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; |
-} |