refs.c: add a function to sort a ref list, rather then sorting on add
[git/git.git] / refs.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5
6 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
7 #define REF_KNOWS_PEELED 04
8
9 struct ref_list {
10 struct ref_list *next;
11 unsigned char flag; /* ISSYMREF? ISPACKED? */
12 unsigned char sha1[20];
13 unsigned char peeled[20];
14 char name[FLEX_ARRAY];
15 };
16
17 static const char *parse_ref_line(char *line, unsigned char *sha1)
18 {
19 /*
20 * 42: the answer to everything.
21 *
22 * In this case, it happens to be the answer to
23 * 40 (length of sha1 hex representation)
24 * +1 (space in between hex and name)
25 * +1 (newline at the end of the line)
26 */
27 int len = strlen(line) - 42;
28
29 if (len <= 0)
30 return NULL;
31 if (get_sha1_hex(line, sha1) < 0)
32 return NULL;
33 if (!isspace(line[40]))
34 return NULL;
35 line += 41;
36 if (isspace(*line))
37 return NULL;
38 if (line[len] != '\n')
39 return NULL;
40 line[len] = 0;
41
42 return line;
43 }
44
45 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
46 int flag, struct ref_list *list,
47 struct ref_list **new_entry)
48 {
49 int len;
50 struct ref_list *entry;
51
52 /* Allocate it and add it in.. */
53 len = strlen(name) + 1;
54 entry = xmalloc(sizeof(struct ref_list) + len);
55 hashcpy(entry->sha1, sha1);
56 hashclr(entry->peeled);
57 memcpy(entry->name, name, len);
58 entry->flag = flag;
59 entry->next = list;
60 if (new_entry)
61 *new_entry = entry;
62 return entry;
63 }
64
65 /* merge sort the ref list */
66 static struct ref_list *sort_ref_list(struct ref_list *list)
67 {
68 int psize, qsize, last_merge_count, cmp;
69 struct ref_list *p, *q, *l, *e;
70 struct ref_list *new_list = list;
71 int k = 1;
72 int merge_count = 0;
73
74 if (!list)
75 return list;
76
77 do {
78 last_merge_count = merge_count;
79 merge_count = 0;
80
81 psize = 0;
82
83 p = new_list;
84 q = new_list;
85 new_list = NULL;
86 l = NULL;
87
88 while (p) {
89 merge_count++;
90
91 while (psize < k && q->next) {
92 q = q->next;
93 psize++;
94 }
95 qsize = k;
96
97 while ((psize > 0) || (qsize > 0 && q)) {
98 if (qsize == 0 || !q) {
99 e = p;
100 p = p->next;
101 psize--;
102 } else if (psize == 0) {
103 e = q;
104 q = q->next;
105 qsize--;
106 } else {
107 cmp = strcmp(q->name, p->name);
108 if (cmp < 0) {
109 e = q;
110 q = q->next;
111 qsize--;
112 } else if (cmp > 0) {
113 e = p;
114 p = p->next;
115 psize--;
116 } else {
117 if (hashcmp(q->sha1, p->sha1))
118 die("Duplicated ref, and SHA1s don't match: %s",
119 q->name);
120 warning("Duplicated ref: %s", q->name);
121 e = q;
122 q = q->next;
123 qsize--;
124 free(e);
125 e = p;
126 p = p->next;
127 psize--;
128 }
129 }
130
131 e->next = NULL;
132
133 if (l)
134 l->next = e;
135 if (!new_list)
136 new_list = e;
137 l = e;
138 }
139
140 p = q;
141 };
142
143 k = k * 2;
144 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
145
146 return new_list;
147 }
148
149 /*
150 * Future: need to be in "struct repository"
151 * when doing a full libification.
