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- /** Used to detect hot functions by number of calls within a span of milliseconds. */
- var HOT_COUNT = 800,
- HOT_SPAN = 16;
- /* Built-in method references for those with the same name as other `lodash` methods. */
- var nativeNow = Date.now;
- /**
- * Creates a function that'll short out and invoke `identity` instead
- * of `func` when it's called `HOT_COUNT` or more times in `HOT_SPAN`
- * milliseconds.
- *
- * @private
- * @param {Function} func The function to restrict.
- * @returns {Function} Returns the new shortable function.
- */
- function shortOut(func) {
- var count = 0,
- lastCalled = 0;
- return function() {
- var stamp = nativeNow(),
- remaining = HOT_SPAN - (stamp - lastCalled);
- lastCalled = stamp;
- if (remaining > 0) {
- if (++count >= HOT_COUNT) {
- return arguments[0];
- }
- } else {
- count = 0;
- }
- return func.apply(undefined, arguments);
- };
- }
- module.exports = shortOut;
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