Package com.hazelcast.jet.core

Class Watermark

java.lang.Object
com.hazelcast.jet.core.Watermark
All Implemented Interfaces:
com.hazelcast.jet.impl.execution.BroadcastItem, com.hazelcast.jet.impl.execution.SpecialBroadcastItem
public final class Watermark extends Object implements com.hazelcast.jet.impl.execution.SpecialBroadcastItem
Watermark is an item occasionally inserted into a disordered (sub)stream of timestamped items. The watermark's timestamp value has the meaning "no items will follow with timestamp less than this." The value of the watermark is always monotonically increasing in the (sub)stream, with the effect of superimposing an ordered timestamp sequence over the original disordered one. Watermark items are used by windowing processors as anchoring points where the processor knows which windows it can close and emit their aggregated results.
Since:
Jet 3.0

  • Constructor Summary

    Constructors
    Constructor
    Description
    Watermark(long timestamp)
    Constructs a new watermark item with 0 watermark key.
    Watermark(long timestamp, byte key)
    Constructs a new watermark item with specified key.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    equals(Object o)
     
    int
    hashCode()
     
    byte
    key()
    Returns the key of this watermark item.
    long
    timestamp()
    Returns the timestamp of this watermark item.
    String
    toString()
     

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • Watermark

      public Watermark(long timestamp)
      Constructs a new watermark item with 0 watermark key.

    • Watermark

      public Watermark(long timestamp, byte key)
      Constructs a new watermark item with specified key.

  • Method Details

    • timestamp

      public long timestamp()
      Returns the timestamp of this watermark item.

    • key

      public byte key()
      Returns the key of this watermark item.

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object