/******************************************************************************* | |
* Copyright (c) 2011, 2013 Oracle and/or its affiliates. All rights reserved. | |
* This program and the accompanying materials are made available under the | |
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 | |
* which accompanies this distribution. | |
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html | |
* and the Eclipse Distribution License is available at | |
* http://www.eclipse.org/org/documents/edl-v10.php. | |
* | |
* Contributors: | |
* James Sutherland (Oracle) - initial API and implementation | |
******************************************************************************/ | |
package org.eclipse.persistence.descriptors.partitioning; | |
import java.util.ArrayList; | |
import java.util.List; | |
import org.eclipse.persistence.internal.databaseaccess.Accessor; | |
import org.eclipse.persistence.internal.sessions.AbstractRecord; | |
import org.eclipse.persistence.internal.sessions.AbstractSession; | |
import org.eclipse.persistence.queries.DatabaseQuery; | |
/** | |
* PUBLIC: | |
* UnionPartitionPolicy sends queries to all connection pools and unions the results. | |
* This is for queries or relationships that span partitions when partitioning is used, | |
* such as on a ManyToMany cross partition relationship. | |
* @author James Sutherland | |
* @since EclipseLink 2.2 | |
*/ | |
public class UnionPartitioningPolicy extends ReplicationPartitioningPolicy { | |
protected boolean replicateWrites = false; | |
public UnionPartitioningPolicy() { | |
super(); | |
} | |
public UnionPartitioningPolicy(boolean replicateWrites) { | |
super(); | |
this.replicateWrites = replicateWrites; | |
} | |
public UnionPartitioningPolicy(String... pools) { | |
super(pools); | |
} | |
public UnionPartitioningPolicy(List<String> pools) { | |
super(pools); | |
} | |
/** | |
* PUBLIC: | |
* Return if write queries should be replicated. | |
* Writes are normally not replicated when unioning, | |
* but can be for ManyToMany relationships, when the join table needs to be replicated. | |
*/ | |
public boolean getReplicateWrites() { | |
return replicateWrites; | |
} | |
/** | |
* PUBLIC: | |
* Set if write queries should be replicated. | |
* Writes are normally not replicated when unioning, | |
* but can be for ManyToMany relationships, when the join table needs to be replicated. | |
*/ | |
public void setReplicateWrites(boolean replicateWrites) { | |
this.replicateWrites = replicateWrites; | |
} | |
/** | |
* INTERNAL: | |
* Get a connection from one of the pools in a round robin rotation fashion. | |
*/ | |
public List<Accessor> getConnectionsForQuery(AbstractSession session, DatabaseQuery query, AbstractRecord arguments) { | |
if (!this.replicateWrites && query.isModifyQuery()) { | |
return null; | |
} | |
List<Accessor> accessors = new ArrayList<Accessor>(this.connectionPools.size()); | |
for (String poolName : this.connectionPools) { | |
accessors.add(getAccessor(poolName, session, query, false)); | |
} | |
return accessors; | |
} | |
} |