/* * Copyright (C) 2015 The Guava Authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.google.common.collect; import com.google.caliper.BeforeExperiment; import com.google.caliper.Benchmark; import com.google.caliper.Param; import com.google.caliper.api.SkipThisScenarioException; import java.util.Random; /** A benchmark that tries invoking {@code Set.contains} on many different sets. */ public class MultipleSetContainsBenchmark { @Param({"0.0", "0.1", "0.7", "1.0"}) double emptySetProportion; @Param({"0.0", "0.1", "0.7", "1.0"}) double singletonSetProportion; @Param({"0.2", "0.8"}) double hitRate; static final Object PRESENT = new Object(); static final Object ABSENT = new Object(); @SuppressWarnings("unchecked") private final ImmutableSet[] sets = new ImmutableSet[0x1000]; private final Object[] queries = new Object[0x1000]; @BeforeExperiment void setUp() { if (emptySetProportion + singletonSetProportion > 1.01) { throw new SkipThisScenarioException(); } Random rng = new Random(); for (int i = 0; i < 0x1000; i++) { double setSize = rng.nextDouble(); if (setSize < emptySetProportion) { sets[i] = ImmutableSet.of(); } else if (setSize < emptySetProportion + singletonSetProportion) { sets[i] = ImmutableSet.of(PRESENT); } else { sets[i] = ImmutableSet.of(PRESENT, new Object()); } if (rng.nextDouble() < hitRate) { queries[i] = PRESENT; } else { queries[i] = ABSENT; } } } @Benchmark public boolean contains(int reps) { ImmutableSet[] sets = this.sets; Object[] queries = this.queries; boolean result = false; for (int i = 0; i < reps; i++) { int j = i & 0xFFF; result ^= sets[j].contains(queries[j]); } return result; } }