CountingInput.UnboundedCountingInput (Google Cloud Dataflow SDK 1.9.1 API)

Google Cloud Dataflow SDK for Java, version 1.9.1

Warning: Dataflow SDK 1.x for Java is unsupported as of October 16, 2018. See Migrating from Dataflow SDK 1.x for Java for migration guidance.

Note: If you are using Cloud Dataflow SDK version 2.x, see the Apache Beam API reference documentation.

com.google.cloud.dataflow.sdk.io

Class CountingInput.UnboundedCountingInput

• java.lang.Object
• • com.google.cloud.dataflow.sdk.transforms.PTransform<PBegin,PCollection<Long>>
  • • com.google.cloud.dataflow.sdk.io.CountingInput.UnboundedCountingInput

• All Implemented Interfaces:

  HasDisplayData, Serializable

  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 com.google.cloud.dataflow.sdk.transforms.PTransform

      name

  • Method Summary

    All Methods Instance Methods Concrete Methods 

    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 com.google.cloud.dataflow.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).

      The default implementation throws an exception. A derived class must either implement apply, or else each runner must supply a custom implementation via PipelineRunner.apply(com.google.cloud.dataflow.sdk.transforms.PTransform<InputT, OutputT>, InputT).

      Overrides:

      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