Extract a function clear_cached_refs()
[git/git.git] / refs.c
CommitLineData
95fc7512 1#include "cache.h"
85023577 2#include "refs.h"
cf0adba7
JH
3#include "object.h"
4#include "tag.h"
7155b727 5#include "dir.h"
95fc7512 6
f4204ab9
JH
7/* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8#define REF_KNOWS_PEELED 04
e01de1c9 9#define REF_BROKEN 010
f4204ab9 10
e1e22e37
LT
11struct ref_list {
12 struct ref_list *next;
f4204ab9 13 unsigned char flag; /* ISSYMREF? ISPACKED? */
e1e22e37 14 unsigned char sha1[20];
f4204ab9 15 unsigned char peeled[20];
e1e22e37
LT
16 char name[FLEX_ARRAY];
17};
18
f4204ab9 19static const char *parse_ref_line(char *line, unsigned char *sha1)
e1e22e37
LT
20{
21 /*
22 * 42: the answer to everything.
23 *
24 * In this case, it happens to be the answer to
25 * 40 (length of sha1 hex representation)
26 * +1 (space in between hex and name)
27 * +1 (newline at the end of the line)
28 */
29 int len = strlen(line) - 42;
30
31 if (len <= 0)
32 return NULL;
33 if (get_sha1_hex(line, sha1) < 0)
34 return NULL;
35 if (!isspace(line[40]))
36 return NULL;
37 line += 41;
f4204ab9
JH
38 if (isspace(*line))
39 return NULL;
e1e22e37
LT
40 if (line[len] != '\n')
41 return NULL;
42 line[len] = 0;
cf0adba7 43
e1e22e37
LT
44 return line;
45}
46
8da19775 47static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
f4204ab9
JH
48 int flag, struct ref_list *list,
49 struct ref_list **new_entry)
e1e22e37
LT
50{
51 int len;
c774aab9 52 struct ref_list *entry;
e1e22e37
LT
53
54 /* Allocate it and add it in.. */
55 len = strlen(name) + 1;
56 entry = xmalloc(sizeof(struct ref_list) + len);
57 hashcpy(entry->sha1, sha1);
f4204ab9 58 hashclr(entry->peeled);
e1e22e37 59 memcpy(entry->name, name, len);
8da19775 60 entry->flag = flag;
c774aab9 61 entry->next = list;
f4204ab9
JH
62 if (new_entry)
63 *new_entry = entry;
c774aab9
JP
64 return entry;
65}
66
67/* merge sort the ref list */
68static struct ref_list *sort_ref_list(struct ref_list *list)
69{
70 int psize, qsize, last_merge_count, cmp;
71 struct ref_list *p, *q, *l, *e;
72 struct ref_list *new_list = list;
73 int k = 1;
74 int merge_count = 0;
75
76 if (!list)
77 return list;
78
79 do {
80 last_merge_count = merge_count;
81 merge_count = 0;
82
83 psize = 0;
84
85 p = new_list;
86 q = new_list;
87 new_list = NULL;
88 l = NULL;
89
90 while (p) {
91 merge_count++;
92
93 while (psize < k && q->next) {
94 q = q->next;
95 psize++;
96 }
97 qsize = k;
98
99 while ((psize > 0) || (qsize > 0 && q)) {
100 if (qsize == 0 || !q) {
101 e = p;
102 p = p->next;
103 psize--;
104 } else if (psize == 0) {
105 e = q;
106 q = q->next;
107 qsize--;
108 } else {
109 cmp = strcmp(q->name, p->name);
110 if (cmp < 0) {
111 e = q;
112 q = q->next;
113 qsize--;
114 } else if (cmp > 0) {
115 e = p;
116 p = p->next;
117 psize--;
118 } else {
119 if (hashcmp(q->sha1, p->sha1))
120 die("Duplicated ref, and SHA1s don't match: %s",
121 q->name);
122 warning("Duplicated ref: %s", q->name);
123 e = q;
124 q = q->next;
125 qsize--;
126 free(e);
127 e = p;
128 p = p->next;
129 psize--;
130 }
131 }
132
133 e->next = NULL;
134
135 if (l)
136 l->next = e;
137 if (!new_list)
138 new_list = e;
139 l = e;
140 }
141
142 p = q;
143 };
144
145 k = k * 2;
146 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
147
148 return new_list;
e1e22e37
LT
149}
150
5e290ff7
JH
151/*
152 * Future: need to be in "struct repository"
153 * when doing a full libification.
154 */
4175e9e3 155static struct cached_refs {
5e290ff7
JH
156 char did_loose;
157 char did_packed;
158 struct ref_list *loose;
159 struct ref_list *packed;
0bad611b 160} cached_refs, submodule_refs;
0ae91be0 161static struct ref_list *current_ref;
5e290ff7 162
e142a3c6
DB
163static struct ref_list *extra_refs;
164
5e290ff7
JH
165static void free_ref_list(struct ref_list *list)
166{
167 struct ref_list *next;
168 for ( ; list; list = next) {
169 next = list->next;
170 free(list);
171 }
172}
173
f130b116 174static void clear_cached_refs(struct cached_refs *ca)
e1e22e37 175{
5e290ff7
JH
176 if (ca->did_loose && ca->loose)
177 free_ref_list(ca->loose);
178 if (ca->did_packed && ca->packed)
179 free_ref_list(ca->packed);
180 ca->loose = ca->packed = NULL;
181 ca->did_loose = ca->did_packed = 0;
f130b116
MH
182}
183
184static void invalidate_cached_refs(void)
185{
186 clear_cached_refs(&cached_refs);
5e290ff7 187}
e1e22e37 188
f4204ab9
JH
189static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
190{
191 struct ref_list *list = NULL;
192 struct ref_list *last = NULL;
193 char refline[PATH_MAX];
194 int flag = REF_ISPACKED;
195
196 while (fgets(refline, sizeof(refline), f)) {
197 unsigned char sha1[20];
198 const char *name;
199 static const char header[] = "# pack-refs with:";
200
201 if (!strncmp(refline, header, sizeof(header)-1)) {
202 const char *traits = refline + sizeof(header) - 1;
203 if (strstr(traits, " peeled "))
204 flag |= REF_KNOWS_PEELED;
205 /* perhaps other traits later as well */
206 continue;
207 }
208
209 name = parse_ref_line(refline, sha1);
210 if (name) {
211 list = add_ref(name, sha1, flag, list, &last);
212 continue;
213 }
214 if (last &&
215 refline[0] == '^' &&
216 strlen(refline) == 42 &&
217 refline[41] == '\n' &&
218 !get_sha1_hex(refline + 1, sha1))
219 hashcpy(last->peeled, sha1);
220 }
c774aab9 221 cached_refs->packed = sort_ref_list(list);
f4204ab9
JH
222}
223
e142a3c6
DB
224void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
225{
226 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
227}
228
229void clear_extra_refs(void)
230{
231 free_ref_list(extra_refs);
232 extra_refs = NULL;
233}
234
0bad611b 235static struct ref_list *get_packed_refs(const char *submodule)
5e290ff7 236{
0bad611b
HV
237 const char *packed_refs_file;
238 struct cached_refs *refs;
239
240 if (submodule) {
241 packed_refs_file = git_path_submodule(submodule, "packed-refs");
242 refs = &submodule_refs;
243 free_ref_list(refs->packed);
244 } else {
245 packed_refs_file = git_path("packed-refs");
246 refs = &cached_refs;
247 }
248
249 if (!refs->did_packed || submodule) {
250 FILE *f = fopen(packed_refs_file, "r");
251 refs->packed = NULL;
e1e22e37 252 if (f) {
0bad611b 253 read_packed_refs(f, refs);
e1e22e37 254 fclose(f);
e1e22e37 255 }
0bad611b 256 refs->did_packed = 1;
e1e22e37 257 }
0bad611b 258 return refs->packed;
e1e22e37
LT
259}
260
0bad611b
HV
261static struct ref_list *get_ref_dir(const char *submodule, const char *base,
262 struct ref_list *list)
e1e22e37 263{
0bad611b
HV
264 DIR *dir;
265 const char *path;
266
267 if (submodule)
268 path = git_path_submodule(submodule, "%s", base);
269 else
270 path = git_path("%s", base);
271
272
273 dir = opendir(path);
e1e22e37
LT
274
275 if (dir) {
276 struct dirent *de;
277 int baselen = strlen(base);
ed378ec7 278 char *ref = xmalloc(baselen + 257);
e1e22e37 279
ed378ec7 280 memcpy(ref, base, baselen);
e1e22e37 281 if (baselen && base[baselen-1] != '/')
ed378ec7 282 ref[baselen++] = '/';
e1e22e37
LT
283
284 while ((de = readdir(dir)) != NULL) {
285 unsigned char sha1[20];
286 struct stat st;
8da19775 287 int flag;
e1e22e37 288 int namelen;
0bad611b 289 const char *refdir;
e1e22e37
LT
290
291 if (de->d_name[0] == '.')
