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/* -*- 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/. */
#ifndef plhash_h___
#define plhash_h___
/*
* API to portable hash table code.
*/
#include <stdio.h>
#include "prtypes.h"
PR_BEGIN_EXTERN_C
typedef struct PLHashEntry PLHashEntry;
typedef struct PLHashTable PLHashTable;
typedef PRUint32 PLHashNumber;
#define PL_HASH_BITS 32 /* Number of bits in PLHashNumber */
typedef PLHashNumber (PR_CALLBACK *PLHashFunction)(const void *key);
typedef PRIntn (PR_CALLBACK *PLHashComparator)(const void *v1, const void *v2);
typedef PRIntn (PR_CALLBACK *PLHashEnumerator)(PLHashEntry *he, PRIntn i, void *arg);
/* Flag bits in PLHashEnumerator's return value */
#define HT_ENUMERATE_NEXT 0 /* continue enumerating entries */
#define HT_ENUMERATE_STOP 1 /* stop enumerating entries */
#define HT_ENUMERATE_REMOVE 2 /* remove and free the current entry */
#define HT_ENUMERATE_UNHASH 4 /* just unhash the current entry */
typedef struct PLHashAllocOps {
void * (PR_CALLBACK *allocTable)(void *pool, PRSize size);
void (PR_CALLBACK *freeTable)(void *pool, void *item);
PLHashEntry * (PR_CALLBACK *allocEntry)(void *pool, const void *key);
void (PR_CALLBACK *freeEntry)(void *pool, PLHashEntry *he, PRUintn flag);
} PLHashAllocOps;
#define HT_FREE_VALUE 0 /* just free the entry's value */
#define HT_FREE_ENTRY 1 /* free value and entire entry */
struct PLHashEntry {
PLHashEntry *next; /* hash chain linkage */
PLHashNumber keyHash; /* key hash function result */
const void *key; /* ptr to opaque key */
void *value; /* ptr to opaque value */
};
struct PLHashTable {
PLHashEntry **buckets; /* vector of hash buckets */
PRUint32 nentries; /* number of entries in table */
PRUint32 shift; /* multiplicative hash shift */
PLHashFunction keyHash; /* key hash function */
PLHashComparator keyCompare; /* key comparison function */
PLHashComparator valueCompare; /* value comparison function */
const PLHashAllocOps *allocOps; /* allocation operations */
void *allocPriv; /* allocation private data */
#ifdef HASHMETER
PRUint32 nlookups; /* total number of lookups */
PRUint32 nsteps; /* number of hash chains traversed */
PRUint32 ngrows; /* number of table expansions */
PRUint32 nshrinks; /* number of table contractions */
#endif
};
/*
* Create a new hash table.
* If allocOps is null, use default allocator ops built on top of malloc().
*/
PR_EXTERN(PLHashTable *)
PL_NewHashTable(PRUint32 numBuckets, PLHashFunction keyHash,
PLHashComparator keyCompare, PLHashComparator valueCompare,
const PLHashAllocOps *allocOps, void *allocPriv);
PR_EXTERN(void)
PL_HashTableDestroy(PLHashTable *ht);
/* Higher level access methods */
PR_EXTERN(PLHashEntry *)
PL_HashTableAdd(PLHashTable *ht, const void *key, void *value);
PR_EXTERN(PRBool)
PL_HashTableRemove(PLHashTable *ht, const void *key);
PR_EXTERN(void *)
PL_HashTableLookup(PLHashTable *ht, const void *key);
PR_EXTERN(void *)
PL_HashTableLookupConst(PLHashTable *ht, const void *key);
PR_EXTERN(PRIntn)
PL_HashTableEnumerateEntries(PLHashTable *ht, PLHashEnumerator f, void *arg);
/* General-purpose C string hash function. */
PR_EXTERN(PLHashNumber)
PL_HashString(const void *key);
/* Compare strings using strcmp(), return true if equal. */
PR_EXTERN(PRIntn)
PL_CompareStrings(const void *v1, const void *v2);
/* Stub function just returns v1 == v2 */
PR_EXTERN(PRIntn)
PL_CompareValues(const void *v1, const void *v2);
/* Low level access methods */
PR_EXTERN(PLHashEntry **)
PL_HashTableRawLookup(PLHashTable *ht, PLHashNumber keyHash, const void *key);
PR_EXTERN(PLHashEntry **)
PL_HashTableRawLookupConst(PLHashTable *ht, PLHashNumber keyHash,
const void *key);
PR_EXTERN(PLHashEntry *)
PL_HashTableRawAdd(PLHashTable *ht, PLHashEntry **hep, PLHashNumber keyHash,
const void *key, void *value);
PR_EXTERN(void)
PL_HashTableRawRemove(PLHashTable *ht, PLHashEntry **hep, PLHashEntry *he);
/* This can be trivially implemented using PL_HashTableEnumerateEntries. */
PR_EXTERN(PRIntn)
PL_HashTableDump(PLHashTable *ht, PLHashEnumerator dump, FILE *fp);
PR_END_EXTERN_C
#endif /* plhash_h___ */
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