trache

I'm just testing the waters here, as I know Delphi isn't exactly as widespread as C/C++, but I do have a problem that perhaps someone could help me solve.

I'm trying to write a simple client/server pair of applications that when I send information to and fro, send a simple length of string and then the actual sting itself over the socket.

Since Internet Component Suite/ICS/TWSocket is event-driven, and works by triggering an OnDataAvailable event when Data is actually available (ie you cannot force the component to read, it will do it automatically when it finds any data on the socket, read it, and fire an event), you must act on the data when you receive it (which could be any time).

The trouble for me comes when trying to implement a binary-type protocol such as this and not when using an ASCII type protocol like IRC, POP3, SMTP, NNTP simply because those protocols work with lines of strings each with terminators (such as CR/LFs). When using ICS, this is simple: the component reads a line until it finds a CR/LF, it fires an OnDataAvailable event, and you receive an entire line (most times including the CR/LF).

Done and done, but not with protocols like Napster, ICQ, or AIM wherein they tell you how much data they are sending and its your job to receive it. With TWSocket, it fires when data is available, and you cannot force it (to the best of my knowledge).

So you could read it say into a buffer and start processing information when the buffer is full, but then what happens if your information is cut in two (the rest coming in the next OnDataAvailable call)? My solution is either a full buffer, or read it in until a terminator is found (which is essentially what ICS does by default with ASCII protocols and its LineMode property), which obviously isn't how my protocol is supposed to work.

I'd like to do this, preferrably (not a requirement, though) with TWSocket as I'm familiar with it.

So, does anyone have any idea what I'm talking about? I hope I'm not the only Delphi enthusiast here. :-) Can someone give me some insight?

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bendsley

should be moved to programming

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"You hear the one about the fella who died, went to the pearly gates? St. Peter let him in. Sees a guy in a suit making a closing argument. Says, "Who's that?" St. Peter says, "Oh, that's God. Thinks he's Denny Crane."