[大数据]Redis Lua 命令的原子性

LUA 脚本
–获取KEY
local key1 = KEYS[1] --users set
local key2 = KEYS[2] – lucky money count

local userNm = ARGV[1] – use name

–返回的变量
local result = {}

–redis command
local count = redis.call(“get”, key2)

–用一个临时变量来存放json,json是要放入要返回的数组中的
local jsonRedisTemp={}

if tonumber(count) > 0
then
local isExistFlg = redis.call(“sismember”,key1,userNm)
if (isExistFlg == 1)
then
jsonRedisTemp[“exist”] = true
jsonRedisTemp[“count”] = count
jsonRedisTemp[“userNm”] = userNm
jsonRedisTemp[“getResul”] = “Fail got before”
else
jsonRedisTemp[“exist”] = false
redis.call(“sadd”,key1,userNm)
redis.call(“decr”,key2)
jsonRedisTemp[“count”] = redis.call(“get”, key2)
jsonRedisTemp[“userNm”] = userNm
jsonRedisTemp[“getResul”] = “Success”
end

else
jsonRedisTemp[“count”] = 0
jsonRedisTemp[“userNm”] = userNm
jsonRedisTemp[“getResul”] = “Fail No count”
end

result[1] = cjson.encode(jsonRedisTemp)

return result