84 lines
2.3 KiB
Java
84 lines
2.3 KiB
Java
/*
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* Copyright (C) 2012 The Guava Authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.google.common.hash;
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import com.google.caliper.BeforeExperiment;
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import com.google.caliper.Benchmark;
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import com.google.caliper.Param;
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import java.util.Random;
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/**
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* Benchmarks for comparing the various {@link HashFunction functions} that we provide.
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*
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* <p>Parameters for the benchmark are:
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*
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* <ul>
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* <li>size: The length of the byte array to hash.
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* <li>hashFunctionEnum: The {@link HashFunction} to use for hashing.
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* </ul>
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*
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* @author Kurt Alfred Kluever
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*/
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public class HashFunctionBenchmark {
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// Use a statically configured random instance for all of the benchmarks
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private static final Random random = new Random(42);
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@Param({"10", "1000", "100000", "1000000"})
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private int size;
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@Param HashFunctionEnum hashFunctionEnum;
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private byte[] testBytes;
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@BeforeExperiment
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void setUp() {
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testBytes = new byte[size];
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random.nextBytes(testBytes);
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}
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@Benchmark
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int hasher(int reps) {
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HashFunction hashFunction = hashFunctionEnum.getHashFunction();
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int result = 37;
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for (int i = 0; i < reps; i++) {
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result ^= hashFunction.newHasher().putBytes(testBytes).hash().asBytes()[0];
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}
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return result;
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}
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@Benchmark
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int hashFunction(int reps) {
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HashFunction hashFunction = hashFunctionEnum.getHashFunction();
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int result = 37;
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for (int i = 0; i < reps; i++) {
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result ^= hashFunction.hashBytes(testBytes).asBytes()[0];
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}
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return result;
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}
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@Benchmark
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int hashFunctionWithOffset(int reps) {
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HashFunction hashFunction = hashFunctionEnum.getHashFunction();
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int result = 37;
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for (int i = 0; i < reps; i++) {
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result ^= hashFunction.hashBytes(testBytes, 1, testBytes.length - 1).asBytes()[0];
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}
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return result;
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}
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}
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