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 and 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 and 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 Detail

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 Detail

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