org.apache.beam.sdk.transforms

Class CombineFns.ComposedKeyedCombineFnWithContext<DataT,K>

java.lang.Object

org.apache.beam.sdk.transforms.CombineWithContext.KeyedCombineFnWithContext<K,DataT,Object[],CombineFns.CoCombineResult>

org.apache.beam.sdk.transforms.CombineFns.ComposedKeyedCombineFnWithContext<DataT,K>

All Implemented Interfaces:

Serializable, CombineFnBase.PerKeyCombineFn<K,DataT,Object[],CombineFns.CoCombineResult>, CombineWithContext.RequiresContextInternal, HasDisplayData

Enclosing class:

CombineFns

public static class CombineFns.ComposedKeyedCombineFnWithContext<DataT,K>
extends CombineWithContext.KeyedCombineFnWithContext<K,DataT,Object[],CombineFns.CoCombineResult>

A composed CombineWithContext.KeyedCombineFnWithContext that applies multiple KeyedCombineFnWithContexts.

For each CombineWithContext.KeyedCombineFnWithContext it extracts inputs from DataT with the extractInputFn and combines them, and then it outputs each combined value with a TupleTag to a CombineFns.CoCombineResult.

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
Object[]	addInput(K key, Object[] accumulator, DataT value, CombineWithContext.Context c) Adds the given input value to the given accumulator, returning the new accumulator value.
Object[]	compact(K key, Object[] accumulator, CombineWithContext.Context c) Returns an accumulator that represents the same logical value as the input accumulator, but may have a more compact representation.
Object[]	createAccumulator(K key, CombineWithContext.Context c) Returns a new, mutable accumulator value representing the accumulation of zero input values.
CombineFns.CoCombineResult	extractOutput(K key, Object[] accumulator, CombineWithContext.Context c) Returns the output value that is the result of combining all the input values represented by the given accumulator.
TypeVariable<?>	getAccumTVariable() Returns the TypeVariable of AccumT.
Coder<Object[]>	getAccumulatorCoder(CoderRegistry registry, Coder<K> keyCoder, Coder<DataT> dataCoder) 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<K> keyCoder, Coder<InputT> inputCoder) Returns the Coder to use by default for output OutputT values, or null if it is not able to be inferred.
TypeVariable<?>	getInputTVariable() Returns the TypeVariable of InputT.
TypeVariable<?>	getKTypeVariable() Returns the TypeVariable of K.
TypeVariable<?>	getOutputTVariable() Returns the TypeVariable of OutputT.
Object[]	mergeAccumulators(K key, Iterable<Object[]> accumulators, CombineWithContext.Context c) Returns an accumulator representing the accumulation of all the input values accumulated in the merging accumulators.
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.
<InputT,OutputT> CombineFns.ComposedKeyedCombineFnWithContext<DataT,K>	with(SimpleFunction<DataT,InputT> extractInputFn, CombineFnBase.GlobalCombineFn<InputT,?,OutputT> perKeyCombineFn, TupleTag<OutputT> outputTag) Returns a CombineFns.ComposedKeyedCombineFnWithContext with an additional CombineFnBase.GlobalCombineFn.
<InputT,OutputT> CombineFns.ComposedKeyedCombineFnWithContext<DataT,K>	with(SimpleFunction<DataT,InputT> extractInputFn, CombineFnBase.PerKeyCombineFn<K,InputT,?,OutputT> perKeyCombineFn, TupleTag<OutputT> outputTag) Returns a CombineFns.ComposedKeyedCombineFnWithContext with an additional CombineFnBase.PerKeyCombineFn.

Methods inherited from class org.apache.beam.sdk.transforms.CombineWithContext.KeyedCombineFnWithContext

apply, forKey

Methods inherited from class java.lang.Object

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

Method Detail

with

public <InputT,OutputT> CombineFns.ComposedKeyedCombineFnWithContext<DataT,K> with(SimpleFunction<DataT,InputT> extractInputFn,
                                                                                   CombineFnBase.PerKeyCombineFn<K,InputT,?,OutputT> perKeyCombineFn,
                                                                                   TupleTag<OutputT> outputTag)

Returns a CombineFns.ComposedKeyedCombineFnWithContext with an additional CombineFnBase.PerKeyCombineFn.

