Defers setTimeout calls if no user input has been received for 15 seconds. Useful for stopping background tabs from continuing to use CPU cycles.
// ==UserScript==
// @name Background tab setTimeout muffler
// @namespace BSP
// @description Defers setTimeout calls if no user input has been received for 15 seconds. Useful for stopping background tabs from continuing to use CPU cycles.
// @include http://*
// @include https://*
// @exclude http://*.google.tld/*
// @exclude https://*.google.tld/*
// @exclude http://irc.lc/*
// @exclude https://irc.lc/*
// @exclude http://www.newsblur.com/*
// @exclude https://www.newsblur.com/*
// @exclude http://steamcommunity.com/id*
// @exclude https://www.duolingo.com/*
// @version 1
// @run-at document-start
// ==/UserScript==
var setInterval_old = unsafeWindow.setInterval;
var setTimeout_old = unsafeWindow.setTimeout;
var clearInterval_old = unsafeWindow.clearInterval;
var clearTimeout_old = unsafeWindow.clearTimeout;
var startDate = new Date;
//QueuedTimer format: {ID: [startTime, repeat, func, delay, args]}
var queuedTimers = null;
//ActiveTimer format: {ID: [repeat, func, delay, args, browserTimerID]}
var activeTimers = {};
var nextID = 1000000;
var lastUserInteraction = Date.now();
function debugLog() {
false && console && console.log && console.log(Array.slice(arguments, 0));
}
function muffleTimers() {
return (Date.now() - lastUserInteraction) > 15000;
}
function addTimer(ID, repeat, func, delay, args, isNew) {
if(typeof func != "function" && typeof func != "string") {
debugLog("addTimer", "invalid func", arguments);
throw Error("setInterval/setTimeout: invalid func");
}
delay = +(delay || 0); //coerce to number
if(isNaN(delay)) { //check for NaN (results from non-number strings/objects, etc.)
debugLog("addTimer", "invalid delay", arguments);
throw Error("setInterval/setTimeout: invalid delay");
}
//if(Object.keys(queuedTimers || {}).length + Object.keys(activeTimers).length > 500 && new Date - startDate > 15000) {
// debugLog("addTimer", "More than 100 timers!? Fuck that!", arguments);
// throw Error("STFU PLZ");
//}
if(muffleTimers()) {
if(!queuedTimers) queuedTimers = {};
isNew && debugLog("addTimer", "Deferred", [ID, repeat, delay, func]);
queuedTimers[ID] = [Date.now(), repeat, func, delay, args];
} else {
var browserTimerID = setTimeout_old(execTimer, delay, ID, repeat, func, delay, args);
isNew && debugLog("addTimer", "Scheduled", [ID, repeat, delay, func]);
activeTimers[ID] = [repeat, func, delay, args, browserTimerID];
}
return ID;
}
function execTimer(ID, repeat, func, delay, args) {
delete activeTimers[ID];
debugLog("execTimer", "Executing", ID, repeat);
//Re-add to the list so it can be cleared while in progress
if(repeat) {
addTimer(ID, repeat, func, delay, args, false);
}
try {
if(typeof func == "string") {
(function() { unsafeWindow.eval(func); }).apply(unsafeWindow);
} else {
func.apply(unsafeWindow, args);
}
} catch(ex) { /* Silence it like JS normally does */ debugLog("execTimer", "Error", arguments, ex); }
}
function onUserInteraction(event) {
lastUserInteraction = Date.now();
//If any timers are queued, restart them
if(queuedTimers) {
debugLog("onUserInteraction", "Processing deferred timers", arguments, queuedTimers);
try {
for(var ID in queuedTimers) {
//QueuedTimer format: {ID: [startTime, repeat, func, delay, args]}
var timer = queuedTimers[ID];
var delay = Math.max(0, timer[0] + timer[3] - Date.now());
var browserTimerID = setTimeout_old(execTimer, delay, ID, timer[1], timer[2], timer[3], timer[4]);
//ActiveTimer format: {ID: [repeat, func, delay, args, browserTimerID]}
activeTimers[ID] = [timer[1], timer[2], timer[3], timer[4], browserTimerID];
delete queuedTimers[ID];
}
} catch(ex) {
debugLog("onUserInteraction", "Error", ex);
}
queuedTimers = null;
}
removeEventListener("mousemove", onUserInteraction);
removeEventListener("keydown", onUserInteraction);
setTimeout_old(function() {
addEventListener("mousemove", onUserInteraction);
addEventListener("keydown", onUserInteraction);
}, 5000);
}
addEventListener("mousemove", onUserInteraction);
addEventListener("keydown", onUserInteraction);
unsafeWindow.setInterval = function setInterval() {
var func = arguments[0];
var delay = arguments[1];
var args = Array.slice(arguments, 2);
return addTimer(nextID++, true, func, delay, args, true);
};
unsafeWindow.setTimeout = function setTimeout() {
var func = arguments[0];
var delay = arguments[1];
var args = Array.slice(arguments, 2);
return addTimer(nextID++, false, func, delay, args, true);
};
function clearTimer(ID) {
if(queuedTimers && typeof(queuedTimers[ID]) != "undefined") {
debugLog("clearTimer", "Clearing deferred timer", arguments);
delete queuedTimers[ID];
}
if(typeof(activeTimers[ID]) != "undefined") {
debugLog("clearTimer", "Clearing active timer", arguments);
clearTimeout(activeTimers[ID][4]);
delete activeTimers[ID];
}
};
unsafeWindow.clearTimeout = clearTimer;
unsafeWindow.clearInterval = clearTimer;