1 // LZMA.h

     2 

     3 #ifndef __LZMA_H

     4 #define __LZMA_H

     5 

     6 namespace NCompress {

     7 namespace NLZMA {

     8 

     9 const UInt32 kNumRepDistances = 4;

    10 

    11 const int kNumStates = 12;

    12 

    13 const Byte kLiteralNextStates[kNumStates] = {0, 0, 0, 0, 1, 2, 3, 4,  5,  6,   4, 5};

    14 const Byte kMatchNextStates[kNumStates]   = {7, 7, 7, 7, 7, 7, 7, 10, 10, 10, 10, 10};

    15 const Byte kRepNextStates[kNumStates]     = {8, 8, 8, 8, 8, 8, 8, 11, 11, 11, 11, 11};

    16 const Byte kShortRepNextStates[kNumStates]= {9, 9, 9, 9, 9, 9, 9, 11, 11, 11, 11, 11};

    17 

    18 class CState

    19 {

    20 public:

    21   Byte Index;

    22   void Init() { Index = 0; }

    23   void UpdateChar() { Index = kLiteralNextStates[Index]; }

    24   void UpdateMatch() { Index = kMatchNextStates[Index]; }

    25   void UpdateRep() { Index = kRepNextStates[Index]; }

    26   void UpdateShortRep() { Index = kShortRepNextStates[Index]; }

    27   bool IsCharState() const { return Index < 7; }

    28 };

    29 

    30 const int kNumPosSlotBits = 6; 

    31 const int kDicLogSizeMin = 0; 

    32 const int kDicLogSizeMax = 32; 

    33 const int kDistTableSizeMax = kDicLogSizeMax * 2; 

    34 

    35 const UInt32 kNumLenToPosStates = 4;

    36 

    37 inline UInt32 GetLenToPosState(UInt32 len)

    38 {

    39   len -= 2;

    40   if (len < kNumLenToPosStates)

    41     return len;

    42   return kNumLenToPosStates - 1;

    43 }

    44 

    45 namespace NLength {

    46 

    47 const int kNumPosStatesBitsMax = 4;

    48 const UInt32 kNumPosStatesMax = (1 << kNumPosStatesBitsMax);

    49 

    50 const int kNumPosStatesBitsEncodingMax = 4;

    51 const UInt32 kNumPosStatesEncodingMax = (1 << kNumPosStatesBitsEncodingMax);

    52 

    53 const int kNumLowBits = 3;

    54 const int kNumMidBits = 3;

    55 const int kNumHighBits = 8;

    56 const UInt32 kNumLowSymbols = 1 << kNumLowBits;

    57 const UInt32 kNumMidSymbols = 1 << kNumMidBits;

    58 const UInt32 kNumSymbolsTotal = kNumLowSymbols + kNumMidSymbols + (1 << kNumHighBits);

    59 

    60 }

    61 

    62 const UInt32 kMatchMinLen = 2;

    63 const UInt32 kMatchMaxLen = kMatchMinLen + NLength::kNumSymbolsTotal - 1;

    64 

    65 const int kNumAlignBits = 4;

    66 const UInt32 kAlignTableSize = 1 << kNumAlignBits;

    67 const UInt32 kAlignMask = (kAlignTableSize - 1);

    68 

    69 const UInt32 kStartPosModelIndex = 4;

    70 const UInt32 kEndPosModelIndex = 14;

    71 const UInt32 kNumPosModels = kEndPosModelIndex - kStartPosModelIndex;

    72 

    73 const UInt32 kNumFullDistances = 1 << (kEndPosModelIndex / 2);

    74 

    75 const int kNumLitPosStatesBitsEncodingMax = 4;

    76 const int kNumLitContextBitsMax = 8;

    77 

    78 const int kNumMoveBits = 5;

    79 

    80 }}

    81 

    82 #endif