with

public <InputT,OutputT> CombineFns.ComposedKeyedCombineFnWithContext<DataT,K> with(SimpleFunction<DataT,InputT> extractInputFn,
                                                                                   CombineFnBase.GlobalCombineFn<InputT,?,OutputT> perKeyCombineFn,
                                                                                   TupleTag<OutputT> outputTag)

Returns a CombineFns.ComposedKeyedCombineFnWithContext with an additional CombineFnBase.GlobalCombineFn.

createAccumulator

public Object[] createAccumulator(K key,
                                  CombineWithContext.Context c)

Description copied from class: CombineWithContext.KeyedCombineFnWithContext

Returns a new, mutable accumulator value representing the accumulation of zero input values.

It is equivalent to Combine.KeyedCombineFn.createAccumulator(K), but it has additional access to CombineWithContext.Context.

Specified by:

createAccumulator in class CombineWithContext.KeyedCombineFnWithContext<K,DataT,Object[],CombineFns.CoCombineResult>

addInput

public Object[] addInput(K key,
                         Object[] accumulator,
                         DataT value,
                         CombineWithContext.Context c)

Description copied from class: CombineWithContext.KeyedCombineFnWithContext

Adds the given input value to the given accumulator, returning the new accumulator value.

It is equivalent to Combine.KeyedCombineFn.addInput(K, AccumT, InputT), but it has additional access to CombineWithContext.Context.

Specified by:

addInput in class CombineWithContext.KeyedCombineFnWithContext<K,DataT,Object[],CombineFns.CoCombineResult>

mergeAccumulators

public Object[] mergeAccumulators(K key,
                                  Iterable<Object[]> accumulators,
                                  CombineWithContext.Context c)

Description copied from class: CombineWithContext.KeyedCombineFnWithContext

Returns an accumulator representing the accumulation of all the input values accumulated in the merging accumulators.

It is equivalent to Combine.KeyedCombineFn.mergeAccumulators(K, java.lang.Iterable<AccumT>), but it has additional access to CombineWithContext.Context..

Specified by:

mergeAccumulators in class CombineWithContext.KeyedCombineFnWithContext<K,DataT,Object[],CombineFns.CoCombineResult>

extractOutput

public CombineFns.CoCombineResult extractOutput(K key,
                                                Object[] accumulator,
                                                CombineWithContext.Context c)

Description copied from class: CombineWithContext.KeyedCombineFnWithContext

Returns the output value that is the result of combining all the input values represented by the given accumulator.

It is equivalent to Combine.KeyedCombineFn.extractOutput(K, AccumT), but it has additional access to CombineWithContext.Context.

Specified by:

extractOutput in class CombineWithContext.KeyedCombineFnWithContext<K,DataT,Object[],CombineFns.CoCombineResult>

compact

public Object[] compact(K key,
                        Object[] accumulator,
                        CombineWithContext.Context c)

Description copied from class: CombineWithContext.KeyedCombineFnWithContext

Returns an accumulator that represents the same logical value as the input accumulator, but may have a more compact representation.

It is equivalent to Combine.KeyedCombineFn.compact(K, AccumT), but it has additional access to CombineWithContext.Context.

Overrides:

compact in class CombineWithContext.KeyedCombineFnWithContext<K,DataT,Object[],CombineFns.CoCombineResult>

getAccumulatorCoder

public Coder<Object[]> getAccumulatorCoder(CoderRegistry registry,
                                           Coder<K> keyCoder,
                                           Coder<DataT> dataCoder)
                                    throws CannotProvideCoderException

Description copied from interface: CombineFnBase.PerKeyCombineFn

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 K keys and input 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.PerKeyCombineFn<K,DataT,Object[],CombineFns.CoCombineResult>

Throws:

CannotProvideCoderException

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

getDefaultOutputCoder

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

Description copied from interface: CombineFnBase.PerKeyCombineFn

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 K keys and input InputT values and the enclosing Pipeline's CoderRegistry to try to infer the Coder for OutputT values.

Specified by:

getDefaultOutputCoder in interface CombineFnBase.PerKeyCombineFn<K,InputT,AccumT,OutputT>

Throws:

CannotProvideCoderException

getKTypeVariable

public TypeVariable<?> getKTypeVariable()

Returns the TypeVariable of K.

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.