egroupware/phpgwapi/inc/class.egw_cache.inc.php
2009-05-26 14:44:29 +00:00

537 lines
18 KiB
PHP

<?php
/**
* eGroupWare API: Caching data
*
* @link http://www.egroupware.org
* @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
* @package api
* @subpackage cache
* @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
* @copyright (c) 2009 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
* @version $Id$
*/
/**
* Class to manage caching in eGroupware.
*
* It allows to cache on 4 levels:
* a) tree: for all instances/domains runining on a certain source path
* b) instance: for all sessions on a given instance
* c) session: for all requests of a session, same as egw_session::appsession()
* d) request: just for this request (same as using a static variable)
*
* There's a get, a set and a unset method for each level: eg. getTree() or setInstance(),
* as well as a variant allowing to specify the level as first parameter: eg. unsetCache()
*
* getXXX($app,$location,$callback=null,array $callback_params,$expiration=0)
* has three optional parameters allowing to specify:
* 3. a callback if requested data is not yes stored. In that case the callback is called
* and it's value is stored in the cache AND retured
* 4. parameters to pass to the callback as array, see call_user_func_array
* 5. an expiration time in seconds to specify how long data should be cached,
* default 0 means infinit (this time is not garantied and not supported for all levels!)
*
* Data is stored under an application name and a location, like egw_session::appsession().
* In fact data stored at cache level egw_cache::SESSION, is stored in the same way as
* egw_session::appsession() so both methods can be used with each other.
*
* The $app parameter should be either the app or the class name, which both are unique.
*
* The tree and instance wide cache uses a certain provider class, to store the data
* eg. in memcached or if there's nothing else configured in the filesystem (eGW's temp_dir).
*/
class egw_cache
{
/**
* tree-wide storage
*/
const TREE = 'Tree';
/**
* instance-wide storage
*/
const INSTANCE = 'Instance';
/**
* session-wide storage
*/
const SESSION = 'Session';
/**
* request-wide storage
*/
const REQUEST = 'Request';
/**
* Default provider for tree and instance data
*
* Can be specified eg. in the header.inc.php by setting:
* $GLOBALS['egw_info']['server']['cache_provider_instance'] and optional
* $GLOBALS['egw_info']['server']['cache_provider_tree'] (defaults to instance)
*
* @var array
*/
static $default_provider = array('egw_cache_files');// array('egw_cache_memcache','localhost');
/**
* Set some data in the cache
*
* @param string $level use egw_cache::(TREE|INSTANCE|SESSION|REQUEST)
* @param string $app application storing data
* @param string $location location name for data
* @param mixed $data
* @param int $expiration=0 expiration time in seconds, default 0 = never
* @return boolean true if data could be stored, false otherwise
*/
static public function setCache($level,$app,$location,$data,$expiration=0)
{
switch($level)
{
case self::SESSION:
case self::REQUEST:
return call_user_func(array(__CLASS__,'set'.$level),$app,$location,$data,$expiration);
case self::INSTANCE:
case self::TREE:
if (!($provider = self::get_provider($level)))
{
return false;
}
return $provider->set(self::keys($level,$app,$location),$data);
}
throw new egw_exception_wrong_parameter(__METHOD__."() unknown level '$level'!");
}
/**
* Get some data from the cache
*
* @param string $level use egw_cache::(TREE|INSTANCE|SESSION|REQUEST)
* @param string $app application storing data
* @param string $location location name for data
* @param callback $callback=null callback to get/create the value, if it's not cache
* @param array $callback_params=null array with parameters for the callback
* @param int $expiration=0 expiration time in seconds, default 0 = never
* @return mixed NULL if data not found in cache (and no callback specified)
*/
static public function getCache($level,$app,$location,$callback=null,array $callback_params=null,$expiration=0)
{
switch($level)
{
case self::SESSION:
case self::REQUEST:
return call_user_func(array(__CLASS__,'get'.$level),$app,$location,$callback,$callback_params,$expiration);
case self::INSTANCE:
case self::TREE:
if (!($provider = self::get_provider($level)))
{
return null;
}
$data = $provider->get($keys=self::keys($level,$app,$location));
if (is_null($data) && !is_null($callback))
{
//error_log(__METHOD__."($level,$app,$location,".array2string($callback).','.array2string($callback_params).",$expiration) calling calback to create data.");
$data = call_user_func_array($callback,$callback_params);
$provider->set($keys,$data);
}
return $data;
}
throw new egw_exception_wrong_parameter(__METHOD__."() unknown level '$level'!");
}
/**
* Unset some data in the cache
*
* @param string $level use egw_cache::(TREE|INSTANCE|SESSION|REQUEST)
* @param string $app application storing data
* @param string $location location name for data
* @return boolean true if data was set, false if not (like isset())
*/
static public function unsetCache($level,$app,$location)
{
switch($level)
{
case self::SESSION:
case self::REQUEST:
return call_user_func(array(__CLASS__,'unset'.$level),$app,$location);
case self::INSTANCE:
case self::TREE:
if (!($provider = self::get_provider($level)))
{
return false;
}
return $provider->delete(self::keys($level,$app,$location));
}
throw new egw_exception_wrong_parameter(__METHOD__."() unknown level '$level'!");
}
/**
* Set some data in the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @param mixed $data
