On Tue, 6 May 2025 15:23:39 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:
>
> Apply reviewer suggestions for typos, javadoc, and copyright dates.
Some of the new methods in ASB are still unsafe; I need to spend more time to
verify each of their use cases.
src/java.base/share/classes/java/lang/AbstractStringBuilder.java line 270:
> 268: private static byte[] ensureCapacityNewCoder(byte[] value, byte
> coder, int count,
> 269: int minimumCapacity,
> byte newCoder) {
> 270: assert coder == newCoder || newCoder == UTF16 : "bad new coder
> UTF16 -> LATIN1";
I recommend an additional assertion `count <= minimumCapacity`; even though all
callers ensure this currently, in case this is accidentally violated, we are
sending dangerous arguments to `StringLatin1.inflate`.
Also, the message string of assertion can include the `coder` and `newCoder`
values. Same for the other assertions we add.
src/java.base/share/classes/java/lang/AbstractStringBuilder.java line 321:
> 319: */
> 320: private static byte[] inflateToUTF16(byte[] value, int count) {
> 321: byte[] newValue = StringUTF16.newBytesFor(value.length);
Same value.length vs count assertion recommendation
-------------
PR Review: https://git.openjdk.org/jdk/pull/24967#pullrequestreview-2818880544
PR Review Comment: https://git.openjdk.org/jdk/pull/24967#discussion_r2075825884
PR Review Comment: https://git.openjdk.org/jdk/pull/24967#discussion_r2075827576
