Question

Im writing an Server/Client Application which works with SSL(over SSLStream), which has to do many things(not only file receiving/sending). Currently, It works so: Theres only one connection. I always send the data from the client/server using SSLStream.WriteLine() and receive it using SSLStream.ReadLine(), because I can send all informations over one connection and I can send from all threads without destroying the data.

Now I wanted to implement the file sending and receiving. Like other things in my client/server apps, every message has a prefix (like cl_files or sth) and a base64 encoded content part(prefix and content are seperated by |). I implemented the file sharing like that: The uploader send to the receiver a message about the total file size and after that the uploader sends the base64 encoded parts of the file over the prefix r.

My problem is that the file sharing is really slow. I got around 20KB/s from localhost to localhost. I have also another problem. If I increase the size of the base64 encoded parts of the file(which makes file sharing faster), the prefix r doesnt go out to the receiver anymore(so the datas couldnt be identified).

How can I make it faster?

Any help will be greatly appreciated.

My(propably bad) code is for the client:

//its running inside a Thread
FileInfo x = new FileInfo(ThreadInfos.Path);
long size = x.Length; //gets total size
long cursize = 0;
FileStream fs = new FileStream(ThreadInfos.Path, FileMode.Open);
Int16 readblocks = default(Int16);
while (cursize < size) {
    byte[] buffer = new byte[4096];
    readblocks = fs.Read(buffer, 0, 4096);
    ServerConnector.send("r", getBase64FromBytes(buffer));//It sends the encoded Data with the prefix r over SSLStream.WriteLine
    cursize = cursize + Convert.ToInt64(readblocks);
    ThreadInfos.wait.setvalue((csize / size) * 100);//outputs value to the gui
}
fs.Close();

For the Server:

case "r"://switch case for prefixes
           if (isreceiving)
           {
              byte[] buffer = getBytesFromBase64(splited[1]);//splited ist the received Line over ReadLine splitted by the seperator "|"
              rsize = rsize + buffer.LongLength;
              writer.Write(buffer, 0, buffer.Length);//it writes the decoded data into the file
              if (rsize == rtotalsize)//checks if file is completed
              {
                 writer.Close();
              }
           }
break;

Answer 1

Your problem stems from the fact that you are performing what is essentially a binary operation through a text protocol and you are exacerbating that problem by doing it over an encrypted channel. I’m not going to re-invent this for you, but here are some options…

1. Consider converting to an HTTPS client/server model instead of reinventing the wheel. This will give you a well-defined model for PUT/GET operations on files.

2. If you can not (or will not) convert to HTTPS, consider other client/server libraries that provide a secure transport and well-defined protocol for binary data. For example, I often use protobuf-csharp-port and protobuf-csharp-rpc to provide a secure protocol and transport within our datacenter or local network.

3. If you are stuck with your transport being a raw SslStream, try using a well-defined and proven binary serialization framework like protobuf-csharp-port or protobuf-net to define your protocol.

4. Lastly, if you must continue with the framework you have, try some http-like tricks. Write a name/value pair as text that defines the raw-binary content that follows.