--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2015 Ericsson
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *******************************************************************************/
+
+package org.eclipse.tracecompass.analysis.os.linux.core.tests.latency;
+
+import java.util.Collection;
+
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.tracecompass.analysis.os.linux.core.latency.SystemCall;
+import org.eclipse.tracecompass.segmentstore.core.ISegment;
+
+/**
+ * This calculates the statistics of a segment store in an offline manner to
+ * validate online calculations.
+ *
+ * @author Matthew Khouzam
+ *
+ */
+public class OfflineStatisticsCalculator {
+ private final Collection<@NonNull SystemCall> fSs;
+
+ /**
+ * Constructor
+ *
+ * @param ss
+ * segment store, fully build
+ */
+ public OfflineStatisticsCalculator(Collection<@NonNull SystemCall> ss) {
+ fSs = ss;
+ }
+
+ /**
+ * Get the max value
+ *
+ * @return the max value
+ */
+ public long getMax() {
+ long max = Long.MIN_VALUE;
+ for (ISegment interval : fSs) {
+ max = Math.max(max, interval.getLength());
+ }
+ return max;
+ }
+
+ /**
+ * Get the min value
+ *
+ * @return the min value
+ */
+ public long getMin() {
+ long min = Long.MAX_VALUE;
+ for (ISegment interval : fSs) {
+ min = Math.min(min, interval.getLength());
+ }
+ return min;
+ }
+
+ /**
+ * Get the average value
+ *
+ * @return the average value
+ */
+ public double getAvg() {
+ double total = 0;
+ for (ISegment interval : fSs) {
+ total += (double) interval.getLength() / (double) fSs.size();
+ }
+ return total;
+ }
+
+ /**
+ * Get the standard deviation for a window.
+ *
+ * @return the standard deviation
+ */
+ public double getStdDev() {
+ if (fSs.size() < 3) {
+ return Double.NaN;
+ }
+ double mean = getAvg();
+
+ double totalVariance = 0;
+ for (ISegment interval : fSs) {
+ double result = interval.getLength() - mean;
+ totalVariance += result * result / (fSs.size() - 1);
+ }
+ return Math.sqrt(totalVariance);
+ }
+}
--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2015 Ericsson
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *******************************************************************************/
+
+package org.eclipse.tracecompass.analysis.os.linux.core.tests.latency;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Random;
+
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.tracecompass.analysis.os.linux.core.latency.SystemCall;
+import org.eclipse.tracecompass.analysis.os.linux.core.latency.SystemCall.InitialInfo;
+import org.eclipse.tracecompass.internal.analysis.os.linux.core.latency.statistics.SegmentStoreStatistics;
+import org.eclipse.tracecompass.segmentstore.core.ISegment;
+import org.junit.Test;
+
+/**
+ * Test the staticsmodule. This is done with two tests.
+ * <ol>
+ * <li>test the values vs some sample points calculated by hand (sanity test)
+ * </li>
+ * <li>2- test exhaustively vs a reference implementation.</li>
+ * </ol>
+ *
+ * @author Matthew Khouzam
+ *
+ */
+public class SegmentStoreStatisticsTest {
+
+ private static final int MEDIUM_AMOUNT_OF_SEGMENTS = 100;
+ private static final int LARGE_AMOUNT_OF_SEGMENTS = 1000000;
+
+ private static final double NO_ERROR = 0.0;
+ private static final double ERROR = 0.000001;
+
+ private static void testOnlineVsOffline(List<@NonNull SystemCall> fixture) {
