<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Cache

 * @subpackage Zend_Cache_Backend

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Apc.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/**

 * @see Zend_Cache_Backend_Interface

 */

require_once 'Zend/Cache/Backend/ExtendedInterface.php';

/**

 * @see Zend_Cache_Backend

 */

require_once 'Zend/Cache/Backend.php';

/**

 * @package    Zend_Cache

 * @subpackage Zend_Cache_Backend

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Cache_Backend_Apc extends Zend_Cache_Backend implements Zend_Cache_Backend_ExtendedInterface

{

    /**

     * Log message

     */

    const TAGS_UNSUPPORTED_BY_CLEAN_OF_APC_BACKEND = 'Zend_Cache_Backend_Apc::clean() : tags are unsupported by the Apc backend';

    const TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND =  'Zend_Cache_Backend_Apc::save() : tags are unsupported by the Apc backend';

    /**

     * Constructor

     *

     * @param  array $options associative array of options

     * @throws Zend_Cache_Exception

     * @return void

     */

    public function __construct(array $options = array())

    {

        if (!extension_loaded('apc')) {

            Zend_Cache::throwException('The apc extension must be loaded for using this backend !');

        }

        parent::__construct($options);

    }

    /**

     * Test if a cache is available for the given id and (if yes) return it (false else)

     *

     * WARNING $doNotTestCacheValidity=true is unsupported by the Apc backend

     *

     * @param  string  $id                     cache id

     * @param  boolean $doNotTestCacheValidity if set to true, the cache validity won't be tested

     * @return string cached datas (or false)

     */

    public function load($id, $doNotTestCacheValidity = false)

    {

        $tmp = apc_fetch($id);

        if (is_array($tmp)) {

            return $tmp[0];

        }

        return false;

    }

    /**

     * Test if a cache is available or not (for the given id)

     *

     * @param  string $id cache id

     * @return mixed false (a cache is not available) or "last modified" timestamp (int) of the available cache record

     */

    public function test($id)

    {

        $tmp = apc_fetch($id);

        if (is_array($tmp)) {

            return $tmp[1];

        }

        return false;

    }

    /**

     * Save some string datas into a cache record

     *

     * Note : $data is always "string" (serialization is done by the

     * core not by the backend)

     *

     * @param string $data datas to cache

     * @param string $id cache id

     * @param array $tags array of strings, the cache record will be tagged by each string entry

     * @param int $specificLifetime if != false, set a specific lifetime for this cache record (null => infinite lifetime)

     * @return boolean true if no problem

     */

    public function save($data, $id, $tags = array(), $specificLifetime = false)

    {

        $lifetime = $this->getLifetime($specificLifetime);

        $result = apc_store($id, array($data, time(), $lifetime), $lifetime);

        if (count($tags) > 0) {

            $this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);

        }

        return $result;

    }

    /**

     * Remove a cache record

     *

     * @param  string $id cache id

     * @return boolean true if no problem

     */

    public function remove($id)

    {

        return apc_delete($id);

    }

    /**

     * Clean some cache records

     *

     * Available modes are :

     * 'all' (default)  => remove all cache entries ($tags is not used)

     * 'old'            => unsupported

     * 'matchingTag'    => unsupported

     * 'notMatchingTag' => unsupported

     * 'matchingAnyTag' => unsupported

     *

     * @param  string $mode clean mode

     * @param  array  $tags array of tags

     * @throws Zend_Cache_Exception

     * @return boolean true if no problem

     */

    public function clean($mode = Zend_Cache::CLEANING_MODE_ALL, $tags = array())

    {

        switch ($mode) {

            case Zend_Cache::CLEANING_MODE_ALL:

                return apc_clear_cache('user');

                break;

            case Zend_Cache::CLEANING_MODE_OLD:

                $this->_log("Zend_Cache_Backend_Apc::clean() : CLEANING_MODE_OLD is unsupported by the Apc backend");

                break;

            case Zend_Cache::CLEANING_MODE_MATCHING_TAG:

            case Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG:

            case Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG:

                $this->_log(self::TAGS_UNSUPPORTED_BY_CLEAN_OF_APC_BACKEND);

                break;

            default:

                Zend_Cache::throwException('Invalid mode for clean() method');

                break;

        }

    }

    /**

     * Return true if the automatic cleaning is available for the backend

     *

     * DEPRECATED : use getCapabilities() instead

     *

     * @deprecated

     * @return boolean

     */

    public function isAutomaticCleaningAvailable()

    {

        return false;

