| Index: mozilla/nsprpub/lib/ds/plhash.c
|
| ===================================================================
|
| --- mozilla/nsprpub/lib/ds/plhash.c (revision 191424)
|
| +++ mozilla/nsprpub/lib/ds/plhash.c (working copy)
|
| @@ -1,483 +0,0 @@
|
| -/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
| -/* This Source Code Form is subject to the terms of the Mozilla Public
|
| - * License, v. 2.0. If a copy of the MPL was not distributed with this
|
| - * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
| -
|
| -/*
|
| - * PL hash table package.
|
| - */
|
| -#include "plhash.h"
|
| -#include "prbit.h"
|
| -#include "prlog.h"
|
| -#include "prmem.h"
|
| -#include "prtypes.h"
|
| -#include <stdlib.h>
|
| -#include <string.h>
|
| -
|
| -/* Compute the number of buckets in ht */
|
| -#define NBUCKETS(ht) (1 << (PL_HASH_BITS - (ht)->shift))
|
| -
|
| -/* The smallest table has 16 buckets */
|
| -#define MINBUCKETSLOG2 4
|
| -#define MINBUCKETS (1 << 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 * PR_CALLBACK
|
| -DefaultAllocTable(void *pool, PRSize size)
|
| -{
|
| - return PR_MALLOC(size);
|
| -}
|
| -
|
| -static void PR_CALLBACK
|
| -DefaultFreeTable(void *pool, void *item)
|
| -{
|
| - PR_Free(item);
|
| -}
|
| -
|
| -static PLHashEntry * PR_CALLBACK
|
| -DefaultAllocEntry(void *pool, const void *key)
|
| -{
|
| - return PR_NEW(PLHashEntry);
|
| -}
|
| -
|
| -static void PR_CALLBACK
|
| -DefaultFreeEntry(void *pool, PLHashEntry *he, PRUintn flag)
|
| -{
|
| - if (flag == HT_FREE_ENTRY)
|
| - PR_Free(he);
|
| -}
|
| -
|
| -static PLHashAllocOps defaultHashAllocOps = {
|
| - DefaultAllocTable, DefaultFreeTable,
|
| - DefaultAllocEntry, DefaultFreeEntry
|
| -};
|
| -
|
| -PR_IMPLEMENT(PLHashTable *)
|
| -PL_NewHashTable(PRUint32 n, PLHashFunction keyHash,
|
| - PLHashComparator keyCompare, PLHashComparator valueCompare,
|
| - const PLHashAllocOps *allocOps, void *allocPriv)
|
| -{
|
| - PLHashTable *ht;
|
| - PRSize nb;
|
| -
|
| - if (n <= MINBUCKETS) {
|
| - n = MINBUCKETSLOG2;
|
| - } else {
|
| - n = PR_CeilingLog2(n);
|
| - if ((PRInt32)n < 0)
|
| - return 0;
|
| - }
|
| -
|
| - if (!allocOps) allocOps = &defaultHashAllocOps;
|
| -
|
| - ht = (PLHashTable*)((*allocOps->allocTable)(allocPriv, sizeof *ht));
|
| - if (!ht)
|
| - return 0;
|
| - memset(ht, 0, sizeof *ht);
|
| - ht->shift = PL_HASH_BITS - n;
|
| - n = 1 << n;
|
| - nb = n * sizeof(PLHashEntry *);
|
| - ht->buckets = (PLHashEntry**)((*allocOps->allocTable)(allocPriv, nb));
|
| - if (!ht->buckets) {
|
| - (*allocOps->freeTable)(allocPriv, ht);
|
| - return 0;
|
| - }
|
| - memset(ht->buckets, 0, nb);
|
| -
|
| - ht->keyHash = keyHash;
|
| - ht->keyCompare = keyCompare;
|
| - ht->valueCompare = valueCompare;
|
| - ht->allocOps = allocOps;
|
| - ht->allocPriv = allocPriv;
|
| - return ht;
|
| -}
|
| -
|
| -PR_IMPLEMENT(void)
|
| -PL_HashTableDestroy(PLHashTable *ht)
|
| -{
|
| - PRUint32 i, n;
|
| - PLHashEntry *he, *next;
|
| - const PLHashAllocOps *allocOps = ht->allocOps;
|
| - void *allocPriv = ht->allocPriv;
|
| -
|
| - n = NBUCKETS(ht);
|
| - for (i = 0; i < n; i++) {
|
| - for (he = ht->buckets[i]; he; he = next) {
|
| - next = 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 GOLDEN_RATIO 0x9E3779B9U /* 2/(1+sqrt(5))*(2^32) */
|
| -
|
| -PR_IMPLEMENT(PLHashEntry **)
|
| -PL_HashTableRawLookup(PLHashTable *ht, PLHashNumber keyHash, const void *key)
|
| -{
|
| - PLHashEntry *he, **hep, **hep0;
|
| - PLHashNumber h;
|
| -
|
| -#ifdef HASHMETER
|
| - ht->nlookups++;
|
| -#endif
|
| - h = keyHash * GOLDEN_RATIO;
|
| - h >>= ht->shift;
|
| - hep = hep0 = &ht->buckets[h];
|
| - while ((he = *hep) != 0) {
|
| - 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;
|
| -}
|
| -
|
| -/*
|
| -** Same as PL_HashTableRawLookup but doesn't reorder the hash entries.
|
| -*/
|
| -PR_IMPLEMENT(PLHashEntry **)
|
| -PL_HashTableRawLookupConst(PLHashTable *ht, PLHashNumber keyHash,
|
| - const void *key)
|
| -{
|
| - PLHashEntry *he, **hep;
|
| - PLHashNumber h;
|
| -
|
| -#ifdef HASHMETER
|
| - ht->nlookups++;
|
| -#endif
|
| - h = keyHash * GOLDEN_RATIO;
|
| - h >>= ht->shift;
|
| - hep = &ht->buckets[h];
|
| - while ((he = *hep) != 0) {
|
| - if (he->keyHash == keyHash && (*ht->keyCompare)(key, he->key)) {
|
| - break;
|
| - }
|
| - hep = &he->next;
|
| -#ifdef HASHMETER
|
| - ht->nsteps++;
|
| -#endif
|
| - }
|
| - return hep;
|
| -}
|
| -
|
| -PR_IMPLEMENT(PLHashEntry *)
|
| -PL_HashTableRawAdd(PLHashTable *ht, PLHashEntry **hep,
|
| - PLHashNumber keyHash, const void *key, void *value)
|
| -{
|
| - PRUint32 i, n;
|
| - PLHashEntry *he, *next, **oldbuckets;
|
| - PRSize nb;
|
| -
|
| - /* Grow the table if it is overloaded */
|
| - n = NBUCKETS(ht);
|
| - if (ht->nentries >= OVERLOADED(n)) {
|
| - oldbuckets = ht->buckets;
|
| - nb = 2 * n * sizeof(PLHashEntry *);
|
| - ht->buckets = (PLHashEntry**)
|
| - ((*ht->allocOps->allocTable)(ht->allocPriv, nb));
|
| - if (!ht->buckets) {
|
| - ht->buckets = oldbuckets;
|
| - return 0;
|
| - }
|
| - memset(ht->buckets, 0, nb);
|
| -#ifdef HASHMETER
|
| - ht->ngrows++;
|
| -#endif
|
| - ht->shift--;
|
| -
|
| - for (i = 0; i < n; i++) {
|
| - for (he = oldbuckets[i]; he; he = next) {
|
| - next = he->next;
|
| - hep = PL_HashTableRawLookup(ht, he->keyHash, he->key);
|
| - PR_ASSERT(*hep == 0);
|
| - he->next = 0;
|
| - *hep = he;
|
| - }
|
| - }
|
| -#ifdef DEBUG
|
| - memset(oldbuckets, 0xDB, n * sizeof oldbuckets[0]);
