CRangeDecoder.java

package LZMA;

import java.io.IOException;
import java.io.InputStream;

class CRangeDecoder {
    static final int kNumTopBits = 24;
    static final int kTopValue = 16777216;
    static final int kTopValueMask = -16777216;
    static final int kNumBitModelTotalBits = 11;
    static final int kBitModelTotal = 2048;
    static final int kNumMoveBits = 5;
    InputStream inStream;
    int Range;
    int Code;
    byte[] buffer;
    int buffer_size;
    int buffer_ind;
    static final int kNumPosBitsMax = 4;
    static final int kNumPosStatesMax = 16;
    static final int kLenNumLowBits = 3;
    static final int kLenNumLowSymbols = 8;
    static final int kLenNumMidBits = 3;
    static final int kLenNumMidSymbols = 8;
    static final int kLenNumHighBits = 8;
    static final int kLenNumHighSymbols = 256;
    static final int LenChoice = 0;
    static final int LenChoice2 = 1;
    static final int LenLow = 2;
    static final int LenMid = 130;
    static final int LenHigh = 258;
    static final int kNumLenProbs = 514;

    CRangeDecoder(InputStream paramInputStream)
            throws IOException {
        buffer = new byte[16384];
        inStream = paramInputStream;
        Code = 0;
        Range = -1;
        for (int i = 0; i < 5; i++)
            Code = (Code << 8 | Readbyte());
    }

    int Readbyte() throws IOException {
        if (buffer_size == buffer_ind) {
            buffer_size = inStream.read(buffer);
            buffer_ind = 0;

            if (buffer_size < 1)
                throw new LzmaException("LZMA : Data Error");
        }
        return buffer[(buffer_ind++)] & 0xFF;
    }

    int DecodeDirectBits(int paramInt) throws IOException {
        int i = 0;
        for (int j = paramInt; j > 0; j--) {
            Range >>>= 1;
            int k = Code - Range >>> 31;
            Code -= (Range & k - 1);
            i = i << 1 | 1 - k;

            if (Range >= 16777216)
                continue;
            Code = (Code << 8 | Readbyte());
            Range <<= 8;
        }

        return i;
    }

    int BitDecode(int[] paramArrayOfInt, int paramInt) throws IOException {
        int i = (Range >>> 11) * paramArrayOfInt[paramInt];
        if ((Code & 0xFFFFFFFF) < (i & 0xFFFFFFFF)) {
            Range = i;
            paramArrayOfInt[paramInt] += (2048 - paramArrayOfInt[paramInt] >>> 5);

            if ((Range & 0xFF000000) == 0) {
                Code = (Code << 8 | Readbyte());
                Range <<= 8;
            }
            return 0;
        }
        Range -= i;
        Code -= i;
        paramArrayOfInt[paramInt] -= (paramArrayOfInt[paramInt] >>> 5);

        if ((Range & 0xFF000000) == 0) {
            Code = (Code << 8 | Readbyte());
            Range <<= 8;
        }
        return 1;
    }

    int BitTreeDecode(int[] paramArrayOfInt, int paramInt1, int paramInt2) throws IOException {
        int i = 1;
        for (int j = paramInt2; j > 0; j--) {
            i = i + i + BitDecode(paramArrayOfInt, paramInt1 + i);
        }
        return i - (1 << paramInt2);
    }

    int ReverseBitTreeDecode(int[] paramArrayOfInt, int paramInt1, int paramInt2) throws IOException {
        int i = 1;
        int j = 0;

        for (int k = 0; k < paramInt2; k++) {
            int m = BitDecode(paramArrayOfInt, paramInt1 + i);
            i = i + i + m;
            j |= m << k;
        }
        return j;
    }

    byte LzmaLiteralDecode(int[] paramArrayOfInt, int paramInt) throws IOException {
        int i = 1;
        do
            i = i + i | BitDecode(paramArrayOfInt, paramInt + i);
        while (i < 256);

        return (byte) i;
    }

    byte LzmaLiteralDecodeMatch(int[] paramArrayOfInt, int paramInt, byte paramByte) throws IOException {
        int i = 1;
        do {
            int j = paramByte >> 7 & 0x1;
            paramByte = (byte) (paramByte << 1);
            int k = BitDecode(paramArrayOfInt, paramInt + (1 + j << 8) + i);
            i = i << 1 | k;

            if (j != k) {
                while (i < 256) {
                    i = i + i | BitDecode(paramArrayOfInt, paramInt + i);
                }
            }
        }
        while (i < 256);

        return (byte) i;
    }

    int LzmaLenDecode(int[] paramArrayOfInt, int paramInt1, int paramInt2)
            throws IOException {
        if (BitDecode(paramArrayOfInt, paramInt1 + 0) == 0) {
            return BitTreeDecode(paramArrayOfInt, paramInt1 + 2 + (paramInt2 << 3), 3);
        }

        if (BitDecode(paramArrayOfInt, paramInt1 + 1) == 0) {
            return 8 + BitTreeDecode(paramArrayOfInt, paramInt1 + 130 + (paramInt2 << 3), 3);
        }

        return 16 + BitTreeDecode(paramArrayOfInt, paramInt1 + 258, 8);
    }
}