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.*;
022 import java.util.zip.GZIPOutputStream;
023 import java.util.zip.GZIPInputStream;
024
025 import org.apache.hadoop.classification.InterfaceAudience;
026 import org.apache.hadoop.classification.InterfaceStability;
027 import org.apache.hadoop.conf.Configuration;
028 import org.apache.hadoop.io.compress.DefaultCodec;
029 import org.apache.hadoop.io.compress.zlib.*;
030 import org.apache.hadoop.io.compress.zlib.ZlibCompressor.CompressionLevel;
031 import org.apache.hadoop.io.compress.zlib.ZlibCompressor.CompressionStrategy;
032
033 /**
034 * This class creates gzip compressors/decompressors.
035 */
036 @InterfaceAudience.Public
037 @InterfaceStability.Evolving
038 public class GzipCodec extends DefaultCodec {
039 /**
040 * A bridge that wraps around a DeflaterOutputStream to make it
041 * a CompressionOutputStream.
042 */
043 @InterfaceStability.Evolving
044 protected static class GzipOutputStream extends CompressorStream {
045
046 private static class ResetableGZIPOutputStream extends GZIPOutputStream {
047
048 public ResetableGZIPOutputStream(OutputStream out) throws IOException {
049 super(out);
050 }
051
052 public void resetState() throws IOException {
053 def.reset();
054 }
055 }
056
057 public GzipOutputStream(OutputStream out) throws IOException {
058 super(new ResetableGZIPOutputStream(out));
059 }
060
061 /**
062 * Allow children types to put a different type in here.
063 * @param out the Deflater stream to use
064 */
065 protected GzipOutputStream(CompressorStream out) {
066 super(out);
067 }
068
069 public void close() throws IOException {
070 out.close();
071 }
072
073 public void flush() throws IOException {
074 out.flush();
075 }
076
077 public void write(int b) throws IOException {
078 out.write(b);
079 }
080
081 public void write(byte[] data, int offset, int length)
082 throws IOException {
083 out.write(data, offset, length);
084 }
085
086 public void finish() throws IOException {
087 ((ResetableGZIPOutputStream) out).finish();
088 }
089
090 public void resetState() throws IOException {
091 ((ResetableGZIPOutputStream) out).resetState();
092 }
093 }
094
095 public CompressionOutputStream createOutputStream(OutputStream out)
096 throws IOException {
097 return (ZlibFactory.isNativeZlibLoaded(conf)) ?
098 new CompressorStream(out, createCompressor(),
099 conf.getInt("io.file.buffer.size", 4*1024)) :
100 new GzipOutputStream(out);
101 }
102
103 public CompressionOutputStream createOutputStream(OutputStream out,
104 Compressor compressor)
105 throws IOException {
106 return (compressor != null) ?
107 new CompressorStream(out, compressor,
108 conf.getInt("io.file.buffer.size",
109 4*1024)) :
110 createOutputStream(out);
111 }
112
113 public Compressor createCompressor() {
114 return (ZlibFactory.isNativeZlibLoaded(conf))
115 ? new GzipZlibCompressor(conf)
116 : null;
117 }
118
119 public Class<? extends Compressor> getCompressorType() {
120 return ZlibFactory.isNativeZlibLoaded(conf)
121 ? GzipZlibCompressor.class
122 : null;
123 }
124
125 public CompressionInputStream createInputStream(InputStream in)
126 throws IOException {
127 return createInputStream(in, null);
128 }
129
130 public CompressionInputStream createInputStream(InputStream in,
131 Decompressor decompressor)
132 throws IOException {
133 if (decompressor == null) {
134 decompressor = createDecompressor(); // always succeeds (or throws)
135 }
136 return new DecompressorStream(in, decompressor,
137 conf.getInt("io.file.buffer.size", 4*1024));
138 }
139
140 public Decompressor createDecompressor() {
141 return (ZlibFactory.isNativeZlibLoaded(conf))
142 ? new GzipZlibDecompressor()
143 : new BuiltInGzipDecompressor();
144 }
145
146 public Class<? extends Decompressor> getDecompressorType() {
147 return ZlibFactory.isNativeZlibLoaded(conf)
148 ? GzipZlibDecompressor.class
149 : BuiltInGzipDecompressor.class;
150 }
151
152 public String getDefaultExtension() {
153 return ".gz";
154 }
155
156 static final class GzipZlibCompressor extends ZlibCompressor {
157 public GzipZlibCompressor() {
158 super(ZlibCompressor.CompressionLevel.DEFAULT_COMPRESSION,
159 ZlibCompressor.CompressionStrategy.DEFAULT_STRATEGY,
160 ZlibCompressor.CompressionHeader.GZIP_FORMAT, 64*1024);
161 }
162
163 public GzipZlibCompressor(Configuration conf) {
164 super(ZlibFactory.getCompressionLevel(conf),
165 ZlibFactory.getCompressionStrategy(conf),
166 ZlibCompressor.CompressionHeader.GZIP_FORMAT,
167 64 * 1024);
168 }
169 }
170
171 static final class GzipZlibDecompressor extends ZlibDecompressor {
172 public GzipZlibDecompressor() {
173 super(ZlibDecompressor.CompressionHeader.AUTODETECT_GZIP_ZLIB, 64*1024);
174 }
175 }
176
177 }