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;