Samrat002 commented on code in PR #6: URL: https://github.com/apache/flink-connector-redis-streams/pull/6#discussion_r3178535739
########## flink-connector-redis-streams/src/main/java/org/apache/flink/connector/redis/streams/source/reader/RedisStreamsSourceReader.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.flink.connector.redis.streams.source.reader; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.api.connector.source.SourceReaderContext; +import org.apache.flink.configuration.Configuration; +import org.apache.flink.connector.base.source.reader.SingleThreadMultiplexSourceReaderBase; +import org.apache.flink.connector.base.source.reader.fetcher.SingleThreadFetcherManager; +import org.apache.flink.connector.redis.streams.source.RedisStreamsDeserializationSchema; +import org.apache.flink.connector.redis.streams.source.reader.split.RedisStreamsSplitReader; +import org.apache.flink.connector.redis.streams.source.split.RedisStreamsSourceSplit; +import org.apache.flink.connector.redis.streams.source.split.RedisStreamsSourceSplitState; +import org.apache.flink.util.Preconditions; + +import io.lettuce.core.StreamMessage; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.List; +import java.util.Map; +import java.util.concurrent.atomic.AtomicReference; + +/** Source reader for Redis Streams. */ +@Internal +public class RedisStreamsSourceReader<T> + extends SingleThreadMultiplexSourceReaderBase< + StreamMessage<String, String>, + T, + RedisStreamsSourceSplit, + RedisStreamsSourceSplitState> { + + private static final Logger LOG = LoggerFactory.getLogger(RedisStreamsSourceReader.class); + + private final AtomicReference<RedisStreamsSplitReader> splitReaderRef; + + public RedisStreamsSourceReader( + SingleThreadFetcherManager<StreamMessage<String, String>, RedisStreamsSourceSplit> + splitFetcherManager, + RedisStreamsDeserializationSchema<T> deserializationSchema, + AtomicReference<RedisStreamsSplitReader> splitReaderRef, + Configuration config, + SourceReaderContext context) { + super( + splitFetcherManager, + new RedisStreamsRecordEmitter<>(deserializationSchema), + config, + context); + this.splitReaderRef = Preconditions.checkNotNull(splitReaderRef); + + LOG.info( + "RedisStreamsSourceReader initialized for subtask {}", context.getIndexOfSubtask()); + } + + @Override + protected void onSplitFinished(Map<String, RedisStreamsSourceSplitState> finishedSplitIds) { + LOG.info("Splits finished: {}", finishedSplitIds.keySet()); + } + + @Override + protected RedisStreamsSourceSplitState initializedState(RedisStreamsSourceSplit split) { + return new RedisStreamsSourceSplitState(split); + } + + @Override + protected RedisStreamsSourceSplit toSplitType( + String splitId, RedisStreamsSourceSplitState splitState) { + return splitState.toSplit(); Review Comment: Yes, this is there. The Kafka pattern, with SplitState extending Split and returning this, avoids the allocation entirely. In practice, `snapshotState()` is called at the checkpoint frequency (default: 10 s intervals), and the number of splits is bounded by the number of configured stream keys. The allocation cost is negligible. Adopting the inheritance would mean RedisStreamsSourceSplitState extends RedisStreamsSourceSplit, which changes the class hierarchy and is a non-trivial refactor. I'd rather keep the two classes cleanly separated for now and revisit if profiling shows this as a real cost. Let me know if it can be followed up on after the core implementation. -- 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]
