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CDummyCache

Package	system.caching
Inheritance	class CDummyCache » CApplicationComponent » CComponent
Implements	IApplicationComponent, ICache, ArrayAccess
Since	1.0
Version	$Id: CDummyCache.php 1678 2010-01-07 21:02:00Z qiang.xue $

CDummyCache is a placeholder cache component.

CDummyCache does not do/cache anything. It is used as the default 'cache' application component.

Public Properties

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Property	Type	Description	Defined By
behaviors	array	the behaviors that should be attached to this component.	CApplicationComponent
isInitialized	boolean	whether this application component has been initialized (i.	CApplicationComponent
keyPrefix	string	a string prefixed to every cache key so that it is unique.	CDummyCache

Public Methods

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Method	Description	Defined By
__call()	Calls the named method which is not a class method.	CComponent
__get()	Returns a property value, an event handler list or a behavior based on its name.	CComponent
__isset()	Checks if a property value is null.	CComponent
__set()	Sets value of a component property.	CComponent
__unset()	Sets a component property to be null.	CComponent
add()	Stores a value identified by a key into cache if the cache does not contain this key.	CDummyCache
asa()	Returns the named behavior object.	CComponent
attachBehavior()	Attaches a behavior to this component.	CComponent
attachBehaviors()	Attaches a list of behaviors to the component.	CComponent
attachEventHandler()	Attaches an event handler to an event.	CComponent
canGetProperty()	Determines whether a property can be read.	CComponent
canSetProperty()	Determines whether a property can be set.	CComponent
delete()	Deletes a value with the specified key from cache	CDummyCache
detachBehavior()	Detaches a behavior from the component.	CComponent
detachBehaviors()	Detaches all behaviors from the component.	CComponent
detachEventHandler()	Detaches an existing event handler.	CComponent
disableBehavior()	Disables an attached behavior.	CComponent
disableBehaviors()	Disables all behaviors attached to this component.	CComponent
enableBehavior()	Enables an attached behavior.	CComponent
enableBehaviors()	Enables all behaviors attached to this component.	CComponent
evaluateExpression()	Evaluates a PHP expression or callback under the context of this component.	CComponent
flush()	Deletes all values from cache.	CDummyCache
get()	Retrieves a value from cache with a specified key.	CDummyCache
getEventHandlers()	Returns the list of attached event handlers for an event.	CComponent
getIsInitialized()		CApplicationComponent
hasEvent()	Determines whether an event is defined.	CComponent
hasEventHandler()	Checks whether the named event has attached handlers.	CComponent
hasProperty()	Determines whether a property is defined.	CComponent
init()	Initializes the application component.	CDummyCache
mget()	Retrieves multiple values from cache with the specified keys.	CDummyCache
offsetExists()	Returns whether there is a cache entry with a specified key.	CDummyCache
offsetGet()	Retrieves the value from cache with a specified key.	CDummyCache
offsetSet()	Stores the value identified by a key into cache.	CDummyCache
offsetUnset()	Deletes the value with the specified key from cache	CDummyCache
raiseEvent()	Raises an event.	CComponent
set()	Stores a value identified by a key into cache.	CDummyCache

Property Details

keyPrefix property

public string $keyPrefix;

a string prefixed to every cache key so that it is unique. Defaults to application ID.

Method Details

add() method

public boolean add(string $id, mixed $value, integer $expire=0, ICacheDependency $dependency=NULL)
$id	string	the key identifying the value to be cached
$value	mixed	the value to be cached
$expire	integer	the number of seconds in which the cached value will expire. 0 means never expire.
$dependency	ICacheDependency	dependency of the cached item. If the dependency changes, the item is labeled invalid.
{return}	boolean	true if the value is successfully stored into cache, false otherwise

Stores a value identified by a key into cache if the cache does not contain this key. Nothing will be done if the cache already contains the key.

delete() method

public boolean delete(string $id)
$id	string	the key of the value to be deleted
{return}	boolean	if no error happens during deletion

Deletes a value with the specified key from cache

flush() method

public void flush()

Deletes all values from cache. Be careful of performing this operation if the cache is shared by multiple applications. Child classes may implement this method to realize the flush operation.

get() method

public mixed get(string $id)
$id	string	a key identifying the cached value
{return}	mixed	the value stored in cache, false if the value is not in the cache, expired or the dependency has changed.

Retrieves a value from cache with a specified key.

init() method

public void init()

Initializes the application component. This method overrides the parent implementation by setting default cache key prefix.

mget() method (available since v1.0.8)

public array mget(array $ids)
$ids	array	list of keys identifying the cached values
{return}	array	list of cached values corresponding to the specified keys. The array is returned in terms of (key,value) pairs. If a value is not cached or expired, the corresponding array value will be false.

Retrieves multiple values from cache with the specified keys. Some caches (such as memcache, apc) allow retrieving multiple cached values at one time, which may improve the performance since it reduces the communication cost. In case a cache doesn't support this feature natively, it will be simulated by this method.

offsetExists() method

public boolean offsetExists(string $id)
$id	string	a key identifying the cached value
{return}	boolean

Returns whether there is a cache entry with a specified key. This method is required by the interface ArrayAccess.

offsetGet() method

public mixed offsetGet(string $id)
$id	string	a key identifying the cached value
{return}	mixed	the value stored in cache, false if the value is not in the cache or expired.

Retrieves the value from cache with a specified key. This method is required by the interface ArrayAccess.

offsetSet() method

public void offsetSet(string $id, mixed $value)
$id	string	the key identifying the value to be cached
$value	mixed	the value to be cached

Stores the value identified by a key into cache. If the cache already contains such a key, the existing value will be replaced with the new ones. To add expiration and dependencies, use the set() method. This method is required by the interface ArrayAccess.

offsetUnset() method

public boolean offsetUnset(string $id)
$id	string	the key of the value to be deleted
{return}	boolean	if no error happens during deletion

Deletes the value with the specified key from cache This method is required by the interface ArrayAccess.

set() method

public boolean set(string $id, mixed $value, integer $expire=0, ICacheDependency $dependency=NULL)
$id	string	the key identifying the value to be cached
$value	mixed	the value to be cached
$expire	integer	the number of seconds in which the cached value will expire. 0 means never expire.
$dependency	ICacheDependency	dependency of the cached item. If the dependency changes, the item is labeled invalid.
{return}	boolean	true if the value is successfully stored into cache, false otherwise

Stores a value identified by a key into cache. If the cache already contains such a key, the existing value and expiration time will be replaced with the new ones.