Reduce horizontal graphs resolution

Rewrite averaging code and reduce horizontal graphs resolution for
30 minutes and 6 hours graphs to decrease CPU usage.

src/gui/properties/speedplotview.cpp

@@ -33,15 +33,67 @@
 #include "base/global.h"
 #include "base/utils/misc.h"
 
+namespace
+{
+    enum PeriodInSeconds
+    {
+        MIN1_SEC = 60,
+        MIN5_SEC = 5 * 60,
+        MIN30_SEC = 30 * 60,
+        HOUR6_SEC = 6 * 60 * 60
+    };
+
+    const int MIN5_BUF_SIZE = 5 * 60;
+    const int MIN30_BUF_SIZE = 5 * 60;
+    const int HOUR6_BUF_SIZE = 5 * 60;
+    const int DIVIDER_30MIN = MIN30_SEC / MIN30_BUF_SIZE;
+    const int DIVIDER_6HOUR = HOUR6_SEC / HOUR6_BUF_SIZE;
+}
+
+SpeedPlotView::Averager::Averager(int divider, boost::circular_buffer<PointData> &sink)
+    : m_divider(divider)
+    , m_sink(sink)
+    , m_counter(0)
+    , m_accumulator {}
+{
+}
+
+void SpeedPlotView::Averager::push(const PointData &pointData)
+{
+    // Accumulator overflow will be hit in worst case on longest used averaging span,
+    // defined by divider value. Maximum divider is DIVIDER_6HOUR = 72
+    // Using int32 for accumulator we get overflow when transfer speed reaches 2^31/72 ~~ 28.4 MBytes/s.
+    // With quint64 this speed limit is 2^64/72 ~~ 228 PBytes/s.
+    // This speed is inaccessible to an ordinary user.
+    m_accumulator.x += pointData.x;
+    for (int id = UP; id < NB_GRAPHS; ++id)
+        m_accumulator.y[id] += pointData.y[id];
+    m_counter = (m_counter + 1) % m_divider;
+    if (m_counter != 0)
+        return; // still accumulating
+    // it is time final averaging calculations
+    for (int id = UP; id < NB_GRAPHS; ++id)
+        m_accumulator.y[id] /= m_divider;
+    m_accumulator.x /= m_divider;
+    // now flush out averaged data
+    m_sink.push_back(m_accumulator);
+    m_accumulator = {};
+}
+
+bool SpeedPlotView::Averager::isReady() const
+{
+    return m_counter == 0;
+}
+
 SpeedPlotView::SpeedPlotView(QWidget *parent)
     : QGraphicsView(parent)
     , m_data5Min(MIN5_BUF_SIZE)
     , m_data30Min(MIN30_BUF_SIZE)
     , m_data6Hour(HOUR6_BUF_SIZE)
+    , m_averager30Min(DIVIDER_30MIN, m_data30Min)
+    , m_averager6Hour(DIVIDER_6HOUR, m_data6Hour)
     , m_period(MIN5)
     , m_viewablePointsCount(MIN5_SEC)
-    , m_counter30Min(-1)
-    , m_counter6Hour(-1)
 {
     QPen greenPen;
     greenPen.setWidthF(1.5);
@@ -80,30 +132,11 @@ void SpeedPlotView::setGraphEnable(GraphID id, bool enable)
     viewport()->update();
 }
 
-void SpeedPlotView::pushPoint(SpeedPlotView::PointData point)
+void SpeedPlotView::pushPoint(const SpeedPlotView::PointData &point)
 {
-    m_counter30Min = (m_counter30Min + 1) % 3;
-    m_counter6Hour = (m_counter6Hour + 1) % 18;
-
     m_data5Min.push_back(point);
-
+    m_averager30Min.push(point);
-    if (m_counter30Min == 0) {
+    m_averager6Hour.push(point);
-        m_data30Min.push_back(point);
-    }
-    else {
-        m_data30Min.back().x = (m_data30Min.back().x * m_counter30Min + point.x) / (m_counter30Min + 1);
-        for (int id = UP; id < NB_GRAPHS; ++id)
-            m_data30Min.back().y[id] = (m_data30Min.back().y[id] * m_counter30Min + point.y[id]) / (m_counter30Min + 1);
-    }
-
-    if (m_counter6Hour == 0) {
-        m_data6Hour.push_back(point);
-    }
-    else {
-        m_data6Hour.back().x = (m_data6Hour.back().x * m_counter6Hour + point.x) / (m_counter6Hour + 1);
-        for (int id = UP; id < NB_GRAPHS; ++id)
-            m_data6Hour.back().y[id] = (m_data6Hour.back().y[id] * m_counter6Hour + point.y[id]) / (m_counter6Hour + 1);
-    }
 }
 
