cannam@89: ----------------------------------------------------------------
cannam@89: --  ZLib for Ada thick binding.                               --
cannam@89: --                                                            --
cannam@89: --  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
cannam@89: --                                                            --
cannam@89: --  Open source license information is in the zlib.ads file.  --
cannam@89: ----------------------------------------------------------------
cannam@89: 
cannam@89: --  $Id: read.adb,v 1.8 2004/05/31 10:53:40 vagul Exp $
cannam@89: 
cannam@89: --  Test/demo program for the generic read interface.
cannam@89: 
cannam@89: with Ada.Numerics.Discrete_Random;
cannam@89: with Ada.Streams;
cannam@89: with Ada.Text_IO;
cannam@89: 
cannam@89: with ZLib;
cannam@89: 
cannam@89: procedure Read is
cannam@89: 
cannam@89:    use Ada.Streams;
cannam@89: 
cannam@89:    ------------------------------------
cannam@89:    --  Test configuration parameters --
cannam@89:    ------------------------------------
cannam@89: 
cannam@89:    File_Size   : Stream_Element_Offset := 100_000;
cannam@89: 
cannam@89:    Continuous  : constant Boolean          := False;
cannam@89:    --  If this constant is True, the test would be repeated again and again,
cannam@89:    --  with increment File_Size for every iteration.
cannam@89: 
cannam@89:    Header      : constant ZLib.Header_Type := ZLib.Default;
cannam@89:    --  Do not use Header other than Default in ZLib versions 1.1.4 and older.
cannam@89: 
cannam@89:    Init_Random : constant := 8;
cannam@89:    --  We are using the same random sequence, in case of we catch bug,
cannam@89:    --  so we would be able to reproduce it.
cannam@89: 
cannam@89:    -- End --
cannam@89: 
cannam@89:    Pack_Size : Stream_Element_Offset;
cannam@89:    Offset    : Stream_Element_Offset;
cannam@89: 
cannam@89:    Filter     : ZLib.Filter_Type;
cannam@89: 
cannam@89:    subtype Visible_Symbols
cannam@89:       is Stream_Element range 16#20# .. 16#7E#;
cannam@89: 
cannam@89:    package Random_Elements is new
cannam@89:       Ada.Numerics.Discrete_Random (Visible_Symbols);
cannam@89: 
cannam@89:    Gen : Random_Elements.Generator;
cannam@89:    Period  : constant Stream_Element_Offset := 200;
cannam@89:    --  Period constant variable for random generator not to be very random.
cannam@89:    --  Bigger period, harder random.
cannam@89: 
cannam@89:    Read_Buffer : Stream_Element_Array (1 .. 2048);
cannam@89:    Read_First  : Stream_Element_Offset;
cannam@89:    Read_Last   : Stream_Element_Offset;
cannam@89: 
cannam@89:    procedure Reset;
cannam@89: 
cannam@89:    procedure Read
cannam@89:      (Item : out Stream_Element_Array;
cannam@89:       Last : out Stream_Element_Offset);
cannam@89:    --  this procedure is for generic instantiation of
cannam@89:    --  ZLib.Read
cannam@89:    --  reading data from the File_In.
cannam@89: 
cannam@89:    procedure Read is new ZLib.Read
cannam@89:                            (Read,
cannam@89:                             Read_Buffer,
cannam@89:                             Rest_First => Read_First,
cannam@89:                             Rest_Last  => Read_Last);
cannam@89: 
cannam@89:    ----------
cannam@89:    -- Read --
cannam@89:    ----------
cannam@89: 
cannam@89:    procedure Read
cannam@89:      (Item : out Stream_Element_Array;
cannam@89:       Last : out Stream_Element_Offset) is
cannam@89:    begin
cannam@89:       Last := Stream_Element_Offset'Min
cannam@89:                (Item'Last,
cannam@89:                 Item'First + File_Size - Offset);
cannam@89: 
cannam@89:       for J in Item'First .. Last loop
cannam@89:          if J < Item'First + Period then
cannam@89:             Item (J) := Random_Elements.Random (Gen);
cannam@89:          else
cannam@89:             Item (J) := Item (J - Period);
cannam@89:          end if;
cannam@89: 
cannam@89:          Offset   := Offset + 1;
cannam@89:       end loop;
cannam@89:    end Read;
cannam@89: 
cannam@89:    -----------
cannam@89:    -- Reset --
cannam@89:    -----------
cannam@89: 
cannam@89:    procedure Reset is
cannam@89:    begin
cannam@89:       Random_Elements.Reset (Gen, Init_Random);
cannam@89:       Pack_Size := 0;
cannam@89:       Offset := 1;
cannam@89:       Read_First := Read_Buffer'Last + 1;
cannam@89:       Read_Last  := Read_Buffer'Last;
cannam@89:    end Reset;
cannam@89: 
cannam@89: begin
cannam@89:    Ada.Text_IO.Put_Line ("ZLib " & ZLib.Version);
cannam@89: 
cannam@89:    loop
cannam@89:       for Level in ZLib.Compression_Level'Range loop
cannam@89: 
cannam@89:          Ada.Text_IO.Put ("Level ="
cannam@89:             & ZLib.Compression_Level'Image (Level));
cannam@89: 
cannam@89:          --  Deflate using generic instantiation.
cannam@89: 
cannam@89:          ZLib.Deflate_Init
cannam@89:                (Filter,
cannam@89:                 Level,
cannam@89:                 Header => Header);
cannam@89: 
cannam@89:          Reset;
cannam@89: 
cannam@89:          Ada.Text_IO.Put
cannam@89:            (Stream_Element_Offset'Image (File_Size) & " ->");
cannam@89: 
cannam@89:          loop
cannam@89:             declare
cannam@89:                Buffer : Stream_Element_Array (1 .. 1024);
cannam@89:                Last   : Stream_Element_Offset;
cannam@89:             begin
cannam@89:                Read (Filter, Buffer, Last);
cannam@89: 
cannam@89:                Pack_Size := Pack_Size + Last - Buffer'First + 1;
cannam@89: 
cannam@89:                exit when Last < Buffer'Last;
cannam@89:             end;
cannam@89:          end loop;
cannam@89: 
cannam@89:          Ada.Text_IO.Put_Line (Stream_Element_Offset'Image (Pack_Size));
cannam@89: 
cannam@89:          ZLib.Close (Filter);
cannam@89:       end loop;
cannam@89: 
cannam@89:       exit when not Continuous;
cannam@89: 
cannam@89:       File_Size := File_Size + 1;
cannam@89:    end loop;
cannam@89: end Read;