ableegoldman commented on a change in pull request #9609: URL: https://github.com/apache/kafka/pull/9609#discussion_r534424621
########## File path: streams/src/main/java/org/apache/kafka/streams/kstream/internals/graph/SourceGraphNode.java ########## @@ -0,0 +1,71 @@ +/* + * 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.kstream.internals.graph; + +import java.util.Collection; +import java.util.HashSet; +import java.util.Set; +import java.util.regex.Pattern; +import org.apache.kafka.common.serialization.Serde; +import org.apache.kafka.streams.kstream.internals.ConsumedInternal; + +abstract public class SourceGraphNode<K, V> extends StreamsGraphNode { + + private Collection<String> topicNames; + private Pattern topicPattern; + private final ConsumedInternal<K, V> consumedInternal; + + public SourceGraphNode(final String nodeName, + final Collection<String> topicNames, + final ConsumedInternal<K, V> consumedInternal) { + super(nodeName); + + this.topicNames = topicNames; + this.consumedInternal = consumedInternal; + } + + public SourceGraphNode(final String nodeName, + final Pattern topicPattern, + final ConsumedInternal<K, V> consumedInternal) { + + super(nodeName); + + this.topicPattern = topicPattern; + this.consumedInternal = consumedInternal; + } + + public Set<String> topicNames() { + return new HashSet<>(topicNames); Review comment: > All other dependent calls create a singleton collection which can be easily replaced with a singleton set Ah ok, I didn't notice that. I guess I only looked at `StreamsBuilder#stream` > Actually, I do not understand why StreamsBuilder#stream() takes a collection instead of a set. This I totally agree with. I suspect the intention was just for convenience, so users don't have to do a list->set conversion themselves, but I personally don't find that to be a very strong argument. It doesn't seem worth doing a KIP over, but maybe if we rewrite some large parts of the DSL in the future, we can fix this as well By "callers" I meant the method body of `StreamsBuilder#stream`, which doesn't really care whether there are duplicates in the collection because it's only job is to pass the topics straight from the user to this source node. But I see your point. If I touch on some related code in a future PR I can fix this on the side, or I'd be happy to review a PR if you want to submit one ---------------------------------------------------------------- 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
