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 "bulk-checkin.h"
   7 #include "object-store.h"
   8 #include "replace-object.h"
   9 #include "promisor-remote.h"
  10 #include "sparse-index.h"
  11
  12 #ifndef DEBUG_CACHE_TREE
  13 #define DEBUG_CACHE_TREE 0
  14 #endif
  15
  16 struct cache_tree *cache_tree(void)
  17 {
  18         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  19         it->entry_count = -1;
  20         return it;
  21 }
  22
  23 void cache_tree_free(struct cache_tree **it_p)
  24 {
  25         int i;
  26         struct cache_tree *it = *it_p;
  27
  28         if (!it)
  29                 return;
  30         for (i = 0; i < it->subtree_nr; i++)
  31                 if (it->down[i]) {
  32                         cache_tree_free(&it->down[i]->cache_tree);
  33                         free(it->down[i]);
  34                 }
  35         free(it->down);
  36         free(it);
  37         *it_p = NULL;
  38 }
  39
  40 static int subtree_name_cmp(const char *one, int onelen,
  41                             const char *two, int twolen)
  42 {
  43         if (onelen < twolen)
  44                 return -1;
  45         if (twolen < onelen)
  46                 return 1;
  47         return memcmp(one, two, onelen);
  48 }
  49
  50 int cache_tree_subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  51 {
  52         struct cache_tree_sub **down = it->down;
  53         int lo, hi;
  54         lo = 0;
  55         hi = it->subtree_nr;
  56         while (lo < hi) {
  57                 int mi = lo + (hi - lo) / 2;
  58                 struct cache_tree_sub *mdl = down[mi];
  59                 int cmp = subtree_name_cmp(path, pathlen,
  60                                            mdl->name, mdl->namelen);
  61                 if (!cmp)
  62                         return mi;
  63                 if (cmp < 0)
  64                         hi = mi;
  65                 else
  66                         lo = mi + 1;
  67         }
  68         return -lo-1;
  69 }
  70
  71 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  72                                            const char *path,
  73                                            int pathlen,
  74                                            int create)
  75 {
  76         struct cache_tree_sub *down;
  77         int pos = cache_tree_subtree_pos(it, path, pathlen);
  78         if (0 <= pos)
  79                 return it->down[pos];
  80         if (!create)
  81                 return NULL;
  82
  83         pos = -pos-1;
  84         ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
  85         it->subtree_nr++;
  86
  87         FLEX_ALLOC_MEM(down, name, path, pathlen);
  88         down->cache_tree = NULL;
  89         down->namelen = pathlen;
  90
  91         if (pos < it->subtree_nr)
  92                 MOVE_ARRAY(it->down + pos + 1, it->down + pos,
  93                            it->subtree_nr - pos - 1);
  94         it->down[pos] = down;
  95         return down;
  96 }
  97
  98 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
  99 {
 100         int pathlen = strlen(path);
 101         return find_subtree(it, path, pathlen, 1);
 102 }
 103
 104 struct cache_tree *cache_tree_find_path(struct cache_tree *it, const char *path)
 105 {
 106         const char *slash;
 107         int namelen;
 108         struct cache_tree_sub it_sub = {
 109                 .cache_tree = it,
 110         };
 111         struct cache_tree_sub *down = &it_sub;
 112
 113         while (down) {
 114                 slash = strchrnul(path, '/');
 115                 namelen = slash - path;
 116                 down->cache_tree->entry_count = -1;
 117                 if (!*slash) {
 118                         int pos;
 119                         pos = cache_tree_subtree_pos(down->cache_tree, path, namelen);
 120                         if (0 <= pos)
 121                                 return down->cache_tree->down[pos]->cache_tree;
 122                         return NULL;
 123                 }
 124                 down = find_subtree(it, path, namelen, 0);
 125                 path = slash + 1;
 126         }
 127
 128         return NULL;
 129 }
 130
 131 static int do_invalidate_path(struct cache_tree *it, const char *path)
 132 {
 133         /* a/b/c
 134          * ==> invalidate self
 135          * ==> find "a", have it invalidate "b/c"
 136          * a
 137          * ==> invalidate self
 138          * ==> if "a" exists as a subtree, remove it.
