xref: /netbsd-src/sys/net/zlib.c (revision 466a16a118933bd295a8a104f095714fadf9cf68)
1 /*	$NetBSD: zlib.c,v 1.30 2008/05/05 13:41:30 ad Exp $	*/
2 /*
3  * This file is derived from various .h and .c files from the zlib-1.0.4
4  * distribution by Jean-loup Gailly and Mark Adler, with some additions
5  * by Paul Mackerras to aid in implementing Deflate compression and
6  * decompression for PPP packets.  See zlib.h for conditions of
7  * distribution and use.
8  *
9  * Changes that have been made include:
10  * - added Z_PACKET_FLUSH (see zlib.h for details)
11  * - added inflateIncomp and deflateOutputPending
12  * - allow strm->next_out to be NULL, meaning discard the output
13  *
14  * $Id: zlib.c,v 1.30 2008/05/05 13:41:30 ad Exp $
15  */
16 
17 /*
18  *  ==FILEVERSION 020312==
19  *
20  * This marker is used by the Linux installation script to determine
21  * whether an up-to-date version of this file is already installed.
22  */
23 
24 #include <sys/cdefs.h>
25 __KERNEL_RCSID(0, "$NetBSD: zlib.c,v 1.30 2008/05/05 13:41:30 ad Exp $");
26 
27 #define NO_DUMMY_DECL
28 #define NO_ZCFUNCS
29 #define MY_ZCALLOC
30 
31 #if defined(__FreeBSD__) && (defined(KERNEL) || defined(_KERNEL))
32 #define inflate	inflate_ppp	/* FreeBSD already has an inflate :-( */
33 #endif
34 
35 
36 /* +++ zutil.h */
37 
38 /* zutil.h -- internal interface and configuration of the compression library
39  * Copyright (C) 1995-2002 Jean-loup Gailly.
40  * For conditions of distribution and use, see copyright notice in zlib.h
41  */
42 
43 /* WARNING: this file should *not* be used by applications. It is
44    part of the implementation of the compression library and is
45    subject to change. Applications should only use zlib.h.
46  */
47 
48 /* @(#) $Id: zlib.c,v 1.30 2008/05/05 13:41:30 ad Exp $ */
49 
50 #ifndef _Z_UTIL_H
51 #define _Z_UTIL_H
52 
53 #include "zlib.h"
54 
55 #if defined(KERNEL) || defined(_KERNEL)
56 /* Assume this is a *BSD or SVR4 kernel */
57 #include <sys/param.h>
58 #include <sys/time.h>
59 #include <sys/systm.h>
60 #  define HAVE_MEMCPY
61 #else
62 #if defined(__KERNEL__)
63 /* Assume this is a Linux kernel */
64 #include <linux/string.h>
65 #define HAVE_MEMCPY
66 
67 #else /* not kernel */
68 
69 #if defined(__NetBSD__) && (defined(_KERNEL) || defined(_STANDALONE))
70 
71 /* XXX doesn't seem to need anything at all, but this is for consistency. */
72 #  include <lib/libkern/libkern.h>
73 
74 #else
75 #  include <sys/types.h>
76 #  include <sys/param.h>
77 #ifdef STDC
78 #  include <stddef.h>
79 #  include <string.h>
80 #  include <stdlib.h>
81 #endif
82 #ifdef NO_ERRNO_H
83     extern int errno;
84 #else
85 #   include <errno.h>
86 #endif
87 #endif /* __NetBSD__ && _STANDALONE */
88 #endif /* __KERNEL__ */
89 #endif /* _KERNEL || KERNEL */
90 
91 #ifndef local
92 #  define local static
93 #endif
94 /* compile with -Dlocal if your debugger can't find static symbols */
95 
96 typedef unsigned char  uch;
97 typedef uch FAR uchf;
98 typedef unsigned short ush;
99 typedef ush FAR ushf;
100 typedef unsigned long  ulg;
101 
102 extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
103 /* (size given to avoid silly warnings with Visual C++) */
104 
105 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
106 
107 #define ERR_RETURN(strm,err) \
108   return (strm->msg = ERR_MSG(err), (err))
109 /* To be used only when the state is known to be valid */
110 
111         /* common constants */
112 
113 #ifndef DEF_WBITS
114 #  define DEF_WBITS MAX_WBITS
115 #endif
116 /* default windowBits for decompression. MAX_WBITS is for compression only */
117 
118 #if MAX_MEM_LEVEL >= 8
119 #  define DEF_MEM_LEVEL 8
120 #else
121 #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
122 #endif
123 /* default memLevel */
124 
125 #define STORED_BLOCK 0
126 #define STATIC_TREES 1
127 #define DYN_TREES    2
128 /* The three kinds of block type */
129 
130 #define MIN_MATCH  3
131 #define MAX_MATCH  258
132 /* The minimum and maximum match lengths */
133 
134 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
135 
136         /* target dependencies */
137 
138 #ifdef MSDOS
139 #  define OS_CODE  0x00
140 #  if defined(__TURBOC__) || defined(__BORLANDC__)
141 #    if(__STDC__ == 1) && (defined(__LARGE__) || defined(__COMPACT__))
142        /* Allow compilation with ANSI keywords only enabled */
143        void _Cdecl farfree( void *block );
144        void *_Cdecl farmalloc( unsigned long nbytes );
145 #    else
146 #     include <alloc.h>
147 #    endif
148 #  else /* MSC or DJGPP */
149 #    include <malloc.h>
150 #  endif
151 #endif
152 
153 #ifdef OS2
154 #  define OS_CODE  0x06
155 #endif
156 
157 #ifdef WIN32 /* Window 95 & Windows NT */
158 #  define OS_CODE  0x0b
159 #endif
160 
161 #if defined(VAXC) || defined(VMS)
162 #  define OS_CODE  0x02
163 #  define F_OPEN(name, mode) \
164      fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
165 #endif
166 
167 #ifdef AMIGA
168 #  define OS_CODE  0x01
169 #endif
170 
171 #if defined(ATARI) || defined(atarist)
172 #  define OS_CODE  0x05
173 #endif
174 
175 #if defined(MACOS) || defined(TARGET_OS_MAC)
176 #  define OS_CODE  0x07
177 #  if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
178 #    include <unix.h> /* for fdopen */
179 #  else
180 #    ifndef fdopen
181 #      define fdopen(fd,mode) NULL /* No fdopen() */
182 #    endif
183 #  endif
184 #endif
185 
186 #ifdef __50SERIES /* Prime/PRIMOS */
187 #  define OS_CODE  0x0F
188 #endif
189 
190 #ifdef TOPS20
191 #  define OS_CODE  0x0a
192 #endif
193 
194 #if defined(_BEOS_) || defined(RISCOS)
195 #  define fdopen(fd,mode) NULL /* No fdopen() */
196 #endif
197 
198 #if (defined(_MSC_VER) && (_MSC_VER > 600))
199 #  define fdopen(fd,type)  _fdopen(fd,type)
200 #endif
201 
202 
203         /* Common defaults */
204 
205 #ifndef OS_CODE
206 #  define OS_CODE  0x03  /* assume Unix */
207 #endif
208 
209 #ifndef F_OPEN
210 #  define F_OPEN(name, mode) fopen((name), (mode))
211 #endif
212 
213          /* functions */
214 
215 #ifdef HAVE_STRERROR
216    extern char *strerror __P((int));
217 #  define zstrerror(errnum) strerror(errnum)
218 #else
219 #  define zstrerror(errnum) ""
220 #endif
221 
222 #if defined(pyr)
223 #  define NO_MEMCPY
224 #endif
225 #if defined(SMALL_MEDIUM) && !defined(_MSC_VER) && !defined(__SC__)
226  /* Use our own functions for small and medium model with MSC <= 5.0.
227   * You may have to use the same strategy for Borland C (untested).
228   * The __SC__ check is for Symantec.
229   */
230 #  define NO_MEMCPY
231 #endif
232 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
233 #  define HAVE_MEMCPY
234 #endif
235 #ifdef HAVE_MEMCPY
236 #  ifdef SMALL_MEDIUM /* MSDOS small or medium model */
237 #    define zmemcpy _fmemcpy
238 #    define zmemcmp _fmemcmp
239 #    define zmemzero(dest, len) _fmemset(dest, 0, len)
240 #  else
241 #    define zmemcpy memcpy
242 #    define zmemcmp memcmp
243 #    define zmemzero(dest, len) memset(dest, 0, len)
244 #  endif
245 #else
246    extern void zmemcpy  __P((Bytef* dest, const Bytef* source, uInt len));
247    extern int  zmemcmp  __P((const Bytef* s1, const Bytef* s2, uInt len));
248    extern void zmemzero __P((Bytef* dest, uInt len));
249 #endif
250 
251 /* Diagnostic functions */
252 #if defined(DEBUG_ZLIB) && !defined(_KERNEL) && !defined(_STANDALONE)
253 #  include <stdio.h>
254    extern int z_verbose;
255    extern void z_error    __P((char *m));
256 #  define Assert(cond,msg) {if(!(cond)) z_error(msg);}
257 #  define Trace(x) {if (z_verbose>=0) fprintf x ;}
258 #  define Tracev(x) {if (z_verbose>0) fprintf x ;}
259 #  define Tracevv(x) {if (z_verbose>1) fprintf x ;}
260 #  define Tracec(c,x) {if (z_verbose>0 && (c)) fprintf x ;}
261 #  define Tracecv(c,x) {if (z_verbose>1 && (c)) fprintf x ;}
262 #else
263 #  define Assert(cond,msg)
264 #  define Trace(x)
265 #  define Tracev(x)
266 #  define Tracevv(x)
267 #  define Tracec(c,x)
268 #  define Tracecv(c,x)
269 #endif
270 
271 
272 typedef uLong (ZEXPORT *check_func) __P((uLong check, const Bytef *buf,
273 				       uInt len));
274 voidpf zcalloc __P((voidpf opaque, unsigned items, unsigned size));
275 void   zcfree  __P((voidpf opaque, voidpf ptr));
276 
277 #define ZALLOC(strm, items, size) \
278            (*((strm)->zalloc))((strm)->opaque, (items), (size))
279 #define ZFREE(strm, addr)  (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
280 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
281 
282 #endif /* _Z_UTIL_H */
283 /* --- zutil.h */
284 
285 /* +++ deflate.h */
286 
287 /* deflate.h -- internal compression state
288  * Copyright (C) 1995-2002 Jean-loup Gailly
289  * For conditions of distribution and use, see copyright notice in zlib.h
290  */
291 
292 /* WARNING: this file should *not* be used by applications. It is
293    part of the implementation of the compression library and is
294    subject to change. Applications should only use zlib.h.
295  */
296 
297 /* @(#) $Id: zlib.c,v 1.30 2008/05/05 13:41:30 ad Exp $ */
298 
299 #ifndef _DEFLATE_H
300 #define _DEFLATE_H
301 
302 /* #include "zutil.h" */
303 
304 /* ===========================================================================
305  * Internal compression state.
306  */
307 
308 #define LENGTH_CODES 29
309 /* number of length codes, not counting the special END_BLOCK code */
310 
311 #define LITERALS  256
312 /* number of literal bytes 0..255 */
313 
314 #define L_CODES (LITERALS+1+LENGTH_CODES)
315 /* number of Literal or Length codes, including the END_BLOCK code */
316 
317 #define D_CODES   30
318 /* number of distance codes */
319 
320 #define BL_CODES  19
321 /* number of codes used to transfer the bit lengths */
322 
323 #define HEAP_SIZE (2*L_CODES+1)
324 /* maximum heap size */
325 
326 #define MAX_BITS 15
327 /* All codes must not exceed MAX_BITS bits */
328 
329 #define INIT_STATE    42
330 #define BUSY_STATE   113
331 #define FINISH_STATE 666
332 /* Stream status */
333 
334 
335 /* Data structure describing a single value and its code string. */
336 typedef struct ct_data_s {
337     union {
338         ush  freq;       /* frequency count */
339         ush  code;       /* bit string */
340     } fc;
341     union {
342         ush  dad;        /* father node in Huffman tree */
343         ush  len;        /* length of bit string */
344     } dl;
345 } FAR ct_data;
346 
347 #define Freq fc.freq
348 #define Code fc.code
349 #define Dad  dl.dad
350 #define Len  dl.len
351 
352 typedef struct static_tree_desc_s  static_tree_desc;
353 
354 typedef struct tree_desc_s {
355     ct_data *dyn_tree;           /* the dynamic tree */
356     int     max_code;            /* largest code with non zero frequency */
357     static_tree_desc *stat_desc; /* the corresponding static tree */
358 } FAR tree_desc;
359 
360 typedef ush Pos;
361 typedef Pos FAR Posf;
362 typedef unsigned IPos;
363 
364 /* A Pos is an index in the character window. We use short instead of int to
365  * save space in the various tables. IPos is used only for parameter passing.
366  */
367 
368 typedef struct deflate_state {
369     z_streamp strm;      /* pointer back to this zlib stream */
370     int   status;        /* as the name implies */
371     Bytef *pending_buf;  /* output still pending */
372     ulg   pending_buf_size; /* size of pending_buf */
373     Bytef *pending_out;  /* next pending byte to output to the stream */
374     int   pending;       /* nb of bytes in the pending buffer */
375     int   noheader;      /* suppress zlib header and adler32 */
376     Byte  data_type;     /* UNKNOWN, BINARY or ASCII */
377     Byte  method;        /* STORED (for zip only) or DEFLATED */
378     int   last_flush;    /* value of flush param for previous deflate call */
379 
380                 /* used by deflate.c: */
381 
382     uInt  w_size;        /* LZ77 window size (32K by default) */
383     uInt  w_bits;        /* log2(w_size)  (8..16) */
384     uInt  w_mask;        /* w_size - 1 */
385 
386     Bytef *window;
387     /* Sliding window. Input bytes are read into the second half of the window,
388      * and move to the first half later to keep a dictionary of at least wSize
389      * bytes. With this organization, matches are limited to a distance of
390      * wSize-MAX_MATCH bytes, but this ensures that IO is always
391      * performed with a length multiple of the block size. Also, it limits
392      * the window size to 64K, which is quite useful on MSDOS.
393      * To do: use the user input buffer as sliding window.
394      */
395 
396     ulg window_size;
397     /* Actual size of window: 2*wSize, except when the user input buffer
398      * is directly used as sliding window.
399      */
400 
401     Posf *prev;
402     /* Link to older string with same hash index. To limit the size of this
403      * array to 64K, this link is maintained only for the last 32K strings.
404      * An index in this array is thus a window index modulo 32K.
405      */
406 
407     Posf *head; /* Heads of the hash chains or NIL. */
408 
409     uInt  ins_h;          /* hash index of string to be inserted */
410     uInt  hash_size;      /* number of elements in hash table */
411     uInt  hash_bits;      /* log2(hash_size) */
412     uInt  hash_mask;      /* hash_size-1 */
413 
414     uInt  hash_shift;
415     /* Number of bits by which ins_h must be shifted at each input
416      * step. It must be such that after MIN_MATCH steps, the oldest
417      * byte no longer takes part in the hash key, that is:
418      *   hash_shift * MIN_MATCH >= hash_bits
419      */
420 
421     long block_start;
422     /* Window position at the beginning of the current output block. Gets
423      * negative when the window is moved backwards.
424      */
425 
426     uInt match_length;           /* length of best match */
427     IPos prev_match;             /* previous match */
428     int match_available;         /* set if previous match exists */
429     uInt strstart;               /* start of string to insert */
430     uInt match_start;            /* start of matching string */
431     uInt lookahead;              /* number of valid bytes ahead in window */
432 
433     uInt prev_length;
434     /* Length of the best match at previous step. Matches not greater than this
435      * are discarded. This is used in the lazy match evaluation.
436      */
437 
438     uInt max_chain_length;
439     /* To speed up deflation, hash chains are never searched beyond this
440      * length.  A higher limit improves compression ratio but degrades the
441      * speed.
442      */
443 
444     uInt max_lazy_match;
445     /* Attempt to find a better match only when the current match is strictly
446      * smaller than this value. This mechanism is used only for compression
447      * levels >= 4.
448      */
449 #   define max_insert_length  max_lazy_match
450     /* Insert new strings in the hash table only if the match length is not
451      * greater than this length. This saves time but degrades compression.
452      * max_insert_length is used only for compression levels <= 3.
453      */
454 
455     int level;    /* compression level (1..9) */
456     int strategy; /* favor or force Huffman coding*/
457 
458     uInt good_match;
459     /* Use a faster search when the previous match is longer than this */
460 
461     int nice_match; /* Stop searching when current match exceeds this */
462 
463                 /* used by trees.c: */
464     /* Didn't use ct_data typedef below to supress compiler warning */
465     struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
466     struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
467     struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
468 
469     struct tree_desc_s l_desc;               /* desc. for literal tree */
470     struct tree_desc_s d_desc;               /* desc. for distance tree */
471     struct tree_desc_s bl_desc;              /* desc. for bit length tree */
472 
473     ush bl_count[MAX_BITS+1];
474     /* number of codes at each bit length for an optimal tree */
475 
476     int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
477     int heap_len;               /* number of elements in the heap */
478     int heap_max;               /* element of largest frequency */
479     /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
480      * The same heap array is used to build all trees.
481      */
482 
483     uch depth[2*L_CODES+1];
484     /* Depth of each subtree used as tie breaker for trees of equal frequency
485      */
486 
487     uchf *l_buf;          /* buffer for literals or lengths */
488 
489     uInt  lit_bufsize;
490     /* Size of match buffer for literals/lengths.  There are 4 reasons for
491      * limiting lit_bufsize to 64K:
492      *   - frequencies can be kept in 16 bit counters
493      *   - if compression is not successful for the first block, all input
494      *     data is still in the window so we can still emit a stored block even
495      *     when input comes from standard input.  (This can also be done for
496      *     all blocks if lit_bufsize is not greater than 32K.)
497      *   - if compression is not successful for a file smaller than 64K, we can
498      *     even emit a stored file instead of a stored block (saving 5 bytes).
499      *     This is applicable only for zip (not gzip or zlib).
500      *   - creating new Huffman trees less frequently may not provide fast
501      *     adaptation to changes in the input data statistics. (Take for
502      *     example a binary file with poorly compressible code followed by
503      *     a highly compressible string table.) Smaller buffer sizes give
504      *     fast adaptation but have of course the overhead of transmitting
505      *     trees more frequently.
506      *   - I can't count above 4
507      */
508 
509     uInt last_lit;      /* running index in l_buf */
510 
511     ushf *d_buf;
512     /* Buffer for distances. To simplify the code, d_buf and l_buf have
513      * the same number of elements. To use different lengths, an extra flag
514      * array would be necessary.
515      */
516 
517     ulg opt_len;        /* bit length of current block with optimal trees */
518     ulg static_len;     /* bit length of current block with static trees */
519     uInt matches;       /* number of string matches in current block */
520     int last_eob_len;   /* bit length of EOB code for last block */
521 
522 #ifdef DEBUG_ZLIB
523     ulg compressed_len; /* total bit length of compressed file mod 2^32 */
524     ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
525 #endif
526 
527     ush bi_buf;
528     /* Output buffer. bits are inserted starting at the bottom (least
529      * significant bits).
530      */
531     int bi_valid;
532     /* Number of valid bits in bi_buf.  All bits above the last valid bit
533      * are always zero.
534      */
535 
536 } FAR deflate_state;
537 
538 /* Output a byte on the stream.
539  * IN assertion: there is enough room in pending_buf.
540  */
541 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
542 
543 
544 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
545 /* Minimum amount of lookahead, except at the end of the input file.
546  * See deflate.c for comments about the MIN_MATCH+1.
547  */
548 
549 #define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
550 /* In order to simplify the code, particularly on 16 bit machines, match
551  * distances are limited to MAX_DIST instead of WSIZE.
552  */
553 
554         /* in trees.c */
555 void _tr_init         __P((deflate_state *s));
556 int  _tr_tally        __P((deflate_state *s, unsigned dist, unsigned lc));
557 void _tr_flush_block  __P((deflate_state *s, charf *buf, ulg stored_len,
558 			  int eof));
559 void _tr_align        __P((deflate_state *s));
560 void _tr_stored_block __P((deflate_state *s, charf *buf, ulg stored_len,
561                           int eof));
562 void _tr_stored_type_only __P((deflate_state *));
563 
564 #define d_code(dist) \
565    ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
566 /* Mapping from a distance to a distance code. dist is the distance - 1 and
567  * must not have side effects. _dist_code[256] and _dist_code[257] are never
568  * used.
569  */
570 
571 #ifndef DEBUG_ZLIB
572 /* Inline versions of _tr_tally for speed: */
573 
574 #if defined(GEN_TREES_H) || !defined(STDC)
575   extern uch _length_code[];
576   extern uch _dist_code[];
577 #else
578   extern const uch _length_code[];
579   extern const uch _dist_code[];
580 #endif
581 
582 # define _tr_tally_lit(s, c, flush) \
583   { uch cc = (c); \
584     s->d_buf[s->last_lit] = 0; \
585     s->l_buf[s->last_lit++] = cc; \
586     s->dyn_ltree[cc].Freq++; \
587     flush = (s->last_lit == s->lit_bufsize-1); \
588    }
589 # define _tr_tally_dist(s, distance, length, flush) \
590   { uch len = (length); \
591     ush dist = (distance); \
592     s->d_buf[s->last_lit] = dist; \
593     s->l_buf[s->last_lit++] = len; \
594     dist--; \
595     s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
596     s->dyn_dtree[d_code(dist)].Freq++; \
597     flush = (s->last_lit == s->lit_bufsize-1); \
598   }
599 #else
600 # define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
601 # define _tr_tally_dist(s, distance, length, flush) \
602               flush = _tr_tally(s, distance, length)
603 #endif
604 
605 #endif
606 /* --- deflate.h */
607 
608 /* +++ deflate.c */
609 
610 /* deflate.c -- compress data using the deflation algorithm
611  * Copyright (C) 1995-2002 Jean-loup Gailly.
612  * For conditions of distribution and use, see copyright notice in zlib.h
613  */
614 
615 /*
616  *  ALGORITHM
617  *
618  *      The "deflation" process depends on being able to identify portions
619  *      of the input text which are identical to earlier input (within a
620  *      sliding window trailing behind the input currently being processed).
621  *
622  *      The most straightforward technique turns out to be the fastest for
623  *      most input files: try all possible matches and select the longest.
624  *      The key feature of this algorithm is that insertions into the string
625  *      dictionary are very simple and thus fast, and deletions are avoided
626  *      completely. Insertions are performed at each input character, whereas
627  *      string matches are performed only when the previous match ends. So it
628  *      is preferable to spend more time in matches to allow very fast string
629  *      insertions and avoid deletions. The matching algorithm for small
630  *      strings is inspired from that of Rabin & Karp. A brute force approach
631  *      is used to find longer strings when a small match has been found.
632  *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
633  *      (by Leonid Broukhis).
634  *         A previous version of this file used a more sophisticated algorithm
635  *      (by Fiala and Greene) which is guaranteed to run in linear amortized
636  *      time, but has a larger average cost, uses more memory and is patented.
637  *      However the F&G algorithm may be faster for some highly redundant
638  *      files if the parameter max_chain_length (described below) is too large.
639  *
640  *  ACKNOWLEDGEMENTS
641  *
642  *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
643  *      I found it in 'freeze' written by Leonid Broukhis.
644  *      Thanks to many people for bug reports and testing.
645  *
646  *  REFERENCES
647  *
648  *      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
649  *      Available in ftp://ds.internic.net/rfc/rfc1951.txt
650  *
651  *      A description of the Rabin and Karp algorithm is given in the book
652  *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
653  *
654  *      Fiala,E.R., and Greene,D.H.
655  *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
656  *
657  */
658 
659 /* @(#) $Id: zlib.c,v 1.30 2008/05/05 13:41:30 ad Exp $ */
660 
661 /* #include "deflate.h" */
662 
663 const char deflate_copyright[] =
664    " deflate 1.1.4 Copyright 1995-2002 Jean-loup Gailly ";
665 /*
666   If you use the zlib library in a product, an acknowledgment is welcome
667   in the documentation of your product. If for some reason you cannot
668   include such an acknowledgment, I would appreciate that you keep this
669   copyright string in the executable of your product.
670  */
671 
672 /* ===========================================================================
673  *  Function prototypes.
674  */
675 typedef enum {
676     need_more,      /* block not completed, need more input or more output */
677     block_done,     /* block flush performed */
678     finish_started, /* finish started, need only more output at next deflate */
679     finish_done     /* finish done, accept no more input or output */
680 } block_state;
681 
682 typedef block_state (*compress_func) __P((deflate_state *s, int flush));
683 /* Compression function. Returns the block state after the call. */
684 
685 local void fill_window    __P((deflate_state *s));
686 local block_state deflate_stored __P((deflate_state *s, int flush));
687 local block_state deflate_fast   __P((deflate_state *s, int flush));
688 local block_state deflate_slow   __P((deflate_state *s, int flush));
689 local void lm_init        __P((deflate_state *s));
690 local void putShortMSB    __P((deflate_state *s, uInt b));
691 local void flush_pending  __P((z_streamp strm));
692 local int read_buf        __P((z_streamp strm, Bytef *buf, unsigned size));
693 #ifdef ASMV
694       void match_init __P((void)); /* asm code initialization */
695       uInt longest_match  __P((deflate_state *s, IPos cur_match));
696 #else
697 local uInt longest_match  __P((deflate_state *s, IPos cur_match));
698 #endif
699 
700 #ifdef DEBUG_ZLIB
701 local  void check_match __P((deflate_state *s, IPos start, IPos match,
702                             int length));
703 #endif
704 
705 /* ===========================================================================
706  * Local data
707  */
708 
709 #define NIL 0
710 /* Tail of hash chains */
711 
712 #ifndef TOO_FAR
713 #  define TOO_FAR 4096
714 #endif
715 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
716 
717 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
718 /* Minimum amount of lookahead, except at the end of the input file.
719  * See deflate.c for comments about the MIN_MATCH+1.
720  */
721 
722 /* Values for max_lazy_match, good_match and max_chain_length, depending on
723  * the desired pack level (0..9). The values given below have been tuned to
724  * exclude worst case performance for pathological files. Better values may be
725  * found for specific files.
726  */
727 typedef struct config_s {
728    ush good_length; /* reduce lazy search above this match length */
729    ush max_lazy;    /* do not perform lazy search above this match length */
730    ush nice_length; /* quit search above this match length */
731    ush max_chain;
732    compress_func func;
733 } config;
734 
735 local const config configuration_table[10] = {
736 /*      good lazy nice chain */
737 /* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
738 /* 1 */ {4,    4,  8,    4, deflate_fast}, /* maximum speed, no lazy matches */
739 /* 2 */ {4,    5, 16,    8, deflate_fast},
740 /* 3 */ {4,    6, 32,   32, deflate_fast},
741 
742 /* 4 */ {4,    4, 16,   16, deflate_slow},  /* lazy matches */
743 /* 5 */ {8,   16, 32,   32, deflate_slow},
744 /* 6 */ {8,   16, 128, 128, deflate_slow},
745 /* 7 */ {8,   32, 128, 256, deflate_slow},
746 /* 8 */ {32, 128, 258, 1024, deflate_slow},
747 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
748 
749 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
750  * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
751  * meaning.
752  */
753 
754 #define EQUAL 0
755 /* result of memcmp for equal strings */
756 
757 #ifndef NO_DUMMY_DECL
758 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
759 #endif
760 
761 /* ===========================================================================
762  * Update a hash value with the given input byte
763  * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
764  *    input characters, so that a running hash key can be computed from the
765  *    previous key instead of complete recalculation each time.
766  */
767 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
768 
769 
770 /* ===========================================================================
771  * Insert string str in the dictionary and set match_head to the previous head
772  * of the hash chain (the most recent string with same hash key). Return
773  * the previous length of the hash chain.
774  * If this file is compiled with -DFASTEST, the compression level is forced
775  * to 1, and no hash chains are maintained.
776  * IN  assertion: all calls to to INSERT_STRING are made with consecutive
777  *    input characters and the first MIN_MATCH bytes of str are valid
778  *    (except for the last MIN_MATCH-1 bytes of the input file).
779  */
780 #ifdef FASTEST
781 #define INSERT_STRING(s, str, match_head) \
782    (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
783     match_head = s->head[s->ins_h], \
784     s->head[s->ins_h] = (Pos)(str))
785 #else
786 #define INSERT_STRING(s, str, match_head) \
787    (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
788     s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
789     s->head[s->ins_h] = (Pos)(str))
790 #endif
791 
792 /* ===========================================================================
793  * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
794  * prev[] will be initialized on the fly.
795  */
796 #define CLEAR_HASH(s) \
797     s->head[s->hash_size-1] = NIL; \
798     zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
799 
800 /* ========================================================================= */
801 #if 0
802 int ZEXPORT deflateInit_(strm, level, version, stream_size)
803     z_streamp strm;
804     int level;
805     const char *version;
806     int stream_size;
807 {
808     return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
809 			 Z_DEFAULT_STRATEGY, version, stream_size);
810     /* To do: ignore strm->next_in if we use it as window */
811 }
812 #endif
813 
814 /* ========================================================================= */
815 int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
816 		  vers, stream_size)
817     z_streamp strm;
818     int  level;
819     int  method;
820     int  windowBits;
821     int  memLevel;
822     int  strategy;
823     const char *vers;
824     int stream_size;
825 {
826     deflate_state *s;
827     int noheader = 0;
828     static const char* my_version = ZLIB_VERSION;
829 
830     ushf *overlay;
831     /* We overlay pending_buf and d_buf+l_buf. This works since the average
832      * output size for (length,distance) codes is <= 24 bits.
833      */
834 
835     if (vers == Z_NULL || vers[0] != my_version[0] ||
836         stream_size != sizeof(z_stream)) {
837 	return Z_VERSION_ERROR;
838     }
839     if (strm == Z_NULL) return Z_STREAM_ERROR;
840 
841     strm->msg = Z_NULL;
842 #ifndef NO_ZCFUNCS
843     if (strm->zalloc == Z_NULL) {
844 	strm->zalloc = zcalloc;
845 	strm->opaque = (voidpf)0;
846     }
847     if (strm->zfree == Z_NULL) strm->zfree = zcfree;
848 #endif
849 
850     if (level == Z_DEFAULT_COMPRESSION) level = 6;
851 #ifdef FASTEST
852     level = 1;
853 #endif
854 
855     if (windowBits < 0) { /* undocumented feature: suppress zlib header */
856         noheader = 1;
857         windowBits = -windowBits;
858     }
859     if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
860         windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
861 	strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
862         return Z_STREAM_ERROR;
863     }
864     s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
865     if (s == Z_NULL) return Z_MEM_ERROR;
866     strm->state = (struct internal_state FAR *)s;
867     s->strm = strm;
868 
869     s->noheader = noheader;
870     s->w_bits = windowBits;
871     s->w_size = 1 << s->w_bits;
872     s->w_mask = s->w_size - 1;
873 
874     s->hash_bits = memLevel + 7;
875     s->hash_size = 1 << s->hash_bits;
876     s->hash_mask = s->hash_size - 1;
877     s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
878 
879     s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
880     s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
881     s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
882 
883     s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
884 
885     overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
886     s->pending_buf = (uchf *) overlay;
887     s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
888 
889     if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
890         s->pending_buf == Z_NULL) {
891         strm->msg = ERR_MSG(Z_MEM_ERROR);
892 	s->status = INIT_STATE;
893         deflateEnd (strm);
894         return Z_MEM_ERROR;
895     }
896     s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
897     s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
898 
899     s->level = level;
900     s->strategy = strategy;
901     s->method = (Byte)method;
902 
903     return deflateReset(strm);
904 }
905 
906 /* ========================================================================= */
907 #if 0
908 int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
909     z_streamp strm;
910     const Bytef *dictionary;
911     uInt  dictLength;
912 {
913     deflate_state *s;
914     uInt length = dictLength;
915     uInt n;
916     IPos hash_head = 0;
917 
918     if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
919         return Z_STREAM_ERROR;
920 
921     s = (deflate_state *)strm->state;
922     if (s->status != INIT_STATE) return Z_STREAM_ERROR;
923 
924     strm->adler = adler32(strm->adler, dictionary, dictLength);
925 
926     if (length < MIN_MATCH) return Z_OK;
927     if (length > MAX_DIST(s)) {
928 	length = MAX_DIST(s);
929 #ifndef USE_DICT_HEAD
930 	dictionary += dictLength - length; /* use the tail of the dictionary */
931 #endif
932     }
933     zmemcpy(s->window, dictionary, length);
934     s->strstart = length;
935     s->block_start = (long)length;
936 
937     /* Insert all strings in the hash table (except for the last two bytes).
938      * s->lookahead stays null, so s->ins_h will be recomputed at the next
939      * call of fill_window.
940      */
941     s->ins_h = s->window[0];
942     UPDATE_HASH(s, s->ins_h, s->window[1]);
943     for (n = 0; n <= length - MIN_MATCH; n++) {
944 	INSERT_STRING(s, n, hash_head);
945     }
946     if (hash_head) hash_head = 0;  /* to make compiler happy */
947     return Z_OK;
948 }
949 #endif
950 
951 /* ========================================================================= */
952 int ZEXPORT deflateReset (strm)
953     z_streamp strm;
954 {
955     deflate_state *s;
956 
957     if (strm == Z_NULL || strm->state == Z_NULL ||
958         strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
959 
960     strm->total_in = strm->total_out = 0;
961     strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
962     strm->data_type = Z_UNKNOWN;
963 
964     s = (deflate_state *)strm->state;
965     s->pending = 0;
966     s->pending_out = s->pending_buf;
967 
968     if (s->noheader < 0) {
969         s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
970     }
971     s->status = s->noheader ? BUSY_STATE : INIT_STATE;
972     strm->adler = 1;
973     s->last_flush = Z_NO_FLUSH;
974 
975     _tr_init(s);
976     lm_init(s);
977 
978     return Z_OK;
979 }
980 
981 /* ========================================================================= */
982 #if 0
983 int ZEXPORT deflateParams(strm, level, strategy)
984     z_streamp strm;
985     int level;
986     int strategy;
987 {
988     deflate_state *s;
989     compress_func func;
990     int err = Z_OK;
991 
992     if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
993     s = (deflate_state *)strm->state;
994 
995     if (level == Z_DEFAULT_COMPRESSION) {
996 	level = 6;
997     }
998     if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
999 	return Z_STREAM_ERROR;
1000     }
1001     func = configuration_table[s->level].func;
1002 
1003     if (func != configuration_table[level].func && strm->total_in != 0) {
1004 	/* Flush the last buffer: */
1005 	err = deflate(strm, Z_PARTIAL_FLUSH);
1006     }
1007     if (s->level != level) {
1008 	s->level = level;
1009 	s->max_lazy_match   = configuration_table[level].max_lazy;
1010 	s->good_match       = configuration_table[level].good_length;
1011 	s->nice_match       = configuration_table[level].nice_length;
1012 	s->max_chain_length = configuration_table[level].max_chain;
1013     }
1014     s->strategy = strategy;
1015     return err;
1016 }
1017 #endif
1018 
1019 /* =========================================================================
1020  * Put a short in the pending buffer. The 16-bit value is put in MSB order.
1021  * IN assertion: the stream state is correct and there is enough room in
1022  * pending_buf.
1023  */
1024 local void putShortMSB (s, b)
1025     deflate_state *s;
1026     uInt b;
1027 {
1028     put_byte(s, (Byte)(b >> 8));
1029     put_byte(s, (Byte)(b & 0xff));
1030 }
1031 
1032 /* =========================================================================
1033  * Flush as much pending output as possible. All deflate() output goes
1034  * through this function so some applications may wish to modify it
1035  * to avoid allocating a large strm->next_out buffer and copying into it.
1036  * (See also read_buf()).
1037  */
1038 local void flush_pending(strm)
1039     z_streamp strm;
1040 {
1041     deflate_state *s = (deflate_state *) strm->state;
1042     unsigned len = s->pending;
1043 
1044     if (len > strm->avail_out) len = strm->avail_out;
1045     if (len == 0) return;
1046 
1047     if (strm->next_out != Z_NULL) {
1048       zmemcpy(strm->next_out, s->pending_out, len);
1049       strm->next_out  += len;
1050     }
1051     s->pending_out  += len;
1052     strm->total_out += len;
1053     strm->avail_out  -= len;
1054     s->pending -= len;
1055     if (s->pending == 0) {
1056         s->pending_out = s->pending_buf;
1057     }
1058 }
1059 
1060 /* ========================================================================= */
1061 int ZEXPORT deflate (strm, flush)
1062     z_streamp strm;
1063     int flush;
1064 {
1065     int old_flush; /* value of flush param for previous deflate call */
1066     deflate_state *s;
1067 
1068     if (strm == Z_NULL || strm->state == Z_NULL ||
1069 	flush > Z_FINISH || flush < 0) {
1070         return Z_STREAM_ERROR;
1071     }
1072     s = (deflate_state *)strm->state;
1073 
1074     if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
1075 	(s->status == FINISH_STATE && flush != Z_FINISH)) {
1076         ERR_RETURN(strm, Z_STREAM_ERROR);
1077     }
1078     if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
1079 
1080     s->strm = strm; /* just in case */
1081     old_flush = s->last_flush;
1082     s->last_flush = flush;
1083 
1084     /* Write the zlib header */
1085     if (s->status == INIT_STATE) {
1086 
1087         uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1088         uInt level_flags = (s->level-1) >> 1;
1089 
1090         if (level_flags > 3) level_flags = 3;
1091         header |= (level_flags << 6);
1092 	if (s->strstart != 0) header |= PRESET_DICT;
1093         header += 31 - (header % 31);
1094 
1095         s->status = BUSY_STATE;
1096         putShortMSB(s, header);
1097 
1098 	/* Save the adler32 of the preset dictionary: */
1099 	if (s->strstart != 0) {
1100 	    putShortMSB(s, (uInt)(strm->adler >> 16));
1101 	    putShortMSB(s, (uInt)(strm->adler & 0xffff));
1102 	}
1103 	strm->adler = 1L;
1104     }
1105 
1106     /* Flush as much pending output as possible */
1107     if (s->pending != 0) {
1108         flush_pending(strm);
1109         if (strm->avail_out == 0) {
1110 	    /* Since avail_out is 0, deflate will be called again with
1111 	     * more output space, but possibly with both pending and
1112 	     * avail_in equal to zero. There won't be anything to do,
1113 	     * but this is not an error situation so make sure we
1114 	     * return OK instead of BUF_ERROR at next call of deflate:
1115              */
1116 	    s->last_flush = -1;
1117 	    return Z_OK;
1118 	}
1119 
1120     /* Make sure there is something to do and avoid duplicate consecutive
1121      * flushes. For repeated and useless calls with Z_FINISH, we keep
1122      * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1123      */
1124     } else if (strm->avail_in == 0 && flush <= old_flush &&
1125 	       flush != Z_FINISH) {
1126         ERR_RETURN(strm, Z_BUF_ERROR);
1127     }
1128 
1129     /* User must not provide more input after the first FINISH: */
1130     if (s->status == FINISH_STATE && strm->avail_in != 0) {
1131         ERR_RETURN(strm, Z_BUF_ERROR);
1132     }
1133 
1134     /* Start a new block or continue the current one.
1135      */
1136     if (strm->avail_in != 0 || s->lookahead != 0 ||
1137         (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1138         block_state bstate;
1139 
1140 	bstate = (*(configuration_table[s->level].func))(s, flush);
1141 
1142         if (bstate == finish_started || bstate == finish_done) {
1143             s->status = FINISH_STATE;
1144         }
1145         if (bstate == need_more || bstate == finish_started) {
1146 	    if (strm->avail_out == 0) {
1147 	        s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1148 	    }
1149 	    return Z_OK;
1150 	    /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1151 	     * of deflate should use the same flush parameter to make sure
1152 	     * that the flush is complete. So we don't have to output an
1153 	     * empty block here, this will be done at next call. This also
1154 	     * ensures that for a very small output buffer, we emit at most
1155 	     * one empty block.
1156 	     */
1157 	}
1158         if (bstate == block_done) {
1159             if (flush == Z_PARTIAL_FLUSH) {
1160                 _tr_align(s);
1161 	    } else if (flush == Z_PACKET_FLUSH) {
1162 		/* Output just the 3-bit `stored' block type value,
1163 		   but not a zero length. */
1164 		_tr_stored_type_only(s);
1165             } else { /* FULL_FLUSH or SYNC_FLUSH */
1166                 _tr_stored_block(s, (char*)0, 0L, 0);
1167                 /* For a full flush, this empty block will be recognized
1168                  * as a special marker by inflate_sync().
1169                  */
1170                 if (flush == Z_FULL_FLUSH) {
1171                     CLEAR_HASH(s);             /* forget history */
1172                 }
1173             }
1174             flush_pending(strm);
1175 	    if (strm->avail_out == 0) {
1176 	      s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1177 	      return Z_OK;
1178 	    }
1179         }
1180     }
1181     Assert(strm->avail_out > 0, "bug2");
1182 
1183     if (flush != Z_FINISH) return Z_OK;
1184     if (s->noheader) return Z_STREAM_END;
1185 
1186     /* Write the zlib trailer (adler32) */
1187     putShortMSB(s, (uInt)(strm->adler >> 16));
1188     putShortMSB(s, (uInt)(strm->adler & 0xffff));
1189     flush_pending(strm);
1190     /* If avail_out is zero, the application will call deflate again
1191      * to flush the rest.
1192      */
1193     s->noheader = -1; /* write the trailer only once! */
1194     return s->pending != 0 ? Z_OK : Z_STREAM_END;
1195 }
1196 
1197 /* ========================================================================= */
1198 int ZEXPORT deflateEnd (strm)
1199     z_streamp strm;
1200 {
1201     int status;
1202     deflate_state *s;
1203 
1204     if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1205     s = (deflate_state *) strm->state;
1206 
1207     status = s->status;
1208     if (status != INIT_STATE && status != BUSY_STATE &&
1209 	status != FINISH_STATE) {
1210       return Z_STREAM_ERROR;
1211     }
1212 
1213     /* Deallocate in reverse order of allocations: */
1214     TRY_FREE(strm, s->pending_buf);
1215     TRY_FREE(strm, s->head);
1216     TRY_FREE(strm, s->prev);
1217     TRY_FREE(strm, s->window);
1218 
1219     ZFREE(strm, s);
1220     strm->state = Z_NULL;
1221 
1222     return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1223 }
1224 
1225 /* =========================================================================
1226  * Copy the source state to the destination state.
1227  * To simplify the source, this is not supported for 16-bit MSDOS (which
1228  * doesn't have enough memory anyway to duplicate compression states).
1229  */
1230 #if 0
1231 int ZEXPORT deflateCopy (dest, source)
1232     z_streamp dest;
1233     z_streamp source;
1234 {
1235 #ifdef MAXSEG_64K
1236     return Z_STREAM_ERROR;
1237 #else
1238     deflate_state *ds;
1239     deflate_state *ss;
1240     ushf *overlay;
1241 
1242 
1243     if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
1244         return Z_STREAM_ERROR;
1245     }
1246 
1247     ss = (deflate_state *)source->state;
1248 
1249     *dest = *source;
1250 
1251     ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1252     if (ds == Z_NULL) return Z_MEM_ERROR;
1253     dest->state = (void *) ds;
1254     *ds = *ss;
1255     ds->strm = dest;
1256 
1257     ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1258     ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
1259     ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
1260     overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1261     ds->pending_buf = (uchf *) overlay;
1262 
1263     if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1264         ds->pending_buf == Z_NULL) {
1265 	ds->status = INIT_STATE;
1266         deflateEnd (dest);
1267         return Z_MEM_ERROR;
1268     }
1269     /* following zmemcpy do not work for 16-bit MSDOS */
1270     zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1271     zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1272     zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1273     zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1274 
1275     ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1276     ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1277     ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1278 
1279     ds->l_desc.dyn_tree = ds->dyn_ltree;
1280     ds->d_desc.dyn_tree = ds->dyn_dtree;
1281     ds->bl_desc.dyn_tree = ds->bl_tree;
1282 
1283     return Z_OK;
1284 #endif
1285 }
1286 #endif
1287 
1288 /* ===========================================================================
1289  * Return the number of bytes of output which are immediately available
1290  * for output from the decompressor.
1291  */
1292 #if 0
1293 int deflateOutputPending (strm)
1294     z_streamp strm;
1295 {
1296     if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1297 
1298     return ((deflate_state *)(strm->state))->pending;
1299 }
1300 #endif
1301 
1302 /* ===========================================================================
1303  * Read a new buffer from the current input stream, update the adler32
1304  * and total number of bytes read.  All deflate() input goes through
1305  * this function so some applications may wish to modify it to avoid
1306  * allocating a large strm->next_in buffer and copying from it.
1307  * (See also flush_pending()).
1308  */
1309 local int read_buf(strm, buf, size)
1310     z_streamp strm;
1311     Bytef *buf;
1312     unsigned size;
1313 {
1314     unsigned len = strm->avail_in;
1315 
1316     if (len > size) len = size;
1317     if (len == 0) return 0;
1318 
1319     strm->avail_in  -= len;
1320 
1321     if (!((deflate_state *)(strm->state))->noheader) {
1322         strm->adler = adler32(strm->adler, strm->next_in, len);
1323     }
1324     zmemcpy(buf, strm->next_in, len);
1325     strm->next_in  += len;
1326     strm->total_in += len;
1327 
1328     return (int)len;
1329 }
1330 
1331 /* ===========================================================================
1332  * Initialize the "longest match" routines for a new zlib stream
1333  */
1334 local void lm_init (s)
1335     deflate_state *s;
1336 {
1337     s->window_size = (ulg)2L*s->w_size;
1338 
1339     CLEAR_HASH(s);
1340 
1341     /* Set the default configuration parameters:
1342      */
1343     s->max_lazy_match   = configuration_table[s->level].max_lazy;
1344     s->good_match       = configuration_table[s->level].good_length;
1345     s->nice_match       = configuration_table[s->level].nice_length;
1346     s->max_chain_length = configuration_table[s->level].max_chain;
1347 
1348     s->strstart = 0;
1349     s->block_start = 0L;
1350     s->lookahead = 0;
1351     s->match_length = s->prev_length = MIN_MATCH-1;
1352     s->match_available = 0;
1353     s->ins_h = 0;
1354 #ifdef ASMV
1355     match_init(); /* initialize the asm code */
1356 #endif
1357 }
1358 
1359 /* ===========================================================================
1360  * Set match_start to the longest match starting at the given string and
1361  * return its length. Matches shorter or equal to prev_length are discarded,
1362  * in which case the result is equal to prev_length and match_start is
1363  * garbage.
1364  * IN assertions: cur_match is the head of the hash chain for the current
1365  *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1366  * OUT assertion: the match length is not greater than s->lookahead.
1367  */
1368 #ifndef ASMV
1369 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1370  * match.S. The code will be functionally equivalent.
1371  */
1372 #ifndef FASTEST
1373 local uInt longest_match(s, cur_match)
1374     deflate_state *s;
1375     IPos cur_match;                             /* current match */
1376 {
1377     unsigned chain_length = s->max_chain_length;/* max hash chain length */
1378     Bytef *scan = s->window + s->strstart; /* current string */
1379     Bytef *match;                       /* matched string */
1380     int len;                           /* length of current match */
1381     int best_len = s->prev_length;              /* best match length so far */
1382     int nice_match = s->nice_match;             /* stop if match long enough */
1383     IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1384         s->strstart - (IPos)MAX_DIST(s) : NIL;
1385     /* Stop when cur_match becomes <= limit. To simplify the code,
1386      * we prevent matches with the string of window index 0.
1387      */
1388     Posf *prev = s->prev;
1389     uInt wmask = s->w_mask;
1390 
1391 #ifdef UNALIGNED_OK
1392     /* Compare two bytes at a time. Note: this is not always beneficial.
1393      * Try with and without -DUNALIGNED_OK to check.
1394      */
1395     Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1396     ush scan_start = *(ushf*)scan;
1397     ush scan_end   = *(ushf*)(scan+best_len-1);
1398 #else
1399     Bytef *strend = s->window + s->strstart + MAX_MATCH;
1400     Byte scan_end1  = scan[best_len-1];
1401     Byte scan_end   = scan[best_len];
1402 #endif
1403 
1404     /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1405      * It is easy to get rid of this optimization if necessary.
1406      */
1407     Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1408 
1409     /* Do not waste too much time if we already have a good match: */
1410     if (s->prev_length >= s->good_match) {
1411         chain_length >>= 2;
1412     }
1413     /* Do not look for matches beyond the end of the input. This is necessary
1414      * to make deflate deterministic.
1415      */
1416     if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1417 
1418     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1419 
1420     do {
1421         Assert(cur_match < s->strstart, "no future");
1422         match = s->window + cur_match;
1423 
1424         /* Skip to next match if the match length cannot increase
1425          * or if the match length is less than 2:
1426          */
1427 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1428         /* This code assumes sizeof(unsigned short) == 2. Do not use
1429          * UNALIGNED_OK if your compiler uses a different size.
1430          */
1431         if (*(ushf*)(match+best_len-1) != scan_end ||
1432             *(ushf*)match != scan_start) continue;
1433 
1434         /* It is not necessary to compare scan[2] and match[2] since they are
1435          * always equal when the other bytes match, given that the hash keys
1436          * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1437          * strstart+3, +5, ... up to strstart+257. We check for insufficient
1438          * lookahead only every 4th comparison; the 128th check will be made
1439          * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1440          * necessary to put more guard bytes at the end of the window, or
1441          * to check more often for insufficient lookahead.
1442          */
1443         Assert(scan[2] == match[2], "scan[2]?");
1444         scan++, match++;
1445         do {
1446         } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1447                  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1448                  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1449                  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1450                  scan < strend);
1451         /* The funny "do {}" generates better code on most compilers */
1452 
1453         /* Here, scan <= window+strstart+257 */
1454         Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1455         if (*scan == *match) scan++;
1456 
1457         len = (MAX_MATCH - 1) - (int)(strend-scan);
1458         scan = strend - (MAX_MATCH-1);
1459 
1460 #else /* UNALIGNED_OK */
1461 
1462         if (match[best_len]   != scan_end  ||
1463             match[best_len-1] != scan_end1 ||
1464             *match            != *scan     ||
1465             *++match          != scan[1])      continue;
1466 
1467         /* The check at best_len-1 can be removed because it will be made
1468          * again later. (This heuristic is not always a win.)
1469          * It is not necessary to compare scan[2] and match[2] since they
1470          * are always equal when the other bytes match, given that
1471          * the hash keys are equal and that HASH_BITS >= 8.
1472          */
1473         scan += 2, match++;
1474         Assert(*scan == *match, "match[2]?");
1475 
1476         /* We check for insufficient lookahead only every 8th comparison;
1477          * the 256th check will be made at strstart+258.
1478          */
1479         do {
1480         } while (*++scan == *++match && *++scan == *++match &&
1481                  *++scan == *++match && *++scan == *++match &&
1482                  *++scan == *++match && *++scan == *++match &&
1483                  *++scan == *++match && *++scan == *++match &&
1484                  scan < strend);
1485 
1486         Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1487 
1488         len = MAX_MATCH - (int)(strend - scan);
1489         scan = strend - MAX_MATCH;
1490 
1491 #endif /* UNALIGNED_OK */
1492 
1493         if (len > best_len) {
1494             s->match_start = cur_match;
1495             best_len = len;
1496             if (len >= nice_match) break;
1497 #ifdef UNALIGNED_OK
1498             scan_end = *(ushf*)(scan+best_len-1);
1499 #else
1500             scan_end1  = scan[best_len-1];
1501             scan_end   = scan[best_len];
1502 #endif
1503         }
1504     } while ((cur_match = prev[cur_match & wmask]) > limit
1505              && --chain_length != 0);
1506 
1507     if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
1508     return s->lookahead;
1509 }
1510 
1511 #else /* FASTEST */
1512 /* ---------------------------------------------------------------------------
1513  * Optimized version for level == 1 only
1514  */
1515 local uInt longest_match(s, cur_match)
1516     deflate_state *s;
1517     IPos cur_match;                             /* current match */
1518 {
1519     register Bytef *scan = s->window + s->strstart; /* current string */
1520     register Bytef *match;                       /* matched string */
1521     register int len;                           /* length of current match */
1522     register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1523 
1524     /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1525      * It is easy to get rid of this optimization if necessary.
1526      */
1527     Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1528 
1529     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1530 
1531     Assert(cur_match < s->strstart, "no future");
1532 
1533     match = s->window + cur_match;
1534 
1535     /* Return failure if the match length is less than 2:
1536      */
1537     if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
1538 
1539     /* The check at best_len-1 can be removed because it will be made
1540      * again later. (This heuristic is not always a win.)
1541      * It is not necessary to compare scan[2] and match[2] since they
1542      * are always equal when the other bytes match, given that
1543      * the hash keys are equal and that HASH_BITS >= 8.
1544      */
1545     scan += 2, match += 2;
1546     Assert(*scan == *match, "match[2]?");
1547 
1548     /* We check for insufficient lookahead only every 8th comparison;
1549      * the 256th check will be made at strstart+258.
1550      */
1551     do {
1552     } while (*++scan == *++match && *++scan == *++match &&
1553 	     *++scan == *++match && *++scan == *++match &&
1554 	     *++scan == *++match && *++scan == *++match &&
1555 	     *++scan == *++match && *++scan == *++match &&
1556 	     scan < strend);
1557 
1558     Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1559 
1560     len = MAX_MATCH - (int)(strend - scan);
1561 
1562     if (len < MIN_MATCH) return MIN_MATCH - 1;
1563 
1564     s->match_start = cur_match;
1565     return len <= s->lookahead ? len : s->lookahead;
1566 }
1567 #endif /* FASTEST */
1568 #endif /* ASMV */
1569 
1570 #ifdef DEBUG_ZLIB
1571 /* ===========================================================================
1572  * Check that the match at match_start is indeed a match.
1573  */
1574 local void check_match(s, start, match, length)
1575     deflate_state *s;
1576     IPos start, match;
1577     int length;
1578 {
1579     /* check that the match is indeed a match */
1580     if (zmemcmp(s->window + match,
1581                 s->window + start, length) != EQUAL) {
1582         fprintf(stderr, " start %u, match %u, length %d\n",
1583 		start, match, length);
1584         do {
1585 	    fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1586 	} while (--length != 0);
1587         z_error("invalid match");
1588     }
1589     if (z_verbose > 1) {
1590         fprintf(stderr,"\\[%d,%d]", start-match, length);
1591         do { putc(s->window[start++], stderr); } while (--length != 0);
1592     }
1593 }
1594 #else
1595 #  define check_match(s, start, match, length)
1596 #endif
1597 
1598 /* ===========================================================================
1599  * Fill the window when the lookahead becomes insufficient.
1600  * Updates strstart and lookahead.
1601  *
1602  * IN assertion: lookahead < MIN_LOOKAHEAD
1603  * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1604  *    At least one byte has been read, or avail_in == 0; reads are
1605  *    performed for at least two bytes (required for the zip translate_eol
1606  *    option -- not supported here).
1607  */
1608 local void fill_window(s)
1609     deflate_state *s;
1610 {
1611     unsigned n, m;
1612     Posf *p;
1613     unsigned more;    /* Amount of free space at the end of the window. */
1614     uInt wsize = s->w_size;
1615 
1616     do {
1617         more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1618 
1619         /* Deal with !@#$% 64K limit: */
1620         if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1621             more = wsize;
1622 
1623         } else if (more == (unsigned)(-1)) {
1624             /* Very unlikely, but possible on 16 bit machine if strstart == 0
1625              * and lookahead == 1 (input done one byte at time)
1626              */
1627             more--;
1628 
1629         /* If the window is almost full and there is insufficient lookahead,
1630          * move the upper half to the lower one to make room in the upper half.
