com.sun.appserv.util.cache

Class BoundedMultiLruCache

java.lang.Object

com.sun.appserv.util.cache.BaseCache

com.sun.appserv.util.cache.MultiLruCache

com.sun.appserv.util.cache.BoundedMultiLruCache

All Implemented Interfaces:

Cache

public class BoundedMultiLruCache
extends MultiLruCache

MultiLruCache -- in-memory bounded LRU cache with multiple LRU lists Underlying Hashtable is made into logical segments, with each segment having its own LRU list.

Nested Class Summary

Nested classes/interfaces inherited from class com.sun.appserv.util.cache.BaseCache

BaseCache.CacheItem

Field Summary

Fields

Modifier and Type	Field and Description
protected long	currentSize
protected long	maxSize

Fields inherited from class com.sun.appserv.util.cache.MultiLruCache

DEFAULT_HASHTABLE_SEGMENT_SIZE, listsLength, LRU_HEAD, LRU_TAIL

Fields inherited from class com.sun.appserv.util.cache.BaseCache

bucketLocks, buckets, entryCount, hitCount, listeners, maxBuckets, maxEntries, missCount, refreshFlags, removalCount, threshold

Constructor Summary

Constructors

Constructor and Description
BoundedMultiLruCache()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	decrementCurrentSize(int size)
Object	getStatByName(String key) get the desired statistic counter
Map	getStats() get the stats snapshot
protected void	incrementCurrentSize(int size) synchronized counter updates
void	init(int maxCapacity, Properties props) initialize the LRU cache
protected boolean	isThresholdReached() has cache reached its threshold
protected BaseCache.CacheItem	itemAdded(BaseCache.CacheItem item) this item is just added to the cache
protected void	itemRefreshed(BaseCache.CacheItem item, int oldSize) item value has been refreshed
protected void	itemRemoved(BaseCache.CacheItem item) item value has been removed from the cache

Methods inherited from class com.sun.appserv.util.cache.MultiLruCache

createItem, handleOverflow, incrementTrimIndex, itemAccessed, trimLru

Methods inherited from class com.sun.appserv.util.cache.BaseCache

_put, _remove, _removeItem, add, add, addCacheListener, clear, clearStats, contains, decrementEntryCount, destroy, elements, eq, get, get, getAll, getEntryCount, getIndex, getIndex, hash, incrementAddCount, incrementEntryCount, incrementHitCount, incrementMissCount, incrementOverflowCount, incrementRefreshCount, incrementRemovalCount, init, isEmpty, keys, loadValue, notifyRefresh, put, put, remove, remove, remove, removeAll, trimExpiredEntries, trimItem, values, waitRefresh

Methods inherited from class java.lang.Object

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

Field Detail

maxSize

protected long maxSize

currentSize

protected long currentSize

Constructor Detail

BoundedMultiLruCache

public BoundedMultiLruCache()

Method Detail

init

public void init(int maxCapacity,
        Properties props)
          throws Exception

initialize the LRU cache

Specified by:

init in interface Cache

Overrides:

init in class MultiLruCache

Parameters:

maxCapacity - maximum number of entries this cache may hold

props - opaque list of properties for a given cache implementation

Throws:

Exception

itemAdded

protected BaseCache.CacheItem itemAdded(BaseCache.CacheItem item)

this item is just added to the cache

Overrides:

itemAdded in class MultiLruCache

Parameters:

item - CacheItem that was created

Returns:

a overflow item; may be null Cache bucket is already synchronized by the caller

itemRefreshed

protected void itemRefreshed(BaseCache.CacheItem item,
                 int oldSize)

item value has been refreshed

Overrides:

itemRefreshed in class MultiLruCache

Parameters:

item - CacheItem that was refreshed

oldSize - size of the previous value that was refreshed Cache bucket is already synchronized by the caller

itemRemoved

protected void itemRemoved(BaseCache.CacheItem item)

item value has been removed from the cache

Overrides:

itemRemoved in class MultiLruCache

Parameters:

item - CacheItem that was just removed Cache bucket is already synchronized by the caller

isThresholdReached

protected boolean isThresholdReached()

has cache reached its threshold

Overrides:

isThresholdReached in class BaseCache

Returns:

true when the cache reached its threshold

incrementCurrentSize

protected final void incrementCurrentSize(int size)

synchronized counter updates

decrementCurrentSize

protected final void decrementCurrentSize(int size)

getStatByName

public Object getStatByName(String key)

get the desired statistic counter

Specified by:

getStatByName in interface Cache

Overrides:

getStatByName in class MultiLruCache

Parameters:

key - to corresponding stat

Returns:

an Object corresponding to the stat See also: Constant.java for the key

getStats

public Map getStats()

Description copied from class: MultiLruCache

get the stats snapshot

Specified by:

getStats in interface Cache

Overrides:

getStats in class MultiLruCache

Returns:

a Map of stats See also: Constant.java for the keys