name-hash.con commit Merge branch 'pw/rebase-i-regression-fix' into maint (19a23d6)
   1/*
   2 * name-hash.c
   3 *
   4 * Hashing names in the index state
   5 *
   6 * Copyright (C) 2008 Linus Torvalds
   7 */
   8#define NO_THE_INDEX_COMPATIBILITY_MACROS
   9#include "cache.h"
  10
  11struct dir_entry {
  12        struct hashmap_entry ent;
  13        struct dir_entry *parent;
  14        int nr;
  15        unsigned int namelen;
  16        char name[FLEX_ARRAY];
  17};
  18
  19static int dir_entry_cmp(const struct dir_entry *e1,
  20                const struct dir_entry *e2, const char *name)
  21{
  22        return e1->namelen != e2->namelen || strncasecmp(e1->name,
  23                        name ? name : e2->name, e1->namelen);
  24}
  25
  26static struct dir_entry *find_dir_entry__hash(struct index_state *istate,
  27                const char *name, unsigned int namelen, unsigned int hash)
  28{
  29        struct dir_entry key;
  30        hashmap_entry_init(&key, hash);
  31        key.namelen = namelen;
  32        return hashmap_get(&istate->dir_hash, &key, name);
  33}
  34
  35static struct dir_entry *find_dir_entry(struct index_state *istate,
  36                const char *name, unsigned int namelen)
  37{
  38        return find_dir_entry__hash(istate, name, namelen, memihash(name, namelen));
  39}
  40
  41static struct dir_entry *hash_dir_entry(struct index_state *istate,
  42                struct cache_entry *ce, int namelen)
  43{
  44        /*
  45         * Throw each directory component in the hash for quick lookup
  46         * during a git status. Directory components are stored without their
  47         * closing slash.  Despite submodules being a directory, they never
  48         * reach this point, because they are stored
  49         * in index_state.name_hash (as ordinary cache_entries).
  50         */
  51        struct dir_entry *dir;
  52
  53        /* get length of parent directory */
  54        while (namelen > 0 && !is_dir_sep(ce->name[namelen - 1]))
  55                namelen--;
  56        if (namelen <= 0)
  57                return NULL;
  58        namelen--;
  59
  60        /* lookup existing entry for that directory */
  61        dir = find_dir_entry(istate, ce->name, namelen);
  62        if (!dir) {
  63                /* not found, create it and add to hash table */
  64                FLEX_ALLOC_MEM(dir, name, ce->name, namelen);
  65                hashmap_entry_init(dir, memihash(ce->name, namelen));
  66                dir->namelen = namelen;
  67                hashmap_add(&istate->dir_hash, dir);
  68
  69                /* recursively add missing parent directories */
  70                dir->parent = hash_dir_entry(istate, ce, namelen);
  71        }
  72        return dir;
  73}
  74
  75static void add_dir_entry(struct index_state *istate, struct cache_entry *ce)
  76{
  77        /* Add reference to the directory entry (and parents if 0). */
  78        struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce));
  79        while (dir && !(dir->nr++))
  80                dir = dir->parent;
  81}
  82
  83static void remove_dir_entry(struct index_state *istate, struct cache_entry *ce)
  84{
  85        /*
  86         * Release reference to the directory entry. If 0, remove and continue
  87         * with parent directory.
  88         */
  89        struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce));
  90        while (dir && !(--dir->nr)) {
  91                struct dir_entry *parent = dir->parent;
  92                hashmap_remove(&istate->dir_hash, dir, NULL);
  93                free(dir);
  94                dir = parent;
  95        }
  96}
  97
  98static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
  99{
 100        if (ce->ce_flags & CE_HASHED)
 101                return;
 102        ce->ce_flags |= CE_HASHED;
 103        hashmap_entry_init(ce, memihash(ce->name, ce_namelen(ce)));
 104        hashmap_add(&istate->name_hash, ce);
 105
 106        if (ignore_case)
 107                add_dir_entry(istate, ce);
 108}
 109
 110static int cache_entry_cmp(const struct cache_entry *ce1,
 111                const struct cache_entry *ce2, const void *remove)
 112{
 113        /*
 114         * For remove_name_hash, find the exact entry (pointer equality); for
 115         * index_file_exists, find all entries with matching hash code and
 116         * decide whether the entry matches in same_name.
