Thank you for your answer, to be honest, we're not sure about it. Could you give us a short intro on how Xerces loads XML documents? The DOMParser is using a specific XMLParserConfiguration to fill up an empty Document until it has finished completely parsing a file and returns the Document afterwards. However, how does the lazy-implementation work in that case? We'd imagine that the Document would need some kind of reference back to the parser to tell it "load more child items at node xyz"?
Of course it would be neat if we could simply extend the existing DocumentImpl (or CoreDocumentImpl) class and override required methods and afterwards all other parts of Xerces (like XPath, etc.) could work with it. If the Xerces parser is building up the Document by using the create*-methods on Document we could even do the required memory-swapping within the Document class by opening temporary files or a database connection (we're not sure about the actual implementation yet as this is ongoing research). -However we're not sure how to additionally use lazy loading to boost the performance in case the user is only reading very little parts of the big XML file. Hope you can help us a little bit on that part. All the best, D.R. (hope you don't mind our MS Outlook usage...normally people on mailing lists are not so fond of it) -----Original Message----- From: Jeff Greif [mailto:jeff.gr...@gmail.com] Sent: Donnerstag, 27. September 2012 22:47 To: j-users@xerces.apache.org; Dominik Rauch Subject: Re: Lazy DOM with regards to memory usage Would it be sufficient to specify your DOM's Document implementation class to the JAXP DocumentBuilderFactory using the factory's setAttribute method? See the first example here: http://xerces.apache.org/xerces2-j/properties.html On 9/27/2012 1:25 PM, Dominik Rauch wrote: > Hello Xerces-List! > > > > We're currently thinking about writing an advanced lazy DOM > implementation compliant with the W3C DOM specification. > > We know that there is already a Xerces lazy-loading-solution, however, > it is never unloading nodes, which becomes a problem for very big DOM > trees which do not fit into memory. > > > > There are some ideas and/or commercial products (like xDB), however, > no open-source solution yet. > > > > We want to know if it is possible to replace the Xerces DOM parser > with our own lazy implementation and reuse all the XPath/etc. features > from Xerces or if we need to write everything from scratch. > > > > Hopefully you can give us a positive answer and maybe show us the main > extension points where we would have to fit in our implementation (e.g. > classes/packages we would have to re-implement / derive / etc.) > > > > > > Best regards, > > D.R. > > Technical University of Vienna > > > --------------------------------------------------------------------- To unsubscribe, e-mail: j-users-unsubscr...@xerces.apache.org For additional commands, e-mail: j-users-h...@xerces.apache.org
