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, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.io.compress;
020
021import java.io.IOException;
022import java.io.InputStream;
023import java.io.OutputStream;
024
025import org.apache.commons.logging.Log;
026import org.apache.commons.logging.LogFactory;
027import org.apache.hadoop.classification.InterfaceAudience;
028import org.apache.hadoop.classification.InterfaceStability;
029import org.apache.hadoop.conf.Configurable;
030import org.apache.hadoop.conf.Configuration;
031import org.apache.hadoop.io.compress.zlib.ZlibDecompressor;
032import org.apache.hadoop.io.compress.zlib.ZlibFactory;
033
034@InterfaceAudience.Public
035@InterfaceStability.Evolving
036public class DefaultCodec implements Configurable, CompressionCodec, DirectDecompressionCodec {
037  private static final Log LOG = LogFactory.getLog(DefaultCodec.class);
038  
039  Configuration conf;
040
041  @Override
042  public void setConf(Configuration conf) {
043    this.conf = conf;
044  }
045  
046  @Override
047  public Configuration getConf() {
048    return conf;
049  }
050  
051  @Override
052  public CompressionOutputStream createOutputStream(OutputStream out) 
053  throws IOException {
054    // This may leak memory if called in a loop. The createCompressor() call
055    // may cause allocation of an untracked direct-backed buffer if native
056    // libs are being used (even if you close the stream).  A Compressor
057    // object should be reused between successive calls.
058    LOG.warn("DefaultCodec.createOutputStream() may leak memory. "
059        + "Create a compressor first.");
060    return new CompressorStream(out, createCompressor(), 
061                                conf.getInt("io.file.buffer.size", 4*1024));
062  }
063
064  @Override
065  public CompressionOutputStream createOutputStream(OutputStream out, 
066                                                    Compressor compressor) 
067  throws IOException {
068    return new CompressorStream(out, compressor, 
069                                conf.getInt("io.file.buffer.size", 4*1024));
070  }
071
072  @Override
073  public Class<? extends Compressor> getCompressorType() {
074    return ZlibFactory.getZlibCompressorType(conf);
075  }
076
077  @Override
078  public Compressor createCompressor() {
079    return ZlibFactory.getZlibCompressor(conf);
080  }
081
082  @Override
083  public CompressionInputStream createInputStream(InputStream in) 
084  throws IOException {
085    return new DecompressorStream(in, createDecompressor(),
086                                  conf.getInt("io.file.buffer.size", 4*1024));
087  }
088
089  @Override
090  public CompressionInputStream createInputStream(InputStream in, 
091                                                  Decompressor decompressor) 
092  throws IOException {
093    return new DecompressorStream(in, decompressor, 
094                                  conf.getInt("io.file.buffer.size", 4*1024));
095  }
096
097  @Override
098  public Class<? extends Decompressor> getDecompressorType() {
099    return ZlibFactory.getZlibDecompressorType(conf);
100  }
101
102  @Override
103  public Decompressor createDecompressor() {
104    return ZlibFactory.getZlibDecompressor(conf);
105  }
106  
107  /**
108   * {@inheritDoc}
109   */
110  @Override
111  public DirectDecompressor createDirectDecompressor() {
112    return ZlibFactory.getZlibDirectDecompressor(conf);
113  }
114  
115  
116  @Override
117  public String getDefaultExtension() {
118    return ".deflate";
119  }
120
121}