jshash.h
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* 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 jshash_h___
#define jshash_h___
/*
* API to portable hash table code.
*/
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
extern "C" {
typedef uint32_t 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 int (* JSHashComparator)(const void *v1, const void *v2);
typedef int (* JSHashEnumerator)(JSHashEntry *he, int 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, unsigned 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_t nentries; /* number of entries in table */
uint32_t shift; /* multiplicative hash shift */
JSHashFunction keyHash; /* key hash function */
JSHashComparator keyCompare; /* key comparison function */
JSHashComparator valueCompare; /* value comparison function */
const JSHashAllocOps *allocOps; /* allocation operations */
void *allocPriv; /* allocation private data */
#ifdef JS_HASHMETER
uint32_t nlookups; /* total number of lookups */
uint32_t nsteps; /* number of hash chains traversed */
uint32_t ngrows; /* number of table expansions */
uint32_t 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 JSHashTable *
JS_NewHashTable(uint32_t n, JSHashFunction keyHash,
JSHashComparator keyCompare, JSHashComparator valueCompare,
const JSHashAllocOps *allocOps, void *allocPriv);
extern void
JS_HashTableDestroy(JSHashTable *ht);
/* Low level access methods */
extern JSHashEntry **
JS_HashTableRawLookup(JSHashTable *ht, JSHashNumber keyHash, const void *key);
extern JSHashEntry *
JS_HashTableRawAdd(JSHashTable *ht, JSHashEntry **&hep, JSHashNumber keyHash,
const void *key, void *value);
extern void
JS_HashTableRawRemove(JSHashTable *ht, JSHashEntry **hep, JSHashEntry *he);
/* Higher level access methods */
extern JSHashEntry *
JS_HashTableAdd(JSHashTable *ht, const void *key, void *value);
extern bool
JS_HashTableRemove(JSHashTable *ht, const void *key);
extern int
JS_HashTableEnumerateEntries(JSHashTable *ht, JSHashEnumerator f, void *arg);
extern void *
JS_HashTableLookup(JSHashTable *ht, const void *key);
extern int
JS_HashTableDump(JSHashTable *ht, JSHashEnumerator dump, FILE *fp);
/* General-purpose C string hash function. */
extern JSHashNumber
JS_HashString(const void *key);
/* Stub function just returns v1 == v2 */
extern int
JS_CompareValues(const void *v1, const void *v2);
} // extern "C"
#endif /* jshash_h___ */