001    /*
002     * Copyright (c) 2007-2015 Concurrent, Inc. All Rights Reserved.
003     *
004     * Project and contact information: http://www.cascading.org/
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    
021    package cascading.tap.hadoop.io;
022    
023    import java.io.IOException;
024    
025    import cascading.flow.FlowProcess;
026    import cascading.flow.SliceCounters;
027    import cascading.scheme.Scheme;
028    import cascading.tap.Tap;
029    import cascading.tap.hadoop.util.MeasuredRecordReader;
030    import cascading.tuple.TupleEntrySchemeIterator;
031    import cascading.util.CloseableIterator;
032    import org.apache.hadoop.mapred.JobConf;
033    import org.apache.hadoop.mapred.RecordReader;
034    
035    /**
036     *
037     */
038    public class HadoopTupleEntrySchemeIterator extends TupleEntrySchemeIterator<JobConf, RecordReader>
039      {
040      private MeasuredRecordReader measuredRecordReader;
041    
042      public HadoopTupleEntrySchemeIterator( FlowProcess<JobConf> flowProcess, Tap parentTap, RecordReader recordReader ) throws IOException
043        {
044        this( flowProcess, parentTap.getScheme(), makeIterator( flowProcess, parentTap, recordReader ) );
045        }
046    
047      public HadoopTupleEntrySchemeIterator( FlowProcess<JobConf> flowProcess, Scheme scheme, CloseableIterator<RecordReader> closeableIterator )
048        {
049        super( flowProcess, scheme, closeableIterator, flowProcess.getStringProperty( MultiInputSplit.CASCADING_SOURCE_PATH ) );
050        }
051    
052      private static CloseableIterator<RecordReader> makeIterator( FlowProcess<JobConf> flowProcess, Tap parentTap, RecordReader recordReader ) throws IOException
053        {
054        if( recordReader != null )
055          return new RecordReaderIterator( recordReader );
056    
057        return new MultiRecordReaderIterator( flowProcess, parentTap );
058        }
059    
060      @Override
061      protected RecordReader wrapInput( RecordReader recordReader )
062        {
063        if( measuredRecordReader == null )
064          measuredRecordReader = new MeasuredRecordReader( getFlowProcess(), SliceCounters.Read_Duration );
065    
066        measuredRecordReader.setRecordReader( recordReader );
067    
068        return measuredRecordReader;
069        }
070      }