co-queue

A FIFO queue for co.

Example

Create a queue with one producer and two consumers doing fake work:

var Queue = require('co-queue');
var co = require('co');
var wait = require('co-wait');
 
var queue = new Queue;
 
co(function*(){
  while (true) {
    console.log('consumer 1: %s', yield queue.next());
    yield wait(Math.random() * 1000);
  }
});
 
co(function*(){
  while (true) {
    console.log('consumer 2: %s', yield queue.next());
    yield wait(Math.random() * 1000);
  }
});
 
setInterval(function(){
  queue.push(Math.random());
}, 300);

The output is:

$ make example
consumer 1: 0.4872316620312631
consumer 2: 0.8702194727957249
consumer 1: 0.200025983620435
consumer 2: 0.14811497158370912
consumer 2: 0.6677501150406897
consumer 1: 0.5147413061931729
consumer 2: 0.6373226766008884
consumer 1: 0.5006165818776935
consumer 2: 0.15247466461732984
consumer 2: 0.9118324755690992
^C

Installation

You need to run node 0.11.x or higher and add the --harmony flag.

$ npm install co-queue

API

Queue()

Create a new FIFO queue.

Queue#push(data)

Push data onto the queue.

Queue#push is bound to the queue, so hooking into existing libraries is easy:

emitter.on('data', queue.push);
stream.on('data', queue.push);
fn(queue.push);

Queue#next()

Get the next piece of data.

Queue#max(max)

Set the maximum buffer size. When reached, new data will be dropped.

Queue#events.on('overflow', fn)

The overflow event will be emitted whenever data is dropped, which will be passed to fn as first argument.

License

MIT