com.solarmetric.kodo.util
Class CacheMap

java.lang.Object
  |
  +--com.solarmetric.kodo.util.CacheMap

All Implemented Interfaces:

Map

public class CacheMap

extends Object

implements Map

A map that keeps hard references to a fixed number of elements and moves expired references to a soft reference map. Additionally, objects that are pinned are not counted towards the max size of the map.

Inner classes inherited from class java.util.Map

Map.Entry

Constructor Summary

CacheMap()
Create a new CacheMap with an initial maximum unpinned object size of 1000.

CacheMap(int size)
Create a new CacheMap with an initial maximum unpinned object size of size.

CacheMap(int size, float load)
Create a new CacheMap with an initial maximum unpinned object size of size and a load factor of load.

Method Summary

void	clear() Removes pinned objects as well as unpinned ones.
boolean	containsKey(Object o)
boolean	containsValue(Object o)
Set	entrySet()
protected void	flush() Remove unpinned items from the end of the LRU cache until the LRU cache size is less than or equal to the maximum.
Object	get(Object key)
int	getCacheSize() Returns the maximum number of unpinned objects to keep hard references to.
Set	getPinnedKeys() Returns the keys to the objects currently pinned into memory.
boolean	isEmpty()
Set	keySet()
boolean	pin(Object key) Locks the key-value pair identified by key into the map.
Object	put(Object key, Object value)
void	putAll(Map map)
Object	remove(Object key) If key is pinned into the cache, the pin is cleared and the object is removed.
void	setCacheSize(int size) Sets the maximum number of unpinned objects to keep hard references to.
int	size()
boolean	unpin(Object key) Removes the key-value pair identified by key from the set of pinned objects.
Collection	values()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

CacheMap

public CacheMap()

Create a new CacheMap with an initial maximum unpinned object size of 1000.

CacheMap

public CacheMap(int size)

Create a new CacheMap with an initial maximum unpinned object size of size.

CacheMap

public CacheMap(int size,
                float load)

Create a new CacheMap with an initial maximum unpinned object size of size and a load factor of load.

Method Detail

setCacheSize

public void setCacheSize(int size)

Sets the maximum number of unpinned objects to keep hard references to. If the map contains more unpinned objects than size, then this method will result in the cache flushing old values.

getCacheSize

public int getCacheSize()

Returns the maximum number of unpinned objects to keep hard references to.

getPinnedKeys

public Set getPinnedKeys()

Returns the keys to the objects currently pinned into memory.

pin

public boolean pin(Object key)

Locks the key-value pair identified by key into the map. Objects pinned into the map are not counted towards the maximum size of the map, and are never removed except by explicit calls to remove(java.lang.Object) or clear().

If a key that is not currently in the cache is pinned, it will not be considered pinned once that key is used in the cache.

Returns:

true if key's value was pinned into the cache; false if the key is not in the cache.

unpin

public boolean unpin(Object key)

Removes the key-value pair identified by key from the set of pinned objects. This key becomes a candidate for removal from the LRU map if the map exceeds the maximum size.

Returns:

true if key's value was unpinned from the cache; false if the key is not in the cache.

flush

protected void flush()

Remove unpinned items from the end of the LRU cache until the LRU cache size is less than or equal to the maximum.

get

public Object get(Object key)

Specified by:

get in interface Map

put

public Object put(Object key,
                  Object value)

Specified by:

put in interface Map

putAll

public void putAll(Map map)

Specified by:

putAll in interface Map

remove

public Object remove(Object key)

If key is pinned into the cache, the pin is cleared and the object is removed.

Specified by:

remove in interface Map

clear

public void clear()

Removes pinned objects as well as unpinned ones.

Specified by:

clear in interface Map

size

public int size()

Specified by:

size in interface Map

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map

containsKey

public boolean containsKey(Object o)

Specified by:

containsKey in interface Map

containsValue

public boolean containsValue(Object o)

Specified by:

containsValue in interface Map

keySet

public Set keySet()

Specified by:

keySet in interface Map

values

public Collection values()

Specified by:

values in interface Map

entrySet

public Set entrySet()

Specified by:

entrySet in interface Map