xref: /illumos-gate/usr/src/uts/common/io/ppp/spppcomp/zlib.c (revision 843e19887f64dde75055cf8842fc4db2171eff45)

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Updated from zlib-1.0.4 to zlib-1.1.3 by James Carlson.
 *
 * This file is derived from various .h and .c files from the zlib-1.0.4
 * distribution by Jean-loup Gailly and Mark Adler, with some additions
 * by Paul Mackerras to aid in implementing Deflate compression and
 * decompression for PPP packets.  See zlib.h for conditions of
 * distribution and use.
 *
 * Changes that have been made include:
 * - added Z_PACKET_FLUSH (see zlib.h for details)
 * - added inflateIncomp and deflateOutputPending
 * - allow strm->next_out to be NULL, meaning discard the output
 *
 * $Id: zlib.c,v 1.11 1998/09/13 23:37:12 paulus Exp $
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 *  ==FILEVERSION 971210==
 *
 * This marker is used by the Linux installation script to determine
 * whether an up-to-date version of this file is already installed.
 */

#define	NO_DUMMY_DECL
#define	NO_ZCFUNCS
#define	MY_ZCALLOC

#if defined(__FreeBSD__) && (defined(KERNEL) || defined(_KERNEL))
#define	inflate	inflate_ppp	/* FreeBSD already has an inflate :-( */
#endif


/* +++ zutil.h */
/*
 *
 * zutil.h -- internal interface and configuration of the compression library
 * Copyright (C) 1995-1998 Jean-loup Gailly.
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 * WARNING: this file should *not* be used by applications. It is part
 * of the implementation of the compression library and is subject to
 * change. Applications should only use zlib.h.
 */

/* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */

#ifndef _Z_UTIL_H
#define	_Z_UTIL_H

#include "zlib.h"

#if defined(KERNEL) || defined(_KERNEL)
/* Assume this is a *BSD or SVR4 kernel */
#include <sys/types.h>
#include <sys/time.h>
#include <sys/systm.h>
#ifdef SOL2
#include <sys/cmn_err.h>
#endif
#define	HAVE_MEMCPY
#define	memcmp		bcmp

#else
#if defined(__KERNEL__)
/* Assume this is a Linux kernel */
#include <linux/string.h>
#define	HAVE_MEMCPY

#else /* not kernel */

#include <stddef.h>
#ifdef NO_ERRNO_H
extern int errno;
#else
#include <errno.h>
#endif
#ifdef STDC
#include <string.h>
#include <stdlib.h>
#endif
#endif /* __KERNEL__ */
#endif /* _KERNEL || KERNEL */

#ifndef local
#define	local static
#endif
/* compile with -Dlocal if your debugger can't find static symbols */

typedef unsigned char  uch;
typedef uch FAR uchf;
typedef unsigned short ush;
typedef ush FAR ushf;
typedef unsigned long  ulg;

static const char *z_errmsg[10]; /* indexed by 2-zlib_error */
/* (size given to avoid silly warnings with Visual C++) */

#define	ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]

#define	ERR_RETURN(strm, err) \
	return (strm->msg = ERR_MSG(err), (err))
/* To be used only when the state is known to be valid */

	/* common constants */

#ifndef DEF_WBITS
#define	DEF_WBITS MAX_WBITS
#endif
/* default windowBits for decompression. MAX_WBITS is for compression only */

#if MAX_MEM_LEVEL >= 8
#define	DEF_MEM_LEVEL 8
#else
#define	DEF_MEM_LEVEL  MAX_MEM_LEVEL
#endif
/* default memLevel */

#define	STORED_BLOCK 0
#define	STATIC_TREES 1
#define	DYN_TREES    2
/* The three kinds of block type */

#define	MIN_MATCH  3
#define	MAX_MATCH  258
/* The minimum and maximum match lengths */

#define	PRESET_DICT 0x20 /* preset dictionary flag in zlib header */

	/* target dependencies */

#ifdef MSDOS
#define	OS_CODE  0x00
#ifdef __TURBOC__
#include <alloc.h>
#else /* MSC or DJGPP */
#include <malloc.h>
#endif
#endif

#ifdef OS2
#define	OS_CODE  0x06
#endif

#ifdef WIN32 /* Window 95 & Windows NT */
#define	OS_CODE  0x0b
#endif

#if defined(VAXC) || defined(VMS)
#define	OS_CODE  0x02
#define	F_OPEN(name, mode) \
	fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
#endif

#ifdef AMIGA
#define	OS_CODE  0x01
#endif

#if defined(ATARI) || defined(atarist)
#define	OS_CODE  0x05
#endif

#ifdef MACOS
#define	OS_CODE  0x07
#endif

#ifdef __50SERIES /* Prime/PRIMOS */
#define	OS_CODE  0x0F
#endif

#ifdef TOPS20
#define	OS_CODE  0x0a
#endif

#if defined(_BEOS_) || defined(RISCOS)
#define	fdopen(fd, mode) NULL /* No fdopen() */
#endif

	/* Common defaults */

#ifndef OS_CODE
#define	OS_CODE  0x03  /* assume Unix */
#endif

#ifndef F_OPEN
#define	F_OPEN(name, mode) fopen((name), (mode))
#endif

	/* functions */

#ifdef HAVE_STRERROR
extern char *strerror OF((int));
#define	zstrerror(errnum) strerror(errnum)
#else
#define	zstrerror(errnum) ""
#endif

#if defined(pyr)
#define	NO_MEMCPY
#endif
#if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
/*
 * Use our own functions for small and medium model with MSC <= 5.0.
 * You may have to use the same strategy for Borland C (untested).
 */
#define	NO_MEMCPY
#endif
#if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
#define	HAVE_MEMCPY
#endif
#ifdef HAVE_MEMCPY
#ifdef SMALL_MEDIUM /* MSDOS small or medium model */
#define	zmemcpy _fmemcpy
#define	zmemcmp _fmemcmp
#define	zmemzero(dest, len) _fmemset(dest, 0, len)
#else
#define	zmemcpy (void) memcpy
#define	zmemcmp memcmp
#define	zmemzero(dest, len) (void) memset(dest, 0, len)
#endif
#else
extern void zmemcpy  OF((Bytef* dest, const Bytef* source, uInt len));
extern int  zmemcmp  OF((const Bytef* s1, const Bytef* s2, uInt len));
extern void zmemzero OF((Bytef* dest, uInt len));
#endif

/* Diagnostic functions */
#ifdef DEBUG_ZLIB
#include <stdio.h>
#ifndef verbose
#define	verbose 0
#endif
extern void z_error    OF((char *m));
#define	Assert(cond, msg) { if (!(cond)) z_error(msg); }
#define	Trace(x) {if (z_verbose >= 0) fprintf x; }
#define	Tracev(x) {if (z_verbose > 0) fprintf x; }
#define	Tracevv(x) {if (z_verbose > 1) fprintf x; }
#define	Tracec(c, x) {if (z_verbose > 0 && (c)) fprintf x; }
#define	Tracecv(c, x) {if (z_verbose > 1 && (c)) fprintf x; }
#else
#if defined(SOL2) && defined(DEBUG)
#define	Assert(cond, msg)	((cond) ? ((void)0) : panic(msg))
#else
#define	Assert(cond, msg)	((void)0)
#endif
#define	Trace(x)	((void)0)
#define	Tracev(x)	((void)0)
#define	Tracevv(x)	((void)0)
#define	Tracec(c, x)	((void)0)
#define	Tracecv(c, x)	((void)0)
#endif


typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));

/* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
/* void   zcfree  OF((voidpf opaque, voidpf ptr)); */

#define	ZALLOC(strm, items, size) \
	(*((strm)->zalloc))((strm)->opaque, (items), (size))
#define	ZFREE(strm, addr)  (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
#define	TRY_FREE(s, p) {if (p) ZFREE(s, p); }

#endif /* _Z_UTIL_H */
/* --- zutil.h */

/* +++ deflate.h */
/*
 * deflate.h -- internal compression state
 * Copyright (C) 1995-1998 Jean-loup Gailly
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 * WARNING: this file should *not* be used by applications. It is part
 * of the implementation of the compression library and is subject to
 * change. Applications should only use zlib.h.
 */

/* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */

#ifndef _DEFLATE_H
#define	_DEFLATE_H

/* #include "zutil.h" */

/*
 * ===========================================================================
 * Internal compression state.
 */

#define	LENGTH_CODES 29
/* number of length codes, not counting the special END_BLOCK code */

#define	LITERALS  256
/* number of literal bytes 0..255 */

#define	L_CODES (LITERALS+1+LENGTH_CODES)
/* number of Literal or Length codes, including the END_BLOCK code */

#define	D_CODES   30
/* number of distance codes */

#define	BL_CODES  19
/* number of codes used to transfer the bit lengths */

#define	HEAP_SIZE (2*L_CODES+1)
/* maximum heap size */

#define	MAX_BITS 15
/* All codes must not exceed MAX_BITS bits */

#define	INIT_STATE    42
#define	BUSY_STATE   113
#define	FINISH_STATE 666
/* Stream status */


/* Data structure describing a single value and its code string. */
typedef struct ct_data_s {
	union {
		ush freq;	/* frequency count */
		ush code;	/* bit string */
	} fc;
	union {
		ush dad;	/* father node in Huffman tree */
		ush len;	/* length of bit string */
	} dl;
} FAR ct_data;

#define	Freq fc.freq
#define	Code fc.code
#define	Dad  dl.dad
#define	Len  dl.len

typedef struct static_tree_desc_s  static_tree_desc;

typedef struct tree_desc_s {
	ct_data *dyn_tree;	/* the dynamic tree */
	int	max_code;	/* largest code with non zero frequency */
	static_tree_desc *stat_desc;	/* the corresponding static tree */
} FAR tree_desc;

typedef ush Pos;
typedef Pos FAR Posf;
typedef unsigned IPos;

/*
 * A Pos is an index in the character window. We use short instead of
 * int to save space in the various tables. IPos is used only for
 * parameter passing.
 */

typedef struct deflate_state {
	z_streamp strm;	/* pointer back to this zlib stream */
	int   status;	/* as the name implies */
	Bytef *pending_buf;	/* output still pending */
	ulg   pending_buf_size;	/* size of pending_buf */
	Bytef *pending_out;	/* next pending byte to output to the stream */
	int   pending;	/* nb of bytes in the pending buffer */
	int   noheader;	/* suppress zlib header and adler32 */
	Byte  data_type;	/* UNKNOWN, BINARY or ASCII */
	Byte  method;	/* STORED (for zip only) or DEFLATED */
	/* value of flush param for previous deflate call */
	int   last_flush;

	/* used by deflate.c: */

	uInt  w_size;	/* LZ77 window size (32K by default) */
	uInt  w_bits;	/* log2(w_size)  (8..16) */
	uInt  w_mask;	/* w_size - 1 */

	Bytef *window;
	/*
	 * Sliding window. Input bytes are read into the second half
	 * of the window, and move to the first half later to keep a
	 * dictionary of at least wSize bytes. With this organization,
	 * matches are limited to a distance of wSize-MAX_MATCH bytes,
	 * but this ensures that IO is always performed with a length
	 * multiple of the block size. Also, it limits the window size
	 * to 64K, which is quite useful on MSDOS.  To do: use the
	 * user input buffer as sliding window.
	 */

	ulg window_size;
	/*
	 * Actual size of window: 2*wSize, except when the user input
	 * buffer is directly used as sliding window.
	 */

	Posf *prev;
	/*
	 * Link to older string with same hash index. To limit the
	 * size of this array to 64K, this link is maintained only for
	 * the last 32K strings.  An index in this array is thus a
	 * window index modulo 32K.
	 */

	Posf *head;	/* Heads of the hash chains or NIL. */

	uInt  ins_h;	/* hash index of string to be inserted */
	uInt  hash_size;	/* number of elements in hash table */
	uInt  hash_bits;	/* log2(hash_size) */
	uInt  hash_mask;	/* hash_size-1 */

	uInt  hash_shift;
	/*
	 * Number of bits by which ins_h must be shifted at each input
	 * step. It must be such that after MIN_MATCH steps, the
	 * oldest byte no longer takes part in the hash key, that is:
	 * hash_shift * MIN_MATCH >= hash_bits
	 */

	long block_start;
	/*
	 * Window position at the beginning of the current output
	 * block. Gets negative when the window is moved backwards.
	 */

	uInt match_length;	/* length of best match */
	IPos prev_match;	/* previous match */
	int match_available;	/* set if previous match exists */
	uInt strstart;	/* start of string to insert */
	uInt match_start;	/* start of matching string */
	uInt lookahead;	/* number of valid bytes ahead in window */

	uInt prev_length;
	/*
	 * Length of the best match at previous step. Matches not
	 * greater than this are discarded. This is used in the lazy
	 * match evaluation.
	 */

	uInt max_chain_length;
	/*
	 * To speed up deflation, hash chains are never searched
	 * beyond *this length.  A higher limit improves compression
	 * ratio but *degrades the speed.
	 */

	uInt max_lazy_match;
	/*
	 * Attempt to find a better match only when the current match
	 * is strictly smaller than this value. This mechanism is used
	 * only for compression levels >= 4.
	 */
#define	max_insert_length  max_lazy_match
	/*
	 * Insert new strings in the hash table only if the match
	 * length is not greater than this length. This saves time but
	 * degrades compression.  max_insert_length is used only for
	 * compression levels <= 3.
	 */

	int level;	/* compression level (1..9) */
	int strategy;	/* favor or force Huffman coding */

	uInt good_match;
	/* Use a faster search when the previous match is longer than this */

	int nice_match;	/* Stop searching when current match exceeds this */

	/* used by trees.c: */
	/* Didn't use ct_data typedef below to supress compiler warning */
	struct ct_data_s dyn_ltree[HEAP_SIZE];	/* literal and length tree */
	struct ct_data_s dyn_dtree[2*D_CODES+1];	/* distance tree */
	/* Huffman tree for bit lengths */
	struct ct_data_s bl_tree[2*BL_CODES+1];

	struct tree_desc_s l_desc;	/* desc. for literal tree */
	struct tree_desc_s d_desc;	/* desc. for distance tree */
	struct tree_desc_s bl_desc;	/* desc. for bit length tree */

	ush bl_count[MAX_BITS+1];
	/* number of codes at each bit length for an optimal tree */

	int heap[2*L_CODES+1];	/* heap used to build the Huffman trees */
	int heap_len;	/* number of elements in the heap */
	int heap_max;	/* element of largest frequency */
	/*
	 * The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0]
	 * is not used.  The same heap array is used to build all
	 * trees.
	 */

	uch depth[2*L_CODES+1];
	/*
	 * Depth of each subtree used as tie breaker for trees of
	 * equal frequency
	 */

	uchf *l_buf;	/* buffer for literals or lengths */

	uInt lit_bufsize;
	/*
	 * Size of match buffer for literals/lengths.  There are 4
	 * reasons for limiting lit_bufsize to 64K:
	 *
	 *   - frequencies can be kept in 16 bit counters
	 *
	 *   - if compression is not successful for the first block,
	 *   all input data is still in the window so we can still
	 *   emit a stored block even when input comes from standard
	 *   input.  (This can also be done for all blocks if
	 *   lit_bufsize is not greater than 32K.)
	 *
	 *   - if compression is not successful for a file smaller
	 *   than 64K, we can even emit a stored file instead of a
	 *   stored block (saving 5 bytes).  This is applicable only
	 *   for zip (not gzip or zlib).
	 *
	 *   - creating new Huffman trees less frequently may not
	 *   provide fast adaptation to changes in the input data
	 *   statistics. (Take for example a binary file with poorly
	 *   compressible code followed by a highly compressible
	 *   string table.) Smaller buffer sizes give fast adaptation
	 *   but have of course the overhead of transmitting trees
	 *   more frequently.
	 *
	 *   - I can't count above 4
	 */

	uInt last_lit;	/* running index in l_buf */

	ushf *d_buf;
	/*
	 * Buffer for distances. To simplify the code, d_buf and l_buf
	 * have the same number of elements. To use different lengths,
	 * an extra flag array would be necessary.
	 */

	ulg opt_len;	/* bit length of current block with optimal trees */
	ulg static_len;	/* bit length of current block with static trees */
	uInt matches;	/* number of string matches in current block */
	int last_eob_len;	/* bit length of EOB code for last block */

	ulg compressed_len;	/* total bit length of compressed file PPP */
#ifdef DEBUG_ZLIB
	ulg bits_sent;	/* bit length of the compressed data */
#endif

	ush bi_buf;
	/*
	 * Output buffer. bits are inserted starting at the bottom
	 * (least significant bits).
	 */
	int bi_valid;
	/*
	 * Number of valid bits in bi_buf.  All bits above the last
	 * valid bit are always zero.
	 */

} FAR deflate_state;

/*
 * Output a byte on the stream.  IN assertion: there is enough room in
 * pending_buf.
 */
#define	put_byte(s, c) {s->pending_buf[s->pending++] = (c); }


#define	MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
/*
 * Minimum amount of lookahead, except at the end of the input file.
 * See deflate.c for comments about the MIN_MATCH+1.
 */

#define	MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
/*
 * In order to simplify the code, particularly on 16 bit machines,
 * match distances are limited to MAX_DIST instead of WSIZE.
 */

	/* in trees.c */
void _tr_init		OF((deflate_state *s));
int  _tr_tally		OF((deflate_state *s, unsigned dist, unsigned lc));
void  _tr_flush_block	OF((deflate_state *s, charf *buf, ulg stored_len,
    int eof));
void _tr_align		OF((deflate_state *s));
void _tr_stored_block	OF((deflate_state *s, charf *buf, ulg stored_len,
    int eof));
void _tr_stored_type_only OF((deflate_state *));	/* PPP */

#define	d_code(dist) \
	((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
/*
 * Mapping from a distance to a distance code. dist is the distance - 1 and
 * must not have side effects. _dist_code[256] and _dist_code[257] are never
 * used.
 */

#ifndef DEBUG_ZLIB
/* Inline versions of _tr_tally for speed: */

local uch _length_code[];
local uch _dist_code[];

#define	_tr_tally_lit(s, c, flush) \
	{	uch cc = (c); \
		s->d_buf[s->last_lit] = 0; \
		s->l_buf[s->last_lit++] = cc; \
		s->dyn_ltree[cc].Freq++; \
		flush = (s->last_lit == s->lit_bufsize-1); \
	}
#define	_tr_tally_dist(s, distance, length, flush) \
	{	uch len = (length); \
		ush dist = (distance); \
		s->d_buf[s->last_lit] = dist; \
		s->l_buf[s->last_lit++] = len; \
		dist--; \
		s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
		s->dyn_dtree[d_code(dist)].Freq++; \
		flush = (s->last_lit == s->lit_bufsize-1); \
	}
#else
#define	_tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
#define	_tr_tally_dist(s, distance, length, flush) \
		flush = _tr_tally(s, distance, length)
#endif

#endif
/* --- deflate.h */

/* +++ deflate.c */
/*
 * deflate.c -- compress data using the deflation algorithm
 * Copyright (C) 1995-1998 Jean-loup Gailly.
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 *  ALGORITHM
 *
 *      The "deflation" process depends on being able to identify portions
 *      of the input text which are identical to earlier input (within a
 *      sliding window trailing behind the input currently being processed).
 *
 *      The most straightforward technique turns out to be the fastest for
 *      most input files: try all possible matches and select the longest.
 *      The key feature of this algorithm is that insertions into the string
 *      dictionary are very simple and thus fast, and deletions are avoided
 *      completely. Insertions are performed at each input character, whereas
 *      string matches are performed only when the previous match ends. So it
 *      is preferable to spend more time in matches to allow very fast string
 *      insertions and avoid deletions. The matching algorithm for small
 *      strings is inspired from that of Rabin & Karp. A brute force approach
 *      is used to find longer strings when a small match has been found.
 *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
 *      (by Leonid Broukhis).
 *         A previous version of this file used a more sophisticated algorithm
 *      (by Fiala and Greene) which is guaranteed to run in linear amortized
 *      time, but has a larger average cost, uses more memory and is patented.
 *      However the F&G algorithm may be faster for some highly redundant
 *      files if the parameter max_chain_length (described below) is too large.
 *
 *  ACKNOWLEDGEMENTS
 *
 *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
 *      I found it in 'freeze' written by Leonid Broukhis.
 *      Thanks to many people for bug reports and testing.
 *
 *  REFERENCES
 *
 *      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
 *      Available in ftp://ds.internic.net/rfc/rfc1951.txt
 *
 *      A description of the Rabin and Karp algorithm is given in the book
 *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
 *
 *      Fiala,E.R., and Greene,D.H.
 *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
 *
 */

/* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */

/* #include "deflate.h" */

const char deflate_copyright[] =
" deflate 1.1.3 Copyright 1995-1998 Jean-loup Gailly ";
/*
 * If you use the zlib library in a product, an acknowledgment is
 * welcome in the documentation of your product. If for some reason
 * you cannot include such an acknowledgment, I would appreciate that
 * you keep this copyright string in the executable of your product.
 */

/*
 * ===========================================================================
 *  Function prototypes.
 */
typedef enum {
	/* block not completed, need more input or more output */
	need_more,
	block_done,	/* block flush performed */
	/* finish started, need only more output at next deflate */
	finish_started,
	finish_done	/* finish done, accept no more input or output */
} block_state;

typedef block_state (*compress_func) OF((deflate_state *s, int flush));
/* Compression function. Returns the block state after the call. */

local void fill_window	OF((deflate_state *s));
local block_state deflate_stored OF((deflate_state *s, int flush));
local block_state deflate_fast	OF((deflate_state *s, int flush));
local block_state deflate_slow	OF((deflate_state *s, int flush));
local void lm_init	OF((deflate_state *s));
local void putShortMSB	OF((deflate_state *s, uInt b));
local void flush_pending	OF((z_streamp strm));
local int read_buf	OF((z_streamp strm, Bytef *buf, unsigned size));
#ifdef ASMV
void match_init	OF((void));	/* asm code initialization */
uInt longest_match	OF((deflate_state *s, IPos cur_match));
#else
local uInt longest_match	OF((deflate_state *s, IPos cur_match));
#endif

#ifdef DEBUG_ZLIB
local void check_match OF((deflate_state *s, IPos start, IPos match,
    int length));
#endif

/*
 * ===========================================================================
 * Local data
 */

#define	NIL 0
/* Tail of hash chains */

#ifndef TOO_FAR
#define	TOO_FAR 4096
#endif
/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */

#define	MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
/*
 * Minimum amount of lookahead, except at the end of the input file.
 * See deflate.c for comments about the MIN_MATCH+1.
 */

