GoScrobble/web/node_modules/rsvp/lib/rsvp/asap.js

107 lines
2.9 KiB
JavaScript

let len = 0;
let vertxNext;
export default function asap(callback, arg) {
queue[len] = callback;
queue[len + 1] = arg;
len += 2;
if (len === 2) {
// If len is 1, that means that we need to schedule an async flush.
// If additional callbacks are queued before the queue is flushed, they
// will be processed by this flush that we are scheduling.
scheduleFlush();
}
}
const browserWindow = (typeof window !== 'undefined') ? window : undefined;
const browserGlobal = browserWindow || {};
const BrowserMutationObserver = browserGlobal.MutationObserver || browserGlobal.WebKitMutationObserver;
const isNode = typeof self === 'undefined' &&
typeof process !== 'undefined' && {}.toString.call(process) === '[object process]';
// test for web worker but not in IE10
const isWorker = typeof Uint8ClampedArray !== 'undefined' &&
typeof importScripts !== 'undefined' &&
typeof MessageChannel !== 'undefined';
// node
function useNextTick() {
let nextTick = process.nextTick;
// node version 0.10.x displays a deprecation warning when nextTick is used recursively
// setImmediate should be used instead instead
let version = process.versions.node.match(/^(?:(\d+)\.)?(?:(\d+)\.)?(\*|\d+)$/);
if (Array.isArray(version) && version[1] === '0' && version[2] === '10') {
nextTick = setImmediate;
}
return () => nextTick(flush);
}
// vertx
function useVertxTimer() {
if (typeof vertxNext !== 'undefined') {
return function() {
vertxNext(flush);
};
}
return useSetTimeout();
}
function useMutationObserver() {
let iterations = 0;
let observer = new BrowserMutationObserver(flush);
let node = document.createTextNode('');
observer.observe(node, { characterData: true });
return () => node.data = (iterations = ++iterations % 2);
}
// web worker
function useMessageChannel() {
let channel = new MessageChannel();
channel.port1.onmessage = flush;
return () => channel.port2.postMessage(0);
}
function useSetTimeout() {
return () => setTimeout(flush, 1);
}
const queue = new Array(1000);
function flush() {
for (let i = 0; i < len; i+=2) {
let callback = queue[i];
let arg = queue[i+1];
callback(arg);
queue[i] = undefined;
queue[i+1] = undefined;
}
len = 0;
}
function attemptVertex() {
try {
const vertx = Function('return this')().require('vertx');
vertxNext = vertx.runOnLoop || vertx.runOnContext;
return useVertxTimer();
} catch(e) {
return useSetTimeout();
}
}
let scheduleFlush;
// Decide what async method to use to triggering processing of queued callbacks:
if (isNode) {
scheduleFlush = useNextTick();
} else if (BrowserMutationObserver) {
scheduleFlush = useMutationObserver();
} else if (isWorker) {
scheduleFlush = useMessageChannel();
} else if (browserWindow === undefined && typeof require === 'function') {
scheduleFlush = attemptVertex();
} else {
scheduleFlush = useSetTimeout();
}