Hi Sagar,
I do not see an issue with using an empty list together with an empty
Optional. A non-empty Optional that contains an empty list would just
say that there is no partition to which the record should be sent. If
there is no partition, the record is dropped.
An empty Optional might be a way to say, broadcast to all partitions.
Alternatively -- to make it more explicit -- you could return an object
with an enum and a list of partitions. The enum could have values SOME,
ALL, and NONE. If the value is SOME, the list of partitions contains the
partitions to which to send the record. If the value of the enum is ALL
or NONE, the list of partitions is not used and might be even null
(since in that case the list should not be used and it would be a bug to
use it).
Best,
Bruno
On 24.08.22 20:11, Sagar wrote:
Thank you Bruno/Matthew for your comments.
I agree using null does seem error prone. However I think using a singleton
list of [-1] might be better in terms of usability, I am saying this
because the KIP also has a provision to return an empty list to refer to
dropping the record. So, an empty optional and an empty list have totally
different meanings which could get confusing.
Let me know what you think.
Thanks!
Sagar.
On Wed, Aug 24, 2022 at 7:30 PM Matthew Benedict de Detrich
<matthew.dedetr...@aiven.io.invalid> wrote:
I also concur with this, having an Optional in the type makes it very
clear what’s going on and better signifies an absence of value (or in this
case the broadcast value).
--
Matthew de Detrich
Aiven Deutschland GmbH
Immanuelkirchstraße 26, 10405 Berlin
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On 24. Aug 2022, 14:19 +0200, dev@kafka.apache.org, wrote:
2.
I would prefer changing the return type of partitions() to
Optional<List<Integer>> and using Optional.empty() as the broadcast
value. IMO, The chances that an implementation returns null due to a bug
is much higher than that an implementation returns an empty Optional due
to a bug.
