Re: [infinispan-dev] Avoid Collections.emptySet() / emptyMap() / emptyList

Galder, what JDK are you using?

OpenJDK 1.7 uses EmptyIterator.EMPTY_ITERATOR since 2007: http://hg.openjdk.java.net/jdk7/jdk7/jdk/annotate/37a05a11f281/src/share/...

I don't have JDK 1.6 sources on hand to check, but I don't think it's worth optimizing for such an old version anyway.

Cheers Dan On Fri, Oct 19, 2012 at 5:50 PM, Vladimir Blagojevic <vblagoje(a)redhat.com&gt; wrote: Cool! Did not know about this! Is this original idea or others are already doing this? On 12-10-19 8:31 AM, Galder Zamarreño wrote: > Hi all, > > Re: https://github.com/galderz/infinispan/commit/0609207d13216de81d77ff51dc20... > > Please avoid using these JDK methods where possible. I've created alternative versions in InfinispanCollections util class that provide a better implementation. > > The problem with the JDK versions is that even if these collections are immutable, if you wanna iterate them (i.e. for(X : emptySet) ), they'll create a brand new Iterator every time they're looped, and that generates useless garbage. > > The InfinispanCollections versions of emptyX will return a constant singleton iterator which avoids this problem, and avoids the need for client code to check if the collection is empty before looping. > > Cheers, > -- > Galder Zamarreño > galder(a)redhat.com > twitter.com/galderz > > Project Lead, Escalante > http://escalante.io > > Engineer, Infinispan > http://infinispan.org > > > _______________________________________________ > infinispan-dev mailing list > infinispan-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/infinispan-dev _______________________________________________ infinispan-dev mailing list infinispan-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev _______________________________________________ infinispan-dev mailing list infinispan-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev