redis3.0.7源码阅读(十)redis数据库-蒲公英云

redis3.0.7源码阅读(十)redis数据库

版本：3.0.7

1.源文件

redis.h

db.c

2.数据结构

/*
 * 客户端
 */
typedef struct redisClient {
    ...
    // 当时连接使用的数据库
    redisDb *db;
    ...
} redisClient;
/*
 * 服务器
 */
struct redisServer {
    ...
    // db数组
    redisDb *db;
    // db数量
    int dbnum; /* Total number of configured DBs */
    ...
};
struct evictionPoolEntry {
    unsigned long long idle;    /* Object idle time. */
    sds key;                    /* Key name. */
};
/*
 * redis数据库
 */
/* Redis database representation. There are multiple databases identified
 * by integers from 0 (the default database) up to the max configured
 * database. The database number is the 'id' field in the structure. */
typedef struct redisDb {
    // 数据库键空间，保存着数据库中的所有键值对
    dict *dict;                 /* The keyspace for this DB */
    // 键的过期时间，字典的键为键，字典的值为过期的时间戳
    dict *expires;              /* Timeout of keys with a timeout set */
    // 正处于阻塞状态的键
    dict *blocking_keys;        /* Keys with clients waiting for data (BLPOP) */
    // 可以解除阻塞的键
    dict *ready_keys;           /* Blocked keys that received a PUSH */
    // 正在被 WATCH 命令监视的键
    dict *watched_keys;         /* WATCHED keys for MULTI/EXEC CAS */
    // LRU淘汰候选池
    struct evictionPoolEntry *eviction_pool;    /* Eviction pool of keys */
    // 数据库号码
    int id;                     /* Database ID */
    // 数据库的键的平均 TTL ，统计信息
    long long avg_ttl;          /* Average TTL, just for stats */
} redisDb;