| ------------------------------------------------------------------------------ |
| -- 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 1.26 2004/09/06 06:53:19 vagul 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 strategy 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; |
