Merge branch 'sp/maint-plug-traverse-commit-list-leak' into sp/fetch-fix
[git/git.git] / refs.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6
7 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8 #define REF_KNOWS_PEELED 04
9
10 struct ref_list {
11 struct ref_list *next;
12 unsigned char flag; /* ISSYMREF? ISPACKED? */
13 unsigned char sha1[20];
14 unsigned char peeled[20];
15 char name[FLEX_ARRAY];
16 };
17
18 static const char *parse_ref_line(char *line, unsigned char *sha1)
19 {
20 /*
21 * 42: the answer to everything.
22 *
23 * In this case, it happens to be the answer to
24 * 40 (length of sha1 hex representation)
25 * +1 (space in between hex and name)
26 * +1 (newline at the end of the line)
27 */
28 int len = strlen(line) - 42;
29
30 if (len <= 0)
31 return NULL;
32 if (get_sha1_hex(line, sha1) < 0)
33 return NULL;
34 if (!isspace(line[40]))
35 return NULL;
36 line += 41;
37 if (isspace(*line))
38 return NULL;
39 if (line[len] != '\n')
40 return NULL;
41 line[len] = 0;
42
43 return line;
44 }
45
46 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
47 int flag, struct ref_list *list,
48 struct ref_list **new_entry)
49 {
50 int len;
51 struct ref_list *entry;
52
53 /* Allocate it and add it in.. */
54 len = strlen(name) + 1;
55 entry = xmalloc(sizeof(struct ref_list) + len);
56 hashcpy(entry->sha1, sha1);
57 hashclr(entry->peeled);
58 memcpy(entry->name, name, len);
59 entry->flag = flag;
60 entry->next = list;
61 if (new_entry)
62 *new_entry = entry;
63 return entry;
64 }
65
66 /* merge sort the ref list */
67 static struct ref_list *sort_ref_list(struct ref_list *list)
68 {
69 int psize, qsize, last_merge_count, cmp;
70 struct ref_list *p, *q, *l, *e;
71 struct ref_list *new_list = list;
72 int k = 1;
73 int merge_count = 0;
74
75 if (!list)
76 return list;
77
78 do {
79 last_merge_count = merge_count;
80 merge_count = 0;
81
82 psize = 0;
83
84 p = new_list;
85 q = new_list;
86 new_list = NULL;
87 l = NULL;
88
89 while (p) {
90 merge_count++;
91
92 while (psize < k && q->next) {
93 q = q->next;
94 psize++;
95 }
96 qsize = k;
97
98 while ((psize > 0) || (qsize > 0 && q)) {
99 if (qsize == 0 || !q) {
100 e = p;
101 p = p->next;
102 psize--;
103 } else if (psize == 0) {
104 e = q;
105 q = q->next;
106 qsize--;
107 } else {
108 cmp = strcmp(q->name, p->name);
109 if (cmp < 0) {
110 e = q;
111 q = q->next;
112 qsize--;
113 } else if (cmp > 0) {
114 e = p;
115 p = p->next;
116 psize--;
117 } else {
118 if (hashcmp(q->sha1, p->sha1))
119 die("Duplicated ref, and SHA1s don't match: %s",
120 q->name);
121 warning("Duplicated ref: %s", q->name);
122 e = q;
123 q = q->next;
124 qsize--;
125 free(e);
126 e = p;
127 p = p->next;
128 psize--;
129 }
130 }
131
132 e->next = NULL;
133
134 if (l)
135 l->next = e;
136 if (!new_list)
137 new_list = e;
138 l = e;
139 }
140
141 p = q;
142 };
143
144 k = k * 2;
145 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
146
147 return new_list;
148 }
149
150 /*
151 * Future: need to be in "struct repository"
152 * when doing a full libification.
153 */
154 static struct cached_refs {
155 char did_loose;
156 char did_packed;
157 struct ref_list *loose;
158 struct ref_list *packed;
159 } cached_refs;
160
161 static void free_ref_list(struct ref_list *list)
162 {
163 struct ref_list *next;
164 for ( ; list; list = next) {
165 next = list->next;
166 free(list);
167 }
168 }
169
170 static void invalidate_cached_refs(void)
171 {
172 struct cached_refs *ca = &cached_refs;
173
174 if (ca->did_loose && ca->loose)
175 free_ref_list(ca->loose);
176 if (ca->did_packed && ca->packed)
177 free_ref_list(ca->packed);
178 ca->loose = ca->packed = NULL;
179 ca->did_loose = ca->did_packed = 0;
180 }
181
182 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
183 {
184 struct ref_list *list = NULL;
185 struct ref_list *last = NULL;
186 char refline[PATH_MAX];
187 int flag = REF_ISPACKED;
188
189 while (fgets(refline, sizeof(refline), f)) {
190 unsigned char sha1[20];
191 const char *name;
192 static const char header[] = "# pack-refs with:";
193
194 if (!strncmp(refline, header, sizeof(header)-1)) {
195 const char *traits = refline + sizeof(header) - 1;
196 if (strstr(traits, " peeled "))
197 flag |= REF_KNOWS_PEELED;
198 /* perhaps other traits later as well */
199 continue;
200 }
201
202 name = parse_ref_line(refline, sha1);
203 if (name) {
204 list = add_ref(name, sha1, flag, list, &last);
205 continue;
206 }
207 if (last &&
208 refline[0] == '^' &&
209 strlen(refline) == 42 &&
210 refline[41] == '\n' &&
211 !get_sha1_hex(refline + 1, sha1))
212 hashcpy(last->peeled, sha1);
213 }
214 cached_refs->packed = sort_ref_list(list);
215 }
216
217 static struct ref_list *get_packed_refs(void)
218 {
219 if (!cached_refs.did_packed) {
220 FILE *f = fopen(git_path("packed-refs"), "r");
221 cached_refs.packed = NULL;
222 if (f) {
223 read_packed_refs(f, &cached_refs);
224 fclose(f);
225 }
226 cached_refs.did_packed = 1;
227 }
228 return cached_refs.packed;
229 }
230
231 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
232 {
233 DIR *dir = opendir(git_path("%s", base));
234
235 if (dir) {
236 struct dirent *de;
237 int baselen = strlen(base);
238 char *ref = xmalloc(baselen + 257);
239
240 memcpy(ref, base, baselen);
241 if (baselen && base[baselen-1] != '/')
242 ref[baselen++] = '/';
243
244 while ((de = readdir(dir)) != NULL) {
245 unsigned char sha1[20];
246 struct stat st;
247 int flag;
248 int namelen;
249
250 if (de->d_name[0] == '.')
