NetCoreServer

Ultra fast and low latency asynchronous socket server & client C# .NET Core library with support TCP, SSL, UDP, HTTP, HTTPS, WebSocket protocols and 10K connections problem solution.

NetCoreServer documentation
NetCoreServer downloads

Contents

• Features
• Requirements
• How to build?
• Examples
  • Example: TCP chat server
  • Example: TCP chat client
  • Example: SSL chat server
  • Example: SSL chat client
  • Example: UDP echo server
  • Example: UDP echo client
  • Example: UDP multicast server
  • Example: UDP multicast client
  • Example: HTTP server
  • Example: HTTP client
  • Example: HTTPS server
  • Example: HTTPS client
  • Example: WebSocket chat server
  • Example: WebSocket chat client
  • Example: WebSocket secure chat server
  • Example: WebSocket secure chat client
• Performance
  • Benchmark: Round-Trip
    • TCP echo server
    • SSL echo server
    • UDP echo server
    • WebSocket echo server
    • WebSocket secure echo server
  • Benchmark: Multicast
    • TCP multicast server
    • SSL multicast server
    • UDP multicast server
    • WebSocket multicast server
    • WebSocket secure multicast server
  • Benchmark: Web Server
    • HTTP Trace server
    • HTTPS Trace server
• OpenSSL certificates
  • Production
  • Development
  • Certificate Authority
  • SSL Server certificate
  • SSL Client certificate
  • Diffie-Hellman key exchange

Features

• Cross platform (Linux, OSX, Windows)
• Asynchronous communication
• Supported transport protocols: TCP, SSL, UDP, UDP multicast
• Supported Web protocols: HTTP, HTTPS, WebSocket, WebSocket secure
• Supported Swagger OpenAPI iterative documentation

Requirements

• Linux
• OSX
• Windows 10
• .NET 5.0
• 7-Zip
• cmake
• git
• Visual Studio

Optional:

• Rider

How to build?

Setup repository

git clone https://github.com/chronoxor/NetCoreServer.git
cd NetCoreServer

Linux

cd build
./unix.sh

OSX

cd build
./unix.sh

Windows (Visual Studio)

Open and build NetCoreServer.sln or run the build script:

cd build
vs.bat

The build script will create "release" directory with zip files:

• NetCoreServer.zip - C# Server assembly
• Benchmarks.zip - C# Server benchmarks
• Examples.zip - C# Server examples

Examples

Example: TCP chat server

Here comes the example of the TCP chat server. It handles multiple TCP client sessions and multicast received message from any session to all ones. Also it is possible to send admin message directly from the server.

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using NetCoreServer;

namespace TcpChatServer
{
    class ChatSession : TcpSession
    {
        public ChatSession(TcpServer server) : base(server) {}

        protected override void OnConnected()
        {
            Console.WriteLine($"Chat TCP session with Id {Id} connected!");

            // Send invite message
            string message = "Hello from TCP chat! Please send a message or '!' to disconnect the client!";
            SendAsync(message);
        }

        protected override void OnDisconnected()
        {
            Console.WriteLine($"Chat TCP session with Id {Id} disconnected!");
        }

        protected override void OnReceived(byte[] buffer, long offset, long size)
        {
            string message = Encoding.UTF8.GetString(buffer, (int)offset, (int)size);
            Console.WriteLine("Incoming: " + message);

            // Multicast message to all connected sessions
            Server.Multicast(message);

            // If the buffer starts with '!' the disconnect the current session
            if (message == "!")
                Disconnect();
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat TCP session caught an error with code {error}");
        }
    }

    class ChatServer : TcpServer
    {
        public ChatServer(IPAddress address, int port) : base(address, port) {}

        protected override TcpSession CreateSession() { return new ChatSession(this); }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat TCP server caught an error with code {error}");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // TCP server port
            int port = 1111;
            if (args.Length > 0)
                port = int.Parse(args[0]);

            Console.WriteLine($"TCP server port: {port}");

            Console.WriteLine();

            // Create a new TCP chat server
            var server = new ChatServer(IPAddress.Any, port);

            // Start the server
            Console.Write("Server starting...");
            server.Start();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the server or '!' to restart the server...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Restart the server
                if (line == "!")
                {
                    Console.Write("Server restarting...");
                    server.Restart();
                    Console.WriteLine("Done!");
                    continue;
                }

                // Multicast admin message to all sessions
                line = "(admin) " + line;
                server.Multicast(line);
            }

            // Stop the server
            Console.Write("Server stopping...");
            server.Stop();
            Console.WriteLine("Done!");
        }
    }
}

Example: TCP chat client

Here comes the example of the TCP chat client. It connects to the TCP chat server and allows to send message to it and receive new messages.

using System;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using TcpClient = NetCoreServer.TcpClient;

namespace TcpChatClient
{
    class ChatClient : TcpClient
    {
        public ChatClient(string address, int port) : base(address, port) {}

        public void DisconnectAndStop()
        {
            _stop = true;
            DisconnectAsync();
            while (IsConnected)
                Thread.Yield();
        }

        protected override void OnConnected()
        {
            Console.WriteLine($"Chat TCP client connected a new session with Id {Id}");
        }

        protected override void OnDisconnected()
        {
            Console.WriteLine($"Chat TCP client disconnected a session with Id {Id}");

            // Wait for a while...
            Thread.Sleep(1000);

            // Try to connect again
            if (!_stop)
                ConnectAsync();
        }

        protected override void OnReceived(byte[] buffer, long offset, long size)
        {
            Console.WriteLine(Encoding.UTF8.GetString(buffer, (int)offset, (int)size));
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat TCP client caught an error with code {error}");
        }

        private bool _stop;
    }

    class Program
    {
        static void Main(string[] args)
        {
            // TCP server address
            string address = "127.0.0.1";
            if (args.Length > 0)
                address = args[0];

