(Seems like this should have gone to the xalan list, which may be why I
missed it...)
> I need to be able to instantiate a Document without parsing, so it looks
like my only
> choice is the Xerces classes, even though they are slower than the DTM.
Again, please comment.
Yes, you need to use the Xerces liaison... liaison's tightly couple to a
given DOM implementation.
The only real reason the Xerces dom liaison is a disadvantage in terms of
speed is node-order sorting and on-the-fly namespace resolution, since the
DOM is already parsed, and incrementality and memory use (in terms of the
size of the DOM, since it is already constructed) aren't factors for your
case. The node order sorting we hope to solve with a new search algorithm
we are working on. The namespace resolution might be better with some of
the work they've been putting into the Xerces DOM lately (I have to go back
and re-investigate this). For certain operations (non-union selections),
the DOM will actually be a tiny bit faster.
So, my advice would be to go ahead and use the Xerces liaison, and the
performance differences that are applicable to your case will be resolved
over the next few weeks.
-scott
Paul Levin
<[EMAIL PROTECTED] To: [EMAIL PROTECTED]
om> cc: (bcc: Scott Boag/CAM/Lotus)
Subject: Re: question about Parser
Liaison and Documents
01/31/00
01:51 PM
Please
respond to
xerces-dev
Can someone please comment on this. I posted this last Thursday, and no
one has made any comments.
Thanks,
Paul
Paul Levin wrote:
I realize that the Document implementation class used, and the
ParserLiaison class used, are tightly coupled.
I notice, in the latest Xalan distribution, that there are 2 significant
Liaison/Document packages --
|-------------------------------------------+---------------------------------------|
| ParsserLiaison Class | Document Impl Class
|
|-------------------------------------------+---------------------------------------|
| org.apache.xalan.xpath.xdom.XercesLiaison |
org.apache.xerces.dom.DocumentImpl |
|-------------------------------------------+---------------------------------------|
| org.apache.xalan.xpath.dtm.DTMLiaison |
org.apache.xalan.xpath.dtm.DTMProxy |
|-------------------------------------------+---------------------------------------|
I am trying to understand some pros and cons of these 2 choices.
It seems that the DTM classes are supposed to be faster than the
Xerces classes.
The Xerces DocumentImpl class has a constructor (so a document
can be made without having to parse a file); where as the
DTMProxy class has no constructor.
Would people please comment on these findings, and correct me where I
am wrong,
I need to be able to instantiate a Document without parsing, so it
looks like my only choice is the Xerces classes, even though they are
slower than the DTM. Again, please comment.
Thanks
