class mola::MetricChannelImpl

Overview

Concrete MetricChannel : a bounded, thread-safe rolling buffer of samples.

Modelled on ConsoleLogSink : a shared_ptr sink written to by producer threads and read by the GUI thread, a rolling buffer bounded by time, a lock-free version() change hint, and an atomic gate letting producers early-out cheaply while nobody is plotting.

#include <MetricsRegistry.h>

class MetricChannelImpl: public mola::MetricChannel
{
public:
    // typedefs

    typedef std::shared_ptr<MetricChannelImpl> Ptr;

    // fields

    const std::string name;
    const std::string unit;
    const ImVec4 color;
    std::atomic<double> retention_seconds {10.0};

    // construction

    MetricChannelImpl(
        std::string channelName,
        std::string channelUnit,
        ImVec4 channelColor,
        std::shared_ptr<std::atomic<bool>> anyWindowOpen
        );

    // methods

    virtual void push(double t, double value);
    void copy_span(double t_min, std::vector<double>& xs, std::vector<double>& ys) const;
    uint64_t version() const;
};

Inherited Members

public:
    // typedefs

    typedef std::shared_ptr<MetricChannel> Ptr;

    // methods

    MetricChannel& operator = (const MetricChannel&);
    MetricChannel& operator = (MetricChannel&&);
    virtual void push(double t, double value) = 0;
    void push(double value);

Fields

std::atomic<double> retention_seconds {10.0}

Rolling history length; the widest span among all plot windows currently showing this channel (capped by nothing here callers decide the cap; default 10 s, see MolaVizImGuiCore::plots_default_retention_seconds_).

Methods

virtual void push(double t, double value)

Appends one sample.

Parameters:

t	Timestamp in seconds, using any monotonic clock consistent across calls for this channel. Using wall-clock time (mrpt::Clock::nowDouble()) is recommended so multiple channels can share a common x-axis.
value	Sample value.

void copy_span(double t_min, std::vector<double>& xs, std::vector<double>& ys) const

Appends the samples with t >= t_min to the (caller-owned, reused) output buffers, oldest first. Both buffers use double ImPlot’s PlotLine()/PlotScatter() require the x and y arrays to share one type.

uint64_t version() const

Bumped on every push(). Lock-free, so the renderer can skip copy_span() when nothing changed since the last rendered frame.