3 #include "refs-internal.h"
5 #include "../iterator.h"
6 #include "../dir-iterator.h"
7 #include "../lockfile.h"
14 struct object_id old_oid;
18 * Return true if refname, which has the specified oid and flags, can
19 * be resolved to an object in the database. If the referred-to object
20 * does not exist, emit a warning and return false.
22 static int ref_resolves_to_object(const char *refname,
23 const struct object_id *oid,
26 if (flags & REF_ISBROKEN)
28 if (!has_sha1_file(oid->hash)) {
29 error("%s does not point to a valid object!", refname);
36 * Return true if the reference described by entry can be resolved to
37 * an object in the database; otherwise, emit a warning and return
40 static int entry_resolves_to_object(struct ref_entry *entry)
42 return ref_resolves_to_object(entry->name,
43 &entry->u.value.oid, entry->flag);
46 struct packed_ref_cache {
47 struct ref_cache *cache;
50 * Count of references to the data structure in this instance,
51 * including the pointer from files_ref_store::packed if any.
52 * The data will not be freed as long as the reference count
55 unsigned int referrers;
58 * Iff the packed-refs file associated with this instance is
59 * currently locked for writing, this points at the associated
60 * lock (which is owned by somebody else). The referrer count
61 * is also incremented when the file is locked and decremented
62 * when it is unlocked.
64 struct lock_file *lock;
66 /* The metadata from when this packed-refs cache was read */
67 struct stat_validity validity;
71 * Future: need to be in "struct repository"
72 * when doing a full libification.
74 struct files_ref_store {
75 struct ref_store base;
76 unsigned int store_flags;
80 char *packed_refs_path;
82 struct ref_cache *loose;
83 struct packed_ref_cache *packed;
86 /* Lock used for the main packed-refs file: */
87 static struct lock_file packlock;
90 * Increment the reference count of *packed_refs.
92 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
94 packed_refs->referrers++;
98 * Decrease the reference count of *packed_refs. If it goes to zero,
99 * free *packed_refs and return true; otherwise return false.
101 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
103 if (!--packed_refs->referrers) {
104 free_ref_cache(packed_refs->cache);
105 stat_validity_clear(&packed_refs->validity);
113 static void clear_packed_ref_cache(struct files_ref_store *refs)
116 struct packed_ref_cache *packed_refs = refs->packed;
118 if (packed_refs->lock)
119 die("internal error: packed-ref cache cleared while locked");
121 release_packed_ref_cache(packed_refs);
125 static void clear_loose_ref_cache(struct files_ref_store *refs)
128 free_ref_cache(refs->loose);
134 * Create a new submodule ref cache and add it to the internal
137 static struct ref_store *files_ref_store_create(const char *gitdir,
140 struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
141 struct ref_store *ref_store = (struct ref_store *)refs;
142 struct strbuf sb = STRBUF_INIT;
144 base_ref_store_init(ref_store, &refs_be_files);
145 refs->store_flags = flags;
147 refs->gitdir = xstrdup(gitdir);
148 get_common_dir_noenv(&sb, gitdir);
149 refs->gitcommondir = strbuf_detach(&sb, NULL);
150 strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir);
151 refs->packed_refs_path = strbuf_detach(&sb, NULL);
157 * Die if refs is not the main ref store. caller is used in any
158 * necessary error messages.
160 static void files_assert_main_repository(struct files_ref_store *refs,
163 if (refs->store_flags & REF_STORE_MAIN)
166 die("BUG: operation %s only allowed for main ref store", caller);
170 * Downcast ref_store to files_ref_store. Die if ref_store is not a
171 * files_ref_store. required_flags is compared with ref_store's
172 * store_flags to ensure the ref_store has all required capabilities.
173 * "caller" is used in any necessary error messages.
175 static struct files_ref_store *files_downcast(struct ref_store *ref_store,
176 unsigned int required_flags,
179 struct files_ref_store *refs;
181 if (ref_store->be != &refs_be_files)
182 die("BUG: ref_store is type \"%s\" not \"files\" in %s",
183 ref_store->be->name, caller);
185 refs = (struct files_ref_store *)ref_store;
187 if ((refs->store_flags & required_flags) != required_flags)
188 die("BUG: operation %s requires abilities 0x%x, but only have 0x%x",
189 caller, required_flags, refs->store_flags);
194 /* The length of a peeled reference line in packed-refs, including EOL: */
195 #define PEELED_LINE_LENGTH 42
198 * The packed-refs header line that we write out. Perhaps other
199 * traits will be added later. The trailing space is required.
201 static const char PACKED_REFS_HEADER[] =
202 "# pack-refs with: peeled fully-peeled \n";
205 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
206 * Return a pointer to the refname within the line (null-terminated),
207 * or NULL if there was a problem.
209 static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1)
214 * 42: the answer to everything.
216 * In this case, it happens to be the answer to
217 * 40 (length of sha1 hex representation)
218 * +1 (space in between hex and name)
219 * +1 (newline at the end of the line)
224 if (get_sha1_hex(line->buf, sha1) < 0)
226 if (!isspace(line->buf[40]))
229 ref = line->buf + 41;
233 if (line->buf[line->len - 1] != '\n')
235 line->buf[--line->len] = 0;
241 * Read f, which is a packed-refs file, into dir.
243 * A comment line of the form "# pack-refs with: " may contain zero or
244 * more traits. We interpret the traits as follows:
248 * Probably no references are peeled. But if the file contains a
249 * peeled value for a reference, we will use it.
253 * References under "refs/tags/", if they *can* be peeled, *are*
254 * peeled in this file. References outside of "refs/tags/" are
255 * probably not peeled even if they could have been, but if we find
256 * a peeled value for such a reference we will use it.
260 * All references in the file that can be peeled are peeled.
261 * Inversely (and this is more important), any references in the
262 * file for which no peeled value is recorded is not peelable. This
263 * trait should typically be written alongside "peeled" for
264 * compatibility with older clients, but we do not require it
265 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
267 static void read_packed_refs(FILE *f, struct ref_dir *dir)
269 struct ref_entry *last = NULL;
270 struct strbuf line = STRBUF_INIT;
271 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
273 while (strbuf_getwholeline(&line, f, '\n') != EOF) {
274 unsigned char sha1[20];
278 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
279 if (strstr(traits, " fully-peeled "))
280 peeled = PEELED_FULLY;
281 else if (strstr(traits, " peeled "))
282 peeled = PEELED_TAGS;
283 /* perhaps other traits later as well */
287 refname = parse_ref_line(&line, sha1);
289 int flag = REF_ISPACKED;
291 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
292 if (!refname_is_safe(refname))
293 die("packed refname is dangerous: %s", refname);
295 flag |= REF_BAD_NAME | REF_ISBROKEN;
297 last = create_ref_entry(refname, sha1, flag, 0);
298 if (peeled == PEELED_FULLY ||
299 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
300 last->flag |= REF_KNOWS_PEELED;
301 add_ref_entry(dir, last);
305 line.buf[0] == '^' &&
306 line.len == PEELED_LINE_LENGTH &&
307 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&
308 !get_sha1_hex(line.buf + 1, sha1)) {
309 hashcpy(last->u.value.peeled.hash, sha1);
311 * Regardless of what the file header said,
312 * we definitely know the value of *this*
315 last->flag |= REF_KNOWS_PEELED;
319 strbuf_release(&line);
322 static const char *files_packed_refs_path(struct files_ref_store *refs)
324 return refs->packed_refs_path;
327 static void files_reflog_path(struct files_ref_store *refs,
333 * FIXME: of course this is wrong in multi worktree
334 * setting. To be fixed real soon.
336 strbuf_addf(sb, "%s/logs", refs->gitcommondir);
340 switch (ref_type(refname)) {
341 case REF_TYPE_PER_WORKTREE:
342 case REF_TYPE_PSEUDOREF:
343 strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname);
345 case REF_TYPE_NORMAL:
346 strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname);
349 die("BUG: unknown ref type %d of ref %s",
350 ref_type(refname), refname);
354 static void files_ref_path(struct files_ref_store *refs,
358 switch (ref_type(refname)) {
359 case REF_TYPE_PER_WORKTREE:
360 case REF_TYPE_PSEUDOREF:
361 strbuf_addf(sb, "%s/%s", refs->gitdir, refname);
363 case REF_TYPE_NORMAL:
364 strbuf_addf(sb, "%s/%s", refs->gitcommondir, refname);
367 die("BUG: unknown ref type %d of ref %s",
368 ref_type(refname), refname);
373 * Get the packed_ref_cache for the specified files_ref_store,
374 * creating it if necessary.
376 static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)
378 const char *packed_refs_file = files_packed_refs_path(refs);
381 !stat_validity_check(&refs->packed->validity, packed_refs_file))
382 clear_packed_ref_cache(refs);
387 refs->packed = xcalloc(1, sizeof(*refs->packed));
388 acquire_packed_ref_cache(refs->packed);
389 refs->packed->cache = create_ref_cache(&refs->base, NULL);
390 refs->packed->cache->root->flag &= ~REF_INCOMPLETE;
391 f = fopen(packed_refs_file, "r");
393 stat_validity_update(&refs->packed->validity, fileno(f));
394 read_packed_refs(f, get_ref_dir(refs->packed->cache->root));
401 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
403 return get_ref_dir(packed_ref_cache->cache->root);
406 static struct ref_dir *get_packed_refs(struct files_ref_store *refs)
408 return get_packed_ref_dir(get_packed_ref_cache(refs));
412 * Add a reference to the in-memory packed reference cache. This may
413 * only be called while the packed-refs file is locked (see
414 * lock_packed_refs()). To actually write the packed-refs file, call
415 * commit_packed_refs().
417 static void add_packed_ref(struct files_ref_store *refs,
418 const char *refname, const unsigned char *sha1)
420 struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs);
422 if (!packed_ref_cache->lock)
423 die("internal error: packed refs not locked");
424 add_ref_entry(get_packed_ref_dir(packed_ref_cache),
425 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
429 * Read the loose references from the namespace dirname into dir
430 * (without recursing). dirname must end with '/'. dir must be the
431 * directory entry corresponding to dirname.
433 static void loose_fill_ref_dir(struct ref_store *ref_store,
434 struct ref_dir *dir, const char *dirname)
436 struct files_ref_store *refs =
437 files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir");
440 int dirnamelen = strlen(dirname);
441 struct strbuf refname;
442 struct strbuf path = STRBUF_INIT;
445 files_ref_path(refs, &path, dirname);
446 path_baselen = path.len;
448 d = opendir(path.buf);
450 strbuf_release(&path);
454 strbuf_init(&refname, dirnamelen + 257);
455 strbuf_add(&refname, dirname, dirnamelen);
457 while ((de = readdir(d)) != NULL) {
458 unsigned char sha1[20];
462 if (de->d_name[0] == '.')
