On Sat, 12 Oct 2024 07:47:56 GMT, Markus KARG <d...@openjdk.org> wrote:
>> This Pull Requests proposes an implementation for >> [JDK-8341566](https://bugs.openjdk.org/browse/JDK-8341566): Adding the new >> method `public static Reader Reader.of(CharSequence)` will return an >> anonymous, non-synchronized implementation of a `Reader` for each kind of >> `CharSequence` implementation. It is optimized for `String`, >> `StringBuilder`, `StringBuffer` and `CharBuffer`. >> >> In addition, this Pull Request proposes to replace the implementation of >> `StringReader` to become a simple synchronized wrapper around >> `Reader.of(CharSequence)` for the case of `String` sources. To ensure >> correctness, this PR... >> * ...simply moved the **original code** of `StringBuilder` to become the >> de-facto implementation of `Reader.of()`, then stripped synchronized from it >> on the left hand, but kept just a synchronized wrapper on the right hand. >> Then added a `switch` for optimizations within the original code, at the >> exact location where previously just an optimization for `String` lived in. >> * ...added tests for all methods (`Of.java`), and applied that test upon the >> modified `StringBuilder`. >> >> Wherever new JavaDocs were added, existing phrases from other code locations >> have been copied and adapted, to best match the same wording. > > Markus KARG has updated the pull request incrementally with one additional > commit since the last revision: > > Revert 'inc should be faster than add on most CPUs' src/java.base/share/classes/java/io/Reader.java line 214: > 212: cbuf[off + i] = cs.charAt(next + i); > 213: } > 214: } Just a drive-by observation, not for this PR to handle: If four out of five `CharSequence` implementations in the JDK include fast-path methods for copying char ranges into an output buffer, perhaps it is time to introduce `CharSequence::getChars` as a default method? That way, code like this wouldn't need to special-case for the known fast-paths, and external implementations could also join the party. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/21371#discussion_r1799981701
