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      1 /*
      2  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
      3  * Use is subject to license terms.
      4  */
      5 
      6 /*
      7  * Updated from zlib-1.0.4 to zlib-1.1.3 by James Carlson.
      8  *
      9  * This file is derived from various .h and .c files from the zlib-1.0.4
     10  * distribution by Jean-loup Gailly and Mark Adler, with some additions
     11  * by Paul Mackerras to aid in implementing Deflate compression and
     12  * decompression for PPP packets.  See zlib.h for conditions of
     13  * distribution and use.
     14  *
     15  * Changes that have been made include:
     16  * - added Z_PACKET_FLUSH (see zlib.h for details)
     17  * - added inflateIncomp and deflateOutputPending
     18  * - allow strm->next_out to be NULL, meaning discard the output
     19  *
     20  * $Id: zlib.c,v 1.11 1998/09/13 23:37:12 paulus Exp $
     21  */
     22 
     23 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     24 
     25 /*
     26  *  ==FILEVERSION 971210==
     27  *
     28  * This marker is used by the Linux installation script to determine
     29  * whether an up-to-date version of this file is already installed.
     30  */
     31 
     32 #define	NO_DUMMY_DECL
     33 #define	NO_ZCFUNCS
     34 #define	MY_ZCALLOC
     35 
     36 #if defined(__FreeBSD__) && (defined(KERNEL) || defined(_KERNEL))
     37 #define	inflate	inflate_ppp	/* FreeBSD already has an inflate :-( */
     38 #endif
     39 
     40 
     41 /* +++ zutil.h */
     42 /*
     43  *
     44  * zutil.h -- internal interface and configuration of the compression library
     45  * Copyright (C) 1995-1998 Jean-loup Gailly.
     46  * For conditions of distribution and use, see copyright notice in zlib.h
     47  */
     48 
     49 /*
     50  * WARNING: this file should *not* be used by applications. It is part
     51  * of the implementation of the compression library and is subject to
     52  * change. Applications should only use zlib.h.
     53  */
     54 
     55 /* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */
     56 
     57 #ifndef _Z_UTIL_H
     58 #define	_Z_UTIL_H
     59 
     60 #include "zlib.h"
     61 
     62 #if defined(KERNEL) || defined(_KERNEL)
     63 /* Assume this is a *BSD or SVR4 kernel */
     64 #include <sys/types.h>
     65 #include <sys/time.h>
     66 #include <sys/systm.h>
     67 #ifdef SOL2
     68 #include <sys/cmn_err.h>
     69 #endif
     70 #define	HAVE_MEMCPY
     71 #define	memcmp		bcmp
     72 
     73 #else
     74 #if defined(__KERNEL__)
     75 /* Assume this is a Linux kernel */
     76 #include <linux/string.h>
     77 #define	HAVE_MEMCPY
     78 
     79 #else /* not kernel */
     80 
     81 #include <stddef.h>
     82 #ifdef NO_ERRNO_H
     83 extern int errno;
     84 #else
     85 #include <errno.h>
     86 #endif
     87 #ifdef STDC
     88 #include <string.h>
     89 #include <stdlib.h>
     90 #endif
     91 #endif /* __KERNEL__ */
     92 #endif /* _KERNEL || KERNEL */
     93 
     94 #ifndef local
     95 #define	local static
     96 #endif
     97 /* compile with -Dlocal if your debugger can't find static symbols */
     98 
     99 typedef unsigned char  uch;
    100 typedef uch FAR uchf;
    101 typedef unsigned short ush;
    102 typedef ush FAR ushf;
    103 typedef unsigned long  ulg;
    104 
    105 static const char *z_errmsg[10]; /* indexed by 2-zlib_error */
    106 /* (size given to avoid silly warnings with Visual C++) */
    107 
    108 #define	ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
    109 
    110 #define	ERR_RETURN(strm, err) \
    111 	return (strm->msg = ERR_MSG(err), (err))
    112 /* To be used only when the state is known to be valid */
    113 
    114 	/* common constants */
    115 
    116 #ifndef DEF_WBITS
    117 #define	DEF_WBITS MAX_WBITS
    118 #endif
    119 /* default windowBits for decompression. MAX_WBITS is for compression only */
    120 
    121 #if MAX_MEM_LEVEL >= 8
    122 #define	DEF_MEM_LEVEL 8
    123 #else
    124 #define	DEF_MEM_LEVEL  MAX_MEM_LEVEL
    125 #endif
    126 /* default memLevel */
    127 
    128 #define	STORED_BLOCK 0
    129 #define	STATIC_TREES 1
    130 #define	DYN_TREES    2
    131 /* The three kinds of block type */
    132 
    133 #define	MIN_MATCH  3
    134 #define	MAX_MATCH  258
    135 /* The minimum and maximum match lengths */
    136 
    137 #define	PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
    138 
    139 	/* target dependencies */
    140 
    141 #ifdef MSDOS
    142 #define	OS_CODE  0x00
    143 #ifdef __TURBOC__
    144 #include <alloc.h>
    145 #else /* MSC or DJGPP */
    146 #include <malloc.h>
    147 #endif
    148 #endif
    149 
    150 #ifdef OS2
    151 #define	OS_CODE  0x06
    152 #endif
    153 
    154 #ifdef WIN32 /* Window 95 & Windows NT */
    155 #define	OS_CODE  0x0b
    156 #endif
    157 
    158 #if defined(VAXC) || defined(VMS)
    159 #define	OS_CODE  0x02
    160 #define	F_OPEN(name, mode) \
    161 	fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
    162 #endif
    163 
    164 #ifdef AMIGA
    165 #define	OS_CODE  0x01
    166 #endif
    167 
    168 #if defined(ATARI) || defined(atarist)
    169 #define	OS_CODE  0x05
    170 #endif
    171 
    172 #ifdef MACOS
    173 #define	OS_CODE  0x07
    174 #endif
    175 
    176 #ifdef __50SERIES /* Prime/PRIMOS */
    177 #define	OS_CODE  0x0F
    178 #endif
    179 
    180 #ifdef TOPS20
    181 #define	OS_CODE  0x0a
    182 #endif
    183 
    184 #if defined(_BEOS_) || defined(RISCOS)
    185 #define	fdopen(fd, mode) NULL /* No fdopen() */
    186 #endif
    187 
    188 	/* Common defaults */
    189 
    190 #ifndef OS_CODE
    191 #define	OS_CODE  0x03  /* assume Unix */
    192 #endif
    193 
    194 #ifndef F_OPEN
    195 #define	F_OPEN(name, mode) fopen((name), (mode))
    196 #endif
    197 
    198 	/* functions */
    199 
    200 #ifdef HAVE_STRERROR
    201 extern char *strerror OF((int));
    202 #define	zstrerror(errnum) strerror(errnum)
    203 #else
    204 #define	zstrerror(errnum) ""
    205 #endif
    206 
    207 #if defined(pyr)
    208 #define	NO_MEMCPY
    209 #endif
    210 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
    211 /*
    212  * Use our own functions for small and medium model with MSC <= 5.0.
    213  * You may have to use the same strategy for Borland C (untested).
    214  */
    215 #define	NO_MEMCPY
    216 #endif
    217 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
    218 #define	HAVE_MEMCPY
    219 #endif
    220 #ifdef HAVE_MEMCPY
    221 #ifdef SMALL_MEDIUM /* MSDOS small or medium model */
    222 #define	zmemcpy _fmemcpy
    223 #define	zmemcmp _fmemcmp
    224 #define	zmemzero(dest, len) _fmemset(dest, 0, len)
    225 #else
    226 #define	zmemcpy (void) memcpy
    227 #define	zmemcmp memcmp
    228 #define	zmemzero(dest, len) (void) memset(dest, 0, len)
    229 #endif
    230 #else
    231 extern void zmemcpy  OF((Bytef* dest, const Bytef* source, uInt len));
    232 extern int  zmemcmp  OF((const Bytef* s1, const Bytef* s2, uInt len));
    233 extern void zmemzero OF((Bytef* dest, uInt len));
    234 #endif
    235 
    236 /* Diagnostic functions */
    237 #ifdef DEBUG_ZLIB
    238 #include <stdio.h>
    239 #ifndef verbose
    240 #define	verbose 0
    241 #endif
    242 extern void z_error    OF((char *m));
    243 #define	Assert(cond, msg) { if (!(cond)) z_error(msg); }
    244 #define	Trace(x) {if (z_verbose >= 0) fprintf x; }
    245 #define	Tracev(x) {if (z_verbose > 0) fprintf x; }
    246 #define	Tracevv(x) {if (z_verbose > 1) fprintf x; }
    247 #define	Tracec(c, x) {if (z_verbose > 0 && (c)) fprintf x; }
    248 #define	Tracecv(c, x) {if (z_verbose > 1 && (c)) fprintf x; }
    249 #else
    250 #if defined(SOL2) && defined(DEBUG)
    251 #define	Assert(cond, msg)	((cond) ? ((void)0) : panic(msg))
    252 #else
    253 #define	Assert(cond, msg)	((void)0)
    254 #endif
    255 #define	Trace(x)	((void)0)
    256 #define	Tracev(x)	((void)0)
    257 #define	Tracevv(x)	((void)0)
    258 #define	Tracec(c, x)	((void)0)
    259 #define	Tracecv(c, x)	((void)0)
    260 #endif
    261 
    262 
    263 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));
    264 
    265 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
    266 /* void   zcfree  OF((voidpf opaque, voidpf ptr)); */
    267 
    268 #define	ZALLOC(strm, items, size) \
    269 	(*((strm)->zalloc))((strm)->opaque, (items), (size))
    270 #define	ZFREE(strm, addr)  (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
    271 #define	TRY_FREE(s, p) {if (p) ZFREE(s, p); }
    272 
    273 #endif /* _Z_UTIL_H */
    274 /* --- zutil.h */
    275 
    276 /* +++ deflate.h */
    277 /*
    278  * deflate.h -- internal compression state
    279  * Copyright (C) 1995-1998 Jean-loup Gailly
    280  * For conditions of distribution and use, see copyright notice in zlib.h
    281  */
    282 
    283 /*
    284  * WARNING: this file should *not* be used by applications. It is part
    285  * of the implementation of the compression library and is subject to
    286  * change. Applications should only use zlib.h.
    287  */
    288 
    289 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */
    290 
    291 #ifndef _DEFLATE_H
    292 #define	_DEFLATE_H
    293 
    294 /* #include "zutil.h" */
    295 
    296 /*
    297  * ===========================================================================
    298  * Internal compression state.
    299  */
    300 
    301 #define	LENGTH_CODES 29
    302 /* number of length codes, not counting the special END_BLOCK code */
    303 
    304 #define	LITERALS  256
    305 /* number of literal bytes 0..255 */
    306 
    307 #define	L_CODES (LITERALS+1+LENGTH_CODES)
    308 /* number of Literal or Length codes, including the END_BLOCK code */
    309 
    310 #define	D_CODES   30
    311 /* number of distance codes */
    312 
    313 #define	BL_CODES  19
    314 /* number of codes used to transfer the bit lengths */
    315 
    316 #define	HEAP_SIZE (2*L_CODES+1)
    317 /* maximum heap size */
    318 
    319 #define	MAX_BITS 15
    320 /* All codes must not exceed MAX_BITS bits */
    321 
    322 #define	INIT_STATE    42
    323 #define	BUSY_STATE   113
    324 #define	FINISH_STATE 666
    325 /* Stream status */
    326 
    327 
    328 /* Data structure describing a single value and its code string. */
    329 typedef struct ct_data_s {
    330 	union {
    331 		ush freq;	/* frequency count */
    332 		ush code;	/* bit string */
    333 	} fc;
    334 	union {
    335 		ush dad;	/* father node in Huffman tree */
    336 		ush len;	/* length of bit string */
    337 	} dl;
    338 } FAR ct_data;
    339 
    340 #define	Freq fc.freq
    341 #define	Code fc.code
    342 #define	Dad  dl.dad
    343 #define	Len  dl.len
    344 
    345 typedef struct static_tree_desc_s  static_tree_desc;
    346 
    347 typedef struct tree_desc_s {
    348 	ct_data *dyn_tree;	/* the dynamic tree */
    349 	int	max_code;	/* largest code with non zero frequency */
    350 	static_tree_desc *stat_desc;	/* the corresponding static tree */
    351 } FAR tree_desc;
    352 
    353 typedef ush Pos;
    354 typedef Pos FAR Posf;
    355 typedef unsigned IPos;
    356 
    357 /*
    358  * A Pos is an index in the character window. We use short instead of
    359  * int to save space in the various tables. IPos is used only for
    360  * parameter passing.
    361  */
    362 
    363 typedef struct deflate_state {
    364 	z_streamp strm;	/* pointer back to this zlib stream */
    365 	int   status;	/* as the name implies */
    366 	Bytef *pending_buf;	/* output still pending */
    367 	ulg   pending_buf_size;	/* size of pending_buf */
    368 	Bytef *pending_out;	/* next pending byte to output to the stream */
    369 	int   pending;	/* nb of bytes in the pending buffer */
    370 	int   noheader;	/* suppress zlib header and adler32 */
    371 	Byte  data_type;	/* UNKNOWN, BINARY or ASCII */
    372 	Byte  method;	/* STORED (for zip only) or DEFLATED */
    373 	/* value of flush param for previous deflate call */
    374 	int   last_flush;
    375 
    376 	/* used by deflate.c: */
    377 
    378 	uInt  w_size;	/* LZ77 window size (32K by default) */
    379 	uInt  w_bits;	/* log2(w_size)  (8..16) */
    380 	uInt  w_mask;	/* w_size - 1 */
    381 
    382 	Bytef *window;
    383 	/*
    384 	 * Sliding window. Input bytes are read into the second half
    385 	 * of the window, and move to the first half later to keep a
    386 	 * dictionary of at least wSize bytes. With this organization,
    387 	 * matches are limited to a distance of wSize-MAX_MATCH bytes,
    388 	 * but this ensures that IO is always performed with a length
    389 	 * multiple of the block size. Also, it limits the window size
    390 	 * to 64K, which is quite useful on MSDOS.  To do: use the
    391 	 * user input buffer as sliding window.
    392 	 */
    393 
    394 	ulg window_size;
    395 	/*
    396 	 * Actual size of window: 2*wSize, except when the user input
    397 	 * buffer is directly used as sliding window.
    398 	 */
    399 
    400 	Posf *prev;
    401 	/*
    402 	 * Link to older string with same hash index. To limit the
    403 	 * size of this array to 64K, this link is maintained only for
    404 	 * the last 32K strings.  An index in this array is thus a
    405 	 * 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 	/*
    417 	 * Number of bits by which ins_h must be shifted at each input
    418 	 * step. It must be such that after MIN_MATCH steps, the
    419 	 * oldest byte no longer takes part in the hash key, that is:
    420 	 * hash_shift * MIN_MATCH >= hash_bits
    421 	 */
    422 
    423 	long block_start;
    424 	/*
    425 	 * Window position at the beginning of the current output
    426 	 * block. Gets negative when the window is moved backwards.
    427 	 */
    428 
    429 	uInt match_length;	/* length of best match */
    430 	IPos prev_match;	/* previous match */
    431 	int match_available;	/* set if previous match exists */
    432 	uInt strstart;	/* start of string to insert */
    433 	uInt match_start;	/* start of matching string */
    434 	uInt lookahead;	/* number of valid bytes ahead in window */
    435 
    436 	uInt prev_length;
    437 	/*
    438 	 * Length of the best match at previous step. Matches not
    439 	 * greater than this are discarded. This is used in the lazy
    440 	 * match evaluation.
    441 	 */
    442 
    443 	uInt max_chain_length;
    444 	/*
    445 	 * To speed up deflation, hash chains are never searched
    446 	 * beyond *this length.  A higher limit improves compression
    447 	 * ratio but *degrades the speed.
    448 	 */
    449 
    450 	uInt max_lazy_match;
    451 	/*
    452 	 * Attempt to find a better match only when the current match
    453 	 * is strictly smaller than this value. This mechanism is used
    454 	 * only for compression levels >= 4.
    455 	 */
    456 #define	max_insert_length  max_lazy_match
    457 	/*
    458 	 * Insert new strings in the hash table only if the match
    459 	 * length is not greater than this length. This saves time but
    460 	 * degrades compression.  max_insert_length is used only for
    461 	 * compression levels <= 3.
    462 	 */
    463 
    464 	int level;	/* compression level (1..9) */
    465 	int strategy;	/* favor or force Huffman coding */
    466 
    467 	uInt good_match;
    468 	/* Use a faster search when the previous match is longer than this */
    469 
    470 	int nice_match;	/* Stop searching when current match exceeds this */
    471 
    472 	/* used by trees.c: */
    473 	/* Didn't use ct_data typedef below to supress compiler warning */
    474 	struct ct_data_s dyn_ltree[HEAP_SIZE];	/* literal and length tree */
    475 	struct ct_data_s dyn_dtree[2*D_CODES+1];	/* distance tree */
    476 	/* Huffman tree for bit lengths */
    477 	struct ct_data_s bl_tree[2*BL_CODES+1];
    478 
    479 	struct tree_desc_s l_desc;	/* desc. for literal tree */
    480 	struct tree_desc_s d_desc;	/* desc. for distance tree */
    481 	struct tree_desc_s bl_desc;	/* desc. for bit length tree */
    482 
    483 	ush bl_count[MAX_BITS+1];
    484 	/* number of codes at each bit length for an optimal tree */
    485 
    486 	int heap[2*L_CODES+1];	/* heap used to build the Huffman trees */
    487 	int heap_len;	/* number of elements in the heap */
    488 	int heap_max;	/* element of largest frequency */
    489 	/*
    490 	 * The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0]
    491 	 * is not used.  The same heap array is used to build all
    492 	 * trees.
    493 	 */
    494 
    495 	uch depth[2*L_CODES+1];
    496 	/*
    497 	 * Depth of each subtree used as tie breaker for trees of
    498 	 * equal frequency
    499 	 */
    500 
    501 	uchf *l_buf;	/* buffer for literals or lengths */
    502 
    503 	uInt lit_bufsize;
    504 	/*
    505 	 * Size of match buffer for literals/lengths.  There are 4
    506 	 * reasons for limiting lit_bufsize to 64K:
    507 	 *
    508 	 *   - frequencies can be kept in 16 bit counters
    509 	 *
    510 	 *   - if compression is not successful for the first block,
    511 	 *   all input data is still in the window so we can still
    512 	 *   emit a stored block even when input comes from standard
    513 	 *   input.  (This can also be done for all blocks if
    514 	 *   lit_bufsize is not greater than 32K.)
    515 	 *
    516 	 *   - if compression is not successful for a file smaller
    517 	 *   than 64K, we can even emit a stored file instead of a
    518 	 *   stored block (saving 5 bytes).  This is applicable only
    519 	 *   for zip (not gzip or zlib).
    520 	 *
    521 	 *   - creating new Huffman trees less frequently may not
    522 	 *   provide fast adaptation to changes in the input data
    523 	 *   statistics. (Take for example a binary file with poorly
    524 	 *   compressible code followed by a highly compressible
    525 	 *   string table.) Smaller buffer sizes give fast adaptation
    526 	 *   but have of course the overhead of transmitting trees
    527 	 *   more frequently.
    528 	 *
    529 	 *   - I can't count above 4
    530 	 */
    531 
    532 	uInt last_lit;	/* running index in l_buf */
    533 
    534 	ushf *d_buf;
    535 	/*
    536 	 * Buffer for distances. To simplify the code, d_buf and l_buf
    537 	 * have the same number of elements. To use different lengths,
    538 	 * an extra flag array would be necessary.
    539 	 */
    540 
    541 	ulg opt_len;	/* bit length of current block with optimal trees */
    542 	ulg static_len;	/* bit length of current block with static trees */
    543 	uInt matches;	/* number of string matches in current block */
    544 	int last_eob_len;	/* bit length of EOB code for last block */
    545 
    546 	ulg compressed_len;	/* total bit length of compressed file PPP */
    547 #ifdef DEBUG_ZLIB
    548 	ulg bits_sent;	/* bit length of the compressed data */
    549 #endif
    550 
    551 	ush bi_buf;
    552 	/*
    553 	 * Output buffer. bits are inserted starting at the bottom
    554 	 * (least significant bits).
    555 	 */
    556 	int bi_valid;
    557 	/*
    558 	 * Number of valid bits in bi_buf.  All bits above the last
    559 	 * valid bit are always zero.
    560 	 */
    561 
    562 } FAR deflate_state;
    563 
    564 /*
    565  * Output a byte on the stream.  IN assertion: there is enough room in
    566  * pending_buf.
    567  */
    568 #define	put_byte(s, c) {s->pending_buf[s->pending++] = (c); }
    569 
    570 
    571 #define	MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
    572 /*
    573  * Minimum amount of lookahead, except at the end of the input file.
    574  * See deflate.c for comments about the MIN_MATCH+1.
    575  */
    576 
    577 #define	MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
    578 /*
    579  * In order to simplify the code, particularly on 16 bit machines,
    580  * match distances are limited to MAX_DIST instead of WSIZE.
    581  */
    582 
    583 	/* in trees.c */
    584 void _tr_init		OF((deflate_state *s));
    585 int  _tr_tally		OF((deflate_state *s, unsigned dist, unsigned lc));
    586 void  _tr_flush_block	OF((deflate_state *s, charf *buf, ulg stored_len,
    587     int eof));
    588 void _tr_align		OF((deflate_state *s));
    589 void _tr_stored_block	OF((deflate_state *s, charf *buf, ulg stored_len,
    590     int eof));
    591 void _tr_stored_type_only OF((deflate_state *));	/* PPP */
    592 
    593 #define	d_code(dist) \
    594 	((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
    595 /*
    596  * Mapping from a distance to a distance code. dist is the distance - 1 and
    597  * must not have side effects. _dist_code[256] and _dist_code[257] are never
    598  * used.
    599  */
    600 
    601 #ifndef DEBUG_ZLIB
    602 /* Inline versions of _tr_tally for speed: */
    603 
    604 local uch _length_code[];
    605 local uch _dist_code[];
    606 
    607 #define	_tr_tally_lit(s, c, flush) \
    608 	{	uch cc = (c); \
    609 		s->d_buf[s->last_lit] = 0; \
    610 		s->l_buf[s->last_lit++] = cc; \
    611 		s->dyn_ltree[cc].Freq++; \
    612 		flush = (s->last_lit == s->lit_bufsize-1); \
    613 	}
    614 #define	_tr_tally_dist(s, distance, length, flush) \
    615 	{	uch len = (length); \
    616 		ush dist = (distance); \
    617 		s->d_buf[s->last_lit] = dist; \
    618 		s->l_buf[s->last_lit++] = len; \
    619 		dist--; \
    620 		s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
    621 		s->dyn_dtree[d_code(dist)].Freq++; \
    622 		flush = (s->last_lit == s->lit_bufsize-1); \
    623 	}
    624 #else
    625 #define	_tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
    626 #define	_tr_tally_dist(s, distance, length, flush) \
    627 		flush = _tr_tally(s, distance, length)
    628 #endif
    629 
    630 #endif
    631 /* --- deflate.h */
    632 
    633 /* +++ deflate.c */
    634 /*
    635  * deflate.c -- compress data using the deflation algorithm
    636  * Copyright (C) 1995-1998 Jean-loup Gailly.
    637  * For conditions of distribution and use, see copyright notice in zlib.h
    638  */
    639 
    640 /*
    641  *  ALGORITHM
    642  *
    643  *      The "deflation" process depends on being able to identify portions
    644  *      of the input text which are identical to earlier input (within a
    645  *      sliding window trailing behind the input currently being processed).
    646  *
    647  *      The most straightforward technique turns out to be the fastest for
    648  *      most input files: try all possible matches and select the longest.
    649  *      The key feature of this algorithm is that insertions into the string
    650  *      dictionary are very simple and thus fast, and deletions are avoided
    651  *      completely. Insertions are performed at each input character, whereas
    652  *      string matches are performed only when the previous match ends. So it
    653  *      is preferable to spend more time in matches to allow very fast string
    654  *      insertions and avoid deletions. The matching algorithm for small
    655  *      strings is inspired from that of Rabin & Karp. A brute force approach
    656  *      is used to find longer strings when a small match has been found.
    657  *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
    658  *      (by Leonid Broukhis).
    659  *         A previous version of this file used a more sophisticated algorithm
    660  *      (by Fiala and Greene) which is guaranteed to run in linear amortized
    661  *      time, but has a larger average cost, uses more memory and is patented.
    662  *      However the F&G algorithm may be faster for some highly redundant
    663  *      files if the parameter max_chain_length (described below) is too large.
    664  *
    665  *  ACKNOWLEDGEMENTS
    666  *
    667  *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
    668  *      I found it in 'freeze' written by Leonid Broukhis.
    669  *      Thanks to many people for bug reports and testing.
    670  *
    671  *  REFERENCES
    672  *
    673  *      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
    674  *      Available in ftp://ds.internic.net/rfc/rfc1951.txt
    675  *
    676  *      A description of the Rabin and Karp algorithm is given in the book
    677  *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
    678  *
    679  *      Fiala,E.R., and Greene,D.H.
    680  *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
    681  *
    682  */
    683 
    684 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */
    685 
    686 /* #include "deflate.h" */
    687 
    688 const char deflate_copyright[] =
    689 " deflate 1.1.3 Copyright 1995-1998 Jean-loup Gailly ";
    690 /*
    691  * If you use the zlib library in a product, an acknowledgment is
    692  * welcome in the documentation of your product. If for some reason
    693  * you cannot include such an acknowledgment, I would appreciate that
    694  * you keep this copyright string in the executable of your product.
    695  */
    696 
    697 /*
    698  * ===========================================================================
    699  *  Function prototypes.
    700  */
    701 typedef enum {
    702 	/* block not completed, need more input or more output */
    703 	need_more,
    704 	block_done,	/* block flush performed */
    705 	/* finish started, need only more output at next deflate */
    706 	finish_started,
    707 	finish_done	/* finish done, accept no more input or output */
    708 } block_state;
    709 
    710 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
    711 /* Compression function. Returns the block state after the call. */
    712 
    713 local void fill_window	OF((deflate_state *s));
    714 local block_state deflate_stored OF((deflate_state *s, int flush));
    715 local block_state deflate_fast	OF((deflate_state *s, int flush));
    716 local block_state deflate_slow	OF((deflate_state *s, int flush));
    717 local void lm_init	OF((deflate_state *s));
    718 local void putShortMSB	OF((deflate_state *s, uInt b));
    719 local void flush_pending	OF((z_streamp strm));
    720 local int read_buf	OF((z_streamp strm, Bytef *buf, unsigned size));
    721 #ifdef ASMV
    722 void match_init	OF((void));	/* asm code initialization */
    723 uInt longest_match	OF((deflate_state *s, IPos cur_match));
    724 #else
    725 local uInt longest_match	OF((deflate_state *s, IPos cur_match));
    726 #endif
    727 
    728 #ifdef DEBUG_ZLIB
    729 local void check_match OF((deflate_state *s, IPos start, IPos match,
    730     int length));
    731 #endif
    732 
    733 /*
    734  * ===========================================================================
    735  * Local data
    736  */
    737 
    738 #define	NIL 0
    739 /* Tail of hash chains */
    740 
    741 #ifndef TOO_FAR
    742 #define	TOO_FAR 4096
    743 #endif
    744 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
    745 
    746 #define	MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
    747 /*
    748  * Minimum amount of lookahead, except at the end of the input file.
    749  * See deflate.c for comments about the MIN_MATCH+1.
    750  */
    751 
    752 /*
    753  * Values for max_lazy_match, good_match and max_chain_length,
    754  * depending on the desired pack level (0..9). The values given below
    755  * have been tuned to exclude worst case performance for pathological
    756  * files. Better values may be found for specific files.
    757  */
    758 typedef struct config_s {
    759 	ush good_length;	/* reduce lazy search above this match length */
    760 	ush max_lazy;	/* do not perform lazy search above this match length */
    761 	ush nice_length;	/* quit search above this match length */
    762 	ush max_chain;
    763 	compress_func func;
    764 } config;
    765 
    766 local const config configuration_table[10] = {
    767 /*	good lazy nice chain */
    768 /* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
    769 /* 1 */ {4,    4,  8,    4, deflate_fast}, /* maximum speed, no lazy matches */
    770 /* 2 */ {4,    5, 16,    8, deflate_fast},
    771 /* 3 */ {4,    6, 32,   32, deflate_fast},
    772 
    773 /* 4 */ {4,    4, 16,   16, deflate_slow},  /* lazy matches */
    774 /* 5 */ {8,   16, 32,   32, deflate_slow},
    775 /* 6 */ {8,   16, 128, 128, deflate_slow},
    776 /* 7 */ {8,   32, 128, 256, deflate_slow},
    777 /* 8 */ {32, 128, 258, 1024, deflate_slow},
    778 /* 9 */ {32, 258, 258, 4096, deflate_slow}};	/* maximum compression */
    779 
    780 /*
    781  * Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
    782  * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
    783  * meaning.
    784  */
    785 
    786 #define	EQUAL 0
    787 /* result of memcmp for equal strings */
    788 
    789 #ifndef NO_DUMMY_DECL
    790 struct static_tree_desc_s {int dummy; };	/* for buggy compilers */
    791 #endif
    792 
    793 /*
    794  * ===========================================================================
    795  * Update a hash value with the given input byte
    796  * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
    797  *    input characters, so that a running hash key can be computed from the
    798  *    previous key instead of complete recalculation each time.
    799  */
    800 #define	UPDATE_HASH(s, h, c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
    801 
    802 
    803 /*
    804  * ===========================================================================
    805  * Insert string str in the dictionary and set match_head to the previous head
    806  * of the hash chain (the most recent string with same hash key). Return
    807  * the previous length of the hash chain.
    808  * If this file is compiled with -DFASTEST, the compression level is forced
    809  * to 1, and no hash chains are maintained.
