == dir->nr, then the iteration
607 * through this level is over.
613 * Represent an iteration through a ref_dir in the memory cache. The
614 * iteration recurses through subdirectories.
616 struct cache_ref_iterator {
617 struct ref_iterator base;
620 * The number of levels currently on the stack. This is always
621 * at least 1, because when it becomes zero the iteration is
622 * ended and this struct is freed.
626 /* The number of levels that have been allocated on the stack */
630 * A stack of levels. levels[0] is the uppermost level that is
631 * being iterated over in this iteration. (This is not
632 * necessary the top level in the references hierarchy. If we
633 * are iterating through a subtree, then levels[0] will hold
634 * the ref_dir for that subtree, and subsequent levels will go
637 struct cache_ref_iterator_level *levels;
640 static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator)
642 struct cache_ref_iterator *iter =
643 (struct cache_ref_iterator *)ref_iterator;
646 struct cache_ref_iterator_level *level =
647 &iter->levels[iter->levels_nr - 1];
648 struct ref_dir *dir = level->dir;
649 struct ref_entry *entry;
651 if (level->index == -1)
654 if (++level->index == level->dir->nr) {
655 /* This level is exhausted; pop up a level */
656 if (--iter->levels_nr == 0)
657 return ref_iterator_abort(ref_iterator);
662 entry = dir->entries[level->index];
664 if (entry->flag & REF_DIR) {
665 /* push down a level */
666 ALLOC_GROW(iter->levels, iter->levels_nr + 1,
669 level = &iter->levels[iter->levels_nr++];
670 level->dir = get_ref_dir(entry);
673 iter->base.refname = entry->name;
674 iter->base.oid = &entry->u.value.oid;
675 iter->base.flags = entry->flag;
681 static enum peel_status peel_entry(struct ref_entry *entry, int repeel);
683 static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator,
684 struct object_id *peeled)
686 struct cache_ref_iterator *iter =
687 (struct cache_ref_iterator *)ref_iterator;
688 struct cache_ref_iterator_level *level;
689 struct ref_entry *entry;
691 level = &iter->levels[iter->levels_nr - 1];
693 if (level->index == -1)
694 die("BUG: peel called before advance for cache iterator");
696 entry = level->dir->entries[level->index];
698 if (peel_entry(entry, 0))
700 hashcpy(peeled->hash, entry->u.value.peeled.hash);
704 static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator)
706 struct cache_ref_iterator *iter =
707 (struct cache_ref_iterator *)ref_iterator;
710 base_ref_iterator_free(ref_iterator);
714 static struct ref_iterator_vtable cache_ref_iterator_vtable = {
715 cache_ref_iterator_advance,
716 cache_ref_iterator_peel,
717 cache_ref_iterator_abort
720 static struct ref_iterator *cache_ref_iterator_begin(struct ref_dir *dir)
722 struct cache_ref_iterator *iter;
723 struct ref_iterator *ref_iterator;
724 struct cache_ref_iterator_level *level;
726 iter = xcalloc(1, sizeof(*iter));
727 ref_iterator = &iter->base;
728 base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable);
729 ALLOC_GROW(iter->levels, 10, iter->levels_alloc);
732 level = &iter->levels[0];
739 struct nonmatching_ref_data {
740 const struct string_list *skip;
741 const char *conflicting_refname;
744 static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata)
746 struct nonmatching_ref_data *data = vdata;
748 if (data->skip && string_list_has_string(data->skip, entry->name))
751 data->conflicting_refname = entry->name;
756 * Return 0 if a reference named refname could be created without
757 * conflicting with the name of an existing reference in dir.
758 * See verify_refname_available for more information.
760 static int verify_refname_available_dir(const char *refname,
761 const struct string_list *extras,
762 const struct string_list *skip,
767 const char *extra_refname;
769 struct strbuf dirname = STRBUF_INIT;
773 * For the sake of comments in this function, suppose that
774 * refname is "refs/foo/bar".
779 strbuf_grow(&dirname, strlen(refname) + 1);
780 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
781 /* Expand dirname to the new prefix, not including the trailing slash: */
782 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
785 * We are still at a leading dir of the refname (e.g.,
786 * "refs/foo"; if there is a reference with that name,
787 * it is a conflict, *unless* it is in skip.
790 pos = search_ref_dir(dir, dirname.buf, dirname.len);
792 (!skip || !string_list_has_string(skip, dirname.buf))) {
794 * We found a reference whose name is
795 * a proper prefix of refname; e.g.,
796 * "refs/foo", and is not in skip.
798 strbuf_addf(err, "'%s' exists; cannot create '%s'",
799 dirname.buf, refname);
804 if (extras && string_list_has_string(extras, dirname.buf) &&
805 (!skip || !string_list_has_string(skip, dirname.buf))) {
806 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
807 refname, dirname.buf);
812 * Otherwise, we can try to continue our search with
813 * the next component. So try to look up the
814 * directory, e.g., "refs/foo/". If we come up empty,
815 * we know there is nothing under this whole prefix,
816 * but even in that case we still have to continue the
817 * search for conflicts with extras.
819 strbuf_addch(&dirname, '/');
821 pos = search_ref_dir(dir, dirname.buf, dirname.len);
824 * There was no directory "refs/foo/",
825 * so there is nothing under this
826 * whole prefix. So there is no need
827 * to continue looking for conflicting
828 * references. But we need to continue
829 * looking for conflicting extras.
833 dir = get_ref_dir(dir->entries[pos]);
839 * We are at the leaf of our refname (e.g., "refs/foo/bar").
840 * There is no point in searching for a reference with that
841 * name, because a refname isn't considered to conflict with
842 * itself. But we still need to check for references whose
843 * names are in the "refs/foo/bar/" namespace, because they
846 strbuf_addstr(&dirname, refname + dirname.len);
847 strbuf_addch(&dirname, '/');
850 pos = search_ref_dir(dir, dirname.buf, dirname.len);
854 * We found a directory named "$refname/"
855 * (e.g., "refs/foo/bar/"). It is a problem
856 * iff it contains any ref that is not in
859 struct nonmatching_ref_data data;
862 data.conflicting_refname = NULL;
863 dir = get_ref_dir(dir->entries[pos]);
865 if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) {
866 strbuf_addf(err, "'%s' exists; cannot create '%s'",
867 data.conflicting_refname, refname);
873 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
875 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
876 refname, extra_refname);
881 strbuf_release(&dirname);
885 struct packed_ref_cache {
886 struct ref_entry *root;
889 * Count of references to the data structure in this instance,
890 * including the pointer from files_ref_store::packed if any.
891 * The data will not be freed as long as the reference count
894 unsigned int referrers;
897 * Iff the packed-refs file associated with this instance is
898 * currently locked for writing, this points at the associated
899 * lock (which is owned by somebody else). The referrer count
900 * is also incremented when the file is locked and decremented
901 * when it is unlocked.
903 struct lock_file *lock;
905 /* The metadata from when this packed-refs cache was read */
906 struct stat_validity validity;
910 * Future: need to be in "struct repository"
911 * when doing a full libification.
913 struct files_ref_store {
914 struct ref_store base;
915 struct ref_entry *loose;
916 struct packed_ref_cache *packed;
919 /* Lock used for the main packed-refs file: */
920 static struct lock_file packlock;
923 * Increment the reference count of *packed_refs.
925 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
927 packed_refs->referrers++;
931 * Decrease the reference count of *packed_refs. If it goes to zero,
932 * free *packed_refs and return true; otherwise return false.
934 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
936 if (!--packed_refs->referrers) {
937 free_ref_entry(packed_refs->root);
938 stat_validity_clear(&packed_refs->validity);
946 static void clear_packed_ref_cache(struct files_ref_store *refs)
949 struct packed_ref_cache *packed_refs = refs->packed;
951 if (packed_refs->lock)
952 die("internal error: packed-ref cache cleared while locked");
954 release_packed_ref_cache(packed_refs);
958 static void clear_loose_ref_cache(struct files_ref_store *refs)
961 free_ref_entry(refs->loose);
967 * Create a new submodule ref cache and add it to the internal
970 static struct ref_store *files_ref_store_create(const char *submodule)
972 struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
973 struct ref_store *ref_store = (struct ref_store *)refs;
975 base_ref_store_init(ref_store, &refs_be_files, submodule);
981 * Downcast ref_store to files_ref_store. Die if ref_store is not a
982 * files_ref_store. If submodule_allowed is not true, then also die if
983 * files_ref_store is for a submodule (i.e., not for the main
984 * repository). caller is used in any necessary error messages.
986 static struct files_ref_store *files_downcast(
987 struct ref_store *ref_store, int submodule_allowed,
990 if (ref_store->be != &refs_be_files)
991 die("BUG: ref_store is type \"%s\" not \"files\" in %s",
992 ref_store->be->name, caller);
994 if (!submodule_allowed)
995 assert_main_repository(ref_store, caller);
997 return (struct files_ref_store *)ref_store;
1000 /* The length of a peeled reference line in packed-refs, including EOL: */
1001 #define PEELED_LINE_LENGTH 42
1004 * The packed-refs header line that we write out. Perhaps other
1005 * traits will be added later. The trailing space is required.
1007 static const char PACKED_REFS_HEADER[] =
1008 "# pack-refs with: peeled fully-peeled \n";
1011 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
1012 * Return a pointer to the refname within the line (null-terminated),
1013 * or NULL if there was a problem.
1015 static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1)
1020 * 42: the answer to everything.
1022 * In this case, it happens to be the answer to
1023 * 40 (length of sha1 hex representation)
1024 * +1 (space in between hex and name)
1025 * +1 (newline at the end of the line)
1027 if (line->len <= 42)
1030 if (get_sha1_hex(line->buf, sha1) < 0)
1032 if (!isspace(line->buf[40]))
1035 ref = line->buf + 41;
1039 if (line->buf[line->len - 1] != '\n')
1041 line->buf[--line->len] = 0;
1047 * Read f, which is a packed-refs file, into dir.
1049 * A comment line of the form "# pack-refs with: " may contain zero or
1050 * more traits. We interpret the traits as follows:
1054 * Probably no references are peeled. But if the file contains a
1055 * peeled value for a reference, we will use it.
1059 * References under "refs/tags/", if they *can* be peeled, *are*
1060 * peeled in this file. References outside of "refs/tags/" are
1061 * probably not peeled even if they could have been, but if we find
1062 * a peeled value for such a reference we will use it.
1066 * All references in the file that can be peeled are peeled.
