source: rtems/c/src/libnetworking/net/zlib.c @ 0286b9f

4.104.114.84.95
Last change on this file since 0286b9f was 0286b9f, checked in by Joel Sherrill <joel.sherrill@…>, on 01/31/02 at 21:42:11

2001-01-31 Mike Siers <mikes@…>

  • Nice Update of PPPD support which eliminates the requiremetn that drivers be in the termios TASK_DRIVEN mode. Mike did significant testing and reports that it seems to be more stable and handle larger packets better. This patch replaces the termios tasks with more general pppd network driver tasks. The functions pppinput() and pppstart() get called from the interrupt service routine.
  • Makefile.am, configure.ac, net/Makefile.am, net/bpf.h, net/ethernet.h, net/if.c, net/if.h, net/if_arp.h, net/if_dl.h, net/if_ethersubr.c, net/if_llc.h, net/if_loop.c, net/if_ppp.h, net/if_pppvar.h, net/if_types.h, net/netisr.h, net/ppp-comp.h, net/ppp_defs.h, net/pppcompress.h, net/radix.c, net/radix.h, net/raw_cb.c, net/raw_cb.h, net/raw_usrreq.c, net/route.c, net/route.h, net/rtsock.c, pppd/Makefile.am, pppd/README, pppd/STATUS, pppd/auth.c, pppd/cbcp.c, pppd/ccp.c, pppd/ccp.h, pppd/chap.c, pppd/chap.h, pppd/chap_ms.c, pppd/chap_ms.h, pppd/chat.c, pppd/demand.c, pppd/fsm.c, pppd/fsm.h, pppd/ipcp.c, pppd/ipcp.h, pppd/ipxcp.c, pppd/ipxcp.h, pppd/lcp.c, pppd/lcp.h, pppd/magic.c, pppd/magic.h, pppd/options.c, pppd/patchlevel.h, pppd/pathnames.h, pppd/pppd.8, pppd/pppd.h, pppd/rtemsmain.c, pppd/rtemspppd.c, pppd/rtemspppd.h, pppd/sys-rtems.c, pppd/upap.c, pppd/upap.h, pppd/utils.c, pppd/example/README, pppd/example/netconfig.h, wrapup/Makefile.am: Modified.
  • net/bsd-comp.c, net/if_ppp.c, net/ppp-deflate.c, net/ppp.h, net/ppp_tty.c, net/pppcompress.c, net/zlib.c, net/zlib.h: New file.
  • modem/, modem/.cvsignore, modem/Makefile.am, modem/ppp.c, modem/ppp.h, modem/ppp_tty.c, modem/pppcompress.c: Subdirectory removed.
  • Property mode set to 100644
File size: 174.1 KB
Line 
1/*
2 * This file is derived from various .h and .c files from the zlib-1.0.4
3 * distribution by Jean-loup Gailly and Mark Adler, with some additions
4 * by Paul Mackerras to aid in implementing Deflate compression and
5 * decompression for PPP packets.  See zlib.h for conditions of
6 * distribution and use.
7 *
8 * Changes that have been made include:
9 * - added Z_PACKET_FLUSH (see zlib.h for details)
10 * - added inflateIncomp and deflateOutputPending
11 * - allow strm->next_out to be NULL, meaning discard the output
12 *
13 * $Id$
14 */
15
16/*
17 *  ==FILEVERSION 971210==
18 *
19 * This marker is used by the Linux installation script to determine
20 * whether an up-to-date version of this file is already installed.
21 */
22
23#define NO_DUMMY_DECL
24#define NO_ZCFUNCS
25#define MY_ZCALLOC
26
27#if defined(__FreeBSD__) && (defined(KERNEL) || defined(_KERNEL))
28#define inflate inflate_ppp     /* FreeBSD already has an inflate :-( */
29#endif
30
31
32/* +++ zutil.h */
33/* zutil.h -- internal interface and configuration of the compression library
34 * Copyright (C) 1995-1996 Jean-loup Gailly.
35 * For conditions of distribution and use, see copyright notice in zlib.h
36 */
37
38/* WARNING: this file should *not* be used by applications. It is
39   part of the implementation of the compression library and is
40   subject to change. Applications should only use zlib.h.
41 */
42
43/* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */
44
45#ifndef _Z_UTIL_H
46#define _Z_UTIL_H
47
48#include "zlib.h"
49
50#if defined(KERNEL) || defined(_KERNEL)
51/* Assume this is a *BSD or SVR4 kernel */
52#include <sys/types.h>
53#include <sys/time.h>
54#include <sys/systm.h>
55#undef u
56#  define HAVE_MEMCPY
57#  define memcpy(d, s, n)       bcopy((s), (d), (n))
58#  define memset(d, v, n)       bzero((d), (n))
59#  define memcmp                bcmp
60
61#else
62#if defined(__KERNEL__)
63/* Assume this is a Linux kernel */
64#include <linux/string.h>
65#define HAVE_MEMCPY
66
67#else /* not kernel */
68
69#if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS)
70#   include <stddef.h>
71#   include <errno.h>
72#else
73    extern int errno;
74#endif
75#ifdef STDC
76#  include <string.h>
77#  include <stdlib.h>
78#endif
79#endif /* __KERNEL__ */
80#endif /* _KERNEL || KERNEL */
81
82#ifndef local
83#  define local static
84#endif
85/* compile with -Dlocal if your debugger can't find static symbols */
86
87typedef unsigned char  uch;
88typedef uch FAR uchf;
89typedef unsigned short ush;
90typedef ush FAR ushf;
91typedef unsigned long  ulg;
92
93extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
94/* (size given to avoid silly warnings with Visual C++) */
95
96#define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
97
98#define ERR_RETURN(strm,err) \
99  return (strm->msg = (char*)ERR_MSG(err), (err))
100/* To be used only when the state is known to be valid */
101
102        /* common constants */
103
104#ifndef DEF_WBITS
105#  define DEF_WBITS MAX_WBITS
106#endif
107/* default windowBits for decompression. MAX_WBITS is for compression only */
108
109#if MAX_MEM_LEVEL >= 8
110#  define DEF_MEM_LEVEL 8
111#else
112#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
113#endif
114/* default memLevel */
115
116#define STORED_BLOCK 0
117#define STATIC_TREES 1
118#define DYN_TREES    2
119/* The three kinds of block type */
120
121#define MIN_MATCH  3
122#define MAX_MATCH  258
123/* The minimum and maximum match lengths */
124
125#define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
126
127        /* target dependencies */
128
129#ifdef MSDOS
130#  define OS_CODE  0x00
131#  ifdef __TURBOC__
132#    include <alloc.h>
133#  else /* MSC or DJGPP */
134#    include <malloc.h>
135#  endif
136#endif
137
138#ifdef OS2
139#  define OS_CODE  0x06
140#endif
141
142#ifdef WIN32 /* Window 95 & Windows NT */
143#  define OS_CODE  0x0b
144#endif
145
146#if defined(VAXC) || defined(VMS)
147#  define OS_CODE  0x02
148#  define FOPEN(name, mode) \
149     fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
150#endif
151
152#ifdef AMIGA
153#  define OS_CODE  0x01
154#endif
155
156#if defined(ATARI) || defined(atarist)
157#  define OS_CODE  0x05
158#endif
159
160#ifdef MACOS
161#  define OS_CODE  0x07
162#endif
163
164#ifdef __50SERIES /* Prime/PRIMOS */
165#  define OS_CODE  0x0F
166#endif
167
168#ifdef TOPS20
169#  define OS_CODE  0x0a
170#endif
171
172#if defined(_BEOS_) || defined(RISCOS)
173#  define fdopen(fd,mode) NULL /* No fdopen() */
174#endif
175
176        /* Common defaults */
177
178#ifndef OS_CODE
179#  define OS_CODE  0x03  /* assume Unix */
180#endif
181
182#ifndef FOPEN
183#  define FOPEN(name, mode) fopen((name), (mode))
184#endif
185
186         /* functions */
187
188#ifdef HAVE_STRERROR
189   extern char *strerror OF((int));
190#  define zstrerror(errnum) strerror(errnum)
191#else
192#  define zstrerror(errnum) ""
193#endif
194
195#if defined(pyr)
196#  define NO_MEMCPY
197#endif
198#if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
199 /* Use our own functions for small and medium model with MSC <= 5.0.
200  * You may have to use the same strategy for Borland C (untested).
201  */
202#  define NO_MEMCPY
203#endif
204#if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
205#  define HAVE_MEMCPY
206#endif
207#ifdef HAVE_MEMCPY
208#  ifdef SMALL_MEDIUM /* MSDOS small or medium model */
209#    define zmemcpy _fmemcpy
210#    define zmemcmp _fmemcmp
211#    define zmemzero(dest, len) _fmemset(dest, 0, len)
212#  else
213#    define zmemcpy memcpy
214#    define zmemcmp memcmp
215#    define zmemzero(dest, len) memset(dest, 0, len)
216#  endif
217#else
218   extern void zmemcpy  OF((Bytef* dest, Bytef* source, uInt len));
219   extern int  zmemcmp  OF((Bytef* s1,   Bytef* s2, uInt len));
220   extern void zmemzero OF((Bytef* dest, uInt len));
221#endif
222
223/* Diagnostic functions */
224#ifdef DEBUG_ZLIB
225#  include <stdio.h>
226#  ifndef verbose
227#    define verbose 0
228#  endif
229   extern void z_error    OF((char *m));
230#  define Assert(cond,msg) {if(!(cond)) z_error(msg);}
231#  define Trace(x) fprintf x
232#  define Tracev(x) {if (verbose) fprintf x ;}
233#  define Tracevv(x) {if (verbose>1) fprintf x ;}
234#  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
235#  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
236#else
237#  define Assert(cond,msg)
238#  define Trace(x)
239#  define Tracev(x)
240#  define Tracevv(x)
241#  define Tracec(c,x)
242#  define Tracecv(c,x)
243#endif
244
245
246typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));
247
248voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
249void   zcfree  OF((voidpf opaque, voidpf ptr));
250
251#define ZALLOC(strm, items, size) \
252           (*((strm)->zalloc))((strm)->opaque, (items), (size))
253#define ZFREE(strm, addr)  (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
254#define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
255
256#endif /* _Z_UTIL_H */
257/* --- zutil.h */
258
259/* +++ deflate.h */
260/* deflate.h -- internal compression state
261 * Copyright (C) 1995-1996 Jean-loup Gailly
262 * For conditions of distribution and use, see copyright notice in zlib.h
263 */
264
265/* WARNING: this file should *not* be used by applications. It is
266   part of the implementation of the compression library and is
267   subject to change. Applications should only use zlib.h.
268 */
269
270/* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */
271
272#ifndef _DEFLATE_H
273#define _DEFLATE_H
274
275/* #include "zutil.h" */
276
277/* ===========================================================================
278 * Internal compression state.
279 */
280
281#define LENGTH_CODES 29
282/* number of length codes, not counting the special END_BLOCK code */
283
284#define LITERALS  256
285/* number of literal bytes 0..255 */
286
287#define L_CODES (LITERALS+1+LENGTH_CODES)
288/* number of Literal or Length codes, including the END_BLOCK code */
289
290#define D_CODES   30
291/* number of distance codes */
292
293#define BL_CODES  19
294/* number of codes used to transfer the bit lengths */
295
296#define HEAP_SIZE (2*L_CODES+1)
297/* maximum heap size */
298
299#define MAX_BITS 15
300/* All codes must not exceed MAX_BITS bits */
301
302#define INIT_STATE    42
303#define BUSY_STATE   113
304#define FINISH_STATE 666
305/* Stream status */
306
307
308/* Data structure describing a single value and its code string. */
309typedef struct ct_data_s {
310    union {
311        ush  freq;       /* frequency count */
312        ush  code;       /* bit string */
313    } fc;
314    union {
315        ush  dad;        /* father node in Huffman tree */
316        ush  len;        /* length of bit string */
317    } dl;
318} FAR ct_data;
319
320#define Freq fc.freq
321#define Code fc.code
322#define Dad  dl.dad
323#define Len  dl.len
324
325typedef struct static_tree_desc_s  static_tree_desc;
326
327typedef struct tree_desc_s {
328    ct_data *dyn_tree;           /* the dynamic tree */
329    int     max_code;            /* largest code with non zero frequency */
330    static_tree_desc *stat_desc; /* the corresponding static tree */
331} FAR tree_desc;
332
333typedef ush Pos;
334typedef Pos FAR Posf;
335typedef unsigned IPos;
336
337/* A Pos is an index in the character window. We use short instead of int to
338 * save space in the various tables. IPos is used only for parameter passing.
339 */
340
341typedef struct deflate_state {
342    z_streamp strm;      /* pointer back to this zlib stream */
343    int   status;        /* as the name implies */
344    Bytef *pending_buf;  /* output still pending */
345    ulg   pending_buf_size; /* size of pending_buf */
346    Bytef *pending_out;  /* next pending byte to output to the stream */
347    int   pending;       /* nb of bytes in the pending buffer */
348    int   noheader;      /* suppress zlib header and adler32 */
349    Byte  data_type;     /* UNKNOWN, BINARY or ASCII */
350    Byte  method;        /* STORED (for zip only) or DEFLATED */
351    int   last_flush;    /* value of flush param for previous deflate call */
352
353                /* used by deflate.c: */
354
355    uInt  w_size;        /* LZ77 window size (32K by default) */
356    uInt  w_bits;        /* log2(w_size)  (8..16) */
357    uInt  w_mask;        /* w_size - 1 */
358
359    Bytef *window;
360    /* Sliding window. Input bytes are read into the second half of the window,
361     * and move to the first half later to keep a dictionary of at least wSize
362     * bytes. With this organization, matches are limited to a distance of
363     * wSize-MAX_MATCH bytes, but this ensures that IO is always
364     * performed with a length multiple of the block size. Also, it limits
365     * the window size to 64K, which is quite useful on MSDOS.
366     * To do: use the user input buffer as sliding window.
367     */
368
369    ulg window_size;
370    /* Actual size of window: 2*wSize, except when the user input buffer
371     * is directly used as sliding window.
372     */
373
374    Posf *prev;
375    /* Link to older string with same hash index. To limit the size of this
376     * array to 64K, this link is maintained only for the last 32K strings.
377     * An index in this array is thus a window index modulo 32K.
378     */
379
380    Posf *head; /* Heads of the hash chains or NIL. */
381
382    uInt  ins_h;          /* hash index of string to be inserted */
383    uInt  hash_size;      /* number of elements in hash table */
384    uInt  hash_bits;      /* log2(hash_size) */
385    uInt  hash_mask;      /* hash_size-1 */
386
387    uInt  hash_shift;
388    /* Number of bits by which ins_h must be shifted at each input
389     * step. It must be such that after MIN_MATCH steps, the oldest
390     * byte no longer takes part in the hash key, that is:
391     *   hash_shift * MIN_MATCH >= hash_bits
392     */
393
394    long block_start;
395    /* Window position at the beginning of the current output block. Gets
396     * negative when the window is moved backwards.
397     */
398
399    uInt match_length;           /* length of best match */
400    IPos prev_match;             /* previous match */
401    int match_available;         /* set if previous match exists */
402    uInt strstart;               /* start of string to insert */
403    uInt match_start;            /* start of matching string */
404    uInt lookahead;              /* number of valid bytes ahead in window */
405
406    uInt prev_length;
407    /* Length of the best match at previous step. Matches not greater than this
408     * are discarded. This is used in the lazy match evaluation.
409     */
410
411    uInt max_chain_length;
412    /* To speed up deflation, hash chains are never searched beyond this
413     * length.  A higher limit improves compression ratio but degrades the
414     * speed.
415     */
416
417    uInt max_lazy_match;
418    /* Attempt to find a better match only when the current match is strictly
419     * smaller than this value. This mechanism is used only for compression
420     * levels >= 4.
421     */
422#   define max_insert_length  max_lazy_match
423    /* Insert new strings in the hash table only if the match length is not
424     * greater than this length. This saves time but degrades compression.
425     * max_insert_length is used only for compression levels <= 3.
426     */
427
428    int level;    /* compression level (1..9) */
429    int strategy; /* favor or force Huffman coding*/
430
431    uInt good_match;
432    /* Use a faster search when the previous match is longer than this */
433
434    int nice_match; /* Stop searching when current match exceeds this */
435
436                /* used by trees.c: */
437    /* Didn't use ct_data typedef below to supress compiler warning */
438    struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
439    struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
440    struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
441
442    struct tree_desc_s l_desc;               /* desc. for literal tree */
443    struct tree_desc_s d_desc;               /* desc. for distance tree */
444    struct tree_desc_s bl_desc;              /* desc. for bit length tree */
445
446    ush bl_count[MAX_BITS+1];
447    /* number of codes at each bit length for an optimal tree */
448
449    int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
450    int heap_len;               /* number of elements in the heap */
451    int heap_max;               /* element of largest frequency */
452    /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
453     * The same heap array is used to build all trees.
454     */
455
456    uch depth[2*L_CODES+1];
457    /* Depth of each subtree used as tie breaker for trees of equal frequency
458     */
459
460    uchf *l_buf;          /* buffer for literals or lengths */
461
462    uInt  lit_bufsize;
463    /* Size of match buffer for literals/lengths.  There are 4 reasons for
464     * limiting lit_bufsize to 64K:
465     *   - frequencies can be kept in 16 bit counters
466     *   - if compression is not successful for the first block, all input
467     *     data is still in the window so we can still emit a stored block even
468     *     when input comes from standard input.  (This can also be done for
469     *     all blocks if lit_bufsize is not greater than 32K.)
470     *   - if compression is not successful for a file smaller than 64K, we can
471     *     even emit a stored file instead of a stored block (saving 5 bytes).
472     *     This is applicable only for zip (not gzip or zlib).
473     *   - creating new Huffman trees less frequently may not provide fast
474     *     adaptation to changes in the input data statistics. (Take for
475     *     example a binary file with poorly compressible code followed by
476     *     a highly compressible string table.) Smaller buffer sizes give
477     *     fast adaptation but have of course the overhead of transmitting
478     *     trees more frequently.
479     *   - I can't count above 4
480     */
481
482    uInt last_lit;      /* running index in l_buf */
483
484    ushf *d_buf;
485    /* Buffer for distances. To simplify the code, d_buf and l_buf have
486     * the same number of elements. To use different lengths, an extra flag
487     * array would be necessary.
488     */
489
490    ulg opt_len;        /* bit length of current block with optimal trees */
491    ulg static_len;     /* bit length of current block with static trees */
492    ulg compressed_len; /* total bit length of compressed file */
493    uInt matches;       /* number of string matches in current block */
494    int last_eob_len;   /* bit length of EOB code for last block */
495
496#ifdef DEBUG_ZLIB
497    ulg bits_sent;      /* bit length of the compressed data */
498#endif
499
500    ush bi_buf;
501    /* Output buffer. bits are inserted starting at the bottom (least
502     * significant bits).
503     */
504    int bi_valid;
505    /* Number of valid bits in bi_buf.  All bits above the last valid bit
506     * are always zero.
507     */
508
509} FAR deflate_state;
510
511/* Output a byte on the stream.
512 * IN assertion: there is enough room in pending_buf.
513 */
514#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
515
516
517#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
518/* Minimum amount of lookahead, except at the end of the input file.
519 * See deflate.c for comments about the MIN_MATCH+1.
520 */
521
522#define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
523/* In order to simplify the code, particularly on 16 bit machines, match
524 * distances are limited to MAX_DIST instead of WSIZE.
525 */
526
527        /* in trees.c */
528void _tr_init         OF((deflate_state *s));
529int  _tr_tally        OF((deflate_state *s, unsigned dist, unsigned lc));
530ulg  _tr_flush_block  OF((deflate_state *s, charf *buf, ulg stored_len,
531                          int eof));
532void _tr_align        OF((deflate_state *s));
533void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
534                          int eof));
535void _tr_stored_type_only OF((deflate_state *));
536
537#endif
538/* --- deflate.h */
539
540/* +++ deflate.c */
541/* deflate.c -- compress data using the deflation algorithm
542 * Copyright (C) 1995-1996 Jean-loup Gailly.
543 * For conditions of distribution and use, see copyright notice in zlib.h
544 */
545
546/*
547 *  ALGORITHM
548 *
549 *      The "deflation" process depends on being able to identify portions
550 *      of the input text which are identical to earlier input (within a
551 *      sliding window trailing behind the input currently being processed).
552 *
553 *      The most straightforward technique turns out to be the fastest for
554 *      most input files: try all possible matches and select the longest.
555 *      The key feature of this algorithm is that insertions into the string
556 *      dictionary are very simple and thus fast, and deletions are avoided
557 *      completely. Insertions are performed at each input character, whereas
558 *      string matches are performed only when the previous match ends. So it
559 *      is preferable to spend more time in matches to allow very fast string
560 *      insertions and avoid deletions. The matching algorithm for small
561 *      strings is inspired from that of Rabin & Karp. A brute force approach
562 *      is used to find longer strings when a small match has been found.
563 *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
564 *      (by Leonid Broukhis).
565 *         A previous version of this file used a more sophisticated algorithm
566 *      (by Fiala and Greene) which is guaranteed to run in linear amortized
567 *      time, but has a larger average cost, uses more memory and is patented.
568 *      However the F&G algorithm may be faster for some highly redundant
569 *      files if the parameter max_chain_length (described below) is too large.
570 *
571 *  ACKNOWLEDGEMENTS
572 *
573 *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
574 *      I found it in 'freeze' written by Leonid Broukhis.
575 *      Thanks to many people for bug reports and testing.
576 *
577 *  REFERENCES
578 *
579 *      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
580 *      Available in ftp://ds.internic.net/rfc/rfc1951.txt
581 *
582 *      A description of the Rabin and Karp algorithm is given in the book
583 *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
584 *
585 *      Fiala,E.R., and Greene,D.H.
586 *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
587 *
588 */
589
590/* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */
591
592/* #include "deflate.h" */
593
594char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly ";
595/*
596  If you use the zlib library in a product, an acknowledgment is welcome
597  in the documentation of your product. If for some reason you cannot
598  include such an acknowledgment, I would appreciate that you keep this
599  copyright string in the executable of your product.
600 */
601
602/* ===========================================================================
603 *  Function prototypes.
