Issue 616 - Enforce $generichide and $genericblock in Chrome

background.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 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
@@ skipping 453 matching lines @@
 {
   switch (msg.type)
   {
     case "get-selectors":
       var selectors = [];
 
       if (!isFrameWhitelisted(sender.page, sender.frame, "DOCUMENT") &&
           !isFrameWhitelisted(sender.page, sender.frame, "ELEMHIDE"))
       {
         var noStyleRules = false;
+        var specificOnly = isFrameWhitelisted(sender.page, sender.frame, "GENERICHIDE");

[Sebastian Noack, 2015/03/12 12:36:12]

I'm concerned about the performance implications running yet another filter
match here. We already have serious issues with the performance of this code.

Currently we look for "DOCUMENT" exception rules, if there are none we look for
"ELEMHIDE" exception rules, and if there are still none we now also look for
"GENERICHIDE" exception rules.

So how about optimizing Matcher.matchesAny() to consider multiple types? The
algorithm could look roughly like this:

function matchesAny(types)
{
  result = null;
  priority = types.length - 1;

  for (filter of filters)
  {
    for (i = 0; i <= priority; i++)
    {
      if (filter.matches(types[i]))
      {
         result = filter;
         priority = i;
      }
    }

    if (priority == 0)
      break;
  }

  return filter;
}

[kzar, 2015/03/12 19:22:45]

That sound sensible to me but as you mentioned to me on IRC this would require a
new (blocking) issue to be filed and fixed to adapt matchesAny first.

What's your opinion here Wladimir?

         var host = extractHostFromFrame(sender.frame);
+
         for (var i = 0; i < noStyleRulesHosts.length; i++)
         {
           var noStyleHost = noStyleRulesHosts[i];
           if (host == noStyleHost || (host.length > noStyleHost.length &&
                                       host.substr(host.length - noStyleHost.length - 1) == "." + noStyleHost))
           {
             noStyleRules = true;
           }
         }
-        selectors = ElemHide.getSelectorsForDomain(host, false);
+        selectors = ElemHide.getSelectorsForDomain(host, specificOnly);
         if (noStyleRules)
         {
           selectors = selectors.filter(function(s)
           {
             return !/\[style[\^\$]?=/.test(s);
           });
         }
       }
 
       sendResponse(selectors);
@@ skipping 82 matching lines @@
   page.sendMessage({type: "clickhide-deactivate"});
   refreshIconAndContextMenu(page);
 });
 
 setTimeout(function()
 {
   var notificationToShow = NotificationStorage.getNextToShow();
   if (notificationToShow)
     showNotification(notificationToShow);
 }, 3 * 60 * 1000);