Package org.apache.tinkerpop.gremlin.process.computer.clustering.connected

Class ConnectedComponentVertexProgram

java.lang.Object
org.apache.tinkerpop.gremlin.process.computer.clustering.connected.ConnectedComponentVertexProgram
All Implemented Interfaces:
Cloneable, VertexProgram<String>
public class ConnectedComponentVertexProgram extends Object implements VertexProgram<String>
Identifies "Connected Component" instances in a graph by assigning a component identifier (the lexicographically least string value of the vertex in the component) to each vertex.
Author:
Stephen Mallette (http://stephen.genoprime.com), Daniel Kuppitz (http://gremlin.guru)

  • Field Details

  • Method Details

    • loadState

      public void loadState(Graph graph, org.apache.commons.configuration2.Configuration config)
      Description copied from interface: VertexProgram
      When it is necessary to load the state of the VertexProgram, this method is called. This is typically required when the VertexProgram needs to be serialized to another machine. Note that what is loaded is simply the instance state, not any processed data.
      Specified by:
      loadState in interface VertexProgram<String>
      Parameters:
      graph - the graph that the VertexProgram will run against
      config - the configuration to load the state of the VertexProgram from.

    • storeState

      public void storeState(org.apache.commons.configuration2.Configuration config)
      Description copied from interface: VertexProgram
      When it is necessary to store the state of the VertexProgram, this method is called. This is typically required when the VertexProgram needs to be serialized to another machine. Note that what is stored is simply the instance/configuration state, not any processed data. The default implementation provided simply stores the VertexProgram class name for reflective reconstruction. It is typically a good idea to VertexProgram.super.storeState().
      Specified by:
      storeState in interface VertexProgram<String>
      Parameters:
      config - the configuration to store the state of the VertexProgram in.

    • setup

      public void setup(Memory memory)
      Description copied from interface: VertexProgram
      The method is called at the beginning of the computation. The method is global to the GraphComputer and as such, is not called for each vertex. During this stage, the Memory should be initialized to to its "start state."
      Specified by:
      setup in interface VertexProgram<String>
      Parameters:
      memory - The global memory of the GraphComputer

    • execute

      public void execute(Vertex vertex, Messenger<String> messenger, Memory memory)
      Description copied from interface: VertexProgram
      This method denotes the main body of the computation and is executed on each vertex in the graph. This method is logically executed in parallel on all vertices in the graph. When the Memory is read, it is according to the aggregated state yielded in the previous iteration. When the Memory is written, the data will be aggregated at the end of the iteration for reading in the next iteration.
      Specified by:
      execute in interface VertexProgram<String>
      Parameters:
      vertex - the Vertex to execute the VertexProgram on
      messenger - the messenger that moves data between vertices
      memory - the shared state between all vertices in the computation

    • getVertexComputeKeys

      public Set<VertexComputeKey> getVertexComputeKeys()
      Description copied from interface: VertexProgram
      The Element properties that will be mutated during the computation. All properties in the graph are readable, but only the keys specified here are writable. The default is an empty set.
      Specified by:
      getVertexComputeKeys in interface VertexProgram<String>
      Returns:
      the set of element keys that will be mutated during the vertex program's execution

    • getMemoryComputeKeys

      public Set<MemoryComputeKey> getMemoryComputeKeys()
      Description copied from interface: VertexProgram
      The Memory keys that will be used during the computation. These are the only keys that can be read or written throughout the life of the GraphComputer. The default is an empty set.
      Specified by:
      getMemoryComputeKeys in interface VertexProgram<String>
      Returns:
      the set of memory keys that will be read/written

    • terminate

      public boolean terminate(Memory memory)
      Description copied from interface: VertexProgram
      The method is called at the end of each iteration to determine if the computation is complete. The method is global to the GraphComputer and as such, is not called for each Vertex. The Memory maintains the aggregated data from the last execute() iteration.
      Specified by:
      terminate in interface VertexProgram<String>
      Parameters:
      memory - The global memory of the GraphComputer
      Returns:
      whether or not to halt the computation

    • getMessageScopes

      public Set<MessageScope> getMessageScopes(Memory memory)
      Description copied from interface: VertexProgram
      This method returns all the MessageScope possibilities for a particular iteration of the vertex program. The returned messages scopes are the scopes that will be used to send messages during the stated iteration. It is not a requirement that all stated messages scopes be used, just that it is possible that they be used during the iteration.
      Specified by:
      getMessageScopes in interface VertexProgram<String>
      Parameters:
      memory - an immutable form of the Memory
      Returns:
      all possible message scopes during said vertex program iteration

    • getPreferredResultGraph

      public GraphComputer.ResultGraph getPreferredResultGraph()
      Specified by:
      getPreferredResultGraph in interface VertexProgram<String>

    • getPreferredPersist

      public GraphComputer.Persist getPreferredPersist()
      Specified by:
      getPreferredPersist in interface VertexProgram<String>

    • clone

      public ConnectedComponentVertexProgram clone()
      Description copied from interface: VertexProgram
      When multiple workers on a single machine need VertexProgram instances, it is possible to use clone. This will provide a speedier way of generating instances, over the VertexProgram.storeState(org.apache.commons.configuration2.Configuration) and VertexProgram.loadState(org.apache.tinkerpop.gremlin.structure.Graph, org.apache.commons.configuration2.Configuration) model. The default implementation simply returns the object as it assumes that the VertexProgram instance is a stateless singleton.
      Specified by:
      clone in interface VertexProgram<String>
      Overrides:
      clone in class Object
      Returns:
      A clone of the VertexProgram object

    • getFeatures

      public VertexProgram.Features getFeatures()
      Specified by:
      getFeatures in interface VertexProgram<String>

    • build

      public static ConnectedComponentVertexProgram.Builder build()