add refname_match()
[git/git.git] / sha1_name.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "commit.h"
4 #include "tree.h"
5 #include "blob.h"
6 #include "tree-walk.h"
7 #include "refs.h"
8
9 static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
10 {
11 struct alternate_object_database *alt;
12 char hex[40];
13 int found = 0;
14 static struct alternate_object_database *fakeent;
15
16 if (!fakeent) {
17 const char *objdir = get_object_directory();
18 int objdir_len = strlen(objdir);
19 int entlen = objdir_len + 43;
20 fakeent = xmalloc(sizeof(*fakeent) + entlen);
21 memcpy(fakeent->base, objdir, objdir_len);
22 fakeent->name = fakeent->base + objdir_len + 1;
23 fakeent->name[-1] = '/';
24 }
25 fakeent->next = alt_odb_list;
26
27 sprintf(hex, "%.2s", name);
28 for (alt = fakeent; alt && found < 2; alt = alt->next) {
29 struct dirent *de;
30 DIR *dir;
31 sprintf(alt->name, "%.2s/", name);
32 dir = opendir(alt->base);
33 if (!dir)
34 continue;
35 while ((de = readdir(dir)) != NULL) {
36 if (strlen(de->d_name) != 38)
37 continue;
38 if (memcmp(de->d_name, name + 2, len - 2))
39 continue;
40 if (!found) {
41 memcpy(hex + 2, de->d_name, 38);
42 found++;
43 }
44 else if (memcmp(hex + 2, de->d_name, 38)) {
45 found = 2;
46 break;
47 }
48 }
49 closedir(dir);
50 }
51 if (found == 1)
52 return get_sha1_hex(hex, sha1) == 0;
53 return found;
54 }
55
56 static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
57 {
58 do {
59 if (*a != *b)
60 return 0;
61 a++;
62 b++;
63 len -= 2;
64 } while (len > 1);
65 if (len)
66 if ((*a ^ *b) & 0xf0)
67 return 0;
68 return 1;
69 }
70
71 static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
72 {
73 struct packed_git *p;
74 const unsigned char *found_sha1 = NULL;
75 int found = 0;
76
77 prepare_packed_git();
78 for (p = packed_git; p && found < 2; p = p->next) {
79 uint32_t num, last;
80 uint32_t first = 0;
81 open_pack_index(p);
82 num = p->num_objects;
83 last = num;
84 while (first < last) {
85 uint32_t mid = (first + last) / 2;
86 const unsigned char *now;
87 int cmp;
88
89 now = nth_packed_object_sha1(p, mid);
90 cmp = hashcmp(match, now);
91 if (!cmp) {
92 first = mid;
93 break;
94 }
95 if (cmp > 0) {
96 first = mid+1;
97 continue;
98 }
99 last = mid;
100 }
101 if (first < num) {
102 const unsigned char *now, *next;
103 now = nth_packed_object_sha1(p, first);
104 if (match_sha(len, match, now)) {
105 next = nth_packed_object_sha1(p, first+1);
106 if (!next|| !match_sha(len, match, next)) {
107 /* unique within this pack */
108 if (!found) {
109 found_sha1 = now;
110 found++;
111 }
112 else if (hashcmp(found_sha1, now)) {
113 found = 2;
114 break;
115 }
116 }
117 else {
118 /* not even unique within this pack */
119 found = 2;
120 break;
121 }
122 }
123 }
124 }
125 if (found == 1)
126 hashcpy(sha1, found_sha1);
127 return found;
128 }
129
130 #define SHORT_NAME_NOT_FOUND (-1)
131 #define SHORT_NAME_AMBIGUOUS (-2)
132
133 static int find_unique_short_object(int len, char *canonical,
134 unsigned char *res, unsigned char *sha1)
135 {
136 int has_unpacked, has_packed;
137 unsigned char unpacked_sha1[20], packed_sha1[20];
138
139 prepare_alt_odb();
140 has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
141 has_packed = find_short_packed_object(len, res, packed_sha1);
142 if (!has_unpacked && !has_packed)
143 return SHORT_NAME_NOT_FOUND;
144 if (1 < has_unpacked || 1 < has_packed)
145 return SHORT_NAME_AMBIGUOUS;
146 if (has_unpacked != has_packed) {
147 hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
