refs.c: move dwim_ref()/dwim_log() from sha1_name.c
[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 #define REF_BROKEN 010
10
11 struct ref_list {
12 struct ref_list *next;
13 unsigned char flag; /* ISSYMREF? ISPACKED? */
14 unsigned char sha1[20];
15 unsigned char peeled[20];
16 char name[FLEX_ARRAY];
17 };
18
19 static const char *parse_ref_line(char *line, unsigned char *sha1)
20 {
21 /*
22 * 42: the answer to everything.
23 *
24 * In this case, it happens to be the answer to
25 * 40 (length of sha1 hex representation)
26 * +1 (space in between hex and name)
27 * +1 (newline at the end of the line)
28 */
29 int len = strlen(line) - 42;
30
31 if (len <= 0)
32 return NULL;
33 if (get_sha1_hex(line, sha1) < 0)
34 return NULL;
35 if (!isspace(line[40]))
36 return NULL;
37 line += 41;
38 if (isspace(*line))
39 return NULL;
40 if (line[len] != '\n')
41 return NULL;
42 line[len] = 0;
43
44 return line;
45 }
46
47 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
48 int flag, struct ref_list *list,
49 struct ref_list **new_entry)
50 {
51 int len;
52 struct ref_list *entry;
53
54 /* Allocate it and add it in.. */
55 len = strlen(name) + 1;
56 entry = xmalloc(sizeof(struct ref_list) + len);
57 hashcpy(entry->sha1, sha1);
58 hashclr(entry->peeled);
59 if (check_refname_format(name, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
60 die("Reference has invalid format: '%s'", name);
61 memcpy(entry->name, name, len);
62 entry->flag = flag;
63 entry->next = list;
64 if (new_entry)
65 *new_entry = entry;
66 return entry;
67 }
68
69 /* merge sort the ref list */
70 static struct ref_list *sort_ref_list(struct ref_list *list)
71 {
72 int psize, qsize, last_merge_count, cmp;
73 struct ref_list *p, *q, *l, *e;
74 struct ref_list *new_list = list;
75 int k = 1;
76 int merge_count = 0;
77
78 if (!list)
79 return list;
80
81 do {
82 last_merge_count = merge_count;
83 merge_count = 0;
84
85 psize = 0;
86
87 p = new_list;
88 q = new_list;
89 new_list = NULL;
90 l = NULL;
91
92 while (p) {
93 merge_count++;
94
95 while (psize < k && q->next) {
96 q = q->next;
97 psize++;
98 }
99 qsize = k;
100
101 while ((psize > 0) || (qsize > 0 && q)) {
102 if (qsize == 0 || !q) {
103 e = p;
104 p = p->next;
105 psize--;
106 } else if (psize == 0) {
107 e = q;
108 q = q->next;
109 qsize--;
110 } else {
111 cmp = strcmp(q->name, p->name);
112 if (cmp < 0) {
113 e = q;
114 q = q->next;
115 qsize--;
116 } else if (cmp > 0) {
117 e = p;
118 p = p->next;
119 psize--;
120 } else {
121 if (hashcmp(q->sha1, p->sha1))
122 die("Duplicated ref, and SHA1s don't match: %s",
123 q->name);
124 warning("Duplicated ref: %s", q->name);
125 e = q;
126 q = q->next;
127 qsize--;
128 free(e);
129 e = p;
130 p = p->next;
131 psize--;
132 }
133 }
134
135 e->next = NULL;
136
137 if (l)
138 l->next = e;
139 if (!new_list)
140 new_list = e;
141 l = e;
142 }
143
144 p = q;
145 };
146
147 k = k * 2;
148 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
149
150 return new_list;
151 }
152
153 /*
154 * Future: need to be in "struct repository"
155 * when doing a full libification.
156 */
157 static struct cached_refs {
158 char did_loose;
159 char did_packed;
160 struct ref_list *loose;
161 struct ref_list *packed;
162 } cached_refs, submodule_refs;
163 static struct ref_list *current_ref;
164
165 static struct ref_list *extra_refs;
166
167 static void free_ref_list(struct ref_list *list)
168 {
169 struct ref_list *next;
170 for ( ; list; list = next) {
171 next = list->next;
172 free(list);
173 }
174 }
175
176 static void invalidate_cached_refs(void)
177 {
178 struct cached_refs *ca = &cached_refs;
179
180 if (ca->did_loose && ca->loose)
181 free_ref_list(ca->loose);
182 if (ca->did_packed && ca->packed)
183 free_ref_list(ca->packed);
184 ca->loose = ca->packed = NULL;
185 ca->did_loose = ca->did_packed = 0;
186 }
187
188 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
189 {
190 struct ref_list *list = NULL;
191 struct ref_list *last = NULL;
192 char refline[PATH_MAX];
193 int flag = REF_ISPACKED;
194
195 while (fgets(refline, sizeof(refline), f)) {
196 unsigned char sha1[20];
197 const char *name;
198 static const char header[] = "# pack-refs with:";
199
200 if (!strncmp(refline, header, sizeof(header)-1)) {
201 const char *traits = refline + sizeof(header) - 1;
202 if (strstr(traits, " peeled "))
203 flag |= REF_KNOWS_PEELED;
204 /* perhaps other traits later as well */
205 continue;
206 }
207
208 name = parse_ref_line(refline, sha1);
209 if (name) {
210 list = add_ref(name, sha1, flag, list, &last);
211 continue;
212 }
213 if (last &&
214 refline[0] == '^' &&
215 strlen(refline) == 42 &&
216 refline[41] == '\n' &&
217 !get_sha1_hex(refline + 1, sha1))
218 hashcpy(last->peeled, sha1);
219 }
220 cached_refs->packed = sort_ref_list(list);
221 }
222
223 void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
224 {
225 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
226 }
227
228 void clear_extra_refs(void)
229 {
230 free_ref_list(extra_refs);
231 extra_refs = NULL;
232 }
233
234 static struct ref_list *get_packed_refs(const char *submodule)
235 {
236 const char *packed_refs_file;
237 struct cached_refs *refs;
238
239 if (submodule) {
240 packed_refs_file = git_path_submodule(submodule, "packed-refs");
241 refs = &submodule_refs;
242 free_ref_list(refs->packed);
243 } else {
244 packed_refs_file = git_path("packed-refs");
245 refs = &cached_refs;
246 }
247
248 if (!refs->did_packed || submodule) {
249 FILE *f = fopen(packed_refs_file, "r");
250 refs->packed = NULL;
251 if (f) {
252 read_packed_refs(f, refs);
253 fclose(f);
254 }
255 refs->did_packed = 1;
256 }
257 return refs->packed;
258 }
259
260 static struct ref_list *get_ref_dir(const char *submodule, const char *base,
261 struct ref_list *list)
262 {
263 DIR *dir;
264 const char *path;
265
266 if (submodule)
267 path = git_path_submodule(submodule, "%s", base);
268 else
269 path = git_path("%s", base);
270
271
272 dir = opendir(path);
273
274 if (dir) {
275 struct dirent *de;
276 int baselen = strlen(base);
277 char *ref = xmalloc(baselen + 257);
278
279 memcpy(ref, base, baselen);
280 if (baselen && base[baselen-1] != '/')
281 ref[baselen++] = '/';
282
283 while ((de = readdir(dir)) != NULL) {
284 unsigned char sha1[20];
285 struct stat st;
286 int flag;
287 int namelen;
288 const char *refdir;
289
290 if (de->d_name[0] == '.')
