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, exists;
 196         static char hex[41];
 197
 198         exists = has_sha1_file(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 (exists
 206                     ? !status
 207                     : status == SHORT_NAME_NOT_FOUND) {
 208                         hex[len] = 0;
 209                         return hex;
 210                 }
 211                 len++;
 212         }
 213         return hex;
 214 }
 215
 216 static int ambiguous_path(const char *path, int len)
 217 {
 218         int slash = 1;
 219         int cnt;
 220
 221         for (cnt = 0; cnt < len; cnt++) {
 222                 switch (*path++) {
 223                 case '\0':
 224                         break;
 225                 case '/':
 226                         if (slash)
 227                                 break;
 228                         slash = 1;
 229                         continue;
 230                 case '.':
 231                         continue;
 232                 default:
 233                         slash = 0;
 234                         continue;
 235                 }
 236                 break;
 237         }
 238         return slash;
 239 }
 240
 241 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
 242 {
 243         const char **p, *r;
 244         int refs_found = 0;
 245
 246         *ref = NULL;
 247         for (p = ref_rev_parse_rules; *p; p++) {
 248                 unsigned char sha1_from_ref[20];
 249                 unsigned char *this_result;
 250
 251                 this_result = refs_found ? sha1_from_ref : sha1;
 252                 r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
 253                 if (r) {
 254                         if (!refs_found++)
 255                                 *ref = xstrdup(r);
 256                         if (!warn_ambiguous_refs)
 257                                 break;
 258                 }
 259         }
 260         return refs_found;
 261 }
 262
 263 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
 264 {
 265         const char **p;
 266         int logs_found = 0;
 267
 268         *log = NULL;
 269         for (p = ref_rev_parse_rules; *p; p++) {
 270                 struct stat st;
 271                 unsigned char hash[20];
 272                 char path[PATH_MAX];
 273                 const char *ref, *it;
 274
 275                 strcpy(path, mkpath(*p, len, str));
 276                 ref = resolve_ref(path, hash, 0, NULL);
 277                 if (!ref)
 278                         continue;
 279                 if (!stat(git_path("logs/%s", path), &st) &&
 280                     S_ISREG(st.st_mode))
 281                         it = path;
 282                 else if (strcmp(ref, path) &&
 283                          !stat(git_path("logs/%s", ref), &st) &&
 284                          S_ISREG(st.st_mode))
 285                         it = ref;
 286                 else
 287                         continue;
 288                 if (!logs_found++) {
 289                         *log = xstrdup(it);
 290                         hashcpy(sha1, hash);
 291                 }
 292                 if (!warn_ambiguous_refs)
 293                         break;
 294         }
 295         return logs_found;
 296 }
 297
 298 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 299 {
 300         static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
 301         char *real_ref = NULL;
 302         int refs_found = 0;
 303         int at, reflog_len;
 304
 305         if (len == 40 && !get_sha1_hex(str, sha1))
 306                 return 0;
 307
 308         /* basic@{time or number} format to query ref-log */
 309         reflog_len = at = 0;
 310         if (str[len-1] == '}') {
 311                 for (at = 0; at < len - 1; at++) {
 312                         if (str[at] == '@' && str[at+1] == '{') {
 313                                 reflog_len = (len-1) - (at+2);
 314                                 len = at;
 315                                 break;
 316                         }
 317                 }
 318         }
 319
 320         /* Accept only unambiguous ref paths. */
 321         if (len && ambiguous_path(str, len))
 322                 return -1;
 323
 324         if (!len && reflog_len) {
 325                 /* allow "@{...}" to mean the current branch reflog */
 326                 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
 327         } else if (reflog_len)
 328                 refs_found = dwim_log(str, len, sha1, &real_ref);
 329         else
 330                 refs_found = dwim_ref(str, len, sha1, &real_ref);
 331
 332         if (!refs_found)
 333                 return -1;
 334
 335         if (warn_ambiguous_refs && refs_found > 1)
 336                 fprintf(stderr, warning, len, str);
 337
 338         if (reflog_len) {
 339                 int nth, i;
 340                 unsigned long at_time;
 341                 unsigned long co_time;
 342                 int co_tz, co_cnt;
 343
 344                 /* Is it asking for N-th entry, or approxidate? */
 345                 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