1631          */
1632         } else if (s->strstart >= wsize+MAX_DIST(s)) {
1633 
1634             zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
1635             s->match_start -= wsize;
1636             s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
1637             s->block_start -= (long) wsize;
1638 
1639             /* Slide the hash table (could be avoided with 32 bit values
1640                at the expense of memory usage). We slide even when level == 0
1641                to keep the hash table consistent if we switch back to level > 0
1642                later. (Using level 0 permanently is not an optimal usage of
1643                zlib, so we don't care about this pathological case.)
1644              */
1645 	    n = s->hash_size;
1646 	    p = &s->head[n];
1647 	    do {
1648 		m = *--p;
1649 		*p = (Pos)(m >= wsize ? m-wsize : NIL);
1650 	    } while (--n);
1651 
1652 	    n = wsize;
1653 #ifndef FASTEST
1654 	    p = &s->prev[n];
1655 	    do {
1656 		m = *--p;
1657 		*p = (Pos)(m >= wsize ? m-wsize : NIL);
1658 		/* If n is not on any hash chain, prev[n] is garbage but
1659 		 * its value will never be used.
1660 		 */
1661 	    } while (--n);
1662 #endif
1663             more += wsize;
1664         }
1665         if (s->strm->avail_in == 0) return;
1666 
1667         /* If there was no sliding:
1668          *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1669          *    more == window_size - lookahead - strstart
1670          * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1671          * => more >= window_size - 2*WSIZE + 2
1672          * In the BIG_MEM or MMAP case (not yet supported),
1673          *   window_size == input_size + MIN_LOOKAHEAD  &&
1674          *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1675          * Otherwise, window_size == 2*WSIZE so more >= 2.
1676          * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1677          */
1678         Assert(more >= 2, "more < 2");
1679 
1680         n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
1681         s->lookahead += n;
1682 
1683         /* Initialize the hash value now that we have some input: */
1684         if (s->lookahead >= MIN_MATCH) {
1685             s->ins_h = s->window[s->strstart];
1686             UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1687 #if MIN_MATCH != 3
1688             Call UPDATE_HASH() MIN_MATCH-3 more times
1689 #endif
1690         }
1691         /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1692          * but this is not important since only literal bytes will be emitted.
1693          */
1694 
1695     } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1696 }
1697 
1698 /* ===========================================================================
1699  * Flush the current block, with given end-of-file flag.
1700  * IN assertion: strstart is set to the end of the current match.
1701  */
1702 #define FLUSH_BLOCK_ONLY(s, eof) { \
1703    _tr_flush_block(s, (s->block_start >= 0L ? \
1704                    (charf *)&s->window[(unsigned)s->block_start] : \
1705                    (charf *)Z_NULL), \
1706 		(ulg)((long)s->strstart - s->block_start), \
1707 		(eof)); \
1708    s->block_start = s->strstart; \
1709    flush_pending(s->strm); \
1710    Tracev((stderr,"[FLUSH]")); \
1711 }
1712 
1713 /* Same but force premature exit if necessary. */
1714 #define FLUSH_BLOCK(s, eof) { \
1715    FLUSH_BLOCK_ONLY(s, eof); \
1716    if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1717 }
1718 
1719 /* ===========================================================================
1720  * Copy without compression as much as possible from the input stream, return
1721  * the current block state.
1722  * This function does not insert new strings in the dictionary since
1723  * uncompressible data is probably not useful. This function is used
1724  * only for the level=0 compression option.
1725  * NOTE: this function should be optimized to avoid extra copying from
1726  * window to pending_buf.
1727  */
1728 local block_state deflate_stored(s, flush)
1729     deflate_state *s;
1730     int flush;
1731 {
1732     /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1733      * to pending_buf_size, and each stored block has a 5 byte header:
1734      */
1735     ulg max_block_size = 0xffff;
1736     ulg max_start;
1737 
1738     if (max_block_size > s->pending_buf_size - 5) {
1739         max_block_size = s->pending_buf_size - 5;
1740     }
1741 
1742     /* Copy as much as possible from input to output: */
1743     for (;;) {
1744         /* Fill the window as much as possible: */
1745         if (s->lookahead <= 1) {
1746 
1747             Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1748 		   s->block_start >= (long)s->w_size, "slide too late");
1749 
1750             fill_window(s);
1751             if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1752 
1753             if (s->lookahead == 0) break; /* flush the current block */
1754         }
1755 	Assert(s->block_start >= 0L, "block gone");
1756 
1757 	s->strstart += s->lookahead;
1758 	s->lookahead = 0;
1759 
1760 	/* Emit a stored block if pending_buf will be full: */
1761  	max_start = s->block_start + max_block_size;
1762         if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1763 	    /* strstart == 0 is possible when wraparound on 16-bit machine */
1764 	    s->lookahead = (uInt)(s->strstart - max_start);
1765 	    s->strstart = (uInt)max_start;
1766             FLUSH_BLOCK(s, 0);
1767 	}
1768 	/* Flush if we may have to slide, otherwise block_start may become
1769          * negative and the data will be gone:
1770          */
1771         if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1772             FLUSH_BLOCK(s, 0);
1773 	}
1774     }
1775     FLUSH_BLOCK(s, flush == Z_FINISH);
1776     return flush == Z_FINISH ? finish_done : block_done;
1777 }
1778 
1779 /* ===========================================================================
1780  * Compress as much as possible from the input stream, return the current
1781  * block state.
1782  * This function does not perform lazy evaluation of matches and inserts
1783  * new strings in the dictionary only for unmatched strings or for short
1784  * matches. It is used only for the fast compression options.
1785  */
1786 local block_state deflate_fast(s, flush)
1787     deflate_state *s;
1788     int flush;
1789 {
1790     IPos hash_head = NIL; /* head of the hash chain */
1791     int bflush;           /* set if current block must be flushed */
1792 
1793     for (;;) {
1794         /* Make sure that we always have enough lookahead, except
1795          * at the end of the input file. We need MAX_MATCH bytes
1796          * for the next match, plus MIN_MATCH bytes to insert the
1797          * string following the next match.
1798          */
1799         if (s->lookahead < MIN_LOOKAHEAD) {
1800             fill_window(s);
1801             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1802 	        return need_more;
1803 	    }
1804             if (s->lookahead == 0) break; /* flush the current block */
1805         }
1806 
1807         /* Insert the string window[strstart .. strstart+2] in the
1808          * dictionary, and set hash_head to the head of the hash chain:
1809          */
1810         if (s->lookahead >= MIN_MATCH) {
1811             INSERT_STRING(s, s->strstart, hash_head);
1812         }
1813 
1814         /* Find the longest match, discarding those <= prev_length.
1815          * At this point we have always match_length < MIN_MATCH
1816          */
1817         if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1818             /* To simplify the code, we prevent matches with the string
1819              * of window index 0 (in particular we have to avoid a match
1820              * of the string with itself at the start of the input file).
1821              */
1822             if (s->strategy != Z_HUFFMAN_ONLY) {
1823                 s->match_length = longest_match (s, hash_head);
1824             }
1825             /* longest_match() sets match_start */
1826         }
1827         if (s->match_length >= MIN_MATCH) {
1828             check_match(s, s->strstart, s->match_start, s->match_length);
1829 
1830             _tr_tally_dist(s, s->strstart - s->match_start,
1831                            s->match_length - MIN_MATCH, bflush);
1832 
1833             s->lookahead -= s->match_length;
1834 
1835             /* Insert new strings in the hash table only if the match length
1836              * is not too large. This saves time but degrades compression.
1837              */
1838 #ifndef FASTEST
1839             if (s->match_length <= s->max_insert_length &&
1840                 s->lookahead >= MIN_MATCH) {
1841                 s->match_length--; /* string at strstart already in hash table */
1842                 do {
1843                     s->strstart++;
1844                     INSERT_STRING(s, s->strstart, hash_head);
1845                     /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1846                      * always MIN_MATCH bytes ahead.
1847                      */
1848                 } while (--s->match_length != 0);
1849                 s->strstart++;
1850             } else
1851 #endif
1852 	    {
1853                 s->strstart += s->match_length;
1854                 s->match_length = 0;
1855                 s->ins_h = s->window[s->strstart];
1856                 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1857 #if MIN_MATCH != 3
1858                 Call UPDATE_HASH() MIN_MATCH-3 more times
1859 #endif
1860                 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1861                  * matter since it will be recomputed at next deflate call.
1862                  */
1863             }
1864         } else {
1865             /* No match, output a literal byte */
1866             Tracevv((stderr,"%c", s->window[s->strstart]));
1867             _tr_tally_lit (s, s->window[s->strstart], bflush);
1868             s->lookahead--;
1869             s->strstart++;
1870         }
1871         if (bflush) FLUSH_BLOCK(s, 0);
1872     }
1873     FLUSH_BLOCK(s, flush == Z_FINISH);
1874     return flush == Z_FINISH ? finish_done : block_done;
1875 }
1876 
1877 /* ===========================================================================
1878  * Same as above, but achieves better compression. We use a lazy
1879  * evaluation for matches: a match is finally adopted only if there is
1880  * no better match at the next window position.
1881  */
1882 local block_state deflate_slow(s, flush)
1883     deflate_state *s;
1884     int flush;
1885 {
1886     IPos hash_head = NIL;    /* head of hash chain */
1887     int bflush;              /* set if current block must be flushed */
1888 
1889     /* Process the input block. */
1890     for (;;) {
1891         /* Make sure that we always have enough lookahead, except
1892          * at the end of the input file. We need MAX_MATCH bytes
1893          * for the next match, plus MIN_MATCH bytes to insert the
1894          * string following the next match.
1895          */
1896         if (s->lookahead < MIN_LOOKAHEAD) {
1897             fill_window(s);
1898             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1899 	        return need_more;
1900 	    }
1901             if (s->lookahead == 0) break; /* flush the current block */
1902         }
1903 
1904         /* Insert the string window[strstart .. strstart+2] in the
1905          * dictionary, and set hash_head to the head of the hash chain:
1906          */
1907         if (s->lookahead >= MIN_MATCH) {
1908             INSERT_STRING(s, s->strstart, hash_head);
1909         }
1910 
1911         /* Find the longest match, discarding those <= prev_length.
1912          */
1913         s->prev_length = s->match_length, s->prev_match = s->match_start;
1914         s->match_length = MIN_MATCH-1;
1915 
1916         if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1917             s->strstart - hash_head <= MAX_DIST(s)) {
1918             /* To simplify the code, we prevent matches with the string
1919              * of window index 0 (in particular we have to avoid a match
1920              * of the string with itself at the start of the input file).
1921              */
1922             if (s->strategy != Z_HUFFMAN_ONLY) {
1923                 s->match_length = longest_match (s, hash_head);
1924             }
1925             /* longest_match() sets match_start */
1926 
1927             if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1928                  (s->match_length == MIN_MATCH &&
1929                   s->strstart - s->match_start > TOO_FAR))) {
1930 
1931                 /* If prev_match is also MIN_MATCH, match_start is garbage
1932                  * but we will ignore the current match anyway.
1933                  */
1934                 s->match_length = MIN_MATCH-1;
1935             }
1936         }
1937         /* If there was a match at the previous step and the current
1938          * match is not better, output the previous match:
1939          */
1940         if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1941             uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1942             /* Do not insert strings in hash table beyond this. */
1943 
1944             check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1945 
1946             _tr_tally_dist(s, s->strstart -1 - s->prev_match,
1947 			   s->prev_length - MIN_MATCH, bflush);
1948 
1949             /* Insert in hash table all strings up to the end of the match.
1950              * strstart-1 and strstart are already inserted. If there is not
1951              * enough lookahead, the last two strings are not inserted in
1952              * the hash table.
1953              */
1954             s->lookahead -= s->prev_length-1;
1955             s->prev_length -= 2;
1956             do {
1957                 if (++s->strstart <= max_insert) {
1958                     INSERT_STRING(s, s->strstart, hash_head);
1959                 }
1960             } while (--s->prev_length != 0);
1961             s->match_available = 0;
1962             s->match_length = MIN_MATCH-1;
1963             s->strstart++;
1964 
1965             if (bflush) FLUSH_BLOCK(s, 0);
1966 
1967         } else if (s->match_available) {
1968             /* If there was no match at the previous position, output a
1969              * single literal. If there was a match but the current match
1970              * is longer, truncate the previous match to a single literal.
1971              */
1972             Tracevv((stderr,"%c", s->window[s->strstart-1]));
1973 	    _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1974 	    if (bflush) {
1975                 FLUSH_BLOCK_ONLY(s, 0);
1976             }
1977             s->strstart++;
1978             s->lookahead--;
1979             if (s->strm->avail_out == 0) return need_more;
1980         } else {
1981             /* There is no previous match to compare with, wait for
1982              * the next step to decide.
1983              */
1984             s->match_available = 1;
1985             s->strstart++;
1986             s->lookahead--;
1987         }
1988     }
1989     Assert (flush != Z_NO_FLUSH, "no flush?");
1990     if (s->match_available) {
1991         Tracevv((stderr,"%c", s->window[s->strstart-1]));
1992         _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1993         s->match_available = 0;
1994     }
1995     FLUSH_BLOCK(s, flush == Z_FINISH);
1996     return flush == Z_FINISH ? finish_done : block_done;
1997 }
1998 /* --- deflate.c */
1999 
2000 /* +++ trees.c */
2001 
2002 /* trees.c -- output deflated data using Huffman coding
2003  * Copyright (C) 1995-2002 Jean-loup Gailly
2004  * For conditions of distribution and use, see copyright notice in zlib.h
2005  */
2006 
2007 /*
2008  *  ALGORITHM
2009  *
2010  *      The "deflation" process uses several Huffman trees. The more
2011  *      common source values are represented by shorter bit sequences.
2012  *
2013  *      Each code tree is stored in a compressed form which is itself
2014  * a Huffman encoding of the lengths of all the code strings (in
2015  * ascending order by source values).  The actual code strings are
2016  * reconstructed from the lengths in the inflate process, as described
2017  * in the deflate specification.
2018  *
2019  *  REFERENCES
2020  *
2021  *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
2022  *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
2023  *
2024  *      Storer, James A.
2025  *          Data Compression:  Methods and Theory, pp. 49-50.
2026  *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
2027  *
2028  *      Sedgewick, R.
2029  *          Algorithms, p290.
2030  *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
2031  */
2032 
2033 /* @(#) $Id: zlib.c,v 1.30 2008/05/05 13:41:30 ad Exp $ */
2034 
2035 /* #define GEN_TREES_H */
2036 
2037 /* #include "deflate.h" */
2038 
2039 #ifdef DEBUG_ZLIB
2040 #  include <ctype.h>
2041 #endif
2042 
2043 /* ===========================================================================
2044  * Constants
2045  */
2046 
2047 #define MAX_BL_BITS 7
2048 /* Bit length codes must not exceed MAX_BL_BITS bits */
2049 
2050 #define END_BLOCK 256
2051 /* end of block literal code */
2052 
2053 #define REP_3_6      16
2054 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
2055 
2056 #define REPZ_3_10    17
2057 /* repeat a zero length 3-10 times  (3 bits of repeat count) */
2058 
2059 #define REPZ_11_138  18
2060 /* repeat a zero length 11-138 times  (7 bits of repeat count) */
2061 
2062 local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
2063    = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};
2064 
2065 local const int extra_dbits[D_CODES] /* extra bits for each distance code */
2066    = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
2067 
2068 local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
2069    = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
2070 
2071 local const uch bl_order[BL_CODES]
2072    = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
2073 /* The lengths of the bit length codes are sent in order of decreasing
2074  * probability, to avoid transmitting the lengths for unused bit length codes.
2075  */
2076 
2077 #define Buf_size (8 * 2*sizeof(char))
2078 /* Number of bits used within bi_buf. (bi_buf might be implemented on
2079  * more than 16 bits on some systems.)
2080  */
2081 
2082 /* ===========================================================================
2083  * Local data. These are initialized only once.
2084  */
2085 
2086 #define DIST_CODE_LEN  512 /* see definition of array dist_code below */
2087 
2088 #if defined(GEN_TREES_H) || !defined(STDC)
2089 /* non ANSI compilers may not accept trees.h */
2090 
2091 local ct_data static_ltree[L_CODES+2];
2092 /* The static literal tree. Since the bit lengths are imposed, there is no
2093  * need for the L_CODES extra codes used during heap construction. However
2094  * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
2095  * below).
2096  */
2097 
2098 local ct_data static_dtree[D_CODES];
2099 /* The static distance tree. (Actually a trivial tree since all codes use
2100  * 5 bits.)
2101  */
2102 
2103 uch _dist_code[DIST_CODE_LEN];
2104 /* Distance codes. The first 256 values correspond to the distances
2105  * 3 .. 258, the last 256 values correspond to the top 8 bits of
2106  * the 15 bit distances.
2107  */
2108 
2109 uch _length_code[MAX_MATCH-MIN_MATCH+1];
2110 /* length code for each normalized match length (0 == MIN_MATCH) */
2111 
2112 local int base_length[LENGTH_CODES];
2113 /* First normalized length for each code (0 = MIN_MATCH) */
2114 
2115 local int base_dist[D_CODES];
2116 /* First normalized distance for each code (0 = distance of 1) */
2117 
2118 #else
2119 /* +++ trees.h */
2120 
2121 /* header created automatically with -DGEN_TREES_H */
2122 
2123 local const ct_data static_ltree[L_CODES+2] = {
2124 {{ 12},{  8}}, {{140},{  8}}, {{ 76},{  8}}, {{204},{  8}}, {{ 44},{  8}},
2125 {{172},{  8}}, {{108},{  8}}, {{236},{  8}}, {{ 28},{  8}}, {{156},{  8}},
2126 {{ 92},{  8}}, {{220},{  8}}, {{ 60},{  8}}, {{188},{  8}}, {{124},{  8}},
2127 {{252},{  8}}, {{  2},{  8}}, {{130},{  8}}, {{ 66},{  8}}, {{194},{  8}},
2128 {{ 34},{  8}}, {{162},{  8}}, {{ 98},{  8}}, {{226},{  8}}, {{ 18},{  8}},
2129 {{146},{  8}}, {{ 82},{  8}}, {{210},{  8}}, {{ 50},{  8}}, {{178},{  8}},
2130 {{114},{  8}}, {{242},{  8}}, {{ 10},{  8}}, {{138},{  8}}, {{ 74},{  8}},
2131 {{202},{  8}}, {{ 42},{  8}}, {{170},{  8}}, {{106},{  8}}, {{234},{  8}},
2132 {{ 26},{  8}}, {{154},{  8}}, {{ 90},{  8}}, {{218},{  8}}, {{ 58},{  8}},
2133 {{186},{  8}}, {{122},{  8}}, {{250},{  8}}, {{  6},{  8}}, {{134},{  8}},
2134 {{ 70},{  8}}, {{198},{  8}}, {{ 38},{  8}}, {{166},{  8}}, {{102},{  8}},
2135 {{230},{  8}}, {{ 22},{  8}}, {{150},{  8}}, {{ 86},{  8}}, {{214},{  8}},
2136 {{ 54},{  8}}, {{182},{  8}}, {{118},{  8}}, {{246},{  8}}, {{ 14},{  8}},
2137 {{142},{  8}}, {{ 78},{  8}}, {{206},{  8}}, {{ 46},{  8}}, {{174},{  8}},
2138 {{110},{  8}}, {{238},{  8}}, {{ 30},{  8}}, {{158},{  8}}, {{ 94},{  8}},
2139 {{222},{  8}}, {{ 62},{  8}}, {{190},{  8}}, {{126},{  8}}, {{254},{  8}},
2140 {{  1},{  8}}, {{129},{  8}}, {{ 65},{  8}}, {{193},{  8}}, {{ 33},{  8}},
2141 {{161},{  8}}, {{ 97},{  8}}, {{225},{  8}}, {{ 17},{  8}}, {{145},{  8}},
2142 {{ 81},{  8}}, {{209},{  8}}, {{ 49},{  8}}, {{177},{  8}}, {{113},{  8}},
2143 {{241},{  8}}, {{  9},{  8}}, {{137},{  8}}, {{ 73},{  8}}, {{201},{  8}},
2144 {{ 41},{  8}}, {{169},{  8}}, {{105},{  8}}, {{233},{  8}}, {{ 25},{  8}},
2145 {{153},{  8}}, {{ 89},{  8}}, {{217},{  8}}, {{ 57},{  8}}, {{185},{  8}},
2146 {{121},{  8}}, {{249},{  8}}, {{  5},{  8}}, {{133},{  8}}, {{ 69},{  8}},
2147 {{197},{  8}}, {{ 37},{  8}}, {{165},{  8}}, {{101},{  8}}, {{229},{  8}},
2148 {{ 21},{  8}}, {{149},{  8}}, {{ 85},{  8}}, {{213},{  8}}, {{ 53},{  8}},
2149 {{181},{  8}}, {{117},{  8}}, {{245},{  8}}, {{ 13},{  8}}, {{141},{  8}},
2150 {{ 77},{  8}}, {{205},{  8}}, {{ 45},{  8}}, {{173},{  8}}, {{109},{  8}},
2151 {{237},{  8}}, {{ 29},{  8}}, {{157},{  8}}, {{ 93},{  8}}, {{221},{  8}},
2152 {{ 61},{  8}}, {{189},{  8}}, {{125},{  8}}, {{253},{  8}}, {{ 19},{  9}},
2153 {{275},{  9}}, {{147},{  9}}, {{403},{  9}}, {{ 83},{  9}}, {{339},{  9}},
2154 {{211},{  9}}, {{467},{  9}}, {{ 51},{  9}}, {{307},{  9}}, {{179},{  9}},
2155 {{435},{  9}}, {{115},{  9}}, {{371},{  9}}, {{243},{  9}}, {{499},{  9}},
2156 {{ 11},{  9}}, {{267},{  9}}, {{139},{  9}}, {{395},{  9}}, {{ 75},{  9}},
2157 {{331},{  9}}, {{203},{  9}}, {{459},{  9}}, {{ 43},{  9}}, {{299},{  9}},
2158 {{171},{  9}}, {{427},{  9}}, {{107},{  9}}, {{363},{  9}}, {{235},{  9}},
2159 {{491},{  9}}, {{ 27},{  9}}, {{283},{  9}}, {{155},{  9}}, {{411},{  9}},
2160 {{ 91},{  9}}, {{347},{  9}}, {{219},{  9}}, {{475},{  9}}, {{ 59},{  9}},
2161 {{315},{  9}}, {{187},{  9}}, {{443},{  9}}, {{123},{  9}}, {{379},{  9}},
2162 {{251},{  9}}, {{507},{  9}}, {{  7},{  9}}, {{263},{  9}}, {{135},{  9}},
2163 {{391},{  9}}, {{ 71},{  9}}, {{327},{  9}}, {{199},{  9}}, {{455},{  9}},
2164 {{ 39},{  9}}, {{295},{  9}}, {{167},{  9}}, {{423},{  9}}, {{103},{  9}},
2165 {{359},{  9}}, {{231},{  9}}, {{487},{  9}}, {{ 23},{  9}}, {{279},{  9}},
2166 {{151},{  9}}, {{407},{  9}}, {{ 87},{  9}}, {{343},{  9}}, {{215},{  9}},
2167 {{471},{  9}}, {{ 55},{  9}}, {{311},{  9}}, {{183},{  9}}, {{439},{  9}},
2168 {{119},{  9}}, {{375},{  9}}, {{247},{  9}}, {{503},{  9}}, {{ 15},{  9}},
2169 {{271},{  9}}, {{143},{  9}}, {{399},{  9}}, {{ 79},{  9}}, {{335},{  9}},
2170 {{207},{  9}}, {{463},{  9}}, {{ 47},{  9}}, {{303},{  9}}, {{175},{  9}},
2171 {{431},{  9}}, {{111},{  9}}, {{367},{  9}}, {{239},{  9}}, {{495},{  9}},
2172 {{ 31},{  9}}, {{287},{  9}}, {{159},{  9}}, {{415},{  9}}, {{ 95},{  9}},
2173 {{351},{  9}}, {{223},{  9}}, {{479},{  9}}, {{ 63},{  9}}, {{319},{  9}},
2174 {{191},{  9}}, {{447},{  9}}, {{127},{  9}}, {{383},{  9}}, {{255},{  9}},
2175 {{511},{  9}}, {{  0},{  7}}, {{ 64},{  7}}, {{ 32},{  7}}, {{ 96},{  7}},
2176 {{ 16},{  7}}, {{ 80},{  7}}, {{ 48},{  7}}, {{112},{  7}}, {{  8},{  7}},
2177 {{ 72},{  7}}, {{ 40},{  7}}, {{104},{  7}}, {{ 24},{  7}}, {{ 88},{  7}},
2178 {{ 56},{  7}}, {{120},{  7}}, {{  4},{  7}}, {{ 68},{  7}}, {{ 36},{  7}},
2179 {{100},{  7}}, {{ 20},{  7}}, {{ 84},{  7}}, {{ 52},{  7}}, {{116},{  7}},
2180 {{  3},{  8}}, {{131},{  8}}, {{ 67},{  8}}, {{195},{  8}}, {{ 35},{  8}},
2181 {{163},{  8}}, {{ 99},{  8}}, {{227},{  8}}
2182 };
2183 
2184 local const ct_data static_dtree[D_CODES] = {
2185 {{ 0},{ 5}}, {{16},{ 5}}, {{ 8},{ 5}}, {{24},{ 5}}, {{ 4},{ 5}},
2186 {{20},{ 5}}, {{12},{ 5}}, {{28},{ 5}}, {{ 2},{ 5}}, {{18},{ 5}},
2187 {{10},{ 5}}, {{26},{ 5}}, {{ 6},{ 5}}, {{22},{ 5}}, {{14},{ 5}},
2188 {{30},{ 5}}, {{ 1},{ 5}}, {{17},{ 5}}, {{ 9},{ 5}}, {{25},{ 5}},
2189 {{ 5},{ 5}}, {{21},{ 5}}, {{13},{ 5}}, {{29},{ 5}}, {{ 3},{ 5}},
2190 {{19},{ 5}}, {{11},{ 5}}, {{27},{ 5}}, {{ 7},{ 5}}, {{23},{ 5}}
2191 };
2192 
2193 const uch _dist_code[DIST_CODE_LEN] = {
2194  0,  1,  2,  3,  4,  4,  5,  5,  6,  6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  8,
2195  8,  8,  8,  8,  9,  9,  9,  9,  9,  9,  9,  9, 10, 10, 10, 10, 10, 10, 10, 10,
2196 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
2197 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
2198 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
2199 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
2200 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
2201 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
2202 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
2203 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15,
2204 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
2205 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
2206 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  0,  0, 16, 17,
2207 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
2208 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2209 24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
2210 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
2211 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
2212 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
2213 27, 27, 27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
2214 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
2215 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
2216 28, 28, 28, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
2217 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
2218 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
2219 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29
2220 };
2221 
2222 const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {
2223  0,  1,  2,  3,  4,  5,  6,  7,  8,  8,  9,  9, 10, 10, 11, 11, 12, 12, 12, 12,
2224 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
2225 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
2226 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
2227 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
2228 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
2229 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2230 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2231 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
2232 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
2233 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
2234 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
2235 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28
2236 };
2237 
2238 local const int base_length[LENGTH_CODES] = {
2239 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
2240 64, 80, 96, 112, 128, 160, 192, 224, 0
2241 };
2242 
2243 local const int base_dist[D_CODES] = {
2244     0,     1,     2,     3,     4,     6,     8,    12,    16,    24,
2245    32,    48,    64,    96,   128,   192,   256,   384,   512,   768,
2246  1024,  1536,  2048,  3072,  4096,  6144,  8192, 12288, 16384, 24576
2247 };
2248 /* --- trees.h */
2249 
2250 #endif /* GEN_TREES_H */
2251 
2252 struct static_tree_desc_s {
2253     const ct_data *static_tree;  /* static tree or NULL */
2254     const intf *extra_bits;      /* extra bits for each code or NULL */
2255     int     extra_base;          /* base index for extra_bits */
2256     int     elems;               /* max number of elements in the tree */
2257     int     max_length;          /* max bit length for the codes */
2258 };
2259 
2260 local static_tree_desc  static_l_desc =
2261 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
2262 
2263 local static_tree_desc  static_d_desc =
2264 {static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};
2265 
2266 local static_tree_desc  static_bl_desc =
2267 {(const ct_data *)0, extra_blbits, 0,   BL_CODES, MAX_BL_BITS};
2268 
2269 /* ===========================================================================
2270  * Local (static) routines in this file.
