/* * Copyright 2016 The Cartographer Authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef CARTOGRAPHER_COMMON_TIME_H_ #define CARTOGRAPHER_COMMON_TIME_H_ #include <chrono> #include <ostream> #include <ratio> #include "cartographer/common/port.h" namespace cartographer { namespace common { constexpr int64 kUtsEpochOffsetFromUnixEpochInSeconds = (719162ll * 24ll * 60ll * 60ll); struct UniversalTimeScaleClock { using rep = int64; using period = std::ratio<1, 10000000>; using duration = std::chrono::duration<rep, period>; using time_point = std::chrono::time_point<UniversalTimeScaleClock>; static constexpr bool is_steady = true; }; // Represents Universal Time Scale durations and timestamps which are 64-bit // integers representing the 100 nanosecond ticks since the Epoch which is // January 1, 1 at the start of day in UTC. using Duration = UniversalTimeScaleClock::duration; using Time = UniversalTimeScaleClock::time_point; // Convenience functions to create common::Durations. Duration FromSeconds(double seconds); Duration FromMilliseconds(int64 milliseconds); // Returns the given duration in seconds. double ToSeconds(Duration duration); double ToSeconds(std::chrono::steady_clock::duration duration); // Creates a time from a Universal Time Scale. Time FromUniversal(int64 ticks); // Outputs the Universal Time Scale timestamp for a given Time. int64 ToUniversal(Time time); // For logging and unit tests, outputs the timestamp integer. std::ostream& operator<<(std::ostream& os, Time time); // CPU time consumed by the thread so far, in seconds. double GetThreadCpuTimeSeconds(); } // namespace common } // namespace cartographer #endif // CARTOGRAPHER_COMMON_TIME_H_