IPP> ippget Design Needs Work [use multi-part/related?]

IPP> ippget Design Needs Work [use multi-part/related?]

Michael Sweet mike at easysw.com
Fri Jul 20 15:06:28 EDT 2001


"Hastings, Tom N" wrote:
> ...
> Your idea of using multi-part/related with each part being an
> application/ipp part.  The first part is the initial response with all the
> pending Event Notifications (and doesn't end with the
> 'end-of-attributes-tag').  Each subsequent part is one or more additional
> Event Notification Attributes Groups that have occurred as a "bunch" (and
> doesn't end with the 'end-of-attributes-tag').  The last part will contain
> one or more Event Notification Attributes Groups and an
> 'end-of-attributes-tag' when there are no more events possible (all
> Subscription objects in the scope of the Get-Notifications are gone or the
> Printer wants to end wait mode and returns the "notify-get-interval"
> attribute in a separate Event Notification Attributes Group).
> ...

I think that we need to make each part a valid/standard
IPP message of its own:

    1. The application/ipp type defines an IPP "message" that
       can be a request or response.  The format is identical
       save for a different interpretation of the operation
       or status code field.

    2. It will simplify client and server implementations -
       only 1 type of IPP data stream needs to be supported.

    3. It will allow the parts to be received in any order -
       not too important for the current HTTP transport, but
       might be important for other types of transports.

    4. It mirrors what the mailto and indp methods do - that
       is, one standard message format for each collection of
       events.

I think the only issue is what the status code field will
contain in the parts - should they all contain the same code,
or should each IPP message contain the current server status
(e.g. successful-ok-too-many-events)?

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products                  mike at easysw.com
Printing Software for UNIX                       http://www.easysw.com



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