Issue 3222 - Expose filter type as a string property

lib/requestNotifier.js

Index: lib/requestNotifier.js
===================================================================
--- a/lib/requestNotifier.js
+++ b/lib/requestNotifier.js
@@ -15,17 +15,16 @@
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 /**
  * @fileOverview Stores Adblock Plus data to be attached to a window.
  */
 
 let {Utils} = require("utils");
-let {BlockingFilter, WhitelistFilter, ElemHideBase, ElemHideFilter, ElemHideException} = require("filterClasses");
 
 let nodeData = new WeakMap();
 let windowStats = new WeakMap();
 let windowSelection = new WeakMap();
 let requestNotifierMaxId = 0;
 let requestEntryMaxId = 0;
 
 /**
@@ -209,25 +208,26 @@ RequestNotifier.addNodeData = function(/
       hidden: 0,
       blocked: 0,
       whitelisted: 0,
       filters: {}
     });
   }
 
   let stats = windowStats.get(topWnd.document);
-  if (!filter || !(filter instanceof ElemHideBase))
+  let filterType = (filter ? filter.type : null);
+  if (filterType != "elemhide" && filterType != "elemhideexception" && filterType != "cssproperty")

[Thomas Greiner, 2015/11/03 11:32:40]

Just a suggestion: What about introducing an `isException` boolean property in
addition to the `type` property you introduced. That'd allow us to have a common
type for ElemHideFilter and ElemHideException that we can check for - similar to
how we currently check for ElemHideBase.

That'd allow us to keep checking filter inheritance at least to some extent
without introducing too much overhead.

[Wladimir Palant, 2015/11/03 12:23:24]

I think that would complicate things more than it would help. Right now there is
a 1:1 mapping between types and type strings, that's very straightforward. If
the type structure gets any more complicated we might want to think about type
identifiers like "elemhide:exception" and "elemhide:cssproperty" but I don't
think we are at a point where this would make sense.

     stats.items++;
   if (filter)
   {
-    if (filter instanceof BlockingFilter)
+    if (filterType == "blocking")
       stats.blocked++;
-    else if (filter instanceof WhitelistFilter || filter instanceof ElemHideException)
+    else if (filterType == "whitelist" || filterType == "elemhideexception")
       stats.whitelisted++;
-    else if (filter instanceof ElemHideFilter)
+    else if (filterType == "elemhide" || filterType == "cssproperty")
       stats.hidden++;
 
     if (filter.text in stats.filters)
       stats.filters[filter.text]++;
     else
       stats.filters[filter.text] = 1;
   }