Re: Memoization

On Thu, Aug 22, 2002 at 08:13:21AM -0400, Daniel Veillard wrote:
>   Hum, there is no such mechanism, the only way would be to add an
> interface to libxslt to plug-in a document cache. Note that for a single
> transformation all the document() result are cached (this is actually
> required by the XSLT spec), but there is no mechanism for a more global
> cache. Could make sense, could be very small change if one doesn't
> try to implement a default cache in libxslt itself.

Ah, this is an interesting topic. What could actually be cached?
Won't an xml document like the following:

<doc>
  <a>&blub;</a>
</doc>

resolve to a different result depending on the entity declaration
in the importing document?

The really imteresting point (IMHO) would be: is it posible to
"compact" a parsed XML document (read: xmlDoc) to a memory area
of known size so it can be shared be means of shared memory?

 
 Ralf

> Daniel
> 
> On Thu, Aug 22, 2002 at 12:04:26PM +0100, Gary Benson wrote:
> > This is one of those "resending an issue after one week if there was no
> > answer might be a good idea" things -- hope you don't mind ;)
> > 
> >  -- Gary
> > 
> > On Thu, Aug 08, 2002 at 02:34:07AM +0100, Gary Benson wrote:
> > 
> > > Hiya,
> > > 
> > > I have an application which uses the Python bindings, and I've been
> > > looking at ways to speed it up. The profiler shows that about three
> > > quarters of the time is spent parsing XML files and there are _a lot_ of
> > > repeat parsings going on.
> > > 
> > > Now, it occurred to me that I could speed it up tremendously if I could
> > > somehow cache the parsed xmlDocs, but it isn't possible at the Python
> > > level since a lot of the repeat parsings are files loaded in the XSLT
> > > stylesheets via document().  To be truly effective I'd have to cache
> > > them within libxml itself.  Ideally, you'd call xmlParsedDocsCache(1) to
> > > enable the cache, such that the normal behaviour is unchanged.
> > > 
> > > I'd appreciate some insight from those who know libxml best (so probably
> > > Daniel :)).  Is what I'm talking about possible, and if it is where
> > > would be a nice place to implement it.  Obviously I'd like to be able to
> > > call xmlParsedDocsCache() from Python code, but how do I make that
> > > happen with the automated generator stuff? Libxml is a big bugger and
> > > it's hard to know where to start :)
> > > 
> > > Thanks in advance,
> > > Gary
> > > 
> > > [ [email protected] ][ GnuPG 85A8F78B ][ http://inauspicious.org/ ]
> > 
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> 
> -- 
> Daniel Veillard      | Red Hat Network https://rhn.redhat.com/
> [email protected]  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
> http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
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