W3C home > Mailing lists > Public > xml-dist-app@w3.org > April 2001

RE: update to Issue #82

From: Williams, Stuart <skw@hplb.hpl.hp.com>
Date: Fri, 27 Apr 2001 11:34:05 +0100
Message-ID: <5E13A1874524D411A876006008CD059F1923E5@0-mail-1.hpl.hp.com>
To: "'Mark Jones'" <jones@research.att.com>
Cc: xml-dist-app@w3.org, frystyk@microsoft.com

> -----Original Message-----
> From: Mark Jones [mailto:jones@research.att.com]
> Sent: 26 April 2001 04:10
> To: frystyk@microsoft.com
> Cc: xml-dist-app@w3.org
> Subject: RE: update to Issue #82


> An intermediary interested only in this final block would still have
> to parse through the body block in the envelope to get to the final
> block.  How would this be any better than just permitting the header
> block to follow the body block (without the forward reference hack)?
> I guess it would allow intermediaries that weren't interested in
> following any forward references to quit when they hit the body, but
> it doesn't always help and it introduces some additional complication.
> Something that I have never quite understood is how burdensome it is
> for an intermediary to find targeted blocks and to construct the
> forwarded message.  It seems to me that a block that is not targeted
> at the current node can be streamed on through as a part of the
> forwarded message;

Yes... but if the act of processing the targetted block has an influence on
where a message is sent next (eg. its a message routing block) then next
destination may not yet be known and the outbound message will need to be
buffered until that can be determined. This may be be moot in the case of
real intermediaries which will probably be a bit more resource rich than
your average handheld.

> the processor basically just has to find the
> matching angle brackets that terminate the block.  This shouldn't be
> hard even for a memory-limited device.  A block that is targeted at
> the current node might be able to be incrementally processed by a
> memory-limited processor as it is parsed without keeping it all in
> memory as well.  So with the right implementation, I'm not sure why
> skipping parts of the message is important anyway -- as an
> intermediary you have to forward blocks not targeted at yourself, so
> you still have to handle all of the message bytes one way or 
> the other.
> --mark



Received on Friday, 27 April 2001 06:34:17 UTC

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