async-priorityQueue-example.js

// create a queue object with concurrency 1
var q = async.priorityQueue(function(task, callback) {
  console.log('Hello ' + task.name);
  callback();
}, 1);

// assign a callback
q.drain = function() {
  console.log('All items have been processed');
};

// add some items to the queue with priority
q.push({name: 'foo'}, 3, function(err) {
  console.log('Finished processing foo');
});

q.push({name: 'bar'}, 2, function (err) {
  console.log('Finished processing bar');
});

// add some items to the queue (batch-wise) which will have same priority
q.push([{name: 'baz'},{name: 'bay'},{name: 'bax'}], 1, function(err) {
  console.log('Finished processing item');
});