org.apache.kafka.streams.kstream

Class UnlimitedWindows

java.lang.Object

org.apache.kafka.streams.kstream.Windows<UnlimitedWindow>

org.apache.kafka.streams.kstream.UnlimitedWindows

@InterfaceStability.Unstable
public final class UnlimitedWindows
extends Windows<UnlimitedWindow>

The unlimited window specifications used for aggregations.

An unlimited time window is also called landmark window. It has a fixed starting point while its window end is defined as infinite. With this regard, it is a fixed-size window with infinite window size.

For time semantics, see TimestampExtractor.

See Also:

TimeWindows, SessionWindows, JoinWindows, KGroupedStream.count(Windows, String), KGroupedStream.count(Windows, org.apache.kafka.streams.processor.StateStoreSupplier), KGroupedStream.reduce(Reducer, Windows, String), KGroupedStream.reduce(Reducer, Windows, org.apache.kafka.streams.processor.StateStoreSupplier), KGroupedStream.aggregate(Initializer, Aggregator, Windows, org.apache.kafka.common.serialization.Serde, String), KGroupedStream.aggregate(Initializer, Aggregator, Windows, org.apache.kafka.streams.processor.StateStoreSupplier), TimestampExtractor

Field Summary

Fields

Modifier and Type	Field and Description
long	startMs The start timestamp of the window.

Fields inherited from class org.apache.kafka.streams.kstream.Windows

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Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o)
int	hashCode()
long	maintainMs() Return the window maintain duration (retention time) in milliseconds.
static UnlimitedWindows	of() Return an unlimited window starting at timestamp zero.
long	size() Return the size of the specified windows in milliseconds.
UnlimitedWindows	startOn(long startMs) Return a new unlimited window for the specified start timestamp.
UnlimitedWindows	until(long durationMs) Throws an IllegalArgumentException because the retention time for unlimited windows is always infinite and cannot be changed.
Map<Long,UnlimitedWindow>	windowsFor(long timestamp) Create all windows that contain the provided timestamp, indexed by non-negative window start timestamps.

Methods inherited from class org.apache.kafka.streams.kstream.Windows

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Methods inherited from class java.lang.Object

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

Field Detail

startMs

public final long startMs

The start timestamp of the window.

Method Detail

of

public static UnlimitedWindows of()

Return an unlimited window starting at timestamp zero.

startOn

public UnlimitedWindows startOn(long startMs)
                         throws IllegalArgumentException

Return a new unlimited window for the specified start timestamp.

Parameters:

startMs - the window start time

Returns:

a new unlimited window that starts at startMs

Throws:

IllegalArgumentException - if the start time is negative

windowsFor

public Map<Long,UnlimitedWindow> windowsFor(long timestamp)

Description copied from class: Windows

Create all windows that contain the provided timestamp, indexed by non-negative window start timestamps.

Specified by:

windowsFor in class Windows<UnlimitedWindow>

Parameters:

timestamp - the timestamp window should get created for

Returns:

a map of windowStartTimestamp -> Window entries

size

public long size()

Return the size of the specified windows in milliseconds. As unlimited windows have conceptually infinite size, this methods just returns Long.MAX_VALUE.

Specified by:

size in class Windows<UnlimitedWindow>

Returns:

the size of the specified windows which is Long.MAX_VALUE

until

public UnlimitedWindows until(long durationMs)

Throws an IllegalArgumentException because the retention time for unlimited windows is always infinite and cannot be changed.

Overrides:

until in class Windows<UnlimitedWindow>

Parameters:

durationMs - the window retention time in milliseconds

Returns:

itself

Throws:

IllegalArgumentException - on every invocation

maintainMs

public long maintainMs()

Return the window maintain duration (retention time) in milliseconds. The retention time for unlimited windows in infinite and thus represented as Long.MAX_VALUE.

Overrides:

maintainMs in class Windows<UnlimitedWindow>

Returns:

the window retention time that is Long.MAX_VALUE

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object