Merge commit 'refs/top-bases/girocco' into girocco
[git/repo.git] / refs.c
blobb6807505e243fd26cae50460bc003254406ae7e5
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
7 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8 #define REF_KNOWS_PEELED 04
10 struct ref_list {
11 struct ref_list *next;
12 unsigned char flag; /* ISSYMREF? ISPACKED? */
13 unsigned char sha1[20];
14 unsigned char peeled[20];
15 char name[FLEX_ARRAY];
18 static const char *parse_ref_line(char *line, unsigned char *sha1)
21 * 42: the answer to everything.
23 * In this case, it happens to be the answer to
24 * 40 (length of sha1 hex representation)
25 * +1 (space in between hex and name)
26 * +1 (newline at the end of the line)
28 int len = strlen(line) - 42;
30 if (len <= 0)
31 return NULL;
32 if (get_sha1_hex(line, sha1) < 0)
33 return NULL;
34 if (!isspace(line[40]))
35 return NULL;
36 line += 41;
37 if (isspace(*line))
38 return NULL;
39 if (line[len] != '\n')
40 return NULL;
41 line[len] = 0;
43 return line;
46 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
47 int flag, struct ref_list *list,
48 struct ref_list **new_entry)
50 int len;
51 struct ref_list *entry;
53 /* Allocate it and add it in.. */
54 len = strlen(name) + 1;
55 entry = xmalloc(sizeof(struct ref_list) + len);
56 hashcpy(entry->sha1, sha1);
57 hashclr(entry->peeled);
58 memcpy(entry->name, name, len);
59 entry->flag = flag;
60 entry->next = list;
61 if (new_entry)
62 *new_entry = entry;
63 return entry;
66 /* merge sort the ref list */
67 static struct ref_list *sort_ref_list(struct ref_list *list)
69 int psize, qsize, last_merge_count, cmp;
70 struct ref_list *p, *q, *l, *e;
71 struct ref_list *new_list = list;
72 int k = 1;
73 int merge_count = 0;
75 if (!list)
76 return list;
78 do {
79 last_merge_count = merge_count;
80 merge_count = 0;
82 psize = 0;
84 p = new_list;
85 q = new_list;
86 new_list = NULL;
87 l = NULL;
89 while (p) {
90 merge_count++;
92 while (psize < k && q->next) {
93 q = q->next;
94 psize++;
96 qsize = k;
98 while ((psize > 0) || (qsize > 0 && q)) {
99 if (qsize == 0 || !q) {
100 e = p;
101 p = p->next;
102 psize--;
103 } else if (psize == 0) {
104 e = q;
105 q = q->next;
106 qsize--;
107 } else {
108 cmp = strcmp(q->name, p->name);
109 if (cmp < 0) {
110 e = q;
111 q = q->next;
112 qsize--;
113 } else if (cmp > 0) {
114 e = p;
115 p = p->next;
116 psize--;
117 } else {
118 if (hashcmp(q->sha1, p->sha1))
119 die("Duplicated ref, and SHA1s don't match: %s",
120 q->name);
121 warning("Duplicated ref: %s", q->name);
122 e = q;
123 q = q->next;
124 qsize--;
125 free(e);
126 e = p;
127 p = p->next;
128 psize--;
132 e->next = NULL;
134 if (l)
135 l->next = e;
136 if (!new_list)
137 new_list = e;
138 l = e;
141 p = q;
144 k = k * 2;
145 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
147 return new_list;
151 * Future: need to be in "struct repository"
152 * when doing a full libification.
154 static struct cached_refs {
155 char did_loose;
156 char did_packed;
157 struct ref_list *loose;
158 struct ref_list *packed;
159 } cached_refs;
160 static struct ref_list *current_ref;
162 static struct ref_list *extra_refs;
164 static void free_ref_list(struct ref_list *list)
166 struct ref_list *next;
167 for ( ; list; list = next) {
168 next = list->next;
169 free(list);
173 static void invalidate_cached_refs(void)
175 struct cached_refs *ca = &cached_refs;
177 if (ca->did_loose && ca->loose)
178 free_ref_list(ca->loose);
179 if (ca->did_packed && ca->packed)
180 free_ref_list(ca->packed);
181 ca->loose = ca->packed = NULL;
182 ca->did_loose = ca->did_packed = 0;
185 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
187 struct ref_list *list = NULL;
188 struct ref_list *last = NULL;
189 char refline[PATH_MAX];
190 int flag = REF_ISPACKED;
192 while (fgets(refline, sizeof(refline), f)) {
193 unsigned char sha1[20];
194 const char *name;
195 static const char header[] = "# pack-refs with:";
197 if (!strncmp(refline, header, sizeof(header)-1)) {
198 const char *traits = refline + sizeof(header) - 1;
199 if (strstr(traits, " peeled "))
200 flag |= REF_KNOWS_PEELED;
201 /* perhaps other traits later as well */
202 continue;
205 name = parse_ref_line(refline, sha1);
206 if (name) {
207 list = add_ref(name, sha1, flag, list, &last);
208 continue;
210 if (last &&
211 refline[0] == '^' &&
212 strlen(refline) == 42 &&
213 refline[41] == '\n' &&
214 !get_sha1_hex(refline + 1, sha1))
215 hashcpy(last->peeled, sha1);
217 cached_refs->packed = sort_ref_list(list);
220 void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
222 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
225 void clear_extra_refs(void)
227 free_ref_list(extra_refs);
228 extra_refs = NULL;
231 static struct ref_list *get_packed_refs(void)
233 if (!cached_refs.did_packed) {
234 FILE *f = fopen(git_path("packed-refs"), "r");
235 cached_refs.packed = NULL;
236 if (f) {
237 read_packed_refs(f, &cached_refs);
238 fclose(f);
240 cached_refs.did_packed = 1;
242 return cached_refs.packed;
245 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
247 DIR *dir = opendir(git_path("%s", base));
249 if (dir) {
250 struct dirent *de;
251 int baselen = strlen(base);
252 char *ref = xmalloc(baselen + 257);
254 memcpy(ref, base, baselen);
255 if (baselen && base[baselen-1] != '/')
256 ref[baselen++] = '/';
258 while ((de = readdir(dir)) != NULL) {
259 unsigned char sha1[20];
260 struct stat st;
261 int flag;
262 int namelen;
264 if (de->d_name[0] == '.')
265 continue;
266 namelen = strlen(de->d_name);
267 if (namelen > 255)
268 continue;
269 if (has_extension(de->d_name, ".lock"))
270 continue;
271 memcpy(ref + baselen, de->d_name, namelen+1);
272 if (stat(git_path("%s", ref), &st) < 0)
273 continue;
274 if (S_ISDIR(st.st_mode)) {
275 list = get_ref_dir(ref, list);
276 continue;
278 if (!resolve_ref(ref, sha1, 1, &flag)) {
279 error("%s points nowhere!", ref);
280 continue;
282 list = add_ref(ref, sha1, flag, list, NULL);
284 free(ref);
285 closedir(dir);
287 return sort_ref_list(list);
290 static struct ref_list *get_loose_refs(void)
292 if (!cached_refs.did_loose) {
293 cached_refs.loose = get_ref_dir("refs", NULL);
294 cached_refs.did_loose = 1;
296 return cached_refs.loose;
299 /* We allow "recursive" symbolic refs. Only within reason, though */
300 #define MAXDEPTH 5
301 #define MAXREFLEN (1024)
303 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
305 FILE *f;
306 struct cached_refs refs;
307 struct ref_list *ref;
308 int retval;
310 strcpy(name + pathlen, "packed-refs");
311 f = fopen(name, "r");
312 if (!f)
313 return -1;
314 read_packed_refs(f, &refs);
315 fclose(f);
316 ref = refs.packed;
317 retval = -1;
318 while (ref) {
319 if (!strcmp(ref->name, refname)) {
320 retval = 0;
321 memcpy(result, ref->sha1, 20);
322 break;
324 ref = ref->next;
326 free_ref_list(refs.packed);
327 return retval;
330 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
332 int fd, len = strlen(refname);
333 char buffer[128], *p;
335 if (recursion > MAXDEPTH || len > MAXREFLEN)
336 return -1;
337 memcpy(name + pathlen, refname, len+1);
338 fd = open(name, O_RDONLY);
339 if (fd < 0)
340 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
342 len = read(fd, buffer, sizeof(buffer)-1);
343 close(fd);
344 if (len < 0)
345 return -1;
346 while (len && isspace(buffer[len-1]))
347 len--;
348 buffer[len] = 0;
350 /* Was it a detached head or an old-fashioned symlink? */
351 if (!get_sha1_hex(buffer, result))
352 return 0;
354 /* Symref? */
355 if (strncmp(buffer, "ref:", 4))
356 return -1;
357 p = buffer + 4;
358 while (isspace(*p))
359 p++;
361 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
364 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
366 int len = strlen(path), retval;
367 char *gitdir;
368 const char *tmp;
370 while (len && path[len-1] == '/')
371 len--;
372 if (!len)
373 return -1;
374 gitdir = xmalloc(len + MAXREFLEN + 8);
375 memcpy(gitdir, path, len);
376 memcpy(gitdir + len, "/.git", 6);
377 len += 5;
379 tmp = read_gitfile_gently(gitdir);
380 if (tmp) {
381 free(gitdir);
382 len = strlen(tmp);
383 gitdir = xmalloc(len + MAXREFLEN + 3);
384 memcpy(gitdir, tmp, len);
386 gitdir[len] = '/';
387 gitdir[++len] = '\0';
388 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
389 free(gitdir);
390 return retval;
394 * If the "reading" argument is set, this function finds out what _object_
395 * the ref points at by "reading" the ref. The ref, if it is not symbolic,
396 * has to exist, and if it is symbolic, it has to point at an existing ref,
397 * because the "read" goes through the symref to the ref it points at.
399 * The access that is not "reading" may often be "writing", but does not
400 * have to; it can be merely checking _where it leads to_. If it is a
401 * prelude to "writing" to the ref, a write to a symref that points at
402 * yet-to-be-born ref will create the real ref pointed by the symref.
403 * reading=0 allows the caller to check where such a symref leads to.
