![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to inflate.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [truecrypt] / truecrypt / common|
Return to inflate.c CVS log | Up to [truecrypt] / truecrypt / common |
1.1 root 1: /* inflate.c -- put in the public domain by Mark Adler */
2:
3: /* Decompresses raw data compressed using the DEFLATE algorithm (RFC 1951) */
4:
5: /* You can do whatever you like with this source file, though I would
6: prefer that if you modify it and redistribute it that you include
7: comments to that effect with your name and the date. Thank you.
8:
9: History:
10: vers date who what
11: ---- --------- -------------- ------------------------------------
12: a ~~ Feb 92 M. Adler used full (large, one-step) lookup table
13: b1 21 Mar 92 M. Adler first version with partial lookup tables
14: b2 21 Mar 92 M. Adler fixed bug in fixed-code blocks
15: b3 22 Mar 92 M. Adler sped up match copies, cleaned up some
16: b4 25 Mar 92 M. Adler added prototypes; removed window[] (now
17: is the responsibility of unzip.h--also
18: changed name to slide[]), so needs diffs
19: for unzip.c and unzip.h (this allows
20: compiling in the small model on MSDOS);
21: fixed cast of q in huft_build();
22: b5 26 Mar 92 M. Adler got rid of unintended macro recursion.
23: b6 27 Mar 92 M. Adler got rid of nextbyte() routine. fixed
24: bug in inflate_fixed().
25: c1 30 Mar 92 M. Adler removed lbits, dbits environment variables.
26: changed BMAX to 16 for explode. Removed
27: OUTB usage, and replaced it with flush()--
28: this was a 20% speed improvement! Added
29: an explode.c (to replace unimplod.c) that
30: uses the huft routines here. Removed
31: register union.
32: c2 4 Apr 92 M. Adler fixed bug for file sizes a multiple of 32k.
33: c3 10 Apr 92 M. Adler reduced memory of code tables made by
34: huft_build significantly (factor of two to
35: three).
36: c4 15 Apr 92 M. Adler added NOMEMCPY do kill use of memcpy().
37: worked around a Turbo C optimization bug.
38: c5 21 Apr 92 M. Adler added the WSIZE #define to allow reducing
39: the 32K window size for specialized
40: applications.
41: c6 31 May 92 M. Adler added some typecasts to eliminate warnings
42: c7 27 Jun 92 G. Roelofs added some more typecasts (444: MSC bug).
43: c8 5 Oct 92 J-l. Gailly added ifdef'd code to deal with PKZIP bug.
44: c9 9 Oct 92 M. Adler removed a memory error message (~line 416).
45: c10 17 Oct 92 G. Roelofs changed ULONG/UWORD/byte to ulg/ush/uch,
46: removed old inflate, renamed inflate_entry
47: to inflate, added Mark's fix to a comment.
48: c10.5 14 Dec 92 M. Adler fix up error messages for incomplete trees.
49: c11 2 Jan 93 M. Adler fixed bug in detection of incomplete
50: tables, and removed assumption that EOB is
51: the longest code (bad assumption).
52: c12 3 Jan 93 M. Adler make tables for fixed blocks only once.
53: c13 5 Jan 93 M. Adler allow all zero length codes (pkzip 2.04c
54: outputs one zero length code for an empty
55: distance tree).
56: c14 12 Mar 93 M. Adler made inflate.c standalone with the
57: introduction of inflate.h.
58: c14b 16 Jul 93 G. Roelofs added (unsigned) typecast to w at 470.
59: c14c 19 Jul 93 J. Bush changed v[N_MAX], l[288], ll[28x+3x] arrays
60: to static for Amiga.
61: c14d 13 Aug 93 J-l. Gailly de-complicatified Mark's c[*p++]++ thing.
62: c14e 8 Oct 93 G. Roelofs changed memset() to memzero().
63: c14f 22 Oct 93 G. Roelofs renamed quietflg to qflag; made Trace()
64: conditional; added inflate_free().
65: c14g 28 Oct 93 G. Roelofs changed l/(lx+1) macro to pointer (Cray bug)
66: c14h 7 Dec 93 C. Ghisler huft_build() optimizations.
67: c14i 9 Jan 94 A. Verheijen set fixed_t{d,l} to NULL after freeing;
68: G. Roelofs check NEXTBYTE macro for EOF.
69: c14j 23 Jan 94 G. Roelofs removed Ghisler "optimizations"; ifdef'd
70: EOF check.
71: c14k 27 Feb 94 G. Roelofs added some typecasts to avoid warnings.
72: c14l 9 Apr 94 G. Roelofs fixed split comments on preprocessor lines
73: to avoid bug in Encore compiler.
74: c14m 7 Jul 94 P. Kienitz modified to allow assembler version of
75: inflate_codes() (define ASM_INFLATECODES)
76: c14n 22 Jul 94 G. Roelofs changed fprintf to macro for DLL versions
77: c14o 23 Aug 94 C. Spieler added a newline to a debug statement;
78: G. Roelofs added another typecast to avoid MSC warning
79: c14p 4 Oct 94 G. Roelofs added (voidp *) cast to free() argument
80: c14q 30 Oct 94 G. Roelofs changed fprintf macro to MESSAGE()
81: c14r 1 Nov 94 G. Roelofs fixed possible redefinition of CHECK_EOF
82: c14s 7 May 95 S. Maxwell OS/2 DLL globals stuff incorporated;
83: P. Kienitz "fixed" ASM_INFLATECODES macro/prototype
84: c14t 18 Aug 95 G. Roelofs added inflate() to use zlib functions;
85: changed voidp to zvoid; moved huft_build()
86: and huft_free() to end of file
87: c14u 1 Oct 95 G. Roelofs moved G into definition of MESSAGE macro
88: c14v 8 Nov 95 P. Kienitz changed ASM_INFLATECODES to use a regular
89: call with __G__ instead of a macro
90: c15 3 Aug 96 M. Adler fixed bomb-bug on random input data (Adobe)
91: c15b 24 Aug 96 M. Adler more fixes for random input data
92: c15c 28 Mar 97 G. Roelofs changed USE_ZLIB fatal exit code from
93: PK_MEM2 to PK_MEM3
94: c16 20 Apr 97 J. Altman added memzero(v[]) in huft_build()
95: c16b 29 Mar 98 C. Spieler modified DLL code for slide redirection
96:
1.1.1.4 ! root 97: fork 12 Dec 07 Adapted for TrueCrypt
1.1 root 98: */
99:
100:
101: /*
102: Inflate deflated (PKZIP's method 8 compressed) data. The compression
103: method searches for as much of the current string of bytes (up to a
104: length of 258) in the previous 32K bytes. If it doesn't find any
105: matches (of at least length 3), it codes the next byte. Otherwise, it
106: codes the length of the matched string and its distance backwards from
107: the current position. There is a single Huffman code that codes both
108: single bytes (called "literals") and match lengths. A second Huffman
109: code codes the distance information, which follows a length code. Each
110: length or distance code actually represents a base value and a number
111: of "extra" (sometimes zero) bits to get to add to the base value. At
112: the end of each deflated block is a special end-of-block (EOB) literal/
113: length code. The decoding process is basically: get a literal/length
114: code; if EOB then done; if a literal, emit the decoded byte; if a
115: length then get the distance and emit the referred-to bytes from the
116: sliding window of previously emitted data.
117:
118: There are (currently) three kinds of inflate blocks: stored, fixed, and
119: dynamic. The compressor outputs a chunk of data at a time and decides
120: which method to use on a chunk-by-chunk basis. A chunk might typically
121: be 32K to 64K, uncompressed. If the chunk is uncompressible, then the
122: "stored" method is used. In this case, the bytes are simply stored as
123: is, eight bits per byte, with none of the above coding. The bytes are
124: preceded by a count, since there is no longer an EOB code.
125:
126: If the data are compressible, then either the fixed or dynamic methods
127: are used. In the dynamic method, the compressed data are preceded by
128: an encoding of the literal/length and distance Huffman codes that are
129: to be used to decode this block. The representation is itself Huffman
130: coded, and so is preceded by a description of that code. These code
131: descriptions take up a little space, and so for small blocks, there is
132: a predefined set of codes, called the fixed codes. The fixed method is
133: used if the block ends up smaller that way (usually for quite small
134: chunks); otherwise the dynamic method is used. In the latter case, the
135: codes are customized to the probabilities in the current block and so
136: can code it much better than the pre-determined fixed codes can.
137:
138: The Huffman codes themselves are decoded using a multi-level table
139: lookup, in order to maximize the speed of decoding plus the speed of
140: building the decoding tables. See the comments below that precede the
141: lbits and dbits tuning parameters.
142:
143: GRR: return values(?)
144: 0 OK
145: 1 incomplete table
146: 2 bad input
147: 3 not enough memory
148: */
149:
150:
151: /*
152: Notes beyond the 1.93a appnote.txt:
153:
154: 1. Distance pointers never point before the beginning of the output
155: stream.
156: 2. Distance pointers can point back across blocks, up to 32k away.
157: 3. There is an implied maximum of 7 bits for the bit length table and
158: 15 bits for the actual data.
159: 4. If only one code exists, then it is encoded using one bit. (Zero
160: would be more efficient, but perhaps a little confusing.) If two
161: codes exist, they are coded using one bit each (0 and 1).
162: 5. There is no way of sending zero distance codes--a dummy must be
163: sent if there are none. (History: a pre 2.0 version of PKZIP would
164: store blocks with no distance codes, but this was discovered to be
165: too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
166: zero distance codes, which is sent as one code of zero bits in
167: length.
168: 6. There are up to 286 literal/length codes. Code 256 represents the
169: end-of-block. Note however that the static length tree defines
170: 288 codes just to fill out the Huffman codes. Codes 286 and 287
171: cannot be used though, since there is no length base or extra bits
172: defined for them. Similarily, there are up to 30 distance codes.
173: However, static trees define 32 codes (all 5 bits) to fill out the
174: Huffman codes, but the last two had better not show up in the data.
175: 7. Unzip can check dynamic Huffman blocks for complete code sets.
176: The exception is that a single code would not be complete (see #4).
177: 8. The five bits following the block type is really the number of
178: literal codes sent minus 257.
179: 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
180: (1+6+6). Therefore, to output three times the length, you output
181: three codes (1+1+1), whereas to output four times the same length,
182: you only need two codes (1+3). Hmm.
183: 10. In the tree reconstruction algorithm, Code = Code + Increment
184: only if BitLength(i) is not zero. (Pretty obvious.)
185: 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
186: 12. Note: length code 284 can represent 227-258, but length code 285
187: really is 258. The last length deserves its own, short code
188: since it gets used a lot in very redundant files. The length
189: 258 is special since 258 - 3 (the min match length) is 255.
190: 13. The literal/length and distance code bit lengths are read as a
191: single stream of lengths. It is possible (and advantageous) for
192: a repeat code (16, 17, or 18) to go across the boundary between
193: the two sets of lengths.
194: */
195:
196:
197: /* #define DEBUG */
198: #define INFMOD /* tell inflate.h to include code to be compiled */
199: #include "inflate.h"
200:
201:
202: #ifndef WSIZE /* default is 32K */
203: # define WSIZE 0x8000 /* window size--must be a power of two, and at least */
204: #endif /* 32K for zip's deflate method */
205:
206: #if (defined(DLL) && !defined(NO_SLIDE_REDIR))
207: # define wsize G._wsize /* wsize is a variable */
208: #else
209: # define wsize WSIZE /* wsize is a constant */
210: #endif
211:
212:
213: #ifndef NEXTBYTE /* default is to simply get a byte from stdin */
214: # define NEXTBYTE getchar()
215: #endif
216:
217: #ifndef MESSAGE /* only used twice, for fixed strings--NOT general-purpose */
218: # define MESSAGE(str,len,flag) fprintf(stderr,(char *)(str))
219: #endif
220:
221: #ifndef FLUSH /* default is to simply write the buffer to stdout */
222: # define FLUSH(n) fwrite(redirSlide, 1, n, stdout) /* return value not used */
223: #endif
224: /* Warning: the fwrite above might not work on 16-bit compilers, since
225: 0x8000 might be interpreted as -32,768 by the library function. */
226:
227: #ifndef Trace
228: # ifdef DEBUG
229: # define Trace(x) fprintf x
230: # else
231: # define Trace(x)
232: # endif
233: #endif
234:
235: G_struct G;
236: uch redirSlide [WSIZE];
237:
238: /*---------------------------------------------------------------------------*/
239: #ifdef USE_ZLIB
240:
241:
242: /*
243: GRR: return values for both original inflate() and inflate()
244: 0 OK
245: 1 incomplete table(?)
246: 2 bad input
247: 3 not enough memory
248: */
249:
250: /**************************/
251: /* Function inflate() */
252: /**************************/
253:
254: int inflate(__G) /* decompress an inflated entry using the zlib routines */
255: __GDEF
256: {
257: int err=Z_OK;
258:
259: #if (defined(DLL) && !defined(NO_SLIDE_REDIR))
260: if (G.redirect_slide)
261: wsize = G.redirect_size, redirSlide = G.redirect_buffer;
262: else
263: wsize = WSIZE, redirSlide = slide;
264: #endif
265:
266: G.dstrm.next_out = redirSlide;
267: G.dstrm.avail_out = wsize;
268:
269: G.dstrm.next_in = G.inptr;
270: G.dstrm.avail_in = G.incnt;
271:
272: if (!G.inflInit) {
273: unsigned i;
274: int windowBits;
275:
276: /* only need to test this stuff once */
277: if (zlib_version[0] != ZLIB_VERSION[0]) {
278: Info(slide, 0x21, ((char *)slide,
279: "error: incompatible zlib version (expected %s, found %s)\n",
280: ZLIB_VERSION, zlib_version));
281: return 3;
282: } else if (strcmp(zlib_version, ZLIB_VERSION) != 0)
283: Info(slide, 0x21, ((char *)slide,
284: "warning: different zlib version (expected %s, using %s)\n",
285: ZLIB_VERSION, zlib_version));
286:
287: /* windowBits = log2(wsize) */
288: for (i = ((unsigned)wsize * 2 - 1), windowBits = 0;
289: !(i & 1); i >>= 1, ++windowBits);
290: if ((unsigned)windowBits > (unsigned)15)
291: windowBits = 15;
292: else if (windowBits < 8)
293: windowBits = 8;
294:
295: G.dstrm.zalloc = (alloc_func)Z_NULL;
296: G.dstrm.zfree = (free_func)Z_NULL;
297:
298: Trace((stderr, "initializing inflate()\n"));
299: err = inflateInit2(&G.dstrm, -windowBits);
300:
301: if (err == Z_MEM_ERROR)
302: return 3;
303: else if (err != Z_OK)
304: Trace((stderr, "oops! (inflateInit2() err = %d)\n", err));
305: G.inflInit = 1;
306: }
307:
308: #ifdef FUNZIP
309: while (err != Z_STREAM_END) {
310: #else /* !FUNZIP */
311: while (G.csize > 0) {
312: Trace((stderr, "first loop: G.csize = %ld\n", G.csize));
313: #endif /* ?FUNZIP */
314: while (G.dstrm.avail_out > 0) {
315: err = inflate(&G.dstrm, Z_PARTIAL_FLUSH);
316:
317: if (err == Z_DATA_ERROR)
318: return 2;
319: else if (err == Z_MEM_ERROR)
320: return 3;
321: else if (err != Z_OK && err != Z_STREAM_END)
322: Trace((stderr, "oops! (inflate(first loop) err = %d)\n", err));
323:
324: #ifdef FUNZIP
325: if (err == Z_STREAM_END) /* "END-of-entry-condition" ? */
326: #else /* !FUNZIP */
327: if (G.csize <= 0L) /* "END-of-entry-condition" ? */
328: #endif /* ?FUNZIP */
329: break;
330:
331: if (G.dstrm.avail_in <= 0) {
332: if (fillinbuf(__G) == 0)
333: return 2; /* no "END-condition" yet, but no more data */
334:
335: G.dstrm.next_in = G.inptr;
336: G.dstrm.avail_in = G.incnt;
337: }
338: Trace((stderr, " avail_in = %d\n", G.dstrm.avail_in));
339: }
340: FLUSH(wsize - G.dstrm.avail_out); /* flush slide[] */
341: Trace((stderr, "inside loop: flushing %ld bytes (ptr diff = %ld)\n",
342: (long)(wsize - G.dstrm.avail_out),
343: (long)(G.dstrm.next_out-(Bytef *)redirSlide)));
344: G.dstrm.next_out = redirSlide;
345: G.dstrm.avail_out = wsize;
346: }
347:
348: /* no more input, so loop until we have all output */
349: Trace((stderr, "beginning final loop: err = %d\n", err));
350: while (err != Z_STREAM_END) {
351: err = inflate(&G.dstrm, Z_PARTIAL_FLUSH);
352: if (err == Z_DATA_ERROR)
353: return 2;
354: else if (err == Z_MEM_ERROR)
355: return 3;
356: else if (err == Z_BUF_ERROR) { /* DEBUG */
357: Trace((stderr, "zlib inflate() did not detect stream end (%s, %s)\n"
358: , G.zipfn, G.filename));
359: break;
360: } else if (err != Z_OK && err != Z_STREAM_END) {
361: Trace((stderr, "oops! (inflate(final loop) err = %d)\n", err));
362: DESTROYGLOBALS()
363: EXIT(PK_MEM3);
364: }
365: FLUSH(wsize - G.dstrm.avail_out); /* final flush of slide[] */
366: Trace((stderr, "final loop: flushing %ld bytes (ptr diff = %ld)\n",
367: (long)(wsize - G.dstrm.avail_out),
368: (long)(G.dstrm.next_out-(Bytef *)redirSlide)));
369: G.dstrm.next_out = redirSlide;
370: G.dstrm.avail_out = wsize;
371: }
372: Trace((stderr, "total in = %ld, total out = %ld\n", G.dstrm.total_in,
373: G.dstrm.total_out));
374:
375: G.inptr = (uch *)G.dstrm.next_in;
376: G.incnt = (G.inbuf + INBUFSIZ) - G.inptr; /* reset for other routines */
377:
378: err = inflateReset(&G.dstrm);
379: if (err != Z_OK)
380: Trace((stderr, "oops! (inflateReset() err = %d)\n", err));
381:
382: return 0;
383: }
384:
385:
386: /*---------------------------------------------------------------------------*/
387: #else /* !USE_ZLIB */
388:
389:
390: /* Function prototypes */
391: #ifndef OF
392: # ifdef __STDC__
393: # define OF(a) a
394: # else
395: # define OF(a) ()
396: # endif
397: #endif /* !OF */
398: int inflate_codes OF((__GPRO__ struct huft *tl, struct huft *td,
399: int bl, int bd));
400: static int inflate_stored OF((__GPRO));
401: static int inflate_fixed OF((__GPRO));
402: static int inflate_dynamic OF((__GPRO));
403: static int inflate_block OF((__GPRO__ int *e));
404:
405:
406: /* The inflate algorithm uses a sliding 32K byte window on the uncompressed
407: stream to find repeated byte strings. This is implemented here as a
408: circular buffer. The index is updated simply by incrementing and then
409: and'ing with 0x7fff (32K-1). */
410: /* It is left to other modules to supply the 32K area. It is assumed
411: to be usable as if it were declared "uch slide[32768];" or as just
412: "uch *slide;" and then malloc'ed in the latter case. The definition
413: must be in unzip.h, included above. */
414:
415:
416: /* unsigned wp; moved to globals.h */ /* current position in slide */
417:
418:
419: /* Tables for deflate from PKZIP's appnote.txt. */
420: static ZCONST unsigned border[] = { /* Order of the bit length code lengths */
421: 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
422: static ZCONST ush cplens[] = { /* Copy lengths for literal codes 257..285 */
423: 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
424: 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
425: /* note: see note #13 above about the 258 in this list. */
426: static ZCONST ush cplext[] = { /* Extra bits for literal codes 257..285 */
427: 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
428: 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */
429: static ZCONST ush cpdist[] = { /* Copy offsets for distance codes 0..29 */
430: 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
431: 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
432: 8193, 12289, 16385, 24577};
433: static ZCONST ush cpdext[] = { /* Extra bits for distance codes */
434: 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
435: 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
436: 12, 12, 13, 13};
437:
438:
439: /* moved to consts.h (included in unzip.c), resp. funzip.c */
440: #if 1
441: /* And'ing with mask_bits[n] masks the lower n bits */
442: ZCONST ush near mask_bits[] = {
443: 0x0000,
444: 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
445: 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
446: };
447: #endif /* 0 */
448:
449:
450: /* Macros for inflate() bit peeking and grabbing.
451: The usage is:
452:
453: NEEDBITS(j)
454: x = b & mask_bits[j];
455: DUMPBITS(j)
456:
457: where NEEDBITS makes sure that b has at least j bits in it, and
458: DUMPBITS removes the bits from b. The macros use the variable k
459: for the number of bits in b. Normally, b and k are register
460: variables for speed and are initialized at the begining of a
461: routine that uses these macros from a global bit buffer and count.
462:
463: In order to not ask for more bits than there are in the compressed
464: stream, the Huffman tables are constructed to only ask for just
465: enough bits to make up the end-of-block code (value 256). Then no
466: bytes need to be "returned" to the buffer at the end of the last
467: block. See the huft_build() routine.
468: */
469:
470: /* These have been moved to globals.h */
471: #if 0
472: ulg bb; /* bit buffer */
473: unsigned bk; /* bits in bit buffer */
474: #endif
475:
476: #ifndef CHECK_EOF
477: # define CHECK_EOF /* default as of 5.13/5.2 */
478: #endif
479:
480: #ifndef CHECK_EOF
481: # define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE)<<k;k+=8;}}
482: #else
483: # define NEEDBITS(n) {while(k<(n)){int c=NEXTBYTE;if(c==EOF)return 1;\
484: b|=((ulg)c)<<k;k+=8;}}
485: #endif /* Piet Plomp: change "return 1" to "break" */
486:
487: #define DUMPBITS(n) {b>>=(n);k-=(n);}
488:
489:
490: /*
491: Huffman code decoding is performed using a multi-level table lookup.
492: The fastest way to decode is to simply build a lookup table whose
493: size is determined by the longest code. However, the time it takes
494: to build this table can also be a factor if the data being decoded
495: are not very long. The most common codes are necessarily the
496: shortest codes, so those codes dominate the decoding time, and hence
497: the speed. The idea is you can have a shorter table that decodes the
498: shorter, more probable codes, and then point to subsidiary tables for
499: the longer codes. The time it costs to decode the longer codes is
500: then traded against the time it takes to make longer tables.
501:
502: This results of this trade are in the variables lbits and dbits
503: below. lbits is the number of bits the first level table for literal/
504: length codes can decode in one step, and dbits is the same thing for
505: the distance codes. Subsequent tables are also less than or equal to
506: those sizes. These values may be adjusted either when all of the
507: codes are shorter than that, in which case the longest code length in
508: bits is used, or when the shortest code is *longer* than the requested
509: table size, in which case the length of the shortest code in bits is
510: used.
511:
512: There are two different values for the two tables, since they code a
513: different number of possibilities each. The literal/length table
514: codes 286 possible values, or in a flat code, a little over eight
515: bits. The distance table codes 30 possible values, or a little less
516: than five bits, flat. The optimum values for speed end up being
517: about one bit more than those, so lbits is 8+1 and dbits is 5+1.
518: The optimum values may differ though from machine to machine, and
519: possibly even between compilers. Your mileage may vary.
520: */
521:
522: static ZCONST int lbits = 9; /* bits in base literal/length lookup table */
523: static ZCONST int dbits = 6; /* bits in base distance lookup table */
524:
525:
526: #ifndef ASM_INFLATECODES
527:
1.1.1.3 root 528: #pragma warning(disable:4131)
529:
1.1 root 530: int inflate_codes(__G__ tl, td, bl, bd)
531: __GDEF
532: struct huft *tl, *td; /* literal/length and distance decoder tables */
533: int bl, bd; /* number of bits decoded by tl[] and td[] */
534: /* inflate (decompress) the codes in a deflated (compressed) block.
