    001    /*
    002     * Copyright (c) 2007-2014 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      }