ConnOutputEndPoint.hpp

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/***************************************************************************
  tag: Peter Soetens  Thu Oct 22 11:59:08 CEST 2009  ConnOutputEndPoint.hpp

                        ConnOutputEndPoint.hpp -  description
                           -------------------
    begin                : Thu October 22 2009
    copyright            : (C) 2009 Sylvain Joyeux
    email                : sylvain.joyeux@m4x.org

 ***************************************************************************
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 *   version 2 of the License.                                             *
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 *   instantiate templates or use macros or inline functions from this     *
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 *   resulting executable to be covered by the GNU General Public          *
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#ifndef ORO_CONN_OUTPUT_ENDPOINT_HPP
#define ORO_CONN_OUTPUT_ENDPOINT_HPP

#include "Channels.hpp"
#include "ConnID.hpp"

namespace RTT
{ namespace internal {

    template<typename T>
    class ConnOutputEndpoint : public base::MultipleInputsChannelElement<T>
    {
    private:
        InputPort<T>* port;

    public:
        typedef base::MultipleInputsChannelElement<T> Base;
        typedef boost::intrusive_ptr<ConnOutputEndpoint<T> > shared_ptr;

        ConnOutputEndpoint(InputPort<T>* port)
            : port(port)
        {
        }

        ~ConnOutputEndpoint()
        {
        }

        bool channelReady(base::ChannelElementBase::shared_ptr const& channel, ConnPolicy const& policy, ConnID *conn_id)
        {
            // cid is deleted/owned by the ConnectionManager.
            if ( channel ) {
                if (!conn_id) conn_id = new internal::SimpleConnID();
                if ( channel->inputReady(this) ) {
                    port->addConnection(conn_id, channel, policy);
                    return true;
                }
            }

            return false;
        }

        virtual WriteStatus write(typename Base::param_t sample)
        {
            WriteStatus result = Base::write(sample);
            if (result == WriteSuccess) {
                if (!signal()) {
                    return WriteFailure;
                }
            } else if (result == NotConnected) {
                // A ConnOutputEndPoint is always connected: If Base::write(sample) returned NotConnected the port
                // does not have a shared input buffer and you cannot write into this ChannelElement, but it still
                // should be considered as connected.
                // @sa OutputPort::connectionAdded()
                result = WriteFailure;
            }
            return result;
        }

        using Base::disconnect;

        virtual bool disconnect(const base::ChannelElementBase::shared_ptr& channel, bool forward = true)
        {
            InputPort<T>* port = this->port;
            if (port && channel && forward)
            {
                port->getManager()->removeConnection(channel.get(), /* disconnect = */ false);
            }

            // Call the base class: it does the common cleanup
            if (!Base::disconnect(channel, forward)) {
                return false;
            }

            // If this was the last connection, remove the buffer, too.
            // For forward == true this was already done by the base class.
            if (!this->connected() && !forward) {
                this->disconnect(true);
            }

            return true;
        }

        virtual bool signal()
        {
            InputPort<T>* port = this->port;
#ifdef ORO_SIGNALLING_PORTS
            if (port && port->new_data_on_port_event)
                (*port->new_data_on_port_event)(port);
#else
            if (port )
                port->signal();
#endif
            return true;
        }

        virtual base::PortInterface* getPort() const {
            return this->port;
        }

        virtual base::ChannelElementBase::shared_ptr getOutputEndPoint()
        {
            return this;
        }

        virtual typename base::ChannelElement<T>::shared_ptr getSharedBuffer()
        {
            return this->getOutput();
        }

        typename base::ChannelElement<T>::shared_ptr getReadEndpoint()
        {
            typename base::ChannelElement<T>::shared_ptr buffer = getSharedBuffer();
            if (buffer) {
                return buffer;
            } else {
                return this;
            }
        }
        
        std::string getElementName() const {
            return std::string("ConnOutputEndpoint");
        }
        
    };

}}

#endif