9e052883 |
1 | {*******************************************************} |
2 | { } |
3 | { Borland Delphi Supplemental Components } |
4 | { ZLIB Data Compression Interface Unit } |
5 | { } |
6 | { Copyright (c) 1997,99 Borland Corporation } |
7 | { } |
8 | {*******************************************************} |
9 | |
10 | { Updated for zlib 1.2.x by Cosmin Truta <cosmint@cs.ubbcluj.ro> } |
11 | |
12 | unit ZLib; |
13 | |
14 | interface |
15 | |
16 | uses SysUtils, Classes; |
17 | |
18 | type |
19 | TAlloc = function (AppData: Pointer; Items, Size: Integer): Pointer; cdecl; |
20 | TFree = procedure (AppData, Block: Pointer); cdecl; |
21 | |
22 | // Internal structure. Ignore. |
23 | TZStreamRec = packed record |
24 | next_in: PChar; // next input byte |
25 | avail_in: Integer; // number of bytes available at next_in |
26 | total_in: Longint; // total nb of input bytes read so far |
27 | |
28 | next_out: PChar; // next output byte should be put here |
29 | avail_out: Integer; // remaining free space at next_out |
30 | total_out: Longint; // total nb of bytes output so far |
31 | |
32 | msg: PChar; // last error message, NULL if no error |
33 | internal: Pointer; // not visible by applications |
34 | |
35 | zalloc: TAlloc; // used to allocate the internal state |
36 | zfree: TFree; // used to free the internal state |
37 | AppData: Pointer; // private data object passed to zalloc and zfree |
38 | |
39 | data_type: Integer; // best guess about the data type: ascii or binary |
40 | adler: Longint; // adler32 value of the uncompressed data |
41 | reserved: Longint; // reserved for future use |
42 | end; |
43 | |
44 | // Abstract ancestor class |
45 | TCustomZlibStream = class(TStream) |
46 | private |
47 | FStrm: TStream; |
48 | FStrmPos: Integer; |
49 | FOnProgress: TNotifyEvent; |
50 | FZRec: TZStreamRec; |
51 | FBuffer: array [Word] of Char; |
52 | protected |
53 | procedure Progress(Sender: TObject); dynamic; |
54 | property OnProgress: TNotifyEvent read FOnProgress write FOnProgress; |
55 | constructor Create(Strm: TStream); |
56 | end; |
57 | |
58 | { TCompressionStream compresses data on the fly as data is written to it, and |
59 | stores the compressed data to another stream. |
60 | |
61 | TCompressionStream is write-only and strictly sequential. Reading from the |
62 | stream will raise an exception. Using Seek to move the stream pointer |
63 | will raise an exception. |
64 | |
65 | Output data is cached internally, written to the output stream only when |
66 | the internal output buffer is full. All pending output data is flushed |
67 | when the stream is destroyed. |
68 | |
69 | The Position property returns the number of uncompressed bytes of |
70 | data that have been written to the stream so far. |
71 | |
72 | CompressionRate returns the on-the-fly percentage by which the original |
73 | data has been compressed: (1 - (CompressedBytes / UncompressedBytes)) * 100 |
74 | If raw data size = 100 and compressed data size = 25, the CompressionRate |
75 | is 75% |
76 | |
77 | The OnProgress event is called each time the output buffer is filled and |
78 | written to the output stream. This is useful for updating a progress |
79 | indicator when you are writing a large chunk of data to the compression |
80 | stream in a single call.} |
81 | |
82 | |
83 | TCompressionLevel = (clNone, clFastest, clDefault, clMax); |
84 | |
85 | TCompressionStream = class(TCustomZlibStream) |
86 | private |
87 | function GetCompressionRate: Single; |
88 | public |
89 | constructor Create(CompressionLevel: TCompressionLevel; Dest: TStream); |
90 | destructor Destroy; override; |
91 | function Read(var Buffer; Count: Longint): Longint; override; |
92 | function Write(const Buffer; Count: Longint): Longint; override; |
93 | function Seek(Offset: Longint; Origin: Word): Longint; override; |
