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 static const char *ref_fmt[] = {
 243         "%.*s",
 244         "refs/%.*s",
 245         "refs/tags/%.*s",
 246         "refs/heads/%.*s",
 247         "refs/remotes/%.*s",
 248         "refs/remotes/%.*s/HEAD",
 249         NULL
 250 };
 251
 252 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
 253 {
 254         const char **p, *r;
 255         int refs_found = 0;
 256
 257         *ref = NULL;
 258         for (p = ref_fmt; *p; p++) {
 259                 unsigned char sha1_from_ref[20];
 260                 unsigned char *this_result;
 261
 262                 this_result = refs_found ? sha1_from_ref : sha1;
 263                 r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
 264                 if (r) {
 265                         if (!refs_found++)
 266                                 *ref = xstrdup(r);
 267                         if (!warn_ambiguous_refs)
 268                                 break;
 269                 }
 270         }
 271         return refs_found;
 272 }
 273
 274 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
 275 {
 276         const char **p;
 277         int logs_found = 0;
 278
 279         *log = NULL;
 280         for (p = ref_fmt; *p; p++) {
 281                 struct stat st;
 282                 unsigned char hash[20];
 283                 char path[PATH_MAX];
 284                 const char *ref, *it;
 285
 286                 strcpy(path, mkpath(*p, len, str));
 287                 ref = resolve_ref(path, hash, 0, NULL);
 288                 if (!ref)
 289                         continue;
 290                 if (!stat(git_path("logs/%s", path), &st) &&
 291                     S_ISREG(st.st_mode))
 292                         it = path;
 293                 else if (strcmp(ref, path) &&
 294                          !stat(git_path("logs/%s", ref), &st) &&
 295                          S_ISREG(st.st_mode))
 296                         it = ref;
 297                 else
 298                         continue;
 299                 if (!logs_found++) {
 300                         *log = xstrdup(it);
 301                         hashcpy(sha1, hash);
 302                 }
 303                 if (!warn_ambiguous_refs)
 304                         break;
 305         }
 306         return logs_found;
 307 }
 308
 309 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 310 {
 311         static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
 312         char *real_ref = NULL;
 313         int refs_found = 0;
 314         int at, reflog_len;
 315
 316         if (len == 40 && !get_sha1_hex(str, sha1))
 317                 return 0;
 318
 319         /* basic@{time or number} format to query ref-log */
 320         reflog_len = at = 0;
 321         if (str[len-1] == '}') {
 322                 for (at = 0; at < len - 1; at++) {
 323                         if (str[at] == '@' && str[at+1] == '{') {
 324                                 reflog_len = (len-1) - (at+2);
 325                                 len = at;
 326                                 break;
 327                         }
 328                 }
 329         }
 330
 331         /* Accept only unambiguous ref paths. */
 332         if (len && ambiguous_path(str, len))
 333                 return -1;
 334
 335         if (!len && reflog_len) {
 336                 /* allow "@{...}" to mean the current branch reflog */
 337                 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
 338         } else if (reflog_len)
 339                 refs_found = dwim_log(str, len, sha1, &real_ref);
 340         else
 341                 refs_found = dwim_ref(str, len, sha1, &real_ref);
 342
 343         if (!refs_found)
 344                 return -1;
 345
 346         if (warn_ambiguous_refs && refs_found > 1)
 347                 fprintf(stderr, warning, len, str);
 348
 349         if (reflog_len) {
 350                 int nth, i;
 351                 unsigned long at_time;
 352                 unsigned long co_time;
 353                 int co_tz, co_cnt;
 354
 355                 /* Is it asking for N-th entry, or approxidate? */
 356                 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
 357                         char ch = str[at+2+i];
 358                         if ('0' <= ch && ch <= '9')
 359                                 nth = nth * 10 + ch - '0';
 360                         else
 361                                 nth = -1;
 362                 }
 363                 if (0 <= nth)
 364                         at_time = 0;
 365                 else
 366                         at_time = approxidate(str + at + 2);
 367                 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
