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 #include "sparse-index.h"
  10
  11 #ifndef DEBUG_CACHE_TREE
  12 #define DEBUG_CACHE_TREE 0
  13 #endif
  14
  15 struct cache_tree *cache_tree(void)
  16 {
  17         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  18         it->entry_count = -1;
  19         return it;
  20 }
  21
  22 void cache_tree_free(struct cache_tree **it_p)
  23 {
  24         int i;
  25         struct cache_tree *it = *it_p;
  26
  27         if (!it)
  28                 return;
  29         for (i = 0; i < it->subtree_nr; i++)
  30                 if (it->down[i]) {
  31                         cache_tree_free(&it->down[i]->cache_tree);
  32                         free(it->down[i]);
  33                 }
  34         free(it->down);
  35         free(it);
  36         *it_p = NULL;
  37 }
  38
  39 static int subtree_name_cmp(const char *one, int onelen,
  40                             const char *two, int twolen)
  41 {
  42         if (onelen < twolen)
  43                 return -1;
  44         if (twolen < onelen)
  45                 return 1;
  46         return memcmp(one, two, onelen);
  47 }
  48
  49 int cache_tree_subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  50 {
  51         struct cache_tree_sub **down = it->down;
  52         int lo, hi;
  53         lo = 0;
  54         hi = it->subtree_nr;
  55         while (lo < hi) {
  56                 int mi = lo + (hi - lo) / 2;
  57                 struct cache_tree_sub *mdl = down[mi];
  58                 int cmp = subtree_name_cmp(path, pathlen,
  59                                            mdl->name, mdl->namelen);
  60                 if (!cmp)
  61                         return mi;
  62                 if (cmp < 0)
  63                         hi = mi;
  64                 else
  65                         lo = mi + 1;
  66         }
  67         return -lo-1;
  68 }
  69
  70 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  71                                            const char *path,
  72                                            int pathlen,
  73                                            int create)
  74 {
  75         struct cache_tree_sub *down;
  76         int pos = cache_tree_subtree_pos(it, path, pathlen);
  77         if (0 <= pos)
  78                 return it->down[pos];
  79         if (!create)
  80                 return NULL;
  81
  82         pos = -pos-1;
  83         ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
  84         it->subtree_nr++;
  85
  86         FLEX_ALLOC_MEM(down, name, path, pathlen);
  87         down->cache_tree = NULL;
  88         down->namelen = pathlen;
  89
  90         if (pos < it->subtree_nr)
  91                 MOVE_ARRAY(it->down + pos + 1, it->down + pos,
  92                            it->subtree_nr - pos - 1);
  93         it->down[pos] = down;
  94         return down;
  95 }
  96
  97 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
  98 {
  99         int pathlen = strlen(path);
 100         return find_subtree(it, path, pathlen, 1);
 101 }
 102
 103 static int do_invalidate_path(struct cache_tree *it, const char *path)
 104 {
 105         /* a/b/c
 106          * ==> invalidate self
 107          * ==> find "a", have it invalidate "b/c"
 108          * a
 109          * ==> invalidate self
 110          * ==> if "a" exists as a subtree, remove it.
 111          */
 112         const char *slash;
 113         int namelen;
 114         struct cache_tree_sub *down;
 115
 116 #if DEBUG_CACHE_TREE
 117         fprintf(stderr, "cache-tree invalidate <%s>\n", path);
 118 #endif
 119
 120         if (!it)
 121                 return 0;
 122         slash = strchrnul(path, '/');
 123         namelen = slash - path;
 124         it->entry_count = -1;
 125         if (!*slash) {
 126                 int pos;
 127                 pos = cache_tree_subtree_pos(it, path, namelen);
 128                 if (0 <= pos) {
 129                         cache_tree_free(&it->down[pos]->cache_tree);
 130                         free(it->down[pos]);
 131                         /* 0 1 2 3 4 5
 132                          *       ^     ^subtree_nr = 6
 133                          *       pos
 134                          * move 4 and 5 up one place (2 entries)
 135                          * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 136                          */
 137                         MOVE_ARRAY(it->down + pos, it->down + pos + 1,
 138                                    it->subtree_nr - pos - 1);
 139                         it->subtree_nr--;
 140                 }
 141                 return 1;
 142         }
 143         down = find_subtree(it, path, namelen, 0);
 144         if (down)
 145                 do_invalidate_path(down->cache_tree, slash + 1);
 146         return 1;
 147 }
 148
 149 void cache_tree_invalidate_path(struct index_state *istate, const char *path)
 150 {
 151         if (do_invalidate_path(istate->cache_tree, path))
 152                 istate->cache_changed |= CACHE_TREE_CHANGED;
 153 }
 154
 155 static int verify_cache(struct index_state *istate, int flags)
 156 {
 157         unsigned 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 < istate->cache_nr; i++) {
 163                 const struct cache_entry *ce = istate->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 + 1 < istate->cache_nr; 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 struct cache_entry *this_ce = istate->cache[i];
 189                 const struct cache_entry *next_ce = istate->cache[i + 1];
 190                 const char *this_name = this_ce->name;
 191                 const char *next_name = next_ce->name;
 192                 int this_len = ce_namelen(this_ce);
 193                 if (this_len < ce_namelen(next_ce) &&
 194                     next_name[this_len] == '/' &&
 195                     strncmp(this_name, next_name, this_len) == 0) {
 196                         if (10 < ++funny) {
 197                                 fprintf(stderr, "...\n");
 198                                 break;
 199                         }
 200                         fprintf(stderr, "You have both %s and %s\n",
 201                                 this_name, next_name);
 202                 }
 203         }
 204         if (funny)
 205                 return -1;
 206         return 0;
 207 }
 208
 209 static void discard_unused_subtrees(struct cache_tree *it)
 210 {
 211         struct cache_tree_sub **down = it->down;
 212         int nr = it->subtree_nr;
 213         int dst, src;
 214         for (dst = src = 0; src < nr; src++) {
 215                 struct cache_tree_sub *s = down[src];
 216                 if (s->used)
 217                         down[dst++] = s;
 218                 else {
 219                         cache_tree_free(&s->cache_tree);
 220                         free(s);
 221                         it->subtree_nr--;
 222                 }
 223         }
 224 }
 225
 226 int cache_tree_fully_valid(struct cache_tree *it)
 227 {
 228         int i;
 229         if (!it)
 230                 return 0;
 231         if (it->entry_count < 0 || !has_object_file(&it->oid))
 232                 return 0;
 233         for (i = 0; i < it->subtree_nr; i++) {
 234                 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
 235                         return 0;
 236         }
 237         return 1;
 238 }
 239
 240 static int must_check_existence(const struct cache_entry *ce)
 241 {
 242         return !(has_promisor_remote() && ce_skip_worktree(ce));
 243 }
 244
 245 static int update_one(struct cache_tree *it,
 246                       struct cache_entry **cache,
 247                       int entries,
 248                       const char *base,
 249                       int baselen,
 250                       int *skip_count,
 251                       int flags)
 252 {
 253         struct strbuf buffer;
 254         int missing_ok = flags & WRITE_TREE_MISSING_OK;
 255         int dryrun = flags & WRITE_TREE_DRY_RUN;
 256         int repair = flags & WRITE_TREE_REPAIR;
 257         int to_invalidate = 0;
 258         int i;
 259
 260         assert(!(dryrun && repair));
 261
 262         *skip_count = 0;
 263
 264         /*
 265          * If the first entry of this region is a sparse directory
 266          * entry corresponding exactly to 'base', then this cache_tree
 267          * struct is a "leaf" in the data structure, pointing to the
 268          * tree OID specified in the entry.
 269          */
 270         if (entries > 0) {
 271                 const struct cache_entry *ce = cache[0];
 272
 273                 if (S_ISSPARSEDIR(ce->ce_mode) &&
 274                     ce->ce_namelen == baselen &&
 275                     !strncmp(ce->name, base, baselen)) {
 276                         it->entry_count = 1;
 277                         oidcpy(&it->oid, &ce->oid);
 278                         return 1;
 279                 }
 280         }
 281
 282         if (0 <= it->entry_count && has_object_file(&it->oid))
 283                 return it->entry_count;
 284
 285         /*
 286          * We first scan for subtrees and update them; we start by
 287          * marking existing subtrees -- the ones that are unmarked
 288          * should not be in the result.
 289          */
 290         for (i = 0; i < it->subtree_nr; i++)
 291                 it->down[i]->used = 0;
 292
 293         /*
 294          * Find the subtrees and update them.
