Samrat002 commented on code in PR #6: URL: https://github.com/apache/flink-connector-redis-streams/pull/6#discussion_r3055287776
########## flink-connector-redis-streams/src/main/java/org/apache/flink/connector/redis/streams/source/split/RedisStreamsSourceSplit.java: ########## @@ -0,0 +1,101 @@ +/* + * 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.flink.connector.redis.streams.source.split; + +import org.apache.flink.annotation.PublicEvolving; +import org.apache.flink.api.connector.source.SourceSplit; + +import java.io.Serializable; +import java.util.Objects; + +/** + * A split representing a Redis Stream key. + * + * <p>Each split corresponds to one Redis Stream key and tracks the last read entry ID for + * checkpointing purposes. + */ +@PublicEvolving +public class RedisStreamsSourceSplit implements SourceSplit, Serializable { + + private static final long serialVersionUID = 1L; + + private final String streamKey; + private final String lastReadEntryId; Review Comment: Added @Nullable annotation on the field and getter. > The constructor Javadoc says "null if starting fresh" — so null is a valid documented value. But getLastReadEntryId() has no https://github.com/nullable on its return type. Now, a better approach could be to replace null with the Redis sentinel "0-0". Redis accepts "0-0" in XREADGROUP as "before all entries" — it is the natural "start from beginning" ID. This eliminates the nullability entirely. This conflates two semantically distinct states. null means "no position yet — this is a fresh split." "0-0" is a valid Redis entry ID, meaning "before all entries." On recovery, the split reader uses XReadArgs.StreamOffset.lastConsumed(), which delegates position tracking to the Redis consumer group server-side, not to this field. Making this field non-null would imply it's used for positioning, which could be misleading. I think keeping null for "fresh start" is clearer. Do you see any future issues that it can lead to? -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
