[927] | 1 | // Copyright 2012 Georg-August-Universität Göttingen, Germany |
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| 2 | // |
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| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
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| 4 | // you may not use this file except in compliance with the License. |
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| 5 | // You may obtain a copy of the License at |
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| 6 | // |
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| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
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| 8 | // |
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| 9 | // Unless required by applicable law or agreed to in writing, software |
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| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
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| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 12 | // See the License for the specific language governing permissions and |
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| 13 | // limitations under the License. |
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| 14 | |
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[922] | 15 | package de.ugoe.cs.autoquest.testgeneration; |
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[523] | 16 | |
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| 17 | import java.util.ArrayList; |
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| 18 | import java.util.Collection; |
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| 19 | import java.util.LinkedHashSet; |
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| 20 | import java.util.LinkedList; |
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| 21 | import java.util.List; |
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| 22 | import java.util.Random; |
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[639] | 23 | import java.util.logging.Level; |
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[523] | 24 | |
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[922] | 25 | import de.ugoe.cs.autoquest.eventcore.Event; |
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| 26 | import de.ugoe.cs.autoquest.usageprofiles.IStochasticProcess; |
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[523] | 27 | import de.ugoe.cs.util.console.Console; |
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| 28 | |
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| 29 | /** |
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| 30 | * <p> |
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[559] | 31 | * Generates a test suite with a hybrid approach that is a mixture of random walks and drawing from |
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| 32 | * all possible sequences. |
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[523] | 33 | * </p> |
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| 34 | * |
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| 35 | * @author Steffen Herbold |
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| 36 | * @version 1.0 |
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| 37 | */ |
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| 38 | public class HybridGenerator { |
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| 39 | |
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[559] | 40 | /** |
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| 41 | * <p> |
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| 42 | * Number of sequences in the test suite. |
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| 43 | * </p> |
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| 44 | */ |
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| 45 | private final int numSequences; |
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[523] | 46 | |
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[559] | 47 | /** |
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| 48 | * <p> |
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| 49 | * Length of a test sequence. |
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| 50 | * </p> |
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| 51 | */ |
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| 52 | private final int length; |
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[523] | 53 | |
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[559] | 54 | /** |
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| 55 | * <p> |
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| 56 | * Maximal length where it is possible to generate all sequences and draw from them. |
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| 57 | * </p> |
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| 58 | */ |
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| 59 | private final int maxLengthAll; |
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[523] | 60 | |
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[559] | 61 | /** |
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| 62 | * <p> |
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| 63 | * In case this member is true, only test cases that end in the global end event |
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| 64 | * {@link Event#ENDEVENT} are generated. If it is false, the end event can be any event. |
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| 65 | * </p> |
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| 66 | */ |
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| 67 | private final boolean validEnd; |
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[523] | 68 | |
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[559] | 69 | /** |
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| 70 | * <p> |
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| 71 | * Constructor. Creates a new HybridGenerator and ensures the validity of the parameters: |
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[2218] | 72 | * </p> |
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[559] | 73 | * <ul> |
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| 74 | * <li>numSequences must at least be 1 |
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| 75 | * <li>length must be at least 1 |
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| 76 | * </ul> |
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[2218] | 77 | * <p> |
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[766] | 78 | * If one of these conditions is violated an {@link IllegalArgumentException} is thrown. |
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[559] | 79 | * </p> |
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| 80 | * |
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| 81 | * @param numSequences |
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| 82 | * number of sequences desired for the test suite |
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| 83 | * @param length |
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| 84 | * length of a test sequence |
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| 85 | * @param maxLengthAll |
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| 86 | * maximal length where it is possible to generate all sequences and draw from them |
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| 87 | * @param validEnd |
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| 88 | * defines if test cases have to end with the global end event {@link Event#ENDEVENT} |
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| 89 | * (see {@link #validEnd}) |
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| 90 | */ |
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| 91 | public HybridGenerator(int numSequences, int length, int maxLengthAll, boolean validEnd) { |
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| 92 | // check validity of the parameters |
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| 93 | if (numSequences < 1) { |
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[766] | 94 | throw new IllegalArgumentException("number of sequences must be at least 1 but is " + |
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[559] | 95 | numSequences); |
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| 96 | } |
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| 97 | if (length < 1) { |
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[766] | 98 | throw new IllegalArgumentException("length of test cases must be at least 1 but is " + |
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[559] | 99 | length); |
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| 100 | } |
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| 101 | this.numSequences = numSequences; |
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| 102 | this.length = length; |
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| 103 | this.maxLengthAll = maxLengthAll; |
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| 104 | this.validEnd = validEnd; |
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| 105 | } |
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[523] | 106 | |
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[559] | 107 | /** |
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| 108 | * <p> |
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| 109 | * Generates a test suite with a hybrid approach that is a mixture of random walks and drawing |
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| 110 | * from all possible sequences |
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| 111 | * </p> |
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| 112 | * |
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| 113 | * @param model |
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| 114 | * model used to determine the probability of each possible sequence |
