TypedCombineFnDelegate (Apache Beam 2.58.0)

java.lang.Object
- org.apache.beam.sdk.transforms.Combine.CombineFn<InputT,AccumT,OutputT>
- - org.apache.beam.sdk.extensions.sql.TypedCombineFnDelegate<InputT,AccumT,OutputT>

Type Parameters:

InputT - the type of input

AccumT - the type of accumulator

OutputT - the type of output

All Implemented Interfaces:

java.io.Serializable, CombineFnBase.GlobalCombineFn<InputT,AccumT,OutputT>, HasDisplayData
```
public class TypedCombineFnDelegate<InputT,AccumT,OutputT>
extends Combine.CombineFn<InputT,AccumT,OutputT>
```
A Combine.CombineFn delegating all relevant calls to given delegate. This is used to create a type anonymous class for cases where the CombineFn is a generic class. The anonymous class can then be used in a UDAF as
```
   .registerUdaf("UDAF", new TypedCombineFnDelegate<>(genericCombineFn) {})
 
```
See Also:

Serialized Form

Constructor Summary

Constructors
Modifier Constructor and Description

protected TypedCombineFnDelegate(Combine.CombineFn<InputT,AccumT,OutputT> delegate)

Constructors
Modifier	Constructor and Description
`protected`	`TypedCombineFnDelegate(Combine.CombineFn<InputT,AccumT,OutputT> delegate)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`AccumT`	`addInput(AccumT mutableAccumulator, InputT input)` Adds the given input value to the given accumulator, returning the new accumulator value.
`OutputT`	`apply(java.lang.Iterable<? extends InputT> inputs)` Applies this `CombineFn` to a collection of input values to produce a combined output value.
`AccumT`	`compact(AccumT accumulator)` Returns an accumulator that represents the same logical value as the input accumulator, but may have a more compact representation.
`AccumT`	`createAccumulator()` Returns a new, mutable accumulator value, representing the accumulation of zero input values.
`OutputT`	`defaultValue()` Returns the default value when there are no values added to the accumulator.
`OutputT`	`extractOutput(AccumT accumulator)` Returns the output value that is the result of combining all the input values represented by the given accumulator.
`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`.
`TypeDescriptor<InputT>`	`getInputType()` Returns a `TypeDescriptor` capturing what is known statically about the input type of this `CombineFn` instance's most-derived class.
`java.lang.reflect.TypeVariable<?>`	`getOutputTVariable()` Returns the `TypeVariable` of `OutputT`.
`TypeDescriptor<OutputT>`	`getOutputType()` Returns a `TypeDescriptor` capturing what is known statically about the output type of this `CombineFn` instance's most-derived class.
`AccumT`	`mergeAccumulators(java.lang.Iterable<AccumT> accumulators)` 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.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - TypedCombineFnDelegate
```
protected TypedCombineFnDelegate(Combine.CombineFn<InputT,AccumT,OutputT> delegate)
```
- Method Detail
  - getOutputType
```
public TypeDescriptor<OutputT> getOutputType()
```
    Description copied from class: Combine.CombineFn
    
    Returns a TypeDescriptor capturing what is known statically about the output type of this CombineFn instance's most-derived class.
    In the normal case of a concrete CombineFn subclass with no generic type parameters of its own, this will be a complete non-generic type.
    
    Overrides:
    
    getOutputType in class Combine.CombineFn<InputT,AccumT,OutputT>
  - getInputType
```
public TypeDescriptor<InputT> getInputType()
```
    Description copied from class: Combine.CombineFn
    
    Returns a TypeDescriptor capturing what is known statically about the input type of this CombineFn instance's most-derived class.
    In the normal case of a concrete CombineFn subclass with no generic type parameters of its own, this will be a complete non-generic type.
    
    Overrides:
    
    getInputType in class Combine.CombineFn<InputT,AccumT,OutputT>
  - createAccumulator
```
public AccumT createAccumulator()
```
    Description copied from class: Combine.CombineFn
    
    Returns a new, mutable accumulator value, representing the accumulation of zero input values.
    
    Specified by:
    
    createAccumulator in class Combine.CombineFn<InputT,AccumT,OutputT>
  - addInput
```
public AccumT addInput(AccumT mutableAccumulator,
                       InputT input)
```
    Description copied from class: Combine.CombineFn
    
    Adds the given input value to the given accumulator, returning the new accumulator value.
    
    Specified by:
    
    addInput in class Combine.CombineFn<InputT,AccumT,OutputT>
    
    Parameters:
    
    mutableAccumulator - may be modified and returned for efficiency
    
    input - should not be mutated
  - mergeAccumulators
```
public AccumT mergeAccumulators(java.lang.Iterable<AccumT> accumulators)
```
    Description copied from class: Combine.CombineFn
    
    Returns an accumulator representing the accumulation of all the input values accumulated in the merging accumulators.
    
    Specified by:
    
    mergeAccumulators in class Combine.CombineFn<InputT,AccumT,OutputT>
    
    Parameters:
    
    accumulators - only the first accumulator may be modified and returned for efficiency; the other accumulators should not be mutated, because they may be shared with other code and mutating them could lead to incorrect results or data corruption.
  - extractOutput
```
public OutputT extractOutput(AccumT accumulator)
```
    Description copied from class: Combine.CombineFn
    
    Returns the output value that is the result of combining all the input values represented by the given accumulator.
    
    Specified by:
    
    extractOutput in class Combine.CombineFn<InputT,AccumT,OutputT>
    
    Parameters:
    
    accumulator - can be modified for efficiency
  - compact
```
public AccumT compact(AccumT accumulator)
```
    Description copied from class: Combine.CombineFn
    
    Returns an accumulator that represents the same logical value as the input accumulator, but may have a more compact representation.
    For most CombineFns this would be a no-op, but should be overridden by CombineFns that (for example) buffer up elements and combine them in batches.
    For efficiency, the input accumulator may be modified and returned.
    By default returns the original accumulator.
    
    Overrides:
    
    compact in class Combine.CombineFn<InputT,AccumT,OutputT>
  - apply
```
public OutputT apply(java.lang.Iterable<? extends InputT> inputs)
```
    Description copied from class: Combine.CombineFn
    
    Applies this CombineFn to a collection of input values to produce a combined output value.
    Useful when using a CombineFn separately from a Combine transform. Does not invoke the Combine.CombineFn.mergeAccumulators(java.lang.Iterable<AccumT>) operation.
    
    Overrides:
    
    apply in class Combine.CombineFn<InputT,AccumT,OutputT>
  - defaultValue
```
public OutputT defaultValue()
```
    Description copied from class: Combine.CombineFn
    
    Returns the default value when there are no values added to the accumulator.
    By default returns the extract output of an empty accumulator.
    
    Specified by:
    
    defaultValue in interface CombineFnBase.GlobalCombineFn<InputT,AccumT,OutputT>
    
    Overrides:
    
    defaultValue in class Combine.CombineFn<InputT,AccumT,OutputT>
  - 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.
  - 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

Class TypedCombineFnDelegate<InputT,AccumT,OutputT>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

TypedCombineFnDelegate

Method Detail

getOutputType

getInputType

createAccumulator

addInput

mergeAccumulators

extractOutput

compact

apply

defaultValue

getAccumulatorCoder

getDefaultOutputCoder

getIncompatibleGlobalWindowErrorMessage

getInputTVariable

getAccumTVariable

getOutputTVariable

populateDisplayData