001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.commons.compress.compressors.xz;
020
021import java.io.IOException;
022import java.io.OutputStream;
023
024import org.apache.commons.compress.compressors.CompressorOutputStream;
025import org.tukaani.xz.LZMA2Options;
026import org.tukaani.xz.XZOutputStream;
027
028/**
029 * XZ compressor.
030 *
031 * @since 1.4
032 */
033public class XZCompressorOutputStream extends CompressorOutputStream {
034    private final XZOutputStream out;
035
036    /**
037     * Creates a new XZ compressor using the default LZMA2 options. This is equivalent to {@code XZCompressorOutputStream(outputStream, 6)}.
038     *
039     * @param outputStream the stream to wrap
040     * @throws IOException on error
041     */
042    public XZCompressorOutputStream(final OutputStream outputStream) throws IOException {
043        out = new XZOutputStream(outputStream, new LZMA2Options());
044    }
045
046    /**
047     * Creates a new XZ compressor using the specified LZMA2 preset level.
048     * <p>
049     * The presets 0-3 are fast presets with medium compression. The presets 4-6 are fairly slow presets with high compression. The default preset is 6.
050     * <p>
051     * The presets 7-9 are like the preset 6 but use bigger dictionaries and have higher compressor and decompressor memory requirements. Unless the
052     * uncompressed size of the file exceeds 8&nbsp;MiB, 16&nbsp;MiB, or 32&nbsp;MiB, it is waste of memory to use the presets 7, 8, or 9, respectively.
053     *
054     * @param outputStream the stream to wrap
055     * @param preset       the preset
056     * @throws IOException on error
057     */
058    public XZCompressorOutputStream(final OutputStream outputStream, final int preset) throws IOException {
059        out = new XZOutputStream(outputStream, new LZMA2Options(preset));
060    }
061
062    @Override
063    public void close() throws IOException {
064        out.close();
065    }
066
067    /**
068     * Finishes compression without closing the underlying stream. No more data can be written to this stream after finishing.
069     *
070     * @throws IOException on error
071     */
072    public void finish() throws IOException {
073        out.finish();
074    }
075
076    /**
077     * Flushes the encoder and calls {@code outputStream.flush()}. All buffered pending data will then be decompressible from the output stream. Calling this
078     * function very often may increase the compressed file size a lot.
079     */
080    @Override
081    public void flush() throws IOException {
082        out.flush();
083    }
084
085    @Override
086    public void write(final byte[] buf, final int off, final int len) throws IOException {
087        out.write(buf, off, len);
088    }
089
090    @Override
091    public void write(final int b) throws IOException {
092        out.write(b);
093    }
094}