f5cb297292f5ae577e3d2719f5f78512aae8cf28
[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=0x01, ISPACKED=0x02 and ISBROKEN=0x04 are public interfaces */
8 #define REF_KNOWS_PEELED 0x10
9
10 struct ref_entry {
11 unsigned char flag; /* ISSYMREF? ISPACKED? */
12 unsigned char sha1[20];
13 unsigned char peeled[20];
14 char name[FLEX_ARRAY];
15 };
16
17 struct ref_array {
18 int nr, alloc;
19 struct ref_entry **refs;
20 };
21
22 static const char *parse_ref_line(char *line, unsigned char *sha1)
23 {
24 /*
25 * 42: the answer to everything.
26 *
27 * In this case, it happens to be the answer to
28 * 40 (length of sha1 hex representation)
29 * +1 (space in between hex and name)
30 * +1 (newline at the end of the line)
31 */
32 int len = strlen(line) - 42;
33
34 if (len <= 0)
35 return NULL;
36 if (get_sha1_hex(line, sha1) < 0)
37 return NULL;
38 if (!isspace(line[40]))
39 return NULL;
40 line += 41;
41 if (isspace(*line))
42 return NULL;
43 if (line[len] != '\n')
44 return NULL;
45 line[len] = 0;
46
47 return line;
48 }
49
50 static void add_ref(const char *name, const unsigned char *sha1,
51 int flag, int check_name, struct ref_array *refs,
52 struct ref_entry **new_entry)
53 {
54 int len;
55 struct ref_entry *entry;
56
57 /* Allocate it and add it in.. */
58 len = strlen(name) + 1;
59 entry = xmalloc(sizeof(struct ref_entry) + len);
60 hashcpy(entry->sha1, sha1);
61 hashclr(entry->peeled);
62 if (check_name &&
63 check_refname_format(name, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
64 die("Reference has invalid format: '%s'", name);
65 memcpy(entry->name, name, len);
66 entry->flag = flag;
67 if (new_entry)
68 *new_entry = entry;
69 ALLOC_GROW(refs->refs, refs->nr + 1, refs->alloc);
70 refs->refs[refs->nr++] = entry;
71 }
72
73 static int ref_entry_cmp(const void *a, const void *b)
74 {
75 struct ref_entry *one = *(struct ref_entry **)a;
76 struct ref_entry *two = *(struct ref_entry **)b;
77 return strcmp(one->name, two->name);
78 }
79
80 static void sort_ref_array(struct ref_array *array)
81 {
82 int i = 0, j = 1;
83
84 /* Nothing to sort unless there are at least two entries */
85 if (array->nr < 2)
86 return;
87
88 qsort(array->refs, array->nr, sizeof(*array->refs), ref_entry_cmp);
89
90 /* Remove any duplicates from the ref_array */
91 for (; j < array->nr; j++) {
92 struct ref_entry *a = array->refs[i];
93 struct ref_entry *b = array->refs[j];
94 if (!strcmp(a->name, b->name)) {
95 if (hashcmp(a->sha1, b->sha1))
96 die("Duplicated ref, and SHA1s don't match: %s",
97 a->name);
98 warning("Duplicated ref: %s", a->name);
99 free(b);
100 continue;
101 }
102 i++;
103 array->refs[i] = array->refs[j];
104 }
105 array->nr = i + 1;
106 }
107
108 static struct ref_entry *search_ref_array(struct ref_array *array, const char *name)
109 {
110 struct ref_entry *e, **r;
111 int len;
112
113 if (name == NULL)
114 return NULL;
115
116 if (!array->nr)
117 return NULL;
118
119 len = strlen(name) + 1;
120 e = xmalloc(sizeof(struct ref_entry) + len);
121 memcpy(e->name, name, len);
122
123 r = bsearch(&e, array->refs, array->nr, sizeof(*array->refs), ref_entry_cmp);
124
125 free(e);
126
127 if (r == NULL)
128 return NULL;
129
130 return *r;
131 }
132
133 /*
134 * Future: need to be in "struct repository"
135 * when doing a full libification.
136 */
137 static struct ref_cache {
138 struct ref_cache *next;
139 char did_loose;
140 char did_packed;
141 struct ref_array loose;
142 struct ref_array packed;
143 /* The submodule name, or "" for the main repo. */
144 char name[FLEX_ARRAY];
145 } *ref_cache;
146
147 static struct ref_entry *current_ref;
148
149 static struct ref_array extra_refs;
150
151 static void free_ref_array(struct ref_array *array)
152 {
153 int i;
154 for (i = 0; i < array->nr; i++)
155 free(array->refs[i]);
156 free(array->refs);
157 array->nr = array->alloc = 0;
158 array->refs = NULL;
159 }
160
161 static void clear_packed_ref_cache(struct ref_cache *refs)
162 {
163 if (refs->did_packed)
164 free_ref_array(&refs->packed);
165 refs->did_packed = 0;
166 }
167
168 static void clear_loose_ref_cache(struct ref_cache *refs)
169 {
170 if (refs->did_loose)
171 free_ref_array(&refs->loose);
172 refs->did_loose = 0;
173 }
174
175 static struct ref_cache *create_ref_cache(const char *submodule)
176 {
177 int len;
178 struct ref_cache *refs;
179 if (!submodule)
180 submodule = "";
181 len = strlen(submodule) + 1;
182 refs = xcalloc(1, sizeof(struct ref_cache) + len);
183 memcpy(refs->name, submodule, len);
184 return refs;
185 }
186
187 /*
188 * Return a pointer to a ref_cache for the specified submodule. For
189 * the main repository, use submodule==NULL. The returned structure
190 * will be allocated and initialized but not necessarily populated; it
191 * should not be freed.
192 */
193 static struct ref_cache *get_ref_cache(const char *submodule)
194 {
195 struct ref_cache *refs = ref_cache;
196 if (!submodule)
197 submodule = "";
198 while (refs) {
199 if (!strcmp(submodule, refs->name))
200 return refs;
201 refs = refs->next;
202 }
203
204 refs = create_ref_cache(submodule);
205 refs->next = ref_cache;
206 ref_cache = refs;
207 return refs;
208 }
209
210 void invalidate_ref_cache(const char *submodule)
211 {
212 struct ref_cache *refs = get_ref_cache(submodule);
213 clear_packed_ref_cache(refs);
214 clear_loose_ref_cache(refs);
215 }
216
217 static void read_packed_refs(FILE *f, struct ref_array *array)
218 {
219 struct ref_entry *last = NULL;
220 char refline[PATH_MAX];
221 int flag = REF_ISPACKED;
222
223 while (fgets(refline, sizeof(refline), f)) {
224 unsigned char sha1[20];
225 const char *name;
226 static const char header[] = "# pack-refs with:";
227
228 if (!strncmp(refline, header, sizeof(header)-1)) {
229 const char *traits = refline + sizeof(header) - 1;
230 if (strstr(traits, " peeled "))
231 flag |= REF_KNOWS_PEELED;
232 /* perhaps other traits later as well */
233 continue;
234 }
235
236 name = parse_ref_line(refline, sha1);
237 if (name) {
238 add_ref(name, sha1, flag, 1, array, &last);
239 continue;
240 }
241 if (last &&
242 refline[0] == '^' &&
243 strlen(refline) == 42 &&
244 refline[41] == '\n' &&
245 !get_sha1_hex(refline + 1, sha1))
246 hashcpy(last->peeled, sha1);
247 }
248 sort_ref_array(array);
249 }
250
251 void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
252 {
253 add_ref(name, sha1, flag, 0, &extra_refs, NULL);
254 }
255
256 void clear_extra_refs(void)
257 {
258 free_ref_array(&extra_refs);
259 }
260
261 static struct ref_array *get_packed_refs(const char *submodule)
262 {
263 struct ref_cache *refs = get_ref_cache(submodule);
264
265 if (!refs->did_packed) {
266 const char *packed_refs_file;
267 FILE *f;
268
269 if (submodule)
270 packed_refs_file = git_path_submodule(submodule, "packed-refs");
271 else
272 packed_refs_file = git_path("packed-refs");
273 f = fopen(packed_refs_file, "r");
274 if (f) {
275 read_packed_refs(f, &refs->packed);
276 fclose(f);
277 }
278 refs->did_packed = 1;
279 }
280 return &refs->packed;
281 }
282
283 static void get_ref_dir(const char *submodule, const char *base,
284 struct ref_array *array)
285 {
286 DIR *dir;
287 const char *path;
288
289 if (submodule)
290 path = git_path_submodule(submodule, "%s", base);
291 else
292 path = git_path("%s", base);
293
294
295 dir = opendir(path);
296
297 if (dir) {
298 struct dirent *de;
299 int baselen = strlen(base);
300 char *ref = xmalloc(baselen + 257);
301
302 memcpy(ref, base, baselen);
303 if (baselen && base[baselen-1] != '/')
304 ref[baselen++] = '/';
305
306 while ((de = readdir(dir)) != NULL) {
307 unsigned char sha1[20];
308 struct stat st;
309 int flag;
310 int namelen;
311 const char *refdir;
312
313 if (de->d_name[0] == '.')
