| /** |
| * 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.conf.Configurable; |
| import org.apache.hadoop.fs.Path; |
| |
| /** |
| * 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 abstract class MapOutputFile implements Configurable { |
| |
| private Configuration conf; |
| |
| static final String MAP_OUTPUT_FILENAME_STRING = "file.out"; |
| static final String MAP_OUTPUT_INDEX_SUFFIX_STRING = ".index"; |
| static final String REDUCE_INPUT_FILE_FORMAT_STRING = "%s/map_%d.out"; |
| |
| public MapOutputFile() { |
| } |
| |
| /** |
| * Return the path to local map output file created earlier |
| * |
| * @return path |
| * @throws IOException |
| */ |
| public abstract Path getOutputFile() throws IOException; |
| |
| /** |
| * Create a local map output file name. |
| * |
| * @param size the size of the file |
| * @return path |
| * @throws IOException |
| */ |
| public abstract Path getOutputFileForWrite(long size) throws IOException; |
| |
| /** |
| * Create a local map output file name on the same volume. |
| */ |
| public abstract Path getOutputFileForWriteInVolume(Path existing); |
| |
| /** |
| * Return the path to a local map output index file created earlier |
| * |
| * @return path |
| * @throws IOException |
| */ |
| public abstract Path getOutputIndexFile() throws IOException; |
| |
| /** |
| * Create a local map output index file name. |
| * |
| * @param size the size of the file |
| * @return path |
| * @throws IOException |
| */ |
| public abstract Path getOutputIndexFileForWrite(long size) throws IOException; |
| |
| /** |
| * Create a local map output index file name on the same volume. |
| */ |
| public abstract Path getOutputIndexFileForWriteInVolume(Path existing); |
| |
| /** |
| * Return a local map spill file created earlier. |
| * |
| * @param spillNumber the number |
| * @return path |
| * @throws IOException |
| */ |
| public abstract Path getSpillFile(int spillNumber) throws IOException; |
| |
| /** |
| * Create a local map spill file name. |
| * |
| * @param spillNumber the number |
| * @param size the size of the file |
| * @return path |
| * @throws IOException |
| */ |
| public abstract Path getSpillFileForWrite(int spillNumber, long size) |
| throws IOException; |
| |
| /** |
| * Return a local map spill index file created earlier |
| * |
| * @param spillNumber the number |
| * @return path |
| * @throws IOException |
| */ |
| public abstract Path getSpillIndexFile(int spillNumber) throws IOException; |
| |
| /** |
| * Create a local map spill index file name. |
| * |
| * @param spillNumber the number |
| * @param size the size of the file |
| * @return path |
| * @throws IOException |
| */ |
| public abstract Path getSpillIndexFileForWrite(int spillNumber, long size) |
| throws IOException; |
| |
| /** |
| * Return a local reduce input file created earlier |
| * |
| * @param mapId a map task id |
| * @return path |
| * @throws IOException |
| */ |
| public abstract Path getInputFile(int mapId) throws IOException; |
| |
| /** |
| * 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 abstract Path getInputFileForWrite( |
| org.apache.hadoop.mapreduce.TaskID mapId, long size) throws IOException; |
| |
| /** Removes all of the files related to a task. */ |
| public abstract void removeAll() throws IOException; |
| |
| @Override |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| } |
| |
| @Override |
| public Configuration getConf() { |
| return conf; |
| } |
| |
| } |