/modules/cache/classes/kohana/cache/memcache.php
PHP | 268 lines | 74 code | 21 blank | 173 comment | 5 complexity | 03f8b8785bf0db3fb708fdf32523005b MD5 | raw file
- <?php defined('SYSPATH') or die('No direct script access.');
- /**
- * [Kohana Cache](api/Kohana_Cache) Memcache driver,
- *
- * ### Supported cache engines
- *
- * * [Memcache](http://www.php.net/manual/en/book.memcache.php)
- * * [Memcached-tags](http://code.google.com/p/memcached-tags/)
- *
- * ### Configuration example
- *
- * Below is an example of a _memcache_ server configuration.
- *
- * return array(
- * 'default' => array( // Default group
- * 'driver' => 'memcache', // using Memcache driver
- * 'servers' => array( // Available server definitions
- * // First memcache server server
- * array(
- * 'host' => 'localhost',
- * 'port' => 11211,
- * 'persistent' => FALSE
- * 'weight' => 1,
- * 'timeout' => 1,
- * 'retry_interval' => 15,
- * 'status' => TRUE,
- * 'failure_callback' => array('className', 'classMethod')
- * ),
- * // Second memcache server
- * array(
- * 'host' => '192.168.1.5',
- * 'port' => 22122,
- * 'persistent' => TRUE
- * )
- * ),
- * 'compression' => FALSE, // Use compression?
- * ),
- * )
- *
- * In cases where only one cache group is required, if the group is named `default` there is
- * no need to pass the group name when instantiating a cache instance.
- *
- * #### General cache group configuration settings
- *
- * Below are the settings available to all types of cache driver.
- *
- * Name | Required | Description
- * -------------- | -------- | ---------------------------------------------------------------
- * driver | __YES__ | (_string_) The driver type to use
- * servers | __YES__ | (_array_) Associative array of server details, must include a __host__ key. (see _Memcache server configuration_ below)
- * compression | __NO__ | (_boolean_) Use data compression when caching
- *
- * #### Memcache server configuration
- *
- * The following settings should be used when defining each memcache server
- *
- * Name | Required | Description
- * ---------------- | -------- | ---------------------------------------------------------------
- * host | __YES__ | (_string_) The host of the memcache server, i.e. __localhost__; or __127.0.0.1__; or __memcache.domain.tld__
- * port | __NO__ | (_integer_) Point to the port where memcached is listening for connections. Set this parameter to 0 when using UNIX domain sockets. Default __11211__
- * persistent | __NO__ | (_boolean_) Controls the use of a persistent connection. Default __TRUE__
- * weight | __NO__ | (_integer_) Number of buckets to create for this server which in turn control its probability of it being selected. The probability is relative to the total weight of all servers. Default __1__
- * timeout | __NO__ | (_integer_) Value in seconds which will be used for connecting to the daemon. Think twice before changing the default value of 1 second - you can lose all the advantages of caching if your connection is too slow. Default __1__
- * retry_interval | __NO__ | (_integer_) Controls how often a failed server will be retried, the default value is 15 seconds. Setting this parameter to -1 disables automatic retry. Default __15__
- * status | __NO__ | (_boolean_) Controls if the server should be flagged as online. Default __TRUE__
- * failure_callback | __NO__ | (_[callback](http://www.php.net/manual/en/language.pseudo-types.php#language.types.callback)_) Allows the user to specify a callback function to run upon encountering an error. The callback is run before failover is attempted. The function takes two parameters, the hostname and port of the failed server. Default __NULL__
- *
- * ### System requirements
- *
- * * Kohana 3.0.x
- * * PHP 5.2.4 or greater
- * * Memcache (plus Memcached-tags for native tagging support)
- * * Zlib
- *
- * @package Kohana
- * @category Cache
- * @version 2.0
- * @author Kohana Team
- * @copyright (c) 2009-2010 Kohana Team
- * @license http://kohanaphp.com/license
- */
- class Kohana_Cache_Memcache extends Cache {
- // Memcache has a maximum cache lifetime of 30 days
- const CACHE_CEILING = 2592000;
- /**
- * Memcache resource
- *
- * @var Memcache
- */
- protected $_memcache;
- /**
- * Flags to use when storing values
- *
- * @var string
- */
- protected $_flags;
- /**
- * Constructs the memcache Kohana_Cache object
- *
- * @param array configuration
