/wp-content/plugins/w3-total-cache/lib/W3/ObjectCache.php

<?php



/**

 * W3 Object Cache object

 */

class W3_ObjectCache

{

    /**

     * Internal cache array

     * 

     * @var array

     */

    var $cache = array();

    

    /**

     * Array of global groups

     * 

     * @var array

     */

    var $global_groups = array();

    

    /**

     * List of non-persistent groups

     *

     * @var array

     */

    var $nonpersistent_groups = array();

    

    /**

     * Total count of calls

     *

     * @var integer

     */

    var $cache_total = 0;

    

    /**

     * Cache hits count

     * 

     * @var integer

     */

    var $cache_hits = 0;

    

    /**

     * Cache misses count

     *

     * @var integer

     */

    var $cache_misses = 0;

    

    /**

     * Store debug information of w3tc using

     *

     * @var array

     */

    var $debug_info = array();

    

    /**

     * Config

     *

     * @var W3_Config

     */

    var $_config = null;

    

    /**

     * Caching flag

     * 

     * @var boolean

     */

    var $_caching = false;

    

    /**

     * Cache reject reason

     * 

     * @var string

     */

    var $_cache_reject_reason = '';

    

    /**

     * Lifetime

     *

     * @var integer

     */

    var $_lifetime = null;

    

    /**

     * Debug flag

     * 

     * @var boolean

     */

    var $_debug = false;

    

    /**

     * PHP5 style constructor

     */

    function __construct()

    {

        require_once W3TC_LIB_W3_DIR . '/Config.php';

        

        $this->_config = & W3_Config::instance();

        $this->_lifetime = $this->_config->get_integer('objectcache.lifetime');

        $this->_debug = $this->_config->get_boolean('objectcache.debug');

        

        $this->global_groups = $this->_config->get_array('objectcache.groups.global');

        $this->nonpersistent_groups = $this->_config->get_array('objectcache.groups.nonpersistent');

        

        $this->_caching = $this->_can_cache();

        

        $GLOBALS['_wp_using_ext_object_cache'] = $this->_caching;

        

        if ($this->_can_ob()) {

            ob_start(array(

                &$this, 

                'ob_callback'

            ));

        }

    }

    

    /**

     * PHP4 style constructor

     */

    function W3_ObjectCache()

    {

        $this->__construct();

    }

    

    /**

     * Returns onject instance

     *

     * @return W3_ObjectCache

     */

    function &instance()

    {

        static $instances = array();

        

        if (!isset($instances[0])) {

            $class = __CLASS__;

            $instances[0] = & new $class();

        }

        

        return $instances[0];

    }

    

    /**

     * Get from the cache

     * 

     * @param string $id

     * @param string $group

     * @return mixed

     */

    function get($id, $group = 'default')

    {

        $key = $this->_get_cache_key($id, $group);

        

        $caching = true;

        $internal = true;

        $reason = '';

        

        if (isset($this->cache[$key])) {

            $value = $this->cache[$key];

        } else {

            $caching = $this->_can_cache2($id, $group, $reason);

            $internal = false;

            

            if ($caching) {

                $cache = & $this->_get_cache();

                $value = $cache->get($key);

            } else {

                $value = false;

            }

            

            $this->cache[$key] = $value;

        }

        

        if ($value === null) {

            $value = false;

        }

        

        $this->cache_total++;

        

        if ($value !== false) {

            $cached = true;

            $this->cache_hits++;

        } else {

            $cached = false;

            $this->cache_misses++;

        }

        

        /**

         * Add debug info

         */

        if ($this->_debug) {

            if (!$group) {

                $group = 'default';

            }

            

            $this->debug_info[] = array(

                'id' => $id, 

                'group' => $group, 

                'caching' => $caching, 

                'reason' => $reason, 

                'cached' => $cached, 

                'internal' => $internal

            );

        }

        

        return $value;

    }

    

    /**

     * Set to the cache

     * 

     * @param string $id

     * @param mixed $data

     * @param string $group

     * @param integer $expire

     * @return boolean

     */

    function set($id, $data, $group = 'default', $expire = 0)

    {

        $key = $this->_get_cache_key($id, $group);

        

        if (is_object($data)) {

            $data = wp_clone($data);

        }

        

        if (isset($this->cache[$key]) && $this->cache[$key] === $data) {

            return true;

        }

        

        $this->cache[$key] = $data;

        

        $reason = '';

        

        if ($this->_can_cache2($id, $group, $reason)) {

            $cache = & $this->_get_cache();

            

            return $cache->set($key, $data, ($expire ? $expire : $this->_lifetime));

        }

        

        return true;

    }

    

    /**

     * Delete from the cache

     * 

     * @param string $id

     * @param string $group

     * @return boolean

     */

    function delete($id, $group = 'default')

    {

        $key = $this->_get_cache_key($id, $group);

