cache-tree.c

   1 #include "git-compat-util.h"
   2 #include "alloc.h"
   3 #include "hex.h"
   4 #include "lockfile.h"
   5 #include "tree.h"
   6 #include "tree-walk.h"
   7 #include "cache-tree.h"
   8 #include "bulk-checkin.h"
   9 #include "object-store.h"
  10 #include "replace-object.h"
  11 #include "promisor-remote.h"
  12 #include "sparse-index.h"
  13
  14 #ifndef DEBUG_CACHE_TREE
  15 #define DEBUG_CACHE_TREE 0
  16 #endif
  17
  18 struct cache_tree *cache_tree(void)
  19 {
  20         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  21         it->entry_count = -1;
  22         return it;
  23 }
  24
  25 void cache_tree_free(struct cache_tree **it_p)
  26 {
  27         int i;
  28         struct cache_tree *it = *it_p;
  29
  30         if (!it)
  31                 return;
  32         for (i = 0; i < it->subtree_nr; i++)
  33                 if (it->down[i]) {
  34                         cache_tree_free(&it->down[i]->cache_tree);
  35                         free(it->down[i]);
  36                 }
  37         free(it->down);
  38         free(it);
  39         *it_p = NULL;
  40 }
  41
  42 static int subtree_name_cmp(const char *one, int onelen,
  43                             const char *two, int twolen)
  44 {
  45         if (onelen < twolen)
  46                 return -1;
  47         if (twolen < onelen)
  48                 return 1;
  49         return memcmp(one, two, onelen);
  50 }
  51
  52 int cache_tree_subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  53 {
  54         struct cache_tree_sub **down = it->down;
  55         int lo, hi;
  56         lo = 0;
  57         hi = it->subtree_nr;
  58         while (lo < hi) {
  59                 int mi = lo + (hi - lo) / 2;
  60                 struct cache_tree_sub *mdl = down[mi];
  61                 int cmp = subtree_name_cmp(path, pathlen,
  62                                            mdl->name, mdl->namelen);
  63                 if (!cmp)
  64                         return mi;
  65                 if (cmp < 0)
  66                         hi = mi;
  67                 else
  68                         lo = mi + 1;
  69         }
  70         return -lo-1;
  71 }
  72
  73 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  74                                            const char *path,
  75                                            int pathlen,
  76                                            int create)
  77 {
  78         struct cache_tree_sub *down;
  79         int pos = cache_tree_subtree_pos(it, path, pathlen);
  80         if (0 <= pos)
  81                 return it->down[pos];
  82         if (!create)
  83                 return NULL;
  84
  85         pos = -pos-1;
  86         ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
  87         it->subtree_nr++;
  88
  89         FLEX_ALLOC_MEM(down, name, path, pathlen);
  90         down->cache_tree = NULL;
  91         down->namelen = pathlen;
  92
  93         if (pos < it->subtree_nr)
  94                 MOVE_ARRAY(it->down + pos + 1, it->down + pos,
  95                            it->subtree_nr - pos - 1);
  96         it->down[pos] = down;
  97         return down;
  98 }
  99
 100 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
 101 {
 102         int pathlen = strlen(path);
 103         return find_subtree(it, path, pathlen, 1);
 104 }
 105
 106 static int do_invalidate_path(struct cache_tree *it, const char *path)
 107 {
 108         /* a/b/c
 109          * ==> invalidate self
 110          * ==> find "a", have it invalidate "b/c"
 111          * a
 112          * ==> invalidate self
 113          * ==> if "a" exists as a subtree, remove it.
