1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--              A D A . C A L E N D A R . C O N V E R S I O N S             --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--         Copyright (C) 2008-2009  Free Software Foundation, Inc.          --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  This package provides various routines for conversion between Ada and Unix
33--  time models - Time, Duration, struct tm and struct timespec.
34
35with Interfaces.C;
36
37package Ada.Calendar.Conversions is
38
39   function To_Ada_Time (Unix_Time : Interfaces.C.long) return Time;
40   --  Convert a time value represented as number of seconds since the Unix
41   --  Epoch to a time value relative to an Ada implementation-defined Epoch.
42   --  The units of the result are 100 nanoseconds on VMS and nanoseconds on
43   --  all other targets. Raises Time_Error if the result cannot fit into a
44   --  Time value.
45
46   function To_Ada_Time
47     (tm_year  : Interfaces.C.int;
48      tm_mon   : Interfaces.C.int;
49      tm_day   : Interfaces.C.int;
50      tm_hour  : Interfaces.C.int;
51      tm_min   : Interfaces.C.int;
52      tm_sec   : Interfaces.C.int;
53      tm_isdst : Interfaces.C.int) return Time;
54   --  Convert a time value expressed in Unix-like fields of struct tm into
55   --  a Time value relative to the Ada Epoch. The ranges of the formals are
56   --  as follows:
57
58   --     tm_year   --  years since 1900
59   --     tm_mon    --  months since January [0 .. 11]
60   --     tm_day    --  day of the month [1 .. 31]
61   --     tm_hour   --  hours since midnight [0 .. 24]
62   --     tm_min    --  minutes after the hour [0 .. 59]
63   --     tm_sec    --  seconds after the minute [0 .. 60]
64   --     tm_isdst  --  Daylight Savings Time flag [-1 .. 1]
65
66   --  The returned value is in UTC and may or may not contain leap seconds
67   --  depending on whether binder flag "-y" was used. Raises Time_Error if
68   --  the input values are out of the defined ranges or if tm_sec equals 60
69   --  and the instance in time is not a leap second occurrence.
70
71   function To_Duration
72     (tv_sec  : Interfaces.C.long;
73      tv_nsec : Interfaces.C.long) return Duration;
74   --  Convert an elapsed time value expressed in Unix-like fields of struct
75   --  timespec into a Duration value. The expected ranges are:
76
77   --     tv_sec   -  seconds
78   --     tv_nsec  -  nanoseconds
79
80   procedure To_Struct_Timespec
81     (D       : Duration;
82      tv_sec  : out Interfaces.C.long;
83      tv_nsec : out Interfaces.C.long);
84   --  Convert a Duration value into the constituents of struct timespec.
85   --  Formal tv_sec denotes seconds and tv_nsecs denotes nanoseconds.
86
87   procedure To_Struct_Tm
88     (T       : Time;
89      tm_year : out Interfaces.C.int;
90      tm_mon  : out Interfaces.C.int;
91      tm_day  : out Interfaces.C.int;
92      tm_hour : out Interfaces.C.int;
93      tm_min  : out Interfaces.C.int;
94      tm_sec  : out Interfaces.C.int);
95   --  Convert a Time value set in the Ada Epoch into the constituents of
96   --  struct tm. The ranges of the out formals are as follows:
97
98   --     tm_year   --  years since 1900
99   --     tm_mon    --  months since January [0 .. 11]
100   --     tm_day    --  day of the month [1 .. 31]
101   --     tm_hour   --  hours since midnight [0 .. 24]
102   --     tm_min    --  minutes after the hour [0 .. 59]
103   --     tm_sec    --  seconds after the minute [0 .. 60]
104   --     tm_isdst  --  Daylight Savings Time flag [-1 .. 1]
105
106   --  The input date is considered to be in UTC
107
108   function To_Unix_Time (Ada_Time : Time) return Interfaces.C.long;
109   --  Convert a time value represented as number of time units since the Ada
110   --  implementation-defined Epoch to a value relative to the Unix Epoch. The
111   --  units of the result are seconds. Raises Time_Error if the result cannot
112   --  fit into a Time value.
113
114end Ada.Calendar.Conversions;
115