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
  45 typedef struct dictEntry {
  46     void *key;
  47     void *val;
  48     struct dictEntry *next;
  49 } dictEntry;
  50
  51 typedef 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
  60 typedef struct dict {
  61     dictEntry **table;
  62     dictType *type;
  63     unsigned long size;
  64     unsigned long sizemask;
  65     unsigned long used;
  66     void *privdata;
  67 } dict;
  68
  69 typedef 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     4
  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 dictSlots(ht) ((ht)->size)
 111 #define dictSize(ht) ((ht)->used)
 112
 113 /* API */
 114 dict *dictCreate(dictType *type, void *privDataPtr);
 115 int dictExpand(dict *ht, unsigned long size);
 116 int dictAdd(dict *ht, void *key, void *val);
 117 int dictReplace(dict *ht, void *key, void *val);
 118 int dictDelete(dict *ht, const void *key);
 119 int dictDeleteNoFree(dict *ht, const void *key);
 120 void dictRelease(dict *ht);
 121 dictEntry * dictFind(dict *ht, const void *key);
 122 int dictResize(dict *ht);
 123 dictIterator *dictGetIterator(dict *ht);
 124 dictEntry *dictNext(dictIterator *iter);
 125 void dictReleaseIterator(dictIterator *iter);
 126 dictEntry *dictGetRandomKey(dict *ht);
 127 void dictPrintStats(dict *ht);
 128 unsigned int dictGenHashFunction(const unsigned char *buf, int len);
 129 void dictEmpty(dict *ht);
 130
 131 /* Hash table types */
 132 extern dictType dictTypeHeapStringCopyKey;
 133 extern dictType dictTypeHeapStrings;
 134 extern dictType dictTypeHeapStringCopyKeyValue;
 135
 136 #endif /* __DICT_H */