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// LzxDecoder.h
#ifndef __LZX_DECODER_H
#define __LZX_DECODER_H
#include "../ICoder.h"
#include "../Common/InBuffer.h"
#include "HuffmanDecoder.h"
#include "LzOutWindow.h"
#include "Lzx.h"
#include "Lzx86Converter.h"
namespace NCompress {
namespace NLzx {
namespace NBitStream {
const unsigned kNumBigValueBits = 8 * 4;
const unsigned kNumValueBits = 17;
const UInt32 kBitDecoderValueMask = (1 << kNumValueBits) - 1;
class CDecoder
{
CInBuffer m_Stream;
UInt32 m_Value;
unsigned m_BitPos;
public:
CDecoder() {}
bool Create(UInt32 bufferSize) { return m_Stream.Create(bufferSize); }
void SetStream(ISequentialInStream *s) { m_Stream.SetStream(s); }
void ReleaseStream() { m_Stream.ReleaseStream(); }
void Init()
{
m_Stream.Init();
m_BitPos = kNumBigValueBits;
}
UInt64 GetProcessedSize() const { return m_Stream.GetProcessedSize() - (kNumBigValueBits - m_BitPos) / 8; }
unsigned GetBitPosition() const { return m_BitPos & 0xF; }
void Normalize()
{
for (; m_BitPos >= 16; m_BitPos -= 16)
{
Byte b0 = m_Stream.ReadByte();
Byte b1 = m_Stream.ReadByte();
m_Value = (m_Value << 8) | b1;
m_Value = (m_Value << 8) | b0;
}
}
UInt32 GetValue(unsigned numBits) const
{
return ((m_Value >> ((32 - kNumValueBits) - m_BitPos)) & kBitDecoderValueMask) >> (kNumValueBits - numBits);
}
void MovePos(unsigned numBits)
{
m_BitPos += numBits;
Normalize();
}
UInt32 ReadBits(unsigned numBits)
{
UInt32 res = GetValue(numBits);
MovePos(numBits);
return res;
}
UInt32 ReadBitsBig(unsigned numBits)
{
unsigned numBits0 = numBits / 2;
unsigned numBits1 = numBits - numBits0;
UInt32 res = ReadBits(numBits0) << numBits1;
return res + ReadBits(numBits1);
}
bool ReadUInt32(UInt32 &v)
{
if (m_BitPos != 0)
return false;
v = ((m_Value >> 16) & 0xFFFF) | ((m_Value << 16) & 0xFFFF0000);
m_BitPos = kNumBigValueBits;
return true;
}
Byte DirectReadByte() { return m_Stream.ReadByte(); }
};
}
class CDecoder :
public ICompressCoder,
public CMyUnknownImp
{
NBitStream::CDecoder m_InBitStream;
CLzOutWindow m_OutWindowStream;
UInt32 m_RepDistances[kNumRepDistances];
UInt32 m_NumPosLenSlots;
bool m_IsUncompressedBlock;
bool m_AlignIsUsed;
NCompress::NHuffman::CDecoder<kNumHuffmanBits, kMainTableSize> m_MainDecoder;
NCompress::NHuffman::CDecoder<kNumHuffmanBits, kNumLenSymbols> m_LenDecoder;
NCompress::NHuffman::CDecoder<kNumHuffmanBits, kAlignTableSize> m_AlignDecoder;
NCompress::NHuffman::CDecoder<kNumHuffmanBits, kLevelTableSize> m_LevelDecoder;
Byte m_LastMainLevels[kMainTableSize];
Byte m_LastLenLevels[kNumLenSymbols];
Cx86ConvertOutStream *m_x86ConvertOutStreamSpec;
CMyComPtr<ISequentialOutStream> m_x86ConvertOutStream;
UInt32 m_UnCompressedBlockSize;
bool _keepHistory;
int _remainLen;
bool _skipByte;
bool _wimMode;
UInt32 ReadBits(unsigned numBits);
bool ReadTable(Byte *lastLevels, Byte *newLevels, UInt32 numSymbols);
bool ReadTables();
void ClearPrevLevels();
HRESULT CodeSpec(UInt32 size);
HRESULT CodeReal(ISequentialInStream *inStream, ISequentialOutStream *outStream,
const UInt64 *inSize, const UInt64 *outSize, ICompressProgressInfo *progress);
public:
CDecoder(bool wimMode = false);
MY_UNKNOWN_IMP
void ReleaseStreams();
STDMETHOD(Flush)();
STDMETHOD(Code)(ISequentialInStream *inStream, ISequentialOutStream *outStream,
const UInt64 *inSize, const UInt64 *outSize, ICompressProgressInfo *progress);
STDMETHOD(SetInStream)(ISequentialInStream *inStream);
STDMETHOD(ReleaseInStream)();
STDMETHOD(SetOutStreamSize)(const UInt64 *outSize);
HRESULT SetParams(unsigned numDictBits);
void SetKeepHistory(bool keepHistory) { _keepHistory = keepHistory; }
};
}}
#endif
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