-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
-- --
-- This specification is derived from the Ada Reference Manual for use with --
-- GNAT. The copyright notice above, and the license provisions that follow --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
--- ware Foundation; either version 2, or (at your option) any later ver- --
+-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
--- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING. If not, write --
--- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
--- Boston, MA 02110-1301, USA. --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
--- As a special exception, if other files instantiate generics from this --
--- unit, or you link this unit with other files to produce an executable, --
--- this unit does not by itself cause the resulting executable to be --
--- covered by the GNU General Public License. This exception does not --
--- however invalidate any other reasons why the executable file might be --
--- covered by the GNU Public License. --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception, --
+-- version 3.1, as published by the Free Software Foundation. --
+-- --
+-- You should have received a copy of the GNU General Public License and --
+-- a copy of the GCC Runtime Library Exception along with this program; --
+-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
+-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
function Clock return Time;
-- The returned time value is the number of nanoseconds since the start
- -- of Ada time (1901-1-1 0.0 GMT).
+ -- of Ada time (1901-01-01 00:00:00.0 UTC). If leap seconds are enabled,
+ -- the result will contain all elapsed leap seconds since the start of
+ -- Ada time until now.
function Year (Date : Time) return Year_Number;
function Month (Date : Time) return Month_Number;
Seconds : out Day_Duration);
-- Break down a time value into its date components set in the current
-- time zone. If Split is called on a time value created using Ada 2005
- -- Time_Of in some arbitrary time zone, the input value always will be
- -- interpreted as some point in time relative to the local time zone.
+ -- Time_Of in some arbitrary time zone, the input value will always be
+ -- interpreted as relative to the local time zone.
function Time_Of
(Year : Year_Number;
function "-" (Left : Time; Right : Duration) return Time;
function "-" (Left : Time; Right : Time) return Duration;
-- The first three functions will raise Time_Error if the resulting time
- -- value is less than the start of Ada time in GMT or greater than the
- -- end of Ada time in GMT. The last function will raise Time_Error if the
+ -- value is less than the start of Ada time in UTC or greater than the
+ -- end of Ada time in UTC. The last function will raise Time_Error if the
-- resulting difference cannot fit into a duration value.
function "<" (Left, Right : Time) return Boolean;
-- Implementation of Time --
----------------------------
- -- Time is represented as an unsigned 64 bit integer count of nanoseconds
- -- since the start of Ada time (1901-1-1 0.0 GMT). Time values produced
- -- by Time_Of are internaly normalized to GMT regardless of their local
- -- time zone. This representation ensures correct handling of leap seconds
- -- as well as performing arithmetic. In Ada 95, Split will treat a time
- -- value as being in the local time zone and break it down accordingly.
- -- In Ada 2005, Split will treat a time value as being in the designated
- -- time zone by the corresponding formal parameter or in GMT by default.
- -- The size of the type is large enough to cover the Ada 2005 range of
- -- time (1901-1-1 0.0 GMT - 2399-12-31-86_399.999999999 GMT).
+ -- Time is represented as a signed 64 bit integer count of nanoseconds
+ -- since the start of Ada time (1901-01-01 00:00:00.0 UTC). Time values
+ -- produced by Time_Of are internally normalized to UTC regardless of their
+ -- local time zone. This representation ensures correct handling of leap
+ -- seconds as well as performing arithmetic. In Ada 95, Split and Time_Of
+ -- will treat a time value as being in the local time zone, in Ada 2005,
+ -- Split and Time_Of will treat a time value as being in the designated
+ -- time zone by the formal parameter or in UTC by default. The size of the
+ -- type is large enough to cover the Ada 2005 range of time (1901-01-01
+ -- 00:00:00.0 UTC - 2399-12-31-23:59:59.999999999 UTC).
------------------
-- Leap seconds --
-- Due to Earth's slowdown, the astronomical time is not as precise as the
-- International Atomic Time. To compensate for this inaccuracy, a single
-- leap second is added after the last day of June or December. The count
- -- of seconds during those occurences becomes:
+ -- of seconds during those occurrences becomes:
- -- ... 58, 59, leap second 60, 1, 2 ...
+ -- ... 58, 59, leap second 60, 0, 1, 2 ...
-- Unlike leap days, leap seconds occur simultaneously around the world.
- -- In other words, if a leap second occurs at 23:59:60 GMT, it also occurs
- -- on 18:59:60 -5 or 2:59:60 +2 on the next day.
+ -- In other words, if a leap second occurs at 23:59:60 UTC, it also occurs
+ -- on 18:59:60 -5 the same day or 2:59:60 +2 on the next day.