 295          */
 296         i = 0;
 297         while (i < entries) {
 298                 const struct cache_entry *ce = cache[i];
 299                 struct cache_tree_sub *sub;
 300                 const char *path, *slash;
 301                 int pathlen, sublen, subcnt, subskip;
 302
 303                 path = ce->name;
 304                 pathlen = ce_namelen(ce);
 305                 if (pathlen <= baselen || memcmp(base, path, baselen))
 306                         break; /* at the end of this level */
 307
 308                 slash = strchr(path + baselen, '/');
 309                 if (!slash) {
 310                         i++;
 311                         continue;
 312                 }
 313                 /*
 314                  * a/bbb/c (base = a/, slash = /c)
 315                  * ==>
 316                  * path+baselen = bbb/c, sublen = 3
 317                  */
 318                 sublen = slash - (path + baselen);
 319                 sub = find_subtree(it, path + baselen, sublen, 1);
 320                 if (!sub->cache_tree)
 321                         sub->cache_tree = cache_tree();
 322                 subcnt = update_one(sub->cache_tree,
 323                                     cache + i, entries - i,
 324                                     path,
 325                                     baselen + sublen + 1,
 326                                     &subskip,
 327                                     flags);
 328                 if (subcnt < 0)
 329                         return subcnt;
 330                 if (!subcnt)
 331                         die("index cache-tree records empty sub-tree");
 332                 i += subcnt;
 333                 sub->count = subcnt; /* to be used in the next loop */
 334                 *skip_count += subskip;
 335                 sub->used = 1;
 336         }
 337
 338         discard_unused_subtrees(it);
 339
 340         /*
 341          * Then write out the tree object for this level.
 342          */
 343         strbuf_init(&buffer, 8192);
 344
 345         i = 0;
 346         while (i < entries) {
 347                 const struct cache_entry *ce = cache[i];
 348                 struct cache_tree_sub *sub = NULL;
 349                 const char *path, *slash;
 350                 int pathlen, entlen;
 351                 const struct object_id *oid;
 352                 unsigned mode;
 353                 int expected_missing = 0;
 354                 int contains_ita = 0;
 355                 int ce_missing_ok;
 356
 357                 path = ce->name;
 358                 pathlen = ce_namelen(ce);
 359                 if (pathlen <= baselen || memcmp(base, path, baselen))
 360                         break; /* at the end of this level */
 361
 362                 slash = strchr(path + baselen, '/');
 363                 if (slash) {
 364                         entlen = slash - (path + baselen);
 365                         sub = find_subtree(it, path + baselen, entlen, 0);
 366                         if (!sub)
 367                                 die("cache-tree.c: '%.*s' in '%s' not found",
 368                                     entlen, path + baselen, path);
 369                         i += sub->count;
 370                         oid = &sub->cache_tree->oid;
 371                         mode = S_IFDIR;
 372                         contains_ita = sub->cache_tree->entry_count < 0;
 373                         if (contains_ita) {
 374                                 to_invalidate = 1;
 375                                 expected_missing = 1;
 376                         }
 377                 }
 378                 else {
 379                         oid = &ce->oid;
 380                         mode = ce->ce_mode;
 381                         entlen = pathlen - baselen;
 382                         i++;
 383                 }
 384
 385                 ce_missing_ok = mode == S_IFGITLINK || missing_ok ||
 386                         !must_check_existence(ce);
 387                 if (is_null_oid(oid) ||
 388                     (!ce_missing_ok && !has_object_file(oid))) {
 389                         strbuf_release(&buffer);
 390                         if (expected_missing)
 391                                 return -1;
 392                         return error("invalid object %06o %s for '%.*s'",
 393                                 mode, oid_to_hex(oid), entlen+baselen, path);
 394                 }
 395
 396                 /*
 397                  * CE_REMOVE entries are removed before the index is
 398                  * written to disk. Skip them to remain consistent
 399                  * with the future on-disk index.
 400                  */
 401                 if (ce->ce_flags & CE_REMOVE) {
 402                         *skip_count = *skip_count + 1;
 403                         continue;
 404                 }
 405
 406                 /*
 407                  * CE_INTENT_TO_ADD entries exist on on-disk index but
 408                  * they are not part of generated trees. Invalidate up
 409                  * to root to force cache-tree users to read elsewhere.
 410                  */
 411                 if (!sub && ce_intent_to_add(ce)) {
 412                         to_invalidate = 1;
 413                         continue;
 414                 }
 415
 416                 /*
 417                  * "sub" can be an empty tree if all subentries are i-t-a.
 418                  */
 419                 if (contains_ita && is_empty_tree_oid(oid))
 420                         continue;
 421
 422                 strbuf_grow(&buffer, entlen + 100);
 423                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
 424                 strbuf_add(&buffer, oid->hash, the_hash_algo->rawsz);
 425
 426 #if DEBUG_CACHE_TREE
 427                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
 428                         mode, entlen, path + baselen);
 429 #endif
 430         }
 431
 432         if (repair) {
 433                 struct object_id oid;
 434                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 435                                  tree_type, &oid);
 436                 if (has_object_file_with_flags(&oid, OBJECT_INFO_SKIP_FETCH_OBJECT))
 437                         oidcpy(&it->oid, &oid);
 438                 else
 439                         to_invalidate = 1;
 440         } else if (dryrun) {
 441                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 442                                  tree_type, &it->oid);
 443         } else if (write_object_file(buffer.buf, buffer.len, tree_type,
 444                                      &it->oid)) {
 445                 strbuf_release(&buffer);
 446                 return -1;
 447         }
 448
 449         strbuf_release(&buffer);
 450         it->entry_count = to_invalidate ? -1 : i - *skip_count;
 451 #if DEBUG_CACHE_TREE
 452         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
 453                 it->entry_count, it->subtree_nr,
 454                 oid_to_hex(&it->oid));
 455 #endif
 456         return i;
 457 }
 458
 459 int cache_tree_update(struct index_state *istate, int flags)
 460 {
 461         int skip, i;
 462
 463         i = verify_cache(istate, flags);
 464
 465         if (i)
 466                 return i;
 467
 468         if (!istate->cache_tree)
 469                 istate->cache_tree = cache_tree();
 470
 471         if (!(flags & WRITE_TREE_MISSING_OK) && has_promisor_remote())
 472                 prefetch_cache_entries(istate, must_check_existence);
 473
 474         trace_performance_enter();
 475         trace2_region_enter("cache_tree", "update", the_repository);
 476         i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
 477                        "", 0, &skip, flags);
 478         trace2_region_leave("cache_tree", "update", the_repository);
 479         trace_performance_leave("cache_tree_update");
 480         if (i < 0)
 481                 return i;
 482         istate->cache_changed |= CACHE_TREE_CHANGED;
 483         return 0;
 484 }
 485
 486 static void write_one(struct strbuf *buffer, struct cache_tree *it,
 487                       const char *path, int pathlen)
 488 {
 489         int i;
 490
 491         /* One "cache-tree" entry consists of the following:
 492          * path (NUL terminated)
 493          * entry_count, subtree_nr ("%d %d\n")
 494          * tree-sha1 (missing if invalid)
 495          * subtree_nr "cache-tree" entries for subtrees.
 496          */
 497         strbuf_grow(buffer, pathlen + 100);
 498         strbuf_add(buffer, path, pathlen);
 499         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 500
 501 #if DEBUG_CACHE_TREE
 502         if (0 <= it->entry_count)
 503                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 504                         pathlen, path, it->entry_count, it->subtree_nr,
 505                         oid_to_hex(&it->oid));
 506         else
 507                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 508                         pathlen, path, it->subtree_nr);
 509 #endif
 510
 511         if (0 <= it->entry_count) {
 512                 strbuf_add(buffer, it->oid.hash, the_hash_algo->rawsz);
 513         }
 514         for (i = 0; i < it->subtree_nr; i++) {
 515                 struct cache_tree_sub *down = it->down[i];
 516                 if (i) {
 517                         struct cache_tree_sub *prev = it->down[i-1];
 518                         if (subtree_name_cmp(down->name, down->namelen,
 519                                              prev->name, prev->namelen) <= 0)
 520                                 die("fatal - unsorted cache subtree");
 521                 }
 522                 write_one(buffer, down->cache_tree, down->name, down->namelen);
 523         }
 524 }
 525
 526 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
 527 {
 528         trace2_region_enter("cache_tree", "write", the_repository);
 529         write_one(sb, root, "", 0);
 530         trace2_region_leave("cache_tree", "write", the_repository);
 531 }
 532
 533 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 534 {
 535         const char *buf = *buffer;
 536         unsigned long size = *size_p;
 537         const char *cp;
 538         char *ep;
 539         struct cache_tree *it;
 540         int i, subtree_nr;
 541         const unsigned rawsz = the_hash_algo->rawsz;
 542
 543         it = NULL;
 544         /* skip name, but make sure name exists */
 545         while (size && *buf) {
 546                 size--;
 547                 buf++;
 548         }
 549         if (!size)
 550                 goto free_return;
 551         buf++; size--;
 552         it = cache_tree();
 553
 554         cp = buf;
 555         it->entry_count = strtol(cp, &ep, 10);
 556         if (cp == ep)
 557                 goto free_return;
 558         cp = ep;
 559         subtree_nr = strtol(cp, &ep, 10);
 560         if (cp == ep)
 561                 goto free_return;
 562         while (size && *buf && *buf != '\n') {
 563                 size--;
 564                 buf++;
 565         }
 566         if (!size)
 567                 goto free_return;
 568         buf++; size--;
 569         if (0 <= it->entry_count) {
 570                 if (size < rawsz)
 571                         goto free_return;
 572                 oidread(&it->oid, (const unsigned char *)buf);
 573                 buf += rawsz;
 574                 size -= rawsz;
 575         }
 576
 577 #if DEBUG_CACHE_TREE
 578         if (0 <= it->entry_count)
 579                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 580                         *buffer, it->entry_count, subtree_nr,
 581                         oid_to_hex(&it->oid));
 582         else
 583                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 584                         *buffer, subtree_nr);
 585 #endif
 586
 587         /*
 588          * Just a heuristic -- we do not add directories that often but
 589          * we do not want to have to extend it immediately when we do,
 590          * hence +2.
 591          */
 592         it->subtree_alloc = subtree_nr + 2;
 593         CALLOC_ARRAY(it->down, it->subtree_alloc);
 594         for (i = 0; i < subtree_nr; i++) {
 595                 /* read each subtree */
 596                 struct cache_tree *sub;
 597                 struct cache_tree_sub *subtree;
 598                 const char *name = buf;
 599
 600                 sub = read_one(&buf, &size);
 601                 if (!sub)
 602                         goto free_return;
 603                 subtree = cache_tree_sub(it, name);
 604                 subtree->cache_tree = sub;
 605         }
 606         if (subtree_nr != it->subtree_nr)
 607                 die("cache-tree: internal error");
 608         *buffer = buf;
 609         *size_p = size;
 610         return it;
 611
 612  free_return:
 613         cache_tree_free(&it);
 614         return NULL;
 615 }
 616
 617 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 618 {
 619         struct cache_tree *result;
 620
 621         if (buffer[0])
 622                 return NULL; /* not the whole tree */
 623
 624         trace2_region_enter("cache_tree", "read", the_repository);
 625         result = read_one(&buffer, &size);
 626         trace2_region_leave("cache_tree", "read", the_repository);
 627
 628         return result;
 629 }
 630
 631 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 632 {
 633         if (!it)
 634                 return NULL;
 635         while (*path) {
 636                 const char *slash;
 637                 struct cache_tree_sub *sub;
 638
 639                 slash = strchrnul(path, '/');
 640                 /*
 641                  * Between path and slash is the name of the subtree
 642                  * to look for.
 643                  */
 644                 sub = find_subtree(it, path, slash - path, 0);
 645                 if (!sub)
 646                         return NULL;
 647                 it = sub->cache_tree;
 648
 649                 path = slash;
 650                 while (*path == '/')
 651                         path++;
 652         }
 653         return it;
 654 }
 655
 656 static int write_index_as_tree_internal(struct object_id *oid,
 657                                         struct index_state *index_state,
 658                                         int cache_tree_valid,
 659                                         int flags,
 660                                         const char *prefix)
 661 {
 662         if (flags & WRITE_TREE_IGNORE_CACHE_TREE) {
 663                 cache_tree_free(&index_state->cache_tree);
 664                 cache_tree_valid = 0;
 665         }
 666
 667         if (!cache_tree_valid && cache_tree_update(index_state, flags) < 0)
 668                 return WRITE_TREE_UNMERGED_INDEX;
 669
 670         if (prefix) {
 671                 struct cache_tree *subtree;
 672                 subtree = cache_tree_find(index_state->cache_tree, prefix);
 673                 if (!subtree)
 674                         return WRITE_TREE_PREFIX_ERROR;
 675                 oidcpy(oid, &subtree->oid);
