------------------------------------------------------------------------------
-- --
--- GNAT RUNTIME COMPONENTS --
+-- GNAT RUN-TIME COMPONENTS --
-- --
-- S Y S T E M . H T A B L E --
-- --
-- B o d y --
-- --
--- Copyright (C) 1995-2004 Ada Core Technologies, Inc. --
+-- Copyright (C) 1995-2011, AdaCore --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
--- ware Foundation; either version 2, or (at your option) any later ver- --
+-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
--- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
--- As a special exception, if other files instantiate generics from this --
--- unit, or you link this unit with other files to produce an executable, --
--- this unit does not by itself cause the resulting executable to be --
--- covered by the GNU General Public License. This exception does not --
--- however invalidate any other reasons why the executable file might be --
--- covered by the GNU Public License. --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception, --
+-- version 3.1, as published by the Free Software Foundation. --
+-- --
+-- You should have received a copy of the GNU General Public License and --
+-- a copy of the GCC Runtime Library Exception along with this program; --
+-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
+-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
+pragma Compiler_Unit;
+
with Ada.Unchecked_Deallocation;
+with System.String_Hash;
package body System.HTable is
- --------------------
- -- Static_HTable --
- --------------------
+ -------------------
+ -- Static_HTable --
+ -------------------
package body Static_HTable is
Iterator_Started : Boolean := False;
function Get_Non_Null return Elmt_Ptr;
- -- Returns Null_Ptr if Iterator_Started is false of the Table is
- -- empty. Returns Iterator_Ptr if non null, or the next non null
- -- element in table if any.
+ -- Returns Null_Ptr if Iterator_Started is false or the Table is empty.
+ -- Returns Iterator_Ptr if non null, or the next non null element in
+ -- table if any.
---------
-- Get --
function Get_Non_Null return Elmt_Ptr is
begin
- while Iterator_Ptr = Null_Ptr loop
+ while Iterator_Ptr = Null_Ptr loop
if Iterator_Index = Table'Last then
Iterator_Started := False;
return Null_Ptr;
return Iterator_Ptr;
end Get_Non_Null;
+ -------------
+ -- Present --
+ -------------
+
+ function Present (K : Key) return Boolean is
+ begin
+ return Get (K) /= Null_Ptr;
+ end Present;
+
------------
-- Remove --
------------
Table (Index) := E;
end Set;
+ ------------------------
+ -- Set_If_Not_Present --
+ ------------------------
+
+ function Set_If_Not_Present (E : Elmt_Ptr) return Boolean is
+ K : Key renames Get_Key (E);
+ -- Note that it is important to use a renaming here rather than
+ -- define a constant initialized by the call, because the latter
+ -- construct runs into bootstrap problems with earlier versions
+ -- of the GNAT compiler.
+
+ Index : constant Header_Num := Hash (K);
+ Elmt : Elmt_Ptr;
+
+ begin
+ Elmt := Table (Index);
+ loop
+ if Elmt = Null_Ptr then
+ Set_Next (E, Table (Index));
+ Table (Index) := E;
+ return True;
+
+ elsif Equal (Get_Key (Elmt), K) then
+ return False;
+
+ else
+ Elmt := Next (Elmt);
+ end if;
+ end loop;
+ end Set_If_Not_Present;
+
end Static_HTable;
-------------------
end if;
end Get_First;
+ procedure Get_First (K : in out Key; E : out Element) is
+ Tmp : constant Elmt_Ptr := Tab.Get_First;
+ begin
+ if Tmp = null then
+ E := No_Element;
+ else
+ K := Tmp.K;
+ E := Tmp.E;
+ end if;
+ end Get_First;
+
-------------
-- Get_Key --
-------------
end if;
end Get_Next;
+ procedure Get_Next (K : in out Key; E : out Element) is
+ Tmp : constant Elmt_Ptr := Tab.Get_Next;
+ begin
+ if Tmp = null then
+ E := No_Element;
+ else
+ K := Tmp.K;
+ E := Tmp.E;
+ end if;
+ end Get_Next;
+
----------
-- Next --
----------
----------
function Hash (Key : String) return Header_Num is
-
type Uns is mod 2 ** 32;
- function Rotate_Left (Value : Uns; Amount : Natural) return Uns;
- pragma Import (Intrinsic, Rotate_Left);
-
- Hash_Value : Uns;
+ function Hash_Fun is
+ new System.String_Hash.Hash (Character, String, Uns);
begin
- Hash_Value := 0;
- for J in Key'Range loop
- Hash_Value := Rotate_Left (Hash_Value, 3) + Character'Pos (Key (J));
- end loop;
-
return Header_Num'First +
- Header_Num'Base (Hash_Value mod Header_Num'Range_Length);
+ Header_Num'Base (Hash_Fun (Key) mod Header_Num'Range_Length);
end Hash;
end System.HTable;
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