cbzip2outputstream.java

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

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

/*
 * This package is based on the work done by Keiron Liddle, Aftex Software
 * <[e-mail]> to whom the Ant project is very grateful for his
 * great code.
 */

package org.apache.tools.bzip2;

import java.io.OutputStream;
import java.io.IOException;

/**
 * An output stream that compresses into the BZip2 format (without the file
 * header chars) into another stream.
 *
 * TODO:    Update to BZip2 1.0.1
 */
public class CBZip2OutputStream extends OutputStream implements BZip2Constants {
    protected static final int SETMASK = (1 << 21);
    protected static final int CLEARMASK = (~SETMASK);
    protected static final int GREATER_ICOST = 15;
    protected static final int LESSER_ICOST = 0;
    protected static final int SMALL_THRESH = 20;
    protected static final int DEPTH_THRESH = 10;

    /*
      If you are ever unlucky/improbable enough
      to get a stack overflow whilst sorting,
      increase the following constant and try
      again.  In practice I have never seen the
      stack go above 27 elems, so the following
      limit seems very generous.
    */
    protected static final int QSORT_STACK_SIZE = 1000;

    private static void panic() {
        System.out.println("panic");
        //throw new CError();
    }

    private void makeMaps() {
        int i;
        nInUse = 0;
        for (i = 0; i < 256; i++) {
            if (inUse[i]) {
                seqToUnseq[nInUse] = (char) i;
                unseqToSeq[i] = (char) nInUse;
                nInUse++;
            }
        }
    }

    protected static void hbMakeCodeLengths(char[] len, int[] freq,
                                            int alphaSize, int maxLen) {
        /*
          Nodes and heap entries run from 1.  Entry 0
          for both the heap and nodes is a sentinel.
        */
        int nNodes, nHeap, n1, n2, i, j, k;
        boolean  tooLong;

        int[] heap = new int[MAX_ALPHA_SIZE + 2];
        int[] weight = new int[MAX_ALPHA_SIZE * 2];
        int[] parent = new int[MAX_ALPHA_SIZE * 2];

        for (i = 0; i < alphaSize; i++) {
            weight[i + 1] = (freq[i] == 0 ? 1 : freq[i]) << 8;
        }

        while (true) {
            nNodes = alphaSize;
            nHeap = 0;

            heap[0] = 0;
            weight[0] = 0;
            parent[0] = -2;

            for (i = 1; i <= alphaSize; i++) {
                parent[i] = -1;
                nHeap++;
                heap[nHeap] = i;
                {
                    int zz, tmp;
                    zz = nHeap;
                    tmp = heap[zz];
                    while (weight[tmp] < weight[heap[zz >> 1]]) {
                        heap[zz] = heap[zz >> 1];
                        zz >>= 1;
                    }
                    heap[zz] = tmp;
                }
            }
            if (!(nHeap < (MAX_ALPHA_SIZE + 2))) {
                panic();
            }

            while (nHeap > 1) {
                n1 = heap[1];
                heap[1] = heap[nHeap];
                nHeap--;
                {
                    int zz = 0, yy = 0, tmp = 0;
                    zz = 1;
                    tmp = heap[zz];
                    while (true) {
                        yy = zz << 1;
                        if (yy > nHeap) {
                            break;
                        }
                        if (yy < nHeap
                            && weight[heap[yy + 1]] < weight[heap[yy]]) {
                            yy++;
                        }
                        if (weight[tmp] < weight[heap[yy]]) {
                            break;
                        }
                        heap[zz] = heap[yy];
                        zz = yy;
                    }
                    heap[zz] = tmp;
                }
                n2 = heap[1];
                heap[1] = heap[nHeap];
                nHeap--;
                {
                    int zz = 0, yy = 0, tmp = 0;
                    zz = 1;
                    tmp = heap[zz];
                    while (true) {
                        yy = zz << 1;
                        if (yy > nHeap) {
                            break;
                        }
                        if (yy < nHeap
                            && weight[heap[yy + 1]] < weight[heap[yy]]) {
                            yy++;
                        }
                        if (weight[tmp] < weight[heap[yy]]) {
                            break;
                        }
                        heap[zz] = heap[yy];
                        zz = yy;
                    }
                    heap[zz] = tmp;
                }
                nNodes++;
                parent[n1] = parent[n2] = nNodes;

                weight[nNodes] = ((weight[n1] & 0xffffff00)
                                  + (weight[n2] & 0xffffff00))
                    | (1 + (((weight[n1] & 0x000000ff)
                            > (weight[n2] & 0x000000ff))
                            ? (weight[n1] & 0x000000ff)
                            : (weight[n2] & 0x000000ff)));

                parent[nNodes] = -1;
                nHeap++;
                heap[nHeap] = nNodes;
                {
                    int zz = 0, tmp = 0;
                    zz = nHeap;
                    tmp = heap[zz];
                    while (weight[tmp] < weight[heap[zz >> 1]]) {
                        heap[zz] = heap[zz >> 1];
                        zz >>= 1;
                    }
                    heap[zz] = tmp;
                }
            }
            if (!(nNodes < (MAX_ALPHA_SIZE * 2))) {
                panic();
            }