 676         }
 677         else
 678                 oidcpy(oid, &index_state->cache_tree->oid);
 679
 680         return 0;
 681 }
 682
 683 struct tree* write_in_core_index_as_tree(struct repository *repo) {
 684         struct object_id o;
 685         int was_valid, ret;
 686
 687         struct index_state *index_state = repo->index;
 688         was_valid = index_state->cache_tree &&
 689                     cache_tree_fully_valid(index_state->cache_tree);
 690
 691         ret = write_index_as_tree_internal(&o, index_state, was_valid, 0, NULL);
 692         if (ret == WRITE_TREE_UNMERGED_INDEX) {
 693                 int i;
 694                 fprintf(stderr, "BUG: There are unmerged index entries:\n");
 695                 for (i = 0; i < index_state->cache_nr; i++) {
 696                         const struct cache_entry *ce = index_state->cache[i];
 697                         if (ce_stage(ce))
 698                                 fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
 699                                         (int)ce_namelen(ce), ce->name);
 700                 }
 701                 BUG("unmerged index entries when writing inmemory index");
 702         }
 703
 704         return lookup_tree(repo, &index_state->cache_tree->oid);
 705 }
 706
 707
 708 int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix)
 709 {
 710         int entries, was_valid;
 711         struct lock_file lock_file = LOCK_INIT;
 712         int ret;
 713
 714         hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
 715
 716         entries = read_index_from(index_state, index_path, get_git_dir());
 717         if (entries < 0) {
 718                 ret = WRITE_TREE_UNREADABLE_INDEX;
 719                 goto out;
 720         }
 721
 722         was_valid = !(flags & WRITE_TREE_IGNORE_CACHE_TREE) &&
 723                     index_state->cache_tree &&
 724                     cache_tree_fully_valid(index_state->cache_tree);
 725
 726         ret = write_index_as_tree_internal(oid, index_state, was_valid, flags,
 727                                            prefix);
 728         if (!ret && !was_valid) {
 729                 write_locked_index(index_state, &lock_file, COMMIT_LOCK);
 730                 /* Not being able to write is fine -- we are only interested
 731                  * in updating the cache-tree part, and if the next caller
 732                  * ends up using the old index with unupdated cache-tree part
 733                  * it misses the work we did here, but that is just a
 734                  * performance penalty and not a big deal.
 735                  */
 736         }
 737
 738 out:
 739         rollback_lock_file(&lock_file);
 740         return ret;
 741 }
 742
 743 static void prime_cache_tree_rec(struct repository *r,
 744                                  struct cache_tree *it,
 745                                  struct tree *tree)
 746 {
 747         struct tree_desc desc;
 748         struct name_entry entry;
 749         int cnt;
 750
 751         oidcpy(&it->oid, &tree->object.oid);
 752         init_tree_desc(&desc, tree->buffer, tree->size);
 753         cnt = 0;
 754         while (tree_entry(&desc, &entry)) {
 755                 if (!S_ISDIR(entry.mode))
 756                         cnt++;
 757                 else {
 758                         struct cache_tree_sub *sub;
 759                         struct tree *subtree = lookup_tree(r, &entry.oid);
 760                         if (!subtree->object.parsed)
 761                                 parse_tree(subtree);
 762                         sub = cache_tree_sub(it, entry.path);
 763                         sub->cache_tree = cache_tree();
 764                         prime_cache_tree_rec(r, sub->cache_tree, subtree);
 765                         cnt += sub->cache_tree->entry_count;
 766                 }
 767         }
 768         it->entry_count = cnt;
 769 }
 770
 771 void prime_cache_tree(struct repository *r,
 772                       struct index_state *istate,
 773                       struct tree *tree)
 774 {
 775         trace2_region_enter("cache-tree", "prime_cache_tree", the_repository);
 776         cache_tree_free(&istate->cache_tree);
 777         istate->cache_tree = cache_tree();
 778
 779         prime_cache_tree_rec(r, istate->cache_tree, tree);
 780         istate->cache_changed |= CACHE_TREE_CHANGED;
 781         trace2_region_leave("cache-tree", "prime_cache_tree", the_repository);
 782 }
 783
 784 /*
 785  * find the cache_tree that corresponds to the current level without
 786  * exploding the full path into textual form.  The root of the
 787  * cache tree is given as "root", and our current level is "info".
 788  * (1) When at root level, info->prev is NULL, so it is "root" itself.
 789  * (2) Otherwise, find the cache_tree that corresponds to one level
 790  *     above us, and find ourselves in there.
