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/*
* Copyright (c) 2010-2015 Pivotal Software, 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. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.cache;
/**
* Implementers of interface PartitionResolver enable custom
* partitioning on the PartitionedRegion.
*
* 1. The Key class can implement PartitionResolver interface to
* enable custom partitioning OR
* 2. Configure your own PartitionResolver class in partition attributes (For
* instance when the Key is a primitive type or String) Implement the
* appropriate equals - For all implementations, you need to be sure to code the
* class equals method so it properly verifies equality for the
* PartitionResolver implementation. This might mean verifying that class names
* are the same or that the returned routing objects are the same etc.. When you
* initiate the partitioned region on multiple nodes, GemFire uses the equals
* method to ensure you are using the same PartitionResolver implementation for
* all of the nodes for the region.
*
*
* GemFire uses the routing object's hashCode to determine where the data is
* being managed. Say, for example, you want to colocate all Trades by month and
* year.The key is implemented by TradeKey class which also implements the
* PartitionResolver interface.
*
* public class TradeKey implements PartitionResolver {
* private String tradeID;
* private Month month ;
* private Year year ;
*
* public TradingKey(){ }
* public TradingKey(Month month, Year year){
* this.month = month;
* this.year = year;
* }
* public Object getRoutingObject(EntryOperation opDetails){
* return this.month + this.year;
* }
}
*
* In the example above, all trade entries with the same month and year are
* guaranteed to be colocated.
*
*
* @author Yogesh Mahajan
* @author Mitch Thomas
*
* @since 6.0
*/
public interface PartitionResolver extends CacheCallback {
/**
* @param opDetails
* the detail of the entry operation e.g.
* {@link Region#get(Object)}
* @throws RuntimeException
* any exception thrown will terminate the operation and the
* exception will be passed to the calling thread.
* @return object associated with entry operation which allows the Partitioned
* Region to store associated data together
*/
public Object getRoutingObject(EntryOperation opDetails);
/**
* Returns the name of the PartitionResolver
*
* @return String name
*/
public String getName();
}