vvcephei commented on a change in pull request #8927: URL: https://github.com/apache/kafka/pull/8927#discussion_r446473287
########## File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/ProcessorContextUtils.java ########## @@ -0,0 +1,39 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.kafka.streams.processor.internals; + +import org.apache.kafka.streams.processor.ProcessorContext; +import org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl; + +public final class ProcessorContextUtils { Review comment: Uh, no, that was an oversight :) I might as well fix it in this PR, so I'll not merge just now. Thanks for pointing it out. I think where it leaves us, in a nutshell, is that state stores should never cast the context, not as long as their `init()` method is a public interface. This class is a way to collect all the casting-related sins and put them all in one place where we can keep an eye on them. Casting doesn't always indicate a design failure, but in this case, it 100% does. I'd hope that everything in this class gets designed away and we can delete the class. I'd flip the table and do it right now, but I don't want to block the unit-testability of the PAPI behind a bunch of KIPs. I'll make tickets to fix the stuff that needs to be fixed. In contrast, note that all the Processor implementations that power our DSL are very much _not_ for public use, so for them, casting to InternalProcessorContext is fair game. Although, I _have_ found and/or fixed a fair number of bugs following from casting in the processors as well. So, although, it's not a contract violation, it still may not be a good idea. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
