| 1 | /******************************************************************************* |
| 2 | * Copyright (c) 2015 École Polytechnique de Montréal |
| 3 | * |
| 4 | * All rights reserved. This program and the accompanying materials are made |
| 5 | * available under the terms of the Eclipse Public License v1.0 which |
| 6 | * accompanies this distribution, and is available at |
| 7 | * http://www.eclipse.org/legal/epl-v10.html |
| 8 | * |
| 9 | * Contributors: |
| 10 | * Francis Giraldeau - Initial implementation and API |
| 11 | * Geneviève Bastien - Fixes and improvements |
| 12 | *******************************************************************************/ |
| 13 | |
| 14 | package org.eclipse.tracecompass.tmf.core.tests.synchronization; |
| 15 | |
| 16 | import static org.junit.Assert.assertEquals; |
| 17 | import static org.junit.Assert.assertNotNull; |
| 18 | import static org.junit.Assert.assertTrue; |
| 19 | import static org.junit.Assert.fail; |
| 20 | |
| 21 | import java.io.File; |
| 22 | import java.io.FileInputStream; |
| 23 | import java.io.FileOutputStream; |
| 24 | import java.io.IOException; |
| 25 | import java.io.ObjectInputStream; |
| 26 | import java.io.ObjectOutputStream; |
| 27 | import java.util.Arrays; |
| 28 | |
| 29 | import org.eclipse.tracecompass.internal.tmf.core.synchronization.TmfTimestampTransformLinear; |
| 30 | import org.eclipse.tracecompass.internal.tmf.core.synchronization.TmfTimestampTransformLinearFast; |
| 31 | import org.eclipse.tracecompass.tmf.core.synchronization.ITmfTimestampTransform; |
| 32 | import org.junit.Test; |
| 33 | import org.junit.runner.RunWith; |
| 34 | import org.junit.runners.Parameterized; |
| 35 | import org.junit.runners.Parameterized.Parameters; |
| 36 | |
| 37 | /** |
| 38 | * Tests for {@link TmfTimestampTransformLinearFast} |
| 39 | * |
| 40 | * @author Geneviève Bastien |
| 41 | */ |
| 42 | @RunWith(Parameterized.class) |
| 43 | public class TsTransformFastTest { |
| 44 | |
| 45 | private static final long ts = 1361657893526374091L; |
| 46 | |
| 47 | private static interface IFastTransformFactory { |
| 48 | public TmfTimestampTransformLinearFast create(double alpha, double beta); |
| 49 | } |
| 50 | |
| 51 | private static final IFastTransformFactory fNewObject = (a, b) -> { |
| 52 | return new TmfTimestampTransformLinearFast(a, b); |
| 53 | }; |
| 54 | |
| 55 | private static final IFastTransformFactory fDeserialized = (a, b) -> { |
| 56 | TmfTimestampTransformLinearFast tt = new TmfTimestampTransformLinearFast(a, b); |
| 57 | /* Serialize the object */ |
| 58 | String filePath = null; |
| 59 | try { |
| 60 | File temp = File.createTempFile("serialSyncAlgo", ".tmp"); |
| 61 | filePath = temp.getAbsolutePath(); |
| 62 | } catch (IOException e) { |
| 63 | fail("Could not create temporary file for serialization"); |
| 64 | } |
| 65 | assertNotNull(filePath); |
| 66 | |
| 67 | try (FileOutputStream fileOut = new FileOutputStream(filePath); |
| 68 | ObjectOutputStream out = new ObjectOutputStream(fileOut);) { |
| 69 | out.writeObject(tt); |
| 70 | } catch (IOException e) { |
| 71 | fail("Error serializing the synchronization algorithm " + e.getMessage()); |
| 72 | } |
| 73 | |
| 74 | TmfTimestampTransformLinearFast deserialTt = null; |
| 75 | /* De-Serialize the object */ |
| 76 | try (FileInputStream fileIn = new FileInputStream(filePath); |
| 77 | ObjectInputStream in = new ObjectInputStream(fileIn);) { |
