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1 | ------------------------------------------------------------------------------ |
2 | -- ZLib for Ada thick binding. -- | |
3 | -- -- | |
4 | -- Copyright (C) 2002-2004 Dmitriy Anisimkov -- | |
5 | -- -- | |
6 | -- This library is free software; you can redistribute it and/or modify -- | |
7 | -- it under the terms of the GNU General Public License as published by -- | |
8 | -- the Free Software Foundation; either version 2 of the License, or (at -- | |
9 | -- your option) any later version. -- | |
10 | -- -- | |
11 | -- This library is distributed in the hope that it will be useful, but -- | |
12 | -- WITHOUT ANY WARRANTY; without even the implied warranty of -- | |
13 | -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -- | |
14 | -- General Public License for more details. -- | |
15 | -- -- | |
16 | -- You should have received a copy of the GNU General Public License -- | |
17 | -- along with this library; if not, write to the Free Software Foundation, -- | |
18 | -- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. -- | |
19 | -- -- | |
20 | -- As a special exception, if other files instantiate generics from this -- | |
21 | -- unit, or you link this unit with other files to produce an executable, -- | |
22 | -- this unit does not by itself cause the resulting executable to be -- | |
23 | -- covered by the GNU General Public License. This exception does not -- | |
24 | -- however invalidate any other reasons why the executable file might be -- | |
25 | -- covered by the GNU Public License. -- | |
26 | ------------------------------------------------------------------------------ | |
27 | ||
28 | -- $Id: zlib.ads,v 1.26 2004/09/06 06:53:19 vagul Exp $ | |
29 | ||
30 | with Ada.Streams; | |
31 | ||
32 | with Interfaces; | |
33 | ||
34 | package ZLib is | |
35 | ||
36 | ZLib_Error : exception; | |
37 | Status_Error : exception; | |
38 | ||
39 | type Compression_Level is new Integer range -1 .. 9; | |
40 | ||
41 | type Flush_Mode is private; | |
42 | ||
43 | type Compression_Method is private; | |
44 | ||
45 | type Window_Bits_Type is new Integer range 8 .. 15; | |
46 | ||
47 | type Memory_Level_Type is new Integer range 1 .. 9; | |
48 | ||
49 | type Unsigned_32 is new Interfaces.Unsigned_32; | |
50 | ||
51 | type Strategy_Type is private; | |
52 | ||
53 | type Header_Type is (None, Auto, Default, GZip); | |
54 | -- Header type usage have a some limitation for inflate. | |
55 | -- See comment for Inflate_Init. | |
56 | ||
57 | subtype Count is Ada.Streams.Stream_Element_Count; | |
58 | ||
59 | Default_Memory_Level : constant Memory_Level_Type := 8; | |
60 | Default_Window_Bits : constant Window_Bits_Type := 15; | |
61 | ||
62 | ---------------------------------- | |
63 | -- Compression method constants -- | |
64 | ---------------------------------- | |
65 | ||
66 | Deflated : constant Compression_Method; | |
67 | -- Only one method allowed in this ZLib version | |
68 | ||
69 | --------------------------------- | |
70 | -- Compression level constants -- | |
71 | --------------------------------- | |
72 | ||
73 | No_Compression : constant Compression_Level := 0; | |
74 | Best_Speed : constant Compression_Level := 1; | |
75 | Best_Compression : constant Compression_Level := 9; | |
76 | Default_Compression : constant Compression_Level := -1; | |
77 | ||
78 | -------------------------- | |
79 | -- Flush mode constants -- | |
80 | -------------------------- | |
81 | ||
82 | No_Flush : constant Flush_Mode; | |
83 | -- Regular way for compression, no flush | |
84 | ||
85 | Partial_Flush : constant Flush_Mode; | |
86 | -- Will be removed, use Z_SYNC_FLUSH instead | |
