BitSetFillFactorBenchmark.java

package ru.qwwdfsad.benchmarks;

import org.apache.lucene.util.OpenBitSet;
import org.openjdk.jmh.annotations.*;

import java.util.BitSet;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;

@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@Fork(value = 2, jvmArgs = {"-ea"})
@Warmup(iterations = 5)
@Measurement(iterations = 5)
public class BitSetFillFactorBenchmark {

  private static final ThreadLocalRandom random = ThreadLocalRandom.current();

  @State(Scope.Benchmark)
  public static class BitSetState {

    @Param({"1232896"})
    private int setSize;

    @Param({"0.01", "0.1", "0.5", "1"})
    private double fillFactor;


    BitSet bitSet;
    OpenBitSet openBitSet;

    // To benchmark or/and
    BitSet otherBitSet;
    OpenBitSet otherOpenBitSet;

    @Setup(Level.Iteration)
    public void setup() {
      bitSet = new BitSet(setSize);
      openBitSet = new OpenBitSet(setSize);

      otherBitSet = new BitSet(setSize);
      otherOpenBitSet = new OpenBitSet(setSize);
      // Fill only first fillFactor% of set to show BitSet optimization
      int part = (int) (setSize * fillFactor);
      for (int i = 0; i < part / 2; i++) {
        int nextBit = random.nextInt(part);
        bitSet.set(nextBit);
        openBitSet.set(nextBit);

        nextBit = random.nextInt(part);
        otherBitSet.set(nextBit);
        otherOpenBitSet.set(nextBit);
      }
    }
  }

  /*
   * For following benchmarks state is preserved between
   * invocations, but that shouldn't make any noise in results
   * as long as implementation doesn't check if it should
   * or/and bits
   */

  @Benchmark
  public void andClassic(BitSetState state) {
    state.bitSet.and(state.otherBitSet);
  }

  @Benchmark
  public void andOpen(BitSetState state) {
    state.openBitSet.and(state.otherOpenBitSet);

  }

  @Benchmark
  public void orClassic(BitSetState state) {
    state.bitSet.or(state.otherBitSet);
  }

  @Benchmark
  public void orOpen(BitSetState state) {
    state.openBitSet.or(state.otherOpenBitSet);
  }
}

BitSetFillFactorBenchmarkResults.txt

Benchmark                   (fillFactor)  (setSize)   Mode  Cnt   Score    Error   Units
BitSetBenchmark.andClassic          0.01    1232896  thrpt    5  32.036 ±  1.320  ops/us
BitSetBenchmark.andClassic           0.1    1232896  thrpt    5   3.824 ±  0.896  ops/us
BitSetBenchmark.andClassic           0.5    1232896  thrpt    5   0.330 ±  0.027  ops/us
BitSetBenchmark.andClassic             1    1232896  thrpt    5   0.140 ±  0.017  ops/us
BitSetBenchmark.andOpen             0.01    1232896  thrpt    5   0.142 ±  0.008  ops/us
BitSetBenchmark.andOpen              0.1    1232896  thrpt    5   0.128 ±  0.015  ops/us
BitSetBenchmark.andOpen              0.5    1232896  thrpt    5   0.112 ±  0.015  ops/us
BitSetBenchmark.andOpen                1    1232896  thrpt    5   0.132 ±  0.018  ops/us
BitSetBenchmark.orClassic           0.01    1232896  thrpt    5  27.826 ± 13.312  ops/us
BitSetBenchmark.orClassic            0.1    1232896  thrpt    5   3.727 ±  1.161  ops/us
BitSetBenchmark.orClassic            0.5    1232896  thrpt    5   0.342 ±  0.022  ops/us
BitSetBenchmark.orClassic              1    1232896  thrpt    5   0.133 ±  0.021  ops/us
BitSetBenchmark.orOpen              0.01    1232896  thrpt    5   0.133 ±  0.009  ops/us
BitSetBenchmark.orOpen               0.1    1232896  thrpt    5   0.118 ±  0.007  ops/us
BitSetBenchmark.orOpen               0.5    1232896  thrpt    5   0.127 ±  0.018  ops/us
BitSetBenchmark.orOpen                 1    1232896  thrpt    5   0.148 ±  0.023  ops/us