        

        unset($this->cache[$key]);

        

        $reason = '';

        

        if ($this->_can_cache2($id, $group, $reason)) {

            $cache = & $this->_get_cache();

            

            return $cache->delete($key);

        }

        

        return true;

    }

    

    /**

     * Add to the cache

     * 

     * @param string $id

     * @param mixed $data

     * @param string $group

     * @param integer $expire

     * @return boolean

     */

    function add($id, $data, $group = 'default', $expire = 0)

    {

        if ($this->get($id, $group) !== false) {

            return false;

        }

        

        return $this->set($id, $data, $group, $expire);

    }

    

    /**

     * Replace in the cache

     * 

     * @param string $id

     * @param mixed $data

     * @param string $group

     * @param integer $expire

     * @return boolean

     */

    function replace($id, $data, $group = 'default', $expire = 0)

    {

        if ($this->get($id, $group) === false) {

            return false;

        }

        

        return $this->set($id, $data, $group, $expire);

    }

    

    /**

     * Flush cache

     * 

     * @return boolean

     */

    function flush()

    {

        $this->cache = array();

        

        $cache = & $this->_get_cache();

        

        return $cache->flush();

    }

    

    /**

     * Add global groups

     * 

     * @param array $groups

     * @return void

     */

    function add_global_groups($groups)

    {

        if (!is_array($groups)) {

            $groups = (array) $groups;

        }

        

        $this->global_groups = array_merge($this->global_groups, $groups);

        $this->global_groups = array_unique($this->global_groups);

    }

    

    /**

     * Add non-persistent groups

     * 

     * @param array $groups

     * @return void

     */

    function add_nonpersistent_groups($groups)

    {

        if (!is_array($groups)) {

            $groups = (array) $groups;

        }

        

        $this->nonpersistent_groups = array_merge($this->nonpersistent_groups, $groups);

        $this->nonpersistent_groups = array_unique($this->nonpersistent_groups);

    }

    

    /**

     * Output buffering callback

     *

     * @param string $buffer

     * @return string

     */

    function ob_callback(&$buffer)

    {

        if ($buffer != '' && w3_is_xml($buffer)) {

            $buffer .= "\r\n\r\n" . $this->_get_debug_info();

        }

        

        return $buffer;

    }

    

    /**

     * Returns cache key

     * 

     * @param string $id

     * @param string $group

     * @return string

     */

    function _get_cache_key($id, $group = 'default')

    {

        if (!$group) {

            $group = 'default';

        }

        

        $host = w3_get_host();

        

        if (!in_array($group, $this->global_groups)) {

            $prefix = w3_get_blogname();

        } else {

            $prefix = '';

        }

        

        $key = sprintf('w3tc_%s_object_%s', md5($host), md5($prefix . $group . $id));

        

        /**

         * Allow to modify cache key by W3TC plugins

         */

        $key = w3tc_do_action('w3tc_objectcache_cache_key', $key);

        

        return $key;

    }

    

    /**

     * Returns cache object

     *

     * @return W3_Cache_Base

     */

    function &_get_cache()

    {

        static $cache = array();

        

        if (!isset($cache[0])) {

            $engine = $this->_config->get_string('objectcache.engine');

            

            switch ($engine) {

                case 'memcached':

                    $engineConfig = array(

                        'servers' => $this->_config->get_array('objectcache.memcached.servers'), 

                        'persistant' => $this->_config->get_boolean('objectcache.memcached.persistant')

                    );

                    break;

                

                case 'file':

                    $engineConfig = array(

                        'cache_dir' => W3TC_CACHE_FILE_OBJECTCACHE_DIR, 

                        'locking' => $this->_config->get_boolean('objectcache.file.locking')

                    );

                    break;

                

                default:

                    $engineConfig = array();

            }

            

            require_once W3TC_LIB_W3_DIR . '/Cache.php';

            $cache[0] = & W3_Cache::instance($engine, $engineConfig);

        }

        

        return $cache[0];

    }

    

    /**

     * Check if caching allowed on init

     * 

     * @return boolean

     */

    function _can_cache()

    {

        /**

         * Skip if disabled

         */

        if (!$this->_config->get_boolean('objectcache.enabled')) {

            $this->_cache_reject_reason = 'object caching is disabled';

            

            return false;

        }

        

        /**

         * Check for DONOTCACHCEOBJECT constant

         */

        if (defined('DONOTCACHCEOBJECT') && DONOTCACHCEOBJECT) {

            $this->_cache_reject_reason = 'DONOTCACHCEOBJECT constant is defined';

            

            return false;

        }

        

        /**

         * Skip if admin

         */

        if ($this->_config->get_boolean('objectcache.reject.admin') && defined('WP_ADMIN')) {

            $this->_cache_reject_reason = 'wp-admin';

            

            return false;

        }

        