    810  * IN  assertion: all calls to to INSERT_STRING are made with consecutive
    811  *    input characters and the first MIN_MATCH bytes of str are valid
    812  *    (except for the last MIN_MATCH-1 bytes of the input file).
    813  */
    814 #ifdef FASTEST
    815 #define	INSERT_STRING(s, str, match_head) \
    816 	(UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
    817 	match_head = s->head[s->ins_h], \
    818 	s->head[s->ins_h] = (Pos)(str))
    819 #else
    820 #define	INSERT_STRING(s, str, match_head) \
    821 	(UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
    822 	s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
    823 	s->head[s->ins_h] = (Pos)(str))
    824 #endif
    825 
    826 /*
    827  * ===========================================================================
    828  * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
    829  * prev[] will be initialized on the fly.
    830  */
    831 #define	CLEAR_HASH(s) \
    832     s->head[s->hash_size-1] = NIL; \
    833     zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof (*s->head));
    834 
    835 /* ========================================================================= */
    836 int
    837 deflateInit_(strm, level, version, stream_size)
    838     z_streamp strm;
    839     int level;
    840     const char *version;
    841     int stream_size;
    842 {
    843 	(void) deflate_copyright;
    844 	return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
    845 	    Z_DEFAULT_STRATEGY, version, stream_size);
    846 	/* To do: ignore strm->next_in if we use it as window */
    847 }
    848 
    849 /* ========================================================================= */
    850 int deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
    851     version, stream_size)
    852     z_streamp strm;
    853     int  level;
    854     int  method;
    855     int  windowBits;
    856     int  memLevel;
    857     int  strategy;
    858     const char *version;
    859     int stream_size;
    860 {
    861 	deflate_state *s;
    862 	int noheader = 0;
    863 	static const char *my_version = ZLIB_VERSION;
    864 
    865 	ushf *overlay;
    866 	/*
    867 	 * We overlay pending_buf and d_buf+l_buf. This works since
    868 	 * the average output size for (length, distance) codes is <=
    869 	 * 24 bits.
    870 	 */
    871 
    872 	if (version == Z_NULL || version[0] != my_version[0] ||
    873 	    stream_size != sizeof (z_stream)) {
    874 		return (Z_VERSION_ERROR);
    875 	}
    876 	if (strm == Z_NULL)
    877 		return (Z_STREAM_ERROR);
    878 
    879 	strm->msg = Z_NULL;
    880 #ifndef NO_ZCFUNCS
    881 	if (strm->zalloc == Z_NULL) {
    882 		strm->zalloc = zcalloc;
    883 		strm->opaque = (voidpf)0;
    884 	}
    885 	if (strm->zfree == Z_NULL) strm->zfree = zcfree;
    886 #endif
    887 
    888 	if (level == Z_DEFAULT_COMPRESSION) level = 6;
    889 #ifdef FASTEST
    890 	level = 1;
    891 #endif
    892 
    893 	if (windowBits < 0) { /* undocumented feature: suppress zlib header */
    894 		noheader = 1;
    895 		windowBits = -windowBits;
    896 	}
    897 	if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
    898 	    windowBits <= 8 || windowBits > 15 || level < 0 || level > 9 ||
    899 	    strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
    900 		return (Z_STREAM_ERROR);
    901 	}
    902 	s = (deflate_state *) ZALLOC(strm, 1, sizeof (deflate_state));
    903 	if (s == Z_NULL)
    904 		return (Z_MEM_ERROR);
    905 	strm->state = (struct internal_state FAR *)s;
    906 	s->strm = strm;
    907 
    908 	s->noheader = noheader;
    909 	s->w_bits = windowBits;
    910 	s->w_size = 1 << s->w_bits;
    911 	s->w_mask = s->w_size - 1;
    912 
    913 	s->hash_bits = memLevel + 7;
    914 	s->hash_size = 1 << s->hash_bits;
    915 	s->hash_mask = s->hash_size - 1;
    916 	s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
    917 
    918 	s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof (Byte));
    919 	s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof (Pos));
    920 	s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof (Pos));
    921 
    922 	s->lit_bufsize = 1 << (memLevel + 6);	/* 16K elements by default */
    923 
    924 	overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof (ush)+2);
    925 	s->pending_buf = (uchf *) overlay;
    926 	s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof (ush)+2L);
    927 
    928 	if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
    929 	    s->pending_buf == Z_NULL) {
    930 		strm->msg = ERR_MSG(Z_MEM_ERROR);
    931 		s->status = INIT_STATE;
    932 		(void) deflateEnd(strm);
    933 		return (Z_MEM_ERROR);
    934 	}
    935 	s->d_buf = overlay + s->lit_bufsize/sizeof (ush);
    936 	s->l_buf = s->pending_buf + (1+sizeof (ush))*s->lit_bufsize;
    937 
    938 	s->level = level;
    939 	s->strategy = strategy;
    940 	s->method = (Byte)method;
    941 
    942 	return (deflateReset(strm));
    943 }
    944 
    945 /* ========================================================================= */
    946 int
    947 deflateSetDictionary(strm, dictionary, dictLength)
    948     z_streamp strm;
    949     const Bytef *dictionary;
    950     uInt  dictLength;
    951 {
    952 	deflate_state *s;
    953 	uInt length = dictLength;
    954 	uInt n;
    955 	IPos hash_head = 0;
    956 
    957 	if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
    958 		return (Z_STREAM_ERROR);
    959 
    960 	s = (deflate_state *) strm->state;
    961 	if (s->status != INIT_STATE)
    962 		return (Z_STREAM_ERROR);
    963 
    964 	strm->adler = adler32(strm->adler, dictionary, dictLength);
    965 
    966 	if (length < MIN_MATCH)
    967 		return (Z_OK);
    968 	if (length > MAX_DIST(s)) {
    969 		length = MAX_DIST(s);
    970 #ifndef USE_DICT_HEAD
    971 		/* use the tail of the dictionary */
    972 		dictionary += dictLength - length;
    973 #endif
    974 	}
    975 	Assert(length <= s->window_size, "dict copy");
    976 	zmemcpy(s->window, dictionary, length);
    977 	s->strstart = length;
    978 	s->block_start = (long)length;
    979 
    980 	/*
    981 	 * Insert all strings in the hash table (except for the last
    982 	 * two bytes).  s->lookahead stays null, so s->ins_h will be
    983 	 * recomputed at the next call of fill_window.
    984 	 */
    985 	s->ins_h = s->window[0];
    986 	UPDATE_HASH(s, s->ins_h, s->window[1]);
    987 	for (n = 0; n <= length - MIN_MATCH; n++) {
    988 		INSERT_STRING(s, n, hash_head);
    989 	}
    990 	if (hash_head) hash_head = 0;	/* to make compiler happy */
    991 	return (Z_OK);
    992 }
    993 
    994 /* ========================================================================= */
    995 int
    996 deflateReset(strm)
    997     z_streamp strm;
    998 {
    999 	deflate_state *s;
   1000 
   1001 	if (strm == Z_NULL || strm->state == Z_NULL ||
   1002 	    strm->zalloc == Z_NULL || strm->zfree == Z_NULL)
   1003 		return (Z_STREAM_ERROR);
   1004 
   1005 	strm->total_in = strm->total_out = 0;
   1006 	/* use zfree if we ever allocate msg dynamically */
   1007 	strm->msg = Z_NULL;
   1008 	strm->data_type = Z_UNKNOWN;
   1009 
   1010 	s = (deflate_state *)strm->state;
   1011 	s->pending = 0;
   1012 	s->pending_out = s->pending_buf;
   1013 
   1014 	if (s->noheader < 0) {
   1015 		/* was set to -1 by deflate(..., Z_FINISH); */
   1016 		s->noheader = 0;
   1017 	}
   1018 	s->status = s->noheader ? BUSY_STATE : INIT_STATE;
   1019 	strm->adler = 1;
   1020 	s->last_flush = Z_NO_FLUSH;
   1021 
   1022 	_tr_init(s);
   1023 	lm_init(s);
   1024 
   1025 	return (Z_OK);
   1026 }
   1027 
   1028 /* ========================================================================= */
   1029 int
   1030 deflateParams(strm, level, strategy)
   1031     z_streamp strm;
   1032     int level;
   1033     int strategy;
   1034 {
   1035 	deflate_state *s;
   1036 	compress_func func;
   1037 	int err = Z_OK;
   1038 
   1039 	if (strm == Z_NULL || strm->state == Z_NULL)
   1040 		return (Z_STREAM_ERROR);
   1041 	s = (deflate_state *) strm->state;
   1042 
   1043 	if (level == Z_DEFAULT_COMPRESSION) {
   1044 		level = 6;
   1045 	}
   1046 	if (level < 0 || level > 9 || strategy < 0 ||
   1047 	    strategy > Z_HUFFMAN_ONLY) {
   1048 		return (Z_STREAM_ERROR);
   1049 	}
   1050 	func = configuration_table[s->level].func;
   1051 
   1052 	if (func != configuration_table[level].func && strm->total_in != 0) {
   1053 		/* Flush the last buffer: */
   1054 		err = deflate(strm, Z_PARTIAL_FLUSH);
   1055 	}
   1056 	if (s->level != level) {
   1057 		s->level = level;
   1058 		s->max_lazy_match   = configuration_table[level].max_lazy;
   1059 		s->good_match	= configuration_table[level].good_length;
   1060 		s->nice_match	= configuration_table[level].nice_length;
   1061 		s->max_chain_length = configuration_table[level].max_chain;
   1062 	}
   1063 	s->strategy = strategy;
   1064 	return (err);
   1065 }
   1066 
   1067 /*
   1068  * =========================================================================
   1069  * Put a short in the pending buffer. The 16-bit value is put in MSB order.
   1070  * IN assertion: the stream state is correct and there is enough room in
   1071  * pending_buf.
   1072  */
   1073 local void
   1074 putShortMSB(s, b)
   1075     deflate_state *s;
   1076     uInt b;
   1077 {
   1078 	put_byte(s, (Byte)(b >> 8));
   1079 	put_byte(s, (Byte)(b & 0xff));
   1080 }
   1081 
   1082 /*
   1083  * =========================================================================
   1084  * Flush as much pending output as possible. All deflate() output goes
   1085  * through this function so some applications may wish to modify it
   1086  * to avoid allocating a large strm->next_out buffer and copying into it.
   1087  * (See also read_buf()).
   1088  */
   1089 local void
   1090 flush_pending(strm)
   1091     z_streamp strm;
   1092 {
   1093 	deflate_state *s = (deflate_state *) strm->state;
   1094 	unsigned len = s->pending;
   1095 
   1096 	if (len > strm->avail_out) len = strm->avail_out;
   1097 	if (len == 0)
   1098 		return;
   1099 
   1100 	if (strm->next_out != Z_NULL) {		/* PPP */
   1101 		zmemcpy(strm->next_out, s->pending_out, len);
   1102 		strm->next_out += len;
   1103 	}					/* PPP */
   1104 	s->pending_out += len;
   1105 	strm->total_out += len;
   1106 	strm->avail_out  -= len;
   1107 	s->pending -= len;
   1108 	if (s->pending == 0) {
   1109 		s->pending_out = s->pending_buf;
   1110 	}
   1111 }
   1112 
   1113 /* ========================================================================= */
   1114 int
   1115 deflate(strm, flush)
   1116     z_streamp strm;
   1117     int flush;
   1118 {
   1119 	int old_flush;	/* value of flush param for previous deflate call */
   1120 	deflate_state *s;
   1121 
   1122 	if (strm == Z_NULL || strm->state == Z_NULL ||
   1123 	    flush > Z_FINISH || flush < 0) {
   1124 		return (Z_STREAM_ERROR);
   1125 	}
   1126 	s = (deflate_state *) strm->state;
   1127 
   1128 	if (/* strm->next_out == Z_NULL || --- we allow null --- PPP */
   1129 		(strm->next_in == Z_NULL && strm->avail_in != 0) ||
   1130 	    (s->status == FINISH_STATE && flush != Z_FINISH)) {
   1131 		ERR_RETURN(strm, Z_STREAM_ERROR);
   1132 	}
   1133 	if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
   1134 
   1135 	s->strm = strm;	/* just in case */
   1136 	old_flush = s->last_flush;
   1137 	s->last_flush = flush;
   1138 
   1139 	/* Write the zlib header */
   1140 	if (s->status == INIT_STATE) {
   1141 
   1142 		uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
   1143 		uInt level_flags = (s->level-1) >> 1;
   1144 
   1145 		if (level_flags > 3) level_flags = 3;
   1146 		header |= (level_flags << 6);
   1147 		if (s->strstart != 0) header |= PRESET_DICT;
   1148 		header += 31 - (header % 31);
   1149 
   1150 		s->status = BUSY_STATE;
   1151 		putShortMSB(s, header);
   1152 
   1153 		/* Save the adler32 of the preset dictionary: */
   1154 		if (s->strstart != 0) {
   1155 			putShortMSB(s, (uInt)(strm->adler >> 16));
   1156 			putShortMSB(s, (uInt)(strm->adler & 0xffff));
   1157 		}
   1158 		strm->adler = 1L;
   1159 	}
   1160 
   1161 	/* Flush as much pending output as possible */
   1162 	if (s->pending != 0) {
   1163 		flush_pending(strm);
   1164 		if (strm->avail_out == 0) {
   1165 			/*
   1166 			 * Since avail_out is 0, deflate will be
   1167 			 * called again with more output space, but
   1168 			 * possibly with both pending and avail_in
   1169 			 * equal to zero. There won't be anything to
   1170 			 * do, but this is not an error situation so
   1171 			 * make sure we return OK instead of BUF_ERROR
   1172 			 * at next call of deflate:
   1173 			 */
   1174 			s->last_flush = -1;
   1175 			return (Z_OK);
   1176 		}
   1177 
   1178 		/*
   1179 		 * Make sure there is something to do and avoid
   1180 		 * duplicate consecutive flushes. For repeated and
   1181 		 * useless calls with Z_FINISH, we keep returning
   1182 		 * Z_STREAM_END instead of Z_BUFF_ERROR.
   1183 		 */
   1184 	} else if (strm->avail_in == 0 && flush <= old_flush &&
   1185 	    flush != Z_FINISH) {
   1186 		ERR_RETURN(strm, Z_BUF_ERROR);
   1187 	}
   1188 
   1189 	/* User must not provide more input after the first FINISH: */
   1190 	if (s->status == FINISH_STATE && strm->avail_in != 0) {
   1191 		ERR_RETURN(strm, Z_BUF_ERROR);
   1192 	}
   1193 
   1194 	/* Start a new block or continue the current one. */
   1195 	if (strm->avail_in != 0 || s->lookahead != 0 ||
   1196 	    (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
   1197 		block_state bstate;
   1198 
   1199 		bstate = (*(configuration_table[s->level].func))(s, flush);
   1200 
   1201 		if (bstate == finish_started || bstate == finish_done) {
   1202 			s->status = FINISH_STATE;
   1203 		}
   1204 		if (bstate == need_more || bstate == finish_started) {
   1205 			if (strm->avail_out == 0) {
   1206 				/* avoid BUF_ERROR next call, see above */
   1207 				s->last_flush = -1;
   1208 			}
   1209 			return (Z_OK);
   1210 			/*
   1211 			 * If flush != Z_NO_FLUSH && avail_out == 0,
   1212 			 * the next call of deflate should use the
   1213 			 * same flush parameter to make sure that the
   1214 			 * flush is complete. So we don't have to
   1215 			 * output an empty block here, this will be
   1216 			 * done at next call. This also ensures that
   1217 			 * for a very small output buffer, we emit at
   1218 			 * most one empty block.
   1219 			 */
   1220 		}
   1221 		if (bstate == block_done) {
   1222 			if (flush == Z_PARTIAL_FLUSH) {
   1223 				_tr_align(s);
   1224 			} else if (flush == Z_PACKET_FLUSH) {	/* PPP */
   1225 				/*
   1226 				 * Output just the 3-bit `stored'
   1227 				 * block type value, but not a zero
   1228 				 * length.  Added for PPP.
   1229 				 */
   1230 				_tr_stored_type_only(s);	/* PPP */
   1231 			} else { /* FULL_FLUSH or SYNC_FLUSH */
   1232 				_tr_stored_block(s, (char *)0, 0L, 0);
   1233 				/*
   1234 				 * For a full flush, this empty block
   1235 				 * will be recognized as a special
   1236 				 * marker by inflate_sync().
   1237 				 */
   1238 				if (flush == Z_FULL_FLUSH) {
   1239 					CLEAR_HASH(s);	/* forget history */
   1240 				}
   1241 			}
   1242 			flush_pending(strm);
   1243 			if (strm->avail_out == 0) {
   1244 				/* avoid BUF_ERROR at next call, see above */
   1245 				s->last_flush = -1;
   1246 				return (Z_OK);
   1247 			}
   1248 		}
   1249 	}
   1250 	Assert(strm->avail_out > 0, "bug2");
   1251 
   1252 	if (flush != Z_FINISH)
   1253 		return (Z_OK);
   1254 	if (s->noheader)
   1255 		return (Z_STREAM_END);
   1256 
   1257 	/* Write the zlib trailer (adler32) */
   1258 	putShortMSB(s, (uInt)(strm->adler >> 16));
   1259 	putShortMSB(s, (uInt)(strm->adler & 0xffff));
   1260 	flush_pending(strm);
   1261 	/*
   1262 	 * If avail_out is zero, the application will call deflate
   1263 	 * again to flush the rest.
   1264 	 */
   1265 	s->noheader = -1;	/* write the trailer only once! */
   1266 	return (s->pending != 0 ? Z_OK : Z_STREAM_END);
   1267 }
   1268 
   1269 /* ========================================================================= */
   1270 int
   1271 deflateEnd(strm)
   1272     z_streamp strm;
   1273 {
   1274 	int status;
   1275 	deflate_state *s;
   1276 
   1277 	if (strm == Z_NULL || strm->state == Z_NULL)
   1278 		return (Z_STREAM_ERROR);
   1279 	s = (deflate_state *) strm->state;
   1280 
   1281 	status = s->status;
   1282 	if (status != INIT_STATE && status != BUSY_STATE &&
   1283 	    status != FINISH_STATE) {
   1284 		return (Z_STREAM_ERROR);
   1285 	}
   1286 
   1287 	/* Deallocate in reverse order of allocations: */
   1288 	TRY_FREE(strm, s->pending_buf);
   1289 	TRY_FREE(strm, s->head);
   1290 	TRY_FREE(strm, s->prev);
   1291 	TRY_FREE(strm, s->window);
   1292 
   1293 	ZFREE(strm, s);
   1294 	strm->state = Z_NULL;
   1295 
   1296 	return (status == BUSY_STATE ? Z_DATA_ERROR : Z_OK);
   1297 }
   1298 
   1299 /*
   1300  * =========================================================================
   1301  * Copy the source state to the destination state.
   1302  * To simplify the source, this is not supported for 16-bit MSDOS (which
   1303  * doesn't have enough memory anyway to duplicate compression states).
   1304  */
   1305 int
   1306 deflateCopy(dest, source)
   1307     z_streamp dest;
   1308     z_streamp source;
   1309 {
   1310 #ifdef MAXSEG_64K
   1311 	return (Z_STREAM_ERROR);
   1312 #else
   1313 	deflate_state *ds;
   1314 	deflate_state *ss;
   1315 	ushf *overlay;
   1316 
   1317 	if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
   1318 		return (Z_STREAM_ERROR);
   1319 	ss = (deflate_state *) source->state;
   1320 
   1321 	zmemcpy(dest, source, sizeof (*dest));
   1322 
   1323 	ds = (deflate_state *) ZALLOC(dest, 1, sizeof (deflate_state));
   1324 	if (ds == Z_NULL)
   1325 		return (Z_MEM_ERROR);
   1326 	dest->state = (struct internal_state FAR *) ds;
   1327 	zmemcpy(ds, ss, sizeof (*ds));
   1328 	ds->strm = dest;
   1329 
   1330 	ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof (Byte));
   1331 	ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof (Pos));
   1332 	ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof (Pos));
   1333 	overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof (ush)+2);
   1334 	ds->pending_buf = (uchf *) overlay;
   1335 
   1336 	if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
   1337 	    ds->pending_buf == Z_NULL) {
   1338 		ds->status = INIT_STATE;
   1339 		(void) deflateEnd(dest);
   1340 		return (Z_MEM_ERROR);
   1341 	}
   1342 	/* following zmemcpy doesn't work for 16-bit MSDOS */
   1343 	zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof (Byte));
   1344 	zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof (Pos));
   1345 	zmemcpy(ds->head, ss->head, ds->hash_size * sizeof (Pos));
   1346 	zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
   1347 
   1348 	ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
   1349 	ds->d_buf = overlay + ds->lit_bufsize/sizeof (ush);
   1350 	ds->l_buf = ds->pending_buf + (1+sizeof (ush))*ds->lit_bufsize;
   1351 
   1352 	ds->l_desc.dyn_tree = ds->dyn_ltree;
   1353 	ds->d_desc.dyn_tree = ds->dyn_dtree;
   1354 	ds->bl_desc.dyn_tree = ds->bl_tree;
   1355 
   1356 	return (Z_OK);
   1357 #endif
   1358 }
   1359 
   1360 /*
   1361  * ===========================================================================
   1362  * Return the number of bytes of output which are immediately available
   1363  * for output from the decompressor.		---PPP---
   1364  */
   1365 int
   1366 deflateOutputPending(strm)
   1367     z_streamp strm;
   1368 {
   1369 	if (strm == Z_NULL || strm->state == Z_NULL)
   1370 		return (0);
   1371 
   1372 	return (((deflate_state *)(strm->state))->pending);
   1373 }
   1374 
   1375 /*
   1376  * ===========================================================================
   1377  * Read a new buffer from the current input stream, update the adler32
   1378  * and total number of bytes read.  All deflate() input goes through
   1379  * this function so some applications may wish to modify it to avoid
   1380  * allocating a large strm->next_in buffer and copying from it.
   1381  * (See also flush_pending()).
   1382  */
   1383 local int
   1384 read_buf(strm, buf, size)
   1385     z_streamp strm;
   1386     Bytef *buf;
   1387     unsigned size;
   1388 {
   1389 	unsigned len = strm->avail_in;
   1390 
   1391 	if (len > size) len = size;
   1392 	if (len == 0)
   1393 		return (0);
   1394 
   1395 	strm->avail_in  -= len;
   1396 
   1397 	if (!((deflate_state *)(strm->state))->noheader) {
   1398 		strm->adler = adler32(strm->adler, strm->next_in, len);
   1399 	}
   1400 	zmemcpy(buf, strm->next_in, len);
   1401 	strm->next_in  += len;
   1402 	strm->total_in += len;
   1403 
   1404 	return ((int)len);
   1405 }
   1406 
   1407 /*
   1408  * ===========================================================================
   1409  * Initialize the "longest match" routines for a new zlib stream
   1410  */
   1411 local void
   1412 lm_init(s)
   1413     deflate_state *s;
   1414 {
   1415 	s->window_size = (ulg)2L*s->w_size;
   1416 
   1417 	CLEAR_HASH(s);
   1418 
   1419 	/* Set the default configuration parameters: */
   1420 	s->max_lazy_match   = configuration_table[s->level].max_lazy;
   1421 	s->good_match	= configuration_table[s->level].good_length;
   1422 	s->nice_match	= configuration_table[s->level].nice_length;
   1423 	s->max_chain_length = configuration_table[s->level].max_chain;
   1424 
   1425 	s->strstart = 0;
   1426 	s->block_start = 0L;
   1427 	s->lookahead = 0;
   1428 	s->match_length = s->prev_length = MIN_MATCH-1;
   1429 	s->match_available = 0;
   1430 	s->ins_h = 0;
   1431 #ifdef ASMV
   1432 	match_init();	/* initialize the asm code */
   1433 #endif
   1434 }
   1435 
   1436 /*
   1437  * ===========================================================================
   1438  * Set match_start to the longest match starting at the given string and
   1439  * return its length. Matches shorter or equal to prev_length are discarded,
   1440  * in which case the result is equal to prev_length and match_start is
   1441  * garbage.
   1442  * IN assertions: cur_match is the head of the hash chain for the current
   1443  *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
   1444  * OUT assertion: the match length is not greater than s->lookahead.
   1445  */
   1446 #ifndef ASMV
   1447 /*
   1448  * For 80x86 and 680x0, an optimized version will be provided in
   1449  * match.asm or match.S. The code will be functionally equivalent.
   1450  */
   1451 #ifndef FASTEST
   1452 local uInt
   1453 longest_match(s, cur_match)
   1454     deflate_state *s;
   1455     IPos cur_match;	/* current match */
   1456 {
   1457 	/* max hash chain length */
   1458 	unsigned chain_length = s->max_chain_length;
   1459 	register Bytef *scan = s->window + s->strstart;	/* current string */
   1460 	register Bytef *match;	/* matched string */
   1461 	register int len;	/* length of current match */
   1462 	int best_len = s->prev_length;	/* best match length so far */
   1463 	int nice_match = s->nice_match;	/* stop if match long enough */
   1464 	IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
   1465 	    s->strstart - (IPos)MAX_DIST(s) : NIL;
   1466 	/*
   1467 	 * Stop when cur_match becomes <= limit. To simplify the code,
   1468 	 * we prevent matches with the string of window index 0.
   1469 	 */
   1470 	Posf *prev = s->prev;
   1471 	uInt wmask = s->w_mask;
   1472 
   1473 #ifdef UNALIGNED_OK
   1474 	/*
   1475 	 * Compare two bytes at a time. Note: this is not always
   1476 	 * beneficial.  Try with and without -DUNALIGNED_OK to check.
   1477 	 */
   1478 	register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
   1479 	register ush scan_start = *(ushf*)scan;
   1480 	register ush scan_end   = *(ushf*)(scan+best_len-1);
   1481 #else
   1482 	register Bytef *strend = s->window + s->strstart + MAX_MATCH;
   1483 	register Byte scan_end1  = scan[best_len-1];
   1484 	register Byte scan_end   = scan[best_len];
   1485 #endif
   1486 
   1487 	/*
   1488 	 * The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2
   1489 	 * multiple of 16.  It is easy to get rid of this optimization
   1490 	 * if necessary.
   1491 	 */
   1492 	Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
   1493 
   1494 	/* Do not waste too much time if we already have a good match: */
   1495 	if (s->prev_length >= s->good_match) {
   1496 		chain_length >>= 2;
   1497 	}
   1498 	/*
   1499 	 * Do not look for matches beyond the end of the input. This
   1500 	 * is necessary to make deflate deterministic.
   1501 	 */
   1502 	if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
   1503 
   1504 	Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD,
   1505 	    "need lookahead");
   1506 
   1507 	do {
   1508 		Assert(cur_match <= s->strstart, "no future");
   1509 		match = s->window + cur_match;
   1510 
   1511 		/*
   1512 		 * Skip to next match if the match length cannot
   1513 		 * increase or if the match length is less than 2:
   1514 		 */
   1515 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
   1516 		/*
   1517 		 * This code assumes sizeof (unsigned short) == 2. Do
   1518 		 * not use UNALIGNED_OK if your compiler uses a
   1519 		 * different size.
   1520 		 */
   1521 		if (*(ushf*)(match+best_len-1) != scan_end ||
   1522 		    *(ushf*)match != scan_start) continue;
   1523 
   1524 		/*
   1525 		 * It is not necessary to compare scan[2] and match[2]
   1526 		 * since they are always equal when the other bytes
   1527 		 * match, given that the hash keys are equal and that
   1528 		 * HASH_BITS >= 8. Compare 2 bytes at a time at
   1529 		 * strstart+3, +5, ... up to strstart+257. We check
   1530 		 * for insufficient lookahead only every 4th
   1531 		 * comparison; the 128th check will be made at
   1532 		 * strstart+257. If MAX_MATCH-2 is not a multiple of
   1533 		 * 8, it is necessary to put more guard bytes at the
   1534 		 * end of the window, or to check more often for
   1535 		 * insufficient lookahead.
   1536 		 */
   1537 		Assert(scan[2] == match[2], "scan[2]?");
   1538 		scan++, match++;
   1539 		do {
   1540 		} while (*(ushf *)(scan += 2) == *(ushf *)(match += 2) &&
   1541 		    *(ushf *)(scan += 2) == *(ushf *)(match += 2) &&
   1542 		    *(ushf *)(scan += 2) == *(ushf *)(match += 2) &&
   1543 		    *(ushf *)(scan += 2) == *(ushf *)(match += 2) &&
   1544 		    scan < strend);
   1545 		/* The funny "do {}" generates better code on most compilers */
   1546 
   1547 		/* Here, scan <= window+strstart+257 */
   1548 		Assert(scan <= s->window+(unsigned)(s->window_size-1),
   1549 		    "wild scan");
   1550 		if (*scan == *match) scan++;
   1551 
   1552 		len = (MAX_MATCH - 1) - (int)(strend-scan);
   1553 		scan = strend - (MAX_MATCH-1);
   1554 
   1555 #else /* UNALIGNED_OK */
   1556 
   1557 		if (match[best_len]	!= scan_end	||
   1558 		    match[best_len-1]	!= scan_end1	||
   1559 		    *match		!= *scan	||
   1560 		    *++match		!= scan[1])
   1561 			continue;
   1562 
   1563 		/*
   1564 		 * The check at best_len-1 can be removed because it
   1565 		 * will be made again later. (This heuristic is not
   1566 		 * always a win.)  It is not necessary to compare
   1567 		 * scan[2] and match[2] since they are always equal
   1568 		 * when the other bytes match, given that the hash
   1569 		 * keys are equal and that HASH_BITS >= 8.
   1570 		 */
   1571 		scan += 2, match++;
   1572 		Assert(*scan == *match, "match[2]?");
   1573 
   1574 		/*
   1575 		 * We check for insufficient lookahead only every 8th
   1576 		 * comparison; the 256th check will be made at
   1577 		 * strstart+258.
