cache-tree.con commit general improvements (43abf13)
   1#include "cache.h"
   2#include "lockfile.h"
   3#include "tree.h"
   4#include "tree-walk.h"
   5#include "cache-tree.h"
   6#include "object-store.h"
   7#include "replace-object.h"
   8#include "promisor-remote.h"
   9
  10#ifndef DEBUG_CACHE_TREE
  11#define DEBUG_CACHE_TREE 0
  12#endif
  13
  14struct cache_tree *cache_tree(void)
  15{
  16        struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  17        it->entry_count = -1;
  18        return it;
  19}
  20
  21void cache_tree_free(struct cache_tree **it_p)
  22{
  23        int i;
  24        struct cache_tree *it = *it_p;
  25
  26        if (!it)
  27                return;
  28        for (i = 0; i < it->subtree_nr; i++)
  29                if (it->down[i]) {
  30                        cache_tree_free(&it->down[i]->cache_tree);
  31                        free(it->down[i]);
  32                }
  33        free(it->down);
  34        free(it);
  35        *it_p = NULL;
  36}
  37
  38static int subtree_name_cmp(const char *one, int onelen,
  39                            const char *two, int twolen)
  40{
  41        if (onelen < twolen)
  42                return -1;
  43        if (twolen < onelen)
  44                return 1;
  45        return memcmp(one, two, onelen);
  46}
  47
  48static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  49{
  50        struct cache_tree_sub **down = it->down;
  51        int lo, hi;
  52        lo = 0;
  53        hi = it->subtree_nr;
  54        while (lo < hi) {
  55                int mi = lo + (hi - lo) / 2;
  56                struct cache_tree_sub *mdl = down[mi];
  57                int cmp = subtree_name_cmp(path, pathlen,
  58                                           mdl->name, mdl->namelen);
  59                if (!cmp)
  60                        return mi;
  61                if (cmp < 0)
  62                        hi = mi;
  63                else
  64                        lo = mi + 1;
  65        }
  66        return -lo-1;
  67}
  68
  69static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  70                                           const char *path,
  71                                           int pathlen,
  72                                           int create)
  73{
  74        struct cache_tree_sub *down;
  75        int pos = subtree_pos(it, path, pathlen);
  76        if (0 <= pos)
  77                return it->down[pos];
  78        if (!create)
  79                return NULL;
  80
  81        pos = -pos-1;
  82        ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
  83        it->subtree_nr++;
  84
  85        FLEX_ALLOC_MEM(down, name, path, pathlen);
  86        down->cache_tree = NULL;
  87        down->namelen = pathlen;
  88
  89        if (pos < it->subtree_nr)
  90                MOVE_ARRAY(it->down + pos + 1, it->down + pos,
  91                           it->subtree_nr - pos - 1);
  92        it->down[pos] = down;
  93        return down;
  94}
  95
  96struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
  97{
  98        int pathlen = strlen(path);
  99        return find_subtree(it, path, pathlen, 1);
 100}
 101
 102static int do_invalidate_path(struct cache_tree *it, const char *path)
 103{
 104        /* a/b/c
 105         * ==> invalidate self
 106         * ==> find "a", have it invalidate "b/c"
 107         * a
 108         * ==> invalidate self
 109         * ==> if "a" exists as a subtree, remove it.
