refactor: extract lib_timer

lib_timer/CMakeLists.txt

@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.20)
+
+project(
+  timer
+  VERSION 0.1.0
+  LANGUAGES CXX)
+
+add_library(timer STATIC src/timer.cpp include/timer.h)
+
+target_include_directories(timer PUBLIC ${PROJECT_SOURCE_DIR}/include)
+
+target_compile_features(timer PUBLIC cxx_std_20)

lib_timer/include/timer.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <chrono>
+#include <ostream>
+
+class Timer {
+private:
+  std::chrono::time_point<std::chrono::high_resolution_clock> start_;
+  std::chrono::time_point<std::chrono::high_resolution_clock> end_;
+
+public:
+  Timer();
+
+  void start();
+  void stop();
+
+  long us() const;
+};
+
+std::ostream &operator<<(std::ostream &os, const Timer &timer);

lib_timer/src/timer.cpp

@@ -0,0 +1,32 @@
+#include "timer.h"
+
+#include <chrono>
+
+Timer::Timer() { start(); };
+
+void Timer::start() { start_ = std::chrono::high_resolution_clock::now(); }
+
+void Timer::stop() { end_ = std::chrono::high_resolution_clock::now(); }
+
+long Timer::us() const {
+  return std::chrono::duration_cast<std::chrono::microseconds>(end_ - start_)
+      .count();
+}
+
+std::ostream &operator<<(std::ostream &os, const Timer &timer) {
+  long time = timer.us();
+
+  if (time >= 1e6) {
+    os << time / static_cast<long>(1e6) << " s ";
+    time %= static_cast<long>(1e6);
+  }
+
+  if (time >= 1e3) {
+    os << time / static_cast<long>(1e3) << " ms ";
+    time %= static_cast<long>(1e3);
+  }
+
+  os << time << " µs";
+
+  return os;
+}