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| 115 | * @return the test suite |
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| 116 | */ |
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| 117 | public Collection<List<Event>> generateTestSuite(IStochasticProcess model) { |
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| 118 | if (model == null) { |
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[766] | 119 | throw new IllegalArgumentException("model must not be null!"); |
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[559] | 120 | } |
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[523] | 121 | |
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[559] | 122 | Collection<List<Event>> sequences = new LinkedHashSet<List<Event>>(); |
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[523] | 123 | |
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[559] | 124 | List<List<Event>> seqsTmp = |
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| 125 | new ArrayList<List<Event>>(model.generateSequences(maxLengthAll + 1, true)); |
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[523] | 126 | |
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[639] | 127 | Console.traceln(Level.INFO, "" + seqsTmp.size() + " of length " + maxLengthAll + " possible"); |
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[559] | 128 | List<Double> probabilities = new ArrayList<Double>(seqsTmp.size()); |
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| 129 | double probSum = 0.0; |
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| 130 | for (List<Event> sequence : seqsTmp) { |
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| 131 | double prob = model.getProbability(sequence); |
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| 132 | probabilities.add(prob); |
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| 133 | probSum += prob; |
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| 134 | } |
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[523] | 135 | |
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[559] | 136 | Random r = new Random(); |
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| 137 | int j = 0; |
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| 138 | while (sequences.size() < numSequences && j <= numSequences * 100) { |
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| 139 | j++; |
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| 140 | double randVal = r.nextDouble() * probSum; |
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| 141 | double sum = 0.0d; |
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| 142 | int index = -1; |
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| 143 | while (sum < randVal) { |
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| 144 | index++; |
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| 145 | double currentProb = probabilities.get(index); |
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| 146 | sum += currentProb; |
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| 147 | } |
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| 148 | List<Event> seqTmp = seqsTmp.get(index); |
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| 149 | if (!Event.ENDEVENT.equals(seqTmp.get(seqTmp.size() - 1))) { |
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| 150 | List<Event> sequence; |
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| 151 | if (validEnd) { |
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| 152 | sequence = finishSequence(seqTmp, model, length + 2, validEnd); |
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| 153 | if (sequence != null && sequence.size() != length + 2) { |
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| 154 | sequence = null; |
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| 155 | } |
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| 156 | } |
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| 157 | else { |
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| 158 | sequence = finishSequence(seqTmp, model, length + 1, validEnd); |
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| 159 | if (sequence != null && sequence.size() != length + 1) { |
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| 160 | sequence = null; |
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| 161 | } |
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| 162 | } |
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| 163 | if (sequence != null) { |
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| 164 | sequences.add(sequence); |
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| 165 | } |
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| 166 | } |
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| 167 | } |
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[523] | 168 | |
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[559] | 169 | return sequences; |
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| 170 | } |
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| 171 | |
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| 172 | /** |
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| 173 | * <p> |
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| 174 | * Finishes a sequence with a random walk. |
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| 175 | * </p> |
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| 176 | * |
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| 177 | * @param sequence |
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| 178 | * sequence to be finished |
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| 179 | * @param model |
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| 180 | * model used for the random walk |
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| 181 | * @param length |
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| 182 | * desired length of the sequence |
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| 183 | * @param validEnd |
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| 184 | * if the sequence should end in {@link Event#ENDEVENT}. |
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| 185 | * @return finished sequence of the desired length |
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| 186 | */ |
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| 187 | private List<Event> finishSequence(List<Event> sequence, |
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| 188 | IStochasticProcess model, |
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| 189 | int length, |
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| 190 | boolean validEnd) |
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| 191 | { |
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| 192 | Random r = new Random(); |
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| 193 | boolean endFound = false; |
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| 194 | List<Event> sequenceCopy = new LinkedList<Event>(sequence); |
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| 195 | final int maxIter = 30000; |
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| 196 | int iter = 0; |
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| 197 | while (!endFound && iter < maxIter) { |
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| 198 | iter++; |
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| 199 | sequenceCopy = new LinkedList<Event>(sequence); |
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| 200 | while (!endFound && sequenceCopy.size() <= length) { |
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| 201 | double randVal = r.nextDouble(); |
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| 202 | double probSum = 0.0; |
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| 203 | for (Event symbol : model.getEvents()) { |
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| 204 | probSum += model.getProbability(sequenceCopy, symbol); |
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| 205 | if (probSum >= randVal) { |
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| 206 | if (!(Event.STARTEVENT.equals(symbol) || (!validEnd && Event.ENDEVENT |
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| 207 | .equals(symbol)))) |
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| 208 | { |
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| 209 | // only add the symbol the sequence if it is not |
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| 210 | // START |
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| 211 | // or END |
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| 212 | sequenceCopy.add(symbol); |
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| 213 | } |
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| 214 | endFound = |
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| 215 | Event.ENDEVENT.equals(symbol) || |
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| 216 | (!validEnd && sequenceCopy.size() == length); |
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| 217 | break; |
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| 218 | } |
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| 219 | } |
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| 220 | } |
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| 221 | } |
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| 222 | if (iter == maxIter) { |
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| 223 | return null; |
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| 224 | } |
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| 225 | return sequenceCopy; |
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| 226 | } |
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| 227 | |
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[523] | 228 | } |
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