292 continue;
293 namelen = strlen(de->d_name);
294 if (namelen > 255)
295 continue;
296 if (has_extension(de->d_name, ".lock"))
297 continue;
ed378ec7 298 memcpy(ref + baselen, de->d_name, namelen+1);
0bad611b
HV
299 refdir = submodule
300 ? git_path_submodule(submodule, "%s", ref)
301 : git_path("%s", ref);
302 if (stat(refdir, &st) < 0)
e1e22e37
LT
303 continue;
304 if (S_ISDIR(st.st_mode)) {
0bad611b 305 list = get_ref_dir(submodule, ref, list);
e1e22e37
LT
306 continue;
307 }
0bad611b 308 if (submodule) {
f8948e2f 309 hashclr(sha1);
0bad611b
HV
310 flag = 0;
311 if (resolve_gitlink_ref(submodule, ref, sha1) < 0) {
312 hashclr(sha1);
313 flag |= REF_BROKEN;
314 }
315 } else
316 if (!resolve_ref(ref, sha1, 1, &flag)) {
317 hashclr(sha1);
318 flag |= REF_BROKEN;
319 }
f4204ab9 320 list = add_ref(ref, sha1, flag, list, NULL);
e1e22e37 321 }
ed378ec7 322 free(ref);
e1e22e37
LT
323 closedir(dir);
324 }
c774aab9 325 return sort_ref_list(list);
e1e22e37
LT
326}
327
f8948e2f 328struct warn_if_dangling_data {
3cf6134a 329 FILE *fp;
f8948e2f
JH
330 const char *refname;
331 const char *msg_fmt;
332};
333
334static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
335 int flags, void *cb_data)
336{
337 struct warn_if_dangling_data *d = cb_data;
338 const char *resolves_to;
339 unsigned char junk[20];
340
341 if (!(flags & REF_ISSYMREF))
342 return 0;
343
344 resolves_to = resolve_ref(refname, junk, 0, NULL);
345 if (!resolves_to || strcmp(resolves_to, d->refname))
346 return 0;
347
3cf6134a 348 fprintf(d->fp, d->msg_fmt, refname);
f8948e2f
JH
349 return 0;
350}
351
3cf6134a 352void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
f8948e2f 353{
66dbfd55
GV
354 struct warn_if_dangling_data data;
355
356 data.fp = fp;
357 data.refname = refname;
358 data.msg_fmt = msg_fmt;
f8948e2f
JH
359 for_each_rawref(warn_if_dangling_symref, &data);
360}
361
0bad611b 362static struct ref_list *get_loose_refs(const char *submodule)
e1e22e37 363{
0bad611b
HV
364 if (submodule) {
365 free_ref_list(submodule_refs.loose);
366 submodule_refs.loose = get_ref_dir(submodule, "refs", NULL);
367 return submodule_refs.loose;
368 }
369
5e290ff7 370 if (!cached_refs.did_loose) {
0bad611b 371 cached_refs.loose = get_ref_dir(NULL, "refs", NULL);
5e290ff7 372 cached_refs.did_loose = 1;
e1e22e37 373 }
5e290ff7 374 return cached_refs.loose;
e1e22e37
LT
375}
376
ca8db142
LT
377/* We allow "recursive" symbolic refs. Only within reason, though */
378#define MAXDEPTH 5
0ebde32c
LT
379#define MAXREFLEN (1024)
380
381static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
382{
383 FILE *f;
384 struct cached_refs refs;
385 struct ref_list *ref;
386 int retval;
387
388 strcpy(name + pathlen, "packed-refs");
389 f = fopen(name, "r");
390 if (!f)
391 return -1;
392 read_packed_refs(f, &refs);
393 fclose(f);
394 ref = refs.packed;
395 retval = -1;
396 while (ref) {
397 if (!strcmp(ref->name, refname)) {
398 retval = 0;
399 memcpy(result, ref->sha1, 20);
400 break;
401 }
402 ref = ref->next;
403 }
404 free_ref_list(refs.packed);
405 return retval;
406}
407
408static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
409{
410 int fd, len = strlen(refname);
411 char buffer[128], *p;
412
413 if (recursion > MAXDEPTH || len > MAXREFLEN)
414 return -1;
415 memcpy(name + pathlen, refname, len+1);
416 fd = open(name, O_RDONLY);
417 if (fd < 0)
418 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
419
420 len = read(fd, buffer, sizeof(buffer)-1);
421 close(fd);
422 if (len < 0)
423 return -1;
424 while (len && isspace(buffer[len-1]))
425 len--;
426 buffer[len] = 0;
427
428 /* Was it a detached head or an old-fashioned symlink? */
429 if (!get_sha1_hex(buffer, result))
430 return 0;
431
432 /* Symref? */
433 if (strncmp(buffer, "ref:", 4))
434 return -1;
435 p = buffer + 4;
436 while (isspace(*p))
437 p++;
438
439 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
440}
441
442int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
443{
444 int len = strlen(path), retval;
445 char *gitdir;
842abf06 446 const char *tmp;
0ebde32c
LT
447
448 while (len && path[len-1] == '/')
449 len--;
450 if (!len)
451 return -1;
452 gitdir = xmalloc(len + MAXREFLEN + 8);
453 memcpy(gitdir, path, len);
842abf06
LH
454 memcpy(gitdir + len, "/.git", 6);
455 len += 5;
456
457 tmp = read_gitfile_gently(gitdir);
458 if (tmp) {
459 free(gitdir);
460 len = strlen(tmp);
461 gitdir = xmalloc(len + MAXREFLEN + 3);
462 memcpy(gitdir, tmp, len);
463 }
464 gitdir[len] = '/';
465 gitdir[++len] = '\0';
466 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
0ebde32c
LT
467 free(gitdir);
468 return retval;
469}
ca8db142 470
4886b89f
CC
471/*
472 * If the "reading" argument is set, this function finds out what _object_
473 * the ref points at by "reading" the ref. The ref, if it is not symbolic,
474 * has to exist, and if it is symbolic, it has to point at an existing ref,
475 * because the "read" goes through the symref to the ref it points at.
476 *
477 * The access that is not "reading" may often be "writing", but does not
478 * have to; it can be merely checking _where it leads to_. If it is a
479 * prelude to "writing" to the ref, a write to a symref that points at
480 * yet-to-be-born ref will create the real ref pointed by the symref.
481 * reading=0 allows the caller to check where such a symref leads to.
482 */
8da19775 483const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
8a65ff76 484{
0104ca09
HO
485 int depth = MAXDEPTH;
486 ssize_t len;
a876ed83 487 char buffer[256];
ed378ec7 488 static char ref_buffer[256];
ca8db142 489
8da19775
JH
490 if (flag)
491 *flag = 0;
492
a876ed83 493 for (;;) {
958a4789 494 char path[PATH_MAX];
a876ed83
JH
495 struct stat st;
496 char *buf;
497 int fd;
8a65ff76 498
a876ed83
JH
499 if (--depth < 0)
500 return NULL;
ca8db142 501
958a4789 502 git_snpath(path, sizeof(path), "%s", ref);
4886b89f 503 /* Special case: non-existing file. */
a876ed83 504 if (lstat(path, &st) < 0) {
0bad611b 505 struct ref_list *list = get_packed_refs(NULL);
434cd0cd 506 while (list) {
f4204ab9 507 if (!strcmp(ref, list->name)) {
434cd0cd 508 hashcpy(sha1, list->sha1);
8da19775
JH
509 if (flag)
510 *flag |= REF_ISPACKED;
434cd0cd
LT
511 return ref;
512 }
513 list = list->next;
514 }
a876ed83
JH
515 if (reading || errno != ENOENT)
516 return NULL;
e702496e 517 hashclr(sha1);
ed378ec7 518 return ref;
a876ed83 519 }
ca8db142 520
a876ed83
JH
521 /* Follow "normalized" - ie "refs/.." symlinks by hand */
522 if (S_ISLNK(st.st_mode)) {
523 len = readlink(path, buffer, sizeof(buffer)-1);
524 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
ed378ec7
LT
525 buffer[len] = 0;
526 strcpy(ref_buffer, buffer);
527 ref = ref_buffer;
8da19775
JH
528 if (flag)
529 *flag |= REF_ISSYMREF;
a876ed83
JH
530 continue;
531 }
ca8db142 532 }
a876ed83 533
7a21632f
DS
534 /* Is it a directory? */
535 if (S_ISDIR(st.st_mode)) {
536 errno = EISDIR;
537 return NULL;
538 }
539
a876ed83
JH
540 /*
541 * Anything else, just open it and try to use it as
542 * a ref
543 */
544 fd = open(path, O_RDONLY);
545 if (fd < 0)
546 return NULL;
93d26e4c 547 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83
JH
548 close(fd);
549
550 /*
551 * Is it a symbolic ref?
