00001 /*************************************************************************** 00002 ** 00003 ** This file is part of GpCoreTools. 00004 ** 00005 ** This file may be distributed and/or modified under the terms of the 00006 ** GNU General Public License version 2 or 3 as published by the Free 00007 ** Software Foundation and appearing in the file LICENSE.GPL included 00008 ** in the packaging of this file. 00009 ** 00010 ** This file is distributed in the hope that it will be useful, but WITHOUT 00011 ** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 00012 ** FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 00013 ** more details. 00014 ** 00015 ** You should have received a copy of the GNU General Public License 00016 ** along with this program. If not, see <http://www.gnu.org/licenses/>. 00017 ** 00018 ** See http://www.geopsy.org for more information. 00019 ** 00020 ** Created: 2011-06-20 00021 ** Authors: 00022 ** Marc Wathelet (ISTerre, Grenoble, France) 00023 ** 00024 ***************************************************************************/ 00025 00026 #ifndef MESSAGERAWHEADER_H 00027 #define MESSAGERAWHEADER_H 00028 00029 #include "GpCoreToolsDLLExport.h" 00030 #include "FletcherChecksum.h" 00031 #include "ByteOrder.h" 00032 00033 namespace GpCoreTools { 00034 00035 #pragma pack(1) /* set alignment to 1 byte boundary */ 00036 00037 class GPCORETOOLS_EXPORT MessageRawHeader 00038 { 00039 public: 00040 MessageRawHeader() {} 00041 inline MessageRawHeader(unsigned int length); 00042 inline MessageRawHeader(const MessageRawHeader& o); 00043 00044 enum {SynchronizationSize=2, HeaderSize=2, CheckSumSize=2}; 00045 00046 bool isValid() const {return _sync[0]==0xB5 && _sync[1]==0x62;} 00047 inline bool isValid(const FletcherChecksum& cksum, const char * payload=0, 00048 unsigned short payloadLength=0) const; 00049 00050 inline void littleEndianValues(); 00051 inline void bigEndianValues(); 00052 00053 const char * header() const {return _bytes;} 00054 00055 unsigned int lengthLittleEndian() const {return ByteOrder::littleEndianToNative(_values.length);} 00056 unsigned int lengthBigEndian() const {return ByteOrder::bigEndianToNative(_values.length);} 00057 protected: 00058 unsigned char _sync[2]; 00059 union { 00060 struct { 00061 unsigned short length; 00062 } _values; 00063 char _bytes[HeaderSize]; 00064 }; 00065 }; 00066 00067 inline MessageRawHeader::MessageRawHeader(unsigned int length) 00068 { 00069 _sync[0]=0xB5; 00070 _sync[1]=0x62; 00071 _values.length=length; 00072 } 00073 00074 inline MessageRawHeader::MessageRawHeader(const MessageRawHeader& o) 00075 { 00076 _sync[0]=o._sync[0]; 00077 _sync[1]=o._sync[1]; 00078 _values.length=o._values.length; 00079 } 00080 00081 inline void MessageRawHeader::bigEndianValues() 00082 { 00083 #if BYTE_ORDER==LITTLE_ENDIAN 00084 ByteOrder::swap(_bytes[0], _bytes[1]); 00085 #endif 00086 } 00087 00088 inline void MessageRawHeader::littleEndianValues() 00089 { 00090 #if BYTE_ORDER==BIG_ENDIAN 00091 ByteOrder::swap(_bytes[0], _bytes[1]); 00092 #endif 00093 } 00094 00095 inline bool MessageRawHeader::isValid(const FletcherChecksum& cksum, const char * payload, 00096 unsigned short payloadLength) const 00097 { 00098 FletcherChecksum mycs; 00099 mycs.add(reinterpret_cast<const char *>(header()), HeaderSize); 00100 if(payload) { 00101 mycs.add(payload, payloadLength); 00102 } 00103 return cksum==mycs; 00104 } 00105 00106 #pragma pack() // restore original alignment 00107 00108 } // namespace GpCoreTools 00109 00110 #endif // MESSAGERAWHEADER_H
