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