org.apache.ibatis.cache.decorators

Class WeakCache

java.lang.Object

org.apache.ibatis.cache.decorators.WeakCache

All Implemented Interfaces:

Cache

public class WeakCache
extends Object
implements Cache

Weak Reference cache decorator. Thanks to Dr. Heinz Kabutz for his guidance here.

Author:

Clinton Begin

Constructor Summary

Constructors

Constructor and Description
WeakCache(Cache delegate)

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Clears this cache instance
String	getId()
Object	getObject(Object key)
ReadWriteLock	getReadWriteLock() Optional.
int	getSize() Optional.
void	putObject(Object key, Object value)
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	setSize(int size)

Methods inherited from class java.lang.Object

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

Constructor Detail

WeakCache

public WeakCache(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).

setSize

public void setSize(int size)

putObject

public void putObject(Object key,
             Object value)

Specified by:

putObject in interface Cache

Parameters:

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

value - The result of a select.

getObject

public Object getObject(Object key)

Specified by:

getObject in interface Cache

Parameters:

key - The key

Returns:

The object stored in the cache.

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

getReadWriteLock

public ReadWriteLock getReadWriteLock()

Description copied from interface: Cache

Optional. As of 3.2.6 this method is no longer called by the core. Any locking needed by the cache must be provided internally by the cache provider.

Specified by:

getReadWriteLock in interface Cache

Returns:

A ReadWriteLock