2271  */
2272 
2273 local void tr_static_init __P((void));
2274 local void init_block     __P((deflate_state *s));
2275 local void pqdownheap     __P((deflate_state *s, ct_data *tree, int k));
2276 local void gen_bitlen     __P((deflate_state *s, tree_desc *desc));
2277 local void gen_codes      __P((ct_data *tree, int max_code, ushf *bl_count));
2278 local void build_tree     __P((deflate_state *s, tree_desc *desc));
2279 local void scan_tree      __P((deflate_state *s, ct_data *tree, int max_code));
2280 local void send_tree      __P((deflate_state *s, ct_data *tree, int max_code));
2281 local int  build_bl_tree  __P((deflate_state *s));
2282 local void send_all_trees __P((deflate_state *s, int lcodes, int dcodes,
2283                               int blcodes));
2284 local void compress_block __P((deflate_state *s, const ct_data *ltree,
2285                               const ct_data *dtree));
2286 local void set_data_type  __P((deflate_state *s));
2287 local unsigned bi_reverse __P((unsigned value, int length));
2288 local void bi_windup      __P((deflate_state *s));
2289 local void bi_flush       __P((deflate_state *s));
2290 local void copy_block     __P((deflate_state *s, charf *buf, unsigned len,
2291                               int header));
2292 
2293 #ifdef GEN_TREES_H
2294 local void gen_trees_header __P((void));
2295 #endif
2296 
2297 #ifndef DEBUG_ZLIB
2298 #  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
2299    /* Send a code of the given tree. c and tree must not have side effects */
2300 
2301 #else /* DEBUG_ZLIB */
2302 #  define send_code(s, c, tree) \
2303      { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
2304        send_bits(s, tree[c].Code, tree[c].Len); }
2305 #endif
2306 
2307 /* ===========================================================================
2308  * Output a short LSB first on the stream.
2309  * IN assertion: there is enough room in pendingBuf.
2310  */
2311 #define put_short(s, w) { \
2312     put_byte(s, (uch)((w) & 0xff)); \
2313     put_byte(s, (uch)((ush)(w) >> 8)); \
2314 }
2315 
2316 /* ===========================================================================
2317  * Send a value on a given number of bits.
2318  * IN assertion: length <= 16 and value fits in length bits.
2319  */
2320 #ifdef DEBUG_ZLIB
2321 local void send_bits      __P((deflate_state *s, int value, int length));
2322 
2323 local void send_bits(s, value, length)
2324     deflate_state *s;
2325     int value;  /* value to send */
2326     int length; /* number of bits */
2327 {
2328     Tracevv((stderr," l %2d v %4x ", length, value));
2329     Assert(length > 0 && length <= 15, "invalid length");
2330     s->bits_sent += (ulg)length;
2331 
2332     /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2333      * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2334      * unused bits in value.
2335      */
2336     if (s->bi_valid > (int)Buf_size - length) {
2337         s->bi_buf |= (value << s->bi_valid);
2338         put_short(s, s->bi_buf);
2339         s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2340         s->bi_valid += length - Buf_size;
2341     } else {
2342         s->bi_buf |= value << s->bi_valid;
2343         s->bi_valid += length;
2344     }
2345 }
2346 #else /* !DEBUG_ZLIB */
2347 
2348 #define send_bits(s, value, length) \
2349 { int len = length;\
2350   if (s->bi_valid > (int)Buf_size - len) {\
2351     int val = value;\
2352     s->bi_buf |= (val << s->bi_valid);\
2353     put_short(s, s->bi_buf);\
2354     s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2355     s->bi_valid += len - Buf_size;\
2356   } else {\
2357     s->bi_buf |= (value) << s->bi_valid;\
2358     s->bi_valid += len;\
2359   }\
2360 }
2361 #endif /* DEBUG_ZLIB */
2362 
2363 
2364 /* ===========================================================================
2365  * Initialize the various 'constant' tables.
2366  */
2367 local void tr_static_init()
2368 {
2369 #if defined(GEN_TREES_H) || !defined(STDC)
2370     static int static_init_done = 0;
2371     int n;        /* iterates over tree elements */
2372     int bits;     /* bit counter */
2373     int length;   /* length value */
2374     int code;     /* code value */
2375     int dist;     /* distance index */
2376     ush bl_count[MAX_BITS+1];
2377     /* number of codes at each bit length for an optimal tree */
2378 
2379     if (static_init_done) return;
2380 
2381     /* For some embedded targets, global variables are not initialized: */
2382     static_l_desc.static_tree = static_ltree;
2383     static_l_desc.extra_bits = extra_lbits;
2384     static_d_desc.static_tree = static_dtree;
2385     static_d_desc.extra_bits = extra_dbits;
2386     static_bl_desc.extra_bits = extra_blbits;
2387 
2388     /* Initialize the mapping length (0..255) -> length code (0..28) */
2389     length = 0;
2390     for (code = 0; code < LENGTH_CODES-1; code++) {
2391         base_length[code] = length;
2392         for (n = 0; n < (1<<extra_lbits[code]); n++) {
2393             _length_code[length++] = (uch)code;
2394         }
2395     }
2396     Assert (length == 256, "tr_static_init: length != 256");
2397     /* Note that the length 255 (match length 258) can be represented
2398      * in two different ways: code 284 + 5 bits or code 285, so we
2399      * overwrite length_code[255] to use the best encoding:
2400      */
2401     _length_code[length-1] = (uch)code;
2402 
2403     /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2404     dist = 0;
2405     for (code = 0 ; code < 16; code++) {
2406         base_dist[code] = dist;
2407         for (n = 0; n < (1<<extra_dbits[code]); n++) {
2408             _dist_code[dist++] = (uch)code;
2409         }
2410     }
2411     Assert (dist == 256, "tr_static_init: dist != 256");
2412     dist >>= 7; /* from now on, all distances are divided by 128 */
2413     for ( ; code < D_CODES; code++) {
2414         base_dist[code] = dist << 7;
2415         for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2416             _dist_code[256 + dist++] = (uch)code;
2417         }
2418     }
2419     Assert (dist == 256, "tr_static_init: 256+dist != 512");
2420 
2421     /* Construct the codes of the static literal tree */
2422     for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2423     n = 0;
2424     while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2425     while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2426     while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2427     while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2428     /* Codes 286 and 287 do not exist, but we must include them in the
2429      * tree construction to get a canonical Huffman tree (longest code
2430      * all ones)
2431      */
2432     gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2433 
2434     /* The static distance tree is trivial: */
2435     for (n = 0; n < D_CODES; n++) {
2436         static_dtree[n].Len = 5;
2437         static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2438     }
2439     static_init_done = 1;
2440 
2441 #  ifdef GEN_TREES_H
2442     gen_trees_header();
2443 #  endif
2444 #endif /* defined(GEN_TREES_H) || !defined(STDC) */
2445 }
2446 
2447 /* ===========================================================================
2448  * Genererate the file trees.h describing the static trees.
2449  */
2450 #ifdef GEN_TREES_H
2451 #  ifndef DEBUG_ZLIB
2452 #    include <stdio.h>
2453 #  endif
2454 
2455 #  define SEPARATOR(i, last, width) \
2456       ((i) == (last)? "\n};\n\n" :    \
2457        ((i) % (width) == (width)-1 ? ",\n" : ", "))
2458 
2459 void gen_trees_header()
2460 {
2461     FILE *header = fopen("trees.h", "w");
2462     int i;
2463 
2464     Assert (header != NULL, "Can't open trees.h");
2465     fprintf(header,
2466 	    "/* header created automatically with -DGEN_TREES_H */\n\n");
2467 
2468     fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
2469     for (i = 0; i < L_CODES+2; i++) {
2470 	fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
2471 		static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
2472     }
2473 
2474     fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
2475     for (i = 0; i < D_CODES; i++) {
2476 	fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
2477 		static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
2478     }
2479 
2480     fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n");
2481     for (i = 0; i < DIST_CODE_LEN; i++) {
2482 	fprintf(header, "%2u%s", _dist_code[i],
2483 		SEPARATOR(i, DIST_CODE_LEN-1, 20));
2484     }
2485 
2486     fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
2487     for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
2488 	fprintf(header, "%2u%s", _length_code[i],
2489 		SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
2490     }
2491 
2492     fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
2493     for (i = 0; i < LENGTH_CODES; i++) {
2494 	fprintf(header, "%1u%s", base_length[i],
2495 		SEPARATOR(i, LENGTH_CODES-1, 20));
2496     }
2497 
2498     fprintf(header, "local const int base_dist[D_CODES] = {\n");
2499     for (i = 0; i < D_CODES; i++) {
2500 	fprintf(header, "%5u%s", base_dist[i],
2501 		SEPARATOR(i, D_CODES-1, 10));
2502     }
2503 
2504     fclose(header);
2505 }
2506 #endif /* GEN_TREES_H */
2507 
2508 /* ===========================================================================
2509  * Initialize the tree data structures for a new zlib stream.
2510  */
2511 void _tr_init(s)
2512     deflate_state *s;
2513 {
2514     tr_static_init();
2515 
2516     s->l_desc.dyn_tree = s->dyn_ltree;
2517     s->l_desc.stat_desc = &static_l_desc;
2518 
2519     s->d_desc.dyn_tree = s->dyn_dtree;
2520     s->d_desc.stat_desc = &static_d_desc;
2521 
2522     s->bl_desc.dyn_tree = s->bl_tree;
2523     s->bl_desc.stat_desc = &static_bl_desc;
2524 
2525     s->bi_buf = 0;
2526     s->bi_valid = 0;
2527     s->last_eob_len = 8; /* enough lookahead for inflate */
2528 #ifdef DEBUG_ZLIB
2529     s->compressed_len = 0L;
2530     s->bits_sent = 0L;
2531 #endif
2532 
2533     /* Initialize the first block of the first file: */
2534     init_block(s);
2535 }
2536 
2537 /* ===========================================================================
2538  * Initialize a new block.
2539  */
2540 local void init_block(s)
2541     deflate_state *s;
2542 {
2543     int n; /* iterates over tree elements */
2544 
2545     /* Initialize the trees. */
2546     for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
2547     for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
2548     for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2549 
2550     s->dyn_ltree[END_BLOCK].Freq = 1;
2551     s->opt_len = s->static_len = 0L;
2552     s->last_lit = s->matches = 0;
2553 }
2554 
2555 #define SMALLEST 1
2556 /* Index within the heap array of least frequent node in the Huffman tree */
2557 
2558 
2559 /* ===========================================================================
2560  * Remove the smallest element from the heap and recreate the heap with
2561  * one less element. Updates heap and heap_len.
2562  */
2563 #define pqremove(s, tree, top) \
2564 {\
2565     top = s->heap[SMALLEST]; \
2566     s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2567     pqdownheap(s, tree, SMALLEST); \
2568 }
2569 
2570 /* ===========================================================================
2571  * Compares to subtrees, using the tree depth as tie breaker when
2572  * the subtrees have equal frequency. This minimizes the worst case length.
2573  */
2574 #define smaller(tree, n, m, depth) \
2575    (tree[n].Freq < tree[m].Freq || \
2576    (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2577 
2578 /* ===========================================================================
2579  * Restore the heap property by moving down the tree starting at node k,
2580  * exchanging a node with the smallest of its two sons if necessary, stopping
2581  * when the heap property is re-established (each father smaller than its
2582  * two sons).
2583  */
2584 local void pqdownheap(s, tree, k)
2585     deflate_state *s;
2586     ct_data *tree;  /* the tree to restore */
2587     int k;               /* node to move down */
2588 {
2589     int v = s->heap[k];
2590     int j = k << 1;  /* left son of k */
2591     while (j <= s->heap_len) {
2592         /* Set j to the smallest of the two sons: */
2593         if (j < s->heap_len &&
2594             smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2595             j++;
2596         }
2597         /* Exit if v is smaller than both sons */
2598         if (smaller(tree, v, s->heap[j], s->depth)) break;
2599 
2600         /* Exchange v with the smallest son */
2601         s->heap[k] = s->heap[j];  k = j;
2602 
2603         /* And continue down the tree, setting j to the left son of k */
2604         j <<= 1;
2605     }
2606     s->heap[k] = v;
2607 }
2608 
2609 /* ===========================================================================
2610  * Compute the optimal bit lengths for a tree and update the total bit length
2611  * for the current block.
2612  * IN assertion: the fields freq and dad are set, heap[heap_max] and
2613  *    above are the tree nodes sorted by increasing frequency.
2614  * OUT assertions: the field len is set to the optimal bit length, the
2615  *     array bl_count contains the frequencies for each bit length.
2616  *     The length opt_len is updated; static_len is also updated if stree is
2617  *     not null.
2618  */
2619 local void gen_bitlen(s, desc)
2620     deflate_state *s;
2621     tree_desc *desc;    /* the tree descriptor */
2622 {
2623     ct_data *tree        = desc->dyn_tree;
2624     int max_code         = desc->max_code;
2625     const ct_data *stree = desc->stat_desc->static_tree;
2626     const intf *extra    = desc->stat_desc->extra_bits;
2627     int base             = desc->stat_desc->extra_base;
2628     int max_length       = desc->stat_desc->max_length;
2629     int h;              /* heap index */
2630     int n, m;           /* iterate over the tree elements */
2631     int bits;           /* bit length */
2632     int xbits;          /* extra bits */
2633     ush f;              /* frequency */
2634     int overflow = 0;   /* number of elements with bit length too large */
2635 
2636     for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2637 
2638     /* In a first pass, compute the optimal bit lengths (which may
2639      * overflow in the case of the bit length tree).
2640      */
2641     tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2642 
2643     for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2644         n = s->heap[h];
2645         bits = tree[tree[n].Dad].Len + 1;
2646         if (bits > max_length) bits = max_length, overflow++;
2647         tree[n].Len = (ush)bits;
2648         /* We overwrite tree[n].Dad which is no longer needed */
2649 
2650         if (n > max_code) continue; /* not a leaf node */
2651 
2652         s->bl_count[bits]++;
2653         xbits = 0;
2654         if (n >= base) xbits = extra[n-base];
2655         f = tree[n].Freq;
2656         s->opt_len += (ulg)f * (bits + xbits);
2657         if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2658     }
2659     if (overflow == 0) return;
2660 
2661     Trace((stderr,"\nbit length overflow\n"));
2662     /* This happens for example on obj2 and pic of the Calgary corpus */
2663 
2664     /* Find the first bit length which could increase: */
2665     do {
2666         bits = max_length-1;
2667         while (s->bl_count[bits] == 0) bits--;
2668         s->bl_count[bits]--;      /* move one leaf down the tree */
2669         s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2670         s->bl_count[max_length]--;
2671         /* The brother of the overflow item also moves one step up,
2672          * but this does not affect bl_count[max_length]
2673          */
2674         overflow -= 2;
2675     } while (overflow > 0);
2676 
2677     /* Now recompute all bit lengths, scanning in increasing frequency.
2678      * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2679      * lengths instead of fixing only the wrong ones. This idea is taken
2680      * from 'ar' written by Haruhiko Okumura.)
2681      */
2682     for (bits = max_length; bits != 0; bits--) {
2683         n = s->bl_count[bits];
2684         while (n != 0) {
2685             m = s->heap[--h];
2686             if (m > max_code) continue;
2687             if (tree[m].Len != (unsigned) bits) {
2688                 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2689                 s->opt_len += ((long)bits - (long)tree[m].Len)
2690                               *(long)tree[m].Freq;
2691                 tree[m].Len = (ush)bits;
2692             }
2693             n--;
2694         }
2695     }
2696 }
2697 
2698 /* ===========================================================================
2699  * Generate the codes for a given tree and bit counts (which need not be
2700  * optimal).
2701  * IN assertion: the array bl_count contains the bit length statistics for
2702  * the given tree and the field len is set for all tree elements.
2703  * OUT assertion: the field code is set for all tree elements of non
2704  *     zero code length.
2705  */
2706 local void gen_codes (tree, max_code, bl_count)
2707     ct_data *tree;             /* the tree to decorate */
2708     int max_code;              /* largest code with non zero frequency */
2709     ushf *bl_count;            /* number of codes at each bit length */
2710 {
2711     ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2712     ush code = 0;              /* running code value */
2713     int bits;                  /* bit index */
2714     int n;                     /* code index */
2715 
2716     /* The distribution counts are first used to generate the code values
2717      * without bit reversal.
2718      */
2719     for (bits = 1; bits <= MAX_BITS; bits++) {
2720         next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2721     }
2722     /* Check that the bit counts in bl_count are consistent. The last code
2723      * must be all ones.
2724      */
2725     Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2726             "inconsistent bit counts");
2727     Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2728 
2729     for (n = 0;  n <= max_code; n++) {
2730         int len = tree[n].Len;
2731         if (len == 0) continue;
2732         /* Now reverse the bits */
2733         tree[n].Code = bi_reverse(next_code[len]++, len);
2734 
2735         Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2736              n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2737     }
2738 }
2739 
2740 /* ===========================================================================
2741  * Construct one Huffman tree and assigns the code bit strings and lengths.
2742  * Update the total bit length for the current block.
2743  * IN assertion: the field freq is set for all tree elements.
2744  * OUT assertions: the fields len and code are set to the optimal bit length
2745  *     and corresponding code. The length opt_len is updated; static_len is
2746  *     also updated if stree is not null. The field max_code is set.
2747  */
2748 local void build_tree(s, desc)
2749     deflate_state *s;
2750     tree_desc *desc; /* the tree descriptor */
2751 {
2752     ct_data *tree         = desc->dyn_tree;
2753     const ct_data *stree  = desc->stat_desc->static_tree;
2754     int elems             = desc->stat_desc->elems;
2755     int n, m;          /* iterate over heap elements */
2756     int max_code = -1; /* largest code with non zero frequency */
2757     int node;          /* new node being created */
2758 
2759     /* Construct the initial heap, with least frequent element in
2760      * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2761      * heap[0] is not used.
2762      */
2763     s->heap_len = 0, s->heap_max = HEAP_SIZE;
2764 
2765     for (n = 0; n < elems; n++) {
2766         if (tree[n].Freq != 0) {
2767             s->heap[++(s->heap_len)] = max_code = n;
2768             s->depth[n] = 0;
2769         } else {
2770             tree[n].Len = 0;
2771         }
2772     }
2773 
2774     /* The pkzip format requires that at least one distance code exists,
2775      * and that at least one bit should be sent even if there is only one
2776      * possible code. So to avoid special checks later on we force at least
2777      * two codes of non zero frequency.
2778      */
2779     while (s->heap_len < 2) {
2780         node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2781         tree[node].Freq = 1;
2782         s->depth[node] = 0;
2783         s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2784         /* node is 0 or 1 so it does not have extra bits */
2785     }
2786     desc->max_code = max_code;
2787 
2788     /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2789      * establish sub-heaps of increasing lengths:
2790      */
2791     for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2792 
2793     /* Construct the Huffman tree by repeatedly combining the least two
2794      * frequent nodes.
2795      */
2796     node = elems;              /* next internal node of the tree */
2797     do {
2798         pqremove(s, tree, n);  /* n = node of least frequency */
2799         m = s->heap[SMALLEST]; /* m = node of next least frequency */
2800 
2801         s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2802         s->heap[--(s->heap_max)] = m;
2803 
2804         /* Create a new node father of n and m */
2805         tree[node].Freq = tree[n].Freq + tree[m].Freq;
2806         s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2807         tree[n].Dad = tree[m].Dad = (ush)node;
2808 #ifdef DUMP_BL_TREE
2809         if (tree == s->bl_tree) {
2810             fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2811                     node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2812         }
2813 #endif
2814         /* and insert the new node in the heap */
2815         s->heap[SMALLEST] = node++;
2816         pqdownheap(s, tree, SMALLEST);
2817 
2818     } while (s->heap_len >= 2);
2819 
2820     s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2821 
2822     /* At this point, the fields freq and dad are set. We can now
2823      * generate the bit lengths.
2824      */
2825     gen_bitlen(s, (tree_desc *)desc);
2826 
2827     /* The field len is now set, we can generate the bit codes */
2828     gen_codes ((ct_data *)tree, max_code, s->bl_count);
2829 }
2830 
2831 /* ===========================================================================
2832  * Scan a literal or distance tree to determine the frequencies of the codes
2833  * in the bit length tree.
2834  */
2835 local void scan_tree (s, tree, max_code)
2836     deflate_state *s;
2837     ct_data *tree;   /* the tree to be scanned */
2838     int max_code;    /* and its largest code of non zero frequency */
2839 {
2840     int n;                     /* iterates over all tree elements */
2841     int prevlen = -1;          /* last emitted length */
2842     int curlen;                /* length of current code */
2843     int nextlen = tree[0].Len; /* length of next code */
2844     int count = 0;             /* repeat count of the current code */
2845     int max_count = 7;         /* max repeat count */
2846     int min_count = 4;         /* min repeat count */
2847 
2848     if (nextlen == 0) max_count = 138, min_count = 3;
2849     tree[max_code+1].Len = (ush)0xffff; /* guard */
2850 
2851     for (n = 0; n <= max_code; n++) {
2852         curlen = nextlen; nextlen = tree[n+1].Len;
2853         if (++count < max_count && curlen == nextlen) {
2854             continue;
2855         } else if (count < min_count) {
2856             s->bl_tree[curlen].Freq += count;
2857         } else if (curlen != 0) {
2858             if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2859             s->bl_tree[REP_3_6].Freq++;
2860         } else if (count <= 10) {
2861             s->bl_tree[REPZ_3_10].Freq++;
2862         } else {
2863             s->bl_tree[REPZ_11_138].Freq++;
2864         }
2865         count = 0; prevlen = curlen;
2866         if (nextlen == 0) {
2867             max_count = 138, min_count = 3;
2868         } else if (curlen == nextlen) {
2869             max_count = 6, min_count = 3;
2870         } else {
2871             max_count = 7, min_count = 4;
2872         }
2873     }
2874 }
2875 
2876 /* ===========================================================================
2877  * Send a literal or distance tree in compressed form, using the codes in
2878  * bl_tree.
2879  */
2880 local void send_tree (s, tree, max_code)
2881     deflate_state *s;
2882     ct_data *tree; /* the tree to be scanned */
2883     int max_code;       /* and its largest code of non zero frequency */
2884 {
2885     int n;                     /* iterates over all tree elements */
2886     int prevlen = -1;          /* last emitted length */
2887     int curlen;                /* length of current code */
2888     int nextlen = tree[0].Len; /* length of next code */
2889     int count = 0;             /* repeat count of the current code */
2890     int max_count = 7;         /* max repeat count */
2891     int min_count = 4;         /* min repeat count */
2892 
2893     /* tree[max_code+1].Len = -1; */  /* guard already set */
2894     if (nextlen == 0) max_count = 138, min_count = 3;
2895 
2896     for (n = 0; n <= max_code; n++) {
2897         curlen = nextlen; nextlen = tree[n+1].Len;
2898         if (++count < max_count && curlen == nextlen) {
2899             continue;
2900         } else if (count < min_count) {
2901             do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2902 
2903         } else if (curlen != 0) {
2904             if (curlen != prevlen) {
2905                 send_code(s, curlen, s->bl_tree); count--;
2906             }
2907             Assert(count >= 3 && count <= 6, " 3_6?");
2908             send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2909 
2910         } else if (count <= 10) {
2911             send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2912 
2913         } else {
2914             send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2915         }
2916         count = 0; prevlen = curlen;
2917         if (nextlen == 0) {
2918             max_count = 138, min_count = 3;
2919         } else if (curlen == nextlen) {
2920             max_count = 6, min_count = 3;
2921         } else {
2922             max_count = 7, min_count = 4;
2923         }
2924     }
2925 }
2926 
2927 /* ===========================================================================
2928  * Construct the Huffman tree for the bit lengths and return the index in
2929  * bl_order of the last bit length code to send.
2930  */
2931 local int build_bl_tree(s)
2932     deflate_state *s;
2933 {
2934     int max_blindex;  /* index of last bit length code of non zero freq */
2935 
2936     /* Determine the bit length frequencies for literal and distance trees */
2937     scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2938     scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2939 
2940     /* Build the bit length tree: */
2941     build_tree(s, (tree_desc *)(&(s->bl_desc)));
2942     /* opt_len now includes the length of the tree representations, except
2943      * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2944      */
2945 
2946     /* Determine the number of bit length codes to send. The pkzip format
2947      * requires that at least 4 bit length codes be sent. (appnote.txt says
2948      * 3 but the actual value used is 4.)
2949      */
2950     for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2951         if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2952     }
2953     /* Update opt_len to include the bit length tree and counts */
2954     s->opt_len += 3*(max_blindex+1) + 5+5+4;
2955     Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2956             s->opt_len, s->static_len));
2957 
2958     return max_blindex;
2959 }
2960 
2961 /* ===========================================================================
2962  * Send the header for a block using dynamic Huffman trees: the counts, the
2963  * lengths of the bit length codes, the literal tree and the distance tree.
2964  * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2965  */
2966 local void send_all_trees(s, lcodes, dcodes, blcodes)
2967     deflate_state *s;
2968     int lcodes, dcodes, blcodes; /* number of codes for each tree */
2969 {
2970     int rank;                    /* index in bl_order */
2971 
2972     Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2973     Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2974             "too many codes");
2975     Tracev((stderr, "\nbl counts: "));
2976     send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2977     send_bits(s, dcodes-1,   5);
2978     send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */
2979     for (rank = 0; rank < blcodes; rank++) {
2980         Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2981         send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2982     }
2983     Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2984 
2985     send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2986     Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2987 
2988     send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2989     Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2990 }
2991 
2992 /* ===========================================================================
2993  * Send a stored block
2994  */
2995 void _tr_stored_block(s, buf, stored_len, eof)
2996     deflate_state *s;
2997     charf *buf;       /* input block */
2998     ulg stored_len;   /* length of input block */
2999     int eof;          /* true if this is the last block for a file */
3000 {
3001     send_bits(s, (STORED_BLOCK<<1)+eof, 3);  /* send block type */
3002 #ifdef DEBUG_ZLIB
3003     s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
3004     s->compressed_len += (stored_len + 4) << 3;
3005 #endif
3006     copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
3007 }
3008 
3009 /* Send just the `stored block' type code without any length bytes or data.
3010  */
3011 void _tr_stored_type_only(s)
3012     deflate_state *s;
3013 {
3014     send_bits(s, (STORED_BLOCK << 1), 3);
3015     bi_windup(s);
3016 #ifdef DEBUG_ZLIB
3017     s->compressed_len = (s->compressed_len + 3) & ~7L;
3018 #endif
3019 }
3020 
3021 /* ===========================================================================
3022  * Send one empty static block to give enough lookahead for inflate.
3023  * This takes 10 bits, of which 7 may remain in the bit buffer.
3024  * The current inflate code requires 9 bits of lookahead. If the
3025  * last two codes for the previous block (real code plus EOB) were coded
3026  * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
3027  * the last real code. In this case we send two empty static blocks instead
3028  * of one. (There are no problems if the previous block is stored or fixed.)
3029  * To simplify the code, we assume the worst case of last real code encoded
3030  * on one bit only.
