dreusel / ioredfour Goto Github PK

const Lock = require('ioredfour');

(async ()=> {
  const testLock = new Lock({
    // Can also be an `Object` of options to pass to `new Redis()`
    // https://www.npmjs.com/package/ioredis#connect-to-redis, or an existing
    // instance of `ioredis` (if you want to reuse one connection, though this
    // module must create a second).
    redis: 'redis://localhost:6379',
    namespace: 'mylock',
    // Don't consider the lock owned until writes have been replicated at least this many times
    minReplications: 1,
    // Wait at most this many miliseconds for replication
    replicationTimeout: 500,
  });
  const id = Math.random();

  // First, acquire the lock.
  const firstlock = await testLock.acquireLock(id, 60 * 1000 /* Lock expires after 60sec if not released */).catch(e => {
    console.log('error acquiring first lock', e);
  });
  if (!firstlock.success) {
    console.log('lock exists', firstlock);
  } else {
    console.log('lock acquired initially');
  }

  // Another server might be waiting for the lock like this.
  testLock.waitAcquireLock(id, 60 * 1000 /* Lock expires after 60sec */ , 10 * 1000 /* Wait for lock for up to 10sec */).then(secondlock => {
    if (secondlock.success) {
      console.log('second lock acquired after wait!', secondlock);
    } else {
      console.log('second lock not acquired after wait!', secondlock);
    }
  }).catch(e => {
    console.log('error wait acquiring', e);
  });

  // When the original lock is released, `waitAcquireLock` is fired on the other server.
  setTimeout(async () => {
    try {
      await testLock.releaseLock(firstlock);
      console.log('released lock');
    } catch(e) {
      console.log('error releasing', e);
    }
  }, 10 * 1000);
})();