Grouper Developers Forum

[Chris Hyzer <>]

> And, KH, I see you still like the idea of regex and I believe that is
> overkill as well - why do we need it?  When I consider the many
> hundreds of thousands of operations we are considering for reasonable
> sized enterprise deployments - regex processing starts to mount up
> when you profile the code.  Of course, I should be basing my concern
> on facts and they are obviously absent, I apologize.  But, from my
> own experiences, regex processing *can* be expensive when done
> way too often - and I think this would be one of those cases.

About regex performance, I have never had a problem, (especially since we 
have to wait for db and ldap io).  This benchmark says that you can do 10k 
java regexes in 609ms, and the regex looks pretty complex.

http://www.tusker.org/regex/regex_benchmark.html

Remember to keep your regex Pattern objects cached so the expressions aren't 
recompiled each time.  The book "Java Performance Tuning" agrees, and states 
that regex is not expensive.  In a benchmark there it says that a regex is 
only a little slower than a toUpper and compare...  I think regex can be 
useful, as long as whoever is configuring can figure them out.  :)  Maybe to 
mitigate the complexity, just put a comment above the config:

#to do a prefix in regex, e.g. starts with 'somePrefix', use something like:  
    ^somePrefix.*$

Also, we already have regex in the grouper config, and I have been assuming 
they are fair game...

Chris