1067 * Inversely (and this is more important), any references in the
1068 * file for which no peeled value is recorded is not peelable. This
1069 * trait should typically be written alongside "peeled" for
1070 * compatibility with older clients, but we do not require it
1071 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1073 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1075 struct ref_entry *last = NULL;
1076 struct strbuf line = STRBUF_INIT;
1077 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1079 while (strbuf_getwholeline(&line, f, '\n') != EOF) {
1080 unsigned char sha1[20];
1081 const char *refname;
1084 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
1085 if (strstr(traits, " fully-peeled "))
1086 peeled = PEELED_FULLY;
1087 else if (strstr(traits, " peeled "))
1088 peeled = PEELED_TAGS;
1089 /* perhaps other traits later as well */
1093 refname = parse_ref_line(&line, sha1);
1095 int flag = REF_ISPACKED;
1097 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1098 if (!refname_is_safe(refname))
1099 die("packed refname is dangerous: %s", refname);
1101 flag |= REF_BAD_NAME | REF_ISBROKEN;
1103 last = create_ref_entry(refname, sha1, flag, 0);
1104 if (peeled == PEELED_FULLY ||
1105 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1106 last->flag |= REF_KNOWS_PEELED;
1111 line.buf[0] == '^' &&
1112 line.len == PEELED_LINE_LENGTH &&
1113 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&
1114 !get_sha1_hex(line.buf + 1, sha1)) {
1115 hashcpy(last->u.value.peeled.hash, sha1);
1117 * Regardless of what the file header said,
1118 * we definitely know the value of *this*
1121 last->flag |= REF_KNOWS_PEELED;
1125 strbuf_release(&line);
1129 * Get the packed_ref_cache for the specified files_ref_store,
1130 * creating it if necessary.
1132 static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)
1134 char *packed_refs_file;
1136 if (*refs->base.submodule)
1137 packed_refs_file = git_pathdup_submodule(refs->base.submodule,
1140 packed_refs_file = git_pathdup("packed-refs");
1143 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1144 clear_packed_ref_cache(refs);
1146 if (!refs->packed) {
1149 refs->packed = xcalloc(1, sizeof(*refs->packed));
1150 acquire_packed_ref_cache(refs->packed);
1151 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1152 f = fopen(packed_refs_file, "r");
1154 stat_validity_update(&refs->packed->validity, fileno(f));
1155 read_packed_refs(f, get_ref_dir(refs->packed->root));
1159 free(packed_refs_file);
1160 return refs->packed;
1163 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1165 return get_ref_dir(packed_ref_cache->root);
1168 static struct ref_dir *get_packed_refs(struct files_ref_store *refs)
1170 return get_packed_ref_dir(get_packed_ref_cache(refs));
1174 * Add a reference to the in-memory packed reference cache. This may
1175 * only be called while the packed-refs file is locked (see
1176 * lock_packed_refs()). To actually write the packed-refs file, call
1177 * commit_packed_refs().
1179 static void add_packed_ref(struct files_ref_store *refs,
1180 const char *refname, const unsigned char *sha1)
1182 struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs);
1184 if (!packed_ref_cache->lock)
1185 die("internal error: packed refs not locked");
1186 add_ref(get_packed_ref_dir(packed_ref_cache),
1187 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1191 * Read the loose references from the namespace dirname into dir
1192 * (without recursing). dirname must end with '/'. dir must be the
1193 * directory entry corresponding to dirname.
1195 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1197 struct files_ref_store *refs = dir->ref_store;
1200 int dirnamelen = strlen(dirname);
1201 struct strbuf refname;
1202 struct strbuf path = STRBUF_INIT;
1203 size_t path_baselen;
1206 if (*refs->base.submodule)
1207 err = strbuf_git_path_submodule(&path, refs->base.submodule, "%s", dirname);
1209 strbuf_git_path(&path, "%s", dirname);
1210 path_baselen = path.len;
1213 strbuf_release(&path);
1217 d = opendir(path.buf);
1219 strbuf_release(&path);
1223 strbuf_init(&refname, dirnamelen + 257);
1224 strbuf_add(&refname, dirname, dirnamelen);
1226 while ((de = readdir(d)) != NULL) {
1227 unsigned char sha1[20];
1231 if (de->d_name[0] == '.')
1233 if (ends_with(de->d_name, ".lock"))
1235 strbuf_addstr(&refname, de->d_name);
1236 strbuf_addstr(&path, de->d_name);
1237 if (stat(path.buf, &st) < 0) {
1238 ; /* silently ignore */
1239 } else if (S_ISDIR(st.st_mode)) {
1240 strbuf_addch(&refname, '/');
1241 add_entry_to_dir(dir,
1242 create_dir_entry(refs, refname.buf,
1247 if (*refs->base.submodule) {
1250 read_ok = !resolve_gitlink_ref(refs->base.submodule,
1253 read_ok = !read_ref_full(refname.buf,
1254 RESOLVE_REF_READING,
1260 flag |= REF_ISBROKEN;
1261 } else if (is_null_sha1(sha1)) {
1263 * It is so astronomically unlikely
1264 * that NULL_SHA1 is the SHA-1 of an
1265 * actual object that we consider its
1266 * appearance in a loose reference
1267 * file to be repo corruption
1268 * (probably due to a software bug).
1270 flag |= REF_ISBROKEN;
1273 if (check_refname_format(refname.buf,
1274 REFNAME_ALLOW_ONELEVEL)) {
1275 if (!refname_is_safe(refname.buf))
1276 die("loose refname is dangerous: %s", refname.buf);
1278 flag |= REF_BAD_NAME | REF_ISBROKEN;
1280 add_entry_to_dir(dir,
1281 create_ref_entry(refname.buf, sha1, flag, 0));
1283 strbuf_setlen(&refname, dirnamelen);
1284 strbuf_setlen(&path, path_baselen);
1286 strbuf_release(&refname);
1287 strbuf_release(&path);
1291 static struct ref_dir *get_loose_refs(struct files_ref_store *refs)
1295 * Mark the top-level directory complete because we
1296 * are about to read the only subdirectory that can
1299 refs->loose = create_dir_entry(refs, "", 0, 0);
1301 * Create an incomplete entry for "refs/":
1303 add_entry_to_dir(get_ref_dir(refs->loose),
1304 create_dir_entry(refs, "refs/", 5, 1));
1306 return get_ref_dir(refs->loose);
1310 * Return the ref_entry for the given refname from the packed
1311 * references. If it does not exist, return NULL.
1313 static struct ref_entry *get_packed_ref(struct files_ref_store *refs,
1314 const char *refname)
1316 return find_ref(get_packed_refs(refs), refname);
1320 * A loose ref file doesn't exist; check for a packed ref.
1322 static int resolve_packed_ref(struct files_ref_store *refs,
1323 const char *refname,
1324 unsigned char *sha1, unsigned int *flags)
1326 struct ref_entry *entry;
1329 * The loose reference file does not exist; check for a packed
1332 entry = get_packed_ref(refs, refname);
1334 hashcpy(sha1, entry->u.value.oid.hash);
1335 *flags |= REF_ISPACKED;
1338 /* refname is not a packed reference. */
1342 static int files_read_raw_ref(struct ref_store *ref_store,
1343 const char *refname, unsigned char *sha1,
1344 struct strbuf *referent, unsigned int *type)
1346 struct files_ref_store *refs =
1347 files_downcast(ref_store, 1, "read_raw_ref");
1348 struct strbuf sb_contents = STRBUF_INIT;
1349 struct strbuf sb_path = STRBUF_INIT;
1358 strbuf_reset(&sb_path);
1360 if (*refs->base.submodule)
1361 strbuf_git_path_submodule(&sb_path, refs->base.submodule, "%s", refname);
1363 strbuf_git_path(&sb_path, "%s", refname);
1369 * We might have to loop back here to avoid a race
1370 * condition: first we lstat() the file, then we try
1371 * to read it as a link or as a file. But if somebody
1372 * changes the type of the file (file <-> directory
1373 * <-> symlink) between the lstat() and reading, then
1374 * we don't want to report that as an error but rather
1375 * try again starting with the lstat().
1378 if (lstat(path, &st) < 0) {
1379 if (errno != ENOENT)
1381 if (resolve_packed_ref(refs, refname, sha1, type)) {
1389 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1390 if (S_ISLNK(st.st_mode)) {
1391 strbuf_reset(&sb_contents);
1392 if (strbuf_readlink(&sb_contents, path, 0) < 0) {
1393 if (errno == ENOENT || errno == EINVAL)
1394 /* inconsistent with lstat; retry */
1399 if (starts_with(sb_contents.buf, "refs/") &&
1400 !check_refname_format(sb_contents.buf, 0)) {
1401 strbuf_swap(&sb_contents, referent);
1402 *type |= REF_ISSYMREF;
1408 /* Is it a directory? */
1409 if (S_ISDIR(st.st_mode)) {
1411 * Even though there is a directory where the loose
1412 * ref is supposed to be, there could still be a
1415 if (resolve_packed_ref(refs, refname, sha1, type)) {
1424 * Anything else, just open it and try to use it as
1427 fd = open(path, O_RDONLY);
1429 if (errno == ENOENT)
1430 /* inconsistent with lstat; retry */
1435 strbuf_reset(&sb_contents);
1436 if (strbuf_read(&sb_contents, fd, 256) < 0) {
1437 int save_errno = errno;
1443 strbuf_rtrim(&sb_contents);
1444 buf = sb_contents.buf;
1445 if (starts_with(buf, "ref:")) {
1447 while (isspace(*buf))
1450 strbuf_reset(referent);
1451 strbuf_addstr(referent, buf);
1452 *type |= REF_ISSYMREF;
1458 * Please note that FETCH_HEAD has additional
1459 * data after the sha.
1461 if (get_sha1_hex(buf, sha1) ||
1462 (buf[40] != '\0' && !isspace(buf[40]))) {
1463 *type |= REF_ISBROKEN;
1472 strbuf_release(&sb_path);
1473 strbuf_release(&sb_contents);
1478 static void unlock_ref(struct ref_lock *lock)
1480 /* Do not free lock->lk -- atexit() still looks at them */
1482 rollback_lock_file(lock->lk);
1483 free(lock->ref_name);
1488 * Lock refname, without following symrefs, and set *lock_p to point
1489 * at a newly-allocated lock object. Fill in lock->old_oid, referent,
1490 * and type similarly to read_raw_ref().
1492 * The caller must verify that refname is a "safe" reference name (in
1493 * the sense of refname_is_safe()) before calling this function.
1495 * If the reference doesn't already exist, verify that refname doesn't
1496 * have a D/F conflict with any existing references. extras and skip
1497 * are passed to verify_refname_available_dir() for this check.
1499 * If mustexist is not set and the reference is not found or is
1500 * broken, lock the reference anyway but clear sha1.
