<?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: BlackHole.php 20785 2010-01-31 09:43:03Z mikaelkael $

 */

/**

 * @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_BlackHole 

    extends Zend_Cache_Backend 

    implements Zend_Cache_Backend_ExtendedInterface

{

    /**

     * 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|false cached datas

     */

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

    {

        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)

    {

        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)

    {

        return true;

    }

    /**

     * Remove a cache record

     *

     * @param  string $id cache id

     * @return boolean true if no problem

     */

    public function remove($id)

    {

        return true;

    }

    /**

     * Clean some cache records

     *

     * Available modes are :

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

     * 'old'            => remove too old cache entries ($tags is not used)

     * 'matchingTag'    => remove cache entries matching all given tags

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

     * 'notMatchingTag' => remove cache entries not matching one of the given tags

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

     * 'matchingAnyTag' => remove cache entries matching any given tags

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

     *

     * @param  string $mode clean mode

     * @param  tags array $tags array of tags

     * @return boolean true if no problem

     */

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

    {

        return true;

    }

    /**

     * Return an array of stored cache ids

     *

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

     */

    public function getIds()

    {

        return array();

    }

    /**

     * Return an array of stored tags

     *

     * @return array array of stored tags (string)

     */

    public function getTags()

    {

        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())

    {

        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())

    {

        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())

    {

        return array();

    }

    /**

     * Return the filling percentage of the backend storage

     *

     * @return int integer between 0 and 100

     * @throws Zend_Cache_Exception

     */

    public function getFillingPercentage()

    {

        return 0;

    }

    /**

     * 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)

    {

        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)

    {

        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' => true,

            'tags'               => true,

            'expired_read'       => true,

            'priority'           => true,

            'infinite_lifetime'  => true,

            'get_list'           => true,

        );

    }

    /**

     * PUBLIC METHOD FOR UNIT TESTING ONLY !

     *

     * Force a cache record to expire

     *

     * @param string $id cache id

     */

    public function ___expire($id)

    {

    }

}