1/*
2 * Copyright (C) 2012 Google Inc.
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
17package examples;
18
19import com.google.caliper.BeforeExperiment;
20import com.google.caliper.Benchmark;
21import com.google.caliper.Param;
22
23import java.util.ArrayList;
24import java.util.Iterator;
25import java.util.LinkedList;
26import java.util.List;
27
28/**
29 * Measures performance of list operations.
30 */
31public class ListModificationBenchmark {
32
33  private enum Element {
34    INSTANCE,
35  }
36  private enum ListImpl {
37    Array {
38      @Override List<Element> create() {
39        return new ArrayList<Element>();
40      }
41    },
42    Linked {
43      @Override List<Element> create() {
44        return new LinkedList<Element>();
45      }
46    };
47
48    abstract List<Element> create();
49  }
50
51  @Param({"10", "100", "1000", "10000"})
52  private int size;
53
54  @Param({"Array", "Linked"})
55  private ListImpl implementation;
56
57  private List<Element> list;
58
59  @BeforeExperiment void setUp() throws Exception {
60    list = implementation.create();
61    for (int i = 0; i < size; i++) {
62      list.add(Element.INSTANCE);
63    }
64  }
65
66  @Benchmark void populate(int reps) throws Exception {
67    for (int rep = 0; rep < reps; rep++) {
68      List<Element> list = implementation.create();
69      for (int i = 0; i < size; i++) {
70        list.add(Element.INSTANCE);
71      }
72    }
73  }
74
75  @Benchmark void iteration(int reps) {
76    for (int rep = 0; rep < reps; rep++) {
77      Iterator<Element> iterator = list.iterator();
78      while (iterator.hasNext()) {
79        iterator.next();
80      }
81    }
82  }
83
84  @Benchmark void headAddRemove(int reps) {
85    for (int rep = 0; rep < reps; rep++) {
86      list.add(0, Element.INSTANCE);
87      list.remove(0);
88    }
89  }
90
91  @Benchmark void middleAddRemove(int reps) {
92    int index = size / 2;
93    for (int rep = 0; rep < reps; rep++) {
94      list.add(index, Element.INSTANCE);
95      list.remove(index);
96    }
97  }
98
99  @Benchmark void tailAddRemove(int reps) {
100    int index = size - 1;
101    for (int rep = 0; rep < reps; rep++) {
102      list.add(Element.INSTANCE);
103      list.remove(index);
104    }
105  }
106}
107