Class TupleFunctionFederatedService

java.lang.Object
org.eclipse.rdf4j.query.algebra.evaluation.federation.TupleFunctionFederatedService
All Implemented Interfaces:
FederatedService

public class TupleFunctionFederatedService extends Object implements FederatedService
A federated service that can evaluate TupleFunctions.
  • Constructor Details

  • Method Details

    • isInitialized

      public boolean isInitialized()
      Description copied from interface: FederatedService
      Method to check if FederatedService.initialize() had been called.
      Specified by:
      isInitialized in interface FederatedService
    • initialize

      public void initialize()
      Description copied from interface: FederatedService
      Method to perform any initializations, invoked after construction.
      Specified by:
      initialize in interface FederatedService
    • shutdown

      public void shutdown()
      Description copied from interface: FederatedService
      Method to perform any shutDown code, invoked at unregistering.
      Specified by:
      shutdown in interface FederatedService
    • ask

      public boolean ask(Service service, BindingSet bindings, String baseUri) throws QueryEvaluationException
      Description copied from interface: FederatedService

      Evaluate the provided SPARQL ASK query at this federated service.

       Expected behavior: evaluate boolean query using the bindings as constraints
       
      Specified by:
      ask in interface FederatedService
      Parameters:
      service - the reference to the service node, contains additional meta information (vars, prefixes)
      bindings - the bindings serving as additional constraints
      baseUri -
      Returns:
      true if at least one result exists
      Throws:
      QueryEvaluationException - If there was an exception generated while evaluating the query.
    • select

      public CloseableIteration<BindingSet,QueryEvaluationException> select(Service service, Set<String> projectionVars, BindingSet bindings, String baseUri) throws QueryEvaluationException
      Description copied from interface: FederatedService

      Evaluate the provided SPARQL query at this federated service.

      Important: The original bindings need to be inserted into the result.

       Expected behavior: evaluate the given SPARQL query using the bindings as constraints
       
      Specified by:
      select in interface FederatedService
      Parameters:
      service - the reference to the service node, contains additional meta information (vars, prefixes)
      projectionVars - The variables with unknown value that should be projected from this evaluation
      bindings - the bindings serving as additional constraints
      baseUri -
      Returns:
      an iteration over the results of the query
      Throws:
      QueryEvaluationException - If there was an exception generated while evaluating the query.
    • evaluate

      Description copied from interface: FederatedService
      Evaluate the provided SPARQL query at this federated service, possibilities for vectored evaluation.

      Contracts:

      • The original bindings need to be inserted into the result
      • SILENT service must be dealt with in the method

      Compare SPARQLFederatedService for a reference implementation

      Specified by:
      evaluate in interface FederatedService
      Parameters:
      service - the reference to the service node, contains information to construct the query
      bindings - the bindings serving as additional constraints (for vectored evaluation)
      baseUri - the baseUri
      Returns:
      the result of evaluating the query using bindings as constraints, the original bindings need to be inserted into the results!
      Throws:
      QueryEvaluationException - If there was an exception generated while evaluating the query.