Forwarding reply from author/maintainer of XML::LibXML. -------- Original Message -------- Subject: Re: Xpath query acceleration Date: Thu, 17 Jun 2010 14:09:33 +0200 From: Petr Pajas <[email protected]> To: Tom Metro <[email protected]> CC: L-boston-pm <[email protected]>
Depends on what you call slow and it does not make much sense using XPath lookup for this. If your XPath expressions involve sorting of largish node sets (.// may trigger sorting), then calling $doc->indexElements() once for the WSD schema file could help, because otherwise sorting to document order isn't O(n log(n)) as one would expect since comparison of the document order of two nodes is not O(1). Traversing the tree in Perl and using $node->attributes may or may not be faster (note that the Perl-XS-Perl transitions are surprisingly expensive even if the function you call in C is a noop, so introducing more such calls may slow your program down as well). I'd suggest: if the above don't help (and even if they do), look at the cases where you use the XPath and for stuff like the one you mentioned consider scanning once through all xs:attribute using @name and $type_def as keys. -- Petr _______________________________________________ Boston-pm mailing list [email protected] http://mail.pm.org/mailman/listinfo/boston-pm
