cache-tree.c

   1 #include "cache.h"
   2 #include "lockfile.h"
   3 #include "tree.h"
   4 #include "tree-walk.h"
   5 #include "cache-tree.h"
   6 #include "object-store.h"
   7 #include "replace-object.h"
   8
   9 #ifndef DEBUG
  10 #define DEBUG 0
  11 #endif
  12
  13 struct cache_tree *cache_tree(void)
  14 {
  15         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  16         it->entry_count = -1;
  17         return it;
  18 }
  19
  20 void cache_tree_free(struct cache_tree **it_p)
  21 {
  22         int i;
  23         struct cache_tree *it = *it_p;
  24
  25         if (!it)
  26                 return;
  27         for (i = 0; i < it->subtree_nr; i++)
  28                 if (it->down[i]) {
  29                         cache_tree_free(&it->down[i]->cache_tree);
  30                         free(it->down[i]);
  31                 }
  32         free(it->down);
  33         free(it);
  34         *it_p = NULL;
  35 }
  36
  37 static int subtree_name_cmp(const char *one, int onelen,
  38                             const char *two, int twolen)
  39 {
  40         if (onelen < twolen)
  41                 return -1;
  42         if (twolen < onelen)
  43                 return 1;
  44         return memcmp(one, two, onelen);
  45 }
  46
  47 static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  48 {
  49         struct cache_tree_sub **down = it->down;
  50         int lo, hi;
  51         lo = 0;
  52         hi = it->subtree_nr;
  53         while (lo < hi) {
  54                 int mi = lo + (hi - lo) / 2;
  55                 struct cache_tree_sub *mdl = down[mi];
  56                 int cmp = subtree_name_cmp(path, pathlen,
  57                                            mdl->name, mdl->namelen);
  58                 if (!cmp)
  59                         return mi;
  60                 if (cmp < 0)
  61                         hi = mi;
  62                 else
  63                         lo = mi + 1;
  64         }
  65         return -lo-1;
  66 }
  67
  68 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  69                                            const char *path,
  70                                            int pathlen,
  71                                            int create)
  72 {
  73         struct cache_tree_sub *down;
  74         int pos = subtree_pos(it, path, pathlen);
  75         if (0 <= pos)
  76                 return it->down[pos];
  77         if (!create)
  78                 return NULL;
  79
  80         pos = -pos-1;
  81         ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
  82         it->subtree_nr++;
  83
  84         FLEX_ALLOC_MEM(down, name, path, pathlen);
  85         down->cache_tree = NULL;
  86         down->namelen = pathlen;
  87
  88         if (pos < it->subtree_nr)
  89                 MOVE_ARRAY(it->down + pos + 1, it->down + pos,
  90                            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                         MOVE_ARRAY(it->down + pos, it->down + pos + 1,
 136                                    it->subtree_nr - pos - 1);
 137                         it->subtree_nr--;
 138                 }
 139                 return 1;
 140         }
 141         down = find_subtree(it, path, namelen, 0);
 142         if (down)
 143                 do_invalidate_path(down->cache_tree, slash + 1);
 144         return 1;
 145 }
 146
 147 void cache_tree_invalidate_path(struct index_state *istate, const char *path)
 148 {
 149         if (do_invalidate_path(istate->cache_tree, path))
 150                 istate->cache_changed |= CACHE_TREE_CHANGED;
 151 }
 152
 153 static int verify_cache(struct cache_entry **cache,
 154                         int entries, int flags)
 155 {
 156         int i, funny;
 157         int silent = flags & WRITE_TREE_SILENT;
 158
 159         /* Verify that the tree is merged */
 160         funny = 0;
 161         for (i = 0; i < entries; i++) {
 162                 const struct cache_entry *ce = cache[i];
 163                 if (ce_stage(ce)) {
 164                         if (silent)
 165                                 return -1;
 166                         if (10 < ++funny) {
 167                                 fprintf(stderr, "...\n");
 168                                 break;
 169                         }
 170                         fprintf(stderr, "%s: unmerged (%s)\n",
 171                                 ce->name, oid_to_hex(&ce->oid));
 172                 }
 173         }
 174         if (funny)
 175                 return -1;
 176
 177         /* Also verify that the cache does not have path and path/file
 178          * at the same time.  At this point we know the cache has only
 179          * stage 0 entries.