152 */
153 struct cached_refs {
154 char did_loose;
155 char did_packed;
156 struct ref_list *loose;
157 struct ref_list *packed;
158 } cached_refs;
159
160 static void free_ref_list(struct ref_list *list)
161 {
162 struct ref_list *next;
163 for ( ; list; list = next) {
164 next = list->next;
165 free(list);
166 }
167 }
168
169 static void invalidate_cached_refs(void)
170 {
171 struct cached_refs *ca = &cached_refs;
172
173 if (ca->did_loose && ca->loose)
174 free_ref_list(ca->loose);
175 if (ca->did_packed && ca->packed)
176 free_ref_list(ca->packed);
177 ca->loose = ca->packed = NULL;
178 ca->did_loose = ca->did_packed = 0;
179 }
180
181 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
182 {
183 struct ref_list *list = NULL;
184 struct ref_list *last = NULL;
185 char refline[PATH_MAX];
186 int flag = REF_ISPACKED;
187
188 while (fgets(refline, sizeof(refline), f)) {
189 unsigned char sha1[20];
190 const char *name;
191 static const char header[] = "# pack-refs with:";
192
193 if (!strncmp(refline, header, sizeof(header)-1)) {
194 const char *traits = refline + sizeof(header) - 1;
195 if (strstr(traits, " peeled "))
196 flag |= REF_KNOWS_PEELED;
197 /* perhaps other traits later as well */
198 continue;
199 }
200
201 name = parse_ref_line(refline, sha1);
202 if (name) {
203 list = add_ref(name, sha1, flag, list, &last);
204 continue;
205 }
206 if (last &&
207 refline[0] == '^' &&
208 strlen(refline) == 42 &&
209 refline[41] == '\n' &&
210 !get_sha1_hex(refline + 1, sha1))
211 hashcpy(last->peeled, sha1);
212 }
213 cached_refs->packed = sort_ref_list(list);
214 }
215
216 static struct ref_list *get_packed_refs(void)
217 {
218 if (!cached_refs.did_packed) {
219 FILE *f = fopen(git_path("packed-refs"), "r");
220 cached_refs.packed = NULL;
221 if (f) {
222 read_packed_refs(f, &cached_refs);
223 fclose(f);
224 }
225 cached_refs.did_packed = 1;
226 }
227 return cached_refs.packed;
228 }
229
230 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
231 {
232 DIR *dir = opendir(git_path("%s", base));
233
234 if (dir) {
235 struct dirent *de;
236 int baselen = strlen(base);
237 char *ref = xmalloc(baselen + 257);
238
239 memcpy(ref, base, baselen);
240 if (baselen && base[baselen-1] != '/')
241 ref[baselen++] = '/';
242
243 while ((de = readdir(dir)) != NULL) {
244 unsigned char sha1[20];
245 struct stat st;
246 int flag;
247 int namelen;
248
249 if (de->d_name[0] == '.')
250 continue;
251 namelen = strlen(de->d_name);
252 if (namelen > 255)
253 continue;
254 if (has_extension(de->d_name, ".lock"))
255 continue;
256 memcpy(ref + baselen, de->d_name, namelen+1);
257 if (stat(git_path("%s", ref), &st) < 0)
258 continue;
259 if (S_ISDIR(st.st_mode)) {
260 list = get_ref_dir(ref, list);
261 continue;
262 }
263 if (!resolve_ref(ref, sha1, 1, &flag)) {
264 error("%s points nowhere!", ref);
265 continue;
266 }
267 list = add_ref(ref, sha1, flag, list, NULL);
268 }
269 free(ref);
270 closedir(dir);
271 }
272 return sort_ref_list(list);
273 }
274
275 static struct ref_list *get_loose_refs(void)
276 {
277 if (!cached_refs.did_loose) {
278 cached_refs.loose = get_ref_dir("refs", NULL);
279 cached_refs.did_loose = 1;
280 }
281 return cached_refs.loose;
282 }
283
284 /* We allow "recursive" symbolic refs. Only within reason, though */
285 #define MAXDEPTH 5
286
287 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
288 {
289 int depth = MAXDEPTH, len;
290 char buffer[256];
291 static char ref_buffer[256];
292
293 if (flag)
294 *flag = 0;
295
296 for (;;) {
297 const char *path = git_path("%s", ref);
298 struct stat st;
299 char *buf;
300 int fd;
301
302 if (--depth < 0)
303 return NULL;
304
305 /* Special case: non-existing file.
306 * Not having the refs/heads/new-branch is OK
307 * if we are writing into it, so is .git/HEAD
308 * that points at refs/heads/master still to be
309 * born. It is NOT OK if we are resolving for
310 * reading.
311 */
312 if (lstat(path, &st) < 0) {
313 struct ref_list *list = get_packed_refs();
314 while (list) {
315 if (!strcmp(ref, list->name)) {
316 hashcpy(sha1, list->sha1);
317 if (flag)
318 *flag |= REF_ISPACKED;
319 return ref;
320 }
321 list = list->next;
322 }
323 if (reading || errno != ENOENT)
324 return NULL;
325 hashclr(sha1);
326 return ref;
327 }
328
329 /* Follow "normalized" - ie "refs/.." symlinks by hand */
330 if (S_ISLNK(st.st_mode)) {
331 len = readlink(path, buffer, sizeof(buffer)-1);
332 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
333 buffer[len] = 0;
334 strcpy(ref_buffer, buffer);
335 ref = ref_buffer;
336 if (flag)
337 *flag |= REF_ISSYMREF;
338 continue;
339 }
340 }
341
342 /* Is it a directory? */
343 if (S_ISDIR(st.st_mode)) {
344 errno = EISDIR;
345 return NULL;
346 }
347
348 /*
349 * Anything else, just open it and try to use it as
350 * a ref
351 */
352 fd = open(path, O_RDONLY);
353 if (fd < 0)
354 return NULL;
355 len = read_in_full(fd, buffer, sizeof(buffer)-1);
356 close(fd);
357
358 /*
359 * Is it a symbolic ref?
360 */
361 if (len < 4 || memcmp("ref:", buffer, 4))
362 break;
363 buf = buffer + 4;
364 len -= 4;
365 while (len && isspace(*buf))
366 buf++, len--;
367 while (len && isspace(buf[len-1]))
368 len--;
369 buf[len] = 0;
370 memcpy(ref_buffer, buf, len + 1);
371 ref = ref_buffer;
372 if (flag)
373 *flag |= REF_ISSYMREF;
374 }
375 if (len < 40 || get_sha1_hex(buffer, sha1))
376 return NULL;
377 return ref;
378 }
379
380 int read_ref(const char *ref, unsigned char *sha1)
381 {
382 if (resolve_ref(ref, sha1, 1, NULL))
383 return 0;
384 return -1;
385 }
386
387 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
388 void *cb_data, struct ref_list *entry)
389 {
390 if (strncmp(base, entry->name, trim))
391 return 0;
392 if (is_null_sha1(entry->sha1))
393 return 0;
394 if (!has_sha1_file(entry->sha1)) {
395 error("%s does not point to a valid object!", entry->name);
396 return 0;
397 }
398 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
399 }
400
401 int peel_ref(const char *ref, unsigned char *sha1)
402 {
403 int flag;
404 unsigned char base[20];
405 struct object *o;
406
407 if (!resolve_ref(ref, base, 1, &flag))
408 return -1;
409
410 if ((flag & REF_ISPACKED)) {
411 struct ref_list *list = get_packed_refs();
412
413 while (list) {
414 if (!strcmp(list->name, ref)) {
415 if (list->flag & REF_KNOWS_PEELED) {
416 hashcpy(sha1, list->peeled);
417 return 0;
418 }
419 /* older pack-refs did not leave peeled ones */
420 break;
421 }
422 list = list->next;
423 }
424 }
425
426 /* fallback - callers should not call this for unpacked refs */
427 o = parse_object(base);
428 if (o->type == OBJ_TAG) {
429 o = deref_tag(o, ref, 0);
430 if (o) {
431 hashcpy(sha1, o->sha1);
432 return 0;
433 }
434 }
435 return -1;
436 }
437
438 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
439 void *cb_data)
440 {
441 int retval;
442 struct ref_list *packed = get_packed_refs();
443 struct ref_list *loose = get_loose_refs();
444
445 while (packed && loose) {
446 struct ref_list *entry;
447 int cmp = strcmp(packed->name, loose->name);
448 if (!cmp) {
449 packed = packed->next;
450 continue;
451 }
452 if (cmp > 0) {
453 entry = loose;
454 loose = loose->next;
455 } else {
456 entry = packed;
457 packed = packed->next;
458 }
459 retval = do_one_ref(base, fn, trim, cb_data, entry);
460 if (retval)
461 return retval;
462 }
463
464 for (packed = packed ? packed : loose; packed; packed = packed->next) {
465 retval = do_one_ref(base, fn, trim, cb_data, packed);
466 if (retval)
467 return retval;
468 }
469 return 0;
470 }
471
472 int head_ref(each_ref_fn fn, void *cb_data)
473 {
474 unsigned char sha1[20];
475 int flag;
476
477 if (resolve_ref("HEAD", sha1, 1, &flag))
478 return fn("HEAD", sha1, flag, cb_data);
479 return 0;
480 }
481
482 int for_each_ref(each_ref_fn fn, void *cb_data)
483 {
484 return do_for_each_ref("refs/", fn, 0, cb_data);
485 }
486
487 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
488 {
489 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
490 }
491
492 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
493 {
494 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
495 }
496
497 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
498 {
499 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
500 }
501
502 /* NEEDSWORK: This is only used by ssh-upload and it should go; the
503 * caller should do resolve_ref or read_ref like everybody else. Or
504 * maybe everybody else should use get_ref_sha1() instead of doing
505 * read_ref().
506 */
507 int get_ref_sha1(const char *ref, unsigned char *sha1)
508 {
509 if (check_ref_format(ref))
510 return -1;
511 return read_ref(mkpath("refs/%s", ref), sha1);
512 }
513
514 /*
515 * Make sure "ref" is something reasonable to have under ".git/refs/";
516 * We do not like it if:
517 *
518 * - any path component of it begins with ".", or
519 * - it has double dots "..", or
520 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
521 * - it ends with a "/".
522 */
523
524 static inline int bad_ref_char(int ch)
525 {
526 return (((unsigned) ch) <= ' ' ||
527 ch == '~' || ch == '^' || ch == ':' ||
528 /* 2.13 Pattern Matching Notation */
529 ch == '?' || ch == '*' || ch == '[');
530 }
531
532 int check_ref_format(const char *ref)
533 {
534 int ch, level;
535 const char *cp = ref;
536
537 level = 0;
538 while (1) {
539 while ((ch = *cp++) == '/')
540 ; /* tolerate duplicated slashes */
541 if (!ch)
542 return -1; /* should not end with slashes */
543
544 /* we are at the beginning of the path component */
545 if (ch == '.' || bad_ref_char(ch))
546 return -1;
547
548 /* scan the rest of the path component */
549 while ((ch = *cp++) != 0) {
550 if (bad_ref_char(ch))
551 return -1;
552 if (ch == '/')
553 break;
554 if (ch == '.' && *cp == '.')
