DistinctTest.java

import java.util.concurrent.TimeUnit;
import javax.util.streamex.*;
import java.util.stream.*;
import java.util.function.*;
import java.util.*;

import org.openjdk.jmh.infra.Blackhole;
import org.openjdk.jmh.annotations.*;

@Warmup(iterations = 5, time = 500, timeUnit = TimeUnit.MILLISECONDS)
@Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@Fork(2)
@State(Scope.Benchmark)
public class DistinctTest {
    @Param({ "100", "10000", "1000000" })
    private int n;
    @Param({ "2", "4" })
    private int k;
    @Param({ "distinct", "few", "many", "sorted", "withnulls" })
    private String profile;

    private List<Integer> input;

    @Setup
    public void setUp() {
        switch(profile) {
        case "distinct":
            input = IntStreamEx.of(new Random(1), n*2).boxed().distinct().limit(n).toList();
            break;
        case "few":
            input = IntStreamEx.of(new Random(1), n, 0, n*3).boxed().toList();
            break;
        case "many":
            input = IntStreamEx.of(new Random(1), n, 0, n/50).boxed().toList();
            break;
        case "sorted":
            input = IntStreamEx.of(new Random(1), n, 0, n/3).boxed().sorted().toList();
            break;
        case "withnulls":
            input = IntStreamEx.of(new Random(1), n, 0, n/3).boxed().map(i -> i < n/10 ? null : i).toList();
            break;
        }
    }

    @Benchmark
    public void distinct(Blackhole bh) {
        bh.consume(StreamEx.of(input).distinct(k).toSet());
    }

    @Benchmark
    public void distinct2(Blackhole bh) {
        bh.consume(StreamEx.of(input).distinct2(k).toSet());
    }

    @Benchmark
    public void distinctParallel(Blackhole bh) {
        bh.consume(StreamEx.of(input).parallel().distinct(k).toSet());
    }

    @Benchmark
    public void distinct2Parallel(Blackhole bh) {
        bh.consume(StreamEx.of(input).parallel().distinct2(k).toSet());
    }

    @Benchmark
    public void removeIf(Blackhole bh) {
        bh.consume(input.stream().collect(
                        Collectors.collectingAndThen(Collectors.groupingBy(Function.identity(), Collectors.counting()), m -> {
                            m.values().removeIf(l -> l < k);
                            return m.keySet();
                        })));
    }

    @Benchmark
    public void removeIfParallel(Blackhole bh) {
        bh.consume(input.stream().parallel().collect(
                        Collectors.collectingAndThen(Collectors.groupingBy(Function.identity(), Collectors.counting()), m -> {
                            m.values().removeIf(l -> l < k);
                            return m.keySet();
                        })));
    }

    @Benchmark
    public void doubleStream(Blackhole bh) {
        bh.consume(input.stream().collect(Collectors.groupingBy(Function.identity(), Collectors.counting()))
                 .entrySet().stream().filter(e -> e.getValue() >= k).map(e -> e.getKey()).collect(Collectors.toSet()));
    }

    @Benchmark
    public void doubleStreamParallel(Blackhole bh) {
        bh.consume(input.stream().parallel().collect(Collectors.groupingBy(Function.identity(), Collectors.counting()))
                 .entrySet().stream().parallel().filter(e -> e.getValue() >= k).map(e -> e.getKey())
                 .collect(Collectors.toSet()));
    }
}

rawresults.txt

# JMH 1.9 (released 42 days ago)
# VM invoker: C:\Program Files\Java\jre1.9.0\bin\java.exe
# VM options: <none>
...
# Run complete. Total time: 01:00:24

Benchmark                          (k)      (n)  (profile)  Mode  Cnt       Score       Error  Units
DistinctTest.distinct                2      100   distinct  avgt   20      10.076 ±     0.707  us/op
DistinctTest.distinct                2      100        few  avgt   20       6.505 ±     0.454  us/op
DistinctTest.distinct                2      100       many  avgt   20       2.480 ±     0.366  us/op
DistinctTest.distinct                2      100     sorted  avgt   20       4.435 ±     0.416  us/op
DistinctTest.distinct                2      100  withnulls  avgt   20       3.071 ±     0.305  us/op
DistinctTest.distinct                2    10000   distinct  avgt   20     862.703 ±     7.279  us/op
DistinctTest.distinct                2    10000        few  avgt   20     989.554 ±    26.188  us/op
DistinctTest.distinct                2    10000       many  avgt   20     325.408 ±    34.653  us/op
DistinctTest.distinct                2    10000     sorted  avgt   20     518.308 ±    39.317  us/op
DistinctTest.distinct                2    10000  withnulls  avgt   20     493.513 ±     8.385  us/op
DistinctTest.distinct                2  1000000   distinct  avgt   20  272627.108 ± 22561.109  us/op
DistinctTest.distinct                2  1000000        few  avgt   20  275581.769 ±  8012.608  us/op
DistinctTest.distinct                2  1000000       many  avgt   20   44797.018 ±  3141.061  us/op
DistinctTest.distinct                2  1000000     sorted  avgt   20   48971.547 ±  2462.198  us/op
DistinctTest.distinct                2  1000000  withnulls  avgt   20  127426.192 ±  3134.266  us/op
DistinctTest.distinct                4      100   distinct  avgt   20      10.091 ±     0.712  us/op
DistinctTest.distinct                4      100        few  avgt   20       6.306 ±     0.449  us/op
DistinctTest.distinct                4      100       many  avgt   20       2.452 ±     0.343  us/op
DistinctTest.distinct                4      100     sorted  avgt   20       4.157 ±     0.430  us/op
DistinctTest.distinct                4      100  withnulls  avgt   20       3.029 ±     0.322  us/op
DistinctTest.distinct                4    10000   distinct  avgt   20     857.569 ±     5.606  us/op
DistinctTest.distinct                4    10000        few  avgt   20     866.982 ±     2.292  us/op
DistinctTest.distinct                4    10000       many  avgt   20     317.067 ±    39.232  us/op
DistinctTest.distinct                4    10000     sorted  avgt   20     514.381 ±    46.452  us/op
DistinctTest.distinct                4    10000  withnulls  avgt   20     453.092 ±     4.472  us/op
DistinctTest.distinct                4  1000000   distinct  avgt   20  263676.479 ±  8413.303  us/op
DistinctTest.distinct                4  1000000        few  avgt   20  247033.407 ±  5212.887  us/op
DistinctTest.distinct                4  1000000       many  avgt   20   43873.780 ±  3201.061  us/op
DistinctTest.distinct                4  1000000     sorted  avgt   20   46622.925 ±  2618.410  us/op
DistinctTest.distinct                4  1000000  withnulls  avgt   20  109429.434 ±  2231.328  us/op
DistinctTest.distinct2               2      100   distinct  avgt   20       2.426 ±     0.027  us/op
DistinctTest.distinct2               2      100        few  avgt   20       2.342 ±     0.010  us/op
DistinctTest.distinct2               2      100       many  avgt   20       1.717 ±     0.005  us/op
DistinctTest.distinct2               2      100     sorted  avgt   20       2.426 ±     0.014  us/op
DistinctTest.distinct2               2      100  withnulls  avgt   20       1.996 ±     0.013  us/op
DistinctTest.distinct2               2    10000   distinct  avgt   20     405.112 ±     3.743  us/op
DistinctTest.distinct2               2    10000        few  avgt   20     493.997 ±     1.463  us/op
DistinctTest.distinct2               2    10000       many  avgt   20     234.610 ±     1.045  us/op
DistinctTest.distinct2               2    10000     sorted  avgt   20     278.096 ±     0.783  us/op
DistinctTest.distinct2               2    10000  withnulls  avgt   20     350.004 ±     0.663  us/op
DistinctTest.distinct2               2  1000000   distinct  avgt   20  180560.561 ±  6924.590  us/op
DistinctTest.distinct2               2  1000000        few  avgt   20  202522.457 ±  5445.315  us/op
DistinctTest.distinct2               2  1000000       many  avgt   20   35725.085 ±  1675.569  us/op
DistinctTest.distinct2               2  1000000     sorted  avgt   20   32661.395 ±   651.902  us/op
DistinctTest.distinct2               2  1000000  withnulls  avgt   20  123620.698 ± 11722.027  us/op
DistinctTest.distinct2               4      100   distinct  avgt   20       2.427 ±     0.022  us/op
DistinctTest.distinct2               4      100        few  avgt   20       1.980 ±     0.009  us/op
DistinctTest.distinct2               4      100       many  avgt   20       1.716 ±     0.004  us/op
DistinctTest.distinct2               4      100     sorted  avgt   20       2.218 ±     0.018  us/op
DistinctTest.distinct2               4      100  withnulls  avgt   20       1.883 ±     0.010  us/op
DistinctTest.distinct2               4    10000   distinct  avgt   20     409.476 ±     0.764  us/op
DistinctTest.distinct2               4    10000        few  avgt   20     431.062 ±     1.121  us/op
DistinctTest.distinct2               4    10000       many  avgt   20     238.471 ±     0.502  us/op
DistinctTest.distinct2               4    10000     sorted  avgt   20     265.066 ±     4.045  us/op
DistinctTest.distinct2               4    10000  withnulls  avgt   20     311.112 ±     2.412  us/op
DistinctTest.distinct2               4  1000000   distinct  avgt   20  177993.057 ±  5737.694  us/op
DistinctTest.distinct2               4  1000000        few  avgt   20  187580.324 ±  2032.904  us/op
DistinctTest.distinct2               4  1000000       many  avgt   20   35414.346 ±  1489.152  us/op
DistinctTest.distinct2               4  1000000     sorted  avgt   20   31047.504 ±   326.305  us/op
DistinctTest.distinct2               4  1000000  withnulls  avgt   20  107941.419 ±  1642.979  us/op
DistinctTest.distinct2Parallel       2      100   distinct  avgt   20      20.509 ±     0.655  us/op
DistinctTest.distinct2Parallel       2      100        few  avgt   20      18.130 ±     0.481  us/op
DistinctTest.distinct2Parallel       2      100       many  avgt   20      17.524 ±     0.280  us/op
DistinctTest.distinct2Parallel       2      100     sorted  avgt   20      11.909 ±     0.200  us/op
DistinctTest.distinct2Parallel       2      100  withnulls  avgt   20       9.849 ±     0.316  us/op
DistinctTest.distinct2Parallel       2    10000   distinct  avgt   20     711.803 ±     9.197  us/op
DistinctTest.distinct2Parallel       2    10000        few  avgt   20     805.113 ±     9.221  us/op
DistinctTest.distinct2Parallel       2    10000       many  avgt   20     287.951 ±     5.080  us/op
DistinctTest.distinct2Parallel       2    10000     sorted  avgt   20     349.457 ±     1.975  us/op
DistinctTest.distinct2Parallel       2    10000  withnulls  avgt   20     442.185 ±     3.532  us/op
DistinctTest.distinct2Parallel       2  1000000   distinct  avgt   20   84722.555 ±  1663.882  us/op
DistinctTest.distinct2Parallel       2  1000000        few  avgt   20  115307.445 ±  4861.937  us/op
DistinctTest.distinct2Parallel       2  1000000       many  avgt   20   24850.287 ±   296.845  us/op
DistinctTest.distinct2Parallel       2  1000000     sorted  avgt   20   38884.098 ±  1331.486  us/op
DistinctTest.distinct2Parallel       2  1000000  withnulls  avgt   20   70291.310 ±  1638.556  us/op
DistinctTest.distinct2Parallel       4      100   distinct  avgt   20      20.680 ±     0.843  us/op
DistinctTest.distinct2Parallel       4      100        few  avgt   20      17.265 ±     0.495  us/op
DistinctTest.distinct2Parallel       4      100       many  avgt   20      17.733 ±     0.293  us/op
DistinctTest.distinct2Parallel       4      100     sorted  avgt   20      11.569 ±     0.248  us/op
DistinctTest.distinct2Parallel       4      100  withnulls  avgt   20       9.673 ±     0.233  us/op
DistinctTest.distinct2Parallel       4    10000   distinct  avgt   20     711.795 ±    10.728  us/op
DistinctTest.distinct2Parallel       4    10000        few  avgt   20     705.210 ±    15.654  us/op
DistinctTest.distinct2Parallel       4    10000       many  avgt   20     288.444 ±     2.685  us/op
DistinctTest.distinct2Parallel       4    10000     sorted  avgt   20     321.868 ±     4.717  us/op
DistinctTest.distinct2Parallel       4    10000  withnulls  avgt   20     379.891 ±     8.331  us/op
DistinctTest.distinct2Parallel       4  1000000   distinct  avgt   20   88958.429 ±  4647.219  us/op
DistinctTest.distinct2Parallel       4  1000000        few  avgt   20   83954.803 ±  2336.181  us/op
DistinctTest.distinct2Parallel       4  1000000       many  avgt   20   25665.085 ±  1324.138  us/op
DistinctTest.distinct2Parallel       4  1000000     sorted  avgt   20   33023.539 ±  1016.088  us/op
DistinctTest.distinct2Parallel       4  1000000  withnulls  avgt   20   48519.962 ±  1402.775  us/op
DistinctTest.distinctParallel        2      100   distinct  avgt   20      20.999 ±     1.341  us/op
DistinctTest.distinctParallel        2      100        few  avgt   20      18.023 ±     0.298  us/op
DistinctTest.distinctParallel        2      100       many  avgt   20      17.466 ±     0.287  us/op
DistinctTest.distinctParallel        2      100     sorted  avgt   20      12.062 ±     0.240  us/op
DistinctTest.distinctParallel        2      100  withnulls  avgt   20       9.908 ±     0.185  us/op
DistinctTest.distinctParallel        2    10000   distinct  avgt   20     696.101 ±     5.631  us/op
DistinctTest.distinctParallel        2    10000        few  avgt   20     810.674 ±    12.759  us/op
DistinctTest.distinctParallel        2    10000       many  avgt   20     289.943 ±     3.148  us/op
DistinctTest.distinctParallel        2    10000     sorted  avgt   20     340.911 ±     3.259  us/op
DistinctTest.distinctParallel        2    10000  withnulls  avgt   20     426.310 ±     2.989  us/op
DistinctTest.distinctParallel        2  1000000   distinct  avgt   20   93505.549 ±  6982.900  us/op
DistinctTest.distinctParallel        2  1000000        few  avgt   20  117612.706 ±  5353.843  us/op
DistinctTest.distinctParallel        2  1000000       many  avgt   20   22039.303 ±   406.431  us/op
DistinctTest.distinctParallel        2  1000000     sorted  avgt   20   38088.294 ±  1440.017  us/op
DistinctTest.distinctParallel        2  1000000  withnulls  avgt   20   73036.837 ±  4027.681  us/op
DistinctTest.distinctParallel        4      100   distinct  avgt   20      20.429 ±     0.700  us/op
DistinctTest.distinctParallel        4      100        few  avgt   20      17.273 ±     0.524  us/op
DistinctTest.distinctParallel        4      100       many  avgt   20      17.867 ±     0.986  us/op
DistinctTest.distinctParallel        4      100     sorted  avgt   20      11.636 ±     0.264  us/op
DistinctTest.distinctParallel        4      100  withnulls  avgt   20       9.702 ±     0.223  us/op
DistinctTest.distinctParallel        4    10000   distinct  avgt   20     717.174 ±    11.273  us/op
DistinctTest.distinctParallel        4    10000        few  avgt   20     685.210 ±     3.885  us/op
DistinctTest.distinctParallel        4    10000       many  avgt   20     291.187 ±     5.435  us/op
DistinctTest.distinctParallel        4    10000     sorted  avgt   20     321.330 ±     5.761  us/op
DistinctTest.distinctParallel        4    10000  withnulls  avgt   20     371.898 ±     1.292  us/op
DistinctTest.distinctParallel        4  1000000   distinct  avgt   20   90384.072 ±  8515.771  us/op
DistinctTest.distinctParallel        4  1000000        few  avgt   20   85288.065 ±  3161.993  us/op
DistinctTest.distinctParallel        4  1000000       many  avgt   20   22583.471 ±   699.742  us/op
DistinctTest.distinctParallel        4  1000000     sorted  avgt   20   32784.937 ±   915.522  us/op
DistinctTest.distinctParallel        4  1000000  withnulls  avgt   20   47008.062 ±  1082.374  us/op
DistinctTest.doubleStream            2      100   distinct  avgt   20       4.095 ±     0.064  us/op
DistinctTest.doubleStream            2      100        few  avgt   20       3.925 ±     0.098  us/op
DistinctTest.doubleStream            2      100       many  avgt   20       2.054 ±     0.007  us/op
DistinctTest.doubleStream            2      100     sorted  avgt   20       3.039 ±     0.023  us/op
DistinctTest.doubleStream            2    10000   distinct  avgt   20     796.422 ±     3.384  us/op
DistinctTest.doubleStream            2    10000        few  avgt   20     878.811 ±     7.690  us/op
DistinctTest.doubleStream            2    10000       many  avgt   20     239.245 ±     4.190  us/op
DistinctTest.doubleStream            2    10000     sorted  avgt   20     359.577 ±    13.838  us/op
DistinctTest.doubleStream            2  1000000   distinct  avgt   20  297502.091 ±  6341.697  us/op
