    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.stream.element;
    022
    023import java.util.ArrayList;
    024import java.util.List;
    025import java.util.Set;
    026
    027import cascading.flow.FlowElement;
    028import cascading.flow.FlowProcess;
    029import cascading.flow.planner.Scope;
    030import cascading.flow.stream.duct.Stage;
    031import cascading.flow.stream.graph.IORole;
    032import cascading.pipe.Boundary;
    033import cascading.pipe.Pipe;
    034import cascading.tuple.TupleEntry;
    035
    036/**
    037 *
    038 */
    039public abstract class BoundaryStage<Incoming, Outgoing> extends Stage<Incoming, Outgoing> implements ElementDuct
    040  {
    041  protected Boundary boundary;
    042  protected final FlowProcess flowProcess;
    043  protected IORole role = IORole.both;
    044
    045  protected final List<Scope> incomingScopes = new ArrayList<>();
    046  protected final List<Scope> outgoingScopes = new ArrayList<>();
    047
    048  private TrapHandler trapHandler;
    049  private Set<String> branchNames;
    050
    051  public BoundaryStage( FlowProcess flowProcess, Boundary boundary )
    052    {
    053    this.boundary = boundary;
    054
    055    Pipe element = boundary;
    056
    057    while( element != null )
    058      {
    059      if( element.hasConfigDef() )
    060        flowProcess = new ElementFlowProcess( flowProcess, element.getConfigDef() );
    061
    062      element = element.getParent();
    063      }
    064
    065    this.flowProcess = flowProcess;
    066    }
    067
    068  public BoundaryStage( FlowProcess flowProcess, Boundary boundary, IORole role )
    069    {
    070    this.boundary = boundary;
    071    this.flowProcess = flowProcess;
    072    this.role = role;
    073    }
    074
    075  public Boundary getBoundary()
    076    {
    077    return boundary;
    078    }
    079
    080  protected void handleReThrowableException( String message, Throwable throwable )
    081    {
    082    trapHandler.handleReThrowableException( message, throwable );
    083    }
    084
    085  protected void handleException( Throwable exception, TupleEntry tupleEntry )
    086    {
    087    trapHandler.handleException( exception, tupleEntry );
    088    }
    089
    090  @Override
    091  public void initialize()
    092    {
    093    super.initialize();
    094
    095    if( incomingScopes.size() == 0 )
    096      throw new IllegalStateException( "incoming scopes may not be empty" );
    097
    098    if( outgoingScopes.size() == 0 )
    099      throw new IllegalStateException( "outgoing scope may not be empty" );
    100    }
    101
    102  public void setBranchNames( Set<String> branchNames )
    103    {
    104    this.branchNames = branchNames;
    105    }
    106
    107  public Set<String> getBranchNames()
    108    {
    109    return branchNames;
    110    }
    111
    112  @Override
    113  public void setTrapHandler( TrapHandler trapHandler )
    114    {
    115    this.trapHandler = trapHandler;
    116    }
    117
    118  @Override
    119  public boolean hasTrapHandler()
    120    {
    121    return trapHandler != null;
    122    }
    123
    124  @Override
    125  public FlowElement getFlowElement()
    126    {
    127    return boundary;
    128    }
    129
    130  @Override
    131  public List<Scope> getOutgoingScopes()
    132    {
    133    return outgoingScopes;
    134    }
    135
    136  @Override
    137  public List<Scope> getIncomingScopes()
    138    {
    139    return incomingScopes;
    140    }
    141  }