SAX, Java, and Namespaces (was Re: Restricted Namespaces for XML)

[David Megginson]

Tyler Baker writes:

 > As of JDK 1.1.6 things are not so bad and Java 2 is a bit better as
 > interned Strings are under the hood managed using Weak References.
 > It could be made better in the JDK though.  I suspect if they made
 > a real effort in the Java 2 JVM they could make string interns at
 > least twice as fast as things currently are.  Nevertheless, string
 > interning is a one time cost so lets put that in perspective here.

No, unfortunately it's much worse -- the parser has to re-intern
*every* element name and attribute name during the parse, so if I have
6,000 attributes named 'foo', I have to invoke intern 6,000 times
(just for those attributes).  When I was writing AElfred, I got
something between a 10-30% speedup (I cannot remember the number) by
dropping Java's intern and writing my own.  A bad intern is a killer
for an XML parser.


All the best,


David

-- 
David Megginson                 david at megginson.com
           http://www.megginson.com/

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