com.google.cloud.dataflow.sdk.transforms

Class Sample.FixedSizedSampleFn<T>

java.lang.Object

com.google.cloud.dataflow.sdk.transforms.Combine.CombineFn<T,com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap,java.lang.Iterable<T>>

com.google.cloud.dataflow.sdk.transforms.Sample.FixedSizedSampleFn<T>

Type Parameters:

T - the type of the elements

All Implemented Interfaces:

java.io.Serializable

Enclosing class:

Sample

public static class Sample.FixedSizedSampleFn<T>
extends Combine.CombineFn<T,com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap,java.lang.Iterable<T>>

CombineFn that computes a fixed-size sample of a collection of values.

See Also:

Serialized Form

Method Summary

Methods

Modifier and Type	Method and Description
void	addInput(com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap accumulator, T input) Adds the given input value to the given accumulator, modifying the accumulator.
com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap	createAccumulator() Returns a new, mutable accumulator value, representing the accumulation of zero input values.
java.lang.Iterable<T>	extractOutput(com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap accumulator) Returns the output value that is the result of combining all the input values represented by the given accumulator.
Coder<com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap>	getAccumulatorCoder(CoderRegistry registry, Coder<T> inputCoder) Returns the Coder to use for accumulator VA values, or null if it is not able to be inferred.
Coder<java.lang.Iterable<T>>	getDefaultOutputCoder(CoderRegistry registry, Coder<T> inputCoder) Returns the Coder to use by default for output VO values, or null if it is not able to be inferred.
com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap	mergeAccumulators(java.lang.Iterable<com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap> accumulators) Returns an accumulator representing the accumulation of all the input values accumulated in the merging accumulators.

Methods inherited from class com.google.cloud.dataflow.sdk.transforms.Combine.CombineFn

apply, asKeyedFn

Methods inherited from class java.lang.Object

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

Method Detail

createAccumulator

public com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap 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<T,com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap,java.lang.Iterable<T>>

addInput

public void addInput(com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap accumulator,
            T input)

Description copied from class: Combine.CombineFn

Adds the given input value to the given accumulator, modifying the accumulator.

Specified by:

addInput in class Combine.CombineFn<T,com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap,java.lang.Iterable<T>>

mergeAccumulators

public com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap mergeAccumulators(java.lang.Iterable<com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap> accumulators)

Description copied from class: Combine.CombineFn

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

May modify any of the argument accumulators. May return a fresh accumulator, or may return one of the (modified) argument accumulators.

Specified by:

mergeAccumulators in class Combine.CombineFn<T,com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap,java.lang.Iterable<T>>

extractOutput

public java.lang.Iterable<T> extractOutput(com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap 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<T,com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap,java.lang.Iterable<T>>

getAccumulatorCoder

public Coder<com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap> getAccumulatorCoder(CoderRegistry registry,
                                                                                        Coder<T> inputCoder)

Description copied from class: Combine.CombineFn

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

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

Overrides:

getAccumulatorCoder in class Combine.CombineFn<T,com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap,java.lang.Iterable<T>>

getDefaultOutputCoder

public Coder<java.lang.Iterable<T>> getDefaultOutputCoder(CoderRegistry registry,
                                                 Coder<T> inputCoder)

Description copied from class: Combine.CombineFn

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

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

Overrides:

getDefaultOutputCoder in class Combine.CombineFn<T,com.google.cloud.dataflow.sdk.transforms.Top.TopCombineFn.Heap,java.lang.Iterable<T>>