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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;
115