1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . H T A B L E --
9 -- Copyright (C) 1995-2009, 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 ------------------------------------------------------------------------------
36 with Ada.Unchecked_Deallocation;
37 with System.String_Hash;
39 package body System.HTable is
45 package body Static_HTable is
47 Table : array (Header_Num) of Elmt_Ptr;
49 Iterator_Index : Header_Num;
50 Iterator_Ptr : Elmt_Ptr;
51 Iterator_Started : Boolean := False;
53 function Get_Non_Null return Elmt_Ptr;
54 -- Returns Null_Ptr if Iterator_Started is false or the Table is empty.
55 -- Returns Iterator_Ptr if non null, or the next non null element in
62 function Get (K : Key) return Elmt_Ptr is
66 Elmt := Table (Hash (K));
69 if Elmt = Null_Ptr then
72 elsif Equal (Get_Key (Elmt), K) then
85 function Get_First return Elmt_Ptr is
87 Iterator_Started := True;
88 Iterator_Index := Table'First;
89 Iterator_Ptr := Table (Iterator_Index);
97 function Get_Next return Elmt_Ptr is
99 if not Iterator_Started then
103 Iterator_Ptr := Next (Iterator_Ptr);
111 function Get_Non_Null return Elmt_Ptr is
113 while Iterator_Ptr = Null_Ptr loop
114 if Iterator_Index = Table'Last then
115 Iterator_Started := False;
119 Iterator_Index := Iterator_Index + 1;
120 Iterator_Ptr := Table (Iterator_Index);
130 procedure Remove (K : Key) is
131 Index : constant Header_Num := Hash (K);
133 Next_Elmt : Elmt_Ptr;
136 Elmt := Table (Index);
138 if Elmt = Null_Ptr then
141 elsif Equal (Get_Key (Elmt), K) then
142 Table (Index) := Next (Elmt);
146 Next_Elmt := Next (Elmt);
148 if Next_Elmt = Null_Ptr then
151 elsif Equal (Get_Key (Next_Elmt), K) then
152 Set_Next (Elmt, Next (Next_Elmt));
168 for J in Table'Range loop
169 Table (J) := Null_Ptr;
177 procedure Set (E : Elmt_Ptr) is
181 Index := Hash (Get_Key (E));
182 Set_Next (E, Table (Index));
192 package body Simple_HTable is
194 type Element_Wrapper;
195 type Elmt_Ptr is access all Element_Wrapper;
196 type Element_Wrapper is record
202 procedure Free is new
203 Ada.Unchecked_Deallocation (Element_Wrapper, Elmt_Ptr);
205 procedure Set_Next (E : Elmt_Ptr; Next : Elmt_Ptr);
206 function Next (E : Elmt_Ptr) return Elmt_Ptr;
207 function Get_Key (E : Elmt_Ptr) return Key;
209 package Tab is new Static_HTable (
210 Header_Num => Header_Num,
211 Element => Element_Wrapper,
212 Elmt_Ptr => Elmt_Ptr,
214 Set_Next => Set_Next,
225 function Get (K : Key) return Element is
226 Tmp : constant Elmt_Ptr := Tab.Get (K);
239 function Get_First return Element is
240 Tmp : constant Elmt_Ptr := Tab.Get_First;
253 function Get_Key (E : Elmt_Ptr) return Key is
262 function Get_Next return Element is
263 Tmp : constant Elmt_Ptr := Tab.Get_Next;
276 function Next (E : Elmt_Ptr) return Elmt_Ptr is
285 procedure Remove (K : Key) is
306 while E1 /= null loop
319 procedure Set (K : Key; E : Element) is
320 Tmp : constant Elmt_Ptr := Tab.Get (K);
323 Tab.Set (new Element_Wrapper'(K, E, null));
333 procedure Set_Next (E : Elmt_Ptr; Next : Elmt_Ptr) is
343 function Hash (Key : String) return Header_Num is
344 type Uns is mod 2 ** 32;
347 new System.String_Hash.Hash (Character, String, Uns);
350 return Header_Num'First +
351 Header_Num'Base (Hash_Fun (Key) mod Header_Num'Range_Length);