Time.h

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/*
 * SWC-DB© Copyright since 2019 Alex Kashirin <kashirin.alex@gmail.com>
 * License details at <https://github.com/kashirin-alex/swc-db/#license>
 */
 
 
#ifndef swcdb_core_Time_h
#define swcdb_core_Time_h
 
 
#include "swcdb/core/Compat.h"
#include <chrono>
 
 
namespace SWC {
 
 
namespace Time {
 
 
static_assert(
  std::ratio_less_equal<
    std::chrono::system_clock::duration::period,
    std::chrono::nanoseconds::period
  >::value
);
 
 
SWC_CAN_INLINE
extern
int64_t now_ms() noexcept {
  return std::chrono::duration_cast<std::chrono::milliseconds>(
    std::chrono::system_clock::now().time_since_epoch()).count();
}
 
SWC_CAN_INLINE
extern
int64_t now_ns() noexcept {
  return std::chrono::duration_cast<std::chrono::nanoseconds>(
    std::chrono::system_clock::now().time_since_epoch()).count();
}
 
int64_t parse_ns(int& err, const std::string& buf);
 
std::string fmt_ns(int64_t ns);
 
 
 
template<typename ClockT, typename DurationT>
struct Measure : std::chrono::time_point<ClockT> {
 
  SWC_CAN_INLINE
  Measure() noexcept
          : std::chrono::time_point<ClockT>(ClockT::now()) {
  }
 
  constexpr SWC_CAN_INLINE
  Measure(typename std::chrono::time_point<ClockT>::duration&& v) noexcept
          : std::chrono::time_point<ClockT>(v) {
  }
 
  SWC_CAN_INLINE
  void restart() noexcept {
    std::chrono::time_point<ClockT>::operator=(ClockT::now());
  }
 
  template<typename T = DurationT>
  SWC_CAN_INLINE
  uint64_t elapsed() const noexcept {
    return std::chrono::duration_cast<T>(ClockT::now() - *this).count();
  }
 
};
 
typedef Measure<std::chrono::steady_clock, std::chrono::nanoseconds>
  Measure_ns;
typedef Measure<std::chrono::steady_clock, std::chrono::microseconds>
  Measure_us;
typedef Measure<std::chrono::steady_clock, std::chrono::milliseconds>
  Measure_ms;
typedef Measure<std::chrono::steady_clock, std::chrono::seconds>
  Measure_sec;
 
 
}}
 
 
 
#ifdef SWC_IMPL_SOURCE
#include "swcdb/core/Time.cc"
#endif
 
#endif // swcdb_core_Time_h