251 continue;
252 namelen = strlen(de->d_name);
253 if (namelen > 255)
254 continue;
255 if (has_extension(de->d_name, ".lock"))
256 continue;
257 memcpy(ref + baselen, de->d_name, namelen+1);
258 if (stat(git_path("%s", ref), &st) < 0)
259 continue;
260 if (S_ISDIR(st.st_mode)) {
261 list = get_ref_dir(ref, list);
262 continue;
263 }
264 if (!resolve_ref(ref, sha1, 1, &flag)) {
265 error("%s points nowhere!", ref);
266 continue;
267 }
268 list = add_ref(ref, sha1, flag, list, NULL);
269 }
270 free(ref);
271 closedir(dir);
272 }
273 return sort_ref_list(list);
274 }
275
276 static struct ref_list *get_loose_refs(void)
277 {
278 if (!cached_refs.did_loose) {
279 cached_refs.loose = get_ref_dir("refs", NULL);
280 cached_refs.did_loose = 1;
281 }
282 return cached_refs.loose;
283 }
284
285 /* We allow "recursive" symbolic refs. Only within reason, though */
286 #define MAXDEPTH 5
287 #define MAXREFLEN (1024)
288
289 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
290 {
291 FILE *f;
292 struct cached_refs refs;
293 struct ref_list *ref;
294 int retval;
295
296 strcpy(name + pathlen, "packed-refs");
297 f = fopen(name, "r");
298 if (!f)
299 return -1;
300 read_packed_refs(f, &refs);
301 fclose(f);
302 ref = refs.packed;
303 retval = -1;
304 while (ref) {
305 if (!strcmp(ref->name, refname)) {
306 retval = 0;
307 memcpy(result, ref->sha1, 20);
308 break;
309 }
310 ref = ref->next;
311 }
312 free_ref_list(refs.packed);
313 return retval;
314 }
315
316 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
317 {
318 int fd, len = strlen(refname);
319 char buffer[128], *p;
320
321 if (recursion > MAXDEPTH || len > MAXREFLEN)
322 return -1;
323 memcpy(name + pathlen, refname, len+1);
324 fd = open(name, O_RDONLY);
325 if (fd < 0)
326 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
327
328 len = read(fd, buffer, sizeof(buffer)-1);
329 close(fd);
330 if (len < 0)
331 return -1;
332 while (len && isspace(buffer[len-1]))
333 len--;
334 buffer[len] = 0;
335
336 /* Was it a detached head or an old-fashioned symlink? */
337 if (!get_sha1_hex(buffer, result))
338 return 0;
339
340 /* Symref? */
341 if (strncmp(buffer, "ref:", 4))
342 return -1;
343 p = buffer + 4;
344 while (isspace(*p))
345 p++;
346
347 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
348 }
349
350 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
351 {
352 int len = strlen(path), retval;
353 char *gitdir;
354
355 while (len && path[len-1] == '/')
356 len--;
357 if (!len)
358 return -1;
359 gitdir = xmalloc(len + MAXREFLEN + 8);
360 memcpy(gitdir, path, len);
361 memcpy(gitdir + len, "/.git/", 7);
362
363 retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
364 free(gitdir);
365 return retval;
366 }
367
368 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
369 {
370 int depth = MAXDEPTH, len;
371 char buffer[256];
372 static char ref_buffer[256];
373
374 if (flag)
375 *flag = 0;
376
377 for (;;) {
378 const char *path = git_path("%s", ref);
379 struct stat st;
380 char *buf;
381 int fd;
382
383 if (--depth < 0)
384 return NULL;
385
386 /* Special case: non-existing file.
387 * Not having the refs/heads/new-branch is OK
388 * if we are writing into it, so is .git/HEAD
389 * that points at refs/heads/master still to be
390 * born. It is NOT OK if we are resolving for
391 * reading.
