git.oblomov.eu Git - git/blob - cache-tree.c

   1 #include "cache.h"
   2 #include "tree.h"
   3 #include "tree-walk.h"
   4 #include "cache-tree.h"
   5
   6 #ifndef DEBUG
   7 #define DEBUG 0
   8 #endif
   9
  10 struct cache_tree *cache_tree(void)
  11 {
  12         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  13         it->entry_count = -1;
  14         return it;
  15 }
  16
  17 void cache_tree_free(struct cache_tree **it_p)
  18 {
  19         int i;
  20         struct cache_tree *it = *it_p;
  21
  22         if (!it)
  23                 return;
  24         for (i = 0; i < it->subtree_nr; i++)
  25                 if (it->down[i]) {
  26                         cache_tree_free(&it->down[i]->cache_tree);
  27                         free(it->down[i]);
  28                 }
  29         free(it->down);
  30         free(it);
  31         *it_p = NULL;
  32 }
  33
  34 static int subtree_name_cmp(const char *one, int onelen,
  35                             const char *two, int twolen)
  36 {
  37         if (onelen < twolen)
  38                 return -1;
  39         if (twolen < onelen)
  40                 return 1;
  41         return memcmp(one, two, onelen);
  42 }
  43
  44 static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  45 {
  46         struct cache_tree_sub **down = it->down;
  47         int lo, hi;
  48         lo = 0;
  49         hi = it->subtree_nr;
  50         while (lo < hi) {
  51                 int mi = (lo + hi) / 2;
  52                 struct cache_tree_sub *mdl = down[mi];
  53                 int cmp = subtree_name_cmp(path, pathlen,
  54                                            mdl->name, mdl->namelen);
  55                 if (!cmp)
  56                         return mi;
  57                 if (cmp < 0)
  58                         hi = mi;
  59                 else
  60                         lo = mi + 1;
  61         }
  62         return -lo-1;
  63 }
  64
  65 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  66                                            const char *path,
  67                                            int pathlen,
  68                                            int create)
  69 {
  70         struct cache_tree_sub *down;
  71         int pos = subtree_pos(it, path, pathlen);
  72         if (0 <= pos)
  73                 return it->down[pos];
  74         if (!create)
  75                 return NULL;
  76
  77         pos = -pos-1;
  78         ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
  79         it->subtree_nr++;
  80
  81         down = xmalloc(sizeof(*down) + pathlen + 1);
  82         down->cache_tree = NULL;
  83         down->namelen = pathlen;
  84         memcpy(down->name, path, pathlen);
  85         down->name[pathlen] = 0;
  86
  87         if (pos < it->subtree_nr)
  88                 memmove(it->down + pos + 1,
  89                         it->down + pos,
  90                         sizeof(down) * (it->subtree_nr - pos - 1));
  91         it->down[pos] = down;
  92         return down;
  93 }
  94
  95 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
  96 {
  97         int pathlen = strlen(path);
  98         return find_subtree(it, path, pathlen, 1);
  99 }
 100
 101 static int do_invalidate_path(struct cache_tree *it, const char *path)
 102 {
 103         /* a/b/c
 104          * ==> invalidate self
 105          * ==> find "a", have it invalidate "b/c"
 106          * a
 107          * ==> invalidate self
 108          * ==> if "a" exists as a subtree, remove it.
