| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.hadoop.mapreduce.lib.output; |
| |
| import java.io.IOException; |
| |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| |
| import org.apache.hadoop.io.SequenceFile; |
| import org.apache.hadoop.io.SequenceFile.CompressionType; |
| import org.apache.hadoop.io.compress.CompressionCodec; |
| import org.apache.hadoop.io.compress.DefaultCodec; |
| import org.apache.hadoop.mapreduce.Job; |
| import org.apache.hadoop.mapreduce.JobContext; |
| import org.apache.hadoop.mapreduce.OutputFormat; |
| import org.apache.hadoop.mapreduce.RecordWriter; |
| import org.apache.hadoop.mapreduce.TaskAttemptContext; |
| import org.apache.hadoop.util.ReflectionUtils; |
| import org.apache.hadoop.conf.Configuration; |
| |
| /** An {@link OutputFormat} that writes {@link SequenceFile}s. */ |
| public class SequenceFileOutputFormat <K,V> extends FileOutputFormat<K, V> { |
| |
| protected SequenceFile.Writer getSequenceWriter(TaskAttemptContext context, |
| Class<?> keyClass, Class<?> valueClass) |
| throws IOException { |
| Configuration conf = context.getConfiguration(); |
| |
| CompressionCodec codec = null; |
| CompressionType compressionType = CompressionType.NONE; |
| if (getCompressOutput(context)) { |
| // find the kind of compression to do |
| compressionType = getOutputCompressionType(context); |
| // find the right codec |
| Class<?> codecClass = getOutputCompressorClass(context, |
| DefaultCodec.class); |
| codec = (CompressionCodec) |
| ReflectionUtils.newInstance(codecClass, conf); |
| } |
| // get the path of the temporary output file |
| Path file = getDefaultWorkFile(context, ""); |
| FileSystem fs = file.getFileSystem(conf); |
| return SequenceFile.createWriter(fs, conf, file, |
| keyClass, |
| valueClass, |
| compressionType, |
| codec, |
| context); |
| } |
| |
| public RecordWriter<K, V> |
| getRecordWriter(TaskAttemptContext context |
| ) throws IOException, InterruptedException { |
| final SequenceFile.Writer out = getSequenceWriter(context, |
| context.getOutputKeyClass(), context.getOutputValueClass()); |
| |
| return new RecordWriter<K, V>() { |
| |
| public void write(K key, V value) |
| throws IOException { |
| |
| out.append(key, value); |
| } |
| |
| public void close(TaskAttemptContext context) throws IOException { |
| out.close(); |
| } |
| }; |
| } |
| |
| /** |
| * Get the {@link CompressionType} for the output {@link SequenceFile}. |
| * @param job the {@link Job} |
| * @return the {@link CompressionType} for the output {@link SequenceFile}, |
| * defaulting to {@link CompressionType#RECORD} |
| */ |
| public static CompressionType getOutputCompressionType(JobContext job) { |
| String val = job.getConfiguration().get(FileOutputFormat.COMPRESS_TYPE, |
| CompressionType.RECORD.toString()); |
| return CompressionType.valueOf(val); |
| } |
| |
| /** |
| * Set the {@link CompressionType} for the output {@link SequenceFile}. |
| * @param job the {@link Job} to modify |
| * @param style the {@link CompressionType} for the output |
| * {@link SequenceFile} |
| */ |
| public static void setOutputCompressionType(Job job, |
| CompressionType style) { |
| setCompressOutput(job, true); |
| job.getConfiguration().set(FileOutputFormat.COMPRESS_TYPE, |
| style.toString()); |
| } |
| |
| } |
| |