291 continue;
292 namelen = strlen(de->d_name);
293 if (namelen > 255)
294 continue;
295 if (has_extension(de->d_name, ".lock"))
296 continue;
297 memcpy(ref + baselen, de->d_name, namelen+1);
298 refdir = submodule
299 ? git_path_submodule(submodule, "%s", ref)
300 : git_path("%s", ref);
301 if (stat(refdir, &st) < 0)
302 continue;
303 if (S_ISDIR(st.st_mode)) {
304 list = get_ref_dir(submodule, ref, list);
305 continue;
306 }
307 if (submodule) {
308 hashclr(sha1);
309 flag = 0;
310 if (resolve_gitlink_ref(submodule, ref, sha1) < 0) {
311 hashclr(sha1);
312 flag |= REF_BROKEN;
313 }
314 } else
315 if (!resolve_ref(ref, sha1, 1, &flag)) {
316 hashclr(sha1);
317 flag |= REF_BROKEN;
318 }
319 list = add_ref(ref, sha1, flag, list, NULL);
320 }
321 free(ref);
322 closedir(dir);
323 }
324 return sort_ref_list(list);
325 }
326
327 struct warn_if_dangling_data {
328 FILE *fp;
329 const char *refname;
330 const char *msg_fmt;
331 };
332
333 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
334 int flags, void *cb_data)
335 {
336 struct warn_if_dangling_data *d = cb_data;
337 const char *resolves_to;
338 unsigned char junk[20];
339
340 if (!(flags & REF_ISSYMREF))
341 return 0;
342
343 resolves_to = resolve_ref(refname, junk, 0, NULL);
344 if (!resolves_to || strcmp(resolves_to, d->refname))
345 return 0;
346
347 fprintf(d->fp, d->msg_fmt, refname);
348 return 0;
349 }
350
351 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
352 {
353 struct warn_if_dangling_data data;
354
355 data.fp = fp;
356 data.refname = refname;
357 data.msg_fmt = msg_fmt;
358 for_each_rawref(warn_if_dangling_symref, &data);
359 }
360
361 static struct ref_list *get_loose_refs(const char *submodule)
362 {
363 if (submodule) {
364 free_ref_list(submodule_refs.loose);
365 submodule_refs.loose = get_ref_dir(submodule, "refs", NULL);
366 return submodule_refs.loose;
367 }
368
369 if (!cached_refs.did_loose) {
370 cached_refs.loose = get_ref_dir(NULL, "refs", NULL);
371 cached_refs.did_loose = 1;
372 }
373 return cached_refs.loose;
374 }
375
376 /* We allow "recursive" symbolic refs. Only within reason, though */
377 #define MAXDEPTH 5
378 #define MAXREFLEN (1024)
379
380 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
381 {
382 FILE *f;
383 struct cached_refs refs;
384 struct ref_list *ref;
385 int retval;
386
387 strcpy(name + pathlen, "packed-refs");
388 f = fopen(name, "r");
389 if (!f)
390 return -1;
391 read_packed_refs(f, &refs);
392 fclose(f);
393 ref = refs.packed;
394 retval = -1;
395 while (ref) {
396 if (!strcmp(ref->name, refname)) {
397 retval = 0;
398 memcpy(result, ref->sha1, 20);
399 break;
400 }
401 ref = ref->next;
402 }
403 free_ref_list(refs.packed);
404 return retval;
405 }
406
407 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
408 {
409 int fd, len = strlen(refname);
410 char buffer[128], *p;
411
412 if (recursion > MAXDEPTH || len > MAXREFLEN)
413 return -1;
414 memcpy(name + pathlen, refname, len+1);
415 fd = open(name, O_RDONLY);
416 if (fd < 0)
417 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
418
419 len = read(fd, buffer, sizeof(buffer)-1);
420 close(fd);
421 if (len < 0)
422 return -1;
423 while (len && isspace(buffer[len-1]))
424 len--;
425 buffer[len] = 0;
426
427 /* Was it a detached head or an old-fashioned symlink? */
428 if (!get_sha1_hex(buffer, result))
429 return 0;
430
431 /* Symref? */
432 if (strncmp(buffer, "ref:", 4))
433 return -1;
434 p = buffer + 4;
435 while (isspace(*p))
436 p++;
437
438 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
439 }
440
441 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
442 {
443 int len = strlen(path), retval;
444 char *gitdir;
445 const char *tmp;
446
447 while (len && path[len-1] == '/')
448 len--;
449 if (!len)
450 return -1;
451 gitdir = xmalloc(len + MAXREFLEN + 8);
452 memcpy(gitdir, path, len);
453 memcpy(gitdir + len, "/.git", 6);
454 len += 5;
455
456 tmp = read_gitfile(gitdir);
457 if (tmp) {
458 free(gitdir);
459 len = strlen(tmp);
460 gitdir = xmalloc(len + MAXREFLEN + 3);
461 memcpy(gitdir, tmp, len);
462 }
463 gitdir[len] = '/';
464 gitdir[++len] = '\0';
465 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
466 free(gitdir);
467 return retval;
468 }
469
470 /*
471 * Try to read ref from the packed references. On success, set sha1
472 * and return 0; otherwise, return -1.
473 */
474 static int get_packed_ref(const char *ref, unsigned char *sha1)
475 {
476 struct ref_list *list = get_packed_refs(NULL);
477 while (list) {
478 if (!strcmp(ref, list->name)) {
479 hashcpy(sha1, list->sha1);
480 return 0;
481 }
482 list = list->next;
483 }
484 return -1;
485 }
486
487 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
488 {
489 int depth = MAXDEPTH;
490 ssize_t len;
491 char buffer[256];
492 static char ref_buffer[256];
493 char path[PATH_MAX];
494
495 if (flag)
496 *flag = 0;
497
498 if (check_refname_format(ref, REFNAME_ALLOW_ONELEVEL))
499 return NULL;
500
501 for (;;) {
502 struct stat st;
503 char *buf;
504 int fd;
505
506 if (--depth < 0)
507 return NULL;
508
509 git_snpath(path, sizeof(path), "%s", ref);
510
511 if (lstat(path, &st) < 0) {
512 if (errno != ENOENT)
513 return NULL;
514 /*
515 * The loose reference file does not exist;
516 * check for a packed reference.
517 */
518 if (!get_packed_ref(ref, sha1)) {
519 if (flag)
520 *flag |= REF_ISPACKED;
521 return ref;
522 }
523 /* The reference is not a packed reference, either. */
524 if (reading) {
525 return NULL;
526 } else {
527 hashclr(sha1);
528 return ref;
529 }
530 }
531
532 /* Follow "normalized" - ie "refs/.." symlinks by hand */
533 if (S_ISLNK(st.st_mode)) {
534 len = readlink(path, buffer, sizeof(buffer)-1);
535 if (len < 0)
536 return NULL;
537 buffer[len] = 0;
538 if (!prefixcmp(buffer, "refs/") &&
539 !check_refname_format(buffer, 0)) {
540 strcpy(ref_buffer, buffer);
541 ref = ref_buffer;
542 if (flag)
543 *flag |= REF_ISSYMREF;
544 continue;
545 }
546 }
547
548 /* Is it a directory? */
549 if (S_ISDIR(st.st_mode)) {
550 errno = EISDIR;
551 return NULL;
552 }
553
554 /*
555 * Anything else, just open it and try to use it as
556 * a ref
557 */
558 fd = open(path, O_RDONLY);
559 if (fd < 0)
560 return NULL;
561 len = read_in_full(fd, buffer, sizeof(buffer)-1);
562 close(fd);
563 if (len < 0)
564 return NULL;
565 while (len && isspace(buffer[len-1]))
566 len--;
567 buffer[len] = '\0';
568
569 /*
570 * Is it a symbolic ref?
