------------------------------------------------------------------------------
--                                                                          --
--                           OCARINA COMPONENTS                             --
--                                                                          --
--                    A R A O . C Y C L I C _ A R R A Y                     --
--                                                                          --
--                                 S p e c                                  --
--                                                                          --
--                 Copyright (C) 2006, GET-Telecom Paris.                   --
--                                                                          --
-- Ocarina  is free software;  you  can  redistribute  it and/or  modify    --
-- it under terms of the GNU General Public License as published by the     --
-- Free Software Foundation; either version 2, or (at your option) any      --
-- later version. Ocarina is distributed  in  the  hope  that it will be    --
-- useful, but WITHOUT 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 Ocarina; see file COPYING.   --
-- If not, write to the Free Software Foundation, 51 Franklin Street, Fifth --
-- Floor, Boston, MA 02111-1301, 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.                                       --
--                                                                          --
--                 Ocarina is maintained by the Ocarina team                --
--                       (ocarina-users@listes.enst.fr)                     --
--                                                                          --
------------------------------------------------------------------------------

generic
   type Element is private;
   Max_Size : Positive;

package ARAO.Cyclic_Array is

   type Table is private;

   procedure Get
     (T     : in out Table;
      Item  :    out Element;
      Empty :    out Boolean);
   --  Return the oldest entered value

   procedure Append
     (T    : in out Table;
      Item :        Element;
      Full :    out Boolean);
   --  Add the value at Fifo's end. Should be the "normal" way of
   --  using FIFO.

   procedure Push_Back
     (T    : in out Table;
      Item :        Element;
      Full :    out Boolean);
   --  Add the value at Fifo's beginning. Should be used only to
   --  "undo" a "Get" call.

private

   type Data_Array is array (1 .. Max_Size) of Element;

   type Table is record
      Data     : Data_Array;
      Beg_Curs : Integer := 1;
      End_Curs : Integer := 0;
      Empty    : Boolean := True;
   end record;

end ARAO.Cyclic_Array;