552 */
553 if (len < 4 || memcmp("ref:", buffer, 4))
554 break;
555 buf = buffer + 4;
556 len -= 4;
557 while (len && isspace(*buf))
558 buf++, len--;
559 while (len && isspace(buf[len-1]))
ed378ec7
LT
560 len--;
561 buf[len] = 0;
562 memcpy(ref_buffer, buf, len + 1);
563 ref = ref_buffer;
8da19775
JH
564 if (flag)
565 *flag |= REF_ISSYMREF;
8a65ff76 566 }
a876ed83
JH
567 if (len < 40 || get_sha1_hex(buffer, sha1))
568 return NULL;
ed378ec7 569 return ref;
a876ed83
JH
570}
571
d08bae7e
IL
572/* The argument to filter_refs */
573struct ref_filter {
574 const char *pattern;
575 each_ref_fn *fn;
576 void *cb_data;
577};
578
ed378ec7 579int read_ref(const char *ref, unsigned char *sha1)
a876ed83 580{
8da19775 581 if (resolve_ref(ref, sha1, 1, NULL))
a876ed83
JH
582 return 0;
583 return -1;
8a65ff76
LT
584}
585
f8948e2f 586#define DO_FOR_EACH_INCLUDE_BROKEN 01
ef06b918 587static int do_one_ref(const char *base, each_ref_fn fn, int trim,
f8948e2f 588 int flags, void *cb_data, struct ref_list *entry)
ef06b918
JH
589{
590 if (strncmp(base, entry->name, trim))
591 return 0;
e01de1c9 592
f8948e2f 593 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
e01de1c9
JH
594 if (entry->flag & REF_BROKEN)
595 return 0; /* ignore dangling symref */
f8948e2f
JH
596 if (!has_sha1_file(entry->sha1)) {
597 error("%s does not point to a valid object!", entry->name);
598 return 0;
599 }
ef06b918 600 }
0ae91be0 601 current_ref = entry;
ef06b918
JH
602 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
603}
604
d08bae7e
IL
605static int filter_refs(const char *ref, const unsigned char *sha, int flags,
606 void *data)
607{
608 struct ref_filter *filter = (struct ref_filter *)data;
609 if (fnmatch(filter->pattern, ref, 0))
610 return 0;
611 return filter->fn(ref, sha, flags, filter->cb_data);
612}
613
cf0adba7
JH
614int peel_ref(const char *ref, unsigned char *sha1)
615{
616 int flag;
617 unsigned char base[20];
618 struct object *o;
619
0ae91be0
SP
620 if (current_ref && (current_ref->name == ref
621 || !strcmp(current_ref->name, ref))) {
622 if (current_ref->flag & REF_KNOWS_PEELED) {
623 hashcpy(sha1, current_ref->peeled);
624 return 0;
625 }
626 hashcpy(base, current_ref->sha1);
627 goto fallback;
628 }
629
cf0adba7
JH
630 if (!resolve_ref(ref, base, 1, &flag))
631 return -1;
632
633 if ((flag & REF_ISPACKED)) {
0bad611b 634 struct ref_list *list = get_packed_refs(NULL);
cf0adba7
JH
635
636 while (list) {
f4204ab9
JH
637 if (!strcmp(list->name, ref)) {
638 if (list->flag & REF_KNOWS_PEELED) {
639 hashcpy(sha1, list->peeled);
640 return 0;
641 }
642 /* older pack-refs did not leave peeled ones */
643 break;
cf0adba7
JH
644 }
645 list = list->next;
646 }
cf0adba7
JH
647 }
648
0ae91be0 649fallback:
cf0adba7 650 o = parse_object(base);
8c87dc77 651 if (o && o->type == OBJ_TAG) {
cf0adba7
JH
652 o = deref_tag(o, ref, 0);
653 if (o) {
654 hashcpy(sha1, o->sha1);
655 return 0;
656 }
657 }
658 return -1;
659}
660
0bad611b
HV
661static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
662 int trim, int flags, void *cb_data)
8a65ff76 663{
0ae91be0 664 int retval = 0;
0bad611b
HV
665 struct ref_list *packed = get_packed_refs(submodule);
666 struct ref_list *loose = get_loose_refs(submodule);
8a65ff76 667
e142a3c6
DB
668 struct ref_list *extra;
669
670 for (extra = extra_refs; extra; extra = extra->next)
f8948e2f 671 retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
e142a3c6 672
e1e22e37
LT
673 while (packed && loose) {
674 struct ref_list *entry;
675 int cmp = strcmp(packed->name, loose->name);
676 if (!cmp) {
677 packed = packed->next;
678 continue;
6cada6a9 679 }
e1e22e37
LT
680 if (cmp > 0) {
681 entry = loose;
682 loose = loose->next;
683 } else {
684 entry = packed;
685 packed = packed->next;
686 }
f8948e2f 687 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
e1e22e37 688 if (retval)
0ae91be0 689 goto end_each;
e1e22e37 690 }
8a65ff76 691
ef06b918 692 for (packed = packed ? packed : loose; packed; packed = packed->next) {
f8948e2f 693 retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
ef06b918 694 if (retval)
0ae91be0 695 goto end_each;
8a65ff76 696 }
0ae91be0
SP
697
698end_each:
699 current_ref = NULL;
700 return retval;
8a65ff76
LT
701}
702
0bad611b
HV
703
704static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
705{
706 unsigned char sha1[20];
8da19775
JH
707 int flag;
708
0bad611b
HV
709 if (submodule) {
710 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
711 return fn("HEAD", sha1, 0, cb_data);
712
713 return 0;
714 }
715
8da19775
JH
716 if (resolve_ref("HEAD", sha1, 1, &flag))
717 return fn("HEAD", sha1, flag, cb_data);
0bad611b 718
2f34ba32 719 return 0;
723c31fe
LT
720}
721
0bad611b
HV
722int head_ref(each_ref_fn fn, void *cb_data)
723{
724 return do_head_ref(NULL, fn, cb_data);
725}
726
9ef6aeb0
HV
727int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
728{
729 return do_head_ref(submodule, fn, cb_data);
730}
731
cb5d709f 732int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 733{
0bad611b 734 return do_for_each_ref(NULL, "refs/", fn, 0, 0, cb_data);
a62be77f
SE
735}
736
9ef6aeb0
HV
737int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
738{
739 return do_for_each_ref(submodule, "refs/", fn, 0, 0, cb_data);
a62be77f
SE
740}
741
2a8177b6
CC
742int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
743{
0bad611b 744 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
745}
746
9ef6aeb0
HV
747int for_each_ref_in_submodule(const char *submodule, const char *prefix,
748 each_ref_fn fn, void *cb_data)
749{
750 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
751}
752
cb5d709f 753int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 754{
2a8177b6 755 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
756}
757
9ef6aeb0
HV
758int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
759{
760 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
761}
762
cb5d709f 763int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 764{
2a8177b6 765 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
766}
767
9ef6aeb0
HV
768int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
769{
770 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
771}
772
cb5d709f 773int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 774{
2a8177b6 775 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
776}
777
9ef6aeb0
HV
778int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
779{
780 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
781}
782
29268700
CC
783int for_each_replace_ref(each_ref_fn fn, void *cb_data)
784{
0bad611b 785 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
786}
787
b09fe971
IL
788int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
789 const char *prefix, void *cb_data)
d08bae7e
IL
790{
791 struct strbuf real_pattern = STRBUF_INIT;
792 struct ref_filter filter;
d08bae7e
IL
793 int ret;
794
b09fe971 795 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 796 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
797 else if (prefix)
798 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
799 strbuf_addstr(&real_pattern, pattern);
800
894a9d33 801 if (!has_glob_specials(pattern)) {
9517e6b8 802 /* Append implied '/' '*' if not present. */
d08bae7e
IL
803 if (real_pattern.buf[real_pattern.len - 1] != '/')
804 strbuf_addch(&real_pattern, '/');
805 /* No need to check for '*', there is none. */
806 strbuf_addch(&real_pattern, '*');
807 }
808
809 filter.pattern = real_pattern.buf;
810 filter.fn = fn;
811 filter.cb_data = cb_data;
812 ret = for_each_ref(filter_refs, &filter);
813
814 strbuf_release(&real_pattern);
815 return ret;
816}
817
b09fe971
IL
818int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
819{
820 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
821}
822
f8948e2f
JH
823int for_each_rawref(each_ref_fn fn, void *cb_data)
824{
0bad611b 825 return do_for_each_ref(NULL, "refs/", fn, 0,
f8948e2f 826 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
827}
828
03feddd6
JH
829/*
830 * Make sure "ref" is something reasonable to have under ".git/refs/";
831 * We do not like it if:
832 *
833 * - any path component of it begins with ".", or
834 * - it has double dots "..", or
835 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
836 * - it ends with a "/".
