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    
019    package org.apache.hadoop.io.compress;
020    
021    import java.io.IOException;
022    import java.io.InputStream;
023    import java.io.OutputStream;
024    
025    import org.apache.commons.logging.Log;
026    import org.apache.commons.logging.LogFactory;
027    import org.apache.hadoop.classification.InterfaceAudience;
028    import org.apache.hadoop.classification.InterfaceStability;
029    import org.apache.hadoop.conf.Configurable;
030    import org.apache.hadoop.conf.Configuration;
031    import org.apache.hadoop.io.compress.zlib.ZlibDecompressor;
032    import org.apache.hadoop.io.compress.zlib.ZlibFactory;
033    
034    @InterfaceAudience.Public
035    @InterfaceStability.Evolving
036    public 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    }