org.apache.beam.sdk.transforms

Class Min.MinFn<T>

java.lang.Object

org.apache.beam.sdk.transforms.Combine.CombineFn<V,Combine.Holder<V>,V>

org.apache.beam.sdk.transforms.Combine.BinaryCombineFn<T>

org.apache.beam.sdk.transforms.Min.MinFn<T>

Type Parameters:

T - the type of the values being compared

All Implemented Interfaces:

Serializable, CombineFnBase.GlobalCombineFn<T,Combine.Holder<T>,T>, HasDisplayData

Enclosing class:

Min

public static class Min.MinFn<T>
extends Combine.BinaryCombineFn<T>

A CombineFn that computes the maximum of a collection of elements of type T using an arbitrary Comparator, 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

Method Summary

Modifier and Type	Method and Description
T	apply(T left, T right) Applies the binary operation to the two operands, returning the result.
TypeVariable<?>	getAccumTVariable() Returns the TypeVariable of AccumT.
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.
T	identity() Returns the value that should be used for the combine of the empty set.
static <T extends Comparable<? super T>> Min.MinFn<T>	naturalOrder()
static <T extends Comparable<? super T>> Min.MinFn<T>	naturalOrder(T identity)
static <T,ComparatorT extends Comparator<? super T> & Serializable> Min.MinFn<T>	of(ComparatorT comparator)
static <T,ComparatorT extends Comparator<? super T> & Serializable> Min.MinFn<T>	of(T identity, ComparatorT comparator)
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.

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

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

Method Detail

of

public static <T,ComparatorT extends Comparator<? super T> & Serializable> Min.MinFn<T> of(T identity,
                                                                                           ComparatorT comparator)

of

public static <T,ComparatorT extends Comparator<? super T> & Serializable> Min.MinFn<T> of(ComparatorT comparator)

naturalOrder

public static <T extends Comparable<? super T>> Min.MinFn<T> naturalOrder(T identity)

naturalOrder

public static <T extends Comparable<? super T>> Min.MinFn<T> naturalOrder()

identity

public T identity()

Description copied from class: Combine.BinaryCombineFn

Returns the value that should be used for the combine of the empty set.

Overrides:

identity in class Combine.BinaryCombineFn<T>

apply

public T apply(T left,
               T right)

Description copied from class: Combine.BinaryCombineFn

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

Specified by:

apply in class Combine.BinaryCombineFn<T>

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

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.