Class UnaryExecutableOpBaseWithoutBlocking

java.lang.Object

se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.BaseForExecOps

se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.UnaryExecutableOpBase

se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.UnaryExecutableOpBaseWithoutBlocking

All Implemented Interfaces:

StatsProvider, ExecutableOperator, UnaryExecutableOp

Direct Known Subclasses:

ExecOpBind, ExecOpFilter, ExecOpGlobalToLocal, ExecOpLocalToGlobal

public abstract class UnaryExecutableOpBaseWithoutBlocking
extends UnaryExecutableOpBase

Base class for all implementations of UnaryExecutableOp that do not need to process the input solution mappings in batches (the filter operator is a typical example). For such operators, this base class implements the _process(List, IntermediateResultElementSink, ExecutionContext) method in a way that the given list is still consumed in batches, where each batch is processed by the _process(Iterator, int, IntermediateResultElementSink, ExecutionContext) method. Classes that extend this base class should override this method. The purpose of consuming the input list of solution mappings in batches is to increase inter-operator parallelism in the executable plans, in particular in cases in which the input list is huge. If such a huge input list was first processed completely to collect all the output solution mappings for the parent operator in the plan, then the parent operator may idle. Of course, it is also possible to directly send all output solution mappings individually to the parent operator, but that should be avoided to reduce the communication between the threads that run these operators.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MAX_BATCH_SIZE

Fields inherited from class se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.BaseForExecOps

collectExceptions, qpInfo

Constructor Summary

Constructors

Constructor	Description
UnaryExecutableOpBaseWithoutBlocking(boolean collectExceptions, QueryPlanningInfo qpInfo)

Method Summary

Modifier and Type	Method	Description
protected void	_process(Iterator<SolutionMapping> inputSolMaps, int maxBatchSize, IntermediateResultElementSink sink, ExecutionContext execCxt)	Processes input solution mappings of the given iterator by calling UnaryExecutableOpBase._process(SolutionMapping, IntermediateResultElementSink, ExecutionContext) for each of them, but consumes only as many input solution mappings as specified by the maxBatchSize argument (or less if the given iterator is exhausted earlier).
protected final void	_process(List<SolutionMapping> inputSolMaps, IntermediateResultElementSink sink, ExecutionContext execCxt)	Processes the input solution mappings of the given list by calling UnaryExecutableOpBase._process(SolutionMapping, IntermediateResultElementSink, ExecutionContext) for each of them.

Methods inherited from class se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.UnaryExecutableOpBase

_concludeExecution, _process, concludeExecution, createStats, getStats, process, process, resetStats

Methods inherited from class se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.BaseForExecOps

getExceptionsCaughtDuringExecution, getQueryPlanningInfo, recordExceptionCaughtDuringExecution

Methods inherited from class java.lang.Object

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

Methods inherited from interface se.liu.ida.hefquin.engine.queryplan.executable.ExecutableOperator

getExceptionsCaughtDuringExecution, getQueryPlanningInfo

Field Details

MAX_BATCH_SIZE

public static final int MAX_BATCH_SIZE

See Also:

• Constant Field Values

Constructor Details

UnaryExecutableOpBaseWithoutBlocking

public UnaryExecutableOpBaseWithoutBlocking(boolean collectExceptions,
 QueryPlanningInfo qpInfo)

Method Details

_process

protected final void _process(List<SolutionMapping> inputSolMaps,
 IntermediateResultElementSink sink,
 ExecutionContext execCxt)
                       throws ExecOpExecutionException

Description copied from class: UnaryExecutableOpBase

Processes the input solution mappings of the given list by calling UnaryExecutableOpBase._process(SolutionMapping, IntermediateResultElementSink, ExecutionContext) for each of them. Subclasses may override this behavior to send a greater number of output solution mappings to the given sink at a time (which is useful to reduce the communication between threads in the push-based execution model). If an exception occurs within the overriding implementation, then this exception needs to be thrown.

Overrides:

_process in class UnaryExecutableOpBase

Throws:

ExecOpExecutionException

_process

protected void _process(Iterator<SolutionMapping> inputSolMaps,
 int maxBatchSize,
 IntermediateResultElementSink sink,
 ExecutionContext execCxt)
                 throws ExecOpExecutionException

Processes input solution mappings of the given iterator by calling UnaryExecutableOpBase._process(SolutionMapping, IntermediateResultElementSink, ExecutionContext) for each of them, but consumes only as many input solution mappings as specified by the maxBatchSize argument (or less if the given iterator is exhausted earlier). Subclasses may override this behavior to send a greater number of output solution mappings to the given sink at a time (which is useful to reduce the communication between threads in the push-based execution model). Yet, overriding implementations should not call the given iterator more often as specified by the maxBatchSize argument. If an exception occurs within the overriding implementation, then this exception needs to be thrown.

Throws:

ExecOpExecutionException