Documentation: help: describe 'man.viewer' config variable
[git/dscho.git] / sha1_name.c
blob8b6c76f68ed1433caddfa8aab6132db667197433
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"
9 static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
11 struct alternate_object_database *alt;
12 char hex[40];
13 int found = 0;
14 static struct alternate_object_database *fakeent;
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] = '/';
25 fakeent->next = alt_odb_list;
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++;
44 else if (memcmp(hex + 2, de->d_name, 38)) {
45 found = 2;
46 break;
49 closedir(dir);
51 if (found == 1)
52 return get_sha1_hex(hex, sha1) == 0;
53 return found;
56 static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
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;
71 static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
73 struct packed_git *p;
74 const unsigned char *found_sha1 = NULL;
75 int found = 0;
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;
89 now = nth_packed_object_sha1(p, mid);
90 cmp = hashcmp(match, now);
91 if (!cmp) {
92 first = mid;
93 break;
95 if (cmp > 0) {
96 first = mid+1;
97 continue;
99 last = mid;
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++;
112 else if (hashcmp(found_sha1, now)) {
113 found = 2;
114 break;
117 else {
118 /* not even unique within this pack */
119 found = 2;
120 break;
125 if (found == 1)
126 hashcpy(sha1, found_sha1);
127 return found;
130 #define SHORT_NAME_NOT_FOUND (-1)
131 #define SHORT_NAME_AMBIGUOUS (-2)
133 static int find_unique_short_object(int len, char *canonical,
134 unsigned char *res, unsigned char *sha1)
136 int has_unpacked, has_packed;
137 unsigned char unpacked_sha1[20], packed_sha1[20];
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;
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;
157 static int get_short_sha1(const char *name, int len, unsigned char *sha1,
158 int quietly)
160 int i, status;
161 char canonical[40];
162 unsigned char res[20];
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';
179 else
180 return -1;
181 canonical[i] = c;
182 if (!(i & 1))
183 val <<= 4;
184 res[i >> 1] |= val;
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;
193 const char *find_unique_abbrev(const unsigned char *sha1, int len)
195 int status, exists;
196 static char hex[41];
198 exists = has_sha1_file(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 (exists
206 ? !status
207 : status == SHORT_NAME_NOT_FOUND) {
208 hex[len] = 0;
209 return hex;
211 len++;
213 return hex;
216 static int ambiguous_path(const char *path, int len)
218 int slash = 1;
219 int cnt;
221 for (cnt = 0; cnt < len; cnt++) {
222 switch (*path++) {
223 case '\0':
224 break;
225 case '/':
226 if (slash)
227 break;
228 slash = 1;
229 continue;
230 case '.':
231 continue;
232 default:
233 slash = 0;
234 continue;
236 break;
238 return slash;
241 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
243 const char **p, *r;
244 int refs_found = 0;
246 *ref = NULL;
247 for (p = ref_rev_parse_rules; *p; p++) {
248 unsigned char sha1_from_ref[20];
249 unsigned char *this_result;
251 this_result = refs_found ? sha1_from_ref : sha1;
252 r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
253 if (r) {
254 if (!refs_found++)
255 *ref = xstrdup(r);
256 if (!warn_ambiguous_refs)
257 break;
260 return refs_found;
263 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
265 const char **p;
266 int logs_found = 0;
268 *log = NULL;
269 for (p = ref_rev_parse_rules; *p; p++) {
270 struct stat st;
271 unsigned char hash[20];
272 char path[PATH_MAX];
273 const char *ref, *it;
275 strcpy(path, mkpath(*p, len, str));
276 ref = resolve_ref(path, hash, 0, NULL);
277 if (!ref)
278 continue;
279 if (!stat(git_path("logs/%s", path), &st) &&
280 S_ISREG(st.st_mode))
281 it = path;
282 else if (strcmp(ref, path) &&
283 !stat(git_path("logs/%s", ref), &st) &&
284 S_ISREG(st.st_mode))
285 it = ref;
286 else
287 continue;
288 if (!logs_found++) {
289 *log = xstrdup(it);
290 hashcpy(sha1, hash);
292 if (!warn_ambiguous_refs)
293 break;
295 return logs_found;
298 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
