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);
168 static int files_log_ref_write(const char *refname, const unsigned char *old_sha1,
169 const unsigned char *new_sha1, const char *msg,
170 int flags, struct strbuf *err);
172 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
175 assert(entry->flag & REF_DIR);
176 dir = &entry->u.subdir;
177 if (entry->flag & REF_INCOMPLETE) {
178 read_loose_refs(entry->name, dir);
181 * Manually add refs/bisect, which, being
182 * per-worktree, might not appear in the directory
183 * listing for refs/ in the main repo.
185 if (!strcmp(entry->name, "refs/")) {
186 int pos = search_ref_dir(dir, "refs/bisect/", 12);
188 struct ref_entry *child_entry;
189 child_entry = create_dir_entry(dir->ref_store,
192 add_entry_to_dir(dir, child_entry);
193 read_loose_refs("refs/bisect",
194 &child_entry->u.subdir);
197 entry->flag &= ~REF_INCOMPLETE;
202 static struct ref_entry *create_ref_entry(const char *refname,
203 const unsigned char *sha1, int flag,
206 struct ref_entry *ref;
209 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
210 die("Reference has invalid format: '%s'", refname);
211 FLEX_ALLOC_STR(ref, name, refname);
212 hashcpy(ref->u.value.oid.hash, sha1);
213 oidclr(&ref->u.value.peeled);
218 static void clear_ref_dir(struct ref_dir *dir);
220 static void free_ref_entry(struct ref_entry *entry)
222 if (entry->flag & REF_DIR) {
224 * Do not use get_ref_dir() here, as that might
225 * trigger the reading of loose refs.
227 clear_ref_dir(&entry->u.subdir);
233 * Add a ref_entry to the end of dir (unsorted). Entry is always
234 * stored directly in dir; no recursion into subdirectories is
237 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
239 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
240 dir->entries[dir->nr++] = entry;
241 /* optimize for the case that entries are added in order */
243 (dir->nr == dir->sorted + 1 &&
244 strcmp(dir->entries[dir->nr - 2]->name,
245 dir->entries[dir->nr - 1]->name) < 0))
246 dir->sorted = dir->nr;
250 * Clear and free all entries in dir, recursively.
252 static void clear_ref_dir(struct ref_dir *dir)
255 for (i = 0; i < dir->nr; i++)
256 free_ref_entry(dir->entries[i]);
258 dir->sorted = dir->nr = dir->alloc = 0;
263 * Create a struct ref_entry object for the specified dirname.
264 * dirname is the name of the directory with a trailing slash (e.g.,
265 * "refs/heads/") or "" for the top-level directory.
267 static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store,
268 const char *dirname, size_t len,
271 struct ref_entry *direntry;
272 FLEX_ALLOC_MEM(direntry, name, dirname, len);
273 direntry->u.subdir.ref_store = ref_store;
274 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
278 static int ref_entry_cmp(const void *a, const void *b)
280 struct ref_entry *one = *(struct ref_entry **)a;
281 struct ref_entry *two = *(struct ref_entry **)b;
282 return strcmp(one->name, two->name);
285 static void sort_ref_dir(struct ref_dir *dir);
287 struct string_slice {
292 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
294 const struct string_slice *key = key_;
295 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
296 int cmp = strncmp(key->str, ent->name, key->len);
299 return '\0' - (unsigned char)ent->name[key->len];
303 * Return the index of the entry with the given refname from the
304 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
305 * no such entry is found. dir must already be complete.
307 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
309 struct ref_entry **r;
310 struct string_slice key;
312 if (refname == NULL || !dir->nr)
318 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
319 ref_entry_cmp_sslice);
324 return r - dir->entries;
328 * Search for a directory entry directly within dir (without
329 * recursing). Sort dir if necessary. subdirname must be a directory
330 * name (i.e., end in '/'). If mkdir is set, then create the
331 * directory if it is missing; otherwise, return NULL if the desired
332 * directory cannot be found. dir must already be complete.
334 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
335 const char *subdirname, size_t len,
338 int entry_index = search_ref_dir(dir, subdirname, len);
339 struct ref_entry *entry;
340 if (entry_index == -1) {
344 * Since dir is complete, the absence of a subdir
345 * means that the subdir really doesn't exist;
346 * therefore, create an empty record for it but mark
347 * the record complete.
349 entry = create_dir_entry(dir->ref_store, subdirname, len, 0);
350 add_entry_to_dir(dir, entry);
352 entry = dir->entries[entry_index];
354 return get_ref_dir(entry);
358 * If refname is a reference name, find the ref_dir within the dir
359 * tree that should hold refname. If refname is a directory name
360 * (i.e., ends in '/'), then return that ref_dir itself. dir must
361 * represent the top-level directory and must already be complete.
362 * Sort ref_dirs and recurse into subdirectories as necessary. If
363 * mkdir is set, then create any missing directories; otherwise,
364 * return NULL if the desired directory cannot be found.
366 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
367 const char *refname, int mkdir)
370 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
371 size_t dirnamelen = slash - refname + 1;
372 struct ref_dir *subdir;
373 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
385 * Find the value entry with the given name in dir, sorting ref_dirs
386 * and recursing into subdirectories as necessary. If the name is not
387 * found or it corresponds to a directory entry, return NULL.
389 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
392 struct ref_entry *entry;
393 dir = find_containing_dir(dir, refname, 0);
396 entry_index = search_ref_dir(dir, refname, strlen(refname));
397 if (entry_index == -1)
399 entry = dir->entries[entry_index];
400 return (entry->flag & REF_DIR) ? NULL : entry;
404 * Remove the entry with the given name from dir, recursing into
405 * subdirectories as necessary. If refname is the name of a directory
406 * (i.e., ends with '/'), then remove the directory and its contents.
407 * If the removal was successful, return the number of entries
408 * remaining in the directory entry that contained the deleted entry.
409 * If the name was not found, return -1. Please note that this
410 * function only deletes the entry from the cache; it does not delete
411 * it from the filesystem or ensure that other cache entries (which
412 * might be symbolic references to the removed entry) are updated.
413 * Nor does it remove any containing dir entries that might be made
414 * empty by the removal. dir must represent the top-level directory
415 * and must already be complete.
417 static int remove_entry(struct ref_dir *dir, const char *refname)
419 int refname_len = strlen(refname);
421 struct ref_entry *entry;
422 int is_dir = refname[refname_len - 1] == '/';
425 * refname represents a reference directory. Remove
426 * the trailing slash; otherwise we will get the
427 * directory *representing* refname rather than the
428 * one *containing* it.
430 char *dirname = xmemdupz(refname, refname_len - 1);
431 dir = find_containing_dir(dir, dirname, 0);
434 dir = find_containing_dir(dir, refname, 0);
438 entry_index = search_ref_dir(dir, refname, refname_len);
439 if (entry_index == -1)
441 entry = dir->entries[entry_index];
443 memmove(&dir->entries[entry_index],
444 &dir->entries[entry_index + 1],
445 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
448 if (dir->sorted > entry_index)
450 free_ref_entry(entry);
455 * Add a ref_entry to the ref_dir (unsorted), recursing into
456 * subdirectories as necessary. dir must represent the top-level
457 * directory. Return 0 on success.
459 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
461 dir = find_containing_dir(dir, ref->name, 1);
464 add_entry_to_dir(dir, ref);
469 * Emit a warning and return true iff ref1 and ref2 have the same name
470 * and the same sha1. Die if they have the same name but different
473 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
475 if (strcmp(ref1->name, ref2->name))
478 /* Duplicate name; make sure that they don't conflict: */
480 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
481 /* This is impossible by construction */
482 die("Reference directory conflict: %s", ref1->name);
484 if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid))
485 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
487 warning("Duplicated ref: %s", ref1->name);
492 * Sort the entries in dir non-recursively (if they are not already
493 * sorted) and remove any duplicate entries.
495 static void sort_ref_dir(struct ref_dir *dir)
498 struct ref_entry *last = NULL;
501 * This check also prevents passing a zero-length array to qsort(),
502 * which is a problem on some platforms.
504 if (dir->sorted == dir->nr)
507 QSORT(dir->entries, dir->nr, ref_entry_cmp);
509 /* Remove any duplicates: */
510 for (i = 0, j = 0; j < dir->nr; j++) {
511 struct ref_entry *entry = dir->entries[j];
512 if (last && is_dup_ref(last, entry))
513 free_ref_entry(entry);
515 last = dir->entries[i++] = entry;
517 dir->sorted = dir->nr = i;
521 * Return true if refname, which has the specified oid and flags, can
522 * be resolved to an object in the database. If the referred-to object
523 * does not exist, emit a warning and return false.
525 static int ref_resolves_to_object(const char *refname,
526 const struct object_id *oid,
529 if (flags & REF_ISBROKEN)
531 if (!has_sha1_file(oid->hash)) {
532 error("%s does not point to a valid object!", refname);
539 * Return true if the reference described by entry can be resolved to
540 * an object in the database; otherwise, emit a warning and return
543 static int entry_resolves_to_object(struct ref_entry *entry)
545 return ref_resolves_to_object(entry->name,
546 &entry->u.value.oid, entry->flag);
549 typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
552 * Call fn for each reference in dir that has index in the range
553 * offset <= index < dir->nr. Recurse into subdirectories that are in
554 * that index range, sorting them before iterating. This function
555 * does not sort dir itself; it should be sorted beforehand. fn is
556 * called for all references, including broken ones.
558 static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
559 each_ref_entry_fn fn, void *cb_data)
562 assert(dir->sorted == dir->nr);
563 for (i = offset; i < dir->nr; i++) {
564 struct ref_entry *entry = dir->entries[i];
566 if (entry->flag & REF_DIR) {
567 struct ref_dir *subdir = get_ref_dir(entry);
568 sort_ref_dir(subdir);
569 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
571 retval = fn(entry, cb_data);
580 * Load all of the refs from the dir into our in-memory cache. The hard work
581 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
582 * through all of the sub-directories. We do not even need to care about
583 * sorting, as traversal order does not matter to us.
585 static void prime_ref_dir(struct ref_dir *dir)
588 for (i = 0; i < dir->nr; i++) {
589 struct ref_entry *entry = dir->entries[i];
590 if (entry->flag & REF_DIR)
591 prime_ref_dir(get_ref_dir(entry));
596 * A level in the reference hierarchy that is currently being iterated
599 struct cache_ref_iterator_level {
601 * The ref_dir being iterated over at this level. The ref_dir
602 * is sorted before being stored here.
607 * The index of the current entry within dir (which might
608 * itself be a directory). If index == -1, then the iteration
609 * hasn't yet begun. If index == dir->nr, then the iteration
610 * through this level is over.
616 * Represent an iteration through a ref_dir in the memory cache. The
617 * iteration recurses through subdirectories.
619 struct cache_ref_iterator {
620 struct ref_iterator base;
623 * The number of levels currently on the stack. This is always
624 * at least 1, because when it becomes zero the iteration is
625 * ended and this struct is freed.
629 /* The number of levels that have been allocated on the stack */
633 * A stack of levels. levels[0] is the uppermost level that is
634 * being iterated over in this iteration. (This is not
635 * necessary the top level in the references hierarchy. If we
636 * are iterating through a subtree, then levels[0] will hold
637 * the ref_dir for that subtree, and subsequent levels will go
640 struct cache_ref_iterator_level *levels;
643 static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator)
645 struct cache_ref_iterator *iter =
646 (struct cache_ref_iterator *)ref_iterator;
649 struct cache_ref_iterator_level *level =
650 &iter->levels[iter->levels_nr - 1];
651 struct ref_dir *dir = level->dir;
652 struct ref_entry *entry;
654 if (level->index == -1)
657 if (++level->index == level->dir->nr) {
658 /* This level is exhausted; pop up a level */
659 if (--iter->levels_nr == 0)
660 return ref_iterator_abort(ref_iterator);
665 entry = dir->entries[level->index];
667 if (entry->flag & REF_DIR) {
668 /* push down a level */
669 ALLOC_GROW(iter->levels, iter->levels_nr + 1,
672 level = &iter->levels[iter->levels_nr++];
673 level->dir = get_ref_dir(entry);
676 iter->base.refname = entry->name;
677 iter->base.oid = &entry->u.value.oid;
678 iter->base.flags = entry->flag;
684 static enum peel_status peel_entry(struct ref_entry *entry, int repeel);
686 static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator,
687 struct object_id *peeled)
689 struct cache_ref_iterator *iter =
690 (struct cache_ref_iterator *)ref_iterator;
691 struct cache_ref_iterator_level *level;
692 struct ref_entry *entry;
694 level = &iter->levels[iter->levels_nr - 1];
696 if (level->index == -1)
697 die("BUG: peel called before advance for cache iterator");
699 entry = level->dir->entries[level->index];
701 if (peel_entry(entry, 0))
703 oidcpy(peeled, &entry->u.value.peeled);
707 static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator)
709 struct cache_ref_iterator *iter =
710 (struct cache_ref_iterator *)ref_iterator;
713 base_ref_iterator_free(ref_iterator);
717 static struct ref_iterator_vtable cache_ref_iterator_vtable = {
718 cache_ref_iterator_advance,
719 cache_ref_iterator_peel,
720 cache_ref_iterator_abort
723 static struct ref_iterator *cache_ref_iterator_begin(struct ref_dir *dir)
725 struct cache_ref_iterator *iter;
726 struct ref_iterator *ref_iterator;
727 struct cache_ref_iterator_level *level;
729 iter = xcalloc(1, sizeof(*iter));
730 ref_iterator = &iter->base;
731 base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable);
732 ALLOC_GROW(iter->levels, 10, iter->levels_alloc);
735 level = &iter->levels[0];
742 struct nonmatching_ref_data {
743 const struct string_list *skip;
744 const char *conflicting_refname;
747 static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata)
749 struct nonmatching_ref_data *data = vdata;
751 if (data->skip && string_list_has_string(data->skip, entry->name))
754 data->conflicting_refname = entry->name;
759 * Return 0 if a reference named refname could be created without
760 * conflicting with the name of an existing reference in dir.