+
-- Leap seconds do not follow a formula. The International Earth Rotation
-- and Reference System Service decides when to add one. Leap seconds are
-- included in the representation of time in Ada 95 mode. As a result,
- -- the following two time values will conceptually differ by two seconds:
+ -- the following two time values will differ by two seconds:
- -- Time_Of (1972, 7, 1, 0.0) - Time_Of (1972, 6, 30, 86_399.0) = 2 secs
+ -- 1972-06-30 23:59:59.0
+ -- 1972-07-01 00:00:00.0
- -- When a new leap second is added, the following steps must be carried
- -- out:
+ -- When a new leap second is introduced, the following steps must be
+ -- carried out:
- -- 1) Increment Leap_Seconds_Count by one
- -- 2) Add an entry to the end of table Leap_Second_Dates
+ -- 1) Increment Leap_Seconds_Count in a-calend.adb by one
+ -- 2) Increment LS_Count in xleaps.adb by one
+ -- 3) Add the new date to the aggregate of array LS_Dates in
+ -- xleaps.adb
+ -- 4) Compile and execute xleaps
+ -- 5) Replace the values of Leap_Second_Times in a-calend.adb with the
+ -- aggregate generated by xleaps
-- The algorithms that build the actual leap second values and discover
- -- how many leap seconds have occured between two dates do not need any
+ -- how many leap seconds have occurred between two dates do not need any
-- modification.
------------------------------
- -- Non-leap centenial years --
+ -- Non-leap centennial years --
------------------------------
- -- Over the range of Ada time, centenial years 2100, 2200 and 2300 are
+ -- Over the range of Ada time, centennial years 2100, 2200 and 2300 are
-- non-leap. As a consequence, seven non-leap years occur over the period
- -- of year - 4 to year + 4. Internaly, routines Split and Time_Of add or
+ -- of year - 4 to year + 4. Internally, routines Split and Time_Of add or
-- subtract a "fake" February 29 to facilitate the arithmetic involved.
- -- This small "cheat" remains hidden and the following calculations do
- -- produce the correct difference.
- -- Time_Of (2100, 3, 1, 0.0) - Time_Of (2100, 2, 28, 0.0) = 1 day
- -- Time_Of (2101, 1, 1, 0.0) - Time_Of (2100, 12, 31, 0.0) = 1 day
+ -- The underlying type of Time has been chosen to be a 64 bit signed
+ -- integer number since it allows for easier processing of sub seconds
+ -- and arithmetic.
- type Time_Rep is mod 2 ** 64;
+ type Time_Rep is range -2 ** 63 .. +2 ** 63 - 1;
type Time is new Time_Rep;
- -- Due to boundary time values and time zones, two days of buffer space
- -- are set aside at both end points of Ada time:
-
- -- Abs zero Hard low Soft low Soft high Hard high
- -- +---------+============+#################+============+----------->
- -- Buffer 1 Real Ada time Buffer 2
-
- -- A time value in a any time zone may not excede the hard bounds of Ada
- -- time, while a value in GMT may not go over the soft bounds.
-
- Buffer_D : constant Duration := 2.0 * Secs_In_Day;
- Buffer_N : constant Time := 2 * Nanos_In_Day;
-
- -- Lower and upper bound of Ada time shifted by two days from the absolute
- -- zero. Note that the upper bound includes the non-leap centenial years.
-
- Ada_Low : constant Time := Buffer_N;
- Ada_High : constant Time := (121 * 366 + 378 * 365) * Nanos_In_Day +
- Buffer_N;
-
- -- Both of these hard bounds are 28 hours before and after their regular
- -- counterpart. The value of 28 is taken from Ada.Calendar.Time_Zones.
-
- Hard_Ada_Low : constant Time := Ada_Low - 100_800 * Nano;
- Hard_Ada_High : constant Time := Ada_High + 100_800 * Nano;
-
Days_In_Month : constant array (Month_Number) of Day_Number :=
(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
-- Determine whether a given year is leap
-- The following packages provide a target independent interface to the
- -- children of Calendar - Arithmetic, Delays, Formatting and Time_Zones.
+ -- children of Calendar - Arithmetic, Conversions, Delays, Formatting and
+ -- Time_Zones.
