rlock

distributed lock for nodejs using redis

Usage no npm install needed!

<script type="module">
  import rlock from 'https://cdn.skypack.dev/rlock';
</script>

README

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)