org.apache.flink.streaming.api.functions.windowing.delta.DeltaFunction 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.functions.windowing.delta;
import org.apache.flink.annotation.PublicEvolving;
import java.io.Serializable;
/**
* This interface allows the implementation of a function which calculates the
* delta between two data points. Delta functions might be used in delta
* policies and allow flexible adaptive windowing based on the arriving data
* points.
*
* @param
* The type of input data which can be compared using this function.
*/
@PublicEvolving
public interface DeltaFunction extends Serializable {
/**
* Calculates the delta between two given data points.
*
* @param oldDataPoint
* the old data point.
* @param newDataPoint
* the new data point.
* @return the delta between the two given points.
*/
double getDelta(DATA oldDataPoint, DATA newDataPoint);
}