1 /* inflate.c -- Not copyrighted 1992 by Mark Adler
2 * version c10p1, 10 January 1993
4 * $FreeBSD: src/gnu/usr.bin/gzip/inflate.c,v 1.8 1999/08/27 23:35:51 peter Exp $
5 * $DragonFly: src/gnu/usr.bin/gzip/Attic/inflate.c,v 1.2 2003/06/17 04:25:46 dillon Exp $
8 /* You can do whatever you like with this source file, though I would
9 prefer that if you modify it and redistribute it that you include
10 comments to that effect with your name and the date. Thank you.
11 [The history has been moved to the file ChangeLog.]
15 Inflate deflated (PKZIP's method 8 compressed) data. The compression
16 method searches for as much of the current string of bytes (up to a
17 length of 258) in the previous 32K bytes. If it doesn't find any
18 matches (of at least length 3), it codes the next byte. Otherwise, it
19 codes the length of the matched string and its distance backwards from
20 the current position. There is a single Huffman code that codes both
21 single bytes (called "literals") and match lengths. A second Huffman
22 code codes the distance information, which follows a length code. Each
23 length or distance code actually represents a base value and a number
24 of "extra" (sometimes zero) bits to get to add to the base value. At
25 the end of each deflated block is a special end-of-block (EOB) literal/
26 length code. The decoding process is basically: get a literal/length
27 code; if EOB then done; if a literal, emit the decoded byte; if a
28 length then get the distance and emit the referred-to bytes from the
29 sliding window of previously emitted data.
31 There are (currently) three kinds of inflate blocks: stored, fixed, and
32 dynamic. The compressor deals with some chunk of data at a time, and
33 decides which method to use on a chunk-by-chunk basis. A chunk might
34 typically be 32K or 64K. If the chunk is uncompressible, then the
35 "stored" method is used. In this case, the bytes are simply stored as
36 is, eight bits per byte, with none of the above coding. The bytes are
37 preceded by a count, since there is no longer an EOB code.
39 If the data is compressible, then either the fixed or dynamic methods
40 are used. In the dynamic method, the compressed data is preceded by
41 an encoding of the literal/length and distance Huffman codes that are
42 to be used to decode this block. The representation is itself Huffman
43 coded, and so is preceded by a description of that code. These code
44 descriptions take up a little space, and so for small blocks, there is
45 a predefined set of codes, called the fixed codes. The fixed method is
46 used if the block codes up smaller that way (usually for quite small
47 chunks), otherwise the dynamic method is used. In the latter case, the
48 codes are customized to the probabilities in the current block, and so
49 can code it much better than the pre-determined fixed codes.
51 The Huffman codes themselves are decoded using a mutli-level table
52 lookup, in order to maximize the speed of decoding plus the speed of
53 building the decoding tables. See the comments below that precede the
54 lbits and dbits tuning parameters.
59 Notes beyond the 1.93a appnote.txt:
61 1. Distance pointers never point before the beginning of the output
63 2. Distance pointers can point back across blocks, up to 32k away.
64 3. There is an implied maximum of 7 bits for the bit length table and
65 15 bits for the actual data.
66 4. If only one code exists, then it is encoded using one bit. (Zero
67 would be more efficient, but perhaps a little confusing.) If two
68 codes exist, they are coded using one bit each (0 and 1).
69 5. There is no way of sending zero distance codes--a dummy must be
70 sent if there are none. (History: a pre 2.0 version of PKZIP would
71 store blocks with no distance codes, but this was discovered to be
72 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
73 zero distance codes, which is sent as one code of zero bits in
75 6. There are up to 286 literal/length codes. Code 256 represents the
76 end-of-block. Note however that the static length tree defines
77 288 codes just to fill out the Huffman codes. Codes 286 and 287
78 cannot be used though, since there is no length base or extra bits
79 defined for them. Similarly, there are up to 30 distance codes.
80 However, static trees define 32 codes (all 5 bits) to fill out the
81 Huffman codes, but the last two had better not show up in the data.
82 7. Unzip can check dynamic Huffman blocks for complete code sets.
83 The exception is that a single code would not be complete (see #4).
84 8. The five bits following the block type is really the number of
85 literal codes sent minus 257.
86 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
87 (1+6+6). Therefore, to output three times the length, you output
88 three codes (1+1+1), whereas to output four times the same length,
89 you only need two codes (1+3). Hmm.
90 10. In the tree reconstruction algorithm, Code = Code + Increment
91 only if BitLength(i) is not zero. (Pretty obvious.)
92 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
93 12. Note: length code 284 can represent 227-258, but length code 285
94 really is 258. The last length deserves its own, short code
95 since it gets used a lot in very redundant files. The length
96 258 is special since 258 - 3 (the min match length) is 255.
97 13. The literal/length and distance code bit lengths are read as a
98 single stream of lengths. It is possible (and advantageous) for
99 a repeat code (16, 17, or 18) to go across the boundary between
100 the two sets of lengths.
103 #include <sys/types.h>
107 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
114 /* Huffman code lookup table entry--this entry is four bytes for machines
115 that have 16-bit pointers (e.g. PC's in the small or medium model).
116 Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
117 means that v is a literal, 16 < e < 32 means that v is a pointer to
118 the next table, which codes e - 16 bits, and lastly e == 99 indicates
119 an unused code. If a code with e == 99 is looked up, this implies an
120 error in the data. */
122 uch e; /* number of extra bits or operation */
123 uch b; /* number of bits in this code or subcode */
125 ush n; /* literal, length base, or distance base */
126 struct huft *t; /* pointer to next level of table */
131 /* Function prototypes */
132 int huft_build OF((unsigned *, unsigned, unsigned, ush *, ush *,
133 struct huft **, int *));
134 int huft_free OF((struct huft *));
135 int inflate_codes OF((struct huft *, struct huft *, int, int));
136 int inflate_stored OF((void));
137 int inflate_fixed OF((void));
138 int inflate_dynamic OF((void));
139 int inflate_block OF((int *));
140 int inflate OF((void));
143 /* The inflate algorithm uses a sliding 32K byte window on the uncompressed
144 stream to find repeated byte strings. This is implemented here as a
145 circular buffer. The index is updated simply by incrementing and then
146 and'ing with 0x7fff (32K-1). */
147 /* It is left to other modules to supply the 32K area. It is assumed
148 to be usable as if it were declared "uch slide[32768];" or as just
149 "uch *slide;" and then malloc'ed in the latter case. The definition
150 must be in unzip.h, included above. */
151 /* unsigned wp; current position in slide */
153 #define flush_output(w) (wp=(w),flush_window())
155 /* Tables for deflate from PKZIP's appnote.txt. */
156 static unsigned border[] = { /* Order of the bit length code lengths */
157 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
158 static ush cplens[] = { /* Copy lengths for literal codes 257..285 */
159 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
160 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
161 /* note: see note #13 above about the 258 in this list. */
162 static ush cplext[] = { /* Extra bits for literal codes 257..285 */
163 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
164 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */
165 static ush cpdist[] = { /* Copy offsets for distance codes 0..29 */
166 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
167 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
168 8193, 12289, 16385, 24577};
169 static ush cpdext[] = { /* Extra bits for distance codes */
170 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
171 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
176 /* Macros for inflate() bit peeking and grabbing.
180 x = b & mask_bits[j];
183 where NEEDBITS makes sure that b has at least j bits in it, and
184 DUMPBITS removes the bits from b. The macros use the variable k
185 for the number of bits in b. Normally, b and k are register
186 variables for speed, and are initialized at the beginning of a
187 routine that uses these macros from a global bit buffer and count.
189 If we assume that EOB will be the longest code, then we will never
190 ask for bits with NEEDBITS that are beyond the end of the stream.
191 So, NEEDBITS should not read any more bytes than are needed to
192 meet the request. Then no bytes need to be "returned" to the buffer
193 at the end of the last block.
195 However, this assumption is not true for fixed blocks--the EOB code
196 is 7 bits, but the other literal/length codes can be 8 or 9 bits.
