cmc-oa/oa-ui-app/utils/snowFlake.js

export var Snowflake = /** @class */ (function() {
  function Snowflake(_workerId, _dataCenterId, _sequence) {
      this.twepoch = 1288834974657n;
      //this.twepoch = 0n;
      this.workerIdBits = 5n;
      this.dataCenterIdBits = 5n;
      this.maxWrokerId = -1n ^ (-1n << this.workerIdBits); // 值为：31
      this.maxDataCenterId = -1n ^ (-1n << this.dataCenterIdBits); // 值为：31
      this.sequenceBits = 12n;
      this.workerIdShift = this.sequenceBits; // 值为：12
      this.dataCenterIdShift = this.sequenceBits + this.workerIdBits; // 值为：17
      this.timestampLeftShift = this.sequenceBits + this.workerIdBits + this.dataCenterIdBits; // 值为：22
      this.sequenceMask = -1n ^ (-1n << this.sequenceBits); // 值为：4095
      this.lastTimestamp = -1n;
      //设置默认值,从环境变量取
      this.workerId = 1n;
      this.dataCenterId = 1n;
      this.sequence = 0n;
      if (this.workerId > this.maxWrokerId || this.workerId < 0) {
          throw new Error('_workerId must max than 0 and small than maxWrokerId-[' + this.maxWrokerId + ']');
      }
      if (this.dataCenterId > this.maxDataCenterId || this.dataCenterId < 0) {
          throw new Error('_dataCenterId must max than 0 and small than maxDataCenterId-[' + this.maxDataCenterId + ']');
      }

      this.workerId = BigInt(_workerId);
      this.dataCenterId = BigInt(_dataCenterId);
      this.sequence = BigInt(_sequence);
  }
  Snowflake.prototype.tilNextMillis = function(lastTimestamp) {
      var timestamp = this.timeGen();
      while (timestamp <= lastTimestamp) {
          timestamp = this.timeGen();
      }
      return BigInt(timestamp);
  };
  Snowflake.prototype.timeGen = function() {
      return BigInt(Date.now());
  };
  Snowflake.prototype.nextId = function() {
      var timestamp = this.timeGen();
      if (timestamp < this.lastTimestamp) {
          throw new Error('Clock moved backwards. Refusing to generate id for ' +
              (this.lastTimestamp - timestamp));
      }
      if (this.lastTimestamp === timestamp) {
          this.sequence = (this.sequence + 1n) & this.sequenceMask;
          if (this.sequence === 0n) {
              timestamp = this.tilNextMillis(this.lastTimestamp);
          }
      } else {
          this.sequence = 0n;
      }
      this.lastTimestamp = timestamp;
      return ((timestamp - this.twepoch) << this.timestampLeftShift) |
          (this.dataCenterId << this.dataCenterIdShift) |
          (this.workerId << this.workerIdShift) |
          this.sequence;
  };
  return Snowflake;
}());