001/*
002 * Copyright (c) 2007-2022 The Cascading Authors. All Rights Reserved.
003 *
004 * Project and contact information: https://cascading.wensel.net/
005 *
006 * This file is part of the Cascading project.
007 *
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *     http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020
021package cascading.tap.hadoop.io;
022
023import java.io.IOException;
024
025import cascading.flow.FlowProcess;
026import cascading.flow.SliceCounters;
027import cascading.scheme.Scheme;
028import cascading.tap.Tap;
029import cascading.tap.hadoop.util.MeasuredRecordReader;
030import cascading.tap.type.FileType;
031import cascading.tuple.TupleEntrySchemeIterator;
032import cascading.util.CloseableIterator;
033import org.apache.hadoop.conf.Configuration;
034import org.apache.hadoop.mapred.RecordReader;
035
036/**
037 *
038 */
039public class HadoopTupleEntrySchemeIterator extends TupleEntrySchemeIterator<Configuration, RecordReader>
040  {
041  private MeasuredRecordReader measuredRecordReader;
042
043  public HadoopTupleEntrySchemeIterator( FlowProcess<? extends Configuration> flowProcess, Tap parentTap, RecordReader recordReader ) throws IOException
044    {
045    this( flowProcess, parentTap, parentTap.getScheme(), makeIterator( flowProcess, parentTap, recordReader ) );
046    }
047
048  @Deprecated
049  public HadoopTupleEntrySchemeIterator( FlowProcess<? extends Configuration> flowProcess, Scheme scheme, CloseableIterator<RecordReader> closeableIterator )
050    {
051    super( flowProcess, scheme, closeableIterator, flowProcess.getStringProperty( FileType.CASCADING_SOURCE_PATH ) );
052    }
053
054  public HadoopTupleEntrySchemeIterator( FlowProcess<? extends Configuration> flowProcess, Tap tap, Scheme scheme, CloseableIterator<RecordReader> closeableIterator )
055    {
056    super( flowProcess, tap, scheme, closeableIterator, flowProcess.getStringProperty( FileType.CASCADING_SOURCE_PATH ) );
057    }
058
059  private static CloseableIterator<RecordReader> makeIterator( FlowProcess<? extends Configuration> flowProcess, Tap parentTap, RecordReader recordReader ) throws IOException
060    {
061    if( recordReader != null )
062      return new RecordReaderIterator( recordReader );
063
064    return new MultiRecordReaderIterator( flowProcess, parentTap );
065    }
066
067  @Override
068  protected RecordReader wrapInput( RecordReader recordReader )
069    {
070    if( measuredRecordReader == null )
071      measuredRecordReader = new MeasuredRecordReader( getFlowProcess(), SliceCounters.Read_Duration );
072
073    measuredRecordReader.setRecordReader( super.wrapInput( recordReader ) );
074
075    return measuredRecordReader;
076    }
077  }