405 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
407 int depth = MAXDEPTH;
408 ssize_t len;
409 char buffer[256];
410 static char ref_buffer[256];
412 if (flag)
413 *flag = 0;
415 for (;;) {
416 const char *path = git_path("%s", ref);
417 struct stat st;
418 char *buf;
419 int fd;
421 if (--depth < 0)
422 return NULL;
424 /* Special case: non-existing file. */
425 if (lstat(path, &st) < 0) {
426 struct ref_list *list = get_packed_refs();
427 while (list) {
428 if (!strcmp(ref, list->name)) {
429 hashcpy(sha1, list->sha1);
430 if (flag)
431 *flag |= REF_ISPACKED;
432 return ref;
434 list = list->next;
436 if (reading || errno != ENOENT)
437 return NULL;
438 hashclr(sha1);
439 return ref;
442 /* Follow "normalized" - ie "refs/.." symlinks by hand */
443 if (S_ISLNK(st.st_mode)) {
444 len = readlink(path, buffer, sizeof(buffer)-1);
445 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
446 buffer[len] = 0;
447 strcpy(ref_buffer, buffer);
448 ref = ref_buffer;
449 if (flag)
450 *flag |= REF_ISSYMREF;
451 continue;
455 /* Is it a directory? */
456 if (S_ISDIR(st.st_mode)) {
457 errno = EISDIR;
458 return NULL;
462 * Anything else, just open it and try to use it as
463 * a ref
465 fd = open(path, O_RDONLY);
466 if (fd < 0)
467 return NULL;
468 len = read_in_full(fd, buffer, sizeof(buffer)-1);
469 close(fd);
472 * Is it a symbolic ref?
474 if (len < 4 || memcmp("ref:", buffer, 4))
475 break;
476 buf = buffer + 4;
477 len -= 4;
478 while (len && isspace(*buf))
479 buf++, len--;
480 while (len && isspace(buf[len-1]))
481 len--;
482 buf[len] = 0;
483 memcpy(ref_buffer, buf, len + 1);
484 ref = ref_buffer;
485 if (flag)
486 *flag |= REF_ISSYMREF;
488 if (len < 40 || get_sha1_hex(buffer, sha1))
489 return NULL;
490 return ref;
493 int read_ref(const char *ref, unsigned char *sha1)
495 if (resolve_ref(ref, sha1, 1, NULL))
496 return 0;
497 return -1;
500 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
501 void *cb_data, struct ref_list *entry)
503 if (strncmp(base, entry->name, trim))
504 return 0;
505 if (is_null_sha1(entry->sha1))
506 return 0;
507 if (!has_sha1_file(entry->sha1)) {
508 error("%s does not point to a valid object!", entry->name);
509 return 0;
511 current_ref = entry;
512 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
515 int peel_ref(const char *ref, unsigned char *sha1)
517 int flag;
518 unsigned char base[20];
519 struct object *o;
521 if (current_ref && (current_ref->name == ref
522 || !strcmp(current_ref->name, ref))) {
523 if (current_ref->flag & REF_KNOWS_PEELED) {
524 hashcpy(sha1, current_ref->peeled);
525 return 0;
527 hashcpy(base, current_ref->sha1);
528 goto fallback;
531 if (!resolve_ref(ref, base, 1, &flag))
532 return -1;
534 if ((flag & REF_ISPACKED)) {
535 struct ref_list *list = get_packed_refs();
537 while (list) {
538 if (!strcmp(list->name, ref)) {
539 if (list->flag & REF_KNOWS_PEELED) {
540 hashcpy(sha1, list->peeled);
541 return 0;
543 /* older pack-refs did not leave peeled ones */
544 break;
546 list = list->next;
550 fallback:
551 o = parse_object(base);
552 if (o && o->type == OBJ_TAG) {
553 o = deref_tag(o, ref, 0);
554 if (o) {
555 hashcpy(sha1, o->sha1);
556 return 0;
559 return -1;
562 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
563 void *cb_data)
565 int retval = 0;
566 struct ref_list *packed = get_packed_refs();
567 struct ref_list *loose = get_loose_refs();
569 struct ref_list *extra;
571 for (extra = extra_refs; extra; extra = extra->next)
572 retval = do_one_ref(base, fn, trim, cb_data, extra);
574 while (packed && loose) {
575 struct ref_list *entry;
576 int cmp = strcmp(packed->name, loose->name);
577 if (!cmp) {
578 packed = packed->next;
579 continue;
581 if (cmp > 0) {
582 entry = loose;
583 loose = loose->next;
584 } else {
585 entry = packed;
586 packed = packed->next;
588 retval = do_one_ref(base, fn, trim, cb_data, entry);
589 if (retval)
590 goto end_each;
593 for (packed = packed ? packed : loose; packed; packed = packed->next) {
594 retval = do_one_ref(base, fn, trim, cb_data, packed);
595 if (retval)
596 goto end_each;
599 end_each:
600 current_ref = NULL;
601 return retval;
604 int head_ref(each_ref_fn fn, void *cb_data)
606 unsigned char sha1[20];
607 int flag;
609 if (resolve_ref("HEAD", sha1, 1, &flag))
610 return fn("HEAD", sha1, flag, cb_data);
611 return 0;
614 int for_each_ref(each_ref_fn fn, void *cb_data)
616 return do_for_each_ref("refs/", fn, 0, cb_data);
619 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
621 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
624 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
626 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
629 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
631 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
635 * Make sure "ref" is something reasonable to have under ".git/refs/";
636 * We do not like it if:
638 * - any path component of it begins with ".", or
639 * - it has double dots "..", or
640 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
641 * - it ends with a "/".