 114          */
 115         const char *slash;
 116         int namelen;
 117         struct cache_tree_sub *down;
 118
 119 #if DEBUG_CACHE_TREE
 120         fprintf(stderr, "cache-tree invalidate <%s>\n", path);
 121 #endif
 122
 123         if (!it)
 124                 return 0;
 125         slash = strchrnul(path, '/');
 126         namelen = slash - path;
 127         it->entry_count = -1;
 128         if (!*slash) {
 129                 int pos;
 130                 pos = cache_tree_subtree_pos(it, path, namelen);
 131                 if (0 <= pos) {
 132                         cache_tree_free(&it->down[pos]->cache_tree);
 133                         free(it->down[pos]);
 134                         /* 0 1 2 3 4 5
 135                          *       ^     ^subtree_nr = 6
 136                          *       pos
 137                          * move 4 and 5 up one place (2 entries)
 138                          * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 139                          */
 140                         MOVE_ARRAY(it->down + pos, it->down + pos + 1,
 141                                    it->subtree_nr - pos - 1);
 142                         it->subtree_nr--;
 143                 }
 144                 return 1;
 145         }
 146         down = find_subtree(it, path, namelen, 0);
 147         if (down)
 148                 do_invalidate_path(down->cache_tree, slash + 1);
 149         return 1;
 150 }
 151
 152 void cache_tree_invalidate_path(struct index_state *istate, const char *path)
 153 {
 154         if (do_invalidate_path(istate->cache_tree, path))
 155                 istate->cache_changed |= CACHE_TREE_CHANGED;
 156 }
 157
 158 static int verify_cache(struct index_state *istate, int flags)
 159 {
 160         unsigned i, funny;
 161         int silent = flags & WRITE_TREE_SILENT;
 162
 163         /* Verify that the tree is merged */
 164         funny = 0;
 165         for (i = 0; i < istate->cache_nr; i++) {
 166                 const struct cache_entry *ce = istate->cache[i];
 167                 if (ce_stage(ce)) {
 168                         if (silent)
 169                                 return -1;
 170                         if (10 < ++funny) {
 171                                 fprintf(stderr, "...\n");
 172                                 break;
 173                         }
 174                         fprintf(stderr, "%s: unmerged (%s)\n",
 175                                 ce->name, oid_to_hex(&ce->oid));
 176                 }
 177         }
 178         if (funny)
 179                 return -1;
 180
 181         /* Also verify that the cache does not have path and path/file
 182          * at the same time.  At this point we know the cache has only
 183          * stage 0 entries.
 184          */
 185         funny = 0;
 186         for (i = 0; i + 1 < istate->cache_nr; i++) {
 187                 /* path/file always comes after path because of the way
 188                  * the cache is sorted.  Also path can appear only once,
 189                  * which means conflicting one would immediately follow.
 190                  */
 191                 const struct cache_entry *this_ce = istate->cache[i];
 192                 const struct cache_entry *next_ce = istate->cache[i + 1];
 193                 const char *this_name = this_ce->name;
 194                 const char *next_name = next_ce->name;
 195                 int this_len = ce_namelen(this_ce);
 196                 if (this_len < ce_namelen(next_ce) &&
 197                     next_name[this_len] == '/' &&
 198                     strncmp(this_name, next_name, this_len) == 0) {
 199                         if (10 < ++funny) {
 200                                 fprintf(stderr, "...\n");
 201                                 break;
 202                         }
 203                         fprintf(stderr, "You have both %s and %s\n",
 204                                 this_name, next_name);
 205                 }
 206         }
 207         if (funny)
 208                 return -1;
 209         return 0;
 210 }
 211
 212 static void discard_unused_subtrees(struct cache_tree *it)
 213 {
 214         struct cache_tree_sub **down = it->down;
 215         int nr = it->subtree_nr;
 216         int dst, src;
 217         for (dst = src = 0; src < nr; src++) {
 218                 struct cache_tree_sub *s = down[src];
 219                 if (s->used)
 220                         down[dst++] = s;
 221                 else {
 222                         cache_tree_free(&s->cache_tree);
 223                         free(s);
 224                         it->subtree_nr--;
 225                 }
 226         }
 227 }
 228
 229 int cache_tree_fully_valid(struct cache_tree *it)
 230 {
 231         int i;
 232         if (!it)
 233                 return 0;
 234         if (it->entry_count < 0 || !has_object_file(&it->oid))
 235                 return 0;
 236         for (i = 0; i < it->subtree_nr; i++) {
 237                 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
 238                         return 0;
 239         }
 240         return 1;
 241 }
 242
 243 static int must_check_existence(const struct cache_entry *ce)
 244 {
 245         return !(has_promisor_remote() && ce_skip_worktree(ce));
 246 }
 247
 248 static int update_one(struct cache_tree *it,
 249                       struct cache_entry **cache,
 250                       int entries,
 251                       const char *base,
 252                       int baselen,
 253                       int *skip_count,
 254                       int flags)
 255 {
 256         struct strbuf buffer;
 257         int missing_ok = flags & WRITE_TREE_MISSING_OK;
 258         int dryrun = flags & WRITE_TREE_DRY_RUN;
 259         int repair = flags & WRITE_TREE_REPAIR;
 260         int to_invalidate = 0;
 261         int i;
 262
 263         assert(!(dryrun && repair));
 264
 265         *skip_count = 0;
 266
 267         /*
 268          * If the first entry of this region is a sparse directory
 269          * entry corresponding exactly to 'base', then this cache_tree
 270          * struct is a "leaf" in the data structure, pointing to the
 271          * tree OID specified in the entry.