            tooLong = false;
            for (i = 1; i <= alphaSize; i++) {
                j = 0;
                k = i;
                while (parent[k] >= 0) {
                    k = parent[k];
                    j++;
                }
                len[i - 1] = (char) j;
                if (j > maxLen) {
                    tooLong = true;
                }
            }

            if (!tooLong) {
                break;
            }

            for (i = 1; i < alphaSize; i++) {
                j = weight[i] >> 8;
                j = 1 + (j / 2);
                weight[i] = j << 8;
            }
        }
    }

    /*
      index of the last char in the block, so
      the block size == last + 1.
    */
    int last;

    /*
      index in zptr[] of original string after sorting.
    */
    int origPtr;

    /*
      always: in the range 0 .. 9.
      The current block size is 100000 * this number.
    */
    int blockSize100k;

    boolean blockRandomised;

    int bytesOut;
    int bsBuff;
    int bsLive;
    CRC mCrc = new CRC();

    private boolean[] inUse = new boolean[256];
    private int nInUse;

    private char[] seqToUnseq = new char[256];
    private char[] unseqToSeq = new char[256];

    private char[] selector = new char[MAX_SELECTORS];
    private char[] selectorMtf = new char[MAX_SELECTORS];

    private char[] block;
    private int[] quadrant;
    private int[] zptr;
    private short[] szptr;
    private int[] ftab;

    private int nMTF;

    private int[] mtfFreq = new int[MAX_ALPHA_SIZE];

    /*
     * Used when sorting.  If too many long comparisons
     * happen, we stop sorting, randomise the block
     * slightly, and try again.
     */
    private int workFactor;
    private int workDone;
    private int workLimit;
    private boolean firstAttempt;
    private int nBlocksRandomised;

    private int currentChar = -1;
    private int runLength = 0;

    public CBZip2OutputStream(OutputStream inStream) throws IOException {
        this(inStream, 9);
    }

    public CBZip2OutputStream(OutputStream inStream, int inBlockSize)
        throws IOException {
        block = null;
        quadrant = null;
        zptr = null;
        ftab = null;

        bsSetStream(inStream);

        workFactor = 50;
        if (inBlockSize > 9) {
            inBlockSize = 9;
        }
        if (inBlockSize < 1) {
            inBlockSize = 1;
        }
        blockSize100k = inBlockSize;
        allocateCompressStructures();
        initialize();
        initBlock();
    }

    /**
     *
     * modified by Oliver Merkel, 010128
     *
     */
    public void write(int bv) throws IOException {
        int b = (256 + bv) % 256;
        if (currentChar != -1) {
            if (currentChar == b) {
                runLength++;
                if (runLength > 254) {
                    writeRun();
                    currentChar = -1;
                    runLength = 0;
                }
            } else {
                writeRun();
                runLength = 1;
                currentChar = b;
            }
        } else {
            currentChar = b;
            runLength++;
        }
    }

    private void writeRun() throws IOException {
        if (last < allowableBlockSize) {
            inUse[currentChar] = true;
            for (int i = 0; i < runLength; i++) {
                mCrc.updateCRC((char) currentChar);
            }
            switch (runLength) {
            case 1:
                last++;
                block[last + 1] = (char) currentChar;
                break;
            case 2:
                last++;
                block[last + 1] = (char) currentChar;
                last++;
                block[last + 1] = (char) currentChar;
                break;
            case 3:
                last++;
                block[last + 1] = (char) currentChar;
                last++;
                block[last + 1] = (char) currentChar;
                last++;
                block[last + 1] = (char) currentChar;
                break;
            default:
                inUse[runLength - 4] = true;
                last++;
                block[last + 1] = (char) currentChar;
                last++;
                block[last + 1] = (char) currentChar;
                last++;
                block[last + 1] = (char) currentChar;
                last++;
                block[last + 1] = (char) currentChar;
                last++;
                block[last + 1] = (char) (runLength - 4);
                break;
            }
        } else {
            endBlock();
            initBlock();
            writeRun();
        }
    }

    boolean closed = false;

    protected void finalize() throws Throwable {
        close();
        super.finalize();
    }

    public void close() throws IOException {
        if (closed) {
            return;
        }

        if (runLength > 0) {
            writeRun();
        }
        currentChar = -1;
        endBlock();
        endCompression();
        closed = true;
        super.close();
        bsStream.close();
    }

    public void flush() throws IOException {
        super.flush();
        bsStream.flush();
    }

    private int blockCRC, combinedCRC;

    private void initialize() throws IOException {
        bytesOut = 0;
        nBlocksRandomised = 0;

        /* Write `magic' bytes h indicating file-format == huffmanised,
           followed by a digit indicating blockSize100k.
        */