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) 2006-2010, 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 #include <stdint.h> 37 38 #ifndef __DICT_H 39 #define __DICT_H 40 41 #define DICT_OK 0 42 #define DICT_ERR 1 43 44 /* Unused arguments generate annoying warnings... */ 45 #define DICT_NOTUSED(V) ((void) V) 46 47 typedef struct dictEntry { 48 void *key; 49 union { 50 void *val; 51 uint64_t u64; 52 int64_t s64; 53 } v; 54 struct dictEntry *next; 55 } dictEntry; 56 57 typedef struct dictType { 58 unsigned int (*hashFunction)(const void *key); 59 void *(*keyDup)(void *privdata, const void *key); 60 void *(*valDup)(void *privdata, const void *obj); 61 int (*keyCompare)(void *privdata, const void *key1, const void *key2); 62 void (*keyDestructor)(void *privdata, void *key); 63 void (*valDestructor)(void *privdata, void *obj); 64 } dictType; 65 66 /* This is our hash table structure. Every dictionary has two of this as we 67 * implement incremental rehashing, for the old to the new table. */ 68 typedef struct dictht { 69 dictEntry **table; 70 unsigned long size; 71 unsigned long sizemask; 72 unsigned long used; 73 } dictht; 74 75 typedef struct dict { 76 dictType *type; 77 void *privdata; 78 dictht ht[2]; 79 int rehashidx; /* rehashing not in progress if rehashidx == -1 */ 80 int iterators; /* number of iterators currently running */ 81 } dict; 82 83 /* If safe is set to 1 this is a safe iteartor, that means, you can call 84 * dictAdd, dictFind, and other functions against the dictionary even while 85 * iterating. Otherwise it is a non safe iterator, and only dictNext() 86 * should be called while iterating. */ 87 typedef struct dictIterator { 88 dict *d; 89 int table, index, safe; 90 dictEntry *entry, *nextEntry; 91 } dictIterator; 92 93 /* This is the initial size of every hash table */ 94 #define DICT_HT_INITIAL_SIZE 4 95 96 /* ------------------------------- Macros ------------------------------------*/ 97 #define dictFreeVal(d, entry) \ 98 if ((d)->type->valDestructor) \ 99 (d)->type->valDestructor((d)->privdata, (entry)->v.val) 100 101 #define dictSetVal(d, entry, _val_) do { \ 102 if ((d)->type->valDup) \ 103 entry->v.val = (d)->type->valDup((d)->privdata, _val_); \ 104 else \ 105 entry->v.val = (_val_); \ 106 } while(0) 107 108 #define dictSetSignedIntegerVal(entry, _val_) \ 109 do { entry->v.s64 = _val_; } while(0) 110 111 #define dictSetUnsignedIntegerVal(entry, _val_) \ 112 do { entry->v.u64 = _val_; } while(0) 113 114 #define dictFreeKey(d, entry) \ 115 if ((d)->type->keyDestructor) \ 116 (d)->type->keyDestructor((d)->privdata, (entry)->key) 117 118 #define dictSetKey(d, entry, _key_) do { \ 119 if ((d)->type->keyDup) \ 120 entry->key = (d)->type->keyDup((d)->privdata, _key_); \ 121 else \ 122 entry->key = (_key_); \ 123 } while(0) 124 125 #define dictCompareKeys(d, key1, key2) \ 126 (((d)->type->keyCompare) ? \ 127 (d)->type->keyCompare((d)->privdata, key1, key2) : \ 128 (key1) == (key2)) 129 130 #define dictHashKey(d, key) (d)->type->hashFunction(key) 131 #define dictGetKey(he) ((he)->key) 132 #define dictGetVal(he) ((he)->v.val) 133 #define dictGetSignedIntegerVal(he) ((he)->v.s64) 134 #define dictGetUnsignedIntegerVal(he) ((he)->v.u64) 135 #define dictSlots(d) ((d)->ht[0].size+(d)->ht[1].size) 136 #define dictSize(d) ((d)->ht[0].used+(d)->ht[1].used) 137 #define dictIsRehashing(ht) ((ht)->rehashidx != -1) 138 139 /* API */ 140 dict *dictCreate(dictType *type, void *privDataPtr); 141 int dictExpand(dict *d, unsigned long size); 142 int dictAdd(dict *d, void *key, void *val); 143 dictEntry *dictAddRaw(dict *d, void *key); 144 int dictReplace(dict *d, void *key, void *val); 145 dictEntry *dictReplaceRaw(dict *d, void *key); 146 int dictDelete(dict *d, const void *key); 147 int dictDeleteNoFree(dict *d, const void *key); 148 void dictRelease(dict *d); 149 dictEntry * dictFind(dict *d, const void *key); 150 void *dictFetchValue(dict *d, const void *key); 151 int dictResize(dict *d); 152 dictIterator *dictGetIterator(dict *d); 153 dictIterator *dictGetSafeIterator(dict *d); 154 dictEntry *dictNext(dictIterator *iter); 155 void dictReleaseIterator(dictIterator *iter); 156 dictEntry *dictGetRandomKey(dict *d); 157 void dictPrintStats(dict *d); 158 unsigned int dictGenHashFunction(const unsigned char *buf, int len); 159 unsigned int dictGenCaseHashFunction(const unsigned char *buf, int len); 160 void dictEmpty(dict *d); 161 void dictEnableResize(void); 162 void dictDisableResize(void); 163 int dictRehash(dict *d, int n); 164 int dictRehashMilliseconds(dict *d, int ms); 165 void dictSetHashFunctionSeed(unsigned int initval); 166 unsigned int dictGetHashFunctionSeed(void); 167 168 /* Hash table types */ 169 extern dictType dictTypeHeapStringCopyKey; 170 extern dictType dictTypeHeapStrings; 171 extern dictType dictTypeHeapStringCopyKeyValue; 172 173 #endif /* __DICT_H */ 174