 272          */
 273         if (entries > 0) {
 274                 const struct cache_entry *ce = cache[0];
 275
 276                 if (S_ISSPARSEDIR(ce->ce_mode) &&
 277                     ce->ce_namelen == baselen &&
 278                     !strncmp(ce->name, base, baselen)) {
 279                         it->entry_count = 1;
 280                         oidcpy(&it->oid, &ce->oid);
 281                         return 1;
 282                 }
 283         }
 284
 285         if (0 <= it->entry_count && has_object_file(&it->oid))
 286                 return it->entry_count;
 287
 288         /*
 289          * We first scan for subtrees and update them; we start by
 290          * marking existing subtrees -- the ones that are unmarked
 291          * should not be in the result.
 292          */
 293         for (i = 0; i < it->subtree_nr; i++)
 294                 it->down[i]->used = 0;
 295
 296         /*
 297          * Find the subtrees and update them.
 298          */
 299         i = 0;
 300         while (i < entries) {
 301                 const struct cache_entry *ce = cache[i];
 302                 struct cache_tree_sub *sub;
 303                 const char *path, *slash;
 304                 int pathlen, sublen, subcnt, subskip;
 305
 306                 path = ce->name;
 307                 pathlen = ce_namelen(ce);
 308                 if (pathlen <= baselen || memcmp(base, path, baselen))
 309                         break; /* at the end of this level */
 310
 311                 slash = strchr(path + baselen, '/');
 312                 if (!slash) {
 313                         i++;
 314                         continue;
 315                 }
 316                 /*
 317                  * a/bbb/c (base = a/, slash = /c)
 318                  * ==>
 319                  * path+baselen = bbb/c, sublen = 3
 320                  */
 321                 sublen = slash - (path + baselen);
 322                 sub = find_subtree(it, path + baselen, sublen, 1);
 323                 if (!sub->cache_tree)
 324                         sub->cache_tree = cache_tree();
 325                 subcnt = update_one(sub->cache_tree,
 326                                     cache + i, entries - i,
 327                                     path,
 328                                     baselen + sublen + 1,
 329                                     &subskip,
 330                                     flags);
 331                 if (subcnt < 0)
 332                         return subcnt;
 333                 if (!subcnt)
 334                         die("index cache-tree records empty sub-tree");
 335                 i += subcnt;
 336                 sub->count = subcnt; /* to be used in the next loop */
 337                 *skip_count += subskip;
 338                 sub->used = 1;
 339         }
 340
 341         discard_unused_subtrees(it);
 342
 343         /*
 344          * Then write out the tree object for this level.
 345          */
 346         strbuf_init(&buffer, 8192);
 347
 348         i = 0;
 349         while (i < entries) {
 350                 const struct cache_entry *ce = cache[i];
 351                 struct cache_tree_sub *sub = NULL;
 352                 const char *path, *slash;
 353                 int pathlen, entlen;
 354                 const struct object_id *oid;
 355                 unsigned mode;
 356                 int expected_missing = 0;
 357                 int contains_ita = 0;
 358                 int ce_missing_ok;
 359
 360                 path = ce->name;
 361                 pathlen = ce_namelen(ce);
 362                 if (pathlen <= baselen || memcmp(base, path, baselen))
 363                         break; /* at the end of this level */
 364
 365                 slash = strchr(path + baselen, '/');
 366                 if (slash) {
 367                         entlen = slash - (path + baselen);
 368                         sub = find_subtree(it, path + baselen, entlen, 0);
 369                         if (!sub)
 370                                 die("cache-tree.c: '%.*s' in '%s' not found",
 371                                     entlen, path + baselen, path);
 372                         i += sub->count;
 373                         oid = &sub->cache_tree->oid;
 374                         mode = S_IFDIR;
 375                         contains_ita = sub->cache_tree->entry_count < 0;
 376                         if (contains_ita) {
 377                                 to_invalidate = 1;
 378                                 expected_missing = 1;
 379                         }
 380                 }
 381                 else {
 382                         oid = &ce->oid;
 383                         mode = ce->ce_mode;
 384                         entlen = pathlen - baselen;
 385                         i++;
 386                 }
 387
 388                 ce_missing_ok = mode == S_IFGITLINK || missing_ok ||
 389                         !must_check_existence(ce);
 390                 if (is_null_oid(oid) ||
 391                     (!ce_missing_ok && !has_object_file(oid))) {
 392                         strbuf_release(&buffer);
 393                         if (expected_missing)
 394                                 return -1;
 395                         return error("invalid object %06o %s for '%.*s'",
 396                                 mode, oid_to_hex(oid), entlen+baselen, path);
 397                 }
 398
 399                 /*
 400                  * CE_REMOVE entries are removed before the index is
 401                  * written to disk. Skip them to remain consistent
 402                  * with the future on-disk index.
