On Fri, 2 May 2025 17:24:06 GMT, Roger Riggs <[email protected]> wrote:
>> Refactor AbstractStringBuilder to maintain consistency among count, coder,
>> and value buffers while the buffer capacity is being expanded and/or
>> inflated from Latin1 to UTF16 representations.
>> The refactoring pattern is to read and write AbstractStringBuilder fields
>> once using locals for all intermediate values.
>> Support methods are static, designed to pass all values as arguments and
>> return a value.
>>
>> The value byte array is reallocated under 3 conditions:
>> - Increasing the capacity with the same encoder
>> - Increasing the capacity and inflation to change the coder from LATIN1 to
>> UTF16
>> - Inflation with the same capacity
>>
>> Added StressSBTest to exercise public instance methods of StringBuilder.
>
> Roger Riggs has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Optimize StringUTF16.putCharsAt a bit.
> Fixup hotspot Helper of putCharsAt to remove return value to match
> StringUTF16.putCharsAt.
src/java.base/share/classes/java/lang/AbstractStringBuilder.java line 1970:
> 1968: private static byte[] appendChars(byte[] value, byte coder, int
> count, char[] s, int off, int end) {
> 1969: if (isLatin1(coder)) {
> 1970: for (int i = off, j = count; i < end; i++) {
Suggestion:
int compressed = StringUTF16.compress(s, off, value, count, end -
off);
for (int i = compressed + off, j = count + compressed; i < end;
i++) {
Refer to PR #24773, adding StringUTF16.compress preprocessing here will improve
the performance of java.io.BufferedReader::readLine method.
Should it be done at once or separately for PR #24773 to make changes?
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PR Review Comment: https://git.openjdk.org/jdk/pull/24967#discussion_r2071954862
