More static
[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 static 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 #define MAXREFLEN (1024)
287
288 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
289 {
290 FILE *f;
291 struct cached_refs refs;
292 struct ref_list *ref;
293 int retval;
294
295 strcpy(name + pathlen, "packed-refs");
296 f = fopen(name, "r");
297 if (!f)
298 return -1;
299 read_packed_refs(f, &refs);
300 fclose(f);
301 ref = refs.packed;
302 retval = -1;
303 while (ref) {
304 if (!strcmp(ref->name, refname)) {
305 retval = 0;
306 memcpy(result, ref->sha1, 20);
307 break;
308 }
309 ref = ref->next;
310 }
311 free_ref_list(refs.packed);
312 return retval;
313 }
314
315 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
316 {
317 int fd, len = strlen(refname);
318 char buffer[128], *p;
319
320 if (recursion > MAXDEPTH || len > MAXREFLEN)
321 return -1;
322 memcpy(name + pathlen, refname, len+1);
323 fd = open(name, O_RDONLY);
324 if (fd < 0)
325 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
326
327 len = read(fd, buffer, sizeof(buffer)-1);
328 close(fd);
329 if (len < 0)
330 return -1;
331 while (len && isspace(buffer[len-1]))
332 len--;
333 buffer[len] = 0;
334
335 /* Was it a detached head or an old-fashioned symlink? */
336 if (!get_sha1_hex(buffer, result))
337 return 0;
338
339 /* Symref? */
340 if (strncmp(buffer, "ref:", 4))
341 return -1;
342 p = buffer + 4;
343 while (isspace(*p))
344 p++;
345
346 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
347 }
348
349 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
350 {
351 int len = strlen(path), retval;
352 char *gitdir;
353
354 while (len && path[len-1] == '/')
355 len--;
356 if (!len)
357 return -1;
358 gitdir = xmalloc(len + MAXREFLEN + 8);
359 memcpy(gitdir, path, len);
360 memcpy(gitdir + len, "/.git/", 7);
361
362 retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
363 free(gitdir);
364 return retval;
365 }
366
367 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
368 {
369 int depth = MAXDEPTH, len;
370 char buffer[256];
371 static char ref_buffer[256];
372
373 if (flag)
374 *flag = 0;
375
376 for (;;) {
377 const char *path = git_path("%s", ref);
378 struct stat st;
379 char *buf;
380 int fd;
381
382 if (--depth < 0)
383 return NULL;
384
385 /* Special case: non-existing file.
386 * Not having the refs/heads/new-branch is OK
387 * if we are writing into it, so is .git/HEAD
388 * that points at refs/heads/master still to be
389 * born. It is NOT OK if we are resolving for
390 * reading.
391 */
392 if (lstat(path, &st) < 0) {
393 struct ref_list *list = get_packed_refs();
394 while (list) {
395 if (!strcmp(ref, list->name)) {
396 hashcpy(sha1, list->sha1);
397 if (flag)
398 *flag |= REF_ISPACKED;
399 return ref;
400 }
401 list = list->next;
402 }
403 if (reading || errno != ENOENT)
404 return NULL;
405 hashclr(sha1);
406 return ref;
407 }
408
409 /* Follow "normalized" - ie "refs/.." symlinks by hand */
410 if (S_ISLNK(st.st_mode)) {
411 len = readlink(path, buffer, sizeof(buffer)-1);
412 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
413 buffer[len] = 0;
414 strcpy(ref_buffer, buffer);
415 ref = ref_buffer;
416 if (flag)
417 *flag |= REF_ISSYMREF;
418 continue;
419 }
420 }
421
422 /* Is it a directory? */
423 if (S_ISDIR(st.st_mode)) {
424 errno = EISDIR;
425 return NULL;
426 }
427
428 /*
429 * Anything else, just open it and try to use it as
430 * a ref
431 */
432 fd = open(path, O_RDONLY);
433 if (fd < 0)
434 return NULL;
435 len = read_in_full(fd, buffer, sizeof(buffer)-1);
436 close(fd);
437
438 /*
439 * Is it a symbolic ref?
