------------------------------------------------------------------------------
--                                                                          --
--                            GLADE COMPONENTS                              --
--                                                                          --
--     S Y S T E M . G A R L I C . P R I O R I T I E S . M A P P I N G      --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--         Copyright (C) 1996-2020 Free Software Foundation, Inc.           --
--                                                                          --
-- GARLIC 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- --
-- sion.  GARLIC is distributed  in the hope that  it will be  useful,  but --
-- WITHOUT ANY WARRANTY;  without even the implied warranty of MERCHANTABI- --
-- LITY 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 GARLIC;  see file COPYING.  If  --
-- not, write to the Free Software Foundation, 59 Temple Place - Suite 330, --
-- Boston, MA 02111-1307, USA.                                              --
--                                                                          --
-- 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.                                      --
--                                                                          --
------------------------------------------------------------------------------

package body System.Garlic.Priorities.Mapping is

   Global_Priority_Range : constant Natural
     := Natural (Global_Priority'Last - Global_Priority'First + 1);

   Native_Priority_Range : constant Natural
     := Natural (Priority'Last - Priority'First + 1);

   ------------------------
   -- To_Global_Priority --
   ------------------------

   function To_Global_Priority
     (A_Priority : System.Priority)
     return Global_Priority
   is
      Offset : Natural := Natural (A_Priority - Priority'First);

   begin
      Offset := Offset * Global_Priority_Range;
      Offset := Offset / Native_Priority_Range;

      return Global_Priority'First + Global_Priority (Offset);
   end To_Global_Priority;

   ------------------------
   -- To_Native_Priority --
   ------------------------

   function To_Native_Priority
     (A_Priority : Global_Priority)
     return System.Priority
   is
      Offset : Natural := Natural (A_Priority - Global_Priority'First);

   begin
      Offset := Offset * Native_Priority_Range;
      Offset := Offset / Global_Priority_Range;

      return Priority'First + Priority (Offset);
   end To_Native_Priority;

end System.Garlic.Priorities.Mapping;
