lsst.daf.base  22.0.1+771eb1e3e8
DateTime.h
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1 // -*- lsst-c++ -*-
2 
3 /*
4  * LSST Data Management System
5  * Copyright 2008, 2009, 2010 LSST Corporation.
6  *
7  * This product includes software developed by the
8  * LSST Project (http://www.lsst.org/).
9  *
10  * This program is free software: you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
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24 
25 #ifndef LSST_DAF_BASE_DATETIME_H
26 #define LSST_DAF_BASE_DATETIME_H
27 
44 #include <cstdint>
45 #include <ctime>
46 #include <limits>
47 #include <sys/time.h>
48 #include <string>
49 
50 #include "lsst/base.h"
51 #include "lsst/pex/exceptions.h"
52 
53 // Forward declaration of the boost::serialization::access class.
54 namespace boost {
55 namespace serialization {
56 class access;
57 }
58 } // namespace boost
59 
60 namespace lsst {
61 namespace daf {
62 namespace base {
63 
65 public:
66  enum DateSystem { JD = 0, MJD, EPOCH }; // EPOCH is Julian epoch year
67  // e.g. 2000.0 for J2000
68  enum Timescale {
69  TAI = 5,
70  UTC,
71  TT
72  }; // use values that do not overlap DateSystem
73  // to avoid confusing one for the other in Python
74  // an invalid DateTime has _nsec == invalid_nsecs
75  constexpr static long long invalid_nsecs = std::numeric_limits<std::int64_t>::min();
76 
80  explicit DateTime();
81 
91  explicit DateTime(long long nsecs, Timescale scale = TAI);
92 
101  explicit DateTime(double date, DateSystem system = MJD, Timescale scale = TAI);
102 
116  DateTime(int year, int month, int day, int hr, int min, int sec, Timescale scale = TAI);
117 
134  explicit DateTime(std::string const& iso8601, Timescale scale);
135 
146  long long nsecs(Timescale scale = TAI) const;
147 
157  double get(DateSystem system = MJD, Timescale scale = TAI) const;
158 
169  std::string toString(Timescale scale) const;
170 
178  struct tm gmtime(Timescale scale) const;
179 
188  struct timespec timespec(Timescale scale) const;
189 
198  struct timeval timeval(Timescale scale) const;
199 
203  bool isValid() const { return _nsecs != DateTime::invalid_nsecs; };
204 
205  bool operator==(DateTime const& rhs) const;
206 
208  std::size_t hash_value() const noexcept;
209 
214  static DateTime now(void);
215 
224  static void initializeLeapSeconds(std::string const& leapString);
225 
226 private:
227  long long _nsecs;
228 
230  void _assertValid() const {
231  if (!isValid()) {
232  throw LSST_EXCEPT(pex::exceptions::RuntimeError, "DateTime not valid");
233  }
234  }
235 
243  double _getMjd(Timescale scale) const;
244 
252  double _getJd(Timescale scale) const;
253 
262  double _getEpoch(Timescale scale) const;
263 
271  void setNsecsFromMjd(double mjd, Timescale scale);
272 
280  void setNsecsFromJd(double jd, Timescale scale);
281 
289  void setNsecsFromEpoch(double epoch, Timescale scale);
290 
291  friend class boost::serialization::access;
292 
299  template <class Archive>
300  void serialize(Archive ar, int const version) {
301  ar& _nsecs;
302  }
303 };
304 
305 } // namespace base
306 } // namespace daf
307 } // namespace lsst
308 
309 namespace std {
310 template <>
311 struct hash<lsst::daf::base::DateTime> {
314  size_t operator()(argument_type const& obj) const noexcept { return obj.hash_value(); }
315 };
316 } // namespace std
317 
318 #endif
#define LSST_EXCEPT(type,...)
#define LSST_EXPORT
Class for handling dates/times, including MJD, UTC, and TAI.
Definition: DateTime.h:64
bool isValid() const
Is this date valid?
Definition: DateTime.h:203
constexpr static long long invalid_nsecs
Definition: DateTime.h:75
T min(T... args)
Definition: DateTime.h:54
STL namespace.
size_t operator()(argument_type const &obj) const noexcept
Definition: DateTime.h:314