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Re: Exclusive C14n in Apache

From: Christian Geuer-Pollmann <geuer-pollmann@nue.et-inf.uni-siegen.de>
Date: Mon, 27 May 2002 17:29:32 +0200
To: reagle@w3.org, jboyer@PureEdge.com
Cc: w3c-ietf-xmldsig@w3.org
Message-ID: <12201675.1022520572@pinkpanther>


--On Freitag, 24. Mai 2002 18:34 -0400 Joseph Reagle <reagle@w3.org> wrote:

> On Thursday 23 May 2002 17:13, Christian Geuer-Pollmann wrote:
>> I implemented exclusive c14n for the Apache package. On my
>> implementation, exclusive c14n is SLOWER than inclusive c14n:
>>
>>    Factor between 1.3 and 1.6
>
> Do you have a sense of why? In some cases I expect some variances, but
> this  is rather surprising. The intent was to simplify a number of things
> c14n  processing required such as (1) checking to see if the parent
> element is in  the subset on that xml:foo issue we've been discussing and
> (2) if you have  a subset in a small document, you don't have to walk up
> the tree to find  ancestor xml:foo attributes.

Well, the main difference between inclusive and exclusive c14n is that in 
inclusive c14n, I can simply output the changes to the inscope namespace 
decls. In exclusive c14n, I also have to check whether a namespace is 
visibly utilized. That's the additional overhead. But I have to reduce this 
1.3-1.6 to a lower level of 1.1-1.2.


Regards,
Christian
Received on Monday, 27 May 2002 11:24:24 GMT

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