com.basecmp.core.persistence.impl
Class AssetCacheMgr

java.lang.Object
  AbstractHelper
      com.basecmp.core.persistence.impl.AssetCacheMgr

public class AssetCacheMgr

extends AbstractHelper

Object-cache for instances of PersistentAsset. AssetCacheMgr is implemented as a singleton and provides read-access to the cache via static method get(). The cache itself is backed by an LRU-Map (Apache Commons Collection) and is fully event-controlled. The private contructor is called via a "static contructor" and registers itself for the persistence-eventtypes ReadEvent, SaveEvent, DeleteEvent and BindingEvent. AssetCacheMgr is currently disabled by default. Caching can be enabled with the Config-Variable 'persistence.assethandling.enableCache' set 'true' in system-configfile. The cachesize is currently limited to 5000 instances. AssetCacheMgr is used by PersistentAssetFactory to provide transparent object-caching. Other classes may use the cache but this is not recommended.

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Serialized Form

Author:

Wolfgang Schröder

Field Summary

static int	CACHECONTROL_ADD
static int	CACHECONTROL_DROP
static int	CACHECONTROL_UPDATE
static int	DEFAULT_MAX_CACHE_SIZE

Method Summary

static boolean	contains(java.lang.Long cid)
protected static int	currentReferenceNavigationMapSize()
protected static int	currentReferenceNavigationSize()
static int	currentSize()
static void	flushAll()
static PersistentAsset	get(java.lang.Long cid) Delivers an instance of PersistentAsset from the Object-Cache or null, if the asset with the given cid is not present in the object-cache.
static int[]	getStats() Returns runtime-statistics of the cache-manager of the running measuring internval.
static boolean	isActive()
protected void	load() Empty implementation.
static int	maxSize()
void	processEvent(java.util.EventObject event) Processes the events sent by persistence-layer.

Methods inherited from class java.lang.Object

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

Field Detail

CACHECONTROL_ADD

public static final int CACHECONTROL_ADD

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Constant Field Values

CACHECONTROL_DROP

public static final int CACHECONTROL_DROP

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Constant Field Values

CACHECONTROL_UPDATE

public static final int CACHECONTROL_UPDATE

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Constant Field Values

DEFAULT_MAX_CACHE_SIZE

public static final int DEFAULT_MAX_CACHE_SIZE

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Constant Field Values

Method Detail

contains

public static boolean contains(java.lang.Long cid)

currentReferenceNavigationMapSize

protected static int currentReferenceNavigationMapSize()

currentReferenceNavigationSize

protected static int currentReferenceNavigationSize()

currentSize

public static int currentSize()

flushAll

public static void flushAll()

get

public static PersistentAsset get(java.lang.Long cid)

Delivers an instance of PersistentAsset from the Object-Cache or null, if the asset with the given cid is not present in the object-cache.

getStats

public static int[] getStats()

Returns runtime-statistics of the cache-manager of the running measuring internval. Order of values is:

• Index 0: Time in millis since last measuring interval began
• Index 1: Current size of LRU-Cache (independent from measuring time)
• Index 2: Maximum size of LRU-Cache (configured value, independent from measuring time)
• Index 3: Hits of requested asset from cache
• Index 4: Misses of requested asset from cache
• Index 5: New entries
• Index 6: Dropped entries

Returns:

isActive

public static boolean isActive()

load

protected void load()

Empty implementation.

maxSize

public static int maxSize()

processEvent

public void processEvent(java.util.EventObject event)

Processes the events sent by persistence-layer.