 109          */
 110         const char *slash;
 111         int namelen;
 112         struct cache_tree_sub *down;
 113
 114 #if DEBUG
 115         fprintf(stderr, "cache-tree invalidate <%s>\n", path);
 116 #endif
 117
 118         if (!it)
 119                 return 0;
 120         slash = strchrnul(path, '/');
 121         namelen = slash - path;
 122         it->entry_count = -1;
 123         if (!*slash) {
 124                 int pos;
 125                 pos = subtree_pos(it, path, namelen);
 126                 if (0 <= pos) {
 127                         cache_tree_free(&it->down[pos]->cache_tree);
 128                         free(it->down[pos]);
 129                         /* 0 1 2 3 4 5
 130                          *       ^     ^subtree_nr = 6
 131                          *       pos
 132                          * move 4 and 5 up one place (2 entries)
 133                          * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 134                          */
 135                         memmove(it->down+pos, it->down+pos+1,
 136                                 sizeof(struct cache_tree_sub *) *
 137                                 (it->subtree_nr - pos - 1));
 138                         it->subtree_nr--;
 139                 }
 140                 return 1;
 141         }
 142         down = find_subtree(it, path, namelen, 0);
 143         if (down)
 144                 do_invalidate_path(down->cache_tree, slash + 1);
 145         return 1;
 146 }
 147
 148 void cache_tree_invalidate_path(struct index_state *istate, const char *path)
 149 {
 150         if (do_invalidate_path(istate->cache_tree, path))
 151                 istate->cache_changed |= CACHE_TREE_CHANGED;
 152 }
 153
 154 static int verify_cache(struct cache_entry **cache,
 155                         int entries, int flags)
 156 {
 157         int i, funny;
 158         int silent = flags & WRITE_TREE_SILENT;
 159
 160         /* Verify that the tree is merged */
 161         funny = 0;
 162         for (i = 0; i < entries; i++) {
 163                 const struct cache_entry *ce = cache[i];
 164                 if (ce_stage(ce)) {
 165                         if (silent)
 166                                 return -1;
 167                         if (10 < ++funny) {
 168                                 fprintf(stderr, "...\n");
 169                                 break;
 170                         }
 171                         fprintf(stderr, "%s: unmerged (%s)\n",
 172                                 ce->name, sha1_to_hex(ce->sha1));
 173                 }
 174         }
 175         if (funny)
 176                 return -1;
 177
 178         /* Also verify that the cache does not have path and path/file
 179          * at the same time.  At this point we know the cache has only
 180          * stage 0 entries.
 181          */
 182         funny = 0;
 183         for (i = 0; i < entries - 1; i++) {
 184                 /* path/file always comes after path because of the way
 185                  * the cache is sorted.  Also path can appear only once,
 186                  * which means conflicting one would immediately follow.
 187                  */
 188                 const char *this_name = cache[i]->name;
 189                 const char *next_name = cache[i+1]->name;
 190                 int this_len = strlen(this_name);
 191                 if (this_len < strlen(next_name) &&
 192                     strncmp(this_name, next_name, this_len) == 0 &&
 193                     next_name[this_len] == '/') {
 194                         if (10 < ++funny) {
 195                                 fprintf(stderr, "...\n");
 196                                 break;
 197                         }
 198                         fprintf(stderr, "You have both %s and %s\n",
 199                                 this_name, next_name);
 200                 }
 201         }
 202         if (funny)
 203                 return -1;
 204         return 0;
 205 }
 206
 207 static void discard_unused_subtrees(struct cache_tree *it)
 208 {
 209         struct cache_tree_sub **down = it->down;
 210         int nr = it->subtree_nr;
 211         int dst, src;
 212         for (dst = src = 0; src < nr; src++) {
 213                 struct cache_tree_sub *s = down[src];
 214                 if (s->used)
 215                         down[dst++] = s;
 216                 else {
 217                         cache_tree_free(&s->cache_tree);
 218                         free(s);
 219                         it->subtree_nr--;
 220                 }
 221         }
 222 }
 223
 224 int cache_tree_fully_valid(struct cache_tree *it)
 225 {
 226         int i;
 227         if (!it)
 228                 return 0;
 229         if (it->entry_count < 0 || !has_sha1_file(it->sha1))
 230                 return 0;
 231         for (i = 0; i < it->subtree_nr; i++) {
 232                 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
 233                         return 0;
 234         }
 235         return 1;
 236 }
 237
 238 static int update_one(struct cache_tree *it,
 239                       struct cache_entry **cache,
 240                       int entries,
 241                       const char *base,
 242                       int baselen,
 243                       int *skip_count,
 244                       int flags)
 245 {
 246         struct strbuf buffer;
 247         int missing_ok = flags & WRITE_TREE_MISSING_OK;
 248         int dryrun = flags & WRITE_TREE_DRY_RUN;
 249         int repair = flags & WRITE_TREE_REPAIR;
 250         int to_invalidate = 0;
 251         int i;
 252
 253         assert(!(dryrun && repair));
 254
 255         *skip_count = 0;
 256
 257         if (0 <= it->entry_count && has_sha1_file(it->sha1))
 258                 return it->entry_count;
 259
 260         /*
 261          * We first scan for subtrees and update them; we start by
 262          * marking existing subtrees -- the ones that are unmarked
 263          * should not be in the result.