94 | property CompressionRate: Single read GetCompressionRate; |
95 | property OnProgress; |
96 | end; |
97 | |
98 | { TDecompressionStream decompresses data on the fly as data is read from it. |
99 | |
100 | Compressed data comes from a separate source stream. TDecompressionStream |
101 | is read-only and unidirectional; you can seek forward in the stream, but not |
102 | backwards. The special case of setting the stream position to zero is |
103 | allowed. Seeking forward decompresses data until the requested position in |
104 | the uncompressed data has been reached. Seeking backwards, seeking relative |
105 | to the end of the stream, requesting the size of the stream, and writing to |
106 | the stream will raise an exception. |
107 | |
108 | The Position property returns the number of bytes of uncompressed data that |
109 | have been read from the stream so far. |
110 | |
111 | The OnProgress event is called each time the internal input buffer of |
112 | compressed data is exhausted and the next block is read from the input stream. |
113 | This is useful for updating a progress indicator when you are reading a |
114 | large chunk of data from the decompression stream in a single call.} |
115 | |
116 | TDecompressionStream = class(TCustomZlibStream) |
117 | public |
118 | constructor Create(Source: TStream); |
119 | destructor Destroy; override; |
120 | function Read(var Buffer; Count: Longint): Longint; override; |
121 | function Write(const Buffer; Count: Longint): Longint; override; |
122 | function Seek(Offset: Longint; Origin: Word): Longint; override; |
123 | property OnProgress; |
124 | end; |
125 | |
126 | |
127 | |
128 | { CompressBuf compresses data, buffer to buffer, in one call. |
129 | In: InBuf = ptr to compressed data |
130 | InBytes = number of bytes in InBuf |
131 | Out: OutBuf = ptr to newly allocated buffer containing decompressed data |
132 | OutBytes = number of bytes in OutBuf } |
133 | procedure CompressBuf(const InBuf: Pointer; InBytes: Integer; |
134 | out OutBuf: Pointer; out OutBytes: Integer); |
135 | |
136 | |
137 | { DecompressBuf decompresses data, buffer to buffer, in one call. |
138 | In: InBuf = ptr to compressed data |
139 | InBytes = number of bytes in InBuf |
140 | OutEstimate = zero, or est. size of the decompressed data |
141 | Out: OutBuf = ptr to newly allocated buffer containing decompressed data |
142 | OutBytes = number of bytes in OutBuf } |
143 | procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer; |
144 | OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer); |
145 | |
146 | { DecompressToUserBuf decompresses data, buffer to buffer, in one call. |
147 | In: InBuf = ptr to compressed data |
148 | InBytes = number of bytes in InBuf |
149 | Out: OutBuf = ptr to user-allocated buffer to contain decompressed data |
150 | BufSize = number of bytes in OutBuf } |
151 | procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer; |
152 | const OutBuf: Pointer; BufSize: Integer); |
153 | |
154 | const |
155 | zlib_version = '1.2.13'; |
156 | |
157 | type |
158 | EZlibError = class(Exception); |
159 | ECompressionError = class(EZlibError); |
160 | EDecompressionError = class(EZlibError); |
161 | |
162 | implementation |
163 | |
164 | uses ZLibConst; |
165 | |
166 | const |
167 | Z_NO_FLUSH = 0; |
168 | Z_PARTIAL_FLUSH = 1; |
169 | Z_SYNC_FLUSH = 2; |
170 | Z_FULL_FLUSH = 3; |
171 | Z_FINISH = 4; |
172 | |
173 | Z_OK = 0; |
174 | Z_STREAM_END = 1; |
175 | Z_NEED_DICT = 2; |
176 | Z_ERRNO = (-1); |
177 | Z_STREAM_ERROR = (-2); |
178 | Z_DATA_ERROR = (-3); |
179 | Z_MEM_ERROR = (-4); |
180 | Z_BUF_ERROR = (-5); |
181 | Z_VERSION_ERROR = (-6); |
182 | |
183 | Z_NO_COMPRESSION = 0; |
184 | Z_BEST_SPEED = 1; |
185 | Z_BEST_COMPRESSION = 9; |
186 | Z_DEFAULT_COMPRESSION = (-1); |
187 | |
188 | Z_FILTERED = 1; |
189 | Z_HUFFMAN_ONLY = 2; |
190 | Z_RLE = 3; |
191 | Z_DEFAULT_STRATEGY = 0; |
192 | |
193 | Z_BINARY = 0; |
194 | Z_ASCII = 1; |
195 | Z_UNKNOWN = 2; |
196 | |
197 | Z_DEFLATED = 8; |
198 | |
199 | |
200 | {$L adler32.obj} |
201 | {$L compress.obj} |
202 | {$L crc32.obj} |
203 | {$L deflate.obj} |
204 | {$L infback.obj} |
205 | {$L inffast.obj} |
206 | {$L inflate.obj} |
207 | {$L inftrees.obj} |
208 | {$L trees.obj} |
209 | {$L uncompr.obj} |
210 | {$L zutil.obj} |
211 | |
212 | procedure adler32; external; |
213 | procedure compressBound; external; |
214 | procedure crc32; external; |
215 | procedure deflateInit2_; external; |
216 | procedure deflateParams; external; |
217 | |
218 | function _malloc(Size: Integer): Pointer; cdecl; |
219 | begin |
220 | Result := AllocMem(Size); |
221 | end; |
222 | |
223 | procedure _free(Block: Pointer); cdecl; |
224 | begin |
225 | FreeMem(Block); |
226 | end; |
227 | |
228 | procedure _memset(P: Pointer; B: Byte; count: Integer); cdecl; |
229 | begin |
230 | FillChar(P^, count, B); |
231 | end; |
232 | |
233 | procedure _memcpy(dest, source: Pointer; count: Integer); cdecl; |
234 | begin |
235 | Move(source^, dest^, count); |
236 | end; |
237 | |
238 | |
239 | |
240 | // deflate compresses data |
241 | function deflateInit_(var strm: TZStreamRec; level: Integer; version: PChar; |
242 | recsize: Integer): Integer; external; |
243 | function deflate(var strm: TZStreamRec; flush: Integer): Integer; external; |
244 | function deflateEnd(var strm: TZStreamRec): Integer; external; |
245 | |
246 | // inflate decompresses data |
247 | function inflateInit_(var strm: TZStreamRec; version: PChar; |
248 | recsize: Integer): Integer; external; |
249 | function inflate(var strm: TZStreamRec; flush: Integer): Integer; external; |
250 | function inflateEnd(var strm: TZStreamRec): Integer; external; |
251 | function inflateReset(var strm: TZStreamRec): Integer; external; |
252 | |
253 | |
254 | function zlibAllocMem(AppData: Pointer; Items, Size: Integer): Pointer; cdecl; |
255 | begin |
256 | // GetMem(Result, Items*Size); |
257 | Result := AllocMem(Items * Size); |
258 | end; |
259 | |
260 | procedure zlibFreeMem(AppData, Block: Pointer); cdecl; |
261 | begin |
262 | FreeMem(Block); |
263 | end; |
264 | |
265 | {function zlibCheck(code: Integer): Integer; |
266 | begin |
267 | Result := code; |
268 | if code < 0 then |
269 | raise EZlibError.Create('error'); //!! |
270 | end;} |
271 | |
272 | function CCheck(code: Integer): Integer; |
273 | begin |
274 | Result := code; |
275 | if code < 0 then |
276 | raise ECompressionError.Create('error'); //!! |
277 | end; |
278 | |
279 | function DCheck(code: Integer): Integer; |
280 | begin |
281 | Result := code; |
282 | if code < 0 then |
283 | raise EDecompressionError.Create('error'); //!! |
284 | end; |
285 | |
286 | procedure CompressBuf(const InBuf: Pointer; InBytes: Integer; |
287 | out OutBuf: Pointer; out OutBytes: Integer); |
288 | var |
289 | strm: TZStreamRec; |
290 | P: Pointer; |
291 | begin |
292 | FillChar(strm, sizeof(strm), 0); |
293 | strm.zalloc := zlibAllocMem; |
294 | strm.zfree := zlibFreeMem; |
295 | OutBytes := ((InBytes + (InBytes div 10) + 12) + 255) and not 255; |
296 | GetMem(OutBuf, OutBytes); |
297 | try |
298 | strm.next_in := InBuf; |
299 | strm.avail_in := InBytes; |
300 | strm.next_out := OutBuf; |
301 | strm.avail_out := OutBytes; |
302 | CCheck(deflateInit_(strm, Z_BEST_COMPRESSION, zlib_version, sizeof(strm))); |
303 | try |
304 | while CCheck(deflate(strm, Z_FINISH)) <> Z_STREAM_END do |
305 | begin |
306 | P := OutBuf; |
307 | Inc(OutBytes, 256); |
308 | ReallocMem(OutBuf, OutBytes); |
309 | strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P))); |
310 | strm.avail_out := 256; |
311 | end; |
312 | finally |
313 | CCheck(deflateEnd(strm)); |
314 | end; |
315 | ReallocMem(OutBuf, strm.total_out); |
316 | OutBytes := strm.total_out; |
317 | except |
318 | FreeMem(OutBuf); |
319 | raise |
320 | end; |
321 | end; |
322 | |
323 | |
324 | procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer; |
325 | OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer); |
326 | var |
327 | strm: TZStreamRec; |
328 | P: Pointer; |
329 | BufInc: Integer; |
330 | begin |
331 | FillChar(strm, sizeof(strm), 0); |
332 | strm.zalloc := zlibAllocMem; |
333 | strm.zfree := zlibFreeMem; |
334 | BufInc := (InBytes + 255) and not 255; |
335 | if OutEstimate = 0 then |
336 | OutBytes := BufInc |
337 | else |
338 | OutBytes := OutEstimate; |
339 | GetMem(OutBuf, OutBytes); |
340 | try |
341 | strm.next_in := InBuf; |
342 | strm.avail_in := InBytes; |
343 | strm.next_out := OutBuf; |
344 | strm.avail_out := OutBytes; |
345 | DCheck(inflateInit_(strm, zlib_version, sizeof(strm))); |
346 | try |
347 | while DCheck(inflate(strm, Z_NO_FLUSH)) <> Z_STREAM_END do |
348 | begin |
349 | P := OutBuf; |
350 | Inc(OutBytes, BufInc); |
351 | ReallocMem(OutBuf, OutBytes); |
352 | strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P))); |
353 | strm.avail_out := BufInc; |
354 | end; |
355 | finally |
356 | DCheck(inflateEnd(strm)); |
357 | end; |
358 | ReallocMem(OutBuf, strm.total_out); |
359 | OutBytes := strm.total_out; |
360 | except |
361 | FreeMem(OutBuf); |
362 | raise |
363 | end; |
364 | end; |
365 | |
366 | procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer; |
367 | const OutBuf: Pointer; BufSize: Integer); |
368 | var |
369 | strm: TZStreamRec; |
370 | begin |
371 | FillChar(strm, sizeof(strm), 0); |
372 | strm.zalloc := zlibAllocMem; |
373 | strm.zfree := zlibFreeMem; |
374 | strm.next_in := InBuf; |
375 | strm.avail_in := InBytes; |
376 | strm.next_out := OutBuf; |
377 | strm.avail_out := BufSize; |
378 | DCheck(inflateInit_(strm, zlib_version, sizeof(strm))); |
379 | try |
380 | if DCheck(inflate(strm, Z_FINISH)) <> Z_STREAM_END then |
381 | raise EZlibError.CreateRes(@sTargetBufferTooSmall); |
382 | finally |
383 | DCheck(inflateEnd(strm)); |
384 | end; |
385 | end; |
386 | |
387 | // TCustomZlibStream |
388 | |
389 | constructor TCustomZLibStream.Create(Strm: TStream); |
390 | begin |
391 | inherited Create; |
392 | FStrm := Strm; |
393 | FStrmPos := Strm.Position; |
394 | FZRec.zalloc := zlibAllocMem; |
395 | FZRec.zfree := zlibFreeMem; |
396 | end; |
397 | |
398 | procedure TCustomZLibStream.Progress(Sender: TObject); |
399 | begin |
400 | if Assigned(FOnProgress) then FOnProgress(Sender); |
401 | end; |
402 | |
403 | |
404 | // TCompressionStream |
405 | |
406 | constructor TCompressionStream.Create(CompressionLevel: TCompressionLevel; |
407 | Dest: TStream); |
408 | const |
409 | Levels: array [TCompressionLevel] of ShortInt = |
410 | (Z_NO_COMPRESSION, Z_BEST_SPEED, Z_DEFAULT_COMPRESSION, Z_BEST_COMPRESSION); |
411 | begin |
412 | inherited Create(Dest); |
413 | FZRec.next_out := FBuffer; |
414 | FZRec.avail_out := sizeof(FBuffer); |
415 | CCheck(deflateInit_(FZRec, Levels[CompressionLevel], zlib_version, sizeof(FZRec))); |
416 | end; |
417 | |
418 | destructor TCompressionStream.Destroy; |
419 | begin |
420 | FZRec.next_in := nil; |
421 | FZRec.avail_in := 0; |
422 | try |
423 | if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos; |
424 | while (CCheck(deflate(FZRec, Z_FINISH)) <> Z_STREAM_END) |
425 | and (FZRec.avail_out = 0) do |
426 | begin |
427 | FStrm.WriteBuffer(FBuffer, sizeof(FBuffer)); |
428 | FZRec.next_out := FBuffer; |
429 | FZRec.avail_out := sizeof(FBuffer); |
430 | end; |
431 | if FZRec.avail_out < sizeof(FBuffer) then |
432 | FStrm.WriteBuffer(FBuffer, sizeof(FBuffer) - FZRec.avail_out); |
433 | finally |
434 | deflateEnd(FZRec); |
435 | end; |
436 | inherited Destroy; |
437 | end; |
438 | |
439 | function TCompressionStream.Read(var Buffer; Count: Longint): Longint; |
440 | begin |
441 | raise ECompressionError.CreateRes(@sInvalidStreamOp); |
442 | end; |
443 | |
444 | function TCompressionStream.Write(const Buffer; Count: Longint): Longint; |
445 | begin |
446 | FZRec.next_in := @Buffer; |
447 | FZRec.avail_in := Count; |
448 | if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos; |
449 | while (FZRec.avail_in > 0) do |
450 | begin |
451 | CCheck(deflate(FZRec, 0)); |
452 | if FZRec.avail_out = 0 then |
453 | begin |
454 | FStrm.WriteBuffer(FBuffer, sizeof(FBuffer)); |
455 | FZRec.next_out := FBuffer; |
456 | FZRec.avail_out := sizeof(FBuffer); |
457 | FStrmPos := FStrm.Position; |
458 | Progress(Self); |
459 | end; |
460 | end; |
461 | Result := Count; |
462 | end; |
463 | |
464 | function TCompressionStream.Seek(Offset: Longint; Origin: Word): Longint; |
465 | begin |
466 | if (Offset = 0) and (Origin = soFromCurrent) then |
467 | Result := FZRec.total_in |
468 | else |
469 | raise ECompressionError.CreateRes(@sInvalidStreamOp); |
470 | end; |
471 | |
472 | function TCompressionStream.GetCompressionRate: Single; |
473 | begin |
474 | if FZRec.total_in = 0 then |
475 | Result := 0 |
476 | else |
477 | Result := (1.0 - (FZRec.total_out / FZRec.total_in)) * 100.0; |
478 | end; |
479 | |
480 | |
481 | // TDecompressionStream |
482 | |
483 | constructor TDecompressionStream.Create(Source: TStream); |
484 | begin |
485 | inherited Create(Source); |
486 | FZRec.next_in := FBuffer; |
487 | FZRec.avail_in := 0; |
488 | DCheck(inflateInit_(FZRec, zlib_version, sizeof(FZRec))); |
489 | end; |
490 | |
491 | destructor TDecompressionStream.Destroy; |
492 | begin |
493 | FStrm.Seek(-FZRec.avail_in, 1); |
494 | inflateEnd(FZRec); |
495 | inherited Destroy; |
496 | end; |
497 | |
498 | function TDecompressionStream.Read(var Buffer; Count: Longint): Longint; |
499 | begin |
500 | FZRec.next_out := @Buffer; |
501 | FZRec.avail_out := Count; |
502 | if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos; |
503 | while (FZRec.avail_out > 0) do |
504 | begin |
505 | if FZRec.avail_in = 0 then |
506 | begin |
507 | FZRec.avail_in := FStrm.Read(FBuffer, sizeof(FBuffer)); |
508 | if FZRec.avail_in = 0 then |
509 | begin |
510 | Result := Count - FZRec.avail_out; |
511 | Exit; |
512 | end; |
513 | FZRec.next_in := FBuffer; |
514 | FStrmPos := FStrm.Position; |
515 | Progress(Self); |
516 | end; |
517 | CCheck(inflate(FZRec, 0)); |
518 | end; |
519 | Result := Count; |
520 | end; |
521 | |
522 | function TDecompressionStream.Write(const Buffer; Count: Longint): Longint; |
523 | begin |
524 | raise EDecompressionError.CreateRes(@sInvalidStreamOp); |
525 | end; |
526 | |
527 | function TDecompressionStream.Seek(Offset: Longint; Origin: Word): Longint; |
528 | var |
529 | I: Integer; |
530 | Buf: array [0..4095] of Char; |
531 | begin |
532 | if (Offset = 0) and (Origin = soFromBeginning) then |
533 | begin |
534 | DCheck(inflateReset(FZRec)); |
535 | FZRec.next_in := FBuffer; |
536 | FZRec.avail_in := 0; |
537 | FStrm.Position := 0; |
538 | FStrmPos := 0; |
539 | end |
540 | else if ( (Offset >= 0) and (Origin = soFromCurrent)) or |
541 | ( ((Offset - FZRec.total_out) > 0) and (Origin = soFromBeginning)) then |
542 | begin |
543 | if Origin = soFromBeginning then Dec(Offset, FZRec.total_out); |
544 | if Offset > 0 then |
545 | begin |
546 | for I := 1 to Offset div sizeof(Buf) do |
547 | ReadBuffer(Buf, sizeof(Buf)); |
548 | ReadBuffer(Buf, Offset mod sizeof(Buf)); |
549 | end; |
550 | end |
551 | else |
552 | raise EDecompressionError.CreateRes(@sInvalidStreamOp); |
553 | Result := FZRec.total_out; |
554 | end; |
555 | |
556 | |
557 | end. |