org.apache.openjpa.datacache.CacheDistributionPolicy Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
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*/
package org.apache.openjpa.datacache;
import org.apache.openjpa.kernel.OpenJPAStateManager;
import org.apache.openjpa.lib.conf.Configurable;
/**
* A policy determines whether a given entity should be cached and if true, in which named partition of the
* cache.
*
* This policy is activated for each instance if and only if the cache settings specified in metadata
* such as JPA specification defined {@link Cacheable @Cacheable} annotation or OpenJPA specific
* {@link org.apache.openjpa.persistence.DataCache @DataCache} annotation or configuration property
* such as javax.persistence.sharedCache.mode determined the type of the instance being cachable.
*
* For example, a specific policy will never be active for when javax.persistence.sharedCache.mode
* is set to NONE.
*
* Distribution Policies are configurable. So a specific policy can be configured as
*
* <property name="openjpa.CacheDistributionPolicy" value="com.acme.FooPolicy(param1='xyz',param2=true)"/>
*
* where com.acme.FooPolicy is an implementation of this interface and defines bean style setter and
* getter methods for String property param1 and boolean property param2.
*
* @author Pinaki Poddar
*
* @since 2.0.0
*
*/
public interface CacheDistributionPolicy extends Configurable {
/**
* Selects the name of the cache where the given managed proxy object state be cached.
*
* @param sm the managed proxy object to be cached. The actual managed instance can be accessed from the proxy
* instance simply as sm.getManagedInstance().
*
* @param context the context of invocation. No specific semantics is attributed currently. Can be null.
*
* @return name of the cache or null, implying that that the instance should not be cached.
*/
String selectCache(OpenJPAStateManager sm, Object context);
}