[VibeD] Hand made proxy

[nazriel]

Greetings.

I am trying to learn Vibe.D and rewrite using it, my old project 
I've wrote with my (already rotting) personal framework

Project been written as commercial project for one of my clients 
so I can't really release source code here, but in tl;dr it is:

Proxy that gets file from remote server (process of getting file 
itself is rather complicated) and then serves it to the connected 
client.

In my old project I used threads because there are no more than 
15 clients connected same time. There was main thread listening 
for connections, and 15 worker threads that were making bridge 
between client and remote server.

Now I tried few different approaches with Vibe.d but all had some 
issues.
The far I could get was this:
http://dpaste.dzfl.pl/d4dabd0a [1]

But it still has some issues. It works great for small files but 
for larger
(~150MB) VibeD just closes remote connection and web browsers 
just keep trying to receive something until it timeouts.

Another issue which will probably come is the fact that Vibe.D 
won't be able to serve more than 1 client at the same time. At 
least my attempts with 2MB file resulted with: 1st client 
downloading file, 2nd client getting 500 from vibe.d

Question is then: How to properly handle it with VibeD? How do 
you handle more threads with VibeD?

Aha, and please don't get into details like "your buffer is too 
small" etc. It isn't important at this stage.

Thanks in advance!

[1]

----
import vibe.d;

import std.stdio;


void handle(HTTPServerRequest, HTTPServerResponse res)
{
     string link = "http://yourdomain.com/file_here";

     requestHTTP(link, null,
         (scope HTTPClientResponse r)
         {
             enum BUFF_SIZE = 1024;
             ubyte[BUFF_SIZE] buff;
             ulong last_read = 0;

             res.headers = r.headers;
             res.headers["Content-Disposition"] = `attachment; 
filename="fname.gz"`;

             while (r.bodyReader().empty == false)
             {
                 last_read = r.bodyReader().leastSize;
                 if (last_read > BUFF_SIZE)
                     r.bodyReader().read(buff);
                 else
                     r.bodyReader().read(buff[0..last_read]);

                 res.bodyWriter.write(buff[0..(last_read > 
BUFF_SIZE ? 1024 : last_read)]);

                 if (last_read < BUFF_SIZE)
                 {
                     break;
                 }
             }
         }
     );
}

static this()
{
     setLogLevel(LogLevel.trace);

     auto settings = new HTTPServerSettings;
     settings.hostName = "localhost";
     settings.port = 8004;
     settings.bindAddresses = ["127.0.0.1"];

     auto router = new URLRouter;
     router.get("/download/*", toDelegate(&handle));

     listenHTTP(settings, router);
}
---