Make sure to indicate to Chrome when our filters change

webrequest.js

 /*
  * This file is part of the Adblock Plus extension,
  * Copyright (C) 2006-2012 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 chrome.webRequest.onBeforeRequest.addListener(onBeforeRequest, {urls: ["http://*/*", "https://*/*"]}, ["blocking"]);
 chrome.webRequest.onHeadersReceived.addListener(onHeadersReceived, {urls: ["http://*/*", "https://*/*"]}, ["responseHeaders"]);
 chrome.tabs.onRemoved.addListener(forgetTab);
 
+var onFilterChangeTimeout = null;
+function onFilterChange()
+{
+  onFilterChangeTimeout = null;
+  chrome.webRequest.handlerBehaviorChanged();
+}
+
 var importantNotifications = {
   'filter.added': true,
   'filter.removed': true,
   'filter.disabled': true,
   'subscription.added': true,
   'subscription.removed': true,
   'subscription.disabled': true,
   'subscription.updated': true,
   'load': true
 };
+
 require("filterNotifier").FilterNotifier.addListener(function(action)
 {
   if (action in importantNotifications)
-    chrome.webRequest.handlerBehaviorChanged();

[Thomas Greiner, 2012/10/29 16:40:16]

according to the docs we shouldn't call it too often
adding multiple filters could make that happen so calling it through a timer
might improve that

example:
- 0:01 filter.added: starts 2s timer
- 0:02 filter.added: clears previous timer, starts 2s timer
- 0:04 timer fires and calls handlerBehaviorChanged()

it might not make sense, though, if there is no way in the application that such
notifications are being dispatched that quickly

+  {
+    // Execute delayed to prevent multiple executions in a quick succession
+    if (onFilterChangeTimeout != null)
+      window.clearTimeout(onFilterChangeTimeout);
+    onFilterChangeTimeout = window.setTimeout(onFilterChange, 2000);
+  }
 });
 
 var frames = {};
 
 function onBeforeRequest(details)
 {
   if (details.tabId == -1)
     return {};
 
   var type = details.type;
@@ skipping 140 matching lines @@
   {
     var parentUrl = getFrameUrl(tabId, parent);
     if (parentUrl && isWhitelisted(parentUrl, type))
       return true;
     if (parentUrl && "keyException" in frames[tabId][frameId])
       return true;
     parent = getFrameParent(tabId, parent);
   }
   return false;
 }