87 | ||
88 | Sync_Flush : constant Flush_Mode; | |
89 | -- All pending output is flushed to the output buffer and the output | |
90 | -- is aligned on a byte boundary, so that the decompressor can get all | |
91 | -- input data available so far. (In particular avail_in is zero after the | |
92 | -- call if enough output space has been provided before the call.) | |
93 | -- Flushing may degrade compression for some compression algorithms and so | |
94 | -- it should be used only when necessary. | |
95 | ||
96 | Block_Flush : constant Flush_Mode; | |
97 | -- Z_BLOCK requests that inflate() stop | |
98 | -- if and when it get to the next deflate block boundary. When decoding the | |
99 | -- zlib or gzip format, this will cause inflate() to return immediately | |
100 | -- after the header and before the first block. When doing a raw inflate, | |
101 | -- inflate() will go ahead and process the first block, and will return | |
102 | -- when it gets to the end of that block, or when it runs out of data. | |
103 | ||
104 | Full_Flush : constant Flush_Mode; | |
105 | -- All output is flushed as with SYNC_FLUSH, and the compression state | |
106 | -- is reset so that decompression can restart from this point if previous | |
107 | -- compressed data has been damaged or if random access is desired. Using | |
108 | -- Full_Flush too often can seriously degrade the compression. | |
109 | ||
110 | Finish : constant Flush_Mode; | |
111 | -- Just for tell the compressor that input data is complete. | |
112 | ||
113 | ------------------------------------ | |
114 | -- Compression strategy constants -- | |
115 | ------------------------------------ | |
116 | ||
117 | -- RLE stategy could be used only in version 1.2.0 and later. | |
118 | ||
119 | Filtered : constant Strategy_Type; | |
120 | Huffman_Only : constant Strategy_Type; | |
121 | RLE : constant Strategy_Type; | |
122 | Default_Strategy : constant Strategy_Type; | |
123 | ||
124 | Default_Buffer_Size : constant := 4096; | |
125 | ||
126 | type Filter_Type is tagged limited private; | |
127 | -- The filter is for compression and for decompression. | |
128 | -- The usage of the type is depend of its initialization. | |
129 | ||
130 | function Version return String; | |
131 | pragma Inline (Version); | |
132 | -- Return string representation of the ZLib version. | |
133 | ||
134 | procedure Deflate_Init | |
135 | (Filter : in out Filter_Type; | |
136 | Level : in Compression_Level := Default_Compression; | |
137 | Strategy : in Strategy_Type := Default_Strategy; | |
138 | Method : in Compression_Method := Deflated; | |
139 | Window_Bits : in Window_Bits_Type := Default_Window_Bits; | |
140 | Memory_Level : in Memory_Level_Type := Default_Memory_Level; | |
141 | Header : in Header_Type := Default); | |
142 | -- Compressor initialization. | |
143 | -- When Header parameter is Auto or Default, then default zlib header | |
144 | -- would be provided for compressed data. | |
145 | -- When Header is GZip, then gzip header would be set instead of | |
146 | -- default header. | |
147 | -- When Header is None, no header would be set for compressed data. | |
148 | ||
149 | procedure Inflate_Init | |
150 | (Filter : in out Filter_Type; | |
151 | Window_Bits : in Window_Bits_Type := Default_Window_Bits; | |
152 | Header : in Header_Type := Default); | |
153 | -- Decompressor initialization. | |
154 | -- Default header type mean that ZLib default header is expecting in the | |
155 | -- input compressed stream. | |
156 | -- Header type None mean that no header is expecting in the input stream. | |
157 | -- GZip header type mean that GZip header is expecting in the | |
158 | -- input compressed stream. | |
159 | -- Auto header type mean that header type (GZip or Native) would be | |
160 | -- detected automatically in the input stream. | |
161 | -- Note that header types parameter values None, GZip and Auto are | |
162 | -- supported for inflate routine only in ZLib versions 1.2.0.2 and later. | |
163 | -- Deflate_Init is supporting all header types. | |
164 | ||
165 | function Is_Open (Filter : in Filter_Type) return Boolean; | |
166 | pragma Inline (Is_Open); | |
167 | -- Is the filter opened for compression or decompression. | |
168 | ||
169 | procedure Close | |
170 | (Filter : in out Filter_Type; | |
171 | Ignore_Error : in Boolean := False); | |
172 | -- Closing the compression or decompressor. | |
173 | -- If stream is closing before the complete and Ignore_Error is False, | |
174 | -- The exception would be raised. | |
175 | ||
176 | generic | |
177 | with procedure Data_In | |
178 | (Item : out Ada.Streams.Stream_Element_Array; | |
179 | Last : out Ada.Streams.Stream_Element_Offset); | |
180 | with procedure Data_Out | |
181 | (Item : in Ada.Streams.Stream_Element_Array); | |
182 | procedure Generic_Translate | |
183 | (Filter : in out Filter_Type; | |
184 | In_Buffer_Size : in Integer := Default_Buffer_Size; | |
185 | Out_Buffer_Size : in Integer := Default_Buffer_Size); | |
186 | -- Compress/decompress data fetch from Data_In routine and pass the result | |
187 | -- to the Data_Out routine. User should provide Data_In and Data_Out | |
188 | -- for compression/decompression data flow. | |
189 | -- Compression or decompression depend on Filter initialization. | |
190 | ||
191 | function Total_In (Filter : in Filter_Type) return Count; | |
192 | pragma Inline (Total_In); | |
193 | -- Returns total number of input bytes read so far | |
194 | ||
195 | function Total_Out (Filter : in Filter_Type) return Count; | |
196 | pragma Inline (Total_Out); | |
197 | -- Returns total number of bytes output so far | |
198 | ||
199 | function CRC32 | |
200 | (CRC : in Unsigned_32; | |
201 | Data : in Ada.Streams.Stream_Element_Array) | |
202 | return Unsigned_32; | |
203 | pragma Inline (CRC32); | |
204 | -- Compute CRC32, it could be necessary for make gzip format | |
205 | ||
206 | procedure CRC32 | |
207 | (CRC : in out Unsigned_32; | |
208 | Data : in Ada.Streams.Stream_Element_Array); | |
209 | pragma Inline (CRC32); | |
210 | -- Compute CRC32, it could be necessary for make gzip format | |
211 | ||
212 | ------------------------------------------------- | |
213 | -- Below is more complex low level routines. -- | |
214 | ------------------------------------------------- | |
215 | ||
216 | procedure Translate | |
217 | (Filter : in out Filter_Type; | |
218 | In_Data : in Ada.Streams.Stream_Element_Array; | |
219 | In_Last : out Ada.Streams.Stream_Element_Offset; | |
220 | Out_Data : out Ada.Streams.Stream_Element_Array; | |
221 | Out_Last : out Ada.Streams.Stream_Element_Offset; | |
222 | Flush : in Flush_Mode); | |
223 | -- Compress/decompress the In_Data buffer and place the result into | |
224 | -- Out_Data. In_Last is the index of last element from In_Data accepted by | |
225 | -- the Filter. Out_Last is the last element of the received data from | |
226 | -- Filter. To tell the filter that incoming data are complete put the | |
227 | -- Flush parameter to Finish. | |
228 | ||
229 | function Stream_End (Filter : in Filter_Type) return Boolean; | |
230 | pragma Inline (Stream_End); | |
231 | -- Return the true when the stream is complete. | |
232 | ||
233 | procedure Flush | |
234 | (Filter : in out Filter_Type; | |
235 | Out_Data : out Ada.Streams.Stream_Element_Array; | |
