/*命令映射表，参数1：命令，参数2：指向实现此命令的函数，参数3：参数个数，参数4：标志位（具体信息看注释），
 *参数5：从参数4计算而得到的字节掩码，参数6：作为可选项的获取键值的函数，参数7：第一个索引位置，参数8：最后一个索引位置
 *参数9：增量，参数10：命令执行时间，参数11：命令调用次数
 */
struct redisCommand redisCommandTable[] = {
    //获取字符串命令
    {"get",getCommand,2,"rF",0,NULL,1,1,1,0,0},
    //设置字符串命令
    {"set",setCommand,-3,"wm",0,NULL,1,1,1,0,0},
    //当且仅当key不存在的情况设置字符串
    {"setnx",setnxCommand,3,"wmF",0,NULL,1,1,1,0,0},
    //当且仅当key存在的情况设置字符串，生存时间为秒级
    {"setex",setexCommand,4,"wm",0,NULL,1,1,1,0,0},
    //设置字符串，生存时间为毫秒级
    {"psetex",psetexCommand,4,"wm",0,NULL,1,1,1,0,0},
    //如果key存在则在末尾加如果不存在就相当于set
    {"append",appendCommand,3,"wm",0,NULL,1,1,1,0,0},
    //字符串长度
    {"strlen",strlenCommand,2,"rF",0,NULL,1,1,1,0,0},
    //删除一个或多个key
    {"del",delCommand,-2,"w",0,NULL,1,-1,1,0,0},
    //判断key是否存在
    {"exists",existsCommand,2,"rF",0,NULL,1,1,1,0,0},
    //当key存在时清除偏移量后面的值，否则自动生成新字符串
    {"setbit",setbitCommand,4,"wm",0,NULL,1,1,1,0,0},
    //获取指定偏移量后的位
    {"getbit",getbitCommand,3,"rF",0,NULL,1,1,1,0,0},
    {"setrange",setrangeCommand,4,"wm",0,NULL,1,1,1,0,0},
    {"getrange",getrangeCommand,4,"r",0,NULL,1,1,1,0,0},
    {"substr",getrangeCommand,4,"r",0,NULL,1,1,1,0,0},
    {"incr",incrCommand,2,"wmF",0,NULL,1,1,1,0,0},
    {"decr",decrCommand,2,"wmF",0,NULL,1,1,1,0,0},
    {"mget",mgetCommand,-2,"r",0,NULL,1,-1,1,0,0},
    {"rpush",rpushCommand,-3,"wmF",0,NULL,1,1,1,0,0},
    {"lpush",lpushCommand,-3,"wmF",0,NULL,1,1,1,0,0},
    {"rpushx",rpushxCommand,3,"wmF",0,NULL,1,1,1,0,0},
    {"lpushx",lpushxCommand,3,"wmF",0,NULL,1,1,1,0,0},
    {"linsert",linsertCommand,5,"wm",0,NULL,1,1,1,0,0},
    {"rpop",rpopCommand,2,"wF",0,NULL,1,1,1,0,0},
    {"lpop",lpopCommand,2,"wF",0,NULL,1,1,1,0,0},
    {"brpop",brpopCommand,-3,"ws",0,NULL,1,1,1,0,0},
    {"brpoplpush",brpoplpushCommand,4,"wms",0,NULL,1,2,1,0,0},
    {"blpop",blpopCommand,-3,"ws",0,NULL,1,-2,1,0,0},
    {"llen",llenCommand,2,"rF",0,NULL,1,1,1,0,0},
    {"lindex",lindexCommand,3,"r",0,NULL,1,1,1,0,0},
    {"lset",lsetCommand,4,"wm",0,NULL,1,1,1,0,0},
    {"lrange",lrangeCommand,4,"r",0,NULL,1,1,1,0,0},
    {"ltrim",ltrimCommand,4,"w",0,NULL,1,1,1,0,0},
    {"lrem",lremCommand,4,"w",0,NULL,1,1,1,0,0},
    {"rpoplpush",rpoplpushCommand,3,"wm",0,NULL,1,2,1,0,0},
    {"sadd",saddCommand,-3,"wmF",0,NULL,1,1,1,0,0},
    {"srem",sremCommand,-3,"wF",0,NULL,1,1,1,0,0},
    {"smove",smoveCommand,4,"wF",0,NULL,1,2,1,0,0},
    {"sismember",sismemberCommand,3,"rF",0,NULL,1,1,1,0,0},
    {"scard",scardCommand,2,"rF",0,NULL,1,1,1,0,0},
    {"spop",spopCommand,2,"wRsF",0,NULL,1,1,1,0,0},
    {"srandmember",srandmemberCommand,-2,"rR",0,NULL,1,1,1,0,0},
    {"sinter",sinterCommand,-2,"rS",0,NULL,1,-1,1,0,0},
    {"sinterstore",sinterstoreCommand,-3,"wm",0,NULL,1,-1,1,0,0},
    {"sunion",sunionCommand,-2,"rS",0,NULL,1,-1,1,0,0},
    {"sunionstore",sunionstoreCommand,-3,"wm",0,NULL,1,-1,1,0,0},
    {"sdiff",sdiffCommand,-2,"rS",0,NULL,1,-1,1,0,0},
    {"sdiffstore",sdiffstoreCommand,-3,"wm",0,NULL,1,-1,1,0,0},
    {"smembers",sinterCommand,2,"rS",0,NULL,1,1,1,0,0},
    {"sscan",sscanCommand,-3,"rR",0,NULL,1,1,1,0,0},
    {"zadd",zaddCommand,-4,"wmF",0,NULL,1,1,1,0