# Class yii\caching\XCache

Inheritance | yii\caching\XCache » yii\caching\Cache » yii\base\Component » yii\base\BaseObject
Implements | yii\base\Configurable, yii\caching\CacheInterface
Available since version | 2.0
Deprecated since version | since 2.0.14. This class will be removed in 2.1.0.
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/caching/XCache.php

XCache provides XCache caching in terms of an application component.

To use this application component, the XCache PHP extension must be loaded. Also note that the flush() functionality will work correctly only if "xcache.admin.enable_auth" is set to "Off" in php.ini.

See yii\caching\Cache for common cache operations that XCache supports.

For more details and usage information on Cache, see the guide article on caching.

## Public Properties

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Property | Type | Description | Defined By
--- | --- | --- | ---
$behaviors | yii\base\Behavior[] | List of behaviors attached to this component. This property is read-only. | yii\base\Component
$defaultDuration | integer | Default duration in seconds before a cache entry will expire. | yii\caching\Cache
$keyPrefix | string | A string prefixed to every cache key so that it is unique globally in the whole cache storage. | yii\caching\Cache
$serializer | null|array|false | The functions used to serialize and unserialize cached data. | yii\caching\Cache

## Public Methods

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Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\Component
__clone() | This method is called after the object is created by cloning an existing one. | yii\base\Component
__construct() | Constructor. | yii\base\BaseObject
__get() | Returns the value of a component property. | yii\base\Component
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\Component
__set() | Sets the value of a component property. | yii\base\Component
__unset() | Sets a component property to be null. | yii\base\Component
add() | Stores a value identified by a key into cache if the cache does not contain this key. | yii\caching\Cache
attachBehavior() | Attaches a behavior to this component. | yii\base\Component
attachBehaviors() | Attaches a list of behaviors to the component. | yii\base\Component
behaviors() | Returns a list of behaviors that this component should behave as. | yii\base\Component
buildKey() | Builds a normalized cache key from a given key. | yii\caching\Cache
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\Component
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\Component
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
delete() | Deletes a value with the specified key from cache. | yii\caching\Cache
detachBehavior() | Detaches a behavior from the component. | yii\base\Component
detachBehaviors() | Detaches all behaviors from the component. | yii\base\Component
ensureBehaviors() | Makes sure that the behaviors declared in behaviors() are attached to this component. | yii\base\Component
exists() | Checks whether a specified key exists in the cache. | yii\caching\XCache
flush() | Deletes all values from cache. | yii\caching\Cache
get() | Retrieves a value from cache with a specified key. | yii\caching\Cache
getBehavior() | Returns the named behavior object. | yii\base\Component
getBehaviors() | Returns all behaviors attached to this component. | yii\base\Component
getOrSet() | Method combines both set() and get() methods to retrieve value identified by a $key, or to store the result of $callable execution if there is no cache available for the $key. | yii\caching\Cache
hasEventHandlers() | Returns a value indicating whether there is any handler attached to the named event. | yii\base\Component
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\Component
hasProperty() | Returns a value indicating whether a property is defined for this component. | yii\base\Component
init() | Initializes the object. | yii\caching\Cache
madd() | Stores multiple items in cache. Each item contains a value identified by a key. | yii\caching\Cache
mget() | Retrieves multiple values from cache with the specified keys. | yii\caching\Cache
mset() | Stores multiple items in cache. Each item contains a value identified by a key. | yii\caching\Cache
multiAdd() | Stores multiple items in cache. Each item contains a value identified by a key. | yii\caching\Cache
multiGet() | Retrieves multiple values from cache with the specified keys. | yii\caching\Cache
multiSet() | Stores multiple items in cache. Each item contains a value identified by a key. | yii\caching\Cache
off() | Detaches an existing event handler from this component. | yii\base\Component
offsetExists() | Returns whether there is a cache entry with a specified key. | yii\caching\Cache
offsetGet() | Retrieves the value from cache with a specified key. | yii\caching\Cache
offsetSet() | Stores the value identified by a key into cache. | yii\caching\Cache
offsetUnset() | Deletes the value with the specified key from cache This method is required by the interface ArrayAccess. | yii\caching\Cache
on() | Attaches an event handler to an event. | yii\base\Component
set() | Stores a value identified by a key into cache. | yii\caching\Cache
trigger() | Triggers an event. | yii\base\Component

## Protected Methods

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Method | Description | Defined By
--- | --- | ---
addValue() | Stores a value identified by a key into cache if the cache does not contain this key. | yii\caching\XCache
addValues() | Adds multiple key-value pairs to cache. | yii\caching\Cache
deleteValue() | Deletes a value with the specified key from cache This is the implementation of the method declared in the parent class. | yii\caching\XCache
flushValues() | Deletes all values from cache. | yii\caching\XCache
getValue() | Retrieves a value from cache with a specified key. | yii\caching\XCache
getValues() | Retrieves multiple values from cache with the specified keys. | yii\caching\Cache
setValue() | Stores a value identified by a key in cache. | yii\caching\XCache
setValues() | Stores multiple key-value pairs in cache. | yii\caching\Cache

## Method Details

addValue() protected method

Stores a value identified by a key into cache if the cache does not contain this key.

This is the implementation of the method declared in the parent class.

protected boolean addValue ( $key, $value, $duration )
$key | string | The key identifying the value to be cached
$value | mixed | The value to be cached. Most often it's a string. If you have disabled $serializer, it could be something else.
$duration | integer | The number of seconds in which the cached value will expire. 0 means never expire.
return | boolean | True if the value is successfully stored into cache, false otherwise

deleteValue() protected method

Deletes a value with the specified key from cache This is the implementation of the method declared in the parent class.

protected boolean deleteValue ( $key )
$key | string | The key of the value to be deleted
return | boolean | If no error happens during deletion

exists() public method

Checks whether a specified key exists in the cache.

This can be faster than getting the value from the cache if the data is big. Note that this method does not check whether the dependency associated with the cached data, if there is any, has changed. So a call to get() may return false while exists returns true.

public boolean exists ( $key )
$key | mixed | A key identifying the cached value. This can be a simple string or a complex data structure consisting of factors representing the key.
return | boolean | True if a value exists in cache, false if the value is not in the cache or expired.

flushValues() protected method

Deletes all values from cache.

This is the implementation of the method declared in the parent class.

protected boolean flushValues ( )
return | boolean | Whether the flush operation was successful.

getValue() protected method

Retrieves a value from cache with a specified key.

This is the implementation of the method declared in the parent class.

protected mixed|false getValue ( $key )
$key | string | A unique key identifying the cached value
return | mixed|false | The value stored in cache, false if the value is not in the cache or expired.

setValue() protected method

Stores a value identified by a key in cache.

This is the implementation of the method declared in the parent class.

protected boolean setValue ( $key, $value, $duration )
$key | string | The key identifying the value to be cached
$value | mixed | The value to be cached. Most often it's a string. If you have disabled $serializer, it could be something else.
$duration | integer | The number of seconds in which the cached value will expire. 0 means never expire.
return | boolean | True if the value is successfully stored into cache, false otherwise