571 */
572 if (prefixcmp(buffer, "ref:"))
573 break;
574 buf = buffer + 4;
575 while (isspace(*buf))
576 buf++;
577 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
578 warning("symbolic reference in %s is formatted incorrectly",
579 path);
580 return NULL;
581 }
582 ref = strcpy(ref_buffer, buf);
583 if (flag)
584 *flag |= REF_ISSYMREF;
585 }
586 /* Please note that FETCH_HEAD has a second line containing other data. */
587 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
588 warning("reference in %s is formatted incorrectly", path);
589 return NULL;
590 }
591 return ref;
592 }
593
594 /* The argument to filter_refs */
595 struct ref_filter {
596 const char *pattern;
597 each_ref_fn *fn;
598 void *cb_data;
599 };
600
601 int read_ref(const char *ref, unsigned char *sha1)
602 {
603 if (resolve_ref(ref, sha1, 1, NULL))
604 return 0;
605 return -1;
606 }
607
608 #define DO_FOR_EACH_INCLUDE_BROKEN 01
609 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
610 int flags, void *cb_data, struct ref_list *entry)
611 {
612 if (prefixcmp(entry->name, base))
613 return 0;
614
615 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
616 if (entry->flag & REF_BROKEN)
617 return 0; /* ignore dangling symref */
618 if (!has_sha1_file(entry->sha1)) {
619 error("%s does not point to a valid object!", entry->name);
620 return 0;
621 }
622 }
623 current_ref = entry;
624 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
625 }
626
627 static int filter_refs(const char *ref, const unsigned char *sha, int flags,
628 void *data)
629 {
630 struct ref_filter *filter = (struct ref_filter *)data;
631 if (fnmatch(filter->pattern, ref, 0))
632 return 0;
633 return filter->fn(ref, sha, flags, filter->cb_data);
634 }
635
636 int peel_ref(const char *ref, unsigned char *sha1)
637 {
638 int flag;
639 unsigned char base[20];
640 struct object *o;
641
642 if (current_ref && (current_ref->name == ref
643 || !strcmp(current_ref->name, ref))) {
644 if (current_ref->flag & REF_KNOWS_PEELED) {
645 hashcpy(sha1, current_ref->peeled);
646 return 0;
647 }
648 hashcpy(base, current_ref->sha1);
649 goto fallback;
650 }
651
652 if (!resolve_ref(ref, base, 1, &flag))
653 return -1;
654
655 if ((flag & REF_ISPACKED)) {
656 struct ref_list *list = get_packed_refs(NULL);
657
658 while (list) {
659 if (!strcmp(list->name, ref)) {
660 if (list->flag & REF_KNOWS_PEELED) {
661 hashcpy(sha1, list->peeled);
662 return 0;
663 }
664 /* older pack-refs did not leave peeled ones */
665 break;
666 }
667 list = list->next;
668 }
669 }
670
671 fallback:
672 o = parse_object(base);
673 if (o && o->type == OBJ_TAG) {
674 o = deref_tag(o, ref, 0);
675 if (o) {
676 hashcpy(sha1, o->sha1);
677 return 0;
678 }
679 }
680 return -1;
681 }
682
683 static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
684 int trim, int flags, void *cb_data)
685 {
686 int retval = 0;
687 struct ref_list *packed = get_packed_refs(submodule);
688 struct ref_list *loose = get_loose_refs(submodule);
689
690 struct ref_list *extra;
691
692 for (extra = extra_refs; extra; extra = extra->next)
693 retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
694
695 while (packed && loose) {
696 struct ref_list *entry;
697 int cmp = strcmp(packed->name, loose->name);
698 if (!cmp) {
699 packed = packed->next;
700 continue;
701 }
702 if (cmp > 0) {
703 entry = loose;
704 loose = loose->next;
705 } else {
706 entry = packed;
707 packed = packed->next;
708 }
709 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
710 if (retval)
711 goto end_each;
712 }
713
714 for (packed = packed ? packed : loose; packed; packed = packed->next) {
715 retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
716 if (retval)
717 goto end_each;
718 }
719
720 end_each:
721 current_ref = NULL;
722 return retval;
723 }
724
725
726 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
727 {
728 unsigned char sha1[20];
729 int flag;
730
731 if (submodule) {
732 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
733 return fn("HEAD", sha1, 0, cb_data);
734
735 return 0;
736 }
737
738 if (resolve_ref("HEAD", sha1, 1, &flag))
739 return fn("HEAD", sha1, flag, cb_data);
740
741 return 0;
742 }
743
744 int head_ref(each_ref_fn fn, void *cb_data)
745 {
746 return do_head_ref(NULL, fn, cb_data);
747 }
748
749 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
750 {
751 return do_head_ref(submodule, fn, cb_data);
752 }
753
754 int for_each_ref(each_ref_fn fn, void *cb_data)
755 {
756 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
757 }
758
759 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
760 {
761 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
762 }
763
764 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
765 {
766 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
767 }
768
769 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
770 each_ref_fn fn, void *cb_data)
771 {
772 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
773 }
774
775 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
776 {
777 return for_each_ref_in("refs/tags/", fn, cb_data);
778 }
779
780 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
781 {
782 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
783 }
784
785 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
786 {
787 return for_each_ref_in("refs/heads/", fn, cb_data);
788 }
789
790 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
791 {
792 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
793 }
794
795 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
796 {
797 return for_each_ref_in("refs/remotes/", fn, cb_data);
798 }
799
800 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
801 {
802 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
803 }
804
805 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
806 {
807 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
808 }
809
810 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
811 {
812 struct strbuf buf = STRBUF_INIT;
813 int ret = 0;
814 unsigned char sha1[20];
815 int flag;
816
817 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
818 if (resolve_ref(buf.buf, sha1, 1, &flag))
819 ret = fn(buf.buf, sha1, flag, cb_data);
820 strbuf_release(&buf);
821
822 return ret;
823 }
824
825 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
826 {
827 struct strbuf buf = STRBUF_INIT;
828 int ret;
829 strbuf_addf(&buf, "%srefs/", get_git_namespace());
830 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
831 strbuf_release(&buf);
832 return ret;
833 }
834
835 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
836 const char *prefix, void *cb_data)
837 {
838 struct strbuf real_pattern = STRBUF_INIT;
839 struct ref_filter filter;
840 int ret;
841
842 if (!prefix && prefixcmp(pattern, "refs/"))
843 strbuf_addstr(&real_pattern, "refs/");
844 else if (prefix)
845 strbuf_addstr(&real_pattern, prefix);
846 strbuf_addstr(&real_pattern, pattern);
847
848 if (!has_glob_specials(pattern)) {
849 /* Append implied '/' '*' if not present. */
850 if (real_pattern.buf[real_pattern.len - 1] != '/')
851 strbuf_addch(&real_pattern, '/');
852 /* No need to check for '*', there is none. */
853 strbuf_addch(&real_pattern, '*');
854 }
855
856 filter.pattern = real_pattern.buf;
857 filter.fn = fn;
858 filter.cb_data = cb_data;
859 ret = for_each_ref(filter_refs, &filter);
860
861 strbuf_release(&real_pattern);
862 return ret;
863 }
864
865 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
866 {
867 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
868 }
869
870 int for_each_rawref(each_ref_fn fn, void *cb_data)
871 {
872 return do_for_each_ref(NULL, "", fn, 0,
873 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
874 }
875
876 /*
877 * Make sure "ref" is something reasonable to have under ".git/refs/";
878 * We do not like it if:
879 *
880 * - any path component of it begins with ".", or
881 * - it has double dots "..", or
882 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
883 * - it ends with a "/".
884 * - it ends with ".lock"
885 * - it contains a "\" (backslash)
886 */
887
888 /* Return true iff ch is not allowed in reference names. */
889 static inline int bad_ref_char(int ch)
890 {
891 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
892 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
893 return 1;
894 /* 2.13 Pattern Matching Notation */
895 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
896 return 1;
897 return 0;
898 }
899
900 /*
901 * Try to read one refname component from the front of ref. Return
902 * the length of the component found, or -1 if the component is not
903 * legal.
904 */
905 static int check_refname_component(const char *ref, int flags)
906 {
907 const char *cp;
908 char last = '\0';
909
910 for (cp = ref; ; cp++) {
911 char ch = *cp;
912 if (ch == '\0' || ch == '/')
913 break;
914 if (bad_ref_char(ch))
915 return -1; /* Illegal character in refname. */
916 if (last == '.' && ch == '.')
917 return -1; /* Refname contains "..". */
918 if (last == '@' && ch == '{')
919 return -1; /* Refname contains "@{". */
920 last = ch;
921 }
922 if (cp == ref)
923 return -1; /* Component has zero length. */
924 if (ref[0] == '.') {
925 if (!(flags & REFNAME_DOT_COMPONENT))
926 return -1; /* Component starts with '.'. */
927 /*
928 * Even if leading dots are allowed, don't allow "."
929 * as a component (".." is prevented by a rule above).
930 */
931 if (ref[1] == '\0')
932 return -1; /* Component equals ".". */
933 }
934 if (cp - ref >= 5 && !memcmp(cp - 5, ".lock", 5))
935 return -1; /* Refname ends with ".lock". */
936 return cp - ref;
937 }
938
939 int check_refname_format(const char *ref, int flags)
940 {
941 int component_len, component_count = 0;
942
943 while (1) {
944 /* We are at the start of a path component. */
945 component_len = check_refname_component(ref, flags);
946 if (component_len < 0) {
947 if ((flags & REFNAME_REFSPEC_PATTERN) &&
948 ref[0] == '*' &&
949 (ref[1] == '\0' || ref[1] == '/')) {
950 /* Accept one wildcard as a full refname component. */
951 flags &= ~REFNAME_REFSPEC_PATTERN;
952 component_len = 1;
953 } else {
954 return -1;
955 }
956 }
957 component_count++;
958 if (ref[component_len] == '\0')
959 break;
960 /* Skip to next component. */
961 ref += component_len + 1;
962 }
963
964 if (ref[component_len - 1] == '.')
965 return -1; /* Refname ends with '.'. */
966 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
967 return -1; /* Refname has only one component. */
968 return 0;
969 }
970
971 const char *prettify_refname(const char *name)
972 {
973 return name + (
974 !prefixcmp(name, "refs/heads/") ? 11 :
975 !prefixcmp(name, "refs/tags/") ? 10 :
976 !prefixcmp(name, "refs/remotes/") ? 13 :
977 0);
978 }
979
980 const char *ref_rev_parse_rules[] = {
981 "%.*s",
982 "refs/%.*s",
983 "refs/tags/%.*s",
984 "refs/heads/%.*s",
985 "refs/remotes/%.*s",
986 "refs/remotes/%.*s/HEAD",
987 NULL
988 };
989
990 const char *ref_fetch_rules[] = {
991 "%.*s",
992 "refs/%.*s",
993 "refs/heads/%.*s",
994 NULL
995 };
996
997 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
998 {
999 const char **p;
1000 const int abbrev_name_len = strlen(abbrev_name);
1001
1002 for (p = rules; *p; p++) {
1003 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1004 return 1;
1005 }
1006 }
1007
1008 return 0;
1009 }
1010
1011 static struct ref_lock *verify_lock(struct ref_lock *lock,
1012 const unsigned char *old_sha1, int mustexist)
1013 {
1014 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1015 error("Can't verify ref %s", lock->ref_name);
1016 unlock_ref(lock);
1017 return NULL;
1018 }
1019 if (hashcmp(lock->old_sha1, old_sha1)) {
1020 error("Ref %s is at %s but expected %s", lock->ref_name,
1021 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1022 unlock_ref(lock);
1023 return NULL;
1024 }
1025 return lock;
1026 }
1027
1028 static int remove_empty_directories(const char *file)
1029 {
1030 /* we want to create a file but there is a directory there;
1031 * if that is an empty directory (or a directory that contains
1032 * only empty directories), remove them.
1033 */
1034 struct strbuf path;
1035 int result;
1036
1037 strbuf_init(&path, 20);
1038 strbuf_addstr(&path, file);
1039
1040 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1041
1042 strbuf_release(&path);
1043
1044 return result;
1045 }
1046
1047 static int is_refname_available(const char *ref, const char *oldref,
1048 struct ref_list *list, int quiet)
1049 {
1050 int namlen = strlen(ref); /* e.g. 'foo/bar' */
1051 while (list) {
1052 /* list->name could be 'foo' or 'foo/bar/baz' */
1053 if (!oldref || strcmp(oldref, list->name)) {
1054 int len = strlen(list->name);
1055 int cmplen = (namlen < len) ? namlen : len;
1056 const char *lead = (namlen < len) ? list->name : ref;
1057 if (!strncmp(ref, list->name, cmplen) &&
1058 lead[cmplen] == '/') {
1059 if (!quiet)
1060 error("'%s' exists; cannot create '%s'",
1061 list->name, ref);
1062 return 0;
1063 }
1064 }
1065 list = list->next;
1066 }
1067 return 1;
1068 }
1069
1070 /*
1071 * *string and *len will only be substituted, and *string returned (for
1072 * later free()ing) if the string passed in is a magic short-hand form
1073 * to name a branch.
1074 */
1075 static char *substitute_branch_name(const char **string, int *len)
1076 {
1077 struct strbuf buf = STRBUF_INIT;
1078 int ret = interpret_branch_name(*string, &buf);
1079
1080 if (ret == *len) {
1081 size_t size;
1082 *string = strbuf_detach(&buf, &size);
1083 *len = size;
1084 return (char *)*string;
1085 }
1086
1087 return NULL;
1088 }
1089
1090 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1091 {
1092 char *last_branch = substitute_branch_name(&str, &len);
1093 const char **p, *r;
1094 int refs_found = 0;
1095
1096 *ref = NULL;
1097 for (p = ref_rev_parse_rules; *p; p++) {
1098 char fullref[PATH_MAX];
1099 unsigned char sha1_from_ref[20];
1100 unsigned char *this_result;
1101 int flag;
1102
1103 this_result = refs_found ? sha1_from_ref : sha1;
1104 mksnpath(fullref, sizeof(fullref), *p, len, str);
1105 r = resolve_ref(fullref, this_result, 1, &flag);
1106 if (r) {
1107 if (!refs_found++)
1108 *ref = xstrdup(r);
1109 if (!warn_ambiguous_refs)
1110 break;
1111 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD"))
1112 warning("ignoring dangling symref %s.", fullref);
1113 }
1114 free(last_branch);
1115 return refs_found;
1116 }
1117
1118 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1119 {
1120 char *last_branch = substitute_branch_name(&str, &len);
1121 const char **p;
1122 int logs_found = 0;
1123
1124 *log = NULL;
1125 for (p = ref_rev_parse_rules; *p; p++) {
1126 struct stat st;
1127 unsigned char hash[20];
1128 char path[PATH_MAX];
1129 const char *ref, *it;
1130
1131 mksnpath(path, sizeof(path), *p, len, str);
1132 ref = resolve_ref(path, hash, 1, NULL);
1133 if (!ref)
1134 continue;
1135 if (!stat(git_path("logs/%s", path), &st) &&
1136 S_ISREG(st.st_mode))
1137 it = path;
1138 else if (strcmp(ref, path) &&
1139 !stat(git_path("logs/%s", ref), &st) &&
1140 S_ISREG(st.st_mode))
1141 it = ref;
1142 else
1143 continue;
1144 if (!logs_found++) {
1145 *log = xstrdup(it);
1146 hashcpy(sha1, hash);
1147 }
1148 if (!warn_ambiguous_refs)
1149 break;
1150 }
1151 free(last_branch);
1152 return logs_found;
1153 }
1154
1155 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
1156 {
1157 char *ref_file;
1158 const char *orig_ref = ref;
1159 struct ref_lock *lock;
1160 int last_errno = 0;
1161 int type, lflags;
1162 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1163 int missing = 0;
1164
1165 lock = xcalloc(1, sizeof(struct ref_lock));
1166 lock->lock_fd = -1;
1167
1168 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
1169 if (!ref && errno == EISDIR) {
1170 /* we are trying to lock foo but we used to
1171 * have foo/bar which now does not exist;
1172 * it is normal for the empty directory 'foo'
1173 * to remain.