 117         */
 118        return remove ? !(ce1 == ce2) : 0;
 119}
 120
 121static int lazy_try_threaded = 1;
 122static int lazy_nr_dir_threads;
 123
 124#ifdef NO_PTHREADS
 125
 126static inline int lookup_lazy_params(struct index_state *istate)
 127{
 128        return 0;
 129}
 130
 131static inline void threaded_lazy_init_name_hash(
 132        struct index_state *istate)
 133{
 134}
 135
 136#else
 137
 138#include "thread-utils.h"
 139
 140/*
 141 * Set a minimum number of cache_entries that we will handle per
 142 * thread and use that to decide how many threads to run (upto
 143 * the number on the system).
 144 *
 145 * For guidance setting the lower per-thread bound, see:
 146 *     t/helper/test-lazy-init-name-hash --analyze
 147 */
 148#define LAZY_THREAD_COST (2000)
 149
 150/*
 151 * We use n mutexes to guard n partitions of the "istate->dir_hash"
 152 * hashtable.  Since "find" and "insert" operations will hash to a
 153 * particular bucket and modify/search a single chain, we can say
 154 * that "all chains mod n" are guarded by the same mutex -- rather
 155 * than having a single mutex to guard the entire table.  (This does
 156 * require that we disable "rehashing" on the hashtable.)
 157 *
 158 * So, a larger value here decreases the probability of a collision
 159 * and the time that each thread must wait for the mutex.
 160 */
 161#define LAZY_MAX_MUTEX   (32)
 162
 163static pthread_mutex_t *lazy_dir_mutex_array;
 164
 165/*
 166 * An array of lazy_entry items is used by the n threads in
 167 * the directory parse (first) phase to (lock-free) store the
 168 * intermediate results.  These values are then referenced by
 169 * the 2 threads in the second phase.
 170 */
 171struct lazy_entry {
 172        struct dir_entry *dir;
 173        unsigned int hash_dir;
 174        unsigned int hash_name;
 175};
 176
 177/*
 178 * Decide if we want to use threads (if available) to load
 179 * the hash tables.  We set "lazy_nr_dir_threads" to zero when
 180 * it is not worth it.
 181 */
 182static int lookup_lazy_params(struct index_state *istate)
 183{
 184        int nr_cpus;
 185
 186        lazy_nr_dir_threads = 0;
 187
 188        if (!lazy_try_threaded)
 189                return 0;
 190
 191        /*
 192         * If we are respecting case, just use the original
 193         * code to build the "istate->name_hash".  We don't
 194         * need the complexity here.
 195         */
 196        if (!ignore_case)
 197                return 0;
 198
 199        nr_cpus = online_cpus();
 200        if (nr_cpus < 2)
 201                return 0;
 202
 203        if (istate->cache_nr < 2 * LAZY_THREAD_COST)
 204                return 0;
 205
 206        if (istate->cache_nr < nr_cpus * LAZY_THREAD_COST)
 207                nr_cpus = istate->cache_nr / LAZY_THREAD_COST;
 208        lazy_nr_dir_threads = nr_cpus;
 209        return lazy_nr_dir_threads;
 210}
 211
 212/*
 213 * Initialize n mutexes for use when searching and inserting
 214 * into "istate->dir_hash".  All "dir" threads are trying
 215 * to insert partial pathnames into the hash as they iterate
 216 * over their portions of the index, so lock contention is
 217 * high.
 218 *
 219 * However, the hashmap is going to put items into bucket
 220 * chains based on their hash values.  Use that to create n
 221 * mutexes and lock on mutex[bucket(hash) % n].  This will
 222 * decrease the collision rate by (hopefully) by a factor of n.
