| 1 | ---------------------------------------------------------------- |
| 2 | -- ZLib for Ada thick binding. -- |
| 3 | -- -- |
| 4 | -- Copyright (C) 2002-2004 Dmitriy Anisimkov -- |
| 5 | -- -- |
| 6 | -- Open source license information is in the zlib.ads file. -- |
| 7 | ---------------------------------------------------------------- |
| 8 | |
| 9 | -- $Id: zlib.adb,v 1.31 2004/09/06 06:53:19 vagul Exp $ |
| 10 | |
| 11 | with Ada.Exceptions; |
| 12 | with Ada.Unchecked_Conversion; |
| 13 | with Ada.Unchecked_Deallocation; |
| 14 | |
| 15 | with Interfaces.C.Strings; |
| 16 | |
| 17 | with ZLib.Thin; |
| 18 | |
| 19 | package body ZLib is |
| 20 | |
| 21 | use type Thin.Int; |
| 22 | |
| 23 | type Z_Stream is new Thin.Z_Stream; |
| 24 | |
| 25 | type Return_Code_Enum is |
| 26 | (OK, |
| 27 | STREAM_END, |
| 28 | NEED_DICT, |
| 29 | ERRNO, |
| 30 | STREAM_ERROR, |
| 31 | DATA_ERROR, |
| 32 | MEM_ERROR, |
| 33 | BUF_ERROR, |
| 34 | VERSION_ERROR); |
| 35 | |
| 36 | type Flate_Step_Function is access |
| 37 | function (Strm : in Thin.Z_Streamp; Flush : in Thin.Int) return Thin.Int; |
| 38 | pragma Convention (C, Flate_Step_Function); |
| 39 | |
| 40 | type Flate_End_Function is access |
| 41 | function (Ctrm : in Thin.Z_Streamp) return Thin.Int; |
| 42 | pragma Convention (C, Flate_End_Function); |
| 43 | |
| 44 | type Flate_Type is record |
| 45 | Step : Flate_Step_Function; |
| 46 | Done : Flate_End_Function; |
| 47 | end record; |
| 48 | |
| 49 | subtype Footer_Array is Stream_Element_Array (1 .. 8); |
| 50 | |
| 51 | Simple_GZip_Header : constant Stream_Element_Array (1 .. 10) |
| 52 | := (16#1f#, 16#8b#, -- Magic header |
| 53 | 16#08#, -- Z_DEFLATED |
| 54 | 16#00#, -- Flags |
| 55 | 16#00#, 16#00#, 16#00#, 16#00#, -- Time |
| 56 | 16#00#, -- XFlags |
| 57 | 16#03# -- OS code |
| 58 | ); |
| 59 | -- The simplest gzip header is not for informational, but just for |
| 60 | -- gzip format compatibility. |
| 61 | -- Note that some code below is using assumption |
| 62 | -- Simple_GZip_Header'Last > Footer_Array'Last, so do not make |
| 63 | -- Simple_GZip_Header'Last <= Footer_Array'Last. |
| 64 | |
| 65 | Return_Code : constant array (Thin.Int range <>) of Return_Code_Enum |
| 66 | := (0 => OK, |
| 67 | 1 => STREAM_END, |
| 68 | 2 => NEED_DICT, |
| 69 | -1 => ERRNO, |
| 70 | -2 => STREAM_ERROR, |
| 71 | -3 => DATA_ERROR, |
| 72 | -4 => MEM_ERROR, |
| 73 | -5 => BUF_ERROR, |
| 74 | -6 => VERSION_ERROR); |
| 75 | |
| 76 | Flate : constant array (Boolean) of Flate_Type |
| 77 | := (True => (Step => Thin.Deflate'Access, |
| 78 | Done => Thin.DeflateEnd'Access), |
| 79 | False => (Step => Thin.Inflate'Access, |
| 80 | Done => Thin.InflateEnd'Access)); |
| 81 | |
| 82 | Flush_Finish : constant array (Boolean) of Flush_Mode |
| 83 | := (True => Finish, False => No_Flush); |
| 84 | |
| 85 | procedure Raise_Error (Stream : in Z_Stream); |
| 86 | pragma Inline (Raise_Error); |
| 87 | |
| 88 | procedure Raise_Error (Message : in String); |
| 89 | pragma Inline (Raise_Error); |
| 90 | |
| 91 | procedure Check_Error (Stream : in Z_Stream; Code : in Thin.Int); |
| 92 | |
| 93 | procedure Free is new Ada.Unchecked_Deallocation |
| 94 | (Z_Stream, Z_Stream_Access); |
