Chris@4: ----------------------------------------------------------------
Chris@4: --  ZLib for Ada thick binding.                               --
Chris@4: --                                                            --
Chris@4: --  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
Chris@4: --                                                            --
Chris@4: --  Open source license information is in the zlib.ads file.  --
Chris@4: ----------------------------------------------------------------
Chris@4: 
Chris@4: --  $Id: read.adb,v 1.8 2004/05/31 10:53:40 vagul Exp $
Chris@4: 
Chris@4: --  Test/demo program for the generic read interface.
Chris@4: 
Chris@4: with Ada.Numerics.Discrete_Random;
Chris@4: with Ada.Streams;
Chris@4: with Ada.Text_IO;
Chris@4: 
Chris@4: with ZLib;
Chris@4: 
Chris@4: procedure Read is
Chris@4: 
Chris@4:    use Ada.Streams;
Chris@4: 
Chris@4:    ------------------------------------
Chris@4:    --  Test configuration parameters --
Chris@4:    ------------------------------------
Chris@4: 
Chris@4:    File_Size   : Stream_Element_Offset := 100_000;
Chris@4: 
Chris@4:    Continuous  : constant Boolean          := False;
Chris@4:    --  If this constant is True, the test would be repeated again and again,
Chris@4:    --  with increment File_Size for every iteration.
Chris@4: 
Chris@4:    Header      : constant ZLib.Header_Type := ZLib.Default;
Chris@4:    --  Do not use Header other than Default in ZLib versions 1.1.4 and older.
Chris@4: 
Chris@4:    Init_Random : constant := 8;
Chris@4:    --  We are using the same random sequence, in case of we catch bug,
Chris@4:    --  so we would be able to reproduce it.
Chris@4: 
Chris@4:    -- End --
Chris@4: 
Chris@4:    Pack_Size : Stream_Element_Offset;
Chris@4:    Offset    : Stream_Element_Offset;
Chris@4: 
Chris@4:    Filter     : ZLib.Filter_Type;
Chris@4: 
Chris@4:    subtype Visible_Symbols
Chris@4:       is Stream_Element range 16#20# .. 16#7E#;
Chris@4: 
Chris@4:    package Random_Elements is new
Chris@4:       Ada.Numerics.Discrete_Random (Visible_Symbols);
Chris@4: 
Chris@4:    Gen : Random_Elements.Generator;
Chris@4:    Period  : constant Stream_Element_Offset := 200;
Chris@4:    --  Period constant variable for random generator not to be very random.
Chris@4:    --  Bigger period, harder random.
Chris@4: 
Chris@4:    Read_Buffer : Stream_Element_Array (1 .. 2048);
Chris@4:    Read_First  : Stream_Element_Offset;
Chris@4:    Read_Last   : Stream_Element_Offset;
Chris@4: 
Chris@4:    procedure Reset;
Chris@4: 
Chris@4:    procedure Read
Chris@4:      (Item : out Stream_Element_Array;
Chris@4:       Last : out Stream_Element_Offset);
Chris@4:    --  this procedure is for generic instantiation of
Chris@4:    --  ZLib.Read
Chris@4:    --  reading data from the File_In.
Chris@4: 
Chris@4:    procedure Read is new ZLib.Read
Chris@4:                            (Read,
Chris@4:                             Read_Buffer,
Chris@4:                             Rest_First => Read_First,
Chris@4:                             Rest_Last  => Read_Last);
Chris@4: 
Chris@4:    ----------
Chris@4:    -- Read --
Chris@4:    ----------
Chris@4: 
Chris@4:    procedure Read
Chris@4:      (Item : out Stream_Element_Array;
Chris@4:       Last : out Stream_Element_Offset) is
Chris@4:    begin
Chris@4:       Last := Stream_Element_Offset'Min
Chris@4:                (Item'Last,
Chris@4:                 Item'First + File_Size - Offset);
Chris@4: 
Chris@4:       for J in Item'First .. Last loop
Chris@4:          if J < Item'First + Period then
Chris@4:             Item (J) := Random_Elements.Random (Gen);
Chris@4:          else
Chris@4:             Item (J) := Item (J - Period);
Chris@4:          end if;
Chris@4: 
Chris@4:          Offset   := Offset + 1;
Chris@4:       end loop;
Chris@4:    end Read;
Chris@4: 
Chris@4:    -----------
Chris@4:    -- Reset --
Chris@4:    -----------
Chris@4: 
Chris@4:    procedure Reset is
Chris@4:    begin
Chris@4:       Random_Elements.Reset (Gen, Init_Random);
Chris@4:       Pack_Size := 0;
Chris@4:       Offset := 1;
Chris@4:       Read_First := Read_Buffer'Last + 1;
Chris@4:       Read_Last  := Read_Buffer'Last;
Chris@4:    end Reset;
Chris@4: 
Chris@4: begin
Chris@4:    Ada.Text_IO.Put_Line ("ZLib " & ZLib.Version);
Chris@4: 
Chris@4:    loop
Chris@4:       for Level in ZLib.Compression_Level'Range loop
Chris@4: 
Chris@4:          Ada.Text_IO.Put ("Level ="
Chris@4:             & ZLib.Compression_Level'Image (Level));
Chris@4: 
Chris@4:          --  Deflate using generic instantiation.
Chris@4: 
Chris@4:          ZLib.Deflate_Init
Chris@4:                (Filter,
Chris@4:                 Level,
Chris@4:                 Header => Header);
Chris@4: 
Chris@4:          Reset;
Chris@4: 
Chris@4:          Ada.Text_IO.Put
Chris@4:            (Stream_Element_Offset'Image (File_Size) & " ->");
Chris@4: 
Chris@4:          loop
Chris@4:             declare
Chris@4:                Buffer : Stream_Element_Array (1 .. 1024);
Chris@4:                Last   : Stream_Element_Offset;
Chris@4:             begin
Chris@4:                Read (Filter, Buffer, Last);
Chris@4: 
Chris@4:                Pack_Size := Pack_Size + Last - Buffer'First + 1;
Chris@4: 
Chris@4:                exit when Last < Buffer'Last;
Chris@4:             end;
Chris@4:          end loop;
Chris@4: 
Chris@4:          Ada.Text_IO.Put_Line (Stream_Element_Offset'Image (Pack_Size));
Chris@4: 
Chris@4:          ZLib.Close (Filter);
Chris@4:       end loop;
Chris@4: 
Chris@4:       exit when not Continuous;
Chris@4: 
Chris@4:       File_Size := File_Size + 1;
Chris@4:    end loop;
Chris@4: end Read;