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[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
e86eb666 238int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
9938af6a 239{
c51d1369 240 static const char *fmt[] = {
84a9b58c 241 "%.*s",
c51d1369
JH
242 "refs/%.*s",
243 "refs/tags/%.*s",
244 "refs/heads/%.*s",
245 "refs/remotes/%.*s",
246 "refs/remotes/%.*s/HEAD",
9938af6a
JH
247 NULL
248 };
e86eb666
JH
249 const char **p, *r;
250 int refs_found = 0;
251
252 *ref = NULL;
253 for (p = fmt; *p; p++) {
254 unsigned char sha1_from_ref[20];
255 unsigned char *this_result;
256
257 this_result = refs_found ? sha1_from_ref : sha1;
258 r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
259 if (r) {
260 if (!refs_found++)
261 *ref = xstrdup(r);
262 if (!warn_ambiguous_refs)
263 break;
264 }
265 }
266 return refs_found;
267}
268
269static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
270{
d556fae2 271 static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
ed378ec7 272 char *real_ref = NULL;
ab2a1a32
JH
273 int refs_found = 0;
274 int at, reflog_len;
9938af6a 275
3c3852e3 276 if (len == 40 && !get_sha1_hex(str, sha1))
9938af6a
JH
277 return 0;
278
ab2a1a32 279 /* basic@{time or number} format to query ref-log */
694500ed 280 reflog_len = at = 0;
ab2a1a32
JH
281 if (str[len-1] == '}') {
282 for (at = 1; at < len - 1; at++) {
283 if (str[at] == '@' && str[at+1] == '{') {
284 reflog_len = (len-1) - (at+2);
285 len = at;
286 break;
287 }
d556fae2
SP
288 }
289 }
290
af13cdf2 291 /* Accept only unambiguous ref paths. */
6677c466 292 if (ambiguous_path(str, len))
af13cdf2
LT
293 return -1;
294
e86eb666 295 refs_found = dwim_ref(str, len, sha1, &real_ref);
d556fae2
SP
296
297 if (!refs_found)
298 return -1;
299
300 if (warn_ambiguous_refs && refs_found > 1)
301 fprintf(stderr, warning, len, str);
302
ab2a1a32
JH
303 if (reflog_len) {
304 /* Is it asking for N-th entry, or approxidate? */
305 int nth, i;
306 unsigned long at_time;
16d7cc90
JH
307 unsigned long co_time;
308 int co_tz, co_cnt;
309
ab2a1a32
JH
310 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
311 char ch = str[at+2+i];
312 if ('0' <= ch && ch <= '9')
313 nth = nth * 10 + ch - '0';
314 else
315 nth = -1;
316 }
317 if (0 <= nth)
318 at_time = 0;
319 else
320 at_time = approxidate(str + at + 2);
16d7cc90
JH
321 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
322 &co_time, &co_tz, &co_cnt)) {
323 if (at_time)
324 fprintf(stderr,
325 "warning: Log for '%.*s' only goes "
326 "back to %s.\n", len, str,
327 show_rfc2822_date(co_time, co_tz));
328 else
329 fprintf(stderr,
330 "warning: Log for '%.*s' only has "
331 "%d entries.\n", len, str, co_cnt);
332 }
d556fae2
SP
333 }
334
ed378ec7 335 free(real_ref);
d556fae2 336 return 0;
9938af6a
JH
337}
338
339static int get_sha1_1(const char *name, int len, unsigned char *sha1);
340
341static int get_parent(const char *name, int len,
342 unsigned char *result, int idx)
343{
344 unsigned char sha1[20];
345 int ret = get_sha1_1(name, len, sha1);
346 struct commit *commit;
347 struct commit_list *p;
348
349 if (ret)
350 return ret;
351 commit = lookup_commit_reference(sha1);
352 if (!commit)
353 return -1;
354 if (parse_commit(commit))
355 return -1;
356 if (!idx) {
e702496e 357 hashcpy(result, commit->object.sha1);
9938af6a
JH
358 return 0;
359 }
360 p = commit->parents;
361 while (p) {
362 if (!--idx) {
e702496e 363 hashcpy(result, p->item->object.sha1);
9938af6a
JH
364 return 0;
365 }
366 p = p->next;
367 }
368 return -1;
369}
370
4f7599ac
JH
371static int get_nth_ancestor(const char *name, int len,
372 unsigned char *result, int generation)
373{
374 unsigned char sha1[20];
375 int ret = get_sha1_1(name, len, sha1);
376 if (ret)
377 return ret;
378
379 while (generation--) {
380 struct commit *commit = lookup_commit_reference(sha1);
381
382 if (!commit || parse_commit(commit) || !commit->parents)
383 return -1;
e702496e 384 hashcpy(sha1, commit->parents->item->object.sha1);
4f7599ac 385 }
e702496e 386 hashcpy(result, sha1);
4f7599ac
JH
387 return 0;
388}
389
5385f52d
JH
390static int peel_onion(const char *name, int len, unsigned char *sha1)
391{
392 unsigned char outer[20];
393 const char *sp;
885a86ab 394 unsigned int expected_type = 0;
5385f52d
JH
395 struct object *o;
396
397 /*
398 * "ref^{type}" dereferences ref repeatedly until you cannot
399 * dereference anymore, or you get an object of given type,
400 * whichever comes first. "ref^{}" means just dereference
401 * tags until you get a non-tag. "ref^0" is a shorthand for
402 * "ref^{commit}". "commit^{tree}" could be used to find the
403 * top-level tree of the given commit.
404 */
405 if (len < 4 || name[len-1] != '}')
406 return -1;
407
408 for (sp = name + len - 1; name <= sp; sp--) {
409 int ch = *sp;
410 if (ch == '{' && name < sp && sp[-1] == '^')
411 break;
412 }
413 if (sp <= name)
414 return -1;
415
416 sp++; /* beginning of type name, or closing brace for empty */
417 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
1974632c 418 expected_type = OBJ_COMMIT;
5385f52d 419 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
1974632c 420 expected_type = OBJ_TREE;
5385f52d 421 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
1974632c 422 expected_type = OBJ_BLOB;
5385f52d 423 else if (sp[0] == '}')
1974632c 424 expected_type = OBJ_NONE;
5385f52d
JH
425 else
426 return -1;
427
428 if (get_sha1_1(name, sp - name - 2, outer))
429 return -1;
430
431 o = parse_object(outer);
432 if (!o)
433 return -1;
885a86ab 434 if (!expected_type) {
9534f40b 435 o = deref_tag(o, name, sp - name - 2);
6e1c6c10
JH
436 if (!o || (!o->parsed && !parse_object(o->sha1)))
437 return -1;
e702496e 438 hashcpy(sha1, o->sha1);
5385f52d
JH
439 }
440 else {
441 /* At this point, the syntax look correct, so
442 * if we do not get the needed object, we should
443 * barf.
444 */
445
446 while (1) {
6e1c6c10 447 if (!o || (!o->parsed && !parse_object(o->sha1)))
5385f52d 448 return -1;
885a86ab 449 if (o->type == expected_type) {
e702496e 450 hashcpy(sha1, o->sha1);
5385f52d
JH
451 return 0;
452 }
1974632c 453 if (o->type == OBJ_TAG)
5385f52d 454 o = ((struct tag*) o)->tagged;
1974632c 455 else if (o->type == OBJ_COMMIT)
5385f52d
JH
456 o = &(((struct commit *) o)->tree->object);
457 else
458 return error("%.*s: expected %s type, but the object dereferences to %s type",
885a86ab
LT
459 len, name, typename(expected_type),
460 typename(o->type));
5385f52d
JH
461 if (!o->parsed)
462 parse_object(o->sha1);
463 }
464 }
465 return 0;
466}
467
7dd45e15
JH
468static int get_describe_name(const char *name, int len, unsigned char *sha1)
469{
470 const char *cp;
471
472 for (cp = name + len - 1; name + 2 <= cp; cp--) {
473 char ch = *cp;
474 if (hexval(ch) & ~0377) {
475 /* We must be looking at g in "SOMETHING-g"
476 * for it to be describe output.
477 */
478 if (ch == 'g' && cp[-1] == '-') {
479 cp++;
480 len -= cp - name;
481 return get_short_sha1(cp, len, sha1, 1);
482 }
483 }
484 }
485 return -1;
486}
487
9938af6a
JH
488static int get_sha1_1(const char *name, int len, unsigned char *sha1)
489{
0601dbe1 490 int ret, has_suffix;
4f7599ac 491 const char *cp;
9938af6a 492
4f7599ac 493 /* "name~3" is "name^^^",
4f7599ac 494 * "name~" and "name~0" are name -- not "name^0"!
0601dbe1 495 * "name^" is not "name^0"; it is "name^1".
4f7599ac 496 */
0601dbe1 497 has_suffix = 0;
4f7599ac
JH
498 for (cp = name + len - 1; name <= cp; cp--) {
499 int ch = *cp;
500 if ('0' <= ch && ch <= '9')
501 continue;
0601dbe1
JH
502 if (ch == '~' || ch == '^')
503 has_suffix = ch;
4f7599ac
JH
504 break;
505 }
0601dbe1
JH
506
507 if (has_suffix) {
508 int num = 0;
4f7599ac
JH
509 int len1 = cp - name;
510 cp++;
511 while (cp < name + len)
0601dbe1
JH
512 num = num * 10 + *cp++ - '0';
513 if (has_suffix == '^') {
514 if (!num && len1 == len - 1)
515 num = 1;
516 return get_parent(name, len1, sha1, num);
517 }
518 /* else if (has_suffix == '~') -- goes without saying */
519 return get_nth_ancestor(name, len1, sha1, num);
4f7599ac
JH
520 }
521
5385f52d
JH
522 ret = peel_onion(name, len, sha1);
523 if (!ret)
524 return 0;
525
9938af6a
JH
526 ret = get_sha1_basic(name, len, sha1);
527 if (!ret)
528 return 0;
7dd45e15
JH
529
530 /* It could be describe output that is "SOMETHING-gXXXX" */
531 ret = get_describe_name(name, len, sha1);
532 if (!ret)
533 return 0;
534
013f276e 535 return get_short_sha1(name, len, sha1, 0);
9938af6a
JH
536}
537
538/*
539 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
540 * notably "xyz^" for "parent of xyz"
541 */
542int get_sha1(const char *name, unsigned char *sha1)
543{
cce91a2c 544 int ret, bracket_depth;
041a7308 545 unsigned unused;
73b0e5af
JH
546 int namelen = strlen(name);
547 const char *cp;
5119602a 548
99a19b43 549 prepare_alt_odb();
73b0e5af
JH
550 ret = get_sha1_1(name, namelen, sha1);
551 if (!ret)
552 return ret;
553 /* sha1:path --> object name of path in ent sha1
554 * :path -> object name of path in index
555 * :[0-3]:path -> object name of path in index at stage
556 */
557 if (name[0] == ':') {
558 int stage = 0;
559 struct cache_entry *ce;
560 int pos;
561 if (namelen < 3 ||
562 name[2] != ':' ||
563 name[1] < '0' || '3' < name[1])
564 cp = name + 1;
565 else {
566 stage = name[1] - '0';
567 cp = name + 3;
5119602a 568 }
73b0e5af
JH
569 namelen = namelen - (cp - name);
570 if (!active_cache)
571 read_cache();
572 if (active_nr < 0)
573 return -1;
574 pos = cache_name_pos(cp, namelen);
575 if (pos < 0)
576 pos = -pos - 1;
577 while (pos < active_nr) {
578 ce = active_cache[pos];
579 if (ce_namelen(ce) != namelen ||
580 memcmp(ce->name, cp, namelen))
581 break;
582 if (ce_stage(ce) == stage) {
e702496e 583 hashcpy(sha1, ce->sha1);
73b0e5af
JH
584 return 0;
585 }
e7cef45f 586 pos++;
73b0e5af
JH
587 }
588 return -1;
589 }
cce91a2c
SP
590 for (cp = name, bracket_depth = 0; *cp; cp++) {
591 if (*cp == '{')
592 bracket_depth++;
593 else if (bracket_depth && *cp == '}')
594 bracket_depth--;
595 else if (!bracket_depth && *cp == ':')
596 break;
597 }
598 if (*cp == ':') {
73b0e5af
JH
599 unsigned char tree_sha1[20];
600 if (!get_sha1_1(name, cp-name, tree_sha1))
601 return get_tree_entry(tree_sha1, cp+1, sha1,
602 &unused);
5119602a
LT
603 }
604 return ret;
9938af6a 605}