在 windows 下运行 Memcache 时，请注意将 Memcached 更改为system/libraries/Cache/drivers/Cache_memcached.php.
这将使 Memcache 工作，但它不会使您的项目正确过期，因为 Memcache 使用第 4 个参数作为 TTL，而 Memcached 使用第 3 个参数作为 TTL，CI 只接受 3 个参数。
为了克服这个问题（并使其与 Memcache 和 Memcached 一起工作），您需要对 system/libraries/Cache/drivers/Cache_memcached.php 进行以下更改。
1) 声明一个新属性private $_is_memcache = FALSE;
2) 改变功能save()如下：
public function save($id, $data, $ttl = 60)
{
if($this->_is_memcache) {
return $this->_memcached->add($id, array($data, time(), $ttl), FALSE, $ttl);
} else {
return $this->_memcached->add($id, array($data, time(), $ttl), $ttl);
}
}
3）在函数_setup_memcached()中将行替换为$this->_memcached = new Memcached();：
if(class_exists("Memcached")) {
$this->_memcached = new Memcached();
} else {
$this->_memcached = new Memcache();
$this->_is_memcache = TRUE;
}
4）在函数is_supported ()中将行替换为if ( ! extension_loaded('memcached'))：
if ( !extension_loaded('memcached') && !extension_loaded('memcache'))
完成课程
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
* CodeIgniter
*
* An open source application development framework for PHP 4.3.2 or newer
*
* @package CodeIgniter
* @author ExpressionEngine Dev Team
* @copyright Copyright (c) 2006 - 2011 EllisLab, Inc.
* @license http://codeigniter.com/user_guide/license.html
* @link http://codeigniter.com
* @since Version 2.0
* @filesource
*/
// ------------------------------------------------------------------------
/**
* CodeIgniter Memcached Caching Class
*
* @package CodeIgniter
* @subpackage Libraries
* @category Core
* @author ExpressionEngine Dev Team
* @link
*/
class CI_Cache_memcached extends CI_Driver {
private $_memcached; // Holds the memcached object
private $_is_memcache = FALSE; // Identifies wether it's Memcache instead of Memcached
protected $_memcache_conf = array(
'default' => array(
'default_host' => '127.0.0.1',
'default_port' => 11211,
'default_weight' => 1
)
);
// ------------------------------------------------------------------------
/**
* Fetch from cache
*
* @param mixed unique key id
* @return mixed data on success/false on failure
*/
public function get($id)
{
$data = $this->_memcached->get($id);
return (is_array($data)) ? $data[0] : FALSE;
}
// ------------------------------------------------------------------------
/**
* Save
*
* @param string unique identifier
* @param mixed data being cached
* @param int time to live
* @return boolean true on success, false on failure
*/
public function save($id, $data, $ttl = 60)
{
if($this->_is_memcache) {
return $this->_memcached->add($id, array($data, time(), $ttl), FALSE, $ttl);
} else {
return $this->_memcached->add($id, array($data, time(), $ttl), $ttl);
}
}
// ------------------------------------------------------------------------
/**
* Delete from Cache
*
* @param mixed key to be deleted.
* @return boolean true on success, false on failure
*/
public function delete($id)
{
return $this->_memcached->delete($id);
}
// ------------------------------------------------------------------------
/**
* Clean the Cache
*
* @return boolean false on failure/true on success
*/
public function clean()
{
return $this->_memcached->flush();
}
// ------------------------------------------------------------------------
/**
* Cache Info
*
* @param null type not supported in memcached
* @return mixed array on success, false on failure
*/
public function cache_info($type = NULL)
{
return $this->_memcached->getStats();
}
// ------------------------------------------------------------------------
/**
* Get Cache Metadata
*
* @param mixed key to get cache metadata on
* @return mixed FALSE on failure, array on success.
*/
public function get_metadata($id)
{
$stored = $this->_memcached->get($id);
if (count($stored) !== 3)
{
return FALSE;
}
list($data, $time, $ttl) = $stored;
return array(
'expire' => $time + $ttl,
'mtime' => $time,
'data' => $data
);
}
// ------------------------------------------------------------------------
/**
* Setup memcached.
*/
private function _setup_memcached()
{
// Try to load memcached server info from the config file.
$CI =& get_instance();
if ($CI->config->load('memcached', TRUE, TRUE))
{
if (is_array($CI->config->config['memcached']))
{
$this->_memcache_conf = NULL;
foreach ($CI->config->config['memcached'] as $name => $conf)
{
$this->_memcache_conf[$name] = $conf;
}
}
}
if(class_exists("Memcached")) {
$this->_memcached = new Memcached();
} else {
$this->_memcached = new Memcache();
$this->_is_memcache = TRUE;
}
foreach ($this->_memcache_conf as $name => $cache_server)
{
if ( ! array_key_exists('hostname', $cache_server))
{
$cache_server['hostname'] = $this->_default_options['default_host'];
}
if ( ! array_key_exists('port', $cache_server))
{
$cache_server['port'] = $this->_default_options['default_port'];
}
if ( ! array_key_exists('weight', $cache_server))
{
$cache_server['weight'] = $this->_default_options['default_weight'];
}
$this->_memcached->addServer(
$cache_server['hostname'], $cache_server['port'], $cache_server['weight']
);
}
}
// ------------------------------------------------------------------------
/**
* Is supported
*
* Returns FALSE if memcached is not supported on the system.
* If it is, we setup the memcached object & return TRUE
*/
public function is_supported()
{
if ( !extension_loaded('memcached') && !extension_loaded('memcache'))
{
log_message('error', 'The Memcached Extension must be loaded to use Memcached Cache.');
return FALSE;
}
$this->_setup_memcached();
return TRUE;
}
// ------------------------------------------------------------------------
}
// End Class
/* End of file Cache_memcached.php */
/* Location: ./system/libraries/Cache/drivers/Cache_memcached.php */