pvary commented on code in PR #8553: URL: https://github.com/apache/iceberg/pull/8553#discussion_r1339700464
########## flink/v1.17/flink/src/main/java/org/apache/iceberg/flink/source/reader/WatermarkExtractorRecordEmitter.java: ########## @@ -0,0 +1,64 @@ +/* + * 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.iceberg.flink.source.reader; + +import org.apache.flink.api.common.eventtime.Watermark; +import org.apache.flink.api.connector.source.SourceOutput; +import org.apache.iceberg.flink.source.split.IcebergSourceSplit; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Emitter which emits the watermarks, records and updates the split position. + * + * <p>The Emitter emits watermarks at the beginning of every split provided by the {@link + * IcebergWatermarkExtractor}. + */ +class WatermarkExtractorRecordEmitter<T> implements SerializableRecordEmitter<T> { + private static final Logger LOG = LoggerFactory.getLogger(WatermarkExtractorRecordEmitter.class); + private final IcebergWatermarkExtractor timeExtractor; + private String lastSplit = null; + private long watermark; + + WatermarkExtractorRecordEmitter(IcebergWatermarkExtractor timeExtractor) { + this.timeExtractor = timeExtractor; + } + + @Override + public void emitRecord( + RecordAndPosition<T> element, SourceOutput<T> output, IcebergSourceSplit split) { + if (!split.splitId().equals(lastSplit)) { + long newWatermark = timeExtractor.extractWatermark(split); + if (newWatermark < watermark) { + LOG.warn( + "Watermark decreased. PreviousWM {}, currentWM {}, previousSplit {}, currentSplit {}.", + watermark, + newWatermark, + lastSplit, + split.splitId()); + } + watermark = newWatermark; + output.emitWatermark(new Watermark(watermark)); + lastSplit = split.splitId(); + } + + output.collect(element.record()); + split.updatePosition(element.fileOffset(), element.recordOffset()); + } Review Comment: Ohh.. I misunderstood @sundargates's comment. I thought the suggestion was to squash the `WatermarkExtractorRecordEmitter` and the original emitter. That would cost performance wise. Inheritance would not cause issue in this case, but having inheritance to reuse 2 lines is IMHO would be an overkill here. Just makes it harder to read the code. If/when the common code becomes longer, we might want to do that, but until then I think it is better this way. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
