diff options
Diffstat (limited to 'src/third_party/js-1.7/jshash.c')
| -rw-r--r-- | src/third_party/js-1.7/jshash.c | 483 |
1 files changed, 0 insertions, 483 deletions
diff --git a/src/third_party/js-1.7/jshash.c b/src/third_party/js-1.7/jshash.c deleted file mode 100644 index 8e25517d5c0..00000000000 --- a/src/third_party/js-1.7/jshash.c +++ /dev/null @@ -1,483 +0,0 @@ -/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- - * - * ***** BEGIN LICENSE BLOCK ***** - * Version: MPL 1.1/GPL 2.0/LGPL 2.1 - * - * The contents of this file are subject to the Mozilla Public License Version - * 1.1 (the "License"); you may not use this file except in compliance with - * the License. You may obtain a copy of the License at - * http://www.mozilla.org/MPL/ - * - * Software distributed under the License is distributed on an "AS IS" basis, - * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License - * for the specific language governing rights and limitations under the - * License. - * - * The Original Code is Mozilla Communicator client code, released - * March 31, 1998. - * - * The Initial Developer of the Original Code is - * Netscape Communications Corporation. - * Portions created by the Initial Developer are Copyright (C) 1998 - * the Initial Developer. All Rights Reserved. - * - * Contributor(s): - * - * Alternatively, the contents of this file may be used under the terms of - * either of the GNU General Public License Version 2 or later (the "GPL"), - * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), - * in which case the provisions of the GPL or the LGPL are applicable instead - * of those above. If you wish to allow use of your version of this file only - * under the terms of either the GPL or the LGPL, and not to allow others to - * use your version of this file under the terms of the MPL, indicate your - * decision by deleting the provisions above and replace them with the notice - * and other provisions required by the GPL or the LGPL. If you do not delete - * the provisions above, a recipient may use your version of this file under - * the terms of any one of the MPL, the GPL or the LGPL. - * - * ***** END LICENSE BLOCK ***** */ - -/* - * PR hash table package. - */ -#include "jsstddef.h" -#include <stdlib.h> -#include <string.h> -#include "jstypes.h" -#include "jsbit.h" -#include "jsutil.h" /* Added by JSIFY */ -#include "jshash.h" /* Added by JSIFY */ - -/* Compute the number of buckets in ht */ -#define NBUCKETS(ht) JS_BIT(JS_HASH_BITS - (ht)->shift) - -/* The smallest table has 16 buckets */ -#define MINBUCKETSLOG2 4 -#define MINBUCKETS JS_BIT(MINBUCKETSLOG2) - -/* Compute the maximum entries given n buckets that we will tolerate, ~90% */ -#define OVERLOADED(n) ((n) - ((n) >> 3)) - -/* Compute the number of entries below which we shrink the table by half */ -#define UNDERLOADED(n) (((n) > MINBUCKETS) ? ((n) >> 2) : 0) - -/* -** Stubs for default hash allocator ops. -*/ -static void * -DefaultAllocTable(void *pool, size_t size) -{ - return malloc(size); -} - -static void -DefaultFreeTable(void *pool, void *item) -{ - free(item); -} - -static JSHashEntry * -DefaultAllocEntry(void *pool, const void *key) -{ - return (JSHashEntry*) malloc(sizeof(JSHashEntry)); -} - -static void -DefaultFreeEntry(void *pool, JSHashEntry *he, uintN flag) -{ - if (flag == HT_FREE_ENTRY) - free(he); -} - -static JSHashAllocOps defaultHashAllocOps = { - DefaultAllocTable, DefaultFreeTable, - DefaultAllocEntry, DefaultFreeEntry -}; - -JS_PUBLIC_API(JSHashTable *) -JS_NewHashTable(uint32 n, JSHashFunction keyHash, - JSHashComparator keyCompare, JSHashComparator valueCompare, - JSHashAllocOps *allocOps, void *allocPriv) -{ - JSHashTable *ht; - size_t nb; - - if (n <= MINBUCKETS) { - n = MINBUCKETSLOG2; - } else { - n = JS_CeilingLog2(n); - if ((int32)n < 0) - return NULL; - } - - if (!allocOps) allocOps = &defaultHashAllocOps; - - ht = (JSHashTable*) allocOps->allocTable(allocPriv, sizeof *ht); - if (!ht) - return NULL; - memset(ht, 0, sizeof *ht); - ht->shift = JS_HASH_BITS - n; - n = JS_BIT(n); - nb = n * sizeof(JSHashEntry *); - ht->buckets = (JSHashEntry**) allocOps->allocTable(allocPriv, nb); - if (!ht->buckets) { - allocOps->freeTable(allocPriv, ht); - return NULL; - } - memset(ht->buckets, 0, nb); - - ht->keyHash = keyHash; - ht->keyCompare = keyCompare; - ht->valueCompare = valueCompare; - ht->allocOps = allocOps; - ht->allocPriv = allocPriv; - return ht; -} - -JS_PUBLIC_API(void) -JS_HashTableDestroy(JSHashTable *ht) -{ - uint32 i, n; - JSHashEntry *he, **hep; - JSHashAllocOps *allocOps = ht->allocOps; - void *allocPriv = ht->allocPriv; - - n = NBUCKETS(ht); - for (i = 0; i < n; i++) { - hep = &ht->buckets[i]; - while ((he = *hep) != NULL) { - *hep = he->next; - allocOps->freeEntry(allocPriv, he, HT_FREE_ENTRY); - } - } -#ifdef DEBUG - memset(ht->buckets, 0xDB, n * sizeof ht->buckets[0]); -#endif - allocOps->freeTable(allocPriv, ht->buckets); -#ifdef DEBUG - memset(ht, 0xDB, sizeof *ht); -#endif - allocOps->freeTable(allocPriv, ht); -} - -/* - * Multiplicative hash, from Knuth 6.4. - */ -#define BUCKET_HEAD(ht, keyHash) \ - (&(ht)->buckets[((keyHash) * JS_GOLDEN_RATIO) >> (ht)->shift]) - -JS_PUBLIC_API(JSHashEntry **) -JS_HashTableRawLookup(JSHashTable *ht, JSHashNumber keyHash, const void *key) -{ - JSHashEntry *he, **hep, **hep0; - -#ifdef HASHMETER - ht->nlookups++; -#endif - hep = hep0 = BUCKET_HEAD(ht, keyHash); - while ((he = *hep) != NULL) { - if (he->keyHash == keyHash && ht->keyCompare(key, he->key)) { - /* Move to front of chain if not already there */ - if (hep != hep0) { - *hep = he->next; - he->next = *hep0; - *hep0 = he; - } - return hep0; - } - hep = &he->next; -#ifdef HASHMETER - ht->nsteps++; -#endif - } - return hep; -} - -static JSBool -Resize(JSHashTable *ht, uint32 newshift) -{ - size_t nb, nentries, i; - JSHashEntry **oldbuckets, *he, *next, **hep; -#ifdef DEBUG - size_t nold = NBUCKETS(ht); -#endif - - JS_ASSERT(newshift < JS_HASH_BITS); - - nb = (size_t)1 << (JS_HASH_BITS - newshift); - - /* Integer overflow protection. */ - if (nb > (size_t)-1 / sizeof(JSHashEntry*)) - return JS_FALSE; - nb *= sizeof(JSHashEntry*); - - oldbuckets = ht->buckets; - ht->buckets = (JSHashEntry**)ht->allocOps->allocTable(ht->allocPriv, nb); - if (!ht->buckets) { - ht->buckets = oldbuckets; - return