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.wake.storage;
020
021import org.apache.reef.wake.EStage;
022import org.apache.reef.wake.EventHandler;
023
024import java.io.FileInputStream;
025import java.io.IOException;
026
027public class SequentialFileReader implements EStage<ReadRequest> {
028  final EventHandler<ReadResponse> dest = null;
029  final FileHandlePool fdPool = new FileHandlePool();
030
031  @Override
032  public void onNext(ReadRequest value) {
033    FileInputStream fin = fdPool.get(value.f);
034    int readSoFar = 0;
035    try {
036      synchronized (fin) {
037        fin.reset();
038        fin.skip(value.offset);
039        while (readSoFar != value.buf.length) {
040          int ret = fin.read(value.buf, readSoFar, value.buf.length);
041          if (ret == -1) {
042            break;
043          }
044          readSoFar += ret;
045        }
046      }
047    } catch (IOException e) {
048      fdPool.release(value.f, fin);
049//      err.onNext(null); //new ReadError(e));
050    }
051    fdPool.release(value.f, fin);
052    dest.onNext(new ReadResponse(value.buf, readSoFar, value.id));
053  }
054
055  @Override
056  public void close() throws Exception {
057    // TODO Auto-generated method stub
058
059  }
060
061}