XOM API for Processing XML with Java

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

At 3:53 PM -0500 9/18/03, Dick Hollenbeck wrote:
> Please be careful of the cycle dependency checking code's overhead 
> and how it might impact the speed of document building.  This 
> checking is probably best done by using Assert()s so that it can be 
> compiled in and out easily, as needed.
> Speed is more important for most of us.  We'll find our bugs eventually.
>
> Rusty, have you done a before and after benchmark?   This feature is 
> not worth a speed hit to me.

I'll eventually look into ways of speeding it up, but I do not 
believe speed is more important than correctness. A program that does 
the wrong thing 1000 times faster is useless. The only reason this 
check wasn't in since the beginning is that I mistakenly thought the 
multiple parent checks would catch it. I should have a written a unit 
test to verify that assumption. :-(

One thing all my profiling shows is that the only places speed 
matters are parsing and serialization. These completely swamp 
in-memory manipulations. This change has no effect on serialization. 
I should be able to eliminate it from having any effect on parsing as 
well. Parsing currently short circuits a lot of checks the parser has 
already done. I should be able to short this one too, though it may 
not currently be short circuited in 1.0d21.

--

  Elliotte Rusty Harold
  elharo AT metalab.unc.edu
  Processing XML with Java (Addison-Wesley, 2002)
  http://www.cafeconleche.org/books/xmljava
  http://www.amazon.com/exec/obidos/ISBN%3D0201771861/cafeaulaitA