Change the signature of read_packed_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
4349a668
MH
184/*
185 * Return a pointer to a cached_refs for the specified submodule. For
186 * the main repository, use submodule==NULL. The returned structure
187 * will be allocated and initialized but not necessarily populated; it
188 * should not be freed.
189 */
190static struct cached_refs *get_cached_refs(const char *submodule)
191{
192 if (!submodule)
193 return &cached_refs;
194 else {
195 /* For now, don't reuse the refs cache for submodules. */
196 clear_cached_refs(&submodule_refs);
197 return &submodule_refs;
198 }
199}
200
f130b116
MH
201static void invalidate_cached_refs(void)
202{
4349a668 203 clear_cached_refs(get_cached_refs(NULL));
5e290ff7 204}
e1e22e37 205
db4dd93a 206static struct ref_list *read_packed_refs(FILE *f)
f4204ab9
JH
207{
208 struct ref_list *list = NULL;
209 struct ref_list *last = NULL;
210 char refline[PATH_MAX];
211 int flag = REF_ISPACKED;
212
213 while (fgets(refline, sizeof(refline), f)) {
214 unsigned char sha1[20];
215 const char *name;
216 static const char header[] = "# pack-refs with:";
217
218 if (!strncmp(refline, header, sizeof(header)-1)) {
219 const char *traits = refline + sizeof(header) - 1;
220 if (strstr(traits, " peeled "))
221 flag |= REF_KNOWS_PEELED;
222 /* perhaps other traits later as well */
223 continue;
224 }
225
226 name = parse_ref_line(refline, sha1);
227 if (name) {
228 list = add_ref(name, sha1, flag, list, &last);
229 continue;
230 }
231 if (last &&
232 refline[0] == '^' &&
233 strlen(refline) == 42 &&
234 refline[41] == '\n' &&
235 !get_sha1_hex(refline + 1, sha1))
236 hashcpy(last->peeled, sha1);
237 }
db4dd93a 238 return sort_ref_list(list);
f4204ab9
JH
239}
240
e142a3c6
DB
241void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
242{
243 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
244}
245
246void clear_extra_refs(void)
247{
248 free_ref_list(extra_refs);
249 extra_refs = NULL;
250}
251
0bad611b 252static struct ref_list *get_packed_refs(const char *submodule)
5e290ff7 253{
4349a668 254 struct cached_refs *refs = get_cached_refs(submodule);
0bad611b 255
4349a668
MH
256 if (!refs->did_packed) {
257 const char *packed_refs_file;
258 FILE *f;
259
260 if (submodule)
261 packed_refs_file = git_path_submodule(submodule, "packed-refs");
262 else
263 packed_refs_file = git_path("packed-refs");
264 f = fopen(packed_refs_file, "r");
0bad611b 265 refs->packed = NULL;
e1e22e37 266 if (f) {
db4dd93a 267 refs->packed = read_packed_refs(f);
e1e22e37 268 fclose(f);
e1e22e37 269 }
0bad611b 270 refs->did_packed = 1;
e1e22e37 271 }
0bad611b 272 return refs->packed;
e1e22e37
LT
273}
274
0bad611b
HV
275static struct ref_list *get_ref_dir(const char *submodule, const char *base,
276 struct ref_list *list)
e1e22e37 277{
0bad611b
HV
278 DIR *dir;
279 const char *path;
280
281 if (submodule)
282 path = git_path_submodule(submodule, "%s", base);
283 else
284 path = git_path("%s", base);
285
286
287 dir = opendir(path);
e1e22e37
LT
288
289 if (dir) {
290 struct dirent *de;
291 int baselen = strlen(base);
ed378ec7 292 char *ref = xmalloc(baselen + 257);
e1e22e37 293
ed378ec7 294 memcpy(ref, base, baselen);
e1e22e37 295 if (baselen && base[baselen-1] != '/')
ed378ec7 296 ref[baselen++] = '/';
e1e22e37
LT
297
298 while ((de = readdir(dir)) != NULL) {
299 unsigned char sha1[20];
300 struct stat st;
8da19775 301 int flag;
e1e22e37 302 int namelen;
0bad611b 303 const char *refdir;
e1e22e37
LT
304
305 if (de->d_name[0] == '.')
306 continue;
307 namelen = strlen(de->d_name);
308 if (namelen > 255)
309 continue;
310 if (has_extension(de->d_name, ".lock"))
311 continue;
ed378ec7 312 memcpy(ref + baselen, de->d_name, namelen+1);
0bad611b
HV
313 refdir = submodule
314 ? git_path_submodule(submodule, "%s", ref)
315 : git_path("%s", ref);
316 if (stat(refdir, &st) < 0)
e1e22e37
LT
317 continue;
318 if (S_ISDIR(st.st_mode)) {
0bad611b 319 list = get_ref_dir(submodule, ref, list);
e1e22e37
LT
320 continue;
321 }
0bad611b 322 if (submodule) {
f8948e2f 323 hashclr(sha1);
0bad611b
HV
324 flag = 0;
325 if (resolve_gitlink_ref(submodule, ref, sha1) < 0) {
326 hashclr(sha1);
327 flag |= REF_BROKEN;
328 }
329 } else
330 if (!resolve_ref(ref, sha1, 1, &flag)) {
331 hashclr(sha1);
332 flag |= REF_BROKEN;
333 }
f4204ab9 334 list = add_ref(ref, sha1, flag, list, NULL);
e1e22e37 335 }
ed378ec7 336 free(ref);
e1e22e37
LT
337 closedir(dir);
338 }
c774aab9 339 return sort_ref_list(list);
e1e22e37
LT
340}
341
f8948e2f 342struct warn_if_dangling_data {
3cf6134a 343 FILE *fp;
f8948e2f
JH
344 const char *refname;
345 const char *msg_fmt;
346};
347
348static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
349 int flags, void *cb_data)
350{
351 struct warn_if_dangling_data *d = cb_data;
352 const char *resolves_to;
353 unsigned char junk[20];
354
355 if (!(flags & REF_ISSYMREF))
356 return 0;
357
358 resolves_to = resolve_ref(refname, junk, 0, NULL);
359 if (!resolves_to || strcmp(resolves_to, d->refname))
360 return 0;
361
3cf6134a 362 fprintf(d->fp, d->msg_fmt, refname);
f8948e2f
JH
363 return 0;
364}
365
3cf6134a 366void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
f8948e2f 367{
66dbfd55
GV
368 struct warn_if_dangling_data data;
369
370 data.fp = fp;
371 data.refname = refname;
372 data.msg_fmt = msg_fmt;
f8948e2f
JH
373 for_each_rawref(warn_if_dangling_symref, &data);
374}
375
0bad611b 376static struct ref_list *get_loose_refs(const char *submodule)
e1e22e37 377{
4349a668 378 struct cached_refs *refs = get_cached_refs(submodule);
0bad611b 379
4349a668
MH
380 if (!refs->did_loose) {
381 refs->loose = get_ref_dir(submodule, "refs", NULL);
382 refs->did_loose = 1;
e1e22e37 383 }
4349a668 384 return refs->loose;
e1e22e37
LT
385}
386
ca8db142
LT
387/* We allow "recursive" symbolic refs. Only within reason, though */
388#define MAXDEPTH 5
0ebde32c
LT
389#define MAXREFLEN (1024)
390
391static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
392{
393 FILE *f;
db4dd93a 394 struct ref_list *packed_refs;
0ebde32c
LT
395 struct ref_list *ref;
396 int retval;
397
398 strcpy(name + pathlen, "packed-refs");
399 f = fopen(name, "r");
400 if (!f)
401 return -1;
db4dd93a 402 packed_refs = read_packed_refs(f);
0ebde32c 403 fclose(f);
db4dd93a 404 ref = packed_refs;
0ebde32c
LT
405 retval = -1;
406 while (ref) {
407 if (!strcmp(ref->name, refname)) {
408 retval = 0;
409 memcpy(result, ref->sha1, 20);
410 break;
411 }
412 ref = ref->next;
413 }
db4dd93a 414 free_ref_list(packed_refs);
0ebde32c
LT
415 return retval;
416}
417
418static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
419{
420 int fd, len = strlen(refname);