3031  */
3032 void _tr_align(s)
3033     deflate_state *s;
3034 {
3035     send_bits(s, STATIC_TREES<<1, 3);
3036     send_code(s, END_BLOCK, static_ltree);
3037 #ifdef DEBUG_ZLIB
3038     s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
3039 #endif
3040     bi_flush(s);
3041     /* Of the 10 bits for the empty block, we have already sent
3042      * (10 - bi_valid) bits. The lookahead for the last real code (before
3043      * the EOB of the previous block) was thus at least one plus the length
3044      * of the EOB plus what we have just sent of the empty static block.
3045      */
3046     if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
3047         send_bits(s, STATIC_TREES<<1, 3);
3048         send_code(s, END_BLOCK, static_ltree);
3049 #ifdef DEBUG_ZLIB
3050         s->compressed_len += 10L;
3051 #endif
3052         bi_flush(s);
3053     }
3054     s->last_eob_len = 7;
3055 }
3056 
3057 /* ===========================================================================
3058  * Determine the best encoding for the current block: dynamic trees, static
3059  * trees or store, and output the encoded block to the zip file.
3060  */
3061 void _tr_flush_block(s, buf, stored_len, eof)
3062     deflate_state *s;
3063     charf *buf;       /* input block, or NULL if too old */
3064     ulg stored_len;   /* length of input block */
3065     int eof;          /* true if this is the last block for a file */
3066 {
3067     ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
3068     int max_blindex = 0;  /* index of last bit length code of non zero freq */
3069 
3070     /* Build the Huffman trees unless a stored block is forced */
3071     if (s->level > 0) {
3072 
3073 	 /* Check if the file is ascii or binary */
3074 	if (s->data_type == Z_UNKNOWN) set_data_type(s);
3075 
3076 	/* Construct the literal and distance trees */
3077 	build_tree(s, (tree_desc *)(&(s->l_desc)));
3078 	Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
3079 		s->static_len));
3080 
3081 	build_tree(s, (tree_desc *)(&(s->d_desc)));
3082 	Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
3083 		s->static_len));
3084 	/* At this point, opt_len and static_len are the total bit lengths of
3085 	 * the compressed block data, excluding the tree representations.
3086 	 */
3087 
3088 	/* Build the bit length tree for the above two trees, and get the index
3089 	 * in bl_order of the last bit length code to send.
3090 	 */
3091 	max_blindex = build_bl_tree(s);
3092 
3093 	/* Determine the best encoding. Compute first the block length in bytes*/
3094 	opt_lenb = (s->opt_len+3+7)>>3;
3095 	static_lenb = (s->static_len+3+7)>>3;
3096 
3097 	Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
3098 		opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
3099 		s->last_lit));
3100 
3101 	if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
3102 
3103     } else {
3104         Assert(buf != (char*)0, "lost buf");
3105 	opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
3106     }
3107 
3108 #ifdef FORCE_STORED
3109     if (buf != (char*)0) { /* force stored block */
3110 #else
3111     if (stored_len+4 <= opt_lenb && buf != (char*)0) {
3112                        /* 4: two words for the lengths */
3113 #endif
3114         /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
3115          * Otherwise we can't have processed more than WSIZE input bytes since
3116          * the last block flush, because compression would have been
3117          * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
3118          * transform a block into a stored block.
3119          */
3120         _tr_stored_block(s, buf, stored_len, eof);
3121 
3122 #ifdef FORCE_STATIC
3123     } else if (static_lenb >= 0) { /* force static trees */
3124 #else
3125     } else if (static_lenb == opt_lenb) {
3126 #endif
3127         send_bits(s, (STATIC_TREES<<1)+eof, 3);
3128         compress_block(s, (const ct_data *)static_ltree, (const ct_data *)static_dtree);
3129 #ifdef DEBUG_ZLIB
3130         s->compressed_len += 3 + s->static_len;
3131 #endif
3132     } else {
3133         send_bits(s, (DYN_TREES<<1)+eof, 3);
3134         send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
3135                        max_blindex+1);
3136         compress_block(s, (const ct_data *)s->dyn_ltree, (const ct_data *)s->dyn_dtree);
3137 #ifdef DEBUG_ZLIB
3138         s->compressed_len += 3 + s->opt_len;
3139 #endif
3140     }
3141     Assert (s->compressed_len == s->bits_sent, "bad compressed size");
3142     /* The above check is made mod 2^32, for files larger than 512 MB
3143      * and uLong implemented on 32 bits.
3144      */
3145     init_block(s);
3146 
3147     if (eof) {
3148         bi_windup(s);
3149 #ifdef DEBUG_ZLIB
3150         s->compressed_len += 7;  /* align on byte boundary */
3151 #endif
3152     }
3153     Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
3154            s->compressed_len-7*eof));
3155 }
3156 
3157 /* ===========================================================================
3158  * Save the match info and tally the frequency counts. Return true if
3159  * the current block must be flushed.
3160  */
3161 #if 0
3162 int _tr_tally (s, dist, lc)
3163     deflate_state *s;
3164     unsigned dist;  /* distance of matched string */
3165     unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
3166 {
3167     s->d_buf[s->last_lit] = (ush)dist;
3168     s->l_buf[s->last_lit++] = (uch)lc;
3169     if (dist == 0) {
3170         /* lc is the unmatched char */
3171         s->dyn_ltree[lc].Freq++;
3172     } else {
3173         s->matches++;
3174         /* Here, lc is the match length - MIN_MATCH */
3175         dist--;             /* dist = match distance - 1 */
3176         Assert((ush)dist < (ush)MAX_DIST(s) &&
3177                (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
3178                (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");
3179 
3180         s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
3181         s->dyn_dtree[d_code(dist)].Freq++;
3182     }
3183 
3184 #ifdef TRUNCATE_BLOCK
3185     /* Try to guess if it is profitable to stop the current block here */
3186     if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
3187         /* Compute an upper bound for the compressed length */
3188         ulg out_length = (ulg)s->last_lit*8L;
3189         ulg in_length = (ulg)((long)s->strstart - s->block_start);
3190         int dcode;
3191         for (dcode = 0; dcode < D_CODES; dcode++) {
3192             out_length += (ulg)s->dyn_dtree[dcode].Freq *
3193                 (5L+extra_dbits[dcode]);
3194         }
3195         out_length >>= 3;
3196         Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
3197                s->last_lit, in_length, out_length,
3198                100L - out_length*100L/in_length));
3199         if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
3200     }
3201 #endif
3202     return (s->last_lit == s->lit_bufsize-1);
3203     /* We avoid equality with lit_bufsize because of wraparound at 64K
3204      * on 16 bit machines and because stored blocks are restricted to
3205      * 64K-1 bytes.
3206      */
3207 }
3208 #endif
3209 
3210 /* ===========================================================================
3211  * Send the block data compressed using the given Huffman trees
3212  */
3213 local void compress_block(s, ltree, dtree)
3214     deflate_state *s;
3215     const ct_data *ltree; /* literal tree */
3216     const ct_data *dtree; /* distance tree */
3217 {
3218     unsigned dist;      /* distance of matched string */
3219     int lc;             /* match length or unmatched char (if dist == 0) */
3220     unsigned lx = 0;    /* running index in l_buf */
3221     unsigned code;      /* the code to send */
3222     int extra;          /* number of extra bits to send */
3223 
3224     if (s->last_lit != 0) do {
3225         dist = s->d_buf[lx];
3226         lc = s->l_buf[lx++];
3227         if (dist == 0) {
3228             send_code(s, lc, ltree); /* send a literal byte */
3229             Tracecv(isgraph(lc), (stderr," '%c' ", lc));
3230         } else {
3231             /* Here, lc is the match length - MIN_MATCH */
3232             code = _length_code[lc];
3233             send_code(s, code+LITERALS+1, ltree); /* send the length code */
3234             extra = extra_lbits[code];
3235             if (extra != 0) {
3236                 lc -= base_length[code];
3237                 send_bits(s, lc, extra);       /* send the extra length bits */
3238             }
3239             dist--; /* dist is now the match distance - 1 */
3240             code = d_code(dist);
3241             Assert (code < D_CODES, "bad d_code");
3242 
3243             send_code(s, code, dtree);       /* send the distance code */
3244             extra = extra_dbits[code];
3245             if (extra != 0) {
3246                 dist -= base_dist[code];
3247                 send_bits(s, dist, extra);   /* send the extra distance bits */
3248             }
3249         } /* literal or match pair ? */
3250 
3251         /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
3252         Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
3253 
3254     } while (lx < s->last_lit);
3255 
3256     send_code(s, END_BLOCK, ltree);
3257     s->last_eob_len = ltree[END_BLOCK].Len;
3258 }
3259 
3260 /* ===========================================================================
3261  * Set the data type to ASCII or BINARY, using a crude approximation:
3262  * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
3263  * IN assertion: the fields freq of dyn_ltree are set and the total of all
3264  * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
3265  */
3266 local void set_data_type(s)
3267     deflate_state *s;
3268 {
3269     int n = 0;
3270     unsigned ascii_freq = 0;
3271     unsigned bin_freq = 0;
3272     while (n < 7)        bin_freq += s->dyn_ltree[n++].Freq;
3273     while (n < 128)    ascii_freq += s->dyn_ltree[n++].Freq;
3274     while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
3275     s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
3276 }
3277 
3278 /* ===========================================================================
3279  * Reverse the first len bits of a code, using straightforward code (a faster
3280  * method would use a table)
3281  * IN assertion: 1 <= len <= 15
3282  */
3283 local unsigned bi_reverse(code, len)
3284     unsigned code; /* the value to invert */
3285     int len;       /* its bit length */
3286 {
3287     unsigned res = 0;
3288     do {
3289         res |= code & 1;
3290         code >>= 1, res <<= 1;
3291     } while (--len > 0);
3292     return res >> 1;
3293 }
3294 
3295 /* ===========================================================================
3296  * Flush the bit buffer, keeping at most 7 bits in it.
3297  */
3298 local void bi_flush(s)
3299     deflate_state *s;
3300 {
3301     if (s->bi_valid == 16) {
3302         put_short(s, s->bi_buf);
3303         s->bi_buf = 0;
3304         s->bi_valid = 0;
3305     } else if (s->bi_valid >= 8) {
3306         put_byte(s, (Byte)s->bi_buf);
3307         s->bi_buf >>= 8;
3308         s->bi_valid -= 8;
3309     }
3310 }
3311 
3312 /* ===========================================================================
3313  * Flush the bit buffer and align the output on a byte boundary
3314  */
3315 local void bi_windup(s)
3316     deflate_state *s;
3317 {
3318     if (s->bi_valid > 8) {
3319         put_short(s, s->bi_buf);
3320     } else if (s->bi_valid > 0) {
3321         put_byte(s, (Byte)s->bi_buf);
3322     }
3323     s->bi_buf = 0;
3324     s->bi_valid = 0;
3325 #ifdef DEBUG_ZLIB
3326     s->bits_sent = (s->bits_sent+7) & ~7;
3327 #endif
3328 }
3329 
3330 /* ===========================================================================
3331  * Copy a stored block, storing first the length and its
3332  * one's complement if requested.
3333  */
3334 local void copy_block(s, buf, len, header)
3335     deflate_state *s;
3336     charf    *buf;    /* the input data */
3337     unsigned len;     /* its length */
3338     int      header;  /* true if block header must be written */
3339 {
3340     bi_windup(s);        /* align on byte boundary */
3341     s->last_eob_len = 8; /* enough lookahead for inflate */
3342 
3343     if (header) {
3344         put_short(s, (ush)len);
3345         put_short(s, (ush)~len);
3346 #ifdef DEBUG_ZLIB
3347         s->bits_sent += 2*16;
3348 #endif
3349     }
3350 #ifdef DEBUG_ZLIB
3351     s->bits_sent += (ulg)len<<3;
3352 #endif
3353     /* bundle up the put_byte(s, *buf++) calls */
3354     zmemcpy(&s->pending_buf[s->pending], buf, len);
3355     s->pending += len;
3356 }
3357 /* --- trees.c */
3358 
3359 /* +++ inflate.c */
3360 
3361 /* inflate.c -- zlib interface to inflate modules
3362  * Copyright (C) 1995-2002 Mark Adler
3363  * For conditions of distribution and use, see copyright notice in zlib.h
3364  */
3365 
3366 /* #include "zutil.h" */
3367 
3368 /* +++ infblock.h */
3369 
3370 /* infblock.h -- header to use infblock.c
3371  * Copyright (C) 1995-2002 Mark Adler
3372  * For conditions of distribution and use, see copyright notice in zlib.h
3373  */
3374 
3375 /* WARNING: this file should *not* be used by applications. It is
3376    part of the implementation of the compression library and is
3377    subject to change. Applications should only use zlib.h.
3378  */
3379 
3380 struct inflate_blocks_state;
3381 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3382 
3383 extern inflate_blocks_statef * inflate_blocks_new __P((
3384     z_streamp z,
3385     check_func c,               /* check function */
3386     uInt w));                   /* window size */
3387 
3388 extern int inflate_blocks __P((
3389     inflate_blocks_statef *,
3390     z_streamp ,
3391     int));                      /* initial return code */
3392 
3393 extern void inflate_blocks_reset __P((
3394     inflate_blocks_statef *,
3395     z_streamp ,
3396     uLongf *));                  /* check value on output */
3397 
3398 extern int inflate_blocks_free __P((
3399     inflate_blocks_statef *,
3400     z_streamp));
3401 
3402 extern void inflate_set_dictionary __P((
3403     inflate_blocks_statef *s,
3404     const Bytef *d,  /* dictionary */
3405     uInt  n));       /* dictionary length */
3406 
3407 extern int inflate_blocks_sync_point __P((
3408     inflate_blocks_statef *s));
3409 extern int inflate_addhistory __P((
3410     inflate_blocks_statef *,
3411     z_streamp));
3412 
3413 extern int inflate_packet_flush __P((
3414     inflate_blocks_statef *));
3415 
3416 /* --- infblock.h */
3417 
3418 #ifndef NO_DUMMY_DECL
3419 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3420 #endif
3421 
3422 typedef enum {
3423       METHOD,   /* waiting for method byte */
3424       FLAG,     /* waiting for flag byte */
3425       DICT4,    /* four dictionary check bytes to go */
3426       DICT3,    /* three dictionary check bytes to go */
3427       DICT2,    /* two dictionary check bytes to go */
3428       DICT1,    /* one dictionary check byte to go */
3429       DICT0,    /* waiting for inflateSetDictionary */
3430       BLOCKS,   /* decompressing blocks */
3431       CHECK4,   /* four check bytes to go */
3432       CHECK3,   /* three check bytes to go */
3433       CHECK2,   /* two check bytes to go */
3434       CHECK1,   /* one check byte to go */
3435       DONE,     /* finished check, done */
3436       BAD}      /* got an error--stay here */
3437 inflate_mode;
3438 
3439 /* inflate private state */
3440 struct internal_state {
3441 
3442   /* mode */
3443   inflate_mode  mode;   /* current inflate mode */
3444 
3445   /* mode dependent information */
3446   union {
3447     uInt method;        /* if FLAGS, method byte */
3448     struct {
3449       uLong was;                /* computed check value */
3450       uLong need;               /* stream check value */
3451     } check;            /* if CHECK, check values to compare */
3452     uInt marker;        /* if BAD, inflateSync's marker bytes count */
3453   } sub;        /* submode */
3454 
3455   /* mode independent information */
3456   int  nowrap;          /* flag for no wrapper */
3457   uInt wbits;           /* log2(window size)  (8..15, defaults to 15) */
3458   inflate_blocks_statef
3459     *blocks;            /* current inflate_blocks state */
3460 
3461 };
3462 
3463 
3464 int ZEXPORT inflateReset(z)
3465 z_streamp z;
3466 {
3467   if (z == Z_NULL || z->state == Z_NULL)
3468     return Z_STREAM_ERROR;
3469   z->total_in = z->total_out = 0;
3470   z->msg = Z_NULL;
3471   z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3472   inflate_blocks_reset(z->state->blocks, z, Z_NULL);
3473   Tracev((stderr, "inflate: reset\n"));
3474   return Z_OK;
3475 }
3476 
3477 
3478 int ZEXPORT inflateEnd(z)
3479 z_streamp z;
3480 {
3481   if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3482     return Z_STREAM_ERROR;
3483   if (z->state->blocks != Z_NULL)
3484     inflate_blocks_free(z->state->blocks, z);
3485   ZFREE(z, z->state);
3486   z->state = Z_NULL;
3487   Tracev((stderr, "inflate: end\n"));
3488   return Z_OK;
3489 }
3490 
3491 
3492 int ZEXPORT inflateInit2_(z, w, vers, stream_size)
3493 z_streamp z;
3494 int w;
3495 const char *vers;
3496 int stream_size;
3497 {
3498   if (vers == Z_NULL || vers[0] != ZLIB_VERSION[0] ||
3499       stream_size != sizeof(z_stream))
3500       return Z_VERSION_ERROR;
3501 
3502   /* initialize state */
3503   if (z == Z_NULL)
3504     return Z_STREAM_ERROR;
3505   z->msg = Z_NULL;
3506 #ifndef NO_ZCFUNCS
3507   if (z->zalloc == Z_NULL)
3508   {
3509     z->zalloc = zcalloc;
3510     z->opaque = (voidpf)0;
3511   }
3512   if (z->zfree == Z_NULL) z->zfree = zcfree;
3513 #endif
3514   if ((z->state = (struct internal_state FAR *)
3515        ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3516     return Z_MEM_ERROR;
3517   z->state->blocks = Z_NULL;
3518 
3519   /* handle undocumented nowrap option (no zlib header or check) */
3520   z->state->nowrap = 0;
3521   if (w < 0)
3522   {
3523     w = - w;
3524     z->state->nowrap = 1;
3525   }
3526 
3527   /* set window size */
3528   if (w < 8 || w > 15)
3529   {
3530     inflateEnd(z);
3531     return Z_STREAM_ERROR;
3532   }
3533   z->state->wbits = (uInt)w;
3534 
3535   /* create inflate_blocks state */
3536   if ((z->state->blocks =
3537       inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3538       == Z_NULL)
3539   {
3540     inflateEnd(z);
3541     return Z_MEM_ERROR;
3542   }
3543   Tracev((stderr, "inflate: allocated\n"));
3544 
3545   /* reset state */
3546   inflateReset(z);
3547   return Z_OK;
3548 }
3549 
3550 
3551 #if 0
3552 int ZEXPORT inflateInit_(z, vers, stream_size)
3553 z_streamp z;
3554 const char *vers;
3555 int stream_size;
3556 {
3557   return inflateInit2_(z, DEF_WBITS, vers, stream_size);
3558 }
3559 #endif
3560 
3561 
3562 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3563 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3564 
3565 int ZEXPORT inflate(z, f)
3566 z_streamp z;
3567 int f;
3568 {
3569   int r, r2;
3570   uInt b;
3571 
3572   if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
3573     return Z_STREAM_ERROR;
3574   r2 = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
3575   r = Z_BUF_ERROR;
3576   while (1) switch (z->state->mode)
3577   {
3578     case METHOD:
3579       NEEDBYTE
3580       if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3581       {
3582         z->state->mode = BAD;
3583         z->msg = "unknown compression method";
3584         z->state->sub.marker = 5;       /* can't try inflateSync */
3585         break;
3586       }
3587       if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3588       {
3589         z->state->mode = BAD;
3590         z->msg = "invalid window size";
3591         z->state->sub.marker = 5;       /* can't try inflateSync */
3592         break;
3593       }
3594       z->state->mode = FLAG;
3595     case FLAG:
3596       NEEDBYTE
3597       b = NEXTBYTE;
3598       if (((z->state->sub.method << 8) + b) % 31)
3599       {
3600         z->state->mode = BAD;
3601         z->msg = "incorrect header check";
3602         z->state->sub.marker = 5;       /* can't try inflateSync */
3603         break;
3604       }
3605       Tracev((stderr, "inflate: zlib header ok\n"));
3606       if (!(b & PRESET_DICT))
3607       {
3608         z->state->mode = BLOCKS;
3609         break;
3610       }
3611       z->state->mode = DICT4;
3612     case DICT4:
3613       NEEDBYTE
3614       z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3615       z->state->mode = DICT3;
3616     case DICT3:
3617       NEEDBYTE
3618       z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3619       z->state->mode = DICT2;
3620     case DICT2:
3621       NEEDBYTE
3622       z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3623       z->state->mode = DICT1;
3624     case DICT1:
3625       NEEDBYTE
3626       z->state->sub.check.need += (uLong)NEXTBYTE;
3627       z->adler = z->state->sub.check.need;
3628       z->state->mode = DICT0;
3629       return Z_NEED_DICT;
3630     case DICT0:
3631       z->state->mode = BAD;
3632       z->msg = "need dictionary";
3633       z->state->sub.marker = 0;       /* can try inflateSync */
3634       return Z_STREAM_ERROR;
3635     case BLOCKS:
3636       r = inflate_blocks(z->state->blocks, z, r);
3637       if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3638          r = inflate_packet_flush(z->state->blocks);
3639       if (r == Z_DATA_ERROR)
3640       {
3641         z->state->mode = BAD;
3642         z->state->sub.marker = 0;       /* can try inflateSync */
3643         break;
3644       }
3645       if (r == Z_OK)
3646         r = r2;
3647       if (r != Z_STREAM_END)
3648         return r;
3649       r = r2;
3650       inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3651       if (z->state->nowrap)
3652       {
3653         z->state->mode = DONE;
3654         break;
3655       }
3656       z->state->mode = CHECK4;
3657     case CHECK4:
3658       NEEDBYTE
3659       z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3660       z->state->mode = CHECK3;
3661     case CHECK3:
3662       NEEDBYTE
3663       z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3664       z->state->mode = CHECK2;
3665     case CHECK2:
3666       NEEDBYTE
3667       z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3668       z->state->mode = CHECK1;
3669     case CHECK1:
3670       NEEDBYTE
3671       z->state->sub.check.need += (uLong)NEXTBYTE;
3672 
3673       if (z->state->sub.check.was != z->state->sub.check.need)
3674       {
3675         z->state->mode = BAD;
3676         z->msg = "incorrect data check";
3677         z->state->sub.marker = 5;       /* can't try inflateSync */
3678         break;
3679       }
3680       Tracev((stderr, "inflate: zlib check ok\n"));
3681       z->state->mode = DONE;
3682     case DONE:
3683       return Z_STREAM_END;
3684     case BAD:
3685       return Z_DATA_ERROR;
3686     default:
3687       return Z_STREAM_ERROR;
3688   }
3689  empty:
3690   if (f != Z_PACKET_FLUSH)
3691     return r;
3692   z->state->mode = BAD;
3693   z->msg = "need more for packet flush";
3694   z->state->sub.marker = 0;
3695   return Z_DATA_ERROR;
3696 }
3697 
3698 
3699 #if 0
3700 int ZEXPORT inflateSetDictionary(z, dictionary, dictLength)
3701 z_streamp z;
3702 const Bytef *dictionary;
3703 uInt  dictLength;
3704 {
3705   uInt length = dictLength;
3706 
3707   if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3708     return Z_STREAM_ERROR;
3709 
3710   if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3711   z->adler = 1L;
3712 
3713   if (length >= ((uInt)1<<z->state->wbits))
3714   {
3715     length = (1<<z->state->wbits)-1;
3716     dictionary += dictLength - length;
3717   }
3718   inflate_set_dictionary(z->state->blocks, dictionary, length);
3719   z->state->mode = BLOCKS;
3720   return Z_OK;
3721 }
3722 #endif
3723 
3724 /*
3725  * This subroutine adds the data at next_in/avail_in to the output history
3726  * without performing any output.  The output buffer must be "caught up";
3727  * i.e. no pending output (hence s->read equals s->write), and the state must
3728  * be BLOCKS (i.e. we should be willing to see the start of a series of
3729  * BLOCKS).  On exit, the output will also be caught up, and the checksum
3730  * will have been updated if need be.
3731  */
3732 
3733 int inflateIncomp(z)
3734 z_stream *z;
3735 {
3736     if (z->state->mode != BLOCKS)
3737 	return Z_DATA_ERROR;
3738     return inflate_addhistory(z->state->blocks, z);
3739 }
3740 
3741 #if 0
3742 int ZEXPORT inflateSync(z)
3743 z_streamp z;
3744 {
3745   uInt n;       /* number of bytes to look at */
3746   Bytef *p;     /* pointer to bytes */
3747   uInt m;       /* number of marker bytes found in a row */
3748   uLong r, w;   /* temporaries to save total_in and total_out */
3749 
3750   /* set up */
3751   if (z == Z_NULL || z->state == Z_NULL)
3752     return Z_STREAM_ERROR;
3753   if (z->state->mode != BAD)
3754   {
3755     z->state->mode = BAD;
3756     z->state->sub.marker = 0;
3757   }
3758   if ((n = z->avail_in) == 0)
3759     return Z_BUF_ERROR;
3760   p = z->next_in;
3761   m = z->state->sub.marker;
3762 
3763   /* search */
3764   while (n && m < 4)
3765   {
3766     static const Byte mark[4] = {0, 0, 0xff, 0xff};
3767     if (*p == mark[m])
3768       m++;
3769     else if (*p)
3770       m = 0;
3771     else
3772       m = 4 - m;
3773     p++, n--;
3774   }
3775 
3776   /* restore */
3777   z->total_in += p - z->next_in;
3778   z->next_in = p;
3779   z->avail_in = n;
3780   z->state->sub.marker = m;
3781 
3782   /* return no joy or set up to restart on a new block */
3783   if (m != 4)
3784     return Z_DATA_ERROR;
3785   r = z->total_in;  w = z->total_out;
3786   inflateReset(z);
3787   z->total_in = r;  z->total_out = w;
3788   z->state->mode = BLOCKS;
3789   return Z_OK;
3790 }
3791 #endif
3792 
3793 
3794 /* Returns true if inflate is currently at the end of a block generated
3795  * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
3796  * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
3797  * but removes the length bytes of the resulting empty stored block. When
3798  * decompressing, PPP checks that at the end of input packet, inflate is
3799  * waiting for these length bytes.
3800  */
3801 #if 0
3802 int ZEXPORT inflateSyncPoint(z)
3803 z_streamp z;
3804 {
3805   if (z == Z_NULL || z->state == Z_NULL || z->state->blocks == Z_NULL)
3806     return Z_STREAM_ERROR;
3807   return inflate_blocks_sync_point(z->state->blocks);
3808 }
3809 #endif
3810 #undef NEEDBYTE
3811 #undef NEXTBYTE
3812 /* --- inflate.c */
3813 
3814 /* +++ infblock.c */
3815 
3816 /* infblock.c -- interpret and process block types to last block
3817  * Copyright (C) 1995-2002 Mark Adler
3818  * For conditions of distribution and use, see copyright notice in zlib.h
3819  */
3820 
3821 /* #include "zutil.h" */
3822 /* #include "infblock.h" */
3823 
3824 /* +++ inftrees.h */
3825 
3826 /* inftrees.h -- header to use inftrees.c
3827  * Copyright (C) 1995-2002 Mark Adler
3828  * For conditions of distribution and use, see copyright notice in zlib.h
3829  */
3830 
3831 /* WARNING: this file should *not* be used by applications. It is
3832    part of the implementation of the compression library and is
3833    subject to change. Applications should only use zlib.h.
