Extra allocations in `*TextFormatWriter` because of Java 8 target

See this line of code:

https://github.com/prometheus/client_java/blob/fa68aa7789c53d54ea1783f120194a3feae7e7b8/prometheus-metrics-exposition-textformats/src/main/java/io/prometheus/metrics/expositionformats/OpenMetricsTextFormatWriter.java#L412

Because of the Java 8 target, the string concatenation gets compiled to something like new StringBuilder().append(name).append(suffix).toString(), which allocates the memory at least twice (for the buffer in the StringBuilder and for the resulting string).

If the code was compiled for at least Java 9, it would use StringConcatFactory, which in this case would allocate the memory only for the resulting string.

Would the maintainers consider publishing multiple artifacts for different Java targets, or using multi-release JARs for the purpose of this and similar optimizations?

Inizia da OpenMetricsTextFormatWriter.java alla riga collegata e verifica come il progetto abbia come target Java 8. Quindi analizza le opzioni di pubblicazione degli artifact e di multi-release JAR descritte nell’issue. Il lavoro sarà completo quando sarà disponibile un approccio documentato e approvato dai maintainer per ridurre queste allocazioni nel codice TextFormatWriter interessato.