`log.isXXXEnabled()` causes allocation overhead

[kamilkloch]

log.isDebugEnabled() causes a lot of unnecessary allocations, going through

    override def predicate(level: Level): CorePredicate =
      new CorePredicate.Impl(level, this)

in CoreLogger.Abstract

Arguably, this operation should be as lightweight as possible.

[wsargent]

It's assigned to a val.

blindsight/api/src/main/scala/com/tersesystems/blindsight/slf4j/SLF4JLogger.scala

Line 53 in 8bd69d5

val isDebugEnabled: Predicate = predicate(DEBUG)

Please see https://tersesystems.github.io/blindsight/performance/memory.html and https://tersesystems.github.io/blindsight/performance/benchmarks.html and I also wrote a couple of blog posts:

• https://tersesystems.com/blog/2020/07/09/logging-vs-memory/
• https://tersesystems.com/blog/2020/08/23/benchmarking-logging-with-jdk-14/