604 */
605typedef enum {
606    need_more,      /* block not completed, need more input or more output */
607    block_done,     /* block flush performed */
608    finish_started, /* finish started, need only more output at next deflate */
609    finish_done     /* finish done, accept no more input or output */
610} block_state;
611
612typedef block_state (*compress_func) OF((deflate_state *s, int flush));
613/* Compression function. Returns the block state after the call. */
614
615local void fill_window    OF((deflate_state *s));
616local block_state deflate_stored OF((deflate_state *s, int flush));
617local block_state deflate_fast   OF((deflate_state *s, int flush));
618local block_state deflate_slow   OF((deflate_state *s, int flush));
619local void lm_init        OF((deflate_state *s));
620local void putShortMSB    OF((deflate_state *s, uInt b));
621local void flush_pending  OF((z_streamp strm));
622local int read_buf        OF((z_streamp strm, charf *buf, unsigned size));
623#ifdef ASMV
624      void match_init OF((void)); /* asm code initialization */
625      uInt longest_match  OF((deflate_state *s, IPos cur_match));
626#else
627local uInt longest_match  OF((deflate_state *s, IPos cur_match));
628#endif
629
630#ifdef DEBUG_ZLIB
631local  void check_match OF((deflate_state *s, IPos start, IPos match,
632                            int length));
633#endif
634
635/* ===========================================================================
636 * Local data
637 */
638
639#define NIL 0
640/* Tail of hash chains */
641
642#ifndef TOO_FAR
643#  define TOO_FAR 4096
644#endif
645/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
646
647#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
648/* Minimum amount of lookahead, except at the end of the input file.
649 * See deflate.c for comments about the MIN_MATCH+1.
650 */
651
652/* Values for max_lazy_match, good_match and max_chain_length, depending on
653 * the desired pack level (0..9). The values given below have been tuned to
654 * exclude worst case performance for pathological files. Better values may be
655 * found for specific files.
656 */
657typedef struct config_s {
658   ush good_length; /* reduce lazy search above this match length */
659   ush max_lazy;    /* do not perform lazy search above this match length */
660   ush nice_length; /* quit search above this match length */
661   ush max_chain;
662   compress_func func;
663} config;
664
665local config configuration_table[10] = {
666/*      good lazy nice chain */
667/* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
668/* 1 */ {4,    4,  8,    4, deflate_fast}, /* maximum speed, no lazy matches */
669/* 2 */ {4,    5, 16,    8, deflate_fast},
670/* 3 */ {4,    6, 32,   32, deflate_fast},
671
672/* 4 */ {4,    4, 16,   16, deflate_slow},  /* lazy matches */
673/* 5 */ {8,   16, 32,   32, deflate_slow},
674/* 6 */ {8,   16, 128, 128, deflate_slow},
675/* 7 */ {8,   32, 128, 256, deflate_slow},
676/* 8 */ {32, 128, 258, 1024, deflate_slow},
677/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
678
679/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
680 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
681 * meaning.
682 */
683
684#define EQUAL 0
685/* result of memcmp for equal strings */
686
687#ifndef NO_DUMMY_DECL
688struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
689#endif
690
691/* ===========================================================================
692 * Update a hash value with the given input byte
693 * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
694 *    input characters, so that a running hash key can be computed from the
695 *    previous key instead of complete recalculation each time.
696 */
697#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
698
699
700/* ===========================================================================
701 * Insert string str in the dictionary and set match_head to the previous head
702 * of the hash chain (the most recent string with same hash key). Return
703 * the previous length of the hash chain.
704 * IN  assertion: all calls to to INSERT_STRING are made with consecutive
705 *    input characters and the first MIN_MATCH bytes of str are valid
706 *    (except for the last MIN_MATCH-1 bytes of the input file).
707 */
708#define INSERT_STRING(s, str, match_head) \
709   (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
710    s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
711    s->head[s->ins_h] = (Pos)(str))
712
713/* ===========================================================================
714 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
715 * prev[] will be initialized on the fly.
716 */
717#define CLEAR_HASH(s) \
718    s->head[s->hash_size-1] = NIL; \
719    zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
720
721/* ========================================================================= */
722int deflateInit_(strm, level, version, stream_size)
723    z_streamp strm;
724    int level;
725    const char *version;
726    int stream_size;
727{
728    return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
729                         Z_DEFAULT_STRATEGY, version, stream_size);
730    /* To do: ignore strm->next_in if we use it as window */
731}
732
733/* ========================================================================= */
734int deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
735                  version, stream_size)
736    z_streamp strm;
737    int  level;
738    int  method;
739    int  windowBits;
740    int  memLevel;
741    int  strategy;
742    const char *version;
743    int stream_size;
744{
745    deflate_state *s;
746    int noheader = 0;
747    static char* my_version = ZLIB_VERSION;
748
749    ushf *overlay;
750    /* We overlay pending_buf and d_buf+l_buf. This works since the average
751     * output size for (length,distance) codes is <= 24 bits.
752     */
753
754    if (version == Z_NULL || version[0] != my_version[0] ||
755        stream_size != sizeof(z_stream)) {
756        return Z_VERSION_ERROR;
757    }
758    if (strm == Z_NULL) return Z_STREAM_ERROR;
759
760    strm->msg = Z_NULL;
761#ifndef NO_ZCFUNCS
762    if (strm->zalloc == Z_NULL) {
763        strm->zalloc = zcalloc;
764        strm->opaque = (voidpf)0;
765    }
766    if (strm->zfree == Z_NULL) strm->zfree = zcfree;
767#endif
768
769    if (level == Z_DEFAULT_COMPRESSION) level = 6;
770
771    if (windowBits < 0) { /* undocumented feature: suppress zlib header */
772        noheader = 1;
773        windowBits = -windowBits;
774    }
775    if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
776        windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
777        strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
778        return Z_STREAM_ERROR;
779    }
780    s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
781    if (s == Z_NULL) return Z_MEM_ERROR;
782    strm->state = (struct internal_state FAR *)s;
783    s->strm = strm;
784
785    s->noheader = noheader;
786    s->w_bits = windowBits;
787    s->w_size = 1 << s->w_bits;
788    s->w_mask = s->w_size - 1;
789
790    s->hash_bits = memLevel + 7;
791    s->hash_size = 1 << s->hash_bits;
792    s->hash_mask = s->hash_size - 1;
793    s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
794
795    s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
796    s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
797    s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
798
799    s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
800
801    overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
802    s->pending_buf = (uchf *) overlay;
803    s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
804
805    if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
806        s->pending_buf == Z_NULL) {
807        strm->msg = (char*)ERR_MSG(Z_MEM_ERROR);
808        deflateEnd (strm);
809        return Z_MEM_ERROR;
810    }
811    s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
812    s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
813
814    s->level = level;
815    s->strategy = strategy;
816    s->method = (Byte)method;
817
818    return deflateReset(strm);
819}
820
821/* ========================================================================= */
822int deflateSetDictionary (strm, dictionary, dictLength)
823    z_streamp strm;
824    const Bytef *dictionary;
825    uInt  dictLength;
826{
827    deflate_state *s;
828    uInt length = dictLength;
829    uInt n;
830    IPos hash_head = 0;
831
832    if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
833        return Z_STREAM_ERROR;
834
835    s = (deflate_state *) strm->state;
836    if (s->status != INIT_STATE) return Z_STREAM_ERROR;
837
838    strm->adler = adler32(strm->adler, dictionary, dictLength);
839
840    if (length < MIN_MATCH) return Z_OK;
841    if (length > MAX_DIST(s)) {
842        length = MAX_DIST(s);
843#ifndef USE_DICT_HEAD
844        dictionary += dictLength - length; /* use the tail of the dictionary */
845#endif
846    }
847    zmemcpy((charf *)s->window, dictionary, length);
848    s->strstart = length;
849    s->block_start = (long)length;
850
851    /* Insert all strings in the hash table (except for the last two bytes).
852     * s->lookahead stays null, so s->ins_h will be recomputed at the next
853     * call of fill_window.
854     */
855    s->ins_h = s->window[0];
856    UPDATE_HASH(s, s->ins_h, s->window[1]);
857    for (n = 0; n <= length - MIN_MATCH; n++) {
858        INSERT_STRING(s, n, hash_head);
859    }
860    if (hash_head) hash_head = 0;  /* to make compiler happy */
861    return Z_OK;
862}
863
864/* ========================================================================= */
865int deflateReset (strm)
866    z_streamp strm;
867{
868    deflate_state *s;
869   
870    if (strm == Z_NULL || strm->state == Z_NULL ||
871        strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
872
873    strm->total_in = strm->total_out = 0;
874    strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
875    strm->data_type = Z_UNKNOWN;
876
877    s = (deflate_state *)strm->state;
878    s->pending = 0;
879    s->pending_out = s->pending_buf;
880
881    if (s->noheader < 0) {
882        s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
883    }
884    s->status = s->noheader ? BUSY_STATE : INIT_STATE;
885    strm->adler = 1;
886    s->last_flush = Z_NO_FLUSH;
887
888    _tr_init(s);
889    lm_init(s);
890
891    return Z_OK;
892}
893
894/* ========================================================================= */
895int deflateParams(strm, level, strategy)
896    z_streamp strm;
897    int level;
898    int strategy;
899{
900    deflate_state *s;
901    compress_func func;
902    int err = Z_OK;
903
904    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
905    s = (deflate_state *) strm->state;
906
907    if (level == Z_DEFAULT_COMPRESSION) {
908        level = 6;
909    }
910    if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
911        return Z_STREAM_ERROR;
912    }
913    func = configuration_table[s->level].func;
914
915    if (func != configuration_table[level].func && strm->total_in != 0) {
916        /* Flush the last buffer: */
917        err = deflate(strm, Z_PARTIAL_FLUSH);
918    }
919    if (s->level != level) {
920        s->level = level;
921        s->max_lazy_match   = configuration_table[level].max_lazy;
922        s->good_match       = configuration_table[level].good_length;
923        s->nice_match       = configuration_table[level].nice_length;
924        s->max_chain_length = configuration_table[level].max_chain;
925    }
926    s->strategy = strategy;
927    return err;
928}
929
930/* =========================================================================
931 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
932 * IN assertion: the stream state is correct and there is enough room in
933 * pending_buf.
934 */
935local void putShortMSB (s, b)
936    deflate_state *s;
937    uInt b;
938{
939    put_byte(s, (Byte)(b >> 8));
940    put_byte(s, (Byte)(b & 0xff));
941}   
942
943/* =========================================================================
944 * Flush as much pending output as possible. All deflate() output goes
945 * through this function so some applications may wish to modify it
946 * to avoid allocating a large strm->next_out buffer and copying into it.
947 * (See also read_buf()).
948 */
949local void flush_pending(strm)
950    z_streamp strm;
951{
952    deflate_state *s = (deflate_state *) strm->state;
953    unsigned len = s->pending;
954
955    if (len > strm->avail_out) len = strm->avail_out;
956    if (len == 0) return;
957
958    if (strm->next_out != Z_NULL) {
959        zmemcpy(strm->next_out, s->pending_out, len);
960        strm->next_out += len;
961    }
962    s->pending_out += len;
963    strm->total_out += len;
964    strm->avail_out  -= len;
965    s->pending -= len;
966    if (s->pending == 0) {
967        s->pending_out = s->pending_buf;
968    }
969}
970
971/* ========================================================================= */
972int deflate (strm, flush)
973    z_streamp strm;
974    int flush;
975{
976    int old_flush; /* value of flush param for previous deflate call */
977    deflate_state *s;
978
979    if (strm == Z_NULL || strm->state == Z_NULL ||
980        flush > Z_FINISH || flush < 0) {
981        return Z_STREAM_ERROR;
982    }
983    s = (deflate_state *) strm->state;
984
985    if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
986        (s->status == FINISH_STATE && flush != Z_FINISH)) {
987        ERR_RETURN(strm, Z_STREAM_ERROR);
988    }
989    if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
990
991    s->strm = strm; /* just in case */
992    old_flush = s->last_flush;
993    s->last_flush = flush;
994
995    /* Write the zlib header */
996    if (s->status == INIT_STATE) {
997
998        uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
999        uInt level_flags = (s->level-1) >> 1;
1000
1001        if (level_flags > 3) level_flags = 3;
1002        header |= (level_flags << 6);
1003        if (s->strstart != 0) header |= PRESET_DICT;
1004        header += 31 - (header % 31);
1005
1006        s->status = BUSY_STATE;
1007        putShortMSB(s, header);
1008
1009        /* Save the adler32 of the preset dictionary: */
1010        if (s->strstart != 0) {
1011            putShortMSB(s, (uInt)(strm->adler >> 16));
1012            putShortMSB(s, (uInt)(strm->adler & 0xffff));
1013        }
1014        strm->adler = 1L;
1015    }
1016
1017    /* Flush as much pending output as possible */
1018    if (s->pending != 0) {
1019        flush_pending(strm);
1020        if (strm->avail_out == 0) {
1021            /* Since avail_out is 0, deflate will be called again with
1022             * more output space, but possibly with both pending and
1023             * avail_in equal to zero. There won't be anything to do,
1024             * but this is not an error situation so make sure we
1025             * return OK instead of BUF_ERROR at next call of deflate:
1026             */
1027            s->last_flush = -1;
1028            return Z_OK;
1029        }
1030
1031    /* Make sure there is something to do and avoid duplicate consecutive
1032     * flushes. For repeated and useless calls with Z_FINISH, we keep
1033     * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1034     */
1035    } else if (strm->avail_in == 0 && flush <= old_flush &&
1036               flush != Z_FINISH) {
1037        ERR_RETURN(strm, Z_BUF_ERROR);
1038    }
1039
1040    /* User must not provide more input after the first FINISH: */
1041    if (s->status == FINISH_STATE && strm->avail_in != 0) {
1042        ERR_RETURN(strm, Z_BUF_ERROR);
1043    }
1044
1045    /* Start a new block or continue the current one.
1046     */
1047    if (strm->avail_in != 0 || s->lookahead != 0 ||
1048        (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1049        block_state bstate;
1050
1051        bstate = (*(configuration_table[s->level].func))(s, flush);
1052
1053        if (bstate == finish_started || bstate == finish_done) {
1054            s->status = FINISH_STATE;
1055        }
1056        if (bstate == need_more || bstate == finish_started) {
1057            if (strm->avail_out == 0) {
1058                s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1059            }
1060            return Z_OK;
1061            /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1062             * of deflate should use the same flush parameter to make sure
1063             * that the flush is complete. So we don't have to output an
1064             * empty block here, this will be done at next call. This also
1065             * ensures that for a very small output buffer, we emit at most
1066             * one empty block.
1067             */
1068        }
1069        if (bstate == block_done) {
1070            if (flush == Z_PARTIAL_FLUSH) {
1071                _tr_align(s);
1072            } else if (flush == Z_PACKET_FLUSH) {
1073                /* Output just the 3-bit `stored' block type value,
1074                   but not a zero length. */
1075                _tr_stored_type_only(s);
1076            } else { /* FULL_FLUSH or SYNC_FLUSH */
1077                _tr_stored_block(s, (char*)0, 0L, 0);
1078                /* For a full flush, this empty block will be recognized
1079                 * as a special marker by inflate_sync().
1080                 */
1081                if (flush == Z_FULL_FLUSH) {
1082                    CLEAR_HASH(s);             /* forget history */
1083                }
1084            }
1085            flush_pending(strm);
1086            if (strm->avail_out == 0) {
1087              s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1088              return Z_OK;
1089            }
1090        }
1091    }
1092    Assert(strm->avail_out > 0, "bug2");
1093
1094    if (flush != Z_FINISH) return Z_OK;
1095    if (s->noheader) return Z_STREAM_END;
1096
1097    /* Write the zlib trailer (adler32) */
1098    putShortMSB(s, (uInt)(strm->adler >> 16));
1099    putShortMSB(s, (uInt)(strm->adler & 0xffff));
1100    flush_pending(strm);
1101    /* If avail_out is zero, the application will call deflate again
1102     * to flush the rest.
1103     */
1104    s->noheader = -1; /* write the trailer only once! */
1105    return s->pending != 0 ? Z_OK : Z_STREAM_END;
1106}
1107
1108/* ========================================================================= */
1109int deflateEnd (strm)
1110    z_streamp strm;
1111{
1112    int status;
1113    deflate_state *s;
1114
1115    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1116    s = (deflate_state *) strm->state;
1117
1118    status = s->status;
1119    if (status != INIT_STATE && status != BUSY_STATE &&
1120        status != FINISH_STATE) {
1121      return Z_STREAM_ERROR;
1122    }
1123
1124    /* Deallocate in reverse order of allocations: */
1125    TRY_FREE(strm, s->pending_buf);
1126    TRY_FREE(strm, s->head);
1127    TRY_FREE(strm, s->prev);
1128    TRY_FREE(strm, s->window);
1129
1130    ZFREE(strm, s);
1131    strm->state = Z_NULL;
1132
1133    return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1134}
1135
1136/* =========================================================================
1137 * Copy the source state to the destination state.
1138 */
1139int deflateCopy (dest, source)
1140    z_streamp dest;
1141    z_streamp source;
1142{
1143    deflate_state *ds;
1144    deflate_state *ss;
1145    ushf *overlay;
1146
1147    if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
1148        return Z_STREAM_ERROR;
1149    ss = (deflate_state *) source->state;
1150
1151    zmemcpy(dest, source, sizeof(*dest));
1152
1153    ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1154    if (ds == Z_NULL) return Z_MEM_ERROR;
1155    dest->state = (struct internal_state FAR *) ds;
1156    zmemcpy(ds, ss, sizeof(*ds));
1157    ds->strm = dest;
1158
1159    ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1160    ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
1161    ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
1162    overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1163    ds->pending_buf = (uchf *) overlay;
1164
1165    if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1166        ds->pending_buf == Z_NULL) {
1167        deflateEnd (dest);
1168        return Z_MEM_ERROR;
1169    }
1170    /* ??? following zmemcpy doesn't work for 16-bit MSDOS */
1171    zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1172    zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1173    zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1174    zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1175
1176    ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1177    ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1178    ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1179
1180    ds->l_desc.dyn_tree = ds->dyn_ltree;
1181    ds->d_desc.dyn_tree = ds->dyn_dtree;
1182    ds->bl_desc.dyn_tree = ds->bl_tree;
1183
1184    return Z_OK;
1185}
1186
1187/* ===========================================================================
1188 * Return the number of bytes of output which are immediately available
1189 * for output from the decompressor.
1190 */
1191int deflateOutputPending (strm)
1192    z_streamp strm;
1193{
1194    if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1195   
1196    return ((deflate_state *)(strm->state))->pending;
1197}
1198
1199/* ===========================================================================
1200 * Read a new buffer from the current input stream, update the adler32
1201 * and total number of bytes read.  All deflate() input goes through
1202 * this function so some applications may wish to modify it to avoid
1203 * allocating a large strm->next_in buffer and copying from it.
1204 * (See also flush_pending()).
1205 */
1206local int read_buf(strm, buf, size)
1207    z_streamp strm;
1208    charf *buf;
1209    unsigned size;
1210{
1211    unsigned len = strm->avail_in;
1212
1213    if (len > size) len = size;
1214    if (len == 0) return 0;
1215
1216    strm->avail_in  -= len;
1217
1218    if (!((deflate_state *)(strm->state))->noheader) {
1219        strm->adler = adler32(strm->adler, strm->next_in, len);
1220    }
1221    zmemcpy(buf, strm->next_in, len);
1222    strm->next_in  += len;
1223    strm->total_in += len;
1224
1225    return (int)len;
1226}
1227
1228/* ===========================================================================
1229 * Initialize the "longest match" routines for a new zlib stream
1230 */
1231local void lm_init (s)
1232    deflate_state *s;
1233{
1234    s->window_size = (ulg)2L*s->w_size;
1235
1236    CLEAR_HASH(s);
1237
1238    /* Set the default configuration parameters:
1239     */
1240    s->max_lazy_match   = configuration_table[s->level].max_lazy;
1241    s->good_match       = configuration_table[s->level].good_length;
1242    s->nice_match       = configuration_table[s->level].nice_length;
1243    s->max_chain_length = configuration_table[s->level].max_chain;
1244
1245    s->strstart = 0;
1246    s->block_start = 0L;
1247    s->lookahead = 0;
1248    s->match_length = s->prev_length = MIN_MATCH-1;
1249    s->match_available = 0;
1250    s->ins_h = 0;
1251#ifdef ASMV
1252    match_init(); /* initialize the asm code */
1253#endif
1254}
1255
1256/* ===========================================================================
1257 * Set match_start to the longest match starting at the given string and
1258 * return its length. Matches shorter or equal to prev_length are discarded,
1259 * in which case the result is equal to prev_length and match_start is
1260 * garbage.
1261 * IN assertions: cur_match is the head of the hash chain for the current
1262 *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1263 * OUT assertion: the match length is not greater than s->lookahead.
1264 */
1265#ifndef ASMV
1266/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1267 * match.S. The code will be functionally equivalent.
1268 */
1269local uInt longest_match(s, cur_match)
1270    deflate_state *s;
1271    IPos cur_match;                             /* current match */
1272{
1273    unsigned chain_length = s->max_chain_length;/* max hash chain length */
1274    register Bytef *scan = s->window + s->strstart; /* current string */
1275    register Bytef *match;                       /* matched string */
1276    register int len;                           /* length of current match */
1277    int best_len = s->prev_length;              /* best match length so far */
1278    int nice_match = s->nice_match;             /* stop if match long enough */
1279    IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1280        s->strstart - (IPos)MAX_DIST(s) : NIL;
1281    /* Stop when cur_match becomes <= limit. To simplify the code,
1282     * we prevent matches with the string of window index 0.
1283     */
1284    Posf *prev = s->prev;
1285    uInt wmask = s->w_mask;
1286
1287#ifdef UNALIGNED_OK
1288    /* Compare two bytes at a time. Note: this is not always beneficial.
1289     * Try with and without -DUNALIGNED_OK to check.
1290     */
1291    register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1292    register ush scan_start = *(ushf*)scan;
1293    register ush scan_end   = *(ushf*)(scan+best_len-1);
1294#else
1295    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1296    register Byte scan_end1  = scan[best_len-1];
1297    register Byte scan_end   = scan[best_len];
1298#endif
1299
1300    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1301     * It is easy to get rid of this optimization if necessary.
1302     */
1303    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1304
1305    /* Do not waste too much time if we already have a good match: */
1306    if (s->prev_length >= s->good_match) {
1307        chain_length >>= 2;
1308    }
1309    /* Do not look for matches beyond the end of the input. This is necessary
1310     * to make deflate deterministic.
1311     */
1312    if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1313
1314    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1315
1316    do {
1317        Assert(cur_match < s->strstart, "no future");
1318        match = s->window + cur_match;
1319
1320        /* Skip to next match if the match length cannot increase
1321         * or if the match length is less than 2:
1322         */
1323#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1324        /* This code assumes sizeof(unsigned short) == 2. Do not use
1325         * UNALIGNED_OK if your compiler uses a different size.
1326         */
1327        if (*(ushf*)(match+best_len-1) != scan_end ||
1328            *(ushf*)match != scan_start) continue;
1329
1330        /* It is not necessary to compare scan[2] and match[2] since they are
1331         * always equal when the other bytes match, given that the hash keys
1332         * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1333         * strstart+3, +5, ... up to strstart+257. We check for insufficient
1334         * lookahead only every 4th comparison; the 128th check will be made
1335         * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1336         * necessary to put more guard bytes at the end of the window, or
1337         * to check more often for insufficient lookahead.