        /**

         * Check request URI

         */

        if (!$this->_check_request_uri()) {

            $this->_cache_reject_reason = 'request URI is rejected';

            

            return false;

        }

        

        return true;

    }

    

    /**

     * Check if caching allowed runtime

     *

     * @param string $id

     * @param string $group

     * @return boolean

     */

    function _can_cache2($id, $group, &$cache_reject_reason)

    {

        /**

         * Skip if disabled

         */

        if (!$this->_caching) {

            $cache_reject_reason = $this->_cache_reject_reason;

            

            return false;

        }

        

        /**

         * Check for DONOTCACHCEOBJECT constant

         */

        if (defined('DONOTCACHCEOBJECT') && DONOTCACHCEOBJECT) {

            $cache_reject_reason = 'DONOTCACHCEOBJECT constant is defined';

            

            return false;

        }

        

        /**

         * Skip if key in non-persistent group

         */

        if (!$group) {

            $group = 'default';

        }

        

        if (in_array($group, $this->nonpersistent_groups)) {

            $cache_reject_reason = 'non-persistent group';

            

            return false;

        }

        

        return true;

    }

    

    /**

     * Check request URI

     *

     * @return boolean

     */

    function _check_request_uri()

    {

        $auto_reject_uri = array(

            'wp-login', 

            'wp-register'

        );

        

        foreach ($auto_reject_uri as $uri) {

            if (strstr($_SERVER['REQUEST_URI'], $uri) !== false) {

                return false;

            }

        }

        

        $reject_uri = $this->_config->get_array('objectcache.reject.uri');

        

        foreach ($reject_uri as $expr) {

            $expr = trim($expr);

            if ($expr != '' && preg_match('~' . $expr . '~i', $_SERVER['REQUEST_URI'])) {

                return false;

            }

        }

        

        return true;

    }

    

    /**

     * Check if we can start OB

     * 

     * @return boolean

     */

    function _can_ob()

    {

        /**

         * Object cache should be enabled

         */

        if (!$this->_config->get_boolean('objectcache.enabled')) {

            return false;

        }

        

        /**

         * Debug should be enabled

         */

        if (!$this->_config->get_boolean('objectcache.debug')) {

            return false;

        }

        

        /**

         * Skip if admin

         */

        if (defined('WP_ADMIN')) {

            return false;

        }

        

        /**

         * Skip if doint AJAX

         */

        if (defined('DOING_AJAX')) {

            return false;

        }

        

        /**

         * Skip if doing cron

         */

        if (defined('DOING_CRON')) {

            return false;

        }

        

        /**

         * Skip if APP request

         */

        if (defined('APP_REQUEST')) {

            return false;

        }

        

        /**

         * Skip if XMLRPC request

         */

        if (defined('XMLRPC_REQUEST')) {

            return false;

        }

        

        /**

         * Check for WPMU's and WP's 3.0 short init

         */

        if (defined('SHORTINIT') && SHORTINIT) {

            return false;

        }

        

        return true;

    }

    

    /**

     * Returns debug info

     * 

     * @return string

     */

    function _get_debug_info()

    {

        $debug_info = "<!-- W3 Total Cache: Object Cache debug info:\r\n";

        $debug_info .= sprintf("%s%s\r\n", str_pad('Engine: ', 20), w3_get_engine_name($this->_config->get_string('objectcache.engine')));

        $debug_info .= sprintf("%s%d\r\n", str_pad('Total calls: ', 20), $this->cache_total);

        $debug_info .= sprintf("%s%d\r\n", str_pad('Cache hits: ', 20), $this->cache_hits);

        $debug_info .= sprintf("%s%d\r\n", str_pad('Cache misses: ', 20), $this->cache_misses);

        

        $debug_info .= "W3TC Object Cache info:\r\n";

        $debug_info .= sprintf("%s | %s | %s | %s | %s\r\n", str_pad('#', 5, ' ', STR_PAD_LEFT), str_pad('Caching (Reject reason)', 30, ' ', STR_PAD_BOTH), str_pad('Status', 15, ' ', STR_PAD_BOTH), str_pad('Source', 15, ' ', STR_PAD_BOTH), 'ID:Group');

        

        foreach ($this->debug_info as $index => $debug) {

            $debug_info .= sprintf("%s | %s | %s | %s | %s\r\n", str_pad($index + 1, 5, ' ', STR_PAD_LEFT), str_pad(($debug['caching'] ? 'enabled' : sprintf('disabled (%s)', $debug['reason'])), 30, ' ', STR_PAD_BOTH), str_pad(($debug['cached'] ? 'cached' : 'not cached'), 15, ' ', STR_PAD_BOTH), str_pad(($debug['internal'] ? 'internal' : 'persistent'), 15, ' ', STR_PAD_BOTH), sprintf('%s:%s', $debug['id'], $debug['group']));

        }

        

        $debug_info .= '-->';

        

        return $debug_info;

    }

}