xref: /netbsd-src/sys/net/zlib.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: zlib.c,v 1.23 2006/01/14 18:58:05 christos 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 1.23 2006/01/14 18:58:05 christos 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 1.23 2006/01/14 18:58:05 christos 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 1.23 2006/01/14 18:58:05 christos 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 
92 #ifndef local
93 #  define local static
94 #endif
95 /* compile with -Dlocal if your debugger can't find static symbols */
96 
97 typedef unsigned char  uch;
98 typedef uch FAR uchf;
99 typedef unsigned short ush;
100 typedef ush FAR ushf;
101 typedef unsigned long  ulg;
102 
103 extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
104 /* (size given to avoid silly warnings with Visual C++) */
105 
106 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
107 
108 #define ERR_RETURN(strm,err) \
109   return (strm->msg = ERR_MSG(err), (err))
110 /* To be used only when the state is known to be valid */
111 
112         /* common constants */
113 
114 #ifndef DEF_WBITS
115 #  define DEF_WBITS MAX_WBITS
116 #endif
117 /* default windowBits for decompression. MAX_WBITS is for compression only */
118 
119 #if MAX_MEM_LEVEL >= 8
120 #  define DEF_MEM_LEVEL 8
121 #else
122 #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
123 #endif
124 /* default memLevel */
125 
126 #define STORED_BLOCK 0
127 #define STATIC_TREES 1
128 #define DYN_TREES    2
129 /* The three kinds of block type */
130 
131 #define MIN_MATCH  3
132 #define MAX_MATCH  258
133 /* The minimum and maximum match lengths */
134 
135 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
136 
137         /* target dependencies */
138 
139 #ifdef MSDOS
140 #  define OS_CODE  0x00
141 #  if defined(__TURBOC__) || defined(__BORLANDC__)
142 #    if(__STDC__ == 1) && (defined(__LARGE__) || defined(__COMPACT__))
143        /* Allow compilation with ANSI keywords only enabled */
144        void _Cdecl farfree( void *block );
145        void *_Cdecl farmalloc( unsigned long nbytes );
146 #    else
147 #     include <alloc.h>
148 #    endif
149 #  else /* MSC or DJGPP */
150 #    include <malloc.h>
151 #  endif
152 #endif
153 
154 #ifdef OS2
155 #  define OS_CODE  0x06
156 #endif
157 
158 #ifdef WIN32 /* Window 95 & Windows NT */
159 #  define OS_CODE  0x0b
160 #endif
161 
162 #if defined(VAXC) || defined(VMS)
163 #  define OS_CODE  0x02
164 #  define F_OPEN(name, mode) \
165      fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
166 #endif
167 
168 #ifdef AMIGA
169 #  define OS_CODE  0x01
170 #endif
171 
172 #if defined(ATARI) || defined(atarist)
173 #  define OS_CODE  0x05
174 #endif
175 
176 #if defined(MACOS) || defined(TARGET_OS_MAC)
177 #  define OS_CODE  0x07
178 #  if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
179 #    include <unix.h> /* for fdopen */
180 #  else
181 #    ifndef fdopen
182 #      define fdopen(fd,mode) NULL /* No fdopen() */
183 #    endif
184 #  endif
185 #endif
186 
187 #ifdef __50SERIES /* Prime/PRIMOS */
188 #  define OS_CODE  0x0F
189 #endif
190 
191 #ifdef TOPS20
192 #  define OS_CODE  0x0a
193 #endif
194 
195 #if defined(_BEOS_) || defined(RISCOS)
196 #  define fdopen(fd,mode) NULL /* No fdopen() */
197 #endif
198 
199 #if (defined(_MSC_VER) && (_MSC_VER > 600))
200 #  define fdopen(fd,type)  _fdopen(fd,type)
201 #endif
202 
203 
204         /* Common defaults */
205 
206 #ifndef OS_CODE
207 #  define OS_CODE  0x03  /* assume Unix */
208 #endif
209 
210 #ifndef F_OPEN
211 #  define F_OPEN(name, mode) fopen((name), (mode))
212 #endif
213 
214          /* functions */
215 
216 #ifdef HAVE_STRERROR
217    extern char *strerror __P((int));
218 #  define zstrerror(errnum) strerror(errnum)
219 #else
220 #  define zstrerror(errnum) ""
221 #endif
222 
223 #if defined(pyr)
224 #  define NO_MEMCPY
225 #endif
226 #if defined(SMALL_MEDIUM) && !defined(_MSC_VER) && !defined(__SC__)
227  /* Use our own functions for small and medium model with MSC <= 5.0.
228   * You may have to use the same strategy for Borland C (untested).
229   * The __SC__ check is for Symantec.
230   */
231 #  define NO_MEMCPY
232 #endif
233 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
234 #  define HAVE_MEMCPY
235 #endif
236 #ifdef HAVE_MEMCPY
237 #  ifdef SMALL_MEDIUM /* MSDOS small or medium model */
238 #    define zmemcpy _fmemcpy
239 #    define zmemcmp _fmemcmp
240 #    define zmemzero(dest, len) _fmemset(dest, 0, len)
241 #  else
242 #    define zmemcpy memcpy
243 #    define zmemcmp memcmp
244 #    define zmemzero(dest, len) memset(dest, 0, len)
245 #  endif
246 #else
247    extern void zmemcpy  __P((Bytef* dest, const Bytef* source, uInt len));
248    extern int  zmemcmp  __P((const Bytef* s1, const Bytef* s2, uInt len));
249    extern void zmemzero __P((Bytef* dest, uInt len));
250 #endif
251 
252 /* Diagnostic functions */
253 #if defined(DEBUG_ZLIB) && !defined(_KERNEL) && !defined(_STANDALONE)
254 #  include <stdio.h>
255    extern int z_verbose;
256    extern void z_error    __P((char *m));
257 #  define Assert(cond,msg) {if(!(cond)) z_error(msg);}
258 #  define Trace(x) {if (z_verbose>=0) fprintf x ;}
259 #  define Tracev(x) {if (z_verbose>0) fprintf x ;}
260 #  define Tracevv(x) {if (z_verbose>1) fprintf x ;}
261 #  define Tracec(c,x) {if (z_verbose>0 && (c)) fprintf x ;}
262 #  define Tracecv(c,x) {if (z_verbose>1 && (c)) fprintf x ;}
263 #else
264 #  define Assert(cond,msg)
265 #  define Trace(x)
266 #  define Tracev(x)
267 #  define Tracevv(x)
268 #  define Tracec(c,x)
269 #  define Tracecv(c,x)
270 #endif
271 
272 
273 typedef uLong (ZEXPORT *check_func) __P((uLong check, const Bytef *buf,
274 				       uInt len));
275 voidpf zcalloc __P((voidpf opaque, unsigned items, unsigned size));
276 void   zcfree  __P((voidpf opaque, voidpf ptr));
277 
278 #define ZALLOC(strm, items, size) \
279            (*((strm)->zalloc))((strm)->opaque, (items), (size))
280 #define ZFREE(strm, addr)  (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
281 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
282 
283 #endif /* _Z_UTIL_H */
284 /* --- zutil.h */
285 
286 /* +++ deflate.h */
287 
288 /* deflate.h -- internal compression state
289  * Copyright (C) 1995-2002 Jean-loup Gailly
290  * For conditions of distribution and use, see copyright notice in zlib.h
291  */
292 
293 /* WARNING: this file should *not* be used by applications. It is
294    part of the implementation of the compression library and is
295    subject to change. Applications should only use zlib.h.
296  */
297 
298 /* @(#) $Id: zlib.c,v 1.23 2006/01/14 18:58:05 christos Exp $ */
299 
300 #ifndef _DEFLATE_H
301 #define _DEFLATE_H
302 
303 /* #include "zutil.h" */
304 
305 /* ===========================================================================
306  * Internal compression state.
307  */
308 
309 #define LENGTH_CODES 29
310 /* number of length codes, not counting the special END_BLOCK code */
311 
312 #define LITERALS  256
313 /* number of literal bytes 0..255 */
314 
315 #define L_CODES (LITERALS+1+LENGTH_CODES)
316 /* number of Literal or Length codes, including the END_BLOCK code */
317 
318 #define D_CODES   30
319 /* number of distance codes */
320 
321 #define BL_CODES  19
322 /* number of codes used to transfer the bit lengths */
323 
324 #define HEAP_SIZE (2*L_CODES+1)
325 /* maximum heap size */
326 
327 #define MAX_BITS 15
328 /* All codes must not exceed MAX_BITS bits */
329 
330 #define INIT_STATE    42
331 #define BUSY_STATE   113
332 #define FINISH_STATE 666
333 /* Stream status */
334 
335 
336 /* Data structure describing a single value and its code string. */
337 typedef struct ct_data_s {
338     union {
339         ush  freq;       /* frequency count */
340         ush  code;       /* bit string */
341     } fc;
342     union {
343         ush  dad;        /* father node in Huffman tree */
344         ush  len;        /* length of bit string */
345     } dl;
346 } FAR ct_data;
347 
348 #define Freq fc.freq
349 #define Code fc.code
350 #define Dad  dl.dad
351 #define Len  dl.len
352 
353 typedef struct static_tree_desc_s  static_tree_desc;
354 
355 typedef struct tree_desc_s {
356     ct_data *dyn_tree;           /* the dynamic tree */
357     int     max_code;            /* largest code with non zero frequency */
358     static_tree_desc *stat_desc; /* the corresponding static tree */
359 } FAR tree_desc;
360 
361 typedef ush Pos;
362 typedef Pos FAR Posf;
363 typedef unsigned IPos;
364 
365 /* A Pos is an index in the character window. We use short instead of int to
366  * save space in the various tables. IPos is used only for parameter passing.
367  */
368 
369 typedef struct deflate_state {
370     z_streamp strm;      /* pointer back to this zlib stream */
371     int   status;        /* as the name implies */
372     Bytef *pending_buf;  /* output still pending */
373     ulg   pending_buf_size; /* size of pending_buf */
374     Bytef *pending_out;  /* next pending byte to output to the stream */
375     int   pending;       /* nb of bytes in the pending buffer */
376     int   noheader;      /* suppress zlib header and adler32 */
377     Byte  data_type;     /* UNKNOWN, BINARY or ASCII */
378     Byte  method;        /* STORED (for zip only) or DEFLATED */
379     int   last_flush;    /* value of flush param for previous deflate call */
380 
381                 /* used by deflate.c: */
382 
383     uInt  w_size;        /* LZ77 window size (32K by default) */
384     uInt  w_bits;        /* log2(w_size)  (8..16) */
385     uInt  w_mask;        /* w_size - 1 */
386 
387     Bytef *window;
388     /* Sliding window. Input bytes are read into the second half of the window,
389      * and move to the first half later to keep a dictionary of at least wSize
390      * bytes. With this organization, matches are limited to a distance of
391      * wSize-MAX_MATCH bytes, but this ensures that IO is always
392      * performed with a length multiple of the block size. Also, it limits
393      * the window size to 64K, which is quite useful on MSDOS.
394      * To do: use the user input buffer as sliding window.
395      */
396 
397     ulg window_size;
398     /* Actual size of window: 2*wSize, except when the user input buffer
399      * is directly used as sliding window.
400      */
401 
402     Posf *prev;
403     /* Link to older string with same hash index. To limit the size of this
404      * array to 64K, this link is maintained only for the last 32K strings.
405      * An index in this array is thus a window index modulo 32K.
406      */
407 
408     Posf *head; /* Heads of the hash chains or NIL. */
409 
410     uInt  ins_h;          /* hash index of string to be inserted */
411     uInt  hash_size;      /* number of elements in hash table */
412     uInt  hash_bits;      /* log2(hash_size) */
413     uInt  hash_mask;      /* hash_size-1 */
414 
415     uInt  hash_shift;
416     /* Number of bits by which ins_h must be shifted at each input
417      * step. It must be such that after MIN_MATCH steps, the oldest
418      * byte no longer takes part in the hash key, that is:
419      *   hash_shift * MIN_MATCH >= hash_bits
420      */
421 
422     long block_start;
423     /* Window position at the beginning of the current output block. Gets
424      * negative when the window is moved backwards.
425      */
426 
427     uInt match_length;           /* length of best match */
428     IPos prev_match;             /* previous match */
429     int match_available;         /* set if previous match exists */
430     uInt strstart;               /* start of string to insert */
431     uInt match_start;            /* start of matching string */
432     uInt lookahead;              /* number of valid bytes ahead in window */
433 
434     uInt prev_length;
435     /* Length of the best match at previous step. Matches not greater than this
436      * are discarded. This is used in the lazy match evaluation.
437      */
438 
439     uInt max_chain_length;
440     /* To speed up deflation, hash chains are never searched beyond this
441      * length.  A higher limit improves compression ratio but degrades the
442      * speed.
443      */
444 
445     uInt max_lazy_match;
446     /* Attempt to find a better match only when the current match is strictly
447      * smaller than this value. This mechanism is used only for compression
448      * levels >= 4.
449      */
450 #   define max_insert_length  max_lazy_match
451     /* Insert new strings in the hash table only if the match length is not
452      * greater than this length. This saves time but degrades compression.
453      * max_insert_length is used only for compression levels <= 3.
454      */
455 
456     int level;    /* compression level (1..9) */
457     int strategy; /* favor or force Huffman coding*/
458 
459     uInt good_match;
460     /* Use a faster search when the previous match is longer than this */
461 
462     int nice_match; /* Stop searching when current match exceeds this */
463 
464                 /* used by trees.c: */
465     /* Didn't use ct_data typedef below to supress compiler warning */
466     struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
467     struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
468     struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
469 
470     struct tree_desc_s l_desc;               /* desc. for literal tree */
471     struct tree_desc_s d_desc;               /* desc. for distance tree */
472     struct tree_desc_s bl_desc;              /* desc. for bit length tree */
473 
474     ush bl_count[MAX_BITS+1];
475     /* number of codes at each bit length for an optimal tree */
476 
477     int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
478     int heap_len;               /* number of elements in the heap */
479     int heap_max;               /* element of largest frequency */
480     /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
481      * The same heap array is used to build all trees.
482      */
483 
484     uch depth[2*L_CODES+1];
485     /* Depth of each subtree used as tie breaker for trees of equal frequency
486      */
487 
488     uchf *l_buf;          /* buffer for literals or lengths */
489 
490     uInt  lit_bufsize;
491     /* Size of match buffer for literals/lengths.  There are 4 reasons for
492      * limiting lit_bufsize to 64K:
493      *   - frequencies can be kept in 16 bit counters
494      *   - if compression is not successful for the first block, all input
495      *     data is still in the window so we can still emit a stored block even
496      *     when input comes from standard input.  (This can also be done for
497      *     all blocks if lit_bufsize is not greater than 32K.)
498      *   - if compression is not successful for a file smaller than 64K, we can
499      *     even emit a stored file instead of a stored block (saving 5 bytes).
500      *     This is applicable only for zip (not gzip or zlib).
501      *   - creating new Huffman trees less frequently may not provide fast
502      *     adaptation to changes in the input data statistics. (Take for
503      *     example a binary file with poorly compressible code followed by
504      *     a highly compressible string table.) Smaller buffer sizes give
505      *     fast adaptation but have of course the overhead of transmitting
506      *     trees more frequently.
507      *   - I can't count above 4
508      */
509 
510     uInt last_lit;      /* running index in l_buf */
511 
512     ushf *d_buf;
513     /* Buffer for distances. To simplify the code, d_buf and l_buf have
514      * the same number of elements. To use different lengths, an extra flag
515      * array would be necessary.
516      */
517 
518     ulg opt_len;        /* bit length of current block with optimal trees */
519     ulg static_len;     /* bit length of current block with static trees */
520     uInt matches;       /* number of string matches in current block */
521     int last_eob_len;   /* bit length of EOB code for last block */
522 
523 #ifdef DEBUG_ZLIB
524     ulg compressed_len; /* total bit length of compressed file mod 2^32 */
525     ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
526 #endif
527 
528     ush bi_buf;
529     /* Output buffer. bits are inserted starting at the bottom (least
530      * significant bits).
531      */
532     int bi_valid;
533     /* Number of valid bits in bi_buf.  All bits above the last valid bit
534      * are always zero.
535      */
536 
537 } FAR deflate_state;
538 
539 /* Output a byte on the stream.
540  * IN assertion: there is enough room in pending_buf.
541  */
542 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
543 
544 
545 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
546 /* Minimum amount of lookahead, except at the end of the input file.
547  * See deflate.c for comments about the MIN_MATCH+1.
548  */
549 
550 #define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
551 /* In order to simplify the code, particularly on 16 bit machines, match
552  * distances are limited to MAX_DIST instead of WSIZE.
553  */
554 
555         /* in trees.c */
556 void _tr_init         __P((deflate_state *s));
557 int  _tr_tally        __P((deflate_state *s, unsigned dist, unsigned lc));
558 void _tr_flush_block  __P((deflate_state *s, charf *buf, ulg stored_len,
559 			  int eof));
560 void _tr_align        __P((deflate_state *s));
561 void _tr_stored_block __P((deflate_state *s, charf *buf, ulg stored_len,
562                           int eof));
563 void _tr_stored_type_only __P((deflate_state *));
564 
565 #define d_code(dist) \
566    ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
567 /* Mapping from a distance to a distance code. dist is the distance - 1 and
568  * must not have side effects. _dist_code[256] and _dist_code[257] are never
569  * used.
570  */
571 
572 #ifndef DEBUG_ZLIB
573 /* Inline versions of _tr_tally for speed: */
574 
575 #if defined(GEN_TREES_H) || !defined(STDC)
576   extern uch _length_code[];
577   extern uch _dist_code[];
578 #else
579   extern const uch _length_code[];
580   extern const uch _dist_code[];
581 #endif
582 
583 # define _tr_tally_lit(s, c, flush) \
584   { uch cc = (c); \
585     s->d_buf[s->last_lit] = 0; \
586     s->l_buf[s->last_lit++] = cc; \
587     s->dyn_ltree[cc].Freq++; \
588     flush = (s->last_lit == s->lit_bufsize-1); \
589    }
590 # define _tr_tally_dist(s, distance, length, flush) \
591   { uch len = (length); \
592     ush dist = (distance); \
593     s->d_buf[s->last_lit] = dist; \
594     s->l_buf[s->last_lit++] = len; \
595     dist--; \
596     s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
597     s->dyn_dtree[d_code(dist)].Freq++; \
598     flush = (s->last_lit == s->lit_bufsize-1); \
599   }
600 #else
601 # define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
602 # define _tr_tally_dist(s, distance, length, flush) \
603               flush = _tr_tally(s, distance, length)
604 #endif
605 
606 #endif
607 /* --- deflate.h */
608 
609 /* +++ deflate.c */
610 
611 /* deflate.c -- compress data using the deflation algorithm
612  * Copyright (C) 1995-2002 Jean-loup Gailly.
613  * For conditions of distribution and use, see copyright notice in zlib.h
614  */
615 
616 /*
617  *  ALGORITHM
618  *
619  *      The "deflation" process depends on being able to identify portions
620  *      of the input text which are identical to earlier input (within a
621  *      sliding window trailing behind the input currently being processed).
622  *
623  *      The most straightforward technique turns out to be the fastest for
624  *      most input files: try all possible matches and select the longest.
625  *      The key feature of this algorithm is that insertions into the string
626  *      dictionary are very simple and thus fast, and deletions are avoided
627  *      completely. Insertions are performed at each input character, whereas
628  *      string matches are performed only when the previous match ends. So it
629  *      is preferable to spend more time in matches to allow very fast string
630  *      insertions and avoid deletions. The matching algorithm for small
631  *      strings is inspired from that of Rabin & Karp. A brute force approach
632  *      is used to find longer strings when a small match has been found.
633  *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
634  *      (by Leonid Broukhis).
635  *         A previous version of this file used a more sophisticated algorithm
636  *      (by Fiala and Greene) which is guaranteed to run in linear amortized
637  *      time, but has a larger average cost, uses more memory and is patented.
638  *      However the F&G algorithm may be faster for some highly redundant
639  *      files if the parameter max_chain_length (described below) is too large.
640  *
641  *  ACKNOWLEDGEMENTS
642  *
643  *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
644  *      I found it in 'freeze' written by Leonid Broukhis.
645  *      Thanks to many people for bug reports and testing.
646  *
647  *  REFERENCES
648  *
649  *      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
650  *      Available in ftp://ds.internic.net/rfc/rfc1951.txt
651  *
652  *      A description of the Rabin and Karp algorithm is given in the book
653  *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
654  *
655  *      Fiala,E.R., and Greene,D.H.
656  *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
657  *
658  */
659 
660 /* @(#) $Id: zlib.c,v 1.23 2006/01/14 18:58:05 christos Exp $ */
661 
662 /* #include "deflate.h" */
663 
664 const char deflate_copyright[] =
665    " deflate 1.1.4 Copyright 1995-2002 Jean-loup Gailly ";
666 /*
667   If you use the zlib library in a product, an acknowledgment is welcome
668   in the documentation of your product. If for some reason you cannot
669   include such an acknowledgment, I would appreciate that you keep this
670   copyright string in the executable of your product.
671  */
672 
673 /* ===========================================================================
674  *  Function prototypes.
675  */
676 typedef enum {
677     need_more,      /* block not completed, need more input or more output */
678     block_done,     /* block flush performed */
679     finish_started, /* finish started, need only more output at next deflate */
680     finish_done     /* finish done, accept no more input or output */
681 } block_state;
682 
683 typedef block_state (*compress_func) __P((deflate_state *s, int flush));
684 /* Compression function. Returns the block state after the call. */
685 
686 local void fill_window    __P((deflate_state *s));
687 local block_state deflate_stored __P((deflate_state *s, int flush));
688 local block_state deflate_fast   __P((deflate_state *s, int flush));
689 local block_state deflate_slow   __P((deflate_state *s, int flush));
690 local void lm_init        __P((deflate_state *s));
691 local void putShortMSB    __P((deflate_state *s, uInt b));
692 local void flush_pending  __P((z_streamp strm));
693 local int read_buf        __P((z_streamp strm, Bytef *buf, unsigned size));
694 #ifdef ASMV
695       void match_init __P((void)); /* asm code initialization */
696       uInt longest_match  __P((deflate_state *s, IPos cur_match));
697 #else
698 local uInt longest_match  __P((deflate_state *s, IPos cur_match));
699 #endif
700 
701 #ifdef DEBUG_ZLIB
702 local  void check_match __P((deflate_state *s, IPos start, IPos match,
703                             int length));
704 #endif
705 
706 /* ===========================================================================
707  * Local data
708  */
709 
710 #define NIL 0
711 /* Tail of hash chains */
712 
713 #ifndef TOO_FAR
714 #  define TOO_FAR 4096
715 #endif
716 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
717 
718 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
719 /* Minimum amount of lookahead, except at the end of the input file.
720  * See deflate.c for comments about the MIN_MATCH+1.
721  */
722 
723 /* Values for max_lazy_match, good_match and max_chain_length, depending on
724  * the desired pack level (0..9). The values given below have been tuned to
725  * exclude worst case performance for pathological files. Better values may be
726  * found for specific files.
727  */
728 typedef struct config_s {
729    ush good_length; /* reduce lazy search above this match length */
730    ush max_lazy;    /* do not perform lazy search above this match length */
731    ush nice_length; /* quit search above this match length */
732    ush max_chain;
733    compress_func func;
734 } config;
735 
736 local const config configuration_table[10] = {
737 /*      good lazy nice chain */
738 /* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
739 /* 1 */ {4,    4,  8,    4, deflate_fast}, /* maximum speed, no lazy matches */
740 /* 2 */ {4,    5, 16,    8, deflate_fast},
741 /* 3 */ {4,    6, 32,   32, deflate_fast},
742 
743 /* 4 */ {4,    4, 16,   16, deflate_slow},  /* lazy matches */
744 /* 5 */ {8,   16, 32,   32, deflate_slow},
745 /* 6 */ {8,   16, 128, 128, deflate_slow},
746 /* 7 */ {8,   32, 128, 256, deflate_slow},
747 /* 8 */ {32, 128, 258, 1024, deflate_slow},
748 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
749 
750 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
751  * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
752  * meaning.
753  */
754 
755 #define EQUAL 0
756 /* result of memcmp for equal strings */
757 
758 #ifndef NO_DUMMY_DECL
759 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
760 #endif
761 
762 /* ===========================================================================
763  * Update a hash value with the given input byte
764  * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
765  *    input characters, so that a running hash key can be computed from the
766  *    previous key instead of complete recalculation each time.
767  */
768 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
769 
770 
771 /* ===========================================================================
772  * Insert string str in the dictionary and set match_head to the previous head
773  * of the hash chain (the most recent string with same hash key). Return
774  * the previous length of the hash chain.
775  * If this file is compiled with -DFASTEST, the compression level is forced
776  * to 1, and no hash chains are maintained.
777  * IN  assertion: all calls to to INSERT_STRING are made with consecutive
778  *    input characters and the first MIN_MATCH bytes of str are valid
779  *    (except for the last MIN_MATCH-1 bytes of the input file).
780  */
781 #ifdef FASTEST
782 #define INSERT_STRING(s, str, match_head) \
783    (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
784     match_head = s->head[s->ins_h], \
785     s->head[s->ins_h] = (Pos)(str))
786 #else
787 #define INSERT_STRING(s, str, match_head) \
788    (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
789     s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
790     s->head[s->ins_h] = (Pos)(str))
791 #endif
792 
793 /* ===========================================================================
794  * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
795  * prev[] will be initialized on the fly.
796  */
797 #define CLEAR_HASH(s) \
798     s->head[s->hash_size-1] = NIL; \
799     zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
800 
801 /* ========================================================================= */
802 #if 0
803 int ZEXPORT deflateInit_(strm, level, version, stream_size)
804     z_streamp strm;
805     int level;
806     const char *version;
807     int stream_size;
808 {
809     return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
810 			 Z_DEFAULT_STRATEGY, version, stream_size);
811     /* To do: ignore strm->next_in if we use it as window */
812 }
813 #endif
814 
815 /* ========================================================================= */
816 int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
817 		  vers, stream_size)
818     z_streamp strm;
819     int  level;
820     int  method;
821     int  windowBits;
822     int  memLevel;
823     int  strategy;
824     const char *vers;
825     int stream_size;
826 {
827     deflate_state *s;
828     int noheader = 0;
829     static const char* my_version = ZLIB_VERSION;
830 
831     ushf *overlay;
832     /* We overlay pending_buf and d_buf+l_buf. This works since the average
833      * output size for (length,distance) codes is <= 24 bits.
