用于方便地测量代码运行时间的 C++ class Timer

Timer.hpp

//
//  Timer.h
//  NLE
//
//  Created by Guo Shuai on 2023/7/27.
//

#ifndef Timer_h
#define Timer_h

#include <chrono>
#include <iostream>
#include <string>
#include <map>

#define TIMER_LOG 0

class Timer {
  struct Stat {
    std::chrono::time_point<std::chrono::high_resolution_clock> start;
    long long total_duration = 0;
    long long mean_duration  = 0;
    int count                = 0;
  };

 public:
  // Get the Timer Singleton
  static Timer* Get() {
    static Timer timer;
    return &timer;
  }

  // Print all mean durations
  void PrintMeanTimes(int n) {
    for (const auto& [name, stat] : stats_) {
#if TIMER_LOG
      printf("[Timer Summary] %s mean time: %lldms\n", name.c_str(), stat.total_duration / (1000 * n));
#endif
    }
  }

  void Start(const std::string& name) {
    stats_[name].start = std::chrono::high_resolution_clock::now();
  }

  void End(const std::string& name) {
    auto end           = std::chrono::high_resolution_clock::now();
    auto start         = stats_[name].start;
    long long duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start).count();
    stats_[name].total_duration += duration;
    stats_[name].count++;
#if TIMER_LOG
    printf("[Timer] %s time: %lldms\n", name.c_str(), duration / 1000);
#endif
  }

 private:
  std::map<std::string, Stat> stats_;
};

#endif /* Timer_h */

使用方法：

Timer::Get()->Start("Job 1");
// ...
// Job 1 code
// ...
Timer::Get()->End("Job 1");

Print the summary:

Timer::Get()->PrintMeanTimes(10);