mjsax commented on a change in pull request #10462: URL: https://github.com/apache/kafka/pull/10462#discussion_r616266276
########## File path: streams/src/main/java/org/apache/kafka/streams/state/internals/LeftOrRightValue.java ########## @@ -0,0 +1,113 @@ +/* + * 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.state.internals; + +import java.util.Objects; + +/** + * This class is used in combination of {@link KeyAndJoinSide}. The {@link KeyAndJoinSide} class + * combines a key with a boolean value that specifies if the key is found in the left side of a + * join or on the right side. This {@link LeftOrRightValue} object contains either the V1 value, + * which is found in the left topic, or V2 value if it is found in the right topic. + */ +public class LeftOrRightValue<V1, V2> { + private final V1 leftValue; + private final V2 rightValue; + + private LeftOrRightValue(final V1 leftValue, final V2 rightValue) { + if (leftValue != null && rightValue != null) { Review comment: We do filter both `null` keys and `null` values. For `null` keys, because we cannot really compute the join, and for `null` value because a `null` would be a delete in RocksDB and thus we cannot store `null` value to begin with. -- 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