 180          */
 181         funny = 0;
 182         for (i = 0; i < entries - 1; i++) {
 183                 /* path/file always comes after path because of the way
 184                  * the cache is sorted.  Also path can appear only once,
 185                  * which means conflicting one would immediately follow.
 186                  */
 187                 const char *this_name = cache[i]->name;
 188                 const char *next_name = cache[i+1]->name;
 189                 int this_len = strlen(this_name);
 190                 if (this_len < strlen(next_name) &&
 191                     strncmp(this_name, next_name, this_len) == 0 &&
 192                     next_name[this_len] == '/') {
 193                         if (10 < ++funny) {
 194                                 fprintf(stderr, "...\n");
 195                                 break;
 196                         }
 197                         fprintf(stderr, "You have both %s and %s\n",
 198                                 this_name, next_name);
 199                 }
 200         }
 201         if (funny)
 202                 return -1;
 203         return 0;
 204 }
 205
 206 static void discard_unused_subtrees(struct cache_tree *it)
 207 {
 208         struct cache_tree_sub **down = it->down;
 209         int nr = it->subtree_nr;
 210         int dst, src;
 211         for (dst = src = 0; src < nr; src++) {
 212                 struct cache_tree_sub *s = down[src];
 213                 if (s->used)
 214                         down[dst++] = s;
 215                 else {
 216                         cache_tree_free(&s->cache_tree);
 217                         free(s);
 218                         it->subtree_nr--;
 219                 }
 220         }
 221 }
 222
 223 int cache_tree_fully_valid(struct cache_tree *it)
 224 {
 225         int i;
 226         if (!it)
 227                 return 0;
 228         if (it->entry_count < 0 || !has_sha1_file(it->oid.hash))
 229                 return 0;
 230         for (i = 0; i < it->subtree_nr; i++) {
 231                 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
 232                         return 0;
 233         }
 234         return 1;
 235 }
 236
 237 static int update_one(struct cache_tree *it,
 238                       struct cache_entry **cache,
 239                       int entries,
 240                       const char *base,
 241                       int baselen,
 242                       int *skip_count,
 243                       int flags)
 244 {
 245         struct strbuf buffer;
 246         int missing_ok = flags & WRITE_TREE_MISSING_OK;
 247         int dryrun = flags & WRITE_TREE_DRY_RUN;
 248         int repair = flags & WRITE_TREE_REPAIR;
 249         int to_invalidate = 0;
 250         int i;
 251
 252         assert(!(dryrun && repair));
 253
 254         *skip_count = 0;
 255
 256         if (0 <= it->entry_count && has_sha1_file(it->oid.hash))
 257                 return it->entry_count;
 258
 259         /*
 260          * We first scan for subtrees and update them; we start by
 261          * marking existing subtrees -- the ones that are unmarked
 262          * should not be in the result.
 263          */
 264         for (i = 0; i < it->subtree_nr; i++)
 265                 it->down[i]->used = 0;
 266
 267         /*
 268          * Find the subtrees and update them.
 269          */
 270         i = 0;
 271         while (i < entries) {
 272                 const struct cache_entry *ce = cache[i];
 273                 struct cache_tree_sub *sub;
 274                 const char *path, *slash;
 275                 int pathlen, sublen, subcnt, subskip;
 276
 277                 path = ce->name;
 278                 pathlen = ce_namelen(ce);
 279                 if (pathlen <= baselen || memcmp(base, path, baselen))
 280                         break; /* at the end of this level */
 281
 282                 slash = strchr(path + baselen, '/');
 283                 if (!slash) {
 284                         i++;
 285                         continue;
 286                 }
 287                 /*
 288                  * a/bbb/c (base = a/, slash = /c)
 289                  * ==>
 290                  * path+baselen = bbb/c, sublen = 3
 291                  */
 292                 sublen = slash - (path + baselen);
 293                 sub = find_subtree(it, path + baselen, sublen, 1);
 294                 if (!sub->cache_tree)
 295                         sub->cache_tree = cache_tree();
 296                 subcnt = update_one(sub->cache_tree,
 297                                     cache + i, entries - i,
 298                                     path,
 299                                     baselen + sublen + 1,
 300                                     &subskip,
 301                                     flags);
 302                 if (subcnt < 0)
 303                         return subcnt;
 304                 if (!subcnt)
 305                         die("index cache-tree records empty sub-tree");
 306                 i += subcnt;
 307                 sub->count = subcnt; /* to be used in the next loop */
 308                 *skip_count += subskip;
 309                 sub->used = 1;
 310         }
 311
 312         discard_unused_subtrees(it);
 313
 314         /*
 315          * Then write out the tree object for this level.
