/******************************************************************************* | |
* 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 org.eclipse.persistence.descriptors.ClassDescriptor; | |
import org.eclipse.persistence.internal.helper.DatabaseField; | |
import org.eclipse.persistence.internal.sessions.AbstractSession; | |
import org.eclipse.persistence.sessions.server.ClientSession; | |
/** | |
* PUBLIC: | |
* FieldPartitioningPolicy partitions access to a database cluster by a field value from the object, | |
* such as the object's id, location, or tenant. | |
* All write or read request for object's with that value are sent to the server. | |
* If a query does not include the field as a parameter, then it can either be sent | |
* to all server's and unioned, or left to the sesion's default behavior. | |
* @author James Sutherland | |
* @since EclipseLink 2.2 | |
*/ | |
public abstract class FieldPartitioningPolicy extends PartitioningPolicy { | |
/** The column to partition by. */ | |
protected DatabaseField partitionField; | |
/** If query does not have the partition field in it, should the query be sent to all databases. */ | |
protected boolean unionUnpartitionableQueries = false; | |
public FieldPartitioningPolicy() { | |
super(); | |
} | |
public FieldPartitioningPolicy(String partitionField) { | |
super(); | |
this.partitionField = new DatabaseField(partitionField); | |
} | |
public FieldPartitioningPolicy(String partitionField, boolean unionUnpartitionableQueries) { | |
this(partitionField); | |
this.unionUnpartitionableQueries = unionUnpartitionableQueries; | |
} | |
/** | |
* PUBLIC: | |
* Return the database column or query parameter to partition queries by. | |
* This is the table column name, not the class attribute name. | |
* The column value must be included in the query and should normally be part of the object's Id. | |
* This can also be the name of a query parameter. | |
* If a query does not contain the field the query will not be partitioned. | |
*/ | |
public DatabaseField getPartitionField() { | |
return partitionField; | |
} | |
/** | |
* PUBLIC: | |
* Set the database column or query parameter to partition queries by. | |
* This is the table column name, not the class attribute name. | |
* The column value must be included in the query and should normally be part of the object's Id. | |
* This can also be the name of a query parameter. | |
* If a query does not contain the field the query will not be partitioned. | |
*/ | |
public void setPartitionField(DatabaseField partitionField) { | |
this.partitionField = partitionField; | |
} | |
/** | |
* PUBLIC: | |
* Return the database column or query parameter to partition queries by. | |
* This is the table column name, not the class attribute name. | |
* The column value must be included in the query and should normally be part of the object's Id. | |
* This can also be the name of a query parameter. | |
* If a query does not contain the field the query will not be partitioned. | |
*/ | |
public String getPartitionFieldName() { | |
return getPartitionField().getName(); | |
} | |
/** | |
* PUBLIC: | |
* Set the database column or query parameter to partition queries by. | |
* This is the table column name, not the class attribute name. | |
* The column value must be included in the query and should normally be part of the object's Id. | |
* This can also be the name of a query parameter. | |
* If a query does not contain the field the query will not be partitioned. | |
*/ | |
public void setPartitionField(String partitionField) { | |
this.partitionField = new DatabaseField(partitionField); | |
} | |
/** | |
* PUBLIC: | |
* Return if queries that do not contain the partition field should be sent | |
* to every database and have the result unioned. | |
*/ | |
public boolean getUnionUnpartitionableQueries() { | |
return unionUnpartitionableQueries; | |
} | |
/** | |
* PUBLIC: | |
* Set if queries that do not contain the partition field should be sent | |
* to every database and have the result unioned. | |
*/ | |
public void setUnionUnpartitionableQueries(boolean unionUnpartitionableQueries) { | |
this.unionUnpartitionableQueries = unionUnpartitionableQueries; | |
} | |
/** | |
* INTERNAL: | |
* If persist should be partitioned, extra value from object. | |
*/ | |
protected Object extractPartitionValueForPersist(AbstractSession session, Object object, ClassDescriptor descriptor) { | |
if (!session.isClientSession()) { | |
return null; | |
} | |
ClientSession client = (ClientSession)session; | |
// Only assign the connection if exclusive. | |
if (!client.isExclusiveIsolatedClientSession() || client.hasWriteConnection()) { | |
return null; | |
} | |
return descriptor.getObjectBuilder().extractValueFromObjectForField(object, this.partitionField, session); | |
} | |
} |