 223 */
 224static void init_dir_mutex(void)
 225{
 226        int j;
 227
 228        lazy_dir_mutex_array = xcalloc(LAZY_MAX_MUTEX, sizeof(pthread_mutex_t));
 229
 230        for (j = 0; j < LAZY_MAX_MUTEX; j++)
 231                init_recursive_mutex(&lazy_dir_mutex_array[j]);
 232}
 233
 234static void cleanup_dir_mutex(void)
 235{
 236        int j;
 237
 238        for (j = 0; j < LAZY_MAX_MUTEX; j++)
 239                pthread_mutex_destroy(&lazy_dir_mutex_array[j]);
 240
 241        free(lazy_dir_mutex_array);
 242}
 243
 244static void lock_dir_mutex(int j)
 245{
 246        pthread_mutex_lock(&lazy_dir_mutex_array[j]);
 247}
 248
 249static void unlock_dir_mutex(int j)
 250{
 251        pthread_mutex_unlock(&lazy_dir_mutex_array[j]);
 252}
 253
 254static inline int compute_dir_lock_nr(
 255        const struct hashmap *map,
 256        unsigned int hash)
 257{
 258        return hashmap_bucket(map, hash) % LAZY_MAX_MUTEX;
 259}
 260
 261static struct dir_entry *hash_dir_entry_with_parent_and_prefix(
 262        struct index_state *istate,
 263        struct dir_entry *parent,
 264        struct strbuf *prefix)
 265{
 266        struct dir_entry *dir;
 267        unsigned int hash;
 268        int lock_nr;
 269
 270        /*
 271         * Either we have a parent directory and path with slash(es)
 272         * or the directory is an immediate child of the root directory.
 273         */
 274        assert((parent != NULL) ^ (strchr(prefix->buf, '/') == NULL));
 275
 276        if (parent)
 277                hash = memihash_cont(parent->ent.hash,
 278                        prefix->buf + parent->namelen,
 279                        prefix->len - parent->namelen);
 280        else
 281                hash = memihash(prefix->buf, prefix->len);
 282
 283        lock_nr = compute_dir_lock_nr(&istate->dir_hash, hash);
 284        lock_dir_mutex(lock_nr);
 285
 286        dir = find_dir_entry__hash(istate, prefix->buf, prefix->len, hash);
 287        if (!dir) {
 288                FLEX_ALLOC_MEM(dir, name, prefix->buf, prefix->len);
 289                hashmap_entry_init(dir, hash);
 290                dir->namelen = prefix->len;
 291                dir->parent = parent;
 292                hashmap_add(&istate->dir_hash, dir);
 293
 294                if (parent) {
 295                        unlock_dir_mutex(lock_nr);
 296
 297                        /* All I really need here is an InterlockedIncrement(&(parent->nr)) */
 298                        lock_nr = compute_dir_lock_nr(&istate->dir_hash, parent->ent.hash);
 299                        lock_dir_mutex(lock_nr);
 300                        parent->nr++;
 301                }
 302        }
 303
 304        unlock_dir_mutex(lock_nr);
 305
 306        return dir;
 307}
 308
 309/*
 310 * handle_range_1() and handle_range_dir() are derived from
 311 * clear_ce_flags_1() and clear_ce_flags_dir() in unpack-trees.c
 312 * and handle the iteration over the entire array of index entries.
 313 * They use recursion for adjacent entries in the same parent
 314 * directory.
 315 */
 316static int handle_range_1(
 317        struct index_state *istate,
 318        int k_start,
 319        int k_end,
 320        struct dir_entry *parent,
 321        struct strbuf *prefix,
 322        struct lazy_entry *lazy_entries);
 323
 324static int handle_range_dir(
 325        struct index_state *istate,
 326        int k_start,
 327        int k_end,
 328        struct dir_entry *parent,
 329        struct strbuf *prefix,
 330        struct lazy_entry *lazy_entries,
 331        struct dir_entry **dir_new_out)
 332{
 333        int rc, k;
 334        int input_prefix_len = prefix->len;
 335        struct dir_entry *dir_new;
 336
 337        dir_new = hash_dir_entry_with_parent_and_prefix(istate, parent, prefix);
 338
 339        strbuf_addch(prefix, '/');
 340
 341        /*
 342         * Scan forward in the index array for index entries having the same
 343         * path prefix (that are also in this directory).
 344         */
 345        if (k_start + 1 >= k_end)
 346                k = k_end;
 347        else if (strncmp(istate->cache[k_start + 1]->name, prefix->buf, prefix->len) > 0)
 348                k = k_start + 1;
 349        else if (strncmp(istate->cache[k_end - 1]->name, prefix->buf, prefix->len) == 0)
 350                k = k_end;
 351        else {
 352                int begin = k_start;
 353                int end = k_end;
 354                while (begin < end) {
 355                        int mid = (begin + end) >> 1;
 356                        int cmp = strncmp(istate->cache[mid]->name, prefix->buf, prefix->len);
 357                        if (cmp == 0) /* mid has same prefix; look in second part */
 358                                begin = mid + 1;
 359                        else if (cmp > 0) /* mid is past group; look in first part */
 360                                end = mid;
 361                        else
 362                                die("cache entry out of order");
 363                }
 364                k = begin;
 365        }
 366
 367        /*
 368         * Recurse and process what we can of this subset [k_start, k).
