[ENet-discuss] Announcing QENet - a Qt Wrapper for ENet

[Nathan Osman]

On Wed, Oct 24, 2012 at 3:21 AM, Thorbjørn Lindeijer <bjorn at lindeijer.nl>wrote:

> On Wed, Oct 24, 2012 at 10:13 AM, Stefan Lundmark <stefanlun at hotmail.com>
> wrote:
> > Exposing the sleep amount time might be a good idea considering 200 ms
> makes
> > it totally useless for anything that needs to run in real-time, like
> games.
>

Yes, I have become convinced that exposing the number is a good idea.
Therefore I have added a new parameter to the end of QENetHost::create().

Also, since the data is passed as a QByteArray signal parameter, this
> necessitates creating a copy of the data. To avoid this
> QByteArray::fromRawData could be used, but that's somewhat dangerous
> for a library to do since this would make it illegal for the
> QENetPacket (or its data) to be stored for later use unless an
> explicit copy is made of its data while it is still allocated (since
> it would be comparable to simply storing the char * and length
> provided by enet).
>

Right - I originally was just storing the ENetPacket * itself in
QENetPacket and discovered (with the help of the debugger) that ENet
automatically frees packets once they are sent. So instead I decided it
would be easier to just copy the packet's contents immediately upon receipt
and go from there. I'm pretty sure QByteArray uses copy-on-write and
therefore passing a QByteArray around by value won't result in a bunch of
data copying operations.

As for the automatic host service timer, maybe the library should just
> expose a 'service' method (slot) so that the application using the
> library can hook up a timer of its own at whatever desired frequency.
>

I have no idea why I didn't think of this myself. Thank you! I have created
a slot QENetHost::service() that can be called at any time to service the
host or attached to another QTimer, etc. You can disable QENetHost's
built-in timer by passing a value of 0 as the final parameter to create() -
you will then need to make sure your code calls QENetHost::service() at
regular intervals (such as in a game's main loop).


> I do think ENet is rather simple to use directly so for me personally
> such a library is not adding much. For my own purposes I wrote this
> ENetClient class, which is meant to be subclassed in order to
> implement different clients and has some protocol helpers used by the
> Mana client and server built into it (MessageIn and MessageOut) as
> well as using QHostInfo for non-blocking host lookup (I couldn't find
> a way to have enet do this in a non-blocking way).
>
> https://github.com/mana/manamobile/blob/master/src/mana/enetclient.cpp


 Cool! I hadn't realized anyone else had done a Qt wrapper for ENet.

- Nathan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.cubik.org/pipermail/enet-discuss/attachments/20121024/7b33d589/attachment.html>