440 */
441 if (len < 4 || memcmp("ref:", buffer, 4))
442 break;
443 buf = buffer + 4;
444 len -= 4;
445 while (len && isspace(*buf))
446 buf++, len--;
447 while (len && isspace(buf[len-1]))
448 len--;
449 buf[len] = 0;
450 memcpy(ref_buffer, buf, len + 1);
451 ref = ref_buffer;
452 if (flag)
453 *flag |= REF_ISSYMREF;
454 }
455 if (len < 40 || get_sha1_hex(buffer, sha1))
456 return NULL;
457 return ref;
458 }
459
460 int read_ref(const char *ref, unsigned char *sha1)
461 {
462 if (resolve_ref(ref, sha1, 1, NULL))
463 return 0;
464 return -1;
465 }
466
467 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
468 void *cb_data, struct ref_list *entry)
469 {
470 if (strncmp(base, entry->name, trim))
471 return 0;
472 if (is_null_sha1(entry->sha1))
473 return 0;
474 if (!has_sha1_file(entry->sha1)) {
475 error("%s does not point to a valid object!", entry->name);
476 return 0;
477 }
478 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
479 }
480
481 int peel_ref(const char *ref, unsigned char *sha1)
482 {
483 int flag;
484 unsigned char base[20];
485 struct object *o;
486
487 if (!resolve_ref(ref, base, 1, &flag))
488 return -1;
489
490 if ((flag & REF_ISPACKED)) {
491 struct ref_list *list = get_packed_refs();
492
493 while (list) {
494 if (!strcmp(list->name, ref)) {
495 if (list->flag & REF_KNOWS_PEELED) {
496 hashcpy(sha1, list->peeled);
497 return 0;
498 }
499 /* older pack-refs did not leave peeled ones */
500 break;
501 }
502 list = list->next;
503 }
504 }
505
506 /* fallback - callers should not call this for unpacked refs */
507 o = parse_object(base);
508 if (o->type == OBJ_TAG) {
509 o = deref_tag(o, ref, 0);
510 if (o) {
511 hashcpy(sha1, o->sha1);
512 return 0;
513 }
514 }
515 return -1;
516 }
517
518 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
519 void *cb_data)
520 {
521 int retval;
522 struct ref_list *packed = get_packed_refs();
523 struct ref_list *loose = get_loose_refs();
524
525 while (packed && loose) {
526 struct ref_list *entry;
527 int cmp = strcmp(packed->name, loose->name);
528 if (!cmp) {
529 packed = packed->next;
530 continue;
531 }
532 if (cmp > 0) {
533 entry = loose;
534 loose = loose->next;
535 } else {
536 entry = packed;
537 packed = packed->next;
538 }
539 retval = do_one_ref(base, fn, trim, cb_data, entry);
540 if (retval)
541 return retval;
542 }
543
544 for (packed = packed ? packed : loose; packed; packed = packed->next) {
545 retval = do_one_ref(base, fn, trim, cb_data, packed);
546 if (retval)
547 return retval;
548 }
549 return 0;
550 }
551
552 int head_ref(each_ref_fn fn, void *cb_data)
553 {
554 unsigned char sha1[20];
555 int flag;
556
557 if (resolve_ref("HEAD", sha1, 1, &flag))
558 return fn("HEAD", sha1, flag, cb_data);
559 return 0;
560 }
561
562 int for_each_ref(each_ref_fn fn, void *cb_data)
563 {
564 return do_for_each_ref("refs/", fn, 0, cb_data);
565 }
566
567 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
568 {
569 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
570 }
571
572 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
573 {
574 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
575 }
576
577 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
578 {
579 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
580 }
581
582 /* NEEDSWORK: This is only used by ssh-upload and it should go; the
583 * caller should do resolve_ref or read_ref like everybody else. Or
584 * maybe everybody else should use get_ref_sha1() instead of doing
585 * read_ref().
586 */
587 int get_ref_sha1(const char *ref, unsigned char *sha1)
588 {
589 if (check_ref_format(ref))
590 return -1;
591 return read_ref(mkpath("refs/%s", ref), sha1);
592 }
593
594 /*
595 * Make sure "ref" is something reasonable to have under ".git/refs/";
596 * We do not like it if:
597 *
598 * - any path component of it begins with ".", or
599 * - it has double dots "..", or
600 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
601 * - it ends with a "/".