1338         */
1339        Assert(scan[2] == match[2], "scan[2]?");
1340        scan++, match++;
1341        do {
1342        } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1343                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1344                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1345                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1346                 scan < strend);
1347        /* The funny "do {}" generates better code on most compilers */
1348
1349        /* Here, scan <= window+strstart+257 */
1350        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1351        if (*scan == *match) scan++;
1352
1353        len = (MAX_MATCH - 1) - (int)(strend-scan);
1354        scan = strend - (MAX_MATCH-1);
1355
1356#else /* UNALIGNED_OK */
1357
1358        if (match[best_len]   != scan_end  ||
1359            match[best_len-1] != scan_end1 ||
1360            *match            != *scan     ||
1361            *++match          != scan[1])      continue;
1362
1363        /* The check at best_len-1 can be removed because it will be made
1364         * again later. (This heuristic is not always a win.)
1365         * It is not necessary to compare scan[2] and match[2] since they
1366         * are always equal when the other bytes match, given that
1367         * the hash keys are equal and that HASH_BITS >= 8.
1368         */
1369        scan += 2, match++;
1370        Assert(*scan == *match, "match[2]?");
1371
1372        /* We check for insufficient lookahead only every 8th comparison;
1373         * the 256th check will be made at strstart+258.
1374         */
1375        do {
1376        } while (*++scan == *++match && *++scan == *++match &&
1377                 *++scan == *++match && *++scan == *++match &&
1378                 *++scan == *++match && *++scan == *++match &&
1379                 *++scan == *++match && *++scan == *++match &&
1380                 scan < strend);
1381
1382        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1383
1384        len = MAX_MATCH - (int)(strend - scan);
1385        scan = strend - MAX_MATCH;
1386
1387#endif /* UNALIGNED_OK */
1388
1389        if (len > best_len) {
1390            s->match_start = cur_match;
1391            best_len = len;
1392            if (len >= nice_match) break;
1393#ifdef UNALIGNED_OK
1394            scan_end = *(ushf*)(scan+best_len-1);
1395#else
1396            scan_end1  = scan[best_len-1];
1397            scan_end   = scan[best_len];
1398#endif
1399        }
1400    } while ((cur_match = prev[cur_match & wmask]) > limit
1401             && --chain_length != 0);
1402
1403    if ((uInt)best_len <= s->lookahead) return best_len;
1404    return s->lookahead;
1405}
1406#endif /* ASMV */
1407
1408#ifdef DEBUG_ZLIB
1409/* ===========================================================================
1410 * Check that the match at match_start is indeed a match.
1411 */
1412local void check_match(s, start, match, length)
1413    deflate_state *s;
1414    IPos start, match;
1415    int length;
1416{
1417    /* check that the match is indeed a match */
1418    if (zmemcmp((charf *)s->window + match,
1419                (charf *)s->window + start, length) != EQUAL) {
1420        fprintf(stderr, " start %u, match %u, length %d\n",
1421                start, match, length);
1422        do {
1423            fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1424        } while (--length != 0);
1425        z_error("invalid match");
1426    }
1427    if (z_verbose > 1) {
1428        fprintf(stderr,"\\[%d,%d]", start-match, length);
1429        do { putc(s->window[start++], stderr); } while (--length != 0);
1430    }
1431}
1432#else
1433#  define check_match(s, start, match, length)
1434#endif
1435
1436/* ===========================================================================
1437 * Fill the window when the lookahead becomes insufficient.
1438 * Updates strstart and lookahead.
1439 *
1440 * IN assertion: lookahead < MIN_LOOKAHEAD
1441 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1442 *    At least one byte has been read, or avail_in == 0; reads are
1443 *    performed for at least two bytes (required for the zip translate_eol
1444 *    option -- not supported here).
1445 */
1446local void fill_window(s)
1447    deflate_state *s;
1448{
1449    register unsigned n, m;
1450    register Posf *p;
1451    unsigned more;    /* Amount of free space at the end of the window. */
1452    uInt wsize = s->w_size;
1453
1454    do {
1455        more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1456
1457        /* Deal with !@#$% 64K limit: */
1458        if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1459            more = wsize;
1460
1461        } else if (more == (unsigned)(-1)) {
1462            /* Very unlikely, but possible on 16 bit machine if strstart == 0
1463             * and lookahead == 1 (input done one byte at time)
1464             */
1465            more--;
1466
1467        /* If the window is almost full and there is insufficient lookahead,
1468         * move the upper half to the lower one to make room in the upper half.
1469         */
1470        } else if (s->strstart >= wsize+MAX_DIST(s)) {
1471
1472            zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1473                   (unsigned)wsize);
1474            s->match_start -= wsize;
1475            s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
1476            s->block_start -= (long) wsize;
1477
1478            /* Slide the hash table (could be avoided with 32 bit values
1479               at the expense of memory usage). We slide even when level == 0
1480               to keep the hash table consistent if we switch back to level > 0
1481               later. (Using level 0 permanently is not an optimal usage of
1482               zlib, so we don't care about this pathological case.)
1483             */
1484            n = s->hash_size;
1485            p = &s->head[n];
1486            do {
1487                m = *--p;
1488                *p = (Pos)(m >= wsize ? m-wsize : NIL);
1489            } while (--n);
1490
1491            n = wsize;
1492            p = &s->prev[n];
1493            do {
1494                m = *--p;
1495                *p = (Pos)(m >= wsize ? m-wsize : NIL);
1496                /* If n is not on any hash chain, prev[n] is garbage but
1497                 * its value will never be used.
1498                 */
1499            } while (--n);
1500            more += wsize;
1501        }
1502        if (s->strm->avail_in == 0) return;
1503
1504        /* If there was no sliding:
1505         *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1506         *    more == window_size - lookahead - strstart
1507         * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1508         * => more >= window_size - 2*WSIZE + 2
1509         * In the BIG_MEM or MMAP case (not yet supported),
1510         *   window_size == input_size + MIN_LOOKAHEAD  &&
1511         *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1512         * Otherwise, window_size == 2*WSIZE so more >= 2.
1513         * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1514         */
1515        Assert(more >= 2, "more < 2");
1516
1517        n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1518                     more);
1519        s->lookahead += n;
1520
1521        /* Initialize the hash value now that we have some input: */
1522        if (s->lookahead >= MIN_MATCH) {
1523            s->ins_h = s->window[s->strstart];
1524            UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1525#if MIN_MATCH != 3
1526            Call UPDATE_HASH() MIN_MATCH-3 more times
1527#endif
1528        }
1529        /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1530         * but this is not important since only literal bytes will be emitted.
1531         */
1532
1533    } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1534}
1535
1536/* ===========================================================================
1537 * Flush the current block, with given end-of-file flag.
1538 * IN assertion: strstart is set to the end of the current match.
1539 */
1540#define FLUSH_BLOCK_ONLY(s, eof) { \
1541   _tr_flush_block(s, (s->block_start >= 0L ? \
1542                   (charf *)&s->window[(unsigned)s->block_start] : \
1543                   (charf *)Z_NULL), \
1544                (ulg)((long)s->strstart - s->block_start), \
1545                (eof)); \
1546   s->block_start = s->strstart; \
1547   flush_pending(s->strm); \
1548   Tracev((stderr,"[FLUSH]")); \
1549}
1550
1551/* Same but force premature exit if necessary. */
1552#define FLUSH_BLOCK(s, eof) { \
1553   FLUSH_BLOCK_ONLY(s, eof); \
1554   if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1555}
1556
1557/* ===========================================================================
1558 * Copy without compression as much as possible from the input stream, return
1559 * the current block state.
1560 * This function does not insert new strings in the dictionary since
1561 * uncompressible data is probably not useful. This function is used
1562 * only for the level=0 compression option.
1563 * NOTE: this function should be optimized to avoid extra copying from
1564 * window to pending_buf.
1565 */
1566local block_state deflate_stored(s, flush)
1567    deflate_state *s;
1568    int flush;
1569{
1570    /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1571     * to pending_buf_size, and each stored block has a 5 byte header:
1572     */
1573    ulg max_block_size = 0xffff;
1574    ulg max_start;
1575
1576    if (max_block_size > s->pending_buf_size - 5) {
1577        max_block_size = s->pending_buf_size - 5;
1578    }
1579
1580    /* Copy as much as possible from input to output: */
1581    for (;;) {
1582        /* Fill the window as much as possible: */
1583        if (s->lookahead <= 1) {
1584
1585            Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1586                   s->block_start >= (long)s->w_size, "slide too late");
1587
1588            fill_window(s);
1589            if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1590
1591            if (s->lookahead == 0) break; /* flush the current block */
1592        }
1593        Assert(s->block_start >= 0L, "block gone");
1594
1595        s->strstart += s->lookahead;
1596        s->lookahead = 0;
1597
1598        /* Emit a stored block if pending_buf will be full: */
1599        max_start = s->block_start + max_block_size;
1600        if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1601            /* strstart == 0 is possible when wraparound on 16-bit machine */
1602            s->lookahead = (uInt)(s->strstart - max_start);
1603            s->strstart = (uInt)max_start;
1604            FLUSH_BLOCK(s, 0);
1605        }
1606        /* Flush if we may have to slide, otherwise block_start may become
1607         * negative and the data will be gone:
1608         */
1609        if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1610            FLUSH_BLOCK(s, 0);
1611        }
1612    }
1613    FLUSH_BLOCK(s, flush == Z_FINISH);
1614    return flush == Z_FINISH ? finish_done : block_done;
1615}
1616
1617/* ===========================================================================
1618 * Compress as much as possible from the input stream, return the current
1619 * block state.
1620 * This function does not perform lazy evaluation of matches and inserts
1621 * new strings in the dictionary only for unmatched strings or for short
1622 * matches. It is used only for the fast compression options.
1623 */
1624local block_state deflate_fast(s, flush)
1625    deflate_state *s;
1626    int flush;
1627{
1628    IPos hash_head = NIL; /* head of the hash chain */
1629    int bflush;           /* set if current block must be flushed */
1630
1631    for (;;) {
1632        /* Make sure that we always have enough lookahead, except
1633         * at the end of the input file. We need MAX_MATCH bytes
1634         * for the next match, plus MIN_MATCH bytes to insert the
1635         * string following the next match.
1636         */
1637        if (s->lookahead < MIN_LOOKAHEAD) {
1638            fill_window(s);
1639            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1640                return need_more;
1641            }
1642            if (s->lookahead == 0) break; /* flush the current block */
1643        }
1644
1645        /* Insert the string window[strstart .. strstart+2] in the
1646         * dictionary, and set hash_head to the head of the hash chain:
1647         */
1648        if (s->lookahead >= MIN_MATCH) {
1649            INSERT_STRING(s, s->strstart, hash_head);
1650        }
1651
1652        /* Find the longest match, discarding those <= prev_length.
1653         * At this point we have always match_length < MIN_MATCH
1654         */
1655        if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1656            /* To simplify the code, we prevent matches with the string
1657             * of window index 0 (in particular we have to avoid a match
1658             * of the string with itself at the start of the input file).
1659             */
1660            if (s->strategy != Z_HUFFMAN_ONLY) {
1661                s->match_length = longest_match (s, hash_head);
1662            }
1663            /* longest_match() sets match_start */
1664        }
1665        if (s->match_length >= MIN_MATCH) {
1666            check_match(s, s->strstart, s->match_start, s->match_length);
1667
1668            bflush = _tr_tally(s, s->strstart - s->match_start,
1669                               s->match_length - MIN_MATCH);
1670
1671            s->lookahead -= s->match_length;
1672
1673            /* Insert new strings in the hash table only if the match length
1674             * is not too large. This saves time but degrades compression.
1675             */
1676            if (s->match_length <= s->max_insert_length &&
1677                s->lookahead >= MIN_MATCH) {
1678                s->match_length--; /* string at strstart already in hash table */
1679                do {
1680                    s->strstart++;
1681                    INSERT_STRING(s, s->strstart, hash_head);
1682                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1683                     * always MIN_MATCH bytes ahead.
1684                     */
1685                } while (--s->match_length != 0);
1686                s->strstart++;
1687            } else {
1688                s->strstart += s->match_length;
1689                s->match_length = 0;
1690                s->ins_h = s->window[s->strstart];
1691                UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1692#if MIN_MATCH != 3
1693                Call UPDATE_HASH() MIN_MATCH-3 more times
1694#endif
1695                /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1696                 * matter since it will be recomputed at next deflate call.
1697                 */
1698            }
1699        } else {
1700            /* No match, output a literal byte */
1701            Tracevv((stderr,"%c", s->window[s->strstart]));
1702            bflush = _tr_tally (s, 0, s->window[s->strstart]);
1703            s->lookahead--;
1704            s->strstart++;
1705        }
1706        if (bflush) FLUSH_BLOCK(s, 0);
1707    }
1708    FLUSH_BLOCK(s, flush == Z_FINISH);
1709    return flush == Z_FINISH ? finish_done : block_done;
1710}
1711
1712/* ===========================================================================
1713 * Same as above, but achieves better compression. We use a lazy
1714 * evaluation for matches: a match is finally adopted only if there is
1715 * no better match at the next window position.
1716 */
1717local block_state deflate_slow(s, flush)
1718    deflate_state *s;
1719    int flush;
1720{
1721    IPos hash_head = NIL;    /* head of hash chain */
1722    int bflush;              /* set if current block must be flushed */
1723
1724    /* Process the input block. */
1725    for (;;) {
1726        /* Make sure that we always have enough lookahead, except
1727         * at the end of the input file. We need MAX_MATCH bytes
1728         * for the next match, plus MIN_MATCH bytes to insert the
1729         * string following the next match.
1730         */
1731        if (s->lookahead < MIN_LOOKAHEAD) {
1732            fill_window(s);
1733            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1734                return need_more;
1735            }
1736            if (s->lookahead == 0) break; /* flush the current block */
1737        }
1738
1739        /* Insert the string window[strstart .. strstart+2] in the
1740         * dictionary, and set hash_head to the head of the hash chain:
1741         */
1742        if (s->lookahead >= MIN_MATCH) {
1743            INSERT_STRING(s, s->strstart, hash_head);
1744        }
1745
1746        /* Find the longest match, discarding those <= prev_length.
1747         */
1748        s->prev_length = s->match_length, s->prev_match = s->match_start;
1749        s->match_length = MIN_MATCH-1;
1750
1751        if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1752            s->strstart - hash_head <= MAX_DIST(s)) {
1753            /* To simplify the code, we prevent matches with the string
1754             * of window index 0 (in particular we have to avoid a match
1755             * of the string with itself at the start of the input file).
1756             */
1757            if (s->strategy != Z_HUFFMAN_ONLY) {
1758                s->match_length = longest_match (s, hash_head);
1759            }
1760            /* longest_match() sets match_start */
1761
1762            if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1763                 (s->match_length == MIN_MATCH &&
1764                  s->strstart - s->match_start > TOO_FAR))) {
1765
1766                /* If prev_match is also MIN_MATCH, match_start is garbage
1767                 * but we will ignore the current match anyway.
1768                 */
1769                s->match_length = MIN_MATCH-1;
1770            }
1771        }
1772        /* If there was a match at the previous step and the current
1773         * match is not better, output the previous match:
1774         */
1775        if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1776            uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1777            /* Do not insert strings in hash table beyond this. */
1778
1779            check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1780
1781            bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
1782                               s->prev_length - MIN_MATCH);
1783
1784            /* Insert in hash table all strings up to the end of the match.
1785             * strstart-1 and strstart are already inserted. If there is not
1786             * enough lookahead, the last two strings are not inserted in
1787             * the hash table.
1788             */
1789            s->lookahead -= s->prev_length-1;
1790            s->prev_length -= 2;
1791            do {
1792                if (++s->strstart <= max_insert) {
1793                    INSERT_STRING(s, s->strstart, hash_head);
1794                }
1795            } while (--s->prev_length != 0);
1796            s->match_available = 0;
1797            s->match_length = MIN_MATCH-1;
1798            s->strstart++;
1799
1800            if (bflush) FLUSH_BLOCK(s, 0);
1801
1802        } else if (s->match_available) {
1803            /* If there was no match at the previous position, output a
1804             * single literal. If there was a match but the current match
1805             * is longer, truncate the previous match to a single literal.
1806             */
1807            Tracevv((stderr,"%c", s->window[s->strstart-1]));
1808            if (_tr_tally (s, 0, s->window[s->strstart-1])) {
1809                FLUSH_BLOCK_ONLY(s, 0);
1810            }
1811            s->strstart++;
1812            s->lookahead--;
1813            if (s->strm->avail_out == 0) return need_more;
1814        } else {
1815            /* There is no previous match to compare with, wait for
1816             * the next step to decide.
1817             */
1818            s->match_available = 1;
1819            s->strstart++;
1820            s->lookahead--;
1821        }
1822    }
1823    Assert (flush != Z_NO_FLUSH, "no flush?");
1824    if (s->match_available) {
1825        Tracevv((stderr,"%c", s->window[s->strstart-1]));
1826        _tr_tally (s, 0, s->window[s->strstart-1]);
1827        s->match_available = 0;
1828    }
1829    FLUSH_BLOCK(s, flush == Z_FINISH);
1830    return flush == Z_FINISH ? finish_done : block_done;
1831}
1832/* --- deflate.c */
1833
1834/* +++ trees.c */
1835/* trees.c -- output deflated data using Huffman coding
1836 * Copyright (C) 1995-1996 Jean-loup Gailly
1837 * For conditions of distribution and use, see copyright notice in zlib.h
1838 */
1839
1840/*
1841 *  ALGORITHM
1842 *
1843 *      The "deflation" process uses several Huffman trees. The more
1844 *      common source values are represented by shorter bit sequences.
1845 *
1846 *      Each code tree is stored in a compressed form which is itself
1847 * a Huffman encoding of the lengths of all the code strings (in
1848 * ascending order by source values).  The actual code strings are
1849 * reconstructed from the lengths in the inflate process, as described
1850 * in the deflate specification.
1851 *
1852 *  REFERENCES
1853 *
1854 *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1855 *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1856 *
1857 *      Storer, James A.
1858 *          Data Compression:  Methods and Theory, pp. 49-50.
1859 *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
1860 *
1861 *      Sedgewick, R.
1862 *          Algorithms, p290.
1863 *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
1864 */
1865
1866/* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
1867
1868/* #include "deflate.h" */
1869
1870#ifdef DEBUG_ZLIB
1871#  include <ctype.h>
1872#endif
1873
1874/* ===========================================================================
1875 * Constants
1876 */
1877
1878#define MAX_BL_BITS 7
1879/* Bit length codes must not exceed MAX_BL_BITS bits */
1880
1881#define END_BLOCK 256
1882/* end of block literal code */
1883
1884#define REP_3_6      16
1885/* repeat previous bit length 3-6 times (2 bits of repeat count) */
1886
1887#define REPZ_3_10    17
1888/* repeat a zero length 3-10 times  (3 bits of repeat count) */
1889
1890#define REPZ_11_138  18
1891/* repeat a zero length 11-138 times  (7 bits of repeat count) */
1892
1893local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1894   = {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};
1895
1896local int extra_dbits[D_CODES] /* extra bits for each distance code */
1897   = {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};
1898
1899local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1900   = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1901
1902local uch bl_order[BL_CODES]
1903   = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1904/* The lengths of the bit length codes are sent in order of decreasing
1905 * probability, to avoid transmitting the lengths for unused bit length codes.
1906 */
1907
1908#define Buf_size (8 * 2*sizeof(char))
1909/* Number of bits used within bi_buf. (bi_buf might be implemented on
1910 * more than 16 bits on some systems.)
1911 */
1912
1913/* ===========================================================================
1914 * Local data. These are initialized only once.
1915 */
1916
1917local ct_data static_ltree[L_CODES+2];
1918/* The static literal tree. Since the bit lengths are imposed, there is no
1919 * need for the L_CODES extra codes used during heap construction. However
1920 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
1921 * below).
1922 */
1923
1924local ct_data static_dtree[D_CODES];
1925/* The static distance tree. (Actually a trivial tree since all codes use
1926 * 5 bits.)
1927 */
1928
1929local uch dist_code[512];
1930/* distance codes. The first 256 values correspond to the distances
1931 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1932 * the 15 bit distances.
1933 */
1934
1935local uch length_code[MAX_MATCH-MIN_MATCH+1];
1936/* length code for each normalized match length (0 == MIN_MATCH) */
1937
1938local int base_length[LENGTH_CODES];
1939/* First normalized length for each code (0 = MIN_MATCH) */
1940
1941local int base_dist[D_CODES];
1942/* First normalized distance for each code (0 = distance of 1) */
1943
1944struct static_tree_desc_s {
1945    ct_data *static_tree;        /* static tree or NULL */
1946    intf    *extra_bits;         /* extra bits for each code or NULL */
1947    int     extra_base;          /* base index for extra_bits */
1948    int     elems;               /* max number of elements in the tree */
1949    int     max_length;          /* max bit length for the codes */
1950};
1951
1952local static_tree_desc  static_l_desc =
1953{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1954
1955local static_tree_desc  static_d_desc =
1956{static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};
1957
1958local static_tree_desc  static_bl_desc =
1959{(ct_data *)0, extra_blbits, 0,      BL_CODES, MAX_BL_BITS};
1960
1961/* ===========================================================================
1962 * Local (static) routines in this file.
1963 */
1964
1965local void tr_static_init OF((void));
1966local void init_block     OF((deflate_state *s));
1967local void pqdownheap     OF((deflate_state *s, ct_data *tree, int k));
1968local void gen_bitlen     OF((deflate_state *s, tree_desc *desc));
1969local void gen_codes      OF((ct_data *tree, int max_code, ushf *bl_count));
1970local void build_tree     OF((deflate_state *s, tree_desc *desc));
1971local void scan_tree      OF((deflate_state *s, ct_data *tree, int max_code));
1972local void send_tree      OF((deflate_state *s, ct_data *tree, int max_code));
1973local int  build_bl_tree  OF((deflate_state *s));
1974local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1975                              int blcodes));
1976local void compress_block OF((deflate_state *s, ct_data *ltree,
1977                              ct_data *dtree));
1978local void set_data_type  OF((deflate_state *s));
1979local unsigned bi_reverse OF((unsigned value, int length));
1980local void bi_windup      OF((deflate_state *s));
1981local void bi_flush       OF((deflate_state *s));
1982local void copy_block     OF((deflate_state *s, charf *buf, unsigned len,
1983                              int header));
1984
1985#ifndef DEBUG_ZLIB
1986#  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1987   /* Send a code of the given tree. c and tree must not have side effects */
1988
1989#else /* DEBUG_ZLIB */
1990#  define send_code(s, c, tree) \
1991     { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
1992       send_bits(s, tree[c].Code, tree[c].Len); }
1993#endif
1994
1995#define d_code(dist) \
1996   ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1997/* Mapping from a distance to a distance code. dist is the distance - 1 and
1998 * must not have side effects. dist_code[256] and dist_code[257] are never
1999 * used.