DistinctTest.doubleStream            2  1000000        few  avgt   20  318173.650 ± 12241.314  us/op
DistinctTest.doubleStream            2  1000000       many  avgt   20   37241.274 ±  1765.361  us/op
DistinctTest.doubleStream            2  1000000     sorted  avgt   20   42295.708 ±   483.627  us/op
DistinctTest.doubleStream            4      100   distinct  avgt   20       4.162 ±     0.119  us/op
DistinctTest.doubleStream            4      100        few  avgt   20       3.366 ±     0.050  us/op
DistinctTest.doubleStream            4      100       many  avgt   20       2.071 ±     0.025  us/op
DistinctTest.doubleStream            4      100     sorted  avgt   20       2.859 ±     0.029  us/op
DistinctTest.doubleStream            4    10000   distinct  avgt   20     792.121 ±    11.065  us/op
DistinctTest.doubleStream            4    10000        few  avgt   20     802.714 ±     3.399  us/op
DistinctTest.doubleStream            4    10000       many  avgt   20     226.410 ±     0.515  us/op
DistinctTest.doubleStream            4    10000     sorted  avgt   20     344.411 ±     3.103  us/op
DistinctTest.doubleStream            4  1000000   distinct  avgt   20  299257.530 ±  8392.674  us/op
DistinctTest.doubleStream            4  1000000        few  avgt   20  298183.049 ±  4541.512  us/op
DistinctTest.doubleStream            4  1000000       many  avgt   20   35402.361 ±   342.813  us/op
DistinctTest.doubleStream            4  1000000     sorted  avgt   20   40211.781 ±   426.403  us/op
DistinctTest.doubleStreamParallel    2      100   distinct  avgt   20      16.478 ±     0.126  us/op
DistinctTest.doubleStreamParallel    2      100        few  avgt   20      15.994 ±     0.338  us/op
DistinctTest.doubleStreamParallel    2      100       many  avgt   20       9.167 ±     0.468  us/op
DistinctTest.doubleStreamParallel    2      100     sorted  avgt   20      13.048 ±     0.128  us/op
DistinctTest.doubleStreamParallel    2    10000   distinct  avgt   20     942.248 ±    14.524  us/op
DistinctTest.doubleStreamParallel    2    10000        few  avgt   20     985.931 ±     5.406  us/op
DistinctTest.doubleStreamParallel    2    10000       many  avgt   20     132.838 ±     0.939  us/op
DistinctTest.doubleStreamParallel    2    10000     sorted  avgt   20     303.148 ±     2.546  us/op
DistinctTest.doubleStreamParallel    2  1000000   distinct  avgt   20  294226.521 ± 15303.996  us/op
DistinctTest.doubleStreamParallel    2  1000000        few  avgt   20  336986.741 ± 13510.120  us/op
DistinctTest.doubleStreamParallel    2  1000000       many  avgt   20   35760.574 ±   638.865  us/op
DistinctTest.doubleStreamParallel    2  1000000     sorted  avgt   20   41899.403 ±   741.789  us/op
DistinctTest.doubleStreamParallel    4      100   distinct  avgt   20      16.196 ±     0.147  us/op
DistinctTest.doubleStreamParallel    4      100        few  avgt   20      15.647 ±     0.129  us/op
DistinctTest.doubleStreamParallel    4      100       many  avgt   20       9.162 ±     0.525  us/op
DistinctTest.doubleStreamParallel    4      100     sorted  avgt   20      12.773 ±     0.147  us/op
DistinctTest.doubleStreamParallel    4    10000   distinct  avgt   20     922.054 ±    13.214  us/op
DistinctTest.doubleStreamParallel    4    10000        few  avgt   20     908.412 ±    15.561  us/op
DistinctTest.doubleStreamParallel    4    10000       many  avgt   20     133.203 ±     0.578  us/op
DistinctTest.doubleStreamParallel    4    10000     sorted  avgt   20     273.842 ±     5.564  us/op
DistinctTest.doubleStreamParallel    4  1000000   distinct  avgt   20  297903.511 ± 12926.636  us/op
DistinctTest.doubleStreamParallel    4  1000000        few  avgt   20  306296.716 ±  7673.998  us/op
DistinctTest.doubleStreamParallel    4  1000000       many  avgt   20   36334.204 ±   458.981  us/op
DistinctTest.doubleStreamParallel    4  1000000     sorted  avgt   20   36112.794 ±   930.054  us/op
DistinctTest.removeIf                2      100   distinct  avgt   20       4.602 ±     0.033  us/op
DistinctTest.removeIf                2      100        few  avgt   20       3.695 ±     0.013  us/op
DistinctTest.removeIf                2      100       many  avgt   20       1.908 ±     0.007  us/op
DistinctTest.removeIf                2      100     sorted  avgt   20       2.323 ±     0.014  us/op
DistinctTest.removeIf                2    10000   distinct  avgt   20     861.065 ±     7.552  us/op
