org.apache.ibatis.cache.decorators

Class TransactionalCache

java.lang.Object

org.apache.ibatis.cache.decorators.TransactionalCache

All Implemented Interfaces:

Cache

public class TransactionalCache
extends Object
implements Cache

The 2nd level cache transactional buffer.

This class holds all cache entries that are to be added to the 2nd level cache during a Session. Entries are sent to the cache when commit is called or discarded if the Session is rolled back. Blocking cache support has been added. Therefore any get() that returns a cache miss will be followed by a put() so any lock associated with the key can be released.

Author:

Clinton Begin, Eduardo Macarron

Constructor Summary

Constructors

Constructor and Description
TransactionalCache(Cache delegate)

Method Summary

Modifier and Type	Method and Description
void	clear() Clears this cache instance.
void	commit()
String	getId()
Object	getObject(Object key)
int	getSize() Optional.
void	putObject(Object key, Object object)
Object	removeObject(Object key) As of 3.3.0 this method is only called during a rollback for any previous value that was missing in the cache.
void	rollback()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.ibatis.cache.Cache

getReadWriteLock

Constructor Detail

TransactionalCache

public TransactionalCache(Cache delegate)

Method Detail

getId

public String getId()

Specified by:

getId in interface Cache

Returns:

The identifier of this cache

getSize

public int getSize()

Description copied from interface: Cache

Optional. This method is not called by the core.

Specified by:

getSize in interface Cache

Returns:

The number of elements stored in the cache (not its capacity).

getObject

public Object getObject(Object key)

Specified by:

getObject in interface Cache

Parameters:

key - The key

Returns:

The object stored in the cache.

putObject

public void putObject(Object key,
                      Object object)

Specified by:

putObject in interface Cache

Parameters:

key - Can be any object but usually it is a CacheKey

object - The result of a select.

removeObject

public Object removeObject(Object key)

Description copied from interface: Cache

As of 3.3.0 this method is only called during a rollback for any previous value that was missing in the cache. This lets any blocking cache to release the lock that may have previously put on the key. A blocking cache puts a lock when a value is null and releases it when the value is back again. This way other threads will wait for the value to be available instead of hitting the database.

Specified by:

removeObject in interface Cache

Parameters:

key - The key

Returns:

Not used

clear

public void clear()

Description copied from interface: Cache

Clears this cache instance.

Specified by:

clear in interface Cache

commit

public void commit()

rollback

public void rollback()