content: /*
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package io.airlift.stats.cardinality;
  
  import org.openjdk.jmh.annotations.Benchmark;
  import org.openjdk.jmh.annotations.BenchmarkMode;
  import org.openjdk.jmh.annotations.Fork;
  import org.openjdk.jmh.annotations.Level;
  import org.openjdk.jmh.annotations.Measurement;
  import org.openjdk.jmh.annotations.Mode;
  import org.openjdk.jmh.annotations.OutputTimeUnit;
  import org.openjdk.jmh.annotations.Scope;
  import org.openjdk.jmh.annotations.Setup;
  import org.openjdk.jmh.annotations.State;
  import org.openjdk.jmh.annotations.Warmup;
  import org.openjdk.jmh.runner.Runner;
  import org.openjdk.jmh.runner.RunnerException;
  import org.openjdk.jmh.runner.options.Options;
  import org.openjdk.jmh.runner.options.OptionsBuilder;
  import org.openjdk.jmh.runner.options.VerboseMode;
  
  import java.util.concurrent.ThreadLocalRandom;
  import java.util.concurrent.TimeUnit;
  
  @State(Scope.Thread)
  @OutputTimeUnit(TimeUnit.MICROSECONDS)
  @BenchmarkMode(Mode.AverageTime)
  @Fork(5)
  @Warmup(iterations = 5, time = 500, timeUnit = TimeUnit.MILLISECONDS)
  @Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)
  public class BenchmarkDenseHll
  {
      private static final int LARGE_CARDINALITY = 1_000_000;
      private static final int SMALL_CARDINALITY = 100;
  
      @Benchmark
      public DenseHll benchmarkInsert(InsertData data)
      {
          for (long hash : data.hashes) {
              data.instance.insertHash(hash);
          }
  
          return data.instance;
      }
  
      @Benchmark
      public DenseHll benchmarkMergeWithDense(MergeWithDenseData data)
      {
          return data.base.mergeWith(data.toMerge);
      }
  
      @Benchmark
      public DenseHll benchmarkMergeWithSparse(MergeWithSparseData data)
      {
          return data.base.mergeWith(data.toMerge);
      }
  
      @State(Scope.Thread)
      public static class InsertData
      {
          public final DenseHll instance = new DenseHll(12);
          public final long[] hashes = new long[500];
  
          @Setup(Level.Iteration)
          public void initialize()
          {
              for (int i = 0; i < hashes.length; i++) {
                  hashes[i] = ThreadLocalRandom.current().nextLong();
              }
          }
      }
  
      @State(Scope.Thread)
      public static class MergeWithDenseData
      {
          public DenseHll base;
          public DenseHll toMerge;
  
          @Setup(Level.Iteration)
          public void initialize()
          {
              base = new DenseHll(12);
              for (int i = 0; i < LARGE_CARDINALITY; i++) {
                  base.insertHash(ThreadLocalRandom.current().nextLong());
              }
  
              // Small cardinality so we can do an apples-to-apples comparison
              // between dense/dense vs dense/sparse merge. Sparse only supports
              // small cardinalities.
              toMerge = new DenseHll(12);
              for (int i = 0; i < SMALL_CARDINALITY; i++) {
                  toMerge.insertHash(ThreadLocalRandom.current().nextLong());
              }
          }
      }
  
      @State(Scope.Thread)
      public static class MergeWithSparseData
      {
          public DenseHll base;
          public SparseHll toMerge;
  
          @Setup(Level.Iteration)
          public void initialize()
          {
              base = new DenseHll(12);
              for (int i = 0; i < LARGE_CARDINALITY; i++) {
                  base.insertHash(ThreadLocalRandom.current().nextLong());
              }
  
              toMerge = new SparseHll(12);
              for (int i = 0; i < SMALL_CARDINALITY; i++) {
                  toMerge.insertHash(ThreadLocalRandom.current().nextLong());
              }
          }
      }
  
      public static void main(String[] args)
              throws RunnerException
      {
          Options options = new OptionsBuilder()
                  .verbosity(VerboseMode.NORMAL)
                  .include(".*" + BenchmarkDenseHll.class.getSimpleName() + ".*")
                  .build();
  
          new Runner(options).run();
      }
  }
  