+
+ ---------------------------
+ -- Arithmetic_Operations --
+ ---------------------------
package Arithmetic_Operations is
+
function Add (Date : Time; Days : Long_Integer) return Time;
- -- Add X number of days to a time value
+ -- Add a certain number of days to a time value
procedure Difference
(Left : Time;
-- values are positive, negative otherwise.
function Subtract (Date : Time; Days : Long_Integer) return Time;
- -- Subtract X number of days from a time value
+ -- Subtract a certain number of days from a time value
+
end Arithmetic_Operations;
- package Delays_Operations is
- function To_Duration (Ada_Time : Time) return Duration;
+ ---------------------------
+ -- Conversion_Operations --
+ ---------------------------
+
+ package Conversion_Operations is
+
+ function To_Ada_Time (Unix_Time : Long_Integer) return Time;
+ -- Unix to Ada Epoch conversion
+
+ function To_Ada_Time
+ (tm_year : Integer;
+ tm_mon : Integer;
+ tm_day : Integer;
+ tm_hour : Integer;
+ tm_min : Integer;
+ tm_sec : Integer;
+ tm_isdst : Integer) return Time;
+ -- Struct tm to Ada Epoch conversion
+
+ function To_Duration
+ (tv_sec : Long_Integer;
+ tv_nsec : Long_Integer) return Duration;
+ -- Struct timespec to Duration conversion
+
+ procedure To_Struct_Timespec
+ (D : Duration;
+ tv_sec : out Long_Integer;
+ tv_nsec : out Long_Integer);
+ -- Duration to struct timespec conversion
+
+ procedure To_Struct_Tm
+ (T : Time;
+ tm_year : out Integer;
+ tm_mon : out Integer;
+ tm_day : out Integer;
+ tm_hour : out Integer;
+ tm_min : out Integer;
+ tm_sec : out Integer);
+ -- Time to struct tm conversion
+
+ function To_Unix_Time (Ada_Time : Time) return Long_Integer;
+ -- Ada to Unix Epoch conversion
+
+ end Conversion_Operations;
+
+ ----------------------
+ -- Delay_Operations --
+ ----------------------
+
+ package Delay_Operations is
+
+ function To_Duration (Date : Time) return Duration;
-- Given a time value in nanoseconds since 1901, convert it into a
-- duration value giving the number of nanoseconds since the Unix Epoch.
- end Delays_Operations;
+
+ end Delay_Operations;
+
+ ---------------------------
+ -- Formatting_Operations --
+ ---------------------------
package Formatting_Operations is
+
function Day_Of_Week (Date : Time) return Integer;
-- Determine which day of week Date falls on. The returned values are
-- within the range of 0 .. 6 (Monday .. Sunday).
procedure Split
- (Date : Time;
- Year : out Year_Number;
- Month : out Month_Number;
- Day : out Day_Number;
- Day_Secs : out Day_Duration;
- Hour : out Integer;
- Minute : out Integer;
- Second : out Integer;
- Sub_Sec : out Duration;
- Leap_Sec : out Boolean;
- Time_Zone : Long_Integer);
- -- Split a time value into its components
+ (Date : Time;
+ Year : out Year_Number;
+ Month : out Month_Number;
+ Day : out Day_Number;
+ Day_Secs : out Day_Duration;
+ Hour : out Integer;
+ Minute : out Integer;
+ Second : out Integer;
+ Sub_Sec : out Duration;
+ Leap_Sec : out Boolean;
+ Is_Ada_05 : Boolean;
+ Time_Zone : Long_Integer);
+ -- Split a time value into its components. Set Is_Ada_05 to use the
+ -- local time zone (the value in Time_Zone is ignored) when splitting
+ -- a time value.
function Time_Of
(Year : Year_Number;
Minute : Integer;
Second : Integer;
Sub_Sec : Duration;
- Leap_Sec : Boolean;
- Leap_Checks : Boolean;
- Use_Day_Secs : Boolean;
- Time_Zone : Long_Integer) return Time;
+ Leap_Sec : Boolean := False;
+ Use_Day_Secs : Boolean := False;
+ Is_Ada_05 : Boolean := False;
+ Time_Zone : Long_Integer := 0) return Time;
-- Given all the components of a date, return the corresponding time
-- value. Set Use_Day_Secs to use the value in Day_Secs, otherwise the
-- day duration will be calculated from Hour, Minute, Second and Sub_
- -- Sec. Set flag Leap_Checks to verify the validity of a leap second.
+ -- Sec. Set Is_Ada_05 to use the local time zone (the value in formal
+ -- Time_Zone is ignored) when building a time value and to verify the
+ -- validity of a requested leap second.
end Formatting_Operations;
+ ---------------------------
+ -- Time_Zones_Operations --
+ ---------------------------
+
package Time_Zones_Operations is
+
function UTC_Time_Offset (Date : Time) return Long_Integer;
- -- Return the offset in seconds from GMT
+ -- Return the offset in seconds from UTC
+
end Time_Zones_Operations;
end Ada.Calendar;
OSDN Git Service