300 static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
301 char *real_ref = NULL;
302 int refs_found = 0;
303 int at, reflog_len;
305 if (len == 40 && !get_sha1_hex(str, sha1))
306 return 0;
308 /* basic@{time or number} format to query ref-log */
309 reflog_len = at = 0;
310 if (str[len-1] == '}') {
311 for (at = 0; at < len - 1; at++) {
312 if (str[at] == '@' && str[at+1] == '{') {
313 reflog_len = (len-1) - (at+2);
314 len = at;
315 break;
320 /* Accept only unambiguous ref paths. */
321 if (len && ambiguous_path(str, len))
322 return -1;
324 if (!len && reflog_len) {
325 /* allow "@{...}" to mean the current branch reflog */
326 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
327 } else if (reflog_len)
328 refs_found = dwim_log(str, len, sha1, &real_ref);
329 else
330 refs_found = dwim_ref(str, len, sha1, &real_ref);
332 if (!refs_found)
333 return -1;
335 if (warn_ambiguous_refs && refs_found > 1)
336 fprintf(stderr, warning, len, str);
338 if (reflog_len) {
339 int nth, i;
340 unsigned long at_time;
341 unsigned long co_time;
342 int co_tz, co_cnt;
344 /* Is it asking for N-th entry, or approxidate? */
345 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
346 char ch = str[at+2+i];
347 if ('0' <= ch && ch <= '9')
348 nth = nth * 10 + ch - '0';
349 else
350 nth = -1;
352 if (0 <= nth)
353 at_time = 0;
354 else
355 at_time = approxidate(str + at + 2);
356 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
357 &co_time, &co_tz, &co_cnt)) {
358 if (at_time)
359 fprintf(stderr,
360 "warning: Log for '%.*s' only goes "
361 "back to %s.\n", len, str,
362 show_date(co_time, co_tz, DATE_RFC2822));
363 else
364 fprintf(stderr,
365 "warning: Log for '%.*s' only has "
366 "%d entries.\n", len, str, co_cnt);
370 free(real_ref);
371 return 0;
374 static int get_sha1_1(const char *name, int len, unsigned char *sha1);
376 static int get_parent(const char *name, int len,
377 unsigned char *result, int idx)
379 unsigned char sha1[20];
380 int ret = get_sha1_1(name, len, sha1);
381 struct commit *commit;
382 struct commit_list *p;
384 if (ret)
385 return ret;
386 commit = lookup_commit_reference(sha1);
387 if (!commit)
388 return -1;
389 if (parse_commit(commit))
390 return -1;
391 if (!idx) {
392 hashcpy(result, commit->object.sha1);
393 return 0;
395 p = commit->parents;
396 while (p) {
397 if (!--idx) {
398 hashcpy(result, p->item->object.sha1);
399 return 0;
401 p = p->next;
403 return -1;
406 static int get_nth_ancestor(const char *name, int len,
407 unsigned char *result, int generation)
409 unsigned char sha1[20];
410 int ret = get_sha1_1(name, len, sha1);
411 if (ret)
412 return ret;
414 while (generation--) {
415 struct commit *commit = lookup_commit_reference(sha1);
417 if (!commit || parse_commit(commit) || !commit->parents)
418 return -1;
419 hashcpy(sha1, commit->parents->item->object.sha1);
421 hashcpy(result, sha1);
422 return 0;
425 struct object *peel_to_type(const char *name, int namelen,
426 struct object *o, enum object_type expected_type)
428 if (name && !namelen)
429 namelen = strlen(name);
430 if (!o) {
431 unsigned char sha1[20];
432 if (get_sha1_1(name, namelen, sha1))
433 return NULL;
434 o = parse_object(sha1);
436 while (1) {
437 if (!o || (!o->parsed && !parse_object(o->sha1)))
438 return NULL;
439 if (o->type == expected_type)
440 return o;
441 if (o->type == OBJ_TAG)
442 o = ((struct tag*) o)->tagged;
443 else if (o->type == OBJ_COMMIT)
444 o = &(((struct commit *) o)->tree->object);
445 else {
446 if (name)
447 error("%.*s: expected %s type, but the object "
448 "dereferences to %s type",
449 namelen, name, typename(expected_type),
450 typename(o->type));
451 return NULL;
456 static int peel_onion(const char *name, int len, unsigned char *sha1)
458 unsigned char outer[20];
459 const char *sp;
460 unsigned int expected_type = 0;
461 struct object *o;
464 * "ref^{type}" dereferences ref repeatedly until you cannot
465 * dereference anymore, or you get an object of given type,
466 * whichever comes first. "ref^{}" means just dereference
467 * tags until you get a non-tag. "ref^0" is a shorthand for
468 * "ref^{commit}". "commit^{tree}" could be used to find the
469 * top-level tree of the given commit.
