org.apache.flink.table.runtime.operators.wmassigners

Class PunctuatedWatermarkAssignerWrapper

java.lang.Object

org.apache.flink.table.runtime.operators.wmassigners.PunctuatedWatermarkAssignerWrapper

All Implemented Interfaces:

Serializable, TimestampAssigner<RowData>, Function, AssignerWithPunctuatedWatermarks<RowData>

@Internal
public class PunctuatedWatermarkAssignerWrapper
extends Object
implements AssignerWithPunctuatedWatermarks<RowData>

Generates periodic watermarks based on a PunctuatedWatermarkAssigner.

See Also:

Serialized Form

Field Summary

Fields inherited from interface org.apache.flink.api.common.eventtime.TimestampAssigner

NO_TIMESTAMP

Constructor Summary

Constructors

Constructor and Description
PunctuatedWatermarkAssignerWrapper(PunctuatedWatermarkAssigner assigner, int timeFieldIdx, DataType sourceType)

Method Summary

Modifier and Type	Method and Description
Watermark	checkAndGetNextWatermark(RowData row, long extractedTimestamp) Asks this implementation if it wants to emit a watermark.
long	extractTimestamp(RowData element, long recordTimestamp) Assigns a timestamp to an element, in milliseconds since the Epoch.

Methods inherited from class java.lang.Object

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

Constructor Detail

PunctuatedWatermarkAssignerWrapper

public PunctuatedWatermarkAssignerWrapper(PunctuatedWatermarkAssigner assigner,
                                          int timeFieldIdx,
                                          DataType sourceType)

Parameters:

timeFieldIdx - the index of the rowtime attribute.

assigner - the watermark assigner.

sourceType - the type of source

Method Detail

checkAndGetNextWatermark

@Nullable
public Watermark checkAndGetNextWatermark(RowData row,
                                                    long extractedTimestamp)

Description copied from interface: AssignerWithPunctuatedWatermarks

Asks this implementation if it wants to emit a watermark. This method is called right after the TimestampAssigner.extractTimestamp(Object, long) method.

The returned watermark will be emitted only if it is non-null and its timestamp is larger than that of the previously emitted watermark (to preserve the contract of ascending watermarks). If a null value is returned, or the timestamp of the returned watermark is smaller than that of the last emitted one, then no new watermark will be generated.

For an example how to use this method, see the documentation of this class.

Specified by:

checkAndGetNextWatermark in interface AssignerWithPunctuatedWatermarks<RowData>

Returns:

Null, if no watermark should be emitted, or the next watermark to emit.

extractTimestamp

public long extractTimestamp(RowData element,
                             long recordTimestamp)

Description copied from interface: TimestampAssigner

Assigns a timestamp to an element, in milliseconds since the Epoch.

The method is passed the previously assigned timestamp of the element. That previous timestamp may have been assigned from a previous assigner, by ingestion time. If the element did not carry a timestamp before, this value is Long.MIN_VALUE.

Specified by:

extractTimestamp in interface TimestampAssigner<RowData>

Parameters:

element - The element that the timestamp will be assigned to.

recordTimestamp - The previous internal timestamp of the element, or a negative value, if no timestamp has been assigned yet.

Returns:

The new timestamp.