1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . H T A B L E --
9 -- Copyright (C) 1995-2008, 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
;
38 package body System
.HTable
is
44 package body Static_HTable
is
46 Table
: array (Header_Num
) of Elmt_Ptr
;
48 Iterator_Index
: Header_Num
;
49 Iterator_Ptr
: Elmt_Ptr
;
50 Iterator_Started
: Boolean := False;
52 function Get_Non_Null
return Elmt_Ptr
;
53 -- Returns Null_Ptr if Iterator_Started is false or the Table is empty.
54 -- Returns Iterator_Ptr if non null, or the next non null element in
61 function Get
(K
: Key
) return Elmt_Ptr
is
65 Elmt
:= Table
(Hash
(K
));
68 if Elmt
= Null_Ptr
then
71 elsif Equal
(Get_Key
(Elmt
), K
) then
84 function Get_First
return Elmt_Ptr
is
86 Iterator_Started
:= True;
87 Iterator_Index
:= Table
'First;
88 Iterator_Ptr
:= Table
(Iterator_Index
);
96 function Get_Next
return Elmt_Ptr
is
98 if not Iterator_Started
then
102 Iterator_Ptr
:= Next
(Iterator_Ptr
);
110 function Get_Non_Null
return Elmt_Ptr
is
112 while Iterator_Ptr
= Null_Ptr
loop
113 if Iterator_Index
= Table
'Last then
114 Iterator_Started
:= False;
118 Iterator_Index
:= Iterator_Index
+ 1;
119 Iterator_Ptr
:= Table
(Iterator_Index
);
129 procedure Remove
(K
: Key
) is
130 Index
: constant Header_Num
:= Hash
(K
);
132 Next_Elmt
: Elmt_Ptr
;
135 Elmt
:= Table
(Index
);
137 if Elmt
= Null_Ptr
then
140 elsif Equal
(Get_Key
(Elmt
), K
) then
141 Table
(Index
) := Next
(Elmt
);
145 Next_Elmt
:= Next
(Elmt
);
147 if Next_Elmt
= Null_Ptr
then
150 elsif Equal
(Get_Key
(Next_Elmt
), K
) then
151 Set_Next
(Elmt
, Next
(Next_Elmt
));
167 for J
in Table
'Range loop
168 Table
(J
) := Null_Ptr
;
176 procedure Set
(E
: Elmt_Ptr
) is
180 Index
:= Hash
(Get_Key
(E
));
181 Set_Next
(E
, Table
(Index
));
191 package body Simple_HTable
is
193 type Element_Wrapper
;
194 type Elmt_Ptr
is access all Element_Wrapper
;
195 type Element_Wrapper
is record
201 procedure Free
is new
202 Ada
.Unchecked_Deallocation
(Element_Wrapper
, Elmt_Ptr
);
204 procedure Set_Next
(E
: Elmt_Ptr
; Next
: Elmt_Ptr
);
205 function Next
(E
: Elmt_Ptr
) return Elmt_Ptr
;
206 function Get_Key
(E
: Elmt_Ptr
) return Key
;
208 package Tab
is new Static_HTable
(
209 Header_Num
=> Header_Num
,
210 Element
=> Element_Wrapper
,
211 Elmt_Ptr
=> Elmt_Ptr
,
213 Set_Next
=> Set_Next
,
224 function Get
(K
: Key
) return Element
is
225 Tmp
: constant Elmt_Ptr
:= Tab
.Get
(K
);
238 function Get_First
return Element
is
239 Tmp
: constant Elmt_Ptr
:= Tab
.Get_First
;
252 function Get_Key
(E
: Elmt_Ptr
) return Key
is
261 function Get_Next
return Element
is
262 Tmp
: constant Elmt_Ptr
:= Tab
.Get_Next
;
275 function Next
(E
: Elmt_Ptr
) return Elmt_Ptr
is
284 procedure Remove
(K
: Key
) is
305 while E1
/= null loop
318 procedure Set
(K
: Key
; E
: Element
) is
319 Tmp
: constant Elmt_Ptr
:= Tab
.Get
(K
);
322 Tab
.Set
(new Element_Wrapper
'(K, E, null));
332 procedure Set_Next (E : Elmt_Ptr; Next : Elmt_Ptr) is
342 function Hash (Key : String) return Header_Num is
344 type Uns is mod 2 ** 32;
346 function Rotate_Left (Value : Uns; Amount : Natural) return Uns;
347 pragma Import (Intrinsic, Rotate_Left);
353 for J in Key'Range loop
354 Hash_Value := Rotate_Left (Hash_Value, 3) + Character'Pos (Key (J));
357 return Header_Num'First +
358 Header_Num'Base (Hash_Value mod Header_Num'Range_Length);