3834  */
3835 
3836 /* Huffman code lookup table entry--this entry is four bytes for machines
3837    that have 16-bit pointers (e.g. PC's in the small or medium model). */
3838 
3839 typedef struct inflate_huft_s FAR inflate_huft;
3840 
3841 struct inflate_huft_s {
3842   union {
3843     struct {
3844       Byte Exop;        /* number of extra bits or operation */
3845       Byte Bits;        /* number of bits in this code or subcode */
3846     } what;
3847     uInt pad;           /* pad structure to a power of 2 (4 bytes for */
3848   } word;               /*  16-bit, 8 bytes for 32-bit int's) */
3849   uInt base;            /* literal, length base, distance base,
3850                            or table offset */
3851 };
3852 
3853 /* Maximum size of dynamic tree.  The maximum found in a long but non-
3854    exhaustive search was 1004 huft structures (850 for length/literals
3855    and 154 for distances, the latter actually the result of an
3856    exhaustive search).  The actual maximum is not known, but the
3857    value below is more than safe. */
3858 #define MANY 1440
3859 
3860 extern int inflate_trees_bits __P((
3861     uIntf *,                    /* 19 code lengths */
3862     uIntf *,                    /* bits tree desired/actual depth */
3863     inflate_huft * FAR *,       /* bits tree result */
3864     inflate_huft *,             /* space for trees */
3865     z_streamp));                /* for messages */
3866 
3867 extern int inflate_trees_dynamic __P((
3868     uInt,                       /* number of literal/length codes */
3869     uInt,                       /* number of distance codes */
3870     uIntf *,                    /* that many (total) code lengths */
3871     uIntf *,                    /* literal desired/actual bit depth */
3872     uIntf *,                    /* distance desired/actual bit depth */
3873     inflate_huft * FAR *,       /* literal/length tree result */
3874     inflate_huft * FAR *,       /* distance tree result */
3875     inflate_huft *,             /* space for trees */
3876     z_streamp));                /* for messages */
3877 
3878 extern int inflate_trees_fixed __P((
3879     uIntf *,                    /* literal desired/actual bit depth */
3880     uIntf *,                    /* distance desired/actual bit depth */
3881     inflate_huft * FAR *,       /* literal/length tree result */
3882     inflate_huft * FAR *,       /* distance tree result */
3883     z_streamp));                /* for memory allocation */
3884 /* --- inftrees.h */
3885 
3886 /* +++ infcodes.h */
3887 
3888 /* infcodes.h -- header to use infcodes.c
3889  * Copyright (C) 1995-2002 Mark Adler
3890  * For conditions of distribution and use, see copyright notice in zlib.h
3891  */
3892 
3893 /* WARNING: this file should *not* be used by applications. It is
3894    part of the implementation of the compression library and is
3895    subject to change. Applications should only use zlib.h.
3896  */
3897 
3898 struct inflate_codes_state;
3899 typedef struct inflate_codes_state FAR inflate_codes_statef;
3900 
3901 extern inflate_codes_statef *inflate_codes_new __P((
3902     uInt, uInt,
3903     inflate_huft *, inflate_huft *,
3904     z_streamp ));
3905 
3906 extern int inflate_codes __P((
3907     inflate_blocks_statef *,
3908     z_streamp ,
3909     int));
3910 
3911 extern void inflate_codes_free __P((
3912     inflate_codes_statef *,
3913     z_streamp ));
3914 
3915 /* --- infcodes.h */
3916 
3917 /* +++ infutil.h */
3918 
3919 /* infutil.h -- types and macros common to blocks and codes
3920  * Copyright (C) 1995-2002 Mark Adler
3921  * For conditions of distribution and use, see copyright notice in zlib.h
3922  */
3923 
3924 /* WARNING: this file should *not* be used by applications. It is
3925    part of the implementation of the compression library and is
3926    subject to change. Applications should only use zlib.h.
3927  */
3928 
3929 #ifndef _INFUTIL_H
3930 #define _INFUTIL_H
3931 
3932 typedef enum {
3933       TYPE,     /* get type bits (3, including end bit) */
3934       LENS,     /* get lengths for stored */
3935       STORED,   /* processing stored block */
3936       TABLE,    /* get table lengths */
3937       BTREE,    /* get bit lengths tree for a dynamic block */
3938       DTREE,    /* get length, distance trees for a dynamic block */
3939       CODES,    /* processing fixed or dynamic block */
3940       DRY,      /* output remaining window bytes */
3941       DONEB,    /* finished last block, done */
3942       BADB}     /* got a data error--stuck here */
3943 inflate_block_mode;
3944 
3945 /* inflate blocks semi-private state */
3946 struct inflate_blocks_state {
3947 
3948   /* mode */
3949   inflate_block_mode  mode;     /* current inflate_block mode */
3950 
3951   /* mode dependent information */
3952   union {
3953     uInt left;          /* if STORED, bytes left to copy */
3954     struct {
3955       uInt table;               /* table lengths (14 bits) */
3956       uInt index;               /* index into blens (or border) */
3957       uIntf *blens;             /* bit lengths of codes */
3958       uInt bb;                  /* bit length tree depth */
3959       inflate_huft *tb;         /* bit length decoding tree */
3960     } trees;            /* if DTREE, decoding info for trees */
3961     struct {
3962       inflate_codes_statef
3963          *codes;
3964     } decode;           /* if CODES, current state */
3965   } sub;                /* submode */
3966   uInt last;            /* true if this block is the last block */
3967 
3968   /* mode independent information */
3969   uInt bitk;            /* bits in bit buffer */
3970   uLong bitb;           /* bit buffer */
3971   inflate_huft *hufts;  /* single malloc for tree space */
3972   Bytef *window;        /* sliding window */
3973   Bytef *end;           /* one byte after sliding window */
3974   Bytef *read;          /* window read pointer */
3975   Bytef *write;         /* window write pointer */
3976   check_func checkfn;   /* check function */
3977   uLong check;          /* check on output */
3978 
3979 };
3980 
3981 
3982 /* defines for inflate input/output */
3983 /*   update pointers and return */
3984 #define UPDBITS {s->bitb=b;s->bitk=k;}
3985 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3986 #define UPDOUT {s->write=q;}
3987 #define UPDATE {UPDBITS UPDIN UPDOUT}
3988 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3989 /*   get bytes and bits */
3990 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3991 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3992 #define NEXTBYTE (n--,*p++)
3993 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3994 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3995 /*   output bytes */
3996 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3997 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3998 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3999 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
4000 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
4001 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
4002 /*   load local pointers */
4003 #define LOAD {LOADIN LOADOUT}
4004 
4005 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
4006 extern uInt inflate_mask[17];
4007 
4008 /* copy as much as possible from the sliding window to the output area */
4009 extern int inflate_flush __P((
4010     inflate_blocks_statef *,
4011     z_streamp ,
4012     int));
4013 
4014 #ifndef NO_DUMMY_DECL
4015 struct internal_state      {int dummy;}; /* for buggy compilers */
4016 #endif
4017 
4018 #endif
4019 /* --- infutil.h */
4020 
4021 #ifndef NO_DUMMY_DECL
4022 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4023 #endif
4024 
4025 /* simplify the use of the inflate_huft type with some defines */
4026 #define exop word.what.Exop
4027 #define bits word.what.Bits
4028 
4029 /* Table for deflate from PKZIP's appnote.txt. */
4030 local const uInt border[] = { /* Order of the bit length code lengths */
4031         16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
4032 
4033 /*
4034    Notes beyond the 1.93a appnote.txt:
4035 
4036    1. Distance pointers never point before the beginning of the output
4037       stream.
4038    2. Distance pointers can point back across blocks, up to 32k away.
4039    3. There is an implied maximum of 7 bits for the bit length table and
4040       15 bits for the actual data.
4041    4. If only one code exists, then it is encoded using one bit.  (Zero
4042       would be more efficient, but perhaps a little confusing.)  If two
4043       codes exist, they are coded using one bit each (0 and 1).
4044    5. There is no way of sending zero distance codes--a dummy must be
4045       sent if there are none.  (History: a pre 2.0 version of PKZIP would
4046       store blocks with no distance codes, but this was discovered to be
4047       too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow
4048       zero distance codes, which is sent as one code of zero bits in
4049       length.
4050    6. There are up to 286 literal/length codes.  Code 256 represents the
4051       end-of-block.  Note however that the static length tree defines
4052       288 codes just to fill out the Huffman codes.  Codes 286 and 287
4053       cannot be used though, since there is no length base or extra bits
4054       defined for them.  Similarily, there are up to 30 distance codes.
4055       However, static trees define 32 codes (all 5 bits) to fill out the
4056       Huffman codes, but the last two had better not show up in the data.
4057    7. Unzip can check dynamic Huffman blocks for complete code sets.
4058       The exception is that a single code would not be complete (see #4).
4059    8. The five bits following the block type is really the number of
4060       literal codes sent minus 257.
4061    9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
4062       (1+6+6).  Therefore, to output three times the length, you output
4063       three codes (1+1+1), whereas to output four times the same length,
4064       you only need two codes (1+3).  Hmm.
4065   10. In the tree reconstruction algorithm, Code = Code + Increment
4066       only if BitLength(i) is not zero.  (Pretty obvious.)
4067   11. Correction: 4 Bits: # of Bit Length codes - 4     (4 - 19)
4068   12. Note: length code 284 can represent 227-258, but length code 285
4069       really is 258.  The last length deserves its own, short code
4070       since it gets used a lot in very redundant files.  The length
4071       258 is special since 258 - 3 (the min match length) is 255.
4072   13. The literal/length and distance code bit lengths are read as a
4073       single stream of lengths.  It is possible (and advantageous) for
4074       a repeat code (16, 17, or 18) to go across the boundary between
4075       the two sets of lengths.
4076  */
4077 
4078 
4079 void inflate_blocks_reset(s, z, c)
4080 inflate_blocks_statef *s;
4081 z_streamp z;
4082 uLongf *c;
4083 {
4084   if (c != Z_NULL)
4085     *c = s->check;
4086   if (s->mode == BTREE || s->mode == DTREE)
4087     ZFREE(z, s->sub.trees.blens);
4088   if (s->mode == CODES)
4089     inflate_codes_free(s->sub.decode.codes, z);
4090   s->mode = TYPE;
4091   s->bitk = 0;
4092   s->bitb = 0;
4093   s->read = s->write = s->window;
4094   if (s->checkfn != Z_NULL)
4095     z->adler = s->check = (*s->checkfn)(0L, (const Bytef *)Z_NULL, 0);
4096   Tracev((stderr, "inflate:   blocks reset\n"));
4097 }
4098 
4099 
4100 inflate_blocks_statef *inflate_blocks_new(z, c, w)
4101 z_streamp z;
4102 check_func c;
4103 uInt w;
4104 {
4105   inflate_blocks_statef *s;
4106 
4107   if ((s = (inflate_blocks_statef *)ZALLOC
4108        (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
4109     return s;
4110   if ((s->hufts =
4111        (inflate_huft *)ZALLOC(z, sizeof(inflate_huft), MANY)) == Z_NULL)
4112   {
4113     ZFREE(z, s);
4114     return Z_NULL;
4115   }
4116   if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
4117   {
4118     ZFREE(z, s->hufts);
4119     ZFREE(z, s);
4120     return Z_NULL;
4121   }
4122   s->end = s->window + w;
4123   s->checkfn = c;
4124   s->mode = TYPE;
4125   Tracev((stderr, "inflate:   blocks allocated\n"));
4126   inflate_blocks_reset(s, z, Z_NULL);
4127   return s;
4128 }
4129 
4130 
4131 int inflate_blocks(s, z, r)
4132 inflate_blocks_statef *s;
4133 z_streamp z;
4134 int r;
4135 {
4136   uInt t;               /* temporary storage */
4137   uLong b;              /* bit buffer */
4138   uInt k;               /* bits in bit buffer */
4139   Bytef *p;             /* input data pointer */
4140   uInt n;               /* bytes available there */
4141   Bytef *q;             /* output window write pointer */
4142   uInt m;               /* bytes to end of window or read pointer */
4143 
4144   /* copy input/output information to locals (UPDATE macro restores) */
4145   LOAD
4146 
4147   /* process input based on current state */
4148   while (1) switch (s->mode)
4149   {
4150     case TYPE:
4151       NEEDBITS(3)
4152       t = (uInt)b & 7;
4153       s->last = t & 1;
4154       switch (t >> 1)
4155       {
4156         case 0:                         /* stored */
4157           Tracev((stderr, "inflate:     stored block%s\n",
4158                  s->last ? " (last)" : ""));
4159           DUMPBITS(3)
4160           t = k & 7;                    /* go to byte boundary */
4161           DUMPBITS(t)
4162           s->mode = LENS;               /* get length of stored block */
4163           break;
4164         case 1:                         /* fixed */
4165           Tracev((stderr, "inflate:     fixed codes block%s\n",
4166                  s->last ? " (last)" : ""));
4167           {
4168             uInt bl, bd;
4169             inflate_huft *tl, *td;
4170 
4171             inflate_trees_fixed(&bl, &bd, &tl, &td, z);
4172             s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
4173             if (s->sub.decode.codes == Z_NULL)
4174             {
4175               r = Z_MEM_ERROR;
4176               LEAVE
4177             }
4178           }
4179           DUMPBITS(3)
4180           s->mode = CODES;
4181           break;
4182         case 2:                         /* dynamic */
4183           Tracev((stderr, "inflate:     dynamic codes block%s\n",
4184                  s->last ? " (last)" : ""));
4185           DUMPBITS(3)
4186           s->mode = TABLE;
4187           break;
4188         case 3:                         /* illegal */
4189           DUMPBITS(3)
4190           s->mode = BADB;
4191           z->msg = "invalid block type";
4192           r = Z_DATA_ERROR;
4193           LEAVE
4194       }
4195       break;
4196     case LENS:
4197       NEEDBITS(32)
4198       if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
4199       {
4200         s->mode = BADB;
4201         z->msg = "invalid stored block lengths";
4202         r = Z_DATA_ERROR;
4203         LEAVE
4204       }
4205       s->sub.left = (uInt)b & 0xffff;
4206       b = k = 0;                      /* dump bits */
4207       Tracev((stderr, "inflate:       stored length %u\n", s->sub.left));
4208       s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
4209       break;
4210     case STORED:
4211       if (n == 0)
4212         LEAVE
4213       NEEDOUT
4214       t = s->sub.left;
4215       if (t > n) t = n;
4216       if (t > m) t = m;
4217       zmemcpy(q, p, t);
4218       p += t;  n -= t;
4219       q += t;  m -= t;
4220       if ((s->sub.left -= t) != 0)
4221         break;
4222       Tracev((stderr, "inflate:       stored end, %lu total out\n",
4223               z->total_out + (q >= s->read ? q - s->read :
4224               (s->end - s->read) + (q - s->window))));
4225       s->mode = s->last ? DRY : TYPE;
4226       break;
4227     case TABLE:
4228       NEEDBITS(14)
4229       s->sub.trees.table = t = (uInt)b & 0x3fff;
4230 #ifndef PKZIP_BUG_WORKAROUND
4231       if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
4232       {
4233         s->mode = BADB;
4234         z->msg = "too many length or distance symbols";
4235         r = Z_DATA_ERROR;
4236         LEAVE
4237       }
4238 #endif
4239       t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
4240       if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
4241       {
4242         r = Z_MEM_ERROR;
4243         LEAVE
4244       }
4245       DUMPBITS(14)
4246       s->sub.trees.index = 0;
4247       Tracev((stderr, "inflate:       table sizes ok\n"));
4248       s->mode = BTREE;
4249     case BTREE:
4250       while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
4251       {
4252         NEEDBITS(3)
4253         s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
4254         DUMPBITS(3)
4255       }
4256       while (s->sub.trees.index < 19)
4257         s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
4258       s->sub.trees.bb = 7;
4259       t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
4260                              &s->sub.trees.tb, s->hufts, z);
4261       if (t != Z_OK)
4262       {
4263         r = t;
4264         if (r == Z_DATA_ERROR)
4265         {
4266           ZFREE(z, s->sub.trees.blens);
4267           s->mode = BADB;
4268         }
4269         LEAVE
4270       }
4271       s->sub.trees.index = 0;
4272       Tracev((stderr, "inflate:       bits tree ok\n"));
4273       s->mode = DTREE;
4274     case DTREE:
4275       while (t = s->sub.trees.table,
4276              s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
4277       {
4278         inflate_huft *h;
4279         uInt i, j, c;
4280 
4281         t = s->sub.trees.bb;
4282         NEEDBITS(t)
4283         h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
4284         t = h->bits;
4285         c = h->base;
4286         if (c < 16)
4287         {
4288           DUMPBITS(t)
4289           s->sub.trees.blens[s->sub.trees.index++] = c;
4290         }
4291         else /* c == 16..18 */
4292         {
4293           i = c == 18 ? 7 : c - 14;
4294           j = c == 18 ? 11 : 3;
4295           NEEDBITS(t + i)
4296           DUMPBITS(t)
4297           j += (uInt)b & inflate_mask[i];
4298           DUMPBITS(i)
4299           i = s->sub.trees.index;
4300           t = s->sub.trees.table;
4301           if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
4302               (c == 16 && i < 1))
4303           {
4304             ZFREE(z, s->sub.trees.blens);
4305             s->mode = BADB;
4306             z->msg = "invalid bit length repeat";
4307             r = Z_DATA_ERROR;
4308             LEAVE
4309           }
4310           c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
4311           do {
4312             s->sub.trees.blens[i++] = c;
4313           } while (--j);
4314           s->sub.trees.index = i;
4315         }
4316       }
4317       s->sub.trees.tb = Z_NULL;
4318       {
4319         uInt bl, bd;
4320         inflate_huft *tl, *td;
4321         inflate_codes_statef *c;
4322 
4323         bl = 9;         /* must be <= 9 for lookahead assumptions */
4324         bd = 6;         /* must be <= 9 for lookahead assumptions */
4325         t = s->sub.trees.table;
4326         t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
4327                                   s->sub.trees.blens, &bl, &bd, &tl, &td,
4328                                   s->hufts, z);
4329         if (t != Z_OK)
4330         {
4331           if (t == (uInt)Z_DATA_ERROR)
4332           {
4333             ZFREE(z, s->sub.trees.blens);
4334             s->mode = BADB;
4335           }
4336           r = t;
4337           LEAVE
4338         }
4339         Tracev((stderr, "inflate:       trees ok\n"));
4340         if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
4341         {
4342           r = Z_MEM_ERROR;
4343           LEAVE
4344         }
4345         s->sub.decode.codes = c;
4346       }
4347       ZFREE(z, s->sub.trees.blens);
4348       s->mode = CODES;
4349     case CODES:
4350       UPDATE
4351       if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
4352         return inflate_flush(s, z, r);
4353       r = Z_OK;
4354       inflate_codes_free(s->sub.decode.codes, z);
4355       LOAD
4356       Tracev((stderr, "inflate:       codes end, %lu total out\n",
4357               z->total_out + (q >= s->read ? q - s->read :
4358               (s->end - s->read) + (q - s->window))));
4359       if (!s->last)
4360       {
4361         s->mode = TYPE;
4362         break;
4363       }
4364       s->mode = DRY;
4365     case DRY:
4366       FLUSH
4367       if (s->read != s->write)
4368         LEAVE
4369       s->mode = DONEB;
4370     case DONEB:
4371       r = Z_STREAM_END;
4372       LEAVE
4373     case BADB:
4374       r = Z_DATA_ERROR;
4375       LEAVE
4376     default:
4377       r = Z_STREAM_ERROR;
4378       LEAVE
4379   }
4380 }
4381 
4382 
4383 int inflate_blocks_free(s, z)
4384 inflate_blocks_statef *s;
4385 z_streamp z;
4386 {
4387   inflate_blocks_reset(s, z, Z_NULL);
4388   ZFREE(z, s->window);
4389   ZFREE(z, s->hufts);
4390   ZFREE(z, s);
4391   Tracev((stderr, "inflate:   blocks freed\n"));
4392   return Z_OK;
4393 }
4394 
4395 
4396 #if 0
4397 void inflate_set_dictionary(s, d, n)
4398 inflate_blocks_statef *s;
4399 const Bytef *d;
4400 uInt  n;
4401 {
4402   zmemcpy(s->window, d, n);
4403   s->read = s->write = s->window + n;
4404 }
4405 #endif
4406 
4407 /*
4408  * This subroutine adds the data at next_in/avail_in to the output history
4409  * without performing any output.  The output buffer must be "caught up";
4410  * i.e. no pending output (hence s->read equals s->write), and the state must
4411  * be BLOCKS (i.e. we should be willing to see the start of a series of
4412  * BLOCKS).  On exit, the output will also be caught up, and the checksum
4413  * will have been updated if need be.
4414  */
4415 int inflate_addhistory(s, z)
4416 inflate_blocks_statef *s;
4417 z_stream *z;
4418 {
4419     uLong b;              /* bit buffer */  /* NOT USED HERE */
4420     uInt k;               /* bits in bit buffer */ /* NOT USED HERE */
4421     uInt t;               /* temporary storage */
4422     Bytef *p;             /* input data pointer */
4423     uInt n;               /* bytes available there */
4424     Bytef *q;             /* output window write pointer */
4425     uInt m;               /* bytes to end of window or read pointer */
4426 
4427     if (s->read != s->write)
4428 	return Z_STREAM_ERROR;
4429     if (s->mode != TYPE)
4430 	return Z_DATA_ERROR;
4431 
4432     /* we're ready to rock */
4433     LOAD
4434     /* while there is input ready, copy to output buffer, moving
4435      * pointers as needed.
4436      */
4437     while (n) {
4438 	t = n;  /* how many to do */
4439 	/* is there room until end of buffer? */
4440 	if (t > m) t = m;
4441 	/* update check information */
4442 	if (s->checkfn != Z_NULL)
4443 	    s->check = (*s->checkfn)(s->check, q, t);
4444 	zmemcpy(q, p, t);
4445 	q += t;
4446 	p += t;
4447 	n -= t;
4448 	z->total_out += t;
4449 	s->read = q;    /* drag read pointer forward */
4450 /*      WWRAP  */ 	/* expand WWRAP macro by hand to handle s->read */
4451 	if (q == s->end) {
4452 	    s->read = q = s->window;
4453 	    m = WAVAIL;
4454 	}
4455     }
4456     UPDATE
4457     return Z_OK;
4458 }
4459 
4460 
4461 /*
4462  * At the end of a Deflate-compressed PPP packet, we expect to have seen
4463  * a `stored' block type value but not the (zero) length bytes.
4464  */
4465 int inflate_packet_flush(s)
4466     inflate_blocks_statef *s;
4467 {
4468     if (s->mode != LENS)
4469 	return Z_DATA_ERROR;
4470     s->mode = TYPE;
4471     return Z_OK;
4472 }
4473 
4474 /* Returns true if inflate is currently at the end of a block generated
4475  * by Z_SYNC_FLUSH or Z_FULL_FLUSH.
4476  * IN assertion: s != Z_NULL
4477  */
4478 #if 0
4479 int inflate_blocks_sync_point(s)
4480 inflate_blocks_statef *s;
4481 {
4482   return s->mode == LENS;
4483 }
4484 #endif
4485 /* --- infblock.c */
4486 
4487 
4488 /* +++ inftrees.c */
4489 
4490 /* inftrees.c -- generate Huffman trees for efficient decoding
4491  * Copyright (C) 1995-2002 Mark Adler
4492  * For conditions of distribution and use, see copyright notice in zlib.h
4493  */
4494 
4495 /* #include "zutil.h" */
4496 /* #include "inftrees.h" */
4497 
4498 #if !defined(BUILDFIXED) && !defined(STDC)
4499 #  define BUILDFIXED   /* non ANSI compilers may not accept inffixed.h */
4500 #endif
4501 
4502 const char inflate_copyright[] =
4503    " inflate 1.1.4 Copyright 1995-2002 Mark Adler ";
4504 /*
4505   If you use the zlib library in a product, an acknowledgment is welcome
4506   in the documentation of your product. If for some reason you cannot
4507   include such an acknowledgment, I would appreciate that you keep this
4508   copyright string in the executable of your product.
4509  */
4510 
4511 #ifndef NO_DUMMY_DECL
4512 struct internal_state  {int dummy;}; /* for buggy compilers */
4513 #endif
4514 
4515 /* simplify the use of the inflate_huft type with some defines */
4516 #define exop word.what.Exop
4517 #define bits word.what.Bits
4518 
4519 
4520 local int huft_build __P((
4521     uIntf *,            /* code lengths in bits */
4522     uInt,               /* number of codes */
4523     uInt,               /* number of "simple" codes */
4524     const uIntf *,      /* list of base values for non-simple codes */
4525     const uIntf *,      /* list of extra bits for non-simple codes */
4526     inflate_huft * FAR*,/* result: starting table */
4527     uIntf *,            /* maximum lookup bits (returns actual) */
4528     inflate_huft *,     /* space for trees */
4529     uInt *,             /* hufts used in space */
4530     uIntf * ));         /* space for values */
4531 
4532 /* Tables for deflate from PKZIP's appnote.txt. */
4533 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4534         3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4535         35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4536         /* see note #13 above about 258 */
4537 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4538         0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4539         3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4540 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4541         1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4542         257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4543         8193, 12289, 16385, 24577};
4544 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4545         0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4546         7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4547         12, 12, 13, 13};
4548 
4549 /*
4550    Huffman code decoding is performed using a multi-level table lookup.
4551    The fastest way to decode is to simply build a lookup table whose
4552    size is determined by the longest code.  However, the time it takes
4553    to build this table can also be a factor if the data being decoded
4554    is not very long.  The most common codes are necessarily the
4555    shortest codes, so those codes dominate the decoding time, and hence
4556    the speed.  The idea is you can have a shorter table that decodes the
4557    shorter, more probable codes, and then point to subsidiary tables for
4558    the longer codes.  The time it costs to decode the longer codes is
4559    then traded against the time it takes to make longer tables.
4560 
4561    This results of this trade are in the variables lbits and dbits
4562    below.  lbits is the number of bits the first level table for literal/
4563    length codes can decode in one step, and dbits is the same thing for
4564    the distance codes.  Subsequent tables are also less than or equal to
4565    those sizes.  These values may be adjusted either when all of the
4566    codes are shorter than that, in which case the longest code length in
4567    bits is used, or when the shortest code is *longer* than the requested
4568    table size, in which case the length of the shortest code in bits is
4569    used.
4570 
4571    There are two different values for the two tables, since they code a
4572    different number of possibilities each.  The literal/length table
4573    codes 286 possible values, or in a flat code, a little over eight
4574    bits.  The distance table codes 30 possible values, or a little less
4575    than five bits, flat.  The optimum values for speed end up being
4576    about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4577    The optimum values may differ though from machine to machine, and
4578    possibly even between compilers.  Your mileage may vary.