 139          */
 140         const char *slash;
 141         int namelen;
 142         struct cache_tree_sub *down;
 143
 144 #if DEBUG_CACHE_TREE
 145         fprintf(stderr, "cache-tree invalidate <%s>\n", path);
 146 #endif
 147
 148         if (!it)
 149                 return 0;
 150         slash = strchrnul(path, '/');
 151         namelen = slash - path;
 152         it->entry_count = -1;
 153         if (!*slash) {
 154                 int pos;
 155                 pos = cache_tree_subtree_pos(it, path, namelen);
 156                 if (0 <= pos) {
 157                         cache_tree_free(&it->down[pos]->cache_tree);
 158                         free(it->down[pos]);
 159                         /* 0 1 2 3 4 5
 160                          *       ^     ^subtree_nr = 6
 161                          *       pos
 162                          * move 4 and 5 up one place (2 entries)
 163                          * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 164                          */
 165                         MOVE_ARRAY(it->down + pos, it->down + pos + 1,
 166                                    it->subtree_nr - pos - 1);
 167                         it->subtree_nr--;
 168                 }
 169                 return 1;
 170         }
 171         down = find_subtree(it, path, namelen, 0);
 172         if (down)
 173                 do_invalidate_path(down->cache_tree, slash + 1);
 174         return 1;
 175 }
 176
 177 void cache_tree_invalidate_path(struct index_state *istate, const char *path)
 178 {
 179         if (do_invalidate_path(istate->cache_tree, path))
 180                 istate->cache_changed |= CACHE_TREE_CHANGED;
 181 }
 182
 183 static int verify_cache(struct index_state *istate, int flags)
 184 {
 185         unsigned i, funny;
 186         int silent = flags & WRITE_TREE_SILENT;
 187
 188         /* Verify that the tree is merged */
 189         funny = 0;
 190         for (i = 0; i < istate->cache_nr; i++) {
 191                 const struct cache_entry *ce = istate->cache[i];
 192                 if (ce_stage(ce)) {
 193                         if (silent)
 194                                 return -1;
 195                         if (10 < ++funny) {
 196                                 fprintf(stderr, "...\n");
 197                                 break;
 198                         }
 199                         fprintf(stderr, "%s: unmerged (%s)\n",
 200                                 ce->name, oid_to_hex(&ce->oid));
 201                 }
 202         }
 203         if (funny)
 204                 return -1;
 205
 206         /* Also verify that the cache does not have path and path/file
 207          * at the same time.  At this point we know the cache has only
 208          * stage 0 entries.
 209          */
 210         funny = 0;
 211         for (i = 0; i + 1 < istate->cache_nr; i++) {
 212                 /* path/file always comes after path because of the way
 213                  * the cache is sorted.  Also path can appear only once,
 214                  * which means conflicting one would immediately follow.
 215                  */
 216                 const struct cache_entry *this_ce = istate->cache[i];
 217                 const struct cache_entry *next_ce = istate->cache[i + 1];
 218                 const char *this_name = this_ce->name;
 219                 const char *next_name = next_ce->name;
 220                 int this_len = ce_namelen(this_ce);
 221                 if (this_len < ce_namelen(next_ce) &&
 222                     next_name[this_len] == '/' &&
 223                     strncmp(this_name, next_name, this_len) == 0) {
 224                         if (10 < ++funny) {
 225                                 fprintf(stderr, "...\n");
 226                                 break;
 227                         }
 228                         fprintf(stderr, "You have both %s and %s\n",
 229                                 this_name, next_name);
 230                 }
 231         }
 232         if (funny)
 233                 return -1;
 234         return 0;
 235 }
 236
 237 static void discard_unused_subtrees(struct cache_tree *it)
 238 {
 239         struct cache_tree_sub **down = it->down;
 240         int nr = it->subtree_nr;
 241         int dst, src;
 242         for (dst = src = 0; src < nr; src++) {
 243                 struct cache_tree_sub *s = down[src];
 244                 if (s->used)
 245                         down[dst++] = s;
 246                 else {
 247                         cache_tree_free(&s->cache_tree);
 248                         free(s);
 249                         it->subtree_nr--;
 250                 }
 251         }
 252 }
 253
 254 int cache_tree_fully_valid(struct cache_tree *it)
 255 {
 256         int i;
 257         if (!it)
 258                 return 0;
 259         if (it->entry_count < 0 || !has_object_file(&it->oid))
 260                 return 0;
 261         for (i = 0; i < it->subtree_nr; i++) {
 262                 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
 263                         return 0;
 264         }
 265         return 1;
 266 }
 267
 268 static int must_check_existence(const struct cache_entry *ce)
 269 {
 270         return !(has_promisor_remote() && ce_skip_worktree(ce));
 271 }
 272
 273 static int update_one(struct cache_tree *it,
 274                       struct cache_entry **cache,
 275                       int entries,
 276                       const char *base,
 277                       int baselen,
 278                       int *skip_count,
 279                       int flags)
 280 {
 281         struct strbuf buffer;
 282         int missing_ok = flags & WRITE_TREE_MISSING_OK;
 283         int dryrun = flags & WRITE_TREE_DRY_RUN;
 284         int repair = flags & WRITE_TREE_REPAIR;
 285         int to_invalidate = 0;
 286         int i;
 287
 288         assert(!(dryrun && repair));
 289
 290         *skip_count = 0;
 291
 292         /*
 293          * If the first entry of this region is a sparse directory
 294          * entry corresponding exactly to 'base', then this cache_tree
 295          * struct is a "leaf" in the data structure, pointing to the
 296          * tree OID specified in the entry.