314 continue;
315 namelen = strlen(de->d_name);
316 if (namelen > 255)
317 continue;
318 if (has_extension(de->d_name, ".lock"))
319 continue;
320 memcpy(ref + baselen, de->d_name, namelen+1);
321 refdir = submodule
322 ? git_path_submodule(submodule, "%s", ref)
323 : git_path("%s", ref);
324 if (stat(refdir, &st) < 0)
325 continue;
326 if (S_ISDIR(st.st_mode)) {
327 get_ref_dir(submodule, ref, array);
328 continue;
329 }
330 if (submodule) {
331 hashclr(sha1);
332 flag = 0;
333 if (resolve_gitlink_ref(submodule, ref, sha1) < 0) {
334 hashclr(sha1);
335 flag |= REF_ISBROKEN;
336 }
337 } else if (read_ref_full(ref, sha1, 1, &flag)) {
338 hashclr(sha1);
339 flag |= REF_ISBROKEN;
340 }
341 add_ref(ref, sha1, flag, 1, array, NULL);
342 }
343 free(ref);
344 closedir(dir);
345 }
346 }
347
348 struct warn_if_dangling_data {
349 FILE *fp;
350 const char *refname;
351 const char *msg_fmt;
352 };
353
354 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
355 int flags, void *cb_data)
356 {
357 struct warn_if_dangling_data *d = cb_data;
358 const char *resolves_to;
359 unsigned char junk[20];
360
361 if (!(flags & REF_ISSYMREF))
362 return 0;
363
364 resolves_to = resolve_ref(refname, junk, 0, NULL);
365 if (!resolves_to || strcmp(resolves_to, d->refname))
366 return 0;
367
368 fprintf(d->fp, d->msg_fmt, refname);
369 return 0;
370 }
371
372 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
373 {
374 struct warn_if_dangling_data data;
375
376 data.fp = fp;
377 data.refname = refname;
378 data.msg_fmt = msg_fmt;
379 for_each_rawref(warn_if_dangling_symref, &data);
380 }
381
382 static struct ref_array *get_loose_refs(const char *submodule)
383 {
384 struct ref_cache *refs = get_ref_cache(submodule);
385
386 if (!refs->did_loose) {
387 get_ref_dir(submodule, "refs", &refs->loose);
388 sort_ref_array(&refs->loose);
389 refs->did_loose = 1;
390 }
391 return &refs->loose;
392 }
393
394 /* We allow "recursive" symbolic refs. Only within reason, though */
395 #define MAXDEPTH 5
396 #define MAXREFLEN (1024)
397
398 /*
399 * Called by resolve_gitlink_ref_recursive() after it failed to read
400 * from "name", which is "module/.git/<refname>". Find <refname> in
401 * the packed-refs file for the submodule.
402 */
403 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
404 {
405 int retval = -1;
406 struct ref_entry *ref;
407 struct ref_array *array;
408
409 /* being defensive: resolve_gitlink_ref() did this for us */
410 if (pathlen < 6 || memcmp(name + pathlen - 6, "/.git/", 6))
411 die("Oops");
412 name[pathlen - 6] = '\0'; /* make it path to the submodule */
413 array = get_packed_refs(name);
414 ref = search_ref_array(array, refname);
415 if (ref != NULL) {
416 memcpy(result, ref->sha1, 20);
417 retval = 0;
418 }
419 return retval;
420 }
421
422 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
423 {
424 int fd, len = strlen(refname);
425 char buffer[128], *p;
426
427 if (recursion > MAXDEPTH || len > MAXREFLEN)
428 return -1;
429 memcpy(name + pathlen, refname, len+1);
430 fd = open(name, O_RDONLY);
431 if (fd < 0)
432 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
433
434 len = read(fd, buffer, sizeof(buffer)-1);
435 close(fd);
436 if (len < 0)
437 return -1;
438 while (len && isspace(buffer[len-1]))
439 len--;
440 buffer[len] = 0;
441
442 /* Was it a detached head or an old-fashioned symlink? */
443 if (!get_sha1_hex(buffer, result))
444 return 0;
445
446 /* Symref? */
447 if (strncmp(buffer, "ref:", 4))
448 return -1;
449 p = buffer + 4;
450 while (isspace(*p))
451 p++;
452
453 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
454 }
455
456 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
457 {
458 int len = strlen(path), retval;
459 char *gitdir;
460 const char *tmp;
461
462 while (len && path[len-1] == '/')
463 len--;
464 if (!len)
465 return -1;
466 gitdir = xmalloc(len + MAXREFLEN + 8);
467 memcpy(gitdir, path, len);
468 memcpy(gitdir + len, "/.git", 6);
469 len += 5;
470
471 tmp = read_gitfile(gitdir);
472 if (tmp) {
473 free(gitdir);
474 len = strlen(tmp);
475 gitdir = xmalloc(len + MAXREFLEN + 3);
476 memcpy(gitdir, tmp, len);
477 }
478 gitdir[len] = '/';
479 gitdir[++len] = '\0';
480 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
481 free(gitdir);
482 return retval;
483 }
484
485 /*
486 * Try to read ref from the packed references. On success, set sha1
487 * and return 0; otherwise, return -1.
488 */
489 static int get_packed_ref(const char *ref, unsigned char *sha1)
490 {
491 struct ref_array *packed = get_packed_refs(NULL);
492 struct ref_entry *entry = search_ref_array(packed, ref);
493 if (entry) {
494 hashcpy(sha1, entry->sha1);
495 return 0;
496 }
497 return -1;
498 }
499
500 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
501 {
502 int depth = MAXDEPTH;
503 ssize_t len;
504 char buffer[256];
505 static char ref_buffer[256];
506
507 if (flag)
508 *flag = 0;
509
510 if (check_refname_format(ref, REFNAME_ALLOW_ONELEVEL))
511 return NULL;
512
513 for (;;) {
514 char path[PATH_MAX];
515 struct stat st;
516 char *buf;
517 int fd;
518
519 if (--depth < 0)
520 return NULL;
521
522 git_snpath(path, sizeof(path), "%s", ref);
523
524 if (lstat(path, &st) < 0) {
525 if (errno != ENOENT)
526 return NULL;
527 /*
528 * The loose reference file does not exist;
529 * check for a packed reference.
