001 /* 002 * Copyright (c) 2007-2015 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 */ 020 021 package cascading.cascade.planner; 022 023 import java.util.Iterator; 024 import java.util.LinkedList; 025 import java.util.ListIterator; 026 027 import cascading.cascade.CascadeException; 028 import cascading.flow.BaseFlow; 029 import cascading.flow.Flow; 030 import cascading.tap.CompositeTap; 031 import cascading.tap.Tap; 032 import org.jgrapht.graph.SimpleDirectedGraph; 033 034 /** 035 * 036 */ 037 public abstract class TopologyGraph<Vertex> extends SimpleDirectedGraph<Vertex, BaseFlow.FlowHolder> 038 { 039 public TopologyGraph( Flow... flows ) 040 { 041 super( BaseFlow.FlowHolder.class ); 042 043 makeGraph( flows ); 044 } 045 046 private void makeGraph( Flow[] flows ) 047 { 048 for( Flow flow : flows ) 049 { 050 LinkedList<Tap> sources = new LinkedList<Tap>( flow.getSourcesCollection() ); 051 LinkedList<Tap> sinks = new LinkedList<Tap>( flow.getSinksCollection() ); 052 053 sinks.addAll( flow.getCheckpointsCollection() ); 054 055 unwrapCompositeTaps( sources ); 056 unwrapCompositeTaps( sinks ); 057 058 for( Tap source : sources ) 059 addVertex( getVertex( flow, source ) ); 060 061 for( Tap sink : sinks ) 062 addVertex( getVertex( flow, sink ) ); 063 064 for( Tap source : sources ) 065 { 066 for( Tap sink : sinks ) 067 addEdgeFor( flow, source, sink ); 068 } 069 } 070 } 071 072 private void addEdgeFor( Flow flow, Tap source, Tap sink ) 073 { 074 try 075 { 076 addEdge( getVertex( flow, source ), getVertex( flow, sink ), ( (BaseFlow) flow ).getHolder() ); 077 } 078 catch( IllegalArgumentException exception ) 079 { 080 throw new CascadeException( "no loops allowed in cascade, flow: " + flow.getName() + ", source: " + source + ", sink: " + sink ); 081 } 082 } 083 084 abstract protected Vertex getVertex( Flow flow, Tap tap ); 085 086 private void unwrapCompositeTaps( LinkedList<Tap> taps ) 087 { 088 ListIterator<Tap> iterator = taps.listIterator(); 089 090 while( iterator.hasNext() ) 091 { 092 Tap tap = iterator.next(); 093 094 if( tap instanceof CompositeTap ) 095 { 096 iterator.remove(); 097 098 Iterator<Tap> childTaps = ( (CompositeTap) tap ).getChildTaps(); 099 100 while( childTaps.hasNext() ) 101 { 102 iterator.add( childTaps.next() ); 103 iterator.previous(); // force cursor backward 104 } 105 } 106 } 107 } 108 }