 297          */
 298         if (entries > 0) {
 299                 const struct cache_entry *ce = cache[0];
 300
 301                 if (S_ISSPARSEDIR(ce->ce_mode) &&
 302                     ce->ce_namelen == baselen &&
 303                     !strncmp(ce->name, base, baselen)) {
 304                         it->entry_count = 1;
 305                         oidcpy(&it->oid, &ce->oid);
 306                         return 1;
 307                 }
 308         }
 309
 310         if (0 <= it->entry_count && has_object_file(&it->oid))
 311                 return it->entry_count;
 312
 313         /*
 314          * We first scan for subtrees and update them; we start by
 315          * marking existing subtrees -- the ones that are unmarked
 316          * should not be in the result.
 317          */
 318         for (i = 0; i < it->subtree_nr; i++)
 319                 it->down[i]->used = 0;
 320
 321         /*
 322          * Find the subtrees and update them.
 323          */
 324         i = 0;
 325         while (i < entries) {
 326                 const struct cache_entry *ce = cache[i];
 327                 struct cache_tree_sub *sub;
 328                 const char *path, *slash;
 329                 int pathlen, sublen, subcnt, subskip;
 330
 331                 path = ce->name;
 332                 pathlen = ce_namelen(ce);
 333                 if (pathlen <= baselen || memcmp(base, path, baselen))
 334                         break; /* at the end of this level */
 335
 336                 slash = strchr(path + baselen, '/');
 337                 if (!slash) {
 338                         i++;
 339                         continue;
 340                 }
 341                 /*
 342                  * a/bbb/c (base = a/, slash = /c)
 343                  * ==>
 344                  * path+baselen = bbb/c, sublen = 3
 345                  */
 346                 sublen = slash - (path + baselen);
 347                 sub = find_subtree(it, path + baselen, sublen, 1);
 348                 if (!sub->cache_tree)
 349                         sub->cache_tree = cache_tree();
 350                 subcnt = update_one(sub->cache_tree,
 351                                     cache + i, entries - i,
 352                                     path,
 353                                     baselen + sublen + 1,
 354                                     &subskip,
 355                                     flags);
 356                 if (subcnt < 0)
 357                         return subcnt;
 358                 if (!subcnt)
 359                         die("index cache-tree records empty sub-tree");
 360                 i += subcnt;
 361                 sub->count = subcnt; /* to be used in the next loop */
 362                 *skip_count += subskip;
 363                 sub->used = 1;
 364         }
 365
 366         discard_unused_subtrees(it);
 367
 368         /*
 369          * Then write out the tree object for this level.
