# Source code

    001/*
    002 *  Licensed to the Apache Software Foundation (ASF) under one or more
    003 *  contributor license agreements.  See the NOTICE file distributed with
    004 *  this work for additional information regarding copyright ownership.
    005 *  The ASF licenses this file to You under the Apache License, Version 2.0
    006 *  (the "License"); you may not use this file except in compliance with
    007 *  the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 *
    017 */
    018package org.apache.commons.compress.archivers.zip;
    019
    020import org.apache.commons.compress.parallel.ScatterGatherBackingStore;
    021
    022import java.io.Closeable;
    023import java.io.DataOutput;
    024import java.io.IOException;
    025import java.io.InputStream;
    026import java.io.OutputStream;
    027import java.nio.ByteBuffer;
    028import java.nio.channels.SeekableByteChannel;
    029import java.util.zip.CRC32;
    030import java.util.zip.Deflater;
    031import java.util.zip.ZipEntry;
    032
    033/**
    034 * Encapsulates a {@link Deflater} and crc calculator, handling multiple types of output streams.
    035 * Currently {@link java.util.zip.ZipEntry#DEFLATED} and {@link java.util.zip.ZipEntry#STORED} are the only
    036 * supported compression methods.
    037 *
    038 * @since 1.10
    039 */
    040public abstract class StreamCompressor implements Closeable {
    041
    042    /*
    043     * Apparently Deflater.setInput gets slowed down a lot on Sun JVMs
    044     * when it gets handed a really big buffer.  See
    045     * https://issues.apache.org/bugzilla/show_bug.cgi?id=45396
    046     *
    047     * Using a buffer size of 8 kB proved to be a good compromise
    048     */
    049    private static final int DEFLATER_BLOCK_SIZE = 8192;
    050
    051    private final Deflater def;
    052
    053    private final CRC32 crc = new CRC32();
    054
    055    private long writtenToOutputStreamForLastEntry = 0;
    056    private long sourcePayloadLength = 0;
    057    private long totalWrittenToOutputStream = 0;
    058
    059    private static final int BUFFER_SIZE = 4096;
    060    private final byte[] outputBuffer = new byte[BUFFER_SIZE];
    061    private final byte[] readerBuf = new byte[BUFFER_SIZE];
    062
    063    StreamCompressor(final Deflater deflater) {
    064        this.def = deflater;
    065    }
    066
    067    /**
    068     * Create a stream compressor with the given compression level.
    069     *
    070     * @param os       The stream to receive output
    071     * @param deflater The deflater to use
    072     * @return A stream compressor
    073     */
    074    static StreamCompressor create(final OutputStream os, final Deflater deflater) {
    075        return new OutputStreamCompressor(deflater, os);
    076    }
    077
    078    /**
    079     * Create a stream compressor with the default compression level.
    080     *
    081     * @param os The stream to receive output
    082     * @return A stream compressor
    083     */
    084    static StreamCompressor create(final OutputStream os) {
    085        return create(os, new Deflater(Deflater.DEFAULT_COMPRESSION, true));
    086    }
    087
    088    /**
    089     * Create a stream compressor with the given compression level.
    090     *
    091     * @param os       The DataOutput to receive output
    092     * @param deflater The deflater to use for the compressor
    093     * @return A stream compressor
    094     */
    095    static StreamCompressor create(final DataOutput os, final Deflater deflater) {
    096        return new DataOutputCompressor(deflater, os);
    097    }
    098
    099    /**
    100     * Create a stream compressor with the given compression level.
    101     *
    102     * @param os       The SeekableByteChannel to receive output
    103     * @param deflater The deflater to use for the compressor
    104     * @return A stream compressor
    105     * @since 1.13
    106     */
    107    static StreamCompressor create(final SeekableByteChannel os, final Deflater deflater) {
    108        return new SeekableByteChannelCompressor(deflater, os);
    109    }
    110
    111    /**
    112     * Create a stream compressor with the given compression level.
    113     *
    114     * @param compressionLevel The {@link Deflater}  compression level
    115     * @param bs               The ScatterGatherBackingStore to receive output
    116     * @return A stream compressor
    117     */
    118    public static StreamCompressor create(final int compressionLevel, final ScatterGatherBackingStore bs) {
    119        final Deflater deflater = new Deflater(compressionLevel, true);
    120        return new ScatterGatherBackingStoreCompressor(deflater, bs);
    121    }
    122
    123    /**
    124     * Create a stream compressor with the default compression level.
    125     *
    126     * @param bs The ScatterGatherBackingStore to receive output
    127     * @return A stream compressor
    128     */
    129    public static StreamCompressor create(final ScatterGatherBackingStore bs) {
    130        return create(Deflater.DEFAULT_COMPRESSION, bs);
    131    }
    132
    133    /**
    134     * The crc32 of the last deflated file
    135     *
    136     * @return the crc32
    137     */
    138
    139    public long getCrc32() {
    140        return crc.getValue();
    141    }
    142
    143    /**
    144     * Return the number of bytes read from the source stream
    145     *
    146     * @return The number of bytes read, never negative
    147     */
    148    public long getBytesRead() {
    149        return sourcePayloadLength;
    150    }
    151
    152    /**
    153     * The number of bytes written to the output for the last entry
    154     *
    155     * @return The number of bytes, never negative
    156     */
    157    public long getBytesWrittenForLastEntry() {
    158        return writtenToOutputStreamForLastEntry;
    159    }
    160
    161    /**
    162     * The total number of bytes written to the output for all files
    163     *
    164     * @return The number of bytes, never negative
    165     */
    166    public long getTotalBytesWritten() {
    167        return totalWrittenToOutputStream;
    168    }
    169
    170
    171    /**
    172     * Deflate the given source using the supplied compression method
    173     *
    174     * @param source The source to compress
    175     * @param method The #ZipArchiveEntry compression method
    176     * @throws IOException When failures happen
    177     */
    178
    179    public void deflate(final InputStream source, final int method) throws IOException {
    180        reset();
    181        int length;
    182
    183        while ((length = source.read(readerBuf, 0, readerBuf.length)) >= 0) {
    184            write(readerBuf, 0, length, method);
    185        }
    186        if (method == ZipEntry.DEFLATED) {
    187            flushDeflater();
    188        }
    189    }
    190
    191    /**
    192     * Writes bytes to ZIP entry.
