qmlprofiler: Fix data sorting

When analyzing a range with multiple child ranges, qmlprofiler would
create a rather random association between the start and end events.

Pick-to: 6.2
Change-Id: I564d2c74656dda1cb0963c75cd7b947a7f86d05e
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit cc761e9c5a)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 378de2f412)
(cherry picked from commit 06fc186371)

tools/qmlprofiler/qmlprofilerdata.cpp

@@ -3,14 +3,12 @@
 
 #include "qmlprofilerdata.h"
 
-#include <QStringList>
-#include <QUrl>
-#include <QHash>
-#include <QFile>
-#include <QXmlStreamReader>
-#include <QRegularExpression>
-#include <QQueue>
-#include <QStack>
+#include <QtCore/qfile.h>
+#include <QtCore/qqueue.h>
+#include <QtCore/qregularexpression.h>
+#include <QtCore/qurl.h>
+#include <QtCore/qxmlstream.h>
+#include <QtCore/qxpfunctional.h>
 
 #include <limits>
 
@@ -375,6 +373,132 @@ private:
     QXmlStreamWriter stream;
 };
 
+struct DataIterator
+{
+    DataIterator(
+            const QmlProfilerDataPrivate *d,
+            qxp::function_ref<void(const QQmlProfilerEvent &, qint64)> &&sendEvent)
+        : d(d)
+        , sendEvent(std::move(sendEvent))
+    {}
+
+    void run();
+
+private:
+    void handleRangeEvent(const QQmlProfilerEvent &event, const QQmlProfilerEventType &type);
+    void sendPending();
+    void endLevel0();
+
+    const QmlProfilerDataPrivate *d = nullptr;
+    const qxp::function_ref<void(const QQmlProfilerEvent &, qint64)> sendEvent;
+
+    QQueue<QQmlProfilerEvent> pointEvents;
+    QList<QQmlProfilerEvent> rangeStarts[MaximumRangeType];
+    QList<qint64> rangeEnds[MaximumRangeType];
+
+    int level = 0;
+};
+
+void DataIterator::handleRangeEvent(
+        const QQmlProfilerEvent &event, const QQmlProfilerEventType &type)
+{
+    QList<QQmlProfilerEvent> &starts = rangeStarts[type.rangeType()];
+    switch (event.rangeStage()) {
+    case RangeStart: {
+        ++level;
+        starts.append(event);
+        break;
+    }
+    case RangeEnd: {
+        const qint64 invalidTimestamp = -1;
+        QList<qint64> &ends = rangeEnds[type.rangeType()];
+
+               // -1 because all valid timestamps are >= 0.
+        ends.resize(starts.size(), invalidTimestamp);
+
+        qsizetype i = starts.size();
+        while (ends[--i] != invalidTimestamp) {}
+
+        Q_ASSERT(i >= 0);
+        Q_ASSERT(starts[i].timestamp() <= event.timestamp());
+
+        ends[i] = event.timestamp();
+        if (--level == 0)
+            endLevel0();
+        break;
+    }
+    default:
+        break;
+    }
+}
+
+void DataIterator::sendPending()
+{
+    // Send all pending events in the order of their start times.
+
+    qsizetype index[MaximumRangeType] = { 0, 0, 0, 0, 0, 0 };
+    while (true) {
+
+        // Find the range type with the minimum start time.
+        qsizetype minimum = MaximumRangeType;
+        qint64 minimumTime = std::numeric_limits<qint64>::max();
+        for (qsizetype i = 0; i < MaximumRangeType; ++i) {
+            const QList<QQmlProfilerEvent> &starts = rangeStarts[i];
+            if (starts.size() == index[i])
+                continue;
+            const qint64 timestamp = starts[index[i]].timestamp();
+            if (timestamp < minimumTime) {
+                minimumTime = timestamp;
+                minimum = i;
+            }
+        }
+        if (minimum == MaximumRangeType)
+            break;
+
+        // Send all point events that happened before the range we've found.
+        while (!pointEvents.isEmpty() && pointEvents.front().timestamp() < minimumTime)
+            sendEvent(pointEvents.dequeue(), 0);
+
+        // Send the range itself
+        sendEvent(rangeStarts[minimum][index[minimum]],
+                  rangeEnds[minimum][index[minimum]] - minimumTime);
+
+        // Bump the index so that we don't send the same range again
+        ++index[minimum];
+    }
+}
+
+void DataIterator::endLevel0()
+{
+    sendPending();
+    for (qsizetype i = 0; i < MaximumRangeType; ++i) {
+        rangeStarts[i].clear();
+        rangeEnds[i].clear();
+    }
+}
+
+void DataIterator::run()
+{
+    for (const QQmlProfilerEvent &event : std::as_const(d->events)) {
+        const QQmlProfilerEventType &type = d->eventTypes.at(event.typeIndex());
+        if (type.rangeType() != MaximumRangeType)
+            handleRangeEvent(event, type);
+        else if (level == 0)
+            sendEvent(event, 0);
+        else
+            pointEvents.enqueue(event);
+    }
+
+    for (qsizetype i = 0; i < MaximumRangeType; ++i) {
+        while (rangeEnds[i].size() < rangeStarts[i].size()) {
+            rangeEnds[i].append(d->traceEndTime);
+            --level;
+        }
+    }
+
+    sendPending();
+}
+
 bool QmlProfilerData::save(const QString &filename)
 {
     if (isEmpty()) {
@@ -442,6 +566,7 @@ bool QmlProfilerData::save(const QString &filename)
     stream.writeStartElement("profilerDataModel");
 