| 78 | deserialTt = (TmfTimestampTransformLinearFast) in.readObject(); |
| 79 | } catch (IOException | ClassNotFoundException e) { |
| 80 | fail("Error de-serializing the synchronization algorithm " + e.getMessage()); |
| 81 | } |
| 82 | return deserialTt; |
| 83 | }; |
| 84 | |
| 85 | private final IFastTransformFactory fTransformFactory; |
| 86 | |
| 87 | /** |
| 88 | * Constructor |
| 89 | * |
| 90 | * @param name |
| 91 | * The name of this parameterized test |
| 92 | * @param factory |
| 93 | * Factory to create the timestamp transform |
| 94 | */ |
| 95 | public TsTransformFastTest(String name, IFastTransformFactory factory) { |
| 96 | fTransformFactory = factory; |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * @return the test parameters |
| 101 | */ |
| 102 | @Parameters(name = "Factory={0}") |
| 103 | public static Iterable<Object[]> parameters() { |
| 104 | return Arrays.asList(new Object[][] { |
| 105 | { "Object", fNewObject }, |
| 106 | { "Deserialized", fDeserialized } |
| 107 | }); |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Test whether the fast linear transform always yields the same value for |
| 112 | * the same timestamp |
| 113 | */ |
| 114 | @Test |
| 115 | public void testFLTRepeatability() { |
| 116 | TmfTimestampTransformLinearFast fast = fTransformFactory.create(Math.PI, 0); |
| 117 | // Access fDeltaMax to compute the cache range boundaries |
| 118 | long deltaMax = fast.getDeltaMax(); |
| 119 | // Initialize the transform |
| 120 | long timestamp = ts - (ts % deltaMax); |
| 121 | fast.transform(timestamp); |
| 122 | long tsMiss = timestamp + deltaMax; |
| 123 | long tsNoMiss = timestamp + deltaMax - 1; |
| 124 | |
| 125 | // Get the transformed value to a timestamp without cache miss |
| 126 | long tsTNoMiss = fast.transform(tsNoMiss); |
| 127 | assertEquals(1, fast.getCacheMisses()); |
| 128 | |
| 129 | // Cause a cache miss |
| 130 | fast.transform(tsMiss); |
| 131 | assertEquals(2, fast.getCacheMisses()); |
| 132 | |
| 133 | /* |
| 134 | * Get the transformed value of the same previous timestamp after the |
| 135 | * miss |
| 136 | */ |
| 137 | long tsTAfterMiss = fast.transform(tsNoMiss); |
| 138 | assertEquals(tsTNoMiss, tsTAfterMiss); |
| 139 | } |
| 140 | |
| 141 | /** |
| 142 | * Test that 2 equal fast transform always give the same results for the |
| 143 | * same values |
| 144 | */ |
| 145 | @Test |
| 146 | public void testFLTEquivalence() { |
| 147 | TmfTimestampTransformLinearFast fast = fTransformFactory.create(Math.PI, 0); |
| 148 | TmfTimestampTransformLinearFast fast2 = fTransformFactory.create(Math.PI, 0); |
| 149 | |
| 150 | long deltaMax = fast.getDeltaMax(); |
| 151 | |
| 152 | long start = (ts - (ts % deltaMax) - 10); |
| 153 | checkTime(fast, fast2, 20, start, 1); |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * Test the precision of the fast timestamp transform compared to the |
| 158 | * original transform. |
| 159 | */ |
| 160 | @Test |
| 161 | public void testFastTransformPrecision() { |
| 162 | TmfTimestampTransformLinear precise = new TmfTimestampTransformLinear(Math.PI, 0); |
| 163 | TmfTimestampTransformLinearFast fast = fTransformFactory.create(Math.PI, 0); |
| 164 | int samples = 100; |
| 165 | long start = (long) Math.pow(10, 18); |
| 166 | long end = Long.MAX_VALUE; |
| 167 | int step = (int) ((end - start) / (samples * Math.PI)); |
| 168 | checkTime(precise, fast, samples, start, step); |
