gecko/js/src/jshash.h
2009-07-16 13:33:46 -07:00

154 lines
5.8 KiB
C

/* -*- 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 ***** */
#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 */
typedef struct JSHashAllocOps {
void * (*allocTable)(void *pool, size_t size);
void (*freeTable)(void *pool, void *item, size_t size);
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 JS_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().
*/
extern JS_PUBLIC_API(JSHashTable *)
JS_NewHashTable(uint32 n, JSHashFunction keyHash,
JSHashComparator keyCompare, JSHashComparator valueCompare,
JSHashAllocOps *allocOps, void *allocPriv);
extern JS_PUBLIC_API(void)
JS_HashTableDestroy(JSHashTable *ht);
/* Low level access methods */
extern JS_PUBLIC_API(JSHashEntry **)
JS_HashTableRawLookup(JSHashTable *ht, JSHashNumber keyHash, const void *key);
#ifdef __cplusplus
extern JS_PUBLIC_API(JSHashEntry *)
JS_HashTableRawAdd(JSHashTable *ht, JSHashEntry **&hep, JSHashNumber keyHash,
const void *key, void *value);
#endif
extern JS_PUBLIC_API(void)
JS_HashTableRawRemove(JSHashTable *ht, JSHashEntry **hep, JSHashEntry *he);
/* Higher level access methods */
extern JS_PUBLIC_API(JSHashEntry *)
JS_HashTableAdd(JSHashTable *ht, const void *key, void *value);
extern JS_PUBLIC_API(JSBool)
JS_HashTableRemove(JSHashTable *ht, const void *key);
extern JS_PUBLIC_API(intN)
JS_HashTableEnumerateEntries(JSHashTable *ht, JSHashEnumerator f, void *arg);
extern JS_PUBLIC_API(void *)
JS_HashTableLookup(JSHashTable *ht, const void *key);
extern JS_PUBLIC_API(intN)
JS_HashTableDump(JSHashTable *ht, JSHashEnumerator dump, FILE *fp);
/* General-purpose C string hash function. */
extern JS_PUBLIC_API(JSHashNumber)
JS_HashString(const void *key);
/* Stub function just returns v1 == v2 */
extern JS_PUBLIC_API(intN)
JS_CompareValues(const void *v1, const void *v2);
JS_END_EXTERN_C
#endif /* jshash_h___ */