teach warn_dangling_symref to take a FILE argument
[git/git.git] / refs.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6
7 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8 #define REF_KNOWS_PEELED 04
9
10 struct ref_list {
11 struct ref_list *next;
12 unsigned char flag; /* ISSYMREF? ISPACKED? */
13 unsigned char sha1[20];
14 unsigned char peeled[20];
15 char name[FLEX_ARRAY];
16 };
17
18 static const char *parse_ref_line(char *line, unsigned char *sha1)
19 {
20 /*
21 * 42: the answer to everything.
22 *
23 * In this case, it happens to be the answer to
24 * 40 (length of sha1 hex representation)
25 * +1 (space in between hex and name)
26 * +1 (newline at the end of the line)
27 */
28 int len = strlen(line) - 42;
29
30 if (len <= 0)
31 return NULL;
32 if (get_sha1_hex(line, sha1) < 0)
33 return NULL;
34 if (!isspace(line[40]))
35 return NULL;
36 line += 41;
37 if (isspace(*line))
38 return NULL;
39 if (line[len] != '\n')
40 return NULL;
41 line[len] = 0;
42
43 return line;
44 }
45
46 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
47 int flag, struct ref_list *list,
48 struct ref_list **new_entry)
49 {
50 int len;
51 struct ref_list *entry;
52
53 /* Allocate it and add it in.. */
54 len = strlen(name) + 1;
55 entry = xmalloc(sizeof(struct ref_list) + len);
56 hashcpy(entry->sha1, sha1);
57 hashclr(entry->peeled);
58 memcpy(entry->name, name, len);
59 entry->flag = flag;
60 entry->next = list;
61 if (new_entry)
62 *new_entry = entry;
63 return entry;
64 }
65
66 /* merge sort the ref list */
67 static struct ref_list *sort_ref_list(struct ref_list *list)
68 {
69 int psize, qsize, last_merge_count, cmp;
70 struct ref_list *p, *q, *l, *e;
71 struct ref_list *new_list = list;
72 int k = 1;
73 int merge_count = 0;
74
75 if (!list)
76 return list;
77
78 do {
79 last_merge_count = merge_count;
80 merge_count = 0;
81
82 psize = 0;
83
84 p = new_list;
85 q = new_list;
86 new_list = NULL;
87 l = NULL;
88
89 while (p) {
90 merge_count++;
91
92 while (psize < k && q->next) {
93 q = q->next;
94 psize++;
95 }
96 qsize = k;
97
98 while ((psize > 0) || (qsize > 0 && q)) {
99 if (qsize == 0 || !q) {
100 e = p;
101 p = p->next;
102 psize--;
103 } else if (psize == 0) {
104 e = q;
105 q = q->next;
106 qsize--;
107 } else {
108 cmp = strcmp(q->name, p->name);
109 if (cmp < 0) {
110 e = q;
111 q = q->next;
112 qsize--;
113 } else if (cmp > 0) {
114 e = p;
115 p = p->next;
116 psize--;
117 } else {
118 if (hashcmp(q->sha1, p->sha1))
119 die("Duplicated ref, and SHA1s don't match: %s",
120 q->name);
121 warning("Duplicated ref: %s", q->name);
122 e = q;
123 q = q->next;
124 qsize--;
125 free(e);
126 e = p;
127 p = p->next;
128 psize--;
129 }
130 }
131
132 e->next = NULL;
133
134 if (l)
135 l->next = e;
136 if (!new_list)
137 new_list = e;
138 l = e;
139 }
140
141 p = q;
142 };
143
144 k = k * 2;
145 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
146
147 return new_list;
148 }
149
150 /*
151 * Future: need to be in "struct repository"
152 * when doing a full libification.
153 */
154 static struct cached_refs {
155 char did_loose;
156 char did_packed;
157 struct ref_list *loose;
158 struct ref_list *packed;
159 } cached_refs;
160 static struct ref_list *current_ref;
161
162 static struct ref_list *extra_refs;
163
164 static void free_ref_list(struct ref_list *list)
165 {
166 struct ref_list *next;
167 for ( ; list; list = next) {
168 next = list->next;
169 free(list);
170 }
171 }
172
173 static void invalidate_cached_refs(void)
174 {
175 struct cached_refs *ca = &cached_refs;
176
177 if (ca->did_loose && ca->loose)
178 free_ref_list(ca->loose);
179 if (ca->did_packed && ca->packed)
180 free_ref_list(ca->packed);
181 ca->loose = ca->packed = NULL;
182 ca->did_loose = ca->did_packed = 0;
183 }
184
185 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
186 {
187 struct ref_list *list = NULL;
188 struct ref_list *last = NULL;
189 char refline[PATH_MAX];
190 int flag = REF_ISPACKED;
191
192 while (fgets(refline, sizeof(refline), f)) {
193 unsigned char sha1[20];
194 const char *name;
195 static const char header[] = "# pack-refs with:";
196
197 if (!strncmp(refline, header, sizeof(header)-1)) {
198 const char *traits = refline + sizeof(header) - 1;
199 if (strstr(traits, " peeled "))
200 flag |= REF_KNOWS_PEELED;
201 /* perhaps other traits later as well */
202 continue;
203 }
204
205 name = parse_ref_line(refline, sha1);
206 if (name) {
207 list = add_ref(name, sha1, flag, list, &last);
208 continue;
209 }
210 if (last &&
211 refline[0] == '^' &&
212 strlen(refline) == 42 &&
213 refline[41] == '\n' &&
214 !get_sha1_hex(refline + 1, sha1))
215 hashcpy(last->peeled, sha1);
216 }
217 cached_refs->packed = sort_ref_list(list);
218 }
219
220 void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
221 {
222 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
223 }
224
225 void clear_extra_refs(void)
226 {
227 free_ref_list(extra_refs);
228 extra_refs = NULL;
229 }
230
231 static struct ref_list *get_packed_refs(void)
232 {
233 if (!cached_refs.did_packed) {
234 FILE *f = fopen(git_path("packed-refs"), "r");
235 cached_refs.packed = NULL;
236 if (f) {
237 read_packed_refs(f, &cached_refs);
238 fclose(f);
239 }
240 cached_refs.did_packed = 1;
241 }
242 return cached_refs.packed;
243 }
244
245 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
246 {
247 DIR *dir = opendir(git_path("%s", base));
248
249 if (dir) {
250 struct dirent *de;
251 int baselen = strlen(base);
252 char *ref = xmalloc(baselen + 257);
253
254 memcpy(ref, base, baselen);
255 if (baselen && base[baselen-1] != '/')
256 ref[baselen++] = '/';
257
258 while ((de = readdir(dir)) != NULL) {
259 unsigned char sha1[20];
260 struct stat st;
261 int flag;
262 int namelen;
263
264 if (de->d_name[0] == '.')
265 continue;
266 namelen = strlen(de->d_name);
267 if (namelen > 255)
268 continue;
269 if (has_extension(de->d_name, ".lock"))
270 continue;
271 memcpy(ref + baselen, de->d_name, namelen+1);
272 if (stat(git_path("%s", ref), &st) < 0)
273 continue;
274 if (S_ISDIR(st.st_mode)) {
275 list = get_ref_dir(ref, list);
276 continue;
277 }
278 if (!resolve_ref(ref, sha1, 1, &flag))
279 hashclr(sha1);
280 list = add_ref(ref, sha1, flag, list, NULL);
281 }
282 free(ref);
283 closedir(dir);
284 }
285 return sort_ref_list(list);
286 }
287
288 struct warn_if_dangling_data {
289 FILE *fp;
290 const char *refname;
291 const char *msg_fmt;
292 };
293
294 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
295 int flags, void *cb_data)
296 {
297 struct warn_if_dangling_data *d = cb_data;
298 const char *resolves_to;
299 unsigned char junk[20];
300
301 if (!(flags & REF_ISSYMREF))
302 return 0;
303
304 resolves_to = resolve_ref(refname, junk, 0, NULL);
305 if (!resolves_to || strcmp(resolves_to, d->refname))
306 return 0;
307
308 fprintf(d->fp, d->msg_fmt, refname);
309 return 0;
310 }
311
312 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
313 {
314 struct warn_if_dangling_data data = { fp, refname, msg_fmt };
315 for_each_rawref(warn_if_dangling_symref, &data);
316 }
317
318 static struct ref_list *get_loose_refs(void)
319 {
320 if (!cached_refs.did_loose) {
321 cached_refs.loose = get_ref_dir("refs", NULL);
322 cached_refs.did_loose = 1;
323 }
324 return cached_refs.loose;
325 }
326
327 /* We allow "recursive" symbolic refs. Only within reason, though */
328 #define MAXDEPTH 5
329 #define MAXREFLEN (1024)
330
331 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
332 {
333 FILE *f;
334 struct cached_refs refs;
335 struct ref_list *ref;
336 int retval;
337
338 strcpy(name + pathlen, "packed-refs");
339 f = fopen(name, "r");
340 if (!f)
341 return -1;
342 read_packed_refs(f, &refs);
343 fclose(f);
344 ref = refs.packed;
345 retval = -1;
346 while (ref) {
347 if (!strcmp(ref->name, refname)) {
348 retval = 0;
349 memcpy(result, ref->sha1, 20);
350 break;
351 }
352 ref = ref->next;
353 }
354 free_ref_list(refs.packed);
355 return retval;
356 }
357
358 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
359 {
360 int fd, len = strlen(refname);
361 char buffer[128], *p;
362
363 if (recursion > MAXDEPTH || len > MAXREFLEN)
364 return -1;
365 memcpy(name + pathlen, refname, len+1);
366 fd = open(name, O_RDONLY);
367 if (fd < 0)
368 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
369
370 len = read(fd, buffer, sizeof(buffer)-1);
371 close(fd);
372 if (len < 0)
373 return -1;
374 while (len && isspace(buffer[len-1]))
375 len--;
376 buffer[len] = 0;
377
378 /* Was it a detached head or an old-fashioned symlink? */
379 if (!get_sha1_hex(buffer, result))
380 return 0;
381
382 /* Symref? */
383 if (strncmp(buffer, "ref:", 4))
384 return -1;
385 p = buffer + 4;
386 while (isspace(*p))
387 p++;
388
389 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
390 }
391
392 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
393 {
394 int len = strlen(path), retval;
395 char *gitdir;
396 const char *tmp;
397
398 while (len && path[len-1] == '/')
399 len--;
400 if (!len)
401 return -1;
402 gitdir = xmalloc(len + MAXREFLEN + 8);
403 memcpy(gitdir, path, len);
404 memcpy(gitdir + len, "/.git", 6);
405 len += 5;
406
407 tmp = read_gitfile_gently(gitdir);
408 if (tmp) {
409 free(gitdir);
410 len = strlen(tmp);
411 gitdir = xmalloc(len + MAXREFLEN + 3);
412 memcpy(gitdir, tmp, len);
413 }
414 gitdir[len] = '/';
415 gitdir[++len] = '\0';
416 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
417 free(gitdir);
418 return retval;
419 }
420
421 /*
422 * If the "reading" argument is set, this function finds out what _object_
423 * the ref points at by "reading" the ref. The ref, if it is not symbolic,
424 * has to exist, and if it is symbolic, it has to point at an existing ref,
425 * because the "read" goes through the symref to the ref it points at.
426 *
427 * The access that is not "reading" may often be "writing", but does not
428 * have to; it can be merely checking _where it leads to_. If it is a
429 * prelude to "writing" to the ref, a write to a symref that points at
430 * yet-to-be-born ref will create the real ref pointed by the symref.
431 * reading=0 allows the caller to check where such a symref leads to.
432 */
433 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
434 {
435 int depth = MAXDEPTH;
436 ssize_t len;
437 char buffer[256];
438 static char ref_buffer[256];
439
440 if (flag)
441 *flag = 0;
442
443 for (;;) {
444 char path[PATH_MAX];
445 struct stat st;
446 char *buf;
447 int fd;
448
449 if (--depth < 0)
450 return NULL;
451
452 git_snpath(path, sizeof(path), "%s", ref);
453 /* Special case: non-existing file. */
454 if (lstat(path, &st) < 0) {
455 struct ref_list *list = get_packed_refs();
456 while (list) {
457 if (!strcmp(ref, list->name)) {
458 hashcpy(sha1, list->sha1);
459 if (flag)
460 *flag |= REF_ISPACKED;
461 return ref;
462 }
463 list = list->next;
464 }
465 if (reading || errno != ENOENT)
466 return NULL;
467 hashclr(sha1);
468 return ref;
469 }
470
471 /* Follow "normalized" - ie "refs/.." symlinks by hand */
472 if (S_ISLNK(st.st_mode)) {
473 len = readlink(path, buffer, sizeof(buffer)-1);
474 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
475 buffer[len] = 0;
476 strcpy(ref_buffer, buffer);
477 ref = ref_buffer;
478 if (flag)
479 *flag |= REF_ISSYMREF;
480 continue;
481 }
482 }
483
484 /* Is it a directory? */
485 if (S_ISDIR(st.st_mode)) {
486 errno = EISDIR;
487 return NULL;
488 }
489
490 /*
491 * Anything else, just open it and try to use it as
492 * a ref
493 */
494 fd = open(path, O_RDONLY);
495 if (fd < 0)
496 return NULL;
497 len = read_in_full(fd, buffer, sizeof(buffer)-1);
498 close(fd);
499
500 /*
501 * Is it a symbolic ref?