 110         */
 111        const char *slash;
 112        int namelen;
 113        struct cache_tree_sub *down;
 114
 115#if DEBUG_CACHE_TREE
 116        fprintf(stderr, "cache-tree invalidate <%s>\n", path);
 117#endif
 118
 119        if (!it)
 120                return 0;
 121        slash = strchrnul(path, '/');
 122        namelen = slash - path;
 123        it->entry_count = -1;
 124        if (!*slash) {
 125                int pos;
 126                pos = subtree_pos(it, path, namelen);
 127                if (0 <= pos) {
 128                        cache_tree_free(&it->down[pos]->cache_tree);
 129                        free(it->down[pos]);
 130                        /* 0 1 2 3 4 5
 131                         *       ^     ^subtree_nr = 6
 132                         *       pos
 133                         * move 4 and 5 up one place (2 entries)
 134                         * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 135                         */
 136                        MOVE_ARRAY(it->down + pos, it->down + pos + 1,
 137                                   it->subtree_nr - pos - 1);
 138                        it->subtree_nr--;
 139                }
 140                return 1;
 141        }
 142        down = find_subtree(it, path, namelen, 0);
 143        if (down)
 144                do_invalidate_path(down->cache_tree, slash + 1);
 145        return 1;
 146}
 147
 148void cache_tree_invalidate_path(struct index_state *istate, const char *path)
 149{
 150        if (do_invalidate_path(istate->cache_tree, path))
 151                istate->cache_changed |= CACHE_TREE_CHANGED;
 152}
 153
 154static int verify_cache(struct cache_entry **cache,
 155                        int entries, int flags)
 156{
 157        int i, funny;
 158        int silent = flags & WRITE_TREE_SILENT;
 159
 160        /* Verify that the tree is merged */
 161        funny = 0;
 162        for (i = 0; i < entries; i++) {
 163                const struct cache_entry *ce = cache[i];
 164                if (ce_stage(ce)) {
 165                        if (silent)
 166                                return -1;
 167                        if (10 < ++funny) {
 168                                fprintf(stderr, "...\n");
 169                                break;
 170                        }
 171                        fprintf(stderr, "%s: unmerged (%s)\n",
 172                                ce->name, oid_to_hex(&ce->oid));
 173                }
 174        }
 175        if (funny)
 176                return -1;
 177
 178        /* Also verify that the cache does not have path and path/file
 179         * at the same time.  At this point we know the cache has only
 180         * stage 0 entries.
 181         */
 182        funny = 0;
 183        for (i = 0; i < entries - 1; i++) {
 184                /* path/file always comes after path because of the way
 185                 * the cache is sorted.  Also path can appear only once,
 186                 * which means conflicting one would immediately follow.
 187                 */
 188                const char *this_name = cache[i]->name;
 189                const char *next_name = cache[i+1]->name;
 190                int this_len = strlen(this_name);
 191                if (this_len < strlen(next_name) &&
 192                    strncmp(this_name, next_name, this_len) == 0 &&
 193                    next_name[this_len] == '/') {
 194                        if (10 < ++funny) {
 195                                fprintf(stderr, "...\n");
 196                                break;
 197                        }
 198                        fprintf(stderr, "You have both %s and %s\n",
 199                                this_name, next_name);
 200                }
 201        }
 202        if (funny)
 203                return -1;
 204        return 0;
 205}
 206
 207static void discard_unused_subtrees(struct cache_tree *it)
 208{
 209        struct cache_tree_sub **down = it->down;
 210        int nr = it->subtree_nr;
 211        int dst, src;
 212        for (dst = src = 0; src < nr; src++) {
 213                struct cache_tree_sub *s = down[src];
 214                if (s->used)
 215                        down[dst++] = s;
 216                else {
 217                        cache_tree_free(&s->cache_tree);
 218                        free(s);
 219                        it->subtree_nr--;
 220                }
 221        }
 222}
 223
 224int cache_tree_fully_valid(struct cache_tree *it)
 225{
 226        int i;
 227        if (!it)
 228                return 0;
 229        if (it->entry_count < 0 || !has_object_file(&it->oid))
 230                return 0;
 231        for (i = 0; i < it->subtree_nr; i++) {
 232                if (!cache_tree_fully_valid(it->down[i]->cache_tree))
 233                        return 0;
 234        }
 235        return 1;
 236}
 237
 238static int update_one(struct cache_tree *it,
 239                      struct cache_entry **cache,
 240                      int entries,
 241                      const char *base,
 242                      int baselen,
 243                      int *skip_count,
 244                      int flags)
 245{
 246        struct strbuf buffer;
 247        int missing_ok = flags & WRITE_TREE_MISSING_OK;
 248        int dryrun = flags & WRITE_TREE_DRY_RUN;
 249        int repair = flags & WRITE_TREE_REPAIR;
 250        int to_invalidate = 0;
 251        int i;
 252
 253        assert(!(dryrun && repair));
 254
 255        *skip_count = 0;
 256
 257        if (0 <= it->entry_count && has_object_file(&it->oid))
 258                return it->entry_count;
 259
 260        /*
 261         * We first scan for subtrees and update them; we start by
 262         * marking existing subtrees -- the ones that are unmarked
 263         * should not be in the result.
