[This message was posted by David Rosenborg of Pantor Engineering AB <[EMAIL PROTECTED]> to the "FAST Protocol" discussion forum at http://fixprotocol.org/discuss/46. You can reply to it on-line at http://fixprotocol.org/discuss/read/273d5170 - PLEASE DO NOT REPLY BY MAIL.]
Dan - I'm not sure I can answer when, but hopefully why: the decoder must know that the TID uses a copy operator before it tries to read it. So it cannot be a property of the template itself and must therefore be mandatory. However, an encoder is free to not utilize the operator and always set the first bit in the pmap and include the TID in every message. /David > Rolf, I do not recall that it was mandatory to use copy encoding on the > TID. I know I used an encoding of "NONE" in the ARCA implementation for > the tid (which was called MSG_TYPE in those days). Do you recall why or > when copy encoding on the tid was made mandatory ? I recall ARCA liked > the idea if having a predictable MSG_TYPE. > > As far as David Hait, I think I see the confusion between what he is > saying, at what actually is going on. If he is referring to our FASTOR > templates, they are not “self describing” as he says, but the > encoder and decoder sample code based on fastapi 1.0 may give that > impression. > > Daniel > > > > David, > > > > pmap slot allocation is local to a specific template. each message > > identifies which template to use in decoding. > > > > the following rules apply for a FAST encoded stream: > > - each message begins with a pmap. > > - the first field (following the pmap) is a tid (template id). > > - the tid uses copy coding. > > - the first slot in the message level pmap is used for the tid. > > > > otherwise the format is not FAST compliant. > > > > /Rolf [You can unsubscribe from this discussion group by sending a message to mailto:[EMAIL PROTECTED] --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Financial Information eXchange" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/FIX-Protocol?hl=en -~----------~----~----~----~------~----~------~--~---
