Issue 4125 - [emscripten] Convert filter classes to C++

compiled/Filter.h

 #pragma once
 
 #include <vector>
 
 #include "String.h"
 #include "intrusive_ptr.h"
 #include "debug.h"
 
 class Filter : public ref_counted
 {
 protected:
   OwnedString mText;
 
 public:
-  explicit Filter(const String& text);
-  virtual ~Filter();
-
-  /* TODO
-  std::vector<Subscription> subscriptions;

[sergei, 2016/06/16 21:16:36]

May be it makes sense to remove this comment from here.

Just wonder, why do we need to have several subscriptions as a member of Filter
object? It seems it should be vice versa, subscription should have a set of
filters.

[Wladimir Palant, 2016/12/06 10:47:28]

This is merely a reverse mapping meant to speed up lookups. E.g. when a filter
is added it's important to know what subscriptions it belongs to and whether
these are enabled or disabled.

-  */
-
-  EMSCRIPTEN_KEEPALIVE const String& GetText() const
-  {
-    return mText;
-  }
-
   enum Type
   {
     UNKNOWN = 0,
     INVALID = 1,
     COMMENT = 2,
     BLOCKING = 3,
     WHITELIST = 4,
     ELEMHIDE = 5,
     ELEMHIDEEXCEPTION = 6,
     CSSPROPERTY = 7,
   };
 
-  virtual Type GetType() const = 0;

[sergei, 2016/06/16 21:16:34]

Can we set filter type in constructor and make this method non virtual? It
should reduce the amount of code and it should not actually add any overhead.

[Wladimir Palant, 2016/12/06 10:47:26]

Actually, if we do that then we can just read out the filter type member from
JavaScript - this will save some overhead. I implemented it this way now.

+  explicit Filter(Type type, const String& text);
+  ~Filter();
+
+  Type mType;
+
+  /* TODO
+  std::vector<Subscription> mSubscriptions;
+  */
+
+  EMSCRIPTEN_KEEPALIVE const String& GetText() const
+  {
+    return mText;
+  }
 
   EMSCRIPTEN_KEEPALIVE OwnedString Serialize() const;
 
-  static EMSCRIPTEN_KEEPALIVE Type GetType(Filter* filter)
-  {
-    return filter->GetType();
-  }
-
   static EMSCRIPTEN_KEEPALIVE Filter* FromText(DependentString& text);
-  static EMSCRIPTEN_KEEPALIVE Filter* GetKnownFilter(const String& text);
 };
 
 typedef intrusive_ptr<Filter> FilterPtr;