464 if (ends_with(de->d_name, ".lock"))
466 strbuf_addstr(&refname, de->d_name);
467 strbuf_addstr(&path, de->d_name);
468 if (stat(path.buf, &st) < 0) {
469 ; /* silently ignore */
470 } else if (S_ISDIR(st.st_mode)) {
471 strbuf_addch(&refname, '/');
472 add_entry_to_dir(dir,
473 create_dir_entry(dir->cache, refname.buf,
476 if (!refs_resolve_ref_unsafe(&refs->base,
481 flag |= REF_ISBROKEN;
482 } else if (is_null_sha1(sha1)) {
484 * It is so astronomically unlikely
485 * that NULL_SHA1 is the SHA-1 of an
486 * actual object that we consider its
487 * appearance in a loose reference
488 * file to be repo corruption
489 * (probably due to a software bug).
491 flag |= REF_ISBROKEN;
494 if (check_refname_format(refname.buf,
495 REFNAME_ALLOW_ONELEVEL)) {
496 if (!refname_is_safe(refname.buf))
497 die("loose refname is dangerous: %s", refname.buf);
499 flag |= REF_BAD_NAME | REF_ISBROKEN;
501 add_entry_to_dir(dir,
502 create_ref_entry(refname.buf, sha1, flag, 0));
504 strbuf_setlen(&refname, dirnamelen);
505 strbuf_setlen(&path, path_baselen);
507 strbuf_release(&refname);
508 strbuf_release(&path);
512 * Manually add refs/bisect, which, being per-worktree, might
513 * not appear in the directory listing for refs/ in the main
516 if (!strcmp(dirname, "refs/")) {
517 int pos = search_ref_dir(dir, "refs/bisect/", 12);
520 struct ref_entry *child_entry = create_dir_entry(
521 dir->cache, "refs/bisect/", 12, 1);
522 add_entry_to_dir(dir, child_entry);
527 static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs)
531 * Mark the top-level directory complete because we
532 * are about to read the only subdirectory that can
535 refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir);
537 /* We're going to fill the top level ourselves: */
538 refs->loose->root->flag &= ~REF_INCOMPLETE;
541 * Add an incomplete entry for "refs/" (to be filled
544 add_entry_to_dir(get_ref_dir(refs->loose->root),
545 create_dir_entry(refs->loose, "refs/", 5, 1));
550 static struct ref_dir *get_loose_ref_dir(struct files_ref_store *refs)
552 return get_ref_dir(get_loose_ref_cache(refs)->root);
556 * Return the ref_entry for the given refname from the packed
557 * references. If it does not exist, return NULL.
559 static struct ref_entry *get_packed_ref(struct files_ref_store *refs,
562 return find_ref_entry(get_packed_refs(refs), refname);
566 * A loose ref file doesn't exist; check for a packed ref.
568 static int resolve_packed_ref(struct files_ref_store *refs,
570 unsigned char *sha1, unsigned int *flags)
572 struct ref_entry *entry;
575 * The loose reference file does not exist; check for a packed
578 entry = get_packed_ref(refs, refname);
580 hashcpy(sha1, entry->u.value.oid.hash);
581 *flags |= REF_ISPACKED;
584 /* refname is not a packed reference. */
588 static int files_read_raw_ref(struct ref_store *ref_store,
589 const char *refname, unsigned char *sha1,
590 struct strbuf *referent, unsigned int *type)
592 struct files_ref_store *refs =
593 files_downcast(ref_store, REF_STORE_READ, "read_raw_ref");
594 struct strbuf sb_contents = STRBUF_INIT;
595 struct strbuf sb_path = STRBUF_INIT;
602 int remaining_retries = 3;
605 strbuf_reset(&sb_path);
607 files_ref_path(refs, &sb_path, refname);
613 * We might have to loop back here to avoid a race
614 * condition: first we lstat() the file, then we try
615 * to read it as a link or as a file. But if somebody
616 * changes the type of the file (file <-> directory
617 * <-> symlink) between the lstat() and reading, then
618 * we don't want to report that as an error but rather
619 * try again starting with the lstat().
621 * We'll keep a count of the retries, though, just to avoid
622 * any confusing situation sending us into an infinite loop.
625 if (remaining_retries-- <= 0)
628 if (lstat(path, &st) < 0) {
631 if (resolve_packed_ref(refs, refname, sha1, type)) {
639 /* Follow "normalized" - ie "refs/.." symlinks by hand */
640 if (S_ISLNK(st.st_mode)) {
641 strbuf_reset(&sb_contents);
642 if (strbuf_readlink(&sb_contents, path, 0) < 0) {
643 if (errno == ENOENT || errno == EINVAL)
644 /* inconsistent with lstat; retry */
649 if (starts_with(sb_contents.buf, "refs/") &&
650 !check_refname_format(sb_contents.buf, 0)) {
651 strbuf_swap(&sb_contents, referent);
652 *type |= REF_ISSYMREF;
657 * It doesn't look like a refname; fall through to just
658 * treating it like a non-symlink, and reading whatever it
663 /* Is it a directory? */
664 if (S_ISDIR(st.st_mode)) {
666 * Even though there is a directory where the loose
667 * ref is supposed to be, there could still be a
670 if (resolve_packed_ref(refs, refname, sha1, type)) {
679 * Anything else, just open it and try to use it as
682 fd = open(path, O_RDONLY);
684 if (errno == ENOENT && !S_ISLNK(st.st_mode))
685 /* inconsistent with lstat; retry */
690 strbuf_reset(&sb_contents);
691 if (strbuf_read(&sb_contents, fd, 256) < 0) {
692 int save_errno = errno;
698 strbuf_rtrim(&sb_contents);
699 buf = sb_contents.buf;
700 if (starts_with(buf, "ref:")) {
702 while (isspace(*buf))
705 strbuf_reset(referent);
706 strbuf_addstr(referent, buf);
707 *type |= REF_ISSYMREF;
713 * Please note that FETCH_HEAD has additional
714 * data after the sha.
716 if (get_sha1_hex(buf, sha1) ||
717 (buf[40] != '\0' && !isspace(buf[40]))) {
718 *type |= REF_ISBROKEN;
727 strbuf_release(&sb_path);
728 strbuf_release(&sb_contents);
733 static void unlock_ref(struct ref_lock *lock)
735 /* Do not free lock->lk -- atexit() still looks at them */
737 rollback_lock_file(lock->lk);
738 free(lock->ref_name);
743 * Lock refname, without following symrefs, and set *lock_p to point
744 * at a newly-allocated lock object. Fill in lock->old_oid, referent,
745 * and type similarly to read_raw_ref().
747 * The caller must verify that refname is a "safe" reference name (in
748 * the sense of refname_is_safe()) before calling this function.
750 * If the reference doesn't already exist, verify that refname doesn't
751 * have a D/F conflict with any existing references. extras and skip
752 * are passed to refs_verify_refname_available() for this check.
754 * If mustexist is not set and the reference is not found or is
755 * broken, lock the reference anyway but clear sha1.
757 * Return 0 on success. On failure, write an error message to err and
758 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
760 * Implementation note: This function is basically
765 * but it includes a lot more code to
766 * - Deal with possible races with other processes
767 * - Avoid calling refs_verify_refname_available() when it can be
768 * avoided, namely if we were successfully able to read the ref
769 * - Generate informative error messages in the case of failure
771 static int lock_raw_ref(struct files_ref_store *refs,
772 const char *refname, int mustexist,
773 const struct string_list *extras,
774 const struct string_list *skip,
775 struct ref_lock **lock_p,
776 struct strbuf *referent,
780 struct ref_lock *lock;
781 struct strbuf ref_file = STRBUF_INIT;
782 int attempts_remaining = 3;
783 int ret = TRANSACTION_GENERIC_ERROR;
786 files_assert_main_repository(refs, "lock_raw_ref");
790 /* First lock the file so it can't change out from under us. */
792 *lock_p = lock = xcalloc(1, sizeof(*lock));
794 lock->ref_name = xstrdup(refname);
795 files_ref_path(refs, &ref_file, refname);
798 switch (safe_create_leading_directories(ref_file.buf)) {
803 * Suppose refname is "refs/foo/bar". We just failed
804 * to create the containing directory, "refs/foo",
805 * because there was a non-directory in the way. This
806 * indicates a D/F conflict, probably because of
807 * another reference such as "refs/foo". There is no
808 * reason to expect this error to be transitory.
810 if (refs_verify_refname_available(&refs->base, refname,
811 extras, skip, err)) {
814 * To the user the relevant error is
815 * that the "mustexist" reference is
819 strbuf_addf(err, "unable to resolve reference '%s'",
823 * The error message set by
824 * refs_verify_refname_available() is
827 ret = TRANSACTION_NAME_CONFLICT;
831 * The file that is in the way isn't a loose
832 * reference. Report it as a low-level
835 strbuf_addf(err, "unable to create lock file %s.lock; "
836 "non-directory in the way",
841 /* Maybe another process was tidying up. Try again. */
842 if (--attempts_remaining > 0)
846 strbuf_addf(err, "unable to create directory for %s",
852 lock->lk = xcalloc(1, sizeof(struct lock_file));
854 if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) {
855 if (errno == ENOENT && --attempts_remaining > 0) {
857 * Maybe somebody just deleted one of the
858 * directories leading to ref_file. Try
863 unable_to_lock_message(ref_file.buf, errno, err);
869 * Now we hold the lock and can read the reference without
870 * fear that its value will change.
873 if (files_read_raw_ref(&refs->base, refname,
874 lock->old_oid.hash, referent, type)) {
875 if (errno == ENOENT) {
877 /* Garden variety missing reference. */
878 strbuf_addf(err, "unable to resolve reference '%s'",
883 * Reference is missing, but that's OK. We
884 * know that there is not a conflict with
885 * another loose reference because
886 * (supposing that we are trying to lock
887 * reference "refs/foo/bar"):
889 * - We were successfully able to create
890 * the lockfile refs/foo/bar.lock, so we
891 * know there cannot be a loose reference
894 * - We got ENOENT and not EISDIR, so we
895 * know that there cannot be a loose
896 * reference named "refs/foo/bar/baz".
899 } else if (errno == EISDIR) {
901 * There is a directory in the way. It might have
902 * contained references that have been deleted. If
903 * we don't require that the reference already
904 * exists, try to remove the directory so that it
905 * doesn't cause trouble when we want to rename the
906 * lockfile into place later.
909 /* Garden variety missing reference. */
910 strbuf_addf(err, "unable to resolve reference '%s'",
913 } else if (remove_dir_recursively(&ref_file,
914 REMOVE_DIR_EMPTY_ONLY)) {
915 if (refs_verify_refname_available(
916 &refs->base, refname,
917 extras, skip, err)) {
919 * The error message set by
920 * verify_refname_available() is OK.
922 ret = TRANSACTION_NAME_CONFLICT;
926 * We can't delete the directory,
927 * but we also don't know of any
928 * references that it should
931 strbuf_addf(err, "there is a non-empty directory '%s' "
932 "blocking reference '%s'",
933 ref_file.buf, refname);
937 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {
938 strbuf_addf(err, "unable to resolve reference '%s': "
939 "reference broken", refname);
942 strbuf_addf(err, "unable to resolve reference '%s': %s",
943 refname, strerror(errno));
948 * If the ref did not exist and we are creating it,
949 * make sure there is no existing ref that conflicts
952 if (refs_verify_refname_available(
953 &refs->base, refname,
966 strbuf_release(&ref_file);
970 static int files_peel_ref(struct ref_store *ref_store,
971 const char *refname, unsigned char *sha1)
973 struct files_ref_store *refs =
974 files_downcast(ref_store, REF_STORE_READ | REF_STORE_ODB,
977 unsigned char base[20];
979 if (current_ref_iter && current_ref_iter->refname == refname) {
980 struct object_id peeled;
982 if (ref_iterator_peel(current_ref_iter, &peeled))
984 hashcpy(sha1, peeled.hash);
988 if (refs_read_ref_full(ref_store, refname,
989 RESOLVE_REF_READING, base, &flag))
993 * If the reference is packed, read its ref_entry from the
994 * cache in the hope that we already know its peeled value.
995 * We only try this optimization on packed references because
996 * (a) forcing the filling of the loose reference cache could
997 * be expensive and (b) loose references anyway usually do not
998 * have REF_KNOWS_PEELED.
1000 if (flag & REF_ISPACKED) {
1001 struct ref_entry *r = get_packed_ref(refs, refname);
1003 if (peel_entry(r, 0))
1005 hashcpy(sha1, r->u.value.peeled.hash);
1010 return peel_object(base, sha1);
1013 struct files_ref_iterator {
1014 struct ref_iterator base;
1016 struct packed_ref_cache *packed_ref_cache;
1017 struct ref_iterator *iter0;
1021 static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
1023 struct files_ref_iterator *iter =
1024 (struct files_ref_iterator *)ref_iterator;
1027 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
1028 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
1029 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
1032 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
1033 !ref_resolves_to_object(iter->iter0->refname,
1035 iter->iter0->flags))
1038 iter->base.refname = iter->iter0->refname;
1039 iter->base.oid = iter->iter0->oid;
1040 iter->base.flags = iter->iter0->flags;
1045 if (ref_iterator_abort(ref_iterator) != ITER_DONE)
1051 static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,
1052 struct object_id *peeled)
1054 struct files_ref_iterator *iter =
1055 (struct files_ref_iterator *)ref_iterator;
1057 return ref_iterator_peel(iter->iter0, peeled);
1060 static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)
1062 struct files_ref_iterator *iter =
1063 (struct files_ref_iterator *)ref_iterator;
1067 ok = ref_iterator_abort(iter->iter0);
1069 release_packed_ref_cache(iter->packed_ref_cache);
1070 base_ref_iterator_free(ref_iterator);
1074 static struct ref_iterator_vtable files_ref_iterator_vtable = {
1075 files_ref_iterator_advance,
1076 files_ref_iterator_peel,
1077 files_ref_iterator_abort
1080 static struct ref_iterator *files_ref_iterator_begin(
1081 struct ref_store *ref_store,
1082 const char *prefix, unsigned int flags)
1084 struct files_ref_store *refs;
1085 struct ref_iterator *loose_iter, *packed_iter;
1086 struct files_ref_iterator *iter;
1087 struct ref_iterator *ref_iterator;
1089 if (ref_paranoia < 0)
1090 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1092 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1094 refs = files_downcast(ref_store,
1095 REF_STORE_READ | (ref_paranoia ? 0 : REF_STORE_ODB),
1096 "ref_iterator_begin");
1098 iter = xcalloc(1, sizeof(*iter));
1099 ref_iterator = &iter->base;
1100 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);
1103 * We must make sure that all loose refs are read before
1104 * accessing the packed-refs file; this avoids a race
1105 * condition if loose refs are migrated to the packed-refs
1106 * file by a simultaneous process, but our in-memory view is
1107 * from before the migration. We ensure this as follows:
1108 * First, we call start the loose refs iteration with its
1109 * `prime_ref` argument set to true. This causes the loose
1110 * references in the subtree to be pre-read into the cache.
1111 * (If they've already been read, that's OK; we only need to
1112 * guarantee that they're read before the packed refs, not
1113 * *how much* before.) After that, we call
1114 * get_packed_ref_cache(), which internally checks whether the
1115 * packed-ref cache is up to date with what is on disk, and
1116 * re-reads it if not.
1119 loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs),
1122 iter->packed_ref_cache = get_packed_ref_cache(refs);
1123 acquire_packed_ref_cache(iter->packed_ref_cache);
1124 packed_iter = cache_ref_iterator_begin(iter->packed_ref_cache->cache,
1127 iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);
1128 iter->flags = flags;
1130 return ref_iterator;
1134 * Verify that the reference locked by lock has the value old_sha1.
1135 * Fail if the reference doesn't exist and mustexist is set. Return 0
1136 * on success. On error, write an error message to err, set errno, and
1137 * return a negative value.
1139 static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,
1140 const unsigned char *old_sha1, int mustexist,
1145 if (refs_read_ref_full(ref_store, lock->ref_name,
1146 mustexist ? RESOLVE_REF_READING : 0,
1147 lock->old_oid.hash, NULL)) {
1149 int save_errno = errno;
1150 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);
1154 oidclr(&lock->old_oid);
1158 if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {
1159 strbuf_addf(err, "ref '%s' is at %s but expected %s",
1161 oid_to_hex(&lock->old_oid),
1162 sha1_to_hex(old_sha1));
1169 static int remove_empty_directories(struct strbuf *path)
1172 * we want to create a file but there is a directory there;
1173 * if that is an empty directory (or a directory that contains
1174 * only empty directories), remove them.
1176 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
1179 static int create_reflock(const char *path, void *cb)
1181 struct lock_file *lk = cb;
1183 return hold_lock_file_for_update(lk, path, LOCK_NO_DEREF) < 0 ? -1 : 0;
1187 * Locks a ref returning the lock on success and NULL on failure.
1188 * On failure errno is set to something meaningful.
1190 static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,
1191 const char *refname,
1192 const unsigned char *old_sha1,
1193 const struct string_list *extras,
1194 const struct string_list *skip,
1195 unsigned int flags, int *type,
1198 struct strbuf ref_file = STRBUF_INIT;
1199 struct ref_lock *lock;
1201 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1202 int resolve_flags = RESOLVE_REF_NO_RECURSE;
1205 files_assert_main_repository(refs, "lock_ref_sha1_basic");
1208 lock = xcalloc(1, sizeof(struct ref_lock));
1211 resolve_flags |= RESOLVE_REF_READING;
1212 if (flags & REF_DELETING)
1213 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
1215 files_ref_path(refs, &ref_file, refname);
1216 resolved = !!refs_resolve_ref_unsafe(&refs->base,
1217 refname, resolve_flags,
1218 lock->old_oid.hash, type);
1219 if (!resolved && errno == EISDIR) {
1221 * we are trying to lock foo but we used to
1222 * have foo/bar which now does not exist;
1223 * it is normal for the empty directory 'foo'
1226 if (remove_empty_directories(&ref_file)) {
1228 if (!refs_verify_refname_available(
1230 refname, extras, skip, err))
1231 strbuf_addf(err, "there are still refs under '%s'",
1235 resolved = !!refs_resolve_ref_unsafe(&refs->base,
1236 refname, resolve_flags,
1237 lock->old_oid.hash, type);
1241 if (last_errno != ENOTDIR ||
1242 !refs_verify_refname_available(&refs->base, refname,
1244 strbuf_addf(err, "unable to resolve reference '%s': %s",
1245 refname, strerror(last_errno));
1251 * If the ref did not exist and we are creating it, make sure
1252 * there is no existing packed ref whose name begins with our
1253 * refname, nor a packed ref whose name is a proper prefix of
1256 if (is_null_oid(&lock->old_oid) &&
1257 refs_verify_refname_available(&refs->base, refname,
1258 extras, skip, err)) {
1259 last_errno = ENOTDIR;
1263 lock->lk = xcalloc(1, sizeof(struct lock_file));
1265 lock->ref_name = xstrdup(refname);
1267 if (raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {
1269 unable_to_lock_message(ref_file.buf, errno, err);
1273 if (verify_lock(&refs->base, lock, old_sha1, mustexist, err)) {
1284 strbuf_release(&ref_file);
1290 * Write an entry to the packed-refs file for the specified refname.
1291 * If peeled is non-NULL, write it as the entry's peeled value.
1293 static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,
1294 unsigned char *peeled)
1296 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);
1298 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));
1302 * An each_ref_entry_fn that writes the entry to a packed-refs file.
1304 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
1306 enum peel_status peel_status = peel_entry(entry, 0);
1308 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
1309 error("internal error: %s is not a valid packed reference!",
1311 write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,
1312 peel_status == PEEL_PEELED ?
1313 entry->u.value.peeled.hash : NULL);
1318 * Lock the packed-refs file for writing. Flags is passed to
1319 * hold_lock_file_for_update(). Return 0 on success. On errors, set
1320 * errno appropriately and return a nonzero value.
1322 static int lock_packed_refs(struct files_ref_store *refs, int flags)
1324 static int timeout_configured = 0;
1325 static int timeout_value = 1000;
1326 struct packed_ref_cache *packed_ref_cache;
1328 files_assert_main_repository(refs, "lock_packed_refs");
1330 if (!timeout_configured) {
1331 git_config_get_int("core.packedrefstimeout", &timeout_value);
1332 timeout_configured = 1;
1335 if (hold_lock_file_for_update_timeout(
1336 &packlock, files_packed_refs_path(refs),
1337 flags, timeout_value) < 0)
1340 * Get the current packed-refs while holding the lock. If the
1341 * packed-refs file has been modified since we last read it,
1342 * this will automatically invalidate the cache and re-read
1343 * the packed-refs file.
1345 packed_ref_cache = get_packed_ref_cache(refs);
1346 packed_ref_cache->lock = &packlock;
1347 /* Increment the reference count to prevent it from being freed: */
1348 acquire_packed_ref_cache(packed_ref_cache);
1353 * Write the current version of the packed refs cache from memory to
1354 * disk. The packed-refs file must already be locked for writing (see
1355 * lock_packed_refs()). Return zero on success. On errors, set errno
1356 * and return a nonzero value
1358 static int commit_packed_refs(struct files_ref_store *refs)
1360 struct packed_ref_cache *packed_ref_cache =
1361 get_packed_ref_cache(refs);
1366 files_assert_main_repository(refs, "commit_packed_refs");
1368 if (!packed_ref_cache->lock)
1369 die("internal error: packed-refs not locked");
1371 out = fdopen_lock_file(packed_ref_cache->lock, "w");
1373 die_errno("unable to fdopen packed-refs descriptor");
1375 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);
1376 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
1377 write_packed_entry_fn, out);
1379 if (commit_lock_file(packed_ref_cache->lock)) {
1383 packed_ref_cache->lock = NULL;
1384 release_packed_ref_cache(packed_ref_cache);
1390 * Rollback the lockfile for the packed-refs file, and discard the
1391 * in-memory packed reference cache. (The packed-refs file will be
1392 * read anew if it is needed again after this function is called.)
1394 static void rollback_packed_refs(struct files_ref_store *refs)
1396 struct packed_ref_cache *packed_ref_cache =
1397 get_packed_ref_cache(refs);
1399 files_assert_main_repository(refs, "rollback_packed_refs");
1401 if (!packed_ref_cache->lock)
1402 die("internal error: packed-refs not locked");
1403 rollback_lock_file(packed_ref_cache->lock);
1404 packed_ref_cache->lock = NULL;
1405 release_packed_ref_cache(packed_ref_cache);
1406 clear_packed_ref_cache(refs);
1409 struct ref_to_prune {
1410 struct ref_to_prune *next;
1411 unsigned char sha1[20];
1412 char name[FLEX_ARRAY];
1415 struct pack_refs_cb_data {
1417 struct ref_dir *packed_refs;
1418 struct ref_to_prune *ref_to_prune;
1422 * An each_ref_entry_fn that is run over loose references only. If
1423 * the loose reference can be packed, add an entry in the packed ref
1424 * cache. If the reference should be pruned, also add it to
1425 * ref_to_prune in the pack_refs_cb_data.
1427 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
1429 struct pack_refs_cb_data *cb = cb_data;
1430 enum peel_status peel_status;
1431 struct ref_entry *packed_entry;
1432 int is_tag_ref = starts_with(entry->name, "refs/tags/");
1434 /* Do not pack per-worktree refs: */
1435 if (ref_type(entry->name) != REF_TYPE_NORMAL)
1438 /* ALWAYS pack tags */
1439 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
1442 /* Do not pack symbolic or broken refs: */
1443 if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))
1446 /* Add a packed ref cache entry equivalent to the loose entry. */
1447 peel_status = peel_entry(entry, 1);
1448 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
1449 die("internal error peeling reference %s (%s)",
1450 entry->name, oid_to_hex(&entry->u.value.oid));
1451 packed_entry = find_ref_entry(cb->packed_refs, entry->name);
1453 /* Overwrite existing packed entry with info from loose entry */
1454 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
1455 oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);
1457 packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash,
1458 REF_ISPACKED | REF_KNOWS_PEELED, 0);
1459 add_ref_entry(cb->packed_refs, packed_entry);
1461 oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);
1463 /* Schedule the loose reference for pruning if requested. */
1464 if ((cb->flags & PACK_REFS_PRUNE)) {
1465 struct ref_to_prune *n;
1466 FLEX_ALLOC_STR(n, name, entry->name);
1467 hashcpy(n->sha1, entry->u.value.oid.hash);
1468 n->next = cb->ref_to_prune;
1469 cb->ref_to_prune = n;
1475 REMOVE_EMPTY_PARENTS_REF = 0x01,
1476 REMOVE_EMPTY_PARENTS_REFLOG = 0x02
1480 * Remove empty parent directories associated with the specified
1481 * reference and/or its reflog, but spare [logs/]refs/ and immediate
1482 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or
1483 * REMOVE_EMPTY_PARENTS_REFLOG.
1485 static void try_remove_empty_parents(struct files_ref_store *refs,
1486 const char *refname,
1489 struct strbuf buf = STRBUF_INIT;
1490 struct strbuf sb = STRBUF_INIT;
1494 strbuf_addstr(&buf, refname);
1496 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
1497 while (*p && *p != '/')
1499 /* tolerate duplicate slashes; see check_refname_format() */
1503 q = buf.buf + buf.len;
1504 while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {
1505 while (q > p && *q != '/')
1507 while (q > p && *(q-1) == '/')
1511 strbuf_setlen(&buf, q - buf.buf);
1514 files_ref_path(refs, &sb, buf.buf);
1515 if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))
1516 flags &= ~REMOVE_EMPTY_PARENTS_REF;
1519 files_reflog_path(refs, &sb, buf.buf);
1520 if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf))
1521 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;
1523 strbuf_release(&buf);
1524 strbuf_release(&sb);
1527 /* make sure nobody touched the ref, and unlink */
1528 static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)
1530 struct ref_transaction *transaction;
1531 struct strbuf err = STRBUF_INIT;
1533 if (check_refname_format(r->name, 0))
1536 transaction = ref_store_transaction_begin(&refs->base, &err);
1538 ref_transaction_delete(transaction, r->name, r->sha1,
1539 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||
1540 ref_transaction_commit(transaction, &err)) {
1541 ref_transaction_free(transaction);
1542 error("%s", err.buf);
1543 strbuf_release(&err);
1546 ref_transaction_free(transaction);
1547 strbuf_release(&err);
1550 static void prune_refs(struct files_ref_store *refs, struct ref_to_prune *r)
1558 static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
1560 struct files_ref_store *refs =
1561 files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB,
1563 struct pack_refs_cb_data cbdata;
1565 memset(&cbdata, 0, sizeof(cbdata));
1566 cbdata.flags = flags;
1568 lock_packed_refs(refs, LOCK_DIE_ON_ERROR);
1569 cbdata.packed_refs = get_packed_refs(refs);
1571 do_for_each_entry_in_dir(get_loose_ref_dir(refs),
1572 pack_if_possible_fn, &cbdata);
1574 if (commit_packed_refs(refs))
1575 die_errno("unable to overwrite old ref-pack file");
1577 prune_refs(refs, cbdata.ref_to_prune);
1582 * Rewrite the packed-refs file, omitting any refs listed in
1583 * 'refnames'. On error, leave packed-refs unchanged, write an error
1584 * message to 'err', and return a nonzero value.
1586 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.
1588 static int repack_without_refs(struct files_ref_store *refs,
1589 struct string_list *refnames, struct strbuf *err)
1591 struct ref_dir *packed;
1592 struct string_list_item *refname;
1593 int ret, needs_repacking = 0, removed = 0;
1595 files_assert_main_repository(refs, "repack_without_refs");
1598 /* Look for a packed ref */
1599 for_each_string_list_item(refname, refnames) {
1600 if (get_packed_ref(refs, refname->string)) {
1601 needs_repacking = 1;
1606 /* Avoid locking if we have nothing to do */
1607 if (!needs_repacking)
1608 return 0; /* no refname exists in packed refs */
1610 if (lock_packed_refs(refs, 0)) {
1611 unable_to_lock_message(files_packed_refs_path(refs), errno, err);
1614 packed = get_packed_refs(refs);
1616 /* Remove refnames from the cache */
1617 for_each_string_list_item(refname, refnames)
1618 if (remove_entry_from_dir(packed, refname->string) != -1)
1622 * All packed entries disappeared while we were
1623 * acquiring the lock.
1625 rollback_packed_refs(refs);
1629 /* Write what remains */
1630 ret = commit_packed_refs(refs);
1632 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",
1637 static int files_delete_refs(struct ref_store *ref_store,
1638 struct string_list *refnames, unsigned int flags)
1640 struct files_ref_store *refs =
1641 files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
1642 struct strbuf err = STRBUF_INIT;
1648 result = repack_without_refs(refs, refnames, &err);
1651 * If we failed to rewrite the packed-refs file, then
1652 * it is unsafe to try to remove loose refs, because
1653 * doing so might expose an obsolete packed value for
1654 * a reference that might even point at an object that
1655 * has been garbage collected.
1657 if (refnames->nr == 1)
1658 error(_("could not delete reference %s: %s"),
1659 refnames->items[0].string, err.buf);
1661 error(_("could not delete references: %s"), err.buf);
1666 for (i = 0; i < refnames->nr; i++) {
1667 const char *refname = refnames->items[i].string;
1669 if (refs_delete_ref(&refs->base, NULL, refname, NULL, flags))
1670 result |= error(_("could not remove reference %s"), refname);
1674 strbuf_release(&err);
1679 * People using contrib's git-new-workdir have .git/logs/refs ->
1680 * /some/other/path/.git/logs/refs, and that may live on another device.
1682 * IOW, to avoid cross device rename errors, the temporary renamed log must
1683 * live into logs/refs.
1685 #define TMP_RENAMED_LOG "refs/.tmp-renamed-log"
1688 const char *tmp_renamed_log;
1692 static int rename_tmp_log_callback(const char *path, void *cb_data)
1694 struct rename_cb *cb = cb_data;
1696 if (rename(cb->tmp_renamed_log, path)) {
1698 * rename(a, b) when b is an existing directory ought
1699 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.
1700 * Sheesh. Record the true errno for error reporting,
1701 * but report EISDIR to raceproof_create_file() so
1702 * that it knows to retry.
1704 cb->true_errno = errno;
1705 if (errno == ENOTDIR)
1713 static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname)
1715 struct strbuf path = STRBUF_INIT;
1716 struct strbuf tmp = STRBUF_INIT;
1717 struct rename_cb cb;
1720 files_reflog_path(refs, &path, newrefname);
1721 files_reflog_path(refs, &tmp, TMP_RENAMED_LOG);
1722 cb.tmp_renamed_log = tmp.buf;
1723 ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);
1725 if (errno == EISDIR)
1726 error("directory not empty: %s", path.buf);
1728 error("unable to move logfile %s to %s: %s",
1730 strerror(cb.true_errno));
1733 strbuf_release(&path);
1734 strbuf_release(&tmp);
1738 static int write_ref_to_lockfile(struct ref_lock *lock,
1739 const unsigned char *sha1, struct strbuf *err);
1740 static int commit_ref_update(struct files_ref_store *refs,
1741 struct ref_lock *lock,
1742 const unsigned char *sha1, const char *logmsg,
1743 struct strbuf *err);
1745 static int files_rename_ref(struct ref_store *ref_store,
1746 const char *oldrefname, const char *newrefname,
1749 struct files_ref_store *refs =
1750 files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");
1751 unsigned char sha1[20], orig_sha1[20];
1752 int flag = 0, logmoved = 0;
1753 struct ref_lock *lock;
1754 struct stat loginfo;
1755 struct strbuf sb_oldref = STRBUF_INIT;
1756 struct strbuf sb_newref = STRBUF_INIT;
1757 struct strbuf tmp_renamed_log = STRBUF_INIT;
1759 struct strbuf err = STRBUF_INIT;
1761 files_reflog_path(refs, &sb_oldref, oldrefname);
1762 files_reflog_path(refs, &sb_newref, newrefname);
1763 files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG);
1765 log = !lstat(sb_oldref.buf, &loginfo);
1766 if (log && S_ISLNK(loginfo.st_mode)) {
1767 ret = error("reflog for %s is a symlink", oldrefname);
1771 if (!refs_resolve_ref_unsafe(&refs->base, oldrefname,
1772 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
1773 orig_sha1, &flag)) {
1774 ret = error("refname %s not found", oldrefname);
1778 if (flag & REF_ISSYMREF) {
1779 ret = error("refname %s is a symbolic ref, renaming it is not supported",
1783 if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) {
1788 if (log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {
1789 ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
1790 oldrefname, strerror(errno));
1794 if (refs_delete_ref(&refs->base, logmsg, oldrefname,
1795 orig_sha1, REF_NODEREF)) {
1796 error("unable to delete old %s", oldrefname);
1801 * Since we are doing a shallow lookup, sha1 is not the
1802 * correct value to pass to delete_ref as old_sha1. But that
1803 * doesn't matter, because an old_sha1 check wouldn't add to
1804 * the safety anyway; we want to delete the reference whatever
1805 * its current value.