| 95 | |
| 96 | function To_Thin_Access is new Ada.Unchecked_Conversion |
| 97 | (Z_Stream_Access, Thin.Z_Streamp); |
| 98 | |
| 99 | procedure Translate_GZip |
| 100 | (Filter : in out Filter_Type; |
| 101 | In_Data : in Ada.Streams.Stream_Element_Array; |
| 102 | In_Last : out Ada.Streams.Stream_Element_Offset; |
| 103 | Out_Data : out Ada.Streams.Stream_Element_Array; |
| 104 | Out_Last : out Ada.Streams.Stream_Element_Offset; |
| 105 | Flush : in Flush_Mode); |
| 106 | -- Separate translate routine for make gzip header. |
| 107 | |
| 108 | procedure Translate_Auto |
| 109 | (Filter : in out Filter_Type; |
| 110 | In_Data : in Ada.Streams.Stream_Element_Array; |
| 111 | In_Last : out Ada.Streams.Stream_Element_Offset; |
| 112 | Out_Data : out Ada.Streams.Stream_Element_Array; |
| 113 | Out_Last : out Ada.Streams.Stream_Element_Offset; |
| 114 | Flush : in Flush_Mode); |
| 115 | -- translate routine without additional headers. |
| 116 | |
| 117 | ----------------- |
| 118 | -- Check_Error -- |
| 119 | ----------------- |
| 120 | |
| 121 | procedure Check_Error (Stream : in Z_Stream; Code : in Thin.Int) is |
| 122 | use type Thin.Int; |
| 123 | begin |
| 124 | if Code /= Thin.Z_OK then |
| 125 | Raise_Error |
| 126 | (Return_Code_Enum'Image (Return_Code (Code)) |
| 127 | & ": " & Last_Error_Message (Stream)); |
| 128 | end if; |
| 129 | end Check_Error; |
| 130 | |
| 131 | ----------- |
| 132 | -- Close -- |
| 133 | ----------- |
| 134 | |
| 135 | procedure Close |
| 136 | (Filter : in out Filter_Type; |
| 137 | Ignore_Error : in Boolean := False) |
| 138 | is |
| 139 | Code : Thin.Int; |
| 140 | begin |
| 141 | if not Ignore_Error and then not Is_Open (Filter) then |
| 142 | raise Status_Error; |
| 143 | end if; |
| 144 | |
| 145 | Code := Flate (Filter.Compression).Done (To_Thin_Access (Filter.Strm)); |
| 146 | |
| 147 | if Ignore_Error or else Code = Thin.Z_OK then |
| 148 | Free (Filter.Strm); |
| 149 | else |
| 150 | declare |
| 151 | Error_Message : constant String |
| 152 | := Last_Error_Message (Filter.Strm.all); |
| 153 | begin |
| 154 | Free (Filter.Strm); |
| 155 | Ada.Exceptions.Raise_Exception |
| 156 | (ZLib_Error'Identity, |
| 157 | Return_Code_Enum'Image (Return_Code (Code)) |
| 158 | & ": " & Error_Message); |
| 159 | end; |
| 160 | end if; |
| 161 | end Close; |
| 162 | |
| 163 | ----------- |
| 164 | -- CRC32 -- |
| 165 | ----------- |
| 166 | |
| 167 | function CRC32 |
| 168 | (CRC : in Unsigned_32; |
| 169 | Data : in Ada.Streams.Stream_Element_Array) |
| 170 | return Unsigned_32 |
| 171 | is |
| 172 | use Thin; |
| 173 | begin |
| 174 | return Unsigned_32 (crc32 (ULong (CRC), |
| 175 | Data'Address, |
| 176 | Data'Length)); |
| 177 | end CRC32; |
| 178 | |
| 179 | procedure CRC32 |
| 180 | (CRC : in out Unsigned_32; |
| 181 | Data : in Ada.Streams.Stream_Element_Array) is |
| 182 | begin |
| 183 | CRC := CRC32 (CRC, Data); |
| 184 | end CRC32; |
| 185 | |
| 186 | ------------------ |
| 187 | -- Deflate_Init -- |
| 188 | ------------------ |
| 189 | |
| 190 | procedure Deflate_Init |
| 191 | (Filter : in out Filter_Type; |
| 192 | Level : in Compression_Level := Default_Compression; |
| 193 | Strategy : in Strategy_Type := Default_Strategy; |
| 194 | Method : in Compression_Method := Deflated; |
| 195 | Window_Bits : in Window_Bits_Type := Default_Window_Bits; |
| 196 | Memory_Level : in Memory_Level_Type := Default_Memory_Level; |
| 197 | Header : in Header_Type := Default) |
| 198 | is |
| 199 | use type Thin.Int; |
| 200 | Win_Bits : Thin.Int := Thin.Int (Window_Bits); |
| 201 | begin |
| 202 | if Is_Open (Filter) then |
| 203 | raise Status_Error; |
| 204 | end if; |
| 205 | |
| 206 | -- We allow ZLib to make header only in case of default header type. |
| 207 | -- Otherwise we would either do header by ourselves, or do not do |
| 208 | -- header at all. |
| 209 | |
| 210 | if Header = None or else Header = GZip then |
| 211 | Win_Bits := -Win_Bits; |
| 212 | end if; |
| 213 | |
| 214 | -- For the GZip CRC calculation and make headers. |
| 215 | |
| 216 | if Header = GZip then |
| 217 | Filter.CRC := 0; |
| 218 | Filter.Offset := Simple_GZip_Header'First; |
| 219 | else |
| 220 | Filter.Offset := Simple_GZip_Header'Last + 1; |
| 221 | end if; |
| 222 | |
| 223 | Filter.Strm := new Z_Stream; |
| 224 | Filter.Compression := True; |
| 225 | Filter.Stream_End := False; |
| 226 | Filter.Header := Header; |
| 227 | |
| 228 | if Thin.Deflate_Init |
| 229 | (To_Thin_Access (Filter.Strm), |
| 230 | Level => Thin.Int (Level), |
| 231 | method => Thin.Int (Method), |
| 232 | windowBits => Win_Bits, |
| 233 | memLevel => Thin.Int (Memory_Level), |
| 234 | strategy => Thin.Int (Strategy)) /= Thin.Z_OK |
| 235 | then |
| 236 | Raise_Error (Filter.Strm.all); |
| 237 | end if; |
| 238 | end Deflate_Init; |
| 239 | |
| 240 | ----------- |
| 241 | -- Flush -- |
| 242 | ----------- |
| 243 | |
| 244 | procedure Flush |
| 245 | (Filter : in out Filter_Type; |
| 246 | Out_Data : out Ada.Streams.Stream_Element_Array; |
| 247 | Out_Last : out Ada.Streams.Stream_Element_Offset; |
| 248 | Flush : in Flush_Mode) |
| 249 | is |
| 250 | No_Data : Stream_Element_Array := (1 .. 0 => 0); |
| 251 | Last : Stream_Element_Offset; |
| 252 | begin |
| 253 | Translate (Filter, No_Data, Last, Out_Data, Out_Last, Flush); |
| 254 | end Flush; |
| 255 | |
| 256 | ----------------------- |
| 257 | -- Generic_Translate -- |
| 258 | ----------------------- |
| 259 | |
| 260 | procedure Generic_Translate |
| 261 | (Filter : in out ZLib.Filter_Type; |
| 262 | In_Buffer_Size : in Integer := Default_Buffer_Size; |
| 263 | Out_Buffer_Size : in Integer := Default_Buffer_Size) |
| 264 | is |
| 265 | In_Buffer : Stream_Element_Array |
| 266 | (1 .. Stream_Element_Offset (In_Buffer_Size)); |
| 267 | Out_Buffer : Stream_Element_Array |
| 268 | (1 .. Stream_Element_Offset (Out_Buffer_Size)); |
| 269 | Last : Stream_Element_Offset; |
| 270 | In_Last : Stream_Element_Offset; |
| 271 | In_First : Stream_Element_Offset; |
| 272 | Out_Last : Stream_Element_Offset; |
| 273 | begin |
| 274 | Main : loop |
| 275 | Data_In (In_Buffer, Last); |
| 276 | |
| 277 | In_First := In_Buffer'First; |
| 278 | |
| 279 | loop |
| 280 | Translate |
| 281 | (Filter => Filter, |
| 282 | In_Data => In_Buffer (In_First .. Last), |
| 283 | In_Last => In_Last, |
| 284 | Out_Data => Out_Buffer, |
| 285 | Out_Last => Out_Last, |
| 286 | Flush => Flush_Finish (Last < In_Buffer'First)); |