    193     *
    194     * @param b      the byte array to write
    195     * @param offset the start position to write from
    196     * @param length the number of bytes to write
    197     * @param method the comrpession method to use
    198     * @return the number of bytes written to the stream this time
    199     * @throws IOException on error
    200     */
    201    long write(final byte[] b, final int offset, final int length, final int method) throws IOException {
    202        final long current = writtenToOutputStreamForLastEntry;
    203        crc.update(b, offset, length);
    204        if (method == ZipEntry.DEFLATED) {
    205            writeDeflated(b, offset, length);
    206        } else {
    207            writeCounted(b, offset, length);
    208        }
    209        sourcePayloadLength += length;
    210        return writtenToOutputStreamForLastEntry - current;
    211    }
    212
    213
    214    void reset() {
    215        crc.reset();
    216        def.reset();
    217        sourcePayloadLength = 0;
    218        writtenToOutputStreamForLastEntry = 0;
    219    }
    220
    221    @Override
    222    public void close() throws IOException {
    223        def.end();
    224    }
    225
    226    void flushDeflater() throws IOException {
    227        def.finish();
    228        while (!def.finished()) {
    229            deflate();
    230        }
    231    }
    232
    233    private void writeDeflated(final byte[] b, final int offset, final int length)
    234            throws IOException {
    235        if (length > 0 && !def.finished()) {
    236            if (length <= DEFLATER_BLOCK_SIZE) {
    237                def.setInput(b, offset, length);
    238                deflateUntilInputIsNeeded();
    239            } else {
    240                final int fullblocks = length / DEFLATER_BLOCK_SIZE;
    241                for (int i = 0; i < fullblocks; i++) {
    242                    def.setInput(b, offset + i * DEFLATER_BLOCK_SIZE,
    243                            DEFLATER_BLOCK_SIZE);
    244                    deflateUntilInputIsNeeded();
    245                }
    246                final int done = fullblocks * DEFLATER_BLOCK_SIZE;
    247                if (done < length) {
    248                    def.setInput(b, offset + done, length - done);
    249                    deflateUntilInputIsNeeded();
    250                }
    251            }
    252        }
    253    }
    254
    255    private void deflateUntilInputIsNeeded() throws IOException {
    256        while (!def.needsInput()) {
    257            deflate();
    258        }
    259    }
    260
    261    void deflate() throws IOException {
    262        final int len = def.deflate(outputBuffer, 0, outputBuffer.length);
    263        if (len > 0) {
    264            writeCounted(outputBuffer, 0, len);
    265        }
    266    }
    267
    268    public void writeCounted(final byte[] data) throws IOException {
    269        writeCounted(data, 0, data.length);
    270    }
    271
    272    public void writeCounted(final byte[] data, final int offset, final int length) throws IOException {
    273        writeOut(data, offset, length);
    274        writtenToOutputStreamForLastEntry += length;
    275        totalWrittenToOutputStream += length;
    276    }
    277
    278    protected abstract void writeOut(byte[] data, int offset, int length) throws IOException;
    279
    280    private static final class ScatterGatherBackingStoreCompressor extends StreamCompressor {
    281        private final ScatterGatherBackingStore bs;
    282
    283        public ScatterGatherBackingStoreCompressor(final Deflater deflater, final ScatterGatherBackingStore bs) {
    284            super(deflater);
    285            this.bs = bs;
    286        }
    287
    288        @Override
    289        protected final void writeOut(final byte[] data, final int offset, final int length)
    290                throws IOException {
    291            bs.writeOut(data, offset, length);
    292        }
    293    }
    294
    295    private static final class OutputStreamCompressor extends StreamCompressor {
    296        private final OutputStream os;
    297
    298        public OutputStreamCompressor(final Deflater deflater, final OutputStream os) {
    299            super(deflater);
    300            this.os = os;
    301        }
    302
    303        @Override
    304        protected final void writeOut(final byte[] data, final int offset, final int length)
    305                throws IOException {
    306            os.write(data, offset, length);
    307        }
    308    }
    309
    310    private static final class DataOutputCompressor extends StreamCompressor {
    311        private final DataOutput raf;
    312
    313        public DataOutputCompressor(final Deflater deflater, final DataOutput raf) {
    314            super(deflater);
    315            this.raf = raf;
    316        }
    317
    318        @Override
    319        protected final void writeOut(final byte[] data, final int offset, final int length)
    320                throws IOException {
    321            raf.write(data, offset, length);
    322        }
    323    }
    324
    325    private static final class SeekableByteChannelCompressor extends StreamCompressor {
    326        private final SeekableByteChannel channel;
    327
    328        public SeekableByteChannelCompressor(final Deflater deflater,
    329                                             final SeekableByteChannel channel) {
    330            super(deflater);
    331            this.channel = channel;
    332        }
    333
    334        @Override
    335        protected final void writeOut(final byte[] data, final int offset, final int length)
    336                throws IOException {
    337            channel.write(ByteBuffer.wrap(data, offset, length));
    338        }
    339    }
    340}