Merge branch 'maint'
[git/git.git] / refs.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6
7 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8 #define REF_KNOWS_PEELED 04
9
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];
16 };
17
18 static const char *parse_ref_line(char *line, unsigned char *sha1)
19 {
20 /*
21 * 42: the answer to everything.
22 *
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)
27 */
28 int len = strlen(line) - 42;
29
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;
42
43 return line;
44 }
45
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)
49 {
50 int len;
51 struct ref_list *entry;
52
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;
64 }
65
66 /* merge sort the ref list */
67 static struct ref_list *sort_ref_list(struct ref_list *list)
68 {
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;
74
75 if (!list)
76 return list;
77
78 do {
79 last_merge_count = merge_count;
80 merge_count = 0;
81
82 psize = 0;
83
84 p = new_list;
85 q = new_list;
86 new_list = NULL;
87 l = NULL;
88
89 while (p) {
90 merge_count++;
91
92 while (psize < k && q->next) {
93 q = q->next;
94 psize++;
95 }
96 qsize = k;
97
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--;
129 }
130 }
131
132 e->next = NULL;
133
134 if (l)
135 l->next = e;
136 if (!new_list)
137 new_list = e;
138 l = e;
139 }
140
141 p = q;
142 };
143
144 k = k * 2;
145 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
146
147 return new_list;
148 }
149
150 /*
151 * Future: need to be in "struct repository"
152 * when doing a full libification.
153 */
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
161 static void free_ref_list(struct ref_list *list)
162 {
163 struct ref_list *next;
164 for ( ; list; list = next) {
165 next = list->next;
166 free(list);
167 }
168 }
169
170 static void invalidate_cached_refs(void)
171 {
172 struct cached_refs *ca = &cached_refs;
173
174 if (ca->did_loose && ca->loose)
175 free_ref_list(ca->loose);
176 if (ca->did_packed && ca->packed)
177 free_ref_list(ca->packed);
178 ca->loose = ca->packed = NULL;
179 ca->did_loose = ca->did_packed = 0;
180 }
181
182 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
183 {
184 struct ref_list *list = NULL;
185 struct ref_list *last = NULL;
186 char refline[PATH_MAX];
187 int flag = REF_ISPACKED;
188
189 while (fgets(refline, sizeof(refline), f)) {
190 unsigned char sha1[20];
191 const char *name;
192 static const char header[] = "# pack-refs with:";
193
194 if (!strncmp(refline, header, sizeof(header)-1)) {
195 const char *traits = refline + sizeof(header) - 1;
196 if (strstr(traits, " peeled "))
197 flag |= REF_KNOWS_PEELED;
198 /* perhaps other traits later as well */
199 continue;
200 }
201
202 name = parse_ref_line(refline, sha1);
203 if (name) {
204 list = add_ref(name, sha1, flag, list, &last);
205 continue;
206 }
207 if (last &&
208 refline[0] == '^' &&
209 strlen(refline) == 42 &&
210 refline[41] == '\n' &&
211 !get_sha1_hex(refline + 1, sha1))
212 hashcpy(last->peeled, sha1);
213 }
214 cached_refs->packed = sort_ref_list(list);
215 }
216
217 static struct ref_list *get_packed_refs(void)
218 {
219 if (!cached_refs.did_packed) {
220 FILE *f = fopen(git_path("packed-refs"), "r");
221 cached_refs.packed = NULL;
222 if (f) {
223 read_packed_refs(f, &cached_refs);
224 fclose(f);
225 }
226 cached_refs.did_packed = 1;
227 }
228 return cached_refs.packed;
229 }
230
231 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
232 {
233 DIR *dir = opendir(git_path("%s", base));
234
235 if (dir) {
236 struct dirent *de;
237 int baselen = strlen(base);
238 char *ref = xmalloc(baselen + 257);
239
240 memcpy(ref, base, baselen);
241 if (baselen && base[baselen-1] != '/')
242 ref[baselen++] = '/';
243
244 while ((de = readdir(dir)) != NULL) {
245 unsigned char sha1[20];
246 struct stat st;
247 int flag;
248 int namelen;
249
250 if (de->d_name[0] == '.')
251 continue;
252 namelen = strlen(de->d_name);
253 if (namelen > 255)
254 continue;
255 if (has_extension(de->d_name, ".lock"))
256 continue;
257 memcpy(ref + baselen, de->d_name, namelen+1);
258 if (stat(git_path("%s", ref), &st) < 0)
259 continue;
260 if (S_ISDIR(st.st_mode)) {
261 list = get_ref_dir(ref, list);
262 continue;
263 }
264 if (!resolve_ref(ref, sha1, 1, &flag)) {
265 error("%s points nowhere!", ref);
266 continue;
267 }
268 list = add_ref(ref, sha1, flag, list, NULL);
269 }
270 free(ref);
271 closedir(dir);
272 }
273 return sort_ref_list(list);
274 }
275
276 static struct ref_list *get_loose_refs(void)
277 {
278 if (!cached_refs.did_loose) {
279 cached_refs.loose = get_ref_dir("refs", NULL);
280 cached_refs.did_loose = 1;
281 }
282 return cached_refs.loose;
283 }
284
285 /* We allow "recursive" symbolic refs. Only within reason, though */
286 #define MAXDEPTH 5
287 #define MAXREFLEN (1024)
288
289 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
290 {
291 FILE *f;
292 struct cached_refs refs;
293 struct ref_list *ref;
294 int retval;
295
296 strcpy(name + pathlen, "packed-refs");
297 f = fopen(name, "r");
298 if (!f)
299 return -1;
300 read_packed_refs(f, &refs);
301 fclose(f);
302 ref = refs.packed;
303 retval = -1;
304 while (ref) {
305 if (!strcmp(ref->name, refname)) {
306 retval = 0;
307 memcpy(result, ref->sha1, 20);
308 break;
309 }
310 ref = ref->next;
311 }
312 free_ref_list(refs.packed);
313 return retval;
314 }
315
316 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
317 {
318 int fd, len = strlen(refname);
319 char buffer[128], *p;
320
321 if (recursion > MAXDEPTH || len > MAXREFLEN)
322 return -1;
323 memcpy(name + pathlen, refname, len+1);
324 fd = open(name, O_RDONLY);
325 if (fd < 0)
326 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
327
328 len = read(fd, buffer, sizeof(buffer)-1);
329 close(fd);
330 if (len < 0)
331 return -1;
332 while (len && isspace(buffer[len-1]))
333 len--;
334 buffer[len] = 0;
335
336 /* Was it a detached head or an old-fashioned symlink? */
337 if (!get_sha1_hex(buffer, result))
338 return 0;
339
340 /* Symref? */
341 if (strncmp(buffer, "ref:", 4))
342 return -1;
343 p = buffer + 4;
344 while (isspace(*p))
345 p++;
346
347 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
348 }
349
350 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
351 {
352 int len = strlen(path), retval;
353 char *gitdir;
354
355 while (len && path[len-1] == '/')
356 len--;
357 if (!len)
358 return -1;
359 gitdir = xmalloc(len + MAXREFLEN + 8);
360 memcpy(gitdir, path, len);
361 memcpy(gitdir + len, "/.git/", 7);
362
363 retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
364 free(gitdir);
365 return retval;
366 }
367
368 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
369 {
370 int depth = MAXDEPTH, len;
371 char buffer[256];
372 static char ref_buffer[256];
373
374 if (flag)
375 *flag = 0;
376
377 for (;;) {
378 const char *path = git_path("%s", ref);
379 struct stat st;
380 char *buf;
381 int fd;
382
383 if (--depth < 0)
384 return NULL;
385
386 /* Special case: non-existing file.
387 * Not having the refs/heads/new-branch is OK
388 * if we are writing into it, so is .git/HEAD
389 * that points at refs/heads/master still to be
390 * born. It is NOT OK if we are resolving for
391 * reading.
392 */
393 if (lstat(path, &st) < 0) {
394 struct ref_list *list = get_packed_refs();
395 while (list) {
396 if (!strcmp(ref, list->name)) {
397 hashcpy(sha1, list->sha1);
398 if (flag)
399 *flag |= REF_ISPACKED;
400 return ref;
401 }
402 list = list->next;
403 }
404 if (reading || errno != ENOENT)
405 return NULL;
406 hashclr(sha1);
407 return ref;
408 }
409
410 /* Follow "normalized" - ie "refs/.." symlinks by hand */
411 if (S_ISLNK(st.st_mode)) {
412 len = readlink(path, buffer, sizeof(buffer)-1);
413 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
414 buffer[len] = 0;
415 strcpy(ref_buffer, buffer);
416 ref = ref_buffer;
417 if (flag)
418 *flag |= REF_ISSYMREF;
419 continue;
420 }
421 }
422
423 /* Is it a directory? */
424 if (S_ISDIR(st.st_mode)) {
425 errno = EISDIR;
426 return NULL;
427 }
428
429 /*
430 * Anything else, just open it and try to use it as
431 * a ref
432 */
433 fd = open(path, O_RDONLY);
434 if (fd < 0)
435 return NULL;
436 len = read_in_full(fd, buffer, sizeof(buffer)-1);
437 close(fd);
438
439 /*
440 * Is it a symbolic ref?
441 */
442 if (len < 4 || memcmp("ref:", buffer, 4))
443 break;
444 buf = buffer + 4;
445 len -= 4;
446 while (len && isspace(*buf))
447 buf++, len--;
448 while (len && isspace(buf[len-1]))
449 len--;
450 buf[len] = 0;
451 memcpy(ref_buffer, buf, len + 1);
452 ref = ref_buffer;
453 if (flag)
454 *flag |= REF_ISSYMREF;
455 }
456 if (len < 40 || get_sha1_hex(buffer, sha1))
457 return NULL;
458 return ref;
459 }
460
461 int read_ref(const char *ref, unsigned char *sha1)
462 {
463 if (resolve_ref(ref, sha1, 1, NULL))
464 return 0;
465 return -1;
466 }
467
468 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
469 void *cb_data, struct ref_list *entry)
470 {
471 if (strncmp(base, entry->name, trim))
472 return 0;
473 if (is_null_sha1(entry->sha1))
474 return 0;
475 if (!has_sha1_file(entry->sha1)) {
476 error("%s does not point to a valid object!", entry->name);
477 return 0;
478 }
479 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
480 }
481
482 int peel_ref(const char *ref, unsigned char *sha1)
483 {
484 int flag;
485 unsigned char base[20];
486 struct object *o;
487
488 if (!resolve_ref(ref, base, 1, &flag))
489 return -1;
490
491 if ((flag & REF_ISPACKED)) {
492 struct ref_list *list = get_packed_refs();
493
494 while (list) {
495 if (!strcmp(list->name, ref)) {
496 if (list->flag & REF_KNOWS_PEELED) {
497 hashcpy(sha1, list->peeled);
498 return 0;
499 }
500 /* older pack-refs did not leave peeled ones */
501 break;
502 }
503 list = list->next;
504 }
505 }
506
507 /* fallback - callers should not call this for unpacked refs */
508 o = parse_object(base);
509 if (o->type == OBJ_TAG) {
510 o = deref_tag(o, ref, 0);
511 if (o) {
512 hashcpy(sha1, o->sha1);
513 return 0;
514 }
515 }
516 return -1;
517 }
518
519 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
520 void *cb_data)
521 {
522 int retval;
523 struct ref_list *packed = get_packed_refs();
524 struct ref_list *loose = get_loose_refs();
525
526 while (packed && loose) {
527 struct ref_list *entry;
528 int cmp = strcmp(packed->name, loose->name);
529 if (!cmp) {
530 packed = packed->next;
531 continue;
532 }
533 if (cmp > 0) {
534 entry = loose;
535 loose = loose->next;
536 } else {
537 entry = packed;
538 packed = packed->next;
539 }
540 retval = do_one_ref(base, fn, trim, cb_data, entry);
541 if (retval)
542 return retval;
543 }
544
545 for (packed = packed ? packed : loose; packed; packed = packed->next) {
546 retval = do_one_ref(base, fn, trim, cb_data, packed);
547 if (retval)
548 return retval;
549 }
550 return 0;
551 }
552
553 int head_ref(each_ref_fn fn, void *cb_data)
554 {
555 unsigned char sha1[20];
556 int flag;
557
558 if (resolve_ref("HEAD", sha1, 1, &flag))
559 return fn("HEAD", sha1, flag, cb_data);
560 return 0;
561 }
562
563 int for_each_ref(each_ref_fn fn, void *cb_data)
564 {
565 return do_for_each_ref("refs/", fn, 0, cb_data);
566 }
567
568 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
569 {
570 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
571 }
572
573 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
574 {
575 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
576 }
577
578 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
579 {
580 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
581 }
582
583 /*
584 * Make sure "ref" is something reasonable to have under ".git/refs/";
585 * We do not like it if:
586 *
587 * - any path component of it begins with ".", or
588 * - it has double dots "..", or
589 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
590 * - it ends with a "/".
591 */
592
593 static inline int bad_ref_char(int ch)
594 {
595 if (((unsigned) ch) <= ' ' ||
596 ch == '~' || ch == '^' || ch == ':')
597 return 1;
598 /* 2.13 Pattern Matching Notation */
599 if (ch == '?' || ch == '[') /* Unsupported */
600 return 1;
601 if (ch == '*') /* Supported at the end */
602 return 2;
603 return 0;
604 }
605
606 int check_ref_format(const char *ref)
607 {
608 int ch, level, bad_type;
609 const char *cp = ref;
610
611 level = 0;
612 while (1) {
613 while ((ch = *cp++) == '/')
614 ; /* tolerate duplicated slashes */
615 if (!ch)
616 return -1; /* should not end with slashes */
617
618 /* we are at the beginning of the path component */
619 if (ch == '.')
620 return -1;
621 bad_type = bad_ref_char(ch);
622 if (bad_type) {
623 return (bad_type == 2 && !*cp) ? -3 : -1;
624 }
625
626 /* scan the rest of the path component */
627 while ((ch = *cp++) != 0) {
628 bad_type = bad_ref_char(ch);
629 if (bad_type) {
630 return (bad_type == 2 && !*cp) ? -3 : -1;
631 }
632 if (ch == '/')
633 break;
634 if (ch == '.' && *cp == '.')
635 return -1;
636 }
637 level++;
638 if (!ch) {
639 if (level < 2)
640 return -2; /* at least of form "heads/blah" */
641 return 0;
642 }
643 }
644 }
645
646 static struct ref_lock *verify_lock(struct ref_lock *lock,
647 const unsigned char *old_sha1, int mustexist)
648 {
649 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
650 error("Can't verify ref %s", lock->ref_name);
651 unlock_ref(lock);
652 return NULL;
653 }
654 if (hashcmp(lock->old_sha1, old_sha1)) {
655 error("Ref %s is at %s but expected %s", lock->ref_name,
656 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
657 unlock_ref(lock);
658 return NULL;
659 }
660 return lock;
661 }
662
663 static int remove_empty_directories(const char *file)
664 {
665 /* we want to create a file but there is a directory there;
666 * if that is an empty directory (or a directory that contains
667 * only empty directories), remove them.
668 */
669 struct strbuf path;
670 int result;
671
672 strbuf_init(&path, 20);
673 strbuf_addstr(&path, file);
674
675 result = remove_dir_recursively(&path, 1);
676
677 strbuf_release(&path);
678
679 return result;
680 }
681
682 static int is_refname_available(const char *ref, const char *oldref,
683 struct ref_list *list, int quiet)
684 {
685 int namlen = strlen(ref); /* e.g. 'foo/bar' */
686 while (list) {
687 /* list->name could be 'foo' or 'foo/bar/baz' */
688 if (!oldref || strcmp(oldref, list->name)) {
689 int len = strlen(list->name);
690 int cmplen = (namlen < len) ? namlen : len;
691 const char *lead = (namlen < len) ? list->name : ref;
692 if (!strncmp(ref, list->name, cmplen) &&
693 lead[cmplen] == '/') {
694 if (!quiet)
695 error("'%s' exists; cannot create '%s'",
696 list->name, ref);
697 return 0;
698 }
699 }
700 list = list->next;
701 }
702 return 1;
703 }
704
705 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
706 {
707 char *ref_file;
708 const char *orig_ref = ref;
709 struct ref_lock *lock;
710 struct stat st;
711 int last_errno = 0;
712 int type;
713 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
714
715 lock = xcalloc(1, sizeof(struct ref_lock));
716 lock->lock_fd = -1;
717
718 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
719 if (!ref && errno == EISDIR) {
720 /* we are trying to lock foo but we used to
721 * have foo/bar which now does not exist;
722 * it is normal for the empty directory 'foo'
723 * to remain.
724 */
725 ref_file = git_path("%s", orig_ref);
726 if (remove_empty_directories(ref_file)) {
727 last_errno = errno;
728 error("there are still refs under '%s'", orig_ref);
729 goto error_return;
730 }
731 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
732 }
733 if (type_p)
734 *type_p = type;
735 if (!ref) {
736 last_errno = errno;
737 error("unable to resolve reference %s: %s",
738 orig_ref, strerror(errno));
739 goto error_return;
740 }
741 /* When the ref did not exist and we are creating it,
742 * make sure there is no existing ref that is packed
743 * whose name begins with our refname, nor a ref whose
744 * name is a proper prefix of our refname.
745 */
746 if (is_null_sha1(lock->old_sha1) &&
747 !is_refname_available(ref, NULL, get_packed_refs(), 0))
748 goto error_return;
749
750 lock->lk = xcalloc(1, sizeof(struct lock_file));
751
752 if (flags & REF_NODEREF)
753 ref = orig_ref;
754 lock->ref_name = xstrdup(ref);
755 lock->orig_ref_name = xstrdup(orig_ref);
756 ref_file = git_path("%s", ref);
757 if (lstat(ref_file, &st) && errno == ENOENT)
758 lock->force_write = 1;
759 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
760 lock->force_write = 1;
761
762 if (safe_create_leading_directories(ref_file)) {
763 last_errno = errno;
764 error("unable to create directory for %s", ref_file);
765 goto error_return;
766 }
767 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
768
769 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
770
771 error_return:
772 unlock_ref(lock);
773 errno = last_errno;
774 return NULL;
775 }
776
777 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
778 {
779 char refpath[PATH_MAX];
780 if (check_ref_format(ref))
781 return NULL;
782 strcpy(refpath, mkpath("refs/%s", ref));
783 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
784 }
785
786 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
787 {
788 if (check_ref_format(ref) == -1)
789 return NULL;
790 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
791 }
792
793 static struct lock_file packlock;
794
795 static int repack_without_ref(const char *refname)
796 {
797 struct ref_list *list, *packed_ref_list;
798 int fd;
799 int found = 0;
800
801 packed_ref_list = get_packed_refs();
802 for (list = packed_ref_list; list; list = list->next) {
803 if (!strcmp(refname, list->name)) {
804 found = 1;
805 break;
806 }
807 }
808 if (!found)
809 return 0;
810 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
811 if (fd < 0)
812 return error("cannot delete '%s' from packed refs", refname);
813
814 for (list = packed_ref_list; list; list = list->next) {
815 char line[PATH_MAX + 100];
816 int len;
817
818 if (!strcmp(refname, list->name))
819 continue;
820 len = snprintf(line, sizeof(line), "%s %s\n",
821 sha1_to_hex(list->sha1), list->name);
822 /* this should not happen but just being defensive */
823 if (len > sizeof(line))
824 die("too long a refname '%s'", list->name);
825 write_or_die(fd, line, len);
826 }
827 close(fd);
828 return commit_lock_file(&packlock);
829 }
830
831 int delete_ref(const char *refname, const unsigned char *sha1)
832 {
833 struct ref_lock *lock;
834 int err, i, ret = 0, flag = 0;
835
836 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
837 if (!lock)
838 return 1;
839 if (!(flag & REF_ISPACKED)) {
840 /* loose */
841 i = strlen(lock->lk->filename) - 5; /* .lock */
842 lock->lk->filename[i] = 0;
843 err = unlink(lock->lk->filename);
844 if (err) {
845 ret = 1;
846 error("unlink(%s) failed: %s",
847 lock->lk->filename, strerror(errno));
848 }
849 lock->lk->filename[i] = '.';
850 }
851 /* removing the loose one could have resurrected an earlier
852 * packed one. Also, if it was not loose we need to repack
853 * without it.
