| /* |
| * 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.table.runtime; |
| |
| import org.apache.flink.streaming.api.functions.AssignerWithPeriodicWatermarks; |
| import org.apache.flink.streaming.api.operators.AbstractStreamOperator; |
| import org.apache.flink.streaming.api.operators.ChainingStrategy; |
| import org.apache.flink.streaming.api.operators.OneInputStreamOperator; |
| import org.apache.flink.streaming.api.watermark.Watermark; |
| import org.apache.flink.streaming.runtime.streamrecord.StreamRecord; |
| import org.apache.flink.streaming.runtime.tasks.ProcessingTimeCallback; |
| import org.apache.flink.table.dataformat.BaseRow; |
| |
| /** |
| * A stream operator that extracts timestamps from stream elements and |
| * generates periodic watermarks. |
| */ |
| public class WatermarkAssignerOperator |
| extends AbstractStreamOperator<BaseRow> |
| implements OneInputStreamOperator<BaseRow, BaseRow>, ProcessingTimeCallback { |
| |
| private static final long serialVersionUID = 1L; |
| |
| private final int rowtimeIndex; |
| |
| private final long offset; |
| |
| private transient long watermarkInterval; |
| |
| private transient long currentWatermark; |
| |
| private transient long currentMaxTimestamp; |
| |
| public WatermarkAssignerOperator(int rowtimeIndex, long offset) { |
| this.rowtimeIndex = rowtimeIndex; |
| this.offset = offset; |
| this.chainingStrategy = ChainingStrategy.ALWAYS; |
| } |
| |
| @Override |
| public void open() throws Exception { |
| super.open(); |
| |
| // watermark and timestamp should start from 0 |
| currentWatermark = 0; |
| currentMaxTimestamp = 0; |
| watermarkInterval = getExecutionConfig().getAutoWatermarkInterval(); |
| |
| if (watermarkInterval > 0) { |
| long now = getProcessingTimeService().getCurrentProcessingTime(); |
| getProcessingTimeService().registerTimer(now + watermarkInterval, this); |
| } |
| } |
| |
| @Override |
| public void processElement(StreamRecord<BaseRow> element) throws Exception { |
| BaseRow row = element.getValue(); |
| if (row.isNullAt(rowtimeIndex)) { |
| throw new RuntimeException("RowTime field should not be null," + |
| " please convert it to a non-null long value."); |
| } |
| long ts = row.getLong(rowtimeIndex); |
| currentMaxTimestamp = Math.max(currentMaxTimestamp, ts); |
| // forward element |
| output.collect(element); |
| |
| // eagerly emit watermark to avoid period timer not called |
| // current_ts - last_ts > interval |
| if (currentMaxTimestamp - (currentWatermark + offset) > watermarkInterval) { |
| advanceWatermark(); |
| } |
| } |
| |
| private void advanceWatermark() { |
| long newWatermark = currentMaxTimestamp - offset; |
| if (newWatermark > currentWatermark) { |
| currentWatermark = newWatermark; |
| // emit watermark |
| output.emitWatermark(new Watermark(newWatermark)); |
| } |
| } |
| |
| @Override |
| public void onProcessingTime(long timestamp) throws Exception { |
| advanceWatermark(); |
| |
| // register next timer |
| long now = getProcessingTimeService().getCurrentProcessingTime(); |
| getProcessingTimeService().registerTimer(now + watermarkInterval, this); |
| } |
| |
| /** |
| * Override the base implementation to completely ignore watermarks propagated from |
| * upstream (we rely only on the {@link AssignerWithPeriodicWatermarks} to emit |
| * watermarks from here). |
| */ |
| @Override |
| public void processWatermark(Watermark mark) throws Exception { |
| // if we receive a Long.MAX_VALUE watermark we forward it since it is used |
| // to signal the end of input and to not block watermark progress downstream |
| if (mark.getTimestamp() == Long.MAX_VALUE && currentWatermark != Long.MAX_VALUE) { |
| currentWatermark = Long.MAX_VALUE; |
| output.emitWatermark(mark); |
| } |
| } |
| |
| @Override |
| public void endInput() throws Exception { |
| processWatermark(Watermark.MAX_WATERMARK); |
| } |
| |
| @Override |
| public void close() throws Exception { |
| super.close(); |
| |
| // emit a final watermark |
| advanceWatermark(); |
| } |
| } |