org.apache.beam.sdk.transforms

Class Sum.SumDoubleFn

java.lang.Object

org.apache.beam.sdk.transforms.Combine.CombineFn<Double,double[],Double>

org.apache.beam.sdk.transforms.Combine.BinaryCombineDoubleFn

org.apache.beam.sdk.transforms.Sum.SumDoubleFn

All Implemented Interfaces:

Serializable, CombineFnBase.GlobalCombineFn<Double,double[],Double>, HasDisplayData, org.apache.beam.sdk.util.common.CounterProvider<Double>

Enclosing class:

Sum

public static class Sum.SumDoubleFn
extends Combine.BinaryCombineDoubleFn
implements org.apache.beam.sdk.util.common.CounterProvider<Double>

A SerializableFunction that computes the sum of an Iterable of Doubles, useful as an argument to Combine.globally(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>) or Combine.perKey(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>).

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SumDoubleFn()

Method Summary

Modifier and Type	Method and Description
double	apply(double a, double b) Applies the binary operation to the two operands, returning the result.
TypeVariable<?>	getAccumTVariable() Returns the TypeVariable of AccumT.
org.apache.beam.sdk.util.common.Counter<Double>	getCounter(String name)
String	getIncompatibleGlobalWindowErrorMessage() Returns the error message for not supported default values in Combine.globally().
TypeVariable<?>	getInputTVariable() Returns the TypeVariable of InputT.
TypeVariable<?>	getOutputTVariable() Returns the TypeVariable of OutputT.
double	identity() Returns the identity element of this operation, i.e.
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.

Methods inherited from class org.apache.beam.sdk.transforms.Combine.BinaryCombineDoubleFn

addInput, createAccumulator, extractOutput, getAccumulatorCoder, getDefaultOutputCoder, mergeAccumulators

Methods inherited from class org.apache.beam.sdk.transforms.Combine.CombineFn

apply, asKeyedFn, compact, defaultValue, getOutputType

Methods inherited from class java.lang.Object

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

Constructor Detail

SumDoubleFn

public SumDoubleFn()

Method Detail

apply

public double apply(double a,
                    double b)

Description copied from class: Combine.BinaryCombineDoubleFn

Applies the binary operation to the two operands, returning the result.

Specified by:

apply in class Combine.BinaryCombineDoubleFn

identity

public double identity()

Description copied from class: Combine.BinaryCombineDoubleFn

Returns the identity element of this operation, i.e. an element e such that apply(e, x) == apply(x, e) == x for all values of x.

Specified by:

identity in class Combine.BinaryCombineDoubleFn

getCounter

public org.apache.beam.sdk.util.common.Counter<Double> getCounter(String name)

Specified by:

getCounter in interface org.apache.beam.sdk.util.common.CounterProvider<Double>

Overrides:

getCounter in class Combine.BinaryCombineDoubleFn

getIncompatibleGlobalWindowErrorMessage

public String getIncompatibleGlobalWindowErrorMessage()

Description copied from interface: CombineFnBase.GlobalCombineFn

Returns the error message for not supported default values in Combine.globally().

Specified by:

getIncompatibleGlobalWindowErrorMessage in interface CombineFnBase.GlobalCombineFn<InputT,AccumT,OutputT>

getInputTVariable

public TypeVariable<?> getInputTVariable()

Returns the TypeVariable of InputT.

getAccumTVariable

public TypeVariable<?> getAccumTVariable()

Returns the TypeVariable of AccumT.

getOutputTVariable

public TypeVariable<?> getOutputTVariable()

Returns the TypeVariable of OutputT.

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Register display data for the given transform or component.

populateDisplayData(DisplayData.Builder) is invoked by Pipeline runners to collect display data via DisplayData.from(HasDisplayData). Implementations may call super.populateDisplayData(builder) in order to register display data in the current namespace, but should otherwise use subcomponent.populateDisplayData(builder) to use the namespace of the subcomponent.

By default, does not register any display data. Implementors may override this method to provide their own display data.

Specified by:

populateDisplayData in interface HasDisplayData

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData