dict是redis中的基本数据结构,源码中是通过hash表来实现的。项目将挑选几个主要函数和大家分享下redis源码的简洁。
先看dict的数据结构如下
typedef struct dictType {
unsigned int (*hashFunction)(const void *key);
void *(*keyDup)(void *privdata, const void *key);
void *(*valDup)(void *privdata, const void *obj);
int (*keyCompare)(void *privdata, const void *key1, const void *key2);
void (*keyDestructor)(void *privdata, void *key);
void (*valDestructor)(void *privdata, void *obj);
} dictType;
typedef struct dictht {
dictEntry **table;
unsigned long size;
unsigned long sizemask;
unsigned long used;
} dictht;
typedef struct dict {
dictType *type;
void *privdata;
dictht ht[2];
long rehashidx; /* rehashing not in progress if rehashidx == -1 */
unsigned long iterators; /* number of iterators currently running */
} dict;
type是hash表的内置函数,包括计算hash key,比较hash key等等。
ht[2]中的每个元素表示一张hash表。
原文:http://www.cnblogs.com/real-madrid/p/7822425.html