1a4bd5210SJason Evans /* 2a4bd5210SJason Evans ******************************************************************************* 3a4bd5210SJason Evans * Implementation of (2^1+,2) cuckoo hashing, where 2^1+ indicates that each 4a4bd5210SJason Evans * hash bucket contains 2^n cells, for n >= 1, and 2 indicates that two hash 5a4bd5210SJason Evans * functions are employed. The original cuckoo hashing algorithm was described 6a4bd5210SJason Evans * in: 7a4bd5210SJason Evans * 8a4bd5210SJason Evans * Pagh, R., F.F. Rodler (2004) Cuckoo Hashing. Journal of Algorithms 9a4bd5210SJason Evans * 51(2):122-144. 10a4bd5210SJason Evans * 11a4bd5210SJason Evans * Generalization of cuckoo hashing was discussed in: 12a4bd5210SJason Evans * 13a4bd5210SJason Evans * Erlingsson, U., M. Manasse, F. McSherry (2006) A cool and practical 14a4bd5210SJason Evans * alternative to traditional hash tables. In Proceedings of the 7th 15a4bd5210SJason Evans * Workshop on Distributed Data and Structures (WDAS'06), Santa Clara, CA, 16a4bd5210SJason Evans * January 2006. 17a4bd5210SJason Evans * 18a4bd5210SJason Evans * This implementation uses precisely two hash functions because that is the 19a4bd5210SJason Evans * fewest that can work, and supporting multiple hashes is an implementation 20a4bd5210SJason Evans * burden. Here is a reproduction of Figure 1 from Erlingsson et al. (2006) 21a4bd5210SJason Evans * that shows approximate expected maximum load factors for various 22a4bd5210SJason Evans * configurations: 23a4bd5210SJason Evans * 24a4bd5210SJason Evans * | #cells/bucket | 25a4bd5210SJason Evans * #hashes | 1 | 2 | 4 | 8 | 26a4bd5210SJason Evans * --------+-------+-------+-------+-------+ 27a4bd5210SJason Evans * 1 | 0.006 | 0.006 | 0.03 | 0.12 | 28a4bd5210SJason Evans * 2 | 0.49 | 0.86 |>0.93< |>0.96< | 29a4bd5210SJason Evans * 3 | 0.91 | 0.97 | 0.98 | 0.999 | 30a4bd5210SJason Evans * 4 | 0.97 | 0.99 | 0.999 | | 31a4bd5210SJason Evans * 32a4bd5210SJason Evans * The number of cells per bucket is chosen such that a bucket fits in one cache 33a4bd5210SJason Evans * line. So, on 32- and 64-bit systems, we use (8,2) and (4,2) cuckoo hashing, 34a4bd5210SJason Evans * respectively. 35a4bd5210SJason Evans * 36a4bd5210SJason Evans ******************************************************************************/ 37a4bd5210SJason Evans #define JEMALLOC_CKH_C_ 38a4bd5210SJason Evans #include "jemalloc/internal/jemalloc_internal.h" 39a4bd5210SJason Evans 40a4bd5210SJason Evans /******************************************************************************/ 41a4bd5210SJason Evans /* Function prototypes for non-inline static functions. */ 42a4bd5210SJason Evans 431f0a49e8SJason Evans static bool ckh_grow(tsdn_t *tsdn, ckh_t *ckh); 441f0a49e8SJason Evans static void ckh_shrink(tsdn_t *tsdn, ckh_t *ckh); 45a4bd5210SJason Evans 46a4bd5210SJason Evans /******************************************************************************/ 47a4bd5210SJason Evans 48a4bd5210SJason Evans /* 49a4bd5210SJason Evans * Search bucket for key and return the cell number if found; SIZE_T_MAX 50a4bd5210SJason Evans * otherwise. 