502 */
503 if (len < 4 || memcmp("ref:", buffer, 4))
504 break;
505 buf = buffer + 4;
506 len -= 4;
507 while (len && isspace(*buf))
508 buf++, len--;
509 while (len && isspace(buf[len-1]))
510 len--;
511 buf[len] = 0;
512 memcpy(ref_buffer, buf, len + 1);
513 ref = ref_buffer;
514 if (flag)
515 *flag |= REF_ISSYMREF;
516 }
517 if (len < 40 || get_sha1_hex(buffer, sha1))
518 return NULL;
519 return ref;
520 }
521
522 int read_ref(const char *ref, unsigned char *sha1)
523 {
524 if (resolve_ref(ref, sha1, 1, NULL))
525 return 0;
526 return -1;
527 }
528
529 #define DO_FOR_EACH_INCLUDE_BROKEN 01
530 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
531 int flags, void *cb_data, struct ref_list *entry)
532 {
533 if (strncmp(base, entry->name, trim))
534 return 0;
535 /* Is this a "negative ref" that represents a deleted ref? */
536 if (is_null_sha1(entry->sha1))
537 return 0;
538 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
539 if (!has_sha1_file(entry->sha1)) {
540 error("%s does not point to a valid object!", entry->name);
541 return 0;
542 }
543 }
544 current_ref = entry;
545 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
546 }
547
548 int peel_ref(const char *ref, unsigned char *sha1)
549 {
550 int flag;
551 unsigned char base[20];
552 struct object *o;
553
554 if (current_ref && (current_ref->name == ref
555 || !strcmp(current_ref->name, ref))) {
556 if (current_ref->flag & REF_KNOWS_PEELED) {
557 hashcpy(sha1, current_ref->peeled);
558 return 0;
559 }
560 hashcpy(base, current_ref->sha1);
561 goto fallback;
562 }
563
564 if (!resolve_ref(ref, base, 1, &flag))
565 return -1;
566
567 if ((flag & REF_ISPACKED)) {
568 struct ref_list *list = get_packed_refs();
569
570 while (list) {
571 if (!strcmp(list->name, ref)) {
572 if (list->flag & REF_KNOWS_PEELED) {
573 hashcpy(sha1, list->peeled);
574 return 0;
575 }
576 /* older pack-refs did not leave peeled ones */
577 break;
578 }
579 list = list->next;
580 }
581 }
582
583 fallback:
584 o = parse_object(base);
585 if (o && o->type == OBJ_TAG) {
586 o = deref_tag(o, ref, 0);
587 if (o) {
588 hashcpy(sha1, o->sha1);
589 return 0;
590 }
591 }
592 return -1;
593 }
594
595 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
596 int flags, void *cb_data)
597 {
598 int retval = 0;
599 struct ref_list *packed = get_packed_refs();
600 struct ref_list *loose = get_loose_refs();
601
602 struct ref_list *extra;
603
604 for (extra = extra_refs; extra; extra = extra->next)
605 retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
606
607 while (packed && loose) {
608 struct ref_list *entry;
609 int cmp = strcmp(packed->name, loose->name);
610 if (!cmp) {
611 packed = packed->next;
612 continue;
613 }
614 if (cmp > 0) {
615 entry = loose;
616 loose = loose->next;
617 } else {
618 entry = packed;
619 packed = packed->next;
620 }
621 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
622 if (retval)
623 goto end_each;
624 }
625
626 for (packed = packed ? packed : loose; packed; packed = packed->next) {
627 retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
628 if (retval)
629 goto end_each;
630 }
631
632 end_each:
633 current_ref = NULL;
634 return retval;
635 }
636
637 int head_ref(each_ref_fn fn, void *cb_data)
638 {
639 unsigned char sha1[20];
640 int flag;
641
642 if (resolve_ref("HEAD", sha1, 1, &flag))
643 return fn("HEAD", sha1, flag, cb_data);
644 return 0;
645 }
646
647 int for_each_ref(each_ref_fn fn, void *cb_data)
648 {
649 return do_for_each_ref("refs/", fn, 0, 0, cb_data);
650 }
651
652 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
653 {
654 return do_for_each_ref(prefix, fn, strlen(prefix), 0, cb_data);
655 }
656
657 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
658 {
659 return for_each_ref_in("refs/tags/", fn, cb_data);
660 }
661
662 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
663 {
664 return for_each_ref_in("refs/heads/", fn, cb_data);
665 }
666
667 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
668 {
669 return for_each_ref_in("refs/remotes/", fn, cb_data);
670 }
671
672 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
673 {
674 return do_for_each_ref("refs/replace/", fn, 13, 0, cb_data);
675 }
676
677 int for_each_rawref(each_ref_fn fn, void *cb_data)
678 {
679 return do_for_each_ref("refs/", fn, 0,
680 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
681 }
682
683 /*
684 * Make sure "ref" is something reasonable to have under ".git/refs/";
685 * We do not like it if:
686 *
687 * - any path component of it begins with ".", or
688 * - it has double dots "..", or
689 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
690 * - it ends with a "/".
691 * - it ends with ".lock"
692 * - it contains a "\" (backslash)
693 */
694
695 static inline int bad_ref_char(int ch)
696 {
697 if (((unsigned) ch) <= ' ' ||
698 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
699 return 1;
700 /* 2.13 Pattern Matching Notation */
701 if (ch == '?' || ch == '[') /* Unsupported */
702 return 1;
703 if (ch == '*') /* Supported at the end */
704 return 2;
705 return 0;
706 }
707
708 int check_ref_format(const char *ref)
709 {
710 int ch, level, bad_type, last;
711 int ret = CHECK_REF_FORMAT_OK;
712 const char *cp = ref;
713
714 level = 0;
715 while (1) {
716 while ((ch = *cp++) == '/')
717 ; /* tolerate duplicated slashes */
718 if (!ch)
719 /* should not end with slashes */
720 return CHECK_REF_FORMAT_ERROR;
721
722 /* we are at the beginning of the path component */
723 if (ch == '.')
724 return CHECK_REF_FORMAT_ERROR;
725 bad_type = bad_ref_char(ch);
726 if (bad_type) {
727 if (bad_type == 2 && (!*cp || *cp == '/') &&
728 ret == CHECK_REF_FORMAT_OK)
729 ret = CHECK_REF_FORMAT_WILDCARD;
730 else
731 return CHECK_REF_FORMAT_ERROR;
732 }
733
734 last = ch;
735 /* scan the rest of the path component */
736 while ((ch = *cp++) != 0) {
737 bad_type = bad_ref_char(ch);
738 if (bad_type)
739 return CHECK_REF_FORMAT_ERROR;
740 if (ch == '/')
741 break;
742 if (last == '.' && ch == '.')
743 return CHECK_REF_FORMAT_ERROR;
744 if (last == '@' && ch == '{')
745 return CHECK_REF_FORMAT_ERROR;
746 last = ch;
747 }
748 level++;
749 if (!ch) {
750 if (ref <= cp - 2 && cp[-2] == '.')
751 return CHECK_REF_FORMAT_ERROR;
752 if (level < 2)
753 return CHECK_REF_FORMAT_ONELEVEL;
754 if (has_extension(ref, ".lock"))
755 return CHECK_REF_FORMAT_ERROR;
756 return ret;
757 }
758 }
759 }
760
761 const char *prettify_refname(const char *name)
762 {
763 return name + (
764 !prefixcmp(name, "refs/heads/") ? 11 :
765 !prefixcmp(name, "refs/tags/") ? 10 :
766 !prefixcmp(name, "refs/remotes/") ? 13 :
767 0);
768 }
769
770 const char *ref_rev_parse_rules[] = {
771 "%.*s",
772 "refs/%.*s",
773 "refs/tags/%.*s",
774 "refs/heads/%.*s",
775 "refs/remotes/%.*s",
776 "refs/remotes/%.*s/HEAD",
777 NULL
778 };
779
780 const char *ref_fetch_rules[] = {
781 "%.*s",
782 "refs/%.*s",
783 "refs/heads/%.*s",
784 NULL
785 };
786
787 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
788 {
789 const char **p;
790 const int abbrev_name_len = strlen(abbrev_name);
791
792 for (p = rules; *p; p++) {
793 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
794 return 1;
795 }
796 }
797
798 return 0;
799 }
800
801 static struct ref_lock *verify_lock(struct ref_lock *lock,
802 const unsigned char *old_sha1, int mustexist)
803 {
804 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
805 error("Can't verify ref %s", lock->ref_name);
806 unlock_ref(lock);
807 return NULL;
808 }
809 if (hashcmp(lock->old_sha1, old_sha1)) {
810 error("Ref %s is at %s but expected %s", lock->ref_name,
811 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
812 unlock_ref(lock);
813 return NULL;
814 }
815 return lock;
816 }
817
818 static int remove_empty_directories(const char *file)
819 {
820 /* we want to create a file but there is a directory there;
821 * if that is an empty directory (or a directory that contains
822 * only empty directories), remove them.
823 */
824 struct strbuf path;
825 int result;
826
827 strbuf_init(&path, 20);
828 strbuf_addstr(&path, file);
829
830 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
831
832 strbuf_release(&path);
833
834 return result;
835 }
836
837 static int is_refname_available(const char *ref, const char *oldref,
838 struct ref_list *list, int quiet)
839 {
840 int namlen = strlen(ref); /* e.g. 'foo/bar' */
841 while (list) {
842 /* list->name could be 'foo' or 'foo/bar/baz' */
843 if (!oldref || strcmp(oldref, list->name)) {
844 int len = strlen(list->name);
845 int cmplen = (namlen < len) ? namlen : len;
846 const char *lead = (namlen < len) ? list->name : ref;
847 if (!strncmp(ref, list->name, cmplen) &&
848 lead[cmplen] == '/') {
849 if (!quiet)
850 error("'%s' exists; cannot create '%s'",
851 list->name, ref);
852 return 0;
853 }
854 }
855 list = list->next;
856 }
857 return 1;
858 }
859
860 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
861 {
862 char *ref_file;
863 const char *orig_ref = ref;
864 struct ref_lock *lock;
865 int last_errno = 0;
866 int type, lflags;
867 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
868 int missing = 0;
869
870 lock = xcalloc(1, sizeof(struct ref_lock));
871 lock->lock_fd = -1;
872
873 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
874 if (!ref && errno == EISDIR) {
875 /* we are trying to lock foo but we used to
876 * have foo/bar which now does not exist;
877 * it is normal for the empty directory 'foo'
878 * to remain.
879 */
880 ref_file = git_path("%s", orig_ref);
881 if (remove_empty_directories(ref_file)) {
882 last_errno = errno;
883 error("there are still refs under '%s'", orig_ref);
884 goto error_return;
885 }
886 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
887 }
888 if (type_p)
889 *type_p = type;
890 if (!ref) {
891 last_errno = errno;
892 error("unable to resolve reference %s: %s",
893 orig_ref, strerror(errno));
894 goto error_return;
895 }
896 missing = is_null_sha1(lock->old_sha1);
897 /* When the ref did not exist and we are creating it,
898 * make sure there is no existing ref that is packed
899 * whose name begins with our refname, nor a ref whose
900 * name is a proper prefix of our refname.
901 */
902 if (missing &&
903 !is_refname_available(ref, NULL, get_packed_refs(), 0)) {
904 last_errno = ENOTDIR;
905 goto error_return;
906 }
907
908 lock->lk = xcalloc(1, sizeof(struct lock_file));
909
910 lflags = LOCK_DIE_ON_ERROR;
911 if (flags & REF_NODEREF) {
912 ref = orig_ref;
913 lflags |= LOCK_NODEREF;
914 }
915 lock->ref_name = xstrdup(ref);
916 lock->orig_ref_name = xstrdup(orig_ref);
917 ref_file = git_path("%s", ref);
918 if (missing)
919 lock->force_write = 1;
920 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
921 lock->force_write = 1;
922
923 if (safe_create_leading_directories(ref_file)) {
924 last_errno = errno;
925 error("unable to create directory for %s", ref_file);
926 goto error_return;
927 }
928
929 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
930 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
931
932 error_return:
933 unlock_ref(lock);
934 errno = last_errno;
935 return NULL;
936 }
937
938 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
939 {
940 char refpath[PATH_MAX];
941 if (check_ref_format(ref))
942 return NULL;
943 strcpy(refpath, mkpath("refs/%s", ref));
944 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
945 }
946
947 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
948 {
949 switch (check_ref_format(ref)) {
950 default:
951 return NULL;
952 case 0:
953 case CHECK_REF_FORMAT_ONELEVEL:
954 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
955 }
956 }
957
958 static struct lock_file packlock;
959
960 static int repack_without_ref(const char *refname)
961 {
962 struct ref_list *list, *packed_ref_list;
963 int fd;
964 int found = 0;
965
966 packed_ref_list = get_packed_refs();
967 for (list = packed_ref_list; list; list = list->next) {
968 if (!strcmp(refname, list->name)) {
969 found = 1;
970 break;
971 }
972 }
973 if (!found)
974 return 0;
975 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
976 if (fd < 0) {
977 unable_to_lock_error(git_path("packed-refs"), errno);
978 return error("cannot delete '%s' from packed refs", refname);
979 }
980
981 for (list = packed_ref_list; list; list = list->next) {
982 char line[PATH_MAX + 100];
983 int len;
984
985 if (!strcmp(refname, list->name))
986 continue;
987 len = snprintf(line, sizeof(line), "%s %s\n",
988 sha1_to_hex(list->sha1), list->name);
989 /* this should not happen but just being defensive */
990 if (len > sizeof(line))
991 die("too long a refname '%s'", list->name);
992 write_or_die(fd, line, len);
993 }
994 return commit_lock_file(&packlock);
995 }
996
997 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
998 {
999 struct ref_lock *lock;
1000 int err, i = 0, ret = 0, flag = 0;
1001
1002 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
1003 if (!lock)
1004 return 1;
1005 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
1006 /* loose */
1007 const char *path;
1008
1009 if (!(delopt & REF_NODEREF)) {
1010 i = strlen(lock->lk->filename) - 5; /* .lock */
1011 lock->lk->filename[i] = 0;
1012 path = lock->lk->filename;
1013 } else {
1014 path = git_path("%s", refname);
1015 }
1016 err = unlink_or_warn(path);
1017 if (err && errno != ENOENT)
1018 ret = 1;
1019
1020 if (!(delopt & REF_NODEREF))
1021 lock->lk->filename[i] = '.';
1022 }
1023 /* removing the loose one could have resurrected an earlier
1024 * packed one. Also, if it was not loose we need to repack
1025 * without it.
1026 */
1027 ret |= repack_without_ref(refname);
1028
1029 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1030 invalidate_cached_refs();
1031 unlock_ref(lock);
1032 return ret;
1033 }
1034
1035 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
1036 {
1037 static const char renamed_ref[] = "RENAMED-REF";
1038 unsigned char sha1[20], orig_sha1[20];
1039 int flag = 0, logmoved = 0;
1040 struct ref_lock *lock;
1041 struct stat loginfo;
1042 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
1043 const char *symref = NULL;
1044
1045 if (log && S_ISLNK(loginfo.st_mode))
1046 return error("reflog for %s is a symlink", oldref);
1047
1048 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1049 if (flag & REF_ISSYMREF)
1050 return error("refname %s is a symbolic ref, renaming it is not supported",
1051 oldref);
1052 if (!symref)
1053 return error("refname %s not found", oldref);
1054
1055 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
1056 return 1;
1057
1058 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
1059 return 1;
1060
1061 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
1062 if (!lock)
1063 return error("unable to lock %s", renamed_ref);
1064 lock->force_write = 1;
1065 if (write_ref_sha1(lock, orig_sha1, logmsg))
1066 return error("unable to save current sha1 in %s", renamed_ref);
1067
1068 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
1069 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
1070 oldref, strerror(errno));
1071
1072 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
1073 error("unable to delete old %s", oldref);
1074 goto rollback;
1075 }
1076
1077 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
1078 if (errno==EISDIR) {
1079 if (remove_empty_directories(git_path("%s", newref))) {
1080 error("Directory not empty: %s", newref);
1081 goto rollback;
1082 }
1083 } else {
1084 error("unable to delete existing %s", newref);
1085 goto rollback;
1086 }
1087 }
1088
1089 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1090 error("unable to create directory for %s", newref);
1091 goto rollback;
1092 }
1093
1094 retry:
1095 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
1096 if (errno==EISDIR || errno==ENOTDIR) {
1097 /*
1098 * rename(a, b) when b is an existing
1099 * directory ought to result in ISDIR, but
1100 * Solaris 5.8 gives ENOTDIR. Sheesh.
1101 */
1102 if (remove_empty_directories(git_path("logs/%s", newref))) {
1103 error("Directory not empty: logs/%s", newref);
1104 goto rollback;
1105 }
1106 goto retry;
1107 } else {
1108 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
1109 newref, strerror(errno));
1110 goto rollback;
1111 }
1112 }
1113 logmoved = log;
1114
1115 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1116 if (!lock) {
1117 error("unable to lock %s for update", newref);
1118 goto rollback;
1119 }
1120 lock->force_write = 1;
1121 hashcpy(lock->old_sha1, orig_sha1);
1122 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1123 error("unable to write current sha1 into %s", newref);
1124 goto rollback;
1125 }
1126
1127 return 0;
1128
1129 rollback:
1130 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1131 if (!lock) {
1132 error("unable to lock %s for rollback", oldref);
1133 goto rollbacklog;
1134 }
1135
1136 lock->force_write = 1;
1137 flag = log_all_ref_updates;
1138 log_all_ref_updates = 0;
1139 if (write_ref_sha1(lock, orig_sha1, NULL))
1140 error("unable to write current sha1 into %s", oldref);
1141 log_all_ref_updates = flag;
1142
1143 rollbacklog:
1144 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1145 error("unable to restore logfile %s from %s: %s",
1146 oldref, newref, strerror(errno));
1147 if (!logmoved && log &&
1148 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1149 error("unable to restore logfile %s from tmp-renamed-log: %s",
1150 oldref, strerror(errno));
1151
1152 return 1;
1153 }
1154
1155 int close_ref(struct ref_lock *lock)
1156 {
1157 if (close_lock_file(lock->lk))
1158 return -1;
1159 lock->lock_fd = -1;
1160 return 0;
1161 }
1162
1163 int commit_ref(struct ref_lock *lock)
1164 {
1165 if (commit_lock_file(lock->lk))
1166 return -1;
1167 lock->lock_fd = -1;
1168 return 0;
1169 }
1170
1171 void unlock_ref(struct ref_lock *lock)
1172 {
1173 /* Do not free lock->lk -- atexit() still looks at them */
1174 if (lock->lk)
1175 rollback_lock_file(lock->lk);
1176 free(lock->ref_name);
1177 free(lock->orig_ref_name);
1178 free(lock);
1179 }
1180
1181 /*
1182 * copy the reflog message msg to buf, which has been allocated sufficiently
1183 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1184 * because reflog file is one line per entry.
