Re: [xsl] Optimizing XSLT iteration

[Abel Braaksma <abel.online@xxxxxxxxx>]

Hi Sujata,

See my comments below,



Sujata Gohad wrote:
> In order to convert it to SVG format:
>
> <?xml version=' 1.0' encoding='UTF-8'?>
> <?xml-stylesheet href="hvm_to_svg.css" type="text/css"? >
>   

Does this actually work? Are you calling an XSLT stylesheet as being 
type "text/css" and you call it ***.css? Your processor (which one are 
you using?) seems quite forgiving (or maybe I am missing something ;)

> ....
>             <xsl:for-each select="component">
>                 <xsl:for-each select="trace">
>                     <path >
>                         <xsl:attribute name="class"> trace</xsl:attribute >
>                         <xsl:attribute name="d">
>                             <xsl:for-each select="locus[position()=1]">

This nested for-each is probably easier written and easier maintainable 
when you write it as apply-template/template matching pairs. This way 
you make use of the features of XSLT and let it choose the best 
execution path, instead of telling the processor what you think is best.

> XSLT profiler shows that 80% of the time is spent in enumerating the
> "locus" elements?
>
> Is there a way to faster iteration of the "locus" elements?

That sounds about right. In the source snippet you showed, just about 
95% of all your lines are about "locus" elements, no? So, to be fair, 
the processing of those elements should take about 95%, if the ratio 
would apply. Perhaps your code is even quicker than the apply-template 
approach? But I wouldn't bet on it. But even if the code runs quicker, 
it would still be 80% or something that is spend on the locus elements.

Cheers,
-- Abel Braaksma