/*
* 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.howl.rcfile;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.ql.io.RCFile;
import org.apache.hadoop.hive.serde2.columnar.BytesRefArrayWritable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.DefaultCodec;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.ReflectionUtils;
/**
* The RC file input format using new Hadoop mapreduce APIs.
*/
public class RCFileMapReduceOutputFormat extends
FileOutputFormat<WritableComparable<?>, BytesRefArrayWritable> {
/**
* Set number of columns into the given configuration.
* @param conf
* configuration instance which need to set the column number
* @param columnNum
* column number for RCFile's Writer
*
*/
public static void setColumnNumber(Configuration conf, int columnNum) {
assert columnNum > 0;
conf.setInt(RCFile.COLUMN_NUMBER_CONF_STR, columnNum);
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.lib.output.FileOutputFormat#getRecordWriter(org.apache.hadoop.mapreduce.TaskAttemptContext)
*/
@Override
public org.apache.hadoop.mapreduce.RecordWriter<WritableComparable<?>, BytesRefArrayWritable> getRecordWriter(
TaskAttemptContext task) throws IOException, InterruptedException {
//FileOutputFormat.getWorkOutputPath takes TaskInputOutputContext instead of
//TaskAttemptContext, so can't use that here
FileOutputCommitter committer = (FileOutputCommitter) getOutputCommitter(task);
Path outputPath = committer.getWorkPath();
FileSystem fs = outputPath.getFileSystem(task.getConfiguration());
if (!fs.exists(outputPath)) {
fs.mkdirs(outputPath);
}
Path file = getDefaultWorkFile(task, "");
CompressionCodec codec = null;
if (getCompressOutput(task)) {
Class<?> codecClass = getOutputCompressorClass(task, DefaultCodec.class);
codec = (CompressionCodec) ReflectionUtils.newInstance(codecClass, task.getConfiguration());
}
final RCFile.Writer out = new RCFile.Writer(fs, task.getConfiguration(), file, task, codec);
return new RecordWriter<WritableComparable<?>, BytesRefArrayWritable>() {
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.RecordWriter#write(java.lang.Object, java.lang.Object)
*/
@Override
public void write(WritableComparable<?> key, BytesRefArrayWritable value)
throws IOException {
out.append(value);
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.RecordWriter#close(org.apache.hadoop.mapreduce.TaskAttemptContext)
*/
@Override
public void close(TaskAttemptContext task) throws IOException, InterruptedException {
out.close();
}
};
}
}