1807 if (!refs_read_ref_full(&refs->base, newrefname,
1808 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
1810 refs_delete_ref(&refs->base, NULL, newrefname,
1811 NULL, REF_NODEREF)) {
1812 if (errno == EISDIR) {
1813 struct strbuf path = STRBUF_INIT;
1816 files_ref_path(refs, &path, newrefname);
1817 result = remove_empty_directories(&path);
1818 strbuf_release(&path);
1821 error("Directory not empty: %s", newrefname);
1825 error("unable to delete existing %s", newrefname);
1830 if (log && rename_tmp_log(refs, newrefname))
1835 lock = lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,
1836 REF_NODEREF, NULL, &err);
1838 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
1839 strbuf_release(&err);
1842 hashcpy(lock->old_oid.hash, orig_sha1);
1844 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
1845 commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {
1846 error("unable to write current sha1 into %s: %s", newrefname, err.buf);
1847 strbuf_release(&err);
1855 lock = lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,
1856 REF_NODEREF, NULL, &err);
1858 error("unable to lock %s for rollback: %s", oldrefname, err.buf);
1859 strbuf_release(&err);
1863 flag = log_all_ref_updates;
1864 log_all_ref_updates = LOG_REFS_NONE;
1865 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
1866 commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {
1867 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
1868 strbuf_release(&err);
1870 log_all_ref_updates = flag;
1873 if (logmoved && rename(sb_newref.buf, sb_oldref.buf))
1874 error("unable to restore logfile %s from %s: %s",
1875 oldrefname, newrefname, strerror(errno));
1876 if (!logmoved && log &&
1877 rename(tmp_renamed_log.buf, sb_oldref.buf))
1878 error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s",
1879 oldrefname, strerror(errno));
1882 strbuf_release(&sb_newref);
1883 strbuf_release(&sb_oldref);
1884 strbuf_release(&tmp_renamed_log);
1889 static int close_ref(struct ref_lock *lock)
1891 if (close_lock_file(lock->lk))
1896 static int commit_ref(struct ref_lock *lock)
1898 char *path = get_locked_file_path(lock->lk);
1901 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {
1903 * There is a directory at the path we want to rename
1904 * the lockfile to. Hopefully it is empty; try to
1907 size_t len = strlen(path);
1908 struct strbuf sb_path = STRBUF_INIT;
1910 strbuf_attach(&sb_path, path, len, len);
1913 * If this fails, commit_lock_file() will also fail
1914 * and will report the problem.
1916 remove_empty_directories(&sb_path);
1917 strbuf_release(&sb_path);
1922 if (commit_lock_file(lock->lk))
1927 static int open_or_create_logfile(const char *path, void *cb)
1931 *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);
1932 return (*fd < 0) ? -1 : 0;
1936 * Create a reflog for a ref. If force_create = 0, only create the
1937 * reflog for certain refs (those for which should_autocreate_reflog
1938 * returns non-zero). Otherwise, create it regardless of the reference
1939 * name. If the logfile already existed or was created, return 0 and
1940 * set *logfd to the file descriptor opened for appending to the file.
1941 * If no logfile exists and we decided not to create one, return 0 and
1942 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and
1945 static int log_ref_setup(struct files_ref_store *refs,
1946 const char *refname, int force_create,
1947 int *logfd, struct strbuf *err)
1949 struct strbuf logfile_sb = STRBUF_INIT;
1952 files_reflog_path(refs, &logfile_sb, refname);
1953 logfile = strbuf_detach(&logfile_sb, NULL);
1955 if (force_create || should_autocreate_reflog(refname)) {
1956 if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {
1957 if (errno == ENOENT)
1958 strbuf_addf(err, "unable to create directory for '%s': "
1959 "%s", logfile, strerror(errno));
1960 else if (errno == EISDIR)
1961 strbuf_addf(err, "there are still logs under '%s'",
1964 strbuf_addf(err, "unable to append to '%s': %s",
1965 logfile, strerror(errno));
1970 *logfd = open(logfile, O_APPEND | O_WRONLY, 0666);
1972 if (errno == ENOENT || errno == EISDIR) {
1974 * The logfile doesn't already exist,
1975 * but that is not an error; it only
1976 * means that we won't write log
1981 strbuf_addf(err, "unable to append to '%s': %s",
1982 logfile, strerror(errno));
1989 adjust_shared_perm(logfile);
1999 static int files_create_reflog(struct ref_store *ref_store,
2000 const char *refname, int force_create,
2003 struct files_ref_store *refs =
2004 files_downcast(ref_store, REF_STORE_WRITE, "create_reflog");
2007 if (log_ref_setup(refs, refname, force_create, &fd, err))
2016 static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
2017 const unsigned char *new_sha1,
2018 const char *committer, const char *msg)
2020 int msglen, written;
2021 unsigned maxlen, len;
2024 msglen = msg ? strlen(msg) : 0;
2025 maxlen = strlen(committer) + msglen + 100;
2026 logrec = xmalloc(maxlen);
2027 len = xsnprintf(logrec, maxlen, "%s %s %s\n",
2028 sha1_to_hex(old_sha1),
2029 sha1_to_hex(new_sha1),
2032 len += copy_reflog_msg(logrec + len - 1, msg) - 1;
2034 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;
2042 static int files_log_ref_write(struct files_ref_store *refs,
2043 const char *refname, const unsigned char *old_sha1,
2044 const unsigned char *new_sha1, const char *msg,
2045 int flags, struct strbuf *err)
2049 if (log_all_ref_updates == LOG_REFS_UNSET)
2050 log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;
2052 result = log_ref_setup(refs, refname,
2053 flags & REF_FORCE_CREATE_REFLOG,
2061 result = log_ref_write_fd(logfd, old_sha1, new_sha1,
2062 git_committer_info(0), msg);
2064 struct strbuf sb = STRBUF_INIT;
2065 int save_errno = errno;
2067 files_reflog_path(refs, &sb, refname);
2068 strbuf_addf(err, "unable to append to '%s': %s",
2069 sb.buf, strerror(save_errno));
2070 strbuf_release(&sb);
2075 struct strbuf sb = STRBUF_INIT;
2076 int save_errno = errno;
2078 files_reflog_path(refs, &sb, refname);
2079 strbuf_addf(err, "unable to append to '%s': %s",
2080 sb.buf, strerror(save_errno));
2081 strbuf_release(&sb);
2088 * Write sha1 into the open lockfile, then close the lockfile. On
2089 * errors, rollback the lockfile, fill in *err and
2092 static int write_ref_to_lockfile(struct ref_lock *lock,
2093 const unsigned char *sha1, struct strbuf *err)
2095 static char term = '\n';
2099 o = parse_object(sha1);
2102 "trying to write ref '%s' with nonexistent object %s",
2103 lock->ref_name, sha1_to_hex(sha1));
2107 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2109 "trying to write non-commit object %s to branch '%s'",
2110 sha1_to_hex(sha1), lock->ref_name);
2114 fd = get_lock_file_fd(lock->lk);
2115 if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 ||
2116 write_in_full(fd, &term, 1) != 1 ||
2117 close_ref(lock) < 0) {
2119 "couldn't write '%s'", get_lock_file_path(lock->lk));
2127 * Commit a change to a loose reference that has already been written
2128 * to the loose reference lockfile. Also update the reflogs if
2129 * necessary, using the specified lockmsg (which can be NULL).
2131 static int commit_ref_update(struct files_ref_store *refs,
2132 struct ref_lock *lock,
2133 const unsigned char *sha1, const char *logmsg,
2136 files_assert_main_repository(refs, "commit_ref_update");
2138 clear_loose_ref_cache(refs);
2139 if (files_log_ref_write(refs, lock->ref_name,
2140 lock->old_oid.hash, sha1,
2142 char *old_msg = strbuf_detach(err, NULL);
2143 strbuf_addf(err, "cannot update the ref '%s': %s",
2144 lock->ref_name, old_msg);
2150 if (strcmp(lock->ref_name, "HEAD") != 0) {
2152 * Special hack: If a branch is updated directly and HEAD
2153 * points to it (may happen on the remote side of a push
2154 * for example) then logically the HEAD reflog should be
2156 * A generic solution implies reverse symref information,
2157 * but finding all symrefs pointing to the given branch
2158 * would be rather costly for this rare event (the direct
2159 * update of a branch) to be worth it. So let's cheat and
2160 * check with HEAD only which should cover 99% of all usage
2161 * scenarios (even 100% of the default ones).
