C# Socket.send 很慢

Question

我正在使用 Socket class 将字节数组中的图像数据发送到同一台 PC 上的第三方程序运行（所以我不用担心关于连接问题）。由于我的应用程序非常简单，所以我只使用同步 send(bytes) 函数，仅此而已。问题是，它运行得很慢。如果我发送一张 20kB 的小图片，需要将近 15ms，但如果图片足够大 - 1.5mB，则需要将近 800ms，这对我来说是无法接受的。如何提高套接字性能？

Socket sender = new Socket(AddressFamily.InterNetwork,SocketType.Stream, ProtocolType.Tcp);
IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
IPAddress ipAddress = ipHostInfo.AddressList[0];
IPEndPoint remoteEP = new IPEndPoint(ipAddress, 3998);
sender.Connect(remoteEP);

byte[] imgBytes;
MemoryStream ms = new MemoryStream();
Image img = Image.FromFile("С:\img.bmp");
img.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
imgBytes = ms.ToArray();
/*Some byte operations there: adding headers, file description and other stuff.
They are really fast and add just 10-30 bytes to array, so I don't post them*/

DateTime baseDate = DateTime.Now; // Countdown start

for (uint i = 0; i < 100; i++) sender.Send(byteMsg);

TimeSpan diff = DateTime.Now - baseDate; 
Debug.Print("End: " + diff.TotalMilliseconds);
// 77561 for 1.42mB image, 20209 for 365kb, 1036 for 22kB.

Answer 1

这可能是将一个大文件读取到内存流，将其复制到一个数组，然后重新分配该数组以在其前面加上一些数据，这实际上会影响性能，而不是 Socket.send()。

尝试使用流到流的复制方法：

        Socket sender = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
        IPAddress ipAddress = ipHostInfo.AddressList[0];
        IPEndPoint remoteEP = new IPEndPoint(ipAddress, 3998);
        sender.Connect(remoteEP);
        using (var networkStream = new NetworkStream(sender))
        {
            // Some byte operations there: adding headers, file description and other stuff.
            // These should sent here by virtue of writing bytes (array) to the networkStream

            // Then send your file
            using (var fileStream = File.Open(@"С:\img.bmp", FileMode.Open))
            {
                // .NET 4.0+
                fileStream.CopyTo(networkStream);

                // older .NET versions
                /*
                byte[] buffer = new byte[4096];
                int read;
                while ((read = fileStream.Read(buffer, 0, buffer.Length)) > 0)
                    networkStream.Write(buffer, 0, read);
                */
            }
        }

Answer 2

问题出在另一边。我正在使用 Microsoft 的 CCV socket modification as a server and it seems, this programm makes lots of operations even while receiving a picture. I've tried my code from question with test server app (Synchronous Server Socket Example 并从中删除了字符串分析），因为这一切都开始快了近 100 倍。

C# Socket.send 很慢

C# Socket.send is very slow

c#

sockets

performance

bytearray