☰

Background tab setTimeout muffler

Defers setTimeout calls if no user input has been received for 15 seconds. Useful for stopping background tabs from continuing to use CPU cycles.

  1. // ==UserScript==
  2. // @name        Background tab setTimeout muffler
  3. // @namespace   BSP
  4. // @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.
  5. // @include     http://*
  6. // @include     https://*
  7. // @exclude	    http://*.google.tld/*
  8. // @exclude	    https://*.google.tld/*
  9. // @exclude	    http://irc.lc/*
  10. // @exclude	    https://irc.lc/*
  11. // @exclude	    http://www.newsblur.com/*
  12. // @exclude	    https://www.newsblur.com/*
  13. // @exclude		http://steamcommunity.com/id*
  14. // @exclude		https://www.duolingo.com/*
  15. // @version     1
  16. // @run-at document-start
  17. // ==/UserScript==
  18.  
  19. var setInterval_old = unsafeWindow.setInterval;
  20. var setTimeout_old = unsafeWindow.setTimeout;
  21. var clearInterval_old = unsafeWindow.clearInterval;
  22. var clearTimeout_old = unsafeWindow.clearTimeout;
  23. var startDate = new Date;
  24.  
  25. //QueuedTimer format: {ID: [startTime, repeat, func, delay, args]}
  26. var queuedTimers = null;
  27. //ActiveTimer format: {ID: [repeat, func, delay, args, browserTimerID]}
  28. var activeTimers = {};
  29. var nextID = 1000000;
  30. var lastUserInteraction = Date.now();
  31.  
  32. function debugLog() {
  33. 	false && console && console.log && console.log(Array.slice(arguments, 0));
  34. }
  35.  
  36. function muffleTimers() {
  37. 	return (Date.now() - lastUserInteraction) > 15000;
  38. }
  39.  
  40. function addTimer(ID, repeat, func, delay, args, isNew) {
  41. 	if(typeof func != "function" && typeof func != "string") {
  42. 		debugLog("addTimer", "invalid func", arguments);
  43. 		throw Error("setInterval/setTimeout: invalid func");
  44. 	}
  45. 	delay = +(delay || 0); //coerce to number
  46. 	if(isNaN(delay)) { //check for NaN (results from non-number strings/objects, etc.)
  47. 		debugLog("addTimer", "invalid delay", arguments);
  48. 		throw Error("setInterval/setTimeout: invalid delay");
  49. 	}
  50. 	
  51. 	//if(Object.keys(queuedTimers || {}).length + Object.keys(activeTimers).length > 500 && new Date - startDate > 15000) {
  52. 	//	debugLog("addTimer", "More than 100 timers!? Fuck that!", arguments);
  53. 	//	throw Error("STFU PLZ");
  54. 	//}
  55. 	
  56. 	if(muffleTimers()) {
  57. 		if(!queuedTimers) queuedTimers = {};
  58. 		isNew && debugLog("addTimer", "Deferred", [ID, repeat, delay, func]);
  59. 		queuedTimers[ID] = [Date.now(), repeat, func, delay, args];
  60. 	} else {
  61. 		var browserTimerID = setTimeout_old(execTimer, delay, ID, repeat, func, delay, args);
  62. 		isNew && debugLog("addTimer", "Scheduled", [ID, repeat, delay, func]);
  63. 		activeTimers[ID] = [repeat, func, delay, args, browserTimerID];
  64.  
  65. 	}
  66. 	return ID;
  67. }
  68.  
  69. function execTimer(ID, repeat, func, delay, args) {
  70. 	delete activeTimers[ID];
  71. 	debugLog("execTimer", "Executing", ID, repeat);
  72. 	
  73. 	//Re-add to the list so it can be cleared while in progress
  74. 	if(repeat) {
  75. 		addTimer(ID, repeat, func, delay, args, false);
  76. 	}
  77. 	
  78. 	try {
  79. 		if(typeof func == "string") {
  80. 			(function() { unsafeWindow.eval(func); }).apply(unsafeWindow);
  81. 		} else {
  82. 			func.apply(unsafeWindow, args);
  83. 		}
  84. 	} catch(ex) { /* Silence it like JS normally does */ debugLog("execTimer", "Error", arguments, ex); }
  85. 	
  86. }
  87.  
  88. function onUserInteraction(event) {
  89. 	lastUserInteraction = Date.now();
  90. 	//If any timers are queued, restart them
  91. 	if(queuedTimers) {
  92. 		debugLog("onUserInteraction", "Processing deferred timers", arguments, queuedTimers);
  93. 		try {
  94. 			for(var ID in queuedTimers) {
  95. 				//QueuedTimer format: {ID: [startTime, repeat, func, delay, args]}
  96. 				var timer = queuedTimers[ID];
  97. 				var delay = Math.max(0, timer[0] + timer[3] - Date.now());
  98.  
  99. 				var browserTimerID = setTimeout_old(execTimer, delay, ID, timer[1], timer[2], timer[3], timer[4]);
  100. 				//ActiveTimer format: {ID: [repeat, func, delay, args, browserTimerID]}
  101. 				activeTimers[ID] = [timer[1], timer[2], timer[3], timer[4], browserTimerID];
  102. 				delete queuedTimers[ID];
  103. 			}
  104. 		} catch(ex) {
  105. 			debugLog("onUserInteraction", "Error", ex);
  106. 		}
  107. 		queuedTimers = null;
  108. 	}
  109. 	removeEventListener("mousemove", onUserInteraction);
  110. 	removeEventListener("keydown", onUserInteraction);
  111. 	
  112. 	setTimeout_old(function() {
  113. 		addEventListener("mousemove", onUserInteraction);
  114. 		addEventListener("keydown", onUserInteraction);
  115. 	}, 5000);
  116. }
  117.  
  118. addEventListener("mousemove", onUserInteraction);
  119. addEventListener("keydown", onUserInteraction);
  120.  
  121.  
  122. unsafeWindow.setInterval = function setInterval() {
  123. 	var func = arguments[0];
  124. 	var delay = arguments[1];
  125. 	var args = Array.slice(arguments, 2);
  126. 	return addTimer(nextID++, true, func, delay, args, true);
  127. };
  128.  
  129.  
  130. unsafeWindow.setTimeout = function setTimeout() {
  131. 	var func = arguments[0];
  132. 	var delay = arguments[1];
  133. 	var args = Array.slice(arguments, 2);
  134. 	return addTimer(nextID++, false, func, delay, args, true);
  135. };
  136.  
  137. function clearTimer(ID) {
  138. 	if(queuedTimers && typeof(queuedTimers[ID]) != "undefined") {
  139. 		debugLog("clearTimer", "Clearing deferred timer", arguments);
  140. 		delete queuedTimers[ID];
  141. 	}
  142. 	if(typeof(activeTimers[ID]) != "undefined") {
  143. 		debugLog("clearTimer", "Clearing active timer", arguments);
  144. 		clearTimeout(activeTimers[ID][4]);
  145. 		delete activeTimers[ID];
  146. 	}
  147. };
  148.  
  149. unsafeWindow.clearTimeout = clearTimer;
  150. unsafeWindow.clearInterval = clearTimer;