 264         */
 265        for (i = 0; i < it->subtree_nr; i++)
 266                it->down[i]->used = 0;
 267
 268        /*
 269         * Find the subtrees and update them.
 270         */
 271        i = 0;
 272        while (i < entries) {
 273                const struct cache_entry *ce = cache[i];
 274                struct cache_tree_sub *sub;
 275                const char *path, *slash;
 276                int pathlen, sublen, subcnt, subskip;
 277
 278                path = ce->name;
 279                pathlen = ce_namelen(ce);
 280                if (pathlen <= baselen || memcmp(base, path, baselen))
 281                        break; /* at the end of this level */
 282
 283                slash = strchr(path + baselen, '/');
 284                if (!slash) {
 285                        i++;
 286                        continue;
 287                }
 288                /*
 289                 * a/bbb/c (base = a/, slash = /c)
 290                 * ==>
 291                 * path+baselen = bbb/c, sublen = 3
 292                 */
 293                sublen = slash - (path + baselen);
 294                sub = find_subtree(it, path + baselen, sublen, 1);
 295                if (!sub->cache_tree)
 296                        sub->cache_tree = cache_tree();
 297                subcnt = update_one(sub->cache_tree,
 298                                    cache + i, entries - i,
 299                                    path,
 300                                    baselen + sublen + 1,
 301                                    &subskip,
 302                                    flags);
 303                if (subcnt < 0)
 304                        return subcnt;
 305                if (!subcnt)
 306                        die("index cache-tree records empty sub-tree");
 307                i += subcnt;
 308                sub->count = subcnt; /* to be used in the next loop */
 309                *skip_count += subskip;
 310                sub->used = 1;
 311        }
 312
 313        discard_unused_subtrees(it);
 314
 315        /*
 316         * Then write out the tree object for this level.
 317         */
 318        strbuf_init(&buffer, 8192);
 319
 320        i = 0;
 321        while (i < entries) {
 322                const struct cache_entry *ce = cache[i];
 323                struct cache_tree_sub *sub = NULL;
 324                const char *path, *slash;
 325                int pathlen, entlen;
 326                const struct object_id *oid;
 327                unsigned mode;
 328                int expected_missing = 0;
 329                int contains_ita = 0;
 330                int ce_missing_ok;
 331
 332                path = ce->name;
 333                pathlen = ce_namelen(ce);
 334                if (pathlen <= baselen || memcmp(base, path, baselen))
 335                        break; /* at the end of this level */
 336
 337                slash = strchr(path + baselen, '/');
 338                if (slash) {
 339                        entlen = slash - (path + baselen);
 340                        sub = find_subtree(it, path + baselen, entlen, 0);
 341                        if (!sub)
 342                                die("cache-tree.c: '%.*s' in '%s' not found",
 343                                    entlen, path + baselen, path);
 344                        i += sub->count;
 345                        oid = &sub->cache_tree->oid;
 346                        mode = S_IFDIR;
 347                        contains_ita = sub->cache_tree->entry_count < 0;
 348                        if (contains_ita) {
 349                                to_invalidate = 1;
 350                                expected_missing = 1;
 351                        }
 352                }
 353                else {
 354                        oid = &ce->oid;
 355                        mode = ce->ce_mode;
 356                        entlen = pathlen - baselen;
 357                        i++;
 358                }
 359
 360                ce_missing_ok = mode == S_IFGITLINK || missing_ok ||
 361                        (has_promisor_remote() &&
 362                         ce_skip_worktree(ce));
 363                if (is_null_oid(oid) ||
 364                    (!ce_missing_ok && !has_object_file(oid))) {
 365                        strbuf_release(&buffer);
 366                        if (expected_missing)
 367                                return -1;
 368                        return error("invalid object %06o %s for '%.*s'",
 369                                mode, oid_to_hex(oid), entlen+baselen, path);
 370                }
 371
 372                /*
 373                 * CE_REMOVE entries are removed before the index is
 374                 * written to disk. Skip them to remain consistent
 375                 * with the future on-disk index.
