format-patch: take sequence of ranges.
[git/dscho.git] / sha1_name.c
blob4e9a052333dcbb538866766f68b4fe18f615fe4d
1 #include "cache.h"
2 #include "commit.h"
4 static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
6 struct alternate_object_database *alt;
7 char hex[40];
8 int found = 0;
9 static struct alternate_object_database *fakeent;
11 if (!fakeent) {
12 const char *objdir = get_object_directory();
13 int objdir_len = strlen(objdir);
14 int entlen = objdir_len + 43;
15 fakeent = xmalloc(sizeof(*fakeent) + entlen);
16 memcpy(fakeent->base, objdir, objdir_len);
17 fakeent->name = fakeent->base + objdir_len + 1;
18 fakeent->name[-1] = '/';
20 fakeent->next = alt_odb_list;
22 sprintf(hex, "%.2s", name);
23 for (alt = fakeent; alt && found < 2; alt = alt->next) {
24 struct dirent *de;
25 DIR *dir;
26 sprintf(alt->name, "%.2s/", name);
27 dir = opendir(alt->base);
28 if (!dir)
29 continue;
30 while ((de = readdir(dir)) != NULL) {
31 if (strlen(de->d_name) != 38)
32 continue;
33 if (memcmp(de->d_name, name + 2, len - 2))
34 continue;
35 if (!found) {
36 memcpy(hex + 2, de->d_name, 38);
37 found++;
39 else if (memcmp(hex + 2, de->d_name, 38)) {
40 found = 2;
41 break;
44 closedir(dir);
46 if (found == 1)
47 return get_sha1_hex(hex, sha1) == 0;
48 return found;
51 static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
53 do {
54 if (*a != *b)
55 return 0;
56 a++;
57 b++;
58 len -= 2;
59 } while (len > 1);
60 if (len)
61 if ((*a ^ *b) & 0xf0)
62 return 0;
63 return 1;
66 static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
68 struct packed_git *p;
69 unsigned char found_sha1[20];
70 int found = 0;
72 prepare_packed_git();
73 for (p = packed_git; p && found < 2; p = p->next) {
74 unsigned num = num_packed_objects(p);
75 unsigned first = 0, last = num;
76 while (first < last) {
77 unsigned mid = (first + last) / 2;
78 unsigned char now[20];
79 int cmp;
81 nth_packed_object_sha1(p, mid, now);
82 cmp = memcmp(match, now, 20);
83 if (!cmp) {
84 first = mid;
85 break;
87 if (cmp > 0) {
88 first = mid+1;
89 continue;
91 last = mid;
93 if (first < num) {
94 unsigned char now[20], next[20];
95 nth_packed_object_sha1(p, first, now);
96 if (match_sha(len, match, now)) {
97 if (nth_packed_object_sha1(p, first+1, next) ||
98 !match_sha(len, match, next)) {
99 /* unique within this pack */
100 if (!found) {
101 memcpy(found_sha1, now, 20);
102 found++;
104 else if (memcmp(found_sha1, now, 20)) {
105 found = 2;
106 break;
109 else {
110 /* not even unique within this pack */
111 found = 2;
112 break;
117 if (found == 1)
118 memcpy(sha1, found_sha1, 20);
119 return found;
122 #define SHORT_NAME_NOT_FOUND (-1)
123 #define SHORT_NAME_AMBIGUOUS (-2)
125 static int find_unique_short_object(int len, char *canonical,
126 unsigned char *res, unsigned char *sha1)
128 int has_unpacked, has_packed;
129 unsigned char unpacked_sha1[20], packed_sha1[20];
131 has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
132 has_packed = find_short_packed_object(len, res, packed_sha1);
133 if (!has_unpacked && !has_packed)
134 return SHORT_NAME_NOT_FOUND;
135 if (1 < has_unpacked || 1 < has_packed)
136 return SHORT_NAME_AMBIGUOUS;
137 if (has_unpacked != has_packed) {
138 memcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1), 20);
139 return 0;
141 /* Both have unique ones -- do they match? */
142 if (memcmp(packed_sha1, unpacked_sha1, 20))
143 return -2;
144 memcpy(sha1, packed_sha1, 20);
145 return 0;
148 static int get_short_sha1(const char *name, int len, unsigned char *sha1,
149 int quietly)
151 int i, status;
152 char canonical[40];
153 unsigned char res[20];
155 if (len < 4)
156 return -1;
157 memset(res, 0, 20);
158 memset(canonical, 'x', 40);
159 for (i = 0; i < len ;i++) {
160 unsigned char c = name[i];
