On Mon, 11 Jul 2022 08:02:43 GMT, Сергей Цыпанов <d...@openjdk.org> wrote:
>> The new constructor looks very odd, especially when it does not have an >> explanation and doesn't describe the required preconditions for calling it. >> Is there a better way than adding a non-functional argument? >> The "unused" name is going to draw a warning from IntelliJ and some >> enterprising developer is going to try to remove it, not understanding why >> its there. And there is a bit of overhead pushing the extra arg. >> >> The constructor should be private, it has a very narrow scope of use given >> the lack of checking its args. >> >> It would be nice if the Hotspot compiler would recognize the llmits on the >> range and optimize away the checks; >> it would have broader applicability then this point fix. >> I would be interesting to ask the compiler folks if that's a future >> optimization. >> These source changes make it harder to understand what's happening where; >> though that is sometimes work it for a noticeable performance improvement. > > Well, we already have e.g. `String(char[], int, int, Void)` and > `String(AbstractStringBuilder asb, Void sig)` where trailing argument is for > disambiguation against private constructors. I did the same for mine and > applied the same naming as in other trailing `Void` params. Benchmark results after: Benchmark Mode Cnt Score Error Units StringConstructor.newStringFromArray avgt 50 4,354 ± 0,195 ns/op StringConstructor.newStringFromArrayWithCharset avgt 50 4,035 ± 0,088 ns/op StringConstructor.newStringFromArrayWithCharsetName avgt 50 8,166 ± 0,062 ns/op StringConstructor.newStringFromRangedArray avgt 50 4,132 ± 0,054 ns/op StringConstructor.newStringFromRangedArrayWithCharset avgt 50 4,416 ± 0,206 ns/op StringConstructor.newStringFromRangedArrayWithCharsetName avgt 50 7,421 ± 0,041 ns/op ------------- PR: https://git.openjdk.org/jdk/pull/9407