 368                                 &co_time, &co_tz, &co_cnt)) {
 369                         if (at_time)
 370                                 fprintf(stderr,
 371                                         "warning: Log for '%.*s' only goes "
 372                                         "back to %s.\n", len, str,
 373                                         show_rfc2822_date(co_time, co_tz));
 374                         else
 375                                 fprintf(stderr,
 376                                         "warning: Log for '%.*s' only has "
 377                                         "%d entries.\n", len, str, co_cnt);
 378                 }
 379         }
 380
 381         free(real_ref);
 382         return 0;
 383 }
 384
 385 static int get_sha1_1(const char *name, int len, unsigned char *sha1);
 386
 387 static int get_parent(const char *name, int len,
 388                       unsigned char *result, int idx)
 389 {
 390         unsigned char sha1[20];
 391         int ret = get_sha1_1(name, len, sha1);
 392         struct commit *commit;
 393         struct commit_list *p;
 394
 395         if (ret)
 396                 return ret;
 397         commit = lookup_commit_reference(sha1);
 398         if (!commit)
 399                 return -1;
 400         if (parse_commit(commit))
 401                 return -1;
 402         if (!idx) {
 403                 hashcpy(result, commit->object.sha1);
 404                 return 0;
 405         }
 406         p = commit->parents;
 407         while (p) {
 408                 if (!--idx) {
 409                         hashcpy(result, p->item->object.sha1);
 410                         return 0;
 411                 }
 412                 p = p->next;
 413         }
 414         return -1;
 415 }
 416
 417 static int get_nth_ancestor(const char *name, int len,
 418                             unsigned char *result, int generation)
 419 {
 420         unsigned char sha1[20];
 421         int ret = get_sha1_1(name, len, sha1);
 422         if (ret)
 423                 return ret;
 424
 425         while (generation--) {
 426                 struct commit *commit = lookup_commit_reference(sha1);
 427
 428                 if (!commit || parse_commit(commit) || !commit->parents)
 429                         return -1;
 430                 hashcpy(sha1, commit->parents->item->object.sha1);
 431         }
 432         hashcpy(result, sha1);
 433         return 0;
 434 }
 435
 436 static int peel_onion(const char *name, int len, unsigned char *sha1)
 437 {
 438         unsigned char outer[20];
 439         const char *sp;
 440         unsigned int expected_type = 0;
 441         struct object *o;
 442
 443         /*
 444          * "ref^{type}" dereferences ref repeatedly until you cannot
 445          * dereference anymore, or you get an object of given type,
 446          * whichever comes first.  "ref^{}" means just dereference
 447          * tags until you get a non-tag.  "ref^0" is a shorthand for
 448          * "ref^{commit}".  "commit^{tree}" could be used to find the
 449          * top-level tree of the given commit.
 450          */
 451         if (len < 4 || name[len-1] != '}')
 452                 return -1;
 453
 454         for (sp = name + len - 1; name <= sp; sp--) {
 455                 int ch = *sp;
 456                 if (ch == '{' && name < sp && sp[-1] == '^')
 457                         break;
 458         }
 459         if (sp <= name)
 460                 return -1;
 461
 462         sp++; /* beginning of type name, or closing brace for empty */
 463         if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
 464                 expected_type = OBJ_COMMIT;
 465         else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
 466                 expected_type = OBJ_TREE;
 467         else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
 468                 expected_type = OBJ_BLOB;
 469         else if (sp[0] == '}')
 470                 expected_type = OBJ_NONE;
 471         else
 472                 return -1;
 473
 474         if (get_sha1_1(name, sp - name - 2, outer))
 475                 return -1;
 476
 477         o = parse_object(outer);
 478         if (!o)
 479                 return -1;
 480         if (!expected_type) {
 481                 o = deref_tag(o, name, sp - name - 2);
 482                 if (!o || (!o->parsed && !parse_object(o->sha1)))
 483                         return -1;
 484                 hashcpy(sha1, o->sha1);
 485         }
 486         else {
 487                 /* At this point, the syntax look correct, so
 488                  * if we do not get the needed object, we should
 489                  * barf.