 370          */
 371         strbuf_init(&buffer, 8192);
 372
 373         i = 0;
 374         while (i < entries) {
 375                 const struct cache_entry *ce = cache[i];
 376                 struct cache_tree_sub *sub = NULL;
 377                 const char *path, *slash;
 378                 int pathlen, entlen;
 379                 const struct object_id *oid;
 380                 unsigned mode;
 381                 int expected_missing = 0;
 382                 int contains_ita = 0;
 383                 int ce_missing_ok;
 384
 385                 path = ce->name;
 386                 pathlen = ce_namelen(ce);
 387                 if (pathlen <= baselen || memcmp(base, path, baselen))
 388                         break; /* at the end of this level */
 389
 390                 slash = strchr(path + baselen, '/');
 391                 if (slash) {
 392                         entlen = slash - (path + baselen);
 393                         sub = find_subtree(it, path + baselen, entlen, 0);
 394                         if (!sub)
 395                                 die("cache-tree.c: '%.*s' in '%s' not found",
 396                                     entlen, path + baselen, path);
 397                         i += sub->count;
 398                         oid = &sub->cache_tree->oid;
 399                         mode = S_IFDIR;
 400                         contains_ita = sub->cache_tree->entry_count < 0;
 401                         if (contains_ita) {
 402                                 to_invalidate = 1;
 403                                 expected_missing = 1;
 404                         }
 405                 }
 406                 else {
 407                         oid = &ce->oid;
 408                         mode = ce->ce_mode;
 409                         entlen = pathlen - baselen;
 410                         i++;
 411                 }
 412
 413                 ce_missing_ok = mode == S_IFGITLINK || missing_ok ||
 414                         !must_check_existence(ce);
 415                 if (is_null_oid(oid) ||
 416                     (!ce_missing_ok && !has_object_file(oid))) {
 417                         strbuf_release(&buffer);
 418                         if (expected_missing)
 419                                 return -1;
 420                         return error("invalid object %06o %s for '%.*s'",
 421                                 mode, oid_to_hex(oid), entlen+baselen, path);
 422                 }
 423
 424                 /*
 425                  * CE_REMOVE entries are removed before the index is
 426                  * written to disk. Skip them to remain consistent
 427                  * with the future on-disk index.
 428                  */
 429                 if (ce->ce_flags & CE_REMOVE) {
 430                         *skip_count = *skip_count + 1;
 431                         continue;
 432                 }
 433
 434                 /*
 435                  * CE_INTENT_TO_ADD entries exist on on-disk index but
 436                  * they are not part of generated trees. Invalidate up
 437                  * to root to force cache-tree users to read elsewhere.
 438                  */
 439                 if (!sub && ce_intent_to_add(ce)) {
 440                         to_invalidate = 1;
 441                         continue;
 442                 }
 443
 444                 /*
 445                  * "sub" can be an empty tree if all subentries are i-t-a.
 446                  */
 447                 if (contains_ita && is_empty_tree_oid(oid))
 448                         continue;
 449
 450                 strbuf_grow(&buffer, entlen + 100);
 451                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
 452                 strbuf_add(&buffer, oid->hash, the_hash_algo->rawsz);
 453
 454 #if DEBUG_CACHE_TREE
 455                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
 456                         mode, entlen, path + baselen);
 457 #endif
 458         }
 459
 460         if (repair) {
 461                 struct object_id oid;
 462                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 463                                  OBJ_TREE, &oid);
 464                 if (has_object_file_with_flags(&oid, OBJECT_INFO_SKIP_FETCH_OBJECT))
 465                         oidcpy(&it->oid, &oid);
 466                 else
 467                         to_invalidate = 1;
 468         } else if (dryrun) {
 469                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 470                                  OBJ_TREE, &it->oid);
 471         } else if (write_object_file_flags(buffer.buf, buffer.len, OBJ_TREE,
 472                                            &it->oid, flags & WRITE_TREE_SILENT
 473                                            ? HASH_SILENT : 0)) {
 474                 strbuf_release(&buffer);
 475                 return -1;
 476         }
 477
 478         strbuf_release(&buffer);
 479         it->entry_count = to_invalidate ? -1 : i - *skip_count;
 480 #if DEBUG_CACHE_TREE
 481         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
 482                 it->entry_count, it->subtree_nr,
 483                 oid_to_hex(&it->oid));
 484 #endif
 485         return i;
 486 }
 487
 488 int cache_tree_update(struct index_state *istate, int flags)
 489 {
 490         int skip, i;
 491
 492         i = verify_cache(istate, flags);
 493
 494         if (i)
 495                 return i;
 496
 497         if (!istate->cache_tree)
 498                 istate->cache_tree = cache_tree();
 499
 500         if (!(flags & WRITE_TREE_MISSING_OK) && has_promisor_remote())
 501                 prefetch_cache_entries(istate, must_check_existence);
 502
 503         trace_performance_enter();
 504         trace2_region_enter("cache_tree", "update", the_repository);
 505         begin_odb_transaction();
 506         i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
 507                        "", 0, &skip, flags);
 508         end_odb_transaction();
 509         trace2_region_leave("cache_tree", "update", the_repository);
 510         trace_performance_leave("cache_tree_update");
 511         if (i < 0)
 512                 return i;
 513         istate->cache_changed |= CACHE_TREE_CHANGED;
 514         return 0;
 515 }
 516
 517 static void write_one(struct strbuf *buffer, struct cache_tree *it,
 518                       const char *path, int pathlen)
 519 {
 520         int i;
 521
 522         /* One "cache-tree" entry consists of the following:
 523          * path (NUL terminated)
 524          * entry_count, subtree_nr ("%d %d\n")
 525          * tree-sha1 (missing if invalid)
 526          * subtree_nr "cache-tree" entries for subtrees.
