java.util.UUID.fromString performance

[Vitaly Davidovich]

Mike,

I can certainly try to do that.  Given how trivial the change is and the
somewhat obvious observation that Long.parseLong would avoid boxing
compared to Long.decode, I was simply pointing out a fairly easy change
that could be made in case the maintainers of this class simply haven't
looked at optimizing this method a bit.  Obviously touching working code
shouldn't be taken lightly, but do you see any issues with using
Long.parseLong?

Thanks

Sent from my phone
On Feb 28, 2012 1:32 PM, "Mike Duigou" <mike.duigou at oracle.com> wrote:

> The easiest wat to proceed would be for you to submit a webrev patch with
> both changes along with your microbenchmark test. Once the change is
> incorporated in the jdk8 mainline the sustaining teams can evaluate it for
> backporting to jdk 7 and 6.
>
> Mike
>
> On Feb 28 2012, at 06:26 , Vitaly Davidovich wrote:
>
> > Hi all,
> >
> > I noticed that this method could be made a bit more performant by:
> >
> > 1) creating a statically initialized Pattern for "-" and then calling
> > split() on that.  Currently the method calls name.split() which compiles
> > the pattern on each invocation.
> >
> > 2) use Long.parseLong() instead of Long.decode() to extract the bits.
> >
> > With these changes, the method runs at least 20% faster (some runs were
> > significantly faster) on an Intel Westmere server and should be a bit
> more
> > GC friendly.
> >
> > Any thoughts? I can send the full code a bit later when I'm in front of
> my
> > computer.
> >
> > Thanks
> >
> > Sent from my phone
>
>