Process-Locker

Base on redis, one resource only be processed once. Requests about the resource will be pending until process is complete and then the result will be returned. 基于redis，同一个资源仅会被处理一次，如果一个资源正在处理，当前请求都会被挂起，待处理完成后返回结果。

Usage:

var Locker = require('process-locker')
var locker = Locker()
var key = 'resource-key'
locker.request(key)(function (err, resp) {
  var result
	if (resp.status === Locker.LOCKED) {
    // do the process
    locker.publish(key, result)()
  } else if (resp.status === Locker.DONE) {
    result = resp.result
  }
  // process result
})

API:

Locker(options)

return a locker instance options:

• redis thunk-redis-client or string use thunk-redis client to lock and publish events. Default use: localhost:6379
• subRedis thunk-redis-client or string use thunk-redis client to subscribe events. Default use: localhost:6379
• redisPrefix String Default: locker
• channel String channel name for redis subscribe Default: channel
• resultTimeout Number milliseconds to cache the process result Default: 30 * 60 * 1000
• lockTimeout Number milliseconds to lock the process result Default: 60 * 60 * 1000

Locker.LOCKED

locker locked the key name and you have the only permission to process the resource. So you are the real processor.

Locker.DONE

locker received the real processor signal and notice all requests.

locker.request (key)

Request status for process named key. If status is Locker.status.LOCKED, means you become the real processor. Return a thunk function (use thunks) callback(err, resp)

• key String the name of the process.
• resp Object
  • status Locker.LOCKED or Locker.DONE
  • result Object the result published by the real processor

locker.publish (key, result, timeout)

return a thunk function (use thunks) callback(err)

• key String name of the process.
• result Object result used to notice all requests
• timeout Number milliseconds to cache the process result that will publish for other request