854 */
855 ret |= repack_without_ref(refname);
856
857 err = unlink(git_path("logs/%s", lock->ref_name));
858 if (err && errno != ENOENT)
859 fprintf(stderr, "warning: unlink(%s) failed: %s",
860 git_path("logs/%s", lock->ref_name), strerror(errno));
861 invalidate_cached_refs();
862 unlock_ref(lock);
863 return ret;
864 }
865
866 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
867 {
868 static const char renamed_ref[] = "RENAMED-REF";
869 unsigned char sha1[20], orig_sha1[20];
870 int flag = 0, logmoved = 0;
871 struct ref_lock *lock;
872 struct stat loginfo;
873 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
874
875 if (S_ISLNK(loginfo.st_mode))
876 return error("reflog for %s is a symlink", oldref);
877
878 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
879 return error("refname %s not found", oldref);
880
881 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
882 return 1;
883
884 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
885 return 1;
886
887 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
888 if (!lock)
889 return error("unable to lock %s", renamed_ref);
890 lock->force_write = 1;
891 if (write_ref_sha1(lock, orig_sha1, logmsg))
892 return error("unable to save current sha1 in %s", renamed_ref);
893
894 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
895 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
896 oldref, strerror(errno));
897
898 if (delete_ref(oldref, orig_sha1)) {
899 error("unable to delete old %s", oldref);
900 goto rollback;
901 }
902
903 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
904 if (errno==EISDIR) {
905 if (remove_empty_directories(git_path("%s", newref))) {
906 error("Directory not empty: %s", newref);
907 goto rollback;
908 }
909 } else {
910 error("unable to delete existing %s", newref);
911 goto rollback;
912 }
913 }
914
915 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
916 error("unable to create directory for %s", newref);
917 goto rollback;
918 }
919
920 retry:
921 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
922 if (errno==EISDIR || errno==ENOTDIR) {
923 /*
924 * rename(a, b) when b is an existing
925 * directory ought to result in ISDIR, but
926 * Solaris 5.8 gives ENOTDIR. Sheesh.
927 */
928 if (remove_empty_directories(git_path("logs/%s", newref))) {
929 error("Directory not empty: logs/%s", newref);
930 goto rollback;
931 }
932 goto retry;
933 } else {
934 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
935 newref, strerror(errno));
936 goto rollback;
937 }
938 }
939 logmoved = log;
940
941 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
942 if (!lock) {
943 error("unable to lock %s for update", newref);
944 goto rollback;
945 }
946
947 lock->force_write = 1;
948 hashcpy(lock->old_sha1, orig_sha1);
949 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
950 error("unable to write current sha1 into %s", newref);
951 goto rollback;
952 }
953
954 return 0;
955
956 rollback:
957 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
958 if (!lock) {
959 error("unable to lock %s for rollback", oldref);
960 goto rollbacklog;
961 }
962
963 lock->force_write = 1;
964 flag = log_all_ref_updates;
965 log_all_ref_updates = 0;
966 if (write_ref_sha1(lock, orig_sha1, NULL))
967 error("unable to write current sha1 into %s", oldref);
968 log_all_ref_updates = flag;
969
970 rollbacklog:
971 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
972 error("unable to restore logfile %s from %s: %s",
973 oldref, newref, strerror(errno));
974 if (!logmoved && log &&
975 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
976 error("unable to restore logfile %s from tmp-renamed-log: %s",
977 oldref, strerror(errno));
978
979 return 1;
980 }
981
982 void unlock_ref(struct ref_lock *lock)
983 {
984 if (lock->lock_fd >= 0) {
985 close(lock->lock_fd);
986 /* Do not free lock->lk -- atexit() still looks at them */
987 if (lock->lk)
988 rollback_lock_file(lock->lk);
989 }
990 free(lock->ref_name);
991 free(lock->orig_ref_name);
992 free(lock);
993 }
994
995 /*
996 * copy the reflog message msg to buf, which has been allocated sufficiently
997 * large, while cleaning up the whitespaces. Especially, convert LF to space,
998 * because reflog file is one line per entry.
999 */
1000 static int copy_msg(char *buf, const char *msg)
1001 {
1002 char *cp = buf;
1003 char c;
1004 int wasspace = 1;
1005
1006 *cp++ = '\t';
1007 while ((c = *msg++)) {
1008 if (wasspace && isspace(c))
1009 continue;
1010 wasspace = isspace(c);
1011 if (wasspace)
1012 c = ' ';
1013 *cp++ = c;
1014 }
1015 while (buf < cp && isspace(cp[-1]))
1016 cp--;
1017 *cp++ = '\n';
1018 return cp - buf;
1019 }
1020
1021 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1022 const unsigned char *new_sha1, const char *msg)
1023 {
1024 int logfd, written, oflags = O_APPEND | O_WRONLY;
1025 unsigned maxlen, len;
1026 int msglen;
1027 char *log_file, *logrec;
1028 const char *committer;
1029
1030 if (log_all_ref_updates < 0)
1031 log_all_ref_updates = !is_bare_repository();
1032
1033 log_file = git_path("logs/%s", ref_name);
1034
1035 if (log_all_ref_updates &&
1036 (!prefixcmp(ref_name, "refs/heads/") ||
1037 !prefixcmp(ref_name, "refs/remotes/") ||
1038 !strcmp(ref_name, "HEAD"))) {
1039 if (safe_create_leading_directories(log_file) < 0)
1040 return error("unable to create directory for %s",
1041 log_file);
1042 oflags |= O_CREAT;
1043 }
1044
1045 logfd = open(log_file, oflags, 0666);
1046 if (logfd < 0) {
1047 if (!(oflags & O_CREAT) && errno == ENOENT)
1048 return 0;
1049
1050 if ((oflags & O_CREAT) && errno == EISDIR) {
1051 if (remove_empty_directories(log_file)) {
1052 return error("There are still logs under '%s'",
1053 log_file);
1054 }
1055 logfd = open(log_file, oflags, 0666);
1056 }
1057
1058 if (logfd < 0)
1059 return error("Unable to append to %s: %s",
1060 log_file, strerror(errno));
1061 }
1062
1063 adjust_shared_perm(log_file);
1064
1065 msglen = msg ? strlen(msg) : 0;
1066 committer = git_committer_info(-1);
1067 maxlen = strlen(committer) + msglen + 100;
1068 logrec = xmalloc(maxlen);
1069 len = sprintf(logrec, "%s %s %s\n",
1070 sha1_to_hex(old_sha1),
1071 sha1_to_hex(new_sha1),
1072 committer);
1073 if (msglen)
1074 len += copy_msg(logrec + len - 1, msg) - 1;
1075 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1076 free(logrec);
1077 if (close(logfd) != 0 || written != len)
1078 return error("Unable to append to %s", log_file);
1079 return 0;
1080 }
1081
1082 int write_ref_sha1(struct ref_lock *lock,
1083 const unsigned char *sha1, const char *logmsg)
1084 {
1085 static char term = '\n';
1086
1087 if (!lock)
1088 return -1;
1089 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1090 unlock_ref(lock);
1091 return 0;
1092 }
1093 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1094 write_in_full(lock->lock_fd, &term, 1) != 1
1095 || close(lock->lock_fd) < 0) {
1096 error("Couldn't write %s", lock->lk->filename);
1097 unlock_ref(lock);
1098 return -1;
1099 }
1100 invalidate_cached_refs();
1101 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1102 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1103 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1104 unlock_ref(lock);
1105 return -1;
1106 }
1107 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1108 /*
1109 * Special hack: If a branch is updated directly and HEAD
1110 * points to it (may happen on the remote side of a push
1111 * for example) then logically the HEAD reflog should be
1112 * updated too.
1113 * A generic solution implies reverse symref information,
1114 * but finding all symrefs pointing to the given branch
1115 * would be rather costly for this rare event (the direct
1116 * update of a branch) to be worth it. So let's cheat and
1117 * check with HEAD only which should cover 99% of all usage
1118 * scenarios (even 100% of the default ones).
