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, 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;
  88
  89                         now = nth_packed_object_sha1(p, mid);
  90                         cmp = hashcmp(match, now);
  91                         if (!cmp) {
  92                                 first = mid;
  93                                 break;
  94                         }
  95                         if (cmp > 0) {
  96                                 first = mid+1;
  97                                 continue;
  98                         }
  99                         last = mid;
 100                 }
 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++;
 111                                         }
 112                                         else if (hashcmp(found_sha1, now)) {
 113                                                 found = 2;
 114                                                 break;
 115                                         }
 116                                 }
 117                                 else {
 118                                         /* not even unique within this pack */
 119                                         found = 2;
 120                                         break;
 121                                 }
 122                         }
 123                 }
 124         }
 125         if (found == 1)
 126                 hashcpy(sha1, found_sha1);
 127         return found;
 128 }
 129
 130 #define SHORT_NAME_NOT_FOUND (-1)
 131 #define SHORT_NAME_AMBIGUOUS (-2)
 132
 133 static int find_unique_short_object(int len, char *canonical,
 134                                     unsigned char *res, unsigned char *sha1)
 135 {
 136         int has_unpacked, has_packed;
 137         unsigned char unpacked_sha1[20], packed_sha1[20];
 138
 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;
 149         }
 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;
 155 }
 156
 157 static int get_short_sha1(const char *name, int len, unsigned char *sha1,
 158                           int quietly)
 159 {
 160         int i, status;
 161         char canonical[40];
 162         unsigned char res[20];
 163
 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';
 178                 }
 179                 else
 180                         return -1;
 181                 canonical[i] = c;
 182                 if (!(i & 1))
 183                         val <<= 4;
 184                 res[i >> 1] |= val;
 185         }
 186
 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;
 191 }
 192
 193 const char *find_unique_abbrev(const unsigned char *sha1, int len)
 194 {
 195         int status, is_null;
 196         static char hex[41];
 197
 198         is_null = is_null_sha1(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 (!status ||
 206                     (is_null && status != SHORT_NAME_AMBIGUOUS)) {
 207                         hex[len] = 0;
 208                         return hex;
 209                 }
 210                 if (status != SHORT_NAME_AMBIGUOUS)
 211                         return NULL;
 212                 len++;
 213         }
 214         return NULL;
 215 }
 216
 217 static int ambiguous_path(const char *path, int len)
 218 {
 219         int slash = 1;
 220         int cnt;
 221
 222         for (cnt = 0; cnt < len; cnt++) {
 223                 switch (*path++) {
 224                 case '\0':
 225                         break;
 226                 case '/':
 227                         if (slash)
 228                                 break;
 229                         slash = 1;
 230                         continue;
 231                 case '.':
 232                         continue;
 233                 default:
 234                         slash = 0;
 235                         continue;
 236                 }
 237                 break;
 238         }
 239         return slash;
 240 }
 241
 242 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
 243 {
 244         const char **p, *r;
 245         int refs_found = 0;
 246
 247         *ref = NULL;
 248         for (p = ref_rev_parse_rules; *p; p++) {
 249                 unsigned char sha1_from_ref[20];
 250                 unsigned char *this_result;
 251
 252                 this_result = refs_found ? sha1_from_ref : sha1;
 253                 r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
 254                 if (r) {
 255                         if (!refs_found++)
 256                                 *ref = xstrdup(r);
 257                         if (!warn_ambiguous_refs)
 258                                 break;
 259                 }
 260         }
 261         return refs_found;
 262 }
 263
 264 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
 265 {
 266         const char **p;
 267         int logs_found = 0;
 268
 269         *log = NULL;
 270         for (p = ref_rev_parse_rules; *p; p++) {
 271                 struct stat st;
 272                 unsigned char hash[20];
 273                 char path[PATH_MAX];
 274                 const char *ref, *it;
 275
 276                 strcpy(path, mkpath(*p, len, str));
 277                 ref = resolve_ref(path, hash, 0, NULL);
 278                 if (!ref)
 279                         continue;
 280                 if (!stat(git_path("logs/%s", path), &st) &&
 281                     S_ISREG(st.st_mode))
 282                         it = path;
 283                 else if (strcmp(ref, path) &&
 284                          !stat(git_path("logs/%s", ref), &st) &&
 285                          S_ISREG(st.st_mode))
 286                         it = ref;
 287                 else
 288                         continue;
 289                 if (!logs_found++) {
