org.apache.flink.streaming.api.operators.OnWatermarkCallback Maven / Gradle / Ivy
/*
* 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.api.operators;
import org.apache.flink.annotation.Internal;
import org.apache.flink.streaming.api.watermark.Watermark;
import java.io.IOException;
/**
* A callback registered with the {@link InternalWatermarkCallbackService} service. This callback
* will be invoked for all keys registered with the service, upon reception of a watermark.
*/
@Internal
public interface OnWatermarkCallback {
/**
* The action to be triggered upon reception of a watermark.
*
* @param key The current key.
* @param watermark The current watermark.
*/
void onWatermark(KEY key, Watermark watermark) throws IOException;
}