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   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
  35 with Interfaces.C;
  36
  37 package 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
 114 end Ada.Calendar.Conversions;