51a4bd5210SJason Evans */ 52f921d10fSJason Evans JEMALLOC_INLINE_C size_t 53a4bd5210SJason Evans ckh_bucket_search(ckh_t *ckh, size_t bucket, const void *key) 54a4bd5210SJason Evans { 55a4bd5210SJason Evans ckhc_t *cell; 56a4bd5210SJason Evans unsigned i; 57a4bd5210SJason Evans 58a4bd5210SJason Evans for (i = 0; i < (ZU(1) << LG_CKH_BUCKET_CELLS); i++) { 59a4bd5210SJason Evans cell = &ckh->tab[(bucket << LG_CKH_BUCKET_CELLS) + i]; 60a4bd5210SJason Evans if (cell->key != NULL && ckh->keycomp(key, cell->key)) 61a4bd5210SJason Evans return ((bucket << LG_CKH_BUCKET_CELLS) + i); 62a4bd5210SJason Evans } 63a4bd5210SJason Evans 64a4bd5210SJason Evans return (SIZE_T_MAX); 65a4bd5210SJason Evans } 66a4bd5210SJason Evans 67a4bd5210SJason Evans /* 68a4bd5210SJason Evans * Search table for key and return cell number if found; SIZE_T_MAX otherwise. 69a4bd5210SJason Evans */ 70f921d10fSJason Evans JEMALLOC_INLINE_C size_t 71a4bd5210SJason Evans ckh_isearch(ckh_t *ckh, const void *key) 72a4bd5210SJason Evans { 7388ad2f8dSJason Evans size_t hashes[2], bucket, cell; 74a4bd5210SJason Evans 75a4bd5210SJason Evans assert(ckh != NULL); 76a4bd5210SJason Evans 7788ad2f8dSJason Evans ckh->hash(key, hashes); 78a4bd5210SJason Evans 79a4bd5210SJason Evans /* Search primary bucket. */ 8088ad2f8dSJason Evans bucket = hashes[0] & ((ZU(1) << ckh->lg_curbuckets) - 1); 81a4bd5210SJason Evans cell = ckh_bucket_search(ckh, bucket, key); 82a4bd5210SJason Evans if (cell != SIZE_T_MAX) 83a4bd5210SJason Evans return (cell); 84a4bd5210SJason Evans 85a4bd5210SJason Evans /* Search secondary bucket. */ 8688ad2f8dSJason Evans bucket = hashes[1] & ((ZU(1) << ckh->lg_curbuckets) - 1); 87a4bd5210SJason Evans cell = ckh_bucket_search(ckh, bucket, key); 88a4bd5210SJason Evans return (cell); 89a4bd5210SJason Evans } 90a4bd5210SJason Evans 91f921d10fSJason Evans JEMALLOC_INLINE_C bool 92a4bd5210SJason Evans ckh_try_bucket_insert(ckh_t *ckh, size_t bucket, const void *key, 93a4bd5210SJason Evans const void *data) 94a4bd5210SJason Evans { 95a4bd5210SJason Evans ckhc_t *cell; 96a4bd5210SJason Evans unsigned offset, i; 97a4bd5210SJason Evans 98a4bd5210SJason Evans /* 99a4bd5210SJason Evans * Cycle through the cells in the bucket, starting at a random position. 100a4bd5210SJason Evans * The randomness avoids worst-case search overhead as buckets fill up. 101a4bd5210SJason Evans */ 102df0d881dSJason Evans offset = (unsigned)prng_lg_range(&ckh->prng_state, LG_CKH_BUCKET_CELLS); 103a4bd5210SJason Evans for (i = 0; i < (ZU(1) << LG_CKH_BUCKET_CELLS); i++) { 104a4bd5210SJason Evans cell = &ckh->tab[(bucket << LG_CKH_BUCKET_CELLS) + 105a4bd5210SJason Evans ((i + offset) & ((ZU(1) << LG_CKH_BUCKET_CELLS) - 1))]; 106a4bd5210SJason Evans if (cell->key == NULL) { 107a4bd5210SJason Evans cell->key = key; 108a4bd5210SJason Evans cell->data = data; 109a4bd5210SJason Evans ckh->count++; 110a4bd5210SJason Evans return (false); 111a4bd5210SJason Evans } 112a4bd5210SJason Evans } 113a4bd5210SJason Evans 114a4bd5210SJason Evans return (true); 115a4bd5210SJason Evans } 116a4bd5210SJason Evans 117a4bd5210SJason Evans /* 118a4bd5210SJason Evans * No space is available in bucket. Randomly evict an item, then try to find an 119a4bd5210SJason Evans * alternate location for that item. Iteratively repeat this 120a4bd5210SJason Evans * eviction/relocation procedure until either success or detection of an 121a4bd5210SJason Evans * eviction/relocation bucket cycle. 