/*
 * Values for max_lazy_match, good_match and max_chain_length,
 * depending on the desired pack level (0..9). The values given below
 * have been tuned to exclude worst case performance for pathological
 * files. Better values may be found for specific files.
 */
typedef struct config_s {
	ush good_length;	/* reduce lazy search above this match length */
	ush max_lazy;	/* do not perform lazy search above this match length */
	ush nice_length;	/* quit search above this match length */
	ush max_chain;
	compress_func func;
} config;

local const config configuration_table[10] = {
/*	good lazy nice chain */
/* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
/* 1 */ {4,    4,  8,    4, deflate_fast}, /* maximum speed, no lazy matches */
/* 2 */ {4,    5, 16,    8, deflate_fast},
/* 3 */ {4,    6, 32,   32, deflate_fast},

/* 4 */ {4,    4, 16,   16, deflate_slow},  /* lazy matches */
/* 5 */ {8,   16, 32,   32, deflate_slow},
/* 6 */ {8,   16, 128, 128, deflate_slow},
/* 7 */ {8,   32, 128, 256, deflate_slow},
/* 8 */ {32, 128, 258, 1024, deflate_slow},
/* 9 */ {32, 258, 258, 4096, deflate_slow}};	/* maximum compression */

/*
 * Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
 * meaning.
 */

#define	EQUAL 0
/* result of memcmp for equal strings */

#ifndef NO_DUMMY_DECL
struct static_tree_desc_s {int dummy; };	/* for buggy compilers */
#endif

/*
 * ===========================================================================
 * Update a hash value with the given input byte
 * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
 *    input characters, so that a running hash key can be computed from the
 *    previous key instead of complete recalculation each time.
 */
#define	UPDATE_HASH(s, h, c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)


/*
 * ===========================================================================
 * Insert string str in the dictionary and set match_head to the previous head
 * of the hash chain (the most recent string with same hash key). Return
 * the previous length of the hash chain.
 * If this file is compiled with -DFASTEST, the compression level is forced
 * to 1, and no hash chains are maintained.
 * IN  assertion: all calls to to INSERT_STRING are made with consecutive
 *    input characters and the first MIN_MATCH bytes of str are valid
 *    (except for the last MIN_MATCH-1 bytes of the input file).
 */
#ifdef FASTEST
#define	INSERT_STRING(s, str, match_head) \
	(UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
	match_head = s->head[s->ins_h], \
	s->head[s->ins_h] = (Pos)(str))
#else
#define	INSERT_STRING(s, str, match_head) \
	(UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
	s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
	s->head[s->ins_h] = (Pos)(str))
#endif

/*
 * ===========================================================================
 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
 * prev[] will be initialized on the fly.
 */
#define	CLEAR_HASH(s) \
    s->head[s->hash_size-1] = NIL; \
    zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof (*s->head));

/* ========================================================================= */
int
deflateInit_(strm, level, version, stream_size)
    z_streamp strm;
    int level;
    const char *version;
    int stream_size;
{
	(void) deflate_copyright;
	return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
	    Z_DEFAULT_STRATEGY, version, stream_size);
	/* To do: ignore strm->next_in if we use it as window */
}

/* ========================================================================= */
int deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
    version, stream_size)
    z_streamp strm;
    int  level;
    int  method;
    int  windowBits;
    int  memLevel;
    int  strategy;
    const char *version;
    int stream_size;
{
	deflate_state *s;
	int noheader = 0;
	static const char *my_version = ZLIB_VERSION;

	ushf *overlay;
	/*
	 * We overlay pending_buf and d_buf+l_buf. This works since
	 * the average output size for (length, distance) codes is <=
	 * 24 bits.
	 */

	if (version == Z_NULL || version[0] != my_version[0] ||
	    stream_size != sizeof (z_stream)) {
		return (Z_VERSION_ERROR);
	}
	if (strm == Z_NULL)
		return (Z_STREAM_ERROR);

	strm->msg = Z_NULL;
#ifndef NO_ZCFUNCS
	if (strm->zalloc == Z_NULL) {
		strm->zalloc = zcalloc;
		strm->opaque = (voidpf)0;
	}
	if (strm->zfree == Z_NULL) strm->zfree = zcfree;
#endif

	if (level == Z_DEFAULT_COMPRESSION) level = 6;
#ifdef FASTEST
	level = 1;
#endif

	if (windowBits < 0) { /* undocumented feature: suppress zlib header */
		noheader = 1;
		windowBits = -windowBits;
	}
	if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
	    windowBits <= 8 || windowBits > 15 || level < 0 || level > 9 ||
	    strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
		return (Z_STREAM_ERROR);
	}
	s = (deflate_state *) ZALLOC(strm, 1, sizeof (deflate_state));
	if (s == Z_NULL)
		return (Z_MEM_ERROR);
	strm->state = (struct internal_state FAR *)s;
	s->strm = strm;

	s->noheader = noheader;
	s->w_bits = windowBits;
	s->w_size = 1 << s->w_bits;
	s->w_mask = s->w_size - 1;

	s->hash_bits = memLevel + 7;
	s->hash_size = 1 << s->hash_bits;
	s->hash_mask = s->hash_size - 1;
	s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);

	s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof (Byte));
	s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof (Pos));
	s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof (Pos));

	s->lit_bufsize = 1 << (memLevel + 6);	/* 16K elements by default */

	overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof (ush)+2);
	s->pending_buf = (uchf *) overlay;
	s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof (ush)+2L);

	if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
	    s->pending_buf == Z_NULL) {
		strm->msg = ERR_MSG(Z_MEM_ERROR);
		s->status = INIT_STATE;
		(void) deflateEnd(strm);
		return (Z_MEM_ERROR);
	}
	s->d_buf = overlay + s->lit_bufsize/sizeof (ush);
	s->l_buf = s->pending_buf + (1+sizeof (ush))*s->lit_bufsize;

	s->level = level;
	s->strategy = strategy;
	s->method = (Byte)method;

	return (deflateReset(strm));
}

/* ========================================================================= */
int
deflateSetDictionary(strm, dictionary, dictLength)
    z_streamp strm;
    const Bytef *dictionary;
    uInt  dictLength;
{
	deflate_state *s;
	uInt length = dictLength;
	uInt n;
	IPos hash_head = 0;

	if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
		return (Z_STREAM_ERROR);

	s = (deflate_state *) strm->state;
	if (s->status != INIT_STATE)
		return (Z_STREAM_ERROR);

	strm->adler = adler32(strm->adler, dictionary, dictLength);

	if (length < MIN_MATCH)
		return (Z_OK);
	if (length > MAX_DIST(s)) {
		length = MAX_DIST(s);
#ifndef USE_DICT_HEAD
		/* use the tail of the dictionary */
		dictionary += dictLength - length;
#endif
	}
	Assert(length <= s->window_size, "dict copy");
	zmemcpy(s->window, dictionary, length);
	s->strstart = length;
	s->block_start = (long)length;

	/*
	 * Insert all strings in the hash table (except for the last
	 * two bytes).  s->lookahead stays null, so s->ins_h will be
	 * recomputed at the next call of fill_window.
	 */
	s->ins_h = s->window[0];
	UPDATE_HASH(s, s->ins_h, s->window[1]);
	for (n = 0; n <= length - MIN_MATCH; n++) {
		INSERT_STRING(s, n, hash_head);
	}
	if (hash_head) hash_head = 0;	/* to make compiler happy */
	return (Z_OK);
}

/* ========================================================================= */
int
deflateReset(strm)
    z_streamp strm;
{
	deflate_state *s;

	if (strm == Z_NULL || strm->state == Z_NULL ||
	    strm->zalloc == Z_NULL || strm->zfree == Z_NULL)
		return (Z_STREAM_ERROR);

	strm->total_in = strm->total_out = 0;
	/* use zfree if we ever allocate msg dynamically */
	strm->msg = Z_NULL;
	strm->data_type = Z_UNKNOWN;

	s = (deflate_state *)strm->state;
	s->pending = 0;
	s->pending_out = s->pending_buf;

	if (s->noheader < 0) {
		/* was set to -1 by deflate(..., Z_FINISH); */
		s->noheader = 0;
	}
	s->status = s->noheader ? BUSY_STATE : INIT_STATE;
	strm->adler = 1;
	s->last_flush = Z_NO_FLUSH;

	_tr_init(s);
	lm_init(s);

	return (Z_OK);
}

/* ========================================================================= */
int
deflateParams(strm, level, strategy)
    z_streamp strm;
    int level;
    int strategy;
{
	deflate_state *s;
	compress_func func;
	int err = Z_OK;

	if (strm == Z_NULL || strm->state == Z_NULL)
		return (Z_STREAM_ERROR);
	s = (deflate_state *) strm->state;

	if (level == Z_DEFAULT_COMPRESSION) {
		level = 6;
	}
	if (level < 0 || level > 9 || strategy < 0 ||
	    strategy > Z_HUFFMAN_ONLY) {
		return (Z_STREAM_ERROR);
	}
	func = configuration_table[s->level].func;

	if (func != configuration_table[level].func && strm->total_in != 0) {
		/* Flush the last buffer: */
		err = deflate(strm, Z_PARTIAL_FLUSH);
	}
	if (s->level != level) {
		s->level = level;
		s->max_lazy_match   = configuration_table[level].max_lazy;
		s->good_match	= configuration_table[level].good_length;
		s->nice_match	= configuration_table[level].nice_length;
		s->max_chain_length = configuration_table[level].max_chain;
	}
	s->strategy = strategy;
	return (err);
}

/*
 * =========================================================================
 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
 * IN assertion: the stream state is correct and there is enough room in
 * pending_buf.
 */
local void
putShortMSB(s, b)
    deflate_state *s;
    uInt b;
{
	put_byte(s, (Byte)(b >> 8));
	put_byte(s, (Byte)(b & 0xff));
}

/*
 * =========================================================================
 * Flush as much pending output as possible. All deflate() output goes
 * through this function so some applications may wish to modify it
 * to avoid allocating a large strm->next_out buffer and copying into it.
 * (See also read_buf()).
 */
local void
flush_pending(strm)
    z_streamp strm;
{
	deflate_state *s = (deflate_state *) strm->state;
	unsigned len = s->pending;

	if (len > strm->avail_out) len = strm->avail_out;
	if (len == 0)
		return;

	if (strm->next_out != Z_NULL) {		/* PPP */
		zmemcpy(strm->next_out, s->pending_out, len);
		strm->next_out += len;
	}					/* PPP */
	s->pending_out += len;
	strm->total_out += len;
	strm->avail_out  -= len;
	s->pending -= len;
	if (s->pending == 0) {
		s->pending_out = s->pending_buf;
	}
}

/* ========================================================================= */
int
deflate(strm, flush)
    z_streamp strm;
    int flush;
{
	int old_flush;	/* value of flush param for previous deflate call */
	deflate_state *s;

	if (strm == Z_NULL || strm->state == Z_NULL ||
	    flush > Z_FINISH || flush < 0) {
		return (Z_STREAM_ERROR);
	}
	s = (deflate_state *) strm->state;

	if (/* strm->next_out == Z_NULL || --- we allow null --- PPP */
		(strm->next_in == Z_NULL && strm->avail_in != 0) ||
	    (s->status == FINISH_STATE && flush != Z_FINISH)) {
		ERR_RETURN(strm, Z_STREAM_ERROR);
	}
	if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);

	s->strm = strm;	/* just in case */
	old_flush = s->last_flush;
	s->last_flush = flush;

	/* Write the zlib header */
	if (s->status == INIT_STATE) {

		uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
		uInt level_flags = (s->level-1) >> 1;

		if (level_flags > 3) level_flags = 3;
		header |= (level_flags << 6);
		if (s->strstart != 0) header |= PRESET_DICT;
		header += 31 - (header % 31);

		s->status = BUSY_STATE;
		putShortMSB(s, header);

		/* Save the adler32 of the preset dictionary: */
		if (s->strstart != 0) {
			putShortMSB(s, (uInt)(strm->adler >> 16));
			putShortMSB(s, (uInt)(strm->adler & 0xffff));
		}
		strm->adler = 1L;
	}

	/* Flush as much pending output as possible */
	if (s->pending != 0) {
		flush_pending(strm);
		if (strm->avail_out == 0) {
			/*
			 * Since avail_out is 0, deflate will be
			 * called again with more output space, but
			 * possibly with both pending and avail_in
			 * equal to zero. There won't be anything to
			 * do, but this is not an error situation so
			 * make sure we return OK instead of BUF_ERROR
			 * at next call of deflate:
			 */
			s->last_flush = -1;
			return (Z_OK);
		}

		/*
		 * Make sure there is something to do and avoid
		 * duplicate consecutive flushes. For repeated and
		 * useless calls with Z_FINISH, we keep returning
		 * Z_STREAM_END instead of Z_BUFF_ERROR.
		 */
	} else if (strm->avail_in == 0 && flush <= old_flush &&
	    flush != Z_FINISH) {
		ERR_RETURN(strm, Z_BUF_ERROR);
	}

	/* User must not provide more input after the first FINISH: */
	if (s->status == FINISH_STATE && strm->avail_in != 0) {
		ERR_RETURN(strm, Z_BUF_ERROR);
	}

	/* Start a new block or continue the current one. */
	if (strm->avail_in != 0 || s->lookahead != 0 ||
	    (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
		block_state bstate;

		bstate = (*(configuration_table[s->level].func))(s, flush);

		if (bstate == finish_started || bstate == finish_done) {
			s->status = FINISH_STATE;
		}
		if (bstate == need_more || bstate == finish_started) {
			if (strm->avail_out == 0) {
				/* avoid BUF_ERROR next call, see above */
				s->last_flush = -1;
			}
			return (Z_OK);
			/*
			 * If flush != Z_NO_FLUSH && avail_out == 0,
			 * the next call of deflate should use the
			 * same flush parameter to make sure that the
			 * flush is complete. So we don't have to
			 * output an empty block here, this will be
			 * done at next call. This also ensures that
			 * for a very small output buffer, we emit at
			 * most one empty block.
			 */
		}
		if (bstate == block_done) {
			if (flush == Z_PARTIAL_FLUSH) {
				_tr_align(s);
			} else if (flush == Z_PACKET_FLUSH) {	/* PPP */
				/*
				 * Output just the 3-bit `stored'
				 * block type value, but not a zero
				 * length.  Added for PPP.
				 */
				_tr_stored_type_only(s);	/* PPP */
			} else { /* FULL_FLUSH or SYNC_FLUSH */
				_tr_stored_block(s, (char *)0, 0L, 0);
				/*
				 * For a full flush, this empty block
				 * will be recognized as a special
				 * marker by inflate_sync().
				 */
				if (flush == Z_FULL_FLUSH) {
					CLEAR_HASH(s);	/* forget history */
				}
			}
			flush_pending(strm);
			if (strm->avail_out == 0) {
				/* avoid BUF_ERROR at next call, see above */
				s->last_flush = -1;
				return (Z_OK);
			}
		}
	}
	Assert(strm->avail_out > 0, "bug2");

	if (flush != Z_FINISH)
		return (Z_OK);
	if (s->noheader)
		return (Z_STREAM_END);

	/* Write the zlib trailer (adler32) */
	putShortMSB(s, (uInt)(strm->adler >> 16));
	putShortMSB(s, (uInt)(strm->adler & 0xffff));
	flush_pending(strm);
	/*
	 * If avail_out is zero, the application will call deflate
	 * again to flush the rest.
	 */
	s->noheader = -1;	/* write the trailer only once! */
	return (s->pending != 0 ? Z_OK : Z_STREAM_END);
}

/* ========================================================================= */
int
deflateEnd(strm)
    z_streamp strm;
{
	int status;
	deflate_state *s;

	if (strm == Z_NULL || strm->state == Z_NULL)
		return (Z_STREAM_ERROR);
	s = (deflate_state *) strm->state;

	status = s->status;
	if (status != INIT_STATE && status != BUSY_STATE &&
	    status != FINISH_STATE) {
		return (Z_STREAM_ERROR);
	}

	/* Deallocate in reverse order of allocations: */
	TRY_FREE(strm, s->pending_buf);
	TRY_FREE(strm, s->head);
	TRY_FREE(strm, s->prev);
	TRY_FREE(strm, s->window);

	ZFREE(strm, s);
	strm->state = Z_NULL;

	return (status == BUSY_STATE ? Z_DATA_ERROR : Z_OK);
}

/*
 * =========================================================================
 * Copy the source state to the destination state.
 * To simplify the source, this is not supported for 16-bit MSDOS (which
 * doesn't have enough memory anyway to duplicate compression states).
 */
int
deflateCopy(dest, source)
    z_streamp dest;
    z_streamp source;
{
#ifdef MAXSEG_64K
	return (Z_STREAM_ERROR);
#else
	deflate_state *ds;
	deflate_state *ss;
	ushf *overlay;

	if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
		return (Z_STREAM_ERROR);
	ss = (deflate_state *) source->state;

	zmemcpy(dest, source, sizeof (*dest));

	ds = (deflate_state *) ZALLOC(dest, 1, sizeof (deflate_state));
	if (ds == Z_NULL)
		return (Z_MEM_ERROR);
	dest->state = (struct internal_state FAR *) ds;
	zmemcpy(ds, ss, sizeof (*ds));
	ds->strm = dest;

	ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof (Byte));
	ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof (Pos));
	ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof (Pos));
	overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof (ush)+2);
	ds->pending_buf = (uchf *) overlay;

	if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
	    ds->pending_buf == Z_NULL) {
		ds->status = INIT_STATE;
		(void) deflateEnd(dest);
		return (Z_MEM_ERROR);
	}
	/* following zmemcpy doesn't work for 16-bit MSDOS */
	zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof (Byte));
	zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof (Pos));
	zmemcpy(ds->head, ss->head, ds->hash_size * sizeof (Pos));
	zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);

	ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
	ds->d_buf = overlay + ds->lit_bufsize/sizeof (ush);
	ds->l_buf = ds->pending_buf + (1+sizeof (ush))*ds->lit_bufsize;

	ds->l_desc.dyn_tree = ds->dyn_ltree;
	ds->d_desc.dyn_tree = ds->dyn_dtree;
	ds->bl_desc.dyn_tree = ds->bl_tree;

	return (Z_OK);
#endif
}

/*
 * ===========================================================================
 * Return the number of bytes of output which are immediately available
 * for output from the decompressor.		---PPP---
 */
int
deflateOutputPending(strm)
    z_streamp strm;
{
	if (strm == Z_NULL || strm->state == Z_NULL)
		return (0);

	return (((deflate_state *)(strm->state))->pending);
}

/*
 * ===========================================================================
 * Read a new buffer from the current input stream, update the adler32
 * and total number of bytes read.  All deflate() input goes through
 * this function so some applications may wish to modify it to avoid
 * allocating a large strm->next_in buffer and copying from it.
 * (See also flush_pending()).
 */
local int
read_buf(strm, buf, size)
    z_streamp strm;
    Bytef *buf;
    unsigned size;
{
	unsigned len = strm->avail_in;

	if (len > size) len = size;
	if (len == 0)
		return (0);

	strm->avail_in  -= len;

	if (!((deflate_state *)(strm->state))->noheader) {
		strm->adler = adler32(strm->adler, strm->next_in, len);
	}
	zmemcpy(buf, strm->next_in, len);
	strm->next_in  += len;
	strm->total_in += len;

	return ((int)len);
}

/*
 * ===========================================================================
 * Initialize the "longest match" routines for a new zlib stream
 */
local void
lm_init(s)
    deflate_state *s;
{
	s->window_size = (ulg)2L*s->w_size;

	CLEAR_HASH(s);

	/* Set the default configuration parameters: */
	s->max_lazy_match   = configuration_table[s->level].max_lazy;
	s->good_match	= configuration_table[s->level].good_length;
	s->nice_match	= configuration_table[s->level].nice_length;
	s->max_chain_length = configuration_table[s->level].max_chain;

	s->strstart = 0;
	s->block_start = 0L;
	s->lookahead = 0;
	s->match_length = s->prev_length = MIN_MATCH-1;
	s->match_available = 0;
	s->ins_h = 0;
#ifdef ASMV
	match_init();	/* initialize the asm code */
#endif
}

/*
 * ===========================================================================
 * Set match_start to the longest match starting at the given string and
 * return its length. Matches shorter or equal to prev_length are discarded,
 * in which case the result is equal to prev_length and match_start is
 * garbage.
 * IN assertions: cur_match is the head of the hash chain for the current
 *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
 * OUT assertion: the match length is not greater than s->lookahead.
 */
#ifndef ASMV
/*
 * For 80x86 and 680x0, an optimized version will be provided in
 * match.asm or match.S. The code will be functionally equivalent.
 */
#ifndef FASTEST
local uInt
longest_match(s, cur_match)
    deflate_state *s;
    IPos cur_match;	/* current match */
{
	/* max hash chain length */
	unsigned chain_length = s->max_chain_length;
	register Bytef *scan = s->window + s->strstart;	/* current string */
	register Bytef *match;	/* matched string */
	register int len;	/* length of current match */
	int best_len = s->prev_length;	/* best match length so far */
	int nice_match = s->nice_match;	/* stop if match long enough */
	IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
	    s->strstart - (IPos)MAX_DIST(s) : NIL;
	/*
	 * Stop when cur_match becomes <= limit. To simplify the code,
	 * we prevent matches with the string of window index 0.
	 */
	Posf *prev = s->prev;
	uInt wmask = s->w_mask;

#ifdef UNALIGNED_OK
	/*
	 * Compare two bytes at a time. Note: this is not always
	 * beneficial.  Try with and without -DUNALIGNED_OK to check.
	 */
	register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
	register ush scan_start = *(ushf*)scan;
	register ush scan_end   = *(ushf*)(scan+best_len-1);
#else
	register Bytef *strend = s->window + s->strstart + MAX_MATCH;
	register Byte scan_end1  = scan[best_len-1];
	register Byte scan_end   = scan[best_len];
#endif

	/*
	 * The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2
	 * multiple of 16.  It is easy to get rid of this optimization
	 * if necessary.
	 */
	Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");

	/* Do not waste too much time if we already have a good match: */
	if (s->prev_length >= s->good_match) {
		chain_length >>= 2;
	}
	/*
	 * Do not look for matches beyond the end of the input. This
	 * is necessary to make deflate deterministic.
	 */
	if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;

	Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD,
	    "need lookahead");

	do {
		Assert(cur_match <= s->strstart, "no future");
		match = s->window + cur_match;

		/*
		 * Skip to next match if the match length cannot
		 * increase or if the match length is less than 2:
		 */
#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
		/*
		 * This code assumes sizeof (unsigned short) == 2. Do
		 * not use UNALIGNED_OK if your compiler uses a
		 * different size.
		 */
		if (*(ushf*)(match+best_len-1) != scan_end ||
		    *(ushf*)match != scan_start) continue;

