(CR#6553074) Unnecessary array copy in AbstractStringBuilder.indexOf(String)?
Mike Duigou
mike.duigou at oracle.com
Mon Nov 19 17:49:22 UTC 2012
By amazing coincidence a review for fixing this was issued last week:
http://mail.openjdk.java.net/pipermail/core-libs-dev/2012-November/012266.html
Additional review would be welcome. :-)
The patch will probably be ready for push before the end of the month.
Mike
On Nov 19 2012, at 07:46 , Martin Desruisseaux wrote:
> Hello all
>
> I noticed that AbstractStringBuilder.indexOf(String, int) is implemented as below:
>
> public int indexOf(String str, int fromIndex) {
> return String.indexOf(value, 0, count,
> str.toCharArray(), 0, str.length(), fromIndex);
> }
>
> The call to str.toCharArray() creates a copy of the String.value char[] array. This copy doesn't seem necessary since the above String.indexOf(...) method doesn't modify the array content. Shouldn't AbstractStringBuilder passes directly the reference to the String internal array instead, maybe using package-privated access to the array?
>
> Admittedly the cloned array is usually small, but the call to indexOf(String, int) is often done in a loop.
>
> Martin
>
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