Redis+Lua锁

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一、Redis单例

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/**
 * Redis单例
 *
 * User: xiangqian
 * Date: 17/8/3
 * Time: 下午3:40
 */
namespace Model\Redis;
use \Redis;
class BaseModel
{
    private static $_instances = [];
    public $redis;
    /**
     * 构造方法
     *
     * BaseModel constructor.
     * @param array $config
     */
    private function __construct(array $config)
    {
        try {
            $this->redis = new Redis();
            $this->redis->connect($config['host'], $config['port'], $config['time_out']);
            $this->redis->auth($config['auth']);
        } catch (\RedisException $e) {
            exit($e->getMessage());
        }
    }
    /**
     * 获取实例
     *
     * @param array $config
     * @return BaseModel
     */
    public static function getInstance(array $config)
    {
        ksort($config);
        $key = md5(serialize($config));
        if (isset(self::$_instances[$key]) && self::$_instances[$key] instanceof self) {
            return self::$_instances[$key];
        }
        self::$_instances[$key] = new self($config);
        return self::$_instances[$key];
    }
    /**
     * 禁止克隆
     */
    public function __clone()
    {
        trigger_error('can not clone', E_USER_ERROR);
    }
}

二、Redis + Lua锁实现

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/**
 * Redis + Lua实现锁
 *
 * User: xiangqian
 * Date: 17/12/19
 * Time: 下午5:14
 */
namespace Model\Redis;
class Lock
{
    private static $redisConfig = [
        'host' => '127.0.0.1',
        'port' => 6379,
        'time_out' => 1,
        'auth' => '123456'
    ];
    /**
     * 加锁
     *
     * @param $key
     * @param $token
     * @param int $ttl
     * @return int
     */
    public static function lock($key, $token, $ttl = 100)
    {
        $script = '
            local ok = redis.call("setnx", KEYS[1], ARGV[1])
            if ok == 1 then
                redis.call("expire", KEYS[1], ARGV[2])
            end
            return ok';
        return BaseModel::getInstance(self::$redisConfig)->redis->eval($script, [$key, $token, $ttl], 1);
    }
    /**
     * 释放锁
     *
     * @param $key
     * @param $token
     * @return int
     */
    public static function unlock($key, $token)
    {
        $script = '
            if redis.call("get",KEYS[1]) == ARGV[1]
            then    
                return redis.call("del",KEYS[1])
            else    
                return 0
            end';
        return BaseModel::getInstance(self::$redisConfig)->redis->eval($script, [$key, $token], 1);
    }
}

三、使用示例

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$key = 'test_key';              //根据业务定名称
$token = uniqid($key);          //每个请求生成唯一的token, 防止被别的请求释放锁
Lock::lock($key, $token, 60);   //加锁
#do something with lock
Lock::unlock($key, $token);     //释放锁