| 287 | |
| 288 | if Out_Buffer'First <= Out_Last then |
| 289 | Data_Out (Out_Buffer (Out_Buffer'First .. Out_Last)); |
| 290 | end if; |
| 291 | |
| 292 | exit Main when Stream_End (Filter); |
| 293 | |
| 294 | -- The end of in buffer. |
| 295 | |
| 296 | exit when In_Last = Last; |
| 297 | |
| 298 | In_First := In_Last + 1; |
| 299 | end loop; |
| 300 | end loop Main; |
| 301 | |
| 302 | end Generic_Translate; |
| 303 | |
| 304 | ------------------ |
| 305 | -- Inflate_Init -- |
| 306 | ------------------ |
| 307 | |
| 308 | procedure Inflate_Init |
| 309 | (Filter : in out Filter_Type; |
| 310 | Window_Bits : in Window_Bits_Type := Default_Window_Bits; |
| 311 | Header : in Header_Type := Default) |
| 312 | is |
| 313 | use type Thin.Int; |
| 314 | Win_Bits : Thin.Int := Thin.Int (Window_Bits); |
| 315 | |
| 316 | procedure Check_Version; |
| 317 | -- Check the latest header types compatibility. |
| 318 | |
| 319 | procedure Check_Version is |
| 320 | begin |
| 321 | if Version <= "1.1.4" then |
| 322 | Raise_Error |
| 323 | ("Inflate header type " & Header_Type'Image (Header) |
| 324 | & " incompatible with ZLib version " & Version); |
| 325 | end if; |
| 326 | end Check_Version; |
| 327 | |
| 328 | begin |
| 329 | if Is_Open (Filter) then |
| 330 | raise Status_Error; |
| 331 | end if; |
| 332 | |
| 333 | case Header is |
| 334 | when None => |
| 335 | Check_Version; |
| 336 | |
| 337 | -- Inflate data without headers determined |
| 338 | -- by negative Win_Bits. |
| 339 | |
| 340 | Win_Bits := -Win_Bits; |
| 341 | when GZip => |
| 342 | Check_Version; |
| 343 | |
| 344 | -- Inflate gzip data defined by flag 16. |
| 345 | |
| 346 | Win_Bits := Win_Bits + 16; |
| 347 | when Auto => |
| 348 | Check_Version; |
| 349 | |
| 350 | -- Inflate with automatic detection |
| 351 | -- of gzip or native header defined by flag 32. |
| 352 | |
| 353 | Win_Bits := Win_Bits + 32; |
| 354 | when Default => null; |
| 355 | end case; |
| 356 | |
| 357 | Filter.Strm := new Z_Stream; |
| 358 | Filter.Compression := False; |
| 359 | Filter.Stream_End := False; |
| 360 | Filter.Header := Header; |
| 361 | |
| 362 | if Thin.Inflate_Init |
| 363 | (To_Thin_Access (Filter.Strm), Win_Bits) /= Thin.Z_OK |
| 364 | then |
| 365 | Raise_Error (Filter.Strm.all); |
| 366 | end if; |
| 367 | end Inflate_Init; |
| 368 | |
| 369 | ------------- |
| 370 | -- Is_Open -- |
| 371 | ------------- |
| 372 | |
| 373 | function Is_Open (Filter : in Filter_Type) return Boolean is |
| 374 | begin |
| 375 | return Filter.Strm /= null; |
| 376 | end Is_Open; |
| 377 | |
| 378 | ----------------- |
| 379 | -- Raise_Error -- |
| 380 | ----------------- |
| 381 | |
| 382 | procedure Raise_Error (Message : in String) is |
| 383 | begin |
| 384 | Ada.Exceptions.Raise_Exception (ZLib_Error'Identity, Message); |
| 385 | end Raise_Error; |
| 386 | |
| 387 | procedure Raise_Error (Stream : in Z_Stream) is |
| 388 | begin |
| 389 | Raise_Error (Last_Error_Message (Stream)); |
| 390 | end Raise_Error; |
| 391 | |
| 392 | ---------- |
| 393 | -- Read -- |
| 394 | ---------- |
| 395 | |
| 396 | procedure Read |
| 397 | (Filter : in out Filter_Type; |
| 398 | Item : out Ada.Streams.Stream_Element_Array; |