1502 * Return 0 on success. On failure, write an error message to err and
1503 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
1505 * Implementation note: This function is basically
1510 * but it includes a lot more code to
1511 * - Deal with possible races with other processes
1512 * - Avoid calling verify_refname_available_dir() when it can be
1513 * avoided, namely if we were successfully able to read the ref
1514 * - Generate informative error messages in the case of failure
1516 static int lock_raw_ref(struct files_ref_store *refs,
1517 const char *refname, int mustexist,
1518 const struct string_list *extras,
1519 const struct string_list *skip,
1520 struct ref_lock **lock_p,
1521 struct strbuf *referent,
1525 struct ref_lock *lock;
1526 struct strbuf ref_file = STRBUF_INIT;
1527 int attempts_remaining = 3;
1528 int ret = TRANSACTION_GENERIC_ERROR;
1531 assert_main_repository(&refs->base, "lock_raw_ref");
1535 /* First lock the file so it can't change out from under us. */
1537 *lock_p = lock = xcalloc(1, sizeof(*lock));
1539 lock->ref_name = xstrdup(refname);
1540 strbuf_git_path(&ref_file, "%s", refname);
1543 switch (safe_create_leading_directories(ref_file.buf)) {
1545 break; /* success */
1548 * Suppose refname is "refs/foo/bar". We just failed
1549 * to create the containing directory, "refs/foo",
1550 * because there was a non-directory in the way. This
1551 * indicates a D/F conflict, probably because of
1552 * another reference such as "refs/foo". There is no
1553 * reason to expect this error to be transitory.
1555 if (verify_refname_available(refname, extras, skip, err)) {
1558 * To the user the relevant error is
1559 * that the "mustexist" reference is
1563 strbuf_addf(err, "unable to resolve reference '%s'",
1567 * The error message set by
1568 * verify_refname_available_dir() is OK.
1570 ret = TRANSACTION_NAME_CONFLICT;
1574 * The file that is in the way isn't a loose
1575 * reference. Report it as a low-level
1578 strbuf_addf(err, "unable to create lock file %s.lock; "
1579 "non-directory in the way",
1584 /* Maybe another process was tidying up. Try again. */
1585 if (--attempts_remaining > 0)
1589 strbuf_addf(err, "unable to create directory for %s",
1595 lock->lk = xcalloc(1, sizeof(struct lock_file));
1597 if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) {
1598 if (errno == ENOENT && --attempts_remaining > 0) {
1600 * Maybe somebody just deleted one of the
1601 * directories leading to ref_file. Try
1606 unable_to_lock_message(ref_file.buf, errno, err);
1612 * Now we hold the lock and can read the reference without
1613 * fear that its value will change.
1616 if (files_read_raw_ref(&refs->base, refname,
1617 lock->old_oid.hash, referent, type)) {
1618 if (errno == ENOENT) {
1620 /* Garden variety missing reference. */
1621 strbuf_addf(err, "unable to resolve reference '%s'",
1626 * Reference is missing, but that's OK. We
1627 * know that there is not a conflict with
1628 * another loose reference because
1629 * (supposing that we are trying to lock
1630 * reference "refs/foo/bar"):
1632 * - We were successfully able to create
1633 * the lockfile refs/foo/bar.lock, so we
1634 * know there cannot be a loose reference
1637 * - We got ENOENT and not EISDIR, so we
1638 * know that there cannot be a loose
1639 * reference named "refs/foo/bar/baz".
1642 } else if (errno == EISDIR) {
1644 * There is a directory in the way. It might have
1645 * contained references that have been deleted. If
1646 * we don't require that the reference already
1647 * exists, try to remove the directory so that it
1648 * doesn't cause trouble when we want to rename the
1649 * lockfile into place later.
1652 /* Garden variety missing reference. */
1653 strbuf_addf(err, "unable to resolve reference '%s'",
1656 } else if (remove_dir_recursively(&ref_file,
1657 REMOVE_DIR_EMPTY_ONLY)) {
1658 if (verify_refname_available_dir(
1659 refname, extras, skip,
1660 get_loose_refs(refs),
1663 * The error message set by
1664 * verify_refname_available() is OK.
1666 ret = TRANSACTION_NAME_CONFLICT;
1670 * We can't delete the directory,
1671 * but we also don't know of any
1672 * references that it should
1675 strbuf_addf(err, "there is a non-empty directory '%s' "
1676 "blocking reference '%s'",
1677 ref_file.buf, refname);
1681 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {
1682 strbuf_addf(err, "unable to resolve reference '%s': "
1683 "reference broken", refname);
1686 strbuf_addf(err, "unable to resolve reference '%s': %s",
1687 refname, strerror(errno));
1692 * If the ref did not exist and we are creating it,
1693 * make sure there is no existing packed ref whose
1694 * name begins with our refname, nor a packed ref
1695 * whose name is a proper prefix of our refname.
1697 if (verify_refname_available_dir(
1698 refname, extras, skip,
1699 get_packed_refs(refs),
1713 strbuf_release(&ref_file);
1718 * Peel the entry (if possible) and return its new peel_status. If
1719 * repeel is true, re-peel the entry even if there is an old peeled
1720 * value that is already stored in it.
1722 * It is OK to call this function with a packed reference entry that
1723 * might be stale and might even refer to an object that has since
1724 * been garbage-collected. In such a case, if the entry has
1725 * REF_KNOWS_PEELED then leave the status unchanged and return
1726 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1728 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1730 enum peel_status status;
1732 if (entry->flag & REF_KNOWS_PEELED) {
1734 entry->flag &= ~REF_KNOWS_PEELED;
1735 oidclr(&entry->u.value.peeled);
1737 return is_null_oid(&entry->u.value.peeled) ?
1738 PEEL_NON_TAG : PEEL_PEELED;
1741 if (entry->flag & REF_ISBROKEN)
1743 if (entry->flag & REF_ISSYMREF)
1744 return PEEL_IS_SYMREF;
1746 status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);
1747 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1748 entry->flag |= REF_KNOWS_PEELED;
1752 static int files_peel_ref(struct ref_store *ref_store,
1753 const char *refname, unsigned char *sha1)
1755 struct files_ref_store *refs = files_downcast(ref_store, 0, "peel_ref");
1757 unsigned char base[20];
1759 if (current_ref_iter && current_ref_iter->refname == refname) {
1760 struct object_id peeled;
1762 if (ref_iterator_peel(current_ref_iter, &peeled))
1764 hashcpy(sha1, peeled.hash);
1768 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))
1772 * If the reference is packed, read its ref_entry from the
1773 * cache in the hope that we already know its peeled value.
1774 * We only try this optimization on packed references because
1775 * (a) forcing the filling of the loose reference cache could
1776 * be expensive and (b) loose references anyway usually do not
1777 * have REF_KNOWS_PEELED.
1779 if (flag & REF_ISPACKED) {
1780 struct ref_entry *r = get_packed_ref(refs, refname);
1782 if (peel_entry(r, 0))
1784 hashcpy(sha1, r->u.value.peeled.hash);
1789 return peel_object(base, sha1);
1792 struct files_ref_iterator {
1793 struct ref_iterator base;
1795 struct packed_ref_cache *packed_ref_cache;
1796 struct ref_iterator *iter0;
1800 static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
1802 struct files_ref_iterator *iter =
1803 (struct files_ref_iterator *)ref_iterator;
1806 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
1807 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
1808 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
1811 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
1812 !ref_resolves_to_object(iter->iter0->refname,
1814 iter->iter0->flags))
1817 iter->base.refname = iter->iter0->refname;
1818 iter->base.oid = iter->iter0->oid;
1819 iter->base.flags = iter->iter0->flags;
1824 if (ref_iterator_abort(ref_iterator) != ITER_DONE)
1830 static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,
1831 struct object_id *peeled)
1833 struct files_ref_iterator *iter =
1834 (struct files_ref_iterator *)ref_iterator;
1836 return ref_iterator_peel(iter->iter0, peeled);
1839 static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)
1841 struct files_ref_iterator *iter =
1842 (struct files_ref_iterator *)ref_iterator;
1846 ok = ref_iterator_abort(iter->iter0);
1848 release_packed_ref_cache(iter->packed_ref_cache);
1849 base_ref_iterator_free(ref_iterator);
1853 static struct ref_iterator_vtable files_ref_iterator_vtable = {
1854 files_ref_iterator_advance,
1855 files_ref_iterator_peel,
1856 files_ref_iterator_abort
1859 static struct ref_iterator *files_ref_iterator_begin(
1860 struct ref_store *ref_store,
1861 const char *prefix, unsigned int flags)
1863 struct files_ref_store *refs =
1864 files_downcast(ref_store, 1, "ref_iterator_begin");
1865 struct ref_dir *loose_dir, *packed_dir;
1866 struct ref_iterator *loose_iter, *packed_iter;
1867 struct files_ref_iterator *iter;
1868 struct ref_iterator *ref_iterator;
1871 return empty_ref_iterator_begin();
1873 if (ref_paranoia < 0)
1874 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1876 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1878 iter = xcalloc(1, sizeof(*iter));
1879 ref_iterator = &iter->base;
1880 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);
1883 * We must make sure that all loose refs are read before
1884 * accessing the packed-refs file; this avoids a race
1885 * condition if loose refs are migrated to the packed-refs
1886 * file by a simultaneous process, but our in-memory view is
1887 * from before the migration. We ensure this as follows:
1888 * First, we call prime_ref_dir(), which pre-reads the loose
1889 * references for the subtree into the cache. (If they've
1890 * already been read, that's OK; we only need to guarantee
1891 * that they're read before the packed refs, not *how much*
1892 * before.) After that, we call get_packed_ref_cache(), which
1893 * internally checks whether the packed-ref cache is up to
1894 * date with what is on disk, and re-reads it if not.
1897 loose_dir = get_loose_refs(refs);
1899 if (prefix && *prefix)
1900 loose_dir = find_containing_dir(loose_dir, prefix, 0);
1903 prime_ref_dir(loose_dir);
1904 loose_iter = cache_ref_iterator_begin(loose_dir);
1906 /* There's nothing to iterate over. */
1907 loose_iter = empty_ref_iterator_begin();
1910 iter->packed_ref_cache = get_packed_ref_cache(refs);
1911 acquire_packed_ref_cache(iter->packed_ref_cache);
1912 packed_dir = get_packed_ref_dir(iter->packed_ref_cache);
1914 if (prefix && *prefix)
1915 packed_dir = find_containing_dir(packed_dir, prefix, 0);
1918 packed_iter = cache_ref_iterator_begin(packed_dir);
1920 /* There's nothing to iterate over. */
1921 packed_iter = empty_ref_iterator_begin();
1924 iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);
1925 iter->flags = flags;
1927 return ref_iterator;
1931 * Verify that the reference locked by lock has the value old_sha1.
1932 * Fail if the reference doesn't exist and mustexist is set. Return 0
1933 * on success. On error, write an error message to err, set errno, and
1934 * return a negative value.
1936 static int verify_lock(struct ref_lock *lock,
1937 const unsigned char *old_sha1, int mustexist,
1942 if (read_ref_full(lock->ref_name,
1943 mustexist ? RESOLVE_REF_READING : 0,
1944 lock->old_oid.hash, NULL)) {
1946 int save_errno = errno;
1947 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);
1951 oidclr(&lock->old_oid);
1955 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {
1956 strbuf_addf(err, "ref '%s' is at %s but expected %s",
1958 oid_to_hex(&lock->old_oid),
1959 sha1_to_hex(old_sha1));
1966 static int remove_empty_directories(struct strbuf *path)
1969 * we want to create a file but there is a directory there;
1970 * if that is an empty directory (or a directory that contains
1971 * only empty directories), remove them.
