moonfire-nvr/src/time.h
2016-01-01 22:06:47 -08:00

75 lines
2.4 KiB
C++

// This file is part of Moonfire NVR, a security camera digital video recorder.
// Copyright (C) 2016 Scott Lamb <slamb@slamb.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// In addition, as a special exception, the copyright holders give
// permission to link the code of portions of this program with the
// OpenSSL library under certain conditions as described in each
// individual source file, and distribute linked combinations including
// the two.
//
// You must obey the GNU General Public License in all respects for all
// of the code used other than OpenSSL. If you modify file(s) with this
// exception, you may extend this exception to your version of the
// file(s), but you are not obligated to do so. If you do not wish to do
// so, delete this exception statement from your version. If you delete
// this exception statement from all source files in the program, then
// also delete it here.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// time.h: functions dealing with (wall) time.
#ifndef MOONFIRE_NVR_TIME_H
#define MOONFIRE_NVR_TIME_H
#include <math.h>
#include <time.h>
#include <mutex>
namespace moonfire_nvr {
constexpr long kNanos = 1000000000;
class WallClock {
public:
virtual ~WallClock() {}
virtual struct timespec Now() const = 0;
virtual void Sleep(struct timespec) = 0;
};
class SimulatedClock : public WallClock {
public:
SimulatedClock() : now_({0, 0}) {}
struct timespec Now() const final;
void Sleep(struct timespec req) final;
private:
mutable std::mutex mu_;
struct timespec now_;
};
inline struct timespec SecToTimespec(double sec) {
double intpart;
double fractpart = modf(sec, &intpart);
return {static_cast<time_t>(intpart), static_cast<long>(fractpart * kNanos)};
}
// Returns the real wall clock, which will never be deleted.
WallClock *GetRealClock();
} // namespace moonfire_nvr
#endif // MOONFIRE_NVR_TIME_H