KAFKA-16433: BeginningAndEndOffsets and OffsetsForTimes should send an event and return empty with zero timeout provided

[philipnee]

beginningOrEndOffset and offsetforTimes should send a ListOffsetEvent and return empty results if the provided timeout is zero.

A minor change to the mock timer with zero timeout in AsyncConsumerTest.

[lucasbru]

LGTM, thanks!

[kirktrue]

@philipnee—sorry I'm late to the party, but why do we submit the event to the queue when the timeout is 0?

[philipnee]

Hi @kirktrue - It was clearly documented why LegacyKafkaConsumer would do this, maybe it is because in some scenarios users want to update the position but actually don't care about the offset results. This is the snippet from the LegacyKafkaConsumer code:

          // if timeout is set to zero, do not try to poll the network client at all
            // and return empty immediately; otherwise try to get the results synchronously
            // and throw timeout exception if it cannot complete in time
            if (timer.timeoutMs() == 0L)
                return result;