XOM API for Processing XML with Java

[Elliotte Harold <elharo AT metalab.unc.edu>]

Wolfgang Hoschek wrote:

> Small suggestion ("fruit hanging low"):
>
> 12% speedup in ParentNode.java for changing the static declaration of 
> childen from a List to an ArrayList (which it is anyway):
> ParentNode.java:
>
>     ArrayList   children;
>     //List   children;

That's easy enough to do, and doesn't really harm anything. It's a minor 
code smell at worst. However in my tests this had no noticeable effect. 
Can anyone explain why this might have such a dramatic effect? i.e is 
there any theoretical reason to believe this is a good idea? Is this 
likely to be very different from one VM to another? Is this something 
that might make a big difference in 1.5 and not 1.4? or the server VM 
and not the client?

Also, how do you measure the improvement? Is it just wall clock time 
with and without the change? I couldn't figure out how to get this 
number from the profiles you sent, though they were quite interesting 
with respect to where time was being spent, and did show me where to 
grab another ~20% improvement in typical building speed, though that 
won't help you since you're not using the Builder for these numbers.

--
Elliotte Rusty Harold  elharo AT metalab.unc.edu
XML in a Nutshell 3rd Edition Just Published!
http://www.cafeconleche.org/books/xian3/
http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim