Visual Benchmarking Cherno Example

#include <string>
#include <chrono>
#include <algorithm>
#include <fstream>
#include <thread>
#include <iostream>

struct ProfileResult
{
    std::string Name;
    long long Start, End;
    uint32_t ThreadID;
};

struct InstrumentationSession
{
    std::string Name;
};

class Instrumentor
{
private:
    InstrumentationSession* m_CurrentSession;
    std::ofstream m_OutputStream;
    int m_ProfileCount;
public:
    Instrumentor()
        : m_CurrentSession(nullptr), m_ProfileCount(0)
    {
    }

    void BeginSession(const std::string& name, const std::string& filepath = "results.json")
    {
        m_OutputStream.open(filepath);
        WriteHeader();
        m_CurrentSession = new InstrumentationSession{ name };
    }

    void EndSession()
    {
        WriteFooter();
        m_OutputStream.close();
        delete m_CurrentSession;
        m_CurrentSession = nullptr;
        m_ProfileCount = 0;
    }

    void WriteProfile(const ProfileResult& result)
    {
        if (m_ProfileCount++ > 0)
            m_OutputStream << ",";

        std::string name = result.Name;
        std::replace(name.begin(), name.end(), '"', '\'');

        m_OutputStream << "{";
        m_OutputStream << "\"cat\":\"function\",";
        m_OutputStream << "\"dur\":" << (result.End - result.Start) << ',';
        m_OutputStream << "\"name\":\"" << name << "\",";
        m_OutputStream << "\"ph\":\"X\",";
        m_OutputStream << "\"pid\":0,";
        m_OutputStream << "\"tid\":" << result.ThreadID << ",";
        m_OutputStream << "\"ts\":" << result.Start;
        m_OutputStream << "}";

        m_OutputStream.flush();
    }

    void WriteHeader()
    {
        m_OutputStream << "{\"otherData\": {},\"traceEvents\":[";
        m_OutputStream.flush();
    }

    void WriteFooter()
    {
        m_OutputStream << "]}";
        m_OutputStream.flush();
    }

    static Instrumentor& Get()
    {
        static Instrumentor instance;
        return instance;
    }
};

class InstrumentationTimer
{
public:
    InstrumentationTimer(const char* name)
        : m_Name(name), m_Stopped(false)
    {
        m_StartTimepoint = std::chrono::high_resolution_clock::now();
    }

    ~InstrumentationTimer()
    {
        if (!m_Stopped)
            Stop();
    }

    void Stop()
    {
        auto endTimepoint = std::chrono::high_resolution_clock::now();

        long long start = std::chrono::time_point_cast<std::chrono::microseconds>(m_StartTimepoint).time_since_epoch().count();
        long long end = std::chrono::time_point_cast<std::chrono::microseconds>(endTimepoint).time_since_epoch().count();

        uint32_t threadID = std::hash<std::thread::id>{}(std::this_thread::get_id());
        Instrumentor::Get().WriteProfile({ m_Name, start, end, threadID });

        m_Stopped = true;
    }
private:
    const char* m_Name;
    std::chrono::time_point<std::chrono::high_resolution_clock> m_StartTimepoint;
    bool m_Stopped;
};

#define PROFILING 1
#if PROFILING
#define PROFILE_SCOPE(name) InstrumentationTimer timer##__LINE__(name)
#define PROFILE_FUNCTION() PROFILE_SCOPE(__FUNCSIG__)
#else
#define PROFILE_SCOPE(name)
#endif

namespace Benchmark
{
    void PrintFunction(int value)
    {
        PROFILE_FUNCTION();

        for (int i = 0; i < 1000; i++)
            std::cout << "Hello World #" << i << std::endl;
    }

    void PrintFunction()
    {
        PROFILE_FUNCTION();

        for (int i = 0; i < 1000; i++)
            std::cout << "Hello World #" << sqrt(i) << std::endl;
    }

    void RunBenchmarks()
    {
        PROFILE_FUNCTION();

        std::cout << "Running Benchmarks....\n";
        std::thread a([]() {PrintFunction(2); });
        PrintFunction();

        a.join();
    }
}

int main()
{
    Instrumentor::Get().BeginSession("Profile");
    Benchmark::RunBenchmarks();
    Instrumentor::Get().EndSession();

    std::cin.get();
}