Google Cloud Dataflow SDK for Java, version 1.9.1
Class CombineWithContext.KeyedCombineFnWithContext<K,InputT,AccumT,OutputT>
- java.lang.Object
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- com.google.cloud.dataflow.sdk.transforms.CombineWithContext.KeyedCombineFnWithContext<K,InputT,AccumT,OutputT>
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- All Implemented Interfaces:
- CombineFnBase.PerKeyCombineFn<K,InputT,AccumT,OutputT>, CombineWithContext.RequiresContextInternal, HasDisplayData, Serializable
- Direct Known Subclasses:
- CombineFns.ComposedKeyedCombineFnWithContext
- Enclosing class:
- CombineWithContext
public abstract static class CombineWithContext.KeyedCombineFnWithContext<K,InputT,AccumT,OutputT> extends Object implements CombineWithContext.RequiresContextInternal
A keyed combine function that has access toPipelineOptions
and side inputs throughCombineWithContext.Context
.See the equivalent
Combine.KeyedCombineFn
for details about keyed combine functions.- See Also:
- Serialized Form
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Constructor Summary
Constructors Constructor and Description KeyedCombineFnWithContext()
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method and Description abstract AccumT
addInput(K key, AccumT accumulator, InputT value, CombineWithContext.Context c)
Adds the given input value to the given accumulator, returning the new accumulator value.OutputT
apply(K key, Iterable<? extends InputT> inputs, CombineWithContext.Context c)
Applies thisKeyedCombineFnWithContext
to a key and a collection of input values to produce a combined output value.AccumT
compact(K key, AccumT accumulator, CombineWithContext.Context c)
Returns an accumulator that represents the same logical value as the input accumulator, but may have a more compact representation.abstract AccumT
createAccumulator(K key, CombineWithContext.Context c)
Returns a new, mutable accumulator value representing the accumulation of zero input values.abstract OutputT
extractOutput(K key, AccumT accumulator, CombineWithContext.Context c)
Returns the output value that is the result of combining all the input values represented by the given accumulator.CombineWithContext.CombineFnWithContext<InputT,AccumT,OutputT>
forKey(K key, Coder<K> keyCoder)
Returns the a regularCombineFnBase.GlobalCombineFn
that operates on a specific key.TypeVariable<?>
getAccumTVariable()
Returns theTypeVariable
ofAccumT
.Coder<AccumT>
getAccumulatorCoder(CoderRegistry registry, Coder<K> keyCoder, Coder<InputT> inputCoder)
Returns theCoder
to use for accumulatorAccumT
values, or null if it is not able to be inferred.Coder<OutputT>
getDefaultOutputCoder(CoderRegistry registry, Coder<K> keyCoder, Coder<InputT> inputCoder)
Returns theCoder
to use by default for outputOutputT
values, or null if it is not able to be inferred.TypeVariable<?>
getInputTVariable()
Returns theTypeVariable
ofInputT
.TypeVariable<?>
getKTypeVariable()
Returns theTypeVariable
ofK
.TypeVariable<?>
getOutputTVariable()
Returns theTypeVariable
ofOutputT
.abstract AccumT
mergeAccumulators(K key, Iterable<AccumT> 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.
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Method Detail
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createAccumulator
public abstract AccumT createAccumulator(K key, CombineWithContext.Context c)
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 toCombineWithContext.Context
.
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addInput
public abstract AccumT addInput(K key, AccumT accumulator, InputT value, CombineWithContext.Context c)
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 toCombineWithContext.Context
.
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mergeAccumulators
public abstract AccumT mergeAccumulators(K key, Iterable<AccumT> accumulators, CombineWithContext.Context c)
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 toCombineWithContext.Context
..
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extractOutput
public abstract OutputT extractOutput(K key, AccumT accumulator, CombineWithContext.Context c)
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 toCombineWithContext.Context
.
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compact
public AccumT compact(K key, AccumT accumulator, CombineWithContext.Context c)
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 toCombineWithContext.Context
.
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apply
public OutputT apply(K key, Iterable<? extends InputT> inputs, CombineWithContext.Context c)
Applies thisKeyedCombineFnWithContext
to a key and a collection of input values to produce a combined output value.
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forKey
public CombineWithContext.CombineFnWithContext<InputT,AccumT,OutputT> forKey(K key, Coder<K> keyCoder)
Description copied from interface:CombineFnBase.PerKeyCombineFn
Returns the a regularCombineFnBase.GlobalCombineFn
that operates on a specific key.
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getAccumulatorCoder
public Coder<AccumT> getAccumulatorCoder(CoderRegistry registry, Coder<K> keyCoder, Coder<InputT> inputCoder) throws CannotProvideCoderException
Description copied from interface:CombineFnBase.PerKeyCombineFn
Returns theCoder
to use for accumulatorAccumT
values, or null if it is not able to be inferred.By default, uses the knowledge of the
Coder
being used forK
keys and inputInputT
values and the enclosingPipeline
'sCoderRegistry
to try to infer the Coder forAccumT
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 interfaceCombineFnBase.PerKeyCombineFn<K,InputT,AccumT,OutputT>
- Throws:
CannotProvideCoderException
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getDefaultOutputCoder
public Coder<OutputT> getDefaultOutputCoder(CoderRegistry registry, Coder<K> keyCoder, Coder<InputT> inputCoder) throws CannotProvideCoderException
Description copied from interface:CombineFnBase.PerKeyCombineFn
Returns theCoder
to use by default for outputOutputT
values, or null if it is not able to be inferred.By default, uses the knowledge of the
Coder
being used forK
keys and inputInputT
values and the enclosingPipeline
'sCoderRegistry
to try to infer the Coder forOutputT
values.- Specified by:
getDefaultOutputCoder
in interfaceCombineFnBase.PerKeyCombineFn<K,InputT,AccumT,OutputT>
- Throws:
CannotProvideCoderException
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getKTypeVariable
public TypeVariable<?> getKTypeVariable()
Returns theTypeVariable
ofK
.
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getInputTVariable
public TypeVariable<?> getInputTVariable()
Returns theTypeVariable
ofInputT
.
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getAccumTVariable
public TypeVariable<?> getAccumTVariable()
Returns theTypeVariable
ofAccumT
.
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getOutputTVariable
public TypeVariable<?> getOutputTVariable()
Returns theTypeVariable
ofOutputT
.
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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 viaDisplayData.from(HasDisplayData)
. Implementations may callsuper.populateDisplayData(builder)
in order to register display data in the current namespace, but should otherwise usesubcomponent.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 interfaceHasDisplayData
- Parameters:
builder
- The builder to populate with display data.- See Also:
HasDisplayData
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