197 (The EOB code is shorter than other codes because fixed blocks are
198 generally short. So, while a block always has an EOB, many other
199 literal/length codes have a significantly lower probability of
200 showing up at all.) However, by making the first table have a
201 lookup of seven bits, the EOB code will be found in that first
202 lookup, and so will not require that too many bits be pulled from
206 ulg bb; /* bit buffer */
207 unsigned bk; /* bits in bit buffer */
211 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
212 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
217 # define NEXTBYTE() \
218 (decrypt ? (cc = get_byte(), zdecode(cc), cc) : get_byte())
220 # define NEXTBYTE() (uch)get_byte()
222 #define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}}
223 #define DUMPBITS(n) {b>>=(n);k-=(n);}
227 Huffman code decoding is performed using a multi-level table lookup.
228 The fastest way to decode is to simply build a lookup table whose
229 size is determined by the longest code. However, the time it takes
230 to build this table can also be a factor if the data being decoded
231 is not very long. The most common codes are necessarily the
232 shortest codes, so those codes dominate the decoding time, and hence
233 the speed. The idea is you can have a shorter table that decodes the
234 shorter, more probable codes, and then point to subsidiary tables for
235 the longer codes. The time it costs to decode the longer codes is
236 then traded against the time it takes to make longer tables.
238 This results of this trade are in the variables lbits and dbits
239 below. lbits is the number of bits the first level table for literal/
240 length codes can decode in one step, and dbits is the same thing for
241 the distance codes. Subsequent tables are also less than or equal to
242 those sizes. These values may be adjusted either when all of the
243 codes are shorter than that, in which case the longest code length in
244 bits is used, or when the shortest code is *longer* than the requested
245 table size, in which case the length of the shortest code in bits is
248 There are two different values for the two tables, since they code a
249 different number of possibilities each. The literal/length table
250 codes 286 possible values, or in a flat code, a little over eight
251 bits. The distance table codes 30 possible values, or a little less
252 than five bits, flat. The optimum values for speed end up being
253 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
254 The optimum values may differ though from machine to machine, and
255 possibly even between compilers. Your mileage may vary.
259 int lbits = 9; /* bits in base literal/length lookup table */
260 int dbits = 6; /* bits in base distance lookup table */
263 /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
264 #define BMAX 16 /* maximum bit length of any code (16 for explode) */
265 #define N_MAX 288 /* maximum number of codes in any set */
268 unsigned hufts; /* track memory usage */
271 int huft_build(b, n, s, d, e, t, m)
272 unsigned *b; /* code lengths in bits (all assumed <= BMAX) */
273 unsigned n; /* number of codes (assumed <= N_MAX) */
274 unsigned s; /* number of simple-valued codes (0..s-1) */
275 ush *d; /* list of base values for non-simple codes */
276 ush *e; /* list of extra bits for non-simple codes */
277 struct huft **t; /* result: starting table */
278 int *m; /* maximum lookup bits, returns actual */
279 /* Given a list of code lengths and a maximum table size, make a set of
280 tables to decode that set of codes. Return zero on success, one if
281 the given code set is incomplete (the tables are still built in this
282 case), two if the input is invalid (all zero length codes or an
283 oversubscribed set of lengths), and three if not enough memory. */
285 unsigned a; /* counter for codes of length k */
286 unsigned c[BMAX+1]; /* bit length count table */
287 unsigned f; /* i repeats in table every f entries */
288 int g; /* maximum code length */
289 int h; /* table level */
290 register unsigned i; /* counter, current code */
291 register unsigned j; /* counter */
292 register int k; /* number of bits in current code */
293 int l; /* bits per table (returned in m) */
294 register unsigned *p; /* pointer into c[], b[], or v[] */
295 register struct huft *q; /* points to current table */
