File : aws-utils.adb


------------------------------------------------------------------------------

--                              Ada Web Server                              --

--                                                                          --

--                         Copyright (C) 2000-2003                          --

--                                ACT-Europe                                --

--                                                                          --

--  Authors: Dmitriy Anisimkov - Pascal Obry                                --

--                                                                          --

--  This library is free software; you can redistribute it and/or modify    --

--  it under the terms of the GNU General Public License as published by    --

--  the Free Software Foundation; either version 2 of the License, 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              --

--  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       --

--  along with this library; if not, write to the Free Software Foundation, --

--  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.          --

--                                                                          --

--  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.                                     --

------------------------------------------------------------------------------


--  $Id: aws-utils.adb,v 1.1 2003/10/05 20:00:06 Jano Exp $


with Ada.Integer_Text_IO;
with Ada.Strings.Fixed;
with Ada.Strings.Maps.Constants;
with Ada.Numerics.Discrete_Random;

package body AWS.Utils is

   use Ada;

   package Integer_Random is new Ada.Numerics.Discrete_Random (Random_Integer);

   Random_Generator : Integer_Random.Generator;

   -------------------

   -- CRLF_2_Spaces --

   -------------------


   function CRLF_2_Spaces (Str : in String) return String is
   begin
      return Strings.Fixed.Trim
        (Strings.Fixed.Translate
           (Str, Strings.Maps.To_Mapping
              (From => ASCII.CR & ASCII.LF, To   => "  ")),
         Strings.Right);
   end CRLF_2_Spaces;

   -------------

   -- Get_MD5 --

   -------------


   function Get_MD5 (Data : in String) return MD5.Digest_String is
      Ctx : MD5.Context;
      HA  : MD5.Fingerprint;
   begin
      MD5.Init (Ctx);
      MD5.Update (Ctx, Data);
      MD5.Final (Ctx, HA);
      return MD5.Digest_To_Text (HA);
   end Get_MD5;

   ---------

   -- Hex --

   ---------


   function Hex (V : in Natural; Width : in Natural := 0) return String is
      use Strings;

      Hex_V : String (1 .. Integer'Size / 4 + 4);
   begin
      Ada.Integer_Text_IO.Put (Hex_V, V, 16);

      declare
         Result : constant String
           := Hex_V (Fixed.Index (Hex_V, "#") + 1
                       .. Fixed.Index (Hex_V, "#", Backward) - 1);
      begin
         if Width = 0 then
            return Result;

         elsif Result'Length < Width then
            declare
               use Ada.Strings.Fixed;
               Zero : constant String := (Width - Result'Length) * '0';
            begin
               return Zero & Result;
            end;

         else
            return Result (Result'Last - Width + 1 .. Result'Last);
         end if;
      end;
   end Hex;

   ---------------

   -- Hex_Value --

   ---------------


   function Hex_Value (Hex : in String) return Natural is

      function Value (C : in Character) return Natural;
      pragma Inline (Value);
      --  Return value for single character C.


      function Value (C : in Character) return Natural is
      begin
         case C is
            when '0'       => return 0;
            when '1'       => return 1;
            when '2'       => return 2;
            when '3'       => return 3;
            when '4'       => return 4;
            when '5'       => return 5;
            when '6'       => return 6;
            when '7'       => return 7;
            when '8'       => return 8;
            when '9'       => return 9;
            when 'a' | 'A' => return 10;
            when 'b' | 'B' => return 11;
            when 'c' | 'C' => return 12;
            when 'd' | 'D' => return 13;
            when 'e' | 'E' => return 14;
            when 'f' | 'F' => return 15;
            when others    => raise Constraint_Error;
         end case;
      end Value;

      R   : Natural := 0;
      Exp : Natural := 1;

   begin
      for K in reverse Hex'Range loop
         R := R + Exp * Value (Hex (K));
         Exp := Exp * 16;
      end loop;

      return R;
   end Hex_Value;

   -----------

   -- Image --

   -----------


   function Image (N : in Natural) return String is
      N_Img : constant String := Natural'Image (N);
   begin
      return N_Img (N_Img'First + 1 .. N_Img'Last);
   end Image;

   -----------

   -- Image --

   -----------


   function Image (D : in Duration) return String is
      D_Img : constant String  := Duration'Image (D);
      K     : constant Natural := Strings.Fixed.Index (D_Img, ".");
   begin
      if K = 0 then
         return D_Img (D_Img'First + 1 .. D_Img'Last);
      else
         return D_Img (D_Img'First + 1 .. K + 2);
      end if;
   end Image;

   ---------------

   -- Is_Number --

   ---------------


   function Is_Number (S : in String) return Boolean is
      use Strings.Maps;
   begin
      return S'Length > 0
        and then Is_Subset (To_Set (S), Constants.Decimal_Digit_Set);
   end Is_Number;

   -----------

   -- Quote --

   -----------


   function Quote (Str : in String) return String is
   begin
      return '"' & Str & '"';
   end Quote;

   ------------

   -- Random --

   ------------


   function Random return Random_Integer is
   begin
      return Integer_Random.Random (Random_Generator);
   end Random;

   ------------------

   -- RW_Semaphore --

   ------------------


   protected body RW_Semaphore is

      ----------

      -- Read --

      ----------


      entry Read when W = 0 and then Write'Count = 0 is
      begin
         R := R + 1;
      end Read;

      ------------------

      -- Release_Read --

      ------------------


      procedure Release_Read is
      begin
         R := R - 1;
      end Release_Read;

      -------------------

      -- Release_Write --

      -------------------


      procedure Release_Write is
      begin
         W := W - 1;
      end Release_Write;

      -----------

      -- Write --

      -----------


      entry Write when R = 0 and then W < Writers is
      begin
         W := W + 1;
      end Write;

   end RW_Semaphore;

   ---------------

   -- Semaphore --

   ---------------


   protected body Semaphore is

      -------------

      -- Release --

      -------------


      procedure Release is
      begin
         Seized := False;
      end Release;

      -----------

      -- Seize --

      -----------


      entry Seize when not Seized is
      begin
         Seized := True;
      end Seize;

   end Semaphore;

begin
   Integer_Random.Reset (Random_Generator);
end AWS.Utils;