     auto sendEvent = [&](const QQmlProfilerEvent &event, qint64 duration = 0) {
+        Q_ASSERT(duration >= 0);
         const QQmlProfilerEventType &type = d->eventTypes.at(event.typeIndex());
         stream.writeStartElement("range");
         stream.writeAttribute("startTime", event.timestamp());
@@ -481,74 +606,7 @@ bool QmlProfilerData::save(const QString &filename)
         stream.writeEndElement();
     };
 
-    QQueue<QQmlProfilerEvent> pointEvents;
-    QQueue<QQmlProfilerEvent> rangeStarts[MaximumRangeType];
-    QStack<qint64> rangeEnds[MaximumRangeType];
-    int level = 0;
-
-    auto sendPending = [&]() {
-        forever {
-            int minimum = MaximumRangeType;
-            qint64 minimumTime = std::numeric_limits<qint64>::max();
-            for (int i = 0; i < MaximumRangeType; ++i) {
-                const QQueue<QQmlProfilerEvent> &starts = rangeStarts[i];
-                if (starts.isEmpty())
-                    continue;
-                if (starts.head().timestamp() < minimumTime) {
-                    minimumTime = starts.head().timestamp();
-                    minimum = i;
-                }
-            }
-            if (minimum == MaximumRangeType)
-                break;
-
-            while (!pointEvents.isEmpty() && pointEvents.front().timestamp() < minimumTime)
-                sendEvent(pointEvents.dequeue());
-
-            sendEvent(rangeStarts[minimum].dequeue(),
-                      rangeEnds[minimum].pop() - minimumTime);
-        }
-    };
-
-    for (const QQmlProfilerEvent &event : std::as_const(d->events)) {
-        const QQmlProfilerEventType &type = d->eventTypes.at(event.typeIndex());
-
-        if (type.rangeType() != MaximumRangeType) {
-            QQueue<QQmlProfilerEvent> &starts = rangeStarts[type.rangeType()];
-            switch (event.rangeStage()) {
-            case RangeStart: {
-                ++level;
-                starts.enqueue(event);
-                break;
-            }
-            case RangeEnd: {
-                QStack<qint64> &ends = rangeEnds[type.rangeType()];
-                if (starts.size() > ends.size()) {
-                    ends.push(event.timestamp());
-                    if (--level == 0)
-                        sendPending();
-                }
-                break;
-            }
-            default:
-                break;
-            }
-        } else {
-            if (level == 0)
-                sendEvent(event);
-            else
-                pointEvents.enqueue(event);
-        }
-    }
-
-    for (int i = 0; i < MaximumRangeType; ++i) {
-        while (rangeEnds[i].size() < rangeStarts[i].size()) {
-            rangeEnds[i].push(d->traceEndTime);
-            --level;
-        }
-    }
-
-    sendPending();
+    DataIterator(d, std::move(sendEvent)).run();
 
     stream.writeEndElement(); // profilerDataModel