 369         */
 370        rc = handle_range_1(istate, k_start, k, dir_new, prefix, lazy_entries);
 371
 372        strbuf_setlen(prefix, input_prefix_len);
 373
 374        *dir_new_out = dir_new;
 375        return rc;
 376}
 377
 378static int handle_range_1(
 379        struct index_state *istate,
 380        int k_start,
 381        int k_end,
 382        struct dir_entry *parent,
 383        struct strbuf *prefix,
 384        struct lazy_entry *lazy_entries)
 385{
 386        int input_prefix_len = prefix->len;
 387        int k = k_start;
 388
 389        while (k < k_end) {
 390                struct cache_entry *ce_k = istate->cache[k];
 391                const char *name, *slash;
 392
 393                if (prefix->len && strncmp(ce_k->name, prefix->buf, prefix->len))
 394                        break;
 395
 396                name = ce_k->name + prefix->len;
 397                slash = strchr(name, '/');
 398
 399                if (slash) {
 400                        int len = slash - name;
 401                        int processed;
 402                        struct dir_entry *dir_new;
 403
 404                        strbuf_add(prefix, name, len);
 405                        processed = handle_range_dir(istate, k, k_end, parent, prefix, lazy_entries, &dir_new);
 406                        if (processed) {
 407                                k += processed;
 408                                strbuf_setlen(prefix, input_prefix_len);
 409                                continue;
 410                        }
 411
 412                        strbuf_addch(prefix, '/');
 413                        processed = handle_range_1(istate, k, k_end, dir_new, prefix, lazy_entries);
 414                        k += processed;
 415                        strbuf_setlen(prefix, input_prefix_len);
 416                        continue;
 417                }
 418
 419                /*
 420                 * It is too expensive to take a lock to insert "ce_k"
 421                 * into "istate->name_hash" and increment the ref-count
 422                 * on the "parent" dir.  So we defer actually updating
 423                 * permanent data structures until phase 2 (where we
 424                 * can change the locking requirements) and simply
 425                 * accumulate our current results into the lazy_entries
 426                 * data array).
 427                 *
 428                 * We do not need to lock the lazy_entries array because
 429                 * we have exclusive access to the cells in the range
 430                 * [k_start,k_end) that this thread was given.
 431                 */
 432                lazy_entries[k].dir = parent;
 433                if (parent) {
 434                        lazy_entries[k].hash_name = memihash_cont(
 435                                parent->ent.hash,
 436                                ce_k->name + parent->namelen,
 437                                ce_namelen(ce_k) - parent->namelen);
 438                        lazy_entries[k].hash_dir = parent->ent.hash;
 439                } else {
 440                        lazy_entries[k].hash_name = memihash(ce_k->name, ce_namelen(ce_k));
 441                }
 442
 443                k++;
 444        }
 445
 446        return k - k_start;
 447}
 448
 449struct lazy_dir_thread_data {
 450        pthread_t pthread;
 451        struct index_state *istate;
 452        struct lazy_entry *lazy_entries;
 453        int k_start;
 454        int k_end;
 455};
 456
 457static void *lazy_dir_thread_proc(void *_data)
 458{
 459        struct lazy_dir_thread_data *d = _data;
 460        struct strbuf prefix = STRBUF_INIT;
 461        handle_range_1(d->istate, d->k_start, d->k_end, NULL, &prefix, d->lazy_entries);
 462        strbuf_release(&prefix);
 463        return NULL;
 464}
 465
 466struct lazy_name_thread_data {
 467        pthread_t pthread;
 468        struct index_state *istate;
 469        struct lazy_entry *lazy_entries;
 470};
 471
 472static void *lazy_name_thread_proc(void *_data)
 473{
 474        struct lazy_name_thread_data *d = _data;
 475        int k;
 476
 477        for (k = 0; k < d->istate->cache_nr; k++) {
 478                struct cache_entry *ce_k = d->istate->cache[k];
 479                ce_k->ce_flags |= CE_HASHED;