555 return -1;
556 }
557 level++;
558 if (!ch) {
559 if (level < 2)
560 return -2; /* at least of form "heads/blah" */
561 return 0;
562 }
563 }
564 }
565
566 static struct ref_lock *verify_lock(struct ref_lock *lock,
567 const unsigned char *old_sha1, int mustexist)
568 {
569 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
570 error("Can't verify ref %s", lock->ref_name);
571 unlock_ref(lock);
572 return NULL;
573 }
574 if (hashcmp(lock->old_sha1, old_sha1)) {
575 error("Ref %s is at %s but expected %s", lock->ref_name,
576 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
577 unlock_ref(lock);
578 return NULL;
579 }
580 return lock;
581 }
582
583 static int remove_empty_dir_recursive(char *path, int len)
584 {
585 DIR *dir = opendir(path);
586 struct dirent *e;
587 int ret = 0;
588
589 if (!dir)
590 return -1;
591 if (path[len-1] != '/')
592 path[len++] = '/';
593 while ((e = readdir(dir)) != NULL) {
594 struct stat st;
595 int namlen;
596 if ((e->d_name[0] == '.') &&
597 ((e->d_name[1] == 0) ||
598 ((e->d_name[1] == '.') && e->d_name[2] == 0)))
599 continue; /* "." and ".." */
600
601 namlen = strlen(e->d_name);
602 if ((len + namlen < PATH_MAX) &&
603 strcpy(path + len, e->d_name) &&
604 !lstat(path, &st) &&
605 S_ISDIR(st.st_mode) &&
606 !remove_empty_dir_recursive(path, len + namlen))
607 continue; /* happy */
608
609 /* path too long, stat fails, or non-directory still exists */
610 ret = -1;
611 break;
612 }
613 closedir(dir);
614 if (!ret) {
615 path[len] = 0;
616 ret = rmdir(path);
617 }
618 return ret;
619 }
620
621 static int remove_empty_directories(char *file)
622 {
623 /* we want to create a file but there is a directory there;
624 * if that is an empty directory (or a directory that contains
625 * only empty directories), remove them.
626 */
627 char path[PATH_MAX];
628 int len = strlen(file);
629
630 if (len >= PATH_MAX) /* path too long ;-) */
631 return -1;
632 strcpy(path, file);
633 return remove_empty_dir_recursive(path, len);
634 }
635
636 static int is_refname_available(const char *ref, const char *oldref,
637 struct ref_list *list, int quiet)
638 {
639 int namlen = strlen(ref); /* e.g. 'foo/bar' */
640 while (list) {
641 /* list->name could be 'foo' or 'foo/bar/baz' */
642 if (!oldref || strcmp(oldref, list->name)) {
643 int len = strlen(list->name);
644 int cmplen = (namlen < len) ? namlen : len;
645 const char *lead = (namlen < len) ? list->name : ref;
646 if (!strncmp(ref, list->name, cmplen) &&
647 lead[cmplen] == '/') {
648 if (!quiet)
649 error("'%s' exists; cannot create '%s'",
650 list->name, ref);
651 return 0;
652 }
653 }
654 list = list->next;
655 }
656 return 1;
657 }
658
659 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int *flag)
660 {
661 char *ref_file;
662 const char *orig_ref = ref;
663 struct ref_lock *lock;
664 struct stat st;
665 int last_errno = 0;
666 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
667
668 lock = xcalloc(1, sizeof(struct ref_lock));
669 lock->lock_fd = -1;
670
671 ref = resolve_ref(ref, lock->old_sha1, mustexist, flag);
672 if (!ref && errno == EISDIR) {
673 /* we are trying to lock foo but we used to
674 * have foo/bar which now does not exist;
675 * it is normal for the empty directory 'foo'
676 * to remain.
677 */
678 ref_file = git_path("%s", orig_ref);
679 if (remove_empty_directories(ref_file)) {
680 last_errno = errno;
681 error("there are still refs under '%s'", orig_ref);
682 goto error_return;
683 }
684 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, flag);
685 }
686 if (!ref) {
687 last_errno = errno;
688 error("unable to resolve reference %s: %s",
689 orig_ref, strerror(errno));
690 goto error_return;
691 }
692 /* When the ref did not exist and we are creating it,
693 * make sure there is no existing ref that is packed
694 * whose name begins with our refname, nor a ref whose
695 * name is a proper prefix of our refname.
