public class DirectedAcyclicGraph<V,E> extends SimpleDirectedGraph<V,E>
DirectedAcyclicGraph implements a DAG that can be modified (vertices & edges added and removed), is guaranteed to remain acyclic, and provides fast topological order iteration.
This is done using a dynamic topological sort which is based on the algorithm PK described in "D. Pearce & P. Kelly, 2007: A Dynamic Topological Sort Algorithm for Directed Acyclic Graphs", (see Paper or ACM link for details).
The implementation differs from the algorithm specified in the above paper in some ways, perhaps most notably in that the topological ordering is stored by default using two HashMaps, which will have some effects on runtime, but also allows for vertex addition and removal, and other operations which are helpful for manipulating or combining DAGs. This storage mechanism is pluggable for subclassers.
This class makes no claims to thread safety, and concurrent usage from multiple threads will produce undefined results.
| Modifier and Type | Class and Description |
|---|---|
static class |
DirectedAcyclicGraph.CycleFoundException
Exception used in dfsF when a cycle is found
|
static class |
DirectedAcyclicGraph.Region
Region is an *inclusive* range of indices.
|
static interface |
DirectedAcyclicGraph.TopoOrderMapping<V>
For performance tuning, an interface for storing the topological ordering
|
static interface |
DirectedAcyclicGraph.TopoOrderMappingFactory<V> |
class |
DirectedAcyclicGraph.TopoVertexMap
For performance and flexibility uses an ArrayList for topological index
to vertex mapping, and a HashMap for vertex to topological index mapping.
|
static interface |
DirectedAcyclicGraph.Visited
this interface allows specification of a strategy for marking vertices as
visited (based on their topological index, so the vertex type isn't part
of the interface).
|
static class |
DirectedAcyclicGraph.VisitedArrayImpl
This implementation, somewhat to my surprise, is slower than the
ArrayList version, probably due to its reallocation of the underlying
array for every topology reorder that is required.
|
static class |
DirectedAcyclicGraph.VisitedArrayListImpl
This implementation seems to offer the best performance in most cases.
|
static class |
DirectedAcyclicGraph.VisitedBitSetImpl
This implementation is close to the performance of VisitedArrayListImpl,
with 1/8 the memory usage.
|
static interface |
DirectedAcyclicGraph.VisitedFactory
interface for a factory that vends Visited implementations
|
static class |
DirectedAcyclicGraph.VisitedHashSetImpl
This implementation doesn't seem to perform as well, though I can imagine
circumstances where it should shine (lots and lots of vertices).
|
| Constructor and Description |
|---|
DirectedAcyclicGraph(Class<? extends E> arg0) |
| Modifier and Type | Method and Description |
|---|---|
E |
addDagEdge(V fromVertex,
V toVertex)
Adds the given edge and updates the internal topological order for
consistency IFF
there is not already an edge (fromVertex, toVertex) in the graph
the edge does not induce a cycle in the graph
|
boolean |
addDagEdge(V fromVertex,
V toVertex,
E e)
Adds the given edge and updates the internal topological order for
consistency IFF
the given edge is not already a member of the graph
there is not already an edge (fromVertex, toVertex) in the graph
the edge does not induce a cycle in the graph
|
E |
addEdge(V sourceVertex,
V targetVertex)
identical to
addDagEdge(Object, Object), except an unchecked
IllegalArgumentException is thrown if a cycle would have been
induced by this edge |
boolean |
addEdge(V sourceVertex,
V targetVertex,
E edge)
identical to
addDagEdge(Object, Object, Object), except an
unchecked IllegalArgumentException is thrown if a cycle would
have been induced by this edge |
boolean |
addVertex(V v)
adds the vertex if it wasn't already in the graph, and puts it at the top
of the internal topological vertex ordering
|
boolean |
addVertex(V v,
boolean addToTop)
adds the vertex if it wasn't already in the graph, and puts it either at
the top or the bottom of the topological ordering, depending on the value
of addToTop.