421 char buffer[128], *p;
422
423 if (recursion > MAXDEPTH || len > MAXREFLEN)
424 return -1;
425 memcpy(name + pathlen, refname, len+1);
426 fd = open(name, O_RDONLY);
427 if (fd < 0)
428 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
429
430 len = read(fd, buffer, sizeof(buffer)-1);
431 close(fd);
432 if (len < 0)
433 return -1;
434 while (len && isspace(buffer[len-1]))
435 len--;
436 buffer[len] = 0;
437
438 /* Was it a detached head or an old-fashioned symlink? */
439 if (!get_sha1_hex(buffer, result))
440 return 0;
441
442 /* Symref? */
443 if (strncmp(buffer, "ref:", 4))
444 return -1;
445 p = buffer + 4;
446 while (isspace(*p))
447 p++;
448
449 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
450}
451
452int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
453{
454 int len = strlen(path), retval;
455 char *gitdir;
842abf06 456 const char *tmp;
0ebde32c
LT
457
458 while (len && path[len-1] == '/')
459 len--;
460 if (!len)
461 return -1;
462 gitdir = xmalloc(len + MAXREFLEN + 8);
463 memcpy(gitdir, path, len);
842abf06
LH
464 memcpy(gitdir + len, "/.git", 6);
465 len += 5;
466
467 tmp = read_gitfile_gently(gitdir);
468 if (tmp) {
469 free(gitdir);
470 len = strlen(tmp);
471 gitdir = xmalloc(len + MAXREFLEN + 3);
472 memcpy(gitdir, tmp, len);
473 }
474 gitdir[len] = '/';
475 gitdir[++len] = '\0';
476 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
0ebde32c
LT
477 free(gitdir);
478 return retval;
479}
ca8db142 480
4886b89f
CC
481/*
482 * If the "reading" argument is set, this function finds out what _object_
483 * the ref points at by "reading" the ref. The ref, if it is not symbolic,
484 * has to exist, and if it is symbolic, it has to point at an existing ref,
485 * because the "read" goes through the symref to the ref it points at.
486 *
487 * The access that is not "reading" may often be "writing", but does not
488 * have to; it can be merely checking _where it leads to_. If it is a
489 * prelude to "writing" to the ref, a write to a symref that points at
490 * yet-to-be-born ref will create the real ref pointed by the symref.
491 * reading=0 allows the caller to check where such a symref leads to.
492 */
8da19775 493const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
8a65ff76 494{
0104ca09
HO
495 int depth = MAXDEPTH;
496 ssize_t len;
a876ed83 497 char buffer[256];
ed378ec7 498 static char ref_buffer[256];
ca8db142 499
8da19775
JH
500 if (flag)
501 *flag = 0;
502
a876ed83 503 for (;;) {
958a4789 504 char path[PATH_MAX];
a876ed83
JH
505 struct stat st;
506 char *buf;
507 int fd;
8a65ff76 508
a876ed83
JH
509 if (--depth < 0)
510 return NULL;
ca8db142 511
958a4789 512 git_snpath(path, sizeof(path), "%s", ref);
4886b89f 513 /* Special case: non-existing file. */
a876ed83 514 if (lstat(path, &st) < 0) {
0bad611b 515 struct ref_list *list = get_packed_refs(NULL);
434cd0cd 516 while (list) {
f4204ab9 517 if (!strcmp(ref, list->name)) {
434cd0cd 518 hashcpy(sha1, list->sha1);
8da19775
JH
519 if (flag)
520 *flag |= REF_ISPACKED;
434cd0cd
LT
521 return ref;
522 }
523 list = list->next;
524 }
a876ed83
JH
525 if (reading || errno != ENOENT)
526 return NULL;
e702496e 527 hashclr(sha1);
ed378ec7 528 return ref;
a876ed83 529 }
ca8db142 530
a876ed83
JH
531 /* Follow "normalized" - ie "refs/.." symlinks by hand */
532 if (S_ISLNK(st.st_mode)) {
533 len = readlink(path, buffer, sizeof(buffer)-1);
534 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
ed378ec7
LT
535 buffer[len] = 0;
536 strcpy(ref_buffer, buffer);
537 ref = ref_buffer;
8da19775
JH
538 if (flag)
539 *flag |= REF_ISSYMREF;
a876ed83
JH
540 continue;
541 }
ca8db142 542 }
a876ed83 543
7a21632f
DS
544 /* Is it a directory? */
545 if (S_ISDIR(st.st_mode)) {
546 errno = EISDIR;
547 return NULL;
548 }
549
a876ed83
JH
550 /*
551 * Anything else, just open it and try to use it as
552 * a ref
553 */
554 fd = open(path, O_RDONLY);
555 if (fd < 0)
556 return NULL;
93d26e4c 557 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83
JH
558 close(fd);
559
560 /*
561 * Is it a symbolic ref?
562 */
563 if (len < 4 || memcmp("ref:", buffer, 4))
564 break;
565 buf = buffer + 4;
566 len -= 4;
567 while (len && isspace(*buf))
568 buf++, len--;
569 while (len && isspace(buf[len-1]))
ed378ec7
LT
570 len--;
571 buf[len] = 0;
572 memcpy(ref_buffer, buf, len + 1);
573 ref = ref_buffer;
8da19775
JH
574 if (flag)
575 *flag |= REF_ISSYMREF;
8a65ff76 576 }
a876ed83
JH
577 if (len < 40 || get_sha1_hex(buffer, sha1))
578 return NULL;
ed378ec7 579 return ref;
a876ed83
JH
580}
581
d08bae7e
IL
582/* The argument to filter_refs */
583struct ref_filter {
584 const char *pattern;
585 each_ref_fn *fn;
586 void *cb_data;
587};
588
ed378ec7 589int read_ref(const char *ref, unsigned char *sha1)
a876ed83 590{
8da19775 591 if (resolve_ref(ref, sha1, 1, NULL))
a876ed83
JH
592 return 0;
593 return -1;
8a65ff76
LT
594}
595
f8948e2f 596#define DO_FOR_EACH_INCLUDE_BROKEN 01
ef06b918 597static int do_one_ref(const char *base, each_ref_fn fn, int trim,
f8948e2f 598 int flags, void *cb_data, struct ref_list *entry)
ef06b918
JH
599{
600 if (strncmp(base, entry->name, trim))
601 return 0;
e01de1c9 602
f8948e2f 603 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
e01de1c9
JH
604 if (entry->flag & REF_BROKEN)
605 return 0; /* ignore dangling symref */
f8948e2f
JH
606 if (!has_sha1_file(entry->sha1)) {
607 error("%s does not point to a valid object!", entry->name);
608 return 0;
609 }
ef06b918 610 }
0ae91be0 611 current_ref = entry;
ef06b918
JH
612 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
613}
614
d08bae7e
IL
615static int filter_refs(const char *ref, const unsigned char *sha, int flags,
616 void *data)
617{
618 struct ref_filter *filter = (struct ref_filter *)data;
619 if (fnmatch(filter->pattern, ref, 0))
620 return 0;
621 return filter->fn(ref, sha, flags, filter->cb_data);
622}
623
cf0adba7
JH
624int peel_ref(const char *ref, unsigned char *sha1)
625{
626 int flag;
627 unsigned char base[20];
628 struct object *o;
629
0ae91be0
SP
630 if (current_ref && (current_ref->name == ref
631 || !strcmp(current_ref->name, ref))) {
632 if (current_ref->flag & REF_KNOWS_PEELED) {
633 hashcpy(sha1, current_ref->peeled);
634 return 0;
635 }
636 hashcpy(base, current_ref->sha1);
637 goto fallback;
638 }
639
cf0adba7
JH
640 if (!resolve_ref(ref, base, 1, &flag))
641 return -1;
642
643 if ((flag & REF_ISPACKED)) {
0bad611b 644 struct ref_list *list = get_packed_refs(NULL);
cf0adba7
JH
645
646 while (list) {
f4204ab9
JH
647 if (!strcmp(list->name, ref)) {
648 if (list->flag & REF_KNOWS_PEELED) {
649 hashcpy(sha1, list->peeled);
650 return 0;
651 }
652 /* older pack-refs did not leave peeled ones */
