Avoid unnecessary dictionary lookups

refs #12555

lib/base/dictionary.cpp

@@ -228,3 +228,8 @@ bool Dictionary::HasOwnField(const String& field) const
 {
 	return Contains(field);
 }
+
+bool Dictionary::GetOwnField(const String& field, Value *result) const
+{
+	return Get(field, result);
+}

lib/base/dictionary.hpp

@@ -121,6 +121,7 @@ public:
 	virtual Value GetFieldByName(const String& field, bool sandboxed, const DebugInfo& debugInfo) const override;
 	virtual void SetFieldByName(const String& field, const Value& value, const DebugInfo& debugInfo) override;
 	virtual bool HasOwnField(const String& field) const override;
+	virtual bool GetOwnField(const String& field, Value *result) const override;
 
 private:
 	std::map<String, Value> m_Data; /**< The data for the dictionary. */

lib/base/object.cpp

@@ -109,6 +109,22 @@ bool Object::HasOwnField(const String& field) const
 	return type->GetFieldId(field) != -1;
 }
 
+bool Object::GetOwnField(const String& field, Value *result) const
+{
+	Type::Ptr type = GetReflectionType();
+
+	if (!type)
+		return false;
+
+	int tid = type->GetFieldId(field);
+
+	if (tid == -1)
+		return false;
+
+	*result = GetField(tid);
+	return true;
+}
+
 Value Object::GetFieldByName(const String& field, bool sandboxed, const DebugInfo& debugInfo) const
 {
 	Type::Ptr type = GetReflectionType();

lib/base/object.hpp

@@ -127,6 +127,7 @@ public:
 	virtual Value GetFieldByName(const String& field, bool sandboxed, const DebugInfo& debugInfo) const;
 	virtual void SetFieldByName(const String& field, const Value& value, const DebugInfo& debugInfo);
 	virtual bool HasOwnField(const String& field) const;
+	virtual bool GetOwnField(const String& field, Value *result) const;
 	virtual void ValidateField(int id, const Value& value, const ValidationUtils& utils);
 	virtual void NotifyField(int id, const Value& cookie = Empty);
 	virtual Object::Ptr NavigateField(int id) const;

lib/config/expression.cpp

@@ -121,8 +121,8 @@ ExpressionResult VariableExpression::DoEvaluate(ScriptFrame& frame, DebugHint *d
 
 	if (frame.Locals && frame.Locals->Get(m_Variable, &value))
 		return value;
-	else if (frame.Self.IsObject() && frame.Locals != static_cast<Object::Ptr>(frame.Self) && static_cast<Object::Ptr>(frame.Self)->HasOwnField(m_Variable))
+	else if (frame.Self.IsObject() && frame.Locals != frame.Self.Get<Object::Ptr>() && frame.Self.Get<Object::Ptr>()->GetOwnField(m_Variable, &value))
-		return VMOps::GetField(frame.Self, m_Variable, frame.Sandboxed, m_DebugInfo);
+		return value;
 	else if (VMOps::FindVarImport(frame, m_Variable, &value, m_DebugInfo))
 		return value;
 	else
@@ -138,7 +138,7 @@ bool VariableExpression::GetReference(ScriptFrame& frame, bool init_dict, Value
 
 		if (dhint)
 			*dhint = NULL;
-	} else if (frame.Self.IsObject() && frame.Locals != static_cast<Object::Ptr>(frame.Self) && static_cast<Object::Ptr>(frame.Self)->HasOwnField(m_Variable)) {
+	} else if (frame.Self.IsObject() && frame.Locals != frame.Self.Get<Object::Ptr>() && frame.Self.Get<Object::Ptr>()->HasOwnField(m_Variable)) {
 		*parent = frame.Self;
 
 		if (dhint && *dhint)