问C#异步TCP套接字:处理缓冲区大小和大量传输

EN

// In this example I used a Socket wrapped inside a NetworkStream for simplicity
// stability, and asynchronous operability purposes.

// This can be done by doing this:
//
//  For server:
//
//  Socket server= new Socket();
//  server.ReceiveBufferSize = 18000;
//  IPEndPoint iPEndPoint = new IPEndPoint(IPAddress.Any, port);
//  server.Bind(iPEndPoint);
//  server.Listen(3000);
// 
// 
//  NetworkStream ns = new NetworkStream(server);

//  For client:
//  
//  Socket client= new Socket();
//  client.Connect("127.0.0.1", 80);
//  
//  NetworkStream ns = new NetworkStream(client);

// In order to set an objective buffer size based on a file's size in order not to
// receive null characters as extra characters because the buffer is bigger than
// the file's size, or a corrupted file because the buffer is smaller than
// the file's size.

//   The TCP protocol follows the Sys, Ack and Syn-Ack paradigm,  
//   so within a TCP connection if the client or server began the 
//   connection by sending a message, the next message within its
//   connection must be read, and if the client or server began 
//   the connection by receiving a message, the next message must
//   be sent.

// [SENDER]

byte[] file = new byte[18032];

byte[] file_length = Encoding.UTF8.GetBytes(file.Length.ToString());

await Sender.WriteAsync(file_length, 0, file_length.Length);

byte[] receiver_response = new byte[1800];

await Sender.ReadAsync(receiver_response, 0, receiver_response.Length);

await Sender.WriteAsync(file, 0, file.Length);

// [SENDER]

// [RECEIVER]

byte[] file_length = new byte[1800];

await Receiver.ReadAsync(file_length, 0, file_length.Length);

byte[] encoded_response = Encoding.UTF8.GetBytes("OK");

await Receiver.WriteAsync(encoded_response, 0, encoded_response.Length);

byte[] file = new byte[Convert.ToInt32(Encoding.UTF8.GetString(file_length))];

await Receiver.ReadAsync(file, 0, file.Length);

// [RECEIVER]

// In this example I used a Socket wrapped inside a NetworkStream for simplicity
// stability, and asynchronous operability purposes.

// This can be done by doing this:
//
//  For server:
//
//  Socket server= new Socket();
//  server.ReceiveBufferSize = 18000;
//  IPEndPoint iPEndPoint = new IPEndPoint(IPAddress.Any, port);
//  server.Bind(iPEndPoint);
//  server.Listen(3000);
// 
//  NetworkStream ns = new NetworkStream(server);

//  For client:
//  
//  Socket client= new Socket();
//  client.Connect("127.0.0.1", 80);
//
//  NetworkStream ns = new NetworkStream(client);

    class Internet_Speed_Checker
    {
        public async Task<bool>> Optimum_Buffer_Size(System.Net.Sockets.NetworkStream socket)
        {
             System.Diagnostics.Stopwatch latency_counter = new System.Diagnostics.Stopwatch();

             byte[] test_payload = new byte[2048];

             //   The TCP protocol follows the Sys, Ack and Syn-Ack paradigm,  
             //   so within a TCP connection if the client or server began the 
             //   connection by sending a message, the next message within its
             //   connection must be read, and if the client or server began 
             //   the connection by receiving a message, the next message must
             //   be sent.
             //
             //   In order to test the connection, the client and server must 
             //   send and receive a package of the same size. If the client 
             //   or server began the connection by sending a message, the 
             //   client or server must do the this connection test by 
             //   initiating a write-read sequence, else it must do this
             //   connection test initiating a read-write sequence.

             latency_counter .Start();

             await client_secure_network_stream.ReadAsync(test_payload, 0, test_payload.Length);

             
             
             await client_secure_network_stream.WriteAsync(test_payload, 0, test_payload.Length);

             latency_counter .Stop();
             
             int bytes_per_second = (int)(test_payload.Length * (1000 / latency_time_counter.Elapsed.TotalMilliseconds));

             int optimal_connection_timeout = (Convert.ToInt32(payload_length) / download_bytes_per_second) * 1000 + 1000;

             double optimal_buffer_size_double = ((download_bytes_per_second / 125000) * (latency_time_counter.Elapsed.TotalMilliseconds / 1000)) * 1048576;

             int optimal_buffer_size = (int)download_optimal_buffer_size_double + 1024;
             
             // If you want to upload data to the client/server -->  client.SendBufferSize = optimal_buffer_size;
             // client.SendTimeout = optimal_connection_timeout;
             
             // If you want to download data from the client/server -->  client.ReceiveBufferSize = optimal_buffer_size;
             // client.ReceiveTimeout = optimal_connection_timeout;
        }
    }