|
Iterator<V> |
iterator()
iterator will traverse the vertices in topological order, meaning that
for a directed graph G = (V,E), if there exists a path from vertex va to
vertex vb then va is guaranteed to come before vertex vb in the iteration
order.
|
boolean |
removeAllVertices(Collection<? extends V> arg0)
Removes all the vertices in this graph that are also contained in the
specified vertex collection.
|
boolean |
removeVertex(V v)
Removes the specified vertex from this graph including all its touching
edges if present.
|
clone, containsEdge, containsVertex, degreeOf, edgeSet, edgesOf, getAllEdges, getEdge, getEdgeFactory, getEdgeSource, getEdgeTarget, getEdgeWeight, incomingEdgesOf, inDegreeOf, isAllowingLoops, isAllowingMultipleEdges, outDegreeOf, outgoingEdgesOf, removeEdge, removeEdge, setEdgeSetFactory, setEdgeWeight, vertexSetassertVertexExist, containsEdge, equals, hashCode, removeAllEdges, removeAllEdges, removeAllEdges, toString, toStringFromSetsfinalize, getClass, notify, notifyAll, wait, wait, waitincomingEdgesOf, inDegreeOf, outDegreeOf, outgoingEdgesOfcontainsEdge, containsEdge, containsVertex, edgeSet, edgesOf, getAllEdges, getEdge, getEdgeFactory, getEdgeSource, getEdgeTarget, getEdgeWeight, removeAllEdges, removeAllEdges, removeEdge, removeEdge, vertexSetpublic Iterator<V> iterator()
public boolean addVertex(V v)
addVertex in interface Graph<V,E>addVertex in class AbstractBaseGraph<V,E>v - vertex to be added to this graph.Graph.addVertex(Object)public boolean addVertex(V v, boolean addToTop)
v - addToTop - public E addDagEdge(V fromVertex, V toVertex) throws DirectedAcyclicGraph.CycleFoundException
Adds the given edge and updates the internal topological order for consistency IFF
IllegalArgumentException - If either fromVertex or toVertex is not
a member of the graphDirectedAcyclicGraph.CycleFoundException - if the edge would induce a cycle in the graphGraph.addEdge(Object, Object, Object)public E addEdge(V sourceVertex, V targetVertex)
addDagEdge(Object, Object), except an unchecked
IllegalArgumentException is thrown if a cycle would have been
induced by this edgeaddEdge in interface Graph<V,E>addEdge in class AbstractBaseGraph<V,E>sourceVertex - source vertex of the edge.targetVertex - target vertex of the edge.
null.Graph.addEdge(Object, Object)public boolean addDagEdge(V fromVertex, V toVertex, E e) throws DirectedAcyclicGraph.CycleFoundException
Adds the given edge and updates the internal topological order for consistency IFF
DirectedAcyclicGraph.CycleFoundException - if adding an edge (fromVertex, toVertex) to
the graph would induce a cycle.Graph.addEdge(Object, Object, Object)public boolean addEdge(V sourceVertex, V targetVertex, E edge)
addDagEdge(Object, Object, Object), except an
unchecked IllegalArgumentException is thrown if a cycle would
have been induced by this edgeaddEdge in interface Graph<V,E>addEdge in class AbstractBaseGraph<V,E>sourceVertex - source vertex of the edge.targetVertex - target vertex of the edge.edge - edge to be added to this graph.Graph.addEdge(Object, Object, Object)public boolean removeVertex(V v)
Graph
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.
removeVertex in interface Graph<V,E>removeVertex in class AbstractBaseGraph<V,E>v - vertex to be removed from this graph, if present.true if the graph contained the specified vertex;
false otherwise.Graph.removeVertex(Object)public boolean removeAllVertices(Collection<? extends V> arg0)
GraphGraph.removeVertex(Object) method.removeAllVertices in interface Graph<V,E>removeAllVertices in class AbstractGraph<V,E>arg0 - vertices to be removed from this graph.Graph.removeAllVertices(Collection)Copyright © 2013. All Rights Reserved.