nux-0.9.46
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00001 /* 00002 * Copyright 2010 Inalogic® Inc. 00003 * 00004 * This program is free software: you can redistribute it and/or modify it 00005 * under the terms of the GNU Lesser General Public License, as 00006 * published by the Free Software Foundation; either version 2.1 or 3.0 00007 * of the License. 00008 * 00009 * This program is distributed in the hope that it will be useful, but 00010 * WITHOUT ANY WARRANTY; without even the implied warranties of 00011 * MERCHANTABILITY, SATISFACTORY QUALITY or FITNESS FOR A PARTICULAR 00012 * PURPOSE. See the applicable version of the GNU Lesser General Public 00013 * License for more details. 00014 * 00015 * You should have received a copy of both the GNU Lesser General Public 00016 * License along with this program. If not, see <http://www.gnu.org/licenses/> 00017 * 00018 * Authored by: Jay Taoko <jaytaoko@inalogic.com> 00019 * 00020 */ 00021 00022 00023 #ifndef CRC32_H 00024 #define CRC32_H 00025 00026 namespace nux 00027 { 00028 // http://www.networkdls.com/Software.Asp?Review=22 00029 00030 // This is the official polynomial used by CRC-32 in PKZip, WinZip and Ethernet. 00031 00032 // There are multiple 16-bit CRC polynomials in common use, but this is *the* standard CRC-32 polynomial, 00033 // first popularized by Ethernet. It is used by PKZip, WinZip and Ethernet. 00034 // x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0 00035 00036 // #define CRC32_POLYNOMIAL_LE 0xedb88320 // little Endian 00037 #define CRC32_POLYNOMIAL 0x04c11db7 // big Endian 00038 00039 // How many bits at a time to use. Requires a table of 4<<CRC_xx_BITS bytes. We use CRC_8_BITS 00040 // CRC_xx_BITS must be a power of 2 between 1 and 8. We use CRC_8_BITS. 00041 #define CRC32BUFSZ 1024 // 4 << 8 = 1024 00042 00043 class CRC32 00044 { 00045 public: 00046 CRC32(); 00047 t_u32 FileCRC (const char *sFileName); 00048 t_u32 FullCRC (const char *sData, t_u32 ulLength); 00049 void PartialCRC (t_u32 *ulInCRC, const char *sData, t_u32 ulLength); 00050 00051 private: 00052 void Initialize (void); 00053 t_u32 Reflect (t_u32 ulReflect, char cChar); 00054 t_u32 CRCTable[256]; // CRC lookup table array. 00055 }; 00056 00057 } 00058 #endif // CRC32_H