    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.tap.hadoop;
    022
    023import java.io.IOException;
    024import java.net.URI;
    025import java.util.ArrayList;
    026import java.util.Collection;
    027
    028import cascading.flow.FlowProcess;
    029import cascading.tap.Tap;
    030import cascading.tap.TapException;
    031import org.apache.hadoop.conf.Configuration;
    032import org.apache.hadoop.fs.Path;
    033import org.apache.hadoop.mapred.OutputCollector;
    034import org.apache.hadoop.mapred.RecordReader;
    035
    036/**
    037 *
    038 */
    039public class DistCacheTap extends BaseDistCacheTap
    040  {
    041  public static final String CASCADING_LOCAL_RESOURCES = "cascading.resources.local.";
    042  public static final String CASCADING_REMOTE_RESOURCES = "cascading.resources.remote.";
    043
    044  public DistCacheTap( Tap<Configuration, RecordReader, OutputCollector> original )
    045    {
    046    super( original );
    047    }
    048
    049  @Override
    050  protected Path[] getLocalCacheFiles( FlowProcess<? extends Configuration> flowProcess ) throws IOException
    051    {
    052    String key = CASCADING_REMOTE_RESOURCES + Tap.id( this );
    053    String property = flowProcess.getStringProperty( key );
    054
    055    if( property == null )
    056      throw new TapException( "unable to find local resources property for: " + key );
    057
    058    String[] split = property.split( "," );
    059    Path[] paths = new Path[ split.length ];
    060
    061    for( int i = 0; i < split.length; i++ )
    062      paths[ i ] = new Path( split[ i ] );
    063
    064    return paths;
    065    }
    066
    067  @Override
    068  protected void addLocalCacheFiles( Configuration conf, URI uri )
    069    {
    070    String key = CASCADING_LOCAL_RESOURCES + Tap.id( this );
    071    Collection<String> resources = conf.getStringCollection( key );
    072
    073    if( resources == null )
    074      resources = new ArrayList<>();
    075
    076    resources.add( uri.toString() );
    077
    078    conf.setStrings( key, resources.toArray( new String[ resources.size() ] ) );
    079    }
    080  }