On Wed, 10 Nov 2021 17:44:04 GMT, Eamonn McManus wrote:
> Use string concatenation instead of `String.format`.
I talked to Brian about this a bit. Changing `format` to concatenation is
probably ok this case for two reasons: 1) it's the simplest possible such
transformation, and as such it's not a very good example for the templating
stuff; and 2) presumably you bothered filing the bug and the PR because you
believe the performance improvement would be noticeable in actual systems.
I note that some Amazon folks had filed
[JDK-8275190](https://bugs.openjdk.java.net/browse/JDK-8275190) for what is
essentially the same issue. (I closed it as a dupe.) They did include some
performance numbers, but not the actual code they measured, so without guessing
it's hard to say what they actually measured. Could you run some numbers and
post them, and can you share some estimates of the impact it might have on your
systems?
The reason I'm interested in some data here is that this sort of change is
worth doing only if it has a real, measurable impact. In turn that implies that
you're probably using `Optional::toString` a lot. That's an important
criterion; we don't want to do a wholesale replacement of `format` with
concatenation in the JDK, based on some micro benchmarks, that end up garbaging
up the JDK code base while not actually improving any real systems.
-
PR: https://git.openjdk.java.net/jdk/pull/6337