Package org.eclipse.rdf4j.federated.evaluation.join

Class ParallelEmptyBindLeftJoinTask

java.lang.Object

org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelTaskBase<BindingSet>

org.eclipse.rdf4j.federated.evaluation.join.ParallelEmptyBindLeftJoinTask

All Implemented Interfaces:

ParallelTask<BindingSet>

public class ParallelEmptyBindLeftJoinTask
extends ParallelTaskBase<BindingSet>

A ParallelTaskBase for executing bind left joins, where the join argument is an EmptyStatementPattern. The effective result is that the input bindings from the left operand are passed through.

Author:

Andreas Schwarte

Field Summary

Fields

Modifier and Type	Field	Description
protected final List<BindingSet>	bindings
protected final ParallelExecutor<BindingSet>	joinControl
protected final EmptyStatementPattern	rightArg
protected final FederationEvalStrategy	strategy

Fields inherited from class org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelTaskBase

scheduledFuture

Constructor Summary

Constructors

Constructor	Description
ParallelEmptyBindLeftJoinTask(ParallelExecutor<BindingSet> joinControl, FederationEvalStrategy strategy, EmptyStatementPattern expr, List<BindingSet> bindings)

Method Summary

Modifier and Type	Method	Description
ParallelExecutor<BindingSet>	getControl()	return the controlling instance, e.g.
protected CloseableIteration<BindingSet>	performTaskInternal()

Methods inherited from class org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelTaskBase

cancel, close, performTask, setScheduledFuture, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelTask

getQueryInfo

Field Details

strategy

protected final FederationEvalStrategy strategy

rightArg

protected final EmptyStatementPattern rightArg

bindings

protected final List<BindingSet> bindings

joinControl

protected final ParallelExecutor<BindingSet> joinControl

Constructor Details

ParallelEmptyBindLeftJoinTask

public ParallelEmptyBindLeftJoinTask(ParallelExecutor<BindingSet> joinControl,
 FederationEvalStrategy strategy,
 EmptyStatementPattern expr,
 List<BindingSet> bindings)

Method Details

getControl

public ParallelExecutor<BindingSet> getControl()

Description copied from interface: ParallelTask

return the controlling instance, e.g. in most cases the instance of a thread. Shared variables are used to inform the thread about new events.

Returns:

the control executor

performTaskInternal

protected CloseableIteration<BindingSet> performTaskInternal()
                                                      throws Exception

Specified by:

performTaskInternal in class ParallelTaskBase<BindingSet>

Throws:

Exception