| 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 | |
| 166 | /* Hash table types */ |
| 167 | extern dictType dictTypeHeapStringCopyKey; |
| 168 | extern dictType dictTypeHeapStrings; |
| 169 | extern dictType dictTypeHeapStringCopyKeyValue; |
| 170 | |
| 171 | #endif /* __DICT_H */ |