 264          */
 265         for (i = 0; i < it->subtree_nr; i++)
 266                 it->down[i]->used = 0;
 267
 268         /*
 269          * Find the subtrees and update them.
 270          */
 271         i = 0;
 272         while (i < entries) {
 273                 const struct cache_entry *ce = cache[i];
 274                 struct cache_tree_sub *sub;
 275                 const char *path, *slash;
 276                 int pathlen, sublen, subcnt, subskip;
 277
 278                 path = ce->name;
 279                 pathlen = ce_namelen(ce);
 280                 if (pathlen <= baselen || memcmp(base, path, baselen))
 281                         break; /* at the end of this level */
 282
 283                 slash = strchr(path + baselen, '/');
 284                 if (!slash) {
 285                         i++;
 286                         continue;
 287                 }
 288                 /*
 289                  * a/bbb/c (base = a/, slash = /c)
 290                  * ==>
 291                  * path+baselen = bbb/c, sublen = 3
 292                  */
 293                 sublen = slash - (path + baselen);
 294                 sub = find_subtree(it, path + baselen, sublen, 1);
 295                 if (!sub->cache_tree)
 296                         sub->cache_tree = cache_tree();
 297                 subcnt = update_one(sub->cache_tree,
 298                                     cache + i, entries - i,
 299                                     path,
 300                                     baselen + sublen + 1,
 301                                     &subskip,
 302                                     flags);
 303                 if (subcnt < 0)
 304                         return subcnt;
 305                 i += subcnt;
 306                 sub->count = subcnt; /* to be used in the next loop */
 307                 *skip_count += subskip;
 308                 sub->used = 1;
 309         }
 310
 311         discard_unused_subtrees(it);
 312
 313         /*
 314          * Then write out the tree object for this level.
 315          */
 316         strbuf_init(&buffer, 8192);
 317
 318         i = 0;
 319         while (i < entries) {
 320                 const struct cache_entry *ce = cache[i];
 321                 struct cache_tree_sub *sub;
 322                 const char *path, *slash;
 323                 int pathlen, entlen;
 324                 const unsigned char *sha1;
 325                 unsigned mode;
 326                 int expected_missing = 0;
 327
 328                 path = ce->name;
 329                 pathlen = ce_namelen(ce);
 330                 if (pathlen <= baselen || memcmp(base, path, baselen))
 331                         break; /* at the end of this level */
 332
 333                 slash = strchr(path + baselen, '/');
 334                 if (slash) {
 335                         entlen = slash - (path + baselen);
 336                         sub = find_subtree(it, path + baselen, entlen, 0);
 337                         if (!sub)
 338                                 die("cache-tree.c: '%.*s' in '%s' not found",
 339                                     entlen, path + baselen, path);
 340                         i += sub->count;
 341                         sha1 = sub->cache_tree->sha1;
 342                         mode = S_IFDIR;
 343                         if (sub->cache_tree->entry_count < 0) {
 344                                 to_invalidate = 1;
 345                                 expected_missing = 1;
 346                         }
 347                 }
 348                 else {
 349                         sha1 = ce->sha1;
 350                         mode = ce->ce_mode;
 351                         entlen = pathlen - baselen;
 352                         i++;
 353                 }
 354                 if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1)) {
 355                         strbuf_release(&buffer);
 356                         if (expected_missing)
 357                                 return -1;
 358                         return error("invalid object %06o %s for '%.*s'",
 359                                 mode, sha1_to_hex(sha1), entlen+baselen, path);
 360                 }
 361
 362                 /*
 363                  * CE_REMOVE entries are removed before the index is
 364                  * written to disk. Skip them to remain consistent
 365                  * with the future on-disk index.
