I haven't had a chance to analyze this yet (and I may not be able to
this week), but one quick point is that wherever the Saxon performance
problem is, it's not actually in exsl:node-set(). That's because all
that exsl:node-set() does is to flip a bit saying that the tree can be
used as a normal document.
The problem (or opportunity for improvement!) is much more likely to be
in optimization of copying operations on trees.
An observation, on line 65 of incelim.xsl
<xsl:copy-of select="exsl:node-set($rng)"/>
there is no need for a call on exsl:node-set() here. You can copy an RTF
directly.
Michael Kay
-----Original Message-----
From: owner-xsl-list(_at_)lists(_dot_)mulberrytech(_dot_)com
[mailto:owner-xsl-list(_at_)lists(_dot_)mulberrytech(_dot_)com] On Behalf Of
David Tolpin
Sent: 17 January 2004 06:10
To: xsl-list(_at_)lists(_dot_)mulberrytech(_dot_)com
Subject: Re: [xsl] exsl:node-set in xalan
[ Charset ISO-8859-1 unsupported, converting... ]
Not sure this helps, but I get 12 sec for the shell script & only
3.5 with the stylesheet using 3 rinses on xhtml.rng. This is
with Saxon 6.5.3 on RedHat with a 2.4GHz proc. Sounds like it
might still be something environmental rather than Saxon.
I've been able to reproduce the result for xhtml with JDK
1.4.1/HotSpot (the
original results where with 1.3.1_08/OpenJIT, which launches
faster and runs
slower), but it does not change the trend. While the
relatively small xhtml
(which is a toy for the application) is faster, the larger
TEI or DocBook are
still much slower. With JDK 1.4.1/HotSpot, the stylesheet version is
3 times faster than the script version for Xhmtl, 80Kb,
but 2.5 times slower with DocBook, which is 900Kb.
In practice, stylesheets can be larger than DocBook in the
example (docbook
with MathML and SVG, for example). But whether a stylesheet
is large or small,
why the dependency is so steep in both SAXON and jd.xslt?
This behaviour is also exhibited by jd.xslt, but not by Xalan.
Xalan consistenly runs the stylesheet version faster on any
data with exsl
stylesheet than with the script.
David Tolpin
http://davidashen.net/
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
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