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

-- ZLib for Ada thick binding. --

-- --

-- Copyright (C) 2002-2003 Dmitriy Anisimkov --

-- --

-- Open source license information is in the zlib.ads file. --

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

-- $Id: read.adb,v 1.8 2004/05/31 10:53:40 vagul Exp $

-- Test/demo program for the generic read interface.

with Ada.Numerics.Discrete_Random;

with Ada.Streams;

with Ada.Text_IO;

with ZLib;

procedure Read is

use Ada.Streams;

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

-- Test configuration parameters --

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

File_Size : Stream_Element_Offset := 100_000;

Continuous : constant Boolean := False;

-- If this constant is True, the test would be repeated again and again,

-- with increment File_Size for every iteration.

Header : constant ZLib.Header_Type := ZLib.Default;

-- Do not use Header other than Default in ZLib versions 1.1.4 and older.

Init_Random : constant := 8;

-- We are using the same random sequence, in case of we catch bug,

-- so we would be able to reproduce it.

-- End --

Pack_Size : Stream_Element_Offset;

Offset : Stream_Element_Offset;

Filter : ZLib.Filter_Type;

subtype Visible_Symbols

is Stream_Element range 16#20# .. 16#7E#;

package Random_Elements is new

Ada.Numerics.Discrete_Random (Visible_Symbols);

Gen : Random_Elements.Generator;

Period : constant Stream_Element_Offset := 200;

-- Period constant variable for random generator not to be very random.

-- Bigger period, harder random.

Read_Buffer : Stream_Element_Array (1 .. 2048);

Read_First : Stream_Element_Offset;

Read_Last : Stream_Element_Offset;

procedure Reset;

procedure Read

(Item : out Stream_Element_Array;

Last : out Stream_Element_Offset);

-- this procedure is for generic instantiation of

-- ZLib.Read

-- reading data from the File_In.

procedure Read is new ZLib.Read

(Read,

Read_Buffer,

Rest_First => Read_First,

Rest_Last => Read_Last);

----------

-- Read --

----------

procedure Read

(Item : out Stream_Element_Array;

Last : out Stream_Element_Offset) is

begin

Last := Stream_Element_Offset'Min

(Item'Last,

Item'First + File_Size - Offset);

for J in Item'First .. Last loop

if J < Item'First + Period then

Item (J) := Random_Elements.Random (Gen);

else

Item (J) := Item (J - Period);

end if;

Offset := Offset + 1;

end loop;

end Read;

-----------

-- Reset --

-----------

procedure Reset is

begin

Random_Elements.Reset (Gen, Init_Random);

Pack_Size := 0;

Offset := 1;

Read_First := Read_Buffer'Last + 1;

Read_Last := Read_Buffer'Last;

end Reset;

begin

Ada.Text_IO.Put_Line ("ZLib " & ZLib.Version);

loop

for Level in ZLib.Compression_Level'Range loop

Ada.Text_IO.Put ("Level ="

& ZLib.Compression_Level'Image (Level));

-- Deflate using generic instantiation.

ZLib.Deflate_Init

(Filter,

Level,

Header => Header);

Reset;

Ada.Text_IO.Put

(Stream_Element_Offset'Image (File_Size) & " ->");

loop

declare

Buffer : Stream_Element_Array (1 .. 1024);

Last : Stream_Element_Offset;

begin

Read (Filter, Buffer, Last);

Pack_Size := Pack_Size + Last - Buffer'First + 1;

exit when Last < Buffer'Last;

end;

end loop;

Ada.Text_IO.Put_Line (Stream_Element_Offset'Image (Pack_Size));

ZLib.Close (Filter);

end loop;

exit when not Continuous;

File_Size := File_Size + 1;

end loop;

end Read;