296 struct huft r; /* table entry for structure assignment */
297 struct huft *u[BMAX]; /* table stack */
298 unsigned v[N_MAX]; /* values in order of bit length */
299 register int w; /* bits before this table == (l * h) */
300 unsigned x[BMAX+1]; /* bit offsets, then code stack */
301 unsigned *xp; /* pointer into x */
302 int y; /* number of dummy codes added */
303 unsigned z; /* number of entries in current table */
306 /* Generate counts for each bit length */
307 memzero(c, sizeof(c));
310 Tracecv(*p, (stderr, (n-i >= ' ' && n-i <= '~' ? "%c %d\n" : "0x%x %d\n"),
312 c[*p]++; /* assume all entries <= BMAX */
313 p++; /* Can't combine with above line (Solaris bug) */
315 if (c[0] == n) /* null input--all zero length codes */
317 *t = (struct huft *)NULL;
323 /* Find minimum and maximum length, bound *m by those */
325 for (j = 1; j <= BMAX; j++)
328 k = j; /* minimum code length */
331 for (i = BMAX; i; i--)
334 g = i; /* maximum code length */
340 /* Adjust last length count to fill out codes, if needed */
341 for (y = 1 << j; j < i; j++, y <<= 1)
343 return 2; /* bad input: more codes than bits */
349 /* Generate starting offsets into the value table for each length */
351 p = c + 1; xp = x + 2;
352 while (--i) { /* note that i == g from above */
357 /* Make a table of values in order of bit lengths */
365 /* Generate the Huffman codes and for each, make the table entries */
366 x[0] = i = 0; /* first Huffman code is zero */
367 p = v; /* grab values in bit order */
368 h = -1; /* no tables yet--level -1 */
369 w = -l; /* bits decoded == (l * h) */
370 u[0] = (struct huft *)NULL; /* just to keep compilers happy */
371 q = (struct huft *)NULL; /* ditto */
374 /* go through the bit lengths (k already is bits in shortest code) */
380 /* here i is the Huffman code of length k bits for value *p */
381 /* make tables up to required level */
385 w += l; /* previous table always l bits */
387 /* compute minimum size table less than or equal to l bits */
388 z = (z = g - w) > (unsigned)l ? l : z; /* upper limit on table size */
389 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
390 { /* too few codes for k-w bit table */
391 f -= a + 1; /* deduct codes from patterns left */
393 while (++j < z) /* try smaller tables up to z bits */
395 if ((f <<= 1) <= *++xp)
396 break; /* enough codes to use up j bits */
397 f -= *xp; /* else deduct codes from patterns */
400 z = 1 << j; /* table entries for j-bit table */
402 /* allocate and link in new table */
403 if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
408 return 3; /* not enough memory */
410 hufts += z + 1; /* track memory usage */
411 *t = q + 1; /* link to list for huft_free() */
412 *(t = &(q->v.t)) = (struct huft *)NULL;
413 u[h] = ++q; /* table starts after link */
415 /* connect to last table, if there is one */
418 x[h] = i; /* save pattern for backing up */
419 r.b = (uch)l; /* bits to dump before this table */
420 r.e = (uch)(16 + j); /* bits in this table */
421 r.v.t = q; /* pointer to this table */
422 j = i >> (w - l); /* (get around Turbo C bug) */
423 u[h-1][j] = r; /* connect to last table */
427 /* set up table entry in r */
430 r.e = 99; /* out of values--invalid code */
433 r.e = (uch)(*p < 256 ? 16 : 15); /* 256 is end-of-block code */
434 r.v.n = (ush)(*p); /* simple code is just the value */
435 p++; /* one compiler does not like *p++ */
439 r.e = (uch)e[*p - s]; /* non-simple--look up in lists */
443 /* fill code-like entries with r */
445 for (j = i >> w; j < z; j += f)
448 /* backwards increment the k-bit code i */
449 for (j = 1 << (k - 1); i & j; j >>= 1)
453 /* backup over finished tables */
454 while ((i & ((1 << w) - 1)) != x[h])
456 h--; /* don't need to update q */
463 /* Return true (1) if we were given an incomplete table */
464 return y != 0 && g != 1;
470 struct huft *t; /* table to free */
471 /* Free the malloc'ed tables built by huft_build(), which makes a linked
472 list of the tables it made, with the links in a dummy first entry of
475 register struct huft *p, *q;
478 /* Go through linked list, freeing from the malloced (t[-1]) address. */
480 while (p != (struct huft *)NULL)
490 int inflate_codes(tl, td, bl, bd)
491 struct huft *tl, *td; /* literal/length and distance decoder tables */
492 int bl, bd; /* number of bits decoded by tl[] and td[] */
493 /* inflate (decompress) the codes in a deflated (compressed) block.
494 Return an error code or zero if it all goes ok. */
496 register unsigned e; /* table entry flag/number of extra bits */
497 unsigned n, d; /* length and index for copy */
498 unsigned w; /* current window position */
499 struct huft *t; /* pointer to table entry */
500 unsigned ml, md; /* masks for bl and bd bits */
501 register ulg b; /* bit buffer */
502 register unsigned k; /* number of bits in bit buffer */
505 /* make local copies of globals */
506 b = bb; /* initialize bit buffer */
508 w = wp; /* initialize window position */
510 /* inflate the coded data */
511 ml = mask_bits[bl]; /* precompute masks for speed */
513 for (;;) /* do until end of block */
515 NEEDBITS((unsigned)bl)
516 if ((e = (t = tl + ((unsigned)b & ml))->e) > 16)
523 } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
525 if (e == 16) /* then it's a literal */
527 slide[w++] = (uch)t->v.n;
528 Tracevv((stderr, "%c", slide[w-1]));
535 else /* it's an EOB or a length */
537 /* exit if end of block */
541 /* get length of block to copy */
543 n = t->v.n + ((unsigned)b & mask_bits[e]);
546 /* decode distance of block to copy */
547 NEEDBITS((unsigned)bd)
548 if ((e = (t = td + ((unsigned)b & md))->e) > 16)
555 } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
558 d = w - t->v.n - ((unsigned)b & mask_bits[e]);
560 Tracevv((stderr,"\\[%d,%d]", w-d, n));
564 n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);
565 #if !defined(NOMEMCPY) && !defined(DEBUG)
566 if (w - d >= e) /* (this test assumes unsigned comparison) */
568 memcpy(slide + w, slide + d, e);
572 else /* do it slow to avoid memcpy() overlap */
573 #endif /* !NOMEMCPY */
575 slide[w++] = slide[d++];
576 Tracevv((stderr, "%c", slide[w-1]));
588 /* restore the globals from the locals */
589 wp = w; /* restore global window pointer */
590 bb = b; /* restore global bit buffer */
600 /* "decompress" an inflated type 0 (stored) block. */
602 unsigned n; /* number of bytes in block */
603 unsigned w; /* current window position */
604 register ulg b; /* bit buffer */
605 register unsigned k; /* number of bits in bit buffer */
608 /* make local copies of globals */
609 b = bb; /* initialize bit buffer */
611 w = wp; /* initialize window position */
614 /* go to byte boundary */
619 /* get the length and its complement */
621 n = ((unsigned)b & 0xffff);
624 if (n != (unsigned)((~b) & 0xffff))
625 return 1; /* error in compressed data */
629 /* read and output the compressed data */
643 /* restore the globals from the locals */
644 wp = w; /* restore global window pointer */
645 bb = b; /* restore global bit buffer */
653 /* decompress an inflated type 1 (fixed Huffman codes) block. We should
654 either replace this with a custom decoder, or at least precompute the
657 int i; /* temporary variable */
658 struct huft *tl; /* literal/length code table */
659 struct huft *td; /* distance code table */
660 int bl; /* lookup bits for tl */
661 int bd; /* lookup bits for td */
662 unsigned l[288]; /* length list for huft_build */
665 /* set up literal table */
666 for (i = 0; i < 144; i++)
672 for (; i < 288; i++) /* make a complete, but wrong code set */
675 if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0)
679 /* set up distance table */
680 for (i = 0; i < 30; i++) /* make an incomplete code set */
683 if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1)
690 /* decompress until an end-of-block code */
691 if (inflate_codes(tl, td, bl, bd))
695 /* free the decoding tables, return */
703 int inflate_dynamic()
704 /* decompress an inflated type 2 (dynamic Huffman codes) block. */
