rollingbuffer.hpp

#ifndef ROLLINGBUFFER_HPP
#define ROLLINGBUFFER_HPP
        //
#include "base.hpp"
#include "stats.hpp"
#include "xmltraversal.h"
        //
    class UTILITYSHARED_EXPORT RollingBuffer
        {
                int Width;
                //
                QList<double> buffer;
                //
                bool changed; // if true stats need to be recalculated
                StatisticsThresholdSet stats; // the current statistic of the buffer
                //
                public:
                RollingBuffer( int w = 8) : Width(w){}
                RollingBuffer(const RollingBuffer &r) :
                        Width(r.Width),buffer(r.buffer),
                        changed(r.changed),stats(r.stats){}

                void clearBuffer()
                {
                        stats.clear();
                        buffer.clear();
                };
                //
                int getWidth() const { return Width;}
                //
                void setWidth(int w)
                {
                    if(w > 0)
                    {
                        Width = w;
                        if(buffer.count() > w)
                        {
                                while(buffer.count() > w) buffer.pop_front();
                                changed = true;
                        }
                     }
                }

                StatisticsThresholdSet & readStatistics() { return stats;}
                StatisticsThresholdSet & getStatistics()
                {
                        if(changed)
                        {
                                // recalculate if necessary
                                stats.clear();
                                for(int i = 0; i < buffer.count(); i++)
                                {
                                        stats.setValue(buffer.value(i));
                                };
                        };
                        changed = false;
                        return stats;
                };
                // this does not invert - maybe change for persistance
                XMLTraversal & toXML(XMLTraversal &x)
                {
                        getStatistics();
                        return stats.toXML(x);
                };

                XMLTraversal & fromXML(XMLTraversal &x)
                {
                        return stats.fromXML(x);
                };

                void addValue(double v)
                {
                        changed = true;
                        buffer.push_back(v);
                        if(buffer.count() > Width)
                        {
                                while(buffer.count() > Width) buffer.pop_front();
                        };
                };
                friend QDataStream & operator >> (QDataStream &is, RollingBuffer &r);
                friend QDataStream & operator << (QDataStream &os, const RollingBuffer &r);
        };
        inline QDataStream & operator >> (QDataStream &is, RollingBuffer &r)
        {
                int w;
                is >> w;
                r.setWidth(w);
                r.buffer.clear();
                is >> r.buffer;
                r.changed = true;
                return is;
        };
        inline QDataStream & operator << (QDataStream &os, const RollingBuffer &r)
        {
                os << r.getWidth();
                os << r.buffer;
                return os;
        };
#endif

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