3e262b95 837 * - it ends with ".lock"
a4c2e699 838 * - it contains a "\" (backslash)
03feddd6
JH
839 */
840
841static inline int bad_ref_char(int ch)
842{
8558fd9e 843 if (((unsigned) ch) <= ' ' ||
a4c2e699 844 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
8558fd9e
DB
845 return 1;
846 /* 2.13 Pattern Matching Notation */
847 if (ch == '?' || ch == '[') /* Unsupported */
848 return 1;
849 if (ch == '*') /* Supported at the end */
850 return 2;
851 return 0;
03feddd6
JH
852}
853
95fc7512
DB
854int check_ref_format(const char *ref)
855{
cbdffe40 856 int ch, level, bad_type, last;
abd2bde7 857 int ret = CHECK_REF_FORMAT_OK;
03feddd6
JH
858 const char *cp = ref;
859
860 level = 0;
861 while (1) {
862 while ((ch = *cp++) == '/')
863 ; /* tolerate duplicated slashes */
864 if (!ch)
5f7b202a
JH
865 /* should not end with slashes */
866 return CHECK_REF_FORMAT_ERROR;
03feddd6
JH
867
868 /* we are at the beginning of the path component */
8558fd9e 869 if (ch == '.')
5f7b202a 870 return CHECK_REF_FORMAT_ERROR;
8558fd9e
DB
871 bad_type = bad_ref_char(ch);
872 if (bad_type) {
abd2bde7
DB
873 if (bad_type == 2 && (!*cp || *cp == '/') &&
874 ret == CHECK_REF_FORMAT_OK)
875 ret = CHECK_REF_FORMAT_WILDCARD;
876 else
877 return CHECK_REF_FORMAT_ERROR;
8558fd9e 878 }
03feddd6 879
cbdffe40 880 last = ch;
03feddd6
JH
881 /* scan the rest of the path component */
882 while ((ch = *cp++) != 0) {
8558fd9e 883 bad_type = bad_ref_char(ch);
cbdffe40 884 if (bad_type)
08fbdb30 885 return CHECK_REF_FORMAT_ERROR;
03feddd6
JH
886 if (ch == '/')
887 break;
cbdffe40
JH
888 if (last == '.' && ch == '.')
889 return CHECK_REF_FORMAT_ERROR;
890 if (last == '@' && ch == '{')
5f7b202a 891 return CHECK_REF_FORMAT_ERROR;
cbdffe40 892 last = ch;
03feddd6
JH
893 }
894 level++;
895 if (!ch) {
cbdffe40
JH
896 if (ref <= cp - 2 && cp[-2] == '.')
897 return CHECK_REF_FORMAT_ERROR;
03feddd6 898 if (level < 2)
5f7b202a 899 return CHECK_REF_FORMAT_ONELEVEL;
3e262b95
SP
900 if (has_extension(ref, ".lock"))
901 return CHECK_REF_FORMAT_ERROR;
abd2bde7 902 return ret;
03feddd6
JH
903 }
904 }
95fc7512
DB
905}
906
4577e483 907const char *prettify_refname(const char *name)
a9c37a72 908{
a9c37a72
DB
909 return name + (
910 !prefixcmp(name, "refs/heads/") ? 11 :
911 !prefixcmp(name, "refs/tags/") ? 10 :
912 !prefixcmp(name, "refs/remotes/") ? 13 :
913 0);
914}
915
79803322
SP
916const char *ref_rev_parse_rules[] = {
917 "%.*s",
918 "refs/%.*s",
919 "refs/tags/%.*s",
920 "refs/heads/%.*s",
921 "refs/remotes/%.*s",
922 "refs/remotes/%.*s/HEAD",
923 NULL
924};
925
605b4978
SP
926const char *ref_fetch_rules[] = {
927 "%.*s",
928 "refs/%.*s",
929 "refs/heads/%.*s",
930 NULL
931};
932
79803322
SP
933int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
934{
935 const char **p;
936 const int abbrev_name_len = strlen(abbrev_name);
937
938 for (p = rules; *p; p++) {
939 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
940 return 1;
941 }
942 }
943
944 return 0;
945}
946
e5f38ec3 947static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
948 const unsigned char *old_sha1, int mustexist)
949{
8da19775 950 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 951 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
952 unlock_ref(lock);
953 return NULL;
954 }
a89fccd2 955 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 956 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
957 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
958 unlock_ref(lock);
959 return NULL;
960 }
961 return lock;
962}
963
7155b727 964static int remove_empty_directories(const char *file)
bc7127ef
JH
965{
966 /* we want to create a file but there is a directory there;
967 * if that is an empty directory (or a directory that contains
968 * only empty directories), remove them.
969 */
7155b727
JS
970 struct strbuf path;
971 int result;
bc7127ef 972
7155b727
JS
973 strbuf_init(&path, 20);
974 strbuf_addstr(&path, file);
975
a0f4afbe 976 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
977
978 strbuf_release(&path);
979
980 return result;
bc7127ef
JH
981}
982
c976d415
LH
983static int is_refname_available(const char *ref, const char *oldref,
984 struct ref_list *list, int quiet)
985{
986 int namlen = strlen(ref); /* e.g. 'foo/bar' */
987 while (list) {
988 /* list->name could be 'foo' or 'foo/bar/baz' */
989 if (!oldref || strcmp(oldref, list->name)) {
990 int len = strlen(list->name);
991 int cmplen = (namlen < len) ? namlen : len;
992 const char *lead = (namlen < len) ? list->name : ref;
993 if (!strncmp(ref, list->name, cmplen) &&
994 lead[cmplen] == '/') {
995 if (!quiet)
996 error("'%s' exists; cannot create '%s'",
997 list->name, ref);
998 return 0;
999 }
1000 }
1001 list = list->next;
1002 }
1003 return 1;
1004}
1005
68db31cc 1006static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
4bd18c43 1007{
434cd0cd 1008 char *ref_file;
ed378ec7 1009 const char *orig_ref = ref;
4bd18c43 1010 struct ref_lock *lock;
5cc3cef9 1011 int last_errno = 0;
acd3b9ec 1012 int type, lflags;
4431fcc4 1013 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1014 int missing = 0;
4bd18c43
SP
1015
1016 lock = xcalloc(1, sizeof(struct ref_lock));
1017 lock->lock_fd = -1;
1018
68db31cc 1019 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
bc7127ef
JH
1020 if (!ref && errno == EISDIR) {
1021 /* we are trying to lock foo but we used to
1022 * have foo/bar which now does not exist;
1023 * it is normal for the empty directory 'foo'
1024 * to remain.
