MQTemplateProtocol.hpp

/***************************************************************************
  tag: Peter Soetens  Thu Oct 22 11:59:07 CEST 2009  MQTemplateProtocol.hpp

                        MQTemplateProtocol.hpp -  description
                           -------------------
    begin                : Thu October 22 2009
    copyright            : (C) 2009 Peter Soetens
    email                : peter@thesourcworks.com

 ***************************************************************************
 *   This library is free software; you can redistribute it and/or         *
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 *   version 2 of the License.                                             *
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 *   software library without restriction.  Specifically, if other files   *
 *   instantiate templates or use macros or inline functions from this     *
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#ifndef ORO_MQ_TEMPATE_PROTOCOL_HPP
#define ORO_MQ_TEMPATE_PROTOCOL_HPP

#include "MQLib.hpp"
#include "../../types/TypeMarshaller.hpp"
#include "MQChannelElement.hpp"

#include <boost/type_traits/has_virtual_destructor.hpp>
#include <boost/static_assert.hpp>

namespace RTT
{ namespace mqueue
  {
      template<class T>
      class MQTemplateProtocol
          : public RTT::types::TypeMarshaller
      {
      public:
          BOOST_STATIC_ASSERT( !boost::has_virtual_destructor<T>::value );
          typedef T UserType;

          virtual std::pair<void const*,int> fillBlob( base::DataSourceBase::shared_ptr source, void* blob, int size, void* cookie) const
          {
              if ( sizeof(T) <= (unsigned int)size)
                  return std::make_pair(source->getRawConstPointer(), int(sizeof(T)));
              return std::make_pair((void const*)0,int(0));
          }

          virtual bool updateFromBlob(const void* blob, int size, base::DataSourceBase::shared_ptr target, void* cookie) const
          {
            typename internal::AssignableDataSource<T>::shared_ptr ad = internal::AssignableDataSource<T>::narrow( target.get() );
            assert( size == sizeof(T) );
            if ( ad ) {
                ad->set( *(T*)(blob) );
                return true;
            }
            return false;
          }

          virtual unsigned int getSampleSize(base::DataSourceBase::shared_ptr ignored, void* cookie) const
          {
              // re-implement this in case of complex types, like std::vector<T>.
              return sizeof(T);
          }

          virtual base::ChannelElementBase::shared_ptr createStream(base::PortInterface* port, const ConnPolicy& policy, bool is_sender) const {
              try {
                  base::ChannelElementBase::shared_ptr mq = new MQChannelElement<T>(port, *this, policy, is_sender);
                  if ( !is_sender ) {
                      // the receiver needs a buffer to store his messages in.
                      base::ChannelElementBase::shared_ptr buf = detail::DataSourceTypeInfo<T>::getTypeInfo()->buildDataStorage(policy);
                      mq->setOutput(buf);
                  }
                  return mq;
              } catch(std::exception& e) {
                  log(Error) << "Failed to create MQueue Channel element: " << e.what() << endlog();
              }
              return base::ChannelElementBase::shared_ptr();
          }

      };
}
}

#endif