org.hibernate.cache.access
Interface EntityRegionAccessStrategy

All Known Implementing Classes:

EntityAccessStrategyAdapter, OptimisticReadOnlyAccess, OptimisticTransactionalAccess, ReadOnlyAccess, TransactionalAccess

public interface EntityRegionAccessStrategy

Contract for managing transactional and concurrent access to cached entity data. The expected call sequences related to various operations are:

• INSERTS : insert(java.lang.Object, java.lang.Object, java.lang.Object) -> afterInsert(java.lang.Object, java.lang.Object, java.lang.Object)
• UPDATES : lockItem(java.lang.Object, java.lang.Object) -> update(java.lang.Object, java.lang.Object, java.lang.Object, java.lang.Object) -> afterUpdate(java.lang.Object, java.lang.Object, java.lang.Object, java.lang.Object, org.hibernate.cache.access.SoftLock)
• DELETES : lockItem(java.lang.Object, java.lang.Object) -> remove(java.lang.Object) -> unlockItem(java.lang.Object, org.hibernate.cache.access.SoftLock)

There is another usage pattern that is used to invalidate entries after performing "bulk" HQL/SQL operations: lockRegion() -> removeAll() -> unlockRegion(org.hibernate.cache.access.SoftLock)

Author:

Gavin King, Steve Ebersole

Method Summary

boolean	afterInsert(Object key, Object value, Object version) Called after an item has been inserted (after the transaction completes), instead of calling release().
boolean	afterUpdate(Object key, Object value, Object currentVersion, Object previousVersion, SoftLock lock) Called after an item has been updated (after the transaction completes), instead of calling release().
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.
EntityRegion	getRegion() Get the wrapped entity cache region
boolean	insert(Object key, Object value, Object version) Called after an item has been inserted (before the transaction completes), instead of calling evict().
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
boolean	update(Object key, Object value, Object currentVersion, Object previousVersion) Called after an item has been updated (before the transaction completes), instead of calling evict().

Method Detail

getRegion

EntityRegion getRegion()

Get the wrapped entity cache region

Returns:

The underlying region

get

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.

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

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

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

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

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.

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

lockItem

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.

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

SoftLock lockRegion()
                    throws CacheException

Lock the entire region

Returns:

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

Throws:

CacheException - Propogated from underlying Region

unlockItem

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.

Parameters:

key - The item key

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

Throws:

CacheException - Propogated from underlying Region

unlockRegion

void unlockRegion(SoftLock lock)
                  throws CacheException

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

Parameters:

lock - The lock previously obtained from lockRegion()

Throws:

CacheException - Propogated from underlying Region

insert

boolean insert(Object key,
               Object value,
               Object version)
               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.

Parameters:

key - The item key

value - The item

version - The item's version value

Returns:

Were the contents of the cache actual changed by this operation?

Throws:

CacheException - Propogated from underlying Region

afterInsert

boolean afterInsert(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.

Parameters:

key - The item key

value - The item

version - The item's version value

Returns:

Were the contents of the cache actual changed by this operation?

Throws:

CacheException - Propogated from underlying Region

update

boolean update(Object key,
               Object value,
               Object currentVersion,
               Object previousVersion)
               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.

Parameters:

key - The item key

value - The item

currentVersion - The item's current version value

previousVersion - The item's previous version value

Returns:

Were the contents of the cache actual changed by this operation?

Throws:

CacheException - Propogated from underlying Region

afterUpdate

boolean afterUpdate(Object key,
                    Object value,
                    Object currentVersion,
                    Object previousVersion,
                    SoftLock lock)
                    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.

Parameters:

key - The item key

value - The item

currentVersion - The item's current version value

previousVersion - The item's previous version value

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

Returns:

Were the contents of the cache actual changed by this operation?

Throws:

CacheException - Propogated from underlying Region

remove

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.

Parameters:

key - The key of the item to remove

Throws:

CacheException - Propogated from underlying Region

removeAll

void removeAll()
               throws CacheException

Called to evict data from the entire region

Throws:

CacheException - Propogated from underlying Region

evict

void evict(Object key)
           throws CacheException

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

Parameters:

key - The key of the item to remove

Throws:

CacheException - Propogated from underlying Region

evictAll

void evictAll()
              throws CacheException

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

Throws:

CacheException - Propogated from underlying Region