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) 2006-2012, 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 iterator, 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 long long fingerprint; /* unsafe iterator fingerprint for misuse detection */ 92 } dictIterator; 93 94 typedef void (dictScanFunction)(void *privdata, const dictEntry *de); 95 96 /* This is the initial size of every hash table */ 97 #define DICT_HT_INITIAL_SIZE 4 98 99 /* ------------------------------- Macros ------------------------------------*/ 100 #define dictFreeVal(d, entry) \ 101 if ((d)->type->valDestructor) \ 102 (d)->type->valDestructor((d)->privdata, (entry)->v.val) 103 104 #define dictSetVal(d, entry, _val_) do { \ 105 if ((d)->type->valDup) \ 106 entry->v.val = (d)->type->valDup((d)->privdata, _val_); \ 107 else \ 108 entry->v.val = (_val_); \ 109 } while(0) 110 111 #define dictSetSignedIntegerVal(entry, _val_) \ 112 do { entry->v.s64 = _val_; } while(0) 113 114 #define dictSetUnsignedIntegerVal(entry, _val_) \ 115 do { entry->v.u64 = _val_; } while(0) 116 117 #define dictFreeKey(d, entry) \ 118 if ((d)->type->keyDestructor) \ 119 (d)->type->keyDestructor((d)->privdata, (entry)->key) 120 121 #define dictSetKey(d, entry, _key_) do { \ 122 if ((d)->type->keyDup) \ 123 entry->key = (d)->type->keyDup((d)->privdata, _key_); \ 124 else \ 125 entry->key = (_key_); \ 126 } while(0) 127 128 #define dictCompareKeys(d, key1, key2) \ 129 (((d)->type->keyCompare) ? \ 130 (d)->type->keyCompare((d)->privdata, key1, key2) : \ 131 (key1) == (key2)) 132 133 #define dictHashKey(d, key) (d)->type->hashFunction(key) 134 #define dictGetKey(he) ((he)->key) 135 #define dictGetVal(he) ((he)->v.val) 136 #define dictGetSignedIntegerVal(he) ((he)->v.s64) 137 #define dictGetUnsignedIntegerVal(he) ((he)->v.u64) 138 #define dictSlots(d) ((d)->ht[0].size+(d)->ht[1].size) 139 #define dictSize(d) ((d)->ht[0].used+(d)->ht[1].used) 140 #define dictIsRehashing(ht) ((ht)->rehashidx != -1) 141 142 /* API */ 143 dict *dictCreate(dictType *type, void *privDataPtr); 144 int dictExpand(dict *d, unsigned long size); 145 int dictAdd(dict *d, void *key, void *val); 146 dictEntry *dictAddRaw(dict *d, void *key); 147 int dictReplace(dict *d, void *key, void *val); 148 dictEntry *dictReplaceRaw(dict *d, void *key); 149 int dictDelete(dict *d, const void *key); 150 int dictDeleteNoFree(dict *d, const void *key); 151 void dictRelease(dict *d); 152 dictEntry * dictFind(dict *d, const void *key); 153 void *dictFetchValue(dict *d, const void *key); 154 int dictResize(dict *d); 155 dictIterator *dictGetIterator(dict *d); 156 dictIterator *dictGetSafeIterator(dict *d); 157 dictEntry *dictNext(dictIterator *iter); 158 void dictReleaseIterator(dictIterator *iter); 159 dictEntry *dictGetRandomKey(dict *d); 160 int dictGetRandomKeys(dict *d, dictEntry **des, int count); 161 void dictPrintStats(dict *d); 162 unsigned int dictGenHashFunction(const void *key, int len); 163 unsigned int dictGenCaseHashFunction(const unsigned char *buf, int len); 164 void dictEmpty(dict *d, void(callback)(void*)); 165 void dictEnableResize(void); 166 void dictDisableResize(void); 167 int dictRehash(dict *d, int n); 168 int dictRehashMilliseconds(dict *d, int ms); 169 void dictSetHashFunctionSeed(unsigned int initval); 170 unsigned int dictGetHashFunctionSeed(void); 171 unsigned long dictScan(dict *d, unsigned long v, dictScanFunction *fn, void *privdata); 172 173 /* Hash table types */ 174 extern dictType dictTypeHeapStringCopyKey; 175 extern dictType dictTypeHeapStrings; 176 extern dictType dictTypeHeapStringCopyKeyValue; 177 178 #endif /* __DICT_H */ 179