Package org.apache.tinkerpop.gremlin.structure.util.empty

Class EmptyGraph

java.lang.Object
org.apache.tinkerpop.gremlin.structure.util.empty.EmptyGraph
All Implemented Interfaces:
AutoCloseable, Graph, Host
public final class EmptyGraph extends Object implements Graph
Author:
Marko A. Rodriguez (http://markorodriguez.com), Stephen Mallette (http://stephen.genoprime.com)

  • Method Details

    • instance

      public static Graph instance()

    • features

      public Graph.Features features()
      Description copied from interface: Graph
      Gets the Graph.Features exposed by the underlying Graph implementation.
      Specified by:
      features in interface Graph

    • addVertex

      public Vertex addVertex(Object... keyValues)
      Description copied from interface: Graph
      Add a Vertex to the graph given an optional series of key/value pairs. These key/values must be provided in an even number where the odd numbered arguments are String property keys and the even numbered arguments are the related property values.
      Specified by:
      addVertex in interface Graph
      Parameters:
      keyValues - The key/value pairs to turn into vertex properties
      Returns:
      The newly created vertex

    • compute

      public <C extends GraphComputer> C compute(Class<C> graphComputerClass)
      Description copied from interface: Graph
      Declare the GraphComputer to use for OLAP operations on the graph. If the graph does not support graph computer then an UnsupportedOperationException is thrown.
      Specified by:
      compute in interface Graph
      Parameters:
      graphComputerClass - The graph computer class to use.
      Returns:
      A graph computer for processing this graph

    • compute

      public GraphComputer compute()
      Description copied from interface: Graph
      Generate a GraphComputer using the default engine of the underlying graph system. This is a shorthand method for the more involved method that uses Graph.compute(Class).
      Specified by:
      compute in interface Graph
      Returns:
      A default graph computer

    • tx

      public Transaction tx()
      Description copied from interface: Graph
      Configure and control the transactions for those graphs that support this feature.
      Specified by:
      tx in interface Graph

    • variables

      public Graph.Variables variables()
      Description copied from interface: Graph
      A collection of global Graph.Variables associated with the graph. Variables are used for storing metadata about the graph.
      Specified by:
      variables in interface Graph
      Returns:
      The variables associated with this graph

    • configuration

      public org.apache.commons.configuration2.Configuration configuration()
      Description copied from interface: Graph
      Get the Configuration associated with the construction of this graph. Whatever configuration was passed to GraphFactory.open(Configuration) is what should be returned by this method.
      Specified by:
      configuration in interface Graph
      Returns:
      the configuration used during graph construction.

    • close

      public void close() throws Exception
      Description copied from interface: Graph
      Closing a Graph is equivalent to "shutdown" and implies that no further operations can be executed on the instance. Users should consult the documentation of the underlying graph database implementation for what this "shutdown" will mean in general and, if supported, how open transactions are handled. It will typically be the end user's responsibility to synchronize the thread that calls close() with other threads that are accessing open transactions. In other words, be sure that all work performed on the Graph instance is complete prior to calling this method.

      TinkerPop does not enforce any particular semantics with respect to "shutdown". It is up to the graph provider to decide what this method will do.

      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Graph
      Throws:
      Exception

    • vertices

      public Iterator<Vertex> vertices(Object... vertexIds)
      Description copied from interface: Graph
      Get the Vertex objects in this graph with the provided vertex ids or Vertex objects themselves. If no ids are provided, get all vertices. Note that a vertex identifier does not need to correspond to the actual id used in the graph. It needs to be a bit more flexible than that in that given the Graph.Features around id support, multiple arguments might be applicable here.

      If the graph return true for Graph.Features.ElementFeatures.supportsNumericIds() then it should support filters as with:

      • g.vertices(v)
      • g.vertices(v.id())
      • g.vertices(1)
      • g.vertices(1L)
      • g.vertices(1.0d)
      • g.vertices(1.0f)
      • g.vertices("1")

      If the graph return true for Graph.Features.ElementFeatures.supportsCustomIds() ()} then it should support filters as with:

      • g.vertices(v)
      • g.vertices(v.id())
      • g.vertices(v.id().toString())

      If the graph return true for Graph.Features.ElementFeatures.supportsAnyIds() ()} then it should support filters as with:

      • g.vertices(v)
      • g.vertices(v.id())

        If the graph return true for Graph.Features.ElementFeatures.supportsStringIds() ()} then it should support filters as with:

      • g.vertices(v)
      • g.vertices(v.id().toString())
      • g.vertices("id")

      If the graph return true for Graph.Features.ElementFeatures.supportsStringIds() ()} then it should support filters as with:

      • g.vertices(v)
      • g.vertices(v.id().toString())
      • g.vertices("id")
      Specified by:
      vertices in interface Graph
      Parameters:
      vertexIds - the ids of the vertices to get
      Returns:
      an Iterator of vertices that match the provided vertex ids

    • edges

      public Iterator<Edge> edges(Object... edgeIds)
      Description copied from interface: Graph
      Get the Edge objects in this graph with the provided edge ids or Edge objects. If no ids are provided, get all edges. Note that an edge identifier does not need to correspond to the actual id used in the graph. It needs to be a bit more flexible than that in that given the Graph.Features around id support, multiple arguments might be applicable here.

      If the graph return true for Graph.Features.ElementFeatures.supportsNumericIds() then it should support filters as with:

      • g.edges(e)
      • g.edges(e.id())
      • g.edges(1)
      • g.edges(1L)
      • g.edges(1.0d)
      • g.edges(1.0f)
      • g.edges("1")

      If the graph return true for Graph.Features.ElementFeatures.supportsCustomIds() ()} then it should support filters as with:

      • g.edges(e)
      • g.edges(e.id())
      • g.edges(e.id().toString())

      If the graph return true for Graph.Features.ElementFeatures.supportsAnyIds() ()} then it should support filters as with:

      • g.edges(e)
      • g.edges(e.id())

      If the graph return true for Graph.Features.ElementFeatures.supportsStringIds() ()} then it should support filters as with:

      • g.edges(e)
      • g.edges(e.id().toString())
      • g.edges("id")
      Specified by:
      edges in interface Graph
      Parameters:
      edgeIds - the ids of the edges to get
      Returns:
      an Iterator of edges that match the provided edge ids

    • toString

      public String toString()
      Overrides:
      toString in class Object