git.oblomov.eu Git - git/blob - 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 #include "promisor-remote.h"
   9
  10 #ifndef DEBUG_CACHE_TREE
  11 #define DEBUG_CACHE_TREE 0
  12 #endif
  13
  14 struct cache_tree *cache_tree(void)
  15 {
  16         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  17         it->entry_count = -1;
  18         return it;
  19 }
  20
  21 void cache_tree_free(struct cache_tree **it_p)
  22 {
  23         int i;
  24         struct cache_tree *it = *it_p;
  25
  26         if (!it)
  27                 return;
  28         for (i = 0; i < it->subtree_nr; i++)
  29                 if (it->down[i]) {
  30                         cache_tree_free(&it->down[i]->cache_tree);
  31                         free(it->down[i]);
  32                 }
  33         free(it->down);
  34         free(it);
  35         *it_p = NULL;
  36 }
  37
  38 static int subtree_name_cmp(const char *one, int onelen,
  39                             const char *two, int twolen)
  40 {
  41         if (onelen < twolen)
  42                 return -1;
  43         if (twolen < onelen)
  44                 return 1;
  45         return memcmp(one, two, onelen);
  46 }
  47
  48 static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  49 {
  50         struct cache_tree_sub **down = it->down;
  51         int lo, hi;
  52         lo = 0;
  53         hi = it->subtree_nr;
  54         while (lo < hi) {
  55                 int mi = lo + (hi - lo) / 2;
  56                 struct cache_tree_sub *mdl = down[mi];
  57                 int cmp = subtree_name_cmp(path, pathlen,
  58                                            mdl->name, mdl->namelen);
  59                 if (!cmp)
  60                         return mi;
  61                 if (cmp < 0)
  62                         hi = mi;
  63                 else
  64                         lo = mi + 1;
  65         }
  66         return -lo-1;
  67 }
  68
  69 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  70                                            const char *path,
  71                                            int pathlen,
  72                                            int create)
  73 {
  74         struct cache_tree_sub *down;
  75         int pos = subtree_pos(it, path, pathlen);
  76         if (0 <= pos)
  77                 return it->down[pos];
  78         if (!create)
  79                 return NULL;
  80
  81         pos = -pos-1;
  82         ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
  83         it->subtree_nr++;
  84
  85         FLEX_ALLOC_MEM(down, name, path, pathlen);
  86         down->cache_tree = NULL;
  87         down->namelen = pathlen;
  88
  89         if (pos < it->subtree_nr)
  90                 MOVE_ARRAY(it->down + pos + 1, it->down + pos,
  91                            it->subtree_nr - pos - 1);
  92         it->down[pos] = down;
  93         return down;
  94 }
  95
  96 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
  97 {
  98         int pathlen = strlen(path);
  99         return find_subtree(it, path, pathlen, 1);
 100 }
 101
 102 static int do_invalidate_path(struct cache_tree *it, const char *path)
 103 {
 104         /* a/b/c
 105          * ==> invalidate self
 106          * ==> find "a", have it invalidate "b/c"
 107          * a
 108          * ==> invalidate self
 109          * ==> if "a" exists as a subtree, remove it.
 110          */
 111         const char *slash;
 112         int namelen;
 113         struct cache_tree_sub *down;
 114
 115 #if DEBUG_CACHE_TREE
 116         fprintf(stderr, "cache-tree invalidate <%s>\n", path);
 117 #endif
 118
 119         if (!it)
 120                 return 0;
 121         slash = strchrnul(path, '/');
 122         namelen = slash - path;
 123         it->entry_count = -1;
 124         if (!*slash) {
 125                 int pos;
 126                 pos = subtree_pos(it, path, namelen);
 127                 if (0 <= pos) {
 128                         cache_tree_free(&it->down[pos]->cache_tree);
 129                         free(it->down[pos]);
 130                         /* 0 1 2 3 4 5
 131                          *       ^     ^subtree_nr = 6
 132                          *       pos
 133                          * move 4 and 5 up one place (2 entries)
 134                          * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 135                          */
 136                         MOVE_ARRAY(it->down + pos, it->down + pos + 1,
 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, oid_to_hex(&ce->oid));
 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_object_file(&it->oid))
 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_object_file(&it->oid))
 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                 if (!subcnt)
 306                         die("index cache-tree records empty sub-tree");
 307                 i += subcnt;
 308                 sub->count = subcnt; /* to be used in the next loop */
 309                 *skip_count += subskip;
 310                 sub->used = 1;
 311         }
 312
 313         discard_unused_subtrees(it);
 314
 315         /*
 316          * Then write out the tree object for this level.
 317          */
 318         strbuf_init(&buffer, 8192);
 319
 320         i = 0;
 321         while (i < entries) {
 322                 const struct cache_entry *ce = cache[i];
 323                 struct cache_tree_sub *sub = NULL;
 324                 const char *path, *slash;
 325                 int pathlen, entlen;
 326                 const struct object_id *oid;
 327                 unsigned mode;
 328                 int expected_missing = 0;
 329                 int contains_ita = 0;
 330                 int ce_missing_ok;
 331
 332                 path = ce->name;
 333                 pathlen = ce_namelen(ce);
 334                 if (pathlen <= baselen || memcmp(base, path, baselen))
 335                         break; /* at the end of this level */
 336
 337                 slash = strchr(path + baselen, '/');
 338                 if (slash) {
 339                         entlen = slash - (path + baselen);
 340                         sub = find_subtree(it, path + baselen, entlen, 0);
 341                         if (!sub)
 342                                 die("cache-tree.c: '%.*s' in '%s' not found",
 343                                     entlen, path + baselen, path);
 344                         i += sub->count;
 345                         oid = &sub->cache_tree->oid;
 346                         mode = S_IFDIR;
 347                         contains_ita = sub->cache_tree->entry_count < 0;
 348                         if (contains_ita) {
 349                                 to_invalidate = 1;
 350                                 expected_missing = 1;
 351                         }
 352                 }
 353                 else {
 354                         oid = &ce->oid;
 355                         mode = ce->ce_mode;
 356                         entlen = pathlen - baselen;
 357                         i++;
 358                 }
 359
 360                 ce_missing_ok = mode == S_IFGITLINK || missing_ok ||
 361                         (has_promisor_remote() &&
 362                          ce_skip_worktree(ce));
 363                 if (is_null_oid(oid) ||
 364                     (!ce_missing_ok && !has_object_file(oid))) {
 365                         strbuf_release(&buffer);
 366                         if (expected_missing)
 367                                 return -1;
 368                         return error("invalid object %06o %s for '%.*s'",
 369                                 mode, oid_to_hex(oid), entlen+baselen, path);
 370                 }
 371
 372                 /*
 373                  * CE_REMOVE entries are removed before the index is
 374                  * written to disk. Skip them to remain consistent
 375                  * with the future on-disk index.
 376                  */
 377                 if (ce->ce_flags & CE_REMOVE) {
 378                         *skip_count = *skip_count + 1;
 379                         continue;
 380                 }
 381
 382                 /*
 383                  * CE_INTENT_TO_ADD entries exist on on-disk index but
 384                  * they are not part of generated trees. Invalidate up
 385                  * to root to force cache-tree users to read elsewhere.
 386                  */
 387                 if (!sub && ce_intent_to_add(ce)) {
 388                         to_invalidate = 1;
 389                         continue;
 390                 }
 391
 392                 /*
 393                  * "sub" can be an empty tree if all subentries are i-t-a.
