(CR#6553074) Unnecessary array copy in AbstractStringBuilder.indexOf(String)?

Ulf Zibis Ulf.Zibis at CoSoCo.de
Mon Nov 19 21:12:51 UTC 2012


I'm wondering, if we still need
1739     static int indexOf(char[] source, int sourceOffset, int sourceCount,
1740             char[] target, int targetOffset, int targetCount,
1741             int fromIndex) {
since bug 6924259: Remove offset and count fields from java.lang.String.

I guess we only need
1739     static int indexOf(char[] source, int sourceCount,
1740             char[] target, int fromIndex) {


Am 19.11.2012 18:49, schrieb Mike Duigou:
> 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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