libCxClient - Citadel/UX Extensible Client API
Copyright (c) 2000, Flaming Sword Productions
Copyright (c) 2001, The Citadel/UX Consortium
All Rights Reserved

http://www.shadowcom.net/Software/libCxClient/
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Miscellaneous Notes
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These are some notes which were involved in the development of the asynchronous
(ASYN) protocol on Citadel/UX.  As I recall, these statements were made by
Art J. Cancro, Master of Citadel/UX.  It all makes sense to me, though! :)

Ok, I'm making a decision.  Here is the protocol.
 
 At any time between commands, or between the time a client enters a command
and the reply from that command is generated, the server MAY spit out a
900 series message.  This is an asynchronous message and the client MUST
process it immediately.
 
 A 900 series message will always be followed by a 100, 200, 300, 400, 500,
600, or 700 series message which carries the data of the asynchronous
message.
 
 I like most of dT's codes, and we'll probably go with something like that.
I think the actual data of the message should be in the second line rather
than in the 900 message, though.  For example, if 901 means "express message
arriving" then...
 
 
901 xmsg follows:
100 0|979362858|0|IGnatius T Foobar|uncnsrd
This is the text,
 of the message that is being received,
  and it is really cool.
>000
 
 
 The benefit of this, in the example above, is that the output is exactly
the same as the output of the GEXP command.  Opportunities for code sharing
abound.
 
 
 If the client had already sent a command, and it got the 901, it would have
to handle the 901 and its data transfer first, putting it in a queue if
necessary, and then receive the output of the command it sent (unless it gets
another 900 first, in which case it keeps running the appropriate handlers
until it gets something other than a 900).
 
 
 After thinking about it all day, this is the way I'd like to go unless dT
has a problem with it.

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