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 */
019 package org.apache.commons.compress.compressors.xz;
020
021 import java.io.IOException;
022 import java.io.OutputStream;
023 import org.tukaani.xz.LZMA2Options;
024 import org.tukaani.xz.XZOutputStream;
025
026 import org.apache.commons.compress.compressors.CompressorOutputStream;
027
028 /**
029 * XZ compressor.
030 * @since Commons Compress 1.4
031 */
032 public class XZCompressorOutputStream extends CompressorOutputStream {
033 private final XZOutputStream out;
034
035 /**
036 * Creates a new XZ compressor using the default LZMA2 options.
037 * This is equivalent to <code>XZCompressorOutputStream(6)</code>.
038 */
039 public XZCompressorOutputStream(OutputStream outputStream)
040 throws IOException {
041 out = new XZOutputStream(outputStream, new LZMA2Options());
042 }
043
044 /**
045 * Creates a new XZ compressor using the specified LZMA2 preset level.
046 * <p>
047 * The presets 0-3 are fast presets with medium compression.
048 * The presets 4-6 are fairly slow presets with high compression.
049 * The default preset is 6.
050 * <p>
051 * The presets 7-9 are like the preset 6 but use bigger dictionaries
052 * and have higher compressor and decompressor memory requirements.
053 * Unless the uncompressed size of the file exceeds 8 MiB,
054 * 16 MiB, or 32 MiB, it is waste of memory to use the
055 * presets 7, 8, or 9, respectively.
056 */
057 public XZCompressorOutputStream(OutputStream outputStream, int preset)
058 throws IOException {
059 out = new XZOutputStream(outputStream, new LZMA2Options(preset));
060 }
061
062 /** {@inheritDoc} */
063 @Override
064 public void write(int b) throws IOException {
065 out.write(b);
066 }
067
068 /** {@inheritDoc} */
069 @Override
070 public void write(byte[] buf, int off, int len) throws IOException {
071 out.write(buf, off, len);
072 }
073
074 /**
075 * Flushes the encoder and calls <code>outputStream.flush()</code>.
076 * All buffered pending data will then be decompressible from
077 * the output stream. Calling this function very often may increase
078 * the compressed file size a lot.
079 */
080 @Override
081 public void flush() throws IOException {
082 out.flush();
083 }
084
085 /**
086 * Finishes compression without closing the underlying stream.
087 * No more data can be written to this stream after finishing.
088 */
089 public void finish() throws IOException {
090 out.finish();
091 }
092
093 /** {@inheritDoc} */
094 @Override
095 public void close() throws IOException {
096 out.close();
097 }
098 }