JS_FALSE; - } - memset(ht->buckets, 0, nb); - - ht->shift = newshift; - nentries = ht->nentries; - - for (i = 0; nentries != 0; i++) { - for (he = oldbuckets[i]; he; he = next) { - JS_ASSERT(nentries != 0); - --nentries; - next = he->next; - hep = BUCKET_HEAD(ht, he->keyHash); - - /* - * Since he comes from the old table, it must be unique and we - * simply add it to the head of bucket chain without chain lookup. - */ - he->next = *hep; - *hep = he; - } - } -#ifdef DEBUG - memset(oldbuckets, 0xDB, nold * sizeof oldbuckets[0]); -#endif - ht->allocOps->freeTable(ht->allocPriv, oldbuckets); - return JS_TRUE; -} - -JS_PUBLIC_API(JSHashEntry *) -JS_HashTableRawAdd(JSHashTable *ht, JSHashEntry **hep, - JSHashNumber keyHash, const void *key, void *value) -{ - uint32 n; - JSHashEntry *he; - - /* Grow the table if it is overloaded */ - n = NBUCKETS(ht); - if (ht->nentries >= OVERLOADED(n)) { - if (!Resize(ht, ht->shift - 1)) - return NULL; -#ifdef HASHMETER - ht->ngrows++; -#endif - hep = JS_HashTableRawLookup(ht, keyHash, key); - } - - /* Make a new key value entry */ - he = ht->allocOps->allocEntry(ht->allocPriv, key); - if (!he) - return NULL; - he->keyHash = keyHash; - he->key = key; - he->value = value; - he->next = *hep; - *hep = he; - ht->nentries++; - return he; -} - -JS_PUBLIC_API(JSHashEntry *) -JS_HashTableAdd(JSHashTable *ht, const void *key, void *value) -{ - JSHashNumber keyHash; - JSHashEntry *he, **hep; - - keyHash = ht->keyHash(key); - hep = JS_HashTableRawLookup(ht, keyHash, key); - if ((he = *hep) != NULL) { - /* Hit; see if values match */ - if (ht->valueCompare(he->value, value)) { - /* key,value pair is already present in table */ - return he; - } - if (he->value) - ht->allocOps->freeEntry(ht->allocPriv, he, HT_FREE_VALUE); - he->value = value; - return he; - } - return JS_HashTableRawAdd(ht, hep, keyHash, key, value); -} - -JS_PUBLIC_API(void) -JS_HashTableRawRemove(JSHashTable *ht, JSHashEntry **hep, JSHashEntry *he) -{ - uint32 n; - - *hep = he->next; - ht->allocOps->freeEntry(ht->allocPriv, he, HT_FREE_ENTRY); - - /* Shrink table if it's underloaded */ - n = NBUCKETS(ht); - if (--ht->nentries < UNDERLOADED(n)) { - Resize(ht, ht->shift + 1); -#ifdef HASHMETER - ht->nshrinks++; -#endif - } -} - -JS_PUBLIC_API(JSBool) -JS_HashTableRemove(JSHashTable *ht, const void *key) -{ - JSHashNumber keyHash; - JSHashEntry *he, **hep; - - keyHash = ht->keyHash(key); - hep = JS_HashTableRawLookup(ht, keyHash, key); - if ((he = *hep) == NULL) - return JS_FALSE; - - /* Hit; remove element */ - JS_HashTableRawRemove(ht, hep, he); - return JS_TRUE; -} - -JS_PUBLIC_API(void *) -JS_HashTableLookup(JSHashTable *ht, const void *key) -{ - JSHashNumber keyHash; - JSHashEntry *he, **hep; - - keyHash = ht->keyHash(key); - hep = JS_HashTableRawLookup(ht, keyHash, key); - if ((he = *hep) != NULL) { - return he->value; - } - return NULL; -} - -/* -** Iterate over the entries in the hash table calling func for each -** entry found. Stop if "f" says to (return value & JS_ENUMERATE_STOP). -** Return a count of the number of elements scanned. -*/ -JS_PUBLIC_API(int) -JS_HashTableEnumerateEntries(JSHashTable *ht, JSHashEnumerator f, void *arg) -{ - JSHashEntry *he, **hep, **bucket; - uint32 nlimit, n, nbuckets, newlog2; - int rv; - - nlimit = ht->nentries; - n = 0; - for (bucket = ht->buckets; n != nlimit; ++bucket) { - hep = bucket; - while ((he = *hep) != NULL) { - JS_ASSERT(n < nlimit); - rv = f(he, n, arg); - n++; - if (rv & HT_ENUMERATE_REMOVE) { - *hep = he->next; - ht->allocOps->freeEntry(ht->allocPriv, he, HT_FREE_ENTRY); - --ht->nentries; - } else { - hep = &he->next; - } - if (rv & HT_ENUMERATE_STOP) { - goto out; - } - } - } - -out: - /* Shrink table if removal of entries made it underloaded */ - if (ht->nentries != nlimit) { - JS_ASSERT(ht->nentries < nlimit); - nbuckets = NBUCKETS(ht); - if (MINBUCKETS < nbuckets && ht->nentries < UNDERLOADED(nbuckets)) { - newlog2 = JS_CeilingLog2(ht->nentries); - if (newlog2 < MINBUCKETSLOG2) - newlog2 = MINBUCKETSLOG2; - - /* Check that we really shrink the table. */ - JS_ASSERT(JS_HASH_BITS - ht->shift > newlog2); - Resize(ht, JS_HASH_BITS - newlog2); - } - } - return (int)n; -} - -#ifdef HASHMETER -#include <math.h> -#include <stdio.h> - -JS_PUBLIC_API(void) -JS_HashTableDumpMeter(JSHashTable *ht, JSHashEnumerator dump, FILE *fp) -{ - double sqsum, mean, variance, sigma; - uint32 nchains, nbuckets, nentries; - uint32 i, n, maxChain, maxChainLen; - JSHashEntry *he; - - sqsum = 0; - nchains = 0; - maxChainLen = 0; - nbuckets = NBUCKETS(ht); - for (i = 0; i < nbuckets; i++) { - he = ht->buckets[i]; - if (!he) - continue; - nchains++; - for (n = 0; he; he = he->next) - n++; - sqsum += n * n; - if (n > maxChainLen) { - maxChainLen = n; - maxChain = i; - } - } - nentries = ht->nentries; - mean = (double)nentries / nchains; - variance = nchains * sqsum - nentries * nentries; - if (variance < 0 || nchains == 1) - variance = 0; - else - variance /= nchains * (nchains - 1); - sigma = sqrt(variance); - - fprintf(fp, "\nHash table statistics:\n"); - fprintf(fp, " number of lookups: %u\n", ht->nlookups); - fprintf(fp, " number of entries: %u\n", ht->nentries); - fprintf(fp, " number of grows: %u\n", ht->ngrows); - fprintf(fp, " number of shrinks: %u\n", ht->nshrinks); - fprintf(fp, " mean steps per hash: %g\n", (double)ht->nsteps - / ht->nlookups); - fprintf(fp, "mean hash chain length: %g\n", mean); - fprintf(fp, " standard deviation: %g\n", sigma); - fprintf(fp, " max hash chain length: %u\n", maxChainLen); - fprintf(fp, " max hash chain: [%u]\n", maxChain); - - for (he = ht->buckets[maxChain], i = 0; he; he = he->next, i++) - if (dump(he, i, fp) != HT_ENUMERATE_NEXT) - break; -} -#endif /* HASHMETER */ - -JS_PUBLIC_API(int) -JS_HashTableDump(JSHashTable *ht, JSHashEnumerator dump, FILE *fp) -{ - int count; - - count = JS_HashTableEnumerateEntries(ht, dump, fp); -#ifdef HASHMETER - JS_HashTableDumpMeter(ht, dump, fp); -#endif - return count; -} - -JS_PUBLIC_API(JSHashNumber) -JS_HashString(const void *key) -{ - JSHashNumber h; - const unsigned char *s; - - h = 0; - for (s = (const unsigned char *)key; *s; s++) - h = (h >> (JS_HASH_BITS - 4)) ^ (h << 4) ^ *s; - return h; -} - -JS_PUBLIC_API(int) -JS_CompareValues(const void *v1, const void *v2) -{ - return v1 == v2; -} |