2000 */
2001
2002/* ===========================================================================
2003 * Output a short LSB first on the stream.
2004 * IN assertion: there is enough room in pendingBuf.
2005 */
2006#define put_short(s, w) { \
2007    put_byte(s, (uch)((w) & 0xff)); \
2008    put_byte(s, (uch)((ush)(w) >> 8)); \
2009}
2010
2011/* ===========================================================================
2012 * Send a value on a given number of bits.
2013 * IN assertion: length <= 16 and value fits in length bits.
2014 */
2015#ifdef DEBUG_ZLIB
2016local void send_bits      OF((deflate_state *s, int value, int length));
2017
2018local void send_bits(s, value, length)
2019    deflate_state *s;
2020    int value;  /* value to send */
2021    int length; /* number of bits */
2022{
2023    Tracevv((stderr," l %2d v %4x ", length, value));
2024    Assert(length > 0 && length <= 15, "invalid length");
2025    s->bits_sent += (ulg)length;
2026
2027    /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2028     * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2029     * unused bits in value.
2030     */
2031    if (s->bi_valid > (int)Buf_size - length) {
2032        s->bi_buf |= (value << s->bi_valid);
2033        put_short(s, s->bi_buf);
2034        s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2035        s->bi_valid += length - Buf_size;
2036    } else {
2037        s->bi_buf |= value << s->bi_valid;
2038        s->bi_valid += length;
2039    }
2040}
2041#else /* !DEBUG_ZLIB */
2042
2043#define send_bits(s, value, length) \
2044{ int len = length;\
2045  if (s->bi_valid > (int)Buf_size - len) {\
2046    int val = value;\
2047    s->bi_buf |= (val << s->bi_valid);\
2048    put_short(s, s->bi_buf);\
2049    s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2050    s->bi_valid += len - Buf_size;\
2051  } else {\
2052    s->bi_buf |= (value) << s->bi_valid;\
2053    s->bi_valid += len;\
2054  }\
2055}
2056#endif /* DEBUG_ZLIB */
2057
2058
2059#define MAX(a,b) (a >= b ? a : b)
2060/* the arguments must not have side effects */
2061
2062/* ===========================================================================
2063 * Initialize the various 'constant' tables. In a multi-threaded environment,
2064 * this function may be called by two threads concurrently, but this is
2065 * harmless since both invocations do exactly the same thing.
2066 */
2067local void tr_static_init()
2068{
2069    static int static_init_done = 0;
2070    int n;        /* iterates over tree elements */
2071    int bits;     /* bit counter */
2072    int length;   /* length value */
2073    int code;     /* code value */
2074    int dist;     /* distance index */
2075    ush bl_count[MAX_BITS+1];
2076    /* number of codes at each bit length for an optimal tree */
2077
2078    if (static_init_done) return;
2079
2080    /* Initialize the mapping length (0..255) -> length code (0..28) */
2081    length = 0;
2082    for (code = 0; code < LENGTH_CODES-1; code++) {
2083        base_length[code] = length;
2084        for (n = 0; n < (1<<extra_lbits[code]); n++) {
2085            length_code[length++] = (uch)code;
2086        }
2087    }
2088    Assert (length == 256, "tr_static_init: length != 256");
2089    /* Note that the length 255 (match length 258) can be represented
2090     * in two different ways: code 284 + 5 bits or code 285, so we
2091     * overwrite length_code[255] to use the best encoding:
2092     */
2093    length_code[length-1] = (uch)code;
2094
2095    /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2096    dist = 0;
2097    for (code = 0 ; code < 16; code++) {
2098        base_dist[code] = dist;
2099        for (n = 0; n < (1<<extra_dbits[code]); n++) {
2100            dist_code[dist++] = (uch)code;
2101        }
2102    }
2103    Assert (dist == 256, "tr_static_init: dist != 256");
2104    dist >>= 7; /* from now on, all distances are divided by 128 */
2105    for ( ; code < D_CODES; code++) {
2106        base_dist[code] = dist << 7;
2107        for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2108            dist_code[256 + dist++] = (uch)code;
2109        }
2110    }
2111    Assert (dist == 256, "tr_static_init: 256+dist != 512");
2112
2113    /* Construct the codes of the static literal tree */
2114    for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2115    n = 0;
2116    while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2117    while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2118    while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2119    while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2120    /* Codes 286 and 287 do not exist, but we must include them in the
2121     * tree construction to get a canonical Huffman tree (longest code
2122     * all ones)
2123     */
2124    gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2125
2126    /* The static distance tree is trivial: */
2127    for (n = 0; n < D_CODES; n++) {
2128        static_dtree[n].Len = 5;
2129        static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2130    }
2131    static_init_done = 1;
2132}
2133
2134/* ===========================================================================
2135 * Initialize the tree data structures for a new zlib stream.
2136 */
2137void _tr_init(s)
2138    deflate_state *s;
2139{
2140    tr_static_init();
2141
2142    s->compressed_len = 0L;
2143
2144    s->l_desc.dyn_tree = s->dyn_ltree;
2145    s->l_desc.stat_desc = &static_l_desc;
2146
2147    s->d_desc.dyn_tree = s->dyn_dtree;
2148    s->d_desc.stat_desc = &static_d_desc;
2149
2150    s->bl_desc.dyn_tree = s->bl_tree;
2151    s->bl_desc.stat_desc = &static_bl_desc;
2152
2153    s->bi_buf = 0;
2154    s->bi_valid = 0;
2155    s->last_eob_len = 8; /* enough lookahead for inflate */
2156#ifdef DEBUG_ZLIB
2157    s->bits_sent = 0L;
2158#endif
2159
2160    /* Initialize the first block of the first file: */
2161    init_block(s);
2162}
2163
2164/* ===========================================================================
2165 * Initialize a new block.
2166 */
2167local void init_block(s)
2168    deflate_state *s;
2169{
2170    int n; /* iterates over tree elements */
2171
2172    /* Initialize the trees. */
2173    for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
2174    for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
2175    for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2176
2177    s->dyn_ltree[END_BLOCK].Freq = 1;
2178    s->opt_len = s->static_len = 0L;
2179    s->last_lit = s->matches = 0;
2180}
2181
2182#define SMALLEST 1
2183/* Index within the heap array of least frequent node in the Huffman tree */
2184
2185
2186/* ===========================================================================
2187 * Remove the smallest element from the heap and recreate the heap with
2188 * one less element. Updates heap and heap_len.
2189 */
2190#define pqremove(s, tree, top) \
2191{\
2192    top = s->heap[SMALLEST]; \
2193    s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2194    pqdownheap(s, tree, SMALLEST); \
2195}
2196
2197/* ===========================================================================
2198 * Compares to subtrees, using the tree depth as tie breaker when
2199 * the subtrees have equal frequency. This minimizes the worst case length.
2200 */
2201#define smaller(tree, n, m, depth) \
2202   (tree[n].Freq < tree[m].Freq || \
2203   (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2204
2205/* ===========================================================================
2206 * Restore the heap property by moving down the tree starting at node k,
2207 * exchanging a node with the smallest of its two sons if necessary, stopping
2208 * when the heap property is re-established (each father smaller than its
2209 * two sons).
2210 */
2211local void pqdownheap(s, tree, k)
2212    deflate_state *s;
2213    ct_data *tree;  /* the tree to restore */
2214    int k;               /* node to move down */
2215{
2216    int v = s->heap[k];
2217    int j = k << 1;  /* left son of k */
2218    while (j <= s->heap_len) {
2219        /* Set j to the smallest of the two sons: */
2220        if (j < s->heap_len &&
2221            smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2222            j++;
2223        }
2224        /* Exit if v is smaller than both sons */
2225        if (smaller(tree, v, s->heap[j], s->depth)) break;
2226
2227        /* Exchange v with the smallest son */
2228        s->heap[k] = s->heap[j];  k = j;
2229
2230        /* And continue down the tree, setting j to the left son of k */
2231        j <<= 1;
2232    }
2233    s->heap[k] = v;
2234}
2235
2236/* ===========================================================================
2237 * Compute the optimal bit lengths for a tree and update the total bit length
2238 * for the current block.
2239 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2240 *    above are the tree nodes sorted by increasing frequency.
2241 * OUT assertions: the field len is set to the optimal bit length, the
2242 *     array bl_count contains the frequencies for each bit length.
2243 *     The length opt_len is updated; static_len is also updated if stree is
2244 *     not null.
2245 */
2246local void gen_bitlen(s, desc)
2247    deflate_state *s;
2248    tree_desc *desc;    /* the tree descriptor */
2249{
2250    ct_data *tree  = desc->dyn_tree;
2251    int max_code   = desc->max_code;
2252    ct_data *stree = desc->stat_desc->static_tree;
2253    intf *extra    = desc->stat_desc->extra_bits;
2254    int base       = desc->stat_desc->extra_base;
2255    int max_length = desc->stat_desc->max_length;
2256    int h;              /* heap index */
2257    int n, m;           /* iterate over the tree elements */
2258    int bits;           /* bit length */
2259    int xbits;          /* extra bits */
2260    ush f;              /* frequency */
2261    int overflow = 0;   /* number of elements with bit length too large */
2262
2263    for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2264
2265    /* In a first pass, compute the optimal bit lengths (which may
2266     * overflow in the case of the bit length tree).
2267     */
2268    tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2269
2270    for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2271        n = s->heap[h];
2272        bits = tree[tree[n].Dad].Len + 1;
2273        if (bits > max_length) bits = max_length, overflow++;
2274        tree[n].Len = (ush)bits;
2275        /* We overwrite tree[n].Dad which is no longer needed */
2276
2277        if (n > max_code) continue; /* not a leaf node */
2278
2279        s->bl_count[bits]++;
2280        xbits = 0;
2281        if (n >= base) xbits = extra[n-base];
2282        f = tree[n].Freq;
2283        s->opt_len += (ulg)f * (bits + xbits);
2284        if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2285    }
2286    if (overflow == 0) return;
2287
2288    Trace((stderr,"\nbit length overflow\n"));
2289    /* This happens for example on obj2 and pic of the Calgary corpus */
2290
2291    /* Find the first bit length which could increase: */
2292    do {
2293        bits = max_length-1;
2294        while (s->bl_count[bits] == 0) bits--;
2295        s->bl_count[bits]--;      /* move one leaf down the tree */
2296        s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2297        s->bl_count[max_length]--;
2298        /* The brother of the overflow item also moves one step up,
2299         * but this does not affect bl_count[max_length]
2300         */
2301        overflow -= 2;
2302    } while (overflow > 0);
2303
2304    /* Now recompute all bit lengths, scanning in increasing frequency.
2305     * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2306     * lengths instead of fixing only the wrong ones. This idea is taken
2307     * from 'ar' written by Haruhiko Okumura.)
2308     */
2309    for (bits = max_length; bits != 0; bits--) {
2310        n = s->bl_count[bits];
2311        while (n != 0) {
2312            m = s->heap[--h];
2313            if (m > max_code) continue;
2314            if (tree[m].Len != (unsigned) bits) {
2315                Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2316                s->opt_len += ((long)bits - (long)tree[m].Len)
2317                              *(long)tree[m].Freq;
2318                tree[m].Len = (ush)bits;
2319            }
2320            n--;
2321        }
2322    }
2323}
2324
2325/* ===========================================================================
2326 * Generate the codes for a given tree and bit counts (which need not be
2327 * optimal).
2328 * IN assertion: the array bl_count contains the bit length statistics for
2329 * the given tree and the field len is set for all tree elements.
2330 * OUT assertion: the field code is set for all tree elements of non
2331 *     zero code length.
2332 */
2333local void gen_codes (tree, max_code, bl_count)
2334    ct_data *tree;             /* the tree to decorate */
2335    int max_code;              /* largest code with non zero frequency */
2336    ushf *bl_count;            /* number of codes at each bit length */
2337{
2338    ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2339    ush code = 0;              /* running code value */
2340    int bits;                  /* bit index */
2341    int n;                     /* code index */
2342
2343    /* The distribution counts are first used to generate the code values
2344     * without bit reversal.
2345     */
2346    for (bits = 1; bits <= MAX_BITS; bits++) {
2347        next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2348    }
2349    /* Check that the bit counts in bl_count are consistent. The last code
2350     * must be all ones.
2351     */
2352    Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2353            "inconsistent bit counts");
2354    Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2355
2356    for (n = 0;  n <= max_code; n++) {
2357        int len = tree[n].Len;
2358        if (len == 0) continue;
2359        /* Now reverse the bits */
2360        tree[n].Code = bi_reverse(next_code[len]++, len);
2361
2362        Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2363             n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2364    }
2365}
2366
2367/* ===========================================================================
2368 * Construct one Huffman tree and assigns the code bit strings and lengths.
2369 * Update the total bit length for the current block.
2370 * IN assertion: the field freq is set for all tree elements.
2371 * OUT assertions: the fields len and code are set to the optimal bit length
2372 *     and corresponding code. The length opt_len is updated; static_len is
2373 *     also updated if stree is not null. The field max_code is set.
2374 */
2375local void build_tree(s, desc)
2376    deflate_state *s;
2377    tree_desc *desc; /* the tree descriptor */
2378{
2379    ct_data *tree   = desc->dyn_tree;
2380    ct_data *stree  = desc->stat_desc->static_tree;
2381    int elems       = desc->stat_desc->elems;
2382    int n, m;          /* iterate over heap elements */
2383    int max_code = -1; /* largest code with non zero frequency */
2384    int node;          /* new node being created */
2385
2386    /* Construct the initial heap, with least frequent element in
2387     * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2388     * heap[0] is not used.
2389     */
2390    s->heap_len = 0, s->heap_max = HEAP_SIZE;
2391
2392    for (n = 0; n < elems; n++) {
2393        if (tree[n].Freq != 0) {
2394            s->heap[++(s->heap_len)] = max_code = n;
2395            s->depth[n] = 0;
2396        } else {
2397            tree[n].Len = 0;
2398        }
2399    }
2400
2401    /* The pkzip format requires that at least one distance code exists,
2402     * and that at least one bit should be sent even if there is only one
2403     * possible code. So to avoid special checks later on we force at least
2404     * two codes of non zero frequency.
2405     */
2406    while (s->heap_len < 2) {
2407        node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2408        tree[node].Freq = 1;
2409        s->depth[node] = 0;
2410        s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2411        /* node is 0 or 1 so it does not have extra bits */
2412    }
2413    desc->max_code = max_code;
2414
2415    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2416     * establish sub-heaps of increasing lengths:
2417     */
2418    for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2419
2420    /* Construct the Huffman tree by repeatedly combining the least two
2421     * frequent nodes.
2422     */
2423    node = elems;              /* next internal node of the tree */
2424    do {
2425        pqremove(s, tree, n);  /* n = node of least frequency */
2426        m = s->heap[SMALLEST]; /* m = node of next least frequency */
2427
2428        s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2429        s->heap[--(s->heap_max)] = m;
2430
2431        /* Create a new node father of n and m */
2432        tree[node].Freq = tree[n].Freq + tree[m].Freq;
2433        s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2434        tree[n].Dad = tree[m].Dad = (ush)node;
2435#ifdef DUMP_BL_TREE
2436        if (tree == s->bl_tree) {
2437            fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2438                    node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2439        }
2440#endif
2441        /* and insert the new node in the heap */
2442        s->heap[SMALLEST] = node++;
2443        pqdownheap(s, tree, SMALLEST);
2444
2445    } while (s->heap_len >= 2);
2446
2447    s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2448
2449    /* At this point, the fields freq and dad are set. We can now
2450     * generate the bit lengths.
2451     */
2452    gen_bitlen(s, (tree_desc *)desc);
2453
2454    /* The field len is now set, we can generate the bit codes */
2455    gen_codes ((ct_data *)tree, max_code, s->bl_count);
2456}
2457
2458/* ===========================================================================
2459 * Scan a literal or distance tree to determine the frequencies of the codes
2460 * in the bit length tree.
2461 */
2462local void scan_tree (s, tree, max_code)
2463    deflate_state *s;
2464    ct_data *tree;   /* the tree to be scanned */
2465    int max_code;    /* and its largest code of non zero frequency */
2466{
2467    int n;                     /* iterates over all tree elements */
2468    int prevlen = -1;          /* last emitted length */
2469    int curlen;                /* length of current code */
2470    int nextlen = tree[0].Len; /* length of next code */
2471    int count = 0;             /* repeat count of the current code */
2472    int max_count = 7;         /* max repeat count */
2473    int min_count = 4;         /* min repeat count */
2474
2475    if (nextlen == 0) max_count = 138, min_count = 3;
2476    tree[max_code+1].Len = (ush)0xffff; /* guard */
2477
2478    for (n = 0; n <= max_code; n++) {
2479        curlen = nextlen; nextlen = tree[n+1].Len;
2480        if (++count < max_count && curlen == nextlen) {
2481            continue;
2482        } else if (count < min_count) {
2483            s->bl_tree[curlen].Freq += count;
2484        } else if (curlen != 0) {
2485            if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2486            s->bl_tree[REP_3_6].Freq++;
2487        } else if (count <= 10) {
2488            s->bl_tree[REPZ_3_10].Freq++;
2489        } else {
2490            s->bl_tree[REPZ_11_138].Freq++;
2491        }
2492        count = 0; prevlen = curlen;
2493        if (nextlen == 0) {
2494            max_count = 138, min_count = 3;
2495        } else if (curlen == nextlen) {
2496            max_count = 6, min_count = 3;
2497        } else {
2498            max_count = 7, min_count = 4;
2499        }
2500    }
2501}
2502
2503/* ===========================================================================
2504 * Send a literal or distance tree in compressed form, using the codes in
2505 * bl_tree.
2506 */
2507local void send_tree (s, tree, max_code)
2508    deflate_state *s;
2509    ct_data *tree; /* the tree to be scanned */
2510    int max_code;       /* and its largest code of non zero frequency */
2511{
2512    int n;                     /* iterates over all tree elements */
2513    int prevlen = -1;          /* last emitted length */
2514    int curlen;                /* length of current code */
2515    int nextlen = tree[0].Len; /* length of next code */
2516    int count = 0;             /* repeat count of the current code */
2517    int max_count = 7;         /* max repeat count */
2518    int min_count = 4;         /* min repeat count */
2519
2520    /* tree[max_code+1].Len = -1; */  /* guard already set */
2521    if (nextlen == 0) max_count = 138, min_count = 3;
2522
2523    for (n = 0; n <= max_code; n++) {
2524        curlen = nextlen; nextlen = tree[n+1].Len;
2525        if (++count < max_count && curlen == nextlen) {
2526            continue;
2527        } else if (count < min_count) {
2528            do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2529
2530        } else if (curlen != 0) {
2531            if (curlen != prevlen) {
2532                send_code(s, curlen, s->bl_tree); count--;
2533            }
2534            Assert(count >= 3 && count <= 6, " 3_6?");
2535            send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2536
2537        } else if (count <= 10) {
2538            send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2539
2540        } else {
2541            send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2542        }
2543        count = 0; prevlen = curlen;
2544        if (nextlen == 0) {
2545            max_count = 138, min_count = 3;
2546        } else if (curlen == nextlen) {
2547            max_count = 6, min_count = 3;
2548        } else {
2549            max_count = 7, min_count = 4;
2550        }
2551    }
2552}
2553
2554/* ===========================================================================
2555 * Construct the Huffman tree for the bit lengths and return the index in
2556 * bl_order of the last bit length code to send.
2557 */
2558local int build_bl_tree(s)
2559    deflate_state *s;
2560{
2561    int max_blindex;  /* index of last bit length code of non zero freq */
2562
2563    /* Determine the bit length frequencies for literal and distance trees */
2564    scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2565    scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2566
2567    /* Build the bit length tree: */
2568    build_tree(s, (tree_desc *)(&(s->bl_desc)));
2569    /* opt_len now includes the length of the tree representations, except
2570     * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2571     */
2572
2573    /* Determine the number of bit length codes to send. The pkzip format
2574     * requires that at least 4 bit length codes be sent. (appnote.txt says
2575     * 3 but the actual value used is 4.)
2576     */
2577    for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2578        if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2579    }
2580    /* Update opt_len to include the bit length tree and counts */
2581    s->opt_len += 3*(max_blindex+1) + 5+5+4;
2582    Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2583            s->opt_len, s->static_len));
2584
2585    return max_blindex;
2586}
2587
2588/* ===========================================================================
2589 * Send the header for a block using dynamic Huffman trees: the counts, the
2590 * lengths of the bit length codes, the literal tree and the distance tree.
2591 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2592 */
2593local void send_all_trees(s, lcodes, dcodes, blcodes)
2594    deflate_state *s;
2595    int lcodes, dcodes, blcodes; /* number of codes for each tree */
2596{
2597    int rank;                    /* index in bl_order */
2598
2599    Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2600    Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2601            "too many codes");
2602    Tracev((stderr, "\nbl counts: "));
2603    send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2604    send_bits(s, dcodes-1,   5);
2605    send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */
2606    for (rank = 0; rank < blcodes; rank++) {
2607        Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2608        send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2609    }
2610    Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2611
2612    send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2613    Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2614
2615    send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2616    Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2617}
2618
2619/* ===========================================================================
2620 * Send a stored block
2621 */
2622void _tr_stored_block(s, buf, stored_len, eof)
2623    deflate_state *s;
2624    charf *buf;       /* input block */
2625    ulg stored_len;   /* length of input block */
2626    int eof;          /* true if this is the last block for a file */
2627{
2628    send_bits(s, (STORED_BLOCK<<1)+eof, 3);  /* send block type */
2629    s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
2630    s->compressed_len += (stored_len + 4) << 3;
2631
2632    copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2633}
2634
2635/* Send just the `stored block' type code without any length bytes or data.
2636 */
2637void _tr_stored_type_only(s)
2638    deflate_state *s;
2639{
2640    send_bits(s, (STORED_BLOCK << 1), 3);
2641    bi_windup(s);
2642    s->compressed_len = (s->compressed_len + 3) & ~7L;
2643}
2644
2645
2646/* ===========================================================================
2647 * Send one empty static block to give enough lookahead for inflate.
2648 * This takes 10 bits, of which 7 may remain in the bit buffer.
2649 * The current inflate code requires 9 bits of lookahead. If the
2650 * last two codes for the previous block (real code plus EOB) were coded
2651 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
2652 * the last real code. In this case we send two empty static blocks instead
2653 * of one. (There are no problems if the previous block is stored or fixed.)
2654 * To simplify the code, we assume the worst case of last real code encoded
2655 * on one bit only.
2656 */
2657void _tr_align(s)
2658    deflate_state *s;
2659{
2660    send_bits(s, STATIC_TREES<<1, 3);
2661    send_code(s, END_BLOCK, static_ltree);
2662    s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2663    bi_flush(s);
2664    /* Of the 10 bits for the empty block, we have already sent
2665     * (10 - bi_valid) bits. The lookahead for the last real code (before
2666     * the EOB of the previous block) was thus at least one plus the length
2667     * of the EOB plus what we have just sent of the empty static block.
