fuse-box
Version:
Fuse-Box a bundler that does it right
253 lines (221 loc) • 8.5 kB
JavaScript
// Copyright (c) 2012 Barnesandnoble.com, llc, Donavon West, and Domenic Denicola
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
(function(global, undefined) {
'use strict';
if (global.setImmediate) {
return;
}
var nextHandle = 1; // Spec says greater than zero
var tasksByHandle = {};
var currentlyRunningATask = false;
var doc = global.document;
var registerImmediate;
function setImmediate(callback) {
// Callback can either be a function or a string
if (typeof callback !== 'function') {
callback = new Function('' + callback);
}
// Copy function arguments
var args = new Array(arguments.length - 1);
for (var i = 0; i < args.length; i++) {
args[i] = arguments[i + 1];
}
// Store and register the task
var task = { callback: callback, args: args };
tasksByHandle[nextHandle] = task;
registerImmediate(nextHandle);
return nextHandle++;
}
function clearImmediate(handle) {
delete tasksByHandle[handle];
}
function run(task) {
var callback = task.callback;
var args = task.args;
switch (args.length) {
case 0:
callback();
break;
case 1:
callback(args[0]);
break;
case 2:
callback(args[0], args[1]);
break;
case 3:
callback(args[0], args[1], args[2]);
break;
default:
callback.apply(undefined, args);
break;
}
}
function runIfPresent(handle) {
// From the spec: "Wait until any invocations of this algorithm started before this one have completed."
// So if we're currently running a task, we'll need to delay this invocation.
if (currentlyRunningATask) {
// Delay by doing a setTimeout. setImmediate was tried instead, but in Firefox 7 it generated a
// "too much recursion" error.
setTimeout(runIfPresent, 0, handle);
} else {
var task = tasksByHandle[handle];
if (task) {
currentlyRunningATask = true;
try {
run(task);
} finally {
clearImmediate(handle);
currentlyRunningATask = false;
}
}
}
}
function installNextTickImplementation() {
registerImmediate = function(handle) {
process.nextTick(function() {
runIfPresent(handle);
});
};
}
function canUsePostMessage() {
// The test against `importScripts` prevents this implementation from being installed inside a web worker,
// where `global.postMessage` means something completely different and can't be used for this purpose.
if (global.postMessage && !global.importScripts) {
var postMessageIsAsynchronous = true;
var oldOnMessage = global.onmessage;
global.onmessage = function() {
postMessageIsAsynchronous = false;
};
global.postMessage('', '*');
global.onmessage = oldOnMessage;
return postMessageIsAsynchronous;
}
}
function installPostMessageImplementation() {
// Installs an event handler on `global` for the `message` event: see
// * https://developer.mozilla.org/en/DOM/window.postMessage
// * http://www.whatwg.org/specs/web-apps/current-work/multipage/comms.html#crossDocumentMessages
var messagePrefix = 'setImmediate$' + Math.random() + '$';
var onGlobalMessage = function(event) {
if (event.source === global && typeof event.data === 'string' && event.data.indexOf(messagePrefix) === 0) {
runIfPresent(+event.data.slice(messagePrefix.length));
}
};
if (global.addEventListener) {
global.addEventListener('message', onGlobalMessage, false);
} else {
global.attachEvent('onmessage', onGlobalMessage);
}
registerImmediate = function(handle) {
global.postMessage(messagePrefix + handle, '*');
};
}
function installMessageChannelImplementation() {
var channel = new MessageChannel();
channel.port1.onmessage = function(event) {
var handle = event.data;
runIfPresent(handle);
};
registerImmediate = function(handle) {
channel.port2.postMessage(handle);
};
}
function installReadyStateChangeImplementation() {
var html = doc.documentElement;
registerImmediate = function(handle) {
// Create a <script> element; its readystatechange event will be fired asynchronously once it is inserted
// into the document. Do so, thus queuing up the task. Remember to clean up once it's been called.
var script = doc.createElement('script');
script.onreadystatechange = function() {
runIfPresent(handle);
script.onreadystatechange = null;
html.removeChild(script);
script = null;
};
html.appendChild(script);
};
}
function installSetTimeoutImplementation() {
registerImmediate = function(handle) {
setTimeout(runIfPresent, 0, handle);
};
}
// If supported, we should attach to the prototype of global, since that is where setTimeout et al. live.
var attachTo = Object.getPrototypeOf && Object.getPrototypeOf(global);
attachTo = attachTo && attachTo.setTimeout ? attachTo : global;
// Don't get fooled by e.g. browserify environments.
if ({}.toString.call(global.process) === '[object process]') {
// For Node.js before 0.9
installNextTickImplementation();
} else if (canUsePostMessage()) {
// For non-IE10 modern browsers
installPostMessageImplementation();
} else if (global.MessageChannel) {
// For web workers, where supported
installMessageChannelImplementation();
} else if (doc && 'onreadystatechange' in doc.createElement('script')) {
// For IE 6–8
installReadyStateChangeImplementation();
} else {
// For older browsers
installSetTimeoutImplementation();
}
attachTo.setImmediate = setImmediate;
attachTo.clearImmediate = clearImmediate;
})(typeof self === 'undefined' ? (typeof global === 'undefined' ? this : global) : self);
var apply = Function.prototype.apply;
// DOM APIs, for completeness
exports.setTimeout = function() {
return new Timeout(apply.call(setTimeout, window, arguments), clearTimeout);
};
exports.setInterval = function() {
return new Timeout(apply.call(setInterval, window, arguments), clearInterval);
};
exports.clearTimeout = exports.clearInterval = function(timeout) {
if (timeout) {
timeout.close();
}
};
function Timeout(id, clearFn) {
this._id = id;
this._clearFn = clearFn;
}
Timeout.prototype.unref = Timeout.prototype.ref = function() {};
Timeout.prototype.close = function() {
this._clearFn.call(window, this._id);
};
// Does not start the time, just sets up the members needed.
exports.enroll = function(item, msecs) {
clearTimeout(item._idleTimeoutId);
item._idleTimeout = msecs;
};
exports.unenroll = function(item) {
clearTimeout(item._idleTimeoutId);
item._idleTimeout = -1;
};
exports._unrefActive = exports.active = function(item) {
clearTimeout(item._idleTimeoutId);
var msecs = item._idleTimeout;
if (msecs >= 0) {
item._idleTimeoutId = setTimeout(function onTimeout() {
if (item._onTimeout) item._onTimeout();
}, msecs);
}
};
exports.setImmediate = setImmediate;
exports.clearImmediate = clearImmediate;