File : a-cbprqu.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT LIBRARY COMPONENTS --
4 -- --
5 -- ADA.CONTAINERS.BOUNDED_PRIORITY_QUEUES --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 2011-2015, Free Software Foundation, Inc. --
10 -- --
11 -- This specification is derived from the Ada Reference Manual for use with --
12 -- GNAT. The copyright notice above, and the license provisions that follow --
13 -- apply solely to the contents of the part following the private keyword. --
14 -- --
15 -- GNAT is free software; you can redistribute it and/or modify it under --
16 -- terms of the GNU General Public License as published by the Free Soft- --
17 -- ware Foundation; either version 3, or (at your option) any later ver- --
18 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
19 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
20 -- or FITNESS FOR A PARTICULAR PURPOSE. --
21 -- --
22 -- --
23 -- --
24 -- --
25 -- --
26 -- You should have received a copy of the GNU General Public License and --
27 -- a copy of the GCC Runtime Library Exception along with this program; --
28 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
29 -- <http://www.gnu.org/licenses/>. --
30 -- --
31 -- This unit was originally developed by Matthew J Heaney. --
32 ------------------------------------------------------------------------------
33
34 with System;
35
36 with Ada.Containers.Synchronized_Queue_Interfaces;
37 with Ada.Containers.Bounded_Doubly_Linked_Lists;
38
39 generic
40 with package Queue_Interfaces is
41 new Ada.Containers.Synchronized_Queue_Interfaces (<>);
42
43 type Queue_Priority is private;
44
45 with function Get_Priority
46 (Element : Queue_Interfaces.Element_Type) return Queue_Priority is <>;
47
48 with function Before
49 (Left, Right : Queue_Priority) return Boolean is <>;
50
51 Default_Capacity : Count_Type;
52 Default_Ceiling : System.Any_Priority := System.Priority'Last;
53
54 package Ada.Containers.Bounded_Priority_Queues is
55 pragma Annotate (CodePeer, Skip_Analysis);
56 pragma Preelaborate;
57
58 package Implementation is
59
60 -- All identifiers in this unit are implementation defined
61
62 pragma Implementation_Defined;
63
64 type List_Type (Capacity : Count_Type) is tagged limited private;
65
66 procedure Enqueue
67 (List : in out List_Type;
68 New_Item : Queue_Interfaces.Element_Type);
69
70 procedure Dequeue
71 (List : in out List_Type;
72 Element : out Queue_Interfaces.Element_Type);
73
74 procedure Dequeue
75 (List : in out List_Type;
76 At_Least : Queue_Priority;
77 Element : in out Queue_Interfaces.Element_Type;
78 Success : out Boolean);
79
80 function First_Element
81 (List : List_Type) return Queue_Interfaces.Element_Type;
82
83 function Length (List : List_Type) return Count_Type;
84
85 function Max_Length (List : List_Type) return Count_Type;
86
87 private
88
89 -- We need a better data structure here, such as a proper heap. ???
90
91 package List_Types is new Bounded_Doubly_Linked_Lists
92 (Element_Type => Queue_Interfaces.Element_Type,
93 "=" => Queue_Interfaces."=");
94
95 type List_Type (Capacity : Count_Type) is tagged limited record
96 Container : List_Types.List (Capacity);
97 Max_Length : Count_Type := 0;
98 end record;
99
100 end Implementation;
101
102 protected type Queue
103 (Capacity : Count_Type := Default_Capacity;
104 Ceiling : System.Any_Priority := Default_Ceiling)
105 with
106 Priority => Ceiling
107 is new Queue_Interfaces.Queue with
108
109 overriding entry Enqueue (New_Item : Queue_Interfaces.Element_Type);
110
111 overriding entry Dequeue (Element : out Queue_Interfaces.Element_Type);
112
113 -- The priority queue operation Dequeue_Only_High_Priority had been a
114 -- protected entry in early drafts of AI05-0159, but it was discovered
115 -- that that operation as specified was not in fact implementable. The
116 -- operation was changed from an entry to a protected procedure per the
117 -- ARG meeting in Edinburgh (June 2011), with a different signature and
118 -- semantics.
119
120 procedure Dequeue_Only_High_Priority
121 (At_Least : Queue_Priority;
122 Element : in out Queue_Interfaces.Element_Type;
123 Success : out Boolean);
124
125 overriding function Current_Use return Count_Type;
126
127 overriding function Peak_Use return Count_Type;
128
129 private
130 List : Implementation.List_Type (Capacity);
131 end Queue;
132
133 end Ada.Containers.Bounded_Priority_Queues;