4579  */
4580 
4581 
4582 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4583 #define BMAX 15         /* maximum bit length of any code */
4584 
4585 local int huft_build(b, n, s, d, e, t, m, hp, hn, v)
4586 uIntf *b;               /* code lengths in bits (all assumed <= BMAX) */
4587 uInt n;                 /* number of codes (assumed <= 288) */
4588 uInt s;                 /* number of simple-valued codes (0..s-1) */
4589 const uIntf *d;         /* list of base values for non-simple codes */
4590 const uIntf *e;         /* list of extra bits for non-simple codes */
4591 inflate_huft * FAR *t;  /* result: starting table */
4592 uIntf *m;               /* maximum lookup bits, returns actual */
4593 inflate_huft *hp;       /* space for trees */
4594 uInt *hn;               /* hufts used in space */
4595 uIntf *v;               /* working area: values in order of bit length */
4596 /* Given a list of code lengths and a maximum table size, make a set of
4597    tables to decode that set of codes.  Return Z_OK on success, Z_BUF_ERROR
4598    if the given code set is incomplete (the tables are still built in this
4599    case), or Z_DATA_ERROR if the input is invalid. */
4600 {
4601 
4602   uInt a;                       /* counter for codes of length k */
4603   uInt c[BMAX+1];               /* bit length count table */
4604   uInt f;                       /* i repeats in table every f entries */
4605   int g;                        /* maximum code length */
4606   int h;                        /* table level */
4607   uInt i;                       /* counter, current code */
4608   uInt j;                       /* counter */
4609   int k;                        /* number of bits in current code */
4610   int l;                        /* bits per table (returned in m) */
4611   uInt mask;                    /* (1 << w) - 1, to avoid cc -O bug on HP */
4612   uIntf *p;                      /* pointer into c[], b[], or v[] */
4613   inflate_huft *q;              /* points to current table */
4614   struct inflate_huft_s r;      /* table entry for structure assignment */
4615   inflate_huft *u[BMAX];        /* table stack */
4616   int w;               /* bits before this table == (l * h) */
4617   uInt x[BMAX+1];               /* bit offsets, then code stack */
4618   uIntf *xp;                    /* pointer into x */
4619   int y;                        /* number of dummy codes added */
4620   uInt z;                       /* number of entries in current table */
4621 
4622   r.base = 0;	/* XXX gcc */
4623 
4624   /* Generate counts for each bit length */
4625   p = c;
4626 #define C0 *p++ = 0;
4627 #define C2 C0 C0 C0 C0
4628 #define C4 C2 C2 C2 C2
4629   C4                            /* clear c[]--assume BMAX+1 is 16 */
4630   p = b;  i = n;
4631   do {
4632     c[*p++]++;                  /* assume all entries <= BMAX */
4633   } while (--i);
4634   if (c[0] == n)                /* null input--all zero length codes */
4635   {
4636     *t = (inflate_huft *)Z_NULL;
4637     *m = 0;
4638     return Z_OK;
4639   }
4640 
4641 
4642   /* Find minimum and maximum length, bound *m by those */
4643   l = *m;
4644   for (j = 1; j <= BMAX; j++)
4645     if (c[j])
4646       break;
4647   k = j;                        /* minimum code length */
4648   if ((uInt)l < j)
4649     l = j;
4650   for (i = BMAX; i; i--)
4651     if (c[i])
4652       break;
4653   g = i;                        /* maximum code length */
4654   if ((uInt)l > i)
4655     l = i;
4656   *m = l;
4657 
4658 
4659   /* Adjust last length count to fill out codes, if needed */
4660   for (y = 1 << j; j < i; j++, y <<= 1)
4661     if ((y -= c[j]) < 0)
4662       return Z_DATA_ERROR;
4663   if ((y -= c[i]) < 0)
4664     return Z_DATA_ERROR;
4665   c[i] += y;
4666 
4667 
4668   /* Generate starting offsets into the value table for each length */
4669   x[1] = j = 0;
4670   p = c + 1;  xp = x + 2;
4671   while (--i) {                 /* note that i == g from above */
4672     *xp++ = (j += *p++);
4673   }
4674 
4675 
4676   /* Make a table of values in order of bit lengths */
4677   p = b;  i = 0;
4678   do {
4679     if ((j = *p++) != 0)
4680       v[x[j]++] = i;
4681   } while (++i < n);
4682   n = x[g];                     /* set n to length of v */
4683 
4684 
4685   /* Generate the Huffman codes and for each, make the table entries */
4686   x[0] = i = 0;                 /* first Huffman code is zero */
4687   p = v;                        /* grab values in bit order */
4688   h = -1;                       /* no tables yet--level -1 */
4689   w = -l;                       /* bits decoded == (l * h) */
4690   u[0] = (inflate_huft *)Z_NULL;        /* just to keep compilers happy */
4691   q = (inflate_huft *)Z_NULL;   /* ditto */
4692   z = 0;                        /* ditto */
4693 
4694   /* go through the bit lengths (k already is bits in shortest code) */
4695   for (; k <= g; k++)
4696   {
4697     a = c[k];
4698     while (a--)
4699     {
4700       /* here i is the Huffman code of length k bits for value *p */
4701       /* make tables up to required level */
4702       while (k > w + l)
4703       {
4704         h++;
4705         w += l;                 /* previous table always l bits */
4706 
4707         /* compute minimum size table less than or equal to l bits */
4708         z = g - w;
4709         z = z > (uInt)l ? l : z;        /* table size upper limit */
4710         if ((f = 1 << (j = k - w)) > a + 1)     /* try a k-w bit table */
4711         {                       /* too few codes for k-w bit table */
4712           f -= a + 1;           /* deduct codes from patterns left */
4713           xp = c + k;
4714           if (j < z)
4715             while (++j < z)     /* try smaller tables up to z bits */
4716             {
4717               if ((f <<= 1) <= *++xp)
4718                 break;          /* enough codes to use up j bits */
4719               f -= *xp;         /* else deduct codes from patterns */
4720             }
4721         }
4722         z = 1 << j;             /* table entries for j-bit table */
4723 
4724         /* allocate new table */
4725         if (*hn + z > MANY)     /* (note: doesn't matter for fixed) */
4726           return Z_DATA_ERROR;  /* overflow of MANY */
4727         u[h] = q = hp + *hn;
4728         *hn += z;
4729 
4730         /* connect to last table, if there is one */
4731         if (h)
4732         {
4733           x[h] = i;             /* save pattern for backing up */
4734           r.bits = (Byte)l;     /* bits to dump before this table */
4735           r.exop = (Byte)j;     /* bits in this table */
4736           j = i >> (w - l);
4737           r.base = (uInt)(q - u[h-1] - j);   /* offset to this table */
4738           u[h-1][j] = r;        /* connect to last table */
4739         }
4740         else
4741           *t = q;               /* first table is returned result */
4742       }
4743 
4744       /* set up table entry in r */
4745       r.bits = (Byte)(k - w);
4746       if (p >= v + n)
4747         r.exop = 128 + 64;      /* out of values--invalid code */
4748       else if (*p < s)
4749       {
4750         r.exop = (Byte)(*p < 256 ? 0 : 32 + 64);     /* 256 is end-of-block */
4751         r.base = *p++;          /* simple code is just the value */
4752       }
4753       else
4754       {
4755         r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4756         r.base = d[*p++ - s];
4757       }
4758 
4759       /* fill code-like entries with r */
4760       f = 1 << (k - w);
4761       for (j = i >> w; j < z; j += f)
4762         q[j] = r;
4763 
4764       /* backwards increment the k-bit code i */
4765       for (j = 1 << (k - 1); i & j; j >>= 1)
4766         i ^= j;
4767       i ^= j;
4768 
4769       /* backup over finished tables */
4770       mask = (1 << w) - 1;      /* needed on HP, cc -O bug */
4771       if (h == -1)
4772 	return Z_BUF_ERROR;
4773       while ((i & mask) != x[h])
4774       {
4775         h--;                    /* don't need to update q */
4776         w -= l;
4777         mask = (1 << w) - 1;
4778       }
4779     }
4780   }
4781 
4782 
4783   /* Return Z_BUF_ERROR if we were given an incomplete table */
4784   return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4785 }
4786 
4787 
4788 int inflate_trees_bits(c, bb, tb, hp, z)
4789 uIntf *c;               /* 19 code lengths */
4790 uIntf *bb;              /* bits tree desired/actual depth */
4791 inflate_huft * FAR *tb; /* bits tree result */
4792 inflate_huft *hp;       /* space for trees */
4793 z_streamp z;            /* for messages */
4794 {
4795   int r;
4796   uInt hn = 0;          /* hufts used in space */
4797   uIntf *v;             /* work area for huft_build */
4798 
4799   if ((v = (uIntf*)ZALLOC(z, 19, sizeof(uInt))) == Z_NULL)
4800     return Z_MEM_ERROR;
4801   r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL,
4802                  tb, bb, hp, &hn, v);
4803   if (r == Z_DATA_ERROR)
4804     z->msg = "oversubscribed dynamic bit lengths tree";
4805   else if (r == Z_BUF_ERROR || *bb == 0)
4806   {
4807     z->msg = "incomplete dynamic bit lengths tree";
4808     r = Z_DATA_ERROR;
4809   }
4810   ZFREE(z, v);
4811   return r;
4812 }
4813 
4814 
4815 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, hp, z)
4816 uInt nl;                /* number of literal/length codes */
4817 uInt nd;                /* number of distance codes */
4818 uIntf *c;               /* that many (total) code lengths */
4819 uIntf *bl;              /* literal desired/actual bit depth */
4820 uIntf *bd;              /* distance desired/actual bit depth */
4821 inflate_huft * FAR *tl; /* literal/length tree result */
4822 inflate_huft * FAR *td; /* distance tree result */
4823 inflate_huft *hp;       /* space for trees */
4824 z_streamp z;            /* for messages */
4825 {
4826   int r;
4827   uInt hn = 0;          /* hufts used in space */
4828   uIntf *v;             /* work area for huft_build */
4829 
4830   /* allocate work area */
4831   if ((v = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
4832     return Z_MEM_ERROR;
4833 
4834   /* build literal/length tree */
4835   r = huft_build(c, nl, 257, cplens, cplext, tl, bl, hp, &hn, v);
4836   if (r != Z_OK || *bl == 0)
4837   {
4838     if (r == Z_DATA_ERROR)
4839       z->msg = "oversubscribed literal/length tree";
4840     else if (r != Z_MEM_ERROR)
4841     {
4842       z->msg = "incomplete literal/length tree";
4843       r = Z_DATA_ERROR;
4844     }
4845     ZFREE(z, v);
4846     return r;
4847   }
4848 
4849   /* build distance tree */
4850   r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, hp, &hn, v);
4851   if (r != Z_OK || (*bd == 0 && nl > 257))
4852   {
4853     if (r == Z_DATA_ERROR)
4854       z->msg = "oversubscribed distance tree";
4855     else if (r == Z_BUF_ERROR) {
4856 #ifdef PKZIP_BUG_WORKAROUND
4857       r = Z_OK;
4858     }
4859 #else
4860       z->msg = "incomplete distance tree";
4861       r = Z_DATA_ERROR;
4862     }
4863     else if (r != Z_MEM_ERROR)
4864     {
4865       z->msg = "empty distance tree with lengths";
4866       r = Z_DATA_ERROR;
4867     }
4868     ZFREE(z, v);
4869     return r;
4870 #endif
4871   }
4872 
4873   /* done */
4874   ZFREE(z, v);
4875   return Z_OK;
4876 }
4877 
4878 
4879 /* build fixed tables only once--keep them here */
4880 #ifdef BUILDFIXED
4881 local int fixed_built = 0;
4882 #define FIXEDH 544      /* number of hufts used by fixed tables */
4883 local inflate_huft fixed_mem[FIXEDH];
4884 local uInt fixed_bl;
4885 local uInt fixed_bd;
4886 local inflate_huft *fixed_tl;
4887 local inflate_huft *fixed_td;
4888 #else
4889 
4890 /* +++ inffixed.h */
4891 /* inffixed.h -- table for decoding fixed codes
4892  * Generated automatically by the maketree.c program
4893  */
4894 
4895 /* WARNING: this file should *not* be used by applications. It is
4896    part of the implementation of the compression library and is
4897    subject to change. Applications should only use zlib.h.
4898  */
4899 
4900 local uInt fixed_bl = 9;
4901 local uInt fixed_bd = 5;
4902 local inflate_huft fixed_tl[] = {
4903     {{{96,7}},256}, {{{0,8}},80}, {{{0,8}},16}, {{{84,8}},115},
4904     {{{82,7}},31}, {{{0,8}},112}, {{{0,8}},48}, {{{0,9}},192},
4905     {{{80,7}},10}, {{{0,8}},96}, {{{0,8}},32}, {{{0,9}},160},
4906     {{{0,8}},0}, {{{0,8}},128}, {{{0,8}},64}, {{{0,9}},224},
4907     {{{80,7}},6}, {{{0,8}},88}, {{{0,8}},24}, {{{0,9}},144},
4908     {{{83,7}},59}, {{{0,8}},120}, {{{0,8}},56}, {{{0,9}},208},
4909     {{{81,7}},17}, {{{0,8}},104}, {{{0,8}},40}, {{{0,9}},176},
4910     {{{0,8}},8}, {{{0,8}},136}, {{{0,8}},72}, {{{0,9}},240},
4911     {{{80,7}},4}, {{{0,8}},84}, {{{0,8}},20}, {{{85,8}},227},
4912     {{{83,7}},43}, {{{0,8}},116}, {{{0,8}},52}, {{{0,9}},200},
4913     {{{81,7}},13}, {{{0,8}},100}, {{{0,8}},36}, {{{0,9}},168},
4914     {{{0,8}},4}, {{{0,8}},132}, {{{0,8}},68}, {{{0,9}},232},
4915     {{{80,7}},8}, {{{0,8}},92}, {{{0,8}},28}, {{{0,9}},152},
4916     {{{84,7}},83}, {{{0,8}},124}, {{{0,8}},60}, {{{0,9}},216},
4917     {{{82,7}},23}, {{{0,8}},108}, {{{0,8}},44}, {{{0,9}},184},
4918     {{{0,8}},12}, {{{0,8}},140}, {{{0,8}},76}, {{{0,9}},248},
4919     {{{80,7}},3}, {{{0,8}},82}, {{{0,8}},18}, {{{85,8}},163},
4920     {{{83,7}},35}, {{{0,8}},114}, {{{0,8}},50}, {{{0,9}},196},
4921     {{{81,7}},11}, {{{0,8}},98}, {{{0,8}},34}, {{{0,9}},164},
4922     {{{0,8}},2}, {{{0,8}},130}, {{{0,8}},66}, {{{0,9}},228},
4923     {{{80,7}},7}, {{{0,8}},90}, {{{0,8}},26}, {{{0,9}},148},
4924     {{{84,7}},67}, {{{0,8}},122}, {{{0,8}},58}, {{{0,9}},212},
4925     {{{82,7}},19}, {{{0,8}},106}, {{{0,8}},42}, {{{0,9}},180},
4926     {{{0,8}},10}, {{{0,8}},138}, {{{0,8}},74}, {{{0,9}},244},
4927     {{{80,7}},5}, {{{0,8}},86}, {{{0,8}},22}, {{{192,8}},0},
4928     {{{83,7}},51}, {{{0,8}},118}, {{{0,8}},54}, {{{0,9}},204},
4929     {{{81,7}},15}, {{{0,8}},102}, {{{0,8}},38}, {{{0,9}},172},
4930     {{{0,8}},6}, {{{0,8}},134}, {{{0,8}},70}, {{{0,9}},236},
4931     {{{80,7}},9}, {{{0,8}},94}, {{{0,8}},30}, {{{0,9}},156},
4932     {{{84,7}},99}, {{{0,8}},126}, {{{0,8}},62}, {{{0,9}},220},
4933     {{{82,7}},27}, {{{0,8}},110}, {{{0,8}},46}, {{{0,9}},188},
4934     {{{0,8}},14}, {{{0,8}},142}, {{{0,8}},78}, {{{0,9}},252},
4935     {{{96,7}},256}, {{{0,8}},81}, {{{0,8}},17}, {{{85,8}},131},
4936     {{{82,7}},31}, {{{0,8}},113}, {{{0,8}},49}, {{{0,9}},194},
4937     {{{80,7}},10}, {{{0,8}},97}, {{{0,8}},33}, {{{0,9}},162},
4938     {{{0,8}},1}, {{{0,8}},129}, {{{0,8}},65}, {{{0,9}},226},
4939     {{{80,7}},6}, {{{0,8}},89}, {{{0,8}},25}, {{{0,9}},146},
4940     {{{83,7}},59}, {{{0,8}},121}, {{{0,8}},57}, {{{0,9}},210},
4941     {{{81,7}},17}, {{{0,8}},105}, {{{0,8}},41}, {{{0,9}},178},
4942     {{{0,8}},9}, {{{0,8}},137}, {{{0,8}},73}, {{{0,9}},242},
4943     {{{80,7}},4}, {{{0,8}},85}, {{{0,8}},21}, {{{80,8}},258},
4944     {{{83,7}},43}, {{{0,8}},117}, {{{0,8}},53}, {{{0,9}},202},
4945     {{{81,7}},13}, {{{0,8}},101}, {{{0,8}},37}, {{{0,9}},170},
4946     {{{0,8}},5}, {{{0,8}},133}, {{{0,8}},69}, {{{0,9}},234},
4947     {{{80,7}},8}, {{{0,8}},93}, {{{0,8}},29}, {{{0,9}},154},
4948     {{{84,7}},83}, {{{0,8}},125}, {{{0,8}},61}, {{{0,9}},218},
4949     {{{82,7}},23}, {{{0,8}},109}, {{{0,8}},45}, {{{0,9}},186},
4950     {{{0,8}},13}, {{{0,8}},141}, {{{0,8}},77}, {{{0,9}},250},
4951     {{{80,7}},3}, {{{0,8}},83}, {{{0,8}},19}, {{{85,8}},195},
4952     {{{83,7}},35}, {{{0,8}},115}, {{{0,8}},51}, {{{0,9}},198},
4953     {{{81,7}},11}, {{{0,8}},99}, {{{0,8}},35}, {{{0,9}},166},
4954     {{{0,8}},3}, {{{0,8}},131}, {{{0,8}},67}, {{{0,9}},230},
4955     {{{80,7}},7}, {{{0,8}},91}, {{{0,8}},27}, {{{0,9}},150},
4956     {{{84,7}},67}, {{{0,8}},123}, {{{0,8}},59}, {{{0,9}},214},
4957     {{{82,7}},19}, {{{0,8}},107}, {{{0,8}},43}, {{{0,9}},182},
4958     {{{0,8}},11}, {{{0,8}},139}, {{{0,8}},75}, {{{0,9}},246},
4959     {{{80,7}},5}, {{{0,8}},87}, {{{0,8}},23}, {{{192,8}},0},
4960     {{{83,7}},51}, {{{0,8}},119}, {{{0,8}},55}, {{{0,9}},206},
4961     {{{81,7}},15}, {{{0,8}},103}, {{{0,8}},39}, {{{0,9}},174},
4962     {{{0,8}},7}, {{{0,8}},135}, {{{0,8}},71}, {{{0,9}},238},
4963     {{{80,7}},9}, {{{0,8}},95}, {{{0,8}},31}, {{{0,9}},158},
4964     {{{84,7}},99}, {{{0,8}},127}, {{{0,8}},63}, {{{0,9}},222},
4965     {{{82,7}},27}, {{{0,8}},111}, {{{0,8}},47}, {{{0,9}},190},
4966     {{{0,8}},15}, {{{0,8}},143}, {{{0,8}},79}, {{{0,9}},254},
4967     {{{96,7}},256}, {{{0,8}},80}, {{{0,8}},16}, {{{84,8}},115},
4968     {{{82,7}},31}, {{{0,8}},112}, {{{0,8}},48}, {{{0,9}},193},
4969     {{{80,7}},10}, {{{0,8}},96}, {{{0,8}},32}, {{{0,9}},161},
4970     {{{0,8}},0}, {{{0,8}},128}, {{{0,8}},64}, {{{0,9}},225},
4971     {{{80,7}},6}, {{{0,8}},88}, {{{0,8}},24}, {{{0,9}},145},
4972     {{{83,7}},59}, {{{0,8}},120}, {{{0,8}},56}, {{{0,9}},209},
4973     {{{81,7}},17}, {{{0,8}},104}, {{{0,8}},40}, {{{0,9}},177},
4974     {{{0,8}},8}, {{{0,8}},136}, {{{0,8}},72}, {{{0,9}},241},
4975     {{{80,7}},4}, {{{0,8}},84}, {{{0,8}},20}, {{{85,8}},227},
4976     {{{83,7}},43}, {{{0,8}},116}, {{{0,8}},52}, {{{0,9}},201},
4977     {{{81,7}},13}, {{{0,8}},100}, {{{0,8}},36}, {{{0,9}},169},
4978     {{{0,8}},4}, {{{0,8}},132}, {{{0,8}},68}, {{{0,9}},233},
4979     {{{80,7}},8}, {{{0,8}},92}, {{{0,8}},28}, {{{0,9}},153},
4980     {{{84,7}},83}, {{{0,8}},124}, {{{0,8}},60}, {{{0,9}},217},
4981     {{{82,7}},23}, {{{0,8}},108}, {{{0,8}},44}, {{{0,9}},185},
4982     {{{0,8}},12}, {{{0,8}},140}, {{{0,8}},76}, {{{0,9}},249},
4983     {{{80,7}},3}, {{{0,8}},82}, {{{0,8}},18}, {{{85,8}},163},
4984     {{{83,7}},35}, {{{0,8}},114}, {{{0,8}},50}, {{{0,9}},197},
4985     {{{81,7}},11}, {{{0,8}},98}, {{{0,8}},34}, {{{0,9}},165},
4986     {{{0,8}},2}, {{{0,8}},130}, {{{0,8}},66}, {{{0,9}},229},
4987     {{{80,7}},7}, {{{0,8}},90}, {{{0,8}},26}, {{{0,9}},149},
4988     {{{84,7}},67}, {{{0,8}},122}, {{{0,8}},58}, {{{0,9}},213},
4989     {{{82,7}},19}, {{{0,8}},106}, {{{0,8}},42}, {{{0,9}},181},
4990     {{{0,8}},10}, {{{0,8}},138}, {{{0,8}},74}, {{{0,9}},245},
4991     {{{80,7}},5}, {{{0,8}},86}, {{{0,8}},22}, {{{192,8}},0},
4992     {{{83,7}},51}, {{{0,8}},118}, {{{0,8}},54}, {{{0,9}},205},
4993     {{{81,7}},15}, {{{0,8}},102}, {{{0,8}},38}, {{{0,9}},173},
4994     {{{0,8}},6}, {{{0,8}},134}, {{{0,8}},70}, {{{0,9}},237},
4995     {{{80,7}},9}, {{{0,8}},94}, {{{0,8}},30}, {{{0,9}},157},
4996     {{{84,7}},99}, {{{0,8}},126}, {{{0,8}},62}, {{{0,9}},221},
4997     {{{82,7}},27}, {{{0,8}},110}, {{{0,8}},46}, {{{0,9}},189},
4998     {{{0,8}},14}, {{{0,8}},142}, {{{0,8}},78}, {{{0,9}},253},
4999     {{{96,7}},256}, {{{0,8}},81}, {{{0,8}},17}, {{{85,8}},131},
5000     {{{82,7}},31}, {{{0,8}},113}, {{{0,8}},49}, {{{0,9}},195},
5001     {{{80,7}},10}, {{{0,8}},97}, {{{0,8}},33}, {{{0,9}},163},
5002     {{{0,8}},1}, {{{0,8}},129}, {{{0,8}},65}, {{{0,9}},227},
5003     {{{80,7}},6}, {{{0,8}},89}, {{{0,8}},25}, {{{0,9}},147},
5004     {{{83,7}},59}, {{{0,8}},121}, {{{0,8}},57}, {{{0,9}},211},
5005     {{{81,7}},17}, {{{0,8}},105}, {{{0,8}},41}, {{{0,9}},179},
5006     {{{0,8}},9}, {{{0,8}},137}, {{{0,8}},73}, {{{0,9}},243},
5007     {{{80,7}},4}, {{{0,8}},85}, {{{0,8}},21}, {{{80,8}},258},
5008     {{{83,7}},43}, {{{0,8}},117}, {{{0,8}},53}, {{{0,9}},203},
5009     {{{81,7}},13}, {{{0,8}},101}, {{{0,8}},37}, {{{0,9}},171},
5010     {{{0,8}},5}, {{{0,8}},133}, {{{0,8}},69}, {{{0,9}},235},
5011     {{{80,7}},8}, {{{0,8}},93}, {{{0,8}},29}, {{{0,9}},155},
5012     {{{84,7}},83}, {{{0,8}},125}, {{{0,8}},61}, {{{0,9}},219},
5013     {{{82,7}},23}, {{{0,8}},109}, {{{0,8}},45}, {{{0,9}},187},
5014     {{{0,8}},13}, {{{0,8}},141}, {{{0,8}},77}, {{{0,9}},251},
5015     {{{80,7}},3}, {{{0,8}},83}, {{{0,8}},19}, {{{85,8}},195},
5016     {{{83,7}},35}, {{{0,8}},115}, {{{0,8}},51}, {{{0,9}},199},
5017     {{{81,7}},11}, {{{0,8}},99}, {{{0,8}},35}, {{{0,9}},167},
5018     {{{0,8}},3}, {{{0,8}},131}, {{{0,8}},67}, {{{0,9}},231},
5019     {{{80,7}},7}, {{{0,8}},91}, {{{0,8}},27}, {{{0,9}},151},
5020     {{{84,7}},67}, {{{0,8}},123}, {{{0,8}},59}, {{{0,9}},215},
5021     {{{82,7}},19}, {{{0,8}},107}, {{{0,8}},43}, {{{0,9}},183},
5022     {{{0,8}},11}, {{{0,8}},139}, {{{0,8}},75}, {{{0,9}},247},
5023     {{{80,7}},5}, {{{0,8}},87}, {{{0,8}},23}, {{{192,8}},0},
5024     {{{83,7}},51}, {{{0,8}},119}, {{{0,8}},55}, {{{0,9}},207},
5025     {{{81,7}},15}, {{{0,8}},103}, {{{0,8}},39}, {{{0,9}},175},
5026     {{{0,8}},7}, {{{0,8}},135}, {{{0,8}},71}, {{{0,9}},239},
5027     {{{80,7}},9}, {{{0,8}},95}, {{{0,8}},31}, {{{0,9}},159},
5028     {{{84,7}},99}, {{{0,8}},127}, {{{0,8}},63}, {{{0,9}},223},
5029     {{{82,7}},27}, {{{0,8}},111}, {{{0,8}},47}, {{{0,9}},191},
5030     {{{0,8}},15}, {{{0,8}},143}, {{{0,8}},79}, {{{0,9}},255}
5031   };
5032 local inflate_huft fixed_td[] = {
5033     {{{80,5}},1}, {{{87,5}},257}, {{{83,5}},17}, {{{91,5}},4097},
5034     {{{81,5}},5}, {{{89,5}},1025}, {{{85,5}},65}, {{{93,5}},16385},
5035     {{{80,5}},3}, {{{88,5}},513}, {{{84,5}},33}, {{{92,5}},8193},
5036     {{{82,5}},9}, {{{90,5}},2049}, {{{86,5}},129}, {{{192,5}},24577},
5037     {{{80,5}},2}, {{{87,5}},385}, {{{83,5}},25}, {{{91,5}},6145},
5038     {{{81,5}},7}, {{{89,5}},1537}, {{{85,5}},97}, {{{93,5}},24577},
5039     {{{80,5}},4}, {{{88,5}},769}, {{{84,5}},49}, {{{92,5}},12289},
5040     {{{82,5}},13}, {{{90,5}},3073}, {{{86,5}},193}, {{{192,5}},24577}
5041   };
5042 /* --- inffixed.h */
5043 
5044 #endif
5045 
5046 
5047 int inflate_trees_fixed(
5048 uIntf *bl,               /* literal desired/actual bit depth */
5049 uIntf *bd,               /* distance desired/actual bit depth */
5050 inflate_huft * FAR *tl,  /* literal/length tree result */
5051 inflate_huft * FAR *td,  /* distance tree result */
5052 z_streamp z)    /* for memory allocation */
5053 {
5054 #ifdef BUILDFIXED
5055   /* build fixed tables if not already */
5056   if (!fixed_built)
5057   {
5058     int k;              /* temporary variable */
5059     uInt f = 0;         /* number of hufts used in fixed_mem */
5060     uIntf *c;           /* length list for huft_build */
5061     uIntf *v;           /* work area for huft_build */
5062 
5063     /* allocate memory */
5064     if ((c = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
5065       return Z_MEM_ERROR;
5066     if ((v = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
5067     {
5068       ZFREE(z, c);
5069       return Z_MEM_ERROR;
5070     }
5071 
5072     /* literal table */
5073     for (k = 0; k < 144; k++)
5074       c[k] = 8;
5075     for (; k < 256; k++)
5076       c[k] = 9;
5077     for (; k < 280; k++)
5078       c[k] = 7;
5079     for (; k < 288; k++)
5080       c[k] = 8;
5081     fixed_bl = 9;
5082     huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl,
5083                fixed_mem, &f, v);
5084 
5085     /* distance table */
5086     for (k = 0; k < 30; k++)
5087       c[k] = 5;
5088     fixed_bd = 5;
5089     huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd,
5090                fixed_mem, &f, v);
5091 
5092     /* done */
5093     ZFREE(z, v);
5094     ZFREE(z, c);
5095     fixed_built = 1;
5096   }
5097 #endif
5098   *bl = fixed_bl;
5099   *bd = fixed_bd;
5100   *tl = fixed_tl;
5101   *td = fixed_td;
5102   return Z_OK;
5103 }
5104 /* --- inftrees.c */
5105 
5106 /* +++ infcodes.c */
5107 
5108 /* infcodes.c -- process literals and length/distance pairs
5109  * Copyright (C) 1995-2002 Mark Adler
5110  * For conditions of distribution and use, see copyright notice in zlib.h
5111  */
5112 
5113 /* #include "zutil.h" */
5114 /* #include "inftrees.h" */
5115 /* #include "infblock.h" */
5116 /* #include "infcodes.h" */
5117 /* #include "infutil.h" */
5118 
5119 /* +++ inffast.h */
5120 
5121 /* inffast.h -- header to use inffast.c
5122  * Copyright (C) 1995-2002 Mark Adler
5123  * For conditions of distribution and use, see copyright notice in zlib.h
5124  */
5125 
5126 /* WARNING: this file should *not* be used by applications. It is
5127    part of the implementation of the compression library and is
5128    subject to change. Applications should only use zlib.h.
