<?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: ZendPlatform.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/**

 * @see Zend_Cache_Backend_Interface

 */

require_once 'Zend/Cache/Backend.php';

/**

 * @see Zend_Cache_Backend_Interface

 */

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

/**

 * Impementation of Zend Cache Backend using the Zend Platform (Output Content Caching)

 *

 * @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_ZendPlatform extends Zend_Cache_Backend implements Zend_Cache_Backend_Interface

{

    /**

     * internal ZP prefix

     */

    const TAGS_PREFIX = "internal_ZPtag:";

    /**

     * Constructor

     * Validate that the Zend Platform is loaded and licensed

     *

     * @param  array $options Associative array of options

     * @throws Zend_Cache_Exception

     * @return void

     */

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

    {

        if (!function_exists('accelerator_license_info')) {

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

        }

        if (!function_exists('accelerator_get_configuration')) {

            $licenseInfo = accelerator_license_info();

            Zend_Cache::throwException('The Zend Platform extension is not loaded correctly: '.$licenseInfo['failure_reason']);

        }

        $accConf = accelerator_get_configuration();

        if (@!$accConf['output_cache_licensed']) {

            Zend_Cache::throwException('The Zend Platform extension does not have the proper license to use content caching features');

        }

        if (@!$accConf['output_cache_enabled']) {

            Zend_Cache::throwException('The Zend Platform content caching feature must be enabled for using this backend, set the \'zend_accelerator.output_cache_enabled\' directive to On !');

        }

        if (!is_writable($accConf['output_cache_dir'])) {

            Zend_Cache::throwException('The cache copies directory \''. ini_get('zend_accelerator.output_cache_dir') .'\' must be writable !');

        }

        parent:: __construct($options);

    }

    /**

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

     *

     * @param  string  $id                     Cache id

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

     * @return string Cached data (or false)

     */

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

    {

        // doNotTestCacheValidity implemented by giving zero lifetime to the cache

        if ($doNotTestCacheValidity) {

            $lifetime = 0;

        } else {

            $lifetime = $this->_directives['lifetime'];

        }

        $res = output_cache_get($id, $lifetime);

        if($res) {

            return $res[0];

        } else {

            return false;

        }

    }

    /**

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

     *

     * @param  string $id Cache id

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

     */

    public function test($id)

    {

        $result = output_cache_get($id, $this->_directives['lifetime']);

        if ($result) {

            return $result[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             Data 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)

    {

        if (!($specificLifetime === false)) {

            $this->_log("Zend_Cache_Backend_ZendPlatform::save() : non false specifc lifetime is unsuported for this backend");

        }

        $lifetime = $this->_directives['lifetime'];

        $result1  = output_cache_put($id, array($data, time()));

        $result2  = (count($tags) == 0);

        foreach ($tags as $tag) {

            $tagid = self::TAGS_PREFIX.$tag;

            $old_tags = output_cache_get($tagid, $lifetime);

            if ($old_tags === false) {

                $old_tags = array();

            }

            $old_tags[$id] = $id;

            output_cache_remove_key($tagid);

            $result2 = output_cache_put($tagid, $old_tags);

        }

        return $result1 && $result2;

    }

    /**

     * Remove a cache record

     *

     * @param  string $id Cache id

     * @return boolean True if no problem

     */

    public function remove($id)

    {

        return output_cache_remove_key($id);

    }

    /**

     * Clean some cache records

     *

     * Available modes are :

     * Zend_Cache::CLEANING_MODE_ALL (default)    => remove all cache entries ($tags is not used)

     * Zend_Cache::CLEANING_MODE_OLD              => remove too old cache entries ($tags is not used)

     *                                               This mode is not supported in this backend

     * Zend_Cache::CLEANING_MODE_MATCHING_TAG     => remove cache entries matching all given tags

     *                                               ($tags can be an array of strings or a single string)

     * Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG => unsupported

     * Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG => remove cache entries matching any given tags

     *                                               ($tags can be an array of strings or a single string)