 376                 */
 377                if (ce->ce_flags & CE_REMOVE) {
 378                        *skip_count = *skip_count + 1;
 379                        continue;
 380                }
 381
 382                /*
 383                 * CE_INTENT_TO_ADD entries exist on on-disk index but
 384                 * they are not part of generated trees. Invalidate up
 385                 * to root to force cache-tree users to read elsewhere.
 386                 */
 387                if (!sub && ce_intent_to_add(ce)) {
 388                        to_invalidate = 1;
 389                        continue;
 390                }
 391
 392                /*
 393                 * "sub" can be an empty tree if all subentries are i-t-a.
 394                 */
 395                if (contains_ita && is_empty_tree_oid(oid))
 396                        continue;
 397
 398                strbuf_grow(&buffer, entlen + 100);
 399                strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
 400                strbuf_add(&buffer, oid->hash, the_hash_algo->rawsz);
 401
 402#if DEBUG_CACHE_TREE
 403                fprintf(stderr, "cache-tree update-one %o %.*s\n",
 404                        mode, entlen, path + baselen);
 405#endif
 406        }
 407
 408        if (repair) {
 409                struct object_id oid;
 410                hash_object_file(buffer.buf, buffer.len, tree_type, &oid);
 411                if (has_object_file(&oid))
 412                        oidcpy(&it->oid, &oid);
 413                else
 414                        to_invalidate = 1;
 415        } else if (dryrun) {
 416                hash_object_file(buffer.buf, buffer.len, tree_type, &it->oid);
 417        } else if (write_object_file(buffer.buf, buffer.len, tree_type,
 418                                     &it->oid)) {
 419                strbuf_release(&buffer);
 420                return -1;
 421        }
 422
 423        strbuf_release(&buffer);
 424        it->entry_count = to_invalidate ? -1 : i - *skip_count;
 425#if DEBUG_CACHE_TREE
 426        fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
 427                it->entry_count, it->subtree_nr,
 428                oid_to_hex(&it->oid));
 429#endif
 430        return i;
 431}
 432
 433int cache_tree_update(struct index_state *istate, int flags)
 434{
 435        struct cache_tree *it = istate->cache_tree;
 436        struct cache_entry **cache = istate->cache;
 437        int entries = istate->cache_nr;
 438        int skip, i = verify_cache(cache, entries, flags);
 439
 440        if (i)
 441                return i;
 442        trace_performance_enter();
 443        i = update_one(it, cache, entries, "", 0, &skip, flags);
 444        trace_performance_leave("cache_tree_update");
 445        if (i < 0)
 446                return i;
 447        istate->cache_changed |= CACHE_TREE_CHANGED;
 448        return 0;
 449}
 450
 451static void write_one(struct strbuf *buffer, struct cache_tree *it,
 452                      const char *path, int pathlen)
 453{
 454        int i;
 455
 456        /* One "cache-tree" entry consists of the following:
 457         * path (NUL terminated)
 458         * entry_count, subtree_nr ("%d %d\n")
 459         * tree-sha1 (missing if invalid)
 460         * subtree_nr "cache-tree" entries for subtrees.