535: Return an error code or zero if it all goes ok. */
536: {
537: register unsigned e; /* table entry flag/number of extra bits */
538: unsigned n, d; /* length and index for copy */
539: unsigned w; /* current window position */
540: struct huft *t; /* pointer to table entry */
541: unsigned ml, md; /* masks for bl and bd bits */
542: register ulg b; /* bit buffer */
543: register unsigned k; /* number of bits in bit buffer */
544:
545:
546: /* make local copies of globals */
547: b = G.bb; /* initialize bit buffer */
548: k = G.bk;
549: w = G.wp; /* initialize window position */
550:
551:
552: /* inflate the coded data */
553: ml = mask_bits[bl]; /* precompute masks for speed */
554: md = mask_bits[bd];
555: while (1) /* do until end of block */
556: {
557: NEEDBITS((unsigned)bl)
558: if ((e = (t = tl + ((unsigned)b & ml))->e) > 16)
559: do {
560: if (e == 99)
561: return 1;
562: DUMPBITS(t->b)
563: e -= 16;
564: NEEDBITS(e)
565: } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
566: DUMPBITS(t->b)
567: if (e == 16) /* then it's a literal */
568: {
569: redirSlide[w++] = (uch)t->v.n;
570: if (w == wsize)
571: {
572: FLUSH(w);
573: w = 0;
574: }
575: }
576: else /* it's an EOB or a length */
577: {
578: /* exit if end of block */
579: if (e == 15)
580: break;
581:
582: /* get length of block to copy */
583: NEEDBITS(e)
584: n = t->v.n + ((unsigned)b & mask_bits[e]);
585: DUMPBITS(e);
586:
587: /* decode distance of block to copy */
588: NEEDBITS((unsigned)bd)
589: if ((e = (t = td + ((unsigned)b & md))->e) > 16)
590: do {
591: if (e == 99)
592: return 1;
593: DUMPBITS(t->b)
594: e -= 16;
595: NEEDBITS(e)
596: } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
597: DUMPBITS(t->b)
598: NEEDBITS(e)
599: d = w - t->v.n - ((unsigned)b & mask_bits[e]);
600: DUMPBITS(e)
601:
602: /* do the copy */
603: do {
604: #if (defined(DLL) && !defined(NO_SLIDE_REDIR))
605: if (G.redirect_slide) {/* &= w/ wsize unnecessary & wrong if redirect */
606: if (d >= wsize)
607: return 1; /* invalid compressed data */
608: n -= (e = (e = wsize - (d > w ? d : w)) > n ? n : e);
609: }
610: else
611: #endif
612: n -= (e = (e = wsize - ((d &= wsize-1) > w ? d : w)) > n ? n : e);
613: #ifndef NOMEMCPY
614: if (w - d >= e) /* (this test assumes unsigned comparison) */
615: {
616: memcpy(redirSlide + w, redirSlide + d, e);
617: w += e;
618: d += e;
619: }
620: else /* do it slowly to avoid memcpy() overlap */
621: #endif /* !NOMEMCPY */
622: do {
623: redirSlide[w++] = redirSlide[d++];
624: } while (--e);
625: if (w == wsize)
626: {
627: FLUSH(w);
628: w = 0;
629: }
630: } while (n);
631: }
632: }
633:
634:
635: /* restore the globals from the locals */
636: G.wp = w; /* restore global window pointer */
637: G.bb = b; /* restore global bit buffer */
638: G.bk = k;
639:
640:
641: /* done */
642: return 0;
643: }
644:
645: #endif /* ASM_INFLATECODES */
646:
647:
648:
649: static int inflate_stored(__G)
650: __GDEF
651: /* "decompress" an inflated type 0 (stored) block. */
652: {
653: unsigned n; /* number of bytes in block */
654: unsigned w; /* current window position */
655: register ulg b; /* bit buffer */
656: register unsigned k; /* number of bits in bit buffer */
657:
658:
659: /* make local copies of globals */
660: Trace((stderr, "\nstored block"));
661: b = G.bb; /* initialize bit buffer */
662: k = G.bk;
663: w = G.wp; /* initialize window position */
664:
665:
666: /* go to byte boundary */
667: n = k & 7;
668: DUMPBITS(n);
669:
670:
671: /* get the length and its complement */
672: NEEDBITS(16)
673: n = ((unsigned)b & 0xffff);
674: DUMPBITS(16)
675: NEEDBITS(16)
676: if (n != (unsigned)((~b) & 0xffff))
677: return 1; /* error in compressed data */
678: DUMPBITS(16)
679:
680:
681: /* read and output the compressed data */
682: while (n--)
683: {
684: NEEDBITS(8)
685: redirSlide[w++] = (uch)b;
686: if (w == wsize)
687: {
688: FLUSH(w);
689: w = 0;
690: }
691: DUMPBITS(8)
692: }
693:
694:
695: /* restore the globals from the locals */
696: G.wp = w; /* restore global window pointer */
697: G.bb = b; /* restore global bit buffer */
698: G.bk = k;
699: return 0;
700: }
701:
702:
703: /* Globals for literal tables (built once) */
704: /* Moved to globals.h */
705: #if 0
706: struct huft *fixed_tl = (struct huft *)NULL;
707: struct huft *fixed_td;
708: int fixed_bl, fixed_bd;
709: #endif
710:
711: static int inflate_fixed(__G)
712: __GDEF
713: /* decompress an inflated type 1 (fixed Huffman codes) block. We should
714: either replace this with a custom decoder, or at least precompute the
715: Huffman tables. */
716: {
717: /* if first time, set up tables for fixed blocks */
718: Trace((stderr, "\nliteral block"));
719: if (G.fixed_tl == (struct huft *)NULL)
720: {
721: int i; /* temporary variable */
722: unsigned l[288]; /* length list for huft_build */
723:
724: /* literal table */
725: for (i = 0; i < 144; i++)
726: l[i] = 8;
727: for (; i < 256; i++)
728: l[i] = 9;
729: for (; i < 280; i++)
730: l[i] = 7;
731: for (; i < 288; i++) /* make a complete, but wrong code set */
732: l[i] = 8;
733: G.fixed_bl = 7;
734: if ((i = huft_build(__G__ l, 288, 257, cplens, cplext,
735: &G.fixed_tl, &G.fixed_bl)) != 0)
736: {
737: G.fixed_tl = (struct huft *)NULL;
738: return i;
739: }
740:
741: /* distance table */
742: for (i = 0; i < 30; i++) /* make an incomplete code set */
743: l[i] = 5;
744: G.fixed_bd = 5;
745: if ((i = huft_build(__G__ l, 30, 0, cpdist, cpdext,
746: &G.fixed_td, &G.fixed_bd)) > 1)
747: {
748: huft_free(G.fixed_tl);
749: G.fixed_tl = (struct huft *)NULL;
750: return i;
751: }
752: }
753:
754: /* decompress until an end-of-block code */
755: return inflate_codes(__G__ G.fixed_tl, G.fixed_td,
756: G.fixed_bl, G.fixed_bd) != 0;
757: }
758:
759:
760:
761: static int inflate_dynamic(__G)
762: __GDEF
763: /* decompress an inflated type 2 (dynamic Huffman codes) block. */
764: {
765: int i; /* temporary variables */
766: unsigned j;
767: unsigned l; /* last length */
768: unsigned m; /* mask for bit lengths table */
769: unsigned n; /* number of lengths to get */
770: struct huft *tl; /* literal/length code table */
771: struct huft *td; /* distance code table */
772: int bl; /* lookup bits for tl */
773: int bd; /* lookup bits for td */
774: unsigned nb; /* number of bit length codes */
775: unsigned nl; /* number of literal/length codes */
776: unsigned nd; /* number of distance codes */
777: #ifdef PKZIP_BUG_WORKAROUND
778: unsigned ll[288+32]; /* literal/length and distance code lengths */
779: #else
780: unsigned ll[286+30]; /* literal/length and distance code lengths */
781: #endif
782: register ulg b; /* bit buffer */
783: register unsigned k; /* number of bits in bit buffer */
784:
785:
786: /* make local bit buffer */
787: Trace((stderr, "\ndynamic block"));
788: b = G.bb;
789: k = G.bk;
790:
791:
792: /* read in table lengths */
793: NEEDBITS(5)
794: nl = 257 + ((unsigned)b & 0x1f); /* number of literal/length codes */
795: DUMPBITS(5)
796: NEEDBITS(5)
797: nd = 1 + ((unsigned)b & 0x1f); /* number of distance codes */
798: DUMPBITS(5)
799: NEEDBITS(4)
800: nb = 4 + ((unsigned)b & 0xf); /* number of bit length codes */
801: DUMPBITS(4)
802: #ifdef PKZIP_BUG_WORKAROUND
803: if (nl > 288 || nd > 32)
804: #else
805: if (nl > 286 || nd > 30)
806: #endif
807: return 1; /* bad lengths */
808:
809:
810: /* read in bit-length-code lengths */
811: for (j = 0; j < nb; j++)
812: {
813: NEEDBITS(3)
814: ll[border[j]] = (unsigned)b & 7;
815: DUMPBITS(3)
816: }
817: for (; j < 19; j++)
818: ll[border[j]] = 0;
819:
820:
821: /* build decoding table for trees--single level, 7 bit lookup */
822: bl = 7;
823: i = huft_build(__G__ ll, 19, 19, NULL, NULL, &tl, &bl);
824: if (bl == 0) /* no bit lengths */
825: i = 1;
826: if (i)
827: {
828: if (i == 1)
829: huft_free(tl);
830: return i; /* incomplete code set */
831: }
832:
833:
834: /* read in literal and distance code lengths */
835: n = nl + nd;
836: m = mask_bits[bl];
837: i = l = 0;
838: while ((unsigned)i < n)
839: {
840: NEEDBITS((unsigned)bl)
841: j = (td = tl + ((unsigned)b & m))->b;
842: DUMPBITS(j)
843: j = td->v.n;
844: if (j < 16) /* length of code in bits (0..15) */
845: ll[i++] = l = j; /* save last length in l */
846: else if (j == 16) /* repeat last length 3 to 6 times */
847: {
848: NEEDBITS(2)
849: j = 3 + ((unsigned)b & 3);
850: DUMPBITS(2)
851: if ((unsigned)i + j > n)
852: return 1;
853: while (j--)
854: ll[i++] = l;
855: }
856: else if (j == 17) /* 3 to 10 zero length codes */
857: {
858: NEEDBITS(3)
859: j = 3 + ((unsigned)b & 7);
860: DUMPBITS(3)
861: if ((unsigned)i + j > n)
862: return 1;
863: while (j--)
864: ll[i++] = 0;
865: l = 0;
866: }
867: else /* j == 18: 11 to 138 zero length codes */
868: {
869: NEEDBITS(7)
870: j = 11 + ((unsigned)b & 0x7f);
871: DUMPBITS(7)
872: if ((unsigned)i + j > n)
873: return 1;
874: while (j--)
875: ll[i++] = 0;
876: l = 0;
877: }
878: }
879:
880:
881: /* free decoding table for trees */
882: huft_free(tl);
883:
884:
885: /* restore the global bit buffer */
886: G.bb = b;
887: G.bk = k;
888:
889:
890: /* build the decoding tables for literal/length and distance codes */
891: bl = lbits;
892: i = huft_build(__G__ ll, nl, 257, cplens, cplext, &tl, &bl);
893: if (bl == 0) /* no literals or lengths */
894: i = 1;
895: if (i)
896: {
897: if (i == 1) {
898: //if (!uO.qflag)
899: MESSAGE((uch *)"(incomplete l-tree) ", 21L, 1);
900: huft_free(tl);
901: }
902: return i; /* incomplete code set */
903: }
904: bd = dbits;
905: i = huft_build(__G__ ll + nl, nd, 0, cpdist, cpdext, &td, &bd);
906: if (bd == 0 && nl > 257) /* lengths but no distances */
907: {
908: //if (!uO.qflag)
909: MESSAGE((uch *)"(incomplete d-tree) ", 21L, 1);
910: huft_free(tl);
911: return 1;
912: }
913: if (i == 1) {
914: #ifdef PKZIP_BUG_WORKAROUND
915: i = 0;
916: #else
917: //if (!uO.qflag)
918: MESSAGE((uch *)"(incomplete d-tree) ", 21L, 1);
919: huft_free(td);
920: #endif
921: }
922: if (i)
923: {
924: huft_free(tl);
925: return i;
926: }
927:
928:
929: /* decompress until an end-of-block code */
930: if (inflate_codes(__G__ tl, td, bl, bd))
931: return 1;
932:
933:
934: /* free the decoding tables, return */
935: huft_free(tl);
936: huft_free(td);
937: return 0;
938: }
939:
940:
941:
942: static int inflate_block(__G__ e)
943: __GDEF
944: int *e; /* last block flag */
945: /* decompress an inflated block */
946: {
947: unsigned t; /* block type */
948: register ulg b; /* bit buffer */
949: register unsigned k; /* number of bits in bit buffer */
950:
951:
952: /* make local bit buffer */
953: b = G.bb;
954: k = G.bk;
955:
956:
957: /* read in last block bit */
958: NEEDBITS(1)
959: *e = (int)b & 1;
960: DUMPBITS(1)
961:
962:
963: /* read in block type */
964: NEEDBITS(2)
965: t = (unsigned)b & 3;
966: DUMPBITS(2)
967:
968:
969: /* restore the global bit buffer */
970: G.bb = b;
971: G.bk = k;
972:
973:
974: /* inflate that block type */
975: if (t == 2)
976: return inflate_dynamic(__G);
977: if (t == 0)
978: return inflate_stored(__G);
979: if (t == 1)
980: return inflate_fixed(__G);
981:
982:
983: /* bad block type */
984: return 2;
985: }
986:
987:
988:
989: int inflate(__G)
990: __GDEF
991: /* decompress an inflated entry */
992: {
993: int e; /* last block flag */
994: int r; /* result code */
1.1.1.2 root 995: //#ifdef DEBUG
996: // unsigned h = 0; /* maximum struct huft's malloc'ed */
997: //#endif
1.1 root 998:
999: #if (defined(DLL) && !defined(NO_SLIDE_REDIR))
1000: if (G.redirect_slide)
1001: wsize = G.redirect_size, redirSlide = G.redirect_buffer;
1002: else
1003: wsize = WSIZE, redirSlide = slide; /* how they're #defined if !DLL */
1004: #endif
1005:
1006: /* initialize window, bit buffer */
1007: G.wp = 0;
1008: G.bk = 0;
1009: G.bb = 0;
1010:
1011:
1012: /* decompress until the last block */
1013: do {
1.1.1.2 root 1014: //#ifdef DEBUG
1015: // G.hufts = 0;
1016: //#endif
1.1 root 1017: if ((r = inflate_block(__G__ &e)) != 0)
1018: return r;
1.1.1.2 root 1019: //#ifdef DEBUG
1020: // if (G.hufts > h)
1021: // h = G.hufts;
1022: //#endif
1.1 root 1023: } while (!e);
1024:
1025:
1026: /* flush out redirSlide */
1027: FLUSH(G.wp);
1028:
1029:
1030: /* return success */
1.1.1.2 root 1031: //Trace((stderr, "\n%u bytes in Huffman tables (%d/entry)\n",
1032: // h * sizeof(struct huft), sizeof(struct huft)));
1.1 root 1033: return 0;
1034: }
1035:
1036:
1037:
1038: int inflate_free(__G)
1039: __GDEF
1040: {
1041: if (G.fixed_tl != (struct huft *)NULL)
1042: {
1043: huft_free(G.fixed_td);
1044: huft_free(G.fixed_tl);
1045: G.fixed_td = G.fixed_tl = (struct huft *)NULL;
1046: }
1047: return 0;
1048: }
1049:
1050: #endif /* ?USE_ZLIB */
1051:
1052:
1053: /*
1054: * GRR: moved huft_build() and huft_free() down here; used by explode()
1055: * and fUnZip regardless of whether USE_ZLIB defined or not
1056: */
1057:
1058:
1059: /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
1060: #define BMAX 16 /* maximum bit length of any code (16 for explode) */
1061: #define N_MAX 288 /* maximum number of codes in any set */
1062:
1063:
1064: int huft_build(
1065: __GDEF
1066: ZCONST unsigned *b, /* code lengths in bits (all assumed <= BMAX) */
1067: unsigned n, /* number of codes (assumed <= N_MAX) */
1068: unsigned s, /* number of simple-valued codes (0..s-1) */
1069: ZCONST ush *d, /* list of base values for non-simple codes */
1070: ZCONST ush *e, /* list of extra bits for non-simple codes */
1071: struct huft **t, /* result: starting table */
1072: int *m /* maximum lookup bits, returns actual */
1073: )
1074: /* Given a list of code lengths and a maximum table size, make a set of
1075: tables to decode that set of codes. Return zero on success, one if
1076: the given code set is incomplete (the tables are still built in this
1077: case), two if the input is invalid (all zero length codes or an
1078: oversubscribed set of lengths), and three if not enough memory.
1079: The code with value 256 is special, and the tables are constructed
1080: so that no bits beyond that code are fetched when that code is
1081: decoded. */
1082: {
1083: unsigned a; /* counter for codes of length k */
1084: unsigned c[BMAX+1]; /* bit length count table */
1085: unsigned el; /* length of EOB code (value 256) */
1086: unsigned f; /* i repeats in table every f entries */
1087: int g; /* maximum code length */
1088: int h; /* table level */
1089: register unsigned i; /* counter, current code */
1090: register unsigned j; /* counter */
1091: register int k; /* number of bits in current code */
1092: int lx[BMAX+1]; /* memory for l[-1..BMAX-1] */
1093: int *l = lx+1; /* stack of bits per table */
1094: register unsigned *p; /* pointer into c[], b[], or v[] */
1095: register struct huft *q; /* points to current table */
1096: struct huft r; /* table entry for structure assignment */
1097: struct huft *u[BMAX]; /* table stack */
1098: unsigned v[N_MAX]; /* values in order of bit length */
1099: register int w; /* bits before this table == (l * h) */
1100: unsigned x[BMAX+1]; /* bit offsets, then code stack */
1101: unsigned *xp; /* pointer into x */
1102: int y; /* number of dummy codes added */
1103: unsigned z; /* number of entries in current table */
1104:
1105:
1106: /* Generate counts for each bit length */
1107: el = n > 256 ? b[256] : BMAX; /* set length of EOB code, if any */
1108: memset(c, 0, sizeof(c));
1109: p = (unsigned *)b; i = n;
1110: do {
1111: c[*p]++; p++; /* assume all entries <= BMAX */
1112: } while (--i);
1113: if (c[0] == n) /* null input--all zero length codes */
1114: {
1115: *t = (struct huft *)NULL;
1116: *m = 0;
1117: return 0;
1118: }
1119:
1120:
1121: /* Find minimum and maximum length, bound *m by those */
1122: for (j = 1; j <= BMAX; j++)
1123: if (c[j])
1124: break;
1125: k = j; /* minimum code length */
1126: if ((unsigned)*m < j)
1127: *m = j;
1128: for (i = BMAX; i; i--)
1129: if (c[i])
1130: break;
1131: g = i; /* maximum code length */
1132: if ((unsigned)*m > i)
1133: *m = i;
1134:
1135:
1136: /* Adjust last length count to fill out codes, if needed */
1137: for (y = 1 << j; j < i; j++, y <<= 1)
1138: if ((y -= c[j]) < 0)
1139: return 2; /* bad input: more codes than bits */
1140: if ((y -= c[i]) < 0)
1141: return 2;
1142: c[i] += y;
1143:
1144:
1145: /* Generate starting offsets into the value table for each length */
1146: x[1] = j = 0;
1147: p = c + 1; xp = x + 2;
1148: while (--i) { /* note that i == g from above */
1149: *xp++ = (j += *p++);
1150: }
1151:
1152:
1153: /* Make a table of values in order of bit lengths */
1154: memset(v, 0, sizeof(v));
1155: p = (unsigned *)b; i = 0;
1156: do {
1157: if ((j = *p++) != 0)
1158: v[x[j]++] = i;
1159: } while (++i < n);
1160: n = x[g]; /* set n to length of v */
1161:
1162:
1163: /* Generate the Huffman codes and for each, make the table entries */
1164: x[0] = i = 0; /* first Huffman code is zero */
1165: p = v; /* grab values in bit order */
1166: h = -1; /* no tables yet--level -1 */
1167: w = l[-1] = 0; /* no bits decoded yet */
1168: u[0] = (struct huft *)NULL; /* just to keep compilers happy */
1169: q = (struct huft *)NULL; /* ditto */
1170: z = 0; /* ditto */
1171:
1172: /* go through the bit lengths (k already is bits in shortest code) */
1173: for (; k <= g; k++)
1174: {
1175: a = c[k];
1176: while (a--)
1177: {
1178: /* here i is the Huffman code of length k bits for value *p */
1179: /* make tables up to required level */
1180: while (k > w + l[h])
1181: {
1182: w += l[h++]; /* add bits already decoded */
1183:
1184: /* compute minimum size table less than or equal to *m bits */
1185: z = (z = g - w) > (unsigned)*m ? *m : z; /* upper limit */
1186: if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
1187: { /* too few codes for k-w bit table */
1188: f -= a + 1; /* deduct codes from patterns left */
1189: xp = c + k;
1190: while (++j < z) /* try smaller tables up to z bits */
1191: {
1192: if ((f <<= 1) <= *++xp)
1193: break; /* enough codes to use up j bits */
1194: f -= *xp; /* else deduct codes from patterns */
1195: }
1196: }
1197: if ((unsigned)w + j > el && (unsigned)w < el)
1198: j = el - w; /* make EOB code end at table */
1199: z = 1 << j; /* table entries for j-bit table */
1200: l[h] = j; /* set table size in stack */
1201:
1202: /* allocate and link in new table */
1203: if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
1204: (struct huft *)NULL)
1205: {
1206: if (h)
1207: huft_free(u[0]);
1208: return 3; /* not enough memory */
1209: }
1.1.1.2 root 1210: //#ifdef DEBUG
1211: // G.hufts += z + 1; /* track memory usage */
1212: //#endif
1.1 root 1213: *t = q + 1; /* link to list for huft_free() */
1214: *(t = &(q->v.t)) = (struct huft *)NULL;
1215: u[h] = ++q; /* table starts after link */
1216:
1217: /* connect to last table, if there is one */
1218: if (h)
1219: {
1220: x[h] = i; /* save pattern for backing up */
1221: r.b = (uch)l[h-1]; /* bits to dump before this table */
1222: r.e = (uch)(16 + j); /* bits in this table */
1223: r.v.t = q; /* pointer to this table */
1224: j = (i & ((1 << w) - 1)) >> (w - l[h-1]);
1225: u[h-1][j] = r; /* connect to last table */
1226: }
1227: }
1228:
1229: /* set up table entry in r */
1230: r.b = (uch)(k - w);
1231: if (p >= v + n)
1232: r.e = 99; /* out of values--invalid code */
1233: else if (*p < s)
1234: {
1235: r.e = (uch)(*p < 256 ? 16 : 15); /* 256 is end-of-block code */
1236: r.v.n = (ush)*p++; /* simple code is just the value */
1237: }
1238: else
1239: {
1240: r.e = (uch)e[*p - s]; /* non-simple--look up in lists */
1241: r.v.n = d[*p++ - s];
1242: }
1243:
1244: /* fill code-like entries with r */
1245: f = 1 << (k - w);
1246: for (j = i >> w; j < z; j += f)
1247: q[j] = r;
1248:
1249: /* backwards increment the k-bit code i */
1250: for (j = 1 << (k - 1); i & j; j >>= 1)
1251: i ^= j;
1252: i ^= j;
1253:
1254: /* backup over finished tables */
1255: while ((i & ((1 << w) - 1)) != x[h])
1256: w -= l[--h]; /* don't need to update q */
1257: }
1258: }
1259:
1260:
1261: /* return actual size of base table */
1262: *m = l[0];
1263:
1264:
1265: /* Return true (1) if we were given an incomplete table */
1266: return y != 0 && g != 1;
1267: }
1268:
1269:
1270:
1271: int huft_free (struct huft *t)
1272: /* table to free */
1273: /* Free the malloc'ed tables built by huft_build(), which makes a linked
1274: list of the tables it made, with the links in a dummy first entry of
1275: each table. */
1276: {
1277: register struct huft *p, *q;
1278:
1279:
1280: /* Go through linked list, freeing from the malloced (t[-1]) address. */
1281: p = t;
1282: while (p != (struct huft *)NULL)
1283: {
1284: q = (--p)->v.t;
1285: free((zvoid *)p);
1286: p = q;
1287: }
1288: return 0;
1289: }
1290:
1291:
1292: // Main public function. Decompresses raw data compressed using the DEFLATE algorithm (RFC 1951 - e.g. zlib, gzip).
1293: // Returns 0 if decompression fails or, if successful, returns the size of the decompressed data.
1294: int DecompressDeflatedData (char *out, char *in, int inLength)
1295: {
1296: G.outbufptr = out;
1297: G.inptr = in;
1298: G.incnt = inLength;
1299: G.outCounter = 0;
1300:
1301: if (inflate(__G) != 0)
1302: {
1303: // Error decompressing
1304: return 0;
1305: }
1306: return G.outCounter;
1307: }
1308:
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.