 394                  */
 395                 if (contains_ita && is_empty_tree_oid(oid))
 396                         continue;
 397
 398                 strbuf_grow(&buffer, entlen + 100);
 399                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
 400                 strbuf_add(&buffer, oid->hash, the_hash_algo->rawsz);
 401
 402 #if DEBUG_CACHE_TREE
 403                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
 404                         mode, entlen, path + baselen);
 405 #endif
 406         }
 407
 408         if (repair) {
 409                 struct object_id oid;
 410                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 411                                  tree_type, &oid);
 412                 if (has_object_file_with_flags(&oid, OBJECT_INFO_SKIP_FETCH_OBJECT))
 413                         oidcpy(&it->oid, &oid);
 414                 else
 415                         to_invalidate = 1;
 416         } else if (dryrun) {
 417                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 418                                  tree_type, &it->oid);
 419         } else if (write_object_file(buffer.buf, buffer.len, tree_type,
 420                                      &it->oid)) {
 421                 strbuf_release(&buffer);
 422                 return -1;
 423         }
 424
 425         strbuf_release(&buffer);
 426         it->entry_count = to_invalidate ? -1 : i - *skip_count;
 427 #if DEBUG_CACHE_TREE
 428         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
 429                 it->entry_count, it->subtree_nr,
 430                 oid_to_hex(&it->oid));
 431 #endif
 432         return i;
 433 }
 434
 435 int cache_tree_update(struct index_state *istate, int flags)
 436 {
 437         struct cache_tree *it = istate->cache_tree;
 438         struct cache_entry **cache = istate->cache;
 439         int entries = istate->cache_nr;
 440         int skip, i = verify_cache(cache, entries, flags);
 441
 442         if (i)
 443                 return i;
 444         trace_performance_enter();
 445         i = update_one(it, cache, entries, "", 0, &skip, flags);
 446         trace_performance_leave("cache_tree_update");
 447         if (i < 0)
 448                 return i;
 449         istate->cache_changed |= CACHE_TREE_CHANGED;
 450         return 0;
 451 }
 452
 453 static void write_one(struct strbuf *buffer, struct cache_tree *it,
 454                       const char *path, int pathlen)
 455 {
 456         int i;
 457
 458         /* One "cache-tree" entry consists of the following:
 459          * path (NUL terminated)
 460          * entry_count, subtree_nr ("%d %d\n")
 461          * tree-sha1 (missing if invalid)
 462          * subtree_nr "cache-tree" entries for subtrees.
 463          */
 464         strbuf_grow(buffer, pathlen + 100);
 465         strbuf_add(buffer, path, pathlen);
 466         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 467
 468 #if DEBUG_CACHE_TREE
 469         if (0 <= it->entry_count)
 470                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 471                         pathlen, path, it->entry_count, it->subtree_nr,
 472                         oid_to_hex(&it->oid));
 473         else
 474                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 475                         pathlen, path, it->subtree_nr);
 476 #endif
 477
 478         if (0 <= it->entry_count) {
 479                 strbuf_add(buffer, it->oid.hash, the_hash_algo->rawsz);
 480         }
 481         for (i = 0; i < it->subtree_nr; i++) {
 482                 struct cache_tree_sub *down = it->down[i];
 483                 if (i) {
 484                         struct cache_tree_sub *prev = it->down[i-1];
 485                         if (subtree_name_cmp(down->name, down->namelen,
 486                                              prev->name, prev->namelen) <= 0)
 487                                 die("fatal - unsorted cache subtree");
 488                 }
 489                 write_one(buffer, down->cache_tree, down->name, down->namelen);
 490         }
 491 }
 492
 493 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
 494 {
 495         write_one(sb, root, "", 0);
 496 }
 497
 498 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 499 {
 500         const char *buf = *buffer;
 501         unsigned long size = *size_p;
 502         const char *cp;
 503         char *ep;
 504         struct cache_tree *it;
 505         int i, subtree_nr;
 506         const unsigned rawsz = the_hash_algo->rawsz;
 507
 508         it = NULL;
 509         /* skip name, but make sure name exists */
 510         while (size && *buf) {
 511                 size--;
 512                 buf++;
 513         }
 514         if (!size)
 515                 goto free_return;
 516         buf++; size--;
 517         it = cache_tree();
 518
 519         cp = buf;
 520         it->entry_count = strtol(cp, &ep, 10);
 521         if (cp == ep)
 522                 goto free_return;
 523         cp = ep;
 524         subtree_nr = strtol(cp, &ep, 10);
 525         if (cp == ep)
 526                 goto free_return;
 527         while (size && *buf && *buf != '\n') {
 528                 size--;
 529                 buf++;
 530         }
 531         if (!size)
 532                 goto free_return;
 533         buf++; size--;
 534         if (0 <= it->entry_count) {
 535                 if (size < rawsz)
 536                         goto free_return;
 537                 oidread(&it->oid, (const unsigned char *)buf);
 538                 buf += rawsz;
 539                 size -= rawsz;
 540         }
 541
 542 #if DEBUG_CACHE_TREE
 543         if (0 <= it->entry_count)
 544                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 545                         *buffer, it->entry_count, subtree_nr,
 546                         oid_to_hex(&it->oid));
 547         else
 548                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 549                         *buffer, subtree_nr);
 550 #endif
 551
 552         /*
 553          * Just a heuristic -- we do not add directories that often but
 554          * we do not want to have to extend it immediately when we do,
 555          * hence +2.