5129  */
5130 
5131 extern int inflate_fast __P((
5132     uInt,
5133     uInt,
5134     inflate_huft *,
5135     inflate_huft *,
5136     inflate_blocks_statef *,
5137     z_streamp ));
5138 /* --- inffast.h */
5139 
5140 /* simplify the use of the inflate_huft type with some defines */
5141 #define exop word.what.Exop
5142 #define bits word.what.Bits
5143 
5144 typedef enum {        /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
5145       START,    /* x: set up for LEN */
5146       LEN,      /* i: get length/literal/eob next */
5147       LENEXT,   /* i: getting length extra (have base) */
5148       DIST,     /* i: get distance next */
5149       DISTEXT,  /* i: getting distance extra */
5150       COPY,     /* o: copying bytes in window, waiting for space */
5151       LIT,      /* o: got literal, waiting for output space */
5152       WASH,     /* o: got eob, possibly still output waiting */
5153       END,      /* x: got eob and all data flushed */
5154       BADCODE}  /* x: got error */
5155 inflate_codes_mode;
5156 
5157 /* inflate codes private state */
5158 struct inflate_codes_state {
5159 
5160   /* mode */
5161   inflate_codes_mode mode;      /* current inflate_codes mode */
5162 
5163   /* mode dependent information */
5164   uInt len;
5165   union {
5166     struct {
5167       inflate_huft *tree;       /* pointer into tree */
5168       uInt need;                /* bits needed */
5169     } code;             /* if LEN or DIST, where in tree */
5170     uInt lit;           /* if LIT, literal */
5171     struct {
5172       uInt get;                 /* bits to get for extra */
5173       uInt dist;                /* distance back to copy from */
5174     } copy;             /* if EXT or COPY, where and how much */
5175   } sub;                /* submode */
5176 
5177   /* mode independent information */
5178   Byte lbits;           /* ltree bits decoded per branch */
5179   Byte dbits;           /* dtree bits decoder per branch */
5180   inflate_huft *ltree;          /* literal/length/eob tree */
5181   inflate_huft *dtree;          /* distance tree */
5182 
5183 };
5184 
5185 
5186 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
5187 uInt bl, bd;
5188 inflate_huft *tl;
5189 inflate_huft *td; /* need separate declaration for Borland C++ */
5190 z_streamp z;
5191 {
5192   inflate_codes_statef *c;
5193 
5194   if ((c = (inflate_codes_statef *)
5195        ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
5196   {
5197     c->mode = START;
5198     c->lbits = (Byte)bl;
5199     c->dbits = (Byte)bd;
5200     c->ltree = tl;
5201     c->dtree = td;
5202     Tracev((stderr, "inflate:       codes new\n"));
5203   }
5204   return c;
5205 }
5206 
5207 
5208 int inflate_codes(s, z, r)
5209 inflate_blocks_statef *s;
5210 z_streamp z;
5211 int r;
5212 {
5213   uInt j;               /* temporary storage */
5214   inflate_huft *t;      /* temporary pointer */
5215   uInt e;               /* extra bits or operation */
5216   uLong b;              /* bit buffer */
5217   uInt k;               /* bits in bit buffer */
5218   Bytef *p;             /* input data pointer */
5219   uInt n;               /* bytes available there */
5220   Bytef *q;             /* output window write pointer */
5221   uInt m;               /* bytes to end of window or read pointer */
5222   Bytef *f;             /* pointer to copy strings from */
5223   inflate_codes_statef *c = s->sub.decode.codes;  /* codes state */
5224 
5225   /* copy input/output information to locals (UPDATE macro restores) */
5226   LOAD
5227 
5228   /* process input and output based on current state */
5229   while (1) switch (c->mode)
5230   {             /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
5231     case START:         /* x: set up for LEN */
5232 #ifndef SLOW
5233       if (m >= 258 && n >= 10)
5234       {
5235         UPDATE
5236         r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
5237         LOAD
5238         if (r != Z_OK)
5239         {
5240           c->mode = r == Z_STREAM_END ? WASH : BADCODE;
5241           break;
5242         }
5243       }
5244 #endif /* !SLOW */
5245       c->sub.code.need = c->lbits;
5246       c->sub.code.tree = c->ltree;
5247       c->mode = LEN;
5248     case LEN:           /* i: get length/literal/eob next */
5249       j = c->sub.code.need;
5250       NEEDBITS(j)
5251       t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
5252       DUMPBITS(t->bits)
5253       e = (uInt)(t->exop);
5254       if (e == 0)               /* literal */
5255       {
5256         c->sub.lit = t->base;
5257         Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5258                  "inflate:         literal '%c'\n" :
5259                  "inflate:         literal 0x%02x\n", t->base));
5260         c->mode = LIT;
5261         break;
5262       }
5263       if (e & 16)               /* length */
5264       {
5265         c->sub.copy.get = e & 15;
5266         c->len = t->base;
5267         c->mode = LENEXT;
5268         break;
5269       }
5270       if ((e & 64) == 0)        /* next table */
5271       {
5272         c->sub.code.need = e;
5273         c->sub.code.tree = t + t->base;
5274         break;
5275       }
5276       if (e & 32)               /* end of block */
5277       {
5278         Tracevv((stderr, "inflate:         end of block\n"));
5279         c->mode = WASH;
5280         break;
5281       }
5282       c->mode = BADCODE;        /* invalid code */
5283       z->msg = "invalid literal/length code";
5284       r = Z_DATA_ERROR;
5285       LEAVE
5286     case LENEXT:        /* i: getting length extra (have base) */
5287       j = c->sub.copy.get;
5288       NEEDBITS(j)
5289       c->len += (uInt)b & inflate_mask[j];
5290       DUMPBITS(j)
5291       c->sub.code.need = c->dbits;
5292       c->sub.code.tree = c->dtree;
5293       Tracevv((stderr, "inflate:         length %u\n", c->len));
5294       c->mode = DIST;
5295     case DIST:          /* i: get distance next */
5296       j = c->sub.code.need;
5297       NEEDBITS(j)
5298       t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
5299       DUMPBITS(t->bits)
5300       e = (uInt)(t->exop);
5301       if (e & 16)               /* distance */
5302       {
5303         c->sub.copy.get = e & 15;
5304         c->sub.copy.dist = t->base;
5305         c->mode = DISTEXT;
5306         break;
5307       }
5308       if ((e & 64) == 0)        /* next table */
5309       {
5310         c->sub.code.need = e;
5311         c->sub.code.tree = t + t->base;
5312         break;
5313       }
5314       c->mode = BADCODE;        /* invalid code */
5315       z->msg = "invalid distance code";
5316       r = Z_DATA_ERROR;
5317       LEAVE
5318     case DISTEXT:       /* i: getting distance extra */
5319       j = c->sub.copy.get;
5320       NEEDBITS(j)
5321       c->sub.copy.dist += (uInt)b & inflate_mask[j];
5322       DUMPBITS(j)
5323       Tracevv((stderr, "inflate:         distance %u\n", c->sub.copy.dist));
5324       c->mode = COPY;
5325     case COPY:          /* o: copying bytes in window, waiting for space */
5326       f = q - c->sub.copy.dist;
5327       while (f < s->window)             /* modulo window size-"while" instead */
5328         f += s->end - s->window;        /* of "if" handles invalid distances */
5329       while (c->len)
5330       {
5331         NEEDOUT
5332         OUTBYTE(*f++)
5333         if (f == s->end)
5334           f = s->window;
5335         c->len--;
5336       }
5337       c->mode = START;
5338       break;
5339     case LIT:           /* o: got literal, waiting for output space */
5340       NEEDOUT
5341       OUTBYTE(c->sub.lit)
5342       c->mode = START;
5343       break;
5344     case WASH:          /* o: got eob, possibly more output */
5345       if (k > 7)        /* return unused byte, if any */
5346       {
5347         Assert(k < 16, "inflate_codes grabbed too many bytes")
5348         k -= 8;
5349         n++;
5350         p--;            /* can always return one */
5351       }
5352       FLUSH
5353       if (s->read != s->write)
5354         LEAVE
5355       c->mode = END;
5356     case END:
5357       r = Z_STREAM_END;
5358       LEAVE
5359     case BADCODE:       /* x: got error */
5360       r = Z_DATA_ERROR;
5361       LEAVE
5362     default:
5363       r = Z_STREAM_ERROR;
5364       LEAVE
5365   }
5366 #ifdef NEED_DUMMY_RETURN
5367   return Z_STREAM_ERROR;  /* Some dumb compilers complain without this */
5368 #endif
5369 }
5370 
5371 
5372 void inflate_codes_free(c, z)
5373 inflate_codes_statef *c;
5374 z_streamp z;
5375 {
5376   ZFREE(z, c);
5377   Tracev((stderr, "inflate:       codes free\n"));
5378 }
5379 /* --- infcodes.c */
5380 
5381 /* +++ infutil.c */
5382 
5383 /* inflate_util.c -- data and routines common to blocks and codes
5384  * Copyright (C) 1995-2002 Mark Adler
5385  * For conditions of distribution and use, see copyright notice in zlib.h
5386  */
5387 
5388 /* #include "zutil.h" */
5389 /* #include "infblock.h" */
5390 /* #include "inftrees.h" */
5391 /* #include "infcodes.h" */
5392 /* #include "infutil.h" */
5393 
5394 #ifndef NO_DUMMY_DECL
5395 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
5396 #endif
5397 
5398 /* And'ing with mask[n] masks the lower n bits */
5399 uInt inflate_mask[17] = {
5400     0x0000,
5401     0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
5402     0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
5403 };
5404 
5405 
5406 /* copy as much as possible from the sliding window to the output area */
5407 int inflate_flush(s, z, r)
5408 inflate_blocks_statef *s;
5409 z_streamp z;
5410 int r;
5411 {
5412   uInt n;
5413   Bytef *p;
5414   Bytef *q;
5415 
5416   /* local copies of source and destination pointers */
5417   p = z->next_out;
5418   q = s->read;
5419 
5420   /* compute number of bytes to copy as far as end of window */
5421   n = (uInt)((q <= s->write ? s->write : s->end) - q);
5422   if (n > z->avail_out) n = z->avail_out;
5423   if (n && r == Z_BUF_ERROR) r = Z_OK;
5424 
5425   /* update counters */
5426   z->avail_out -= n;
5427   z->total_out += n;
5428 
5429   /* update check information */
5430   if (s->checkfn != Z_NULL)
5431     z->adler = s->check = (*s->checkfn)(s->check, q, n);
5432 
5433   /* copy as far as end of window */
5434   if (p != Z_NULL) {
5435     zmemcpy(p, q, n);
5436     p += n;
5437   }
5438   q += n;
5439 
5440   /* see if more to copy at beginning of window */
5441   if (q == s->end)
5442   {
5443     /* wrap pointers */
5444     q = s->window;
5445     if (s->write == s->end)
5446       s->write = s->window;
5447 
5448     /* compute bytes to copy */
5449     n = (uInt)(s->write - q);
5450     if (n > z->avail_out) n = z->avail_out;
5451     if (n && r == Z_BUF_ERROR) r = Z_OK;
5452 
5453     /* update counters */
5454     z->avail_out -= n;
5455     z->total_out += n;
5456 
5457     /* update check information */
5458     if (s->checkfn != Z_NULL)
5459       z->adler = s->check = (*s->checkfn)(s->check, q, n);
5460 
5461     /* copy */
5462     if (p != NULL) {
5463       zmemcpy(p, q, n);
5464       p += n;
5465     }
5466     q += n;
5467   }
5468 
5469   /* update pointers */
5470   z->next_out = p;
5471   s->read = q;
5472 
5473   /* done */
5474   return r;
5475 }
5476 /* --- infutil.c */
5477 
5478 /* +++ inffast.c */
5479 
5480 /* inffast.c -- process literals and length/distance pairs fast
5481  * Copyright (C) 1995-2002 Mark Adler
5482  * For conditions of distribution and use, see copyright notice in zlib.h
5483  */
5484 
5485 /* #include "zutil.h" */
5486 /* #include "inftrees.h" */
5487 /* #include "infblock.h" */
5488 /* #include "infcodes.h" */
5489 /* #include "infutil.h" */
5490 /* #include "inffast.h" */
5491 
5492 #ifndef NO_DUMMY_DECL
5493 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
5494 #endif
5495 
5496 /* simplify the use of the inflate_huft type with some defines */
5497 #define exop word.what.Exop
5498 #define bits word.what.Bits
5499 
5500 /* macros for bit input with no checking and for returning unused bytes */
5501 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
5502 #define UNGRAB {c=z->avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;}
5503 
5504 /* Called with number of bytes left to write in window at least 258
5505    (the maximum string length) and number of input bytes available
5506    at least ten.  The ten bytes are six bytes for the longest length/
5507    distance pair plus four bytes for overloading the bit buffer. */
5508 
5509 int inflate_fast(bl, bd, tl, td, s, z)
5510 uInt bl, bd;
5511 inflate_huft *tl;
5512 inflate_huft *td; /* need separate declaration for Borland C++ */
5513 inflate_blocks_statef *s;
5514 z_streamp z;
5515 {
5516   inflate_huft *t;      /* temporary pointer */
5517   uInt e;               /* extra bits or operation */
5518   uLong b;              /* bit buffer */
5519   uInt k;               /* bits in bit buffer */
5520   Bytef *p;             /* input data pointer */
5521   uInt n;               /* bytes available there */
5522   Bytef *q;             /* output window write pointer */
5523   uInt m;               /* bytes to end of window or read pointer */
5524   uInt ml;              /* mask for literal/length tree */
5525   uInt md;              /* mask for distance tree */
5526   uInt c;               /* bytes to copy */
5527   uInt d;               /* distance back to copy from */
5528   Bytef *r;             /* copy source pointer */
5529 
5530   /* load input, output, bit values */
5531   LOAD
5532 
5533   /* initialize masks */
5534   ml = inflate_mask[bl];
5535   md = inflate_mask[bd];
5536 
5537   /* do until not enough input or output space for fast loop */
5538   do {                          /* assume called with m >= 258 && n >= 10 */
5539     /* get literal/length code */
5540     GRABBITS(20)                /* max bits for literal/length code */
5541     if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5542     {
5543       DUMPBITS(t->bits)
5544       Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5545                 "inflate:         * literal '%c'\n" :
5546                 "inflate:         * literal 0x%02x\n", t->base));
5547       *q++ = (Byte)t->base;
5548       m--;
5549       continue;
5550     }
5551     do {
5552       DUMPBITS(t->bits)
5553       if (e & 16)
5554       {
5555         /* get extra bits for length */
5556         e &= 15;
5557         c = t->base + ((uInt)b & inflate_mask[e]);
5558         DUMPBITS(e)
5559         Tracevv((stderr, "inflate:         * length %u\n", c));
5560 
5561         /* decode distance base of block to copy */
5562         GRABBITS(15);           /* max bits for distance code */
5563         e = (t = td + ((uInt)b & md))->exop;
5564         do {
5565           DUMPBITS(t->bits)
5566           if (e & 16)
5567           {
5568             /* get extra bits to add to distance base */
5569             e &= 15;
5570             GRABBITS(e)         /* get extra bits (up to 13) */
5571             d = t->base + ((uInt)b & inflate_mask[e]);
5572             DUMPBITS(e)
5573             Tracevv((stderr, "inflate:         * distance %u\n", d));
5574 
5575             /* do the copy */
5576             m -= c;
5577             r = q - d;
5578             if (r < s->window)                  /* wrap if needed */
5579             {
5580               do {
5581                 r += s->end - s->window;        /* force pointer in window */
5582               } while (r < s->window);          /* covers invalid distances */
5583               e = s->end - r;
5584               if (c > e)
5585               {
5586                 c -= e;                         /* wrapped copy */
5587                 do {
5588                     *q++ = *r++;
5589                 } while (--e);
5590                 r = s->window;
5591                 do {
5592                     *q++ = *r++;
5593                 } while (--c);
5594               }
5595               else                              /* normal copy */
5596               {
5597                 *q++ = *r++;  c--;
5598                 *q++ = *r++;  c--;
5599                 do {
5600                     *q++ = *r++;
5601                 } while (--c);
5602               }
5603             }
5604             else                                /* normal copy */
5605             {
5606               *q++ = *r++;  c--;
5607               *q++ = *r++;  c--;
5608               do {
5609                 *q++ = *r++;
5610               } while (--c);
5611             }
5612             break;
5613           }
5614           else if ((e & 64) == 0)
5615           {
5616             t += t->base;
5617             e = (t += ((uInt)b & inflate_mask[e]))->exop;
5618           }
5619           else
5620           {
5621             z->msg = "invalid distance code";
5622             UNGRAB
5623             UPDATE
5624             return Z_DATA_ERROR;
5625           }
5626         } while (1);
5627         break;
5628       }
5629       if ((e & 64) == 0)
5630       {
5631         t += t->base;
5632         if ((e = (t += ((uInt)b & inflate_mask[e]))->exop) == 0)
5633         {
5634           DUMPBITS(t->bits)
5635           Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5636                     "inflate:         * literal '%c'\n" :
5637                     "inflate:         * literal 0x%02x\n", t->base));
5638           *q++ = (Byte)t->base;
5639           m--;
5640           break;
5641         }
5642       }
5643       else if (e & 32)
5644       {
5645         Tracevv((stderr, "inflate:         * end of block\n"));
5646         UNGRAB
5647         UPDATE
5648         return Z_STREAM_END;
5649       }
5650       else
5651       {
5652         z->msg = "invalid literal/length code";
5653         UNGRAB
5654         UPDATE
5655         return Z_DATA_ERROR;
5656       }
5657     } while (1);
5658   } while (m >= 258 && n >= 10);
5659 
5660   /* not enough input or output--restore pointers and return */
5661   UNGRAB
5662   UPDATE
5663   return Z_OK;
5664 }
5665 /* --- inffast.c */
5666 
5667 /* +++ zutil.c */
5668 
5669 /* zutil.c -- target dependent utility functions for the compression library
5670  * Copyright (C) 1995-2002 Jean-loup Gailly.
5671  * For conditions of distribution and use, see copyright notice in zlib.h
5672  */
5673 
5674 /* @(#) Id */
5675 
5676 #ifdef DEBUG_ZLIB
5677 #include <stdio.h>
5678 #endif
5679 
5680 /* #include "zutil.h" */
5681 
5682 #ifndef NO_DUMMY_DECL
5683 struct internal_state      {int dummy;}; /* for buggy compilers */
5684 #endif
5685 
5686 #ifndef STDC
5687 extern void exit __P((int));
5688 #endif
5689 
5690 const char *z_errmsg[10] = {
5691 "need dictionary",     /* Z_NEED_DICT       2  */
5692 "stream end",          /* Z_STREAM_END      1  */
5693 "",                    /* Z_OK              0  */
5694 "file error",          /* Z_ERRNO         (-1) */
5695 "stream error",        /* Z_STREAM_ERROR  (-2) */
5696 "data error",          /* Z_DATA_ERROR    (-3) */
5697 "insufficient memory", /* Z_MEM_ERROR     (-4) */
5698 "buffer error",        /* Z_BUF_ERROR     (-5) */
5699 "incompatible version",/* Z_VERSION_ERROR (-6) */
5700 ""};
5701 
5702 
5703 #if 0
5704 const char * ZEXPORT zlibVersion()
5705 {
5706     return ZLIB_VERSION;
5707 }
5708 #endif
5709 
5710 #ifdef DEBUG_ZLIB
5711 
5712 #  ifndef verbose
5713 #    define verbose 0
5714 #  endif
5715 int z_verbose = verbose;
5716 
5717 void z_error (m)
5718     char *m;
5719 {
5720     fprintf(stderr, "%s\n", m);
5721     exit(1);
5722 }
5723 #endif
5724 
5725 /* exported to allow conversion of error code to string for compress() and
5726  * uncompress()
5727  */
5728 #if 0
5729 const char * ZEXPORT zError(err)
5730     int err;
5731 {
5732     return ERR_MSG(err);
5733 }
5734 #endif
5735 
5736 
5737 #ifndef HAVE_MEMCPY
5738 
5739 void zmemcpy(dest, source, len)
5740     Bytef* dest;
5741     const Bytef* source;
5742     uInt  len;
5743 {
5744     if (len == 0) return;
5745     do {
5746         *dest++ = *source++; /* ??? to be unrolled */
5747     } while (--len != 0);
5748 }
5749 
5750 int zmemcmp(s1, s2, len)
5751     const Bytef* s1;
5752     const Bytef* s2;
5753     uInt  len;
5754 {
5755     uInt j;
5756 
5757     for (j = 0; j < len; j++) {
5758         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5759     }
5760     return 0;
5761 }
5762 
5763 void zmemzero(dest, len)
5764     Bytef* dest;
5765     uInt  len;
5766 {
5767     if (len == 0) return;
5768     do {
5769         *dest++ = 0;  /* ??? to be unrolled */
5770     } while (--len != 0);
5771 }
5772 #endif
5773 
5774 #ifdef __TURBOC__
5775 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5776 /* Small and medium model in Turbo C are for now limited to near allocation
5777  * with reduced MAX_WBITS and MAX_MEM_LEVEL
5778  */
5779 #  define MY_ZCALLOC
5780 
5781 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5782  * and farmalloc(64K) returns a pointer with an offset of 8, so we
5783  * must fix the pointer. Warning: the pointer must be put back to its
5784  * original form in order to free it, use zcfree().
5785  */
5786 
5787 #define MAX_PTR 10
5788 /* 10*64K = 640K */
5789 
5790 local int next_ptr = 0;
5791 
5792 typedef struct ptr_table_s {
5793     voidpf org_ptr;
5794     voidpf new_ptr;
5795 } ptr_table;
5796 
5797 local ptr_table table[MAX_PTR];
5798 /* This table is used to remember the original form of pointers
5799  * to large buffers (64K). Such pointers are normalized with a zero offset.
5800  * Since MSDOS is not a preemptive multitasking OS, this table is not
5801  * protected from concurrent access. This hack doesn't work anyway on
5802  * a protected system like OS/2. Use Microsoft C instead.
5803  */
5804 
5805 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5806 {
5807     voidpf buf = opaque; /* just to make some compilers happy */
5808     ulg bsize = (ulg)items*size;
5809 
5810     /* If we allocate less than 65520 bytes, we assume that farmalloc
5811      * will return a usable pointer which doesn't have to be normalized.
5812      */
5813     if (bsize < 65520L) {
5814         buf = farmalloc(bsize);
5815         if (*(ush*)&buf != 0) return buf;
5816     } else {
5817         buf = farmalloc(bsize + 16L);
5818     }
5819     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5820     table[next_ptr].org_ptr = buf;
5821 
5822     /* Normalize the pointer to seg:0 */
5823     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5824     *(ush*)&buf = 0;
5825     table[next_ptr++].new_ptr = buf;
5826     return buf;
5827 }
5828 
5829 void  zcfree (voidpf opaque, voidpf ptr)
5830 {
5831     int n;
5832     if (*(ush*)&ptr != 0) { /* object < 64K */
5833         farfree(ptr);
5834         return;
5835     }
5836     /* Find the original pointer */
5837     for (n = 0; n < next_ptr; n++) {
5838         if (ptr != table[n].new_ptr) continue;
5839 
5840         farfree(table[n].org_ptr);
5841         while (++n < next_ptr) {
5842             table[n-1] = table[n];
5843         }
5844         next_ptr--;
5845         return;
5846     }
5847     ptr = opaque; /* just to make some compilers happy */
5848     Assert(0, "zcfree: ptr not found");
5849 }
5850 #endif
5851 #endif /* __TURBOC__ */
5852 
5853 
5854 #if defined(M_I86) && !defined(__32BIT__)
5855 /* Microsoft C in 16-bit mode */
5856 
5857 #  define MY_ZCALLOC
5858 
5859 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
5860 #  define _halloc  halloc
5861 #  define _hfree   hfree
5862 #endif
5863 
5864 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5865 {
5866     if (opaque) opaque = 0; /* to make compiler happy */
5867     return _halloc((long)items, size);
5868 }
5869 
5870 void  zcfree (voidpf opaque, voidpf ptr)
5871 {
5872     if (opaque) opaque = 0; /* to make compiler happy */
5873     _hfree(ptr);
5874 }
5875 
5876 #endif /* MSC */
5877 
5878 
5879 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5880 
5881 #ifndef STDC
5882 extern voidp  calloc __P((uInt items, uInt size));
5883 extern void   free   __P((voidpf ptr));
5884 #endif
5885 
5886 voidpf zcalloc (opaque, items, size)
5887     voidpf opaque;
5888     unsigned items;
5889     unsigned size;
5890 {
5891     if (opaque) items += size - size; /* make compiler happy */
5892     return (voidpf)calloc(items, size);
5893 }
5894 
5895 void  zcfree (opaque, ptr)
5896     voidpf opaque;
5897     voidpf ptr;
5898 {
5899     free(ptr);
5900     if (opaque) return; /* make compiler happy */
5901 }
5902 
5903 #endif /* MY_ZCALLOC */
5904 /* --- zutil.c */
5905 
5906 /* +++ adler32.c */
5907 /* adler32.c -- compute the Adler-32 checksum of a data stream
5908  * Copyright (C) 1995-2002 Mark Adler
5909  * For conditions of distribution and use, see copyright notice in zlib.h
5910  */
5911 
5912 /* @(#) $Id: zlib.c,v 1.30 2008/05/05 13:41:30 ad Exp $ */
5913 
5914 /* #include "zlib.h" */
5915 
5916 #define BASE 65521L /* largest prime smaller than 65536 */
5917 #define NMAX 5552
5918 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5919 
5920 #define DO1(buf,i)  {s1 += buf[i]; s2 += s1;}
5921 #define DO2(buf,i)  DO1(buf,i); DO1(buf,i+1);
5922 #define DO4(buf,i)  DO2(buf,i); DO2(buf,i+2);
5923 #define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);
5924 #define DO16(buf)   DO8(buf,0); DO8(buf,8);
5925 
5926 /* ========================================================================= */
5927 uLong ZEXPORT adler32(adler, buf, len)
5928     uLong adler;
5929     const Bytef *buf;
5930     uInt len;
5931 {
5932     unsigned long s1 = adler & 0xffff;
5933     unsigned long s2 = (adler >> 16) & 0xffff;
5934     int k;
5935 
5936     if (buf == Z_NULL) return 1L;
5937 
5938     while (len > 0) {
5939         k = len < NMAX ? len : NMAX;
5940         len -= k;
5941         while (k >= 16) {
5942             DO16(buf);
5943 	    buf += 16;
5944             k -= 16;
5945         }
5946         if (k != 0) do {
5947             s1 += *buf++;
5948 	    s2 += s1;
5949         } while (--k);
5950         s1 %= BASE;
5951         s2 %= BASE;
5952     }
5953     return (s2 << 16) | s1;
5954 }
5955 /* --- adler32.c */
5956 
5957