nataraid(4): Add devstat support.
[dragonfly.git] / sys / net / zlib.c
CommitLineData
984263bc
MD
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 * $FreeBSD: src/sys/net/zlib.c,v 1.10.2.3 2002/03/24 23:12:48 jedgar Exp $
a7fa04e6 14 * $DragonFly: src/sys/net/zlib.c,v 1.11 2007/01/07 00:41:29 dillon Exp $
984263bc
MD
15 */
16
17/*
18 * ==FILEVERSION 971210==
19 *
20 * This marker is used by the Linux installation script to determine
21 * whether an up-to-date version of this file is already installed.
22 */
23
24#define NO_DUMMY_DECL
25#define NO_ZCFUNCS
26#define MY_ZCALLOC
27
9a7f3897 28#if (defined(__DragonFly__) || defined(__FreeBSD__)) && defined(_KERNEL)
984263bc
MD
29#define inflate inflate_ppp /* FreeBSD already has an inflate :-( */
30#endif
31
32
33/* +++ zutil.h */
34/* zutil.h -- internal interface and configuration of the compression library
35 * Copyright (C) 1995-1996 Jean-loup Gailly.
36 * For conditions of distribution and use, see copyright notice in zlib.h
37 */
38
39/* WARNING: this file should *not* be used by applications. It is
40 part of the implementation of the compression library and is
41 subject to change. Applications should only use zlib.h.
42 */
43
44/* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */
45
46#ifndef _Z_UTIL_H
47#define _Z_UTIL_H
48
49#ifdef _KERNEL
50#include <net/zlib.h>
51#else
52#include "zlib.h"
53#endif
54
55#ifdef _KERNEL
56/* Assume this is a *BSD or SVR4 kernel */
a46cfb91 57#include <sys/param.h>
984263bc
MD
58#include <sys/types.h>
59#include <sys/time.h>
60#include <sys/systm.h>
09c280ec 61#include <sys/module.h>
984263bc
MD
62# define HAVE_MEMCPY
63# define memcpy(d, s, n) bcopy((s), (d), (n))
64# define memset(d, v, n) bzero((d), (n))
65# define memcmp bcmp
66
67#else
68#if defined(__KERNEL__)
69/* Assume this is a Linux kernel */
70#include <linux/string.h>
71#define HAVE_MEMCPY
72
73#else /* not kernel */
74
75#if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS)
76# include <stddef.h>
77# include <errno.h>
78#else
79 extern int errno;
80#endif
81#ifdef STDC
82# include <string.h>
83# include <stdlib.h>
84#endif
85#endif /* __KERNEL__ */
86#endif /* _KERNEL */
87
88#ifndef local
89# define local static
90#endif
91/* compile with -Dlocal if your debugger can't find static symbols */
92
93typedef unsigned char uch;
94typedef uch FAR uchf;
95typedef unsigned short ush;
96typedef ush FAR ushf;
97typedef unsigned long ulg;
98
70068ffd
SW
99static const char *z_errmsg[10] = {
100"need dictionary", /* Z_NEED_DICT 2 */
101"stream end", /* Z_STREAM_END 1 */
102"", /* Z_OK 0 */
103"file error", /* Z_ERRNO (-1) */
104"stream error", /* Z_STREAM_ERROR (-2) */
105"data error", /* Z_DATA_ERROR (-3) */
106"insufficient memory", /* Z_MEM_ERROR (-4) */
107"buffer error", /* Z_BUF_ERROR (-5) */
108"incompatible version",/* Z_VERSION_ERROR (-6) */
109""};
984263bc
MD
110
111#define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
112
113#define ERR_RETURN(strm,err) \
114 return (strm->msg = (const char*)ERR_MSG(err), (err))
115/* To be used only when the state is known to be valid */
116
117 /* common constants */
118
119#ifndef DEF_WBITS
120# define DEF_WBITS MAX_WBITS
121#endif
122/* default windowBits for decompression. MAX_WBITS is for compression only */
123
124#if MAX_MEM_LEVEL >= 8
125# define DEF_MEM_LEVEL 8
126#else
127# define DEF_MEM_LEVEL MAX_MEM_LEVEL
128#endif
129/* default memLevel */
130
131#define STORED_BLOCK 0
132#define STATIC_TREES 1
133#define DYN_TREES 2
134/* The three kinds of block type */
135
136#define MIN_MATCH 3
137#define MAX_MATCH 258
138/* The minimum and maximum match lengths */
139
140#define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
141