 316          */
 317         strbuf_init(&buffer, 8192);
 318
 319         i = 0;
 320         while (i < entries) {
 321                 const struct cache_entry *ce = cache[i];
 322                 struct cache_tree_sub *sub = NULL;
 323                 const char *path, *slash;
 324                 int pathlen, entlen;
 325                 const struct object_id *oid;
 326                 unsigned mode;
 327                 int expected_missing = 0;
 328                 int contains_ita = 0;
 329
 330                 path = ce->name;
 331                 pathlen = ce_namelen(ce);
 332                 if (pathlen <= baselen || memcmp(base, path, baselen))
 333                         break; /* at the end of this level */
 334
 335                 slash = strchr(path + baselen, '/');
 336                 if (slash) {
 337                         entlen = slash - (path + baselen);
 338                         sub = find_subtree(it, path + baselen, entlen, 0);
 339                         if (!sub)
 340                                 die("cache-tree.c: '%.*s' in '%s' not found",
 341                                     entlen, path + baselen, path);
 342                         i += sub->count;
 343                         oid = &sub->cache_tree->oid;
 344                         mode = S_IFDIR;
 345                         contains_ita = sub->cache_tree->entry_count < 0;
 346                         if (contains_ita) {
 347                                 to_invalidate = 1;
 348                                 expected_missing = 1;
 349                         }
 350                 }
 351                 else {
 352                         oid = &ce->oid;
 353                         mode = ce->ce_mode;
 354                         entlen = pathlen - baselen;
 355                         i++;
 356                 }
 357
 358                 if (is_null_oid(oid) ||
 359                     (mode != S_IFGITLINK && !missing_ok && !has_object_file(oid))) {
 360                         strbuf_release(&buffer);
 361                         if (expected_missing)
 362                                 return -1;
 363                         return error("invalid object %06o %s for '%.*s'",
 364                                 mode, oid_to_hex(oid), entlen+baselen, path);
 365                 }
 366
 367                 /*
 368                  * CE_REMOVE entries are removed before the index is
 369                  * written to disk. Skip them to remain consistent
 370                  * with the future on-disk index.
 371                  */
 372                 if (ce->ce_flags & CE_REMOVE) {
 373                         *skip_count = *skip_count + 1;
 374                         continue;
 375                 }
 376
 377                 /*
 378                  * CE_INTENT_TO_ADD entries exist on on-disk index but
 379                  * they are not part of generated trees. Invalidate up
 380                  * to root to force cache-tree users to read elsewhere.
 381                  */
 382                 if (!sub && ce_intent_to_add(ce)) {
 383                         to_invalidate = 1;
 384                         continue;
 385                 }
 386
 387                 /*
 388                  * "sub" can be an empty tree if all subentries are i-t-a.
 389                  */
 390                 if (contains_ita && is_empty_tree_oid(oid))
 391                         continue;
 392
 393                 strbuf_grow(&buffer, entlen + 100);
 394                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
 395                 strbuf_add(&buffer, oid->hash, the_hash_algo->rawsz);
 396
 397 #if DEBUG
 398                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
 399                         mode, entlen, path + baselen);
 400 #endif
 401         }
 402
 403         if (repair) {
 404                 struct object_id oid;
 405                 hash_object_file(buffer.buf, buffer.len, tree_type, &oid);
 406                 if (has_object_file(&oid))
 407                         oidcpy(&it->oid, &oid);
 408                 else
 409                         to_invalidate = 1;
 410         } else if (dryrun) {
 411                 hash_object_file(buffer.buf, buffer.len, tree_type, &it->oid);
 412         } else if (write_object_file(buffer.buf, buffer.len, tree_type,
 413                                      &it->oid)) {
 414                 strbuf_release(&buffer);
 415                 return -1;
 416         }
 417
 418         strbuf_release(&buffer);
 419         it->entry_count = to_invalidate ? -1 : i - *skip_count;
 420 #if DEBUG
 421         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
 422                 it->entry_count, it->subtree_nr,
 423                 oid_to_hex(&it->oid));
 424 #endif
 425         return i;
 426 }
 427
 428 int cache_tree_update(struct index_state *istate, int flags)
 429 {
 430         struct cache_tree *it = istate->cache_tree;
 431         struct cache_entry **cache = istate->cache;
 432         int entries = istate->cache_nr;
 433         int skip, i = verify_cache(cache, entries, flags);
 434
 435         if (i)
 436                 return i;
 437         trace_performance_enter();
 438         i = update_one(it, cache, entries, "", 0, &skip, flags);
 439         trace_performance_leave("cache_tree_update");
 440         if (i < 0)
 441                 return i;
 442         istate->cache_changed |= CACHE_TREE_CHANGED;
 443         return 0;
 444 }
 445
 446 static void write_one(struct strbuf *buffer, struct cache_tree *it,
 447                       const char *path, int pathlen)
 448 {
 449         int i;
 450
 451         /* One "cache-tree" entry consists of the following:
 452          * path (NUL terminated)
 453          * entry_count, subtree_nr ("%d %d\n")
 454          * tree-sha1 (missing if invalid)
 455          * subtree_nr "cache-tree" entries for subtrees.