761 * See verify_refname_available for more information.
763 static int verify_refname_available_dir(const char *refname,
764 const struct string_list *extras,
765 const struct string_list *skip,
770 const char *extra_refname;
772 struct strbuf dirname = STRBUF_INIT;
776 * For the sake of comments in this function, suppose that
777 * refname is "refs/foo/bar".
782 strbuf_grow(&dirname, strlen(refname) + 1);
783 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
784 /* Expand dirname to the new prefix, not including the trailing slash: */
785 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
788 * We are still at a leading dir of the refname (e.g.,
789 * "refs/foo"; if there is a reference with that name,
790 * it is a conflict, *unless* it is in skip.
793 pos = search_ref_dir(dir, dirname.buf, dirname.len);
795 (!skip || !string_list_has_string(skip, dirname.buf))) {
797 * We found a reference whose name is
798 * a proper prefix of refname; e.g.,
799 * "refs/foo", and is not in skip.
801 strbuf_addf(err, "'%s' exists; cannot create '%s'",
802 dirname.buf, refname);
807 if (extras && string_list_has_string(extras, dirname.buf) &&
808 (!skip || !string_list_has_string(skip, dirname.buf))) {
809 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
810 refname, dirname.buf);
815 * Otherwise, we can try to continue our search with
816 * the next component. So try to look up the
817 * directory, e.g., "refs/foo/". If we come up empty,
818 * we know there is nothing under this whole prefix,
819 * but even in that case we still have to continue the
820 * search for conflicts with extras.
822 strbuf_addch(&dirname, '/');
824 pos = search_ref_dir(dir, dirname.buf, dirname.len);
827 * There was no directory "refs/foo/",
828 * so there is nothing under this
829 * whole prefix. So there is no need
830 * to continue looking for conflicting
831 * references. But we need to continue
832 * looking for conflicting extras.
836 dir = get_ref_dir(dir->entries[pos]);
842 * We are at the leaf of our refname (e.g., "refs/foo/bar").
843 * There is no point in searching for a reference with that
844 * name, because a refname isn't considered to conflict with
845 * itself. But we still need to check for references whose
846 * names are in the "refs/foo/bar/" namespace, because they
849 strbuf_addstr(&dirname, refname + dirname.len);
850 strbuf_addch(&dirname, '/');
853 pos = search_ref_dir(dir, dirname.buf, dirname.len);
857 * We found a directory named "$refname/"
858 * (e.g., "refs/foo/bar/"). It is a problem
859 * iff it contains any ref that is not in
862 struct nonmatching_ref_data data;
865 data.conflicting_refname = NULL;
866 dir = get_ref_dir(dir->entries[pos]);
868 if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) {
869 strbuf_addf(err, "'%s' exists; cannot create '%s'",
870 data.conflicting_refname, refname);
876 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
878 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
879 refname, extra_refname);
884 strbuf_release(&dirname);
888 struct packed_ref_cache {
889 struct ref_entry *root;
892 * Count of references to the data structure in this instance,
893 * including the pointer from files_ref_store::packed if any.
894 * The data will not be freed as long as the reference count
897 unsigned int referrers;
900 * Iff the packed-refs file associated with this instance is
901 * currently locked for writing, this points at the associated
902 * lock (which is owned by somebody else). The referrer count
903 * is also incremented when the file is locked and decremented
904 * when it is unlocked.
906 struct lock_file *lock;
908 /* The metadata from when this packed-refs cache was read */
909 struct stat_validity validity;
913 * Future: need to be in "struct repository"
914 * when doing a full libification.
916 struct files_ref_store {
917 struct ref_store base;
920 * The name of the submodule represented by this object, or
921 * NULL if it represents the main repository's reference
924 const char *submodule;
926 char *packed_refs_path;
928 struct ref_entry *loose;
929 struct packed_ref_cache *packed;
932 /* Lock used for the main packed-refs file: */
933 static struct lock_file packlock;
936 * Increment the reference count of *packed_refs.
938 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
940 packed_refs->referrers++;
944 * Decrease the reference count of *packed_refs. If it goes to zero,
945 * free *packed_refs and return true; otherwise return false.
947 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
949 if (!--packed_refs->referrers) {
950 free_ref_entry(packed_refs->root);
951 stat_validity_clear(&packed_refs->validity);
959 static void clear_packed_ref_cache(struct files_ref_store *refs)
962 struct packed_ref_cache *packed_refs = refs->packed;
964 if (packed_refs->lock)
965 die("internal error: packed-ref cache cleared while locked");
967 release_packed_ref_cache(packed_refs);
971 static void clear_loose_ref_cache(struct files_ref_store *refs)
974 free_ref_entry(refs->loose);
980 * Create a new submodule ref cache and add it to the internal
983 static struct ref_store *files_ref_store_create(const char *submodule)
985 struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
986 struct ref_store *ref_store = (struct ref_store *)refs;
988 base_ref_store_init(ref_store, &refs_be_files);
991 refs->submodule = xstrdup(submodule);
992 refs->packed_refs_path = git_pathdup_submodule(
993 refs->submodule, "packed-refs");
997 refs->packed_refs_path = git_pathdup("packed-refs");
1003 * Die if refs is for a submodule (i.e., not for the main repository).
1004 * caller is used in any necessary error messages.
1006 static void files_assert_main_repository(struct files_ref_store *refs,
1009 if (refs->submodule)
1010 die("BUG: %s called for a submodule", caller);
1014 * Downcast ref_store to files_ref_store. Die if ref_store is not a
1015 * files_ref_store. If submodule_allowed is not true, then also die if
1016 * files_ref_store is for a submodule (i.e., not for the main
1017 * repository). caller is used in any necessary error messages.
1019 static struct files_ref_store *files_downcast(
1020 struct ref_store *ref_store, int submodule_allowed,
1023 struct files_ref_store *refs;
1025 if (ref_store->be != &refs_be_files)
1026 die("BUG: ref_store is type \"%s\" not \"files\" in %s",
1027 ref_store->be->name, caller);
1029 refs = (struct files_ref_store *)ref_store;
1031 if (!submodule_allowed)
1032 files_assert_main_repository(refs, caller);
1037 /* The length of a peeled reference line in packed-refs, including EOL: */
1038 #define PEELED_LINE_LENGTH 42
1041 * The packed-refs header line that we write out. Perhaps other
1042 * traits will be added later. The trailing space is required.
1044 static const char PACKED_REFS_HEADER[] =
1045 "# pack-refs with: peeled fully-peeled \n";
1048 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
1049 * Return a pointer to the refname within the line (null-terminated),
1050 * or NULL if there was a problem.
1052 static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1)
1057 * 42: the answer to everything.
1059 * In this case, it happens to be the answer to
1060 * 40 (length of sha1 hex representation)
1061 * +1 (space in between hex and name)
1062 * +1 (newline at the end of the line)
1064 if (line->len <= 42)
1067 if (get_sha1_hex(line->buf, sha1) < 0)
1069 if (!isspace(line->buf[40]))
1072 ref = line->buf + 41;
1076 if (line->buf[line->len - 1] != '\n')
1078 line->buf[--line->len] = 0;
1084 * Read f, which is a packed-refs file, into dir.
1086 * A comment line of the form "# pack-refs with: " may contain zero or
1087 * more traits. We interpret the traits as follows:
1091 * Probably no references are peeled. But if the file contains a
1092 * peeled value for a reference, we will use it.
1096 * References under "refs/tags/", if they *can* be peeled, *are*
1097 * peeled in this file. References outside of "refs/tags/" are
1098 * probably not peeled even if they could have been, but if we find
1099 * a peeled value for such a reference we will use it.
1103 * All references in the file that can be peeled are peeled.
1104 * Inversely (and this is more important), any references in the
1105 * file for which no peeled value is recorded is not peelable. This
1106 * trait should typically be written alongside "peeled" for
1107 * compatibility with older clients, but we do not require it
1108 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1110 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1112 struct ref_entry *last = NULL;
1113 struct strbuf line = STRBUF_INIT;
1114 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1116 while (strbuf_getwholeline(&line, f, '\n') != EOF) {
1117 unsigned char sha1[20];
1118 const char *refname;
1121 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
1122 if (strstr(traits, " fully-peeled "))
1123 peeled = PEELED_FULLY;
1124 else if (strstr(traits, " peeled "))
1125 peeled = PEELED_TAGS;
1126 /* perhaps other traits later as well */
1130 refname = parse_ref_line(&line, sha1);
1132 int flag = REF_ISPACKED;
1134 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1135 if (!refname_is_safe(refname))
1136 die("packed refname is dangerous: %s", refname);
1138 flag |= REF_BAD_NAME | REF_ISBROKEN;
1140 last = create_ref_entry(refname, sha1, flag, 0);
1141 if (peeled == PEELED_FULLY ||
1142 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1143 last->flag |= REF_KNOWS_PEELED;
1148 line.buf[0] == '^' &&
1149 line.len == PEELED_LINE_LENGTH &&
1150 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&
1151 !get_sha1_hex(line.buf + 1, sha1)) {
1152 hashcpy(last->u.value.peeled.hash, sha1);
1154 * Regardless of what the file header said,
1155 * we definitely know the value of *this*
1158 last->flag |= REF_KNOWS_PEELED;
1162 strbuf_release(&line);
1165 static const char *files_packed_refs_path(struct files_ref_store *refs)
1167 return refs->packed_refs_path;
1171 * Get the packed_ref_cache for the specified files_ref_store,
1172 * creating it if necessary.
1174 static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)
1176 const char *packed_refs_file = files_packed_refs_path(refs);
1179 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1180 clear_packed_ref_cache(refs);
1182 if (!refs->packed) {
1185 refs->packed = xcalloc(1, sizeof(*refs->packed));
1186 acquire_packed_ref_cache(refs->packed);
1187 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1188 f = fopen(packed_refs_file, "r");
1190 stat_validity_update(&refs->packed->validity, fileno(f));
1191 read_packed_refs(f, get_ref_dir(refs->packed->root));
1195 return refs->packed;
1198 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1200 return get_ref_dir(packed_ref_cache->root);
1203 static struct ref_dir *get_packed_refs(struct files_ref_store *refs)
1205 return get_packed_ref_dir(get_packed_ref_cache(refs));
1209 * Add a reference to the in-memory packed reference cache. This may
1210 * only be called while the packed-refs file is locked (see
1211 * lock_packed_refs()). To actually write the packed-refs file, call
1212 * commit_packed_refs().
1214 static void add_packed_ref(struct files_ref_store *refs,
1215 const char *refname, const unsigned char *sha1)
1217 struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs);
1219 if (!packed_ref_cache->lock)
1220 die("internal error: packed refs not locked");
1221 add_ref(get_packed_ref_dir(packed_ref_cache),
1222 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1226 * Read the loose references from the namespace dirname into dir
1227 * (without recursing). dirname must end with '/'. dir must be the
1228 * directory entry corresponding to dirname.
1230 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1232 struct files_ref_store *refs = dir->ref_store;
1235 int dirnamelen = strlen(dirname);
1236 struct strbuf refname;
1237 struct strbuf path = STRBUF_INIT;
1238 size_t path_baselen;
1241 if (refs->submodule)
1242 err = strbuf_git_path_submodule(&path, refs->submodule, "%s", dirname);
1244 strbuf_git_path(&path, "%s", dirname);
1245 path_baselen = path.len;
1248 strbuf_release(&path);
1252 d = opendir(path.buf);
1254 strbuf_release(&path);
1258 strbuf_init(&refname, dirnamelen + 257);
1259 strbuf_add(&refname, dirname, dirnamelen);
1261 while ((de = readdir(d)) != NULL) {
1262 unsigned char sha1[20];
1266 if (de->d_name[0] == '.')
