C++ / Socket design help

[tntcoder]

Hi,

Im using this sockets library with C++ http://www.alhem.net/Sockets/tutorial/using1a.html

This works in non-blocking event based style mode. So if i do the following:

mysockclass->Send("command1\r\n");
mysockclass->Send("command2\r\n");
mysockclass->Send("command3\r\n");

Then as a result the OnRead() method of mysockclass gets called 3 times whenever a response is sent back from the server.

This asynchronous design is all very nice, but im a little stuck as to how i process the response when it comes in.

Say when i send "command1" i need to process the response in OnRead() with specific regards to what was sent.

So if i send "command1" and the server sends back a string which OnRead() processes how can i tell it was from command1? (there is nothing specific in the server response that can tell me this).

With blocking sockets, i would do something like this:

Send(string1)
recv() // I would know what to expect in here
send(string2)
recv() // Again i would know what to expect
...

But how is this approach handled in an asynchronous design?

One idea i did have was having some kind of flag that would signal what i expect to receive and process the data according to that flag.

Thanks for any advice.

Jack

 

[tntcoder]

Thanks for the help guys i think that makes sense, i phraphs should have provided more server info.

The server is an NNTP server, which does send a 3 digit identification code i can use at the start of each response, however some responses exceed the buffer size of 1 read event, so the second/thrird/etc read from the socket is a remaining chunk of the first one with no form of ID i can use.

Increasing the buffer size wont help because i never know how many bytes will be sent in the response.

So if do:
mysockclass->Send("list\r\n");

I get a big response, which will cause several OnRead events to be raised. And because its async i would imagine i could get responses from another send command jumbled up in there, or will they all be read in the order they were sent?

So how would i approach 'joining' together multiple socket reads which really are all 1 response?

Thanks again and sorry if that doesn't make sense

Jack