1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/win32/7zip/7z/CPP/7zip/Archive/Lzh/LzhCRC.cpp	Sat Mar 03 10:31:27 2012 -0600
     1.3 @@ -0,0 +1,43 @@
     1.4 +// LzhCRC.cpp
     1.5 +
     1.6 +#include "StdAfx.h"
     1.7 +
     1.8 +#include "LzhCRC.h"
     1.9 +
    1.10 +namespace NArchive {
    1.11 +namespace NLzh {
    1.12 +
    1.13 +static const UInt16 kCRCPoly = 0xA001;
    1.14 +
    1.15 +UInt16 CCRC::Table[256];
    1.16 +
    1.17 +void CCRC::InitTable()
    1.18 +{
    1.19 +  for (UInt32 i = 0; i < 256; i++)
    1.20 +  {
    1.21 +    UInt32 r = i;
    1.22 +    for (int j = 0; j < 8; j++)
    1.23 +      if (r & 1)
    1.24 +        r = (r >> 1) ^ kCRCPoly;
    1.25 +      else
    1.26 +        r >>= 1;
    1.27 +    CCRC::Table[i] = (UInt16)r;
    1.28 +  }
    1.29 +}
    1.30 +
    1.31 +class CCRCTableInit
    1.32 +{
    1.33 +public:
    1.34 +  CCRCTableInit() { CCRC::InitTable(); }
    1.35 +} g_CRCTableInit;
    1.36 +
    1.37 +void CCRC::Update(const void *data, size_t size)
    1.38 +{
    1.39 +  UInt16 v = _value;
    1.40 +  const Byte *p = (const Byte *)data;
    1.41 +  for (; size > 0; size--, p++)
    1.42 +    v = (UInt16)(Table[((Byte)(v)) ^ *p] ^ (v >> 8));
    1.43 +  _value = v;
    1.44 +}
    1.45 +
    1.46 +}}