834      */
835 
836     if (vers == Z_NULL || vers[0] != my_version[0] ||
837         stream_size != sizeof(z_stream)) {
838 	return Z_VERSION_ERROR;
839     }
840     if (strm == Z_NULL) return Z_STREAM_ERROR;
841 
842     strm->msg = Z_NULL;
843 #ifndef NO_ZCFUNCS
844     if (strm->zalloc == Z_NULL) {
845 	strm->zalloc = zcalloc;
846 	strm->opaque = (voidpf)0;
847     }
848     if (strm->zfree == Z_NULL) strm->zfree = zcfree;
849 #endif
850 
851     if (level == Z_DEFAULT_COMPRESSION) level = 6;
852 #ifdef FASTEST
853     level = 1;
854 #endif
855 
856     if (windowBits < 0) { /* undocumented feature: suppress zlib header */
857         noheader = 1;
858         windowBits = -windowBits;
859     }
860     if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
861         windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
862 	strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
863         return Z_STREAM_ERROR;
864     }
865     s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
866     if (s == Z_NULL) return Z_MEM_ERROR;
867     strm->state = (struct internal_state FAR *)s;
868     s->strm = strm;
869 
870     s->noheader = noheader;
871     s->w_bits = windowBits;
872     s->w_size = 1 << s->w_bits;
873     s->w_mask = s->w_size - 1;
874 
875     s->hash_bits = memLevel + 7;
876     s->hash_size = 1 << s->hash_bits;
877     s->hash_mask = s->hash_size - 1;
878     s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
879 
880     s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
881     s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
882     s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
883 
884     s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
885 
886     overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
887     s->pending_buf = (uchf *) overlay;
888     s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
889 
890     if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
891         s->pending_buf == Z_NULL) {
892         strm->msg = ERR_MSG(Z_MEM_ERROR);
893 	s->status = INIT_STATE;
894         deflateEnd (strm);
895         return Z_MEM_ERROR;
896     }
897     s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
898     s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
899 
900     s->level = level;
901     s->strategy = strategy;
902     s->method = (Byte)method;
903 
904     return deflateReset(strm);
905 }
906 
907 /* ========================================================================= */
908 #if 0
909 int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
910     z_streamp strm;
911     const Bytef *dictionary;
912     uInt  dictLength;
913 {
914     deflate_state *s;
915     uInt length = dictLength;
916     uInt n;
917     IPos hash_head = 0;
918 
919     if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
920         return Z_STREAM_ERROR;
921 
922     s = (deflate_state *)strm->state;
923     if (s->status != INIT_STATE) return Z_STREAM_ERROR;
924 
925     strm->adler = adler32(strm->adler, dictionary, dictLength);
926 
927     if (length < MIN_MATCH) return Z_OK;
928     if (length > MAX_DIST(s)) {
929 	length = MAX_DIST(s);
930 #ifndef USE_DICT_HEAD
931 	dictionary += dictLength - length; /* use the tail of the dictionary */
932 #endif
933     }
934     zmemcpy(s->window, dictionary, length);
935     s->strstart = length;
936     s->block_start = (long)length;
937 
938     /* Insert all strings in the hash table (except for the last two bytes).
939      * s->lookahead stays null, so s->ins_h will be recomputed at the next
940      * call of fill_window.
941      */
942     s->ins_h = s->window[0];
943     UPDATE_HASH(s, s->ins_h, s->window[1]);
944     for (n = 0; n <= length - MIN_MATCH; n++) {
945 	INSERT_STRING(s, n, hash_head);
946     }
947     if (hash_head) hash_head = 0;  /* to make compiler happy */
948     return Z_OK;
949 }
950 #endif
951 
952 /* ========================================================================= */
953 int ZEXPORT deflateReset (strm)
954     z_streamp strm;
955 {
956     deflate_state *s;
957 
958     if (strm == Z_NULL || strm->state == Z_NULL ||
959         strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
960 
961     strm->total_in = strm->total_out = 0;
962     strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
963     strm->data_type = Z_UNKNOWN;
964 
965     s = (deflate_state *)strm->state;
966     s->pending = 0;
967     s->pending_out = s->pending_buf;
968 
969     if (s->noheader < 0) {
970         s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
971     }
972     s->status = s->noheader ? BUSY_STATE : INIT_STATE;
973     strm->adler = 1;
974     s->last_flush = Z_NO_FLUSH;
975 
976     _tr_init(s);
977     lm_init(s);
978 
979     return Z_OK;
980 }
981 
982 /* ========================================================================= */
983 #if 0
984 int ZEXPORT deflateParams(strm, level, strategy)
985     z_streamp strm;
986     int level;
987     int strategy;
988 {
989     deflate_state *s;
990     compress_func func;
991     int err = Z_OK;
992 
993     if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
994     s = (deflate_state *)strm->state;
995 
996     if (level == Z_DEFAULT_COMPRESSION) {
997 	level = 6;
998     }
999     if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
1000 	return Z_STREAM_ERROR;
1001     }
1002     func = configuration_table[s->level].func;
1003 
1004     if (func != configuration_table[level].func && strm->total_in != 0) {
1005 	/* Flush the last buffer: */
1006 	err = deflate(strm, Z_PARTIAL_FLUSH);
1007     }
1008     if (s->level != level) {
1009 	s->level = level;
1010 	s->max_lazy_match   = configuration_table[level].max_lazy;
1011 	s->good_match       = configuration_table[level].good_length;
1012 	s->nice_match       = configuration_table[level].nice_length;
1013 	s->max_chain_length = configuration_table[level].max_chain;
1014     }
1015     s->strategy = strategy;
1016     return err;
1017 }
1018 #endif
1019 
1020 /* =========================================================================
1021  * Put a short in the pending buffer. The 16-bit value is put in MSB order.
1022  * IN assertion: the stream state is correct and there is enough room in
1023  * pending_buf.
1024  */
1025 local void putShortMSB (s, b)
1026     deflate_state *s;
1027     uInt b;
1028 {
1029     put_byte(s, (Byte)(b >> 8));
1030     put_byte(s, (Byte)(b & 0xff));
1031 }
1032 
1033 /* =========================================================================
1034  * Flush as much pending output as possible. All deflate() output goes
1035  * through this function so some applications may wish to modify it
1036  * to avoid allocating a large strm->next_out buffer and copying into it.
1037  * (See also read_buf()).
1038  */
1039 local void flush_pending(strm)
1040     z_streamp strm;
1041 {
1042     deflate_state *s = (deflate_state *) strm->state;
1043     unsigned len = s->pending;
1044 
1045     if (len > strm->avail_out) len = strm->avail_out;
1046     if (len == 0) return;
1047 
1048     if (strm->next_out != Z_NULL) {
1049       zmemcpy(strm->next_out, s->pending_out, len);
1050       strm->next_out  += len;
1051     }
1052     s->pending_out  += len;
1053     strm->total_out += len;
1054     strm->avail_out  -= len;
1055     s->pending -= len;
1056     if (s->pending == 0) {
1057         s->pending_out = s->pending_buf;
1058     }
1059 }
1060 
1061 /* ========================================================================= */
1062 int ZEXPORT deflate (strm, flush)
1063     z_streamp strm;
1064     int flush;
1065 {
1066     int old_flush; /* value of flush param for previous deflate call */
1067     deflate_state *s;
1068 
1069     if (strm == Z_NULL || strm->state == Z_NULL ||
1070 	flush > Z_FINISH || flush < 0) {
1071         return Z_STREAM_ERROR;
1072     }
1073     s = (deflate_state *)strm->state;
1074 
1075     if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
1076 	(s->status == FINISH_STATE && flush != Z_FINISH)) {
1077         ERR_RETURN(strm, Z_STREAM_ERROR);
1078     }
1079     if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
1080 
1081     s->strm = strm; /* just in case */
1082     old_flush = s->last_flush;
1083     s->last_flush = flush;
1084 
1085     /* Write the zlib header */
1086     if (s->status == INIT_STATE) {
1087 
1088         uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1089         uInt level_flags = (s->level-1) >> 1;
1090 
1091         if (level_flags > 3) level_flags = 3;
1092         header |= (level_flags << 6);
1093 	if (s->strstart != 0) header |= PRESET_DICT;
1094         header += 31 - (header % 31);
1095 
1096         s->status = BUSY_STATE;
1097         putShortMSB(s, header);
1098 
1099 	/* Save the adler32 of the preset dictionary: */
1100 	if (s->strstart != 0) {
1101 	    putShortMSB(s, (uInt)(strm->adler >> 16));
1102 	    putShortMSB(s, (uInt)(strm->adler & 0xffff));
1103 	}
1104 	strm->adler = 1L;
1105     }
1106 
1107     /* Flush as much pending output as possible */
1108     if (s->pending != 0) {
1109         flush_pending(strm);
1110         if (strm->avail_out == 0) {
1111 	    /* Since avail_out is 0, deflate will be called again with
1112 	     * more output space, but possibly with both pending and
1113 	     * avail_in equal to zero. There won't be anything to do,
1114 	     * but this is not an error situation so make sure we
1115 	     * return OK instead of BUF_ERROR at next call of deflate:
1116              */
1117 	    s->last_flush = -1;
1118 	    return Z_OK;
1119 	}
1120 
1121     /* Make sure there is something to do and avoid duplicate consecutive
1122      * flushes. For repeated and useless calls with Z_FINISH, we keep
1123      * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1124      */
1125     } else if (strm->avail_in == 0 && flush <= old_flush &&
1126 	       flush != Z_FINISH) {
1127         ERR_RETURN(strm, Z_BUF_ERROR);
1128     }
1129 
1130     /* User must not provide more input after the first FINISH: */
1131     if (s->status == FINISH_STATE && strm->avail_in != 0) {
1132         ERR_RETURN(strm, Z_BUF_ERROR);
1133     }
1134 
1135     /* Start a new block or continue the current one.
1136      */
1137     if (strm->avail_in != 0 || s->lookahead != 0 ||
1138         (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1139         block_state bstate;
1140 
1141 	bstate = (*(configuration_table[s->level].func))(s, flush);
1142 
1143         if (bstate == finish_started || bstate == finish_done) {
1144             s->status = FINISH_STATE;
1145         }
1146         if (bstate == need_more || bstate == finish_started) {
1147 	    if (strm->avail_out == 0) {
1148 	        s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1149 	    }
1150 	    return Z_OK;
1151 	    /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1152 	     * of deflate should use the same flush parameter to make sure
1153 	     * that the flush is complete. So we don't have to output an
1154 	     * empty block here, this will be done at next call. This also
1155 	     * ensures that for a very small output buffer, we emit at most
1156 	     * one empty block.
1157 	     */
1158 	}
1159         if (bstate == block_done) {
1160             if (flush == Z_PARTIAL_FLUSH) {
1161                 _tr_align(s);
1162 	    } else if (flush == Z_PACKET_FLUSH) {
1163 		/* Output just the 3-bit `stored' block type value,
1164 		   but not a zero length. */
1165 		_tr_stored_type_only(s);
1166             } else { /* FULL_FLUSH or SYNC_FLUSH */
1167                 _tr_stored_block(s, (char*)0, 0L, 0);
1168                 /* For a full flush, this empty block will be recognized
1169                  * as a special marker by inflate_sync().
1170                  */
1171                 if (flush == Z_FULL_FLUSH) {
1172                     CLEAR_HASH(s);             /* forget history */
1173                 }
1174             }
1175             flush_pending(strm);
1176 	    if (strm->avail_out == 0) {
1177 	      s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1178 	      return Z_OK;
1179 	    }
1180         }
1181     }
1182     Assert(strm->avail_out > 0, "bug2");
1183 
1184     if (flush != Z_FINISH) return Z_OK;
1185     if (s->noheader) return Z_STREAM_END;
1186 
1187     /* Write the zlib trailer (adler32) */
1188     putShortMSB(s, (uInt)(strm->adler >> 16));
1189     putShortMSB(s, (uInt)(strm->adler & 0xffff));
1190     flush_pending(strm);
1191     /* If avail_out is zero, the application will call deflate again
1192      * to flush the rest.
1193      */
1194     s->noheader = -1; /* write the trailer only once! */
1195     return s->pending != 0 ? Z_OK : Z_STREAM_END;
1196 }
1197 
1198 /* ========================================================================= */
1199 int ZEXPORT deflateEnd (strm)
1200     z_streamp strm;
1201 {
1202     int status;
1203     deflate_state *s;
1204 
1205     if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1206     s = (deflate_state *) strm->state;
1207 
1208     status = s->status;
1209     if (status != INIT_STATE && status != BUSY_STATE &&
1210 	status != FINISH_STATE) {
1211       return Z_STREAM_ERROR;
1212     }
1213 
1214     /* Deallocate in reverse order of allocations: */
1215     TRY_FREE(strm, s->pending_buf);
1216     TRY_FREE(strm, s->head);
1217     TRY_FREE(strm, s->prev);
1218     TRY_FREE(strm, s->window);
1219 
1220     ZFREE(strm, s);
1221     strm->state = Z_NULL;
1222 
1223     return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1224 }
1225 
1226 /* =========================================================================
1227  * Copy the source state to the destination state.
1228  * To simplify the source, this is not supported for 16-bit MSDOS (which
1229  * doesn't have enough memory anyway to duplicate compression states).
1230  */
1231 #if 0
1232 int ZEXPORT deflateCopy (dest, source)
1233     z_streamp dest;
1234     z_streamp source;
1235 {
1236 #ifdef MAXSEG_64K
1237     return Z_STREAM_ERROR;
1238 #else
1239     deflate_state *ds;
1240     deflate_state *ss;
1241     ushf *overlay;
1242 
1243 
1244     if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
1245         return Z_STREAM_ERROR;
1246     }
1247 
1248     ss = (deflate_state *)source->state;
1249 
1250     *dest = *source;
1251 
1252     ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1253     if (ds == Z_NULL) return Z_MEM_ERROR;
1254     dest->state = (void *) ds;
1255     *ds = *ss;
1256     ds->strm = dest;
1257 
1258     ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1259     ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
1260     ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
1261     overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1262     ds->pending_buf = (uchf *) overlay;
1263 
1264     if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1265         ds->pending_buf == Z_NULL) {
1266 	ds->status = INIT_STATE;
1267         deflateEnd (dest);
1268         return Z_MEM_ERROR;
1269     }
1270     /* following zmemcpy do not work for 16-bit MSDOS */
1271     zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1272     zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1273     zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1274     zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1275 
1276     ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1277     ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1278     ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1279 
1280     ds->l_desc.dyn_tree = ds->dyn_ltree;
1281     ds->d_desc.dyn_tree = ds->dyn_dtree;
1282     ds->bl_desc.dyn_tree = ds->bl_tree;
1283 
1284     return Z_OK;
1285 #endif
1286 }
1287 #endif
1288 
1289 /* ===========================================================================
1290  * Return the number of bytes of output which are immediately available
1291  * for output from the decompressor.
1292  */
1293 #if 0
1294 int deflateOutputPending (strm)
1295     z_streamp strm;
1296 {
1297     if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1298 
1299     return ((deflate_state *)(strm->state))->pending;
1300 }
1301 #endif
1302 
1303 /* ===========================================================================
1304  * Read a new buffer from the current input stream, update the adler32
1305  * and total number of bytes read.  All deflate() input goes through
1306  * this function so some applications may wish to modify it to avoid
1307  * allocating a large strm->next_in buffer and copying from it.
1308  * (See also flush_pending()).
1309  */
1310 local int read_buf(strm, buf, size)
1311     z_streamp strm;
1312     Bytef *buf;
1313     unsigned size;
1314 {
1315     unsigned len = strm->avail_in;
1316 
1317     if (len > size) len = size;
1318     if (len == 0) return 0;
1319 
1320     strm->avail_in  -= len;
1321 
1322     if (!((deflate_state *)(strm->state))->noheader) {
1323         strm->adler = adler32(strm->adler, strm->next_in, len);
1324     }
1325     zmemcpy(buf, strm->next_in, len);
1326     strm->next_in  += len;
1327     strm->total_in += len;
1328 
1329     return (int)len;
1330 }
1331 
1332 /* ===========================================================================
1333  * Initialize the "longest match" routines for a new zlib stream
1334  */
1335 local void lm_init (s)
1336     deflate_state *s;
1337 {
1338     s->window_size = (ulg)2L*s->w_size;
1339 
1340     CLEAR_HASH(s);
1341 
1342     /* Set the default configuration parameters:
1343      */
1344     s->max_lazy_match   = configuration_table[s->level].max_lazy;
1345     s->good_match       = configuration_table[s->level].good_length;
1346     s->nice_match       = configuration_table[s->level].nice_length;
1347     s->max_chain_length = configuration_table[s->level].max_chain;
1348 
1349     s->strstart = 0;
1350     s->block_start = 0L;
1351     s->lookahead = 0;
1352     s->match_length = s->prev_length = MIN_MATCH-1;
1353     s->match_available = 0;
1354     s->ins_h = 0;
1355 #ifdef ASMV
1356     match_init(); /* initialize the asm code */
1357 #endif
1358 }
1359 
1360 /* ===========================================================================
1361  * Set match_start to the longest match starting at the given string and
1362  * return its length. Matches shorter or equal to prev_length are discarded,
1363  * in which case the result is equal to prev_length and match_start is
1364  * garbage.
1365  * IN assertions: cur_match is the head of the hash chain for the current
1366  *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1367  * OUT assertion: the match length is not greater than s->lookahead.
1368  */
1369 #ifndef ASMV
1370 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1371  * match.S. The code will be functionally equivalent.
1372  */
1373 #ifndef FASTEST
1374 local uInt longest_match(s, cur_match)
1375     deflate_state *s;
1376     IPos cur_match;                             /* current match */
1377 {
1378     unsigned chain_length = s->max_chain_length;/* max hash chain length */
1379     Bytef *scan = s->window + s->strstart; /* current string */
1380     Bytef *match;                       /* matched string */
1381     int len;                           /* length of current match */
1382     int best_len = s->prev_length;              /* best match length so far */
1383     int nice_match = s->nice_match;             /* stop if match long enough */
1384     IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1385         s->strstart - (IPos)MAX_DIST(s) : NIL;
1386     /* Stop when cur_match becomes <= limit. To simplify the code,
1387      * we prevent matches with the string of window index 0.
1388      */
1389     Posf *prev = s->prev;
1390     uInt wmask = s->w_mask;
1391 
1392 #ifdef UNALIGNED_OK
1393     /* Compare two bytes at a time. Note: this is not always beneficial.
1394      * Try with and without -DUNALIGNED_OK to check.
1395      */
1396     Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1397     ush scan_start = *(ushf*)scan;
1398     ush scan_end   = *(ushf*)(scan+best_len-1);
1399 #else
1400     Bytef *strend = s->window + s->strstart + MAX_MATCH;
1401     Byte scan_end1  = scan[best_len-1];
1402     Byte scan_end   = scan[best_len];
1403 #endif
1404 
1405     /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1406      * It is easy to get rid of this optimization if necessary.
1407      */
1408     Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1409 
1410     /* Do not waste too much time if we already have a good match: */
1411     if (s->prev_length >= s->good_match) {
1412         chain_length >>= 2;
1413     }
1414     /* Do not look for matches beyond the end of the input. This is necessary
1415      * to make deflate deterministic.
1416      */
1417     if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1418 
1419     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1420 
1421     do {
1422         Assert(cur_match < s->strstart, "no future");
1423         match = s->window + cur_match;
1424 
1425         /* Skip to next match if the match length cannot increase
1426          * or if the match length is less than 2:
1427          */
1428 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1429         /* This code assumes sizeof(unsigned short) == 2. Do not use
1430          * UNALIGNED_OK if your compiler uses a different size.
1431          */
1432         if (*(ushf*)(match+best_len-1) != scan_end ||
1433             *(ushf*)match != scan_start) continue;
1434 
1435         /* It is not necessary to compare scan[2] and match[2] since they are
1436          * always equal when the other bytes match, given that the hash keys
1437          * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1438          * strstart+3, +5, ... up to strstart+257. We check for insufficient
1439          * lookahead only every 4th comparison; the 128th check will be made
1440          * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1441          * necessary to put more guard bytes at the end of the window, or
1442          * to check more often for insufficient lookahead.
1443          */
1444         Assert(scan[2] == match[2], "scan[2]?");
1445         scan++, match++;
1446         do {
1447         } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1448                  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1449                  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1450                  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1451                  scan < strend);
1452         /* The funny "do {}" generates better code on most compilers */
1453 
1454         /* Here, scan <= window+strstart+257 */
1455         Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1456         if (*scan == *match) scan++;
1457 
1458         len = (MAX_MATCH - 1) - (int)(strend-scan);
1459         scan = strend - (MAX_MATCH-1);
1460 
1461 #else /* UNALIGNED_OK */
1462 
1463         if (match[best_len]   != scan_end  ||
1464             match[best_len-1] != scan_end1 ||
1465             *match            != *scan     ||
1466             *++match          != scan[1])      continue;
1467 
1468         /* The check at best_len-1 can be removed because it will be made
1469          * again later. (This heuristic is not always a win.)
1470          * It is not necessary to compare scan[2] and match[2] since they
1471          * are always equal when the other bytes match, given that
1472          * the hash keys are equal and that HASH_BITS >= 8.
1473          */
1474         scan += 2, match++;
1475         Assert(*scan == *match, "match[2]?");
1476 
1477         /* We check for insufficient lookahead only every 8th comparison;
1478          * the 256th check will be made at strstart+258.
1479          */
1480         do {
1481         } while (*++scan == *++match && *++scan == *++match &&
1482                  *++scan == *++match && *++scan == *++match &&
1483                  *++scan == *++match && *++scan == *++match &&
1484                  *++scan == *++match && *++scan == *++match &&
1485                  scan < strend);
1486 
1487         Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1488 
1489         len = MAX_MATCH - (int)(strend - scan);
1490         scan = strend - MAX_MATCH;
1491 
1492 #endif /* UNALIGNED_OK */
1493 
1494         if (len > best_len) {
1495             s->match_start = cur_match;
1496             best_len = len;
1497             if (len >= nice_match) break;
1498 #ifdef UNALIGNED_OK
1499             scan_end = *(ushf*)(scan+best_len-1);
1500 #else
1501             scan_end1  = scan[best_len-1];
1502             scan_end   = scan[best_len];
1503 #endif
1504         }
1505     } while ((cur_match = prev[cur_match & wmask]) > limit
1506              && --chain_length != 0);
1507 
1508     if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
1509     return s->lookahead;
1510 }
1511 
1512 #else /* FASTEST */
1513 /* ---------------------------------------------------------------------------
1514  * Optimized version for level == 1 only
1515  */
1516 local uInt longest_match(s, cur_match)
1517     deflate_state *s;
1518     IPos cur_match;                             /* current match */
1519 {
1520     register Bytef *scan = s->window + s->strstart; /* current string */
1521     register Bytef *match;                       /* matched string */
1522     register int len;                           /* length of current match */
1523     register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1524 
1525     /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1526      * It is easy to get rid of this optimization if necessary.
1527      */
1528     Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1529 
1530     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1531 
1532     Assert(cur_match < s->strstart, "no future");
1533 
1534     match = s->window + cur_match;
1535 
1536     /* Return failure if the match length is less than 2:
1537      */
1538     if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
1539 
1540     /* The check at best_len-1 can be removed because it will be made
1541      * again later. (This heuristic is not always a win.)
1542      * It is not necessary to compare scan[2] and match[2] since they
1543      * are always equal when the other bytes match, given that
1544      * the hash keys are equal and that HASH_BITS >= 8.
1545      */
1546     scan += 2, match += 2;
1547     Assert(*scan == *match, "match[2]?");
1548 
1549     /* We check for insufficient lookahead only every 8th comparison;
1550      * the 256th check will be made at strstart+258.
1551      */
1552     do {
1553     } while (*++scan == *++match && *++scan == *++match &&
1554 	     *++scan == *++match && *++scan == *++match &&
1555 	     *++scan == *++match && *++scan == *++match &&
1556 	     *++scan == *++match && *++scan == *++match &&
1557 	     scan < strend);
1558 
1559     Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1560 
1561     len = MAX_MATCH - (int)(strend - scan);
1562 
1563     if (len < MIN_MATCH) return MIN_MATCH - 1;
1564 
1565     s->match_start = cur_match;
1566     return len <= s->lookahead ? len : s->lookahead;
1567 }
1568 #endif /* FASTEST */
1569 #endif /* ASMV */
1570 
1571 #ifdef DEBUG_ZLIB
1572 /* ===========================================================================
1573  * Check that the match at match_start is indeed a match.
1574  */
1575 local void check_match(s, start, match, length)
1576     deflate_state *s;
1577     IPos start, match;
1578     int length;
1579 {
1580     /* check that the match is indeed a match */
1581     if (zmemcmp(s->window + match,
1582                 s->window + start, length) != EQUAL) {
1583         fprintf(stderr, " start %u, match %u, length %d\n",
1584 		start, match, length);
1585         do {
1586 	    fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1587 	} while (--length != 0);
1588         z_error("invalid match");
1589     }
1590     if (z_verbose > 1) {
1591         fprintf(stderr,"\\[%d,%d]", start-match, length);
1592         do { putc(s->window[start++], stderr); } while (--length != 0);
1593     }
1594 }
1595 #else
1596 #  define check_match(s, start, match, length)
1597 #endif
1598 
1599 /* ===========================================================================
1600  * Fill the window when the lookahead becomes insufficient.
1601  * Updates strstart and lookahead.
1602  *
1603  * IN assertion: lookahead < MIN_LOOKAHEAD
1604  * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1605  *    At least one byte has been read, or avail_in == 0; reads are
1606  *    performed for at least two bytes (required for the zip translate_eol
1607  *    option -- not supported here).
1608  */
1609 local void fill_window(s)
1610     deflate_state *s;
1611 {
1612     unsigned n, m;
1613     Posf *p;
1614     unsigned more;    /* Amount of free space at the end of the window. */
1615     uInt wsize = s->w_size;
1616 
1617     do {
1618         more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1619 
1620         /* Deal with !@#$% 64K limit: */
1621         if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1622             more = wsize;
1623 
1624         } else if (more == (unsigned)(-1)) {
1625             /* Very unlikely, but possible on 16 bit machine if strstart == 0
1626              * and lookahead == 1 (input done one byte at time)
1627              */
1628             more--;
1629 
1630         /* If the window is almost full and there is insufficient lookahead,
1631          * move the upper half to the lower one to make room in the upper half.
1632          */
1633         } else if (s->strstart >= wsize+MAX_DIST(s)) {
1634 
1635             zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
1636             s->match_start -= wsize;
1637             s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
1638             s->block_start -= (long) wsize;
1639 
1640             /* Slide the hash table (could be avoided with 32 bit values
1641                at the expense of memory usage). We slide even when level == 0
1642                to keep the hash table consistent if we switch back to level > 0
1643                later. (Using level 0 permanently is not an optimal usage of
1644                zlib, so we don't care about this pathological case.)
1645              */
1646 	    n = s->hash_size;
1647 	    p = &s->head[n];
1648 	    do {
1649 		m = *--p;
1650 		*p = (Pos)(m >= wsize ? m-wsize : NIL);
1651 	    } while (--n);
1652 
1653 	    n = wsize;
1654 #ifndef FASTEST
1655 	    p = &s->prev[n];
1656 	    do {
1657 		m = *--p;
1658 		*p = (Pos)(m >= wsize ? m-wsize : NIL);
1659 		/* If n is not on any hash chain, prev[n] is garbage but
1660 		 * its value will never be used.
