Thanks a lot for the KIP Ray!
It seems to be a good improvement to make using KS with Clojure more
seamless.
However, I am not 100% sure if all listed interfaces make sense?
(100) GlobalKTable: it's basically a sibling to `KStream`, and `KTable`
interfaces, but users would never implemented it, and thus I think it
won't make much sense to add the annotation. Playing devils advocate, it
could even be "harmful" as it might provide a wrong signal to users that
this interface would be intended to be implemented by them.
(200) NamedOperation: this is some helper interface that user also won't
need to implement. I am less worried about being harmful (as I am for
GlobalKTable), but I also don't see much of an advantage.
(300) TransformerSupplier and ValueTransformerSupplier: both are going
to be deprecate with 4.0, which is only a side cleanup anyway. Both can
only be used with `KStream.transform()`, `.flatTransform()`,
`.transformValues()` and `.flatTransformValues()` and all four method
will be removed in 4.0 rending both interface practically useless. -- No
damage to include them, but also not useful.
(400) ProcessorSupplier and Processor: there is currently two interfaces
with each name, the old and already deprecated interfaces
`...processor.Processor[Supplier]` and the new
`...processor.api.Processor[Supplier]`. The KIP should be explicit and
say `api.Proceccor[Supplier]` as only the new interfaces have annotation
already, but not the old ones. - The old interfaces do also not need to
be updated IMHO, as will we remove both with 4.0, too.
(410) There is also two interfaces `...processor.ProcessorContext` and
`...processor.api.ProcessorContext`. Both are still in used, and thus
the KIP should mention both explicitly.
(500) I am not sure if the KIP need to explicitly list all interface it
does not update... It's a long list and it might be easier to read the
KIP if omitted?
(600) There is some other interface/abstract-classes which might benefit
from the annotation, too:
- org.apache.kafka.streams.errors:
DeserializationExceptionHandler (does not qualify now, but we could
include it in the KIP and file a follow up ticket for the future to add
it, when we remove the deprecated method? -- This would avoid the need
for another KIP in the future)
StreamsUncaughtExceptionHandler
- org.apache.kafka.streams.processor.api:
ContextualFixedKeyProcessor
ContextualProcessor
- org.apache.kafka.streams.processor:
CommitCallback
Punctuator
StateRestoreCallback
StreamPartitioner (there is already a open PR to remove the
deprecate method so it will qualify in 4.0 release)
TimestampExtractor
TopicNameExtractor
-Matthias
On 7/29/24 12:47 AM, Ray McDermott wrote:
These annotations assist with clarifying the purpose of the interface, as well
as assisting interop with non-Java JVM languages.
https://cwiki.apache.org/confluence/display/KAFKA/KIP-1072%3A+Add+@FunctionalInterface+annotation+to+Kafka+Streams+SAM+methods
Comments welcome
Thanks
Ray