148 return 0;
149 }
150 /* Both have unique ones -- do they match? */
151 if (hashcmp(packed_sha1, unpacked_sha1))
152 return SHORT_NAME_AMBIGUOUS;
153 hashcpy(sha1, packed_sha1);
154 return 0;
155 }
156
157 static int get_short_sha1(const char *name, int len, unsigned char *sha1,
158 int quietly)
159 {
160 int i, status;
161 char canonical[40];
162 unsigned char res[20];
163
164 if (len < MINIMUM_ABBREV || len > 40)
165 return -1;
166 hashclr(res);
167 memset(canonical, 'x', 40);
168 for (i = 0; i < len ;i++) {
169 unsigned char c = name[i];
170 unsigned char val;
171 if (c >= '0' && c <= '9')
172 val = c - '0';
173 else if (c >= 'a' && c <= 'f')
174 val = c - 'a' + 10;
175 else if (c >= 'A' && c <='F') {
176 val = c - 'A' + 10;
177 c -= 'A' - 'a';
178 }
179 else
180 return -1;
181 canonical[i] = c;
182 if (!(i & 1))
183 val <<= 4;
184 res[i >> 1] |= val;
185 }
186
187 status = find_unique_short_object(i, canonical, res, sha1);
188 if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
189 return error("short SHA1 %.*s is ambiguous.", len, canonical);
190 return status;
191 }
192
193 const char *find_unique_abbrev(const unsigned char *sha1, int len)
194 {
195 int status, is_null;
196 static char hex[41];
197
198 is_null = is_null_sha1(sha1);
199 memcpy(hex, sha1_to_hex(sha1), 40);
200 if (len == 40 || !len)
201 return hex;
202 while (len < 40) {
203 unsigned char sha1_ret[20];
204 status = get_short_sha1(hex, len, sha1_ret, 1);
205 if (!status ||
206 (is_null && status != SHORT_NAME_AMBIGUOUS)) {
207 hex[len] = 0;
208 return hex;
209 }
210 if (status != SHORT_NAME_AMBIGUOUS)
211 return NULL;
212 len++;
213 }
214 return NULL;
215 }
216
217 static int ambiguous_path(const char *path, int len)
218 {
219 int slash = 1;
220 int cnt;
221
222 for (cnt = 0; cnt < len; cnt++) {
223 switch (*path++) {
224 case '\0':
225 break;
226 case '/':
227 if (slash)
228 break;
229 slash = 1;
230 continue;
231 case '.':
232 continue;
233 default:
234 slash = 0;
235 continue;
236 }
237 break;
238 }
239 return slash;
240 }
241
242 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
243 {
244 const char **p, *r;
245 int refs_found = 0;
246
247 *ref = NULL;
248 for (p = ref_rev_parse_rules; *p; p++) {
249 unsigned char sha1_from_ref[20];
250 unsigned char *this_result;
251
252 this_result = refs_found ? sha1_from_ref : sha1;
253 r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
254 if (r) {
255 if (!refs_found++)
256 *ref = xstrdup(r);
257 if (!warn_ambiguous_refs)
258 break;
259 }
260 }
261 return refs_found;
262 }
263
264 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
265 {
266 const char **p;
267 int logs_found = 0;
268
269 *log = NULL;
270 for (p = ref_rev_parse_rules; *p; p++) {
271 struct stat st;
272 unsigned char hash[20];
273 char path[PATH_MAX];
274 const char *ref, *it;
275
276 strcpy(path, mkpath(*p, len, str));
277 ref = resolve_ref(path, hash, 0, NULL);
278 if (!ref)
279 continue;
280 if (!stat(git_path("logs/%s", path), &st) &&
281 S_ISREG(st.st_mode))
282 it = path;
283 else if (strcmp(ref, path) &&
284 !stat(git_path("logs/%s", ref), &st) &&
285 S_ISREG(st.st_mode))
286 it = ref;
287 else
288 continue;
289 if (!logs_found++) {
290 *log = xstrdup(it);
291 hashcpy(sha1, hash);
292 }
293 if (!warn_ambiguous_refs)
294 break;
295 }
296 return logs_found;
297 }
298
299 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
300 {
301 static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
302 char *real_ref = NULL;
303 int refs_found = 0;