 527          */
 528         strbuf_grow(buffer, pathlen + 100);
 529         strbuf_add(buffer, path, pathlen);
 530         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 531
 532 #if DEBUG_CACHE_TREE
 533         if (0 <= it->entry_count)
 534                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 535                         pathlen, path, it->entry_count, it->subtree_nr,
 536                         oid_to_hex(&it->oid));
 537         else
 538                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 539                         pathlen, path, it->subtree_nr);
 540 #endif
 541
 542         if (0 <= it->entry_count) {
 543                 strbuf_add(buffer, it->oid.hash, the_hash_algo->rawsz);
 544         }
 545         for (i = 0; i < it->subtree_nr; i++) {
 546                 struct cache_tree_sub *down = it->down[i];
 547                 if (i) {
 548                         struct cache_tree_sub *prev = it->down[i-1];
 549                         if (subtree_name_cmp(down->name, down->namelen,
 550                                              prev->name, prev->namelen) <= 0)
 551                                 die("fatal - unsorted cache subtree");
 552                 }
 553                 write_one(buffer, down->cache_tree, down->name, down->namelen);
 554         }
 555 }
 556
 557 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
 558 {
 559         trace2_region_enter("cache_tree", "write", the_repository);
 560         write_one(sb, root, "", 0);
 561         trace2_region_leave("cache_tree", "write", the_repository);
 562 }
 563
 564 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 565 {
 566         const char *buf = *buffer;
 567         unsigned long size = *size_p;
 568         const char *cp;
 569         char *ep;
 570         struct cache_tree *it;
 571         int i, subtree_nr;
 572         const unsigned rawsz = the_hash_algo->rawsz;
 573
 574         it = NULL;
 575         /* skip name, but make sure name exists */
 576         while (size && *buf) {
 577                 size--;
 578                 buf++;
 579         }
 580         if (!size)
 581                 goto free_return;
 582         buf++; size--;
 583         it = cache_tree();
 584
 585         cp = buf;
 586         it->entry_count = strtol(cp, &ep, 10);
 587         if (cp == ep)
 588                 goto free_return;
 589         cp = ep;
 590         subtree_nr = strtol(cp, &ep, 10);
 591         if (cp == ep)
 592                 goto free_return;
 593         while (size && *buf && *buf != '\n') {
 594                 size--;
 595                 buf++;
 596         }
 597         if (!size)
 598                 goto free_return;
 599         buf++; size--;
 600         if (0 <= it->entry_count) {
 601                 if (size < rawsz)
 602                         goto free_return;
 603                 oidread(&it->oid, (const unsigned char *)buf);
 604                 buf += rawsz;
 605                 size -= rawsz;
 606         }
 607
 608 #if DEBUG_CACHE_TREE
 609         if (0 <= it->entry_count)
 610                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 611                         *buffer, it->entry_count, subtree_nr,
 612                         oid_to_hex(&it->oid));
 613         else
 614                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 615                         *buffer, subtree_nr);
 616 #endif
 617
 618         /*
 619          * Just a heuristic -- we do not add directories that often but
 620          * we do not want to have to extend it immediately when we do,
 621          * hence +2.
 622          */
 623         it->subtree_alloc = subtree_nr + 2;
 624         CALLOC_ARRAY(it->down, it->subtree_alloc);
 625         for (i = 0; i < subtree_nr; i++) {
 626                 /* read each subtree */
 627                 struct cache_tree *sub;
 628                 struct cache_tree_sub *subtree;
 629                 const char *name = buf;
 630
 631                 sub = read_one(&buf, &size);
 632                 if (!sub)
 633                         goto free_return;
 634                 subtree = cache_tree_sub(it, name);
 635                 subtree->cache_tree = sub;
 636         }
 637         if (subtree_nr != it->subtree_nr)
 638                 die("cache-tree: internal error");
 639         *buffer = buf;
 640         *size_p = size;
 641         return it;
 642
 643  free_return:
 644         cache_tree_free(&it);
 645         return NULL;
 646 }
 647
 648 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 649 {
 650         struct cache_tree *result;
 651
 652         if (buffer[0])
 653                 return NULL; /* not the whole tree */
 654
 655         trace2_region_enter("cache_tree", "read", the_repository);
 656         result = read_one(&buffer, &size);
 657         trace2_region_leave("cache_tree", "read", the_repository);
 658
 659         return result;
 660 }
 661
 662 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 663 {
 664         if (!it)
 665                 return NULL;
 666         while (*path) {
 667                 const char *slash;
 668                 struct cache_tree_sub *sub;
 669
 670                 slash = strchrnul(path, '/');
 671                 /*
 672                  * Between path and slash is the name of the subtree
 673                  * to look for.
