org.apache.beam.sdk.transforms.windowing

Class BoundedWindow

java.lang.Object

org.apache.beam.sdk.transforms.windowing.BoundedWindow

Direct Known Subclasses:

GlobalWindow, IntervalWindow

public abstract class BoundedWindow
extends java.lang.Object

A BoundedWindow represents a finite grouping of elements, with an upper bound (larger timestamps represent more recent data) on the timestamps of elements that can be placed in the window. This finiteness means that for every window, at some point in time, all data for that window will have arrived and can be processed together.

Windows must also implement Object.equals(java.lang.Object) and Object.hashCode() such that windows that are logically equal will be treated as equal by equals() and hashCode().

Field Summary

Fields

Modifier and Type	Field and Description
static Instant	TIMESTAMP_MAX_VALUE The maximum value for any Beam timestamp.
static Instant	TIMESTAMP_MIN_VALUE The minimum value for any Beam timestamp.

Constructor Summary

Constructors

Constructor and Description
BoundedWindow()

Method Summary

Modifier and Type	Method and Description
static java.lang.String	formatTimestamp(Instant timestamp) Formats a Instant timestamp with additional Beam-specific metadata, such as indicating whether the timestamp is the end of the global window or one of the distinguished values TIMESTAMP_MIN_VALUE or TIMESTAMP_MIN_VALUE.
abstract Instant	maxTimestamp() Returns the inclusive upper bound of timestamps for values in this window.

Methods inherited from class java.lang.Object

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

Field Detail

TIMESTAMP_MIN_VALUE

public static final Instant TIMESTAMP_MIN_VALUE

The minimum value for any Beam timestamp. Often referred to as "-infinity".

This value and TIMESTAMP_MAX_VALUE are chosen so that their microseconds-since-epoch can be safely represented with a long.

TIMESTAMP_MAX_VALUE

public static final Instant TIMESTAMP_MAX_VALUE

The maximum value for any Beam timestamp. Often referred to as "+infinity".

This value and TIMESTAMP_MIN_VALUE are chosen so that their microseconds-since-epoch can be safely represented with a long.

Constructor Detail

BoundedWindow

public BoundedWindow()

Method Detail

formatTimestamp

public static java.lang.String formatTimestamp(Instant timestamp)

Formats a Instant timestamp with additional Beam-specific metadata, such as indicating whether the timestamp is the end of the global window or one of the distinguished values TIMESTAMP_MIN_VALUE or TIMESTAMP_MIN_VALUE.

maxTimestamp

public abstract Instant maxTimestamp()

Returns the inclusive upper bound of timestamps for values in this window.