OutputTimeFns (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. After August 12, 2020, Dataflow will not run jobs using Dataflow 1.x and below. 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.transforms.windowing

Class OutputTimeFns

• java.lang.Object
• • com.google.cloud.dataflow.sdk.transforms.windowing.OutputTimeFns

• ---

  
  

  @Experimental(value=OUTPUT_TIME)
  public class OutputTimeFns
  extends Object

  (Experimental) Static utility methods and provided implementations for OutputTimeFn.

• • Constructor Summary

    Constructors 

    Constructor and Description
    OutputTimeFns()

  • Method Summary

    All Methods Static Methods Concrete Methods 

    Modifier and Type	Method and Description
    static Instant	combineOutputTimes(OutputTimeFn<?> outputTimeFn, Iterable<? extends Instant> outputTimes) Applies the given OutputTimeFn to the given output times, obtaining the output time for a value computed.
    static OutputTimeFn<BoundedWindow>	outputAtEarliestInputTimestamp() The policy of outputting at the earliest of the input timestamps for non-late input data that led to a computed value.
    static OutputTimeFn<BoundedWindow>	outputAtEndOfWindow() The policy of outputting with timestamps at the end of the window.
    static OutputTimeFn<BoundedWindow>	outputAtLatestInputTimestamp() The policy of holding the watermark to the latest of the input timestamps for non-late input data that led to a computed value.

    • Methods inherited from class java.lang.Object

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

• • Constructor Detail

    • OutputTimeFns

      public OutputTimeFns()

  • Method Detail

    • outputAtEarliestInputTimestamp

      public static OutputTimeFn<BoundedWindow> outputAtEarliestInputTimestamp()

      The policy of outputting at the earliest of the input timestamps for non-late input data that led to a computed value.

      For example, suppose v₁ through v_n are all on-time elements being aggregated via some function f into f(v₁, ..., v_n. When emitted, the output timestamp of the result will be the earliest of the event time timestamps

      If data arrives late, it has no effect on the output timestamp.

    • outputAtLatestInputTimestamp

      public static OutputTimeFn<BoundedWindow> outputAtLatestInputTimestamp()

      The policy of holding the watermark to the latest of the input timestamps for non-late input data that led to a computed value.

      For example, suppose v₁ through v_n are all on-time elements being aggregated via some function f into f(v₁, ..., v_n. When emitted, the output timestamp of the result will be the latest of the event time timestamps

      If data arrives late, it has no effect on the output timestamp.

    • outputAtEndOfWindow

      public static OutputTimeFn<BoundedWindow> outputAtEndOfWindow()

      The policy of outputting with timestamps at the end of the window.

      Note that this output timestamp depends only on the window. See dependsOnlyOnWindow().

      When windows merge, instead of using OutputTimeFn.combine(org.joda.time.Instant, org.joda.time.Instant) to obtain an output timestamp for the results in the new window, it is mandatory to obtain a new output timestamp from OutputTimeFn.assignOutputTime(org.joda.time.Instant, W) with the new window and an arbitrary timestamp (because it is guaranteed that the timestamp is irrelevant).

      For non-merging window functions, this OutputTimeFn works transparently.

    • combineOutputTimes

      public static Instant combineOutputTimes(OutputTimeFn<?> outputTimeFn,
                                               Iterable<? extends Instant> outputTimes)

      Applies the given OutputTimeFn to the given output times, obtaining the output time for a value computed. See OutputTimeFn.combine(org.joda.time.Instant, org.joda.time.Instant) for a full specification.

      Throws:

      IllegalArgumentException - if outputTimes is empty.