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.hash; 18 19 import com.google.caliper.BeforeExperiment; 20 import com.google.caliper.Benchmark; 21 import com.google.caliper.Param; 22 import com.google.common.hash.HashFunction; 23 24 import java.util.Random; 25 26 /** 27 * Benchmarks for comparing the various {@link HashFunction functions} that we provide. 28 * 29 * <p>Parameters for the benchmark are: 30 * <ul> 31 * <li>size: The length of the byte array to hash. 32 * <li>hashFunctionEnum: The {@link HashFunction} to use for hashing. 33 * </ul> 34 * 35 * @author Kurt Alfred Kluever 36 */ 37 public class HashFunctionBenchmark { 38 39 // Use a statically configured random instance for all of the benchmarks 40 private static final Random random = new Random(42); 41 42 @Param({"10", "1000", "100000", "1000000"}) 43 private int size; 44 45 @Param HashFunctionEnum hashFunctionEnum; 46 47 private byte[] testBytes; 48 49 @BeforeExperiment void setUp() { 50 testBytes = new byte[size]; 51 random.nextBytes(testBytes); 52 } 53 54 @Benchmark int hashFunction(int reps) { 55 HashFunction hashFunction = hashFunctionEnum.getHashFunction(); 56 int result = 37; 57 for (int i = 0; i < reps; i++) { 58 result ^= hashFunction.hashBytes(testBytes).asBytes()[0]; 59 } 60 return result; 61 } 62 } 63