            // TCP server port
            int port = 1111;
            if (args.Length > 1)
                port = int.Parse(args[1]);

            Console.WriteLine($"TCP server address: {address}");
            Console.WriteLine($"TCP server port: {port}");

            Console.WriteLine();

            // Create a new TCP chat client
            var client = new ChatClient(address, port);

            // Connect the client
            Console.Write("Client connecting...");
            client.ConnectAsync();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the client or '!' to reconnect the client...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Disconnect the client
                if (line == "!")
                {
                    Console.Write("Client disconnecting...");
                    client.DisconnectAsync();
                    Console.WriteLine("Done!");
                    continue;
                }

                // Send the entered text to the chat server
                client.SendAsync(line);
            }

            // Disconnect the client
            Console.Write("Client disconnecting...");
            client.DisconnectAndStop();
            Console.WriteLine("Done!");
        }
    }
}

Example: SSL chat server

Here comes the example of the SSL chat server. It handles multiple SSL client sessions and multicast received message from any session to all ones. Also it is possible to send admin message directly from the server.

This example is very similar to the TCP one except the code that prepares SSL context and handshake handler.

using System;
using System.Net;
using System.Net.Sockets;
using System.Security.Authentication;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using NetCoreServer;

namespace SslChatServer
{
    class ChatSession : SslSession
    {
        public ChatSession(SslServer server) : base(server) {}

        protected override void OnConnected()
        {
            Console.WriteLine($"Chat SSL session with Id {Id} connected!");
        }

        protected override void OnHandshaked()
        {
            Console.WriteLine($"Chat SSL session with Id {Id} handshaked!");

            // Send invite message
            string message = "Hello from SSL chat! Please send a message or '!' to disconnect the client!";
            Send(message);
        }

        protected override void OnDisconnected()
        {
            Console.WriteLine($"Chat SSL session with Id {Id} disconnected!");
        }

        protected override void OnReceived(byte[] buffer, long offset, long size)
        {
            string message = Encoding.UTF8.GetString(buffer, (int)offset, (int)size);
            Console.WriteLine("Incoming: " + message);

            // Multicast message to all connected sessions
            Server.Multicast(message);

            // If the buffer starts with '!' the disconnect the current session
            if (message == "!")
                Disconnect();
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat SSL session caught an error with code {error}");
        }
    }

    class ChatServer : SslServer
    {
        public ChatServer(SslContext context, IPAddress address, int port) : base(context, address, port) {}

        protected override SslSession CreateSession() { return new ChatSession(this); }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat SSL server caught an error with code {error}");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // SSL server port
            int port = 2222;
            if (args.Length > 0)
                port = int.Parse(args[0]);

            Console.WriteLine($"SSL server port: {port}");

            Console.WriteLine();

            // Create and prepare a new SSL server context
            var context = new SslContext(SslProtocols.Tls12, new X509Certificate2("server.pfx", "qwerty"));

            // Create a new SSL chat server
            var server = new ChatServer(context, IPAddress.Any, port);

            // Start the server
            Console.Write("Server starting...");
            server.Start();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the server or '!' to restart the server...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Restart the server
                if (line == "!")
                {
                    Console.Write("Server restarting...");
                    server.Restart();
                    Console.WriteLine("Done!");
                    continue;
                }

                // Multicast admin message to all sessions
                line = "(admin) " + line;
                server.Multicast(line);
            }

            // Stop the server
            Console.Write("Server stopping...");
            server.Stop();
            Console.WriteLine("Done!");
        }
    }
}

Example: SSL chat client

Here comes the example of the SSL chat client. It connects to the SSL chat server and allows to send message to it and receive new messages.

This example is very similar to the TCP one except the code that prepares SSL context and handshake handler.

using System;
using System.Net.Sockets;
using System.Security.Authentication;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Threading;
using NetCoreServer;

namespace SslChatClient
{
    class ChatClient : SslClient
    {
        public ChatClient(SslContext context, string address, int port) : base(context, address, port) {}

        public void DisconnectAndStop()
        {
            _stop = true;
            DisconnectAsync();
            while (IsConnected)
                Thread.Yield();
        }

        protected override void OnConnected()
        {
            Console.WriteLine($"Chat SSL client connected a new session with Id {Id}");
        }

        protected override void OnHandshaked()
        {
            Console.WriteLine($"Chat SSL client handshaked a new session with Id {Id}");
        }

        protected override void OnDisconnected()
        {
            Console.WriteLine($"Chat SSL client disconnected a session with Id {Id}");

            // Wait for a while...
            Thread.Sleep(1000);

            // Try to connect again
            if (!_stop)
                ConnectAsync();
        }

        protected override void OnReceived(byte[] buffer, long offset, long size)
        {
            Console.WriteLine(Encoding.UTF8.GetString(buffer, (int)offset, (int)size));
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat SSL client caught an error with code {error}");
        }

        private bool _stop;
    }

    class Program
    {
        static void Main(string[] args)
        {
            // SSL server address
            string address = "127.0.0.1";
            if (args.Length > 0)
                address = args[0];

            // SSL server port
            int port = 2222;
            if (args.Length > 1)
                port = int.Parse(args[1]);

            Console.WriteLine($"SSL server address: {address}");
            Console.WriteLine($"SSL server port: {port}");

            Console.WriteLine();

            // Create and prepare a new SSL client context
            var context = new SslContext(SslProtocols.Tls12, new X509Certificate2("client.pfx", "qwerty"), (sender, certificate, chain, sslPolicyErrors) => true);

            // Create a new SSL chat client
            var client = new ChatClient(context, address, port);

            // Connect the client
            Console.Write("Client connecting...");
            client.ConnectAsync();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the client or '!' to reconnect the client...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Disconnect the client
                if (line == "!")
                {
                    Console.Write("Client disconnecting...");
                    client.DisconnectAsync();
                    Console.WriteLine("Done!");
                    continue;
                }

                // Send the entered text to the chat server
                client.SendAsync(line);
            }

            // Disconnect the client
            Console.Write("Client disconnecting...");
            client.DisconnectAndStop();
            Console.WriteLine("Done!");
        }
    }
}

Example: UDP echo server

Here comes the example of the UDP echo server. It receives a datagram mesage from any UDP client and resend it back without any changes.

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using NetCoreServer;

namespace UdpEchoServer
{
    class EchoServer : UdpServer
    {
        public EchoServer(IPAddress address, int port) : base(address, port) {}

        protected override void OnStarted()
        {
            // Start receive datagrams
            ReceiveAsync();
        }

        protected override void OnReceived(EndPoint endpoint, byte[] buffer, long offset, long size)
        {
            Console.WriteLine("Incoming: " + Encoding.UTF8.GetString(buffer, (int)offset, (int)size));

            // Echo the message back to the sender
            SendAsync(endpoint, buffer, 0, size);
        }

        protected override void OnSent(EndPoint endpoint, long sent)
        {
            // Continue receive datagrams
            ReceiveAsync();
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Echo UDP server caught an error with code {error}");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // UDP server port
            int port = 3333;
            if (args.Length > 0)
                port = int.Parse(args[0]);

            Console.WriteLine($"UDP server port: {port}");

            Console.WriteLine();

            // Create a new UDP echo server
            var server = new EchoServer(IPAddress.Any, port);

            // Start the server
            Console.Write("Server starting...");
            server.Start();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the server or '!' to restart the server...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Restart the server
                if (line == "!")
                {
                    Console.Write("Server restarting...");
                    server.Restart();
                    Console.WriteLine("Done!");
                }
            }

            // Stop the server
            Console.Write("Server stopping...");
            server.Stop();
            Console.WriteLine("Done!");
        }
    }
}

Example: UDP echo client

Here comes the example of the UDP echo client. It sends user datagram message to UDP server and listen for response.

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using UdpClient = NetCoreServer.UdpClient;

namespace UdpEchoClient
{
    class EchoClient : UdpClient
    {
        public EchoClient(string address, int port) : base(address, port) {}

        public void DisconnectAndStop()
        {
            _stop = true;
            Disconnect();
            while (IsConnected)
                Thread.Yield();
        }

        protected override void OnConnected()
        {
            Console.WriteLine($"Echo UDP client connected a new session with Id {Id}");

            // Start receive datagrams
            ReceiveAsync();
        }

        protected override void OnDisconnected()
        {
            Console.WriteLine($"Echo UDP client disconnected a session with Id {Id}");

            // Wait for a while...
            Thread.Sleep(1000);

            // Try to connect again
            if (!_stop)
                Connect();
        }

        protected override void OnReceived(EndPoint endpoint, byte[] buffer, long offset, long size)
        {
            Console.WriteLine("Incoming: " + Encoding.UTF8.GetString(buffer, (int)offset, (int)size));

            // Continue receive datagrams
            ReceiveAsync();
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Echo UDP client caught an error with code {error}");
        }

        private bool _stop;
    }

    class Program
    {
        static void Main(string[] args)
        {
            // UDP server address
            string address = "127.0.0.1";
            if (args.Length > 0)
                address = args[0];

            // UDP server port
            int port = 3333;
            if (args.Length > 1)
                port = int.Parse(args[1]);

            Console.WriteLine($"UDP server address: {address}");
            Console.WriteLine($"UDP server port: {port}");

            Console.WriteLine();

            // Create a new TCP chat client
            var client = new EchoClient(address, port);

            // Connect the client
            Console.Write("Client connecting...");
            client.Connect();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the client or '!' to reconnect the client...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Disconnect the client
                if (line == "!")
                {
                    Console.Write("Client disconnecting...");
                    client.Disconnect();
                    Console.WriteLine("Done!");
                    continue;
                }

                // Send the entered text to the chat server
                client.Send(line);
            }

            // Disconnect the client
            Console.Write("Client disconnecting...");
            client.DisconnectAndStop();
            Console.WriteLine("Done!");
        }
    }
}

Example: UDP multicast server

Here comes the example of the UDP multicast server. It use multicast IP address to multicast datagram messages to all client that joined corresponding UDP multicast group.

using System;
using System.Net;
using System.Net.Sockets;
using NetCoreServer;

namespace UdpMulticastServer
{
    class MulticastServer : UdpServer
    {
        public MulticastServer(IPAddress address, int port) : base(address, port) {}

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Multicast UDP server caught an error with code {error}");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // UDP multicast address
            string multicastAddress = "239.255.0.1";
            if (args.Length > 0)
                multicastAddress = args[0];

            // UDP multicast port
            int multicastPort = 3334;
            if (args.Length > 1)
                multicastPort = int.Parse(args[1]);

            Console.WriteLine($"UDP multicast address: {multicastAddress}");
            Console.WriteLine($"UDP multicast port: {multicastPort}");

            Console.WriteLine();

            // Create a new UDP multicast server
            var server = new MulticastServer(IPAddress.Any, 0);

            // Start the multicast server
            Console.Write("Server starting...");
            server.Start(multicastAddress, multicastPort);
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the server or '!' to restart the server...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Restart the server
                if (line == "!")
                {
                    Console.Write("Server restarting...");
                    server.Restart();
                    Console.WriteLine("Done!");
                    continue;
                }

                // Multicast admin message to all sessions
                line = "(admin) " + line;
                server.Multicast(line);
            }

            // Stop the server
            Console.Write("Server stopping...");
            server.Stop();
            Console.WriteLine("Done!");
        }
    }
}

Example: UDP multicast client

Here comes the example of the UDP multicast client. It use multicast IP address and joins UDP multicast group in order to receive multicasted datagram messages from UDP server.

