------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- A D A . C A L E N D A R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
-- --
-- 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 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. --
-- --
-- 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. --
-- --
------------------------------------------------------------------------------
-- This is the Alpha/VMS version
with Ada.Unchecked_Conversion;
with System.Aux_DEC; use System.Aux_DEC;
with System.OS_Primitives; use System.OS_Primitives;
package body Ada.Calendar is
--------------------------
-- Implementation Notes --
--------------------------
-- Variables of type Ada.Calendar.Time have suffix _S or _M to denote
-- units of seconds or milis.
-- Because time is measured in different units and from different origins
-- on various targets, a system independent model is incorporated into
-- Ada.Calendar. The idea behind the design is to encapsulate all target
-- dependent machinery in a single package, thus providing a uniform
-- interface to all existing and any potential children.
-- package Ada.Calendar
-- procedure Split (5 parameters) -------+
-- | Call from local routine
-- private |
-- package Formatting_Operations |
-- procedure Split (11 parameters) <--+
-- end Formatting_Operations |
-- end Ada.Calendar |
-- |
-- package Ada.Calendar.Formatting | Call from child routine
-- procedure Split (9 or 10 parameters) -+
-- end Ada.Calendar.Formatting
-- The behaviour of the interfacing routines is controlled via various
-- flags. All new Ada 2005 types from children of Ada.Calendar are
-- emulated by a similar type. For instance, type Day_Number is replaced
-- by Integer in various routines. One ramification of this model is that
-- the caller site must perform validity checks on returned results.
-- The end result of this model is the lack of target specific files per
-- child of Ada.Calendar (a-calfor, a-calfor-vms, a-calfor-vxwors, etc).
-----------------------
-- Local Subprograms --
-----------------------
procedure Check_Within_Time_Bounds (T : OS_Time);
-- Ensure that a time representation value falls withing the bounds of Ada
-- time. Leap seconds support is taken into account.
procedure Cumulative_Leap_Seconds
(Start_Date : OS_Time;
End_Date : OS_Time;
Elapsed_Leaps : out Natural;
Next_Leap_Sec : out OS_Time);
-- Elapsed_Leaps is the sum of the leap seconds that have occurred on or
-- after Start_Date and before (strictly before) End_Date. Next_Leap_Sec
-- represents the next leap second occurrence on or after End_Date. If
-- there are no leaps seconds after End_Date, End_Of_Time is returned.
-- End_Of_Time can be used as End_Date to count all the leap seconds that
-- have occurred on or after Start_Date.
--
-- Note: Any sub seconds of Start_Date and End_Date are discarded before
-- the calculations are done. For instance: if 113 seconds is a leap
-- second (it isn't) and 113.5 is input as an End_Date, the leap second
-- at 113 will not be counted in Leaps_Between, but it will be returned
-- as Next_Leap_Sec. Thus, if the caller wants to know if the End_Date is
-- a leap second, the comparison should be:
--
-- End_Date >= Next_Leap_Sec;
--
-- After_Last_Leap is designed so that this comparison works without
-- having to first check if Next_Leap_Sec is a valid leap second.
function To_Duration (T : Time) return Duration;
function To_Relative_Time (D : Duration) return Time;
-- It is important to note that duration's fractional part denotes nano
-- seconds while the units of Time are 100 nanoseconds. If a regular
-- Unchecked_Conversion was employed, the resulting values would be off
-- by 100.
--------------------------
-- Leap seconds control --
--------------------------
Flag : Integer;
pragma Import (C, Flag, "__gl_leap_seconds_support");
-- This imported value is used to determine whether the compilation had
-- binder flag "-y" present which enables leap seconds. A value of zero
-- signifies no leap seconds support while a value of one enables the
-- support.
Leap_Support : constant Boolean := Flag = 1;
-- The above flag controls the usage of leap seconds in all Ada.Calendar
-- routines.
Leap_Seconds_Count : constant Natural := 24;
---------------------
-- Local Constants --
---------------------
-- The range of Ada time expressed as milis since the VMS Epoch
Ada_Low : constant OS_Time := (10 * 366 + 32 * 365 + 45) * Milis_In_Day;
Ada_High : constant OS_Time := (131 * 366 + 410 * 365 + 45) * Milis_In_Day;
-- Even though the upper bound of time is 2399-12-31 23:59:59.9999999
-- UTC, it must be increased to include all leap seconds.
Ada_High_And_Leaps : constant OS_Time :=
Ada_High + OS_Time (Leap_Seconds_Count) * Mili;
-- Two constants used in the calculations of elapsed leap seconds.
-- End_Of_Time is later than Ada_High in time zone -28. Start_Of_Time
-- is earlier than Ada_Low in time zone +28.
End_Of_Time : constant OS_Time := Ada_High + OS_Time (3) * Milis_In_Day;
Start_Of_Time : constant OS_Time := Ada_Low - OS_Time (3) * Milis_In_Day;
-- The following table contains the hard time values of all existing leap
-- seconds. The values are produced by the utility program xleaps.adb.
Leap_Second_Times : constant array (1 .. Leap_Seconds_Count) of OS_Time :=
(35855136000000000,
36014112010000000,
36329472020000000,
36644832030000000,
36960192040000000,
37276416050000000,
37591776060000000,
37907136070000000,
38222496080000000,
38695104090000000,
39010464100000000,
39325824110000000,
39957408120000000,
40747104130000000,
41378688140000000,
41694048150000000,
42166656160000000,
42482016170000000,
42797376180000000,
43271712190000000,
43744320200000000,
44218656210000000,
46427904220000000,
47374848230000000);
---------
-- "+" --
---------
function "+" (Left : Time; Right : Duration) return Time is
pragma Unsuppress (Overflow_Check);
begin
return Left + To_Relative_Time (Right);
exception
when Constraint_Error =>
raise Time_Error;
end "+";
function "+" (Left : Duration; Right : Time) return Time is
pragma Unsuppress (Overflow_Check);
begin
return Right + Left;
exception
when Constraint_Error =>
raise Time_Error;
end "+";
---------
-- "-" --
---------
function "-" (Left : Time; Right : Duration) return Time is
pragma Unsuppress (Overflow_Check);
begin
return Left - To_Relative_Time (Right);
exception
when Constraint_Error =>
raise Time_Error;
end "-";
function "-" (Left : Time; Right : Time) return Duration is
pragma Unsuppress (Overflow_Check);
-- The bound of type Duration expressed as time
Dur_High : constant OS_Time :=
OS_Time (To_Relative_Time (Duration'Last));
Dur_Low : constant OS_Time :=
OS_Time (To_Relative_Time (Duration'First));
Res_M : OS_Time;
begin
Res_M := OS_Time (Left) - OS_Time (Right);
-- Due to the extended range of Ada time, "-" is capable of producing
-- results which may exceed the range of Duration. In order to prevent
-- the generation of bogus values by the Unchecked_Conversion, we apply
-- the following check.
if Res_M < Dur_Low
or else Res_M >= Dur_High
then
raise Time_Error;
-- Normal case, result fits
else
return To_Duration (Time (Res_M));
end if;
exception
when Constraint_Error =>
raise Time_Error;
end "-";
---------
-- "<" --
---------
function "<" (Left, Right : Time) return Boolean is
begin
return OS_Time (Left) < OS_Time (Right);
end "<";
----------
-- "<=" --
----------
function "<=" (Left, Right : Time) return Boolean is
begin
return OS_Time (Left) <= OS_Time (Right);
end "<=";
---------
-- ">" --
---------
function ">" (Left, Right : Time) return Boolean is
begin
return OS_Time (Left) > OS_Time (Right);
end ">";
----------
-- ">=" --
----------
function ">=" (Left, Right : Time) return Boolean is
begin
return OS_Time (Left) >= OS_Time (Right);
end ">=";
------------------------------
-- Check_Within_Time_Bounds --
------------------------------
procedure Check_Within_Time_Bounds (T : OS_Time) is
begin
if Leap_Support then
if T < Ada_Low or else T > Ada_High_And_Leaps then
raise Time_Error;
end if;
else
if T < Ada_Low or else T > Ada_High then
raise Time_Error;
end if;
end if;
end Check_Within_Time_Bounds;
-----------
-- Clock --
-----------
function Clock return Time is
Elapsed_Leaps : Natural;
Next_Leap_M : OS_Time;
Res_M : constant OS_Time := OS_Clock;
begin
-- Note that on other targets a soft-link is used to get a different
-- clock depending whether tasking is used or not. On VMS this isn't
-- needed since all clock calls end up using SYS$GETTIM, so call the
-- OS_Primitives version for efficiency.
