using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.Globalization;

using System.Reflection;

using System.Runtime.Serialization;

​

using MessagePack;

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/58780225/how-to-save-a-serialized-messagepack-binary-file-in-c

    [MessagePackObject]

    public struct struct_realTime

    {

        [Key(0)]

        public int indexNum { get; set; }

        [Key(1)]

        public string currentTime { get; set; }

        [Key(2)]

        public string currentType { get; set; }

    }

​

    public static class MessagePackExtensions

    {

        const byte Array32 = 0xdd;

        const int Array32HeaderLength = 5;

        public static void AppendToFile<T>(Stream stream, T item)

        {

            if (stream == null)

                throw new ArgumentNullException(nameof(stream));

            if (!stream.CanSeek)

                throw new ArgumentException("!stream.CanSeek");

            stream.Position = 0;

            var buffer = new byte[Array32HeaderLength];

            var read = stream.Read(buffer, 0, Array32HeaderLength);

            stream.Position = 0;

            if (read == 0)

            {

                FormatArray32Header(buffer, 1);

                stream.Write(buffer, 0, Array32HeaderLength);

            }

            else

            {

                var count = ParseArray32Header(buffer, read);

                FormatArray32Header(buffer, count + 1);

                stream.Write(buffer, 0, Array32HeaderLength);

            }

            stream.Position = stream.Length;

            MessagePackSerializer.Serialize(stream, item);

        }

        static void FormatArray32Header(byte [] buffer, uint value)

        {

            buffer[0] = Array32;

            buffer[1] = unchecked((byte)(value >> 24));

            buffer[2] = unchecked((byte)(value >> 16));

            buffer[3] = unchecked((byte)(value >> 8));

            buffer[4] = unchecked((byte)value);

        }

        static uint ParseArray32Header(byte [] buffer, int readCount)

        {

            if (readCount < 5 || buffer[0] != Array32)

                throw new ArgumentException("Stream was not positioned on an Array32 header.");

            int i = 1;

            //https://stackoverflow.com/questions/8241060/how-to-get-little-endian-data-from-big-endian-in-c-sharp-using-bitconverter-toin

            //https://stackoverflow.com/a/8241127 by https://stackoverflow.com/users/23354/marc-gravell

            var value = unchecked((uint)((buffer[i++] << 24) | (buffer[i++] << 16) | (buffer[i++] << 8) | buffer[i++]));

            return value;

        }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var path = "Question58780225.bin";

            foreach (var count in new [] { 1, 2, 14, 15, 16, 17, ushort.MaxValue - 4, ushort.MaxValue + 4 })

            {

                try

                {

                    File.Delete(path);

                    Test(path, count);

                }

                finally

                {

                    File.Delete(path);

                }

            }

        }   

        static void Test(string filename, int expectedNumberOfRootItemsInFile)

        {

            int innerCount = 3;

​

            List<struct_realTime> list_temp = new List<struct_realTime>(innerCount);

​

            for (int num=0; num < innerCount; num++)

            {

                list_temp.Add(new struct_realTime

                              {

                                  indexNum = 1,

                                  currentTime = "time",

                                  currentType = "type",

                              });

            }

​

            Console.WriteLine("Testing: {0} repetitions of {1}", expectedNumberOfRootItemsInFile, MessagePackSerializer.ToJson(list_temp));

            for (int i = 0; i < expectedNumberOfRootItemsInFile; i++)

            {

                // Append each list_temp sequentially

                using (var fileStream = new FileStream(filename, FileMode.OpenOrCreate, FileAccess.ReadWrite))

                {

                    MessagePackExtensions.AppendToFile(fileStream, list_temp);

                }

            }

​

            List<List<struct_realTime>> allItemsInFile;

            using (var fileStream = File.OpenRead(filename))

            {

                allItemsInFile = MessagePackSerializer.Deserialize<List<List<struct_realTime>>>(fileStream);

            }

            Assert.IsTrue(allItemsInFile.Count == expectedNumberOfRootItemsInFile);

            Assert.IsTrue(allItemsInFile.All(i => i.SequenceEqual(list_temp)));

            Console.WriteLine("   Tests passed.");

        }   

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , GetNetCoreVersion());

            Console.WriteLine("MessagePack version: " + typeof(MessagePackSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.CodeBase.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​