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44 lines
695 B
C++
Executable File
44 lines
695 B
C++
Executable File
// LzhCRC.cpp
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#include "StdAfx.h"
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#include "LzhCRC.h"
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namespace NArchive {
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namespace NLzh {
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static const UInt16 kCRCPoly = 0xA001;
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UInt16 CCRC::Table[256];
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void CCRC::InitTable()
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{
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for (UInt32 i = 0; i < 256; i++)
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{
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UInt32 r = i;
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for (int j = 0; j < 8; j++)
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if (r & 1)
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r = (r >> 1) ^ kCRCPoly;
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else
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r >>= 1;
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CCRC::Table[i] = (UInt16)r;
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}
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}
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class CCRCTableInit
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{
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public:
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CCRCTableInit() { CCRC::InitTable(); }
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} g_CRCTableInit;
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void CCRC::Update(const void *data, size_t size)
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{
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UInt16 v = _value;
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const Byte *p = (const Byte *)data;
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for (; size > 0; size--, p++)
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v = Table[((Byte)(v)) ^ *p] ^ (v >> 8);
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_value = v;
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}
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}}
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