1----------------------------------------------------------------
  2--  ZLib for Ada thick binding.                               --
  3--                                                            --
  4--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
  5--                                                            --
  6--  Open source license information is in the zlib.ads file.  --
  7----------------------------------------------------------------
  8
  9--  $Id: zlib-streams.ads,v 1.12 2004/05/31 10:53:40 vagul Exp $
 10
 11package ZLib.Streams is
 12
 13   type Stream_Mode is (In_Stream, Out_Stream, Duplex);
 14
 15   type Stream_Access is access all Ada.Streams.Root_Stream_Type'Class;
 16
 17   type Stream_Type is
 18      new Ada.Streams.Root_Stream_Type with private;
 19
 20   procedure Read
 21     (Stream : in out Stream_Type;
 22      Item   :    out Ada.Streams.Stream_Element_Array;
 23      Last   :    out Ada.Streams.Stream_Element_Offset);
 24
 25   procedure Write
 26     (Stream : in out Stream_Type;
 27      Item   : in     Ada.Streams.Stream_Element_Array);
 28
 29   procedure Flush
 30     (Stream : in out Stream_Type;
 31      Mode   : in     Flush_Mode := Sync_Flush);
 32   --  Flush the written data to the back stream,
 33   --  all data placed to the compressor is flushing to the Back stream.
 34   --  Should not be used untill necessary, becouse it is decreasing
 35   --  compression.
 36
 37   function Read_Total_In (Stream : in Stream_Type) return Count;
 38   pragma Inline (Read_Total_In);
 39   --  Return total number of bytes read from back stream so far.
 40
 41   function Read_Total_Out (Stream : in Stream_Type) return Count;
 42   pragma Inline (Read_Total_Out);
 43   --  Return total number of bytes read so far.
 44
 45   function Write_Total_In (Stream : in Stream_Type) return Count;
 46   pragma Inline (Write_Total_In);
 47   --  Return total number of bytes written so far.
 48
 49   function Write_Total_Out (Stream : in Stream_Type) return Count;
 50   pragma Inline (Write_Total_Out);
 51   --  Return total number of bytes written to the back stream.
 52
 53   procedure Create
 54     (Stream            :    out Stream_Type;
 55      Mode              : in     Stream_Mode;
 56      Back              : in     Stream_Access;
 57      Back_Compressed   : in     Boolean;
 58      Level             : in     Compression_Level := Default_Compression;
 59      Strategy          : in     Strategy_Type     := Default_Strategy;
 60      Header            : in     Header_Type       := Default;
 61      Read_Buffer_Size  : in     Ada.Streams.Stream_Element_Offset
 62                                    := Default_Buffer_Size;
 63      Write_Buffer_Size : in     Ada.Streams.Stream_Element_Offset
 64                                    := Default_Buffer_Size);
 65   --  Create the Comression/Decompression stream.
 66   --  If mode is In_Stream then Write operation is disabled.
 67   --  If mode is Out_Stream then Read operation is disabled.
 68
 69   --  If Back_Compressed is true then
 70   --  Data written to the Stream is compressing to the Back stream
 71   --  and data read from the Stream is decompressed data from the Back stream.
 72
 73   --  If Back_Compressed is false then
 74   --  Data written to the Stream is decompressing to the Back stream
 75   --  and data read from the Stream is compressed data from the Back stream.
 76
 77   --  !!! When the Need_Header is False ZLib-Ada is using undocumented
 78   --  ZLib 1.1.4 functionality to do not create/wait for ZLib headers.
 79
 80   function Is_Open (Stream : Stream_Type) return Boolean;
 81
 82   procedure Close (Stream : in out Stream_Type);
 83
 84private
 85
 86   use Ada.Streams;
 87
 88   type Buffer_Access is access all Stream_Element_Array;
 89
 90   type Stream_Type
 91     is new Root_Stream_Type with
 92   record
 93      Mode       : Stream_Mode;
 94
 95      Buffer     : Buffer_Access;
 96      Rest_First : Stream_Element_Offset;
 97      Rest_Last  : Stream_Element_Offset;
 98      --  Buffer for Read operation.
 99      --  We need to have this buffer in the record
100      --  becouse not all read data from back stream
101      --  could be processed during the read operation.
102
103      Buffer_Size : Stream_Element_Offset;
104      --  Buffer size for write operation.
105      --  We do not need to have this buffer
106      --  in the record becouse all data could be
107      --  processed in the write operation.
108
109      Back       : Stream_Access;
110      Reader     : Filter_Type;
111      Writer     : Filter_Type;
112   end record;
113
114end ZLib.Streams;