High performance Short Id

ShortId.cs

/// <summary>
/// High Performance and thread-safe ShortId in string format, preferred when a GUID is overkill.
/// </summary>
/// <remarks>
/// Based on long type (64 bit), so max length is 13, not recommanded for fewer than 6 chars. (6-13, 8 as default)
/// </remarks>
public static class ShortId
{
    /// <summary>
    /// 32 chars (2^5) removed some chars for better readablity
    /// </summary>
    private const string chars = "0123456789abcdefghjkmnpqrstvwxyz";

    public static string New([Range(6, 13)] int size = 8) => FromRandom(size);

    public static string FromDateTime([Range(6, 13)] int size = 8)
        => ToString(size, DateTime.Now.Ticks);

    public static string FromRandom([Range(6, 13)] int size = 8)
        => ToString(size, unchecked((long)Random.Shared.Next(int.MaxValue) * Random.Shared.Next(int.MaxValue)));

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    private static string ToString(int size, long value)
    {
        var output = new char[size];
        for (int i = size - 1; i >= 0; i--)
        {
            output[i] = chars[(int)(value % 32)];
            value >>= 5;
        }
        return new string(output);
    }
}

// **Benchmarks (each 1000 generations)**

//| Method       | Mean     | Error    | StdDev   | Gen0    | Allocated |
//|------------- |---------:|---------:|---------:|--------:|----------:|
//| NewGuid      | 87.70 us | 1.702 us | 2.272 us | 20.3857 |  93.75 KB |
//| FromDateTime | 97.66 us | 1.116 us | 0.989 us | 16.9678 |  78.13 KB |
//| FromRandom   | 45.05 us | 0.656 us | 0.582 us | 16.9678 |  78.13 KB |