<?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 Backend
 * @copyright  Copyright (c) 2005-2007 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
 
 
/**
 * @package    Zend_Cache
 * @subpackage Backend
 * @copyright  Copyright (c) 2005-2007 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
interface Zend_Cache_Backend_Interface
{
   
    /**
     * Set the frontend directives
     * 
     * @param array $directives assoc of directives
     */
    public function setDirectives($directives);
       
    /**
     * Test if a cache is available for the given id and (if yes) return it (false else)
     * 
     * Note : return value is always "string" (unserialization is done by the core not by the 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);
    
    /**
     * 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);
    
    /**
     * 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);
    
    /**
     * Remove a cache record
     * 
     * @param string $id cache id
     * @return boolean true if no problem
     */
    public function remove($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) 
     * Zend_Cache::CLEANING_MODE_MATCHING_TAG     => remove cache entries matching all given tags 
     *                                               ($tags can be an array of strings or a single string) 
     * Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG => remove cache entries not {matching one of the given tags}
     *                                               ($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());  
    
}
