/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*
*/
package org.hibernate.cache.access;
import org.hibernate.cache.EntityRegion;
import org.hibernate.cache.CacheException;
/**
* Contract for managing transactional and concurrent access to cached entity
* data. The expected call sequences related to various operations are:<ul>
* <li><b>INSERTS</b> : {@link #insert} -> {@link #afterInsert}</li>
* <li><b>UPDATES</b> : {@link #lockItem} -> {@link #update} -> {@link #afterUpdate}</li>
* <li><b>DELETES</b> : {@link #lockItem} -> {@link #remove} -> {@link #unlockItem}</li>
* </ul>
* <p/>
* There is another usage pattern that is used to invalidate entries
* after performing "bulk" HQL/SQL operations:
* {@link #lockRegion} -> {@link #removeAll} -> {@link #unlockRegion}
*
* @author Gavin King
* @author Steve Ebersole
*/
public interface EntityRegionAccessStrategy {
/**
* Get the wrapped entity cache region
*
* @return The underlying region
*/
public EntityRegion getRegion();
/**
* Attempt to retrieve an object from the cache. Mainly used in attempting
* to resolve entities/collections from the second level cache.
*
* @param key The key of the item to be retrieved.
* @param txTimestamp a timestamp prior to the transaction start time
* @return the cached object or <tt>null</tt>
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public Object get(Object key, long txTimestamp) throws CacheException;
/**
* Attempt to cache an object, after loading from the database.
*
* @param key The item key
* @param value The item
* @param txTimestamp a timestamp prior to the transaction start time
* @param version the item version number
* @return <tt>true</tt> if the object was successfully cached
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public boolean putFromLoad(
Object key,
Object value,
long txTimestamp,
Object version) throws CacheException;
/**
* Attempt to cache an object, after loading from the database, explicitly
* specifying the minimalPut behavior.
*
* @param key The item key
* @param value The item
* @param txTimestamp a timestamp prior to the transaction start time
* @param version the item version number
* @param minimalPutOverride Explicit minimalPut flag
* @return <tt>true</tt> if the object was successfully cached
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public boolean putFromLoad(
Object key,
Object value,
long txTimestamp,
Object version,
boolean minimalPutOverride) throws CacheException;
/**
* We are going to attempt to update/delete the keyed object. This
* method is used by "asynchronous" concurrency strategies.
* <p/>
* The returned object must be passed back to release(), to release the
* lock. Concurrency strategies which do not support client-visible
* locks may silently return null.
*
* @param key The key of the item to lock
* @param version The item's current version value
* @return A representation of our lock on the item; or null.
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public SoftLock lockItem(Object key, Object version) throws CacheException;
/**
* Lock the entire region
*
* @return A representation of our lock on the item; or null.
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public SoftLock lockRegion() throws CacheException;
/**
* Called when we have finished the attempted update/delete (which may or
* may not have been successful), after transaction completion. This method
* is used by "asynchronous" concurrency strategies.
*
* @param key The item key
* @param lock The lock previously obtained from {@link #lockItem}
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public void unlockItem(Object key, SoftLock lock) throws CacheException;
/**
* Called after we have finished the attempted invalidation of the entire
* region
*
* @param lock The lock previously obtained from {@link #lockRegion}
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public void unlockRegion(SoftLock lock) throws CacheException;
/**
* Called after an item has been inserted (before the transaction completes),
* instead of calling evict().
* This method is used by "synchronous" concurrency strategies.
*
* @param key The item key
* @param value The item
* @param version The item's version value
* @return Were the contents of the cache actual changed by this operation?
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public boolean insert(Object key, Object value, Object version) throws CacheException;
/**
* Called after an item has been inserted (after the transaction completes),
* instead of calling release().
* This method is used by "asynchronous" concurrency strategies.
*
* @param key The item key
* @param value The item
* @param version The item's version value
* @return Were the contents of the cache actual changed by this operation?
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public boolean afterInsert(Object key, Object value, Object version) throws CacheException;
/**
* Called after an item has been updated (before the transaction completes),
* instead of calling evict(). This method is used by "synchronous" concurrency
* strategies.
*
* @param key The item key
* @param value The item
* @param currentVersion The item's current version value
* @param previousVersion The item's previous version value
* @return Were the contents of the cache actual changed by this operation?
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public boolean update(Object key, Object value, Object currentVersion, Object previousVersion) throws CacheException;
/**
* Called after an item has been updated (after the transaction completes),
* instead of calling release(). This method is used by "asynchronous"
* concurrency strategies.
*
* @param key The item key
* @param value The item
* @param currentVersion The item's current version value
* @param previousVersion The item's previous version value
* @param lock The lock previously obtained from {@link #lockItem}
* @return Were the contents of the cache actual changed by this operation?
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public boolean afterUpdate(Object key, Object value, Object currentVersion, Object previousVersion, SoftLock lock) throws CacheException;
/**
* Called after an item has become stale (before the transaction completes).
* This method is used by "synchronous" concurrency strategies.
*
* @param key The key of the item to remove
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public void remove(Object key) throws CacheException;
/**
* Called to evict data from the entire region
*
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public void removeAll() throws CacheException;
/**
* Forcibly evict an item from the cache immediately without regard for transaction
* isolation.
*
* @param key The key of the item to remove
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public void evict(Object key) throws CacheException;
/**
* Forcibly evict all items from the cache immediately without regard for transaction
* isolation.
*
* @throws CacheException Propogated from underlying {@link org.hibernate.cache.Region}
*/
public void evictAll() throws CacheException;
}