- * @throws Kohana_Cache_Exception
- */
- protected function __construct(array $config)
- {
- // Check for the memcache extention
- if ( ! extension_loaded('memcache'))
- {
- throw new Kohana_Cache_Exception('Memcache PHP extention not loaded');
- }
- parent::__construct($config);
- // Setup Memcache
- $this->_memcache = new Memcache;
- // Load servers from configuration
- $servers = Arr::get($this->_config, 'servers', NULL);
- if ( ! $servers)
- {
- // Throw an exception if no server found
- throw new Kohana_Cache_Exception('No Memcache servers defined in configuration');
- }
- // Setup default server configuration
- $config = array(
- 'host' => 'localhost',
- 'port' => 11211,
- 'persistent' => FALSE,
- 'weight' => 1,
- 'timeout' => 1,
- 'retry_interval' => 15,
- 'status' => TRUE,
- 'failure_callback' => NULL,
- );
- // Add the memcache servers to the pool
- foreach ($servers as $server)
- {
- // Merge the defined config with defaults
- $server += $config;
- if ( ! $this->_memcache->addServer($server['host'], $server['port'], $server['persistent'], $server['weight'], $server['timeout'], $server['retry_interval'], $server['status'], $server['failure_callback']))
- {
- throw new Kohana_Cache_Exception('Memcache could not connect to host \':host\' using port \':port\'', array(':host' => $server['host'], ':port' => $server['port']));
- }
- }
- // Setup the flags
- $this->_flags = Arr::get($this->_config, 'compression', FALSE) ? MEMCACHE_COMPRESSED : FALSE;
- }
- /**
- * Retrieve a cached value entry by id.
- *
- * // Retrieve cache entry from memcache group
- * $data = Cache::instance('memcache')->get('foo');
- *
- * // Retrieve cache entry from memcache group and return 'bar' if miss
- * $data = Cache::instance('memcache')->get('foo', 'bar');
- *
- * @param string id of cache to entry
- * @param string default value to return if cache miss
- * @return mixed
- * @throws Kohana_Cache_Exception
- */
- public function get($id, $default = NULL)
- {
- // Get the value from Memcache
- $value = $this->_memcache->get($this->_sanitize_id($id));
- // If the value wasn't found, normalise it
- if ($value === FALSE)
- {
- $value = (NULL === $default) ? NULL : $default;
- }
- // Return the value
- return $value;
- }
- /**
- * Set a value to cache with id and lifetime
- *
- * $data = 'bar';
- *
- * // Set 'bar' to 'foo' in memcache group for 10 minutes
- * if (Cache::instance('memcache')->set('foo', $data, 600))
- * {
- * // Cache was set successfully
- * return
- * }
- *
- * @param string id of cache entry
- * @param mixed data to set to cache
- * @param integer lifetime in seconds, maximum value 2592000
- * @return boolean
- */
- public function set($id, $data, $lifetime = 3600)
- {
- // If the lifetime is greater than the ceiling
- if ($lifetime > Cache_Memcache::CACHE_CEILING)
- {
- // Set the lifetime to maximum cache time
- $lifetime = Cache_Memcache::CACHE_CEILING + time();
- }
- // Else if the lifetime is greater than zero
- elseif ($lifetime > 0)
- {
- $lifetime += time();
- }
- // Else
- else
- {
- // Normalise the lifetime
- $lifetime = 0;
- }
- // Set the data to memcache
- return $this->_memcache->set($this->_sanitize_id($id), $data, $this->_flags, $lifetime);
- }
- /**
- * Delete a cache entry based on id
- *
- * // Delete the 'foo' cache entry immediately
- * Cache::instance('memcache')->delete('foo');
- *
- * // Delete the 'bar' cache entry after 30 seconds
- * Cache::instance('memcache')->delete('bar', 30);
- *
- * @param string id of entry to delete
- * @param integer timeout of entry, if zero item is deleted immediately, otherwise the item will delete after the specified value in seconds
- * @return boolean
- */
- public function delete($id, $timeout = 0)
- {
- // Delete the id
- return $this->_memcache->delete($this->_sanitize_id($id), $timeout);
- }
- /**
- * Delete all cache entries.
- *
- * Beware of using this method when
- * using shared memory cache systems, as it will wipe every
- * entry within the system for all clients.
- *
- * // Delete all cache entries in the default group
- * Cache::instance('memcache')->delete_all();
- *
- * @return boolean
- */
- public function delete_all()
- {
- $result = $this->_memcache->flush();
- // We must sleep after flushing, or overwriting will not work!
- // @see http://php.net/manual/en/function.memcache-flush.php#81420
- sleep(1);
- return $result;
- }
- }