<?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) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */


/**
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Backend
 * @copyright  Copyright (c) 2005-2008 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 $doNotTestCacheValidity If set to true, the cache validity won't be tested
     * @return string|false cached datas
     */
    public function load($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  array  $tags Array of tags
     * @return boolean true if no problem
     */
    public function clean($mode = Zend_Cache::CLEANING_MODE_ALL, $tags = array());

}
