1   /*
2    * Copyright (C) 2012 The Guava Authors
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    * http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package com.google.common.collect;
18  
19  import com.google.caliper.BeforeExperiment;
20  import com.google.caliper.Benchmark;
21  import com.google.caliper.Param;
22  import com.google.common.collect.BenchmarkHelpers.SetImpl;
23  import com.google.common.collect.CollectionBenchmarkSampleData.Element;
24  
25  import java.util.Set;
26  
27  /**
28   * Test iteration speed at various size for {@link Set} instances.
29   *
30   * @author Christopher Swenson
31   */
32  public class SetIterationBenchmark {
33    @Param({ "3", "6", "11", "23", "45", "91", "181", "362", "724", "1448",
34        "2896", "5793", "11585", "23170", "46341", "92682", "185364", "370728",
35        "741455", "1482910", "2965821", "5931642"})
36    private int size;
37  
38    // "" means no fixed seed
39    @Param("1234")
40    private SpecialRandom random;
41  
42    @Param({"Immutable", "Hash"})
43    private SetImpl impl;
44  
45    // the following must be set during setUp
46    private Set<Element> setToTest;
47  
48    @BeforeExperiment void setUp() {
49      CollectionBenchmarkSampleData sampleData =
50          new CollectionBenchmarkSampleData(true, random, 0.8, size);
51      setToTest = impl.create(sampleData.getValuesInSet());
52    }
53  
54    @Benchmark int iteration(int reps) {
55      int x = 0;
56      
57      for (int i = 0; i < reps; i++) {
58        for (Element y : setToTest) {
59          x ^= System.identityHashCode(y);
60        }
61      }
62      return x;
63    }
64  }