| /* |
| * Copyright (C) 2010 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 static com.google.common.base.Preconditions.checkNotNull; |
| |
| import com.google.common.primitives.Ints; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * Package up sample data for common collections benchmarking. |
| * |
| * @author Nicholaus Shupe |
| */ |
| class CollectionBenchmarkSampleData { |
| private final boolean isUserTypeFast; |
| private final SpecialRandom random; |
| private final double hitRate; |
| private final int size; |
| |
| private final Set<Element> valuesInSet; |
| private final Element[] queries; |
| |
| CollectionBenchmarkSampleData(int size) { |
| this(true, new SpecialRandom(), 1.0, size); |
| } |
| |
| CollectionBenchmarkSampleData( |
| boolean isUserTypeFast, SpecialRandom random, double hitRate, int size) { |
| this.isUserTypeFast = isUserTypeFast; |
| this.random = checkNotNull(random); |
| this.hitRate = hitRate; |
| this.size = size; |
| |
| this.valuesInSet = createData(); |
| this.queries = createQueries(valuesInSet, 1024); |
| } |
| |
| Set<Element> getValuesInSet() { |
| return valuesInSet; |
| } |
| |
| Element[] getQueries() { |
| return queries; |
| } |
| |
| private Element[] createQueries(Set<Element> elementsInSet, int numQueries) { |
| List<Element> queryList = Lists.newArrayListWithCapacity(numQueries); |
| |
| int numGoodQueries = (int) (numQueries * hitRate + 0.5); |
| |
| // add good queries |
| int size = elementsInSet.size(); |
| if (size > 0) { |
| int minCopiesOfEachGoodQuery = numGoodQueries / size; |
| int extras = numGoodQueries % size; |
| |
| for (int i = 0; i < minCopiesOfEachGoodQuery; i++) { |
| queryList.addAll(elementsInSet); |
| } |
| List<Element> tmp = Lists.newArrayList(elementsInSet); |
| Collections.shuffle(tmp, random); |
| queryList.addAll(tmp.subList(0, extras)); |
| } |
| |
| // now add bad queries |
| while (queryList.size() < numQueries) { |
| Element candidate = newElement(); |
| if (!elementsInSet.contains(candidate)) { |
| queryList.add(candidate); |
| } |
| } |
| Collections.shuffle(queryList, random); |
| return queryList.toArray(new Element[0]); |
| } |
| |
| private Set<Element> createData() { |
| Set<Element> set = Sets.newHashSetWithExpectedSize(size); |
| while (set.size() < size) { |
| set.add(newElement()); |
| } |
| return set; |
| } |
| |
| private Element newElement() { |
| int value = random.nextInt(); |
| return isUserTypeFast ? new Element(value) : new SlowElement(value); |
| } |
| |
| static class Element implements Comparable<Element> { |
| final int hash; |
| |
| Element(int hash) { |
| this.hash = hash; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| return this == obj || (obj instanceof Element && ((Element) obj).hash == hash); |
| } |
| |
| @Override |
| public int hashCode() { |
| return hash; |
| } |
| |
| @Override |
| public int compareTo(Element that) { |
| return Ints.compare(hash, that.hash); |
| } |
| |
| @Override |
| public String toString() { |
| return String.valueOf(hash); |
| } |
| } |
| |
| static class SlowElement extends Element { |
| SlowElement(int hash) { |
| super(hash); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| return slowItDown() != 1 && super.equals(obj); |
| } |
| |
| @Override |
| public int hashCode() { |
| return slowItDown() + hash; |
| } |
| |
| @Override |
| public int compareTo(Element e) { |
| int x = slowItDown(); |
| return x + super.compareTo(e) - x; // silly attempt to prevent opt |
| } |
| |
| static int slowItDown() { |
| int result = 0; |
| for (int i = 1; i <= 1000; i++) { |
| result += i; |
| } |
| return result; |
| } |
| } |
| } |