 403                  */
 404                 if (ce->ce_flags & CE_REMOVE) {
 405                         *skip_count = *skip_count + 1;
 406                         continue;
 407                 }
 408
 409                 /*
 410                  * CE_INTENT_TO_ADD entries exist in on-disk index but
 411                  * they are not part of generated trees. Invalidate up
 412                  * to root to force cache-tree users to read elsewhere.
 413                  */
 414                 if (!sub && ce_intent_to_add(ce)) {
 415                         to_invalidate = 1;
 416                         continue;
 417                 }
 418
 419                 /*
 420                  * "sub" can be an empty tree if all subentries are i-t-a.
 421                  */
 422                 if (contains_ita && is_empty_tree_oid(oid))
 423                         continue;
 424
 425                 strbuf_grow(&buffer, entlen + 100);
 426                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
 427                 strbuf_add(&buffer, oid->hash, the_hash_algo->rawsz);
 428
 429 #if DEBUG_CACHE_TREE
 430                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
 431                         mode, entlen, path + baselen);
 432 #endif
 433         }
 434
 435         if (repair) {
 436                 struct object_id oid;
 437                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 438                                  OBJ_TREE, &oid);
 439                 if (has_object_file_with_flags(&oid, OBJECT_INFO_SKIP_FETCH_OBJECT))
 440                         oidcpy(&it->oid, &oid);
 441                 else
 442                         to_invalidate = 1;
 443         } else if (dryrun) {
 444                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 445                                  OBJ_TREE, &it->oid);
 446         } else if (write_object_file_flags(buffer.buf, buffer.len, OBJ_TREE,
 447                                            &it->oid, flags & WRITE_TREE_SILENT
 448                                            ? HASH_SILENT : 0)) {
 449                 strbuf_release(&buffer);
 450                 return -1;
 451         }
 452
 453         strbuf_release(&buffer);
 454         it->entry_count = to_invalidate ? -1 : i - *skip_count;
 455 #if DEBUG_CACHE_TREE
 456         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
 457                 it->entry_count, it->subtree_nr,
 458                 oid_to_hex(&it->oid));
 459 #endif
 460         return i;
 461 }
 462
 463 int cache_tree_update(struct index_state *istate, int flags)
 464 {
 465         int skip, i;
 466
 467         i = verify_cache(istate, flags);
 468
 469         if (i)
 470                 return i;
 471
 472         if (!istate->cache_tree)
 473                 istate->cache_tree = cache_tree();
 474
 475         if (!(flags & WRITE_TREE_MISSING_OK) && has_promisor_remote())
 476                 prefetch_cache_entries(istate, must_check_existence);
 477
 478         trace_performance_enter();
 479         trace2_region_enter("cache_tree", "update", the_repository);
 480         begin_odb_transaction();
 481         i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
 482                        "", 0, &skip, flags);
 483         end_odb_transaction();
 484         trace2_region_leave("cache_tree", "update", the_repository);
 485         trace_performance_leave("cache_tree_update");
 486         if (i < 0)
 487                 return i;
 488         istate->cache_changed |= CACHE_TREE_CHANGED;
 489         return 0;
 490 }
 491
 492 static void write_one(struct strbuf *buffer, struct cache_tree *it,
 493                       const char *path, int pathlen)
 494 {
 495         int i;
 496
 497         /* One "cache-tree" entry consists of the following:
 498          * path (NUL terminated)
 499          * entry_count, subtree_nr ("%d %d\n")
 500          * tree-sha1 (missing if invalid)
 501          * subtree_nr "cache-tree" entries for subtrees.
 502          */
 503         strbuf_grow(buffer, pathlen + 100);
 504         strbuf_add(buffer, path, pathlen);
 505         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 506
 507 #if DEBUG_CACHE_TREE
 508         if (0 <= it->entry_count)
 509                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 510                         pathlen, path, it->entry_count, it->subtree_nr,
 511                         oid_to_hex(&it->oid));
 512         else
 513                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 514                         pathlen, path, it->subtree_nr);
 515 #endif
 516
 517         if (0 <= it->entry_count) {
 518                 strbuf_add(buffer, it->oid.hash, the_hash_algo->rawsz);
 519         }
 520         for (i = 0; i < it->subtree_nr; i++) {
 521                 struct cache_tree_sub *down = it->down[i];
 522                 if (i) {
 523                         struct cache_tree_sub *prev = it->down[i-1];
 524                         if (subtree_name_cmp(down->name, down->namelen,
 525                                              prev->name, prev->namelen) <= 0)
 526                                 die("fatal - unsorted cache subtree");
 527                 }
 528                 write_one(buffer, down->cache_tree, down->name, down->namelen);
 529         }
 530 }
 531
 532 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
 533 {
 534         trace2_region_enter("cache_tree", "write", the_repository);
 535         write_one(sb, root, "", 0);
 536         trace2_region_leave("cache_tree", "write", the_repository);
 537 }
 538
 539 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 540 {
 541         const char *buf = *buffer;
 542         unsigned long size = *size_p;
 543         const char *cp;
 544         char *ep;
 545         struct cache_tree *it;
 546         int i, subtree_nr;
 547         const unsigned rawsz = the_hash_algo->rawsz;
 548
 549         it = NULL;
 550         /* skip name, but make sure name exists */
 551         while (size && *buf) {
 552                 size--;
 553                 buf++;
 554         }
 555         if (!size)
 556                 goto free_return;
 557         buf++; size--;
 558         it = cache_tree();
 559
 560         cp = buf;
 561         it->entry_count = strtol(cp, &ep, 10);
 562         if (cp == ep)
 563                 goto free_return;
 564         cp = ep;
 565         subtree_nr = strtol(cp, &ep, 10);
 566         if (cp == ep)
 567                 goto free_return;
 568         while (size && *buf && *buf != '\n') {
 569                 size--;
 570                 buf++;
 571         }
 572         if (!size)
 573                 goto free_return;
 574         buf++; size--;
 575         if (0 <= it->entry_count) {
 576                 if (size < rawsz)
 577                         goto free_return;
 578                 oidread(&it->oid, (const unsigned char *)buf);
 579                 buf += rawsz;
 580                 size -= rawsz;
 581         }
 582
 583 #if DEBUG_CACHE_TREE
 584         if (0 <= it->entry_count)
 585                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 586                         *buffer, it->entry_count, subtree_nr,
 587                         oid_to_hex(&it->oid));
 588         else
 589                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 590                         *buffer, subtree_nr);
 591 #endif
 592
 593         /*
 594          * Just a heuristic -- we do not add directories that often but
 595          * we do not want to have to extend it immediately when we do,
 596          * hence +2.
 597          */
 598         it->subtree_alloc = subtree_nr + 2;
 599         CALLOC_ARRAY(it->down, it->subtree_alloc);
 600         for (i = 0; i < subtree_nr; i++) {
 601                 /* read each subtree */
 602                 struct cache_tree *sub;
 603                 struct cache_tree_sub *subtree;
 604                 const char *name = buf;
 605
 606                 sub = read_one(&buf, &size);
 607                 if (!sub)
 608                         goto free_return;
 609                 subtree = cache_tree_sub(it, name);
 610                 subtree->cache_tree = sub;
 611         }
 612         if (subtree_nr != it->subtree_nr)
 613                 die("cache-tree: internal error");
 614         *buffer = buf;
 615         *size_p = size;
 616         return it;
 617
 618  free_return:
 619         cache_tree_free(&it);
 620         return NULL;
 621 }
 622
 623 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 624 {
 625         struct cache_tree *result;
 626
 627         if (buffer[0])
 628                 return NULL; /* not the whole tree */
 629
 630         trace2_region_enter("cache_tree", "read", the_repository);
 631         result = read_one(&buffer, &size);
 632         trace2_region_leave("cache_tree", "read", the_repository);
 633
 634         return result;
 635 }
 636
 637 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 638 {
 639         if (!it)
 640                 return NULL;
 641         while (*path) {
 642                 const char *slash;
 643                 struct cache_tree_sub *sub;
 644
 645                 slash = strchrnul(path, '/');
 646                 /*
 647                  * Between path and slash is the name of the subtree
 648                  * to look for.
