log --reflog: use dwim_log
[git/git.git] / sha1_name.c
CommitLineData
9938af6a 1#include "cache.h"
5385f52d 2#include "tag.h"
9938af6a 3#include "commit.h"
5385f52d
JH
4#include "tree.h"
5#include "blob.h"
f3ab49db 6#include "tree-walk.h"
d556fae2 7#include "refs.h"
9938af6a
JH
8
9static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
10{
99a19b43 11 struct alternate_object_database *alt;
9938af6a 12 char hex[40];
99a19b43
JH
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;
9938af6a 26
9938af6a 27 sprintf(hex, "%.2s", name);
99a19b43 28 for (alt = fakeent; alt && found < 2; alt = alt->next) {
9938af6a 29 struct dirent *de;
99a19b43
JH
30 DIR *dir;
31 sprintf(alt->name, "%.2s/", name);
32 dir = opendir(alt->base);
33 if (!dir)
34 continue;
9938af6a
JH
35 while ((de = readdir(dir)) != NULL) {
36 if (strlen(de->d_name) != 38)
37 continue;
99a19b43 38 if (memcmp(de->d_name, name + 2, len - 2))
9938af6a 39 continue;
99a19b43
JH
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;
9938af6a 46 break;
99a19b43 47 }
9938af6a
JH
48 }
49 closedir(dir);
50 }
51 if (found == 1)
52 return get_sha1_hex(hex, sha1) == 0;
99a19b43 53 return found;
9938af6a
JH
54}
55
56static 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
71static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
72{
73 struct packed_git *p;
99a19b43
JH
74 unsigned char found_sha1[20];
75 int found = 0;
9938af6a
JH
76
77 prepare_packed_git();
99a19b43 78 for (p = packed_git; p && found < 2; p = p->next) {
9938af6a
JH
79 unsigned num = num_packed_objects(p);
80 unsigned first = 0, last = num;
81 while (first < last) {
82 unsigned mid = (first + last) / 2;
83 unsigned char now[20];
84 int cmp;
85
86 nth_packed_object_sha1(p, mid, now);
a89fccd2 87 cmp = hashcmp(match, now);
9938af6a
JH
88 if (!cmp) {
89 first = mid;
90 break;
91 }
92 if (cmp > 0) {
93 first = mid+1;
94 continue;
95 }
96 last = mid;
97 }
98 if (first < num) {
0bc45890 99 unsigned char now[20], next[20];
9938af6a
JH
100 nth_packed_object_sha1(p, first, now);
101 if (match_sha(len, match, now)) {
0bc45890
JH
102 if (nth_packed_object_sha1(p, first+1, next) ||
103 !match_sha(len, match, next)) {
104 /* unique within this pack */
105 if (!found) {
e702496e 106 hashcpy(found_sha1, now);
0bc45890
JH
107 found++;
108 }
a89fccd2 109 else if (hashcmp(found_sha1, now)) {
0bc45890
JH
110 found = 2;
111 break;
112 }
99a19b43 113 }
0bc45890
JH
114 else {
115 /* not even unique within this pack */
99a19b43
JH
116 found = 2;
117 break;
9938af6a
JH
118 }
119 }
120 }
121 }
99a19b43 122 if (found == 1)
e702496e 123 hashcpy(sha1, found_sha1);
99a19b43
JH
124 return found;
125}
126
013f276e
JH
127#define SHORT_NAME_NOT_FOUND (-1)
128#define SHORT_NAME_AMBIGUOUS (-2)
129
99a19b43
JH
130static int find_unique_short_object(int len, char *canonical,
131 unsigned char *res, unsigned char *sha1)
132{
133 int has_unpacked, has_packed;
134 unsigned char unpacked_sha1[20], packed_sha1[20];
135
136 has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
137 has_packed = find_short_packed_object(len, res, packed_sha1);
138 if (!has_unpacked && !has_packed)
013f276e 139 return SHORT_NAME_NOT_FOUND;
99a19b43 140 if (1 < has_unpacked || 1 < has_packed)
013f276e 141 return SHORT_NAME_AMBIGUOUS;
99a19b43 142 if (has_unpacked != has_packed) {
e702496e 143 hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
99a19b43
JH
144 return 0;
145 }
146 /* Both have unique ones -- do they match? */
a89fccd2 147 if (hashcmp(packed_sha1, unpacked_sha1))
e974c9ab 148 return SHORT_NAME_AMBIGUOUS;
e702496e 149 hashcpy(sha1, packed_sha1);
9938af6a
JH
150 return 0;
151}
152
013f276e
JH
153static int get_short_sha1(const char *name, int len, unsigned char *sha1,
