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.loading.impl;
020
021import org.apache.hadoop.io.Writable;
022import org.apache.hadoop.io.WritableComparable;
023import org.apache.reef.io.data.loading.api.DataSet;
024import org.apache.reef.io.network.util.Pair;
025
026import javax.inject.Inject;
027import java.util.ArrayList;
028import java.util.Iterator;
029import java.util.List;
030
031public class InMemoryInputFormatDataSet<K extends WritableComparable<K>, V extends Writable>
032    implements DataSet<K, V> {
033
034  private final InputFormatDataSet<K, V> inputFormatDataSet;
035  private List<Pair<K, V>> recordsList = null;
036
037  @Inject
038  public InMemoryInputFormatDataSet(final InputFormatDataSet<K, V> inputFormatDataSet) {
039    this.inputFormatDataSet = inputFormatDataSet;
040  }
041
042
043  @Override
044  public synchronized Iterator<Pair<K, V>> iterator() {
045    if (recordsList == null) {
046      recordsList = new ArrayList<>();
047      for (final Pair<K, V> keyValue : inputFormatDataSet) {
048        recordsList.add(keyValue);
049      }
050    }
051    return recordsList.iterator();
052  }
053}