[This message was posted by Rolf Andersson of Pantor Engineering <[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/2f58fc65 - PLEASE DO NOT REPLY BY MAIL.]
IIRC, the TID in the ARCA feed had a pmap bit allocated although it was specified to have the operator NONE. > 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 -~----------~----~----~----~------~----~------~--~---
