Package org.apache.wayang.basic.operators

Class CountOperator<Type>

java.lang.Object

org.apache.wayang.core.plan.wayangplan.OperatorBase

org.apache.wayang.core.plan.wayangplan.UnaryToUnaryOperator<Type,java.lang.Long>

org.apache.wayang.basic.operators.CountOperator<Type>

All Implemented Interfaces:

java.io.Serializable, ActualOperator, ElementaryOperator, Operator

Direct Known Subclasses:

FlinkCountOperator, JavaCountOperator, SparkCountOperator

public class CountOperator<Type>
extends UnaryToUnaryOperator<Type,java.lang.Long>

This operator returns the count of elements in this stream.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.wayang.core.plan.wayangplan.OperatorBase

OperatorBase.GsonSerializer

Field Summary

Fields inherited from class org.apache.wayang.core.plan.wayangplan.OperatorBase

inputSlots, outputSlots, STANDARD_OPERATOR_ARGS

Fields inherited from interface org.apache.wayang.core.plan.wayangplan.Operator

FIRST_EPOCH

Constructor Summary

Constructors

Constructor	Description
CountOperator(java.lang.Class<Type> typeClass)	Creates a new instance.
CountOperator(CountOperator<Type> that)	Copies an instance (exclusive of broadcasts).
CountOperator(DataSetType<Type> type)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
java.util.Optional<CardinalityEstimator>	createCardinalityEstimator(int outputIndex, Configuration configuration)	Provide a CardinalityEstimator for the OutputSlot at outputIndex.

Methods inherited from class org.apache.wayang.core.plan.wayangplan.UnaryToUnaryOperator

getInput, getInputType, getOutput, getOutputType

Methods inherited from class org.apache.wayang.core.plan.wayangplan.OperatorBase

accept, addBroadcastInput, addTargetPlatform, at, collectMappedInputSlots, collectMappedOutputSlots, copy, createCopy, getAllInputs, getAllOutputs, getCardinalityEstimator, getContainer, getEpoch, getName, getOriginal, getSimpleClassName, getTargetPlatforms, isAuxiliary, isSupportingBroadcastInputs, propagateInputCardinality, propagateOutputCardinality, setAuxiliary, setCardinalityEstimator, setContainer, setEpoch, setName, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.wayang.core.plan.wayangplan.ActualOperator

accept

Methods inherited from interface org.apache.wayang.core.plan.wayangplan.ElementaryOperator

getCardinalityEstimator, isAuxiliary, setAuxiliary, setCardinalityEstimator

Methods inherited from interface org.apache.wayang.core.plan.wayangplan.Operator

addBroadcastInput, addTargetPlatform, broadcastTo, broadcastTo, collectMappedInputSlots, collectMappedOutputSlots, connectTo, connectTo, getAllInputs, getAllOutputs, getCardinalityPusher, getContainer, getEffectiveOccupant, getEffectiveOccupant, getEpoch, getEstimationContextProperties, getForwards, getInnermostLoop, getInput, getInput, getLoopStack, getName, getNumBroadcastInputs, getNumInputs, getNumOutputs, getNumRegularInputs, getOuterInputSlot, getOutermostInputSlot, getOutermostOutputSlots, getOutput, getOutput, getParent, getTargetPlatforms, isAlternative, isElementary, isExecutionOperator, isFeedbackInput, isFeedforwardOutput, isLoopHead, isLoopSubplan, isOwnerOf, isReading, isSink, isSource, isSubplan, isSupportingBroadcastInputs, isUnconnected, propagateInputCardinality, propagateOutputCardinality, propagateOutputCardinality, setContainer, setEpoch, setInput, setName, setOutput

Constructor Detail

CountOperator

public CountOperator(DataSetType<Type> type)

Creates a new instance.

Parameters:

type - type of the stream elements

CountOperator

public CountOperator(java.lang.Class<Type> typeClass)

Creates a new instance.

Parameters:

typeClass - type of the stream elements

CountOperator

public CountOperator(CountOperator<Type> that)

Copies an instance (exclusive of broadcasts).

Parameters:

that - that should be copied

Method Detail

createCardinalityEstimator

public java.util.Optional<CardinalityEstimator> createCardinalityEstimator(int outputIndex,
                                                                           Configuration configuration)

Description copied from interface: ElementaryOperator

Provide a CardinalityEstimator for the OutputSlot at outputIndex.

Parameters:

outputIndex - index of the OutputSlot for that the CardinalityEstimator is requested

configuration - if the CardinalityEstimator depends on further ones, use this to obtain the latter

Returns:

an Optional that might provide the requested instance