392 */
393 if (lstat(path, &st) < 0) {
394 struct ref_list *list = get_packed_refs();
395 while (list) {
396 if (!strcmp(ref, list->name)) {
397 hashcpy(sha1, list->sha1);
398 if (flag)
399 *flag |= REF_ISPACKED;
400 return ref;
401 }
402 list = list->next;
403 }
404 if (reading || errno != ENOENT)
405 return NULL;
406 hashclr(sha1);
407 return ref;
408 }
409
410 /* Follow "normalized" - ie "refs/.." symlinks by hand */
411 if (S_ISLNK(st.st_mode)) {
412 len = readlink(path, buffer, sizeof(buffer)-1);
413 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
414 buffer[len] = 0;
415 strcpy(ref_buffer, buffer);
416 ref = ref_buffer;
417 if (flag)
418 *flag |= REF_ISSYMREF;
419 continue;
420 }
421 }
422
423 /* Is it a directory? */
424 if (S_ISDIR(st.st_mode)) {
425 errno = EISDIR;
426 return NULL;
427 }
428
429 /*
430 * Anything else, just open it and try to use it as
431 * a ref
432 */
433 fd = open(path, O_RDONLY);
434 if (fd < 0)
435 return NULL;
436 len = read_in_full(fd, buffer, sizeof(buffer)-1);
437 close(fd);
438
439 /*
440 * Is it a symbolic ref?
441 */
442 if (len < 4 || memcmp("ref:", buffer, 4))
443 break;
444 buf = buffer + 4;
445 len -= 4;
446 while (len && isspace(*buf))
447 buf++, len--;
448 while (len && isspace(buf[len-1]))
449 len--;
450 buf[len] = 0;
451 memcpy(ref_buffer, buf, len + 1);
452 ref = ref_buffer;
453 if (flag)
454 *flag |= REF_ISSYMREF;
455 }
456 if (len < 40 || get_sha1_hex(buffer, sha1))
457 return NULL;
458 return ref;
459 }
460
461 int read_ref(const char *ref, unsigned char *sha1)
462 {
463 if (resolve_ref(ref, sha1, 1, NULL))
464 return 0;
465 return -1;
466 }
467
468 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
469 void *cb_data, struct ref_list *entry)
470 {
471 if (strncmp(base, entry->name, trim))
472 return 0;
473 if (is_null_sha1(entry->sha1))
474 return 0;
475 if (!has_sha1_file(entry->sha1)) {
476 error("%s does not point to a valid object!", entry->name);
477 return 0;
478 }
479 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
480 }
481
482 int peel_ref(const char *ref, unsigned char *sha1)
483 {
484 int flag;
485 unsigned char base[20];
486 struct object *o;
487
488 if (!resolve_ref(ref, base, 1, &flag))
489 return -1;
490
491 if ((flag & REF_ISPACKED)) {
492 struct ref_list *list = get_packed_refs();
493
494 while (list) {
495 if (!strcmp(list->name, ref)) {
496 if (list->flag & REF_KNOWS_PEELED) {
497 hashcpy(sha1, list->peeled);
498 return 0;
499 }
500 /* older pack-refs did not leave peeled ones */
501 break;
502 }
503 list = list->next;
504 }
505 }
506
507 /* fallback - callers should not call this for unpacked refs */
508 o = parse_object(base);
509 if (o->type == OBJ_TAG) {
510 o = deref_tag(o, ref, 0);
511 if (o) {
512 hashcpy(sha1, o->sha1);
513 return 0;
514 }
515 }
516 return -1;
517 }
518
519 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
520 void *cb_data)
521 {
522 int retval;
523 struct ref_list *packed = get_packed_refs();
524 struct ref_list *loose = get_loose_refs();
525
526 while (packed && loose) {
527 struct ref_list *entry;
528 int cmp = strcmp(packed->name, loose->name);
529 if (!cmp) {
530 packed = packed->next;
531 continue;
532 }
533 if (cmp > 0) {
534 entry = loose;
535 loose = loose->next;
536 } else {
537 entry = packed;
538 packed = packed->next;
539 }
540 retval = do_one_ref(base, fn, trim, cb_data, entry);
541 if (retval)
542 return retval;
543 }
544
545 for (packed = packed ? packed : loose; packed; packed = packed->next) {
546 retval = do_one_ref(base, fn, trim, cb_data, packed);
547 if (retval)
548 return retval;
549 }
550 return 0;
551 }
552
553 int head_ref(each_ref_fn fn, void *cb_data)
554 {
555 unsigned char sha1[20];
556 int flag;
557
558 if (resolve_ref("HEAD", sha1, 1, &flag))
559 return fn("HEAD", sha1, flag, cb_data);
560 return 0;
561 }
562
563 int for_each_ref(each_ref_fn fn, void *cb_data)
564 {
565 return do_for_each_ref("refs/", fn, 0, cb_data);
566 }
567
568 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
569 {
570 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
571 }
572
573 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
574 {
575 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
576 }
577
578 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
579 {
580 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
581 }
582
583 /* NEEDSWORK: This is only used by ssh-upload and it should go; the
584 * caller should do resolve_ref or read_ref like everybody else. Or
585 * maybe everybody else should use get_ref_sha1() instead of doing
586 * read_ref().
587 */
588 int get_ref_sha1(const char *ref, unsigned char *sha1)
589 {
590 if (check_ref_format(ref))
591 return -1;
592 return read_ref(mkpath("refs/%s", ref), sha1);
593 }
594
595 /*
596 * Make sure "ref" is something reasonable to have under ".git/refs/";
597 * We do not like it if:
598 *
599 * - any path component of it begins with ".", or
600 * - it has double dots "..", or
601 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
602 * - it ends with a "/".
603 */
604
605 static inline int bad_ref_char(int ch)
606 {
607 if (((unsigned) ch) <= ' ' ||
608 ch == '~' || ch == '^' || ch == ':')
609 return 1;
610 /* 2.13 Pattern Matching Notation */
611 if (ch == '?' || ch == '[') /* Unsupported */
612 return 1;
613 if (ch == '*') /* Supported at the end */
614 return 2;
615 return 0;
616 }
617
618 int check_ref_format(const char *ref)
619 {
620 int ch, level, bad_type;
621 const char *cp = ref;
622
623 level = 0;
624 while (1) {
625 while ((ch = *cp++) == '/')
626 ; /* tolerate duplicated slashes */
627 if (!ch)
628 return -1; /* should not end with slashes */
629
630 /* we are at the beginning of the path component */
631 if (ch == '.')
632 return -1;
633 bad_type = bad_ref_char(ch);
634 if (bad_type) {
635 return (bad_type == 2 && !*cp) ? -3 : -1;
636 }
637
638 /* scan the rest of the path component */
639 while ((ch = *cp++) != 0) {
640 bad_type = bad_ref_char(ch);
641 if (bad_type) {
642 return (bad_type == 2 && !*cp) ? -3 : -1;
643 }
644 if (ch == '/')
645 break;
646 if (ch == '.' && *cp == '.')
647 return -1;
648 }
649 level++;
650 if (!ch) {
651 if (level < 2)
652 return -2; /* at least of form "heads/blah" */
653 return 0;
654 }
655 }
656 }
657
658 static struct ref_lock *verify_lock(struct ref_lock *lock,
659 const unsigned char *old_sha1, int mustexist)
660 {
661 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
662 error("Can't verify ref %s", lock->ref_name);
663 unlock_ref(lock);
664 return NULL;
665 }
666 if (hashcmp(lock->old_sha1, old_sha1)) {
667 error("Ref %s is at %s but expected %s", lock->ref_name,
668 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
669 unlock_ref(lock);
670 return NULL;
671 }
672 return lock;
673 }
674
675 static int remove_empty_directories(const char *file)
676 {
677 /* we want to create a file but there is a directory there;
678 * if that is an empty directory (or a directory that contains
679 * only empty directories), remove them.
680 */
681 struct strbuf path;
682 int result;
683
684 strbuf_init(&path, 20);
685 strbuf_addstr(&path, file);
686
687 result = remove_dir_recursively(&path, 1);
688
689 strbuf_release(&path);
690
691 return result;
692 }
693
694 static int is_refname_available(const char *ref, const char *oldref,
695 struct ref_list *list, int quiet)
696 {
697 int namlen = strlen(ref); /* e.g. 'foo/bar' */
698 while (list) {
699 /* list->name could be 'foo' or 'foo/bar/baz' */
700 if (!oldref || strcmp(oldref, list->name)) {
701 int len = strlen(list->name);
702 int cmplen = (namlen < len) ? namlen : len;
703 const char *lead = (namlen < len) ? list->name : ref;
704 if (!strncmp(ref, list->name, cmplen) &&
705 lead[cmplen] == '/') {
706 if (!quiet)
707 error("'%s' exists; cannot create '%s'",
708 list->name, ref);
709 return 0;
710 }
711 }
712 list = list->next;
713 }
714 return 1;
715 }
716
717 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
718 {
719 char *ref_file;
720 const char *orig_ref = ref;
721 struct ref_lock *lock;
722 struct stat st;
723 int last_errno = 0;
724 int type;
725 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
726
727 lock = xcalloc(1, sizeof(struct ref_lock));
728 lock->lock_fd = -1;
729
730 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
731 if (!ref && errno == EISDIR) {
732 /* we are trying to lock foo but we used to
733 * have foo/bar which now does not exist;
734 * it is normal for the empty directory 'foo'
735 * to remain.
736 */
737 ref_file = git_path("%s", orig_ref);
738 if (remove_empty_directories(ref_file)) {
739 last_errno = errno;
740 error("there are still refs under '%s'", orig_ref);
741 goto error_return;
742 }
743 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
744 }
745 if (type_p)
746 *type_p = type;
747 if (!ref) {
748 last_errno = errno;
749 error("unable to resolve reference %s: %s",
750 orig_ref, strerror(errno));
751 goto error_return;
752 }
753 /* When the ref did not exist and we are creating it,
754 * make sure there is no existing ref that is packed
755 * whose name begins with our refname, nor a ref whose
756 * name is a proper prefix of our refname.
