ERXExpiringCache< K, V > Class Reference

Collaboration diagram for ERXExpiringCache< K, V >:

List of all members.

Classes

class Entry< V >

class GrimReaper

Public Member Functions

synchronized NSArray< K > allKeys ()

ERXExpiringCache (long expiryTimeInSeconds, long cleanupPauseInSeconds)

ERXExpiringCache (long expiryTimeInSeconds)

ERXExpiringCache ()

synchronized boolean isStale (K key)

synchronized boolean isStaleWithVersion (K key, Object currentVersionKey)

synchronized V objectForKey (K key)

synchronized V objectForKeyWithVersion (K key, Object currentVersionKey)

synchronized void removeAllObjects ()

synchronized V removeObjectForKey (K key)

synchronized void removeStaleEntries ()

synchronized void setObjectForKey (V object, K key)

synchronized void setObjectForKeyWithVersion (V object, K key, Object currentVersionKey)

synchronized void setObjectForKeyWithVersion (V object, K key, Object currentVersionKey, long expirationTime)

void startBackgroundExpiration ()

synchronized void stopBackgroundExpiration ()

String toString ()

Static Public Attributes

static final long NO_TIMEOUT = 0L

static final Object NO_VERSION = new Object()

Protected Member Functions

synchronized Entry< V > entryForKey (K key)

synchronized void removeEntryForKey (Entry< V > entry, K key)

synchronized void setEntryForKey (Entry< V > entry, K key)

Static Protected Member Functions

static synchronized
ERXExpiringCache.GrimReaper reaper ()

Private Member Functions

long expiryTime ()

Private Attributes

NSMutableDictionary< K,
ERXExpiringCache.Entry< V > > _backingDictionary

long _cleanupPause

long _expiryTime

long _lastCleanupTime

Static Private Attributes

static ERXExpiringCache.GrimReaper _reaper

Detailed Description

Cache that expires its entries based on time or version changes. Version can be any object that represents the current state of a cached value. When retrieving the value, you can retrieve it with a version key. If the version key used in the retrieval does not match the original version key of the object in the cache, then the cache will invalidate the value for that key and return null. An example version key might be the count of an array, if the count changes, you want to invalidate the cached object.

Note that on a time-expiring cache, if you do not use the reaper with startBackgroundExpiration(), or manually call removeStaleEntries(), unexpired entries will remain in the cache for the lifetime of the cache.

Author:: ak
mschrag

Constructor & Destructor Documentation

ERXExpiringCache ( )

Constructs an ERXExpiringCache with a 60 second expiration.

ERXExpiringCache ( long expiryTimeInSeconds )

Constructs an ERXExpiringCache with a cleanup time that matches expiryTimeInSeconds.

Parameters:

expiryTimeInSeconds

the lifetime in seconds of an object in the cache or NO_TIMEOUT

ERXExpiringCache	(	long	expiryTimeInSeconds,
		long	cleanupPauseInSeconds
	)

Parameters:

	expiryTimeInSeconds	the lifetime in seconds of an object in the cache or NO_TIMEOUT
	cleanupPauseInSeconds	the number of seconds to pause between cleanups

Member Function Documentation

synchronized NSArray<K> allKeys ( )

Returns all keys.

synchronized Entry<V> entryForKey ( K key ) [protected]

long expiryTime ( ) [private]

synchronized boolean isStale ( K key )

Returns whether or not the object for the given key is a stale cache entry.

Parameters:

key

the key to lookup

Returns:: true if the value is stale

synchronized boolean isStaleWithVersion	(	K	key,
		Object	currentVersionKey
	)

Returns whether or not the object for the given key is a stale cache entry given the context of the current version of the key.

Parameters:

	key	the key to lookup
	currentVersionKey	the current version of this key

Returns:: true if the value is stale

synchronized V objectForKey ( K key )

Returns the value of the given key with an unspecified version.

Parameters:

key

the key to lookup with

Returns:: the value in the cache or null

synchronized V objectForKeyWithVersion	(	K	key,
		Object	currentVersionKey
	)

Returns the value of the given key passing in the current version of the cache value. If the version key passed in does not match the version key in the cache, the cache will invalidate that key.

