Package org.eclipse.rdf4j.federated.evaluation.concurrent

Class ParallelServiceExecutor

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E,X>

org.eclipse.rdf4j.common.iteration.LookAheadIteration<BindingSet,QueryEvaluationException>

org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelServiceExecutor

All Implemented Interfaces:

AutoCloseable, Runnable, CloseableIteration<BindingSet,QueryEvaluationException>, Iteration<BindingSet,QueryEvaluationException>, ParallelExecutor<BindingSet>

public class ParallelServiceExecutor
extends LookAheadIteration<BindingSet,QueryEvaluationException>
implements ParallelExecutor<BindingSet>

Parallel executor for FedXService nodes, which wrap SERVICE expressions. Uses the union scheduler to execute the task

Author:

Andreas Schwarte

Field Summary

Fields

Modifier and Type	Field	Description
protected BindingSet	bindings
protected Exception	error
protected FederationContext	federationContext
protected boolean	finished
protected static org.slf4j.Logger	log
protected CloseableIteration<BindingSet,QueryEvaluationException>	rightIter
protected FedXService	service
protected FederationEvalStrategy	strategy

Constructor Summary

Constructors

Constructor	Description
ParallelServiceExecutor(FedXService service, FederationEvalStrategy strategy, BindingSet bindings, FederationContext federationContext)

Method Summary

Modifier and Type	Method	Description
void	addResult(CloseableIteration<BindingSet,QueryEvaluationException> res)	Handle the result appropriately, e.g.
void	done()	Inform the controlling instance that some job is done from a different thread.
protected BindingSet	getNextElement()	Gets the next element.
QueryInfo	getQueryInfo()	Return the query info of the associated query
boolean	isFinished()	Return true if this executor is finished or aborted
void	run()
void	toss(Exception e)	Toss some exception to the controlling instance

Methods inherited from class org.eclipse.rdf4j.common.iteration.LookAheadIteration

handleClose, hasNext, next, remove

Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration

close, isClosed

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.common.iteration.Iteration

stream

Field Details

log

protected static final org.slf4j.Logger log

service

protected final FedXService service

strategy

protected final FederationEvalStrategy strategy

bindings

protected final BindingSet bindings

federationContext

protected final FederationContext federationContext

rightIter

protected CloseableIteration<BindingSet,QueryEvaluationException> rightIter

finished

protected boolean finished

error

protected Exception error

Constructor Details

ParallelServiceExecutor

public ParallelServiceExecutor(FedXService service,
 FederationEvalStrategy strategy,
 BindingSet bindings,
 FederationContext federationContext)

Parameters:

service -

strategy -

bindings -

federationContext -

Method Details

run

public void run()

Specified by:

run in interface Runnable

addResult

public void addResult(CloseableIteration<BindingSet,QueryEvaluationException> res)

Description copied from interface: ParallelExecutor

Handle the result appropriately, e.g. add it to the result iteration. Take care for synchronization in a multithreaded environment

Specified by:

addResult in interface ParallelExecutor<BindingSet>

toss

public void toss(Exception e)

Description copied from interface: ParallelExecutor

Toss some exception to the controlling instance

Specified by:

toss in interface ParallelExecutor<BindingSet>

done

public void done()

Description copied from interface: ParallelExecutor

Inform the controlling instance that some job is done from a different thread. In most cases this is a no-op.

Specified by:

done in interface ParallelExecutor<BindingSet>

isFinished

public boolean isFinished()

Description copied from interface: ParallelExecutor

Return true if this executor is finished or aborted

Specified by:

isFinished in interface ParallelExecutor<BindingSet>

Returns:

whether the execution is finished

getQueryInfo

public QueryInfo getQueryInfo()

Description copied from interface: ParallelExecutor

Return the query info of the associated query

Specified by:

getQueryInfo in interface ParallelExecutor<BindingSet>

Returns:

the query info

getNextElement

protected BindingSet getNextElement()
                             throws QueryEvaluationException

Description copied from class: LookAheadIteration

Gets the next element. Subclasses should implement this method so that it returns the next element.

Specified by:

getNextElement in class LookAheadIteration<BindingSet,QueryEvaluationException>

Returns:

The next element, or null if no more elements are available.

Throws:

QueryEvaluationException