 649                  */
 650                 sub = find_subtree(it, path, slash - path, 0);
 651                 if (!sub)
 652                         return NULL;
 653                 it = sub->cache_tree;
 654
 655                 path = slash;
 656                 while (*path == '/')
 657                         path++;
 658         }
 659         return it;
 660 }
 661
 662 static int write_index_as_tree_internal(struct object_id *oid,
 663                                         struct index_state *index_state,
 664                                         int cache_tree_valid,
 665                                         int flags,
 666                                         const char *prefix)
 667 {
 668         if (flags & WRITE_TREE_IGNORE_CACHE_TREE) {
 669                 cache_tree_free(&index_state->cache_tree);
 670                 cache_tree_valid = 0;
 671         }
 672
 673         if (!cache_tree_valid && cache_tree_update(index_state, flags) < 0)
 674                 return WRITE_TREE_UNMERGED_INDEX;
 675
 676         if (prefix) {
 677                 struct cache_tree *subtree;
 678                 subtree = cache_tree_find(index_state->cache_tree, prefix);
 679                 if (!subtree)
 680                         return WRITE_TREE_PREFIX_ERROR;
 681                 oidcpy(oid, &subtree->oid);
 682         }
 683         else
 684                 oidcpy(oid, &index_state->cache_tree->oid);
 685
 686         return 0;
 687 }
 688
 689 struct tree* write_in_core_index_as_tree(struct repository *repo) {
 690         struct object_id o;
 691         int was_valid, ret;
 692
 693         struct index_state *index_state = repo->index;
 694         was_valid = index_state->cache_tree &&
 695                     cache_tree_fully_valid(index_state->cache_tree);
 696
 697         ret = write_index_as_tree_internal(&o, index_state, was_valid, 0, NULL);
 698         if (ret == WRITE_TREE_UNMERGED_INDEX) {
 699                 int i;
 700                 bug("there are unmerged index entries:");
 701                 for (i = 0; i < index_state->cache_nr; i++) {
 702                         const struct cache_entry *ce = index_state->cache[i];
 703                         if (ce_stage(ce))
 704                                 bug("%d %.*s", ce_stage(ce),
 705                                     (int)ce_namelen(ce), ce->name);
 706                 }
 707                 BUG("unmerged index entries when writing in-core index");
 708         }
 709
 710         return lookup_tree(repo, &index_state->cache_tree->oid);
 711 }
 712
 713
 714 int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix)
 715 {
 716         int entries, was_valid;
 717         struct lock_file lock_file = LOCK_INIT;
 718         int ret;
 719
 720         hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
 721
 722         entries = read_index_from(index_state, index_path, get_git_dir());
 723         if (entries < 0) {
 724                 ret = WRITE_TREE_UNREADABLE_INDEX;
 725                 goto out;
 726         }
 727
 728         was_valid = !(flags & WRITE_TREE_IGNORE_CACHE_TREE) &&
 729                     index_state->cache_tree &&
 730                     cache_tree_fully_valid(index_state->cache_tree);
 731
 732         ret = write_index_as_tree_internal(oid, index_state, was_valid, flags,
 733                                            prefix);
 734         if (!ret && !was_valid) {
 735                 write_locked_index(index_state, &lock_file, COMMIT_LOCK);
 736                 /* Not being able to write is fine -- we are only interested
 737                  * in updating the cache-tree part, and if the next caller
 738                  * ends up using the old index with unupdated cache-tree part
 739                  * it misses the work we did here, but that is just a
 740                  * performance penalty and not a big deal.
