    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.Closeable;
    024import java.io.IOException;
    025
    026import cascading.flow.FlowProcess;
    027import cascading.flow.hadoop.MapRed;
    028import cascading.tap.Tap;
    029import cascading.tap.TapException;
    030import cascading.tap.hadoop.util.Hadoop18TapUtil;
    031import org.apache.hadoop.conf.Configuration;
    032import org.apache.hadoop.fs.Path;
    033import org.apache.hadoop.mapred.FileOutputFormat;
    034import org.apache.hadoop.mapred.OutputCollector;
    035import org.apache.hadoop.mapred.OutputFormat;
    036import org.apache.hadoop.mapred.RecordReader;
    037import org.apache.hadoop.mapred.RecordWriter;
    038import org.apache.hadoop.mapred.Reporter;
    039import org.slf4j.Logger;
    040import org.slf4j.LoggerFactory;
    041
    042import static cascading.flow.hadoop.util.HadoopUtil.asJobConfInstance;
    043
    044/**
    045 *
    046 */
    047public class TapOutputCollector implements OutputCollector, Closeable
    048  {
    049  private static final Logger LOG = LoggerFactory.getLogger( TapOutputCollector.class );
    050
    051  public static final String PART_TASK_PATTERN = "%s%spart-%05d";
    052  public static final String PART_TASK_SEQ_PATTERN = "%s%spart-%05d-%05d";
    053
    054  /** Field conf */
    055  private Configuration conf;
    056  /** Field writer */
    057  private RecordWriter writer;
    058  /** Field filenamePattern */
    059  private String filenamePattern;
    060  /** Field filename */
    061  private String filename;
    062  /** Field tap */
    063  private Tap<Configuration, RecordReader, OutputCollector> tap;
    064  /** Field prefix */
    065  private String prefix;
    066  /** Field sequence */
    067  private long sequence;
    068  /** Field isFileOutputFormat */
    069  private boolean isFileOutputFormat;
    070  private final FlowProcess<? extends Configuration> flowProcess;
    071
    072  public TapOutputCollector( FlowProcess<? extends Configuration> flowProcess, Tap<Configuration, RecordReader, OutputCollector> tap ) throws IOException
    073    {
    074    this( flowProcess, tap, null );
    075    }
    076
    077  public TapOutputCollector( FlowProcess<? extends Configuration> flowProcess, Tap<Configuration, RecordReader, OutputCollector> tap, String prefix ) throws IOException
    078    {
    079    this( flowProcess, tap, prefix, -1 );
    080    }
    081
    082  public TapOutputCollector( FlowProcess<? extends Configuration> flowProcess, Tap<Configuration, RecordReader, OutputCollector> tap, String prefix, long sequence ) throws IOException
    083    {
    084    this.tap = tap;
    085    this.sequence = sequence;
    086    this.prefix = prefix == null || prefix.length() == 0 ? null : prefix;
    087    this.flowProcess = flowProcess;
    088    this.conf = this.flowProcess.getConfigCopy();
    089    this.filenamePattern = this.conf.get( "cascading.tapcollector.partname", sequence == -1 ? PART_TASK_PATTERN : PART_TASK_SEQ_PATTERN );
    090
    091    initialize();
    092    }
    093
    094  protected void initialize() throws IOException
    095    {
    096    tap.sinkConfInit( flowProcess, conf );
    097
    098    OutputFormat outputFormat = asJobConfInstance( conf ).getOutputFormat();
    099
    100    // todo: use OutputCommitter class
    101
    102    isFileOutputFormat = outputFormat instanceof FileOutputFormat;
    103
    104    if( isFileOutputFormat )
    105      {
    106      Hadoop18TapUtil.setupJob( conf );
    107      Hadoop18TapUtil.setupTask( conf );
    108
    109      int partition = conf.getInt( "mapred.task.partition", conf.getInt( "mapreduce.task.partition", 0 ) );
    110
    111      if( prefix != null )
    112        filename = String.format( filenamePattern, prefix, "/", partition, sequence );
    113      else
    114        filename = String.format( filenamePattern, "", "", partition, sequence );
    115      }
    116
    117    LOG.info( "creating path: {}", filename );
    118
    119    writer = outputFormat.getRecordWriter( null, asJobConfInstance( conf ), filename, getReporter() );
    120    }
    121
    122  private Reporter getReporter()
    123    {
    124    Reporter reporter = Reporter.NULL;
    125
    126    if( flowProcess instanceof MapRed )
    127      reporter = ( (MapRed) flowProcess ).getReporter(); // may return Reporter.NULL
    128
    129    return reporter;
    130    }
    131
    132  /**
    133   * Method collect writes the given values to the {@link Tap} this instance encapsulates.
    134   *
    135   * @param writableComparable of type WritableComparable
    136   * @param writable           of type Writable
    137   * @throws IOException when
    138   */
    139  public void collect( Object writableComparable, Object writable ) throws IOException
    140    {
    141    flowProcess.keepAlive();
    142    writer.write( writableComparable, writable );
    143    }
    144
    145  public void close()
    146    {
    147    try
    148      {
    149      if( isFileOutputFormat )
    150        LOG.info( "closing tap collector for: {}", new Path( tap.getIdentifier(), filename ) );
    151      else
    152        LOG.info( "closing tap collector for: {}", tap );
    153
    154      try
    155        {
    156        writer.close( getReporter() );
    157        }
    158      finally
    159        {
    160        if( isFileOutputFormat )
    161          {
    162          if( Hadoop18TapUtil.needsTaskCommit( conf ) )
    163            Hadoop18TapUtil.commitTask( conf );
    164
    165          Hadoop18TapUtil.cleanupJob( conf );
    166          }
    167        }
    168      }
    169    catch( IOException exception )
    170      {
    171      LOG.warn( "exception closing: {}", filename, exception );
    172      throw new TapException( "exception closing: " + filename, exception );
    173      }
    174    }
    175  }