T
- The type of the elements that this function can extract timestamps from@PublicEvolving public abstract class AscendingTimestampExtractor<T> extends Object implements AssignerWithPeriodicWatermarks<T>
Modifier and Type | Class and Description |
---|---|
static class |
AscendingTimestampExtractor.FailingHandler
Handler that fails the program when timestamp monotony is violated.
|
static class |
AscendingTimestampExtractor.IgnoringHandler
Handler that does nothing when timestamp monotony is violated.
|
static class |
AscendingTimestampExtractor.LoggingHandler
Handler that only logs violations of timestamp monotony, on WARN log level.
|
static interface |
AscendingTimestampExtractor.MonotonyViolationHandler
Interface for handlers that handle violations of the monotonous ascending timestamps
property.
|
Constructor and Description |
---|
AscendingTimestampExtractor() |
Modifier and Type | Method and Description |
---|---|
abstract long |
extractAscendingTimestamp(T element)
Extracts the timestamp from the given element.
|
long |
extractTimestamp(T element,
long elementPrevTimestamp)
Assigns a timestamp to an element, in milliseconds since the Epoch.
|
Watermark |
getCurrentWatermark()
Returns the current watermark.
|
AscendingTimestampExtractor<T> |
withViolationHandler(AscendingTimestampExtractor.MonotonyViolationHandler handler)
Sets the handler for violations to the ascending timestamp order.
|
public abstract long extractAscendingTimestamp(T element)
element
- The element that the timestamp is extracted from.public AscendingTimestampExtractor<T> withViolationHandler(AscendingTimestampExtractor.MonotonyViolationHandler handler)
handler
- The violation handler to use.public final long extractTimestamp(T element, long elementPrevTimestamp)
TimestampAssigner
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
.
extractTimestamp
in interface TimestampAssigner<T>
element
- The element that the timestamp is wil be assigned to.elementPrevTimestamp
- The previous internal timestamp of the element,
or a negative value, if no timestamp has been assigned, yet.public final Watermark getCurrentWatermark()
AssignerWithPeriodicWatermarks
null
to
indicate that no new Watermark is available.
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 the current watermark is still identical to the previous one, no progress in event time has happened since the previous call to this method. 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.
The interval in which this method is called and Watermarks are generated
depends on ExecutionConfig.getAutoWatermarkInterval()
.
getCurrentWatermark
in interface AssignerWithPeriodicWatermarks<T>
Null
, if no watermark should be emitted, or the next watermark to emit.Watermark
,
ExecutionConfig.getAutoWatermarkInterval()
Copyright © 2014–2017 The Apache Software Foundation. All rights reserved.