index.js
820 Bytes
module.exports = throttle;
/**
* Returns a new function that, when invoked, invokes `func` at most once per `wait` milliseconds.
*
* @param {Function} func Function to wrap.
* @param {Number} wait Number of milliseconds that must elapse between `func` invocations.
* @return {Function} A new function that wraps the `func` function passed in.
*/
function throttle (func, wait) {
var ctx, args, rtn, timeoutID; // caching
var last = 0;
return function throttled () {
ctx = this;
args = arguments;
var delta = new Date() - last;
if (!timeoutID)
if (delta >= wait) call();
else timeoutID = setTimeout(call, wait - delta);
return rtn;
};
function call () {
timeoutID = 0;
last = +new Date();
rtn = func.apply(ctx, args);
ctx = null;
args = null;
}
}