Molajo Cache Services

cacheservice.php

<?php
/**
 * @package    Molajo
 * @copyright  2012 Amy Stephen. All rights reserved.
 * @license    GNU GPL v 2, or later and MIT, see License folder
 */
namespace Molajo\Service\Services\Cache;

use Molajo\Service\Services;

defined('MOLAJO') or die;

/**
 * Cache
 *
 * @package     Molajo
 * @subpackage  Services
 * @since       1.0
 */
Class CacheService
{
	/**
	 * Static instance
	 *
	 * @var    object
	 * @since  1.0
	 */
	protected static $instance;

	/**
	 * Cache
	 *
	 * @var    string
	 * @since  1.0
	 */
	protected $cache = false;

	/**
	 * Cache Path
	 *
	 * @var    string
	 * @since  1.0
	 */
	protected $cache_path = '';

	/**
	 * Cache Handler
	 *
	 * @var    string
	 * @since  1.0
	 */
	protected $cache_handler = '';

	/**
	 * Cache Time
	 *
	 * @var    Integer
	 * @since  1.0
	 */
	protected $cache_time = 900;

	/**
	 * getInstance
	 *
	 * @static
	 * @return bool|object
	 * @since  1.0
	 */
	public static function getInstance()
	{
		if (empty(self::$instance)) {
			self::$instance = new CacheService();
		}

		return self::$instance;
	}

	/**
	 * Class constructor
	 *
	 * @since  1.0
	 */
	public function __construct()
	{
		$this->cache = false;
		return $this;
	}

	/**
	 * Start Cache - if so configured
	 *
	 * @since  1.0
	 */
	public function startCache()
	{
		if (Services::Registry()->get('Configuration', 'cache') == 0) {
			$this->cache = false;
			return false;
		}

		$this->cache = true;

		if (Services::Registry()->get('Configuration', 'cache_handler', 'file') == 'file') {
			$this->cache_path = SITE_BASE_PATH . '/'
				. Services::Registry()->get('Configuration', 'cache_path');
		} else {
			return false;
		}

		$this->cache_time = (int)Services::Registry()->get('Configuration', 'cache_time', 900);
		if ($this->cache_time == 0) {
			$this->cache_time = 900;
		}

		Services::Registry()->createRegistry('Cachekeys');
		$this->loadCacheKeys();

		return $this;
	}

	/**
	 * Determine if cache exists for this object
	 *
	 * @param   string  $key  md5 name uniquely identifying content
	 *
	 * @return  boolean  The option value.
	 * @since   1.0
	 */
	public function exists($key)
	{
		if ($this->cache == true) {
			$exists = Services::Registry()->exists('Cachekeys', $key);
			if ($exists == false) {
				return false;
			}

			return $this->checkExpired($key);
		}
	}

	/**
	 * Create a cache entry
	 *
	 * @param   string  $key    md5 name uniquely identifying content
	 * @param   mixed   $value  Data to be serialized and then saved as cache
	 *
	 * @return  object
	 * @since   1.0
	 */
	public function set($key, $value)
	{
		file_put_contents($this->cache_path . '/' . $key, serialize($value));

		Services::Registry()->set('Cachekeys', $key);

		return $this;
	}

	/**
	 * Return cached value
	 *
	 * @param   string  $key  md5 name uniquely identifying content
	 *
	 * @return  mixed   unserialized cache for this key
	 * @since   1.0
	 */
	public function get($key)
	{
		if ($key == 'on') {
			return $this->cache;
		}

		if ($this->cache == true) {
			return unserialize(file_get_contents($this->cache_path . '/' . $key));
		}

		return false;
	}


	/**
	 * Load cache keys
	 *
	 * @return  object
	 * @since   1.0
	 */
	public function loadCacheKeys()
	{
		if (is_dir($this->cache_path)) {
		} else {
			return false;
		}

		$files = Services::Filesystem()->folderFiles($this->cache_path);
		if (count($files) > 0
			|| $files === false
		) {
			return $this;
		}

		foreach ($files as $file) {
			$results = Services::Registry()->delete('Cachekeys', $file);
			if ($results === false) {
			} else {
				Services::Registry()->set('Cachekeys', $file);
			}
		}

		return $this;
	}

	/**
	 * Remove cache for specified $key value
	 *
	 * @param   string  $key  md5 name uniquely identifying content
	 *
	 * @return  object
	 * @since   1.0
	 */
	public function checkExpired($key)
	{

		if (file_exists($this->cache_path . '/' . $key)) {
		} else {
			$this->delete($key);
			return false;
		}

		if (filemtime($this->cache_path . '/' . $key) < (time() - $this->cache_time)) {
			return true;
		}

		$this->delete($key);
	}

	/**
	 * Remove cache for specified $key value
	 *
	 * @param   string  $key  md5 name uniquely identifying content
	 *
	 * @return  object
	 * @since   1.0
	 */
	public function delete($key)
	{
		if (file_exists($this->cache_path . '/' . $key)) {
			unlink($this->cache_path . '/' . $key);
		}

		Services::Registry()->delete('Cachekeys', $key);

		return $this;
	}
}

The start of Molajo cache, currently only supports file cache. Will abstract out adapters very soon.

Currently, it is only used in support of queries, need to add in all of the other layers.

The query itself is used to make the MD5 hash which serves as the title. Would like to see if cache can be used for logged in users, as well as visitors. Since Molajo's ACL includes the ACL settings in the query, it should be possible to do so.

Am understanding why the Joomla Plugin Query grabbed all plugins, rather than the plugin needed. Might adapt Molajo queries to be of two parts -- the initial "broad" pull, and then a selective lookup on a registry internal table, so as to help keep those query counts low.

Without cache, Molajo has around 120 queries for the Resource Grid page. If all Views were selected once, that number would cut down to considerably less.