Parameters:

	key	the key to lookup with
	currentVersionKey	the current version of this key

Returns:: the value in the cache or null

static synchronized ERXExpiringCache.GrimReaper reaper ( ) [static, protected]

Returns the repear for all ERXExpringCaches.

Returns:: the repear for all ERXExpringCaches

synchronized void removeAllObjects ( )

Removes all the objects in this cache.

synchronized void removeEntryForKey	(	Entry< V >	entry,
		K	key
	)			`[protected]`

synchronized V removeObjectForKey ( K key )

Removes the object for the given key.

Parameters:

key

the key to remove

Returns:: the removed object

synchronized void removeStaleEntries ( )

Removes all stale entries.

synchronized void setEntryForKey	(	Entry< V >	entry,
		K	key
	)			`[protected]`

synchronized void setObjectForKey	(	V	object,
		K	key
	)

Sets the object for the specified key in this cache with no version specified.

Parameters:

	object	the value to set
	key	the lookup key

synchronized void setObjectForKeyWithVersion	(	V	object,
		K	key,
		Object	currentVersionKey
	)

Sets the object for the specified key and current version key.

Parameters:

	object	the object to set
	key	the lookup key
	currentVersionKey	the version of the object right now

synchronized void setObjectForKeyWithVersion	(	V	object,
		K	key,
		Object	currentVersionKey,
		long	expirationTime
	)

Sets the object for the specified key and current version key.

Parameters:

	object	the object to set
	key	the lookup key
	currentVersionKey	the version of the object right now

void startBackgroundExpiration ( )

Adds this cache to the background thread that reaps time-expired entries from expiring caches. If this cache is not a time-expiration cache, this will throw an IllegalArgumentException.

synchronized void stopBackgroundExpiration ( )

Stops the background reaper for this cache.

String toString ( )

Member Data Documentation

NSMutableDictionary<K, ERXExpiringCache.Entry<V> > _backingDictionary [private]

long _cleanupPause [private]

long _expiryTime [private]

long _lastCleanupTime [private]

ERXExpiringCache.GrimReaper _reaper [static, private]

The reaper for ERXExpiringCaches.

final long NO_TIMEOUT = 0L [static]

Designates that no timeout was specified.

final Object NO_VERSION = new Object() [static]

Designates that no explicit version was specified.

The documentation for this class was generated from the following file:

/opt/source/Wonder/Frameworks/Core/ERExtensions/Sources/er/extensions/foundation/ERXExpiringCache.java


Classes
class	Entry< V >
class	GrimReaper
Public Member Functions
synchronized NSArray< K >	allKeys ()
	ERXExpiringCache (long expiryTimeInSeconds, long cleanupPauseInSeconds)
	ERXExpiringCache (long expiryTimeInSeconds)
	ERXExpiringCache ()
synchronized boolean	isStale (K key)
synchronized boolean	isStaleWithVersion (K key, Object currentVersionKey)
synchronized V	objectForKey (K key)
synchronized V	objectForKeyWithVersion (K key, Object currentVersionKey)
synchronized void	removeAllObjects ()
synchronized V	removeObjectForKey (K key)
synchronized void	removeStaleEntries ()
synchronized void	setObjectForKey (V object, K key)
synchronized void	setObjectForKeyWithVersion (V object, K key, Object currentVersionKey)
synchronized void	setObjectForKeyWithVersion (V object, K key, Object currentVersionKey, long expirationTime)
void	startBackgroundExpiration ()
synchronized void	stopBackgroundExpiration ()
String	toString ()
Static Public Attributes
static final long	NO_TIMEOUT = 0L
static final Object	NO_VERSION = new Object()
Protected Member Functions
synchronized Entry< V >	entryForKey (K key)
synchronized void	removeEntryForKey (Entry< V > entry, K key)
synchronized void	setEntryForKey (Entry< V > entry, K key)
Static Protected Member Functions
static synchronized ERXExpiringCache.GrimReaper	reaper ()
Private Member Functions
long	expiryTime ()
Private Attributes
NSMutableDictionary< K, ERXExpiringCache.Entry< V > >	_backingDictionary
long	_cleanupPause
long	_expiryTime
long	_lastCleanupTime
Static Private Attributes
static ERXExpiringCache.GrimReaper	_reaper