304 int at, reflog_len;
305
306 if (len == 40 && !get_sha1_hex(str, sha1))
307 return 0;
308
309 /* basic@{time or number} format to query ref-log */
310 reflog_len = at = 0;
311 if (str[len-1] == '}') {
312 for (at = 0; at < len - 1; at++) {
313 if (str[at] == '@' && str[at+1] == '{') {
314 reflog_len = (len-1) - (at+2);
315 len = at;
316 break;
317 }
318 }
319 }
320
321 /* Accept only unambiguous ref paths. */
322 if (len && ambiguous_path(str, len))
323 return -1;
324
325 if (!len && reflog_len) {
326 /* allow "@{...}" to mean the current branch reflog */
327 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
328 } else if (reflog_len)
329 refs_found = dwim_log(str, len, sha1, &real_ref);
330 else
331 refs_found = dwim_ref(str, len, sha1, &real_ref);
332
333 if (!refs_found)
334 return -1;
335
336 if (warn_ambiguous_refs && refs_found > 1)
337 fprintf(stderr, warning, len, str);
338
339 if (reflog_len) {
340 int nth, i;
341 unsigned long at_time;
342 unsigned long co_time;
343 int co_tz, co_cnt;
344
345 /* Is it asking for N-th entry, or approxidate? */
346 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
347 char ch = str[at+2+i];
348 if ('0' <= ch && ch <= '9')
349 nth = nth * 10 + ch - '0';
350 else
351 nth = -1;
352 }
353 if (0 <= nth)
354 at_time = 0;
355 else
356 at_time = approxidate(str + at + 2);
357 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
358 &co_time, &co_tz, &co_cnt)) {
359 if (at_time)
360 fprintf(stderr,
361 "warning: Log for '%.*s' only goes "
362 "back to %s.\n", len, str,
363 show_date(co_time, co_tz, DATE_RFC2822));
364 else
365 fprintf(stderr,
366 "warning: Log for '%.*s' only has "
367 "%d entries.\n", len, str, co_cnt);
368 }
369 }
370
371 free(real_ref);
372 return 0;
373 }
374
375 static int get_sha1_1(const char *name, int len, unsigned char *sha1);
376
377 static int get_parent(const char *name, int len,
378 unsigned char *result, int idx)
379 {
380 unsigned char sha1[20];
381 int ret = get_sha1_1(name, len, sha1);
382 struct commit *commit;
383 struct commit_list *p;
384
385 if (ret)
386 return ret;
387 commit = lookup_commit_reference(sha1);
388 if (!commit)
389 return -1;
390 if (parse_commit(commit))
391 return -1;
392 if (!idx) {
393 hashcpy(result, commit->object.sha1);
394 return 0;
395 }
396 p = commit->parents;
397 while (p) {
398 if (!--idx) {
399 hashcpy(result, p->item->object.sha1);
400 return 0;
401 }
402 p = p->next;
403 }
404 return -1;
405 }
406
407 static int get_nth_ancestor(const char *name, int len,
408 unsigned char *result, int generation)
409 {
410 unsigned char sha1[20];
411 int ret = get_sha1_1(name, len, sha1);
412 if (ret)
413 return ret;
414
415 while (generation--) {
416 struct commit *commit = lookup_commit_reference(sha1);
417
418 if (!commit || parse_commit(commit) || !commit->parents)
419 return -1;
420 hashcpy(sha1, commit->parents->item->object.sha1);
421 }
422 hashcpy(result, sha1);
423 return 0;
424 }
425
426 static int peel_onion(const char *name, int len, unsigned char *sha1)
427 {
428 unsigned char outer[20];
429 const char *sp;
430 unsigned int expected_type = 0;
431 struct object *o;
432
433 /*
434 * "ref^{type}" dereferences ref repeatedly until you cannot
435 * dereference anymore, or you get an object of given type,
436 * whichever comes first. "ref^{}" means just dereference
437 * tags until you get a non-tag. "ref^0" is a shorthand for
438 * "ref^{commit}". "commit^{tree}" could be used to find the
439 * top-level tree of the given commit.