1025 */
1026 ref_file = git_path("%s", orig_ref);
5cc3cef9
JH
1027 if (remove_empty_directories(ref_file)) {
1028 last_errno = errno;
1029 error("there are still refs under '%s'", orig_ref);
1030 goto error_return;
1031 }
68db31cc 1032 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
bc7127ef 1033 }
68db31cc
SV
1034 if (type_p)
1035 *type_p = type;
ed378ec7 1036 if (!ref) {
5cc3cef9 1037 last_errno = errno;
818f477c 1038 error("unable to resolve reference %s: %s",
ed378ec7 1039 orig_ref, strerror(errno));
5cc3cef9 1040 goto error_return;
4bd18c43 1041 }
5bdd8d4a 1042 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1043 /* When the ref did not exist and we are creating it,
1044 * make sure there is no existing ref that is packed
1045 * whose name begins with our refname, nor a ref whose
1046 * name is a proper prefix of our refname.
1047 */
5bdd8d4a 1048 if (missing &&
0bad611b 1049 !is_refname_available(ref, NULL, get_packed_refs(NULL), 0)) {
f475e08e 1050 last_errno = ENOTDIR;
c976d415 1051 goto error_return;
f475e08e 1052 }
22a3844e 1053
c33d5174 1054 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1055
acd3b9ec
JH
1056 lflags = LOCK_DIE_ON_ERROR;
1057 if (flags & REF_NODEREF) {
68db31cc 1058 ref = orig_ref;
acd3b9ec
JH
1059 lflags |= LOCK_NODEREF;
1060 }
434cd0cd 1061 lock->ref_name = xstrdup(ref);
1655707c 1062 lock->orig_ref_name = xstrdup(orig_ref);
7c1a278d 1063 ref_file = git_path("%s", ref);
5bdd8d4a 1064 if (missing)
68db31cc
SV
1065 lock->force_write = 1;
1066 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1067 lock->force_write = 1;
4bd18c43 1068
5cc3cef9
JH
1069 if (safe_create_leading_directories(ref_file)) {
1070 last_errno = errno;
1071 error("unable to create directory for %s", ref_file);
1072 goto error_return;
1073 }
4bd18c43 1074
acd3b9ec 1075 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1076 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1077
1078 error_return:
1079 unlock_ref(lock);
1080 errno = last_errno;
1081 return NULL;
4bd18c43
SP
1082}
1083
4431fcc4 1084struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
95fc7512 1085{
53cce84c 1086 char refpath[PATH_MAX];
95fc7512 1087 if (check_ref_format(ref))
4bd18c43 1088 return NULL;
53cce84c 1089 strcpy(refpath, mkpath("refs/%s", ref));
68db31cc 1090 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1091}
1092
68db31cc 1093struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
4bd18c43 1094{
5f7b202a 1095 switch (check_ref_format(ref)) {
5f7b202a 1096 default:
257f3020
JH
1097 return NULL;
1098 case 0:
1099 case CHECK_REF_FORMAT_ONELEVEL:
5f7b202a
JH
1100 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
1101 }
c0277d15
JH
1102}
1103
26a063a1
JH
1104static struct lock_file packlock;
1105
c0277d15
JH
1106static int repack_without_ref(const char *refname)
1107{
1108 struct ref_list *list, *packed_ref_list;
1109 int fd;
1110 int found = 0;
c0277d15 1111
0bad611b 1112 packed_ref_list = get_packed_refs(NULL);
c0277d15
JH
1113 for (list = packed_ref_list; list; list = list->next) {
1114 if (!strcmp(refname, list->name)) {
1115 found = 1;
1116 break;
1117 }
1118 }
1119 if (!found)
1120 return 0;
c0277d15 1121 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1b018fd9
MV
1122 if (fd < 0) {
1123 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 1124 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 1125 }
c0277d15
JH
1126
1127 for (list = packed_ref_list; list; list = list->next) {
1128 char line[PATH_MAX + 100];
1129 int len;
1130
1131 if (!strcmp(refname, list->name))
1132 continue;
1133 len = snprintf(line, sizeof(line), "%s %s\n",
1134 sha1_to_hex(list->sha1), list->name);
1135 /* this should not happen but just being defensive */
1136 if (len > sizeof(line))
1137 die("too long a refname '%s'", list->name);
1138 write_or_die(fd, line, len);
1139 }
1140 return commit_lock_file(&packlock);
1141}
1142
eca35a25 1143int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
1144{
1145 struct ref_lock *lock;
eca35a25 1146 int err, i = 0, ret = 0, flag = 0;
c0277d15 1147
68db31cc 1148 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
c0277d15
JH
1149 if (!lock)
1150 return 1;
045a476f 1151 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 1152 /* loose */
eca35a25
MV
1153 const char *path;
1154
1155 if (!(delopt & REF_NODEREF)) {
1156 i = strlen(lock->lk->filename) - 5; /* .lock */
1157 lock->lk->filename[i] = 0;
1158 path = lock->lk->filename;
1159 } else {
9db56f71 1160 path = git_path("%s", refname);
eca35a25 1161 }
691f1a28
AR
1162 err = unlink_or_warn(path);
1163 if (err && errno != ENOENT)
c0277d15 1164 ret = 1;
691f1a28 1165
eca35a25
MV
1166 if (!(delopt & REF_NODEREF))
1167 lock->lk->filename[i] = '.';
c0277d15
JH
1168 }
1169 /* removing the loose one could have resurrected an earlier
1170 * packed one. Also, if it was not loose we need to repack
1171 * without it.
1172 */
1173 ret |= repack_without_ref(refname);
1174
691f1a28 1175 unlink_or_warn(git_path("logs/%s", lock->ref_name));
c0277d15
JH
1176 invalidate_cached_refs();
1177 unlock_ref(lock);
1178 return ret;
4bd18c43
SP
1179}
1180
765c2258
PH
1181/*
1182 * People using contrib's git-new-workdir have .git/logs/refs ->
1183 * /some/other/path/.git/logs/refs, and that may live on another device.
1184 *
1185 * IOW, to avoid cross device rename errors, the temporary renamed log must
1186 * live into logs/refs.
1187 */
1188#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1189
678d0f4c 1190int rename_ref(const char *oldref, const char *newref, const char *logmsg)
c976d415
LH
1191{
1192 static const char renamed_ref[] = "RENAMED-REF";
1193 unsigned char sha1[20], orig_sha1[20];
1194 int flag = 0, logmoved = 0;
1195 struct ref_lock *lock;
c976d415 1196 struct stat loginfo;
16c2bfbb 1197 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
eca35a25 1198 const char *symref = NULL;
c976d415 1199
450d4c0f 1200 if (log && S_ISLNK(loginfo.st_mode))
c976d415
LH
1201 return error("reflog for %s is a symlink", oldref);
1202
eca35a25
MV
1203 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1204 if (flag & REF_ISSYMREF)
fa58186c
MV
1205 return error("refname %s is a symbolic ref, renaming it is not supported",
1206 oldref);
eca35a25 1207 if (!symref)
c976d415
LH
1208 return error("refname %s not found", oldref);
1209
0bad611b 1210 if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
c976d415
LH
1211 return 1;
1212
0bad611b 1213 if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
c976d415
LH
1214 return 1;
1215
68db31cc 1216 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
c976d415
LH
1217 if (!lock)
1218 return error("unable to lock %s", renamed_ref);
1219 lock->force_write = 1;
678d0f4c 1220 if (write_ref_sha1(lock, orig_sha1, logmsg))
c976d415
LH
1221 return error("unable to save current sha1 in %s", renamed_ref);
1222
765c2258
PH
1223 if (log && rename(git_path("logs/%s", oldref), git_path(TMP_RENAMED_LOG)))
1224 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
c976d415
LH
1225 oldref, strerror(errno));
1226
eca35a25 1227 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
c976d415
LH
1228 error("unable to delete old %s", oldref);
1229 goto rollback;
1230 }
1231
eca35a25 1232 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
c976d415
LH
1233 if (errno==EISDIR) {
1234 if (remove_empty_directories(git_path("%s", newref))) {
1235 error("Directory not empty: %s", newref);
1236 goto rollback;
1237 }
1238 } else {
1239 error("unable to delete existing %s", newref);
1240 goto rollback;
1241 }
1242 }
1243
1244 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1245 error("unable to create directory for %s", newref);
1246 goto rollback;
1247 }
1248
1249 retry:
765c2258 1250 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newref))) {
d9e74d57
JR
1251 if (errno==EISDIR || errno==ENOTDIR) {
1252 /*
1253 * rename(a, b) when b is an existing
1254 * directory ought to result in ISDIR, but
1255 * Solaris 5.8 gives ENOTDIR. Sheesh.
