实现算法

/*
* 薄雾算法
*
* 1      2                                                     48         56       64
* +------+-----------------------------------------------------+----------+----------+
* retain | increas                                             | salt     | sequence |
* +------+-----------------------------------------------------+----------+----------+
* 0      | 0000000000 0000000000 0000000000 0000000000 0000000 | 00000000 | 00000000 |
* +------+-----------------------------------------------------+------------+--------+
*
* 0. 最高位，占 1 位，保持为 0，使得值永远为正数；
* 1. 自增数，占 47 位，自增数在高位能保证结果值呈递增态势，遂低位可以为所欲为；
* 2. 随机因子一，占 8 位，上限数值 255，使结果值不可预测；
* 3. 随机因子二，占 8 位，上限数值 255，使结果值不可预测；
*
* 编号上限为百万亿级，上限值计算为 140737488355327 即 int64(1 << 47 - 1)，假设每天取值 10 亿，能使用 385+ 年
 */

class Mist
{
    public const saltBit = 8;          // 随机因子二进制位数

    public const saltShift = 8;        // 随机因子移位数

    public const increasShift = self::saltBit + self::saltShift; // 自增数移位数

    public $increas = 0;                // 自增数

    public $saltA = 0;                  // 随机因子一

    public $saltB = 0;                  // 随机因子二

    public function __construct($increas = 1)
    {
        $this->increas = $increas;
    }

    public function generate(): int
    {
        $this->increas = ++$this->increas;
        // 获取随机因子数值
        try {
            $this->saltA = random_int($this->saltA, 255);
        } catch (\Exception $e) {
            $this->saltA = $this->saltA++;
        }
        try {
            $this->saltB = random_int($this->saltB, 255);
        } catch (\Exception $e) {
            $this->saltB = $this->saltB++;
        }
        return (int) ($this->increas << self::increasShift) | ($this->saltA << self::saltShift) | $this->saltB;
    }
}

调用如下：

$uuid = (new Mist(1))->generate();
#> > 153290

转自：https://learnku.com/articles/69180