Issue 616 - Enforce $generichide and $genericblock in Chrome

background.js

Index: background.js
diff --git a/background.js b/background.js
index 36158a2d5c129bcb5b81a9d375a72e7b24e2358f..2034beb32525e365a5bc09f6067288c093ead08d 100644
--- a/background.js
+++ b/background.js
@@ -471,7 +471,9 @@ ext.onMessage.addListener(function (msg, sender, sendResponse)
           !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];
@@ -481,7 +483,7 @@ ext.onMessage.addListener(function (msg, sender, sendResponse)
             noStyleRules = true;
           }
         }
-        selectors = ElemHide.getSelectorsForDomain(host, false);
+        selectors = ElemHide.getSelectorsForDomain(host, specificOnly);
         if (noStyleRules)
         {
           selectors = selectors.filter(function(s)