Moja implementacja "keszu" Opcje

[q.michal]

Witam,

Chcialbym dzis pdozielic sie swoim kolejnym wynalazkiem - obsluga keszu. Jest to co prawda dopiero zalazek tego co chce zrobic, albowiem brakuje metod odpowiedzialnych za obsluge danych, niemniej sposob 'komunikacji' ze sterownikiem widac na przykladzie metody Cache::dumpCache(); Docelowo zamierzam napisac takze wiecej sterownikow, zapewniajac dostep do: APC, eAccelerator, Dummy, File, MemCache, SQLite, WinCache, XCache. Zastanawiam sie takze nad mozliwoscia przechowywania keszu w cookies.

Jednoczesnie prosze o ocene oraz komentarze - czyli ogolnie mowiac code review (IMG:style_emoticons/default/wink.gif)
Jestem otwarty na wszelkie sugestie i uwagi poparte jakimkolwiek argumentem.

Pozdrawiam serdecznie.

[PHP] pobierz, plaintext 
abstract class CacheAbstract {
 
	/**
	 * Disables object cloning
	 *
	 * @return	void		does not return any value
	 */
	protected function __clone() {
		throw new Exception('Cloning Cache objects is not allowed!');
	}
 
	/**
	 * Class constructor
	 *
	 * @return	void		does not return any value
	 */
	protected function __construct() {
	}
 
} /* class */
 
 
interface CacheDriver {
 
	/**
	 * Adds an object to the cache
	 *
	 * @param	string		stores the variable using this name, should be a cache-unique name
	 * @param	mixed		the variable to store in cache
	 * @param	integer		time-to-live of cached data
	 * @return	boolean		TRUE on success, FALSE otherwise
	 */
	public function addValue($key, $var, $ttl = 300);
 
	/**
	 * Returns a dump of all files and user variables from the cache
	 *
	 * @return	string		dump of the user variables, or NULL if an unknown error encountered
	 */
	public function dumpCache();
 
	/**
	 * Flushes (clears) the user and system cache
	 *
	 * @return	void		does not return any value
	 */
	public function flushCache();
 
	/**
	 * Provides a statistics and meta-data of caching subsystem
	 *
	 * @return	array		array containing cache statistics
	 */
	public function getStatistics();
 
	/**
	 * Fetches a stored variable from the cache
	 *
	 * @param	string		key name used to store the value
	 * @return	mixed		stored variable on success, FALSE otherwise
	 */
	public function getValue($key);
 
	/**
	 * Checks if container contains an item stored under this key name
	 *
	 * @param	string		key name used to store the value
	 * @return	boolean		TRUE if the key exists, FALSE otherwise
	 */
	public function isCached($key);
 
	/**
	 * Checks whether the chosen driver is supported by PHP installation
	 *
	 * @return	boolean		TRUE if driver can be used, FALSE otherwise
	 */
	public function isSupported();
 
	/**
	 * Removes a stored variable from the cache
	 * @param	string		key name used to store the value
	 * @return	boolean		TRUE on success, FALSE otherwise
	 */
	public function removeValue($key);
 
} /* class */
 
 
final class CacheDriverApc extends CacheAbstract implements CacheDriver {
 
	/**
	 * Adds an object to the cache
	 *
	 * @param	string		stores the variable using this name, should be a cache-unique name
	 * @param	mixed		the variable to store in cache
	 * @param	integer		time-to-live of cached data
	 * @return	boolean		TRUE on success, FALSE otherwise
	 */
	public function addValue($key, $var, $ttl = 300) {
		return apc_store($key, $var, $ttl);
	}
 
	/**
	 * Returns a dump of all files and user variables from the cache
	 *
	 * @return	string		dump of the user variables, or NULL if an unknown error encountered
	 */
	public function dumpCache() {
		return apc_bin_dump();
	}
 
	/**
	 * Flushes (clears) the user and system cache
	 *
	 * @return	void		does not return any value
	 */
	public function flushCache() {
		apc_clear_cache();
		apc_clear_cache('user');
	}
 
	/**
	 * Provides a statistics and meta-data of caching subsystem
	 *
	 * @return	array		array containing cache statistics
	 */
	public function getStatistics() {
		return array('data' => apc_cache_info('user'), 'info' => '', 'size' => '');
	}
 