706 int i; /* temporary variables */
708 unsigned l; /* last length */
709 unsigned m; /* mask for bit lengths table */
710 unsigned n; /* number of lengths to get */
711 struct huft *tl; /* literal/length code table */
712 struct huft *td; /* distance code table */
713 int bl; /* lookup bits for tl */
714 int bd; /* lookup bits for td */
715 unsigned nb; /* number of bit length codes */
716 unsigned nl; /* number of literal/length codes */
717 unsigned nd; /* number of distance codes */
718 #ifdef PKZIP_BUG_WORKAROUND
719 unsigned ll[288+32]; /* literal/length and distance code lengths */
721 unsigned ll[286+30]; /* literal/length and distance code lengths */
723 register ulg b; /* bit buffer */
724 register unsigned k; /* number of bits in bit buffer */
727 /* make local bit buffer */
732 /* read in table lengths */
734 nl = 257 + ((unsigned)b & 0x1f); /* number of literal/length codes */
737 nd = 1 + ((unsigned)b & 0x1f); /* number of distance codes */
740 nb = 4 + ((unsigned)b & 0xf); /* number of bit length codes */
742 #ifdef PKZIP_BUG_WORKAROUND
743 if (nl > 288 || nd > 32)
745 if (nl > 286 || nd > 30)
747 return 1; /* bad lengths */
750 /* read in bit-length-code lengths */
751 for (j = 0; j < nb; j++)
754 ll[border[j]] = (unsigned)b & 7;
761 /* build decoding table for trees--single level, 7 bit lookup */
763 if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)
767 return i; /* incomplete code set */
770 if (tl == NULL) /* Grrrhhh */
773 /* read in literal and distance code lengths */
777 while ((unsigned)i < n)
779 NEEDBITS((unsigned)bl)
780 j = (td = tl + ((unsigned)b & m))->b;
783 if (j < 16) /* length of code in bits (0..15) */
784 ll[i++] = l = j; /* save last length in l */
785 else if (j == 16) /* repeat last length 3 to 6 times */
788 j = 3 + ((unsigned)b & 3);
790 if ((unsigned)i + j > n)
795 else if (j == 17) /* 3 to 10 zero length codes */
798 j = 3 + ((unsigned)b & 7);
800 if ((unsigned)i + j > n)
806 else /* j == 18: 11 to 138 zero length codes */
809 j = 11 + ((unsigned)b & 0x7f);
811 if ((unsigned)i + j > n)
820 /* free decoding table for trees */
824 /* restore the global bit buffer */
829 /* build the decoding tables for literal/length and distance codes */
831 if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
834 fprintf(stderr, " incomplete literal tree\n");
837 return i; /* incomplete code set */
840 if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
843 fprintf(stderr, " incomplete distance tree\n");
844 #ifdef PKZIP_BUG_WORKAROUND
851 return i; /* incomplete code set */
856 /* decompress until an end-of-block code */
857 if (inflate_codes(tl, td, bl, bd))
861 /* free the decoding tables, return */
870 int *e; /* last block flag */
871 /* decompress an inflated block */
873 unsigned t; /* block type */
874 register ulg b; /* bit buffer */
875 register unsigned k; /* number of bits in bit buffer */
878 /* make local bit buffer */
883 /* read in last block bit */
889 /* read in block type */
895 /* restore the global bit buffer */
900 /* inflate that block type */
902 return inflate_dynamic();
904 return inflate_stored();
906 return inflate_fixed();
916 /* decompress an inflated entry */
918 int e; /* last block flag */
919 int r; /* result code */
920 unsigned h; /* maximum struct huft's malloc'ed */
923 /* initialize window, bit buffer */
929 /* decompress until the last block */
933 if ((r = inflate_block(&e)) != 0)
939 /* Undo too much lookahead. The next read will be byte aligned so we
940 * can discard unused bits in the last meaningful byte.
947 /* flush out slide */
953 fprintf(stderr, "<%u> ", h);