 674                  */
 675                 sub = find_subtree(it, path, slash - path, 0);
 676                 if (!sub)
 677                         return NULL;
 678                 it = sub->cache_tree;
 679
 680                 path = slash;
 681                 while (*path == '/')
 682                         path++;
 683         }
 684         return it;
 685 }
 686
 687 static int write_index_as_tree_internal(struct object_id *oid,
 688                                         struct index_state *index_state,
 689                                         int cache_tree_valid,
 690                                         int flags,
 691                                         const char *prefix)
 692 {
 693         if (flags & WRITE_TREE_IGNORE_CACHE_TREE) {
 694                 cache_tree_free(&index_state->cache_tree);
 695                 cache_tree_valid = 0;
 696         }
 697
 698         if (!cache_tree_valid && cache_tree_update(index_state, flags) < 0)
 699                 return WRITE_TREE_UNMERGED_INDEX;
 700
 701         if (prefix) {
 702                 struct cache_tree *subtree;
 703                 subtree = cache_tree_find(index_state->cache_tree, prefix);
 704                 if (!subtree)
 705                         return WRITE_TREE_PREFIX_ERROR;
 706                 oidcpy(oid, &subtree->oid);
 707         }
 708         else
 709                 oidcpy(oid, &index_state->cache_tree->oid);
 710
 711         return 0;
 712 }
 713
 714 struct tree* write_in_core_index_as_tree(struct repository *repo) {
 715         struct object_id o;
 716         int was_valid, ret;
 717
 718         struct index_state *index_state = repo->index;
 719         was_valid = index_state->cache_tree &&
 720                     cache_tree_fully_valid(index_state->cache_tree);
 721
 722         ret = write_index_as_tree_internal(&o, index_state, was_valid, 0, NULL);
 723         if (ret == WRITE_TREE_UNMERGED_INDEX) {
 724                 int i;
 725                 bug("there are unmerged index entries:");
 726                 for (i = 0; i < index_state->cache_nr; i++) {
 727                         const struct cache_entry *ce = index_state->cache[i];
 728                         if (ce_stage(ce))
 729                                 bug("%d %.*s", ce_stage(ce),
 730                                     (int)ce_namelen(ce), ce->name);
 731                 }
 732                 BUG("unmerged index entries when writing in-core index");
 733         }
 734
 735         return lookup_tree(repo, &index_state->cache_tree->oid);
 736 }
 737
 738
 739 int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix)
 740 {
 741         int entries, was_valid;
 742         struct lock_file lock_file = LOCK_INIT;
 743         int ret;
 744
 745         hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
 746
 747         entries = read_index_from(index_state, index_path, get_git_dir());
 748         if (entries < 0) {
 749                 ret = WRITE_TREE_UNREADABLE_INDEX;
 750                 goto out;
 751         }
 752
 753         was_valid = !(flags & WRITE_TREE_IGNORE_CACHE_TREE) &&
 754                     index_state->cache_tree &&
 755                     cache_tree_fully_valid(index_state->cache_tree);
 756
 757         ret = write_index_as_tree_internal(oid, index_state, was_valid, flags,
 758                                            prefix);
 759         if (!ret && !was_valid) {
 760                 write_locked_index(index_state, &lock_file, COMMIT_LOCK);
 761                 /* Not being able to write is fine -- we are only interested
 762                  * in updating the cache-tree part, and if the next caller
 763                  * ends up using the old index with unupdated cache-tree part
 764                  * it misses the work we did here, but that is just a
 765                  * performance penalty and not a big deal.
