PHP redis 分布式锁 实现

<?php
/**
 * redis 分布式锁
 */
class RedisLock{
    private $config;
    private $redis;
    public function __construct($config = []){
        $this->config = $config ? $config : ['host' => '127.0.0.1', 'port' => 6379];
        $this->redis = $this->connect();
    }
    public function connect(){
        $redis = new \Redis();
        $redis->connect($this->config['host'], $this->config['port']);
        return $redis;
    }

    /**
     * @param $scene 锁场景
     * @param $expire 锁有效期
     * @return bool
     */
    public function lock($scene = null , $expire = 10){
        if (!$scene || !$expire){
            return false;
        }
        // 生成随机值，锁标识
        $lockId = md5(uniqid());
        $result = $this->redis->set($scene, $lockId, ['NX', 'EX' => $expire]) ;

        if($result)
            return $lockId;
        else
            return $result;
    }

    /**
     * 解锁
     */
    public function unLock($scene, $lockId){

        $lua = <<<SCRIPT
       local key=KEYS[1]
            local value=ARGV[1]
            if(redis.call('get', key) == value)
            then
                return redis.call('del', key)
            end
SCRIPT;
        // 执行lua脚本
        return $this->redis->eval($lua, [$scene, $lockId], 1);
    }
}

//实现
$lock = new \Tests\Feature\RedisLock();

//第一次加锁
$res = $lock->Lock("test", 30);
var_dump($res); // 返回lockId
echo "<br>";
//第二次加锁
$res1 = $lock->Lock("test", 25);
var_dump($res1); //加锁失败 false
//解锁
if($res){
   $lock->unLock("test", $res);
}