C# Guid长度雪花简单生成器的示例代码_C#

C# Guid长度雪花简单生成器的示例代码

2022-10-24 12:09eflay C#

这篇文章主要介绍了C# Guid长度雪花简单生成器的示例代码，帮助大家更好的理解和使用c#，感兴趣的朋友可以了解下

标准的long雪花长度为64bit，还要浪费1bit，然后41位时间，10位workid，12位序列

guid长度128位，64位完整的时间tick，32位workid，32位序列，可谓随便用满非常豪华

也就是系统里可以根据需要有的地方存随机guid，有的地方存雪花guid，随便换

随后还有提取时间的方法，由于是64位完整时间，直接拿出来转时间就好了

这个类参考别人的代码，如果需要设计更完善的guid雪花，可以在github上或者nuget上找newid这个项目，老外写好的更完善的做法

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									public class GuidSnowFlakeGenerator

									 {

									  readonly uint _c;

									  int _a;

									  int _b;

									  long _lastTick;

									  uint _sequence;

									  SpinLock _spinLock;

									  public GuidSnowFlakeGenerator(uint workId)

									  {

									   _spinLock = new SpinLock(false);

									   _c = workId;

									  }

									  public Guid Next()

									  {

									   var ticks = DateTime.UtcNow.Ticks;

									   int a;

									   int b;

									   uint sequence;

									   var lockTaken = false;

									   try

									   {

									    _spinLock.Enter(ref lockTaken);

									    if (ticks > _lastTick)

									     UpdateTimestamp(ticks);

									    else if (_sequence == uint.MaxValue)

									     UpdateTimestamp(_lastTick + 1);

									    sequence = _sequence++;

									    a = _a;

									    b = _b;

									   }

									   finally

									   {

									    if (lockTaken)

									     _spinLock.Exit();

									   }

									   var s = sequence;

									   byte[] bytes = new byte[16];

									   bytes[0] = (byte)(a >> 24);

									   bytes[1] = (byte)(a >> 16);

									   bytes[2] = (byte)(a >> 8);

									   bytes[3] = (byte)a;

									   bytes[4] = (byte)(b >> 24);

									   bytes[5] = (byte)(b >> 16);

									   bytes[6] = (byte)(b >> 8);

									   bytes[7] = (byte)b;

									   bytes[8] = (byte)(_c >> 24);

									   bytes[9] = (byte)(_c >> 16);

									   bytes[10] = (byte)(_c >> 8);

									   bytes[11] = (byte)(_c);

									   bytes[12] = (byte)(s >> 24);

									   bytes[13] = (byte)(s >> 16);

									   bytes[14] = (byte)(s >> 8);

									   bytes[15] = (byte)(s >> 0);

									   return new Guid(bytes);

									  }

									  void UpdateTimestamp(long tick)

									  {

									   _b = (int)(tick & 0xFFFFFFFF);

									   _a = (int)(tick >> 32);

									   _sequence = 0;

									   _lastTick = tick;

									  }

									  public static DateTime GetTime(Guid guid)

									  {

									   var bytes = guid.ToByteArray();

									   long tick = (long)bytes[0] << 56;

									   tick += (long)bytes[1] << 48;

									   tick += (long)bytes[2] << 40;

									   tick += (long)bytes[3] << 32;

									   tick += (long)bytes[3] << 24;

									   tick += (long)bytes[3] << 16;

									   tick += (long)bytes[3] << 8;

									   tick += (long)bytes[3];

									   return new DateTime(tick, DateTimeKind.Utc);

									  }

									 }