1174 */
1175 ref_file = git_path("%s", orig_ref);
1176 if (remove_empty_directories(ref_file)) {
1177 last_errno = errno;
1178 error("there are still refs under '%s'", orig_ref);
1179 goto error_return;
1180 }
1181 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
1182 }
1183 if (type_p)
1184 *type_p = type;
1185 if (!ref) {
1186 last_errno = errno;
1187 error("unable to resolve reference %s: %s",
1188 orig_ref, strerror(errno));
1189 goto error_return;
1190 }
1191 missing = is_null_sha1(lock->old_sha1);
1192 /* When the ref did not exist and we are creating it,
1193 * make sure there is no existing ref that is packed
1194 * whose name begins with our refname, nor a ref whose
1195 * name is a proper prefix of our refname.
1196 */
1197 if (missing &&
1198 !is_refname_available(ref, NULL, get_packed_refs(NULL), 0)) {
1199 last_errno = ENOTDIR;
1200 goto error_return;
1201 }
1202
1203 lock->lk = xcalloc(1, sizeof(struct lock_file));
1204
1205 lflags = LOCK_DIE_ON_ERROR;
1206 if (flags & REF_NODEREF) {
1207 ref = orig_ref;
1208 lflags |= LOCK_NODEREF;
1209 }
1210 lock->ref_name = xstrdup(ref);
1211 lock->orig_ref_name = xstrdup(orig_ref);
1212 ref_file = git_path("%s", ref);
1213 if (missing)
1214 lock->force_write = 1;
1215 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1216 lock->force_write = 1;
1217
1218 if (safe_create_leading_directories(ref_file)) {
1219 last_errno = errno;
1220 error("unable to create directory for %s", ref_file);
1221 goto error_return;
1222 }
1223
1224 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
1225 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
1226
1227 error_return:
1228 unlock_ref(lock);
1229 errno = last_errno;
1230 return NULL;
1231 }
1232
1233 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
1234 {
1235 char refpath[PATH_MAX];
1236 if (check_refname_format(ref, 0))
1237 return NULL;
1238 strcpy(refpath, mkpath("refs/%s", ref));
1239 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
1240 }
1241
1242 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
1243 {
1244 if (check_refname_format(ref, REFNAME_ALLOW_ONELEVEL))
1245 return NULL;
1246 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
1247 }
1248
1249 static struct lock_file packlock;
1250
1251 static int repack_without_ref(const char *refname)
1252 {
1253 struct ref_list *list, *packed_ref_list;
1254 int fd;
1255 int found = 0;
1256
1257 packed_ref_list = get_packed_refs(NULL);
1258 for (list = packed_ref_list; list; list = list->next) {
1259 if (!strcmp(refname, list->name)) {
1260 found = 1;
1261 break;
1262 }
1263 }
1264 if (!found)
1265 return 0;
1266 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1267 if (fd < 0) {
1268 unable_to_lock_error(git_path("packed-refs"), errno);
1269 return error("cannot delete '%s' from packed refs", refname);
1270 }
1271
1272 for (list = packed_ref_list; list; list = list->next) {
1273 char line[PATH_MAX + 100];
1274 int len;
1275
1276 if (!strcmp(refname, list->name))
1277 continue;
1278 len = snprintf(line, sizeof(line), "%s %s\n",
1279 sha1_to_hex(list->sha1), list->name);
1280 /* this should not happen but just being defensive */
1281 if (len > sizeof(line))
1282 die("too long a refname '%s'", list->name);
1283 write_or_die(fd, line, len);
1284 }
1285 return commit_lock_file(&packlock);
1286 }
1287
1288 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
1289 {
1290 struct ref_lock *lock;
1291 int err, i = 0, ret = 0, flag = 0;
1292
1293 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
1294 if (!lock)
1295 return 1;
1296 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
1297 /* loose */
1298 const char *path;
1299
1300 if (!(delopt & REF_NODEREF)) {
1301 i = strlen(lock->lk->filename) - 5; /* .lock */
1302 lock->lk->filename[i] = 0;
1303 path = lock->lk->filename;
1304 } else {
1305 path = git_path("%s", refname);
1306 }
1307 err = unlink_or_warn(path);
1308 if (err && errno != ENOENT)
1309 ret = 1;
1310
1311 if (!(delopt & REF_NODEREF))
1312 lock->lk->filename[i] = '.';
1313 }
1314 /* removing the loose one could have resurrected an earlier
1315 * packed one. Also, if it was not loose we need to repack
1316 * without it.
1317 */
1318 ret |= repack_without_ref(refname);
1319
1320 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1321 invalidate_cached_refs();
1322 unlock_ref(lock);
1323 return ret;
1324 }
1325
1326 /*
1327 * People using contrib's git-new-workdir have .git/logs/refs ->
1328 * /some/other/path/.git/logs/refs, and that may live on another device.
1329 *
1330 * IOW, to avoid cross device rename errors, the temporary renamed log must
1331 * live into logs/refs.
1332 */
1333 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1334
1335 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
1336 {
1337 static const char renamed_ref[] = "RENAMED-REF";
1338 unsigned char sha1[20], orig_sha1[20];
1339 int flag = 0, logmoved = 0;
1340 struct ref_lock *lock;
1341 struct stat loginfo;
1342 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
1343 const char *symref = NULL;
1344
1345 if (log && S_ISLNK(loginfo.st_mode))
1346 return error("reflog for %s is a symlink", oldref);
1347
1348 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1349 if (flag & REF_ISSYMREF)
1350 return error("refname %s is a symbolic ref, renaming it is not supported",
1351 oldref);
1352 if (!symref)
1353 return error("refname %s not found", oldref);
1354
1355 if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
1356 return 1;
1357
1358 if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
1359 return 1;
1360
1361 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
1362 if (!lock)
1363 return error("unable to lock %s", renamed_ref);
1364 lock->force_write = 1;
1365 if (write_ref_sha1(lock, orig_sha1, logmsg))
1366 return error("unable to save current sha1 in %s", renamed_ref);
1367
1368 if (log && rename(git_path("logs/%s", oldref), git_path(TMP_RENAMED_LOG)))
1369 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
1370 oldref, strerror(errno));
1371
1372 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
1373 error("unable to delete old %s", oldref);
1374 goto rollback;
1375 }
1376
1377 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
1378 if (errno==EISDIR) {
1379 if (remove_empty_directories(git_path("%s", newref))) {
1380 error("Directory not empty: %s", newref);
1381 goto rollback;
1382 }
1383 } else {
1384 error("unable to delete existing %s", newref);
1385 goto rollback;
1386 }
1387 }
1388
1389 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1390 error("unable to create directory for %s", newref);
1391 goto rollback;
1392 }
1393
1394 retry:
1395 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newref))) {
1396 if (errno==EISDIR || errno==ENOTDIR) {
1397 /*
1398 * rename(a, b) when b is an existing
1399 * directory ought to result in ISDIR, but
1400 * Solaris 5.8 gives ENOTDIR. Sheesh.