602 */
603
604 static inline int bad_ref_char(int ch)
605 {
606 if (((unsigned) ch) <= ' ' ||
607 ch == '~' || ch == '^' || ch == ':')
608 return 1;
609 /* 2.13 Pattern Matching Notation */
610 if (ch == '?' || ch == '[') /* Unsupported */
611 return 1;
612 if (ch == '*') /* Supported at the end */
613 return 2;
614 return 0;
615 }
616
617 int check_ref_format(const char *ref)
618 {
619 int ch, level, bad_type;
620 const char *cp = ref;
621
622 level = 0;
623 while (1) {
624 while ((ch = *cp++) == '/')
625 ; /* tolerate duplicated slashes */
626 if (!ch)
627 return -1; /* should not end with slashes */
628
629 /* we are at the beginning of the path component */
630 if (ch == '.')
631 return -1;
632 bad_type = bad_ref_char(ch);
633 if (bad_type) {
634 return (bad_type == 2 && !*cp) ? -3 : -1;
635 }
636
637 /* scan the rest of the path component */
638 while ((ch = *cp++) != 0) {
639 bad_type = bad_ref_char(ch);
640 if (bad_type) {
641 return (bad_type == 2 && !*cp) ? -3 : -1;
642 }
643 if (ch == '/')
644 break;
645 if (ch == '.' && *cp == '.')
646 return -1;
647 }
648 level++;
649 if (!ch) {
650 if (level < 2)
651 return -2; /* at least of form "heads/blah" */
652 return 0;
653 }
654 }
655 }
656
657 static struct ref_lock *verify_lock(struct ref_lock *lock,
658 const unsigned char *old_sha1, int mustexist)
659 {
660 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
661 error("Can't verify ref %s", lock->ref_name);
662 unlock_ref(lock);
663 return NULL;
664 }
665 if (hashcmp(lock->old_sha1, old_sha1)) {
666 error("Ref %s is at %s but expected %s", lock->ref_name,
667 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
668 unlock_ref(lock);
669 return NULL;
670 }
671 return lock;
672 }
673
674 static int remove_empty_dir_recursive(char *path, int len)
675 {
676 DIR *dir = opendir(path);
677 struct dirent *e;
678 int ret = 0;
679
680 if (!dir)
681 return -1;
682 if (path[len-1] != '/')
683 path[len++] = '/';
684 while ((e = readdir(dir)) != NULL) {
685 struct stat st;
686 int namlen;
687 if ((e->d_name[0] == '.') &&
688 ((e->d_name[1] == 0) ||
689 ((e->d_name[1] == '.') && e->d_name[2] == 0)))
690 continue; /* "." and ".." */
691
692 namlen = strlen(e->d_name);
693 if ((len + namlen < PATH_MAX) &&
694 strcpy(path + len, e->d_name) &&
695 !lstat(path, &st) &&
696 S_ISDIR(st.st_mode) &&
697 !remove_empty_dir_recursive(path, len + namlen))
698 continue; /* happy */
699
700 /* path too long, stat fails, or non-directory still exists */
701 ret = -1;
702 break;
703 }
704 closedir(dir);
705 if (!ret) {
706 path[len] = 0;
707 ret = rmdir(path);
708 }
709 return ret;
710 }
711
712 static int remove_empty_directories(char *file)
713 {
714 /* we want to create a file but there is a directory there;
715 * if that is an empty directory (or a directory that contains
716 * only empty directories), remove them.
717 */
718 char path[PATH_MAX];
719 int len = strlen(file);
720
721 if (len >= PATH_MAX) /* path too long ;-) */
722 return -1;
723 strcpy(path, file);
724 return remove_empty_dir_recursive(path, len);
725 }
726
727 static int is_refname_available(const char *ref, const char *oldref,
728 struct ref_list *list, int quiet)
729 {
730 int namlen = strlen(ref); /* e.g. 'foo/bar' */
731 while (list) {
732 /* list->name could be 'foo' or 'foo/bar/baz' */
733 if (!oldref || strcmp(oldref, list->name)) {
734 int len = strlen(list->name);
735 int cmplen = (namlen < len) ? namlen : len;
736 const char *lead = (namlen < len) ? list->name : ref;
737 if (!strncmp(ref, list->name, cmplen) &&
738 lead[cmplen] == '/') {
739 if (!quiet)
740 error("'%s' exists; cannot create '%s'",
741 list->name, ref);
742 return 0;
743 }
744 }
745 list = list->next;
746 }
747 return 1;
748 }
749
750 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
751 {
752 char *ref_file;
753 const char *orig_ref = ref;
754 struct ref_lock *lock;
755 struct stat st;
756 int last_errno = 0;
757 int type;
758 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
759
760 lock = xcalloc(1, sizeof(struct ref_lock));
761 lock->lock_fd = -1;
762
763 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
764 if (!ref && errno == EISDIR) {
765 /* we are trying to lock foo but we used to
766 * have foo/bar which now does not exist;
767 * it is normal for the empty directory 'foo'
768 * to remain.
