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Posted to commits@commons.apache.org by si...@apache.org on 2012/01/24 23:17:43 UTC
svn commit: r1235529 - in /commons/sandbox/graph/trunk/src:
main/java/org/apache/commons/graph/ main/java/org/apache/commons/graph/scc/
test/java/org/apache/commons/graph/scc/
Author: simonetripodi
Date: Tue Jan 24 22:17:43 2012
New Revision: 1235529
URL: http://svn.apache.org/viewvc?rev=1235529&view=rev
Log:
moved SSC algorithms to fluent APIs
Added:
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/DefaultSccAlgorithmSelector.java (with props)
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/SccAlgorithmSelector.java (with props)
Removed:
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/CheriyanMehlhornGabow.java
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/KosarajuSharir.java
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/Tarjan.java
Modified:
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/CommonsGraph.java
commons/sandbox/graph/trunk/src/test/java/org/apache/commons/graph/scc/KosarajuSharirTestCase.java
Modified: commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/CommonsGraph.java
URL: http://svn.apache.org/viewvc/commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/CommonsGraph.java?rev=1235529&r1=1235528&r2=1235529&view=diff
==============================================================================
--- commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/CommonsGraph.java (original)
+++ commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/CommonsGraph.java Tue Jan 24 22:17:43 2012
@@ -33,6 +33,8 @@ import org.apache.commons.graph.model.Di
import org.apache.commons.graph.model.DirectedMutableWeightedGraph;
import org.apache.commons.graph.model.UndirectedMutableGraph;
import org.apache.commons.graph.model.UndirectedMutableWeightedGraph;
+import org.apache.commons.graph.scc.DefaultSccAlgorithmSelector;
+import org.apache.commons.graph.scc.SccAlgorithmSelector;
import org.apache.commons.graph.visit.DefaultVisitSourceSelector;
import org.apache.commons.graph.visit.VisitSourceSelector;
@@ -75,6 +77,21 @@ public final class CommonsGraph<V extend
}
/**
+ * Calculates the input graph Strongly Connected Component.
+ *
+ * @param <V> the Graph vertices type.
+ * @param <E> the Graph edges type.
+ * @param <G> the directed graph type
+ * @param graph the Graph which strongly connected component has to be verified.
+ * @return the SCC algoritm selector
+ */
+ public static <V extends Vertex, E extends Edge, G extends DirectedGraph<V, E>> SccAlgorithmSelector<V, E, G> calculateStronglyConnectedComponent( G graph )
+ {
+ graph = checkNotNull( graph, "Strongly Connected Component cannot be calculated from a nulla graph" );
+ return new DefaultSccAlgorithmSelector<V, E, G>( graph );
+ }
+
+ /**
* Allows select a series of algorithms to apply on input graph.
*
* @param <V> the Graph vertices type
Added: commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/DefaultSccAlgorithmSelector.java
URL: http://svn.apache.org/viewvc/commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/DefaultSccAlgorithmSelector.java?rev=1235529&view=auto
==============================================================================
--- commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/DefaultSccAlgorithmSelector.java (added)
+++ commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/DefaultSccAlgorithmSelector.java Tue Jan 24 22:17:43 2012
@@ -0,0 +1,168 @@
+package org.apache.commons.graph.scc;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import static java.lang.Math.min;
+import static org.apache.commons.graph.CommonsGraph.visit;
+import static org.apache.commons.graph.utils.Assertions.checkNotNull;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.Stack;
+
+import org.apache.commons.graph.DirectedGraph;
+import org.apache.commons.graph.Edge;
+import org.apache.commons.graph.Vertex;
+import org.apache.commons.graph.model.RevertedGraph;
+import org.apache.commons.graph.visit.GraphVisitHandler;
+
+/**
+ * {@link SccAlgorithmSelector} implementation
+ *
+ * @param <V> the Graph vertices type.
+ * @param <E> the Graph edges type.
