sha1_name.c

   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"
   8
   9 static 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
  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;
  26
  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++;
  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 }
  55
  56 static 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
  71 static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
  72 {
  73         struct packed_git *p;
  74         const unsigned char *found_sha1 = NULL;
  75         int found = 0;
  76
  77         prepare_packed_git();
  78         for (p = packed_git; p && found < 2; p = p->next) {
  79                 uint32_t num = p->num_objects;
  80                 uint32_t first = 0, last = num;
  81                 while (first < last) {
  82                         uint32_t mid = (first + last) / 2;
  83                         const unsigned char *now;
  84                         int cmp;
  85
  86                         now = nth_packed_object_sha1(p, mid);
  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                         const unsigned char *now, *next;
 100                        now = nth_packed_object_sha1(p, first);
 101                         if (match_sha(len, match, now)) {
 102                                 next = nth_packed_object_sha1(p, first+1);
 103                                if (!next|| !match_sha(len, match, next)) {
 104                                         /* unique within this pack */
 105                                         if (!found) {
 106                                                 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
 127 #define SHORT_NAME_NOT_FOUND (-1)
 128 #define SHORT_NAME_AMBIGUOUS (-2)
 129
 130 static 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         prepare_alt_odb();
 137         has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
 138         has_packed = find_short_packed_object(len, res, packed_sha1);
 139         if (!has_unpacked && !has_packed)
 140                 return SHORT_NAME_NOT_FOUND;
 141         if (1 < has_unpacked || 1 < has_packed)
 142                 return SHORT_NAME_AMBIGUOUS;
 143         if (has_unpacked != has_packed) {
 144                 hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
 145                 return 0;
 146         }
 147         /* Both have unique ones -- do they match? */
 148         if (hashcmp(packed_sha1, unpacked_sha1))
 149                 return SHORT_NAME_AMBIGUOUS;
 150         hashcpy(sha1, packed_sha1);
 151         return 0;
 152 }
 153
 154 static int get_short_sha1(const char *name, int len, unsigned char *sha1,
 155                           int quietly)
 156 {
 157         int i, status;
 158         char canonical[40];
 159         unsigned char res[20];
 160
 161         if (len < MINIMUM_ABBREV || len > 40)
 162                 return -1;
 163         hashclr(res);
 164         memset(canonical, 'x', 40);
 165         for (i = 0; i < len ;i++) {
 166                 unsigned char c = name[i];
 167                 unsigned char val;
 168                 if (c >= '0' && c <= '9')
 169                         val = c - '0';
 170                 else if (c >= 'a' && c <= 'f')
 171                         val = c - 'a' + 10;
 172                 else if (c >= 'A' && c <='F') {
 173                         val = c - 'A' + 10;
 174                         c -= 'A' - 'a';
 175                 }
 176                 else
 177                         return -1;
 178                 canonical[i] = c;
 179                 if (!(i & 1))
 180                         val <<= 4;
 181                 res[i >> 1] |= val;
 182         }
 183
 184         status = find_unique_short_object(i, canonical, res, sha1);
 185         if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
 186                 return error("short SHA1 %.*s is ambiguous.", len, canonical);
 187         return status;
 188 }
 189
 190 const char *find_unique_abbrev(const unsigned char *sha1, int len)
 191 {
 192         int status, is_null;
 193         static char hex[41];
 194
 195         is_null = is_null_sha1(sha1);
 196         memcpy(hex, sha1_to_hex(sha1), 40);
 197         if (len == 40 || !len)
 198                 return hex;
 199         while (len < 40) {
 200                 unsigned char sha1_ret[20];
 201                 status = get_short_sha1(hex, len, sha1_ret, 1);
 202                 if (!status ||
 203                     (is_null && status != SHORT_NAME_AMBIGUOUS)) {
 204                         hex[len] = 0;
 205                         return hex;
 206                 }
 207                 if (status != SHORT_NAME_AMBIGUOUS)
 208                         return NULL;
 209                 len++;
 210         }
 211         return NULL;
 212 }
 213
 214 static int ambiguous_path(const char *path, int len)
 215 {
 216         int slash = 1;
 217         int cnt;
 218
 219         for (cnt = 0; cnt < len; cnt++) {