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using UdpClient = NetCoreServer.UdpClient;

namespace UdpMulticastClient
{
    class MulticastClient : UdpClient
    {
        public string Multicast;

        public MulticastClient(string address, int port) : base(address, port) {}

        public void DisconnectAndStop()
        {
            _stop = true;
            Disconnect();
            while (IsConnected)
                Thread.Yield();
        }

        protected override void OnConnected()
        {
            Console.WriteLine($"Multicast UDP client connected a new session with Id {Id}");

            // Join UDP multicast group
            JoinMulticastGroup(Multicast);

            // Start receive datagrams
            ReceiveAsync();
        }

        protected override void OnDisconnected()
        {
            Console.WriteLine($"Multicast UDP client disconnected a session with Id {Id}");

            // Wait for a while...
            Thread.Sleep(1000);

            // Try to connect again
            if (!_stop)
                Connect();
        }

        protected override void OnReceived(EndPoint endpoint, byte[] buffer, long offset, long size)
        {
            Console.WriteLine("Incoming: " + Encoding.UTF8.GetString(buffer, (int)offset, (int)size));

            // Continue receive datagrams
            ReceiveAsync();
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Multicast UDP client caught an error with code {error}");
        }

        private bool _stop;
    }

    class Program
    {
        static void Main(string[] args)
        {
            // UDP listen address
            string listenAddress = "0.0.0.0";
            if (args.Length > 0)
                listenAddress = args[0];

            // UDP multicast address
            string multicastAddress = "239.255.0.1";
            if (args.Length > 1)
                multicastAddress = args[1];

            // UDP multicast port
            int multicastPort = 3334;
            if (args.Length > 2)
                multicastPort = int.Parse(args[2]);

            Console.WriteLine($"UDP listen address: {listenAddress}");
            Console.WriteLine($"UDP multicast address: {multicastAddress}");
            Console.WriteLine($"UDP multicast port: {multicastPort}");

            Console.WriteLine();

            // Create a new TCP chat client
            var client = new MulticastClient(listenAddress, multicastPort);
            client.SetupMulticast(true);
            client.Multicast = multicastAddress;

            // Connect the client
            Console.Write("Client connecting...");
            client.Connect();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the client or '!' to reconnect the client...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Disconnect the client
                if (line == "!")
                {
                    Console.Write("Client disconnecting...");
                    client.Disconnect();
                    Console.WriteLine("Done!");
                    continue;
                }
            }

            // Disconnect the client
            Console.Write("Client disconnecting...");
            client.DisconnectAndStop();
            Console.WriteLine("Done!");
        }
    }
}

Example: HTTP server

Here comes the example of the HTTP cache server. It allows to manipulate cache data with HTTP methods (GET, POST, PUT and DELETE).

Use the following link to open Swagger OpenAPI iterative documentation: http://localhost:8080/api/index.html

using System;
using System.Collections.Concurrent;
using System.Net;
using System.Net.Sockets;
using System.Text;
using NetCoreServer;

namespace HttpServer
{
    class CommonCache
    {
        public static CommonCache GetInstance()
        {
            if (_instance == null)
                _instance = new CommonCache();
            return _instance;
        }

        public string GetAllCache()
        {
            var result = new StringBuilder();
            result.Append("[\n");
            foreach (var item in _cache)
            {
                result.Append("  {\n");
                result.AppendFormat($"    \"key\": \"{item.Key}\",\n");
                result.AppendFormat($"    \"value\": \"{item.Value}\",\n");
                result.Append("  },\n");
            }
            result.Append("]\n");
            return result.ToString();
        }

        public bool GetCacheValue(string key, out string value)
        {
            return _cache.TryGetValue(key, out value);
        }

        public void PutCacheValue(string key, string value)
        {
            _cache[key] = value;
        }

        public bool DeleteCacheValue(string key, out string value)
        {
            return _cache.TryRemove(key, out value);
        }

        private readonly ConcurrentDictionary<string, string> _cache = new ConcurrentDictionary<string, string>();
        private static CommonCache _instance;
    }

    class HttpCacheSession : HttpSession
    {
        public HttpCacheSession(NetCoreServer.HttpServer server) : base(server) {}

        protected override void OnReceivedRequest(HttpRequest request)
        {
            // Show HTTP request content
            Console.WriteLine(request);

            // Process HTTP request methods
            if (request.Method == "HEAD")
                SendResponseAsync(Response.MakeHeadResponse());
            else if (request.Method == "GET")
            {
                string key = request.Url;

                // Decode the key value
                key = Uri.UnescapeDataString(key);
                key = key.Replace("/api/cache", "", StringComparison.InvariantCultureIgnoreCase);
                key = key.Replace("?key=", "", StringComparison.InvariantCultureIgnoreCase);

                if (string.IsNullOrEmpty(key))
                {
                    // Response with all cache values
                    SendResponseAsync(Response.MakeGetResponse(CommonCache.GetInstance().GetAllCache(), "application/json; charset=UTF-8"));
                }
                // Get the cache value by the given key
                else if (CommonCache.GetInstance().GetCacheValue(key, out var value))
                {
                    // Response with the cache value
                    SendResponseAsync(Response.MakeGetResponse(value));
                }
                else
                    SendResponseAsync(Response.MakeErrorResponse("Required cache value was not found for the key: " + key, 404));
            }
            else if ((request.Method == "POST") || (request.Method == "PUT"))
            {
                string key = request.Url;
                string value = request.Body;