530 */
531 if (!get_packed_ref(ref, sha1)) {
532 if (flag)
533 *flag |= REF_ISPACKED;
534 return ref;
535 }
536 /* The reference is not a packed reference, either. */
537 if (reading) {
538 return NULL;
539 } else {
540 hashclr(sha1);
541 return ref;
542 }
543 }
544
545 /* Follow "normalized" - ie "refs/.." symlinks by hand */
546 if (S_ISLNK(st.st_mode)) {
547 len = readlink(path, buffer, sizeof(buffer)-1);
548 if (len < 0)
549 return NULL;
550 buffer[len] = 0;
551 if (!prefixcmp(buffer, "refs/") &&
552 !check_refname_format(buffer, 0)) {
553 strcpy(ref_buffer, buffer);
554 ref = ref_buffer;
555 if (flag)
556 *flag |= REF_ISSYMREF;
557 continue;
558 }
559 }
560
561 /* Is it a directory? */
562 if (S_ISDIR(st.st_mode)) {
563 errno = EISDIR;
564 return NULL;
565 }
566
567 /*
568 * Anything else, just open it and try to use it as
569 * a ref
570 */
571 fd = open(path, O_RDONLY);
572 if (fd < 0)
573 return NULL;
574 len = read_in_full(fd, buffer, sizeof(buffer)-1);
575 close(fd);
576 if (len < 0)
577 return NULL;
578 while (len && isspace(buffer[len-1]))
579 len--;
580 buffer[len] = '\0';
581
582 /*
583 * Is it a symbolic ref?
584 */
585 if (prefixcmp(buffer, "ref:"))
586 break;
587 if (flag)
588 *flag |= REF_ISSYMREF;
589 buf = buffer + 4;
590 while (isspace(*buf))
591 buf++;
592 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
593 if (flag)
594 *flag |= REF_ISBROKEN;
595 return NULL;
596 }
597 ref = strcpy(ref_buffer, buf);
598 }
599 /* Please note that FETCH_HEAD has a second line containing other data. */
600 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
601 if (flag)
602 *flag |= REF_ISBROKEN;
603 return NULL;
604 }
605 return ref;
606 }
607
608 /* The argument to filter_refs */
609 struct ref_filter {
610 const char *pattern;
611 each_ref_fn *fn;
612 void *cb_data;
613 };
614
615 int read_ref_full(const char *ref, unsigned char *sha1, int reading, int *flags)
616 {
617 if (resolve_ref(ref, sha1, reading, flags))
618 return 0;
619 return -1;
620 }
621
622 int read_ref(const char *ref, unsigned char *sha1)
623 {
624 return read_ref_full(ref, sha1, 1, NULL);
625 }
626
627 #define DO_FOR_EACH_INCLUDE_BROKEN 01
628 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
629 int flags, void *cb_data, struct ref_entry *entry)
630 {
631 if (prefixcmp(entry->name, base))
632 return 0;
633
634 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
635 if (entry->flag & REF_ISBROKEN)
636 return 0; /* ignore broken refs e.g. dangling symref */
637 if (!has_sha1_file(entry->sha1)) {
638 error("%s does not point to a valid object!", entry->name);
639 return 0;
640 }
641 }
642 current_ref = entry;
643 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
644 }
645
646 static int filter_refs(const char *ref, const unsigned char *sha, int flags,
647 void *data)
648 {
649 struct ref_filter *filter = (struct ref_filter *)data;
650 if (fnmatch(filter->pattern, ref, 0))
651 return 0;
652 return filter->fn(ref, sha, flags, filter->cb_data);
653 }
654
655 int peel_ref(const char *ref, unsigned char *sha1)
656 {
657 int flag;
658 unsigned char base[20];
659 struct object *o;
660
661 if (current_ref && (current_ref->name == ref
662 || !strcmp(current_ref->name, ref))) {
663 if (current_ref->flag & REF_KNOWS_PEELED) {
664 hashcpy(sha1, current_ref->peeled);
665 return 0;
666 }
667 hashcpy(base, current_ref->sha1);
668 goto fallback;
669 }
670
671 if (read_ref_full(ref, base, 1, &flag))
672 return -1;
673
674 if ((flag & REF_ISPACKED)) {
675 struct ref_array *array = get_packed_refs(NULL);
676 struct ref_entry *r = search_ref_array(array, ref);
677
678 if (r != NULL && r->flag & REF_KNOWS_PEELED) {
679 hashcpy(sha1, r->peeled);
680 return 0;
681 }
682 }
683
684 fallback:
685 o = parse_object(base);
686 if (o && o->type == OBJ_TAG) {
687 o = deref_tag(o, ref, 0);
688 if (o) {
689 hashcpy(sha1, o->sha1);
690 return 0;
691 }
692 }
693 return -1;
694 }
695
696 static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
697 int trim, int flags, void *cb_data)
698 {
699 int retval = 0, i, p = 0, l = 0;
700 struct ref_array *packed = get_packed_refs(submodule);
701 struct ref_array *loose = get_loose_refs(submodule);
702
703 struct ref_array *extra = &extra_refs;
704
705 for (i = 0; i < extra->nr; i++)
706 retval = do_one_ref(base, fn, trim, flags, cb_data, extra->refs[i]);
707
708 while (p < packed->nr && l < loose->nr) {
709 struct ref_entry *entry;
710 int cmp = strcmp(packed->refs[p]->name, loose->refs[l]->name);
711 if (!cmp) {
712 p++;
713 continue;
714 }
715 if (cmp > 0) {
716 entry = loose->refs[l++];
717 } else {
718 entry = packed->refs[p++];
719 }
720 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
721 if (retval)
722 goto end_each;
723 }
724
725 if (l < loose->nr) {
726 p = l;
727 packed = loose;
728 }
729
730 for (; p < packed->nr; p++) {
731 retval = do_one_ref(base, fn, trim, flags, cb_data, packed->refs[p]);
732 if (retval)
733 goto end_each;
734 }
735
736 end_each:
737 current_ref = NULL;
738 return retval;
739 }
740
741
742 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
743 {
744 unsigned char sha1[20];
745 int flag;
746
747 if (submodule) {
748 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
749 return fn("HEAD", sha1, 0, cb_data);
750
751 return 0;
752 }
753
754 if (!read_ref_full("HEAD", sha1, 1, &flag))
755 return fn("HEAD", sha1, flag, cb_data);
756
757 return 0;
758 }
759
760 int head_ref(each_ref_fn fn, void *cb_data)
761 {
762 return do_head_ref(NULL, fn, cb_data);
763 }
764
765 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
766 {
767 return do_head_ref(submodule, fn, cb_data);
768 }
769
770 int for_each_ref(each_ref_fn fn, void *cb_data)
771 {
772 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
773 }
774
775 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
776 {
777 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
778 }
779
780 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
781 {
782 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
783 }
784
785 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
786 each_ref_fn fn, void *cb_data)
787 {
788 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
789 }
790
791 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
792 {
793 return for_each_ref_in("refs/tags/", fn, cb_data);
794 }
795
796 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
797 {
798 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
799 }
800
801 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
802 {
803 return for_each_ref_in("refs/heads/", fn, cb_data);
804 }
805
806 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
807 {
808 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
809 }
810
811 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
812 {
813 return for_each_ref_in("refs/remotes/", fn, cb_data);
814 }
815
816 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
817 {
818 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
819 }
820
821 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
822 {
823 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
824 }
825
826 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
827 {
828 struct strbuf buf = STRBUF_INIT;
829 int ret = 0;
830 unsigned char sha1[20];
831 int flag;
832
833 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
834 if (!read_ref_full(buf.buf, sha1, 1, &flag))
835 ret = fn(buf.buf, sha1, flag, cb_data);
836 strbuf_release(&buf);
837
838 return ret;
839 }
840
841 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
842 {
843 struct strbuf buf = STRBUF_INIT;
844 int ret;
845 strbuf_addf(&buf, "%srefs/", get_git_namespace());
846 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
847 strbuf_release(&buf);
848 return ret;
849 }
850
851 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
852 const char *prefix, void *cb_data)
853 {
854 struct strbuf real_pattern = STRBUF_INIT;
855 struct ref_filter filter;
856 int ret;
857
858 if (!prefix && prefixcmp(pattern, "refs/"))
859 strbuf_addstr(&real_pattern, "refs/");
860 else if (prefix)
861 strbuf_addstr(&real_pattern, prefix);
862 strbuf_addstr(&real_pattern, pattern);
863
864 if (!has_glob_specials(pattern)) {
865 /* Append implied '/' '*' if not present. */
866 if (real_pattern.buf[real_pattern.len - 1] != '/')
867 strbuf_addch(&real_pattern, '/');
868 /* No need to check for '*', there is none. */
869 strbuf_addch(&real_pattern, '*');
870 }
871
872 filter.pattern = real_pattern.buf;
873 filter.fn = fn;
874 filter.cb_data = cb_data;
875 ret = for_each_ref(filter_refs, &filter);
876
877 strbuf_release(&real_pattern);
878 return ret;
879 }
880
881 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
882 {
883 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
884 }
885
886 int for_each_rawref(each_ref_fn fn, void *cb_data)
887 {
888 return do_for_each_ref(NULL, "", fn, 0,
889 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
890 }
891
892 /*
893 * Make sure "ref" is something reasonable to have under ".git/refs/";
894 * We do not like it if:
895 *
896 * - any path component of it begins with ".", or
897 * - it has double dots "..", or
898 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
899 * - it ends with a "/".
900 * - it ends with ".lock"
901 * - it contains a "\" (backslash)
902 */
903
904 /* Return true iff ch is not allowed in reference names. */
905 static inline int bad_ref_char(int ch)
906 {
907 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
908 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
909 return 1;
910 /* 2.13 Pattern Matching Notation */
911 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
912 return 1;
913 return 0;
914 }
915
916 /*
917 * Try to read one refname component from the front of ref. Return
918 * the length of the component found, or -1 if the component is not
919 * legal.
920 */
921 static int check_refname_component(const char *ref, int flags)
922 {
923 const char *cp;
924 char last = '\0';
925
926 for (cp = ref; ; cp++) {
927 char ch = *cp;
928 if (ch == '\0' || ch == '/')
929 break;
930 if (bad_ref_char(ch))
931 return -1; /* Illegal character in refname. */
932 if (last == '.' && ch == '.')
933 return -1; /* Refname contains "..". */
934 if (last == '@' && ch == '{')
935 return -1; /* Refname contains "@{". */
936 last = ch;
937 }
938 if (cp == ref)
939 return -1; /* Component has zero length. */
940 if (ref[0] == '.') {
941 if (!(flags & REFNAME_DOT_COMPONENT))
942 return -1; /* Component starts with '.'. */
943 /*
944 * Even if leading dots are allowed, don't allow "."
945 * as a component (".." is prevented by a rule above).
946 */
947 if (ref[1] == '\0')
948 return -1; /* Component equals ".". */
949 }
950 if (cp - ref >= 5 && !memcmp(cp - 5, ".lock", 5))
951 return -1; /* Refname ends with ".lock". */
952 return cp - ref;
953 }
954
955 int check_refname_format(const char *ref, int flags)
956 {
957 int component_len, component_count = 0;
958
959 while (1) {
960 /* We are at the start of a path component. */
961 component_len = check_refname_component(ref, flags);
962 if (component_len < 0) {
963 if ((flags & REFNAME_REFSPEC_PATTERN) &&
964 ref[0] == '*' &&
965 (ref[1] == '\0' || ref[1] == '/')) {
966 /* Accept one wildcard as a full refname component. */
967 flags &= ~REFNAME_REFSPEC_PATTERN;
968 component_len = 1;
969 } else {
970 return -1;
971 }
972 }
973 component_count++;
974 if (ref[component_len] == '\0')
975 break;
976 /* Skip to next component. */
977 ref += component_len + 1;
978 }
979
980 if (ref[component_len - 1] == '.')
981 return -1; /* Refname ends with '.'. */
982 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
983 return -1; /* Refname has only one component. */
984 return 0;
985 }
986
987 const char *prettify_refname(const char *name)
988 {
989 return name + (
990 !prefixcmp(name, "refs/heads/") ? 11 :
991 !prefixcmp(name, "refs/tags/") ? 10 :
992 !prefixcmp(name, "refs/remotes/") ? 13 :
993 0);
994 }
995
996 const char *ref_rev_parse_rules[] = {
997 "%.*s",
998 "refs/%.*s",
999 "refs/tags/%.*s",
1000 "refs/heads/%.*s",
1001 "refs/remotes/%.*s",
1002 "refs/remotes/%.*s/HEAD",
1003 NULL
1004 };
1005
1006 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1007 {
1008 const char **p;
1009 const int abbrev_name_len = strlen(abbrev_name);
1010
1011 for (p = rules; *p; p++) {
1012 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1013 return 1;
1014 }
1015 }
1016
1017 return 0;
1018 }
1019
1020 static struct ref_lock *verify_lock(struct ref_lock *lock,
1021 const unsigned char *old_sha1, int mustexist)
1022 {
1023 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1024 error("Can't verify ref %s", lock->ref_name);
1025 unlock_ref(lock);
1026 return NULL;
1027 }
1028 if (hashcmp(lock->old_sha1, old_sha1)) {
1029 error("Ref %s is at %s but expected %s", lock->ref_name,
1030 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1031 unlock_ref(lock);
1032 return NULL;
1033 }
1034 return lock;
1035 }
1036
1037 static int remove_empty_directories(const char *file)
1038 {
1039 /* we want to create a file but there is a directory there;
1040 * if that is an empty directory (or a directory that contains
1041 * only empty directories), remove them.
1042 */
1043 struct strbuf path;
1044 int result;
1045
1046 strbuf_init(&path, 20);
1047 strbuf_addstr(&path, file);
1048
1049 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1050
1051 strbuf_release(&path);
1052
1053 return result;
1054 }
1055
1056 static int is_refname_available(const char *ref, const char *oldref,
1057 struct ref_array *array, int quiet)
1058 {
1059 int i, namlen = strlen(ref); /* e.g. 'foo/bar' */
1060 for (i = 0; i < array->nr; i++ ) {
1061 struct ref_entry *entry = array->refs[i];
1062 /* entry->name could be 'foo' or 'foo/bar/baz' */
1063 if (!oldref || strcmp(oldref, entry->name)) {
1064 int len = strlen(entry->name);
1065 int cmplen = (namlen < len) ? namlen : len;
1066 const char *lead = (namlen < len) ? entry->name : ref;
1067 if (!strncmp(ref, entry->name, cmplen) &&
1068 lead[cmplen] == '/') {
1069 if (!quiet)
1070 error("'%s' exists; cannot create '%s'",
1071 entry->name, ref);
1072 return 0;
1073 }
1074 }
1075 }
1076 return 1;
1077 }
1078
1079 /*
1080 * *string and *len will only be substituted, and *string returned (for
1081 * later free()ing) if the string passed in is a magic short-hand form
1082 * to name a branch.
