org.apache.beam.sdk.io

Class CountingInput.UnboundedCountingInput

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PBegin,PCollection<Long>>

org.apache.beam.sdk.io.CountingInput.UnboundedCountingInput

All Implemented Interfaces:

Serializable, HasDisplayData

Enclosing class:

CountingInput

public static class CountingInput.UnboundedCountingInput
extends PTransform<PBegin,PCollection<Long>>

A PTransform that will produce numbers starting from 0 up to Long.MAX_VALUE.

After Long.MAX_VALUE, the transform never produces more output. (In practice, this limit should never be reached.)

Elements in the resulting PCollection<Long> will by default have timestamps corresponding to processing time at element generation, provided by Instant.now(). Use the transform returned by withTimestampFn(SerializableFunction) to control the output timestamps.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

name

Method Summary

Modifier and Type	Method and Description
PCollection<Long>	apply(PBegin begin) Applies this PTransform on the given InputT, and returns its Output.
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.
CountingInput.UnboundedCountingInput	withMaxNumRecords(long maxRecords) Returns an CountingInput.UnboundedCountingInput like this one, but that will read at most the specified number of elements.
CountingInput.UnboundedCountingInput	withMaxReadTime(Duration readTime) Returns an CountingInput.UnboundedCountingInput like this one, but that will read for at most the specified amount of time.
CountingInput.UnboundedCountingInput	withRate(long numElements, Duration periodLength) Returns an CountingInput.UnboundedCountingInput like this one, but with output production limited to an aggregate rate of no more than the number of elements per the period length.
CountingInput.UnboundedCountingInput	withTimestampFn(SerializableFunction<Long,Instant> timestampFn) Returns an CountingInput.UnboundedCountingInput like this one, but where output elements have the timestamp specified by the timestampFn.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, toString, validate

Methods inherited from class java.lang.Object

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

Method Detail

withTimestampFn

public CountingInput.UnboundedCountingInput withTimestampFn(SerializableFunction<Long,Instant> timestampFn)

Returns an CountingInput.UnboundedCountingInput like this one, but where output elements have the timestamp specified by the timestampFn.

Note that the timestamps produced by timestampFn may not decrease.

withMaxNumRecords

public CountingInput.UnboundedCountingInput withMaxNumRecords(long maxRecords)

Returns an CountingInput.UnboundedCountingInput like this one, but that will read at most the specified number of elements.

A bounded amount of elements will be produced by the result transform, and the result PCollection will be bounded.

withRate

public CountingInput.UnboundedCountingInput withRate(long numElements,
                                                     Duration periodLength)

Returns an CountingInput.UnboundedCountingInput like this one, but with output production limited to an aggregate rate of no more than the number of elements per the period length.

Note that when there are multiple splits, each split outputs independently. This may lead to elements not being produced evenly across time, though the aggregate rate will still approach the specified rate.

A duration of Duration.ZERO will produce output as fast as possible.

withMaxReadTime

public CountingInput.UnboundedCountingInput withMaxReadTime(Duration readTime)

Returns an CountingInput.UnboundedCountingInput like this one, but that will read for at most the specified amount of time.

A bounded amount of elements will be produced by the result transform, and the result PCollection will be bounded.

apply

public PCollection<Long> apply(PBegin begin)

Description copied from class: PTransform

Applies this PTransform on the given InputT, and returns its Output.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

apply in class PTransform<PBegin,PCollection<Long>>

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Description copied from class: PTransform

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

Overrides:

populateDisplayData in class PTransform<PBegin,PCollection<Long>>

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData