<?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

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

 */

/** @see Zend_Cache_Backend_Interface */

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

/** @see Zend_Cache_Backend */

require_once 'Zend/Cache/Backend.php';

/**

 * @package    Zend_Cache

 * @subpackage Zend_Cache_Backend

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

 */

abstract class Zend_Cache_Backend_ZendServer extends Zend_Cache_Backend implements Zend_Cache_Backend_Interface

{

    /**

     * Available options

     *

     * =====> (string) namespace :

     * Namespace to be used for chaching operations

     *

     * @var array available options

     */

    protected $_options = array(

        'namespace' => 'zendframework'

    );

    /**

     * Store data

     *

     * @param mixed  $data        Object to store

     * @param string $id          Cache id

     * @param int    $timeToLive  Time to live in seconds

     * @throws Zend_Cache_Exception

     */

    abstract protected function _store($data, $id, $timeToLive);

    /**

     * Fetch data

     *

     * @param string $id          Cache id

     * @throws Zend_Cache_Exception

     */

    abstract protected function _fetch($id);

    /**

     * Unset data

     *

     * @param string $id          Cache id

     */

    abstract protected function _unset($id);

    /**

     * Clear cache

     */

    abstract protected function _clear();

    /**

     * 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 datas (or false)

     */

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

    {

        $tmp = $this->_fetch($id);

        if ($tmp !== null) {

            return $tmp;

        }

        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

     * @throws Zend_Cache_Exception

     */

    public function test($id)

    {

        $tmp = $this->_fetch('internal-metadatas---' . $id);

        if ($tmp !== false) {

            if (!is_array($tmp) || !isset($tmp['mtime'])) {

                Zend_Cache::throwException('Cache metadata for \'' . $id . '\' id is corrupted' );

            }

            return $tmp['mtime'];

        }

        return false;

    }

    /**

     * Compute & return the expire time

     *

     * @return int expire time (unix timestamp)

     */

    private function _expireTime($lifetime)

    {

        if ($lifetime === null) {

            return 9999999999;

        }

        return time() + $lifetime;

    }

    /**

     * 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);

        $metadatas = array(

            'mtime' => time(),

            'expire' => $this->_expireTime($lifetime),

        );

        if (count($tags) > 0) {

            $this->_log('Zend_Cache_Backend_ZendServer::save() : tags are unsupported by the ZendServer backends');

        }

        return  $this->_store($data, $id, $lifetime) &&

                $this->_store($metadatas, 'internal-metadatas---' . $id, $lifetime);

    }

    /**

     * Remove a cache record

     *

     * @param  string $id cache id

     * @return boolean true if no problem

     */

    public function remove($id)

    {

        $result1 = $this->_unset($id);

        $result2 = $this->_unset('internal-metadatas---' . $id);

        return $result1 && $result2;

    }

    /**

     * 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:

                $this->_clear();

                return true;

                break;

            case Zend_Cache::CLEANING_MODE_OLD:

                $this->_log("Zend_Cache_Backend_ZendServer::clean() : CLEANING_MODE_OLD is unsupported by the Zend Server backends.");

                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->_clear();

                $this->_log('Zend_Cache_Backend_ZendServer::clean() : tags are unsupported by the Zend Server backends.');

                break;

            default:

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

                break;

        }

    }

}