2 * This file is derived from various .h and .c files from the zlib-0.95
3 * distribution by Jean-loup Gailly and Mark Adler, with some additions
4 * by Paul Mackerras to aid in implementing Deflate compression and
5 * decompression for PPP packets. See zlib.h for conditions of
6 * distribution and use.
8 * Changes that have been made include:
9 * - changed functions not used outside this file to "local"
10 * - added minCompression parameter to deflateInit2
11 * - added Z_PACKET_FLUSH (see zlib.h for details)
12 * - added inflateIncomp
14 Copyright (C) 1995 Jean-loup Gailly and Mark Adler
16 This software is provided 'as-is', without any express or implied
17 warranty. In no event will the authors be held liable for any damages
18 arising from the use of this software.
20 Permission is granted to anyone to use this software for any purpose,
21 including commercial applications, and to alter it and redistribute it
22 freely, subject to the following restrictions:
24 1. The origin of this software must not be misrepresented; you must not
25 claim that you wrote the original software. If you use this software
26 in a product, an acknowledgment in the product documentation would be
27 appreciated but is not required.
28 2. Altered source versions must be plainly marked as such, and must not be
29 misrepresented as being the original software.
30 3. This notice may not be removed or altered from any source distribution.
32 Jean-loup Gailly Mark Adler
33 gzip@prep.ai.mit.edu madler@alumni.caltech.edu
40 /* zutil.h -- internal interface and configuration of the compression library
41 * Copyright (C) 1995 Jean-loup Gailly.
42 * For conditions of distribution and use, see copyright notice in zlib.h
45 /* WARNING: this file should *not* be used by applications. It is
46 part of the implementation of the compression library and is
47 subject to change. Applications should only use zlib.h.
50 /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */
59 /* compile with -Dlocal if your debugger can't find static symbols */
63 typedef unsigned char uch;
65 typedef unsigned short ush;
67 typedef unsigned long ulg;
69 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
71 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
72 /* To be used only when the state is known to be valid */
75 #define NULL ((void *) 0)
78 /* common constants */
83 # define DEF_WBITS MAX_WBITS
85 /* default windowBits for decompression. MAX_WBITS is for compression only */
87 #if MAX_MEM_LEVEL >= 8
88 # define DEF_MEM_LEVEL 8
90 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
92 /* default memLevel */
94 #define STORED_BLOCK 0
95 #define STATIC_TREES 1
97 /* The three kinds of block type */
100 #define MAX_MATCH 258
101 /* The minimum and maximum match lengths */
105 #include <linux/string.h>
106 #define zmemcpy memcpy
107 #define zmemzero(dest, len) memset(dest, 0, len)
109 /* Diagnostic functions */
115 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
116 # define Trace(x) fprintf x
117 # define Tracev(x) {if (verbose) fprintf x ;}
118 # define Tracevv(x) {if (verbose>1) fprintf x ;}
119 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
120 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
122 # define Assert(cond,msg)
127 # define Tracecv(c,x)
131 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
133 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
134 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
136 #define ZALLOC(strm, items, size) \
137 (*((strm)->zalloc))((strm)->opaque, (items), (size))
138 #define ZFREE(strm, addr, size) \
139 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
140 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
142 /* deflate.h -- internal compression state
143 * Copyright (C) 1995 Jean-loup Gailly
144 * For conditions of distribution and use, see copyright notice in zlib.h
147 /* WARNING: this file should *not* be used by applications. It is
148 part of the implementation of the compression library and is
149 subject to change. Applications should only use zlib.h.
153 /* infblock.h -- header to use infblock.c
154 * Copyright (C) 1995 Mark Adler
155 * For conditions of distribution and use, see copyright notice in zlib.h
158 /* WARNING: this file should *not* be used by applications. It is
159 part of the implementation of the compression library and is
160 subject to change. Applications should only use zlib.h.
163 struct inflate_blocks_state;
164 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
166 local inflate_blocks_statef * inflate_blocks_new OF((
168 check_func c, /* check function */
169 uInt w)); /* window size */
171 local int inflate_blocks OF((
172 inflate_blocks_statef *,
174 int)); /* initial return code */
176 local void inflate_blocks_reset OF((
177 inflate_blocks_statef *,
179 uLongf *)); /* check value on output */
181 local int inflate_blocks_free OF((
182 inflate_blocks_statef *,
184 uLongf *)); /* check value on output */
186 local int inflate_addhistory OF((
187 inflate_blocks_statef *,
190 local int inflate_packet_flush OF((
191 inflate_blocks_statef *));
194 /* inftrees.h -- header to use inftrees.c
195 * Copyright (C) 1995 Mark Adler
196 * For conditions of distribution and use, see copyright notice in zlib.h
199 /* WARNING: this file should *not* be used by applications. It is
200 part of the implementation of the compression library and is
201 subject to change. Applications should only use zlib.h.
204 /* Huffman code lookup table entry--this entry is four bytes for machines
205 that have 16-bit pointers (e.g. PC's in the small or medium model). */
207 typedef struct inflate_huft_s FAR inflate_huft;
209 struct inflate_huft_s {
212 Byte Exop; /* number of extra bits or operation */
213 Byte Bits; /* number of bits in this code or subcode */
215 uInt Nalloc; /* number of these allocated here */
216 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
217 } word; /* 16-bit, 8 bytes for 32-bit machines) */
219 uInt Base; /* literal, length base, or distance base */
220 inflate_huft *Next; /* pointer to next level of table */
225 local uInt inflate_hufts;
228 local int inflate_trees_bits OF((
229 uIntf *, /* 19 code lengths */
230 uIntf *, /* bits tree desired/actual depth */
231 inflate_huft * FAR *, /* bits tree result */
232 z_stream *)); /* for zalloc, zfree functions */
234 local int inflate_trees_dynamic OF((
235 uInt, /* number of literal/length codes */
236 uInt, /* number of distance codes */
237 uIntf *, /* that many (total) code lengths */
238 uIntf *, /* literal desired/actual bit depth */
239 uIntf *, /* distance desired/actual bit depth */
240 inflate_huft * FAR *, /* literal/length tree result */
241 inflate_huft * FAR *, /* distance tree result */
242 z_stream *)); /* for zalloc, zfree functions */
244 local int inflate_trees_fixed OF((
245 uIntf *, /* literal desired/actual bit depth */
246 uIntf *, /* distance desired/actual bit depth */
247 inflate_huft * FAR *, /* literal/length tree result */
248 inflate_huft * FAR *)); /* distance tree result */
250 local int inflate_trees_free OF((
251 inflate_huft *, /* tables to free */
252 z_stream *)); /* for zfree function */
256 /* infcodes.h -- header to use infcodes.c
257 * Copyright (C) 1995 Mark Adler
258 * For conditions of distribution and use, see copyright notice in zlib.h
261 /* WARNING: this file should *not* be used by applications. It is
262 part of the implementation of the compression library and is
263 subject to change. Applications should only use zlib.h.
