/dict.h

  1/* Hash Tables Implementation.
  2 *
  3 * This file implements in memory hash tables with insert/del/replace/find/
  4 * get-random-element operations. Hash tables will auto resize if needed
  5 * tables of power of two in size are used, collisions are handled by
  6 * chaining. See the source code for more information... :)
  7 *
  8 * Copyright (c) 2006-2009, Salvatore Sanfilippo <antirez at gmail dot com>
  9 * All rights reserved.
 10 *
 11 * Redistribution and use in source and binary forms, with or without
 12 * modification, are permitted provided that the following conditions are met:
 13 *
 14 *   * Redistributions of source code must retain the above copyright notice,
 15 *     this list of conditions and the following disclaimer.
 16 *   * Redistributions in binary form must reproduce the above copyright
 17 *     notice, this list of conditions and the following disclaimer in the
 18 *     documentation and/or other materials provided with the distribution.
 19 *   * Neither the name of Redis nor the names of its contributors may be used
 20 *     to endorse or promote products derived from this software without
 21 *     specific prior written permission.
 22 *
 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 24 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 33 * POSSIBILITY OF SUCH DAMAGE.
 34 */
 35
 36#ifndef __DICT_H
 37#define __DICT_H
 38
 39#define DICT_OK 0
 40#define DICT_ERR 1
 41
 42/* Unused arguments generate annoying warnings... */
 43#define DICT_NOTUSED(V) ((void) V)
 44
 45typedef struct dictEntry {
 46    void *key;
 47    void *val;
 48    struct dictEntry *next;
 49} dictEntry;
 50
 51typedef struct dictType {
 52    unsigned int (*hashFunction)(const void *key);
 53    void *(*keyDup)(void *privdata, const void *key);
 54    void *(*valDup)(void *privdata, const void *obj);
 55    int (*keyCompare)(void *privdata, const void *key1, const void *key2);
 56    void (*keyDestructor)(void *privdata, void *key);
 57    void (*valDestructor)(void *privdata, void *obj);
 58} dictType;
 59
 60typedef struct dict {
 61    dictEntry **table;
 62    dictType *type;
 63    unsigned int size;
 64    unsigned int sizemask;
 65    unsigned int used;
 66    void *privdata;
 67} dict;
 68
 69typedef struct dictIterator {
 70    dict *ht;
 71    int index;
 72    dictEntry *entry, *nextEntry;
 73} dictIterator;
 74
 75/* This is the initial size of every hash table */
 76#define DICT_HT_INITIAL_SIZE     16
 77
 78/* ------------------------------- Macros ------------------------------------*/
 79#define dictFreeEntryVal(ht, entry) \
 80    if ((ht)->type->valDestructor) \
 81        (ht)->type->valDestructor((ht)->privdata, (entry)->val)
 82
 83#define dictSetHashVal(ht, entry, _val_) do { \
 84    if ((ht)->type->valDup) \
 85        entry->val = (ht)->type->valDup((ht)->privdata, _val_); \
 86    else \
 87        entry->val = (_val_); \
 88} while(0)
 89
 90#define dictFreeEntryKey(ht, entry) \
 91    if ((ht)->type->keyDestructor) \
 92        (ht)->type->keyDestructor((ht)->privdata, (entry)->key)
 93
 94#define dictSetHashKey(ht, entry, _key_) do { \
 95    if ((ht)->type->keyDup) \
 96        entry->key = (ht)->type->keyDup((ht)->privdata, _key_); \
 97    else \
 98        entry->key = (_key_); \
 99} while(0)
100
101#define dictCompareHashKeys(ht, key1, key2) \
102    (((ht)->type->keyCompare) ? \
103        (ht)->type->keyCompare((ht)->privdata, key1, key2) : \
104        (key1) == (key2))
105
106#define dictHashKey(ht, key) (ht)->type->hashFunction(key)
107
108#define dictGetEntryKey(he) ((he)->key)
109#define dictGetEntryVal(he) ((he)->val)
110#define dictGetHashTableSize(ht) ((ht)->size)
111#define dictGetHashTableUsed(ht) ((ht)->used)
112
113/* API */
114dict *dictCreate(dictType *type, void *privDataPtr);
115int dictExpand(dict *ht, unsigned int size);
116int dictAdd(dict *ht, void *key, void *val);
117int dictReplace(dict *ht, void *key, void *val);
118int dictDelete(dict *ht, const void *key);
119int dictDeleteNoFree(dict *ht, const void *key);
120void dictRelease(dict *ht);
121dictEntry * dictFind(dict *ht, const void *key);
122int dictResize(dict *ht);
123dictIterator *dictGetIterator(dict *ht);
124dictEntry *dictNext(dictIterator *iter);
125void dictReleaseIterator(dictIterator *iter);
126dictEntry *dictGetRandomKey(dict *ht);
127void dictPrintStats(dict *ht);
128unsigned int dictGenHashFunction(const unsigned char *buf, int len);
129void dictEmpty(dict *ht);
130
131/* Hash table types */
132extern dictType dictTypeHeapStringCopyKey;
133extern dictType dictTypeHeapStrings;
134extern dictType dictTypeHeapStringCopyKeyValue;
135
136#endif /* __DICT_H */