 456          */
 457         strbuf_grow(buffer, pathlen + 100);
 458         strbuf_add(buffer, path, pathlen);
 459         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 460
 461 #if DEBUG
 462         if (0 <= it->entry_count)
 463                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 464                         pathlen, path, it->entry_count, it->subtree_nr,
 465                         oid_to_hex(&it->oid));
 466         else
 467                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 468                         pathlen, path, it->subtree_nr);
 469 #endif
 470
 471         if (0 <= it->entry_count) {
 472                 strbuf_add(buffer, it->oid.hash, the_hash_algo->rawsz);
 473         }
 474         for (i = 0; i < it->subtree_nr; i++) {
 475                 struct cache_tree_sub *down = it->down[i];
 476                 if (i) {
 477                         struct cache_tree_sub *prev = it->down[i-1];
 478                         if (subtree_name_cmp(down->name, down->namelen,
 479                                              prev->name, prev->namelen) <= 0)
 480                                 die("fatal - unsorted cache subtree");
 481                 }
 482                 write_one(buffer, down->cache_tree, down->name, down->namelen);
 483         }
 484 }
 485
 486 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
 487 {
 488         write_one(sb, root, "", 0);
 489 }
 490
 491 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 492 {
 493         const char *buf = *buffer;
 494         unsigned long size = *size_p;
 495         const char *cp;
 496         char *ep;
 497         struct cache_tree *it;
 498         int i, subtree_nr;
 499         const unsigned rawsz = the_hash_algo->rawsz;
 500
 501         it = NULL;
 502         /* skip name, but make sure name exists */
 503         while (size && *buf) {
 504                 size--;
 505                 buf++;
 506         }
 507         if (!size)
 508                 goto free_return;
 509         buf++; size--;
 510         it = cache_tree();
 511
 512         cp = buf;
 513         it->entry_count = strtol(cp, &ep, 10);
 514         if (cp == ep)
 515                 goto free_return;
 516         cp = ep;
 517         subtree_nr = strtol(cp, &ep, 10);
 518         if (cp == ep)
 519                 goto free_return;
 520         while (size && *buf && *buf != '\n') {
 521                 size--;
 522                 buf++;
 523         }
 524         if (!size)
 525                 goto free_return;
 526         buf++; size--;
 527         if (0 <= it->entry_count) {
 528                 if (size < rawsz)
 529                         goto free_return;
 530                 oidread(&it->oid, (const unsigned char *)buf);
 531                 buf += rawsz;
 532                 size -= rawsz;
 533         }
 534
 535 #if DEBUG
 536         if (0 <= it->entry_count)
 537                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 538                         *buffer, it->entry_count, subtree_nr,
 539                         oid_to_hex(&it->oid));
 540         else
 541                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 542                         *buffer, subtree_nr);
 543 #endif
 544
 545         /*
 546          * Just a heuristic -- we do not add directories that often but
 547          * we do not want to have to extend it immediately when we do,
 548          * hence +2.