 346                         char ch = str[at+2+i];
 347                         if ('0' <= ch && ch <= '9')
 348                                 nth = nth * 10 + ch - '0';
 349                         else
 350                                 nth = -1;
 351                 }
 352                 if (0 <= nth)
 353                         at_time = 0;
 354                 else
 355                         at_time = approxidate(str + at + 2);
 356                 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
 357                                 &co_time, &co_tz, &co_cnt)) {
 358                         if (at_time)
 359                                 fprintf(stderr,
 360                                         "warning: Log for '%.*s' only goes "
 361                                         "back to %s.\n", len, str,
 362                                         show_date(co_time, co_tz, DATE_RFC2822));
 363                         else
 364                                 fprintf(stderr,
 365                                         "warning: Log for '%.*s' only has "
 366                                         "%d entries.\n", len, str, co_cnt);
 367                 }
 368         }
 369
 370         free(real_ref);
 371         return 0;
 372 }
 373
 374 static int get_sha1_1(const char *name, int len, unsigned char *sha1);
 375
 376 static int get_parent(const char *name, int len,
 377                       unsigned char *result, int idx)
 378 {
 379         unsigned char sha1[20];
 380         int ret = get_sha1_1(name, len, sha1);
 381         struct commit *commit;
 382         struct commit_list *p;
 383
 384         if (ret)
 385                 return ret;
 386         commit = lookup_commit_reference(sha1);
 387         if (!commit)
 388                 return -1;
 389         if (parse_commit(commit))
 390                 return -1;
 391         if (!idx) {
 392                 hashcpy(result, commit->object.sha1);
 393                 return 0;
 394         }
 395         p = commit->parents;
 396         while (p) {
 397                 if (!--idx) {
 398                         hashcpy(result, p->item->object.sha1);
 399                         return 0;
 400                 }
 401                 p = p->next;
 402         }
 403         return -1;
 404 }
 405
 406 static int get_nth_ancestor(const char *name, int len,
 407                             unsigned char *result, int generation)
 408 {
 409         unsigned char sha1[20];
 410         int ret = get_sha1_1(name, len, sha1);
 411         if (ret)
 412                 return ret;
 413
 414         while (generation--) {
 415                 struct commit *commit = lookup_commit_reference(sha1);
 416
 417                 if (!commit || parse_commit(commit) || !commit->parents)
 418                         return -1;
 419                 hashcpy(sha1, commit->parents->item->object.sha1);
 420         }
 421         hashcpy(result, sha1);
 422         return 0;
 423 }
 424
 425 static int peel_onion(const char *name, int len, unsigned char *sha1)
 426 {
 427         unsigned char outer[20];
 428         const char *sp;
 429         unsigned int expected_type = 0;
 430         struct object *o;
 431
 432         /*
 433          * "ref^{type}" dereferences ref repeatedly until you cannot
 434          * dereference anymore, or you get an object of given type,
 435          * whichever comes first.  "ref^{}" means just dereference
 436          * tags until you get a non-tag.  "ref^0" is a shorthand for
 437          * "ref^{commit}".  "commit^{tree}" could be used to find the
 438          * top-level tree of the given commit.
 439          */
 440         if (len < 4 || name[len-1] != '}')
 441                 return -1;
 442
 443         for (sp = name + len - 1; name <= sp; sp--) {
 444                 int ch = *sp;
 445                 if (ch == '{' && name < sp && sp[-1] == '^')
 446                         break;
 447         }
 448         if (sp <= name)
 449                 return -1;
 450
 451         sp++; /* beginning of type name, or closing brace for empty */
 452         if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
 453                 expected_type = OBJ_COMMIT;
 454         else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
 455                 expected_type = OBJ_TREE;
 456         else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
 457                 expected_type = OBJ_BLOB;
 458         else if (sp[0] == '}')
 459                 expected_type = OBJ_NONE;
 460         else
 461                 return -1;
 462
 463         if (get_sha1_1(name, sp - name - 2, outer))
 464                 return -1;
 465
 466         o = parse_object(outer);
 467         if (!o)
 468                 return -1;
 469         if (!expected_type) {
 470                 o = deref_tag(o, name, sp - name - 2);
 471                 if (!o || (!o->parsed && !parse_object(o->sha1)))
 472                         return -1;
 473                 hashcpy(sha1, o->sha1);
 474         }
 475         else {
 476                 /* At this point, the syntax look correct, so
 477                  * if we do not get the needed object, we should
 478                  * barf.
