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.hadoop.conf.Configurable;
026 import org.apache.hadoop.conf.Configuration;
027 import org.apache.hadoop.io.compress.lz4.Lz4Compressor;
028 import org.apache.hadoop.io.compress.lz4.Lz4Decompressor;
029 import org.apache.hadoop.fs.CommonConfigurationKeys;
030 import org.apache.hadoop.util.NativeCodeLoader;
031
032 /**
033 * This class creates lz4 compressors/decompressors.
034 */
035 public class Lz4Codec implements Configurable, CompressionCodec {
036
037 static {
038 NativeCodeLoader.isNativeCodeLoaded();
039 }
040
041 Configuration conf;
042
043 /**
044 * Set the configuration to be used by this object.
045 *
046 * @param conf the configuration object.
047 */
048 @Override
049 public void setConf(Configuration conf) {
050 this.conf = conf;
051 }
052
053 /**
054 * Return the configuration used by this object.
055 *
056 * @return the configuration object used by this objec.
057 */
058 @Override
059 public Configuration getConf() {
060 return conf;
061 }
062
063 /**
064 * Are the native lz4 libraries loaded & initialized?
065 *
066 * @return true if loaded & initialized, otherwise false
067 */
068 public static boolean isNativeCodeLoaded() {
069 return NativeCodeLoader.isNativeCodeLoaded();
070 }
071
072 public static String getLibraryName() {
073 return Lz4Compressor.getLibraryName();
074 }
075
076 /**
077 * Create a {@link CompressionOutputStream} that will write to the given
078 * {@link OutputStream}.
079 *
080 * @param out the location for the final output stream
081 * @return a stream the user can write uncompressed data to have it compressed
082 * @throws IOException
083 */
084 @Override
085 public CompressionOutputStream createOutputStream(OutputStream out)
086 throws IOException {
087 return createOutputStream(out, createCompressor());
088 }
089
090 /**
091 * Create a {@link CompressionOutputStream} that will write to the given
092 * {@link OutputStream} with the given {@link Compressor}.
093 *
094 * @param out the location for the final output stream
095 * @param compressor compressor to use
096 * @return a stream the user can write uncompressed data to have it compressed
097 * @throws IOException
098 */
099 @Override
100 public CompressionOutputStream createOutputStream(OutputStream out,
101 Compressor compressor)
102 throws IOException {
103 if (!isNativeCodeLoaded()) {
104 throw new RuntimeException("native lz4 library not available");
105 }
106 int bufferSize = conf.getInt(
107 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_KEY,
108 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_DEFAULT);
109
110 int compressionOverhead = bufferSize/255 + 16;
111
112 return new BlockCompressorStream(out, compressor, bufferSize,
113 compressionOverhead);
114 }
115
116 /**
117 * Get the type of {@link Compressor} needed by this {@link CompressionCodec}.
118 *
119 * @return the type of compressor needed by this codec.
120 */
121 @Override
122 public Class<? extends Compressor> getCompressorType() {
123 if (!isNativeCodeLoaded()) {
124 throw new RuntimeException("native lz4 library not available");
125 }
126
127 return Lz4Compressor.class;
128 }
129
130 /**
131 * Create a new {@link Compressor} for use by this {@link CompressionCodec}.
132 *
133 * @return a new compressor for use by this codec
134 */
135 @Override
136 public Compressor createCompressor() {
137 if (!isNativeCodeLoaded()) {
138 throw new RuntimeException("native lz4 library not available");
139 }
140 int bufferSize = conf.getInt(
141 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_KEY,
142 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_DEFAULT);
143 boolean useLz4HC = conf.getBoolean(
144 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_USELZ4HC_KEY,
145 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_USELZ4HC_DEFAULT);
146 return new Lz4Compressor(bufferSize, useLz4HC);
147 }
148
149 /**
150 * Create a {@link CompressionInputStream} that will read from the given
151 * input stream.
152 *
153 * @param in the stream to read compressed bytes from
154 * @return a stream to read uncompressed bytes from
155 * @throws IOException
156 */
157 @Override
158 public CompressionInputStream createInputStream(InputStream in)
159 throws IOException {
160 return createInputStream(in, createDecompressor());
161 }
162
163 /**
164 * Create a {@link CompressionInputStream} that will read from the given
165 * {@link InputStream} with the given {@link Decompressor}.
166 *
167 * @param in the stream to read compressed bytes from
168 * @param decompressor decompressor to use
169 * @return a stream to read uncompressed bytes from
170 * @throws IOException
171 */
172 @Override
173 public CompressionInputStream createInputStream(InputStream in,
174 Decompressor decompressor)
175 throws IOException {
176 if (!isNativeCodeLoaded()) {
177 throw new RuntimeException("native lz4 library not available");
178 }
179
180 return new BlockDecompressorStream(in, decompressor, conf.getInt(
181 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_KEY,
182 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_DEFAULT));
183 }
184
185 /**
186 * Get the type of {@link Decompressor} needed by this {@link CompressionCodec}.
187 *
188 * @return the type of decompressor needed by this codec.
189 */
190 @Override
191 public Class<? extends Decompressor> getDecompressorType() {
192 if (!isNativeCodeLoaded()) {
193 throw new RuntimeException("native lz4 library not available");
194 }
195
196 return Lz4Decompressor.class;
197 }
198
199 /**
200 * Create a new {@link Decompressor} for use by this {@link CompressionCodec}.
201 *
202 * @return a new decompressor for use by this codec
203 */
204 @Override
205 public Decompressor createDecompressor() {
206 if (!isNativeCodeLoaded()) {
207 throw new RuntimeException("native lz4 library not available");
208 }
209 int bufferSize = conf.getInt(
210 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_KEY,
211 CommonConfigurationKeys.IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_DEFAULT);
212 return new Lz4Decompressor(bufferSize);
213 }
214
215 /**
216 * Get the default filename extension for this kind of compression.
217 *
218 * @return <code>.lz4</code>.
219 */
220 @Override
221 public String getDefaultExtension() {
222 return ".lz4";
223 }
224 }