 490                  */
 491
 492                 while (1) {
 493                         if (!o || (!o->parsed && !parse_object(o->sha1)))
 494                                 return -1;
 495                         if (o->type == expected_type) {
 496                                 hashcpy(sha1, o->sha1);
 497                                 return 0;
 498                         }
 499                         if (o->type == OBJ_TAG)
 500                                 o = ((struct tag*) o)->tagged;
 501                         else if (o->type == OBJ_COMMIT)
 502                                 o = &(((struct commit *) o)->tree->object);
 503                         else
 504                                 return error("%.*s: expected %s type, but the object dereferences to %s type",
 505                                              len, name, typename(expected_type),
 506                                              typename(o->type));
 507                         if (!o->parsed)
 508                                 parse_object(o->sha1);
 509                 }
 510         }
 511         return 0;
 512 }
 513
 514 static int get_describe_name(const char *name, int len, unsigned char *sha1)
 515 {
 516         const char *cp;
 517
 518         for (cp = name + len - 1; name + 2 <= cp; cp--) {
 519                 char ch = *cp;
 520                 if (hexval(ch) & ~0377) {
 521                         /* We must be looking at g in "SOMETHING-g"
 522                          * for it to be describe output.
 523                          */
 524                         if (ch == 'g' && cp[-1] == '-') {
 525                                 cp++;
 526                                 len -= cp - name;
 527                                 return get_short_sha1(cp, len, sha1, 1);
 528                         }
 529                 }
 530         }
 531         return -1;
 532 }
 533
 534 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
 535 {
 536         int ret, has_suffix;
 537         const char *cp;
 538
 539         /* "name~3" is "name^^^",
 540          * "name~" and "name~0" are name -- not "name^0"!
 541          * "name^" is not "name^0"; it is "name^1".
 542          */
 543         has_suffix = 0;
 544         for (cp = name + len - 1; name <= cp; cp--) {
 545                 int ch = *cp;
 546                 if ('0' <= ch && ch <= '9')
 547                         continue;
 548                 if (ch == '~' || ch == '^')
 549                         has_suffix = ch;
 550                 break;
 551         }
 552
 553         if (has_suffix) {
 554                 int num = 0;
 555                 int len1 = cp - name;
 556                 cp++;
 557                 while (cp < name + len)
 558                         num = num * 10 + *cp++ - '0';
 559                 if (has_suffix == '^') {
 560                         if (!num && len1 == len - 1)
 561                                 num = 1;
 562                         return get_parent(name, len1, sha1, num);
 563                 }
 564                 /* else if (has_suffix == '~') -- goes without saying */
 565                 return get_nth_ancestor(name, len1, sha1, num);
 566         }
 567
 568         ret = peel_onion(name, len, sha1);
 569         if (!ret)
 570                 return 0;
 571
 572         ret = get_sha1_basic(name, len, sha1);
 573         if (!ret)
 574                 return 0;
 575
 576         /* It could be describe output that is "SOMETHING-gXXXX" */
 577         ret = get_describe_name(name, len, sha1);
 578         if (!ret)
 579                 return 0;
 580
 581         return get_short_sha1(name, len, sha1, 0);
 582 }
 583
 584 static int handle_one_ref(const char *path,
 585                 const unsigned char *sha1, int flag, void *cb_data)
 586 {
 587         struct commit_list **list = cb_data;
 588         struct object *object = parse_object(sha1);
 589         if (!object)
 590                 return 0;
 591         if (object->type == OBJ_TAG)
 592                 object = deref_tag(object, path, strlen(path));
 593         if (object->type != OBJ_COMMIT)
 594                 return 0;
 595         insert_by_date((struct commit *)object, list);
 596         return 0;
 597 }
 598
 599 /*
 600  * This interprets names like ':/Initial revision of "git"' by searching
 601  * through history and returning the first commit whose message starts
 602  * with the given string.
 603  *
 604  * For future extension, ':/!' is reserved. If you want to match a message
 605  * beginning with a '!', you have to repeat the exclamation mark.