1268 if (ends_with(de->d_name, ".lock"))
1270 strbuf_addstr(&refname, de->d_name);
1271 strbuf_addstr(&path, de->d_name);
1272 if (stat(path.buf, &st) < 0) {
1273 ; /* silently ignore */
1274 } else if (S_ISDIR(st.st_mode)) {
1275 strbuf_addch(&refname, '/');
1276 add_entry_to_dir(dir,
1277 create_dir_entry(refs, refname.buf,
1280 if (!resolve_ref_recursively(&refs->base,
1282 RESOLVE_REF_READING,
1285 flag |= REF_ISBROKEN;
1286 } else if (is_null_sha1(sha1)) {
1288 * It is so astronomically unlikely
1289 * that NULL_SHA1 is the SHA-1 of an
1290 * actual object that we consider its
1291 * appearance in a loose reference
1292 * file to be repo corruption
1293 * (probably due to a software bug).
1295 flag |= REF_ISBROKEN;
1298 if (check_refname_format(refname.buf,
1299 REFNAME_ALLOW_ONELEVEL)) {
1300 if (!refname_is_safe(refname.buf))
1301 die("loose refname is dangerous: %s", refname.buf);
1303 flag |= REF_BAD_NAME | REF_ISBROKEN;
1305 add_entry_to_dir(dir,
1306 create_ref_entry(refname.buf, sha1, flag, 0));
1308 strbuf_setlen(&refname, dirnamelen);
1309 strbuf_setlen(&path, path_baselen);
1311 strbuf_release(&refname);
1312 strbuf_release(&path);
1316 static struct ref_dir *get_loose_refs(struct files_ref_store *refs)
1320 * Mark the top-level directory complete because we
1321 * are about to read the only subdirectory that can
1324 refs->loose = create_dir_entry(refs, "", 0, 0);
1326 * Create an incomplete entry for "refs/":
1328 add_entry_to_dir(get_ref_dir(refs->loose),
1329 create_dir_entry(refs, "refs/", 5, 1));
1331 return get_ref_dir(refs->loose);
1335 * Return the ref_entry for the given refname from the packed
1336 * references. If it does not exist, return NULL.
1338 static struct ref_entry *get_packed_ref(struct files_ref_store *refs,
1339 const char *refname)
1341 return find_ref(get_packed_refs(refs), refname);
1345 * A loose ref file doesn't exist; check for a packed ref.
1347 static int resolve_packed_ref(struct files_ref_store *refs,
1348 const char *refname,
1349 unsigned char *sha1, unsigned int *flags)
1351 struct ref_entry *entry;
1354 * The loose reference file does not exist; check for a packed
1357 entry = get_packed_ref(refs, refname);
1359 hashcpy(sha1, entry->u.value.oid.hash);
1360 *flags |= REF_ISPACKED;
1363 /* refname is not a packed reference. */
1367 static int files_read_raw_ref(struct ref_store *ref_store,
1368 const char *refname, unsigned char *sha1,
1369 struct strbuf *referent, unsigned int *type)
1371 struct files_ref_store *refs =
1372 files_downcast(ref_store, 1, "read_raw_ref");
1373 struct strbuf sb_contents = STRBUF_INIT;
1374 struct strbuf sb_path = STRBUF_INIT;
1381 int remaining_retries = 3;
1384 strbuf_reset(&sb_path);
1386 if (refs->submodule)
1387 strbuf_git_path_submodule(&sb_path, refs->submodule, "%s", refname);
1389 strbuf_git_path(&sb_path, "%s", refname);
1395 * We might have to loop back here to avoid a race
1396 * condition: first we lstat() the file, then we try
1397 * to read it as a link or as a file. But if somebody
1398 * changes the type of the file (file <-> directory
1399 * <-> symlink) between the lstat() and reading, then
1400 * we don't want to report that as an error but rather
1401 * try again starting with the lstat().
1403 * We'll keep a count of the retries, though, just to avoid
1404 * any confusing situation sending us into an infinite loop.
1407 if (remaining_retries-- <= 0)
1410 if (lstat(path, &st) < 0) {
1411 if (errno != ENOENT)
1413 if (resolve_packed_ref(refs, refname, sha1, type)) {
1421 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1422 if (S_ISLNK(st.st_mode)) {
1423 strbuf_reset(&sb_contents);
1424 if (strbuf_readlink(&sb_contents, path, 0) < 0) {
1425 if (errno == ENOENT || errno == EINVAL)
1426 /* inconsistent with lstat; retry */
1431 if (starts_with(sb_contents.buf, "refs/") &&
1432 !check_refname_format(sb_contents.buf, 0)) {
1433 strbuf_swap(&sb_contents, referent);
1434 *type |= REF_ISSYMREF;
1439 * It doesn't look like a refname; fall through to just
1440 * treating it like a non-symlink, and reading whatever it
1445 /* Is it a directory? */
1446 if (S_ISDIR(st.st_mode)) {
1448 * Even though there is a directory where the loose
1449 * ref is supposed to be, there could still be a
1452 if (resolve_packed_ref(refs, refname, sha1, type)) {
1461 * Anything else, just open it and try to use it as
1464 fd = open(path, O_RDONLY);
1466 if (errno == ENOENT && !S_ISLNK(st.st_mode))
1467 /* inconsistent with lstat; retry */
1472 strbuf_reset(&sb_contents);
1473 if (strbuf_read(&sb_contents, fd, 256) < 0) {
1474 int save_errno = errno;
1480 strbuf_rtrim(&sb_contents);
1481 buf = sb_contents.buf;
1482 if (starts_with(buf, "ref:")) {
1484 while (isspace(*buf))
1487 strbuf_reset(referent);
1488 strbuf_addstr(referent, buf);
1489 *type |= REF_ISSYMREF;
1495 * Please note that FETCH_HEAD has additional
1496 * data after the sha.
1498 if (get_sha1_hex(buf, sha1) ||
1499 (buf[40] != '\0' && !isspace(buf[40]))) {
1500 *type |= REF_ISBROKEN;
1509 strbuf_release(&sb_path);
1510 strbuf_release(&sb_contents);
1515 static void unlock_ref(struct ref_lock *lock)
1517 /* Do not free lock->lk -- atexit() still looks at them */
1519 rollback_lock_file(lock->lk);
1520 free(lock->ref_name);
1525 * Lock refname, without following symrefs, and set *lock_p to point
1526 * at a newly-allocated lock object. Fill in lock->old_oid, referent,
1527 * and type similarly to read_raw_ref().
1529 * The caller must verify that refname is a "safe" reference name (in
1530 * the sense of refname_is_safe()) before calling this function.
1532 * If the reference doesn't already exist, verify that refname doesn't
1533 * have a D/F conflict with any existing references. extras and skip
1534 * are passed to verify_refname_available_dir() for this check.
1536 * If mustexist is not set and the reference is not found or is
1537 * broken, lock the reference anyway but clear sha1.
1539 * Return 0 on success. On failure, write an error message to err and
1540 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
1542 * Implementation note: This function is basically
1547 * but it includes a lot more code to
1548 * - Deal with possible races with other processes
1549 * - Avoid calling verify_refname_available_dir() when it can be
1550 * avoided, namely if we were successfully able to read the ref
1551 * - Generate informative error messages in the case of failure
1553 static int lock_raw_ref(struct files_ref_store *refs,
1554 const char *refname, int mustexist,
1555 const struct string_list *extras,
1556 const struct string_list *skip,
1557 struct ref_lock **lock_p,
1558 struct strbuf *referent,
1562 struct ref_lock *lock;
1563 struct strbuf ref_file = STRBUF_INIT;
1564 int attempts_remaining = 3;
1565 int ret = TRANSACTION_GENERIC_ERROR;
1568 files_assert_main_repository(refs, "lock_raw_ref");
1572 /* First lock the file so it can't change out from under us. */
1574 *lock_p = lock = xcalloc(1, sizeof(*lock));
1576 lock->ref_name = xstrdup(refname);
1577 strbuf_git_path(&ref_file, "%s", refname);
1580 switch (safe_create_leading_directories(ref_file.buf)) {
1582 break; /* success */
1585 * Suppose refname is "refs/foo/bar". We just failed
1586 * to create the containing directory, "refs/foo",
1587 * because there was a non-directory in the way. This
1588 * indicates a D/F conflict, probably because of
1589 * another reference such as "refs/foo". There is no
1590 * reason to expect this error to be transitory.
1592 if (verify_refname_available(refname, extras, skip, err)) {
1595 * To the user the relevant error is
1596 * that the "mustexist" reference is
1600 strbuf_addf(err, "unable to resolve reference '%s'",
1604 * The error message set by
1605 * verify_refname_available_dir() is OK.
1607 ret = TRANSACTION_NAME_CONFLICT;
1611 * The file that is in the way isn't a loose
1612 * reference. Report it as a low-level
1615 strbuf_addf(err, "unable to create lock file %s.lock; "
1616 "non-directory in the way",
1621 /* Maybe another process was tidying up. Try again. */
1622 if (--attempts_remaining > 0)
1626 strbuf_addf(err, "unable to create directory for %s",
1632 lock->lk = xcalloc(1, sizeof(struct lock_file));
1634 if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) {
1635 if (errno == ENOENT && --attempts_remaining > 0) {
1637 * Maybe somebody just deleted one of the
1638 * directories leading to ref_file. Try
1643 unable_to_lock_message(ref_file.buf, errno, err);
1649 * Now we hold the lock and can read the reference without
1650 * fear that its value will change.
1653 if (files_read_raw_ref(&refs->base, refname,
1654 lock->old_oid.hash, referent, type)) {
1655 if (errno == ENOENT) {
1657 /* Garden variety missing reference. */
1658 strbuf_addf(err, "unable to resolve reference '%s'",
1663 * Reference is missing, but that's OK. We
1664 * know that there is not a conflict with
1665 * another loose reference because
1666 * (supposing that we are trying to lock
1667 * reference "refs/foo/bar"):
1669 * - We were successfully able to create
1670 * the lockfile refs/foo/bar.lock, so we
1671 * know there cannot be a loose reference
1674 * - We got ENOENT and not EISDIR, so we
1675 * know that there cannot be a loose
1676 * reference named "refs/foo/bar/baz".
1679 } else if (errno == EISDIR) {
1681 * There is a directory in the way. It might have
1682 * contained references that have been deleted. If
1683 * we don't require that the reference already
1684 * exists, try to remove the directory so that it
1685 * doesn't cause trouble when we want to rename the
1686 * lockfile into place later.
1689 /* Garden variety missing reference. */
1690 strbuf_addf(err, "unable to resolve reference '%s'",
1693 } else if (remove_dir_recursively(&ref_file,
1694 REMOVE_DIR_EMPTY_ONLY)) {
1695 if (verify_refname_available_dir(
1696 refname, extras, skip,
1697 get_loose_refs(refs),
1700 * The error message set by
1701 * verify_refname_available() is OK.
1703 ret = TRANSACTION_NAME_CONFLICT;
1707 * We can't delete the directory,
1708 * but we also don't know of any
1709 * references that it should
1712 strbuf_addf(err, "there is a non-empty directory '%s' "
1713 "blocking reference '%s'",
1714 ref_file.buf, refname);
1718 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {
1719 strbuf_addf(err, "unable to resolve reference '%s': "
1720 "reference broken", refname);
1723 strbuf_addf(err, "unable to resolve reference '%s': %s",
1724 refname, strerror(errno));
1729 * If the ref did not exist and we are creating it,
1730 * make sure there is no existing packed ref whose
1731 * name begins with our refname, nor a packed ref
1732 * whose name is a proper prefix of our refname.
1734 if (verify_refname_available_dir(
1735 refname, extras, skip,
1736 get_packed_refs(refs),
1750 strbuf_release(&ref_file);
1755 * Peel the entry (if possible) and return its new peel_status. If
1756 * repeel is true, re-peel the entry even if there is an old peeled
1757 * value that is already stored in it.
1759 * It is OK to call this function with a packed reference entry that
1760 * might be stale and might even refer to an object that has since
1761 * been garbage-collected. In such a case, if the entry has
1762 * REF_KNOWS_PEELED then leave the status unchanged and return
1763 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1765 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1767 enum peel_status status;
1769 if (entry->flag & REF_KNOWS_PEELED) {
1771 entry->flag &= ~REF_KNOWS_PEELED;
1772 oidclr(&entry->u.value.peeled);
1774 return is_null_oid(&entry->u.value.peeled) ?
1775 PEEL_NON_TAG : PEEL_PEELED;
1778 if (entry->flag & REF_ISBROKEN)
1780 if (entry->flag & REF_ISSYMREF)
1781 return PEEL_IS_SYMREF;
1783 status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);
1784 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1785 entry->flag |= REF_KNOWS_PEELED;
1789 static int files_peel_ref(struct ref_store *ref_store,
1790 const char *refname, unsigned char *sha1)
1792 struct files_ref_store *refs = files_downcast(ref_store, 0, "peel_ref");
1794 unsigned char base[20];
1796 if (current_ref_iter && current_ref_iter->refname == refname) {
1797 struct object_id peeled;
1799 if (ref_iterator_peel(current_ref_iter, &peeled))
1801 hashcpy(sha1, peeled.hash);
1805 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))
1809 * If the reference is packed, read its ref_entry from the
1810 * cache in the hope that we already know its peeled value.
1811 * We only try this optimization on packed references because
1812 * (a) forcing the filling of the loose reference cache could
1813 * be expensive and (b) loose references anyway usually do not
1814 * have REF_KNOWS_PEELED.
1816 if (flag & REF_ISPACKED) {
1817 struct ref_entry *r = get_packed_ref(refs, refname);
1819 if (peel_entry(r, 0))
1821 hashcpy(sha1, r->u.value.peeled.hash);
1826 return peel_object(base, sha1);
1829 struct files_ref_iterator {
1830 struct ref_iterator base;
1832 struct packed_ref_cache *packed_ref_cache;
1833 struct ref_iterator *iter0;
1837 static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
1839 struct files_ref_iterator *iter =
1840 (struct files_ref_iterator *)ref_iterator;
1843 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
1844 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
1845 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
1848 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
1849 !ref_resolves_to_object(iter->iter0->refname,
1851 iter->iter0->flags))
1854 iter->base.refname = iter->iter0->refname;
1855 iter->base.oid = iter->iter0->oid;
1856 iter->base.flags = iter->iter0->flags;
1861 if (ref_iterator_abort(ref_iterator) != ITER_DONE)
1867 static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,
1868 struct object_id *peeled)
1870 struct files_ref_iterator *iter =
1871 (struct files_ref_iterator *)ref_iterator;
1873 return ref_iterator_peel(iter->iter0, peeled);
1876 static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)
1878 struct files_ref_iterator *iter =
1879 (struct files_ref_iterator *)ref_iterator;
1883 ok = ref_iterator_abort(iter->iter0);
1885 release_packed_ref_cache(iter->packed_ref_cache);
1886 base_ref_iterator_free(ref_iterator);
1890 static struct ref_iterator_vtable files_ref_iterator_vtable = {
1891 files_ref_iterator_advance,
1892 files_ref_iterator_peel,
1893 files_ref_iterator_abort
1896 static struct ref_iterator *files_ref_iterator_begin(
1897 struct ref_store *ref_store,
1898 const char *prefix, unsigned int flags)
1900 struct files_ref_store *refs =
1901 files_downcast(ref_store, 1, "ref_iterator_begin");
1902 struct ref_dir *loose_dir, *packed_dir;
1903 struct ref_iterator *loose_iter, *packed_iter;
1904 struct files_ref_iterator *iter;
1905 struct ref_iterator *ref_iterator;
1907 if (ref_paranoia < 0)
1908 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1910 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1912 iter = xcalloc(1, sizeof(*iter));
1913 ref_iterator = &iter->base;
1914 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);
1917 * We must make sure that all loose refs are read before
1918 * accessing the packed-refs file; this avoids a race
1919 * condition if loose refs are migrated to the packed-refs
1920 * file by a simultaneous process, but our in-memory view is
1921 * from before the migration. We ensure this as follows:
1922 * First, we call prime_ref_dir(), which pre-reads the loose
1923 * references for the subtree into the cache. (If they've
1924 * already been read, that's OK; we only need to guarantee
1925 * that they're read before the packed refs, not *how much*
1926 * before.) After that, we call get_packed_ref_cache(), which
1927 * internally checks whether the packed-ref cache is up to
1928 * date with what is on disk, and re-reads it if not.
1931 loose_dir = get_loose_refs(refs);
1933 if (prefix && *prefix)
1934 loose_dir = find_containing_dir(loose_dir, prefix, 0);
1937 prime_ref_dir(loose_dir);
1938 loose_iter = cache_ref_iterator_begin(loose_dir);
1940 /* There's nothing to iterate over. */
1941 loose_iter = empty_ref_iterator_begin();
1944 iter->packed_ref_cache = get_packed_ref_cache(refs);
1945 acquire_packed_ref_cache(iter->packed_ref_cache);
1946 packed_dir = get_packed_ref_dir(iter->packed_ref_cache);
1948 if (prefix && *prefix)
1949 packed_dir = find_containing_dir(packed_dir, prefix, 0);
1952 packed_iter = cache_ref_iterator_begin(packed_dir);
1954 /* There's nothing to iterate over. */
1955 packed_iter = empty_ref_iterator_begin();
1958 iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);
1959 iter->flags = flags;
1961 return ref_iterator;
1965 * Verify that the reference locked by lock has the value old_sha1.
1966 * Fail if the reference doesn't exist and mustexist is set. Return 0
1967 * on success. On error, write an error message to err, set errno, and
1968 * return a negative value.
1970 static int verify_lock(struct ref_lock *lock,
1971 const unsigned char *old_sha1, int mustexist,
1976 if (read_ref_full(lock->ref_name,
1977 mustexist ? RESOLVE_REF_READING : 0,
1978 lock->old_oid.hash, NULL)) {
1980 int save_errno = errno;
1981 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);
1985 oidclr(&lock->old_oid);
1989 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {
1990 strbuf_addf(err, "ref '%s' is at %s but expected %s",
1992 oid_to_hex(&lock->old_oid),
1993 sha1_to_hex(old_sha1));
2000 static int remove_empty_directories(struct strbuf *path)
2003 * we want to create a file but there is a directory there;
2004 * if that is an empty directory (or a directory that contains
2005 * only empty directories), remove them.
2007 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
2010 static int create_reflock(const char *path, void *cb)
2012 struct lock_file *lk = cb;
2014 return hold_lock_file_for_update(lk, path, LOCK_NO_DEREF) < 0 ? -1 : 0;
2018 * Locks a ref returning the lock on success and NULL on failure.
2019 * On failure errno is set to something meaningful.
2021 static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,
2022 const char *refname,
2023 const unsigned char *old_sha1,
2024 const struct string_list *extras,
2025 const struct string_list *skip,
2026 unsigned int flags, int *type,
2029 struct strbuf ref_file = STRBUF_INIT;
2030 struct ref_lock *lock;
2032 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2033 int resolve_flags = RESOLVE_REF_NO_RECURSE;
2036 files_assert_main_repository(refs, "lock_ref_sha1_basic");
2039 lock = xcalloc(1, sizeof(struct ref_lock));
2042 resolve_flags |= RESOLVE_REF_READING;
2043 if (flags & REF_DELETING)
2044 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
2046 strbuf_git_path(&ref_file, "%s", refname);
2047 resolved = !!resolve_ref_unsafe(refname, resolve_flags,
2048 lock->old_oid.hash, type);
2049 if (!resolved && errno == EISDIR) {
2051 * we are trying to lock foo but we used to
2052 * have foo/bar which now does not exist;
2053 * it is normal for the empty directory 'foo'
2056 if (remove_empty_directories(&ref_file)) {
2058 if (!verify_refname_available_dir(
2059 refname, extras, skip,
2060 get_loose_refs(refs), err))
2061 strbuf_addf(err, "there are still refs under '%s'",
2065 resolved = !!resolve_ref_unsafe(refname, resolve_flags,
2066 lock->old_oid.hash, type);
2070 if (last_errno != ENOTDIR ||
2071 !verify_refname_available_dir(
2072 refname, extras, skip,
2073 get_loose_refs(refs), err))
2074 strbuf_addf(err, "unable to resolve reference '%s': %s",
2075 refname, strerror(last_errno));
2081 * If the ref did not exist and we are creating it, make sure
2082 * there is no existing packed ref whose name begins with our
2083 * refname, nor a packed ref whose name is a proper prefix of
2086 if (is_null_oid(&lock->old_oid) &&
2087 verify_refname_available_dir(refname, extras, skip,
2088 get_packed_refs(refs),
2090 last_errno = ENOTDIR;
2094 lock->lk = xcalloc(1, sizeof(struct lock_file));
2096 lock->ref_name = xstrdup(refname);
2098 if (raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {
2100 unable_to_lock_message(ref_file.buf, errno, err);
2104 if (verify_lock(lock, old_sha1, mustexist, err)) {
2115 strbuf_release(&ref_file);
2121 * Write an entry to the packed-refs file for the specified refname.
2122 * If peeled is non-NULL, write it as the entry's peeled value.
2124 static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,
2125 unsigned char *peeled)
2127 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);
2129 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));
2133 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2135 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2137 enum peel_status peel_status = peel_entry(entry, 0);
2139 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2140 error("internal error: %s is not a valid packed reference!",
2142 write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,
2143 peel_status == PEEL_PEELED ?
2144 entry->u.value.peeled.hash : NULL);
2149 * Lock the packed-refs file for writing. Flags is passed to
2150 * hold_lock_file_for_update(). Return 0 on success. On errors, set
2151 * errno appropriately and return a nonzero value.
2153 static int lock_packed_refs(struct files_ref_store *refs, int flags)
2155 static int timeout_configured = 0;
2156 static int timeout_value = 1000;
2157 struct packed_ref_cache *packed_ref_cache;
2159 files_assert_main_repository(refs, "lock_packed_refs");
2161 if (!timeout_configured) {
2162 git_config_get_int("core.packedrefstimeout", &timeout_value);
2163 timeout_configured = 1;
2166 if (hold_lock_file_for_update_timeout(
2167 &packlock, files_packed_refs_path(refs),
2168 flags, timeout_value) < 0)
2171 * Get the current packed-refs while holding the lock. If the
2172 * packed-refs file has been modified since we last read it,
2173 * this will automatically invalidate the cache and re-read
2174 * the packed-refs file.
2176 packed_ref_cache = get_packed_ref_cache(refs);
2177 packed_ref_cache->lock = &packlock;
2178 /* Increment the reference count to prevent it from being freed: */
2179 acquire_packed_ref_cache(packed_ref_cache);
2184 * Write the current version of the packed refs cache from memory to
2185 * disk. The packed-refs file must already be locked for writing (see
2186 * lock_packed_refs()). Return zero on success. On errors, set errno
2187 * and return a nonzero value
2189 static int commit_packed_refs(struct files_ref_store *refs)
2191 struct packed_ref_cache *packed_ref_cache =
2192 get_packed_ref_cache(refs);
2197 files_assert_main_repository(refs, "commit_packed_refs");
2199 if (!packed_ref_cache->lock)
2200 die("internal error: packed-refs not locked");
2202 out = fdopen_lock_file(packed_ref_cache->lock, "w");
2204 die_errno("unable to fdopen packed-refs descriptor");
2206 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);
2207 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2208 0, write_packed_entry_fn, out);
2210 if (commit_lock_file(packed_ref_cache->lock)) {
2214 packed_ref_cache->lock = NULL;
2215 release_packed_ref_cache(packed_ref_cache);
2221 * Rollback the lockfile for the packed-refs file, and discard the
2222 * in-memory packed reference cache. (The packed-refs file will be
2223 * read anew if it is needed again after this function is called.)
2225 static void rollback_packed_refs(struct files_ref_store *refs)
2227 struct packed_ref_cache *packed_ref_cache =
2228 get_packed_ref_cache(refs);
2230 files_assert_main_repository(refs, "rollback_packed_refs");
2232 if (!packed_ref_cache->lock)
2233 die("internal error: packed-refs not locked");
2234 rollback_lock_file(packed_ref_cache->lock);
2235 packed_ref_cache->lock = NULL;
2236 release_packed_ref_cache(packed_ref_cache);
2237 clear_packed_ref_cache(refs);
2240 struct ref_to_prune {
2241 struct ref_to_prune *next;
2242 unsigned char sha1[20];
2243 char name[FLEX_ARRAY];
2246 struct pack_refs_cb_data {
2248 struct ref_dir *packed_refs;
2249 struct ref_to_prune *ref_to_prune;
2253 * An each_ref_entry_fn that is run over loose references only. If
2254 * the loose reference can be packed, add an entry in the packed ref
2255 * cache. If the reference should be pruned, also add it to
2256 * ref_to_prune in the pack_refs_cb_data.