 791  */
 792 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
 793                                                          struct traverse_info *info)
 794 {
 795         struct cache_tree *our_parent;
 796
 797         if (!info->prev)
 798                 return root;
 799         our_parent = find_cache_tree_from_traversal(root, info->prev);
 800         return cache_tree_find(our_parent, info->name);
 801 }
 802
 803 int cache_tree_matches_traversal(struct cache_tree *root,
 804                                  struct name_entry *ent,
 805                                  struct traverse_info *info)
 806 {
 807         struct cache_tree *it;
 808
 809         it = find_cache_tree_from_traversal(root, info);
 810         it = cache_tree_find(it, ent->path);
 811         if (it && it->entry_count > 0 && oideq(&ent->oid, &it->oid))
 812                 return it->entry_count;
 813         return 0;
 814 }
 815
 816 static void verify_one_sparse(struct repository *r,
 817                               struct index_state *istate,
 818                               struct cache_tree *it,
 819                               struct strbuf *path,
 820                               int pos)
 821 {
 822         struct cache_entry *ce = istate->cache[pos];
 823
 824         if (!S_ISSPARSEDIR(ce->ce_mode))
 825                 BUG("directory '%s' is present in index, but not sparse",
 826                     path->buf);
 827 }
 828
 829 static void verify_one(struct repository *r,
 830                        struct index_state *istate,
 831                        struct cache_tree *it,
 832                        struct strbuf *path)
 833 {
 834         int i, pos, len = path->len;
 835         struct strbuf tree_buf = STRBUF_INIT;
 836         struct object_id new_oid;
 837
 838         for (i = 0; i < it->subtree_nr; i++) {
 839                 strbuf_addf(path, "%s/", it->down[i]->name);
 840                 verify_one(r, istate, it->down[i]->cache_tree, path);
 841                 strbuf_setlen(path, len);
 842         }
 843
 844         if (it->entry_count < 0 ||
 845             /* no verification on tests (t7003) that replace trees */
 846             lookup_replace_object(r, &it->oid) != &it->oid)
 847                 return;
 848
 849         if (path->len) {
 850                 pos = index_name_pos(istate, path->buf, path->len);
 851
 852                 if (pos >= 0) {
 853                         verify_one_sparse(r, istate, it, path, pos);
 854                         return;
 855                 }
 856
 857                 pos = -pos - 1;
 858         } else {
 859                 pos = 0;
 860         }
 861
 862         i = 0;
 863         while (i < it->entry_count) {
 864                 struct cache_entry *ce = istate->cache[pos + i];
 865                 const char *slash;
 866                 struct cache_tree_sub *sub = NULL;
 867                 const struct object_id *oid;
 868                 const char *name;
 869                 unsigned mode;
 870                 int entlen;
 871
 872                 if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE))
 873                         BUG("%s with flags 0x%x should not be in cache-tree",
 874                             ce->name, ce->ce_flags);
 875                 name = ce->name + path->len;
 876                 slash = strchr(name, '/');
 877                 if (slash) {
 878                         entlen = slash - name;
 879                         sub = find_subtree(it, ce->name + path->len, entlen, 0);
 880                         if (!sub || sub->cache_tree->entry_count < 0)
 881                                 BUG("bad subtree '%.*s'", entlen, name);
 882                         oid = &sub->cache_tree->oid;
 883                         mode = S_IFDIR;
 884                         i += sub->cache_tree->entry_count;
 885                 } else {
 886                         oid = &ce->oid;
 887                         mode = ce->ce_mode;
 888                         entlen = ce_namelen(ce) - path->len;
 889                         i++;
 890                 }
 891                 strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0');
 892                 strbuf_add(&tree_buf, oid->hash, r->hash_algo->rawsz);
 893         }
 894         hash_object_file(r->hash_algo, tree_buf.buf, tree_buf.len, tree_type,
 895                          &new_oid);
 896         if (!oideq(&new_oid, &it->oid))
 897                 BUG("cache-tree for path %.*s does not match. "
 898                     "Expected %s got %s", len, path->buf,
 899                     oid_to_hex(&new_oid), oid_to_hex(&it->oid));
 900         strbuf_setlen(path, len);
 901         strbuf_release(&tree_buf);
 902 }
 903
 904 void cache_tree_verify(struct repository *r, struct index_state *istate)
 905 {
 906         struct strbuf path = STRBUF_INIT;
 907
 908         if (!istate->cache_tree)
 909                 return;
 910         verify_one(r, istate, istate->cache_tree, &path);
 911         strbuf_release(&path);
 912 }