   1578 		 */
   1579 		do {
   1580 		} while (*++scan == *++match && *++scan == *++match &&
   1581 		    *++scan == *++match && *++scan == *++match &&
   1582 		    *++scan == *++match && *++scan == *++match &&
   1583 		    *++scan == *++match && *++scan == *++match &&
   1584 		    scan < strend);
   1585 
   1586 		Assert(scan <= s->window+(unsigned)(s->window_size-1),
   1587 		    "wild scan");
   1588 
   1589 		len = MAX_MATCH - (int)(strend - scan);
   1590 		scan = strend - MAX_MATCH;
   1591 
   1592 #endif /* UNALIGNED_OK */
   1593 
   1594 		if (len > best_len) {
   1595 			s->match_start = cur_match;
   1596 			best_len = len;
   1597 			if (len >= nice_match) break;
   1598 #ifdef UNALIGNED_OK
   1599 			scan_end = *(ushf*)(scan+best_len-1);
   1600 #else
   1601 			scan_end1  = scan[best_len-1];
   1602 			scan_end   = scan[best_len];
   1603 #endif
   1604 		}
   1605 	} while ((cur_match = prev[cur_match & wmask]) > limit &&
   1606 	    --chain_length != 0);
   1607 
   1608 	if ((uInt)best_len <= s->lookahead)
   1609 		return (best_len);
   1610 	return (s->lookahead);
   1611 }
   1612 #else /* FASTEST */
   1613 /*
   1614  * ---------------------------------------------------------------------------
   1615  * Optimized version for level == 1 only
   1616  */
   1617 local uInt
   1618 longest_match(s, cur_match)
   1619 deflate_state *s;
   1620 IPos cur_match;		/* current match */
   1621 {
   1622 	register Bytef *scan = s->window + s->strstart; /* current string */
   1623 	register Bytef *match;		/* matched string */
   1624 	register int len;			/* length of current match */
   1625 	register Bytef *strend = s->window + s->strstart + MAX_MATCH;
   1626 
   1627 	/*
   1628 	 * The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2
   1629 	 * multiple of 16.  It is easy to get rid of this optimization
   1630 	 * if necessary.
   1631 	 */
   1632 	Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
   1633 
   1634 	Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD,
   1635 	    "need lookahead");
   1636 
   1637 	Assert(cur_match <= s->strstart, "no future");
   1638 
   1639 	match = s->window + cur_match;
   1640 
   1641 	/* Return failure if the match length is less than 2: */
   1642 	if (match[0] != scan[0] || match[1] != scan[1])
   1643 		return (MIN_MATCH-1);
   1644 
   1645 	/*
   1646 	 * The check at best_len-1 can be removed because it will be
   1647 	 * made again later. (This heuristic is not always a win.)  It
   1648 	 * is not necessary to compare scan[2] and match[2] since they
   1649 	 * are always equal when the other bytes match, given that the
   1650 	 * hash keys are equal and that HASH_BITS >= 8.
   1651 	 */
   1652 	scan += 2, match += 2;
   1653 	Assert(*scan == *match, "match[2]?");
   1654 
   1655 	/*
   1656 	 * We check for insufficient lookahead only every 8th comparison;
   1657 	 * the 256th check will be made at strstart+258.
   1658 	 */
   1659 	do {
   1660 	} while (*++scan == *++match && *++scan == *++match &&
   1661 	    *++scan == *++match && *++scan == *++match &&
   1662 	    *++scan == *++match && *++scan == *++match &&
   1663 	    *++scan == *++match && *++scan == *++match &&
   1664 	    scan < strend);
   1665 
   1666 	Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
   1667 
   1668 	len = MAX_MATCH - (int)(strend - scan);
   1669 
   1670 	if (len < MIN_MATCH)
   1671 		return (MIN_MATCH - 1);
   1672 
   1673 	s->match_start = cur_match;
   1674 	return (len <= s->lookahead ? len : s->lookahead);
   1675 }
   1676 #endif /* FASTEST */
   1677 #endif /* ASMV */
   1678 
   1679 #ifdef DEBUG_ZLIB
   1680 /*
   1681  * ===========================================================================
   1682  * Check that the match at match_start is indeed a match.
   1683  */
   1684 local void
   1685 check_match(s, start, match, length)
   1686     deflate_state *s;
   1687     IPos start, match;
   1688     int length;
   1689 {
   1690 	/* check that the match is indeed a match */
   1691 	if (zmemcmp(s->window + match, s->window + start, length) != EQUAL) {
   1692 		fprintf(stderr, " start %u, match %u, length %d\n",
   1693 		    start, match, length);
   1694 		do {
   1695 			fprintf(stderr, "%c%c", s->window[match++],
   1696 			    s->window[start++]);
   1697 		} while (--length != 0);
   1698 		z_error("invalid match");
   1699 	}
   1700 	if (z_verbose > 1) {
   1701 		fprintf(stderr, "\\[%d,%d]", start-match, length);
   1702 		do { putc(s->window[start++], stderr); } while (--length != 0);
   1703 	}
   1704 }
   1705 #else
   1706 #define	check_match(s, start, match, length)
   1707 #endif
   1708 
   1709 /*
   1710  * ===========================================================================
   1711  * Fill the window when the lookahead becomes insufficient.
   1712  * Updates strstart and lookahead.
   1713  *
   1714  * IN assertion: lookahead < MIN_LOOKAHEAD
   1715  * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
   1716  *    At least one byte has been read, or avail_in == 0; reads are
   1717  *    performed for at least two bytes (required for the zip translate_eol
   1718  *    option -- not supported here).
   1719  */
   1720 local void
   1721 fill_window(s)
   1722     deflate_state *s;
   1723 {
   1724 	register unsigned n, m;
   1725 	register Posf *p;
   1726 	unsigned more;	/* Amount of free space at the end of the window. */
   1727 	uInt wsize = s->w_size;
   1728 
   1729 	do {
   1730 		more = (unsigned)(s->window_size -(ulg)s->lookahead -
   1731 		    (ulg)s->strstart);
   1732 
   1733 		/* Deal with !@#$% 64K limit: */
   1734 		if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
   1735 			more = wsize;
   1736 
   1737 		} else if (more == (unsigned)(-1)) {
   1738 			/*
   1739 			 * Very unlikely, but possible on 16 bit
   1740 			 * machine if strstart == 0 and lookahead == 1
   1741 			 * (input done one byte at time)
   1742 			 */
   1743 			more--;
   1744 
   1745 			/*
   1746 			 * If the window is almost full and there is
   1747 			 * insufficient lookahead, move the upper half
   1748 			 * to the lower one to make room in the upper
   1749 			 * half.
   1750 			 */
   1751 		} else if (s->strstart >= wsize+MAX_DIST(s)) {
   1752 
   1753 			Assert(wsize+wsize <= s->window_size, "wsize*2");
   1754 			zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
   1755 			s->match_start -= wsize;
   1756 			/* we now have strstart >= MAX_DIST */
   1757 			s->strstart    -= wsize;
   1758 			s->block_start -= (long)wsize;
   1759 
   1760 			/*
   1761 			 * Slide the hash table (could be avoided with
   1762 			 * 32 bit values at the expense of memory
   1763 			 * usage). We slide even when level == 0 to
   1764 			 * keep the hash table consistent if we switch
   1765 			 * back to level > 0 later. (Using level 0
   1766 			 * permanently is not an optimal usage of
   1767 			 * zlib, so we don't care about this
   1768 			 * pathological case.)
   1769 			 */
   1770 			n = s->hash_size;
   1771 			p = &s->head[n];
   1772 			do {
   1773 				m = *--p;
   1774 				*p = (Pos)(m >= wsize ? m-wsize : NIL);
   1775 			} while (--n);
   1776 
   1777 			n = wsize;
   1778 #ifndef FASTEST
   1779 			p = &s->prev[n];
   1780 			do {
   1781 				m = *--p;
   1782 				*p = (Pos)(m >= wsize ? m-wsize : NIL);
   1783 				/*
   1784 				 * If n is not on any hash chain,
   1785 				 * prev[n] is garbage but its value
   1786 				 * will never be used.
   1787 				 */
   1788 			} while (--n);
   1789 #endif
   1790 			more += wsize;
   1791 		}
   1792 		if (s->strm->avail_in == 0)
   1793 			return;
   1794 
   1795 		/*
   1796 		 * If there was no sliding:
   1797 		 *    strstart <= WSIZE+MAX_DIST-1 &&
   1798 		 *	lookahead <= MIN_LOOKAHEAD - 1 &&
   1799 		 *    more == window_size - lookahead - strstart
   1800 		 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE +
   1801 		 *	MAX_DIST-1)
   1802 		 * => more >= window_size - 2*WSIZE + 2
   1803 		 * In the BIG_MEM or MMAP case (not yet supported),
   1804 		 *   window_size == input_size + MIN_LOOKAHEAD  &&
   1805 		 *   strstart + s->lookahead <= input_size =>
   1806 		 *	more >= MIN_LOOKAHEAD.
   1807 		 * Otherwise, window_size == 2*WSIZE so more >= 2.
   1808 		 * If there was sliding, more >= WSIZE. So in all cases,
   1809 		 * more >= 2.
   1810 		 */
   1811 		Assert(more >= 2, "more < 2");
   1812 		Assert(s->strstart + s->lookahead + more <= s->window_size,
   1813 		    "read too much");
   1814 
   1815 		n = read_buf(s->strm, s->window + s->strstart + s->lookahead,
   1816 		    more);
   1817 		s->lookahead += n;
   1818 
   1819 		/* Initialize the hash value now that we have some input: */
   1820 		if (s->lookahead >= MIN_MATCH) {
   1821 			s->ins_h = s->window[s->strstart];
   1822 			UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
   1823 #if MIN_MATCH != 3
   1824 			Call UPDATE_HASH() MIN_MATCH-3 more times
   1825 #endif
   1826 			    }
   1827 		/*
   1828 		 * If the whole input has less than MIN_MATCH bytes,
   1829 		 * ins_h is garbage, but this is not important since
   1830 		 * only literal bytes will be emitted.
   1831 		 */
   1832 
   1833 	} while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
   1834 }
   1835 
   1836 /*
   1837  * ===========================================================================
   1838  * Flush the current block, with given end-of-file flag.
   1839  * IN assertion: strstart is set to the end of the current match.
   1840  */
   1841 #define	FLUSH_BLOCK_ONLY(s, eof) { \
   1842 	_tr_flush_block(s, (s->block_start >= 0L ? \
   1843 		(charf *)&s->window[(unsigned)s->block_start] : \
   1844 		(charf *)Z_NULL), \
   1845 		(ulg)((long)s->strstart - s->block_start), \
   1846 		(eof)); \
   1847 	s->block_start = s->strstart; \
   1848 	flush_pending(s->strm); \
   1849 	Tracev((stderr, "[FLUSH]")); \
   1850 }
   1851 
   1852 /* Same but force premature exit if necessary. */
   1853 #define	FLUSH_BLOCK(s, eof) { \
   1854 	FLUSH_BLOCK_ONLY(s, eof); \
   1855 	if (s->strm->avail_out == 0) \
   1856 		return ((eof) ? finish_started : need_more); \
   1857 }
   1858 
   1859 /*
   1860  * ===========================================================================
   1861  * Copy without compression as much as possible from the input stream, return
   1862  * the current block state.
   1863  * This function does not insert new strings in the dictionary since
   1864  * uncompressible data is probably not useful. This function is used
   1865  * only for the level=0 compression option.
   1866  * NOTE: this function should be optimized to avoid extra copying from
   1867  * window to pending_buf.
   1868  */
   1869 local block_state
   1870 deflate_stored(s, flush)
   1871     deflate_state *s;
   1872     int flush;
   1873 {
   1874 	/*
   1875 	 * Stored blocks are limited to 0xffff bytes, pending_buf is
   1876 	 * limited to pending_buf_size, and each stored block has a 5
   1877 	 * byte header:
   1878 	 */
   1879 	ulg max_block_size = 0xffff;
   1880 	ulg max_start;
   1881 
   1882 	if (max_block_size > s->pending_buf_size - 5) {
   1883 		max_block_size = s->pending_buf_size - 5;
   1884 	}
   1885 
   1886 	/* Copy as much as possible from input to output: */
   1887 	for (;;) {
   1888 		/* Fill the window as much as possible: */
   1889 		if (s->lookahead <= 1) {
   1890 
   1891 			Assert(s->strstart < s->w_size+MAX_DIST(s) ||
   1892 			    s->block_start >= (long)s->w_size,
   1893 			    "slide too late");
   1894 
   1895 			fill_window(s);
   1896 			if (s->lookahead == 0 && flush == Z_NO_FLUSH)
   1897 				return (need_more);
   1898 
   1899 			if (s->lookahead == 0)
   1900 				break;	/* flush the current block */
   1901 		}
   1902 		Assert(s->block_start >= 0L, "block gone");
   1903 
   1904 		s->strstart += s->lookahead;
   1905 		s->lookahead = 0;
   1906 
   1907 		/* Emit a stored block if pending_buf will be full: */
   1908 		max_start = s->block_start + max_block_size;
   1909 		if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
   1910 			/*
   1911 			 * strstart == 0 is possible when wraparound
   1912 			 * on 16-bit machine
   1913 			 */
   1914 			s->lookahead = (uInt)(s->strstart - max_start);
   1915 			s->strstart = (uInt)max_start;
   1916 			FLUSH_BLOCK(s, 0);
   1917 		}
   1918 		/*
   1919 		 * Flush if we may have to slide, otherwise
   1920 		 * block_start may become negative and the data will
   1921 		 * be gone:
   1922 		 */
   1923 		if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
   1924 			FLUSH_BLOCK(s, 0);
   1925 		}
   1926 	}
   1927 	FLUSH_BLOCK(s, flush == Z_FINISH);
   1928 	return (flush == Z_FINISH ? finish_done : block_done);
   1929 }
   1930 
   1931 /*
   1932  * ===========================================================================
   1933  * Compress as much as possible from the input stream, return the current
   1934  * block state.
   1935  * This function does not perform lazy evaluation of matches and inserts
   1936  * new strings in the dictionary only for unmatched strings or for short
   1937  * matches. It is used only for the fast compression options.
   1938  */
   1939 local block_state
   1940 deflate_fast(s, flush)
   1941     deflate_state *s;
   1942     int flush;
   1943 {
   1944 	IPos hash_head = NIL;	/* head of the hash chain */
   1945 	int bflush;	/* set if current block must be flushed */
   1946 
   1947 	for (;;) {
   1948 		/*
   1949 		 * Make sure that we always have enough lookahead,
   1950 		 * except at the end of the input file. We need
   1951 		 * MAX_MATCH bytes for the next match, plus MIN_MATCH
   1952 		 * bytes to insert the string following the next
   1953 		 * match.
   1954 		 */
   1955 		if (s->lookahead < MIN_LOOKAHEAD) {
   1956 			fill_window(s);
   1957 			if (s->lookahead < MIN_LOOKAHEAD &&
   1958 			    flush == Z_NO_FLUSH) {
   1959 				return (need_more);
   1960 			}
   1961 			if (s->lookahead == 0)
   1962 				break;	/* flush the current block */
   1963 		}
   1964 
   1965 		/*
   1966 		 * Insert the string window[strstart .. strstart+2] in
   1967 		 * the dictionary, and set hash_head to the head of
   1968 		 * the hash chain:
   1969 		 */
   1970 		if (s->lookahead >= MIN_MATCH) {
   1971 			INSERT_STRING(s, s->strstart, hash_head);
   1972 		}
   1973 
   1974 		/*
   1975 		 * Find the longest match, discarding those <=
   1976 		 * prev_length.  At this point we have always
   1977 		 * match_length < MIN_MATCH
   1978 		 */
   1979 		if (hash_head != NIL && s->strstart - hash_head <=
   1980 		    MAX_DIST(s)) {
   1981 			/*
   1982 			 * To simplify the code, we prevent matches
   1983 			 * with the string of window index 0 (in
   1984 			 * particular we have to avoid a match of the
   1985 			 * string with itself at the start of the
   1986 			 * input file).
   1987 			 */
   1988 			if (s->strategy != Z_HUFFMAN_ONLY) {
   1989 				s->match_length = longest_match(s, hash_head);
   1990 			}
   1991 			/* longest_match() sets match_start */
   1992 		}
   1993 		if (s->match_length >= MIN_MATCH) {
   1994 			check_match(s, s->strstart, s->match_start,
   1995 			    s->match_length);
   1996 
   1997 			_tr_tally_dist(s, s->strstart - s->match_start,
   1998 			    s->match_length - MIN_MATCH, bflush);
   1999 
   2000 			s->lookahead -= s->match_length;
   2001 
   2002 			/*
   2003 			 * Insert new strings in the hash table only
   2004 			 * if the match length is not too large. This
   2005 			 * saves time but degrades compression.
   2006 			 */
   2007 #ifndef FASTEST
   2008 			if (s->match_length <= s->max_insert_length &&
   2009 			    s->lookahead >= MIN_MATCH) {
   2010 				/* string at strstart already in hash table */
   2011 				s->match_length--;
   2012 				do {
   2013 					s->strstart++;
   2014 					INSERT_STRING(s, s->strstart,
   2015 					    hash_head);
   2016 					/*
   2017 					 * strstart never exceeds
   2018 					 * WSIZE-MAX_MATCH, so there
   2019 					 * are always MIN_MATCH bytes
   2020 					 * ahead.
   2021 					 */
   2022 				} while (--s->match_length != 0);
   2023 				s->strstart++;
   2024 			} else
   2025 #endif
   2026 			{
   2027 				s->strstart += s->match_length;
   2028 				s->match_length = 0;
   2029 				s->ins_h = s->window[s->strstart];
   2030 				UPDATE_HASH(s, s->ins_h,
   2031 				    s->window[s->strstart+1]);
   2032 #if MIN_MATCH != 3
   2033 				Call UPDATE_HASH() MIN_MATCH-3 more times
   2034 #endif
   2035 				/*
   2036 				 * If lookahead < MIN_MATCH, ins_h is
   2037 				 * garbage, but it does not matter
   2038 				 * since it will be recomputed at next
   2039 				 * deflate call.
   2040 				 */
   2041 			}
   2042 		} else {
   2043 			/* No match, output a literal byte */
   2044 			Tracevv((stderr, "%c", s->window[s->strstart]));
   2045 			_tr_tally_lit(s, s->window[s->strstart], bflush);
   2046 			s->lookahead--;
   2047 			s->strstart++;
   2048 		}
   2049 		if (bflush) FLUSH_BLOCK(s, 0);
   2050 	}
   2051 	FLUSH_BLOCK(s, flush == Z_FINISH);
   2052 	return (flush == Z_FINISH ? finish_done : block_done);
   2053 }
   2054 
   2055 /*
   2056  * ===========================================================================
   2057  * Same as above, but achieves better compression. We use a lazy
   2058  * evaluation for matches: a match is finally adopted only if there is
   2059  * no better match at the next window position.
   2060  */
   2061 local block_state
   2062 deflate_slow(s, flush)
   2063     deflate_state *s;
   2064     int flush;
   2065 {
   2066 	IPos hash_head = NIL;	/* head of hash chain */
   2067 	int bflush;	/* set if current block must be flushed */
   2068 
   2069 	/* Process the input block. */
   2070 	for (;;) {
   2071 		/*
   2072 		 * Make sure that we always have enough lookahead,
   2073 		 * except at the end of the input file. We need
   2074 		 * MAX_MATCH bytes for the next match, plus MIN_MATCH
   2075 		 * bytes to insert the string following the next
   2076 		 * match.
   2077 		 */
   2078 		if (s->lookahead < MIN_LOOKAHEAD) {
   2079 			fill_window(s);
   2080 			if (s->lookahead < MIN_LOOKAHEAD &&
   2081 			    flush == Z_NO_FLUSH) {
   2082 				return (need_more);
   2083 			}
   2084 			/* flush the current block */
   2085 			if (s->lookahead == 0)
   2086 				break;
   2087 		}
   2088 
   2089 		/*
   2090 		 * Insert the string window[strstart .. strstart+2] in
   2091 		 * the dictionary, and set hash_head to the head of
   2092 		 * the hash chain:
   2093 		 */
   2094 		if (s->lookahead >= MIN_MATCH) {
   2095 			INSERT_STRING(s, s->strstart, hash_head);
   2096 		}
   2097 
   2098 		/*
   2099 		 * Find the longest match, discarding those <=
   2100 		 * prev_length.
   2101 		 */
   2102 		s->prev_length = s->match_length;
   2103 		s->prev_match = s->match_start;
   2104 		s->match_length = MIN_MATCH-1;
   2105 
   2106 		if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
   2107 		    s->strstart - hash_head <= MAX_DIST(s)) {
   2108 			/*
   2109 			 * To simplify the code, we prevent matches
   2110 			 * with the string of window index 0 (in
   2111 			 * particular we have to avoid a match of the
   2112 			 * string with itself at the start of the
   2113 			 * input file).
   2114 			 */
   2115 			if (s->strategy != Z_HUFFMAN_ONLY) {
   2116 				s->match_length = longest_match(s, hash_head);
   2117 			}
   2118 			/* longest_match() sets match_start */
   2119 
   2120 			if (s->match_length <= 5 &&
   2121 			    (s->strategy == Z_FILTERED ||
   2122 				(s->match_length == MIN_MATCH &&
   2123 				    s->strstart - s->match_start > TOO_FAR))) {
   2124 
   2125 				/*
   2126 				 * If prev_match is also MIN_MATCH,
   2127 				 * match_start is garbage but we will
   2128 				 * ignore the current match anyway.
   2129 				 */
   2130 				s->match_length = MIN_MATCH-1;
   2131 			}
   2132 		}
   2133 		/*
   2134 		 * If there was a match at the previous step and the
   2135 		 * current match is not better, output the previous
   2136 		 * match:
   2137 		 */
   2138 		if (s->prev_length >= MIN_MATCH &&
   2139 		    s->match_length <= s->prev_length) {
   2140 			uInt max_insert = s->strstart + s->lookahead -
   2141 			    MIN_MATCH;
   2142 			/* Do not insert strings in hash table beyond this. */
   2143 
   2144 			check_match(s, s->strstart-1, s->prev_match,
   2145 			    s->prev_length);
   2146 
   2147 			_tr_tally_dist(s, s->strstart -1 - s->prev_match,
   2148 			    s->prev_length - MIN_MATCH, bflush);
   2149 
   2150 			/*
   2151 			 * Insert in hash table all strings up to the
   2152 			 * end of the match.  strstart-1 and strstart
   2153 			 * are already inserted. If there is not
   2154 			 * enough lookahead, the last two strings are
   2155 			 * not inserted in the hash table.
   2156 			 */
   2157 			s->lookahead -= s->prev_length-1;
   2158 			s->prev_length -= 2;
   2159 			do {
   2160 				if (++s->strstart <= max_insert) {
   2161 					INSERT_STRING(s, s->strstart,
   2162 					    hash_head);
   2163 				}
   2164 			} while (--s->prev_length != 0);
   2165 			s->match_available = 0;
   2166 			s->match_length = MIN_MATCH-1;
   2167 			s->strstart++;
   2168 
   2169 			if (bflush) FLUSH_BLOCK(s, 0);
   2170 
   2171 		} else if (s->match_available) {
   2172 			/*
   2173 			 * If there was no match at the previous
   2174 			 * position, output a single literal. If there
   2175 			 * was a match but the current match is
   2176 			 * longer, truncate the previous match to a
   2177 			 * single literal.
   2178 			 */
   2179 			Tracevv((stderr, "%c", s->window[s->strstart-1]));
   2180 			_tr_tally_lit(s, s->window[s->strstart-1], bflush);
   2181 			if (bflush) {
   2182 				FLUSH_BLOCK_ONLY(s, 0);
   2183 			}
   2184 			s->strstart++;
   2185 			s->lookahead--;
   2186 			if (s->strm->avail_out == 0)
   2187 				return (need_more);
   2188 		} else {
   2189 			/*
   2190 			 * There is no previous match to compare with,
   2191 			 * wait for the next step to decide.
   2192 			 */
   2193 			s->match_available = 1;
   2194 			s->strstart++;
   2195 			s->lookahead--;
   2196 		}
   2197 	}
   2198 	Assert(flush != Z_NO_FLUSH, "no flush?");
   2199 	if (s->match_available) {
   2200 		Tracevv((stderr, "%c", s->window[s->strstart-1]));
   2201 		_tr_tally_lit(s, s->window[s->strstart-1], bflush);
   2202 		s->match_available = 0;
   2203 	}
   2204 	FLUSH_BLOCK(s, flush == Z_FINISH);
   2205 	return (flush == Z_FINISH ? finish_done : block_done);
   2206 }
   2207 /* --- deflate.c */
   2208 
   2209 /* +++ trees.c */
   2210 /*
   2211  * trees.c -- output deflated data using Huffman coding
   2212  * Copyright (C) 1995-1998 Jean-loup Gailly
   2213  * For conditions of distribution and use, see copyright notice in zlib.h
   2214  */
   2215 
   2216 /*
   2217  *  ALGORITHM
   2218  *
   2219  *      The "deflation" process uses several Huffman trees. The more
   2220  *      common source values are represented by shorter bit sequences.
   2221  *
   2222  *      Each code tree is stored in a compressed form which is itself
   2223  * a Huffman encoding of the lengths of all the code strings (in
   2224  * ascending order by source values).  The actual code strings are
   2225  * reconstructed from the lengths in the inflate process, as described
   2226  * in the deflate specification.
   2227  *
   2228  *  REFERENCES
   2229  *
   2230  *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
   2231  *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
   2232  *
   2233  *      Storer, James A.
   2234  *          Data Compression:  Methods and Theory, pp. 49-50.
   2235  *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
   2236  *
   2237  *      Sedgewick, R.
   2238  *          Algorithms, p290.
   2239  *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
   2240  */
   2241 
   2242 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
   2243 
   2244 /* #include "deflate.h" */
   2245 
   2246 #ifdef DEBUG_ZLIB
   2247 #include <ctype.h>
   2248 #endif
   2249 
   2250 /*
   2251  * ===========================================================================
   2252  * Constants
   2253  */
   2254 
   2255 #define	MAX_BL_BITS 7
   2256 /* Bit length codes must not exceed MAX_BL_BITS bits */
   2257 
   2258 #define	END_BLOCK 256
   2259 /* end of block literal code */
   2260 
   2261 #define	REP_3_6		16
   2262 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
   2263 
   2264 #define	REPZ_3_10	17
   2265 /* repeat a zero length 3-10 times  (3 bits of repeat count) */
   2266 
   2267 #define	REPZ_11_138	18
   2268 /* repeat a zero length 11-138 times  (7 bits of repeat count) */
   2269 
   2270 /* extra bits for each length code */
   2271 local const int extra_lbits[LENGTH_CODES] = {
   2272 	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4,
   2273 	4, 4, 4, 5, 5, 5, 5, 0};
   2274 
   2275 /* extra bits for each distance code */
   2276 local const int extra_dbits[D_CODES] = {
   2277 	0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9,
   2278 	9, 10, 10, 11, 11, 12, 12, 13, 13};
   2279 
   2280 /* extra bits for each bit length code */
   2281 local const int extra_blbits[BL_CODES] = {
   2282 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7};
   2283 
   2284 local const uch bl_order[BL_CODES] = {
   2285 	16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
   2286 
   2287 /*
   2288  * The lengths of the bit length codes are sent in order of decreasing
   2289  * probability, to avoid transmitting the lengths for unused bit
   2290  * length codes.
   2291  */
   2292 
   2293 #define	Buf_size (8 * 2*sizeof (char))
   2294 /*
   2295  * Number of bits used within bi_buf. (bi_buf might be implemented on
   2296  * more than 16 bits on some systems.)
   2297  */
   2298 
   2299 /*
   2300  * ===========================================================================
   2301  * Local data. These are initialized only once.
   2302  */
   2303 #define	DIST_CODE_LEN  512 /* see definition of array dist_code below */
   2304 
   2305 local ct_data static_ltree[L_CODES+2];
   2306 /*
   2307  * The static literal tree. Since the bit lengths are imposed, there
   2308  * is no need for the L_CODES extra codes used during heap
   2309  * construction. However The codes 286 and 287 are needed to build a
   2310  * canonical tree (see _tr_init below).
   2311  */
   2312 
   2313 local ct_data static_dtree[D_CODES];
   2314 /*
   2315  * The static distance tree. (Actually a trivial tree since all codes
   2316  * use 5 bits.)
   2317  */
   2318 
   2319 local uch _dist_code[512];
   2320 /*
   2321  * distance codes. The first 256 values correspond to the distances 3
   2322  * .. 258, the last 256 values correspond to the top 8 bits of the 15
   2323  * bit distances.
   2324  */
   2325 
   2326 local uch _length_code[MAX_MATCH-MIN_MATCH+1];
   2327 /* length code for each normalized match length (0 == MIN_MATCH) */
   2328 
   2329 local int base_length[LENGTH_CODES];
   2330 /* First normalized length for each code (0 = MIN_MATCH) */
   2331 
   2332 local int base_dist[D_CODES];
   2333 /* First normalized distance for each code (0 = distance of 1) */
   2334 
   2335 struct static_tree_desc_s {
   2336 	const ct_data *static_tree;	/* static tree or NULL */
   2337 	const intf    *extra_bits;	/* extra bits for each code or NULL */
   2338 	int	extra_base;	/* base index for extra_bits */
   2339 	int	elems;	/* max number of elements in the tree */
   2340 	int	max_length;	/* max bit length for the codes */
   2341 };
   2342 
   2343 local static_tree_desc  static_l_desc = {
   2344 	static_ltree, extra_lbits, LITERALS+1,	L_CODES, MAX_BITS};
   2345 
   2346 local static_tree_desc  static_d_desc = {
   2347 	static_dtree, extra_dbits, 0,		D_CODES, MAX_BITS};
   2348 
   2349 local static_tree_desc  static_bl_desc = {
   2350 	(const ct_data *)0, extra_blbits, 0,		BL_CODES, MAX_BL_BITS};
   2351 
   2352 /*
   2353  * ===========================================================================
   2354  * Local (static) routines in this file.
   2355  */
   2356 
   2357 local void tr_static_init OF((void));
   2358 local void init_block	OF((deflate_state *s));
   2359 local void pqdownheap	OF((deflate_state *s, ct_data *tree, int k));
   2360 local void gen_bitlen	OF((deflate_state *s, tree_desc *desc));
   2361 local void gen_codes	OF((ct_data *tree, int max_code, ushf *bl_count));
   2362 local void build_tree	OF((deflate_state *s, tree_desc *desc));
   2363 local void scan_tree	OF((deflate_state *s, ct_data *tree, int max_code));
   2364 local void send_tree	OF((deflate_state *s, ct_data *tree, int max_code));
   2365 local int  build_bl_tree	OF((deflate_state *s));
   2366 local void send_all_trees	OF((deflate_state *s, int lcodes, int dcodes,
   2367     int blcodes));
   2368 local void compress_block OF((deflate_state *s, ct_data *ltree,
   2369     ct_data *dtree));
   2370 local void set_data_type	OF((deflate_state *s));
   2371 local unsigned bi_reverse	OF((unsigned value, int length));
   2372 local void bi_windup	OF((deflate_state *s));
   2373 local void bi_flush	OF((deflate_state *s));
   2374 local void copy_block	OF((deflate_state *s, charf *buf, unsigned len,
   2375     int header));
   2376 
   2377 #ifndef DEBUG_ZLIB
   2378 #define	send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
   2379 /* Send a code of the given tree. c and tree must not have side effects */
   2380 
   2381 #else /* DEBUG_ZLIB */
   2382 #define	send_code(s, c, tree) \
   2383 	{ if (z_verbose > 2) fprintf(stderr, "\ncd %3d ", (c)); \
   2384 	send_bits(s, tree[c].Code, tree[c].Len); }
   2385 #endif
   2386 
   2387 /*
   2388  * ===========================================================================
   2389  * Output a short LSB first on the stream.
   2390  * IN assertion: there is enough room in pendingBuf.
   2391  */
   2392 #define	put_short(s, w) { \
   2393 	put_byte(s, (uch)((w) & 0xff)); \
   2394 	put_byte(s, (uch)((ush)(w) >> 8)); \
   2395 }
   2396 
   2397 /*
   2398  * ===========================================================================
   2399  * Send a value on a given number of bits.
   2400  * IN assertion: length <= 16 and value fits in length bits.
   2401  */
   2402 #ifdef DEBUG_ZLIB
   2403 local void send_bits	OF((deflate_state *s, int value, int length));
   2404 
   2405 local void
   2406 send_bits(s, value, length)
   2407     deflate_state *s;
   2408     int value;	/* value to send */
   2409     int length;	/* number of bits */
   2410 {
   2411 	Tracevv((stderr, " l %2d v %4x ", length, value));
   2412 	Assert(length > 0 && length <= 15, "invalid length");
   2413 	s->bits_sent += (ulg)length;
   2414 
   2415 	/*
   2416 	 * If not enough room in bi_buf, use (valid) bits from bi_buf
   2417 	 * and (16 - bi_valid) bits from value, leaving (width -
   2418 	 * (16-bi_valid)) unused bits in value.
   2419 	 */
   2420 	if (s->bi_valid > (int)Buf_size - length) {
   2421 		s->bi_buf |= (value << s->bi_valid);
   2422 		put_short(s, s->bi_buf);
   2423 		s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
   2424 		s->bi_valid += length - Buf_size;
   2425 	} else {
   2426 		s->bi_buf |= value << s->bi_valid;
   2427 		s->bi_valid += length;
   2428 	}
   2429 }
   2430 #else /* !DEBUG_ZLIB */
   2431 
   2432 #define	send_bits(s, value, length) \
   2433 {	int len = length; \
   2434 	if (s->bi_valid > (int)Buf_size - len) {\
   2435 		int val = value; \
   2436 		s->bi_buf |= (val << s->bi_valid); \
   2437 		put_short(s, s->bi_buf); \
   2438 		s->bi_buf = (ush)val >> (Buf_size - s->bi_valid); \
   2439 		s->bi_valid += len - Buf_size; \
   2440 	} else {\
   2441 		s->bi_buf |= (value) << s->bi_valid; \
   2442 		s->bi_valid += len; \
   2443 	}\
   2444 }
   2445 #endif /* DEBUG_ZLIB */
   2446 
   2447 
   2448 #define	MAX(a, b) (a >= b ? a : b)
   2449 /* the arguments must not have side effects */
   2450 
   2451 /*
   2452  * ===========================================================================
   2453  * Initialize the various 'constant' tables. In a multi-threaded environment,
   2454  * this function may be called by two threads concurrently, but this is
   2455  * harmless since both invocations do exactly the same thing.
   2456  */
   2457 local void
   2458 tr_static_init()
   2459 {
   2460 	static int static_init_done = 0;
   2461 	int n;	/* iterates over tree elements */
   2462 	int bits;	/* bit counter */
   2463 	int length;	/* length value */
   2464 	int code;	/* code value */
   2465 	int dist;	/* distance index */
   2466 	ush bl_count[MAX_BITS+1];
   2467 	/* number of codes at each bit length for an optimal tree */
   2468 
   2469 	if (static_init_done)
   2470 		return;
   2471 
   2472 	/* For some embedded targets, global variables are not initialized: */
   2473 	static_l_desc.static_tree = static_ltree;
   2474 	static_l_desc.extra_bits = extra_lbits;
   2475 	static_d_desc.static_tree = static_dtree;
   2476 	static_d_desc.extra_bits = extra_dbits;
   2477 	static_bl_desc.extra_bits = extra_blbits;
   2478 
   2479 	/* Initialize the mapping length (0..255) -> length code (0..28) */
   2480 	length = 0;
   2481 	for (code = 0; code < LENGTH_CODES-1; code++) {
   2482 		base_length[code] = length;
   2483 		for (n = 0; n < (1<<extra_lbits[code]); n++) {
   2484 			_length_code[length++] = (uch)code;
   2485 		}
   2486 	}
   2487 	Assert(length == 256, "tr_static_init: length != 256");
   2488 	/*
   2489 	 * Note that the length 255 (match length 258) can be
   2490 	 * represented in two different ways: code 284 + 5 bits or
   2491 	 * code 285, so we overwrite _length_code[255] to use the best
   2492 	 * encoding:
   2493 	 */
   2494 	_length_code[length-1] = (uch)code;
   2495 
   2496 	/* Initialize the mapping dist (0..32K) -> dist code (0..29) */
   2497 	dist = 0;
   2498 	for (code = 0; code < 16; code++) {
   2499 		base_dist[code] = dist;
   2500 		for (n = 0; n < (1<<extra_dbits[code]); n++) {
   2501 			_dist_code[dist++] = (uch)code;
   2502 		}
   2503 	}
   2504 	Assert(dist == 256, "tr_static_init: dist != 256");
   2505 	dist >>= 7;	/* from now on, all distances are divided by 128 */
   2506 	for (; code < D_CODES; code++) {
   2507 		base_dist[code] = dist << 7;
   2508 		for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
   2509 			_dist_code[256 + dist++] = (uch)code;
   2510 		}
   2511 	}
   2512 	Assert(dist == 256, "tr_static_init: 256+dist != 512");
   2513 
   2514 	/* Construct the codes of the static literal tree */
   2515 	for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
   2516 	n = 0;
   2517 	while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
   2518 	while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
   2519 	while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
   2520 	while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
   2521 	/*
   2522 	 * Codes 286 and 287 do not exist, but we must include them in the
   2523 	 * tree construction to get a canonical Huffman tree (longest code
   2524 	 * all ones)
   2525 	 */
   2526 	gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
   2527 
   2528 	/* The static distance tree is trivial: */
   2529 	for (n = 0; n < D_CODES; n++) {
   2530 		static_dtree[n].Len = 5;
   2531 		static_dtree[n].Code = bi_reverse((unsigned)n, 5);
   2532 	}
   2533 	static_init_done = 1;
   2534 }
   2535 
   2536 /*
   2537  * ===========================================================================
   2538  * Initialize the tree data structures for a new zlib stream.
   2539  */
   2540 void
   2541 _tr_init(s)
   2542     deflate_state *s;
   2543 {
   2544 	tr_static_init();
   2545 
   2546 	s->l_desc.dyn_tree = s->dyn_ltree;
   2547 	s->l_desc.stat_desc = &static_l_desc;
   2548 
   2549 	s->d_desc.dyn_tree = s->dyn_dtree;
   2550 	s->d_desc.stat_desc = &static_d_desc;
   2551 
   2552 	s->bl_desc.dyn_tree = s->bl_tree;
   2553 	s->bl_desc.stat_desc = &static_bl_desc;
   2554 
   2555 	s->bi_buf = 0;
   2556 	s->bi_valid = 0;
   2557 	s->last_eob_len = 8;	/* enough lookahead for inflate */
   2558 	s->compressed_len = 0L;		/* PPP */
   2559 #ifdef DEBUG_ZLIB
   2560 	s->bits_sent = 0L;
   2561 #endif
   2562 
   2563 	/* Initialize the first block of the first file: */
   2564 	init_block(s);
   2565 }
   2566 
   2567 /*
   2568  * ===========================================================================
   2569  * Initialize a new block.
   2570  */
   2571 local void
   2572 init_block(s)
   2573     deflate_state *s;
   2574 {
   2575 	int n;	/* iterates over tree elements */
   2576 
   2577 	/* Initialize the trees. */
   2578 	for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
   2579 	for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
   2580 	for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
   2581 
   2582 	s->dyn_ltree[END_BLOCK].Freq = 1;
   2583 	s->opt_len = s->static_len = 0L;
   2584 	s->last_lit = s->matches = 0;
   2585 }
   2586 
   2587 #define	SMALLEST 1
   2588 /* Index within the heap array of least frequent node in the Huffman tree */
   2589 
   2590 
   2591 /*
   2592  * ===========================================================================
   2593  * Remove the smallest element from the heap and recreate the heap with
   2594  * one less element. Updates heap and heap_len.
   2595  */
   2596 #define	pqremove(s, tree, top) \
   2597 {\
   2598 	top = s->heap[SMALLEST]; \
   2599 	s->heap[SMALLEST] = s->heap[s->heap_len--]; \
   2600 	pqdownheap(s, tree, SMALLEST); \
   2601 }
   2602 
   2603 /*
   2604  * ===========================================================================
   2605  * Compares to subtrees, using the tree depth as tie breaker when
   2606  * the subtrees have equal frequency. This minimizes the worst case length.
   2607  */
   2608 #define	smaller(tree, n, m, depth) \
   2609 	(tree[n].Freq < tree[m].Freq || \
   2610 	(tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
   2611 /*
   2612  * ===========================================================================
   2613  * Restore the heap property by moving down the tree starting at node k,
   2614  * exchanging a node with the smallest of its two sons if necessary, stopping
   2615  * when the heap property is re-established (each father smaller than its
   2616  * two sons).
   2617  */
   2618 local void
   2619 pqdownheap(s, tree, k)
   2620     deflate_state *s;
   2621     ct_data *tree;	/* the tree to restore */
   2622     int k;	/* node to move down */
   2623 {
   2624 	int v = s->heap[k];
   2625 	int j = k << 1;	/* left son of k */
   2626 	while (j <= s->heap_len) {
   2627 		/* Set j to the smallest of the two sons: */
   2628 		if (j < s->heap_len &&
   2629 		    smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
   2630 			j++;
   2631 		}
   2632 		/* Exit if v is smaller than both sons */
   2633 		if (smaller(tree, v, s->heap[j], s->depth)) break;
   2634 
   2635 		/* Exchange v with the smallest son */
   2636 		s->heap[k] = s->heap[j];  k = j;
   2637 
   2638 		/* And continue down the tree, setting j to the left son of k */
   2639 		j <<= 1;
   2640 	}
   2641 	s->heap[k] = v;
   2642 }
   2643 
   2644 /*
   2645  * ===========================================================================
   2646  * Compute the optimal bit lengths for a tree and update the total bit length
   2647  * for the current block.
   2648  * IN assertion: the fields freq and dad are set, heap[heap_max] and
   2649  *    above are the tree nodes sorted by increasing frequency.
   2650  * OUT assertions: the field len is set to the optimal bit length, the
   2651  *     array bl_count contains the frequencies for each bit length.
   2652  *     The length opt_len is updated; static_len is also updated if stree is
   2653  *     not null.
   2654  */
   2655 local void
   2656 gen_bitlen(s, desc)
   2657     deflate_state *s;
   2658     tree_desc *desc;	/* the tree descriptor */
   2659 {
   2660 	ct_data *tree  = desc->dyn_tree;
   2661 	int max_code   = desc->max_code;
   2662 	const ct_data *stree = desc->stat_desc->static_tree;
   2663 	const intf *extra    = desc->stat_desc->extra_bits;
   2664 	int base	= desc->stat_desc->extra_base;
   2665 	int max_length = desc->stat_desc->max_length;
   2666 	int h;	/* heap index */
   2667 	int n, m;	/* iterate over the tree elements */
   2668 	int bits;	/* bit length */
   2669 	int xbits;	/* extra bits */
   2670 	ush f;	/* frequency */
   2671 	/* number of elements with bit length too large */
   2672 	int overflow = 0;
   2673 
   2674 	for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
   2675 
   2676 	/*
   2677 	 * In a first pass, compute the optimal bit lengths (which may
   2678 	 * overflow in the case of the bit length tree).
   2679 	 */
   2680 	tree[s->heap[s->heap_max]].Len = 0;	/* root of the heap */
   2681 
   2682 	for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
   2683 		n = s->heap[h];
   2684 		bits = tree[tree[n].Dad].Len + 1;
   2685 		if (bits > max_length) bits = max_length, overflow++;
   2686 		tree[n].Len = (ush)bits;
   2687 		/* We overwrite tree[n].Dad which is no longer needed */
   2688 
   2689 		if (n > max_code) continue;	/* not a leaf node */
   2690 
   2691 		s->bl_count[bits]++;
   2692 		xbits = 0;
   2693 		if (n >= base) xbits = extra[n-base];
   2694 		f = tree[n].Freq;
   2695 		s->opt_len += (ulg)f * (bits + xbits);
   2696 		if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
   2697 	}
   2698 	if (overflow == 0)
   2699 		return;
   2700 
   2701 	Trace((stderr, "\nbit length overflow\n"));
   2702 	/* This happens for example on obj2 and pic of the Calgary corpus */
   2703 
   2704 	/* Find the first bit length which could increase: */
   2705 	do {
   2706 		bits = max_length-1;
   2707 		while (s->bl_count[bits] == 0) bits--;
   2708 		s->bl_count[bits]--;	/* move one leaf down the tree */
   2709 		/* move one overflow item as its brother */
   2710 		s->bl_count[bits+1] += 2;
   2711 		s->bl_count[max_length]--;
   2712 		/*
   2713 		 * The brother of the overflow item also moves one
   2714 		 * step up, but this does not affect
   2715 		 * bl_count[max_length]
   2716 		 */
   2717 		overflow -= 2;
   2718 	} while (overflow > 0);
   2719 
   2720 	/*
   2721 	 * Now recompute all bit lengths, scanning in increasing
   2722 	 * frequency.  h is still equal to HEAP_SIZE. (It is simpler
   2723 	 * to reconstruct all lengths instead of fixing only the wrong
   2724 	 * ones. This idea is taken from 'ar' written by Haruhiko
   2725 	 * Okumura.)
   2726 	 */
   2727 	for (bits = max_length; bits != 0; bits--) {
   2728 		n = s->bl_count[bits];
   2729 		while (n != 0) {
   2730 			m = s->heap[--h];
   2731 			if (m > max_code) continue;
   2732 			if (tree[m].Len != (unsigned)bits) {
   2733 				Trace((stderr, "code %d bits %d->%d\n", m,
   2734 				    tree[m].Len, bits));
   2735 				s->opt_len += ((long)bits - (long)tree[m].Len)
   2736 				    *(long)tree[m].Freq;
   2737 				tree[m].Len = (ush)bits;
   2738 			}
   2739 			n--;
   2740 		}
   2741 	}
   2742 }
   2743 
   2744 /*
   2745  * ===========================================================================
   2746  * Generate the codes for a given tree and bit counts (which need not be
   2747  * optimal).
   2748  * IN assertion: the array bl_count contains the bit length statistics for
   2749  * the given tree and the field len is set for all tree elements.
   2750  * OUT assertion: the field code is set for all tree elements of non
   2751  *     zero code length.
   2752  */
   2753 local void
   2754 gen_codes(tree, max_code, bl_count)
   2755     ct_data *tree;	/* the tree to decorate */
   2756     int max_code;	/* largest code with non zero frequency */
   2757     ushf *bl_count;	/* number of codes at each bit length */
   2758 {
   2759 	/* next code value for each bit length */
   2760 	ush next_code[MAX_BITS+1];
   2761 	ush code = 0;	/* running code value */
   2762 	int bits;	/* bit index */
   2763 	int n;	/* code index */
   2764 
   2765 	/*
   2766 	 * The distribution counts are first used to generate the code
   2767 	 * values without bit reversal.
   2768 	 */
   2769 	for (bits = 1; bits <= MAX_BITS; bits++) {
   2770 		next_code[bits] = code = (code + bl_count[bits-1]) << 1;
   2771 	}
   2772 	/*
   2773 	 * Check that the bit counts in bl_count are consistent. The
   2774 	 * last code must be all ones.
   2775 	 */
   2776 	Assert(code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
   2777 	    "inconsistent bit counts");
   2778 	Tracev((stderr, "\ngen_codes: max_code %d ", max_code));
   2779 
   2780 	for (n = 0;  n <= max_code; n++) {
   2781 		int len = tree[n].Len;
   2782 		if (len == 0) continue;
   2783 		/* Now reverse the bits */
   2784 		tree[n].Code = bi_reverse(next_code[len]++, len);
   2785 
   2786 		Tracecv(tree != static_ltree,
   2787 		    (stderr, "\nn %3d %c l %2d c %4x (%x) ",
   2788 		    n, (isgraph(n) ? n : ' '), len, tree[n].Code,
   2789 			next_code[len]-1));
   2790 	}
   2791 }
   2792 
   2793 /*
   2794  * ===========================================================================
   2795  * Construct one Huffman tree and assigns the code bit strings and lengths.
   2796  * Update the total bit length for the current block.
   2797  * IN assertion: the field freq is set for all tree elements.
   2798  * OUT assertions: the fields len and code are set to the optimal bit length
   2799  *     and corresponding code. The length opt_len is updated; static_len is
   2800  *     also updated if stree is not null. The field max_code is set.
   2801  */
   2802 local void
   2803 build_tree(s, desc)
   2804     deflate_state *s;
   2805     tree_desc *desc;	/* the tree descriptor */
   2806 {
   2807 	ct_data *tree   = desc->dyn_tree;
   2808 	const ct_data *stree  = desc->stat_desc->static_tree;
   2809 	int elems	= desc->stat_desc->elems;
   2810 	int n, m;	/* iterate over heap elements */
   2811 	int max_code = -1;	/* largest code with non zero frequency */
   2812 	int node;	/* new node being created */
   2813 
   2814 	/*
   2815 	 * Construct the initial heap, with least frequent element in
   2816 	 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and
   2817 	 * heap[2*n+1].  heap[0] is not used.
   2818 	 */
   2819 	s->heap_len = 0, s->heap_max = HEAP_SIZE;
   2820 
   2821 	for (n = 0; n < elems; n++) {
   2822 		if (tree[n].Freq != 0) {
   2823 			s->heap[++(s->heap_len)] = max_code = n;
   2824 			s->depth[n] = 0;
   2825 		} else {
   2826 			tree[n].Len = 0;
   2827 		}
   2828 	}
   2829 
   2830 	/*
   2831 	 * The pkzip format requires that at least one distance code
   2832 	 * exists, and that at least one bit should be sent even if
   2833 	 * there is only one possible code. So to avoid special checks
   2834 	 * later on we force at least two codes of non zero frequency.
   2835 	 */
   2836 	while (s->heap_len < 2) {
   2837 		node = s->heap[++(s->heap_len)] = (max_code < 2 ?
   2838 		    ++max_code : 0);
   2839 		tree[node].Freq = 1;
   2840 		s->depth[node] = 0;
   2841 		s->opt_len--; if (stree) s->static_len -= stree[node].Len;
   2842 		/* node is 0 or 1 so it does not have extra bits */
   2843 	}
   2844 	desc->max_code = max_code;
   2845 
   2846 	/*
   2847 	 * The elements heap[heap_len/2+1 .. heap_len] are leaves of
   2848 	 * the tree, establish sub-heaps of increasing lengths:
   2849 	 */
   2850 	for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
   2851 
   2852 	/*
   2853 	 * Construct the Huffman tree by repeatedly combining the
   2854 	 * least two frequent nodes.
   2855 	 */
   2856 	node = elems;	/* next internal node of the tree */
   2857 	do {
   2858 		pqremove(s, tree, n);	/* n = node of least frequency */
   2859 		m = s->heap[SMALLEST];	/* m = node of next least frequency */
   2860 
   2861 		/* keep the nodes sorted by frequency */
   2862 		s->heap[--(s->heap_max)] = n;
   2863 		s->heap[--(s->heap_max)] = m;
   2864 
   2865 		/* Create a new node father of n and m */
   2866 		tree[node].Freq = tree[n].Freq + tree[m].Freq;
   2867 		s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
   2868 		tree[n].Dad = tree[m].Dad = (ush)node;
   2869 #ifdef DUMP_BL_TREE
   2870 		if (tree == s->bl_tree) {
   2871 			fprintf(stderr, "\nnode %d(%d), sons %d(%d) %d(%d)",
   2872 			    node, tree[node].Freq, n, tree[n].Freq, m,
   2873 			    tree[m].Freq);
   2874 		}
   2875 #endif
   2876 		/* and insert the new node in the heap */
   2877 		s->heap[SMALLEST] = node++;
   2878 		pqdownheap(s, tree, SMALLEST);
   2879 
   2880 	} while (s->heap_len >= 2);
   2881 
   2882 	s->heap[--(s->heap_max)] = s->heap[SMALLEST];
   2883 
   2884 	/*
   2885 	 * At this point, the fields freq and dad are set. We can now
   2886 	 * generate the bit lengths.
   2887 	 */
   2888 	gen_bitlen(s, (tree_desc *)desc);
   2889 
   2890 	/* The field len is now set, we can generate the bit codes */
   2891 	gen_codes((ct_data *)tree, max_code, s->bl_count);
   2892 }
   2893 
   2894 /*
   2895  * ===========================================================================
   2896  * Scan a literal or distance tree to determine the frequencies of the codes
   2897  * in the bit length tree.
   2898  */
   2899 local void
   2900 scan_tree(s, tree, max_code)
   2901     deflate_state *s;
   2902     ct_data *tree;	/* the tree to be scanned */
   2903     int max_code;	/* and its largest code of non zero frequency */
   2904 {
   2905 	int n;	/* iterates over all tree elements */
   2906 	int prevlen = -1;	/* last emitted length */
   2907 	int curlen;	/* length of current code */
   2908 	int nextlen = tree[0].Len;	/* length of next code */
   2909 	int count = 0;	/* repeat count of the current code */
   2910 	int max_count = 7;	/* max repeat count */
   2911 	int min_count = 4;	/* min repeat count */
   2912 
   2913 	if (nextlen == 0) max_count = 138, min_count = 3;
   2914 	tree[max_code+1].Len = (ush)0xffff;	/* guard */
   2915 
   2916 	for (n = 0; n <= max_code; n++) {
   2917 		curlen = nextlen; nextlen = tree[n+1].Len;
   2918 		if (++count < max_count && curlen == nextlen) {
   2919 			continue;
   2920 		} else if (count < min_count) {
   2921 			s->bl_tree[curlen].Freq += count;
   2922 		} else if (curlen != 0) {
   2923 			if (curlen != prevlen) s->bl_tree[curlen].Freq++;
   2924 			s->bl_tree[REP_3_6].Freq++;
   2925 		} else if (count <= 10) {
   2926 			s->bl_tree[REPZ_3_10].Freq++;
   2927 		} else {
   2928 			s->bl_tree[REPZ_11_138].Freq++;
   2929 		}
   2930 		count = 0; prevlen = curlen;
   2931 		if (nextlen == 0) {
   2932 			max_count = 138, min_count = 3;
   2933 		} else if (curlen == nextlen) {
   2934 			max_count = 6, min_count = 3;
   2935 		} else {
   2936 			max_count = 7, min_count = 4;
   2937 		}
   2938 	}
   2939 }
   2940 
   2941 /*
   2942  * ===========================================================================
   2943  * Send a literal or distance tree in compressed form, using the codes in
   2944  * bl_tree.
   2945  */
   2946 local void
   2947 send_tree(s, tree, max_code)
   2948     deflate_state *s;
   2949     ct_data *tree;	/* the tree to be scanned */
   2950     int max_code;	/* and its largest code of non zero frequency */
   2951 {
   2952 	int n;	/* iterates over all tree elements */
   2953 	int prevlen = -1;	/* last emitted length */
   2954 	int curlen;	/* length of current code */
   2955 	int nextlen = tree[0].Len;	/* length of next code */
   2956 	int count = 0;	/* repeat count of the current code */
   2957 	int max_count = 7;	/* max repeat count */
   2958 	int min_count = 4;	/* min repeat count */
   2959 
   2960 	/* tree[max_code+1].Len = -1; */  /* guard already set */
   2961 	if (nextlen == 0) max_count = 138, min_count = 3;
   2962 
   2963 	for (n = 0; n <= max_code; n++) {
   2964 		curlen = nextlen; nextlen = tree[n+1].Len;
   2965 		if (++count < max_count && curlen == nextlen) {
   2966 			continue;
   2967 		} else if (count < min_count) {
   2968 			do { send_code(s, curlen, s->bl_tree); }
   2969 			while (--count != 0);
   2970 
   2971 		} else if (curlen != 0) {
   2972 			if (curlen != prevlen) {
   2973 				send_code(s, curlen, s->bl_tree); count--;
   2974 			}
   2975 			Assert(count >= 3 && count <= 6, " 3_6?");
   2976 			send_code(s, REP_3_6, s->bl_tree);
   2977 			send_bits(s, count-3, 2);
   2978 
   2979 		} else if (count <= 10) {
   2980 			send_code(s, REPZ_3_10, s->bl_tree);
   2981 			send_bits(s, count-3, 3);
   2982 
   2983 		} else {
   2984 			send_code(s, REPZ_11_138, s->bl_tree);
   2985 			send_bits(s, count-11, 7);
   2986 		}
   2987 		count = 0; prevlen = curlen;
   2988 		if (nextlen == 0) {
   2989 			max_count = 138, min_count = 3;
   2990 		} else if (curlen == nextlen) {
   2991 			max_count = 6, min_count = 3;
   2992 		} else {
   2993 			max_count = 7, min_count = 4;
   2994 		}
   2995 	}
   2996 }
   2997 
   2998 /*
   2999  * ===========================================================================
   3000  * Construct the Huffman tree for the bit lengths and return the index in
   3001  * bl_order of the last bit length code to send.
   3002  */
   3003 local int
   3004 build_bl_tree(s)
   3005     deflate_state *s;
   3006 {
   3007 	/* index of last bit length code of non zero freq */
   3008 	int max_blindex;
   3009 
   3010 	/*
   3011 	 * Determine the bit length frequencies for literal and
   3012 	 * distance trees
   3013 	 */
   3014 	scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
   3015 	scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
   3016 
   3017 	/* Build the bit length tree: */
   3018 	build_tree(s, (tree_desc *)(&(s->bl_desc)));
   3019 	/*
   3020 	 * opt_len now includes the length of the tree
   3021 	 * representations, except the lengths of the bit lengths
   3022 	 * codes and the 5+5+4 bits for the counts.
   3023 	 */
   3024 
   3025 	/*
   3026 	 * Determine the number of bit length codes to send. The pkzip
   3027 	 * format requires that at least 4 bit length codes be
   3028 	 * sent. (appnote.txt says 3 but the actual value used is 4.)
   3029 	 */
   3030 	for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
   3031 		if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
   3032 	}
   3033 	/* Update opt_len to include the bit length tree and counts */
   3034 	s->opt_len += 3*(max_blindex+1) + 5+5+4;
   3035 	Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
   3036 	    s->opt_len, s->static_len));
   3037 
   3038 	return (max_blindex);
   3039 }
   3040 
   3041 /*
   3042  * ===========================================================================
   3043  * Send the header for a block using dynamic Huffman trees: the counts, the
   3044  * lengths of the bit length codes, the literal tree and the distance tree.
   3045  * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
   3046  */
   3047 local void
   3048 send_all_trees(s, lcodes, dcodes, blcodes)
   3049     deflate_state *s;
   3050     int lcodes, dcodes, blcodes;	/* number of codes for each tree */
   3051 {
   3052 	int rank;	/* index in bl_order */
   3053 
   3054 	Assert(lcodes >= 257 && dcodes >= 1 && blcodes >= 4,
   3055 	    "not enough codes");
   3056 	Assert(lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
   3057 	    "too many codes");
   3058 	Tracev((stderr, "\nbl counts: "));
   3059 	send_bits(s, lcodes-257, 5);	/* not +255 as stated in appnote.txt */
   3060 	send_bits(s, dcodes-1,   5);
   3061 	send_bits(s, blcodes-4,  4);	/* not -3 as stated in appnote.txt */
   3062 	for (rank = 0; rank < blcodes; rank++) {
   3063 		Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
   3064 		send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
   3065 	}
   3066 #ifdef DEBUG_ZLIB
   3067 	Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
   3068 #endif
   3069 
   3070 	/* literal tree */
   3071 	send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1);
   3072 #ifdef DEBUG_ZLIB
   3073 	Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
   3074 #endif
   3075 
   3076 	/* distance tree */
   3077 	send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1);
   3078 #ifdef DEBUG_ZLIB
   3079 	Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
   3080 #endif
   3081 }
   3082 
   3083 /*
   3084  * ===========================================================================
   3085  * Send a stored block
   3086  */
   3087 void
   3088 _tr_stored_block(s, buf, stored_len, eof)
   3089     deflate_state *s;
   3090     charf *buf;	/* input block */
   3091     ulg stored_len;	/* length of input block */
   3092     int eof;	/* true if this is the last block for a file */
   3093 {
   3094 	send_bits(s, (STORED_BLOCK<<1)+eof, 3);	/* send block type */
   3095 	s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; /* PPP */
   3096 	s->compressed_len += (stored_len + 4) << 3;	/* PPP */
   3097 
   3098 	copy_block(s, buf, (unsigned)stored_len, 1);	/* with header */
   3099 }
   3100 
   3101 /*
   3102  * Send just the `stored block' type code without any length bytes or data.
   3103  * ---PPP---
   3104  */
   3105 void
   3106 _tr_stored_type_only(s)
   3107     deflate_state *s;
   3108 {
   3109 	send_bits(s, (STORED_BLOCK << 1), 3);
   3110 	bi_windup(s);
   3111 	s->compressed_len = (s->compressed_len + 3) & ~7L;	/* PPP */
   3112 }
   3113 
   3114 
   3115 /*
   3116  * ===========================================================================
   3117  * Send one empty static block to give enough lookahead for inflate.
   3118  * This takes 10 bits, of which 7 may remain in the bit buffer.
   3119  * The current inflate code requires 9 bits of lookahead. If the
   3120  * last two codes for the previous block (real code plus EOB) were coded
   3121  * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
   3122  * the last real code. In this case we send two empty static blocks instead
   3123  * of one. (There are no problems if the previous block is stored or fixed.)
   3124  * To simplify the code, we assume the worst case of last real code encoded
   3125  * on one bit only.
   3126  */
   3127 void
   3128 _tr_align(s)
   3129     deflate_state *s;
   3130 {
   3131 	send_bits(s, STATIC_TREES<<1, 3);
   3132 	send_code(s, END_BLOCK, static_ltree);
   3133 	s->compressed_len += 10L;	/* 3 for block type, 7 for EOB */
   3134 	bi_flush(s);
   3135 	/*
   3136 	 * Of the 10 bits for the empty block, we have already sent
   3137 	 * (10 - bi_valid) bits. The lookahead for the last real code
   3138 	 * (before the EOB of the previous block) was thus at least
   3139 	 * one plus the length of the EOB plus what we have just sent
   3140 	 * of the empty static block.
   3141 	 */
   3142 	if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
   3143 		send_bits(s, STATIC_TREES<<1, 3);
   3144 		send_code(s, END_BLOCK, static_ltree);
   3145 		s->compressed_len += 10L;
   3146 		bi_flush(s);
   3147 	}
   3148 	s->last_eob_len = 7;
   3149 }
   3150 
   3151 /*
   3152  * ===========================================================================
   3153  * Determine the best encoding for the current block: dynamic trees, static
   3154  * trees or store, and output the encoded block to the zip file.
   3155  */
   3156 void
   3157 _tr_flush_block(s, buf, stored_len, eof)
   3158     deflate_state *s;
   3159     charf *buf;	/* input block, or NULL if too old */
   3160     ulg stored_len;	/* length of input block */
   3161     int eof;	/* true if this is the last block for a file */
   3162 {
   3163 	ulg opt_lenb, static_lenb;	/* opt_len and static_len in bytes */
   3164 	/* index of last bit length code of non zero freq */
   3165 	int max_blindex = 0;
   3166 
   3167 	/* Build the Huffman trees unless a stored block is forced */
   3168 	if (s->level > 0) {
   3169 
   3170 		/* Check if the file is ascii or binary */
   3171 		if (s->data_type == Z_UNKNOWN) set_data_type(s);
   3172 
   3173 		/* Construct the literal and distance trees */
   3174 		build_tree(s, (tree_desc *)(&(s->l_desc)));
   3175 		Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
   3176 		    s->static_len));
   3177 
   3178 		build_tree(s, (tree_desc *)(&(s->d_desc)));
   3179 		Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
   3180 		    s->static_len));
   3181 		/*
   3182 		 * At this point, opt_len and static_len are the total
   3183 		 * bit lengths of the compressed block data, excluding
   3184 		 * the tree representations.
   3185 		 */
   3186 
   3187 		/*
   3188 		 * Build the bit length tree for the above two trees,
   3189 		 * and get the index in bl_order of the last bit
   3190 		 * length code to send.
   3191 		 */
   3192 		max_blindex = build_bl_tree(s);
   3193 
   3194 		/*
   3195 		 * Determine the best encoding. Compute first the
   3196 		 * block length in bytes
   3197 		 */
   3198 		opt_lenb = (s->opt_len+3+7)>>3;
   3199 		static_lenb = (s->static_len+3+7)>>3;
   3200 
   3201 		Tracev((stderr,
   3202 		    "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
   3203 		    opt_lenb, s->opt_len, static_lenb, s->static_len,
   3204 		    stored_len, s->last_lit));
   3205 
   3206 		if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
   3207 
   3208 	} else {
   3209 		Assert(buf != (char *)0, "lost buf");
   3210 		/* force a stored block */
   3211 		opt_lenb = static_lenb = stored_len + 5;
   3212 	}
   3213 
   3214 	/*
   3215 	 * If compression failed and this is the first and last block,
   3216 	 * and if the .zip file can be seeked (to rewrite the local
   3217 	 * header), the whole file is transformed into a stored file:
   3218 	 */
   3219 #ifdef STORED_FILE_OK
   3220 #ifdef FORCE_STORED_FILE
   3221 #define	FRC_STR_COND	eof && s->compressed_len == 0L /* force stored file */
   3222 #else
   3223 #define	FRC_STR_COND	stored_len <= opt_lenb && eof && \
   3224 			s->compressed_len == 0L && seekable()
   3225 #endif
   3226 	if (FRC_STR_COND) {
   3227 #undef FRC_STR_COND
   3228 		/*
   3229 		 * Since LIT_BUFSIZE <= 2*WSIZE, the input data must
   3230 		 * be there:
   3231 		 */
   3232 		if (buf == (charf*)0) error("block vanished");
   3233 
   3234 		/* without header */
   3235 		copy_block(s, buf, (unsigned)stored_len, 0);
   3236 		s->compressed_len = stored_len << 3;
   3237 		s->method = STORED;
   3238 	} else
   3239 #endif /* STORED_FILE_OK */
   3240 
   3241 #ifdef FORCE_STORED
   3242 #define	FRC_STR_COND	buf != (char *)0	/* force stored block */
   3243 #else
   3244 			/* 4: two words for the lengths */
   3245 #define	FRC_STR_COND	stored_len+4 <= opt_lenb && buf != (char *)0
   3246 #endif
   3247 		if (FRC_STR_COND) {
   3248 #undef FRC_STR_COND
   3249 			/*
   3250 			 * The test buf != NULL is only necessary if
   3251 			 * LIT_BUFSIZE > WSIZE.  Otherwise we can't
   3252 			 * have processed more than WSIZE input bytes
   3253 			 * since the last block flush, because
   3254 			 * compression would have been successful. If
   3255 			 * LIT_BUFSIZE <= WSIZE, it is never too late
   3256 			 * to transform a block into a stored block.
   3257 			 */
   3258 			_tr_stored_block(s, buf, stored_len, eof);
   3259 #ifdef FORCE_STATIC
   3260 #define	FRC_STAT_COND	static_lenb >= 0 /* force static trees */
   3261 #else
   3262 #define	FRC_STAT_COND	static_lenb == opt_lenb
   3263 #endif
   3264 		} else if (FRC_STAT_COND) {
   3265 #undef FRC_STAT_COND
   3266 			send_bits(s, (STATIC_TREES<<1)+eof, 3);
   3267 			compress_block(s, (ct_data *)static_ltree,
   3268 			    (ct_data *)static_dtree);
   3269 			s->compressed_len += 3 + s->static_len;	/* PPP */
   3270 		} else {
   3271 			send_bits(s, (DYN_TREES<<1)+eof, 3);
   3272 			send_all_trees(s, s->l_desc.max_code+1,
   3273 			    s->d_desc.max_code+1,
   3274 			    max_blindex+1);
   3275 			compress_block(s, (ct_data *)s->dyn_ltree,
   3276 			    (ct_data *)s->dyn_dtree);
   3277 			s->compressed_len += 3 + s->opt_len;	/* PPP */
   3278 		}
   3279 #ifdef DEBUG_ZLIB
   3280 	Assert(s->compressed_len == s->bits_sent, "bad compressed size");
   3281 #endif
   3282 	/*
   3283 	 * The above check is made mod 2^32, for files larger than 512
   3284 	 * MB and uLong implemented on 32 bits.
   3285 	 */
   3286 	init_block(s);
   3287 
   3288 	if (eof) {
   3289 		bi_windup(s);
   3290 		s->compressed_len += 7;	/* align on byte boundary PPP */
   3291 	}
   3292 	Tracev((stderr, "\ncomprlen %lu(%lu) ", s->compressed_len>>3,
   3293 	    s->compressed_len-7*eof));
   3294 
   3295 	/* return (s->compressed_len >> 3); */
   3296 }
   3297 
   3298 /*
   3299  * ===========================================================================
   3300  * Save the match info and tally the frequency counts. Return true if
   3301  * the current block must be flushed.
   3302  */
   3303 int
   3304 _tr_tally(s, dist, lc)
   3305     deflate_state *s;
   3306     unsigned dist;	/* distance of matched string */
   3307 	/* match length-MIN_MATCH or unmatched char (if dist==0) */
   3308     unsigned lc;
   3309 {
   3310 	s->d_buf[s->last_lit] = (ush)dist;
   3311 	s->l_buf[s->last_lit++] = (uch)lc;
   3312 	if (dist == 0) {
   3313 		/* lc is the unmatched char */
   3314 		s->dyn_ltree[lc].Freq++;
   3315 	} else {
   3316 		s->matches++;
   3317 		/* Here, lc is the match length - MIN_MATCH */
   3318 		dist--;	/* dist = match distance - 1 */
   3319 		Assert((ush)dist < (ush)MAX_DIST(s) &&
   3320 		    (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
   3321 		    (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");
   3322 
   3323 		s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
   3324 		s->dyn_dtree[d_code(dist)].Freq++;
   3325 	}
   3326 
   3327 #ifdef TRUNCATE_BLOCK
   3328 	/* Try to guess if it is profitable to stop the current block here */
   3329 	if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
   3330 		/* Compute an upper bound for the compressed length */
   3331 		ulg out_length = (ulg)s->last_lit*8L;
   3332 		ulg in_length = (ulg)((long)s->strstart - s->block_start);
   3333 		int dcode;
   3334 		for (dcode = 0; dcode < D_CODES; dcode++) {
   3335 			out_length += (ulg)s->dyn_dtree[dcode].Freq *
   3336 			    (5L+extra_dbits[dcode]);
   3337 		}
   3338 		out_length >>= 3;
   3339 		Tracev((stderr, "\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
   3340 		    s->last_lit, in_length, out_length,
   3341 		    100L - out_length*100L/in_length));
   3342 		if (s->matches < s->last_lit/2 && out_length < in_length/2)
   3343 			return (1);
   3344 	}
   3345 #endif
   3346 	return (s->last_lit == s->lit_bufsize-1);
   3347 	/*
   3348 	 * We avoid equality with lit_bufsize because of wraparound at 64K
   3349 	 * on 16 bit machines and because stored blocks are restricted to
   3350 	 * 64K-1 bytes.
   3351 	 */
   3352 }
   3353 
   3354 /*
   3355  * ===========================================================================
   3356  * Send the block data compressed using the given Huffman trees
   3357  */
   3358 local void
   3359 compress_block(s, ltree, dtree)
   3360     deflate_state *s;
   3361     ct_data *ltree;	/* literal tree */
   3362     ct_data *dtree;	/* distance tree */
   3363 {
   3364 	unsigned dist;	/* distance of matched string */
   3365 	int lc;	/* match length or unmatched char (if dist == 0) */
   3366 	unsigned lx = 0;	/* running index in l_buf */
   3367 	unsigned code;	/* the code to send */
   3368 	int extra;	/* number of extra bits to send */
   3369 
   3370 	if (s->last_lit != 0) do {
   3371 		dist = s->d_buf[lx];
   3372 		lc = s->l_buf[lx++];
   3373 		if (dist == 0) {
   3374 			/* send a literal byte */
   3375 			send_code(s, lc, ltree);
   3376 			Tracecv(isgraph(lc), (stderr, " '%c' ", lc));
   3377 		} else {
   3378 			/* Here, lc is the match length - MIN_MATCH */
   3379 			code = _length_code[lc];
   3380 			/* send the length code */
   3381 			send_code(s, code+LITERALS+1, ltree);
   3382 			extra = extra_lbits[code];
   3383 			if (extra != 0) {
   3384 				lc -= base_length[code];
   3385 				/* send the extra length bits */
   3386 				send_bits(s, lc, extra);
   3387 			}
   3388 			/* dist is now the match distance - 1 */
   3389 			dist--;
   3390 			code = d_code(dist);
   3391 			Assert(code < D_CODES, "bad d_code");
   3392 
   3393 			/* send the distance code */
   3394 			send_code(s, code, dtree);
   3395 			extra = extra_dbits[code];
   3396 			if (extra != 0) {
   3397 				dist -= base_dist[code];
   3398 				/* send the extra distance bits */
   3399 				send_bits(s, dist, extra);
   3400 			}
   3401 		} /* literal or match pair ? */
   3402 
   3403 		/*
   3404 		 * Check that the overlay between pending_buf and
   3405 		 * d_buf+l_buf is ok:
   3406 		 */
   3407 		Assert(s->pending < s->lit_bufsize + 2*lx,
   3408 		    "pendingBuf overflow");
   3409 
   3410 	} while (lx < s->last_lit);
   3411 
   3412 	send_code(s, END_BLOCK, ltree);
   3413 	s->last_eob_len = ltree[END_BLOCK].Len;
   3414 }
   3415 
   3416 /*
   3417  * ===========================================================================
   3418  * Set the data type to ASCII or BINARY, using a crude approximation:
   3419  * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
   3420  * IN assertion: the fields freq of dyn_ltree are set and the total of all
   3421  * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
   3422  */
   3423 local void
   3424 set_data_type(s)
   3425     deflate_state *s;
   3426 {
   3427 	int n = 0;
   3428 	unsigned ascii_freq = 0;
   3429 	unsigned bin_freq = 0;
   3430 	while (n < 7)	bin_freq	+= s->dyn_ltree[n++].Freq;
   3431 	while (n < 128)	ascii_freq	+= s->dyn_ltree[n++].Freq;
   3432 	while (n < LITERALS) bin_freq	+= s->dyn_ltree[n++].Freq;
   3433 	s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ?
   3434 	    Z_BINARY : Z_ASCII);
   3435 }
   3436 
   3437 /*
   3438  * ===========================================================================
   3439  * Reverse the first len bits of a code, using straightforward code (a faster
   3440  * method would use a table)
   3441  * IN assertion: 1 <= len <= 15
   3442  */
   3443 local unsigned
   3444 bi_reverse(code, len)
   3445     unsigned code;	/* the value to invert */
   3446     int len;	/* its bit length */
   3447 {
   3448 	register unsigned res = 0;
   3449 	do {
   3450 		res |= code & 1;
   3451 		code >>= 1, res <<= 1;
   3452 	} while (--len > 0);
   3453 	return (res >> 1);
   3454 }
   3455 
   3456 /*
   3457  * ===========================================================================
   3458  * Flush the bit buffer, keeping at most 7 bits in it.
   3459  */
   3460 local void
   3461 bi_flush(s)
   3462     deflate_state *s;
   3463 {
   3464 	if (s->bi_valid == 16) {
   3465 		put_short(s, s->bi_buf);
   3466 		s->bi_buf = 0;
   3467 		s->bi_valid = 0;
   3468 	} else if (s->bi_valid >= 8) {
   3469 		put_byte(s, (Byte)s->bi_buf);
   3470 		s->bi_buf >>= 8;
   3471 		s->bi_valid -= 8;
   3472 	}
   3473 }
   3474 
   3475 /*
   3476  * ===========================================================================
   3477  * Flush the bit buffer and align the output on a byte boundary
   3478  */
   3479 local void
   3480 bi_windup(s)
   3481     deflate_state *s;
   3482 {
   3483 	if (s->bi_valid > 8) {
   3484 		put_short(s, s->bi_buf);
   3485 	} else if (s->bi_valid > 0) {
   3486 		put_byte(s, (Byte)s->bi_buf);
   3487 	}
   3488 	s->bi_buf = 0;
   3489 	s->bi_valid = 0;
   3490 #ifdef DEBUG_ZLIB
   3491 	s->bits_sent = (s->bits_sent+7) & ~7;
   3492 #endif
   3493 }
   3494 
   3495 /*
   3496  * ===========================================================================
   3497  * Copy a stored block, storing first the length and its
   3498  * one's complement if requested.
   3499  */
   3500 local void
   3501 copy_block(s, buf, len, header)
   3502     deflate_state *s;
   3503     charf    *buf;	/* the input data */
   3504     unsigned len;	/* its length */
   3505     int	header;	/* true if block header must be written */
   3506 {
   3507 	bi_windup(s);	/* align on byte boundary */
   3508 	s->last_eob_len = 8;	/* enough lookahead for inflate */
   3509 
   3510 	if (header) {
   3511 		put_short(s, (ush)len);
   3512 		put_short(s, (ush)~len);
   3513 #ifdef DEBUG_ZLIB
   3514 		s->bits_sent += 2*16;
   3515 #endif
   3516 	}
   3517 #ifdef DEBUG_ZLIB
   3518 	s->bits_sent += (ulg)len<<3;
   3519 #endif
   3520 	/* bundle up the put_byte(s, *buf++) calls PPP */
   3521 	Assert(s->pending + len < s->pending_buf_size, "pending_buf overrun");
   3522 	zmemcpy(&s->pending_buf[s->pending], buf, len);	/* PPP */
   3523 	s->pending += len;				/* PPP */
   3524 }
   3525 /* --- trees.c */
   3526 
   3527 /* +++ inflate.c */
   3528 /*
   3529  * inflate.c -- zlib interface to inflate modules
   3530  * Copyright (C) 1995-1998 Mark Adler
   3531  * For conditions of distribution and use, see copyright notice in zlib.h
   3532  */
   3533 
   3534 /* #include "zutil.h" */
   3535 
   3536 /* +++ infblock.h */
   3537 /*
   3538  * infblock.h -- header to use infblock.c
   3539  * Copyright (C) 1995-1998 Mark Adler
   3540  * For conditions of distribution and use, see copyright notice in zlib.h
   3541  */
   3542 
   3543 /*
   3544  * WARNING: this file should *not* be used by applications. It is part
   3545  * of the implementation of the compression library and is subject to
   3546  * change. Applications should only use zlib.h.
   3547  */
   3548 
   3549 struct inflate_blocks_state;
   3550 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
   3551 
   3552 extern inflate_blocks_statef * inflate_blocks_new OF((
   3553     z_streamp z,
   3554     check_func c,	/* check function */
   3555     uInt w));	/* window size */
   3556 
   3557 extern int inflate_blocks OF((
   3558     inflate_blocks_statef *,
   3559     z_streamp,
   3560     int));	/* initial return code */
   3561 
   3562 extern void inflate_blocks_reset OF((
   3563     inflate_blocks_statef *,
   3564     z_streamp,
   3565     uLongf *));	/* check value on output */
   3566 
   3567 extern int inflate_blocks_free OF((
   3568     inflate_blocks_statef *,
   3569     z_streamp));
   3570 
   3571 extern void inflate_set_dictionary OF((
   3572     inflate_blocks_statef *s,
   3573     const Bytef *d,  /* dictionary */
   3574     uInt  n));	/* dictionary length */
   3575 
   3576 extern int inflate_blocks_sync_point OF((
   3577     inflate_blocks_statef *s));
   3578 
   3579 /* PPP -- added function */
   3580 extern int inflate_addhistory OF((
   3581     inflate_blocks_statef *,
   3582     z_streamp));
   3583 
   3584 /* PPP -- added function */
   3585 extern int inflate_packet_flush OF((
   3586     inflate_blocks_statef *));
   3587 /* --- infblock.h */
   3588 
   3589 #ifndef NO_DUMMY_DECL
   3590 struct inflate_blocks_state {int dummy; };	/* for buggy compilers */
   3591 #endif
   3592 
   3593 /* inflate private state */
   3594 struct internal_state {
   3595 
   3596 	/* mode */
   3597 	enum {
   3598 		METHOD,	/* waiting for method byte */
   3599 		FLAG,	/* waiting for flag byte */
   3600 		DICT4,	/* four dictionary check bytes to go */
   3601 		DICT3,	/* three dictionary check bytes to go */
   3602 		DICT2,	/* two dictionary check bytes to go */
   3603 		DICT1,	/* one dictionary check byte to go */
   3604 		DICT0,	/* waiting for inflateSetDictionary */
   3605 		BLOCKS,	/* decompressing blocks */
   3606 		CHECK4,	/* four check bytes to go */
   3607 		CHECK3,	/* three check bytes to go */
   3608 		CHECK2,	/* two check bytes to go */
   3609 		CHECK1,	/* one check byte to go */
   3610 		DONE,	/* finished check, done */
   3611 		BAD}	/* got an error--stay here */
   3612 	mode;	/* current inflate mode */
   3613 
   3614 	/* mode dependent information */
   3615 	union {
   3616 		uInt method;	/* if FLAGS, method byte */
   3617 		struct {
   3618 			uLong was;	/* computed check value */
   3619 			uLong need;	/* stream check value */
   3620 		} check;	/* if CHECK, check values to compare */
   3621 		uInt marker;	/* if BAD, inflateSync's marker bytes count */
   3622 	} sub;	/* submode */
   3623 
   3624 	/* mode independent information */
   3625 	int  nowrap;	/* flag for no wrapper */
   3626 	uInt wbits;	/* log2(window size)  (8..15, defaults to 15) */
   3627 	/* current inflate_blocks state */
   3628 	inflate_blocks_statef *blocks;
   3629 };
   3630 
   3631 
   3632 int
   3633 inflateReset(z)
   3634 z_streamp z;
   3635 {
   3636 	if (z == Z_NULL || z->state == Z_NULL)
   3637 		return (Z_STREAM_ERROR);
   3638 	z->total_in = z->total_out = 0;
   3639 	z->msg = Z_NULL;
   3640 	z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
   3641 	inflate_blocks_reset(z->state->blocks, z, Z_NULL);
   3642 	Trace((stderr, "inflate: reset\n"));
   3643 	return (Z_OK);
   3644 }
   3645 
   3646 
   3647 int
   3648 inflateEnd(z)
   3649 z_streamp z;
   3650 {
   3651 	if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
   3652 		return (Z_STREAM_ERROR);
   3653 	if (z->state->blocks != Z_NULL) {
   3654 		(void) inflate_blocks_free(z->state->blocks, z);
   3655 		z->state->blocks = Z_NULL;
   3656 	}
   3657 	ZFREE(z, z->state);
   3658 	z->state = Z_NULL;
   3659 	Trace((stderr, "inflate: end\n"));
   3660 	return (Z_OK);
   3661 }
   3662 
   3663 
   3664 int
   3665 inflateInit2_(z, w, version, stream_size)
   3666 z_streamp z;
   3667 int w;
   3668 const char *version;
   3669 int stream_size;
   3670 {
   3671 	if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
   3672 	    stream_size != sizeof (z_stream))
   3673 		return (Z_VERSION_ERROR);
   3674 
   3675 	/* initialize state */
   3676 	if (z == Z_NULL)
   3677 		return (Z_STREAM_ERROR);
   3678 	z->msg = Z_NULL;
   3679 #ifndef NO_ZCFUNCS
   3680 	if (z->zalloc == Z_NULL)
   3681 	{
   3682 		z->zalloc = zcalloc;
   3683 		z->opaque = (voidpf)0;
   3684 	}
   3685 	if (z->zfree == Z_NULL) z->zfree = zcfree;
   3686 #endif
   3687 	if ((z->state = (struct internal_state FAR *)
   3688 	    ZALLOC(z, 1, sizeof (struct internal_state))) == Z_NULL)
   3689 		return (Z_MEM_ERROR);
   3690 	z->state->blocks = Z_NULL;
   3691 
   3692 	/* handle undocumented nowrap option (no zlib header or check) */
   3693 	z->state->nowrap = 0;
   3694 	if (w < 0)
   3695 	{
   3696 		w = - w;
   3697 		z->state->nowrap = 1;
   3698 	}
   3699 
   3700 	/* set window size */
   3701 	if (w < 8 || w > 15)
   3702 	{
   3703 		(void) inflateEnd(z);
   3704 		return (Z_STREAM_ERROR);
   3705 	}
   3706 	z->state->wbits = (uInt)w;
   3707 
   3708 	/* create inflate_blocks state */
   3709 	if ((z->state->blocks =
   3710 	    inflate_blocks_new(z, z->state->nowrap ?
   3711 		Z_NULL : adler32, (uInt)1 << w))
   3712 	    == Z_NULL)
   3713 	{
   3714 		(void) inflateEnd(z);
   3715 		return (Z_MEM_ERROR);
   3716 	}
   3717 	Trace((stderr, "inflate: allocated\n"));
   3718 
   3719 	/* reset state */
   3720 	(void) inflateReset(z);
   3721 	return (Z_OK);
   3722 }
   3723 
   3724 
   3725 int
   3726 inflateInit_(z, version, stream_size)
   3727 z_streamp z;
   3728 const char *version;
   3729 int stream_size;
   3730 {
   3731 	return (inflateInit2_(z, DEF_WBITS, version, stream_size));
   3732 }
   3733 
   3734 /* PPP -- added "empty" label and changed f to Z_OK */
   3735 #define	NEEDBYTE {if (z->avail_in == 0) goto empty; r = Z_OK; } ((void)0)
   3736 #define	NEXTBYTE (z->avail_in--, z->total_in++, *z->next_in++)
   3737 
   3738 int
   3739 inflate(z, f)
   3740 z_streamp z;
   3741 int f;
   3742 {
   3743 	int r;
   3744 	uInt b;
   3745 
   3746 	if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
   3747 		return (Z_STREAM_ERROR);
   3748 	/* f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK; -- PPP; Z_FINISH unused */
   3749 	r = Z_BUF_ERROR;
   3750 	/* CONSTCOND */
   3751 	while (1)
   3752 		switch (z->state->mode)
   3753 	{
   3754 	case METHOD:
   3755 		NEEDBYTE;
   3756 		if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
   3757 		{
   3758 			z->state->mode = BAD;
   3759 			z->msg = "unknown compression method";
   3760 			/* can't try inflateSync */
   3761 			z->state->sub.marker = 5;
   3762 			break;
   3763 		}
   3764 		if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
   3765 		{
   3766 			z->state->mode = BAD;
   3767 			z->msg = "invalid window size";
   3768 			/* can't try inflateSync */
   3769 			z->state->sub.marker = 5;
   3770 			break;
   3771 		}
   3772 		z->state->mode = FLAG;
   3773 		/* FALLTHRU */
   3774 	case FLAG:
   3775 		NEEDBYTE;
   3776 		b = NEXTBYTE;
   3777 		if (((z->state->sub.method << 8) + b) % 31)
   3778 		{
   3779 			z->state->mode = BAD;
   3780 			z->msg = "incorrect header check";
   3781 			/* can't try inflateSync */
   3782 			z->state->sub.marker = 5;
   3783 			break;
   3784 		}
   3785 		Trace((stderr, "inflate: zlib header ok\n"));
   3786 		if (!(b & PRESET_DICT))
   3787 		{
   3788 			z->state->mode = BLOCKS;
   3789 			break;
   3790 		}
   3791 		z->state->mode = DICT4;
   3792 		/* FALLTHRU */
   3793 	case DICT4:
   3794 		NEEDBYTE;
   3795 		z->state->sub.check.need = (uLong)NEXTBYTE << 24;
   3796 		z->state->mode = DICT3;
   3797 		/* FALLTHRU */
   3798 	case DICT3:
   3799 		NEEDBYTE;
   3800 		z->state->sub.check.need += (uLong)NEXTBYTE << 16;
   3801 		z->state->mode = DICT2;
   3802 		/* FALLTHRU */
   3803 	case DICT2:
   3804 		NEEDBYTE;
   3805 		z->state->sub.check.need += (uLong)NEXTBYTE << 8;
   3806 		z->state->mode = DICT1;
   3807 		/* FALLTHRU */
   3808 	case DICT1:
   3809 		NEEDBYTE;
   3810 		z->state->sub.check.need += (uLong)NEXTBYTE;
   3811 		z->adler = z->state->sub.check.need;
   3812 		z->state->mode = DICT0;
   3813 		return (Z_NEED_DICT);
   3814 	case DICT0:
   3815 		z->state->mode = BAD;
   3816 		z->msg = "need dictionary";
   3817 		z->state->sub.marker = 0;	/* can try inflateSync */
   3818 		return (Z_STREAM_ERROR);
   3819 	case BLOCKS:
   3820 		r = inflate_blocks(z->state->blocks, z, r);
   3821 		if (f == Z_PACKET_FLUSH && z->avail_in == 0 &&	/* PPP */
   3822 		    z->avail_out != 0)				/* PPP */
   3823 			r = inflate_packet_flush(z->state->blocks); /* PPP */
   3824 		if (r == Z_DATA_ERROR)
   3825 		{
   3826 			z->state->mode = BAD;
   3827 			/* can try inflateSync */
   3828 			z->state->sub.marker = 0;
   3829 			break;
   3830 		}
   3831 		/* PPP */
   3832 		if (r != Z_STREAM_END)
   3833 			return (r);
   3834 		r = Z_OK;	/* PPP */
   3835 		inflate_blocks_reset(z->state->blocks, z,
   3836 		    &z->state->sub.check.was);
   3837 		if (z->state->nowrap)
   3838 		{
   3839 			z->state->mode = DONE;
   3840 			break;
   3841 		}
   3842 		z->state->mode = CHECK4;
   3843 		/* FALLTHRU */
   3844 	case CHECK4:
   3845 		NEEDBYTE;
   3846 		z->state->sub.check.need = (uLong)NEXTBYTE << 24;
   3847 		z->state->mode = CHECK3;
   3848 		/* FALLTHRU */
   3849 	case CHECK3:
   3850 		NEEDBYTE;
   3851 		z->state->sub.check.need += (uLong)NEXTBYTE << 16;
   3852 		z->state->mode = CHECK2;
   3853 		/* FALLTHRU */
   3854 	case CHECK2:
   3855 		NEEDBYTE;
   3856 		z->state->sub.check.need += (uLong)NEXTBYTE << 8;
   3857 		z->state->mode = CHECK1;
   3858 		/* FALLTHRU */
   3859 	case CHECK1:
   3860 		NEEDBYTE;
   3861 		z->state->sub.check.need += (uLong)NEXTBYTE;
   3862 
   3863 		if (z->state->sub.check.was != z->state->sub.check.need)
   3864 		{
   3865 			z->state->mode = BAD;
   3866 			z->msg = "incorrect data check";
   3867 			/* can't try inflateSync */
   3868 			z->state->sub.marker = 5;
   3869 			break;
   3870 		}
   3871 		Trace((stderr, "inflate: zlib check ok\n"));
   3872 		z->state->mode = DONE;
   3873 		/* FALLTHRU */
   3874 	case DONE:
   3875 		return (Z_STREAM_END);
   3876 	case BAD:
   3877 		return (Z_DATA_ERROR);
   3878 	default:
   3879 		return (Z_STREAM_ERROR);
   3880 	}
   3881 
   3882 /* PPP -- packet flush handling */
   3883 empty:
   3884 	if (f != Z_PACKET_FLUSH)
   3885 		return (r);
   3886 	z->state->mode = BAD;
   3887 	z->msg = "need more for packet flush";
   3888 	z->state->sub.marker = 0;	/* can try inflateSync */
   3889 	return (Z_DATA_ERROR);
   3890 }
   3891 
   3892 
   3893 int
   3894 inflateSetDictionary(z, dictionary, dictLength)
   3895 z_streamp z;
   3896 const Bytef *dictionary;
   3897 uInt  dictLength;
   3898 {
   3899 	uInt length = dictLength;
   3900 
   3901 	if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
   3902 		return (Z_STREAM_ERROR);
   3903 
   3904 	if (adler32(1L, dictionary, dictLength) != z->adler)
   3905 		return (Z_DATA_ERROR);
   3906 	z->adler = 1L;
   3907 
   3908 	if (length >= ((uInt)1<<z->state->wbits))
   3909 	{
   3910 		length = (1<<z->state->wbits)-1;
   3911 		dictionary += dictLength - length;
   3912 	}
   3913 	inflate_set_dictionary(z->state->blocks, dictionary, length);
   3914 	z->state->mode = BLOCKS;
   3915 	return (Z_OK);
   3916 }
   3917 
   3918 /*
   3919  * This subroutine adds the data at next_in/avail_in to the output history
   3920  * without performing any output.  The output buffer must be "caught up";
   3921  * i.e. no pending output (hence s->read equals s->write), and the state must
   3922  * be BLOCKS (i.e. we should be willing to see the start of a series of
   3923  * BLOCKS).  On exit, the output will also be caught up, and the checksum
   3924  * will have been updated if need be.