1256 */
c976d415
LH
1257 if (remove_empty_directories(git_path("logs/%s", newref))) {
1258 error("Directory not empty: logs/%s", newref);
1259 goto rollback;
1260 }
1261 goto retry;
1262 } else {
765c2258 1263 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
c976d415
LH
1264 newref, strerror(errno));
1265 goto rollback;
1266 }
1267 }
1268 logmoved = log;
1269
68db31cc 1270 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
c976d415
LH
1271 if (!lock) {
1272 error("unable to lock %s for update", newref);
1273 goto rollback;
1274 }
c976d415
LH
1275 lock->force_write = 1;
1276 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 1277 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
c976d415
LH
1278 error("unable to write current sha1 into %s", newref);
1279 goto rollback;
1280 }
1281
1282 return 0;
1283
1284 rollback:
68db31cc 1285 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
c976d415
LH
1286 if (!lock) {
1287 error("unable to lock %s for rollback", oldref);
1288 goto rollbacklog;
1289 }
1290
1291 lock->force_write = 1;
1292 flag = log_all_ref_updates;
1293 log_all_ref_updates = 0;
1294 if (write_ref_sha1(lock, orig_sha1, NULL))
1295 error("unable to write current sha1 into %s", oldref);
1296 log_all_ref_updates = flag;
1297
1298 rollbacklog:
1299 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1300 error("unable to restore logfile %s from %s: %s",
1301 oldref, newref, strerror(errno));
1302 if (!logmoved && log &&
765c2258
PH
1303 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldref)))
1304 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
c976d415
LH
1305 oldref, strerror(errno));
1306
1307 return 1;
1308}
1309
435fc852 1310int close_ref(struct ref_lock *lock)
b531394d
BC
1311{
1312 if (close_lock_file(lock->lk))
1313 return -1;
1314 lock->lock_fd = -1;
1315 return 0;
1316}
1317
435fc852 1318int commit_ref(struct ref_lock *lock)
b531394d
BC
1319{
1320 if (commit_lock_file(lock->lk))
1321 return -1;
1322 lock->lock_fd = -1;
1323 return 0;
1324}
1325
e5f38ec3 1326void unlock_ref(struct ref_lock *lock)
4bd18c43 1327{
4ed7cd3a
BC
1328 /* Do not free lock->lk -- atexit() still looks at them */
1329 if (lock->lk)
1330 rollback_lock_file(lock->lk);
434cd0cd 1331 free(lock->ref_name);
1655707c 1332 free(lock->orig_ref_name);
4bd18c43
SP
1333 free(lock);
1334}
1335
0ec29a47
JH
1336/*
1337 * copy the reflog message msg to buf, which has been allocated sufficiently
1338 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1339 * because reflog file is one line per entry.
1340 */
1341static int copy_msg(char *buf, const char *msg)
1342{
1343 char *cp = buf;
1344 char c;
1345 int wasspace = 1;
1346
1347 *cp++ = '\t';
1348 while ((c = *msg++)) {
1349 if (wasspace && isspace(c))
1350 continue;
1351 wasspace = isspace(c);
1352 if (wasspace)
1353 c = ' ';
1354 *cp++ = c;
1355 }
1356 while (buf < cp && isspace(cp[-1]))
1357 cp--;
1358 *cp++ = '\n';
1359 return cp - buf;
1360}
1361
157aaea5 1362int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
6de08ae6 1363{
859c3017 1364 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 1365
157aaea5 1366 git_snpath(logfile, bufsize, "logs/%s", ref_name);
4057deb5 1367 if (log_all_ref_updates &&
cc44c765
JH
1368 (!prefixcmp(ref_name, "refs/heads/") ||
1369 !prefixcmp(ref_name, "refs/remotes/") ||
b2e256b0 1370 !prefixcmp(ref_name, "refs/notes/") ||
bd104db1 1371 !strcmp(ref_name, "HEAD"))) {
157aaea5 1372 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 1373 return error("unable to create directory for %s",
157aaea5 1374 logfile);
6de08ae6
SP
1375 oflags |= O_CREAT;
1376 }
1377
157aaea5 1378 logfd = open(logfile, oflags, 0666);
6de08ae6 1379 if (logfd < 0) {
1974bf62 1380 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 1381 return 0;
3b463c3f
JH
1382
1383 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 1384 if (remove_empty_directories(logfile)) {
3b463c3f 1385 return error("There are still logs under '%s'",
157aaea5 1386 logfile);
3b463c3f 1387 }
157aaea5 1388 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
1389 }
1390
1391 if (logfd < 0)
1392 return error("Unable to append to %s: %s",
157aaea5 1393 logfile, strerror(errno));
6de08ae6
SP
1394 }
1395
157aaea5 1396 adjust_shared_perm(logfile);
859c3017
EM
1397 close(logfd);
1398 return 0;
1399}
443b92b6 1400
859c3017
EM
1401static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1402 const unsigned char *new_sha1, const char *msg)
1403{
1404 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1405 unsigned maxlen, len;
1406 int msglen;
157aaea5 1407 char log_file[PATH_MAX];
859c3017
EM
1408 char *logrec;
1409 const char *committer;
1410
1411 if (log_all_ref_updates < 0)
1412 log_all_ref_updates = !is_bare_repository();
1413
157aaea5 1414 result = log_ref_setup(ref_name, log_file, sizeof(log_file));
859c3017
EM
1415 if (result)
1416 return result;
1417
1418 logfd = open(log_file, oflags);
1419 if (logfd < 0)
1420 return 0;
0ec29a47 1421 msglen = msg ? strlen(msg) : 0;
774751a8 1422 committer = git_committer_info(0);
8ac65937
JH
1423 maxlen = strlen(committer) + msglen + 100;
1424 logrec = xmalloc(maxlen);
1425 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
1426 sha1_to_hex(old_sha1),
1427 sha1_to_hex(new_sha1),
8ac65937
JH
1428 committer);
1429 if (msglen)
0ec29a47 1430 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 1431 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 1432 free(logrec);
91c8d590 1433 if (close(logfd) != 0 || written != len)
9a13f0b7 1434 return error("Unable to append to %s", log_file);
6de08ae6
SP
1435 return 0;
1436}
1437
c3b0dec5
LT
1438static int is_branch(const char *refname)
1439{
1440 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1441}
1442
4bd18c43
SP
1443int write_ref_sha1(struct ref_lock *lock,
1444 const unsigned char *sha1, const char *logmsg)
1445{
1446 static char term = '\n';
c3b0dec5 1447 struct object *o;
4bd18c43
SP
1448
1449 if (!lock)
95fc7512 1450 return -1;
a89fccd2 1451 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
1452 unlock_ref(lock);
1453 return 0;
95fc7512 1454 }
c3b0dec5
LT
1455 o = parse_object(sha1);
1456 if (!o) {
7be8b3ba 1457 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
1458 lock->ref_name, sha1_to_hex(sha1));
1459 unlock_ref(lock);
1460 return -1;
1461 }
1462 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1463 error("Trying to write non-commit object %s to branch %s",
1464 sha1_to_hex(sha1), lock->ref_name);
1465 unlock_ref(lock);
1466 return -1;
1467 }
93822c22
AW
1468 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1469 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 1470 || close_ref(lock) < 0) {
c33d5174 1471 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
1472 unlock_ref(lock);
1473 return -1;
1474 }
5e290ff7 1475 invalidate_cached_refs();
bd104db1
NP
1476 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1477 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1478 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
1479 unlock_ref(lock);
1480 return -1;
1481 }
605fac8b
NP
1482 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1483 /*
1484 * Special hack: If a branch is updated directly and HEAD
1485 * points to it (may happen on the remote side of a push
1486 * for example) then logically the HEAD reflog should be
1487 * updated too.