122a4bd5210SJason Evans */ 123f921d10fSJason Evans JEMALLOC_INLINE_C bool 124a4bd5210SJason Evans ckh_evict_reloc_insert(ckh_t *ckh, size_t argbucket, void const **argkey, 125a4bd5210SJason Evans void const **argdata) 126a4bd5210SJason Evans { 127a4bd5210SJason Evans const void *key, *data, *tkey, *tdata; 128a4bd5210SJason Evans ckhc_t *cell; 12988ad2f8dSJason Evans size_t hashes[2], bucket, tbucket; 130a4bd5210SJason Evans unsigned i; 131a4bd5210SJason Evans 132a4bd5210SJason Evans bucket = argbucket; 133a4bd5210SJason Evans key = *argkey; 134a4bd5210SJason Evans data = *argdata; 135a4bd5210SJason Evans while (true) { 136a4bd5210SJason Evans /* 137a4bd5210SJason Evans * Choose a random item within the bucket to evict. This is 138a4bd5210SJason Evans * critical to correct function, because without (eventually) 139a4bd5210SJason Evans * evicting all items within a bucket during iteration, it 140a4bd5210SJason Evans * would be possible to get stuck in an infinite loop if there 141a4bd5210SJason Evans * were an item for which both hashes indicated the same 142a4bd5210SJason Evans * bucket. 143a4bd5210SJason Evans */ 144df0d881dSJason Evans i = (unsigned)prng_lg_range(&ckh->prng_state, 145df0d881dSJason Evans LG_CKH_BUCKET_CELLS); 146a4bd5210SJason Evans cell = &ckh->tab[(bucket << LG_CKH_BUCKET_CELLS) + i]; 147a4bd5210SJason Evans assert(cell->key != NULL); 148a4bd5210SJason Evans 149a4bd5210SJason Evans /* Swap cell->{key,data} and {key,data} (evict). */ 150a4bd5210SJason Evans tkey = cell->key; tdata = cell->data; 151a4bd5210SJason Evans cell->key = key; cell->data = data; 152a4bd5210SJason Evans key = tkey; data = tdata; 153a4bd5210SJason Evans 154a4bd5210SJason Evans #ifdef CKH_COUNT 155a4bd5210SJason Evans ckh->nrelocs++; 156a4bd5210SJason Evans #endif 157a4bd5210SJason Evans 158a4bd5210SJason Evans /* Find the alternate bucket for the evicted item. */ 15988ad2f8dSJason Evans ckh->hash(key, hashes); 16088ad2f8dSJason Evans tbucket = hashes[1] & ((ZU(1) << ckh->lg_curbuckets) - 1); 161a4bd5210SJason Evans if (tbucket == bucket) { 16288ad2f8dSJason Evans tbucket = hashes[0] & ((ZU(1) << ckh->lg_curbuckets) 16388ad2f8dSJason Evans - 1); 164a4bd5210SJason Evans /* 165a4bd5210SJason Evans * It may be that (tbucket == bucket) still, if the 166a4bd5210SJason Evans * item's hashes both indicate this bucket. However, 167a4bd5210SJason Evans * we are guaranteed to eventually escape this bucket 168a4bd5210SJason Evans * during iteration, assuming pseudo-random item 169a4bd5210SJason Evans * selection (true randomness would make infinite 170a4bd5210SJason Evans * looping a remote possibility). The reason we can 171a4bd5210SJason Evans * never get trapped forever is that there are two 172a4bd5210SJason Evans * cases: 173a4bd5210SJason Evans * 174a4bd5210SJason Evans * 1) This bucket == argbucket, so we will quickly 175a4bd5210SJason Evans * detect an eviction cycle and terminate. 176a4bd5210SJason Evans * 2) An item was evicted to this bucket from another, 177a4bd5210SJason Evans * which means that at least one item in this bucket 178a4bd5210SJason Evans * has hashes that indicate distinct buckets. 179a4bd5210SJason Evans */ 180a4bd5210SJason Evans } 181a4bd5210SJason Evans /* Check for a cycle. */ 182a4bd5210SJason Evans if (tbucket == argbucket) { 183a4bd5210SJason Evans *argkey = key; 184a4bd5210SJason Evans *argdata = data; 185a4bd5210SJason Evans return (true); 186a4bd5210SJason Evans } 187a4bd5210SJason Evans 188a4bd5210SJason Evans bucket = tbucket; 189d0e79aa3SJason Evans if (!ckh_try_bucket_insert(ckh, bucket, key, data)) 190a4bd5210SJason Evans return (false); 191a4bd5210SJason Evans } 192a4bd5210SJason Evans } 193a4bd5210SJason Evans 194f921d10fSJason Evans JEMALLOC_INLINE_C bool 195a4bd5210SJason Evans ckh_try_insert(ckh_t *ckh, void const**argkey, void const**argdata) 196a4bd5210SJason Evans { 19788ad2f8dSJason Evans size_t hashes[2], bucket; 198a4bd5210SJason Evans const void *key = *argkey; 199a4bd5210SJason Evans const void *data = *argdata; 200a4bd5210SJason Evans 20188ad2f8dSJason Evans ckh->hash(key, hashes); 202a4bd5210SJason Evans 203a4bd5210SJason Evans /* Try to insert in primary bucket. */ 20488ad2f8dSJason Evans bucket = hashes[0] & ((ZU(1) << ckh->lg_curbuckets) - 1); 205d0e79aa3SJason Evans if (!ckh_try_bucket_insert(ckh, bucket, key, data)) 206a4bd5210SJason Evans return (false); 207a4bd5210SJason Evans 208a4bd5210SJason Evans /* Try to insert in secondary bucket. */ 20988ad2f8dSJason Evans bucket = hashes[1] & ((ZU(1) << ckh->lg_curbuckets) - 1); 210d0e79aa3SJason Evans if (!ckh_try_bucket_insert(ckh, bucket, key, data)) 211a4bd5210SJason Evans return (false); 212a4bd5210SJason Evans 213a4bd5210SJason Evans /* 214a4bd5210SJason Evans * Try to find a place for this item via iterative eviction/relocation. 215a4bd5210SJason Evans */ 216a4bd5210SJason Evans return (ckh_evict_reloc_insert(ckh, bucket, argkey, argdata)); 217a4bd5210SJason Evans } 218a4bd5210SJason Evans 219a4bd5210SJason Evans /* 220a4bd5210SJason Evans * Try to rebuild the hash table from scratch by inserting all items from the 221a4bd5210SJason Evans * old table into the new. 222a4bd5210SJason Evans */ 223f921d10fSJason Evans JEMALLOC_INLINE_C bool 224a4bd5210SJason Evans ckh_rebuild(ckh_t *ckh, ckhc_t *aTab) 225a4bd5210SJason Evans { 226a4bd5210SJason Evans size_t count, i, nins; 227a4bd5210SJason Evans const void *key, *data; 228a4bd5210SJason Evans 229a4bd5210SJason Evans count = ckh->count; 230a4bd5210SJason Evans ckh->count = 0; 231a4bd5210SJason Evans for (i = nins = 0; nins < count; i++) { 232a4bd5210SJason Evans if (aTab[i].key != NULL) { 233a4bd5210SJason Evans key = aTab[i].key; 234a4bd5210SJason Evans data = aTab[i].data; 235a4bd5210SJason Evans if (ckh_try_insert(ckh, &key, &data)) { 236a4bd5210SJason Evans ckh->count = count; 237a4bd5210SJason Evans return (true); 238a4bd5210SJason Evans } 239a4bd5210SJason Evans nins++; 240a4bd5210SJason Evans } 241a4bd5210SJason Evans } 242a4bd5210SJason Evans 243a4bd5210SJason Evans return (false); 244a4bd5210SJason Evans } 245a4bd5210SJason Evans 246a4bd5210SJason Evans static bool 2471f0a49e8SJason Evans ckh_grow(tsdn_t *tsdn, ckh_t *ckh) 248a4bd5210SJason Evans { 249a4bd5210SJason Evans bool ret; 250a4bd5210SJason Evans ckhc_t *tab, *ttab; 251df0d881dSJason Evans unsigned lg_prevbuckets, lg_curcells; 252a4bd5210SJason Evans 253a4bd5210SJason Evans #ifdef CKH_COUNT 254a4bd5210SJason Evans ckh->ngrows++; 255a4bd5210SJason Evans #endif 256a4bd5210SJason Evans 257a4bd5210SJason Evans /* 258a4bd5210SJason Evans * It is possible (though unlikely, given well behaved hashes) that the 259a4bd5210SJason Evans * table will have to be doubled more than once in order to create a 260a4bd5210SJason Evans * usable table. 