                // Decode the key value
                key = Uri.UnescapeDataString(key);
                key = key.Replace("/api/cache", "", StringComparison.InvariantCultureIgnoreCase);
                key = key.Replace("?key=", "", StringComparison.InvariantCultureIgnoreCase);

                // Put the cache value
                CommonCache.GetInstance().PutCacheValue(key, value);

                // Response with the cache value
                SendResponseAsync(Response.MakeOkResponse());
            }
            else if (request.Method == "DELETE")
            {
                string key = request.Url;

                // Decode the key value
                key = Uri.UnescapeDataString(key);
                key = key.Replace("/api/cache", "", StringComparison.InvariantCultureIgnoreCase);
                key = key.Replace("?key=", "", StringComparison.InvariantCultureIgnoreCase);

                // Delete the cache value
                if (CommonCache.GetInstance().DeleteCacheValue(key, out var value))
                {
                    // Response with the cache value
                    SendResponseAsync(Response.MakeGetResponse(value));
                }
                else
                    SendResponseAsync(Response.MakeErrorResponse("Deleted cache value was not found for the key: " + key, 404));
            }
            else if (request.Method == "OPTIONS")
                SendResponseAsync(Response.MakeOptionsResponse());
            else if (request.Method == "TRACE")
                SendResponseAsync(Response.MakeTraceResponse(request.Cache.Data));
            else
                SendResponseAsync(Response.MakeErrorResponse("Unsupported HTTP method: " + request.Method));
        }

        protected override void OnReceivedRequestError(HttpRequest request, string error)
        {
            Console.WriteLine($"Request error: {error}");
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"HTTP session caught an error: {error}");
        }
    }

    class HttpCacheServer : NetCoreServer.HttpServer
    {
        public HttpCacheServer(IPAddress address, int port) : base(address, port) {}

        protected override TcpSession CreateSession() { return new HttpCacheSession(this); }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"HTTP session caught an error: {error}");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // HTTP server port
            int port = 8080;
            if (args.Length > 0)
                port = int.Parse(args[0]);
            // HTTP server content path
            string www = "../../../../../www/api";
            if (args.Length > 1)
                www = args[1];

            Console.WriteLine($"HTTP server port: {port}");
            Console.WriteLine($"HTTP server static content path: {www}");
            Console.WriteLine($"HTTP server website: http://localhost:{port}/api/index.html");

            Console.WriteLine();

            // Create a new HTTP server
            var server = new HttpCacheServer(IPAddress.Any, port);
            server.AddStaticContent(www, "/api");

            // Start the server
            Console.Write("Server starting...");
            server.Start();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the server or '!' to restart the server...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Restart the server
                if (line == "!")
                {
                    Console.Write("Server restarting...");
                    server.Restart();
                    Console.WriteLine("Done!");
                }
            }

            // Stop the server
            Console.Write("Server stopping...");
            server.Stop();
            Console.WriteLine("Done!");
        }
    }
}

Example: HTTP client

Here comes the example of the HTTP client. It allows to send HTTP requests (GET, POST, PUT and DELETE) and receive HTTP responses.

using System;
using NetCoreServer;

namespace HttpClient
{
    class Program
    {
        static void Main(string[] args)
        {
            // HTTP server address
            string address = "127.0.0.1";
            if (args.Length > 0)
                address = args[0];

            // HTTP server port
            int port = 8080;
            if (args.Length > 1)
                port = int.Parse(args[1]);

            Console.WriteLine($"HTTP server address: {address}");
            Console.WriteLine($"HTTP server port: {port}");

            Console.WriteLine();

            // Create a new HTTP client
            var client = new HttpClientEx(address, port);

            Console.WriteLine("Press Enter to stop the client or '!' to reconnect the client...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Reconnect the client
                if (line == "!")
                {
                    Console.Write("Client reconnecting...");
                    if (client.IsConnected)
                        client.ReconnectAsync();
                    else
                        client.ConnectAsync();
                    Console.WriteLine("Done!");
                    continue;
                }

                var commands = line.Split(' ');
                if (commands.Length < 2)
                {
                    Console.WriteLine("HTTP method and URL must be entered!");
                    continue;
                }

                if (commands[0].ToUpper() == "HEAD")
                {
                    var response = client.SendHeadRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "GET")
                {
                    var response = client.SendGetRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "POST")
                {
                    if (commands.Length < 3)
                    {
                        Console.WriteLine("HTTP method, URL and body must be entered!");
                        continue;
                    }

                    var response = client.SendPostRequest(commands[1], commands[2]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "PUT")
                {
                    if (commands.Length < 3)
                    {
                        Console.WriteLine("HTTP method, URL and body must be entered!");
                        continue;
                    }

                    var response = client.SendPutRequest(commands[1], commands[2]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "DELETE")
                {
                    var response = client.SendDeleteRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "OPTIONS")
                {
                    var response = client.SendOptionsRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "TRACE")
                {
                    var response = client.SendTraceRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else
                    Console.WriteLine("Unknown HTTP method");
            }

            // Disconnect the client
            Console.Write("Client disconnecting...");
            client.Disconnect();
            Console.WriteLine("Done!");
        }
    }
}

Example: HTTPS server

Here comes the example of the HTTPS cache server. It allows to manipulate cache data with HTTP methods (GET, POST, PUT and DELETE) with secured transport protocol.