266 struct inflate_codes_state;
267 typedef struct inflate_codes_state FAR inflate_codes_statef;
269 local inflate_codes_statef *inflate_codes_new OF((
271 inflate_huft *, inflate_huft *,
274 local int inflate_codes OF((
275 inflate_blocks_statef *,
279 local void inflate_codes_free OF((
280 inflate_codes_statef *,
285 /* inflate.c -- zlib interface to inflate modules
286 * Copyright (C) 1995 Mark Adler
287 * For conditions of distribution and use, see copyright notice in zlib.h
290 /* inflate private state */
291 struct internal_state {
295 METHOD, /* waiting for method byte */
296 FLAG, /* waiting for flag byte */
297 BLOCKS, /* decompressing blocks */
298 CHECK4, /* four check bytes to go */
299 CHECK3, /* three check bytes to go */
300 CHECK2, /* two check bytes to go */
301 CHECK1, /* one check byte to go */
302 DONE, /* finished check, done */
303 BAD} /* got an error--stay here */
304 mode; /* current inflate mode */
306 /* mode dependent information */
308 uInt method; /* if FLAGS, method byte */
310 uLong was; /* computed check value */
311 uLong need; /* stream check value */
312 } check; /* if CHECK, check values to compare */
313 uInt marker; /* if BAD, inflateSync's marker bytes count */
316 /* mode independent information */
317 int nowrap; /* flag for no wrapper */
318 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
319 inflate_blocks_statef
320 *blocks; /* current inflate_blocks state */
330 if (z == Z_NULL || z->state == Z_NULL)
331 return Z_STREAM_ERROR;
332 z->total_in = z->total_out = 0;
334 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
335 inflate_blocks_reset(z->state->blocks, z, &c);
336 Trace((stderr, "inflate: reset\n"));
346 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
347 return Z_STREAM_ERROR;
348 if (z->state->blocks != Z_NULL)
349 inflate_blocks_free(z->state->blocks, z, &c);
350 ZFREE(z, z->state, sizeof(struct internal_state));
352 Trace((stderr, "inflate: end\n"));
357 int inflateInit2(z, w)
361 /* initialize state */
363 return Z_STREAM_ERROR;
364 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
365 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
366 if ((z->state = (struct internal_state FAR *)
367 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
369 z->state->blocks = Z_NULL;
371 /* handle undocumented nowrap option (no zlib header or check) */
372 z->state->nowrap = 0;
376 z->state->nowrap = 1;
379 /* set window size */
383 return Z_STREAM_ERROR;
385 z->state->wbits = (uInt)w;
387 /* create inflate_blocks state */
388 if ((z->state->blocks =
389 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
395 Trace((stderr, "inflate: allocated\n"));
406 return inflateInit2(z, DEF_WBITS);
410 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
411 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
420 if (z == Z_NULL || z->next_in == Z_NULL)
421 return Z_STREAM_ERROR;
423 while (1) switch (z->state->mode)
427 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
429 z->state->mode = BAD;
430 z->msg = "unknown compression method";
431 z->state->sub.marker = 5; /* can't try inflateSync */
434 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
436 z->state->mode = BAD;
437 z->msg = "invalid window size";
438 z->state->sub.marker = 5; /* can't try inflateSync */
441 z->state->mode = FLAG;
444 if ((b = NEXTBYTE) & 0x20)
446 z->state->mode = BAD;
447 z->msg = "invalid reserved bit";
448 z->state->sub.marker = 5; /* can't try inflateSync */
451 if (((z->state->sub.method << 8) + b) % 31)
453 z->state->mode = BAD;
454 z->msg = "incorrect header check";
455 z->state->sub.marker = 5; /* can't try inflateSync */
458 Trace((stderr, "inflate: zlib header ok\n"));
459 z->state->mode = BLOCKS;
461 r = inflate_blocks(z->state->blocks, z, r);
462 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
463 r = inflate_packet_flush(z->state->blocks);
464 if (r == Z_DATA_ERROR)
466 z->state->mode = BAD;
467 z->state->sub.marker = 0; /* can try inflateSync */
470 if (r != Z_STREAM_END)
473 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
474 if (z->state->nowrap)
476 z->state->mode = DONE;
479 z->state->mode = CHECK4;
482 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
483 z->state->mode = CHECK3;
486 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
487 z->state->mode = CHECK2;
490 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
491 z->state->mode = CHECK1;
494 z->state->sub.check.need += (uLong)NEXTBYTE;
496 if (z->state->sub.check.was != z->state->sub.check.need)
498 z->state->mode = BAD;
499 z->msg = "incorrect data check";
500 z->state->sub.marker = 5; /* can't try inflateSync */
503 Trace((stderr, "inflate: zlib check ok\n"));
504 z->state->mode = DONE;
510 return Z_STREAM_ERROR;
514 if (f != Z_PACKET_FLUSH)
516 z->state->mode = BAD;
517 z->state->sub.marker = 0; /* can try inflateSync */
522 * This subroutine adds the data at next_in/avail_in to the output history
523 * without performing any output. The output buffer must be "caught up";
524 * i.e. no pending output (hence s->read equals s->write), and the state must
525 * be BLOCKS (i.e. we should be willing to see the start of a series of
526 * BLOCKS). On exit, the output will also be caught up, and the checksum
527 * will have been updated if need be.
533 if (z->state->mode != BLOCKS)
535 return inflate_addhistory(z->state->blocks, z);
542 uInt n; /* number of bytes to look at */
543 Bytef *p; /* pointer to bytes */
544 uInt m; /* number of marker bytes found in a row */
545 uLong r, w; /* temporaries to save total_in and total_out */
548 if (z == Z_NULL || z->state == Z_NULL)
549 return Z_STREAM_ERROR;
550 if (z->state->mode != BAD)
552 z->state->mode = BAD;
553 z->state->sub.marker = 0;
555 if ((n = z->avail_in) == 0)
558 m = z->state->sub.marker;
563 if (*p == (Byte)(m < 2 ? 0 : 0xff))
573 z->total_in += p - z->next_in;
576 z->state->sub.marker = m;
578 /* return no joy or set up to restart on a new block */
581 r = z->total_in; w = z->total_out;
583 z->total_in = r; z->total_out = w;
584 z->state->mode = BLOCKS;
592 /* infutil.h -- types and macros common to blocks and codes
593 * Copyright (C) 1995 Mark Adler
594 * For conditions of distribution and use, see copyright notice in zlib.h
597 /* WARNING: this file should *not* be used by applications. It is
598 part of the implementation of the compression library and is
599 subject to change. Applications should only use zlib.h.