1661 		 */
1662 	    } while (--n);
1663 #endif
1664             more += wsize;
1665         }
1666         if (s->strm->avail_in == 0) return;
1667 
1668         /* If there was no sliding:
1669          *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1670          *    more == window_size - lookahead - strstart
1671          * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1672          * => more >= window_size - 2*WSIZE + 2
1673          * In the BIG_MEM or MMAP case (not yet supported),
1674          *   window_size == input_size + MIN_LOOKAHEAD  &&
1675          *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1676          * Otherwise, window_size == 2*WSIZE so more >= 2.
1677          * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1678          */
1679         Assert(more >= 2, "more < 2");
1680 
1681         n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
1682         s->lookahead += n;
1683 
1684         /* Initialize the hash value now that we have some input: */
1685         if (s->lookahead >= MIN_MATCH) {
1686             s->ins_h = s->window[s->strstart];
1687             UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1688 #if MIN_MATCH != 3
1689             Call UPDATE_HASH() MIN_MATCH-3 more times
1690 #endif
1691         }
1692         /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1693          * but this is not important since only literal bytes will be emitted.
1694          */
1695 
1696     } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1697 }
1698 
1699 /* ===========================================================================
1700  * Flush the current block, with given end-of-file flag.
1701  * IN assertion: strstart is set to the end of the current match.
1702  */
1703 #define FLUSH_BLOCK_ONLY(s, eof) { \
1704    _tr_flush_block(s, (s->block_start >= 0L ? \
1705                    (charf *)&s->window[(unsigned)s->block_start] : \
1706                    (charf *)Z_NULL), \
1707 		(ulg)((long)s->strstart - s->block_start), \
1708 		(eof)); \
1709    s->block_start = s->strstart; \
1710    flush_pending(s->strm); \
1711    Tracev((stderr,"[FLUSH]")); \
1712 }
1713 
1714 /* Same but force premature exit if necessary. */
1715 #define FLUSH_BLOCK(s, eof) { \
1716    FLUSH_BLOCK_ONLY(s, eof); \
1717    if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1718 }
1719 
1720 /* ===========================================================================
1721  * Copy without compression as much as possible from the input stream, return
1722  * the current block state.
1723  * This function does not insert new strings in the dictionary since
1724  * uncompressible data is probably not useful. This function is used
1725  * only for the level=0 compression option.
1726  * NOTE: this function should be optimized to avoid extra copying from
1727  * window to pending_buf.
1728  */
1729 local block_state deflate_stored(s, flush)
1730     deflate_state *s;
1731     int flush;
1732 {
1733     /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1734      * to pending_buf_size, and each stored block has a 5 byte header:
1735      */
1736     ulg max_block_size = 0xffff;
1737     ulg max_start;
1738 
1739     if (max_block_size > s->pending_buf_size - 5) {
1740         max_block_size = s->pending_buf_size - 5;
1741     }
1742 
1743     /* Copy as much as possible from input to output: */
1744     for (;;) {
1745         /* Fill the window as much as possible: */
1746         if (s->lookahead <= 1) {
1747 
1748             Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1749 		   s->block_start >= (long)s->w_size, "slide too late");
1750 
1751             fill_window(s);
1752             if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1753 
1754             if (s->lookahead == 0) break; /* flush the current block */
1755         }
1756 	Assert(s->block_start >= 0L, "block gone");
1757 
1758 	s->strstart += s->lookahead;
1759 	s->lookahead = 0;
1760 
1761 	/* Emit a stored block if pending_buf will be full: */
1762  	max_start = s->block_start + max_block_size;
1763         if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1764 	    /* strstart == 0 is possible when wraparound on 16-bit machine */
1765 	    s->lookahead = (uInt)(s->strstart - max_start);
1766 	    s->strstart = (uInt)max_start;
1767             FLUSH_BLOCK(s, 0);
1768 	}
1769 	/* Flush if we may have to slide, otherwise block_start may become
1770          * negative and the data will be gone:
1771          */
1772         if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1773             FLUSH_BLOCK(s, 0);
1774 	}
1775     }
1776     FLUSH_BLOCK(s, flush == Z_FINISH);
1777     return flush == Z_FINISH ? finish_done : block_done;
1778 }
1779 
1780 /* ===========================================================================
1781  * Compress as much as possible from the input stream, return the current
1782  * block state.
1783  * This function does not perform lazy evaluation of matches and inserts
1784  * new strings in the dictionary only for unmatched strings or for short
1785  * matches. It is used only for the fast compression options.
1786  */
1787 local block_state deflate_fast(s, flush)
1788     deflate_state *s;
1789     int flush;
1790 {
1791     IPos hash_head = NIL; /* head of the hash chain */
1792     int bflush;           /* set if current block must be flushed */
1793 
1794     for (;;) {
1795         /* Make sure that we always have enough lookahead, except
1796          * at the end of the input file. We need MAX_MATCH bytes
1797          * for the next match, plus MIN_MATCH bytes to insert the
1798          * string following the next match.
1799          */
1800         if (s->lookahead < MIN_LOOKAHEAD) {
1801             fill_window(s);
1802             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1803 	        return need_more;
1804 	    }
1805             if (s->lookahead == 0) break; /* flush the current block */
1806         }
1807 
1808         /* Insert the string window[strstart .. strstart+2] in the
1809          * dictionary, and set hash_head to the head of the hash chain:
1810          */
1811         if (s->lookahead >= MIN_MATCH) {
1812             INSERT_STRING(s, s->strstart, hash_head);
1813         }
1814 
1815         /* Find the longest match, discarding those <= prev_length.
1816          * At this point we have always match_length < MIN_MATCH
1817          */
1818         if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1819             /* To simplify the code, we prevent matches with the string
1820              * of window index 0 (in particular we have to avoid a match
1821              * of the string with itself at the start of the input file).
1822              */
1823             if (s->strategy != Z_HUFFMAN_ONLY) {
1824                 s->match_length = longest_match (s, hash_head);
1825             }
1826             /* longest_match() sets match_start */
1827         }
1828         if (s->match_length >= MIN_MATCH) {
1829             check_match(s, s->strstart, s->match_start, s->match_length);
1830 
1831             _tr_tally_dist(s, s->strstart - s->match_start,
1832                            s->match_length - MIN_MATCH, bflush);
1833 
1834             s->lookahead -= s->match_length;
1835 
1836             /* Insert new strings in the hash table only if the match length
1837              * is not too large. This saves time but degrades compression.
1838              */
1839 #ifndef FASTEST
1840             if (s->match_length <= s->max_insert_length &&
1841                 s->lookahead >= MIN_MATCH) {
1842                 s->match_length--; /* string at strstart already in hash table */
1843                 do {
1844                     s->strstart++;
1845                     INSERT_STRING(s, s->strstart, hash_head);
1846                     /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1847                      * always MIN_MATCH bytes ahead.
1848                      */
1849                 } while (--s->match_length != 0);
1850                 s->strstart++;
1851             } else
1852 #endif
1853 	    {
1854                 s->strstart += s->match_length;
1855                 s->match_length = 0;
1856                 s->ins_h = s->window[s->strstart];
1857                 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1858 #if MIN_MATCH != 3
1859                 Call UPDATE_HASH() MIN_MATCH-3 more times
1860 #endif
1861                 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1862                  * matter since it will be recomputed at next deflate call.
1863                  */
1864             }
1865         } else {
1866             /* No match, output a literal byte */
1867             Tracevv((stderr,"%c", s->window[s->strstart]));
1868             _tr_tally_lit (s, s->window[s->strstart], bflush);
1869             s->lookahead--;
1870             s->strstart++;
1871         }
1872         if (bflush) FLUSH_BLOCK(s, 0);
1873     }
1874     FLUSH_BLOCK(s, flush == Z_FINISH);
1875     return flush == Z_FINISH ? finish_done : block_done;
1876 }
1877 
1878 /* ===========================================================================
1879  * Same as above, but achieves better compression. We use a lazy
1880  * evaluation for matches: a match is finally adopted only if there is
1881  * no better match at the next window position.
1882  */
1883 local block_state deflate_slow(s, flush)
1884     deflate_state *s;
1885     int flush;
1886 {
1887     IPos hash_head = NIL;    /* head of hash chain */
1888     int bflush;              /* set if current block must be flushed */
1889 
1890     /* Process the input block. */
1891     for (;;) {
1892         /* Make sure that we always have enough lookahead, except
1893          * at the end of the input file. We need MAX_MATCH bytes
1894          * for the next match, plus MIN_MATCH bytes to insert the
1895          * string following the next match.
1896          */
1897         if (s->lookahead < MIN_LOOKAHEAD) {
1898             fill_window(s);
1899             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1900 	        return need_more;
1901 	    }
1902             if (s->lookahead == 0) break; /* flush the current block */
1903         }
1904 
1905         /* Insert the string window[strstart .. strstart+2] in the
1906          * dictionary, and set hash_head to the head of the hash chain:
1907          */
1908         if (s->lookahead >= MIN_MATCH) {
1909             INSERT_STRING(s, s->strstart, hash_head);
1910         }
1911 
1912         /* Find the longest match, discarding those <= prev_length.
1913          */
1914         s->prev_length = s->match_length, s->prev_match = s->match_start;
1915         s->match_length = MIN_MATCH-1;
1916 
1917         if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1918             s->strstart - hash_head <= MAX_DIST(s)) {
1919             /* To simplify the code, we prevent matches with the string
1920              * of window index 0 (in particular we have to avoid a match
1921              * of the string with itself at the start of the input file).
1922              */
1923             if (s->strategy != Z_HUFFMAN_ONLY) {
1924                 s->match_length = longest_match (s, hash_head);
1925             }
1926             /* longest_match() sets match_start */
1927 
1928             if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1929                  (s->match_length == MIN_MATCH &&
1930                   s->strstart - s->match_start > TOO_FAR))) {
1931 
1932                 /* If prev_match is also MIN_MATCH, match_start is garbage
1933                  * but we will ignore the current match anyway.
1934                  */
1935                 s->match_length = MIN_MATCH-1;
1936             }
1937         }
1938         /* If there was a match at the previous step and the current
1939          * match is not better, output the previous match:
1940          */
1941         if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1942             uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1943             /* Do not insert strings in hash table beyond this. */
1944 
1945             check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1946 
1947             _tr_tally_dist(s, s->strstart -1 - s->prev_match,
1948 			   s->prev_length - MIN_MATCH, bflush);
1949 
1950             /* Insert in hash table all strings up to the end of the match.
1951              * strstart-1 and strstart are already inserted. If there is not
1952              * enough lookahead, the last two strings are not inserted in
1953              * the hash table.
1954              */
1955             s->lookahead -= s->prev_length-1;
1956             s->prev_length -= 2;
1957             do {
1958                 if (++s->strstart <= max_insert) {
1959                     INSERT_STRING(s, s->strstart, hash_head);
1960                 }
1961             } while (--s->prev_length != 0);
1962             s->match_available = 0;
1963             s->match_length = MIN_MATCH-1;
1964             s->strstart++;
1965 
1966             if (bflush) FLUSH_BLOCK(s, 0);
1967 
1968         } else if (s->match_available) {
1969             /* If there was no match at the previous position, output a
1970              * single literal. If there was a match but the current match
1971              * is longer, truncate the previous match to a single literal.
1972              */
1973             Tracevv((stderr,"%c", s->window[s->strstart-1]));
1974 	    _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1975 	    if (bflush) {
1976                 FLUSH_BLOCK_ONLY(s, 0);
1977             }
1978             s->strstart++;
1979             s->lookahead--;
1980             if (s->strm->avail_out == 0) return need_more;
1981         } else {
1982             /* There is no previous match to compare with, wait for
1983              * the next step to decide.
1984              */
1985             s->match_available = 1;
1986             s->strstart++;
1987             s->lookahead--;
1988         }
1989     }
1990     Assert (flush != Z_NO_FLUSH, "no flush?");
1991     if (s->match_available) {
1992         Tracevv((stderr,"%c", s->window[s->strstart-1]));
1993         _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1994         s->match_available = 0;
1995     }
1996     FLUSH_BLOCK(s, flush == Z_FINISH);
1997     return flush == Z_FINISH ? finish_done : block_done;
1998 }
1999 /* --- deflate.c */
2000 
2001 /* +++ trees.c */
2002 
2003 /* trees.c -- output deflated data using Huffman coding
2004  * Copyright (C) 1995-2002 Jean-loup Gailly
2005  * For conditions of distribution and use, see copyright notice in zlib.h
2006  */
2007 
2008 /*
2009  *  ALGORITHM
2010  *
2011  *      The "deflation" process uses several Huffman trees. The more
2012  *      common source values are represented by shorter bit sequences.
2013  *
2014  *      Each code tree is stored in a compressed form which is itself
2015  * a Huffman encoding of the lengths of all the code strings (in
2016  * ascending order by source values).  The actual code strings are
2017  * reconstructed from the lengths in the inflate process, as described
2018  * in the deflate specification.
2019  *
2020  *  REFERENCES
2021  *
2022  *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
2023  *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
2024  *
2025  *      Storer, James A.
2026  *          Data Compression:  Methods and Theory, pp. 49-50.
2027  *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
2028  *
2029  *      Sedgewick, R.
2030  *          Algorithms, p290.
2031  *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
2032  */
2033 
2034 /* @(#) $Id: zlib.c,v 1.23 2006/01/14 18:58:05 christos Exp $ */
2035 
2036 /* #define GEN_TREES_H */
2037 
2038 /* #include "deflate.h" */
2039 
2040 #ifdef DEBUG_ZLIB
2041 #  include <ctype.h>
2042 #endif
2043 
2044 /* ===========================================================================
2045  * Constants
2046  */
2047 
2048 #define MAX_BL_BITS 7
2049 /* Bit length codes must not exceed MAX_BL_BITS bits */
2050 
2051 #define END_BLOCK 256
2052 /* end of block literal code */
2053 
2054 #define REP_3_6      16
2055 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
2056 
2057 #define REPZ_3_10    17
2058 /* repeat a zero length 3-10 times  (3 bits of repeat count) */
2059 
2060 #define REPZ_11_138  18
2061 /* repeat a zero length 11-138 times  (7 bits of repeat count) */
2062 
2063 local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
2064    = {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};
2065 
2066 local const int extra_dbits[D_CODES] /* extra bits for each distance code */
2067    = {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};
2068 
2069 local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
2070    = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
2071 
2072 local const uch bl_order[BL_CODES]
2073    = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
2074 /* The lengths of the bit length codes are sent in order of decreasing
2075  * probability, to avoid transmitting the lengths for unused bit length codes.
2076  */
2077 
2078 #define Buf_size (8 * 2*sizeof(char))
2079 /* Number of bits used within bi_buf. (bi_buf might be implemented on
2080  * more than 16 bits on some systems.)
2081  */
2082 
2083 /* ===========================================================================
2084  * Local data. These are initialized only once.
2085  */
2086 
2087 #define DIST_CODE_LEN  512 /* see definition of array dist_code below */
2088 
2089 #if defined(GEN_TREES_H) || !defined(STDC)
2090 /* non ANSI compilers may not accept trees.h */
2091 
2092 local ct_data static_ltree[L_CODES+2];
2093 /* The static literal tree. Since the bit lengths are imposed, there is no
2094  * need for the L_CODES extra codes used during heap construction. However
2095  * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
2096  * below).
2097  */
2098 
2099 local ct_data static_dtree[D_CODES];
2100 /* The static distance tree. (Actually a trivial tree since all codes use
2101  * 5 bits.)
2102  */
2103 
2104 uch _dist_code[DIST_CODE_LEN];
2105 /* Distance codes. The first 256 values correspond to the distances
2106  * 3 .. 258, the last 256 values correspond to the top 8 bits of
2107  * the 15 bit distances.
2108  */
2109 
2110 uch _length_code[MAX_MATCH-MIN_MATCH+1];
2111 /* length code for each normalized match length (0 == MIN_MATCH) */
2112 
2113 local int base_length[LENGTH_CODES];
2114 /* First normalized length for each code (0 = MIN_MATCH) */
2115 
2116 local int base_dist[D_CODES];
2117 /* First normalized distance for each code (0 = distance of 1) */
2118 
2119 #else
2120 /* +++ trees.h */
2121 
2122 /* header created automatically with -DGEN_TREES_H */
2123 
2124 local const ct_data static_ltree[L_CODES+2] = {
2125 {{ 12},{  8}}, {{140},{  8}}, {{ 76},{  8}}, {{204},{  8}}, {{ 44},{  8}},
2126 {{172},{  8}}, {{108},{  8}}, {{236},{  8}}, {{ 28},{  8}}, {{156},{  8}},
2127 {{ 92},{  8}}, {{220},{  8}}, {{ 60},{  8}}, {{188},{  8}}, {{124},{  8}},
2128 {{252},{  8}}, {{  2},{  8}}, {{130},{  8}}, {{ 66},{  8}}, {{194},{  8}},
2129 {{ 34},{  8}}, {{162},{  8}}, {{ 98},{  8}}, {{226},{  8}}, {{ 18},{  8}},
2130 {{146},{  8}}, {{ 82},{  8}}, {{210},{  8}}, {{ 50},{  8}}, {{178},{  8}},
2131 {{114},{  8}}, {{242},{  8}}, {{ 10},{  8}}, {{138},{  8}}, {{ 74},{  8}},
2132 {{202},{  8}}, {{ 42},{  8}}, {{170},{  8}}, {{106},{  8}}, {{234},{  8}},
2133 {{ 26},{  8}}, {{154},{  8}}, {{ 90},{  8}}, {{218},{  8}}, {{ 58},{  8}},
2134 {{186},{  8}}, {{122},{  8}}, {{250},{  8}}, {{  6},{  8}}, {{134},{  8}},
2135 {{ 70},{  8}}, {{198},{  8}}, {{ 38},{  8}}, {{166},{  8}}, {{102},{  8}},
2136 {{230},{  8}}, {{ 22},{  8}}, {{150},{  8}}, {{ 86},{  8}}, {{214},{  8}},
2137 {{ 54},{  8}}, {{182},{  8}}, {{118},{  8}}, {{246},{  8}}, {{ 14},{  8}},
2138 {{142},{  8}}, {{ 78},{  8}}, {{206},{  8}}, {{ 46},{  8}}, {{174},{  8}},
2139 {{110},{  8}}, {{238},{  8}}, {{ 30},{  8}}, {{158},{  8}}, {{ 94},{  8}},
2140 {{222},{  8}}, {{ 62},{  8}}, {{190},{  8}}, {{126},{  8}}, {{254},{  8}},
2141 {{  1},{  8}}, {{129},{  8}}, {{ 65},{  8}}, {{193},{  8}}, {{ 33},{  8}},
2142 {{161},{  8}}, {{ 97},{  8}}, {{225},{  8}}, {{ 17},{  8}}, {{145},{  8}},
2143 {{ 81},{  8}}, {{209},{  8}}, {{ 49},{  8}}, {{177},{  8}}, {{113},{  8}},
2144 {{241},{  8}}, {{  9},{  8}}, {{137},{  8}}, {{ 73},{  8}}, {{201},{  8}},
2145 {{ 41},{  8}}, {{169},{  8}}, {{105},{  8}}, {{233},{  8}}, {{ 25},{  8}},
2146 {{153},{  8}}, {{ 89},{  8}}, {{217},{  8}}, {{ 57},{  8}}, {{185},{  8}},
2147 {{121},{  8}}, {{249},{  8}}, {{  5},{  8}}, {{133},{  8}}, {{ 69},{  8}},
2148 {{197},{  8}}, {{ 37},{  8}}, {{165},{  8}}, {{101},{  8}}, {{229},{  8}},
2149 {{ 21},{  8}}, {{149},{  8}}, {{ 85},{  8}}, {{213},{  8}}, {{ 53},{  8}},
2150 {{181},{  8}}, {{117},{  8}}, {{245},{  8}}, {{ 13},{  8}}, {{141},{  8}},
2151 {{ 77},{  8}}, {{205},{  8}}, {{ 45},{  8}}, {{173},{  8}}, {{109},{  8}},
2152 {{237},{  8}}, {{ 29},{  8}}, {{157},{  8}}, {{ 93},{  8}}, {{221},{  8}},
2153 {{ 61},{  8}}, {{189},{  8}}, {{125},{  8}}, {{253},{  8}}, {{ 19},{  9}},
2154 {{275},{  9}}, {{147},{  9}}, {{403},{  9}}, {{ 83},{  9}}, {{339},{  9}},
2155 {{211},{  9}}, {{467},{  9}}, {{ 51},{  9}}, {{307},{  9}}, {{179},{  9}},
2156 {{435},{  9}}, {{115},{  9}}, {{371},{  9}}, {{243},{  9}}, {{499},{  9}},
2157 {{ 11},{  9}}, {{267},{  9}}, {{139},{  9}}, {{395},{  9}}, {{ 75},{  9}},
2158 {{331},{  9}}, {{203},{  9}}, {{459},{  9}}, {{ 43},{  9}}, {{299},{  9}},
2159 {{171},{  9}}, {{427},{  9}}, {{107},{  9}}, {{363},{  9}}, {{235},{  9}},
2160 {{491},{  9}}, {{ 27},{  9}}, {{283},{  9}}, {{155},{  9}}, {{411},{  9}},
2161 {{ 91},{  9}}, {{347},{  9}}, {{219},{  9}}, {{475},{  9}}, {{ 59},{  9}},
2162 {{315},{  9}}, {{187},{  9}}, {{443},{  9}}, {{123},{  9}}, {{379},{  9}},
2163 {{251},{  9}}, {{507},{  9}}, {{  7},{  9}}, {{263},{  9}}, {{135},{  9}},
2164 {{391},{  9}}, {{ 71},{  9}}, {{327},{  9}}, {{199},{  9}}, {{455},{  9}},
2165 {{ 39},{  9}}, {{295},{  9}}, {{167},{  9}}, {{423},{  9}}, {{103},{  9}},
2166 {{359},{  9}}, {{231},{  9}}, {{487},{  9}}, {{ 23},{  9}}, {{279},{  9}},
2167 {{151},{  9}}, {{407},{  9}}, {{ 87},{  9}}, {{343},{  9}}, {{215},{  9}},
2168 {{471},{  9}}, {{ 55},{  9}}, {{311},{  9}}, {{183},{  9}}, {{439},{  9}},
2169 {{119},{  9}}, {{375},{  9}}, {{247},{  9}}, {{503},{  9}}, {{ 15},{  9}},
2170 {{271},{  9}}, {{143},{  9}}, {{399},{  9}}, {{ 79},{  9}}, {{335},{  9}},
2171 {{207},{  9}}, {{463},{  9}}, {{ 47},{  9}}, {{303},{  9}}, {{175},{  9}},
2172 {{431},{  9}}, {{111},{  9}}, {{367},{  9}}, {{239},{  9}}, {{495},{  9}},
2173 {{ 31},{  9}}, {{287},{  9}}, {{159},{  9}}, {{415},{  9}}, {{ 95},{  9}},
2174 {{351},{  9}}, {{223},{  9}}, {{479},{  9}}, {{ 63},{  9}}, {{319},{  9}},
2175 {{191},{  9}}, {{447},{  9}}, {{127},{  9}}, {{383},{  9}}, {{255},{  9}},
2176 {{511},{  9}}, {{  0},{  7}}, {{ 64},{  7}}, {{ 32},{  7}}, {{ 96},{  7}},
2177 {{ 16},{  7}}, {{ 80},{  7}}, {{ 48},{  7}}, {{112},{  7}}, {{  8},{  7}},
2178 {{ 72},{  7}}, {{ 40},{  7}}, {{104},{  7}}, {{ 24},{  7}}, {{ 88},{  7}},
2179 {{ 56},{  7}}, {{120},{  7}}, {{  4},{  7}}, {{ 68},{  7}}, {{ 36},{  7}},
2180 {{100},{  7}}, {{ 20},{  7}}, {{ 84},{  7}}, {{ 52},{  7}}, {{116},{  7}},
2181 {{  3},{  8}}, {{131},{  8}}, {{ 67},{  8}}, {{195},{  8}}, {{ 35},{  8}},
2182 {{163},{  8}}, {{ 99},{  8}}, {{227},{  8}}
2183 };
2184 
2185 local const ct_data static_dtree[D_CODES] = {
2186 {{ 0},{ 5}}, {{16},{ 5}}, {{ 8},{ 5}}, {{24},{ 5}}, {{ 4},{ 5}},
2187 {{20},{ 5}}, {{12},{ 5}}, {{28},{ 5}}, {{ 2},{ 5}}, {{18},{ 5}},
2188 {{10},{ 5}}, {{26},{ 5}}, {{ 6},{ 5}}, {{22},{ 5}}, {{14},{ 5}},
2189 {{30},{ 5}}, {{ 1},{ 5}}, {{17},{ 5}}, {{ 9},{ 5}}, {{25},{ 5}},
2190 {{ 5},{ 5}}, {{21},{ 5}}, {{13},{ 5}}, {{29},{ 5}}, {{ 3},{ 5}},
2191 {{19},{ 5}}, {{11},{ 5}}, {{27},{ 5}}, {{ 7},{ 5}}, {{23},{ 5}}
2192 };
2193 
2194 const uch _dist_code[DIST_CODE_LEN] = {
2195  0,  1,  2,  3,  4,  4,  5,  5,  6,  6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  8,
2196  8,  8,  8,  8,  9,  9,  9,  9,  9,  9,  9,  9, 10, 10, 10, 10, 10, 10, 10, 10,
2197 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
2198 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
2199 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
2200 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
2201 13, 13, 13, 13, 13, 13, 13, 13, 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, 14, 14, 14, 14, 14, 14, 14, 14,
2204 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 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, 15, 15, 15, 15,
2207 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  0,  0, 16, 17,
2208 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
2209 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2210 24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
2211 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
2212 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
2213 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
2214 27, 27, 27, 27, 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, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
2217 28, 28, 28, 28, 28, 28, 28, 28, 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, 29, 29, 29, 29, 29, 29, 29, 29,
2220 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29
2221 };
2222 
2223 const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {
2224  0,  1,  2,  3,  4,  5,  6,  7,  8,  8,  9,  9, 10, 10, 11, 11, 12, 12, 12, 12,
2225 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
2226 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
2227 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
2228 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
2229 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
2230 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2231 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2232 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
2233 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
2234 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
2235 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
2236 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28
2237 };
2238 
2239 local const int base_length[LENGTH_CODES] = {
2240 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
2241 64, 80, 96, 112, 128, 160, 192, 224, 0
2242 };
2243 
2244 local const int base_dist[D_CODES] = {
2245     0,     1,     2,     3,     4,     6,     8,    12,    16,    24,
2246    32,    48,    64,    96,   128,   192,   256,   384,   512,   768,
2247  1024,  1536,  2048,  3072,  4096,  6144,  8192, 12288, 16384, 24576
2248 };
2249 /* --- trees.h */
2250 
2251 #endif /* GEN_TREES_H */
2252 
2253 struct static_tree_desc_s {
2254     const ct_data *static_tree;  /* static tree or NULL */
2255     const intf *extra_bits;      /* extra bits for each code or NULL */
2256     int     extra_base;          /* base index for extra_bits */
2257     int     elems;               /* max number of elements in the tree */
2258     int     max_length;          /* max bit length for the codes */
2259 };
2260 
2261 local static_tree_desc  static_l_desc =
2262 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
2263 
2264 local static_tree_desc  static_d_desc =
2265 {static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};
2266 
2267 local static_tree_desc  static_bl_desc =
2268 {(const ct_data *)0, extra_blbits, 0,   BL_CODES, MAX_BL_BITS};
2269 
2270 /* ===========================================================================
2271  * Local (static) routines in this file.
2272  */
2273 
2274 local void tr_static_init __P((void));
2275 local void init_block     __P((deflate_state *s));
2276 local void pqdownheap     __P((deflate_state *s, ct_data *tree, int k));
2277 local void gen_bitlen     __P((deflate_state *s, tree_desc *desc));
2278 local void gen_codes      __P((ct_data *tree, int max_code, ushf *bl_count));
2279 local void build_tree     __P((deflate_state *s, tree_desc *desc));
2280 local void scan_tree      __P((deflate_state *s, ct_data *tree, int max_code));
2281 local void send_tree      __P((deflate_state *s, ct_data *tree, int max_code));
2282 local int  build_bl_tree  __P((deflate_state *s));
2283 local void send_all_trees __P((deflate_state *s, int lcodes, int dcodes,
2284                               int blcodes));
2285 local void compress_block __P((deflate_state *s, const ct_data *ltree,
2286                               const ct_data *dtree));
2287 local void set_data_type  __P((deflate_state *s));
2288 local unsigned bi_reverse __P((unsigned value, int length));
2289 local void bi_windup      __P((deflate_state *s));
2290 local void bi_flush       __P((deflate_state *s));
2291 local void copy_block     __P((deflate_state *s, charf *buf, unsigned len,
2292                               int header));
2293 
2294 #ifdef GEN_TREES_H
2295 local void gen_trees_header __P((void));
2296 #endif
2297 
2298 #ifndef DEBUG_ZLIB
2299 #  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
2300    /* Send a code of the given tree. c and tree must not have side effects */
2301 
2302 #else /* DEBUG_ZLIB */
2303 #  define send_code(s, c, tree) \
2304      { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
2305        send_bits(s, tree[c].Code, tree[c].Len); }
2306 #endif
2307 
2308 /* ===========================================================================
2309  * Output a short LSB first on the stream.
2310  * IN assertion: there is enough room in pendingBuf.
2311  */
2312 #define put_short(s, w) { \
2313     put_byte(s, (uch)((w) & 0xff)); \
2314     put_byte(s, (uch)((ush)(w) >> 8)); \
2315 }
2316 
2317 /* ===========================================================================
2318  * Send a value on a given number of bits.
2319  * IN assertion: length <= 16 and value fits in length bits.
2320  */
2321 #ifdef DEBUG_ZLIB
2322 local void send_bits      __P((deflate_state *s, int value, int length));
2323 
2324 local void send_bits(s, value, length)
2325     deflate_state *s;
2326     int value;  /* value to send */
2327     int length; /* number of bits */
2328 {
2329     Tracevv((stderr," l %2d v %4x ", length, value));
2330     Assert(length > 0 && length <= 15, "invalid length");
2331     s->bits_sent += (ulg)length;
2332 
2333     /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2334      * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2335      * unused bits in value.
2336      */
2337     if (s->bi_valid > (int)Buf_size - length) {
2338         s->bi_buf |= (value << s->bi_valid);
2339         put_short(s, s->bi_buf);
2340         s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2341         s->bi_valid += length - Buf_size;
2342     } else {
2343         s->bi_buf |= value << s->bi_valid;
2344         s->bi_valid += length;
2345     }
2346 }
2347 #else /* !DEBUG_ZLIB */
2348 
2349 #define send_bits(s, value, length) \
2350 { int len = length;\
2351   if (s->bi_valid > (int)Buf_size - len) {\
2352     int val = value;\
2353     s->bi_buf |= (val << s->bi_valid);\
2354     put_short(s, s->bi_buf);\
2355     s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2356     s->bi_valid += len - Buf_size;\
2357   } else {\
2358     s->bi_buf |= (value) << s->bi_valid;\
2359     s->bi_valid += len;\
2360   }\
2361 }
2362 #endif /* DEBUG_ZLIB */
2363 
2364 
2365 /* ===========================================================================
2366  * Initialize the various 'constant' tables.
2367  */
2368 local void tr_static_init()
2369 {
2370 #if defined(GEN_TREES_H) || !defined(STDC)
2371     static int static_init_done = 0;
2372     int n;        /* iterates over tree elements */
2373     int bits;     /* bit counter */
2374     int length;   /* length value */
2375     int code;     /* code value */
2376     int dist;     /* distance index */
2377     ush bl_count[MAX_BITS+1];
2378     /* number of codes at each bit length for an optimal tree */
2379 
2380     if (static_init_done) return;
2381 
2382     /* For some embedded targets, global variables are not initialized: */
2383     static_l_desc.static_tree = static_ltree;
2384     static_l_desc.extra_bits = extra_lbits;
2385     static_d_desc.static_tree = static_dtree;
2386     static_d_desc.extra_bits = extra_dbits;
2387     static_bl_desc.extra_bits = extra_blbits;
2388 
2389     /* Initialize the mapping length (0..255) -> length code (0..28) */
2390     length = 0;
2391     for (code = 0; code < LENGTH_CODES-1; code++) {
2392         base_length[code] = length;
2393         for (n = 0; n < (1<<extra_lbits[code]); n++) {
2394             _length_code[length++] = (uch)code;
2395         }
2396     }
2397     Assert (length == 256, "tr_static_init: length != 256");
2398     /* Note that the length 255 (match length 258) can be represented
2399      * in two different ways: code 284 + 5 bits or code 285, so we
2400      * overwrite length_code[255] to use the best encoding:
2401      */
2402     _length_code[length-1] = (uch)code;
2403 
2404     /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2405     dist = 0;
2406     for (code = 0 ; code < 16; code++) {
2407         base_dist[code] = dist;
2408         for (n = 0; n < (1<<extra_dbits[code]); n++) {
2409             _dist_code[dist++] = (uch)code;
2410         }
2411     }
2412     Assert (dist == 256, "tr_static_init: dist != 256");
2413     dist >>= 7; /* from now on, all distances are divided by 128 */
2414     for ( ; code < D_CODES; code++) {
2415         base_dist[code] = dist << 7;
2416         for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2417             _dist_code[256 + dist++] = (uch)code;
2418         }
2419     }
2420     Assert (dist == 256, "tr_static_init: 256+dist != 512");
2421 
2422     /* Construct the codes of the static literal tree */
2423     for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2424     n = 0;
2425     while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2426     while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2427     while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2428     while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2429     /* Codes 286 and 287 do not exist, but we must include them in the
2430      * tree construction to get a canonical Huffman tree (longest code
2431      * all ones)
2432      */
2433     gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2434 
2435     /* The static distance tree is trivial: */
2436     for (n = 0; n < D_CODES; n++) {
2437         static_dtree[n].Len = 5;
2438         static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2439     }
2440     static_init_done = 1;
2441 
2442 #  ifdef GEN_TREES_H
2443     gen_trees_header();
2444 #  endif
2445 #endif /* defined(GEN_TREES_H) || !defined(STDC) */
2446 }
2447 
2448 /* ===========================================================================
2449  * Genererate the file trees.h describing the static trees.
2450  */
2451 #ifdef GEN_TREES_H
2452 #  ifndef DEBUG_ZLIB
2453 #    include <stdio.h>
2454 #  endif
2455 
2456 #  define SEPARATOR(i, last, width) \
2457       ((i) == (last)? "\n};\n\n" :    \
2458        ((i) % (width) == (width)-1 ? ",\n" : ", "))
2459 
2460 void gen_trees_header()
2461 {
2462     FILE *header = fopen("trees.h", "w");
2463     int i;
2464 
2465     Assert (header != NULL, "Can't open trees.h");
2466     fprintf(header,
2467 	    "/* header created automatically with -DGEN_TREES_H */\n\n");
2468 
2469     fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
2470     for (i = 0; i < L_CODES+2; i++) {
2471 	fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
2472 		static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
2473     }
2474 
2475     fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
2476     for (i = 0; i < D_CODES; i++) {
2477 	fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
2478 		static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
2479     }
2480 
2481     fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n");
2482     for (i = 0; i < DIST_CODE_LEN; i++) {
2483 	fprintf(header, "%2u%s", _dist_code[i],
2484 		SEPARATOR(i, DIST_CODE_LEN-1, 20));
2485     }
2486 
2487     fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
2488     for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
2489 	fprintf(header, "%2u%s", _length_code[i],
2490 		SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
2491     }
2492 
2493     fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
2494     for (i = 0; i < LENGTH_CODES; i++) {
2495 	fprintf(header, "%1u%s", base_length[i],
2496 		SEPARATOR(i, LENGTH_CODES-1, 20));
2497     }
2498 
2499     fprintf(header, "local const int base_dist[D_CODES] = {\n");
2500     for (i = 0; i < D_CODES; i++) {
2501 	fprintf(header, "%5u%s", base_dist[i],
2502 		SEPARATOR(i, D_CODES-1, 10));
2503     }
2504 
2505     fclose(header);
2506 }
2507 #endif /* GEN_TREES_H */
2508 
2509 /* ===========================================================================
2510  * Initialize the tree data structures for a new zlib stream.
2511  */
2512 void _tr_init(s)
2513     deflate_state *s;
2514 {
2515     tr_static_init();
2516 
2517     s->l_desc.dyn_tree = s->dyn_ltree;
2518     s->l_desc.stat_desc = &static_l_desc;
2519 
2520     s->d_desc.dyn_tree = s->dyn_dtree;
2521     s->d_desc.stat_desc = &static_d_desc;
2522 
2523     s->bl_desc.dyn_tree = s->bl_tree;
2524     s->bl_desc.stat_desc = &static_bl_desc;
2525 
2526     s->bi_buf = 0;
2527     s->bi_valid = 0;
2528     s->last_eob_len = 8; /* enough lookahead for inflate */
2529 #ifdef DEBUG_ZLIB
2530     s->compressed_len = 0L;
2531     s->bits_sent = 0L;
2532 #endif
2533 
2534     /* Initialize the first block of the first file: */
2535     init_block(s);
2536 }
2537 
2538 /* ===========================================================================
2539  * Initialize a new block.
2540  */
2541 local void init_block(s)
2542     deflate_state *s;
2543 {
2544     int n; /* iterates over tree elements */
2545 
2546     /* Initialize the trees. */
2547     for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
2548     for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
2549     for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2550 
2551     s->dyn_ltree[END_BLOCK].Freq = 1;
2552     s->opt_len = s->static_len = 0L;
2553     s->last_lit = s->matches = 0;
2554 }
2555 
2556 #define SMALLEST 1
2557 /* Index within the heap array of least frequent node in the Huffman tree */
2558 
2559 
2560 /* ===========================================================================
2561  * Remove the smallest element from the heap and recreate the heap with
2562  * one less element. Updates heap and heap_len.
2563  */
2564 #define pqremove(s, tree, top) \
2565 {\
2566     top = s->heap[SMALLEST]; \
2567     s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2568     pqdownheap(s, tree, SMALLEST); \
2569 }
2570 
2571 /* ===========================================================================
2572  * Compares to subtrees, using the tree depth as tie breaker when
2573  * the subtrees have equal frequency. This minimizes the worst case length.
2574  */
2575 #define smaller(tree, n, m, depth) \
2576    (tree[n].Freq < tree[m].Freq || \
2577    (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2578 
2579 /* ===========================================================================
2580  * Restore the heap property by moving down the tree starting at node k,
2581  * exchanging a node with the smallest of its two sons if necessary, stopping
2582  * when the heap property is re-established (each father smaller than its
2583  * two sons).
2584  */
2585 local void pqdownheap(s, tree, k)
2586     deflate_state *s;
2587     ct_data *tree;  /* the tree to restore */
2588     int k;               /* node to move down */
2589 {
2590     int v = s->heap[k];
2591     int j = k << 1;  /* left son of k */
2592     while (j <= s->heap_len) {
2593         /* Set j to the smallest of the two sons: */
2594         if (j < s->heap_len &&
2595             smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2596             j++;
2597         }
2598         /* Exit if v is smaller than both sons */
2599         if (smaller(tree, v, s->heap[j], s->depth)) break;
2600 
2601         /* Exchange v with the smallest son */
2602         s->heap[k] = s->heap[j];  k = j;
2603 
2604         /* And continue down the tree, setting j to the left son of k */
2605         j <<= 1;
2606     }
2607     s->heap[k] = v;
2608 }
2609 
2610 /* ===========================================================================
2611  * Compute the optimal bit lengths for a tree and update the total bit length
2612  * for the current block.
2613  * IN assertion: the fields freq and dad are set, heap[heap_max] and
2614  *    above are the tree nodes sorted by increasing frequency.
2615  * OUT assertions: the field len is set to the optimal bit length, the
2616  *     array bl_count contains the frequencies for each bit length.
2617  *     The length opt_len is updated; static_len is also updated if stree is
2618  *     not null.
2619  */
2620 local void gen_bitlen(s, desc)
2621     deflate_state *s;
2622     tree_desc *desc;    /* the tree descriptor */
2623 {
2624     ct_data *tree        = desc->dyn_tree;
2625     int max_code         = desc->max_code;
2626     const ct_data *stree = desc->stat_desc->static_tree;
2627     const intf *extra    = desc->stat_desc->extra_bits;
2628     int base             = desc->stat_desc->extra_base;
2629     int max_length       = desc->stat_desc->max_length;
2630     int h;              /* heap index */
2631     int n, m;           /* iterate over the tree elements */
2632     int bits;           /* bit length */
2633     int xbits;          /* extra bits */
2634     ush f;              /* frequency */
2635     int overflow = 0;   /* number of elements with bit length too large */
2636 
2637     for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2638 
2639     /* In a first pass, compute the optimal bit lengths (which may
2640      * overflow in the case of the bit length tree).
2641      */
2642     tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2643 
2644     for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2645         n = s->heap[h];
2646         bits = tree[tree[n].Dad].Len + 1;
2647         if (bits > max_length) bits = max_length, overflow++;
2648         tree[n].Len = (ush)bits;
2649         /* We overwrite tree[n].Dad which is no longer needed */
2650 
2651         if (n > max_code) continue; /* not a leaf node */
2652 
2653         s->bl_count[bits]++;
2654         xbits = 0;
2655         if (n >= base) xbits = extra[n-base];
2656         f = tree[n].Freq;
2657         s->opt_len += (ulg)f * (bits + xbits);
2658         if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2659     }
2660     if (overflow == 0) return;
2661 
2662     Trace((stderr,"\nbit length overflow\n"));
2663     /* This happens for example on obj2 and pic of the Calgary corpus */
2664 
2665     /* Find the first bit length which could increase: */
2666     do {
2667         bits = max_length-1;
2668         while (s->bl_count[bits] == 0) bits--;
2669         s->bl_count[bits]--;      /* move one leaf down the tree */
2670         s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2671         s->bl_count[max_length]--;
2672         /* The brother of the overflow item also moves one step up,
2673          * but this does not affect bl_count[max_length]
2674          */
2675         overflow -= 2;
2676     } while (overflow > 0);
2677 
2678     /* Now recompute all bit lengths, scanning in increasing frequency.
2679      * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2680      * lengths instead of fixing only the wrong ones. This idea is taken
2681      * from 'ar' written by Haruhiko Okumura.)
2682      */
2683     for (bits = max_length; bits != 0; bits--) {
2684         n = s->bl_count[bits];
2685         while (n != 0) {
2686             m = s->heap[--h];
2687             if (m > max_code) continue;
2688             if (tree[m].Len != (unsigned) bits) {
2689                 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2690                 s->opt_len += ((long)bits - (long)tree[m].Len)
2691                               *(long)tree[m].Freq;
2692                 tree[m].Len = (ush)bits;
2693             }
2694             n--;
2695         }
2696     }
2697 }
2698 
2699 /* ===========================================================================
2700  * Generate the codes for a given tree and bit counts (which need not be
2701  * optimal).
2702  * IN assertion: the array bl_count contains the bit length statistics for
2703  * the given tree and the field len is set for all tree elements.
2704  * OUT assertion: the field code is set for all tree elements of non
2705  *     zero code length.
2706  */
2707 local void gen_codes (tree, max_code, bl_count)
2708     ct_data *tree;             /* the tree to decorate */
2709     int max_code;              /* largest code with non zero frequency */
2710     ushf *bl_count;            /* number of codes at each bit length */
2711 {
2712     ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2713     ush code = 0;              /* running code value */
2714     int bits;                  /* bit index */
2715     int n;                     /* code index */
2716 
2717     /* The distribution counts are first used to generate the code values
2718      * without bit reversal.
2719      */
2720     for (bits = 1; bits <= MAX_BITS; bits++) {
2721         next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2722     }
2723     /* Check that the bit counts in bl_count are consistent. The last code
2724      * must be all ones.
2725      */
2726     Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2727             "inconsistent bit counts");
2728     Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2729 
2730     for (n = 0;  n <= max_code; n++) {
2731         int len = tree[n].Len;
2732         if (len == 0) continue;
2733         /* Now reverse the bits */
2734         tree[n].Code = bi_reverse(next_code[len]++, len);
2735 
2736         Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2737              n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2738     }
2739 }
2740 
2741 /* ===========================================================================
2742  * Construct one Huffman tree and assigns the code bit strings and lengths.
2743  * Update the total bit length for the current block.
2744  * IN assertion: the field freq is set for all tree elements.
2745  * OUT assertions: the fields len and code are set to the optimal bit length
2746  *     and corresponding code. The length opt_len is updated; static_len is
2747  *     also updated if stree is not null. The field max_code is set.
2748  */
2749 local void build_tree(s, desc)
2750     deflate_state *s;
2751     tree_desc *desc; /* the tree descriptor */
2752 {
2753     ct_data *tree         = desc->dyn_tree;
2754     const ct_data *stree  = desc->stat_desc->static_tree;
2755     int elems             = desc->stat_desc->elems;
2756     int n, m;          /* iterate over heap elements */
2757     int max_code = -1; /* largest code with non zero frequency */
2758     int node;          /* new node being created */
2759 
2760     /* Construct the initial heap, with least frequent element in
2761      * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2762      * heap[0] is not used.
2763      */
2764     s->heap_len = 0, s->heap_max = HEAP_SIZE;
2765 
2766     for (n = 0; n < elems; n++) {
2767         if (tree[n].Freq != 0) {
2768             s->heap[++(s->heap_len)] = max_code = n;
2769             s->depth[n] = 0;
2770         } else {
2771             tree[n].Len = 0;
2772         }
2773     }
2774 
2775     /* The pkzip format requires that at least one distance code exists,
2776      * and that at least one bit should be sent even if there is only one
2777      * possible code. So to avoid special checks later on we force at least
2778      * two codes of non zero frequency.
2779      */
2780     while (s->heap_len < 2) {
2781         node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2782         tree[node].Freq = 1;
2783         s->depth[node] = 0;
2784         s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2785         /* node is 0 or 1 so it does not have extra bits */
2786     }
2787     desc->max_code = max_code;
2788 
2789     /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2790      * establish sub-heaps of increasing lengths:
2791      */
2792     for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2793 
2794     /* Construct the Huffman tree by repeatedly combining the least two
2795      * frequent nodes.
2796      */
2797     node = elems;              /* next internal node of the tree */
2798     do {
2799         pqremove(s, tree, n);  /* n = node of least frequency */
2800         m = s->heap[SMALLEST]; /* m = node of next least frequency */
2801 
2802         s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2803         s->heap[--(s->heap_max)] = m;
2804 
2805         /* Create a new node father of n and m */
2806         tree[node].Freq = tree[n].Freq + tree[m].Freq;
2807         s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2808         tree[n].Dad = tree[m].Dad = (ush)node;
2809 #ifdef DUMP_BL_TREE
2810         if (tree == s->bl_tree) {
2811             fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2812                     node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2813         }
2814 #endif
2815         /* and insert the new node in the heap */
2816         s->heap[SMALLEST] = node++;
2817         pqdownheap(s, tree, SMALLEST);
2818 
2819     } while (s->heap_len >= 2);
2820 
2821     s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2822 
2823     /* At this point, the fields freq and dad are set. We can now
2824      * generate the bit lengths.
2825      */
2826     gen_bitlen(s, (tree_desc *)desc);
2827 
2828     /* The field len is now set, we can generate the bit codes */
2829     gen_codes ((ct_data *)tree, max_code, s->bl_count);
2830 }
2831 
2832 /* ===========================================================================
2833  * Scan a literal or distance tree to determine the frequencies of the codes
2834  * in the bit length tree.
2835  */
2836 local void scan_tree (s, tree, max_code)
2837     deflate_state *s;
2838     ct_data *tree;   /* the tree to be scanned */
2839     int max_code;    /* and its largest code of non zero frequency */
2840 {
2841     int n;                     /* iterates over all tree elements */
2842     int prevlen = -1;          /* last emitted length */
2843     int curlen;                /* length of current code */
2844     int nextlen = tree[0].Len; /* length of next code */
2845     int count = 0;             /* repeat count of the current code */
2846     int max_count = 7;         /* max repeat count */
2847     int min_count = 4;         /* min repeat count */
2848 
2849     if (nextlen == 0) max_count = 138, min_count = 3;
2850     tree[max_code+1].Len = (ush)0xffff; /* guard */
2851 
2852     for (n = 0; n <= max_code; n++) {
2853         curlen = nextlen; nextlen = tree[n+1].Len;
2854         if (++count < max_count && curlen == nextlen) {
2855             continue;
2856         } else if (count < min_count) {
2857             s->bl_tree[curlen].Freq += count;
2858         } else if (curlen != 0) {
2859             if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2860             s->bl_tree[REP_3_6].Freq++;
2861         } else if (count <= 10) {
2862             s->bl_tree[REPZ_3_10].Freq++;
2863         } else {
2864             s->bl_tree[REPZ_11_138].Freq++;
2865         }
2866         count = 0; prevlen = curlen;
2867         if (nextlen == 0) {
2868             max_count = 138, min_count = 3;
2869         } else if (curlen == nextlen) {
2870             max_count = 6, min_count = 3;
2871         } else {
2872             max_count = 7, min_count = 4;
2873         }
2874     }
2875 }
2876 
2877 /* ===========================================================================
2878  * Send a literal or distance tree in compressed form, using the codes in
2879  * bl_tree.
2880  */
2881 local void send_tree (s, tree, max_code)
2882     deflate_state *s;
2883     ct_data *tree; /* the tree to be scanned */
2884     int max_code;       /* and its largest code of non zero frequency */
2885 {
2886     int n;                     /* iterates over all tree elements */
2887     int prevlen = -1;          /* last emitted length */
2888     int curlen;                /* length of current code */
2889     int nextlen = tree[0].Len; /* length of next code */
2890     int count = 0;             /* repeat count of the current code */
2891     int max_count = 7;         /* max repeat count */
2892     int min_count = 4;         /* min repeat count */
2893 
2894     /* tree[max_code+1].Len = -1; */  /* guard already set */
2895     if (nextlen == 0) max_count = 138, min_count = 3;
2896 
2897     for (n = 0; n <= max_code; n++) {
2898         curlen = nextlen; nextlen = tree[n+1].Len;
2899         if (++count < max_count && curlen == nextlen) {
2900             continue;
2901         } else if (count < min_count) {
2902             do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2903 
2904         } else if (curlen != 0) {
2905             if (curlen != prevlen) {
2906                 send_code(s, curlen, s->bl_tree); count--;
2907             }
2908             Assert(count >= 3 && count <= 6, " 3_6?");
2909             send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2910 
2911         } else if (count <= 10) {
2912             send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2913 
2914         } else {
2915             send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2916         }
2917         count = 0; prevlen = curlen;
2918         if (nextlen == 0) {
2919             max_count = 138, min_count = 3;
2920         } else if (curlen == nextlen) {
2921             max_count = 6, min_count = 3;
2922         } else {
2923             max_count = 7, min_count = 4;
2924         }
2925     }
2926 }
2927 
2928 /* ===========================================================================
2929  * Construct the Huffman tree for the bit lengths and return the index in
2930  * bl_order of the last bit length code to send.
2931  */
2932 local int build_bl_tree(s)
2933     deflate_state *s;
2934 {
2935     int max_blindex;  /* index of last bit length code of non zero freq */
2936 
2937     /* Determine the bit length frequencies for literal and distance trees */
2938     scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2939     scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2940 
2941     /* Build the bit length tree: */
2942     build_tree(s, (tree_desc *)(&(s->bl_desc)));
2943     /* opt_len now includes the length of the tree representations, except
2944      * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2945      */
2946 
2947     /* Determine the number of bit length codes to send. The pkzip format
2948      * requires that at least 4 bit length codes be sent. (appnote.txt says
2949      * 3 but the actual value used is 4.)
2950      */
2951     for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2952         if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2953     }
2954     /* Update opt_len to include the bit length tree and counts */
2955     s->opt_len += 3*(max_blindex+1) + 5+5+4;
2956     Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2957             s->opt_len, s->static_len));
2958 
2959     return max_blindex;
2960 }
2961 
2962 /* ===========================================================================
2963  * Send the header for a block using dynamic Huffman trees: the counts, the
2964  * lengths of the bit length codes, the literal tree and the distance tree.
2965  * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2966  */
2967 local void send_all_trees(s, lcodes, dcodes, blcodes)
2968     deflate_state *s;
2969     int lcodes, dcodes, blcodes; /* number of codes for each tree */
2970 {
2971     int rank;                    /* index in bl_order */
2972 
2973     Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2974     Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2975             "too many codes");
2976     Tracev((stderr, "\nbl counts: "));
2977     send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2978     send_bits(s, dcodes-1,   5);
2979     send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */
2980     for (rank = 0; rank < blcodes; rank++) {
2981         Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2982         send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2983     }
2984     Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2985 
2986     send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2987     Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2988 
2989     send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2990     Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2991 }
2992 
2993 /* ===========================================================================
2994  * Send a stored block
2995  */
2996 void _tr_stored_block(s, buf, stored_len, eof)
2997     deflate_state *s;
2998     charf *buf;       /* input block */
2999     ulg stored_len;   /* length of input block */
3000     int eof;          /* true if this is the last block for a file */
3001 {
3002     send_bits(s, (STORED_BLOCK<<1)+eof, 3);  /* send block type */
3003 #ifdef DEBUG_ZLIB
3004     s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
3005     s->compressed_len += (stored_len + 4) << 3;
3006 #endif
3007     copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
3008 }
3009 
3010 /* Send just the `stored block' type code without any length bytes or data.
3011  */
3012 void _tr_stored_type_only(s)
3013     deflate_state *s;
3014 {
3015     send_bits(s, (STORED_BLOCK << 1), 3);
3016     bi_windup(s);
3017 #ifdef DEBUG_ZLIB
3018     s->compressed_len = (s->compressed_len + 3) & ~7L;
3019 #endif
3020 }
3021 
3022 /* ===========================================================================
3023  * Send one empty static block to give enough lookahead for inflate.
3024  * This takes 10 bits, of which 7 may remain in the bit buffer.
3025  * The current inflate code requires 9 bits of lookahead. If the
3026  * last two codes for the previous block (real code plus EOB) were coded
3027  * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
3028  * the last real code. In this case we send two empty static blocks instead
3029  * of one. (There are no problems if the previous block is stored or fixed.)
3030  * To simplify the code, we assume the worst case of last real code encoded
3031  * on one bit only.
3032  */
3033 void _tr_align(s)
3034     deflate_state *s;
3035 {
3036     send_bits(s, STATIC_TREES<<1, 3);
3037     send_code(s, END_BLOCK, static_ltree);
3038 #ifdef DEBUG_ZLIB
3039     s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
3040 #endif
3041     bi_flush(s);
3042     /* Of the 10 bits for the empty block, we have already sent
3043      * (10 - bi_valid) bits. The lookahead for the last real code (before
3044      * the EOB of the previous block) was thus at least one plus the length
3045      * of the EOB plus what we have just sent of the empty static block.
3046      */
3047     if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
3048         send_bits(s, STATIC_TREES<<1, 3);
3049         send_code(s, END_BLOCK, static_ltree);
3050 #ifdef DEBUG_ZLIB
3051         s->compressed_len += 10L;
3052 #endif
3053         bi_flush(s);
3054     }
3055     s->last_eob_len = 7;
3056 }
3057 
3058 /* ===========================================================================
3059  * Determine the best encoding for the current block: dynamic trees, static
3060  * trees or store, and output the encoded block to the zip file.
3061  */
3062 void _tr_flush_block(s, buf, stored_len, eof)
3063     deflate_state *s;
3064     charf *buf;       /* input block, or NULL if too old */
3065     ulg stored_len;   /* length of input block */
3066     int eof;          /* true if this is the last block for a file */
3067 {
3068     ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
3069     int max_blindex = 0;  /* index of last bit length code of non zero freq */
3070 
3071     /* Build the Huffman trees unless a stored block is forced */
3072     if (s->level > 0) {
3073 
3074 	 /* Check if the file is ascii or binary */
3075 	if (s->data_type == Z_UNKNOWN) set_data_type(s);
3076 
3077 	/* Construct the literal and distance trees */
3078 	build_tree(s, (tree_desc *)(&(s->l_desc)));
3079 	Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
3080 		s->static_len));
3081 
3082 	build_tree(s, (tree_desc *)(&(s->d_desc)));
3083 	Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
3084 		s->static_len));
3085 	/* At this point, opt_len and static_len are the total bit lengths of
3086 	 * the compressed block data, excluding the tree representations.
3087 	 */
3088 
3089 	/* Build the bit length tree for the above two trees, and get the index
3090 	 * in bl_order of the last bit length code to send.
3091 	 */
3092 	max_blindex = build_bl_tree(s);
3093 
3094 	/* Determine the best encoding. Compute first the block length in bytes*/
3095 	opt_lenb = (s->opt_len+3+7)>>3;
3096 	static_lenb = (s->static_len+3+7)>>3;
3097 
3098 	Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
3099 		opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
3100 		s->last_lit));
3101 
3102 	if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
3103 
3104     } else {
3105         Assert(buf != (char*)0, "lost buf");
3106 	opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
3107     }
3108 
3109 #ifdef FORCE_STORED
3110     if (buf != (char*)0) { /* force stored block */
3111 #else
3112     if (stored_len+4 <= opt_lenb && buf != (char*)0) {
3113                        /* 4: two words for the lengths */
3114 #endif
3115         /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
3116          * Otherwise we can't have processed more than WSIZE input bytes since
3117          * the last block flush, because compression would have been
3118          * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
3119          * transform a block into a stored block.
3120          */
3121         _tr_stored_block(s, buf, stored_len, eof);
3122 
3123 #ifdef FORCE_STATIC
3124     } else if (static_lenb >= 0) { /* force static trees */
3125 #else
3126     } else if (static_lenb == opt_lenb) {
3127 #endif
3128         send_bits(s, (STATIC_TREES<<1)+eof, 3);
3129         compress_block(s, (const ct_data *)static_ltree, (const ct_data *)static_dtree);
3130 #ifdef DEBUG_ZLIB
3131         s->compressed_len += 3 + s->static_len;
3132 #endif
3133     } else {
3134         send_bits(s, (DYN_TREES<<1)+eof, 3);
3135         send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
3136                        max_blindex+1);
3137         compress_block(s, (const ct_data *)s->dyn_ltree, (const ct_data *)s->dyn_dtree);
3138 #ifdef DEBUG_ZLIB
3139         s->compressed_len += 3 + s->opt_len;
3140 #endif
3141     }
3142     Assert (s->compressed_len == s->bits_sent, "bad compressed size");
3143     /* The above check is made mod 2^32, for files larger than 512 MB
3144      * and uLong implemented on 32 bits.
3145      */
3146     init_block(s);
3147 
3148     if (eof) {
3149         bi_windup(s);
3150 #ifdef DEBUG_ZLIB
3151         s->compressed_len += 7;  /* align on byte boundary */
3152 #endif
3153     }
3154     Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
3155            s->compressed_len-7*eof));
3156 }
3157 
3158 /* ===========================================================================
3159  * Save the match info and tally the frequency counts. Return true if
3160  * the current block must be flushed.
3161  */
3162 #if 0
3163 int _tr_tally (s, dist, lc)
3164     deflate_state *s;
3165     unsigned dist;  /* distance of matched string */
3166     unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
3167 {
3168     s->d_buf[s->last_lit] = (ush)dist;
3169     s->l_buf[s->last_lit++] = (uch)lc;
3170     if (dist == 0) {
3171         /* lc is the unmatched char */
3172         s->dyn_ltree[lc].Freq++;
3173     } else {
3174         s->matches++;
3175         /* Here, lc is the match length - MIN_MATCH */
3176         dist--;             /* dist = match distance - 1 */
3177         Assert((ush)dist < (ush)MAX_DIST(s) &&
3178                (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
3179                (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");
3180 
3181         s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
3182         s->dyn_dtree[d_code(dist)].Freq++;
3183     }
3184 
3185 #ifdef TRUNCATE_BLOCK
3186     /* Try to guess if it is profitable to stop the current block here */
3187     if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
3188         /* Compute an upper bound for the compressed length */
3189         ulg out_length = (ulg)s->last_lit*8L;
3190         ulg in_length = (ulg)((long)s->strstart - s->block_start);
3191         int dcode;
3192         for (dcode = 0; dcode < D_CODES; dcode++) {
3193             out_length += (ulg)s->dyn_dtree[dcode].Freq *
3194                 (5L+extra_dbits[dcode]);
3195         }
3196         out_length >>= 3;
3197         Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
3198                s->last_lit, in_length, out_length,
3199                100L - out_length*100L/in_length));
3200         if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
3201     }
3202 #endif
3203     return (s->last_lit == s->lit_bufsize-1);
3204     /* We avoid equality with lit_bufsize because of wraparound at 64K
3205      * on 16 bit machines and because stored blocks are restricted to
3206      * 64K-1 bytes.
3207      */
3208 }
3209 #endif
3210 
3211 /* ===========================================================================
3212  * Send the block data compressed using the given Huffman trees
3213  */
3214 local void compress_block(s, ltree, dtree)
3215     deflate_state *s;
3216     const ct_data *ltree; /* literal tree */
3217     const ct_data *dtree; /* distance tree */
3218 {
3219     unsigned dist;      /* distance of matched string */
3220     int lc;             /* match length or unmatched char (if dist == 0) */
3221     unsigned lx = 0;    /* running index in l_buf */
3222     unsigned code;      /* the code to send */
3223     int extra;          /* number of extra bits to send */
3224 
3225     if (s->last_lit != 0) do {
3226         dist = s->d_buf[lx];
3227         lc = s->l_buf[lx++];
3228         if (dist == 0) {
3229             send_code(s, lc, ltree); /* send a literal byte */
3230             Tracecv(isgraph(lc), (stderr," '%c' ", lc));
3231         } else {
3232             /* Here, lc is the match length - MIN_MATCH */
3233             code = _length_code[lc];
3234             send_code(s, code+LITERALS+1, ltree); /* send the length code */
3235             extra = extra_lbits[code];
3236             if (extra != 0) {
3237                 lc -= base_length[code];
3238                 send_bits(s, lc, extra);       /* send the extra length bits */
3239             }
3240             dist--; /* dist is now the match distance - 1 */
3241             code = d_code(dist);
3242             Assert (code < D_CODES, "bad d_code");
3243 
3244             send_code(s, code, dtree);       /* send the distance code */
3245             extra = extra_dbits[code];
3246             if (extra != 0) {
3247                 dist -= base_dist[code];
3248                 send_bits(s, dist, extra);   /* send the extra distance bits */
3249             }
3250         } /* literal or match pair ? */
3251 
3252         /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
3253         Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
3254 
3255     } while (lx < s->last_lit);
3256 
3257     send_code(s, END_BLOCK, ltree);
3258     s->last_eob_len = ltree[END_BLOCK].Len;
3259 }
3260 
3261 /* ===========================================================================
3262  * Set the data type to ASCII or BINARY, using a crude approximation:
3263  * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
3264  * IN assertion: the fields freq of dyn_ltree are set and the total of all
3265  * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
3266  */
3267 local void set_data_type(s)
3268     deflate_state *s;
3269 {
3270     int n = 0;
3271     unsigned ascii_freq = 0;
3272     unsigned bin_freq = 0;
3273     while (n < 7)        bin_freq += s->dyn_ltree[n++].Freq;
3274     while (n < 128)    ascii_freq += s->dyn_ltree[n++].Freq;
3275     while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
3276     s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
3277 }
3278 
3279 /* ===========================================================================
3280  * Reverse the first len bits of a code, using straightforward code (a faster
3281  * method would use a table)
3282  * IN assertion: 1 <= len <= 15
3283  */
3284 local unsigned bi_reverse(code, len)
3285     unsigned code; /* the value to invert */
3286     int len;       /* its bit length */
3287 {
3288     unsigned res = 0;
3289     do {
3290         res |= code & 1;
3291         code >>= 1, res <<= 1;
3292     } while (--len > 0);
3293     return res >> 1;
3294 }
3295 
3296 /* ===========================================================================
3297  * Flush the bit buffer, keeping at most 7 bits in it.
3298  */
3299 local void bi_flush(s)
3300     deflate_state *s;
3301 {
3302     if (s->bi_valid == 16) {
3303         put_short(s, s->bi_buf);
3304         s->bi_buf = 0;
3305         s->bi_valid = 0;
3306     } else if (s->bi_valid >= 8) {
3307         put_byte(s, (Byte)s->bi_buf);
3308         s->bi_buf >>= 8;
3309         s->bi_valid -= 8;
3310     }
3311 }
3312 
3313 /* ===========================================================================
3314  * Flush the bit buffer and align the output on a byte boundary
3315  */
3316 local void bi_windup(s)
3317     deflate_state *s;
3318 {
3319     if (s->bi_valid > 8) {
3320         put_short(s, s->bi_buf);
3321     } else if (s->bi_valid > 0) {
3322         put_byte(s, (Byte)s->bi_buf);
3323     }
3324     s->bi_buf = 0;
3325     s->bi_valid = 0;
3326 #ifdef DEBUG_ZLIB
3327     s->bits_sent = (s->bits_sent+7) & ~7;
3328 #endif
3329 }
3330 
3331 /* ===========================================================================
3332  * Copy a stored block, storing first the length and its
3333  * one's complement if requested.
3334  */
3335 local void copy_block(s, buf, len, header)
3336     deflate_state *s;
3337     charf    *buf;    /* the input data */
3338     unsigned len;     /* its length */
3339     int      header;  /* true if block header must be written */
3340 {
3341     bi_windup(s);        /* align on byte boundary */
3342     s->last_eob_len = 8; /* enough lookahead for inflate */
3343 
3344     if (header) {
3345         put_short(s, (ush)len);
3346         put_short(s, (ush)~len);
3347 #ifdef DEBUG_ZLIB
3348         s->bits_sent += 2*16;
3349 #endif
3350     }
3351 #ifdef DEBUG_ZLIB
3352     s->bits_sent += (ulg)len<<3;
3353 #endif
3354     /* bundle up the put_byte(s, *buf++) calls */
3355     zmemcpy(&s->pending_buf[s->pending], buf, len);
3356     s->pending += len;
3357 }
3358 /* --- trees.c */
3359 
3360 /* +++ inflate.c */
3361 
3362 /* inflate.c -- zlib interface to inflate modules
3363  * Copyright (C) 1995-2002 Mark Adler
3364  * For conditions of distribution and use, see copyright notice in zlib.h
3365  */
3366 
3367 /* #include "zutil.h" */
3368 
3369 /* +++ infblock.h */
3370 
3371 /* infblock.h -- header to use infblock.c
3372  * Copyright (C) 1995-2002 Mark Adler
3373  * For conditions of distribution and use, see copyright notice in zlib.h
3374  */
3375 
3376 /* WARNING: this file should *not* be used by applications. It is
3377    part of the implementation of the compression library and is
3378    subject to change. Applications should only use zlib.h.
3379  */
3380 
3381 struct inflate_blocks_state;
3382 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3383 
3384 extern inflate_blocks_statef * inflate_blocks_new __P((
3385     z_streamp z,
3386     check_func c,               /* check function */
3387     uInt w));                   /* window size */
3388 
3389 extern int inflate_blocks __P((
3390     inflate_blocks_statef *,
3391     z_streamp ,
3392     int));                      /* initial return code */
3393 
3394 extern void inflate_blocks_reset __P((
3395     inflate_blocks_statef *,
3396     z_streamp ,
3397     uLongf *));                  /* check value on output */
3398 
3399 extern int inflate_blocks_free __P((
3400     inflate_blocks_statef *,
3401     z_streamp));
3402 
3403 extern void inflate_set_dictionary __P((
3404     inflate_blocks_statef *s,
3405     const Bytef *d,  /* dictionary */
3406     uInt  n));       /* dictionary length */
3407 
3408 extern int inflate_blocks_sync_point __P((
3409     inflate_blocks_statef *s));
3410 extern int inflate_addhistory __P((
3411     inflate_blocks_statef *,
3412     z_streamp));
3413 
3414 extern int inflate_packet_flush __P((
3415     inflate_blocks_statef *));
3416 
3417 /* --- infblock.h */
3418 
3419 #ifndef NO_DUMMY_DECL
3420 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3421 #endif
3422 
3423 typedef enum {
3424       METHOD,   /* waiting for method byte */
3425       FLAG,     /* waiting for flag byte */
3426       DICT4,    /* four dictionary check bytes to go */
3427       DICT3,    /* three dictionary check bytes to go */
3428       DICT2,    /* two dictionary check bytes to go */
3429       DICT1,    /* one dictionary check byte to go */
3430       DICT0,    /* waiting for inflateSetDictionary */
3431       BLOCKS,   /* decompressing blocks */
3432       CHECK4,   /* four check bytes to go */
3433       CHECK3,   /* three check bytes to go */
3434       CHECK2,   /* two check bytes to go */
3435       CHECK1,   /* one check byte to go */
3436       DONE,     /* finished check, done */
3437       BAD}      /* got an error--stay here */
3438 inflate_mode;
3439 
3440 /* inflate private state */
3441 struct internal_state {
3442 
3443   /* mode */
3444   inflate_mode  mode;   /* current inflate mode */
3445 
3446   /* mode dependent information */
3447   union {
3448     uInt method;        /* if FLAGS, method byte */
3449     struct {
3450       uLong was;                /* computed check value */
3451       uLong need;               /* stream check value */
3452     } check;            /* if CHECK, check values to compare */
3453     uInt marker;        /* if BAD, inflateSync's marker bytes count */
3454   } sub;        /* submode */
3455 
3456   /* mode independent information */
3457   int  nowrap;          /* flag for no wrapper */
3458   uInt wbits;           /* log2(window size)  (8..15, defaults to 15) */
3459   inflate_blocks_statef
3460     *blocks;            /* current inflate_blocks state */
3461 
3462 };
3463 
3464 
3465 int ZEXPORT inflateReset(z)
3466 z_streamp z;
3467 {
3468   if (z == Z_NULL || z->state == Z_NULL)
3469     return Z_STREAM_ERROR;
3470   z->total_in = z->total_out = 0;
3471   z->msg = Z_NULL;
3472   z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3473   inflate_blocks_reset(z->state->blocks, z, Z_NULL);
3474   Tracev((stderr, "inflate: reset\n"));
3475   return Z_OK;
3476 }
3477 
3478 
3479 int ZEXPORT inflateEnd(z)
3480 z_streamp z;
3481 {
3482   if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3483     return Z_STREAM_ERROR;
3484   if (z->state->blocks != Z_NULL)
3485     inflate_blocks_free(z->state->blocks, z);
3486   ZFREE(z, z->state);
3487   z->state = Z_NULL;
3488   Tracev((stderr, "inflate: end\n"));
3489   return Z_OK;
3490 }
3491 
3492 
3493 int ZEXPORT inflateInit2_(z, w, vers, stream_size)
3494 z_streamp z;
3495 int w;
3496 const char *vers;
3497 int stream_size;
3498 {
3499   if (vers == Z_NULL || vers[0] != ZLIB_VERSION[0] ||
3500       stream_size != sizeof(z_stream))
3501       return Z_VERSION_ERROR;
3502 
3503   /* initialize state */
3504   if (z == Z_NULL)
3505     return Z_STREAM_ERROR;
3506   z->msg = Z_NULL;
3507 #ifndef NO_ZCFUNCS
3508   if (z->zalloc == Z_NULL)
3509   {
3510     z->zalloc = zcalloc;
3511     z->opaque = (voidpf)0;
3512   }
3513   if (z->zfree == Z_NULL) z->zfree = zcfree;
3514 #endif
3515   if ((z->state = (struct internal_state FAR *)
3516        ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3517     return Z_MEM_ERROR;
3518   z->state->blocks = Z_NULL;
3519 
3520   /* handle undocumented nowrap option (no zlib header or check) */
3521   z->state->nowrap = 0;
3522   if (w < 0)
3523   {
3524     w = - w;
3525     z->state->nowrap = 1;
3526   }
3527 
3528   /* set window size */
3529   if (w < 8 || w > 15)
3530   {
3531     inflateEnd(z);
3532     return Z_STREAM_ERROR;
3533   }
3534   z->state->wbits = (uInt)w;
3535 
3536   /* create inflate_blocks state */
3537   if ((z->state->blocks =
3538       inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3539       == Z_NULL)
3540   {
3541     inflateEnd(z);
3542     return Z_MEM_ERROR;
3543   }
3544   Tracev((stderr, "inflate: allocated\n"));
3545 
3546   /* reset state */
3547   inflateReset(z);
3548   return Z_OK;
3549 }
3550 
3551 
3552 #if 0
3553 int ZEXPORT inflateInit_(z, vers, stream_size)
3554 z_streamp z;
3555 const char *vers;
3556 int stream_size;
3557 {
3558   return inflateInit2_(z, DEF_WBITS, vers, stream_size);
3559 }
3560 #endif
3561 
3562 
3563 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3564 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3565 
3566 int ZEXPORT inflate(z, f)
3567 z_streamp z;
3568 int f;
3569 {
3570   int r, r2;
3571   uInt b;
3572 
3573   if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
3574     return Z_STREAM_ERROR;
3575   r2 = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
3576   r = Z_BUF_ERROR;
3577   while (1) switch (z->state->mode)
3578   {
3579     case METHOD:
3580       NEEDBYTE
3581       if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3582       {
3583         z->state->mode = BAD;
3584         z->msg = "unknown compression method";
3585         z->state->sub.marker = 5;       /* can't try inflateSync */
3586         break;
3587       }
3588       if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3589       {
3590         z->state->mode = BAD;
3591         z->msg = "invalid window size";
3592         z->state->sub.marker = 5;       /* can't try inflateSync */
3593         break;
3594       }
3595       z->state->mode = FLAG;
3596     case FLAG:
3597       NEEDBYTE
3598       b = NEXTBYTE;
3599       if (((z->state->sub.method << 8) + b) % 31)
3600       {
3601         z->state->mode = BAD;
3602         z->msg = "incorrect header check";
3603         z->state->sub.marker = 5;       /* can't try inflateSync */
3604         break;
3605       }
3606       Tracev((stderr, "inflate: zlib header ok\n"));
3607       if (!(b & PRESET_DICT))
3608       {
3609         z->state->mode = BLOCKS;
3610         break;
3611       }
3612       z->state->mode = DICT4;
3613     case DICT4:
3614       NEEDBYTE
3615       z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3616       z->state->mode = DICT3;
3617     case DICT3:
3618       NEEDBYTE
3619       z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3620       z->state->mode = DICT2;
3621     case DICT2:
3622       NEEDBYTE
3623       z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3624       z->state->mode = DICT1;
3625     case DICT1:
3626       NEEDBYTE
3627       z->state->sub.check.need += (uLong)NEXTBYTE;
3628       z->adler = z->state->sub.check.need;
3629       z->state->mode = DICT0;
3630       return Z_NEED_DICT;
3631     case DICT0:
3632       z->state->mode = BAD;
3633       z->msg = "need dictionary";
3634       z->state->sub.marker = 0;       /* can try inflateSync */
3635       return Z_STREAM_ERROR;
3636     case BLOCKS:
3637       r = inflate_blocks(z->state->blocks, z, r);
3638       if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3639          r = inflate_packet_flush(z->state->blocks);
3640       if (r == Z_DATA_ERROR)
3641       {
3642         z->state->mode = BAD;
3643         z->state->sub.marker = 0;       /* can try inflateSync */
3644         break;
3645       }
3646       if (r == Z_OK)
3647         r = r2;
3648       if (r != Z_STREAM_END)
3649         return r;
3650       r = r2;
3651       inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3652       if (z->state->nowrap)
3653       {
3654         z->state->mode = DONE;
3655         break;
3656       }
3657       z->state->mode = CHECK4;
3658     case CHECK4:
3659       NEEDBYTE
3660       z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3661       z->state->mode = CHECK3;
3662     case CHECK3:
3663       NEEDBYTE
3664       z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3665       z->state->mode = CHECK2;
3666     case CHECK2:
3667       NEEDBYTE
3668       z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3669       z->state->mode = CHECK1;
3670     case CHECK1:
3671       NEEDBYTE
3672       z->state->sub.check.need += (uLong)NEXTBYTE;
3673 
3674       if (z->state->sub.check.was != z->state->sub.check.need)
3675       {
3676         z->state->mode = BAD;
3677         z->msg = "incorrect data check";
3678         z->state->sub.marker = 5;       /* can't try inflateSync */
3679         break;
3680       }
3681       Tracev((stderr, "inflate: zlib check ok\n"));
3682       z->state->mode = DONE;
3683     case DONE:
3684       return Z_STREAM_END;
3685     case BAD:
3686       return Z_DATA_ERROR;
3687     default:
3688       return Z_STREAM_ERROR;
3689   }
3690  empty:
3691   if (f != Z_PACKET_FLUSH)
3692     return r;
3693   z->state->mode = BAD;
3694   z->msg = "need more for packet flush";
3695   z->state->sub.marker = 0;
3696   return Z_DATA_ERROR;
3697 }
3698 
3699 
3700 #if 0
3701 int ZEXPORT inflateSetDictionary(z, dictionary, dictLength)
3702 z_streamp z;
3703 const Bytef *dictionary;
3704 uInt  dictLength;
3705 {
3706   uInt length = dictLength;
3707 
3708   if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3709     return Z_STREAM_ERROR;
3710 
3711   if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3712   z->adler = 1L;
3713 
3714   if (length >= ((uInt)1<<z->state->wbits))
3715   {
3716     length = (1<<z->state->wbits)-1;
3717     dictionary += dictLength - length;
3718   }
3719   inflate_set_dictionary(z->state->blocks, dictionary, length);
3720   z->state->mode = BLOCKS;
3721   return Z_OK;
3722 }
3723 #endif
3724 
3725 /*
3726  * This subroutine adds the data at next_in/avail_in to the output history
3727  * without performing any output.  The output buffer must be "caught up";
3728  * i.e. no pending output (hence s->read equals s->write), and the state must
3729  * be BLOCKS (i.e. we should be willing to see the start of a series of
3730  * BLOCKS).  On exit, the output will also be caught up, and the checksum
3731  * will have been updated if need be.
3732  */
3733 
3734 int inflateIncomp(z)
3735 z_stream *z;
3736 {
3737     if (z->state->mode != BLOCKS)
3738 	return Z_DATA_ERROR;
3739     return inflate_addhistory(z->state->blocks, z);
3740 }
3741 
3742 #if 0
3743 int ZEXPORT inflateSync(z)
3744 z_streamp z;
3745 {
3746   uInt n;       /* number of bytes to look at */
3747   Bytef *p;     /* pointer to bytes */
3748   uInt m;       /* number of marker bytes found in a row */
3749   uLong r, w;   /* temporaries to save total_in and total_out */
3750 
3751   /* set up */
3752   if (z == Z_NULL || z->state == Z_NULL)
3753     return Z_STREAM_ERROR;
3754   if (z->state->mode != BAD)
3755   {
3756     z->state->mode = BAD;
3757     z->state->sub.marker = 0;
3758   }
3759   if ((n = z->avail_in) == 0)
3760     return Z_BUF_ERROR;
3761   p = z->next_in;
3762   m = z->state->sub.marker;
3763 
3764   /* search */
3765   while (n && m < 4)
3766   {
3767     static const Byte mark[4] = {0, 0, 0xff, 0xff};
3768     if (*p == mark[m])
3769       m++;
3770     else if (*p)
3771       m = 0;
3772     else
3773       m = 4 - m;
3774     p++, n--;
3775   }
3776 
3777   /* restore */
3778   z->total_in += p - z->next_in;
3779   z->next_in = p;
3780   z->avail_in = n;
3781   z->state->sub.marker = m;
3782 
3783   /* return no joy or set up to restart on a new block */
3784   if (m != 4)
3785     return Z_DATA_ERROR;
3786   r = z->total_in;  w = z->total_out;
3787   inflateReset(z);
3788   z->total_in = r;  z->total_out = w;
3789   z->state->mode = BLOCKS;
3790   return Z_OK;
3791 }
3792 #endif
3793 
3794 
3795 /* Returns true if inflate is currently at the end of a block generated
3796  * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
3797  * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
3798  * but removes the length bytes of the resulting empty stored block. When
3799  * decompressing, PPP checks that at the end of input packet, inflate is
3800  * waiting for these length bytes.