1119 */
1120 unsigned char head_sha1[20];
1121 int head_flag;
1122 const char *head_ref;
1123 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1124 if (head_ref && (head_flag & REF_ISSYMREF) &&
1125 !strcmp(head_ref, lock->ref_name))
1126 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1127 }
1128 if (commit_lock_file(lock->lk)) {
1129 error("Couldn't set %s", lock->ref_name);
1130 unlock_ref(lock);
1131 return -1;
1132 }
1133 lock->lock_fd = -1;
1134 unlock_ref(lock);
1135 return 0;
1136 }
1137
1138 int create_symref(const char *ref_target, const char *refs_heads_master,
1139 const char *logmsg)
1140 {
1141 const char *lockpath;
1142 char ref[1000];
1143 int fd, len, written;
1144 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1145 unsigned char old_sha1[20], new_sha1[20];
1146
1147 if (logmsg && read_ref(ref_target, old_sha1))
1148 hashclr(old_sha1);
1149
1150 if (safe_create_leading_directories(git_HEAD) < 0)
1151 return error("unable to create directory for %s", git_HEAD);
1152
1153 #ifndef NO_SYMLINK_HEAD
1154 if (prefer_symlink_refs) {
1155 unlink(git_HEAD);
1156 if (!symlink(refs_heads_master, git_HEAD))
1157 goto done;
1158 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1159 }
1160 #endif
1161
1162 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1163 if (sizeof(ref) <= len) {
1164 error("refname too long: %s", refs_heads_master);
1165 goto error_free_return;
1166 }
1167 lockpath = mkpath("%s.lock", git_HEAD);
1168 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1169 if (fd < 0) {
1170 error("Unable to open %s for writing", lockpath);
1171 goto error_free_return;
1172 }
1173 written = write_in_full(fd, ref, len);
1174 if (close(fd) != 0 || written != len) {
1175 error("Unable to write to %s", lockpath);
1176 goto error_unlink_return;
1177 }
1178 if (rename(lockpath, git_HEAD) < 0) {
1179 error("Unable to create %s", git_HEAD);
1180 goto error_unlink_return;
1181 }
1182 if (adjust_shared_perm(git_HEAD)) {
1183 error("Unable to fix permissions on %s", lockpath);
1184 error_unlink_return:
1185 unlink(lockpath);
1186 error_free_return:
1187 free(git_HEAD);
1188 return -1;
1189 }
1190
1191 #ifndef NO_SYMLINK_HEAD
1192 done:
1193 #endif
1194 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1195 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1196
1197 free(git_HEAD);
1198 return 0;
1199 }
1200
1201 static char *ref_msg(const char *line, const char *endp)
1202 {
1203 const char *ep;
1204 line += 82;
1205 ep = memchr(line, '\n', endp - line);
1206 if (!ep)
1207 ep = endp;
1208 return xmemdupz(line, ep - line);
1209 }
1210
1211 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)
1212 {
1213 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1214 char *tz_c;
1215 int logfd, tz, reccnt = 0;
1216 struct stat st;
1217 unsigned long date;
1218 unsigned char logged_sha1[20];
1219 void *log_mapped;
1220 size_t mapsz;
1221
1222 logfile = git_path("logs/%s", ref);
1223 logfd = open(logfile, O_RDONLY, 0);
1224 if (logfd < 0)
1225 die("Unable to read log %s: %s", logfile, strerror(errno));
1226 fstat(logfd, &st);
1227 if (!st.st_size)
1228 die("Log %s is empty.", logfile);
1229 mapsz = xsize_t(st.st_size);
1230 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1231 logdata = log_mapped;
1232 close(logfd);
1233
1234 lastrec = NULL;
1235 rec = logend = logdata + st.st_size;
1236 while (logdata < rec) {
1237 reccnt++;
1238 if (logdata < rec && *(rec-1) == '\n')
1239 rec--;
1240 lastgt = NULL;
1241 while (logdata < rec && *(rec-1) != '\n') {
1242 rec--;
1243 if (*rec == '>')
1244 lastgt = rec;
1245 }
1246 if (!lastgt)
1247 die("Log %s is corrupt.", logfile);
1248 date = strtoul(lastgt + 1, &tz_c, 10);
1249 if (date <= at_time || cnt == 0) {
1250 tz = strtoul(tz_c, NULL, 10);
1251 if (msg)
1252 *msg = ref_msg(rec, logend);
1253 if (cutoff_time)
1254 *cutoff_time = date;
1255 if (cutoff_tz)
1256 *cutoff_tz = tz;
1257 if (cutoff_cnt)
1258 *cutoff_cnt = reccnt - 1;
1259 if (lastrec) {
1260 if (get_sha1_hex(lastrec, logged_sha1))
1261 die("Log %s is corrupt.", logfile);
1262 if (get_sha1_hex(rec + 41, sha1))
1263 die("Log %s is corrupt.", logfile);
1264 if (hashcmp(logged_sha1, sha1)) {
1265 fprintf(stderr,
1266 "warning: Log %s has gap after %s.\n",
1267 logfile, show_date(date, tz, DATE_RFC2822));
1268 }
1269 }
1270 else if (date == at_time) {
1271 if (get_sha1_hex(rec + 41, sha1))
1272 die("Log %s is corrupt.", logfile);