261a4bd5210SJason Evans */ 262a4bd5210SJason Evans lg_prevbuckets = ckh->lg_curbuckets; 263a4bd5210SJason Evans lg_curcells = ckh->lg_curbuckets + LG_CKH_BUCKET_CELLS; 264a4bd5210SJason Evans while (true) { 265a4bd5210SJason Evans size_t usize; 266a4bd5210SJason Evans 267a4bd5210SJason Evans lg_curcells++; 268a4bd5210SJason Evans usize = sa2u(sizeof(ckhc_t) << lg_curcells, CACHELINE); 269df0d881dSJason Evans if (unlikely(usize == 0 || usize > HUGE_MAXCLASS)) { 270a4bd5210SJason Evans ret = true; 271a4bd5210SJason Evans goto label_return; 272a4bd5210SJason Evans } 2731f0a49e8SJason Evans tab = (ckhc_t *)ipallocztm(tsdn, usize, CACHELINE, true, NULL, 2741f0a49e8SJason Evans true, arena_ichoose(tsdn, NULL)); 275a4bd5210SJason Evans if (tab == NULL) { 276a4bd5210SJason Evans ret = true; 277a4bd5210SJason Evans goto label_return; 278a4bd5210SJason Evans } 279a4bd5210SJason Evans /* Swap in new table. */ 280a4bd5210SJason Evans ttab = ckh->tab; 281a4bd5210SJason Evans ckh->tab = tab; 282a4bd5210SJason Evans tab = ttab; 283a4bd5210SJason Evans ckh->lg_curbuckets = lg_curcells - LG_CKH_BUCKET_CELLS; 284a4bd5210SJason Evans 285d0e79aa3SJason Evans if (!ckh_rebuild(ckh, tab)) { 2861f0a49e8SJason Evans idalloctm(tsdn, tab, NULL, true, true); 287a4bd5210SJason Evans break; 288a4bd5210SJason Evans } 289a4bd5210SJason Evans 290a4bd5210SJason Evans /* Rebuilding failed, so back out partially rebuilt table. */ 2911f0a49e8SJason Evans idalloctm(tsdn, ckh->tab, NULL, true, true); 292a4bd5210SJason Evans ckh->tab = tab; 293a4bd5210SJason Evans ckh->lg_curbuckets = lg_prevbuckets; 294a4bd5210SJason Evans } 295a4bd5210SJason Evans 296a4bd5210SJason Evans ret = false; 297a4bd5210SJason Evans label_return: 298a4bd5210SJason Evans return (ret); 299a4bd5210SJason Evans } 300a4bd5210SJason Evans 301a4bd5210SJason Evans static void 3021f0a49e8SJason Evans ckh_shrink(tsdn_t *tsdn, ckh_t *ckh) 303a4bd5210SJason Evans { 304a4bd5210SJason Evans ckhc_t *tab, *ttab; 305df0d881dSJason Evans size_t usize; 306df0d881dSJason Evans unsigned lg_prevbuckets, lg_curcells; 307a4bd5210SJason Evans 308a4bd5210SJason Evans /* 309a4bd5210SJason Evans * It is possible (though unlikely, given well behaved hashes) that the 310a4bd5210SJason Evans * table rebuild will fail. 311a4bd5210SJason Evans */ 312a4bd5210SJason Evans lg_prevbuckets = ckh->lg_curbuckets; 313a4bd5210SJason Evans lg_curcells = ckh->lg_curbuckets + LG_CKH_BUCKET_CELLS - 1; 314a4bd5210SJason Evans usize = sa2u(sizeof(ckhc_t) << lg_curcells, CACHELINE); 315df0d881dSJason Evans if (unlikely(usize == 0 || usize > HUGE_MAXCLASS)) 316a4bd5210SJason Evans return; 3171f0a49e8SJason Evans tab = (ckhc_t *)ipallocztm(tsdn, usize, CACHELINE, true, NULL, true, 3181f0a49e8SJason Evans arena_ichoose(tsdn, NULL)); 319a4bd5210SJason Evans if (tab == NULL) { 320a4bd5210SJason Evans /* 321a4bd5210SJason Evans * An OOM error isn't worth propagating, since it doesn't 322a4bd5210SJason Evans * prevent this or future operations from proceeding. 323a4bd5210SJason Evans */ 324a4bd5210SJason Evans return; 325a4bd5210SJason Evans } 326a4bd5210SJason Evans /* Swap in new table. */ 327a4bd5210SJason Evans ttab = ckh->tab; 328a4bd5210SJason Evans ckh->tab = tab; 329a4bd5210SJason Evans tab = ttab; 330a4bd5210SJason Evans ckh->lg_curbuckets = lg_curcells - LG_CKH_BUCKET_CELLS; 331a4bd5210SJason Evans 332d0e79aa3SJason Evans if (!ckh_rebuild(ckh, tab)) { 3331f0a49e8SJason Evans idalloctm(tsdn, tab, NULL, true, true); 334a4bd5210SJason Evans #ifdef CKH_COUNT 335a4bd5210SJason Evans