142 /* target dependencies */
143
144#ifdef MSDOS
145# define OS_CODE 0x00
146# ifdef __TURBOC__
147# include <alloc.h>
148# else /* MSC or DJGPP */
149# include <malloc.h>
150# endif
151#endif
152
153#ifdef OS2
154# define OS_CODE 0x06
155#endif
156
157#ifdef WIN32 /* Window 95 & Windows NT */
158# define OS_CODE 0x0b
159#endif
160
161#if defined(VAXC) || defined(VMS)
162# define OS_CODE 0x02
163# define FOPEN(name, mode) \
164 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
165#endif
166
167#ifdef AMIGA
168# define OS_CODE 0x01
169#endif
170
171#if defined(ATARI) || defined(atarist)
172# define OS_CODE 0x05
173#endif
174
175#ifdef MACOS
176# define OS_CODE 0x07
177#endif
178
179#ifdef __50SERIES /* Prime/PRIMOS */
180# define OS_CODE 0x0F
181#endif
182
183#ifdef TOPS20
184# define OS_CODE 0x0a
185#endif
186
187#if defined(_BEOS_) || defined(RISCOS)
188# define fdopen(fd,mode) NULL /* No fdopen() */
189#endif
190
191 /* Common defaults */
192
193#ifndef OS_CODE
194# define OS_CODE 0x03 /* assume Unix */
195#endif
196
197#ifndef FOPEN
198# define FOPEN(name, mode) fopen((name), (mode))
199#endif
200
201 /* functions */
202
203#ifdef HAVE_STRERROR
204 extern char *strerror OF((int));
205# define zstrerror(errnum) strerror(errnum)
206#else
207# define zstrerror(errnum) ""
208#endif
209
210#if defined(pyr)
211# define NO_MEMCPY
212#endif
213#if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
214 /* Use our own functions for small and medium model with MSC <= 5.0.
215 * You may have to use the same strategy for Borland C (untested).
216 */
217# define NO_MEMCPY
218#endif
219#if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
220# define HAVE_MEMCPY
221#endif
222#ifdef HAVE_MEMCPY
223# ifdef SMALL_MEDIUM /* MSDOS small or medium model */
224# define zmemcpy _fmemcpy
225# define zmemcmp _fmemcmp
226# define zmemzero(dest, len) _fmemset(dest, 0, len)
227# else
228# define zmemcpy memcpy
229# define zmemcmp memcmp
230# define zmemzero(dest, len) memset(dest, 0, len)
231# endif
232#else
233 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
234 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len));
235 extern void zmemzero OF((Bytef* dest, uInt len));
236#endif
237
238/* Diagnostic functions */
239#ifdef DEBUG_ZLIB
240# include <stdio.h>
241# ifndef verbose
242# define verbose 0
243# endif
244 extern void z_error OF((char *m));
245# define Assert(cond,msg) {if(!(cond)) z_error(msg);}
246# define Trace(x) fprintf x
247# define Tracev(x) {if (verbose) fprintf x ;}
248# define Tracevv(x) {if (verbose>1) fprintf x ;}
249# define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
250# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
251#else
252# define Assert(cond,msg)
253# define Trace(x)
254# define Tracev(x)
255# define Tracevv(x)
256# define Tracec(c,x)
257# define Tracecv(c,x)
258#endif
259
260
261typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));
262
263voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
264void zcfree OF((voidpf opaque, voidpf ptr));
265
266#define ZALLOC(strm, items, size) \
267 (*((strm)->zalloc))((strm)->opaque, (items), (size))
268#define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
269#define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
270
271#endif /* _Z_UTIL_H */
272/* --- zutil.h */
273
274/* +++ deflate.h */
275/* deflate.h -- internal compression state
276 * Copyright (C) 1995-1996 Jean-loup Gailly
277 * For conditions of distribution and use, see copyright notice in zlib.h
278 */
279
280/* WARNING: this file should *not* be used by applications. It is
281 part of the implementation of the compression library and is
282 subject to change. Applications should only use zlib.h.
