1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- G N A T . D Y N A M I C _ T A B L E S --
9 -- Copyright (C) 2000-2006, AdaCore --
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, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, 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 GNAT.Heap_Sort_G;
35 with System; use System;
36 with System.Memory; use System.Memory;
38 with Unchecked_Conversion;
40 package body GNAT.Dynamic_Tables is
42 Min : constant Integer := Integer (Table_Low_Bound);
43 -- Subscript of the minimum entry in the currently allocated table
45 -----------------------
46 -- Local Subprograms --
47 -----------------------
49 procedure Reallocate (T : in out Instance);
50 -- Reallocate the existing table according to the current value stored
51 -- in Max. Works correctly to do an initial allocation if the table
54 pragma Warnings (Off);
55 -- These unchecked conversions are in fact safe, since they never
56 -- generate improperly aliased pointer values.
58 function To_Address is new Unchecked_Conversion (Table_Ptr, Address);
59 function To_Pointer is new Unchecked_Conversion (Address, Table_Ptr);
72 T.P.Last_Val := T.P.Last_Val + Num;
74 if T.P.Last_Val > T.P.Max then
83 procedure Append (T : in out Instance; New_Val : Table_Component_Type) is
86 T.Table (Table_Index_Type (T.P.Last_Val)) := New_Val;
93 procedure Decrement_Last (T : in out Instance) is
95 T.P.Last_Val := T.P.Last_Val - 1;
102 procedure For_Each (Table : Instance) is
103 Quit : Boolean := False;
105 for Index in Table_Low_Bound .. Table_Index_Type (Table.P.Last_Val) loop
106 Action (Index, Table.Table (Index), Quit);
115 procedure Free (T : in out Instance) is
117 Free (To_Address (T.Table));
126 procedure Increment_Last (T : in out Instance) is
128 T.P.Last_Val := T.P.Last_Val + 1;
130 if T.P.Last_Val > T.P.Max then
139 procedure Init (T : in out Instance) is
140 Old_Length : constant Integer := T.P.Length;
143 T.P.Last_Val := Min - 1;
144 T.P.Max := Min + Table_Initial - 1;
145 T.P.Length := T.P.Max - Min + 1;
147 -- If table is same size as before (happens when table is never
148 -- expanded which is a common case), then simply reuse it. Note
149 -- that this also means that an explicit Init call right after
150 -- the implicit one in the package body is harmless.
152 if Old_Length = T.P.Length then
155 -- Otherwise we can use Reallocate to get a table of the right size.
156 -- Note that Reallocate works fine to allocate a table of the right
157 -- initial size when it is first allocated.
168 function Last (T : Instance) return Table_Index_Type is
170 return Table_Index_Type (T.P.Last_Val);
177 procedure Reallocate (T : in out Instance) is
178 New_Length : Integer;
182 if T.P.Max < T.P.Last_Val then
183 while T.P.Max < T.P.Last_Val loop
184 New_Length := T.P.Length * (100 + Table_Increment) / 100;
186 if New_Length > T.P.Length then
187 T.P.Length := New_Length;
189 T.P.Length := T.P.Length + 1;
192 T.P.Max := Min + T.P.Length - 1;
197 size_t ((T.P.Max - Min + 1) *
198 (Table_Type'Component_Size / Storage_Unit));
200 if T.Table = null then
201 T.Table := To_Pointer (Alloc (New_Size));
203 elsif New_Size > 0 then
205 To_Pointer (Realloc (Ptr => To_Address (T.Table),
209 if T.P.Length /= 0 and then T.Table = null then
218 procedure Release (T : in out Instance) is
220 T.P.Length := T.P.Last_Val - Integer (Table_Low_Bound) + 1;
221 T.P.Max := T.P.Last_Val;
230 (T : in out Instance;
231 Index : Table_Index_Type;
232 Item : Table_Component_Type)
235 if Integer (Index) > T.P.Last_Val then
239 T.Table (Index) := Item;
246 procedure Set_Last (T : in out Instance; New_Val : Table_Index_Type) is
248 if Integer (New_Val) < T.P.Last_Val then
249 T.P.Last_Val := Integer (New_Val);
252 T.P.Last_Val := Integer (New_Val);
254 if T.P.Last_Val > T.P.Max then
264 procedure Sort_Table (Table : in out Instance) is
266 Temp : Table_Component_Type;
267 -- A temporary position to simulate index 0
271 function Index_Of (Idx : Natural) return Table_Index_Type;
272 -- Apply Natural to indexs of the table
274 function Lower_Than (Op1, Op2 : Natural) return Boolean;
275 -- Compare two components
277 procedure Move (From : Natural; To : Natural);
278 -- Move one component
280 package Heap_Sort is new GNAT.Heap_Sort_G (Move, Lower_Than);
286 function Index_Of (Idx : Natural) return Table_Index_Type is
287 J : constant Integer'Base :=
288 Table_Index_Type'Pos (First) + Idx - 1;
290 return Table_Index_Type'Val (J);
297 procedure Move (From : Natural; To : Natural) is
300 Table.Table (Index_Of (To)) := Temp;
303 Temp := Table.Table (Index_Of (From));
306 Table.Table (Index_Of (To)) :=
307 Table.Table (Index_Of (From));
315 function Lower_Than (Op1, Op2 : Natural) return Boolean is
318 return Lt (Temp, Table.Table (Index_Of (Op2)));
321 return Lt (Table.Table (Index_Of (Op1)), Temp);
325 Lt (Table.Table (Index_Of (Op1)),
326 Table.Table (Index_Of (Op2)));
330 -- Start of processing for Sort_Table
333 Heap_Sort.Sort (Natural (Last (Table) - First) + 1);
336 end GNAT.Dynamic_Tables;