The idea was taken from the official setnx doc.
Ruby redis setnx.
Ok if the value is set to key or null if the value does not set.
Redis in ruby chapter 4 adding the missing options to the set command.
Setex key name timeout value available since.
A ruby client that tries to match redis api one to one while still providing an idiomatic interface.
Setex set with expire.
Setnx set if not exists.
You may have to run redis server on another terminal to start the server before you can connect to it.
Supports both blocking and non blocking semantics.
See rubydoc info for the api docs of the latest published gem.
O 1 set key to hold the string value and set key to timeout after a given number of seconds.
Now you re ready to start using redis.
Psetex set with milliseconds expire.
There are a few gems available.
In the following example only one thread process server can enter the locked block at one time.
Set mykey value expire mykey seconds.
Gem install redis you can connect to redis by instantiating the redis class.
This command is equivalent to executing the following commands.
Return value type.
Redis setnx 命令 redis 字符串 string redis setnx set if not exists 命令在指定的 key 不存在时 为 key 设置指定的值 语法 redis setnx 命令基本语法如下 redis 127 0 0 1 6379 setnx key name value 可用版本 1 0 0 返回值 设置成功 返回 1 设置失败.
If it is not it will sleep for some time and retry from the start.
Set is one of the most used redis commands and has many variants.
You can interact with redis directly using redis cli but if you want to work with redis from ruby you should use a gem.
C4 sends get lock foo to check if the lock expired.
C4 sends setnx lock foo in order to acquire the lock.
There is demand for additional variants such as setexnx becuase it is a pretty common pattern in caching and sessions handling to set an object only if not already inside the cache and setting it with an expire.