 556          */
 557         it->subtree_alloc = subtree_nr + 2;
 558         it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
 559         for (i = 0; i < subtree_nr; i++) {
 560                 /* read each subtree */
 561                 struct cache_tree *sub;
 562                 struct cache_tree_sub *subtree;
 563                 const char *name = buf;
 564
 565                 sub = read_one(&buf, &size);
 566                 if (!sub)
 567                         goto free_return;
 568                 subtree = cache_tree_sub(it, name);
 569                 subtree->cache_tree = sub;
 570         }
 571         if (subtree_nr != it->subtree_nr)
 572                 die("cache-tree: internal error");
 573         *buffer = buf;
 574         *size_p = size;
 575         return it;
 576
 577  free_return:
 578         cache_tree_free(&it);
 579         return NULL;
 580 }
 581
 582 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 583 {
 584         if (buffer[0])
 585                 return NULL; /* not the whole tree */
 586         return read_one(&buffer, &size);
 587 }
 588
 589 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 590 {
 591         if (!it)
 592                 return NULL;
 593         while (*path) {
 594                 const char *slash;
 595                 struct cache_tree_sub *sub;
 596
 597                 slash = strchrnul(path, '/');
 598                 /*
 599                  * Between path and slash is the name of the subtree
 600                  * to look for.
 601                  */
 602                 sub = find_subtree(it, path, slash - path, 0);
 603                 if (!sub)
 604                         return NULL;
 605                 it = sub->cache_tree;
 606
 607                 path = slash;
 608                 while (*path == '/')
 609                         path++;
 610         }
 611         return it;
 612 }
 613
 614 static int write_index_as_tree_internal(struct object_id *oid,
 615                                         struct index_state *index_state,
 616                                         int cache_tree_valid,
 617                                         int flags,
 618                                         const char *prefix)
 619 {
 620         if (flags & WRITE_TREE_IGNORE_CACHE_TREE) {
 621                 cache_tree_free(&index_state->cache_tree);
 622                 cache_tree_valid = 0;
 623         }
 624
 625         if (!index_state->cache_tree)
 626                 index_state->cache_tree = cache_tree();
 627
 628         if (!cache_tree_valid && cache_tree_update(index_state, flags) < 0)
 629                 return WRITE_TREE_UNMERGED_INDEX;
 630
 631         if (prefix) {
 632                 struct cache_tree *subtree;
 633                 subtree = cache_tree_find(index_state->cache_tree, prefix);
 634                 if (!subtree)
 635                         return WRITE_TREE_PREFIX_ERROR;
 636                 oidcpy(oid, &subtree->oid);
 637         }
 638         else
 639                 oidcpy(oid, &index_state->cache_tree->oid);
 640
 641         return 0;
 642 }
 643
 644 struct tree* write_in_core_index_as_tree(struct repository *repo) {
 645         struct object_id o;
 646         int was_valid, ret;
 647
 648         struct index_state *index_state = repo->index;
 649         was_valid = index_state->cache_tree &&
 650                     cache_tree_fully_valid(index_state->cache_tree);
 651
 652         ret = write_index_as_tree_internal(&o, index_state, was_valid, 0, NULL);
 653         if (ret == WRITE_TREE_UNMERGED_INDEX) {
 654                 int i;
 655                 fprintf(stderr, "BUG: There are unmerged index entries:\n");
 656                 for (i = 0; i < index_state->cache_nr; i++) {
 657                         const struct cache_entry *ce = index_state->cache[i];
 658                         if (ce_stage(ce))
 659                                 fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
 660                                         (int)ce_namelen(ce), ce->name);
 661                 }
 662                 BUG("unmerged index entries when writing inmemory index");
 663         }
 664
 665         return lookup_tree(repo, &index_state->cache_tree->oid);
 666 }
 667
 668
 669 int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix)
 670 {
 671         int entries, was_valid;
 672         struct lock_file lock_file = LOCK_INIT;
 673         int ret;
 674
 675         hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
 676
 677         entries = read_index_from(index_state, index_path, get_git_dir());
 678         if (entries < 0) {
 679                 ret = WRITE_TREE_UNREADABLE_INDEX;
 680                 goto out;
 681         }
 682
 683         was_valid = !(flags & WRITE_TREE_IGNORE_CACHE_TREE) &&
 684                     index_state->cache_tree &&
 685                     cache_tree_fully_valid(index_state->cache_tree);
 686
 687         ret = write_index_as_tree_internal(oid, index_state, was_valid, flags,
 688                                            prefix);
 689         if (!ret && !was_valid) {
 690                 write_locked_index(index_state, &lock_file, COMMIT_LOCK);
 691                 /* Not being able to write is fine -- we are only interested
 692                  * in updating the cache-tree part, and if the next caller
 693                  * ends up using the old index with unupdated cache-tree part
 694                  * it misses the work we did here, but that is just a
 695                  * performance penalty and not a big deal.
 696                  */
 697         }
 698
 699 out:
 700         rollback_lock_file(&lock_file);
 701         return ret;
 702 }
 703
 704 static void prime_cache_tree_rec(struct repository *r,
 705                                  struct cache_tree *it,
 706                                  struct tree *tree)
 707 {
 708         struct tree_desc desc;
 709         struct name_entry entry;
 710         int cnt;
 711
 712         oidcpy(&it->oid, &tree->object.oid);
 713         init_tree_desc(&desc, tree->buffer, tree->size);
 714         cnt = 0;
 715         while (tree_entry(&desc, &entry)) {
 716                 if (!S_ISDIR(entry.mode))
 717                         cnt++;
 718                 else {
 719                         struct cache_tree_sub *sub;
 720                         struct tree *subtree = lookup_tree(r, &entry.oid);
 721                         if (!subtree->object.parsed)
 722                                 parse_tree(subtree);
 723                         sub = cache_tree_sub(it, entry.path);
 724                         sub->cache_tree = cache_tree();
 725                         prime_cache_tree_rec(r, sub->cache_tree, subtree);
 726                         cnt += sub->cache_tree->entry_count;
 727                 }
 728         }
 729         it->entry_count = cnt;
 730 }
 731
 732 void prime_cache_tree(struct repository *r,
 733                       struct index_state *istate,
 734                       struct tree *tree)
 735 {
 736         cache_tree_free(&istate->cache_tree);
 737         istate->cache_tree = cache_tree();
 738         prime_cache_tree_rec(r, istate->cache_tree, tree);
 739         istate->cache_changed |= CACHE_TREE_CHANGED;
 740 }
 741
 742 /*
 743  * find the cache_tree that corresponds to the current level without
 744  * exploding the full path into textual form.  The root of the
 745  * cache tree is given as "root", and our current level is "info".
 746  * (1) When at root level, info->prev is NULL, so it is "root" itself.
 747  * (2) Otherwise, find the cache_tree that corresponds to one level
 748  *     above us, and find ourselves in there.