 479                  */
 480
 481                 while (1) {
 482                         if (!o || (!o->parsed && !parse_object(o->sha1)))
 483                                 return -1;
 484                         if (o->type == expected_type) {
 485                                 hashcpy(sha1, o->sha1);
 486                                 return 0;
 487                         }
 488                         if (o->type == OBJ_TAG)
 489                                 o = ((struct tag*) o)->tagged;
 490                         else if (o->type == OBJ_COMMIT)
 491                                 o = &(((struct commit *) o)->tree->object);
 492                         else
 493                                 return error("%.*s: expected %s type, but the object dereferences to %s type",
 494                                              len, name, typename(expected_type),
 495                                              typename(o->type));
 496                         if (!o)
 497                                 return -1;
 498                         if (!o->parsed)
 499                                 if (!parse_object(o->sha1))
 500                                         return -1;
 501                 }
 502         }
 503         return 0;
 504 }
 505
 506 static int get_describe_name(const char *name, int len, unsigned char *sha1)
 507 {
 508         const char *cp;
 509
 510         for (cp = name + len - 1; name + 2 <= cp; cp--) {
 511                 char ch = *cp;
 512                 if (hexval(ch) & ~0377) {
 513                         /* We must be looking at g in "SOMETHING-g"
 514                          * for it to be describe output.
 515                          */
 516                         if (ch == 'g' && cp[-1] == '-') {
 517                                 cp++;
 518                                 len -= cp - name;
 519                                 return get_short_sha1(cp, len, sha1, 1);
 520                         }
 521                 }
 522         }
 523         return -1;
 524 }
 525
 526 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
 527 {
 528         int ret, has_suffix;
 529         const char *cp;
 530
 531         /* "name~3" is "name^^^",
 532          * "name~" and "name~0" are name -- not "name^0"!
 533          * "name^" is not "name^0"; it is "name^1".
 534          */
 535         has_suffix = 0;
 536         for (cp = name + len - 1; name <= cp; cp--) {
 537                 int ch = *cp;
 538                 if ('0' <= ch && ch <= '9')
 539                         continue;
 540                 if (ch == '~' || ch == '^')
 541                         has_suffix = ch;
 542                 break;
 543         }
 544
 545         if (has_suffix) {
 546                 int num = 0;
 547                 int len1 = cp - name;
 548                 cp++;
 549                 while (cp < name + len)
 550                         num = num * 10 + *cp++ - '0';
 551                 if (has_suffix == '^') {
 552                         if (!num && len1 == len - 1)
 553                                 num = 1;
 554                         return get_parent(name, len1, sha1, num);
 555                 }
 556                 /* else if (has_suffix == '~') -- goes without saying */
 557                 return get_nth_ancestor(name, len1, sha1, num);
 558         }
 559
 560         ret = peel_onion(name, len, sha1);
 561         if (!ret)
 562                 return 0;
 563
 564         ret = get_sha1_basic(name, len, sha1);
 565         if (!ret)
 566                 return 0;
 567
 568         /* It could be describe output that is "SOMETHING-gXXXX" */
 569         ret = get_describe_name(name, len, sha1);
 570         if (!ret)
 571                 return 0;
 572
 573         return get_short_sha1(name, len, sha1, 0);
 574 }
 575
 576 static int handle_one_ref(const char *path,
 577                 const unsigned char *sha1, int flag, void *cb_data)
 578 {
 579         struct commit_list **list = cb_data;
 580         struct object *object = parse_object(sha1);
 581         if (!object)
 582                 return 0;
 583         if (object->type == OBJ_TAG) {
 584                 object = deref_tag(object, path, strlen(path));
 585                 if (!object)
 586                         return 0;
 587         }
 588         if (object->type != OBJ_COMMIT)
 589                 return 0;
 590         insert_by_date((struct commit *)object, list);
 591         return 0;
 592 }
 593
 594 /*
 595  * This interprets names like ':/Initial revision of "git"' by searching
 596  * through history and returning the first commit whose message starts
 597  * with the given string.
 598  *
 599  * For future extension, ':/!' is reserved. If you want to match a message
 600  * beginning with a '!', you have to repeat the exclamation mark.
