201 lines
8.0 KiB
JavaScript
Executable File
201 lines
8.0 KiB
JavaScript
Executable File
/**
|
||
Some credit for this helper goes to http://github.com/YuzuJS/setImmediate
|
||
*/
|
||
import { root } from './root';
|
||
export class ImmediateDefinition {
|
||
constructor(root) {
|
||
this.root = root;
|
||
if (root.setImmediate && typeof root.setImmediate === 'function') {
|
||
this.setImmediate = root.setImmediate.bind(root);
|
||
this.clearImmediate = root.clearImmediate.bind(root);
|
||
}
|
||
else {
|
||
this.nextHandle = 1;
|
||
this.tasksByHandle = {};
|
||
this.currentlyRunningATask = false;
|
||
// Don't get fooled by e.g. browserify environments.
|
||
if (this.canUseProcessNextTick()) {
|
||
// For Node.js before 0.9
|
||
this.setImmediate = this.createProcessNextTickSetImmediate();
|
||
}
|
||
else if (this.canUsePostMessage()) {
|
||
// For non-IE10 modern browsers
|
||
this.setImmediate = this.createPostMessageSetImmediate();
|
||
}
|
||
else if (this.canUseMessageChannel()) {
|
||
// For web workers, where supported
|
||
this.setImmediate = this.createMessageChannelSetImmediate();
|
||
}
|
||
else if (this.canUseReadyStateChange()) {
|
||
// For IE 6–8
|
||
this.setImmediate = this.createReadyStateChangeSetImmediate();
|
||
}
|
||
else {
|
||
// For older browsers
|
||
this.setImmediate = this.createSetTimeoutSetImmediate();
|
||
}
|
||
let ci = function clearImmediate(handle) {
|
||
delete clearImmediate.instance.tasksByHandle[handle];
|
||
};
|
||
ci.instance = this;
|
||
this.clearImmediate = ci;
|
||
}
|
||
}
|
||
identify(o) {
|
||
return this.root.Object.prototype.toString.call(o);
|
||
}
|
||
canUseProcessNextTick() {
|
||
return this.identify(this.root.process) === '[object process]';
|
||
}
|
||
canUseMessageChannel() {
|
||
return Boolean(this.root.MessageChannel);
|
||
}
|
||
canUseReadyStateChange() {
|
||
const document = this.root.document;
|
||
return Boolean(document && 'onreadystatechange' in document.createElement('script'));
|
||
}
|
||
canUsePostMessage() {
|
||
const root = this.root;
|
||
// The test against `importScripts` prevents this implementation from being installed inside a web worker,
|
||
// where `root.postMessage` means something completely different and can't be used for this purpose.
|
||
if (root.postMessage && !root.importScripts) {
|
||
let postMessageIsAsynchronous = true;
|
||
let oldOnMessage = root.onmessage;
|
||
root.onmessage = function () {
|
||
postMessageIsAsynchronous = false;
|
||
};
|
||
root.postMessage('', '*');
|
||
root.onmessage = oldOnMessage;
|
||
return postMessageIsAsynchronous;
|
||
}
|
||
return false;
|
||
}
|
||
// This function accepts the same arguments as setImmediate, but
|
||
// returns a function that requires no arguments.
