Sending data questions

Jeffrey · 2012-06-15T19:20:35

Hey guys, I have a question about sending data in UDP. For example i have this structure : [source] structure NetworkPacket { char *m_data; int m_id; }; [/source] And i fill it like this : [source] SomeStructure l_data; ... NetworkPacket l_packet; l_packet.m_data = (char*)(&l_data); l_packet.m_id = 1; [/source] And send it / receive it like this [source] sendto(socket, (char*)(&l_packet), sizeof(NetworkPacket), 0, (sockaddr*)&address, sizeof(sockaddr)); NetworkPacket l_packet; auto l_bytes_received = 0; l_bytes_received = recvfrom(socket, (char*)(&l_packet), sizeof(NetworkPacket), 0, (sockaddr*)&l_incomingAddress, &l_size) [/source] Is it true that this will fail because in the structure NetworkPacket the char * is dynamic so it's size isn't known in the structure declaration? Also i had an idea about solving it if the above is true. What about just sending a packet with the size of the packet that will come next in it? But this will fail if the packets got reordered somewhere. Does that happen often in UDP? If so then this design isn't really good, and if it doesn't should i just ignore that and send the packets again that where lost? Thanks in advance.

Networking and Multiplayer Programming

Started by jeffreyp23 June 14, 2012 08:59 AM

10 comments, last by jeffreyp23 11 years, 10 months ago

dpadam450

2,403

June 15, 2012 06:10 PM

To the OP: what I meant was:
To do this create a char Buffer[1000];
int offset = 0;
memcpy(&(Buffer[offset]), l_data.m_data, ...sizeof(YOUR_M_DATA));
offset += sizeof(YOUR_M_DATA);
memcpy(&(Buffer[offset]), &l_data.m_id, 4);//integer is 4 bytes

Basically you have to copy what is actually in the pointer itself was what I was getting at.

NBA2K, Madden, Maneater, Killing Floor, Sims http://www.pawlowskipinball.com/pinballeternal

jeffreyp23

178

Author

June 15, 2012 07:20 PM

Thanks for all the advice : ). I already got something up and running with memcpy.
I also found something else(what hplus mentioned) here : http://stackoverflow...nd-over-network (scroll down a bit for the code). Would this be a better solution?
Also i couldn't find to much information about

[background=rgb(250, 251, 252)]serialization(found 1 tutorial).[/background]

[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif][background=rgb(250, 251, 252)]If anybody got some useful links post them : )[/background][/font]

Sending data questions

[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif][background=rgb(250, 251, 252)]If anybody got some useful links post them : )[/background][/font]

[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif][background=rgb(250, 251, 252)]Thanks[/background][/font]

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Sending data questions

[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif][background=rgb(250, 251, 252)]If anybody got some useful links post them : )[/background][/font]

[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif][background=rgb(250, 251, 252)]Thanks[/background][/font]

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines