[jboss-dev] Further profling: Where should I focus?

[Andrew Dinn]

On 01/05/2010 07:42 PM, Bill Burke wrote:
> public List<Closeable> recursiveMount(VirtualFile file) throws
> IOException
>      {
>         ArrayList<Closeable>  mounts = new ArrayList<Closeable>();
>
>         if (!file.isDirectory()&&
> file.getName().matches("^.*\\.([EeWwJj][Aa][Rr]|[Zz][Ii][Pp])$"))
>            mounts.add(VFS.mountZip(file, file, provider));
>
>         /****** Doubled speedup when this was commented out!!!!!!!!!!!!
>         if (file.isDirectory())
>            for (VirtualFile child : file.getChildren())
>               mounts.addAll(recursiveMount(child));
>               */
>
>
>         return mounts;
>      }

Irrespective of the answer to any general issues over caching it is 
clear in this case that the 2 calls to file.isDirectory() can quite 
legitimately be replaced with a single call and a local variable to 
stash/test the result (it's a shame the compiler cannot figure this out 
but so it goes). Since this code actually turned up in the profiling as 
a major source of overhead then the obvious thing to do in response is 
patch it and see what turns up next then keep going until easy to fix 
things like this stop turning up. Saves us wasting time in protracted 
arguments as well ;-)

regards,


Andrew Dinn
-----------


-- 
regards,


Andrew Dinn
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Senior Software Engineer, JBoss
Red Hat UK Ltd
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