757 */
758 if (is_null_sha1(lock->old_sha1) &&
759 !is_refname_available(ref, NULL, get_packed_refs(), 0))
760 goto error_return;
761
762 lock->lk = xcalloc(1, sizeof(struct lock_file));
763
764 if (flags & REF_NODEREF)
765 ref = orig_ref;
766 lock->ref_name = xstrdup(ref);
767 lock->orig_ref_name = xstrdup(orig_ref);
768 ref_file = git_path("%s", ref);
769 if (lstat(ref_file, &st) && errno == ENOENT)
770 lock->force_write = 1;
771 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
772 lock->force_write = 1;
773
774 if (safe_create_leading_directories(ref_file)) {
775 last_errno = errno;
776 error("unable to create directory for %s", ref_file);
777 goto error_return;
778 }
779 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
780
781 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
782
783 error_return:
784 unlock_ref(lock);
785 errno = last_errno;
786 return NULL;
787 }
788
789 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
790 {
791 char refpath[PATH_MAX];
792 if (check_ref_format(ref))
793 return NULL;
794 strcpy(refpath, mkpath("refs/%s", ref));
795 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
796 }
797
798 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
799 {
800 if (check_ref_format(ref) == -1)
801 return NULL;
802 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
803 }
804
805 static struct lock_file packlock;
806
807 static int repack_without_ref(const char *refname)
808 {
809 struct ref_list *list, *packed_ref_list;
810 int fd;
811 int found = 0;
812
813 packed_ref_list = get_packed_refs();
814 for (list = packed_ref_list; list; list = list->next) {
815 if (!strcmp(refname, list->name)) {
816 found = 1;
817 break;
818 }
819 }
820 if (!found)
821 return 0;
822 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
823 if (fd < 0)
824 return error("cannot delete '%s' from packed refs", refname);
825
826 for (list = packed_ref_list; list; list = list->next) {
827 char line[PATH_MAX + 100];
828 int len;
829
830 if (!strcmp(refname, list->name))
831 continue;
832 len = snprintf(line, sizeof(line), "%s %s\n",
833 sha1_to_hex(list->sha1), list->name);
834 /* this should not happen but just being defensive */
835 if (len > sizeof(line))
836 die("too long a refname '%s'", list->name);
837 write_or_die(fd, line, len);
838 }
839 close(fd);
840 return commit_lock_file(&packlock);
841 }
842
843 int delete_ref(const char *refname, const unsigned char *sha1)
844 {
845 struct ref_lock *lock;
846 int err, i, ret = 0, flag = 0;
847
848 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
849 if (!lock)
850 return 1;
851 if (!(flag & REF_ISPACKED)) {
852 /* loose */
853 i = strlen(lock->lk->filename) - 5; /* .lock */
854 lock->lk->filename[i] = 0;
855 err = unlink(lock->lk->filename);
856 if (err) {
857 ret = 1;
858 error("unlink(%s) failed: %s",
859 lock->lk->filename, strerror(errno));
860 }
861 lock->lk->filename[i] = '.';
862 }
863 /* removing the loose one could have resurrected an earlier
864 * packed one. Also, if it was not loose we need to repack
865 * without it.
866 */
867 ret |= repack_without_ref(refname);
868
869 err = unlink(git_path("logs/%s", lock->ref_name));
870 if (err && errno != ENOENT)
871 fprintf(stderr, "warning: unlink(%s) failed: %s",
872 git_path("logs/%s", lock->ref_name), strerror(errno));
873 invalidate_cached_refs();
874 unlock_ref(lock);
875 return ret;
876 }
877
878 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
879 {
880 static const char renamed_ref[] = "RENAMED-REF";
881 unsigned char sha1[20], orig_sha1[20];
882 int flag = 0, logmoved = 0;
883 struct ref_lock *lock;
884 struct stat loginfo;
885 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
886
887 if (S_ISLNK(loginfo.st_mode))
888 return error("reflog for %s is a symlink", oldref);
889
890 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
891 return error("refname %s not found", oldref);
892
893 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
894 return 1;
895
896 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
897 return 1;
898
899 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
900 if (!lock)
901 return error("unable to lock %s", renamed_ref);
902 lock->force_write = 1;
903 if (write_ref_sha1(lock, orig_sha1, logmsg))
904 return error("unable to save current sha1 in %s", renamed_ref);
905
906 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
907 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
908 oldref, strerror(errno));
909
910 if (delete_ref(oldref, orig_sha1)) {
911 error("unable to delete old %s", oldref);
912 goto rollback;
913 }
914
915 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
916 if (errno==EISDIR) {
917 if (remove_empty_directories(git_path("%s", newref))) {
918 error("Directory not empty: %s", newref);
919 goto rollback;
920 }
921 } else {
922 error("unable to delete existing %s", newref);
923 goto rollback;
924 }
925 }
926
927 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
928 error("unable to create directory for %s", newref);
929 goto rollback;
930 }
931
932 retry:
933 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
934 if (errno==EISDIR || errno==ENOTDIR) {
935 /*
936 * rename(a, b) when b is an existing
937 * directory ought to result in ISDIR, but
938 * Solaris 5.8 gives ENOTDIR. Sheesh.