283 */
284
285/* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */
286
287#ifndef _DEFLATE_H
288#define _DEFLATE_H
289
290/* #include "zutil.h" */
291
292/* ===========================================================================
293 * Internal compression state.
294 */
295
296#define LENGTH_CODES 29
297/* number of length codes, not counting the special END_BLOCK code */
298
299#define LITERALS 256
300/* number of literal bytes 0..255 */
301
302#define L_CODES (LITERALS+1+LENGTH_CODES)
303/* number of Literal or Length codes, including the END_BLOCK code */
304
305#define D_CODES 30
306/* number of distance codes */
307
308#define BL_CODES 19
309/* number of codes used to transfer the bit lengths */
310
311#define HEAP_SIZE (2*L_CODES+1)
312/* maximum heap size */
313
314#define MAX_BITS 15
315/* All codes must not exceed MAX_BITS bits */
316
317#define INIT_STATE 42
318#define BUSY_STATE 113
319#define FINISH_STATE 666
320/* Stream status */
321
322
323/* Data structure describing a single value and its code string. */
324typedef struct ct_data_s {
325 union {
326 ush freq; /* frequency count */
327 ush code; /* bit string */
328 } fc;
329 union {
330 ush dad; /* father node in Huffman tree */
331 ush len; /* length of bit string */
332 } dl;
333} FAR ct_data;
334
335#define Freq fc.freq
336#define Code fc.code
337#define Dad dl.dad
338#define Len dl.len
339
340typedef struct static_tree_desc_s static_tree_desc;
341
342typedef struct tree_desc_s {
343 ct_data *dyn_tree; /* the dynamic tree */
344 int max_code; /* largest code with non zero frequency */
345 static_tree_desc *stat_desc; /* the corresponding static tree */
346} FAR tree_desc;
347
348typedef ush Pos;
349typedef Pos FAR Posf;
350typedef unsigned IPos;
351
352/* A Pos is an index in the character window. We use short instead of int to
353 * save space in the various tables. IPos is used only for parameter passing.
354 */
355
356typedef struct deflate_state {
357 z_streamp strm; /* pointer back to this zlib stream */
358 int status; /* as the name implies */
359 Bytef *pending_buf; /* output still pending */
360 ulg pending_buf_size; /* size of pending_buf */
361 Bytef *pending_out; /* next pending byte to output to the stream */
362 int pending; /* nb of bytes in the pending buffer */
363 int noheader; /* suppress zlib header and adler32 */
364 Byte data_type; /* UNKNOWN, BINARY or ASCII */
365 Byte method; /* STORED (for zip only) or DEFLATED */
366 int last_flush; /* value of flush param for previous deflate call */
367
368 /* used by deflate.c: */
369
370 uInt w_size; /* LZ77 window size (32K by default) */
371 uInt w_bits; /* log2(w_size) (8..16) */
372 uInt w_mask; /* w_size - 1 */
373
374 Bytef *window;
375 /* Sliding window. Input bytes are read into the second half of the window,
376 * and move to the first half later to keep a dictionary of at least wSize
377 * bytes. With this organization, matches are limited to a distance of
378 * wSize-MAX_MATCH bytes, but this ensures that IO is always
379 * performed with a length multiple of the block size. Also, it limits
380 * the window size to 64K, which is quite useful on MSDOS.
