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