 606  */
 607
 608 #define ONELINE_SEEN (1u<<20)
 609 static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
 610 {
 611         struct commit_list *list = NULL, *backup = NULL, *l;
 612         int retval = -1;
 613
 614         if (prefix[0] == '!') {
 615                 if (prefix[1] != '!')
 616                         die ("Invalid search pattern: %s", prefix);
 617                 prefix++;
 618         }
 619         if (!save_commit_buffer)
 620                 return error("Could not expand oneline-name.");
 621         for_each_ref(handle_one_ref, &list);
 622         for (l = list; l; l = l->next)
 623                 commit_list_insert(l->item, &backup);
 624         while (list) {
 625                 char *p;
 626                 struct commit *commit;
 627
 628                 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
 629                 parse_object(commit->object.sha1);
 630                 if (!commit->buffer || !(p = strstr(commit->buffer, "\n\n")))
 631                         continue;
 632                 if (!prefixcmp(p + 2, prefix)) {
 633                         hashcpy(sha1, commit->object.sha1);
 634                         retval = 0;
 635                         break;
 636                 }
 637         }
 638         free_commit_list(list);
 639         for (l = backup; l; l = l->next)
 640                 clear_commit_marks(l->item, ONELINE_SEEN);
 641         return retval;
 642 }
 643
 644 /*
 645  * This is like "get_sha1_basic()", except it allows "sha1 expressions",
 646  * notably "xyz^" for "parent of xyz"
 647  */
 648 int get_sha1(const char *name, unsigned char *sha1)
 649 {
 650         unsigned unused;
 651         return get_sha1_with_mode(name, sha1, &unused);
 652 }
 653
 654 int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode)
 655 {
 656         int ret, bracket_depth;
 657         int namelen = strlen(name);
 658         const char *cp;
 659
 660         *mode = S_IFINVALID;
 661         ret = get_sha1_1(name, namelen, sha1);
 662         if (!ret)
 663                 return ret;
 664         /* sha1:path --> object name of path in ent sha1
 665          * :path -> object name of path in index
 666          * :[0-3]:path -> object name of path in index at stage
 667          */
 668         if (name[0] == ':') {
 669                 int stage = 0;
 670                 struct cache_entry *ce;
 671                 int pos;
 672                 if (namelen > 2 && name[1] == '/')
 673                         return get_sha1_oneline(name + 2, sha1);
 674                 if (namelen < 3 ||
 675                     name[2] != ':' ||
 676                     name[1] < '0' || '3' < name[1])
 677                         cp = name + 1;
 678                 else {
 679                         stage = name[1] - '0';
 680                         cp = name + 3;
 681                 }
 682                 namelen = namelen - (cp - name);
 683                 if (!active_cache)
 684                         read_cache();
 685                 if (active_nr < 0)
 686                         return -1;
 687                 pos = cache_name_pos(cp, namelen);
 688                 if (pos < 0)
 689                         pos = -pos - 1;
 690                 while (pos < active_nr) {
 691                         ce = active_cache[pos];
 692                         if (ce_namelen(ce) != namelen ||
 693                             memcmp(ce->name, cp, namelen))
 694                                 break;
 695                         if (ce_stage(ce) == stage) {
 696                                 hashcpy(sha1, ce->sha1);
 697                                 *mode = ntohl(ce->ce_mode);
 698                                 return 0;
 699                         }
 700                         pos++;
 701                 }
 702                 return -1;
 703         }
 704         for (cp = name, bracket_depth = 0; *cp; cp++) {
 705                 if (*cp == '{')
 706                         bracket_depth++;
 707                 else if (bracket_depth && *cp == '}')
 708                         bracket_depth--;
 709                 else if (!bracket_depth && *cp == ':')
 710                         break;
 711         }
 712         if (*cp == ':') {
 713                 unsigned char tree_sha1[20];
 714                 if (!get_sha1_1(name, cp-name, tree_sha1))
 715                         return get_tree_entry(tree_sha1, cp+1, sha1,
 716                                               mode);
 717         }
 718         return ret;
 719 }