   3925  *
   3926  * Added for PPP.
   3927  */
   3928 
   3929 int
   3930 inflateIncomp(z)
   3931 z_stream *z;
   3932 {
   3933 	if (z->state->mode != BLOCKS)
   3934 		return (Z_DATA_ERROR);
   3935 	return (inflate_addhistory(z->state->blocks, z));
   3936 }
   3937 
   3938 
   3939 int
   3940 inflateSync(z)
   3941 z_streamp z;
   3942 {
   3943 	uInt n;	/* number of bytes to look at */
   3944 	Bytef *p;	/* pointer to bytes */
   3945 	uInt m;	/* number of marker bytes found in a row */
   3946 	uLong r, w;	/* temporaries to save total_in and total_out */
   3947 
   3948 	/* set up */
   3949 	if (z == Z_NULL || z->state == Z_NULL)
   3950 		return (Z_STREAM_ERROR);
   3951 	if (z->state->mode != BAD)
   3952 	{
   3953 		z->state->mode = BAD;
   3954 		z->state->sub.marker = 0;
   3955 	}
   3956 	if ((n = z->avail_in) == 0)
   3957 		return (Z_BUF_ERROR);
   3958 	p = z->next_in;
   3959 	m = z->state->sub.marker;
   3960 
   3961 	/* search */
   3962 	while (n && m < 4)
   3963 	{
   3964 		static const Byte mark[4] = { 0, 0, 0xff, 0xff };
   3965 		if (*p == mark[m])
   3966 			m++;
   3967 		else if (*p)
   3968 			m = 0;
   3969 		else
   3970 			/*
   3971 			 * This statement maps 2->2 and 3->1 because a
   3972 			 * mismatch with input byte 0x00 on the first
   3973 			 * 0xFF in the pattern means that we still
   3974 			 * have two contiguous zeros matched (thus
   3975 			 * offset 2 is kept), but a mismatch on the
   3976 			 * second 0xFF means that only one 0x00 byte
   3977 			 * has been matched.  (Boyer-Moore like
   3978 			 * search.)
   3979 			 */
   3980 			m = 4 - m;
   3981 		p++, n--;
   3982 	}
   3983 
   3984 	/* restore */
   3985 	z->total_in += p - z->next_in;
   3986 	z->next_in = p;
   3987 	z->avail_in = n;
   3988 	z->state->sub.marker = m;
   3989 
   3990 	/* return no joy or set up to restart on a new block */
   3991 	if (m != 4)
   3992 		return (Z_DATA_ERROR);
   3993 	r = z->total_in;  w = z->total_out;
   3994 	(void) inflateReset(z);
   3995 	z->total_in = r;  z->total_out = w;
   3996 	z->state->mode = BLOCKS;
   3997 	return (Z_OK);
   3998 }
   3999 
   4000 /*
   4001  * Returns true if inflate is currently at the end of a block
   4002  * generated by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by
   4003  * one PPP implementation to provide an additional safety check. PPP
   4004  * uses Z_SYNC_FLUSH but removes the length bytes of the resulting
   4005  * empty stored block. When decompressing, PPP checks that at the end
   4006  * of input packet, inflate is waiting for these length bytes.
   4007  */
   4008 int
   4009 inflateSyncPoint(z)
   4010 z_streamp z;
   4011 {
   4012 	if (z == Z_NULL || z->state == Z_NULL || z->state->blocks == Z_NULL)
   4013 		return (Z_STREAM_ERROR);
   4014 	return (inflate_blocks_sync_point(z->state->blocks));
   4015 }
   4016 
   4017 #undef NEEDBYTE
   4018 #undef NEXTBYTE
   4019 /* --- inflate.c */
   4020 
   4021 /* +++ infblock.c */
   4022 /*
   4023  * infblock.c -- interpret and process block types to last block
   4024  * Copyright (C) 1995-1998 Mark Adler
   4025  * For conditions of distribution and use, see copyright notice in zlib.h
   4026  */
   4027 
   4028 /* #include "zutil.h" */
   4029 /* #include "infblock.h" */
   4030 
   4031 /* +++ inftrees.h */
   4032 /*
   4033  * inftrees.h -- header to use inftrees.c
   4034  * Copyright (C) 1995-1998 Mark Adler
   4035  * For conditions of distribution and use, see copyright notice in zlib.h
   4036  */
   4037 
   4038 /*
   4039  * WARNING: this file should *not* be used by applications. It is part
   4040  * of the implementation of the compression library and is subject to
   4041  * change. Applications should only use zlib.h.
   4042  */
   4043 
   4044 /*
   4045  * Huffman code lookup table entry--this entry is four bytes for
   4046  * machines that have 16-bit pointers (e.g. PC's in the small or
   4047  * medium model).
   4048  */
   4049 
   4050 typedef struct inflate_huft_s FAR inflate_huft;
   4051 
   4052 struct inflate_huft_s {
   4053 	union {
   4054 		struct {
   4055 			Byte Exop;	/* number of extra bits or operation */
   4056 			/* number of bits in this code or subcode */
   4057 			Byte Bits;
   4058 		} what;
   4059 		Bytef *pad;	/* pad structure to a power of 2 (4 bytes for */
   4060 	} word;	/*  16-bit, 8 bytes for 32-bit machines) */
   4061 	/* literal, length base, distance base, or table offset */
   4062 	uInt base;
   4063 };
   4064 
   4065 /*
   4066  * Maximum size of dynamic tree.  The maximum found in a long but non-
   4067  * exhaustive search was 1004 huft structures (850 for length/literals
   4068  * and 154 for distances, the latter actually the result of an
   4069  * exhaustive search).  The actual maximum is not known, but the value
   4070  * below is more than safe.
   4071  */
   4072 #define	MANY 1440
   4073 
   4074 extern int inflate_trees_bits OF((
   4075     uIntf *,			/* 19 code lengths */
   4076     uIntf *,			/* bits tree desired/actual depth */
   4077     inflate_huft * FAR *,	/* bits tree result */
   4078     inflate_huft *,		/* space for trees */
   4079     z_streamp));	/* for zalloc, zfree functions */
   4080 
   4081 extern int inflate_trees_dynamic OF((
   4082     uInt,	/* number of literal/length codes */
   4083     uInt,	/* number of distance codes */
   4084     uIntf *,	/* that many (total) code lengths */
   4085     uIntf *,	/* literal desired/actual bit depth */
   4086     uIntf *,	/* distance desired/actual bit depth */
   4087     inflate_huft * FAR *,	/* literal/length tree result */
   4088     inflate_huft * FAR *,	/* distance tree result */
   4089     inflate_huft *,		/* space for trees */
   4090     z_streamp));	/* for zalloc, zfree functions */
   4091 
   4092 extern int inflate_trees_fixed OF((
   4093     uIntf *,	/* literal desired/actual bit depth */
   4094     uIntf *,	/* distance desired/actual bit depth */
   4095     const inflate_huft * FAR *,	/* literal/length tree result */
   4096     const inflate_huft * FAR *,	/* distance tree result */
   4097     z_streamp));
   4098 
   4099 /* --- inftrees.h */
   4100 
   4101 /* +++ infcodes.h */
   4102 /*
   4103  * infcodes.h -- header to use infcodes.c
   4104  * Copyright (C) 1995-1998 Mark Adler
   4105  * For conditions of distribution and use, see copyright notice in zlib.h
   4106  */
   4107 
   4108 /*
   4109  * WARNING: this file should *not* be used by applications. It is part
   4110  * of the implementation of the compression library and is subject to
   4111  * change. Applications should only use zlib.h.
   4112  */
   4113 
   4114 struct inflate_codes_state;
   4115 typedef struct inflate_codes_state FAR inflate_codes_statef;
   4116 
   4117 extern inflate_codes_statef *inflate_codes_new OF((
   4118     uInt, uInt,
   4119     const inflate_huft *, const inflate_huft *,
   4120     z_streamp));
   4121 
   4122 extern int inflate_codes OF((
   4123     inflate_blocks_statef *,
   4124     z_streamp,
   4125     int));
   4126 
   4127 extern void inflate_codes_free OF((
   4128     inflate_codes_statef *,
   4129     z_streamp));
   4130 
   4131 /* --- infcodes.h */
   4132 
   4133 /* +++ infutil.h */
   4134 /*
   4135  * infutil.h -- types and macros common to blocks and codes
   4136  * Copyright (C) 1995-1998 Mark Adler
   4137  * For conditions of distribution and use, see copyright notice in zlib.h
   4138  */
   4139 
   4140 /*
   4141  * WARNING: this file should *not* be used by applications. It is part
   4142  * of the implementation of the compression library and is subject to
   4143  * change. Applications should only use zlib.h.
   4144  */
   4145 
   4146 #ifndef _INFUTIL_H
   4147 #define	_INFUTIL_H
   4148 
   4149 typedef enum {
   4150 	TYPE,	/* get type bits (3, including end bit) */
   4151 	LENS,	/* get lengths for stored */
   4152 	STORED,	/* processing stored block */
   4153 	TABLE,	/* get table lengths */
   4154 	BTREE,	/* get bit lengths tree for a dynamic block */
   4155 	DTREE,	/* get length, distance trees for a dynamic block */
   4156 	CODES,	/* processing fixed or dynamic block */
   4157 	DRY,	/* output remaining window bytes */
   4158 	DONEB,	/* finished last block, done */
   4159 	BADB}	/* got a data error--stuck here */
   4160 inflate_block_mode;
   4161 
   4162 /* inflate blocks semi-private state */
   4163 struct inflate_blocks_state {
   4164 
   4165 	/* mode */
   4166 	inflate_block_mode  mode;	/* current inflate_block mode */
   4167 
   4168 	/* mode dependent information */
   4169 	union {
   4170 		uInt left;	/* if STORED, bytes left to copy */
   4171 		struct {
   4172 			uInt table;	/* table lengths (14 bits) */
   4173 			uInt index;	/* index into blens (or border) */
   4174 			uIntf *blens;	/* bit lengths of codes */
   4175 			uInt bb;	/* bit length tree depth */
   4176 			inflate_huft *tb;	/* bit length decoding tree */
   4177 		} trees;	/* if DTREE, decoding info for trees */
   4178 		struct {
   4179 			inflate_codes_statef *codes;
   4180 		} decode;	/* if CODES, current state */
   4181 	} sub;	/* submode */
   4182 	uInt last;	/* true if this block is the last block */
   4183 
   4184 	/* mode independent information */
   4185 	uInt bitk;	/* bits in bit buffer */
   4186 	uLong bitb;	/* bit buffer */
   4187 	inflate_huft *hufts;  /* single malloc for tree space */
   4188 	Bytef *window;	/* sliding window */
   4189 	Bytef *end;	/* one byte after sliding window */
   4190 	Bytef *read;	/* window read pointer */
   4191 	Bytef *write;	/* window write pointer */
   4192 	check_func checkfn;	/* check function */
   4193 	uLong check;	/* check on output */
   4194 
   4195 };
   4196 
   4197 
   4198 /* defines for inflate input/output */
   4199 /*   update pointers and return */
   4200 #define	UPDBITS {s->bitb = b; s->bitk = k; }
   4201 #define	UPDIN {z->avail_in = n; z->total_in += p-z->next_in; z->next_in = p; }
   4202 #define	UPDOUT {s->write = q; }
   4203 #define	UPDATE {UPDBITS UPDIN UPDOUT}
   4204 #define	LEAVE {UPDATE return (inflate_flush(s, z, r)); }
   4205 /*   get bytes and bits */
   4206 #define	LOADIN {p = z->next_in; n = z->avail_in; b = s->bitb; k = s->bitk; }
   4207 #define	NEEDBYTE { if (n) r = Z_OK; else LEAVE }
   4208 #define	NEXTBYTE (n--, *p++)
   4209 #define	NEEDBITS(j) { while (k < (j)) { NEEDBYTE; b |= ((uLong)NEXTBYTE)<<k; \
   4210 	k += 8; }}
   4211 #define	DUMPBITS(j) {b >>= (j); k -= (j); }
   4212 /*   output bytes */
   4213 #define	WAVAIL (uInt)(q < s->read ? s->read-q-1 : s->end-q)
   4214 #define	LOADOUT {q = s->write; m = (uInt)WAVAIL; }
   4215 #define	WWRAP {if (q == s->end && s->read != s->window) {q = s->window; \
   4216 	m = (uInt)WAVAIL; }}
   4217 #define	FLUSH {UPDOUT r = inflate_flush(s, z, r); LOADOUT}
   4218 #define	NEEDOUT {if (m == 0) {WWRAP if (m == 0) { FLUSH WWRAP \
   4219 	if (m == 0) LEAVE }} r = Z_OK; }
   4220 #define	OUTBYTE(a) {*q++ = (Byte)(a); m--; }
   4221 /*   load local pointers */
   4222 #define	LOAD {LOADIN LOADOUT}
   4223 
   4224 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
   4225 extern uInt inflate_mask[17];
   4226 
   4227 /* copy as much as possible from the sliding window to the output area */
   4228 extern int inflate_flush OF((
   4229     inflate_blocks_statef *,
   4230     z_streamp,
   4231     int));
   4232 
   4233 #ifndef NO_DUMMY_DECL
   4234 struct internal_state {int dummy; };	/* for buggy compilers */
   4235 #endif
   4236 
   4237 #endif
   4238 /* --- infutil.h */
   4239 
   4240 #ifndef NO_DUMMY_DECL
   4241 struct inflate_codes_state {int dummy; };	/* for buggy compilers */
   4242 #endif
   4243 
   4244 /* Table for deflate from PKZIP's appnote.txt. */
   4245 local const uInt border[] = { /* Order of the bit length code lengths */
   4246 	16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
   4247 
   4248 /*
   4249  * Notes beyond the 1.93a appnote.txt:
   4250  *
   4251  *   1. Distance pointers never point before the beginning of the output
   4252  *      stream.
   4253  *   2. Distance pointers can point back across blocks, up to 32k away.
   4254  *   3. There is an implied maximum of 7 bits for the bit length table and
   4255  *      15 bits for the actual data.
   4256  *   4. If only one code exists, then it is encoded using one bit.  (Zero
   4257  *      would be more efficient, but perhaps a little confusing.)  If two
   4258  *      codes exist, they are coded using one bit each (0 and 1).
   4259  *   5. There is no way of sending zero distance codes--a dummy must be
   4260  *      sent if there are none.  (History: a pre 2.0 version of PKZIP would
   4261  *      store blocks with no distance codes, but this was discovered to be
   4262  *      too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow
   4263  *      zero distance codes, which is sent as one code of zero bits in
   4264  *      length.
   4265  *   6. There are up to 286 literal/length codes.  Code 256 represents the
   4266  *      end-of-block.  Note however that the static length tree defines
   4267  *      288 codes just to fill out the Huffman codes.  Codes 286 and 287
   4268  *      cannot be used though, since there is no length base or extra bits
   4269  *      defined for them.  Similarily, there are up to 30 distance codes.
   4270  *      However, static trees define 32 codes (all 5 bits) to fill out the
   4271  *      Huffman codes, but the last two had better not show up in the data.
   4272  *   7. Unzip can check dynamic Huffman blocks for complete code sets.
   4273  *      The exception is that a single code would not be complete (see #4).
   4274  *   8. The five bits following the block type is really the number of
   4275  *      literal codes sent minus 257.
   4276  *   9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
   4277  *      (1+6+6).  Therefore, to output three times the length, you output
   4278  *      three codes (1+1+1), whereas to output four times the same length,
   4279  *      you only need two codes (1+3).  Hmm.
   4280  *  10. In the tree reconstruction algorithm, Code = Code + Increment
   4281  *      only if BitLength(i) is not zero.  (Pretty obvious.)
   4282  *  11. Correction: 4 Bits: #of Bit Length codes - 4     (4 - 19)
   4283  *  12. Note: length code 284 can represent 227-258, but length code 285
   4284  *      really is 258.  The last length deserves its own, short code
   4285  *      since it gets used a lot in very redundant files.  The length
   4286  *      258 is special since 258 - 3 (the min match length) is 255.
   4287  *  13. The literal/length and distance code bit lengths are read as a
   4288  *      single stream of lengths.  It is possible (and advantageous) for
   4289  *      a repeat code (16, 17, or 18) to go across the boundary between
   4290  *      the two sets of lengths.
   4291  */
   4292 
   4293 
   4294 void
   4295 inflate_blocks_reset(s, z, c)
   4296 inflate_blocks_statef *s;
   4297 z_streamp z;
   4298 uLongf *c;
   4299 {
   4300 	if (c != Z_NULL)
   4301 		*c = s->check;
   4302 	if ((s->mode == BTREE || s->mode == DTREE) &&
   4303 	    s->sub.trees.blens != Z_NULL) {
   4304 		ZFREE(z, s->sub.trees.blens);
   4305 		s->sub.trees.blens = Z_NULL;
   4306 	}
   4307 	if (s->mode == CODES && s->sub.decode.codes != Z_NULL) {
   4308 		(void) inflate_codes_free(s->sub.decode.codes, z);
   4309 		s->sub.decode.codes = Z_NULL;
   4310 	}
   4311 	s->mode = TYPE;
   4312 	s->bitk = 0;
   4313 	s->bitb = 0;
   4314 	s->read = s->write = s->window;
   4315 	if (s->checkfn != Z_NULL)
   4316 		z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
   4317 	Trace((stderr, "inflate:   blocks reset\n"));
   4318 }
   4319 
   4320 inflate_blocks_statef *
   4321 inflate_blocks_new(z, c, w)
   4322 z_streamp z;
   4323 check_func c;
   4324 uInt w;
   4325 {
   4326 	inflate_blocks_statef *s;
   4327 
   4328 	if ((s = (inflate_blocks_statef *)ZALLOC
   4329 	    (z, 1, sizeof (struct inflate_blocks_state))) == Z_NULL)
   4330 		return (s);
   4331 	s->hufts = (inflate_huft *)ZALLOC(z, MANY, sizeof (inflate_huft));
   4332 	if (s->hufts == Z_NULL) {
   4333 		ZFREE(z, s);
   4334 		return (Z_NULL);
   4335 	}
   4336 	if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
   4337 	{
   4338 		ZFREE(z, s->hufts);
   4339 		ZFREE(z, s);
   4340 		return (Z_NULL);
   4341 	}
   4342 	s->end = s->window + w;
   4343 	s->checkfn = c;
   4344 	s->mode = TYPE;
   4345 	Trace((stderr, "inflate:   blocks allocated\n"));
   4346 	inflate_blocks_reset(s, z, Z_NULL);
   4347 	return (s);
   4348 }
   4349 
   4350 
   4351 int
   4352 inflate_blocks(s, z, r)
   4353 inflate_blocks_statef *s;
   4354 z_streamp z;
   4355 int r;
   4356 {
   4357 	uInt t;	/* temporary storage */
   4358 	uLong b;	/* bit buffer */
   4359 	uInt k;	/* bits in bit buffer */
   4360 	Bytef *p;	/* input data pointer */
   4361 	uInt n;	/* bytes available there */
   4362 	Bytef *q;	/* output window write pointer */
   4363 	uInt m;	/* bytes to end of window or read pointer */
   4364 
   4365 	/* copy input/output information to locals (UPDATE macro restores) */
   4366 	LOAD;
   4367 
   4368 	/* process input based on current state */
   4369 	/* CONSTCOND */
   4370 	while (1)
   4371 		switch (s->mode)
   4372 	{
   4373 	case TYPE:
   4374 		NEEDBITS(3);
   4375 		t = (uInt)b & 7;
   4376 		s->last = t & 1;
   4377 		switch (t >> 1)
   4378 		{
   4379 		case 0:			/* stored */
   4380 			Trace((stderr, "inflate:     stored block%s\n",
   4381 			    s->last ? " (last)" : ""));
   4382 			DUMPBITS(3);
   4383 			t = k & 7;	/* go to byte boundary */
   4384 			DUMPBITS(t);
   4385 			s->mode = LENS;	/* get length of stored block */
   4386 			break;
   4387 		case 1:			/* fixed */
   4388 			Trace((stderr, "inflate:     fixed codes block%s\n",
   4389 			    s->last ? " (last)" : ""));
   4390 			{
   4391 				uInt bl, bd;
   4392 				const inflate_huft *tl, *td;
   4393 
   4394 				(void) inflate_trees_fixed(&bl, &bd, &tl, &td,
   4395 				    z);
   4396 				s->sub.decode.codes = inflate_codes_new(bl,
   4397 				    bd, tl, td, z);
   4398 				if (s->sub.decode.codes == Z_NULL)
   4399 				{
   4400 					r = Z_MEM_ERROR;
   4401 					LEAVE
   4402 				}
   4403 			}
   4404 			DUMPBITS(3);
   4405 			s->mode = CODES;
   4406 			break;
   4407 		case 2:			/* dynamic */
   4408 			Trace((stderr, "inflate:     dynamic codes block%s\n",
   4409 			    s->last ? " (last)" : ""));
   4410 			DUMPBITS(3);
   4411 			s->mode = TABLE;
   4412 			break;
   4413 		case 3:			/* illegal */
   4414 			DUMPBITS(3);
   4415 			s->mode = BADB;
   4416 			z->msg = "invalid block type";
   4417 			r = Z_DATA_ERROR;
   4418 			LEAVE
   4419 		}
   4420 		break;
   4421 	case LENS:
   4422 		NEEDBITS(32);
   4423 		if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
   4424 		{
   4425 			s->mode = BADB;
   4426 			z->msg = "invalid stored block lengths";
   4427 			r = Z_DATA_ERROR;
   4428 			LEAVE
   4429 		}
   4430 		s->sub.left = (uInt)b & 0xffff;
   4431 		b = k = 0;	/* dump bits */
   4432 		Tracev((stderr, "inflate:       stored length %u\n",
   4433 		    s->sub.left));
   4434 		s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
   4435 		break;
   4436 	case STORED:
   4437 		if (n == 0)
   4438 			LEAVE
   4439 		NEEDOUT;
   4440 		t = s->sub.left;
   4441 		if (t > n) t = n;
   4442 		if (t > m) t = m;
   4443 		zmemcpy(q, p, t);
   4444 		p += t;  n -= t;
   4445 		q += t;  m -= t;
   4446 		if ((s->sub.left -= t) != 0)
   4447 			break;
   4448 		Tracev((stderr,
   4449 		    "inflate:       stored end, %lu total out\n",
   4450 		    z->total_out + (q >= s->read ? q - s->read :
   4451 			(s->end - s->read) + (q - s->window))));
   4452 		s->mode = s->last ? DRY : TYPE;
   4453 		break;
   4454 	case TABLE:
   4455 		NEEDBITS(14);
   4456 		s->sub.trees.table = t = (uInt)b & 0x3fff;
   4457 #ifndef PKZIP_BUG_WORKAROUND
   4458 		if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
   4459 		{
   4460 			s->mode = BADB;
   4461 			z->msg =
   4462 			    (char *)"too many length or distance symbols";
   4463 			r = Z_DATA_ERROR;
   4464 			LEAVE
   4465 		}
   4466 #endif
   4467 		t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
   4468 		/* if (t < 19) t = 19; */
   4469 		if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t,
   4470 		    sizeof (uInt))) == Z_NULL)
   4471 		{
   4472 			r = Z_MEM_ERROR;
   4473 			LEAVE
   4474 		}
   4475 		DUMPBITS(14);
   4476 		s->sub.trees.index = 0;
   4477 		Tracev((stderr, "inflate:       table sizes ok\n"));
   4478 		s->mode = BTREE;
   4479 		/* FALLTHRU */
   4480 	case BTREE:
   4481 		while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
   4482 		{
   4483 			NEEDBITS(3);
   4484 			s->sub.trees.blens[border[s->sub.trees.index++]] =
   4485 			    (uInt)b & 7;
   4486 			DUMPBITS(3);
   4487 		}
   4488 		while (s->sub.trees.index < 19)
   4489 			s->sub.trees.blens[border[s->sub.trees.index++]] =
   4490 			    0;
   4491 		s->sub.trees.bb = 7;
   4492 		t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
   4493 		    &s->sub.trees.tb, s->hufts, z);
   4494 		if (t != Z_OK)
   4495 		{
   4496 			ZFREE(z, s->sub.trees.blens);
   4497 			s->sub.trees.blens = Z_NULL;
   4498 			r = t;
   4499 			if (r == Z_DATA_ERROR)
   4500 				s->mode = BADB;
   4501 			LEAVE
   4502 		}
   4503 		s->sub.trees.index = 0;
   4504 		Tracev((stderr, "inflate:       bits tree ok\n"));
   4505 		s->mode = DTREE;
   4506 		/* FALLTHRU */
   4507 	case DTREE:
   4508 		while (t = s->sub.trees.table,
   4509 		    s->sub.trees.index < 258 + (t & 0x1f) +
   4510 		    ((t >> 5) & 0x1f))
   4511 		{
   4512 			inflate_huft *h;
   4513 			uInt i, j, c;
   4514 
   4515 			t = s->sub.trees.bb;
   4516 			NEEDBITS(t);
   4517 			h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
   4518 			t = h->word.what.Bits;
   4519 			c = h->base;
   4520 			if (c < 16)
   4521 			{
   4522 				DUMPBITS(t);
   4523 				s->sub.trees.blens[s->sub.trees.index++] =
   4524 				    c;
   4525 			} else { /* c == 16..18 */
   4526 				i = c == 18 ? 7 : c - 14;
   4527 				j = c == 18 ? 11 : 3;
   4528 				NEEDBITS(t + i);
   4529 				DUMPBITS(t);
   4530 				j += (uInt)b & inflate_mask[i];
   4531 				DUMPBITS(i);
   4532 				i = s->sub.trees.index;
   4533 				t = s->sub.trees.table;
   4534 				if (i + j > 258 + (t & 0x1f) +
   4535 				    ((t >> 5) & 0x1f) ||
   4536 				    (c == 16 && i < 1))
   4537 				{
   4538 					ZFREE(z, s->sub.trees.blens);
   4539 					s->sub.trees.blens = Z_NULL;
   4540 					s->mode = BADB;
   4541 					z->msg = "invalid bit length repeat";
   4542 					r = Z_DATA_ERROR;
   4543 					LEAVE
   4544 				}
   4545 				c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
   4546 				do {
   4547 					s->sub.trees.blens[i++] = c;
   4548 				} while (--j);
   4549 				s->sub.trees.index = i;
   4550 			}
   4551 		}
   4552 		s->sub.trees.tb = Z_NULL;
   4553 		{
   4554 			uInt bl, bd;
   4555 			inflate_huft *tl, *td;
   4556 			inflate_codes_statef *c;
   4557 
   4558 				/* must be <= 9 for lookahead assumptions */
   4559 			bl = 9;
   4560 				/* must be <= 9 for lookahead assumptions */
   4561 			bd = 6;
   4562 			t = s->sub.trees.table;
   4563 			t = inflate_trees_dynamic(257 + (t & 0x1f),
   4564 			    1 + ((t >> 5) & 0x1f),
   4565 			    s->sub.trees.blens, &bl, &bd, &tl, &td,
   4566 			    s->hufts, z);
   4567 			ZFREE(z, s->sub.trees.blens);
   4568 			s->sub.trees.blens = Z_NULL;
   4569 			if (t != Z_OK)
   4570 			{
   4571 				if (t == (uInt)Z_DATA_ERROR)
   4572 					s->mode = BADB;
   4573 				r = t;
   4574 				LEAVE
   4575 			}
   4576 			Tracev((stderr, "inflate:       trees ok\n"));
   4577 			if ((c = inflate_codes_new(bl, bd, tl, td, z)) ==
   4578 			    Z_NULL)
   4579 			{
   4580 				r = Z_MEM_ERROR;
   4581 				LEAVE
   4582 			}
   4583 			s->sub.decode.codes = c;
   4584 		}
   4585 		s->mode = CODES;
   4586 		/* FALLTHRU */
   4587 	case CODES:
   4588 		UPDATE;
   4589 		if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
   4590 			return (inflate_flush(s, z, r));
   4591 		r = Z_OK;
   4592 		(void) inflate_codes_free(s->sub.decode.codes, z);
   4593 		LOAD;
   4594 		Tracev((stderr, "inflate:       codes end, %lu total out\n",
   4595 		    z->total_out + (q >= s->read ? q - s->read :
   4596 			(s->end - s->read) + (q - s->window))));
   4597 		if (!s->last)
   4598 		{
   4599 			s->mode = TYPE;
   4600 			break;
   4601 		}
   4602 		s->mode = DRY;
   4603 		/* FALLTHRU */
   4604 	case DRY:
   4605 		FLUSH;
   4606 		if (s->read != s->write)
   4607 			LEAVE
   4608 		s->mode = DONEB;
   4609 		/* FALLTHRU */
   4610 	case DONEB:
   4611 		r = Z_STREAM_END;
   4612 		LEAVE
   4613 	case BADB:
   4614 		r = Z_DATA_ERROR;
   4615 		LEAVE
   4616 	default:
   4617 		r = Z_STREAM_ERROR;
   4618 		LEAVE
   4619 	}
   4620 	/* NOTREACHED */
   4621 	/* otherwise lint complains */
   4622 }
   4623 
   4624 
   4625 int
   4626 inflate_blocks_free(s, z)
   4627 inflate_blocks_statef *s;
   4628 z_streamp z;
   4629 {
   4630 	inflate_blocks_reset(s, z, Z_NULL);
   4631 	ZFREE(z, s->window);
   4632 	s->window = Z_NULL;
   4633 	ZFREE(z, s->hufts);
   4634 	s->hufts = Z_NULL;
   4635 	ZFREE(z, s);
   4636 	Trace((stderr, "inflate:   blocks freed\n"));
   4637 	return (Z_OK);
   4638 }
   4639 
   4640 
   4641 void
   4642 inflate_set_dictionary(s, d, n)
   4643 inflate_blocks_statef *s;
   4644 const Bytef *d;
   4645 uInt  n;
   4646 {
   4647 	Assert(s->window + n <= s->end, "set dict");
   4648 	zmemcpy((charf *)s->window, d, n);
   4649 	s->read = s->write = s->window + n;
   4650 }
   4651 
   4652 /*
   4653  * Returns true if inflate is currently at the end of a block
   4654  * generated by Z_SYNC_FLUSH or Z_FULL_FLUSH.