3801  */
3802 #if 0
3803 int ZEXPORT inflateSyncPoint(z)
3804 z_streamp z;
3805 {
3806   if (z == Z_NULL || z->state == Z_NULL || z->state->blocks == Z_NULL)
3807     return Z_STREAM_ERROR;
3808   return inflate_blocks_sync_point(z->state->blocks);
3809 }
3810 #endif
3811 #undef NEEDBYTE
3812 #undef NEXTBYTE
3813 /* --- inflate.c */
3814 
3815 /* +++ infblock.c */
3816 
3817 /* infblock.c -- interpret and process block types to last block
3818  * Copyright (C) 1995-2002 Mark Adler
3819  * For conditions of distribution and use, see copyright notice in zlib.h
3820  */
3821 
3822 /* #include "zutil.h" */
3823 /* #include "infblock.h" */
3824 
3825 /* +++ inftrees.h */
3826 
3827 /* inftrees.h -- header to use inftrees.c
3828  * Copyright (C) 1995-2002 Mark Adler
3829  * For conditions of distribution and use, see copyright notice in zlib.h
3830  */
3831 
3832 /* WARNING: this file should *not* be used by applications. It is
3833    part of the implementation of the compression library and is
3834    subject to change. Applications should only use zlib.h.
3835  */
3836 
3837 /* Huffman code lookup table entry--this entry is four bytes for machines
3838    that have 16-bit pointers (e.g. PC's in the small or medium model). */
3839 
3840 typedef struct inflate_huft_s FAR inflate_huft;
3841 
3842 struct inflate_huft_s {
3843   union {
3844     struct {
3845       Byte Exop;        /* number of extra bits or operation */
3846       Byte Bits;        /* number of bits in this code or subcode */
3847     } what;
3848     uInt pad;           /* pad structure to a power of 2 (4 bytes for */
3849   } word;               /*  16-bit, 8 bytes for 32-bit int's) */
3850   uInt base;            /* literal, length base, distance base,
3851                            or table offset */
3852 };
3853 
3854 /* Maximum size of dynamic tree.  The maximum found in a long but non-
3855    exhaustive search was 1004 huft structures (850 for length/literals
3856    and 154 for distances, the latter actually the result of an
3857    exhaustive search).  The actual maximum is not known, but the
3858    value below is more than safe. */
3859 #define MANY 1440
3860 
3861 extern int inflate_trees_bits __P((
3862     uIntf *,                    /* 19 code lengths */
3863     uIntf *,                    /* bits tree desired/actual depth */
3864     inflate_huft * FAR *,       /* bits tree result */
3865     inflate_huft *,             /* space for trees */
3866     z_streamp));                /* for messages */
3867 
3868 extern int inflate_trees_dynamic __P((
3869     uInt,                       /* number of literal/length codes */
3870     uInt,                       /* number of distance codes */
3871     uIntf *,                    /* that many (total) code lengths */
3872     uIntf *,                    /* literal desired/actual bit depth */
3873     uIntf *,                    /* distance desired/actual bit depth */
3874     inflate_huft * FAR *,       /* literal/length tree result */
3875     inflate_huft * FAR *,       /* distance tree result */
3876     inflate_huft *,             /* space for trees */
3877     z_streamp));                /* for messages */
3878 
3879 extern int inflate_trees_fixed __P((
3880     uIntf *,                    /* literal desired/actual bit depth */
3881     uIntf *,                    /* distance desired/actual bit depth */
3882     inflate_huft * FAR *,       /* literal/length tree result */
3883     inflate_huft * FAR *,       /* distance tree result */
3884     z_streamp));                /* for memory allocation */
3885 /* --- inftrees.h */
3886 
3887 /* +++ infcodes.h */
3888 
3889 /* infcodes.h -- header to use infcodes.c
3890  * Copyright (C) 1995-2002 Mark Adler
3891  * For conditions of distribution and use, see copyright notice in zlib.h
3892  */
3893 
3894 /* WARNING: this file should *not* be used by applications. It is
3895    part of the implementation of the compression library and is
3896    subject to change. Applications should only use zlib.h.
3897  */
3898 
3899 struct inflate_codes_state;
3900 typedef struct inflate_codes_state FAR inflate_codes_statef;
3901 
3902 extern inflate_codes_statef *inflate_codes_new __P((
3903     uInt, uInt,
3904     inflate_huft *, inflate_huft *,
3905     z_streamp ));
3906 
3907 extern int inflate_codes __P((
3908     inflate_blocks_statef *,
3909     z_streamp ,
3910     int));
3911 
3912 extern void inflate_codes_free __P((
3913     inflate_codes_statef *,
3914     z_streamp ));
3915 
3916 /* --- infcodes.h */
3917 
3918 /* +++ infutil.h */
3919 
3920 /* infutil.h -- types and macros common to blocks and codes
3921  * Copyright (C) 1995-2002 Mark Adler
3922  * For conditions of distribution and use, see copyright notice in zlib.h
3923  */
3924 
3925 /* WARNING: this file should *not* be used by applications. It is
3926    part of the implementation of the compression library and is
3927    subject to change. Applications should only use zlib.h.
3928  */
3929 
3930 #ifndef _INFUTIL_H
3931 #define _INFUTIL_H
3932 
3933 typedef enum {
3934       TYPE,     /* get type bits (3, including end bit) */
3935       LENS,     /* get lengths for stored */
3936       STORED,   /* processing stored block */
3937       TABLE,    /* get table lengths */
3938       BTREE,    /* get bit lengths tree for a dynamic block */
3939       DTREE,    /* get length, distance trees for a dynamic block */
3940       CODES,    /* processing fixed or dynamic block */
3941       DRY,      /* output remaining window bytes */
3942       DONEB,    /* finished last block, done */
3943       BADB}     /* got a data error--stuck here */
3944 inflate_block_mode;
3945 
3946 /* inflate blocks semi-private state */
3947 struct inflate_blocks_state {
3948 
3949   /* mode */
3950   inflate_block_mode  mode;     /* current inflate_block mode */
3951 
3952   /* mode dependent information */
3953   union {
3954     uInt left;          /* if STORED, bytes left to copy */
3955     struct {
3956       uInt table;               /* table lengths (14 bits) */
3957       uInt index;               /* index into blens (or border) */
3958       uIntf *blens;             /* bit lengths of codes */
3959       uInt bb;                  /* bit length tree depth */
3960       inflate_huft *tb;         /* bit length decoding tree */
3961     } trees;            /* if DTREE, decoding info for trees */
3962     struct {
3963       inflate_codes_statef
3964          *codes;
3965     } decode;           /* if CODES, current state */
3966   } sub;                /* submode */
3967   uInt last;            /* true if this block is the last block */
3968 
3969   /* mode independent information */
3970   uInt bitk;            /* bits in bit buffer */
3971   uLong bitb;           /* bit buffer */
3972   inflate_huft *hufts;  /* single malloc for tree space */
3973   Bytef *window;        /* sliding window */
3974   Bytef *end;           /* one byte after sliding window */
3975   Bytef *read;          /* window read pointer */
3976   Bytef *write;         /* window write pointer */
3977   check_func checkfn;   /* check function */
3978   uLong check;          /* check on output */
3979 
3980 };
3981 
3982 
3983 /* defines for inflate input/output */
3984 /*   update pointers and return */
3985 #define UPDBITS {s->bitb=b;s->bitk=k;}
3986 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3987 #define UPDOUT {s->write=q;}
3988 #define UPDATE {UPDBITS UPDIN UPDOUT}
3989 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3990 /*   get bytes and bits */
3991 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3992 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3993 #define NEXTBYTE (n--,*p++)
3994 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3995 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3996 /*   output bytes */
3997 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3998 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3999 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
4000 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
4001 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
4002 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
4003 /*   load local pointers */
4004 #define LOAD {LOADIN LOADOUT}
4005 
4006 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
4007 extern uInt inflate_mask[17];
4008 
4009 /* copy as much as possible from the sliding window to the output area */
4010 extern int inflate_flush __P((
4011     inflate_blocks_statef *,
4012     z_streamp ,
4013     int));
4014 
4015 #ifndef NO_DUMMY_DECL
4016 struct internal_state      {int dummy;}; /* for buggy compilers */
4017 #endif
4018 
4019 #endif
4020 /* --- infutil.h */
4021 
4022 #ifndef NO_DUMMY_DECL
4023 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4024 #endif
4025 
4026 /* simplify the use of the inflate_huft type with some defines */
4027 #define exop word.what.Exop
4028 #define bits word.what.Bits
4029 
4030 /* Table for deflate from PKZIP's appnote.txt. */
4031 local const uInt border[] = { /* Order of the bit length code lengths */
4032         16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
4033 
4034 /*
4035    Notes beyond the 1.93a appnote.txt:
4036 
4037    1. Distance pointers never point before the beginning of the output
4038       stream.
4039    2. Distance pointers can point back across blocks, up to 32k away.
4040    3. There is an implied maximum of 7 bits for the bit length table and
4041       15 bits for the actual data.
4042    4. If only one code exists, then it is encoded using one bit.  (Zero
4043       would be more efficient, but perhaps a little confusing.)  If two
4044       codes exist, they are coded using one bit each (0 and 1).
4045    5. There is no way of sending zero distance codes--a dummy must be
4046       sent if there are none.  (History: a pre 2.0 version of PKZIP would
4047       store blocks with no distance codes, but this was discovered to be
4048       too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow
4049       zero distance codes, which is sent as one code of zero bits in
4050       length.
4051    6. There are up to 286 literal/length codes.  Code 256 represents the
4052       end-of-block.  Note however that the static length tree defines
4053       288 codes just to fill out the Huffman codes.  Codes 286 and 287
4054       cannot be used though, since there is no length base or extra bits
4055       defined for them.  Similarily, there are up to 30 distance codes.
4056       However, static trees define 32 codes (all 5 bits) to fill out the
4057       Huffman codes, but the last two had better not show up in the data.
4058    7. Unzip can check dynamic Huffman blocks for complete code sets.
4059       The exception is that a single code would not be complete (see #4).
4060    8. The five bits following the block type is really the number of
4061       literal codes sent minus 257.
4062    9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
4063       (1+6+6).  Therefore, to output three times the length, you output
4064       three codes (1+1+1), whereas to output four times the same length,
4065       you only need two codes (1+3).  Hmm.
4066   10. In the tree reconstruction algorithm, Code = Code + Increment
4067       only if BitLength(i) is not zero.  (Pretty obvious.)
4068   11. Correction: 4 Bits: # of Bit Length codes - 4     (4 - 19)
4069   12. Note: length code 284 can represent 227-258, but length code 285
4070       really is 258.  The last length deserves its own, short code
4071       since it gets used a lot in very redundant files.  The length
4072       258 is special since 258 - 3 (the min match length) is 255.
4073   13. The literal/length and distance code bit lengths are read as a
4074       single stream of lengths.  It is possible (and advantageous) for
4075       a repeat code (16, 17, or 18) to go across the boundary between
4076       the two sets of lengths.
4077  */
4078 
4079 
4080 void inflate_blocks_reset(s, z, c)
4081 inflate_blocks_statef *s;
4082 z_streamp z;
4083 uLongf *c;
4084 {
4085   if (c != Z_NULL)
4086     *c = s->check;
4087   if (s->mode == BTREE || s->mode == DTREE)
4088     ZFREE(z, s->sub.trees.blens);
4089   if (s->mode == CODES)
4090     inflate_codes_free(s->sub.decode.codes, z);
4091   s->mode = TYPE;
4092   s->bitk = 0;
4093   s->bitb = 0;
4094   s->read = s->write = s->window;
4095   if (s->checkfn != Z_NULL)
4096     z->adler = s->check = (*s->checkfn)(0L, (const Bytef *)Z_NULL, 0);
4097   Tracev((stderr, "inflate:   blocks reset\n"));
4098 }
4099 
4100 
4101 inflate_blocks_statef *inflate_blocks_new(z, c, w)
4102 z_streamp z;
4103 check_func c;
4104 uInt w;
4105 {
4106   inflate_blocks_statef *s;
4107 
4108   if ((s = (inflate_blocks_statef *)ZALLOC
4109        (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
4110     return s;
4111   if ((s->hufts =
4112        (inflate_huft *)ZALLOC(z, sizeof(inflate_huft), MANY)) == Z_NULL)
4113   {
4114     ZFREE(z, s);
4115     return Z_NULL;
4116   }
4117   if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
4118   {
4119     ZFREE(z, s->hufts);
4120     ZFREE(z, s);
4121     return Z_NULL;
4122   }
4123   s->end = s->window + w;
4124   s->checkfn = c;
4125   s->mode = TYPE;
4126   Tracev((stderr, "inflate:   blocks allocated\n"));
4127   inflate_blocks_reset(s, z, Z_NULL);
4128   return s;
4129 }
4130 
4131 
4132 int inflate_blocks(s, z, r)
4133 inflate_blocks_statef *s;
4134 z_streamp z;
4135 int r;
4136 {
4137   uInt t;               /* temporary storage */
4138   uLong b;              /* bit buffer */
4139   uInt k;               /* bits in bit buffer */
4140   Bytef *p;             /* input data pointer */
4141   uInt n;               /* bytes available there */
4142   Bytef *q;             /* output window write pointer */
4143   uInt m;               /* bytes to end of window or read pointer */
4144 
4145   /* copy input/output information to locals (UPDATE macro restores) */
4146   LOAD
4147 
4148   /* process input based on current state */
4149   while (1) switch (s->mode)
4150   {
4151     case TYPE:
4152       NEEDBITS(3)
4153       t = (uInt)b & 7;
4154       s->last = t & 1;
4155       switch (t >> 1)
4156       {
4157         case 0:                         /* stored */
4158           Tracev((stderr, "inflate:     stored block%s\n",
4159                  s->last ? " (last)" : ""));
4160           DUMPBITS(3)
4161           t = k & 7;                    /* go to byte boundary */
4162           DUMPBITS(t)
4163           s->mode = LENS;               /* get length of stored block */
4164           break;
4165         case 1:                         /* fixed */
4166           Tracev((stderr, "inflate:     fixed codes block%s\n",
4167                  s->last ? " (last)" : ""));
4168           {
4169             uInt bl, bd;
4170             inflate_huft *tl, *td;
4171 
4172             inflate_trees_fixed(&bl, &bd, &tl, &td, z);
4173             s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
4174             if (s->sub.decode.codes == Z_NULL)
4175             {
4176               r = Z_MEM_ERROR;
4177               LEAVE
4178             }
4179           }
4180           DUMPBITS(3)
4181           s->mode = CODES;
4182           break;
4183         case 2:                         /* dynamic */
4184           Tracev((stderr, "inflate:     dynamic codes block%s\n",
4185                  s->last ? " (last)" : ""));
4186           DUMPBITS(3)
4187           s->mode = TABLE;
4188           break;
4189         case 3:                         /* illegal */
4190           DUMPBITS(3)
4191           s->mode = BADB;
4192           z->msg = "invalid block type";
4193           r = Z_DATA_ERROR;
4194           LEAVE
4195       }
4196       break;
4197     case LENS:
4198       NEEDBITS(32)
4199       if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
4200       {
4201         s->mode = BADB;
4202         z->msg = "invalid stored block lengths";
4203         r = Z_DATA_ERROR;
4204         LEAVE
4205       }
4206       s->sub.left = (uInt)b & 0xffff;
4207       b = k = 0;                      /* dump bits */
4208       Tracev((stderr, "inflate:       stored length %u\n", s->sub.left));
4209       s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
4210       break;
4211     case STORED:
4212       if (n == 0)
4213         LEAVE
4214       NEEDOUT
4215       t = s->sub.left;
4216       if (t > n) t = n;
4217       if (t > m) t = m;
4218       zmemcpy(q, p, t);
4219       p += t;  n -= t;
4220       q += t;  m -= t;
4221       if ((s->sub.left -= t) != 0)
4222         break;
4223       Tracev((stderr, "inflate:       stored end, %lu total out\n",
4224               z->total_out + (q >= s->read ? q - s->read :
4225               (s->end - s->read) + (q - s->window))));
4226       s->mode = s->last ? DRY : TYPE;
4227       break;
4228     case TABLE:
4229       NEEDBITS(14)
4230       s->sub.trees.table = t = (uInt)b & 0x3fff;
4231 #ifndef PKZIP_BUG_WORKAROUND
4232       if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
4233       {
4234         s->mode = BADB;
4235         z->msg = "too many length or distance symbols";
4236         r = Z_DATA_ERROR;
4237         LEAVE
4238       }
4239 #endif
4240       t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
4241       if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
4242       {
4243         r = Z_MEM_ERROR;
4244         LEAVE
4245       }
4246       DUMPBITS(14)
4247       s->sub.trees.index = 0;
4248       Tracev((stderr, "inflate:       table sizes ok\n"));
4249       s->mode = BTREE;
4250     case BTREE:
4251       while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
4252       {
4253         NEEDBITS(3)
4254         s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
4255         DUMPBITS(3)
4256       }
4257       while (s->sub.trees.index < 19)
4258         s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
4259       s->sub.trees.bb = 7;
4260       t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
4261                              &s->sub.trees.tb, s->hufts, z);
4262       if (t != Z_OK)
4263       {
4264         r = t;
4265         if (r == Z_DATA_ERROR)
4266         {
4267           ZFREE(z, s->sub.trees.blens);
4268           s->mode = BADB;
4269         }
4270         LEAVE
4271       }
4272       s->sub.trees.index = 0;
4273       Tracev((stderr, "inflate:       bits tree ok\n"));
4274       s->mode = DTREE;
4275     case DTREE:
4276       while (t = s->sub.trees.table,
4277              s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
4278       {
4279         inflate_huft *h;
4280         uInt i, j, c;
4281 
4282         t = s->sub.trees.bb;
4283         NEEDBITS(t)
4284         h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
4285         t = h->bits;
4286         c = h->base;
4287         if (c < 16)
4288         {
4289           DUMPBITS(t)
4290           s->sub.trees.blens[s->sub.trees.index++] = c;
4291         }
4292         else /* c == 16..18 */
4293         {
4294           i = c == 18 ? 7 : c - 14;
4295           j = c == 18 ? 11 : 3;
4296           NEEDBITS(t + i)
4297           DUMPBITS(t)
4298           j += (uInt)b & inflate_mask[i];
4299           DUMPBITS(i)
4300           i = s->sub.trees.index;
4301           t = s->sub.trees.table;
4302           if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
4303               (c == 16 && i < 1))
4304           {
4305             ZFREE(z, s->sub.trees.blens);
4306             s->mode = BADB;
4307             z->msg = "invalid bit length repeat";
4308             r = Z_DATA_ERROR;
4309             LEAVE
4310           }
4311           c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
4312           do {
4313             s->sub.trees.blens[i++] = c;
4314           } while (--j);
4315           s->sub.trees.index = i;
4316         }
4317       }
4318       s->sub.trees.tb = Z_NULL;
4319       {
4320         uInt bl, bd;
4321         inflate_huft *tl, *td;
4322         inflate_codes_statef *c;
4323 
4324         bl = 9;         /* must be <= 9 for lookahead assumptions */
4325         bd = 6;         /* must be <= 9 for lookahead assumptions */
4326         t = s->sub.trees.table;
4327         t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
4328                                   s->sub.trees.blens, &bl, &bd, &tl, &td,
4329                                   s->hufts, z);
4330         if (t != Z_OK)
4331         {
4332           if (t == (uInt)Z_DATA_ERROR)
4333           {
4334             ZFREE(z, s->sub.trees.blens);
4335             s->mode = BADB;
4336           }
4337           r = t;
4338           LEAVE
4339         }
4340         Tracev((stderr, "inflate:       trees ok\n"));
4341         if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
4342         {
4343           r = Z_MEM_ERROR;
4344           LEAVE
4345         }
4346         s->sub.decode.codes = c;
4347       }
4348       ZFREE(z, s->sub.trees.blens);
4349       s->mode = CODES;
4350     case CODES:
4351       UPDATE
4352       if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
4353         return inflate_flush(s, z, r);
4354       r = Z_OK;
4355       inflate_codes_free(s->sub.decode.codes, z);
4356       LOAD
4357       Tracev((stderr, "inflate:       codes end, %lu total out\n",
4358               z->total_out + (q >= s->read ? q - s->read :
4359               (s->end - s->read) + (q - s->window))));
4360       if (!s->last)
4361       {
4362         s->mode = TYPE;
4363         break;
4364       }
4365       s->mode = DRY;
4366     case DRY:
4367       FLUSH
4368       if (s->read != s->write)
4369         LEAVE
4370       s->mode = DONEB;
4371     case DONEB:
4372       r = Z_STREAM_END;
4373       LEAVE
4374     case BADB:
4375       r = Z_DATA_ERROR;
4376       LEAVE
4377     default:
4378       r = Z_STREAM_ERROR;
4379       LEAVE
4380   }
4381 }
4382 
4383 
4384 int inflate_blocks_free(s, z)
4385 inflate_blocks_statef *s;
4386 z_streamp z;
4387 {
4388   inflate_blocks_reset(s, z, Z_NULL);
4389   ZFREE(z, s->window);
4390   ZFREE(z, s->hufts);
4391   ZFREE(z, s);
4392   Tracev((stderr, "inflate:   blocks freed\n"));
4393   return Z_OK;
4394 }
4395 
4396 
4397 #if 0
4398 void inflate_set_dictionary(s, d, n)
4399 inflate_blocks_statef *s;
4400 const Bytef *d;
4401 uInt  n;
4402 {
4403   zmemcpy(s->window, d, n);
4404   s->read = s->write = s->window + n;
4405 }
4406 #endif
4407 
4408 /*
4409  * This subroutine adds the data at next_in/avail_in to the output history
4410  * without performing any output.  The output buffer must be "caught up";
4411  * i.e. no pending output (hence s->read equals s->write), and the state must
4412  * be BLOCKS (i.e. we should be willing to see the start of a series of
4413  * BLOCKS).  On exit, the output will also be caught up, and the checksum
4414  * will have been updated if need be.
4415  */
4416 int inflate_addhistory(s, z)
4417 inflate_blocks_statef *s;
4418 z_stream *z;
4419 {
4420     uLong b;              /* bit buffer */  /* NOT USED HERE */
4421     uInt k;               /* bits in bit buffer */ /* NOT USED HERE */
4422     uInt t;               /* temporary storage */
4423     Bytef *p;             /* input data pointer */
4424     uInt n;               /* bytes available there */
4425     Bytef *q;             /* output window write pointer */
4426     uInt m;               /* bytes to end of window or read pointer */
4427 
4428     if (s->read != s->write)
4429 	return Z_STREAM_ERROR;
4430     if (s->mode != TYPE)
4431 	return Z_DATA_ERROR;
4432 
4433     /* we're ready to rock */
4434     LOAD
4435     /* while there is input ready, copy to output buffer, moving
4436      * pointers as needed.
4437      */
4438     while (n) {
4439 	t = n;  /* how many to do */
4440 	/* is there room until end of buffer? */
4441 	if (t > m) t = m;
4442 	/* update check information */
4443 	if (s->checkfn != Z_NULL)
4444 	    s->check = (*s->checkfn)(s->check, q, t);
4445 	zmemcpy(q, p, t);
4446 	q += t;
4447 	p += t;
4448 	n -= t;
4449 	z->total_out += t;
4450 	s->read = q;    /* drag read pointer forward */
4451 /*      WWRAP  */ 	/* expand WWRAP macro by hand to handle s->read */
4452 	if (q == s->end) {
4453 	    s->read = q = s->window;
4454 	    m = WAVAIL;
4455 	}
4456     }
4457     UPDATE
4458     return Z_OK;
4459 }
4460 
4461 
4462 /*
4463  * At the end of a Deflate-compressed PPP packet, we expect to have seen
4464  * a `stored' block type value but not the (zero) length bytes.
4465  */
4466 int inflate_packet_flush(s)
4467     inflate_blocks_statef *s;
4468 {
4469     if (s->mode != LENS)
4470 	return Z_DATA_ERROR;
4471     s->mode = TYPE;
4472     return Z_OK;
4473 }
4474 
4475 /* Returns true if inflate is currently at the end of a block generated
4476  * by Z_SYNC_FLUSH or Z_FULL_FLUSH.
4477  * IN assertion: s != Z_NULL
4478  */
4479 #if 0
4480 int inflate_blocks_sync_point(s)
4481 inflate_blocks_statef *s;
4482 {
4483   return s->mode == LENS;
4484 }
4485 #endif
4486 /* --- infblock.c */
4487 
4488 
4489 /* +++ inftrees.c */
4490 
4491 /* inftrees.c -- generate Huffman trees for efficient decoding
4492  * Copyright (C) 1995-2002 Mark Adler
4493  * For conditions of distribution and use, see copyright notice in zlib.h
4494  */
4495 
4496 /* #include "zutil.h" */
4497 /* #include "inftrees.h" */
4498 
4499 #if !defined(BUILDFIXED) && !defined(STDC)
4500 #  define BUILDFIXED   /* non ANSI compilers may not accept inffixed.h */
4501 #endif
4502 
4503 const char inflate_copyright[] =
4504    " inflate 1.1.4 Copyright 1995-2002 Mark Adler ";
4505 /*
4506   If you use the zlib library in a product, an acknowledgment is welcome
4507   in the documentation of your product. If for some reason you cannot
4508   include such an acknowledgment, I would appreciate that you keep this
4509   copyright string in the executable of your product.
4510  */
4511 
4512 #ifndef NO_DUMMY_DECL
4513 struct internal_state  {int dummy;}; /* for buggy compilers */
4514 #endif
4515 
4516 /* simplify the use of the inflate_huft type with some defines */
4517 #define exop word.what.Exop
4518 #define bits word.what.Bits
4519 
4520 
4521 local int huft_build __P((
4522     uIntf *,            /* code lengths in bits */
4523     uInt,               /* number of codes */
4524     uInt,               /* number of "simple" codes */
4525     const uIntf *,      /* list of base values for non-simple codes */
4526     const uIntf *,      /* list of extra bits for non-simple codes */
4527     inflate_huft * FAR*,/* result: starting table */
4528     uIntf *,            /* maximum lookup bits (returns actual) */
4529     inflate_huft *,     /* space for trees */
4530     uInt *,             /* hufts used in space */
4531     uIntf * ));         /* space for values */
4532 
4533 /* Tables for deflate from PKZIP's appnote.txt. */
4534 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4535         3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4536         35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4537         /* see note #13 above about 258 */
4538 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4539         0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4540         3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4541 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4542         1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4543         257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4544         8193, 12289, 16385, 24577};
4545 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4546         0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4547         7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4548         12, 12, 13, 13};
4549 
4550 /*
4551    Huffman code decoding is performed using a multi-level table lookup.
4552    The fastest way to decode is to simply build a lookup table whose
4553    size is determined by the longest code.  However, the time it takes
4554    to build this table can also be a factor if the data being decoded
4555    is not very long.  The most common codes are necessarily the
4556    shortest codes, so those codes dominate the decoding time, and hence
4557    the speed.  The idea is you can have a shorter table that decodes the
4558    shorter, more probable codes, and then point to subsidiary tables for
4559    the longer codes.  The time it costs to decode the longer codes is
4560    then traded against the time it takes to make longer tables.
