    001/*
    002 * Copyright (c) 2007-2017 Xplenty, 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
    021package cascading.flow.tez.stream.element;
    022
    023import java.io.IOException;
    024
    025import cascading.cascade.CascadeException;
    026import cascading.flow.FlowProcess;
    027import cascading.flow.FlowProcessWrapper;
    028import cascading.flow.stream.element.SourceStage;
    029import cascading.flow.tez.Hadoop2TezFlowProcess;
    030import cascading.flow.tez.util.TezUtil;
    031import cascading.tap.Tap;
    032import org.apache.hadoop.mapred.RecordReader;
    033import org.apache.tez.dag.api.TezConfiguration;
    034import org.apache.tez.mapreduce.input.MRInput;
    035import org.apache.tez.mapreduce.lib.MRReader;
    036import org.apache.tez.runtime.api.LogicalInput;
    037import org.slf4j.Logger;
    038import org.slf4j.LoggerFactory;
    039
    040/**
    041 *
    042 */
    043public class TezSourceStage extends SourceStage
    044  {
    045  private static final Logger LOG = LoggerFactory.getLogger( TezSourceStage.class );
    046
    047  private final MRInput logicalInput;
    048  private MRReader reader;
    049
    050  public TezSourceStage( FlowProcess flowProcess, Tap source, LogicalInput logicalInput )
    051    {
    052    super( flowProcess, source );
    053
    054    if( logicalInput == null )
    055      throw new IllegalArgumentException( "input must not be null" );
    056
    057    this.logicalInput = (MRInput) logicalInput;
    058    }
    059
    060  @Override
    061  public void prepare()
    062    {
    063    LOG.info( "calling {}#start() on: {}", logicalInput.getClass().getSimpleName(), getSource() );
    064
    065    logicalInput.start();
    066
    067    Hadoop2TezFlowProcess tezFlowProcess = (Hadoop2TezFlowProcess) FlowProcessWrapper.undelegate( flowProcess );
    068
    069    TezConfiguration configuration = tezFlowProcess.getConfiguration();
    070
    071    try
    072      {
    073      reader = (MRReader) logicalInput.getReader();
    074      }
    075    catch( IOException exception )
    076      {
    077      throw new CascadeException( "unable to get reader", exception );
    078      }
    079
    080    // set the cascading.source.path property for the current split
    081    // if a TezGroupedSplit, currently won't set
    082    TezUtil.setSourcePathForSplit( logicalInput, reader, configuration );
    083    }
    084
    085  @Override
    086  public void run( Object input ) throws Throwable
    087    {
    088    RecordReader oldRecordReader = (RecordReader) ( reader ).getRecordReader();
    089
    090    super.run( oldRecordReader );
    091    }
    092  }