 741                  */
 742         }
 743
 744 out:
 745         rollback_lock_file(&lock_file);
 746         return ret;
 747 }
 748
 749 static void prime_cache_tree_sparse_dir(struct cache_tree *it,
 750                                         struct tree *tree)
 751 {
 752
 753         oidcpy(&it->oid, &tree->object.oid);
 754         it->entry_count = 1;
 755 }
 756
 757 static void prime_cache_tree_rec(struct repository *r,
 758                                  struct cache_tree *it,
 759                                  struct tree *tree,
 760                                  struct strbuf *tree_path)
 761 {
 762         struct tree_desc desc;
 763         struct name_entry entry;
 764         int cnt;
 765         size_t base_path_len = tree_path->len;
 766
 767         oidcpy(&it->oid, &tree->object.oid);
 768
 769         init_tree_desc(&desc, tree->buffer, tree->size);
 770         cnt = 0;
 771         while (tree_entry(&desc, &entry)) {
 772                 if (!S_ISDIR(entry.mode))
 773                         cnt++;
 774                 else {
 775                         struct cache_tree_sub *sub;
 776                         struct tree *subtree = lookup_tree(r, &entry.oid);
 777
 778                         if (!subtree->object.parsed)
 779                                 parse_tree(subtree);
 780                         sub = cache_tree_sub(it, entry.path);
 781                         sub->cache_tree = cache_tree();
 782
 783                         /*
 784                          * Recursively-constructed subtree path is only needed when working
 785                          * in a sparse index (where it's used to determine whether the
 786                          * subtree is a sparse directory in the index).
 787                          */
 788                         if (r->index->sparse_index) {
 789                                 strbuf_setlen(tree_path, base_path_len);
 790                                 strbuf_add(tree_path, entry.path, entry.pathlen);
 791                                 strbuf_addch(tree_path, '/');
 792                         }
 793
 794                         /*
 795                          * If a sparse index is in use, the directory being processed may be
 796                          * sparse. To confirm that, we can check whether an entry with that
 797                          * exact name exists in the index. If it does, the created subtree
 798                          * should be sparse. Otherwise, cache tree expansion should continue
 799                          * as normal.
 800                          */
 801                         if (r->index->sparse_index &&
 802                             index_entry_exists(r->index, tree_path->buf, tree_path->len))
 803                                 prime_cache_tree_sparse_dir(sub->cache_tree, subtree);
 804                         else
 805                                 prime_cache_tree_rec(r, sub->cache_tree, subtree, tree_path);
 806                         cnt += sub->cache_tree->entry_count;
 807                 }
 808         }
 809
 810         it->entry_count = cnt;
 811 }
 812
 813 void prime_cache_tree(struct repository *r,
 814                       struct index_state *istate,
 815                       struct tree *tree)
 816 {
 817         struct strbuf tree_path = STRBUF_INIT;
 818
 819         trace2_region_enter("cache-tree", "prime_cache_tree", the_repository);
 820         cache_tree_free(&istate->cache_tree);
 821         istate->cache_tree = cache_tree();
 822
 823         prime_cache_tree_rec(r, istate->cache_tree, tree, &tree_path);
 824         strbuf_release(&tree_path);
 825         istate->cache_changed |= CACHE_TREE_CHANGED;
 826         trace2_region_leave("cache-tree", "prime_cache_tree", the_repository);
 827 }
 828
 829 /*
 830  * find the cache_tree that corresponds to the current level without
 831  * exploding the full path into textual form.  The root of the
 832  * cache tree is given as "root", and our current level is "info".
 833  * (1) When at root level, info->prev is NULL, so it is "root" itself.
 834  * (2) Otherwise, find the cache_tree that corresponds to one level
 835  *     above us, and find ourselves in there.
 836  */
 837 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
 838                                                          struct traverse_info *info)
 839 {
 840         struct cache_tree *our_parent;
 841
 842         if (!info->prev)
 843                 return root;
 844         our_parent = find_cache_tree_from_traversal(root, info->prev);
 845         return cache_tree_find(our_parent, info->name);
 846 }
 847
 848 int cache_tree_matches_traversal(struct cache_tree *root,
 849                                  struct name_entry *ent,
 850                                  struct traverse_info *info)
 851 {
 852         struct cache_tree *it;
 853
 854         it = find_cache_tree_from_traversal(root, info);
 855         it = cache_tree_find(it, ent->path);
 856         if (it && it->entry_count > 0 && oideq(&ent->oid, &it->oid))
 857                 return it->entry_count;
 858         return 0;
 859 }
 860
 861 static void verify_one_sparse(struct index_state *istate,
 862                               struct strbuf *path,
 863                               int pos)
 864 {
 865         struct cache_entry *ce = istate->cache[pos];
 866
 867         if (!S_ISSPARSEDIR(ce->ce_mode))
 868                 BUG("directory '%s' is present in index, but not sparse",
 869                     path->buf);
 870 }
 871
 872 /*
 873  * Returns:
 874  *  0 - Verification completed.