939 */
940 if (remove_empty_directories(git_path("logs/%s", newref))) {
941 error("Directory not empty: logs/%s", newref);
942 goto rollback;
943 }
944 goto retry;
945 } else {
946 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
947 newref, strerror(errno));
948 goto rollback;
949 }
950 }
951 logmoved = log;
952
953 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
954 if (!lock) {
955 error("unable to lock %s for update", newref);
956 goto rollback;
957 }
958
959 lock->force_write = 1;
960 hashcpy(lock->old_sha1, orig_sha1);
961 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
962 error("unable to write current sha1 into %s", newref);
963 goto rollback;
964 }
965
966 return 0;
967
968 rollback:
969 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
970 if (!lock) {
971 error("unable to lock %s for rollback", oldref);
972 goto rollbacklog;
973 }
974
975 lock->force_write = 1;
976 flag = log_all_ref_updates;
977 log_all_ref_updates = 0;
978 if (write_ref_sha1(lock, orig_sha1, NULL))
979 error("unable to write current sha1 into %s", oldref);
980 log_all_ref_updates = flag;
981
982 rollbacklog:
983 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
984 error("unable to restore logfile %s from %s: %s",
985 oldref, newref, strerror(errno));
986 if (!logmoved && log &&
987 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
988 error("unable to restore logfile %s from tmp-renamed-log: %s",
989 oldref, strerror(errno));
990
991 return 1;
992 }
993
994 void unlock_ref(struct ref_lock *lock)
995 {
996 if (lock->lock_fd >= 0) {
997 close(lock->lock_fd);
998 /* Do not free lock->lk -- atexit() still looks at them */
999 if (lock->lk)
1000 rollback_lock_file(lock->lk);
1001 }
1002 free(lock->ref_name);
1003 free(lock->orig_ref_name);
1004 free(lock);
1005 }
1006
1007 /*
1008 * copy the reflog message msg to buf, which has been allocated sufficiently
1009 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1010 * because reflog file is one line per entry.
1011 */
1012 static int copy_msg(char *buf, const char *msg)
1013 {
1014 char *cp = buf;
1015 char c;
1016 int wasspace = 1;
1017
1018 *cp++ = '\t';
1019 while ((c = *msg++)) {
1020 if (wasspace && isspace(c))
1021 continue;
1022 wasspace = isspace(c);
1023 if (wasspace)
1024 c = ' ';
1025 *cp++ = c;
1026 }
1027 while (buf < cp && isspace(cp[-1]))
1028 cp--;
1029 *cp++ = '\n';
1030 return cp - buf;
1031 }
1032
1033 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1034 const unsigned char *new_sha1, const char *msg)
1035 {
1036 int logfd, written, oflags = O_APPEND | O_WRONLY;
1037 unsigned maxlen, len;
1038 int msglen;
1039 char *log_file, *logrec;
1040 const char *committer;
1041
1042 if (log_all_ref_updates < 0)
1043 log_all_ref_updates = !is_bare_repository();
1044
1045 log_file = git_path("logs/%s", ref_name);
1046
1047 if (log_all_ref_updates &&
1048 (!prefixcmp(ref_name, "refs/heads/") ||
1049 !prefixcmp(ref_name, "refs/remotes/") ||
1050 !strcmp(ref_name, "HEAD"))) {
1051 if (safe_create_leading_directories(log_file) < 0)
1052 return error("unable to create directory for %s",
1053 log_file);
1054 oflags |= O_CREAT;
1055 }
1056
1057 logfd = open(log_file, oflags, 0666);
1058 if (logfd < 0) {
1059 if (!(oflags & O_CREAT) && errno == ENOENT)
1060 return 0;
1061
1062 if ((oflags & O_CREAT) && errno == EISDIR) {
1063 if (remove_empty_directories(log_file)) {
1064 return error("There are still logs under '%s'",
1065 log_file);
1066 }
1067 logfd = open(log_file, oflags, 0666);
1068 }
1069
1070 if (logfd < 0)
1071 return error("Unable to append to %s: %s",
1072 log_file, strerror(errno));
1073 }
1074
1075 adjust_shared_perm(log_file);
1076
1077 msglen = msg ? strlen(msg) : 0;
1078 committer = git_committer_info(-1);
1079 maxlen = strlen(committer) + msglen + 100;
1080 logrec = xmalloc(maxlen);
1081 len = sprintf(logrec, "%s %s %s\n",
1082 sha1_to_hex(old_sha1),
1083 sha1_to_hex(new_sha1),
1084 committer);
1085 if (msglen)
1086 len += copy_msg(logrec + len - 1, msg) - 1;
1087 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1088 free(logrec);
1089 if (close(logfd) != 0 || written != len)
1090 return error("Unable to append to %s", log_file);
1091 return 0;
1092 }
1093
1094 int write_ref_sha1(struct ref_lock *lock,
1095 const unsigned char *sha1, const char *logmsg)
1096 {
1097 static char term = '\n';
1098
1099 if (!lock)
1100 return -1;
1101 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1102 unlock_ref(lock);
1103 return 0;
1104 }
1105 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1106 write_in_full(lock->lock_fd, &term, 1) != 1
1107 || close(lock->lock_fd) < 0) {
1108 error("Couldn't write %s", lock->lk->filename);
1109 unlock_ref(lock);
1110 return -1;
1111 }
1112 invalidate_cached_refs();
1113 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1114 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1115 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1116 unlock_ref(lock);
1117 return -1;
1118 }
1119 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1120 /*
1121 * Special hack: If a branch is updated directly and HEAD
1122 * points to it (may happen on the remote side of a push
1123 * for example) then logically the HEAD reflog should be
1124 * updated too.
1125 * A generic solution implies reverse symref information,
1126 * but finding all symrefs pointing to the given branch
1127 * would be rather costly for this rare event (the direct
1128 * update of a branch) to be worth it. So let's cheat and
1129 * check with HEAD only which should cover 99% of all usage
1130 * scenarios (even 100% of the default ones).
