Reactive scrabble benchmarks

This package contains reactive scrabble benchmarks.

Reactive Scrabble benchmarks were originally developed by José Paumard and are available under Apache 2.0, Flow version is adaptation of this work. All Rx and Reactive benchmarks are based on (or copied from) David Karnok work.

Benchmark classes

The package (split into two sourcesets, kotlin and java), contains different benchmarks with different purposes

• RxJava2PlaysScrabble and RxJava2PlaysScrabbleOpt are copied as is and used for comparison. The infrastructure (e.g. FlowableSplit) is copied from akarnokd-misc in order for the latter benchmark to work. This is the original benchmark for RxJava.
• ReactorPlaysScrabble is an original benchmark for Reactor, but rewritten into Kotlin. It is disabled by default and had the only purpose -- verify that Kotlin version performs as the original Java version (which could have been different due to lambdas translation, implicit boxing, etc.). It is disabled because it has almost no difference compared to RxJava benchmark.
• FlowPlaysScrabbleBase is a scrabble benchmark rewritten on top of the Flow API without using any optimizations or tricky internals.
• FlowPlaysScrabbleOpt is an optimized version of benchmark that follows the same guidelines as RxJava2PlaysScrabbleOpt: it still is lazy, reactive and uses only Flow abstraction.
• SequencePlaysScrabble is a version of benchmark built on top of Sequence without suspensions, used as a lower bound.
• SaneFlowPlaysScrabble is a SequencePlaysScrabble that produces Flow. This benchmark is not identical (in terms of functions pipelining) to FlowPlaysScrabbleOpt, but rather is used as a lower bound of Flow performance on this particular task.

Results

Benchmark results for throughput mode, Java 1.8.0_172 running on Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz under Darwin Kernel Version 18.7.0. Full command: java -jar benchmarks.jar -f 2 -jvmArgsPrepend "-XX:+UseParallelGC" '.*Scrabble.*'.

Benchmark                     Mode  Cnt   Score   Error  Units  

FlowPlaysScrabbleBase.play    avgt   14  62.480 ± 1.018  ms/op
FlowPlaysScrabbleOpt.play     avgt   14  13.958 ± 0.278  ms/op

RxJava2PlaysScrabble.play     avgt   14  88.456 ± 0.950  ms/op
RxJava2PlaysScrabbleOpt.play  avgt   14  23.653 ± 0.379  ms/op

SaneFlowPlaysScrabble.play    avgt   14  13.608 ± 0.332  ms/op
SequencePlaysScrabble.play    avgt   14   9.824 ± 0.190  ms/op