2668     */
2669    if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
2670        send_bits(s, STATIC_TREES<<1, 3);
2671        send_code(s, END_BLOCK, static_ltree);
2672        s->compressed_len += 10L;
2673        bi_flush(s);
2674    }
2675    s->last_eob_len = 7;
2676}
2677
2678/* ===========================================================================
2679 * Determine the best encoding for the current block: dynamic trees, static
2680 * trees or store, and output the encoded block to the zip file. This function
2681 * returns the total compressed length for the file so far.
2682 */
2683ulg _tr_flush_block(s, buf, stored_len, eof)
2684    deflate_state *s;
2685    charf *buf;       /* input block, or NULL if too old */
2686    ulg stored_len;   /* length of input block */
2687    int eof;          /* true if this is the last block for a file */
2688{
2689    ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2690    int max_blindex = 0;  /* index of last bit length code of non zero freq */
2691
2692    /* Build the Huffman trees unless a stored block is forced */
2693    if (s->level > 0) {
2694
2695         /* Check if the file is ascii or binary */
2696        if (s->data_type == Z_UNKNOWN) set_data_type(s);
2697
2698        /* Construct the literal and distance trees */
2699        build_tree(s, (tree_desc *)(&(s->l_desc)));
2700        Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2701                s->static_len));
2702
2703        build_tree(s, (tree_desc *)(&(s->d_desc)));
2704        Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2705                s->static_len));
2706        /* At this point, opt_len and static_len are the total bit lengths of
2707         * the compressed block data, excluding the tree representations.
2708         */
2709
2710        /* Build the bit length tree for the above two trees, and get the index
2711         * in bl_order of the last bit length code to send.
2712         */
2713        max_blindex = build_bl_tree(s);
2714
2715        /* Determine the best encoding. Compute first the block length in bytes*/
2716        opt_lenb = (s->opt_len+3+7)>>3;
2717        static_lenb = (s->static_len+3+7)>>3;
2718
2719        Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2720                opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2721                s->last_lit));
2722
2723        if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2724
2725    } else {
2726        Assert(buf != (char*)0, "lost buf");
2727        opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
2728    }
2729
2730    /* If compression failed and this is the first and last block,
2731     * and if the .zip file can be seeked (to rewrite the local header),
2732     * the whole file is transformed into a stored file:
2733     */
2734#ifdef STORED_FILE_OK
2735#  ifdef FORCE_STORED_FILE
2736    if (eof && s->compressed_len == 0L) { /* force stored file */
2737#  else
2738    if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
2739#  endif
2740        /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2741        if (buf == (charf*)0) error ("block vanished");
2742
2743        copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
2744        s->compressed_len = stored_len << 3;
2745        s->method = STORED;
2746    } else
2747#endif /* STORED_FILE_OK */
2748
2749#ifdef FORCE_STORED
2750    if (buf != (char*)0) { /* force stored block */
2751#else
2752    if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2753                       /* 4: two words for the lengths */
2754#endif
2755        /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2756         * Otherwise we can't have processed more than WSIZE input bytes since
2757         * the last block flush, because compression would have been
2758         * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2759         * transform a block into a stored block.
2760         */
2761        _tr_stored_block(s, buf, stored_len, eof);
2762
2763#ifdef FORCE_STATIC
2764    } else if (static_lenb >= 0) { /* force static trees */
2765#else
2766    } else if (static_lenb == opt_lenb) {
2767#endif
2768        send_bits(s, (STATIC_TREES<<1)+eof, 3);
2769        compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2770        s->compressed_len += 3 + s->static_len;
2771    } else {
2772        send_bits(s, (DYN_TREES<<1)+eof, 3);
2773        send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2774                       max_blindex+1);
2775        compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2776        s->compressed_len += 3 + s->opt_len;
2777    }
2778    Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2779    init_block(s);
2780
2781    if (eof) {
2782        bi_windup(s);
2783        s->compressed_len += 7;  /* align on byte boundary */
2784    }
2785    Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2786           s->compressed_len-7*eof));
2787
2788    return s->compressed_len >> 3;
2789}
2790
2791/* ===========================================================================
2792 * Save the match info and tally the frequency counts. Return true if
2793 * the current block must be flushed.
2794 */
2795int _tr_tally (s, dist, lc)
2796    deflate_state *s;
2797    unsigned dist;  /* distance of matched string */
2798    unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
2799{
2800    s->d_buf[s->last_lit] = (ush)dist;
2801    s->l_buf[s->last_lit++] = (uch)lc;
2802    if (dist == 0) {
2803        /* lc is the unmatched char */
2804        s->dyn_ltree[lc].Freq++;
2805    } else {
2806        s->matches++;
2807        /* Here, lc is the match length - MIN_MATCH */
2808        dist--;             /* dist = match distance - 1 */
2809        Assert((ush)dist < (ush)MAX_DIST(s) &&
2810               (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2811               (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");
2812
2813        s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2814        s->dyn_dtree[d_code(dist)].Freq++;
2815    }
2816
2817    /* Try to guess if it is profitable to stop the current block here */
2818    if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2819        /* Compute an upper bound for the compressed length */
2820        ulg out_length = (ulg)s->last_lit*8L;
2821        ulg in_length = (ulg)((long)s->strstart - s->block_start);
2822        int dcode;
2823        for (dcode = 0; dcode < D_CODES; dcode++) {
2824            out_length += (ulg)s->dyn_dtree[dcode].Freq *
2825                (5L+extra_dbits[dcode]);
2826        }
2827        out_length >>= 3;
2828        Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2829               s->last_lit, in_length, out_length,
2830               100L - out_length*100L/in_length));
2831        if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2832    }
2833    return (s->last_lit == s->lit_bufsize-1);
2834    /* We avoid equality with lit_bufsize because of wraparound at 64K
2835     * on 16 bit machines and because stored blocks are restricted to
2836     * 64K-1 bytes.
2837     */
2838}
2839
2840/* ===========================================================================
2841 * Send the block data compressed using the given Huffman trees
2842 */
2843local void compress_block(s, ltree, dtree)
2844    deflate_state *s;
2845    ct_data *ltree; /* literal tree */
2846    ct_data *dtree; /* distance tree */
2847{
2848    unsigned dist;      /* distance of matched string */
2849    int lc;             /* match length or unmatched char (if dist == 0) */
2850    unsigned lx = 0;    /* running index in l_buf */
2851    unsigned code;      /* the code to send */
2852    int extra;          /* number of extra bits to send */
2853
2854    if (s->last_lit != 0) do {
2855        dist = s->d_buf[lx];
2856        lc = s->l_buf[lx++];
2857        if (dist == 0) {
2858            send_code(s, lc, ltree); /* send a literal byte */
2859            Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2860        } else {
2861            /* Here, lc is the match length - MIN_MATCH */
2862            code = length_code[lc];
2863            send_code(s, code+LITERALS+1, ltree); /* send the length code */
2864            extra = extra_lbits[code];
2865            if (extra != 0) {
2866                lc -= base_length[code];
2867                send_bits(s, lc, extra);       /* send the extra length bits */
2868            }
2869            dist--; /* dist is now the match distance - 1 */
2870            code = d_code(dist);
2871            Assert (code < D_CODES, "bad d_code");
2872
2873            send_code(s, code, dtree);       /* send the distance code */
2874            extra = extra_dbits[code];
2875            if (extra != 0) {
2876                dist -= base_dist[code];
2877                send_bits(s, dist, extra);   /* send the extra distance bits */
2878            }
2879        } /* literal or match pair ? */
2880
2881        /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2882        Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2883
2884    } while (lx < s->last_lit);
2885
2886    send_code(s, END_BLOCK, ltree);
2887    s->last_eob_len = ltree[END_BLOCK].Len;
2888}
2889
2890/* ===========================================================================
2891 * Set the data type to ASCII or BINARY, using a crude approximation:
2892 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2893 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2894 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2895 */
2896local void set_data_type(s)
2897    deflate_state *s;
2898{
2899    int n = 0;
2900    unsigned ascii_freq = 0;
2901    unsigned bin_freq = 0;
2902    while (n < 7)        bin_freq += s->dyn_ltree[n++].Freq;
2903    while (n < 128)    ascii_freq += s->dyn_ltree[n++].Freq;
2904    while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2905    s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
2906}
2907
2908/* ===========================================================================
2909 * Reverse the first len bits of a code, using straightforward code (a faster
2910 * method would use a table)
2911 * IN assertion: 1 <= len <= 15
2912 */
2913local unsigned bi_reverse(code, len)
2914    unsigned code; /* the value to invert */
2915    int len;       /* its bit length */
2916{
2917    register unsigned res = 0;
2918    do {
2919        res |= code & 1;
2920        code >>= 1, res <<= 1;
2921    } while (--len > 0);
2922    return res >> 1;
2923}
2924
2925/* ===========================================================================
2926 * Flush the bit buffer, keeping at most 7 bits in it.
2927 */
2928local void bi_flush(s)
2929    deflate_state *s;
2930{
2931    if (s->bi_valid == 16) {
2932        put_short(s, s->bi_buf);
2933        s->bi_buf = 0;
2934        s->bi_valid = 0;
2935    } else if (s->bi_valid >= 8) {
2936        put_byte(s, (Byte)s->bi_buf);
2937        s->bi_buf >>= 8;
2938        s->bi_valid -= 8;
2939    }
2940}
2941
2942/* ===========================================================================
2943 * Flush the bit buffer and align the output on a byte boundary
2944 */
2945local void bi_windup(s)
2946    deflate_state *s;
2947{
2948    if (s->bi_valid > 8) {
2949        put_short(s, s->bi_buf);
2950    } else if (s->bi_valid > 0) {
2951        put_byte(s, (Byte)s->bi_buf);
2952    }
2953    s->bi_buf = 0;
2954    s->bi_valid = 0;
2955#ifdef DEBUG_ZLIB
2956    s->bits_sent = (s->bits_sent+7) & ~7;
2957#endif
2958}
2959
2960/* ===========================================================================
2961 * Copy a stored block, storing first the length and its
2962 * one's complement if requested.
2963 */
2964local void copy_block(s, buf, len, header)
2965    deflate_state *s;
2966    charf    *buf;    /* the input data */
2967    unsigned len;     /* its length */
2968    int      header;  /* true if block header must be written */
2969{
2970    bi_windup(s);        /* align on byte boundary */
2971    s->last_eob_len = 8; /* enough lookahead for inflate */
2972
2973    if (header) {
2974        put_short(s, (ush)len);   
2975        put_short(s, (ush)~len);
2976#ifdef DEBUG_ZLIB
2977        s->bits_sent += 2*16;
2978#endif
2979    }
2980#ifdef DEBUG_ZLIB
2981    s->bits_sent += (ulg)len<<3;
2982#endif
2983    /* bundle up the put_byte(s, *buf++) calls */
2984    zmemcpy(&s->pending_buf[s->pending], buf, len);
2985    s->pending += len;
2986}
2987/* --- trees.c */
2988
2989/* +++ inflate.c */
2990/* inflate.c -- zlib interface to inflate modules
2991 * Copyright (C) 1995-1996 Mark Adler
2992 * For conditions of distribution and use, see copyright notice in zlib.h
2993 */
2994
2995/* #include "zutil.h" */
2996
2997/* +++ infblock.h */
2998/* infblock.h -- header to use infblock.c
2999 * Copyright (C) 1995-1996 Mark Adler
3000 * For conditions of distribution and use, see copyright notice in zlib.h
3001 */
3002
3003/* WARNING: this file should *not* be used by applications. It is
3004   part of the implementation of the compression library and is
3005   subject to change. Applications should only use zlib.h.
3006 */
3007
3008struct inflate_blocks_state;
3009typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3010
3011extern inflate_blocks_statef * inflate_blocks_new OF((
3012    z_streamp z,
3013    check_func c,               /* check function */
3014    uInt w));                   /* window size */
3015
3016extern int inflate_blocks OF((
3017    inflate_blocks_statef *,
3018    z_streamp ,
3019    int));                      /* initial return code */
3020
3021extern void inflate_blocks_reset OF((
3022    inflate_blocks_statef *,
3023    z_streamp ,
3024    uLongf *));                  /* check value on output */
3025
3026extern int inflate_blocks_free OF((
3027    inflate_blocks_statef *,
3028    z_streamp ,
3029    uLongf *));                  /* check value on output */
3030
3031extern void inflate_set_dictionary OF((
3032    inflate_blocks_statef *s,
3033    const Bytef *d,  /* dictionary */
3034    uInt  n));       /* dictionary length */
3035
3036extern int inflate_addhistory OF((
3037    inflate_blocks_statef *,
3038    z_streamp));
3039
3040extern int inflate_packet_flush OF((
3041    inflate_blocks_statef *));
3042/* --- infblock.h */
3043
3044#ifndef NO_DUMMY_DECL
3045struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3046#endif
3047
3048/* inflate private state */
3049struct internal_state {
3050
3051  /* mode */
3052  enum {
3053      METHOD,   /* waiting for method byte */
3054      FLAG,     /* waiting for flag byte */
3055      DICT4,    /* four dictionary check bytes to go */
3056      DICT3,    /* three dictionary check bytes to go */
3057      DICT2,    /* two dictionary check bytes to go */
3058      DICT1,    /* one dictionary check byte to go */
3059      DICT0,    /* waiting for inflateSetDictionary */
3060      BLOCKS,   /* decompressing blocks */
3061      CHECK4,   /* four check bytes to go */
3062      CHECK3,   /* three check bytes to go */
3063      CHECK2,   /* two check bytes to go */
3064      CHECK1,   /* one check byte to go */
3065      DONE,     /* finished check, done */
3066      BAD}      /* got an error--stay here */
3067    mode;               /* current inflate mode */
3068
3069  /* mode dependent information */
3070  union {
3071    uInt method;        /* if FLAGS, method byte */
3072    struct {
3073      uLong was;                /* computed check value */
3074      uLong need;               /* stream check value */
3075    } check;            /* if CHECK, check values to compare */
3076    uInt marker;        /* if BAD, inflateSync's marker bytes count */
3077  } sub;        /* submode */
3078
3079  /* mode independent information */
3080  int  nowrap;          /* flag for no wrapper */
3081  uInt wbits;           /* log2(window size)  (8..15, defaults to 15) */
3082  inflate_blocks_statef
3083    *blocks;            /* current inflate_blocks state */
3084
3085};
3086
3087
3088int inflateReset(z)
3089z_streamp z;
3090{
3091  uLong c;
3092
3093  if (z == Z_NULL || z->state == Z_NULL)
3094    return Z_STREAM_ERROR;
3095  z->total_in = z->total_out = 0;
3096  z->msg = Z_NULL;
3097  z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3098  inflate_blocks_reset(z->state->blocks, z, &c);
3099  Trace((stderr, "inflate: reset\n"));
3100  return Z_OK;
3101}
3102
3103
3104int inflateEnd(z)
3105z_streamp z;
3106{
3107  uLong c;
3108
3109  if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3110    return Z_STREAM_ERROR;
3111  if (z->state->blocks != Z_NULL)
3112    inflate_blocks_free(z->state->blocks, z, &c);
3113  ZFREE(z, z->state);
3114  z->state = Z_NULL;
3115  Trace((stderr, "inflate: end\n"));
3116  return Z_OK;
3117}
3118
3119
3120int inflateInit2_(z, w, version, stream_size)
3121z_streamp z;
3122int w;
3123const char *version;
3124int stream_size;
3125{
3126  if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3127      stream_size != sizeof(z_stream))
3128      return Z_VERSION_ERROR;
3129
3130  /* initialize state */
3131  if (z == Z_NULL)
3132    return Z_STREAM_ERROR;
3133  z->msg = Z_NULL;
3134#ifndef NO_ZCFUNCS
3135  if (z->zalloc == Z_NULL)
3136  {
3137    z->zalloc = zcalloc;
3138    z->opaque = (voidpf)0;
3139  }
3140  if (z->zfree == Z_NULL) z->zfree = zcfree;
3141#endif
3142  if ((z->state = (struct internal_state FAR *)
3143       ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3144    return Z_MEM_ERROR;
3145  z->state->blocks = Z_NULL;
3146
3147  /* handle undocumented nowrap option (no zlib header or check) */
3148  z->state->nowrap = 0;
3149  if (w < 0)
3150  {
3151    w = - w;
3152    z->state->nowrap = 1;
3153  }
3154
3155  /* set window size */
3156  if (w < 8 || w > 15)
3157  {
3158    inflateEnd(z);
3159    return Z_STREAM_ERROR;
3160  }
3161  z->state->wbits = (uInt)w;
3162
3163  /* create inflate_blocks state */
3164  if ((z->state->blocks =
3165      inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3166      == Z_NULL)
3167  {
3168    inflateEnd(z);
3169    return Z_MEM_ERROR;
3170  }
3171  Trace((stderr, "inflate: allocated\n"));
3172
3173  /* reset state */
3174  inflateReset(z);
3175  return Z_OK;
3176}
3177
3178
3179int inflateInit_(z, version, stream_size)
3180z_streamp z;
3181const char *version;
3182int stream_size;
3183{
3184  return inflateInit2_(z, DEF_WBITS, version, stream_size);
3185}
3186
3187
3188#define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3189#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3190
3191int inflate(z, f)
3192z_streamp z;
3193int f;
3194{
3195  int r;
3196  uInt b;
3197
3198  if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0)
3199    return Z_STREAM_ERROR;
3200  r = Z_BUF_ERROR;
3201  while (1) switch (z->state->mode)
3202  {
3203    case METHOD:
3204      NEEDBYTE
3205      if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3206      {
3207        z->state->mode = BAD;
3208        z->msg = (char*)"unknown compression method";
3209        z->state->sub.marker = 5;       /* can't try inflateSync */
3210        break;
3211      }
3212      if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3213      {
3214        z->state->mode = BAD;
3215        z->msg = (char*)"invalid window size";
3216        z->state->sub.marker = 5;       /* can't try inflateSync */
3217        break;
3218      }
3219      z->state->mode = FLAG;
3220    case FLAG:
3221      NEEDBYTE
3222      b = NEXTBYTE;
3223      if (((z->state->sub.method << 8) + b) % 31)
3224      {
3225        z->state->mode = BAD;
3226        z->msg = (char*)"incorrect header check";
3227        z->state->sub.marker = 5;       /* can't try inflateSync */
3228        break;
3229      }
3230      Trace((stderr, "inflate: zlib header ok\n"));
3231      if (!(b & PRESET_DICT))
3232      {
3233        z->state->mode = BLOCKS;
3234        break;
3235      }
3236      z->state->mode = DICT4;
3237    case DICT4:
3238      NEEDBYTE
3239      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3240      z->state->mode = DICT3;
3241    case DICT3:
3242      NEEDBYTE
3243      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3244      z->state->mode = DICT2;
3245    case DICT2:
3246      NEEDBYTE
3247      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3248      z->state->mode = DICT1;
3249    case DICT1:
3250      NEEDBYTE
3251      z->state->sub.check.need += (uLong)NEXTBYTE;
3252      z->adler = z->state->sub.check.need;
3253      z->state->mode = DICT0;
3254      return Z_NEED_DICT;
3255    case DICT0:
3256      z->state->mode = BAD;
3257      z->msg = (char*)"need dictionary";
3258      z->state->sub.marker = 0;       /* can try inflateSync */
3259      return Z_STREAM_ERROR;
3260    case BLOCKS:
3261      r = inflate_blocks(z->state->blocks, z, r);
3262      if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3263          r = inflate_packet_flush(z->state->blocks);
3264      if (r == Z_DATA_ERROR)
3265      {
3266        z->state->mode = BAD;
3267        z->state->sub.marker = 0;       /* can try inflateSync */
3268        break;
3269      }
3270      if (r != Z_STREAM_END)
3271        return r;
3272      r = Z_OK;
3273      inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3274      if (z->state->nowrap)
3275      {
3276        z->state->mode = DONE;
3277        break;
3278      }
3279      z->state->mode = CHECK4;
3280    case CHECK4:
3281      NEEDBYTE
3282      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3283      z->state->mode = CHECK3;
3284    case CHECK3:
3285      NEEDBYTE
3286      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3287      z->state->mode = CHECK2;
3288    case CHECK2:
3289      NEEDBYTE
3290      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3291      z->state->mode = CHECK1;
3292    case CHECK1:
3293      NEEDBYTE
3294      z->state->sub.check.need += (uLong)NEXTBYTE;
3295
3296      if (z->state->sub.check.was != z->state->sub.check.need)
3297      {
3298        z->state->mode = BAD;
3299        z->msg = (char*)"incorrect data check";
3300        z->state->sub.marker = 5;       /* can't try inflateSync */
3301        break;
3302      }
3303      Trace((stderr, "inflate: zlib check ok\n"));
3304      z->state->mode = DONE;
3305    case DONE:
3306      return Z_STREAM_END;
3307    case BAD:
3308      return Z_DATA_ERROR;
3309    default:
3310      return Z_STREAM_ERROR;
3311  }
3312
3313 empty:
3314  if (f != Z_PACKET_FLUSH)
3315    return r;
3316  z->state->mode = BAD;
3317  z->msg = (char *)"need more for packet flush";
3318  z->state->sub.marker = 0;       /* can try inflateSync */
3319  return Z_DATA_ERROR;
3320}
3321
3322
3323int inflateSetDictionary(z, dictionary, dictLength)
3324z_streamp z;
3325const Bytef *dictionary;
3326uInt  dictLength;
3327{
3328  uInt length = dictLength;
3329
3330  if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3331    return Z_STREAM_ERROR;
3332
3333  if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3334  z->adler = 1L;
3335
3336  if (length >= ((uInt)1<<z->state->wbits))
3337  {
3338    length = (1<<z->state->wbits)-1;
3339    dictionary += dictLength - length;
3340  }
3341  inflate_set_dictionary(z->state->blocks, dictionary, length);
3342  z->state->mode = BLOCKS;
3343  return Z_OK;
3344}
3345
3346/*
3347 * This subroutine adds the data at next_in/avail_in to the output history
3348 * without performing any output.  The output buffer must be "caught up";
3349 * i.e. no pending output (hence s->read equals s->write), and the state must
3350 * be BLOCKS (i.e. we should be willing to see the start of a series of
3351 * BLOCKS).  On exit, the output will also be caught up, and the checksum
3352 * will have been updated if need be.
