PHPCache.class.php

<?php

/**
 * PHPCache - a PHP caching class
 *
 * @author      Christian Klisch <info@christian-klisch.de>
 * @copyright   2014 Christian Klisch
 * @link        https://github.com/christianklisch/phpcache
 * @license     https://github.com/christianklisch/phpcache/LICENSE
 * @version     0.1.2
 * @package     PHPCache
 *
 * APACHE LICENSE 
 * 
 * Copyright (c) 2014 Christian Klisch    
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *   
 * http://www.apache.org/licenses/LICENSE-2.0
 *   
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * PHPCache
 * @package PHPCache
 * @author  Christian Klisch
 * @since   0.1.0
 */
class PHPCache {

    /**
     * @var array
     */
    protected $settings;

    /**
     * @var array
     */
    protected $primarykeys;

    /*     * ******************************************************************************
     * Instantiation and Configuration
     * ***************************************************************************** */

    /**
     * Constructor
     * @param  array $settings Associative array of caching settings
     */
    public function __construct($settings = array()) {
        // Setup caching
        $this->settings = array_merge(static::getDefaultSettings(), $settings);
    }

    /**
     * Get default application settings
     * @return array
     */
    public static function getDefaultSettings() {
        return array(
            // directory
            'cacheDir' => 'cache/phpcache',
            // caching time in seconds
            'cacheTime' => '360',
            // Debugging
            'debug' => false
        );
    }

    /**
     * Read and Write config
     * @param  $name setting name     
     * @return string     
     */
    public function getConfig($name) {
        return isset($this->settings[$name]) ? $this->settings[$name] : null;
    }

    /**
     * Setting get-functions for primary keys of classes
     * @param  array $primkeys Associative array of class primary-key-function
     */
    public function setPrimaryKeys($primkeys = array()) {
        $this->primarykeys = $primkeys;
    }

    /*     * ******************************************************************************
     * Logic functions
     * ***************************************************************************** */

    /**
     * get cached value in time or return value
     * @param $value value or object to cache     
     * @param $id key for cache
     * @return object     
     */
    public function cacheVal($value, $id = null) {
        if ($id == null) {
            if (is_object($value))
                $id = $this->getIDfromOjb($value);

            if ($id == null && $this->getConfig('debug')) {
                echo "no caching key";
                return $value;
            }
        }

        $cachefile = $this->getConfig('cacheDir') . '/' . utf8_decode($id);
        $cachetime = $this->getConfig('cacheTime');

        if (file_exists($cachefile) && time() - $cachetime < fileatime($cachefile)) {
            $ser = file_get_contents($cachefile);
            $val = bzdecompress(unserialize($ser));
            return $val;
        } else {
            $ser = bzcompress(serialize($value));
            file_put_contents($cachefile, $ser);
            return $value;
        }

        if ($this->getConfig('debug'))
            echo "no caching";
    }

    /**
     * cache function result and return it
     * @param $function closure to cache 
     * @return object     
     */
    public function cacheFun($function) {
        if ($this->getConfig('debug') && !is_callable($function))
            echo "no valid function";

        $r = new ReflectionFunction($function);
        $id = null;

        foreach ($r->getStaticVariables() as $key => $var) {
            if ($key == 'key')
                $id = $var;
        }

        if (is_object($id))
            $id = $this->getIDfromOjb($id);

        if ($id == null && $this->getConfig('debug')) {
            echo "no caching key";
            return $function();
        }

        $cachefile = $this->getConfig('cacheDir') . '/' . utf8_decode($id);
        $cachetime = $this->getConfig('cacheTime');

        if (file_exists($cachefile) && time() - $cachetime < fileatime($cachefile)) {
            $ser = file_get_contents($cachefile);
            $val = bzdecompress(unserialize($ser));
            return $val;
        } else {
            $value = $function();
            $ser = serialize(bzcompress($value));
            file_put_contents($cachefile, $ser);
            return $value;
        }

        if ($this->getConfig('debug'))
            echo "no caching";
    }

    /**
     * check, if key or object in first parameter is cached. Returns true, if cached
     * @param $id key of cached object or value     
     * @return bool
     */
    public function isCached($id) {
        if ($id != null) {
            $id = $this->getIDfromOjb($id);
        }

        if ($id == null)
            return false;

        $cachefile = $this->getConfig('cacheDir') . '/' . utf8_decode($id);
        $cachetime = $this->getConfig('cacheTime');

        if (file_exists($cachefile) && time() - $cachetime < fileatime($cachefile)) {
            return true;
        }

        return false;
    }

    /**
     * get key from object $value
     * @param $value object getting key from
     * @return key     
     */
    private function getIDfromOjb($value) {
        $id = null;
        if ($this->primarykeys) {
            foreach ($this->primarykeys as $key => $function) {
                if (is_subclass_of($value, $key) || is_a($value, $key)) {
                    $id = $value->$function();
                    break;
                }
            }
        }
        return $id;
    }

    /**
     * delete all cached files 
     */
    public function clearCache() {
        $files = glob($this->getConfig('cacheDir') . '/*', GLOB_MARK);
        foreach ($files as $file) {
            unlink($file);
        }
    }
              
    /**        
     * delete old cached files 
     */
    public function gc() {
        $files = glob($this->getConfig('cacheDir') . '/*', GLOB_MARK);
        $cachetime = $this->getConfig('cacheTime');
        foreach ($files as $file) {
            if(time() - $cachetime > fileatime($file))
                unlink($file);
        }
    }    

}

?>