*
* TODO: Simple usage example goes here.
*
+* WARNING: No File/DB-Table-Row locking is implemented yet,
+* it's possible, that you get corrupted data-entries under
+* bad circumstances (especially with the file container)
+*
* @author Ulf Wendel <ulf.wendel@phpdoc.de>
* @version $Id$
* @package Cache
-* @access public
+* @access public
*/
-class Cache {
+class Cache extends PEAR {
/**
* Disables the caching.
/**
* Garbage collection: probability in seconds
*
- * If set to a value above 0 a garbage collection will
- * flush all cache entries older than the specified number
+ * If set to a value above 0 a garbage collection will
+ * flush all cache entries older than the specified number
* of seconds.
*
* @var integer
/**
* Storage container object.
- *
+ *
* @var object Cache_Container
- */
+ */
var $container;
//
// public methods
//
- /**
+ /**
*
* @param string Name of storage container class
* @param array Array with storage class dependend config options
*/
function Cache($storage_driver, $storage_options = "")
{
+ $this->PEAR();
$storage_driver = strtolower($storage_driver);
$storage_class = 'Cache_Container_' . $storage_driver;
$storage_classfile = 'Cache/Container/' . $storage_driver . '.php';
include_once $storage_classfile;
$this->container = new $storage_class($storage_options);
+ }
+
+ //deconstructor
+ function _Cache()
+ {
$this->garbageCollection();
-
}
/**
* Returns the requested dataset it if exists and is not expired
- *
+ *
* @param string dataset ID
* @param string cache group
* @return mixed cached data or NULL on failure
function get($id, $group = "default") {
if ($this->no_cache)
return "";
-
+
if ($this->isCached($id, $group) && !$this->isExpired($id, $group))
return $this->load($id, $group);
-
- return NULL;
+
+ return NULL;
} // end func get
/**
* Stores the given data in the cache.
- *
+ *
* @param string dataset ID used as cache identifier
* @param mixed data to cache
* @param integer lifetime of the cached data in seconds - 0 for endless
function save($id, $data, $expires = 0, $group = "default") {
if ($this->no_cache)
return true;
-
+
return $this->container->save($id, $data, $expires, $group, "");
} // end func save
/**
* Stores a dataset without additional userdefined data.
- *
+ *
* @param string dataset ID
* @param mixed data to store
* @param string additional userdefined data
/**
* Loads the given ID from the cache.
- *
+ *
* @param string dataset ID
* @param string cache group
- * @return mixed cached data or NULL on failure
+ * @return mixed cached data or NULL on failure
* @access public
*/
function load($id, $group = "default") {
if ($this->no_cache)
return "";
-
+
return $this->container->load($id, $group);
} // end func load
function getUserdata($id, $group = "default") {
if ($this->no_cache)
return "";
-
+
return $this->container->getUserdata($id, $group);
} // end func getUserdata
/**
* Removes the specified dataset from the cache.
- *
+ *
* @param string dataset ID
* @param string cache group
* @return boolean
function delete($id, $group = "default") {
if ($this->no_cache)
return true;
-
+
return $this->container->delete($id, $group);
} // end func delete
/**
* Flushes the cache - removes all data from it
- *
+ *
* @param string cache group, if empty all groups will be flashed
* @return integer number of removed datasets
*/
function flush($group = "") {
if ($this->no_cache)
return true;
-
+
return $this->container->flush($group);
} // end func flush
/**
* Checks if a dataset exists.
- *
+ *
* Note: this does not say that the cached data is not expired!
- *
+ *
* @param string dataset ID
* @param string cache group
* @return boolean
function isCached($id, $group = "default") {
if ($this->no_cache)
return false;
-
+
return $this->container->isCached($id, $group);
} // end func isCached
/**
* Checks if a dataset is expired
- *
+ *
* @param string dataset ID
* @param string cache group
* @param integer maximum age for the cached data in seconds - 0 for endless
* If the cached data is older but the given lifetime it will
- * be removed from the cache. You don't have to provide this
- * argument if you call isExpired(). Every dataset knows
- * it's expire date and will be removed automatically. Use
+ * be removed from the cache. You don't have to provide this
+ * argument if you call isExpired(). Every dataset knows
+ * it's expire date and will be removed automatically. Use
* this only if you know what you're doing...
* @return boolean
* @access public
function isExpired($id, $group = "default", $max_age = 0) {
if ($this->no_cache)
return true;
-
+
return $this->container->isExpired($id, $group, $max_age);
} // end func isExpired
/**
* Generates a "unique" ID for the given value
- *
+ *
* This is a quick but dirty hack to get a "unique" ID for a any kind of variable.
* ID clashes might occur from time to time although they are extreme unlikely!
*
/**
* Calls the garbage collector of the storage object with a certain probability
- *
+ *
* @param boolean Force a garbage collection run?
* @see $gc_probability, $gc_time
*/
function garbageCollection($force = false) {
static $last_run = 0;
-
+
if ($this->no_cache)
return;
srand((double) microtime() * 1000000);
-
+
// time and probability based
if (($force) || ($last_run && $last_run < time() + $this->gc_time) || (rand(1, 100) < $this->gc_probability)) {
$this->container->garbageCollection();
$last_run = time();
}
} // end func garbageCollection
-
-} // end class cache
+
+} // end class cache
?>
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