653 break;
cf0adba7
JH
654 }
655 list = list->next;
656 }
cf0adba7
JH
657 }
658
0ae91be0 659fallback:
cf0adba7 660 o = parse_object(base);
8c87dc77 661 if (o && o->type == OBJ_TAG) {
cf0adba7
JH
662 o = deref_tag(o, ref, 0);
663 if (o) {
664 hashcpy(sha1, o->sha1);
665 return 0;
666 }
667 }
668 return -1;
669}
670
0bad611b
HV
671static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
672 int trim, int flags, void *cb_data)
8a65ff76 673{
0ae91be0 674 int retval = 0;
0bad611b
HV
675 struct ref_list *packed = get_packed_refs(submodule);
676 struct ref_list *loose = get_loose_refs(submodule);
8a65ff76 677
e142a3c6
DB
678 struct ref_list *extra;
679
680 for (extra = extra_refs; extra; extra = extra->next)
f8948e2f 681 retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
e142a3c6 682
e1e22e37
LT
683 while (packed && loose) {
684 struct ref_list *entry;
685 int cmp = strcmp(packed->name, loose->name);
686 if (!cmp) {
687 packed = packed->next;
688 continue;
6cada6a9 689 }
e1e22e37
LT
690 if (cmp > 0) {
691 entry = loose;
692 loose = loose->next;
693 } else {
694 entry = packed;
695 packed = packed->next;
696 }
f8948e2f 697 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
e1e22e37 698 if (retval)
0ae91be0 699 goto end_each;
e1e22e37 700 }
8a65ff76 701
ef06b918 702 for (packed = packed ? packed : loose; packed; packed = packed->next) {
f8948e2f 703 retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
ef06b918 704 if (retval)
0ae91be0 705 goto end_each;
8a65ff76 706 }
0ae91be0
SP
707
708end_each:
709 current_ref = NULL;
710 return retval;
8a65ff76
LT
711}
712
0bad611b
HV
713
714static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
715{
716 unsigned char sha1[20];
8da19775
JH
717 int flag;
718
0bad611b
HV
719 if (submodule) {
720 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
721 return fn("HEAD", sha1, 0, cb_data);
722
723 return 0;
724 }
725
8da19775
JH
726 if (resolve_ref("HEAD", sha1, 1, &flag))
727 return fn("HEAD", sha1, flag, cb_data);
0bad611b 728
2f34ba32 729 return 0;
723c31fe
LT
730}
731
0bad611b
HV
732int head_ref(each_ref_fn fn, void *cb_data)
733{
734 return do_head_ref(NULL, fn, cb_data);
735}
736
9ef6aeb0
HV
737int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
738{
739 return do_head_ref(submodule, fn, cb_data);
740}
741
cb5d709f 742int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 743{
0bad611b 744 return do_for_each_ref(NULL, "refs/", fn, 0, 0, cb_data);
a62be77f
SE
745}
746
9ef6aeb0
HV
747int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
748{
749 return do_for_each_ref(submodule, "refs/", fn, 0, 0, cb_data);
a62be77f
SE
750}
751
2a8177b6
CC
752int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
753{
0bad611b 754 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
755}
756
9ef6aeb0
HV
757int for_each_ref_in_submodule(const char *submodule, const char *prefix,
758 each_ref_fn fn, void *cb_data)
759{
760 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
761}
762
cb5d709f 763int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 764{
2a8177b6 765 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
766}
767
9ef6aeb0
HV
768int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
769{
770 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
771}
772
cb5d709f 773int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 774{
2a8177b6 775 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
776}
777
9ef6aeb0
HV
778int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
779{
780 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
781}
782
cb5d709f 783int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 784{
2a8177b6 785 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
786}
787
9ef6aeb0
HV
788int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
789{
790 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
791}
792
29268700
CC
793int for_each_replace_ref(each_ref_fn fn, void *cb_data)
794{
0bad611b 795 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
796}
797
b09fe971
IL
798int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
799 const char *prefix, void *cb_data)
d08bae7e
IL
800{
801 struct strbuf real_pattern = STRBUF_INIT;
802 struct ref_filter filter;
d08bae7e
IL
803 int ret;
804
b09fe971 805 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 806 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
807 else if (prefix)
808 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
809 strbuf_addstr(&real_pattern, pattern);
810
894a9d33 811 if (!has_glob_specials(pattern)) {
9517e6b8 812 /* Append implied '/' '*' if not present. */
d08bae7e
IL
813 if (real_pattern.buf[real_pattern.len - 1] != '/')
814 strbuf_addch(&real_pattern, '/');
815 /* No need to check for '*', there is none. */
816 strbuf_addch(&real_pattern, '*');
817 }
818
819 filter.pattern = real_pattern.buf;
820 filter.fn = fn;
821 filter.cb_data = cb_data;
822 ret = for_each_ref(filter_refs, &filter);
823
824 strbuf_release(&real_pattern);
825 return ret;
826}
827
b09fe971
IL
828int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
829{
830 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
831}
832
f8948e2f
JH
833int for_each_rawref(each_ref_fn fn, void *cb_data)
834{
0bad611b 835 return do_for_each_ref(NULL, "refs/", fn, 0,
f8948e2f 836 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
837}
838
03feddd6
JH
839/*
840 * Make sure "ref" is something reasonable to have under ".git/refs/";
841 * We do not like it if:
842 *
843 * - any path component of it begins with ".", or
844 * - it has double dots "..", or
845 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
846 * - it ends with a "/".
3e262b95 847 * - it ends with ".lock"
a4c2e699 848 * - it contains a "\" (backslash)
03feddd6
JH
849 */
850
851static inline int bad_ref_char(int ch)
852{
8558fd9e 853 if (((unsigned) ch) <= ' ' ||
a4c2e699 854 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
8558fd9e
DB
855 return 1;
856 /* 2.13 Pattern Matching Notation */
857 if (ch == '?' || ch == '[') /* Unsupported */
858 return 1;
859 if (ch == '*') /* Supported at the end */
860 return 2;
861 return 0;
03feddd6
JH
862}
863
95fc7512
DB
864int check_ref_format(const char *ref)
865{
cbdffe40 866 int ch, level, bad_type, last;
abd2bde7 867 int ret = CHECK_REF_FORMAT_OK;
03feddd6
JH
868 const char *cp = ref;
869
870 level = 0;
871 while (1) {
872 while ((ch = *cp++) == '/')
873 ; /* tolerate duplicated slashes */
874 if (!ch)
5f7b202a
JH
875 /* should not end with slashes */
876 return CHECK_REF_FORMAT_ERROR;
03feddd6
JH
877
878 /* we are at the beginning of the path component */
8558fd9e 879 if (ch == '.')
