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117 lines
2.5 KiB
C
Executable file
117 lines
2.5 KiB
C
Executable file
#ifndef XADMASTER_CRC_C
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#define XADMASTER_CRC_C
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/* $Id: crc.c,v 1.5 2005/06/23 14:54:37 stoecker Exp $
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Information handling functions
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XAD library system for archive handling
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Copyright (C) 1998 and later by Dirk Stöcker <soft@dstoecker.de>
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "include/functions.h"
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/* NOTE: using (size--) as test in while condition produces a SAS-C bug */
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FUNCxadCalcCRC16 /* xadUINT16 id, xadUINT16 init, xadSize size,
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const xadUINT8 *buffer */
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{
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xadUINT16 crc;
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xadSize s = 0;
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crc = init;
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if(id == XADCRC16_ID1)
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{
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const xadUINT16 *tab;
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tab = xadMasterBase->xmb_CRCTable1;
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while(s++ < size)
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crc = tab[(crc ^ *buffer++) & 0xFF] ^ (crc >> 8);
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}
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else
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{
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xadUINT16 tab[256];
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MakeCRC16(tab, id);
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while(s++ < size)
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crc = tab[(crc ^ *buffer++) & 0xFF] ^ (crc >> 8);
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}
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return crc;
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}
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ENDFUNC
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FUNCxadCalcCRC32 /* xadUINT32 id, xadUINT32 init, xadSize size,
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const xadUINT8 *buffer */
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{
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xadUINT32 crc;
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xadSize s = 0;
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crc = init;
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if(id == XADCRC32_ID1)
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{
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const xadUINT32 *tab;
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tab = xadMasterBase->xmb_CRCTable2;
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while(s++ < size)
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crc = tab[(crc ^ *buffer++) & 0xFF] ^ (crc >> 8);
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}
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else
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{
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xadUINT32 tab[256];
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MakeCRC32(tab, id);
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while(s++ < size)
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crc = tab[(crc ^ *buffer++) & 0xFF] ^ (crc >> 8);
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}
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return crc;
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}
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ENDFUNC
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void MakeCRC16(xadUINT16 *buf, xadUINT16 ID)
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{
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xadUINT16 i, j, k;
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for(i = 0; i < 256; ++i)
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{
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k = i;
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for(j = 0; j < 8; ++j)
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{
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if(k & 1)
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k = (k >> 1) ^ ID;
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else
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k >>= 1;
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}
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buf[i] = k;
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}
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}
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void MakeCRC32(xadUINT32 *buf, xadUINT32 ID)
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{
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xadUINT32 i, j, k;
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for(i = 0; i < 256; ++i)
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{
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k = i;
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for(j = 0; j < 8; ++j)
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{
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if(k & 1)
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k = (k >> 1) ^ ID;
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else
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k >>= 1;
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}
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buf[i] = k;
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}
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}
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#endif /* XADMASTER_CRC_C */
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