rlock

rlock

Distributed lock for nodejs using redis

Usage example

var rlock = require('rlock');
var lock = new rlock.Lock('rlock.key');
lock.acquire(function(err, done) {
	if (!done) {
		return console.log('Could not acquire lock');
	}
	// Do stuffs
	done();
	// OR
	done(function(err, ok){
		console.log(ok);
	});
	// OR
	lock.release(function(err, ok){
		console.log(ok);
	});
});
// Set global redis client, with your own setting
var rlock = require('rlock');
var redis = require('redis');
rlock.setRedisClient(redis.createClient(6378));

API

Lock(key, options)

• key String
• options Object, optional.

Available option:

• maxRetries Maximum number of retries if can not acquire the lock, specify 0 if no retry, default 10.
• retryDelay Number of milliseconds to wait until next try, default 50 milliseconds.
• timeout Number of milliseconds before the lock expires, default 5000 milliseconds.
• rclient Instance of redis client, see https://github.com/mranney/node_redis#rediscreateclientport-host-options. If not specified it will create a client with default config (or the global one if set). Be aware that redis.createClient crashes on error if not handle.

Lock.acquire(callback)

• callback Function(err, done) success if and only if done is a function. Can use it to release the lock.

Lock.release(callback)

• callback Function(err, ok) ok true if success. Callback is optional. This can only call if Lock.acquire was successful.

setRedisClient(client)

• client Instance of redis client, see https://github.com/mranney/node_redis#rediscreateclientport-host-options When no rclient specified in options this will be used.