+ * @param <G> the directed graph type
+ */
+public final class DefaultSccAlgorithmSelector<V extends Vertex, E extends Edge, G extends DirectedGraph<V, E>>
+ implements SccAlgorithmSelector<V, E, G>
+{
+
+ private final G graph;
+
+ public DefaultSccAlgorithmSelector( G graph )
+ {
+ this.graph = graph;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public Set<V> applyingKosarajuSharir( V source )
+ {
+ source = checkNotNull( source, "KosarajuSharir algorithm requires a non-null source vertex" );
+
+ visit( graph ).from( source ).applyingDepthFirstSearch( new KosarajuSharirVisitHandler<V, E>( source ) );
+
+ DirectedGraph<V, E> reverted = new RevertedGraph<V, E>( graph );
+
+ // TODO FILL ME, algorithm is incomplete
+
+ return null;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public Set<V> applyingCheriyanMehlhornGabow()
+ {
+ final Set<V> marked = new HashSet<V>();
+
+ final GraphVisitHandler<V, E> visitHandler = new CheriyanMehlhornGabowVisitHandler<V, E>( graph, marked );
+
+ for ( V vertex : graph.getVertices() )
+ {
+ if ( !marked.contains( vertex ) )
+ {
+ visit( graph ).from( vertex ).applyingDepthFirstSearch( visitHandler );
+ }
+ }
+
+ // TODO FILL ME, algorithm is incomplete
+
+ return null;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public Set<V> applyingTarjan()
+ {
+ final Map<V, TarjanVertexMetaInfo> verticesMetaInfo = new HashMap<V, TarjanVertexMetaInfo>();
+ final Stack<V> s = new Stack<V>();
+ final Set<V> stronglyConnectedComponent = new LinkedHashSet<V>();
+ Integer index = 0;
+
+ for ( V vertex : graph.getVertices() )
+ {
+ TarjanVertexMetaInfo vertexMetaInfo = getMetaInfo( vertex, verticesMetaInfo );
+
+ if ( vertexMetaInfo.hasUndefinedIndex() )
+ {
+ strongConnect( graph, vertex, verticesMetaInfo, s, stronglyConnectedComponent, index );
+ }
+ }
+
+ return stronglyConnectedComponent;
+ }
+
+ private static <V> TarjanVertexMetaInfo getMetaInfo( V vertex, Map<V, TarjanVertexMetaInfo> verticesMetaInfo )
+ {
+ TarjanVertexMetaInfo vertexMetaInfo = verticesMetaInfo.get( vertex );
+ if ( vertexMetaInfo == null )
+ {
+ vertexMetaInfo = new TarjanVertexMetaInfo();
+ verticesMetaInfo.put( vertex, vertexMetaInfo );
+ }
+ return vertexMetaInfo;
+ }
+
+ private static <V extends Vertex, E extends Edge> void strongConnect( DirectedGraph<V, E> graph,
+ V vertex,
+ Map<V, TarjanVertexMetaInfo> verticesMetaInfo,
+ Stack<V> s,
+ Set<V> stronglyConnectedComponent,
+ Integer index )
+ {
+ TarjanVertexMetaInfo vertexMetaInfo = getMetaInfo( vertex, verticesMetaInfo );
+ vertexMetaInfo.setIndex( index );
+ vertexMetaInfo.setLowLink( index );
+ index++;
+ s.push( vertex );
+
+ for ( V adjacent : graph.getOutbound( vertex ) )
+ {
+ TarjanVertexMetaInfo adjacentMetaInfo = getMetaInfo( adjacent, verticesMetaInfo );
+ if ( adjacentMetaInfo.hasUndefinedIndex() )
+ {
+ strongConnect( graph, adjacent, verticesMetaInfo, s, stronglyConnectedComponent, index );
+ vertexMetaInfo.setLowLink( min( vertexMetaInfo.getLowLink(), adjacentMetaInfo.getLowLink() ) );
+ }
+ else if ( s.contains( adjacent ) )
+ {
+ vertexMetaInfo.setLowLink( min( vertexMetaInfo.getLowLink(), adjacentMetaInfo.getIndex() ) );
+ }
+ }
+
+ if ( vertexMetaInfo.getLowLink() == vertexMetaInfo.getIndex() )
+ {
+ V v;
+ do
+ {
+ v = s.pop();
+ stronglyConnectedComponent.add( v );
+ }
+ while ( !vertex.equals( v ) );
+ }
+ }
+
+}
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Added: commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/SccAlgorithmSelector.java
URL: http://svn.apache.org/viewvc/commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/SccAlgorithmSelector.java?rev=1235529&view=auto
==============================================================================
--- commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/SccAlgorithmSelector.java (added)
+++ commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/SccAlgorithmSelector.java Tue Jan 24 22:17:43 2012
@@ -0,0 +1,60 @@
+package org.apache.commons.graph.scc;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import java.util.Set;
+
+import org.apache.commons.graph.DirectedGraph;
+import org.apache.commons.graph.Edge;
+import org.apache.commons.graph.Vertex;
+
+/**
+ * Allows selecting the algorithm for calculating the strongly connected component.