-- If the target supports leap seconds, determine the number of leap
-- seconds elapsed until this moment.
if Leap_Support then
Cumulative_Leap_Seconds
(Start_Of_Time, Res_M, Elapsed_Leaps, Next_Leap_M);
-- The system clock may fall exactly on a leap second
if Res_M >= Next_Leap_M then
Elapsed_Leaps := Elapsed_Leaps + 1;
end if;
-- The target does not support leap seconds
else
Elapsed_Leaps := 0;
end if;
return Time (Res_M + OS_Time (Elapsed_Leaps) * Mili);
end Clock;
-----------------------------
-- Cumulative_Leap_Seconds --
-----------------------------
procedure Cumulative_Leap_Seconds
(Start_Date : OS_Time;
End_Date : OS_Time;
Elapsed_Leaps : out Natural;
Next_Leap_Sec : out OS_Time)
is
End_Index : Positive;
End_T : OS_Time := End_Date;
Start_Index : Positive;
Start_T : OS_Time := Start_Date;
begin
pragma Assert (Leap_Support and then End_Date >= Start_Date);
Next_Leap_Sec := End_Of_Time;
-- Make sure that the end date does not exceed the upper bound
-- of Ada time.
if End_Date > Ada_High then
End_T := Ada_High;
end if;
-- Remove the sub seconds from both dates
Start_T := Start_T - (Start_T mod Mili);
End_T := End_T - (End_T mod Mili);
-- Some trivial cases:
-- Leap 1 . . . Leap N
-- ---+========+------+############+-------+========+-----
-- Start_T End_T Start_T End_T
if End_T < Leap_Second_Times (1) then
Elapsed_Leaps := 0;
Next_Leap_Sec := Leap_Second_Times (1);
return;
elsif Start_T > Leap_Second_Times (Leap_Seconds_Count) then
Elapsed_Leaps := 0;
Next_Leap_Sec := End_Of_Time;
return;
end if;
-- Perform the calculations only if the start date is within the leap
-- second occurrences table.
if Start_T <= Leap_Second_Times (Leap_Seconds_Count) then
-- 1 2 N - 1 N
-- +----+----+-- . . . --+-------+---+
-- | T1 | T2 | | N - 1 | N |
-- +----+----+-- . . . --+-------+---+
-- ^ ^
-- | Start_Index | End_Index
-- +-------------------+
-- Leaps_Between
-- The idea behind the algorithm is to iterate and find two closest
-- dates which are after Start_T and End_T. Their corresponding
-- index difference denotes the number of leap seconds elapsed.
Start_Index := 1;
loop
exit when Leap_Second_Times (Start_Index) >= Start_T;
Start_Index := Start_Index + 1;
end loop;
End_Index := Start_Index;
loop
exit when End_Index > Leap_Seconds_Count
or else Leap_Second_Times (End_Index) >= End_T;
End_Index := End_Index + 1;
end loop;
if End_Index <= Leap_Seconds_Count then
Next_Leap_Sec := Leap_Second_Times (End_Index);
end if;
Elapsed_Leaps := End_Index - Start_Index;
else
Elapsed_Leaps := 0;
end if;
end Cumulative_Leap_Seconds;
---------
-- Day --
---------
function Day (Date : Time) return Day_Number is
Y : Year_Number;
M : Month_Number;
D : Day_Number;
S : Day_Duration;
pragma Unreferenced (Y, M, S);
begin
Split (Date, Y, M, D, S);
return D;
end Day;
-------------
-- Is_Leap --
-------------
function Is_Leap (Year : Year_Number) return Boolean is
begin
-- Leap centennial years
if Year mod 400 = 0 then
return True;
-- Non-leap centennial years
elsif Year mod 100 = 0 then
return False;
-- Regular years
else
return Year mod 4 = 0;
end if;
end Is_Leap;
-----------
-- Month --
-----------
function Month (Date : Time) return Month_Number is
Y : Year_Number;
M : Month_Number;
D : Day_Number;
S : Day_Duration;
pragma Unreferenced (Y, D, S);
begin
Split (Date, Y, M, D, S);
return M;
end Month;
-------------
-- Seconds --
-------------
function Seconds (Date : Time) return Day_Duration is
Y : Year_Number;
M : Month_Number;
D : Day_Number;
S : Day_Duration;
pragma Unreferenced (Y, M, D);
begin
Split (Date, Y, M, D, S);
return S;
end Seconds;
-----------
-- Split --
-----------
procedure Split
(Date : Time;
Year : out Year_Number;
Month : out Month_Number;
Day : out Day_Number;
Seconds : out Day_Duration)
is
H : Integer;
M : Integer;
Se : Integer;
Ss : Duration;
Le : Boolean;
begin
-- Use UTC as the local time zone on VMS, the status of flag Is_Ada_05
-- is irrelevant in this case.
Formatting_Operations.Split
(Date => Date,
Year => Year,
Month => Month,
Day => Day,
Day_Secs => Seconds,
Hour => H,
Minute => M,
Second => Se,
Sub_Sec => Ss,
Leap_Sec => Le,
Is_Ada_05 => False,
Time_Zone => 0);
-- Validity checks
if not Year'Valid
or else not Month'Valid
or else not Day'Valid
or else not Seconds'Valid
then
raise Time_Error;
end if;
end Split;
-------------
-- Time_Of --
-------------
function Time_Of
(Year : Year_Number;
Month : Month_Number;
Day : Day_Number;
Seconds : Day_Duration := 0.0) return Time
is
-- The values in the following constants are irrelevant, they are just
-- placeholders; the choice of constructing a Day_Duration value is
-- controlled by the Use_Day_Secs flag.
H : constant Integer := 1;
M : constant Integer := 1;
Se : constant Integer := 1;
Ss : constant Duration := 0.1;
begin
if not Year'Valid
or else not Month'Valid
or else not Day'Valid
or else not Seconds'Valid
then
raise Time_Error;
end if;
-- Use UTC as the local time zone on VMS, the status of flag Is_Ada_05
-- is irrelevant in this case.
return
Formatting_Operations.Time_Of
(Year => Year,
Month => Month,
Day => Day,
Day_Secs => Seconds,
Hour => H,
Minute => M,
Second => Se,
Sub_Sec => Ss,
Leap_Sec => False,
Use_Day_Secs => True,
Is_Ada_05 => False,
Time_Zone => 0);
end Time_Of;
-----------------
-- To_Duration --
-----------------
function To_Duration (T : Time) return Duration is
function Time_To_Duration is
new Ada.Unchecked_Conversion (Time, Duration);
begin
return Time_To_Duration (T * 100);
end To_Duration;
----------------------
-- To_Relative_Time --
----------------------
function To_Relative_Time (D : Duration) return Time is
function Duration_To_Time is
new Ada.Unchecked_Conversion (Duration, Time);
begin
return Duration_To_Time (D / 100.0);
end To_Relative_Time;
----------
-- Year --
----------
function Year (Date : Time) return Year_Number is
Y : Year_Number;
M : Month_Number;
D : Day_Number;
S : Day_Duration;
pragma Unreferenced (M, D, S);
begin
Split (Date, Y, M, D, S);
return Y;
end Year;
-- The following packages assume that Time is a Long_Integer, the units
-- are 100 nanoseconds and the starting point in the VMS Epoch.
---------------------------
-- Arithmetic_Operations --
---------------------------
package body Arithmetic_Operations is
---------
-- Add --
---------
function Add (Date : Time; Days : Long_Integer) return Time is
pragma Unsuppress (Overflow_Check);
Date_M : constant OS_Time := OS_Time (Date);
begin
return Time (Date_M + OS_Time (Days) * Milis_In_Day);
exception
when Constraint_Error =>
raise Time_Error;
end Add;
----------------
-- Difference --
----------------
procedure Difference
(Left : Time;
Right : Time;
Days : out Long_Integer;
Seconds : out Duration;
Leap_Seconds : out Integer)
is
Diff_M : OS_Time;
Diff_S : OS_Time;
Earlier : OS_Time;
Elapsed_Leaps : Natural;
Later : OS_Time;
Negate : Boolean := False;
Next_Leap : OS_Time;
Sub_Seconds : Duration;
begin
-- This classification is necessary in order to avoid a Time_Error
-- being raised by the arithmetic operators in Ada.Calendar.
if Left >= Right then
Later := OS_Time (Left);
Earlier := OS_Time (Right);
else
Later := OS_Time (Right);
Earlier := OS_Time (Left);
Negate := True;
end if;
-- If the target supports leap seconds, process them
if Leap_Support then
Cumulative_Leap_Seconds
(Earlier, Later, Elapsed_Leaps, Next_Leap);
if Later >= Next_Leap then
Elapsed_Leaps := Elapsed_Leaps + 1;
end if;
-- The target does not support leap seconds
else
Elapsed_Leaps := 0;
end if;
Diff_M := Later - Earlier - OS_Time (Elapsed_Leaps) * Mili;
-- Sub second processing
Sub_Seconds := Duration (Diff_M mod Mili) / Mili_F;
-- Convert to seconds. Note that his action eliminates the sub
-- seconds automatically.
Diff_S := Diff_M / Mili;
Days := Long_Integer (Diff_S / Secs_In_Day);
Seconds := Duration (Diff_S mod Secs_In_Day) + Sub_Seconds;
Leap_Seconds := Integer (Elapsed_Leaps);
if Negate then
Days := -Days;
Seconds := -Seconds;
if Leap_Seconds /= 0 then
Leap_Seconds := -Leap_Seconds;
end if;
end if;
end Difference;
--------------
-- Subtract --
--------------
function Subtract (Date : Time; Days : Long_Integer) return Time is
pragma Unsuppress (Overflow_Check);
Date_M : constant OS_Time := OS_Time (Date);
begin
return Time (Date_M - OS_Time (Days) * Milis_In_Day);
exception
when Constraint_Error =>
raise Time_Error;
end Subtract;
end Arithmetic_Operations;
---------------------------
-- Conversion_Operations --
---------------------------
package body Conversion_Operations is
Epoch_Offset : constant OS_Time := 35067168000000000;
-- The difference between 1970-1-1 UTC and 1858-11-17 UTC expressed in
-- 100 nanoseconds.
