38 lines
779 B
JavaScript
38 lines
779 B
JavaScript
'use strict';
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var RingBuffer = require('./ring_buffer');
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var Pledge = function() {
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this._complete = false;
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this._callbacks = new RingBuffer(Pledge.QUEUE_SIZE);
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};
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Pledge.QUEUE_SIZE = 4;
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Pledge.all = function(list) {
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var pledge = new Pledge(),
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pending = list.length,
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n = pending;
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if (pending === 0) pledge.done();
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while (n--) list[n].then(function() {
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pending -= 1;
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if (pending === 0) pledge.done();
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});
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return pledge;
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};
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Pledge.prototype.then = function(callback) {
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if (this._complete) callback();
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else this._callbacks.push(callback);
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};
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Pledge.prototype.done = function() {
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this._complete = true;
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var callbacks = this._callbacks, callback;
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while (callback = callbacks.shift()) callback();
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};
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module.exports = Pledge;
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