 461         */
 462        strbuf_grow(buffer, pathlen + 100);
 463        strbuf_add(buffer, path, pathlen);
 464        strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 465
 466#if DEBUG_CACHE_TREE
 467        if (0 <= it->entry_count)
 468                fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 469                        pathlen, path, it->entry_count, it->subtree_nr,
 470                        oid_to_hex(&it->oid));
 471        else
 472                fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 473                        pathlen, path, it->subtree_nr);
 474#endif
 475
 476        if (0 <= it->entry_count) {
 477                strbuf_add(buffer, it->oid.hash, the_hash_algo->rawsz);
 478        }
 479        for (i = 0; i < it->subtree_nr; i++) {
 480                struct cache_tree_sub *down = it->down[i];
 481                if (i) {
 482                        struct cache_tree_sub *prev = it->down[i-1];
 483                        if (subtree_name_cmp(down->name, down->namelen,
 484                                             prev->name, prev->namelen) <= 0)
 485                                die("fatal - unsorted cache subtree");
 486                }
 487                write_one(buffer, down->cache_tree, down->name, down->namelen);
 488        }
 489}
 490
 491void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
 492{
 493        write_one(sb, root, "", 0);
 494}
 495
 496static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 497{
 498        const char *buf = *buffer;
 499        unsigned long size = *size_p;
 500        const char *cp;
 501        char *ep;
 502        struct cache_tree *it;
 503        int i, subtree_nr;
 504        const unsigned rawsz = the_hash_algo->rawsz;
 505
 506        it = NULL;
 507        /* skip name, but make sure name exists */
 508        while (size && *buf) {
 509                size--;
 510                buf++;
 511        }
 512        if (!size)
 513                goto free_return;
 514        buf++; size--;
 515        it = cache_tree();
 516
 517        cp = buf;
 518        it->entry_count = strtol(cp, &ep, 10);
 519        if (cp == ep)
 520                goto free_return;
 521        cp = ep;
 522        subtree_nr = strtol(cp, &ep, 10);
 523        if (cp == ep)
 524                goto free_return;
 525        while (size && *buf && *buf != '\n') {
 526                size--;
 527                buf++;
 528        }
 529        if (!size)
 530                goto free_return;
 531        buf++; size--;
 532        if (0 <= it->entry_count) {
 533                if (size < rawsz)
 534                        goto free_return;
 535                oidread(&it->oid, (const unsigned char *)buf);
 536                buf += rawsz;
 537                size -= rawsz;
 538        }
 539
 540#if DEBUG_CACHE_TREE
 541        if (0 <= it->entry_count)
 542                fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 543                        *buffer, it->entry_count, subtree_nr,
 544                        oid_to_hex(&it->oid));
 545        else
 546                fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 547                        *buffer, subtree_nr);
 548#endif
 549
 550        /*
 551         * Just a heuristic -- we do not add directories that often but
 552         * we do not want to have to extend it immediately when we do,
 553         * hence +2.
 554         */
 555        it->subtree_alloc = subtree_nr + 2;
 556        it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
 557        for (i = 0; i < subtree_nr; i++) {
 558                /* read each subtree */
 559                struct cache_tree *sub;
 560                struct cache_tree_sub *subtree;
 561                const char *name = buf;
 562
 563                sub = read_one(&buf, &size);
 564                if (!sub)
 565                        goto free_return;
 566                subtree = cache_tree_sub(it, name);
 567                subtree->cache_tree = sub;
 568        }
 569        if (subtree_nr != it->subtree_nr)
 570                die("cache-tree: internal error");
 571        *buffer = buf;
 572        *size_p = size;
 573        return it;
 574
 575 free_return:
 576        cache_tree_free(&it);
 577        return NULL;
 578}
 579
 580struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 581{
 582        if (buffer[0])
 583                return NULL; /* not the whole tree */
 584        return read_one(&buffer, &size);
 585}
 586
 587static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 588{
 589        if (!it)
 590                return NULL;
 591        while (*path) {
 592                const char *slash;
 593                struct cache_tree_sub *sub;
 594
 595                slash = strchrnul(path, '/');
 596                /*
 597                 * Between path and slash is the name of the subtree
 598                 * to look for.