4561 
4562    This results of this trade are in the variables lbits and dbits
4563    below.  lbits is the number of bits the first level table for literal/
4564    length codes can decode in one step, and dbits is the same thing for
4565    the distance codes.  Subsequent tables are also less than or equal to
4566    those sizes.  These values may be adjusted either when all of the
4567    codes are shorter than that, in which case the longest code length in
4568    bits is used, or when the shortest code is *longer* than the requested
4569    table size, in which case the length of the shortest code in bits is
4570    used.
4571 
4572    There are two different values for the two tables, since they code a
4573    different number of possibilities each.  The literal/length table
4574    codes 286 possible values, or in a flat code, a little over eight
4575    bits.  The distance table codes 30 possible values, or a little less
4576    than five bits, flat.  The optimum values for speed end up being
4577    about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4578    The optimum values may differ though from machine to machine, and
4579    possibly even between compilers.  Your mileage may vary.
4580  */
4581 
4582 
4583 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4584 #define BMAX 15         /* maximum bit length of any code */
4585 
4586 local int huft_build(b, n, s, d, e, t, m, hp, hn, v)
4587 uIntf *b;               /* code lengths in bits (all assumed <= BMAX) */
4588 uInt n;                 /* number of codes (assumed <= 288) */
4589 uInt s;                 /* number of simple-valued codes (0..s-1) */
4590 const uIntf *d;         /* list of base values for non-simple codes */
4591 const uIntf *e;         /* list of extra bits for non-simple codes */
4592 inflate_huft * FAR *t;  /* result: starting table */
4593 uIntf *m;               /* maximum lookup bits, returns actual */
4594 inflate_huft *hp;       /* space for trees */
4595 uInt *hn;               /* hufts used in space */
4596 uIntf *v;               /* working area: values in order of bit length */
4597 /* Given a list of code lengths and a maximum table size, make a set of
4598    tables to decode that set of codes.  Return Z_OK on success, Z_BUF_ERROR
4599    if the given code set is incomplete (the tables are still built in this
4600    case), or Z_DATA_ERROR if the input is invalid. */
4601 {
4602 
4603   uInt a;                       /* counter for codes of length k */
4604   uInt c[BMAX+1];               /* bit length count table */
4605   uInt f;                       /* i repeats in table every f entries */
4606   int g;                        /* maximum code length */
4607   int h;                        /* table level */
4608   uInt i;                       /* counter, current code */
4609   uInt j;                       /* counter */
4610   int k;                        /* number of bits in current code */
4611   int l;                        /* bits per table (returned in m) */
4612   uInt mask;                    /* (1 << w) - 1, to avoid cc -O bug on HP */
4613   uIntf *p;                      /* pointer into c[], b[], or v[] */
4614   inflate_huft *q;              /* points to current table */
4615   struct inflate_huft_s r;      /* table entry for structure assignment */
4616   inflate_huft *u[BMAX];        /* table stack */
4617   int w;               /* bits before this table == (l * h) */
4618   uInt x[BMAX+1];               /* bit offsets, then code stack */
4619   uIntf *xp;                    /* pointer into x */
4620   int y;                        /* number of dummy codes added */
4621   uInt z;                       /* number of entries in current table */
4622 
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       while ((i & mask) != x[h])
4772       {
4773         h--;                    /* don't need to update q */
4774         w -= l;
4775         mask = (1 << w) - 1;
4776       }
4777     }
4778   }
4779 
4780 
4781   /* Return Z_BUF_ERROR if we were given an incomplete table */
4782   return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4783 }
4784 
4785 
4786 int inflate_trees_bits(c, bb, tb, hp, z)
4787 uIntf *c;               /* 19 code lengths */
4788 uIntf *bb;              /* bits tree desired/actual depth */
4789 inflate_huft * FAR *tb; /* bits tree result */
4790 inflate_huft *hp;       /* space for trees */
4791 z_streamp z;            /* for messages */
4792 {
4793   int r;
4794   uInt hn = 0;          /* hufts used in space */
4795   uIntf *v;             /* work area for huft_build */
4796 
4797   if ((v = (uIntf*)ZALLOC(z, 19, sizeof(uInt))) == Z_NULL)
4798     return Z_MEM_ERROR;
4799   r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL,
4800                  tb, bb, hp, &hn, v);
4801   if (r == Z_DATA_ERROR)
4802     z->msg = "oversubscribed dynamic bit lengths tree";
4803   else if (r == Z_BUF_ERROR || *bb == 0)
4804   {
4805     z->msg = "incomplete dynamic bit lengths tree";
4806     r = Z_DATA_ERROR;
4807   }
4808   ZFREE(z, v);
4809   return r;
4810 }
4811 
4812 
4813 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, hp, z)
4814 uInt nl;                /* number of literal/length codes */
4815 uInt nd;                /* number of distance codes */
4816 uIntf *c;               /* that many (total) code lengths */
4817 uIntf *bl;              /* literal desired/actual bit depth */
4818 uIntf *bd;              /* distance desired/actual bit depth */
4819 inflate_huft * FAR *tl; /* literal/length tree result */
4820 inflate_huft * FAR *td; /* distance tree result */
4821 inflate_huft *hp;       /* space for trees */
4822 z_streamp z;            /* for messages */
4823 {
4824   int r;
4825   uInt hn = 0;          /* hufts used in space */
4826   uIntf *v;             /* work area for huft_build */
4827 
4828   /* allocate work area */
4829   if ((v = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
4830     return Z_MEM_ERROR;
4831 
4832   /* build literal/length tree */
4833   r = huft_build(c, nl, 257, cplens, cplext, tl, bl, hp, &hn, v);
4834   if (r != Z_OK || *bl == 0)
4835   {
4836     if (r == Z_DATA_ERROR)
4837       z->msg = "oversubscribed literal/length tree";
4838     else if (r != Z_MEM_ERROR)
4839     {
4840       z->msg = "incomplete literal/length tree";
4841       r = Z_DATA_ERROR;
4842     }
4843     ZFREE(z, v);
4844     return r;
4845   }
4846 
4847   /* build distance tree */
4848   r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, hp, &hn, v);
4849   if (r != Z_OK || (*bd == 0 && nl > 257))
4850   {
4851     if (r == Z_DATA_ERROR)
4852       z->msg = "oversubscribed distance tree";
4853     else if (r == Z_BUF_ERROR) {
4854 #ifdef PKZIP_BUG_WORKAROUND
4855       r = Z_OK;
4856     }
4857 #else
4858       z->msg = "incomplete distance tree";
4859       r = Z_DATA_ERROR;
4860     }
4861     else if (r != Z_MEM_ERROR)
4862     {
4863       z->msg = "empty distance tree with lengths";
4864       r = Z_DATA_ERROR;
4865     }
4866     ZFREE(z, v);
4867     return r;
4868 #endif
4869   }
4870 
4871   /* done */
4872   ZFREE(z, v);
4873   return Z_OK;
4874 }
4875 
4876 
4877 /* build fixed tables only once--keep them here */
4878 #ifdef BUILDFIXED
4879 local int fixed_built = 0;
4880 #define FIXEDH 544      /* number of hufts used by fixed tables */
4881 local inflate_huft fixed_mem[FIXEDH];
4882 local uInt fixed_bl;
4883 local uInt fixed_bd;
4884 local inflate_huft *fixed_tl;
4885 local inflate_huft *fixed_td;
4886 #else
4887 
4888 /* +++ inffixed.h */
4889 /* inffixed.h -- table for decoding fixed codes
4890  * Generated automatically by the maketree.c program
4891  */
4892 
4893 /* WARNING: this file should *not* be used by applications. It is
4894    part of the implementation of the compression library and is
4895    subject to change. Applications should only use zlib.h.
4896  */
4897 
4898 local uInt fixed_bl = 9;
4899 local uInt fixed_bd = 5;
4900 local inflate_huft fixed_tl[] = {
4901     {{{96,7}},256}, {{{0,8}},80}, {{{0,8}},16}, {{{84,8}},115},
4902     {{{82,7}},31}, {{{0,8}},112}, {{{0,8}},48}, {{{0,9}},192},
4903     {{{80,7}},10}, {{{0,8}},96}, {{{0,8}},32}, {{{0,9}},160},
4904     {{{0,8}},0}, {{{0,8}},128}, {{{0,8}},64}, {{{0,9}},224},
4905     {{{80,7}},6}, {{{0,8}},88}, {{{0,8}},24}, {{{0,9}},144},
4906     {{{83,7}},59}, {{{0,8}},120}, {{{0,8}},56}, {{{0,9}},208},
4907     {{{81,7}},17}, {{{0,8}},104}, {{{0,8}},40}, {{{0,9}},176},
4908     {{{0,8}},8}, {{{0,8}},136}, {{{0,8}},72}, {{{0,9}},240},
4909     {{{80,7}},4}, {{{0,8}},84}, {{{0,8}},20}, {{{85,8}},227},
4910     {{{83,7}},43}, {{{0,8}},116}, {{{0,8}},52}, {{{0,9}},200},
4911     {{{81,7}},13}, {{{0,8}},100}, {{{0,8}},36}, {{{0,9}},168},
4912     {{{0,8}},4}, {{{0,8}},132}, {{{0,8}},68}, {{{0,9}},232},
4913     {{{80,7}},8}, {{{0,8}},92}, {{{0,8}},28}, {{{0,9}},152},
4914     {{{84,7}},83}, {{{0,8}},124}, {{{0,8}},60}, {{{0,9}},216},
4915     {{{82,7}},23}, {{{0,8}},108}, {{{0,8}},44}, {{{0,9}},184},
4916     {{{0,8}},12}, {{{0,8}},140}, {{{0,8}},76}, {{{0,9}},248},
4917     {{{80,7}},3}, {{{0,8}},82}, {{{0,8}},18}, {{{85,8}},163},
4918     {{{83,7}},35}, {{{0,8}},114}, {{{0,8}},50}, {{{0,9}},196},
4919     {{{81,7}},11}, {{{0,8}},98}, {{{0,8}},34}, {{{0,9}},164},
4920     {{{0,8}},2}, {{{0,8}},130}, {{{0,8}},66}, {{{0,9}},228},
4921     {{{80,7}},7}, {{{0,8}},90}, {{{0,8}},26}, {{{0,9}},148},
4922     {{{84,7}},67}, {{{0,8}},122}, {{{0,8}},58}, {{{0,9}},212},
4923     {{{82,7}},19}, {{{0,8}},106}, {{{0,8}},42}, {{{0,9}},180},
4924     {{{0,8}},10}, {{{0,8}},138}, {{{0,8}},74}, {{{0,9}},244},
4925     {{{80,7}},5}, {{{0,8}},86}, {{{0,8}},22}, {{{192,8}},0},
4926     {{{83,7}},51}, {{{0,8}},118}, {{{0,8}},54}, {{{0,9}},204},
4927     {{{81,7}},15}, {{{0,8}},102}, {{{0,8}},38}, {{{0,9}},172},
4928     {{{0,8}},6}, {{{0,8}},134}, {{{0,8}},70}, {{{0,9}},236},
4929     {{{80,7}},9}, {{{0,8}},94}, {{{0,8}},30}, {{{0,9}},156},
4930     {{{84,7}},99}, {{{0,8}},126}, {{{0,8}},62}, {{{0,9}},220},
4931     {{{82,7}},27}, {{{0,8}},110}, {{{0,8}},46}, {{{0,9}},188},
4932     {{{0,8}},14}, {{{0,8}},142}, {{{0,8}},78}, {{{0,9}},252},
4933     {{{96,7}},256}, {{{0,8}},81}, {{{0,8}},17}, {{{85,8}},131},
4934     {{{82,7}},31}, {{{0,8}},113}, {{{0,8}},49}, {{{0,9}},194},
4935     {{{80,7}},10}, {{{0,8}},97}, {{{0,8}},33}, {{{0,9}},162},
4936     {{{0,8}},1}, {{{0,8}},129}, {{{0,8}},65}, {{{0,9}},226},
4937     {{{80,7}},6}, {{{0,8}},89}, {{{0,8}},25}, {{{0,9}},146},
4938     {{{83,7}},59}, {{{0,8}},121}, {{{0,8}},57}, {{{0,9}},210},
4939     {{{81,7}},17}, {{{0,8}},105}, {{{0,8}},41}, {{{0,9}},178},
4940     {{{0,8}},9}, {{{0,8}},137}, {{{0,8}},73}, {{{0,9}},242},
4941     {{{80,7}},4}, {{{0,8}},85}, {{{0,8}},21}, {{{80,8}},258},
4942     {{{83,7}},43}, {{{0,8}},117}, {{{0,8}},53}, {{{0,9}},202},
4943     {{{81,7}},13}, {{{0,8}},101}, {{{0,8}},37}, {{{0,9}},170},
4944     {{{0,8}},5}, {{{0,8}},133}, {{{0,8}},69}, {{{0,9}},234},
4945     {{{80,7}},8}, {{{0,8}},93}, {{{0,8}},29}, {{{0,9}},154},
4946     {{{84,7}},83}, {{{0,8}},125}, {{{0,8}},61}, {{{0,9}},218},
4947     {{{82,7}},23}, {{{0,8}},109}, {{{0,8}},45}, {{{0,9}},186},
4948     {{{0,8}},13}, {{{0,8}},141}, {{{0,8}},77}, {{{0,9}},250},
4949     {{{80,7}},3}, {{{0,8}},83}, {{{0,8}},19}, {{{85,8}},195},
4950     {{{83,7}},35}, {{{0,8}},115}, {{{0,8}},51}, {{{0,9}},198},
4951     {{{81,7}},11}, {{{0,8}},99}, {{{0,8}},35}, {{{0,9}},166},
4952     {{{0,8}},3}, {{{0,8}},131}, {{{0,8}},67}, {{{0,9}},230},
4953     {{{80,7}},7}, {{{0,8}},91}, {{{0,8}},27}, {{{0,9}},150},
4954     {{{84,7}},67}, {{{0,8}},123}, {{{0,8}},59}, {{{0,9}},214},
4955     {{{82,7}},19}, {{{0,8}},107}, {{{0,8}},43}, {{{0,9}},182},
4956     {{{0,8}},11}, {{{0,8}},139}, {{{0,8}},75}, {{{0,9}},246},
4957     {{{80,7}},5}, {{{0,8}},87}, {{{0,8}},23}, {{{192,8}},0},
4958     {{{83,7}},51}, {{{0,8}},119}, {{{0,8}},55}, {{{0,9}},206},
4959     {{{81,7}},15}, {{{0,8}},103}, {{{0,8}},39}, {{{0,9}},174},
4960     {{{0,8}},7}, {{{0,8}},135}, {{{0,8}},71}, {{{0,9}},238},
4961     {{{80,7}},9}, {{{0,8}},95}, {{{0,8}},31}, {{{0,9}},158},
4962     {{{84,7}},99}, {{{0,8}},127}, {{{0,8}},63}, {{{0,9}},222},
4963     {{{82,7}},27}, {{{0,8}},111}, {{{0,8}},47}, {{{0,9}},190},
4964     {{{0,8}},15}, {{{0,8}},143}, {{{0,8}},79}, {{{0,9}},254},
4965     {{{96,7}},256}, {{{0,8}},80}, {{{0,8}},16}, {{{84,8}},115},
4966     {{{82,7}},31}, {{{0,8}},112}, {{{0,8}},48}, {{{0,9}},193},
4967     {{{80,7}},10}, {{{0,8}},96}, {{{0,8}},32}, {{{0,9}},161},
4968     {{{0,8}},0}, {{{0,8}},128}, {{{0,8}},64}, {{{0,9}},225},
4969     {{{80,7}},6}, {{{0,8}},88}, {{{0,8}},24}, {{{0,9}},145},
4970     {{{83,7}},59}, {{{0,8}},120}, {{{0,8}},56}, {{{0,9}},209},
4971     {{{81,7}},17}, {{{0,8}},104}, {{{0,8}},40}, {{{0,9}},177},
4972     {{{0,8}},8}, {{{0,8}},136}, {{{0,8}},72}, {{{0,9}},241},
4973     {{{80,7}},4}, {{{0,8}},84}, {{{0,8}},20}, {{{85,8}},227},
4974     {{{83,7}},43}, {{{0,8}},116}, {{{0,8}},52}, {{{0,9}},201},
4975     {{{81,7}},13}, {{{0,8}},100}, {{{0,8}},36}, {{{0,9}},169},
4976     {{{0,8}},4}, {{{0,8}},132}, {{{0,8}},68}, {{{0,9}},233},
4977     {{{80,7}},8}, {{{0,8}},92}, {{{0,8}},28}, {{{0,9}},153},
4978     {{{84,7}},83}, {{{0,8}},124}, {{{0,8}},60}, {{{0,9}},217},
4979     {{{82,7}},23}, {{{0,8}},108}, {{{0,8}},44}, {{{0,9}},185},
4980     {{{0,8}},12}, {{{0,8}},140}, {{{0,8}},76}, {{{0,9}},249},
4981     {{{80,7}},3}, {{{0,8}},82}, {{{0,8}},18}, {{{85,8}},163},
4982     {{{83,7}},35}, {{{0,8}},114}, {{{0,8}},50}, {{{0,9}},197},
4983     {{{81,7}},11}, {{{0,8}},98}, {{{0,8}},34}, {{{0,9}},165},
4984     {{{0,8}},2}, {{{0,8}},130}, {{{0,8}},66}, {{{0,9}},229},
4985     {{{80,7}},7}, {{{0,8}},90}, {{{0,8}},26}, {{{0,9}},149},
4986     {{{84,7}},67}, {{{0,8}},122}, {{{0,8}},58}, {{{0,9}},213},
4987     {{{82,7}},19}, {{{0,8}},106}, {{{0,8}},42}, {{{0,9}},181},
4988     {{{0,8}},10}, {{{0,8}},138}, {{{0,8}},74}, {{{0,9}},245},
4989     {{{80,7}},5}, {{{0,8}},86}, {{{0,8}},22}, {{{192,8}},0},
4990     {{{83,7}},51}, {{{0,8}},118}, {{{0,8}},54}, {{{0,9}},205},
4991     {{{81,7}},15}, {{{0,8}},102}, {{{0,8}},38}, {{{0,9}},173},
4992     {{{0,8}},6}, {{{0,8}},134}, {{{0,8}},70}, {{{0,9}},237},
4993     {{{80,7}},9}, {{{0,8}},94}, {{{0,8}},30}, {{{0,9}},157},
4994     {{{84,7}},99}, {{{0,8}},126}, {{{0,8}},62}, {{{0,9}},221},
4995     {{{82,7}},27}, {{{0,8}},110}, {{{0,8}},46}, {{{0,9}},189},
4996     {{{0,8}},14}, {{{0,8}},142}, {{{0,8}},78}, {{{0,9}},253},
4997     {{{96,7}},256}, {{{0,8}},81}, {{{0,8}},17}, {{{85,8}},131},
4998     {{{82,7}},31}, {{{0,8}},113}, {{{0,8}},49}, {{{0,9}},195},
4999     {{{80,7}},10}, {{{0,8}},97}, {{{0,8}},33}, {{{0,9}},163},
5000     {{{0,8}},1}, {{{0,8}},129}, {{{0,8}},65}, {{{0,9}},227},
5001     {{{80,7}},6}, {{{0,8}},89}, {{{0,8}},25}, {{{0,9}},147},
5002     {{{83,7}},59}, {{{0,8}},121}, {{{0,8}},57}, {{{0,9}},211},
5003     {{{81,7}},17}, {{{0,8}},105}, {{{0,8}},41}, {{{0,9}},179},
5004     {{{0,8}},9}, {{{0,8}},137}, {{{0,8}},73}, {{{0,9}},243},
5005     {{{80,7}},4}, {{{0,8}},85}, {{{0,8}},21}, {{{80,8}},258},
5006     {{{83,7}},43}, {{{0,8}},117}, {{{0,8}},53}, {{{0,9}},203},
5007     {{{81,7}},13}, {{{0,8}},101}, {{{0,8}},37}, {{{0,9}},171},
5008     {{{0,8}},5}, {{{0,8}},133}, {{{0,8}},69}, {{{0,9}},235},
5009     {{{80,7}},8}, {{{0,8}},93}, {{{0,8}},29}, {{{0,9}},155},
5010     {{{84,7}},83}, {{{0,8}},125}, {{{0,8}},61}, {{{0,9}},219},
5011     {{{82,7}},23}, {{{0,8}},109}, {{{0,8}},45}, {{{0,9}},187},
5012     {{{0,8}},13}, {{{0,8}},141}, {{{0,8}},77}, {{{0,9}},251},
5013     {{{80,7}},3}, {{{0,8}},83}, {{{0,8}},19}, {{{85,8}},195},
5014     {{{83,7}},35}, {{{0,8}},115}, {{{0,8}},51}, {{{0,9}},199},
5015     {{{81,7}},11}, {{{0,8}},99}, {{{0,8}},35}, {{{0,9}},167},
5016     {{{0,8}},3}, {{{0,8}},131}, {{{0,8}},67}, {{{0,9}},231},
5017     {{{80,7}},7}, {{{0,8}},91}, {{{0,8}},27}, {{{0,9}},151},
5018     {{{84,7}},67}, {{{0,8}},123}, {{{0,8}},59}, {{{0,9}},215},
5019     {{{82,7}},19}, {{{0,8}},107}, {{{0,8}},43}, {{{0,9}},183},
5020     {{{0,8}},11}, {{{0,8}},139}, {{{0,8}},75}, {{{0,9}},247},
5021     {{{80,7}},5}, {{{0,8}},87}, {{{0,8}},23}, {{{192,8}},0},
5022     {{{83,7}},51}, {{{0,8}},119}, {{{0,8}},55}, {{{0,9}},207},
5023     {{{81,7}},15}, {{{0,8}},103}, {{{0,8}},39}, {{{0,9}},175},
5024     {{{0,8}},7}, {{{0,8}},135}, {{{0,8}},71}, {{{0,9}},239},
5025     {{{80,7}},9}, {{{0,8}},95}, {{{0,8}},31}, {{{0,9}},159},
5026     {{{84,7}},99}, {{{0,8}},127}, {{{0,8}},63}, {{{0,9}},223},
5027     {{{82,7}},27}, {{{0,8}},111}, {{{0,8}},47}, {{{0,9}},191},
5028     {{{0,8}},15}, {{{0,8}},143}, {{{0,8}},79}, {{{0,9}},255}
5029   };
5030 local inflate_huft fixed_td[] = {
5031     {{{80,5}},1}, {{{87,5}},257}, {{{83,5}},17}, {{{91,5}},4097},
5032     {{{81,5}},5}, {{{89,5}},1025}, {{{85,5}},65}, {{{93,5}},16385},
5033     {{{80,5}},3}, {{{88,5}},513}, {{{84,5}},33}, {{{92,5}},8193},
5034     {{{82,5}},9}, {{{90,5}},2049}, {{{86,5}},129}, {{{192,5}},24577},
5035     {{{80,5}},2}, {{{87,5}},385}, {{{83,5}},25}, {{{91,5}},6145},
5036     {{{81,5}},7}, {{{89,5}},1537}, {{{85,5}},97}, {{{93,5}},24577},
5037     {{{80,5}},4}, {{{88,5}},769}, {{{84,5}},49}, {{{92,5}},12289},
5038     {{{82,5}},13}, {{{90,5}},3073}, {{{86,5}},193}, {{{192,5}},24577}
5039   };
5040 /* --- inffixed.h */
5041 
5042 #endif
5043 
5044 
5045 int inflate_trees_fixed(bl, bd, tl, td, z)
5046 uIntf *bl;               /* literal desired/actual bit depth */
5047 uIntf *bd;               /* distance desired/actual bit depth */
5048 inflate_huft * FAR *tl;  /* literal/length tree result */
5049 inflate_huft * FAR *td;  /* distance tree result */
5050 z_streamp z;             /* for memory allocation */
5051 {
5052 #ifdef BUILDFIXED
5053   /* build fixed tables if not already */
5054   if (!fixed_built)
5055   {
5056     int k;              /* temporary variable */
5057     uInt f = 0;         /* number of hufts used in fixed_mem */
5058     uIntf *c;           /* length list for huft_build */
5059     uIntf *v;           /* work area for huft_build */
5060 
5061     /* allocate memory */
5062     if ((c = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
5063       return Z_MEM_ERROR;
5064     if ((v = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
5065     {
5066       ZFREE(z, c);
5067       return Z_MEM_ERROR;
5068     }
5069 
5070     /* literal table */
5071     for (k = 0; k < 144; k++)
5072       c[k] = 8;
5073     for (; k < 256; k++)
5074       c[k] = 9;
5075     for (; k < 280; k++)
5076       c[k] = 7;
5077     for (; k < 288; k++)
5078       c[k] = 8;
5079     fixed_bl = 9;
5080     huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl,
5081                fixed_mem, &f, v);
5082 
5083     /* distance table */
5084     for (k = 0; k < 30; k++)
5085       c[k] = 5;
5086     fixed_bd = 5;
5087     huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd,
5088                fixed_mem, &f, v);
5089 
5090     /* done */
5091     ZFREE(z, v);
5092     ZFREE(z, c);
5093     fixed_built = 1;
5094   }
5095 #endif
5096   *bl = fixed_bl;
5097   *bd = fixed_bd;
5098   *tl = fixed_tl;
5099   *td = fixed_td;
5100   return Z_OK;
5101 }
5102 /* --- inftrees.c */
5103 
5104 /* +++ infcodes.c */
5105 
5106 /* infcodes.c -- process literals and length/distance pairs
5107  * Copyright (C) 1995-2002 Mark Adler
5108  * For conditions of distribution and use, see copyright notice in zlib.h
5109  */
5110 
5111 /* #include "zutil.h" */
5112 /* #include "inftrees.h" */
5113 /* #include "infblock.h" */
5114 /* #include "infcodes.h" */
5115 /* #include "infutil.h" */
5116 
5117 /* +++ inffast.h */
5118 
5119 /* inffast.h -- header to use inffast.c
5120  * Copyright (C) 1995-2002 Mark Adler
5121  * For conditions of distribution and use, see copyright notice in zlib.h
5122  */
5123 
5124 /* WARNING: this file should *not* be used by applications. It is
5125    part of the implementation of the compression library and is
5126    subject to change. Applications should only use zlib.h.
