org.apache.flink.table.runtime.operators.window.tvf.common

Interface WindowProcessor<W>

All Superinterfaces:

Serializable

All Known Subinterfaces:

SlicingWindowProcessor<W>, UnslicingWindowProcessor<W>

All Known Implementing Classes:

AbstractSliceWindowAggProcessor, AbstractWindowAggProcessor, RowTimeWindowDeduplicateProcessor, SliceSharedWindowAggProcessor, SliceUnsharedWindowAggProcessor, UnsliceWindowAggProcessor, WindowRankProcessor

@Internal
public interface WindowProcessor<W>
extends Serializable

A processor that processes elements for windows.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	WindowProcessor.Context<W> Information available in an invocation of methods of WindowProcessor.

Method Summary

Modifier and Type	Method and Description
void	advanceProgress(long progress) Advances the progress time, the progress time is watermark if working in event-time mode, or current processing time if working in processing-time mode.
void	clearWindow(long timerTimestamp, W window) Clear state and resources associated with the given window namespace.
void	close() The tear-down method of the function.
org.apache.flink.api.common.typeutils.TypeSerializer<W>	createWindowSerializer() Returns the serializer of the window type.
void	fireWindow(long timerTimestamp, W window) Emit results of the given window.
void	initializeWatermark(long watermark) Initializes the watermark which restores from state.
void	open(WindowProcessor.Context<W> context) Initialization method for the function.
void	prepareCheckpoint() Performs a preparation before checkpoint.
boolean	processElement(org.apache.flink.table.data.RowData key, org.apache.flink.table.data.RowData element) Process an element with associated key from the input stream.

Method Detail

open

void open(WindowProcessor.Context<W> context)
   throws Exception

Initialization method for the function. It is called before the actual working methods.

Throws:

Exception

initializeWatermark

void initializeWatermark(long watermark)

Initializes the watermark which restores from state. The method is called after open method and before the actual working methods.

Parameters:

watermark - the initial watermark

processElement

boolean processElement(org.apache.flink.table.data.RowData key,
                       org.apache.flink.table.data.RowData element)
                throws Exception

Process an element with associated key from the input stream. Returns true if this element is dropped because of late arrival.

Parameters:

key - the key associated with the element

element - The element to process.

Throws:

Exception

advanceProgress

void advanceProgress(long progress)
              throws Exception

Advances the progress time, the progress time is watermark if working in event-time mode, or current processing time if working in processing-time mode.

This will potentially flush buffered data into states, because the watermark advancement may be in a very small step, but we don't need to flush buffered data for every watermark advancement.

Parameters:

progress - the current progress time

Throws:

Exception

prepareCheckpoint

void prepareCheckpoint()
                throws Exception

Performs a preparation before checkpoint. This usually flushes buffered data into state.

Throws:

Exception

fireWindow

void fireWindow(long timerTimestamp,
                W window)
         throws Exception

Emit results of the given window.

Note: the key context has been set.

Parameters:

timerTimestamp - the fired timestamp

window - the window to emit

Throws:

Exception

clearWindow

void clearWindow(long timerTimestamp,
                 W window)
          throws Exception

Clear state and resources associated with the given window namespace.

Note: the key context has been set.

Parameters:

timerTimestamp - the fired timestamp

window - the window to clear

Throws:

Exception

close

void close()
    throws Exception

The tear-down method of the function. It is called after the last call to the main working methods.

Throws:

Exception

createWindowSerializer

org.apache.flink.api.common.typeutils.TypeSerializer<W> createWindowSerializer()

Returns the serializer of the window type.