1 // Base.java 2 3 package SevenZip.Compression.LZMA; 4 5 public class Base 6 { 7 public static final int kNumRepDistances = 4; 8 public static final int kNumStates = 12; 9 10 public static final int StateInit() 11 { 12 return 0; 13 } 14 15 public static final int StateUpdateChar(int index) 16 { 17 if (index < 4) 18 return 0; 19 if (index < 10) 20 return index - 3; 21 return index - 6; 22 } 23 24 public static final int StateUpdateMatch(int index) 25 { 26 return (index < 7 ? 7 : 10); 27 } 28 29 public static final int StateUpdateRep(int index) 30 { 31 return (index < 7 ? 8 : 11); 32 } 33 34 public static final int StateUpdateShortRep(int index) 35 { 36 return (index < 7 ? 9 : 11); 37 } 38 39 public static final boolean StateIsCharState(int index) 40 { 41 return index < 7; 42 } 43 44 public static final int kNumPosSlotBits = 6; 45 public static final int kDicLogSizeMin = 0; 46 // public static final int kDicLogSizeMax = 28; 47 // public static final int kDistTableSizeMax = kDicLogSizeMax * 2; 48 49 public static final int kNumLenToPosStatesBits = 2; // it's for speed optimization 50 public static final int kNumLenToPosStates = 1 << kNumLenToPosStatesBits; 51 52 public static final int kMatchMinLen = 2; 53 54 public static final int GetLenToPosState(int len) 55 { 56 len -= kMatchMinLen; 57 if (len < kNumLenToPosStates) 58 return len; 59 return (int)(kNumLenToPosStates - 1); 60 } 61 62 public static final int kNumAlignBits = 4; 63 public static final int kAlignTableSize = 1 << kNumAlignBits; 64 public static final int kAlignMask = (kAlignTableSize - 1); 65 66 public static final int kStartPosModelIndex = 4; 67 public static final int kEndPosModelIndex = 14; 68 public static final int kNumPosModels = kEndPosModelIndex - kStartPosModelIndex; 69 70 public static final int kNumFullDistances = 1 << (kEndPosModelIndex / 2); 71 72 public static final int kNumLitPosStatesBitsEncodingMax = 4; 73 public static final int kNumLitContextBitsMax = 8; 74 75 public static final int kNumPosStatesBitsMax = 4; 76 public static final int kNumPosStatesMax = (1 << kNumPosStatesBitsMax); 77 public static final int kNumPosStatesBitsEncodingMax = 4; 78 public static final int kNumPosStatesEncodingMax = (1 << kNumPosStatesBitsEncodingMax); 79 80 public static final int kNumLowLenBits = 3; 81 public static final int kNumMidLenBits = 3; 82 public static final int kNumHighLenBits = 8; 83 public static final int kNumLowLenSymbols = 1 << kNumLowLenBits; 84 public static final int kNumMidLenSymbols = 1 << kNumMidLenBits; 85 public static final int kNumLenSymbols = kNumLowLenSymbols + kNumMidLenSymbols + 86 (1 << kNumHighLenBits); 87 public static final int kMatchMaxLen = kMatchMinLen + kNumLenSymbols - 1; 88 } 89