471 if (len < 4 || name[len-1] != '}')
472 return -1;
474 for (sp = name + len - 1; name <= sp; sp--) {
475 int ch = *sp;
476 if (ch == '{' && name < sp && sp[-1] == '^')
477 break;
479 if (sp <= name)
480 return -1;
482 sp++; /* beginning of type name, or closing brace for empty */
483 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
484 expected_type = OBJ_COMMIT;
485 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
486 expected_type = OBJ_TREE;
487 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
488 expected_type = OBJ_BLOB;
489 else if (sp[0] == '}')
490 expected_type = OBJ_NONE;
491 else
492 return -1;
494 if (get_sha1_1(name, sp - name - 2, outer))
495 return -1;
497 o = parse_object(outer);
498 if (!o)
499 return -1;
500 if (!expected_type) {
501 o = deref_tag(o, name, sp - name - 2);
502 if (!o || (!o->parsed && !parse_object(o->sha1)))
503 return -1;
504 hashcpy(sha1, o->sha1);
506 else {
508 * At this point, the syntax look correct, so
509 * if we do not get the needed object, we should
510 * barf.
512 o = peel_to_type(name, len, o, expected_type);
513 if (o) {
514 hashcpy(sha1, o->sha1);
515 return 0;
517 return -1;
519 return 0;
522 static int get_describe_name(const char *name, int len, unsigned char *sha1)
524 const char *cp;
526 for (cp = name + len - 1; name + 2 <= cp; cp--) {
527 char ch = *cp;
528 if (hexval(ch) & ~0377) {
529 /* We must be looking at g in "SOMETHING-g"
530 * for it to be describe output.
532 if (ch == 'g' && cp[-1] == '-') {
533 cp++;
534 len -= cp - name;
535 return get_short_sha1(cp, len, sha1, 1);
539 return -1;
542 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
544 int ret, has_suffix;
545 const char *cp;
547 /* "name~3" is "name^^^",
548 * "name~" and "name~0" are name -- not "name^0"!
549 * "name^" is not "name^0"; it is "name^1".
551 has_suffix = 0;
552 for (cp = name + len - 1; name <= cp; cp--) {
553 int ch = *cp;
554 if ('0' <= ch && ch <= '9')
555 continue;
556 if (ch == '~' || ch == '^')
557 has_suffix = ch;
558 break;
561 if (has_suffix) {
562 int num = 0;
563 int len1 = cp - name;
564 cp++;
565 while (cp < name + len)
566 num = num * 10 + *cp++ - '0';
567 if (has_suffix == '^') {
568 if (!num && len1 == len - 1)
569 num = 1;
570 return get_parent(name, len1, sha1, num);
572 /* else if (has_suffix == '~') -- goes without saying */
573 return get_nth_ancestor(name, len1, sha1, num);
576 ret = peel_onion(name, len, sha1);
577 if (!ret)
578 return 0;
580 ret = get_sha1_basic(name, len, sha1);
581 if (!ret)
582 return 0;
584 /* It could be describe output that is "SOMETHING-gXXXX" */
585 ret = get_describe_name(name, len, sha1);
586 if (!ret)
587 return 0;
589 return get_short_sha1(name, len, sha1, 0);
592 static int handle_one_ref(const char *path,
593 const unsigned char *sha1, int flag, void *cb_data)
595 struct commit_list **list = cb_data;
596 struct object *object = parse_object(sha1);
597 if (!object)
598 return 0;
599 if (object->type == OBJ_TAG) {
600 object = deref_tag(object, path, strlen(path));
601 if (!object)
602 return 0;
604 if (object->type != OBJ_COMMIT)
605 return 0;
606 insert_by_date((struct commit *)object, list);
607 return 0;
611 * This interprets names like ':/Initial revision of "git"' by searching
612 * through history and returning the first commit whose message starts
613 * with the given string.