 749  */
 750 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
 751                                                          struct traverse_info *info)
 752 {
 753         struct cache_tree *our_parent;
 754
 755         if (!info->prev)
 756                 return root;
 757         our_parent = find_cache_tree_from_traversal(root, info->prev);
 758         return cache_tree_find(our_parent, info->name);
 759 }
 760
 761 int cache_tree_matches_traversal(struct cache_tree *root,
 762                                  struct name_entry *ent,
 763                                  struct traverse_info *info)
 764 {
 765         struct cache_tree *it;
 766
 767         it = find_cache_tree_from_traversal(root, info);
 768         it = cache_tree_find(it, ent->path);
 769         if (it && it->entry_count > 0 && oideq(&ent->oid, &it->oid))
 770                 return it->entry_count;
 771         return 0;
 772 }
 773
 774 static void verify_one(struct repository *r,
 775                        struct index_state *istate,
 776                        struct cache_tree *it,
 777                        struct strbuf *path)
 778 {
 779         int i, pos, len = path->len;
 780         struct strbuf tree_buf = STRBUF_INIT;
 781         struct object_id new_oid;
 782
 783         for (i = 0; i < it->subtree_nr; i++) {
 784                 strbuf_addf(path, "%s/", it->down[i]->name);
 785                 verify_one(r, istate, it->down[i]->cache_tree, path);
 786                 strbuf_setlen(path, len);
 787         }
 788
 789         if (it->entry_count < 0 ||
 790             /* no verification on tests (t7003) that replace trees */
 791             lookup_replace_object(r, &it->oid) != &it->oid)
 792                 return;
 793
 794         if (path->len) {
 795                 pos = index_name_pos(istate, path->buf, path->len);
 796                 pos = -pos - 1;
 797         } else {
 798                 pos = 0;
 799         }
 800
 801         i = 0;
 802         while (i < it->entry_count) {
 803                 struct cache_entry *ce = istate->cache[pos + i];
 804                 const char *slash;
 805                 struct cache_tree_sub *sub = NULL;
 806                 const struct object_id *oid;
 807                 const char *name;
 808                 unsigned mode;
 809                 int entlen;
 810
 811                 if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE))
 812                         BUG("%s with flags 0x%x should not be in cache-tree",
 813                             ce->name, ce->ce_flags);
 814                 name = ce->name + path->len;
 815                 slash = strchr(name, '/');
 816                 if (slash) {
 817                         entlen = slash - name;
 818                         sub = find_subtree(it, ce->name + path->len, entlen, 0);
 819                         if (!sub || sub->cache_tree->entry_count < 0)
 820                                 BUG("bad subtree '%.*s'", entlen, name);
 821                         oid = &sub->cache_tree->oid;
 822                         mode = S_IFDIR;
 823                         i += sub->cache_tree->entry_count;
 824                 } else {
 825                         oid = &ce->oid;
 826                         mode = ce->ce_mode;
 827                         entlen = ce_namelen(ce) - path->len;
 828                         i++;
 829                 }
 830                 strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0');
 831                 strbuf_add(&tree_buf, oid->hash, r->hash_algo->rawsz);
 832         }
 833         hash_object_file(r->hash_algo, tree_buf.buf, tree_buf.len, tree_type,
 834                          &new_oid);
 835         if (!oideq(&new_oid, &it->oid))
 836                 BUG("cache-tree for path %.*s does not match. "
 837                     "Expected %s got %s", len, path->buf,
 838                     oid_to_hex(&new_oid), oid_to_hex(&it->oid));
 839         strbuf_setlen(path, len);
 840         strbuf_release(&tree_buf);
 841 }
 842
 843 void cache_tree_verify(struct repository *r, struct index_state *istate)
 844 {
 845         struct strbuf path = STRBUF_INIT;
 846
 847         if (!istate->cache_tree)
 848                 return;
 849         verify_one(r, istate, istate->cache_tree, &path);
 850         strbuf_release(&path);
 851 }