440 */
441 if (len < 4 || name[len-1] != '}')
442 return -1;
443
444 for (sp = name + len - 1; name <= sp; sp--) {
445 int ch = *sp;
446 if (ch == '{' && name < sp && sp[-1] == '^')
447 break;
448 }
449 if (sp <= name)
450 return -1;
451
452 sp++; /* beginning of type name, or closing brace for empty */
453 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
454 expected_type = OBJ_COMMIT;
455 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
456 expected_type = OBJ_TREE;
457 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
458 expected_type = OBJ_BLOB;
459 else if (sp[0] == '}')
460 expected_type = OBJ_NONE;
461 else
462 return -1;
463
464 if (get_sha1_1(name, sp - name - 2, outer))
465 return -1;
466
467 o = parse_object(outer);
468 if (!o)
469 return -1;
470 if (!expected_type) {
471 o = deref_tag(o, name, sp - name - 2);
472 if (!o || (!o->parsed && !parse_object(o->sha1)))
473 return -1;
474 hashcpy(sha1, o->sha1);
475 }
476 else {
477 /* At this point, the syntax look correct, so
478 * if we do not get the needed object, we should
479 * barf.
480 */
481
482 while (1) {
483 if (!o || (!o->parsed && !parse_object(o->sha1)))
484 return -1;
485 if (o->type == expected_type) {
486 hashcpy(sha1, o->sha1);
487 return 0;
488 }
489 if (o->type == OBJ_TAG)
490 o = ((struct tag*) o)->tagged;
491 else if (o->type == OBJ_COMMIT)
492 o = &(((struct commit *) o)->tree->object);
493 else
494 return error("%.*s: expected %s type, but the object dereferences to %s type",
495 len, name, typename(expected_type),
496 typename(o->type));
497 if (!o->parsed)
498 parse_object(o->sha1);
499 }
500 }
501 return 0;
502 }
503
504 static int get_describe_name(const char *name, int len, unsigned char *sha1)
505 {
506 const char *cp;
507
508 for (cp = name + len - 1; name + 2 <= cp; cp--) {
509 char ch = *cp;
510 if (hexval(ch) & ~0377) {
511 /* We must be looking at g in "SOMETHING-g"
512 * for it to be describe output.
513 */
514 if (ch == 'g' && cp[-1] == '-') {
515 cp++;
516 len -= cp - name;
517 return get_short_sha1(cp, len, sha1, 1);
518 }
519 }
520 }
521 return -1;
522 }
523
524 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
525 {
526 int ret, has_suffix;
527 const char *cp;
528
529 /* "name~3" is "name^^^",
530 * "name~" and "name~0" are name -- not "name^0"!
531 * "name^" is not "name^0"; it is "name^1".
532 */
533 has_suffix = 0;
534 for (cp = name + len - 1; name <= cp; cp--) {
535 int ch = *cp;
536 if ('0' <= ch && ch <= '9')
537 continue;
538 if (ch == '~' || ch == '^')
539 has_suffix = ch;
540 break;
541 }
542
543 if (has_suffix) {
544 int num = 0;
545 int len1 = cp - name;
546 cp++;
547 while (cp < name + len)
548 num = num * 10 + *cp++ - '0';
549 if (has_suffix == '^') {
550 if (!num && len1 == len - 1)
551 num = 1;
552 return get_parent(name, len1, sha1, num);
553 }
554 /* else if (has_suffix == '~') -- goes without saying */
555 return get_nth_ancestor(name, len1, sha1, num);
556 }
557
558 ret = peel_onion(name, len, sha1);
559 if (!ret)
560 return 0;
561
562 ret = get_sha1_basic(name, len, sha1);
563 if (!ret)
564 return 0;
565
566 /* It could be describe output that is "SOMETHING-gXXXX" */
567 ret = get_describe_name(name, len, sha1);
568 if (!ret)
569 return 0;
570
571 return get_short_sha1(name, len, sha1, 0);
572 }
573
574 static int handle_one_ref(const char *path,
575 const unsigned char *sha1, int flag, void *cb_data)
576 {
577 struct commit_list **list = cb_data;
578 struct object *object = parse_object(sha1);
579 if (!object)
580 return 0;
581 if (object->type == OBJ_TAG)
582 object = deref_tag(object, path, strlen(path));
583 if (object->type != OBJ_COMMIT)
584 return 0;
585 insert_by_date((struct commit *)object, list);
586 return 0;
587 }
588
589 /*
590 * This interprets names like ':/Initial revision of "git"' by searching
591 * through history and returning the first commit whose message starts
592 * with the given string.
593 *
594 * For future extension, ':/!' is reserved. If you want to match a message
595 * beginning with a '!', you have to repeat the exclamation mark.
596 */
597
598 #define ONELINE_SEEN (1u<<20)
599 static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
600 {
601 struct commit_list *list = NULL, *backup = NULL, *l;
602 int retval = -1;
603
604 if (prefix[0] == '!') {
605 if (prefix[1] != '!')
606 die ("Invalid search pattern: %s", prefix);
607 prefix++;
608 }
609 if (!save_commit_buffer)
610 return error("Could not expand oneline-name.");
611 for_each_ref(handle_one_ref, &list);
612 for (l = list; l; l = l->next)
613 commit_list_insert(l->item, &backup);
614 while (list) {
615 char *p;
616 struct commit *commit;
617
618 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
619 parse_object(commit->object.sha1);
620 if (!commit->buffer || !(p = strstr(commit->buffer, "\n\n")))
621 continue;
622 if (!prefixcmp(p + 2, prefix)) {
623 hashcpy(sha1, commit->object.sha1);
624 retval = 0;
625 break;
626 }
627 }
628 free_commit_list(list);
629 for (l = backup; l; l = l->next)
630 clear_commit_marks(l->item, ONELINE_SEEN);
631 return retval;
632 }
633
634 /*
635 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
636 * notably "xyz^" for "parent of xyz"
637 */
638 int get_sha1(const char *name, unsigned char *sha1)
639 {
640 unsigned unused;
641 return get_sha1_with_mode(name, sha1, &unused);
642 }
643
644 int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode)
645 {
646 int ret, bracket_depth;
647 int namelen = strlen(name);
648 const char *cp;
649
650 *mode = S_IFINVALID;
651 ret = get_sha1_1(name, namelen, sha1);
652 if (!ret)
653 return ret;
654 /* sha1:path --> object name of path in ent sha1
655 * :path -> object name of path in index
656 * :[0-3]:path -> object name of path in index at stage
657 */
658 if (name[0] == ':') {
659 int stage = 0;
660 struct cache_entry *ce;
661 int pos;
662 if (namelen > 2 && name[1] == '/')
663 return get_sha1_oneline(name + 2, sha1);
664 if (namelen < 3 ||
665 name[2] != ':' ||
666 name[1] < '0' || '3' < name[1])
667 cp = name + 1;
668 else {
669 stage = name[1] - '0';
670 cp = name + 3;
671 }
672 namelen = namelen - (cp - name);
673 if (!active_cache)
674 read_cache();
675 pos = cache_name_pos(cp, namelen);
676 if (pos < 0)
677 pos = -pos - 1;
678 while (pos < active_nr) {
679 ce = active_cache[pos];
680 if (ce_namelen(ce) != namelen ||
681 memcmp(ce->name, cp, namelen))
682 break;
683 if (ce_stage(ce) == stage) {
684 hashcpy(sha1, ce->sha1);
685 *mode = ntohl(ce->ce_mode);
686 return 0;
687 }
688 pos++;
689 }
690 return -1;
691 }
692 for (cp = name, bracket_depth = 0; *cp; cp++) {
693 if (*cp == '{')
694 bracket_depth++;
695 else if (bracket_depth && *cp == '}')
696 bracket_depth--;
697 else if (!bracket_depth && *cp == ':')
698 break;
699 }
700 if (*cp == ':') {
701 unsigned char tree_sha1[20];
702 if (!get_sha1_1(name, cp-name, tree_sha1))
703 return get_tree_entry(tree_sha1, cp+1, sha1,
704 mode);
705 }
706 return ret;
707 }