Class ControlledWorkerBindJoinBase
- java.lang.Object
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- org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E>
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- org.eclipse.rdf4j.common.iteration.LookAheadIteration<T>
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- org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelExecutorBase<T>
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- org.eclipse.rdf4j.federated.evaluation.join.JoinExecutorBase<BindingSet>
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- org.eclipse.rdf4j.federated.evaluation.join.ControlledWorkerBindJoinBase
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- All Implemented Interfaces:
AutoCloseable
,Runnable
,Iterator<BindingSet>
,CloseableIteration<BindingSet>
,ParallelExecutor<BindingSet>
- Direct Known Subclasses:
ControlledWorkerBindJoin
,ControlledWorkerBindLeftJoin
public abstract class ControlledWorkerBindJoinBase extends JoinExecutorBase<BindingSet>
Base class for executing joins as bind joins (i.e., the bindings of a block are injected in the SPARQL query as VALUES clause). The number of concurrent threads is controlled by aControlledWorkerScheduler
which works according to the FIFO principle and uses worker threads. This join cursor blocks until all scheduled tasks are finished, however the result iteration can be accessed from different threads to allow for pipelining.- Author:
- Andreas Schwarte
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Nested Class Summary
Nested Classes Modifier and Type Class Description protected static interface
ControlledWorkerBindJoinBase.TaskCreator
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Field Summary
Fields Modifier and Type Field Description protected Phaser
phaser
protected ControlledWorkerScheduler<BindingSet>
scheduler
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Fields inherited from class org.eclipse.rdf4j.federated.evaluation.join.JoinExecutorBase
bindings, joinVars, leftIter, rightArg
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Fields inherited from class org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelExecutorBase
evaluationThread, executorId, finished, NEXT_EXECUTOR_ID, queryInfo, rightIter, rightQueue, strategy
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Constructor Summary
Constructors Constructor Description ControlledWorkerBindJoinBase(ControlledWorkerScheduler<BindingSet> scheduler, FederationEvalStrategy strategy, CloseableIteration<BindingSet> leftIter, TupleExpr rightArg, BindingSet bindings, QueryInfo queryInfo)
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected abstract ControlledWorkerBindJoinBase.TaskCreator
determineTaskCreator(TupleExpr expr, BindingSet bs)
Return theControlledWorkerBindJoinBase.TaskCreator
for executing the bind joinprotected int
getNextBindJoinSize(int configuredBindJoinSize, int totalBindings)
Return the size of the next bind join block.protected void
handleBindings()
Implementations must implement this method to handle bindings.void
handleClose()
Called byAbstractCloseableIteration.close()
when it is called for the first time.-
Methods inherited from class org.eclipse.rdf4j.federated.evaluation.join.JoinExecutorBase
getExecutorType, getJoinVars, performExecution, setJoinVars
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Methods inherited from class org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelExecutorBase
addResult, checkTimeout, done, getDisplayId, getId, getNextElement, getQueryInfo, isFinished, run, toss, toString
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Methods inherited from class org.eclipse.rdf4j.common.iteration.LookAheadIteration
hasNext, next, remove
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Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration
close, isClosed
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.eclipse.rdf4j.common.iteration.CloseableIteration
stream
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Methods inherited from interface java.util.Iterator
forEachRemaining
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Field Detail
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scheduler
protected final ControlledWorkerScheduler<BindingSet> scheduler
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phaser
protected final Phaser phaser
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Constructor Detail
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ControlledWorkerBindJoinBase
public ControlledWorkerBindJoinBase(ControlledWorkerScheduler<BindingSet> scheduler, FederationEvalStrategy strategy, CloseableIteration<BindingSet> leftIter, TupleExpr rightArg, BindingSet bindings, QueryInfo queryInfo) throws QueryEvaluationException
- Throws:
QueryEvaluationException
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Method Detail
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handleBindings
protected void handleBindings() throws Exception
Description copied from class:JoinExecutorBase
Implementations must implement this method to handle bindings. Use the following as a templatewhile (!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 Note that the implementation must block until the entire join is executed.- Specified by:
handleBindings
in classJoinExecutorBase<BindingSet>
- Throws:
Exception
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handleClose
public void handleClose() throws QueryEvaluationException
Description copied from class:AbstractCloseableIteration
Called byAbstractCloseableIteration.close()
when it is called for the first time. This method is only called once on each iteration. By default, this method does nothing.- Overrides:
handleClose
in classJoinExecutorBase<BindingSet>
- Throws:
QueryEvaluationException
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determineTaskCreator
protected abstract ControlledWorkerBindJoinBase.TaskCreator determineTaskCreator(TupleExpr expr, BindingSet bs)
Return theControlledWorkerBindJoinBase.TaskCreator
for executing the bind join- Parameters:
expr
-bs
-- Returns:
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getNextBindJoinSize
protected int getNextBindJoinSize(int configuredBindJoinSize, int totalBindings)
Return the size of the next bind join block.- Parameters:
configuredBindJoinSize
- the configured bind join sizetotalBindings
- the current process bindings from the intermediate result set- Returns:
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