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FAST Protocol
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Re: Fast SCP
Jean-Marie Sulmont / RTS <>
1 Aug 2008 1:40AM ETMay be we could create a special relation between templates -- like "Russian nesting dolls", or template inheritance.
If template T3 <-- T2 <-- T1
then if message M3 has been T3-encoded, it then can be decoded by T2 and or T1.
What you get when you decode M3 following T2 or T1 is not specified.
That would solve Hanno's problem. That would also allow the notion of template specialization etc.
What do you think???
> Hanno,
>
> There is no way to know how long the message is without the correct
> template, so a new message with an unknown or 'extended' template can't
> be fully decoded (a result of the decision to not include a message
> length in FAST or SCP).
>
> Perhaps an optional length for messages requiring a new template would
> maintain the integrity of the transport layer without affecting the
> message contents.
>
> Then you could create a revised template (instead of 7 it would 7.1?)
> that could have additional fields that would be ignored until you get a
> hold of the new template.
>
> Greg.
>
> > Hanno, this is an interesting problem.
> >
> > The short answer is no. There is no way for the receiver to detect
> > that there is another field in the message. As you mention, you could
> > put a placeholder into the template, maybe an optional field at the
> > end of the template. This would maybe work in some instances, but you
> > would be restricted in choice of operator etc.
> >
> > We did discuss this some when we were updating the spec from 1.0 to
> > 1.1, but nothing came out of that discussion if I recall correctly.
> >
> > It's worth discussing again, though. Anyone has ideas on this?
> >
> > /Rolf
> >
> > > Rolf,
> > >
> > > I have a related question. Is there a way to send a new message
> > > without having sent a new template definition, i.e. if I add a
> > > field to my message, is there a way for the receiver to ignore that
> > > new field until he receives a new template definition from me,
> > > perhaps by appending it to the end of my message and having a
> > > placeholder in my initial template definition? Or is it a strict
> > > requirement to always send a new template definition prior to
> > > sending a message for it.
> > >
> > > Thanks, Hanno.
Fast SCP Dimitry London / Morgan Stanley 30 Jul 2008 10:16PM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 31 Jul 2008 3:28AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 31 Jul 2008 6:17AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 31 Jul 2008 9:05AM ET Re: Fast SCP Hanno Klein / Deutsche Börse Systems 31 Jul 2008 10:06AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 31 Jul 2008 10:15AM ET Re: Fast SCP Greg Orsini / Cameron Systems 31 Jul 2008 11:44AM ET Re: Fast SCP
Jean-Marie Sulmont / RTS 1 Aug 2008 1:40AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 2:06AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 2:39AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 3:13AM ET Re: Fast SCP Hanno Klein / Deutsche Börse Systems 1 Aug 2008 3:33AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 3:57AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 4:10AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 3:06AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 1 Aug 2008 6:28AM ET Re: Fast SCP Jacob Northey / The LaSalle Technology Group 1 Aug 2008 8:21AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 1 Aug 2008 9:33AM ET Re: Fast SCP Greg Orsini / Cameron Systems 1 Aug 2008 10:01AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 1 Aug 2008 10:16AM ET Re: Fast SCP Greg Orsini / Orc Software w/CameronFIX 1 Aug 2008 10:32AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 1 Aug 2008 10:58AM ET Re: Fast SCP Jean-Marie Sulmont / RTS 31 Jul 2008 10:19AM ET Re: Fast SCP Jean-Marie Sulmont / RTS 31 Jul 2008 10:41AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 31 Jul 2008 11:10AM ET Re: Fast SCP Dimitry London / Morgan Stanley 7 Aug 2008 10:53PM ET
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