1083 */
1084 static char *substitute_branch_name(const char **string, int *len)
1085 {
1086 struct strbuf buf = STRBUF_INIT;
1087 int ret = interpret_branch_name(*string, &buf);
1088
1089 if (ret == *len) {
1090 size_t size;
1091 *string = strbuf_detach(&buf, &size);
1092 *len = size;
1093 return (char *)*string;
1094 }
1095
1096 return NULL;
1097 }
1098
1099 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1100 {
1101 char *last_branch = substitute_branch_name(&str, &len);
1102 const char **p, *r;
1103 int refs_found = 0;
1104
1105 *ref = NULL;
1106 for (p = ref_rev_parse_rules; *p; p++) {
1107 char fullref[PATH_MAX];
1108 unsigned char sha1_from_ref[20];
1109 unsigned char *this_result;
1110 int flag;
1111
1112 this_result = refs_found ? sha1_from_ref : sha1;
1113 mksnpath(fullref, sizeof(fullref), *p, len, str);
1114 r = resolve_ref(fullref, this_result, 1, &flag);
1115 if (r) {
1116 if (!refs_found++)
1117 *ref = xstrdup(r);
1118 if (!warn_ambiguous_refs)
1119 break;
1120 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
1121 warning("ignoring dangling symref %s.", fullref);
1122 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1123 warning("ignoring broken ref %s.", fullref);
1124 }
1125 }
1126 free(last_branch);
1127 return refs_found;
1128 }
1129
1130 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1131 {
1132 char *last_branch = substitute_branch_name(&str, &len);
1133 const char **p;
1134 int logs_found = 0;
1135
1136 *log = NULL;
1137 for (p = ref_rev_parse_rules; *p; p++) {
1138 struct stat st;
1139 unsigned char hash[20];
1140 char path[PATH_MAX];
1141 const char *ref, *it;
1142
1143 mksnpath(path, sizeof(path), *p, len, str);
1144 ref = resolve_ref(path, hash, 1, NULL);
1145 if (!ref)
1146 continue;
1147 if (!stat(git_path("logs/%s", path), &st) &&
1148 S_ISREG(st.st_mode))
1149 it = path;
1150 else if (strcmp(ref, path) &&
1151 !stat(git_path("logs/%s", ref), &st) &&
1152 S_ISREG(st.st_mode))
1153 it = ref;
1154 else
1155 continue;
1156 if (!logs_found++) {
1157 *log = xstrdup(it);
1158 hashcpy(sha1, hash);
1159 }
1160 if (!warn_ambiguous_refs)
1161 break;
1162 }
1163 free(last_branch);
1164 return logs_found;
1165 }
1166
1167 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
1168 {
1169 char *ref_file;
1170 const char *orig_ref = ref;
1171 struct ref_lock *lock;
1172 int last_errno = 0;
1173 int type, lflags;
1174 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1175 int missing = 0;
1176
1177 lock = xcalloc(1, sizeof(struct ref_lock));
1178 lock->lock_fd = -1;
1179
1180 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
1181 if (!ref && errno == EISDIR) {
1182 /* we are trying to lock foo but we used to
1183 * have foo/bar which now does not exist;
1184 * it is normal for the empty directory 'foo'
1185 * to remain.
1186 */
1187 ref_file = git_path("%s", orig_ref);
1188 if (remove_empty_directories(ref_file)) {
1189 last_errno = errno;
1190 error("there are still refs under '%s'", orig_ref);
1191 goto error_return;
1192 }
1193 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
1194 }
1195 if (type_p)
1196 *type_p = type;
1197 if (!ref) {
1198 last_errno = errno;
1199 error("unable to resolve reference %s: %s",
1200 orig_ref, strerror(errno));
1201 goto error_return;
1202 }
1203 missing = is_null_sha1(lock->old_sha1);
1204 /* When the ref did not exist and we are creating it,
1205 * make sure there is no existing ref that is packed
1206 * whose name begins with our refname, nor a ref whose
1207 * name is a proper prefix of our refname.
1208 */
1209 if (missing &&
1210 !is_refname_available(ref, NULL, get_packed_refs(NULL), 0)) {
1211 last_errno = ENOTDIR;
1212 goto error_return;
1213 }
1214
1215 lock->lk = xcalloc(1, sizeof(struct lock_file));
1216
1217 lflags = LOCK_DIE_ON_ERROR;
1218 if (flags & REF_NODEREF) {
1219 ref = orig_ref;
1220 lflags |= LOCK_NODEREF;
1221 }
1222 lock->ref_name = xstrdup(ref);
1223 lock->orig_ref_name = xstrdup(orig_ref);
1224 ref_file = git_path("%s", ref);
1225 if (missing)
1226 lock->force_write = 1;
1227 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1228 lock->force_write = 1;
1229
1230 if (safe_create_leading_directories(ref_file)) {
1231 last_errno = errno;
1232 error("unable to create directory for %s", ref_file);
1233 goto error_return;
1234 }
1235
1236 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
1237 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
1238
1239 error_return:
1240 unlock_ref(lock);
1241 errno = last_errno;
1242 return NULL;
1243 }
1244
1245 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
1246 {
1247 char refpath[PATH_MAX];
1248 if (check_refname_format(ref, 0))
1249 return NULL;
1250 strcpy(refpath, mkpath("refs/%s", ref));
1251 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
1252 }
1253
1254 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
1255 {
1256 if (check_refname_format(ref, REFNAME_ALLOW_ONELEVEL))
1257 return NULL;
1258 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
1259 }
1260
1261 static struct lock_file packlock;
1262
1263 static int repack_without_ref(const char *refname)
1264 {
1265 struct ref_array *packed;
1266 struct ref_entry *ref;
1267 int fd, i;
1268
1269 packed = get_packed_refs(NULL);
1270 ref = search_ref_array(packed, refname);
1271 if (ref == NULL)
1272 return 0;
1273 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1274 if (fd < 0) {
1275 unable_to_lock_error(git_path("packed-refs"), errno);
1276 return error("cannot delete '%s' from packed refs", refname);
1277 }
1278
1279 for (i = 0; i < packed->nr; i++) {
1280 char line[PATH_MAX + 100];
1281 int len;
1282
1283 ref = packed->refs[i];
1284
1285 if (!strcmp(refname, ref->name))
1286 continue;
1287 len = snprintf(line, sizeof(line), "%s %s\n",
1288 sha1_to_hex(ref->sha1), ref->name);
1289 /* this should not happen but just being defensive */
1290 if (len > sizeof(line))
1291 die("too long a refname '%s'", ref->name);
1292 write_or_die(fd, line, len);
1293 }
1294 return commit_lock_file(&packlock);
1295 }
1296
1297 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
1298 {
1299 struct ref_lock *lock;
1300 int err, i = 0, ret = 0, flag = 0;
1301
1302 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
1303 if (!lock)
1304 return 1;
1305 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
1306 /* loose */
1307 const char *path;
1308
1309 if (!(delopt & REF_NODEREF)) {
1310 i = strlen(lock->lk->filename) - 5; /* .lock */
1311 lock->lk->filename[i] = 0;
1312 path = lock->lk->filename;
1313 } else {
1314 path = git_path("%s", refname);
1315 }
1316 err = unlink_or_warn(path);
1317 if (err && errno != ENOENT)
1318 ret = 1;
1319
1320 if (!(delopt & REF_NODEREF))
1321 lock->lk->filename[i] = '.';
1322 }
1323 /* removing the loose one could have resurrected an earlier
1324 * packed one. Also, if it was not loose we need to repack
1325 * without it.
1326 */
1327 ret |= repack_without_ref(refname);
1328
1329 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1330 invalidate_ref_cache(NULL);
1331 unlock_ref(lock);
1332 return ret;
1333 }
1334
1335 /*
1336 * People using contrib's git-new-workdir have .git/logs/refs ->
1337 * /some/other/path/.git/logs/refs, and that may live on another device.
1338 *
1339 * IOW, to avoid cross device rename errors, the temporary renamed log must
1340 * live into logs/refs.