 875  *  1 - Restart verification - a call to ensure_full_index() freed the cache
 876  *      tree that is being verified and verification needs to be restarted from
 877  *      the new toplevel cache tree.
 878  */
 879 static int verify_one(struct repository *r,
 880                       struct index_state *istate,
 881                       struct cache_tree *it,
 882                       struct strbuf *path)
 883 {
 884         int i, pos, len = path->len;
 885         struct strbuf tree_buf = STRBUF_INIT;
 886         struct object_id new_oid;
 887
 888         for (i = 0; i < it->subtree_nr; i++) {
 889                 strbuf_addf(path, "%s/", it->down[i]->name);
 890                 if (verify_one(r, istate, it->down[i]->cache_tree, path))
 891                         return 1;
 892                 strbuf_setlen(path, len);
 893         }
 894
 895         if (it->entry_count < 0 ||
 896             /* no verification on tests (t7003) that replace trees */
 897             lookup_replace_object(r, &it->oid) != &it->oid)
 898                 return 0;
 899
 900         if (path->len) {
 901                 /*
 902                  * If the index is sparse and the cache tree is not
 903                  * index_name_pos() may trigger ensure_full_index() which will
 904                  * free the tree that is being verified.
 905                  */
 906                 int is_sparse = istate->sparse_index;
 907                 pos = index_name_pos(istate, path->buf, path->len);
 908                 if (is_sparse && !istate->sparse_index)
 909                         return 1;
 910
 911                 if (pos >= 0) {
 912                         verify_one_sparse(istate, path, pos);
 913                         return 0;
 914                 }
 915
 916                 pos = -pos - 1;
 917         } else {
 918                 pos = 0;
 919         }
 920
 921         i = 0;
 922         while (i < it->entry_count) {
 923                 struct cache_entry *ce = istate->cache[pos + i];
 924                 const char *slash;
 925                 struct cache_tree_sub *sub = NULL;
 926                 const struct object_id *oid;
 927                 const char *name;
 928                 unsigned mode;
 929                 int entlen;
 930
 931                 if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE))
 932                         BUG("%s with flags 0x%x should not be in cache-tree",
 933                             ce->name, ce->ce_flags);
 934                 name = ce->name + path->len;
 935                 slash = strchr(name, '/');
 936                 if (slash) {
 937                         entlen = slash - name;
 938                         sub = find_subtree(it, ce->name + path->len, entlen, 0);
 939                         if (!sub || sub->cache_tree->entry_count < 0)
 940                                 BUG("bad subtree '%.*s'", entlen, name);
 941                         oid = &sub->cache_tree->oid;
 942                         mode = S_IFDIR;
 943                         i += sub->cache_tree->entry_count;
 944                 } else {
 945                         oid = &ce->oid;
 946                         mode = ce->ce_mode;
 947                         entlen = ce_namelen(ce) - path->len;
 948                         i++;
 949                 }
 950                 strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0');
 951                 strbuf_add(&tree_buf, oid->hash, r->hash_algo->rawsz);
 952         }
 953         hash_object_file(r->hash_algo, tree_buf.buf, tree_buf.len, OBJ_TREE,
 954                          &new_oid);
 955         if (!oideq(&new_oid, &it->oid))
 956                 BUG("cache-tree for path %.*s does not match. "
 957                     "Expected %s got %s", len, path->buf,
 958                     oid_to_hex(&new_oid), oid_to_hex(&it->oid));
 959         strbuf_setlen(path, len);
 960         strbuf_release(&tree_buf);
 961         return 0;
 962 }
 963
 964 void cache_tree_verify(struct repository *r, struct index_state *istate)
 965 {
 966         struct strbuf path = STRBUF_INIT;
 967
 968         if (!istate->cache_tree)
 969                 return;
 970         if (verify_one(r, istate, istate->cache_tree, &path)) {
 971                 strbuf_reset(&path);
 972                 if (verify_one(r, istate, istate->cache_tree, &path))
 973                         BUG("ensure_full_index() called twice while verifying cache tree");
 974         }
 975         strbuf_release(&path);
 976 }