|
| -#endif
|
| - (*ht->allocOps->freeTable)(ht->allocPriv, oldbuckets);
|
| - hep = PL_HashTableRawLookup(ht, keyHash, key);
|
| - }
|
| -
|
| - /* Make a new key value entry */
|
| - he = (*ht->allocOps->allocEntry)(ht->allocPriv, key);
|
| - if (!he)
|
| - return 0;
|
| - he->keyHash = keyHash;
|
| - he->key = key;
|
| - he->value = value;
|
| - he->next = *hep;
|
| - *hep = he;
|
| - ht->nentries++;
|
| - return he;
|
| -}
|
| -
|
| -PR_IMPLEMENT(PLHashEntry *)
|
| -PL_HashTableAdd(PLHashTable *ht, const void *key, void *value)
|
| -{
|
| - PLHashNumber keyHash;
|
| - PLHashEntry *he, **hep;
|
| -
|
| - keyHash = (*ht->keyHash)(key);
|
| - hep = PL_HashTableRawLookup(ht, keyHash, key);
|
| - if ((he = *hep) != 0) {
|
| - /* 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 PL_HashTableRawAdd(ht, hep, keyHash, key, value);
|
| -}
|
| -
|
| -PR_IMPLEMENT(void)
|
| -PL_HashTableRawRemove(PLHashTable *ht, PLHashEntry **hep, PLHashEntry *he)
|
| -{
|
| - PRUint32 i, n;
|
| - PLHashEntry *next, **oldbuckets;
|
| - PRSize nb;
|
| -
|
| - *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)) {
|
| - oldbuckets = ht->buckets;
|
| - nb = n * sizeof(PLHashEntry*) / 2;
|
| - ht->buckets = (PLHashEntry**)(
|
| - (*ht->allocOps->allocTable)(ht->allocPriv, nb));
|
| - if (!ht->buckets) {
|
| - ht->buckets = oldbuckets;
|
| - return;
|
| - }
|
| - memset(ht->buckets, 0, nb);
|
| -#ifdef HASHMETER
|
| - ht->nshrinks++;
|
| -#endif
|
| - ht->shift++;
|
| -
|
| - for (i = 0; i < n; i++) {
|
| - for (he = oldbuckets[i]; he; he = next) {
|
| - next = he->next;
|
| - hep = PL_HashTableRawLookup(ht, he->keyHash, he->key);
|
| - PR_ASSERT(*hep == 0);
|
| - he->next = 0;
|
| - *hep = he;
|
| - }
|
| - }
|
| -#ifdef DEBUG
|
| - memset(oldbuckets, 0xDB, n * sizeof oldbuckets[0]);
|
| -#endif
|
| - (*ht->allocOps->freeTable)(ht->allocPriv, oldbuckets);
|
| - }
|
| -}
|
| -
|
| -PR_IMPLEMENT(PRBool)
|
| -PL_HashTableRemove(PLHashTable *ht, const void *key)
|
| -{
|
| - PLHashNumber keyHash;
|
| - PLHashEntry *he, **hep;
|
| -
|
| - keyHash = (*ht->keyHash)(key);
|
| - hep = PL_HashTableRawLookup(ht, keyHash, key);
|
| - if ((he = *hep) == 0)
|
| - return PR_FALSE;
|
| -
|
| - /* Hit; remove element */
|
| - PL_HashTableRawRemove(ht, hep, he);
|
| - return PR_TRUE;
|
| -}
|
| -
|
| -PR_IMPLEMENT(void *)
|
| -PL_HashTableLookup(PLHashTable *ht, const void *key)
|
| -{
|
| - PLHashNumber keyHash;
|
| - PLHashEntry *he, **hep;
|
| -
|
| - keyHash = (*ht->keyHash)(key);
|
| - hep = PL_HashTableRawLookup(ht, keyHash, key);
|
| - if ((he = *hep) != 0) {
|
| - return he->value;
|
| - }
|
| - return 0;
|
| -}
|
| -
|
| -/*
|
| -** Same as PL_HashTableLookup but doesn't reorder the hash entries.
