C#, top-level, statements

https://learn.microsoft.com/en-us/dotnet/core/tutorials/top-level-templates

// See https://aka.ms/new-console-template for more information

Console.WriteLine("Hello, World!");

---------------------------------------------

using System; namespace MyApp { internal class Program { static void Main(string[] args) { Console.WriteLine("Hello World!"); } } }

--------------------------------------

namespace MyProject; class Program { static void Main(string[] args) { Console.WriteLine("Hello, World!"); } }

WebSocket, Example, Microsoft, C#, Learn, Samples

WebSocket, Example, Microsoft, C#, Learn, Samples

https://learn.microsoft.com/ru-ru/samples/microsoft/windows-universal-samples/websocket/

https://learn.microsoft.com/ru-ru/samples/browse/?languages=cppwinrt

ThreadPool, C#,

https://habr.com/ru/companies/skbkontur/articles/727532/

https://habr.com/ru/companies/skbkontur/articles/734670/

yield return

https://habr.com/ru/companies/skbkontur/articles/732704/

Sockets, Server, C#

https://www.youtube.com/watch?v=YxpIN49Bpes

https://www.youtube.com/watch?v=YxpIN49Bpes

C#, Thread, CurrentThread, ShowThreadInformation

https://learn.microsoft.com/en-us/dotnet/api/system.threading.thread.currentthread?view=net-7.0

Important Task.Run

--------------------------------------------------------------

using System;

using System.Collections.Generic;

using System.Threading;

using System.Threading.Tasks;

public class Example

{

   private static Object lockObj = new Object();

   private static Object rndLock = new Object();

   public static void Main()

   {

      Random rnd = new Random();

      var tasks = new List<Task<Double>>();

      ShowThreadInformation("Application");

Task<Double> t = Task.Run( () => { ShowThreadInformation("Main Task(Task #" + Task.CurrentId.ToString() + ")");

                                         for (int ctr = 1; ctr <= 20; ctr++)

                                           tasks.Add(Task.Factory.StartNew(

                                              () => { ShowThreadInformation("Task #" + Task.CurrentId.ToString());

                                                      long s = 0;

                                                      for (int n = 0; n <= 999999; n++) {

                                                         lock (rndLock) {

                                                            s += rnd.Next(1, 1000001);

                                                         }

                                                      }

                                                      return s/1000000.0;

                                                    } ));

                                        Task.WaitAll(tasks.ToArray());

                                        Double grandTotal = 0;

                                        Console.WriteLine("Means of each task: ");

                                        foreach (var child in tasks) {

                                           Console.WriteLine("   {0}", child.Result);

                                           grandTotal += child.Result;

                                        }

                                        Console.WriteLine();

                                        return grandTotal / 20;

                                   } );

      Console.WriteLine("Mean of Means: {0}", t.Result);

   }

  private static void ShowThreadInformation(String taskName)

  {

      String msg = null;

      Thread thread = Thread.CurrentThread;

      lock(lockObj) {

         msg = String.Format("{0} thread information\n", taskName) +

               String.Format("   Background: {0}\n", thread.IsBackground) +

               String.Format("   Thread Pool: {0}\n", thread.IsThreadPoolThread) +

               String.Format("   Thread ID: {0}\n", thread.ManagedThreadId);

      }

      Console.WriteLine(msg);

   }

}

// The example displays output like the following:

//       Application thread information

//          Background: False

//          Thread Pool: False

//          Thread ID: 1

//

//       Main Task(Task #1) thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 3

//

//       Task #2 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 4

//

//       Task #4 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 10

//

//       Task #3 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 9

//

//       Task #5 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 3

//

//       Task #7 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 5

//

//       Task #6 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 7

//

//       Task #8 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 6

//

//       Task #9 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 8

//

//       Task #10 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 9

//

//       Task #11 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 10

//

//       Task #12 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 6

//

//       Task #13 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 4

//

//       Task #14 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 3

//

//       Task #15 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 7

//

//       Task #16 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 5

//

//       Task #17 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 8

//

//       Task #18 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 9

//

//       Task #19 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 10

//

//       Task #20 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 4

//

//       Task #21 thread information

//          Background: True

//          Thread Pool: True

//          Thread ID: 7

//

//       Means of each task:

//          500038.740584

//          499810.422703

//          500217.558077

//          499868.534688

//          499295.505866

//          499893.475772

//          499601.454469

//          499828.532502

//          499606.183978

//          499700.276056

//          500415.894952

//          500005.874751

//          500042.237016

//          500092.764753

//          499998.798267

//          499623.054718

//          500018.784823

//          500286.865993

//          500052.68285

//          499764.363303

//

//       Mean of Means: 499908.10030605

Numeric, Types, C#

https://learn.microsoft.com/ru-ru/dotnet/csharp/language-reference/builtin-types/integral-numeric-types

