Better unread statistics

.github/workflows/ci.yml

@@ -158,6 +158,8 @@ jobs:
       env:
         TEST_USER: ${{ secrets.TEST_USER }}
         TEST_PWD: ${{ secrets.TEST_PWD }}
+        QT_LOGGING_RULES: 'quotient.main.debug=true;quotient.jobs.debug=true'
+        QT_MESSAGE_PATTERN: '%{time h:mm:ss.zzz}|%{category}|%{if-debug}D%{endif}%{if-info}I%{endif}%{if-warning}W%{endif}%{if-critical}C%{endif}%{if-fatal}F%{endif}|%{message}'
       run: |
         [[ -z "$TEST_USER" ]] || $VALGRIND build/quotest/quotest "$TEST_USER" "$TEST_PWD" quotest-gha '#quotest:matrix.org' "$QUOTEST_ORIGIN"
       timeout-minutes: 5 # quotest is supposed to finish within 3 minutes, actually

CMakeLists.txt

@@ -135,6 +135,7 @@ list(APPEND lib_SRCS
     lib/avatar.cpp
     lib/uri.cpp
     lib/uriresolver.cpp
+    lib/eventstats.cpp
     lib/syncdata.cpp
     lib/settings.cpp
     lib/networksettings.cpp

lib/eventstats.cpp

@@ -0,0 +1,98 @@
+// SPDX-FileCopyrightText: 2021 Quotient contributors
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "eventstats.h"
+
+using namespace Quotient;
+
+EventStats EventStats::fromRange(const Room* room, const Room::rev_iter_t& from,
+                                 const Room::rev_iter_t& to,
+                                 const EventStats& init)
+{
+    Q_ASSERT(to <= room->historyEdge());
+    Q_ASSERT(from >= Room::rev_iter_t(room->syncEdge()));
+    Q_ASSERT(from <= to);
+    QElapsedTimer et;
+    et.start();
+    const auto result =
+        accumulate(from, to, init,
+                   [room](EventStats acc, const TimelineItem& ti) {
+                       acc.notableCount += room->isEventNotable(ti);
+                       acc.highlightCount += room->notificationFor(ti).type
+                                             == Notification::Highlight;
+                       return acc;
+                   });
+    if (et.nsecsElapsed() > profilerMinNsecs() / 10)
+        qCDebug(PROFILER).nospace()
+            << "Event statistics collection over index range [" << from->index()
+            << "," << (to - 1)->index() << "] took " << et;
+    return result;
+}
+
+EventStats EventStats::fromMarker(const Room* room,
+                                  const EventStats::marker_t& marker)
+{
+    const auto s = fromRange(room, marker_t(room->syncEdge()), marker,
+                             { 0, 0, marker == room->historyEdge() });
+    Q_ASSERT(s.isValidFor(room, marker));
+    return s;
+}
+
+EventStats EventStats::fromCachedCounters(Omittable<int> notableCount,
+                                          Omittable<int> highlightCount)
+{
+    const auto hCount = std::max(0, highlightCount.value_or(0));
+    if (!notableCount.has_value())
+        return { 0, hCount, true };
+    auto nCount = notableCount.value_or(0);
+    return { std::max(0, nCount), hCount, nCount != -1 };
+}
+
+bool EventStats::updateOnMarkerMove(const Room* room, const marker_t& oldMarker,
+                                    const marker_t& newMarker)
+{
+    if (newMarker == oldMarker)
+        return false;
+
+    // Double-check consistency between the old marker and the old stats
+    Q_ASSERT(isValidFor(room, oldMarker));
+    Q_ASSERT(oldMarker > newMarker);
+
+    // A bit of optimisation: only calculate the difference if the marker moved
+    // less than half the remaining timeline ahead; otherwise, recalculation
+    // over the remaining timeline will very likely be faster.
+    if (oldMarker != room->historyEdge()
+        && oldMarker - newMarker < newMarker - marker_t(room->syncEdge())) {
+        const auto removedStats = fromRange(room, newMarker, oldMarker);
+        Q_ASSERT(notableCount >= removedStats.notableCount
+                 && highlightCount >= removedStats.highlightCount);
+        notableCount -= removedStats.notableCount;
+        highlightCount -= removedStats.highlightCount;
+        return removedStats.notableCount > 0 || removedStats.highlightCount > 0;
+    }
+
+    const auto newStats = EventStats::fromMarker(room, newMarker);
+    if (!isEstimate && newStats == *this)
+        return false;
+    *this = newStats;
+    return true;
+}
+
+bool EventStats::isValidFor(const Room* room, const marker_t& marker) const
+{
+    const auto markerAtHistoryEdge = marker == room->historyEdge();
+    // Either markerAtHistoryEdge and isEstimate are in the same state, or it's
+    // a special case of no notable events and the marker at history edge
+    // (then isEstimate can assume any value).
+    return markerAtHistoryEdge == isEstimate
+           || (markerAtHistoryEdge && notableCount == 0);
+}
+
+QDebug Quotient::operator<<(QDebug dbg, const EventStats& es)
+{
+    QDebugStateSaver _(dbg);
+    dbg.nospace() << es.notableCount << '/' << es.highlightCount;
+    if (es.isEstimate)
+        dbg << " (estimated)";
+    return dbg;
+}

lib/eventstats.h

@@ -0,0 +1,114 @@
+// SPDX-FileCopyrightText: 2021 Quotient contributors
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#pragma once
+
+#include "room.h"
+
+namespace Quotient {
+
+//! \brief Counters of unread events and highlights with a precision flag
+//!
+//! This structure contains a static snapshot with values of unread counters
+//! returned by Room::partiallyReadStats and Room::unreadStats (properties
+//! or methods).
+//!
+//! \note It's just a simple grouping of counters and is not automatically
+//! updated from the room as subsequent syncs arrive.
+//! \sa Room::unreadStats, Room::partiallyReadStats, Room::isEventNotable
+struct EventStats {
+    Q_GADGET
+    Q_PROPERTY(qsizetype notableCount MEMBER notableCount CONSTANT)
+    Q_PROPERTY(qsizetype highlightCount MEMBER highlightCount CONSTANT)
+    Q_PROPERTY(bool isEstimate MEMBER isEstimate CONSTANT)
+public:
+    //! The number of "notable" events in an events range
+    //! \sa Room::isEventNotable
+    qsizetype notableCount = 0;
+    qsizetype highlightCount = 0;
+    //! \brief Whether the counter values above are exact
+    //!
+    //! This is false when the end marker (m.read receipt or m.fully_read) used
+    //! to collect the stats points to an event loaded locally and the counters
+    //! can therefore be calculated exactly using the locally available segment
+    //! of the timeline; true when the marker points to an event outside of
+    //! the local timeline (in which case the estimation is made basing on
+    //! the data supplied by the homeserver as well as counters saved from
+    //! the previous run of the client).
+    bool isEstimate = true;
+
+    // TODO: replace with = default once C++20 becomes a requirement on clients
+    bool operator==(const EventStats& rhs) const
+    {
+        return notableCount == rhs.notableCount
+               && highlightCount == rhs.highlightCount
+               && isEstimate == rhs.isEstimate;
+    }
+    bool operator!=(const EventStats& rhs) const { return !operator==(rhs); }
+
+    //! \brief Check whether the event statistics are empty
+    //!
+    //! Empty statistics have notable and highlight counters of zero and
+    //! isEstimate set to false.
+    Q_INVOKABLE bool empty() const
+    {
+        return notableCount == 0 && !isEstimate && highlightCount == 0;
+    }
+
+    using marker_t = Room::rev_iter_t;
+
+    //! \brief Build event statistics on a range of events
+    //!
+    //! This is a factory that returns an EventStats instance with counts of
+    //! notable and highlighted events between \p from and \p to reverse
+    //! timeline iterators; the \p init parameter allows to override
+    //! the initial statistics object and start from other values.
+    static EventStats fromRange(const Room* room, const marker_t& from,
+                                const marker_t& to,
+                                const EventStats& init = { 0, 0, false });
+
+    //! \brief Build event statistics on a range from sync edge to marker
+    //!
+    //! This is mainly a shortcut for \code
+    //! <tt>fromRange(room, marker_t(room->syncEdge()), marker)</tt>
+    //! \endcode except that it also sets isEstimate to true if (and only if)
+    //! <tt>to == room->historyEdge()</tt>.
+    static EventStats fromMarker(const Room* room, const marker_t& marker);
+
+    //! \brief Loads a statistics object from the cached counters
+    //!
+    //! Sets isEstimate to `true` unless both notableCount and highlightCount
+    //! are equal to -1.
+    static EventStats fromCachedCounters(Omittable<int> notableCount,
+                                         Omittable<int> highlightCount = none);
+
+    //! \brief Update statistics when a read marker moves down the timeline
+    //!
+    //! Removes events between oldMarker and newMarker from statistics
+    //! calculation if \p oldMarker points to an existing event in the timeline,
+    //! or recalculates the statistics entirely if \p oldMarker points
+    //! to <tt>room->historyEdge()</tt>. Always results in exact statistics
+    //! (<tt>isEstimate == false</tt>.
+    //! \param oldMarker Must point correspond to the _current_ statistics
+    //!        isEstimate state, i.e. it should point to
+    //!        <tt>room->historyEdge()</tt> if <tt>isEstimate == true</tt>, or
+    //!        to a valid position within the timeline otherwise
+    //! \param newMarker Must point to a valid position in the timeline (not to
+    //!        <tt>room->historyEdge()</tt> that is equal to or closer to
+    //!        the sync edge than \p oldMarker
+    //! \return true if either notableCount or highlightCount changed, or if
+    //!         the statistics was completely recalculated; false otherwise
+    bool updateOnMarkerMove(const Room* room, const marker_t& oldMarker,
+                            const marker_t& newMarker);
+
+    //! \brief Validate the statistics object against the given marker
+    //!
+    //! Checks whether the statistics object data are valid for a given marker.
+    //! No stats recalculation takes place, only isEstimate and zero-ness
+    //! of notableCount are checked.
+    bool isValidFor(const Room* room, const marker_t& marker) const;
+};
+
+QDebug operator<<(QDebug dbg, const EventStats& es);
+
+}