FreeSql/FreeSql/FreeUtil.cs

using SafeObjectPool;
using System;
using System.Collections.Concurrent;
using System.Data.Common;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;

public static class FreeUtil
{

    private static DateTime dt1970 = new DateTime(1970, 1, 1);
    private static ThreadLocal<Random> rnd = new ThreadLocal<Random>(() => new Random());
    private static readonly int __staticMachine = ((0x00ffffff & Environment.MachineName.GetHashCode()) +
#if NETSTANDARD1_5 || NETSTANDARD1_6
			1
#else
            AppDomain.CurrentDomain.Id
#endif
            ) & 0x00ffffff;
    private static readonly int __staticPid = Process.GetCurrentProcess().Id;
    private static int __staticIncrement = rnd.Value.Next();
    /// <summary>
    /// 生成类似Mongodb的ObjectId有序、不重复Guid
    /// </summary>
    /// <returns></returns>
    public static Guid NewMongodbId()
    {
        var now = DateTime.Now;
        var uninxtime = (int)now.Subtract(dt1970).TotalSeconds;
        int increment = Interlocked.Increment(ref __staticIncrement) & 0x00ffffff;
        var rand = rnd.Value.Next(0, int.MaxValue);
        var guid = $"{uninxtime.ToString("x8").PadLeft(8, '0')}{__staticMachine.ToString("x8").PadLeft(8, '0').Substring(2, 6)}{__staticPid.ToString("x8").PadLeft(8, '0').Substring(6, 2)}{increment.ToString("x8").PadLeft(8, '0')}{rand.ToString("x8").PadLeft(8, '0')}";
        return Guid.Parse(guid);
    }
}