org.apache.flink.table.runtime.operators.window.slicing

Interface SliceAssigner

All Superinterfaces:

Serializable

All Known Subinterfaces:

SliceSharedAssigner, SliceUnsharedAssigner

All Known Implementing Classes:

SliceAssigners.CumulativeSliceAssigner, SliceAssigners.HoppingSliceAssigner, SliceAssigners.SlicedSharedSliceAssigner, SliceAssigners.SlicedUnsharedSliceAssigner, SliceAssigners.TumblingSliceAssigner, SliceAssigners.WindowedSliceAssigner

@Internal
public interface SliceAssigner
extends Serializable

A SliceAssigner assigns element into a single slice. Note that we use the slice end timestamp to identify a slice.

Note: SliceAssigner servers as a base interface. Concrete assigners should implement interface SliceSharedAssigner or SliceUnsharedAssigner.

See Also:

for more definition of slice.

Method Summary

Modifier and Type	Method and Description
long	assignSliceEnd(RowData element, ClockService clock) Returns the end timestamp of a slice that the given element should belong.
Iterable<Long>	expiredSlices(long windowEnd) Returns an iterator of slices to expire when the given window is emitted.
long	getLastWindowEnd(long sliceEnd) Returns the last window which the slice belongs to.
long	getSliceEndInterval() Returns the interval of slice ends, i.e.
long	getWindowStart(long windowEnd) Returns the corresponding window start timestamp of the given window end timestamp.
boolean	isEventTime() Returns true if elements are assigned to windows based on event time, false based on processing time.

Method Detail

assignSliceEnd

long assignSliceEnd(RowData element,
                    ClockService clock)

Returns the end timestamp of a slice that the given element should belong.

Parameters:

element - the element to which slice should belong to.

clock - the service to get current processing time.

getLastWindowEnd

long getLastWindowEnd(long sliceEnd)

Returns the last window which the slice belongs to. The window and and slices are both identified by the end timestamp.

getWindowStart

long getWindowStart(long windowEnd)

Returns the corresponding window start timestamp of the given window end timestamp.

expiredSlices

Iterable<Long> expiredSlices(long windowEnd)

Returns an iterator of slices to expire when the given window is emitted. The window and slices are both identified by the end timestamp.

Parameters:

windowEnd - the end timestamp of window emitted.

getSliceEndInterval

long getSliceEndInterval()

Returns the interval of slice ends, i.e. the step size to advance of the slice end when a new slice assigned.

isEventTime

boolean isEventTime()

Returns true if elements are assigned to windows based on event time, false based on processing time.