File : adagio-bandwidth_manager.ads


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--                         ADAGIO - ADALID - AENEA.                         --

--                                                                          --

--                            Copyright (C) 2003                            --

--                                 A. Mosteo.                               --

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--  Authors: A. Mosteo. (adagio@mosteo.com)                                 --

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--  $Id: adagio-bandwidth_manager.ads,v 1.7 2004/03/22 07:14:57 Jano Exp $


--  Task for bandwidth management


with Ada.Calendar;
use  Ada;

package Adagio.Bandwidth_manager is

   -- Bandwidth is the bytes/second to manage

   -- Period is the period for feedback. Longer ones allow the use

   --    of unused bandwidth for more time. (In milliseconds)

   protected type Object (Bandwidth : Speed; Period : Natural) is

      -- Gives the available bandwidth at this moment (real + extra):

      procedure Available (Bandwidth : out Natural);

      -- Issue a bandwidth petition. Awarded can be less that solicited.

      -- Extra flag requests bandwidth from unused past cycles.

      procedure Commit (
         Desired : in  Natural; 
         Awarded : out Natural;
         Extra   : in  Boolean := false);

   private

      Gap      : Duration      := Duration (Period) / 1000.0;

      Remanent : Natural       := 0;
      Unused   : Natural       := 0;
      Last_req : Calendar.Time := Calendar.Clock;

   end Object;

   type Object_access is access all Object;

end Adagio.Bandwidth_manager;