ae31851900cd3b7ef753e1a2254f9a4f1a5fcc8d
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"
8static 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 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 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}
55static 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}
70static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
72{
73 struct packed_git *p;
74 unsigned char found_sha1[20];
75 int found = 0;
76 prepare_packed_git();
78 for (p = packed_git; p && found < 2; p = p->next) {
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 nth_packed_object_sha1(p, mid, now);
87 cmp = hashcmp(match, now);
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) {
99 unsigned char now[20], next[20];
100 nth_packed_object_sha1(p, first, now);
101 if (match_sha(len, match, now)) {
102 if (nth_packed_object_sha1(p, first+1, next) ||
103 !match_sha(len, match, next)) {
104 /* unique within this pack */
105 if (!found) {
106 hashcpy(found_sha1, now);
107 found++;
108 }
109 else if (hashcmp(found_sha1, now)) {
110 found = 2;
111 break;
112 }
113 }
114 else {
115 /* not even unique within this pack */
116 found = 2;
117 break;
118 }
119 }
120 }
121 }
122 if (found == 1)
123 hashcpy(sha1, found_sha1);
124 return found;
125}
126#define SHORT_NAME_NOT_FOUND (-1)
128#define SHORT_NAME_AMBIGUOUS (-2)
129static 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 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)
139 return SHORT_NAME_NOT_FOUND;
140 if (1 < has_unpacked || 1 < has_packed)
141 return SHORT_NAME_AMBIGUOUS;
142 if (has_unpacked != has_packed) {
143 hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
144 return 0;
145 }
146 /* Both have unique ones -- do they match? */
147 if (hashcmp(packed_sha1, unpacked_sha1))
148 return SHORT_NAME_AMBIGUOUS;
149 hashcpy(sha1, packed_sha1);
150 return 0;
151}
152static int get_short_sha1(const char *name, int len, unsigned char *sha1,
154 int quietly)
155{
156 int i, status;
157 char canonical[40];
158 unsigned char res[20];
159 if (len < MINIMUM_ABBREV || len > 40)
161 return -1;
162 hashclr(res);
163 memset(canonical, 'x', 40);
164 for (i = 0; i < len ;i++) {
165 unsigned char c = name[i];
166 unsigned char val;
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 }
182 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}
188const char *find_unique_abbrev(const unsigned char *sha1, int len)
190{
191 int status, is_null;
192 static char hex[41];
193 is_null = is_null_sha1(sha1);
195 memcpy(hex, sha1_to_hex(sha1), 40);
196 if (len == 40 || !len)
197 return hex;
198 while (len < 40) {
199 unsigned char sha1_ret[20];
200 status = get_short_sha1(hex, len, sha1_ret, 1);
201 if (!status ||
202 (is_null && status != SHORT_NAME_AMBIGUOUS)) {
203 hex[len] = 0;
204 return hex;
205 }
206 if (status != SHORT_NAME_AMBIGUOUS)
207 return NULL;
208 len++;
209 }
210 return NULL;
211}
212static int ambiguous_path(const char *path, int len)
214{
215 int slash = 1;
216 int cnt;
217 for (cnt = 0; cnt < len; cnt++) {
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 }
233 break;
234 }
235 return slash;
236}
237int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
239{
240 static const char *fmt[] = {
241 "%.*s",
242 "refs/%.*s",
243 "refs/tags/%.*s",
244 "refs/heads/%.*s",
245 "refs/remotes/%.*s",
246 "refs/remotes/%.*s/HEAD",
247 NULL
248 };
249 const char **p, *r;
250 int refs_found = 0;
251 *ref = NULL;
253 for (p = fmt; *p; p++) {
254 unsigned char sha1_from_ref[20];
255 unsigned char *this_result;
256 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}
268static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
270{
271 static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
272 char *real_ref = NULL;
273 int refs_found = 0;
274 int at, reflog_len;
275 if (len == 40 && !get_sha1_hex(str, sha1))
277 return 0;
278 /* basic@{time or number} format to query ref-log */
280 reflog_len = at = 0;
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 }
288 }
289 }
290 /* Accept only unambiguous ref paths. */
292 if (ambiguous_path(str, len))
293 return -1;
294 refs_found = dwim_ref(str, len, sha1, &real_ref);
296 if (!refs_found)
298 return -1;
299 if (warn_ambiguous_refs && refs_found > 1)
301 fprintf(stderr, warning, len, str);
302 if (reflog_len) {
304 /* Is it asking for N-th entry, or approxidate? */
305 int nth, i;
306 unsigned long at_time;
307 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
308 char ch = str[at+2+i];
309 if ('0' <= ch && ch <= '9')
310 nth = nth * 10 + ch - '0';
311 else
312 nth = -1;
313 }
314 if (0 <= nth)
315 at_time = 0;
316 else
317 at_time = approxidate(str + at + 2);
318 read_ref_at(real_ref, at_time, nth, sha1);
319 }
320 free(real_ref);
322 return 0;
323}
324static int get_sha1_1(const char *name, int len, unsigned char *sha1);
326static int get_parent(const char *name, int len,
328 unsigned char *result, int idx)
329{
330 unsigned char sha1[20];
331 int ret = get_sha1_1(name, len, sha1);
332 struct commit *commit;
333 struct commit_list *p;
334 if (ret)
336 return ret;
337 commit = lookup_commit_reference(sha1);
338 if (!commit)
339 return -1;
340 if (parse_commit(commit))
341 return -1;
342 if (!idx) {
343 hashcpy(result, commit->object.sha1);
344 return 0;
345 }
346 p = commit->parents;
347 while (p) {
348 if (!--idx) {
349 hashcpy(result, p->item->object.sha1);
350 return 0;
351 }
352 p = p->next;
353 }
354 return -1;
355}
356static int get_nth_ancestor(const char *name, int len,
358 unsigned char *result, int generation)
359{
360 unsigned char sha1[20];
361 int ret = get_sha1_1(name, len, sha1);
362 if (ret)
363 return ret;
364 while (generation--) {
366 struct commit *commit = lookup_commit_reference(sha1);
367 if (!commit || parse_commit(commit) || !commit->parents)
369 return -1;
370 hashcpy(sha1, commit->parents->item->object.sha1);
371 }
372 hashcpy(result, sha1);
373 return 0;
374}
375static int peel_onion(const char *name, int len, unsigned char *sha1)
377{
378 unsigned char outer[20];
379 const char *sp;
380 unsigned int expected_type = 0;
381 struct object *o;
382 /*
384 * "ref^{type}" dereferences ref repeatedly until you cannot
385 * dereference anymore, or you get an object of given type,
386 * whichever comes first. "ref^{}" means just dereference
387 * tags until you get a non-tag. "ref^0" is a shorthand for
388 * "ref^{commit}". "commit^{tree}" could be used to find the
389 * top-level tree of the given commit.
390 */
391 if (len < 4 || name[len-1] != '}')
392 return -1;
393 for (sp = name + len - 1; name <= sp; sp--) {
395 int ch = *sp;
396 if (ch == '{' && name < sp && sp[-1] == '^')
397 break;
398 }
399 if (sp <= name)
400 return -1;
401 sp++; /* beginning of type name, or closing brace for empty */
403 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
404 expected_type = OBJ_COMMIT;
405 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
406 expected_type = OBJ_TREE;
407 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
408 expected_type = OBJ_BLOB;
409 else if (sp[0] == '}')
410 expected_type = OBJ_NONE;
411 else
412 return -1;
413 if (get_sha1_1(name, sp - name - 2, outer))
415 return -1;
416 o = parse_object(outer);
418 if (!o)
419 return -1;
420 if (!expected_type) {
421 o = deref_tag(o, name, sp - name - 2);
422 if (!o || (!o->parsed && !parse_object(o->sha1)))
423 return -1;
424 hashcpy(sha1, o->sha1);
425 }
426 else {
427 /* At this point, the syntax look correct, so
428 * if we do not get the needed object, we should
429 * barf.
430 */
431 while (1) {
433 if (!o || (!o->parsed && !parse_object(o->sha1)))
434 return -1;
435 if (o->type == expected_type) {
436 hashcpy(sha1, o->sha1);
437 return 0;
438 }
439 if (o->type == OBJ_TAG)
440 o = ((struct tag*) o)->tagged;
441 else if (o->type == OBJ_COMMIT)
442 o = &(((struct commit *) o)->tree->object);
443 else
444 return error("%.*s: expected %s type, but the object dereferences to %s type",
445 len, name, typename(expected_type),
446 typename(o->type));
447 if (!o->parsed)
448 parse_object(o->sha1);
449 }
450 }
451 return 0;
452}
453static int get_describe_name(const char *name, int len, unsigned char *sha1)
455{
456 const char *cp;
457 for (cp = name + len - 1; name + 2 <= cp; cp--) {
459 char ch = *cp;
460 if (hexval(ch) & ~0377) {
461 /* We must be looking at g in "SOMETHING-g"
462 * for it to be describe output.