 480                hashmap_entry_init(ce_k, d->lazy_entries[k].hash_name);
 481                hashmap_add(&d->istate->name_hash, ce_k);
 482        }
 483
 484        return NULL;
 485}
 486
 487static inline void lazy_update_dir_ref_counts(
 488        struct index_state *istate,
 489        struct lazy_entry *lazy_entries)
 490{
 491        int k;
 492
 493        for (k = 0; k < istate->cache_nr; k++) {
 494                if (lazy_entries[k].dir)
 495                        lazy_entries[k].dir->nr++;
 496        }
 497}
 498
 499static void threaded_lazy_init_name_hash(
 500        struct index_state *istate)
 501{
 502        int nr_each;
 503        int k_start;
 504        int t;
 505        struct lazy_entry *lazy_entries;
 506        struct lazy_dir_thread_data *td_dir;
 507        struct lazy_name_thread_data *td_name;
 508
 509        k_start = 0;
 510        nr_each = DIV_ROUND_UP(istate->cache_nr, lazy_nr_dir_threads);
 511
 512        lazy_entries = xcalloc(istate->cache_nr, sizeof(struct lazy_entry));
 513        td_dir = xcalloc(lazy_nr_dir_threads, sizeof(struct lazy_dir_thread_data));
 514        td_name = xcalloc(1, sizeof(struct lazy_name_thread_data));
 515
 516        init_dir_mutex();
 517
 518        /*
 519         * Phase 1:
 520         * Build "istate->dir_hash" using n "dir" threads (and a read-only index).
 521         */
 522        for (t = 0; t < lazy_nr_dir_threads; t++) {
 523                struct lazy_dir_thread_data *td_dir_t = td_dir + t;
 524                td_dir_t->istate = istate;
 525                td_dir_t->lazy_entries = lazy_entries;
 526                td_dir_t->k_start = k_start;
 527                k_start += nr_each;
 528                if (k_start > istate->cache_nr)
 529                        k_start = istate->cache_nr;
 530                td_dir_t->k_end = k_start;
 531                if (pthread_create(&td_dir_t->pthread, NULL, lazy_dir_thread_proc, td_dir_t))
 532                        die("unable to create lazy_dir_thread");
 533        }
 534        for (t = 0; t < lazy_nr_dir_threads; t++) {
 535                struct lazy_dir_thread_data *td_dir_t = td_dir + t;
 536                if (pthread_join(td_dir_t->pthread, NULL))
 537                        die("unable to join lazy_dir_thread");
 538        }
 539
 540        /*
 541         * Phase 2:
 542         * Iterate over all index entries and add them to the "istate->name_hash"
 543         * using a single "name" background thread.
 544         * (Testing showed it wasn't worth running more than 1 thread for this.)
 545         *
 546         * Meanwhile, finish updating the parent directory ref-counts for each
 547         * index entry using the current thread.  (This step is very fast and
 548         * doesn't need threading.)
 549         */
 550        td_name->istate = istate;
 551        td_name->lazy_entries = lazy_entries;
 552        if (pthread_create(&td_name->pthread, NULL, lazy_name_thread_proc, td_name))
 553                die("unable to create lazy_name_thread");
 554
 555        lazy_update_dir_ref_counts(istate, lazy_entries);
 556
 557        if (pthread_join(td_name->pthread, NULL))
 558                die("unable to join lazy_name_thread");
 559
 560        cleanup_dir_mutex();
 561
 562        free(td_name);
 563        free(td_dir);
 564        free(lazy_entries);
 565}
 566
 567#endif
 568
 569static void lazy_init_name_hash(struct index_state *istate)
 570{
 571        if (istate->name_hash_initialized)
 572                return;
 573        hashmap_init(&istate->name_hash, (hashmap_cmp_fn) cache_entry_cmp,
 574                        istate->cache_nr);
 575        hashmap_init(&istate->dir_hash, (hashmap_cmp_fn) dir_entry_cmp,
 576                        istate->cache_nr);
 577
 578        if (lookup_lazy_params(istate)) {
 579                hashmap_disallow_rehash(&istate->dir_hash, 1);
 580                threaded_lazy_init_name_hash(istate);
 581                hashmap_disallow_rehash(&istate->dir_hash, 0);
 582        } else {
 583                int nr;
 584                for (nr = 0; nr < istate->cache_nr; nr++)
 585                        hash_index_entry(istate, istate->cache[nr]);
 586        }
 587
 588        istate->name_hash_initialized = 1;
 589}
 590
 591/*
 592 * A test routine for t/helper/ sources.