3353 */
3354
3355int inflateIncomp(z)
3356z_stream *z;
3357{
3358    if (z->state->mode != BLOCKS)
3359        return Z_DATA_ERROR;
3360    return inflate_addhistory(z->state->blocks, z);
3361}
3362
3363
3364int inflateSync(z)
3365z_streamp z;
3366{
3367  uInt n;       /* number of bytes to look at */
3368  Bytef *p;     /* pointer to bytes */
3369  uInt m;       /* number of marker bytes found in a row */
3370  uLong r, w;   /* temporaries to save total_in and total_out */
3371
3372  /* set up */
3373  if (z == Z_NULL || z->state == Z_NULL)
3374    return Z_STREAM_ERROR;
3375  if (z->state->mode != BAD)
3376  {
3377    z->state->mode = BAD;
3378    z->state->sub.marker = 0;
3379  }
3380  if ((n = z->avail_in) == 0)
3381    return Z_BUF_ERROR;
3382  p = z->next_in;
3383  m = z->state->sub.marker;
3384
3385  /* search */
3386  while (n && m < 4)
3387  {
3388    if (*p == (Byte)(m < 2 ? 0 : 0xff))
3389      m++;
3390    else if (*p)
3391      m = 0;
3392    else
3393      m = 4 - m;
3394    p++, n--;
3395  }
3396
3397  /* restore */
3398  z->total_in += p - z->next_in;
3399  z->next_in = p;
3400  z->avail_in = n;
3401  z->state->sub.marker = m;
3402
3403  /* return no joy or set up to restart on a new block */
3404  if (m != 4)
3405    return Z_DATA_ERROR;
3406  r = z->total_in;  w = z->total_out;
3407  inflateReset(z);
3408  z->total_in = r;  z->total_out = w;
3409  z->state->mode = BLOCKS;
3410  return Z_OK;
3411}
3412
3413#undef NEEDBYTE
3414#undef NEXTBYTE
3415/* --- inflate.c */
3416
3417/* +++ infblock.c */
3418/* infblock.c -- interpret and process block types to last block
3419 * Copyright (C) 1995-1996 Mark Adler
3420 * For conditions of distribution and use, see copyright notice in zlib.h
3421 */
3422
3423/* #include "zutil.h" */
3424/* #include "infblock.h" */
3425
3426/* +++ inftrees.h */
3427/* inftrees.h -- header to use inftrees.c
3428 * Copyright (C) 1995-1996 Mark Adler
3429 * For conditions of distribution and use, see copyright notice in zlib.h
3430 */
3431
3432/* WARNING: this file should *not* be used by applications. It is
3433   part of the implementation of the compression library and is
3434   subject to change. Applications should only use zlib.h.
3435 */
3436
3437/* Huffman code lookup table entry--this entry is four bytes for machines
3438   that have 16-bit pointers (e.g. PC's in the small or medium model). */
3439
3440typedef struct inflate_huft_s FAR inflate_huft;
3441
3442struct inflate_huft_s {
3443  union {
3444    struct {
3445      Byte Exop;        /* number of extra bits or operation */
3446      Byte Bits;        /* number of bits in this code or subcode */
3447    } what;
3448    Bytef *pad;         /* pad structure to a power of 2 (4 bytes for */
3449  } word;               /*  16-bit, 8 bytes for 32-bit machines) */
3450  union {
3451    uInt Base;          /* literal, length base, or distance base */
3452    inflate_huft *Next; /* pointer to next level of table */
3453  } more;
3454};
3455
3456#ifdef DEBUG_ZLIB
3457  extern uInt inflate_hufts;
3458#endif
3459
3460extern int inflate_trees_bits OF((
3461    uIntf *,                    /* 19 code lengths */
3462    uIntf *,                    /* bits tree desired/actual depth */
3463    inflate_huft * FAR *,       /* bits tree result */
3464    z_streamp ));               /* for zalloc, zfree functions */
3465
3466extern int inflate_trees_dynamic OF((
3467    uInt,                       /* number of literal/length codes */
3468    uInt,                       /* number of distance codes */
3469    uIntf *,                    /* that many (total) code lengths */
3470    uIntf *,                    /* literal desired/actual bit depth */
3471    uIntf *,                    /* distance desired/actual bit depth */
3472    inflate_huft * FAR *,       /* literal/length tree result */
3473    inflate_huft * FAR *,       /* distance tree result */
3474    z_streamp ));               /* for zalloc, zfree functions */
3475
3476extern int inflate_trees_fixed OF((
3477    uIntf *,                    /* literal desired/actual bit depth */
3478    uIntf *,                    /* distance desired/actual bit depth */
3479    inflate_huft * FAR *,       /* literal/length tree result */
3480    inflate_huft * FAR *));     /* distance tree result */
3481
3482extern int inflate_trees_free OF((
3483    inflate_huft *,             /* tables to free */
3484    z_streamp ));               /* for zfree function */
3485
3486/* --- inftrees.h */
3487
3488/* +++ infcodes.h */
3489/* infcodes.h -- header to use infcodes.c
3490 * Copyright (C) 1995-1996 Mark Adler
3491 * For conditions of distribution and use, see copyright notice in zlib.h
3492 */
3493
3494/* WARNING: this file should *not* be used by applications. It is
3495   part of the implementation of the compression library and is
3496   subject to change. Applications should only use zlib.h.
3497 */
3498
3499struct inflate_codes_state;
3500typedef struct inflate_codes_state FAR inflate_codes_statef;
3501
3502extern inflate_codes_statef *inflate_codes_new OF((
3503    uInt, uInt,
3504    inflate_huft *, inflate_huft *,
3505    z_streamp ));
3506
3507extern int inflate_codes OF((
3508    inflate_blocks_statef *,
3509    z_streamp ,
3510    int));
3511
3512extern void inflate_codes_free OF((
3513    inflate_codes_statef *,
3514    z_streamp ));
3515
3516/* --- infcodes.h */
3517
3518/* +++ infutil.h */
3519/* infutil.h -- types and macros common to blocks and codes
3520 * Copyright (C) 1995-1996 Mark Adler
3521 * For conditions of distribution and use, see copyright notice in zlib.h
3522 */
3523
3524/* WARNING: this file should *not* be used by applications. It is
3525   part of the implementation of the compression library and is
3526   subject to change. Applications should only use zlib.h.
3527 */
3528
3529#ifndef _INFUTIL_H
3530#define _INFUTIL_H
3531
3532typedef enum {
3533      TYPE,     /* get type bits (3, including end bit) */
3534      LENS,     /* get lengths for stored */
3535      STORED,   /* processing stored block */
3536      TABLE,    /* get table lengths */
3537      BTREE,    /* get bit lengths tree for a dynamic block */
3538      DTREE,    /* get length, distance trees for a dynamic block */
3539      CODES,    /* processing fixed or dynamic block */
3540      DRY,      /* output remaining window bytes */
3541      DONEB,    /* finished last block, done */
3542      BADB}     /* got a data error--stuck here */
3543inflate_block_mode;
3544
3545/* inflate blocks semi-private state */
3546struct inflate_blocks_state {
3547
3548  /* mode */
3549  inflate_block_mode  mode;     /* current inflate_block mode */
3550
3551  /* mode dependent information */
3552  union {
3553    uInt left;          /* if STORED, bytes left to copy */
3554    struct {
3555      uInt table;               /* table lengths (14 bits) */
3556      uInt index;               /* index into blens (or border) */
3557      uIntf *blens;             /* bit lengths of codes */
3558      uInt bb;                  /* bit length tree depth */
3559      inflate_huft *tb;         /* bit length decoding tree */
3560    } trees;            /* if DTREE, decoding info for trees */
3561    struct {
3562      inflate_huft *tl;
3563      inflate_huft *td;         /* trees to free */
3564      inflate_codes_statef
3565         *codes;
3566    } decode;           /* if CODES, current state */
3567  } sub;                /* submode */
3568  uInt last;            /* true if this block is the last block */
3569
3570  /* mode independent information */
3571  uInt bitk;            /* bits in bit buffer */
3572  uLong bitb;           /* bit buffer */
3573  Bytef *window;        /* sliding window */
3574  Bytef *end;           /* one byte after sliding window */
3575  Bytef *read;          /* window read pointer */
3576  Bytef *write;         /* window write pointer */
3577  check_func checkfn;   /* check function */
3578  uLong check;          /* check on output */
3579
3580};
3581
3582
3583/* defines for inflate input/output */
3584/*   update pointers and return */
3585#define UPDBITS {s->bitb=b;s->bitk=k;}
3586#define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3587#define UPDOUT {s->write=q;}
3588#define UPDATE {UPDBITS UPDIN UPDOUT}
3589#define LEAVE {UPDATE return inflate_flush(s,z,r);}
3590/*   get bytes and bits */
3591#define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3592#define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3593#define NEXTBYTE (n--,*p++)
3594#define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3595#define DUMPBITS(j) {b>>=(j);k-=(j);}
3596/*   output bytes */
3597#define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3598#define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3599#define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3600#define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3601#define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;}
3602#define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3603/*   load local pointers */
3604#define LOAD {LOADIN LOADOUT}
3605
3606/* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3607extern uInt inflate_mask[17];
3608
3609/* copy as much as possible from the sliding window to the output area */
3610extern int inflate_flush OF((
3611    inflate_blocks_statef *,
3612    z_streamp ,
3613    int));
3614
3615#ifndef NO_DUMMY_DECL
3616struct internal_state      {int dummy;}; /* for buggy compilers */
3617#endif
3618
3619#endif
3620/* --- infutil.h */
3621
3622#ifndef NO_DUMMY_DECL
3623struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3624#endif
3625
3626/* Table for deflate from PKZIP's appnote.txt. */
3627local const uInt border[] = { /* Order of the bit length code lengths */
3628        16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3629
3630/*
3631   Notes beyond the 1.93a appnote.txt:
3632
3633   1. Distance pointers never point before the beginning of the output
3634      stream.
3635   2. Distance pointers can point back across blocks, up to 32k away.
3636   3. There is an implied maximum of 7 bits for the bit length table and
3637      15 bits for the actual data.
3638   4. If only one code exists, then it is encoded using one bit.  (Zero
3639      would be more efficient, but perhaps a little confusing.)  If two
3640      codes exist, they are coded using one bit each (0 and 1).
3641   5. There is no way of sending zero distance codes--a dummy must be
3642      sent if there are none.  (History: a pre 2.0 version of PKZIP would
3643      store blocks with no distance codes, but this was discovered to be
3644      too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow
3645      zero distance codes, which is sent as one code of zero bits in
3646      length.
3647   6. There are up to 286 literal/length codes.  Code 256 represents the
3648      end-of-block.  Note however that the static length tree defines
3649      288 codes just to fill out the Huffman codes.  Codes 286 and 287
3650      cannot be used though, since there is no length base or extra bits
3651      defined for them.  Similarily, there are up to 30 distance codes.
3652      However, static trees define 32 codes (all 5 bits) to fill out the
3653      Huffman codes, but the last two had better not show up in the data.
3654   7. Unzip can check dynamic Huffman blocks for complete code sets.
3655      The exception is that a single code would not be complete (see #4).
3656   8. The five bits following the block type is really the number of
3657      literal codes sent minus 257.
3658   9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3659      (1+6+6).  Therefore, to output three times the length, you output
3660      three codes (1+1+1), whereas to output four times the same length,
3661      you only need two codes (1+3).  Hmm.
3662  10. In the tree reconstruction algorithm, Code = Code + Increment
3663      only if BitLength(i) is not zero.  (Pretty obvious.)
3664  11. Correction: 4 Bits: # of Bit Length codes - 4     (4 - 19)
3665  12. Note: length code 284 can represent 227-258, but length code 285
3666      really is 258.  The last length deserves its own, short code
3667      since it gets used a lot in very redundant files.  The length
3668      258 is special since 258 - 3 (the min match length) is 255.
3669  13. The literal/length and distance code bit lengths are read as a
3670      single stream of lengths.  It is possible (and advantageous) for
3671      a repeat code (16, 17, or 18) to go across the boundary between
3672      the two sets of lengths.
3673 */
3674
3675
3676void inflate_blocks_reset(s, z, c)
3677inflate_blocks_statef *s;
3678z_streamp z;
3679uLongf *c;
3680{
3681  if (s->checkfn != Z_NULL)
3682    *c = s->check;
3683  if (s->mode == BTREE || s->mode == DTREE)
3684    ZFREE(z, s->sub.trees.blens);
3685  if (s->mode == CODES)
3686  {
3687    inflate_codes_free(s->sub.decode.codes, z);
3688    inflate_trees_free(s->sub.decode.td, z);
3689    inflate_trees_free(s->sub.decode.tl, z);
3690  }
3691  s->mode = TYPE;
3692  s->bitk = 0;
3693  s->bitb = 0;
3694  s->read = s->write = s->window;
3695  if (s->checkfn != Z_NULL)
3696    z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
3697  Trace((stderr, "inflate:   blocks reset\n"));
3698}
3699
3700
3701inflate_blocks_statef *inflate_blocks_new(z, c, w)
3702z_streamp z;
3703check_func c;
3704uInt w;
3705{
3706  inflate_blocks_statef *s;
3707
3708  if ((s = (inflate_blocks_statef *)ZALLOC
3709       (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3710    return s;
3711  if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3712  {
3713    ZFREE(z, s);
3714    return Z_NULL;
3715  }
3716  s->end = s->window + w;
3717  s->checkfn = c;
3718  s->mode = TYPE;
3719  Trace((stderr, "inflate:   blocks allocated\n"));
3720  inflate_blocks_reset(s, z, &s->check);
3721  return s;
3722}
3723
3724
3725#ifdef DEBUG_ZLIB
3726  extern uInt inflate_hufts;
3727#endif
3728int inflate_blocks(s, z, r)
3729inflate_blocks_statef *s;
3730z_streamp z;
3731int r;
3732{
3733  uInt t;               /* temporary storage */
3734  uLong b;              /* bit buffer */
3735  uInt k;               /* bits in bit buffer */
3736  Bytef *p;             /* input data pointer */
3737  uInt n;               /* bytes available there */
3738  Bytef *q;             /* output window write pointer */
3739  uInt m;               /* bytes to end of window or read pointer */
3740
3741  /* copy input/output information to locals (UPDATE macro restores) */
3742  LOAD
3743
3744  /* process input based on current state */
3745  while (1) switch (s->mode)
3746  {
3747    case TYPE:
3748      NEEDBITS(3)
3749      t = (uInt)b & 7;
3750      s->last = t & 1;
3751      switch (t >> 1)
3752      {
3753        case 0:                         /* stored */
3754          Trace((stderr, "inflate:     stored block%s\n",
3755                 s->last ? " (last)" : ""));
3756          DUMPBITS(3)
3757          t = k & 7;                    /* go to byte boundary */
3758          DUMPBITS(t)
3759          s->mode = LENS;               /* get length of stored block */
3760          break;
3761        case 1:                         /* fixed */
3762          Trace((stderr, "inflate:     fixed codes block%s\n",
3763                 s->last ? " (last)" : ""));
3764          {
3765            uInt bl, bd;
3766            inflate_huft *tl, *td;
3767
3768            inflate_trees_fixed(&bl, &bd, &tl, &td);
3769            s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3770            if (s->sub.decode.codes == Z_NULL)
3771            {
3772              r = Z_MEM_ERROR;
3773              LEAVE
3774            }
3775            s->sub.decode.tl = Z_NULL;  /* don't try to free these */
3776            s->sub.decode.td = Z_NULL;
3777          }
3778          DUMPBITS(3)
3779          s->mode = CODES;
3780          break;
3781        case 2:                         /* dynamic */
3782          Trace((stderr, "inflate:     dynamic codes block%s\n",
3783                 s->last ? " (last)" : ""));
3784          DUMPBITS(3)
3785          s->mode = TABLE;
3786          break;
3787        case 3:                         /* illegal */
3788          DUMPBITS(3)
3789          s->mode = BADB;
3790          z->msg = (char*)"invalid block type";
3791          r = Z_DATA_ERROR;
3792          LEAVE
3793      }
3794      break;
3795    case LENS:
3796      NEEDBITS(32)
3797      if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
3798      {
3799        s->mode = BADB;
3800        z->msg = (char*)"invalid stored block lengths";
3801        r = Z_DATA_ERROR;
3802        LEAVE
3803      }
3804      s->sub.left = (uInt)b & 0xffff;
3805      b = k = 0;                      /* dump bits */
3806      Tracev((stderr, "inflate:       stored length %u\n", s->sub.left));
3807      s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
3808      break;
3809    case STORED:
3810      if (n == 0)
3811        LEAVE
3812      NEEDOUT
3813      t = s->sub.left;
3814      if (t > n) t = n;
3815      if (t > m) t = m;
3816      zmemcpy(q, p, t);
3817      p += t;  n -= t;
3818      q += t;  m -= t;
3819      if ((s->sub.left -= t) != 0)
3820        break;
3821      Tracev((stderr, "inflate:       stored end, %lu total out\n",
3822              z->total_out + (q >= s->read ? q - s->read :
3823              (s->end - s->read) + (q - s->window))));
3824      s->mode = s->last ? DRY : TYPE;
3825      break;
3826    case TABLE:
3827      NEEDBITS(14)
3828      s->sub.trees.table = t = (uInt)b & 0x3fff;
3829#ifndef PKZIP_BUG_WORKAROUND
3830      if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3831      {
3832        s->mode = BADB;
3833        z->msg = (char*)"too many length or distance symbols";
3834        r = Z_DATA_ERROR;
3835        LEAVE
3836      }
3837#endif
3838      t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3839      if (t < 19)
3840        t = 19;
3841      if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3842      {
3843        r = Z_MEM_ERROR;
3844        LEAVE
3845      }
3846      DUMPBITS(14)
3847      s->sub.trees.index = 0;
3848      Tracev((stderr, "inflate:       table sizes ok\n"));
3849      s->mode = BTREE;
3850    case BTREE:
3851      while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3852      {
3853        NEEDBITS(3)
3854        s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3855        DUMPBITS(3)
3856      }
3857      while (s->sub.trees.index < 19)
3858        s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3859      s->sub.trees.bb = 7;
3860      t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3861                             &s->sub.trees.tb, z);
3862      if (t != Z_OK)
3863      {
3864        ZFREE(z, s->sub.trees.blens);
3865        r = t;
3866        if (r == Z_DATA_ERROR)
3867          s->mode = BADB;
3868        LEAVE
3869      }
3870      s->sub.trees.index = 0;
3871      Tracev((stderr, "inflate:       bits tree ok\n"));
3872      s->mode = DTREE;
3873    case DTREE:
3874      while (t = s->sub.trees.table,
3875             s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3876      {
3877        inflate_huft *h;
3878        uInt i, j, c;
3879
3880        t = s->sub.trees.bb;
3881        NEEDBITS(t)
3882        h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3883        t = h->word.what.Bits;
3884        c = h->more.Base;
3885        if (c < 16)
3886        {
3887          DUMPBITS(t)
3888          s->sub.trees.blens[s->sub.trees.index++] = c;
3889        }
3890        else /* c == 16..18 */
3891        {
3892          i = c == 18 ? 7 : c - 14;
3893          j = c == 18 ? 11 : 3;
3894          NEEDBITS(t + i)
3895          DUMPBITS(t)
3896          j += (uInt)b & inflate_mask[i];
3897          DUMPBITS(i)
3898          i = s->sub.trees.index;
3899          t = s->sub.trees.table;
3900          if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3901              (c == 16 && i < 1))
3902          {
3903            inflate_trees_free(s->sub.trees.tb, z);
3904            ZFREE(z, s->sub.trees.blens);
3905            s->mode = BADB;
3906            z->msg = (char*)"invalid bit length repeat";
3907            r = Z_DATA_ERROR;
3908            LEAVE
3909          }
3910          c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3911          do {
3912            s->sub.trees.blens[i++] = c;
3913          } while (--j);
3914          s->sub.trees.index = i;
3915        }
3916      }
3917      inflate_trees_free(s->sub.trees.tb, z);
3918      s->sub.trees.tb = Z_NULL;
3919      {
3920        uInt bl, bd;
3921        inflate_huft *tl, *td;
3922        inflate_codes_statef *c;
3923
3924        bl = 9;         /* must be <= 9 for lookahead assumptions */
3925        bd = 6;         /* must be <= 9 for lookahead assumptions */
3926        t = s->sub.trees.table;
3927#ifdef DEBUG_ZLIB
3928      inflate_hufts = 0;
3929#endif
3930        t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3931                                  s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3932        ZFREE(z, s->sub.trees.blens);
3933        if (t != Z_OK)
3934        {
3935          if (t == (uInt)Z_DATA_ERROR)
3936            s->mode = BADB;
3937          r = t;
3938          LEAVE
3939        }
3940        Tracev((stderr, "inflate:       trees ok, %d * %d bytes used\n",
3941              inflate_hufts, sizeof(inflate_huft)));
3942        if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3943        {
3944          inflate_trees_free(td, z);
3945          inflate_trees_free(tl, z);
3946          r = Z_MEM_ERROR;
3947          LEAVE
3948        }
3949        s->sub.decode.codes = c;
3950        s->sub.decode.tl = tl;
3951        s->sub.decode.td = td;
3952      }
3953      s->mode = CODES;
3954    case CODES:
3955      UPDATE
3956      if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3957        return inflate_flush(s, z, r);
3958      r = Z_OK;
3959      inflate_codes_free(s->sub.decode.codes, z);
3960      inflate_trees_free(s->sub.decode.td, z);
3961      inflate_trees_free(s->sub.decode.tl, z);
3962      LOAD
3963      Tracev((stderr, "inflate:       codes end, %lu total out\n",
3964              z->total_out + (q >= s->read ? q - s->read :
3965              (s->end - s->read) + (q - s->window))));
3966      if (!s->last)
3967      {
3968        s->mode = TYPE;
3969        break;
3970      }
3971      if (k > 7)              /* return unused byte, if any */
3972      {
3973        Assert(k < 16, "inflate_codes grabbed too many bytes")
3974        k -= 8;
3975        n++;
3976        p--;                    /* can always return one */
3977      }
3978      s->mode = DRY;
3979    case DRY:
3980      FLUSH
3981      if (s->read != s->write)
3982        LEAVE
3983      s->mode = DONEB;
3984    case DONEB:
3985      r = Z_STREAM_END;
3986      LEAVE
3987    case BADB:
3988      r = Z_DATA_ERROR;
3989      LEAVE
3990    default:
3991      r = Z_STREAM_ERROR;
3992      LEAVE
3993  }
3994}
3995
3996
3997int inflate_blocks_free(s, z, c)
3998inflate_blocks_statef *s;
3999z_streamp z;
4000uLongf *c;
4001{
4002  inflate_blocks_reset(s, z, c);
4003  ZFREE(z, s->window);
4004  ZFREE(z, s);
4005  Trace((stderr, "inflate:   blocks freed\n"));
4006  return Z_OK;
4007}
4008
4009
4010void inflate_set_dictionary(s, d, n)
4011inflate_blocks_statef *s;
4012const Bytef *d;
4013uInt  n;
4014{
4015  zmemcpy((charf *)s->window, d, n);
4016  s->read = s->write = s->window + n;
4017}
4018
4019/*
4020 * This subroutine adds the data at next_in/avail_in to the output history
4021 * without performing any output.  The output buffer must be "caught up";
4022 * i.e. no pending output (hence s->read equals s->write), and the state must
4023 * be BLOCKS (i.e. we should be willing to see the start of a series of
4024 * BLOCKS).  On exit, the output will also be caught up, and the checksum
4025 * will have been updated if need be.
