nlf/mutis

mutexes for node.js, backed by redis

mutis

mutexes for node.js, powered by redis

usage

pass an already instantiated redis client to the constructor, you can then use the .lock() and .unlock() methods:

'use strict';

const Redis = require('redis');
const Mutis = require('mutis');

const client = Redis.createClient();
const mutex = new Mutis(client);

mutex.lock('the_key_you_want_to_lock').then((unlock) => {
  // 'unlock' here is a convenience method to unlock the mutex you just used
  
  doSomething().then(() => {
    // alternatively you can use mutex.unlock('the_key_you_want_to_lock')
    return unlock();
  });
});

mutis will wait for the lock to be available before returning, by the time your .then() is called your lock is acquired.

you can pass a second argument to .lock() to be used as a timeout, for example:

mutex.lock('my_key').then((unlock) => {
  // wait 1 second before unlocking
  setTimeout(() => {
    return unlock();
  }, 1000);

  mutex.lock('my_key', 500).then(() => {
    // this will never be reached since a timeout will occur
  }).catch((err) => {
    console.log(err instanceof Mutis.TimeoutError); // this will be true
  });
});

for additional usage examples, see the tests