1273 }
1274 else {
1275 if (get_sha1_hex(rec + 41, logged_sha1))
1276 die("Log %s is corrupt.", logfile);
1277 if (hashcmp(logged_sha1, sha1)) {
1278 fprintf(stderr,
1279 "warning: Log %s unexpectedly ended on %s.\n",
1280 logfile, show_date(date, tz, DATE_RFC2822));
1281 }
1282 }
1283 munmap(log_mapped, mapsz);
1284 return 0;
1285 }
1286 lastrec = rec;
1287 if (cnt > 0)
1288 cnt--;
1289 }
1290
1291 rec = logdata;
1292 while (rec < logend && *rec != '>' && *rec != '\n')
1293 rec++;
1294 if (rec == logend || *rec == '\n')
1295 die("Log %s is corrupt.", logfile);
1296 date = strtoul(rec + 1, &tz_c, 10);
1297 tz = strtoul(tz_c, NULL, 10);
1298 if (get_sha1_hex(logdata, sha1))
1299 die("Log %s is corrupt.", logfile);
1300 if (msg)
1301 *msg = ref_msg(logdata, logend);
1302 munmap(log_mapped, mapsz);
1303
1304 if (cutoff_time)
1305 *cutoff_time = date;
1306 if (cutoff_tz)
1307 *cutoff_tz = tz;
1308 if (cutoff_cnt)
1309 *cutoff_cnt = reccnt;
1310 return 1;
1311 }
1312
1313 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1314 {
1315 const char *logfile;
1316 FILE *logfp;
1317 char buf[1024];
1318 int ret = 0;
1319
1320 logfile = git_path("logs/%s", ref);
1321 logfp = fopen(logfile, "r");
1322 if (!logfp)
1323 return -1;
1324 while (fgets(buf, sizeof(buf), logfp)) {
1325 unsigned char osha1[20], nsha1[20];
1326 char *email_end, *message;
1327 unsigned long timestamp;
1328 int len, tz;
1329
1330 /* old SP new SP name <email> SP time TAB msg LF */
1331 len = strlen(buf);
1332 if (len < 83 || buf[len-1] != '\n' ||
1333 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1334 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1335 !(email_end = strchr(buf + 82, '>')) ||
1336 email_end[1] != ' ' ||
1337 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1338 !message || message[0] != ' ' ||
1339 (message[1] != '+' && message[1] != '-') ||
1340 !isdigit(message[2]) || !isdigit(message[3]) ||
1341 !isdigit(message[4]) || !isdigit(message[5]))
1342 continue; /* corrupt? */
1343 email_end[1] = '\0';
1344 tz = strtol(message + 1, NULL, 10);
1345 if (message[6] != '\t')
1346 message += 6;
1347 else
1348 message += 7;
1349 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1350 if (ret)
1351 break;
1352 }
1353 fclose(logfp);
1354 return ret;
1355 }
1356
1357 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1358 {
1359 DIR *dir = opendir(git_path("logs/%s", base));
1360 int retval = 0;
1361
1362 if (dir) {
1363 struct dirent *de;
1364 int baselen = strlen(base);
1365 char *log = xmalloc(baselen + 257);
1366
1367 memcpy(log, base, baselen);
1368 if (baselen && base[baselen-1] != '/')
1369 log[baselen++] = '/';
1370
1371 while ((de = readdir(dir)) != NULL) {
1372 struct stat st;
1373 int namelen;
1374
1375 if (de->d_name[0] == '.')
1376 continue;
1377 namelen = strlen(de->d_name);
1378 if (namelen > 255)
1379 continue;
1380 if (has_extension(de->d_name, ".lock"))
1381 continue;
1382 memcpy(log + baselen, de->d_name, namelen+1);
1383 if (stat(git_path("logs/%s", log), &st) < 0)
1384 continue;
1385 if (S_ISDIR(st.st_mode)) {
1386 retval = do_for_each_reflog(log, fn, cb_data);
1387 } else {
1388 unsigned char sha1[20];
1389 if (!resolve_ref(log, sha1, 0, NULL))
1390 retval = error("bad ref for %s", log);
1391 else
1392 retval = fn(log, sha1, 0, cb_data);
1393 }
1394 if (retval)
1395 break;
1396 }
1397 free(log);
1398 closedir(dir);
1399 }
1400 else if (*base)
1401 return errno;
1402 return retval;
1403 }
1404
1405 int for_each_reflog(each_ref_fn fn, void *cb_data)
1406 {
1407 return do_for_each_reflog("", fn, cb_data);
1408 }
1409
1410 int update_ref(const char *action, const char *refname,
1411 const unsigned char *sha1, const unsigned char *oldval,
1412 int flags, enum action_on_err onerr)
1413 {
1414 static struct ref_lock *lock;
1415 lock = lock_any_ref_for_update(refname, oldval, flags);
1416 if (!lock) {
1417 const char *str = "Cannot lock the ref '%s'.";
1418 switch (onerr) {
1419 case MSG_ON_ERR: error(str, refname); break;
1420 case DIE_ON_ERR: die(str, refname); break;
1421 case QUIET_ON_ERR: break;
1422 }
1423 return 1;
1424 }
1425 if (write_ref_sha1(lock, sha1, action) < 0) {
1426 const char *str = "Cannot update the ref '%s'.";
1427 switch (onerr) {
1428 case MSG_ON_ERR: error(str, refname); break;
1429 case DIE_ON_ERR: die(str, refname); break;
1430 case QUIET_ON_ERR: break;
1431 }
1432 return 1;
1433 }
1434 return 0;
1435 }