|
||
partiallyApplied(handler, ...args) {
|
||
let fn = function result() {
|
||
const { handler, args } = result;
|
||
if (typeof handler === 'function') {
|
||
handler.apply(undefined, args);
|
||
}
|
||
else {
|
||
(new Function('' + handler))();
|
||
}
|
||
};
|
||
fn.handler = handler;
|
||
fn.args = args;
|
||
return fn;
|
||
}
|
||
addFromSetImmediateArguments(args) {
|
||
this.tasksByHandle[this.nextHandle] = this.partiallyApplied.apply(undefined, args);
|
||
return this.nextHandle++;
|
||
}
|
||
createProcessNextTickSetImmediate() {
|
||
let fn = function setImmediate() {
|
||
const { instance } = setImmediate;
|
||
let handle = instance.addFromSetImmediateArguments(arguments);
|
||
instance.root.process.nextTick(instance.partiallyApplied(instance.runIfPresent, handle));
|
||
return handle;
|
||
};
|
||
fn.instance = this;
|
||
return fn;
|
||
}
|
||
createPostMessageSetImmediate() {
|
||
// 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
|
||
const root = this.root;
|
||
let messagePrefix = 'setImmediate$' + root.Math.random() + '$';
|
||
let onGlobalMessage = function globalMessageHandler(event) {
|
||
const instance = globalMessageHandler.instance;
|
||
if (event.source === root &&
|
||
typeof event.data === 'string' &&
|
||
event.data.indexOf(messagePrefix) === 0) {
|
||
instance.runIfPresent(+event.data.slice(messagePrefix.length));
|
||
}
|
||
};
|
||
onGlobalMessage.instance = this;
|
||
root.addEventListener('message', onGlobalMessage, false);
|
||
let fn = function setImmediate() {
|
||
const { messagePrefix, instance } = setImmediate;
|
||
let handle = instance.addFromSetImmediateArguments(arguments);
|
||
instance.root.postMessage(messagePrefix + handle, '*');
|
||
return handle;
|
||
};
|
||
fn.instance = this;
|
||
fn.messagePrefix = messagePrefix;
|
||
return fn;
|
||
}
|
||
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 (this.currentlyRunningATask) {
|
||
// Delay by doing a setTimeout. setImmediate was tried instead, but in Firefox 7 it generated a
|
||
// 'too much recursion' error.
|
||
this.root.setTimeout(this.partiallyApplied(this.runIfPresent, handle), 0);
|
||
}
|
||
else {
|
||
let task = this.tasksByHandle[handle];
|
||
if (task) {
|
||
this.currentlyRunningATask = true;
|
||
try {
|
||
task();
|
||
}
|
||
finally {
|
||
this.clearImmediate(handle);
|
||
this.currentlyRunningATask = false;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
createMessageChannelSetImmediate() {
|
||
let channel = new this.root.MessageChannel();
|
||
channel.port1.onmessage = (event) => {
|
||
let handle = event.data;
|
||
this.runIfPresent(handle);
|
||
};
|
||
let fn = function setImmediate() {
|
||
const { channel, instance } = setImmediate;
|
||
let handle = instance.addFromSetImmediateArguments(arguments);
|
||
channel.port2.postMessage(handle);
|
||
return handle;
|
||
};
|
||
fn.channel = channel;
|
||
fn.instance = this;
|
||
return fn;
|
||
}
|
||
createReadyStateChangeSetImmediate() {
|
||
let fn = function setImmediate() {
|
||
const instance = setImmediate.instance;
|
||
const root = instance.root;
|
||
const doc = root.document;
|
||
const html = doc.documentElement;
|
||
let handle = instance.addFromSetImmediateArguments(arguments);
|
||
// 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.
|
||
let script = doc.createElement('script');
|
||
script.onreadystatechange = () => {
|
||
instance.runIfPresent(handle);
|
||
script.onreadystatechange = null;
|
||
html.removeChild(script);
|
||
script = null;
|
||
};
|
||
html.appendChild(script);
|
||
return handle;
|
||
};
|
||
fn.instance = this;
|
||
return fn;
|
||
}
|
||
createSetTimeoutSetImmediate() {
|
||
let fn = function setImmediate() {
|
||
const instance = setImmediate.instance;
|
||
let handle = instance.addFromSetImmediateArguments(arguments);
|
||
instance.root.setTimeout(instance.partiallyApplied(instance.runIfPresent, handle), 0);
|
||
return handle;
|
||
};
|
||
fn.instance = this;
|
||
return fn;
|
||
}
|
||
}
|
||
export const Immediate = new ImmediateDefinition(root);
|
||
//# sourceMappingURL=Immediate.js.map
|