60 lines
1.8 KiB
JavaScript
60 lines
1.8 KiB
JavaScript
(function (root) {
|
|
'use strict';
|
|
|
|
function makeThrottleTimer(opts) {
|
|
const o = opts || {};
|
|
const now = typeof o.now === 'function' ? o.now : (() => Date.now());
|
|
const schedule = typeof o.schedule === 'function'
|
|
? o.schedule
|
|
: ((cb, ms) => setTimeout(cb, ms));
|
|
const clear = typeof o.clear === 'function' ? o.clear : ((h) => clearTimeout(h));
|
|
|
|
let handle = null;
|
|
let burstStart = null;
|
|
let pendingFn = null;
|
|
|
|
function fire() {
|
|
handle = null;
|
|
burstStart = null;
|
|
const fn = pendingFn;
|
|
pendingFn = null;
|
|
if (typeof fn === 'function') fn();
|
|
}
|
|
|
|
function request(fn, delay, maxWait) {
|
|
if (typeof fn === 'function') pendingFn = fn;
|
|
const t = now();
|
|
if (burstStart === null) burstStart = t;
|
|
let wait = typeof delay === 'number' && delay >= 0 ? delay : 0;
|
|
if (typeof maxWait === 'number' && maxWait >= 0) {
|
|
const remaining = maxWait - (t - burstStart);
|
|
wait = Math.min(wait, remaining < 0 ? 0 : remaining);
|
|
}
|
|
if (handle !== null) clear(handle);
|
|
handle = schedule(fire, wait);
|
|
}
|
|
|
|
function flushSync() {
|
|
if (handle !== null) { clear(handle); handle = null; }
|
|
burstStart = null;
|
|
const fn = pendingFn;
|
|
pendingFn = null;
|
|
if (typeof fn === 'function') fn();
|
|
}
|
|
|
|
function cancel() {
|
|
if (handle !== null) { clear(handle); handle = null; }
|
|
burstStart = null;
|
|
pendingFn = null;
|
|
}
|
|
|
|
function isPending() { return handle !== null; }
|
|
|
|
return { request, flushSync, cancel, isPending };
|
|
}
|
|
|
|
const api = { makeThrottleTimer };
|
|
if (typeof module !== 'undefined' && module.exports) module.exports = api;
|
|
else if (root) root.ThrottleTimer = api;
|
|
})(typeof window !== 'undefined' ? window : this);
|