| 169 | assertEquals(samples, fast.getCacheMisses()); |
| 170 | |
| 171 | // check that rescale is done only when required |
| 172 | // assumes tsBitWidth == 30 |
| 173 | // test forward and backward timestamps |
| 174 | samples = 1000; |
| 175 | int[] directions = new int[] { 1, -1 }; |
| 176 | for (Integer direction : directions) { |
| 177 | for (int i = 0; i <= 30; i++) { |
| 178 | fast.resetScaleStats(); |
| 179 | step = (1 << i) * direction; |
| 180 | checkTime(precise, fast, samples, start, step); |
| 181 | assertTrue(String.format("samples: %d scale misses: %d", |
| 182 | samples, fast.getCacheMisses()), samples >= fast.getCacheMisses()); |
| 183 | } |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | /** |
| 188 | * Test that fast transform produces the same result for small and large |
| 189 | * slopes. |
| 190 | */ |
| 191 | @Test |
| 192 | public void testFastTransformSlope() { |
| 193 | int[] dir = new int[] { 1, -1 }; |
| 194 | long start = (1 << 30); |
| 195 | for (int ex = -9; ex <= 9; ex++) { |
| 196 | for (int d = 0; d < dir.length; d++) { |
| 197 | double slope = Math.pow(10.0, ex); |
| 198 | TmfTimestampTransformLinear precise = new TmfTimestampTransformLinear(slope, 0); |
| 199 | TmfTimestampTransformLinearFast fast = fTransformFactory.create(slope, 0); |
| 200 | checkTime(precise, fast, 1000, start, dir[d]); |
| 201 | } |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | /** |
| 206 | * Test that fast transform produces the same result with a slope and |
| 207 | * offset, for small and large values |
| 208 | */ |
| 209 | @Test |
| 210 | public void testFastTransformSlopeAndOffset() { |
| 211 | double offset = 54321.0; |
| 212 | double slope = Math.pow(10.0, 4); |
| 213 | for (int ex = 0; ex <= Long.SIZE - 1; ex++) { |
| 214 | long start = 1 << ex; |
| 215 | TmfTimestampTransformLinear precise = new TmfTimestampTransformLinear(slope, offset); |
| 216 | TmfTimestampTransformLinearFast fast = fTransformFactory.create(slope, offset); |
| 217 | checkTime(precise, fast, 5, start, 1); |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | /** |
| 222 | * Check that the proper exception are raised for illegal slopes |
| 223 | */ |
| 224 | @Test |
| 225 | public void testFastTransformArguments() { |
| 226 | double[] slopes = new double[] { -1.0, ((double) Integer.MAX_VALUE) + 1, 1e-10 }; |
| 227 | for (double slope : slopes) { |
| 228 | Exception exception = null; |
| 229 | try { |
| 230 | fTransformFactory.create(slope, 0.0); |
| 231 | } catch (IllegalArgumentException e) { |
| 232 | exception = e; |
| 233 | } |
| 234 | assertNotNull(exception); |
| 235 | } |
| 236 | } |
| 237 | |
| 238 | private static void checkTime(ITmfTimestampTransform precise, ITmfTimestampTransform fast, |
| 239 | int samples, long start, long step) { |
| 240 | long prev = 0; |
| 241 | for (int i = 0; i < samples; i++) { |
| 242 | long time = start + i * step; |
| 243 | long exp = precise.transform(time); |
| 244 | long act = fast.transform(time); |
| 245 | long err = act - exp; |
| 246 | // allow only two ns of error |
| 247 | assertTrue("start: " + start + " [" + err + "]", Math.abs(err) < 3); |
| 248 | if (i > 0) { |
| 249 | if (step > 0) { |
| 250 | assertTrue("monotonic error" + act + " " + prev, act >= prev); |
| 251 | } else if (step < 0) { |
| 252 | assertTrue("monotonic ", act <= prev); |
| 253 | } |
| 254 | } |
| 255 | prev = act; |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | } |