| #ifndef QPID_FRAMING_INVOKER_H |
| #define QPID_FRAMING_INVOKER_H |
| |
| /* |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| */ |
| #include "qpid/framing/AMQMethodBody.h" |
| #include "qpid/framing/MethodBodyDefaultVisitor.h" |
| #include "qpid/framing/StructHelper.h" |
| |
| #include <boost/optional.hpp> |
| |
| namespace qpid { |
| namespace framing { |
| |
| class AMQMethodBody; |
| |
| /** |
| * Base class for invoker visitors. |
| */ |
| class Invoker: public MethodBodyDefaultVisitor, protected StructHelper |
| { |
| public: |
| struct Result { |
| public: |
| Result() : handled(false) {} |
| const std::string& getResult() const { return result; } |
| bool hasResult() const { return !result.empty(); } |
| bool wasHandled() const { return handled; } |
| operator bool() const { return handled; } |
| |
| std::string result; |
| bool handled; |
| }; |
| |
| void defaultVisit(const AMQMethodBody&) {} |
| Result getResult() const { return result; } |
| |
| protected: |
| Result result; |
| }; |
| |
| /** |
| * Invoke an invocable object. |
| * Invocable classes must provide a nested type Invoker. |
| */ |
| template <class Invocable> |
| Invoker::Result invoke(Invocable& target, const AMQMethodBody& body) { |
| typename Invocable::Invoker invoker(target); |
| body.accept(invoker); |
| return invoker.getResult(); |
| } |
| |
| /** |
| * Invoke an invocable object. |
| * Invocable classes must provide a nested type Invoker. |
| */ |
| template <class Invocable> |
| Invoker::Result invoke(Invocable& target, const AMQBody& body) { |
| typename Invocable::Invoker invoker(target); |
| const AMQMethodBody* method = body.getMethod(); |
| if (method) |
| method->accept(invoker); |
| return invoker.getResult(); |
| } |
| |
| }} // namespace qpid::framing |
| |
| #endif /*!QPID_FRAMING_INVOKER_H*/ |