381 * To do: use the user input buffer as sliding window.
382 */
383
384 ulg window_size;
385 /* Actual size of window: 2*wSize, except when the user input buffer
386 * is directly used as sliding window.
387 */
388
389 Posf *prev;
390 /* Link to older string with same hash index. To limit the size of this
391 * array to 64K, this link is maintained only for the last 32K strings.
392 * An index in this array is thus a window index modulo 32K.
393 */
394
395 Posf *head; /* Heads of the hash chains or NIL. */
396
397 uInt ins_h; /* hash index of string to be inserted */
398 uInt hash_size; /* number of elements in hash table */
399 uInt hash_bits; /* log2(hash_size) */
400 uInt hash_mask; /* hash_size-1 */
401
402 uInt hash_shift;
403 /* Number of bits by which ins_h must be shifted at each input
404 * step. It must be such that after MIN_MATCH steps, the oldest
405 * byte no longer takes part in the hash key, that is:
406 * hash_shift * MIN_MATCH >= hash_bits
407 */
408
409 long block_start;
410 /* Window position at the beginning of the current output block. Gets
411 * negative when the window is moved backwards.
412 */
413
414 uInt match_length; /* length of best match */
415 IPos prev_match; /* previous match */
416 int match_available; /* set if previous match exists */
417 uInt strstart; /* start of string to insert */
418 uInt match_start; /* start of matching string */
419 uInt lookahead; /* number of valid bytes ahead in window */
420
421 uInt prev_length;
422 /* Length of the best match at previous step. Matches not greater than this
423 * are discarded. This is used in the lazy match evaluation.
424 */
425
426 uInt max_chain_length;
427 /* To speed up deflation, hash chains are never searched beyond this
428 * length. A higher limit improves compression ratio but degrades the
429 * speed.
430 */
431
432 uInt max_lazy_match;
433 /* Attempt to find a better match only when the current match is strictly
434 * smaller than this value. This mechanism is used only for compression
435 * levels >= 4.
436 */
437# define max_insert_length max_lazy_match
438 /* Insert new strings in the hash table only if the match length is not
439 * greater than this length. This saves time but degrades compression.
440 * max_insert_length is used only for compression levels <= 3.
441 */
442
443 int level; /* compression level (1..9) */
444 int strategy; /* favor or force Huffman coding*/
445
446 uInt good_match;
447 /* Use a faster search when the previous match is longer than this */
448
449 int nice_match; /* Stop searching when current match exceeds this */
450
451 /* used by trees.c: */
452 /* Didn't use ct_data typedef below to supress compiler warning */
453 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
454 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
455 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
456
457 struct tree_desc_s l_desc; /* desc. for literal tree */
458 struct tree_desc_s d_desc; /* desc. for distance tree */
459 struct tree_desc_s bl_desc; /* desc. for bit length tree */
460
461 ush bl_count[MAX_BITS+1];
462 /* number of codes at each bit length for an optimal tree */
463
464 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
465 int heap_len; /* number of elements in the heap */
466 int heap_max; /* element of largest frequency */
467 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
468 * The same heap array is used to build all trees.
469 */
470
471 uch depth[2*L_CODES+1];
472 /* Depth of each subtree used as tie breaker for trees of equal frequency
473 */
474
475 uchf *l_buf; /* buffer for literals or lengths */
476
477 uInt lit_bufsize;
478 /* Size of match buffer for literals/lengths. There are 4 reasons for
479 * limiting lit_bufsize to 64K:
480 * - frequencies can be kept in 16 bit counters
481 * - if compression is not successful for the first block, all input
482 * data is still in the window so we can still emit a stored block even
483 * when input comes from standard input. (This can also be done for
484 * all blocks if lit_bufsize is not greater than 32K.)
