C# 分布式自增ID算法snowflake（雪花算法）

雪花算法（Snowflake algorithm）是一种生成唯一ID的算法，适用于分布式系统。在C#中实现雪花算法，可以参考以下代码：

using System;
using System.Threading;
using System.Threading.Tasks;
 
public class SnowflakeIdGenerator
{
    private const ulong Twepoch = 1288834974657; // 起始时间点 (2010-11-04T01:42:54.657Z)
    private const int WorkerBits = 10; // 机器ID所占的位数
    private const int DatacenterBits = 5; // 数据中心ID所占的位数
    private const int SequenceBits = 12; // 序列号所占的位数
 
    private const int WorkerIdShift = SequenceBits;
    private const int DatacenterIdShift = SequenceBits + WorkerBits;
    private const ulong TimestampLeftShift = (WorkerBits + DatacenterBits + SequenceBits);
 
    private const ulong SequenceMask = -1 ^ (-1 << SequenceBits);
    private const ulong WorkerIdMask = -1 ^ (-1 << WorkerBits);
    private const ulong DatacenterIdMask = -1 ^ (-1 << DatacenterBits);
 
    private readonly object _lockObj = new object();
    private ulong _lastTimestamp = 0;
    private ulong _sequence = 0;
 
    public ulong WorkerId { get; private set; }
    public ulong DatacenterId { get; private set; }
 
    public SnowflakeIdGenerator(ulong workerId, ulong datacenterId)
    {
        if (workerId > WorkerIdMask)
            throw new ArgumentException("workerId can't be greater than " + WorkerIdMask);
        if (datacenterId > DatacenterIdMask)
            throw new ArgumentException("datacenterId can't be greater than " + DatacenterIdMask);
 
        WorkerId = workerId;
        DatacenterId = datacenterId;
    }
 
    public ulong NextId()
    {
        lock (_lockObj)
        {
            ulong timestamp = TimeGen();
 
            if (timestamp < _lastTimestamp)
            {
                throw new InvalidOperationException($"Clock moved backwards, refusing to generate id for {_lastTimestamp - timestamp} milliseconds");
            }
 
            if (_lastTimestamp == timestamp)
            {
                _sequence = (_sequence + 1) & SequenceMask;
                if (_sequence == 0)
                {
                    timestamp = TilNextMillis(_lastTimestamp);
                }
            }
            else
            {
                _sequence = 0;
            }
 
            _lastTimestamp = timestamp;
 
            ulong id = ((ti