lsst.daf.base  16.0-4-g50d071e+7
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/).
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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/pex/exceptions.h"
51 
52 // Forward declaration of the boost::serialization::access class.
53 namespace boost {
54 namespace serialization {
55 class access;
56 }
57 } // namespace boost
58 
59 namespace lsst {
60 namespace daf {
61 namespace base {
62 
63 class DateTime {
64 public:
65  enum DateSystem { JD = 0, MJD, EPOCH };
66  enum Timescale {
67  TAI = 5,
68  UTC,
69  TT
70  }; // use values that do not overlap DateSystem
71  // to avoid confusing one for the other in Python
72  // an invalid DateTime has _nsec == invalid_nsecs
73  constexpr static long long invalid_nsecs = std::numeric_limits<std::int64_t>::min();
74 
78  explicit DateTime();
79 
89  explicit DateTime(long long nsecs, Timescale scale = TAI);
90 
99  explicit DateTime(double date, DateSystem system = MJD, Timescale scale = TAI);
100 
114  DateTime(int year, int month, int day, int hr, int min, int sec, Timescale scale = TAI);
115 
132  explicit DateTime(std::string const& iso8601, Timescale scale);
133 
144  long long nsecs(Timescale scale = TAI) const;
145 
155  double get(DateSystem system = MJD, Timescale scale = TAI) const;
156 
167  std::string toString(Timescale scale) const;
168 
176  struct tm gmtime(Timescale scale) const;
177 
186  struct timespec timespec(Timescale scale) const;
187 
196  struct timeval timeval(Timescale scale) const;
197 
201  bool isValid() const { return _nsecs != DateTime::invalid_nsecs; };
202 
203  bool operator==(DateTime const& rhs) const;
204 
209  static DateTime now(void);
210 
219  static void initializeLeapSeconds(std::string const& leapString);
220 
221 private:
222  long long _nsecs;
223 
225  void _assertValid() const {
226  if (!isValid()) {
227  throw LSST_EXCEPT(pex::exceptions::RuntimeError, "DateTime not valid");
228  }
229  }
230 
238  double _getMjd(Timescale scale) const;
239 
247  double _getJd(Timescale scale) const;
248 
256  double _getEpoch(Timescale scale) const;
257 
265  void setNsecsFromMjd(double mjd, Timescale scale);
266 
274  void setNsecsFromJd(double jd, Timescale scale);
275 
283  void setNsecsFromEpoch(double epoch, Timescale scale);
284 
285  friend class boost::serialization::access;
286 
293  template <class Archive>
294  void serialize(Archive ar, int const version) {
295  ar& _nsecs;
296  }
297 };
298 
299 } // namespace base
300 } // namespace daf
301 } // namespace lsst
302 
303 #endif
Class for handling dates/times, including MJD, UTC, and TAI.
Definition: DateTime.h:63
Definition: DateTime.h:53
STL class.
T min(T... args)
#define LSST_EXCEPT(type,...)
bool isValid() const
Is this date valid?
Definition: DateTime.h:201