On Mon, 11 Apr 2022 19:22:21 GMT, Roger Riggs <rri...@openjdk.org> wrote:
> Is there jmh test data to quantify the improvement? Not yet as I don't really know how to run a jmh for a package static function, who calls some other class private functions... Should I put the test upon StringJoiner insterad, as it called String.join? I would have a try. > src/java.base/share/classes/java/lang/String.java line 3290: > >> 3288: value, >> 3289: off << coder, >> 3290: delimiterLengthWithCoder > > Is there any benefit to special casing short delimiters? 1..4 bytes? > Arraycopy has a fixed overhead regardless of the delimiter length. > I might expect a big payoff for coder = Latin1 and delimiter length == 1..2 > compared to arraycopy. yes I think there should be performance benifitial when delimiter coder be Latin 1 and output not, which would call StringLatin1.inflate for many times, that is a waste. ------------- PR: https://git.openjdk.java.net/jdk/pull/8169
