/*
    * Copyright (C) 2011 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 com.google.caliper.BeforeExperiment;
  import com.google.caliper.Benchmark;
  import com.google.common.collect.HashMultiset;
  import com.google.common.collect.Multiset;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Random;
  
  /**
   * Benchmark for HashMultiset.add for an already-present element.
   *
   * @author Louis Wasserman
   */
  public class HashMultisetAddPresentBenchmark {
    private static final int ARRAY_MASK = 0x0ffff;
    private static final int ARRAY_SIZE = 0x10000;
    List<Multiset<Integer>> multisets = new ArrayList<Multiset<Integer>>(0x10000);
    int[] queries = new int[ARRAY_SIZE];
  
    @BeforeExperiment
    void setUp() {
      Random random = new Random();
      multisets.clear();
      for (int i = 0; i < ARRAY_SIZE; i++) {
        HashMultiset<Integer> multiset = HashMultiset.<Integer>create();
        multisets.add(multiset);
        queries[i] = random.nextInt();
        multiset.add(queries[i]);
      }
    }
  
    @Benchmark int add(int reps) {
      int tmp = 0;
      for (int i = 0; i < reps; i++) {
        int j = i & ARRAY_MASK;
        tmp += multisets.get(j).add(queries[j], 4);
      }
      return tmp;
    }
  }