    001/*
    002 * Copyright (c) 2007-2016 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
    021package cascading.tap.hadoop.io;
    022
    023import java.io.IOException;
    024
    025import cascading.flow.FlowProcess;
    026import cascading.flow.SliceCounters;
    027import cascading.tap.Tap;
    028import cascading.tap.hadoop.util.MeasuredOutputCollector;
    029import cascading.tuple.TupleEntrySchemeCollector;
    030import org.apache.hadoop.conf.Configuration;
    031import org.apache.hadoop.mapred.OutputCollector;
    032import org.apache.hadoop.mapred.RecordReader;
    033
    034/**
    035 * Class HadoopTupleEntrySchemeCollector is a kind of {@link cascading.tuple.TupleEntryCollector} that writes tuples to the resource managed by
    036 * a particular {@link cascading.tap.Tap} instance.
    037 */
    038public class HadoopTupleEntrySchemeCollector extends TupleEntrySchemeCollector<Configuration, OutputCollector>
    039  {
    040  private MeasuredOutputCollector measuredOutputCollector;
    041
    042  public HadoopTupleEntrySchemeCollector( FlowProcess<? extends Configuration> flowProcess, Tap<Configuration, RecordReader, OutputCollector> tap ) throws IOException
    043    {
    044    super( flowProcess, tap.getScheme(), makeCollector( flowProcess, tap, null ), tap.getIdentifier() );
    045    }
    046
    047  public HadoopTupleEntrySchemeCollector( FlowProcess<? extends Configuration> flowProcess, Tap<Configuration, RecordReader, OutputCollector> tap, OutputCollector outputCollector ) throws IOException
    048    {
    049    super( flowProcess, tap.getScheme(), makeCollector( flowProcess, tap, outputCollector ), tap.getIdentifier() );
    050    }
    051
    052  private static OutputCollector makeCollector( FlowProcess<? extends Configuration> flowProcess, Tap<Configuration, RecordReader, OutputCollector> tap, OutputCollector outputCollector ) throws IOException
    053    {
    054    if( outputCollector != null )
    055      return outputCollector;
    056
    057    return new TapOutputCollector( flowProcess, tap );
    058    }
    059
    060  @Override
    061  protected OutputCollector<?, ?> wrapOutput( OutputCollector outputCollector )
    062    {
    063    if( measuredOutputCollector == null )
    064      measuredOutputCollector = new MeasuredOutputCollector( getFlowProcess(), SliceCounters.Write_Duration );
    065
    066    measuredOutputCollector.setOutputCollector( outputCollector );
    067
    068    return measuredOutputCollector;
    069    }
    070  }