/*
* 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.geode.cache.query;
/**
* Behavior of a user-defined aggregator. Aggregates values and returns a result. In addition to the
* methods in the interface, implementing classes must have a 0-arg public constructor.
*
*
*/
public interface Aggregator {
/**
* Accumulate the next scalar value
*
* @param value
*/
public void accumulate(Object value);
/**
* Initialize the Aggregator
*/
public void init();
/**
*
* @return Return the result scalar value
*/
public Object terminate();
}