Use the following link to open Swagger OpenAPI iterative documentation: https://localhost:8443/api/index.html

using System;
using System.Collections.Concurrent;
using System.Net;
using System.Net.Sockets;
using System.Security.Authentication;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using NetCoreServer;

namespace HttpsServer
{
    class CommonCache
    {
        public static CommonCache GetInstance()
        {
            if (_instance == null)
                _instance = new CommonCache();
            return _instance;
        }

        public string GetAllCache()
        {
            var result = new StringBuilder();
            result.Append("[\n");
            foreach (var item in _cache)
            {
                result.Append("  {\n");
                result.AppendFormat($"    \"key\": \"{item.Key}\",\n");
                result.AppendFormat($"    \"value\": \"{item.Value}\",\n");
                result.Append("  },\n");
            }
            result.Append("]\n");
            return result.ToString();
        }

        public bool GetCacheValue(string key, out string value)
        {
            return _cache.TryGetValue(key, out value);
        }

        public void PutCacheValue(string key, string value)
        {
            _cache[key] = value;
        }

        public bool DeleteCacheValue(string key, out string value)
        {
            return _cache.TryRemove(key, out value);
        }

        private readonly ConcurrentDictionary<string, string> _cache = new ConcurrentDictionary<string, string>();
        private static CommonCache _instance;
    }

    class HttpsCacheSession : HttpsSession
    {
        public HttpsCacheSession(NetCoreServer.HttpsServer server) : base(server) { }

        protected override void OnReceivedRequest(HttpRequest request)
        {
            // Show HTTP request content
            Console.WriteLine(request);

            // Process HTTP request methods
            if (request.Method == "HEAD")
                SendResponseAsync(Response.MakeHeadResponse());
            else if (request.Method == "GET")
            {
                string key = request.Url;

                // Decode the key value
                key = Uri.UnescapeDataString(key);
                key = key.Replace("/api/cache", "", StringComparison.InvariantCultureIgnoreCase);
                key = key.Replace("?key=", "", StringComparison.InvariantCultureIgnoreCase);

                if (string.IsNullOrEmpty(key))
                {
                    // Response with all cache values
                    SendResponseAsync(Response.MakeGetResponse(CommonCache.GetInstance().GetAllCache(), "application/json; charset=UTF-8"));
                }
                // Get the cache value by the given key
                else if (CommonCache.GetInstance().GetCacheValue(key, out var value))
                {
                    // Response with the cache value
                    SendResponseAsync(Response.MakeGetResponse(value));
                }
                else
                    SendResponseAsync(Response.MakeErrorResponse("Required cache value was not found for the key: " + key, 404));
            }
            else if ((request.Method == "POST") || (request.Method == "PUT"))
            {
                string key = request.Url;
                string value = request.Body;

                // Decode the key value
                key = Uri.UnescapeDataString(key);
                key = key.Replace("/api/cache", "", StringComparison.InvariantCultureIgnoreCase);
                key = key.Replace("?key=", "", StringComparison.InvariantCultureIgnoreCase);

                // Put the cache value
                CommonCache.GetInstance().PutCacheValue(key, value);

                // Response with the cache value
                SendResponseAsync(Response.MakeOkResponse());
            }
            else if (request.Method == "DELETE")
            {
                string key = request.Url;

                // Decode the key value
                key = Uri.UnescapeDataString(key);
                key = key.Replace("/api/cache", "", StringComparison.InvariantCultureIgnoreCase);
                key = key.Replace("?key=", "", StringComparison.InvariantCultureIgnoreCase);

                // Delete the cache value
                if (CommonCache.GetInstance().DeleteCacheValue(key, out var value))
                {
                    // Response with the cache value
                    SendResponseAsync(Response.MakeGetResponse(value));
                }
                else
                    SendResponseAsync(Response.MakeErrorResponse("Deleted cache value was not found for the key: " + key, 404));
            }
            else if (request.Method == "OPTIONS")
                SendResponseAsync(Response.MakeOptionsResponse());
            else if (request.Method == "TRACE")
                SendResponseAsync(Response.MakeTraceResponse(request.Cache));
            else
                SendResponseAsync(Response.MakeErrorResponse("Unsupported HTTP method: " + request.Method));
        }

        protected override void OnReceivedRequestError(HttpRequest request, string error)
        {
            Console.WriteLine($"Request error: {error}");
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"HTTPS session caught an error: {error}");
        }
    }

    class HttpsCacheServer : NetCoreServer.HttpsServer
    {
        public HttpsCacheServer(SslContext context, IPAddress address, int port) : base(context, address, port) {}

        protected override SslSession CreateSession() { return new HttpsCacheSession(this); }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"HTTPS server caught an error: {error}");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // HTTPS server port
            int port = 8443;
            if (args.Length > 0)
                port = int.Parse(args[0]);
            // HTTPS server content path
            string www = "../../../../../www/api";
            if (args.Length > 1)
                www = args[1];

            Console.WriteLine($"HTTPS server port: {port}");
            Console.WriteLine($"HTTPS server static content path: {www}");
            Console.WriteLine($"HTTPS server website: https://localhost:{port}/api/index.html");

            Console.WriteLine();

            // Create and prepare a new SSL server context
            var context = new SslContext(SslProtocols.Tls12, new X509Certificate2("server.pfx", "qwerty"));

            // Create a new HTTP server
            var server = new HttpsCacheServer(context, IPAddress.Any, port);
            server.AddStaticContent(www, "/api");

            // Start the server
            Console.Write("Server starting...");
            server.Start();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the server or '!' to restart the server...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Restart the server
                if (line == "!")
                {
                    Console.Write("Server restarting...");
                    server.Restart();
                    Console.WriteLine("Done!");
                }
            }

            // Stop the server
            Console.Write("Server stopping...");
            server.Stop();
            Console.WriteLine("Done!");
        }
    }
}

Example: HTTPS client

Here comes the example of the HTTPS client. It allows to send HTTP requests (GET, POST, PUT and DELETE) and receive HTTP responses with secured transport protocol.