 220                 switch (*path++) {
 221                 case '\0':
 222                         break;
 223                 case '/':
 224                         if (slash)
 225                                 break;
 226                         slash = 1;
 227                         continue;
 228                 case '.':
 229                         continue;
 230                 default:
 231                         slash = 0;
 232                         continue;
 233                 }
 234                 break;
 235         }
 236         return slash;
 237 }
 238
 239 static const char *ref_fmt[] = {
 240         "%.*s",
 241         "refs/%.*s",
 242         "refs/tags/%.*s",
 243         "refs/heads/%.*s",
 244         "refs/remotes/%.*s",
 245         "refs/remotes/%.*s/HEAD",
 246         NULL
 247 };
 248
 249 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
 250 {
 251         const char **p, *r;
 252         int refs_found = 0;
 253
 254         *ref = NULL;
 255         for (p = ref_fmt; *p; p++) {
 256                 unsigned char sha1_from_ref[20];
 257                 unsigned char *this_result;
 258
 259                 this_result = refs_found ? sha1_from_ref : sha1;
 260                 r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
 261                 if (r) {
 262                         if (!refs_found++)
 263                                 *ref = xstrdup(r);
 264                         if (!warn_ambiguous_refs)
 265                                 break;
 266                 }
 267         }
 268         return refs_found;
 269 }
 270
 271 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
 272 {
 273         const char **p;
 274         int logs_found = 0;
 275
 276         *log = NULL;
 277         for (p = ref_fmt; *p; p++) {
 278                 struct stat st;
 279                 unsigned char hash[20];
 280                 char path[PATH_MAX];
 281                 const char *ref, *it;
 282
 283                 strcpy(path, mkpath(*p, len, str));
 284                 ref = resolve_ref(path, hash, 0, NULL);
 285                 if (!ref)
 286                         continue;
 287                 if (!stat(git_path("logs/%s", path), &st) &&
 288                     S_ISREG(st.st_mode))
 289                         it = path;
 290                 else if (strcmp(ref, path) &&
 291                          !stat(git_path("logs/%s", ref), &st) &&
 292                          S_ISREG(st.st_mode))
 293                         it = ref;
 294                 else
 295                         continue;
 296                 if (!logs_found++) {
 297                         *log = xstrdup(it);
 298                         hashcpy(sha1, hash);
 299                 }
 300                 if (!warn_ambiguous_refs)
 301                         break;
 302         }
 303         return logs_found;
 304 }
 305
 306 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 307 {
 308         static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
 309         char *real_ref = NULL;
 310         int refs_found = 0;
 311         int at, reflog_len;
 312
 313         if (len == 40 && !get_sha1_hex(str, sha1))
 314                 return 0;
 315
 316         /* basic@{time or number} format to query ref-log */
 317         reflog_len = at = 0;
 318         if (str[len-1] == '}') {
 319                 for (at = 0; at < len - 1; at++) {
 320                         if (str[at] == '@' && str[at+1] == '{') {
 321                                 reflog_len = (len-1) - (at+2);
 322                                 len = at;
 323                                 break;
 324                         }
 325                 }
 326         }
 327
 328         /* Accept only unambiguous ref paths. */
 329         if (len && ambiguous_path(str, len))
 330                 return -1;
 331
 332         if (!len && reflog_len) {
 333                 /* allow "@{...}" to mean the current branch reflog */
 334                 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
 335         } else if (reflog_len)
 336                 refs_found = dwim_log(str, len, sha1, &real_ref);
 337         else
 338                 refs_found = dwim_ref(str, len, sha1, &real_ref);
 339
 340         if (!refs_found)
 341                 return -1;
 342
 343         if (warn_ambiguous_refs && refs_found > 1)
 344                 fprintf(stderr, warning, len, str);
 345
 346         if (reflog_len) {
 347                 int nth, i;
 348                 unsigned long at_time;
 349                 unsigned long co_time;
 350                 int co_tz, co_cnt;
 351
 352                 /* Is it asking for N-th entry, or approxidate? */
 353                 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
 354                         char ch = str[at+2+i];
 355                         if ('0' <= ch && ch <= '9')
 356                                 nth = nth * 10 + ch - '0';
 357                         else
 358                                 nth = -1;
 359                 }
 360                 if (0 <= nth)
 361                         at_time = 0;
 362                 else
 363                         at_time = approxidate(str + at + 2);
 364                 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
 365                                 &co_time, &co_tz, &co_cnt)) {
 366                         if (at_time)
 367                                 fprintf(stderr,
 368                                         "warning: Log for '%.*s' only goes "
 369                                         "back to %s.\n", len, str,
 370                                         show_rfc2822_date(co_time, co_tz));
 371                         else
 372                                 fprintf(stderr,
 373                                         "warning: Log for '%.*s' only has "
 374                                         "%d entries.\n", len, str, co_cnt);
 375                 }
 376         }
 377
 378         free(real_ref);
 379         return 0;
 380 }
 381
 382 static int get_sha1_1(const char *name, int len, unsigned char *sha1);
 383
 384 static int get_parent(const char *name, int len,
 385                       unsigned char *result, int idx)
 386 {
 387         unsigned char sha1[20];
 388         int ret = get_sha1_1(name, len, sha1);
 389         struct commit *commit;
 390         struct commit_list *p;
 391
 392         if (ret)
 393                 return ret;
 394         commit = lookup_commit_reference(sha1);
 395         if (!commit)
 396                 return -1;
 397         if (parse_commit(commit))
 398                 return -1;
 399         if (!idx) {
 400                 hashcpy(result, commit->object.sha1);
 401                 return 0;
 402         }
 403         p = commit->parents;
 404         while (p) {
 405                 if (!--idx) {
 406                         hashcpy(result, p->item->object.sha1);
 407                         return 0;
 408                 }
 409                 p = p->next;
 410         }
 411         return -1;
 412 }
 413
 414 static int get_nth_ancestor(const char *name, int len,
 415                             unsigned char *result, int generation)
 416 {
 417         unsigned char sha1[20];
 418         int ret = get_sha1_1(name, len, sha1);
 419         if (ret)
 420                 return ret;
 421
 422         while (generation--) {
 423                 struct commit *commit = lookup_commit_reference(sha1);
 424
 425                 if (!commit || parse_commit(commit) || !commit->parents)
 426                         return -1;
 427                 hashcpy(sha1, commit->parents->item->object.sha1);
 428         }
 429         hashcpy(result, sha1);
 430         return 0;
 431 }
 432
 433 static int peel_onion(const char *name, int len, unsigned char *sha1)
 434 {
 435         unsigned char outer[20];
 436         const char *sp;
 437         unsigned int expected_type = 0;
 438         struct object *o;
 439
 440         /*
 441          * "ref^{type}" dereferences ref repeatedly until you cannot
 442          * dereference anymore, or you get an object of given type,
 443          * whichever comes first.  "ref^{}" means just dereference
 444          * tags until you get a non-tag.  "ref^0" is a shorthand for
 445          * "ref^{commit}".  "commit^{tree}" could be used to find the
 446          * top-level tree of the given commit.
 447          */
 448         if (len < 4 || name[len-1] != '}')
 449                 return -1;
 450
 451         for (sp = name + len - 1; name <= sp; sp--) {
 452                 int ch = *sp;
 453                 if (ch == '{' && name < sp && sp[-1] == '^')
 454                         break;
 455         }
 456         if (sp <= name)
 457                 return -1;
 458
 459         sp++; /* beginning of type name, or closing brace for empty */
 460         if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
 461                 expected_type = OBJ_COMMIT;
 462         else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
 463                 expected_type = OBJ_TREE;
 464         else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
 465                 expected_type = OBJ_BLOB;
 466         else if (sp[0] == '}')
 467                 expected_type = OBJ_NONE;
 468         else
 469                 return -1;
 470
 471         if (get_sha1_1(name, sp - name - 2, outer))
 472                 return -1;
 473
 474         o = parse_object(outer);
 475         if (!o)
 476                 return -1;
 477         if (!expected_type) {
 478                 o = deref_tag(o, name, sp - name - 2);
 479                 if (!o || (!o->parsed && !parse_object(o->sha1)))
 480                         return -1;
 481                 hashcpy(sha1, o->sha1);
 482         }
 483         else {
 484                 /* At this point, the syntax look correct, so
 485                  * if we do not get the needed object, we should
 486                  * barf.
