Simple (intrusive) OSG profiler

README.md

Requires:

• to define Profiler::ProfileMap Profiler::_profile; somewhere
• to scope blocks of code with { Profiler p("block label"); ... }; do not use an anonymous variable otherwise the timer will be wrong as anonymous object will be deleted at the end of the instruction (see http://stackoverflow.com/a/2298796/626278)
• to call Profiler::dump() to dump profiling stats in /tmp/profile

Profiler

#ifndef PROFILER
#define PROFILER

#include <map>
#include <string>
#include <utility>
#include <fstream>
#include <iomanip>

#include <osg/Timer>
#include <osg/Notify>


class Profiler
{
public:
    typedef std::pair<unsigned int, double> ProfileStat;
    typedef std::map< std::string, ProfileStat> ProfileMap;
    typedef std::pair<std::string, ProfileStat> ProfileItem;
    static ProfileMap _profile;

    enum SortFilter {
        by_name=1,
        by_calls=2,
        by_seconds=4
    };

    struct profile_item_sort
    {
        profile_item_sort(SortFilter filter): _filter(filter)
        {}

        inline bool operator() (const ProfileItem& item1, const ProfileItem& item2)
        {
            if(_filter & by_name) {
                return (item1.first < item2.first);
            }
            else if(_filter & by_calls) {
                return (item1.second.first > item2.second.first);
            }

            return (item1.second.second > item2.second.second);
        }

        SortFilter _filter;
    };
    
    static void dump(SortFilter filter=by_seconds) {
        std::ofstream out("/tmp/profile");
        std::vector<ProfileItem> data(Profiler::_profile.begin(), Profiler::_profile.end());

        if(filter) {
            std::sort(data.begin(), data.end(), profile_item_sort(filter));
        }

        out << std::setw(30) << "label" << " " << std::setw(10) << "#calls" << " " << "seconds" << std::endl;
        for(std::vector<ProfileItem>::const_iterator item = data.begin() ; item != data.end() ; ++ item) {
            out << std::setw(30) << item->first << " "
                << std::setw(10) << item->second.first << " "
                << std::setprecision(6) << item->second.second << std::endl;
        }
    }

    Profiler(const std::string& label): _start(getTick()), _label(label) 
    {}

    ~Profiler() {
        _stop = getTick();
        double seconds = getElapsedSeconds();

        std::map< std::string, std::pair<unsigned int, double> >::iterator func = Profiler::_profile.find(_label);
        if(Profiler::_profile.find(_label) == Profiler::_profile.end()) {
            _profile.insert(ProfileItem(_label, std::pair<unsigned int, double>(1, seconds)));
        }
        else {
            func->second.first += 1;
            func->second.second += seconds;
        }
    }

protected:
    osg::Timer_t _start, _stop;
    std::string _label;

    inline osg::Timer_t getTick() const {
        return osg::Timer::instance()->tick();
    }

    inline double getElapsedSeconds() const {
        return osg::Timer::instance()->delta_s(_start, _stop);
    }
};

#endif