1341 */
1342 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1343
1344 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
1345 {
1346 unsigned char sha1[20], orig_sha1[20];
1347 int flag = 0, logmoved = 0;
1348 struct ref_lock *lock;
1349 struct stat loginfo;
1350 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
1351 const char *symref = NULL;
1352
1353 if (log && S_ISLNK(loginfo.st_mode))
1354 return error("reflog for %s is a symlink", oldref);
1355
1356 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1357 if (flag & REF_ISSYMREF)
1358 return error("refname %s is a symbolic ref, renaming it is not supported",
1359 oldref);
1360 if (!symref)
1361 return error("refname %s not found", oldref);
1362
1363 if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
1364 return 1;
1365
1366 if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
1367 return 1;
1368
1369 if (log && rename(git_path("logs/%s", oldref), git_path(TMP_RENAMED_LOG)))
1370 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
1371 oldref, strerror(errno));
1372
1373 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
1374 error("unable to delete old %s", oldref);
1375 goto rollback;
1376 }
1377
1378 if (!read_ref_full(newref, sha1, 1, &flag) &&
1379 delete_ref(newref, sha1, REF_NODEREF)) {
1380 if (errno==EISDIR) {
1381 if (remove_empty_directories(git_path("%s", newref))) {
1382 error("Directory not empty: %s", newref);
1383 goto rollback;
1384 }
1385 } else {
1386 error("unable to delete existing %s", newref);
1387 goto rollback;
1388 }
1389 }
1390
1391 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1392 error("unable to create directory for %s", newref);
1393 goto rollback;
1394 }
1395
1396 retry:
1397 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newref))) {
1398 if (errno==EISDIR || errno==ENOTDIR) {
1399 /*
1400 * rename(a, b) when b is an existing
1401 * directory ought to result in ISDIR, but
1402 * Solaris 5.8 gives ENOTDIR. Sheesh.
1403 */
1404 if (remove_empty_directories(git_path("logs/%s", newref))) {
1405 error("Directory not empty: logs/%s", newref);
1406 goto rollback;
1407 }
1408 goto retry;
1409 } else {
1410 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
1411 newref, strerror(errno));
1412 goto rollback;
1413 }
1414 }
1415 logmoved = log;
1416
1417 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1418 if (!lock) {
1419 error("unable to lock %s for update", newref);
1420 goto rollback;
1421 }
1422 lock->force_write = 1;
1423 hashcpy(lock->old_sha1, orig_sha1);
1424 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1425 error("unable to write current sha1 into %s", newref);
1426 goto rollback;
1427 }
1428
1429 return 0;
1430
1431 rollback:
1432 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1433 if (!lock) {
1434 error("unable to lock %s for rollback", oldref);
1435 goto rollbacklog;
1436 }
1437
1438 lock->force_write = 1;
1439 flag = log_all_ref_updates;
1440 log_all_ref_updates = 0;
1441 if (write_ref_sha1(lock, orig_sha1, NULL))
1442 error("unable to write current sha1 into %s", oldref);
1443 log_all_ref_updates = flag;
1444
1445 rollbacklog:
1446 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1447 error("unable to restore logfile %s from %s: %s",
1448 oldref, newref, strerror(errno));
1449 if (!logmoved && log &&
1450 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldref)))
1451 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
1452 oldref, strerror(errno));
1453
1454 return 1;
1455 }
1456
1457 int close_ref(struct ref_lock *lock)
1458 {
1459 if (close_lock_file(lock->lk))
1460 return -1;
1461 lock->lock_fd = -1;
1462 return 0;
1463 }
1464
1465 int commit_ref(struct ref_lock *lock)
1466 {
1467 if (commit_lock_file(lock->lk))
1468 return -1;
1469 lock->lock_fd = -1;
1470 return 0;
1471 }
1472
1473 void unlock_ref(struct ref_lock *lock)
1474 {
1475 /* Do not free lock->lk -- atexit() still looks at them */
1476 if (lock->lk)
1477 rollback_lock_file(lock->lk);
1478 free(lock->ref_name);
1479 free(lock->orig_ref_name);
1480 free(lock);
1481 }
1482
1483 /*
1484 * copy the reflog message msg to buf, which has been allocated sufficiently
1485 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1486 * because reflog file is one line per entry.
1487 */
1488 static int copy_msg(char *buf, const char *msg)
1489 {
1490 char *cp = buf;
1491 char c;
1492 int wasspace = 1;
1493
1494 *cp++ = '\t';
1495 while ((c = *msg++)) {
1496 if (wasspace && isspace(c))
1497 continue;
1498 wasspace = isspace(c);
1499 if (wasspace)
1500 c = ' ';
1501 *cp++ = c;
1502 }
1503 while (buf < cp && isspace(cp[-1]))
1504 cp--;
1505 *cp++ = '\n';
1506 return cp - buf;
1507 }
1508
1509 int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
1510 {
1511 int logfd, oflags = O_APPEND | O_WRONLY;
1512
1513 git_snpath(logfile, bufsize, "logs/%s", ref_name);
1514 if (log_all_ref_updates &&
1515 (!prefixcmp(ref_name, "refs/heads/") ||
1516 !prefixcmp(ref_name, "refs/remotes/") ||
1517 !prefixcmp(ref_name, "refs/notes/") ||
1518 !strcmp(ref_name, "HEAD"))) {
1519 if (safe_create_leading_directories(logfile) < 0)
1520 return error("unable to create directory for %s",
1521 logfile);
1522 oflags |= O_CREAT;
1523 }
1524
1525 logfd = open(logfile, oflags, 0666);
1526 if (logfd < 0) {
1527 if (!(oflags & O_CREAT) && errno == ENOENT)
1528 return 0;
1529
1530 if ((oflags & O_CREAT) && errno == EISDIR) {
1531 if (remove_empty_directories(logfile)) {
1532 return error("There are still logs under '%s'",
1533 logfile);
1534 }
1535 logfd = open(logfile, oflags, 0666);
1536 }
1537
1538 if (logfd < 0)
1539 return error("Unable to append to %s: %s",
1540 logfile, strerror(errno));
1541 }
1542
1543 adjust_shared_perm(logfile);
1544 close(logfd);
1545 return 0;
1546 }
1547
1548 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1549 const unsigned char *new_sha1, const char *msg)
1550 {
1551 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1552 unsigned maxlen, len;
1553 int msglen;
1554 char log_file[PATH_MAX];
1555 char *logrec;
1556 const char *committer;
1557
1558 if (log_all_ref_updates < 0)
1559 log_all_ref_updates = !is_bare_repository();
1560
1561 result = log_ref_setup(ref_name, log_file, sizeof(log_file));
1562 if (result)
1563 return result;
1564
1565 logfd = open(log_file, oflags);
1566 if (logfd < 0)
1567 return 0;
1568 msglen = msg ? strlen(msg) : 0;
1569 committer = git_committer_info(0);
1570 maxlen = strlen(committer) + msglen + 100;
1571 logrec = xmalloc(maxlen);
1572 len = sprintf(logrec, "%s %s %s\n",
1573 sha1_to_hex(old_sha1),
1574 sha1_to_hex(new_sha1),
1575 committer);
1576 if (msglen)
1577 len += copy_msg(logrec + len - 1, msg) - 1;
1578 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1579 free(logrec);
1580 if (close(logfd) != 0 || written != len)
1581 return error("Unable to append to %s", log_file);
1582 return 0;
1583 }
1584
1585 static int is_branch(const char *refname)
1586 {
1587 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1588 }
1589
1590 int write_ref_sha1(struct ref_lock *lock,
1591 const unsigned char *sha1, const char *logmsg)
1592 {
1593 static char term = '\n';
1594 struct object *o;
1595
1596 if (!lock)
1597 return -1;
1598 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1599 unlock_ref(lock);
1600 return 0;
1601 }
1602 o = parse_object(sha1);
1603 if (!o) {
1604 error("Trying to write ref %s with nonexistent object %s",
1605 lock->ref_name, sha1_to_hex(sha1));
1606 unlock_ref(lock);
1607 return -1;
1608 }
1609 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1610 error("Trying to write non-commit object %s to branch %s",
1611 sha1_to_hex(sha1), lock->ref_name);
1612 unlock_ref(lock);
1613 return -1;
1614 }
1615 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1616 write_in_full(lock->lock_fd, &term, 1) != 1
1617 || close_ref(lock) < 0) {
1618 error("Couldn't write %s", lock->lk->filename);
1619 unlock_ref(lock);
1620 return -1;
1621 }
1622 clear_loose_ref_cache(get_ref_cache(NULL));
1623 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1624 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1625 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1626 unlock_ref(lock);
1627 return -1;
1628 }
1629 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1630 /*
1631 * Special hack: If a branch is updated directly and HEAD
1632 * points to it (may happen on the remote side of a push
1633 * for example) then logically the HEAD reflog should be
1634 * updated too.