 366                  */
 367                 if (ce->ce_flags & CE_REMOVE) {
 368                         *skip_count = *skip_count + 1;
 369                         continue;
 370                 }
 371
 372                 /*
 373                  * CE_INTENT_TO_ADD entries exist on on-disk index but
 374                  * they are not part of generated trees. Invalidate up
 375                  * to root to force cache-tree users to read elsewhere.
 376                  */
 377                 if (ce->ce_flags & CE_INTENT_TO_ADD) {
 378                         to_invalidate = 1;
 379                         continue;
 380                 }
 381
 382                 strbuf_grow(&buffer, entlen + 100);
 383                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
 384                 strbuf_add(&buffer, sha1, 20);
 385
 386 #if DEBUG
 387                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
 388                         mode, entlen, path + baselen);
 389 #endif
 390         }
 391
 392         if (repair) {
 393                 unsigned char sha1[20];
 394                 hash_sha1_file(buffer.buf, buffer.len, tree_type, sha1);
 395                 if (has_sha1_file(sha1))
 396                         hashcpy(it->sha1, sha1);
 397                 else
 398                         to_invalidate = 1;
 399         } else if (dryrun)
 400                 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
 401         else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
 402                 strbuf_release(&buffer);
 403                 return -1;
 404         }
 405
 406         strbuf_release(&buffer);
 407         it->entry_count = to_invalidate ? -1 : i - *skip_count;
 408 #if DEBUG
 409         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
 410                 it->entry_count, it->subtree_nr,
 411                 sha1_to_hex(it->sha1));
 412 #endif
 413         return i;
 414 }
 415
 416 int cache_tree_update(struct index_state *istate, int flags)
 417 {
 418         struct cache_tree *it = istate->cache_tree;
 419         struct cache_entry **cache = istate->cache;
 420         int entries = istate->cache_nr;
 421         int skip, i = verify_cache(cache, entries, flags);
 422
 423         if (i)
 424                 return i;
 425         i = update_one(it, cache, entries, "", 0, &skip, flags);
 426         if (i < 0)
 427                 return i;
 428         istate->cache_changed |= CACHE_TREE_CHANGED;
 429         return 0;
 430 }
 431
 432 static void write_one(struct strbuf *buffer, struct cache_tree *it,
 433                       const char *path, int pathlen)
 434 {
 435         int i;
 436
 437         /* One "cache-tree" entry consists of the following:
 438          * path (NUL terminated)
 439          * entry_count, subtree_nr ("%d %d\n")
 440          * tree-sha1 (missing if invalid)
 441          * subtree_nr "cache-tree" entries for subtrees.
