获取随机数

 var bigInt = require("big-integer");

var Snowflake = /** @class */ (function() {
function Snowflake(_workerId, _dataCenterId, _sequence) {
    // this.twepoch = 1288834974657;
    this.twepoch = 0;
    this.workerIdBits = 5;
    this.dataCenterIdBits = 5;
    this.maxWrokerId = -1 ^ (-1 << this.workerIdBits); // 值为：31
    this.maxDataCenterId = -1 ^ (-1 << this.dataCenterIdBits); // 值为：31
    this.sequenceBits = 12;
    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 = -1 ^ (-1 << this.sequenceBits); // 值为：4095
    this.lastTimestamp = -1;
    //设置默认值,从环境变量取
    this.workerId = 1;
    this.dataCenterId = 1;
    this.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;
}
Snowflake.prototype.tilNextMillis = function(lastTimestamp) {
    var timestamp = this.timeGen();
    while (timestamp <= lastTimestamp) {
        timestamp = this.timeGen();
    }
    return timestamp;
};
Snowflake.prototype.timeGen = function() {
    return 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 + 1) & this.sequenceMask;
        if (this.sequence === 0) {
            timestamp = this.tilNextMillis(this.lastTimestamp);
        }
    } else {
        this.sequence = 0;
    }
    this.lastTimestamp = timestamp;
    var shiftNum = (this.dataCenterId << this.dataCenterIdShift) |
        (this.workerId << this.workerIdShift) |
        this.sequence; // dataCenterId:1,workerId:1,sequence:0  shiftNum:135168
    var nfirst = new bigInt(String(timestamp - this.twepoch), 10);
    nfirst = nfirst.shiftLeft(this.timestampLeftShift);
    var nnextId = nfirst.or(new bigInt(String(shiftNum), 10)).toString(10);
    return nnextId;
};
return Snowflake;

 }());
var work_id=parseInt(Math.random()*1000)%31;
var datacenter_id=parseInt(Math.random()*1000)%31;
var temptHG_Snowflake = new Snowflake(work_id, datacenter_id, 0);
exports.HG_Snowflake=temptHG_Snowflake;