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/**
* 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.mapred;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.LocalDirAllocator;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.MRConfig;
import org.apache.hadoop.mapreduce.MRJobConfig;
/**
* Manipulate the working area for the transient store for maps and reduces.
*
* This class is used by map and reduce tasks to identify the directories that
* they need to write to/read from for intermediate files. The callers of
* these methods are from the Child running the Task.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
public class MROutputFiles extends MapOutputFile {
private LocalDirAllocator lDirAlloc =
new LocalDirAllocator(MRConfig.LOCAL_DIR);
public MROutputFiles() {
}
/**
* Return the path to local map output file created earlier
*
* @return path
* @throws IOException
*/
@Override
public Path getOutputFile()
throws IOException {
return lDirAlloc.getLocalPathToRead(MRJobConfig.OUTPUT + Path.SEPARATOR
+ MAP_OUTPUT_FILENAME_STRING, getConf());
}
/**
* Create a local map output file name.
*
* @param size the size of the file
* @return path
* @throws IOException
*/
@Override
public Path getOutputFileForWrite(long size)
throws IOException {
return lDirAlloc.getLocalPathForWrite(MRJobConfig.OUTPUT + Path.SEPARATOR
+ MAP_OUTPUT_FILENAME_STRING, size, getConf());
}
/**
* Create a local map output file name on the same volume.
*/
@Override
public Path getOutputFileForWriteInVolume(Path existing) {
return new Path(existing.getParent(), MAP_OUTPUT_FILENAME_STRING);
}
/**
* Return the path to a local map output index file created earlier
*
* @return path
* @throws IOException
*/
@Override
public Path getOutputIndexFile()
throws IOException {
return lDirAlloc.getLocalPathToRead(MRJobConfig.OUTPUT + Path.SEPARATOR
+ MAP_OUTPUT_FILENAME_STRING + MAP_OUTPUT_INDEX_SUFFIX_STRING,
getConf());
}
/**
* Create a local map output index file name.
*
* @param size the size of the file
* @return path
* @throws IOException
*/
@Override
public Path getOutputIndexFileForWrite(long size)
throws IOException {
return lDirAlloc.getLocalPathForWrite(MRJobConfig.OUTPUT + Path.SEPARATOR
+ MAP_OUTPUT_FILENAME_STRING + MAP_OUTPUT_INDEX_SUFFIX_STRING,
size, getConf());
}
/**
* Create a local map output index file name on the same volume.
*/
@Override
public Path getOutputIndexFileForWriteInVolume(Path existing) {
return new Path(existing.getParent(),
MAP_OUTPUT_FILENAME_STRING + MAP_OUTPUT_INDEX_SUFFIX_STRING);
}
/**
* Return a local map spill file created earlier.
*
* @param spillNumber the number
* @return path
* @throws IOException
*/
@Override
public Path getSpillFile(int spillNumber)
throws IOException {
return lDirAlloc.getLocalPathToRead(MRJobConfig.OUTPUT + "/spill"
+ spillNumber + ".out", getConf());
}
/**
* Create a local map spill file name.
*
* @param spillNumber the number
* @param size the size of the file
* @return path
* @throws IOException
*/
@Override
public Path getSpillFileForWrite(int spillNumber, long size)
throws IOException {
return lDirAlloc.getLocalPathForWrite(MRJobConfig.OUTPUT + "/spill"
+ spillNumber + ".out", size, getConf());
}
/**
* Return a local map spill index file created earlier
*
* @param spillNumber the number
* @return path
* @throws IOException
*/
@Override
public Path getSpillIndexFile(int spillNumber)
throws IOException {
return lDirAlloc.getLocalPathToRead(MRJobConfig.OUTPUT + "/spill"
+ spillNumber + ".out.index", getConf());
}
/**
* Create a local map spill index file name.
*
* @param spillNumber the number
* @param size the size of the file
* @return path
* @throws IOException
*/
@Override
public Path getSpillIndexFileForWrite(int spillNumber, long size)
throws IOException {
return lDirAlloc.getLocalPathForWrite(MRJobConfig.OUTPUT + "/spill"
+ spillNumber + ".out.index", size, getConf());
}
/**
* Return a local reduce input file created earlier
*
* @param mapId a map task id
* @return path
* @throws IOException
*/
@Override
public Path getInputFile(int mapId)
throws IOException {
return lDirAlloc.getLocalPathToRead(String.format(
REDUCE_INPUT_FILE_FORMAT_STRING, MRJobConfig.OUTPUT, Integer
.valueOf(mapId)), getConf());
}
/**
* Create a local reduce input file name.
*
* @param mapId a map task id
* @param size the size of the file
* @return path
* @throws IOException
*/
@Override
public Path getInputFileForWrite(org.apache.hadoop.mapreduce.TaskID mapId,
long size)
throws IOException {
return lDirAlloc.getLocalPathForWrite(String.format(
REDUCE_INPUT_FILE_FORMAT_STRING, MRJobConfig.OUTPUT, mapId.getId()),
size, getConf());
}
/** Removes all of the files related to a task. */
@Override
public void removeAll()
throws IOException {
((JobConf)getConf()).deleteLocalFiles(MRJobConfig.OUTPUT);
}
@Override
public void setConf(Configuration conf) {
if (!(conf instanceof JobConf)) {
conf = new JobConf(conf);
}
super.setConf(conf);
}
}