 487                  */
 488
 489                 while (1) {
 490                         if (!o || (!o->parsed && !parse_object(o->sha1)))
 491                                 return -1;
 492                         if (o->type == expected_type) {
 493                                 hashcpy(sha1, o->sha1);
 494                                 return 0;
 495                         }
 496                         if (o->type == OBJ_TAG)
 497                                 o = ((struct tag*) o)->tagged;
 498                         else if (o->type == OBJ_COMMIT)
 499                                 o = &(((struct commit *) o)->tree->object);
 500                         else
 501                                 return error("%.*s: expected %s type, but the object dereferences to %s type",
 502                                              len, name, typename(expected_type),
 503                                              typename(o->type));
 504                         if (!o->parsed)
 505                                 parse_object(o->sha1);
 506                 }
 507         }
 508         return 0;
 509 }
 510
 511 static int get_describe_name(const char *name, int len, unsigned char *sha1)
 512 {
 513         const char *cp;
 514
 515         for (cp = name + len - 1; name + 2 <= cp; cp--) {
 516                 char ch = *cp;
 517                 if (hexval(ch) & ~0377) {
 518                         /* We must be looking at g in "SOMETHING-g"
 519                          * for it to be describe output.
 520                          */
 521                         if (ch == 'g' && cp[-1] == '-') {
 522                                 cp++;
 523                                 len -= cp - name;
 524                                 return get_short_sha1(cp, len, sha1, 1);
 525                         }
 526                 }
 527         }
 528         return -1;
 529 }
 530
 531 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
 532 {
 533         int ret, has_suffix;
 534         const char *cp;
 535
 536         /* "name~3" is "name^^^",
 537          * "name~" and "name~0" are name -- not "name^0"!
 538          * "name^" is not "name^0"; it is "name^1".
 539          */
 540         has_suffix = 0;
 541         for (cp = name + len - 1; name <= cp; cp--) {
 542                 int ch = *cp;
 543                 if ('0' <= ch && ch <= '9')
 544                         continue;
 545                 if (ch == '~' || ch == '^')
 546                         has_suffix = ch;
 547                 break;
 548         }
 549
 550         if (has_suffix) {
 551                 int num = 0;
 552                 int len1 = cp - name;
 553                 cp++;
 554                 while (cp < name + len)
 555                         num = num * 10 + *cp++ - '0';
 556                 if (has_suffix == '^') {
 557                         if (!num && len1 == len - 1)
 558                                 num = 1;
 559                         return get_parent(name, len1, sha1, num);
 560                 }
 561                 /* else if (has_suffix == '~') -- goes without saying */
 562                 return get_nth_ancestor(name, len1, sha1, num);
 563         }
 564
 565         ret = peel_onion(name, len, sha1);
 566         if (!ret)
 567                 return 0;
 568
 569         ret = get_sha1_basic(name, len, sha1);
 570         if (!ret)
 571                 return 0;
 572
 573         /* It could be describe output that is "SOMETHING-gXXXX" */
 574         ret = get_describe_name(name, len, sha1);
 575         if (!ret)
 576                 return 0;
 577
 578         return get_short_sha1(name, len, sha1, 0);
 579 }
 580
 581 static int handle_one_ref(const char *path,
 582                 const unsigned char *sha1, int flag, void *cb_data)
 583 {
 584         struct commit_list **list = cb_data;
 585         struct object *object = parse_object(sha1);
 586         if (!object)
 587                 return 0;
 588         if (object->type == OBJ_TAG)
 589                 object = deref_tag(object, path, strlen(path));
 590         if (object->type != OBJ_COMMIT)
 591                 return 0;
 592         insert_by_date((struct commit *)object, list);
 593         return 0;
 594 }
 595
 596 /*
 597  * This interprets names like ':/Initial revision of "git"' by searching
 598  * through history and returning the first commit whose message starts
 599  * with the given string.
