1 /* Hash table 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) 2006-2010, 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 static unsigned int dictGenHashFunction(const unsigned char *buf, int len); 115 static dict *dictCreate(dictType *type, void *privDataPtr); 116 static int dictExpand(dict *ht, unsigned long size); 117 static int dictAdd(dict *ht, void *key, void *val); 118 static int dictReplace(dict *ht, void *key, void *val); 119 static int dictDelete(dict *ht, const void *key); 120 static void dictRelease(dict *ht); 121 static dictEntry * dictFind(dict *ht, const void *key); 122 static dictIterator *dictGetIterator(dict *ht); 123 static dictEntry *dictNext(dictIterator *iter); 124 static void dictReleaseIterator(dictIterator *iter); 125 126 #endif /* __DICT_H */ 127