Atom Cache

cache.php

<?php

/**
 * Core Atom library namespace. This namespace contains all of the fundamental
 * components of Atom, plus additional utilities that are provided by default.
 * Some of these default components have sub namespaces if they provide child
 * objects.
 *
 * @pacakge    Atom
 * @subpackage Library
 */
namespace Atom;

// Aliasing rules
use \Atom\Config;
use \Atom\Design\Multiton;

/**
 * @package    Atom
 * @subpackage Library
 */
class Cache implements Multiton {

	/**
	 * Holds a \Atom\Storage instance, to save memory
	 *
	 * @var   object
	 */
	private static $storage;

	private $items = array();

	private $cache;

	/**
	 * Class Constructor
	 *
	 * @param     string     Cache driver to use
	 * @param     boolean    Whether to use the persistent cache file extension
	 * @return    void
	 */
	public function __construct($driver)
	{
		$this->cache = $driver;
	}

	public static function init()
	{
		static::$storage = (static::$storage) ?: new \Atom\Storage();
	}

	/**
	 * Get the saved data from cache.
	 *
	 */
	public function read($key)
	{
		// Read from cache...

		$expired = $expires !== 0 and $expires < time();

		return $data;
	}

	/**
	 * Save data to cache
	 *
	 * Sets meta=data needed for cache control, and saves it along with
	 * the data.
	 *
	 * @param     mixed       Cache data
	 * @param     integer     Expiry length in seconds
	 * @return    void
	 */
	public function write($key, $data, $expiry = null, $extras = array())
	{
		$expiry = ($expiry) ?: Config::get('cache.expiry');

		$cache = array(
			'data' => $data,
			'created' => time(),
			'expires' => $expiry === 0 ? 0 : time() + $expiry,
		);

		$cache = array_merge($cache, $extras);
	}

	/**
	 * Remove data and delete cache entity
	 *
	 * @param     boolean     Force cache to expire
	 * @return    boolean
	 *
	 * @throws    \Exception  If cache cannot be deleted
	 */
	public function expire($key, $force = false)
	{
		if($force or $this->expired())
		{
			$this->data = array();
			$this->meta = array();
			
			throw new \RuntimeException('Unable to delete cache with key ['.$this->key.']');
		}
		return false;
	}
}

/* End of file cache.php */