769 */
770 ref_file = git_path("%s", orig_ref);
771 if (remove_empty_directories(ref_file)) {
772 last_errno = errno;
773 error("there are still refs under '%s'", orig_ref);
774 goto error_return;
775 }
776 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
777 }
778 if (type_p)
779 *type_p = type;
780 if (!ref) {
781 last_errno = errno;
782 error("unable to resolve reference %s: %s",
783 orig_ref, strerror(errno));
784 goto error_return;
785 }
786 /* When the ref did not exist and we are creating it,
787 * make sure there is no existing ref that is packed
788 * whose name begins with our refname, nor a ref whose
789 * name is a proper prefix of our refname.
790 */
791 if (is_null_sha1(lock->old_sha1) &&
792 !is_refname_available(ref, NULL, get_packed_refs(), 0))
793 goto error_return;
794
795 lock->lk = xcalloc(1, sizeof(struct lock_file));
796
797 if (flags & REF_NODEREF)
798 ref = orig_ref;
799 lock->ref_name = xstrdup(ref);
800 lock->orig_ref_name = xstrdup(orig_ref);
801 ref_file = git_path("%s", ref);
802 if (lstat(ref_file, &st) && errno == ENOENT)
803 lock->force_write = 1;
804 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
805 lock->force_write = 1;
806
807 if (safe_create_leading_directories(ref_file)) {
808 last_errno = errno;
809 error("unable to create directory for %s", ref_file);
810 goto error_return;
811 }
812 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
813
814 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
815
816 error_return:
817 unlock_ref(lock);
818 errno = last_errno;
819 return NULL;
820 }
821
822 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
823 {
824 char refpath[PATH_MAX];
825 if (check_ref_format(ref))
826 return NULL;
827 strcpy(refpath, mkpath("refs/%s", ref));
828 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
829 }
830
831 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
832 {
833 if (check_ref_format(ref) == -1)
834 return NULL;
835 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
836 }
837
838 static struct lock_file packlock;
839
840 static int repack_without_ref(const char *refname)
841 {
842 struct ref_list *list, *packed_ref_list;
843 int fd;
844 int found = 0;
845
846 packed_ref_list = get_packed_refs();
847 for (list = packed_ref_list; list; list = list->next) {
848 if (!strcmp(refname, list->name)) {
849 found = 1;
850 break;
851 }
852 }
853 if (!found)
854 return 0;
855 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
856 if (fd < 0)
857 return error("cannot delete '%s' from packed refs", refname);
858
859 for (list = packed_ref_list; list; list = list->next) {
860 char line[PATH_MAX + 100];
861 int len;
862
863 if (!strcmp(refname, list->name))
864 continue;
865 len = snprintf(line, sizeof(line), "%s %s\n",
866 sha1_to_hex(list->sha1), list->name);
867 /* this should not happen but just being defensive */
868 if (len > sizeof(line))
869 die("too long a refname '%s'", list->name);
870 write_or_die(fd, line, len);
871 }
872 return commit_lock_file(&packlock);
873 }
874
875 int delete_ref(const char *refname, const unsigned char *sha1)
876 {
877 struct ref_lock *lock;
878 int err, i, ret = 0, flag = 0;
879
880 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
881 if (!lock)
882 return 1;
883 if (!(flag & REF_ISPACKED)) {
884 /* loose */
885 i = strlen(lock->lk->filename) - 5; /* .lock */
886 lock->lk->filename[i] = 0;
887 err = unlink(lock->lk->filename);
888 if (err) {
889 ret = 1;
890 error("unlink(%s) failed: %s",
891 lock->lk->filename, strerror(errno));
892 }
893 lock->lk->filename[i] = '.';
894 }
895 /* removing the loose one could have resurrected an earlier
896 * packed one. Also, if it was not loose we need to repack
897 * without it.
898 */
899 ret |= repack_without_ref(refname);
900
901 err = unlink(git_path("logs/%s", lock->ref_name));
902 if (err && errno != ENOENT)
903 fprintf(stderr, "warning: unlink(%s) failed: %s",
904 git_path("logs/%s", lock->ref_name), strerror(errno));
905 invalidate_cached_refs();
906 unlock_ref(lock);
907 return ret;
908 }
909
910 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
911 {
912 static const char renamed_ref[] = "RENAMED-REF";
913 unsigned char sha1[20], orig_sha1[20];
914 int flag = 0, logmoved = 0;
915 struct ref_lock *lock;
916 struct stat loginfo;
917 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
918
919 if (S_ISLNK(loginfo.st_mode))
920 return error("reflog for %s is a symlink", oldref);
921
922 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
923 return error("refname %s not found", oldref);
924
925 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
926 return 1;
927
928 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
929 return 1;
930
931 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
932 if (!lock)
933 return error("unable to lock %s", renamed_ref);
934 lock->force_write = 1;
935 if (write_ref_sha1(lock, orig_sha1, logmsg))
936 return error("unable to save current sha1 in %s", renamed_ref);
937
938 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
939 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
940 oldref, strerror(errno));
941
942 if (delete_ref(oldref, orig_sha1)) {
943 error("unable to delete old %s", oldref);
944 goto rollback;
945 }
946
947 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
948 if (errno==EISDIR) {
949 if (remove_empty_directories(git_path("%s", newref))) {
950 error("Directory not empty: %s", newref);
951 goto rollback;
952 }
953 } else {
954 error("unable to delete existing %s", newref);
955 goto rollback;
956 }
957 }
958
959 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
960 error("unable to create directory for %s", newref);
961 goto rollback;
962 }
963
964 retry:
965 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
966 if (errno==EISDIR || errno==ENOTDIR) {
967 /*
968 * rename(a, b) when b is an existing
969 * directory ought to result in ISDIR, but
970 * Solaris 5.8 gives ENOTDIR. Sheesh.
971 */
972 if (remove_empty_directories(git_path("logs/%s", newref))) {
973 error("Directory not empty: logs/%s", newref);
974 goto rollback;
975 }
976 goto retry;
977 } else {
978 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
979 newref, strerror(errno));
980 goto rollback;
981 }
982 }
983 logmoved = log;
984
985 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
986 if (!lock) {
987 error("unable to lock %s for update", newref);
988 goto rollback;
989 }
990
991 lock->force_write = 1;
992 hashcpy(lock->old_sha1, orig_sha1);
993 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
994 error("unable to write current sha1 into %s", newref);
995 goto rollback;
996 }
997
998 return 0;
999
1000 rollback:
1001 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1002 if (!lock) {
1003 error("unable to lock %s for rollback", oldref);
1004 goto rollbacklog;
1005 }
1006
1007 lock->force_write = 1;
1008 flag = log_all_ref_updates;
1009 log_all_ref_updates = 0;
1010 if (write_ref_sha1(lock, orig_sha1, NULL))
1011 error("unable to write current sha1 into %s", oldref);
1012 log_all_ref_updates = flag;
1013
1014 rollbacklog:
1015 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1016 error("unable to restore logfile %s from %s: %s",
1017 oldref, newref, strerror(errno));
1018 if (!logmoved && log &&
1019 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1020 error("unable to restore logfile %s from tmp-renamed-log: %s",
1021 oldref, strerror(errno));
1022
1023 return 1;
1024 }
1025
1026 void unlock_ref(struct ref_lock *lock)
