00001 /*************************************************************************** 00002 tag: Peter Soetens Thu Oct 22 11:59:08 CEST 2009 ChannelBufferElement.hpp 00003 00004 ChannelBufferElement.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 * 00032 * License along with this library; if not, write to the Free Software * 00033 * Foundation, Inc., 59 Temple Place, * 00034 * Suite 330, Boston, MA 02111-1307 USA * 00035 * * 00036 ***************************************************************************/ 00037 00038 00039 #ifndef ORO_CHANNEL_BUFFER_ELEMENT_HPP 00040 #define ORO_CHANNEL_BUFFER_ELEMENT_HPP 00041 00042 #include "../base/ChannelElement.hpp" 00043 #include "../base/BufferInterface.hpp" 00044 00045 namespace RTT { namespace internal { 00046 00049 template<typename T> 00050 class ChannelBufferElement : public base::ChannelElement<T> 00051 { 00052 typename base::BufferInterface<T>::shared_ptr buffer; 00053 typename base::ChannelElement<T>::value_t *last_sample_p; 00054 public: 00055 typedef typename base::ChannelElement<T>::param_t param_t; 00056 typedef typename base::ChannelElement<T>::reference_t reference_t; 00057 typedef typename base::ChannelElement<T>::value_t value_t; 00058 00059 ChannelBufferElement(typename base::BufferInterface<T>::shared_ptr buffer) 00060 : buffer(buffer), last_sample_p(0) {} 00061 00062 virtual ~ChannelBufferElement() 00063 { 00064 if(last_sample_p) 00065 buffer->Release(last_sample_p); 00066 } 00067 00072 virtual bool write(param_t sample) 00073 { 00074 if (buffer->Push(sample)) 00075 return this->signal(); 00076 return true; 00077 } 00078 00083 virtual FlowStatus read(reference_t sample, bool copy_old_data) 00084 { 00085 value_t *new_sample_p; 00086 if ( (new_sample_p = buffer->PopWithoutRelease()) ) { 00087 if(last_sample_p) 00088 buffer->Release(last_sample_p); 00089 00090 last_sample_p = new_sample_p; 00091 sample = *new_sample_p; 00092 return NewData; 00093 } 00094 if (last_sample_p) { 00095 if(copy_old_data) 00096 sample = *(last_sample_p); 00097 return OldData; 00098 } 00099 return NoData; 00100 } 00101 00106 virtual void clear() 00107 { 00108 if(last_sample_p) 00109 buffer->Release(last_sample_p); 00110 last_sample_p = 0; 00111 buffer->clear(); 00112 base::ChannelElement<T>::clear(); 00113 } 00114 00115 virtual bool data_sample(param_t sample) 00116 { 00117 buffer->data_sample(sample); 00118 return base::ChannelElement<T>::data_sample(sample); 00119 } 00120 00121 virtual T data_sample() 00122 { 00123 return buffer->data_sample(); 00124 } 00125 }; 00126 }} 00127 00128 #endif 00129