     *

     * @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:

            case Zend_Cache::CLEANING_MODE_OLD:

                $cache_dir = ini_get('zend_accelerator.output_cache_dir');

                if (!$cache_dir) {

                    return false;

                }

                $cache_dir .= '/.php_cache_api/';

                return $this->_clean($cache_dir, $mode);

                break;

            case Zend_Cache::CLEANING_MODE_MATCHING_TAG:

                $idlist = null;

                foreach ($tags as $tag) {

                    $next_idlist = output_cache_get(self::TAGS_PREFIX.$tag, $this->_directives['lifetime']);

                    if ($idlist) {

                        $idlist = array_intersect_assoc($idlist, $next_idlist);

                    } else {

                        $idlist = $next_idlist;

                    }

                    if (count($idlist) == 0) {

                        // if ID list is already empty - we may skip checking other IDs

                        $idlist = null;

                        break;

                    }

                }

                if ($idlist) {

                    foreach ($idlist as $id) {

                        output_cache_remove_key($id);

                    }

                }

                return true;

                break;

            case Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG:

                $this->_log("Zend_Cache_Backend_ZendPlatform::clean() : CLEANING_MODE_NOT_MATCHING_TAG is not supported by the Zend Platform backend");

                return false;

                break;

            case Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG:

                $idlist = null;

                foreach ($tags as $tag) {

                    $next_idlist = output_cache_get(self::TAGS_PREFIX.$tag, $this->_directives['lifetime']);

                    if ($idlist) {

                        $idlist = array_merge_recursive($idlist, $next_idlist);

                    } else {

                        $idlist = $next_idlist;

                    }

                    if (count($idlist) == 0) {

                        // if ID list is already empty - we may skip checking other IDs

                        $idlist = null;

                        break;

                    }

                }

                if ($idlist) {

                    foreach ($idlist as $id) {

                        output_cache_remove_key($id);

                    }

                }

                return true;

                break;

            default:

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

                break;

        }

    }

    /**

     * Clean a directory and recursivly go over it's subdirectories

     *

     * Remove all the cached files that need to be cleaned (according to mode and files mtime)

     *

     * @param  string $dir  Path of directory ot clean

     * @param  string $mode The same parameter as in Zend_Cache_Backend_ZendPlatform::clean()

     * @return boolean True if ok

     */

    private function _clean($dir, $mode)

    {

        $d = @dir($dir);

        if (!$d) {

            return false;

        }

        $result = true;

        while (false !== ($file = $d->read())) {

            if ($file == '.' || $file == '..') {

                continue;

            }

            $file = $d->path . $file;

            if (is_dir($file)) {

                $result = ($this->_clean($file .'/', $mode)) && ($result);

            } else {

                if ($mode == Zend_Cache::CLEANING_MODE_ALL) {

                    $result = ($this->_remove($file)) && ($result);

                } else if ($mode == Zend_Cache::CLEANING_MODE_OLD) {

                    // Files older than lifetime get deleted from cache

                    if ($this->_directives['lifetime'] !== null) {

                        if ((time() - @filemtime($file)) > $this->_directives['lifetime']) {

                            $result = ($this->_remove($file)) && ($result);

                        }

                    }

                }

            }

        }

        $d->close();

        return $result;

    }

    /**

     * Remove a file

     *

     * If we can't remove the file (because of locks or any problem), we will touch

     * the file to invalidate it

     *

     * @param  string $file Complete file path

     * @return boolean True if ok

     */

    private function _remove($file)

    {

        if (!@unlink($file)) {

            # If we can't remove the file (because of locks or any problem), we will touch

            # the file to invalidate it

            $this->_log("Zend_Cache_Backend_ZendPlatform::_remove() : we can't remove $file => we are going to try to invalidate it");

            if ($this->_directives['lifetime'] === null) {

                return false;

            }

            if (!file_exists($file)) {

                return false;

            }

            return @touch($file, time() - 2*abs($this->_directives['lifetime']));

        }

        return true;

    }

}