1 /* 2 * Copyright (C) 2011 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.primitives; 18 19 import com.google.caliper.BeforeExperiment; 20 import com.google.caliper.Benchmark; 21 22 import java.util.Random; 23 24 /** 25 * Benchmarks for certain methods of {@code UnsignedLongs}. 26 * 27 * @author Eamonn McManus 28 */ 29 public class UnsignedLongsBenchmark { 30 private static final int ARRAY_SIZE = 0x10000; 31 private static final int ARRAY_MASK = 0x0ffff; 32 private static final Random RANDOM_SOURCE = new Random(314159265358979L); 33 private static final long[] longs = new long[ARRAY_SIZE]; 34 private static final long[] divisors = new long[ARRAY_SIZE]; 35 private static final String[] decimalStrings = new String[ARRAY_SIZE]; 36 private static final String[] binaryStrings = new String[ARRAY_SIZE]; 37 private static final String[] hexStrings = new String[ARRAY_SIZE]; 38 private static final String[] prefixedHexStrings = new String[ARRAY_SIZE]; 39 40 @BeforeExperiment 41 void setUp() { 42 for (int i = 0; i < ARRAY_SIZE; i++) { 43 longs[i] = random(); 44 divisors[i] = randomDivisor(longs[i]); 45 decimalStrings[i] = UnsignedLongs.toString(longs[i]); 46 binaryStrings[i] = UnsignedLongs.toString(longs[i], 2); 47 hexStrings[i] = UnsignedLongs.toString(longs[i], 16); 48 prefixedHexStrings[i] = "0x" + hexStrings[i]; 49 } 50 } 51 52 @Benchmark long divide(int reps) { 53 long tmp = 0; 54 for (int i = 0; i < reps; i++) { 55 int j = i & ARRAY_MASK; 56 tmp += UnsignedLongs.divide(longs[j], divisors[j]); 57 } 58 return tmp; 59 } 60 61 @Benchmark long remainder(int reps) { 62 long tmp = 0; 63 for (int i = 0; i < reps; i++) { 64 int j = i & ARRAY_MASK; 65 tmp += UnsignedLongs.remainder(longs[j], divisors[j]); 66 } 67 return tmp; 68 } 69 70 @Benchmark long parseUnsignedLong(int reps) { 71 long tmp = 0; 72 // Given that we make three calls per pass, we scale reps down in order 73 // to do a comparable amount of work to other measurements. 74 int scaledReps = reps / 3 + 1; 75 for (int i = 0; i < scaledReps; i++) { 76 int j = i & ARRAY_MASK; 77 tmp += UnsignedLongs.parseUnsignedLong(decimalStrings[j]); 78 tmp += UnsignedLongs.parseUnsignedLong(hexStrings[j], 16); 79 tmp += UnsignedLongs.parseUnsignedLong(binaryStrings[j], 2); 80 } 81 return tmp; 82 } 83 84 @Benchmark long parseDecode10(int reps) { 85 long tmp = 0; 86 for (int i = 0; i < reps; i++) { 87 int j = i & ARRAY_MASK; 88 tmp += UnsignedLongs.decode(decimalStrings[j]); 89 } 90 return tmp; 91 } 92 93 @Benchmark long parseDecode16(int reps) { 94 long tmp = 0; 95 for (int i = 0; i < reps; i++) { 96 int j = i & ARRAY_MASK; 97 tmp += UnsignedLongs.decode(prefixedHexStrings[j]); 98 } 99 return tmp; 100 } 101 102 @Benchmark int toString(int reps) { 103 int tmp = 0; 104 // Given that we make three calls per pass, we scale reps down in order 105 // to do a comparable amount of work to other measurements. 106 int scaledReps = reps / 3 + 1; 107 for (int i = 0; i < scaledReps; i++) { 108 int j = i & ARRAY_MASK; 109 long x = longs[j]; 110 tmp += UnsignedLongs.toString(x).length(); 111 tmp += UnsignedLongs.toString(x, 16).length(); 112 tmp += UnsignedLongs.toString(x, 2).length(); 113 } 114 return tmp; 115 } 116 117 private static long random() { 118 return RANDOM_SOURCE.nextLong(); 119 } 120 121 // A random value that cannot be 0 and that is unsigned-less-than or equal 122 // to the given dividend, so that we don't have half of our divisions being 123 // trivial because the divisor is bigger than the dividend. 124 // Using remainder here does not give us a uniform distribution but it should 125 // not have a big impact on the measurement. 126 private static long randomDivisor(long dividend) { 127 long r = RANDOM_SOURCE.nextLong(); 128 if (dividend == -1) { 129 return r; 130 } else { 131 return UnsignedLongs.remainder(r, dividend + 1); 132 } 133 } 134 } 135