5f7b202a 880 return CHECK_REF_FORMAT_ERROR;
8558fd9e
DB
881 bad_type = bad_ref_char(ch);
882 if (bad_type) {
abd2bde7
DB
883 if (bad_type == 2 && (!*cp || *cp == '/') &&
884 ret == CHECK_REF_FORMAT_OK)
885 ret = CHECK_REF_FORMAT_WILDCARD;
886 else
887 return CHECK_REF_FORMAT_ERROR;
8558fd9e 888 }
03feddd6 889
cbdffe40 890 last = ch;
03feddd6
JH
891 /* scan the rest of the path component */
892 while ((ch = *cp++) != 0) {
8558fd9e 893 bad_type = bad_ref_char(ch);
cbdffe40 894 if (bad_type)
08fbdb30 895 return CHECK_REF_FORMAT_ERROR;
03feddd6
JH
896 if (ch == '/')
897 break;
cbdffe40
JH
898 if (last == '.' && ch == '.')
899 return CHECK_REF_FORMAT_ERROR;
900 if (last == '@' && ch == '{')
5f7b202a 901 return CHECK_REF_FORMAT_ERROR;
cbdffe40 902 last = ch;
03feddd6
JH
903 }
904 level++;
905 if (!ch) {
cbdffe40
JH
906 if (ref <= cp - 2 && cp[-2] == '.')
907 return CHECK_REF_FORMAT_ERROR;
03feddd6 908 if (level < 2)
5f7b202a 909 return CHECK_REF_FORMAT_ONELEVEL;
3e262b95
SP
910 if (has_extension(ref, ".lock"))
911 return CHECK_REF_FORMAT_ERROR;
abd2bde7 912 return ret;
03feddd6
JH
913 }
914 }
95fc7512
DB
915}
916
4577e483 917const char *prettify_refname(const char *name)
a9c37a72 918{
a9c37a72
DB
919 return name + (
920 !prefixcmp(name, "refs/heads/") ? 11 :
921 !prefixcmp(name, "refs/tags/") ? 10 :
922 !prefixcmp(name, "refs/remotes/") ? 13 :
923 0);
924}
925
79803322
SP
926const char *ref_rev_parse_rules[] = {
927 "%.*s",
928 "refs/%.*s",
929 "refs/tags/%.*s",
930 "refs/heads/%.*s",
931 "refs/remotes/%.*s",
932 "refs/remotes/%.*s/HEAD",
933 NULL
934};
935
605b4978
SP
936const char *ref_fetch_rules[] = {
937 "%.*s",
938 "refs/%.*s",
939 "refs/heads/%.*s",
940 NULL
941};
942
79803322
SP
943int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
944{
945 const char **p;
946 const int abbrev_name_len = strlen(abbrev_name);
947
948 for (p = rules; *p; p++) {
949 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
950 return 1;
951 }
952 }
953
954 return 0;
955}
956
e5f38ec3 957static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
958 const unsigned char *old_sha1, int mustexist)
959{
8da19775 960 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 961 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
962 unlock_ref(lock);
963 return NULL;
964 }
a89fccd2 965 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 966 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
967 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
968 unlock_ref(lock);
969 return NULL;
970 }
971 return lock;
972}
973
7155b727 974static int remove_empty_directories(const char *file)
bc7127ef
JH
975{
976 /* we want to create a file but there is a directory there;
977 * if that is an empty directory (or a directory that contains
978 * only empty directories), remove them.
979 */
7155b727
JS
980 struct strbuf path;
981 int result;
bc7127ef 982
7155b727
JS
983 strbuf_init(&path, 20);
984 strbuf_addstr(&path, file);
985
a0f4afbe 986 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
987
988 strbuf_release(&path);
989
990 return result;
bc7127ef
JH
991}
992
c976d415
LH
993static int is_refname_available(const char *ref, const char *oldref,
994 struct ref_list *list, int quiet)
995{
996 int namlen = strlen(ref); /* e.g. 'foo/bar' */
997 while (list) {
998 /* list->name could be 'foo' or 'foo/bar/baz' */
999 if (!oldref || strcmp(oldref, list->name)) {
1000 int len = strlen(list->name);
1001 int cmplen = (namlen < len) ? namlen : len;
1002 const char *lead = (namlen < len) ? list->name : ref;
1003 if (!strncmp(ref, list->name, cmplen) &&
1004 lead[cmplen] == '/') {
1005 if (!quiet)
1006 error("'%s' exists; cannot create '%s'",
1007 list->name, ref);
1008 return 0;
1009 }
1010 }
1011 list = list->next;
1012 }
1013 return 1;
1014}
1015
68db31cc 1016static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
4bd18c43 1017{
434cd0cd 1018 char *ref_file;
ed378ec7 1019 const char *orig_ref = ref;
4bd18c43 1020 struct ref_lock *lock;
5cc3cef9 1021 int last_errno = 0;
acd3b9ec 1022 int type, lflags;
4431fcc4 1023 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1024 int missing = 0;
4bd18c43
SP
1025
1026 lock = xcalloc(1, sizeof(struct ref_lock));
1027 lock->lock_fd = -1;
1028
68db31cc 1029 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
bc7127ef
JH
1030 if (!ref && errno == EISDIR) {
1031 /* we are trying to lock foo but we used to
1032 * have foo/bar which now does not exist;
1033 * it is normal for the empty directory 'foo'
1034 * to remain.
1035 */
1036 ref_file = git_path("%s", orig_ref);
5cc3cef9
JH
1037 if (remove_empty_directories(ref_file)) {
1038 last_errno = errno;
1039 error("there are still refs under '%s'", orig_ref);
1040 goto error_return;
1041 }
68db31cc 1042 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
bc7127ef 1043 }
68db31cc
SV
1044 if (type_p)
1045 *type_p = type;
ed378ec7 1046 if (!ref) {
5cc3cef9 1047 last_errno = errno;
818f477c 1048 error("unable to resolve reference %s: %s",
ed378ec7 1049 orig_ref, strerror(errno));
5cc3cef9 1050 goto error_return;
4bd18c43 1051 }
5bdd8d4a 1052 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1053 /* When the ref did not exist and we are creating it,
1054 * make sure there is no existing ref that is packed
1055 * whose name begins with our refname, nor a ref whose
1056 * name is a proper prefix of our refname.
