7 static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
9 struct alternate_object_database *alt;
12 static struct alternate_object_database *fakeent;
15 const char *objdir = get_object_directory();
16 int objdir_len = strlen(objdir);
17 int entlen = objdir_len + 43;
18 fakeent = xmalloc(sizeof(*fakeent) + entlen);
19 memcpy(fakeent->base, objdir, objdir_len);
20 fakeent->name = fakeent->base + objdir_len + 1;
21 fakeent->name[-1] = '/';
23 fakeent->next = alt_odb_list;
25 sprintf(hex, "%.2s", name);
26 for (alt = fakeent; alt && found < 2; alt = alt->next) {
29 sprintf(alt->name, "%.2s/", name);
30 dir = opendir(alt->base);
33 while ((de = readdir(dir)) != NULL) {
34 if (strlen(de->d_name) != 38)
36 if (memcmp(de->d_name, name + 2, len - 2))
39 memcpy(hex + 2, de->d_name, 38);
42 else if (memcmp(hex + 2, de->d_name, 38)) {
50 return get_sha1_hex(hex, sha1) == 0;
54 static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
69 static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
72 unsigned char found_sha1[20];
76 for (p = packed_git; p && found < 2; p = p->next) {
77 unsigned num = num_packed_objects(p);
78 unsigned first = 0, last = num;
79 while (first < last) {
80 unsigned mid = (first + last) / 2;
81 unsigned char now[20];
84 nth_packed_object_sha1(p, mid, now);
85 cmp = memcmp(match, now, 20);
97 unsigned char now[20], next[20];
98 nth_packed_object_sha1(p, first, now);
99 if (match_sha(len, match, now)) {
100 if (nth_packed_object_sha1(p, first+1, next) ||
101 !match_sha(len, match, next)) {
102 /* unique within this pack */
104 memcpy(found_sha1, now, 20);
107 else if (memcmp(found_sha1, now, 20)) {
113 /* not even unique within this pack */
121 memcpy(sha1, found_sha1, 20);
125 #define SHORT_NAME_NOT_FOUND (-1)
126 #define SHORT_NAME_AMBIGUOUS (-2)
128 static int find_unique_short_object(int len, char *canonical,
129 unsigned char *res, unsigned char *sha1)
131 int has_unpacked, has_packed;
132 unsigned char unpacked_sha1[20], packed_sha1[20];
134 has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
135 has_packed = find_short_packed_object(len, res, packed_sha1);
136 if (!has_unpacked && !has_packed)
137 return SHORT_NAME_NOT_FOUND;
138 if (1 < has_unpacked || 1 < has_packed)
139 return SHORT_NAME_AMBIGUOUS;
140 if (has_unpacked != has_packed) {
141 memcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1), 20);
144 /* Both have unique ones -- do they match? */
145 if (memcmp(packed_sha1, unpacked_sha1, 20))
147 memcpy(sha1, packed_sha1, 20);
151 static int get_short_sha1(const char *name, int len, unsigned char *sha1,
156 unsigned char res[20];
161 memset(canonical, 'x', 40);
162 for (i = 0; i < len ;i++) {
163 unsigned char c = name[i];
165 if (c >= '0' && c <= '9')
167 else if (c >= 'a' && c <= 'f')
169 else if (c >= 'A' && c <='F') {
181 status = find_unique_short_object(i, canonical, res, sha1);
182 if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
183 return error("short SHA1 %.*s is ambiguous.", len, canonical);
187 const char *find_unique_abbrev(const unsigned char *sha1, int len)
191 memcpy(hex, sha1_to_hex(sha1), 40);
193 unsigned char sha1_ret[20];
194 status = get_short_sha1(hex, len, sha1_ret, 1);
199 if (status != SHORT_NAME_AMBIGUOUS)
206 static int ambiguous_path(const char *path, int len)
211 for (cnt = 0; cnt < len; cnt++) {
231 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
233 static const char *prefix[] = {
243 if (len == 40 && !get_sha1_hex(str, sha1))
246 /* Accept only unambiguous ref paths. */
247 if (ambiguous_path(str, len))
250 for (p = prefix; *p; p++) {
251 char *pathname = git_path("%s/%.*s", *p, len, str);
253 if (!read_ref(pathname, sha1)) {
254 /* Must be unique; i.e. when heads/foo and
255 * tags/foo are both present, reject "foo".
261 /* We want to allow .git/description file and
262 * "description" branch to exist at the same time.
