RFR: 8366224: Introduce DecimalDigits.appendPair for efficient two-digit formatting and refactor DateTimeHelper [v21]

[Shaojin Wen]

On Thu, 13 Nov 2025 16:40:45 GMT, Johannes Döbler <duke at openjdk.org> wrote:

>> Shaojin Wen has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   add comments
>
> src/java.base/share/classes/java/time/MonthDay.java line 758:
> 
>> 756:         buf.append('-');
>> 757:         DecimalDigits.appendPair(buf, day);
>> 758:         return buf.toString();
> 
> Why not
> 
>     byte[] bytes = new byte[7];
> 	bytes[0] = (byte)'-';
> 	bytes[1] = (byte)'-';
> 	DecimalDigits.appendPair(bytes, 2, month); // TBD
> 	bytes[4] = (byte)'-';
> 	DecimalDigits.appendPair(bytes, 5, month);
> 	return JLA.uncheckedNewStringWithLatin1Bytes(bytes);

That's a good suggestion, but such optimization is irrelevant to this PR, or it should be done in a separate PR.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/26911#discussion_r2527645555