| 399 | Last : out Ada.Streams.Stream_Element_Offset; |
| 400 | Flush : in Flush_Mode := No_Flush) |
| 401 | is |
| 402 | In_Last : Stream_Element_Offset; |
| 403 | Item_First : Ada.Streams.Stream_Element_Offset := Item'First; |
| 404 | V_Flush : Flush_Mode := Flush; |
| 405 | |
| 406 | begin |
| 407 | pragma Assert (Rest_First in Buffer'First .. Buffer'Last + 1); |
| 408 | pragma Assert (Rest_Last in Buffer'First - 1 .. Buffer'Last); |
| 409 | |
| 410 | loop |
| 411 | if Rest_Last = Buffer'First - 1 then |
| 412 | V_Flush := Finish; |
| 413 | |
| 414 | elsif Rest_First > Rest_Last then |
| 415 | Read (Buffer, Rest_Last); |
| 416 | Rest_First := Buffer'First; |
| 417 | |
| 418 | if Rest_Last < Buffer'First then |
| 419 | V_Flush := Finish; |
| 420 | end if; |
| 421 | end if; |
| 422 | |
| 423 | Translate |
| 424 | (Filter => Filter, |
| 425 | In_Data => Buffer (Rest_First .. Rest_Last), |
| 426 | In_Last => In_Last, |
| 427 | Out_Data => Item (Item_First .. Item'Last), |
| 428 | Out_Last => Last, |
| 429 | Flush => V_Flush); |
| 430 | |
| 431 | Rest_First := In_Last + 1; |
| 432 | |
| 433 | exit when Stream_End (Filter) |
| 434 | or else Last = Item'Last |
| 435 | or else (Last >= Item'First and then Allow_Read_Some); |
| 436 | |
| 437 | Item_First := Last + 1; |
| 438 | end loop; |
| 439 | end Read; |
| 440 | |
| 441 | ---------------- |
| 442 | -- Stream_End -- |
| 443 | ---------------- |
| 444 | |
| 445 | function Stream_End (Filter : in Filter_Type) return Boolean is |
| 446 | begin |
| 447 | if Filter.Header = GZip and Filter.Compression then |
| 448 | return Filter.Stream_End |
| 449 | and then Filter.Offset = Footer_Array'Last + 1; |
| 450 | else |
| 451 | return Filter.Stream_End; |
| 452 | end if; |
| 453 | end Stream_End; |
| 454 | |
| 455 | -------------- |
| 456 | -- Total_In -- |
| 457 | -------------- |
| 458 | |
| 459 | function Total_In (Filter : in Filter_Type) return Count is |
| 460 | begin |
| 461 | return Count (Thin.Total_In (To_Thin_Access (Filter.Strm).all)); |
| 462 | end Total_In; |
| 463 | |
| 464 | --------------- |
| 465 | -- Total_Out -- |
| 466 | --------------- |
| 467 | |
| 468 | function Total_Out (Filter : in Filter_Type) return Count is |
| 469 | begin |
| 470 | return Count (Thin.Total_Out (To_Thin_Access (Filter.Strm).all)); |
| 471 | end Total_Out; |
| 472 | |
| 473 | --------------- |
| 474 | -- Translate -- |
| 475 | --------------- |
| 476 | |
| 477 | procedure Translate |
| 478 | (Filter : in out Filter_Type; |
| 479 | In_Data : in Ada.Streams.Stream_Element_Array; |
| 480 | In_Last : out Ada.Streams.Stream_Element_Offset; |
| 481 | Out_Data : out Ada.Streams.Stream_Element_Array; |
| 482 | Out_Last : out Ada.Streams.Stream_Element_Offset; |
| 483 | Flush : in Flush_Mode) is |
| 484 | begin |
| 485 | if Filter.Header = GZip and then Filter.Compression then |
| 486 | Translate_GZip |
| 487 | (Filter => Filter, |
| 488 | In_Data => In_Data, |
| 489 | In_Last => In_Last, |
| 490 | Out_Data => Out_Data, |
| 491 | Out_Last => Out_Last, |
| 492 | Flush => Flush); |
| 493 | else |
| 494 | Translate_Auto |
| 495 | (Filter => Filter, |
| 496 | In_Data => In_Data, |
| 497 | In_Last => In_Last, |
