mm_os/ulits/id_gen.js

MM_OS服务端架构，用于快速构建应用程序，支持网站建设、小程序后台、AI应用、物联网(IOT/AIOT)、游戏服务端等多种场景。

/**
 * ID生成器
 * 基于雪花算法实现，生成唯一ID
 */
class IdGen {
  /**
   * 构造函数
   * @param {object} config 配置参数
   * @param {number} config.worker_id 工作机器ID (0-31)
   * @param {number} config.dc_id 数据中心ID (0-31)
   * @param {number} config.sequence 序列号
   */
  constructor(config = {}) {
    this.worker_id = config.worker_id || 0;
    this.dc_id = config.dc_id || 0;
    this.sequence = config.sequence || 0;

    this.worker_id_bits = 5;
    this.dc_id_bits = 5;
    this.max_worker_id = -1 ^ (-1 << this.worker_id_bits);
    this.max_dc_id = -1 ^ (-1 << this.dc_id_bits);
    this.sequence_bits = 12;

    this.worker_id_shift = this.sequence_bits;
    this.dc_id_shift = this.sequence_bits + this.worker_id_bits;
    this.timestamp_left_shift = this.sequence_bits + this.worker_id_bits + this.dc_id_bits;
    this.sequence_mask = -1 ^ (-1 << this.sequence_bits);

    this.last_timestamp = -1;

    this.twepoch = 1288834974657;

    if (this.worker_id > this.max_worker_id || this.worker_id < 0) {
      throw new TypeError(`工作机器ID必须在0-${this.max_worker_id}之间`);
    }
    if (this.dc_id > this.max_dc_id || this.dc_id < 0) {
      throw new TypeError(`数据中心ID必须在0-${this.max_dc_id}之间`);
    }
  }
}

/**
 * 获取当前时间戳
 * @returns {number} 当前时间戳
 */
IdGen.prototype._timeGen = function () {
  return Date.now();
};

/**
 * 等待下一毫秒
 * @param {number} last_timestamp 上次时间戳
 * @returns {number} 新的时间戳
 */
IdGen.prototype._tilNextMillis = function (last_timestamp) {
  var timestamp = this._timeGen();
  while (timestamp <= last_timestamp) {
    timestamp = this._timeGen();
  }
  return timestamp;
};

/**
 * 生成下一个ID
 * @returns {string} 唯一ID
 */
IdGen.prototype.nextId = function () {
  var timestamp = this._timeGen();

  if (timestamp < this.last_timestamp) {
    throw new Error('时钟回拨，拒绝生成ID');
  }

  if (this.last_timestamp === timestamp) {
    this.sequence = (this.sequence + 1) & this.sequence_mask;
    if (this.sequence === 0) {
      timestamp = this._tilNextMillis(this.last_timestamp);
    }
  } else {
    this.sequence = 0;
  }

  this.last_timestamp = timestamp;

  var id = (BigInt(timestamp - this.twepoch) << BigInt(this.timestamp_left_shift))
    | (BigInt(this.dc_id) << BigInt(this.dc_id_shift))
    | (BigInt(this.worker_id) << BigInt(this.worker_id_shift))
    | BigInt(this.sequence);

  return id.toString();
};

/**
 * 生成带前缀的ID
 * @param {string} prefix 前缀
 * @returns {string} 带前缀的唯一ID
 */
IdGen.prototype.genId = function (prefix) {
  if (typeof prefix !== 'string') {
    throw new TypeError('前缀必须是字符串');
  }
  return prefix + '_' + this.nextId();
};

/**
 * 解析ID信息
 * @param {string} id ID字符串
 * @returns {object} ID信息对象
 */
IdGen.prototype.parseId = function (id) {
  if (typeof id !== 'string') {
    throw new TypeError('ID必须是字符串');
  }
  var num = BigInt(id.replace(/^[a-zA-Z_]+_/, ''));
  var timestamp = Number((num >> 22n) + BigInt(this.twepoch));
  var dc_id = Number((num >> 17n) & 31n);
  var worker_id = Number((num >> 12n) & 31n);
  var sequence = Number(num & 4095n);

  return {
    timestamp: timestamp,
    datetime: new Date(timestamp).toISOString(),
    dc_id: dc_id,
    worker_id: worker_id,
    sequence: sequence
  };
};

var idGen = new IdGen();

module.exports = {
  IdGen,
  idGen
};