154 int quietly)
9938af6a 155{
013f276e 156 int i, status;
9938af6a
JH
157 char canonical[40];
158 unsigned char res[20];
159
8a83157e 160 if (len < MINIMUM_ABBREV || len > 40)
af61c6e0 161 return -1;
a8e0d16d 162 hashclr(res);
9938af6a 163 memset(canonical, 'x', 40);
af61c6e0 164 for (i = 0; i < len ;i++) {
9938af6a
JH
165 unsigned char c = name[i];
166 unsigned char val;
9938af6a
JH
167 if (c >= '0' && c <= '9')
168 val = c - '0';
169 else if (c >= 'a' && c <= 'f')
170 val = c - 'a' + 10;
171 else if (c >= 'A' && c <='F') {
172 val = c - 'A' + 10;
173 c -= 'A' - 'a';
174 }
175 else
176 return -1;
177 canonical[i] = c;
178 if (!(i & 1))
179 val <<= 4;
180 res[i >> 1] |= val;
181 }
99a19b43 182
013f276e
JH
183 status = find_unique_short_object(i, canonical, res, sha1);
184 if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
185 return error("short SHA1 %.*s is ambiguous.", len, canonical);
186 return status;
187}
188
189const char *find_unique_abbrev(const unsigned char *sha1, int len)
190{
297a1aad 191 int status, is_null;
013f276e 192 static char hex[41];
47dd0d59 193
0bef57ee 194 is_null = is_null_sha1(sha1);
013f276e 195 memcpy(hex, sha1_to_hex(sha1), 40);
02c5cba2 196 if (len == 40 || !len)
47dd0d59 197 return hex;
013f276e
JH
198 while (len < 40) {
199 unsigned char sha1_ret[20];
200 status = get_short_sha1(hex, len, sha1_ret, 1);
297a1aad
JH
201 if (!status ||
202 (is_null && status != SHORT_NAME_AMBIGUOUS)) {
013f276e
JH
203 hex[len] = 0;
204 return hex;
205 }
206 if (status != SHORT_NAME_AMBIGUOUS)
207 return NULL;
208 len++;
209 }
210 return NULL;
9938af6a
JH
211}
212
6677c466 213static int ambiguous_path(const char *path, int len)
af13cdf2
LT
214{
215 int slash = 1;
6677c466 216 int cnt;
af13cdf2 217
6677c466 218 for (cnt = 0; cnt < len; cnt++) {
af13cdf2
LT
219 switch (*path++) {
220 case '\0':
221 break;
222 case '/':
223 if (slash)
224 break;
225 slash = 1;
226 continue;
227 case '.':
228 continue;
229 default:
230 slash = 0;
231 continue;
232 }
c054d64e 233 break;
af13cdf2 234 }
6677c466 235 return slash;
af13cdf2
LT
236}
237
f2eba66d
NP
238static const char *ref_fmt[] = {
239 "%.*s",
240 "refs/%.*s",
241 "refs/tags/%.*s",
242 "refs/heads/%.*s",
243 "refs/remotes/%.*s",
244 "refs/remotes/%.*s/HEAD",
245 NULL
246};
247
e86eb666 248int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
9938af6a 249{
e86eb666
JH
250 const char **p, *r;
251 int refs_found = 0;
252
253 *ref = NULL;
f2eba66d 254 for (p = ref_fmt; *p; p++) {
e86eb666
JH
255 unsigned char sha1_from_ref[20];
256 unsigned char *this_result;
257
258 this_result = refs_found ? sha1_from_ref : sha1;
259 r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
260 if (r) {
261 if (!refs_found++)
262 *ref = xstrdup(r);
263 if (!warn_ambiguous_refs)
264 break;
265 }
266 }
267 return refs_found;
268}
269
eb3a4822 270int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
f2eba66d
NP
271{
272 const char **p;
273 int logs_found = 0;
274
275 *log = NULL;
276 for (p = ref_fmt; *p; p++) {
277 struct stat st;
278 char *path = mkpath(*p, len, str);
279 if (!stat(git_path("logs/%s", path), &st) &&
280 S_ISREG(st.st_mode)) {
281 if (!logs_found++) {
282 *log = xstrdup(path);
283 resolve_ref(path, sha1, 0, NULL);
284 }
285 if (!warn_ambiguous_refs)
286 break;
287 }
288 }
289 return logs_found;
290}
291
e86eb666
JH
292static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
293{
d556fae2 294 static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
ed378ec7 295 char *real_ref = NULL;
ab2a1a32
JH
296 int refs_found = 0;
297 int at, reflog_len;
9938af6a 298
3c3852e3 299 if (len == 40 && !get_sha1_hex(str, sha1))
9938af6a
JH
300 return 0;
301
ab2a1a32 302 /* basic@{time or number} format to query ref-log */
694500ed 303 reflog_len = at = 0;
ab2a1a32 304 if (str[len-1] == '}') {
11cf8801 305 for (at = 0; at < len - 1; at++) {
ab2a1a32
JH
306 if (str[at] == '@' && str[at+1] == '{') {
307 reflog_len = (len-1) - (at+2);
308 len = at;
309 break;
310 }
d556fae2
SP
311 }
312 }
313
af13cdf2 314 /* Accept only unambiguous ref paths. */
11cf8801 315 if (len && ambiguous_path(str, len))
af13cdf2
LT
316 return -1;
317
11cf8801
NP
318 if (!len && reflog_len) {
319 /* allow "@{...}" to mean the current branch reflog */
320 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
f2eba66d
NP
321 } else if (reflog_len)
322 refs_found = dwim_log(str, len, sha1, &real_ref);
323 else
11cf8801 324 refs_found = dwim_ref(str, len, sha1, &real_ref);
d556fae2
SP
325
326 if (!refs_found)
327 return -1;
328
329 if (warn_ambiguous_refs && refs_found > 1)
330 fprintf(stderr, warning, len, str);
331
ab2a1a32 332 if (reflog_len) {
ab2a1a32
JH
333 int nth, i;
334 unsigned long at_time;
16d7cc90
JH
335 unsigned long co_time;
336 int co_tz, co_cnt;
337
fe558516 338 /* Is it asking for N-th entry, or approxidate? */
ab2a1a32
JH
339 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
340 char ch = str[at+2+i];
341 if ('0' <= ch && ch <= '9')
342 nth = nth * 10 + ch - '0';
343 else
344 nth = -1;
345 }
346 if (0 <= nth)
347 at_time = 0;
348 else
349 at_time = approxidate(str + at + 2);
16d7cc90
JH
350 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
351 &co_time, &co_tz, &co_cnt)) {
352 if (at_time)
353 fprintf(stderr,
354 "warning: Log for '%.*s' only goes "
355 "back to %s.\n", len, str,
356 show_rfc2822_date(co_time, co_tz));
357 else
358 fprintf(stderr,
359 "warning: Log for '%.*s' only has "
360 "%d entries.\n", len, str, co_cnt);
361 }
d556fae2
SP
362 }
363
ed378ec7 364 free(real_ref);
d556fae2 365 return 0;
9938af6a
JH
366}
367
368static int get_sha1_1(const char *name, int len, unsigned char *sha1);
369
370static int get_parent(const char *name, int len,
371 unsigned char *result, int idx)
372{
373 unsigned char sha1[20];
374 int ret = get_sha1_1(name, len, sha1);
375 struct commit *commit;
376 struct commit_list *p;
377
378 if (ret)
379 return ret;
380 commit = lookup_commit_reference(sha1);
381 if (!commit)
382 return -1;
383 if (parse_commit(commit))
384 return -1;
385 if (!idx) {
e702496e 386 hashcpy(result, commit->object.sha1);
9938af6a
JH
387 return 0;
388 }
389 p = commit->parents;
390 while (p) {
391 if (!--idx) {
e702496e 392 hashcpy(result, p->item->object.sha1);
9938af6a
JH
393 return 0;
394 }
395 p = p->next;
396 }
397 return -1;
398}
399
4f7599ac
JH
400static int get_nth_ancestor(const char *name, int len,
401 unsigned char *result, int generation)
402{
403 unsigned char sha1[20];
404 int ret = get_sha1_1(name, len, sha1);
405 if (ret)
406 return ret;
407
408 while (generation--) {
409 struct commit *commit = lookup_commit_reference(sha1);
410
411 if (!commit || parse_commit(commit) || !commit->parents)
412 return -1;
e702496e 413 hashcpy(sha1, commit->parents->item->object.sha1);
4f7599ac 414 }
e702496e 415 hashcpy(result, sha1);
4f7599ac
JH
416 return 0;
417}
418
5385f52d
JH
419static int peel_onion(const char *name, int len, unsigned char *sha1)
420{
421 unsigned char outer[20];
422 const char *sp;
885a86ab 423 unsigned int expected_type = 0;
5385f52d
JH
424 struct object *o;
425
426 /*
427 * "ref^{type}" dereferences ref repeatedly until you cannot
428 * dereference anymore, or you get an object of given type,
429 * whichever comes first. "ref^{}" means just dereference
430 * tags until you get a non-tag. "ref^0" is a shorthand for
431 * "ref^{commit}". "commit^{tree}" could be used to find the
432 * top-level tree of the given commit.