| 498 | Out_Data => Out_Data, |
| 499 | Out_Last => Out_Last, |
| 500 | Flush => Flush); |
| 501 | end if; |
| 502 | end Translate; |
| 503 | |
| 504 | -------------------- |
| 505 | -- Translate_Auto -- |
| 506 | -------------------- |
| 507 | |
| 508 | procedure Translate_Auto |
| 509 | (Filter : in out Filter_Type; |
| 510 | In_Data : in Ada.Streams.Stream_Element_Array; |
| 511 | In_Last : out Ada.Streams.Stream_Element_Offset; |
| 512 | Out_Data : out Ada.Streams.Stream_Element_Array; |
| 513 | Out_Last : out Ada.Streams.Stream_Element_Offset; |
| 514 | Flush : in Flush_Mode) |
| 515 | is |
| 516 | use type Thin.Int; |
| 517 | Code : Thin.Int; |
| 518 | |
| 519 | begin |
| 520 | if not Is_Open (Filter) then |
| 521 | raise Status_Error; |
| 522 | end if; |
| 523 | |
| 524 | if Out_Data'Length = 0 and then In_Data'Length = 0 then |
| 525 | raise Constraint_Error; |
| 526 | end if; |
| 527 | |
| 528 | Set_Out (Filter.Strm.all, Out_Data'Address, Out_Data'Length); |
| 529 | Set_In (Filter.Strm.all, In_Data'Address, In_Data'Length); |
| 530 | |
| 531 | Code := Flate (Filter.Compression).Step |
| 532 | (To_Thin_Access (Filter.Strm), |
| 533 | Thin.Int (Flush)); |
| 534 | |
| 535 | if Code = Thin.Z_STREAM_END then |
| 536 | Filter.Stream_End := True; |
| 537 | else |
| 538 | Check_Error (Filter.Strm.all, Code); |
| 539 | end if; |
| 540 | |
| 541 | In_Last := In_Data'Last |
| 542 | - Stream_Element_Offset (Avail_In (Filter.Strm.all)); |
| 543 | Out_Last := Out_Data'Last |
| 544 | - Stream_Element_Offset (Avail_Out (Filter.Strm.all)); |
| 545 | end Translate_Auto; |
| 546 | |
| 547 | -------------------- |
| 548 | -- Translate_GZip -- |
| 549 | -------------------- |
| 550 | |
| 551 | procedure Translate_GZip |
| 552 | (Filter : in out Filter_Type; |
| 553 | In_Data : in Ada.Streams.Stream_Element_Array; |
| 554 | In_Last : out Ada.Streams.Stream_Element_Offset; |
| 555 | Out_Data : out Ada.Streams.Stream_Element_Array; |
| 556 | Out_Last : out Ada.Streams.Stream_Element_Offset; |
| 557 | Flush : in Flush_Mode) |
| 558 | is |
| 559 | Out_First : Stream_Element_Offset; |
| 560 | |
| 561 | procedure Add_Data (Data : in Stream_Element_Array); |
| 562 | -- Add data to stream from the Filter.Offset till necessary, |
| 563 | -- used for add gzip headr/footer. |
| 564 | |
| 565 | procedure Put_32 |
| 566 | (Item : in out Stream_Element_Array; |
| 567 | Data : in Unsigned_32); |
| 568 | pragma Inline (Put_32); |
| 569 | |
| 570 | -------------- |
| 571 | -- Add_Data -- |
| 572 | -------------- |
| 573 | |
| 574 | procedure Add_Data (Data : in Stream_Element_Array) is |
| 575 | Data_First : Stream_Element_Offset renames Filter.Offset; |
| 576 | Data_Last : Stream_Element_Offset; |
| 577 | Data_Len : Stream_Element_Offset; -- -1 |
| 578 | Out_Len : Stream_Element_Offset; -- -1 |
| 579 | begin |
| 580 | Out_First := Out_Last + 1; |
| 581 | |
| 582 | if Data_First > Data'Last then |
| 583 | return; |
| 584 | end if; |
| 585 | |
| 586 | Data_Len := Data'Last - Data_First; |
| 587 | Out_Len := Out_Data'Last - Out_First; |
| 588 | |
| 589 | if Data_Len <= Out_Len then |
| 590 | Out_Last := Out_First + Data_Len; |
| 591 | Data_Last := Data'Last; |
| 592 | else |
| 593 | Out_Last := Out_Data'Last; |