		/*
		 * It is not necessary to compare scan[2] and match[2]
		 * since they are always equal when the other bytes
		 * match, given that the hash keys are equal and that
		 * HASH_BITS >= 8. Compare 2 bytes at a time at
		 * strstart+3, +5, ... up to strstart+257. We check
		 * for insufficient lookahead only every 4th
		 * comparison; the 128th check will be made at
		 * strstart+257. If MAX_MATCH-2 is not a multiple of
		 * 8, it is necessary to put more guard bytes at the
		 * end of the window, or to check more often for
		 * insufficient lookahead.
		 */
		Assert(scan[2] == match[2], "scan[2]?");
		scan++, match++;
		do {
		} while (*(ushf *)(scan += 2) == *(ushf *)(match += 2) &&
		    *(ushf *)(scan += 2) == *(ushf *)(match += 2) &&
		    *(ushf *)(scan += 2) == *(ushf *)(match += 2) &&
		    *(ushf *)(scan += 2) == *(ushf *)(match += 2) &&
		    scan < strend);
		/* The funny "do {}" generates better code on most compilers */

		/* Here, scan <= window+strstart+257 */
		Assert(scan <= s->window+(unsigned)(s->window_size-1),
		    "wild scan");
		if (*scan == *match) scan++;

		len = (MAX_MATCH - 1) - (int)(strend-scan);
		scan = strend - (MAX_MATCH-1);

#else /* UNALIGNED_OK */

		if (match[best_len]	!= scan_end	||
		    match[best_len-1]	!= scan_end1	||
		    *match		!= *scan	||
		    *++match		!= scan[1])
			continue;

		/*
		 * The check at best_len-1 can be removed because it
		 * will be made again later. (This heuristic is not
		 * always a win.)  It is not necessary to compare
		 * scan[2] and match[2] since they are always equal
		 * when the other bytes match, given that the hash
		 * keys are equal and that HASH_BITS >= 8.
		 */
		scan += 2, match++;
		Assert(*scan == *match, "match[2]?");

		/*
		 * We check for insufficient lookahead only every 8th
		 * comparison; the 256th check will be made at
		 * strstart+258.
		 */
		do {
		} while (*++scan == *++match && *++scan == *++match &&
		    *++scan == *++match && *++scan == *++match &&
		    *++scan == *++match && *++scan == *++match &&
		    *++scan == *++match && *++scan == *++match &&
		    scan < strend);

		Assert(scan <= s->window+(unsigned)(s->window_size-1),
		    "wild scan");

		len = MAX_MATCH - (int)(strend - scan);
		scan = strend - MAX_MATCH;

#endif /* UNALIGNED_OK */

		if (len > best_len) {
			s->match_start = cur_match;
			best_len = len;
			if (len >= nice_match) break;
#ifdef UNALIGNED_OK
			scan_end = *(ushf*)(scan+best_len-1);
#else
			scan_end1  = scan[best_len-1];
			scan_end   = scan[best_len];
#endif
		}
	} while ((cur_match = prev[cur_match & wmask]) > limit &&
	    --chain_length != 0);

	if ((uInt)best_len <= s->lookahead)
		return (best_len);
	return (s->lookahead);
}
#else /* FASTEST */
/*
 * ---------------------------------------------------------------------------
 * Optimized version for level == 1 only
 */
local uInt
longest_match(s, cur_match)
deflate_state *s;
IPos cur_match;		/* current match */
{
	register Bytef *scan = s->window + s->strstart; /* current string */
	register Bytef *match;		/* matched string */
	register int len;			/* length of current match */
	register Bytef *strend = s->window + s->strstart + MAX_MATCH;

	/*
	 * The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2
	 * multiple of 16.  It is easy to get rid of this optimization
	 * if necessary.
	 */
	Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");

	Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD,
	    "need lookahead");

	Assert(cur_match <= s->strstart, "no future");

	match = s->window + cur_match;

	/* Return failure if the match length is less than 2: */
	if (match[0] != scan[0] || match[1] != scan[1])
		return (MIN_MATCH-1);

	/*
	 * The check at best_len-1 can be removed because it will be
	 * made again later. (This heuristic is not always a win.)  It
	 * is not necessary to compare scan[2] and match[2] since they
	 * are always equal when the other bytes match, given that the
	 * hash keys are equal and that HASH_BITS >= 8.
	 */
	scan += 2, match += 2;
	Assert(*scan == *match, "match[2]?");

	/*
	 * We check for insufficient lookahead only every 8th comparison;
	 * the 256th check will be made at strstart+258.
	 */
	do {
	} while (*++scan == *++match && *++scan == *++match &&
	    *++scan == *++match && *++scan == *++match &&
	    *++scan == *++match && *++scan == *++match &&
	    *++scan == *++match && *++scan == *++match &&
	    scan < strend);

	Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");

	len = MAX_MATCH - (int)(strend - scan);

	if (len < MIN_MATCH)
		return (MIN_MATCH - 1);

	s->match_start = cur_match;
	return (len <= s->lookahead ? len : s->lookahead);
}
#endif /* FASTEST */
#endif /* ASMV */

#ifdef DEBUG_ZLIB
/*
 * ===========================================================================
 * Check that the match at match_start is indeed a match.
 */
local void
check_match(s, start, match, length)
    deflate_state *s;
    IPos start, match;
    int length;
{
	/* check that the match is indeed a match */
	if (zmemcmp(s->window + match, s->window + start, length) != EQUAL) {
		fprintf(stderr, " start %u, match %u, length %d\n",
		    start, match, length);
		do {
			fprintf(stderr, "%c%c", s->window[match++],
			    s->window[start++]);
		} while (--length != 0);
		z_error("invalid match");
	}
	if (z_verbose > 1) {
		fprintf(stderr, "\\[%d,%d]", start-match, length);
		do { putc(s->window[start++], stderr); } while (--length != 0);
	}
}
#else
#define	check_match(s, start, match, length)
#endif

/*
 * ===========================================================================
 * Fill the window when the lookahead becomes insufficient.
 * Updates strstart and lookahead.
 *
 * IN assertion: lookahead < MIN_LOOKAHEAD
 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
 *    At least one byte has been read, or avail_in == 0; reads are
 *    performed for at least two bytes (required for the zip translate_eol
 *    option -- not supported here).
 */
local void
fill_window(s)
    deflate_state *s;
{
	register unsigned n, m;
	register Posf *p;
	unsigned more;	/* Amount of free space at the end of the window. */
	uInt wsize = s->w_size;

	do {
		more = (unsigned)(s->window_size -(ulg)s->lookahead -
		    (ulg)s->strstart);

		/* Deal with !@#$% 64K limit: */
		if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
			more = wsize;

		} else if (more == (unsigned)(-1)) {
			/*
			 * Very unlikely, but possible on 16 bit
			 * machine if strstart == 0 and lookahead == 1
			 * (input done one byte at time)
			 */
			more--;

			/*
			 * If the window is almost full and there is
			 * insufficient lookahead, move the upper half
			 * to the lower one to make room in the upper
			 * half.
			 */
		} else if (s->strstart >= wsize+MAX_DIST(s)) {

			Assert(wsize+wsize <= s->window_size, "wsize*2");
			zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
			s->match_start -= wsize;
			/* we now have strstart >= MAX_DIST */
			s->strstart    -= wsize;
			s->block_start -= (long)wsize;

			/*
			 * Slide the hash table (could be avoided with
			 * 32 bit values at the expense of memory
			 * usage). We slide even when level == 0 to
			 * keep the hash table consistent if we switch
			 * back to level > 0 later. (Using level 0
			 * permanently is not an optimal usage of
			 * zlib, so we don't care about this
			 * pathological case.)
			 */
			n = s->hash_size;
			p = &s->head[n];
			do {
				m = *--p;
				*p = (Pos)(m >= wsize ? m-wsize : NIL);
			} while (--n);

			n = wsize;
#ifndef FASTEST
			p = &s->prev[n];
			do {
				m = *--p;
				*p = (Pos)(m >= wsize ? m-wsize : NIL);
				/*
				 * If n is not on any hash chain,
				 * prev[n] is garbage but its value
				 * will never be used.
				 */
			} while (--n);
#endif
			more += wsize;
		}
		if (s->strm->avail_in == 0)
			return;

		/*
		 * If there was no sliding:
		 *    strstart <= WSIZE+MAX_DIST-1 &&
		 *	lookahead <= MIN_LOOKAHEAD - 1 &&
		 *    more == window_size - lookahead - strstart
		 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE +
		 *	MAX_DIST-1)
		 * => more >= window_size - 2*WSIZE + 2
		 * In the BIG_MEM or MMAP case (not yet supported),
		 *   window_size == input_size + MIN_LOOKAHEAD  &&
		 *   strstart + s->lookahead <= input_size =>
		 *	more >= MIN_LOOKAHEAD.
		 * Otherwise, window_size == 2*WSIZE so more >= 2.
		 * If there was sliding, more >= WSIZE. So in all cases,
		 * more >= 2.
		 */
		Assert(more >= 2, "more < 2");
		Assert(s->strstart + s->lookahead + more <= s->window_size,
		    "read too much");

		n = read_buf(s->strm, s->window + s->strstart + s->lookahead,
		    more);
		s->lookahead += n;

		/* Initialize the hash value now that we have some input: */
		if (s->lookahead >= MIN_MATCH) {
			s->ins_h = s->window[s->strstart];
			UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
#if MIN_MATCH != 3
			Call UPDATE_HASH() MIN_MATCH-3 more times
#endif
			    }
		/*
		 * If the whole input has less than MIN_MATCH bytes,
		 * ins_h is garbage, but this is not important since
		 * only literal bytes will be emitted.
		 */

	} while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
}

/*
 * ===========================================================================
 * Flush the current block, with given end-of-file flag.
 * IN assertion: strstart is set to the end of the current match.
 */
#define	FLUSH_BLOCK_ONLY(s, eof) { \
	_tr_flush_block(s, (s->block_start >= 0L ? \
		(charf *)&s->window[(unsigned)s->block_start] : \
		(charf *)Z_NULL), \
		(ulg)((long)s->strstart - s->block_start), \
		(eof)); \
	s->block_start = s->strstart; \
	flush_pending(s->strm); \
	Tracev((stderr, "[FLUSH]")); \
}

/* Same but force premature exit if necessary. */
#define	FLUSH_BLOCK(s, eof) { \
	FLUSH_BLOCK_ONLY(s, eof); \
	if (s->strm->avail_out == 0) \
		return ((eof) ? finish_started : need_more); \
}

/*
 * ===========================================================================
 * Copy without compression as much as possible from the input stream, return
 * the current block state.
 * This function does not insert new strings in the dictionary since
 * uncompressible data is probably not useful. This function is used
 * only for the level=0 compression option.
 * NOTE: this function should be optimized to avoid extra copying from
 * window to pending_buf.
 */
local block_state
deflate_stored(s, flush)
    deflate_state *s;
    int flush;
{
	/*
	 * Stored blocks are limited to 0xffff bytes, pending_buf is
	 * limited to pending_buf_size, and each stored block has a 5
	 * byte header:
	 */
	ulg max_block_size = 0xffff;
	ulg max_start;

	if (max_block_size > s->pending_buf_size - 5) {
		max_block_size = s->pending_buf_size - 5;
	}

	/* Copy as much as possible from input to output: */
	for (;;) {
		/* Fill the window as much as possible: */
		if (s->lookahead <= 1) {

			Assert(s->strstart < s->w_size+MAX_DIST(s) ||
			    s->block_start >= (long)s->w_size,
			    "slide too late");

			fill_window(s);
			if (s->lookahead == 0 && flush == Z_NO_FLUSH)
				return (need_more);

			if (s->lookahead == 0)
				break;	/* flush the current block */
		}
		Assert(s->block_start >= 0L, "block gone");

		s->strstart += s->lookahead;
		s->lookahead = 0;

		/* Emit a stored block if pending_buf will be full: */
		max_start = s->block_start + max_block_size;
		if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
			/*
			 * strstart == 0 is possible when wraparound
			 * on 16-bit machine
			 */
			s->lookahead = (uInt)(s->strstart - max_start);
			s->strstart = (uInt)max_start;
			FLUSH_BLOCK(s, 0);
		}
		/*
		 * Flush if we may have to slide, otherwise
		 * block_start may become negative and the data will
		 * be gone:
		 */
		if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
			FLUSH_BLOCK(s, 0);
		}
	}
	FLUSH_BLOCK(s, flush == Z_FINISH);
	return (flush == Z_FINISH ? finish_done : block_done);
}

/*
 * ===========================================================================
 * Compress as much as possible from the input stream, return the current
 * block state.
 * This function does not perform lazy evaluation of matches and inserts
 * new strings in the dictionary only for unmatched strings or for short
 * matches. It is used only for the fast compression options.
 */
local block_state
deflate_fast(s, flush)
    deflate_state *s;
    int flush;
{
	IPos hash_head = NIL;	/* head of the hash chain */
	int bflush;	/* set if current block must be flushed */

	for (;;) {
		/*
		 * Make sure that we always have enough lookahead,
		 * except at the end of the input file. We need
		 * MAX_MATCH bytes for the next match, plus MIN_MATCH
		 * bytes to insert the string following the next
		 * match.
		 */
		if (s->lookahead < MIN_LOOKAHEAD) {
			fill_window(s);
			if (s->lookahead < MIN_LOOKAHEAD &&
			    flush == Z_NO_FLUSH) {
				return (need_more);
			}
			if (s->lookahead == 0)
				break;	/* flush the current block */
		}

		/*
		 * Insert the string window[strstart .. strstart+2] in
		 * the dictionary, and set hash_head to the head of
		 * the hash chain:
		 */
		if (s->lookahead >= MIN_MATCH) {
			INSERT_STRING(s, s->strstart, hash_head);
		}

		/*
		 * Find the longest match, discarding those <=
		 * prev_length.  At this point we have always
		 * match_length < MIN_MATCH
		 */
		if (hash_head != NIL && s->strstart - hash_head <=
		    MAX_DIST(s)) {
			/*
			 * To simplify the code, we prevent matches
			 * with the string of window index 0 (in
			 * particular we have to avoid a match of the
			 * string with itself at the start of the
			 * input file).
			 */
			if (s->strategy != Z_HUFFMAN_ONLY) {
				s->match_length = longest_match(s, hash_head);
			}
			/* longest_match() sets match_start */
		}
		if (s->match_length >= MIN_MATCH) {
			check_match(s, s->strstart, s->match_start,
			    s->match_length);

			_tr_tally_dist(s, s->strstart - s->match_start,
			    s->match_length - MIN_MATCH, bflush);

			s->lookahead -= s->match_length;

			/*
			 * Insert new strings in the hash table only
			 * if the match length is not too large. This
			 * saves time but degrades compression.
			 */
#ifndef FASTEST
			if (s->match_length <= s->max_insert_length &&
			    s->lookahead >= MIN_MATCH) {
				/* string at strstart already in hash table */
				s->match_length--;
				do {
					s->strstart++;
					INSERT_STRING(s, s->strstart,
					    hash_head);
					/*
					 * strstart never exceeds
					 * WSIZE-MAX_MATCH, so there
					 * are always MIN_MATCH bytes
					 * ahead.
					 */
				} while (--s->match_length != 0);
				s->strstart++;
			} else
#endif
			{
				s->strstart += s->match_length;
				s->match_length = 0;
				s->ins_h = s->window[s->strstart];
				UPDATE_HASH(s, s->ins_h,
				    s->window[s->strstart+1]);
#if MIN_MATCH != 3
				Call UPDATE_HASH() MIN_MATCH-3 more times
#endif
				/*
				 * If lookahead < MIN_MATCH, ins_h is
				 * garbage, but it does not matter
				 * since it will be recomputed at next
				 * deflate call.
				 */
			}
		} else {
			/* No match, output a literal byte */
			Tracevv((stderr, "%c", s->window[s->strstart]));
			_tr_tally_lit(s, s->window[s->strstart], bflush);
			s->lookahead--;
			s->strstart++;
		}
		if (bflush) FLUSH_BLOCK(s, 0);
	}
	FLUSH_BLOCK(s, flush == Z_FINISH);
	return (flush == Z_FINISH ? finish_done : block_done);
}

/*
 * ===========================================================================
 * Same as above, but achieves better compression. We use a lazy
 * evaluation for matches: a match is finally adopted only if there is
 * no better match at the next window position.
 */
local block_state
deflate_slow(s, flush)
    deflate_state *s;
    int flush;
{
	IPos hash_head = NIL;	/* head of hash chain */
	int bflush;	/* set if current block must be flushed */

	/* Process the input block. */
	for (;;) {
		/*
		 * Make sure that we always have enough lookahead,
		 * except at the end of the input file. We need
		 * MAX_MATCH bytes for the next match, plus MIN_MATCH
		 * bytes to insert the string following the next
		 * match.
		 */
		if (s->lookahead < MIN_LOOKAHEAD) {
			fill_window(s);
			if (s->lookahead < MIN_LOOKAHEAD &&
			    flush == Z_NO_FLUSH) {
				return (need_more);
			}
			/* flush the current block */
			if (s->lookahead == 0)
				break;
		}

		/*
		 * Insert the string window[strstart .. strstart+2] in
		 * the dictionary, and set hash_head to the head of
		 * the hash chain:
		 */
		if (s->lookahead >= MIN_MATCH) {
			INSERT_STRING(s, s->strstart, hash_head);
		}

		/*
		 * Find the longest match, discarding those <=
		 * prev_length.
		 */
		s->prev_length = s->match_length;
		s->prev_match = s->match_start;
		s->match_length = MIN_MATCH-1;

		if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
		    s->strstart - hash_head <= MAX_DIST(s)) {
			/*
			 * To simplify the code, we prevent matches
			 * with the string of window index 0 (in
			 * particular we have to avoid a match of the
			 * string with itself at the start of the
			 * input file).
			 */
			if (s->strategy != Z_HUFFMAN_ONLY) {
				s->match_length = longest_match(s, hash_head);
			}
			/* longest_match() sets match_start */

			if (s->match_length <= 5 &&
			    (s->strategy == Z_FILTERED ||
				(s->match_length == MIN_MATCH &&
				    s->strstart - s->match_start > TOO_FAR))) {

				/*
				 * If prev_match is also MIN_MATCH,
				 * match_start is garbage but we will
				 * ignore the current match anyway.
				 */
				s->match_length = MIN_MATCH-1;
			}
		}
		/*
		 * If there was a match at the previous step and the
		 * current match is not better, output the previous
		 * match:
		 */
		if (s->prev_length >= MIN_MATCH &&
		    s->match_length <= s->prev_length) {
			uInt max_insert = s->strstart + s->lookahead -
			    MIN_MATCH;
			/* Do not insert strings in hash table beyond this. */

			check_match(s, s->strstart-1, s->prev_match,
			    s->prev_length);

			_tr_tally_dist(s, s->strstart -1 - s->prev_match,
			    s->prev_length - MIN_MATCH, bflush);

			/*
			 * Insert in hash table all strings up to the
			 * end of the match.  strstart-1 and strstart
			 * are already inserted. If there is not
			 * enough lookahead, the last two strings are
			 * not inserted in the hash table.
			 */
			s->lookahead -= s->prev_length-1;
			s->prev_length -= 2;
			do {
				if (++s->strstart <= max_insert) {
					INSERT_STRING(s, s->strstart,
					    hash_head);
				}
			} while (--s->prev_length != 0);
			s->match_available = 0;
			s->match_length = MIN_MATCH-1;
			s->strstart++;

			if (bflush) FLUSH_BLOCK(s, 0);

		} else if (s->match_available) {
			/*
			 * If there was no match at the previous
			 * position, output a single literal. If there
			 * was a match but the current match is
			 * longer, truncate the previous match to a
			 * single literal.
			 */
			Tracevv((stderr, "%c", s->window[s->strstart-1]));
			_tr_tally_lit(s, s->window[s->strstart-1], bflush);
			if (bflush) {
				FLUSH_BLOCK_ONLY(s, 0);
			}
			s->strstart++;
			s->lookahead--;
			if (s->strm->avail_out == 0)
				return (need_more);
		} else {
			/*
			 * There is no previous match to compare with,
			 * wait for the next step to decide.
			 */
			s->match_available = 1;
			s->strstart++;
			s->lookahead--;
		}
	}
	Assert(flush != Z_NO_FLUSH, "no flush?");
	if (s->match_available) {
		Tracevv((stderr, "%c", s->window[s->strstart-1]));
		_tr_tally_lit(s, s->window[s->strstart-1], bflush);
		s->match_available = 0;
	}
	FLUSH_BLOCK(s, flush == Z_FINISH);
	return (flush == Z_FINISH ? finish_done : block_done);
}
/* --- deflate.c */

/* +++ trees.c */
/*
 * trees.c -- output deflated data using Huffman coding
 * Copyright (C) 1995-1998 Jean-loup Gailly
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 *  ALGORITHM
 *
 *      The "deflation" process uses several Huffman trees. The more
 *      common source values are represented by shorter bit sequences.
 *
 *      Each code tree is stored in a compressed form which is itself
 * a Huffman encoding of the lengths of all the code strings (in
 * ascending order by source values).  The actual code strings are
 * reconstructed from the lengths in the inflate process, as described
 * in the deflate specification.
 *
 *  REFERENCES
 *
 *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
 *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
 *
 *      Storer, James A.
 *          Data Compression:  Methods and Theory, pp. 49-50.
 *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
 *
 *      Sedgewick, R.
 *          Algorithms, p290.
 *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
 */

/* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */

/* #include "deflate.h" */

#ifdef DEBUG_ZLIB
#include <ctype.h>
#endif

/*
 * ===========================================================================
 * Constants
 */

#define	MAX_BL_BITS 7
/* Bit length codes must not exceed MAX_BL_BITS bits */

#define	END_BLOCK 256
/* end of block literal code */

#define	REP_3_6		16
/* repeat previous bit length 3-6 times (2 bits of repeat count) */

#define	REPZ_3_10	17
/* repeat a zero length 3-10 times  (3 bits of repeat count) */

#define	REPZ_11_138	18
/* repeat a zero length 11-138 times  (7 bits of repeat count) */

/* extra bits for each length code */
local const int extra_lbits[LENGTH_CODES] = {
	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4,
	4, 4, 4, 5, 5, 5, 5, 0};

/* extra bits for each distance code */
local const int extra_dbits[D_CODES] = {
	0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9,
	9, 10, 10, 11, 11, 12, 12, 13, 13};

/* extra bits for each bit length code */
local const int extra_blbits[BL_CODES] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7};

local const uch bl_order[BL_CODES] = {
	16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};

/*
 * The lengths of the bit length codes are sent in order of decreasing
 * probability, to avoid transmitting the lengths for unused bit
 * length codes.
 */

#define	Buf_size (8 * 2*sizeof (char))
/*
 * Number of bits used within bi_buf. (bi_buf might be implemented on
 * more than 16 bits on some systems.)
 */

/*
 * ===========================================================================
 * Local data. These are initialized only once.
 */
#define	DIST_CODE_LEN  512 /* see definition of array dist_code below */

local ct_data static_ltree[L_CODES+2];
/*
 * The static literal tree. Since the bit lengths are imposed, there
 * is no need for the L_CODES extra codes used during heap
 * construction. However The codes 286 and 287 are needed to build a
 * canonical tree (see _tr_init below).
 */

local ct_data static_dtree[D_CODES];
/*
 * The static distance tree. (Actually a trivial tree since all codes
 * use 5 bits.)
 */

local uch _dist_code[512];
/*
 * distance codes. The first 256 values correspond to the distances 3
 * .. 258, the last 256 values correspond to the top 8 bits of the 15
 * bit distances.
 */

local uch _length_code[MAX_MATCH-MIN_MATCH+1];
/* length code for each normalized match length (0 == MIN_MATCH) */

local int base_length[LENGTH_CODES];
/* First normalized length for each code (0 = MIN_MATCH) */

local int base_dist[D_CODES];
/* First normalized distance for each code (0 = distance of 1) */

struct static_tree_desc_s {
	const ct_data *static_tree;	/* static tree or NULL */
	const intf    *extra_bits;	/* extra bits for each code or NULL */
	int	extra_base;	/* base index for extra_bits */
	int	elems;	/* max number of elements in the tree */
	int	max_length;	/* max bit length for the codes */
};

local static_tree_desc  static_l_desc = {
	static_ltree, extra_lbits, LITERALS+1,	L_CODES, MAX_BITS};

local static_tree_desc  static_d_desc = {
	static_dtree, extra_dbits, 0,		D_CODES, MAX_BITS};

local static_tree_desc  static_bl_desc = {
	(const ct_data *)0, extra_blbits, 0,		BL_CODES, MAX_BL_BITS};

/*
 * ===========================================================================
 * Local (static) routines in this file.
 */

local void tr_static_init OF((void));
local void init_block	OF((deflate_state *s));
local void pqdownheap	OF((deflate_state *s, ct_data *tree, int k));
local void gen_bitlen	OF((deflate_state *s, tree_desc *desc));
local void gen_codes	OF((ct_data *tree, int max_code, ushf *bl_count));
local void build_tree	OF((deflate_state *s, tree_desc *desc));
local void scan_tree	OF((deflate_state *s, ct_data *tree, int max_code));
local void send_tree	OF((deflate_state *s, ct_data *tree, int max_code));
local int  build_bl_tree	OF((deflate_state *s));
local void send_all_trees	OF((deflate_state *s, int lcodes, int dcodes,
    int blcodes));
local void compress_block OF((deflate_state *s, ct_data *ltree,
    ct_data *dtree));
local void set_data_type	OF((deflate_state *s));
local unsigned bi_reverse	OF((unsigned value, int length));
local void bi_windup	OF((deflate_state *s));
local void bi_flush	OF((deflate_state *s));
local void copy_block	OF((deflate_state *s, charf *buf, unsigned len,
    int header));

#ifndef DEBUG_ZLIB
#define	send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
/* Send a code of the given tree. c and tree must not have side effects */

#else /* DEBUG_ZLIB */
#define	send_code(s, c, tree) \
	{ if (z_verbose > 2) fprintf(stderr, "\ncd %3d ", (c)); \
	send_bits(s, tree[c].Code, tree[c].Len); }
#endif

/*
 * ===========================================================================
 * Output a short LSB first on the stream.
 * IN assertion: there is enough room in pendingBuf.
 */
#define	put_short(s, w) { \
	put_byte(s, (uch)((w) & 0xff)); \
	put_byte(s, (uch)((ush)(w) >> 8)); \
}

/*
 * ===========================================================================
 * Send a value on a given number of bits.
 * IN assertion: length <= 16 and value fits in length bits.
 */
#ifdef DEBUG_ZLIB
local void send_bits	OF((deflate_state *s, int value, int length));

local void
send_bits(s, value, length)
    deflate_state *s;
    int value;	/* value to send */
    int length;	/* number of bits */
{
	Tracevv((stderr, " l %2d v %4x ", length, value));
	Assert(length > 0 && length <= 15, "invalid length");
	s->bits_sent += (ulg)length;

	/*
	 * If not enough room in bi_buf, use (valid) bits from bi_buf
	 * and (16 - bi_valid) bits from value, leaving (width -
	 * (16-bi_valid)) unused bits in value.
	 */
	if (s->bi_valid > (int)Buf_size - length) {
		s->bi_buf |= (value << s->bi_valid);
		put_short(s, s->bi_buf);
		s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
		s->bi_valid += length - Buf_size;
	} else {
		s->bi_buf |= value << s->bi_valid;
		s->bi_valid += length;
	}
}
#else /* !DEBUG_ZLIB */

#define	send_bits(s, value, length) \
{	int len = length; \
	if (s->bi_valid > (int)Buf_size - len) {\
		int val = value; \
		s->bi_buf |= (val << s->bi_valid); \
		put_short(s, s->bi_buf); \
		s->bi_buf = (ush)val >> (Buf_size - s->bi_valid); \
		s->bi_valid += len - Buf_size; \
	} else {\
		s->bi_buf |= (value) << s->bi_valid; \
		s->bi_valid += len; \
	}\
}
#endif /* DEBUG_ZLIB */


#define	MAX(a, b) (a >= b ? a : b)
/* the arguments must not have side effects */

/*
 * ===========================================================================
 * Initialize the various 'constant' tables. In a multi-threaded environment,
 * this function may be called by two threads concurrently, but this is
 * harmless since both invocations do exactly the same thing.
 */
local void
tr_static_init()
{
	static int static_init_done = 0;
	int n;	/* iterates over tree elements */
	int bits;	/* bit counter */
	int length;	/* length value */
	int code;	/* code value */
	int dist;	/* distance index */
	ush bl_count[MAX_BITS+1];
	/* number of codes at each bit length for an optimal tree */

	if (static_init_done)
		return;

	/* For some embedded targets, global variables are not initialized: */
	static_l_desc.static_tree = static_ltree;
	static_l_desc.extra_bits = extra_lbits;
	static_d_desc.static_tree = static_dtree;
	static_d_desc.extra_bits = extra_dbits;
	static_bl_desc.extra_bits = extra_blbits;

	/* Initialize the mapping length (0..255) -> length code (0..28) */
	length = 0;
	for (code = 0; code < LENGTH_CODES-1; code++) {
		base_length[code] = length;
		for (n = 0; n < (1<<extra_lbits[code]); n++) {
			_length_code[length++] = (uch)code;
		}
	}
	Assert(length == 256, "tr_static_init: length != 256");
	/*
	 * Note that the length 255 (match length 258) can be
	 * represented in two different ways: code 284 + 5 bits or
	 * code 285, so we overwrite _length_code[255] to use the best
	 * encoding:
	 */
	_length_code[length-1] = (uch)code;

	/* Initialize the mapping dist (0..32K) -> dist code (0..29) */
	dist = 0;
	for (code = 0; code < 16; code++) {
		base_dist[code] = dist;
		for (n = 0; n < (1<<extra_dbits[code]); n++) {
			_dist_code[dist++] = (uch)code;
		}
	}
	Assert(dist == 256, "tr_static_init: dist != 256");
	dist >>= 7;	/* from now on, all distances are divided by 128 */
	for (; code < D_CODES; code++) {
		base_dist[code] = dist << 7;
		for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
			_dist_code[256 + dist++] = (uch)code;
		}
	}
	Assert(dist == 256, "tr_static_init: 256+dist != 512");

	/* Construct the codes of the static literal tree */
	for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
	n = 0;
	while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
	while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
	while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
	while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
	/*
	 * Codes 286 and 287 do not exist, but we must include them in the
	 * tree construction to get a canonical Huffman tree (longest code
	 * all ones)
	 */
	gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);

	/* The static distance tree is trivial: */
	for (n = 0; n < D_CODES; n++) {
		static_dtree[n].Len = 5;
		static_dtree[n].Code = bi_reverse((unsigned)n, 5);
	}
	static_init_done = 1;
}

/*
 * ===========================================================================
 * Initialize the tree data structures for a new zlib stream.
 */
void
_tr_init(s)
    deflate_state *s;
{
	tr_static_init();

	s->l_desc.dyn_tree = s->dyn_ltree;
	s->l_desc.stat_desc = &static_l_desc;

	s->d_desc.dyn_tree = s->dyn_dtree;
	s->d_desc.stat_desc = &static_d_desc;

	s->bl_desc.dyn_tree = s->bl_tree;
	s->bl_desc.stat_desc = &static_bl_desc;

	s->bi_buf = 0;
	s->bi_valid = 0;
	s->last_eob_len = 8;	/* enough lookahead for inflate */
	s->compressed_len = 0L;		/* PPP */
#ifdef DEBUG_ZLIB
	s->bits_sent = 0L;
#endif

	/* Initialize the first block of the first file: */
	init_block(s);
}

/*
 * ===========================================================================
 * Initialize a new block.
 */
local void
init_block(s)
    deflate_state *s;
{
	int n;	/* iterates over tree elements */

	/* Initialize the trees. */
	for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
	for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
	for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;

	s->dyn_ltree[END_BLOCK].Freq = 1;
	s->opt_len = s->static_len = 0L;
	s->last_lit = s->matches = 0;
}

#define	SMALLEST 1
/* Index within the heap array of least frequent node in the Huffman tree */


/*
 * ===========================================================================
 * Remove the smallest element from the heap and recreate the heap with
 * one less element. Updates heap and heap_len.
 */
#define	pqremove(s, tree, top) \
{\
	top = s->heap[SMALLEST]; \
	s->heap[SMALLEST] = s->heap[s->heap_len--]; \
	pqdownheap(s, tree, SMALLEST); \
}

/*
 * ===========================================================================
 * Compares to subtrees, using the tree depth as tie breaker when
 * the subtrees have equal frequency. This minimizes the worst case length.
 */
#define	smaller(tree, n, m, depth) \
	(tree[n].Freq < tree[m].Freq || \
	(tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
/*
 * ===========================================================================
 * Restore the heap property by moving down the tree starting at node k,
 * exchanging a node with the smallest of its two sons if necessary, stopping
 * when the heap property is re-established (each father smaller than its
 * two sons).
 */
local void
pqdownheap(s, tree, k)
    deflate_state *s;
    ct_data *tree;	/* the tree to restore */
    int k;	/* node to move down */
{
	int v = s->heap[k];
	int j = k << 1;	/* left son of k */
	while (j <= s->heap_len) {
		/* Set j to the smallest of the two sons: */
		if (j < s->heap_len &&
		    smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
			j++;
		}
		/* Exit if v is smaller than both sons */
		if (smaller(tree, v, s->heap[j], s->depth)) break;

		/* Exchange v with the smallest son */
		s->heap[k] = s->heap[j];  k = j;

		/* And continue down the tree, setting j to the left son of k */
		j <<= 1;
	}
	s->heap[k] = v;
}

/*
 * ===========================================================================
 * Compute the optimal bit lengths for a tree and update the total bit length
 * for the current block.
 * IN assertion: the fields freq and dad are set, heap[heap_max] and
 *    above are the tree nodes sorted by increasing frequency.
 * OUT assertions: the field len is set to the optimal bit length, the
 *     array bl_count contains the frequencies for each bit length.
 *     The length opt_len is updated; static_len is also updated if stree is
 *     not null.
 */
local void
gen_bitlen(s, desc)
    deflate_state *s;
    tree_desc *desc;	/* the tree descriptor */
{
	ct_data *tree  = desc->dyn_tree;
	int max_code   = desc->max_code;
	const ct_data *stree = desc->stat_desc->static_tree;
	const intf *extra    = desc->stat_desc->extra_bits;
	int base	= desc->stat_desc->extra_base;
	int max_length = desc->stat_desc->max_length;
	int h;	/* heap index */
	int n, m;	/* iterate over the tree elements */
	int bits;	/* bit length */
	int xbits;	/* extra bits */
	ush f;	/* frequency */
	/* number of elements with bit length too large */
	int overflow = 0;

	for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;

	/*
	 * In a first pass, compute the optimal bit lengths (which may
	 * overflow in the case of the bit length tree).
	 */
	tree[s->heap[s->heap_max]].Len = 0;	/* root of the heap */

	for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
		n = s->heap[h];
		bits = tree[tree[n].Dad].Len + 1;
		if (bits > max_length) bits = max_length, overflow++;
		tree[n].Len = (ush)bits;
		/* We overwrite tree[n].Dad which is no longer needed */

		if (n > max_code) continue;	/* not a leaf node */

		s->bl_count[bits]++;
		xbits = 0;
		if (n >= base) xbits = extra[n-base];
		f = tree[n].Freq;
		s->opt_len += (ulg)f * (bits + xbits);
		if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
	}
	if (overflow == 0)
		return;

	Trace((stderr, "\nbit length overflow\n"));
	/* This happens for example on obj2 and pic of the Calgary corpus */

	/* Find the first bit length which could increase: */
	do {
		bits = max_length-1;
		while (s->bl_count[bits] == 0) bits--;
		s->bl_count[bits]--;	/* move one leaf down the tree */
		/* move one overflow item as its brother */
		s->bl_count[bits+1] += 2;
		s->bl_count[max_length]--;
		/*
		 * The brother of the overflow item also moves one
		 * step up, but this does not affect
		 * bl_count[max_length]
		 */
		overflow -= 2;
	} while (overflow > 0);

	/*
	 * Now recompute all bit lengths, scanning in increasing
	 * frequency.  h is still equal to HEAP_SIZE. (It is simpler
	 * to reconstruct all lengths instead of fixing only the wrong
	 * ones. This idea is taken from 'ar' written by Haruhiko
	 * Okumura.)
	 */
	for (bits = max_length; bits != 0; bits--) {
		n = s->bl_count[bits];
		while (n != 0) {
			m = s->heap[--h];
			if (m > max_code) continue;
			if (tree[m].Len != (unsigned)bits) {
				Trace((stderr, "code %d bits %d->%d\n", m,
				    tree[m].Len, bits));
				s->opt_len += ((long)bits - (long)tree[m].Len)
				    *(long)tree[m].Freq;
				tree[m].Len = (ush)bits;
			}
			n--;
		}
	}
}

/*
 * ===========================================================================
 * Generate the codes for a given tree and bit counts (which need not be
 * optimal).
 * IN assertion: the array bl_count contains the bit length statistics for
 * the given tree and the field len is set for all tree elements.
 * OUT assertion: the field code is set for all tree elements of non
 *     zero code length.
 */
local void
gen_codes(tree, max_code, bl_count)
    ct_data *tree;	/* the tree to decorate */
    int max_code;	/* largest code with non zero frequency */
    ushf *bl_count;	/* number of codes at each bit length */
{
	/* next code value for each bit length */
	ush next_code[MAX_BITS+1];
	ush code = 0;	/* running code value */
	int bits;	/* bit index */
	int n;	/* code index */

	/*
	 * The distribution counts are first used to generate the code
	 * values without bit reversal.
	 */
	for (bits = 1; bits <= MAX_BITS; bits++) {
		next_code[bits] = code = (code + bl_count[bits-1]) << 1;
	}
	/*
	 * Check that the bit counts in bl_count are consistent. The
	 * last code must be all ones.
	 */
	Assert(code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
	    "inconsistent bit counts");
	Tracev((stderr, "\ngen_codes: max_code %d ", max_code));

	for (n = 0;  n <= max_code; n++) {
		int len = tree[n].Len;
		if (len == 0) continue;
		/* Now reverse the bits */
		tree[n].Code = bi_reverse(next_code[len]++, len);

		Tracecv(tree != static_ltree,
		    (stderr, "\nn %3d %c l %2d c %4x (%x) ",
		    n, (isgraph(n) ? n : ' '), len, tree[n].Code,
			next_code[len]-1));
	}
}

/*
 * ===========================================================================
 * Construct one Huffman tree and assigns the code bit strings and lengths.
 * Update the total bit length for the current block.
 * IN assertion: the field freq is set for all tree elements.
 * OUT assertions: the fields len and code are set to the optimal bit length
 *     and corresponding code. The length opt_len is updated; static_len is
 *     also updated if stree is not null. The field max_code is set.
 */
local void
build_tree(s, desc)
    deflate_state *s;
    tree_desc *desc;	/* the tree descriptor */
{
	ct_data *tree   = desc->dyn_tree;
	const ct_data *stree  = desc->stat_desc->static_tree;
	int elems	= desc->stat_desc->elems;
	int n, m;	/* iterate over heap elements */
	int max_code = -1;	/* largest code with non zero frequency */
	int node;	/* new node being created */

	/*
	 * Construct the initial heap, with least frequent element in
	 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and
	 * heap[2*n+1].  heap[0] is not used.
	 */
	s->heap_len = 0, s->heap_max = HEAP_SIZE;

	for (n = 0; n < elems; n++) {
		if (tree[n].Freq != 0) {
			s->heap[++(s->heap_len)] = max_code = n;
			s->depth[n] = 0;
		} else {
			tree[n].Len = 0;
		}
	}

	/*
	 * The pkzip format requires that at least one distance code
	 * exists, and that at least one bit should be sent even if
	 * there is only one possible code. So to avoid special checks
	 * later on we force at least two codes of non zero frequency.
	 */
	while (s->heap_len < 2) {
		node = s->heap[++(s->heap_len)] = (max_code < 2 ?
		    ++max_code : 0);
		tree[node].Freq = 1;
		s->depth[node] = 0;
		s->opt_len--; if (stree) s->static_len -= stree[node].Len;
		/* node is 0 or 1 so it does not have extra bits */
	}
	desc->max_code = max_code;

	/*
	 * The elements heap[heap_len/2+1 .. heap_len] are leaves of
	 * the tree, establish sub-heaps of increasing lengths:
	 */
	for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);

	/*
	 * Construct the Huffman tree by repeatedly combining the
	 * least two frequent nodes.
	 */
	node = elems;	/* next internal node of the tree */
	do {
		pqremove(s, tree, n);	/* n = node of least frequency */
		m = s->heap[SMALLEST];	/* m = node of next least frequency */

		/* keep the nodes sorted by frequency */
		s->heap[--(s->heap_max)] = n;
		s->heap[--(s->heap_max)] = m;

		/* Create a new node father of n and m */
		tree[node].Freq = tree[n].Freq + tree[m].Freq;
		s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
		tree[n].Dad = tree[m].Dad = (ush)node;
#ifdef DUMP_BL_TREE
		if (tree == s->bl_tree) {
			fprintf(stderr, "\nnode %d(%d), sons %d(%d) %d(%d)",
			    node, tree[node].Freq, n, tree[n].Freq, m,
			    tree[m].Freq);
		}
#endif
		/* and insert the new node in the heap */
		s->heap[SMALLEST] = node++;
		pqdownheap(s, tree, SMALLEST);

	} while (s->heap_len >= 2);

	s->heap[--(s->heap_max)] = s->heap[SMALLEST];

	/*
	 * At this point, the fields freq and dad are set. We can now
	 * generate the bit lengths.
	 */
	gen_bitlen(s, (tree_desc *)desc);

	/* The field len is now set, we can generate the bit codes */
	gen_codes((ct_data *)tree, max_code, s->bl_count);
}

/*
 * ===========================================================================
 * Scan a literal or distance tree to determine the frequencies of the codes
 * in the bit length tree.
 */
local void
scan_tree(s, tree, max_code)
    deflate_state *s;
    ct_data *tree;	/* the tree to be scanned */
    int max_code;	/* and its largest code of non zero frequency */
{
	int n;	/* iterates over all tree elements */
	int prevlen = -1;	/* last emitted length */
	int curlen;	/* length of current code */
	int nextlen = tree[0].Len;	/* length of next code */
	int count = 0;	/* repeat count of the current code */
	int max_count = 7;	/* max repeat count */
	int min_count = 4;	/* min repeat count */

	if (nextlen == 0) max_count = 138, min_count = 3;
	tree[max_code+1].Len = (ush)0xffff;	/* guard */

	for (n = 0; n <= max_code; n++) {
		curlen = nextlen; nextlen = tree[n+1].Len;
		if (++count < max_count && curlen == nextlen) {
			continue;
		} else if (count < min_count) {
			s->bl_tree[curlen].Freq += count;
		} else if (curlen != 0) {
			if (curlen != prevlen) s->bl_tree[curlen].Freq++;
			s->bl_tree[REP_3_6].Freq++;
		} else if (count <= 10) {
			s->bl_tree[REPZ_3_10].Freq++;
		} else {
			s->bl_tree[REPZ_11_138].Freq++;
		}
		count = 0; prevlen = curlen;
		if (nextlen == 0) {
			max_count = 138, min_count = 3;
		} else if (curlen == nextlen) {
			max_count = 6, min_count = 3;
		} else {
			max_count = 7, min_count = 4;
		}
	}
}

/*
 * ===========================================================================
 * Send a literal or distance tree in compressed form, using the codes in
 * bl_tree.
 */
local void
send_tree(s, tree, max_code)
    deflate_state *s;
    ct_data *tree;	/* the tree to be scanned */
    int max_code;	/* and its largest code of non zero frequency */
{
	int n;	/* iterates over all tree elements */
	int prevlen = -1;	/* last emitted length */
	int curlen;	/* length of current code */
	int nextlen = tree[0].Len;	/* length of next code */
	int count = 0;	/* repeat count of the current code */
	int max_count = 7;	/* max repeat count */
	int min_count = 4;	/* min repeat count */

	/* tree[max_code+1].Len = -1; */  /* guard already set */
	if (nextlen == 0) max_count = 138, min_count = 3;

	for (n = 0; n <= max_code; n++) {
		curlen = nextlen; nextlen = tree[n+1].Len;
		if (++count < max_count && curlen == nextlen) {
			continue;
		} else if (count < min_count) {
			do { send_code(s, curlen, s->bl_tree); }
			while (--count != 0);

		} else if (curlen != 0) {
			if (curlen != prevlen) {
				send_code(s, curlen, s->bl_tree); count--;
			}
			Assert(count >= 3 && count <= 6, " 3_6?");
			send_code(s, REP_3_6, s->bl_tree);
			send_bits(s, count-3, 2);

		} else if (count <= 10) {
			send_code(s, REPZ_3_10, s->bl_tree);
			send_bits(s, count-3, 3);

		} else {
			send_code(s, REPZ_11_138, s->bl_tree);
			send_bits(s, count-11, 7);
		}
		count = 0; prevlen = curlen;
		if (nextlen == 0) {
			max_count = 138, min_count = 3;
		} else if (curlen == nextlen) {
			max_count = 6, min_count = 3;
		} else {
			max_count = 7, min_count = 4;
		}
	}
}

/*
 * ===========================================================================
 * Construct the Huffman tree for the bit lengths and return the index in
 * bl_order of the last bit length code to send.
 */
local int
build_bl_tree(s)
    deflate_state *s;
{
	/* index of last bit length code of non zero freq */
	int max_blindex;

	/*
	 * Determine the bit length frequencies for literal and
	 * distance trees
	 */
	scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
	scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);