1027 {
1028 if (lock->lock_fd >= 0) {
1029 close(lock->lock_fd);
1030 /* Do not free lock->lk -- atexit() still looks at them */
1031 if (lock->lk)
1032 rollback_lock_file(lock->lk);
1033 }
1034 free(lock->ref_name);
1035 free(lock->orig_ref_name);
1036 free(lock);
1037 }
1038
1039 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1040 const unsigned char *new_sha1, const char *msg)
1041 {
1042 int logfd, written, oflags = O_APPEND | O_WRONLY;
1043 unsigned maxlen, len;
1044 int msglen;
1045 char *log_file, *logrec;
1046 const char *committer;
1047
1048 if (log_all_ref_updates < 0)
1049 log_all_ref_updates = !is_bare_repository();
1050
1051 log_file = git_path("logs/%s", ref_name);
1052
1053 if (log_all_ref_updates &&
1054 (!prefixcmp(ref_name, "refs/heads/") ||
1055 !prefixcmp(ref_name, "refs/remotes/") ||
1056 !strcmp(ref_name, "HEAD"))) {
1057 if (safe_create_leading_directories(log_file) < 0)
1058 return error("unable to create directory for %s",
1059 log_file);
1060 oflags |= O_CREAT;
1061 }
1062
1063 logfd = open(log_file, oflags, 0666);
1064 if (logfd < 0) {
1065 if (!(oflags & O_CREAT) && errno == ENOENT)
1066 return 0;
1067
1068 if ((oflags & O_CREAT) && errno == EISDIR) {
1069 if (remove_empty_directories(log_file)) {
1070 return error("There are still logs under '%s'",
1071 log_file);
1072 }
1073 logfd = open(log_file, oflags, 0666);
1074 }
1075
1076 if (logfd < 0)
1077 return error("Unable to append to %s: %s",
1078 log_file, strerror(errno));
1079 }
1080
1081 adjust_shared_perm(log_file);
1082
1083 msglen = 0;
1084 if (msg) {
1085 /* clean up the message and make sure it is a single line */
1086 for ( ; *msg; msg++)
1087 if (!isspace(*msg))
1088 break;
1089 if (*msg) {
1090 const char *ep = strchr(msg, '\n');
1091 if (ep)
1092 msglen = ep - msg;
1093 else
1094 msglen = strlen(msg);
1095 }
1096 }
1097
1098 committer = git_committer_info(-1);
1099 maxlen = strlen(committer) + msglen + 100;
1100 logrec = xmalloc(maxlen);
1101 len = sprintf(logrec, "%s %s %s\n",
1102 sha1_to_hex(old_sha1),
1103 sha1_to_hex(new_sha1),
1104 committer);
1105 if (msglen)
1106 len += sprintf(logrec + len - 1, "\t%.*s\n", msglen, msg) - 1;
1107 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1108 free(logrec);
1109 close(logfd);
1110 if (written != len)
1111 return error("Unable to append to %s", log_file);
1112 return 0;
1113 }
1114
1115 int write_ref_sha1(struct ref_lock *lock,
1116 const unsigned char *sha1, const char *logmsg)
1117 {
1118 static char term = '\n';
1119
1120 if (!lock)
1121 return -1;
1122 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1123 unlock_ref(lock);
1124 return 0;
1125 }
1126 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1127 write_in_full(lock->lock_fd, &term, 1) != 1
1128 || close(lock->lock_fd) < 0) {
1129 error("Couldn't write %s", lock->lk->filename);
1130 unlock_ref(lock);
1131 return -1;
1132 }
1133 invalidate_cached_refs();
1134 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1135 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1136 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1137 unlock_ref(lock);
1138 return -1;
1139 }
1140 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1141 /*
1142 * Special hack: If a branch is updated directly and HEAD
1143 * points to it (may happen on the remote side of a push
1144 * for example) then logically the HEAD reflog should be
1145 * updated too.
1146 * A generic solution implies reverse symref information,
1147 * but finding all symrefs pointing to the given branch
1148 * would be rather costly for this rare event (the direct
1149 * update of a branch) to be worth it. So let's cheat and
1150 * check with HEAD only which should cover 99% of all usage
1151 * scenarios (even 100% of the default ones).
