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asap.js
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asap.js
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export default function asap(callback, arg) {
var length = queue.push([callback, arg]);
if (length === 1) {
// If length 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();
}
}
var browserGlobal = (typeof window !== 'undefined') ? window : {};
var BrowserMutationObserver = browserGlobal.MutationObserver || browserGlobal.WebKitMutationObserver;
// node
function useNextTick() {
return function() {
process.nextTick(flush);
};
}
function useMutationObserver() {
var iterations = 0;
var observer = new BrowserMutationObserver(flush);
var node = document.createTextNode('');
observer.observe(node, { characterData: true });
return function() {
node.data = (iterations = ++iterations % 2);
};
}
function useSetTimeout() {
return function() {
setTimeout(flush, 1);
};
}
var queue = [];
function flush() {
for (var i = 0; i < queue.length; i++) {
var tuple = queue[i];
var callback = tuple[0], arg = tuple[1];
callback(arg);
}
queue.length = 0;
}
var scheduleFlush;
// Decide what async method to use to triggering processing of queued callbacks:
if (typeof process !== 'undefined' && {}.toString.call(process) === '[object process]') {
scheduleFlush = useNextTick();
} else if (BrowserMutationObserver) {
scheduleFlush = useMutationObserver();
} else {
scheduleFlush = useSetTimeout();
}