org.h2.util
Class CacheLRU

java.lang.Object
  extended by org.h2.util.CacheLRU
All Implemented Interfaces:
Cache

public class CacheLRU
extends java.lang.Object
implements Cache

A cache implementation based on the last recently used (LRU) algorithm.


Method Summary
 void clear()
          Clear the cache.
 CacheObject find(int pos)
          Get an element from the cache if it is available.
 CacheObject get(int pos)
          Get an element in the cache if it is available.
 java.util.ArrayList<CacheObject> getAllChanged()
          Get all objects in the cache that have been changed.
static Cache getCache(CacheWriter writer, java.lang.String cacheType, int cacheSize)
          Create a cache of the given type and size.
 int getMaxMemory()
          Get the maximum memory to be used.
 int getMemory()
          Get the used size in KB.
 void put(CacheObject rec)
          Add an element to the cache.
 void remove(int pos)
          Remove an object from the cache.
 void setMaxMemory(int maxKb)
          Set the maximum memory to be used by this cache.
 CacheObject update(int pos, CacheObject rec)
          Update an element in the cache.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

getCache

public static Cache getCache(CacheWriter writer,
                             java.lang.String cacheType,
                             int cacheSize)
Create a cache of the given type and size.

Parameters:
writer - the cache writer
cacheType - the cache type
cacheSize - the size
Returns:
the cache object

clear

public void clear()
Description copied from interface: Cache
Clear the cache.

Specified by:
clear in interface Cache

put

public void put(CacheObject rec)
Description copied from interface: Cache
Add an element to the cache. Other items may fall out of the cache because of this. It is not allowed to add the same record twice.

Specified by:
put in interface Cache
Parameters:
rec - the object

update

public CacheObject update(int pos,
                          CacheObject rec)
Description copied from interface: Cache
Update an element in the cache. This will move the item to the front of the list.

Specified by:
update in interface Cache
Parameters:
pos - the unique key of the element
rec - the element
Returns:
the element

remove

public void remove(int pos)
Description copied from interface: Cache
Remove an object from the cache.

Specified by:
remove in interface Cache
Parameters:
pos - the unique key of the element

find

public CacheObject find(int pos)
Description copied from interface: Cache
Get an element from the cache if it is available. This will not move the item to the front of the list.

Specified by:
find in interface Cache
Parameters:
pos - the unique key of the element
Returns:
the element or null

get

public CacheObject get(int pos)
Description copied from interface: Cache
Get an element in the cache if it is available. This will move the item to the front of the list.

Specified by:
get in interface Cache
Parameters:
pos - the unique key of the element
Returns:
the element or null

getAllChanged

public java.util.ArrayList<CacheObject> getAllChanged()
Description copied from interface: Cache
Get all objects in the cache that have been changed.

Specified by:
getAllChanged in interface Cache
Returns:
the list of objects

setMaxMemory

public void setMaxMemory(int maxKb)
Description copied from interface: Cache
Set the maximum memory to be used by this cache.

Specified by:
setMaxMemory in interface Cache
Parameters:
maxKb - the maximum size in KB

getMaxMemory

public int getMaxMemory()
Description copied from interface: Cache
Get the maximum memory to be used.

Specified by:
getMaxMemory in interface Cache
Returns:
the maximum size in KB

getMemory

public int getMemory()
Description copied from interface: Cache
Get the used size in KB.

Specified by:
getMemory in interface Cache
Returns:
the current size in KB