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

lib/filterClassesNew.js

Index: lib/filterClassesNew.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/lib/filterClassesNew.js
@@ -0,0 +1,75 @@
+"use strict";
+
+let compiled = require("./compiled");
+let {
+  createClass, wrapCall, stringArg, stringResult, defineProperty, defineMethod,
+  defineStringProperty,
+  _CreatePointer, _DeletePointer,
+  _Filter_GetType, _Filter_GetText, _Filter_FromText, _Filter_Normalize,
+  _InvalidFilter_GetReason,
+  _ActiveFilter_GetDisabled, _ActiveFilter_SetDisabled,
+  _ActiveFilter_GetHitCount, _ActiveFilter_SetHitCount,
+  _ActiveFilter_GetLastHit, _ActiveFilter_SetLastHit,
+  _RegExpFilter_Matches
+} = compiled;
+
+let constructors = Object.create(null);
+
+function createFilterClass(superclass, type, typeId)
+{
+  let result = createClass(superclass);
+  if (type)
+    Object.defineProperty(result.prototype, "type", {get: () => type, enumerable: true});
+  if (typeId)
+    constructors[typeId] = result;
+  return result;
+}
+
+function filterResult(call)
+{
+  return function()
+  {
+    let pointer = _CreatePointer();
+    try
+    {
+      let params = Array.slice(arguments);
+      params.unshift(pointer);
+
+      call.apply(this, params);
+      let type = _Filter_GetType(pointer);
+      if (type in constructors)
+        return new (constructors[type])(pointer);
+      else
+        throw new Error("Unexpected filter type " + type);
+    }
+    catch (e)
+    {
+      _DeletePointer(pointer);
+      throw e;
+    }
+  };
+}
+
+exports.Filter = createFilterClass();
+exports.Filter.fromText = wrapCall(stringArg(0, filterResult(_Filter_FromText)));
+exports.Filter.normalize = wrapCall(stringArg(0, stringResult(_Filter_Normalize)));
+defineStringProperty(exports.Filter, "text", _Filter_GetText);
+
+exports.InvalidFilter = createFilterClass(exports.Filter, "invalid", 1);
+defineStringProperty(exports.InvalidFilter, "reason", _InvalidFilter_GetReason);
+
+exports.CommentFilter = createFilterClass(exports.Filter, "comment", 2);
+
+exports.ActiveFilter = createFilterClass(exports.Filter);
+defineProperty(exports.ActiveFilter, "disabled", _ActiveFilter_GetDisabled, _ActiveFilter_SetDisabled);
+defineProperty(exports.ActiveFilter, "hitCount", _ActiveFilter_GetHitCount, _ActiveFilter_SetHitCount);
+defineProperty(exports.ActiveFilter, "lastHit", _ActiveFilter_GetLastHit, _ActiveFilter_SetLastHit);
+
+exports.RegExpFilter = createFilterClass(exports.ActiveFilter, "blocking", 3);
+defineMethod(exports.RegExpFilter, "matches", stringArg(1, _RegExpFilter_Matches));
+
+exports.WhiteListFilter = createFilterClass(exports.RegExpFilter, "whitelist", 4);
+exports.ElemHideBase = createFilterClass(exports.ActiveFilter);
+exports.ElemHideFilter = createFilterClass(exports.ElemHideBase, "elemhide", 5);
+exports.ElemHideException = createFilterClass(exports.ElemHideBase, "elemhideexception", 6);
+exports.CSSPropertyFilter = createFilterClass(exports.ElemHideBase, "cssproperty", 7);