зеркало из https://github.com/mozilla/gecko-dev.git
55 строки
1.5 KiB
JavaScript
55 строки
1.5 KiB
JavaScript
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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"use strict";
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/**
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* From underscore's `_.throttle`
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* http://underscorejs.org
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* (c) 2009-2014 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
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* Underscore may be freely distributed under the MIT license.
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*
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* Returns a function, that, when invoked, will only be triggered at most once during a
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* given window of time. The throttled function will run as much as it can, without ever
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* going more than once per wait duration.
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*
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* @param {Function} func
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* The function to throttle
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* @param {number} wait
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* The wait period
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* @param {Object} scope
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* The scope to use for func
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* @return {Function} The throttled function
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*/
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function throttle(func, wait, scope) {
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let args, result;
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let timeout = null;
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let previous = 0;
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const later = function() {
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previous = Date.now();
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timeout = null;
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result = func.apply(scope, args);
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args = null;
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};
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return function() {
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const now = Date.now();
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const remaining = wait - (now - previous);
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args = arguments;
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if (remaining <= 0) {
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clearTimeout(timeout);
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timeout = null;
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previous = now;
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result = func.apply(scope, args);
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args = null;
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} else if (!timeout) {
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timeout = setTimeout(later, remaining);
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}
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return result;
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};
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}
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exports.throttle = throttle;
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