5127  */
5128 
5129 extern int inflate_fast __P((
5130     uInt,
5131     uInt,
5132     inflate_huft *,
5133     inflate_huft *,
5134     inflate_blocks_statef *,
5135     z_streamp ));
5136 /* --- inffast.h */
5137 
5138 /* simplify the use of the inflate_huft type with some defines */
5139 #define exop word.what.Exop
5140 #define bits word.what.Bits
5141 
5142 typedef enum {        /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
5143       START,    /* x: set up for LEN */
5144       LEN,      /* i: get length/literal/eob next */
5145       LENEXT,   /* i: getting length extra (have base) */
5146       DIST,     /* i: get distance next */
5147       DISTEXT,  /* i: getting distance extra */
5148       COPY,     /* o: copying bytes in window, waiting for space */
5149       LIT,      /* o: got literal, waiting for output space */
5150       WASH,     /* o: got eob, possibly still output waiting */
5151       END,      /* x: got eob and all data flushed */
5152       BADCODE}  /* x: got error */
5153 inflate_codes_mode;
5154 
5155 /* inflate codes private state */
5156 struct inflate_codes_state {
5157 
5158   /* mode */
5159   inflate_codes_mode mode;      /* current inflate_codes mode */
5160 
5161   /* mode dependent information */
5162   uInt len;
5163   union {
5164     struct {
5165       inflate_huft *tree;       /* pointer into tree */
5166       uInt need;                /* bits needed */
5167     } code;             /* if LEN or DIST, where in tree */
5168     uInt lit;           /* if LIT, literal */
5169     struct {
5170       uInt get;                 /* bits to get for extra */
5171       uInt dist;                /* distance back to copy from */
5172     } copy;             /* if EXT or COPY, where and how much */
5173   } sub;                /* submode */
5174 
5175   /* mode independent information */
5176   Byte lbits;           /* ltree bits decoded per branch */
5177   Byte dbits;           /* dtree bits decoder per branch */
5178   inflate_huft *ltree;          /* literal/length/eob tree */
5179   inflate_huft *dtree;          /* distance tree */
5180 
5181 };
5182 
5183 
5184 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
5185 uInt bl, bd;
5186 inflate_huft *tl;
5187 inflate_huft *td; /* need separate declaration for Borland C++ */
5188 z_streamp z;
5189 {
5190   inflate_codes_statef *c;
5191 
5192   if ((c = (inflate_codes_statef *)
5193        ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
5194   {
5195     c->mode = START;
5196     c->lbits = (Byte)bl;
5197     c->dbits = (Byte)bd;
5198     c->ltree = tl;
5199     c->dtree = td;
5200     Tracev((stderr, "inflate:       codes new\n"));
5201   }
5202   return c;
5203 }
5204 
5205 
5206 int inflate_codes(s, z, r)
5207 inflate_blocks_statef *s;
5208 z_streamp z;
5209 int r;
5210 {
5211   uInt j;               /* temporary storage */
5212   inflate_huft *t;      /* temporary pointer */
5213   uInt e;               /* extra bits or operation */
5214   uLong b;              /* bit buffer */
5215   uInt k;               /* bits in bit buffer */
5216   Bytef *p;             /* input data pointer */
5217   uInt n;               /* bytes available there */
5218   Bytef *q;             /* output window write pointer */
5219   uInt m;               /* bytes to end of window or read pointer */
5220   Bytef *f;             /* pointer to copy strings from */
5221   inflate_codes_statef *c = s->sub.decode.codes;  /* codes state */
5222 
5223   /* copy input/output information to locals (UPDATE macro restores) */
5224   LOAD
5225 
5226   /* process input and output based on current state */
5227   while (1) switch (c->mode)
5228   {             /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
5229     case START:         /* x: set up for LEN */
5230 #ifndef SLOW
5231       if (m >= 258 && n >= 10)
5232       {
5233         UPDATE
5234         r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
5235         LOAD
5236         if (r != Z_OK)
5237         {
5238           c->mode = r == Z_STREAM_END ? WASH : BADCODE;
5239           break;
5240         }
5241       }
5242 #endif /* !SLOW */
5243       c->sub.code.need = c->lbits;
5244       c->sub.code.tree = c->ltree;
5245       c->mode = LEN;
5246     case LEN:           /* i: get length/literal/eob next */
5247       j = c->sub.code.need;
5248       NEEDBITS(j)
5249       t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
5250       DUMPBITS(t->bits)
5251       e = (uInt)(t->exop);
5252       if (e == 0)               /* literal */
5253       {
5254         c->sub.lit = t->base;
5255         Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5256                  "inflate:         literal '%c'\n" :
5257                  "inflate:         literal 0x%02x\n", t->base));
5258         c->mode = LIT;
5259         break;
5260       }
5261       if (e & 16)               /* length */
5262       {
5263         c->sub.copy.get = e & 15;
5264         c->len = t->base;
5265         c->mode = LENEXT;
5266         break;
5267       }
5268       if ((e & 64) == 0)        /* next table */
5269       {
5270         c->sub.code.need = e;
5271         c->sub.code.tree = t + t->base;
5272         break;
5273       }
5274       if (e & 32)               /* end of block */
5275       {
5276         Tracevv((stderr, "inflate:         end of block\n"));
5277         c->mode = WASH;
5278         break;
5279       }
5280       c->mode = BADCODE;        /* invalid code */
5281       z->msg = "invalid literal/length code";
5282       r = Z_DATA_ERROR;
5283       LEAVE
5284     case LENEXT:        /* i: getting length extra (have base) */
5285       j = c->sub.copy.get;
5286       NEEDBITS(j)
5287       c->len += (uInt)b & inflate_mask[j];
5288       DUMPBITS(j)
5289       c->sub.code.need = c->dbits;
5290       c->sub.code.tree = c->dtree;
5291       Tracevv((stderr, "inflate:         length %u\n", c->len));
5292       c->mode = DIST;
5293     case DIST:          /* i: get distance next */
5294       j = c->sub.code.need;
5295       NEEDBITS(j)
5296       t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
5297       DUMPBITS(t->bits)
5298       e = (uInt)(t->exop);
5299       if (e & 16)               /* distance */
5300       {
5301         c->sub.copy.get = e & 15;
5302         c->sub.copy.dist = t->base;
5303         c->mode = DISTEXT;
5304         break;
5305       }
5306       if ((e & 64) == 0)        /* next table */
5307       {
5308         c->sub.code.need = e;
5309         c->sub.code.tree = t + t->base;
5310         break;
5311       }
5312       c->mode = BADCODE;        /* invalid code */
5313       z->msg = "invalid distance code";
5314       r = Z_DATA_ERROR;
5315       LEAVE
5316     case DISTEXT:       /* i: getting distance extra */
5317       j = c->sub.copy.get;
5318       NEEDBITS(j)
5319       c->sub.copy.dist += (uInt)b & inflate_mask[j];
5320       DUMPBITS(j)
5321       Tracevv((stderr, "inflate:         distance %u\n", c->sub.copy.dist));
5322       c->mode = COPY;
5323     case COPY:          /* o: copying bytes in window, waiting for space */
5324       f = q - c->sub.copy.dist;
5325       while (f < s->window)             /* modulo window size-"while" instead */
5326         f += s->end - s->window;        /* of "if" handles invalid distances */
5327       while (c->len)
5328       {
5329         NEEDOUT
5330         OUTBYTE(*f++)
5331         if (f == s->end)
5332           f = s->window;
5333         c->len--;
5334       }
5335       c->mode = START;
5336       break;
5337     case LIT:           /* o: got literal, waiting for output space */
5338       NEEDOUT
5339       OUTBYTE(c->sub.lit)
5340       c->mode = START;
5341       break;
5342     case WASH:          /* o: got eob, possibly more output */
5343       if (k > 7)        /* return unused byte, if any */
5344       {
5345         Assert(k < 16, "inflate_codes grabbed too many bytes")
5346         k -= 8;
5347         n++;
5348         p--;            /* can always return one */
5349       }
5350       FLUSH
5351       if (s->read != s->write)
5352         LEAVE
5353       c->mode = END;
5354     case END:
5355       r = Z_STREAM_END;
5356       LEAVE
5357     case BADCODE:       /* x: got error */
5358       r = Z_DATA_ERROR;
5359       LEAVE
5360     default:
5361       r = Z_STREAM_ERROR;
5362       LEAVE
5363   }
5364 #ifdef NEED_DUMMY_RETURN
5365   return Z_STREAM_ERROR;  /* Some dumb compilers complain without this */
5366 #endif
5367 }
5368 
5369 
5370 void inflate_codes_free(c, z)
5371 inflate_codes_statef *c;
5372 z_streamp z;
5373 {
5374   ZFREE(z, c);
5375   Tracev((stderr, "inflate:       codes free\n"));
5376 }
5377 /* --- infcodes.c */
5378 
5379 /* +++ infutil.c */
5380 
5381 /* inflate_util.c -- data and routines common to blocks and codes
5382  * Copyright (C) 1995-2002 Mark Adler
5383  * For conditions of distribution and use, see copyright notice in zlib.h
5384  */
5385 
5386 /* #include "zutil.h" */
5387 /* #include "infblock.h" */
5388 /* #include "inftrees.h" */
5389 /* #include "infcodes.h" */
5390 /* #include "infutil.h" */
5391 
5392 #ifndef NO_DUMMY_DECL
5393 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
5394 #endif
5395 
5396 /* And'ing with mask[n] masks the lower n bits */
5397 uInt inflate_mask[17] = {
5398     0x0000,
5399     0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
5400     0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
5401 };
5402 
5403 
5404 /* copy as much as possible from the sliding window to the output area */
5405 int inflate_flush(s, z, r)
5406 inflate_blocks_statef *s;
5407 z_streamp z;
5408 int r;
5409 {
5410   uInt n;
5411   Bytef *p;
5412   Bytef *q;
5413 
5414   /* local copies of source and destination pointers */
5415   p = z->next_out;
5416   q = s->read;
5417 
5418   /* compute number of bytes to copy as far as end of window */
5419   n = (uInt)((q <= s->write ? s->write : s->end) - q);
5420   if (n > z->avail_out) n = z->avail_out;
5421   if (n && r == Z_BUF_ERROR) r = Z_OK;
5422 
5423   /* update counters */
5424   z->avail_out -= n;
5425   z->total_out += n;
5426 
5427   /* update check information */
5428   if (s->checkfn != Z_NULL)
5429     z->adler = s->check = (*s->checkfn)(s->check, q, n);
5430 
5431   /* copy as far as end of window */
5432   if (p != Z_NULL) {
5433     zmemcpy(p, q, n);
5434     p += n;
5435   }
5436   q += n;
5437 
5438   /* see if more to copy at beginning of window */
5439   if (q == s->end)
5440   {
5441     /* wrap pointers */
5442     q = s->window;
5443     if (s->write == s->end)
5444       s->write = s->window;
5445 
5446     /* compute bytes to copy */
5447     n = (uInt)(s->write - q);
5448     if (n > z->avail_out) n = z->avail_out;
5449     if (n && r == Z_BUF_ERROR) r = Z_OK;
5450 
5451     /* update counters */
5452     z->avail_out -= n;
5453     z->total_out += n;
5454 
5455     /* update check information */
5456     if (s->checkfn != Z_NULL)
5457       z->adler = s->check = (*s->checkfn)(s->check, q, n);
5458 
5459     /* copy */
5460     if (p != NULL) {
5461       zmemcpy(p, q, n);
5462       p += n;
5463     }
5464     q += n;
5465   }
5466 
5467   /* update pointers */
5468   z->next_out = p;
5469   s->read = q;
5470 
5471   /* done */
5472   return r;
5473 }
5474 /* --- infutil.c */
5475 
5476 /* +++ inffast.c */
5477 
5478 /* inffast.c -- process literals and length/distance pairs fast
5479  * Copyright (C) 1995-2002 Mark Adler
5480  * For conditions of distribution and use, see copyright notice in zlib.h
5481  */
5482 
5483 /* #include "zutil.h" */
5484 /* #include "inftrees.h" */
5485 /* #include "infblock.h" */
5486 /* #include "infcodes.h" */
5487 /* #include "infutil.h" */
5488 /* #include "inffast.h" */
5489 
5490 #ifndef NO_DUMMY_DECL
5491 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
5492 #endif
5493 
5494 /* simplify the use of the inflate_huft type with some defines */
5495 #define exop word.what.Exop
5496 #define bits word.what.Bits
5497 
5498 /* macros for bit input with no checking and for returning unused bytes */
5499 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
5500 #define UNGRAB {c=z->avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;}
5501 
5502 /* Called with number of bytes left to write in window at least 258
5503    (the maximum string length) and number of input bytes available
5504    at least ten.  The ten bytes are six bytes for the longest length/
5505    distance pair plus four bytes for overloading the bit buffer. */
5506 
5507 int inflate_fast(bl, bd, tl, td, s, z)
5508 uInt bl, bd;
5509 inflate_huft *tl;
5510 inflate_huft *td; /* need separate declaration for Borland C++ */
5511 inflate_blocks_statef *s;
5512 z_streamp z;
5513 {
5514   inflate_huft *t;      /* temporary pointer */
5515   uInt e;               /* extra bits or operation */
5516   uLong b;              /* bit buffer */
5517   uInt k;               /* bits in bit buffer */
5518   Bytef *p;             /* input data pointer */
5519   uInt n;               /* bytes available there */
5520   Bytef *q;             /* output window write pointer */
5521   uInt m;               /* bytes to end of window or read pointer */
5522   uInt ml;              /* mask for literal/length tree */
5523   uInt md;              /* mask for distance tree */
5524   uInt c;               /* bytes to copy */
5525   uInt d;               /* distance back to copy from */
5526   Bytef *r;             /* copy source pointer */
5527 
5528   /* load input, output, bit values */
5529   LOAD
5530 
5531   /* initialize masks */
5532   ml = inflate_mask[bl];
5533   md = inflate_mask[bd];
5534 
5535   /* do until not enough input or output space for fast loop */
5536   do {                          /* assume called with m >= 258 && n >= 10 */
5537     /* get literal/length code */
5538     GRABBITS(20)                /* max bits for literal/length code */
5539     if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5540     {
5541       DUMPBITS(t->bits)
5542       Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5543                 "inflate:         * literal '%c'\n" :
5544                 "inflate:         * literal 0x%02x\n", t->base));
5545       *q++ = (Byte)t->base;
5546       m--;
5547       continue;
5548     }
5549     do {
5550       DUMPBITS(t->bits)
5551       if (e & 16)
5552       {
5553         /* get extra bits for length */
5554         e &= 15;
5555         c = t->base + ((uInt)b & inflate_mask[e]);
5556         DUMPBITS(e)
5557         Tracevv((stderr, "inflate:         * length %u\n", c));
5558 
5559         /* decode distance base of block to copy */
5560         GRABBITS(15);           /* max bits for distance code */
5561         e = (t = td + ((uInt)b & md))->exop;
5562         do {
5563           DUMPBITS(t->bits)
5564           if (e & 16)
5565           {
5566             /* get extra bits to add to distance base */
5567             e &= 15;
5568             GRABBITS(e)         /* get extra bits (up to 13) */
5569             d = t->base + ((uInt)b & inflate_mask[e]);
5570             DUMPBITS(e)
5571             Tracevv((stderr, "inflate:         * distance %u\n", d));
5572 
5573             /* do the copy */
5574             m -= c;
5575             r = q - d;
5576             if (r < s->window)                  /* wrap if needed */
5577             {
5578               do {
5579                 r += s->end - s->window;        /* force pointer in window */
5580               } while (r < s->window);          /* covers invalid distances */
5581               e = s->end - r;
5582               if (c > e)
5583               {
5584                 c -= e;                         /* wrapped copy */
5585                 do {
5586                     *q++ = *r++;
5587                 } while (--e);
5588                 r = s->window;
5589                 do {
5590                     *q++ = *r++;
5591                 } while (--c);
5592               }
5593               else                              /* normal copy */
5594               {
5595                 *q++ = *r++;  c--;
5596                 *q++ = *r++;  c--;
5597                 do {
5598                     *q++ = *r++;
5599                 } while (--c);
5600               }
5601             }
5602             else                                /* normal copy */
5603             {
5604               *q++ = *r++;  c--;
5605               *q++ = *r++;  c--;
5606               do {
5607                 *q++ = *r++;
5608               } while (--c);
5609             }
5610             break;
5611           }
5612           else if ((e & 64) == 0)
5613           {
5614             t += t->base;
5615             e = (t += ((uInt)b & inflate_mask[e]))->exop;
5616           }
5617           else
5618           {
5619             z->msg = "invalid distance code";
5620             UNGRAB
5621             UPDATE
5622             return Z_DATA_ERROR;
5623           }
5624         } while (1);
5625         break;
5626       }
5627       if ((e & 64) == 0)
5628       {
5629         t += t->base;
5630         if ((e = (t += ((uInt)b & inflate_mask[e]))->exop) == 0)
5631         {
5632           DUMPBITS(t->bits)
5633           Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5634                     "inflate:         * literal '%c'\n" :
5635                     "inflate:         * literal 0x%02x\n", t->base));
5636           *q++ = (Byte)t->base;
5637           m--;
5638           break;
5639         }
5640       }
5641       else if (e & 32)
5642       {
5643         Tracevv((stderr, "inflate:         * end of block\n"));
5644         UNGRAB
5645         UPDATE
5646         return Z_STREAM_END;
5647       }
5648       else
5649       {
5650         z->msg = "invalid literal/length code";
5651         UNGRAB
5652         UPDATE
5653         return Z_DATA_ERROR;
5654       }
5655     } while (1);
5656   } while (m >= 258 && n >= 10);
5657 
5658   /* not enough input or output--restore pointers and return */
5659   UNGRAB
5660   UPDATE
5661   return Z_OK;
5662 }
5663 /* --- inffast.c */
5664 
5665 /* +++ zutil.c */
5666 
5667 /* zutil.c -- target dependent utility functions for the compression library
5668  * Copyright (C) 1995-2002 Jean-loup Gailly.
5669  * For conditions of distribution and use, see copyright notice in zlib.h
5670  */
5671 
5672 /* @(#) Id */
5673 
5674 #ifdef DEBUG_ZLIB
5675 #include <stdio.h>
5676 #endif
5677 
5678 /* #include "zutil.h" */
5679 
5680 #ifndef NO_DUMMY_DECL
5681 struct internal_state      {int dummy;}; /* for buggy compilers */
5682 #endif
5683 
5684 #ifndef STDC
5685 extern void exit __P((int));
5686 #endif
5687 
5688 const char *z_errmsg[10] = {
5689 "need dictionary",     /* Z_NEED_DICT       2  */
5690 "stream end",          /* Z_STREAM_END      1  */
5691 "",                    /* Z_OK              0  */
5692 "file error",          /* Z_ERRNO         (-1) */
5693 "stream error",        /* Z_STREAM_ERROR  (-2) */
5694 "data error",          /* Z_DATA_ERROR    (-3) */
5695 "insufficient memory", /* Z_MEM_ERROR     (-4) */
5696 "buffer error",        /* Z_BUF_ERROR     (-5) */
5697 "incompatible version",/* Z_VERSION_ERROR (-6) */
5698 ""};
5699 
5700 
5701 #if 0
5702 const char * ZEXPORT zlibVersion()
5703 {
5704     return ZLIB_VERSION;
5705 }
5706 #endif
5707 
5708 #ifdef DEBUG_ZLIB
5709 
5710 #  ifndef verbose
5711 #    define verbose 0
5712 #  endif
5713 int z_verbose = verbose;
5714 
5715 void z_error (m)
5716     char *m;
5717 {
5718     fprintf(stderr, "%s\n", m);
5719     exit(1);
5720 }
5721 #endif
5722 
5723 /* exported to allow conversion of error code to string for compress() and
5724  * uncompress()
5725  */
5726 #if 0
5727 const char * ZEXPORT zError(err)
5728     int err;
5729 {
5730     return ERR_MSG(err);
5731 }
5732 #endif
5733 
5734 
5735 #ifndef HAVE_MEMCPY
5736 
5737 void zmemcpy(dest, source, len)
5738     Bytef* dest;
5739     const Bytef* source;
5740     uInt  len;
5741 {
5742     if (len == 0) return;
5743     do {
5744         *dest++ = *source++; /* ??? to be unrolled */
5745     } while (--len != 0);
5746 }
5747 
5748 int zmemcmp(s1, s2, len)
5749     const Bytef* s1;
5750     const Bytef* s2;
5751     uInt  len;
5752 {
5753     uInt j;
5754 
5755     for (j = 0; j < len; j++) {
5756         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5757     }
5758     return 0;
5759 }
5760 
5761 void zmemzero(dest, len)
5762     Bytef* dest;
5763     uInt  len;
5764 {
5765     if (len == 0) return;
5766     do {
5767         *dest++ = 0;  /* ??? to be unrolled */
5768     } while (--len != 0);
5769 }
5770 #endif
5771 
5772 #ifdef __TURBOC__
5773 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5774 /* Small and medium model in Turbo C are for now limited to near allocation
5775  * with reduced MAX_WBITS and MAX_MEM_LEVEL
5776  */
5777 #  define MY_ZCALLOC
5778 
5779 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5780  * and farmalloc(64K) returns a pointer with an offset of 8, so we
5781  * must fix the pointer. Warning: the pointer must be put back to its
5782  * original form in order to free it, use zcfree().
5783  */
5784 
5785 #define MAX_PTR 10
5786 /* 10*64K = 640K */
5787 
5788 local int next_ptr = 0;
5789 
5790 typedef struct ptr_table_s {
5791     voidpf org_ptr;
5792     voidpf new_ptr;
5793 } ptr_table;
5794 
5795 local ptr_table table[MAX_PTR];
5796 /* This table is used to remember the original form of pointers
5797  * to large buffers (64K). Such pointers are normalized with a zero offset.
5798  * Since MSDOS is not a preemptive multitasking OS, this table is not
5799  * protected from concurrent access. This hack doesn't work anyway on
5800  * a protected system like OS/2. Use Microsoft C instead.
5801  */
5802 
5803 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5804 {
5805     voidpf buf = opaque; /* just to make some compilers happy */
5806     ulg bsize = (ulg)items*size;
5807 
5808     /* If we allocate less than 65520 bytes, we assume that farmalloc
5809      * will return a usable pointer which doesn't have to be normalized.
5810      */
5811     if (bsize < 65520L) {
5812         buf = farmalloc(bsize);
5813         if (*(ush*)&buf != 0) return buf;
5814     } else {
5815         buf = farmalloc(bsize + 16L);
5816     }
5817     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5818     table[next_ptr].org_ptr = buf;
5819 
5820     /* Normalize the pointer to seg:0 */
5821     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5822     *(ush*)&buf = 0;
5823     table[next_ptr++].new_ptr = buf;
5824     return buf;
5825 }
5826 
5827 void  zcfree (voidpf opaque, voidpf ptr)
5828 {
5829     int n;
5830     if (*(ush*)&ptr != 0) { /* object < 64K */
5831         farfree(ptr);
5832         return;
5833     }
5834     /* Find the original pointer */
5835     for (n = 0; n < next_ptr; n++) {
5836         if (ptr != table[n].new_ptr) continue;
5837 
5838         farfree(table[n].org_ptr);
5839         while (++n < next_ptr) {
5840             table[n-1] = table[n];
5841         }
5842         next_ptr--;
5843         return;
5844     }
5845     ptr = opaque; /* just to make some compilers happy */
5846     Assert(0, "zcfree: ptr not found");
5847 }
5848 #endif
5849 #endif /* __TURBOC__ */
5850 
5851 
5852 #if defined(M_I86) && !defined(__32BIT__)
5853 /* Microsoft C in 16-bit mode */
5854 
5855 #  define MY_ZCALLOC
5856 
5857 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
5858 #  define _halloc  halloc
5859 #  define _hfree   hfree
5860 #endif
5861 
5862 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5863 {
5864     if (opaque) opaque = 0; /* to make compiler happy */
5865     return _halloc((long)items, size);
5866 }
5867 
5868 void  zcfree (voidpf opaque, voidpf ptr)
5869 {
5870     if (opaque) opaque = 0; /* to make compiler happy */
5871     _hfree(ptr);
5872 }
5873 
5874 #endif /* MSC */
5875 
5876 
5877 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5878 
5879 #ifndef STDC
5880 extern voidp  calloc __P((uInt items, uInt size));
5881 extern void   free   __P((voidpf ptr));
5882 #endif
5883 
5884 voidpf zcalloc (opaque, items, size)
5885     voidpf opaque;
5886     unsigned items;
5887     unsigned size;
5888 {
5889     if (opaque) items += size - size; /* make compiler happy */
5890     return (voidpf)calloc(items, size);
5891 }
5892 
5893 void  zcfree (opaque, ptr)
5894     voidpf opaque;
5895     voidpf ptr;
5896 {
5897     free(ptr);
5898     if (opaque) return; /* make compiler happy */
5899 }
5900 
5901 #endif /* MY_ZCALLOC */
5902 /* --- zutil.c */
5903 
5904 /* +++ adler32.c */
5905 /* adler32.c -- compute the Adler-32 checksum of a data stream
5906  * Copyright (C) 1995-2002 Mark Adler
5907  * For conditions of distribution and use, see copyright notice in zlib.h
5908  */
5909 
5910 /* @(#) $Id: zlib.c,v 1.23 2006/01/14 18:58:05 christos Exp $ */
5911 
5912 /* #include "zlib.h" */
5913 
5914 #define BASE 65521L /* largest prime smaller than 65536 */
5915 #define NMAX 5552
5916 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5917 
5918 #define DO1(buf,i)  {s1 += buf[i]; s2 += s1;}
5919 #define DO2(buf,i)  DO1(buf,i); DO1(buf,i+1);
5920 #define DO4(buf,i)  DO2(buf,i); DO2(buf,i+2);
5921 #define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);
5922 #define DO16(buf)   DO8(buf,0); DO8(buf,8);
5923 
5924 /* ========================================================================= */
5925 uLong ZEXPORT adler32(adler, buf, len)
5926     uLong adler;
5927     const Bytef *buf;
5928     uInt len;
5929 {
5930     unsigned long s1 = adler & 0xffff;
5931     unsigned long s2 = (adler >> 16) & 0xffff;
5932     int k;
5933 
5934     if (buf == Z_NULL) return 1L;
5935 
5936     while (len > 0) {
5937         k = len < NMAX ? len : NMAX;
5938         len -= k;
5939         while (k >= 16) {
5940             DO16(buf);
5941 	    buf += 16;
5942             k -= 16;
5943         }
5944         if (k != 0) do {
5945             s1 += *buf++;
5946 	    s2 += s1;
5947         } while (--k);
5948         s1 %= BASE;
5949         s2 %= BASE;
5950     }
5951     return (s2 << 16) | s1;
5952 }
5953 /* --- adler32.c */
5954 
5955