KIP-363 Make FunctionConversions deprecated

[joan38]

As pointed out in this comment #5539 (comment) the object FunctionConversions is only of internal use and therefore should be private to the lib only so that we can do changes without going through KIP like this one.

KIP: https://cwiki.apache.org/confluence/display/KAFKA/KIP-363%3A+Make+FunctionConversions+private

@guozhangwang @vvcephei @mjsax @debasishg and whoever wants to join the party 😄

[joan38]

We are waiting for the min of 72h of the KIP vote to finish:
http://mail-archives.apache.org/mod_mbox/kafka-dev/201808.mbox/%3CCAJYfrs3GOrFrY9K3wToyg+Pj-AXtc=RZvvCWTH9fmWVjsEYs_w@mail.gmail.com%3E

Which means we can merge this after 26 Aug 2018 18:24:56 GMT

Can we label this streams @mjsax ?

Thanks

[debasishg]

👍

[joan38]

@guozhangwang This is all good to merge

[mjsax]

@joan38 I just replied to the KIP thread -- also note, that the vote did not pass yet and the KIP is not accepted yet. It's required to have 3 binding votes (so far only Guozhang gave binding +1).

Also, can you update this PR accordingly? Thanks a lot.

[joan38]

12:40:15 * What went wrong:
12:40:15 Execution failed for task ':streams:streams-scala:spotbugsMain'.
12:40:15 > SpotBugs rule violations were found. See the report at: file:///home/jenkins/jenkins-slave/workspace/kafka-pr-jdk10-scala2.12/streams/streams-scala/build/reports/spotbugs/main.xml

Do you know what this means?

[guozhangwang]

@joan38 spotbugs was added recently, you can run ./gradlew spotbugsMain spotbugsTest -x test (stated in README.md) locally to see the results.

[joan38]

Thanks @guozhangwang
I get:

Bug type EQ_UNUSUAL (click for details) In class org.apache.kafka.streams.scala.FunctionsCompatConversions$AggregatorFromFunctionIn method org.apache.kafka.streams.scala.FunctionsCompatConversions$AggregatorFromFunction.equals(Object)At FunctionsCompatConversions.scala:[line 88]
--

EQ_UNUSUAL: Unusual equals method
This class doesn't do any of the patterns we recognize for checking that the type of the argument is compatible with the type of the this object. There might not be anything wrong with this code, but it is worth reviewing.

Is it possible to disable this since it's a copy and past from the other class?

[vvcephei]

@joan38 . Hmm. I'm not sure why it's running for that one class. Perhaps the other class is already excluded, and this one doesn't match the pattern?

The exclusions are here: gradle/spotbugs-exclude.xml

[joan38]

@vvcephei you are right, it is excluded.
I will add this one also to the exclusion.

Other than that are we happy with the change?

[vvcephei]

Hey @joan38, yep, assuming the tests are passing, this LGTM. Thanks!

[guozhangwang]

spotbug still fails in jenkins:

04:43:17 Execution failed for task ':streams:streams-scala:spotbugsMain'.

[joan38]

It's now ready to merge

[guozhangwang]

LGTM!