Question

I have a web app which connects to a server using a TCP connection and reads a binary document which it then writes to its response object. In other words it’s transferring a file from a backend server using a custom protocol and returning that file to its client through HTTP.

The server sends a status code and a mime type, which I read successfully and then writes the contents of the file and closes the socket. This seems to work fine.

The client (a C# web app), reads the data:

     private NetworkStream stream_;       public void WriteDocument(HttpResponse response)      {         while (stream_.DataAvailable)         {            const int bufsize = 4 * 1024;            byte[] buffer = new byte[bufsize];            int nbytes = stream_.Read(buffer, 0, bufsize);            if (nbytes > 0)            {               if (nbytes < bufsize)                  Array.Resize<byte>(ref buffer, nbytes);               response.BinaryWrite(buffer);            }         }         response.End();      } 

This seems to always exit the read loop before all the data has arrived. What am I doing wrong?

Answer 1

I would use the OutputStream directly with a general-purpose function. With the Stream, you can control Flush.

    public void WriteDocument(HttpResponse response) {         StreamCopy(response.OutputStream, stream_);         response.End();     }      public static void StreamCopy(Stream dest, Stream src) {         byte[] buffer = new byte[4 * 1024];         int n = 1;         while (n > 0) {             n = src.Read(buffer, 0, buffer.Length);             dest.Write(buffer, 0, n);         }         dest.Flush();     }