| /** |
| * 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; |
| |
| /** |
| * 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 child space and see mapreduce.cluster.local.dir as |
| * taskTracker/jobCache/jobId/attemptId |
| * This class should not be used from TaskTracker space. |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| public class MapOutputFile { |
| |
| private JobConf conf; |
| |
| static final String REDUCE_INPUT_FILE_FORMAT_STRING = "%s/map_%d.out"; |
| |
| public MapOutputFile() { |
| } |
| |
| private LocalDirAllocator lDirAlloc = |
| new LocalDirAllocator(MRConfig.LOCAL_DIR); |
| |
| /** |
| * Return the path to local map output file created earlier |
| * |
| * @return path |
| * @throws IOException |
| */ |
| public Path getOutputFile() |
| throws IOException { |
| return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + Path.SEPARATOR |
| + "file.out", conf); |
| } |
| |
| /** |
| * Create a local map output file name. |
| * |
| * @param size the size of the file |
| * @return path |
| * @throws IOException |
| */ |
| public Path getOutputFileForWrite(long size) |
| throws IOException { |
| return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + Path.SEPARATOR |
| + "file.out", size, conf); |
| } |
| |
| /** |
| * Return the path to a local map output index file created earlier |
| * |
| * @return path |
| * @throws IOException |
| */ |
| public Path getOutputIndexFile() |
| throws IOException { |
| return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + Path.SEPARATOR |
| + "file.out.index", conf); |
| } |
| |
| /** |
| * Create a local map output index file name. |
| * |
| * @param size the size of the file |
| * @return path |
| * @throws IOException |
| */ |
| public Path getOutputIndexFileForWrite(long size) |
| throws IOException { |
| return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + Path.SEPARATOR |
| + "file.out.index", size, conf); |
| } |
| |
| /** |
| * Return a local map spill file created earlier. |
| * |
| * @param spillNumber the number |
| * @return path |
| * @throws IOException |
| */ |
| public Path getSpillFile(int spillNumber) |
| throws IOException { |
| return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + "/spill" |
| + spillNumber + ".out", conf); |
| } |
| |
| /** |
| * Create a local map spill file name. |
| * |
| * @param spillNumber the number |
| * @param size the size of the file |
| * @return path |
| * @throws IOException |
| */ |
| public Path getSpillFileForWrite(int spillNumber, long size) |
| throws IOException { |
| return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + "/spill" |
| + spillNumber + ".out", size, conf); |
| } |
| |
| /** |
| * Return a local map spill index file created earlier |
| * |
| * @param spillNumber the number |
| * @return path |
| * @throws IOException |
| */ |
| public Path getSpillIndexFile(int spillNumber) |
| throws IOException { |
| return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + "/spill" |
| + spillNumber + ".out.index", conf); |
| } |
| |
| /** |
| * Create a local map spill index file name. |
| * |
| * @param spillNumber the number |
| * @param size the size of the file |
| * @return path |
| * @throws IOException |
| */ |
| public Path getSpillIndexFileForWrite(int spillNumber, long size) |
| throws IOException { |
| return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + "/spill" |
| + spillNumber + ".out.index", size, conf); |
| } |
| |
| /** |
| * Return a local reduce input file created earlier |
| * |
| * @param mapId a map task id |
| * @return path |
| * @throws IOException |
| */ |
| public Path getInputFile(int mapId) |
| throws IOException { |
| return lDirAlloc.getLocalPathToRead(String.format( |
| REDUCE_INPUT_FILE_FORMAT_STRING, TaskTracker.OUTPUT, Integer |
| .valueOf(mapId)), conf); |
| } |
| |
| /** |
| * Create a local reduce input file name. |
| * |
| * @param mapId a map task id |
| * @param size the size of the file |
| * @return path |
| * @throws IOException |
| */ |
| public Path getInputFileForWrite(org.apache.hadoop.mapreduce.TaskID mapId, |
| long size) |
| throws IOException { |
| return lDirAlloc.getLocalPathForWrite(String.format( |
| REDUCE_INPUT_FILE_FORMAT_STRING, TaskTracker.OUTPUT, mapId.getId()), |
| size, conf); |
| } |
| |
| /** Removes all of the files related to a task. */ |
| public void removeAll() |
| throws IOException { |
| conf.deleteLocalFiles(TaskTracker.OUTPUT); |
| } |
| |
| public void setConf(Configuration conf) { |
| if (conf instanceof JobConf) { |
| this.conf = (JobConf) conf; |
| } else { |
| this.conf = new JobConf(conf); |
| } |
| } |
| |
| } |