263 * "git-rev-parse description" should silently skip
264 * .git/description file as a candidate for
265 * get_sha1(). However, having garbage file anywhere
266 * under refs/ is not OK, and we would not have caught
267 * ambiguous heads and tags with the above test.
269 else if (**p && !access(pathname, F_OK)) {
270 /* Garbage exists under .git/refs */
271 return error("garbage ref found '%s'", pathname);
280 return error("ambiguous refname '%.*s'", len, str);
284 static int get_sha1_1(const char *name, int len, unsigned char *sha1);
286 static int get_parent(const char *name, int len,
287 unsigned char *result, int idx)
289 unsigned char sha1[20];
290 int ret = get_sha1_1(name, len, sha1);
291 struct commit *commit;
292 struct commit_list *p;
296 commit = lookup_commit_reference(sha1);
299 if (parse_commit(commit))
302 memcpy(result, commit->object.sha1, 20);
308 memcpy(result, p->item->object.sha1, 20);
316 static int get_nth_ancestor(const char *name, int len,
317 unsigned char *result, int generation)
319 unsigned char sha1[20];
320 int ret = get_sha1_1(name, len, sha1);
324 while (generation--) {
325 struct commit *commit = lookup_commit_reference(sha1);
327 if (!commit || parse_commit(commit) || !commit->parents)
329 memcpy(sha1, commit->parents->item->object.sha1, 20);
331 memcpy(result, sha1, 20);
335 static int peel_onion(const char *name, int len, unsigned char *sha1)
337 unsigned char outer[20];
339 const char *type_string = NULL;
343 * "ref^{type}" dereferences ref repeatedly until you cannot
344 * dereference anymore, or you get an object of given type,
345 * whichever comes first. "ref^{}" means just dereference
346 * tags until you get a non-tag. "ref^0" is a shorthand for
347 * "ref^{commit}". "commit^{tree}" could be used to find the
348 * top-level tree of the given commit.
350 if (len < 4 || name[len-1] != '}')
353 for (sp = name + len - 1; name <= sp; sp--) {
355 if (ch == '{' && name < sp && sp[-1] == '^')
361 sp++; /* beginning of type name, or closing brace for empty */
362 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
363 type_string = commit_type;
364 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
365 type_string = tree_type;
366 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
367 type_string = blob_type;
368 else if (sp[0] == '}')
373 if (get_sha1_1(name, sp - name - 2, outer))
376 o = parse_object(outer);
380 o = deref_tag(o, name, sp - name - 2);
381 if (!o || (!o->parsed && !parse_object(o->sha1)))
383 memcpy(sha1, o->sha1, 20);
386 /* At this point, the syntax look correct, so
387 * if we do not get the needed object, we should
392 if (!o || (!o->parsed && !parse_object(o->sha1)))
394 if (o->type == type_string) {
395 memcpy(sha1, o->sha1, 20);
398 if (o->type == tag_type)
399 o = ((struct tag*) o)->tagged;
400 else if (o->type == commit_type)
401 o = &(((struct commit *) o)->tree->object);
403 return error("%.*s: expected %s type, but the object dereferences to %s type",
404 len, name, type_string,
407 parse_object(o->sha1);
413 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
418 /* foo^[0-9] or foo^ (== foo^1); we do not do more than 9 parents. */
419 if (len > 2 && name[len-2] == '^' &&
420 name[len-1] >= '0' && name[len-1] <= '9') {
421 parent = name[len-1] - '0';
424 else if (len > 1 && name[len-1] == '^') {
431 return get_parent(name, len, sha1, parent);
433 /* "name~3" is "name^^^",
434 * "name~12" is "name^^^^^^^^^^^^", and
435 * "name~" and "name~0" are name -- not "name^0"!
438 for (cp = name + len - 1; name <= cp; cp--) {
440 if ('0' <= ch && ch <= '9')
446 if (!parent && *cp == '~') {
447 int len1 = cp - name;
449 while (cp < name + len)
450 parent = parent * 10 + *cp++ - '0';
451 return get_nth_ancestor(name, len1, sha1, parent);
454 ret = peel_onion(name, len, sha1);
458 ret = get_sha1_basic(name, len, sha1);
461 return get_short_sha1(name, len, sha1, 0);
465 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
466 * notably "xyz^" for "parent of xyz"
468 int get_sha1(const char *name, unsigned char *sha1)
471 return get_sha1_1(name, strlen(name), sha1);