- From: Williams, Stuart <skw@hplb.hpl.hp.com>
- Date: Fri, 9 Feb 2001 18:29:00 -0000
- To: "'Henrik Frystyk Nielsen'" <frystyk@microsoft.com>, "Williams, Stuart" <skw@hplb.hpl.hp.com>, "Jean-Jacques Moreau (E-mail)" <moreau@crf.canon.fr>, "John Ibbotson (E-mail)" <john_ibbotson@uk.ibm.com>, "Krishna Sankar (E-mail)" <ksankar@cisco.com>, "Lynne Thompson (E-mail)" <Lynne.Thompson@unisys.com>, "Marc Hadley (E-mail)" <marc.hadley@uk.sun.com>, "Mark Baker (E-mail)" <mark.baker@canada.sun.com>, "Martin Gudgin (E-mail)" <marting@develop.com>, Nick Smilonich <nick.smilonich@unisys.com>, "Oisin Hurley (E-mail)" <ohurley@iona.com>, "Scott Isaacson (E-mail)" <SISAACSON@novell.com>, "Yves Lafon (E-mail)" <ylafon@w3.org>
- Cc: xml-dist-app@w3.org
> >1) Are chained operations enough for you? From our discussions
> >I think not.
> >
> >2) If you want a single operation, through intermediaries,
> >which I think you
> >do, do you have a problem with the notion of a distinct event
> >to pass the
> >message 'up' to the XP handlers (encapsulated as an Intermediary
> >Application) and a second distinct event to pass them down again?
>
> I see - that makes a lot of sense - the current arrows in [1] are two
> ways but if I understand you right you want them to be
> separated out to
> indicate the direction. I have tried to illustrate this in [1] and [2]
> although not given the "events" any names. Would that work?
Cool... once you add the time dimension (the 4th we're now trying to capture
here) the diagram will be just too busy!
You can think of the double headed arrows that pass through the upper layer
boundary as the channels that the events flow through rather than the events
themselves. The diagram from my earlier message, repeated below, probably
got folks a bit confused because of the left/right orientation of the
arrows. With time going down the page it was intented to show the relative
sequence of events at those three crossing points between the XP layer and
the three groups of entities above the XP layer.
XMLP Application XMLP Application XMLP Application
(encap of (encap of (encap of
Handlers Q&R) Handlers @ T) Handlers U&V)
XMLP_UnitData. | | |
request | | |
----------------->| |XMLP_Intermediary. |
| |indication |
| |------> |
| |<----- |
| |XMLP_Intermediary. |XMLP_UnitData.
XMLP_UnitData. | |response |indication
confirm | | |------>
<-----------------| | |
| | |
[Time marching down the page. All the arrows going into/out of the layer
boundary of [1,2] from above]
or the alternate presentation... which is probably clearer - i think you can
see how you 'morph' between them.
+---------+ +--------------+ +---------+
| XMLP Ap | | Intermediary | | XMLP Ap |
| | | XMLP Ap | | |
+-+---+---+ +---+-------+--+ +----+----+
|1 ^5 ^2 | 3 ^4
+---|---|------------|-------|-----------|------+
V | | V |
One operation end-to-end:
1=Unidata.request, 4=UnitData.indication, 5=UnitData.confirm (5 may arise
any time after 1)
2=Intermediary.indication, 3=Intermediary.response
So... question... do you think we've got there, with perhaps the minor
wrinkle of what we actually call these two new events?
> Henrik
>
> [1] http://www.w3.org/2000/xp/Group/1/02/01-xmlprotocol-model2.gif
> [2] http://www.w3.org/2000/xp/Group/1/02/xmlprotocol-model2.ppt
>
Stuart
PS. I know that you've been keeping [1,2] uptodate, but the changes make
tracking the thread from the email a bit difficult when the picture changes.
Received on Friday, 9 February 2001 13:29:31 UTC