Benedikt Ritter wrote: > 2015-05-05 17:51 GMT+02:00 Jörg Schaible <joerg.schai...@swisspost.com>: > >> Hi Benedikt, >> >> Benedikt Ritter wrote: >> >> > 2015-05-05 14:52 GMT+02:00 Benedikt Ritter <brit...@apache.org>: >> > >> >> Hello Jörg, >> >> >> >> 2015-05-05 8:30 GMT+02:00 Jörg Schaible >> >> <joerg.schai...@swisspost.com>: >> >> >> >>> Hi Benedikt, >> >>> >> >>> brit...@apache.org wrote: >> >>> >> >>> > Repository: commons-lang >> >>> > Updated Branches: >> >>> > refs/heads/master 8548b12d8 -> 60b32953a >> >>> > >> >>> > >> >>> > Allocate array of the correct size >> >>> > >> >>> > >> >>> > Project: http://git-wip-us.apache.org/repos/asf/commons-lang/repo >> >>> > Commit: >> >>> > http://git-wip-us.apache.org/repos/asf/commons-lang/commit/60b32953 >> >>> Tree: >> >>> > http://git-wip-us.apache.org/repos/asf/commons-lang/tree/60b32953 >> >>> > Diff: >> >>> > http://git-wip-us.apache.org/repos/asf/commons-lang/diff/60b32953 >> >>> > >> >>> > Branch: refs/heads/master >> >>> > Commit: 60b32953a968e5623f82a6b27d6c679bc17c48e5 >> >>> > Parents: 8548b12 >> >>> > Author: Benedikt Ritter <brit...@apache.org> >> >>> > Authored: Mon May 4 21:26:07 2015 +0200 >> >>> > Committer: Benedikt Ritter >> >>> > <brit...@apache.org> Committed: Mon May 4 >> >>> > 21:26:07 2015 +0200 >> >>> > >> >>> > >> ---------------------------------------------------------------------- >> >>> > .../apache/commons/lang3/builder/ReflectionToStringBuilder.java >> >>> > | 2 >> >>> +- >> >>> > 1 file changed, 1 insertion(+), 1 deletion(-) >> >>> > >> ---------------------------------------------------------------------- >> >>> > >> >>> > >> >>> > >> >>> >> http://git-wip-us.apache.org/repos/asf/commons-lang/blob/60b32953/src/main/java/org/apache/commons/lang3/builder/ReflectionToStringBuilder.java >> >>> > >> ---------------------------------------------------------------------- >> >>> > diff --git >> >>> > >> >>> >> >>> >> >> a/src/main/java/org/apache/commons/lang3/builder/ReflectionToStringBuilder.java >> >>> > >> >>> >> >>> >> >> b/src/main/java/org/apache/commons/lang3/builder/ReflectionToStringBuilder.java >> >>> > index 5904469..7a78170 100644 --- >> >>> > >> >>> >> >>> >> >> a/src/main/java/org/apache/commons/lang3/builder/ReflectionToStringBuilder.java >> >>> > +++ >> >>> > >> >>> >> >>> >> >> b/src/main/java/org/apache/commons/lang3/builder/ReflectionToStringBuilder.java >> >>> > @@ -333,7 +333,7 @@ public class ReflectionToStringBuilder extends >> >>> > ToStringBuilder { >> >>> > list.add(e.toString()); >> >>> > } >> >>> > } >> >>> > - return list.toArray(ArrayUtils.EMPTY_STRING_ARRAY); >> >>> > + return list.toArray(new String[list.size()]); >> >>> > } >> >>> >> >>> What's the benefit of this? Where's the difference by letting >> >>> List.toArray() >> >>> allocate the appropriate array compared to do it on your own? >> >>> ArrayUtils.EMPTY_STRING is a constant after all, so there's no >> >>> additional allocation. >> >>> >> >> >> >> I changed this because my IDE complained about that line of code: >> >> >> >> "Call to 'toArray' with zero-length array argument >> >> 'ArrayUtils.EMPTY_STRING_ARRAY' >> >> >> >> Reports any call to 'toArray' on an object or type or subtype of >> >> java.util.Collection with a zero-length argument. When passing an >> >> array of too small size, the toArray() method has to construct a new >> >> array of the correct size using reflection. This has significantly >> >> worse performance than passing in an array of at least the size of the >> >> collection itself." >> >> >> >> To be honest, I did not do any performance benchmarks to make sure >> >> this is really true. >> >> >> > >> > In any case, the commit message should have been more explanatory. >> > Sorry about that. >> >> Well, that warning is somewhat stupid, if you're using a constant for the >> zero length array. The "worse performance" only occurs if you provide a >> new array instance that is too small. >> > > ... which will always be the case unless the list is empty, or am I > missing something here?
Where's the difference in creating a new array of proper size yourself or let the method do it? It's even worse now, because now you create a new instance *even* if the list is empty. Cheers, Jörg --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