1401 */
1402 if (remove_empty_directories(git_path("logs/%s", newref))) {
1403 error("Directory not empty: logs/%s", newref);
1404 goto rollback;
1405 }
1406 goto retry;
1407 } else {
1408 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
1409 newref, strerror(errno));
1410 goto rollback;
1411 }
1412 }
1413 logmoved = log;
1414
1415 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1416 if (!lock) {
1417 error("unable to lock %s for update", newref);
1418 goto rollback;
1419 }
1420 lock->force_write = 1;
1421 hashcpy(lock->old_sha1, orig_sha1);
1422 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1423 error("unable to write current sha1 into %s", newref);
1424 goto rollback;
1425 }
1426
1427 return 0;
1428
1429 rollback:
1430 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1431 if (!lock) {
1432 error("unable to lock %s for rollback", oldref);
1433 goto rollbacklog;
1434 }
1435
1436 lock->force_write = 1;
1437 flag = log_all_ref_updates;
1438 log_all_ref_updates = 0;
1439 if (write_ref_sha1(lock, orig_sha1, NULL))
1440 error("unable to write current sha1 into %s", oldref);
1441 log_all_ref_updates = flag;
1442
1443 rollbacklog:
1444 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1445 error("unable to restore logfile %s from %s: %s",
1446 oldref, newref, strerror(errno));
1447 if (!logmoved && log &&
1448 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldref)))
1449 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
1450 oldref, strerror(errno));
1451
1452 return 1;
1453 }
1454
1455 int close_ref(struct ref_lock *lock)
1456 {
1457 if (close_lock_file(lock->lk))
1458 return -1;
1459 lock->lock_fd = -1;
1460 return 0;
1461 }
1462
1463 int commit_ref(struct ref_lock *lock)
1464 {
1465 if (commit_lock_file(lock->lk))
1466 return -1;
1467 lock->lock_fd = -1;
1468 return 0;
1469 }
1470
1471 void unlock_ref(struct ref_lock *lock)
1472 {
1473 /* Do not free lock->lk -- atexit() still looks at them */
1474 if (lock->lk)
1475 rollback_lock_file(lock->lk);
1476 free(lock->ref_name);
1477 free(lock->orig_ref_name);
1478 free(lock);
1479 }
1480
1481 /*
1482 * copy the reflog message msg to buf, which has been allocated sufficiently
1483 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1484 * because reflog file is one line per entry.
1485 */
1486 static int copy_msg(char *buf, const char *msg)
1487 {
1488 char *cp = buf;
1489 char c;
1490 int wasspace = 1;
1491
1492 *cp++ = '\t';
1493 while ((c = *msg++)) {
1494 if (wasspace && isspace(c))
1495 continue;
1496 wasspace = isspace(c);
1497 if (wasspace)
1498 c = ' ';
1499 *cp++ = c;
1500 }
1501 while (buf < cp && isspace(cp[-1]))
1502 cp--;
1503 *cp++ = '\n';
1504 return cp - buf;
1505 }
1506
1507 int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
1508 {
1509 int logfd, oflags = O_APPEND | O_WRONLY;
1510
1511 git_snpath(logfile, bufsize, "logs/%s", ref_name);
1512 if (log_all_ref_updates &&
1513 (!prefixcmp(ref_name, "refs/heads/") ||
1514 !prefixcmp(ref_name, "refs/remotes/") ||
1515 !prefixcmp(ref_name, "refs/notes/") ||
1516 !strcmp(ref_name, "HEAD"))) {
1517 if (safe_create_leading_directories(logfile) < 0)
1518 return error("unable to create directory for %s",
1519 logfile);
1520 oflags |= O_CREAT;
1521 }
1522
1523 logfd = open(logfile, oflags, 0666);
1524 if (logfd < 0) {
1525 if (!(oflags & O_CREAT) && errno == ENOENT)
1526 return 0;
1527
1528 if ((oflags & O_CREAT) && errno == EISDIR) {
1529 if (remove_empty_directories(logfile)) {
1530 return error("There are still logs under '%s'",
1531 logfile);
1532 }
1533 logfd = open(logfile, oflags, 0666);
1534 }
1535
1536 if (logfd < 0)
1537 return error("Unable to append to %s: %s",
1538 logfile, strerror(errno));
1539 }
1540
1541 adjust_shared_perm(logfile);
1542 close(logfd);
1543 return 0;
1544 }
1545
1546 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1547 const unsigned char *new_sha1, const char *msg)
1548 {
1549 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1550 unsigned maxlen, len;
1551 int msglen;
1552 char log_file[PATH_MAX];
1553 char *logrec;
1554 const char *committer;
1555
1556 if (log_all_ref_updates < 0)
1557 log_all_ref_updates = !is_bare_repository();
1558
1559 result = log_ref_setup(ref_name, log_file, sizeof(log_file));
1560 if (result)
1561 return result;
1562
1563 logfd = open(log_file, oflags);
1564 if (logfd < 0)
1565 return 0;
1566 msglen = msg ? strlen(msg) : 0;
1567 committer = git_committer_info(0);
1568 maxlen = strlen(committer) + msglen + 100;
1569 logrec = xmalloc(maxlen);
1570 len = sprintf(logrec, "%s %s %s\n",
1571 sha1_to_hex(old_sha1),
1572 sha1_to_hex(new_sha1),
1573 committer);
1574 if (msglen)
1575 len += copy_msg(logrec + len - 1, msg) - 1;
1576 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1577 free(logrec);
1578 if (close(logfd) != 0 || written != len)
1579 return error("Unable to append to %s", log_file);
1580 return 0;
1581 }
1582
1583 static int is_branch(const char *refname)
1584 {
1585 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1586 }
1587
1588 int write_ref_sha1(struct ref_lock *lock,
1589 const unsigned char *sha1, const char *logmsg)
1590 {
1591 static char term = '\n';
1592 struct object *o;
1593
1594 if (!lock)
1595 return -1;
1596 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1597 unlock_ref(lock);
1598 return 0;
1599 }
1600 o = parse_object(sha1);
1601 if (!o) {
1602 error("Trying to write ref %s with nonexistent object %s",
1603 lock->ref_name, sha1_to_hex(sha1));
1604 unlock_ref(lock);
1605 return -1;
1606 }
1607 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1608 error("Trying to write non-commit object %s to branch %s",
1609 sha1_to_hex(sha1), lock->ref_name);
1610 unlock_ref(lock);
1611 return -1;
1612 }
1613 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1614 write_in_full(lock->lock_fd, &term, 1) != 1
1615 || close_ref(lock) < 0) {
1616 error("Couldn't write %s", lock->lk->filename);
1617 unlock_ref(lock);
1618 return -1;
1619 }
1620 invalidate_cached_refs();
1621 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1622 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1623 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1624 unlock_ref(lock);
1625 return -1;
1626 }
1627 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1628 /*
1629 * Special hack: If a branch is updated directly and HEAD
1630 * points to it (may happen on the remote side of a push
1631 * for example) then logically the HEAD reflog should be
1632 * updated too.