   4655  * IN assertion: s != Z_NULL
   4656  */
   4657 int
   4658 inflate_blocks_sync_point(s)
   4659 inflate_blocks_statef *s;
   4660 {
   4661 	return (s->mode == LENS);
   4662 }
   4663 
   4664 /*
   4665  * This subroutine adds the data at next_in/avail_in to the output history
   4666  * without performing any output.  The output buffer must be "caught up";
   4667  * i.e. no pending output (hence s->read equals s->write), and the state must
   4668  * be BLOCKS (i.e. we should be willing to see the start of a series of
   4669  * BLOCKS).  On exit, the output will also be caught up, and the checksum
   4670  * will have been updated if need be.
   4671  */
   4672 int
   4673 inflate_addhistory(s, z)
   4674 inflate_blocks_statef *s;
   4675 z_stream *z;
   4676 {
   4677 	uLong b;	/* bit buffer */  /* NOT USED HERE */
   4678 	uInt k;	/* bits in bit buffer */ /* NOT USED HERE */
   4679 	uInt t;	/* temporary storage */
   4680 	Bytef *p;	/* input data pointer */
   4681 	uInt n;	/* bytes available there */
   4682 	Bytef *q;	/* output window write pointer */
   4683 	uInt m;	/* bytes to end of window or read pointer */
   4684 
   4685 	if (s->read != s->write)
   4686 		return (Z_STREAM_ERROR);
   4687 	if (s->mode != TYPE)
   4688 		return (Z_DATA_ERROR);
   4689 
   4690 	/* we're ready to rock */
   4691 	LOAD;
   4692 	/*
   4693 	 * while there is input ready, copy to output buffer, moving
   4694 	 * pointers as needed.
   4695 	 */
   4696 	while (n) {
   4697 		t = n;	/* how many to do */
   4698 		/* is there room until end of buffer? */
   4699 		if (t > m) t = m;
   4700 		/* update check information */
   4701 		if (s->checkfn != Z_NULL)
   4702 			s->check = (*s->checkfn)(s->check, q, t);
   4703 		zmemcpy(q, p, t);
   4704 		q += t;
   4705 		p += t;
   4706 		n -= t;
   4707 		z->total_out += t;
   4708 		s->read = q;	/* drag read pointer forward */
   4709 /* WWRAP */	/* expand WWRAP macro by hand to handle s->read */
   4710 		if (q == s->end) {
   4711 			s->read = q = s->window;
   4712 			m = WAVAIL;
   4713 		}
   4714 	}
   4715 	UPDATE;
   4716 	return (Z_OK);
   4717 }
   4718 
   4719 
   4720 /*
   4721  * At the end of a Deflate-compressed PPP packet, we expect to have seen
   4722  * a `stored' block type value but not the (zero) length bytes.
   4723  */
   4724 int
   4725 inflate_packet_flush(s)
   4726     inflate_blocks_statef *s;
   4727 {
   4728 	if (s->mode != LENS)
   4729 		return (Z_DATA_ERROR);
   4730 	s->mode = TYPE;
   4731 	return (Z_OK);
   4732 }
   4733 /* --- infblock.c */
   4734 
   4735 /* +++ inftrees.c */
   4736 /*
   4737  * inftrees.c -- generate Huffman trees for efficient decoding
   4738  * Copyright (C) 1995-1998 Mark Adler
   4739  * For conditions of distribution and use, see copyright notice in zlib.h
   4740  */
   4741 
   4742 /* #include "zutil.h" */
   4743 /* #include "inftrees.h" */
   4744 
   4745 const char inflate_copyright[] =
   4746 " inflate 1.1.3 Copyright 1995-1998 Mark Adler ";
   4747 /*
   4748  * If you use the zlib library in a product, an acknowledgment is
   4749  * welcome in the documentation of your product. If for some reason
   4750  * you cannot include such an acknowledgment, I would appreciate that
   4751  * you keep this copyright string in the executable of your product.
   4752  */
   4753 
   4754 #ifndef NO_DUMMY_DECL
   4755 struct internal_state  {int dummy; };	/* for buggy compilers */
   4756 #endif
   4757 
   4758 /* simplify the use of the inflate_huft type with some defines */
   4759 #define	exop word.what.Exop
   4760 #define	bits word.what.Bits
   4761 
   4762 
   4763 local int huft_build OF((
   4764 	uIntf *,	/* code lengths in bits */
   4765 	uInt,		/* number of codes */
   4766 	uInt,		/* number of "simple" codes */
   4767 	const uIntf *,	/* list of base values for non-simple codes */
   4768 	const uIntf *,	/* list of extra bits for non-simple codes */
   4769 	inflate_huft * FAR*, /* result: starting table */
   4770 	uIntf *,	/* maximum lookup bits (returns actual) */
   4771 	inflate_huft *hp,	/* space for trees */
   4772 	uInt *hn,	/* hufts used in space */
   4773 	uIntf *v));	/* working area: values in order of bit length */
   4774 
   4775 /* Tables for deflate from PKZIP's appnote.txt. */
   4776 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
   4777 	3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
   4778 	35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
   4779 	/* see note #13 above about 258 */
   4780 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
   4781 	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
   4782 	3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112};
   4783 	/* 112==invalid */
   4784 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
   4785 	1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
   4786 	257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
   4787 	8193, 12289, 16385, 24577};
   4788 local const uInt cpdext[30] = { /* Extra bits for distance codes */
   4789 	0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
   4790 	7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
   4791 	12, 12, 13, 13};
   4792 
   4793 /*
   4794  * Huffman code decoding is performed using a multi-level table
   4795  * lookup.  The fastest way to decode is to simply build a lookup
   4796  * table whose size is determined by the longest code.  However, the
   4797  * time it takes to build this table can also be a factor if the data
   4798  * being decoded is not very long.  The most common codes are
   4799  * necessarily the shortest codes, so those codes dominate the
   4800  * decoding time, and hence the speed.  The idea is you can have a
   4801  * shorter table that decodes the shorter, more probable codes, and
   4802  * then point to subsidiary tables for the longer codes.  The time it
   4803  * costs to decode the longer codes is then traded against the time it
   4804  * takes to make longer tables.
   4805  *
   4806  * This results of this trade are in the variables lbits and dbits
   4807  * below.  lbits is the number of bits the first level table for
   4808  * literal/ length codes can decode in one step, and dbits is the same
   4809  * thing for the distance codes.  Subsequent tables are also less than
   4810  * or equal to those sizes.  These values may be adjusted either when
   4811  * all of the codes are shorter than that, in which case the longest
   4812  * code length in bits is used, or when the shortest code is *longer*
   4813  * than the requested table size, in which case the length of the
   4814  * shortest code in bits is used.
   4815  *
   4816  * There are two different values for the two tables, since they code
   4817  * a different number of possibilities each.  The literal/length table
   4818  * codes 286 possible values, or in a flat code, a little over eight
   4819  * bits.  The distance table codes 30 possible values, or a little
   4820  * less than five bits, flat.  The optimum values for speed end up
   4821  * being about one bit more than those, so lbits is 8+1 and dbits is
   4822  * 5+1.  The optimum values may differ though from machine to machine,
   4823  * and possibly even between compilers.  Your mileage may vary.
   4824  */
   4825 
   4826 
   4827 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
   4828 #define	BMAX 15		/* maximum bit length of any code */
   4829 
   4830 
   4831 local int
   4832 huft_build(b, n, s, d, e, t, m, hp, hn, v)
   4833 uIntf *b;	/* code lengths in bits (all assumed <= BMAX) */
   4834 uInt n;	/* number of codes (assumed <= 288) */
   4835 uInt s;	/* number of simple-valued codes (0..s-1) */
   4836 const uIntf *d;	/* list of base values for non-simple codes */
   4837 const uIntf *e;	/* list of extra bits for non-simple codes */
   4838 inflate_huft * FAR *t;	/* result: starting table */
   4839 uIntf *m;	/* maximum lookup bits, returns actual */
   4840 inflate_huft *hp;	/* space for trees */
   4841 uInt *hn;		/* hufts used in space */
   4842 uIntf *v;		/* working area: values in order of bit length */
   4843 /*
   4844  * Given a list of code lengths and a maximum table size, make a set
   4845  * of tables to decode that set of codes.  Return Z_OK on success,
   4846  * Z_BUF_ERROR if the given code set is incomplete (the tables are
   4847  * still built in this case), Z_DATA_ERROR if the input is invalid (an
   4848  * over-subscribed set of lengths), or Z_MEM_ERROR if not enough
   4849  * memory.
   4850  */
   4851 {
   4852 
   4853 	uInt a;	/* counter for codes of length k */
   4854 	uInt c[BMAX+1];	/* bit length count table */
   4855 	uInt f;	/* i repeats in table every f entries */
   4856 	int g;	/* maximum code length */
   4857 	int h;	/* table level */
   4858 	register uInt i;	/* counter, current code */
   4859 	register uInt j;	/* counter */
   4860 	register int k;	/* number of bits in current code */
   4861 	int l;	/* bits per table (returned in m) */
   4862 	register uIntf *p;	/* pointer into c[], b[], or v[] */
   4863 	inflate_huft *q;	/* points to current table */
   4864 	struct inflate_huft_s r; /* table entry for structure assignment */
   4865 	inflate_huft *u[BMAX];	/* table stack */
   4866 	uInt mask;	/* (1 << w) - 1, to avoid cc -O bug on HP */
   4867 	register int w;	/* bits before this table == (l * h) */
   4868 	uInt x[BMAX+1];	/* bit offsets, then code stack */
   4869 	uIntf *xp;	/* pointer into x */
   4870 	int y;	/* number of dummy codes added */
   4871 	uInt z;	/* number of entries in current table */
   4872 
   4873 	(void) inflate_copyright;
   4874 	/* Generate counts for each bit length */
   4875 	p = c;
   4876 #define	C0 *p++ = 0;
   4877 #define	C2 C0 C0 C0 C0
   4878 #define	C4 C2 C2 C2 C2
   4879 	C4	/* clear c[]--assume BMAX+1 is 16 */
   4880 	    p = b;  i = n;
   4881 	do {
   4882 		c[*p++]++;	/* assume all entries <= BMAX */
   4883 	} while (--i);
   4884 	if (c[0] == n)		/* null input--all zero length codes */
   4885 	{
   4886 		*t = (inflate_huft *)Z_NULL;
   4887 		*m = 0;
   4888 		return (Z_OK);
   4889 	}
   4890 
   4891 
   4892 	/* Find minimum and maximum length, bound *m by those */
   4893 	l = *m;
   4894 	for (j = 1; j <= BMAX; j++)
   4895 		if (c[j])
   4896 			break;
   4897 	k = j;	/* minimum code length */
   4898 	if ((uInt)l < j)
   4899 		l = j;
   4900 	for (i = BMAX; i; i--)
   4901 		if (c[i])
   4902 			break;
   4903 	g = i;	/* maximum code length */
   4904 	if ((uInt)l > i)
   4905 		l = i;
   4906 	*m = l;
   4907 
   4908 
   4909 	/* Adjust last length count to fill out codes, if needed */
   4910 	for (y = 1 << j; j < i; j++, y <<= 1)
   4911 		if ((y -= c[j]) < 0)
   4912 			return (Z_DATA_ERROR);
   4913 	if ((y -= c[i]) < 0)
   4914 		return (Z_DATA_ERROR);
   4915 	c[i] += y;
   4916 
   4917 
   4918 	/* Generate starting offsets into the value table for each length */
   4919 	x[1] = j = 0;
   4920 	p = c + 1;  xp = x + 2;
   4921 	while (--i) {		/* note that i == g from above */
   4922 		*xp++ = (j += *p++);
   4923 	}
   4924 
   4925 
   4926 	/* Make a table of values in order of bit lengths */
   4927 	p = b;  i = 0;
   4928 	do {
   4929 		if ((j = *p++) != 0)
   4930 			v[x[j]++] = i;
   4931 	} while (++i < n);
   4932 	n = x[g];	/* set n to length of v */
   4933 
   4934 
   4935 	/* Generate the Huffman codes and for each, make the table entries */
   4936 	x[0] = i = 0;	/* first Huffman code is zero */
   4937 	p = v;	/* grab values in bit order */
   4938 	h = -1;	/* no tables yet--level -1 */
   4939 	w = -l;	/* bits decoded == (l * h) */
   4940 	u[0] = (inflate_huft *)Z_NULL;	/* just to keep compilers happy */
   4941 	q = (inflate_huft *)Z_NULL;	/* ditto */
   4942 	z = 0;	/* ditto */
   4943 
   4944 	/* go through the bit lengths (k already is bits in shortest code) */
   4945 	for (; k <= g; k++) {
   4946 		a = c[k];
   4947 		while (a--) {
   4948 			/*
   4949 			 * here i is the Huffman code of length k bits
   4950 			 * for value *p.  make tables up to required
   4951 			 * level.
   4952 			 */
   4953 			while (k > w + l) {
   4954 				h++;
   4955 				w += l;	/* previous table always l bits */
   4956 
   4957 				/*
   4958 				 * compute minimum size table less
   4959 				 * than or equal to l bits
   4960 				 */
   4961 				z = g - w;
   4962 				/* table size upper limit */
   4963 				z = z > (uInt)l ? l : z;
   4964 				/* try a k-w bit table */
   4965 				if ((f = 1 << (j = k - w)) > a + 1) {
   4966 					/* too few codes for k-w bit table */
   4967 					/* deduct codes from patterns left */
   4968 					f -= a + 1;
   4969 					xp = c + k;
   4970 					if (j < z)
   4971 						/*
   4972 						 * try smaller tables
   4973 						 * up to z bits
   4974 						 */
   4975 						while (++j < z) {
   4976 							/*
   4977 							 * enough
   4978 							 * codes to
   4979 							 * use up j
   4980 							 * bits
   4981 							 */
   4982 							if ((f <<= 1) <= *++xp)
   4983 								break;
   4984 							f -= *xp;
   4985 							/*
   4986 							 * else deduct
   4987 							 * codes from
   4988 							 * patterns
   4989 							 */
   4990 						}
   4991 				}
   4992 				/* table entries for j-bit table */
   4993 				z = 1 << j;
   4994 
   4995 				/* allocate new table */
   4996 				/* (note: doesn't matter for fixed) */
   4997 				/* not enough memory */
   4998 				if (*hn + z > MANY)
   4999 					return (Z_MEM_ERROR);
   5000 				u[h] = q = hp + *hn;
   5001 				*hn += z;
   5002 
   5003 				/* connect to last table, if there is one */
   5004 				if (h) {
   5005 					/* save pattern for backing up */
   5006 					x[h] = i;
   5007 					/* bits to dump before this table */
   5008 					r.bits = (Byte)l;
   5009 					/* bits in this table */
   5010 					r.exop = (Byte)j;
   5011 					j = i >> (w - l);
   5012 					/* offset to this table */
   5013 					r.base = (uInt)(q - u[h-1] - j);
   5014 					/* connect to last table */
   5015 					u[h-1][j] = r;
   5016 				} else
   5017 					/* first table is returned result */
   5018 					*t = q;
   5019 			}
   5020 
   5021 			/* set up table entry in r */
   5022 			r.bits = (Byte)(k - w);
   5023 			if (p >= v + n)
   5024 				/* out of values--invalid code */
   5025 				r.exop = 128 + 64;
   5026 			else if (*p < s)
   5027 			{
   5028 				/* 256 is end-of-block */
   5029 				r.exop = (Byte)(*p < 256 ? 0 : 32 + 64);
   5030 				/* simple code is just the value */
   5031 				r.base = *p++;
   5032 			}
   5033 			else
   5034 			{
   5035 				/* non-simple--look up in lists */
   5036 				r.exop = (Byte)(e[*p - s] + 16 + 64);
   5037 				r.base = d[*p++ - s];
   5038 			}
   5039 
   5040 			/* fill code-like entries with r */
   5041 			f = 1 << (k - w);
   5042 			for (j = i >> w; j < z; j += f)
   5043 				q[j] = r;
   5044 
   5045 			/* backwards increment the k-bit code i */
   5046 			for (j = 1 << (k - 1); i & j; j >>= 1)
   5047 				i ^= j;
   5048 			i ^= j;
   5049 
   5050 			/* backup over finished tables */
   5051 			mask = (1 << w) - 1;	/* needed on HP, cc -O bug */
   5052 			while ((i & mask) != x[h])
   5053 			{
   5054 				h--;	/* don't need to update q */
   5055 				w -= l;
   5056 				mask = (1 << w) - 1;
   5057 			}
   5058 		}
   5059 	}
   5060 
   5061 
   5062 	/* Return Z_BUF_ERROR if we were given an incomplete table */
   5063 	return (y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK);
   5064 }
   5065 
   5066 
   5067 int
   5068 inflate_trees_bits(c, bb, tb, hp, z)
   5069 uIntf *c;	/* 19 code lengths */
   5070 uIntf *bb;	/* bits tree desired/actual depth */
   5071 inflate_huft * FAR *tb;	/* bits tree result */
   5072 inflate_huft *hp;	/* space for trees */
   5073 z_streamp z;	/* for zfree function */
   5074 {
   5075 	int r;
   5076 	uInt hn = 0;		/* hufts used in space */
   5077 	uIntf v[19];		/* work area for huft_build */
   5078 
   5079 	r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb,
   5080 	    hp, &hn, v);
   5081 	if (r == Z_DATA_ERROR)
   5082 		z->msg = "oversubscribed dynamic bit lengths tree";
   5083 	else if (r == Z_BUF_ERROR || *bb == 0)
   5084 	{
   5085 		z->msg = "incomplete dynamic bit lengths tree";
   5086 		r = Z_DATA_ERROR;
   5087 	}
   5088 	return (r);
   5089 }
   5090 
   5091 
   5092 int
   5093 inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, hp, z)
   5094 uInt nl;	/* number of literal/length codes */
   5095 uInt nd;	/* number of distance codes */
   5096 uIntf *c;	/* that many (total) code lengths */
   5097 uIntf *bl;	/* literal desired/actual bit depth */
   5098 uIntf *bd;	/* distance desired/actual bit depth */
   5099 inflate_huft * FAR *tl;	/* literal/length tree result */
   5100 inflate_huft * FAR *td;	/* distance tree result */
   5101 inflate_huft *hp;	/* space for trees */
   5102 z_streamp z;	/* for zfree function */
   5103 {
   5104 	int r;
   5105 	uInt hn = 0;		/* hufts used in space */
   5106 	uIntf v[288];		/* work area for huft_build */
   5107 
   5108 	/* build literal/length tree */
   5109 	r = huft_build(c, nl, 257, cplens, cplext, tl, bl, hp, &hn, v);
   5110 	if (r != Z_OK || *bl == 0)
   5111 	{
   5112 		if (r == Z_DATA_ERROR)
   5113 			z->msg = "oversubscribed literal/length tree";
   5114 		else if (r != Z_MEM_ERROR)
   5115 		{
   5116 			z->msg = "incomplete literal/length tree";
   5117 			r = Z_DATA_ERROR;
   5118 		}
   5119 		return (r);
   5120 	}
   5121 
   5122 	/* build distance tree */
   5123 	r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, hp, &hn, v);
   5124 	if (r != Z_OK || (*bd == 0 && nl > 257))
   5125 	{
   5126 		if (r == Z_DATA_ERROR)
   5127 			z->msg = "oversubscribed distance tree";
   5128 		else if (r == Z_BUF_ERROR) {
   5129 #ifdef PKZIP_BUG_WORKAROUND
   5130 			r = Z_OK;
   5131 #else
   5132 			z->msg = "incomplete distance tree";
   5133 			r = Z_DATA_ERROR;
   5134 		} else if (r != Z_MEM_ERROR) {
   5135 			z->msg = "empty distance tree with lengths";
   5136 			r = Z_DATA_ERROR;
   5137 #endif
   5138 		}
   5139 		return (r);
   5140 	}
   5141 
   5142 /* done */
   5143 	return (Z_OK);
   5144 }
   5145 
   5146 
   5147 /* build fixed tables only once--keep them here */
   5148 /* #define	BUILDFIXED */
   5149 #ifdef BUILDFIXED
   5150 local int fixed_built = 0;
   5151 #define	FIXEDH 544	/* number of hufts used by fixed tables */
   5152 local inflate_huft fixed_mem[FIXEDH];
   5153 local uInt fixed_bl;
   5154 local uInt fixed_bd;
   5155 local inflate_huft *fixed_tl;
   5156 local inflate_huft *fixed_td;
   5157 #else
   5158 #include "inffixed.h"
   5159 #endif
   5160 
   5161 /*ARGSUSED*/
   5162 int
   5163 inflate_trees_fixed(bl, bd, tl, td, z)
   5164 uIntf *bl;	/* literal desired/actual bit depth */
   5165 uIntf *bd;	/* distance desired/actual bit depth */
   5166 const inflate_huft * FAR *tl;	/* literal/length tree result */
   5167 const inflate_huft * FAR *td;	/* distance tree result */
   5168 z_streamp z;	/* for memory allocation */
   5169 {
   5170 #ifdef BUILDFIXED
   5171 	/*
   5172 	 * build fixed tables if not already (multiple overlapped
   5173 	 * executions ok)
   5174 	 */
   5175 	if (!fixed_built)
   5176 	{
   5177 		int k;	/* temporary variable */
   5178 		uInt f = 0;	/* number of hufts used in fixed_mem */
   5179 		uIntf *c;	/* length list for huft_build */
   5180 		uIntf *v;
   5181 
   5182 		/* allocate memory */
   5183 		if ((c = (uIntf*)ZALLOC(z, 288, sizeof (uInt))) == Z_NULL)
   5184 			return (Z_MEM_ERROR);
   5185 		if ((v = (uIntf*)ZALLOC(z, 288, sizeof (uInt))) == Z_NULL)
   5186 		{
   5187 			ZFREE(z, c);
   5188 			return (Z_MEM_ERROR);
   5189 		}
   5190 		/* literal table */
   5191 		for (k = 0; k < 144; k++)
   5192 			c[k] = 8;
   5193 		for (; k < 256; k++)
   5194 			c[k] = 9;
   5195 		for (; k < 280; k++)
   5196 			c[k] = 7;
   5197 		for (; k < 288; k++)
   5198 			c[k] = 8;
   5199 		fixed_bl = 9;
   5200 		(void) huft_build(c, 288, 257, cplens, cplext, &fixed_tl,
   5201 		    &fixed_bl, fixed_mem, &f, v);
   5202 
   5203 		/* distance table */
   5204 		for (k = 0; k < 30; k++)
   5205 			c[k] = 5;
   5206 		fixed_bd = 5;
   5207 		(void) huft_build(c, 30, 0, cpdist, cpdext, &fixed_td,
   5208 		    &fixed_bd, fixed_mem, &f, v);
   5209 
   5210 		/* done */
   5211 		ZFREE(z, v);
   5212 		ZFREE(z, c);
   5213 		fixed_built = 1;
   5214 	}
   5215 #endif
   5216 	*bl = fixed_bl;
   5217 	*bd = fixed_bd;
   5218 	*tl = fixed_tl;
   5219 	*td = fixed_td;
   5220 	return (Z_OK);
   5221 }
   5222 /* --- inftrees.c */
   5223 
   5224 /* +++ infcodes.c */
   5225 /*
   5226  * infcodes.c -- process literals and length/distance pairs
   5227  * Copyright (C) 1995-1998 Mark Adler
   5228  * For conditions of distribution and use, see copyright notice in zlib.h
   5229  */
   5230 
   5231 /* #include "zutil.h" */
   5232 /* #include "inftrees.h" */
   5233 /* #include "infblock.h" */
   5234 /* #include "infcodes.h" */
   5235 /* #include "infutil.h" */
   5236 
   5237 /* +++ inffast.h */
   5238 /*
   5239  * inffast.h -- header to use inffast.c
   5240  * Copyright (C) 1995-1998 Mark Adler
   5241  * For conditions of distribution and use, see copyright notice in zlib.h
   5242  */
   5243 
   5244 /*
   5245  * WARNING: this file should *not* be used by applications. It is part
   5246  * of the implementation of the compression library and is subject to
   5247  * change. Applications should only use zlib.h.