 290                         *log = xstrdup(it);
 291                         hashcpy(sha1, hash);
 292                 }
 293                 if (!warn_ambiguous_refs)
 294                         break;
 295         }
 296         return logs_found;
 297 }
 298
 299 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 300 {
 301         static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
 302         char *real_ref = NULL;
 303         int refs_found = 0;
 304         int at, reflog_len;
 305
 306         if (len == 40 && !get_sha1_hex(str, sha1))
 307                 return 0;
 308
 309         /* basic@{time or number} format to query ref-log */
 310         reflog_len = at = 0;
 311         if (str[len-1] == '}') {
 312                 for (at = 0; at < len - 1; at++) {
 313                         if (str[at] == '@' && str[at+1] == '{') {
 314                                 reflog_len = (len-1) - (at+2);
 315                                 len = at;
 316                                 break;
 317                         }
 318                 }
 319         }
 320
 321         /* Accept only unambiguous ref paths. */
 322         if (len && ambiguous_path(str, len))
 323                 return -1;
 324
 325         if (!len && reflog_len) {
 326                 /* allow "@{...}" to mean the current branch reflog */
 327                 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
 328         } else if (reflog_len)
 329                 refs_found = dwim_log(str, len, sha1, &real_ref);
 330         else
 331                 refs_found = dwim_ref(str, len, sha1, &real_ref);
 332
 333         if (!refs_found)
 334                 return -1;
 335
 336         if (warn_ambiguous_refs && refs_found > 1)
 337                 fprintf(stderr, warning, len, str);
 338
 339         if (reflog_len) {
 340                 int nth, i;
 341                 unsigned long at_time;
 342                 unsigned long co_time;
 343                 int co_tz, co_cnt;
 344
 345                 /* Is it asking for N-th entry, or approxidate? */
 346                 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
 347                         char ch = str[at+2+i];
 348                         if ('0' <= ch && ch <= '9')
 349                                 nth = nth * 10 + ch - '0';
 350                         else
 351                                 nth = -1;
 352                 }
 353                 if (0 <= nth)
 354                         at_time = 0;
 355                 else
 356                         at_time = approxidate(str + at + 2);
 357                 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
 358                                 &co_time, &co_tz, &co_cnt)) {
 359                         if (at_time)
 360                                 fprintf(stderr,
 361                                         "warning: Log for '%.*s' only goes "
 362                                         "back to %s.\n", len, str,
 363                                         show_date(co_time, co_tz, DATE_RFC2822));
 364                         else
 365                                 fprintf(stderr,
 366                                         "warning: Log for '%.*s' only has "
 367                                         "%d entries.\n", len, str, co_cnt);
 368                 }
 369         }
 370
 371         free(real_ref);
 372         return 0;
 373 }
 374
 375 static int get_sha1_1(const char *name, int len, unsigned char *sha1);
 376
 377 static int get_parent(const char *name, int len,
 378                       unsigned char *result, int idx)
 379 {
 380         unsigned char sha1[20];
 381         int ret = get_sha1_1(name, len, sha1);
 382         struct commit *commit;
 383         struct commit_list *p;
 384
 385         if (ret)
 386                 return ret;
 387         commit = lookup_commit_reference(sha1);
 388         if (!commit)
 389                 return -1;
 390         if (parse_commit(commit))
 391                 return -1;
 392         if (!idx) {
 393                 hashcpy(result, commit->object.sha1);
 394                 return 0;
 395         }
 396         p = commit->parents;
 397         while (p) {
 398                 if (!--idx) {
 399                         hashcpy(result, p->item->object.sha1);
 400                         return 0;
 401                 }
 402                 p = p->next;
 403         }
 404         return -1;
 405 }
 406
 407 static int get_nth_ancestor(const char *name, int len,
 408                             unsigned char *result, int generation)
 409 {
 410         unsigned char sha1[20];
 411         int ret = get_sha1_1(name, len, sha1);
 412         if (ret)
 413                 return ret;
 414
 415         while (generation--) {
 416                 struct commit *commit = lookup_commit_reference(sha1);
 417
 418                 if (!commit || parse_commit(commit) || !commit->parents)
 419                         return -1;
 420                 hashcpy(sha1, commit->parents->item->object.sha1);
 421         }
 422         hashcpy(result, sha1);
 423         return 0;
 424 }
 425
 426 static int peel_onion(const char *name, int len, unsigned char *sha1)
 427 {
 428         unsigned char outer[20];
 429         const char *sp;
 430         unsigned int expected_type = 0;
 431         struct object *o;
 432
 433         /*
 434          * "ref^{type}" dereferences ref repeatedly until you cannot
 435          * dereference anymore, or you get an object of given type,
 436          * whichever comes first.  "ref^{}" means just dereference
 437          * tags until you get a non-tag.  "ref^0" is a shorthand for
 438          * "ref^{commit}".  "commit^{tree}" could be used to find the
 439          * top-level tree of the given commit.
