cbzip2inputstream.java

Use the links below to download a source distribution of Ant from one of our mirrors. It is good pra

            } else {
                if (++lastShadow >= limitLast) {
                    throw new IOException("block overrun");
                }

                final char tmp = yy[nextSym - 1];
                unzftab[seqToUnseq[tmp] & 0xff]++;
                ll8[lastShadow] = seqToUnseq[tmp];

                /*
                  This loop is hammered during decompression,
                  hence avoid native method call overhead of
                  System.arraycopy for very small ranges to copy.
                */
                if (nextSym <= 16) {
                    for (int j = nextSym - 1; j > 0;) {
                        yy[j] = yy[--j];
                    }
                } else {
                    System.arraycopy(yy, 0, yy, 1, nextSym - 1);
                }

                yy[0] = tmp;

                if (groupPos == 0) {
                    groupPos    = G_SIZE - 1;
                    zt          = selector[++groupNo] & 0xff;
                    base_zt     = base[zt];
                    limit_zt    = limit[zt];
                    perm_zt     = perm[zt];
                    minLens_zt  = minLens[zt];
                } else {
                    groupPos--;
                }

                int zn = minLens_zt;

                // Inlined:
                // int zvec = bsR(zn);
                while (bsLiveShadow < zn) {
                    final int thech = inShadow.read();
                    if (thech >= 0) {
                        bsBuffShadow = (bsBuffShadow << 8) | thech;
                        bsLiveShadow += 8;
                        continue;
                    } else {
                        throw new IOException("unexpected end of stream");
                    }
                }
                int zvec = (bsBuffShadow >> (bsLiveShadow - zn)) & ((1 << zn) - 1);
                bsLiveShadow -= zn;

                while (zvec > limit_zt[zn]) {
                    zn++;
                    while (bsLiveShadow < 1) {
                        final int thech = inShadow.read();
                        if (thech >= 0) {
                            bsBuffShadow = (bsBuffShadow << 8) | thech;
                            bsLiveShadow += 8;
                            continue;
                        } else {
                            throw new IOException("unexpected end of stream");
                        }
                    }
                    bsLiveShadow--;
                    zvec = (zvec << 1) | ((bsBuffShadow >> bsLiveShadow) & 1);
                }
                nextSym = perm_zt[zvec - base_zt[zn]];
            }
        }

        this.last = lastShadow;
        this.bsLive = bsLiveShadow;
        this.bsBuff = bsBuffShadow;
    }

    private int getAndMoveToFrontDecode0(final int groupNo)
        throws IOException {
        final InputStream inShadow  = this.in;
        final Data dataShadow  = this.data;
        final int zt          = dataShadow.selector[groupNo] & 0xff;
        final int[] limit_zt  = dataShadow.limit[zt];
        int zn = dataShadow.minLens[zt];
        int zvec = bsR(zn);
        int bsLiveShadow = this.bsLive;
        int bsBuffShadow = this.bsBuff;

        while (zvec > limit_zt[zn]) {
            zn++;
            while (bsLiveShadow < 1) {
                final int thech = inShadow.read();

                if (thech >= 0) {
                    bsBuffShadow = (bsBuffShadow << 8) | thech;
                    bsLiveShadow += 8;
                    continue;
                } else {
                    throw new IOException("unexpected end of stream");
                }
            }
            bsLiveShadow--;
            zvec = (zvec << 1) | ((bsBuffShadow >> bsLiveShadow) & 1);
        }

        this.bsLive = bsLiveShadow;
        this.bsBuff = bsBuffShadow;

        return dataShadow.perm[zt][zvec - dataShadow.base[zt][zn]];
    }

    private void setupBlock() throws IOException {
        if (this.data == null) {
            return;
        }

        final int[] cftab = this.data.cftab;
        final int[] tt    = this.data.initTT(this.last + 1);
        final byte[] ll8  = this.data.ll8;
        cftab[0] = 0;
        System.arraycopy(this.data.unzftab, 0, cftab, 1, 256);

        for (int i = 1, c = cftab[0]; i <= 256; i++) {
            c += cftab[i];
            cftab[i] = c;
        }

        for (int i = 0, lastShadow = this.last; i <= lastShadow; i++) {
            tt[cftab[ll8[i] & 0xff]++] = i;
        }

        if ((this.origPtr < 0) || (this.origPtr >= tt.length)) {
            throw new IOException("stream corrupted");
        }

        this.su_tPos = tt[this.origPtr];
        this.su_count = 0;
        this.su_i2 = 0;
        this.su_ch2 = 256;   /* not a char and not EOF */

        if (this.blockRandomised) {
            this.su_rNToGo = 0;
            this.su_rTPos = 0;
            setupRandPartA();
        } else {
            setupNoRandPartA();
        }
    }

    private void setupRandPartA() throws IOException {
        if (this.su_i2 <= this.last) {
            this.su_chPrev = this.su_ch2;
            int su_ch2Shadow = this.data.ll8[this.su_tPos] & 0xff;
            this.su_tPos = this.data.tt[this.su_tPos];
            if (this.su_rNToGo == 0) {
                this.su_rNToGo = BZip2Constants.rNums[this.su_rTPos] - 1;
                if (++this.su_rTPos == 512) {
                    this.su_rTPos = 0;
                }
            } else {
                this.su_rNToGo--;
            }
            this.su_ch2 = su_ch2Shadow ^= (this.su_rNToGo == 1) ? 1 : 0;
            this.su_i2++;
            this.currentChar = su_ch2Shadow;
            this.currentState = RAND_PART_B_STATE;
            this.crc.updateCRC(su_ch2Shadow);
        } else {
            endBlock();
            initBlock();
            setupBlock();
        }
    }