1152 */
1153 unsigned char head_sha1[20];
1154 int head_flag;
1155 const char *head_ref;
1156 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1157 if (head_ref && (head_flag & REF_ISSYMREF) &&
1158 !strcmp(head_ref, lock->ref_name))
1159 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1160 }
1161 if (commit_lock_file(lock->lk)) {
1162 error("Couldn't set %s", lock->ref_name);
1163 unlock_ref(lock);
1164 return -1;
1165 }
1166 lock->lock_fd = -1;
1167 unlock_ref(lock);
1168 return 0;
1169 }
1170
1171 int create_symref(const char *ref_target, const char *refs_heads_master,
1172 const char *logmsg)
1173 {
1174 const char *lockpath;
1175 char ref[1000];
1176 int fd, len, written;
1177 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1178 unsigned char old_sha1[20], new_sha1[20];
1179
1180 if (logmsg && read_ref(ref_target, old_sha1))
1181 hashclr(old_sha1);
1182
1183 if (safe_create_leading_directories(git_HEAD) < 0)
1184 return error("unable to create directory for %s", git_HEAD);
1185
1186 #ifndef NO_SYMLINK_HEAD
1187 if (prefer_symlink_refs) {
1188 unlink(git_HEAD);
1189 if (!symlink(refs_heads_master, git_HEAD))
1190 goto done;
1191 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1192 }
1193 #endif
1194
1195 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1196 if (sizeof(ref) <= len) {
1197 error("refname too long: %s", refs_heads_master);
1198 goto error_free_return;
1199 }
1200 lockpath = mkpath("%s.lock", git_HEAD);
1201 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1202 if (fd < 0) {
1203 error("Unable to open %s for writing", lockpath);
1204 goto error_free_return;
1205 }
1206 written = write_in_full(fd, ref, len);
1207 close(fd);
1208 if (written != len) {
1209 error("Unable to write to %s", lockpath);
1210 goto error_unlink_return;
1211 }
1212 if (rename(lockpath, git_HEAD) < 0) {
1213 error("Unable to create %s", git_HEAD);
1214 goto error_unlink_return;
1215 }
1216 if (adjust_shared_perm(git_HEAD)) {
1217 error("Unable to fix permissions on %s", lockpath);
1218 error_unlink_return:
1219 unlink(lockpath);
1220 error_free_return:
1221 free(git_HEAD);
1222 return -1;
1223 }
1224
1225 #ifndef NO_SYMLINK_HEAD
1226 done:
1227 #endif
1228 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1229 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1230
1231 free(git_HEAD);
1232 return 0;
1233 }
1234
1235 static char *ref_msg(const char *line, const char *endp)
1236 {
1237 const char *ep;
1238 char *msg;
1239
1240 line += 82;
1241 for (ep = line; ep < endp && *ep != '\n'; ep++)
1242 ;
1243 msg = xmalloc(ep - line + 1);
1244 memcpy(msg, line, ep - line);
1245 msg[ep - line] = 0;
1246 return msg;
1247 }
1248
1249 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)
1250 {
1251 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1252 char *tz_c;
1253 int logfd, tz, reccnt = 0;
1254 struct stat st;
1255 unsigned long date;
1256 unsigned char logged_sha1[20];
1257 void *log_mapped;
1258 size_t mapsz;
1259
1260 logfile = git_path("logs/%s", ref);
1261 logfd = open(logfile, O_RDONLY, 0);
1262 if (logfd < 0)
1263 die("Unable to read log %s: %s", logfile, strerror(errno));
1264 fstat(logfd, &st);
1265 if (!st.st_size)
1266 die("Log %s is empty.", logfile);
1267 mapsz = xsize_t(st.st_size);
1268 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1269 logdata = log_mapped;
1270 close(logfd);
1271
1272 lastrec = NULL;
1273 rec = logend = logdata + st.st_size;
1274 while (logdata < rec) {
1275 reccnt++;
1276 if (logdata < rec && *(rec-1) == '\n')
1277 rec--;
1278 lastgt = NULL;
1279 while (logdata < rec && *(rec-1) != '\n') {
1280 rec--;
1281 if (*rec == '>')
1282 lastgt = rec;
1283 }
1284 if (!lastgt)
1285 die("Log %s is corrupt.", logfile);
1286 date = strtoul(lastgt + 1, &tz_c, 10);
1287 if (date <= at_time || cnt == 0) {
1288 tz = strtoul(tz_c, NULL, 10);
1289 if (msg)
1290 *msg = ref_msg(rec, logend);
1291 if (cutoff_time)
1292 *cutoff_time = date;
1293 if (cutoff_tz)
1294 *cutoff_tz = tz;
1295 if (cutoff_cnt)
1296 *cutoff_cnt = reccnt - 1;
