furnace/extern/zlib/contrib/ada/zlib-streams.ads
2021-05-28 15:25:55 -05:00

114 lines
4.2 KiB
Ada

----------------------------------------------------------------
-- ZLib for Ada thick binding. --
-- --
-- Copyright (C) 2002-2003 Dmitriy Anisimkov --
-- --
-- Open source license information is in the zlib.ads file. --
----------------------------------------------------------------
-- $Id: zlib-streams.ads,v 1.12 2004/05/31 10:53:40 vagul Exp $
package ZLib.Streams is
type Stream_Mode is (In_Stream, Out_Stream, Duplex);
type Stream_Access is access all Ada.Streams.Root_Stream_Type'Class;
type Stream_Type is
new Ada.Streams.Root_Stream_Type with private;
procedure Read
(Stream : in out Stream_Type;
Item : out Ada.Streams.Stream_Element_Array;
Last : out Ada.Streams.Stream_Element_Offset);
procedure Write
(Stream : in out Stream_Type;
Item : in Ada.Streams.Stream_Element_Array);
procedure Flush
(Stream : in out Stream_Type;
Mode : in Flush_Mode := Sync_Flush);
-- Flush the written data to the back stream,
-- all data placed to the compressor is flushing to the Back stream.
-- Should not be used until necessary, because it is decreasing
-- compression.
function Read_Total_In (Stream : in Stream_Type) return Count;
pragma Inline (Read_Total_In);
-- Return total number of bytes read from back stream so far.
function Read_Total_Out (Stream : in Stream_Type) return Count;
pragma Inline (Read_Total_Out);
-- Return total number of bytes read so far.
function Write_Total_In (Stream : in Stream_Type) return Count;
pragma Inline (Write_Total_In);
-- Return total number of bytes written so far.
function Write_Total_Out (Stream : in Stream_Type) return Count;
pragma Inline (Write_Total_Out);
-- Return total number of bytes written to the back stream.
procedure Create
(Stream : out Stream_Type;
Mode : in Stream_Mode;
Back : in Stream_Access;
Back_Compressed : in Boolean;
Level : in Compression_Level := Default_Compression;
Strategy : in Strategy_Type := Default_Strategy;
Header : in Header_Type := Default;
Read_Buffer_Size : in Ada.Streams.Stream_Element_Offset
:= Default_Buffer_Size;
Write_Buffer_Size : in Ada.Streams.Stream_Element_Offset
:= Default_Buffer_Size);
-- Create the Comression/Decompression stream.
-- If mode is In_Stream then Write operation is disabled.
-- If mode is Out_Stream then Read operation is disabled.
-- If Back_Compressed is true then
-- Data written to the Stream is compressing to the Back stream
-- and data read from the Stream is decompressed data from the Back stream.
-- If Back_Compressed is false then
-- Data written to the Stream is decompressing to the Back stream
-- and data read from the Stream is compressed data from the Back stream.
-- !!! When the Need_Header is False ZLib-Ada is using undocumented
-- ZLib 1.1.4 functionality to do not create/wait for ZLib headers.
function Is_Open (Stream : Stream_Type) return Boolean;
procedure Close (Stream : in out Stream_Type);
private
use Ada.Streams;
type Buffer_Access is access all Stream_Element_Array;
type Stream_Type
is new Root_Stream_Type with
record
Mode : Stream_Mode;
Buffer : Buffer_Access;
Rest_First : Stream_Element_Offset;
Rest_Last : Stream_Element_Offset;
-- Buffer for Read operation.
-- We need to have this buffer in the record
-- because not all read data from back stream
-- could be processed during the read operation.
Buffer_Size : Stream_Element_Offset;
-- Buffer size for write operation.
-- We do not need to have this buffer
-- in the record because all data could be
-- processed in the write operation.
Back : Stream_Access;
Reader : Filter_Type;
Writer : Filter_Type;
end record;
end ZLib.Streams;