2163 unsigned char head_sha1[20];
2165 const char *head_ref;
2167 head_ref = refs_resolve_ref_unsafe(&refs->base, "HEAD",
2168 RESOLVE_REF_READING,
2169 head_sha1, &head_flag);
2170 if (head_ref && (head_flag & REF_ISSYMREF) &&
2171 !strcmp(head_ref, lock->ref_name)) {
2172 struct strbuf log_err = STRBUF_INIT;
2173 if (files_log_ref_write(refs, "HEAD",
2174 lock->old_oid.hash, sha1,
2175 logmsg, 0, &log_err)) {
2176 error("%s", log_err.buf);
2177 strbuf_release(&log_err);
2182 if (commit_ref(lock)) {
2183 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
2192 static int create_ref_symlink(struct ref_lock *lock, const char *target)
2195 #ifndef NO_SYMLINK_HEAD
2196 char *ref_path = get_locked_file_path(lock->lk);
2198 ret = symlink(target, ref_path);
2202 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2207 static void update_symref_reflog(struct files_ref_store *refs,
2208 struct ref_lock *lock, const char *refname,
2209 const char *target, const char *logmsg)
2211 struct strbuf err = STRBUF_INIT;
2212 unsigned char new_sha1[20];
2214 !refs_read_ref_full(&refs->base, target,
2215 RESOLVE_REF_READING, new_sha1, NULL) &&
2216 files_log_ref_write(refs, refname, lock->old_oid.hash,
2217 new_sha1, logmsg, 0, &err)) {
2218 error("%s", err.buf);
2219 strbuf_release(&err);
2223 static int create_symref_locked(struct files_ref_store *refs,
2224 struct ref_lock *lock, const char *refname,
2225 const char *target, const char *logmsg)
2227 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {
2228 update_symref_reflog(refs, lock, refname, target, logmsg);
2232 if (!fdopen_lock_file(lock->lk, "w"))
2233 return error("unable to fdopen %s: %s",
2234 lock->lk->tempfile.filename.buf, strerror(errno));
2236 update_symref_reflog(refs, lock, refname, target, logmsg);
2238 /* no error check; commit_ref will check ferror */
2239 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);
2240 if (commit_ref(lock) < 0)
2241 return error("unable to write symref for %s: %s", refname,
2246 static int files_create_symref(struct ref_store *ref_store,
2247 const char *refname, const char *target,
2250 struct files_ref_store *refs =
2251 files_downcast(ref_store, REF_STORE_WRITE, "create_symref");
2252 struct strbuf err = STRBUF_INIT;
2253 struct ref_lock *lock;
2256 lock = lock_ref_sha1_basic(refs, refname, NULL,
2257 NULL, NULL, REF_NODEREF, NULL,
2260 error("%s", err.buf);
2261 strbuf_release(&err);
2265 ret = create_symref_locked(refs, lock, refname, target, logmsg);
2270 int set_worktree_head_symref(const char *gitdir, const char *target, const char *logmsg)
2273 * FIXME: this obviously will not work well for future refs
2274 * backends. This function needs to die.
2276 struct files_ref_store *refs =
2277 files_downcast(get_main_ref_store(),
2281 static struct lock_file head_lock;
2282 struct ref_lock *lock;
2283 struct strbuf head_path = STRBUF_INIT;
2284 const char *head_rel;
2287 strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir));
2288 if (hold_lock_file_for_update(&head_lock, head_path.buf,
2289 LOCK_NO_DEREF) < 0) {
2290 struct strbuf err = STRBUF_INIT;
2291 unable_to_lock_message(head_path.buf, errno, &err);
2292 error("%s", err.buf);
2293 strbuf_release(&err);
2294 strbuf_release(&head_path);
2298 /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for
2300 head_rel = remove_leading_path(head_path.buf,
2301 absolute_path(get_git_common_dir()));
2302 /* to make use of create_symref_locked(), initialize ref_lock */
2303 lock = xcalloc(1, sizeof(struct ref_lock));
2304 lock->lk = &head_lock;
2305 lock->ref_name = xstrdup(head_rel);
2307 ret = create_symref_locked(refs, lock, head_rel, target, logmsg);
2309 unlock_ref(lock); /* will free lock */
2310 strbuf_release(&head_path);
2314 static int files_reflog_exists(struct ref_store *ref_store,
2315 const char *refname)
2317 struct files_ref_store *refs =
2318 files_downcast(ref_store, REF_STORE_READ, "reflog_exists");
2319 struct strbuf sb = STRBUF_INIT;
2323 files_reflog_path(refs, &sb, refname);
2324 ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode);
2325 strbuf_release(&sb);
2329 static int files_delete_reflog(struct ref_store *ref_store,
2330 const char *refname)
2332 struct files_ref_store *refs =
2333 files_downcast(ref_store, REF_STORE_WRITE, "delete_reflog");
2334 struct strbuf sb = STRBUF_INIT;
2337 files_reflog_path(refs, &sb, refname);
2338 ret = remove_path(sb.buf);
2339 strbuf_release(&sb);
2343 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
2345 struct object_id ooid, noid;
2346 char *email_end, *message;
2347 unsigned long timestamp;
2349 const char *p = sb->buf;
2351 /* old SP new SP name <email> SP time TAB msg LF */
2352 if (!sb->len || sb->buf[sb->len - 1] != '\n' ||
2353 parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||
2354 parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||
2355 !(email_end = strchr(p, '>')) ||
2356 email_end[1] != ' ' ||
2357 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2358 !message || message[0] != ' ' ||
2359 (message[1] != '+' && message[1] != '-') ||
2360 !isdigit(message[2]) || !isdigit(message[3]) ||
2361 !isdigit(message[4]) || !isdigit(message[5]))
2362 return 0; /* corrupt? */
2363 email_end[1] = '\0';
2364 tz = strtol(message + 1, NULL, 10);
2365 if (message[6] != '\t')
2369 return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);
2372 static char *find_beginning_of_line(char *bob, char *scan)
2374 while (bob < scan && *(--scan) != '\n')
2375 ; /* keep scanning backwards */
2377 * Return either beginning of the buffer, or LF at the end of
2378 * the previous line.
2383 static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,
2384 const char *refname,
2385 each_reflog_ent_fn fn,
2388 struct files_ref_store *refs =
2389 files_downcast(ref_store, REF_STORE_READ,
2390 "for_each_reflog_ent_reverse");
2391 struct strbuf sb = STRBUF_INIT;
2394 int ret = 0, at_tail = 1;
2396 files_reflog_path(refs, &sb, refname);
2397 logfp = fopen(sb.buf, "r");
2398 strbuf_release(&sb);
2402 /* Jump to the end */
2403 if (fseek(logfp, 0, SEEK_END) < 0)
2404 return error("cannot seek back reflog for %s: %s",
2405 refname, strerror(errno));
2407 while (!ret && 0 < pos) {
2413 /* Fill next block from the end */
2414 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
2415 if (fseek(logfp, pos - cnt, SEEK_SET))
2416 return error("cannot seek back reflog for %s: %s",
2417 refname, strerror(errno));
2418 nread = fread(buf, cnt, 1, logfp);
2420 return error("cannot read %d bytes from reflog for %s: %s",
2421 cnt, refname, strerror(errno));
2424 scanp = endp = buf + cnt;
2425 if (at_tail && scanp[-1] == '\n')
2426 /* Looking at the final LF at the end of the file */
2430 while (buf < scanp) {
2432 * terminating LF of the previous line, or the beginning
2437 bp = find_beginning_of_line(buf, scanp);
2441 * The newline is the end of the previous line,
2442 * so we know we have complete line starting
2443 * at (bp + 1). Prefix it onto any prior data
2444 * we collected for the line and process it.
2446 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
2449 ret = show_one_reflog_ent(&sb, fn, cb_data);
2455 * We are at the start of the buffer, and the
2456 * start of the file; there is no previous
2457 * line, and we have everything for this one.
2458 * Process it, and we can end the loop.
2460 strbuf_splice(&sb, 0, 0, buf, endp - buf);
2461 ret = show_one_reflog_ent(&sb, fn, cb_data);
2468 * We are at the start of the buffer, and there
2469 * is more file to read backwards. Which means
2470 * we are in the middle of a line. Note that we
2471 * may get here even if *bp was a newline; that
2472 * just means we are at the exact end of the
2473 * previous line, rather than some spot in the
2476 * Save away what we have to be combined with
2477 * the data from the next read.
2479 strbuf_splice(&sb, 0, 0, buf, endp - buf);
2486 die("BUG: reverse reflog parser had leftover data");
2489 strbuf_release(&sb);
2493 static int files_for_each_reflog_ent(struct ref_store *ref_store,
2494 const char *refname,
2495 each_reflog_ent_fn fn, void *cb_data)
2497 struct files_ref_store *refs =
2498 files_downcast(ref_store, REF_STORE_READ,
2499 "for_each_reflog_ent");
2501 struct strbuf sb = STRBUF_INIT;
2504 files_reflog_path(refs, &sb, refname);
2505 logfp = fopen(sb.buf, "r");
2506 strbuf_release(&sb);
2510 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
2511 ret = show_one_reflog_ent(&sb, fn, cb_data);
2513 strbuf_release(&sb);
2517 struct files_reflog_iterator {
2518 struct ref_iterator base;
2520 struct ref_store *ref_store;
2521 struct dir_iterator *dir_iterator;
2522 struct object_id oid;
2525 static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
2527 struct files_reflog_iterator *iter =
2528 (struct files_reflog_iterator *)ref_iterator;
2529 struct dir_iterator *diter = iter->dir_iterator;
2532 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
2535 if (!S_ISREG(diter->st.st_mode))
2537 if (diter->basename[0] == '.')
2539 if (ends_with(diter->basename, ".lock"))
2542 if (refs_read_ref_full(iter->ref_store,
2543 diter->relative_path, 0,
2544 iter->oid.hash, &flags)) {
2545 error("bad ref for %s", diter->path.buf);
2549 iter->base.refname = diter->relative_path;
2550 iter->base.oid = &iter->oid;
2551 iter->base.flags = flags;
2555 iter->dir_iterator = NULL;
2556 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)
2561 static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,
2562 struct object_id *peeled)
2564 die("BUG: ref_iterator_peel() called for reflog_iterator");
2567 static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)
2569 struct files_reflog_iterator *iter =
2570 (struct files_reflog_iterator *)ref_iterator;
2573 if (iter->dir_iterator)
2574 ok = dir_iterator_abort(iter->dir_iterator);
2576 base_ref_iterator_free(ref_iterator);
2580 static struct ref_iterator_vtable files_reflog_iterator_vtable = {
2581 files_reflog_iterator_advance,
2582 files_reflog_iterator_peel,
2583 files_reflog_iterator_abort
2586 static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)
2588 struct files_ref_store *refs =
2589 files_downcast(ref_store, REF_STORE_READ,
2590 "reflog_iterator_begin");
2591 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));
2592 struct ref_iterator *ref_iterator = &iter->base;
2593 struct strbuf sb = STRBUF_INIT;
2595 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);
2596 files_reflog_path(refs, &sb, NULL);
2597 iter->dir_iterator = dir_iterator_begin(sb.buf);
2598 iter->ref_store = ref_store;
2599 strbuf_release(&sb);
2600 return ref_iterator;
2603 static int ref_update_reject_duplicates(struct string_list *refnames,
2606 int i, n = refnames->nr;
2610 for (i = 1; i < n; i++)
2611 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {
2613 "multiple updates for ref '%s' not allowed.",
2614 refnames->items[i].string);
2621 * If update is a direct update of head_ref (the reference pointed to
2622 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.
2624 static int split_head_update(struct ref_update *update,
2625 struct ref_transaction *transaction,
2626 const char *head_ref,
2627 struct string_list *affected_refnames,
2630 struct string_list_item *item;
2631 struct ref_update *new_update;
2633 if ((update->flags & REF_LOG_ONLY) ||
2634 (update->flags & REF_ISPRUNING) ||
2635 (update->flags & REF_UPDATE_VIA_HEAD))
2638 if (strcmp(update->refname, head_ref))
2642 * First make sure that HEAD is not already in the
2643 * transaction. This insertion is O(N) in the transaction
2644 * size, but it happens at most once per transaction.
