guozhangwang commented on code in PR #12663: URL: https://github.com/apache/kafka/pull/12663#discussion_r975715686
########## clients/src/main/java/org/apache/kafka/clients/consumer/internals/EventHandler.java: ########## @@ -0,0 +1,29 @@ +/* + * 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.clients.consumer.internals; + +/** + * The EventHandler interfaces the client and handler implementation. The client should add an event for consumption, + * and try to poll for the responses. Here, one could poll a response with type K, and add a request with type T. + * @param <T> Event request type + * @param <K> Event response type + */ +public interface EventHandler<T, K> { + public K poll(); + public boolean add(T event); Review Comment: From our offline discussions, I think there are two channels of communicating "responses" back: 1) the caller send a request, along with a future, and then either sync or async waiting on the future, in this case it does not expect "polling" the response; 2) the caller does not have a target response to wait in mind, and would just want to poll for any responses that may become available and react on them. For commitSync, for example, since the caller only cares about a specific response, it may be not appropriate to try polling responses since there will be a lot of other responses getting polled but the caller does not care, hence it would likely falling into the first case above. Could we add some javadocs clarifying which scenarios will leverage on each of the two? -- 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. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
