org.hibernate.cache.jbc2.collection
Class ReadOnlyAccess

java.lang.Object
  org.hibernate.cache.jbc2.collection.TransactionalAccess
      org.hibernate.cache.jbc2.collection.ReadOnlyAccess

All Implemented Interfaces:

CollectionRegionAccessStrategy

public class ReadOnlyAccess
extends TransactionalAccess

This defines the strategy for transactional access to collection data in a pessimistic-locking JBossCache using its 2.x APIs.

The read-only access to a JBossCache really is still transactional, just with the extra semantic or guarantee that we will not update data.

Author:

Steve Ebersole

Constructor Summary

ReadOnlyAccess(CollectionRegionImpl region)
Create a provider of read-only access to the specific region.

Method Summary

SoftLock	lockItem(Object key, Object version) We are going to attempt to update/delete the keyed object. This method is used by "asynchronous" concurrency strategies. 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.
SoftLock	lockRegion() Lock the entire region
void	unlockItem(Object key, SoftLock lock) 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.
void	unlockRegion(SoftLock lock) Called after we have finished the attempted invalidation of the entire region

Methods inherited from class org.hibernate.cache.jbc2.collection.TransactionalAccess

evict, evictAll, get, getRegion, putFromLoad, putFromLoad, remove, removeAll

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReadOnlyAccess

public ReadOnlyAccess(CollectionRegionImpl region)

Create a provider of read-only access to the specific region.

Parameters:

region - The region to which this provides access.

Method Detail

lockItem

public SoftLock lockItem(Object key,
                         Object version)
                  throws CacheException

We are going to attempt to update/delete the keyed object. This method is used by "asynchronous" concurrency strategies.

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.

Specified by:

lockItem in interface CollectionRegionAccessStrategy

Overrides:

lockItem in class TransactionalAccess

Parameters:

key - The key of the item to lock

version - The item's current version value

Returns:

A representation of our lock on the item; or null.

Throws:

CacheException - Propogated from underlying Region

lockRegion

public SoftLock lockRegion()
                    throws CacheException

Lock the entire region

Specified by:

lockRegion in interface CollectionRegionAccessStrategy

Overrides:

lockRegion in class TransactionalAccess

Returns:

A representation of our lock on the item; or null.

Throws:

CacheException - Propogated from underlying Region

unlockItem

public void unlockItem(Object key,
                       SoftLock lock)
                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.

Specified by:

unlockItem in interface CollectionRegionAccessStrategy

Overrides:

unlockItem in class TransactionalAccess

Parameters:

key - The item key

lock - The lock previously obtained from CollectionRegionAccessStrategy.lockItem(java.lang.Object, java.lang.Object)

Throws:

CacheException - Propogated from underlying Region

unlockRegion

public void unlockRegion(SoftLock lock)
                  throws CacheException

Called after we have finished the attempted invalidation of the entire region

Specified by:

unlockRegion in interface CollectionRegionAccessStrategy

Overrides:

unlockRegion in class TransactionalAccess

Parameters:

lock - The lock previously obtained from CollectionRegionAccessStrategy.lockRegion()

Throws:

CacheException - Propogated from underlying Region