com.hazelcast.hibernate.access

Class ReadOnlyAccessDelegate<T extends HazelcastRegion>

java.lang.Object

com.hazelcast.hibernate.access.AbstractAccessDelegate<T>

com.hazelcast.hibernate.access.NonStrictReadWriteAccessDelegate<T>

com.hazelcast.hibernate.access.ReadOnlyAccessDelegate<T>

Type Parameters:

T - implementation type of HazelcastRegion

All Implemented Interfaces:

AccessDelegate<T>

public class ReadOnlyAccessDelegate<T extends HazelcastRegion>
extends NonStrictReadWriteAccessDelegate<T>

Guarantees that view is read-only and no updates can be made

Author:

Leo Kim (lkim@limewire.com)

Field Summary

Fields inherited from class com.hazelcast.hibernate.access.AbstractAccessDelegate

cache, hazelcastRegion, log, versionComparator

Constructor Summary

Constructors

Constructor and Description
ReadOnlyAccessDelegate(T hazelcastRegion, Properties props)

Method Summary

Modifier and Type	Method and Description
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, org.hibernate.cache.access.SoftLock lock) Called after an item has been updated (after the transaction completes), instead of calling release().
boolean	insert(Object key, Object value, Object version) Called after an item has been inserted (before the transaction completes), instead of calling evict().
org.hibernate.cache.access.SoftLock	lockItem(Object key, Object version) We are going to attempt to update/delete the keyed object.
org.hibernate.cache.access.SoftLock	lockRegion() NO-OP
void	removeAll() Called to evict data from the entire region
void	unlockItem(Object key, org.hibernate.cache.access.SoftLock lock) Called when we have finished the attempted update/delete (which may or may not have been successful), after transaction completion.
void	unlockRegion(org.hibernate.cache.access.SoftLock lock) This will issue a log warning stating that an attempt was made to unlock a read-only cache 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().

Methods inherited from class com.hazelcast.hibernate.access.NonStrictReadWriteAccessDelegate

remove

Methods inherited from class com.hazelcast.hibernate.access.AbstractAccessDelegate

evict, evictAll, get, getHazelcastRegion, putFromLoad, putFromLoad

Methods inherited from class java.lang.Object

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

Constructor Detail

ReadOnlyAccessDelegate

public ReadOnlyAccessDelegate(T hazelcastRegion,
                              Properties props)

Method Detail

afterInsert

public boolean afterInsert(Object key,
                           Object value,
                           Object version)
                    throws org.hibernate.cache.CacheException

Description copied from class: NonStrictReadWriteAccessDelegate

Called after an item has been inserted (after the transaction completes), instead of calling release(). This method is used by "asynchronous" concurrency strategies.

Returns false since this is a non-strict read/write cache access strategy

Specified by:

afterInsert in interface AccessDelegate<T extends HazelcastRegion>

Overrides:

afterInsert in class NonStrictReadWriteAccessDelegate<T extends HazelcastRegion>

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:

org.hibernate.cache.CacheException - Propagated from underlying Region

afterUpdate

public boolean afterUpdate(Object key,
                           Object value,
                           Object currentVersion,
                           Object previousVersion,
                           org.hibernate.cache.access.SoftLock lock)
                    throws org.hibernate.cache.CacheException

Description copied from interface: AccessDelegate

Called after an item has been updated (after the transaction completes), instead of calling release(). This method is used by "asynchronous" concurrency strategies.

Specified by:

afterUpdate in interface AccessDelegate<T extends HazelcastRegion>

Overrides:

afterUpdate in class NonStrictReadWriteAccessDelegate<T extends HazelcastRegion>

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 AccessDelegate.lockItem(java.lang.Object, java.lang.Object)

Returns:

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

Throws:

UnsupportedOperationException - Always thrown as we cannot update an item in a read-only cache

org.hibernate.cache.CacheException - Propagated from underlying Region

insert

public boolean insert(Object key,
                      Object value,
                      Object version)
               throws org.hibernate.cache.CacheException

Called after an item has been inserted (before the transaction completes), instead of calling evict(). This method is used by "synchronous" concurrency strategies.

Returns false since this is an asynchronous cache access strategy.

This cache is asynchronous hence a no-op

Specified by:

insert in interface AccessDelegate<T extends HazelcastRegion>

Overrides:

insert in class NonStrictReadWriteAccessDelegate<T extends HazelcastRegion>

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:

org.hibernate.cache.CacheException - Propagated from underlying Region

lockItem

public org.hibernate.cache.access.SoftLock lockItem(Object key,
                                                    Object version)
                                             throws org.hibernate.cache.CacheException

Description copied from interface: AccessDelegate

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 AccessDelegate<T extends HazelcastRegion>

Overrides:

lockItem in class NonStrictReadWriteAccessDelegate<T extends HazelcastRegion>

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:

org.hibernate.cache.CacheException - Propagated from underlying Region

lockRegion

public org.hibernate.cache.access.SoftLock lockRegion()
                                               throws org.hibernate.cache.CacheException

Description copied from class: AbstractAccessDelegate

NO-OP

Specified by:

lockRegion in interface AccessDelegate<T extends HazelcastRegion>

Overrides:

lockRegion in class AbstractAccessDelegate<T extends HazelcastRegion>

Returns:

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

Throws:

UnsupportedOperationException - Thrown always because a read-only cache region cannot be locked

org.hibernate.cache.CacheException - Propagated from underlying Region

removeAll

public void removeAll()
               throws org.hibernate.cache.CacheException

Description copied from interface: AccessDelegate

Called to evict data from the entire region

Specified by:

removeAll in interface AccessDelegate<T extends HazelcastRegion>

Overrides:

removeAll in class NonStrictReadWriteAccessDelegate<T extends HazelcastRegion>

Throws:

org.hibernate.cache.CacheException - Propagated from underlying Region

unlockItem

public void unlockItem(Object key,
                       org.hibernate.cache.access.SoftLock lock)
                throws org.hibernate.cache.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.

Should be a no-op since this cache is read-only

Specified by:

unlockItem in interface AccessDelegate<T extends HazelcastRegion>

Overrides:

unlockItem in class NonStrictReadWriteAccessDelegate<T extends HazelcastRegion>

Parameters:

key - The item key

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

Throws:

org.hibernate.cache.CacheException - Propagated from underlying Region

unlockRegion

public void unlockRegion(org.hibernate.cache.access.SoftLock lock)
                  throws org.hibernate.cache.CacheException

This will issue a log warning stating that an attempt was made to unlock a read-only cache region.

Specified by:

unlockRegion in interface AccessDelegate<T extends HazelcastRegion>

Overrides:

unlockRegion in class AbstractAccessDelegate<T extends HazelcastRegion>

Parameters:

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

Throws:

org.hibernate.cache.CacheException - Propagated from underlying Region

update

public boolean update(Object key,
                      Object value,
                      Object currentVersion,
                      Object previousVersion)
               throws org.hibernate.cache.CacheException

Description copied from class: NonStrictReadWriteAccessDelegate

Called after an item has been updated (before the transaction completes), instead of calling evict(). This method is used by "synchronous" concurrency strategies.

Removes the entry since this is a non-strict read/write cache strategy.

Specified by:

update in interface AccessDelegate<T extends HazelcastRegion>

Overrides:

update in class NonStrictReadWriteAccessDelegate<T extends HazelcastRegion>

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:

UnsupportedOperationException - Thrown always because update is not possible on a read-only cache

org.hibernate.cache.CacheException - Propagated from underlying Region