org.hibernate.cache.jbc2.collection
Class TransactionalAccess

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

All Implemented Interfaces:

CollectionRegionAccessStrategy

Direct Known Subclasses:

OptimisticTransactionalAccess, ReadOnlyAccess

public class TransactionalAccess
extends Object
implements CollectionRegionAccessStrategy

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

Author:

Steve Ebersole, Brian Stansberry

Constructor Summary

	TransactionalAccess(CollectionRegionImpl region) Create a new TransactionalAccess.
protected	TransactionalAccess(CollectionRegionImpl region, TransactionalAccessDelegate delegate) Allow subclasses to define the delegate.

Method Summary

void	evict(Object key) Forcibly evict an item from the cache immediately without regard for transaction isolation.
void	evictAll() Forcibly evict all items from the cache immediately without regard for transaction isolation.
Object	get(Object key, long txTimestamp) Attempt to retrieve an object from the cache.
CollectionRegion	getRegion() Get the wrapped collection cache region
SoftLock	lockItem(Object key, Object version) We are going to attempt to update/delete the keyed object.
SoftLock	lockRegion() Lock the entire region
boolean	putFromLoad(Object key, Object value, long txTimestamp, Object version) Attempt to cache an object, after loading from the database.
boolean	putFromLoad(Object key, Object value, long txTimestamp, Object version, boolean minimalPutOverride) Attempt to cache an object, after loading from the database, explicitly specifying the minimalPut behavior.
void	remove(Object key) Called after an item has become stale (before the transaction completes).
void	removeAll() Called to evict data from 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.
void	unlockRegion(SoftLock lock) Called after we have finished the attempted invalidation of the entire region

Methods inherited from class java.lang.Object

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

Constructor Detail

TransactionalAccess

public TransactionalAccess(CollectionRegionImpl region)

Create a new TransactionalAccess.

Parameters:

region - the region to which this provides access

TransactionalAccess

protected TransactionalAccess(CollectionRegionImpl region,
                              TransactionalAccessDelegate delegate)

Allow subclasses to define the delegate.

Parameters:

region - the region to which this provides access

delegate - type of transactional access

Method Detail

getRegion

public CollectionRegion getRegion()

Get the wrapped collection cache region

Specified by:

getRegion in interface CollectionRegionAccessStrategy

Returns:

The underlying region

get

public Object get(Object key,
                  long txTimestamp)
           throws CacheException

Attempt to retrieve an object from the cache. Mainly used in attempting to resolve entities/collections from the second level cache.

Specified by:

get in interface CollectionRegionAccessStrategy

Parameters:

key - The key of the item to be retrieved.

txTimestamp - a timestamp prior to the transaction start time

Returns:

the cached object or null

Throws:

CacheException - Propogated from underlying Region

putFromLoad

public boolean putFromLoad(Object key,
                           Object value,
                           long txTimestamp,
                           Object version)
                    throws CacheException

Attempt to cache an object, after loading from the database.

Specified by:

putFromLoad in interface CollectionRegionAccessStrategy

Parameters:

key - The item key

value - The item

txTimestamp - a timestamp prior to the transaction start time

version - the item version number

Returns:

true if the object was successfully cached

Throws:

CacheException - Propogated from underlying Region

putFromLoad

public boolean putFromLoad(Object key,
                           Object value,
                           long txTimestamp,
                           Object version,
                           boolean minimalPutOverride)
                    throws CacheException

Attempt to cache an object, after loading from the database, explicitly specifying the minimalPut behavior.

Specified by:

putFromLoad in interface CollectionRegionAccessStrategy

Parameters:

key - The item key

value - The item

txTimestamp - a timestamp prior to the transaction start time

version - the item version number

minimalPutOverride - Explicit minimalPut flag

Returns:

true if the object was successfully cached

Throws:

CacheException - Propogated from underlying Region

remove

public void remove(Object key)
            throws CacheException

Called after an item has become stale (before the transaction completes). This method is used by "synchronous" concurrency strategies.

Specified by:

remove in interface CollectionRegionAccessStrategy

Parameters:

key - The key of the item to remove

Throws:

CacheException - Propogated from underlying Region

removeAll

public void removeAll()
               throws CacheException

Called to evict data from the entire region

Specified by:

removeAll in interface CollectionRegionAccessStrategy

Throws:

CacheException - Propogated from underlying Region

evict

public void evict(Object key)
           throws CacheException

Forcibly evict an item from the cache immediately without regard for transaction isolation.

Specified by:

evict in interface CollectionRegionAccessStrategy

Parameters:

key - The key of the item to remove

Throws:

CacheException - Propogated from underlying Region

evictAll

public void evictAll()
              throws CacheException

Forcibly evict all items from the cache immediately without regard for transaction isolation.

Specified by:

evictAll in interface CollectionRegionAccessStrategy

Throws:

CacheException - Propogated from underlying Region

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

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

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

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

Parameters:

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

Throws:

CacheException - Propogated from underlying Region