 549          */
 550         it->subtree_alloc = subtree_nr + 2;
 551         it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
 552         for (i = 0; i < subtree_nr; i++) {
 553                 /* read each subtree */
 554                 struct cache_tree *sub;
 555                 struct cache_tree_sub *subtree;
 556                 const char *name = buf;
 557
 558                 sub = read_one(&buf, &size);
 559                 if (!sub)
 560                         goto free_return;
 561                 subtree = cache_tree_sub(it, name);
 562                 subtree->cache_tree = sub;
 563         }
 564         if (subtree_nr != it->subtree_nr)
 565                 die("cache-tree: internal error");
 566         *buffer = buf;
 567         *size_p = size;
 568         return it;
 569
 570  free_return:
 571         cache_tree_free(&it);
 572         return NULL;
 573 }
 574
 575 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 576 {
 577         if (buffer[0])
 578                 return NULL; /* not the whole tree */
 579         return read_one(&buffer, &size);
 580 }
 581
 582 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 583 {
 584         if (!it)
 585                 return NULL;
 586         while (*path) {
 587                 const char *slash;
 588                 struct cache_tree_sub *sub;
 589
 590                 slash = strchrnul(path, '/');
 591                 /*
 592                  * Between path and slash is the name of the subtree
 593                  * to look for.
 594                  */
 595                 sub = find_subtree(it, path, slash - path, 0);
 596                 if (!sub)
 597                         return NULL;
 598                 it = sub->cache_tree;
 599
 600                 path = slash;
 601                 while (*path == '/')
 602                         path++;
 603         }
 604         return it;
 605 }
 606
 607 int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix)
 608 {
 609         int entries, was_valid;
 610         struct lock_file lock_file = LOCK_INIT;
 611         int ret = 0;
 612
 613         hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
 614
 615         entries = read_index_from(index_state, index_path, get_git_dir());
 616         if (entries < 0) {
 617                 ret = WRITE_TREE_UNREADABLE_INDEX;
 618                 goto out;
 619         }
 620         if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
 621                 cache_tree_free(&index_state->cache_tree);
 622
 623         if (!index_state->cache_tree)
 624                 index_state->cache_tree = cache_tree();
 625
 626         was_valid = cache_tree_fully_valid(index_state->cache_tree);
 627         if (!was_valid) {
 628                 if (cache_tree_update(index_state, flags) < 0) {
 629                         ret = WRITE_TREE_UNMERGED_INDEX;
 630                         goto out;
 631                 }
 632                 write_locked_index(index_state, &lock_file, COMMIT_LOCK);
 633                 /* Not being able to write is fine -- we are only interested
 634                  * in updating the cache-tree part, and if the next caller
 635                  * ends up using the old index with unupdated cache-tree part
 636                  * it misses the work we did here, but that is just a
 637                  * performance penalty and not a big deal.
 638                  */
 639         }
 640
 641         if (prefix) {
 642                 struct cache_tree *subtree;
 643                 subtree = cache_tree_find(index_state->cache_tree, prefix);
 644                 if (!subtree) {
 645                         ret = WRITE_TREE_PREFIX_ERROR;
 646                         goto out;
 647                 }
 648                 oidcpy(oid, &subtree->oid);
 649         }
 650         else
 651                 oidcpy(oid, &index_state->cache_tree->oid);
 652
 653 out:
 654         rollback_lock_file(&lock_file);
 655         return ret;
 656 }
 657
 658 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
 659 {
 660         struct tree_desc desc;
 661         struct name_entry entry;
 662         int cnt;
 663
 664         oidcpy(&it->oid, &tree->object.oid);
 665         init_tree_desc(&desc, tree->buffer, tree->size);
 666         cnt = 0;
 667         while (tree_entry(&desc, &entry)) {
 668                 if (!S_ISDIR(entry.mode))
 669                         cnt++;
 670                 else {
 671                         struct cache_tree_sub *sub;
 672                         struct tree *subtree = lookup_tree(the_repository,
 673                                                            entry.oid);
 674                         if (!subtree->object.parsed)
 675                                 parse_tree(subtree);
 676                         sub = cache_tree_sub(it, entry.path);
 677                         sub->cache_tree = cache_tree();
 678                         prime_cache_tree_rec(sub->cache_tree, subtree);
 679                         cnt += sub->cache_tree->entry_count;
 680                 }
 681         }
 682         it->entry_count = cnt;
 683 }
 684
 685 void prime_cache_tree(struct index_state *istate, struct tree *tree)
 686 {
 687         cache_tree_free(&istate->cache_tree);
 688         istate->cache_tree = cache_tree();
 689         prime_cache_tree_rec(istate->cache_tree, tree);
 690         istate->cache_changed |= CACHE_TREE_CHANGED;
 691 }
 692
 693 /*
 694  * find the cache_tree that corresponds to the current level without
 695  * exploding the full path into textual form.  The root of the
 696  * cache tree is given as "root", and our current level is "info".