433 */
434 if (len < 4 || name[len-1] != '}')
435 return -1;
436
437 for (sp = name + len - 1; name <= sp; sp--) {
438 int ch = *sp;
439 if (ch == '{' && name < sp && sp[-1] == '^')
440 break;
441 }
442 if (sp <= name)
443 return -1;
444
445 sp++; /* beginning of type name, or closing brace for empty */
446 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
1974632c 447 expected_type = OBJ_COMMIT;
5385f52d 448 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
1974632c 449 expected_type = OBJ_TREE;
5385f52d 450 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
1974632c 451 expected_type = OBJ_BLOB;
5385f52d 452 else if (sp[0] == '}')
1974632c 453 expected_type = OBJ_NONE;
5385f52d
JH
454 else
455 return -1;
456
457 if (get_sha1_1(name, sp - name - 2, outer))
458 return -1;
459
460 o = parse_object(outer);
461 if (!o)
462 return -1;
885a86ab 463 if (!expected_type) {
9534f40b 464 o = deref_tag(o, name, sp - name - 2);
6e1c6c10
JH
465 if (!o || (!o->parsed && !parse_object(o->sha1)))
466 return -1;
e702496e 467 hashcpy(sha1, o->sha1);
5385f52d
JH
468 }
469 else {
470 /* At this point, the syntax look correct, so
471 * if we do not get the needed object, we should
472 * barf.
473 */
474
475 while (1) {
6e1c6c10 476 if (!o || (!o->parsed && !parse_object(o->sha1)))
5385f52d 477 return -1;
885a86ab 478 if (o->type == expected_type) {
e702496e 479 hashcpy(sha1, o->sha1);
5385f52d
JH
480 return 0;
481 }
1974632c 482 if (o->type == OBJ_TAG)
5385f52d 483 o = ((struct tag*) o)->tagged;
1974632c 484 else if (o->type == OBJ_COMMIT)
5385f52d
JH
485 o = &(((struct commit *) o)->tree->object);
486 else
487 return error("%.*s: expected %s type, but the object dereferences to %s type",
885a86ab
LT
488 len, name, typename(expected_type),
489 typename(o->type));
5385f52d
JH
490 if (!o->parsed)
491 parse_object(o->sha1);
492 }
493 }
494 return 0;
495}
496
7dd45e15
JH
497static int get_describe_name(const char *name, int len, unsigned char *sha1)
498{
499 const char *cp;
500
501 for (cp = name + len - 1; name + 2 <= cp; cp--) {
502 char ch = *cp;
503 if (hexval(ch) & ~0377) {
504 /* We must be looking at g in "SOMETHING-g"
505 * for it to be describe output.
506 */
507 if (ch == 'g' && cp[-1] == '-') {
508 cp++;
509 len -= cp - name;
510 return get_short_sha1(cp, len, sha1, 1);
511 }
512 }
513 }
514 return -1;
515}
516
9938af6a
JH
517static int get_sha1_1(const char *name, int len, unsigned char *sha1)
518{
0601dbe1 519 int ret, has_suffix;
4f7599ac 520 const char *cp;
9938af6a 521
4f7599ac 522 /* "name~3" is "name^^^",
4f7599ac 523 * "name~" and "name~0" are name -- not "name^0"!
