Issue 5143 - Convert ElemHideEmulation to C++

compiled/ElemHideEmulation.h

Index: compiled/ElemHideEmulation.h
===================================================================
new file mode 100644
--- /dev/null
+++ b/compiled/ElemHideEmulation.h
@@ -0,0 +1,62 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-present 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <vector>
+
+#include "bindings/runtime.h"
+#include "intrusive_ptr.h"
+#include "filter/ElemHideBase.h"
+
+class _ElemHideEmulation_FilterList : public ref_counted

[sergei, 2017/11/16 09:58:07]

IMO it's not a good idea to have names starting with underscore in C++. Could
you please rename it?

[hub, 2017/11/20 19:16:01]

That was part of the "spec" but indeed it conflict with C++.

+{
+  std::vector<ElemHideBasePtr> mFilters;
+public:
+  size_t BINDINGS_EXPORTED GetFilterCount() const
+  {
+    return mFilters.size();
+  }
+  ElemHideBase* BINDINGS_EXPORTED FilterAt(size_t idx)
+  {
+    return mFilters[idx].get();
+  }
+
+  void push_back(ElemHideBasePtr filter)

[sergei, 2017/11/16 09:58:07]

What about using r-value or l-value reference here?

[hub, 2017/11/20 19:16:01]

r-value is impossible: we don't want to move the value. (also fails to compile).
const l-value is fine.

[sergei, 2018/01/25 16:04:00]

Acknowledged. Perhaps we should revisit such methods later and create both
versions.

[hub, 2018/01/25 19:05:26]

Looking at the use case, move doesn't make sense here. We sure can revisit it if
the need arises.

+  {
+    mFilters.push_back(filter);
+  }
+
+};
+
+class ElemHideEmulation : public ref_counted
+{
+  StringMap<ElemHideBasePtr> mFilters;
+
+  static ElemHideEmulation* mInstance;
+
+public:
+  static ElemHideEmulation* BINDINGS_EXPORTED GetInstance()

[sergei, 2017/11/16 09:58:07]

IMO the growth of usage of the singleton pattern is getting really dangerous.
Can we stop doing it?

[hub, 2017/11/20 19:16:00]

yes.

+  {
+    return mInstance;
+  }
+
+  void BINDINGS_EXPORTED Add(ElemHideBase&);
+  void BINDINGS_EXPORTED Remove(ElemHideBase&);
+  void BINDINGS_EXPORTED Clear();
+  _ElemHideEmulation_FilterList* BINDINGS_EXPORTED GetRulesForDomain(DependentString&);
+};