带有EX和NX的Ruby REDIS(Ruby REDIS with EX AND NX)

 我试图在我们的rails应用程序服务器中实现锁定。 
 
 如果我想永远获得一个锁，REDIS.setnx工作正常。 但我希望获得有效期限的锁定，基本上我希望锁定在一定时间后过期，以便锁定可以再次获得。 
 
 从REDIS的设置文档中，我发现它是可能的。 https://redis.io/commands/set “命令SET resource-name anystring NX EX max-lock-time是一种使用Redis实现锁定系统的简单方法。” 
 
 如何在ruby中实现这一点。 命令： 
 
REDIS = Redis.new(host: ENV['REDIS_HOST'], port: ENV['REDIS_PORT'])
REDIS.set "key", "value", "nx", "ex", 3600
 
 抛出错误： 
 
ArgumentError: wrong number of arguments (given 5, expected 2..3)
 
 还有另一种方法，但需要两次REDIS调用。 
 
if(REDIS.setnx "key", "value")
    REDIS.setex "key", 3600, "value"
end
 
 该方法不是优选的。 我正在寻找一种方法来获得REDIS锁定与红宝石单一REDIS调用。 基本上“SET资源名称anystring NX EX max-lock-time”等效于ruby。 
 
 谢谢， 
 
 Anshul 

I am trying to implement a locking in our rails application server.
 
REDIS.setnx works fine if I want to acquire a lock forever. But I want to acquire lock with expiry, basically I want the lock to expire after certain duration so that lock will be free to be acquired again.
 
From REDIS's set documentation, I see it is possible. https://redis.io/commands/set "The command SET resource-name anystring NX EX max-lock-time is a simple way to implement a locking system with Redis."
 
How to implement this in ruby. Command :
 
REDIS = Redis.new(host: ENV['REDIS_HOST'], port: ENV['REDIS_PORT'])
REDIS.set "key", "value", "nx", "ex", 3600
 
throws error:
 
ArgumentError: wrong number of arguments (given 5, expected 2..3)
 
There is another way to do that, but it requires two REDIS calls.
 
if(REDIS.setnx "key", "value")
    REDIS.setex "key", 3600, "value"
end
 
This method is not preferred. I am looking to a way to acquire REDIS lock with single REDIS call in ruby. Basically "SET resource-name anystring NX EX max-lock-time" equivalent in ruby.
 
Thanks,
 
Anshul

原文：https://stackoverflow.com/questions/48318207