644 static inline int bad_ref_char(int ch)
646 if (((unsigned) ch) <= ' ' ||
647 ch == '~' || ch == '^' || ch == ':')
648 return 1;
649 /* 2.13 Pattern Matching Notation */
650 if (ch == '?' || ch == '[') /* Unsupported */
651 return 1;
652 if (ch == '*') /* Supported at the end */
653 return 2;
654 return 0;
657 int check_ref_format(const char *ref)
659 int ch, level, bad_type;
660 const char *cp = ref;
662 level = 0;
663 while (1) {
664 while ((ch = *cp++) == '/')
665 ; /* tolerate duplicated slashes */
666 if (!ch)
667 /* should not end with slashes */
668 return CHECK_REF_FORMAT_ERROR;
670 /* we are at the beginning of the path component */
671 if (ch == '.')
672 return CHECK_REF_FORMAT_ERROR;
673 bad_type = bad_ref_char(ch);
674 if (bad_type) {
675 return (bad_type == 2 && !*cp)
676 ? CHECK_REF_FORMAT_WILDCARD
677 : CHECK_REF_FORMAT_ERROR;
680 /* scan the rest of the path component */
681 while ((ch = *cp++) != 0) {
682 bad_type = bad_ref_char(ch);
683 if (bad_type) {
684 return (bad_type == 2 && !*cp)
685 ? CHECK_REF_FORMAT_WILDCARD
686 : CHECK_REF_FORMAT_ERROR;
688 if (ch == '/')
689 break;
690 if (ch == '.' && *cp == '.')
691 return CHECK_REF_FORMAT_ERROR;
693 level++;
694 if (!ch) {
695 if (level < 2)
696 return CHECK_REF_FORMAT_ONELEVEL;
697 return CHECK_REF_FORMAT_OK;
702 const char *ref_rev_parse_rules[] = {
703 "%.*s",
704 "refs/%.*s",
705 "refs/tags/%.*s",
706 "refs/heads/%.*s",
707 "refs/remotes/%.*s",
708 "refs/remotes/%.*s/HEAD",
709 NULL
712 const char *ref_fetch_rules[] = {
713 "%.*s",
714 "refs/%.*s",
715 "refs/heads/%.*s",
716 NULL
719 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
721 const char **p;
722 const int abbrev_name_len = strlen(abbrev_name);
724 for (p = rules; *p; p++) {
725 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
726 return 1;
730 return 0;
733 static struct ref_lock *verify_lock(struct ref_lock *lock,
734 const unsigned char *old_sha1, int mustexist)
736 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
737 error("Can't verify ref %s", lock->ref_name);
738 unlock_ref(lock);
739 return NULL;
741 if (hashcmp(lock->old_sha1, old_sha1)) {
742 error("Ref %s is at %s but expected %s", lock->ref_name,
743 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
744 unlock_ref(lock);
745 return NULL;
747 return lock;
750 static int remove_empty_directories(const char *file)
752 /* we want to create a file but there is a directory there;
753 * if that is an empty directory (or a directory that contains
754 * only empty directories), remove them.
756 struct strbuf path;
757 int result;
759 strbuf_init(&path, 20);
760 strbuf_addstr(&path, file);
762 result = remove_dir_recursively(&path, 1);
764 strbuf_release(&path);
766 return result;
769 static int is_refname_available(const char *ref, const char *oldref,
770 struct ref_list *list, int quiet)
772 int namlen = strlen(ref); /* e.g. 'foo/bar' */
773 while (list) {
774 /* list->name could be 'foo' or 'foo/bar/baz' */
775 if (!oldref || strcmp(oldref, list->name)) {
776 int len = strlen(list->name);
777 int cmplen = (namlen < len) ? namlen : len;
778 const char *lead = (namlen < len) ? list->name : ref;
779 if (!strncmp(ref, list->name, cmplen) &&
780 lead[cmplen] == '/') {
781 if (!quiet)
782 error("'%s' exists; cannot create '%s'",
783 list->name, ref);
784 return 0;
787 list = list->next;
789 return 1;
792 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
794 char *ref_file;
795 const char *orig_ref = ref;
796 struct ref_lock *lock;
797 struct stat st;
798 int last_errno = 0;
799 int type;
800 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
802 lock = xcalloc(1, sizeof(struct ref_lock));
803 lock->lock_fd = -1;
805 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
806 if (!ref && errno == EISDIR) {
807 /* we are trying to lock foo but we used to
808 * have foo/bar which now does not exist;
809 * it is normal for the empty directory 'foo'
810 * to remain.
812 ref_file = git_path("%s", orig_ref);
813 if (remove_empty_directories(ref_file)) {
814 last_errno = errno;
815 error("there are still refs under '%s'", orig_ref);
816 goto error_return;
818 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
820 if (type_p)
821 *type_p = type;
822 if (!ref) {
823 last_errno = errno;
824 error("unable to resolve reference %s: %s",
825 orig_ref, strerror(errno));
826 goto error_return;
828 /* When the ref did not exist and we are creating it,
829 * make sure there is no existing ref that is packed
830 * whose name begins with our refname, nor a ref whose
831 * name is a proper prefix of our refname.