2646 item = string_list_insert(affected_refnames, "HEAD");
2648 /* An entry already existed */
2650 "multiple updates for 'HEAD' (including one "
2651 "via its referent '%s') are not allowed",
2653 return TRANSACTION_NAME_CONFLICT;
2656 new_update = ref_transaction_add_update(
2657 transaction, "HEAD",
2658 update->flags | REF_LOG_ONLY | REF_NODEREF,
2659 update->new_sha1, update->old_sha1,
2662 item->util = new_update;
2668 * update is for a symref that points at referent and doesn't have
2669 * REF_NODEREF set. Split it into two updates:
2670 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set
2671 * - A new, separate update for the referent reference
2672 * Note that the new update will itself be subject to splitting when
2673 * the iteration gets to it.
2675 static int split_symref_update(struct files_ref_store *refs,
2676 struct ref_update *update,
2677 const char *referent,
2678 struct ref_transaction *transaction,
2679 struct string_list *affected_refnames,
2682 struct string_list_item *item;
2683 struct ref_update *new_update;
2684 unsigned int new_flags;
2687 * First make sure that referent is not already in the
2688 * transaction. This insertion is O(N) in the transaction
2689 * size, but it happens at most once per symref in a
2692 item = string_list_insert(affected_refnames, referent);
2694 /* An entry already existed */
2696 "multiple updates for '%s' (including one "
2697 "via symref '%s') are not allowed",
2698 referent, update->refname);
2699 return TRANSACTION_NAME_CONFLICT;
2702 new_flags = update->flags;
2703 if (!strcmp(update->refname, "HEAD")) {
2705 * Record that the new update came via HEAD, so that
2706 * when we process it, split_head_update() doesn't try
2707 * to add another reflog update for HEAD. Note that
2708 * this bit will be propagated if the new_update
2709 * itself needs to be split.
2711 new_flags |= REF_UPDATE_VIA_HEAD;
2714 new_update = ref_transaction_add_update(
2715 transaction, referent, new_flags,
2716 update->new_sha1, update->old_sha1,
2719 new_update->parent_update = update;
2722 * Change the symbolic ref update to log only. Also, it
2723 * doesn't need to check its old SHA-1 value, as that will be
2724 * done when new_update is processed.
2726 update->flags |= REF_LOG_ONLY | REF_NODEREF;
2727 update->flags &= ~REF_HAVE_OLD;
2729 item->util = new_update;
2735 * Return the refname under which update was originally requested.
2737 static const char *original_update_refname(struct ref_update *update)
2739 while (update->parent_update)
2740 update = update->parent_update;
2742 return update->refname;
2746 * Check whether the REF_HAVE_OLD and old_oid values stored in update
2747 * are consistent with oid, which is the reference's current value. If
2748 * everything is OK, return 0; otherwise, write an error message to
2749 * err and return -1.
2751 static int check_old_oid(struct ref_update *update, struct object_id *oid,
2754 if (!(update->flags & REF_HAVE_OLD) ||
2755 !hashcmp(oid->hash, update->old_sha1))
2758 if (is_null_sha1(update->old_sha1))
2759 strbuf_addf(err, "cannot lock ref '%s': "
2760 "reference already exists",
2761 original_update_refname(update));
2762 else if (is_null_oid(oid))
2763 strbuf_addf(err, "cannot lock ref '%s': "
2764 "reference is missing but expected %s",
2765 original_update_refname(update),
2766 sha1_to_hex(update->old_sha1));
2768 strbuf_addf(err, "cannot lock ref '%s': "
2769 "is at %s but expected %s",
2770 original_update_refname(update),
2772 sha1_to_hex(update->old_sha1));
2778 * Prepare for carrying out update:
2779 * - Lock the reference referred to by update.
2780 * - Read the reference under lock.
2781 * - Check that its old SHA-1 value (if specified) is correct, and in
2782 * any case record it in update->lock->old_oid for later use when
2783 * writing the reflog.
2784 * - If it is a symref update without REF_NODEREF, split it up into a
2785 * REF_LOG_ONLY update of the symref and add a separate update for
2786 * the referent to transaction.
2787 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY
2790 static int lock_ref_for_update(struct files_ref_store *refs,
2791 struct ref_update *update,
2792 struct ref_transaction *transaction,
2793 const char *head_ref,
2794 struct string_list *affected_refnames,
2797 struct strbuf referent = STRBUF_INIT;
2798 int mustexist = (update->flags & REF_HAVE_OLD) &&
2799 !is_null_sha1(update->old_sha1);
2801 struct ref_lock *lock;
2803 files_assert_main_repository(refs, "lock_ref_for_update");
2805 if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))
2806 update->flags |= REF_DELETING;
2809 ret = split_head_update(update, transaction, head_ref,
2810 affected_refnames, err);
2815 ret = lock_raw_ref(refs, update->refname, mustexist,
2816 affected_refnames, NULL,
2818 &update->type, err);
2822 reason = strbuf_detach(err, NULL);
2823 strbuf_addf(err, "cannot lock ref '%s': %s",
2824 original_update_refname(update), reason);
2829 update->backend_data = lock;
2831 if (update->type & REF_ISSYMREF) {
2832 if (update->flags & REF_NODEREF) {
2834 * We won't be reading the referent as part of
2835 * the transaction, so we have to read it here
2836 * to record and possibly check old_sha1:
2838 if (refs_read_ref_full(&refs->base,
2840 lock->old_oid.hash, NULL)) {
2841 if (update->flags & REF_HAVE_OLD) {
2842 strbuf_addf(err, "cannot lock ref '%s': "
2843 "error reading reference",
2844 original_update_refname(update));
2847 } else if (check_old_oid(update, &lock->old_oid, err)) {
2848 return TRANSACTION_GENERIC_ERROR;
2852 * Create a new update for the reference this
2853 * symref is pointing at. Also, we will record
2854 * and verify old_sha1 for this update as part
2855 * of processing the split-off update, so we
2856 * don't have to do it here.
2858 ret = split_symref_update(refs, update,
2859 referent.buf, transaction,
2860 affected_refnames, err);
2865 struct ref_update *parent_update;
2867 if (check_old_oid(update, &lock->old_oid, err))
2868 return TRANSACTION_GENERIC_ERROR;
2871 * If this update is happening indirectly because of a
2872 * symref update, record the old SHA-1 in the parent
2875 for (parent_update = update->parent_update;
2877 parent_update = parent_update->parent_update) {
2878 struct ref_lock *parent_lock = parent_update->backend_data;
2879 oidcpy(&parent_lock->old_oid, &lock->old_oid);
2883 if ((update->flags & REF_HAVE_NEW) &&
2884 !(update->flags & REF_DELETING) &&
2885 !(update->flags & REF_LOG_ONLY)) {
2886 if (!(update->type & REF_ISSYMREF) &&
2887 !hashcmp(lock->old_oid.hash, update->new_sha1)) {
2889 * The reference already has the desired
2890 * value, so we don't need to write it.
2892 } else if (write_ref_to_lockfile(lock, update->new_sha1,
2894 char *write_err = strbuf_detach(err, NULL);
2897 * The lock was freed upon failure of
2898 * write_ref_to_lockfile():
2900 update->backend_data = NULL;
2902 "cannot update ref '%s': %s",
2903 update->refname, write_err);
2905 return TRANSACTION_GENERIC_ERROR;
2907 update->flags |= REF_NEEDS_COMMIT;
2910 if (!(update->flags & REF_NEEDS_COMMIT)) {
2912 * We didn't call write_ref_to_lockfile(), so
2913 * the lockfile is still open. Close it to
2914 * free up the file descriptor:
2916 if (close_ref(lock)) {
2917 strbuf_addf(err, "couldn't close '%s.lock'",
2919 return TRANSACTION_GENERIC_ERROR;
2925 static int files_transaction_commit(struct ref_store *ref_store,
2926 struct ref_transaction *transaction,
2929 struct files_ref_store *refs =
2930 files_downcast(ref_store, REF_STORE_WRITE,
2931 "ref_transaction_commit");
2933 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;
2934 struct string_list_item *ref_to_delete;
2935 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
2936 char *head_ref = NULL;
2938 struct object_id head_oid;
2939 struct strbuf sb = STRBUF_INIT;
2943 if (transaction->state != REF_TRANSACTION_OPEN)
2944 die("BUG: commit called for transaction that is not open");
2946 if (!transaction->nr) {
2947 transaction->state = REF_TRANSACTION_CLOSED;
2952 * Fail if a refname appears more than once in the
2953 * transaction. (If we end up splitting up any updates using
2954 * split_symref_update() or split_head_update(), those
2955 * functions will check that the new updates don't have the
2956 * same refname as any existing ones.)
2958 for (i = 0; i < transaction->nr; i++) {
2959 struct ref_update *update = transaction->updates[i];
2960 struct string_list_item *item =
2961 string_list_append(&affected_refnames, update->refname);
2964 * We store a pointer to update in item->util, but at
2965 * the moment we never use the value of this field
2966 * except to check whether it is non-NULL.
2968 item->util = update;
2970 string_list_sort(&affected_refnames);
2971 if (ref_update_reject_duplicates(&affected_refnames, err)) {
2972 ret = TRANSACTION_GENERIC_ERROR;
2977 * Special hack: If a branch is updated directly and HEAD
2978 * points to it (may happen on the remote side of a push
2979 * for example) then logically the HEAD reflog should be
2982 * A generic solution would require reverse symref lookups,
2983 * but finding all symrefs pointing to a given branch would be
2984 * rather costly for this rare event (the direct update of a
2985 * branch) to be worth it. So let's cheat and check with HEAD
2986 * only, which should cover 99% of all usage scenarios (even
2987 * 100% of the default ones).
2989 * So if HEAD is a symbolic reference, then record the name of
2990 * the reference that it points to. If we see an update of
2991 * head_ref within the transaction, then split_head_update()
2992 * arranges for the reflog of HEAD to be updated, too.
2994 head_ref = refs_resolve_refdup(ref_store, "HEAD",
2995 RESOLVE_REF_NO_RECURSE,
2996 head_oid.hash, &head_type);
2998 if (head_ref && !(head_type & REF_ISSYMREF)) {
3004 * Acquire all locks, verify old values if provided, check
3005 * that new values are valid, and write new values to the
3006 * lockfiles, ready to be activated. Only keep one lockfile
3007 * open at a time to avoid running out of file descriptors.