DistinctTest.removeIf                2    10000        few  avgt   20     821.471 ±     6.357  us/op
DistinctTest.removeIf                2    10000       many  avgt   20     213.615 ±     0.886  us/op
DistinctTest.removeIf                2    10000     sorted  avgt   20     274.142 ±     0.655  us/op
DistinctTest.removeIf                2  1000000   distinct  avgt   20  414877.809 ± 14113.968  us/op
DistinctTest.removeIf                2  1000000        few  avgt   20  384176.577 ± 16784.865  us/op
DistinctTest.removeIf                2  1000000       many  avgt   20   34567.374 ±   206.696  us/op
DistinctTest.removeIf                2  1000000     sorted  avgt   20   34367.381 ±   404.604  us/op
DistinctTest.removeIf                4      100   distinct  avgt   20       4.575 ±     0.033  us/op
DistinctTest.removeIf                4      100        few  avgt   20       3.626 ±     0.008  us/op
DistinctTest.removeIf                4      100       many  avgt   20       1.904 ±     0.004  us/op
DistinctTest.removeIf                4      100     sorted  avgt   20       2.442 ±     0.036  us/op
DistinctTest.removeIf                4    10000   distinct  avgt   20     859.452 ±     4.828  us/op
DistinctTest.removeIf                4    10000        few  avgt   20     804.396 ±     7.711  us/op
DistinctTest.removeIf                4    10000       many  avgt   20     211.545 ±     0.836  us/op
DistinctTest.removeIf                4    10000     sorted  avgt   20     301.254 ±     5.309  us/op
DistinctTest.removeIf                4  1000000   distinct  avgt   20  410370.939 ± 12232.423  us/op
DistinctTest.removeIf                4  1000000        few  avgt   20  386061.753 ± 12803.511  us/op
DistinctTest.removeIf                4  1000000       many  avgt   20   34664.094 ±   182.680  us/op
DistinctTest.removeIf                4  1000000     sorted  avgt   20   36208.008 ±   459.616  us/op
DistinctTest.removeIfParallel        2      100   distinct  avgt   20      11.891 ±     0.091  us/op
DistinctTest.removeIfParallel        2      100        few  avgt   20      11.277 ±     0.167  us/op
DistinctTest.removeIfParallel        2      100       many  avgt   20       6.196 ±     0.052  us/op
DistinctTest.removeIfParallel        2      100     sorted  avgt   20       7.514 ±     0.066  us/op
DistinctTest.removeIfParallel        2    10000   distinct  avgt   20    1107.195 ±     5.964  us/op
DistinctTest.removeIfParallel        2    10000        few  avgt   20    1060.832 ±     5.002  us/op
DistinctTest.removeIfParallel        2    10000       many  avgt   20     127.793 ±     1.925  us/op
DistinctTest.removeIfParallel        2    10000     sorted  avgt   20     214.446 ±     2.905  us/op
DistinctTest.removeIfParallel        2  1000000   distinct  avgt   20  362844.116 ±  9572.428  us/op
DistinctTest.removeIfParallel        2  1000000        few  avgt   20  371892.016 ±  9150.527  us/op
DistinctTest.removeIfParallel        2  1000000       many  avgt   20   34755.349 ±   278.747  us/op
DistinctTest.removeIfParallel        2  1000000     sorted  avgt   20   29565.659 ±   748.929  us/op
DistinctTest.removeIfParallel        4      100   distinct  avgt   20      11.746 ±     0.077  us/op
DistinctTest.removeIfParallel        4      100        few  avgt   20      11.106 ±     0.134  us/op
DistinctTest.removeIfParallel        4      100       many  avgt   20       6.203 ±     0.074  us/op
DistinctTest.removeIfParallel        4      100     sorted  avgt   20       7.703 ±     0.196  us/op
DistinctTest.removeIfParallel        4    10000   distinct  avgt   20    1100.511 ±     7.610  us/op
DistinctTest.removeIfParallel        4    10000        few  avgt   20    1069.192 ±    25.016  us/op
DistinctTest.removeIfParallel        4    10000       many  avgt   20     126.637 ±     1.378  us/op
DistinctTest.removeIfParallel        4    10000     sorted  avgt   20     235.656 ±     2.833  us/op
DistinctTest.removeIfParallel        4  1000000   distinct  avgt   20  362334.487 ±  7654.813  us/op
DistinctTest.removeIfParallel        4  1000000        few  avgt   20  389090.919 ± 12011.139  us/op
DistinctTest.removeIfParallel        4  1000000       many  avgt   20   34483.254 ±   289.400  us/op
DistinctTest.removeIfParallel        4  1000000     sorted  avgt   20   33013.028 ±  2905.069  us/op