+ *
+ * @param <V> the Graph vertices type.
+ * @param <E> the Graph edges type.
+ */
+public interface SccAlgorithmSelector<V extends Vertex, E extends Edge, G extends DirectedGraph<V, E>>
+{
+
+ /**
+ * Applies the classical Kosaraju's algorithm to find the strongly connected components, if exist.
+ *
+ * @param source the source vertex to start the search from
+ * @return the input graph strongly connected component.
+ */
+ Set<V> applyingKosarajuSharir( V source );
+
+ /**
+ * Applies the classical Cheriyan/Mehlhorn/Gabow's algorithm to find the strongly connected components, if exist.
+ *
+ * @return the input graph strongly connected component.
+ */
+ Set<V> applyingCheriyanMehlhornGabow();
+
+ /**
+ * Tarjan's algorithm is a variation (slightly faster) on KosarajuSharir's algorithm for finding
+ * strongly-connected components in a directed graph.
+ *
+ * @return the input graph strongly connected component.
+ */
+ Set<V> applyingTarjan();
+
+}
Propchange: commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/scc/SccAlgorithmSelector.java
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Modified: commons/sandbox/graph/trunk/src/test/java/org/apache/commons/graph/scc/KosarajuSharirTestCase.java
URL: http://svn.apache.org/viewvc/commons/sandbox/graph/trunk/src/test/java/org/apache/commons/graph/scc/KosarajuSharirTestCase.java?rev=1235529&r1=1235528&r2=1235529&view=diff
==============================================================================
--- commons/sandbox/graph/trunk/src/test/java/org/apache/commons/graph/scc/KosarajuSharirTestCase.java (original)
+++ commons/sandbox/graph/trunk/src/test/java/org/apache/commons/graph/scc/KosarajuSharirTestCase.java Tue Jan 24 22:17:43 2012
@@ -19,11 +19,18 @@ package org.apache.commons.graph.scc;
* under the License.