1057 */
5bdd8d4a 1058 if (missing &&
0bad611b 1059 !is_refname_available(ref, NULL, get_packed_refs(NULL), 0)) {
f475e08e 1060 last_errno = ENOTDIR;
c976d415 1061 goto error_return;
f475e08e 1062 }
22a3844e 1063
c33d5174 1064 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1065
acd3b9ec
JH
1066 lflags = LOCK_DIE_ON_ERROR;
1067 if (flags & REF_NODEREF) {
68db31cc 1068 ref = orig_ref;
acd3b9ec
JH
1069 lflags |= LOCK_NODEREF;
1070 }
434cd0cd 1071 lock->ref_name = xstrdup(ref);
1655707c 1072 lock->orig_ref_name = xstrdup(orig_ref);
7c1a278d 1073 ref_file = git_path("%s", ref);
5bdd8d4a 1074 if (missing)
68db31cc
SV
1075 lock->force_write = 1;
1076 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1077 lock->force_write = 1;
4bd18c43 1078
5cc3cef9
JH
1079 if (safe_create_leading_directories(ref_file)) {
1080 last_errno = errno;
1081 error("unable to create directory for %s", ref_file);
1082 goto error_return;
1083 }
4bd18c43 1084
acd3b9ec 1085 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1086 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1087
1088 error_return:
1089 unlock_ref(lock);
1090 errno = last_errno;
1091 return NULL;
4bd18c43
SP
1092}
1093
4431fcc4 1094struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
95fc7512 1095{
53cce84c 1096 char refpath[PATH_MAX];
95fc7512 1097 if (check_ref_format(ref))
4bd18c43 1098 return NULL;
53cce84c 1099 strcpy(refpath, mkpath("refs/%s", ref));
68db31cc 1100 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1101}
1102
68db31cc 1103struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
4bd18c43 1104{
5f7b202a 1105 switch (check_ref_format(ref)) {
5f7b202a 1106 default:
257f3020
JH
1107 return NULL;
1108 case 0:
1109 case CHECK_REF_FORMAT_ONELEVEL:
5f7b202a
JH
1110 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
1111 }
c0277d15
JH
1112}
1113
26a063a1
JH
1114static struct lock_file packlock;
1115
c0277d15
JH
1116static int repack_without_ref(const char *refname)
1117{
1118 struct ref_list *list, *packed_ref_list;
1119 int fd;
1120 int found = 0;
c0277d15 1121
0bad611b 1122 packed_ref_list = get_packed_refs(NULL);
c0277d15
JH
1123 for (list = packed_ref_list; list; list = list->next) {
1124 if (!strcmp(refname, list->name)) {
1125 found = 1;
1126 break;
1127 }
1128 }
1129 if (!found)
1130 return 0;
c0277d15 1131 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1b018fd9
MV
1132 if (fd < 0) {
1133 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 1134 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 1135 }
c0277d15
JH
1136
1137 for (list = packed_ref_list; list; list = list->next) {
1138 char line[PATH_MAX + 100];
1139 int len;
1140
1141 if (!strcmp(refname, list->name))
1142 continue;
1143 len = snprintf(line, sizeof(line), "%s %s\n",
1144 sha1_to_hex(list->sha1), list->name);
1145 /* this should not happen but just being defensive */
1146 if (len > sizeof(line))
1147 die("too long a refname '%s'", list->name);
1148 write_or_die(fd, line, len);
1149 }
1150 return commit_lock_file(&packlock);
1151}
1152
eca35a25 1153int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
1154{
1155 struct ref_lock *lock;
eca35a25 1156 int err, i = 0, ret = 0, flag = 0;
c0277d15 1157
68db31cc 1158 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
c0277d15
JH
1159 if (!lock)
1160 return 1;
045a476f 1161 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 1162 /* loose */
eca35a25
MV
1163 const char *path;
1164
1165 if (!(delopt & REF_NODEREF)) {
1166 i = strlen(lock->lk->filename) - 5; /* .lock */
1167 lock->lk->filename[i] = 0;
1168 path = lock->lk->filename;
1169 } else {
9db56f71 1170 path = git_path("%s", refname);
eca35a25 1171 }
691f1a28
AR
1172 err = unlink_or_warn(path);
1173 if (err && errno != ENOENT)
c0277d15 1174 ret = 1;
691f1a28 1175
eca35a25
MV
1176 if (!(delopt & REF_NODEREF))
1177 lock->lk->filename[i] = '.';
c0277d15
JH
1178 }
1179 /* removing the loose one could have resurrected an earlier
1180 * packed one. Also, if it was not loose we need to repack
1181 * without it.
1182 */
1183 ret |= repack_without_ref(refname);
1184
691f1a28 1185 unlink_or_warn(git_path("logs/%s", lock->ref_name));
c0277d15
JH
1186 invalidate_cached_refs();
1187 unlock_ref(lock);
1188 return ret;
4bd18c43
SP
1189}
1190
765c2258
PH
1191/*
1192 * People using contrib's git-new-workdir have .git/logs/refs ->
1193 * /some/other/path/.git/logs/refs, and that may live on another device.
1194 *
1195 * IOW, to avoid cross device rename errors, the temporary renamed log must
1196 * live into logs/refs.
1197 */
1198#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1199
678d0f4c 1200int rename_ref(const char *oldref, const char *newref, const char *logmsg)
c976d415
LH
1201{
1202 static const char renamed_ref[] = "RENAMED-REF";
1203 unsigned char sha1[20], orig_sha1[20];
1204 int flag = 0, logmoved = 0;
1205 struct ref_lock *lock;
c976d415 1206 struct stat loginfo;
16c2bfbb 1207 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
eca35a25 1208 const char *symref = NULL;
c976d415 1209
450d4c0f 1210 if (log && S_ISLNK(loginfo.st_mode))
c976d415
LH
1211 return error("reflog for %s is a symlink", oldref);
1212
eca35a25
MV
1213 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1214 if (flag & REF_ISSYMREF)
fa58186c
MV
1215 return error("refname %s is a symbolic ref, renaming it is not supported",
1216 oldref);
eca35a25 1217 if (!symref)
c976d415
LH
1218 return error("refname %s not found", oldref);
1219
0bad611b 1220 if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
c976d415
LH
1221 return 1;
1222
0bad611b 1223 if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
c976d415
LH
1224 return 1;
1225
68db31cc 1226 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
c976d415
LH
1227 if (!lock)
1228 return error("unable to lock %s", renamed_ref);
1229 lock->force_write = 1;
678d0f4c 1230 if (write_ref_sha1(lock, orig_sha1, logmsg))
c976d415
LH
1231 return error("unable to save current sha1 in %s", renamed_ref);
1232
765c2258
PH
1233 if (log && rename(git_path("logs/%s", oldref), git_path(TMP_RENAMED_LOG)))
1234 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
c976d415
LH
1235 oldref, strerror(errno));
1236
eca35a25 1237 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
c976d415
LH
1238 error("unable to delete old %s", oldref);
1239 goto rollback;
1240 }
1241
eca35a25 1242 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
c976d415
LH
1243 if (errno==EISDIR) {
1244 if (remove_empty_directories(git_path("%s", newref))) {
1245 error("Directory not empty: %s", newref);
1246 goto rollback;
1247 }
1248 } else {
1249 error("unable to delete existing %s", newref);
1250 goto rollback;
1251 }
1252 }
1253
1254 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1255 error("unable to create directory for %s", newref);
1256 goto rollback;
1257 }
1258
1259 retry:
765c2258 1260 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newref))) {
d9e74d57
JR
1261 if (errno==EISDIR || errno==ENOTDIR) {
1262 /*
1263 * rename(a, b) when b is an existing
1264 * directory ought to result in ISDIR, but
1265 * Solaris 5.8 gives ENOTDIR. Sheesh.
1266 */
c976d415
LH
1267 if (remove_empty_directories(git_path("logs/%s", newref))) {
1268 error("Directory not empty: logs/%s", newref);
1269 goto rollback;
1270 }
1271 goto retry;
1272 } else {
765c2258 1273 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
c976d415
LH
1274 newref, strerror(errno));
1275 goto rollback;
1276 }
1277 }
1278 logmoved = log;
1279
68db31cc 1280 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
c976d415
LH
1281 if (!lock) {
1282 error("unable to lock %s for update", newref);
1283 goto rollback;
1284 }
c976d415
LH
1285 lock->force_write = 1;
1286 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 1287 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
c976d415
LH
1288 error("unable to write current sha1 into %s", newref);
1289 goto rollback;
1290 }
1291
1292 return 0;
1293
1294 rollback:
68db31cc 1295 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
c976d415
LH
1296 if (!lock) {
1297 error("unable to lock %s for rollback", oldref);
1298 goto rollbacklog;
1299 }
1300
1301 lock->force_write = 1;
1302 flag = log_all_ref_updates;
1303 log_all_ref_updates = 0;
1304 if (write_ref_sha1(lock, orig_sha1, NULL))
1305 error("unable to write current sha1 into %s", oldref);
1306 log_all_ref_updates = flag;
1307
1308 rollbacklog:
1309 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1310 error("unable to restore logfile %s from %s: %s",
1311 oldref, newref, strerror(errno));
1312 if (!logmoved && log &&
765c2258
PH
1313 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldref)))
1314 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
c976d415
LH
1315 oldref, strerror(errno));
1316
1317 return 1;
1318}
1319
435fc852 1320int close_ref(struct ref_lock *lock)
b531394d
BC
1321{
1322 if (close_lock_file(lock->lk))
1323 return -1;
1324 lock->lock_fd = -1;
1325 return 0;
1326}
1327
435fc852 1328int commit_ref(struct ref_lock *lock)
b531394d
BC
1329{
1330 if (commit_lock_file(lock->lk))
1331 return -1;
1332 lock->lock_fd = -1;
1333 return 0;
1334}
1335
e5f38ec3 1336void unlock_ref(struct ref_lock *lock)
4bd18c43 1337{
4ed7cd3a
BC
1338 /* Do not free lock->lk -- atexit() still looks at them */
1339 if (lock->lk)
1340 rollback_lock_file(lock->lk);
434cd0cd 1341 free(lock->ref_name);
1655707c 1342 free(lock->orig_ref_name);
4bd18c43
SP
1343 free(lock);
1344}
1345
0ec29a47
JH
1346/*
1347 * copy the reflog message msg to buf, which has been allocated sufficiently
1348 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1349 * because reflog file is one line per entry.