463 */
464 if (ch == 'g' && cp[-1] == '-') {
465 cp++;
466 len -= cp - name;
467 return get_short_sha1(cp, len, sha1, 1);
468 }
469 }
470 }
471 return -1;
472}
473static int get_sha1_1(const char *name, int len, unsigned char *sha1)
475{
476 int ret, has_suffix;
477 const char *cp;
478 /* "name~3" is "name^^^",
480 * "name~" and "name~0" are name -- not "name^0"!
481 * "name^" is not "name^0"; it is "name^1".
482 */
483 has_suffix = 0;
484 for (cp = name + len - 1; name <= cp; cp--) {
485 int ch = *cp;
486 if ('0' <= ch && ch <= '9')
487 continue;
488 if (ch == '~' || ch == '^')
489 has_suffix = ch;
490 break;
491 }
492 if (has_suffix) {
494 int num = 0;
495 int len1 = cp - name;
496 cp++;
497 while (cp < name + len)
498 num = num * 10 + *cp++ - '0';
499 if (has_suffix == '^') {
500 if (!num && len1 == len - 1)
501 num = 1;
502 return get_parent(name, len1, sha1, num);
503 }
504 /* else if (has_suffix == '~') -- goes without saying */
505 return get_nth_ancestor(name, len1, sha1, num);
506 }
507 ret = peel_onion(name, len, sha1);
509 if (!ret)
510 return 0;
511 ret = get_sha1_basic(name, len, sha1);
513 if (!ret)
514 return 0;
515 /* It could be describe output that is "SOMETHING-gXXXX" */
517 ret = get_describe_name(name, len, sha1);
518 if (!ret)
519 return 0;
520 return get_short_sha1(name, len, sha1, 0);
522}
523/*
525 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
526 * notably "xyz^" for "parent of xyz"
527 */
528int get_sha1(const char *name, unsigned char *sha1)
529{
530 int ret, bracket_depth;
531 unsigned unused;
532 int namelen = strlen(name);
533 const char *cp;
534 prepare_alt_odb();
536 ret = get_sha1_1(name, namelen, sha1);
537 if (!ret)
538 return ret;
539 /* sha1:path --> object name of path in ent sha1
540 * :path -> object name of path in index
541 * :[0-3]:path -> object name of path in index at stage
542 */
543 if (name[0] == ':') {
544 int stage = 0;
545 struct cache_entry *ce;
546 int pos;
547 if (namelen < 3 ||
548 name[2] != ':' ||
549 name[1] < '0' || '3' < name[1])
550 cp = name + 1;
551 else {
552 stage = name[1] - '0';
553 cp = name + 3;
554 }
555 namelen = namelen - (cp - name);
556 if (!active_cache)
557 read_cache();
558 if (active_nr < 0)
559 return -1;
560 pos = cache_name_pos(cp, namelen);
561 if (pos < 0)
562 pos = -pos - 1;
563 while (pos < active_nr) {
564 ce = active_cache[pos];
565 if (ce_namelen(ce) != namelen ||
566 memcmp(ce->name, cp, namelen))
567 break;
568 if (ce_stage(ce) == stage) {
569 hashcpy(sha1, ce->sha1);
570 return 0;
571 }
572 pos++;
573 }
574 return -1;
575 }
576 for (cp = name, bracket_depth = 0; *cp; cp++) {
577 if (*cp == '{')
578 bracket_depth++;
579 else if (bracket_depth && *cp == '}')
580 bracket_depth--;
581 else if (!bracket_depth && *cp == ':')
582 break;
583 }
584 if (*cp == ':') {
585 unsigned char tree_sha1[20];
586 if (!get_sha1_1(name, cp-name, tree_sha1))
587 return get_tree_entry(tree_sha1, cp+1, sha1,
588 &unused);
589 }
590 return ret;
591}