FireDrillSystem_GuiGang_GPDHRQ/Assets/Scripts/Common/EntitiesManager/GUID.cs

using System;
using System.Threading;

public static class GUID
{
    private static ulong TimestampMask = 0xffffffff00000000;    //时间戳掩码
    private static ulong BigMask = 0x00000000f0000000;          //大区号掩码
    private static ulong SmallMask = 0x000000000ff00000;        //小区号掩码
    private static ulong BaseMask = 0x00000000000fffff;         //本地 ID 编号掩码
    private static int BaseId = 0;                              //本地 ID

    private static readonly DateTime Jan1st1970 = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);

    /// <summary>
    /// 根据大区号和小区号生成 ID。
    /// </summary>
    public static ulong NewGuid(uint big = 0, uint small = 0)
    {
        ulong timeStamp = (ulong)(DateTime.UtcNow - Jan1st1970).TotalSeconds;

        ulong newId = ((timeStamp << 32) & TimestampMask) |
                        ((big << 28) & BigMask) |
                        ((small << 20) & SmallMask) |
                        ((uint)BaseId & BaseMask);

        Interlocked.Increment(ref BaseId);

        return newId;
    }
}