1973 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
1977 * Locks a ref returning the lock on success and NULL on failure.
1978 * On failure errno is set to something meaningful.
1980 static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,
1981 const char *refname,
1982 const unsigned char *old_sha1,
1983 const struct string_list *extras,
1984 const struct string_list *skip,
1985 unsigned int flags, int *type,
1988 struct strbuf ref_file = STRBUF_INIT;
1989 struct ref_lock *lock;
1991 int lflags = LOCK_NO_DEREF;
1992 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1993 int resolve_flags = RESOLVE_REF_NO_RECURSE;
1994 int attempts_remaining = 3;
1997 assert_main_repository(&refs->base, "lock_ref_sha1_basic");
2000 lock = xcalloc(1, sizeof(struct ref_lock));
2003 resolve_flags |= RESOLVE_REF_READING;
2004 if (flags & REF_DELETING)
2005 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
2007 strbuf_git_path(&ref_file, "%s", refname);
2008 resolved = !!resolve_ref_unsafe(refname, resolve_flags,
2009 lock->old_oid.hash, type);
2010 if (!resolved && errno == EISDIR) {
2012 * we are trying to lock foo but we used to
2013 * have foo/bar which now does not exist;
2014 * it is normal for the empty directory 'foo'
2017 if (remove_empty_directories(&ref_file)) {
2019 if (!verify_refname_available_dir(
2020 refname, extras, skip,
2021 get_loose_refs(refs), err))
2022 strbuf_addf(err, "there are still refs under '%s'",
2026 resolved = !!resolve_ref_unsafe(refname, resolve_flags,
2027 lock->old_oid.hash, type);
2031 if (last_errno != ENOTDIR ||
2032 !verify_refname_available_dir(
2033 refname, extras, skip,
2034 get_loose_refs(refs), err))
2035 strbuf_addf(err, "unable to resolve reference '%s': %s",
2036 refname, strerror(last_errno));
2042 * If the ref did not exist and we are creating it, make sure
2043 * there is no existing packed ref whose name begins with our
2044 * refname, nor a packed ref whose name is a proper prefix of
2047 if (is_null_oid(&lock->old_oid) &&
2048 verify_refname_available_dir(refname, extras, skip,
2049 get_packed_refs(refs),
2051 last_errno = ENOTDIR;
2055 lock->lk = xcalloc(1, sizeof(struct lock_file));
2057 lock->ref_name = xstrdup(refname);
2060 switch (safe_create_leading_directories_const(ref_file.buf)) {
2062 break; /* success */
2064 if (--attempts_remaining > 0)
2069 strbuf_addf(err, "unable to create directory for '%s'",
2074 if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) {
2076 if (errno == ENOENT && --attempts_remaining > 0)
2078 * Maybe somebody just deleted one of the
2079 * directories leading to ref_file. Try
2084 unable_to_lock_message(ref_file.buf, errno, err);
2088 if (verify_lock(lock, old_sha1, mustexist, err)) {
2099 strbuf_release(&ref_file);
2105 * Write an entry to the packed-refs file for the specified refname.
2106 * If peeled is non-NULL, write it as the entry's peeled value.
2108 static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,
2109 unsigned char *peeled)
2111 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);
2113 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));
2117 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2119 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2121 enum peel_status peel_status = peel_entry(entry, 0);
2123 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2124 error("internal error: %s is not a valid packed reference!",
2126 write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,
2127 peel_status == PEEL_PEELED ?
2128 entry->u.value.peeled.hash : NULL);
2133 * Lock the packed-refs file for writing. Flags is passed to
2134 * hold_lock_file_for_update(). Return 0 on success. On errors, set
2135 * errno appropriately and return a nonzero value.
2137 static int lock_packed_refs(struct files_ref_store *refs, int flags)
2139 static int timeout_configured = 0;
2140 static int timeout_value = 1000;
2141 struct packed_ref_cache *packed_ref_cache;
2143 assert_main_repository(&refs->base, "lock_packed_refs");
2145 if (!timeout_configured) {
2146 git_config_get_int("core.packedrefstimeout", &timeout_value);
2147 timeout_configured = 1;
2150 if (hold_lock_file_for_update_timeout(
2151 &packlock, git_path("packed-refs"),
2152 flags, timeout_value) < 0)
2155 * Get the current packed-refs while holding the lock. If the
2156 * packed-refs file has been modified since we last read it,
2157 * this will automatically invalidate the cache and re-read
2158 * the packed-refs file.
2160 packed_ref_cache = get_packed_ref_cache(refs);
2161 packed_ref_cache->lock = &packlock;
2162 /* Increment the reference count to prevent it from being freed: */
2163 acquire_packed_ref_cache(packed_ref_cache);
2168 * Write the current version of the packed refs cache from memory to
2169 * disk. The packed-refs file must already be locked for writing (see
2170 * lock_packed_refs()). Return zero on success. On errors, set errno
2171 * and return a nonzero value
2173 static int commit_packed_refs(struct files_ref_store *refs)
2175 struct packed_ref_cache *packed_ref_cache =
2176 get_packed_ref_cache(refs);
2181 assert_main_repository(&refs->base, "commit_packed_refs");
2183 if (!packed_ref_cache->lock)
2184 die("internal error: packed-refs not locked");
2186 out = fdopen_lock_file(packed_ref_cache->lock, "w");
2188 die_errno("unable to fdopen packed-refs descriptor");
2190 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);
2191 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2192 0, write_packed_entry_fn, out);
2194 if (commit_lock_file(packed_ref_cache->lock)) {
2198 packed_ref_cache->lock = NULL;
2199 release_packed_ref_cache(packed_ref_cache);
2205 * Rollback the lockfile for the packed-refs file, and discard the
2206 * in-memory packed reference cache. (The packed-refs file will be
2207 * read anew if it is needed again after this function is called.)
2209 static void rollback_packed_refs(struct files_ref_store *refs)
2211 struct packed_ref_cache *packed_ref_cache =
2212 get_packed_ref_cache(refs);
2214 assert_main_repository(&refs->base, "rollback_packed_refs");
2216 if (!packed_ref_cache->lock)
2217 die("internal error: packed-refs not locked");
2218 rollback_lock_file(packed_ref_cache->lock);
2219 packed_ref_cache->lock = NULL;
2220 release_packed_ref_cache(packed_ref_cache);
2221 clear_packed_ref_cache(refs);
2224 struct ref_to_prune {
2225 struct ref_to_prune *next;
2226 unsigned char sha1[20];
2227 char name[FLEX_ARRAY];
2230 struct pack_refs_cb_data {
2232 struct ref_dir *packed_refs;
2233 struct ref_to_prune *ref_to_prune;
2237 * An each_ref_entry_fn that is run over loose references only. If
2238 * the loose reference can be packed, add an entry in the packed ref
2239 * cache. If the reference should be pruned, also add it to
2240 * ref_to_prune in the pack_refs_cb_data.
2242 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2244 struct pack_refs_cb_data *cb = cb_data;
2245 enum peel_status peel_status;
2246 struct ref_entry *packed_entry;
2247 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2249 /* Do not pack per-worktree refs: */
2250 if (ref_type(entry->name) != REF_TYPE_NORMAL)
2253 /* ALWAYS pack tags */
2254 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2257 /* Do not pack symbolic or broken refs: */
2258 if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))
2261 /* Add a packed ref cache entry equivalent to the loose entry. */
2262 peel_status = peel_entry(entry, 1);
2263 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2264 die("internal error peeling reference %s (%s)",
2265 entry->name, oid_to_hex(&entry->u.value.oid));
2266 packed_entry = find_ref(cb->packed_refs, entry->name);
2268 /* Overwrite existing packed entry with info from loose entry */
2269 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2270 oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);
2272 packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash,
2273 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2274 add_ref(cb->packed_refs, packed_entry);
2276 oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);
2278 /* Schedule the loose reference for pruning if requested. */
2279 if ((cb->flags & PACK_REFS_PRUNE)) {
2280 struct ref_to_prune *n;
2281 FLEX_ALLOC_STR(n, name, entry->name);
2282 hashcpy(n->sha1, entry->u.value.oid.hash);
2283 n->next = cb->ref_to_prune;
2284 cb->ref_to_prune = n;
2290 * Remove empty parents, but spare refs/ and immediate subdirs.
2291 * Note: munges *name.
2293 static void try_remove_empty_parents(char *name)
2298 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2299 while (*p && *p != '/')
2301 /* tolerate duplicate slashes; see check_refname_format() */
2305 for (q = p; *q; q++)
2308 while (q > p && *q != '/')
2310 while (q > p && *(q-1) == '/')
2315 if (rmdir(git_path("%s", name)))
2320 /* make sure nobody touched the ref, and unlink */
2321 static void prune_ref(struct ref_to_prune *r)
2323 struct ref_transaction *transaction;
2324 struct strbuf err = STRBUF_INIT;
2326 if (check_refname_format(r->name, 0))
2329 transaction = ref_transaction_begin(&err);
2331 ref_transaction_delete(transaction, r->name, r->sha1,
2332 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||
2333 ref_transaction_commit(transaction, &err)) {
2334 ref_transaction_free(transaction);
2335 error("%s", err.buf);
2336 strbuf_release(&err);
2339 ref_transaction_free(transaction);
2340 strbuf_release(&err);
2341 try_remove_empty_parents(r->name);
2344 static void prune_refs(struct ref_to_prune *r)
2352 static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
2354 struct files_ref_store *refs =
2355 files_downcast(ref_store, 0, "pack_refs");
2356 struct pack_refs_cb_data cbdata;
2358 memset(&cbdata, 0, sizeof(cbdata));
2359 cbdata.flags = flags;
2361 lock_packed_refs(refs, LOCK_DIE_ON_ERROR);
2362 cbdata.packed_refs = get_packed_refs(refs);
2364 do_for_each_entry_in_dir(get_loose_refs(refs), 0,
2365 pack_if_possible_fn, &cbdata);
2367 if (commit_packed_refs(refs))
2368 die_errno("unable to overwrite old ref-pack file");
2370 prune_refs(cbdata.ref_to_prune);
2375 * Rewrite the packed-refs file, omitting any refs listed in
2376 * 'refnames'. On error, leave packed-refs unchanged, write an error
2377 * message to 'err', and return a nonzero value.
2379 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.
