Typescript snowflake primary key generator

newly build SnowflakeIdGenerate.ts

// src/utils/Snowflake.ts
/** * Snowflake Primary key generation algorithm  *  The complete algorithm is generated ID The length is 20 position  *  But because of js Maximum 9007199254740991, More will overflow , More special treatment is needed . *  So set the length here as 16 position id. Turn down the data center to 1 position , Turn down the server to 1 position , Turn the sequence bit down to 10 position  *  This means that up to two data centers are supported , Each data center supports up to two servers  */
export class SnowflakeIdGenerate {
    
  private twepoch = 0;
  private workerIdBits = 1;
  private dataCenterIdBits = 1;
  private maxWrokerId = -1 ^ (-1 << this.workerIdBits); //  The value is ：1
  private maxDataCenterId = -1 ^ (-1 << this.dataCenterIdBits); //  The value is ：1
  private sequenceBits = 10;
  private workerIdShift = this.sequenceBits; //  The value is ：10
  private dataCenterIdShift = this.sequenceBits + this.workerIdBits; //  The value is ：11
  // private timestampLeftShift =
  // this.sequenceBits + this.workerIdBits + this.dataCenterIdBits; //  The value is ：12
  private sequenceMask = -1 ^ (-1 << this.sequenceBits); //  The value is ：4095
  private lastTimestamp = -1;
  private workerId = 1; // Set the default value , Take... From the environment variable 
  private dataCenterId = 1;
  private sequence = 0;

  constructor(_workerId = 0, _dataCenterId = 0, _sequence = 0) {
    
    if (this.workerId > this.maxWrokerId || this.workerId < 0) {
    
      throw new Error('config.worker_id must max than 0 and small than maxWrokerId-[' + this.maxWrokerId + ']');
    }
    if (this.dataCenterId > this.maxDataCenterId || this.dataCenterId < 0) {
    
      throw new Error(
        'config.data_center_id must max than 0 and small than maxDataCenterId-[' + this.maxDataCenterId + ']',
      );
    }
    this.workerId = _workerId;
    this.dataCenterId = _dataCenterId;
    this.sequence = _sequence;
  }

  private timeGen = (): number => {
    
    return Date.now();
  };

  private tilNextMillis = (lastTimestamp): number => {
    
    let timestamp = this.timeGen();
    while (timestamp <= lastTimestamp) {
    
      timestamp = this.timeGen();
    }
    return timestamp;
  };

  private nextId = (): number => {
    
    let timestamp: number = 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 + 1) & this.sequenceMask;
      if (this.sequence === 0) {
    
        timestamp = this.tilNextMillis(this.lastTimestamp);
      }
    } else {
    
      this.sequence = 0;
    }
    this.lastTimestamp = timestamp;
    // js  Maximum  9007199254740991, More will overflow 
    //  exceed  32  Bit length , Doing bit operations will overflow , Become negative , So here we do multiplication directly , Multiplication expands storage 
    const timestampPos = (timestamp - this.twepoch) * 4096;
    const dataCenterPos = this.dataCenterId << this.dataCenterIdShift;
    const workerPos = this.workerId << this.workerIdShift;
    return timestampPos + dataCenterPos + workerPos + this.sequence;
  };

  generate = (): number => {
    
    return this.nextId();
  };
}

Use

const idGenerate: SnowflakeIdGenerate = new SnowflakeIdGenerate();
console.log(idGenerate.generate());