-----------------
-- To_Ada_Time --
-----------------
function To_Ada_Time (Unix_Time : Long_Integer) return Time is
pragma Unsuppress (Overflow_Check);
Unix_Rep : constant OS_Time := OS_Time (Unix_Time) * Mili;
begin
return Time (Unix_Rep + Epoch_Offset);
exception
when Constraint_Error =>
raise Time_Error;
end To_Ada_Time;
-----------------
-- To_Ada_Time --
-----------------
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
is
pragma Unsuppress (Overflow_Check);
Year_Shift : constant Integer := 1900;
Month_Shift : constant Integer := 1;
Year : Year_Number;
Month : Month_Number;
Day : Day_Number;
Second : Integer;
Leap : Boolean;
Result : OS_Time;
begin
-- Input processing
Year := Year_Number (Year_Shift + tm_year);
Month := Month_Number (Month_Shift + tm_mon);
Day := Day_Number (tm_day);
-- Step 1: Validity checks of input values
if not Year'Valid
or else not Month'Valid
or else not Day'Valid
or else tm_hour not in 0 .. 24
or else tm_min not in 0 .. 59
or else tm_sec not in 0 .. 60
or else tm_isdst not in -1 .. 1
then
raise Time_Error;
end if;
-- Step 2: Potential leap second
if tm_sec = 60 then
Leap := True;
Second := 59;
else
Leap := False;
Second := tm_sec;
end if;
-- Step 3: Calculate the time value
Result :=
OS_Time
(Formatting_Operations.Time_Of
(Year => Year,
Month => Month,
Day => Day,
Day_Secs => 0.0, -- Time is given in h:m:s
Hour => tm_hour,
Minute => tm_min,
Second => Second,
Sub_Sec => 0.0, -- No precise sub second given
Leap_Sec => Leap,
Use_Day_Secs => False, -- Time is given in h:m:s
Is_Ada_05 => True, -- Force usage of explicit time zone
Time_Zone => 0)); -- Place the value in UTC
-- Step 4: Daylight Savings Time
if tm_isdst = 1 then
Result := Result + OS_Time (3_600) * Mili;
end if;
return Time (Result);
exception
when Constraint_Error =>
raise Time_Error;
end To_Ada_Time;
-----------------
-- To_Duration --
-----------------
function To_Duration
(tv_sec : Long_Integer;
tv_nsec : Long_Integer) return Duration
is
pragma Unsuppress (Overflow_Check);
begin
return Duration (tv_sec) + Duration (tv_nsec) / Mili_F;
end To_Duration;
------------------------
-- To_Struct_Timespec --
------------------------
procedure To_Struct_Timespec
(D : Duration;
tv_sec : out Long_Integer;
tv_nsec : out Long_Integer)
is
pragma Unsuppress (Overflow_Check);
Secs : Duration;
Nano_Secs : Duration;
begin
-- Seconds extraction, avoid potential rounding errors
Secs := D - 0.5;
tv_sec := Long_Integer (Secs);
-- 100 Nanoseconds extraction
Nano_Secs := D - Duration (tv_sec);
tv_nsec := Long_Integer (Nano_Secs * Mili);
end To_Struct_Timespec;
------------------
-- To_Struct_Tm --
------------------
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)
is
pragma Unsuppress (Overflow_Check);
Year : Year_Number;
Month : Month_Number;
Second : Integer;
Day_Secs : Day_Duration;
Sub_Sec : Duration;
Leap_Sec : Boolean;
begin
-- Step 1: Split the input time
Formatting_Operations.Split
(T, Year, Month, tm_day, Day_Secs,
tm_hour, tm_min, Second, Sub_Sec, Leap_Sec, True, 0);
-- Step 2: Correct the year and month
tm_year := Year - 1900;
tm_mon := Month - 1;
-- Step 3: Handle leap second occurrences
tm_sec := (if Leap_Sec then 60 else Second);
end To_Struct_Tm;
------------------
-- To_Unix_Time --
------------------
function To_Unix_Time (Ada_Time : Time) return Long_Integer is
pragma Unsuppress (Overflow_Check);
Ada_OS_Time : constant OS_Time := OS_Time (Ada_Time);
begin
return Long_Integer ((Ada_OS_Time - Epoch_Offset) / Mili);
exception
when Constraint_Error =>
raise Time_Error;
end To_Unix_Time;
end Conversion_Operations;
---------------------------
-- Formatting_Operations --
---------------------------
package body Formatting_Operations is
-----------------
-- Day_Of_Week --
-----------------
function Day_Of_Week (Date : Time) return Integer is
Y : Year_Number;
M : Month_Number;
D : Day_Number;
S : Day_Duration;
Day_Count : Long_Integer;
Midday_Date_S : Time;
begin
Split (Date, Y, M, D, S);
-- Build a time value in the middle of the same day and convert the
-- time value to seconds.
Midday_Date_S := Time_Of (Y, M, D, 43_200.0) / Mili;
-- Count the number of days since the start of VMS time. 1858-11-17
-- was a Wednesday.