 766                  */
 767         }
 768
 769 out:
 770         rollback_lock_file(&lock_file);
 771         return ret;
 772 }
 773
 774 static void prime_cache_tree_sparse_dir(struct cache_tree *it,
 775                                         struct tree *tree)
 776 {
 777
 778         oidcpy(&it->oid, &tree->object.oid);
 779         it->entry_count = 1;
 780 }
 781
 782 static void prime_cache_tree_rec(struct repository *r,
 783                                  struct cache_tree *it,
 784                                  struct tree *tree,
 785                                  struct strbuf *tree_path)
 786 {
 787         struct tree_desc desc;
 788         struct name_entry entry;
 789         int cnt;
 790         int base_path_len = tree_path->len;
 791
 792         oidcpy(&it->oid, &tree->object.oid);
 793
 794         init_tree_desc(&desc, tree->buffer, tree->size);
 795         cnt = 0;
 796         while (tree_entry(&desc, &entry)) {
 797                 if (!S_ISDIR(entry.mode))
 798                         cnt++;
 799                 else {
 800                         struct cache_tree_sub *sub;
 801                         struct tree *subtree = lookup_tree(r, &entry.oid);
 802
 803                         if (!subtree->object.parsed)
 804                                 parse_tree(subtree);
 805                         sub = cache_tree_sub(it, entry.path);
 806                         sub->cache_tree = cache_tree();
 807
 808                         /*
 809                          * Recursively-constructed subtree path is only needed when working
 810                          * in a sparse index (where it's used to determine whether the
 811                          * subtree is a sparse directory in the index).
 812                          */
 813                         if (r->index->sparse_index) {
 814                                 strbuf_setlen(tree_path, base_path_len);
 815                                 strbuf_grow(tree_path, base_path_len + entry.pathlen + 1);
 816                                 strbuf_add(tree_path, entry.path, entry.pathlen);
 817                                 strbuf_addch(tree_path, '/');
 818                         }
 819
 820                         /*
 821                          * If a sparse index is in use, the directory being processed may be
 822                          * sparse. To confirm that, we can check whether an entry with that
 823                          * exact name exists in the index. If it does, the created subtree
 824                          * should be sparse. Otherwise, cache tree expansion should continue
 825                          * as normal.
 826                          */
 827                         if (r->index->sparse_index &&
 828                             index_entry_exists(r->index, tree_path->buf, tree_path->len))
 829                                 prime_cache_tree_sparse_dir(sub->cache_tree, subtree);
 830                         else
 831                                 prime_cache_tree_rec(r, sub->cache_tree, subtree, tree_path);
 832                         cnt += sub->cache_tree->entry_count;
 833                 }
 834         }
 835
 836         it->entry_count = cnt;
 837 }
 838
 839 void prime_cache_tree(struct repository *r,
 840                       struct index_state *istate,
 841                       struct tree *tree)
 842 {
 843         struct strbuf tree_path = STRBUF_INIT;
 844
 845         trace2_region_enter("cache-tree", "prime_cache_tree", the_repository);
 846         cache_tree_free(&istate->cache_tree);
 847         istate->cache_tree = cache_tree();
 848
 849         prime_cache_tree_rec(r, istate->cache_tree, tree, &tree_path);
 850         strbuf_release(&tree_path);
 851         istate->cache_changed |= CACHE_TREE_CHANGED;
 852         trace2_region_leave("cache-tree", "prime_cache_tree", the_repository);
 853 }
 854
 855 /*
 856  * find the cache_tree that corresponds to the current level without
 857  * exploding the full path into textual form.  The root of the
 858  * cache tree is given as "root", and our current level is "info".
 859  * (1) When at root level, info->prev is NULL, so it is "root" itself.
 860  * (2) Otherwise, find the cache_tree that corresponds to one level
 861  *     above us, and find ourselves in there.
 862  */
 863 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
 864                                                          struct traverse_info *info)
 865 {
 866         struct cache_tree *our_parent;
 867
 868         if (!info->prev)
 869                 return root;
 870         our_parent = find_cache_tree_from_traversal(root, info->prev);
 871         return cache_tree_find(our_parent, info->name);
 872 }
 873
 874 int cache_tree_matches_traversal(struct cache_tree *root,
 875                                  struct name_entry *ent,
 876                                  struct traverse_info *info)
 877 {
 878         struct cache_tree *it;
 879
 880         it = find_cache_tree_from_traversal(root, info);
 881         it = cache_tree_find(it, ent->path);
 882         if (it && it->entry_count > 0 && oideq(&ent->oid, &it->oid))
 883                 return it->entry_count;
 884         return 0;
 885 }
 886
 887 static void verify_one_sparse(struct repository *r,
 888                               struct index_state *istate,
 889                               struct cache_tree *it,
 890                               struct strbuf *path,
 891                               int pos)
 892 {
 893         struct cache_entry *ce = istate->cache[pos];
 894
 895         if (!S_ISSPARSEDIR(ce->ce_mode))
 896                 BUG("directory '%s' is present in index, but not sparse",
 897                     path->buf);
 898 }
 899
 900 /*
 901  * Returns:
 902  *  0 - Verification completed.
