---------------------------------------------------------------- -- 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 1.1.1.2 2016/07/28 12:20:05 christos 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;