Files
easy7zip/7zip/Compress/Arj/Decoder2.cpp
Igor Pavlov 8c1b5c7b7e 3.13
2016-05-28 00:15:41 +01:00

96 lines
2.3 KiB
C++
Executable File

// Arj/Decoder2.cpp
#include "StdAfx.h"
#include "Decoder2.h"
#include "Windows/Defs.h"
namespace NCompress{
namespace NArj {
namespace NDecoder2 {
static const UINT32 kHistorySize = 26624;
static const UINT32 kMatchMaxLen = 256;
static const UINT32 kMatchMinLen = 3;
CCoder::CCoder()
{}
STDMETHODIMP CCoder::CodeReal(ISequentialInStream *inStream,
ISequentialOutStream *outStream, const UINT64 *inSize, const UINT64 *outSize,
ICompressProgressInfo *progress)
{
if (outSize == NULL)
return E_INVALIDARG;
if (!m_OutWindowStream.IsCreated())
{
try { m_OutWindowStream.Create(kHistorySize); }
catch(...) { return E_OUTOFMEMORY; }
}
UINT64 pos = 0;
m_OutWindowStream.Init(outStream, false);
m_InBitStream.Init(inStream);
CCoderReleaser coderReleaser(this);
while(pos < *outSize)
{
const UINT32 kStartWidth = 0;
const UINT32 kStopWidth = 7;
UINT32 power = 1 << kStartWidth;
UINT32 width;
UINT32 len = 0;
for (width = kStartWidth; width < kStopWidth; width++)
{
if (m_InBitStream.ReadBits(1) == 0)
break;
len += power;
power <<= 1;
}
if (width != 0)
len += m_InBitStream.ReadBits(width);
if (len == 0)
{
m_OutWindowStream.PutOneByte(m_InBitStream.ReadBits(8));
pos++;
continue;
}
else
{
len = len - 1 + kMatchMinLen;
const UINT32 kStartWidth = 9;
const UINT32 kStopWidth = 13;
UINT32 power = 1 << kStartWidth;
UINT32 width;
UINT32 distance = 0;
for (width = kStartWidth; width < kStopWidth; width++)
{
if (m_InBitStream.ReadBits(1) == 0)
break;
distance += power;
power <<= 1;
}
if (width != 0)
distance += m_InBitStream.ReadBits(width);
if (distance >= pos)
throw "data error";
m_OutWindowStream.CopyBackBlock(distance, len);
pos += len;
}
}
return m_OutWindowStream.Flush();
}
STDMETHODIMP CCoder::Code(ISequentialInStream *inStream,
ISequentialOutStream *outStream, const UINT64 *inSize, const UINT64 *outSize,
ICompressProgressInfo *progress)
{
try { return CodeReal(inStream, outStream, inSize, outSize, progress);}
catch(const CInBufferException &e) { return e.ErrorCode; }
catch(const CLZOutWindowException &e) { return e.ErrorCode; }
catch(...) { return S_FALSE; }
}
}}}