 903  *  1 - Restart verification - a call to ensure_full_index() freed the cache
 904  *      tree that is being verified and verification needs to be restarted from
 905  *      the new toplevel cache tree.
 906  */
 907 static int verify_one(struct repository *r,
 908                       struct index_state *istate,
 909                       struct cache_tree *it,
 910                       struct strbuf *path)
 911 {
 912         int i, pos, len = path->len;
 913         struct strbuf tree_buf = STRBUF_INIT;
 914         struct object_id new_oid;
 915
 916         for (i = 0; i < it->subtree_nr; i++) {
 917                 strbuf_addf(path, "%s/", it->down[i]->name);
 918                 if (verify_one(r, istate, it->down[i]->cache_tree, path))
 919                         return 1;
 920                 strbuf_setlen(path, len);
 921         }
 922
 923         if (it->entry_count < 0 ||
 924             /* no verification on tests (t7003) that replace trees */
 925             lookup_replace_object(r, &it->oid) != &it->oid)
 926                 return 0;
 927
 928         if (path->len) {
 929                 /*
 930                  * If the index is sparse and the cache tree is not
 931                  * index_name_pos() may trigger ensure_full_index() which will
 932                  * free the tree that is being verified.
 933                  */
 934                 int is_sparse = istate->sparse_index;
 935                 pos = index_name_pos(istate, path->buf, path->len);
 936                 if (is_sparse && !istate->sparse_index)
 937                         return 1;
 938
 939                 if (pos >= 0) {
 940                         verify_one_sparse(r, istate, it, path, pos);
 941                         return 0;
 942                 }
 943
 944                 pos = -pos - 1;
 945         } else {
 946                 pos = 0;
 947         }
 948
 949         i = 0;
 950         while (i < it->entry_count) {
 951                 struct cache_entry *ce = istate->cache[pos + i];
 952                 const char *slash;
 953                 struct cache_tree_sub *sub = NULL;
 954                 const struct object_id *oid;
 955                 const char *name;
 956                 unsigned mode;
 957                 int entlen;
 958
 959                 if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE))
 960                         BUG("%s with flags 0x%x should not be in cache-tree",
 961                             ce->name, ce->ce_flags);
 962                 name = ce->name + path->len;
 963                 slash = strchr(name, '/');
 964                 if (slash) {
 965                         entlen = slash - name;
 966                         sub = find_subtree(it, ce->name + path->len, entlen, 0);
 967                         if (!sub || sub->cache_tree->entry_count < 0)
 968                                 BUG("bad subtree '%.*s'", entlen, name);
 969                         oid = &sub->cache_tree->oid;
 970                         mode = S_IFDIR;
 971                         i += sub->cache_tree->entry_count;
 972                 } else {
 973                         oid = &ce->oid;
 974                         mode = ce->ce_mode;
 975                         entlen = ce_namelen(ce) - path->len;
 976                         i++;
 977                 }
 978                 strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0');
 979                 strbuf_add(&tree_buf, oid->hash, r->hash_algo->rawsz);
 980         }
 981         hash_object_file(r->hash_algo, tree_buf.buf, tree_buf.len, OBJ_TREE,
 982                          &new_oid);
 983         if (!oideq(&new_oid, &it->oid))
 984                 BUG("cache-tree for path %.*s does not match. "
 985                     "Expected %s got %s", len, path->buf,
 986                     oid_to_hex(&new_oid), oid_to_hex(&it->oid));
 987         strbuf_setlen(path, len);
 988         strbuf_release(&tree_buf);
 989         return 0;
 990 }
 991
 992 void cache_tree_verify(struct repository *r, struct index_state *istate)
 993 {
 994         struct strbuf path = STRBUF_INIT;
 995
 996         if (!istate->cache_tree)
 997                 return;
 998         if (verify_one(r, istate, istate->cache_tree, &path)) {
 999                 strbuf_reset(&path);
1000                 if (verify_one(r, istate, istate->cache_tree, &path))
1001                         BUG("ensure_full_index() called twice while verifying cache tree");
1002         }
1003         strbuf_release(&path);
1004 }