 599                 */
 600                sub = find_subtree(it, path, slash - path, 0);
 601                if (!sub)
 602                        return NULL;
 603                it = sub->cache_tree;
 604
 605                path = slash;
 606                while (*path == '/')
 607                        path++;
 608        }
 609        return it;
 610}
 611
 612int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix)
 613{
 614        int entries, was_valid;
 615        struct lock_file lock_file = LOCK_INIT;
 616        int ret = 0;
 617
 618        hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
 619
 620        entries = read_index_from(index_state, index_path, get_git_dir());
 621        if (entries < 0) {
 622                ret = WRITE_TREE_UNREADABLE_INDEX;
 623                goto out;
 624        }
 625        if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
 626                cache_tree_free(&index_state->cache_tree);
 627
 628        if (!index_state->cache_tree)
 629                index_state->cache_tree = cache_tree();
 630
 631        was_valid = cache_tree_fully_valid(index_state->cache_tree);
 632        if (!was_valid) {
 633                if (cache_tree_update(index_state, flags) < 0) {
 634                        ret = WRITE_TREE_UNMERGED_INDEX;
 635                        goto out;
 636                }
 637                write_locked_index(index_state, &lock_file, COMMIT_LOCK);
 638                /* Not being able to write is fine -- we are only interested
 639                 * in updating the cache-tree part, and if the next caller
 640                 * ends up using the old index with unupdated cache-tree part
 641                 * it misses the work we did here, but that is just a
 642                 * performance penalty and not a big deal.
 643                 */
 644        }
 645
 646        if (prefix) {
 647                struct cache_tree *subtree;
 648                subtree = cache_tree_find(index_state->cache_tree, prefix);
 649                if (!subtree) {
 650                        ret = WRITE_TREE_PREFIX_ERROR;
 651                        goto out;
 652                }
 653                oidcpy(oid, &subtree->oid);
 654        }
 655        else
 656                oidcpy(oid, &index_state->cache_tree->oid);
 657
 658out:
 659        rollback_lock_file(&lock_file);
 660        return ret;
 661}
 662
 663static void prime_cache_tree_rec(struct repository *r,
 664                                 struct cache_tree *it,
 665                                 struct tree *tree)
 666{
 667        struct tree_desc desc;
 668        struct name_entry entry;
 669        int cnt;
 670
 671        oidcpy(&it->oid, &tree->object.oid);
 672        init_tree_desc(&desc, tree->buffer, tree->size);
 673        cnt = 0;
 674        while (tree_entry(&desc, &entry)) {
 675                if (!S_ISDIR(entry.mode))
 676                        cnt++;
 677                else {
 678                        struct cache_tree_sub *sub;
 679                        struct tree *subtree = lookup_tree(r, &entry.oid);
 680                        if (!subtree->object.parsed)
 681                                parse_tree(subtree);
 682                        sub = cache_tree_sub(it, entry.path);
 683                        sub->cache_tree = cache_tree();
 684                        prime_cache_tree_rec(r, sub->cache_tree, subtree);
 685                        cnt += sub->cache_tree->entry_count;
 686                }
 687        }
 688        it->entry_count = cnt;
 689}
 690
 691void prime_cache_tree(struct repository *r,
 692                      struct index_state *istate,
 693                      struct tree *tree)
 694{
 695        cache_tree_free(&istate->cache_tree);
 696        istate->cache_tree = cache_tree();
 697        prime_cache_tree_rec(r, istate->cache_tree, tree);
 698        istate->cache_changed |= CACHE_TREE_CHANGED;
 699}
 700
 701/*
 702 * find the cache_tree that corresponds to the current level without
 703 * exploding the full path into textual form.  The root of the
 704 * cache tree is given as "root", and our current level is "info".
 705 * (1) When at root level, info->prev is NULL, so it is "root" itself.
 706 * (2) Otherwise, find the cache_tree that corresponds to one level
 707 *     above us, and find ourselves in there.
 708 */
 709static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
 710                                                         struct traverse_info *info)
 711{
 712        struct cache_tree *our_parent;
 713
 714        if (!info->prev)
 715                return root;
 716        our_parent = find_cache_tree_from_traversal(root, info->prev);
 717        return cache_tree_find(our_parent, info->name);
 718}
 719
 720int cache_tree_matches_traversal(struct cache_tree *root,
 721                                 struct name_entry *ent,
 722                                 struct traverse_info *info)
 723{
 724        struct cache_tree *it;
 725
 726        it = find_cache_tree_from_traversal(root, info);
 727        it = cache_tree_find(it, ent->path);
 728        if (it && it->entry_count > 0 && oideq(&ent->oid, &it->oid))
 729                return it->entry_count;
 730        return 0;
 731}
 732
 733static void verify_one(struct repository *r,
 734                       struct index_state *istate,
 735                       struct cache_tree *it,
 736                       struct strbuf *path)
 737{
 738        int i, pos, len = path->len;
 739        struct strbuf tree_buf = STRBUF_INIT;
 740        struct object_id new_oid;
 741
 742        for (i = 0; i < it->subtree_nr; i++) {
 743                strbuf_addf(path, "%s/", it->down[i]->name);
 744                verify_one(r, istate, it->down[i]->cache_tree, path);
 745                strbuf_setlen(path, len);
 746        }
 747
 748        if (it->entry_count < 0 ||
 749            /* no verification on tests (t7003) that replace trees */
 750            lookup_replace_object(r, &it->oid) != &it->oid)
 751                return;
 752
 753        if (path->len) {
 754                pos = index_name_pos(istate, path->buf, path->len);
 755                pos = -pos - 1;
 756        } else {
 757                pos = 0;
 758        }
 759
 760        i = 0;
 761        while (i < it->entry_count) {
 762                struct cache_entry *ce = istate->cache[pos + i];
 763                const char *slash;
 764                struct cache_tree_sub *sub = NULL;
 765                const struct object_id *oid;
 766                const char *name;
 767                unsigned mode;
 768                int entlen;
 769
 770                if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE))
 771                        BUG("%s with flags 0x%x should not be in cache-tree",
 772                            ce->name, ce->ce_flags);
 773                name = ce->name + path->len;
 774                slash = strchr(name, '/');
 775                if (slash) {
 776                        entlen = slash - name;
 777                        sub = find_subtree(it, ce->name + path->len, entlen, 0);
 778                        if (!sub || sub->cache_tree->entry_count < 0)
 779                                BUG("bad subtree '%.*s'", entlen, name);
 780                        oid = &sub->cache_tree->oid;
 781                        mode = S_IFDIR;
 782                        i += sub->cache_tree->entry_count;
 783                } else {
 784                        oid = &ce->oid;
 785                        mode = ce->ce_mode;
 786                        entlen = ce_namelen(ce) - path->len;
 787                        i++;
 788                }
 789                strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0');
 790                strbuf_add(&tree_buf, oid->hash, the_hash_algo->rawsz);
 791        }
 792        hash_object_file(tree_buf.buf, tree_buf.len, tree_type, &new_oid);
 793        if (!oideq(&new_oid, &it->oid))
 794                BUG("cache-tree for path %.*s does not match. "
 795                    "Expected %s got %s", len, path->buf,
 796                    oid_to_hex(&new_oid), oid_to_hex(&it->oid));
 797        strbuf_setlen(path, len);
 798        strbuf_release(&tree_buf);
 799}
 800
 801void cache_tree_verify(struct repository *r, struct index_state *istate)
 802{
 803        struct strbuf path = STRBUF_INIT;
 804
 805        if (!istate->cache_tree)
 806                return;
 807        verify_one(r, istate, istate->cache_tree, &path);
 808        strbuf_release(&path);
 809}