	/**
	 * Fetches a stored variable from the cache
	 *
	 * @param	string		key name used to store the value
	 * @return	mixed		stored variable on success, FALSE otherwise
	 */
	public function getValue($key) {
		$var = apc_fetch($key, $result);
		if(!$result) {
			return false;
		}
		return $var;
	}
 
	/**
	 * Checks if container contains an item stored under this key name
	 *
	 * @param	string		key name used to store the value
	 * @return	boolean		TRUE if the key exists, FALSE otherwise
	 */
	public function isCached($key) {
		return (bool) apc_exists($key);
	}
 
	/**
	 * Checks whether the chosen driver is supported by PHP installation
	 *
	 * @return	boolean		TRUE if driver can be used, FALSE otherwise
	 */
	public function isSupported() {
		if(!extension_loaded('apc') || !ini_get('apc.enabled')) {
			return false;
		}
		return true;
	}
 
	/**
	 * Removes a stored variable from the cache
	 * @param	string		key name used to store the value
	 * @return	boolean		TRUE on success, FALSE otherwise
	 */
	public function removeValue($key) {
		return apc_delete($key);
	}
 
} /* class */
 
 
final class Cache extends CacheAbstract {
	private $driver;
	private $storage;
 
	/**
	 * Class constructor.
	 *
	 * @param	string		specifies primary cache driver
	 * @param	string		specifies secondary (failover) cache driver
	 * @return	object		the Cache object
	 */
	protected function __construct($driver, $failover) {
		if(!$this->loadDriver($driver)) {
			if(!$this->loadDriver($failover)) {
				$this->loadDriver('dummy');
			}
		}
	}
 
	/**
	 * Returns a dump of all files and user variables from the cache
	 *
	 * @return	string		dump of the user variables, or NULL if an unknown error encountered
	 */
	public function dumpCache() {
		return $this->storage->dumpCache();
	}
 
	/**
	 * Returns a name of currently used cache storage driver
	 *
	 * @return	string		name of used storage driver
	 */
	public function getDriver() {
		return $this->driver;
	}
 
	/**
	 * Returns the global Cache object, creating it only if it does not exist already
	 *
	 * @param	string		specifies primary cache driver
	 * @param	string		specifies secondary (failover) cache driver
	 * @return	object		the Cache object
	 */
	public static function getInstance($driver = 'file', $failover = 'dummy') {
		static $instance;
		if(!isset($instance)) {
			$instance = new Cache($driver, $failover);
		}
		return $instance;
	}
 
	/**
	 * Returns a list of available cache storage drivers
	 *
	 * @return	array		an array containing a list of available cache drivers
	 */
	public static function getStorageList() {
		$list = array();
		$directory = System::getSystemDir() . '/cache/driver';
		$dh = opendir($directory);
		while(($filename = readdir($dh)) !== false) {
			$driver = substr($filename, 0, strrpos($filename, '.'));
			if($driver != '' && $driver != '.') {
				$list[] = $driver;
			}
		}
		return $list;
	}
 
	/**
	 * Loads the specified cache driver
	 *
	 * @param	string		cache driver to load
	 * @return	boolean		TRUE on success, FALSE otherwise
	 */
	private function loadDriver($driver) {
		if(in_array($driver, $this->getStorageList())) {
			$class = 'CacheDriver' . ucfirst($driver);
			$this->storage = new $class();
			if($this->storage->isSupported()) {
				$this->driver = $driver;
				return true;
			}
		}
		return false;
	}
 
} /* class */
[PHP] pobierz, plaintext 

[daro0]

To rand(0,99) jest chyba niezbyt dokładne. Można jeszcze użyć mt_rand, natomiast jakie jest prawdopodobieństwo że się trafi kilka razy pod rząd ta sama liczba? Tu zakładam że generator jest dość dobry a nie jakiś pseudo generator. Poza tym na ile jest prawdopodobne że się w katalogu cache utworzy ileś tam milionów plików a jeżeli nawet to ile one zajmują?

Weźmy np. jakieś API i pobieranie kursów walut jako JSON. Pobieranie ostatnich notowań kursów walut, oczywiście bez sensu to wywoływać za każdym razem, zwłaszcza że tu notowania są co dzień więc cache można sobie ustawić nawet na 24h. Nawet jak ktoś zechce szukać z różnymi opcjami to ile tu się tych plików utworzy? Jakiś użytkownik poczeka sobie może z 2 sekundy, reszta użytkowników będzie miała dane z cache i tu będzie ułamek sekundy, więc w czym tu jest problem?

Ten post edytował daro0 28.02.2016, 07:39:46