| 594 | Data_Last := Data_First + Out_Len; |
| 595 | end if; |
| 596 | |
| 597 | Out_Data (Out_First .. Out_Last) := Data (Data_First .. Data_Last); |
| 598 | |
| 599 | Data_First := Data_Last + 1; |
| 600 | Out_First := Out_Last + 1; |
| 601 | end Add_Data; |
| 602 | |
| 603 | ------------ |
| 604 | -- Put_32 -- |
| 605 | ------------ |
| 606 | |
| 607 | procedure Put_32 |
| 608 | (Item : in out Stream_Element_Array; |
| 609 | Data : in Unsigned_32) |
| 610 | is |
| 611 | D : Unsigned_32 := Data; |
| 612 | begin |
| 613 | for J in Item'First .. Item'First + 3 loop |
| 614 | Item (J) := Stream_Element (D and 16#FF#); |
| 615 | D := Shift_Right (D, 8); |
| 616 | end loop; |
| 617 | end Put_32; |
| 618 | |
| 619 | begin |
| 620 | Out_Last := Out_Data'First - 1; |
| 621 | |
| 622 | if not Filter.Stream_End then |
| 623 | Add_Data (Simple_GZip_Header); |
| 624 | |
| 625 | Translate_Auto |
| 626 | (Filter => Filter, |
| 627 | In_Data => In_Data, |
| 628 | In_Last => In_Last, |
| 629 | Out_Data => Out_Data (Out_First .. Out_Data'Last), |
| 630 | Out_Last => Out_Last, |
| 631 | Flush => Flush); |
| 632 | |
| 633 | CRC32 (Filter.CRC, In_Data (In_Data'First .. In_Last)); |
| 634 | end if; |
| 635 | |
| 636 | if Filter.Stream_End and then Out_Last <= Out_Data'Last then |
| 637 | -- This detection method would work only when |
| 638 | -- Simple_GZip_Header'Last > Footer_Array'Last |
| 639 | |
| 640 | if Filter.Offset = Simple_GZip_Header'Last + 1 then |
| 641 | Filter.Offset := Footer_Array'First; |
| 642 | end if; |
| 643 | |
| 644 | declare |
| 645 | Footer : Footer_Array; |
| 646 | begin |
| 647 | Put_32 (Footer, Filter.CRC); |
| 648 | Put_32 (Footer (Footer'First + 4 .. Footer'Last), |
| 649 | Unsigned_32 (Total_In (Filter))); |
| 650 | Add_Data (Footer); |
| 651 | end; |
| 652 | end if; |
| 653 | end Translate_GZip; |
| 654 | |
| 655 | ------------- |
| 656 | -- Version -- |
| 657 | ------------- |
| 658 | |
| 659 | function Version return String is |
| 660 | begin |
| 661 | return Interfaces.C.Strings.Value (Thin.zlibVersion); |
| 662 | end Version; |
| 663 | |
| 664 | ----------- |
| 665 | -- Write -- |
| 666 | ----------- |
| 667 | |
| 668 | procedure Write |
| 669 | (Filter : in out Filter_Type; |
| 670 | Item : in Ada.Streams.Stream_Element_Array; |
| 671 | Flush : in Flush_Mode := No_Flush) |
| 672 | is |
| 673 | Buffer : Stream_Element_Array (1 .. Buffer_Size); |
| 674 | In_Last : Stream_Element_Offset; |
| 675 | Out_Last : Stream_Element_Offset; |
| 676 | In_First : Stream_Element_Offset := Item'First; |
| 677 | begin |
| 678 | if Item'Length = 0 and Flush = No_Flush then |
| 679 | return; |
| 680 | end if; |
| 681 | |
| 682 | loop |
| 683 | Translate |
| 684 | (Filter => Filter, |
| 685 | In_Data => Item (In_First .. Item'Last), |
| 686 | In_Last => In_Last, |
| 687 | Out_Data => Buffer, |
| 688 | Out_Last => Out_Last, |
| 689 | Flush => Flush); |
| 690 | |
| 691 | if Out_Last >= Buffer'First then |
| 692 | Write (Buffer (1 .. Out_Last)); |
| 693 | end if; |
| 694 | |
| 695 | exit when In_Last = Item'Last or Stream_End (Filter); |
| 696 | |
| 697 | In_First := In_Last + 1; |
| 698 | end loop; |
| 699 | end Write; |
| 700 | |
| 701 | end ZLib; |