1185 */
1186 static int copy_msg(char *buf, const char *msg)
1187 {
1188 char *cp = buf;
1189 char c;
1190 int wasspace = 1;
1191
1192 *cp++ = '\t';
1193 while ((c = *msg++)) {
1194 if (wasspace && isspace(c))
1195 continue;
1196 wasspace = isspace(c);
1197 if (wasspace)
1198 c = ' ';
1199 *cp++ = c;
1200 }
1201 while (buf < cp && isspace(cp[-1]))
1202 cp--;
1203 *cp++ = '\n';
1204 return cp - buf;
1205 }
1206
1207 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1208 const unsigned char *new_sha1, const char *msg)
1209 {
1210 int logfd, written, oflags = O_APPEND | O_WRONLY;
1211 unsigned maxlen, len;
1212 int msglen;
1213 char log_file[PATH_MAX];
1214 char *logrec;
1215 const char *committer;
1216
1217 if (log_all_ref_updates < 0)
1218 log_all_ref_updates = !is_bare_repository();
1219
1220 git_snpath(log_file, sizeof(log_file), "logs/%s", ref_name);
1221
1222 if (log_all_ref_updates &&
1223 (!prefixcmp(ref_name, "refs/heads/") ||
1224 !prefixcmp(ref_name, "refs/remotes/") ||
1225 !strcmp(ref_name, "HEAD"))) {
1226 if (safe_create_leading_directories(log_file) < 0)
1227 return error("unable to create directory for %s",
1228 log_file);
1229 oflags |= O_CREAT;
1230 }
1231
1232 logfd = open(log_file, oflags, 0666);
1233 if (logfd < 0) {
1234 if (!(oflags & O_CREAT) && errno == ENOENT)
1235 return 0;
1236
1237 if ((oflags & O_CREAT) && errno == EISDIR) {
1238 if (remove_empty_directories(log_file)) {
1239 return error("There are still logs under '%s'",
1240 log_file);
1241 }
1242 logfd = open(log_file, oflags, 0666);
1243 }
1244
1245 if (logfd < 0)
1246 return error("Unable to append to %s: %s",
1247 log_file, strerror(errno));
1248 }
1249
1250 adjust_shared_perm(log_file);
1251
1252 msglen = msg ? strlen(msg) : 0;
1253 committer = git_committer_info(0);
1254 maxlen = strlen(committer) + msglen + 100;
1255 logrec = xmalloc(maxlen);
1256 len = sprintf(logrec, "%s %s %s\n",
1257 sha1_to_hex(old_sha1),
1258 sha1_to_hex(new_sha1),
1259 committer);
1260 if (msglen)
1261 len += copy_msg(logrec + len - 1, msg) - 1;
1262 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1263 free(logrec);
1264 if (close(logfd) != 0 || written != len)
1265 return error("Unable to append to %s", log_file);
1266 return 0;
1267 }
1268
1269 static int is_branch(const char *refname)
1270 {
1271 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1272 }
1273
1274 int write_ref_sha1(struct ref_lock *lock,
1275 const unsigned char *sha1, const char *logmsg)
1276 {
1277 static char term = '\n';
1278 struct object *o;
1279
1280 if (!lock)
1281 return -1;
1282 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1283 unlock_ref(lock);
1284 return 0;
1285 }
1286 o = parse_object(sha1);
1287 if (!o) {
1288 error("Trying to write ref %s with nonexistant object %s",
1289 lock->ref_name, sha1_to_hex(sha1));
1290 unlock_ref(lock);
1291 return -1;
1292 }
1293 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1294 error("Trying to write non-commit object %s to branch %s",
1295 sha1_to_hex(sha1), lock->ref_name);
1296 unlock_ref(lock);
1297 return -1;
1298 }
1299 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1300 write_in_full(lock->lock_fd, &term, 1) != 1
1301 || close_ref(lock) < 0) {
1302 error("Couldn't write %s", lock->lk->filename);
1303 unlock_ref(lock);
1304 return -1;
1305 }
1306 invalidate_cached_refs();
1307 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1308 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1309 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1310 unlock_ref(lock);
1311 return -1;
1312 }
1313 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1314 /*
1315 * Special hack: If a branch is updated directly and HEAD
1316 * points to it (may happen on the remote side of a push
1317 * for example) then logically the HEAD reflog should be
1318 * updated too.
1319 * A generic solution implies reverse symref information,
1320 * but finding all symrefs pointing to the given branch
1321 * would be rather costly for this rare event (the direct
1322 * update of a branch) to be worth it. So let's cheat and
1323 * check with HEAD only which should cover 99% of all usage
1324 * scenarios (even 100% of the default ones).
