I'd kicked around the idea of using some sort of required "cmd" field as
the first field in the struct being sent, my only concern is what
happens to the rest of the "trash" data after first memcpy. E.g.,
StructA and StructB, StructB is bigger than StructA, both have the first
field as a "char cmd", but the rest of the data causes the structs to
not be the same size. If I send a StructB but memcpy the incoming binary
data into a StructA to check the command type, is it safe to then
re-memcpy this incoming data back into a StructB once I've figured out
the command type? Or is there weird memory stuff that happens (I would
assume not as the incoming data will always be the same, we can copy
that to whomever we wish at will)?
Also, a packet class wrapper sounds like a great idea! Thanks for the
suggestions.
On 1/17/2010 3:06 PM, Ruud van Gaal wrote:
I use a packet class where I can just add bytes& shorts& ints (and
strings) to a packet. So you just:
enum Cmd
{
CMD_CAR_UPDATE,
CMD_CHAT,
...
};
pkt=new Packet();
pkt->AddChar(CMD_CAR_UPDATE);
pkt->AddFloat(carX);
...
and later at the receiving end:
cmd=pkt->GetChar();
if(cmd==...){ ... }
Although a struct where all things start with 'char cmd' can also do nicely.
Learn more about pointers and dereferencing them in C/C++.
Cheers,
Ruud
-----Oorspronkelijk bericht-----
Van: [email protected]
[mailto:[email protected]] Namens Alex Milstead
Verzonden: Sunday, January 17, 2010 20:54
Aan: Discussion of the ENet library
Onderwerp: Re: [ENet-discuss] A query about channels
In that case, is there a solid way to extract that
identifier? Or will I need to do some I'm aware of sprintf
calls, is it common practice to simply "sprintf" the first
integer of the received binary data into a buffer and
(effectively) switch-case on that buffer, then memcpy the
remaining data that follows? Or is there a better way of doing this?
Cheers,
Alex
On Jan 17, 2010, at 2:39 PM, Thorbjørn Lindeijer
<[email protected]>
wrote:
On Sun, Jan 17, 2010 at 19:50, Alex Milstead
<[email protected]> wrote:
Also, Jay you mentioned earlier that it was easy to do
simple data-
type
checking on the receiving end. I'm a bit of a fledgling network
programmer
-- I'm still definitely becoming more acquainted the vast amount of
unfamiliar programming techniques in this particular
arena. The only
surefire type-checking system I know about in programming is in
java (=/),
with it's "instanceof" operator. As far as I know this type of
mechanism, or
anything similar, doesn't really exist in C/C++. So my next
question is, if
we're sending binary data along and receiving it as binary data,
what's the
most efficient way of type-checking the probable struct
being piped
through?
You give it a number which designates its type. You'd
usually prepend
such a number to each of your messages, so that you know how to
interpret them on the other end.
Regards,
Bjørn
_______________________________________________
ENet-discuss mailing list
[email protected]
http://lists.cubik.org/mailman/listinfo/enet-discuss
_______________________________________________
ENet-discuss mailing list
[email protected]
http://lists.cubik.org/mailman/listinfo/enet-discuss
_______________________________________________
ENet-discuss mailing list
[email protected]
http://lists.cubik.org/mailman/listinfo/enet-discuss
_______________________________________________
ENet-discuss mailing list
[email protected]
http://lists.cubik.org/mailman/listinfo/enet-discuss
