Package com.jgalgo.graph

Interface GraphFactory<V,​E>

  • Type Parameters:
    V - the vertices type
    E - the edges type
    All Known Subinterfaces:
    IndexGraphFactory, IntGraphFactory
    public interface GraphFactory<V,​E>
    A factory for Graph objects.

    The factory can be used to create new empty graphs, with different options and capabilities. Few methods are available to optimize the graph implementation choice. The factory can also be used to create a copy of an existing graphs, with the same vertices and edges, with/without copying the vertices/edges weights.

    Both the graph factory and GraphBuilder are used to create new graphs. The difference is that vertices and edges can be added to the builder, which is then used to construct non empty graphs, while the factory is only used to choose a graph implementation and create an empty graph.

    Author:
    Barak Ugav
    See Also:
    newDirected(), newUndirected(), Graph, GraphBuilder

    • Method Detail

      • newGraph

        Graph<V,​E> newGraph()
        Create a new empty graph.
        Returns:
        a new graph with the factory options

      • newCopyOf

        default Graph<V,​E> newCopyOf​(Graph<V,​E> g)
        Create a copy of a given graph, with the same vertices and edges, without copying weights.

        An identical copy of the given graph will be created, with the same vertices and edges, without copying the vertices/edges weights. The returned Graph will always be modifiable, with no side affects on the original graph.

        Differing from Graph.copy(), the capabilities of the new graph are determined by the factory configuration, rather than copied from the given graph. Note for example that if the factory chooses to use an implementation that does not (have to) support self edges (if allowSelfEdges(boolean) was not called with true), attempting to create a copy of a graph that does contains self edges will result in an exception.

        Parameters:
        g - the original graph to copy
        Returns:
        an identical copy of the given graph, with the same vertices and edges, without the original graph weights

      • newCopyOf

        Graph<V,​E> newCopyOf​(Graph<V,​E> g,
                           boolean copyWeights)
        Create a copy of a given graph, with the same vertices and edges, with/without copying weights.

        An identical copy of the given graph will be created, with the same vertices and edges, with/without copying the vertices/edges weights. The returned Graph will always be modifiable, with no side affects on the original graph.

        Differing from Graph.copy(boolean), the capabilities of the new graph are determined by the factory configuration, rather than copied from the given graph. Note for example that if the factory chooses to use an implementation that does not (have to) support self edges (if allowSelfEdges(boolean) was not called with true), attempting to create a copy of a graph that does contains self edges will result in an exception.

        Parameters:
        g - the original graph to copy
        copyWeights - if true, the weights of the vertices and edges will be copied to the new graph
        Returns:
        an identical copy of the given graph, with the same vertices and edges, with/without the original graph weights

      • newBuilder

        GraphBuilder<V,​E> newBuilder()
        Create a new graph builder with the factory parameters.

        The created builder can be used to add vertices and edges, and then build a (mutable or immutable) non empty graph, differing from the factory which only builds empty graphs. The capabilities such as un/directed, support of self edges, support of parallel edges, and hints such as expected number of vertices and edges, other hints, etc. are copied from the factory to the builder.

        Returns:
        a new graph builder with the factory parameters

      • setDirected

        GraphFactory<V,​E> setDirected​(boolean directed)
        Determine if graphs built by this factory should be directed or not.
        Parameters:
        directed - if true, graphs built by this factory will be directed
        Returns:
        this factory

      • allowSelfEdges

        GraphFactory<V,​E> allowSelfEdges​(boolean selfEdges)
        Determine if graphs built by this factory should be support self edges.
        Parameters:
        selfEdges - if true, graphs built by this factory will support self edges
        Returns:
        this factory

      • allowParallelEdges

        GraphFactory<V,​E> allowParallelEdges​(boolean parallelEdges)
        Determine if graphs built by this factory should be support parallel edges.
        Parameters:
        parallelEdges - if true, graphs built by this factory will support parallel edges
        Returns:
        this factory

      • expectedVerticesNum

        GraphFactory<V,​E> expectedVerticesNum​(int expectedVerticesNum)
        Set the expected number of vertices that will exist in the graph.
        Parameters:
        expectedVerticesNum - the expected number of vertices in the graph
        Returns:
        this factory

      • expectedEdgesNum

        GraphFactory<V,​E> expectedEdgesNum​(int expectedEdgesNum)
        Set the expected number of edges that will exist in the graph.
        Parameters:
        expectedEdgesNum - the expected number of edges in the graph
        Returns:
        this factory

      • addHint

        GraphFactory<V,​E> addHint​(GraphFactory.Hint hint)
        Add a hint to this factory.

        Hints do not change the behavior of the graphs built by this factory, by may affect performance.

        Parameters:
        hint - the hint to add
        Returns:
        this factory

      • removeHint

        GraphFactory<V,​E> removeHint​(GraphFactory.Hint hint)
        Remove a hint from this factory.

        Hints do not change the behavior of the graphs built by this factory, by may affect performance.

        Parameters:
        hint - the hint to remove
        Returns:
        this factory

      • newUndirected

        static <V,​E> GraphFactory<V,​E> newUndirected()
        Create an undirected graph factory.
        Type Parameters:
        V - the vertices type
        E - the edges type
        Returns:
        a new factory that can build undirected graphs

      • newDirected

        static <V,​E> GraphFactory<V,​E> newDirected()
        Create a directed graph factory.
        Type Parameters:
        V - the vertices type
        E - the edges type
        Returns:
        a new factory that can build directed graphs

      • newFrom

        static <V,​E> GraphFactory<V,​E> newFrom​(Graph<V,​E> g)
        Create a new graph factory based on a given implementation.

        The new factory will build graphs with the same capabilities (inclusive) as the given graph, possibly choosing to use a similar implementation. The factory will NOT copy the graph itself (the vertices, edges and weights), for such use case see Graph.copy() or newCopyOf(Graph).

        Type Parameters:
        V - the vertices type
        E - the edges type
        Parameters:
        g - a graph from which the factory should copy its capabilities (inclusive)
        Returns:
        a new graph factory that will create graphs with the same capabilities (inclusive) of the given graph

      • setOption

        default GraphFactory<V,​E> setOption​(String key,
                                          Object value)
        [TL;DR Don't call me!] Set an option.

        The builder might support different options to customize its implementation. These options never change the behavior of the algorithm, only its internal implementation. The possible options are not exposed as 'public' because they are not part of the API and may change in the future.

        These options are mainly for debug and benchmark purposes.

        Parameters:
        key - the option key
        value - the option value
        Returns:
        this builder