1635 * A generic solution implies reverse symref information,
1636 * but finding all symrefs pointing to the given branch
1637 * would be rather costly for this rare event (the direct
1638 * update of a branch) to be worth it. So let's cheat and
1639 * check with HEAD only which should cover 99% of all usage
1640 * scenarios (even 100% of the default ones).
1641 */
1642 unsigned char head_sha1[20];
1643 int head_flag;
1644 const char *head_ref;
1645 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1646 if (head_ref && (head_flag & REF_ISSYMREF) &&
1647 !strcmp(head_ref, lock->ref_name))
1648 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1649 }
1650 if (commit_ref(lock)) {
1651 error("Couldn't set %s", lock->ref_name);
1652 unlock_ref(lock);
1653 return -1;
1654 }
1655 unlock_ref(lock);
1656 return 0;
1657 }
1658
1659 int create_symref(const char *ref_target, const char *refs_heads_master,
1660 const char *logmsg)
1661 {
1662 const char *lockpath;
1663 char ref[1000];
1664 int fd, len, written;
1665 char *git_HEAD = git_pathdup("%s", ref_target);
1666 unsigned char old_sha1[20], new_sha1[20];
1667
1668 if (logmsg && read_ref(ref_target, old_sha1))
1669 hashclr(old_sha1);
1670
1671 if (safe_create_leading_directories(git_HEAD) < 0)
1672 return error("unable to create directory for %s", git_HEAD);
1673
1674 #ifndef NO_SYMLINK_HEAD
1675 if (prefer_symlink_refs) {
1676 unlink(git_HEAD);
1677 if (!symlink(refs_heads_master, git_HEAD))
1678 goto done;
1679 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1680 }
1681 #endif
1682
1683 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1684 if (sizeof(ref) <= len) {
1685 error("refname too long: %s", refs_heads_master);
1686 goto error_free_return;
1687 }
1688 lockpath = mkpath("%s.lock", git_HEAD);
1689 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1690 if (fd < 0) {
1691 error("Unable to open %s for writing", lockpath);
1692 goto error_free_return;
1693 }
1694 written = write_in_full(fd, ref, len);
1695 if (close(fd) != 0 || written != len) {
1696 error("Unable to write to %s", lockpath);
1697 goto error_unlink_return;
1698 }
1699 if (rename(lockpath, git_HEAD) < 0) {
1700 error("Unable to create %s", git_HEAD);
1701 goto error_unlink_return;
1702 }
1703 if (adjust_shared_perm(git_HEAD)) {
1704 error("Unable to fix permissions on %s", lockpath);
1705 error_unlink_return:
1706 unlink_or_warn(lockpath);
1707 error_free_return:
1708 free(git_HEAD);
1709 return -1;
1710 }
1711
1712 #ifndef NO_SYMLINK_HEAD
1713 done:
1714 #endif
1715 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1716 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1717
1718 free(git_HEAD);
1719 return 0;
1720 }
1721
1722 static char *ref_msg(const char *line, const char *endp)
1723 {
1724 const char *ep;
1725 line += 82;
1726 ep = memchr(line, '\n', endp - line);
1727 if (!ep)
1728 ep = endp;
1729 return xmemdupz(line, ep - line);
1730 }
1731
1732 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)
1733 {
1734 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1735 char *tz_c;
1736 int logfd, tz, reccnt = 0;
1737 struct stat st;
1738 unsigned long date;
1739 unsigned char logged_sha1[20];
1740 void *log_mapped;
1741 size_t mapsz;
1742
1743 logfile = git_path("logs/%s", ref);
1744 logfd = open(logfile, O_RDONLY, 0);
1745 if (logfd < 0)
1746 die_errno("Unable to read log '%s'", logfile);
1747 fstat(logfd, &st);
1748 if (!st.st_size)
1749 die("Log %s is empty.", logfile);
1750 mapsz = xsize_t(st.st_size);
1751 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1752 logdata = log_mapped;
1753 close(logfd);
1754
1755 lastrec = NULL;
1756 rec = logend = logdata + st.st_size;
1757 while (logdata < rec) {
1758 reccnt++;
1759 if (logdata < rec && *(rec-1) == '\n')
1760 rec--;
1761 lastgt = NULL;
1762 while (logdata < rec && *(rec-1) != '\n') {
1763 rec--;
1764 if (*rec == '>')
1765 lastgt = rec;
1766 }
1767 if (!lastgt)
1768 die("Log %s is corrupt.", logfile);
1769 date = strtoul(lastgt + 1, &tz_c, 10);
1770 if (date <= at_time || cnt == 0) {
1771 tz = strtoul(tz_c, NULL, 10);
1772 if (msg)
1773 *msg = ref_msg(rec, logend);
1774 if (cutoff_time)
1775 *cutoff_time = date;
1776 if (cutoff_tz)
1777 *cutoff_tz = tz;
1778 if (cutoff_cnt)
1779 *cutoff_cnt = reccnt - 1;
1780 if (lastrec) {
1781 if (get_sha1_hex(lastrec, logged_sha1))
1782 die("Log %s is corrupt.", logfile);
1783 if (get_sha1_hex(rec + 41, sha1))
1784 die("Log %s is corrupt.", logfile);
1785 if (hashcmp(logged_sha1, sha1)) {
1786 warning("Log %s has gap after %s.",
1787 logfile, show_date(date, tz, DATE_RFC2822));
1788 }
1789 }
1790 else if (date == at_time) {
1791 if (get_sha1_hex(rec + 41, sha1))
1792 die("Log %s is corrupt.", logfile);
1793 }
1794 else {
1795 if (get_sha1_hex(rec + 41, logged_sha1))
1796 die("Log %s is corrupt.", logfile);
1797 if (hashcmp(logged_sha1, sha1)) {
1798 warning("Log %s unexpectedly ended on %s.",
1799 logfile, show_date(date, tz, DATE_RFC2822));
1800 }
1801 }
1802 munmap(log_mapped, mapsz);
1803 return 0;
1804 }
1805 lastrec = rec;
1806 if (cnt > 0)
1807 cnt--;
1808 }
1809
1810 rec = logdata;
1811 while (rec < logend && *rec != '>' && *rec != '\n')
1812 rec++;
1813 if (rec == logend || *rec == '\n')
1814 die("Log %s is corrupt.", logfile);
1815 date = strtoul(rec + 1, &tz_c, 10);
1816 tz = strtoul(tz_c, NULL, 10);
1817 if (get_sha1_hex(logdata, sha1))
1818 die("Log %s is corrupt.", logfile);
1819 if (is_null_sha1(sha1)) {
1820 if (get_sha1_hex(logdata + 41, sha1))
1821 die("Log %s is corrupt.", logfile);
1822 }
1823 if (msg)
1824 *msg = ref_msg(logdata, logend);
1825 munmap(log_mapped, mapsz);
1826
1827 if (cutoff_time)
1828 *cutoff_time = date;
1829 if (cutoff_tz)
1830 *cutoff_tz = tz;
1831 if (cutoff_cnt)
1832 *cutoff_cnt = reccnt;
1833 return 1;
1834 }
1835
1836 int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
1837 {
1838 const char *logfile;
1839 FILE *logfp;
1840 struct strbuf sb = STRBUF_INIT;
1841 int ret = 0;
1842
1843 logfile = git_path("logs/%s", ref);
1844 logfp = fopen(logfile, "r");
1845 if (!logfp)
1846 return -1;
1847
1848 if (ofs) {
1849 struct stat statbuf;
1850 if (fstat(fileno(logfp), &statbuf) ||
1851 statbuf.st_size < ofs ||
1852 fseek(logfp, -ofs, SEEK_END) ||
1853 strbuf_getwholeline(&sb, logfp, '\n')) {
1854 fclose(logfp);
1855 strbuf_release(&sb);
1856 return -1;
1857 }
1858 }
1859
1860 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
1861 unsigned char osha1[20], nsha1[20];
1862 char *email_end, *message;
1863 unsigned long timestamp;
1864 int tz;
1865
1866 /* old SP new SP name <email> SP time TAB msg LF */
1867 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
1868 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
1869 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
1870 !(email_end = strchr(sb.buf + 82, '>')) ||
1871 email_end[1] != ' ' ||
1872 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1873 !message || message[0] != ' ' ||
1874 (message[1] != '+' && message[1] != '-') ||
1875 !isdigit(message[2]) || !isdigit(message[3]) ||
1876 !isdigit(message[4]) || !isdigit(message[5]))
1877 continue; /* corrupt? */
1878 email_end[1] = '\0';
1879 tz = strtol(message + 1, NULL, 10);
1880 if (message[6] != '\t')
1881 message += 6;
1882 else
1883 message += 7;
1884 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
1885 cb_data);
1886 if (ret)
1887 break;
1888 }
1889 fclose(logfp);
1890 strbuf_release(&sb);
1891 return ret;
1892 }
1893
1894 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1895 {
1896 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1897 }
1898
1899 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1900 {
1901 DIR *dir = opendir(git_path("logs/%s", base));
1902 int retval = 0;
1903
1904 if (dir) {
1905 struct dirent *de;
1906 int baselen = strlen(base);
1907 char *log = xmalloc(baselen + 257);
1908
1909 memcpy(log, base, baselen);
1910 if (baselen && base[baselen-1] != '/')
1911 log[baselen++] = '/';
1912
1913 while ((de = readdir(dir)) != NULL) {
1914 struct stat st;
1915 int namelen;
1916
1917 if (de->d_name[0] == '.')