 440          */
 441         if (len < 4 || name[len-1] != '}')
 442                 return -1;
 443
 444         for (sp = name + len - 1; name <= sp; sp--) {
 445                 int ch = *sp;
 446                 if (ch == '{' && name < sp && sp[-1] == '^')
 447                         break;
 448         }
 449         if (sp <= name)
 450                 return -1;
 451
 452         sp++; /* beginning of type name, or closing brace for empty */
 453         if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
 454                 expected_type = OBJ_COMMIT;
 455         else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
 456                 expected_type = OBJ_TREE;
 457         else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
 458                 expected_type = OBJ_BLOB;
 459         else if (sp[0] == '}')
 460                 expected_type = OBJ_NONE;
 461         else
 462                 return -1;
 463
 464         if (get_sha1_1(name, sp - name - 2, outer))
 465                 return -1;
 466
 467         o = parse_object(outer);
 468         if (!o)
 469                 return -1;
 470         if (!expected_type) {
 471                 o = deref_tag(o, name, sp - name - 2);
 472                 if (!o || (!o->parsed && !parse_object(o->sha1)))
 473                         return -1;
 474                 hashcpy(sha1, o->sha1);
 475         }
 476         else {
 477                 /* At this point, the syntax look correct, so
 478                  * if we do not get the needed object, we should
 479                  * barf.
 480                  */
 481
 482                 while (1) {
 483                         if (!o || (!o->parsed && !parse_object(o->sha1)))
 484                                 return -1;
 485                         if (o->type == expected_type) {
 486                                 hashcpy(sha1, o->sha1);
 487                                 return 0;
 488                         }
 489                         if (o->type == OBJ_TAG)
 490                                 o = ((struct tag*) o)->tagged;
 491                         else if (o->type == OBJ_COMMIT)
 492                                 o = &(((struct commit *) o)->tree->object);
 493                         else
 494                                 return error("%.*s: expected %s type, but the object dereferences to %s type",
 495                                              len, name, typename(expected_type),
 496                                              typename(o->type));
 497                         if (!o->parsed)
 498                                 parse_object(o->sha1);
 499                 }
 500         }
 501         return 0;
 502 }
 503
 504 static int get_describe_name(const char *name, int len, unsigned char *sha1)
 505 {
 506         const char *cp;
 507
 508         for (cp = name + len - 1; name + 2 <= cp; cp--) {
 509                 char ch = *cp;
 510                 if (hexval(ch) & ~0377) {
 511                         /* We must be looking at g in "SOMETHING-g"
 512                          * for it to be describe output.
 513                          */
 514                         if (ch == 'g' && cp[-1] == '-') {
 515                                 cp++;
 516                                 len -= cp - name;
 517                                 return get_short_sha1(cp, len, sha1, 1);
 518                         }
 519                 }
 520         }
 521         return -1;
 522 }
 523
 524 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
 525 {
 526         int ret, has_suffix;
 527         const char *cp;
 528
 529         /* "name~3" is "name^^^",
 530          * "name~" and "name~0" are name -- not "name^0"!
 531          * "name^" is not "name^0"; it is "name^1".
 532          */
 533         has_suffix = 0;
 534         for (cp = name + len - 1; name <= cp; cp--) {
 535                 int ch = *cp;
 536                 if ('0' <= ch && ch <= '9')
 537                         continue;
 538                 if (ch == '~' || ch == '^')
 539                         has_suffix = ch;
 540                 break;
 541         }
 542
 543         if (has_suffix) {
 544                 int num = 0;
 545                 int len1 = cp - name;
 546                 cp++;
 547                 while (cp < name + len)
 548                         num = num * 10 + *cp++ - '0';
 549                 if (has_suffix == '^') {
 550                         if (!num && len1 == len - 1)
 551                                 num = 1;
 552                         return get_parent(name, len1, sha1, num);
 553                 }
 554                 /* else if (has_suffix == '~') -- goes without saying */
 555                 return get_nth_ancestor(name, len1, sha1, num);
 556         }
 557
 558         ret = peel_onion(name, len, sha1);
 559         if (!ret)
 560                 return 0;
 561
 562         ret = get_sha1_basic(name, len, sha1);
 563         if (!ret)
 564                 return 0;
 565
 566         /* It could be describe output that is "SOMETHING-gXXXX" */
 567         ret = get_describe_name(name, len, sha1);
 568         if (!ret)
 569                 return 0;
 570
 571         return get_short_sha1(name, len, sha1, 0);
 572 }
 573
 574 static int handle_one_ref(const char *path,
 575                 const unsigned char *sha1, int flag, void *cb_data)
 576 {
 577         struct commit_list **list = cb_data;
 578         struct object *object = parse_object(sha1);
 579         if (!object)
 580                 return 0;
 581         if (object->type == OBJ_TAG)
 582                 object = deref_tag(object, path, strlen(path));
 583         if (object->type != OBJ_COMMIT)
 584                 return 0;
 585         insert_by_date((struct commit *)object, list);
 586         return 0;
 587 }
 588
 589 /*
 590  * This interprets names like ':/Initial revision of "git"' by searching
 591  * through history and returning the first commit whose message starts
 592  * with the given string.
