如何使用Zend Framework缓存Cache？

<?php
require 'Zend/Loader.php';
Zend_Loader::loadClass('Zend_Cache');
Zend_Loader::loadClass('Zend_Config');
Zend_Loader::loadClass('Zend_Registry');
$config = new Zend_Config_Ini('configsecr/config.ini');
define('CACHE_DIR',FDROOT.'/'.'tmp/');
/*
配置文件config.ini：
[cache]
cache.needcache=1
cache.frontend.name=Core
cache.frontend.lifetime=7200
cache.frontend.automatic_serialization=1
cache.backend.name=File
*/
/*选项参考手册*/
/*建立cache对象*/
$frontendOptions = $config->cache->cache->frontend->toArray();
$backendOptions = $config->cache->cache->backend->toArray();
$frontendName = $frontendOptions['name'];
unset($frontendOptions['name']);
$backendName = $backendOptions['name'];
unset($backendOptions['name']);
if (empty($backendOptions['cache_dir']))
{
 $backendOptions['cache_dir'] = CACHE_DIR;
}
$_cache = Zend_Cache::factory($frontendName, $backendName, $frontendOptions, $backendOptions);
Zend_Registry::set('cache', $_cache);
/*使用cache*/
$viewRenderer = $_cache->load('viewRenderer'); //试图从缓存加载变量
if (!$viewRenderer instanceof Something)//加载不成功
{
 $viewRenderer = new Something();
 /*some other work*/
 $_cache->save($viewRenderer, 'viewRenderer');//保存变量到换存
}
/*这只是一种应用，还可以轻松缓存整页；也可将缓存存到数据库或者内存。*/
?>