1488 * A generic solution implies reverse symref information,
1489 * but finding all symrefs pointing to the given branch
1490 * would be rather costly for this rare event (the direct
1491 * update of a branch) to be worth it. So let's cheat and
1492 * check with HEAD only which should cover 99% of all usage
1493 * scenarios (even 100% of the default ones).
1494 */
1495 unsigned char head_sha1[20];
1496 int head_flag;
1497 const char *head_ref;
1498 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1499 if (head_ref && (head_flag & REF_ISSYMREF) &&
1500 !strcmp(head_ref, lock->ref_name))
1501 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1502 }
b531394d 1503 if (commit_ref(lock)) {
434cd0cd 1504 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
1505 unlock_ref(lock);
1506 return -1;
1507 }
4bd18c43
SP
1508 unlock_ref(lock);
1509 return 0;
95fc7512 1510}
d556fae2 1511
8b5157e4
NP
1512int create_symref(const char *ref_target, const char *refs_heads_master,
1513 const char *logmsg)
41b625b0
NP
1514{
1515 const char *lockpath;
1516 char ref[1000];
1517 int fd, len, written;
a4f34cbb 1518 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
1519 unsigned char old_sha1[20], new_sha1[20];
1520
1521 if (logmsg && read_ref(ref_target, old_sha1))
1522 hashclr(old_sha1);
41b625b0 1523
d48744d1
JH
1524 if (safe_create_leading_directories(git_HEAD) < 0)
1525 return error("unable to create directory for %s", git_HEAD);
1526
41b625b0
NP
1527#ifndef NO_SYMLINK_HEAD
1528 if (prefer_symlink_refs) {
1529 unlink(git_HEAD);
1530 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 1531 goto done;
41b625b0
NP
1532 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1533 }
1534#endif
1535
1536 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1537 if (sizeof(ref) <= len) {
1538 error("refname too long: %s", refs_heads_master);
47fc52e2 1539 goto error_free_return;
41b625b0
NP
1540 }
1541 lockpath = mkpath("%s.lock", git_HEAD);
1542 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1543 if (fd < 0) {
1544 error("Unable to open %s for writing", lockpath);
47fc52e2 1545 goto error_free_return;
41b625b0
NP
1546 }
1547 written = write_in_full(fd, ref, len);
91c8d590 1548 if (close(fd) != 0 || written != len) {
41b625b0 1549 error("Unable to write to %s", lockpath);
47fc52e2 1550 goto error_unlink_return;
41b625b0
NP
1551 }
1552 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 1553 error("Unable to create %s", git_HEAD);
47fc52e2 1554 goto error_unlink_return;
41b625b0
NP
1555 }
1556 if (adjust_shared_perm(git_HEAD)) {
41b625b0 1557 error("Unable to fix permissions on %s", lockpath);
47fc52e2 1558 error_unlink_return:
691f1a28 1559 unlink_or_warn(lockpath);
47fc52e2
JH
1560 error_free_return:
1561 free(git_HEAD);
1562 return -1;
41b625b0 1563 }
8b5157e4 1564
ee96d11b 1565#ifndef NO_SYMLINK_HEAD
8b5157e4 1566 done:
ee96d11b 1567#endif
8b5157e4
NP
1568 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1569 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1570
47fc52e2 1571 free(git_HEAD);
41b625b0
NP
1572 return 0;
1573}
1574
16d7cc90
JH
1575static char *ref_msg(const char *line, const char *endp)
1576{
1577 const char *ep;
16d7cc90 1578 line += 82;
182af834
PH
1579 ep = memchr(line, '\n', endp - line);
1580 if (!ep)
1581 ep = endp;
1582 return xmemdupz(line, ep - line);
16d7cc90
JH
1583}
1584
1585int 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)
d556fae2 1586{
e5229042 1587 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 1588 char *tz_c;
e29cb53a 1589 int logfd, tz, reccnt = 0;
d556fae2
SP
1590 struct stat st;
1591 unsigned long date;
e5229042 1592 unsigned char logged_sha1[20];
cb48cb58 1593 void *log_mapped;
dc49cd76 1594 size_t mapsz;
d556fae2
SP
1595
1596 logfile = git_path("logs/%s", ref);
1597 logfd = open(logfile, O_RDONLY, 0);
1598 if (logfd < 0)
d824cbba 1599 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
1600 fstat(logfd, &st);
1601 if (!st.st_size)
1602 die("Log %s is empty.", logfile);
dc49cd76
SP
1603 mapsz = xsize_t(st.st_size);
1604 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 1605 logdata = log_mapped;
d556fae2
SP
1606 close(logfd);
1607
e5229042 1608 lastrec = NULL;
d556fae2
SP
1609 rec = logend = logdata + st.st_size;
1610 while (logdata < rec) {
e29cb53a 1611 reccnt++;
d556fae2
SP
1612 if (logdata < rec && *(rec-1) == '\n')
1613 rec--;
e5229042
SP
1614 lastgt = NULL;
1615 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 1616 rec--;
e5229042
SP
1617 if (*rec == '>')
1618 lastgt = rec;
1619 }
1620 if (!lastgt)
d556fae2 1621 die("Log %s is corrupt.", logfile);
e5229042 1622 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 1623 if (date <= at_time || cnt == 0) {
76a44c5c 1624 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
1625 if (msg)
1626 *msg = ref_msg(rec, logend);
1627 if (cutoff_time)
1628 *cutoff_time = date;
1629 if (cutoff_tz)
1630 *cutoff_tz = tz;
1631 if (cutoff_cnt)
76a44c5c 1632 *cutoff_cnt = reccnt - 1;
e5229042
SP
1633 if (lastrec) {
1634 if (get_sha1_hex(lastrec, logged_sha1))
1635 die("Log %s is corrupt.", logfile);
1636 if (get_sha1_hex(rec + 41, sha1))
1637 die("Log %s is corrupt.", logfile);
a89fccd2 1638 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1639 warning("Log %s has gap after %s.",
73013afd 1640 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 1641 }
e5f38ec3
JH
1642 }
1643 else if (date == at_time) {
e5229042
SP
1644 if (get_sha1_hex(rec + 41, sha1))
1645 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
1646 }
1647 else {
e5229042
SP
1648 if (get_sha1_hex(rec + 41, logged_sha1))
1649 die("Log %s is corrupt.", logfile);
a89fccd2 1650 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1651 warning("Log %s unexpectedly ended on %s.",
73013afd 1652 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
1653 }
1654 }
dc49cd76 1655 munmap(log_mapped, mapsz);
d556fae2
SP
1656 return 0;
1657 }
e5229042 1658 lastrec = rec;
ab2a1a32
JH
1659 if (cnt > 0)
1660 cnt--;
d556fae2
SP
1661 }
1662
e5229042
SP
1663 rec = logdata;
1664 while (rec < logend && *rec != '>' && *rec != '\n')
1665 rec++;
1666 if (rec == logend || *rec == '\n')
d556fae2 1667 die("Log %s is corrupt.", logfile);
e5229042 1668 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
1669 tz = strtoul(tz_c, NULL, 10);
1670 if (get_sha1_hex(logdata, sha1))
1671 die("Log %s is corrupt.", logfile);
d1a4489a
JK
1672 if (is_null_sha1(sha1)) {
1673 if (get_sha1_hex(logdata + 41, sha1))
1674 die("Log %s is corrupt.", logfile);
1675 }
16d7cc90
JH
1676 if (msg)
1677 *msg = ref_msg(logdata, logend);
dc49cd76 1678 munmap(log_mapped, mapsz);
16d7cc90
JH
1679
1680 if (cutoff_time)
1681 *cutoff_time = date;
1682 if (cutoff_tz)
1683 *cutoff_tz = tz;
1684 if (cutoff_cnt)
1685 *cutoff_cnt = reccnt;
1686 return 1;
d556fae2 1687}
2ff81662 1688
101d15e0 1689int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
1690{
1691 const char *logfile;
1692 FILE *logfp;
8ca78803 1693 struct strbuf sb = STRBUF_INIT;
2266bf27 1694 int ret = 0;
2ff81662
JH
1695
1696 logfile = git_path("logs/%s", ref);
1697 logfp = fopen(logfile, "r");
1698 if (!logfp)
883d60fa 1699 return -1;
101d15e0
JH
1700
1701 if (ofs) {
1702 struct stat statbuf;
1703 if (fstat(fileno(logfp), &statbuf) ||
1704 statbuf.st_size < ofs ||
1705 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 1706 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 1707 fclose(logfp);
8ca78803 1708 strbuf_release(&sb);
101d15e0 1709 return -1;
9d33f7c2 1710 }
101d15e0
JH
1711 }
1712
8ca78803 1713 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 1714 unsigned char osha1[20], nsha1[20];
883d60fa
JS
1715 char *email_end, *message;
1716 unsigned long timestamp;
8ca78803 1717 int tz;
2ff81662
JH
1718
1719 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
1720 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
1721 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
1722 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
1723 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
1724 email_end[1] != ' ' ||
1725 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1726 !message || message[0] != ' ' ||
1727 (message[1] != '+' && message[1] != '-') ||
1728 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 1729 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 1730 continue; /* corrupt? */
883d60fa
JS
1731 email_end[1] = '\0';
1732 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
1733 if (message[6] != '\t')
1734 message += 6;
1735 else
1736 message += 7;
8ca78803
RS
1737 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
1738 cb_data);
883d60fa 1739 if (ret)
2266bf27 1740 break;
2ff81662
JH
1741 }
1742 fclose(logfp);
8ca78803 1743 strbuf_release(&sb);
2266bf27 1744 return ret;
2ff81662 1745}
e29cb53a 1746
101d15e0
JH
1747int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1748{
1749 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1750}
1751
eb8381c8
NP
1752static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1753{
1754 DIR *dir = opendir(git_path("logs/%s", base));
fcee5a14 1755 int retval = 0;
eb8381c8
NP
1756
1757 if (dir) {
1758 struct dirent *de;
1759 int baselen = strlen(base);
1760 char *log = xmalloc(baselen + 257);
1761
1762 memcpy(log, base, baselen);
1763 if (baselen && base[baselen-1] != '/')
1764 log[baselen++] = '/';
1765
1766 while ((de = readdir(dir)) != NULL) {
1767 struct stat st;
1768 int namelen;
1769
1770 if (de->d_name[0] == '.')