 593  *
 594  * For future extension, ':/!' is reserved. If you want to match a message
 595  * beginning with a '!', you have to repeat the exclamation mark.
 596  */
 597
 598 #define ONELINE_SEEN (1u<<20)
 599 static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
 600 {
 601         struct commit_list *list = NULL, *backup = NULL, *l;
 602         int retval = -1;
 603
 604         if (prefix[0] == '!') {
 605                 if (prefix[1] != '!')
 606                         die ("Invalid search pattern: %s", prefix);
 607                 prefix++;
 608         }
 609         if (!save_commit_buffer)
 610                 return error("Could not expand oneline-name.");
 611         for_each_ref(handle_one_ref, &list);
 612         for (l = list; l; l = l->next)
 613                 commit_list_insert(l->item, &backup);
 614         while (list) {
 615                 char *p;
 616                 struct commit *commit;
 617
 618                 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
 619                 parse_object(commit->object.sha1);
 620                 if (!commit->buffer || !(p = strstr(commit->buffer, "\n\n")))
 621                         continue;
 622                 if (!prefixcmp(p + 2, prefix)) {
 623                         hashcpy(sha1, commit->object.sha1);
 624                         retval = 0;
 625                         break;
 626                 }
 627         }
 628         free_commit_list(list);
 629         for (l = backup; l; l = l->next)
 630                 clear_commit_marks(l->item, ONELINE_SEEN);
 631         return retval;
 632 }
 633
 634 /*
 635  * This is like "get_sha1_basic()", except it allows "sha1 expressions",
 636  * notably "xyz^" for "parent of xyz"
 637  */
 638 int get_sha1(const char *name, unsigned char *sha1)
 639 {
 640         unsigned unused;
 641         return get_sha1_with_mode(name, sha1, &unused);
 642 }
 643
 644 int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode)
 645 {
 646         int ret, bracket_depth;
 647         int namelen = strlen(name);
 648         const char *cp;
 649
 650         *mode = S_IFINVALID;
 651         ret = get_sha1_1(name, namelen, sha1);
 652         if (!ret)
 653                 return ret;
 654         /* sha1:path --> object name of path in ent sha1
 655          * :path -> object name of path in index
 656          * :[0-3]:path -> object name of path in index at stage
 657          */
 658         if (name[0] == ':') {
 659                 int stage = 0;
 660                 struct cache_entry *ce;
 661                 int pos;
 662                 if (namelen > 2 && name[1] == '/')
 663                         return get_sha1_oneline(name + 2, sha1);
 664                 if (namelen < 3 ||
 665                     name[2] != ':' ||
 666                     name[1] < '0' || '3' < name[1])
 667                         cp = name + 1;
 668                 else {
 669                         stage = name[1] - '0';
 670                         cp = name + 3;
 671                 }
 672                 namelen = namelen - (cp - name);
 673                 if (!active_cache)
 674                         read_cache();
 675                 pos = cache_name_pos(cp, namelen);
 676                 if (pos < 0)
 677                         pos = -pos - 1;
 678                 while (pos < active_nr) {
 679                         ce = active_cache[pos];
 680                         if (ce_namelen(ce) != namelen ||
 681                             memcmp(ce->name, cp, namelen))
 682                                 break;
 683                         if (ce_stage(ce) == stage) {
 684                                 hashcpy(sha1, ce->sha1);
 685                                 *mode = ntohl(ce->ce_mode);
 686                                 return 0;
 687                         }
 688                         pos++;
 689                 }
 690                 return -1;
 691         }
 692         for (cp = name, bracket_depth = 0; *cp; cp++) {
 693                 if (*cp == '{')
 694                         bracket_depth++;
 695                 else if (bracket_depth && *cp == '}')
 696                         bracket_depth--;
 697                 else if (!bracket_depth && *cp == ':')
 698                         break;
 699         }
 700         if (*cp == ':') {
 701                 unsigned char tree_sha1[20];
 702                 if (!get_sha1_1(name, cp-name, tree_sha1))
 703                         return get_tree_entry(tree_sha1, cp+1, sha1,
 704                                               mode);
 705         }
 706         return ret;
 707 }