org.jgrapht.graph.guava

Class MutableValueGraphAdapter<V,W>

java.lang.Object

org.jgrapht.graph.AbstractGraph<V,com.google.common.graph.EndpointPair<V>>

org.jgrapht.graph.guava.BaseValueGraphAdapter<V,W,com.google.common.graph.MutableValueGraph<V,W>>

org.jgrapht.graph.guava.MutableValueGraphAdapter<V,W>

Type Parameters:

V - the graph vertex type

W - the value type

All Implemented Interfaces:

Serializable, Cloneable, Graph<V,com.google.common.graph.EndpointPair<V>>

Direct Known Subclasses:

MutableDoubleValueGraphAdapter

public class MutableValueGraphAdapter<V,W>
extends BaseValueGraphAdapter<V,W,com.google.common.graph.MutableValueGraph<V,W>>
implements Graph<V,com.google.common.graph.EndpointPair<V>>, Cloneable, Serializable

A graph adapter class using Guava's MutableValueGraph.

The adapter uses class EndpointPair to represent edges. Changes in the adapter such as adding or removing vertices and edges are reflected in the underlying value graph.

The class uses a converter from Guava's values to JGraphT's double weights. Thus, the resulting graph is weighted. Assume for example that the following class is the value type:

 class MyValue
     implements
     Serializable
 {
     private double value;

     public MyValue(double value)
     {
         this.value = value;
     }

     public double getValue()
     {
         return value;
     }
 }
 

Then one could create an adapter using the following code:

 MutableValueGraph<String, MyValue> valueGraph =
     ValueGraphBuilder.directed().allowsSelfLoops(true).build();
 valueGraph.addNode("v1");
 valueGraph.addNode("v2");
 valueGraph.putEdgeValue("v1", "v2", new MyValue(5.0));
 
 Graph<String, EndpointPair<String>> graph = new MutableValueGraphAdapter<>(
     valueGraph, new MyValue(1.0), (ToDoubleFunction<MyValue> & Serializable) MyValue::getValue);
 
 double weight = graph.getEdgeWeight(EndpointPair.ordered("v1", "v2")); // should return 5.0
 

This is a one-way conversion meaning that calling setEdgeWeight(EndpointPair, double) will throw an unsupported operation exception. Adjusting the weights can be done directly (by keeping an external reference) on the underlying MutableValueGraph and calling MutableValueGraph.putEdgeValue(Object, Object, Object). Changes on the values will be propagated upstream using the provided value converter.

Author:

Dimitrios Michail

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected W	defaultValue

Fields inherited from class org.jgrapht.graph.guava.BaseValueGraphAdapter

edgeSupplier, LOOPS_NOT_ALLOWED, unmodifiableEdgeSet, unmodifiableVertexSet, valueConverter, valueGraph, vertexSupplier

Fields inherited from interface org.jgrapht.Graph

DEFAULT_EDGE_WEIGHT

Constructor Summary

Constructors

Constructor and Description
MutableValueGraphAdapter(com.google.common.graph.MutableValueGraph<V,W> valueGraph, W defaultValue, ToDoubleFunction<W> valueConverter) Create a new adapter.
MutableValueGraphAdapter(com.google.common.graph.MutableValueGraph<V,W> valueGraph, W defaultValue, ToDoubleFunction<W> valueConverter, Supplier<V> vertexSupplier, Supplier<com.google.common.graph.EndpointPair<V>> edgeSupplier) Create a new adapter.

Method Summary

Modifier and Type	Method and Description
com.google.common.graph.EndpointPair<V>	addEdge(V sourceVertex, V targetVertex) Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge.
boolean	addEdge(V sourceVertex, V targetVertex, com.google.common.graph.EndpointPair<V> e) Adds the specified edge to this graph, going from the source vertex to the target vertex.
V	addVertex() Creates a new vertex in this graph and returns it.
boolean	addVertex(V v) Adds the specified vertex to this graph if not already present.
Object	clone() Returns a shallow copy of this graph instance.
boolean	removeEdge(com.google.common.graph.EndpointPair<V> e) Removes the specified edge from the graph.
com.google.common.graph.EndpointPair<V>	removeEdge(V sourceVertex, V targetVertex) Removes an edge going from source vertex to target vertex, if such vertices and such edge exist in this graph.
boolean	removeVertex(V v) Removes the specified vertex from this graph including all its touching edges if present.
void	setEdgeWeight(com.google.common.graph.EndpointPair<V> e, double weight) Assigns a weight to an edge.

Methods inherited from class org.jgrapht.graph.guava.BaseValueGraphAdapter

containsEdge, containsVertex, degreeOf, edgeSet, edgesOf, getAllEdges, getEdge, getEdgeSource, getEdgeSupplier, getEdgeTarget, getEdgeWeight, getType, getVertexSupplier, incomingEdgesOf, inDegreeOf, outDegreeOf, outgoingEdgesOf, setEdgeSupplier, setVertexSupplier, vertexSet

Methods inherited from class org.jgrapht.graph.AbstractGraph

assertVertexExist, containsEdge, equals, hashCode, removeAllEdges, removeAllEdges, removeAllEdges, removeAllVertices, toString, toStringFromSets

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.jgrapht.Graph

containsEdge, containsEdge, containsVertex, degreeOf, edgeSet, edgesOf, getAllEdges, getEdge, getEdgeSource, getEdgeSupplier, getEdgeTarget, getEdgeWeight, getType, getVertexSupplier, incomingEdgesOf, inDegreeOf, outDegreeOf, outgoingEdgesOf, removeAllEdges, removeAllEdges, removeAllVertices, setEdgeWeight, vertexSet

Field Detail

defaultValue

protected final W defaultValue

Constructor Detail

MutableValueGraphAdapter

public MutableValueGraphAdapter(com.google.common.graph.MutableValueGraph<V,W> valueGraph,
                                W defaultValue,
                                ToDoubleFunction<W> valueConverter)

Create a new adapter.

Parameters:

valueGraph - the value graph

defaultValue - a default value to be used when creating new edges

valueConverter - a function that converts a value to a double

MutableValueGraphAdapter

public MutableValueGraphAdapter(com.google.common.graph.MutableValueGraph<V,W> valueGraph,
                                W defaultValue,
                                ToDoubleFunction<W> valueConverter,
                                Supplier<V> vertexSupplier,
                                Supplier<com.google.common.graph.EndpointPair<V>> edgeSupplier)

Create a new adapter.

Parameters:

valueGraph - the value graph

defaultValue - a default value to be used when creating new edges

valueConverter - a function that converts a value to a double

vertexSupplier - the vertex supplier

edgeSupplier - the edge supplier

Method Detail

addEdge

public com.google.common.graph.EndpointPair<V> addEdge(V sourceVertex,
                                                       V targetVertex)

Description copied from interface: Graph

Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge. Some graphs do not allow edge-multiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, than this method does not change the graph and returns null.

The source and target vertices must already be contained in this graph. If they are not found in graph IllegalArgumentException is thrown.

This method creates the new edge e using this graph's edge supplier (see Graph.getEdgeSupplier()). For the new edge to be added e must not be equal to any other edge the graph (even if the graph allows edge-multiplicity). More formally, the graph must not contain any edge e2 such that e2.equals(e). If such e2 is found then the newly created edge e is abandoned, the method leaves this graph unchanged and returns null.

If the underlying graph implementation's Graph.getEdgeSupplier() returns null, then this method cannot create edges and throws an UnsupportedOperationException.

Specified by:

addEdge in interface Graph<V,com.google.common.graph.EndpointPair<V>>

Parameters:

sourceVertex - source vertex of the edge.

targetVertex - target vertex of the edge.

Returns:

The newly created edge if added to the graph, otherwise null.

See Also:

Graph.getEdgeSupplier()

addEdge

public boolean addEdge(V sourceVertex,
                       V targetVertex,
                       com.google.common.graph.EndpointPair<V> e)

Adds the specified edge to this graph, going from the source vertex to the target vertex. More formally, adds the specified edge, e, to this graph if this graph contains no edge e2 such that e2.equals(e). If this graph already contains such an edge, the call leaves this graph unchanged and returns false. Some graphs do not allow edge-multiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, than this method does not change the graph and returns false. If the edge was added to the graph, returns true.

The source and target vertices must already be contained in this graph. If they are not found in graph IllegalArgumentException is thrown.

The provided edge object can either be null or must respect the source and target vertices that are provided as parameters.

Specified by:

addEdge in interface Graph<V,com.google.common.graph.EndpointPair<V>>

Parameters:

sourceVertex - source vertex of the edge.

targetVertex - target vertex of the edge.

e - edge to be added to this graph.

Returns:

true if this graph did not already contain the specified edge.

Throws:

IllegalArgumentException - if edge e is not null and the sourceVertex parameter does not match the node U of the endpoint-pair

IllegalArgumentException - if edge e is not null and the targetVertex parameter does not match the node V of the endpoint-pair

See Also:

Graph.addEdge(Object, Object), Graph.getEdgeSupplier()

addVertex

public V addVertex()

Description copied from interface: Graph

Creates a new vertex in this graph and returns it.

This method creates the new vertex v using this graph's vertex supplier (see Graph.getVertexSupplier()). For the new vertex to be added v must not be equal to any other vertex in the graph. More formally, the graph must not contain any vertex v2 such that v2.equals(v). If such v2 is found then the newly created vertex v is abandoned, the method leaves this graph unchanged and throws an IllegalArgumentException.

If the underlying graph implementation's Graph.getVertexSupplier() returns null, then this method cannot create vertices and throws an UnsupportedOperationException.

Care must also be taken when interchanging calls to methods Graph.addVertex(Object) and Graph.addVertex(). In such a case the user must make sure never to add vertices in the graph using method Graph.addVertex(Object), which are going to be returned in the future by the supplied vertex supplier. Such a sequence will result into an IllegalArgumentException when calling method Graph.addVertex().

Specified by:

addVertex in interface Graph<V,com.google.common.graph.EndpointPair<V>>

Returns:

The newly created vertex if added to the graph.

See Also:

Graph.getVertexSupplier()

addVertex

public boolean addVertex(V v)

Description copied from interface: Graph

Adds the specified vertex to this graph if not already present. More formally, adds the specified vertex, v, to this graph if this graph contains no vertex u such that u.equals(v). If this graph already contains such vertex, the call leaves this graph unchanged and returns false. In combination with the restriction on constructors, this ensures that graphs never contain duplicate vertices.

Specified by:

addVertex in interface Graph<V,com.google.common.graph.EndpointPair<V>>

Parameters:

v - vertex to be added to this graph.

Returns:

true if this graph did not already contain the specified vertex.

removeEdge

public com.google.common.graph.EndpointPair<V> removeEdge(V sourceVertex,
                                                          V targetVertex)

Description copied from interface: Graph

Removes an edge going from source vertex to target vertex, if such vertices and such edge exist in this graph. Returns the edge if removed or null otherwise.

Specified by:

removeEdge in interface Graph<V,com.google.common.graph.EndpointPair<V>>

Parameters:

sourceVertex - source vertex of the edge.

targetVertex - target vertex of the edge.

Returns:

The removed edge, or null if no edge removed.

removeEdge

public boolean removeEdge(com.google.common.graph.EndpointPair<V> e)

Description copied from interface: Graph

Removes the specified edge from the graph. Removes the specified edge from this graph if it is present. More formally, removes an edge e2 such that e2.equals(e), if the graph contains such edge. Returns true if the graph contained the specified edge. (The graph will not contain the specified edge once the call returns).

If the specified edge is null returns false.

Specified by:

removeEdge in interface Graph<V,com.google.common.graph.EndpointPair<V>>

Parameters:

e - edge to be removed from this graph, if present.

Returns:

true if and only if the graph contained the specified edge.

removeVertex

public boolean removeVertex(V v)

Description copied from interface: Graph

Removes the specified vertex from this graph including all its touching edges if present. More formally, if the graph contains a vertex u such that u.equals(v), the call removes all edges that touch u and then removes u itself. If no such u is found, the call leaves the graph unchanged. Returns true if the graph contained the specified vertex. (The graph will not contain the specified vertex once the call returns).

If the specified vertex is null returns false.

Specified by:

removeVertex in interface Graph<V,com.google.common.graph.EndpointPair<V>>

Parameters:

v - vertex to be removed from this graph, if present.

Returns:

true if the graph contained the specified vertex; false otherwise.

setEdgeWeight

public void setEdgeWeight(com.google.common.graph.EndpointPair<V> e,
                          double weight)

Assigns a weight to an edge. This method always throws an UnsupportedOperationException since the adapter works one-way from values to weights. Adjusting the weights can be done by adjusting the values in the underlying ValueGraph which will automatically be propagated using the provided converter.

Specified by:

setEdgeWeight in interface Graph<V,com.google.common.graph.EndpointPair<V>>

Parameters:

e - edge on which to set weight

weight - new weight for edge

Throws:

UnsupportedOperationException - if the graph does not support weights

clone

public Object clone()

Returns a shallow copy of this graph instance. Neither edges nor vertices are cloned.

Overrides:

clone in class Object

Returns:

a shallow copy of this graph.

Throws:

RuntimeException - in case the clone is not supported

See Also:

Object.clone()