696 */
697 if (is_null_sha1(lock->old_sha1) &&
698 !is_refname_available(ref, NULL, get_packed_refs(), 0))
699 goto error_return;
700
701 lock->lk = xcalloc(1, sizeof(struct lock_file));
702
703 lock->ref_name = xstrdup(ref);
704 lock->orig_ref_name = xstrdup(orig_ref);
705 ref_file = git_path("%s", ref);
706 lock->force_write = lstat(ref_file, &st) && errno == ENOENT;
707
708 if (safe_create_leading_directories(ref_file)) {
709 last_errno = errno;
710 error("unable to create directory for %s", ref_file);
711 goto error_return;
712 }
713 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
714
715 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
716
717 error_return:
718 unlock_ref(lock);
719 errno = last_errno;
720 return NULL;
721 }
722
723 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
724 {
725 char refpath[PATH_MAX];
726 if (check_ref_format(ref))
727 return NULL;
728 strcpy(refpath, mkpath("refs/%s", ref));
729 return lock_ref_sha1_basic(refpath, old_sha1, NULL);
730 }
731
732 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1)
733 {
734 if (check_ref_format(ref) == -1)
735 return NULL;
736 return lock_ref_sha1_basic(ref, old_sha1, NULL);
737 }
738
739 static struct lock_file packlock;
740
741 static int repack_without_ref(const char *refname)
742 {
743 struct ref_list *list, *packed_ref_list;
744 int fd;
745 int found = 0;
746
747 packed_ref_list = get_packed_refs();
748 for (list = packed_ref_list; list; list = list->next) {
749 if (!strcmp(refname, list->name)) {
750 found = 1;
751 break;
752 }
753 }
754 if (!found)
755 return 0;
756 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
757 if (fd < 0)
758 return error("cannot delete '%s' from packed refs", refname);
759
760 for (list = packed_ref_list; list; list = list->next) {
761 char line[PATH_MAX + 100];
762 int len;
763
764 if (!strcmp(refname, list->name))
765 continue;
766 len = snprintf(line, sizeof(line), "%s %s\n",
767 sha1_to_hex(list->sha1), list->name);
768 /* this should not happen but just being defensive */
769 if (len > sizeof(line))
770 die("too long a refname '%s'", list->name);
771 write_or_die(fd, line, len);
772 }
773 return commit_lock_file(&packlock);
774 }
775
776 int delete_ref(const char *refname, const unsigned char *sha1)
777 {
778 struct ref_lock *lock;
779 int err, i, ret = 0, flag = 0;
780
781 lock = lock_ref_sha1_basic(refname, sha1, &flag);
782 if (!lock)
783 return 1;
784 if (!(flag & REF_ISPACKED)) {
785 /* loose */
786 i = strlen(lock->lk->filename) - 5; /* .lock */
787 lock->lk->filename[i] = 0;
788 err = unlink(lock->lk->filename);
789 if (err) {
790 ret = 1;
791 error("unlink(%s) failed: %s",
792 lock->lk->filename, strerror(errno));
793 }
794 lock->lk->filename[i] = '.';
795 }
796 /* removing the loose one could have resurrected an earlier
797 * packed one. Also, if it was not loose we need to repack
798 * without it.
799 */
800 ret |= repack_without_ref(refname);
801
802 err = unlink(git_path("logs/%s", lock->ref_name));
803 if (err && errno != ENOENT)
804 fprintf(stderr, "warning: unlink(%s) failed: %s",
805 git_path("logs/%s", lock->ref_name), strerror(errno));
806 invalidate_cached_refs();
807 unlock_ref(lock);
808 return ret;
809 }
810
811 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
812 {
813 static const char renamed_ref[] = "RENAMED-REF";
814 unsigned char sha1[20], orig_sha1[20];
815 int flag = 0, logmoved = 0;
816 struct ref_lock *lock;
817 struct stat loginfo;
818 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
819
820 if (S_ISLNK(loginfo.st_mode))
821 return error("reflog for %s is a symlink", oldref);
822
823 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
824 return error("refname %s not found", oldref);
825
826 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
827 return 1;
828
829 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
830 return 1;
831
832 lock = lock_ref_sha1_basic(renamed_ref, NULL, NULL);
833 if (!lock)
834 return error("unable to lock %s", renamed_ref);
835 lock->force_write = 1;
836 if (write_ref_sha1(lock, orig_sha1, logmsg))
837 return error("unable to save current sha1 in %s", renamed_ref);
838
839 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
840 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
841 oldref, strerror(errno));
842
843 if (delete_ref(oldref, orig_sha1)) {
844 error("unable to delete old %s", oldref);
845 goto rollback;
846 }
847
848 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
849 if (errno==EISDIR) {
850 if (remove_empty_directories(git_path("%s", newref))) {
851 error("Directory not empty: %s", newref);
852 goto rollback;
853 }
854 } else {
855 error("unable to delete existing %s", newref);
856 goto rollback;
857 }
858 }
859
860 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
861 error("unable to create directory for %s", newref);
862 goto rollback;
863 }
864
865 retry:
866 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
867 if (errno==EISDIR || errno==ENOTDIR) {
868 /*
869 * rename(a, b) when b is an existing
870 * directory ought to result in ISDIR, but
871 * Solaris 5.8 gives ENOTDIR. Sheesh.
