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230 | ------------------------------------------------------------------------------
-- G N A T C O L L --
-- --
-- Copyright (C) 2010-2017, AdaCore --
-- --
-- This library is free software; you can redistribute it and/or modify it --
-- under terms of the GNU General Public License as published by the Free --
-- Software Foundation; either version 3, or (at your option) any later --
-- version. This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- 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/>. --
-- --
------------------------------------------------------------------------------
with Ada.Containers; use Ada.Containers;
with Ada.Strings.Hash;
with Ada.Unchecked_Conversion;
with Ada.Unchecked_Deallocation;
with GNAT.IO; use GNAT.IO;
with GNAT.Strings;
with System.Address_Image;
package body GNATCOLL.Symbols is
use String_Htable;
Table_Size : constant := 98_317;
-- The initial capacity of the htable. This was computed from inserting
-- all entities from the GPS project, using Ada.Strings.Hash for the hash,
-- but seems to be the same when using other hash codes.
-- The table will readjust itself anyway, but setting this properly avoids
-- a few resizing.
-----------------
-- Debug_Print --
-----------------
function Debug_Print (S : Symbol) return String is
begin
if S = No_Symbol then
return "<Symbol: null>";
else
return "<Symbol: " & System.Address_Image (S.all'Address)
& " {" & S.all & "}>";
end if;
end Debug_Print;
----------
-- Hash --
----------
function Hash (Str : Cst_String_Access) return Hash_Type is
begin
return Ada.Strings.Hash (Str.all);
end Hash;
---------------
-- Key_Equal --
---------------
function Key_Equal (Key1, Key2 : Cst_String_Access) return Boolean is
begin
return Key1.all = Key2.all;
end Key_Equal;
----------
-- Find --
----------
function Find
(Table : access Symbol_Table_Record;
Str : String) return Symbol
is
Result : String_Htable.Cursor;
Tmp : Cst_String_Access;
begin
if Str'Length = 0 then
return Empty_String;
else
Table.Calls_To_Find := Table.Calls_To_Find + 1;
Result := Table.Hash.Find (Str'Unrestricted_Access);
if not Has_Element (Result) then
Table.Total_Size := Table.Total_Size + Str'Length;
Tmp := new String'(Str);
Table.Hash.Include (Tmp);
return Symbol (Tmp);
else
Table.Size_Saved := Table.Size_Saved + Str'Length;
end if;
return Symbol (Element (Result));
end if;
end Find;
-------------------
-- Display_Stats --
-------------------
procedure Display_Stats (Self : access Symbol_Table_Record) is
C : String_Htable.Cursor := Self.Hash.First;
Tmp : Cst_String_Access;
Count : Natural := 0;
Last : Hash_Type := Hash_Type'Last;
H : Hash_Type;
Bucket_Count : Natural := 0;
begin
while Has_Element (C) loop
Tmp := Element (C);
H := Hash (Tmp);
if H = Last then
Count := Count + 1;
else
if Last /= Hash_Type'Last then
Put_Line ("Bucket" & Last'Img & " =>" & Count'Img & " entries");
end if;
Last := H;
Count := 1;
Bucket_Count := Bucket_Count + 1;
end if;
Put_Line (Hash (Tmp)'Img & " => " & Tmp.all);
Next (C);
end loop;
Put_Line ("Total calls to Find: " & Self.Calls_To_Find'Img);
Put_Line ("Number of entries in the symbols table:"
& Self.Hash.Length'Img);
Put_Line ("Maximum number of buckets:" & Self.Hash.Capacity'Img);
Put_Line ("Number of buckets used:" & Bucket_Count'Img);
Put_Line ("Mean entries per bucket:"
& Integer'Image (Integer (Self.Hash.Length) / Bucket_Count));
Put_Line ("Total size in strings:" & Self.Total_Size'Img);
Put_Line ("Size that would have been allocated for strings:"
& Self.Size_Saved'Img);
end Display_Stats;
---------
-- Get --
---------
function Get
(Sym : Symbol; Empty_If_Null : Boolean := True) return Cst_String_Access
is
begin
if Sym = No_Symbol then
if Empty_If_Null then
return Cst_String_Access (Empty_String);
else
return null;
end if;
else
return Cst_String_Access (Sym);
end if;
end Get;
----------
-- Free --
----------
procedure Free (Table : in out Symbol_Table_Record) is
function Convert is new Ada.Unchecked_Conversion
(Cst_String_Access, GNAT.Strings.String_Access);
procedure Unchecked_Free is new Ada.Unchecked_Deallocation
(String, GNAT.Strings.String_Access);
S : GNAT.Strings.String_Access;
C : String_Htable.Cursor := Table.Hash.First;
Tmp : Cst_String_Access;
begin
while Has_Element (C) loop
Tmp := Element (C);
Next (C);
S := Convert (Tmp);
Unchecked_Free (S);
end loop;
Table.Hash.Clear;
end Free;
----------
-- Free --
----------
procedure Free (Table : in out Symbol_Table_Access) is
procedure Unchecked_Free is new Ada.Unchecked_Deallocation
(Symbol_Table_Record'Class, Symbol_Table_Access);
begin
if Table /= null then
Free (Table.all);
Unchecked_Free (Table);
end if;
end Free;
----------
-- Hash --
----------
function Hash (S : Symbol) return Hash_Type is
begin
return Hash (Cst_String_Access (S));
end Hash;
--------------
-- Allocate --
--------------
function Allocate return Symbol_Table_Access is
T : constant Symbol_Table_Access := new Symbol_Table_Record;
begin
T.Hash.Reserve_Capacity (Table_Size);
return T;
end Allocate;
end GNATCOLL.Symbols;
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