	/* Build the bit length tree: */
	build_tree(s, (tree_desc *)(&(s->bl_desc)));
	/*
	 * opt_len now includes the length of the tree
	 * representations, except the lengths of the bit lengths
	 * codes and the 5+5+4 bits for the counts.
	 */

	/*
	 * Determine the number of bit length codes to send. The pkzip
	 * format requires that at least 4 bit length codes be
	 * sent. (appnote.txt says 3 but the actual value used is 4.)
	 */
	for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
		if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
	}
	/* Update opt_len to include the bit length tree and counts */
	s->opt_len += 3*(max_blindex+1) + 5+5+4;
	Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
	    s->opt_len, s->static_len));

	return (max_blindex);
}

/*
 * ===========================================================================
 * Send the header for a block using dynamic Huffman trees: the counts, the
 * lengths of the bit length codes, the literal tree and the distance tree.
 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
 */
local void
send_all_trees(s, lcodes, dcodes, blcodes)
    deflate_state *s;
    int lcodes, dcodes, blcodes;	/* number of codes for each tree */
{
	int rank;	/* index in bl_order */

	Assert(lcodes >= 257 && dcodes >= 1 && blcodes >= 4,
	    "not enough codes");
	Assert(lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
	    "too many codes");
	Tracev((stderr, "\nbl counts: "));
	send_bits(s, lcodes-257, 5);	/* not +255 as stated in appnote.txt */
	send_bits(s, dcodes-1,   5);
	send_bits(s, blcodes-4,  4);	/* not -3 as stated in appnote.txt */
	for (rank = 0; rank < blcodes; rank++) {
		Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
		send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
	}
#ifdef DEBUG_ZLIB
	Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
#endif

	/* literal tree */
	send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1);
#ifdef DEBUG_ZLIB
	Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
#endif

	/* distance tree */
	send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1);
#ifdef DEBUG_ZLIB
	Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
#endif
}

/*
 * ===========================================================================
 * Send a stored block
 */
void
_tr_stored_block(s, buf, stored_len, eof)
    deflate_state *s;
    charf *buf;	/* input block */
    ulg stored_len;	/* length of input block */
    int eof;	/* true if this is the last block for a file */
{
	send_bits(s, (STORED_BLOCK<<1)+eof, 3);	/* send block type */
	s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; /* PPP */
	s->compressed_len += (stored_len + 4) << 3;	/* PPP */

	copy_block(s, buf, (unsigned)stored_len, 1);	/* with header */
}

/*
 * Send just the `stored block' type code without any length bytes or data.
 * ---PPP---
 */
void
_tr_stored_type_only(s)
    deflate_state *s;
{
	send_bits(s, (STORED_BLOCK << 1), 3);
	bi_windup(s);
	s->compressed_len = (s->compressed_len + 3) & ~7L;	/* PPP */
}


/*
 * ===========================================================================
 * Send one empty static block to give enough lookahead for inflate.
 * This takes 10 bits, of which 7 may remain in the bit buffer.
 * The current inflate code requires 9 bits of lookahead. If the
 * last two codes for the previous block (real code plus EOB) were coded
 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
 * the last real code. In this case we send two empty static blocks instead
 * of one. (There are no problems if the previous block is stored or fixed.)
 * To simplify the code, we assume the worst case of last real code encoded
 * on one bit only.
 */
void
_tr_align(s)
    deflate_state *s;
{
	send_bits(s, STATIC_TREES<<1, 3);
	send_code(s, END_BLOCK, static_ltree);
	s->compressed_len += 10L;	/* 3 for block type, 7 for EOB */
	bi_flush(s);
	/*
	 * Of the 10 bits for the empty block, we have already sent
	 * (10 - bi_valid) bits. The lookahead for the last real code
	 * (before the EOB of the previous block) was thus at least
	 * one plus the length of the EOB plus what we have just sent
	 * of the empty static block.
	 */
	if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
		send_bits(s, STATIC_TREES<<1, 3);
		send_code(s, END_BLOCK, static_ltree);
		s->compressed_len += 10L;
		bi_flush(s);
	}
	s->last_eob_len = 7;
}

/*
 * ===========================================================================
 * Determine the best encoding for the current block: dynamic trees, static
 * trees or store, and output the encoded block to the zip file.
 */
void
_tr_flush_block(s, buf, stored_len, eof)
    deflate_state *s;
    charf *buf;	/* input block, or NULL if too old */
    ulg stored_len;	/* length of input block */
    int eof;	/* true if this is the last block for a file */
{
	ulg opt_lenb, static_lenb;	/* opt_len and static_len in bytes */
	/* index of last bit length code of non zero freq */
	int max_blindex = 0;

	/* Build the Huffman trees unless a stored block is forced */
	if (s->level > 0) {

		/* Check if the file is ascii or binary */
		if (s->data_type == Z_UNKNOWN) set_data_type(s);

		/* Construct the literal and distance trees */
		build_tree(s, (tree_desc *)(&(s->l_desc)));
		Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
		    s->static_len));

		build_tree(s, (tree_desc *)(&(s->d_desc)));
		Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
		    s->static_len));
		/*
		 * At this point, opt_len and static_len are the total
		 * bit lengths of the compressed block data, excluding
		 * the tree representations.
		 */

		/*
		 * Build the bit length tree for the above two trees,
		 * and get the index in bl_order of the last bit
		 * length code to send.
		 */
		max_blindex = build_bl_tree(s);

		/*
		 * Determine the best encoding. Compute first the
		 * block length in bytes
		 */
		opt_lenb = (s->opt_len+3+7)>>3;
		static_lenb = (s->static_len+3+7)>>3;

		Tracev((stderr,
		    "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
		    opt_lenb, s->opt_len, static_lenb, s->static_len,
		    stored_len, s->last_lit));

		if (static_lenb <= opt_lenb) opt_lenb = static_lenb;

	} else {
		Assert(buf != (char *)0, "lost buf");
		/* force a stored block */
		opt_lenb = static_lenb = stored_len + 5;
	}

	/*
	 * If compression failed and this is the first and last block,
	 * and if the .zip file can be seeked (to rewrite the local
	 * header), the whole file is transformed into a stored file:
	 */
#ifdef STORED_FILE_OK
#ifdef FORCE_STORED_FILE
#define	FRC_STR_COND	eof && s->compressed_len == 0L /* force stored file */
#else
#define	FRC_STR_COND	stored_len <= opt_lenb && eof && \
			s->compressed_len == 0L && seekable()
#endif
	if (FRC_STR_COND) {
#undef FRC_STR_COND
		/*
		 * Since LIT_BUFSIZE <= 2*WSIZE, the input data must
		 * be there:
		 */
		if (buf == (charf*)0) error("block vanished");

		/* without header */
		copy_block(s, buf, (unsigned)stored_len, 0);
		s->compressed_len = stored_len << 3;
		s->method = STORED;
	} else
#endif /* STORED_FILE_OK */

#ifdef FORCE_STORED
#define	FRC_STR_COND	buf != (char *)0	/* force stored block */
#else
			/* 4: two words for the lengths */
#define	FRC_STR_COND	stored_len+4 <= opt_lenb && buf != (char *)0
#endif
		if (FRC_STR_COND) {
#undef FRC_STR_COND
			/*
			 * The test buf != NULL is only necessary if
			 * LIT_BUFSIZE > WSIZE.  Otherwise we can't
			 * have processed more than WSIZE input bytes
			 * since the last block flush, because
			 * compression would have been successful. If
			 * LIT_BUFSIZE <= WSIZE, it is never too late
			 * to transform a block into a stored block.
			 */
			_tr_stored_block(s, buf, stored_len, eof);
#ifdef FORCE_STATIC
#define	FRC_STAT_COND	static_lenb >= 0 /* force static trees */
#else
#define	FRC_STAT_COND	static_lenb == opt_lenb
#endif
		} else if (FRC_STAT_COND) {
#undef FRC_STAT_COND
			send_bits(s, (STATIC_TREES<<1)+eof, 3);
			compress_block(s, (ct_data *)static_ltree,
			    (ct_data *)static_dtree);
			s->compressed_len += 3 + s->static_len;	/* PPP */
		} else {
			send_bits(s, (DYN_TREES<<1)+eof, 3);
			send_all_trees(s, s->l_desc.max_code+1,
			    s->d_desc.max_code+1,
			    max_blindex+1);
			compress_block(s, (ct_data *)s->dyn_ltree,
			    (ct_data *)s->dyn_dtree);
			s->compressed_len += 3 + s->opt_len;	/* PPP */
		}
#ifdef DEBUG_ZLIB
	Assert(s->compressed_len == s->bits_sent, "bad compressed size");
#endif
	/*
	 * The above check is made mod 2^32, for files larger than 512
	 * MB and uLong implemented on 32 bits.
	 */
	init_block(s);

	if (eof) {
		bi_windup(s);
		s->compressed_len += 7;	/* align on byte boundary PPP */
	}
	Tracev((stderr, "\ncomprlen %lu(%lu) ", s->compressed_len>>3,
	    s->compressed_len-7*eof));

	/* return (s->compressed_len >> 3); */
}

/*
 * ===========================================================================
 * Save the match info and tally the frequency counts. Return true if
 * the current block must be flushed.
 */
int
_tr_tally(s, dist, lc)
    deflate_state *s;
    unsigned dist;	/* distance of matched string */
	/* match length-MIN_MATCH or unmatched char (if dist==0) */
    unsigned lc;
{
	s->d_buf[s->last_lit] = (ush)dist;
	s->l_buf[s->last_lit++] = (uch)lc;
	if (dist == 0) {
		/* lc is the unmatched char */
		s->dyn_ltree[lc].Freq++;
	} else {
		s->matches++;
		/* Here, lc is the match length - MIN_MATCH */
		dist--;	/* dist = match distance - 1 */
		Assert((ush)dist < (ush)MAX_DIST(s) &&
		    (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
		    (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");

		s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
		s->dyn_dtree[d_code(dist)].Freq++;
	}

#ifdef TRUNCATE_BLOCK
	/* Try to guess if it is profitable to stop the current block here */
	if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
		/* Compute an upper bound for the compressed length */
		ulg out_length = (ulg)s->last_lit*8L;
		ulg in_length = (ulg)((long)s->strstart - s->block_start);
		int dcode;
		for (dcode = 0; dcode < D_CODES; dcode++) {
			out_length += (ulg)s->dyn_dtree[dcode].Freq *
			    (5L+extra_dbits[dcode]);
		}
		out_length >>= 3;
		Tracev((stderr, "\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
		    s->last_lit, in_length, out_length,
		    100L - out_length*100L/in_length));
		if (s->matches < s->last_lit/2 && out_length < in_length/2)
			return (1);
	}
#endif
	return (s->last_lit == s->lit_bufsize-1);
	/*
	 * We avoid equality with lit_bufsize because of wraparound at 64K
	 * on 16 bit machines and because stored blocks are restricted to
	 * 64K-1 bytes.
	 */
}

/*
 * ===========================================================================
 * Send the block data compressed using the given Huffman trees
 */
local void
compress_block(s, ltree, dtree)
    deflate_state *s;
    ct_data *ltree;	/* literal tree */
    ct_data *dtree;	/* distance tree */
{
	unsigned dist;	/* distance of matched string */
	int lc;	/* match length or unmatched char (if dist == 0) */
	unsigned lx = 0;	/* running index in l_buf */
	unsigned code;	/* the code to send */
	int extra;	/* number of extra bits to send */

	if (s->last_lit != 0) do {
		dist = s->d_buf[lx];
		lc = s->l_buf[lx++];
		if (dist == 0) {
			/* send a literal byte */
			send_code(s, lc, ltree);
			Tracecv(isgraph(lc), (stderr, " '%c' ", lc));
		} else {
			/* Here, lc is the match length - MIN_MATCH */
			code = _length_code[lc];
			/* send the length code */
			send_code(s, code+LITERALS+1, ltree);
			extra = extra_lbits[code];
			if (extra != 0) {
				lc -= base_length[code];
				/* send the extra length bits */
				send_bits(s, lc, extra);
			}
			/* dist is now the match distance - 1 */
			dist--;
			code = d_code(dist);
			Assert(code < D_CODES, "bad d_code");

			/* send the distance code */
			send_code(s, code, dtree);
			extra = extra_dbits[code];
			if (extra != 0) {
				dist -= base_dist[code];
				/* send the extra distance bits */
				send_bits(s, dist, extra);
			}
		} /* literal or match pair ? */

		/*
		 * Check that the overlay between pending_buf and
		 * d_buf+l_buf is ok:
		 */
		Assert(s->pending < s->lit_bufsize + 2*lx,
		    "pendingBuf overflow");

	} while (lx < s->last_lit);

	send_code(s, END_BLOCK, ltree);
	s->last_eob_len = ltree[END_BLOCK].Len;
}

/*
 * ===========================================================================
 * Set the data type to ASCII or BINARY, using a crude approximation:
 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
 * IN assertion: the fields freq of dyn_ltree are set and the total of all
 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
 */
local void
set_data_type(s)
    deflate_state *s;
{
	int n = 0;
	unsigned ascii_freq = 0;
	unsigned bin_freq = 0;
	while (n < 7)	bin_freq	+= s->dyn_ltree[n++].Freq;
	while (n < 128)	ascii_freq	+= s->dyn_ltree[n++].Freq;
	while (n < LITERALS) bin_freq	+= s->dyn_ltree[n++].Freq;
	s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ?
	    Z_BINARY : Z_ASCII);
}

/*
 * ===========================================================================
 * Reverse the first len bits of a code, using straightforward code (a faster
 * method would use a table)
 * IN assertion: 1 <= len <= 15
 */
local unsigned
bi_reverse(code, len)
    unsigned code;	/* the value to invert */
    int len;	/* its bit length */
{
	register unsigned res = 0;
	do {
		res |= code & 1;
		code >>= 1, res <<= 1;
	} while (--len > 0);
	return (res >> 1);
}

/*
 * ===========================================================================
 * Flush the bit buffer, keeping at most 7 bits in it.
 */
local void
bi_flush(s)
    deflate_state *s;
{
	if (s->bi_valid == 16) {
		put_short(s, s->bi_buf);
		s->bi_buf = 0;
		s->bi_valid = 0;
	} else if (s->bi_valid >= 8) {
		put_byte(s, (Byte)s->bi_buf);
		s->bi_buf >>= 8;
		s->bi_valid -= 8;
	}
}

/*
 * ===========================================================================
 * Flush the bit buffer and align the output on a byte boundary
 */
local void
bi_windup(s)
    deflate_state *s;
{
	if (s->bi_valid > 8) {
		put_short(s, s->bi_buf);
	} else if (s->bi_valid > 0) {
		put_byte(s, (Byte)s->bi_buf);
	}
	s->bi_buf = 0;
	s->bi_valid = 0;
#ifdef DEBUG_ZLIB
	s->bits_sent = (s->bits_sent+7) & ~7;
#endif
}

/*
 * ===========================================================================
 * Copy a stored block, storing first the length and its
 * one's complement if requested.
 */
local void
copy_block(s, buf, len, header)
    deflate_state *s;
    charf    *buf;	/* the input data */
    unsigned len;	/* its length */
    int	header;	/* true if block header must be written */
{
	bi_windup(s);	/* align on byte boundary */
	s->last_eob_len = 8;	/* enough lookahead for inflate */

	if (header) {
		put_short(s, (ush)len);
		put_short(s, (ush)~len);
#ifdef DEBUG_ZLIB
		s->bits_sent += 2*16;
#endif
	}
#ifdef DEBUG_ZLIB
	s->bits_sent += (ulg)len<<3;
#endif
	/* bundle up the put_byte(s, *buf++) calls PPP */
	Assert(s->pending + len < s->pending_buf_size, "pending_buf overrun");
	zmemcpy(&s->pending_buf[s->pending], buf, len);	/* PPP */
	s->pending += len;				/* PPP */
}
/* --- trees.c */

/* +++ inflate.c */
/*
 * inflate.c -- zlib interface to inflate modules
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* #include "zutil.h" */

/* +++ infblock.h */
/*
 * infblock.h -- header to use infblock.c
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 * WARNING: this file should *not* be used by applications. It is part
 * of the implementation of the compression library and is subject to
 * change. Applications should only use zlib.h.
 */

struct inflate_blocks_state;
typedef struct inflate_blocks_state FAR inflate_blocks_statef;

extern inflate_blocks_statef * inflate_blocks_new OF((
    z_streamp z,
    check_func c,	/* check function */
    uInt w));	/* window size */

extern int inflate_blocks OF((
    inflate_blocks_statef *,
    z_streamp,
    int));	/* initial return code */

extern void inflate_blocks_reset OF((
    inflate_blocks_statef *,
    z_streamp,
    uLongf *));	/* check value on output */

extern int inflate_blocks_free OF((
    inflate_blocks_statef *,
    z_streamp));

extern void inflate_set_dictionary OF((
    inflate_blocks_statef *s,
    const Bytef *d,  /* dictionary */
    uInt  n));	/* dictionary length */

extern int inflate_blocks_sync_point OF((
    inflate_blocks_statef *s));

/* PPP -- added function */
extern int inflate_addhistory OF((
    inflate_blocks_statef *,
    z_streamp));

/* PPP -- added function */
extern int inflate_packet_flush OF((
    inflate_blocks_statef *));
/* --- infblock.h */

#ifndef NO_DUMMY_DECL
struct inflate_blocks_state {int dummy; };	/* for buggy compilers */
#endif

/* inflate private state */
struct internal_state {

	/* mode */
	enum {
		METHOD,	/* waiting for method byte */
		FLAG,	/* waiting for flag byte */
		DICT4,	/* four dictionary check bytes to go */
		DICT3,	/* three dictionary check bytes to go */
		DICT2,	/* two dictionary check bytes to go */
		DICT1,	/* one dictionary check byte to go */
		DICT0,	/* waiting for inflateSetDictionary */
		BLOCKS,	/* decompressing blocks */
		CHECK4,	/* four check bytes to go */
		CHECK3,	/* three check bytes to go */
		CHECK2,	/* two check bytes to go */
		CHECK1,	/* one check byte to go */
		DONE,	/* finished check, done */
		BAD}	/* got an error--stay here */
	mode;	/* current inflate mode */

	/* mode dependent information */
	union {
		uInt method;	/* if FLAGS, method byte */
		struct {
			uLong was;	/* computed check value */
			uLong need;	/* stream check value */
		} check;	/* if CHECK, check values to compare */
		uInt marker;	/* if BAD, inflateSync's marker bytes count */
	} sub;	/* submode */

	/* mode independent information */
	int  nowrap;	/* flag for no wrapper */
	uInt wbits;	/* log2(window size)  (8..15, defaults to 15) */
	/* current inflate_blocks state */
	inflate_blocks_statef *blocks;
};


int
inflateReset(z)
z_streamp z;
{
	if (z == Z_NULL || z->state == Z_NULL)
		return (Z_STREAM_ERROR);
	z->total_in = z->total_out = 0;
	z->msg = Z_NULL;
	z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
	inflate_blocks_reset(z->state->blocks, z, Z_NULL);
	Trace((stderr, "inflate: reset\n"));
	return (Z_OK);
}


int
inflateEnd(z)
z_streamp z;
{
	if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
		return (Z_STREAM_ERROR);
	if (z->state->blocks != Z_NULL) {
		(void) inflate_blocks_free(z->state->blocks, z);
		z->state->blocks = Z_NULL;
	}
	ZFREE(z, z->state);
	z->state = Z_NULL;
	Trace((stderr, "inflate: end\n"));
	return (Z_OK);
}


int
inflateInit2_(z, w, version, stream_size)
z_streamp z;
int w;
const char *version;
int stream_size;
{
	if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
	    stream_size != sizeof (z_stream))
		return (Z_VERSION_ERROR);

	/* initialize state */
	if (z == Z_NULL)
		return (Z_STREAM_ERROR);
	z->msg = Z_NULL;
#ifndef NO_ZCFUNCS
	if (z->zalloc == Z_NULL)
	{
		z->zalloc = zcalloc;
		z->opaque = (voidpf)0;
	}
	if (z->zfree == Z_NULL) z->zfree = zcfree;
#endif
	if ((z->state = (struct internal_state FAR *)
	    ZALLOC(z, 1, sizeof (struct internal_state))) == Z_NULL)
		return (Z_MEM_ERROR);
	z->state->blocks = Z_NULL;

	/* handle undocumented nowrap option (no zlib header or check) */
	z->state->nowrap = 0;
	if (w < 0)
	{
		w = - w;
		z->state->nowrap = 1;
	}

	/* set window size */
	if (w < 8 || w > 15)
	{
		(void) inflateEnd(z);
		return (Z_STREAM_ERROR);
	}
	z->state->wbits = (uInt)w;

	/* create inflate_blocks state */
	if ((z->state->blocks =
	    inflate_blocks_new(z, z->state->nowrap ?
		Z_NULL : adler32, (uInt)1 << w))
	    == Z_NULL)
	{
		(void) inflateEnd(z);
		return (Z_MEM_ERROR);
	}
	Trace((stderr, "inflate: allocated\n"));

	/* reset state */
	(void) inflateReset(z);
	return (Z_OK);
}


int
inflateInit_(z, version, stream_size)
z_streamp z;
const char *version;
int stream_size;
{
	return (inflateInit2_(z, DEF_WBITS, version, stream_size));
}