 void SpeedPlotView::setViewableLastPoints(TimePeriod period)
@@ -132,8 +165,8 @@ void SpeedPlotView::replot()
 {
     if ((m_period == MIN1)
         || (m_period == MIN5)
-        || ((m_period == MIN30) && (m_counter30Min == 2))
+        || ((m_period == MIN30) && m_averager30Min.isReady())
-        || ((m_period == HOUR6) && (m_counter6Hour == 17)))
+        || ((m_period == HOUR6) && m_averager6Hour.isReady()) )
         viewport()->update();
 }
 
@@ -151,11 +184,11 @@ boost::circular_buffer<SpeedPlotView::PointData> &SpeedPlotView::getCurrentData(
     }
 }
 
-int SpeedPlotView::maxYValue()
+quint64 SpeedPlotView::maxYValue()
 {
     boost::circular_buffer<PointData> &queue = getCurrentData();
 
-    int maxYValue = 0;
+    quint64 maxYValue = 0;
     for (int id = UP; id < NB_GRAPHS; ++id) {
 
         if (!m_properties[static_cast<GraphID>(id)].enable)
@@ -179,7 +212,7 @@ void SpeedPlotView::paintEvent(QPaintEvent *)
 
     rect.adjust(4, 4, 0, -4); // Add padding
 
-    int maxY = maxYValue();
+    quint64 maxY = maxYValue();
 
     rect.adjust(0, fontMetrics.height(), 0, 0); // Add top padding for top speed text
 

src/gui/properties/speedplotview.h

@@ -70,7 +70,7 @@ public:
     struct PointData
     {
         qint64 x;
-        int y[NB_GRAPHS];
+        quint64 y[NB_GRAPHS];
     };
 
     explicit SpeedPlotView(QWidget *parent = nullptr);
@@ -78,7 +78,7 @@ public:
     void setGraphEnable(GraphID id, bool enable);
     void setViewableLastPoints(TimePeriod period);
 
-    void pushPoint(PointData point);
+    void pushPoint(const PointData &point);
 
     void replot();
 
@@ -86,19 +86,18 @@ protected:
     void paintEvent(QPaintEvent *event) override;
 
 private:
-    enum PeriodInSeconds
+    class Averager
     {
-        MIN1_SEC = 60,
+    public:
-        MIN5_SEC = 5 * 60,
+        Averager(int divider, boost::circular_buffer<PointData> &sink);
-        MIN30_SEC = 30 * 60,
+        void push(const PointData &pointData);
-        HOUR6_SEC = 6 * 60 * 60
+        bool isReady() const;
-    };
 
-    enum PointsToSave
+    private:
-    {
+        const int m_divider;
-        MIN5_BUF_SIZE = 5 * 60,
+        boost::circular_buffer<PointData> &m_sink;
-        MIN30_BUF_SIZE = 10 * 60,
+        int m_counter;
-        HOUR6_BUF_SIZE = 20 * 60
+        PointData m_accumulator;
     };
 
     struct GraphProperties
@@ -111,19 +110,19 @@ private:
         bool enable;
     };
 
-    int maxYValue();
+    quint64 maxYValue();
     boost::circular_buffer<PointData> &getCurrentData();
 
     boost::circular_buffer<PointData> m_data5Min;
     boost::circular_buffer<PointData> m_data30Min;
     boost::circular_buffer<PointData> m_data6Hour;
+    Averager m_averager30Min;
+    Averager m_averager6Hour;
+
     QMap<GraphID, GraphProperties> m_properties;
 
     TimePeriod m_period;
     int m_viewablePointsCount;
-
-    int m_counter30Min;
-    int m_counter6Hour;
 };
 
 #endif // SPEEDPLOTVIEW_H