872 */
873 if (remove_empty_directories(git_path("logs/%s", newref))) {
874 error("Directory not empty: logs/%s", newref);
875 goto rollback;
876 }
877 goto retry;
878 } else {
879 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
880 newref, strerror(errno));
881 goto rollback;
882 }
883 }
884 logmoved = log;
885
886 lock = lock_ref_sha1_basic(newref, NULL, NULL);
887 if (!lock) {
888 error("unable to lock %s for update", newref);
889 goto rollback;
890 }
891
892 lock->force_write = 1;
893 hashcpy(lock->old_sha1, orig_sha1);
894 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
895 error("unable to write current sha1 into %s", newref);
896 goto rollback;
897 }
898
899 return 0;
900
901 rollback:
902 lock = lock_ref_sha1_basic(oldref, NULL, NULL);
903 if (!lock) {
904 error("unable to lock %s for rollback", oldref);
905 goto rollbacklog;
906 }
907
908 lock->force_write = 1;
909 flag = log_all_ref_updates;
910 log_all_ref_updates = 0;
911 if (write_ref_sha1(lock, orig_sha1, NULL))
912 error("unable to write current sha1 into %s", oldref);
913 log_all_ref_updates = flag;
914
915 rollbacklog:
916 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
917 error("unable to restore logfile %s from %s: %s",
918 oldref, newref, strerror(errno));
919 if (!logmoved && log &&
920 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
921 error("unable to restore logfile %s from tmp-renamed-log: %s",
922 oldref, strerror(errno));
923
924 return 1;
925 }
926
927 void unlock_ref(struct ref_lock *lock)
928 {
929 if (lock->lock_fd >= 0) {
930 close(lock->lock_fd);
931 /* Do not free lock->lk -- atexit() still looks at them */
932 if (lock->lk)
933 rollback_lock_file(lock->lk);
934 }
935 free(lock->ref_name);
936 free(lock->orig_ref_name);
937 free(lock);
938 }
939
940 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
941 const unsigned char *new_sha1, const char *msg)
942 {
943 int logfd, written, oflags = O_APPEND | O_WRONLY;
944 unsigned maxlen, len;
945 int msglen;
946 char *log_file, *logrec;
947 const char *committer;
948
949 if (log_all_ref_updates < 0)
950 log_all_ref_updates = !is_bare_repository();
951
952 log_file = git_path("logs/%s", ref_name);
953
954 if (log_all_ref_updates &&
955 (!prefixcmp(ref_name, "refs/heads/") ||
956 !prefixcmp(ref_name, "refs/remotes/") ||
957 !strcmp(ref_name, "HEAD"))) {
958 if (safe_create_leading_directories(log_file) < 0)
959 return error("unable to create directory for %s",
960 log_file);
961 oflags |= O_CREAT;
962 }
963
964 logfd = open(log_file, oflags, 0666);
965 if (logfd < 0) {
966 if (!(oflags & O_CREAT) && errno == ENOENT)
967 return 0;
968
969 if ((oflags & O_CREAT) && errno == EISDIR) {
970 if (remove_empty_directories(log_file)) {
971 return error("There are still logs under '%s'",
972 log_file);
973 }
974 logfd = open(log_file, oflags, 0666);
975 }
976
977 if (logfd < 0)
978 return error("Unable to append to %s: %s",
979 log_file, strerror(errno));
980 }
981
982 adjust_shared_perm(log_file);
983
984 msglen = 0;
985 if (msg) {
986 /* clean up the message and make sure it is a single line */
987 for ( ; *msg; msg++)
988 if (!isspace(*msg))
989 break;
990 if (*msg) {
991 const char *ep = strchr(msg, '\n');
992 if (ep)
993 msglen = ep - msg;
994 else
995 msglen = strlen(msg);
996 }
997 }
998
999 committer = git_committer_info(-1);
1000 maxlen = strlen(committer) + msglen + 100;
1001 logrec = xmalloc(maxlen);
1002 len = sprintf(logrec, "%s %s %s\n",
1003 sha1_to_hex(old_sha1),
1004 sha1_to_hex(new_sha1),
1005 committer);
1006 if (msglen)
1007 len += sprintf(logrec + len - 1, "\t%.*s\n", msglen, msg) - 1;
1008 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1009 free(logrec);
1010 close(logfd);
1011 if (written != len)
1012 return error("Unable to append to %s", log_file);
1013 return 0;
1014 }
1015
1016 int write_ref_sha1(struct ref_lock *lock,
1017 const unsigned char *sha1, const char *logmsg)
1018 {
1019 static char term = '\n';
1020
1021 if (!lock)
1022 return -1;
1023 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1024 unlock_ref(lock);
1025 return 0;
1026 }
1027 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1028 write_in_full(lock->lock_fd, &term, 1) != 1
1029 || close(lock->lock_fd) < 0) {
1030 error("Couldn't write %s", lock->lk->filename);
1031 unlock_ref(lock);
1032 return -1;
1033 }
1034 invalidate_cached_refs();
1035 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1036 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1037 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1038 unlock_ref(lock);
1039 return -1;
1040 }
1041 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1042 /*
1043 * Special hack: If a branch is updated directly and HEAD
1044 * points to it (may happen on the remote side of a push
1045 * for example) then logically the HEAD reflog should be
1046 * updated too.