1325 */
1326 unsigned char head_sha1[20];
1327 int head_flag;
1328 const char *head_ref;
1329 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1330 if (head_ref && (head_flag & REF_ISSYMREF) &&
1331 !strcmp(head_ref, lock->ref_name))
1332 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1333 }
1334 if (commit_ref(lock)) {
1335 error("Couldn't set %s", lock->ref_name);
1336 unlock_ref(lock);
1337 return -1;
1338 }
1339 unlock_ref(lock);
1340 return 0;
1341 }
1342
1343 int create_symref(const char *ref_target, const char *refs_heads_master,
1344 const char *logmsg)
1345 {
1346 const char *lockpath;
1347 char ref[1000];
1348 int fd, len, written;
1349 char *git_HEAD = git_pathdup("%s", ref_target);
1350 unsigned char old_sha1[20], new_sha1[20];
1351
1352 if (logmsg && read_ref(ref_target, old_sha1))
1353 hashclr(old_sha1);
1354
1355 if (safe_create_leading_directories(git_HEAD) < 0)
1356 return error("unable to create directory for %s", git_HEAD);
1357
1358 #ifndef NO_SYMLINK_HEAD
1359 if (prefer_symlink_refs) {
1360 unlink(git_HEAD);
1361 if (!symlink(refs_heads_master, git_HEAD))
1362 goto done;
1363 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1364 }
1365 #endif
1366
1367 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1368 if (sizeof(ref) <= len) {
1369 error("refname too long: %s", refs_heads_master);
1370 goto error_free_return;
1371 }
1372 lockpath = mkpath("%s.lock", git_HEAD);
1373 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1374 if (fd < 0) {
1375 error("Unable to open %s for writing", lockpath);
1376 goto error_free_return;
1377 }
1378 written = write_in_full(fd, ref, len);
1379 if (close(fd) != 0 || written != len) {
1380 error("Unable to write to %s", lockpath);
1381 goto error_unlink_return;
1382 }
1383 if (rename(lockpath, git_HEAD) < 0) {
1384 error("Unable to create %s", git_HEAD);
1385 goto error_unlink_return;
1386 }
1387 if (adjust_shared_perm(git_HEAD)) {
1388 error("Unable to fix permissions on %s", lockpath);
1389 error_unlink_return:
1390 unlink_or_warn(lockpath);
1391 error_free_return:
1392 free(git_HEAD);
1393 return -1;
1394 }
1395
1396 #ifndef NO_SYMLINK_HEAD
1397 done:
1398 #endif
1399 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1400 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1401
1402 free(git_HEAD);
1403 return 0;
1404 }
1405
1406 static char *ref_msg(const char *line, const char *endp)
1407 {
1408 const char *ep;
1409 line += 82;
1410 ep = memchr(line, '\n', endp - line);
1411 if (!ep)
1412 ep = endp;
1413 return xmemdupz(line, ep - line);
1414 }
1415
1416 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)
1417 {
1418 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1419 char *tz_c;
1420 int logfd, tz, reccnt = 0;
1421 struct stat st;
1422 unsigned long date;
1423 unsigned char logged_sha1[20];
1424 void *log_mapped;
1425 size_t mapsz;
1426
1427 logfile = git_path("logs/%s", ref);
1428 logfd = open(logfile, O_RDONLY, 0);
1429 if (logfd < 0)
1430 die_errno("Unable to read log '%s'", logfile);
1431 fstat(logfd, &st);
1432 if (!st.st_size)
1433 die("Log %s is empty.", logfile);
1434 mapsz = xsize_t(st.st_size);
1435 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1436 logdata = log_mapped;
1437 close(logfd);
1438
1439 lastrec = NULL;
1440 rec = logend = logdata + st.st_size;
1441 while (logdata < rec) {
1442 reccnt++;
1443 if (logdata < rec && *(rec-1) == '\n')
1444 rec--;
1445 lastgt = NULL;
1446 while (logdata < rec && *(rec-1) != '\n') {
1447 rec--;
1448 if (*rec == '>')
1449 lastgt = rec;
1450 }
1451 if (!lastgt)
1452 die("Log %s is corrupt.", logfile);
1453 date = strtoul(lastgt + 1, &tz_c, 10);
1454 if (date <= at_time || cnt == 0) {
1455 tz = strtoul(tz_c, NULL, 10);
1456 if (msg)
1457 *msg = ref_msg(rec, logend);
1458 if (cutoff_time)
1459 *cutoff_time = date;
1460 if (cutoff_tz)
1461 *cutoff_tz = tz;
1462 if (cutoff_cnt)
1463 *cutoff_cnt = reccnt - 1;
1464 if (lastrec) {
1465 if (get_sha1_hex(lastrec, logged_sha1))
1466 die("Log %s is corrupt.", logfile);
1467 if (get_sha1_hex(rec + 41, sha1))
1468 die("Log %s is corrupt.", logfile);
1469 if (hashcmp(logged_sha1, sha1)) {
1470 warning("Log %s has gap after %s.",
1471 logfile, show_date(date, tz, DATE_RFC2822));
1472 }
1473 }
1474 else if (date == at_time) {
1475 if (get_sha1_hex(rec + 41, sha1))
1476 die("Log %s is corrupt.", logfile);
1477 }
1478 else {
1479 if (get_sha1_hex(rec + 41, logged_sha1))
1480 die("Log %s is corrupt.", logfile);
1481 if (hashcmp(logged_sha1, sha1)) {
1482 warning("Log %s unexpectedly ended on %s.",
1483 logfile, show_date(date, tz, DATE_RFC2822));
1484 }
1485 }
1486 munmap(log_mapped, mapsz);
1487 return 0;
1488 }
1489 lastrec = rec;
1490 if (cnt > 0)
1491 cnt--;
1492 }
1493
1494 rec = logdata;
1495 while (rec < logend && *rec != '>' && *rec != '\n')
1496 rec++;
1497 if (rec == logend || *rec == '\n')
1498 die("Log %s is corrupt.", logfile);
1499 date = strtoul(rec + 1, &tz_c, 10);
1500 tz = strtoul(tz_c, NULL, 10);
1501 if (get_sha1_hex(logdata, sha1))
1502 die("Log %s is corrupt.", logfile);
1503 if (is_null_sha1(sha1)) {
1504 if (get_sha1_hex(logdata + 41, sha1))
1505 die("Log %s is corrupt.", logfile);
1506 }
1507 if (msg)
1508 *msg = ref_msg(logdata, logend);
1509 munmap(log_mapped, mapsz);
1510
1511 if (cutoff_time)
1512 *cutoff_time = date;
1513 if (cutoff_tz)
1514 *cutoff_tz = tz;
1515 if (cutoff_cnt)
1516 *cutoff_cnt = reccnt;
1517 return 1;
1518 }
1519
1520 int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
1521 {
1522 const char *logfile;
1523 FILE *logfp;
1524 char buf[1024];
1525 int ret = 0;
1526
1527 logfile = git_path("logs/%s", ref);
1528 logfp = fopen(logfile, "r");
1529 if (!logfp)
1530 return -1;
1531
1532 if (ofs) {
1533 struct stat statbuf;
1534 if (fstat(fileno(logfp), &statbuf) ||
1535 statbuf.st_size < ofs ||
1536 fseek(logfp, -ofs, SEEK_END) ||
1537 fgets(buf, sizeof(buf), logfp)) {
1538 fclose(logfp);
1539 return -1;
1540 }
1541 }
1542
1543 while (fgets(buf, sizeof(buf), logfp)) {
1544 unsigned char osha1[20], nsha1[20];
1545 char *email_end, *message;
1546 unsigned long timestamp;
1547 int len, tz;
1548
1549 /* old SP new SP name <email> SP time TAB msg LF */
1550 len = strlen(buf);
1551 if (len < 83 || buf[len-1] != '\n' ||
1552 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1553 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1554 !(email_end = strchr(buf + 82, '>')) ||
1555 email_end[1] != ' ' ||
1556 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1557 !message || message[0] != ' ' ||
1558 (message[1] != '+' && message[1] != '-') ||
1559 !isdigit(message[2]) || !isdigit(message[3]) ||
1560 !isdigit(message[4]) || !isdigit(message[5]))
1561 continue; /* corrupt? */
1562 email_end[1] = '\0';
1563 tz = strtol(message + 1, NULL, 10);
1564 if (message[6] != '\t')
1565 message += 6;
1566 else
1567 message += 7;
1568 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1569 if (ret)
1570 break;
1571 }
1572 fclose(logfp);
1573 return ret;
1574 }
1575
1576 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1577 {
1578 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1579 }
1580
1581 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1582 {
1583 DIR *dir = opendir(git_path("logs/%s", base));
1584 int retval = 0;
1585
1586 if (dir) {
1587 struct dirent *de;
1588 int baselen = strlen(base);
1589 char *log = xmalloc(baselen + 257);
1590
1591 memcpy(log, base, baselen);
1592 if (baselen && base[baselen-1] != '/')
1593 log[baselen++] = '/';
1594
1595 while ((de = readdir(dir)) != NULL) {
1596 struct stat st;
1597 int namelen;
1598
1599 if (de->d_name[0] == '.')