1131 */
1132 unsigned char head_sha1[20];
1133 int head_flag;
1134 const char *head_ref;
1135 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1136 if (head_ref && (head_flag & REF_ISSYMREF) &&
1137 !strcmp(head_ref, lock->ref_name))
1138 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1139 }
1140 if (commit_lock_file(lock->lk)) {
1141 error("Couldn't set %s", lock->ref_name);
1142 unlock_ref(lock);
1143 return -1;
1144 }
1145 lock->lock_fd = -1;
1146 unlock_ref(lock);
1147 return 0;
1148 }
1149
1150 int create_symref(const char *ref_target, const char *refs_heads_master,
1151 const char *logmsg)
1152 {
1153 const char *lockpath;
1154 char ref[1000];
1155 int fd, len, written;
1156 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1157 unsigned char old_sha1[20], new_sha1[20];
1158
1159 if (logmsg && read_ref(ref_target, old_sha1))
1160 hashclr(old_sha1);
1161
1162 if (safe_create_leading_directories(git_HEAD) < 0)
1163 return error("unable to create directory for %s", git_HEAD);
1164
1165 #ifndef NO_SYMLINK_HEAD
1166 if (prefer_symlink_refs) {
1167 unlink(git_HEAD);
1168 if (!symlink(refs_heads_master, git_HEAD))
1169 goto done;
1170 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1171 }
1172 #endif
1173
1174 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1175 if (sizeof(ref) <= len) {
1176 error("refname too long: %s", refs_heads_master);
1177 goto error_free_return;
1178 }
1179 lockpath = mkpath("%s.lock", git_HEAD);
1180 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1181 if (fd < 0) {
1182 error("Unable to open %s for writing", lockpath);
1183 goto error_free_return;
1184 }
1185 written = write_in_full(fd, ref, len);
1186 if (close(fd) != 0 || written != len) {
1187 error("Unable to write to %s", lockpath);
1188 goto error_unlink_return;
1189 }
1190 if (rename(lockpath, git_HEAD) < 0) {
1191 error("Unable to create %s", git_HEAD);
1192 goto error_unlink_return;
1193 }
1194 if (adjust_shared_perm(git_HEAD)) {
1195 error("Unable to fix permissions on %s", lockpath);
1196 error_unlink_return:
1197 unlink(lockpath);
1198 error_free_return:
1199 free(git_HEAD);
1200 return -1;
1201 }
1202
1203 #ifndef NO_SYMLINK_HEAD
1204 done:
1205 #endif
1206 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1207 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1208
1209 free(git_HEAD);
1210 return 0;
1211 }
1212
1213 static char *ref_msg(const char *line, const char *endp)
1214 {
1215 const char *ep;
1216 line += 82;
1217 ep = memchr(line, '\n', endp - line);
1218 if (!ep)
1219 ep = endp;
1220 return xmemdupz(line, ep - line);
1221 }
1222
1223 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)
1224 {
1225 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1226 char *tz_c;
1227 int logfd, tz, reccnt = 0;
1228 struct stat st;
1229 unsigned long date;
1230 unsigned char logged_sha1[20];
1231 void *log_mapped;
1232 size_t mapsz;
1233
1234 logfile = git_path("logs/%s", ref);
1235 logfd = open(logfile, O_RDONLY, 0);
1236 if (logfd < 0)
1237 die("Unable to read log %s: %s", logfile, strerror(errno));
1238 fstat(logfd, &st);
1239 if (!st.st_size)
1240 die("Log %s is empty.", logfile);
1241 mapsz = xsize_t(st.st_size);
1242 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1243 logdata = log_mapped;
1244 close(logfd);
1245
1246 lastrec = NULL;
1247 rec = logend = logdata + st.st_size;
1248 while (logdata < rec) {
1249 reccnt++;
1250 if (logdata < rec && *(rec-1) == '\n')
1251 rec--;
1252 lastgt = NULL;
1253 while (logdata < rec && *(rec-1) != '\n') {
1254 rec--;
1255 if (*rec == '>')
1256 lastgt = rec;
1257 }
1258 if (!lastgt)
1259 die("Log %s is corrupt.", logfile);
1260 date = strtoul(lastgt + 1, &tz_c, 10);
1261 if (date <= at_time || cnt == 0) {
1262 tz = strtoul(tz_c, NULL, 10);
1263 if (msg)
1264 *msg = ref_msg(rec, logend);
1265 if (cutoff_time)
1266 *cutoff_time = date;
1267 if (cutoff_tz)
1268 *cutoff_tz = tz;
1269 if (cutoff_cnt)
1270 *cutoff_cnt = reccnt - 1;
1271 if (lastrec) {
1272 if (get_sha1_hex(lastrec, logged_sha1))
1273 die("Log %s is corrupt.", logfile);
1274 if (get_sha1_hex(rec + 41, sha1))
1275 die("Log %s is corrupt.", logfile);
1276 if (hashcmp(logged_sha1, sha1)) {
1277 fprintf(stderr,
1278 "warning: Log %s has gap after %s.\n",
1279 logfile, show_date(date, tz, DATE_RFC2822));
1280 }
1281 }
1282 else if (date == at_time) {
1283 if (get_sha1_hex(rec + 41, sha1))
1284 die("Log %s is corrupt.", logfile);
