1/*
2 * Copyright (C) 2010 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 benchmarks;
18
19import com.google.caliper.Param;
20import com.google.caliper.Runner;
21import com.google.caliper.SimpleBenchmark;
22
23/**
24 * How do various ways of iterating through an array compare?
25 */
26public class ArrayIterationBenchmark extends SimpleBenchmark {
27    Foo[] mArray = new Foo[27];
28    {
29        for (int i = 0; i < mArray.length; ++i) mArray[i] = new Foo();
30    }
31    public void timeArrayIteration(int reps) {
32        for (int rep = 0; rep < reps; ++rep) {
33            int sum = 0;
34            for (int i = 0; i < mArray.length; i++) {
35                sum += mArray[i].mSplat;
36            }
37        }
38    }
39    public void timeArrayIterationCached(int reps) {
40        for (int rep = 0; rep < reps; ++rep) {
41            int sum = 0;
42            Foo[] localArray = mArray;
43            int len = localArray.length;
44
45            for (int i = 0; i < len; i++) {
46                sum += localArray[i].mSplat;
47            }
48        }
49    }
50    public void timeArrayIterationForEach(int reps) {
51        for (int rep = 0; rep < reps; ++rep) {
52            int sum = 0;
53            for (Foo a: mArray) {
54                sum += a.mSplat;
55            }
56        }
57    }
58}
59