curcur commented on a change in pull request #11725: URL: https://github.com/apache/flink/pull/11725#discussion_r425559040
########## File path: flink-connectors/flink-connector-kafka/src/main/java/org/apache/flink/streaming/connectors/kafka/internal/KafkaShuffleFetcher.java ########## @@ -0,0 +1,380 @@ +/* + * 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.streaming.connectors.kafka.internal; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.annotation.VisibleForTesting; +import org.apache.flink.api.common.typeutils.TypeSerializer; +import org.apache.flink.api.common.typeutils.base.IntSerializer; +import org.apache.flink.api.common.typeutils.base.LongSerializer; +import org.apache.flink.core.memory.DataInputDeserializer; +import org.apache.flink.metrics.MetricGroup; +import org.apache.flink.streaming.api.functions.AssignerWithPeriodicWatermarks; +import org.apache.flink.streaming.api.functions.AssignerWithPunctuatedWatermarks; +import org.apache.flink.streaming.api.functions.source.SourceFunction; +import org.apache.flink.streaming.api.watermark.Watermark; +import org.apache.flink.streaming.connectors.kafka.internals.AbstractFetcher; +import org.apache.flink.streaming.connectors.kafka.internals.KafkaCommitCallback; +import org.apache.flink.streaming.connectors.kafka.internals.KafkaTopicPartition; +import org.apache.flink.streaming.connectors.kafka.internals.KafkaTopicPartitionState; +import org.apache.flink.streaming.runtime.tasks.ProcessingTimeService; +import org.apache.flink.util.Preconditions; +import org.apache.flink.util.SerializedValue; + +import org.apache.kafka.clients.consumer.ConsumerRecord; +import org.apache.kafka.clients.consumer.ConsumerRecords; +import org.apache.kafka.clients.consumer.OffsetAndMetadata; +import org.apache.kafka.common.TopicPartition; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import javax.annotation.Nonnull; + +import java.io.Serializable; +import java.util.Comparator; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.Properties; + +import static org.apache.flink.streaming.connectors.kafka.shuffle.FlinkKafkaShuffleProducer.KafkaSerializer.TAG_REC_WITHOUT_TIMESTAMP; +import static org.apache.flink.streaming.connectors.kafka.shuffle.FlinkKafkaShuffleProducer.KafkaSerializer.TAG_REC_WITH_TIMESTAMP; +import static org.apache.flink.streaming.connectors.kafka.shuffle.FlinkKafkaShuffleProducer.KafkaSerializer.TAG_WATERMARK; +import static org.apache.flink.util.Preconditions.checkState; + +/** + * Fetch data from Kafka for Kafka Shuffle. + */ +@Internal +public class KafkaShuffleFetcher<T> extends AbstractFetcher<T, TopicPartition> { Review comment: That's a good question. It is because what I really override is fetcher's method (how fetcher fetch records, deserialize records and emit watermarks). That's why I have to subclass Fetcher anyway. I tried different ways, there is one way to avoid duplicated code, but needs to add a default constructor in one of consumer or fetcher base classes. I think it is unsafe to do it, and that's why it is ended up like this. ---------------------------------------------------------------- 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
