• Marcone (13/13) Feb 03 2021 I study Dlang for just over a year only and have already risked
• =?UTF-8?Q?Ali_=c3=87ehreli?= (22/26) Feb 04 2021 I don't know the protocol but obviously 8192 must be sufficient.
• Max Haughton (3/9) Feb 04 2021 Less calls to std.conv can also mean less surface area for

Marcone <marcone email.com> writes:

I study Dlang for just over a year only and have already risked 
creating a program even with a graphical interface and distribute 
it on the internet. Here is a part of that program, just the code 
without a graphical interface. It is a program for modifying http 
headers. You connect your program to the local port of this 
script, this script plays the role of a server to receive your 
program. Receive the HTTP request from the program, connect to 
the remote server playing a client role, modify the HTTP request 
from the program and connect to the remote server.


I would like the completely relevant opinion of you my programmer 
friends in Dlang if my code is good or if it is very noob.

My Code: 
https://github.com/cerejavermelha/Dlang-Client-Server-Socket-Dropbear-Injector/blob/master/Dlang_Client_Server_Socket_Dropbear_Injector.d

=?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:

On 2/3/21 8:44 AM, Marcone wrote:
 relevant opinion

I think the following would be improvements:

    char[8192] request;

I don't know the protocol but obviously 8192 must be sufficient.

    auto rq = c.receive(request);

So, what is actually received is request[0..rq]. I would call the first 
one 'buffer' and the actual part 'request':

   char[8192] buffer;
   const length = c.receive(buffer);
   enforce (length != Socket.ERROR, "Failed to read from socket.");
   auto request = buffer[0 .. length];

Each to!string is an extra copy below (and more in your code):

    string host = 

to!string(request)[to!string(request).indexOf("CONNECT")+7..to!string(request).indexOf(":")].strip();

I would make a variable first (you can find better variable names :) ):

   string str = to!string(request);
   const conn = str.indexOf("CONNECT") + 7;
   const colon = str.indexOf(":");
   const http = str.indexOf("HTTP/");

   string host = str[conn .. colon].strip();
   string port = str[colon + 1 .. http].strip();

Even though performance of multiple to!string calls is not detectable in 
this program that interacts with sockets, I still think reducing the 
calls to to!string helps with readability and is less error-prone. :)

Ali

Max Haughton <maxhaton gmail.com> writes:

On Thursday, 4 February 2021 at 20:54:15 UTC, Ali Çehreli wrote:
 On 2/3/21 8:44 AM, Marcone wrote:
 [...]

 I think the following would be improvements:

    [...]

 I don't know the protocol but obviously 8192 must be sufficient.

 [...]

Less calls to std.conv can also mean less surface area for 
exceptions to throw from