org.apache.beam.sdk.transforms

Class Combine.SimpleCombineFn<V>

java.lang.Object

org.apache.beam.sdk.transforms.Combine.CombineFn<V,java.util.List<V>,V>

org.apache.beam.sdk.transforms.Combine.IterableCombineFn<V>

org.apache.beam.sdk.transforms.Combine.SimpleCombineFn<V>

All Implemented Interfaces:

java.io.Serializable, CombineFnBase.GlobalCombineFn<V,java.util.List<V>,V>, HasDisplayData, org.apache.beam.sdk.util.NameUtils.NameOverride

Enclosing class:

Combine

Deprecated.

@Deprecated
public static class Combine.SimpleCombineFn<V>
extends Combine.IterableCombineFn<V>

Converts a SerializableFunction from Iterable<V>s to Vs into a simple Combine.CombineFn over Vs.

@deprecated Use Combine.IterableCombineFn or the more space efficient Combine.BinaryCombineFn instead (which avoids buffering values).

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimpleCombineFn(SerializableFunction<java.lang.Iterable<V>,V> combiner) Deprecated.

Method Summary

Modifier and Type	Method and Description
java.lang.reflect.TypeVariable<?>	getAccumTVariable() Returns the TypeVariable of AccumT.
Coder<AccumT>	getAccumulatorCoder(CoderRegistry registry, Coder<InputT> inputCoder) Returns the Coder to use for accumulator AccumT values, or null if it is not able to be inferred.
Coder<OutputT>	getDefaultOutputCoder(CoderRegistry registry, Coder<InputT> inputCoder) Returns the Coder to use by default for output OutputT values, or null if it is not able to be inferred.
java.lang.String	getIncompatibleGlobalWindowErrorMessage() Returns the error message for not supported default values in Combine.globally().
java.lang.reflect.TypeVariable<?>	getInputTVariable() Returns the TypeVariable of InputT.
java.lang.reflect.TypeVariable<?>	getOutputTVariable() Returns the TypeVariable of OutputT.
static <V> Combine.SimpleCombineFn<V>	of(SerializableFunction<java.lang.Iterable<V>,V> combiner) Deprecated.

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

addInput, compact, createAccumulator, extractOutput, getNameOverride, mergeAccumulators, of, populateDisplayData

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

apply, defaultValue, getOutputType

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleCombineFn

protected SimpleCombineFn(SerializableFunction<java.lang.Iterable<V>,V> combiner)

Deprecated.

Method Detail

of

@Deprecated
public static <V> Combine.SimpleCombineFn<V> of(SerializableFunction<java.lang.Iterable<V>,V> combiner)

Deprecated.

Returns a CombineFn that uses the given SerializableFunction to combine values.

getAccumulatorCoder

public Coder<AccumT> getAccumulatorCoder(CoderRegistry registry,
                                         Coder<InputT> inputCoder)
                                  throws CannotProvideCoderException

Description copied from interface: CombineFnBase.GlobalCombineFn

Returns the Coder to use for accumulator AccumT values, or null if it is not able to be inferred.

By default, uses the knowledge of the Coder being used for InputT values and the enclosing Pipeline's CoderRegistry to try to infer the Coder for AccumT values.

This is the Coder used to send data through a communication-intensive shuffle step, so a compact and efficient representation may have significant performance benefits.

Specified by:

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

Throws:

CannotProvideCoderException

getDefaultOutputCoder

public Coder<OutputT> getDefaultOutputCoder(CoderRegistry registry,
                                            Coder<InputT> inputCoder)
                                     throws CannotProvideCoderException

Description copied from interface: CombineFnBase.GlobalCombineFn

Returns the Coder to use by default for output OutputT values, or null if it is not able to be inferred.

By default, uses the knowledge of the Coder being used for input InputT values and the enclosing Pipeline's CoderRegistry to try to infer the Coder for OutputT values.

Specified by:

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

Throws:

CannotProvideCoderException

getIncompatibleGlobalWindowErrorMessage

public java.lang.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 java.lang.reflect.TypeVariable<?> getInputTVariable()

Returns the TypeVariable of InputT.

getAccumTVariable

public java.lang.reflect.TypeVariable<?> getAccumTVariable()

Returns the TypeVariable of AccumT.

getOutputTVariable

public java.lang.reflect.TypeVariable<?> getOutputTVariable()

Returns the TypeVariable of OutputT.