TypedArrayBenchmark.kt

@State(Scope.Benchmark)
@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(BenchmarkTimeUnit.MILLISECONDS)
@Warmup(iterations = 4, time = 10, timeUnit = BenchmarkTimeUnit.SECONDS)
@Measurement(iterations = 4, time = 10, timeUnit = BenchmarkTimeUnit.SECONDS)
public class TypedArrayBenchmark {
  private var fromArray = ByteArray(0)

  @Param("100", "1000", "5000", "15000", "100000")
  public var newSize: Int = 0

  @Setup
  public fun setup() {
    val size = 10000
    val range = -127..127
    val array = ByteArray(size)

    for (i in 0..<size) {
      array[i] = range.random().toByte()
    }

    fromArray = array
  }

  @Benchmark
  public fun fillFrom(blackhole: Blackhole) {
    val toArray = ByteArray(newSize)
    val srcLen = fromArray.size
    val dstLen = toArray.size
    var index = 0
    val from = fromArray.unsafeCast<Array<Any?>>()
    val to = toArray.unsafeCast<Array<Any?>>()

    while (index < srcLen && index < dstLen) {
      to[index] = from[index++]
    }

    blackhole.consume(to)
  }

  @Benchmark
  public fun typedArraySet(blackhole: Blackhole) {
    if (newSize > fromArray.size) {
      val toArray = ByteArray(newSize)
      toArray.asDynamic().set(fromArray, 0)
      blackhole.consume(toArray)
    } else {
      val toArray = fromArray.asDynamic().slice(0, newSize)
      blackhole.consume(toArray.unsafeCast<Any>())
    }
  }
}