2381 static int repack_without_refs(struct files_ref_store *refs,
2382 struct string_list *refnames, struct strbuf *err)
2384 struct ref_dir *packed;
2385 struct string_list_item *refname;
2386 int ret, needs_repacking = 0, removed = 0;
2388 assert_main_repository(&refs->base, "repack_without_refs");
2391 /* Look for a packed ref */
2392 for_each_string_list_item(refname, refnames) {
2393 if (get_packed_ref(refs, refname->string)) {
2394 needs_repacking = 1;
2399 /* Avoid locking if we have nothing to do */
2400 if (!needs_repacking)
2401 return 0; /* no refname exists in packed refs */
2403 if (lock_packed_refs(refs, 0)) {
2404 unable_to_lock_message(git_path("packed-refs"), errno, err);
2407 packed = get_packed_refs(refs);
2409 /* Remove refnames from the cache */
2410 for_each_string_list_item(refname, refnames)
2411 if (remove_entry(packed, refname->string) != -1)
2415 * All packed entries disappeared while we were
2416 * acquiring the lock.
2418 rollback_packed_refs(refs);
2422 /* Write what remains */
2423 ret = commit_packed_refs(refs);
2425 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",
2430 static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
2434 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2436 * loose. The loose file name is the same as the
2437 * lockfile name, minus ".lock":
2439 char *loose_filename = get_locked_file_path(lock->lk);
2440 int res = unlink_or_msg(loose_filename, err);
2441 free(loose_filename);
2448 static int files_delete_refs(struct ref_store *ref_store,
2449 struct string_list *refnames, unsigned int flags)
2451 struct files_ref_store *refs =
2452 files_downcast(ref_store, 0, "delete_refs");
2453 struct strbuf err = STRBUF_INIT;
2459 result = repack_without_refs(refs, refnames, &err);
2462 * If we failed to rewrite the packed-refs file, then
2463 * it is unsafe to try to remove loose refs, because
2464 * doing so might expose an obsolete packed value for
2465 * a reference that might even point at an object that
2466 * has been garbage collected.
2468 if (refnames->nr == 1)
2469 error(_("could not delete reference %s: %s"),
2470 refnames->items[0].string, err.buf);
2472 error(_("could not delete references: %s"), err.buf);
2477 for (i = 0; i < refnames->nr; i++) {
2478 const char *refname = refnames->items[i].string;
2480 if (delete_ref(refname, NULL, flags))
2481 result |= error(_("could not remove reference %s"), refname);
2485 strbuf_release(&err);
2490 * People using contrib's git-new-workdir have .git/logs/refs ->
2491 * /some/other/path/.git/logs/refs, and that may live on another device.
2493 * IOW, to avoid cross device rename errors, the temporary renamed log must
2494 * live into logs/refs.
2496 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2498 static int rename_tmp_log(const char *newrefname)
2500 int attempts_remaining = 4;
2501 struct strbuf path = STRBUF_INIT;
2505 strbuf_reset(&path);
2506 strbuf_git_path(&path, "logs/%s", newrefname);
2507 switch (safe_create_leading_directories_const(path.buf)) {
2509 break; /* success */
2511 if (--attempts_remaining > 0)
2515 error("unable to create directory for %s", newrefname);
2519 if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {
2520 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2522 * rename(a, b) when b is an existing
2523 * directory ought to result in ISDIR, but
2524 * Solaris 5.8 gives ENOTDIR. Sheesh.
2526 if (remove_empty_directories(&path)) {
2527 error("Directory not empty: logs/%s", newrefname);
2531 } else if (errno == ENOENT && --attempts_remaining > 0) {
2533 * Maybe another process just deleted one of
2534 * the directories in the path to newrefname.
2535 * Try again from the beginning.
2539 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2540 newrefname, strerror(errno));
2546 strbuf_release(&path);
2550 static int files_verify_refname_available(struct ref_store *ref_store,
2551 const char *newname,
2552 const struct string_list *extras,
2553 const struct string_list *skip,
2556 struct files_ref_store *refs =
2557 files_downcast(ref_store, 1, "verify_refname_available");
2558 struct ref_dir *packed_refs = get_packed_refs(refs);
2559 struct ref_dir *loose_refs = get_loose_refs(refs);
2561 if (verify_refname_available_dir(newname, extras, skip,
2562 packed_refs, err) ||
2563 verify_refname_available_dir(newname, extras, skip,
2570 static int write_ref_to_lockfile(struct ref_lock *lock,
2571 const unsigned char *sha1, struct strbuf *err);
2572 static int commit_ref_update(struct files_ref_store *refs,
2573 struct ref_lock *lock,
2574 const unsigned char *sha1, const char *logmsg,
2575 struct strbuf *err);
2577 static int files_rename_ref(struct ref_store *ref_store,
2578 const char *oldrefname, const char *newrefname,
2581 struct files_ref_store *refs =
2582 files_downcast(ref_store, 0, "rename_ref");
2583 unsigned char sha1[20], orig_sha1[20];
2584 int flag = 0, logmoved = 0;
2585 struct ref_lock *lock;
2586 struct stat loginfo;
2587 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2588 struct strbuf err = STRBUF_INIT;
2590 if (log && S_ISLNK(loginfo.st_mode))
2591 return error("reflog for %s is a symlink", oldrefname);
2593 if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
2595 return error("refname %s not found", oldrefname);
2597 if (flag & REF_ISSYMREF)
2598 return error("refname %s is a symbolic ref, renaming it is not supported",
2600 if (!rename_ref_available(oldrefname, newrefname))
2603 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2604 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2605 oldrefname, strerror(errno));
2607 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2608 error("unable to delete old %s", oldrefname);
2613 * Since we are doing a shallow lookup, sha1 is not the
2614 * correct value to pass to delete_ref as old_sha1. But that
2615 * doesn't matter, because an old_sha1 check wouldn't add to
2616 * the safety anyway; we want to delete the reference whatever
2617 * its current value.
2619 if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
2621 delete_ref(newrefname, NULL, REF_NODEREF)) {
2622 if (errno==EISDIR) {
2623 struct strbuf path = STRBUF_INIT;
2626 strbuf_git_path(&path, "%s", newrefname);
2627 result = remove_empty_directories(&path);
2628 strbuf_release(&path);
2631 error("Directory not empty: %s", newrefname);
2635 error("unable to delete existing %s", newrefname);
2640 if (log && rename_tmp_log(newrefname))
2645 lock = lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,
2646 REF_NODEREF, NULL, &err);
2648 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
2649 strbuf_release(&err);
2652 hashcpy(lock->old_oid.hash, orig_sha1);
2654 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
2655 commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {
2656 error("unable to write current sha1 into %s: %s", newrefname, err.buf);
2657 strbuf_release(&err);
2664 lock = lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,
2665 REF_NODEREF, NULL, &err);
2667 error("unable to lock %s for rollback: %s", oldrefname, err.buf);
2668 strbuf_release(&err);
2672 flag = log_all_ref_updates;
2673 log_all_ref_updates = 0;
2674 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
2675 commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {
2676 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
2677 strbuf_release(&err);
2679 log_all_ref_updates = flag;
2682 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2683 error("unable to restore logfile %s from %s: %s",
2684 oldrefname, newrefname, strerror(errno));
2685 if (!logmoved && log &&
2686 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2687 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2688 oldrefname, strerror(errno));
2693 static int close_ref(struct ref_lock *lock)
2695 if (close_lock_file(lock->lk))
2700 static int commit_ref(struct ref_lock *lock)
2702 char *path = get_locked_file_path(lock->lk);
2705 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {
2707 * There is a directory at the path we want to rename
2708 * the lockfile to. Hopefully it is empty; try to
2711 size_t len = strlen(path);
2712 struct strbuf sb_path = STRBUF_INIT;
2714 strbuf_attach(&sb_path, path, len, len);
2717 * If this fails, commit_lock_file() will also fail
2718 * and will report the problem.
2720 remove_empty_directories(&sb_path);
2721 strbuf_release(&sb_path);
2726 if (commit_lock_file(lock->lk))
2732 * Create a reflog for a ref. If force_create = 0, the reflog will
2733 * only be created for certain refs (those for which
2734 * should_autocreate_reflog returns non-zero. Otherwise, create it
2735 * regardless of the ref name. Fill in *err and return -1 on failure.
2737 static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create)
2739 int logfd, oflags = O_APPEND | O_WRONLY;
2741 strbuf_git_path(logfile, "logs/%s", refname);
2742 if (force_create || should_autocreate_reflog(refname)) {
2743 if (safe_create_leading_directories(logfile->buf) < 0) {
2744 strbuf_addf(err, "unable to create directory for '%s': "
2745 "%s", logfile->buf, strerror(errno));
2751 logfd = open(logfile->buf, oflags, 0666);
2753 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))
2756 if (errno == EISDIR) {
2757 if (remove_empty_directories(logfile)) {
2758 strbuf_addf(err, "there are still logs under "
2759 "'%s'", logfile->buf);
2762 logfd = open(logfile->buf, oflags, 0666);
2766 strbuf_addf(err, "unable to append to '%s': %s",
2767 logfile->buf, strerror(errno));
2772 adjust_shared_perm(logfile->buf);
2778 static int files_create_reflog(struct ref_store *ref_store,
2779 const char *refname, int force_create,
2783 struct strbuf sb = STRBUF_INIT;
2785 /* Check validity (but we don't need the result): */
2786 files_downcast(ref_store, 0, "create_reflog");
2788 ret = log_ref_setup(refname, &sb, err, force_create);
2789 strbuf_release(&sb);
2793 static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
2794 const unsigned char *new_sha1,
2795 const char *committer, const char *msg)
2797 int msglen, written;
2798 unsigned maxlen, len;
2801 msglen = msg ? strlen(msg) : 0;
2802 maxlen = strlen(committer) + msglen + 100;
2803 logrec = xmalloc(maxlen);
2804 len = xsnprintf(logrec, maxlen, "%s %s %s\n",
2805 sha1_to_hex(old_sha1),
2806 sha1_to_hex(new_sha1),
2809 len += copy_reflog_msg(logrec + len - 1, msg) - 1;
2811 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;
2819 static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,
2820 const unsigned char *new_sha1, const char *msg,
2821 struct strbuf *logfile, int flags,
2824 int logfd, result, oflags = O_APPEND | O_WRONLY;
2826 if (log_all_ref_updates < 0)
2827 log_all_ref_updates = !is_bare_repository();
2829 result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);
2834 logfd = open(logfile->buf, oflags);
2837 result = log_ref_write_fd(logfd, old_sha1, new_sha1,
2838 git_committer_info(0), msg);
2840 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,
2846 strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,
2853 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2854 const unsigned char *new_sha1, const char *msg,
2855 int flags, struct strbuf *err)
2857 return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags,
2861 int files_log_ref_write(const char *refname, const unsigned char *old_sha1,
2862 const unsigned char *new_sha1, const char *msg,
2863 int flags, struct strbuf *err)
2865 struct strbuf sb = STRBUF_INIT;
2866 int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,
2868 strbuf_release(&sb);
2873 * Write sha1 into the open lockfile, then close the lockfile. On
2874 * errors, rollback the lockfile, fill in *err and
2877 static int write_ref_to_lockfile(struct ref_lock *lock,
2878 const unsigned char *sha1, struct strbuf *err)
2880 static char term = '\n';
2884 o = parse_object(sha1);
2887 "trying to write ref '%s' with nonexistent object %s",
2888 lock->ref_name, sha1_to_hex(sha1));
2892 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2894 "trying to write non-commit object %s to branch '%s'",
2895 sha1_to_hex(sha1), lock->ref_name);
2899 fd = get_lock_file_fd(lock->lk);
2900 if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 ||
2901 write_in_full(fd, &term, 1) != 1 ||
2902 close_ref(lock) < 0) {
2904 "couldn't write '%s'", get_lock_file_path(lock->lk));
2912 * Commit a change to a loose reference that has already been written
2913 * to the loose reference lockfile. Also update the reflogs if
2914 * necessary, using the specified lockmsg (which can be NULL).