833 if (is_null_sha1(lock->old_sha1) &&
834 !is_refname_available(ref, NULL, get_packed_refs(), 0))
835 goto error_return;
837 lock->lk = xcalloc(1, sizeof(struct lock_file));
839 if (flags & REF_NODEREF)
840 ref = orig_ref;
841 lock->ref_name = xstrdup(ref);
842 lock->orig_ref_name = xstrdup(orig_ref);
843 ref_file = git_path("%s", ref);
844 if (lstat(ref_file, &st) && errno == ENOENT)
845 lock->force_write = 1;
846 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
847 lock->force_write = 1;
849 if (safe_create_leading_directories(ref_file)) {
850 last_errno = errno;
851 error("unable to create directory for %s", ref_file);
852 goto error_return;
854 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
856 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
858 error_return:
859 unlock_ref(lock);
860 errno = last_errno;
861 return NULL;
864 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
866 char refpath[PATH_MAX];
867 if (check_ref_format(ref))
868 return NULL;
869 strcpy(refpath, mkpath("refs/%s", ref));
870 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
873 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
875 switch (check_ref_format(ref)) {
876 default:
877 return NULL;
878 case 0:
879 case CHECK_REF_FORMAT_ONELEVEL:
880 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
884 static struct lock_file packlock;
886 static int repack_without_ref(const char *refname)
888 struct ref_list *list, *packed_ref_list;
889 int fd;
890 int found = 0;
892 packed_ref_list = get_packed_refs();
893 for (list = packed_ref_list; list; list = list->next) {
894 if (!strcmp(refname, list->name)) {
895 found = 1;
896 break;
899 if (!found)
900 return 0;
901 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
902 if (fd < 0)
903 return error("cannot delete '%s' from packed refs", refname);
905 for (list = packed_ref_list; list; list = list->next) {
906 char line[PATH_MAX + 100];
907 int len;
909 if (!strcmp(refname, list->name))
910 continue;
911 len = snprintf(line, sizeof(line), "%s %s\n",
912 sha1_to_hex(list->sha1), list->name);
913 /* this should not happen but just being defensive */
914 if (len > sizeof(line))
915 die("too long a refname '%s'", list->name);
916 write_or_die(fd, line, len);
918 return commit_lock_file(&packlock);
921 int delete_ref(const char *refname, const unsigned char *sha1)
923 struct ref_lock *lock;
924 int err, i, ret = 0, flag = 0;
926 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
927 if (!lock)
928 return 1;
929 if (!(flag & REF_ISPACKED)) {
930 /* loose */
931 i = strlen(lock->lk->filename) - 5; /* .lock */
932 lock->lk->filename[i] = 0;
933 err = unlink(lock->lk->filename);
934 if (err && errno != ENOENT) {
935 ret = 1;
936 error("unlink(%s) failed: %s",
937 lock->lk->filename, strerror(errno));
939 lock->lk->filename[i] = '.';
941 /* removing the loose one could have resurrected an earlier
942 * packed one. Also, if it was not loose we need to repack
943 * without it.
945 ret |= repack_without_ref(refname);
947 err = unlink(git_path("logs/%s", lock->ref_name));
948 if (err && errno != ENOENT)
949 fprintf(stderr, "warning: unlink(%s) failed: %s",
950 git_path("logs/%s", lock->ref_name), strerror(errno));
951 invalidate_cached_refs();
952 unlock_ref(lock);
953 return ret;
956 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
958 static const char renamed_ref[] = "RENAMED-REF";
959 unsigned char sha1[20], orig_sha1[20];
960 int flag = 0, logmoved = 0;
961 struct ref_lock *lock;
962 struct stat loginfo;
963 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
965 if (S_ISLNK(loginfo.st_mode))
966 return error("reflog for %s is a symlink", oldref);
968 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
969 return error("refname %s not found", oldref);
971 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
972 return 1;
974 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
975 return 1;
977 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
978 if (!lock)
979 return error("unable to lock %s", renamed_ref);
980 lock->force_write = 1;
981 if (write_ref_sha1(lock, orig_sha1, logmsg))
982 return error("unable to save current sha1 in %s", renamed_ref);
984 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
985 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
986 oldref, strerror(errno));
988 if (delete_ref(oldref, orig_sha1)) {
989 error("unable to delete old %s", oldref);
990 goto rollback;
993 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
994 if (errno==EISDIR) {
995 if (remove_empty_directories(git_path("%s", newref))) {
996 error("Directory not empty: %s", newref);
997 goto rollback;
999 } else {
1000 error("unable to delete existing %s", newref);
1001 goto rollback;
1005 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1006 error("unable to create directory for %s", newref);
1007 goto rollback;
1010 retry:
1011 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
1012 if (errno==EISDIR || errno==ENOTDIR) {
1014 * rename(a, b) when b is an existing
1015 * directory ought to result in ISDIR, but
1016 * Solaris 5.8 gives ENOTDIR. Sheesh.