CircularArray, C#, Enumerator

https://www.geeksforgeeks.org/circular-array/

Enumerator

https://docs.microsoft.com/ru-ru/dotnet/api/system.collections.ienumerable.getenumerator?view=net-5.0

https://docs.microsoft.com/ru-ru/dotnet/api/system.collections.generic.ienumerator-1?view=net-5.0

C#, Books

https://t.me/csharpproglib/2075

https://proglib.io/p/top-10-knig-po-c-ot-novichka-do-professionala-2021-10-10

Compress Strings With .NET and C#, Encoding, Compress

https://proglib.io/w/52991f4e

https://khalidabuhakmeh.com/compress-strings-with-dotnet-and-csharp

var value = "hello world";
var level = CompressionLevel.Fastest;

var bytes = Encoding.Unicode.GetBytes(value);
await using var input = new MemoryStream(bytes);
await using var output = new MemoryStream();

// GZipStream with BrotliStream
await using var stream = new GZipStream(output, level);

await input.CopyToAsync(stream);

var result = output.ToArray();
var resultString = Convert.ToBase64String(result);

public static class Compression
{
    public static async Task<CompressionResult> ToGzipAsync(this string value, CompressionLevel level = CompressionLevel.Fastest)
    {
        var bytes = Encoding.Unicode.GetBytes(value);
        await using var input = new MemoryStream(bytes);
        await using var output = new MemoryStream();
        await using var stream = new GZipStream(output, level);

        await input.CopyToAsync(stream);
        
        var result = output.ToArray();

        return new CompressionResult(
            new CompressionValue(value, bytes.Length),
            new CompressionValue(Convert.ToBase64String(result), result.Length),
            level,
            "Gzip");
    }
    
    public static async Task<CompressionResult> ToBrotliAsync(this string value, CompressionLevel level = CompressionLevel.Fastest)
    {
        var bytes = Encoding.Unicode.GetBytes(value);
        await using var input = new MemoryStream(bytes);
        await using var output = new MemoryStream();
        await using var stream = new BrotliStream(output, level);

        await input.CopyToAsync(stream);
        await stream.FlushAsync();
        
        var result = output.ToArray();

        return new CompressionResult(
            new CompressionValue(value, bytes.Length),
            new CompressionValue(Convert.ToBase64String(result), result.Length),
            level,
            "Brotli"
        );
    }

    public static async Task<string> FromGzipAsync(this string value)
    {
        var bytes = Convert.FromBase64String(value);
        await using var input = new MemoryStream(bytes);
        await using var output = new MemoryStream();
        await using var stream = new GZipStream(input, CompressionMode.Decompress);

        await stream.CopyToAsync(output);
        await stream.FlushAsync();
        
        return Encoding.Unicode.GetString(output.ToArray());
    }

    public static async Task<string> FromBrotliAsync(this string value)
    {
        var bytes = Convert.FromBase64String(value);
        await using var input = new MemoryStream(bytes);
        await using var output = new MemoryStream();
        await using var stream = new BrotliStream(input, CompressionMode.Decompress);

        await stream.CopyToAsync(output);
        
        return Encoding.Unicode.GetString(output.ToArray());
    }
}

public record CompressionResult(
    CompressionValue Original,
    CompressionValue Result,
    CompressionLevel Level,
    string Kind
)
{
    public int Difference =>
        Original.Size - Result.Size;

    public decimal Percent =>
      Math.Abs(Difference / (decimal) Original.Size);
}

public record CompressionValue(
    string Value,
    int Size
);
var comedyOfErrors = await File.ReadAllTextAsync("the-comedy-of-errors.txt");

var compressions = new[]
{
    await comedyOfErrors.ToGzipAsync(),
    await comedyOfErrors.ToBrotliAsync()
};

var table = new Table()
    .MarkdownBorder()
    .Title("compression in bytes")
    .ShowHeaders()
    .AddColumns("kind", "level", "before", "after", "difference", "% reduction");

foreach (var result in compressions)
{
    table
        .AddRow(
            result.Kind,
            result.Level.ToString(),
            result.Original.Size.ToString("N0"),
            result.Result.Size.ToString("N0"),
            result.Difference.ToString("N0"),
            result.Percent.ToString("P")
        );
}

AnsiConsole.Render(table);