2916 static int commit_ref_update(struct files_ref_store *refs,
2917 struct ref_lock *lock,
2918 const unsigned char *sha1, const char *logmsg,
2921 assert_main_repository(&refs->base, "commit_ref_update");
2923 clear_loose_ref_cache(refs);
2924 if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, 0, err)) {
2925 char *old_msg = strbuf_detach(err, NULL);
2926 strbuf_addf(err, "cannot update the ref '%s': %s",
2927 lock->ref_name, old_msg);
2933 if (strcmp(lock->ref_name, "HEAD") != 0) {
2935 * Special hack: If a branch is updated directly and HEAD
2936 * points to it (may happen on the remote side of a push
2937 * for example) then logically the HEAD reflog should be
2939 * A generic solution implies reverse symref information,
2940 * but finding all symrefs pointing to the given branch
2941 * would be rather costly for this rare event (the direct
2942 * update of a branch) to be worth it. So let's cheat and
2943 * check with HEAD only which should cover 99% of all usage
2944 * scenarios (even 100% of the default ones).
2946 unsigned char head_sha1[20];
2948 const char *head_ref;
2950 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
2951 head_sha1, &head_flag);
2952 if (head_ref && (head_flag & REF_ISSYMREF) &&
2953 !strcmp(head_ref, lock->ref_name)) {
2954 struct strbuf log_err = STRBUF_INIT;
2955 if (log_ref_write("HEAD", lock->old_oid.hash, sha1,
2956 logmsg, 0, &log_err)) {
2957 error("%s", log_err.buf);
2958 strbuf_release(&log_err);
2963 if (commit_ref(lock)) {
2964 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
2973 static int create_ref_symlink(struct ref_lock *lock, const char *target)
2976 #ifndef NO_SYMLINK_HEAD
2977 char *ref_path = get_locked_file_path(lock->lk);
2979 ret = symlink(target, ref_path);
2983 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2988 static void update_symref_reflog(struct ref_lock *lock, const char *refname,
2989 const char *target, const char *logmsg)
2991 struct strbuf err = STRBUF_INIT;
2992 unsigned char new_sha1[20];
2993 if (logmsg && !read_ref(target, new_sha1) &&
2994 log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) {
2995 error("%s", err.buf);
2996 strbuf_release(&err);
3000 static int create_symref_locked(struct ref_lock *lock, const char *refname,
3001 const char *target, const char *logmsg)
3003 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {
3004 update_symref_reflog(lock, refname, target, logmsg);
3008 if (!fdopen_lock_file(lock->lk, "w"))
3009 return error("unable to fdopen %s: %s",
3010 lock->lk->tempfile.filename.buf, strerror(errno));
3012 update_symref_reflog(lock, refname, target, logmsg);
3014 /* no error check; commit_ref will check ferror */
3015 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);
3016 if (commit_ref(lock) < 0)
3017 return error("unable to write symref for %s: %s", refname,
3022 static int files_create_symref(struct ref_store *ref_store,
3023 const char *refname, const char *target,
3026 struct files_ref_store *refs =
3027 files_downcast(ref_store, 0, "create_symref");
3028 struct strbuf err = STRBUF_INIT;
3029 struct ref_lock *lock;
3032 lock = lock_ref_sha1_basic(refs, refname, NULL,
3033 NULL, NULL, REF_NODEREF, NULL,
3036 error("%s", err.buf);
3037 strbuf_release(&err);
3041 ret = create_symref_locked(lock, refname, target, logmsg);
3046 int set_worktree_head_symref(const char *gitdir, const char *target)
3048 static struct lock_file head_lock;
3049 struct ref_lock *lock;
3050 struct strbuf head_path = STRBUF_INIT;
3051 const char *head_rel;
3054 strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir));
3055 if (hold_lock_file_for_update(&head_lock, head_path.buf,
3056 LOCK_NO_DEREF) < 0) {
3057 struct strbuf err = STRBUF_INIT;
3058 unable_to_lock_message(head_path.buf, errno, &err);
3059 error("%s", err.buf);
3060 strbuf_release(&err);
3061 strbuf_release(&head_path);
3065 /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for
3067 head_rel = remove_leading_path(head_path.buf,
3068 absolute_path(get_git_common_dir()));
3069 /* to make use of create_symref_locked(), initialize ref_lock */
3070 lock = xcalloc(1, sizeof(struct ref_lock));
3071 lock->lk = &head_lock;
3072 lock->ref_name = xstrdup(head_rel);
3074 ret = create_symref_locked(lock, head_rel, target, NULL);
3076 unlock_ref(lock); /* will free lock */
3077 strbuf_release(&head_path);
3081 static int files_reflog_exists(struct ref_store *ref_store,
3082 const char *refname)
3086 /* Check validity (but we don't need the result): */
3087 files_downcast(ref_store, 0, "reflog_exists");
3089 return !lstat(git_path("logs/%s", refname), &st) &&
3090 S_ISREG(st.st_mode);
3093 static int files_delete_reflog(struct ref_store *ref_store,
3094 const char *refname)
3096 /* Check validity (but we don't need the result): */
3097 files_downcast(ref_store, 0, "delete_reflog");
3099 return remove_path(git_path("logs/%s", refname));
3102 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3104 unsigned char osha1[20], nsha1[20];
3105 char *email_end, *message;
3106 unsigned long timestamp;
3109 /* old SP new SP name <email> SP time TAB msg LF */
3110 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3111 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3112 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3113 !(email_end = strchr(sb->buf + 82, '>')) ||
3114 email_end[1] != ' ' ||
3115 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3116 !message || message[0] != ' ' ||
3117 (message[1] != '+' && message[1] != '-') ||
3118 !isdigit(message[2]) || !isdigit(message[3]) ||
3119 !isdigit(message[4]) || !isdigit(message[5]))
3120 return 0; /* corrupt? */
3121 email_end[1] = '\0';
3122 tz = strtol(message + 1, NULL, 10);
3123 if (message[6] != '\t')
3127 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3130 static char *find_beginning_of_line(char *bob, char *scan)
3132 while (bob < scan && *(--scan) != '\n')
3133 ; /* keep scanning backwards */
3135 * Return either beginning of the buffer, or LF at the end of
3136 * the previous line.
3141 static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,
3142 const char *refname,
3143 each_reflog_ent_fn fn,
3146 struct strbuf sb = STRBUF_INIT;
3149 int ret = 0, at_tail = 1;
3151 /* Check validity (but we don't need the result): */
3152 files_downcast(ref_store, 0, "for_each_reflog_ent_reverse");
3154 logfp = fopen(git_path("logs/%s", refname), "r");
3158 /* Jump to the end */
3159 if (fseek(logfp, 0, SEEK_END) < 0)
3160 return error("cannot seek back reflog for %s: %s",
3161 refname, strerror(errno));
3163 while (!ret && 0 < pos) {
3169 /* Fill next block from the end */
3170 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3171 if (fseek(logfp, pos - cnt, SEEK_SET))
3172 return error("cannot seek back reflog for %s: %s",
3173 refname, strerror(errno));
3174 nread = fread(buf, cnt, 1, logfp);
3176 return error("cannot read %d bytes from reflog for %s: %s",
3177 cnt, refname, strerror(errno));
3180 scanp = endp = buf + cnt;
3181 if (at_tail && scanp[-1] == '\n')
3182 /* Looking at the final LF at the end of the file */
3186 while (buf < scanp) {
3188 * terminating LF of the previous line, or the beginning
3193 bp = find_beginning_of_line(buf, scanp);
3197 * The newline is the end of the previous line,
3198 * so we know we have complete line starting
3199 * at (bp + 1). Prefix it onto any prior data
3200 * we collected for the line and process it.
3202 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3205 ret = show_one_reflog_ent(&sb, fn, cb_data);
3211 * We are at the start of the buffer, and the
3212 * start of the file; there is no previous
3213 * line, and we have everything for this one.
3214 * Process it, and we can end the loop.
3216 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3217 ret = show_one_reflog_ent(&sb, fn, cb_data);
3224 * We are at the start of the buffer, and there
3225 * is more file to read backwards. Which means
3226 * we are in the middle of a line. Note that we
3227 * may get here even if *bp was a newline; that
3228 * just means we are at the exact end of the
3229 * previous line, rather than some spot in the
3232 * Save away what we have to be combined with
3233 * the data from the next read.
3235 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3242 die("BUG: reverse reflog parser had leftover data");
3245 strbuf_release(&sb);
3249 static int files_for_each_reflog_ent(struct ref_store *ref_store,
3250 const char *refname,
3251 each_reflog_ent_fn fn, void *cb_data)
3254 struct strbuf sb = STRBUF_INIT;
3257 /* Check validity (but we don't need the result): */
3258 files_downcast(ref_store, 0, "for_each_reflog_ent");
3260 logfp = fopen(git_path("logs/%s", refname), "r");
3264 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3265 ret = show_one_reflog_ent(&sb, fn, cb_data);
3267 strbuf_release(&sb);
3271 struct files_reflog_iterator {
3272 struct ref_iterator base;
3274 struct dir_iterator *dir_iterator;
3275 struct object_id oid;
3278 static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
3280 struct files_reflog_iterator *iter =
3281 (struct files_reflog_iterator *)ref_iterator;
3282 struct dir_iterator *diter = iter->dir_iterator;
3285 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
3288 if (!S_ISREG(diter->st.st_mode))
3290 if (diter->basename[0] == '.')
3292 if (ends_with(diter->basename, ".lock"))
3295 if (read_ref_full(diter->relative_path, 0,
3296 iter->oid.hash, &flags)) {
3297 error("bad ref for %s", diter->path.buf);
3301 iter->base.refname = diter->relative_path;
3302 iter->base.oid = &iter->oid;
3303 iter->base.flags = flags;
3307 iter->dir_iterator = NULL;
3308 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)
3313 static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,
3314 struct object_id *peeled)
3316 die("BUG: ref_iterator_peel() called for reflog_iterator");
3319 static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)
3321 struct files_reflog_iterator *iter =
3322 (struct files_reflog_iterator *)ref_iterator;
3325 if (iter->dir_iterator)
3326 ok = dir_iterator_abort(iter->dir_iterator);
3328 base_ref_iterator_free(ref_iterator);
3332 static struct ref_iterator_vtable files_reflog_iterator_vtable = {
3333 files_reflog_iterator_advance,
3334 files_reflog_iterator_peel,
3335 files_reflog_iterator_abort
3338 static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)
3340 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));
3341 struct ref_iterator *ref_iterator = &iter->base;
3343 /* Check validity (but we don't need the result): */
3344 files_downcast(ref_store, 0, "reflog_iterator_begin");
3346 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);
3347 iter->dir_iterator = dir_iterator_begin(git_path("logs"));
3348 return ref_iterator;
3351 static int ref_update_reject_duplicates(struct string_list *refnames,
3354 int i, n = refnames->nr;
3358 for (i = 1; i < n; i++)
3359 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {
3361 "multiple updates for ref '%s' not allowed.",
3362 refnames->items[i].string);
3369 * If update is a direct update of head_ref (the reference pointed to
3370 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.
