pjs/js/src/jshash.h

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C

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#ifndef jshash_h___
#define jshash_h___
/*
* API to portable hash table code.
*/
#include <stddef.h>
#include <stdio.h>
#include "jstypes.h"
#include "jscompat.h"
JS_BEGIN_EXTERN_C
typedef uint32 JSHashNumber;
typedef struct JSHashEntry JSHashEntry;
typedef struct JSHashTable JSHashTable;
#define JS_HASH_BITS 32
#define JS_GOLDEN_RATIO 0x9E3779B9U
typedef JSHashNumber (*JSHashFunction)(const void *key);
typedef intN (*JSHashComparator)(const void *v1, const void *v2);
typedef intN (*JSHashEnumerator)(JSHashEntry *he, intN i, void *arg);
/* Flag bits in JSHashEnumerator'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 JSHashAllocOps {
void * (*allocTable)(void *pool, size_t size);
void (*freeTable)(void *pool, void *item);
JSHashEntry * (*allocEntry)(void *pool, const void *key);
void (*freeEntry)(void *pool, JSHashEntry *he, uintN flag);
} JSHashAllocOps;
#define HT_FREE_VALUE 0 /* just free the entry's value */
#define HT_FREE_ENTRY 1 /* free value and entire entry */
struct JSHashEntry {
JSHashEntry *next; /* hash chain linkage */
JSHashNumber keyHash; /* key hash function result */
const void *key; /* ptr to opaque key */
void *value; /* ptr to opaque value */
};
struct JSHashTable {
JSHashEntry **buckets; /* vector of hash buckets */
uint32 nentries; /* number of entries in table */
uint32 shift; /* multiplicative hash shift */
JSHashFunction keyHash; /* key hash function */
JSHashComparator keyCompare; /* key comparison function */
JSHashComparator valueCompare; /* value comparison function */
JSHashAllocOps *allocOps; /* allocation operations */
void *allocPriv; /* allocation private data */
#ifdef HASHMETER
uint32 nlookups; /* total number of lookups */
uint32 nsteps; /* number of hash chains traversed */
uint32 ngrows; /* number of table expansions */
uint32 nshrinks; /* number of table contractions */
#endif
};
/*
* Create a new hash table.
* If allocOps is null, use default allocator ops built on top of malloc().
*/
JS_EXTERN_API(JSHashTable *)
JS_NewHashTable(uint32 n, JSHashFunction keyHash,
JSHashComparator keyCompare, JSHashComparator valueCompare,
JSHashAllocOps *allocOps, void *allocPriv);
JS_EXTERN_API(void)
JS_HashTableDestroy(JSHashTable *ht);
/* Low level access methods */
JS_EXTERN_API(JSHashEntry **)
JS_HashTableRawLookup(JSHashTable *ht, JSHashNumber keyHash, const void *key);
JS_EXTERN_API(JSHashEntry *)
JS_HashTableRawAdd(JSHashTable *ht, JSHashEntry **hep, JSHashNumber keyHash,
const void *key, void *value);
JS_EXTERN_API(void)
JS_HashTableRawRemove(JSHashTable *ht, JSHashEntry **hep, JSHashEntry *he);
/* Higher level access methods */
JS_EXTERN_API(JSHashEntry *)
JS_HashTableAdd(JSHashTable *ht, const void *key, void *value);
JS_EXTERN_API(JSBool)
JS_HashTableRemove(JSHashTable *ht, const void *key);
JS_EXTERN_API(intN)
JS_HashTableEnumerateEntries(JSHashTable *ht, JSHashEnumerator f, void *arg);
JS_EXTERN_API(void *)
JS_HashTableLookup(JSHashTable *ht, const void *key);
JS_EXTERN_API(intN)
JS_HashTableDump(JSHashTable *ht, JSHashEnumerator dump, FILE *fp);
/* General-purpose C string hash function. */
JS_EXTERN_API(JSHashNumber)
JS_HashString(const void *key);
/* Stub function just returns v1 == v2 */
JS_EXTERN_API(intN)
JS_CompareValues(const void *v1, const void *v2);
JS_END_EXTERN_C
#endif /* jshash_h___ */