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------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- ADA.CONTAINERS.UNBOUNDED_PRIORITY_QUEUES --
-- --
-- B o d y --
-- --
-- Copyright (C) 2011-2022, 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/>. --
-- --
-- This unit was originally developed by Matthew J Heaney. --
------------------------------------------------------------------------------
package body Ada.Containers.Unbounded_Priority_Queues is
protected body Queue is
-----------------
-- Current_Use --
-----------------
function Current_Use return Count_Type is
begin
return Q_Elems.Length;
end Current_Use;
-------------
-- Dequeue --
-------------
entry Dequeue (Element : out Queue_Interfaces.Element_Type)
when Q_Elems.Length > 0
is
-- Grab the first item of the set, and remove it from the set
C : constant Cursor := First (Q_Elems);
begin
Element := Sets.Element (C).Item;
Delete_First (Q_Elems);
end Dequeue;
--------------------------------
-- Dequeue_Only_High_Priority --
--------------------------------
procedure Dequeue_Only_High_Priority
(At_Least : Queue_Priority;
Element : in out Queue_Interfaces.Element_Type;
Success : out Boolean)
is
-- Grab the first item. If it exists and has appropriate priority,
-- set Success to True, and remove that item. Otherwise, set Success
-- to False.
C : constant Cursor := First (Q_Elems);
begin
Success := Has_Element (C) and then
not Before (At_Least, Get_Priority (Sets.Element (C).Item));
if Success then
Element := Sets.Element (C).Item;
Delete_First (Q_Elems);
end if;
end Dequeue_Only_High_Priority;
-------------
-- Enqueue --
-------------
entry Enqueue (New_Item : Queue_Interfaces.Element_Type) when True is
begin
Insert (Q_Elems, (Next_Sequence_Number, New_Item));
Next_Sequence_Number := Next_Sequence_Number + 1;
-- If we reached a new high-water mark, increase Max_Length
if Q_Elems.Length > Max_Length then
pragma Assert (Max_Length + 1 = Q_Elems.Length);
Max_Length := Q_Elems.Length;
end if;
end Enqueue;
--------------
-- Peak_Use --
--------------
function Peak_Use return Count_Type is
begin
return Max_Length;
end Peak_Use;
end Queue;
end Ada.Containers.Unbounded_Priority_Queues;