2258 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2260 struct pack_refs_cb_data *cb = cb_data;
2261 enum peel_status peel_status;
2262 struct ref_entry *packed_entry;
2263 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2265 /* Do not pack per-worktree refs: */
2266 if (ref_type(entry->name) != REF_TYPE_NORMAL)
2269 /* ALWAYS pack tags */
2270 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2273 /* Do not pack symbolic or broken refs: */
2274 if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))
2277 /* Add a packed ref cache entry equivalent to the loose entry. */
2278 peel_status = peel_entry(entry, 1);
2279 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2280 die("internal error peeling reference %s (%s)",
2281 entry->name, oid_to_hex(&entry->u.value.oid));
2282 packed_entry = find_ref(cb->packed_refs, entry->name);
2284 /* Overwrite existing packed entry with info from loose entry */
2285 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2286 oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);
2288 packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash,
2289 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2290 add_ref(cb->packed_refs, packed_entry);
2292 oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);
2294 /* Schedule the loose reference for pruning if requested. */
2295 if ((cb->flags & PACK_REFS_PRUNE)) {
2296 struct ref_to_prune *n;
2297 FLEX_ALLOC_STR(n, name, entry->name);
2298 hashcpy(n->sha1, entry->u.value.oid.hash);
2299 n->next = cb->ref_to_prune;
2300 cb->ref_to_prune = n;
2306 REMOVE_EMPTY_PARENTS_REF = 0x01,
2307 REMOVE_EMPTY_PARENTS_REFLOG = 0x02
2311 * Remove empty parent directories associated with the specified
2312 * reference and/or its reflog, but spare [logs/]refs/ and immediate
2313 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or
2314 * REMOVE_EMPTY_PARENTS_REFLOG.
2316 static void try_remove_empty_parents(const char *refname, unsigned int flags)
2318 struct strbuf buf = STRBUF_INIT;
2319 struct strbuf sb = STRBUF_INIT;
2323 strbuf_addstr(&buf, refname);
2325 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2326 while (*p && *p != '/')
2328 /* tolerate duplicate slashes; see check_refname_format() */
2332 q = buf.buf + buf.len;
2333 while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {
2334 while (q > p && *q != '/')
2336 while (q > p && *(q-1) == '/')
2340 strbuf_setlen(&buf, q - buf.buf);
2343 strbuf_git_path(&sb, "%s", buf.buf);
2344 if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))
2345 flags &= ~REMOVE_EMPTY_PARENTS_REF;
2348 strbuf_git_path(&sb, "logs/%s", buf.buf);
2349 if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf))
2350 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;
2352 strbuf_release(&buf);
2353 strbuf_release(&sb);
2356 /* make sure nobody touched the ref, and unlink */
2357 static void prune_ref(struct ref_to_prune *r)
2359 struct ref_transaction *transaction;
2360 struct strbuf err = STRBUF_INIT;
2362 if (check_refname_format(r->name, 0))
2365 transaction = ref_transaction_begin(&err);
2367 ref_transaction_delete(transaction, r->name, r->sha1,
2368 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||
2369 ref_transaction_commit(transaction, &err)) {
2370 ref_transaction_free(transaction);
2371 error("%s", err.buf);
2372 strbuf_release(&err);
2375 ref_transaction_free(transaction);
2376 strbuf_release(&err);
2379 static void prune_refs(struct ref_to_prune *r)
2387 static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
2389 struct files_ref_store *refs =
2390 files_downcast(ref_store, 0, "pack_refs");
2391 struct pack_refs_cb_data cbdata;
2393 memset(&cbdata, 0, sizeof(cbdata));
2394 cbdata.flags = flags;
2396 lock_packed_refs(refs, LOCK_DIE_ON_ERROR);
2397 cbdata.packed_refs = get_packed_refs(refs);
2399 do_for_each_entry_in_dir(get_loose_refs(refs), 0,
2400 pack_if_possible_fn, &cbdata);
2402 if (commit_packed_refs(refs))
2403 die_errno("unable to overwrite old ref-pack file");
2405 prune_refs(cbdata.ref_to_prune);
2410 * Rewrite the packed-refs file, omitting any refs listed in
2411 * 'refnames'. On error, leave packed-refs unchanged, write an error
2412 * message to 'err', and return a nonzero value.
2414 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.
2416 static int repack_without_refs(struct files_ref_store *refs,
2417 struct string_list *refnames, struct strbuf *err)
2419 struct ref_dir *packed;
2420 struct string_list_item *refname;
2421 int ret, needs_repacking = 0, removed = 0;
2423 files_assert_main_repository(refs, "repack_without_refs");
2426 /* Look for a packed ref */
2427 for_each_string_list_item(refname, refnames) {
2428 if (get_packed_ref(refs, refname->string)) {
2429 needs_repacking = 1;
2434 /* Avoid locking if we have nothing to do */
2435 if (!needs_repacking)
2436 return 0; /* no refname exists in packed refs */
2438 if (lock_packed_refs(refs, 0)) {
2439 unable_to_lock_message(files_packed_refs_path(refs), errno, err);
2442 packed = get_packed_refs(refs);
2444 /* Remove refnames from the cache */
2445 for_each_string_list_item(refname, refnames)
2446 if (remove_entry(packed, refname->string) != -1)
2450 * All packed entries disappeared while we were
2451 * acquiring the lock.
2453 rollback_packed_refs(refs);
2457 /* Write what remains */
2458 ret = commit_packed_refs(refs);
2460 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",
2465 static int files_delete_refs(struct ref_store *ref_store,
2466 struct string_list *refnames, unsigned int flags)
2468 struct files_ref_store *refs =
2469 files_downcast(ref_store, 0, "delete_refs");
2470 struct strbuf err = STRBUF_INIT;
2476 result = repack_without_refs(refs, refnames, &err);
2479 * If we failed to rewrite the packed-refs file, then
2480 * it is unsafe to try to remove loose refs, because
2481 * doing so might expose an obsolete packed value for
2482 * a reference that might even point at an object that
2483 * has been garbage collected.
2485 if (refnames->nr == 1)
2486 error(_("could not delete reference %s: %s"),
2487 refnames->items[0].string, err.buf);
2489 error(_("could not delete references: %s"), err.buf);
2494 for (i = 0; i < refnames->nr; i++) {
2495 const char *refname = refnames->items[i].string;
2497 if (delete_ref(NULL, refname, NULL, flags))
2498 result |= error(_("could not remove reference %s"), refname);
2502 strbuf_release(&err);
2507 * People using contrib's git-new-workdir have .git/logs/refs ->
2508 * /some/other/path/.git/logs/refs, and that may live on another device.
2510 * IOW, to avoid cross device rename errors, the temporary renamed log must
2511 * live into logs/refs.
2513 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2516 const char *tmp_renamed_log;
2520 static int rename_tmp_log_callback(const char *path, void *cb_data)
2522 struct rename_cb *cb = cb_data;
2524 if (rename(cb->tmp_renamed_log, path)) {
2526 * rename(a, b) when b is an existing directory ought
2527 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.
2528 * Sheesh. Record the true errno for error reporting,
2529 * but report EISDIR to raceproof_create_file() so
2530 * that it knows to retry.
2532 cb->true_errno = errno;
2533 if (errno == ENOTDIR)
2541 static int rename_tmp_log(const char *newrefname)
2543 struct strbuf path = STRBUF_INIT;
2544 struct strbuf tmp = STRBUF_INIT;
2545 struct rename_cb cb;
2548 strbuf_git_path(&path, "logs/%s", newrefname);
2549 strbuf_git_path(&tmp, TMP_RENAMED_LOG);
2550 cb.tmp_renamed_log = tmp.buf;
2551 ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);
2553 if (errno == EISDIR)
2554 error("directory not empty: %s", path.buf);
2556 error("unable to move logfile %s to %s: %s",
2558 strerror(cb.true_errno));
2561 strbuf_release(&path);
2562 strbuf_release(&tmp);
2566 static int files_verify_refname_available(struct ref_store *ref_store,
2567 const char *newname,
2568 const struct string_list *extras,
2569 const struct string_list *skip,
2572 struct files_ref_store *refs =
2573 files_downcast(ref_store, 1, "verify_refname_available");
2574 struct ref_dir *packed_refs = get_packed_refs(refs);
2575 struct ref_dir *loose_refs = get_loose_refs(refs);
2577 if (verify_refname_available_dir(newname, extras, skip,
2578 packed_refs, err) ||
2579 verify_refname_available_dir(newname, extras, skip,
2586 static int write_ref_to_lockfile(struct ref_lock *lock,
2587 const unsigned char *sha1, struct strbuf *err);
2588 static int commit_ref_update(struct files_ref_store *refs,
2589 struct ref_lock *lock,
2590 const unsigned char *sha1, const char *logmsg,
2591 struct strbuf *err);
2593 static int files_rename_ref(struct ref_store *ref_store,
2594 const char *oldrefname, const char *newrefname,
2597 struct files_ref_store *refs =
2598 files_downcast(ref_store, 0, "rename_ref");
2599 unsigned char sha1[20], orig_sha1[20];
2600 int flag = 0, logmoved = 0;
2601 struct ref_lock *lock;
2602 struct stat loginfo;
2603 struct strbuf sb_oldref = STRBUF_INIT;
2604 struct strbuf sb_newref = STRBUF_INIT;
2605 struct strbuf tmp_renamed_log = STRBUF_INIT;
2607 struct strbuf err = STRBUF_INIT;
2609 strbuf_git_path(&sb_oldref, "logs/%s", oldrefname);
2610 strbuf_git_path(&sb_newref, "logs/%s", newrefname);
2611 strbuf_git_path(&tmp_renamed_log, TMP_RENAMED_LOG);
2613 log = !lstat(sb_oldref.buf, &loginfo);
2614 if (log && S_ISLNK(loginfo.st_mode)) {
2615 ret = error("reflog for %s is a symlink", oldrefname);
2619 if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
2620 orig_sha1, &flag)) {
2621 ret = error("refname %s not found", oldrefname);
2625 if (flag & REF_ISSYMREF) {
2626 ret = error("refname %s is a symbolic ref, renaming it is not supported",
2630 if (!rename_ref_available(oldrefname, newrefname)) {
2635 if (log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {
2636 ret = error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2637 oldrefname, strerror(errno));
2641 if (delete_ref(logmsg, oldrefname, orig_sha1, REF_NODEREF)) {
2642 error("unable to delete old %s", oldrefname);
2647 * Since we are doing a shallow lookup, sha1 is not the
2648 * correct value to pass to delete_ref as old_sha1. But that
2649 * doesn't matter, because an old_sha1 check wouldn't add to
2650 * the safety anyway; we want to delete the reference whatever
2651 * its current value.
2653 if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
2655 delete_ref(NULL, newrefname, NULL, REF_NODEREF)) {
2656 if (errno == EISDIR) {
2657 struct strbuf path = STRBUF_INIT;
2660 strbuf_git_path(&path, "%s", newrefname);
2661 result = remove_empty_directories(&path);
2662 strbuf_release(&path);
2665 error("Directory not empty: %s", newrefname);
2669 error("unable to delete existing %s", newrefname);
2674 if (log && rename_tmp_log(newrefname))
2679 lock = lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,
2680 REF_NODEREF, NULL, &err);
2682 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
2683 strbuf_release(&err);
2686 hashcpy(lock->old_oid.hash, orig_sha1);
2688 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
2689 commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {
2690 error("unable to write current sha1 into %s: %s", newrefname, err.buf);
2691 strbuf_release(&err);
2699 lock = lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,
2700 REF_NODEREF, NULL, &err);
2702 error("unable to lock %s for rollback: %s", oldrefname, err.buf);
2703 strbuf_release(&err);
2707 flag = log_all_ref_updates;
2708 log_all_ref_updates = LOG_REFS_NONE;
2709 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
2710 commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {
2711 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
2712 strbuf_release(&err);
2714 log_all_ref_updates = flag;
2717 if (logmoved && rename(sb_newref.buf, sb_oldref.buf))
2718 error("unable to restore logfile %s from %s: %s",
2719 oldrefname, newrefname, strerror(errno));
2720 if (!logmoved && log &&
2721 rename(tmp_renamed_log.buf, sb_oldref.buf))
2722 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2723 oldrefname, strerror(errno));
2726 strbuf_release(&sb_newref);
2727 strbuf_release(&sb_oldref);
2728 strbuf_release(&tmp_renamed_log);
2733 static int close_ref(struct ref_lock *lock)
2735 if (close_lock_file(lock->lk))
2740 static int commit_ref(struct ref_lock *lock)
2742 char *path = get_locked_file_path(lock->lk);
2745 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {
2747 * There is a directory at the path we want to rename
2748 * the lockfile to. Hopefully it is empty; try to
2751 size_t len = strlen(path);
2752 struct strbuf sb_path = STRBUF_INIT;
2754 strbuf_attach(&sb_path, path, len, len);
2757 * If this fails, commit_lock_file() will also fail
2758 * and will report the problem.