0601dbe1 524 * "name^" is not "name^0"; it is "name^1".
4f7599ac 525 */
0601dbe1 526 has_suffix = 0;
4f7599ac
JH
527 for (cp = name + len - 1; name <= cp; cp--) {
528 int ch = *cp;
529 if ('0' <= ch && ch <= '9')
530 continue;
0601dbe1
JH
531 if (ch == '~' || ch == '^')
532 has_suffix = ch;
4f7599ac
JH
533 break;
534 }
0601dbe1
JH
535
536 if (has_suffix) {
537 int num = 0;
4f7599ac
JH
538 int len1 = cp - name;
539 cp++;
540 while (cp < name + len)
0601dbe1
JH
541 num = num * 10 + *cp++ - '0';
542 if (has_suffix == '^') {
543 if (!num && len1 == len - 1)
544 num = 1;
545 return get_parent(name, len1, sha1, num);
546 }
547 /* else if (has_suffix == '~') -- goes without saying */
548 return get_nth_ancestor(name, len1, sha1, num);
4f7599ac
JH
549 }
550
5385f52d
JH
551 ret = peel_onion(name, len, sha1);
552 if (!ret)
553 return 0;
554
9938af6a
JH
555 ret = get_sha1_basic(name, len, sha1);
556 if (!ret)
557 return 0;
7dd45e15
JH
558
559 /* It could be describe output that is "SOMETHING-gXXXX" */
560 ret = get_describe_name(name, len, sha1);
561 if (!ret)
562 return 0;
563
013f276e 564 return get_short_sha1(name, len, sha1, 0);
9938af6a
JH
565}
566
567/*
568 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
569 * notably "xyz^" for "parent of xyz"
570 */
571int get_sha1(const char *name, unsigned char *sha1)
572{
cce91a2c 573 int ret, bracket_depth;
041a7308 574 unsigned unused;
73b0e5af
JH
575 int namelen = strlen(name);
576 const char *cp;
5119602a 577
99a19b43 578 prepare_alt_odb();
73b0e5af
JH
579 ret = get_sha1_1(name, namelen, sha1);
580 if (!ret)
581 return ret;
582 /* sha1:path --> object name of path in ent sha1
583 * :path -> object name of path in index
584 * :[0-3]:path -> object name of path in index at stage
585 */
586 if (name[0] == ':') {
587 int stage = 0;
588 struct cache_entry *ce;
589 int pos;
590 if (namelen < 3 ||
591 name[2] != ':' ||
592 name[1] < '0' || '3' < name[1])
593 cp = name + 1;
594 else {
595 stage = name[1] - '0';
596 cp = name + 3;
5119602a 597 }
73b0e5af
JH
598 namelen = namelen - (cp - name);
599 if (!active_cache)
600 read_cache();
601 if (active_nr < 0)
602 return -1;
603 pos = cache_name_pos(cp, namelen);
604 if (pos < 0)
605 pos = -pos - 1;
606 while (pos < active_nr) {
607 ce = active_cache[pos];
608 if (ce_namelen(ce) != namelen ||
609 memcmp(ce->name, cp, namelen))
610 break;
611 if (ce_stage(ce) == stage) {
e702496e 612 hashcpy(sha1, ce->sha1);
73b0e5af
JH
613 return 0;
614 }
e7cef45f 615 pos++;
73b0e5af
JH
616 }
617 return -1;
618 }
cce91a2c
SP
619 for (cp = name, bracket_depth = 0; *cp; cp++) {
620 if (*cp == '{')
621 bracket_depth++;
622 else if (bracket_depth && *cp == '}')
623 bracket_depth--;
624 else if (!bracket_depth && *cp == ':')
625 break;
626 }
627 if (*cp == ':') {
73b0e5af
JH
628 unsigned char tree_sha1[20];
629 if (!get_sha1_1(name, cp-name, tree_sha1))
630 return get_tree_entry(tree_sha1, cp+1, sha1,
631 &unused);
5119602a
LT
632 }
633 return ret;
9938af6a 634}