Module org.jgrapht.unimi.dsi
Package org.jgrapht.webgraph

Class AbstractImmutableGraphAdapter<E extends it.unimi.dsi.fastutil.ints.IntIntPair>

java.lang.Object
org.jgrapht.graph.AbstractGraph<Integer,E>
org.jgrapht.webgraph.AbstractImmutableGraphAdapter<E>
Type Parameters:
E - the type of an edge.
All Implemented Interfaces:
Graph<Integer,E>
Direct Known Subclasses:
ImmutableDirectedGraphAdapter, ImmutableUndirectedGraphAdapter
public abstract class AbstractImmutableGraphAdapter<E extends it.unimi.dsi.fastutil.ints.IntIntPair> extends AbstractGraph<Integer,E>
An abstract base class for adapters using WebGraph's ImmutableGraph. Nodes are instances of Integer corresponding to the index of a node in WebGraph.
Author:
Sebastiano Vigna

  • Field Details

    • immutableGraph

      protected final it.unimi.dsi.webgraph.ImmutableGraph immutableGraph
      The underlying graph.

    • n

      protected final int n
      The number of nodes of immutableGraph.

    • m

      protected long m
      The number of edges, cached, or -1 if it still unknown. This will have to be computed by enumeration for undirected graphs, as we do not know how many loops are present, and for graphs which do not support ImmutableGraph.numArcs().

  • Constructor Details

    • AbstractImmutableGraphAdapter

      protected AbstractImmutableGraphAdapter(it.unimi.dsi.webgraph.ImmutableGraph immutableGraph)

  • Method Details

    • getAllEdges

      public Set<E> getAllEdges(Integer sourceVertex, Integer targetVertex)
      Description copied from interface: Graph
      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.

      In undirected graphs, some of the returned edges may have their source and target vertices in the opposite order. In simple graphs the returned set is either singleton set or empty set.

      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.

    • makeEdge

      protected abstract E makeEdge(int x, int y)

    • getEdge

      public E getEdge(Integer sourceVertex, Integer targetVertex)
      Description copied from interface: Graph
      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.

      Parameters:
      sourceVertex - source vertex of the edge.
      targetVertex - target vertex of the edge.
      Returns:
      an edge connecting source vertex to target vertex.

    • getVertexSupplier

      public Supplier<Integer> getVertexSupplier()
      Description copied from interface: Graph
      Return the vertex supplier that the graph uses whenever it needs to create new vertices.

      A graph uses the vertex supplier to create new vertex objects whenever a user calls method Graph.addVertex(). Users can also create the vertex in user code and then use method Graph.addVertex(Object) to add the vertex.

      In contrast with the Supplier interface, the vertex supplier has the additional requirement that a new and distinct result is returned every time it is invoked. More specifically for a new vertex to be added in a graph 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).

      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().

      Returns:
      the vertex supplier or null if the graph has no such supplier

    • getEdgeSupplier

      public Supplier<E> getEdgeSupplier()
      Description copied from interface: Graph
      Return the edge supplier that the graph uses whenever it needs to create new edges.

      A graph uses the edge supplier to create new edge objects whenever a user calls method Graph.addEdge(Object, Object). Users can also create the edge in user code and then use method Graph.addEdge(Object, Object, Object) to add the edge.

      In contrast with the Supplier interface, the edge supplier has the additional requirement that a new and distinct result is returned every time it is invoked. More specifically for a new edge to be added in a graph e must not be equal to any other edge in the graph (even if the graph allows edge-multiplicity). More formally, the graph must not contain any edge e2 such that e2.equals(e).

      Returns:
      the edge supplier null if the graph has no such supplier

    • addEdge

      public E addEdge(Integer sourceVertex, Integer 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, then 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.

      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:

    • addEdge

      public boolean addEdge(Integer sourceVertex, Integer targetVertex, E e)
      Description copied from interface: Graph
      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, then 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.

      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.
      See Also:

    • addVertex

      public Integer 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().

      Returns:
      The newly created vertex if added to the graph.
      See Also:

    • addVertex

      public boolean addVertex(Integer 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.
      Parameters:
      v - vertex to be added to this graph.
      Returns:
      true if this graph did not already contain the specified vertex.

    • containsEdge

      public boolean containsEdge(Integer sourceVertex, Integer targetVertex)
      Description copied from interface: Graph
      Returns true if and only if this graph contains an edge going from the source vertex to the target vertex. In undirected graphs the same result is obtained when source and target are inverted. If any of the specified vertices does not exist in the graph, or if is null, returns false.
      Specified by:
      containsEdge in interface Graph<Integer,E extends it.unimi.dsi.fastutil.ints.IntIntPair>
      Overrides:
      containsEdge in class AbstractGraph<Integer,E extends it.unimi.dsi.fastutil.ints.IntIntPair>
      Parameters:
      sourceVertex - source vertex of the edge.
      targetVertex - target vertex of the edge.
      Returns:
      true if this graph contains the specified edge.
      See Also:

    • containsEdgeFast

      protected boolean containsEdgeFast(int x, int y)

    • containsVertex

      public boolean containsVertex(Integer v)
      Description copied from interface: Graph
      Returns true if this graph contains the specified vertex. More formally, returns true if and only if this graph contains a vertex u such that u.equals(v). If the specified vertex is null returns false.
      Parameters:
      v - vertex whose presence in this graph is to be tested.
      Returns:
      true if this graph contains the specified vertex.

    • removeEdge

      public E removeEdge(Integer sourceVertex, Integer 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.
      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(E 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.

      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(Integer 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.

      Parameters:
      v - vertex to be removed from this graph, if present.
      Returns:
      true if the graph contained the specified vertex; false otherwise.

    • vertexSet

      public Set<Integer> vertexSet()
      Description copied from interface: Graph
      Returns a set of the vertices contained in this graph. The set is backed by the graph, so changes to the graph are reflected in the set. If the graph is modified while an iteration over the set is in progress, the results of the iteration are undefined.

      The graph implementation may maintain a particular set ordering (e.g. via LinkedHashSet) for deterministic iteration, but this is not required. It is the responsibility of callers who rely on this behavior to only use graph implementations which support it.

      Returns:
      a set view of the vertices contained in this graph.

    • getEdgeSource

      public Integer getEdgeSource(E e)
      Description copied from interface: Graph
      Returns the source vertex of an edge. For an undirected graph, source and target are distinguishable designations (but without any mathematical meaning).
      Parameters:
      e - edge of interest
      Returns:
      source vertex

    • getEdgeTarget

      public Integer getEdgeTarget(E e)
      Description copied from interface: Graph
      Returns the target vertex of an edge. For an undirected graph, source and target are distinguishable designations (but without any mathematical meaning).
      Parameters:
      e - edge of interest
      Returns:
      target vertex

    • getEdgeWeight

      public double getEdgeWeight(E e)
      Description copied from interface: Graph
      Returns the weight assigned to a given edge. Unweighted graphs return 1.0 (as defined by Graph.DEFAULT_EDGE_WEIGHT), allowing weighted-graph algorithms to apply to them when meaningful.
      Parameters:
      e - edge of interest
      Returns:
      edge weight

    • setEdgeWeight

      public void setEdgeWeight(E e, double weight)
      Description copied from interface: Graph
      Assigns a weight to an edge.
      Parameters:
      e - edge on which to set weight
      weight - new weight for edge