/* PPP -- added "empty" label and changed f to Z_OK */
#define	NEEDBYTE {if (z->avail_in == 0) goto empty; r = Z_OK; } ((void)0)
#define	NEXTBYTE (z->avail_in--, z->total_in++, *z->next_in++)

int
inflate(z, f)
z_streamp z;
int f;
{
	int r;
	uInt b;

	if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
		return (Z_STREAM_ERROR);
	/* f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK; -- PPP; Z_FINISH unused */
	r = Z_BUF_ERROR;
	/* CONSTCOND */
	while (1)
		switch (z->state->mode)
	{
	case METHOD:
		NEEDBYTE;
		if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
		{
			z->state->mode = BAD;
			z->msg = "unknown compression method";
			/* can't try inflateSync */
			z->state->sub.marker = 5;
			break;
		}
		if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
		{
			z->state->mode = BAD;
			z->msg = "invalid window size";
			/* can't try inflateSync */
			z->state->sub.marker = 5;
			break;
		}
		z->state->mode = FLAG;
		/* FALLTHRU */
	case FLAG:
		NEEDBYTE;
		b = NEXTBYTE;
		if (((z->state->sub.method << 8) + b) % 31)
		{
			z->state->mode = BAD;
			z->msg = "incorrect header check";
			/* can't try inflateSync */
			z->state->sub.marker = 5;
			break;
		}
		Trace((stderr, "inflate: zlib header ok\n"));
		if (!(b & PRESET_DICT))
		{
			z->state->mode = BLOCKS;
			break;
		}
		z->state->mode = DICT4;
		/* FALLTHRU */
	case DICT4:
		NEEDBYTE;
		z->state->sub.check.need = (uLong)NEXTBYTE << 24;
		z->state->mode = DICT3;
		/* FALLTHRU */
	case DICT3:
		NEEDBYTE;
		z->state->sub.check.need += (uLong)NEXTBYTE << 16;
		z->state->mode = DICT2;
		/* FALLTHRU */
	case DICT2:
		NEEDBYTE;
		z->state->sub.check.need += (uLong)NEXTBYTE << 8;
		z->state->mode = DICT1;
		/* FALLTHRU */
	case DICT1:
		NEEDBYTE;
		z->state->sub.check.need += (uLong)NEXTBYTE;
		z->adler = z->state->sub.check.need;
		z->state->mode = DICT0;
		return (Z_NEED_DICT);
	case DICT0:
		z->state->mode = BAD;
		z->msg = "need dictionary";
		z->state->sub.marker = 0;	/* can try inflateSync */
		return (Z_STREAM_ERROR);
	case BLOCKS:
		r = inflate_blocks(z->state->blocks, z, r);
		if (f == Z_PACKET_FLUSH && z->avail_in == 0 &&	/* PPP */
		    z->avail_out != 0)				/* PPP */
			r = inflate_packet_flush(z->state->blocks); /* PPP */
		if (r == Z_DATA_ERROR)
		{
			z->state->mode = BAD;
			/* can try inflateSync */
			z->state->sub.marker = 0;
			break;
		}
		/* PPP */
		if (r != Z_STREAM_END)
			return (r);
		r = Z_OK;	/* PPP */
		inflate_blocks_reset(z->state->blocks, z,
		    &z->state->sub.check.was);
		if (z->state->nowrap)
		{
			z->state->mode = DONE;
			break;
		}
		z->state->mode = CHECK4;
		/* FALLTHRU */
	case CHECK4:
		NEEDBYTE;
		z->state->sub.check.need = (uLong)NEXTBYTE << 24;
		z->state->mode = CHECK3;
		/* FALLTHRU */
	case CHECK3:
		NEEDBYTE;
		z->state->sub.check.need += (uLong)NEXTBYTE << 16;
		z->state->mode = CHECK2;
		/* FALLTHRU */
	case CHECK2:
		NEEDBYTE;
		z->state->sub.check.need += (uLong)NEXTBYTE << 8;
		z->state->mode = CHECK1;
		/* FALLTHRU */
	case CHECK1:
		NEEDBYTE;
		z->state->sub.check.need += (uLong)NEXTBYTE;

		if (z->state->sub.check.was != z->state->sub.check.need)
		{
			z->state->mode = BAD;
			z->msg = "incorrect data check";
			/* can't try inflateSync */
			z->state->sub.marker = 5;
			break;
		}
		Trace((stderr, "inflate: zlib check ok\n"));
		z->state->mode = DONE;
		/* FALLTHRU */
	case DONE:
		return (Z_STREAM_END);
	case BAD:
		return (Z_DATA_ERROR);
	default:
		return (Z_STREAM_ERROR);
	}

/* PPP -- packet flush handling */
empty:
	if (f != Z_PACKET_FLUSH)
		return (r);
	z->state->mode = BAD;
	z->msg = "need more for packet flush";
	z->state->sub.marker = 0;	/* can try inflateSync */
	return (Z_DATA_ERROR);
}


int
inflateSetDictionary(z, dictionary, dictLength)
z_streamp z;
const Bytef *dictionary;
uInt  dictLength;
{
	uInt length = dictLength;

	if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
		return (Z_STREAM_ERROR);

	if (adler32(1L, dictionary, dictLength) != z->adler)
		return (Z_DATA_ERROR);
	z->adler = 1L;

	if (length >= ((uInt)1<<z->state->wbits))
	{
		length = (1<<z->state->wbits)-1;
		dictionary += dictLength - length;
	}
	inflate_set_dictionary(z->state->blocks, dictionary, length);
	z->state->mode = BLOCKS;
	return (Z_OK);
}

/*
 * This subroutine adds the data at next_in/avail_in to the output history
 * without performing any output.  The output buffer must be "caught up";
 * i.e. no pending output (hence s->read equals s->write), and the state must
 * be BLOCKS (i.e. we should be willing to see the start of a series of
 * BLOCKS).  On exit, the output will also be caught up, and the checksum
 * will have been updated if need be.
 *
 * Added for PPP.
 */

int
inflateIncomp(z)
z_stream *z;
{
	if (z->state->mode != BLOCKS)
		return (Z_DATA_ERROR);
	return (inflate_addhistory(z->state->blocks, z));
}


int
inflateSync(z)
z_streamp z;
{
	uInt n;	/* number of bytes to look at */
	Bytef *p;	/* pointer to bytes */
	uInt m;	/* number of marker bytes found in a row */
	uLong r, w;	/* temporaries to save total_in and total_out */

	/* set up */
	if (z == Z_NULL || z->state == Z_NULL)
		return (Z_STREAM_ERROR);
	if (z->state->mode != BAD)
	{
		z->state->mode = BAD;
		z->state->sub.marker = 0;
	}
	if ((n = z->avail_in) == 0)
		return (Z_BUF_ERROR);
	p = z->next_in;
	m = z->state->sub.marker;

	/* search */
	while (n && m < 4)
	{
		static const Byte mark[4] = { 0, 0, 0xff, 0xff };
		if (*p == mark[m])
			m++;
		else if (*p)
			m = 0;
		else
			/*
			 * This statement maps 2->2 and 3->1 because a
			 * mismatch with input byte 0x00 on the first
			 * 0xFF in the pattern means that we still
			 * have two contiguous zeros matched (thus
			 * offset 2 is kept), but a mismatch on the
			 * second 0xFF means that only one 0x00 byte
			 * has been matched.  (Boyer-Moore like
			 * search.)
			 */
			m = 4 - m;
		p++, n--;
	}

	/* restore */
	z->total_in += p - z->next_in;
	z->next_in = p;
	z->avail_in = n;
	z->state->sub.marker = m;

	/* return no joy or set up to restart on a new block */
	if (m != 4)
		return (Z_DATA_ERROR);
	r = z->total_in;  w = z->total_out;
	(void) inflateReset(z);
	z->total_in = r;  z->total_out = w;
	z->state->mode = BLOCKS;
	return (Z_OK);
}

/*
 * Returns true if inflate is currently at the end of a block
 * generated by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by
 * one PPP implementation to provide an additional safety check. PPP
 * uses Z_SYNC_FLUSH but removes the length bytes of the resulting
 * empty stored block. When decompressing, PPP checks that at the end
 * of input packet, inflate is waiting for these length bytes.
 */
int
inflateSyncPoint(z)
z_streamp z;
{
	if (z == Z_NULL || z->state == Z_NULL || z->state->blocks == Z_NULL)
		return (Z_STREAM_ERROR);
	return (inflate_blocks_sync_point(z->state->blocks));
}

#undef NEEDBYTE
#undef NEXTBYTE
/* --- inflate.c */

/* +++ infblock.c */
/*
 * infblock.c -- interpret and process block types to last block
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* #include "zutil.h" */
/* #include "infblock.h" */

/* +++ inftrees.h */
/*
 * inftrees.h -- header to use inftrees.c
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 * WARNING: this file should *not* be used by applications. It is part
 * of the implementation of the compression library and is subject to
 * change. Applications should only use zlib.h.
 */

/*
 * Huffman code lookup table entry--this entry is four bytes for
 * machines that have 16-bit pointers (e.g. PC's in the small or
 * medium model).
 */

typedef struct inflate_huft_s FAR inflate_huft;

struct inflate_huft_s {
	union {
		struct {
			Byte Exop;	/* number of extra bits or operation */
			/* number of bits in this code or subcode */
			Byte Bits;
		} what;
		Bytef *pad;	/* pad structure to a power of 2 (4 bytes for */
	} word;	/*  16-bit, 8 bytes for 32-bit machines) */
	/* literal, length base, distance base, or table offset */
	uInt base;
};

/*
 * Maximum size of dynamic tree.  The maximum found in a long but non-
 * exhaustive search was 1004 huft structures (850 for length/literals
 * and 154 for distances, the latter actually the result of an
 * exhaustive search).  The actual maximum is not known, but the value
 * below is more than safe.
 */
#define	MANY 1440

extern int inflate_trees_bits OF((
    uIntf *,			/* 19 code lengths */
    uIntf *,			/* bits tree desired/actual depth */
    inflate_huft * FAR *,	/* bits tree result */
    inflate_huft *,		/* space for trees */
    z_streamp));	/* for zalloc, zfree functions */

extern int inflate_trees_dynamic OF((
    uInt,	/* number of literal/length codes */
    uInt,	/* number of distance codes */
    uIntf *,	/* that many (total) code lengths */
    uIntf *,	/* literal desired/actual bit depth */
    uIntf *,	/* distance desired/actual bit depth */
    inflate_huft * FAR *,	/* literal/length tree result */
    inflate_huft * FAR *,	/* distance tree result */
    inflate_huft *,		/* space for trees */
    z_streamp));	/* for zalloc, zfree functions */

extern int inflate_trees_fixed OF((
    uIntf *,	/* literal desired/actual bit depth */
    uIntf *,	/* distance desired/actual bit depth */
    const inflate_huft * FAR *,	/* literal/length tree result */
    const inflate_huft * FAR *,	/* distance tree result */
    z_streamp));

/* --- inftrees.h */

/* +++ infcodes.h */
/*
 * infcodes.h -- header to use infcodes.c
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 * WARNING: this file should *not* be used by applications. It is part
 * of the implementation of the compression library and is subject to
 * change. Applications should only use zlib.h.
 */

struct inflate_codes_state;
typedef struct inflate_codes_state FAR inflate_codes_statef;

extern inflate_codes_statef *inflate_codes_new OF((
    uInt, uInt,
    const inflate_huft *, const inflate_huft *,
    z_streamp));

extern int inflate_codes OF((
    inflate_blocks_statef *,
    z_streamp,
    int));

extern void inflate_codes_free OF((
    inflate_codes_statef *,
    z_streamp));

/* --- infcodes.h */

/* +++ infutil.h */
/*
 * infutil.h -- types and macros common to blocks and codes
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 * WARNING: this file should *not* be used by applications. It is part
 * of the implementation of the compression library and is subject to
 * change. Applications should only use zlib.h.
 */

#ifndef _INFUTIL_H
#define	_INFUTIL_H

typedef enum {
	TYPE,	/* get type bits (3, including end bit) */
	LENS,	/* get lengths for stored */
	STORED,	/* processing stored block */
	TABLE,	/* get table lengths */
	BTREE,	/* get bit lengths tree for a dynamic block */
	DTREE,	/* get length, distance trees for a dynamic block */
	CODES,	/* processing fixed or dynamic block */
	DRY,	/* output remaining window bytes */
	DONEB,	/* finished last block, done */
	BADB}	/* got a data error--stuck here */
inflate_block_mode;

/* inflate blocks semi-private state */
struct inflate_blocks_state {

	/* mode */
	inflate_block_mode  mode;	/* current inflate_block mode */

	/* mode dependent information */
	union {
		uInt left;	/* if STORED, bytes left to copy */
		struct {
			uInt table;	/* table lengths (14 bits) */
			uInt index;	/* index into blens (or border) */
			uIntf *blens;	/* bit lengths of codes */
			uInt bb;	/* bit length tree depth */
			inflate_huft *tb;	/* bit length decoding tree */
		} trees;	/* if DTREE, decoding info for trees */
		struct {
			inflate_codes_statef *codes;
		} decode;	/* if CODES, current state */
	} sub;	/* submode */
	uInt last;	/* true if this block is the last block */

	/* mode independent information */
	uInt bitk;	/* bits in bit buffer */
	uLong bitb;	/* bit buffer */
	inflate_huft *hufts;  /* single malloc for tree space */
	Bytef *window;	/* sliding window */
	Bytef *end;	/* one byte after sliding window */
	Bytef *read;	/* window read pointer */
	Bytef *write;	/* window write pointer */
	check_func checkfn;	/* check function */
	uLong check;	/* check on output */

};


/* defines for inflate input/output */
/*   update pointers and return */
#define	UPDBITS {s->bitb = b; s->bitk = k; }
#define	UPDIN {z->avail_in = n; z->total_in += p-z->next_in; z->next_in = p; }
#define	UPDOUT {s->write = q; }
#define	UPDATE {UPDBITS UPDIN UPDOUT}
#define	LEAVE {UPDATE return (inflate_flush(s, z, r)); }
/*   get bytes and bits */
#define	LOADIN {p = z->next_in; n = z->avail_in; b = s->bitb; k = s->bitk; }
#define	NEEDBYTE { if (n) r = Z_OK; else LEAVE }
#define	NEXTBYTE (n--, *p++)
#define	NEEDBITS(j) { while (k < (j)) { NEEDBYTE; b |= ((uLong)NEXTBYTE)<<k; \
	k += 8; }}
#define	DUMPBITS(j) {b >>= (j); k -= (j); }
/*   output bytes */
#define	WAVAIL (uInt)(q < s->read ? s->read-q-1 : s->end-q)
#define	LOADOUT {q = s->write; m = (uInt)WAVAIL; }
#define	WWRAP {if (q == s->end && s->read != s->window) {q = s->window; \
	m = (uInt)WAVAIL; }}
#define	FLUSH {UPDOUT r = inflate_flush(s, z, r); LOADOUT}
#define	NEEDOUT {if (m == 0) {WWRAP if (m == 0) { FLUSH WWRAP \
	if (m == 0) LEAVE }} r = Z_OK; }
#define	OUTBYTE(a) {*q++ = (Byte)(a); m--; }
/*   load local pointers */
#define	LOAD {LOADIN LOADOUT}

/* masks for lower bits (size given to avoid silly warnings with Visual C++) */
extern uInt inflate_mask[17];

/* copy as much as possible from the sliding window to the output area */
extern int inflate_flush OF((
    inflate_blocks_statef *,
    z_streamp,
    int));

#ifndef NO_DUMMY_DECL
struct internal_state {int dummy; };	/* for buggy compilers */
#endif

#endif
/* --- infutil.h */

#ifndef NO_DUMMY_DECL
struct inflate_codes_state {int dummy; };	/* for buggy compilers */
#endif

/* Table for deflate from PKZIP's appnote.txt. */
local const uInt border[] = { /* Order of the bit length code lengths */
	16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};

/*
 * Notes beyond the 1.93a appnote.txt:
 *
 *   1. Distance pointers never point before the beginning of the output
 *      stream.
 *   2. Distance pointers can point back across blocks, up to 32k away.
 *   3. There is an implied maximum of 7 bits for the bit length table and
 *      15 bits for the actual data.
 *   4. If only one code exists, then it is encoded using one bit.  (Zero
 *      would be more efficient, but perhaps a little confusing.)  If two
 *      codes exist, they are coded using one bit each (0 and 1).
 *   5. There is no way of sending zero distance codes--a dummy must be
 *      sent if there are none.  (History: a pre 2.0 version of PKZIP would
 *      store blocks with no distance codes, but this was discovered to be
 *      too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow
 *      zero distance codes, which is sent as one code of zero bits in
 *      length.
 *   6. There are up to 286 literal/length codes.  Code 256 represents the
 *      end-of-block.  Note however that the static length tree defines
 *      288 codes just to fill out the Huffman codes.  Codes 286 and 287
 *      cannot be used though, since there is no length base or extra bits
 *      defined for them.  Similarily, there are up to 30 distance codes.
 *      However, static trees define 32 codes (all 5 bits) to fill out the
 *      Huffman codes, but the last two had better not show up in the data.
 *   7. Unzip can check dynamic Huffman blocks for complete code sets.
 *      The exception is that a single code would not be complete (see #4).
 *   8. The five bits following the block type is really the number of
 *      literal codes sent minus 257.
 *   9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
 *      (1+6+6).  Therefore, to output three times the length, you output
 *      three codes (1+1+1), whereas to output four times the same length,
 *      you only need two codes (1+3).  Hmm.
 *  10. In the tree reconstruction algorithm, Code = Code + Increment
 *      only if BitLength(i) is not zero.  (Pretty obvious.)
 *  11. Correction: 4 Bits: #of Bit Length codes - 4     (4 - 19)
 *  12. Note: length code 284 can represent 227-258, but length code 285
 *      really is 258.  The last length deserves its own, short code
 *      since it gets used a lot in very redundant files.  The length
 *      258 is special since 258 - 3 (the min match length) is 255.
 *  13. The literal/length and distance code bit lengths are read as a
 *      single stream of lengths.  It is possible (and advantageous) for
 *      a repeat code (16, 17, or 18) to go across the boundary between
 *      the two sets of lengths.
 */


void
inflate_blocks_reset(s, z, c)
inflate_blocks_statef *s;
z_streamp z;
uLongf *c;
{
	if (c != Z_NULL)
		*c = s->check;
	if ((s->mode == BTREE || s->mode == DTREE) &&
	    s->sub.trees.blens != Z_NULL) {
		ZFREE(z, s->sub.trees.blens);
		s->sub.trees.blens = Z_NULL;
	}
	if (s->mode == CODES && s->sub.decode.codes != Z_NULL) {
		(void) inflate_codes_free(s->sub.decode.codes, z);
		s->sub.decode.codes = Z_NULL;
	}
	s->mode = TYPE;
	s->bitk = 0;
	s->bitb = 0;
	s->read = s->write = s->window;
	if (s->checkfn != Z_NULL)
		z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
	Trace((stderr, "inflate:   blocks reset\n"));
}

inflate_blocks_statef *
inflate_blocks_new(z, c, w)
z_streamp z;
check_func c;
uInt w;
{
	inflate_blocks_statef *s;

	if ((s = (inflate_blocks_statef *)ZALLOC
	    (z, 1, sizeof (struct inflate_blocks_state))) == Z_NULL)
		return (s);
	s->hufts = (inflate_huft *)ZALLOC(z, MANY, sizeof (inflate_huft));
	if (s->hufts == Z_NULL) {
		ZFREE(z, s);
		return (Z_NULL);
	}
	if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
	{
		ZFREE(z, s->hufts);
		ZFREE(z, s);
		return (Z_NULL);
	}
	s->end = s->window + w;
	s->checkfn = c;
	s->mode = TYPE;
	Trace((stderr, "inflate:   blocks allocated\n"));
	inflate_blocks_reset(s, z, Z_NULL);
	return (s);
}


int
inflate_blocks(s, z, r)
inflate_blocks_statef *s;
z_streamp z;
int r;
{
	uInt t;	/* temporary storage */
	uLong b;	/* bit buffer */
	uInt k;	/* bits in bit buffer */
	Bytef *p;	/* input data pointer */
	uInt n;	/* bytes available there */
	Bytef *q;	/* output window write pointer */
	uInt m;	/* bytes to end of window or read pointer */

	/* copy input/output information to locals (UPDATE macro restores) */
	LOAD;

	/* process input based on current state */
	/* CONSTCOND */
	while (1)
		switch (s->mode)
	{
	case TYPE:
		NEEDBITS(3);
		t = (uInt)b & 7;
		s->last = t & 1;
		switch (t >> 1)
		{
		case 0:			/* stored */
			Trace((stderr, "inflate:     stored block%s\n",
			    s->last ? " (last)" : ""));
			DUMPBITS(3);
			t = k & 7;	/* go to byte boundary */
			DUMPBITS(t);
			s->mode = LENS;	/* get length of stored block */
			break;
		case 1:			/* fixed */
			Trace((stderr, "inflate:     fixed codes block%s\n",
			    s->last ? " (last)" : ""));
			{
				uInt bl, bd;
				const inflate_huft *tl, *td;

				(void) inflate_trees_fixed(&bl, &bd, &tl, &td,
				    z);
				s->sub.decode.codes = inflate_codes_new(bl,
				    bd, tl, td, z);
				if (s->sub.decode.codes == Z_NULL)
				{
					r = Z_MEM_ERROR;
					LEAVE
				}
			}
			DUMPBITS(3);
			s->mode = CODES;
			break;
		case 2:			/* dynamic */
			Trace((stderr, "inflate:     dynamic codes block%s\n",
			    s->last ? " (last)" : ""));
			DUMPBITS(3);
			s->mode = TABLE;
			break;
		case 3:			/* illegal */
			DUMPBITS(3);
			s->mode = BADB;
			z->msg = "invalid block type";
			r = Z_DATA_ERROR;
			LEAVE
		}
		break;
	case LENS:
		NEEDBITS(32);
		if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
		{
			s->mode = BADB;
			z->msg = "invalid stored block lengths";
			r = Z_DATA_ERROR;
			LEAVE
		}
		s->sub.left = (uInt)b & 0xffff;
		b = k = 0;	/* dump bits */
		Tracev((stderr, "inflate:       stored length %u\n",
		    s->sub.left));
		s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
		break;
	case STORED:
		if (n == 0)
			LEAVE
		NEEDOUT;
		t = s->sub.left;
		if (t > n) t = n;
		if (t > m) t = m;
		zmemcpy(q, p, t);
		p += t;  n -= t;
		q += t;  m -= t;
		if ((s->sub.left -= t) != 0)
			break;
		Tracev((stderr,
		    "inflate:       stored end, %lu total out\n",
		    z->total_out + (q >= s->read ? q - s->read :
			(s->end - s->read) + (q - s->window))));
		s->mode = s->last ? DRY : TYPE;
		break;
	case TABLE:
		NEEDBITS(14);
		s->sub.trees.table = t = (uInt)b & 0x3fff;
#ifndef PKZIP_BUG_WORKAROUND
		if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
		{
			s->mode = BADB;
			z->msg =
			    (char *)"too many length or distance symbols";
			r = Z_DATA_ERROR;
			LEAVE
		}
#endif
		t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
		/* if (t < 19) t = 19; */
		if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t,
		    sizeof (uInt))) == Z_NULL)
		{
			r = Z_MEM_ERROR;
			LEAVE
		}
		DUMPBITS(14);
		s->sub.trees.index = 0;
		Tracev((stderr, "inflate:       table sizes ok\n"));
		s->mode = BTREE;
		/* FALLTHRU */
	case BTREE:
		while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
		{
			NEEDBITS(3);
			s->sub.trees.blens[border[s->sub.trees.index++]] =
			    (uInt)b & 7;
			DUMPBITS(3);
		}
		while (s->sub.trees.index < 19)
			s->sub.trees.blens[border[s->sub.trees.index++]] =
			    0;
		s->sub.trees.bb = 7;
		t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
		    &s->sub.trees.tb, s->hufts, z);
		if (t != Z_OK)
		{
			ZFREE(z, s->sub.trees.blens);
			s->sub.trees.blens = Z_NULL;
			r = t;
			if (r == Z_DATA_ERROR)
				s->mode = BADB;
			LEAVE
		}
		s->sub.trees.index = 0;
		Tracev((stderr, "inflate:       bits tree ok\n"));
		s->mode = DTREE;
		/* FALLTHRU */
	case DTREE:
		while (t = s->sub.trees.table,
		    s->sub.trees.index < 258 + (t & 0x1f) +
		    ((t >> 5) & 0x1f))
		{
			inflate_huft *h;
			uInt i, j, c;

			t = s->sub.trees.bb;
			NEEDBITS(t);
			h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
			t = h->word.what.Bits;
			c = h->base;
			if (c < 16)
			{
				DUMPBITS(t);
				s->sub.trees.blens[s->sub.trees.index++] =
				    c;
			} else { /* c == 16..18 */
				i = c == 18 ? 7 : c - 14;
				j = c == 18 ? 11 : 3;
				NEEDBITS(t + i);
				DUMPBITS(t);
				j += (uInt)b & inflate_mask[i];
				DUMPBITS(i);
				i = s->sub.trees.index;
				t = s->sub.trees.table;
				if (i + j > 258 + (t & 0x1f) +
				    ((t >> 5) & 0x1f) ||
				    (c == 16 && i < 1))
				{
					ZFREE(z, s->sub.trees.blens);
					s->sub.trees.blens = Z_NULL;
					s->mode = BADB;
					z->msg = "invalid bit length repeat";
					r = Z_DATA_ERROR;
					LEAVE
				}
				c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
				do {
					s->sub.trees.blens[i++] = c;
				} while (--j);
				s->sub.trees.index = i;
			}
		}
		s->sub.trees.tb = Z_NULL;
		{
			uInt bl, bd;
			inflate_huft *tl, *td;
			inflate_codes_statef *c;

				/* must be <= 9 for lookahead assumptions */
			bl = 9;
				/* must be <= 9 for lookahead assumptions */
			bd = 6;
			t = s->sub.trees.table;
			t = inflate_trees_dynamic(257 + (t & 0x1f),
			    1 + ((t >> 5) & 0x1f),
			    s->sub.trees.blens, &bl, &bd, &tl, &td,
			    s->hufts, z);
			ZFREE(z, s->sub.trees.blens);
			s->sub.trees.blens = Z_NULL;
			if (t != Z_OK)
			{
				if (t == (uInt)Z_DATA_ERROR)
					s->mode = BADB;
				r = t;
				LEAVE
			}
			Tracev((stderr, "inflate:       trees ok\n"));
			if ((c = inflate_codes_new(bl, bd, tl, td, z)) ==
			    Z_NULL)
			{
				r = Z_MEM_ERROR;
				LEAVE
			}
			s->sub.decode.codes = c;
		}
		s->mode = CODES;
		/* FALLTHRU */
	case CODES:
		UPDATE;
		if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
			return (inflate_flush(s, z, r));
		r = Z_OK;
		(void) inflate_codes_free(s->sub.decode.codes, z);
		LOAD;
		Tracev((stderr, "inflate:       codes end, %lu total out\n",
		    z->total_out + (q >= s->read ? q - s->read :
			(s->end - s->read) + (q - s->window))));
		if (!s->last)
		{
			s->mode = TYPE;
			break;
		}
		s->mode = DRY;
		/* FALLTHRU */
	case DRY:
		FLUSH;
		if (s->read != s->write)
			LEAVE
		s->mode = DONEB;
		/* FALLTHRU */
	case DONEB:
		r = Z_STREAM_END;
		LEAVE
	case BADB:
		r = Z_DATA_ERROR;
		LEAVE
	default:
		r = Z_STREAM_ERROR;
		LEAVE
	}
	/* NOTREACHED */
	/* otherwise lint complains */
}


int
inflate_blocks_free(s, z)
inflate_blocks_statef *s;
z_streamp z;
{
	inflate_blocks_reset(s, z, Z_NULL);
	ZFREE(z, s->window);
	s->window = Z_NULL;
	ZFREE(z, s->hufts);
	s->hufts = Z_NULL;
	ZFREE(z, s);
	Trace((stderr, "inflate:   blocks freed\n"));
	return (Z_OK);
}


void
inflate_set_dictionary(s, d, n)
inflate_blocks_statef *s;
const Bytef *d;
uInt  n;
{
	Assert(s->window + n <= s->end, "set dict");
	zmemcpy((charf *)s->window, d, n);
	s->read = s->write = s->window + n;
}

/*
 * Returns true if inflate is currently at the end of a block
 * generated by Z_SYNC_FLUSH or Z_FULL_FLUSH.
 * IN assertion: s != Z_NULL
 */
int
inflate_blocks_sync_point(s)
inflate_blocks_statef *s;
{
	return (s->mode == LENS);
}

/*
 * This subroutine adds the data at next_in/avail_in to the output history
 * without performing any output.  The output buffer must be "caught up";
 * i.e. no pending output (hence s->read equals s->write), and the state must
 * be BLOCKS (i.e. we should be willing to see the start of a series of
 * BLOCKS).  On exit, the output will also be caught up, and the checksum
 * will have been updated if need be.
 */
int
inflate_addhistory(s, z)
inflate_blocks_statef *s;
z_stream *z;
{
	uLong b;	/* bit buffer */  /* NOT USED HERE */
	uInt k;	/* bits in bit buffer */ /* NOT USED HERE */
	uInt t;	/* temporary storage */
	Bytef *p;	/* input data pointer */
	uInt n;	/* bytes available there */
	Bytef *q;	/* output window write pointer */
	uInt m;	/* bytes to end of window or read pointer */

	if (s->read != s->write)
		return (Z_STREAM_ERROR);
	if (s->mode != TYPE)
		return (Z_DATA_ERROR);

	/* we're ready to rock */
	LOAD;
	/*
	 * while there is input ready, copy to output buffer, moving
	 * pointers as needed.
	 */
	while (n) {
		t = n;	/* how many to do */
		/* is there room until end of buffer? */
		if (t > m) t = m;
		/* update check information */
		if (s->checkfn != Z_NULL)
			s->check = (*s->checkfn)(s->check, q, t);
		zmemcpy(q, p, t);
		q += t;
		p += t;
		n -= t;
		z->total_out += t;
		s->read = q;	/* drag read pointer forward */
/* WWRAP */	/* expand WWRAP macro by hand to handle s->read */
		if (q == s->end) {
			s->read = q = s->window;
			m = WAVAIL;
		}
	}
	UPDATE;
	return (Z_OK);
}


/*
 * At the end of a Deflate-compressed PPP packet, we expect to have seen
 * a `stored' block type value but not the (zero) length bytes.
 */
int
inflate_packet_flush(s)
    inflate_blocks_statef *s;
{
	if (s->mode != LENS)
		return (Z_DATA_ERROR);
	s->mode = TYPE;
	return (Z_OK);
}
/* --- infblock.c */

/* +++ inftrees.c */
/*
 * inftrees.c -- generate Huffman trees for efficient decoding
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* #include "zutil.h" */
/* #include "inftrees.h" */

const char inflate_copyright[] =
" inflate 1.1.3 Copyright 1995-1998 Mark Adler ";
/*
 * If you use the zlib library in a product, an acknowledgment is
 * welcome in the documentation of your product. If for some reason
 * you cannot include such an acknowledgment, I would appreciate that
 * you keep this copyright string in the executable of your product.
 */

#ifndef NO_DUMMY_DECL
struct internal_state  {int dummy; };	/* for buggy compilers */
#endif

/* simplify the use of the inflate_huft type with some defines */
#define	exop word.what.Exop
#define	bits word.what.Bits


local int huft_build OF((
	uIntf *,	/* code lengths in bits */
	uInt,		/* number of codes */
	uInt,		/* number of "simple" codes */
	const uIntf *,	/* list of base values for non-simple codes */
	const uIntf *,	/* list of extra bits for non-simple codes */
	inflate_huft * FAR*, /* result: starting table */
	uIntf *,	/* maximum lookup bits (returns actual) */
	inflate_huft *hp,	/* space for trees */
	uInt *hn,	/* hufts used in space */
	uIntf *v));	/* working area: values in order of bit length */

/* Tables for deflate from PKZIP's appnote.txt. */
local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
	3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
	35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
	/* see note #13 above about 258 */
local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
	3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112};
	/* 112==invalid */
local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
	1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
	257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
	8193, 12289, 16385, 24577};
local const uInt cpdext[30] = { /* Extra bits for distance codes */
	0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
	7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
	12, 12, 13, 13};

/*
 * Huffman code decoding is performed using a multi-level table
 * lookup.  The fastest way to decode is to simply build a lookup
 * table whose size is determined by the longest code.  However, the
 * time it takes to build this table can also be a factor if the data
 * being decoded is not very long.  The most common codes are
 * necessarily the shortest codes, so those codes dominate the
 * decoding time, and hence the speed.  The idea is you can have a
 * shorter table that decodes the shorter, more probable codes, and
 * then point to subsidiary tables for the longer codes.  The time it
 * costs to decode the longer codes is then traded against the time it
 * takes to make longer tables.
 *
 * This results of this trade are in the variables lbits and dbits
 * below.  lbits is the number of bits the first level table for
 * literal/ length codes can decode in one step, and dbits is the same
 * thing for the distance codes.  Subsequent tables are also less than
 * or equal to those sizes.  These values may be adjusted either when
 * all of the codes are shorter than that, in which case the longest
 * code length in bits is used, or when the shortest code is *longer*
 * than the requested table size, in which case the length of the
 * shortest code in bits is used.
 *
 * There are two different values for the two tables, since they code
 * a different number of possibilities each.  The literal/length table
 * codes 286 possible values, or in a flat code, a little over eight
 * bits.  The distance table codes 30 possible values, or a little
 * less than five bits, flat.  The optimum values for speed end up
 * being about one bit more than those, so lbits is 8+1 and dbits is
 * 5+1.  The optimum values may differ though from machine to machine,
 * and possibly even between compilers.  Your mileage may vary.
 */


/* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
#define	BMAX 15		/* maximum bit length of any code */


local int
huft_build(b, n, s, d, e, t, m, hp, hn, v)
uIntf *b;	/* code lengths in bits (all assumed <= BMAX) */
uInt n;	/* number of codes (assumed <= 288) */
uInt s;	/* number of simple-valued codes (0..s-1) */
const uIntf *d;	/* list of base values for non-simple codes */
const uIntf *e;	/* list of extra bits for non-simple codes */
inflate_huft * FAR *t;	/* result: starting table */
uIntf *m;	/* maximum lookup bits, returns actual */
inflate_huft *hp;	/* space for trees */
uInt *hn;		/* hufts used in space */
uIntf *v;		/* working area: values in order of bit length */
/*
 * Given a list of code lengths and a maximum table size, make a set
 * of tables to decode that set of codes.  Return Z_OK on success,
 * Z_BUF_ERROR if the given code set is incomplete (the tables are
 * still built in this case), Z_DATA_ERROR if the input is invalid (an
 * over-subscribed set of lengths), or Z_MEM_ERROR if not enough
 * memory.
 */
{

	uInt a;	/* counter for codes of length k */
	uInt c[BMAX+1];	/* bit length count table */
	uInt f;	/* i repeats in table every f entries */
	int g;	/* maximum code length */
	int h;	/* table level */
	register uInt i;	/* counter, current code */
	register uInt j;	/* counter */
	register int k;	/* number of bits in current code */
	int l;	/* bits per table (returned in m) */
	register uIntf *p;	/* pointer into c[], b[], or v[] */
	inflate_huft *q;	/* points to current table */
	struct inflate_huft_s r; /* table entry for structure assignment */
	inflate_huft *u[BMAX];	/* table stack */
	uInt mask;	/* (1 << w) - 1, to avoid cc -O bug on HP */
	register int w;	/* bits before this table == (l * h) */
	uInt x[BMAX+1];	/* bit offsets, then code stack */
	uIntf *xp;	/* pointer into x */
	int y;	/* number of dummy codes added */
	uInt z;	/* number of entries in current table */

	(void) inflate_copyright;
	/* Generate counts for each bit length */
	p = c;
#define	C0 *p++ = 0;
#define	C2 C0 C0 C0 C0
#define	C4 C2 C2 C2 C2
	C4	/* clear c[]--assume BMAX+1 is 16 */
	    p = b;  i = n;
	do {
		c[*p++]++;	/* assume all entries <= BMAX */
	} while (--i);
	if (c[0] == n)		/* null input--all zero length codes */
	{
		*t = (inflate_huft *)Z_NULL;
		*m = 0;
		return (Z_OK);
	}


	/* Find minimum and maximum length, bound *m by those */
	l = *m;
	for (j = 1; j <= BMAX; j++)
		if (c[j])
			break;
	k = j;	/* minimum code length */
	if ((uInt)l < j)
		l = j;
	for (i = BMAX; i; i--)
		if (c[i])
			break;
	g = i;	/* maximum code length */
	if ((uInt)l > i)
		l = i;
	*m = l;


	/* Adjust last length count to fill out codes, if needed */
	for (y = 1 << j; j < i; j++, y <<= 1)
		if ((y -= c[j]) < 0)
			return (Z_DATA_ERROR);
	if ((y -= c[i]) < 0)
		return (Z_DATA_ERROR);
	c[i] += y;


	/* Generate starting offsets into the value table for each length */
	x[1] = j = 0;
	p = c + 1;  xp = x + 2;
	while (--i) {		/* note that i == g from above */
		*xp++ = (j += *p++);
	}


	/* Make a table of values in order of bit lengths */
	p = b;  i = 0;
	do {
		if ((j = *p++) != 0)
			v[x[j]++] = i;
	} while (++i < n);
	n = x[g];	/* set n to length of v */


	/* Generate the Huffman codes and for each, make the table entries */
	x[0] = i = 0;	/* first Huffman code is zero */
	p = v;	/* grab values in bit order */
	h = -1;	/* no tables yet--level -1 */
	w = -l;	/* bits decoded == (l * h) */
	u[0] = (inflate_huft *)Z_NULL;	/* just to keep compilers happy */
	q = (inflate_huft *)Z_NULL;	/* ditto */
	z = 0;	/* ditto */

	/* go through the bit lengths (k already is bits in shortest code) */
	for (; k <= g; k++) {
		a = c[k];
		while (a--) {
			/*
			 * here i is the Huffman code of length k bits
			 * for value *p.  make tables up to required
			 * level.
			 */
			while (k > w + l) {
				h++;
				w += l;	/* previous table always l bits */

				/*
				 * compute minimum size table less
				 * than or equal to l bits
				 */
				z = g - w;
				/* table size upper limit */
				z = z > (uInt)l ? l : z;
				/* try a k-w bit table */
				if ((f = 1 << (j = k - w)) > a + 1) {
					/* too few codes for k-w bit table */
					/* deduct codes from patterns left */
					f -= a + 1;
					xp = c + k;
					if (j < z)
						/*
						 * try smaller tables
						 * up to z bits
						 */
						while (++j < z) {
							/*
							 * enough
							 * codes to
							 * use up j
							 * bits
							 */
							if ((f <<= 1) <= *++xp)
								break;
							f -= *xp;
							/*
							 * else deduct
							 * codes from
							 * patterns
							 */
						}
				}
				/* table entries for j-bit table */
				z = 1 << j;

				/* allocate new table */
				/* (note: doesn't matter for fixed) */
				/* not enough memory */
				if (*hn + z > MANY)
					return (Z_MEM_ERROR);
				u[h] = q = hp + *hn;
				*hn += z;

				/* connect to last table, if there is one */
				if (h) {
					/* save pattern for backing up */
					x[h] = i;
					/* bits to dump before this table */
					r.bits = (Byte)l;
					/* bits in this table */
					r.exop = (Byte)j;
					j = i >> (w - l);
					/* offset to this table */
					r.base = (uInt)(q - u[h-1] - j);
					/* connect to last table */
					u[h-1][j] = r;
				} else
					/* first table is returned result */
					*t = q;
			}

			/* set up table entry in r */
			r.bits = (Byte)(k - w);
			if (p >= v + n)
				/* out of values--invalid code */
				r.exop = 128 + 64;
			else if (*p < s)
			{
				/* 256 is end-of-block */
				r.exop = (Byte)(*p < 256 ? 0 : 32 + 64);
				/* simple code is just the value */
				r.base = *p++;
			}
			else
			{
				/* non-simple--look up in lists */
				r.exop = (Byte)(e[*p - s] + 16 + 64);
				r.base = d[*p++ - s];
			}

			/* fill code-like entries with r */
			f = 1 << (k - w);
			for (j = i >> w; j < z; j += f)
				q[j] = r;

			/* backwards increment the k-bit code i */
			for (j = 1 << (k - 1); i & j; j >>= 1)
				i ^= j;
			i ^= j;

			/* backup over finished tables */
			mask = (1 << w) - 1;	/* needed on HP, cc -O bug */
			while ((i & mask) != x[h])
			{
				h--;	/* don't need to update q */
				w -= l;
				mask = (1 << w) - 1;
			}
		}
	}


	/* Return Z_BUF_ERROR if we were given an incomplete table */
	return (y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK);
}


int
inflate_trees_bits(c, bb, tb, hp, z)
uIntf *c;	/* 19 code lengths */
uIntf *bb;	/* bits tree desired/actual depth */
inflate_huft * FAR *tb;	/* bits tree result */
inflate_huft *hp;	/* space for trees */
z_streamp z;	/* for zfree function */
{
	int r;
	uInt hn = 0;		/* hufts used in space */
	uIntf v[19];		/* work area for huft_build */

	r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb,
	    hp, &hn, v);
	if (r == Z_DATA_ERROR)
		z->msg = "oversubscribed dynamic bit lengths tree";
	else if (r == Z_BUF_ERROR || *bb == 0)
	{
		z->msg = "incomplete dynamic bit lengths tree";
		r = Z_DATA_ERROR;
	}
	return (r);
}


int
inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, hp, z)
uInt nl;	/* number of literal/length codes */
uInt nd;	/* number of distance codes */
uIntf *c;	/* that many (total) code lengths */
uIntf *bl;	/* literal desired/actual bit depth */
uIntf *bd;	/* distance desired/actual bit depth */
inflate_huft * FAR *tl;	/* literal/length tree result */
inflate_huft * FAR *td;	/* distance tree result */
inflate_huft *hp;	/* space for trees */
z_streamp z;	/* for zfree function */
{
	int r;
	uInt hn = 0;		/* hufts used in space */
	uIntf v[288];		/* work area for huft_build */

	/* build literal/length tree */
	r = huft_build(c, nl, 257, cplens, cplext, tl, bl, hp, &hn, v);
	if (r != Z_OK || *bl == 0)
	{
		if (r == Z_DATA_ERROR)
			z->msg = "oversubscribed literal/length tree";
		else if (r != Z_MEM_ERROR)
		{
			z->msg = "incomplete literal/length tree";
			r = Z_DATA_ERROR;
		}
		return (r);
	}

	/* build distance tree */
	r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, hp, &hn, v);
	if (r != Z_OK || (*bd == 0 && nl > 257))
	{
		if (r == Z_DATA_ERROR)
			z->msg = "oversubscribed distance tree";
		else if (r == Z_BUF_ERROR) {
#ifdef PKZIP_BUG_WORKAROUND
			r = Z_OK;
#else
			z->msg = "incomplete distance tree";
			r = Z_DATA_ERROR;
		} else if (r != Z_MEM_ERROR) {
			z->msg = "empty distance tree with lengths";
			r = Z_DATA_ERROR;
#endif
		}
		return (r);
	}

/* done */
	return (Z_OK);
}


/* build fixed tables only once--keep them here */
/* #define	BUILDFIXED */
#ifdef BUILDFIXED
local int fixed_built = 0;
#define	FIXEDH 544	/* number of hufts used by fixed tables */
local inflate_huft fixed_mem[FIXEDH];
local uInt fixed_bl;
local uInt fixed_bd;
local inflate_huft *fixed_tl;
local inflate_huft *fixed_td;
#else
#include "inffixed.h"
#endif

/*ARGSUSED*/
int
inflate_trees_fixed(bl, bd, tl, td, z)
uIntf *bl;	/* literal desired/actual bit depth */
uIntf *bd;	/* distance desired/actual bit depth */
const inflate_huft * FAR *tl;	/* literal/length tree result */
const inflate_huft * FAR *td;	/* distance tree result */
z_streamp z;	/* for memory allocation */
{
#ifdef BUILDFIXED
	/*
	 * build fixed tables if not already (multiple overlapped
	 * executions ok)
	 */
	if (!fixed_built)
	{
		int k;	/* temporary variable */
		uInt f = 0;	/* number of hufts used in fixed_mem */
		uIntf *c;	/* length list for huft_build */
		uIntf *v;

		/* allocate memory */
		if ((c = (uIntf*)ZALLOC(z, 288, sizeof (uInt))) == Z_NULL)
			return (Z_MEM_ERROR);
		if ((v = (uIntf*)ZALLOC(z, 288, sizeof (uInt))) == Z_NULL)
		{
			ZFREE(z, c);
			return (Z_MEM_ERROR);
		}
		/* literal table */
		for (k = 0; k < 144; k++)
			c[k] = 8;
		for (; k < 256; k++)
			c[k] = 9;
		for (; k < 280; k++)
			c[k] = 7;
		for (; k < 288; k++)
			c[k] = 8;
		fixed_bl = 9;
		(void) huft_build(c, 288, 257, cplens, cplext, &fixed_tl,
		    &fixed_bl, fixed_mem, &f, v);

		/* distance table */
		for (k = 0; k < 30; k++)
			c[k] = 5;
		fixed_bd = 5;
		(void) huft_build(c, 30, 0, cpdist, cpdext, &fixed_td,
		    &fixed_bd, fixed_mem, &f, v);

		/* done */
		ZFREE(z, v);
		ZFREE(z, c);
		fixed_built = 1;
	}
#endif
	*bl = fixed_bl;
	*bd = fixed_bd;
	*tl = fixed_tl;
	*td = fixed_td;
	return (Z_OK);
}
/* --- inftrees.c */

/* +++ infcodes.c */
/*
 * infcodes.c -- process literals and length/distance pairs
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* #include "zutil.h" */
/* #include "inftrees.h" */
/* #include "infblock.h" */
/* #include "infcodes.h" */
/* #include "infutil.h" */

/* +++ inffast.h */
/*
 * inffast.h -- header to use inffast.c
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 * WARNING: this file should *not* be used by applications. It is part
 * of the implementation of the compression library and is subject to
 * change. Applications should only use zlib.h.
 */

extern int inflate_fast OF((
    uInt,
    uInt,
    const inflate_huft *,
    const inflate_huft *,
    inflate_blocks_statef *,
    z_streamp));
/* --- inffast.h */

/* simplify the use of the inflate_huft type with some defines */
#define	exop word.what.Exop
#define	bits word.what.Bits

/* inflate codes private state */
struct inflate_codes_state {

	/* mode */
	enum {	/* waiting for "i:"=input, "o:"=output, "x:"=nothing */
		START,	/* x: set up for LEN */
		LEN,	/* i: get length/literal/eob next */
		LENEXT,	/* i: getting length extra (have base) */
		DIST,	/* i: get distance next */
		DISTEXT,	/* i: getting distance extra */
		COPY,	/* o: copying bytes in window, waiting for space */
		LIT,	/* o: got literal, waiting for output space */
		WASH,	/* o: got eob, possibly still output waiting */
		END,	/* x: got eob and all data flushed */
		BADCODE}	/* x: got error */
	mode;	/* current inflate_codes mode */

	/* mode dependent information */
	uInt len;
	union {
		struct {
			const inflate_huft *tree;	/* pointer into tree */
			uInt need;	/* bits needed */
		} code;	/* if LEN or DIST, where in tree */
		uInt lit;	/* if LIT, literal */
		struct {
			uInt get;	/* bits to get for extra */
			uInt dist;	/* distance back to copy from */
		} copy;	/* if EXT or COPY, where and how much */
	} sub;	/* submode */

	/* mode independent information */
	Byte lbits;	/* ltree bits decoded per branch */
	Byte dbits;	/* dtree bits decoder per branch */
	const inflate_huft *ltree;	/* literal/length/eob tree */
	const inflate_huft *dtree;	/* distance tree */

};


inflate_codes_statef *
inflate_codes_new(bl, bd, tl, td, z)
uInt bl, bd;
const inflate_huft *tl;
const inflate_huft *td;	/* need separate declaration for Borland C++ */
z_streamp z;
{
	inflate_codes_statef *c;

	if ((c = (inflate_codes_statef *)
	    ZALLOC(z, 1, sizeof (struct inflate_codes_state))) != Z_NULL)
	{
		c->mode = START;
		c->lbits = (Byte)bl;
		c->dbits = (Byte)bd;
		c->ltree = tl;
		c->dtree = td;
		Tracev((stderr, "inflate:       codes new\n"));
	}
	return (c);
}


int
inflate_codes(s, z, r)
inflate_blocks_statef *s;
z_streamp z;
int r;
{
	uInt j;	/* temporary storage */
	const inflate_huft *t;	/* temporary pointer */
	uInt e;	/* extra bits or operation */
	uLong b;	/* bit buffer */
	uInt k;	/* bits in bit buffer */
	Bytef *p;	/* input data pointer */
	uInt n;	/* bytes available there */
	Bytef *q;	/* output window write pointer */
	uInt m;	/* bytes to end of window or read pointer */
	Bytef *f;	/* pointer to copy strings from */
	inflate_codes_statef *c = s->sub.decode.codes;	/* codes state */

	/* copy input/output information to locals (UPDATE macro restores) */
	LOAD;

	/* process input and output based on current state */
	/* CONSTCOND */
	while (1)
		/* waiting for "i:"=input, "o:"=output, "x:"=nothing */
		switch (c->mode) {
		case START:	/* x: set up for LEN */
#ifndef SLOW
			if (m >= 258 && n >= 10)
			{
				UPDATE;
				r = inflate_fast(c->lbits, c->dbits,
				    c->ltree, c->dtree, s, z);
				LOAD;
				if (r != Z_OK) {
					c->mode = r == Z_STREAM_END ?
					    WASH : BADCODE;
					break;
				}
			}
#endif /* !SLOW */
			c->sub.code.need = c->lbits;
			c->sub.code.tree = c->ltree;
			c->mode = LEN;
			/* FALLTHRU */
		case LEN:	/* i: get length/literal/eob next */
			j = c->sub.code.need;
			NEEDBITS(j);
			t = c->sub.code.tree +
			    ((uInt)b & inflate_mask[j]);
			DUMPBITS(t->bits);
			e = (uInt)(t->exop);
			if (e == 0) {	/* literal */
				c->sub.lit = t->base;
				Tracevv((stderr, t->base >= 0x20 &&
				    t->base < 0x7f ?
				    "inflate:         literal '%c'\n" :
				    "inflate:         literal 0x%02x\n",
				    t->base));
				c->mode = LIT;
				break;
			}
			if (e & 16) {	/* length */
				c->sub.copy.get = e & 15;
				c->len = t->base;
				c->mode = LENEXT;
				break;
			}
			if ((e & 64) == 0) {	/* next table */
				c->sub.code.need = e;
				c->sub.code.tree = t + t->base;
				break;
			}
			if (e & 32) {	/* end of block */
				Tracevv((stderr,
				    "inflate:         end of block\n"));
				c->mode = WASH;
				break;
			}
			c->mode = BADCODE;	/* invalid code */
			z->msg = "invalid literal/length code";
			r = Z_DATA_ERROR;
			LEAVE
		case LENEXT:	/* i: getting length extra (have base) */
			j = c->sub.copy.get;
			NEEDBITS(j);
			c->len += (uInt)b & inflate_mask[j];
			DUMPBITS(j);
			c->sub.code.need = c->dbits;
			c->sub.code.tree = c->dtree;
			Tracevv((stderr,
			    "inflate:         length %u\n", c->len));
			c->mode = DIST;
			/* FALLTHRU */
		case DIST:	/* i: get distance next */
			j = c->sub.code.need;
			NEEDBITS(j);
			t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
			DUMPBITS(t->bits);
			e = (uInt)(t->exop);
			if (e & 16) {	/* distance */
				c->sub.copy.get = e & 15;
				c->sub.copy.dist = t->base;
				c->mode = DISTEXT;
				break;
			}
			if ((e & 64) == 0) {	/* next table */
				c->sub.code.need = e;
				c->sub.code.tree = t + t->base;
				break;
			}
			c->mode = BADCODE;	/* invalid code */
			z->msg = "invalid distance code";
			r = Z_DATA_ERROR;
			LEAVE
		case DISTEXT:	/* i: getting distance extra */
			j = c->sub.copy.get;
			NEEDBITS(j);
			c->sub.copy.dist += (uInt)b & inflate_mask[j];
			DUMPBITS(j);
			Tracevv((stderr,
			    "inflate:         distance %u\n",
			    c->sub.copy.dist));
			c->mode = COPY;
			/* FALLTHRU */
		case COPY:
			/* o: copying bytes in window, waiting for space */
#ifndef __TURBOC__ /* Turbo C bug for following expression */
			f = (uInt)(q - s->window) < c->sub.copy.dist ?
			    s->end - (c->sub.copy.dist - (q - s->window)) :
				q - c->sub.copy.dist;
#else
			f = q - c->sub.copy.dist;
			if ((uInt)(q - s->window) < c->sub.copy.dist)
				f = s->end - (c->sub.copy.dist -
				    (uInt)(q - s->window));
#endif
			while (c->len)
			{
				NEEDOUT;
				OUTBYTE(*f++);
				if (f == s->end)
					f = s->window;
				c->len--;
			}
			c->mode = START;
			break;
		case LIT:	/* o: got literal, waiting for output space */
			NEEDOUT;
			OUTBYTE(c->sub.lit);
			c->mode = START;
			break;
		case WASH:	/* o: got eob, possibly more output */
			if (k > 7) {	/* return unused byte, if any */
				Assert(k < 16,
				    "inflate_codes grabbed too many bytes");
				k -= 8;
				n++;
				p--;	/* can always return one */
			}
			FLUSH;
			if (s->read != s->write)
				LEAVE
			c->mode = END;
			/* FALLTHRU */
		case END:
			r = Z_STREAM_END;
			LEAVE
		case BADCODE:	/* x: got error */
			r = Z_DATA_ERROR;
			LEAVE
		default:
			r = Z_STREAM_ERROR;
			LEAVE
		}
	/* NOTREACHED */
	/* otherwise lint complains */
}


void
inflate_codes_free(c, z)
inflate_codes_statef *c;
z_streamp z;
{
	ZFREE(z, c);
	Tracev((stderr, "inflate:       codes free\n"));
}
/* --- infcodes.c */

/* +++ infutil.c */
/*
 * inflate_util.c -- data and routines common to blocks and codes
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* #include "zutil.h" */
/* #include "infblock.h" */
/* #include "inftrees.h" */
/* #include "infcodes.h" */
/* #include "infutil.h" */

#ifndef NO_DUMMY_DECL
struct inflate_codes_state {int dummy; };	/* for buggy compilers */
#endif

/* And'ing with mask[n] masks the lower n bits */
uInt inflate_mask[17] = {
	0x0000,
	0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
	0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
};


/* copy as much as possible from the sliding window to the output area */
int
inflate_flush(s, z, r)
inflate_blocks_statef *s;
z_streamp z;
int r;
{
	uInt n;
	Bytef *p;
	Bytef *q;

	/* local copies of source and destination pointers */
	p = z->next_out;
	q = s->read;

	/* compute number of bytes to copy as far as end of window */
	n = (uInt)((q <= s->write ? s->write : s->end) - q);
	if (n > z->avail_out) n = z->avail_out;
	if (n && r == Z_BUF_ERROR) r = Z_OK;

	/* update counters */
	z->avail_out -= n;
	z->total_out += n;

	/* update check information */
	if (s->checkfn != Z_NULL)
		z->adler = s->check = (*s->checkfn)(s->check, q, n);

	/* copy as far as end of window */
	if (p != Z_NULL) {	/* PPP */
		zmemcpy(p, q, n);
		p += n;
	}	/* PPP */
	q += n;

	/* see if more to copy at beginning of window */
	if (q == s->end)
	{
		/* wrap pointers */
		q = s->window;
		if (s->write == s->end)
			s->write = s->window;

		/* compute bytes to copy */
		n = (uInt)(s->write - q);
		if (n > z->avail_out) n = z->avail_out;
		if (n && r == Z_BUF_ERROR) r = Z_OK;

		/* update counters */
		z->avail_out -= n;
		z->total_out += n;

		/* update check information */
		if (s->checkfn != Z_NULL)
			z->adler = s->check = (*s->checkfn)(s->check, q, n);

		/* copy */
		if (p != Z_NULL) {	/* PPP */
			zmemcpy(p, q, n);
			p += n;
		}	/* PPP */
		q += n;
	}

	/* update pointers */
	z->next_out = p;
	s->read = q;

	/* done */
	return (r);
}
/* --- infutil.c */

/* +++ inffast.c */
/*
 * inffast.c -- process literals and length/distance pairs fast
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* #include "zutil.h" */
/* #include "inftrees.h" */
/* #include "infblock.h" */
/* #include "infcodes.h" */
/* #include "infutil.h" */
/* #include "inffast.h" */

#ifndef NO_DUMMY_DECL
struct inflate_codes_state {int dummy; };	/* for buggy compilers */
#endif

/* simplify the use of the inflate_huft type with some defines */
#define	exop word.what.Exop
#define	bits word.what.Bits

/* macros for bit input with no checking and for returning unused bytes */
#define	GRABBITS(j) { while (k < (j)) {b |= ((uLong)NEXTBYTE)<<k; k += 8; }}
#define	UNGRAB {c = z->avail_in-n; c = (k>>3) < c?k>>3:c; n += c; p -= c; \
	k -= c<<3; }

/*
 * Called with number of bytes left to write in window at least 258
 * (the maximum string length) and number of input bytes available at
 * least ten.  The ten bytes are six bytes for the longest length/
 * distance pair plus four bytes for overloading the bit buffer.
 */

int
inflate_fast(bl, bd, tl, td, s, z)
uInt bl, bd;
const inflate_huft *tl;
const inflate_huft *td;	/* need separate declaration for Borland C++ */
inflate_blocks_statef *s;
z_streamp z;
{
	const inflate_huft *t;	/* temporary pointer */
	uInt e;	/* extra bits or operation */
	uLong b;	/* bit buffer */
	uInt k;	/* bits in bit buffer */
	Bytef *p;	/* input data pointer */
	uInt n;	/* bytes available there */
	Bytef *q;	/* output window write pointer */
	uInt m;	/* bytes to end of window or read pointer */
	uInt ml;	/* mask for literal/length tree */
	uInt md;	/* mask for distance tree */
	uInt c;	/* bytes to copy */
	uInt d;	/* distance back to copy from */
	Bytef *r;	/* copy source pointer */

	/* load input, output, bit values */
	LOAD;

	/* initialize masks */
	ml = inflate_mask[bl];
	md = inflate_mask[bd];

	/* do until not enough input or output space for fast loop */
	do {	/* assume called with m >= 258 && n >= 10 */
		/* get literal/length code */
		/* max bits for literal/length code */
		GRABBITS(20);
		if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) {
			DUMPBITS(t->bits);
			Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
			    "inflate:         * literal '%c'\n" :
			    "inflate:         * literal 0x%02x\n", t->base));
			*q++ = (Byte)t->base;
			m--;
			continue;
		}
		do {
			DUMPBITS(t->bits);
			if (e & 16) {
				/* get extra bits for length */
				e &= 15;
				c = t->base + ((uInt)b & inflate_mask[e]);
				DUMPBITS(e);
				Tracevv((stderr,
				    "inflate:         * length %u\n", c));

				/* decode distance base of block to copy */
				GRABBITS(15);	/* max bits for distance code */
				e = (t = td + ((uInt)b & md))->exop;
				do {
					DUMPBITS(t->bits);
					if (e & 16) {
						/*
						 * get extra bits to
						 * add to distance
						 * base
						 */
						e &= 15;
						/* get extra bits (up to 13) */
						GRABBITS(e);
						d = t->base + ((uInt)b &
						    inflate_mask[e]);
						DUMPBITS(e);
						Tracevv((stderr,
						    "inflate:         * "
						    "distance %u\n", d));

						/* do the copy */
						m -= c;
						/* offset before dest */
						if ((uInt)(q - s->window) >= d)
							/*  just copy */
						{
							r = q - d;
							/*
							 * minimum
							 * count is
							 * three, so
							 * unroll loop
							 * a little
							 */
							*q++ = *r++;  c--;
							*q++ = *r++;  c--;
						}
					/* else offset after destination */
						else {
	/* bytes from offset to end */
							e = d - (uInt)(q -
							    s->window);
	/* pointer to offset */
							r = s->end - e;
							/* if source crosses */
							if (c > e) {
	/* copy to end of window */
								c -= e;
								do {
									*q++ =
									    *r
									    ++;
								} while (--e);
	/* copy rest from start of window */
								r = s->window;
							}
						}
						/* copy all or what's left */
						do {
							*q++ = *r++;
						} while (--c);
						break;
					} else if ((e & 64) == 0) {
						t += t->base;
						e = (t += ((uInt)b &
						    inflate_mask[e]))->exop;
					} else {
						z->msg =
						    "invalid distance code";
						UNGRAB;
						UPDATE;
						return (Z_DATA_ERROR);
					}
					/* CONSTCOND */
				} while (1);
				break;
			}
			if ((e & 64) == 0)
			{
				t += t->base;
				if ((e = (t += ((uInt)b &
				    inflate_mask[e]))->exop) == 0)
				{
					DUMPBITS(t->bits);
					Tracevv((stderr, t->base >= 0x20 &&
					    t->base < 0x7f ?
					    "inflate:         * literal '%c'\n"
					    :
					    "inflate:         * literal "
					    "0x%02x\n", t->base));
					*q++ = (Byte)t->base;
					m--;
					break;
				}
			} else if (e & 32) {
				Tracevv((stderr,
				    "inflate:         * end of block\n"));
				UNGRAB;
				UPDATE;
				return (Z_STREAM_END);
			} else {
				z->msg = "invalid literal/length code";
				UNGRAB;
				UPDATE;
				return (Z_DATA_ERROR);
			}
			/* CONSTCOND */
		} while (1);
	} while (m >= 258 && n >= 10);

	/* not enough input or output--restore pointers and return */
	UNGRAB;
	UPDATE;
	return (Z_OK);
}
/* --- inffast.c */

/* +++ zutil.c */
/*
 * zutil.c -- target dependent utility functions for the compression library
 * Copyright (C) 1995-1998 Jean-loup Gailly.
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */

#ifdef DEBUG_ZLIB
#include <stdio.h>
#endif

/* #include "zutil.h" */

#ifndef NO_DUMMY_DECL
struct internal_state	{int dummy; };	/* for buggy compilers */
#endif

#ifndef STDC
extern void exit OF((int));
#endif

static const char *z_errmsg[10] = {
"need dictionary",	/* Z_NEED_DICT		2 */
"stream end",		/* Z_STREAM_END		1 */
"",			/* Z_OK			0 */
"file error",		/* Z_ERRNO		(-1) */
"stream error",		/* Z_STREAM_ERROR	(-2) */
"data error",		/* Z_DATA_ERROR		(-3) */
"insufficient memory",	/* Z_MEM_ERROR		(-4) */
"buffer error",		/* Z_BUF_ERROR		(-5) */
"incompatible version",	/* Z_VERSION_ERROR	(-6) */
""};


const char *
zlibVersion()
{
	return (ZLIB_VERSION);
}

#ifdef DEBUG_ZLIB
void
z_error(m)
    char *m;
{
	fprintf(stderr, "%s\n", m);
	exit(1);
}
#endif

#ifndef HAVE_MEMCPY

void
zmemcpy(dest, source, len)
    Bytef* dest;
    const Bytef* source;
    uInt  len;
{
	if (len == 0)
		return;
	do {
		*dest++ = *source++;	/* ??? to be unrolled */
	} while (--len != 0);
}

int
zmemcmp(s1, s2, len)
const Bytef* s1;
const Bytef* s2;
uInt  len;
{
	uInt j;

	for (j = 0; j < len; j++) {
		if (s1[j] != s2[j])
			return (2*(s1[j] > s2[j])-1);
	}
	return (0);
}

void
zmemzero(dest, len)
    Bytef* dest;
    uInt  len;
{
	if (len == 0)
		return;
	do {
		*dest++ = 0;	/* ??? to be unrolled */
	} while (--len != 0);
}
#endif

#ifdef __TURBOC__
#if (defined(__BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
/*
 * Small and medium model in Turbo C are for now limited to near
 * allocation with reduced MAX_WBITS and MAX_MEM_LEVEL
 */
#define	MY_ZCALLOC

/*
 * Turbo C malloc() does not allow dynamic allocation of 64K bytes and
 * farmalloc(64K) returns a pointer with an offset of 8, so we must
 * fix the pointer. Warning: the pointer must be put back to its
 * original form in order to free it, use zcfree().
 */

#define	MAX_PTR 10
/* 10*64K = 640K */

local int next_ptr = 0;

typedef struct ptr_table_s {
	voidpf org_ptr;
	voidpf new_ptr;
} ptr_table;

local ptr_table table[MAX_PTR];
/*
 * This table is used to remember the original form of pointers to
 * large buffers (64K). Such pointers are normalized with a zero
 * offset.  Since MSDOS is not a preemptive multitasking OS, this
 * table is not protected from concurrent access. This hack doesn't
 * work anyway on a protected system like OS/2. Use Microsoft C
 * instead.
 */

voidpf
zcalloc(voidpf opaque, unsigned items, unsigned size)
{
	voidpf buf = opaque;	/* just to make some compilers happy */
	ulg bsize = (ulg)items*size;

	/*
	 * If we allocate less than 65520 bytes, we assume that
	 * farmalloc will return a usable pointer which doesn't have
	 * to be normalized.
	 */
	if (bsize < 65520L) {
		buf = farmalloc(bsize);
		if (*(ush *)&buf != 0)
			return (buf);
	} else {
		buf = farmalloc(bsize + 16L);
	}
	if (buf == NULL || next_ptr >= MAX_PTR)
		return (NULL);
	table[next_ptr].org_ptr = buf;

	/* Normalize the pointer to seg:0 */
	*((ush *)&buf+1) += ((ush)((uch *)buf-0) + 15) >> 4;
	*(ush *)&buf = 0;
	table[next_ptr++].new_ptr = buf;
	return (buf);
}

void
zcfree(voidpf opaque, voidpf ptr)
{
	int n;
	if (*(ush*)&ptr != 0) { /* object < 64K */
		farfree(ptr);
		return;
	}
	/* Find the original pointer */
	for (n = 0; n < next_ptr; n++) {
		if (ptr != table[n].new_ptr)
			continue;

		farfree(table[n].org_ptr);
		while (++n < next_ptr) {
			table[n-1] = table[n];
		}
		next_ptr--;
		return;
	}
	ptr = opaque;	/* just to make some compilers happy */
	Assert(0, "zcfree: ptr not found");
}
#endif
#endif /* __TURBOC__ */


#if defined(M_I86) && !defined(__32BIT__)
/* Microsoft C in 16-bit mode */

#define	MY_ZCALLOC

#if (!defined(_MSC_VER) || (_MSC_VER <= 600))
#define	_halloc  halloc
#define	_hfree   hfree
#endif

voidpf
zcalloc(voidpf opaque, unsigned items, unsigned size)
{
	if (opaque) opaque = 0;	/* to make compiler happy */
	return (_halloc((long)items, size));
}

void
zcfree(voidpf opaque, voidpf ptr)
{
	if (opaque) opaque = 0;	/* to make compiler happy */
	_hfree(ptr);
}

#endif /* MSC */


#ifndef MY_ZCALLOC /* Any system without a special alloc function */

#ifndef STDC
extern voidp  calloc OF((uInt items, uInt size));
extern void   free   OF((voidpf ptr));
#endif

voidpf
zcalloc(opaque, items, size)
    voidpf opaque;
    unsigned items;
    unsigned size;
{
	if (opaque) items += size - size;	/* make compiler happy */
	return ((voidpf)calloc(items, size));
}

/*ARGSUSED*/
void
zcfree(opaque, ptr)
    voidpf opaque;
    voidpf ptr;
{
	free(ptr);
}

#endif /* MY_ZCALLOC */
/* --- zutil.c */

/* +++ adler32.c */
/*
 * adler32.c -- compute the Adler-32 checksum of a data stream
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */

/* #include "zlib.h" */

#define	BASE 65521L /* largest prime smaller than 65536 */
#define	NMAX 5552
/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */

#define	DO1(buf, i)  {s1 += buf[i]; s2 += s1; }
#define	DO2(buf, i)  DO1(buf, i); DO1(buf, i+1);
#define	DO4(buf, i)  DO2(buf, i); DO2(buf, i+2);
#define	DO8(buf, i)  DO4(buf, i); DO4(buf, i+4);
#define	DO16(buf)   DO8(buf, 0); DO8(buf, 8);

/* ========================================================================= */
uLong
adler32(adler, buf, len)
    uLong adler;
    const Bytef *buf;
    uInt len;
{
	unsigned long s1 = adler & 0xffff;
	unsigned long s2 = (adler >> 16) & 0xffff;
	int k;

	if (buf == Z_NULL)
		return (1L);

	while (len > 0) {
		k = len < NMAX ? len : NMAX;
		len -= k;
		while (k >= 16) {
			DO16(buf);
			buf += 16;
			k -= 16;
		}
		if (k != 0) do {
			s1 += *buf++;
			s2 += s1;
		} while (--k);
		s1 %= BASE;
		s2 %= BASE;
	}
	return ((s2 << 16) | s1);
}
/* --- adler32.c */