php Redis多库选择单例类代码

<?php 
class MultiRedisConnect
/**
* hostname
*
* @var string
*/ 
const REDISHOSTNAME = "127.0.0.1"; 
 
/**
* port
*
* @var int
*/ 
const REDISPORT = 6379; 
 
/**
* timeout
*
* @var int
*/ 
const REDISTIMEOUT = 0; 
 
/**
* password
*
* @var string
*/ 
const REDISPASSWORD = "123456"; 
 
/**
* 类单例数组
*
* @var array
*/ 
private static $instance = array(); 
 
/**
* redis连接句柄
*
* @var object
*/ 
private $redis; 
 
/**
* hash的key
*
* @var int
*/ 
private $hash; 
 
/**
* 私有化构造函数,防止类外实例化
*
* @param int $dbnumber  
*/ 
private function __construct ($dbnumber) 
{ 
   $dbnumber = (int) $dbnumber; 
   $this->hash = $dbnumber; 
   $this->redis = new Redis(); 
   $this->redis->connect(self::REDISHOSTNAME, self::REDISPORT, self::REDISTIMEOUT); 
   $this->redis->auth(self::REDISPASSWORD); 
   $this->redis->select($dbnumber); 
} 
 
private function __clone () 
{} 
 
/**
* 获取类单例
*
* @param int $dbnumber  
* @return object
*/ 
public static function getRedisInstance ($dbnumber) 
{ 
   $hash = (int) $dbnumber; 

   if (! isset(self::$instance[$hash])) { 
  self::$instance[$hash] = new MultiRedisConnect($dbnumber); 
   } 

   return self::$instance[$hash]; 
} 
 
/**
* 获取redis的连接实例
*
* @return object
*/ 
public function getRedisConnect () 
{ 
   return $this->redis; 
} 
 
/**
* 关闭单例时做清理工作
*/ 
public function __destruct () 
{ 
   $key = $this->hash; 
   self::$instances[$key]->redis->close(); 
   self::$instances[$key] = null; 
} 
}
?>