PHP Class Prado\Caching\TMemCache

TMemCache implements a cache application module based on {@link http://www.danga.com/memcached/ 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 {@link init} is invoked. The following basic cache operations are implemented: - {@link get} : retrieve the value with a key (if any) from cache - {@link set} : store the value with a key into cache - {@link add} : store the value only if cache does not have this key - {@link delete} : delete the value with the specified key from cache - {@link flush} : delete all values from cache Each value is associated with an expiration time. The {@link get} operation ensures that any expired value will not be returned. The expiration time can be specified by the number of seconds (maximum 60*60*24*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 memcache 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.

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

If loaded, TMemCache will register itself with {@link TApplication} as the cache module. It can be accessed via {@link TApplication::getCache()}. TMemCache may be configured in application configuration file as follows

where {@link getHost Host} and {@link getPort Port} are configurable properties of TMemCache. Automatic compression of values may be used (using zlib extension) by setting {@link getThreshold Threshold} and {@link getMinSavings MinSavings} properties. NB : MemCache server(s) must be restarted to apply settings. Require (PECL memcache >= 2.0.0) or memcached if {@link useMemcached} is true.

Since: 3.0

Author: Qiang Xue ([email protected])

Inheritance: extends TCache

Show file Open project: pradosoft/prado

Public Methods

Method	Description
__destruct ( )	Destructor.
flush ( )	Deletes all values from cache.
getHost ( ) : string
getMinSavings ( ) : float
getPort ( ) : integer
getThreshold ( ) : integer
getUseMemcached ( ) : boolean
init ( $config )	Initializes this module.
setHost ( $value )
setMinSavings ( $value )
setPort ( $value )
setThreshold ( $value )
setUseMemcached ( $value )

Protected Methods

Method	Description
addValue ( $key, $value, $expire ) : boolean	Stores a value identified by a key into cache if the cache does not contain this key.
deleteValue ( $key ) : boolean	Deletes a value with the specified key from cache This is the implementation of the method declared in the parent class.
getValue ( $key ) : string	Retrieves a value from cache with a specified key.
setValue ( $key, $value, $expire ) : boolean	Stores a value identified by a key in cache.

Private Methods

Method	Description
loadConfig ( $xml )	Loads configuration from an XML element

Method Details

__destruct() public method

Disconnect the memcache server.

public __destruct ( )

addValue() protected method

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

protected addValue ( $key, $value, $expire ) : boolean
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 deleteValue ( $key ) : boolean
return	boolean	if no error happens during deletion

flush() public method

Be careful of performing this operation if the cache is shared by multiple applications.

public flush ( )

getHost() public method

public getHost ( ) : string
return	string	host name of the memcache server

getMinSavings() public method

public getMinSavings ( ) : float
return	float	minimum amount of savings to actually store the value compressed

getPort() public method

public getPort ( ) : integer
return	integer	port number of the memcache server

getThreshold() public method

public getThreshold ( ) : integer
return	integer	minimum value length before attempting to compress

getUseMemcached() public method

public getUseMemcached ( ) : boolean
return	boolean	if memcached instead memcache

getValue() protected method

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

protected getValue ( $key ) : string
return	string	the value stored in cache, false if the value is not in the cache or expired.

init() public method

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 init ( $config )

setHost() public method

public setHost ( $value )

setMinSavings() public method

public setMinSavings ( $value )

setPort() public method

public setPort ( $value )

setThreshold() public method

public setThreshold ( $value )

setUseMemcached() public method

public setUseMemcached ( $value )

setValue() protected method

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

protected setValue ( $key, $value, $expire ) : boolean
return	boolean	true if the value is successfully stored into cache, false otherwise