 442          */
 443         strbuf_grow(buffer, pathlen + 100);
 444         strbuf_add(buffer, path, pathlen);
 445         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 446
 447 #if DEBUG
 448         if (0 <= it->entry_count)
 449                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 450                         pathlen, path, it->entry_count, it->subtree_nr,
 451                         sha1_to_hex(it->sha1));
 452         else
 453                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 454                         pathlen, path, it->subtree_nr);
 455 #endif
 456
 457         if (0 <= it->entry_count) {
 458                 strbuf_add(buffer, it->sha1, 20);
 459         }
 460         for (i = 0; i < it->subtree_nr; i++) {
 461                 struct cache_tree_sub *down = it->down[i];
 462                 if (i) {
 463                         struct cache_tree_sub *prev = it->down[i-1];
 464                         if (subtree_name_cmp(down->name, down->namelen,
 465                                              prev->name, prev->namelen) <= 0)
 466                                 die("fatal - unsorted cache subtree");
 467                 }
 468                 write_one(buffer, down->cache_tree, down->name, down->namelen);
 469         }
 470 }
 471
 472 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
 473 {
 474         write_one(sb, root, "", 0);
 475 }
 476
 477 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 478 {
 479         const char *buf = *buffer;
 480         unsigned long size = *size_p;
 481         const char *cp;
 482         char *ep;
 483         struct cache_tree *it;
 484         int i, subtree_nr;
 485
 486         it = NULL;
 487         /* skip name, but make sure name exists */
 488         while (size && *buf) {
 489                 size--;
 490                 buf++;
 491         }
 492         if (!size)
 493                 goto free_return;
 494         buf++; size--;
 495         it = cache_tree();
 496
 497         cp = buf;
 498         it->entry_count = strtol(cp, &ep, 10);
 499         if (cp == ep)
 500                 goto free_return;
 501         cp = ep;
 502         subtree_nr = strtol(cp, &ep, 10);
 503         if (cp == ep)
 504                 goto free_return;
 505         while (size && *buf && *buf != '\n') {
 506                 size--;
 507                 buf++;
 508         }
 509         if (!size)
 510                 goto free_return;
 511         buf++; size--;
 512         if (0 <= it->entry_count) {
 513                 if (size < 20)
 514                         goto free_return;
 515                 hashcpy(it->sha1, (const unsigned char*)buf);
 516                 buf += 20;
 517                 size -= 20;
 518         }
 519
 520 #if DEBUG
 521         if (0 <= it->entry_count)
 522                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 523                         *buffer, it->entry_count, subtree_nr,
 524                         sha1_to_hex(it->sha1));
 525         else
 526                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 527                         *buffer, subtree_nr);
 528 #endif
 529
 530         /*
 531          * Just a heuristic -- we do not add directories that often but
 532          * we do not want to have to extend it immediately when we do,
 533          * hence +2.
 534          */
 535         it->subtree_alloc = subtree_nr + 2;
 536         it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
 537         for (i = 0; i < subtree_nr; i++) {
 538                 /* read each subtree */
 539                 struct cache_tree *sub;
 540                 struct cache_tree_sub *subtree;
 541                 const char *name = buf;
 542
 543                 sub = read_one(&buf, &size);
 544                 if (!sub)
 545                         goto free_return;
 546                 subtree = cache_tree_sub(it, name);
 547                 subtree->cache_tree = sub;
 548         }
 549         if (subtree_nr != it->subtree_nr)
 550                 die("cache-tree: internal error");
 551         *buffer = buf;
 552         *size_p = size;
 553         return it;
 554
 555  free_return:
 556         cache_tree_free(&it);
 557         return NULL;
 558 }
 559
 560 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 561 {
 562         if (buffer[0])
 563                 return NULL; /* not the whole tree */
 564         return read_one(&buffer, &size);
 565 }
 566
 567 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 568 {
 569         if (!it)
 570                 return NULL;
 571         while (*path) {
 572                 const char *slash;
 573                 struct cache_tree_sub *sub;
 574
 575                 slash = strchrnul(path, '/');
 576                 /*
 577                  * Between path and slash is the name of the subtree
 578                  * to look for.
 579                  */
 580                 sub = find_subtree(it, path, slash - path, 0);
 581                 if (!sub)
 582                         return NULL;
 583                 it = sub->cache_tree;
 584
 585                 path = slash;
 586                 while (*path == '/')
 587                         path++;
 588         }
 589         return it;
 590 }
 591
 592 int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
 593 {
 594         int entries, was_valid, newfd;
 595         struct lock_file *lock_file;
 596
 597         /*
 598          * We can't free this memory, it becomes part of a linked list
 599          * parsed atexit()
 600          */
 601         lock_file = xcalloc(1, sizeof(struct lock_file));
 602
 603         newfd = hold_locked_index(lock_file, 1);
 604
 605         entries = read_cache();
 606         if (entries < 0)
 607                 return WRITE_TREE_UNREADABLE_INDEX;
 608         if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
 609                 cache_tree_free(&(active_cache_tree));
 610
 611         if (!active_cache_tree)
 612                 active_cache_tree = cache_tree();
 613
 614         was_valid = cache_tree_fully_valid(active_cache_tree);
 615         if (!was_valid) {
 616                 if (cache_tree_update(&the_index, flags) < 0)
 617                         return WRITE_TREE_UNMERGED_INDEX;
 618                 if (0 <= newfd) {
 619                         if (!write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 620                                 newfd = -1;
 621                 }
 622                 /* Not being able to write is fine -- we are only interested
 623                  * in updating the cache-tree part, and if the next caller
 624                  * ends up using the old index with unupdated cache-tree part
 625                  * it misses the work we did here, but that is just a
 626                  * performance penalty and not a big deal.