1918 continue;
1919 namelen = strlen(de->d_name);
1920 if (namelen > 255)
1921 continue;
1922 if (has_extension(de->d_name, ".lock"))
1923 continue;
1924 memcpy(log + baselen, de->d_name, namelen+1);
1925 if (stat(git_path("logs/%s", log), &st) < 0)
1926 continue;
1927 if (S_ISDIR(st.st_mode)) {
1928 retval = do_for_each_reflog(log, fn, cb_data);
1929 } else {
1930 unsigned char sha1[20];
1931 if (read_ref_full(log, sha1, 0, NULL))
1932 retval = error("bad ref for %s", log);
1933 else
1934 retval = fn(log, sha1, 0, cb_data);
1935 }
1936 if (retval)
1937 break;
1938 }
1939 free(log);
1940 closedir(dir);
1941 }
1942 else if (*base)
1943 return errno;
1944 return retval;
1945 }
1946
1947 int for_each_reflog(each_ref_fn fn, void *cb_data)
1948 {
1949 return do_for_each_reflog("", fn, cb_data);
1950 }
1951
1952 int update_ref(const char *action, const char *refname,
1953 const unsigned char *sha1, const unsigned char *oldval,
1954 int flags, enum action_on_err onerr)
1955 {
1956 static struct ref_lock *lock;
1957 lock = lock_any_ref_for_update(refname, oldval, flags);
1958 if (!lock) {
1959 const char *str = "Cannot lock the ref '%s'.";
1960 switch (onerr) {
1961 case MSG_ON_ERR: error(str, refname); break;
1962 case DIE_ON_ERR: die(str, refname); break;
1963 case QUIET_ON_ERR: break;
1964 }
1965 return 1;
1966 }
1967 if (write_ref_sha1(lock, sha1, action) < 0) {
1968 const char *str = "Cannot update the ref '%s'.";
1969 switch (onerr) {
1970 case MSG_ON_ERR: error(str, refname); break;
1971 case DIE_ON_ERR: die(str, refname); break;
1972 case QUIET_ON_ERR: break;
1973 }
1974 return 1;
1975 }
1976 return 0;
1977 }
1978
1979 int ref_exists(const char *refname)
1980 {
1981 unsigned char sha1[20];
1982 return !!resolve_ref(refname, sha1, 1, NULL);
1983 }
1984
1985 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1986 {
1987 for ( ; list; list = list->next)
1988 if (!strcmp(list->name, name))
1989 return (struct ref *)list;
1990 return NULL;
1991 }
1992
1993 /*
1994 * generate a format suitable for scanf from a ref_rev_parse_rules
1995 * rule, that is replace the "%.*s" spec with a "%s" spec
1996 */
1997 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1998 {
1999 char *spec;
2000
2001 spec = strstr(rule, "%.*s");
2002 if (!spec || strstr(spec + 4, "%.*s"))
2003 die("invalid rule in ref_rev_parse_rules: %s", rule);
2004
2005 /* copy all until spec */
2006 strncpy(scanf_fmt, rule, spec - rule);
2007 scanf_fmt[spec - rule] = '\0';
2008 /* copy new spec */
2009 strcat(scanf_fmt, "%s");
2010 /* copy remaining rule */
2011 strcat(scanf_fmt, spec + 4);
2012
2013 return;
2014 }
2015
2016 char *shorten_unambiguous_ref(const char *ref, int strict)
2017 {
2018 int i;
2019 static char **scanf_fmts;
2020 static int nr_rules;
2021 char *short_name;
2022
2023 /* pre generate scanf formats from ref_rev_parse_rules[] */
2024 if (!nr_rules) {
2025 size_t total_len = 0;
2026
2027 /* the rule list is NULL terminated, count them first */
2028 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2029 /* no +1 because strlen("%s") < strlen("%.*s") */
2030 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2031
2032 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2033
2034 total_len = 0;
2035 for (i = 0; i < nr_rules; i++) {
2036 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2037 + total_len;
2038 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2039 total_len += strlen(ref_rev_parse_rules[i]);
2040 }
2041 }
2042
2043 /* bail out if there are no rules */
2044 if (!nr_rules)
2045 return xstrdup(ref);
2046
2047 /* buffer for scanf result, at most ref must fit */
2048 short_name = xstrdup(ref);
2049
2050 /* skip first rule, it will always match */
2051 for (i = nr_rules - 1; i > 0 ; --i) {
2052 int j;
2053 int rules_to_fail = i;
2054 int short_name_len;
2055
2056 if (1 != sscanf(ref, scanf_fmts[i], short_name))
2057 continue;
2058
2059 short_name_len = strlen(short_name);
2060
2061 /*
2062 * in strict mode, all (except the matched one) rules
2063 * must fail to resolve to a valid non-ambiguous ref
2064 */
2065 if (strict)
2066 rules_to_fail = nr_rules;
2067
2068 /*
2069 * check if the short name resolves to a valid ref,
2070 * but use only rules prior to the matched one
2071 */
2072 for (j = 0; j < rules_to_fail; j++) {
2073 const char *rule = ref_rev_parse_rules[j];
2074 char refname[PATH_MAX];
2075
2076 /* skip matched rule */
2077 if (i == j)
2078 continue;
2079
2080 /*
2081 * the short name is ambiguous, if it resolves
2082 * (with this previous rule) to a valid ref
2083 * read_ref() returns 0 on success
2084 */
2085 mksnpath(refname, sizeof(refname),
2086 rule, short_name_len, short_name);
2087 if (ref_exists(refname))
2088 break;
2089 }
2090
2091 /*
2092 * short name is non-ambiguous if all previous rules
2093 * haven't resolved to a valid ref
2094 */
2095 if (j == rules_to_fail)
2096 return short_name;
2097 }
2098
2099 free(short_name);
2100 return xstrdup(ref);
2101 }