using System;
using System.Security.Authentication;
using System.Security.Cryptography.X509Certificates;
using NetCoreServer;

namespace HttpsClient
{
    class Program
    {
        static void Main(string[] args)
        {
            // HTTPS server address
            string address = "127.0.0.1";
            if (args.Length > 0)
                address = args[0];

            // HTTPS server port
            int port = 8443;
            if (args.Length > 1)
                port = int.Parse(args[1]);

            Console.WriteLine($"HTTPS server address: {address}");
            Console.WriteLine($"HTTPS server port: {port}");

            Console.WriteLine();

            // Create and prepare a new SSL client context
            var context = new SslContext(SslProtocols.Tls12, new X509Certificate2("client.pfx", "qwerty"), (sender, certificate, chain, sslPolicyErrors) => true);

            // Create a new HTTPS client
            var client = new HttpsClientEx(context, address, port);

            Console.WriteLine("Press Enter to stop the client or '!' to reconnect the client...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Reconnect the client
                if (line == "!")
                {
                    Console.Write("Client reconnecting...");
                    if (client.IsConnected)
                        client.ReconnectAsync();
                    else
                        client.ConnectAsync();
                    Console.WriteLine("Done!");
                    continue;
                }

                var commands = line.Split(' ');
                if (commands.Length < 2)
                {
                    Console.WriteLine("HTTP method and URL must be entered!");
                    continue;
                }

                if (commands[0].ToUpper() == "HEAD")
                {
                    var response = client.SendHeadRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "GET")
                {
                    var response = client.SendGetRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "POST")
                {
                    if (commands.Length < 3)
                    {
                        Console.WriteLine("HTTP method, URL and body must be entered!");
                        continue;
                    }

                    var response = client.SendPostRequest(commands[1], commands[2]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "PUT")
                {
                    if (commands.Length < 3)
                    {
                        Console.WriteLine("HTTP method, URL and body must be entered!");
                        continue;
                    }

                    var response = client.SendPutRequest(commands[1], commands[2]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "DELETE")
                {
                    var response = client.SendDeleteRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "OPTIONS")
                {
                    var response = client.SendOptionsRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else if (commands[0].ToUpper() == "TRACE")
                {
                    var response = client.SendTraceRequest(commands[1]).Result;
                    Console.WriteLine(response);
                }
                else
                    Console.WriteLine("Unknown HTTP method");
            }

            // Disconnect the client
            Console.Write("Client disconnecting...");
            client.Disconnect();
            Console.WriteLine("Done!");
        }
    }
}

Example: WebSocket chat server

Here comes the example of the WebSocket chat server. It handles multiple WebSocket client sessions and multicast received message from any session to all ones. Also it is possible to send admin message directly from the server.

Use the following link to open WebSocket chat server example: http://localhost:8080/chat/index.html

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using NetCoreServer;

namespace WsChatServer
{
    class ChatSession : WsSession
    {
        public ChatSession(WsServer server) : base(server) { }

        public override void OnWsConnected(HttpRequest request)
        {
            Console.WriteLine($"Chat WebSocket session with Id {Id} connected!");

            // Send invite message
            string message = "Hello from WebSocket chat! Please send a message or '!' to disconnect the client!";
            SendTextAsync(message);
        }

        public override void OnWsDisconnected()
        {
            Console.WriteLine($"Chat WebSocket session with Id {Id} disconnected!");
        }

        public override void OnWsReceived(byte[] buffer, long offset, long size)
        {
            string message = Encoding.UTF8.GetString(buffer, (int)offset, (int)size);
            Console.WriteLine("Incoming: " + message);

            // Multicast message to all connected sessions
            ((WsServer)Server).MulticastText(message);

            // If the buffer starts with '!' the disconnect the current session
            if (message == "!")
                Close(1000);
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat WebSocket session caught an error with code {error}");
        }
    }

    class ChatServer : WsServer
    {
        public ChatServer(IPAddress address, int port) : base(address, port) { }

        protected override TcpSession CreateSession() { return new ChatSession(this); }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat WebSocket server caught an error with code {error}");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // WebSocket server port
            int port = 8080;
            if (args.Length > 0)
                port = int.Parse(args[0]);
            // WebSocket server content path
            string www = "../../../../../www/ws";
            if (args.Length > 1)
                www = args[1];

            Console.WriteLine($"WebSocket server port: {port}");
            Console.WriteLine($"WebSocket server static content path: {www}");
            Console.WriteLine($"WebSocket server website: http://localhost:{port}/chat/index.html");

            Console.WriteLine();

            // Create a new WebSocket server
            var server = new ChatServer(IPAddress.Any, port);
            server.AddStaticContent(www, "/chat");

            // Start the server
            Console.Write("Server starting...");
            server.Start();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the server or '!' to restart the server...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Restart the server
                if (line == "!")
                {
                    Console.Write("Server restarting...");
                    server.Restart();
                    Console.WriteLine("Done!");
                }

                // Multicast admin message to all sessions
                line = "(admin) " + line;
                server.MulticastText(line);
            }

            // Stop the server
            Console.Write("Server stopping...");
            server.Stop();
            Console.WriteLine("Done!");
        }
    }
}

Example: WebSocket chat client

Here comes the example of the WebSocket chat client. It connects to the WebSocket chat server and allows to send message to it and receive new messages.