1633 * A generic solution implies reverse symref information,
1634 * but finding all symrefs pointing to the given branch
1635 * would be rather costly for this rare event (the direct
1636 * update of a branch) to be worth it. So let's cheat and
1637 * check with HEAD only which should cover 99% of all usage
1638 * scenarios (even 100% of the default ones).
1639 */
1640 unsigned char head_sha1[20];
1641 int head_flag;
1642 const char *head_ref;
1643 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1644 if (head_ref && (head_flag & REF_ISSYMREF) &&
1645 !strcmp(head_ref, lock->ref_name))
1646 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1647 }
1648 if (commit_ref(lock)) {
1649 error("Couldn't set %s", lock->ref_name);
1650 unlock_ref(lock);
1651 return -1;
1652 }
1653 unlock_ref(lock);
1654 return 0;
1655 }
1656
1657 int create_symref(const char *ref_target, const char *refs_heads_master,
1658 const char *logmsg)
1659 {
1660 const char *lockpath;
1661 char ref[1000];
1662 int fd, len, written;
1663 char *git_HEAD = git_pathdup("%s", ref_target);
1664 unsigned char old_sha1[20], new_sha1[20];
1665
1666 if (logmsg && read_ref(ref_target, old_sha1))
1667 hashclr(old_sha1);
1668
1669 if (safe_create_leading_directories(git_HEAD) < 0)
1670 return error("unable to create directory for %s", git_HEAD);
1671
1672 #ifndef NO_SYMLINK_HEAD
1673 if (prefer_symlink_refs) {
1674 unlink(git_HEAD);
1675 if (!symlink(refs_heads_master, git_HEAD))
1676 goto done;
1677 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1678 }
1679 #endif
1680
1681 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1682 if (sizeof(ref) <= len) {
1683 error("refname too long: %s", refs_heads_master);
1684 goto error_free_return;
1685 }
1686 lockpath = mkpath("%s.lock", git_HEAD);
1687 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1688 if (fd < 0) {
1689 error("Unable to open %s for writing", lockpath);
1690 goto error_free_return;
1691 }
1692 written = write_in_full(fd, ref, len);
1693 if (close(fd) != 0 || written != len) {
1694 error("Unable to write to %s", lockpath);
1695 goto error_unlink_return;
1696 }
1697 if (rename(lockpath, git_HEAD) < 0) {
1698 error("Unable to create %s", git_HEAD);
1699 goto error_unlink_return;
1700 }
1701 if (adjust_shared_perm(git_HEAD)) {
1702 error("Unable to fix permissions on %s", lockpath);
1703 error_unlink_return:
1704 unlink_or_warn(lockpath);
1705 error_free_return:
1706 free(git_HEAD);
1707 return -1;
1708 }
1709
1710 #ifndef NO_SYMLINK_HEAD
1711 done:
1712 #endif
1713 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1714 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1715
1716 free(git_HEAD);
1717 return 0;
1718 }
1719
1720 static char *ref_msg(const char *line, const char *endp)
1721 {
1722 const char *ep;
1723 line += 82;
1724 ep = memchr(line, '\n', endp - line);
1725 if (!ep)
1726 ep = endp;
1727 return xmemdupz(line, ep - line);
1728 }
1729
1730 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)
1731 {
1732 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1733 char *tz_c;
1734 int logfd, tz, reccnt = 0;
1735 struct stat st;
1736 unsigned long date;
1737 unsigned char logged_sha1[20];
1738 void *log_mapped;
1739 size_t mapsz;
1740
1741 logfile = git_path("logs/%s", ref);
1742 logfd = open(logfile, O_RDONLY, 0);
1743 if (logfd < 0)
1744 die_errno("Unable to read log '%s'", logfile);
1745 fstat(logfd, &st);
1746 if (!st.st_size)
1747 die("Log %s is empty.", logfile);
1748 mapsz = xsize_t(st.st_size);
1749 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1750 logdata = log_mapped;
1751 close(logfd);
1752
1753 lastrec = NULL;
1754 rec = logend = logdata + st.st_size;
1755 while (logdata < rec) {
1756 reccnt++;
1757 if (logdata < rec && *(rec-1) == '\n')
1758 rec--;
1759 lastgt = NULL;
1760 while (logdata < rec && *(rec-1) != '\n') {
1761 rec--;
1762 if (*rec == '>')
1763 lastgt = rec;
1764 }
1765 if (!lastgt)
1766 die("Log %s is corrupt.", logfile);
1767 date = strtoul(lastgt + 1, &tz_c, 10);
1768 if (date <= at_time || cnt == 0) {
1769 tz = strtoul(tz_c, NULL, 10);
1770 if (msg)
1771 *msg = ref_msg(rec, logend);
1772 if (cutoff_time)
1773 *cutoff_time = date;
1774 if (cutoff_tz)
1775 *cutoff_tz = tz;
1776 if (cutoff_cnt)
1777 *cutoff_cnt = reccnt - 1;
1778 if (lastrec) {
1779 if (get_sha1_hex(lastrec, logged_sha1))
1780 die("Log %s is corrupt.", logfile);
1781 if (get_sha1_hex(rec + 41, sha1))
1782 die("Log %s is corrupt.", logfile);
1783 if (hashcmp(logged_sha1, sha1)) {
1784 warning("Log %s has gap after %s.",
1785 logfile, show_date(date, tz, DATE_RFC2822));
1786 }
1787 }
1788 else if (date == at_time) {
1789 if (get_sha1_hex(rec + 41, sha1))
1790 die("Log %s is corrupt.", logfile);
1791 }
1792 else {
1793 if (get_sha1_hex(rec + 41, logged_sha1))
1794 die("Log %s is corrupt.", logfile);
1795 if (hashcmp(logged_sha1, sha1)) {
1796 warning("Log %s unexpectedly ended on %s.",
1797 logfile, show_date(date, tz, DATE_RFC2822));
1798 }
1799 }
1800 munmap(log_mapped, mapsz);
1801 return 0;
1802 }
1803 lastrec = rec;
1804 if (cnt > 0)
1805 cnt--;
1806 }
1807
1808 rec = logdata;
1809 while (rec < logend && *rec != '>' && *rec != '\n')
1810 rec++;
1811 if (rec == logend || *rec == '\n')
1812 die("Log %s is corrupt.", logfile);
1813 date = strtoul(rec + 1, &tz_c, 10);
1814 tz = strtoul(tz_c, NULL, 10);
1815 if (get_sha1_hex(logdata, sha1))
1816 die("Log %s is corrupt.", logfile);
1817 if (is_null_sha1(sha1)) {
1818 if (get_sha1_hex(logdata + 41, sha1))
1819 die("Log %s is corrupt.", logfile);
1820 }
1821 if (msg)
1822 *msg = ref_msg(logdata, logend);
1823 munmap(log_mapped, mapsz);
1824
1825 if (cutoff_time)
1826 *cutoff_time = date;
1827 if (cutoff_tz)
1828 *cutoff_tz = tz;
1829 if (cutoff_cnt)
1830 *cutoff_cnt = reccnt;
1831 return 1;
1832 }
1833
1834 int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
1835 {
1836 const char *logfile;
1837 FILE *logfp;
1838 struct strbuf sb = STRBUF_INIT;
1839 int ret = 0;
1840
1841 logfile = git_path("logs/%s", ref);
1842 logfp = fopen(logfile, "r");
1843 if (!logfp)
1844 return -1;
1845
1846 if (ofs) {
1847 struct stat statbuf;
1848 if (fstat(fileno(logfp), &statbuf) ||
1849 statbuf.st_size < ofs ||
1850 fseek(logfp, -ofs, SEEK_END) ||
1851 strbuf_getwholeline(&sb, logfp, '\n')) {
1852 fclose(logfp);
1853 strbuf_release(&sb);
1854 return -1;
1855 }
1856 }
1857
1858 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
1859 unsigned char osha1[20], nsha1[20];
1860 char *email_end, *message;
1861 unsigned long timestamp;
1862 int tz;
1863
1864 /* old SP new SP name <email> SP time TAB msg LF */
1865 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
1866 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
1867 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
1868 !(email_end = strchr(sb.buf + 82, '>')) ||
1869 email_end[1] != ' ' ||
1870 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1871 !message || message[0] != ' ' ||
1872 (message[1] != '+' && message[1] != '-') ||
1873 !isdigit(message[2]) || !isdigit(message[3]) ||
1874 !isdigit(message[4]) || !isdigit(message[5]))
1875 continue; /* corrupt? */
1876 email_end[1] = '\0';
1877 tz = strtol(message + 1, NULL, 10);
1878 if (message[6] != '\t')
1879 message += 6;
1880 else
1881 message += 7;
1882 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
1883 cb_data);
1884 if (ret)
1885 break;
1886 }
1887 fclose(logfp);
1888 strbuf_release(&sb);
1889 return ret;
1890 }
1891
1892 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1893 {
1894 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1895 }
1896
1897 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1898 {
1899 DIR *dir = opendir(git_path("logs/%s", base));
1900 int retval = 0;
1901
1902 if (dir) {
1903 struct dirent *de;
1904 int baselen = strlen(base);
1905 char *log = xmalloc(baselen + 257);
1906
1907 memcpy(log, base, baselen);
1908 if (baselen && base[baselen-1] != '/')
1909 log[baselen++] = '/';
1910
1911 while ((de = readdir(dir)) != NULL) {
1912 struct stat st;
1913 int namelen;
1914
1915 if (de->d_name[0] == '.')
