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 17 package benchmarks; 18 19 import com.google.caliper.Param; 20 import com.google.caliper.Runner; 21 import com.google.caliper.SimpleBenchmark; 22 23 /** 24 * How do various ways of iterating through an array compare? 25 */ 26 public 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 } timeArrayIteration(int reps)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 } timeArrayIterationCached(int reps)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 } timeArrayIterationForEach(int reps)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