615 * For future extension, ':/!' is reserved. If you want to match a message
616 * beginning with a '!', you have to repeat the exclamation mark.
619 #define ONELINE_SEEN (1u<<20)
620 static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
622 struct commit_list *list = NULL, *backup = NULL, *l;
623 int retval = -1;
624 char *temp_commit_buffer = NULL;
626 if (prefix[0] == '!') {
627 if (prefix[1] != '!')
628 die ("Invalid search pattern: %s", prefix);
629 prefix++;
631 for_each_ref(handle_one_ref, &list);
632 for (l = list; l; l = l->next)
633 commit_list_insert(l->item, &backup);
634 while (list) {
635 char *p;
636 struct commit *commit;
637 enum object_type type;
638 unsigned long size;
640 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
641 if (!parse_object(commit->object.sha1))
642 continue;
643 free(temp_commit_buffer);
644 if (commit->buffer)
645 p = commit->buffer;
646 else {
647 p = read_sha1_file(commit->object.sha1, &type, &size);
648 if (!p)
649 continue;
650 temp_commit_buffer = p;
652 if (!(p = strstr(p, "\n\n")))
653 continue;
654 if (!prefixcmp(p + 2, prefix)) {
655 hashcpy(sha1, commit->object.sha1);
656 retval = 0;
657 break;
660 free(temp_commit_buffer);
661 free_commit_list(list);
662 for (l = backup; l; l = l->next)
663 clear_commit_marks(l->item, ONELINE_SEEN);
664 return retval;
668 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
669 * notably "xyz^" for "parent of xyz"
671 int get_sha1(const char *name, unsigned char *sha1)
673 unsigned unused;
674 return get_sha1_with_mode(name, sha1, &unused);
677 int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode)
679 int ret, bracket_depth;
680 int namelen = strlen(name);
681 const char *cp;
683 *mode = S_IFINVALID;
684 ret = get_sha1_1(name, namelen, sha1);
685 if (!ret)
686 return ret;
687 /* sha1:path --> object name of path in ent sha1
688 * :path -> object name of path in index
689 * :[0-3]:path -> object name of path in index at stage
691 if (name[0] == ':') {
692 int stage = 0;
693 struct cache_entry *ce;
694 int pos;
695 if (namelen > 2 && name[1] == '/')
696 return get_sha1_oneline(name + 2, sha1);
697 if (namelen < 3 ||
698 name[2] != ':' ||
699 name[1] < '0' || '3' < name[1])
700 cp = name + 1;
701 else {
702 stage = name[1] - '0';
703 cp = name + 3;
705 namelen = namelen - (cp - name);
706 if (!active_cache)
707 read_cache();
708 pos = cache_name_pos(cp, namelen);
709 if (pos < 0)
710 pos = -pos - 1;
711 while (pos < active_nr) {
712 ce = active_cache[pos];
713 if (ce_namelen(ce) != namelen ||
714 memcmp(ce->name, cp, namelen))
715 break;
716 if (ce_stage(ce) == stage) {
717 hashcpy(sha1, ce->sha1);
718 *mode = ce->ce_mode;
719 return 0;
721 pos++;
723 return -1;
725 for (cp = name, bracket_depth = 0; *cp; cp++) {
726 if (*cp == '{')
727 bracket_depth++;
728 else if (bracket_depth && *cp == '}')
729 bracket_depth--;
730 else if (!bracket_depth && *cp == ':')
731 break;
733 if (*cp == ':') {
734 unsigned char tree_sha1[20];
735 if (!get_sha1_1(name, cp-name, tree_sha1))
736 return get_tree_entry(tree_sha1, cp+1, sha1,
737 mode);
739 return ret;