/*
* Copyright Terracotta, Inc.
*
* Licensed 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.ehcache.event;
import org.ehcache.Cache;
/**
* An event resulting from a mutative {@link Cache} operation.
*
* @param <K> the key type of the source cache
* @param <V> the value type of the source cache
*/
public interface CacheEvent<K, V> {
/**
* Gets the {@link EventType} of this event.
*
* @return the {@code EventType}
*/
EventType getType();
/**
* The key of the mapping affected by this event.
*
* @return the key of the mutated mapping
*/
K getKey();
/**
* The mapped value immediately after the mutative event occurred.
* <p>
* If the mutative event removes the mapping then {@code null} is returned.
*
* @return the mapped value after the mutation
*/
V getNewValue();
/**
* The mapped value immediately before the mutative event occurred.
* <p>
* If the mutative event created the mapping then {@code null} is returned.
*
* @return the mapped value before the mutation
*/
V getOldValue();
/**
* The source cache for this event
* <p>
* Calling back into the cache to perform operations is not supported. It is only provided as a way to identify the
* event source.
*
* @return the source cache
*/
@Deprecated
Cache<K, V> getSource();
}