602 /* inflate blocks semi-private state */
603 struct inflate_blocks_state {
607 TYPE, /* get type bits (3, including end bit) */
608 LENS, /* get lengths for stored */
609 STORED, /* processing stored block */
610 TABLE, /* get table lengths */
611 BTREE, /* get bit lengths tree for a dynamic block */
612 DTREE, /* get length, distance trees for a dynamic block */
613 CODES, /* processing fixed or dynamic block */
614 DRY, /* output remaining window bytes */
615 DONEB, /* finished last block, done */
616 BADB} /* got a data error--stuck here */
617 mode; /* current inflate_block mode */
619 /* mode dependent information */
621 uInt left; /* if STORED, bytes left to copy */
623 uInt table; /* table lengths (14 bits) */
624 uInt index; /* index into blens (or border) */
625 uIntf *blens; /* bit lengths of codes */
626 uInt bb; /* bit length tree depth */
627 inflate_huft *tb; /* bit length decoding tree */
628 int nblens; /* # elements allocated at blens */
629 } trees; /* if DTREE, decoding info for trees */
631 inflate_huft *tl, *td; /* trees to free */
634 } decode; /* if CODES, current state */
636 uInt last; /* true if this block is the last block */
638 /* mode independent information */
639 uInt bitk; /* bits in bit buffer */
640 uLong bitb; /* bit buffer */
641 Bytef *window; /* sliding window */
642 Bytef *end; /* one byte after sliding window */
643 Bytef *read; /* window read pointer */
644 Bytef *write; /* window write pointer */
645 check_func checkfn; /* check function */
646 uLong check; /* check on output */
651 /* defines for inflate input/output */
652 /* update pointers and return */
653 #define UPDBITS {s->bitb=b;s->bitk=k;}
654 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
655 #define UPDOUT {s->write=q;}
656 #define UPDATE {UPDBITS UPDIN UPDOUT}
657 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
658 /* get bytes and bits */
659 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
660 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
661 #define NEXTBYTE (n--,*p++)
662 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
663 #define DUMPBITS(j) {b>>=(j);k-=(j);}
665 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
666 #define LOADOUT {q=s->write;m=WAVAIL;}
667 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
668 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
669 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
670 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
671 /* load local pointers */
672 #define LOAD {LOADIN LOADOUT}
674 /* And'ing with mask[n] masks the lower n bits */
675 local uInt inflate_mask[] = {
677 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
678 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
681 /* copy as much as possible from the sliding window to the output area */
682 local int inflate_flush OF((
683 inflate_blocks_statef *,
688 /* inffast.h -- header to use inffast.c
689 * Copyright (C) 1995 Mark Adler
690 * For conditions of distribution and use, see copyright notice in zlib.h
693 /* WARNING: this file should *not* be used by applications. It is
694 part of the implementation of the compression library and is
695 subject to change. Applications should only use zlib.h.
698 local int inflate_fast OF((
703 inflate_blocks_statef *,
708 /* infblock.c -- interpret and process block types to last block
709 * Copyright (C) 1995 Mark Adler
710 * For conditions of distribution and use, see copyright notice in zlib.h
713 /* Table for deflate from PKZIP's appnote.txt. */
714 local uInt border[] = { /* Order of the bit length code lengths */
715 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
718 Notes beyond the 1.93a appnote.txt:
720 1. Distance pointers never point before the beginning of the output
722 2. Distance pointers can point back across blocks, up to 32k away.
723 3. There is an implied maximum of 7 bits for the bit length table and
724 15 bits for the actual data.
725 4. If only one code exists, then it is encoded using one bit. (Zero
726 would be more efficient, but perhaps a little confusing.) If two
727 codes exist, they are coded using one bit each (0 and 1).
728 5. There is no way of sending zero distance codes--a dummy must be
729 sent if there are none. (History: a pre 2.0 version of PKZIP would
730 store blocks with no distance codes, but this was discovered to be
731 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
732 zero distance codes, which is sent as one code of zero bits in
734 6. There are up to 286 literal/length codes. Code 256 represents the
735 end-of-block. Note however that the static length tree defines
736 288 codes just to fill out the Huffman codes. Codes 286 and 287
737 cannot be used though, since there is no length base or extra bits
738 defined for them. Similarly, there are up to 30 distance codes.
739 However, static trees define 32 codes (all 5 bits) to fill out the
740 Huffman codes, but the last two had better not show up in the data.
741 7. Unzip can check dynamic Huffman blocks for complete code sets.
742 The exception is that a single code would not be complete (see #4).
743 8. The five bits following the block type is really the number of
744 literal codes sent minus 257.
745 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
746 (1+6+6). Therefore, to output three times the length, you output
747 three codes (1+1+1), whereas to output four times the same length,
748 you only need two codes (1+3). Hmm.
749 10. In the tree reconstruction algorithm, Code = Code + Increment
750 only if BitLength(i) is not zero. (Pretty obvious.)
751 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
752 12. Note: length code 284 can represent 227-258, but length code 285
753 really is 258. The last length deserves its own, short code
754 since it gets used a lot in very redundant files. The length
755 258 is special since 258 - 3 (the min match length) is 255.
756 13. The literal/length and distance code bit lengths are read as a
757 single stream of lengths. It is possible (and advantageous) for
758 a repeat code (16, 17, or 18) to go across the boundary between
759 the two sets of lengths.
763 local void inflate_blocks_reset(s, z, c)
764 inflate_blocks_statef *s;
768 if (s->checkfn != Z_NULL)
770 if (s->mode == BTREE || s->mode == DTREE)
771 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
772 if (s->mode == CODES)
774 inflate_codes_free(s->sub.decode.codes, z);
775 inflate_trees_free(s->sub.decode.td, z);
776 inflate_trees_free(s->sub.decode.tl, z);
781 s->read = s->write = s->window;
782 if (s->checkfn != Z_NULL)
783 s->check = (*s->checkfn)(0L, Z_NULL, 0);
784 Trace((stderr, "inflate: blocks reset\n"));
788 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
793 inflate_blocks_statef *s;
795 if ((s = (inflate_blocks_statef *)ZALLOC
796 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
798 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
800 ZFREE(z, s, sizeof(struct inflate_blocks_state));
803 s->end = s->window + w;
806 Trace((stderr, "inflate: blocks allocated\n"));
807 inflate_blocks_reset(s, z, &s->check);
812 local int inflate_blocks(s, z, r)
813 inflate_blocks_statef *s;
817 uInt t; /* temporary storage */
818 uLong b; /* bit buffer */
819 uInt k; /* bits in bit buffer */
820 Bytef *p; /* input data pointer */
821 uInt n; /* bytes available there */
822 Bytef *q; /* output window write pointer */
823 uInt m; /* bytes to end of window or read pointer */
825 /* copy input/output information to locals (UPDATE macro restores) */
828 /* process input based on current state */
829 while (1) switch (s->mode)
838 Trace((stderr, "inflate: stored block%s\n",
839 s->last ? " (last)" : ""));
841 t = k & 7; /* go to byte boundary */
843 s->mode = LENS; /* get length of stored block */
846 Trace((stderr, "inflate: fixed codes block%s\n",
847 s->last ? " (last)" : ""));
850 inflate_huft *tl, *td;
852 inflate_trees_fixed(&bl, &bd, &tl, &td);
853 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
854 if (s->sub.decode.codes == Z_NULL)
859 s->sub.decode.tl = Z_NULL; /* don't try to free these */
860 s->sub.decode.td = Z_NULL;
865 case 2: /* dynamic */
866 Trace((stderr, "inflate: dynamic codes block%s\n",
867 s->last ? " (last)" : ""));
871 case 3: /* illegal */
874 z->msg = "invalid block type";
881 if (((~b) >> 16) != (b & 0xffff))
884 z->msg = "invalid stored block lengths";
888 s->sub.left = (uInt)b & 0xffff;
889 b = k = 0; /* dump bits */
890 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
891 s->mode = s->sub.left ? STORED : TYPE;
903 if ((s->sub.left -= t) != 0)
905 Tracev((stderr, "inflate: stored end, %lu total out\n",
906 z->total_out + (q >= s->read ? q - s->read :
907 (s->end - s->read) + (q - s->window))));
908 s->mode = s->last ? DRY : TYPE;
912 s->sub.trees.table = t = (uInt)b & 0x3fff;
913 #ifndef PKZIP_BUG_WORKAROUND
914 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
917 z->msg = "too many length or distance symbols";
922 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
925 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
930 s->sub.trees.nblens = t;
932 s->sub.trees.index = 0;
933 Tracev((stderr, "inflate: table sizes ok\n"));
936 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
939 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
942 while (s->sub.trees.index < 19)
943 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
945 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
946 &s->sub.trees.tb, z);
950 if (r == Z_DATA_ERROR)
954 s->sub.trees.index = 0;
955 Tracev((stderr, "inflate: bits tree ok\n"));
958 while (t = s->sub.trees.table,
959 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
966 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
967 t = h->word.what.Bits;
972 s->sub.trees.blens[s->sub.trees.index++] = c;
974 else /* c == 16..18 */
976 i = c == 18 ? 7 : c - 14;
977 j = c == 18 ? 11 : 3;
980 j += (uInt)b & inflate_mask[i];
982 i = s->sub.trees.index;
983 t = s->sub.trees.table;
984 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
988 z->msg = "invalid bit length repeat";
992 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
994 s->sub.trees.blens[i++] = c;
996 s->sub.trees.index = i;
999 inflate_trees_free(s->sub.trees.tb, z);
1000 s->sub.trees.tb = Z_NULL;
1003 inflate_huft *tl, *td;
1004 inflate_codes_statef *c;
1006 bl = 9; /* must be <= 9 for lookahead assumptions */
1007 bd = 6; /* must be <= 9 for lookahead assumptions */
1008 t = s->sub.trees.table;
1009 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
1010 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
1013 if (t == (uInt)Z_DATA_ERROR)
1018 Tracev((stderr, "inflate: trees ok\n"));
1019 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
1021 inflate_trees_free(td, z);
1022 inflate_trees_free(tl, z);
1026 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
1027 s->sub.decode.codes = c;
1028 s->sub.decode.tl = tl;
1029 s->sub.decode.td = td;
1034 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
1035 return inflate_flush(s, z, r);
1037 inflate_codes_free(s->sub.decode.codes, z);
1038 inflate_trees_free(s->sub.decode.td, z);
1039 inflate_trees_free(s->sub.decode.tl, z);
1041 Tracev((stderr, "inflate: codes end, %lu total out\n",
1042 z->total_out + (q >= s->read ? q - s->read :
1043 (s->end - s->read) + (q - s->window))));
1049 if (k > 7) /* return unused byte, if any */
1051 Assert(k < 16, "inflate_codes grabbed too many bytes")
1054 p--; /* can always return one */
1059 if (s->read != s->write)
1075 local int inflate_blocks_free(s, z, c)
1076 inflate_blocks_statef *s;
1080 inflate_blocks_reset(s, z, c);
1081 ZFREE(z, s->window, s->end - s->window);
1082 ZFREE(z, s, sizeof(struct inflate_blocks_state));
1083 Trace((stderr, "inflate: blocks freed\n"));
1088 * This subroutine adds the data at next_in/avail_in to the output history
1089 * without performing any output. The output buffer must be "caught up";
1090 * i.e. no pending output (hence s->read equals s->write), and the state must
1091 * be BLOCKS (i.e. we should be willing to see the start of a series of
1092 * BLOCKS). On exit, the output will also be caught up, and the checksum
1093 * will have been updated if need be.
1095 local int inflate_addhistory(s, z)
1096 inflate_blocks_statef *s;
1099 uLong b; /* bit buffer */ /* NOT USED HERE */
1100 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
1101 uInt t; /* temporary storage */
1102 Bytef *p; /* input data pointer */
1103 uInt n; /* bytes available there */
1104 Bytef *q; /* output window write pointer */
1105 uInt m; /* bytes to end of window or read pointer */
1107 if (s->read != s->write)
1108 return Z_STREAM_ERROR;
1109 if (s->mode != TYPE)
1110 return Z_DATA_ERROR;
1112 /* we're ready to rock */
1114 /* while there is input ready, copy to output buffer, moving
1115 * pointers as needed.
