Class **Phalcon\\Cache\\Backend\\Libmemcached**
===============================================

*extends* abstract class :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

*implements* :doc:`Phalcon\\Cache\\BackendInterface <Phalcon_Cache_BackendInterface>`

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:raw-html:`<a href="https://github.com/phalcon/cphalcon/blob/master/phalcon/cache/backend/libmemcached.zep" class="btn btn-default btn-sm">Source on GitHub</a>`

Allows to cache output fragments, PHP data or raw data to a libmemcached backend. Per default persistent memcached connection pools are used.  

.. code-block:: php

    <?php

     use Phalcon\Cache\Backend\Libmemcached;
     use Phalcon\Cache\Frontend\Data as FrontData;
    
     // Cache data for 2 days
     $frontCache = new FrontData([
         'lifetime' => 172800
     ]);
    
     // Create the Cache setting memcached connection options
     $cache = new Libmemcached($frontCache, [
         'servers' => [
             [
                 'host' => 'localhost',
                 'port' => 11211,
                 'weight' => 1
             ],
         ],
         'client' => [
             \Memcached::OPT_HASH => Memcached::HASH_MD5,
             \Memcached::OPT_PREFIX_KEY => 'prefix.',
         ]
     ]);
    
     // Cache arbitrary data
     $cache->save('my-data', [1, 2, 3, 4, 5]);
    
     // Get data
     $data = $cache->get('my-data');



Methods
-------

public  **__construct** (:doc:`Phalcon\\Cache\\FrontendInterface <Phalcon_Cache_FrontendInterface>` $frontend, [*array* $options])

Phalcon\\Cache\\Backend\\Memcache constructor



public  **_connect** ()

Create internal connection to memcached



public  **get** (*mixed* $keyName, [*mixed* $lifetime])

Returns a cached content



public  **save** ([*int* | *string* $keyName], [*string* $content], [*long* $lifetime], [*boolean* $stopBuffer])

Stores cached content into the file backend and stops the frontend



public *boolean* **delete** (*int* | *string* $keyName)

Deletes a value from the cache by its key



public *array* **queryKeys** ([*string* $prefix])

Query the existing cached keys



public *boolean* **exists** ([*string* $keyName], [*long* $lifetime])

Checks if cache exists and it isn't expired



public *long* **increment** ([*string* $keyName], [*mixed* $value])

Increment of given $keyName by $value



public *long* **decrement** ([*string* $keyName], [*long* $value])

Decrement of $keyName by given $value



public  **flush** ()

Immediately invalidates all existing items. Memcached does not support flush() per default. If you require flush() support, set $config["statsKey"]. All modified keys are stored in "statsKey". Note: statsKey has a negative performance impact. 

.. code-block:: php

    <?php

     $cache = new \Phalcon\Cache\Backend\Libmemcached($frontCache, ["statsKey" => "_PHCM"]);
     $cache->save('my-data', array(1, 2, 3, 4, 5));
    
     //'my-data' and all other used keys are deleted
     $cache->flush();




public  **getFrontend** () inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

...


public  **setFrontend** (*mixed* $frontend) inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

...


public  **getOptions** () inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

...


public  **setOptions** (*mixed* $options) inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

...


public  **getLastKey** () inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

...


public  **setLastKey** (*mixed* $lastKey) inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

...


public *mixed* **start** (*int* | *string* $keyName, [*int* $lifetime]) inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

Starts a cache. The keyname allows to identify the created fragment



public  **stop** ([*mixed* $stopBuffer]) inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

Stops the frontend without store any cached content



public  **isFresh** () inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

Checks whether the last cache is fresh or cached



public  **isStarted** () inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

Checks whether the cache has starting buffering or not



public *int* **getLifetime** () inherited from :doc:`Phalcon\\Cache\\Backend <Phalcon_Cache_Backend>`

Gets the last lifetime set