org.hibernate.cache.jbc2.collection
Class TransactionalAccess

java.lang.Object
  extended by 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


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