cocoon-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Vadim Gritsenko" <vadim.gritse...@verizon.net>
Subject RE: Who needs 386% speed up?
Date Mon, 28 Jan 2002 14:20:55 GMT
> From: Sylvain Wallez [mailto:sylvain.wallez@anyware-tech.com]
> 
> Torsten Curdt wrote:
> 
> >On Sun, 27 Jan 2002, Vadim Gritsenko wrote:
> >
> >>Hi,
> >>
> >>While playing with OptimizeIt, I found quite interesting piece of
code
> >>in Xalan code, class org.apache.xml.utils.DefaultErrorHandler:
> >>
> >>  public DefaultErrorHandler()
> >>  {
> >>    m_pw = new PrintWriter(System.err, true);
> >>  }
> >>
> >So it's the creation of that PrintWriter that takes so long?

Yepp.

> >
> Do you know when is this class used, and why it is instancied so often
?

Used to report an exception. Search shows 8 files. The most important
ones are:
  org\apache\xalan\processor\TransformerFactoryImpl.java
  org\apache\xalan\transformer\TransformerIdentityImpl.java
  org\apache\xalan\transformer\TransformerImpl.java
  org\apache\xpath\XPath.java

It is instantiated as often as these classes are instantiated. In
Cocoon, TransformerIdentityImpl is used in every SAX pipeline at least
once.


> >>PS If somebody could ask Xalan guys to get rid of new PrintWriter()
-
> >>this would be great :)
> >>
> >Did post a message on Xalan Dev?

Nope... Yet.


> >>PPS XSPs *are* fast. XSL is slow :-|
> >>
> >...but people say XSPs are not skaling very good. AFAIR (vaguely)
Berin
> >tracked this down (also with optimizeIt) and it was a classloader
issue.
> >Berin, is this right? Please correct me if I am wrong... I guess this

I saw one issue with XSPs & classloaders: Every compilation of XSP
creates a ClassLoader (for obvious reasons), which is not garbage
collected (under OptimizeIt).


> >raised the monitoring thread...
> >
> ... or is this bad scalability a past myth ? I refactored
> ServerPagesGenerator at the beginning of december to make the
> document-completion stuff faster and optional (disabled by default).
> This was using a LinkedList to keep track of the open XML elements.
> 
> For more info, see
> http://marc.theaimsgroup.com/?l=xml-cocoon-dev&m=100739488123738&w=2
> 
> The next thing that's needed for XSP to be as fast as a regular
> generator is a way to remove unneeded white space used for indenting
in
> the XSP source : about half of produced SAX events are blank strings.

Ok, you already have a volunteer for this. Good luck, John! :)


> Sylvain
> 
> --
> Sylvain Wallez
> Anyware Technologies - http://www.anyware-tech.com


---------------------------------------------------------------------
To unsubscribe, e-mail: cocoon-dev-unsubscribe@xml.apache.org
For additional commands, email: cocoon-dev-help@xml.apache.org


Mime
View raw message