1350 */
1351static int copy_msg(char *buf, const char *msg)
1352{
1353 char *cp = buf;
1354 char c;
1355 int wasspace = 1;
1356
1357 *cp++ = '\t';
1358 while ((c = *msg++)) {
1359 if (wasspace && isspace(c))
1360 continue;
1361 wasspace = isspace(c);
1362 if (wasspace)
1363 c = ' ';
1364 *cp++ = c;
1365 }
1366 while (buf < cp && isspace(cp[-1]))
1367 cp--;
1368 *cp++ = '\n';
1369 return cp - buf;
1370}
1371
157aaea5 1372int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
6de08ae6 1373{
859c3017 1374 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 1375
157aaea5 1376 git_snpath(logfile, bufsize, "logs/%s", ref_name);
4057deb5 1377 if (log_all_ref_updates &&
cc44c765
JH
1378 (!prefixcmp(ref_name, "refs/heads/") ||
1379 !prefixcmp(ref_name, "refs/remotes/") ||
b2e256b0 1380 !prefixcmp(ref_name, "refs/notes/") ||
bd104db1 1381 !strcmp(ref_name, "HEAD"))) {
157aaea5 1382 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 1383 return error("unable to create directory for %s",
157aaea5 1384 logfile);
6de08ae6
SP
1385 oflags |= O_CREAT;
1386 }
1387
157aaea5 1388 logfd = open(logfile, oflags, 0666);
6de08ae6 1389 if (logfd < 0) {
1974bf62 1390 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 1391 return 0;
3b463c3f
JH
1392
1393 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 1394 if (remove_empty_directories(logfile)) {
3b463c3f 1395 return error("There are still logs under '%s'",
157aaea5 1396 logfile);
3b463c3f 1397 }
157aaea5 1398 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
1399 }
1400
1401 if (logfd < 0)
1402 return error("Unable to append to %s: %s",
157aaea5 1403 logfile, strerror(errno));
6de08ae6
SP
1404 }
1405
157aaea5 1406 adjust_shared_perm(logfile);
859c3017
EM
1407 close(logfd);
1408 return 0;
1409}
443b92b6 1410
859c3017
EM
1411static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1412 const unsigned char *new_sha1, const char *msg)
1413{
1414 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1415 unsigned maxlen, len;
1416 int msglen;
157aaea5 1417 char log_file[PATH_MAX];
859c3017
EM
1418 char *logrec;
1419 const char *committer;
1420
1421 if (log_all_ref_updates < 0)
1422 log_all_ref_updates = !is_bare_repository();
1423
157aaea5 1424 result = log_ref_setup(ref_name, log_file, sizeof(log_file));
859c3017
EM
1425 if (result)
1426 return result;
1427
1428 logfd = open(log_file, oflags);
1429 if (logfd < 0)
1430 return 0;
0ec29a47 1431 msglen = msg ? strlen(msg) : 0;
774751a8 1432 committer = git_committer_info(0);
8ac65937
JH
1433 maxlen = strlen(committer) + msglen + 100;
1434 logrec = xmalloc(maxlen);
1435 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
1436 sha1_to_hex(old_sha1),
1437 sha1_to_hex(new_sha1),
8ac65937
JH
1438 committer);
1439 if (msglen)
0ec29a47 1440 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 1441 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 1442 free(logrec);
91c8d590 1443 if (close(logfd) != 0 || written != len)
9a13f0b7 1444 return error("Unable to append to %s", log_file);
6de08ae6
SP
1445 return 0;
1446}
1447
c3b0dec5
LT
1448static int is_branch(const char *refname)
1449{
1450 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1451}
1452
4bd18c43
SP
1453int write_ref_sha1(struct ref_lock *lock,
1454 const unsigned char *sha1, const char *logmsg)
1455{
1456 static char term = '\n';
c3b0dec5 1457 struct object *o;
4bd18c43
SP
1458
1459 if (!lock)
95fc7512 1460 return -1;
a89fccd2 1461 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
1462 unlock_ref(lock);
1463 return 0;
95fc7512 1464 }
c3b0dec5
LT
1465 o = parse_object(sha1);
1466 if (!o) {
7be8b3ba 1467 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
1468 lock->ref_name, sha1_to_hex(sha1));
1469 unlock_ref(lock);
1470 return -1;
1471 }
1472 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1473 error("Trying to write non-commit object %s to branch %s",
1474 sha1_to_hex(sha1), lock->ref_name);
1475 unlock_ref(lock);
1476 return -1;
1477 }
93822c22
AW
1478 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1479 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 1480 || close_ref(lock) < 0) {
c33d5174 1481 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
1482 unlock_ref(lock);
1483 return -1;
1484 }
5e290ff7 1485 invalidate_cached_refs();
bd104db1
NP
1486 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1487 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1488 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
1489 unlock_ref(lock);
1490 return -1;
1491 }
605fac8b
NP
1492 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1493 /*
1494 * Special hack: If a branch is updated directly and HEAD
1495 * points to it (may happen on the remote side of a push
1496 * for example) then logically the HEAD reflog should be
1497 * updated too.
1498 * A generic solution implies reverse symref information,
1499 * but finding all symrefs pointing to the given branch
1500 * would be rather costly for this rare event (the direct
1501 * update of a branch) to be worth it. So let's cheat and
1502 * check with HEAD only which should cover 99% of all usage
1503 * scenarios (even 100% of the default ones).