3009 for (i = 0; i < transaction->nr; i++) {
3010 struct ref_update *update = transaction->updates[i];
3012 ret = lock_ref_for_update(refs, update, transaction,
3013 head_ref, &affected_refnames, err);
3018 /* Perform updates first so live commits remain referenced */
3019 for (i = 0; i < transaction->nr; i++) {
3020 struct ref_update *update = transaction->updates[i];
3021 struct ref_lock *lock = update->backend_data;
3023 if (update->flags & REF_NEEDS_COMMIT ||
3024 update->flags & REF_LOG_ONLY) {
3025 if (files_log_ref_write(refs,
3029 update->msg, update->flags,
3031 char *old_msg = strbuf_detach(err, NULL);
3033 strbuf_addf(err, "cannot update the ref '%s': %s",
3034 lock->ref_name, old_msg);
3037 update->backend_data = NULL;
3038 ret = TRANSACTION_GENERIC_ERROR;
3042 if (update->flags & REF_NEEDS_COMMIT) {
3043 clear_loose_ref_cache(refs);
3044 if (commit_ref(lock)) {
3045 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
3047 update->backend_data = NULL;
3048 ret = TRANSACTION_GENERIC_ERROR;
3053 /* Perform deletes now that updates are safely completed */
3054 for (i = 0; i < transaction->nr; i++) {
3055 struct ref_update *update = transaction->updates[i];
3056 struct ref_lock *lock = update->backend_data;
3058 if (update->flags & REF_DELETING &&
3059 !(update->flags & REF_LOG_ONLY)) {
3060 if (!(update->type & REF_ISPACKED) ||
3061 update->type & REF_ISSYMREF) {
3062 /* It is a loose reference. */
3064 files_ref_path(refs, &sb, lock->ref_name);
3065 if (unlink_or_msg(sb.buf, err)) {
3066 ret = TRANSACTION_GENERIC_ERROR;
3069 update->flags |= REF_DELETED_LOOSE;
3072 if (!(update->flags & REF_ISPRUNING))
3073 string_list_append(&refs_to_delete,
3078 if (repack_without_refs(refs, &refs_to_delete, err)) {
3079 ret = TRANSACTION_GENERIC_ERROR;
3083 /* Delete the reflogs of any references that were deleted: */
3084 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
3086 files_reflog_path(refs, &sb, ref_to_delete->string);
3087 if (!unlink_or_warn(sb.buf))
3088 try_remove_empty_parents(refs, ref_to_delete->string,
3089 REMOVE_EMPTY_PARENTS_REFLOG);
3092 clear_loose_ref_cache(refs);
3095 strbuf_release(&sb);
3096 transaction->state = REF_TRANSACTION_CLOSED;
3098 for (i = 0; i < transaction->nr; i++) {
3099 struct ref_update *update = transaction->updates[i];
3100 struct ref_lock *lock = update->backend_data;
3105 if (update->flags & REF_DELETED_LOOSE) {
3107 * The loose reference was deleted. Delete any
3108 * empty parent directories. (Note that this
3109 * can only work because we have already
3110 * removed the lockfile.)
3112 try_remove_empty_parents(refs, update->refname,
3113 REMOVE_EMPTY_PARENTS_REF);
3117 string_list_clear(&refs_to_delete, 0);
3119 string_list_clear(&affected_refnames, 0);
3124 static int ref_present(const char *refname,
3125 const struct object_id *oid, int flags, void *cb_data)
3127 struct string_list *affected_refnames = cb_data;
3129 return string_list_has_string(affected_refnames, refname);
3132 static int files_initial_transaction_commit(struct ref_store *ref_store,
3133 struct ref_transaction *transaction,
3136 struct files_ref_store *refs =
3137 files_downcast(ref_store, REF_STORE_WRITE,
3138 "initial_ref_transaction_commit");
3140 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
3144 if (transaction->state != REF_TRANSACTION_OPEN)
3145 die("BUG: commit called for transaction that is not open");
3147 /* Fail if a refname appears more than once in the transaction: */
3148 for (i = 0; i < transaction->nr; i++)
3149 string_list_append(&affected_refnames,
3150 transaction->updates[i]->refname);
3151 string_list_sort(&affected_refnames);
3152 if (ref_update_reject_duplicates(&affected_refnames, err)) {
3153 ret = TRANSACTION_GENERIC_ERROR;
3158 * It's really undefined to call this function in an active
3159 * repository or when there are existing references: we are
3160 * only locking and changing packed-refs, so (1) any
3161 * simultaneous processes might try to change a reference at
3162 * the same time we do, and (2) any existing loose versions of
3163 * the references that we are setting would have precedence
3164 * over our values. But some remote helpers create the remote
3165 * "HEAD" and "master" branches before calling this function,
3166 * so here we really only check that none of the references
3167 * that we are creating already exists.
3169 if (refs_for_each_rawref(&refs->base, ref_present,
3170 &affected_refnames))
3171 die("BUG: initial ref transaction called with existing refs");
3173 for (i = 0; i < transaction->nr; i++) {
3174 struct ref_update *update = transaction->updates[i];
3176 if ((update->flags & REF_HAVE_OLD) &&
3177 !is_null_sha1(update->old_sha1))
3178 die("BUG: initial ref transaction with old_sha1 set");
3179 if (refs_verify_refname_available(&refs->base, update->refname,
3180 &affected_refnames, NULL,
3182 ret = TRANSACTION_NAME_CONFLICT;
3187 if (lock_packed_refs(refs, 0)) {
3188 strbuf_addf(err, "unable to lock packed-refs file: %s",
3190 ret = TRANSACTION_GENERIC_ERROR;
3194 for (i = 0; i < transaction->nr; i++) {
3195 struct ref_update *update = transaction->updates[i];
3197 if ((update->flags & REF_HAVE_NEW) &&
3198 !is_null_sha1(update->new_sha1))
3199 add_packed_ref(refs, update->refname, update->new_sha1);
3202 if (commit_packed_refs(refs)) {
3203 strbuf_addf(err, "unable to commit packed-refs file: %s",
3205 ret = TRANSACTION_GENERIC_ERROR;
3210 transaction->state = REF_TRANSACTION_CLOSED;
3211 string_list_clear(&affected_refnames, 0);
3215 struct expire_reflog_cb {
3217 reflog_expiry_should_prune_fn *should_prune_fn;
3220 struct object_id last_kept_oid;
3223 static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
3224 const char *email, unsigned long timestamp, int tz,
3225 const char *message, void *cb_data)
3227 struct expire_reflog_cb *cb = cb_data;
3228 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
3230 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
3231 ooid = &cb->last_kept_oid;
3233 if ((*cb->should_prune_fn)(ooid->hash, noid->hash, email, timestamp, tz,
3234 message, policy_cb)) {
3236 printf("would prune %s", message);
3237 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3238 printf("prune %s", message);
3241 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",
3242 oid_to_hex(ooid), oid_to_hex(noid),
3243 email, timestamp, tz, message);
3244 oidcpy(&cb->last_kept_oid, noid);
3246 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3247 printf("keep %s", message);
3252 static int files_reflog_expire(struct ref_store *ref_store,
3253 const char *refname, const unsigned char *sha1,
3255 reflog_expiry_prepare_fn prepare_fn,
3256 reflog_expiry_should_prune_fn should_prune_fn,
3257 reflog_expiry_cleanup_fn cleanup_fn,
3258 void *policy_cb_data)
3260 struct files_ref_store *refs =
3261 files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire");
3262 static struct lock_file reflog_lock;
3263 struct expire_reflog_cb cb;
3264 struct ref_lock *lock;
3265 struct strbuf log_file_sb = STRBUF_INIT;
3269 struct strbuf err = STRBUF_INIT;
3271 memset(&cb, 0, sizeof(cb));
3273 cb.policy_cb = policy_cb_data;
3274 cb.should_prune_fn = should_prune_fn;
3277 * The reflog file is locked by holding the lock on the
3278 * reference itself, plus we might need to update the
3279 * reference if --updateref was specified:
3281 lock = lock_ref_sha1_basic(refs, refname, sha1,
3282 NULL, NULL, REF_NODEREF,
3285 error("cannot lock ref '%s': %s", refname, err.buf);
3286 strbuf_release(&err);
3289 if (!refs_reflog_exists(ref_store, refname)) {
3294 files_reflog_path(refs, &log_file_sb, refname);
3295 log_file = strbuf_detach(&log_file_sb, NULL);
3296 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3298 * Even though holding $GIT_DIR/logs/$reflog.lock has
3299 * no locking implications, we use the lock_file
3300 * machinery here anyway because it does a lot of the
3301 * work we need, including cleaning up if the program
3302 * exits unexpectedly.
3304 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
3305 struct strbuf err = STRBUF_INIT;
3306 unable_to_lock_message(log_file, errno, &err);
3307 error("%s", err.buf);
3308 strbuf_release(&err);
3311 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
3313 error("cannot fdopen %s (%s)",
3314 get_lock_file_path(&reflog_lock), strerror(errno));
3319 (*prepare_fn)(refname, sha1, cb.policy_cb);
3320 refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb);
3321 (*cleanup_fn)(cb.policy_cb);
3323 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3325 * It doesn't make sense to adjust a reference pointed
3326 * to by a symbolic ref based on expiring entries in
3327 * the symbolic reference's reflog. Nor can we update
3328 * a reference if there are no remaining reflog
3331 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
3332 !(type & REF_ISSYMREF) &&
3333 !is_null_oid(&cb.last_kept_oid);
3335 if (close_lock_file(&reflog_lock)) {
3336 status |= error("couldn't write %s: %s", log_file,
3338 } else if (update &&
3339 (write_in_full(get_lock_file_fd(lock->lk),
3340 oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||
3341 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||
3342 close_ref(lock) < 0)) {
3343 status |= error("couldn't write %s",
3344 get_lock_file_path(lock->lk));
3345 rollback_lock_file(&reflog_lock);
3346 } else if (commit_lock_file(&reflog_lock)) {
3347 status |= error("unable to write reflog '%s' (%s)",
3348 log_file, strerror(errno));
3349 } else if (update && commit_ref(lock)) {
3350 status |= error("couldn't set %s", lock->ref_name);
3358 rollback_lock_file(&reflog_lock);
3364 static int files_init_db(struct ref_store *ref_store, struct strbuf *err)
3366 struct files_ref_store *refs =
3367 files_downcast(ref_store, REF_STORE_WRITE, "init_db");
3368 struct strbuf sb = STRBUF_INIT;
3371 * Create .git/refs/{heads,tags}
3373 files_ref_path(refs, &sb, "refs/heads");
3374 safe_create_dir(sb.buf, 1);
3377 files_ref_path(refs, &sb, "refs/tags");
3378 safe_create_dir(sb.buf, 1);
3380 strbuf_release(&sb);
3384 struct ref_storage_be refs_be_files = {
3387 files_ref_store_create,
3389 files_transaction_commit,
3390 files_initial_transaction_commit,
3394 files_create_symref,
3398 files_ref_iterator_begin,
3401 files_reflog_iterator_begin,
3402 files_for_each_reflog_ent,
3403 files_for_each_reflog_ent_reverse,
3404 files_reflog_exists,
3405 files_create_reflog,
3406 files_delete_reflog,