ckh->nshrinks++; 336a4bd5210SJason Evans #endif 337a4bd5210SJason Evans return; 338a4bd5210SJason Evans } 339a4bd5210SJason Evans 340a4bd5210SJason Evans /* Rebuilding failed, so back out partially rebuilt table. */ 3411f0a49e8SJason Evans idalloctm(tsdn, ckh->tab, NULL, true, true); 342a4bd5210SJason Evans ckh->tab = tab; 343a4bd5210SJason Evans ckh->lg_curbuckets = lg_prevbuckets; 344a4bd5210SJason Evans #ifdef CKH_COUNT 345a4bd5210SJason Evans ckh->nshrinkfails++; 346a4bd5210SJason Evans #endif 347a4bd5210SJason Evans } 348a4bd5210SJason Evans 349a4bd5210SJason Evans bool 3501f0a49e8SJason Evans ckh_new(tsdn_t *tsdn, ckh_t *ckh, size_t minitems, ckh_hash_t *hash, 351d0e79aa3SJason Evans ckh_keycomp_t *keycomp) 352a4bd5210SJason Evans { 353a4bd5210SJason Evans bool ret; 354a4bd5210SJason Evans size_t mincells, usize; 355a4bd5210SJason Evans unsigned lg_mincells; 356a4bd5210SJason Evans 357a4bd5210SJason Evans assert(minitems > 0); 358a4bd5210SJason Evans assert(hash != NULL); 359a4bd5210SJason Evans assert(keycomp != NULL); 360a4bd5210SJason Evans 361a4bd5210SJason Evans #ifdef CKH_COUNT 362a4bd5210SJason Evans ckh->ngrows = 0; 363a4bd5210SJason Evans ckh->nshrinks = 0; 364a4bd5210SJason Evans ckh->nshrinkfails = 0; 365a4bd5210SJason Evans ckh->ninserts = 0; 366a4bd5210SJason Evans ckh->nrelocs = 0; 367a4bd5210SJason Evans #endif 368a4bd5210SJason Evans ckh->prng_state = 42; /* Value doesn't really matter. */ 369a4bd5210SJason Evans ckh->count = 0; 370a4bd5210SJason Evans 371a4bd5210SJason Evans /* 372d0e79aa3SJason Evans * Find the minimum power of 2 that is large enough to fit minitems 373a4bd5210SJason Evans * entries. We are using (2+,2) cuckoo hashing, which has an expected 374a4bd5210SJason Evans * maximum load factor of at least ~0.86, so 0.75 is a conservative load 375d0e79aa3SJason Evans * factor that will typically allow mincells items to fit without ever 376a4bd5210SJason Evans * growing the table. 377a4bd5210SJason Evans */ 378a4bd5210SJason Evans assert(LG_CKH_BUCKET_CELLS > 0); 379a4bd5210SJason Evans mincells = ((minitems + (3 - (minitems % 3))) / 3) << 2; 380a4bd5210SJason Evans for (lg_mincells = LG_CKH_BUCKET_CELLS; 381a4bd5210SJason Evans (ZU(1) << lg_mincells) < mincells; 382a4bd5210SJason Evans lg_mincells++) 383a4bd5210SJason Evans ; /* Do nothing. */ 384a4bd5210SJason Evans ckh->lg_minbuckets = lg_mincells - LG_CKH_BUCKET_CELLS; 385a4bd5210SJason Evans ckh->lg_curbuckets = lg_mincells - LG_CKH_BUCKET_CELLS; 386a4bd5210SJason Evans ckh->hash = hash; 387a4bd5210SJason Evans ckh->keycomp = keycomp; 388a4bd5210SJason Evans 389a4bd5210SJason Evans usize = sa2u(sizeof(ckhc_t) << lg_mincells, CACHELINE); 390df0d881dSJason Evans if (unlikely(usize == 0 || usize > HUGE_MAXCLASS)) { 391a4bd5210SJason Evans ret = true; 392a4bd5210SJason Evans goto label_return; 393a4bd5210SJason Evans } 3941f0a49e8SJason Evans ckh->tab = (ckhc_t *)ipallocztm(tsdn, usize, CACHELINE, true, NULL, 3951f0a49e8SJason Evans true, arena_ichoose(tsdn, NULL)); 396a4bd5210SJason Evans if (ckh->tab == NULL) { 397a4bd5210SJason Evans ret = true; 398a4bd5210SJason Evans goto label_return; 399a4bd5210SJason Evans } 400a4bd5210SJason Evans 401a4bd5210SJason Evans ret = false; 402a4bd5210SJason Evans label_return: 403a4bd5210SJason Evans return (ret); 404a4bd5210SJason Evans } 405a4bd5210SJason Evans 406a4bd5210SJason Evans void 