|
| -*/
|
| -PR_IMPLEMENT(void *)
|
| -PL_HashTableLookupConst(PLHashTable *ht, const void *key)
|
| -{
|
| - PLHashNumber keyHash;
|
| - PLHashEntry *he, **hep;
|
| -
|
| - keyHash = (*ht->keyHash)(key);
|
| - hep = PL_HashTableRawLookupConst(ht, keyHash, key);
|
| - if ((he = *hep) != 0) {
|
| - return he->value;
|
| - }
|
| - return 0;
|
| -}
|
| -
|
| -/*
|
| -** Iterate over the entries in the hash table calling func for each
|
| -** entry found. Stop if "f" says to (return value & PR_ENUMERATE_STOP).
|
| -** Return a count of the number of elements scanned.
|
| -*/
|
| -PR_IMPLEMENT(int)
|
| -PL_HashTableEnumerateEntries(PLHashTable *ht, PLHashEnumerator f, void *arg)
|
| -{
|
| - PLHashEntry *he, **hep;
|
| - PRUint32 i, nbuckets;
|
| - int rv, n = 0;
|
| - PLHashEntry *todo = 0;
|
| -
|
| - nbuckets = NBUCKETS(ht);
|
| - for (i = 0; i < nbuckets; i++) {
|
| - hep = &ht->buckets[i];
|
| - while ((he = *hep) != 0) {
|
| - rv = (*f)(he, n, arg);
|
| - n++;
|
| - if (rv & (HT_ENUMERATE_REMOVE | HT_ENUMERATE_UNHASH)) {
|
| - *hep = he->next;
|
| - if (rv & HT_ENUMERATE_REMOVE) {
|
| - he->next = todo;
|
| - todo = he;
|
| - }
|
| - } else {
|
| - hep = &he->next;
|
| - }
|
| - if (rv & HT_ENUMERATE_STOP) {
|
| - goto out;
|
| - }
|
| - }
|
| - }
|
| -
|
| -out:
|
| - hep = &todo;
|
| - while ((he = *hep) != 0) {
|
| - PL_HashTableRawRemove(ht, hep, he);
|
| - }
|
| - return n;
|
| -}
|
| -
|
| -#ifdef HASHMETER
|
| -#include <math.h>
|
| -#include <stdio.h>
|
| -
|
| -PR_IMPLEMENT(void)
|
| -PL_HashTableDumpMeter(PLHashTable *ht, PLHashEnumerator dump, FILE *fp)
|
| -{
|
| - double mean, variance;
|
| - PRUint32 nchains, nbuckets;
|
| - PRUint32 i, n, maxChain, maxChainLen;
|
| - PLHashEntry *he;
|
| -
|
| - variance = 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++;
|
| - variance += n * n;
|
| - if (n > maxChainLen) {
|
| - maxChainLen = n;
|
| - maxChain = i;
|
| - }
|
| - }
|
| - mean = (double)ht->nentries / nchains;
|
| - variance = fabs(variance / nchains - mean * mean);
|
| -
|
| - 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", sqrt(variance));
|
| - 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 */
|
| -
|
| -PR_IMPLEMENT(int)
|
| -PL_HashTableDump(PLHashTable *ht, PLHashEnumerator dump, FILE *fp)
|
| -{
|
| - int count;
|
| -
|
| - count = PL_HashTableEnumerateEntries(ht, dump, fp);
|
| -#ifdef HASHMETER
|
| - PL_HashTableDumpMeter(ht, dump, fp);
|
| -#endif
|
| - return count;
|
| -}
|
| -
|
| -PR_IMPLEMENT(PLHashNumber)
|
| -PL_HashString(const void *key)
|
| -{
|
| - PLHashNumber h;
|
| - const PRUint8 *s;
|
| -
|
| - h = 0;
|
| - for (s = (const PRUint8*)key; *s; s++)
|
| - h = PR_ROTATE_LEFT32(h, 4) ^ *s;
|
| - return h;
|
| -}
|
| -
|
| -PR_IMPLEMENT(int)
|
| -PL_CompareStrings(const void *v1, const void *v2)
|
| -{
|
| - return strcmp((const char*)v1, (const char*)v2) == 0;
|
| -}
|
| -
|
| -PR_IMPLEMENT(int)
|
| -PL_CompareValues(const void *v1, const void *v2)
|
| -{
|
| - return v1 == v2;
|
| -}
|
|
|