2760 remove_empty_directories(&sb_path);
2761 strbuf_release(&sb_path);
2766 if (commit_lock_file(lock->lk))
2771 static int open_or_create_logfile(const char *path, void *cb)
2775 *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);
2776 return (*fd < 0) ? -1 : 0;
2780 * Create a reflog for a ref. If force_create = 0, only create the
2781 * reflog for certain refs (those for which should_autocreate_reflog
2782 * returns non-zero). Otherwise, create it regardless of the reference
2783 * name. If the logfile already existed or was created, return 0 and
2784 * set *logfd to the file descriptor opened for appending to the file.
2785 * If no logfile exists and we decided not to create one, return 0 and
2786 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and
2789 static int log_ref_setup(const char *refname, int force_create,
2790 int *logfd, struct strbuf *err)
2792 char *logfile = git_pathdup("logs/%s", refname);
2794 if (force_create || should_autocreate_reflog(refname)) {
2795 if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {
2796 if (errno == ENOENT)
2797 strbuf_addf(err, "unable to create directory for '%s': "
2798 "%s", logfile, strerror(errno));
2799 else if (errno == EISDIR)
2800 strbuf_addf(err, "there are still logs under '%s'",
2803 strbuf_addf(err, "unable to append to '%s': %s",
2804 logfile, strerror(errno));
2809 *logfd = open(logfile, O_APPEND | O_WRONLY, 0666);
2811 if (errno == ENOENT || errno == EISDIR) {
2813 * The logfile doesn't already exist,
2814 * but that is not an error; it only
2815 * means that we won't write log
2820 strbuf_addf(err, "unable to append to '%s': %s",
2821 logfile, strerror(errno));
2828 adjust_shared_perm(logfile);
2838 static int files_create_reflog(struct ref_store *ref_store,
2839 const char *refname, int force_create,
2844 /* Check validity (but we don't need the result): */
2845 files_downcast(ref_store, 0, "create_reflog");
2847 if (log_ref_setup(refname, force_create, &fd, err))
2856 static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
2857 const unsigned char *new_sha1,
2858 const char *committer, const char *msg)
2860 int msglen, written;
2861 unsigned maxlen, len;
2864 msglen = msg ? strlen(msg) : 0;
2865 maxlen = strlen(committer) + msglen + 100;
2866 logrec = xmalloc(maxlen);
2867 len = xsnprintf(logrec, maxlen, "%s %s %s\n",
2868 sha1_to_hex(old_sha1),
2869 sha1_to_hex(new_sha1),
2872 len += copy_reflog_msg(logrec + len - 1, msg) - 1;
2874 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;
2882 static int files_log_ref_write(const char *refname, const unsigned char *old_sha1,
2883 const unsigned char *new_sha1, const char *msg,
2884 int flags, struct strbuf *err)
2888 if (log_all_ref_updates == LOG_REFS_UNSET)
2889 log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;
2891 result = log_ref_setup(refname, flags & REF_FORCE_CREATE_REFLOG,
2899 result = log_ref_write_fd(logfd, old_sha1, new_sha1,
2900 git_committer_info(0), msg);
2902 struct strbuf sb = STRBUF_INIT;
2903 int save_errno = errno;
2905 strbuf_git_path(&sb, "logs/%s", refname);
2906 strbuf_addf(err, "unable to append to '%s': %s",
2907 sb.buf, strerror(save_errno));
2908 strbuf_release(&sb);
2913 struct strbuf sb = STRBUF_INIT;
2914 int save_errno = errno;
2916 strbuf_git_path(&sb, "logs/%s", refname);
2917 strbuf_addf(err, "unable to append to '%s': %s",
2918 sb.buf, strerror(save_errno));
2919 strbuf_release(&sb);
2926 * Write sha1 into the open lockfile, then close the lockfile. On
2927 * errors, rollback the lockfile, fill in *err and
2930 static int write_ref_to_lockfile(struct ref_lock *lock,
2931 const unsigned char *sha1, struct strbuf *err)
2933 static char term = '\n';
2937 o = parse_object(sha1);
2940 "trying to write ref '%s' with nonexistent object %s",
2941 lock->ref_name, sha1_to_hex(sha1));
2945 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2947 "trying to write non-commit object %s to branch '%s'",
2948 sha1_to_hex(sha1), lock->ref_name);
2952 fd = get_lock_file_fd(lock->lk);
2953 if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 ||
2954 write_in_full(fd, &term, 1) != 1 ||
2955 close_ref(lock) < 0) {
2957 "couldn't write '%s'", get_lock_file_path(lock->lk));
2965 * Commit a change to a loose reference that has already been written
2966 * to the loose reference lockfile. Also update the reflogs if
2967 * necessary, using the specified lockmsg (which can be NULL).
2969 static int commit_ref_update(struct files_ref_store *refs,
2970 struct ref_lock *lock,
2971 const unsigned char *sha1, const char *logmsg,
2974 files_assert_main_repository(refs, "commit_ref_update");
2976 clear_loose_ref_cache(refs);
2977 if (files_log_ref_write(lock->ref_name, lock->old_oid.hash, sha1,
2979 char *old_msg = strbuf_detach(err, NULL);
2980 strbuf_addf(err, "cannot update the ref '%s': %s",
2981 lock->ref_name, old_msg);
2987 if (strcmp(lock->ref_name, "HEAD") != 0) {
2989 * Special hack: If a branch is updated directly and HEAD
2990 * points to it (may happen on the remote side of a push
2991 * for example) then logically the HEAD reflog should be
2993 * A generic solution implies reverse symref information,
2994 * but finding all symrefs pointing to the given branch
2995 * would be rather costly for this rare event (the direct
2996 * update of a branch) to be worth it. So let's cheat and
2997 * check with HEAD only which should cover 99% of all usage
2998 * scenarios (even 100% of the default ones).
3000 unsigned char head_sha1[20];
3002 const char *head_ref;
3004 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
3005 head_sha1, &head_flag);
3006 if (head_ref && (head_flag & REF_ISSYMREF) &&
3007 !strcmp(head_ref, lock->ref_name)) {
3008 struct strbuf log_err = STRBUF_INIT;
3009 if (files_log_ref_write("HEAD", lock->old_oid.hash, sha1,
3010 logmsg, 0, &log_err)) {
3011 error("%s", log_err.buf);
3012 strbuf_release(&log_err);
3017 if (commit_ref(lock)) {
3018 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
3027 static int create_ref_symlink(struct ref_lock *lock, const char *target)
3030 #ifndef NO_SYMLINK_HEAD
3031 char *ref_path = get_locked_file_path(lock->lk);
3033 ret = symlink(target, ref_path);
3037 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
3042 static void update_symref_reflog(struct ref_lock *lock, const char *refname,
3043 const char *target, const char *logmsg)
3045 struct strbuf err = STRBUF_INIT;
3046 unsigned char new_sha1[20];
3047 if (logmsg && !read_ref(target, new_sha1) &&
3048 files_log_ref_write(refname, lock->old_oid.hash, new_sha1,
3050 error("%s", err.buf);
3051 strbuf_release(&err);
3055 static int create_symref_locked(struct ref_lock *lock, const char *refname,
3056 const char *target, const char *logmsg)
3058 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {
3059 update_symref_reflog(lock, refname, target, logmsg);
3063 if (!fdopen_lock_file(lock->lk, "w"))
3064 return error("unable to fdopen %s: %s",
3065 lock->lk->tempfile.filename.buf, strerror(errno));
3067 update_symref_reflog(lock, refname, target, logmsg);
3069 /* no error check; commit_ref will check ferror */
3070 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);
3071 if (commit_ref(lock) < 0)
3072 return error("unable to write symref for %s: %s", refname,
3077 static int files_create_symref(struct ref_store *ref_store,
3078 const char *refname, const char *target,
3081 struct files_ref_store *refs =
3082 files_downcast(ref_store, 0, "create_symref");
3083 struct strbuf err = STRBUF_INIT;
3084 struct ref_lock *lock;
3087 lock = lock_ref_sha1_basic(refs, refname, NULL,
3088 NULL, NULL, REF_NODEREF, NULL,
3091 error("%s", err.buf);
3092 strbuf_release(&err);
3096 ret = create_symref_locked(lock, refname, target, logmsg);
3101 int set_worktree_head_symref(const char *gitdir, const char *target, const char *logmsg)
3103 static struct lock_file head_lock;
3104 struct ref_lock *lock;
3105 struct strbuf head_path = STRBUF_INIT;
3106 const char *head_rel;
3109 strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir));
3110 if (hold_lock_file_for_update(&head_lock, head_path.buf,
3111 LOCK_NO_DEREF) < 0) {
3112 struct strbuf err = STRBUF_INIT;
3113 unable_to_lock_message(head_path.buf, errno, &err);
3114 error("%s", err.buf);
3115 strbuf_release(&err);
3116 strbuf_release(&head_path);
3120 /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for
3122 head_rel = remove_leading_path(head_path.buf,
3123 absolute_path(get_git_common_dir()));
3124 /* to make use of create_symref_locked(), initialize ref_lock */
3125 lock = xcalloc(1, sizeof(struct ref_lock));
3126 lock->lk = &head_lock;
3127 lock->ref_name = xstrdup(head_rel);
3129 ret = create_symref_locked(lock, head_rel, target, logmsg);
3131 unlock_ref(lock); /* will free lock */
3132 strbuf_release(&head_path);
3136 static int files_reflog_exists(struct ref_store *ref_store,
3137 const char *refname)
3139 struct strbuf sb = STRBUF_INIT;
3143 /* Check validity (but we don't need the result): */
3144 files_downcast(ref_store, 0, "reflog_exists");
3146 strbuf_git_path(&sb, "logs/%s", refname);
3147 ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode);
3148 strbuf_release(&sb);
3152 static int files_delete_reflog(struct ref_store *ref_store,
3153 const char *refname)
3155 struct strbuf sb = STRBUF_INIT;
3158 /* Check validity (but we don't need the result): */
3159 files_downcast(ref_store, 0, "delete_reflog");
3161 strbuf_git_path(&sb, "logs/%s", refname);
3162 ret = remove_path(sb.buf);
3163 strbuf_release(&sb);
3167 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3169 struct object_id ooid, noid;
3170 char *email_end, *message;
3171 unsigned long timestamp;
3173 const char *p = sb->buf;
3175 /* old SP new SP name <email> SP time TAB msg LF */
3176 if (!sb->len || sb->buf[sb->len - 1] != '\n' ||
3177 parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||
3178 parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||
3179 !(email_end = strchr(p, '>')) ||
3180 email_end[1] != ' ' ||
3181 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3182 !message || message[0] != ' ' ||
3183 (message[1] != '+' && message[1] != '-') ||
3184 !isdigit(message[2]) || !isdigit(message[3]) ||
3185 !isdigit(message[4]) || !isdigit(message[5]))
3186 return 0; /* corrupt? */
3187 email_end[1] = '\0';
3188 tz = strtol(message + 1, NULL, 10);
3189 if (message[6] != '\t')
3193 return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);
3196 static char *find_beginning_of_line(char *bob, char *scan)
3198 while (bob < scan && *(--scan) != '\n')
3199 ; /* keep scanning backwards */
3201 * Return either beginning of the buffer, or LF at the end of
3202 * the previous line.
3207 static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,
3208 const char *refname,
3209 each_reflog_ent_fn fn,
3212 struct strbuf sb = STRBUF_INIT;
3215 int ret = 0, at_tail = 1;
3217 /* Check validity (but we don't need the result): */
3218 files_downcast(ref_store, 0, "for_each_reflog_ent_reverse");
3220 strbuf_git_path(&sb, "logs/%s", refname);
3221 logfp = fopen(sb.buf, "r");
3222 strbuf_release(&sb);
3226 /* Jump to the end */
3227 if (fseek(logfp, 0, SEEK_END) < 0)
3228 return error("cannot seek back reflog for %s: %s",
3229 refname, strerror(errno));
3231 while (!ret && 0 < pos) {
3237 /* Fill next block from the end */
3238 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3239 if (fseek(logfp, pos - cnt, SEEK_SET))
3240 return error("cannot seek back reflog for %s: %s",
3241 refname, strerror(errno));
3242 nread = fread(buf, cnt, 1, logfp);
3244 return error("cannot read %d bytes from reflog for %s: %s",
3245 cnt, refname, strerror(errno));
3248 scanp = endp = buf + cnt;
3249 if (at_tail && scanp[-1] == '\n')
3250 /* Looking at the final LF at the end of the file */
3254 while (buf < scanp) {
3256 * terminating LF of the previous line, or the beginning
3261 bp = find_beginning_of_line(buf, scanp);
3265 * The newline is the end of the previous line,
3266 * so we know we have complete line starting
3267 * at (bp + 1). Prefix it onto any prior data
3268 * we collected for the line and process it.