 601  */
 602
 603 #define ONELINE_SEEN (1u<<20)
 604 static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
 605 {
 606         struct commit_list *list = NULL, *backup = NULL, *l;
 607         int retval = -1;
 608         char *temp_commit_buffer = NULL;
 609
 610         if (prefix[0] == '!') {
 611                 if (prefix[1] != '!')
 612                         die ("Invalid search pattern: %s", prefix);
 613                 prefix++;
 614         }
 615         for_each_ref(handle_one_ref, &list);
 616         for (l = list; l; l = l->next)
 617                 commit_list_insert(l->item, &backup);
 618         while (list) {
 619                 char *p;
 620                 struct commit *commit;
 621                 enum object_type type;
 622                 unsigned long size;
 623
 624                 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
 625                 if (!parse_object(commit->object.sha1))
 626                         continue;
 627                 free(temp_commit_buffer);
 628                 if (commit->buffer)
 629                         p = commit->buffer;
 630                 else {
 631                         p = read_sha1_file(commit->object.sha1, &type, &size);
 632                         if (!p)
 633                                 continue;
 634                         temp_commit_buffer = p;
 635                 }
 636                 if (!(p = strstr(p, "\n\n")))
 637                         continue;
 638                 if (!prefixcmp(p + 2, prefix)) {
 639                         hashcpy(sha1, commit->object.sha1);
 640                         retval = 0;
 641                         break;
 642                 }
 643         }
 644         free(temp_commit_buffer);
 645         free_commit_list(list);
 646         for (l = backup; l; l = l->next)
 647                 clear_commit_marks(l->item, ONELINE_SEEN);
 648         return retval;
 649 }
 650
 651 /*
 652  * This is like "get_sha1_basic()", except it allows "sha1 expressions",
 653  * notably "xyz^" for "parent of xyz"
 654  */
 655 int get_sha1(const char *name, unsigned char *sha1)
 656 {
 657         unsigned unused;
 658         return get_sha1_with_mode(name, sha1, &unused);
 659 }
 660
 661 int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode)
 662 {
 663         int ret, bracket_depth;
 664         int namelen = strlen(name);
 665         const char *cp;
 666
 667         *mode = S_IFINVALID;
 668         ret = get_sha1_1(name, namelen, sha1);
 669         if (!ret)
 670                 return ret;
 671         /* sha1:path --> object name of path in ent sha1
 672          * :path -> object name of path in index
 673          * :[0-3]:path -> object name of path in index at stage
 674          */
 675         if (name[0] == ':') {
 676                 int stage = 0;
 677                 struct cache_entry *ce;
 678                 int pos;
 679                 if (namelen > 2 && name[1] == '/')
 680                         return get_sha1_oneline(name + 2, sha1);
 681                 if (namelen < 3 ||
 682                     name[2] != ':' ||
 683                     name[1] < '0' || '3' < name[1])
 684                         cp = name + 1;
 685                 else {
 686                         stage = name[1] - '0';
 687                         cp = name + 3;
 688                 }
 689                 namelen = namelen - (cp - name);
 690                 if (!active_cache)
 691                         read_cache();
 692                 pos = cache_name_pos(cp, namelen);
 693                 if (pos < 0)
 694                         pos = -pos - 1;
 695                 while (pos < active_nr) {
 696                         ce = active_cache[pos];
 697                         if (ce_namelen(ce) != namelen ||
 698                             memcmp(ce->name, cp, namelen))
 699                                 break;
 700                         if (ce_stage(ce) == stage) {
 701                                 hashcpy(sha1, ce->sha1);
 702                                 *mode = ce->ce_mode;
 703                                 return 0;
 704                         }
 705                         pos++;
 706                 }
 707                 return -1;
 708         }
 709         for (cp = name, bracket_depth = 0; *cp; cp++) {
 710                 if (*cp == '{')
 711                         bracket_depth++;
 712                 else if (bracket_depth && *cp == '}')
 713                         bracket_depth--;
 714                 else if (!bracket_depth && *cp == ':')
 715                         break;
 716         }
 717         if (*cp == ':') {
 718                 unsigned char tree_sha1[20];
 719                 if (!get_sha1_1(name, cp-name, tree_sha1))
 720                         return get_tree_entry(tree_sha1, cp+1, sha1,
 721                                               mode);
 722         }
 723         return ret;
 724 }