1 ------------------------------------------------------------------------------
3 -- GNAT RUNTIME COMPONENTS --
5 -- G N A T . T A B L E --
9 -- Copyright (C) 1998-2002 Ada Core Technologies, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 with System
; use System
;
35 with System
.Memory
; use System
.Memory
;
37 with Unchecked_Conversion
;
39 package body GNAT
.Table
is
41 Min
: constant Integer := Integer (Table_Low_Bound
);
42 -- Subscript of the minimum entry in the currently allocated table
45 -- Subscript of the maximum entry in the currently allocated table
47 Length
: Integer := 0;
48 -- Number of entries in currently allocated table. The value of zero
49 -- ensures that we initially allocate the table.
52 -- Current value of Last.
54 -----------------------
55 -- Local Subprograms --
56 -----------------------
59 -- Reallocate the existing table according to the current value stored
60 -- in Max. Works correctly to do an initial allocation if the table
63 function To_Address
is new Unchecked_Conversion
(Table_Ptr
, Address
);
64 function To_Pointer
is new Unchecked_Conversion
(Address
, Table_Ptr
);
70 function Allocate
(Num
: Integer := 1) return Table_Index_Type
is
71 Old_Last
: constant Integer := Last_Val
;
74 Last_Val
:= Last_Val
+ Num
;
76 if Last_Val
> Max
then
80 return Table_Index_Type
(Old_Last
+ 1);
87 procedure Append
(New_Val
: Table_Component_Type
) is
90 Table
(Table_Index_Type
(Last_Val
)) := New_Val
;
97 procedure Decrement_Last
is
99 Last_Val
:= Last_Val
- 1;
108 Free
(To_Address
(Table
));
117 procedure Increment_Last
is
119 Last_Val
:= Last_Val
+ 1;
121 if Last_Val
> Max
then
131 Old_Length
: constant Integer := Length
;
135 Max
:= Min
+ Table_Initial
- 1;
136 Length
:= Max
- Min
+ 1;
138 -- If table is same size as before (happens when table is never
139 -- expanded which is a common case), then simply reuse it. Note
140 -- that this also means that an explicit Init call right after
141 -- the implicit one in the package body is harmless.
143 if Old_Length
= Length
then
146 -- Otherwise we can use Reallocate to get a table of the right size.
147 -- Note that Reallocate works fine to allocate a table of the right
148 -- initial size when it is first allocated.
159 function Last
return Table_Index_Type
is
161 return Table_Index_Type
(Last_Val
);
168 procedure Reallocate
is
172 if Max
< Last_Val
then
173 pragma Assert
(not Locked
);
175 while Max
< Last_Val
loop
177 -- Increase length using the table increment factor, but make
178 -- sure that we add at least ten elements (this avoids a loop
179 -- for silly small increment values)
181 Length
:= Integer'Max
182 (Length
* (100 + Table_Increment
) / 100,
184 Max
:= Min
+ Length
- 1;
189 size_t
((Max
- Min
+ 1) *
190 (Table_Type
'Component_Size / Storage_Unit
));
193 Table
:= To_Pointer
(Alloc
(New_Size
));
195 elsif New_Size
> 0 then
197 To_Pointer
(Realloc
(Ptr
=> To_Address
(Table
),
201 if Length
/= 0 and then Table
= null then
213 Length
:= Last_Val
- Integer (Table_Low_Bound
) + 1;
223 (Index
: Table_Index_Type
;
224 Item
: Table_Component_Type
)
227 if Integer (Index
) > Max
then
231 Table
(Index
) := Item
;
238 procedure Set_Last
(New_Val
: Table_Index_Type
) is
240 if Integer (New_Val
) < Last_Val
then
241 Last_Val
:= Integer (New_Val
);
243 Last_Val
:= Integer (New_Val
);
245 if Last_Val
> Max
then