4026 */
4027int inflate_addhistory(s, z)
4028inflate_blocks_statef *s;
4029z_stream *z;
4030{
4031    uLong b;              /* bit buffer */  /* NOT USED HERE */
4032    uInt k;               /* bits in bit buffer */ /* NOT USED HERE */
4033    uInt t;               /* temporary storage */
4034    Bytef *p;             /* input data pointer */
4035    uInt n;               /* bytes available there */
4036    Bytef *q;             /* output window write pointer */
4037    uInt m;               /* bytes to end of window or read pointer */
4038
4039    if (s->read != s->write)
4040        return Z_STREAM_ERROR;
4041    if (s->mode != TYPE)
4042        return Z_DATA_ERROR;
4043
4044    /* we're ready to rock */
4045    LOAD
4046    /* while there is input ready, copy to output buffer, moving
4047     * pointers as needed.
4048     */
4049    while (n) {
4050        t = n;  /* how many to do */
4051        /* is there room until end of buffer? */
4052        if (t > m) t = m;
4053        /* update check information */
4054        if (s->checkfn != Z_NULL)
4055            s->check = (*s->checkfn)(s->check, q, t);
4056        zmemcpy(q, p, t);
4057        q += t;
4058        p += t;
4059        n -= t;
4060        z->total_out += t;
4061        s->read = q;    /* drag read pointer forward */
4062/*      WWRAP  */       /* expand WWRAP macro by hand to handle s->read */
4063        if (q == s->end) {
4064            s->read = q = s->window;
4065            m = WAVAIL;
4066        }
4067    }
4068    UPDATE
4069    return Z_OK;
4070}
4071
4072
4073/*
4074 * At the end of a Deflate-compressed PPP packet, we expect to have seen
4075 * a `stored' block type value but not the (zero) length bytes.
4076 */
4077int inflate_packet_flush(s)
4078    inflate_blocks_statef *s;
4079{
4080    if (s->mode != LENS)
4081        return Z_DATA_ERROR;
4082    s->mode = TYPE;
4083    return Z_OK;
4084}
4085/* --- infblock.c */
4086
4087/* +++ inftrees.c */
4088/* inftrees.c -- generate Huffman trees for efficient decoding
4089 * Copyright (C) 1995-1996 Mark Adler
4090 * For conditions of distribution and use, see copyright notice in zlib.h
4091 */
4092
4093/* #include "zutil.h" */
4094/* #include "inftrees.h" */
4095
4096char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler ";
4097/*
4098  If you use the zlib library in a product, an acknowledgment is welcome
4099  in the documentation of your product. If for some reason you cannot
4100  include such an acknowledgment, I would appreciate that you keep this
4101  copyright string in the executable of your product.
4102 */
4103
4104#ifndef NO_DUMMY_DECL
4105struct internal_state  {int dummy;}; /* for buggy compilers */
4106#endif
4107
4108/* simplify the use of the inflate_huft type with some defines */
4109#define base more.Base
4110#define next more.Next
4111#define exop word.what.Exop
4112#define bits word.what.Bits
4113
4114
4115local int huft_build OF((
4116    uIntf *,            /* code lengths in bits */
4117    uInt,               /* number of codes */
4118    uInt,               /* number of "simple" codes */
4119    const uIntf *,      /* list of base values for non-simple codes */
4120    const uIntf *,      /* list of extra bits for non-simple codes */
4121    inflate_huft * FAR*,/* result: starting table */
4122    uIntf *,            /* maximum lookup bits (returns actual) */
4123    z_streamp ));       /* for zalloc function */
4124
4125local voidpf falloc OF((
4126    voidpf,             /* opaque pointer (not used) */
4127    uInt,               /* number of items */
4128    uInt));             /* size of item */
4129
4130/* Tables for deflate from PKZIP's appnote.txt. */
4131local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4132        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4133        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4134        /* see note #13 above about 258 */
4135local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4136        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4137        3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4138local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4139        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4140        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4141        8193, 12289, 16385, 24577};
4142local const uInt cpdext[30] = { /* Extra bits for distance codes */
4143        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4144        7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4145        12, 12, 13, 13};
4146
4147/*
4148   Huffman code decoding is performed using a multi-level table lookup.
4149   The fastest way to decode is to simply build a lookup table whose
4150   size is determined by the longest code.  However, the time it takes
4151   to build this table can also be a factor if the data being decoded
4152   is not very long.  The most common codes are necessarily the
4153   shortest codes, so those codes dominate the decoding time, and hence
4154   the speed.  The idea is you can have a shorter table that decodes the
4155   shorter, more probable codes, and then point to subsidiary tables for
4156   the longer codes.  The time it costs to decode the longer codes is
4157   then traded against the time it takes to make longer tables.
4158
4159   This results of this trade are in the variables lbits and dbits
4160   below.  lbits is the number of bits the first level table for literal/
4161   length codes can decode in one step, and dbits is the same thing for
4162   the distance codes.  Subsequent tables are also less than or equal to
4163   those sizes.  These values may be adjusted either when all of the
4164   codes are shorter than that, in which case the longest code length in
4165   bits is used, or when the shortest code is *longer* than the requested
4166   table size, in which case the length of the shortest code in bits is
4167   used.
4168
4169   There are two different values for the two tables, since they code a
4170   different number of possibilities each.  The literal/length table
4171   codes 286 possible values, or in a flat code, a little over eight
4172   bits.  The distance table codes 30 possible values, or a little less
4173   than five bits, flat.  The optimum values for speed end up being
4174   about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4175   The optimum values may differ though from machine to machine, and
4176   possibly even between compilers.  Your mileage may vary.
4177 */
4178
4179
4180/* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4181#define BMAX 15         /* maximum bit length of any code */
4182#define N_MAX 288       /* maximum number of codes in any set */
4183
4184#ifdef DEBUG_ZLIB
4185  uInt inflate_hufts;
4186#endif
4187
4188local int huft_build(b, n, s, d, e, t, m, zs)
4189uIntf *b;               /* code lengths in bits (all assumed <= BMAX) */
4190uInt n;                 /* number of codes (assumed <= N_MAX) */
4191uInt s;                 /* number of simple-valued codes (0..s-1) */
4192const uIntf *d;         /* list of base values for non-simple codes */
4193const uIntf *e;         /* list of extra bits for non-simple codes */
4194inflate_huft * FAR *t;  /* result: starting table */
4195uIntf *m;               /* maximum lookup bits, returns actual */
4196z_streamp zs;           /* for zalloc function */
4197/* Given a list of code lengths and a maximum table size, make a set of
4198   tables to decode that set of codes.  Return Z_OK on success, Z_BUF_ERROR
4199   if the given code set is incomplete (the tables are still built in this
4200   case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of
4201   lengths), or Z_MEM_ERROR if not enough memory. */
4202{
4203
4204  uInt a;                       /* counter for codes of length k */
4205  uInt c[BMAX+1];               /* bit length count table */
4206  uInt f;                       /* i repeats in table every f entries */
4207  int g;                        /* maximum code length */
4208  int h;                        /* table level */
4209  register uInt i;              /* counter, current code */
4210  register uInt j;              /* counter */
4211  register int k;               /* number of bits in current code */
4212  int l;                        /* bits per table (returned in m) */
4213  register uIntf *p;            /* pointer into c[], b[], or v[] */
4214  inflate_huft *q;              /* points to current table */
4215  struct inflate_huft_s r;      /* table entry for structure assignment */
4216  inflate_huft *u[BMAX];        /* table stack */
4217  uInt v[N_MAX];                /* values in order of bit length */
4218  register int w;               /* bits before this table == (l * h) */
4219  uInt x[BMAX+1];               /* bit offsets, then code stack */
4220  uIntf *xp;                    /* pointer into x */
4221  int y;                        /* number of dummy codes added */
4222  uInt z;                       /* number of entries in current table */
4223
4224
4225  /* Generate counts for each bit length */
4226  p = c;
4227#define C0 *p++ = 0;
4228#define C2 C0 C0 C0 C0
4229#define C4 C2 C2 C2 C2
4230  C4                            /* clear c[]--assume BMAX+1 is 16 */
4231  p = b;  i = n;
4232  do {
4233    c[*p++]++;                  /* assume all entries <= BMAX */
4234  } while (--i);
4235  if (c[0] == n)                /* null input--all zero length codes */
4236  {
4237    *t = (inflate_huft *)Z_NULL;
4238    *m = 0;
4239    return Z_OK;
4240  }
4241
4242
4243  /* Find minimum and maximum length, bound *m by those */
4244  l = *m;
4245  for (j = 1; j <= BMAX; j++)
4246    if (c[j])
4247      break;
4248  k = j;                        /* minimum code length */
4249  if ((uInt)l < j)
4250    l = j;
4251  for (i = BMAX; i; i--)
4252    if (c[i])
4253      break;
4254  g = i;                        /* maximum code length */
4255  if ((uInt)l > i)
4256    l = i;
4257  *m = l;
4258
4259
4260  /* Adjust last length count to fill out codes, if needed */
4261  for (y = 1 << j; j < i; j++, y <<= 1)
4262    if ((y -= c[j]) < 0)
4263      return Z_DATA_ERROR;
4264  if ((y -= c[i]) < 0)
4265    return Z_DATA_ERROR;
4266  c[i] += y;
4267
4268
4269  /* Generate starting offsets into the value table for each length */
4270  x[1] = j = 0;
4271  p = c + 1;  xp = x + 2;
4272  while (--i) {                 /* note that i == g from above */
4273    *xp++ = (j += *p++);
4274  }
4275
4276
4277  /* Make a table of values in order of bit lengths */
4278  p = b;  i = 0;
4279  do {
4280    if ((j = *p++) != 0)
4281      v[x[j]++] = i;
4282  } while (++i < n);
4283  n = x[g];                   /* set n to length of v */
4284
4285
4286  /* Generate the Huffman codes and for each, make the table entries */
4287  x[0] = i = 0;                 /* first Huffman code is zero */
4288  p = v;                        /* grab values in bit order */
4289  h = -1;                       /* no tables yet--level -1 */
4290  w = -l;                       /* bits decoded == (l * h) */
4291  u[0] = (inflate_huft *)Z_NULL;        /* just to keep compilers happy */
4292  q = (inflate_huft *)Z_NULL;   /* ditto */
4293  z = 0;                        /* ditto */
4294
4295  /* go through the bit lengths (k already is bits in shortest code) */
4296  for (; k <= g; k++)
4297  {
4298    a = c[k];
4299    while (a--)
4300    {
4301      /* here i is the Huffman code of length k bits for value *p */
4302      /* make tables up to required level */
4303      while (k > w + l)
4304      {
4305        h++;
4306        w += l;                 /* previous table always l bits */
4307
4308        /* compute minimum size table less than or equal to l bits */
4309        z = g - w;
4310        z = z > (uInt)l ? l : z;        /* table size upper limit */
4311        if ((f = 1 << (j = k - w)) > a + 1)     /* try a k-w bit table */
4312        {                       /* too few codes for k-w bit table */
4313          f -= a + 1;           /* deduct codes from patterns left */
4314          xp = c + k;
4315          if (j < z)
4316            while (++j < z)     /* try smaller tables up to z bits */
4317            {
4318              if ((f <<= 1) <= *++xp)
4319                break;          /* enough codes to use up j bits */
4320              f -= *xp;         /* else deduct codes from patterns */
4321            }
4322        }
4323        z = 1 << j;             /* table entries for j-bit table */
4324
4325        /* allocate and link in new table */
4326        if ((q = (inflate_huft *)ZALLOC
4327             (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
4328        {
4329          if (h)
4330            inflate_trees_free(u[0], zs);
4331          return Z_MEM_ERROR;   /* not enough memory */
4332        }
4333#ifdef DEBUG_ZLIB
4334        inflate_hufts += z + 1;
4335#endif
4336        *t = q + 1;             /* link to list for huft_free() */
4337        *(t = &(q->next)) = Z_NULL;
4338        u[h] = ++q;             /* table starts after link */
4339
4340        /* connect to last table, if there is one */
4341        if (h)
4342        {
4343          x[h] = i;             /* save pattern for backing up */
4344          r.bits = (Byte)l;     /* bits to dump before this table */
4345          r.exop = (Byte)j;     /* bits in this table */
4346          r.next = q;           /* pointer to this table */
4347          j = i >> (w - l);     /* (get around Turbo C bug) */
4348          u[h-1][j] = r;        /* connect to last table */
4349        }
4350      }
4351
4352      /* set up table entry in r */
4353      r.bits = (Byte)(k - w);
4354      if (p >= v + n)
4355        r.exop = 128 + 64;      /* out of values--invalid code */
4356      else if (*p < s)
4357      {
4358        r.exop = (Byte)(*p < 256 ? 0 : 32 + 64);     /* 256 is end-of-block */
4359        r.base = *p++;          /* simple code is just the value */
4360      }
4361      else
4362      {
4363        r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4364        r.base = d[*p++ - s];
4365      }
4366
4367      /* fill code-like entries with r */
4368      f = 1 << (k - w);
4369      for (j = i >> w; j < z; j += f)
4370        q[j] = r;
4371
4372      /* backwards increment the k-bit code i */
4373      for (j = 1 << (k - 1); i & j; j >>= 1)
4374        i ^= j;
4375      i ^= j;
4376
4377      /* backup over finished tables */
4378      while ((i & ((1 << w) - 1)) != x[h])
4379      {
4380        h--;                    /* don't need to update q */
4381        w -= l;
4382      }
4383    }
4384  }
4385
4386
4387  /* Return Z_BUF_ERROR if we were given an incomplete table */
4388  return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4389}
4390
4391
4392int inflate_trees_bits(c, bb, tb, z)
4393uIntf *c;               /* 19 code lengths */
4394uIntf *bb;              /* bits tree desired/actual depth */
4395inflate_huft * FAR *tb; /* bits tree result */
4396z_streamp z;            /* for zfree function */
4397{
4398  int r;
4399
4400  r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
4401  if (r == Z_DATA_ERROR)
4402    z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4403  else if (r == Z_BUF_ERROR || *bb == 0)
4404  {
4405    inflate_trees_free(*tb, z);
4406    z->msg = (char*)"incomplete dynamic bit lengths tree";
4407    r = Z_DATA_ERROR;
4408  }
4409  return r;
4410}
4411
4412
4413int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
4414uInt nl;                /* number of literal/length codes */
4415uInt nd;                /* number of distance codes */
4416uIntf *c;               /* that many (total) code lengths */
4417uIntf *bl;              /* literal desired/actual bit depth */
4418uIntf *bd;              /* distance desired/actual bit depth */
4419inflate_huft * FAR *tl; /* literal/length tree result */
4420inflate_huft * FAR *td; /* distance tree result */
4421z_streamp z;            /* for zfree function */
4422{
4423  int r;
4424
4425  /* build literal/length tree */
4426  r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z);
4427  if (r != Z_OK || *bl == 0)
4428  {
4429    if (r == Z_DATA_ERROR)
4430      z->msg = (char*)"oversubscribed literal/length tree";
4431    else if (r != Z_MEM_ERROR)
4432    {
4433      inflate_trees_free(*tl, z);
4434      z->msg = (char*)"incomplete literal/length tree";
4435      r = Z_DATA_ERROR;
4436    }
4437    return r;
4438  }
4439
4440  /* build distance tree */
4441  r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z);
4442  if (r != Z_OK || (*bd == 0 && nl > 257))
4443  {
4444    if (r == Z_DATA_ERROR)
4445      z->msg = (char*)"oversubscribed distance tree";
4446    else if (r == Z_BUF_ERROR) {
4447#ifdef PKZIP_BUG_WORKAROUND
4448      r = Z_OK;
4449    }
4450#else
4451      inflate_trees_free(*td, z);
4452      z->msg = (char*)"incomplete distance tree";
4453      r = Z_DATA_ERROR;
4454    }
4455    else if (r != Z_MEM_ERROR)
4456    {
4457      z->msg = (char*)"empty distance tree with lengths";
4458      r = Z_DATA_ERROR;
4459    }
4460    inflate_trees_free(*tl, z);
4461    return r;
4462#endif
4463  }
4464
4465  /* done */
4466  return Z_OK;
4467}
4468
4469
4470/* build fixed tables only once--keep them here */
4471local int fixed_built = 0;
4472#define FIXEDH 530      /* number of hufts used by fixed tables */
4473local inflate_huft fixed_mem[FIXEDH];
4474local uInt fixed_bl;
4475local uInt fixed_bd;
4476local inflate_huft *fixed_tl;
4477local inflate_huft *fixed_td;
4478
4479
4480local voidpf falloc(q, n, s)
4481voidpf q;       /* opaque pointer */
4482uInt n;         /* number of items */
4483uInt s;         /* size of item */
4484{
4485  Assert(s == sizeof(inflate_huft) && n <= *(intf *)q,
4486         "inflate_trees falloc overflow");
4487  *(intf *)q -= n+s-s; /* s-s to avoid warning */
4488  return (voidpf)(fixed_mem + *(intf *)q);
4489}
4490
4491
4492int inflate_trees_fixed(bl, bd, tl, td)
4493uIntf *bl;               /* literal desired/actual bit depth */
4494uIntf *bd;               /* distance desired/actual bit depth */
4495inflate_huft * FAR *tl;  /* literal/length tree result */
4496inflate_huft * FAR *td;  /* distance tree result */
4497{
4498  /* build fixed tables if not already (multiple overlapped executions ok) */
4499  if (!fixed_built)
4500  {
4501    int k;              /* temporary variable */
4502    unsigned c[288];    /* length list for huft_build */
4503    z_stream z;         /* for falloc function */
4504    int f = FIXEDH;     /* number of hufts left in fixed_mem */
4505
4506    /* set up fake z_stream for memory routines */
4507    z.zalloc = falloc;
4508    z.zfree = Z_NULL;
4509    z.opaque = (voidpf)&f;
4510
4511    /* literal table */
4512    for (k = 0; k < 144; k++)
4513      c[k] = 8;
4514    for (; k < 256; k++)
4515      c[k] = 9;
4516    for (; k < 280; k++)
4517      c[k] = 7;
4518    for (; k < 288; k++)
4519      c[k] = 8;
4520    fixed_bl = 7;
4521    huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4522
4523    /* distance table */
4524    for (k = 0; k < 30; k++)
4525      c[k] = 5;
4526    fixed_bd = 5;
4527    huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4528
4529    /* done */
4530    Assert(f == 0, "invalid build of fixed tables");
4531    fixed_built = 1;
4532  }
4533  *bl = fixed_bl;
4534  *bd = fixed_bd;
4535  *tl = fixed_tl;
4536  *td = fixed_td;
4537  return Z_OK;
4538}
4539
4540
4541int inflate_trees_free(t, z)
4542inflate_huft *t;        /* table to free */
4543z_streamp z;            /* for zfree function */
4544/* Free the malloc'ed tables built by huft_build(), which makes a linked
4545   list of the tables it made, with the links in a dummy first entry of
4546   each table. */
4547{
4548  register inflate_huft *p, *q, *r;
4549
4550  /* Reverse linked list */
4551  p = Z_NULL;
4552  q = t;
4553  while (q != Z_NULL)
4554  {
4555    r = (q - 1)->next;
4556    (q - 1)->next = p;
4557    p = q;
4558    q = r;
4559  }
4560  /* Go through linked list, freeing from the malloced (t[-1]) address. */
4561  while (p != Z_NULL)
4562  {
4563    q = (--p)->next;
4564    ZFREE(z,p);
4565    p = q;
4566  }
4567  return Z_OK;
4568}
4569/* --- inftrees.c */
4570
4571/* +++ infcodes.c */
4572/* infcodes.c -- process literals and length/distance pairs
4573 * Copyright (C) 1995-1996 Mark Adler
4574 * For conditions of distribution and use, see copyright notice in zlib.h
4575 */
4576
4577/* #include "zutil.h" */
4578/* #include "inftrees.h" */
4579/* #include "infblock.h" */
4580/* #include "infcodes.h" */
4581/* #include "infutil.h" */
4582
4583/* +++ inffast.h */
4584/* inffast.h -- header to use inffast.c
4585 * Copyright (C) 1995-1996 Mark Adler
4586 * For conditions of distribution and use, see copyright notice in zlib.h
4587 */
4588
4589/* WARNING: this file should *not* be used by applications. It is
4590   part of the implementation of the compression library and is
4591   subject to change. Applications should only use zlib.h.
4592 */
4593
4594extern int inflate_fast OF((
4595    uInt,
4596    uInt,
4597    inflate_huft *,
4598    inflate_huft *,
4599    inflate_blocks_statef *,
4600    z_streamp ));
4601/* --- inffast.h */
4602
4603/* simplify the use of the inflate_huft type with some defines */
4604#define base more.Base
4605#define next more.Next
4606#define exop word.what.Exop
4607#define bits word.what.Bits
4608
4609/* inflate codes private state */
4610struct inflate_codes_state {
4611
4612  /* mode */
4613  enum {        /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4614      START,    /* x: set up for LEN */
4615      LEN,      /* i: get length/literal/eob next */
4616      LENEXT,   /* i: getting length extra (have base) */
4617      DIST,     /* i: get distance next */
4618      DISTEXT,  /* i: getting distance extra */
4619      COPY,     /* o: copying bytes in window, waiting for space */
4620      LIT,      /* o: got literal, waiting for output space */
4621      WASH,     /* o: got eob, possibly still output waiting */
4622      END,      /* x: got eob and all data flushed */
4623      BADCODE}  /* x: got error */
4624    mode;               /* current inflate_codes mode */
4625
4626  /* mode dependent information */
4627  uInt len;
4628  union {
4629    struct {
4630      inflate_huft *tree;       /* pointer into tree */
4631      uInt need;                /* bits needed */
4632    } code;             /* if LEN or DIST, where in tree */
4633    uInt lit;           /* if LIT, literal */
4634    struct {
4635      uInt get;                 /* bits to get for extra */
4636      uInt dist;                /* distance back to copy from */
4637    } copy;             /* if EXT or COPY, where and how much */
4638  } sub;                /* submode */
4639
4640  /* mode independent information */
4641  Byte lbits;           /* ltree bits decoded per branch */
4642  Byte dbits;           /* dtree bits decoder per branch */
4643  inflate_huft *ltree;          /* literal/length/eob tree */
4644  inflate_huft *dtree;          /* distance tree */
4645
4646};
4647
4648
4649inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4650uInt bl, bd;
4651inflate_huft *tl;
4652inflate_huft *td; /* need separate declaration for Borland C++ */
4653z_streamp z;
4654{
4655  inflate_codes_statef *c;
4656
4657  if ((c = (inflate_codes_statef *)
4658       ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4659  {
4660    c->mode = START;
4661    c->lbits = (Byte)bl;
4662    c->dbits = (Byte)bd;
4663    c->ltree = tl;
4664    c->dtree = td;
4665    Tracev((stderr, "inflate:       codes new\n"));
4666  }
4667  return c;
4668}
4669
4670
4671int inflate_codes(s, z, r)
4672inflate_blocks_statef *s;
4673z_streamp z;
4674int r;
4675{
4676  uInt j;               /* temporary storage */
4677  inflate_huft *t;      /* temporary pointer */
4678  uInt e;               /* extra bits or operation */
4679  uLong b;              /* bit buffer */
4680  uInt k;               /* bits in bit buffer */
4681  Bytef *p;             /* input data pointer */
4682  uInt n;               /* bytes available there */
4683  Bytef *q;             /* output window write pointer */
4684  uInt m;               /* bytes to end of window or read pointer */
4685  Bytef *f;             /* pointer to copy strings from */
4686  inflate_codes_statef *c = s->sub.decode.codes;  /* codes state */
4687
4688  /* copy input/output information to locals (UPDATE macro restores) */
4689  LOAD
4690
4691  /* process input and output based on current state */
4692  while (1) switch (c->mode)
4693  {             /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4694    case START:         /* x: set up for LEN */
4695#ifndef SLOW
4696      if (m >= 258 && n >= 10)
4697      {
4698        UPDATE
4699        r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4700        LOAD
4701        if (r != Z_OK)
4702        {
4703          c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4704          break;
4705        }
4706      }
4707#endif /* !SLOW */
4708      c->sub.code.need = c->lbits;
4709      c->sub.code.tree = c->ltree;
4710      c->mode = LEN;
4711    case LEN:           /* i: get length/literal/eob next */
4712      j = c->sub.code.need;
4713      NEEDBITS(j)
4714      t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4715      DUMPBITS(t->bits)
4716      e = (uInt)(t->exop);
4717      if (e == 0)               /* literal */
4718      {
4719        c->sub.lit = t->base;
4720        Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4721                 "inflate:         literal '%c'\n" :
4722                 "inflate:         literal 0x%02x\n", t->base));
4723        c->mode = LIT;
4724        break;
4725      }
4726      if (e & 16)               /* length */
4727      {
4728        c->sub.copy.get = e & 15;
4729        c->len = t->base;
4730        c->mode = LENEXT;
4731        break;
4732      }
4733      if ((e & 64) == 0)        /* next table */
4734      {
4735        c->sub.code.need = e;
4736        c->sub.code.tree = t->next;
4737        break;
4738      }
4739      if (e & 32)               /* end of block */
4740      {
4741        Tracevv((stderr, "inflate:         end of block\n"));
4742        c->mode = WASH;
4743        break;
4744      }
4745      c->mode = BADCODE;        /* invalid code */
4746      z->msg = (char*)"invalid literal/length code";
4747      r = Z_DATA_ERROR;
4748      LEAVE
4749    case LENEXT:        /* i: getting length extra (have base) */
4750      j = c->sub.copy.get;
4751      NEEDBITS(j)
4752      c->len += (uInt)b & inflate_mask[j];
4753      DUMPBITS(j)
4754      c->sub.code.need = c->dbits;
4755      c->sub.code.tree = c->dtree;
4756      Tracevv((stderr, "inflate:         length %u\n", c->len));
4757      c->mode = DIST;
4758    case DIST:          /* i: get distance next */
4759      j = c->sub.code.need;
4760      NEEDBITS(j)
4761      t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4762      DUMPBITS(t->bits)
4763      e = (uInt)(t->exop);
4764      if (e & 16)               /* distance */
4765      {
4766        c->sub.copy.get = e & 15;
4767        c->sub.copy.dist = t->base;
4768        c->mode = DISTEXT;
4769        break;
4770      }
4771      if ((e & 64) == 0)        /* next table */
4772      {
4773        c->sub.code.need = e;
4774        c->sub.code.tree = t->next;
4775        break;
4776      }
4777      c->mode = BADCODE;        /* invalid code */
4778      z->msg = (char*)"invalid distance code";
4779      r = Z_DATA_ERROR;
4780      LEAVE
4781    case DISTEXT:       /* i: getting distance extra */
4782      j = c->sub.copy.get;
4783      NEEDBITS(j)
4784      c->sub.copy.dist += (uInt)b & inflate_mask[j];
4785      DUMPBITS(j)
4786      Tracevv((stderr, "inflate:         distance %u\n", c->sub.copy.dist));
4787      c->mode = COPY;
4788    case COPY:          /* o: copying bytes in window, waiting for space */
4789#ifndef __TURBOC__ /* Turbo C bug for following expression */
4790      f = (uInt)(q - s->window) < c->sub.copy.dist ?
4791          s->end - (c->sub.copy.dist - (q - s->window)) :
4792          q - c->sub.copy.dist;
4793#else
4794      f = q - c->sub.copy.dist;
4795      if ((uInt)(q - s->window) < c->sub.copy.dist)
4796        f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
4797#endif
4798      while (c->len)
4799      {
4800        NEEDOUT
4801        OUTBYTE(*f++)
4802        if (f == s->end)
4803          f = s->window;
4804        c->len--;
4805      }
4806      c->mode = START;
4807      break;
4808    case LIT:           /* o: got literal, waiting for output space */
4809      NEEDOUT
4810      OUTBYTE(c->sub.lit)
4811      c->mode = START;
4812      break;
4813    case WASH:          /* o: got eob, possibly more output */
4814      FLUSH
4815      if (s->read != s->write)
4816        LEAVE
4817      c->mode = END;
4818    case END:
4819      r = Z_STREAM_END;
4820      LEAVE
4821    case BADCODE:       /* x: got error */
4822      r = Z_DATA_ERROR;
4823      LEAVE
4824    default:
4825      r = Z_STREAM_ERROR;
4826      LEAVE
4827  }
4828}
4829
4830
4831void inflate_codes_free(c, z)
4832inflate_codes_statef *c;
4833z_streamp z;
4834{
4835  ZFREE(z, c);
4836  Tracev((stderr, "inflate:       codes free\n"));
4837}
4838/* --- infcodes.c */
4839
4840/* +++ infutil.c */
4841/* inflate_util.c -- data and routines common to blocks and codes
4842 * Copyright (C) 1995-1996 Mark Adler
4843 * For conditions of distribution and use, see copyright notice in zlib.h
4844 */
4845
4846/* #include "zutil.h" */
4847/* #include "infblock.h" */
4848/* #include "inftrees.h" */
4849/* #include "infcodes.h" */
4850/* #include "infutil.h" */
4851
4852#ifndef NO_DUMMY_DECL
4853struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4854#endif
4855
4856/* And'ing with mask[n] masks the lower n bits */
4857uInt inflate_mask[17] = {
4858    0x0000,
4859    0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
4860    0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
4861};
4862
4863
4864/* copy as much as possible from the sliding window to the output area */
4865int inflate_flush(s, z, r)
4866inflate_blocks_statef *s;
4867z_streamp z;
4868int r;
4869{
4870  uInt n;
4871  Bytef *p;
4872  Bytef *q;
4873
4874  /* local copies of source and destination pointers */
4875  p = z->next_out;
4876  q = s->read;
4877
4878  /* compute number of bytes to copy as far as end of window */
4879  n = (uInt)((q <= s->write ? s->write : s->end) - q);
4880  if (n > z->avail_out) n = z->avail_out;
4881  if (n && r == Z_BUF_ERROR) r = Z_OK;
4882
4883  /* update counters */
4884  z->avail_out -= n;
4885  z->total_out += n;
4886
4887  /* update check information */
4888  if (s->checkfn != Z_NULL)
4889    z->adler = s->check = (*s->checkfn)(s->check, q, n);
4890
4891  /* copy as far as end of window */
4892  if (p != Z_NULL) {
4893    zmemcpy(p, q, n);
4894    p += n;
4895  }
4896  q += n;
4897
4898  /* see if more to copy at beginning of window */
4899  if (q == s->end)
4900  {
4901    /* wrap pointers */
4902    q = s->window;
4903    if (s->write == s->end)
4904      s->write = s->window;
4905
4906    /* compute bytes to copy */
4907    n = (uInt)(s->write - q);
4908    if (n > z->avail_out) n = z->avail_out;
4909    if (n && r == Z_BUF_ERROR) r = Z_OK;
4910
4911    /* update counters */
4912    z->avail_out -= n;
4913    z->total_out += n;
4914
4915    /* update check information */
4916    if (s->checkfn != Z_NULL)
4917      z->adler = s->check = (*s->checkfn)(s->check, q, n);
4918
4919    /* copy */
4920    if (p != Z_NULL) {
4921      zmemcpy(p, q, n);
4922      p += n;
4923    }
4924    q += n;
4925  }
4926
4927  /* update pointers */
4928  z->next_out = p;
4929  s->read = q;
4930
4931  /* done */
4932  return r;
4933}
4934/* --- infutil.c */
4935
4936/* +++ inffast.c */
4937/* inffast.c -- process literals and length/distance pairs fast
4938 * Copyright (C) 1995-1996 Mark Adler
4939 * For conditions of distribution and use, see copyright notice in zlib.h
4940 */
4941
4942/* #include "zutil.h" */
4943/* #include "inftrees.h" */
4944/* #include "infblock.h" */
4945/* #include "infcodes.h" */
4946/* #include "infutil.h" */
4947/* #include "inffast.h" */
4948
4949#ifndef NO_DUMMY_DECL
4950struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4951#endif
4952
4953/* simplify the use of the inflate_huft type with some defines */
4954#define base more.Base
4955#define next more.Next
4956#define exop word.what.Exop
4957#define bits word.what.Bits
4958
4959/* macros for bit input with no checking and for returning unused bytes */
4960#define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4961#define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4962
4963/* Called with number of bytes left to write in window at least 258
4964   (the maximum string length) and number of input bytes available
4965   at least ten.  The ten bytes are six bytes for the longest length/
4966   distance pair plus four bytes for overloading the bit buffer. */
4967
4968int inflate_fast(bl, bd, tl, td, s, z)
4969uInt bl, bd;
4970inflate_huft *tl;
4971inflate_huft *td; /* need separate declaration for Borland C++ */
4972inflate_blocks_statef *s;
4973z_streamp z;
4974{
4975  inflate_huft *t;      /* temporary pointer */
4976  uInt e;               /* extra bits or operation */
4977  uLong b;              /* bit buffer */
4978  uInt k;               /* bits in bit buffer */
4979  Bytef *p;             /* input data pointer */
4980  uInt n;               /* bytes available there */
4981  Bytef *q;             /* output window write pointer */
4982  uInt m;               /* bytes to end of window or read pointer */
4983  uInt ml;              /* mask for literal/length tree */
4984  uInt md;              /* mask for distance tree */
4985  uInt c;               /* bytes to copy */
4986  uInt d;               /* distance back to copy from */
4987  Bytef *r;             /* copy source pointer */
4988
4989  /* load input, output, bit values */
4990  LOAD
4991
4992  /* initialize masks */
4993  ml = inflate_mask[bl];
4994  md = inflate_mask[bd];
4995
4996  /* do until not enough input or output space for fast loop */
4997  do {                          /* assume called with m >= 258 && n >= 10 */
4998    /* get literal/length code */
4999    GRABBITS(20)                /* max bits for literal/length code */
5000    if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5001    {
5002      DUMPBITS(t->bits)
5003      Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5004                "inflate:         * literal '%c'\n" :
5005                "inflate:         * literal 0x%02x\n", t->base));
5006      *q++ = (Byte)t->base;
5007      m--;
5008      continue;
5009    }
5010    do {
5011      DUMPBITS(t->bits)
5012      if (e & 16)
5013      {
5014        /* get extra bits for length */
5015        e &= 15;
5016        c = t->base + ((uInt)b & inflate_mask[e]);
5017        DUMPBITS(e)
5018        Tracevv((stderr, "inflate:         * length %u\n", c));
5019
5020        /* decode distance base of block to copy */
5021        GRABBITS(15);           /* max bits for distance code */
5022        e = (t = td + ((uInt)b & md))->exop;
5023        do {
5024          DUMPBITS(t->bits)
5025          if (e & 16)
5026          {
5027            /* get extra bits to add to distance base */
5028            e &= 15;
5029            GRABBITS(e)         /* get extra bits (up to 13) */
5030            d = t->base + ((uInt)b & inflate_mask[e]);
5031            DUMPBITS(e)
5032            Tracevv((stderr, "inflate:         * distance %u\n", d));
5033
5034            /* do the copy */
5035            m -= c;
5036            if ((uInt)(q - s->window) >= d)     /* offset before dest */
5037            {                                   /*  just copy */
5038              r = q - d;
5039              *q++ = *r++;  c--;        /* minimum count is three, */
5040              *q++ = *r++;  c--;        /*  so unroll loop a little */
5041            }
5042            else                        /* else offset after destination */
5043            {
5044              e = d - (uInt)(q - s->window); /* bytes from offset to end */
5045              r = s->end - e;           /* pointer to offset */
5046              if (c > e)                /* if source crosses, */
5047              {
5048                c -= e;                 /* copy to end of window */
5049                do {
5050                  *q++ = *r++;
5051                } while (--e);
5052                r = s->window;          /* copy rest from start of window */
5053              }
5054            }
5055            do {                        /* copy all or what's left */
5056              *q++ = *r++;
5057            } while (--c);
5058            break;
5059          }
5060          else if ((e & 64) == 0)
5061            e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
5062          else
5063          {
5064            z->msg = (char*)"invalid distance code";
5065            UNGRAB
5066            UPDATE
5067            return Z_DATA_ERROR;
5068          }
5069        } while (1);
5070        break;
5071      }
5072      if ((e & 64) == 0)
5073      {
5074        if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
5075        {
5076          DUMPBITS(t->bits)
5077          Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5078                    "inflate:         * literal '%c'\n" :
5079                    "inflate:         * literal 0x%02x\n", t->base));
5080          *q++ = (Byte)t->base;
5081          m--;
5082          break;
5083        }
5084      }
5085      else if (e & 32)
5086      {
5087        Tracevv((stderr, "inflate:         * end of block\n"));
5088        UNGRAB
5089        UPDATE
5090        return Z_STREAM_END;
5091      }
5092      else
5093      {
5094        z->msg = (char*)"invalid literal/length code";
5095        UNGRAB
5096        UPDATE
5097        return Z_DATA_ERROR;
5098      }
5099    } while (1);
5100  } while (m >= 258 && n >= 10);
5101
5102  /* not enough input or output--restore pointers and return */
5103  UNGRAB
5104  UPDATE
5105  return Z_OK;
5106}
5107/* --- inffast.c */
5108
5109/* +++ zutil.c */
5110/* zutil.c -- target dependent utility functions for the compression library
5111 * Copyright (C) 1995-1996 Jean-loup Gailly.
5112 * For conditions of distribution and use, see copyright notice in zlib.h
5113 */
5114
5115/* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */
5116
5117#ifdef DEBUG_ZLIB
5118#include <stdio.h>
5119#endif
5120
5121/* #include "zutil.h" */
5122
5123#ifndef NO_DUMMY_DECL
5124struct internal_state      {int dummy;}; /* for buggy compilers */
5125#endif
5126
5127#ifndef STDC
5128extern void exit OF((int));
5129#endif
5130
5131const char *z_errmsg[10] = {
5132"need dictionary",     /* Z_NEED_DICT       2  */
5133"stream end",          /* Z_STREAM_END      1  */
5134"",                    /* Z_OK              0  */
5135"file error",          /* Z_ERRNO         (-1) */
5136"stream error",        /* Z_STREAM_ERROR  (-2) */
5137"data error",          /* Z_DATA_ERROR    (-3) */
5138"insufficient memory", /* Z_MEM_ERROR     (-4) */
5139"buffer error",        /* Z_BUF_ERROR     (-5) */
5140"incompatible version",/* Z_VERSION_ERROR (-6) */
5141""};
5142
5143
5144const char *zlibVersion()
5145{
5146    return ZLIB_VERSION;
5147}
5148
5149#ifdef DEBUG_ZLIB
5150void z_error (m)
5151    char *m;
5152{
5153    fprintf(stderr, "%s\n", m);
5154    exit(1);
5155}
5156#endif
5157
5158#ifndef HAVE_MEMCPY
5159
5160void zmemcpy(dest, source, len)
5161    Bytef* dest;
5162    Bytef* source;
5163    uInt  len;
5164{
5165    if (len == 0) return;
5166    do {
5167        *dest++ = *source++; /* ??? to be unrolled */
5168    } while (--len != 0);
5169}
5170
5171int zmemcmp(s1, s2, len)
5172    Bytef* s1;
5173    Bytef* s2;
5174    uInt  len;
5175{
5176    uInt j;
5177
5178    for (j = 0; j < len; j++) {
5179        if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5180    }
5181    return 0;
5182}
5183
5184void zmemzero(dest, len)
5185    Bytef* dest;
5186    uInt  len;
5187{
5188    if (len == 0) return;
5189    do {
5190        *dest++ = 0;  /* ??? to be unrolled */
5191    } while (--len != 0);
5192}
5193#endif
5194
5195#ifdef __TURBOC__
5196#if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5197/* Small and medium model in Turbo C are for now limited to near allocation
5198 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5199 */
5200#  define MY_ZCALLOC
5201
5202/* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5203 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5204 * must fix the pointer. Warning: the pointer must be put back to its
5205 * original form in order to free it, use zcfree().
5206 */
5207
5208#define MAX_PTR 10
5209/* 10*64K = 640K */
5210
5211local int next_ptr = 0;
5212
5213typedef struct ptr_table_s {
5214    voidpf org_ptr;
5215    voidpf new_ptr;
5216} ptr_table;
5217
5218local ptr_table table[MAX_PTR];
5219/* This table is used to remember the original form of pointers
5220 * to large buffers (64K). Such pointers are normalized with a zero offset.
5221 * Since MSDOS is not a preemptive multitasking OS, this table is not
5222 * protected from concurrent access. This hack doesn't work anyway on
5223 * a protected system like OS/2. Use Microsoft C instead.
5224 */
5225
5226voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5227{
5228    voidpf buf = opaque; /* just to make some compilers happy */
5229    ulg bsize = (ulg)items*size;
5230
5231    /* If we allocate less than 65520 bytes, we assume that farmalloc
5232     * will return a usable pointer which doesn't have to be normalized.
5233     */
5234    if (bsize < 65520L) {
5235        buf = farmalloc(bsize);
5236        if (*(ush*)&buf != 0) return buf;
5237    } else {
5238        buf = farmalloc(bsize + 16L);
5239    }
5240    if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5241    table[next_ptr].org_ptr = buf;
5242
5243    /* Normalize the pointer to seg:0 */
5244    *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5245    *(ush*)&buf = 0;
5246    table[next_ptr++].new_ptr = buf;
5247    return buf;
5248}
5249
5250void  zcfree (voidpf opaque, voidpf ptr)
5251{
5252    int n;
5253    if (*(ush*)&ptr != 0) { /* object < 64K */
5254        farfree(ptr);
5255        return;
5256    }
5257    /* Find the original pointer */
5258    for (n = 0; n < next_ptr; n++) {
5259        if (ptr != table[n].new_ptr) continue;
5260
5261        farfree(table[n].org_ptr);
5262        while (++n < next_ptr) {
5263            table[n-1] = table[n];
5264        }
5265        next_ptr--;
5266        return;
5267    }
5268    ptr = opaque; /* just to make some compilers happy */
5269    Assert(0, "zcfree: ptr not found");
5270}
5271#endif
5272#endif /* __TURBOC__ */
5273
5274
5275#if defined(M_I86) && !defined(__32BIT__)
5276/* Microsoft C in 16-bit mode */
5277
5278#  define MY_ZCALLOC
5279
5280#if (!defined(_MSC_VER) || (_MSC_VER < 600))
5281#  define _halloc  halloc
5282#  define _hfree   hfree
5283#endif
5284
5285voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5286{
5287    if (opaque) opaque = 0; /* to make compiler happy */
5288    return _halloc((long)items, size);
5289}
5290
5291void  zcfree (voidpf opaque, voidpf ptr)
5292{
5293    if (opaque) opaque = 0; /* to make compiler happy */
5294    _hfree(ptr);
5295}
5296
5297#endif /* MSC */
5298
5299
5300#ifndef MY_ZCALLOC /* Any system without a special alloc function */
5301
5302#ifndef STDC
5303extern voidp  calloc OF((uInt items, uInt size));
5304extern void   free   OF((voidpf ptr));
5305#endif
5306
5307voidpf zcalloc (opaque, items, size)
5308    voidpf opaque;
5309    unsigned items;
5310    unsigned size;
5311{
5312    if (opaque) items += size - size; /* make compiler happy */
5313    return (voidpf)calloc(items, size);
5314}
5315
5316void  zcfree (opaque, ptr)
5317    voidpf opaque;
5318    voidpf ptr;
5319{
5320    free(ptr);
5321    if (opaque) return; /* make compiler happy */
5322}
5323
5324#endif /* MY_ZCALLOC */
5325/* --- zutil.c */
5326
5327/* +++ adler32.c */
5328/* adler32.c -- compute the Adler-32 checksum of a data stream
5329 * Copyright (C) 1995-1996 Mark Adler
5330 * For conditions of distribution and use, see copyright notice in zlib.h
5331 */
5332
5333/* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */
5334
5335/* #include "zlib.h" */
5336
5337#define BASE 65521L /* largest prime smaller than 65536 */
5338#define NMAX 5552
5339/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5340
5341#define DO1(buf,i)  {s1 += buf[i]; s2 += s1;}
5342#define DO2(buf,i)  DO1(buf,i); DO1(buf,i+1);
5343#define DO4(buf,i)  DO2(buf,i); DO2(buf,i+2);
5344#define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);
5345#define DO16(buf)   DO8(buf,0); DO8(buf,8);
5346
5347/* ========================================================================= */
5348uLong adler32(adler, buf, len)
5349    uLong adler;
5350    const Bytef *buf;
5351    uInt len;
5352{
5353    unsigned long s1 = adler & 0xffff;
5354    unsigned long s2 = (adler >> 16) & 0xffff;
5355    int k;
5356
5357    if (buf == Z_NULL) return 1L;
5358
5359    while (len > 0) {
5360        k = len < NMAX ? len : NMAX;
5361        len -= k;
5362        while (k >= 16) {
5363            DO16(buf);
5364            buf += 16;
5365            k -= 16;
5366        }
5367        if (k != 0) do {
5368            s1 += *buf++;
5369            s2 += s1;
5370        } while (--k);
5371        s1 %= BASE;
5372        s2 %= BASE;
5373    }
5374    return (s2 << 16) | s1;
5375}
5376/* --- adler32.c */
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