com.hazelcast.map.EntryBackupProcessor Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2016, Hazelcast, Inc. All Rights Reserved.
*
* 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 com.hazelcast.map;
import java.io.Serializable;
import java.util.Map;
/**
* Processes an entry on a backup partition.
*
* Note that there is a possibility which an {@link com.hazelcast.map.EntryProcessor} can see
* that a key exists but its backup processor {@link com.hazelcast.map.EntryBackupProcessor} may not find it
* at run time due to an unsent backup of a previous operation (e.g. a previous put). In those situations,
* Hazelcast internally/eventually will sync those owner and backup partitions so you will not lose any data.
* When coding an {@link com.hazelcast.map.EntryBackupProcessor}, you should take that case into account, otherwise
* {@link java.lang.NullPointerException}s can be seen since {@link java.util.Map.Entry#getValue()} may return null.
*
* @param Type of key of a {@link java.util.Map.Entry}
* @param Type of value of a {@link java.util.Map.Entry}
* @see com.hazelcast.map.EntryProcessor
* @see com.hazelcast.map.AbstractEntryProcessor
*/
public interface EntryBackupProcessor extends Serializable {
void processBackup(Map.Entry entry);
}