Class TupleFunctionFederatedService
java.lang.Object
org.eclipse.rdf4j.query.algebra.evaluation.federation.TupleFunctionFederatedService
- All Implemented Interfaces:
FederatedService
A federated service that can evaluate
TupleFunctions.-
Constructor Summary
ConstructorsConstructorDescriptionTupleFunctionFederatedService(TupleFunctionRegistry tupleFunctionRegistry, ValueFactory vf) -
Method Summary
Modifier and TypeMethodDescriptionbooleanask(Service service, BindingSet bindings, String baseUri) Evaluate the provided SPARQL ASK query at this federated service.evaluate(Service service, CloseableIteration<BindingSet, QueryEvaluationException> bindings, String baseUri) Evaluate the provided SPARQL query at this federated service, possibilities for vectored evaluation.voidMethod to perform any initializations, invoked after construction.booleanMethod to check ifFederatedService.initialize()had been called.Evaluate the provided SPARQL query at this federated service.voidshutdown()Method to perform any shutDown code, invoked at unregistering.
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Constructor Details
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TupleFunctionFederatedService
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Method Details
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isInitialized
public boolean isInitialized()Description copied from interface:FederatedServiceMethod to check ifFederatedService.initialize()had been called.- Specified by:
isInitializedin interfaceFederatedService
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initialize
public void initialize()Description copied from interface:FederatedServiceMethod to perform any initializations, invoked after construction.- Specified by:
initializein interfaceFederatedService
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shutdown
public void shutdown()Description copied from interface:FederatedServiceMethod to perform any shutDown code, invoked at unregistering.- Specified by:
shutdownin interfaceFederatedService
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ask
public boolean ask(Service service, BindingSet bindings, String baseUri) throws QueryEvaluationException Description copied from interface:FederatedServiceEvaluate the provided SPARQL ASK query at this federated service.
Expected behavior: evaluate boolean query using the bindings as constraints
- Specified by:
askin interfaceFederatedService- Parameters:
service- the reference to the service node, contains additional meta information (vars, prefixes)bindings- the bindings serving as additional constraints- Returns:
trueif at least one result exists- Throws:
QueryEvaluationException- If there was an exception generated while evaluating the query.
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select
public CloseableIteration<BindingSet,QueryEvaluationException> select(Service service, Set<String> projectionVars, BindingSet bindings, String baseUri) throws QueryEvaluationException Description copied from interface:FederatedServiceEvaluate 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:
selectin interfaceFederatedService- 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 evaluationbindings- the bindings serving as additional constraints- Returns:
- an iteration over the results of the query
- Throws:
QueryEvaluationException- If there was an exception generated while evaluating the query.
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evaluate
public final CloseableIteration<BindingSet,QueryEvaluationException> evaluate(Service service, CloseableIteration<BindingSet, QueryEvaluationException> bindings, String baseUri) throws QueryEvaluationExceptionDescription copied from interface:FederatedServiceEvaluate 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
SPARQLFederatedServicefor a reference implementation- Specified by:
evaluatein interfaceFederatedService- Parameters:
service- the reference to the service node, contains information to construct the querybindings- 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.
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