table.txt

                     |Sequential                                 |Parallel
(k)     (n) (profile)|spliterator    filter two-streams remove-if|spliterator    filter two-streams remove-if
-------------------------------------------------------------------------------------------------------------
  2     100 distinct |       2.43     10.08        4.10      4.60|      20.51     21.00       16.48     11.89
  4     100 distinct |       2.43     10.09        4.16      4.58|      20.68     20.43       16.20     11.75
  2   10000 distinct |     405.11    862.70      796.42    861.07|     711.80    696.10      942.25   1107.20
  4   10000 distinct |     409.48    857.57      792.12    859.45|     711.80    717.17      922.05   1100.51
  2 1000000 distinct |  180560.56 272627.11   297502.09 414877.81|   84722.56  93505.55   294226.52 362844.12
  4 1000000 distinct |  177993.06 263676.48   299257.53 410370.94|   88958.43  90384.07   297903.51 362334.49
  2     100 few      |       2.34      6.51        3.93      3.70|      18.13     18.02       15.99     11.28
  4     100 few      |       1.98      6.31        3.37      3.63|      17.27     17.27       15.65     11.11
  2   10000 few      |     494.00    989.55      878.81    821.47|     805.11    810.67      985.93   1060.83
  4   10000 few      |     431.06    866.98      802.71    804.40|     705.21    685.21      908.41   1069.19
  2 1000000 few      |  202522.46 275581.77   318173.65 384176.58|  115307.45 117612.71   336986.74 371892.02
  4 1000000 few      |  187580.32 247033.41   298183.05 386061.75|   83954.80  85288.07   306296.72 389090.92
  2     100 many     |       1.72      2.48        2.05      1.91|      17.52     17.47        9.17      6.20
  4     100 many     |       1.72      2.45        2.07      1.90|      17.73     17.87        9.16      6.20
  2   10000 many     |     234.61    325.41      239.25    213.62|     287.95    289.94      132.84    127.79
  4   10000 many     |     238.47    317.07      226.41    211.55|     288.44    291.19      133.20    126.64
  2 1000000 many     |   35725.09  44797.02    37241.27  34567.37|   24850.29  22039.30    35760.57  34755.35
  4 1000000 many     |   35414.35  43873.78    35402.36  34664.09|   25665.09  22583.47    36334.20  34483.25
  2     100 sorted   |       2.43      4.44        3.04      2.32|      11.91     12.06       13.05      7.51
  4     100 sorted   |       2.22      4.16        2.86      2.44|      11.57     11.64       12.77      7.70
  2   10000 sorted   |     278.10    518.31      359.58    274.14|     349.46    340.91      303.15    214.45
  4   10000 sorted   |     265.07    514.38      344.41    301.25|     321.87    321.33      273.84    235.66
  2 1000000 sorted   |   32661.40  48971.55    42295.71  34367.38|   38884.10  38088.29    41899.40  29565.66
  4 1000000 sorted   |   31047.50  46622.93    40211.78  36208.01|   33023.54  32784.94    36112.79  33013.03
  2     100 withnulls|       2.00      3.07                      |       9.85      9.91
  4     100 withnulls|       1.88      3.03                      |       9.67      9.70
  2   10000 withnulls|     350.00    493.51                      |     442.19    426.31
  4   10000 withnulls|     311.11    453.09                      |     379.89    371.90
  2 1000000 withnulls|  123620.70 127426.19                      |   70291.31  73036.84
  4 1000000 withnulls|  107941.42 109429.43                      |   48519.96  47008.06
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