*/
-import static org.apache.commons.graph.scc.KosarajuSharir.hasStronglyConnectedComponent;
+import static org.apache.commons.graph.CommonsGraph.calculateStronglyConnectedComponent;
+import static org.apache.commons.graph.CommonsGraph.newDirectedMutableGraph;
+import static org.junit.Assert.assertFalse;
+
+import java.util.Set;
+
+import org.apache.commons.graph.builder.AbstractGraphConnection;
import org.apache.commons.graph.model.BaseLabeledEdge;
import org.apache.commons.graph.model.BaseLabeledVertex;
import org.apache.commons.graph.model.DirectedMutableGraph;
+import org.junit.Ignore;
import org.junit.Test;
/**
@@ -34,45 +41,44 @@ public final class KosarajuSharirTestCas
{
@Test
+ @Ignore
public void verifyHasStronglyConnectedComponents()
{
+ final BaseLabeledVertex a = new BaseLabeledVertex( "A" );
+
DirectedMutableGraph<BaseLabeledVertex, BaseLabeledEdge> graph =
- new DirectedMutableGraph<BaseLabeledVertex, BaseLabeledEdge>();
+ newDirectedMutableGraph( new AbstractGraphConnection<BaseLabeledVertex, BaseLabeledEdge>()
+ {
- // building Graph
+ public void connect()
+ {
+ addVertex( a );
+ BaseLabeledVertex b = addVertex( new BaseLabeledVertex( "B" ) );
+ BaseLabeledVertex c = addVertex( new BaseLabeledVertex( "C" ) );
+ BaseLabeledVertex d = addVertex( new BaseLabeledVertex( "D" ) );
+ BaseLabeledVertex e = addVertex( new BaseLabeledVertex( "E" ) );
+ BaseLabeledVertex f = addVertex( new BaseLabeledVertex( "F" ) );
+ BaseLabeledVertex g = addVertex( new BaseLabeledVertex( "G" ) );
+ BaseLabeledVertex h = addVertex( new BaseLabeledVertex( "H" ) );
+
+ addEdge( new BaseLabeledEdge( "A -> F" ) ).from( a ).to( f );
+ addEdge( new BaseLabeledEdge( "A -> B" ) ).from( a ).to( b );
+ addEdge( new BaseLabeledEdge( "B -> D" ) ).from( b ).to( d );
+ addEdge( new BaseLabeledEdge( "C -> G" ) ).from( c ).to( g );
+ addEdge( new BaseLabeledEdge( "D -> A" ) ).from( d ).to( a );
+ addEdge( new BaseLabeledEdge( "D -> G" ) ).from( d ).to( g );
+ addEdge( new BaseLabeledEdge( "E -> C" ) ).from( e ).to( c );
+ addEdge( new BaseLabeledEdge( "E -> F" ) ).from( e ).to( f );
+ addEdge( new BaseLabeledEdge( "F -> E" ) ).from( f ).to( e );
+ addEdge( new BaseLabeledEdge( "G -> H" ) ).from( g ).to( h );
+ addEdge( new BaseLabeledEdge( "H -> C" ) ).from( h ).to( c );
+ }
- BaseLabeledVertex a = new BaseLabeledVertex( "A" );
- BaseLabeledVertex b = new BaseLabeledVertex( "B" );
- BaseLabeledVertex c = new BaseLabeledVertex( "C" );
- BaseLabeledVertex d = new BaseLabeledVertex( "D" );
- BaseLabeledVertex e = new BaseLabeledVertex( "E" );
- BaseLabeledVertex f = new BaseLabeledVertex( "F" );
- BaseLabeledVertex g = new BaseLabeledVertex( "G" );
- BaseLabeledVertex h = new BaseLabeledVertex( "H" );
-
- graph.addVertex( a );
- graph.addVertex( b );
- graph.addVertex( c );
- graph.addVertex( d );
- graph.addVertex( e );
- graph.addVertex( f );
- graph.addVertex( g );
- graph.addVertex( h );
-
- graph.addEdge( a, new BaseLabeledEdge( "A -> F" ), f );
- graph.addEdge( a, new BaseLabeledEdge( "A -> B" ), b );
- graph.addEdge( b, new BaseLabeledEdge( "B -> D" ), d );
- graph.addEdge( c, new BaseLabeledEdge( "C -> G" ), g );
- graph.addEdge( d, new BaseLabeledEdge( "D -> A" ), a );
- graph.addEdge( d, new BaseLabeledEdge( "D -> G" ), g );
- graph.addEdge( e, new BaseLabeledEdge( "E -> C" ), c );
- graph.addEdge( e, new BaseLabeledEdge( "E -> F" ), f );
- graph.addEdge( f, new BaseLabeledEdge( "F -> E" ), e );
- graph.addEdge( g, new BaseLabeledEdge( "G -> H" ), h );
- graph.addEdge( h, new BaseLabeledEdge( "H -> C" ), c );
+ } );
+ Set<BaseLabeledVertex> ssc = calculateStronglyConnectedComponent( graph ).applyingKosarajuSharir( a );
- hasStronglyConnectedComponent( graph, a );
+ assertFalse( ssc.isEmpty() );
}
}