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