161 unsigned char val;
162 if (c >= '0' && c <= '9')
163 val = c - '0';
164 else if (c >= 'a' && c <= 'f')
165 val = c - 'a' + 10;
166 else if (c >= 'A' && c <='F') {
167 val = c - 'A' + 10;
168 c -= 'A' - 'a';
170 else
171 return -1;
172 canonical[i] = c;
173 if (!(i & 1))
174 val <<= 4;
175 res[i >> 1] |= val;
178 status = find_unique_short_object(i, canonical, res, sha1);
179 if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
180 return error("short SHA1 %.*s is ambiguous.", len, canonical);
181 return status;
184 const char *find_unique_abbrev(const unsigned char *sha1, int len)
186 int status;
187 static char hex[41];
188 memcpy(hex, sha1_to_hex(sha1), 40);
189 while (len < 40) {
190 unsigned char sha1_ret[20];
191 status = get_short_sha1(hex, len, sha1_ret, 1);
192 if (!status) {
193 hex[len] = 0;
194 return hex;
196 if (status != SHORT_NAME_AMBIGUOUS)
197 return NULL;
198 len++;
200 return NULL;
203 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
205 static const char *prefix[] = {
207 "refs",
208 "refs/tags",
209 "refs/heads",
210 NULL
212 const char **p;
214 if (len == 40 && !get_sha1_hex(str, sha1))
215 return 0;
217 for (p = prefix; *p; p++) {
218 char *pathname = git_path("%s/%.*s", *p, len, str);
219 if (!read_ref(pathname, sha1))
220 return 0;
223 return -1;
226 static int get_sha1_1(const char *name, int len, unsigned char *sha1);
228 static int get_parent(const char *name, int len,
229 unsigned char *result, int idx)
231 unsigned char sha1[20];
232 int ret = get_sha1_1(name, len, sha1);
233 struct commit *commit;
234 struct commit_list *p;
236 if (ret)
237 return ret;
238 commit = lookup_commit_reference(sha1);
239 if (!commit)
240 return -1;
241 if (parse_commit(commit))
242 return -1;
243 if (!idx) {
244 memcpy(result, commit->object.sha1, 20);
245 return 0;
247 p = commit->parents;
248 while (p) {
249 if (!--idx) {
250 memcpy(result, p->item->object.sha1, 20);
251 return 0;
253 p = p->next;
255 return -1;
258 static int get_nth_ancestor(const char *name, int len,
259 unsigned char *result, int generation)
261 unsigned char sha1[20];
262 int ret = get_sha1_1(name, len, sha1);
263 if (ret)
264 return ret;
266 while (generation--) {
267 struct commit *commit = lookup_commit_reference(sha1);
269 if (!commit || parse_commit(commit) || !commit->parents)
270 return -1;
271 memcpy(sha1, commit->parents->item->object.sha1, 20);
273 memcpy(result, sha1, 20);
274 return 0;
277 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
279 int parent, ret;
280 const char *cp;
282 /* foo^[0-9] or foo^ (== foo^1); we do not do more than 9 parents. */
283 if (len > 2 && name[len-2] == '^' &&
284 name[len-1] >= '0' && name[len-1] <= '9') {
285 parent = name[len-1] - '0';
286 len -= 2;
288 else if (len > 1 && name[len-1] == '^') {
289 parent = 1;
290 len--;
291 } else
292 parent = -1;
294 if (parent >= 0)
295 return get_parent(name, len, sha1, parent);
297 /* "name~3" is "name^^^",
298 * "name~12" is "name^^^^^^^^^^^^", and
299 * "name~" and "name~0" are name -- not "name^0"!
301 parent = 0;
302 for (cp = name + len - 1; name <= cp; cp--) {
303 int ch = *cp;
304 if ('0' <= ch && ch <= '9')
305 continue;
306 if (ch != '~')
307 parent = -1;
308 break;
310 if (!parent && *cp == '~') {
311 int len1 = cp - name;
312 cp++;
313 while (cp < name + len)
314 parent = parent * 10 + *cp++ - '0';
315 return get_nth_ancestor(name, len1, sha1, parent);
318 ret = get_sha1_basic(name, len, sha1);
319 if (!ret)
320 return 0;
321 return get_short_sha1(name, len, sha1, 0);
325 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
326 * notably "xyz^" for "parent of xyz"
328 int get_sha1(const char *name, unsigned char *sha1)
330 prepare_alt_odb();
331 return get_sha1_1(name, strlen(name), sha1);