1285 }
1286 else {
1287 if (get_sha1_hex(rec + 41, logged_sha1))
1288 die("Log %s is corrupt.", logfile);
1289 if (hashcmp(logged_sha1, sha1)) {
1290 fprintf(stderr,
1291 "warning: Log %s unexpectedly ended on %s.\n",
1292 logfile, show_date(date, tz, DATE_RFC2822));
1293 }
1294 }
1295 munmap(log_mapped, mapsz);
1296 return 0;
1297 }
1298 lastrec = rec;
1299 if (cnt > 0)
1300 cnt--;
1301 }
1302
1303 rec = logdata;
1304 while (rec < logend && *rec != '>' && *rec != '\n')
1305 rec++;
1306 if (rec == logend || *rec == '\n')
1307 die("Log %s is corrupt.", logfile);
1308 date = strtoul(rec + 1, &tz_c, 10);
1309 tz = strtoul(tz_c, NULL, 10);
1310 if (get_sha1_hex(logdata, sha1))
1311 die("Log %s is corrupt.", logfile);
1312 if (msg)
1313 *msg = ref_msg(logdata, logend);
1314 munmap(log_mapped, mapsz);
1315
1316 if (cutoff_time)
1317 *cutoff_time = date;
1318 if (cutoff_tz)
1319 *cutoff_tz = tz;
1320 if (cutoff_cnt)
1321 *cutoff_cnt = reccnt;
1322 return 1;
1323 }
1324
1325 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1326 {
1327 const char *logfile;
1328 FILE *logfp;
1329 char buf[1024];
1330 int ret = 0;
1331
1332 logfile = git_path("logs/%s", ref);
1333 logfp = fopen(logfile, "r");
1334 if (!logfp)
1335 return -1;
1336 while (fgets(buf, sizeof(buf), logfp)) {
1337 unsigned char osha1[20], nsha1[20];
1338 char *email_end, *message;
1339 unsigned long timestamp;
1340 int len, tz;
1341
1342 /* old SP new SP name <email> SP time TAB msg LF */
1343 len = strlen(buf);
1344 if (len < 83 || buf[len-1] != '\n' ||
1345 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1346 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1347 !(email_end = strchr(buf + 82, '>')) ||
1348 email_end[1] != ' ' ||
1349 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1350 !message || message[0] != ' ' ||
1351 (message[1] != '+' && message[1] != '-') ||
1352 !isdigit(message[2]) || !isdigit(message[3]) ||
1353 !isdigit(message[4]) || !isdigit(message[5]))
1354 continue; /* corrupt? */
1355 email_end[1] = '\0';
1356 tz = strtol(message + 1, NULL, 10);
1357 if (message[6] != '\t')
1358 message += 6;
1359 else
1360 message += 7;
1361 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1362 if (ret)
1363 break;
1364 }
1365 fclose(logfp);
1366 return ret;
1367 }
1368
1369 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1370 {
1371 DIR *dir = opendir(git_path("logs/%s", base));
1372 int retval = 0;
1373
1374 if (dir) {
1375 struct dirent *de;
1376 int baselen = strlen(base);
1377 char *log = xmalloc(baselen + 257);
1378
1379 memcpy(log, base, baselen);
1380 if (baselen && base[baselen-1] != '/')
1381 log[baselen++] = '/';
1382
1383 while ((de = readdir(dir)) != NULL) {
1384 struct stat st;
1385 int namelen;
1386
1387 if (de->d_name[0] == '.')
1388 continue;
1389 namelen = strlen(de->d_name);
1390 if (namelen > 255)
1391 continue;
1392 if (has_extension(de->d_name, ".lock"))
1393 continue;
1394 memcpy(log + baselen, de->d_name, namelen+1);
1395 if (stat(git_path("logs/%s", log), &st) < 0)
1396 continue;
1397 if (S_ISDIR(st.st_mode)) {
1398 retval = do_for_each_reflog(log, fn, cb_data);
1399 } else {
1400 unsigned char sha1[20];
1401 if (!resolve_ref(log, sha1, 0, NULL))
1402 retval = error("bad ref for %s", log);
1403 else
1404 retval = fn(log, sha1, 0, cb_data);
1405 }
1406 if (retval)
1407 break;
1408 }
1409 free(log);
1410 closedir(dir);
1411 }
1412 else if (*base)
1413 return errno;
1414 return retval;
1415 }
1416
1417 int for_each_reflog(each_ref_fn fn, void *cb_data)
1418 {
1419 return do_for_each_reflog("", fn, cb_data);
1420 }
1421
1422 int update_ref(const char *action, const char *refname,
1423 const unsigned char *sha1, const unsigned char *oldval,
1424 int flags, enum action_on_err onerr)
1425 {
1426 static struct ref_lock *lock;
1427 lock = lock_any_ref_for_update(refname, oldval, flags);
1428 if (!lock) {
1429 const char *str = "Cannot lock the ref '%s'.";
1430 switch (onerr) {
1431 case MSG_ON_ERR: error(str, refname); break;
1432 case DIE_ON_ERR: die(str, refname); break;
1433 case QUIET_ON_ERR: break;
1434 }
1435 return 1;
1436 }
1437 if (write_ref_sha1(lock, sha1, action) < 0) {
1438 const char *str = "Cannot update the ref '%s'.";
1439 switch (onerr) {
1440 case MSG_ON_ERR: error(str, refname); break;
1441 case DIE_ON_ERR: die(str, refname); break;
1442 case QUIET_ON_ERR: break;
1443 }
1444 return 1;
1445 }
1446 return 0;
1447 }