 600  *
 601  * For future extension, ':/!' is reserved. If you want to match a message
 602  * beginning with a '!', you have to repeat the exclamation mark.
 603  */
 604
 605 #define ONELINE_SEEN (1u<<20)
 606 static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
 607 {
 608         struct commit_list *list = NULL, *backup = NULL, *l;
 609         int retval = -1;
 610
 611         if (prefix[0] == '!') {
 612                 if (prefix[1] != '!')
 613                         die ("Invalid search pattern: %s", prefix);
 614                 prefix++;
 615         }
 616         if (!save_commit_buffer)
 617                 return error("Could not expand oneline-name.");
 618         for_each_ref(handle_one_ref, &list);
 619         for (l = list; l; l = l->next)
 620                 commit_list_insert(l->item, &backup);
 621         while (list) {
 622                 char *p;
 623                 struct commit *commit;
 624
 625                 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
 626                 parse_object(commit->object.sha1);
 627                 if (!commit->buffer || !(p = strstr(commit->buffer, "\n\n")))
 628                         continue;
 629                 if (!prefixcmp(p + 2, prefix)) {
 630                         hashcpy(sha1, commit->object.sha1);
 631                         retval = 0;
 632                         break;
 633                 }
 634         }
 635         free_commit_list(list);
 636         for (l = backup; l; l = l->next)
 637                 clear_commit_marks(l->item, ONELINE_SEEN);
 638         return retval;
 639 }
 640
 641 /*
 642  * This is like "get_sha1_basic()", except it allows "sha1 expressions",
 643  * notably "xyz^" for "parent of xyz"
 644  */
 645 int get_sha1(const char *name, unsigned char *sha1)
 646 {
 647         unsigned unused;
 648         return get_sha1_with_mode(name, sha1, &unused);
 649 }
 650
 651 int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode)
 652 {
 653         int ret, bracket_depth;
 654         int namelen = strlen(name);
 655         const char *cp;
 656
 657         *mode = S_IFINVALID;
 658         ret = get_sha1_1(name, namelen, sha1);
 659         if (!ret)
 660                 return ret;
 661         /* sha1:path --> object name of path in ent sha1
 662          * :path -> object name of path in index
 663          * :[0-3]:path -> object name of path in index at stage
 664          */
 665         if (name[0] == ':') {
 666                 int stage = 0;
 667                 struct cache_entry *ce;
 668                 int pos;
 669                 if (namelen > 2 && name[1] == '/')
 670                         return get_sha1_oneline(name + 2, sha1);
 671                 if (namelen < 3 ||
 672                     name[2] != ':' ||
 673                     name[1] < '0' || '3' < name[1])
 674                         cp = name + 1;
 675                 else {
 676                         stage = name[1] - '0';
 677                         cp = name + 3;
 678                 }
 679                 namelen = namelen - (cp - name);
 680                 if (!active_cache)
 681                         read_cache();
 682                 if (active_nr < 0)
 683                         return -1;
 684                 pos = cache_name_pos(cp, namelen);
 685                 if (pos < 0)
 686                         pos = -pos - 1;
 687                 while (pos < active_nr) {
 688                         ce = active_cache[pos];
 689                         if (ce_namelen(ce) != namelen ||
 690                             memcmp(ce->name, cp, namelen))
 691                                 break;
 692                         if (ce_stage(ce) == stage) {
 693                                 hashcpy(sha1, ce->sha1);
 694                                 *mode = ntohl(ce->ce_mode);
 695                                 return 0;
 696                         }
 697                         pos++;
 698                 }
 699                 return -1;
 700         }
 701         for (cp = name, bracket_depth = 0; *cp; cp++) {
 702                 if (*cp == '{')
 703                         bracket_depth++;
 704                 else if (bracket_depth && *cp == '}')
 705                         bracket_depth--;
 706                 else if (!bracket_depth && *cp == ':')
 707                         break;
 708         }
 709         if (*cp == ':') {
 710                 unsigned char tree_sha1[20];
 711                 if (!get_sha1_1(name, cp-name, tree_sha1))
 712                         return get_tree_entry(tree_sha1, cp+1, sha1,
 713                                               mode);
 714         }
 715         return ret;
 716 }