236 | Out_Last : out Ada.Streams.Stream_Element_Offset; | |
237 | Flush : in Flush_Mode); | |
238 | pragma Inline (Flush); | |
239 | -- Flushing the data from the compressor. | |
240 | ||
241 | generic | |
242 | with procedure Write | |
243 | (Item : in Ada.Streams.Stream_Element_Array); | |
244 | -- User should provide this routine for accept | |
245 | -- compressed/decompressed data. | |
246 | ||
247 | Buffer_Size : in Ada.Streams.Stream_Element_Offset | |
248 | := Default_Buffer_Size; | |
249 | -- Buffer size for Write user routine. | |
250 | ||
251 | procedure Write | |
252 | (Filter : in out Filter_Type; | |
253 | Item : in Ada.Streams.Stream_Element_Array; | |
254 | Flush : in Flush_Mode := No_Flush); | |
255 | -- Compress/Decompress data from Item to the generic parameter procedure | |
256 | -- Write. Output buffer size could be set in Buffer_Size generic parameter. | |
257 | ||
258 | generic | |
259 | with procedure Read | |
260 | (Item : out Ada.Streams.Stream_Element_Array; | |
261 | Last : out Ada.Streams.Stream_Element_Offset); | |
262 | -- User should provide data for compression/decompression | |
263 | -- thru this routine. | |
264 | ||
265 | Buffer : in out Ada.Streams.Stream_Element_Array; | |
266 | -- Buffer for keep remaining data from the previous | |
267 | -- back read. | |
268 | ||
269 | Rest_First, Rest_Last : in out Ada.Streams.Stream_Element_Offset; | |
270 | -- Rest_First have to be initialized to Buffer'Last + 1 | |
271 | -- Rest_Last have to be initialized to Buffer'Last | |
272 | -- before usage. | |
273 | ||
274 | Allow_Read_Some : in Boolean := False; | |
275 | -- Is it allowed to return Last < Item'Last before end of data. | |
276 | ||
277 | procedure Read | |
278 | (Filter : in out Filter_Type; | |
279 | Item : out Ada.Streams.Stream_Element_Array; | |
280 | Last : out Ada.Streams.Stream_Element_Offset; | |
281 | Flush : in Flush_Mode := No_Flush); | |
282 | -- Compress/Decompress data from generic parameter procedure Read to the | |
283 | -- Item. User should provide Buffer and initialized Rest_First, Rest_Last | |
284 | -- indicators. If Allow_Read_Some is True, Read routines could return | |
285 | -- Last < Item'Last only at end of stream. | |
286 | ||
287 | private | |
288 | ||
289 | use Ada.Streams; | |
290 | ||
291 | pragma Assert (Ada.Streams.Stream_Element'Size = 8); | |
292 | pragma Assert (Ada.Streams.Stream_Element'Modulus = 2**8); | |
293 | ||
294 | type Flush_Mode is new Integer range 0 .. 5; | |
295 | ||
296 | type Compression_Method is new Integer range 8 .. 8; | |
297 | ||
298 | type Strategy_Type is new Integer range 0 .. 3; | |
299 | ||
300 | No_Flush : constant Flush_Mode := 0; | |
301 | Partial_Flush : constant Flush_Mode := 1; | |
302 | Sync_Flush : constant Flush_Mode := 2; | |
303 | Full_Flush : constant Flush_Mode := 3; | |
304 | Finish : constant Flush_Mode := 4; | |
305 | Block_Flush : constant Flush_Mode := 5; | |
306 | ||
307 | Filtered : constant Strategy_Type := 1; | |
308 | Huffman_Only : constant Strategy_Type := 2; | |
309 | RLE : constant Strategy_Type := 3; | |
310 | Default_Strategy : constant Strategy_Type := 0; | |
311 | ||
312 | Deflated : constant Compression_Method := 8; | |
313 | ||
314 | type Z_Stream; | |
315 | ||
316 | type Z_Stream_Access is access all Z_Stream; | |
317 | ||
318 | type Filter_Type is tagged limited record | |
319 | Strm : Z_Stream_Access; | |
320 | Compression : Boolean; | |
321 | Stream_End : Boolean; | |
322 | Header : Header_Type; | |
323 | CRC : Unsigned_32; | |
324 | Offset : Stream_Element_Offset; | |
325 | -- Offset for gzip header/footer output. | |
326 | end record; | |
327 | ||
328 | end ZLib; |