1018 if (remove_empty_directories(git_path("logs/%s", newref))) {
1019 error("Directory not empty: logs/%s", newref);
1020 goto rollback;
1022 goto retry;
1023 } else {
1024 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
1025 newref, strerror(errno));
1026 goto rollback;
1029 logmoved = log;
1031 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1032 if (!lock) {
1033 error("unable to lock %s for update", newref);
1034 goto rollback;
1037 lock->force_write = 1;
1038 hashcpy(lock->old_sha1, orig_sha1);
1039 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1040 error("unable to write current sha1 into %s", newref);
1041 goto rollback;
1044 return 0;
1046 rollback:
1047 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1048 if (!lock) {
1049 error("unable to lock %s for rollback", oldref);
1050 goto rollbacklog;
1053 lock->force_write = 1;
1054 flag = log_all_ref_updates;
1055 log_all_ref_updates = 0;
1056 if (write_ref_sha1(lock, orig_sha1, NULL))
1057 error("unable to write current sha1 into %s", oldref);
1058 log_all_ref_updates = flag;
1060 rollbacklog:
1061 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1062 error("unable to restore logfile %s from %s: %s",
1063 oldref, newref, strerror(errno));
1064 if (!logmoved && log &&
1065 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1066 error("unable to restore logfile %s from tmp-renamed-log: %s",
1067 oldref, strerror(errno));
1069 return 1;
1072 int close_ref(struct ref_lock *lock)
1074 if (close_lock_file(lock->lk))
1075 return -1;
1076 lock->lock_fd = -1;
1077 return 0;
1080 int commit_ref(struct ref_lock *lock)
1082 if (commit_lock_file(lock->lk))
1083 return -1;
1084 lock->lock_fd = -1;
1085 return 0;
1088 void unlock_ref(struct ref_lock *lock)
1090 /* Do not free lock->lk -- atexit() still looks at them */
1091 if (lock->lk)
1092 rollback_lock_file(lock->lk);
1093 free(lock->ref_name);
1094 free(lock->orig_ref_name);
1095 free(lock);
1099 * copy the reflog message msg to buf, which has been allocated sufficiently
1100 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1101 * because reflog file is one line per entry.
1103 static int copy_msg(char *buf, const char *msg)
1105 char *cp = buf;
1106 char c;
1107 int wasspace = 1;
1109 *cp++ = '\t';
1110 while ((c = *msg++)) {
1111 if (wasspace && isspace(c))
1112 continue;
1113 wasspace = isspace(c);
1114 if (wasspace)
1115 c = ' ';
1116 *cp++ = c;
1118 while (buf < cp && isspace(cp[-1]))
1119 cp--;
1120 *cp++ = '\n';
1121 return cp - buf;
1124 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1125 const unsigned char *new_sha1, const char *msg)
1127 int logfd, written, oflags = O_APPEND | O_WRONLY;
1128 unsigned maxlen, len;
1129 int msglen;
1130 char *log_file, *logrec;
1131 const char *committer;
1133 if (log_all_ref_updates < 0)
1134 log_all_ref_updates = !is_bare_repository();
1136 log_file = git_path("logs/%s", ref_name);
1138 if (log_all_ref_updates &&
1139 (!prefixcmp(ref_name, "refs/heads/") ||
1140 !prefixcmp(ref_name, "refs/remotes/") ||
1141 !strcmp(ref_name, "HEAD"))) {
1142 if (safe_create_leading_directories(log_file) < 0)
1143 return error("unable to create directory for %s",
1144 log_file);
1145 oflags |= O_CREAT;
1148 logfd = open(log_file, oflags, 0666);
1149 if (logfd < 0) {
1150 if (!(oflags & O_CREAT) && errno == ENOENT)
1151 return 0;
1153 if ((oflags & O_CREAT) && errno == EISDIR) {
1154 if (remove_empty_directories(log_file)) {
1155 return error("There are still logs under '%s'",
1156 log_file);
1158 logfd = open(log_file, oflags, 0666);
1161 if (logfd < 0)
1162 return error("Unable to append to %s: %s",
1163 log_file, strerror(errno));
1166 adjust_shared_perm(log_file);
1168 msglen = msg ? strlen(msg) : 0;
1169 committer = git_committer_info(0);
1170 maxlen = strlen(committer) + msglen + 100;
1171 logrec = xmalloc(maxlen);
1172 len = sprintf(logrec, "%s %s %s\n",
1173 sha1_to_hex(old_sha1),
1174 sha1_to_hex(new_sha1),
1175 committer);
1176 if (msglen)
1177 len += copy_msg(logrec + len - 1, msg) - 1;
1178 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1179 free(logrec);
1180 if (close(logfd) != 0 || written != len)
1181 return error("Unable to append to %s", log_file);
1182 return 0;
1185 static int is_branch(const char *refname)
1187 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1190 int write_ref_sha1(struct ref_lock *lock,
1191 const unsigned char *sha1, const char *logmsg)
1193 static char term = '\n';
1194 struct object *o;
1196 if (!lock)
1197 return -1;
1198 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1199 unlock_ref(lock);
1200 return 0;
1202 o = parse_object(sha1);
1203 if (!o) {
1204 error("Trying to write ref %s with nonexistant object %s",
1205 lock->ref_name, sha1_to_hex(sha1));
1206 unlock_ref(lock);
1207 return -1;
1209 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1210 error("Trying to write non-commit object %s to branch %s",
1211 sha1_to_hex(sha1), lock->ref_name);
1212 unlock_ref(lock);
1213 return -1;
1215 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1216 write_in_full(lock->lock_fd, &term, 1) != 1
1217 || close_ref(lock) < 0) {
1218 error("Couldn't write %s", lock->lk->filename);
1219 unlock_ref(lock);
1220 return -1;
1222 invalidate_cached_refs();
1223 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1224 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1225 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1226 unlock_ref(lock);
1227 return -1;
1229 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1231 * Special hack: If a branch is updated directly and HEAD
1232 * points to it (may happen on the remote side of a push
1233 * for example) then logically the HEAD reflog should be
1234 * updated too.