Day_Count := Long_Integer (Midday_Date_S / Secs_In_Day) + 2;
return Integer (Day_Count mod 7);
end Day_Of_Week;
-----------
-- Split --
-----------
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;
Is_Ada_05 : Boolean;
Time_Zone : Long_Integer)
is
-- The flag Is_Ada_05 is present for interfacing purposes
pragma Unreferenced (Is_Ada_05);
procedure Numtim
(Status : out Unsigned_Longword;
Timbuf : out Unsigned_Word_Array;
Timadr : Time);
pragma Interface (External, Numtim);
pragma Import_Valued_Procedure
(Numtim, "SYS$NUMTIM",
(Unsigned_Longword, Unsigned_Word_Array, Time),
(Value, Reference, Reference));
Status : Unsigned_Longword;
Timbuf : Unsigned_Word_Array (1 .. 7);
Ada_Min_Year : constant := 1901;
Ada_Max_Year : constant := 2399;
Date_M : OS_Time;
Elapsed_Leaps : Natural;
Next_Leap_M : OS_Time;
begin
Date_M := OS_Time (Date);
-- Step 1: Leap seconds processing
if Leap_Support then
Cumulative_Leap_Seconds
(Start_Of_Time, Date_M, Elapsed_Leaps, Next_Leap_M);
Leap_Sec := Date_M >= Next_Leap_M;
if Leap_Sec then
Elapsed_Leaps := Elapsed_Leaps + 1;
end if;
-- The target does not support leap seconds
else
Elapsed_Leaps := 0;
Leap_Sec := False;
end if;
Date_M := Date_M - OS_Time (Elapsed_Leaps) * Mili;
-- Step 2: Time zone processing
if Time_Zone /= 0 then
Date_M := Date_M + OS_Time (Time_Zone) * 60 * Mili;
end if;
-- After the leap seconds and time zone have been accounted for,
-- the date should be within the bounds of Ada time.
if Date_M < Ada_Low
or else Date_M > Ada_High
then
raise Time_Error;
end if;
-- Step 3: Sub second processing
Sub_Sec := Duration (Date_M mod Mili) / Mili_F;
-- Drop the sub seconds
Date_M := Date_M - (Date_M mod Mili);
-- Step 4: VMS system call
Numtim (Status, Timbuf, Time (Date_M));
if Status mod 2 /= 1
or else Timbuf (1) not in Ada_Min_Year .. Ada_Max_Year
then
raise Time_Error;
end if;
-- Step 5: Time components processing
Year := Year_Number (Timbuf (1));
Month := Month_Number (Timbuf (2));
Day := Day_Number (Timbuf (3));
Hour := Integer (Timbuf (4));
Minute := Integer (Timbuf (5));
Second := Integer (Timbuf (6));
Day_Secs := Day_Duration (Hour * 3_600) +
Day_Duration (Minute * 60) +
Day_Duration (Second) +
Sub_Sec;
end Split;
-------------
-- Time_Of --
-------------
function Time_Of
(Year : Year_Number;
Month : Month_Number;
Day : Day_Number;
Day_Secs : Day_Duration;
Hour : Integer;
Minute : Integer;
Second : Integer;
Sub_Sec : Duration;
Leap_Sec : Boolean := False;
Use_Day_Secs : Boolean := False;
Is_Ada_05 : Boolean := False;
Time_Zone : Long_Integer := 0) return Time
is
procedure Cvt_Vectim
(Status : out Unsigned_Longword;
Input_Time : Unsigned_Word_Array;
Resultant_Time : out Time);
pragma Interface (External, Cvt_Vectim);
pragma Import_Valued_Procedure
(Cvt_Vectim, "LIB$CVT_VECTIM",
(Unsigned_Longword, Unsigned_Word_Array, Time),
(Value, Reference, Reference));
Status : Unsigned_Longword;
Timbuf : Unsigned_Word_Array (1 .. 7);
Y : Year_Number := Year;
Mo : Month_Number := Month;
D : Day_Number := Day;
H : Integer := Hour;
Mi : Integer := Minute;
Se : Integer := Second;
Su : Duration := Sub_Sec;
Elapsed_Leaps : Natural;
Int_Day_Secs : Integer;
Next_Leap_M : OS_Time;
Res : Time;
Res_M : OS_Time;
Rounded_Res_M : OS_Time;
begin
-- No validity checks are performed on the input values since it is
-- assumed that the called has already performed them.