 627                  */
 628         }
 629
 630         if (prefix) {
 631                 struct cache_tree *subtree =
 632                         cache_tree_find(active_cache_tree, prefix);
 633                 if (!subtree)
 634                         return WRITE_TREE_PREFIX_ERROR;
 635                 hashcpy(sha1, subtree->sha1);
 636         }
 637         else
 638                 hashcpy(sha1, active_cache_tree->sha1);
 639
 640         if (0 <= newfd)
 641                 rollback_lock_file(lock_file);
 642
 643         return 0;
 644 }
 645
 646 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
 647 {
 648         struct tree_desc desc;
 649         struct name_entry entry;
 650         int cnt;
 651
 652         hashcpy(it->sha1, tree->object.sha1);
 653         init_tree_desc(&desc, tree->buffer, tree->size);
 654         cnt = 0;
 655         while (tree_entry(&desc, &entry)) {
 656                 if (!S_ISDIR(entry.mode))
 657                         cnt++;
 658                 else {
 659                         struct cache_tree_sub *sub;
 660                         struct tree *subtree = lookup_tree(entry.sha1);
 661                         if (!subtree->object.parsed)
 662                                 parse_tree(subtree);
 663                         sub = cache_tree_sub(it, entry.path);
 664                         sub->cache_tree = cache_tree();
 665                         prime_cache_tree_rec(sub->cache_tree, subtree);
 666                         cnt += sub->cache_tree->entry_count;
 667                 }
 668         }
 669         it->entry_count = cnt;
 670 }
 671
 672 void prime_cache_tree(struct index_state *istate, struct tree *tree)
 673 {
 674         cache_tree_free(&istate->cache_tree);
 675         istate->cache_tree = cache_tree();
 676         prime_cache_tree_rec(istate->cache_tree, tree);
 677         istate->cache_changed |= CACHE_TREE_CHANGED;
 678 }
 679
 680 /*
 681  * find the cache_tree that corresponds to the current level without
 682  * exploding the full path into textual form.  The root of the
 683  * cache tree is given as "root", and our current level is "info".
 684  * (1) When at root level, info->prev is NULL, so it is "root" itself.
 685  * (2) Otherwise, find the cache_tree that corresponds to one level
 686  *     above us, and find ourselves in there.
 687  */
 688 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
 689                                                          struct traverse_info *info)
 690 {
 691         struct cache_tree *our_parent;
 692
 693         if (!info->prev)
 694                 return root;
 695         our_parent = find_cache_tree_from_traversal(root, info->prev);
 696         return cache_tree_find(our_parent, info->name.path);
 697 }
 698
 699 int cache_tree_matches_traversal(struct cache_tree *root,
 700                                  struct name_entry *ent,
 701                                  struct traverse_info *info)
 702 {
 703         struct cache_tree *it;
 704
 705         it = find_cache_tree_from_traversal(root, info);
 706         it = cache_tree_find(it, ent->path);
 707         if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))
 708                 return it->entry_count;
 709         return 0;
 710 }
 711
 712 int update_main_cache_tree(int flags)
 713 {
 714         if (!the_index.cache_tree)
 715                 the_index.cache_tree = cache_tree();
 716         return cache_tree_update(&the_index, flags);
 717 }