    private void setupNoRandPartA() throws IOException {
        if (this.su_i2 <= this.last) {
            this.su_chPrev = this.su_ch2;
            int su_ch2Shadow = this.data.ll8[this.su_tPos] & 0xff;
            this.su_ch2 = su_ch2Shadow;
            this.su_tPos = this.data.tt[this.su_tPos];
            this.su_i2++;
            this.currentChar = su_ch2Shadow;
            this.currentState = NO_RAND_PART_B_STATE;
            this.crc.updateCRC(su_ch2Shadow);
        } else {
            this.currentState = NO_RAND_PART_A_STATE;
            endBlock();
            initBlock();
            setupBlock();
        }
    }

    private void setupRandPartB() throws IOException {
        if (this.su_ch2 != this.su_chPrev) {
            this.currentState = RAND_PART_A_STATE;
            this.su_count = 1;
            setupRandPartA();
        } else if (++this.su_count >= 4) {
            this.su_z = (char) (this.data.ll8[this.su_tPos] & 0xff);
            this.su_tPos = this.data.tt[this.su_tPos];
            if (this.su_rNToGo == 0) {
                this.su_rNToGo = BZip2Constants.rNums[this.su_rTPos] - 1;
                if (++this.su_rTPos == 512) {
                    this.su_rTPos = 0;
                }
            } else {
                this.su_rNToGo--;
            }
            this.su_j2 = 0;
            this.currentState = RAND_PART_C_STATE;
            if (this.su_rNToGo == 1) {
                this.su_z ^= 1;
            }
            setupRandPartC();
        } else {
            this.currentState = RAND_PART_A_STATE;
            setupRandPartA();
        }
    }

    private void setupRandPartC() throws IOException {
        if (this.su_j2 < this.su_z) {
            this.currentChar = this.su_ch2;
            this.crc.updateCRC(this.su_ch2);
            this.su_j2++;
        } else {
            this.currentState = RAND_PART_A_STATE;
            this.su_i2++;
            this.su_count = 0;
            setupRandPartA();
        }
    }

    private void setupNoRandPartB() throws IOException {
        if (this.su_ch2 != this.su_chPrev) {
            this.su_count = 1;
            setupNoRandPartA();
        } else if (++this.su_count >= 4) {
            this.su_z = (char) (this.data.ll8[this.su_tPos] & 0xff);
            this.su_tPos = this.data.tt[this.su_tPos];
            this.su_j2 = 0;
            setupNoRandPartC();
        } else {
            setupNoRandPartA();
        }
    }

    private void setupNoRandPartC() throws IOException {
        if (this.su_j2 < this.su_z) {
            int su_ch2Shadow = this.su_ch2;
            this.currentChar = su_ch2Shadow;
            this.crc.updateCRC(su_ch2Shadow);
            this.su_j2++;
            this.currentState = NO_RAND_PART_C_STATE;
        } else {
            this.su_i2++;
            this.su_count = 0;
            setupNoRandPartA();
        }
    }

    private static final class Data extends Object {

        // (with blockSize 900k)
        final boolean[] inUse   = new boolean[256];                                   //      256 byte

        final byte[] seqToUnseq   = new byte[256];                                    //      256 byte
        final byte[] selector     = new byte[MAX_SELECTORS];                          //    18002 byte
        final byte[] selectorMtf  = new byte[MAX_SELECTORS];                          //    18002 byte

        /**
         * Freq table collected to save a pass over the data during
         * decompression.
         */
        final int[] unzftab = new int[256];                                           //     1024 byte

        final int[][] limit = new int[N_GROUPS][MAX_ALPHA_SIZE];                      //     6192 byte
        final int[][] base  = new int[N_GROUPS][MAX_ALPHA_SIZE];                      //     6192 byte
        final int[][] perm  = new int[N_GROUPS][MAX_ALPHA_SIZE];                      //     6192 byte
        final int[] minLens = new int[N_GROUPS];                                      //       24 byte

        final int[]     cftab     = new int[257];                                     //     1028 byte
        final char[]    getAndMoveToFrontDecode_yy = new char[256];                   //      512 byte
        final char[][]  temp_charArray2d  = new char[N_GROUPS][MAX_ALPHA_SIZE];       //     3096 byte
        final byte[] recvDecodingTables_pos = new byte[N_GROUPS];                     //        6 byte
        //---------------
        //    60798 byte

        int[] tt;                                                                     //  3600000 byte
        byte[] ll8;                                                                   //   900000 byte
        //---------------
        //  4560782 byte
        //===============

        Data(int blockSize100k) {
            super();

            this.ll8 = new byte[blockSize100k * BZip2Constants.baseBlockSize];
        }

        /**
         * Initializes the {@link #tt} array.
         *
         * This method is called when the required length of the array
         * is known.  I don't initialize it at construction time to
         * avoid unneccessary memory allocation when compressing small
         * files.
         */
        final int[] initTT(int length) {
            int[] ttShadow = this.tt;

            // tt.length should always be >= length, but theoretically
            // it can happen, if the compressor mixed small and large
            // blocks.  Normally only the last block will be smaller
            // than others.
            if ((ttShadow == null) || (ttShadow.length < length)) {
                this.tt = ttShadow = new int[length];
            }

            return ttShadow;
        }

    }
}