-- Step 1: Hour, minute, second and sub second processing
if Use_Day_Secs then
-- A day seconds value of 86_400 designates a new day
if Day_Secs = 86_400.0 then
declare
Adj_Year : Year_Number := Year;
Adj_Month : Month_Number := Month;
Adj_Day : Day_Number := Day;
begin
if Day < Days_In_Month (Month)
or else (Month = 2
and then Is_Leap (Year))
then
Adj_Day := Day + 1;
-- The day adjustment moves the date to a new month
else
Adj_Day := 1;
if Month < 12 then
Adj_Month := Month + 1;
-- The month adjustment moves the date to a new year
else
Adj_Month := 1;
Adj_Year := Year + 1;
end if;
end if;
Y := Adj_Year;
Mo := Adj_Month;
D := Adj_Day;
H := 0;
Mi := 0;
Se := 0;
Su := 0.0;
end;
-- Normal case (not exactly one day)
else
-- Sub second extraction
Int_Day_Secs :=
(if Day_Secs > 0.0
then Integer (Day_Secs - 0.5)
else Integer (Day_Secs));
H := Int_Day_Secs / 3_600;
Mi := (Int_Day_Secs / 60) mod 60;
Se := Int_Day_Secs mod 60;
Su := Day_Secs - Duration (Int_Day_Secs);
end if;
end if;
-- Step 2: System call to VMS
Timbuf (1) := Unsigned_Word (Y);
Timbuf (2) := Unsigned_Word (Mo);
Timbuf (3) := Unsigned_Word (D);
Timbuf (4) := Unsigned_Word (H);
Timbuf (5) := Unsigned_Word (Mi);
Timbuf (6) := Unsigned_Word (Se);
Timbuf (7) := 0;
Cvt_Vectim (Status, Timbuf, Res);
if Status mod 2 /= 1 then
raise Time_Error;
end if;
-- Step 3: Sub second adjustment
Res_M := OS_Time (Res) + OS_Time (Su * Mili_F);
-- Step 4: Bounds check
Check_Within_Time_Bounds (Res_M);
-- Step 5: Time zone processing
if Time_Zone /= 0 then
Res_M := Res_M - OS_Time (Time_Zone) * 60 * Mili;
end if;
-- Step 6: Leap seconds processing
if Leap_Support then
Cumulative_Leap_Seconds
(Start_Of_Time, Res_M, Elapsed_Leaps, Next_Leap_M);
Res_M := Res_M + OS_Time (Elapsed_Leaps) * Mili;
-- An Ada 2005 caller requesting an explicit leap second or an
-- Ada 95 caller accounting for an invisible leap second.
if Leap_Sec
or else Res_M >= Next_Leap_M
then
Res_M := Res_M + OS_Time (1) * Mili;
end if;
-- Leap second validity check
Rounded_Res_M := Res_M - (Res_M mod Mili);
if Is_Ada_05
and then Leap_Sec
and then Rounded_Res_M /= Next_Leap_M
then
raise Time_Error;
end if;
end if;
return Time (Res_M);
end Time_Of;
end Formatting_Operations;
---------------------------
-- Time_Zones_Operations --
---------------------------
package body Time_Zones_Operations is
---------------------
-- UTC_Time_Offset --
---------------------
function UTC_Time_Offset (Date : Time) return Long_Integer is
-- Formal parameter Date is here for interfacing, but is never
-- actually used.
pragma Unreferenced (Date);
function get_gmtoff return Long_Integer;
pragma Import (C, get_gmtoff, "get_gmtoff");
begin
-- VMS is not capable of determining the time zone in some past or
-- future point in time denoted by Date, thus the current time zone
-- is retrieved.
return get_gmtoff;
end UTC_Time_Offset;
end Time_Zones_Operations;
end Ada.Calendar;