T
- type of element being comparedpublic static class Top.TopCombineFn<T,ComparatorT extends java.util.Comparator<T> & java.io.Serializable> extends Combine.AccumulatingCombineFn<T,org.apache.beam.sdk.transforms.Top.BoundedHeap<T,ComparatorT>,java.util.List<T>> implements org.apache.beam.sdk.util.NameUtils.NameOverride
CombineFn
for Top
transforms that combines a bunch of T
s into a single
count
-long List<T>
, using compareFn
to choose the largest T
s.Combine.AccumulatingCombineFn.Accumulator<InputT,AccumT,OutputT>
Constructor and Description |
---|
TopCombineFn(int count,
ComparatorT compareFn) |
Modifier and Type | Method and Description |
---|---|
org.apache.beam.sdk.transforms.Top.BoundedHeap<T,ComparatorT> |
createAccumulator()
Returns a new, mutable accumulator value, representing the accumulation of zero input values.
|
java.lang.reflect.TypeVariable<?> |
getAccumTVariable()
Returns the
TypeVariable of AccumT . |
Coder<org.apache.beam.sdk.transforms.Top.BoundedHeap<T,ComparatorT>> |
getAccumulatorCoder(CoderRegistry registry,
Coder<T> 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.String |
getNameOverride() |
java.lang.reflect.TypeVariable<?> |
getOutputTVariable()
Returns the
TypeVariable of OutputT . |
void |
populateDisplayData(DisplayData.Builder builder)
Register display data for the given transform or component.
|
addInput, extractOutput, mergeAccumulators
apply, compact, defaultValue, getInputType, getOutputType
public TopCombineFn(int count, ComparatorT compareFn)
public java.lang.String getNameOverride()
getNameOverride
in interface org.apache.beam.sdk.util.NameUtils.NameOverride
public org.apache.beam.sdk.transforms.Top.BoundedHeap<T,ComparatorT> createAccumulator()
Combine.CombineFn
createAccumulator
in class Combine.CombineFn<T,org.apache.beam.sdk.transforms.Top.BoundedHeap<T,ComparatorT extends java.util.Comparator<T> & java.io.Serializable>,java.util.List<T>>
public Coder<org.apache.beam.sdk.transforms.Top.BoundedHeap<T,ComparatorT>> getAccumulatorCoder(CoderRegistry registry, Coder<T> inputCoder)
CombineFnBase.GlobalCombineFn
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.
getAccumulatorCoder
in interface CombineFnBase.GlobalCombineFn<T,org.apache.beam.sdk.transforms.Top.BoundedHeap<T,ComparatorT extends java.util.Comparator<T> & java.io.Serializable>,java.util.List<T>>
public void populateDisplayData(DisplayData.Builder builder)
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.
populateDisplayData
in interface HasDisplayData
builder
- The builder to populate with display data.HasDisplayData
public java.lang.String getIncompatibleGlobalWindowErrorMessage()
CombineFnBase.GlobalCombineFn
getIncompatibleGlobalWindowErrorMessage
in interface CombineFnBase.GlobalCombineFn<T,org.apache.beam.sdk.transforms.Top.BoundedHeap<T,ComparatorT extends java.util.Comparator<T> & java.io.Serializable>,java.util.List<T>>
public Coder<OutputT> getDefaultOutputCoder(CoderRegistry registry, Coder<InputT> inputCoder) throws CannotProvideCoderException
CombineFnBase.GlobalCombineFn
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.
getDefaultOutputCoder
in interface CombineFnBase.GlobalCombineFn<InputT,AccumT,OutputT>
CannotProvideCoderException
public java.lang.reflect.TypeVariable<?> getInputTVariable()
TypeVariable
of InputT
.public java.lang.reflect.TypeVariable<?> getAccumTVariable()
TypeVariable
of AccumT
.public java.lang.reflect.TypeVariable<?> getOutputTVariable()
TypeVariable
of OutputT
.