1235 * A generic solution implies reverse symref information,
1236 * but finding all symrefs pointing to the given branch
1237 * would be rather costly for this rare event (the direct
1238 * update of a branch) to be worth it. So let's cheat and
1239 * check with HEAD only which should cover 99% of all usage
1240 * scenarios (even 100% of the default ones).
1242 unsigned char head_sha1[20];
1243 int head_flag;
1244 const char *head_ref;
1245 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1246 if (head_ref && (head_flag & REF_ISSYMREF) &&
1247 !strcmp(head_ref, lock->ref_name))
1248 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1250 if (commit_ref(lock)) {
1251 error("Couldn't set %s", lock->ref_name);
1252 unlock_ref(lock);
1253 return -1;
1255 unlock_ref(lock);
1256 return 0;
1259 int create_symref(const char *ref_target, const char *refs_heads_master,
1260 const char *logmsg)
1262 const char *lockpath;
1263 char ref[1000];
1264 int fd, len, written;
1265 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1266 unsigned char old_sha1[20], new_sha1[20];
1268 if (logmsg && read_ref(ref_target, old_sha1))
1269 hashclr(old_sha1);
1271 if (safe_create_leading_directories(git_HEAD) < 0)
1272 return error("unable to create directory for %s", git_HEAD);
1274 #ifndef NO_SYMLINK_HEAD
1275 if (prefer_symlink_refs) {
1276 unlink(git_HEAD);
1277 if (!symlink(refs_heads_master, git_HEAD))
1278 goto done;
1279 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1281 #endif
1283 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1284 if (sizeof(ref) <= len) {
1285 error("refname too long: %s", refs_heads_master);
1286 goto error_free_return;
1288 lockpath = mkpath("%s.lock", git_HEAD);
1289 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1290 if (fd < 0) {
1291 error("Unable to open %s for writing", lockpath);
1292 goto error_free_return;
1294 written = write_in_full(fd, ref, len);
1295 if (close(fd) != 0 || written != len) {
1296 error("Unable to write to %s", lockpath);
1297 goto error_unlink_return;
1299 if (rename(lockpath, git_HEAD) < 0) {
1300 error("Unable to create %s", git_HEAD);
1301 goto error_unlink_return;
1303 if (adjust_shared_perm(git_HEAD)) {
1304 error("Unable to fix permissions on %s", lockpath);
1305 error_unlink_return:
1306 unlink(lockpath);
1307 error_free_return:
1308 free(git_HEAD);
1309 return -1;
1312 #ifndef NO_SYMLINK_HEAD
1313 done:
1314 #endif
1315 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1316 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1318 free(git_HEAD);
1319 return 0;
1322 static char *ref_msg(const char *line, const char *endp)
1324 const char *ep;
1325 line += 82;
1326 ep = memchr(line, '\n', endp - line);
1327 if (!ep)
1328 ep = endp;
1329 return xmemdupz(line, ep - line);
1332 int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
1334 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1335 char *tz_c;
1336 int logfd, tz, reccnt = 0;
1337 struct stat st;
1338 unsigned long date;
1339 unsigned char logged_sha1[20];
1340 void *log_mapped;
1341 size_t mapsz;
1343 logfile = git_path("logs/%s", ref);
1344 logfd = open(logfile, O_RDONLY, 0);
1345 if (logfd < 0)
1346 die("Unable to read log %s: %s", logfile, strerror(errno));
1347 fstat(logfd, &st);
1348 if (!st.st_size)
1349 die("Log %s is empty.", logfile);
1350 mapsz = xsize_t(st.st_size);
1351 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1352 logdata = log_mapped;
1353 close(logfd);
1355 lastrec = NULL;
1356 rec = logend = logdata + st.st_size;
1357 while (logdata < rec) {
1358 reccnt++;
1359 if (logdata < rec && *(rec-1) == '\n')
1360 rec--;
1361 lastgt = NULL;
1362 while (logdata < rec && *(rec-1) != '\n') {
1363 rec--;
1364 if (*rec == '>')
1365 lastgt = rec;
1367 if (!lastgt)
1368 die("Log %s is corrupt.", logfile);
1369 date = strtoul(lastgt + 1, &tz_c, 10);
1370 if (date <= at_time || cnt == 0) {
1371 tz = strtoul(tz_c, NULL, 10);
1372 if (msg)
1373 *msg = ref_msg(rec, logend);
1374 if (cutoff_time)
1375 *cutoff_time = date;
1376 if (cutoff_tz)
1377 *cutoff_tz = tz;
1378 if (cutoff_cnt)
1379 *cutoff_cnt = reccnt - 1;
1380 if (lastrec) {
1381 if (get_sha1_hex(lastrec, logged_sha1))
1382 die("Log %s is corrupt.", logfile);
1383 if (get_sha1_hex(rec + 41, sha1))
1384 die("Log %s is corrupt.", logfile);
1385 if (hashcmp(logged_sha1, sha1)) {
1386 fprintf(stderr,
1387 "warning: Log %s has gap after %s.\n",
1388 logfile, show_date(date, tz, DATE_RFC2822));
1391 else if (date == at_time) {
1392 if (get_sha1_hex(rec + 41, sha1))