1600 continue;
1601 namelen = strlen(de->d_name);
1602 if (namelen > 255)
1603 continue;
1604 if (has_extension(de->d_name, ".lock"))
1605 continue;
1606 memcpy(log + baselen, de->d_name, namelen+1);
1607 if (stat(git_path("logs/%s", log), &st) < 0)
1608 continue;
1609 if (S_ISDIR(st.st_mode)) {
1610 retval = do_for_each_reflog(log, fn, cb_data);
1611 } else {
1612 unsigned char sha1[20];
1613 if (!resolve_ref(log, sha1, 0, NULL))
1614 retval = error("bad ref for %s", log);
1615 else
1616 retval = fn(log, sha1, 0, cb_data);
1617 }
1618 if (retval)
1619 break;
1620 }
1621 free(log);
1622 closedir(dir);
1623 }
1624 else if (*base)
1625 return errno;
1626 return retval;
1627 }
1628
1629 int for_each_reflog(each_ref_fn fn, void *cb_data)
1630 {
1631 return do_for_each_reflog("", fn, cb_data);
1632 }
1633
1634 int update_ref(const char *action, const char *refname,
1635 const unsigned char *sha1, const unsigned char *oldval,
1636 int flags, enum action_on_err onerr)
1637 {
1638 static struct ref_lock *lock;
1639 lock = lock_any_ref_for_update(refname, oldval, flags);
1640 if (!lock) {
1641 const char *str = "Cannot lock the ref '%s'.";
1642 switch (onerr) {
1643 case MSG_ON_ERR: error(str, refname); break;
1644 case DIE_ON_ERR: die(str, refname); break;
1645 case QUIET_ON_ERR: break;
1646 }
1647 return 1;
1648 }
1649 if (write_ref_sha1(lock, sha1, action) < 0) {
1650 const char *str = "Cannot update the ref '%s'.";
1651 switch (onerr) {
1652 case MSG_ON_ERR: error(str, refname); break;
1653 case DIE_ON_ERR: die(str, refname); break;
1654 case QUIET_ON_ERR: break;
1655 }
1656 return 1;
1657 }
1658 return 0;
1659 }
1660
1661 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1662 {
1663 for ( ; list; list = list->next)
1664 if (!strcmp(list->name, name))
1665 return (struct ref *)list;
1666 return NULL;
1667 }
1668
1669 /*
1670 * generate a format suitable for scanf from a ref_rev_parse_rules
1671 * rule, that is replace the "%.*s" spec with a "%s" spec
1672 */
1673 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1674 {
1675 char *spec;
1676
1677 spec = strstr(rule, "%.*s");
1678 if (!spec || strstr(spec + 4, "%.*s"))
1679 die("invalid rule in ref_rev_parse_rules: %s", rule);
1680
1681 /* copy all until spec */
1682 strncpy(scanf_fmt, rule, spec - rule);
1683 scanf_fmt[spec - rule] = '\0';
1684 /* copy new spec */
1685 strcat(scanf_fmt, "%s");
1686 /* copy remaining rule */
1687 strcat(scanf_fmt, spec + 4);
1688
1689 return;
1690 }
1691
1692 char *shorten_unambiguous_ref(const char *ref, int strict)
1693 {
1694 int i;
1695 static char **scanf_fmts;
1696 static int nr_rules;
1697 char *short_name;
1698
1699 /* pre generate scanf formats from ref_rev_parse_rules[] */
1700 if (!nr_rules) {
1701 size_t total_len = 0;
1702
1703 /* the rule list is NULL terminated, count them first */
1704 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
1705 /* no +1 because strlen("%s") < strlen("%.*s") */
1706 total_len += strlen(ref_rev_parse_rules[nr_rules]);
1707
1708 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
1709
1710 total_len = 0;
1711 for (i = 0; i < nr_rules; i++) {
1712 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
1713 + total_len;
1714 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
1715 total_len += strlen(ref_rev_parse_rules[i]);
1716 }
1717 }
1718
1719 /* bail out if there are no rules */
1720 if (!nr_rules)
1721 return xstrdup(ref);
1722
1723 /* buffer for scanf result, at most ref must fit */
1724 short_name = xstrdup(ref);
1725
1726 /* skip first rule, it will always match */
1727 for (i = nr_rules - 1; i > 0 ; --i) {
1728 int j;
1729 int rules_to_fail = i;
1730 int short_name_len;
1731
1732 if (1 != sscanf(ref, scanf_fmts[i], short_name))
1733 continue;
1734
1735 short_name_len = strlen(short_name);
1736
1737 /*
1738 * in strict mode, all (except the matched one) rules
1739 * must fail to resolve to a valid non-ambiguous ref
1740 */
1741 if (strict)
1742 rules_to_fail = nr_rules;
1743
1744 /*
1745 * check if the short name resolves to a valid ref,
1746 * but use only rules prior to the matched one
1747 */
1748 for (j = 0; j < rules_to_fail; j++) {
1749 const char *rule = ref_rev_parse_rules[j];
1750 unsigned char short_objectname[20];
1751 char refname[PATH_MAX];
1752
1753 /* skip matched rule */
1754 if (i == j)
1755 continue;
1756
1757 /*
1758 * the short name is ambiguous, if it resolves
1759 * (with this previous rule) to a valid ref
1760 * read_ref() returns 0 on success
1761 */
1762 mksnpath(refname, sizeof(refname),
1763 rule, short_name_len, short_name);
1764 if (!read_ref(refname, short_objectname))
1765 break;
1766 }
1767
1768 /*
1769 * short name is non-ambiguous if all previous rules
1770 * haven't resolved to a valid ref
1771 */
1772 if (j == rules_to_fail)
1773 return short_name;
1774 }
1775
1776 free(short_name);
1777 return xstrdup(ref);
1778 }