00001 /*************************************************************************** 00002 ** 00003 ** This file is part of QGpCoreTools. 00004 ** 00005 ** This library is free software; you can redistribute it and/or 00006 ** modify it under the terms of the GNU Lesser General Public 00007 ** License as published by the Free Software Foundation; either 00008 ** version 2.1 of the License, or (at your option) any later version. 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 Lesser General Public 00013 ** License for more details. 00014 ** 00015 ** You should have received a copy of the GNU Lesser General Public 00016 ** License along with this library; if not, write to the Free Software 00017 ** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00018 ** 00019 ** 00020 ** 00021 ** Created: 2012-02-08 00022 ** Authors: 00023 ** Marc Wathelet (ISTerre, Grenoble, France) 00024 ** 00025 ***************************************************************************/ 00026 00027 #ifndef FLETCHERCHECKSUM_H 00028 #define FLETCHERCHECKSUM_H 00029 00030 #include "QGpCoreToolsDLLExport.h" 00031 00032 namespace QGpCoreTools { 00033 00034 class QGPCORETOOLS_EXPORT FletcherChecksum 00035 { 00036 public: 00037 FletcherChecksum() {_values.a=0; _values.b=0;} 00038 FletcherChecksum(unsigned char a, unsigned char b) {_values.a=a; _values.b=b;} 00039 FletcherChecksum(const FletcherChecksum& o) {_raw=o._raw;} 00040 00041 bool operator==(const FletcherChecksum& o) const {return _raw==o._raw;} 00042 00043 void reset() {_values.a=0; _values.b=0;} 00044 inline void add(const char * buffer, int length); 00045 00046 unsigned char a() const {return _values.a;} 00047 unsigned char b() const {return _values.b;} 00048 private: 00049 union { 00050 struct { 00051 unsigned char a, b; 00052 } _values; 00053 unsigned char _bytes[2]; 00054 unsigned short _raw; 00055 }; 00056 }; 00057 00058 inline void FletcherChecksum::add(const char * buffer, int length) 00059 { 00060 for(int i=0; i<length; i++) { 00061 _values.a+=buffer[i]; 00062 _values.b+=_values.a; 00063 } 00064 } 00065 00066 } // namespace QGpCoreTools 00067 00068 #endif // FLETCHERCHECKSUM_H