3270 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3273 ret = show_one_reflog_ent(&sb, fn, cb_data);
3279 * We are at the start of the buffer, and the
3280 * start of the file; there is no previous
3281 * line, and we have everything for this one.
3282 * Process it, and we can end the loop.
3284 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3285 ret = show_one_reflog_ent(&sb, fn, cb_data);
3292 * We are at the start of the buffer, and there
3293 * is more file to read backwards. Which means
3294 * we are in the middle of a line. Note that we
3295 * may get here even if *bp was a newline; that
3296 * just means we are at the exact end of the
3297 * previous line, rather than some spot in the
3300 * Save away what we have to be combined with
3301 * the data from the next read.
3303 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3310 die("BUG: reverse reflog parser had leftover data");
3313 strbuf_release(&sb);
3317 static int files_for_each_reflog_ent(struct ref_store *ref_store,
3318 const char *refname,
3319 each_reflog_ent_fn fn, void *cb_data)
3322 struct strbuf sb = STRBUF_INIT;
3325 /* Check validity (but we don't need the result): */
3326 files_downcast(ref_store, 0, "for_each_reflog_ent");
3328 strbuf_git_path(&sb, "logs/%s", refname);
3329 logfp = fopen(sb.buf, "r");
3330 strbuf_release(&sb);
3334 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3335 ret = show_one_reflog_ent(&sb, fn, cb_data);
3337 strbuf_release(&sb);
3341 struct files_reflog_iterator {
3342 struct ref_iterator base;
3344 struct dir_iterator *dir_iterator;
3345 struct object_id oid;
3348 static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
3350 struct files_reflog_iterator *iter =
3351 (struct files_reflog_iterator *)ref_iterator;
3352 struct dir_iterator *diter = iter->dir_iterator;
3355 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
3358 if (!S_ISREG(diter->st.st_mode))
3360 if (diter->basename[0] == '.')
3362 if (ends_with(diter->basename, ".lock"))
3365 if (read_ref_full(diter->relative_path, 0,
3366 iter->oid.hash, &flags)) {
3367 error("bad ref for %s", diter->path.buf);
3371 iter->base.refname = diter->relative_path;
3372 iter->base.oid = &iter->oid;
3373 iter->base.flags = flags;
3377 iter->dir_iterator = NULL;
3378 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)
3383 static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,
3384 struct object_id *peeled)
3386 die("BUG: ref_iterator_peel() called for reflog_iterator");
3389 static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)
3391 struct files_reflog_iterator *iter =
3392 (struct files_reflog_iterator *)ref_iterator;
3395 if (iter->dir_iterator)
3396 ok = dir_iterator_abort(iter->dir_iterator);
3398 base_ref_iterator_free(ref_iterator);
3402 static struct ref_iterator_vtable files_reflog_iterator_vtable = {
3403 files_reflog_iterator_advance,
3404 files_reflog_iterator_peel,
3405 files_reflog_iterator_abort
3408 static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)
3410 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));
3411 struct ref_iterator *ref_iterator = &iter->base;
3412 struct strbuf sb = STRBUF_INIT;
3414 /* Check validity (but we don't need the result): */
3415 files_downcast(ref_store, 0, "reflog_iterator_begin");
3417 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);
3418 strbuf_git_path(&sb, "logs");
3419 iter->dir_iterator = dir_iterator_begin(sb.buf);
3420 strbuf_release(&sb);
3421 return ref_iterator;
3424 static int ref_update_reject_duplicates(struct string_list *refnames,
3427 int i, n = refnames->nr;
3431 for (i = 1; i < n; i++)
3432 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {
3434 "multiple updates for ref '%s' not allowed.",
3435 refnames->items[i].string);
3442 * If update is a direct update of head_ref (the reference pointed to
3443 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.
3445 static int split_head_update(struct ref_update *update,
3446 struct ref_transaction *transaction,
3447 const char *head_ref,
3448 struct string_list *affected_refnames,
3451 struct string_list_item *item;
3452 struct ref_update *new_update;
3454 if ((update->flags & REF_LOG_ONLY) ||
3455 (update->flags & REF_ISPRUNING) ||
3456 (update->flags & REF_UPDATE_VIA_HEAD))
3459 if (strcmp(update->refname, head_ref))
3463 * First make sure that HEAD is not already in the
3464 * transaction. This insertion is O(N) in the transaction
3465 * size, but it happens at most once per transaction.
3467 item = string_list_insert(affected_refnames, "HEAD");
3469 /* An entry already existed */
3471 "multiple updates for 'HEAD' (including one "
3472 "via its referent '%s') are not allowed",
3474 return TRANSACTION_NAME_CONFLICT;
3477 new_update = ref_transaction_add_update(
3478 transaction, "HEAD",
3479 update->flags | REF_LOG_ONLY | REF_NODEREF,
3480 update->new_sha1, update->old_sha1,
3483 item->util = new_update;
3489 * update is for a symref that points at referent and doesn't have
3490 * REF_NODEREF set. Split it into two updates:
3491 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set
3492 * - A new, separate update for the referent reference
3493 * Note that the new update will itself be subject to splitting when
3494 * the iteration gets to it.
3496 static int split_symref_update(struct files_ref_store *refs,
3497 struct ref_update *update,
3498 const char *referent,
3499 struct ref_transaction *transaction,
3500 struct string_list *affected_refnames,
3503 struct string_list_item *item;
3504 struct ref_update *new_update;
3505 unsigned int new_flags;
3508 * First make sure that referent is not already in the
3509 * transaction. This insertion is O(N) in the transaction
3510 * size, but it happens at most once per symref in a
3513 item = string_list_insert(affected_refnames, referent);
3515 /* An entry already existed */
3517 "multiple updates for '%s' (including one "
3518 "via symref '%s') are not allowed",
3519 referent, update->refname);
3520 return TRANSACTION_NAME_CONFLICT;
3523 new_flags = update->flags;
3524 if (!strcmp(update->refname, "HEAD")) {
3526 * Record that the new update came via HEAD, so that
3527 * when we process it, split_head_update() doesn't try
3528 * to add another reflog update for HEAD. Note that
3529 * this bit will be propagated if the new_update
3530 * itself needs to be split.
3532 new_flags |= REF_UPDATE_VIA_HEAD;
3535 new_update = ref_transaction_add_update(
3536 transaction, referent, new_flags,
3537 update->new_sha1, update->old_sha1,
3540 new_update->parent_update = update;
3543 * Change the symbolic ref update to log only. Also, it
3544 * doesn't need to check its old SHA-1 value, as that will be
3545 * done when new_update is processed.
3547 update->flags |= REF_LOG_ONLY | REF_NODEREF;
3548 update->flags &= ~REF_HAVE_OLD;
3550 item->util = new_update;
3556 * Return the refname under which update was originally requested.
3558 static const char *original_update_refname(struct ref_update *update)
3560 while (update->parent_update)
3561 update = update->parent_update;
3563 return update->refname;
3567 * Check whether the REF_HAVE_OLD and old_oid values stored in update
3568 * are consistent with oid, which is the reference's current value. If
3569 * everything is OK, return 0; otherwise, write an error message to
3570 * err and return -1.
3572 static int check_old_oid(struct ref_update *update, struct object_id *oid,
3575 if (!(update->flags & REF_HAVE_OLD) ||
3576 !hashcmp(oid->hash, update->old_sha1))
3579 if (is_null_sha1(update->old_sha1))
3580 strbuf_addf(err, "cannot lock ref '%s': "
3581 "reference already exists",
3582 original_update_refname(update));
3583 else if (is_null_oid(oid))
3584 strbuf_addf(err, "cannot lock ref '%s': "
3585 "reference is missing but expected %s",
3586 original_update_refname(update),
3587 sha1_to_hex(update->old_sha1));
3589 strbuf_addf(err, "cannot lock ref '%s': "
3590 "is at %s but expected %s",
3591 original_update_refname(update),
3593 sha1_to_hex(update->old_sha1));
3599 * Prepare for carrying out update:
3600 * - Lock the reference referred to by update.
3601 * - Read the reference under lock.
3602 * - Check that its old SHA-1 value (if specified) is correct, and in
3603 * any case record it in update->lock->old_oid for later use when
3604 * writing the reflog.
3605 * - If it is a symref update without REF_NODEREF, split it up into a
3606 * REF_LOG_ONLY update of the symref and add a separate update for
3607 * the referent to transaction.
3608 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY
3611 static int lock_ref_for_update(struct files_ref_store *refs,
3612 struct ref_update *update,
3613 struct ref_transaction *transaction,
3614 const char *head_ref,
3615 struct string_list *affected_refnames,
3618 struct strbuf referent = STRBUF_INIT;
3619 int mustexist = (update->flags & REF_HAVE_OLD) &&
3620 !is_null_sha1(update->old_sha1);
3622 struct ref_lock *lock;
3624 files_assert_main_repository(refs, "lock_ref_for_update");
3626 if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))
3627 update->flags |= REF_DELETING;
3630 ret = split_head_update(update, transaction, head_ref,
3631 affected_refnames, err);
3636 ret = lock_raw_ref(refs, update->refname, mustexist,
3637 affected_refnames, NULL,
3639 &update->type, err);
3643 reason = strbuf_detach(err, NULL);
3644 strbuf_addf(err, "cannot lock ref '%s': %s",
3645 original_update_refname(update), reason);
3650 update->backend_data = lock;
3652 if (update->type & REF_ISSYMREF) {
3653 if (update->flags & REF_NODEREF) {
3655 * We won't be reading the referent as part of
3656 * the transaction, so we have to read it here
3657 * to record and possibly check old_sha1:
3659 if (read_ref_full(referent.buf, 0,
3660 lock->old_oid.hash, NULL)) {
3661 if (update->flags & REF_HAVE_OLD) {
3662 strbuf_addf(err, "cannot lock ref '%s': "
3663 "error reading reference",
3664 original_update_refname(update));
3667 } else if (check_old_oid(update, &lock->old_oid, err)) {
3668 return TRANSACTION_GENERIC_ERROR;
3672 * Create a new update for the reference this
3673 * symref is pointing at. Also, we will record
3674 * and verify old_sha1 for this update as part
3675 * of processing the split-off update, so we
3676 * don't have to do it here.
3678 ret = split_symref_update(refs, update,
3679 referent.buf, transaction,
3680 affected_refnames, err);
3685 struct ref_update *parent_update;
3687 if (check_old_oid(update, &lock->old_oid, err))
3688 return TRANSACTION_GENERIC_ERROR;
3691 * If this update is happening indirectly because of a
3692 * symref update, record the old SHA-1 in the parent
3695 for (parent_update = update->parent_update;
3697 parent_update = parent_update->parent_update) {
3698 struct ref_lock *parent_lock = parent_update->backend_data;
3699 oidcpy(&parent_lock->old_oid, &lock->old_oid);
3703 if ((update->flags & REF_HAVE_NEW) &&
3704 !(update->flags & REF_DELETING) &&
3705 !(update->flags & REF_LOG_ONLY)) {
3706 if (!(update->type & REF_ISSYMREF) &&
3707 !hashcmp(lock->old_oid.hash, update->new_sha1)) {
3709 * The reference already has the desired
3710 * value, so we don't need to write it.
3712 } else if (write_ref_to_lockfile(lock, update->new_sha1,
3714 char *write_err = strbuf_detach(err, NULL);
3717 * The lock was freed upon failure of
3718 * write_ref_to_lockfile():
3720 update->backend_data = NULL;
3722 "cannot update ref '%s': %s",
3723 update->refname, write_err);
3725 return TRANSACTION_GENERIC_ERROR;
3727 update->flags |= REF_NEEDS_COMMIT;
3730 if (!(update->flags & REF_NEEDS_COMMIT)) {
3732 * We didn't call write_ref_to_lockfile(), so
3733 * the lockfile is still open. Close it to
3734 * free up the file descriptor:
3736 if (close_ref(lock)) {
3737 strbuf_addf(err, "couldn't close '%s.lock'",
3739 return TRANSACTION_GENERIC_ERROR;
3745 static int files_transaction_commit(struct ref_store *ref_store,
3746 struct ref_transaction *transaction,
3749 struct files_ref_store *refs =
3750 files_downcast(ref_store, 0, "ref_transaction_commit");
3752 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;
3753 struct string_list_item *ref_to_delete;
3754 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
3755 char *head_ref = NULL;
3757 struct object_id head_oid;
3758 struct strbuf sb = STRBUF_INIT;
3762 if (transaction->state != REF_TRANSACTION_OPEN)
3763 die("BUG: commit called for transaction that is not open");
3765 if (!transaction->nr) {
3766 transaction->state = REF_TRANSACTION_CLOSED;
3771 * Fail if a refname appears more than once in the
3772 * transaction. (If we end up splitting up any updates using
3773 * split_symref_update() or split_head_update(), those
3774 * functions will check that the new updates don't have the
3775 * same refname as any existing ones.)