 697  * (1) When at root level, info->prev is NULL, so it is "root" itself.
 698  * (2) Otherwise, find the cache_tree that corresponds to one level
 699  *     above us, and find ourselves in there.
 700  */
 701 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
 702                                                          struct traverse_info *info)
 703 {
 704         struct cache_tree *our_parent;
 705
 706         if (!info->prev)
 707                 return root;
 708         our_parent = find_cache_tree_from_traversal(root, info->prev);
 709         return cache_tree_find(our_parent, info->name.path);
 710 }
 711
 712 int cache_tree_matches_traversal(struct cache_tree *root,
 713                                  struct name_entry *ent,
 714                                  struct traverse_info *info)
 715 {
 716         struct cache_tree *it;
 717
 718         it = find_cache_tree_from_traversal(root, info);
 719         it = cache_tree_find(it, ent->path);
 720         if (it && it->entry_count > 0 && oideq(ent->oid, &it->oid))
 721                 return it->entry_count;
 722         return 0;
 723 }
 724
 725 static void verify_one(struct index_state *istate,
 726                        struct cache_tree *it,
 727                        struct strbuf *path)
 728 {
 729         int i, pos, len = path->len;
 730         struct strbuf tree_buf = STRBUF_INIT;
 731         struct object_id new_oid;
 732
 733         for (i = 0; i < it->subtree_nr; i++) {
 734                 strbuf_addf(path, "%s/", it->down[i]->name);
 735                 verify_one(istate, it->down[i]->cache_tree, path);
 736                 strbuf_setlen(path, len);
 737         }
 738
 739         if (it->entry_count < 0 ||
 740             /* no verification on tests (t7003) that replace trees */
 741             lookup_replace_object(the_repository, &it->oid) != &it->oid)
 742                 return;
 743
 744         if (path->len) {
 745                 pos = index_name_pos(istate, path->buf, path->len);
 746                 pos = -pos - 1;
 747         } else {
 748                 pos = 0;
 749         }
 750
 751         i = 0;
 752         while (i < it->entry_count) {
 753                 struct cache_entry *ce = istate->cache[pos + i];
 754                 const char *slash;
 755                 struct cache_tree_sub *sub = NULL;
 756                 const struct object_id *oid;
 757                 const char *name;
 758                 unsigned mode;
 759                 int entlen;
 760
 761                 if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE))
 762                         BUG("%s with flags 0x%x should not be in cache-tree",
 763                             ce->name, ce->ce_flags);
 764                 name = ce->name + path->len;
 765                 slash = strchr(name, '/');
 766                 if (slash) {
 767                         entlen = slash - name;
 768                         sub = find_subtree(it, ce->name + path->len, entlen, 0);
 769                         if (!sub || sub->cache_tree->entry_count < 0)
 770                                 BUG("bad subtree '%.*s'", entlen, name);
 771                         oid = &sub->cache_tree->oid;
 772                         mode = S_IFDIR;
 773                         i += sub->cache_tree->entry_count;
 774                 } else {
 775                         oid = &ce->oid;
 776                         mode = ce->ce_mode;
 777                         entlen = ce_namelen(ce) - path->len;
 778                         i++;
 779                 }
 780                 strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0');
 781                 strbuf_add(&tree_buf, oid->hash, the_hash_algo->rawsz);
 782         }
 783         hash_object_file(tree_buf.buf, tree_buf.len, tree_type, &new_oid);
 784         if (oidcmp(&new_oid, &it->oid))
 785                 BUG("cache-tree for path %.*s does not match. "
 786                     "Expected %s got %s", len, path->buf,
 787                     oid_to_hex(&new_oid), oid_to_hex(&it->oid));
 788         strbuf_setlen(path, len);
 789         strbuf_release(&tree_buf);
 790 }
 791
 792 void cache_tree_verify(struct index_state *istate)
 793 {
 794         struct strbuf path = STRBUF_INIT;
 795
 796         if (!istate->cache_tree)
 797                 return;
 798         verify_one(istate, istate->cache_tree, &path);
 799         strbuf_release(&path);
 800 }