/*
    * Copyright (C) 2010 The Guava Authors
    *
    * 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 com.google.common.collect;
  
  import static com.google.common.collect.DiscreteDomain.integers;
  
  import com.google.caliper.BeforeExperiment;
  import com.google.caliper.Benchmark;
  import com.google.caliper.Param;
  
  import java.util.Set;
  
  /**
   * Very simple powerSet iteration benchmark.
   *
   * @author Kevin Bourrillion
   */
  public class PowerSetBenchmark {
    @Param({"2", "4", "8", "16"}) int elements;
  
    Set<Set<Integer>> powerSet;
  
    @BeforeExperiment void setUp() {
      Set<Integer> set = ContiguousSet.create(Range.closed(1, elements), integers());
      powerSet = Sets.powerSet(set);
    }
  
    @Benchmark int iteration(int reps) {
      int sum = 0;
      for (int i = 0; i < reps; i++) {
        for (Set<Integer> subset : powerSet) {
          for (Integer value : subset) {
            sum += value;
          }
        }
      }
      return sum;
    }
  }