org.openrdf.query.algebra.evaluation.federation
Class ServiceFallbackIteration

java.lang.Object
  info.aduna.iteration.CloseableIterationBase<E,X>
      info.aduna.iteration.LookAheadIteration<T,QueryEvaluationException>
          org.openrdf.query.algebra.evaluation.federation.JoinExecutorBase<BindingSet>
              org.openrdf.query.algebra.evaluation.federation.ServiceFallbackIteration

All Implemented Interfaces:

CloseableIteration<BindingSet,QueryEvaluationException>, Iteration<BindingSet,QueryEvaluationException>

public class ServiceFallbackIteration
extends JoinExecutorBase<BindingSet>

Fallback join handler, if the block join can not be performed, e.g. because the BINDINGS clause is not supported by the endpoint. Gets a materialized collection of bindings as input, and has to evaluate the join.

Author:

Andreas Schwarte

Field Summary

protected Collection<BindingSet>	bindings
protected FederatedService	federatedService
protected String	preparedQuery
protected Service	service

Fields inherited from class org.openrdf.query.algebra.evaluation.federation.JoinExecutorBase

closed, evaluationThread, finished, leftIter, NEXT_JOIN_ID, rightArg, rightIter, rightQueue

Constructor Summary

ServiceFallbackIteration(Service service, String preparedQuery, Collection<BindingSet> bindings, FederatedService federatedService)

Method Summary

protected void

handleBindings() Implementations must implement this method to handle bindings.

Methods inherited from class org.openrdf.query.algebra.evaluation.federation.JoinExecutorBase

addResult, done, getNextElement, handleClose, isFinished, run, toss

Methods inherited from class info.aduna.iteration.LookAheadIteration

hasNext, next, remove

Methods inherited from class info.aduna.iteration.CloseableIterationBase

close, isClosed

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

service

protected final Service service

preparedQuery

protected final String preparedQuery

federatedService

protected final FederatedService federatedService

bindings

protected final Collection<BindingSet> bindings

Constructor Detail

ServiceFallbackIteration

public ServiceFallbackIteration(Service service,
                                String preparedQuery,
                                Collection<BindingSet> bindings,
                                FederatedService federatedService)
                         throws QueryEvaluationException

Parameters:

leftIter -

rightArg -

bindings -

Throws:

QueryEvaluationException

Method Detail

handleBindings

protected void handleBindings()
                       throws Exception

Description copied from class: JoinExecutorBase

Implementations must implement this method to handle bindings. Use the following as a template while (!closed && leftIter.hasNext()) { // your code } and add results to rightQueue. Note that addResult() is implemented synchronized and thus thread safe. In case you can guarantee sequential access, it is also possible to directly access rightQueue

Specified by:

handleBindings in class JoinExecutorBase<BindingSet>

Throws:

Exception