1771 continue;
1772 namelen = strlen(de->d_name);
1773 if (namelen > 255)
1774 continue;
1775 if (has_extension(de->d_name, ".lock"))
1776 continue;
1777 memcpy(log + baselen, de->d_name, namelen+1);
1778 if (stat(git_path("logs/%s", log), &st) < 0)
1779 continue;
1780 if (S_ISDIR(st.st_mode)) {
1781 retval = do_for_each_reflog(log, fn, cb_data);
1782 } else {
1783 unsigned char sha1[20];
1784 if (!resolve_ref(log, sha1, 0, NULL))
1785 retval = error("bad ref for %s", log);
1786 else
1787 retval = fn(log, sha1, 0, cb_data);
1788 }
1789 if (retval)
1790 break;
1791 }
1792 free(log);
1793 closedir(dir);
1794 }
acb39f64 1795 else if (*base)
fcee5a14 1796 return errno;
eb8381c8
NP
1797 return retval;
1798}
1799
1800int for_each_reflog(each_ref_fn fn, void *cb_data)
1801{
1802 return do_for_each_reflog("", fn, cb_data);
1803}
3d9f037c
CR
1804
1805int update_ref(const char *action, const char *refname,
1806 const unsigned char *sha1, const unsigned char *oldval,
1807 int flags, enum action_on_err onerr)
1808{
1809 static struct ref_lock *lock;
1810 lock = lock_any_ref_for_update(refname, oldval, flags);
1811 if (!lock) {
1812 const char *str = "Cannot lock the ref '%s'.";
1813 switch (onerr) {
1814 case MSG_ON_ERR: error(str, refname); break;
1815 case DIE_ON_ERR: die(str, refname); break;
1816 case QUIET_ON_ERR: break;
1817 }
1818 return 1;
1819 }
1820 if (write_ref_sha1(lock, sha1, action) < 0) {
1821 const char *str = "Cannot update the ref '%s'.";
1822 switch (onerr) {
1823 case MSG_ON_ERR: error(str, refname); break;
1824 case DIE_ON_ERR: die(str, refname); break;
1825 case QUIET_ON_ERR: break;
1826 }
1827 return 1;
1828 }
1829 return 0;
1830}
cda69f48 1831
c17b2294
JH
1832int ref_exists(char *refname)
1833{
1834 unsigned char sha1[20];
1835 return !!resolve_ref(refname, sha1, 1, NULL);
1836}
1837
5483f799 1838struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
1839{
1840 for ( ; list; list = list->next)
1841 if (!strcmp(list->name, name))
5483f799 1842 return (struct ref *)list;
cda69f48
JK
1843 return NULL;
1844}
7c2b3029
JK
1845
1846/*
1847 * generate a format suitable for scanf from a ref_rev_parse_rules
1848 * rule, that is replace the "%.*s" spec with a "%s" spec
1849 */
1850static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1851{
1852 char *spec;
1853
1854 spec = strstr(rule, "%.*s");
1855 if (!spec || strstr(spec + 4, "%.*s"))
1856 die("invalid rule in ref_rev_parse_rules: %s", rule);
1857
1858 /* copy all until spec */
1859 strncpy(scanf_fmt, rule, spec - rule);
1860 scanf_fmt[spec - rule] = '\0';
1861 /* copy new spec */
1862 strcat(scanf_fmt, "%s");
1863 /* copy remaining rule */
1864 strcat(scanf_fmt, spec + 4);
1865
1866 return;
1867}
1868
6e7b3309 1869char *shorten_unambiguous_ref(const char *ref, int strict)
7c2b3029
JK
1870{
1871 int i;
1872 static char **scanf_fmts;
1873 static int nr_rules;
1874 char *short_name;
1875
1876 /* pre generate scanf formats from ref_rev_parse_rules[] */
1877 if (!nr_rules) {
1878 size_t total_len = 0;
1879
1880 /* the rule list is NULL terminated, count them first */
1881 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
1882 /* no +1 because strlen("%s") < strlen("%.*s") */
1883 total_len += strlen(ref_rev_parse_rules[nr_rules]);
1884
1885 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
1886
1887 total_len = 0;
1888 for (i = 0; i < nr_rules; i++) {
1889 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
1890 + total_len;
1891 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
1892 total_len += strlen(ref_rev_parse_rules[i]);
1893 }
1894 }
1895
1896 /* bail out if there are no rules */
1897 if (!nr_rules)
1898 return xstrdup(ref);
1899
1900 /* buffer for scanf result, at most ref must fit */
1901 short_name = xstrdup(ref);
1902
1903 /* skip first rule, it will always match */
1904 for (i = nr_rules - 1; i > 0 ; --i) {
1905 int j;
6e7b3309 1906 int rules_to_fail = i;
7c2b3029
JK
1907 int short_name_len;
1908
1909 if (1 != sscanf(ref, scanf_fmts[i], short_name))
1910 continue;
1911
1912 short_name_len = strlen(short_name);
1913
6e7b3309
BW
1914 /*
1915 * in strict mode, all (except the matched one) rules
1916 * must fail to resolve to a valid non-ambiguous ref
1917 */
1918 if (strict)
1919 rules_to_fail = nr_rules;
1920
7c2b3029
JK
1921 /*
1922 * check if the short name resolves to a valid ref,
1923 * but use only rules prior to the matched one
1924 */
6e7b3309 1925 for (j = 0; j < rules_to_fail; j++) {
7c2b3029
JK
1926 const char *rule = ref_rev_parse_rules[j];
1927 unsigned char short_objectname[20];
1928 char refname[PATH_MAX];
1929
6e7b3309
BW
1930 /* skip matched rule */
1931 if (i == j)
1932 continue;
1933
7c2b3029
JK
1934 /*
1935 * the short name is ambiguous, if it resolves
1936 * (with this previous rule) to a valid ref
1937 * read_ref() returns 0 on success
1938 */
1939 mksnpath(refname, sizeof(refname),
1940 rule, short_name_len, short_name);
1941 if (!read_ref(refname, short_objectname))
1942 break;
1943 }
1944
1945 /*
1946 * short name is non-ambiguous if all previous rules
1947 * haven't resolved to a valid ref
1948 */
6e7b3309 1949 if (j == rules_to_fail)
7c2b3029
JK
1950 return short_name;
1951 }
1952
1953 free(short_name);
1954 return xstrdup(ref);
1955}