4071f0a49e8SJason Evans ckh_delete(tsdn_t *tsdn, ckh_t *ckh) 408a4bd5210SJason Evans { 409a4bd5210SJason Evans 410a4bd5210SJason Evans assert(ckh != NULL); 411a4bd5210SJason Evans 412a4bd5210SJason Evans #ifdef CKH_VERBOSE 413a4bd5210SJason Evans malloc_printf( 414d0e79aa3SJason Evans "%s(%p): ngrows: %"FMTu64", nshrinks: %"FMTu64"," 415d0e79aa3SJason Evans " nshrinkfails: %"FMTu64", ninserts: %"FMTu64"," 416d0e79aa3SJason Evans " nrelocs: %"FMTu64"\n", __func__, ckh, 417a4bd5210SJason Evans (unsigned long long)ckh->ngrows, 418a4bd5210SJason Evans (unsigned long long)ckh->nshrinks, 419a4bd5210SJason Evans (unsigned long long)ckh->nshrinkfails, 420a4bd5210SJason Evans (unsigned long long)ckh->ninserts, 421a4bd5210SJason Evans (unsigned long long)ckh->nrelocs); 422a4bd5210SJason Evans #endif 423a4bd5210SJason Evans 4241f0a49e8SJason Evans idalloctm(tsdn, ckh->tab, NULL, true, true); 42588ad2f8dSJason Evans if (config_debug) 4261f0a49e8SJason Evans memset(ckh, JEMALLOC_FREE_JUNK, sizeof(ckh_t)); 427a4bd5210SJason Evans } 428a4bd5210SJason Evans 429a4bd5210SJason Evans size_t 430a4bd5210SJason Evans ckh_count(ckh_t *ckh) 431a4bd5210SJason Evans { 432a4bd5210SJason Evans 433a4bd5210SJason Evans assert(ckh != NULL); 434a4bd5210SJason Evans 435a4bd5210SJason Evans return (ckh->count); 436a4bd5210SJason Evans } 437a4bd5210SJason Evans 438a4bd5210SJason Evans bool 439a4bd5210SJason Evans ckh_iter(ckh_t *ckh, size_t *tabind, void **key, void **data) 440a4bd5210SJason Evans { 441a4bd5210SJason Evans size_t i, ncells; 442a4bd5210SJason Evans 443a4bd5210SJason Evans for (i = *tabind, ncells = (ZU(1) << (ckh->lg_curbuckets + 444a4bd5210SJason Evans LG_CKH_BUCKET_CELLS)); i < ncells; i++) { 445a4bd5210SJason Evans if (ckh->tab[i].key != NULL) { 446a4bd5210SJason Evans if (key != NULL) 447a4bd5210SJason Evans *key = (void *)ckh->tab[i].key; 448a4bd5210SJason Evans if (data != NULL) 449a4bd5210SJason Evans *data = (void *)ckh->tab[i].data; 450a4bd5210SJason Evans *tabind = i + 1; 451a4bd5210SJason Evans return (false); 452a4bd5210SJason Evans } 453a4bd5210SJason Evans } 454a4bd5210SJason Evans 455a4bd5210SJason Evans return (true); 456a4bd5210SJason Evans } 457a4bd5210SJason Evans 458a4bd5210SJason Evans bool 4591f0a49e8SJason Evans ckh_insert(tsdn_t *tsdn, ckh_t *ckh, const void *key, const void *data) 460a4bd5210SJason Evans { 461a4bd5210SJason Evans bool ret; 462a4bd5210SJason Evans 463a4bd5210SJason Evans assert(ckh != NULL); 464a4bd5210SJason Evans assert(ckh_search(ckh, key, NULL, NULL)); 465a4bd5210SJason Evans 466a4bd5210SJason Evans #ifdef CKH_COUNT 467a4bd5210SJason Evans ckh->ninserts++; 468a4bd5210SJason Evans #endif 469a4bd5210SJason Evans 470a4bd5210SJason Evans while (ckh_try_insert(ckh, &key, &data)) { 4711f0a49e8SJason Evans if (ckh_grow(tsdn, ckh)) { 472a4bd5210SJason Evans ret = true; 473a4bd5210SJason Evans goto label_return; 474a4bd5210SJason Evans } 475a4bd5210SJason Evans } 476a4bd5210SJason Evans 477a4bd5210SJason Evans ret = false; 478a4bd5210SJason Evans label_return: 479a4bd5210SJason Evans return (ret); 480a4bd5210SJason Evans } 481a4bd5210SJason Evans 482a4bd5210SJason Evans bool 4831f0a49e8SJason Evans ckh_remove(tsdn_t *tsdn, ckh_t *ckh, const void *searchkey, void **key, 484d0e79aa3SJason Evans void **data) 485a4bd5210SJason Evans { 486a4bd5210SJason Evans size_t cell; 487a4bd5210SJason Evans 