Class BaseForUnaryExecOpWithCollectedInput

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.BaseForUnaryExecOpWithCollectedInput

All Implemented Interfaces:

StatsProvider, ExecutableOperator, UnaryExecutableOp

Direct Known Subclasses:

BaseForExecOpIndexNestedLoopsJoinWithRequestOps, BaseForExecOpIndexNestedLoopsJoinWithRequests, BaseForExecOpParallelBindJoin, ExecOpLookupJoinViaWrapperWithParamVars, ExecOpParallelMultiwayLeftJoin

public abstract class BaseForUnaryExecOpWithCollectedInput
extends UnaryExecutableOpBase

Base class for all implementations of UnaryExecutableOp that work more effectively if at least a minimum number of input solution mappings are available to process. To this end, the functionality of this base class is to collect the input solution mappings until there are at least as many as specified by the minimumCollectionSize argument of the constructor and, then, pass the resulting batch of collected input solution mappings to the _processCollectedInput function implemented by the operator that is implemented as an extension of this base class. If further input solution mappings arrive after that, then these are collected again, and so on.

Notice that the specified minimumCollectionSize is only a lower bound; if multiple input solution mapping arrive at the same time, they are all added into the current collection, which may result in collections that contain (many) more than the minimum number of solution mappings.

Classes that extend this base class need to implement two functions:

• _processCollectedInput(List, IntermediateResultElementSink, ExecutionContext) and
• _concludeExecution(List, IntermediateResultElementSink, ExecutionContext).

Field Summary

Fields

Modifier and Type	Field	Description
protected final List<SolutionMapping>	collectedInputSolMaps
protected final int	minimumCollectionSize

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

collectExceptions, qpInfo

Constructor Summary

Constructors

Constructor	Description
BaseForUnaryExecOpWithCollectedInput(int minimumCollectionSize, boolean collectExceptions, QueryPlanningInfo qpInfo)

Method Summary

Modifier and Type	Method	Description
protected abstract void	_concludeExecution(List<SolutionMapping> currentBatch, IntermediateResultElementSink sink, ExecutionContext execCxt)	Implementations of this function need to process the given solution mappings as last input, conclude the execution of this operator, and send the remaining result elements (if any) to the given sink.
protected final void	_concludeExecution(IntermediateResultElementSink sink, ExecutionContext execCxt)	Implementations of this function need to conclude the execution of this operator and send the remaining result elements (if any) to the given sink.
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.
protected final void	_process(SolutionMapping inputSolMap, IntermediateResultElementSink sink, ExecutionContext execCxt)	Implementations of this function need to process the given solution mapping as input and send the produced result elements (if any) to the given sink.
protected abstract void	_processCollectedInput(List<SolutionMapping> currentBatch, IntermediateResultElementSink sink, ExecutionContext execCxt)	Implementations of this function need to process the given solution mappings as input and send the produced result elements (if any) to the given sink.
protected ExecutableOperatorStatsImpl	createStats()
void	resetStats()

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

concludeExecution, getStats, process, process

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

minimumCollectionSize

protected final int minimumCollectionSize

collectedInputSolMaps

protected final List<SolutionMapping> collectedInputSolMaps

Constructor Details

BaseForUnaryExecOpWithCollectedInput

public BaseForUnaryExecOpWithCollectedInput(int minimumCollectionSize,
 boolean collectExceptions,
 QueryPlanningInfo qpInfo)

Method Details

_process

protected final void _process(SolutionMapping inputSolMap,
 IntermediateResultElementSink sink,
 ExecutionContext execCxt)
                       throws ExecOpExecutionException

Description copied from class: UnaryExecutableOpBase

Implementations of this function need to process the given solution mapping as input and send the produced result elements (if any) to the given sink. If an exception occurs while processing the solution mapping, then this exception needs to be thrown.

Specified by:

_process in class UnaryExecutableOpBase

Throws:

ExecOpExecutionException

_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

_concludeExecution

protected final void _concludeExecution(IntermediateResultElementSink sink,
 ExecutionContext execCxt)
                                 throws ExecOpExecutionException

Description copied from class: UnaryExecutableOpBase

Implementations of this function need to conclude the execution of this operator and send the remaining result elements (if any) to the given sink. If an exception occurs during this process, then this exception needs to be thrown.

Specified by:

_concludeExecution in class UnaryExecutableOpBase

Throws:

ExecOpExecutionException

_processCollectedInput

protected abstract void _processCollectedInput(List<SolutionMapping> currentBatch,
 IntermediateResultElementSink sink,
 ExecutionContext execCxt)
                                        throws ExecOpExecutionException

Implementations of this function need to process the given solution mappings as input and send the produced result elements (if any) to the given sink. If an exception occurs while processing the solution mappings, then this exception needs to be thrown.

Throws:

ExecOpExecutionException

_concludeExecution

protected abstract void _concludeExecution(List<SolutionMapping> currentBatch,
 IntermediateResultElementSink sink,
 ExecutionContext execCxt)
                                    throws ExecOpExecutionException

Implementations of this function need to process the given solution mappings as last input, conclude the execution of this operator, and send the remaining result elements (if any) to the given sink. Notice that the list of solution mappings given here may contain fewer solution mappings than the minimum collection size, and it may even be empty! If an exception occurs during this process, then this exception needs to be thrown.

Throws:

ExecOpExecutionException

resetStats

public void resetStats()

Specified by:

resetStats in interface StatsProvider

Overrides:

resetStats in class UnaryExecutableOpBase

createStats

protected ExecutableOperatorStatsImpl createStats()

Overrides:

createStats in class UnaryExecutableOpBase