1118 t = n; /* how many to do */
1119 /* is there room until end of buffer? */
1121 /* update check information */
1122 if (s->checkfn != Z_NULL)
1123 s->check = (*s->checkfn)(s->check, q, t);
1129 s->read = q; /* drag read pointer forward */
1130 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
1132 s->read = q = s->window;
1142 * At the end of a Deflate-compressed PPP packet, we expect to have seen
1143 * a `stored' block type value but not the (zero) length bytes.
1145 local int inflate_packet_flush(s)
1146 inflate_blocks_statef *s;
1148 if (s->mode != LENS)
1149 return Z_DATA_ERROR;
1156 /* inftrees.c -- generate Huffman trees for efficient decoding
1157 * Copyright (C) 1995 Mark Adler
1158 * For conditions of distribution and use, see copyright notice in zlib.h
1161 /* simplify the use of the inflate_huft type with some defines */
1162 #define base more.Base
1163 #define next more.Next
1164 #define exop word.what.Exop
1165 #define bits word.what.Bits
1168 local int huft_build OF((
1169 uIntf *, /* code lengths in bits */
1170 uInt, /* number of codes */
1171 uInt, /* number of "simple" codes */
1172 uIntf *, /* list of base values for non-simple codes */
1173 uIntf *, /* list of extra bits for non-simple codes */
1174 inflate_huft * FAR*,/* result: starting table */
1175 uIntf *, /* maximum lookup bits (returns actual) */
1176 z_stream *)); /* for zalloc function */
1178 local voidpf falloc OF((
1179 voidpf, /* opaque pointer (not used) */
1180 uInt, /* number of items */
1181 uInt)); /* size of item */
1183 local void ffree OF((
1184 voidpf q, /* opaque pointer (not used) */
1185 voidpf p, /* what to free (not used) */
1186 uInt n)); /* number of bytes (not used) */
1188 /* Tables for deflate from PKZIP's appnote.txt. */
1189 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
1190 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
1191 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
1192 /* actually lengths - 2; also see note #13 above about 258 */
1193 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
1194 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
1195 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
1196 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
1197 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
1198 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
1199 8193, 12289, 16385, 24577};
1200 local uInt cpdext[] = { /* Extra bits for distance codes */
1201 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
1202 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
1206 Huffman code decoding is performed using a multi-level table lookup.
1207 The fastest way to decode is to simply build a lookup table whose
1208 size is determined by the longest code. However, the time it takes
1209 to build this table can also be a factor if the data being decoded
1210 is not very long. The most common codes are necessarily the
1211 shortest codes, so those codes dominate the decoding time, and hence
1212 the speed. The idea is you can have a shorter table that decodes the
1213 shorter, more probable codes, and then point to subsidiary tables for
1214 the longer codes. The time it costs to decode the longer codes is
1215 then traded against the time it takes to make longer tables.
1217 This results of this trade are in the variables lbits and dbits
1218 below. lbits is the number of bits the first level table for literal/
1219 length codes can decode in one step, and dbits is the same thing for
1220 the distance codes. Subsequent tables are also less than or equal to
1221 those sizes. These values may be adjusted either when all of the
1222 codes are shorter than that, in which case the longest code length in
1223 bits is used, or when the shortest code is *longer* than the requested
1224 table size, in which case the length of the shortest code in bits is
1227 There are two different values for the two tables, since they code a
1228 different number of possibilities each. The literal/length table
1229 codes 286 possible values, or in a flat code, a little over eight
1230 bits. The distance table codes 30 possible values, or a little less
1231 than five bits, flat. The optimum values for speed end up being
1232 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
1233 The optimum values may differ though from machine to machine, and
1234 possibly even between compilers. Your mileage may vary.
1238 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
1239 #define BMAX 15 /* maximum bit length of any code */
1240 #define N_MAX 288 /* maximum number of codes in any set */
1246 local int huft_build(b, n, s, d, e, t, m, zs)
1247 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
1248 uInt n; /* number of codes (assumed <= N_MAX) */
1249 uInt s; /* number of simple-valued codes (0..s-1) */
1250 uIntf *d; /* list of base values for non-simple codes */
1251 uIntf *e; /* list of extra bits for non-simple codes */
1252 inflate_huft * FAR *t; /* result: starting table */
1253 uIntf *m; /* maximum lookup bits, returns actual */
1254 z_stream *zs; /* for zalloc function */
1255 /* Given a list of code lengths and a maximum table size, make a set of
1256 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
1257 if the given code set is incomplete (the tables are still built in this
1258 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
1259 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
1262 uInt a; /* counter for codes of length k */
1263 uInt c[BMAX+1]; /* bit length count table */
1264 uInt f; /* i repeats in table every f entries */
1265 int g; /* maximum code length */
1266 int h; /* table level */
1267 register uInt i; /* counter, current code */
1268 register uInt j; /* counter */
1269 register int k; /* number of bits in current code */
1270 int l; /* bits per table (returned in m) */
1271 register uIntf *p; /* pointer into c[], b[], or v[] */
1272 inflate_huft *q; /* points to current table */
1273 struct inflate_huft_s r; /* table entry for structure assignment */
1274 inflate_huft *u[BMAX]; /* table stack */
1275 uInt v[N_MAX]; /* values in order of bit length */
1276 register int w; /* bits before this table == (l * h) */
