Orocos Real-Time Toolkit  2.6.0
OutputPort.hpp
00001 /***************************************************************************
00002   tag: Peter Soetens  Thu Oct 22 11:59:08 CEST 2009  OutputPort.hpp
00003 
00004                         OutputPort.hpp -  description
00005                            -------------------
00006     begin                : Thu October 22 2009
00007     copyright            : (C) 2009 Sylvain Joyeux
00008     email                : sylvain.joyeux@m4x.org
00009 
00010  ***************************************************************************
00011  *   This library is free software; you can redistribute it and/or         *
00012  *   modify it under the terms of the GNU General Public                   *
00013  *   License as published by the Free Software Foundation;                 *
00014  *   version 2 of the License.                                             *
00015  *                                                                         *
00016  *   As a special exception, you may use this file as part of a free       *
00017  *   software library without restriction.  Specifically, if other files   *
00018  *   instantiate templates or use macros or inline functions from this     *
00019  *   file, or you compile this file and link it with other files to        *
00020  *   produce an executable, this file does not by itself cause the         *
00021  *   resulting executable to be covered by the GNU General Public          *
00022  *   License.  This exception does not however invalidate any other        *
00023  *   reasons why the executable file might be covered by the GNU General   *
00024  *   Public License.                                                       *
00025  *                                                                         *
00026  *   This library is distributed in the hope that it will be useful,       *
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00029  *   Lesser General Public License for more details.                       *
00030  *                                                                         *
00031  *   You should have received a copy of the GNU General Public             *
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00033  *   Foundation, Inc., 59 Temple Place,                                    *
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00035  *                                                                         *
00036  ***************************************************************************/
00037 
00038 
00039 #ifndef ORO_OUTPUT_PORT_HPP
00040 #define ORO_OUTPUT_PORT_HPP
00041 
00042 #include "base/OutputPortInterface.hpp"
00043 #include "base/DataObject.hpp"
00044 #include "internal/DataObjectDataSource.hpp"
00045 #include "internal/Channels.hpp"
00046 #include "internal/ConnFactory.hpp"
00047 #include "Service.hpp"
00048 #include "OperationCaller.hpp"
00049 
00050 #include "InputPort.hpp"
00051 
00052 namespace RTT
00053 {
00069     template<typename T>
00070     class OutputPort : public base::OutputPortInterface
00071     {
00072         friend class internal::ConnInputEndpoint<T>;
00073 
00074         bool do_write(typename base::ChannelElement<T>::param_t sample, const internal::ConnectionManager::ChannelDescriptor& descriptor)
00075         {
00076             typename base::ChannelElement<T>::shared_ptr output
00077                 = boost::static_pointer_cast< base::ChannelElement<T> >(descriptor.get<1>());
00078             if (output->write(sample))
00079                 return false;
00080             else
00081             {
00082                 log(Error) << "A channel of port " << getName() << " has been invalidated during write(), it will be removed" << endlog();
00083                 return true;
00084             }
00085         }
00086 
00087         bool do_init(typename base::ChannelElement<T>::param_t sample, const internal::ConnectionManager::ChannelDescriptor& descriptor)
00088         {
00089             typename base::ChannelElement<T>::shared_ptr output
00090                 = boost::static_pointer_cast< base::ChannelElement<T> >(descriptor.get<1>());
00091             if (output->data_sample(sample))
00092                 return false;
00093             else
00094             {
00095                 log(Error) << "A channel of port " << getName() << " has been invalidated during setDataSample(), it will be removed" << endlog();
00096                 return true;
00097             }
00098         }
00099 
00100         virtual bool connectionAdded( base::ChannelElementBase::shared_ptr channel_input, ConnPolicy const& policy ) {
00101             // Initialize the new channel with last written data if requested
00102             // (and available)
00103 
00104             // This this the input channel element of the whole connection
00105             typename base::ChannelElement<T>::shared_ptr channel_el_input =
00106                 static_cast< base::ChannelElement<T>* >(channel_input.get());
00107 
00108             if (has_initial_sample)
00109             {
00110                 T const& initial_sample = sample->Get();
00111                 if ( channel_el_input->data_sample(initial_sample) ) {
00112                     if ( has_last_written_value && policy.init )
00113                         return channel_el_input->write(initial_sample);
00114                     return true;
00115                 } else {
00116                     Logger::In in("OutputPort");
00117                     log(Error) << "Failed to pass data sample to data channel. Aborting connection."<<endlog();
00118                     return false;
00119                 }
00120             }
00121             // even if we're not written, test the connection with a default sample.
00122             return channel_el_input->data_sample( T() );
00123         }
00124 
00126         bool has_last_written_value;
00128         // data_sample or by calling write() with keeps_next_written_value or
00129         // keeps_last_written_value to true
00130         bool has_initial_sample;
00132         // This is used to initialize connections with a known sample
00133         bool keeps_next_written_value;
00135         // This is used to allow the use of the 'init' connection policy option
00136         bool keeps_last_written_value;
00137         typename base::DataObjectInterface<T>::shared_ptr sample;
00138 
00145         OutputPort( OutputPort const& orig );
00146         OutputPort& operator=(OutputPort const& orig);
00147 
00148     public:
00165         OutputPort(std::string const& name = "unnamed", bool keep_last_written_value = true)
00166             : base::OutputPortInterface(name)
00167             , has_last_written_value(false)
00168             , has_initial_sample(false)
00169             , keeps_next_written_value(false)
00170             , keeps_last_written_value(false)
00171             , sample( new base::DataObject<T>() )
00172         {
00173             if (keep_last_written_value)
00174                 keepLastWrittenValue(true);
00175         }
00176 
00177         void keepNextWrittenValue(bool keep)
00178         {
00179             keeps_next_written_value = keep;
00180         }
00181 
00182         void keepLastWrittenValue(bool keep)
00183         {
00184             keeps_last_written_value = keep;
00185         }
00186 
00187         bool keepsLastWrittenValue() const { return keeps_last_written_value; }
00188 
00194         T getLastWrittenValue() const
00195         {
00196             return sample->Get();
00197         }
00198 
00205         bool getLastWrittenValue(T& sample) const
00206         {
00207             if (has_last_written_value)
00208             {
00209                 this->sample->Get(sample);
00210                 return true;
00211             }
00212             return false;
00213         }
00214 
00215         virtual base::DataSourceBase::shared_ptr getDataSource() const
00216         {
00217             // we create this on the fly.
00218             return new internal::DataObjectDataSource<T>( sample );
00219         }
00220 
00230         void setDataSample(const T& sample)
00231         {
00232             this->sample->Set(sample);
00233             has_initial_sample = true;
00234             has_last_written_value = false;
00235 
00236             cmanager.delete_if( boost::bind(
00237                         &OutputPort<T>::do_init, this, boost::ref(sample), _1)
00238                     );
00239         }
00240 
00245         void write(const T& sample)
00246         {
00247             if (keeps_last_written_value || keeps_next_written_value)
00248             {
00249                 keeps_next_written_value = false;
00250                 has_initial_sample = true;
00251                 this->sample->Set(sample);
00252             }
00253             has_last_written_value = keeps_last_written_value;
00254 
00255             cmanager.delete_if( boost::bind(
00256                         &OutputPort<T>::do_write, this, boost::ref(sample), boost::lambda::_1)
00257                     );
00258         }
00259 
00260         void write(base::DataSourceBase::shared_ptr source)
00261         {
00262             typename internal::AssignableDataSource<T>::shared_ptr ds =
00263                 boost::dynamic_pointer_cast< internal::AssignableDataSource<T> >(source);
00264             if (ds)
00265                 write(ds->rvalue());
00266             else
00267             {
00268                 typename internal::DataSource<T>::shared_ptr ds =
00269                     boost::dynamic_pointer_cast< internal::DataSource<T> >(source);
00270                 if (ds)
00271                     write(ds->get());
00272                 else
00273                     log(Error) << "trying to write from an incompatible data source" << endlog();
00274             }
00275         }
00276 
00278         virtual const types::TypeInfo* getTypeInfo() const
00279         { return internal::DataSourceTypeInfo<T>::getTypeInfo(); }
00280 
00284         virtual base::PortInterface* clone() const
00285         { return new OutputPort<T>(this->getName()); }
00286 
00292         virtual base::PortInterface* antiClone() const
00293         { return new InputPort<T>(this->getName()); }
00294 
00295         using base::OutputPortInterface::createConnection;
00296 
00299         virtual bool createConnection(base::InputPortInterface& input_port, ConnPolicy const& policy)
00300         {
00301             return internal::ConnFactory::createConnection(*this, input_port, policy);
00302         }
00303 
00304         virtual bool createStream(ConnPolicy const& policy)
00305         {
00306             return internal::ConnFactory::createStream(*this, policy);
00307         }
00308 
00309 #ifndef ORO_DISABLE_PORT_DATA_SCRIPTING
00310 
00314         virtual Service* createPortObject()
00315         {
00316             Service* object = base::OutputPortInterface::createPortObject();
00317             // Force resolution on the overloaded write method
00318             typedef void (OutputPort<T>::*WriteSample)(T const&);
00319             WriteSample write_m = &OutputPort::write;
00320             typedef T (OutputPort<T>::*LastSample)() const;
00321             LastSample last_m = &OutputPort::getLastWrittenValue;
00322             object->addSynchronousOperation("write", write_m, this).doc("Writes a sample on the port.").arg("sample", "");
00323             object->addSynchronousOperation("last", last_m, this).doc("Returns last written value to this port.");
00324             return object;
00325         }
00326 #endif
00327     };
00328 
00329 }
00330 
00331 #endif
00332