Profiler.h

// Copy of source from DABC Profiler
 
#ifndef BASE_PROFILER_H
#define BASE_PROFILER_H
 
#include <string>
#include <vector>
 
namespace base {
 
   class ProfilerGuard;
 
   class Profiler {
 
      friend class ProfilerGuard;
 
      typedef unsigned long long clock_t;
 
      bool fActive{true};
 
      clock_t GetClock()
      {
 
#ifdef STREAM_AARCH64
         uint64_t virtual_timer_value;
         asm volatile("mrs %0, cntvct_el0" : "=r"(virtual_timer_value));
         return virtual_timer_value;
#else
         unsigned low, high;
         asm volatile ("rdtsc" : "=a" (low), "=d" (high));
         return (clock_t(high) << 32) | low;
#endif
      }
 
      clock_t fLast{0};
 
      struct Entry {
         clock_t fSum{0};           
         double fRatio{0.};         
         std::string fName;         
      };
 
      std::vector<Entry>  fEntries;  
 
   public:
 
      Profiler() { Reserve(10); }
 
      void Reserve(unsigned num = 10)
      {
         while (fEntries.size() < num)
            fEntries.emplace_back();
      }
 
      void SetActive(bool on = true) { fActive = on; }
 
      void MakeStatistic();
 
      std::string Format();
 
   };
 
   class ProfilerGuard {
      Profiler &fProfiler;       
      unsigned fCnt{0};          
      Profiler::clock_t fLast{0}; 
 
   public:
      ProfilerGuard(Profiler &prof, const char *name = nullptr, unsigned lvl = 0) : fProfiler(prof), fCnt(lvl)
      {
         if (!fProfiler.fActive || (fCnt >= fProfiler.fEntries.size()))
            return;
 
         fLast = fProfiler.GetClock();
 
         if (name && fProfiler.fEntries[fCnt].fName.empty())
            fProfiler.fEntries[fCnt].fName = name;
      }
 
      ~ProfilerGuard()
      {
         Next();
      }
 
      void Next(const char *name = nullptr, unsigned lvl = 0)
      {
         if (!fProfiler.fActive || (fCnt >= fProfiler.fEntries.size()))
            return;
 
         auto now = fProfiler.GetClock();
 
         fProfiler.fEntries[fCnt].fSum += (now - fLast);
 
         fLast = now;
 
         if (lvl) fCnt = lvl; else fCnt++;
 
         if (name && (fCnt < fProfiler.fEntries.size()) && fProfiler.fEntries[fCnt].fName.empty())
            fProfiler.fEntries[fCnt].fName = name;
      }
 
   };
 
} // namespace dabc
 
#endif