symbian-qemu-0.9.1-12/zlib-1.2.3/contrib/ada/read.adb
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/zlib-1.2.3/contrib/ada/read.adb	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,156 @@
+----------------------------------------------------------------
+--  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;