PHP实现的Redis多库选择功能单例类

<?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;
  }
}
?>