3372 static int split_head_update(struct ref_update *update,
3373 struct ref_transaction *transaction,
3374 const char *head_ref,
3375 struct string_list *affected_refnames,
3378 struct string_list_item *item;
3379 struct ref_update *new_update;
3381 if ((update->flags & REF_LOG_ONLY) ||
3382 (update->flags & REF_ISPRUNING) ||
3383 (update->flags & REF_UPDATE_VIA_HEAD))
3386 if (strcmp(update->refname, head_ref))
3390 * First make sure that HEAD is not already in the
3391 * transaction. This insertion is O(N) in the transaction
3392 * size, but it happens at most once per transaction.
3394 item = string_list_insert(affected_refnames, "HEAD");
3396 /* An entry already existed */
3398 "multiple updates for 'HEAD' (including one "
3399 "via its referent '%s') are not allowed",
3401 return TRANSACTION_NAME_CONFLICT;
3404 new_update = ref_transaction_add_update(
3405 transaction, "HEAD",
3406 update->flags | REF_LOG_ONLY | REF_NODEREF,
3407 update->new_sha1, update->old_sha1,
3410 item->util = new_update;
3416 * update is for a symref that points at referent and doesn't have
3417 * REF_NODEREF set. Split it into two updates:
3418 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set
3419 * - A new, separate update for the referent reference
3420 * Note that the new update will itself be subject to splitting when
3421 * the iteration gets to it.
3423 static int split_symref_update(struct files_ref_store *refs,
3424 struct ref_update *update,
3425 const char *referent,
3426 struct ref_transaction *transaction,
3427 struct string_list *affected_refnames,
3430 struct string_list_item *item;
3431 struct ref_update *new_update;
3432 unsigned int new_flags;
3435 * First make sure that referent is not already in the
3436 * transaction. This insertion is O(N) in the transaction
3437 * size, but it happens at most once per symref in a
3440 item = string_list_insert(affected_refnames, referent);
3442 /* An entry already existed */
3444 "multiple updates for '%s' (including one "
3445 "via symref '%s') are not allowed",
3446 referent, update->refname);
3447 return TRANSACTION_NAME_CONFLICT;
3450 new_flags = update->flags;
3451 if (!strcmp(update->refname, "HEAD")) {
3453 * Record that the new update came via HEAD, so that
3454 * when we process it, split_head_update() doesn't try
3455 * to add another reflog update for HEAD. Note that
3456 * this bit will be propagated if the new_update
3457 * itself needs to be split.
3459 new_flags |= REF_UPDATE_VIA_HEAD;
3462 new_update = ref_transaction_add_update(
3463 transaction, referent, new_flags,
3464 update->new_sha1, update->old_sha1,
3467 new_update->parent_update = update;
3470 * Change the symbolic ref update to log only. Also, it
3471 * doesn't need to check its old SHA-1 value, as that will be
3472 * done when new_update is processed.
3474 update->flags |= REF_LOG_ONLY | REF_NODEREF;
3475 update->flags &= ~REF_HAVE_OLD;
3477 item->util = new_update;
3483 * Return the refname under which update was originally requested.
3485 static const char *original_update_refname(struct ref_update *update)
3487 while (update->parent_update)
3488 update = update->parent_update;
3490 return update->refname;
3494 * Check whether the REF_HAVE_OLD and old_oid values stored in update
3495 * are consistent with oid, which is the reference's current value. If
3496 * everything is OK, return 0; otherwise, write an error message to
3497 * err and return -1.
3499 static int check_old_oid(struct ref_update *update, struct object_id *oid,
3502 if (!(update->flags & REF_HAVE_OLD) ||
3503 !hashcmp(oid->hash, update->old_sha1))
3506 if (is_null_sha1(update->old_sha1))
3507 strbuf_addf(err, "cannot lock ref '%s': "
3508 "reference already exists",
3509 original_update_refname(update));
3510 else if (is_null_oid(oid))
3511 strbuf_addf(err, "cannot lock ref '%s': "
3512 "reference is missing but expected %s",
3513 original_update_refname(update),
3514 sha1_to_hex(update->old_sha1));
3516 strbuf_addf(err, "cannot lock ref '%s': "
3517 "is at %s but expected %s",
3518 original_update_refname(update),
3520 sha1_to_hex(update->old_sha1));
3526 * Prepare for carrying out update:
3527 * - Lock the reference referred to by update.
3528 * - Read the reference under lock.
3529 * - Check that its old SHA-1 value (if specified) is correct, and in
3530 * any case record it in update->lock->old_oid for later use when
3531 * writing the reflog.
3532 * - If it is a symref update without REF_NODEREF, split it up into a
3533 * REF_LOG_ONLY update of the symref and add a separate update for
3534 * the referent to transaction.
3535 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY
3538 static int lock_ref_for_update(struct files_ref_store *refs,
3539 struct ref_update *update,
3540 struct ref_transaction *transaction,
3541 const char *head_ref,
3542 struct string_list *affected_refnames,
3545 struct strbuf referent = STRBUF_INIT;
3546 int mustexist = (update->flags & REF_HAVE_OLD) &&
3547 !is_null_sha1(update->old_sha1);
3549 struct ref_lock *lock;
3551 assert_main_repository(&refs->base, "lock_ref_for_update");
3553 if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))
3554 update->flags |= REF_DELETING;
3557 ret = split_head_update(update, transaction, head_ref,
3558 affected_refnames, err);
3563 ret = lock_raw_ref(refs, update->refname, mustexist,
3564 affected_refnames, NULL,
3566 &update->type, err);
3570 reason = strbuf_detach(err, NULL);
3571 strbuf_addf(err, "cannot lock ref '%s': %s",
3572 original_update_refname(update), reason);
3577 update->backend_data = lock;
3579 if (update->type & REF_ISSYMREF) {
3580 if (update->flags & REF_NODEREF) {
3582 * We won't be reading the referent as part of
3583 * the transaction, so we have to read it here
3584 * to record and possibly check old_sha1:
3586 if (read_ref_full(referent.buf, 0,
3587 lock->old_oid.hash, NULL)) {
3588 if (update->flags & REF_HAVE_OLD) {
3589 strbuf_addf(err, "cannot lock ref '%s': "
3590 "error reading reference",
3591 original_update_refname(update));
3594 } else if (check_old_oid(update, &lock->old_oid, err)) {
3595 return TRANSACTION_GENERIC_ERROR;
3599 * Create a new update for the reference this
3600 * symref is pointing at. Also, we will record
3601 * and verify old_sha1 for this update as part
3602 * of processing the split-off update, so we
3603 * don't have to do it here.
3605 ret = split_symref_update(refs, update,
3606 referent.buf, transaction,
3607 affected_refnames, err);
3612 struct ref_update *parent_update;
3614 if (check_old_oid(update, &lock->old_oid, err))
3615 return TRANSACTION_GENERIC_ERROR;
3618 * If this update is happening indirectly because of a
3619 * symref update, record the old SHA-1 in the parent
3622 for (parent_update = update->parent_update;
3624 parent_update = parent_update->parent_update) {
3625 struct ref_lock *parent_lock = parent_update->backend_data;
3626 oidcpy(&parent_lock->old_oid, &lock->old_oid);
3630 if ((update->flags & REF_HAVE_NEW) &&
3631 !(update->flags & REF_DELETING) &&
3632 !(update->flags & REF_LOG_ONLY)) {
3633 if (!(update->type & REF_ISSYMREF) &&
3634 !hashcmp(lock->old_oid.hash, update->new_sha1)) {
3636 * The reference already has the desired
3637 * value, so we don't need to write it.
3639 } else if (write_ref_to_lockfile(lock, update->new_sha1,
3641 char *write_err = strbuf_detach(err, NULL);
3644 * The lock was freed upon failure of
3645 * write_ref_to_lockfile():
3647 update->backend_data = NULL;
3649 "cannot update ref '%s': %s",
3650 update->refname, write_err);
3652 return TRANSACTION_GENERIC_ERROR;
3654 update->flags |= REF_NEEDS_COMMIT;
3657 if (!(update->flags & REF_NEEDS_COMMIT)) {
3659 * We didn't call write_ref_to_lockfile(), so
3660 * the lockfile is still open. Close it to
3661 * free up the file descriptor:
3663 if (close_ref(lock)) {
3664 strbuf_addf(err, "couldn't close '%s.lock'",
3666 return TRANSACTION_GENERIC_ERROR;
3672 static int files_transaction_commit(struct ref_store *ref_store,
3673 struct ref_transaction *transaction,
3676 struct files_ref_store *refs =
3677 files_downcast(ref_store, 0, "ref_transaction_commit");
3679 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;
3680 struct string_list_item *ref_to_delete;
3681 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
3682 char *head_ref = NULL;
3684 struct object_id head_oid;
3688 if (transaction->state != REF_TRANSACTION_OPEN)
3689 die("BUG: commit called for transaction that is not open");
3691 if (!transaction->nr) {
3692 transaction->state = REF_TRANSACTION_CLOSED;
3697 * Fail if a refname appears more than once in the
3698 * transaction. (If we end up splitting up any updates using
3699 * split_symref_update() or split_head_update(), those
3700 * functions will check that the new updates don't have the
3701 * same refname as any existing ones.)
3703 for (i = 0; i < transaction->nr; i++) {
3704 struct ref_update *update = transaction->updates[i];
3705 struct string_list_item *item =
3706 string_list_append(&affected_refnames, update->refname);
3709 * We store a pointer to update in item->util, but at
3710 * the moment we never use the value of this field
3711 * except to check whether it is non-NULL.
3713 item->util = update;
3715 string_list_sort(&affected_refnames);
3716 if (ref_update_reject_duplicates(&affected_refnames, err)) {
3717 ret = TRANSACTION_GENERIC_ERROR;
3722 * Special hack: If a branch is updated directly and HEAD
3723 * points to it (may happen on the remote side of a push
3724 * for example) then logically the HEAD reflog should be
3727 * A generic solution would require reverse symref lookups,
3728 * but finding all symrefs pointing to a given branch would be
3729 * rather costly for this rare event (the direct update of a
3730 * branch) to be worth it. So let's cheat and check with HEAD
3731 * only, which should cover 99% of all usage scenarios (even
3732 * 100% of the default ones).
