php 生成8位数唯一的激活码

    /**
    *生成激活码
    *
    */
    function showGenerationActivationCode(){
        #渠道类型id
        $channel_id=$_POST[‘channel‘];
        #根据渠道id去查询渠道英文名称
        $channelInfo = load_mysql ( "channelInfo" );
        $_res=$channelInfo->getInfoById($channel_id);
        $en_name=$_res[‘en_name‘];
        #活动类型
        $type=$_POST[‘active_type‘];
        #生成数量
        $nub=$_POST[‘nub‘];
        #接受生成的激活码的数组
        $array_ActivationCode=$this->showunique_rand(10000000,99999999,$nub);
        #生成code数组
        $code_array=$this->showAlgorithm_ActivationCode($type,$channel_id,$array_ActivationCode);
        #连接redis

      
         $redis=new Redis();
         $redis->connect(‘192.168.1.131‘,8899);
         //授权  
         $redis->auth("funova2014"); 
         

       

    }
    /**
    *生成code算法
    *type:活动类型[取前三位]
    *channel_id:渠道id[取前三位,不足以0填充]
    *array_ActivationCode:激活码数组
    *code算法格式=活动类型+渠道id+array_ActivationCode;
    *return code的数组 
    */
    function showAlgorithm_ActivationCode($type,$channel_id,$array_ActivationCode){
         #截取活动类型前位字符串
         $type=mb_substr($type,0,3,‘utf-8‘);
         #渠道id[取前三位,不足左边以0填充]
         $channel_id=str_pad($channel_id,3,‘0‘,STR_PAD_LEFT);
         #定义一个code算法数组
         $code_array=array();
         for($i=0;$i<count($array_ActivationCode);$i++){
             $code_array[$i]=$type.‘‘.$channel_id.‘‘.$array_ActivationCode[$i];
         }
        return  $code_array;
    }
    /**
    *生成8位数的激活码算法
    */
    function showunique_rand($min, $max, $num) {
       $count = 0;
       $return = array();
       while ($count < $num) {
        $return[] = mt_rand($min, $max);
        $return = array_flip(array_flip($return));
        $count = count($return);
      }
      return $return;
    }