* @param int $expiration=0 expiration time in seconds, default 0 = never
* @return boolean true if data could be stored, false otherwise
*/
static public function setTree($app,$location,$data,$expiration=0)
{
return self::setCache(self::TREE,$app,$location,$data,$expiration);
}
/**
* Get some data from the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @param callback $callback=null callback to get/create the value, if it's not cache
* @param array $callback_params=null array with parameters for the callback
* @param int $expiration=0 expiration time in seconds, default 0 = never
* @return mixed NULL if data not found in cache (and no callback specified)
*/
static public function getTree($app,$location,$callback=null,array $callback_params=null,$expiration=0)
{
return self::getCache(self::TREE,$app,$location,$callback,$callback_params,$expiration);
}
/**
* Unset some data in the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @return boolean true if data was set, false if not (like isset())
*/
static public function unsetTree($app,$location)
{
return self::unsetCache(self::TREE,$app,$location);
}
/**
* Set some data in the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @param mixed $data
* @param int $expiration=0 expiration time in seconds, default 0 = never
* @return boolean true if data could be stored, false otherwise
*/
static public function setInstance($app,$location,$data,$expiration=0)
{
return self::setCache(self::INSTANCE,$app,$location,$data,$expiration);
}
/**
* Get some data from the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @param callback $callback=null callback to get/create the value, if it's not cache
* @param array $callback_params=null array with parameters for the callback
* @param int $expiration=0 expiration time in seconds, default 0 = never
* @return mixed NULL if data not found in cache (and no callback specified)
*/
static public function getInstance($app,$location,$callback=null,array $callback_params=null,$expiration=0)
{
return self::getCache(self::INSTANCE,$app,$location,$callback,$callback_params,$expiration);
}
/**
* Unset some data in the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @return boolean true if data was set, false if not (like isset())
*/
static public function unsetInstance($app,$location)
{
return self::unsetCache(self::INSTANCE,$app,$location);
}
/**
* Set some data in the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @param mixed $data
* @param int $expiration=0 expiration time in seconds, default 0 = never
* @return boolean true if data could be stored, false otherwise
*/
static public function setSession($app,$location,$data,$expiration=0)
{
if (isset($_SESSION[egw_session::EGW_SESSION_ENCRYPTED]))
{
if (egw_session::ERROR_LOG_DEBUG) error_log(__METHOD__.' called after session was encrypted --> ignored!');
return false; // can no longer store something in the session, eg. because commit_session() was called
}
$_SESSION[egw_session::EGW_APPSESSION_VAR][$app][$location] = $data;
return true;
}
/**
* Get some data from the cache for the whole source tree (all instances)
*
* Returns a reference to the var in the session!
*
* @param string $app application storing data
* @param string $location location name for data
* @param callback $callback=null callback to get/create the value, if it's not cache
* @param array $callback_params=null array with parameters for the callback
* @param int $expiration=0 expiration time in seconds, default 0 = never
* @return mixed NULL if data not found in cache (and no callback specified)
*/
static public function &getSession($app,$location,$callback=null,array $callback_params=null,$expiration=0)
{
if (isset($_SESSION[egw_session::EGW_SESSION_ENCRYPTED]))
{
if (egw_session::ERROR_LOG_DEBUG) error_log(__METHOD__.' called after session was encrypted --> ignored!');
return null; // can no longer store something in the session, eg. because commit_session() was called
}
if (!isset($_SESSION[egw_session::EGW_APPSESSION_VAR][$app][$location]) && !is_null($callback))
{
$_SESSION[egw_session::EGW_APPSESSION_VAR][$app][$location] = call_user_func_array($callback,$callback_params);
}
return $_SESSION[egw_session::EGW_APPSESSION_VAR][$app][$location];
}
/**
* Unset some data in the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @return boolean true if data was set, false if not (like isset())
*/
static public function unsetSession($app,$location)
{
if (isset($_SESSION[egw_session::EGW_SESSION_ENCRYPTED]))
{
if (egw_session::ERROR_LOG_DEBUG) error_log(__METHOD__.' called after session was encrypted --> ignored!');
return false; // can no longer store something in the session, eg. because commit_session() was called
}
if (!isset($_SESSION[egw_session::EGW_APPSESSION_VAR][$app][$location]))
{
return false;
}
unset($_SESSION[egw_session::EGW_APPSESSION_VAR][$app][$location]);
return true;
}
/**
* Static varible to cache request wide
*
* @var array
*/
private static $request_cache = array();
/**
* Set some data in the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @param mixed $data
* @param int $expiration=0 expiration time is NOT used for REQUEST!
* @return boolean true if data could be stored, false otherwise
*/
static public function setRequest($app,$location,$data,$expiration=0)
{
self::$request_cache[$app][$location] = $data;
return true;
}
/**
* Get some data from the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @param callback $callback=null callback to get/create the value, if it's not cache
* @param array $callback_params=null array with parameters for the callback
* @param int $expiration=0 expiration time is NOT used for REQUEST!
* @return mixed NULL if data not found in cache (and no callback specified)
*/
static public function getRequest($app,$location,$callback=null,array $callback_params=null,$expiration=0)
{
if (!isset(self::$request_cache[$app][$location]) && !is_null($callback))
{
self::$request_cache[$app][$location] = call_user_func_array($callback,$callback_params);
}
return self::$request_cache[$app][$location];
}
/**
* Unset some data in the cache for the whole source tree (all instances)
*
* @param string $app application storing data
* @param string $location location name for data
* @return boolean true if data was set, false if not (like isset())
*/
static public function unsetRequest($app,$location)
{
if (!isset(self::$request_cache[$app][$location]))
{
return false;
}
unset(self::$request_cache[$app][$location]);
return $ret;
}
/**
* Get a caching provider for tree or instance level
*
* The returned provider already has an opened connection
*
* @param string $level egw_cache::(TREE|INSTANCE)
* @return egw_cache_provider
*/
static protected function get_provider($level)
{
static $providers = array();
if (!isset($providers[$level]))
{
$params = $GLOBALS['egw_info']['server']['cache_provider_'.strtolower($level)];
if (!isset($params) && $level == self::INSTANCE && isset(self::$default_provider))
{
$params = self::$default_provider;
}
if (!isset($params))
{
if ($level == self::TREE) // if no tree level provider use the instance level one
{
$providers[$level] = self::get_provider(self::INSTANCE);
}
else
{
$providers[$level] = false; // no provider specified
$reason = 'no provider specified';
}
}
elseif (!$params)
{
$providers[$level] = false; // cache for $level disabled
$reason = "cache for $level disabled";
}
else
{
if (!is_array($params)) $params = (array)$params;
$class = array_shift($params);
if (!class_exists($class))
{
$providers[$level] = false; // provider class not found
$reason = "provider $class not found";
}
else
{
try
{
$providers[$level] = new $class($params);
}
catch(Exception $e)
{
$providers[$level] = false; // eg. could not open connection to backend
$reason = "error instanciating provider $class: ".$e->getMessage();
}
}
}
if (!$providers[$level]) error_log(__METHOD__."($level) no provider found ($reason)!");
}
//error_log(__METHOD__."($level) = ".array2string($providers[$level]).', cache_provider='.array2string($GLOBALS['egw_info']['server']['cache_provider_'.strtolower($level)]));
return $providers[$level];
}
/**
* Get keys array from $level, $app and $location
*
* @param string $level egw_cache::(TREE|INSTANCE)
* @param string $app
* @param string $location
* @return array
*/
static protected function keys($level,$app,$location)
{
static $bases = array();
if (!isset($bases[$level]))
{
switch($level)
{
case self::TREE:
$bases[$level] = $level.'-'.str_replace(array(':','/','\\'),'-',EGW_SERVER_ROOT);
break;
case self::INSTANCE:
if(!isset($GLOBALS['egw_info']['server']['install_id']))
{
if (isset($GLOBALS['egw_setup']) && isset($GLOBALS['egw_setup']->db))
{
$GLOBALS['egw_info']['server']['install_id'] = $GLOBALS['egw_setup']->db->select(config::TABLE,'config_value',array(
'config_app' => 'phpgwapi',
'config_name' => 'install_id',
),__LINE__,__FILE__)->fetchColumn();
}
if (!$GLOBALS['egw_info']['server']['install_id'])
{
throw new Exception (__METHOD__."($level,$app,$location) server/install_id is NOT set!");
}
}
$bases[$level] = $level.'-'.$GLOBALS['egw_info']['server']['install_id'];
break;
}
}
return array($bases[$level],$app,$location);
}
/**
* Let everyone know the methods of this class should be used only statically
*
*/
function __construct()
{
throw new egw_exception_wrong_parameter("All methods of class ".__CLASS__." should be called static!");
}
}
/**
* Interface for a caching provider for tree and instance level
*
* The provider can eg. create subdirs under /tmp for each key
* to store data as a file or concat them with a separator to
* get a single string key to eg. store data in memcached
*/
interface egw_cache_provider
{
/**
* Constructor, eg. opens the connection to the backend
*
* @throws Exception if connection to backend could not be established
* @param array $params eg. array(host,port) or array(directory) depending on the provider
*/
function __construct(array $params);
/**
* Stores some data in the cache
*
* @param array $keys eg. array($level,$app,$location)
* @param mixed $data
* @param int $expiration=0
* @return boolean true on success, false on error
*/
function set(array $keys,$data,$expiration=0);
/**
* Get some data from the cache
*
* @param array $keys eg. array($level,$app,$location)
* @return mixed data stored or NULL if not found in cache
*/
function get(array $keys);
/**
* Delete some data from the cache
*
* @param array $keys eg. array($level,$app,$location)
* @return boolean true on success, false on error (eg. $key not set)
*/
function delete(array $keys);
}