------------------------------------------------------------------------------ -- ZLib for Ada thick binding. -- -- -- -- Copyright (C) 2002-2004 Dmitriy Anisimkov -- -- -- -- This library is free software; you can redistribute it and/or modify -- -- it under the terms of the GNU General Public License as published by -- -- the Free Software Foundation; either version 2 of the License, or (at -- -- your option) any later version. -- -- -- -- This library is distributed in the hope that it will be useful, but -- -- WITHOUT ANY WARRANTY; without even the implied warranty of -- -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -- -- General Public License for more details. -- -- -- -- You should have received a copy of the GNU General Public License -- -- along with this library; if not, write to the Free Software Foundation, -- -- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- ------------------------------------------------------------------------------ -- $Id: zlib.ads,v 1.2 2020/09/15 02:05:31 christos Exp $ with Ada.Streams; with Interfaces; package ZLib is ZLib_Error : exception; Status_Error : exception; type Compression_Level is new Integer range -1 .. 9; type Flush_Mode is private; type Compression_Method is private; type Window_Bits_Type is new Integer range 8 .. 15; type Memory_Level_Type is new Integer range 1 .. 9; type Unsigned_32 is new Interfaces.Unsigned_32; type Strategy_Type is private; type Header_Type is (None, Auto, Default, GZip); -- Header type usage have a some limitation for inflate. -- See comment for Inflate_Init. subtype Count is Ada.Streams.Stream_Element_Count; Default_Memory_Level : constant Memory_Level_Type := 8; Default_Window_Bits : constant Window_Bits_Type := 15; ---------------------------------- -- Compression method constants -- ---------------------------------- Deflated : constant Compression_Method; -- Only one method allowed in this ZLib version --------------------------------- -- Compression level constants -- --------------------------------- No_Compression : constant Compression_Level := 0; Best_Speed : constant Compression_Level := 1; Best_Compression : constant Compression_Level := 9; Default_Compression : constant Compression_Level := -1; -------------------------- -- Flush mode constants -- -------------------------- No_Flush : constant Flush_Mode; -- Regular way for compression, no flush Partial_Flush : constant Flush_Mode; -- Will be removed, use Z_SYNC_FLUSH instead Sync_Flush : constant Flush_Mode; -- All pending output is flushed to the output buffer and the output -- is aligned on a byte boundary, so that the decompressor can get all -- input data available so far. (In particular avail_in is zero after the -- call if enough output space has been provided before the call.) -- Flushing may degrade compression for some compression algorithms and so -- it should be used only when necessary. Block_Flush : constant Flush_Mode; -- Z_BLOCK requests that inflate() stop -- if and when it get to the next deflate block boundary. When decoding the -- zlib or gzip format, this will cause inflate() to return immediately -- after the header and before the first block. When doing a raw inflate, -- inflate() will go ahead and process the first block, and will return -- when it gets to the end of that block, or when it runs out of data. Full_Flush : constant Flush_Mode; -- All output is flushed as with SYNC_FLUSH, and the compression state -- is reset so that decompression can restart from this point if previous -- compressed data has been damaged or if random access is desired. Using -- Full_Flush too often can seriously degrade the compression. Finish : constant Flush_Mode; -- Just for tell the compressor that input data is complete. ------------------------------------ -- Compression strategy constants -- ------------------------------------ -- RLE stategy could be used only in version 1.2.0 and later. Filtered : constant Strategy_Type; Huffman_Only : constant Strategy_Type; RLE : constant Strategy_Type; Default_Strategy : constant Strategy_Type; Default_Buffer_Size : constant := 4096; type Filter_Type is tagged limited private; -- The filter is for compression and for decompression. -- The usage of the type is depend of its initialization. function Version return String; pragma Inline (Version); -- Return string representation of the ZLib version. procedure Deflate_Init (Filter : in out Filter_Type; Level : in Compression_Level := Default_Compression; Strategy : in Strategy_Type := Default_Strategy; Method : in Compression_Method := Deflated; Window_Bits : in Window_Bits_Type := Default_Window_Bits; Memory_Level : in Memory_Level_Type := Default_Memory_Level; Header : in Header_Type := Default); -- Compressor initialization. -- When Header parameter is Auto or Default, then default zlib header -- would be provided for compressed data. -- When Header is GZip, then gzip header would be set instead of -- default header. -- When Header is None, no header would be set for compressed data. procedure Inflate_Init (Filter : in out Filter_Type; Window_Bits : in Window_Bits_Type := Default_Window_Bits; Header : in Header_Type := Default); -- Decompressor initialization. -- Default header type mean that ZLib default header is expecting in the -- input compressed stream. -- Header type None mean that no header is expecting in the input stream. -- GZip header type mean that GZip header is expecting in the -- input compressed stream. -- Auto header type mean that header type (GZip or Native) would be -- detected automatically in the input stream. -- Note that header types parameter values None, GZip and Auto are -- supported for inflate routine only in ZLib versions 1.2.0.2 and later. -- Deflate_Init is supporting all header types. function Is_Open (Filter : in Filter_Type) return Boolean; pragma Inline (Is_Open); -- Is the filter opened for compression or decompression. procedure Close (Filter : in out Filter_Type; Ignore_Error : in Boolean := False); -- Closing the compression or decompressor. -- If stream is closing before the complete and Ignore_Error is False, -- The exception would be raised. generic with procedure Data_In (Item : out Ada.Streams.Stream_Element_Array; Last : out Ada.Streams.Stream_Element_Offset); with procedure Data_Out (Item : in Ada.Streams.Stream_Element_Array); procedure Generic_Translate (Filter : in out Filter_Type; In_Buffer_Size : in Integer := Default_Buffer_Size; Out_Buffer_Size : in Integer := Default_Buffer_Size); -- Compress/decompress data fetch from Data_In routine and pass the result -- to the Data_Out routine. User should provide Data_In and Data_Out -- for compression/decompression data flow. -- Compression or decompression depend on Filter initialization. function Total_In (Filter : in Filter_Type) return Count; pragma Inline (Total_In); -- Returns total number of input bytes read so far function Total_Out (Filter : in Filter_Type) return Count; pragma Inline (Total_Out); -- Returns total number of bytes output so far function CRC32 (CRC : in Unsigned_32; Data : in Ada.Streams.Stream_Element_Array) return Unsigned_32; pragma Inline (CRC32); -- Compute CRC32, it could be necessary for make gzip format procedure CRC32 (CRC : in out Unsigned_32; Data : in Ada.Streams.Stream_Element_Array); pragma Inline (CRC32); -- Compute CRC32, it could be necessary for make gzip format ------------------------------------------------- -- Below is more complex low level routines. -- ------------------------------------------------- procedure Translate (Filter : in out Filter_Type; In_Data : in Ada.Streams.Stream_Element_Array; In_Last : out Ada.Streams.Stream_Element_Offset; Out_Data : out Ada.Streams.Stream_Element_Array; Out_Last : out Ada.Streams.Stream_Element_Offset; Flush : in Flush_Mode); -- Compress/decompress the In_Data buffer and place the result into -- Out_Data. In_Last is the index of last element from In_Data accepted by -- the Filter. Out_Last is the last element of the received data from -- Filter. To tell the filter that incoming data are complete put the -- Flush parameter to Finish. function Stream_End (Filter : in Filter_Type) return Boolean; pragma Inline (Stream_End); -- Return the true when the stream is complete. procedure Flush (Filter : in out Filter_Type; Out_Data : out Ada.Streams.Stream_Element_Array; Out_Last : out Ada.Streams.Stream_Element_Offset; Flush : in Flush_Mode); pragma Inline (Flush); -- Flushing the data from the compressor. generic with procedure Write (Item : in Ada.Streams.Stream_Element_Array); -- User should provide this routine for accept -- compressed/decompressed data. Buffer_Size : in Ada.Streams.Stream_Element_Offset := Default_Buffer_Size; -- Buffer size for Write user routine. procedure Write (Filter : in out Filter_Type; Item : in Ada.Streams.Stream_Element_Array; Flush : in Flush_Mode := No_Flush); -- Compress/Decompress data from Item to the generic parameter procedure -- Write. Output buffer size could be set in Buffer_Size generic parameter. generic with procedure Read (Item : out Ada.Streams.Stream_Element_Array; Last : out Ada.Streams.Stream_Element_Offset); -- User should provide data for compression/decompression -- thru this routine. Buffer : in out Ada.Streams.Stream_Element_Array; -- Buffer for keep remaining data from the previous -- back read. Rest_First, Rest_Last : in out Ada.Streams.Stream_Element_Offset; -- Rest_First have to be initialized to Buffer'Last + 1 -- Rest_Last have to be initialized to Buffer'Last -- before usage. Allow_Read_Some : in Boolean := False; -- Is it allowed to return Last < Item'Last before end of data. procedure Read (Filter : in out Filter_Type; Item : out Ada.Streams.Stream_Element_Array; Last : out Ada.Streams.Stream_Element_Offset; Flush : in Flush_Mode := No_Flush); -- Compress/Decompress data from generic parameter procedure Read to the -- Item. User should provide Buffer and initialized Rest_First, Rest_Last -- indicators. If Allow_Read_Some is True, Read routines could return -- Last < Item'Last only at end of stream. private use Ada.Streams; pragma Assert (Ada.Streams.Stream_Element'Size = 8); pragma Assert (Ada.Streams.Stream_Element'Modulus = 2**8); type Flush_Mode is new Integer range 0 .. 5; type Compression_Method is new Integer range 8 .. 8; type Strategy_Type is new Integer range 0 .. 3; No_Flush : constant Flush_Mode := 0; Partial_Flush : constant Flush_Mode := 1; Sync_Flush : constant Flush_Mode := 2; Full_Flush : constant Flush_Mode := 3; Finish : constant Flush_Mode := 4; Block_Flush : constant Flush_Mode := 5; Filtered : constant Strategy_Type := 1; Huffman_Only : constant Strategy_Type := 2; RLE : constant Strategy_Type := 3; Default_Strategy : constant Strategy_Type := 0; Deflated : constant Compression_Method := 8; type Z_Stream; type Z_Stream_Access is access all Z_Stream; type Filter_Type is tagged limited record Strm : Z_Stream_Access; Compression : Boolean; Stream_End : Boolean; Header : Header_Type; CRC : Unsigned_32; Offset : Stream_Element_Offset; -- Offset for gzip header/footer output. end record; end ZLib;