timer.hpp

// SPDX-License-Identifier: MIT
#ifndef LIBSBX_UTILITY_TIMER_HPP_
#define LIBSBX_UTILITY_TIMER_HPP_
 
#include <chrono>
#include <cmath>
#include <functional>
#include <type_traits>
 
#include <libsbx/units/time.hpp>
 
namespace sbx::utility {
 
class timer {
 
public:
 
  timer();
 
  ~timer() = default;
 
  auto elapsed() noexcept -> units::second;
 
private:
 
  std::chrono::time_point<std::chrono::high_resolution_clock> _start{};
 
}; // class timer
 
class scoped_timer {
 
public:
 
  template<typename Callable>
  requires (std::is_invocable_v<Callable, const units::second&>)
  scoped_timer(Callable&& callable)
  : _on_destroy{std::forward<Callable>(callable)},
    _start{std::chrono::high_resolution_clock::now()} { }
 
  ~scoped_timer() {
    if (_on_destroy) {
      const auto now = std::chrono::high_resolution_clock::now();
      const auto elapsed = units::second{std::chrono::duration_cast<std::chrono::duration<std::float_t>>(now - _start).count()};
      
      std::invoke(_on_destroy, elapsed);
    }
  }
 
private:
 
  std::function<void(const units::second&)> _on_destroy;
  std::chrono::time_point<std::chrono::high_resolution_clock> _start;
 
}; // class scoped_timer
 
} // namespace sbx::utility
 
#endif // LIBSBX_UTILITY_TIMER_HPP_