Orocos Real-Time Toolkit  2.5.0
ChannelDataElement.hpp
00001 /***************************************************************************
00002   tag: Peter Soetens  Thu Oct 22 11:59:08 CEST 2009  ChannelDataElement.hpp
00003 
00004                         ChannelDataElement.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,       *
00027  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
00028  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
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_CHANNEL_DATA_ELEMENT_HPP
00040 #define ORO_CHANNEL_DATA_ELEMENT_HPP
00041 
00042 #include "../base/ChannelElement.hpp"
00043 #include "../base/DataObjectInterface.hpp"
00044 
00045 namespace RTT { namespace internal {
00046 
00049     template<typename T>
00050     class ChannelDataElement : public base::ChannelElement<T>
00051     {
00052         bool written, mread;
00053         typename base::DataObjectInterface<T>::shared_ptr data;
00054 
00055     public:
00056         typedef typename base::ChannelElement<T>::param_t param_t;
00057         typedef typename base::ChannelElement<T>::reference_t reference_t;
00058 
00059         ChannelDataElement(typename base::DataObjectInterface<T>::shared_ptr sample)
00060             : written(false), mread(false), data(sample) {}
00061 
00064         virtual bool write(param_t sample)
00065         {
00066             data->Set(sample);
00067             written = true;
00068             mread = false;
00069             return this->signal();
00070         }
00071 
00076         virtual FlowStatus read(reference_t sample, bool copy_old_data)
00077         {
00078             if (written)
00079             {
00080                 if ( !mread ) {
00081             data->Get(sample);
00082                     mread = true;
00083                     return NewData;
00084                 }
00085 
00086         if(copy_old_data)
00087             data->Get(sample);
00088 
00089                 return OldData;
00090             }
00091             return NoData;
00092         }
00093 
00097         virtual void clear()
00098         {
00099             written = false;
00100             mread = false;
00101             base::ChannelElement<T>::clear();
00102         }
00103 
00104         virtual bool data_sample(param_t sample)
00105         {
00106             data->data_sample(sample);
00107             return base::ChannelElement<T>::data_sample(sample);
00108         }
00109 
00110     };
00111 }}
00112 
00113 #endif
00114