org.apache.openjpa.slice.ReplicationPolicy Maven / Gradle / Ivy
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* distributed with this work for additional information
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* to you 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,
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.openjpa.slice;
import java.util.List;
/**
* Policy to select one or more of the physical databases referred as
* slice in which a given persistent instance will be persisted.
*
* This interface is invoked for entity types that are specified as ReplicatedTypes in the configuration.
*
* @author Pinaki Poddar
*
* @see DistributionPolicy
*
*/
public interface ReplicationPolicy {
/**
* Gets the name of the slices where a given instance will be replicated.
*
* @param pc The newly persistent or to-be-merged object.
* @param slices list of names of the active slices. The ordering of
* the list is either explicit openjpa.slice.Names property
* or implicit i.e. alphabetic order of available identifiers if
* openjpa.slice.Names is unspecified.
* @param context generic persistence context managing the given instance.
*
* @return identifier of the slices. This names must match one of the
* given slice names.
*
* @see DistributedConfiguration#getActiveSliceNames()
*/
String[] replicate(Object pc, List slices, Object context);
/**
* Implements a default replication policy to replicate the given
* instance across all available slices.
*
*/
public static class Default implements ReplicationPolicy {
public String[] replicate(Object pc, List slices,
Object context) {
return slices.toArray(new String[slices.size()]);
}
}
}