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: 2009-06-26 00021 ** Authors: 00022 ** Marc Wathelet 00023 ** Marc Wathelet (LGIT, Grenoble, France) 00024 ** 00025 ***************************************************************************/ 00026 00027 #ifndef FLETCHERCHECKSUM_H 00028 #define FLETCHERCHECKSUM_H 00029 00030 #include <stdio.h> 00031 00032 #include "GpCoreToolsDLLExport.h" 00033 00034 namespace GpCoreTools { 00035 00036 class GPCORETOOLS_EXPORT FletcherChecksum 00037 { 00038 public: 00039 FletcherChecksum() {_values.a=0; _values.b=0;} 00040 FletcherChecksum(unsigned char a, unsigned char b) {_values.a=a; _values.b=b;} 00041 FletcherChecksum(const FletcherChecksum& o) {_raw=o._raw;} 00042 00043 bool operator==(const FletcherChecksum& o) const {return _raw==o._raw;} 00044 00045 void reset() {_values.a=0; _values.b=0;} 00046 inline void add(const char * buffer, int length); 00047 00048 unsigned char a() const {return _values.a;} 00049 unsigned char b() const {return _values.b;} 00050 private: 00051 union { 00052 struct { 00053 unsigned char a, b; 00054 } _values; 00055 unsigned char _bytes[2]; 00056 unsigned short _raw; 00057 }; 00058 }; 00059 00060 inline void FletcherChecksum::add(const char * buffer, int length) 00061 { 00062 for(int i=0; i<length; i++) { 00063 _values.a+=buffer[i]; 00064 _values.b+=_values.a; 00065 } 00066 } 00067 00068 } // namespace GpCoreTools 00069 00070 #endif // FLETCHERCHECKSUM_H