using System;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using NetCoreServer;

namespace WsChatClient
{
    class ChatClient : WsClient
    {
        public ChatClient(string address, int port) : base(address, port) { }

        public void DisconnectAndStop()
        {
            _stop = true;
            CloseAsync(1000);
            while (IsConnected)
                Thread.Yield();
        }

        public override void OnWsConnecting(HttpRequest request)
        {
            request.SetBegin("GET", "/");
            request.SetHeader("Host", "localhost");
            request.SetHeader("Origin", "http://localhost");
            request.SetHeader("Upgrade", "websocket");
            request.SetHeader("Connection", "Upgrade");
            request.SetHeader("Sec-WebSocket-Key", Convert.ToBase64String(WsNonce));
            request.SetHeader("Sec-WebSocket-Protocol", "chat, superchat");
            request.SetHeader("Sec-WebSocket-Version", "13");
        }

        public override void OnWsConnected(HttpResponse response)
        {
            Console.WriteLine($"Chat WebSocket client connected a new session with Id {Id}");
        }

        public override void OnWsDisconnected()
        {
            Console.WriteLine($"Chat WebSocket client disconnected a session with Id {Id}");
        }

        public override void OnWsReceived(byte[] buffer, long offset, long size)
        {
            Console.WriteLine($"Incoming: {Encoding.UTF8.GetString(buffer, (int)offset, (int)size)}");
        }

        protected override void OnDisconnected()
        {
            base.OnDisconnected();

            Console.WriteLine($"Chat WebSocket client disconnected a session with Id {Id}");

            // Wait for a while...
            Thread.Sleep(1000);

            // Try to connect again
            if (!_stop)
                ConnectAsync();
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat WebSocket client caught an error with code {error}");
        }

        private bool _stop;
    }

    class Program
    {
        static void Main(string[] args)
        {
            // WebSocket server address
            string address = "127.0.0.1";
            if (args.Length > 0)
                address = args[0];

            // WebSocket server port
            int port = 8080;
            if (args.Length > 1)
                port = int.Parse(args[1]);

            Console.WriteLine($"WebSocket server address: {address}");
            Console.WriteLine($"WebSocket server port: {port}");

            Console.WriteLine();

            // Create a new TCP chat client
            var client = new ChatClient(address, port);

            // Connect the client
            Console.Write("Client connecting...");
            client.ConnectAsync();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the client or '!' to reconnect the client...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Disconnect the client
                if (line == "!")
                {
                    Console.Write("Client disconnecting...");
                    client.DisconnectAsync();
                    Console.WriteLine("Done!");
                    continue;
                }

                // Send the entered text to the chat server
                client.SendTextAsync(line);
            }

            // Disconnect the client
            Console.Write("Client disconnecting...");
            client.DisconnectAndStop();
            Console.WriteLine("Done!");
        }
    }
}

Example: WebSocket secure chat server

Here comes the example of the WebSocket secure chat server. It handles multiple WebSocket secure client sessions and multicast received message from any session to all ones. Also it is possible to send admin message directly from the server.

This example is very similar to the WebSocket one except the code that prepares WebSocket secure context and handshake handler.

Use the following link to open WebSocket secure chat server example: https://localhost:8443/chat/index.html

using System;
using System.Net;
using System.Net.Sockets;
using System.Security.Authentication;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using NetCoreServer;

namespace WssChatServer
{
    class ChatSession : WssSession
    {
        public ChatSession(WssServer server) : base(server) { }

        public override void OnWsConnected(HttpRequest request)
        {
            Console.WriteLine($"Chat WebSocket session with Id {Id} connected!");

            // Send invite message
            string message = "Hello from WebSocket chat! Please send a message or '!' to disconnect the client!";
            SendTextAsync(message);
        }

        public override void OnWsDisconnected()
        {
            Console.WriteLine($"Chat WebSocket session with Id {Id} disconnected!");
        }

        public override void OnWsReceived(byte[] buffer, long offset, long size)
        {
            string message = Encoding.UTF8.GetString(buffer, (int)offset, (int)size);
            Console.WriteLine("Incoming: " + message);

            // Multicast message to all connected sessions
            ((WssServer)Server).MulticastText(message);

            // If the buffer starts with '!' the disconnect the current session
            if (message == "!")
                Close(1000);
        }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat WebSocket session caught an error with code {error}");
        }
    }

    class ChatServer : WssServer
    {
        public ChatServer(SslContext context, IPAddress address, int port) : base(context, address, port) { }

        protected override SslSession CreateSession() { return new ChatSession(this); }

        protected override void OnError(SocketError error)
        {
            Console.WriteLine($"Chat WebSocket server caught an error with code {error}");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // WebSocket server port
            int port = 8443;
            if (args.Length > 0)
                port = int.Parse(args[0]);
            // WebSocket server content path
            string www = "../../../../../www/wss";
            if (args.Length > 1)
                www = args[1];

            Console.WriteLine($"WebSocket server port: {port}");
            Console.WriteLine($"WebSocket server static content path: {www}");
            Console.WriteLine($"WebSocket server website: https://localhost:{port}/chat/index.html");

            Console.WriteLine();

            // Create and prepare a new SSL server context
            var context = new SslContext(SslProtocols.Tls12, new X509Certificate2("server.pfx", "qwerty"));

            // Create a new WebSocket server
            var server = new ChatServer(context, IPAddress.Any, port);
            server.AddStaticContent(www, "/chat");

            // Start the server
            Console.Write("Server starting...");
            server.Start();
            Console.WriteLine("Done!");

            Console.WriteLine("Press Enter to stop the server or '!' to restart the server...");

            // Perform text input
            for (;;)
            {
                string line = Console.ReadLine();
                if (string.IsNullOrEmpty(line))
                    break;

                // Restart the server
                if (line == "!")
                {
                    Console.Write("Server restarting...");
                    server.Restart();
                    Console.WriteLine("Done!");
                }

                // Multicast admin message to all sessions
                line = "(admin) " + line;
                server.MulticastText(line);
            }

            // Stop the server
            Console.Write("Server stopping...");
            server.Stop();
            Console.WriteLine("Done!");
        }
    }
}