1393 die("Log %s is corrupt.", logfile);
1395 else {
1396 if (get_sha1_hex(rec + 41, logged_sha1))
1397 die("Log %s is corrupt.", logfile);
1398 if (hashcmp(logged_sha1, sha1)) {
1399 fprintf(stderr,
1400 "warning: Log %s unexpectedly ended on %s.\n",
1401 logfile, show_date(date, tz, DATE_RFC2822));
1404 munmap(log_mapped, mapsz);
1405 return 0;
1407 lastrec = rec;
1408 if (cnt > 0)
1409 cnt--;
1412 rec = logdata;
1413 while (rec < logend && *rec != '>' && *rec != '\n')
1414 rec++;
1415 if (rec == logend || *rec == '\n')
1416 die("Log %s is corrupt.", logfile);
1417 date = strtoul(rec + 1, &tz_c, 10);
1418 tz = strtoul(tz_c, NULL, 10);
1419 if (get_sha1_hex(logdata, sha1))
1420 die("Log %s is corrupt.", logfile);
1421 if (is_null_sha1(sha1)) {
1422 if (get_sha1_hex(logdata + 41, sha1))
1423 die("Log %s is corrupt.", logfile);
1425 if (msg)
1426 *msg = ref_msg(logdata, logend);
1427 munmap(log_mapped, mapsz);
1429 if (cutoff_time)
1430 *cutoff_time = date;
1431 if (cutoff_tz)
1432 *cutoff_tz = tz;
1433 if (cutoff_cnt)
1434 *cutoff_cnt = reccnt;
1435 return 1;
1438 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1440 const char *logfile;
1441 FILE *logfp;
1442 char buf[1024];
1443 int ret = 0;
1445 logfile = git_path("logs/%s", ref);
1446 logfp = fopen(logfile, "r");
1447 if (!logfp)
1448 return -1;
1449 while (fgets(buf, sizeof(buf), logfp)) {
1450 unsigned char osha1[20], nsha1[20];
1451 char *email_end, *message;
1452 unsigned long timestamp;
1453 int len, tz;
1455 /* old SP new SP name <email> SP time TAB msg LF */
1456 len = strlen(buf);
1457 if (len < 83 || buf[len-1] != '\n' ||
1458 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1459 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1460 !(email_end = strchr(buf + 82, '>')) ||
1461 email_end[1] != ' ' ||
1462 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1463 !message || message[0] != ' ' ||
1464 (message[1] != '+' && message[1] != '-') ||
1465 !isdigit(message[2]) || !isdigit(message[3]) ||
1466 !isdigit(message[4]) || !isdigit(message[5]))
1467 continue; /* corrupt? */
1468 email_end[1] = '\0';
1469 tz = strtol(message + 1, NULL, 10);
1470 if (message[6] != '\t')
1471 message += 6;
1472 else
1473 message += 7;
1474 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1475 if (ret)
1476 break;
1478 fclose(logfp);
1479 return ret;
1482 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1484 DIR *dir = opendir(git_path("logs/%s", base));
1485 int retval = 0;
1487 if (dir) {
1488 struct dirent *de;
1489 int baselen = strlen(base);
1490 char *log = xmalloc(baselen + 257);
1492 memcpy(log, base, baselen);
1493 if (baselen && base[baselen-1] != '/')
1494 log[baselen++] = '/';
1496 while ((de = readdir(dir)) != NULL) {
1497 struct stat st;
1498 int namelen;
1500 if (de->d_name[0] == '.')
1501 continue;
1502 namelen = strlen(de->d_name);
1503 if (namelen > 255)
1504 continue;
1505 if (has_extension(de->d_name, ".lock"))
1506 continue;
1507 memcpy(log + baselen, de->d_name, namelen+1);
1508 if (stat(git_path("logs/%s", log), &st) < 0)
1509 continue;
1510 if (S_ISDIR(st.st_mode)) {
1511 retval = do_for_each_reflog(log, fn, cb_data);
1512 } else {
1513 unsigned char sha1[20];
1514 if (!resolve_ref(log, sha1, 0, NULL))
1515 retval = error("bad ref for %s", log);
1516 else
1517 retval = fn(log, sha1, 0, cb_data);
1519 if (retval)
1520 break;
1522 free(log);
1523 closedir(dir);
1525 else if (*base)
1526 return errno;
1527 return retval;
1530 int for_each_reflog(each_ref_fn fn, void *cb_data)
1532 return do_for_each_reflog("", fn, cb_data);
1535 int update_ref(const char *action, const char *refname,
1536 const unsigned char *sha1, const unsigned char *oldval,
1537 int flags, enum action_on_err onerr)
1539 static struct ref_lock *lock;
1540 lock = lock_any_ref_for_update(refname, oldval, flags);
1541 if (!lock) {
1542 const char *str = "Cannot lock the ref '%s'.";
1543 switch (onerr) {
1544 case MSG_ON_ERR: error(str, refname); break;
1545 case DIE_ON_ERR: die(str, refname); break;
1546 case QUIET_ON_ERR: break;
1548 return 1;
1550 if (write_ref_sha1(lock, sha1, action) < 0) {
1551 const char *str = "Cannot update the ref '%s'.";
1552 switch (onerr) {
1553 case MSG_ON_ERR: error(str, refname); break;
1554 case DIE_ON_ERR: die(str, refname); break;
1555 case QUIET_ON_ERR: break;
1557 return 1;
1559 return 0;
1562 struct ref *find_ref_by_name(struct ref *list, const char *name)
1564 for ( ; list; list = list->next)
1565 if (!strcmp(list->name, name))
1566 return list;
1567 return NULL;