1297 if (lastrec) {
1298 if (get_sha1_hex(lastrec, logged_sha1))
1299 die("Log %s is corrupt.", logfile);
1300 if (get_sha1_hex(rec + 41, sha1))
1301 die("Log %s is corrupt.", logfile);
1302 if (hashcmp(logged_sha1, sha1)) {
1303 fprintf(stderr,
1304 "warning: Log %s has gap after %s.\n",
1305 logfile, show_rfc2822_date(date, tz));
1306 }
1307 }
1308 else if (date == at_time) {
1309 if (get_sha1_hex(rec + 41, sha1))
1310 die("Log %s is corrupt.", logfile);
1311 }
1312 else {
1313 if (get_sha1_hex(rec + 41, logged_sha1))
1314 die("Log %s is corrupt.", logfile);
1315 if (hashcmp(logged_sha1, sha1)) {
1316 fprintf(stderr,
1317 "warning: Log %s unexpectedly ended on %s.\n",
1318 logfile, show_rfc2822_date(date, tz));
1319 }
1320 }
1321 munmap(log_mapped, mapsz);
1322 return 0;
1323 }
1324 lastrec = rec;
1325 if (cnt > 0)
1326 cnt--;
1327 }
1328
1329 rec = logdata;
1330 while (rec < logend && *rec != '>' && *rec != '\n')
1331 rec++;
1332 if (rec == logend || *rec == '\n')
1333 die("Log %s is corrupt.", logfile);
1334 date = strtoul(rec + 1, &tz_c, 10);
1335 tz = strtoul(tz_c, NULL, 10);
1336 if (get_sha1_hex(logdata, sha1))
1337 die("Log %s is corrupt.", logfile);
1338 if (msg)
1339 *msg = ref_msg(logdata, logend);
1340 munmap(log_mapped, mapsz);
1341
1342 if (cutoff_time)
1343 *cutoff_time = date;
1344 if (cutoff_tz)
1345 *cutoff_tz = tz;
1346 if (cutoff_cnt)
1347 *cutoff_cnt = reccnt;
1348 return 1;
1349 }
1350
1351 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1352 {
1353 const char *logfile;
1354 FILE *logfp;
1355 char buf[1024];
1356 int ret = 0;
1357
1358 logfile = git_path("logs/%s", ref);
1359 logfp = fopen(logfile, "r");
1360 if (!logfp)
1361 return -1;
1362 while (fgets(buf, sizeof(buf), logfp)) {
1363 unsigned char osha1[20], nsha1[20];
1364 char *email_end, *message;
1365 unsigned long timestamp;
1366 int len, tz;
1367
1368 /* old SP new SP name <email> SP time TAB msg LF */
1369 len = strlen(buf);
1370 if (len < 83 || buf[len-1] != '\n' ||
1371 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1372 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1373 !(email_end = strchr(buf + 82, '>')) ||
1374 email_end[1] != ' ' ||
1375 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1376 !message || message[0] != ' ' ||
1377 (message[1] != '+' && message[1] != '-') ||
1378 !isdigit(message[2]) || !isdigit(message[3]) ||
1379 !isdigit(message[4]) || !isdigit(message[5]))
1380 continue; /* corrupt? */
1381 email_end[1] = '\0';
1382 tz = strtol(message + 1, NULL, 10);
1383 if (message[6] != '\t')
1384 message += 6;
1385 else
1386 message += 7;
1387 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1388 if (ret)
1389 break;
1390 }
1391 fclose(logfp);
1392 return ret;
1393 }
1394
1395 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1396 {
1397 DIR *dir = opendir(git_path("logs/%s", base));
1398 int retval = 0;
1399
1400 if (dir) {
1401 struct dirent *de;
1402 int baselen = strlen(base);
1403 char *log = xmalloc(baselen + 257);
1404
1405 memcpy(log, base, baselen);
1406 if (baselen && base[baselen-1] != '/')
1407 log[baselen++] = '/';
1408
1409 while ((de = readdir(dir)) != NULL) {
1410 struct stat st;
1411 int namelen;
1412
1413 if (de->d_name[0] == '.')
1414 continue;
1415 namelen = strlen(de->d_name);
1416 if (namelen > 255)
1417 continue;
1418 if (has_extension(de->d_name, ".lock"))
1419 continue;
1420 memcpy(log + baselen, de->d_name, namelen+1);
1421 if (stat(git_path("logs/%s", log), &st) < 0)
1422 continue;
1423 if (S_ISDIR(st.st_mode)) {
1424 retval = do_for_each_reflog(log, fn, cb_data);
1425 } else {
1426 unsigned char sha1[20];
1427 if (!resolve_ref(log, sha1, 0, NULL))
1428 retval = error("bad ref for %s", log);
1429 else
1430 retval = fn(log, sha1, 0, cb_data);
1431 }
1432 if (retval)
1433 break;
1434 }
1435 free(log);
1436 closedir(dir);
1437 }
1438 else if (*base)
1439 return errno;
1440 return retval;
1441 }
1442
1443 int for_each_reflog(each_ref_fn fn, void *cb_data)
1444 {
1445 return do_for_each_reflog("", fn, cb_data);
1446 }