Class \Prado\Caching\TMemCache

TMemCache class

TMemCache implements a cache application module based on memcached.

TMemCache can be configured with the Host and Port properties, which specify the host and port of the memcache server to be used. By default, they take the value 'localhost' and 11211, respectively. These properties must be set before init is invoked.

The following basic cache operations are implemented:

get : retrieve the value with a key (if any) from cache
set : store the value with a key into cache
add : store the value only if cache does not have this key
delete : delete the value with the specified key from cache
flush : delete all values from cache

Each value is associated with an expiration time. The get operation ensures that any expired value will not be returned. The expiration time can be specified by the number of seconds (maximum 606024*30) or a UNIX timestamp. A expiration time 0 represents never expire.

By definition, cache does not ensure the existence of a value even if it never expires. Cache is not meant to be an persistent storage.

Also note, there is no security measure to protected data in memcache. All data in memcache can be accessed by any process running in the system.

To use this module, the memcached PHP extension must be loaded.

Some usage examples of TMemCache are as follows,

$cache=new TMemCache;  // TMemCache may also be loaded as a Prado application module
$cache->init(null);
$cache->add('object',$object);
$object2=$cache->get('object');

You can configure TMemCache two different ways. If you only need one memcache server you may use the method as follows.

<module id="cache" class="Prado\Caching\TMemCache" Host="localhost" Port="11211" />

If you want a more complex configuration, you may use the method as follows.

<module id="cache" class="Prado\Caching\TMemCache">
    <server Host="localhost" Port="11211" Weight="1" />
    <server Host="anotherhost" Port="11211" Weight="1" />
</module>

If loaded, TMemCache will register itself with TApplication as the cache module. It can be accessed via TApplication::getCache().

TMemCache may be configured in application configuration file as follows

<module id="cache" class="Prado\Caching\TMemCache" Host="localhost" Port="11211" />

where \Prado\Caching\getHost and \Prado\Caching\getPort are configurable properties of TMemCache.

By default the Memcached instances are destroyed at the end of the request. To create an instance that persists between requests, set a persistent ID using \Prado\Caching\setPersistentID. All instances created with the same persistent_id will share the same connection.

Class hierarchy

\Prado\Caching\TMemCache

\Prado\Caching\TCache implements ICache, ArrayAccess

\Prado\TModule implements IModule

\Prado\TApplicationComponent

\Prado\TComponent

Author: Qiang Xue <qiang.xue@gmail.com>
Since: 3.0

Methods summary
`public`	`__destruct() : mixed` Destructor. Disconnect the memcache server.
`public`	`flush() : bool` Deletes all values from cache. Be careful of performing this operation if the cache is shared by multiple applications.
`public`	`getHost() : string`
`public`	`getPersistentID() : string`
`public`	`getPort() : int`
`public`	`init(TXmlElement $config) : mixed` Initializes this module. This method is required by the IModule interface. It makes sure that UniquePrefix has been set, creates a Memcache instance and connects to the memcache server.
`public`	`setHost(string $value) : mixed`
`public`	`setOptions(array<string\|int, mixed> $value) : mixed`
`public`	`setPersistentID(string $value) : mixed`
`public`	`setPort(int $value) : mixed`
`public deprecated`	`setUseMemcached(string $value) : mixed`
`protected`	`addValue(string $key, string $value, int $expire) : bool` 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`	`deleteValue(string $key) : bool` Deletes a value with the specified key from cache This is the implementation of the method declared in the parent class.
`protected`	`getValue(string $key) : false\|string` Retrieves a value from cache with a specified key. This is the implementation of the method declared in the parent class.
`protected`	`setValue(string $key, string $value, int $expire) : bool` Stores a value identified by a key in cache. This is the implementation of the method declared in the parent class.
`private`	`loadConfig(TXmlElement $xml) : mixed` Loads configuration from an XML element

Inherited methods
__call, __callStatic, __clone, __construct, __destruct, __get, __isset, __set, __sleep, __unset, __wakeup, add, addParsedObject, asa, attachBehavior, attachBehaviors, attachClassBehavior, attachEventHandler, callBehaviorsMethod, canGetProperty, canSetProperty, clearBehaviors, createdOnTemplate, delete, detachBehavior, detachBehaviors, detachClassBehavior, detachEventHandler, disableBehavior, disableBehaviors, enableBehavior, enableBehaviors, evaluateExpression, evaluateStatements, flush, fxAttachClassBehavior, fxDetachClassBehavior, get, getApplication, getAutoGlobalListen, getBehaviors, getBehaviorsEnabled, getClassHierarchy, getEventHandlers, getID, getKeyPrefix, getListeningToGlobalEvents, getPrimaryCache, getRequest, getResponse, getService, getSession, getSubProperty, getUser, hasEvent, hasEventHandler, hasMethod, hasProperty, init, isa, listen, offsetExists, offsetGet, offsetSet, offsetUnset, publishAsset, publishFilePath, raiseEvent, set, setID, setKeyPrefix, setPrimaryCache, setSubProperty, unlisten, _getZappableSleepProps, addValue, deleteValue, generateUniqueKey, getCallChain, getClassFxEvents, getValue, instanceBehavior, setValue, filter_prado_fx

Inherited constants
`\Prado\TApplicationComponent::FX_CACHE_FILE, \Prado\TComponent::GLOBAL_RAISE_EVENT_LISTENER`

Classes

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Class \Prado\Caching\TMemCache

Class hierarchy