3 var RingBuffer = require('./ring_buffer');
5 var Pledge = function() {
6 this._complete = false;
7 this._callbacks = new RingBuffer(Pledge.QUEUE_SIZE);
10 Pledge.QUEUE_SIZE = 4;
12 Pledge.all = function(list) {
13 var pledge = new Pledge(),
14 pending = list.length,
17 if (pending === 0) pledge.done();
19 while (n--) list[n].then(function() {
21 if (pending === 0) pledge.done();
26 Pledge.prototype.then = function(callback) {
27 if (this._complete) callback();
28 else this._callbacks.push(callback);
31 Pledge.prototype.done = function() {
32 this._complete = true;
33 var callbacks = this._callbacks, callback;
34 while (callback = callbacks.shift()) callback();
37 module.exports = Pledge;