java.util.UUID.fromString performance (original) (raw)

Vitaly Davidovich vitalyd at gmail.com
Wed Feb 29 00:17:31 UTC 2012

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

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