 593 *
 594 * Returns the number of threads used or 0 when
 595 * the non-threaded code path was used.
 596 *
 597 * Requesting threading WILL NOT override guards
 598 * in lookup_lazy_params().
 599 */
 600int test_lazy_init_name_hash(struct index_state *istate, int try_threaded)
 601{
 602        lazy_nr_dir_threads = 0;
 603        lazy_try_threaded = try_threaded;
 604
 605        lazy_init_name_hash(istate);
 606
 607        return lazy_nr_dir_threads;
 608}
 609
 610void add_name_hash(struct index_state *istate, struct cache_entry *ce)
 611{
 612        if (istate->name_hash_initialized)
 613                hash_index_entry(istate, ce);
 614}
 615
 616void remove_name_hash(struct index_state *istate, struct cache_entry *ce)
 617{
 618        if (!istate->name_hash_initialized || !(ce->ce_flags & CE_HASHED))
 619                return;
 620        ce->ce_flags &= ~CE_HASHED;
 621        hashmap_remove(&istate->name_hash, ce, ce);
 622
 623        if (ignore_case)
 624                remove_dir_entry(istate, ce);
 625}
 626
 627static int slow_same_name(const char *name1, int len1, const char *name2, int len2)
 628{
 629        if (len1 != len2)
 630                return 0;
 631
 632        while (len1) {
 633                unsigned char c1 = *name1++;
 634                unsigned char c2 = *name2++;
 635                len1--;
 636                if (c1 != c2) {
 637                        c1 = toupper(c1);
 638                        c2 = toupper(c2);
 639                        if (c1 != c2)
 640                                return 0;
 641                }
 642        }
 643        return 1;
 644}
 645
 646static int same_name(const struct cache_entry *ce, const char *name, int namelen, int icase)
 647{
 648        int len = ce_namelen(ce);
 649
 650        /*
 651         * Always do exact compare, even if we want a case-ignoring comparison;
 652         * we do the quick exact one first, because it will be the common case.
 653         */
 654        if (len == namelen && !memcmp(name, ce->name, len))
 655                return 1;
 656
 657        if (!icase)
 658                return 0;
 659
 660        return slow_same_name(name, namelen, ce->name, len);
 661}
 662
 663int index_dir_exists(struct index_state *istate, const char *name, int namelen)
 664{
 665        struct dir_entry *dir;
 666
 667        lazy_init_name_hash(istate);
 668        dir = find_dir_entry(istate, name, namelen);
 669        return dir && dir->nr;
 670}
 671
 672void adjust_dirname_case(struct index_state *istate, char *name)
 673{
 674        const char *startPtr = name;
 675        const char *ptr = startPtr;
 676
 677        lazy_init_name_hash(istate);
 678        while (*ptr) {
 679                while (*ptr && *ptr != '/')
 680                        ptr++;
 681
 682                if (*ptr == '/') {
 683                        struct dir_entry *dir;
 684
 685                        ptr++;
 686                        dir = find_dir_entry(istate, name, ptr - name + 1);
 687                        if (dir) {
 688                                memcpy((void *)startPtr, dir->name + (startPtr - name), ptr - startPtr);
 689                                startPtr = ptr;
 690                        }
 691                }
 692        }
 693}
 694
 695struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int icase)
 696{
 697        struct cache_entry *ce;
 698
 699        lazy_init_name_hash(istate);
 700
 701        ce = hashmap_get_from_hash(&istate->name_hash,
 702                                   memihash(name, namelen), NULL);
 703        while (ce) {
 704                if (same_name(ce, name, namelen, icase))
 705                        return ce;
 706                ce = hashmap_get_next(&istate->name_hash, ce);
 707        }
 708        return NULL;
 709}
 710
 711void free_name_hash(struct index_state *istate)
 712{
 713        if (!istate->name_hash_initialized)
 714                return;
 715        istate->name_hash_initialized = 0;
 716
 717        hashmap_free(&istate->name_hash, 0);
 718        hashmap_free(&istate->dir_hash, 1);
 719}