1277 uInt x[BMAX+1]; /* bit offsets, then code stack */
1278 uIntf *xp; /* pointer into x */
1279 int y; /* number of dummy codes added */
1280 uInt z; /* number of entries in current table */
1283 /* Generate counts for each bit length */
1285 #define C0 *p++ = 0;
1286 #define C2 C0 C0 C0 C0
1287 #define C4 C2 C2 C2 C2
1288 C4 /* clear c[]--assume BMAX+1 is 16 */
1291 c[*p++]++; /* assume all entries <= BMAX */
1293 if (c[0] == n) /* null input--all zero length codes */
1295 *t = (inflate_huft *)Z_NULL;
1301 /* Find minimum and maximum length, bound *m by those */
1303 for (j = 1; j <= BMAX; j++)
1306 k = j; /* minimum code length */
1309 for (i = BMAX; i; i--)
1312 g = i; /* maximum code length */
1318 /* Adjust last length count to fill out codes, if needed */
1319 for (y = 1 << j; j < i; j++, y <<= 1)
1320 if ((y -= c[j]) < 0)
1321 return Z_DATA_ERROR;
1322 if ((y -= c[i]) < 0)
1323 return Z_DATA_ERROR;
1327 /* Generate starting offsets into the value table for each length */
1329 p = c + 1; xp = x + 2;
1330 while (--i) { /* note that i == g from above */
1331 *xp++ = (j += *p++);
1335 /* Make a table of values in order of bit lengths */
1338 if ((j = *p++) != 0)
1341 n = x[g]; /* set n to length of v */
1344 /* Generate the Huffman codes and for each, make the table entries */
1345 x[0] = i = 0; /* first Huffman code is zero */
1346 p = v; /* grab values in bit order */
1347 h = -1; /* no tables yet--level -1 */
1348 w = -l; /* bits decoded == (l * h) */
1349 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
1350 q = (inflate_huft *)Z_NULL; /* ditto */
1353 /* go through the bit lengths (k already is bits in shortest code) */
1359 /* here i is the Huffman code of length k bits for value *p */
1360 /* make tables up to required level */
1364 w += l; /* previous table always l bits */
1366 /* compute minimum size table less than or equal to l bits */
1367 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
1368 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
1369 { /* too few codes for k-w bit table */
1370 f -= a + 1; /* deduct codes from patterns left */
1373 while (++j < z) /* try smaller tables up to z bits */
1375 if ((f <<= 1) <= *++xp)
1376 break; /* enough codes to use up j bits */
1377 f -= *xp; /* else deduct codes from patterns */
1380 z = 1 << j; /* table entries for j-bit table */
1382 /* allocate and link in new table */
1383 if ((q = (inflate_huft *)ZALLOC
1384 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
1387 inflate_trees_free(u[0], zs);
1388 return Z_MEM_ERROR; /* not enough memory */
1390 q->word.Nalloc = z + 1;
1392 inflate_hufts += z + 1;
1394 *t = q + 1; /* link to list for huft_free() */
1395 *(t = &(q->next)) = Z_NULL;
1396 u[h] = ++q; /* table starts after link */
1398 /* connect to last table, if there is one */
1401 x[h] = i; /* save pattern for backing up */
1402 r.bits = (Byte)l; /* bits to dump before this table */
1403 r.exop = (Byte)j; /* bits in this table */
1404 r.next = q; /* pointer to this table */
1405 j = i >> (w - l); /* (get around Turbo C bug) */
1406 u[h-1][j] = r; /* connect to last table */
1410 /* set up table entry in r */
1411 r.bits = (Byte)(k - w);
1413 r.exop = 128 + 64; /* out of values--invalid code */
1416 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
1417 r.base = *p++; /* simple code is just the value */
1421 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
1422 r.base = d[*p++ - s];
1425 /* fill code-like entries with r */
1427 for (j = i >> w; j < z; j += f)
1430 /* backwards increment the k-bit code i */
1431 for (j = 1 << (k - 1); i & j; j >>= 1)
1435 /* backup over finished tables */
1436 while ((i & ((1 << w) - 1)) != x[h])
1438 h--; /* don't need to update q */
1445 /* Return Z_BUF_ERROR if we were given an incomplete table */
1446 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
1450 local int inflate_trees_bits(c, bb, tb, z)
1451 uIntf *c; /* 19 code lengths */
1452 uIntf *bb; /* bits tree desired/actual depth */
1453 inflate_huft * FAR *tb; /* bits tree result */
1454 z_stream *z; /* for zfree function */
1458 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
1459 if (r == Z_DATA_ERROR)
1460 z->msg = "oversubscribed dynamic bit lengths tree";
1461 else if (r == Z_BUF_ERROR)
1463 inflate_trees_free(*tb, z);
1464 z->msg = "incomplete dynamic bit lengths tree";
1471 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
1472 uInt nl; /* number of literal/length codes */
1473 uInt nd; /* number of distance codes */
1474 uIntf *c; /* that many (total) code lengths */
1475 uIntf *bl; /* literal desired/actual bit depth */
1476 uIntf *bd; /* distance desired/actual bit depth */
1477 inflate_huft * FAR *tl; /* literal/length tree result */
1478 inflate_huft * FAR *td; /* distance tree result */
1479 z_stream *z; /* for zfree function */
1483 /* build literal/length tree */
1484 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
1486 if (r == Z_DATA_ERROR)
1487 z->msg = "oversubscribed literal/length tree";
1488 else if (r == Z_BUF_ERROR)
1490 inflate_trees_free(*tl, z);
1491 z->msg = "incomplete literal/length tree";
1497 /* build distance tree */
1498 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
1500 if (r == Z_DATA_ERROR)
1501 z->msg = "oversubscribed literal/length tree";
1502 else if (r == Z_BUF_ERROR) {
1503 #ifdef PKZIP_BUG_WORKAROUND
1507 inflate_trees_free(*td, z);
1508 z->msg = "incomplete literal/length tree";
1511 inflate_trees_free(*tl, z);
1521 /* build fixed tables only once--keep them here */
1522 local int fixed_lock = 0;
1523 local int fixed_built = 0;
1524 #define FIXEDH 530 /* number of hufts used by fixed tables */
1525 local uInt fixed_left = FIXEDH;
1526 local inflate_huft fixed_mem[FIXEDH];
1527 local uInt fixed_bl;
1528 local uInt fixed_bd;
1529 local inflate_huft *fixed_tl;
1530 local inflate_huft *fixed_td;
1533 local voidpf falloc(q, n, s)
1534 voidpf q; /* opaque pointer (not used) */
1535 uInt n; /* number of items */
1536 uInt s; /* size of item */
1538 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
1539 "inflate_trees falloc overflow");
1540 if (q) s++; /* to make some compilers happy */
1542 return (voidpf)(fixed_mem + fixed_left);
1546 local void ffree(q, p, n)
1551 Assert(0, "inflate_trees ffree called!");
1552 if (q) q = p; /* to make some compilers happy */
1556 local int inflate_trees_fixed(bl, bd, tl, td)
1557 uIntf *bl; /* literal desired/actual bit depth */
1558 uIntf *bd; /* distance desired/actual bit depth */
1559 inflate_huft * FAR *tl; /* literal/length tree result */
1560 inflate_huft * FAR *td; /* distance tree result */
1562 /* build fixed tables if not built already--lock out other instances */
1563 while (++fixed_lock > 1)
1567 int k; /* temporary variable */
1568 unsigned c[288]; /* length list for huft_build */
1569 z_stream z; /* for falloc function */
1571 /* set up fake z_stream for memory routines */
1577 for (k = 0; k < 144; k++)
1579 for (; k < 256; k++)
1581 for (; k < 280; k++)
1583 for (; k < 288; k++)
1586 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
1588 /* distance table */
1589 for (k = 0; k < 30; k++)
1592 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
1606 local int inflate_trees_free(t, z)
1607 inflate_huft *t; /* table to free */
1608 z_stream *z; /* for zfree function */
1609 /* Free the malloc'ed tables built by huft_build(), which makes a linked
1610 list of the tables it made, with the links in a dummy first entry of
1613 register inflate_huft *p, *q;
1615 /* Go through linked list, freeing from the malloced (t[-1]) address. */
1620 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
1627 /* infcodes.c -- process literals and length/distance pairs
1628 * Copyright (C) 1995 Mark Adler
1629 * For conditions of distribution and use, see copyright notice in zlib.h
1632 /* simplify the use of the inflate_huft type with some defines */
1633 #define base more.Base
1634 #define next more.Next
1635 #define exop word.what.Exop
1636 #define bits word.what.Bits
1638 /* inflate codes private state */
1639 struct inflate_codes_state {
1642 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
1643 START, /* x: set up for LEN */
1644 LEN, /* i: get length/literal/eob next */
1645 LENEXT, /* i: getting length extra (have base) */
1646 DIST, /* i: get distance next */
1647 DISTEXT, /* i: getting distance extra */
1648 COPY, /* o: copying bytes in window, waiting for space */
1649 LIT, /* o: got literal, waiting for output space */
1650 WASH, /* o: got eob, possibly still output waiting */
1651 END, /* x: got eob and all data flushed */
1652 BADCODE} /* x: got error */
1653 mode; /* current inflate_codes mode */
1655 /* mode dependent information */
1659 inflate_huft *tree; /* pointer into tree */
1660 uInt need; /* bits needed */
1661 } code; /* if LEN or DIST, where in tree */
1662 uInt lit; /* if LIT, literal */
1664 uInt get; /* bits to get for extra */
1665 uInt dist; /* distance back to copy from */
1666 } copy; /* if EXT or COPY, where and how much */
1667 } sub; /* submode */
1669 /* mode independent information */
1670 Byte lbits; /* ltree bits decoded per branch */
1671 Byte dbits; /* dtree bits decoder per branch */
1672 inflate_huft *ltree; /* literal/length/eob tree */
1673 inflate_huft *dtree; /* distance tree */
1678 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
1680 inflate_huft *tl, *td;
1683 inflate_codes_statef *c;
1685 if ((c = (inflate_codes_statef *)
1686 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
1689 c->lbits = (Byte)bl;
1690 c->dbits = (Byte)bd;
1693 Tracev((stderr, "inflate: codes new\n"));
1699 local int inflate_codes(s, z, r)
1700 inflate_blocks_statef *s;
1704 uInt j; /* temporary storage */
1705 inflate_huft *t; /* temporary pointer */
1706 uInt e; /* extra bits or operation */
1707 uLong b; /* bit buffer */
1708 uInt k; /* bits in bit buffer */
1709 Bytef *p; /* input data pointer */
1710 uInt n; /* bytes available there */
1711 Bytef *q; /* output window write pointer */
1712 uInt m; /* bytes to end of window or read pointer */
1713 Bytef *f; /* pointer to copy strings from */
1714 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
1716 /* copy input/output information to locals (UPDATE macro restores) */
1719 /* process input and output based on current state */
1720 while (1) switch (c->mode)
1721 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
1722 case START: /* x: set up for LEN */
1724 if (m >= 258 && n >= 10)
1727 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
1731 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
1736 c->sub.code.need = c->lbits;
1737 c->sub.code.tree = c->ltree;
1739 case LEN: /* i: get length/literal/eob next */
1740 j = c->sub.code.need;
1742 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
1744 e = (uInt)(t->exop);
1745 if (e == 0) /* literal */
1747 c->sub.lit = t->base;
1748 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
1749 "inflate: literal '%c'\n" :
1750 "inflate: literal 0x%02x\n", t->base));
1754 if (e & 16) /* length */
1756 c->sub.copy.get = e & 15;
1761 if ((e & 64) == 0) /* next table */
1763 c->sub.code.need = e;
1764 c->sub.code.tree = t->next;
1767 if (e & 32) /* end of block */
1769 Tracevv((stderr, "inflate: end of block\n"));
1773 c->mode = BADCODE; /* invalid code */
1774 z->msg = "invalid literal/length code";
1777 case LENEXT: /* i: getting length extra (have base) */
1778 j = c->sub.copy.get;
1780 c->len += (uInt)b & inflate_mask[j];
1782 c->sub.code.need = c->dbits;
1783 c->sub.code.tree = c->dtree;
1784 Tracevv((stderr, "inflate: length %u\n", c->len));
1786 case DIST: /* i: get distance next */
1787 j = c->sub.code.need;
1789 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
1791 e = (uInt)(t->exop);
1792 if (e & 16) /* distance */
1794 c->sub.copy.get = e & 15;
1795 c->sub.copy.dist = t->base;
1799 if ((e & 64) == 0) /* next table */
1801 c->sub.code.need = e;
1802 c->sub.code.tree = t->next;
1805 c->mode = BADCODE; /* invalid code */
1806 z->msg = "invalid distance code";
1809 case DISTEXT: /* i: getting distance extra */
1810 j = c->sub.copy.get;
1812 c->sub.copy.dist += (uInt)b & inflate_mask[j];
1814 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
1816 case COPY: /* o: copying bytes in window, waiting for space */
1817 #ifndef __TURBOC__ /* Turbo C bug for following expression */
1818 f = (uInt)(q - s->window) < c->sub.copy.dist ?
