ahNow.H

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/*
                          Aleph_w
 
  Data structures & Algorithms
  version 2.0.0b
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
 
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
 
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
 
 
# ifndef AHNOW_H
# define AHNOW_H
 
# include <string>
# include <chrono>
 
# include <aleph.H>
 
namespace Aleph
{
  class Now
  {
  public:
    enum class Precision
      {
       Hours,
       Minutes,
       Seconds,
       Milliseconds,
       Microseconds,
       Nanoseconds
      };
 
    static int to_int(Precision p)
    {
      return static_cast<int>(p);
    }
    
    using ClockType = std::chrono::high_resolution_clock;
    using TimePointType = ClockType::time_point;
    using DurationType = ClockType::duration;
 
  private:
    TimePointType tp;
 
    Precision precision;
 
    static const double precision_values[];
    
  public:
    static TimePointType current_time_point()
    {
      return ClockType::now();
    }
 
    static double compute_time_diff(const TimePointType & rtp,
                                    const TimePointType & ltp,
                                    const Precision & precision)
    {
      DurationType et = std::chrono::duration_cast<std::chrono::nanoseconds>(rtp - ltp);
      return et.count() * precision_values[to_int(precision)];
    }
 
    Now(bool start_now = false)
      : tp(), precision(Precision::Milliseconds)
    {
      if (start_now)
        start();
    }
 
    Now(const Precision & _precision, bool start_now = false)
      : tp(), precision(_precision)
    {
      if (start_now)
        start();
    }
 
    const Precision & get_precision() const
    {
      return precision;
    }
 
    void set_precision(const Precision & _precision)
    {
      precision = _precision;
    }
 
    TimePointType start()
    {
      tp = this->current_time_point();
      return tp;
    }
 
    double elapsed()
    {
      TimePointType ltp = tp;
      tp = this->current_time_point();
      return compute_time_diff(tp, ltp, precision);
    }
 
    double delta()
    {
      return elapsed();
    }
 
    static double elapsed(const TimePointType & tp,
                          const Precision & precision = Precision::Milliseconds)
    {
      return compute_time_diff(current_time_point(), tp, precision);
    }
 
    static double delta(const TimePointType & tp,
                        const Precision & precision = Precision::Milliseconds)
    {
      return elapsed(tp, precision);
    }
  };  
} // End namespace Aleph
  
# endif // AHNOW_H