Class SinglePairShortestPathBFS

java.lang.Object
com.sparsity.sparksee.algorithms.ShortestPath
com.sparsity.sparksee.algorithms.SinglePairShortestPath
com.sparsity.sparksee.algorithms.SinglePairShortestPathBFS
All Implemented Interfaces:
Closeable, AutoCloseable
public class SinglePairShortestPathBFS extends SinglePairShortestPath
SinglePairShortestPathBFS class.

It solves the single-pair shortest path problem using a BFS-based implementation.

It is a unweighted algorithm, that is it assumes all edges have the same cost.

Check out the 'Algorithms' section in the SPARKSEE User Manual for more details on this.

Author:
Sparsity Technologies http://www.sparsity-technologies.com

  • Constructor Details

    • SinglePairShortestPathBFS

      public SinglePairShortestPathBFS(Session session, long src, long dst)
      Creates a new instance.

      Parameters:
      session - [in] Session to get the graph from and perform traversal.
      src - [in] Source node.
      dst - [dst] Destination node.

  • Method Details

    • excludeNodes

      public void excludeNodes(Objects nodes)
      Set which nodes can't be used.

      This will replace any previously specified set of excluded nodes. Should only be used to exclude the usage of specific nodes from allowed node types because it's less efficient than not allowing a node type.

      Overrides:
      excludeNodes in class SinglePairShortestPath
      Parameters:
      nodes - [in] A set of node identifiers that must be kept intact until the destruction of the class.

    • getCost

      public double getCost()
      Gets the cost of the shortest path.

      The cost is the number of hops of the shortest path.

      Overrides:
      getCost in class SinglePairShortestPath
      Returns:
      The cost of the shortest path.

    • run

      public void run()
      Executes the algorithm.

      Overrides:
      run in class SinglePairShortestPath

    • addAllEdgeTypes

      public void addAllEdgeTypes(EdgesDirection dir)
      Allows for traversing all edge types of the graph.

      Overrides:
      addAllEdgeTypes in class SinglePairShortestPath
      Parameters:
      dir - [in] Edge direction.

    • excludeEdges

      public void excludeEdges(Objects edges)
      Set which edges can't be used.

      This will replace any previously specified set of excluded edges. Should only be used to exclude the usage of specific edges from allowed edge types because it's less efficient than not allowing an edge type.

      Overrides:
      excludeEdges in class SinglePairShortestPath
      Parameters:
      edges - [in] A set of edge identifiers that must be kept intact until the destruction of the class.

    • addEdgeType

      public void addEdgeType(int type, EdgesDirection dir)
      Allows for traversing edges of the given type.

      Overrides:
      addEdgeType in class SinglePairShortestPath
      Parameters:
      type - [in] Edge type.
      dir - [in] Edge direction.

    • getPathAsNodes

      public OIDList getPathAsNodes()
      Gets the shortest path between the source node and the destination node as an ordered set of nodes.

      Overrides:
      getPathAsNodes in class SinglePairShortestPath
      Returns:
      Ordered set of node identifiers.

    • addNodeType

      public void addNodeType(int type)
      Allows for traversing nodes of the given type.

      Overrides:
      addNodeType in class SinglePairShortestPath
      Parameters:
      type - null

    • exists

      public boolean exists()
      Returns TRUE If a path exists or FALSE otherwise.

      Overrides:
      exists in class SinglePairShortestPath

    • checkOnlyExistence

      public void checkOnlyExistence()
      Set that only the path existence must be calculated and not the path itself.

      That method should improve the performance of the algorithm, but a call to GetPathAsNodes or GetPathAsEdges will generate an exception even if the path exists.

    • getPathAsEdges

      public OIDList getPathAsEdges()
      Gets the shortest path between the source node and the destination node as an ordered set of edges.

      Overrides:
      getPathAsEdges in class SinglePairShortestPath
      Returns:
      Ordered set of edge identifiers.

    • setMaximumHops

      public void setMaximumHops(int maxhops)
      Sets the maximum hops restriction.

      All paths longer than the maximum hops restriction will be ignored.

      Overrides:
      setMaximumHops in class SinglePairShortestPath
      Parameters:
      maxhops - [in] The maximum hops restriction. It must be positive or zero. Zero, the default value, means unlimited.

    • addAllNodeTypes

      public void addAllNodeTypes()
      Allows for traversing all node types of the graph.

      Overrides:
      addAllNodeTypes in class SinglePairShortestPath