1819 s->end - (c->sub.copy.dist - (q - s->window)) :
1820 q - c->sub.copy.dist;
1822 f = q - c->sub.copy.dist;
1823 if ((uInt)(q - s->window) < c->sub.copy.dist)
1824 f = s->end - (c->sub.copy.dist - (q - s->window));
1836 case LIT: /* o: got literal, waiting for output space */
1841 case WASH: /* o: got eob, possibly more output */
1843 if (s->read != s->write)
1849 case BADCODE: /* x: got error */
1859 local void inflate_codes_free(c, z)
1860 inflate_codes_statef *c;
1863 ZFREE(z, c, sizeof(struct inflate_codes_state));
1864 Tracev((stderr, "inflate: codes free\n"));
1868 /* inflate_util.c -- data and routines common to blocks and codes
1869 * Copyright (C) 1995 Mark Adler
1870 * For conditions of distribution and use, see copyright notice in zlib.h
1873 /* copy as much as possible from the sliding window to the output area */
1874 local int inflate_flush(s, z, r)
1875 inflate_blocks_statef *s;
1882 /* local copies of source and destination pointers */
1886 /* compute number of bytes to copy as far as end of window */
1887 n = (uInt)((q <= s->write ? s->write : s->end) - q);
1888 if (n > z->avail_out) n = z->avail_out;
1889 if (n && r == Z_BUF_ERROR) r = Z_OK;
1891 /* update counters */
1895 /* update check information */
1896 if (s->checkfn != Z_NULL)
1897 s->check = (*s->checkfn)(s->check, q, n);
1899 /* copy as far as end of window */
1904 /* see if more to copy at beginning of window */
1909 if (s->write == s->end)
1910 s->write = s->window;
1912 /* compute bytes to copy */
1913 n = (uInt)(s->write - q);
1914 if (n > z->avail_out) n = z->avail_out;
1915 if (n && r == Z_BUF_ERROR) r = Z_OK;
1917 /* update counters */
1921 /* update check information */
1922 if (s->checkfn != Z_NULL)
1923 s->check = (*s->checkfn)(s->check, q, n);
1931 /* update pointers */
1941 /* inffast.c -- process literals and length/distance pairs fast
1942 * Copyright (C) 1995 Mark Adler
1943 * For conditions of distribution and use, see copyright notice in zlib.h
1946 /* simplify the use of the inflate_huft type with some defines */
1947 #define base more.Base
1948 #define next more.Next
1949 #define exop word.what.Exop
1950 #define bits word.what.Bits
1952 /* macros for bit input with no checking and for returning unused bytes */
1953 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
1954 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
1956 /* Called with number of bytes left to write in window at least 258
1957 (the maximum string length) and number of input bytes available
1958 at least ten. The ten bytes are six bytes for the longest length/
1959 distance pair plus four bytes for overloading the bit buffer. */
1961 local int inflate_fast(bl, bd, tl, td, s, z)
1963 inflate_huft *tl, *td;
1964 inflate_blocks_statef *s;
1967 inflate_huft *t; /* temporary pointer */
1968 uInt e; /* extra bits or operation */
1969 uLong b; /* bit buffer */
1970 uInt k; /* bits in bit buffer */
1971 Bytef *p; /* input data pointer */
1972 uInt n; /* bytes available there */
1973 Bytef *q; /* output window write pointer */
1974 uInt m; /* bytes to end of window or read pointer */
1975 uInt ml; /* mask for literal/length tree */
1976 uInt md; /* mask for distance tree */
1977 uInt c; /* bytes to copy */
1978 uInt d; /* distance back to copy from */
1979 Bytef *r; /* copy source pointer */
1981 /* load input, output, bit values */
1984 /* initialize masks */
1985 ml = inflate_mask[bl];
1986 md = inflate_mask[bd];
1988 /* do until not enough input or output space for fast loop */
1989 do { /* assume called with m >= 258 && n >= 10 */
1990 /* get literal/length code */
1991 GRABBITS(20) /* max bits for literal/length code */
1992 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
1995 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
1996 "inflate: * literal '%c'\n" :
1997 "inflate: * literal 0x%02x\n", t->base));
1998 *q++ = (Byte)t->base;
2006 /* get extra bits for length */
2008 c = t->base + ((uInt)b & inflate_mask[e]);
2010 Tracevv((stderr, "inflate: * length %u\n", c));
2012 /* decode distance base of block to copy */
2013 GRABBITS(15); /* max bits for distance code */
2014 e = (t = td + ((uInt)b & md))->exop;
2019 /* get extra bits to add to distance base */
2021 GRABBITS(e) /* get extra bits (up to 13) */
2022 d = t->base + ((uInt)b & inflate_mask[e]);
2024 Tracevv((stderr, "inflate: * distance %u\n", d));
2028 if ((uInt)(q - s->window) >= d) /* offset before dest */
2031 *q++ = *r++; c--; /* minimum count is three, */
2032 *q++ = *r++; c--; /* so unroll loop a little */
2034 else /* else offset after destination */
2036 e = d - (q - s->window); /* bytes from offset to end */
2037 r = s->end - e; /* pointer to offset */
2038 if (c > e) /* if source crosses, */
2040 c -= e; /* copy to end of window */
2044 r = s->window; /* copy rest from start of window */
2047 do { /* copy all or what's left */
2052 else if ((e & 64) == 0)
2053 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
2056 z->msg = "invalid distance code";
2059 return Z_DATA_ERROR;
2066 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
2069 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
2070 "inflate: * literal '%c'\n" :
2071 "inflate: * literal 0x%02x\n", t->base));
2072 *q++ = (Byte)t->base;
2079 Tracevv((stderr, "inflate: * end of block\n"));
2082 return Z_STREAM_END;
2086 z->msg = "invalid literal/length code";
2089 return Z_DATA_ERROR;
2092 } while (m >= 258 && n >= 10);
2094 /* not enough input or output--restore pointers and return */
2102 /* zutil.c -- target dependent utility functions for the compression library
2103 * Copyright (C) 1995 Jean-loup Gailly.
2104 * For conditions of distribution and use, see copyright notice in zlib.h
2107 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
2109 char *zlib_version = ZLIB_VERSION;
2111 char *z_errmsg[] = {
2112 "stream end", /* Z_STREAM_END 1 */
2114 "file error", /* Z_ERRNO (-1) */
2115 "stream error", /* Z_STREAM_ERROR (-2) */
2116 "data error", /* Z_DATA_ERROR (-3) */
2117 "insufficient memory", /* Z_MEM_ERROR (-4) */
2118 "buffer error", /* Z_BUF_ERROR (-5) */
2123 /* adler32.c -- compute the Adler-32 checksum of a data stream
2124 * Copyright (C) 1995 Mark Adler
2125 * For conditions of distribution and use, see copyright notice in zlib.h
2128 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
2130 #define BASE 65521L /* largest prime smaller than 65536 */
2132 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
2134 #define DO1(buf) {s1 += *buf++; s2 += s1;}
2135 #define DO2(buf) DO1(buf); DO1(buf);
2136 #define DO4(buf) DO2(buf); DO2(buf);
2137 #define DO8(buf) DO4(buf); DO4(buf);
2138 #define DO16(buf) DO8(buf); DO8(buf);
2140 /* ========================================================================= */
2141 uLong adler32(adler, buf, len)
2146 unsigned long s1 = adler & 0xffff;
2147 unsigned long s2 = (adler >> 16) & 0xffff;
2150 if (buf == Z_NULL) return 1L;
2153 k = len < NMAX ? len : NMAX;
2165 return (s2 << 16) | s1;