+ SegmentStoreStatistics sss = getSegStoreStat(fixture);
+ OfflineStatisticsCalculator osc = new OfflineStatisticsCalculator(fixture);
+ assertEquals("Average", osc.getAvg(), sss.getAverage(), ERROR);
+ assertEquals("Standard Deviation", osc.getStdDev(), sss.getStdDev(), ERROR);
+ assertEquals("Min", osc.getMin(), sss.getMin());
+ assertEquals("Max", osc.getMax(), sss.getMax());
+ }
+
+ /**
+ * Test incrementing
+ */
+ @Test
+ public void climbTest() {
+ List<@NonNull SystemCall> fixture = new ArrayList<>();
+ for (int i = 0; i < MEDIUM_AMOUNT_OF_SEGMENTS; i++) {
+ fixture.add(createAnonSyscall(i, i * 2));
+ }
+ SegmentStoreStatistics sss = getSegStoreStat(fixture);
+ assertEquals("Average", 49.5, sss.getAverage(), ERROR);
+ assertEquals("Min", 0, sss.getMin());
+ assertEquals("Max", 99, sss.getMax());
+ assertEquals("Standard Deviation", 29.0, sss.getStdDev(), 0.02);
+ testOnlineVsOffline(fixture);
+ }
+
+ private static SegmentStoreStatistics getSegStoreStat(List<@NonNull SystemCall> fixture) {
+ SegmentStoreStatistics sss = new SegmentStoreStatistics();
+ for (ISegment seg : fixture) {
+ sss.update(seg);
+ }
+ return sss;
+ }
+
+ /**
+ * Test decrementing
+ */
+ @Test
+ public void decrementingTest() {
+ List<@NonNull SystemCall> fixture = new ArrayList<>();
+ for (int i = MEDIUM_AMOUNT_OF_SEGMENTS; i >= 0; i--) {
+ fixture.add(createAnonSyscall(i, i * 2));
+ }
+ SegmentStoreStatistics sss = getSegStoreStat(fixture);
+ assertEquals("Average", 50, sss.getAverage(), NO_ERROR);
+ assertEquals("Min", 0, sss.getMin());
+ assertEquals("Max", 100, sss.getMax());
+ assertEquals("Standard Deviation", 29.3, sss.getStdDev(), 0.01);
+ testOnlineVsOffline(fixture);
+ }
+
+ /**
+ * Test small
+ */
+ @Test
+ public void smallTest() {
+ List<@NonNull SystemCall> fixture = new ArrayList<>();
+ for (int i = 1; i >= 0; i--) {
+ fixture.add(createAnonSyscall(i, i * 2));
+ }
+ testOnlineVsOffline(fixture);
+ }
+
+ /**
+ * Test large
+ */
+ @Test
+ public void largeTest() {
+ List<@NonNull SystemCall> fixture = new ArrayList<>();
+ for (int i = 1; i <= LARGE_AMOUNT_OF_SEGMENTS; i++) {
+ fixture.add(createAnonSyscall(i, i * 2));
+ }
+ testOnlineVsOffline(fixture);
+ }
+
+ /**
+ * Test noise
+ */
+ @Test
+ public void noiseTest() {
+ Random rnd = new Random();
+ rnd.setSeed(1234);
+ List<@NonNull SystemCall> fixture = new ArrayList<>();
+ for (int i = 1; i <= LARGE_AMOUNT_OF_SEGMENTS; i++) {
+ int start = Math.abs(rnd.nextInt(100000000));
+ int end = start + Math.abs(rnd.nextInt(1000000));
+ fixture.add(createAnonSyscall(start, end));
+ }
+ testOnlineVsOffline(fixture);
+ }
+
+ /**
+ * Test gaussian noise
+ */
+ @Test
+ public void gaussianNoiseTest() {
+ Random rnd = new Random();
+ rnd.setSeed(1234);
+ List<@NonNull SystemCall> fixture = new ArrayList<>();
+ for (int i = 1; i <= LARGE_AMOUNT_OF_SEGMENTS; i++) {
+ int start = Math.abs(rnd.nextInt(100000000));
+ final int delta = Math.abs(rnd.nextInt(1000));
+ int end = start + delta * delta;
+ fixture.add(createAnonSyscall(start, end));
+ }
+ testOnlineVsOffline(fixture);
+ }
+
+ private static @NonNull SystemCall createAnonSyscall(int start, int end) {
+ return new SystemCall(new InitialInfo(start, "", Collections.EMPTY_MAP), end, 0);
+ }
+}
projects / deliverable / tracecompass.git / commitdiff
