基于C++雪花算法工具类Snowflake -来自chatGPT

#include <iostream>
#include <chrono>
#include <stdexcept>class Snowflake {
private:// 雪花算法的各个参数static constexpr int64_t workerIdBits = 5;static constexpr int64_t datacenterIdBits = 5;static constexpr int64_t sequenceBits = 12;static constexpr int64_t maxWorkerId = -1 ^ (-1 << workerIdBits);static constexpr int64_t maxDatacenterId = -1 ^ (-1 << datacenterIdBits);static constexpr int64_t sequenceMask = -1 ^ (-1 << sequenceBits);int64_t workerId;int64_t datacenterId;int64_t sequence = 0;int64_t lastTimestamp = -1;public:Snowflake(int64_t workerId, int64_t datacenterId): workerId(workerId), datacenterId(datacenterId) {}int64_t generateId() {// 获取当前时间戳（毫秒级）auto timestamp = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();if (timestamp < lastTimestamp) {throw std::runtime_error("Invalid system clock!");}if (timestamp == lastTimestamp) {sequence = (sequence + 1) & sequenceMask;if (sequence == 0) {timestamp = waitNextMillis(lastTimestamp);}} else {sequence = 0;}lastTimestamp = timestamp;// 生成最终的唯一IDint64_t uniqueId = (timestamp << (workerIdBits + datacenterIdBits + sequenceBits)) |(datacenterId << (workerIdBits + sequenceBits)) |(workerId << sequenceBits) |sequence;return uniqueId;}private:int64_t waitNextMillis(int64_t lastTimestamp) {auto timestamp = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();while (timestamp <= lastTimestamp) {timestamp = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();}return timestamp;}
};int main() {Snowflake snowflake(1, 1);for (int i = 0; i < 10; i++) {int64_t uniqueId = snowflake.generateId();std::cout << uniqueId << std::endl;}return 0;
}

在上面的代码中，我们使用C++编写了一个名为Snowflake的类，用于生成Snowflake算法的唯一ID。主要属性和方法如下：

• Snowflake(int64_t workerId, int64_t datacenterId)：构造函数，用于初始化Snowflake算法的参数，包括工作节点ID（workerId）和数据中心ID（datacenterId）。
• int64_t generateId()：生成下一个唯一ID的方法。
• int64_t waitNextMillis(int64_t lastTimestamp)：阻塞到下一个毫秒，直到获得新的时间戳。

在主函数main()中，我们创建了一个Snowflake实例，并使用其generateId()方法生成了10个唯一ID，并将其打印到控制台上。