Array[Byte] Concatenate Benchmark

ByteArrayBench.scala

import java.nio.ByteBuffer
import java.util.concurrent.TimeUnit

import org.openjdk.jmh.annotations._

@State(Scope.Thread)
@BenchmarkMode(Array(Mode.Throughput))
@Warmup(iterations = 10, time = 1)
@Measurement(iterations = 10, time = 1)
@OutputTimeUnit(TimeUnit.SECONDS)
@Fork(2)
class ByteArrayBench {

  val source1: Array[Byte] = (1 to 100).map(_.toByte).toArray
  val source2: Array[Byte] = (1 to 100).map(_.toByte).toArray

  @Benchmark
  def arrayBuilder: Array[Byte] = {
    val b = Array.newBuilder[Byte]
    b.sizeHint(source1.length + source2.length)
    b ++= source1
    b ++= source2
    b.result()
  }

  @Benchmark
  def arrayCopy: Array[Byte] = {
    val dest = Array.ofDim[Byte](source1.length + source2.length)
    java.lang.System.arraycopy(source1, 0, dest, 0, source1.length)
    java.lang.System.arraycopy(source2, 0, dest, source1.length, source1.length)
    dest
  }

  @Benchmark
  def arrayAppend: Array[Byte] = {
    source1 ++ source2
  }

  @Benchmark
  def byteBuffer: ByteBuffer = {
    val s1 = ByteBuffer.wrap(source1)
    val s2 = ByteBuffer.wrap(source2)

    val dest = ByteBuffer.allocate(s1.remaining() + s2.remaining())

    dest.put(s1)
    dest.put(s2)
    dest.flip()
    dest
  }
}

result.log

[info] Benchmark                                                  Mode  Cnt         Score         Error   Units
[info] ArrayBench.arrayAppend                                    thrpt   20   9708780.666 ± 1344125.597   ops/s
[info] ArrayBench.arrayAppend:·gc.alloc.rate                     thrpt   20      1972.252 ±     273.628  MB/sec
[info] ArrayBench.arrayAppend:·gc.alloc.rate.norm                thrpt   20       320.000 ±       0.001    B/op
[info] ArrayBench.arrayAppend:·gc.churn.PS_Eden_Space            thrpt   20      1985.533 ±     279.831  MB/sec
[info] ArrayBench.arrayAppend:·gc.churn.PS_Eden_Space.norm       thrpt   20       322.233 ±       9.895    B/op
[info] ArrayBench.arrayAppend:·gc.churn.PS_Survivor_Space        thrpt   20         0.083 ±       0.033  MB/sec
[info] ArrayBench.arrayAppend:·gc.churn.PS_Survivor_Space.norm   thrpt   20         0.013 ±       0.005    B/op
[info] ArrayBench.arrayAppend:·gc.count                          thrpt   20       278.000                counts
[info] ArrayBench.arrayAppend:·gc.time                           thrpt   20       173.000                    ms
[info] ArrayBench.arrayBuilder                                   thrpt   20    795572.672 ±   21835.642   ops/s
[info] ArrayBench.arrayBuilder:·gc.alloc.rate                    thrpt   20       121.222 ±       3.351  MB/sec
[info] ArrayBench.arrayBuilder:·gc.alloc.rate.norm               thrpt   20       240.002 ±       0.004    B/op
[info] ArrayBench.arrayBuilder:·gc.churn.PS_Eden_Space           thrpt   20       122.448 ±       6.772  MB/sec
[info] ArrayBench.arrayBuilder:·gc.churn.PS_Eden_Space.norm      thrpt   20       242.474 ±      12.114    B/op
[info] ArrayBench.arrayBuilder:·gc.churn.PS_Survivor_Space       thrpt   20         0.052 ±       0.022  MB/sec
[info] ArrayBench.arrayBuilder:·gc.churn.PS_Survivor_Space.norm  thrpt   20         0.103 ±       0.046    B/op
[info] ArrayBench.arrayBuilder:·gc.count                         thrpt   20       116.000                counts
[info] ArrayBench.arrayBuilder:·gc.time                          thrpt   20        62.000                    ms
[info] ArrayBench.arrayCopy                                      thrpt   20  23068792.759 ±  926859.198   ops/s
[info] ArrayBench.arrayCopy:·gc.alloc.rate                       thrpt   20      3163.978 ±     128.644  MB/sec
[info] ArrayBench.arrayCopy:·gc.alloc.rate.norm                  thrpt   20       216.000 ±       0.001    B/op
[info] ArrayBench.arrayCopy:·gc.churn.PS_Eden_Space              thrpt   20      3165.939 ±     166.427  MB/sec
[info] ArrayBench.arrayCopy:·gc.churn.PS_Eden_Space.norm         thrpt   20       216.100 ±       6.547    B/op
[info] ArrayBench.arrayCopy:·gc.churn.PS_Survivor_Space          thrpt   20         0.058 ±       0.022  MB/sec
[info] ArrayBench.arrayCopy:·gc.churn.PS_Survivor_Space.norm     thrpt   20         0.004 ±       0.002    B/op
[info] ArrayBench.arrayCopy:·gc.count                            thrpt   20       326.000                counts
[info] ArrayBench.arrayCopy:·gc.time                             thrpt   20       183.000                    ms
[info] ArrayBench.byteBuffer                                     thrpt   20  20291680.952 ±  536843.080   ops/s
[info] ArrayBench.byteBuffer:·gc.alloc.rate                      thrpt   20      3400.674 ±      90.675  MB/sec
[info] ArrayBench.byteBuffer:·gc.alloc.rate.norm                 thrpt   20       264.000 ±       0.001    B/op
[info] ArrayBench.byteBuffer:·gc.churn.PS_Eden_Space             thrpt   20      3398.325 ±     151.210  MB/sec
[info] ArrayBench.byteBuffer:·gc.churn.PS_Eden_Space.norm        thrpt   20       263.732 ±       7.316    B/op
[info] ArrayBench.byteBuffer:·gc.churn.PS_Survivor_Space         thrpt   20         0.112 ±       0.041  MB/sec
[info] ArrayBench.byteBuffer:·gc.churn.PS_Survivor_Space.norm    thrpt   20         0.009 ±       0.003    B/op
[info] ArrayBench.byteBuffer:·gc.count                           thrpt   20       313.000                counts
[info] ArrayBench.byteBuffer:·gc.time                            thrpt   20       173.000                    ms