Js Snowflake(雪花算法)生成随机ID的实现方法
编程学习 2021-07-04 14:06www.dzhlxh.cn编程入门
这篇文章主要介绍了Js Snowflake(雪花算法)生成随机ID的实现方法,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友们狼蚁网站SEO优化随着长沙网络推广来一起学习学习吧
1、snowflake-id插件
import SnowflakeId from "snowflake-id"; const guid = num => { const id= new SnowflakeId(); return id.generate(); };
2、原生使用
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) { thrownew Error('_workerId must max than 0 and small than maxWrokerId-[' + this.maxWrokerId + ']'); } if(this.dataCenterId > this.maxDataCenterId || this.dataCenterId < 0) { thrownew 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) { thrownew 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; }()); console.log(new Snowflake(1n, 1n, 0n).nextId()); //1141531990672150528n
控制台输出1141531990672150528n为bigint格式, .toString()转为字符串格式即可
3、ES6使用
import bigInt from "big-integer"; const guid = () => { const 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() { //new Date().getTime() === Date.now() 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; })(); return new Snowflake(1, 1, 0).nextId(); };
guid()即可调用
4、多次重复调用出现一样id的bug
console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime()); console.log(guid(), new Date().getTime());
修改如下
import SnowflakeId from "snowflake-id"; const guid = num => { const snowflake = new SnowflakeId(); let arr = []; for (let i = 0; i < num; i++) { arr.push(snowflake.generate()); } return num ? arr : snowflake.generate(); };
单个调用 guid()
n个调用 guid(n)
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