1916 continue;
1917 namelen = strlen(de->d_name);
1918 if (namelen > 255)
1919 continue;
1920 if (has_extension(de->d_name, ".lock"))
1921 continue;
1922 memcpy(log + baselen, de->d_name, namelen+1);
1923 if (stat(git_path("logs/%s", log), &st) < 0)
1924 continue;
1925 if (S_ISDIR(st.st_mode)) {
1926 retval = do_for_each_reflog(log, fn, cb_data);
1927 } else {
1928 unsigned char sha1[20];
1929 if (!resolve_ref(log, sha1, 0, NULL))
1930 retval = error("bad ref for %s", log);
1931 else
1932 retval = fn(log, sha1, 0, cb_data);
1933 }
1934 if (retval)
1935 break;
1936 }
1937 free(log);
1938 closedir(dir);
1939 }
1940 else if (*base)
1941 return errno;
1942 return retval;
1943 }
1944
1945 int for_each_reflog(each_ref_fn fn, void *cb_data)
1946 {
1947 return do_for_each_reflog("", fn, cb_data);
1948 }
1949
1950 int update_ref(const char *action, const char *refname,
1951 const unsigned char *sha1, const unsigned char *oldval,
1952 int flags, enum action_on_err onerr)
1953 {
1954 static struct ref_lock *lock;
1955 lock = lock_any_ref_for_update(refname, oldval, flags);
1956 if (!lock) {
1957 const char *str = "Cannot lock the ref '%s'.";
1958 switch (onerr) {
1959 case MSG_ON_ERR: error(str, refname); break;
1960 case DIE_ON_ERR: die(str, refname); break;
1961 case QUIET_ON_ERR: break;
1962 }
1963 return 1;
1964 }
1965 if (write_ref_sha1(lock, sha1, action) < 0) {
1966 const char *str = "Cannot update the ref '%s'.";
1967 switch (onerr) {
1968 case MSG_ON_ERR: error(str, refname); break;
1969 case DIE_ON_ERR: die(str, refname); break;
1970 case QUIET_ON_ERR: break;
1971 }
1972 return 1;
1973 }
1974 return 0;
1975 }
1976
1977 int ref_exists(char *refname)
1978 {
1979 unsigned char sha1[20];
1980 return !!resolve_ref(refname, sha1, 1, NULL);
1981 }
1982
1983 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1984 {
1985 for ( ; list; list = list->next)
1986 if (!strcmp(list->name, name))
1987 return (struct ref *)list;
1988 return NULL;
1989 }
1990
1991 /*
1992 * generate a format suitable for scanf from a ref_rev_parse_rules
1993 * rule, that is replace the "%.*s" spec with a "%s" spec
1994 */
1995 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1996 {
1997 char *spec;
1998
1999 spec = strstr(rule, "%.*s");
2000 if (!spec || strstr(spec + 4, "%.*s"))
2001 die("invalid rule in ref_rev_parse_rules: %s", rule);
2002
2003 /* copy all until spec */
2004 strncpy(scanf_fmt, rule, spec - rule);
2005 scanf_fmt[spec - rule] = '\0';
2006 /* copy new spec */
2007 strcat(scanf_fmt, "%s");
2008 /* copy remaining rule */
2009 strcat(scanf_fmt, spec + 4);
2010
2011 return;
2012 }
2013
2014 char *shorten_unambiguous_ref(const char *ref, int strict)
2015 {
2016 int i;
2017 static char **scanf_fmts;
2018 static int nr_rules;
2019 char *short_name;
2020
2021 /* pre generate scanf formats from ref_rev_parse_rules[] */
2022 if (!nr_rules) {
2023 size_t total_len = 0;
2024
2025 /* the rule list is NULL terminated, count them first */
2026 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2027 /* no +1 because strlen("%s") < strlen("%.*s") */
2028 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2029
2030 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2031
2032 total_len = 0;
2033 for (i = 0; i < nr_rules; i++) {
2034 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2035 + total_len;
2036 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2037 total_len += strlen(ref_rev_parse_rules[i]);
2038 }
2039 }
2040
2041 /* bail out if there are no rules */
2042 if (!nr_rules)
2043 return xstrdup(ref);
2044
2045 /* buffer for scanf result, at most ref must fit */
2046 short_name = xstrdup(ref);
2047
2048 /* skip first rule, it will always match */
2049 for (i = nr_rules - 1; i > 0 ; --i) {
2050 int j;
2051 int rules_to_fail = i;
2052 int short_name_len;
2053
2054 if (1 != sscanf(ref, scanf_fmts[i], short_name))
2055 continue;
2056
2057 short_name_len = strlen(short_name);
2058
2059 /*
2060 * in strict mode, all (except the matched one) rules
2061 * must fail to resolve to a valid non-ambiguous ref
2062 */
2063 if (strict)
2064 rules_to_fail = nr_rules;
2065
2066 /*
2067 * check if the short name resolves to a valid ref,
2068 * but use only rules prior to the matched one
2069 */
2070 for (j = 0; j < rules_to_fail; j++) {
2071 const char *rule = ref_rev_parse_rules[j];
2072 unsigned char short_objectname[20];
2073 char refname[PATH_MAX];
2074
2075 /* skip matched rule */
2076 if (i == j)
2077 continue;
2078
2079 /*
2080 * the short name is ambiguous, if it resolves
2081 * (with this previous rule) to a valid ref
2082 * read_ref() returns 0 on success
2083 */
2084 mksnpath(refname, sizeof(refname),
2085 rule, short_name_len, short_name);
2086 if (!read_ref(refname, short_objectname))
2087 break;
2088 }
2089
2090 /*
2091 * short name is non-ambiguous if all previous rules
2092 * haven't resolved to a valid ref
2093 */
2094 if (j == rules_to_fail)
2095 return short_name;
2096 }
2097
2098 free(short_name);
2099 return xstrdup(ref);
2100 }