1047 * A generic solution implies reverse symref information,
1048 * but finding all symrefs pointing to the given branch
1049 * would be rather costly for this rare event (the direct
1050 * update of a branch) to be worth it. So let's cheat and
1051 * check with HEAD only which should cover 99% of all usage
1052 * scenarios (even 100% of the default ones).
1053 */
1054 unsigned char head_sha1[20];
1055 int head_flag;
1056 const char *head_ref;
1057 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1058 if (head_ref && (head_flag & REF_ISSYMREF) &&
1059 !strcmp(head_ref, lock->ref_name))
1060 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1061 }
1062 if (commit_lock_file(lock->lk)) {
1063 error("Couldn't set %s", lock->ref_name);
1064 unlock_ref(lock);
1065 return -1;
1066 }
1067 lock->lock_fd = -1;
1068 unlock_ref(lock);
1069 return 0;
1070 }
1071
1072 int create_symref(const char *ref_target, const char *refs_heads_master,
1073 const char *logmsg)
1074 {
1075 const char *lockpath;
1076 char ref[1000];
1077 int fd, len, written;
1078 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1079 unsigned char old_sha1[20], new_sha1[20];
1080
1081 if (logmsg && read_ref(ref_target, old_sha1))
1082 hashclr(old_sha1);
1083
1084 if (safe_create_leading_directories(git_HEAD) < 0)
1085 return error("unable to create directory for %s", git_HEAD);
1086
1087 #ifndef NO_SYMLINK_HEAD
1088 if (prefer_symlink_refs) {
1089 unlink(git_HEAD);
1090 if (!symlink(refs_heads_master, git_HEAD))
1091 goto done;
1092 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1093 }
1094 #endif
1095
1096 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1097 if (sizeof(ref) <= len) {
1098 error("refname too long: %s", refs_heads_master);
1099 goto error_free_return;
1100 }
1101 lockpath = mkpath("%s.lock", git_HEAD);
1102 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1103 if (fd < 0) {
1104 error("Unable to open %s for writing", lockpath);
1105 goto error_free_return;
1106 }
1107 written = write_in_full(fd, ref, len);
1108 close(fd);
1109 if (written != len) {
1110 error("Unable to write to %s", lockpath);
1111 goto error_unlink_return;
1112 }
1113 if (rename(lockpath, git_HEAD) < 0) {
1114 error("Unable to create %s", git_HEAD);
1115 goto error_unlink_return;
1116 }
1117 if (adjust_shared_perm(git_HEAD)) {
1118 error("Unable to fix permissions on %s", lockpath);
1119 error_unlink_return:
1120 unlink(lockpath);
1121 error_free_return:
1122 free(git_HEAD);
1123 return -1;
1124 }
1125
1126 #ifndef NO_SYMLINK_HEAD
1127 done:
1128 #endif
1129 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1130 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1131
1132 free(git_HEAD);
1133 return 0;
1134 }
1135
1136 static char *ref_msg(const char *line, const char *endp)
1137 {
1138 const char *ep;
1139 char *msg;
1140
1141 line += 82;
1142 for (ep = line; ep < endp && *ep != '\n'; ep++)
1143 ;
1144 msg = xmalloc(ep - line + 1);
1145 memcpy(msg, line, ep - line);
1146 msg[ep - line] = 0;
1147 return msg;
1148 }
1149
1150 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)
1151 {
1152 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1153 char *tz_c;
1154 int logfd, tz, reccnt = 0;
1155 struct stat st;
1156 unsigned long date;
1157 unsigned char logged_sha1[20];
1158 void *log_mapped;
1159 size_t mapsz;
1160
1161 logfile = git_path("logs/%s", ref);
1162 logfd = open(logfile, O_RDONLY, 0);
1163 if (logfd < 0)
1164 die("Unable to read log %s: %s", logfile, strerror(errno));
1165 fstat(logfd, &st);
1166 if (!st.st_size)
1167 die("Log %s is empty.", logfile);
1168 mapsz = xsize_t(st.st_size);
1169 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1170 logdata = log_mapped;
1171 close(logfd);
1172
1173 lastrec = NULL;
1174 rec = logend = logdata + st.st_size;
1175 while (logdata < rec) {
1176 reccnt++;
1177 if (logdata < rec && *(rec-1) == '\n')
1178 rec--;
1179 lastgt = NULL;
1180 while (logdata < rec && *(rec-1) != '\n') {
1181 rec--;
1182 if (*rec == '>')
1183 lastgt = rec;
1184 }
1185 if (!lastgt)
1186 die("Log %s is corrupt.", logfile);
1187 date = strtoul(lastgt + 1, &tz_c, 10);
1188 if (date <= at_time || cnt == 0) {
1189 tz = strtoul(tz_c, NULL, 10);
