Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.io.data.output;
020
021import org.apache.reef.tang.annotations.Parameter;
022
023import javax.inject.Inject;
024import java.io.DataOutputStream;
025import java.io.File;
026import java.io.FileOutputStream;
027import java.io.IOException;
028import java.util.logging.Level;
029import java.util.logging.Logger;
030
031/**
032 * Implementation of {@link TaskOutputStreamProvider}.
033 * It provides FileOutputStreams on the local file system.
034 */
035public final class TaskOutputStreamProviderLocal extends TaskOutputStreamProvider {
036  private static final Logger LOG = Logger.getLogger(TaskOutputStreamProviderLocal.class.getName());
037
038  /**
039   * Path of the output directory on the local disk to write outputs.
040   */
041  private final String outputPath;
042
043  /**
044   * Constructor - instantiated via TANG.
045   *
046   * @param outputPath path of the output directory on the local disk to write outputs.
047   */
048  @Inject
049  private TaskOutputStreamProviderLocal(
050      @Parameter(TaskOutputService.OutputPath.class) final String outputPath) {
051    this.outputPath = outputPath;
052  }
053
054  /**
055   * create a file output stream using the given name.
056   * The path of the file on the local file system is 'outputPath/name/taskId'.
057   *
058   * @param name name of the created output stream
059   *             It is used as the name of the directory if the created output stream is a file output stream
060   * @return OutputStream to a file on local file system. The path of the file is 'outputPath/name/taskId'
061   * @throws java.io.IOException
062   */
063  @Override
064  public DataOutputStream create(final String name) throws IOException {
065    final String directoryPath = outputPath + File.separator + name;
066    final File directory = new File(directoryPath);
067
068    synchronized (TaskOutputStreamProviderLocal.class) {
069      if (!directory.exists() && !directory.mkdirs()) {
070        LOG.log(Level.WARNING, "Failed to create [{0}]", directory.getAbsolutePath());
071      }
072    }
073
074    final File file = new File(directoryPath + File.separator + getTaskId());
075    return new DataOutputStream(new FileOutputStream(file));
076  }
077
078  @Override
079  public void close() throws IOException {
080  }
081}