lzma.h

经过项目量产验证的代码.开发环境是sparc+vxworks. 这个LZMA是专门为sparc做的优化压缩,性能是最好的.

// LZMA.h


#include "LenCoder.h"

#ifndef __LZMA_H
#define __LZMA_H

const int kNumRepDistances = 4;

const BYTE kNumStates = 12;

const BYTE kLiteralNextStates[kNumStates] = {0, 0, 0, 0, 1, 2, 3, 4,  5,  6,   4, 5};
const BYTE kMatchNextStates[kNumStates]   = {7, 7, 7, 7, 7, 7, 7, 10, 10, 10, 10, 10};
const BYTE kRepNextStates[kNumStates]     = {8, 8, 8, 8, 8, 8, 8, 11, 11, 11, 11, 11};
const BYTE kShortRepNextStates[kNumStates]= {9, 9, 9, 9, 9, 9, 9, 11, 11, 11, 11, 11};

class CState
{
public:
  BYTE m_Index;
  void Init()
    { m_Index = 0; }
  void UpdateChar()
    { m_Index = kLiteralNextStates[m_Index]; }
  void UpdateMatch()
    { m_Index = kMatchNextStates[m_Index]; }
  void UpdateRep()
    { m_Index = kRepNextStates[m_Index]; }
  void UpdateShortRep()
    { m_Index = kShortRepNextStates[m_Index]; }
};

const int kNumPosSlotBits = 6; 
const int kDicLogSizeMax = 28; 
const int kDistTableSizeMax = kDicLogSizeMax * 2; 

extern UINT32 kDistStart[kDistTableSizeMax];

const BYTE kDistDirectBits[kDistTableSizeMax] = 
{
  0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,
  10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 
  20, 20, 21, 21, 22, 22, 23, 23, 24, 24, 25, 25, 26, 26 
};

const int kNumLenToPosStates = 4;
inline int GetLenToPosState(int len)
{
  len -= 2;
  if (len < kNumLenToPosStates)
    return len;
  return kNumLenToPosStates - 1;
}

const int kMatchMinLen = 2;

const int kMatchMaxLen = kMatchMinLen + kLenNumSymbolsTotal - 1;

const int kNumAlignBits = 4;
const int kAlignTableSize = 1 << kNumAlignBits;
// const UINT32 kAlignMask = (kAlignTableSize - 1);

const int kStartPosModelIndex = 4;
const int kEndPosModelIndex = 14;
const int kNumPosModels = kEndPosModelIndex - kStartPosModelIndex;

const int kNumFullDistances = 1 << (kEndPosModelIndex / 2);


const int kMainChoiceLiteralIndex = 0;
const int kMainChoiceMatchIndex = 1;

const int kMatchChoiceDistanceIndex = 0;
const int kMatchChoiceRepetitionIndex = 1;

const int kNumLitPosStatesBitsEncodingMax = 4;
const int kNumLitContextBitsMax = 8;

#endif