3777 for (i = 0; i < transaction->nr; i++) {
3778 struct ref_update *update = transaction->updates[i];
3779 struct string_list_item *item =
3780 string_list_append(&affected_refnames, update->refname);
3783 * We store a pointer to update in item->util, but at
3784 * the moment we never use the value of this field
3785 * except to check whether it is non-NULL.
3787 item->util = update;
3789 string_list_sort(&affected_refnames);
3790 if (ref_update_reject_duplicates(&affected_refnames, err)) {
3791 ret = TRANSACTION_GENERIC_ERROR;
3796 * Special hack: If a branch is updated directly and HEAD
3797 * points to it (may happen on the remote side of a push
3798 * for example) then logically the HEAD reflog should be
3801 * A generic solution would require reverse symref lookups,
3802 * but finding all symrefs pointing to a given branch would be
3803 * rather costly for this rare event (the direct update of a
3804 * branch) to be worth it. So let's cheat and check with HEAD
3805 * only, which should cover 99% of all usage scenarios (even
3806 * 100% of the default ones).
3808 * So if HEAD is a symbolic reference, then record the name of
3809 * the reference that it points to. If we see an update of
3810 * head_ref within the transaction, then split_head_update()
3811 * arranges for the reflog of HEAD to be updated, too.
3813 head_ref = resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,
3814 head_oid.hash, &head_type);
3816 if (head_ref && !(head_type & REF_ISSYMREF)) {
3822 * Acquire all locks, verify old values if provided, check
3823 * that new values are valid, and write new values to the
3824 * lockfiles, ready to be activated. Only keep one lockfile
3825 * open at a time to avoid running out of file descriptors.
3827 for (i = 0; i < transaction->nr; i++) {
3828 struct ref_update *update = transaction->updates[i];
3830 ret = lock_ref_for_update(refs, update, transaction,
3831 head_ref, &affected_refnames, err);
3836 /* Perform updates first so live commits remain referenced */
3837 for (i = 0; i < transaction->nr; i++) {
3838 struct ref_update *update = transaction->updates[i];
3839 struct ref_lock *lock = update->backend_data;
3841 if (update->flags & REF_NEEDS_COMMIT ||
3842 update->flags & REF_LOG_ONLY) {
3843 if (files_log_ref_write(lock->ref_name,
3846 update->msg, update->flags,
3848 char *old_msg = strbuf_detach(err, NULL);
3850 strbuf_addf(err, "cannot update the ref '%s': %s",
3851 lock->ref_name, old_msg);
3854 update->backend_data = NULL;
3855 ret = TRANSACTION_GENERIC_ERROR;
3859 if (update->flags & REF_NEEDS_COMMIT) {
3860 clear_loose_ref_cache(refs);
3861 if (commit_ref(lock)) {
3862 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
3864 update->backend_data = NULL;
3865 ret = TRANSACTION_GENERIC_ERROR;
3870 /* Perform deletes now that updates are safely completed */
3871 for (i = 0; i < transaction->nr; i++) {
3872 struct ref_update *update = transaction->updates[i];
3873 struct ref_lock *lock = update->backend_data;
3875 if (update->flags & REF_DELETING &&
3876 !(update->flags & REF_LOG_ONLY)) {
3877 if (!(update->type & REF_ISPACKED) ||
3878 update->type & REF_ISSYMREF) {
3879 /* It is a loose reference. */
3881 strbuf_git_path(&sb, "%s", lock->ref_name);
3882 if (unlink_or_msg(sb.buf, err)) {
3883 ret = TRANSACTION_GENERIC_ERROR;
3886 update->flags |= REF_DELETED_LOOSE;
3889 if (!(update->flags & REF_ISPRUNING))
3890 string_list_append(&refs_to_delete,
3895 if (repack_without_refs(refs, &refs_to_delete, err)) {
3896 ret = TRANSACTION_GENERIC_ERROR;
3900 /* Delete the reflogs of any references that were deleted: */
3901 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
3903 strbuf_git_path(&sb, "logs/%s", ref_to_delete->string);
3904 if (!unlink_or_warn(sb.buf))
3905 try_remove_empty_parents(ref_to_delete->string,
3906 REMOVE_EMPTY_PARENTS_REFLOG);
3909 clear_loose_ref_cache(refs);
3912 strbuf_release(&sb);
3913 transaction->state = REF_TRANSACTION_CLOSED;
3915 for (i = 0; i < transaction->nr; i++) {
3916 struct ref_update *update = transaction->updates[i];
3917 struct ref_lock *lock = update->backend_data;
3922 if (update->flags & REF_DELETED_LOOSE) {
3924 * The loose reference was deleted. Delete any
3925 * empty parent directories. (Note that this
3926 * can only work because we have already
3927 * removed the lockfile.)
3929 try_remove_empty_parents(update->refname,
3930 REMOVE_EMPTY_PARENTS_REF);
3934 string_list_clear(&refs_to_delete, 0);
3936 string_list_clear(&affected_refnames, 0);
3941 static int ref_present(const char *refname,
3942 const struct object_id *oid, int flags, void *cb_data)
3944 struct string_list *affected_refnames = cb_data;
3946 return string_list_has_string(affected_refnames, refname);
3949 static int files_initial_transaction_commit(struct ref_store *ref_store,
3950 struct ref_transaction *transaction,
3953 struct files_ref_store *refs =
3954 files_downcast(ref_store, 0, "initial_ref_transaction_commit");
3956 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
3960 if (transaction->state != REF_TRANSACTION_OPEN)
3961 die("BUG: commit called for transaction that is not open");
3963 /* Fail if a refname appears more than once in the transaction: */
3964 for (i = 0; i < transaction->nr; i++)
3965 string_list_append(&affected_refnames,
3966 transaction->updates[i]->refname);
3967 string_list_sort(&affected_refnames);
3968 if (ref_update_reject_duplicates(&affected_refnames, err)) {
3969 ret = TRANSACTION_GENERIC_ERROR;
3974 * It's really undefined to call this function in an active
3975 * repository or when there are existing references: we are
3976 * only locking and changing packed-refs, so (1) any
3977 * simultaneous processes might try to change a reference at
3978 * the same time we do, and (2) any existing loose versions of
3979 * the references that we are setting would have precedence
3980 * over our values. But some remote helpers create the remote
3981 * "HEAD" and "master" branches before calling this function,
3982 * so here we really only check that none of the references
3983 * that we are creating already exists.
3985 if (for_each_rawref(ref_present, &affected_refnames))
3986 die("BUG: initial ref transaction called with existing refs");
3988 for (i = 0; i < transaction->nr; i++) {
3989 struct ref_update *update = transaction->updates[i];
3991 if ((update->flags & REF_HAVE_OLD) &&
3992 !is_null_sha1(update->old_sha1))
3993 die("BUG: initial ref transaction with old_sha1 set");
3994 if (verify_refname_available(update->refname,
3995 &affected_refnames, NULL,
3997 ret = TRANSACTION_NAME_CONFLICT;
4002 if (lock_packed_refs(refs, 0)) {
4003 strbuf_addf(err, "unable to lock packed-refs file: %s",
4005 ret = TRANSACTION_GENERIC_ERROR;
4009 for (i = 0; i < transaction->nr; i++) {
4010 struct ref_update *update = transaction->updates[i];
4012 if ((update->flags & REF_HAVE_NEW) &&
4013 !is_null_sha1(update->new_sha1))
4014 add_packed_ref(refs, update->refname, update->new_sha1);
4017 if (commit_packed_refs(refs)) {
4018 strbuf_addf(err, "unable to commit packed-refs file: %s",
4020 ret = TRANSACTION_GENERIC_ERROR;
4025 transaction->state = REF_TRANSACTION_CLOSED;
4026 string_list_clear(&affected_refnames, 0);
4030 struct expire_reflog_cb {
4032 reflog_expiry_should_prune_fn *should_prune_fn;
4035 struct object_id last_kept_oid;
4038 static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
4039 const char *email, unsigned long timestamp, int tz,
4040 const char *message, void *cb_data)
4042 struct expire_reflog_cb *cb = cb_data;
4043 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
4045 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
4046 ooid = &cb->last_kept_oid;
4048 if ((*cb->should_prune_fn)(ooid->hash, noid->hash, email, timestamp, tz,
4049 message, policy_cb)) {
4051 printf("would prune %s", message);
4052 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
4053 printf("prune %s", message);
4056 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",
4057 oid_to_hex(ooid), oid_to_hex(noid),
4058 email, timestamp, tz, message);
4059 oidcpy(&cb->last_kept_oid, noid);
4061 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
4062 printf("keep %s", message);
4067 static int files_reflog_expire(struct ref_store *ref_store,
4068 const char *refname, const unsigned char *sha1,
4070 reflog_expiry_prepare_fn prepare_fn,
4071 reflog_expiry_should_prune_fn should_prune_fn,
4072 reflog_expiry_cleanup_fn cleanup_fn,
4073 void *policy_cb_data)
4075 struct files_ref_store *refs =
4076 files_downcast(ref_store, 0, "reflog_expire");
4077 static struct lock_file reflog_lock;
4078 struct expire_reflog_cb cb;
4079 struct ref_lock *lock;
4083 struct strbuf err = STRBUF_INIT;
4085 memset(&cb, 0, sizeof(cb));
4087 cb.policy_cb = policy_cb_data;
4088 cb.should_prune_fn = should_prune_fn;
4091 * The reflog file is locked by holding the lock on the
4092 * reference itself, plus we might need to update the
4093 * reference if --updateref was specified:
4095 lock = lock_ref_sha1_basic(refs, refname, sha1,
4096 NULL, NULL, REF_NODEREF,
4099 error("cannot lock ref '%s': %s", refname, err.buf);
4100 strbuf_release(&err);
4103 if (!reflog_exists(refname)) {
4108 log_file = git_pathdup("logs/%s", refname);
4109 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
4111 * Even though holding $GIT_DIR/logs/$reflog.lock has
4112 * no locking implications, we use the lock_file
4113 * machinery here anyway because it does a lot of the
4114 * work we need, including cleaning up if the program
4115 * exits unexpectedly.
4117 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
4118 struct strbuf err = STRBUF_INIT;
4119 unable_to_lock_message(log_file, errno, &err);
4120 error("%s", err.buf);
4121 strbuf_release(&err);
4124 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
4126 error("cannot fdopen %s (%s)",
4127 get_lock_file_path(&reflog_lock), strerror(errno));
4132 (*prepare_fn)(refname, sha1, cb.policy_cb);
4133 for_each_reflog_ent(refname, expire_reflog_ent, &cb);
4134 (*cleanup_fn)(cb.policy_cb);
4136 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
4138 * It doesn't make sense to adjust a reference pointed
4139 * to by a symbolic ref based on expiring entries in
4140 * the symbolic reference's reflog. Nor can we update
4141 * a reference if there are no remaining reflog
4144 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
4145 !(type & REF_ISSYMREF) &&
4146 !is_null_oid(&cb.last_kept_oid);
4148 if (close_lock_file(&reflog_lock)) {
4149 status |= error("couldn't write %s: %s", log_file,
4151 } else if (update &&
4152 (write_in_full(get_lock_file_fd(lock->lk),
4153 oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||
4154 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||
4155 close_ref(lock) < 0)) {
4156 status |= error("couldn't write %s",
4157 get_lock_file_path(lock->lk));
4158 rollback_lock_file(&reflog_lock);
4159 } else if (commit_lock_file(&reflog_lock)) {
4160 status |= error("unable to write reflog '%s' (%s)",
4161 log_file, strerror(errno));
4162 } else if (update && commit_ref(lock)) {
4163 status |= error("couldn't set %s", lock->ref_name);
4171 rollback_lock_file(&reflog_lock);
4177 static int files_init_db(struct ref_store *ref_store, struct strbuf *err)
4179 struct strbuf sb = STRBUF_INIT;
4181 /* Check validity (but we don't need the result): */
4182 files_downcast(ref_store, 0, "init_db");
4185 * Create .git/refs/{heads,tags}
4187 strbuf_git_path(&sb, "refs/heads");
4188 safe_create_dir(sb.buf, 1);
4191 strbuf_git_path(&sb, "refs/tags");
4192 safe_create_dir(sb.buf, 1);
4194 strbuf_release(&sb);
4198 struct ref_storage_be refs_be_files = {
4201 files_ref_store_create,
4203 files_transaction_commit,
4204 files_initial_transaction_commit,
4208 files_create_symref,
4212 files_ref_iterator_begin,
4214 files_verify_refname_available,
4216 files_reflog_iterator_begin,
4217 files_for_each_reflog_ent,
4218 files_for_each_reflog_ent_reverse,
4219 files_reflog_exists,
4220 files_create_reflog,
4221 files_delete_reflog,