   5248  */
   5249 
   5250 extern int inflate_fast OF((
   5251     uInt,
   5252     uInt,
   5253     const inflate_huft *,
   5254     const inflate_huft *,
   5255     inflate_blocks_statef *,
   5256     z_streamp));
   5257 /* --- inffast.h */
   5258 
   5259 /* simplify the use of the inflate_huft type with some defines */
   5260 #define	exop word.what.Exop
   5261 #define	bits word.what.Bits
   5262 
   5263 /* inflate codes private state */
   5264 struct inflate_codes_state {
   5265 
   5266 	/* mode */
   5267 	enum {	/* waiting for "i:"=input, "o:"=output, "x:"=nothing */
   5268 		START,	/* x: set up for LEN */
   5269 		LEN,	/* i: get length/literal/eob next */
   5270 		LENEXT,	/* i: getting length extra (have base) */
   5271 		DIST,	/* i: get distance next */
   5272 		DISTEXT,	/* i: getting distance extra */
   5273 		COPY,	/* o: copying bytes in window, waiting for space */
   5274 		LIT,	/* o: got literal, waiting for output space */
   5275 		WASH,	/* o: got eob, possibly still output waiting */
   5276 		END,	/* x: got eob and all data flushed */
   5277 		BADCODE}	/* x: got error */
   5278 	mode;	/* current inflate_codes mode */
   5279 
   5280 	/* mode dependent information */
   5281 	uInt len;
   5282 	union {
   5283 		struct {
   5284 			const inflate_huft *tree;	/* pointer into tree */
   5285 			uInt need;	/* bits needed */
   5286 		} code;	/* if LEN or DIST, where in tree */
   5287 		uInt lit;	/* if LIT, literal */
   5288 		struct {
   5289 			uInt get;	/* bits to get for extra */
   5290 			uInt dist;	/* distance back to copy from */
   5291 		} copy;	/* if EXT or COPY, where and how much */
   5292 	} sub;	/* submode */
   5293 
   5294 	/* mode independent information */
   5295 	Byte lbits;	/* ltree bits decoded per branch */
   5296 	Byte dbits;	/* dtree bits decoder per branch */
   5297 	const inflate_huft *ltree;	/* literal/length/eob tree */
   5298 	const inflate_huft *dtree;	/* distance tree */
   5299 
   5300 };
   5301 
   5302 
   5303 inflate_codes_statef *
   5304 inflate_codes_new(bl, bd, tl, td, z)
   5305 uInt bl, bd;
   5306 const inflate_huft *tl;
   5307 const inflate_huft *td;	/* need separate declaration for Borland C++ */
   5308 z_streamp z;
   5309 {
   5310 	inflate_codes_statef *c;
   5311 
   5312 	if ((c = (inflate_codes_statef *)
   5313 	    ZALLOC(z, 1, sizeof (struct inflate_codes_state))) != Z_NULL)
   5314 	{
   5315 		c->mode = START;
   5316 		c->lbits = (Byte)bl;
   5317 		c->dbits = (Byte)bd;
   5318 		c->ltree = tl;
   5319 		c->dtree = td;
   5320 		Tracev((stderr, "inflate:       codes new\n"));
   5321 	}
   5322 	return (c);
   5323 }
   5324 
   5325 
   5326 int
   5327 inflate_codes(s, z, r)
   5328 inflate_blocks_statef *s;
   5329 z_streamp z;
   5330 int r;
   5331 {
   5332 	uInt j;	/* temporary storage */
   5333 	const inflate_huft *t;	/* temporary pointer */
   5334 	uInt e;	/* extra bits or operation */
   5335 	uLong b;	/* bit buffer */
   5336 	uInt k;	/* bits in bit buffer */
   5337 	Bytef *p;	/* input data pointer */
   5338 	uInt n;	/* bytes available there */
   5339 	Bytef *q;	/* output window write pointer */
   5340 	uInt m;	/* bytes to end of window or read pointer */
   5341 	Bytef *f;	/* pointer to copy strings from */
   5342 	inflate_codes_statef *c = s->sub.decode.codes;	/* codes state */
   5343 
   5344 	/* copy input/output information to locals (UPDATE macro restores) */
   5345 	LOAD;
   5346 
   5347 	/* process input and output based on current state */
   5348 	/* CONSTCOND */
   5349 	while (1)
   5350 		/* waiting for "i:"=input, "o:"=output, "x:"=nothing */
   5351 		switch (c->mode) {
   5352 		case START:	/* x: set up for LEN */
   5353 #ifndef SLOW
   5354 			if (m >= 258 && n >= 10)
   5355 			{
   5356 				UPDATE;
   5357 				r = inflate_fast(c->lbits, c->dbits,
   5358 				    c->ltree, c->dtree, s, z);
   5359 				LOAD;
   5360 				if (r != Z_OK) {
   5361 					c->mode = r == Z_STREAM_END ?
   5362 					    WASH : BADCODE;
   5363 					break;
   5364 				}
   5365 			}
   5366 #endif /* !SLOW */
   5367 			c->sub.code.need = c->lbits;
   5368 			c->sub.code.tree = c->ltree;
   5369 			c->mode = LEN;
   5370 			/* FALLTHRU */
   5371 		case LEN:	/* i: get length/literal/eob next */
   5372 			j = c->sub.code.need;
   5373 			NEEDBITS(j);
   5374 			t = c->sub.code.tree +
   5375 			    ((uInt)b & inflate_mask[j]);
   5376 			DUMPBITS(t->bits);
   5377 			e = (uInt)(t->exop);
   5378 			if (e == 0) {	/* literal */
   5379 				c->sub.lit = t->base;
   5380 				Tracevv((stderr, t->base >= 0x20 &&
   5381 				    t->base < 0x7f ?
   5382 				    "inflate:         literal '%c'\n" :
   5383 				    "inflate:         literal 0x%02x\n",
   5384 				    t->base));
   5385 				c->mode = LIT;
   5386 				break;
   5387 			}
   5388 			if (e & 16) {	/* length */
   5389 				c->sub.copy.get = e & 15;
   5390 				c->len = t->base;
   5391 				c->mode = LENEXT;
   5392 				break;
   5393 			}
   5394 			if ((e & 64) == 0) {	/* next table */
   5395 				c->sub.code.need = e;
   5396 				c->sub.code.tree = t + t->base;
   5397 				break;
   5398 			}
   5399 			if (e & 32) {	/* end of block */
   5400 				Tracevv((stderr,
   5401 				    "inflate:         end of block\n"));
   5402 				c->mode = WASH;
   5403 				break;
   5404 			}
   5405 			c->mode = BADCODE;	/* invalid code */
   5406 			z->msg = "invalid literal/length code";
   5407 			r = Z_DATA_ERROR;
   5408 			LEAVE
   5409 		case LENEXT:	/* i: getting length extra (have base) */
   5410 			j = c->sub.copy.get;
   5411 			NEEDBITS(j);
   5412 			c->len += (uInt)b & inflate_mask[j];
   5413 			DUMPBITS(j);
   5414 			c->sub.code.need = c->dbits;
   5415 			c->sub.code.tree = c->dtree;
   5416 			Tracevv((stderr,
   5417 			    "inflate:         length %u\n", c->len));
   5418 			c->mode = DIST;
   5419 			/* FALLTHRU */
   5420 		case DIST:	/* i: get distance next */
   5421 			j = c->sub.code.need;
   5422 			NEEDBITS(j);
   5423 			t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
   5424 			DUMPBITS(t->bits);
   5425 			e = (uInt)(t->exop);
   5426 			if (e & 16) {	/* distance */
   5427 				c->sub.copy.get = e & 15;
   5428 				c->sub.copy.dist = t->base;
   5429 				c->mode = DISTEXT;
   5430 				break;
   5431 			}
   5432 			if ((e & 64) == 0) {	/* next table */
   5433 				c->sub.code.need = e;
   5434 				c->sub.code.tree = t + t->base;
   5435 				break;
   5436 			}
   5437 			c->mode = BADCODE;	/* invalid code */
   5438 			z->msg = "invalid distance code";
   5439 			r = Z_DATA_ERROR;
   5440 			LEAVE
   5441 		case DISTEXT:	/* i: getting distance extra */
   5442 			j = c->sub.copy.get;
   5443 			NEEDBITS(j);
   5444 			c->sub.copy.dist += (uInt)b & inflate_mask[j];
   5445 			DUMPBITS(j);
   5446 			Tracevv((stderr,
   5447 			    "inflate:         distance %u\n",
   5448 			    c->sub.copy.dist));
   5449 			c->mode = COPY;
   5450 			/* FALLTHRU */
   5451 		case COPY:
   5452 			/* o: copying bytes in window, waiting for space */
   5453 #ifndef __TURBOC__ /* Turbo C bug for following expression */
   5454 			f = (uInt)(q - s->window) < c->sub.copy.dist ?
   5455 			    s->end - (c->sub.copy.dist - (q - s->window)) :
   5456 				q - c->sub.copy.dist;
   5457 #else
   5458 			f = q - c->sub.copy.dist;
   5459 			if ((uInt)(q - s->window) < c->sub.copy.dist)
   5460 				f = s->end - (c->sub.copy.dist -
   5461 				    (uInt)(q - s->window));
   5462 #endif
   5463 			while (c->len)
   5464 			{
   5465 				NEEDOUT;
   5466 				OUTBYTE(*f++);
   5467 				if (f == s->end)
   5468 					f = s->window;
   5469 				c->len--;
   5470 			}
   5471 			c->mode = START;
   5472 			break;
   5473 		case LIT:	/* o: got literal, waiting for output space */
   5474 			NEEDOUT;
   5475 			OUTBYTE(c->sub.lit);
   5476 			c->mode = START;
   5477 			break;
   5478 		case WASH:	/* o: got eob, possibly more output */
   5479 			if (k > 7) {	/* return unused byte, if any */
   5480 				Assert(k < 16,
   5481 				    "inflate_codes grabbed too many bytes");
   5482 				k -= 8;
   5483 				n++;
   5484 				p--;	/* can always return one */
   5485 			}
   5486 			FLUSH;
   5487 			if (s->read != s->write)
   5488 				LEAVE
   5489 			c->mode = END;
   5490 			/* FALLTHRU */
   5491 		case END:
   5492 			r = Z_STREAM_END;
   5493 			LEAVE
   5494 		case BADCODE:	/* x: got error */
   5495 			r = Z_DATA_ERROR;
   5496 			LEAVE
   5497 		default:
   5498 			r = Z_STREAM_ERROR;
   5499 			LEAVE
   5500 		}
   5501 	/* NOTREACHED */
   5502 	/* otherwise lint complains */
   5503 }
   5504 
   5505 
   5506 void
   5507 inflate_codes_free(c, z)
   5508 inflate_codes_statef *c;
   5509 z_streamp z;
   5510 {
   5511 	ZFREE(z, c);
   5512 	Tracev((stderr, "inflate:       codes free\n"));
   5513 }
   5514 /* --- infcodes.c */
   5515 
   5516 /* +++ infutil.c */
   5517 /*
   5518  * inflate_util.c -- data and routines common to blocks and codes
   5519  * Copyright (C) 1995-1998 Mark Adler
   5520  * For conditions of distribution and use, see copyright notice in zlib.h
   5521  */
   5522 
   5523 /* #include "zutil.h" */
   5524 /* #include "infblock.h" */
   5525 /* #include "inftrees.h" */
   5526 /* #include "infcodes.h" */
   5527 /* #include "infutil.h" */
   5528 
   5529 #ifndef NO_DUMMY_DECL
   5530 struct inflate_codes_state {int dummy; };	/* for buggy compilers */
   5531 #endif
   5532 
   5533 /* And'ing with mask[n] masks the lower n bits */
   5534 uInt inflate_mask[17] = {
   5535 	0x0000,
   5536 	0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
   5537 	0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
   5538 };
   5539 
   5540 
   5541 /* copy as much as possible from the sliding window to the output area */
   5542 int
   5543 inflate_flush(s, z, r)
   5544 inflate_blocks_statef *s;
   5545 z_streamp z;
   5546 int r;
   5547 {
   5548 	uInt n;
   5549 	Bytef *p;
   5550 	Bytef *q;
   5551 
   5552 	/* local copies of source and destination pointers */
   5553 	p = z->next_out;
   5554 	q = s->read;
   5555 
   5556 	/* compute number of bytes to copy as far as end of window */
   5557 	n = (uInt)((q <= s->write ? s->write : s->end) - q);
   5558 	if (n > z->avail_out) n = z->avail_out;
   5559 	if (n && r == Z_BUF_ERROR) r = Z_OK;
   5560 
   5561 	/* update counters */
   5562 	z->avail_out -= n;
   5563 	z->total_out += n;
   5564 
   5565 	/* update check information */
   5566 	if (s->checkfn != Z_NULL)
   5567 		z->adler = s->check = (*s->checkfn)(s->check, q, n);
   5568 
   5569 	/* copy as far as end of window */
   5570 	if (p != Z_NULL) {	/* PPP */
   5571 		zmemcpy(p, q, n);
   5572 		p += n;
   5573 	}	/* PPP */
   5574 	q += n;
   5575 
   5576 	/* see if more to copy at beginning of window */
   5577 	if (q == s->end)
   5578 	{
   5579 		/* wrap pointers */
   5580 		q = s->window;
   5581 		if (s->write == s->end)
   5582 			s->write = s->window;
   5583 
   5584 		/* compute bytes to copy */
   5585 		n = (uInt)(s->write - q);
   5586 		if (n > z->avail_out) n = z->avail_out;
   5587 		if (n && r == Z_BUF_ERROR) r = Z_OK;
   5588 
   5589 		/* update counters */
   5590 		z->avail_out -= n;
   5591 		z->total_out += n;
   5592 
   5593 		/* update check information */
   5594 		if (s->checkfn != Z_NULL)
   5595 			z->adler = s->check = (*s->checkfn)(s->check, q, n);
   5596 
   5597 		/* copy */
   5598 		if (p != Z_NULL) {	/* PPP */
   5599 			zmemcpy(p, q, n);
   5600 			p += n;
   5601 		}	/* PPP */
   5602 		q += n;
   5603 	}
   5604 
   5605 	/* update pointers */
   5606 	z->next_out = p;
   5607 	s->read = q;
   5608 
   5609 	/* done */
   5610 	return (r);
   5611 }
   5612 /* --- infutil.c */
   5613 
   5614 /* +++ inffast.c */
   5615 /*
   5616  * inffast.c -- process literals and length/distance pairs fast
   5617  * Copyright (C) 1995-1998 Mark Adler
   5618  * For conditions of distribution and use, see copyright notice in zlib.h
   5619  */
   5620 
   5621 /* #include "zutil.h" */
   5622 /* #include "inftrees.h" */
   5623 /* #include "infblock.h" */
   5624 /* #include "infcodes.h" */
   5625 /* #include "infutil.h" */
   5626 /* #include "inffast.h" */
   5627 
   5628 #ifndef NO_DUMMY_DECL
   5629 struct inflate_codes_state {int dummy; };	/* for buggy compilers */
   5630 #endif
   5631 
   5632 /* simplify the use of the inflate_huft type with some defines */
   5633 #define	exop word.what.Exop
   5634 #define	bits word.what.Bits
   5635 
   5636 /* macros for bit input with no checking and for returning unused bytes */
   5637 #define	GRABBITS(j) { while (k < (j)) {b |= ((uLong)NEXTBYTE)<<k; k += 8; }}
   5638 #define	UNGRAB {c = z->avail_in-n; c = (k>>3) < c?k>>3:c; n += c; p -= c; \
   5639 	k -= c<<3; }
   5640 
   5641 /*
   5642  * Called with number of bytes left to write in window at least 258
   5643  * (the maximum string length) and number of input bytes available at
   5644  * least ten.  The ten bytes are six bytes for the longest length/
   5645  * distance pair plus four bytes for overloading the bit buffer.
   5646  */
   5647 
   5648 int
   5649 inflate_fast(bl, bd, tl, td, s, z)
   5650 uInt bl, bd;
   5651 const inflate_huft *tl;
   5652 const inflate_huft *td;	/* need separate declaration for Borland C++ */
   5653 inflate_blocks_statef *s;
   5654 z_streamp z;
   5655 {
   5656 	const inflate_huft *t;	/* temporary pointer */
   5657 	uInt e;	/* extra bits or operation */
   5658 	uLong b;	/* bit buffer */
   5659 	uInt k;	/* bits in bit buffer */
   5660 	Bytef *p;	/* input data pointer */
   5661 	uInt n;	/* bytes available there */
   5662 	Bytef *q;	/* output window write pointer */
   5663 	uInt m;	/* bytes to end of window or read pointer */
   5664 	uInt ml;	/* mask for literal/length tree */
   5665 	uInt md;	/* mask for distance tree */
   5666 	uInt c;	/* bytes to copy */
   5667 	uInt d;	/* distance back to copy from */
   5668 	Bytef *r;	/* copy source pointer */
   5669 
   5670 	/* load input, output, bit values */
   5671 	LOAD;
   5672 
   5673 	/* initialize masks */
   5674 	ml = inflate_mask[bl];
   5675 	md = inflate_mask[bd];
   5676 
   5677 	/* do until not enough input or output space for fast loop */
   5678 	do {	/* assume called with m >= 258 && n >= 10 */
   5679 		/* get literal/length code */
   5680 		/* max bits for literal/length code */
   5681 		GRABBITS(20);
   5682 		if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) {
   5683 			DUMPBITS(t->bits);
   5684 			Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
   5685 			    "inflate:         * literal '%c'\n" :
   5686 			    "inflate:         * literal 0x%02x\n", t->base));
   5687 			*q++ = (Byte)t->base;
   5688 			m--;
   5689 			continue;
   5690 		}
   5691 		do {
   5692 			DUMPBITS(t->bits);
   5693 			if (e & 16) {
   5694 				/* get extra bits for length */
   5695 				e &= 15;
   5696 				c = t->base + ((uInt)b & inflate_mask[e]);
   5697 				DUMPBITS(e);
   5698 				Tracevv((stderr,
   5699 				    "inflate:         * length %u\n", c));
   5700 
   5701 				/* decode distance base of block to copy */
   5702 				GRABBITS(15);	/* max bits for distance code */
   5703 				e = (t = td + ((uInt)b & md))->exop;
   5704 				do {
   5705 					DUMPBITS(t->bits);
   5706 					if (e & 16) {
   5707 						/*
   5708 						 * get extra bits to
   5709 						 * add to distance
   5710 						 * base
   5711 						 */
   5712 						e &= 15;
   5713 						/* get extra bits (up to 13) */
   5714 						GRABBITS(e);
   5715 						d = t->base + ((uInt)b &
   5716 						    inflate_mask[e]);
   5717 						DUMPBITS(e);
   5718 						Tracevv((stderr,
   5719 						    "inflate:         * "
   5720 						    "distance %u\n", d));
   5721 
   5722 						/* do the copy */
   5723 						m -= c;
   5724 						/* offset before dest */
   5725 						if ((uInt)(q - s->window) >= d)
   5726 							/*  just copy */
   5727 						{
   5728 							r = q - d;
   5729 							/*
   5730 							 * minimum
   5731 							 * count is
   5732 							 * three, so
   5733 							 * unroll loop
   5734 							 * a little
   5735 							 */
   5736 							*q++ = *r++;  c--;
   5737 							*q++ = *r++;  c--;
   5738 						}
   5739 					/* else offset after destination */
   5740 						else {
   5741 	/* bytes from offset to end */
   5742 							e = d - (uInt)(q -
   5743 							    s->window);
   5744 	/* pointer to offset */
   5745 							r = s->end - e;
   5746 							/* if source crosses */
   5747 							if (c > e) {
   5748 	/* copy to end of window */
   5749 								c -= e;
   5750 								do {
   5751 									*q++ =
   5752 									    *r
   5753 									    ++;
   5754 								} while (--e);
   5755 	/* copy rest from start of window */
   5756 								r = s->window;
   5757 							}
   5758 						}
   5759 						/* copy all or what's left */
   5760 						do {
   5761 							*q++ = *r++;
   5762 						} while (--c);
   5763 						break;
   5764 					} else if ((e & 64) == 0) {
   5765 						t += t->base;
   5766 						e = (t += ((uInt)b &
   5767 						    inflate_mask[e]))->exop;
   5768 					} else {
   5769 						z->msg =
   5770 						    "invalid distance code";
   5771 						UNGRAB;
   5772 						UPDATE;
   5773 						return (Z_DATA_ERROR);
   5774 					}
   5775 					/* CONSTCOND */
   5776 				} while (1);
   5777 				break;
   5778 			}
   5779 			if ((e & 64) == 0)
   5780 			{
   5781 				t += t->base;
   5782 				if ((e = (t += ((uInt)b &
   5783 				    inflate_mask[e]))->exop) == 0)
   5784 				{
   5785 					DUMPBITS(t->bits);
   5786 					Tracevv((stderr, t->base >= 0x20 &&
   5787 					    t->base < 0x7f ?
   5788 					    "inflate:         * literal '%c'\n"
   5789 					    :
   5790 					    "inflate:         * literal "
   5791 					    "0x%02x\n", t->base));
   5792 					*q++ = (Byte)t->base;
   5793 					m--;
   5794 					break;
   5795 				}
   5796 			} else if (e & 32) {
   5797 				Tracevv((stderr,
   5798 				    "inflate:         * end of block\n"));
   5799 				UNGRAB;
   5800 				UPDATE;
   5801 				return (Z_STREAM_END);
   5802 			} else {
   5803 				z->msg = "invalid literal/length code";
   5804 				UNGRAB;
   5805 				UPDATE;
   5806 				return (Z_DATA_ERROR);
   5807 			}
   5808 			/* CONSTCOND */
   5809 		} while (1);
   5810 	} while (m >= 258 && n >= 10);
   5811 
   5812 	/* not enough input or output--restore pointers and return */
   5813 	UNGRAB;
   5814 	UPDATE;
   5815 	return (Z_OK);
   5816 }
   5817 /* --- inffast.c */
   5818 
   5819 /* +++ zutil.c */
   5820 /*
   5821  * zutil.c -- target dependent utility functions for the compression library
   5822  * Copyright (C) 1995-1998 Jean-loup Gailly.
   5823  * For conditions of distribution and use, see copyright notice in zlib.h
   5824  */
   5825 
   5826 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */
   5827 
   5828 #ifdef DEBUG_ZLIB
   5829 #include <stdio.h>
   5830 #endif
   5831 
   5832 /* #include "zutil.h" */
   5833 
   5834 #ifndef NO_DUMMY_DECL
   5835 struct internal_state	{int dummy; };	/* for buggy compilers */
   5836 #endif
   5837 
   5838 #ifndef STDC
   5839 extern void exit OF((int));
   5840 #endif
   5841 
   5842 static const char *z_errmsg[10] = {
   5843 "need dictionary",	/* Z_NEED_DICT		2 */
   5844 "stream end",		/* Z_STREAM_END		1 */
   5845 "",			/* Z_OK			0 */
   5846 "file error",		/* Z_ERRNO		(-1) */
   5847 "stream error",		/* Z_STREAM_ERROR	(-2) */
   5848 "data error",		/* Z_DATA_ERROR		(-3) */
   5849 "insufficient memory",	/* Z_MEM_ERROR		(-4) */
   5850 "buffer error",		/* Z_BUF_ERROR		(-5) */
   5851 "incompatible version",	/* Z_VERSION_ERROR	(-6) */
   5852 ""};
   5853 
   5854 
   5855 const char *
   5856 zlibVersion()
   5857 {
   5858 	return (ZLIB_VERSION);
   5859 }
   5860 
   5861 #ifdef DEBUG_ZLIB
   5862 void
   5863 z_error(m)
   5864     char *m;
   5865 {
   5866 	fprintf(stderr, "%s\n", m);
   5867 	exit(1);
   5868 }
   5869 #endif
   5870 
   5871 #ifndef HAVE_MEMCPY
   5872 
   5873 void
   5874 zmemcpy(dest, source, len)
   5875     Bytef* dest;
   5876     const Bytef* source;
   5877     uInt  len;
   5878 {
   5879 	if (len == 0)
   5880 		return;
   5881 	do {
   5882 		*dest++ = *source++;	/* ??? to be unrolled */
   5883 	} while (--len != 0);
   5884 }
   5885 
   5886 int
   5887 zmemcmp(s1, s2, len)
   5888 const Bytef* s1;
   5889 const Bytef* s2;
   5890 uInt  len;
   5891 {
   5892 	uInt j;
   5893 
   5894 	for (j = 0; j < len; j++) {
   5895 		if (s1[j] != s2[j])
   5896 			return (2*(s1[j] > s2[j])-1);
   5897 	}
   5898 	return (0);
   5899 }
   5900 
   5901 void
   5902 zmemzero(dest, len)
   5903     Bytef* dest;
   5904     uInt  len;
   5905 {
   5906 	if (len == 0)
   5907 		return;
   5908 	do {
   5909 		*dest++ = 0;	/* ??? to be unrolled */
   5910 	} while (--len != 0);
   5911 }
   5912 #endif
   5913 
   5914 #ifdef __TURBOC__
   5915 #if (defined(__BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
   5916 /*
   5917  * Small and medium model in Turbo C are for now limited to near
   5918  * allocation with reduced MAX_WBITS and MAX_MEM_LEVEL
   5919  */
   5920 #define	MY_ZCALLOC
   5921 
   5922 /*
   5923  * Turbo C malloc() does not allow dynamic allocation of 64K bytes and
   5924  * farmalloc(64K) returns a pointer with an offset of 8, so we must
   5925  * fix the pointer. Warning: the pointer must be put back to its
   5926  * original form in order to free it, use zcfree().
   5927  */
   5928 
   5929 #define	MAX_PTR 10
   5930 /* 10*64K = 640K */
   5931 
   5932 local int next_ptr = 0;
   5933 
   5934 typedef struct ptr_table_s {
   5935 	voidpf org_ptr;
   5936 	voidpf new_ptr;
   5937 } ptr_table;
   5938 
   5939 local ptr_table table[MAX_PTR];
   5940 /*
   5941  * This table is used to remember the original form of pointers to
   5942  * large buffers (64K). Such pointers are normalized with a zero
   5943  * offset.  Since MSDOS is not a preemptive multitasking OS, this
   5944  * table is not protected from concurrent access. This hack doesn't
   5945  * work anyway on a protected system like OS/2. Use Microsoft C
   5946  * instead.
   5947  */
   5948 
   5949 voidpf
   5950 zcalloc(voidpf opaque, unsigned items, unsigned size)
   5951 {
   5952 	voidpf buf = opaque;	/* just to make some compilers happy */
   5953 	ulg bsize = (ulg)items*size;
   5954 
   5955 	/*
   5956 	 * If we allocate less than 65520 bytes, we assume that
   5957 	 * farmalloc will return a usable pointer which doesn't have
   5958 	 * to be normalized.
   5959 	 */
   5960 	if (bsize < 65520L) {
   5961 		buf = farmalloc(bsize);
   5962 		if (*(ush *)&buf != 0)
   5963 			return (buf);
   5964 	} else {
   5965 		buf = farmalloc(bsize + 16L);
   5966 	}
   5967 	if (buf == NULL || next_ptr >= MAX_PTR)
   5968 		return (NULL);
   5969 	table[next_ptr].org_ptr = buf;
   5970 
   5971 	/* Normalize the pointer to seg:0 */
   5972 	*((ush *)&buf+1) += ((ush)((uch *)buf-0) + 15) >> 4;
   5973 	*(ush *)&buf = 0;
   5974 	table[next_ptr++].new_ptr = buf;
   5975 	return (buf);
   5976 }
   5977 
   5978 void
   5979 zcfree(voidpf opaque, voidpf ptr)
   5980 {
   5981 	int n;
   5982 	if (*(ush*)&ptr != 0) { /* object < 64K */
   5983 		farfree(ptr);
   5984 		return;
   5985 	}
   5986 	/* Find the original pointer */
   5987 	for (n = 0; n < next_ptr; n++) {
   5988 		if (ptr != table[n].new_ptr)
   5989 			continue;
   5990 
   5991 		farfree(table[n].org_ptr);
   5992 		while (++n < next_ptr) {
   5993 			table[n-1] = table[n];
   5994 		}
   5995 		next_ptr--;
   5996 		return;
   5997 	}
   5998 	ptr = opaque;	/* just to make some compilers happy */
   5999 	Assert(0, "zcfree: ptr not found");
   6000 }
   6001 #endif
   6002 #endif /* __TURBOC__ */
   6003 
   6004 
   6005 #if defined(M_I86) && !defined(__32BIT__)
   6006 /* Microsoft C in 16-bit mode */
   6007 
   6008 #define	MY_ZCALLOC
   6009 
   6010 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
   6011 #define	_halloc  halloc
   6012 #define	_hfree   hfree
   6013 #endif
   6014 
   6015 voidpf
   6016 zcalloc(voidpf opaque, unsigned items, unsigned size)
   6017 {
   6018 	if (opaque) opaque = 0;	/* to make compiler happy */
   6019 	return (_halloc((long)items, size));
   6020 }
   6021 
   6022 void
   6023 zcfree(voidpf opaque, voidpf ptr)
   6024 {
   6025 	if (opaque) opaque = 0;	/* to make compiler happy */
   6026 	_hfree(ptr);
   6027 }
   6028 
   6029 #endif /* MSC */
   6030 
   6031 
   6032 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
   6033 
   6034 #ifndef STDC
   6035 extern voidp  calloc OF((uInt items, uInt size));
   6036 extern void   free   OF((voidpf ptr));
   6037 #endif
   6038 
   6039 voidpf
   6040 zcalloc(opaque, items, size)
   6041     voidpf opaque;
   6042     unsigned items;
   6043     unsigned size;
   6044 {
   6045 	if (opaque) items += size - size;	/* make compiler happy */
   6046 	return ((voidpf)calloc(items, size));
   6047 }
   6048 
   6049 /*ARGSUSED*/
   6050 void
   6051 zcfree(opaque, ptr)
   6052     voidpf opaque;
   6053     voidpf ptr;
   6054 {
   6055 	free(ptr);
   6056 }
   6057 
   6058 #endif /* MY_ZCALLOC */
   6059 /* --- zutil.c */
   6060 
   6061 /* +++ adler32.c */
   6062 /*
   6063  * adler32.c -- compute the Adler-32 checksum of a data stream
   6064  * Copyright (C) 1995-1998 Mark Adler
   6065  * For conditions of distribution and use, see copyright notice in zlib.h
   6066  */
   6067 
   6068 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */
   6069 
   6070 /* #include "zlib.h" */
   6071 
   6072 #define	BASE 65521L /* largest prime smaller than 65536 */
   6073 #define	NMAX 5552
   6074 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
   6075 
   6076 #define	DO1(buf, i)  {s1 += buf[i]; s2 += s1; }
   6077 #define	DO2(buf, i)  DO1(buf, i); DO1(buf, i+1);
   6078 #define	DO4(buf, i)  DO2(buf, i); DO2(buf, i+2);
   6079 #define	DO8(buf, i)  DO4(buf, i); DO4(buf, i+4);
   6080 #define	DO16(buf)   DO8(buf, 0); DO8(buf, 8);
   6081 
   6082 /* ========================================================================= */
   6083 uLong
   6084 adler32(adler, buf, len)
   6085     uLong adler;
   6086     const Bytef *buf;
   6087     uInt len;
   6088 {
   6089 	unsigned long s1 = adler & 0xffff;
   6090 	unsigned long s2 = (adler >> 16) & 0xffff;
   6091 	int k;
   6092 
   6093 	if (buf == Z_NULL)
   6094 		return (1L);
   6095 
   6096 	while (len > 0) {
   6097 		k = len < NMAX ? len : NMAX;
   6098 		len -= k;
   6099 		while (k >= 16) {
   6100 			DO16(buf);
   6101 			buf += 16;
   6102 			k -= 16;
   6103 		}
   6104 		if (k != 0) do {
   6105 			s1 += *buf++;
   6106 			s2 += s1;
   6107 		} while (--k);
   6108 		s1 %= BASE;
   6109 		s2 %= BASE;
   6110 	}
   6111 	return ((s2 << 16) | s1);
   6112 }
   6113 /* --- adler32.c */
   6114