InputPort.hpp

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

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

 ***************************************************************************
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#ifndef ORO_INPUT_PORT_HPP
#define ORO_INPUT_PORT_HPP

#include "base/InputPortInterface.hpp"
#include "internal/Channels.hpp"
#include "internal/InputPortSource.hpp"
#include "Service.hpp"
#include "OperationCaller.hpp"

#include "OutputPort.hpp"

namespace RTT
{
    template<typename T>
    class InputPort : public base::InputPortInterface
    {
        friend class internal::ConnOutputEndpoint<T>;

        virtual bool connectionAdded( base::ChannelElementBase::shared_ptr channel_input, ConnPolicy const& policy ) { return true; }

        bool do_read(typename base::ChannelElement<T>::reference_t sample, FlowStatus& result, bool copy_old_data, const internal::ConnectionManager::ChannelDescriptor& descriptor)
        {
            typename base::ChannelElement<T>::shared_ptr input = static_cast< base::ChannelElement<T>* >( descriptor.get<1>().get() );
            assert( result != NewData );
            if ( input ) {
                FlowStatus tresult = input->read(sample, copy_old_data);
                // the result trickery is for not overwriting OldData with NoData.
                if (tresult == NewData) {
                    result = tresult;
                    return true;
                }
                // stores OldData result
                if (tresult > result)
                    result = tresult;
            }
            return false;
        }

        InputPort(InputPort const& orig);
        InputPort& operator=(InputPort const& orig);
    public:
        InputPort(std::string const& name = "unnamed", ConnPolicy const& default_policy = ConnPolicy())
            : base::InputPortInterface(name, default_policy)
        {}

        virtual ~InputPort() { disconnect(); }

        FlowStatus read(base::DataSourceBase::shared_ptr source)
        { return read(source, true); }

        FlowStatus read(base::DataSourceBase::shared_ptr source, bool copy_old_data)
        {
            typename internal::AssignableDataSource<T>::shared_ptr ds =
                boost::dynamic_pointer_cast< internal::AssignableDataSource<T> >(source);
            if (! ds)
            {
                log(Error) << "trying to read to an incompatible data source" << endlog();
                return NoData;
            }
            return read(ds->set(), copy_old_data);
        }

        FlowStatus readNewest(base::DataSourceBase::shared_ptr source, bool copy_old_data = true)
        {
            typename internal::AssignableDataSource<T>::shared_ptr ds =
                boost::dynamic_pointer_cast< internal::AssignableDataSource<T> >(source);
            if (! ds)
            {
                log(Error) << "trying to read to an incompatible data source" << endlog();
                return NoData;
            }
            return readNewest(ds->set(), copy_old_data);
        }

        FlowStatus read(typename base::ChannelElement<T>::reference_t sample)
        { return read(sample, true); }

        FlowStatus read(typename base::ChannelElement<T>::reference_t sample, bool copy_old_data)
        {
            FlowStatus result = NoData;
            // read and iterate if necessary.
            cmanager.select_reader_channel( boost::bind( &InputPort::do_read, this, boost::ref(sample), boost::ref(result), _1, _2 ), copy_old_data );
            return result;
        }


        FlowStatus readNewest(typename base::ChannelElement<T>::reference_t sample, bool copy_old_data = true)
        {
            FlowStatus result = read(sample, copy_old_data);
            if (result != RTT::NewData)
                return result;

            while (read(sample, false) == RTT::NewData);
            return RTT::NewData;
        }

        void getDataSample(T& sample)
        {
            typename base::ChannelElement<T>::shared_ptr input = static_cast< base::ChannelElement<T>* >( cmanager.getCurrentChannel() );
            if ( input ) {
                sample = input->data_sample();
            }
        }

        virtual const types::TypeInfo* getTypeInfo() const
        { return internal::DataSourceTypeInfo<T>::getTypeInfo(); }

        virtual base::PortInterface* clone() const
        { return new InputPort<T>(this->getName()); }

        virtual base::PortInterface* antiClone() const
        { return new OutputPort<T>(this->getName()); }

        base::DataSourceBase* getDataSource()
        {
            return new internal::InputPortSource<T>(*this);
        }

        virtual bool createStream(ConnPolicy const& policy)
        {
            return internal::ConnFactory::createStream(*this, policy);
        }

#ifndef ORO_DISABLE_PORT_DATA_SCRIPTING

        virtual Service* createPortObject()
        {
            Service* object = base::InputPortInterface::createPortObject();
            // Force resolution on the overloaded write method
            typedef FlowStatus (InputPort<T>::*ReadSample)(typename base::ChannelElement<T>::reference_t);
            ReadSample read_m = &InputPort<T>::read;
            object->addSynchronousOperation("read", read_m, this).doc("Reads a sample from the port.").arg("sample", "");
            object->addSynchronousOperation("clear", &InputPortInterface::clear, this).doc("Clears any remaining data in this port. After a clear, a read() will return NoData if no writes happened in between.");
            return object;
        }
#endif
    };
}

#endif