1504 */
1505 unsigned char head_sha1[20];
1506 int head_flag;
1507 const char *head_ref;
1508 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1509 if (head_ref && (head_flag & REF_ISSYMREF) &&
1510 !strcmp(head_ref, lock->ref_name))
1511 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1512 }
b531394d 1513 if (commit_ref(lock)) {
434cd0cd 1514 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
1515 unlock_ref(lock);
1516 return -1;
1517 }
4bd18c43
SP
1518 unlock_ref(lock);
1519 return 0;
95fc7512 1520}
d556fae2 1521
8b5157e4
NP
1522int create_symref(const char *ref_target, const char *refs_heads_master,
1523 const char *logmsg)
41b625b0
NP
1524{
1525 const char *lockpath;
1526 char ref[1000];
1527 int fd, len, written;
a4f34cbb 1528 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
1529 unsigned char old_sha1[20], new_sha1[20];
1530
1531 if (logmsg && read_ref(ref_target, old_sha1))
1532 hashclr(old_sha1);
41b625b0 1533
d48744d1
JH
1534 if (safe_create_leading_directories(git_HEAD) < 0)
1535 return error("unable to create directory for %s", git_HEAD);
1536
41b625b0
NP
1537#ifndef NO_SYMLINK_HEAD
1538 if (prefer_symlink_refs) {
1539 unlink(git_HEAD);
1540 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 1541 goto done;
41b625b0
NP
1542 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1543 }
1544#endif
1545
1546 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1547 if (sizeof(ref) <= len) {
1548 error("refname too long: %s", refs_heads_master);
47fc52e2 1549 goto error_free_return;
41b625b0
NP
1550 }
1551 lockpath = mkpath("%s.lock", git_HEAD);
1552 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1553 if (fd < 0) {
1554 error("Unable to open %s for writing", lockpath);
47fc52e2 1555 goto error_free_return;
41b625b0
NP
1556 }
1557 written = write_in_full(fd, ref, len);
91c8d590 1558 if (close(fd) != 0 || written != len) {
41b625b0 1559 error("Unable to write to %s", lockpath);
47fc52e2 1560 goto error_unlink_return;
41b625b0
NP
1561 }
1562 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 1563 error("Unable to create %s", git_HEAD);
47fc52e2 1564 goto error_unlink_return;
41b625b0
NP
1565 }
1566 if (adjust_shared_perm(git_HEAD)) {
41b625b0 1567 error("Unable to fix permissions on %s", lockpath);
47fc52e2 1568 error_unlink_return:
691f1a28 1569 unlink_or_warn(lockpath);
47fc52e2
JH
1570 error_free_return:
1571 free(git_HEAD);
1572 return -1;
41b625b0 1573 }
8b5157e4 1574
ee96d11b 1575#ifndef NO_SYMLINK_HEAD
8b5157e4 1576 done:
ee96d11b 1577#endif
8b5157e4
NP
1578 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1579 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1580
47fc52e2 1581 free(git_HEAD);
41b625b0
NP
1582 return 0;
1583}
1584
16d7cc90
JH
1585static char *ref_msg(const char *line, const char *endp)
1586{
1587 const char *ep;
16d7cc90 1588 line += 82;
182af834
PH
1589 ep = memchr(line, '\n', endp - line);
1590 if (!ep)
1591 ep = endp;
1592 return xmemdupz(line, ep - line);
16d7cc90
JH
1593}
1594
1595int 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 1596{
e5229042 1597 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 1598 char *tz_c;
e29cb53a 1599 int logfd, tz, reccnt = 0;
d556fae2
SP
1600 struct stat st;
1601 unsigned long date;
e5229042 1602 unsigned char logged_sha1[20];
cb48cb58 1603 void *log_mapped;
dc49cd76 1604 size_t mapsz;
d556fae2
SP
1605
1606 logfile = git_path("logs/%s", ref);
1607 logfd = open(logfile, O_RDONLY, 0);
1608 if (logfd < 0)
d824cbba 1609 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
1610 fstat(logfd, &st);
1611 if (!st.st_size)
1612 die("Log %s is empty.", logfile);
dc49cd76
SP
1613 mapsz = xsize_t(st.st_size);
1614 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 1615 logdata = log_mapped;
d556fae2
SP
1616 close(logfd);
1617
e5229042 1618 lastrec = NULL;
d556fae2
SP
1619 rec = logend = logdata + st.st_size;
1620 while (logdata < rec) {
e29cb53a 1621 reccnt++;
d556fae2
SP
1622 if (logdata < rec && *(rec-1) == '\n')
1623 rec--;
e5229042
SP
1624 lastgt = NULL;
1625 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 1626 rec--;
e5229042
SP
1627 if (*rec == '>')
1628 lastgt = rec;
1629 }
1630 if (!lastgt)
d556fae2 1631 die("Log %s is corrupt.", logfile);
e5229042 1632 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 1633 if (date <= at_time || cnt == 0) {
76a44c5c 1634 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
1635 if (msg)
1636 *msg = ref_msg(rec, logend);
1637 if (cutoff_time)
1638 *cutoff_time = date;
1639 if (cutoff_tz)
1640 *cutoff_tz = tz;
1641 if (cutoff_cnt)
76a44c5c 1642 *cutoff_cnt = reccnt - 1;
e5229042
SP
1643 if (lastrec) {
1644 if (get_sha1_hex(lastrec, logged_sha1))
1645 die("Log %s is corrupt.", logfile);
1646 if (get_sha1_hex(rec + 41, sha1))
1647 die("Log %s is corrupt.", logfile);
a89fccd2 1648 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1649 warning("Log %s has gap after %s.",
73013afd 1650 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 1651 }
e5f38ec3
JH
1652 }
1653 else if (date == at_time) {
e5229042
SP
1654 if (get_sha1_hex(rec + 41, sha1))
1655 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
1656 }
1657 else {
e5229042
SP
1658 if (get_sha1_hex(rec + 41, logged_sha1))
1659 die("Log %s is corrupt.", logfile);
a89fccd2 1660 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1661 warning("Log %s unexpectedly ended on %s.",
73013afd 1662 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
1663 }
1664 }
dc49cd76 1665 munmap(log_mapped, mapsz);
d556fae2
SP
1666 return 0;
1667 }
e5229042 1668 lastrec = rec;
ab2a1a32
JH
1669 if (cnt > 0)
1670 cnt--;
d556fae2
SP
1671 }
1672
e5229042
SP
1673 rec = logdata;
1674 while (rec < logend && *rec != '>' && *rec != '\n')
1675 rec++;
1676 if (rec == logend || *rec == '\n')
d556fae2 1677 die("Log %s is corrupt.", logfile);
e5229042 1678 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
1679 tz = strtoul(tz_c, NULL, 10);
1680 if (get_sha1_hex(logdata, sha1))
1681 die("Log %s is corrupt.", logfile);
d1a4489a
JK
1682 if (is_null_sha1(sha1)) {
1683 if (get_sha1_hex(logdata + 41, sha1))
1684 die("Log %s is corrupt.", logfile);
1685 }
16d7cc90
JH
1686 if (msg)
1687 *msg = ref_msg(logdata, logend);
dc49cd76 1688 munmap(log_mapped, mapsz);
16d7cc90
JH
1689
1690 if (cutoff_time)
1691 *cutoff_time = date;
1692 if (cutoff_tz)
1693 *cutoff_tz = tz;
1694 if (cutoff_cnt)
1695 *cutoff_cnt = reccnt;
1696 return 1;
d556fae2 1697}
2ff81662 1698
101d15e0 1699int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
1700{
1701 const char *logfile;
1702 FILE *logfp;
8ca78803 1703 struct strbuf sb = STRBUF_INIT;
2266bf27 1704 int ret = 0;
2ff81662
JH
1705
1706 logfile = git_path("logs/%s", ref);
1707 logfp = fopen(logfile, "r");
1708 if (!logfp)
883d60fa 1709 return -1;
101d15e0
JH
1710
1711 if (ofs) {
1712 struct stat statbuf;
1713 if (fstat(fileno(logfp), &statbuf) ||
1714 statbuf.st_size < ofs ||
1715 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 1716 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 1717 fclose(logfp);
8ca78803 1718 strbuf_release(&sb);
101d15e0 1719 return -1;
9d33f7c2 1720 }
101d15e0
JH
1721 }
1722
8ca78803 1723 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 1724 unsigned char osha1[20], nsha1[20];
883d60fa
JS
1725 char *email_end, *message;
1726 unsigned long timestamp;
8ca78803 1727 int tz;
2ff81662
JH
1728
1729 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
1730 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
1731 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
1732 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
1733 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
1734 email_end[1] != ' ' ||
1735 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1736 !message || message[0] != ' ' ||
1737 (message[1] != '+' && message[1] != '-') ||
1738 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 1739 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 1740 continue; /* corrupt? */
883d60fa
JS
1741 email_end[1] = '\0';
1742 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
1743 if (message[6] != '\t')
1744 message += 6;
1745 else
1746 message += 7;
8ca78803
RS
1747 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
1748 cb_data);
883d60fa 1749 if (ret)
2266bf27 1750 break;
2ff81662
JH
1751 }
1752 fclose(logfp);
8ca78803 1753 strbuf_release(&sb);
2266bf27 1754 return ret;
2ff81662 1755}
e29cb53a 1756
101d15e0
JH
1757int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1758{
1759 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1760}
1761
eb8381c8
NP
1762static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1763{
1764 DIR *dir = opendir(git_path("logs/%s", base));
fcee5a14 1765 int retval = 0;
eb8381c8
NP
1766
1767 if (dir) {
1768 struct dirent *de;
1769 int baselen = strlen(base);
1770 char *log = xmalloc(baselen + 257);
1771
1772 memcpy(log, base, baselen);
1773 if (baselen && base[baselen-1] != '/')
1774 log[baselen++] = '/';
1775
1776 while ((de = readdir(dir)) != NULL) {
1777 struct stat st;
1778 int namelen;
1779
1780 if (de->d_name[0] == '.')
1781 continue;
1782 namelen = strlen(de->d_name);
1783 if (namelen > 255)
1784 continue;
1785 if (has_extension(de->d_name, ".lock"))
1786 continue;
1787 memcpy(log + baselen, de->d_name, namelen+1);
1788 if (stat(git_path("logs/%s", log), &st) < 0)
1789 continue;
1790 if (S_ISDIR(st.st_mode)) {
1791 retval = do_for_each_reflog(log, fn, cb_data);
1792 } else {
1793 unsigned char sha1[20];
1794 if (!resolve_ref(log, sha1, 0, NULL))
1795 retval = error("bad ref for %s", log);
1796 else
1797 retval = fn(log, sha1, 0, cb_data);
1798 }
1799 if (retval)
1800 break;
1801 }
1802 free(log);
1803 closedir(dir);
1804 }
acb39f64 1805 else if (*base)
fcee5a14 1806 return errno;
eb8381c8
NP
1807 return retval;
1808}
1809
1810int for_each_reflog(each_ref_fn fn, void *cb_data)
1811{
1812 return do_for_each_reflog("", fn, cb_data);
1813}
3d9f037c
CR
1814
1815int update_ref(const char *action, const char *refname,
1816 const unsigned char *sha1, const unsigned char *oldval,
1817 int flags, enum action_on_err onerr)
1818{
1819 static struct ref_lock *lock;
1820 lock = lock_any_ref_for_update(refname, oldval, flags);
1821 if (!lock) {
1822 const char *str = "Cannot lock the ref '%s'.";
1823 switch (onerr) {
1824 case MSG_ON_ERR: error(str, refname); break;
1825 case DIE_ON_ERR: die(str, refname); break;
1826 case QUIET_ON_ERR: break;
1827 }
1828 return 1;
1829 }
1830 if (write_ref_sha1(lock, sha1, action) < 0) {
1831 const char *str = "Cannot update the ref '%s'.";
1832 switch (onerr) {
1833 case MSG_ON_ERR: error(str, refname); break;
1834 case DIE_ON_ERR: die(str, refname); break;
1835 case QUIET_ON_ERR: break;
1836 }
1837 return 1;
1838 }
1839 return 0;
1840}
cda69f48 1841
c17b2294
JH
1842int ref_exists(char *refname)
1843{
1844 unsigned char sha1[20];
1845 return !!resolve_ref(refname, sha1, 1, NULL);
1846}
1847
5483f799 1848struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
1849{
1850 for ( ; list; list = list->next)
1851 if (!strcmp(list->name, name))
5483f799 1852 return (struct ref *)list;
cda69f48
JK
1853 return NULL;
1854}
7c2b3029
JK
1855
1856/*
1857 * generate a format suitable for scanf from a ref_rev_parse_rules
1858 * rule, that is replace the "%.*s" spec with a "%s" spec
1859 */
1860static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1861{
1862 char *spec;
1863
1864 spec = strstr(rule, "%.*s");
1865 if (!spec || strstr(spec + 4, "%.*s"))
1866 die("invalid rule in ref_rev_parse_rules: %s", rule);
1867
1868 /* copy all until spec */
1869 strncpy(scanf_fmt, rule, spec - rule);
1870 scanf_fmt[spec - rule] = '\0';
1871 /* copy new spec */
1872 strcat(scanf_fmt, "%s");
1873 /* copy remaining rule */
1874 strcat(scanf_fmt, spec + 4);
1875
1876 return;
1877}
1878
6e7b3309 1879char *shorten_unambiguous_ref(const char *ref, int strict)
7c2b3029
JK
1880{
1881 int i;
1882 static char **scanf_fmts;
1883 static int nr_rules;
1884 char *short_name;
1885
1886 /* pre generate scanf formats from ref_rev_parse_rules[] */
1887 if (!nr_rules) {
1888 size_t total_len = 0;
1889
1890 /* the rule list is NULL terminated, count them first */
1891 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
1892 /* no +1 because strlen("%s") < strlen("%.*s") */
1893 total_len += strlen(ref_rev_parse_rules[nr_rules]);
1894
1895 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
1896
1897 total_len = 0;
1898 for (i = 0; i < nr_rules; i++) {
1899 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
1900 + total_len;
1901 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
1902 total_len += strlen(ref_rev_parse_rules[i]);
1903 }
1904 }
1905
1906 /* bail out if there are no rules */
1907 if (!nr_rules)
1908 return xstrdup(ref);
1909
1910 /* buffer for scanf result, at most ref must fit */
1911 short_name = xstrdup(ref);
1912
1913 /* skip first rule, it will always match */
1914 for (i = nr_rules - 1; i > 0 ; --i) {
1915 int j;
6e7b3309 1916 int rules_to_fail = i;
7c2b3029
JK
1917 int short_name_len;
1918
1919 if (1 != sscanf(ref, scanf_fmts[i], short_name))
1920 continue;
1921
1922 short_name_len = strlen(short_name);
1923
6e7b3309
BW
1924 /*
1925 * in strict mode, all (except the matched one) rules
1926 * must fail to resolve to a valid non-ambiguous ref
1927 */
1928 if (strict)
1929 rules_to_fail = nr_rules;
1930
7c2b3029
JK
1931 /*
1932 * check if the short name resolves to a valid ref,
1933 * but use only rules prior to the matched one
1934 */
6e7b3309 1935 for (j = 0; j < rules_to_fail; j++) {
7c2b3029
JK
1936 const char *rule = ref_rev_parse_rules[j];
1937 unsigned char short_objectname[20];
1938 char refname[PATH_MAX];
1939
6e7b3309
BW
1940 /* skip matched rule */
1941 if (i == j)
1942 continue;
1943
7c2b3029
JK
1944 /*
1945 * the short name is ambiguous, if it resolves
1946 * (with this previous rule) to a valid ref
1947 * read_ref() returns 0 on success
1948 */
1949 mksnpath(refname, sizeof(refname),
1950 rule, short_name_len, short_name);
1951 if (!read_ref(refname, short_objectname))
1952 break;
1953 }
1954
1955 /*
1956 * short name is non-ambiguous if all previous rules
1957 * haven't resolved to a valid ref
1958 */
6e7b3309 1959 if (j == rules_to_fail)
7c2b3029
JK
1960 return short_name;
1961 }
1962
1963 free(short_name);
1964 return xstrdup(ref);
1965}