Bones/node_modules/when/lib/env.js

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2017-05-17 13:45:25 -04:00
/** @license MIT License (c) copyright 2010-2014 original author or authors */
/** @author Brian Cavalier */
/** @author John Hann */
/*global process,document,setTimeout,clearTimeout,MutationObserver,WebKitMutationObserver*/
(function(define) { 'use strict';
define(function(require) {
/*jshint maxcomplexity:6*/
// Sniff "best" async scheduling option
// Prefer process.nextTick or MutationObserver, then check for
// setTimeout, and finally vertx, since its the only env that doesn't
// have setTimeout
var MutationObs;
var capturedSetTimeout = typeof setTimeout !== 'undefined' && setTimeout;
// Default env
var setTimer = function(f, ms) { return setTimeout(f, ms); };
var clearTimer = function(t) { return clearTimeout(t); };
var asap = function (f) { return capturedSetTimeout(f, 0); };
// Detect specific env
if (isNode()) { // Node
asap = function (f) { return process.nextTick(f); };
} else if (MutationObs = hasMutationObserver()) { // Modern browser
asap = initMutationObserver(MutationObs);
} else if (!capturedSetTimeout) { // vert.x
var vertxRequire = require;
var vertx = vertxRequire('vertx');
setTimer = function (f, ms) { return vertx.setTimer(ms, f); };
clearTimer = vertx.cancelTimer;
asap = vertx.runOnLoop || vertx.runOnContext;
}
return {
setTimer: setTimer,
clearTimer: clearTimer,
asap: asap
};
function isNode () {
return typeof process !== 'undefined' &&
Object.prototype.toString.call(process) === '[object process]';
}
function hasMutationObserver () {
return (typeof MutationObserver !== 'undefined' && MutationObserver) ||
(typeof WebKitMutationObserver !== 'undefined' && WebKitMutationObserver);
}
function initMutationObserver(MutationObserver) {
var scheduled;
var node = document.createTextNode('');
var o = new MutationObserver(run);
o.observe(node, { characterData: true });
function run() {
var f = scheduled;
scheduled = void 0;
f();
}
var i = 0;
return function (f) {
scheduled = f;
node.data = (i ^= 1);
};
}
});
}(typeof define === 'function' && define.amd ? define : function(factory) { module.exports = factory(require); }));