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35 lines
718 B
C
35 lines
718 B
C
/* 7zCrc.c -- CRC32 calculation
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2008-08-05
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Igor Pavlov
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Public domain */
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#include "7zCrc.h"
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#define kCrcPoly 0xEDB88320
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UInt32 g_CrcTable[256];
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void MY_FAST_CALL CrcGenerateTable(void)
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{
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UInt32 i;
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for (i = 0; i < 256; i++)
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{
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UInt32 r = i;
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int j;
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for (j = 0; j < 8; j++)
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r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1));
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g_CrcTable[i] = r;
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}
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}
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UInt32 MY_FAST_CALL CrcUpdate(UInt32 v, const void *data, size_t size)
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{
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const Byte *p = (const Byte *)data;
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for (; size > 0 ; size--, p++)
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v = CRC_UPDATE_BYTE(v, *p);
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return v;
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}
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UInt32 MY_FAST_CALL CrcCalc(const void *data, size_t size)
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{
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return CrcUpdate(CRC_INIT_VAL, data, size) ^ 0xFFFFFFFF;
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}
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