3734 * So if HEAD is a symbolic reference, then record the name of
3735 * the reference that it points to. If we see an update of
3736 * head_ref within the transaction, then split_head_update()
3737 * arranges for the reflog of HEAD to be updated, too.
3739 head_ref = resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,
3740 head_oid.hash, &head_type);
3742 if (head_ref && !(head_type & REF_ISSYMREF)) {
3748 * Acquire all locks, verify old values if provided, check
3749 * that new values are valid, and write new values to the
3750 * lockfiles, ready to be activated. Only keep one lockfile
3751 * open at a time to avoid running out of file descriptors.
3753 for (i = 0; i < transaction->nr; i++) {
3754 struct ref_update *update = transaction->updates[i];
3756 ret = lock_ref_for_update(refs, update, transaction,
3757 head_ref, &affected_refnames, err);
3762 /* Perform updates first so live commits remain referenced */
3763 for (i = 0; i < transaction->nr; i++) {
3764 struct ref_update *update = transaction->updates[i];
3765 struct ref_lock *lock = update->backend_data;
3767 if (update->flags & REF_NEEDS_COMMIT ||
3768 update->flags & REF_LOG_ONLY) {
3769 if (log_ref_write(lock->ref_name, lock->old_oid.hash,
3771 update->msg, update->flags, err)) {
3772 char *old_msg = strbuf_detach(err, NULL);
3774 strbuf_addf(err, "cannot update the ref '%s': %s",
3775 lock->ref_name, old_msg);
3778 update->backend_data = NULL;
3779 ret = TRANSACTION_GENERIC_ERROR;
3783 if (update->flags & REF_NEEDS_COMMIT) {
3784 clear_loose_ref_cache(refs);
3785 if (commit_ref(lock)) {
3786 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
3788 update->backend_data = NULL;
3789 ret = TRANSACTION_GENERIC_ERROR;
3794 /* Perform deletes now that updates are safely completed */
3795 for (i = 0; i < transaction->nr; i++) {
3796 struct ref_update *update = transaction->updates[i];
3797 struct ref_lock *lock = update->backend_data;
3799 if (update->flags & REF_DELETING &&
3800 !(update->flags & REF_LOG_ONLY)) {
3801 if (delete_ref_loose(lock, update->type, err)) {
3802 ret = TRANSACTION_GENERIC_ERROR;
3806 if (!(update->flags & REF_ISPRUNING))
3807 string_list_append(&refs_to_delete,
3812 if (repack_without_refs(refs, &refs_to_delete, err)) {
3813 ret = TRANSACTION_GENERIC_ERROR;
3816 for_each_string_list_item(ref_to_delete, &refs_to_delete)
3817 unlink_or_warn(git_path("logs/%s", ref_to_delete->string));
3818 clear_loose_ref_cache(refs);
3821 transaction->state = REF_TRANSACTION_CLOSED;
3823 for (i = 0; i < transaction->nr; i++)
3824 if (transaction->updates[i]->backend_data)
3825 unlock_ref(transaction->updates[i]->backend_data);
3826 string_list_clear(&refs_to_delete, 0);
3828 string_list_clear(&affected_refnames, 0);
3833 static int ref_present(const char *refname,
3834 const struct object_id *oid, int flags, void *cb_data)
3836 struct string_list *affected_refnames = cb_data;
3838 return string_list_has_string(affected_refnames, refname);
3841 static int files_initial_transaction_commit(struct ref_store *ref_store,
3842 struct ref_transaction *transaction,
3845 struct files_ref_store *refs =
3846 files_downcast(ref_store, 0, "initial_ref_transaction_commit");
3848 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
3852 if (transaction->state != REF_TRANSACTION_OPEN)
3853 die("BUG: commit called for transaction that is not open");
3855 /* Fail if a refname appears more than once in the transaction: */
3856 for (i = 0; i < transaction->nr; i++)
3857 string_list_append(&affected_refnames,
3858 transaction->updates[i]->refname);
3859 string_list_sort(&affected_refnames);
3860 if (ref_update_reject_duplicates(&affected_refnames, err)) {
3861 ret = TRANSACTION_GENERIC_ERROR;
3866 * It's really undefined to call this function in an active
3867 * repository or when there are existing references: we are
3868 * only locking and changing packed-refs, so (1) any
3869 * simultaneous processes might try to change a reference at
3870 * the same time we do, and (2) any existing loose versions of
3871 * the references that we are setting would have precedence
3872 * over our values. But some remote helpers create the remote
3873 * "HEAD" and "master" branches before calling this function,
3874 * so here we really only check that none of the references
3875 * that we are creating already exists.
3877 if (for_each_rawref(ref_present, &affected_refnames))
3878 die("BUG: initial ref transaction called with existing refs");
3880 for (i = 0; i < transaction->nr; i++) {
3881 struct ref_update *update = transaction->updates[i];
3883 if ((update->flags & REF_HAVE_OLD) &&
3884 !is_null_sha1(update->old_sha1))
3885 die("BUG: initial ref transaction with old_sha1 set");
3886 if (verify_refname_available(update->refname,
3887 &affected_refnames, NULL,
3889 ret = TRANSACTION_NAME_CONFLICT;
3894 if (lock_packed_refs(refs, 0)) {
3895 strbuf_addf(err, "unable to lock packed-refs file: %s",
3897 ret = TRANSACTION_GENERIC_ERROR;
3901 for (i = 0; i < transaction->nr; i++) {
3902 struct ref_update *update = transaction->updates[i];
3904 if ((update->flags & REF_HAVE_NEW) &&
3905 !is_null_sha1(update->new_sha1))
3906 add_packed_ref(refs, update->refname, update->new_sha1);
3909 if (commit_packed_refs(refs)) {
3910 strbuf_addf(err, "unable to commit packed-refs file: %s",
3912 ret = TRANSACTION_GENERIC_ERROR;
3917 transaction->state = REF_TRANSACTION_CLOSED;
3918 string_list_clear(&affected_refnames, 0);
3922 struct expire_reflog_cb {
3924 reflog_expiry_should_prune_fn *should_prune_fn;
3927 unsigned char last_kept_sha1[20];
3930 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
3931 const char *email, unsigned long timestamp, int tz,
3932 const char *message, void *cb_data)
3934 struct expire_reflog_cb *cb = cb_data;
3935 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
3937 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
3938 osha1 = cb->last_kept_sha1;
3940 if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,
3941 message, policy_cb)) {
3943 printf("would prune %s", message);
3944 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3945 printf("prune %s", message);
3948 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",
3949 sha1_to_hex(osha1), sha1_to_hex(nsha1),
3950 email, timestamp, tz, message);
3951 hashcpy(cb->last_kept_sha1, nsha1);
3953 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3954 printf("keep %s", message);
3959 static int files_reflog_expire(struct ref_store *ref_store,
3960 const char *refname, const unsigned char *sha1,
3962 reflog_expiry_prepare_fn prepare_fn,
3963 reflog_expiry_should_prune_fn should_prune_fn,
3964 reflog_expiry_cleanup_fn cleanup_fn,
3965 void *policy_cb_data)
3967 struct files_ref_store *refs =
3968 files_downcast(ref_store, 0, "reflog_expire");
3969 static struct lock_file reflog_lock;
3970 struct expire_reflog_cb cb;
3971 struct ref_lock *lock;
3975 struct strbuf err = STRBUF_INIT;
3977 memset(&cb, 0, sizeof(cb));
3979 cb.policy_cb = policy_cb_data;
3980 cb.should_prune_fn = should_prune_fn;
3983 * The reflog file is locked by holding the lock on the
3984 * reference itself, plus we might need to update the
3985 * reference if --updateref was specified:
3987 lock = lock_ref_sha1_basic(refs, refname, sha1,
3988 NULL, NULL, REF_NODEREF,
3991 error("cannot lock ref '%s': %s", refname, err.buf);
3992 strbuf_release(&err);
3995 if (!reflog_exists(refname)) {
4000 log_file = git_pathdup("logs/%s", refname);
4001 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
4003 * Even though holding $GIT_DIR/logs/$reflog.lock has
4004 * no locking implications, we use the lock_file
4005 * machinery here anyway because it does a lot of the
4006 * work we need, including cleaning up if the program
4007 * exits unexpectedly.
4009 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
4010 struct strbuf err = STRBUF_INIT;
4011 unable_to_lock_message(log_file, errno, &err);
4012 error("%s", err.buf);
4013 strbuf_release(&err);
4016 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
4018 error("cannot fdopen %s (%s)",
4019 get_lock_file_path(&reflog_lock), strerror(errno));
4024 (*prepare_fn)(refname, sha1, cb.policy_cb);
4025 for_each_reflog_ent(refname, expire_reflog_ent, &cb);
4026 (*cleanup_fn)(cb.policy_cb);
4028 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
4030 * It doesn't make sense to adjust a reference pointed
4031 * to by a symbolic ref based on expiring entries in
4032 * the symbolic reference's reflog. Nor can we update
4033 * a reference if there are no remaining reflog
4036 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
4037 !(type & REF_ISSYMREF) &&
4038 !is_null_sha1(cb.last_kept_sha1);
4040 if (close_lock_file(&reflog_lock)) {
4041 status |= error("couldn't write %s: %s", log_file,
4043 } else if (update &&
4044 (write_in_full(get_lock_file_fd(lock->lk),
4045 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
4046 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||
4047 close_ref(lock) < 0)) {
4048 status |= error("couldn't write %s",
4049 get_lock_file_path(lock->lk));
4050 rollback_lock_file(&reflog_lock);
4051 } else if (commit_lock_file(&reflog_lock)) {
4052 status |= error("unable to write reflog '%s' (%s)",
4053 log_file, strerror(errno));
4054 } else if (update && commit_ref(lock)) {
4055 status |= error("couldn't set %s", lock->ref_name);
4063 rollback_lock_file(&reflog_lock);
4069 static int files_init_db(struct ref_store *ref_store, struct strbuf *err)
4071 /* Check validity (but we don't need the result): */
4072 files_downcast(ref_store, 0, "init_db");
4075 * Create .git/refs/{heads,tags}
4077 safe_create_dir(git_path("refs/heads"), 1);
4078 safe_create_dir(git_path("refs/tags"), 1);
4079 if (get_shared_repository()) {
4080 adjust_shared_perm(git_path("refs/heads"));
4081 adjust_shared_perm(git_path("refs/tags"));
4086 struct ref_storage_be refs_be_files = {
4089 files_ref_store_create,
4091 files_transaction_commit,
4092 files_initial_transaction_commit,
4096 files_create_symref,
4100 files_ref_iterator_begin,
4102 files_verify_refname_available,
4104 files_reflog_iterator_begin,
4105 files_for_each_reflog_ent,
4106 files_for_each_reflog_ent_reverse,
4107 files_reflog_exists,
4108 files_create_reflog,
4109 files_delete_reflog,