Re: TCP/IP Sockets with GNAT.Sockets

["fabio de francesco" <fmdf@tiscali.it>]

Adrien Plisson wrote:

> fabio de francesco wrote:
> > How can you know a priori if a remote service is coded in C or Ada
or
> > everything else?

> you don't and you should NEVER assume such a thing. but you should
know
> what protocol is to be used between the client and the server. if the

> protocol is well-defined (that is: in a language independant way)
there
> is no problem in making any software in any language communicate...

Ciao,

I know that. I've been programming networking software in C for years.

I only objected to that statement: "... however If the other end of the
socket is a C-style server it will probely demand somthing like the
following:..."

> > Is your code reading character by character? If it is I don't think
you
> > can use it for designing efficient programs.

> why not ?

I supposed that Ada and C aren't different in that. I mean that, when a
C program is to read/write a lot of data from/to a disk file or any
other device, it is preferred to read/write large chunks of bytes
altogether:

    FILE *in, *out;
    size_t nread;
    char buffer[BUFSIZ];

    in = fopen ("file.in", "r");
    out = fopen ("file.out", "w");

    while ((nread = fread(buffer,sizeof(char),sizeof(buffer),in)) > 0)
        fwrite(buffer,sizeof(char),nread,out);

    fclose (in);
    fclose (out);

The first code is faster (20% on my machine) than the following:

 char b;
 while ((nread = fread(&b,sizeof(char),1,in)) > 0)
     fwrite(&b,sizeof(char),1,out);

> another question for you: do you use TCP connections to send small
> packets ? those TCP frames that can achieve more than 50% overhead
are
> really not efficient...

What does make you think that? If you refer to my posted code, it was
only a test to get acquainted to GNAT.Sockets.

> > May be your C-counterpart program
> > contains an algorithm that knows how to do it.
>
> or simply ignore those characters which are non-printable, which is
the
> case with small strings...
> 
> -- 
> rien

Regards,

fabio de francesco