wabbajack/Wabbajack.RateLimiter/NumberExtensions.cs

using System;

namespace Wabbajack.Common
{
    public static class NumberExtensions
    {
        private static readonly string[]
            Suffix = { "B", "KB", "MB", "GB", "TB", "PB", "EB" }; // Longs run out around EB

        public static string ToFileSizeString(this long byteCount)
        {
            if (byteCount == 0)
                return "0" + Suffix[0];
            var bytes = Math.Abs(byteCount);
            var place = Convert.ToInt32(Math.Floor(Math.Log(bytes, 1024)));
            var num = Math.Round(bytes / Math.Pow(1024, place), 1);
            return Math.Sign(byteCount) * num + Suffix[place];
        }

        public static string ToFileSizeString(this int byteCount)
        {
            return ToFileSizeString((long)byteCount);
        }
    }
}