488a4bd5210SJason Evans assert(ckh != NULL); 489a4bd5210SJason Evans 490a4bd5210SJason Evans cell = ckh_isearch(ckh, searchkey); 491a4bd5210SJason Evans if (cell != SIZE_T_MAX) { 492a4bd5210SJason Evans if (key != NULL) 493a4bd5210SJason Evans *key = (void *)ckh->tab[cell].key; 494a4bd5210SJason Evans if (data != NULL) 495a4bd5210SJason Evans *data = (void *)ckh->tab[cell].data; 496a4bd5210SJason Evans ckh->tab[cell].key = NULL; 497a4bd5210SJason Evans ckh->tab[cell].data = NULL; /* Not necessary. */ 498a4bd5210SJason Evans 499a4bd5210SJason Evans ckh->count--; 500a4bd5210SJason Evans /* Try to halve the table if it is less than 1/4 full. */ 501a4bd5210SJason Evans if (ckh->count < (ZU(1) << (ckh->lg_curbuckets 502a4bd5210SJason Evans + LG_CKH_BUCKET_CELLS - 2)) && ckh->lg_curbuckets 503a4bd5210SJason Evans > ckh->lg_minbuckets) { 504a4bd5210SJason Evans /* Ignore error due to OOM. */ 5051f0a49e8SJason Evans ckh_shrink(tsdn, ckh); 506a4bd5210SJason Evans } 507a4bd5210SJason Evans 508a4bd5210SJason Evans return (false); 509a4bd5210SJason Evans } 510a4bd5210SJason Evans 511a4bd5210SJason Evans return (true); 512a4bd5210SJason Evans } 513a4bd5210SJason Evans 514a4bd5210SJason Evans bool 515a4bd5210SJason Evans ckh_search(ckh_t *ckh, const void *searchkey, void **key, void **data) 516a4bd5210SJason Evans { 517a4bd5210SJason Evans size_t cell; 518a4bd5210SJason Evans 519a4bd5210SJason Evans assert(ckh != NULL); 520a4bd5210SJason Evans 521a4bd5210SJason Evans cell = ckh_isearch(ckh, searchkey); 522a4bd5210SJason Evans if (cell != SIZE_T_MAX) { 523a4bd5210SJason Evans if (key != NULL) 524a4bd5210SJason Evans *key = (void *)ckh->tab[cell].key; 525a4bd5210SJason Evans if (data != NULL) 526a4bd5210SJason Evans *data = (void *)ckh->tab[cell].data; 527a4bd5210SJason Evans return (false); 528a4bd5210SJason Evans } 529a4bd5210SJason Evans 530a4bd5210SJason Evans return (true); 531a4bd5210SJason Evans } 532a4bd5210SJason Evans 533a4bd5210SJason Evans void 53488ad2f8dSJason Evans ckh_string_hash(const void *key, size_t r_hash[2]) 535a4bd5210SJason Evans { 536a4bd5210SJason Evans 53788ad2f8dSJason Evans hash(key, strlen((const char *)key), 0x94122f33U, r_hash); 538a4bd5210SJason Evans } 539a4bd5210SJason Evans 540a4bd5210SJason Evans bool 541a4bd5210SJason Evans ckh_string_keycomp(const void *k1, const void *k2) 542a4bd5210SJason Evans { 543a4bd5210SJason Evans 544a4bd5210SJason Evans assert(k1 != NULL); 545a4bd5210SJason Evans assert(k2 != NULL); 546a4bd5210SJason Evans 547a4bd5210SJason Evans return (strcmp((char *)k1, (char *)k2) ? false : true); 548a4bd5210SJason Evans } 549a4bd5210SJason Evans 550a4bd5210SJason Evans void 55188ad2f8dSJason Evans ckh_pointer_hash(const void *key, size_t r_hash[2]) 552a4bd5210SJason Evans { 553a4bd5210SJason Evans union { 554a4bd5210SJason Evans const void *v; 55588ad2f8dSJason Evans size_t i; 556a4bd5210SJason Evans } u; 557a4bd5210SJason Evans 558a4bd5210SJason Evans assert(sizeof(u.v) == sizeof(u.i)); 559a4bd5210SJason Evans u.v = key; 56088ad2f8dSJason Evans hash(&u.i, sizeof(u.i), 0xd983396eU, r_hash); 561a4bd5210SJason Evans } 562a4bd5210SJason Evans 563a4bd5210SJason Evans bool 564a4bd5210SJason Evans ckh_pointer_keycomp(const void *k1, const void *k2) 565a4bd5210SJason Evans { 566a4bd5210SJason Evans 567a4bd5210SJason Evans return ((k1 == k2) ? true : false); 568a4bd5210SJason Evans } 569