com.hazelcast.map.EntryProcessor Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2013, 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;
/**
* An EntryProcessor passes you a {@link java.util.Map.Entry}. At the time you receive it
* the entry is locked and not released until the EntryProcessor completes.
* This obviates the need to explicitly lock as would be required with a {@link java.util.concurrent.ExecutorService}.
*
* Performance can be very high as the data is not moved off the Member partition. This avoids network cost and, if
* the storage format is {@link com.hazelcast.config.InMemoryFormat#OBJECT} then there is no deserialization or serialization
* cost.
*
* EntryProcessors execute on the partition thread in a member. Multiple operations on the same partition are queued.
*
* While executing partition migrations are not allowed. Any migrations are queued on the partition thread.
*
* An EntryProcessor may not be re-entrant i.e. it may not access the same {@link Map}. Limitation: you can only access
* data on the same partition.
*
* @param
* @param
*/
public interface EntryProcessor extends Serializable {
/**
* Process the entry without worrying about concurrency.
*
*
* @param entry entry to be processes
* @return result of the process
*/
Object process(Map.Entry entry);
/**
* Get the entry processor to be applied to backup entries.
*
*
* @return back up processor
*/
EntryBackupProcessor getBackupProcessor();
}