Package org.jgrapht.graph.specifics

Class FastLookupUndirectedSpecifics<V,​E>

  • Type Parameters:
    V - the graph vertex type
    E - the graph edge type
    All Implemented Interfaces:
    java.io.Serializable, Specifics<V,​E>
    public class FastLookupUndirectedSpecifics<V,​E>
extends UndirectedSpecifics<V,​E>
    Fast implementation of UndirectedSpecifics. This class uses additional data structures to improve the performance of methods which depend on edge retrievals, e.g. getEdge(V u, V v), containsEdge(V u, V v), addEdge(V u, V v). A disadvantage is an increase in memory consumption. If memory utilization is an issue, use a UndirectedSpecifics instead.
    Author:
    Joris Kinable
    See Also:
    Serialized Form

    • Field Detail

      • touchingVerticesToEdgeMap

        protected java.util.Map<Pair<V,​V>,​java.util.Set<E>> touchingVerticesToEdgeMap
        Maps a pair of vertices <u,v> to a set of edges {(u,v)}. In case of a multigraph, all edges which touch both u and v are included in the set.

    • Constructor Detail

      • FastLookupUndirectedSpecifics

        public FastLookupUndirectedSpecifics​(Graph<V,​E> graph,
                                     java.util.Map<V,​UndirectedEdgeContainer<V,​E>> vertexMap,
                                     java.util.Map<Pair<V,​V>,​java.util.Set<E>> touchingVerticesToEdgeMap,
                                     EdgeSetFactory<V,​E> edgeSetFactory)
        Construct a new fast lookup undirected specifics.
        Parameters:
        graph - the graph for which these specifics are for
        vertexMap - map for the storage of vertex edge sets. Needs to have a predictable iteration order.
        touchingVerticesToEdgeMap - Additional map for caching. No need for a predictable iteration order.
        edgeSetFactory - factory for the creation of vertex edge sets

    • Method Detail

      • getAllEdges

        public java.util.Set<E> getAllEdges​(V sourceVertex,
                                    V targetVertex)
        Description copied from class: UndirectedSpecifics
        Returns a set of all edges connecting source vertex to target vertex if such vertices exist in this graph. If any of the vertices does not exist or is null, returns null. If both vertices exist but no edges found, returns an empty set.
        Specified by:
        getAllEdges in interface Specifics<V,​E>
        Overrides:
        getAllEdges in class UndirectedSpecifics<V,​E>
        Parameters:
        sourceVertex - source vertex of the edge.
        targetVertex - target vertex of the edge.
        Returns:
        a set of all edges connecting source vertex to target vertex.

      • getEdge

        public E getEdge​(V sourceVertex,
                 V targetVertex)
        Description copied from class: UndirectedSpecifics
        Returns an edge connecting source vertex to target vertex if such vertices and such edge exist in this graph. Otherwise returns null. If any of the specified vertices is null returns null

        In undirected graphs, the returned edge may have its source and target vertices in the opposite order.

        Specified by:
        getEdge in interface Specifics<V,​E>
        Overrides:
        getEdge in class UndirectedSpecifics<V,​E>
        Parameters:
        sourceVertex - source vertex of the edge.
        targetVertex - target vertex of the edge.
        Returns:
        an edge connecting source vertex to target vertex.

      • addEdgeToTouchingVertices

        public boolean addEdgeToTouchingVertices​(V sourceVertex,
                                         V targetVertex,
                                         E e)
        Description copied from interface: Specifics
        Adds the specified edge to the edge containers of its source and target vertices.
        Specified by:
        addEdgeToTouchingVertices in interface Specifics<V,​E>
        Overrides:
        addEdgeToTouchingVertices in class UndirectedSpecifics<V,​E>
        Parameters:
        sourceVertex - the source vertex
        targetVertex - the target vertex
        e - the edge
        Returns:
        true if the edge was added, false otherwise

      • addEdgeToTouchingVerticesIfAbsent

        public boolean addEdgeToTouchingVerticesIfAbsent​(V sourceVertex,
                                                 V targetVertex,
                                                 E e)
        Description copied from interface: Specifics
        Adds the specified edge to the edge containers of its source and target vertices only if the edge is not already in the graph.
        Specified by:
        addEdgeToTouchingVerticesIfAbsent in interface Specifics<V,​E>
        Overrides:
        addEdgeToTouchingVerticesIfAbsent in class UndirectedSpecifics<V,​E>
        Parameters:
        sourceVertex - the source vertex
        targetVertex - the target vertex
        e - the edge
        Returns:
        true if the edge was added, false otherwise

      • createEdgeToTouchingVerticesIfAbsent

        public E createEdgeToTouchingVerticesIfAbsent​(V sourceVertex,
                                              V targetVertex,
                                              java.util.function.Supplier<E> edgeSupplier)
        Description copied from interface: Specifics
        Creates an edge given an edge supplier and adds it to the edge containers of its source and target vertices only if the graph does not contain other edges with the same source and target vertices.
        Specified by:
        createEdgeToTouchingVerticesIfAbsent in interface Specifics<V,​E>
        Overrides:
        createEdgeToTouchingVerticesIfAbsent in class UndirectedSpecifics<V,​E>
        Parameters:
        sourceVertex - the source vertex
        targetVertex - the target vertex
        edgeSupplier - the function which will create the edge
        Returns:
        the newly created edge or null if an edge with the same source and target vertices was already present

      • addToIndex

        protected void addToIndex​(V sourceVertex,
                          V targetVertex,
                          E e)
        Add an edge to the index.
        Parameters:
        sourceVertex - the source vertex
        targetVertex - the target vertex
        e - the edge

      • removeFromIndex

        protected void removeFromIndex​(V sourceVertex,
                               V targetVertex,
                               E e)
        Remove an edge from the index.
        Parameters:
        sourceVertex - the source vertex
        targetVertex - the target vertex
        e - the edge