1190 if (msg)
1191 *msg = ref_msg(rec, logend);
1192 if (cutoff_time)
1193 *cutoff_time = date;
1194 if (cutoff_tz)
1195 *cutoff_tz = tz;
1196 if (cutoff_cnt)
1197 *cutoff_cnt = reccnt - 1;
1198 if (lastrec) {
1199 if (get_sha1_hex(lastrec, logged_sha1))
1200 die("Log %s is corrupt.", logfile);
1201 if (get_sha1_hex(rec + 41, sha1))
1202 die("Log %s is corrupt.", logfile);
1203 if (hashcmp(logged_sha1, sha1)) {
1204 fprintf(stderr,
1205 "warning: Log %s has gap after %s.\n",
1206 logfile, show_rfc2822_date(date, tz));
1207 }
1208 }
1209 else if (date == at_time) {
1210 if (get_sha1_hex(rec + 41, sha1))
1211 die("Log %s is corrupt.", logfile);
1212 }
1213 else {
1214 if (get_sha1_hex(rec + 41, logged_sha1))
1215 die("Log %s is corrupt.", logfile);
1216 if (hashcmp(logged_sha1, sha1)) {
1217 fprintf(stderr,
1218 "warning: Log %s unexpectedly ended on %s.\n",
1219 logfile, show_rfc2822_date(date, tz));
1220 }
1221 }
1222 munmap(log_mapped, mapsz);
1223 return 0;
1224 }
1225 lastrec = rec;
1226 if (cnt > 0)
1227 cnt--;
1228 }
1229
1230 rec = logdata;
1231 while (rec < logend && *rec != '>' && *rec != '\n')
1232 rec++;
1233 if (rec == logend || *rec == '\n')
1234 die("Log %s is corrupt.", logfile);
1235 date = strtoul(rec + 1, &tz_c, 10);
1236 tz = strtoul(tz_c, NULL, 10);
1237 if (get_sha1_hex(logdata, sha1))
1238 die("Log %s is corrupt.", logfile);
1239 if (msg)
1240 *msg = ref_msg(logdata, logend);
1241 munmap(log_mapped, mapsz);
1242
1243 if (cutoff_time)
1244 *cutoff_time = date;
1245 if (cutoff_tz)
1246 *cutoff_tz = tz;
1247 if (cutoff_cnt)
1248 *cutoff_cnt = reccnt;
1249 return 1;
1250 }
1251
1252 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1253 {
1254 const char *logfile;
1255 FILE *logfp;
1256 char buf[1024];
1257 int ret = 0;
1258
1259 logfile = git_path("logs/%s", ref);
1260 logfp = fopen(logfile, "r");
1261 if (!logfp)
1262 return -1;
1263 while (fgets(buf, sizeof(buf), logfp)) {
1264 unsigned char osha1[20], nsha1[20];
1265 char *email_end, *message;
1266 unsigned long timestamp;
1267 int len, tz;
1268
1269 /* old SP new SP name <email> SP time TAB msg LF */
1270 len = strlen(buf);
1271 if (len < 83 || buf[len-1] != '\n' ||
1272 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1273 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1274 !(email_end = strchr(buf + 82, '>')) ||
1275 email_end[1] != ' ' ||
1276 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1277 !message || message[0] != ' ' ||
1278 (message[1] != '+' && message[1] != '-') ||
1279 !isdigit(message[2]) || !isdigit(message[3]) ||
1280 !isdigit(message[4]) || !isdigit(message[5]))
1281 continue; /* corrupt? */
1282 email_end[1] = '\0';
1283 tz = strtol(message + 1, NULL, 10);
1284 if (message[6] != '\t')
1285 message += 6;
1286 else
1287 message += 7;
1288 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1289 if (ret)
1290 break;
1291 }
1292 fclose(logfp);
1293 return ret;
1294 }
1295
1296 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1297 {
1298 DIR *dir = opendir(git_path("logs/%s", base));
1299 int retval = 0;
1300
1301 if (dir) {
1302 struct dirent *de;
1303 int baselen = strlen(base);
1304 char *log = xmalloc(baselen + 257);
1305
1306 memcpy(log, base, baselen);
1307 if (baselen && base[baselen-1] != '/')
1308 log[baselen++] = '/';
1309
1310 while ((de = readdir(dir)) != NULL) {
1311 struct stat st;
1312 int namelen;
1313
1314 if (de->d_name[0] == '.')
1315 continue;
1316 namelen = strlen(de->d_name);
1317 if (namelen > 255)
1318 continue;
1319 if (has_extension(de->d_name, ".lock"))
1320 continue;
1321 memcpy(log + baselen, de->d_name, namelen+1);
1322 if (stat(git_path("logs/%s", log), &st) < 0)
1323 continue;
1324 if (S_ISDIR(st.st_mode)) {
1325 retval = do_for_each_reflog(log, fn, cb_data);
1326 } else {
1327 unsigned char sha1[20];
1328 if (!resolve_ref(log, sha1, 0, NULL))
1329 retval = error("bad ref for %s", log);
1330 else
1331 retval = fn(log, sha1, 0, cb_data);
1332 }
1333 if (retval)
1334 break;
1335 }
1336 free(log);
1337 closedir(dir);
1338 }
1339 else if (*base)
1340 return errno;
1341 return retval;
1342 }
1343
1344 int for_each_reflog(each_ref_fn fn, void *cb_data)
1345 {
1346 return do_for_each_reflog("", fn, cb_data);
1347 }