    }

    /**

     * Return the filling percentage of the backend storage

     *

     * @throws Zend_Cache_Exception

     * @return int integer between 0 and 100

     */

    public function getFillingPercentage()

    {

        $mem = apc_sma_info(true);

        $memSize    = $mem['num_seg'] * $mem['seg_size'];

        $memAvailable= $mem['avail_mem'];

        $memUsed = $memSize - $memAvailable;

        if ($memSize == 0) {

            Zend_Cache::throwException('can\'t get apc memory size');

        }

        if ($memUsed > $memSize) {

            return 100;

        }

        return ((int) (100. * ($memUsed / $memSize)));

    }

    /**

     * Return an array of stored tags

     *

     * @return array array of stored tags (string)

     */

    public function getTags()

    {

        $this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);

        return array();

    }

    /**

     * Return an array of stored cache ids which match given tags

     *

     * In case of multiple tags, a logical AND is made between tags

     *

     * @param array $tags array of tags

     * @return array array of matching cache ids (string)

     */

    public function getIdsMatchingTags($tags = array())

    {

        $this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);

        return array();

    }

    /**

     * Return an array of stored cache ids which don't match given tags

     *

     * In case of multiple tags, a logical OR is made between tags

     *

     * @param array $tags array of tags

     * @return array array of not matching cache ids (string)

     */

    public function getIdsNotMatchingTags($tags = array())

    {

        $this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);

        return array();

    }

    /**

     * Return an array of stored cache ids which match any given tags

     *

     * In case of multiple tags, a logical AND is made between tags

     *

     * @param array $tags array of tags

     * @return array array of any matching cache ids (string)

     */

    public function getIdsMatchingAnyTags($tags = array())

    {

        $this->_log(self::TAGS_UNSUPPORTED_BY_SAVE_OF_APC_BACKEND);

        return array();

    }

    /**

     * Return an array of stored cache ids

     *

     * @return array array of stored cache ids (string)

     */

    public function getIds()

    {

        $res = array();

        $array = apc_cache_info('user', false);

        $records = $array['cache_list'];

        foreach ($records as $record) {

            $res[] = $record['info'];

        }

        return $res;

    }

    /**

     * Return an array of metadatas for the given cache id

     *

     * The array must include these keys :

     * - expire : the expire timestamp

     * - tags : a string array of tags

     * - mtime : timestamp of last modification time

     *

     * @param string $id cache id

     * @return array array of metadatas (false if the cache id is not found)

     */

    public function getMetadatas($id)

    {

        $tmp = apc_fetch($id);

        if (is_array($tmp)) {

            $data = $tmp[0];

            $mtime = $tmp[1];

            if (!isset($tmp[2])) {

                // because this record is only with 1.7 release

                // if old cache records are still there...

                return false;

            }

            $lifetime = $tmp[2];

            return array(

                'expire' => $mtime + $lifetime,

                'tags' => array(),

                'mtime' => $mtime

            );

        }

        return false;

    }

    /**

     * Give (if possible) an extra lifetime to the given cache id

     *

     * @param string $id cache id

     * @param int $extraLifetime

     * @return boolean true if ok

     */

    public function touch($id, $extraLifetime)

    {

        $tmp = apc_fetch($id);

        if (is_array($tmp)) {

            $data = $tmp[0];

            $mtime = $tmp[1];

            if (!isset($tmp[2])) {

                // because this record is only with 1.7 release

                // if old cache records are still there...

                return false;

            }

            $lifetime = $tmp[2];

            $newLifetime = $lifetime - (time() - $mtime) + $extraLifetime;

            if ($newLifetime <=0) {

                return false;

            }

            apc_store($id, array($data, time(), $newLifetime), $newLifetime);

            return true;

        }

        return false;

    }

    /**

     * Return an associative array of capabilities (booleans) of the backend

     *

     * The array must include these keys :

     * - automatic_cleaning (is automating cleaning necessary)

     * - tags (are tags supported)

     * - expired_read (is it possible to read expired cache records

     *                 (for doNotTestCacheValidity option for example))

     * - priority does the backend deal with priority when saving

     * - infinite_lifetime (is infinite lifetime can work with this backend)

     * - get_list (is it possible to get the list of cache ids and the complete list of tags)

     *

     * @return array associative of with capabilities

     */

    public function getCapabilities()

    {

        return array(

            'automatic_cleaning' => false,

            'tags' => false,

            'expired_read' => false,

            'priority' => false,

            'infinite_lifetime' => false,

            'get_list' => true

        );

    }

}