485 * - if compression is not successful for a file smaller than 64K, we can
486 * even emit a stored file instead of a stored block (saving 5 bytes).
487 * This is applicable only for zip (not gzip or zlib).
488 * - creating new Huffman trees less frequently may not provide fast
489 * adaptation to changes in the input data statistics. (Take for
490 * example a binary file with poorly compressible code followed by
491 * a highly compressible string table.) Smaller buffer sizes give
492 * fast adaptation but have of course the overhead of transmitting
493 * trees more frequently.
494 * - I can't count above 4
495 */
496
497 uInt last_lit; /* running index in l_buf */
498
499 ushf *d_buf;
500 /* Buffer for distances. To simplify the code, d_buf and l_buf have
501 * the same number of elements. To use different lengths, an extra flag
502 * array would be necessary.
503 */
504
505 ulg opt_len; /* bit length of current block with optimal trees */
506 ulg static_len; /* bit length of current block with static trees */
507 ulg compressed_len; /* total bit length of compressed file */
508 uInt matches; /* number of string matches in current block */
509 int last_eob_len; /* bit length of EOB code for last block */
510
511#ifdef DEBUG_ZLIB
512 ulg bits_sent; /* bit length of the compressed data */
513#endif
514
515 ush bi_buf;
516 /* Output buffer. bits are inserted starting at the bottom (least
517 * significant bits).
518 */
519 int bi_valid;
520 /* Number of valid bits in bi_buf. All bits above the last valid bit
521 * are always zero.
522 */
523
524} FAR deflate_state;
525
526/* Output a byte on the stream.
527 * IN assertion: there is enough room in pending_buf.
528 */
529#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
530
531
532#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
533/* Minimum amount of lookahead, except at the end of the input file.
534 * See deflate.c for comments about the MIN_MATCH+1.
535 */
536
537#define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
538/* In order to simplify the code, particularly on 16 bit machines, match
539 * distances are limited to MAX_DIST instead of WSIZE.
540 */
541
542 /* in trees.c */
543void _tr_init OF((deflate_state *s));
544int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
545ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
546 int eof));
547void _tr_align OF((deflate_state *s));
548void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
549 int eof));
550void _tr_stored_type_only OF((deflate_state *));
551
552#endif
553/* --- deflate.h */
554
555/* +++ deflate.c */
556/* deflate.c -- compress data using the deflation algorithm
557 * Copyright (C) 1995-1996 Jean-loup Gailly.
558 * For conditions of distribution and use, see copyright notice in zlib.h
559 */
560
561/*
562 * ALGORITHM
563 *
564 * The "deflation" process depends on being able to identify portions
565 * of the input text which are identical to earlier input (within a
566 * sliding window trailing behind the input currently being processed).
567 *
568 * The most straightforward technique turns out to be the fastest for
569 * most input files: try all possible matches and select the longest.
570 * The key feature of this algorithm is that insertions into the string
571 * dictionary are very simple and thus fast, and deletions are avoided
572 * completely. Insertions are performed at each input character, whereas
573 * string matches are performed only when the previous match ends. So it
574 * is preferable to spend more time in matches to allow very fast string
575 * insertions and avoid deletions. The matching algorithm for small
576 * strings is inspired from that of Rabin & Karp. A brute force approach
577 * is used to find longer strings when a small match has been found.
578 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
579 * (by Leonid Broukhis).
580 * A previous version of this file used a more sophisticated algorithm
581 * (by Fiala and Greene) which is guaranteed to run in linear amortized
582 * time, but has a larger average cost, uses more memory and is patented.
583 * However the F&G algorithm may be faster for some highly redundant
584 * files if the parameter max_chain_length (described below) is too large.
585 *
586 * ACKNOWLEDGEMENTS
587 *
588 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
589 * I found it in 'freeze' written by Leonid Broukhis.
590 * Thanks to many people for bug reports and testing.
591 *
592 * REFERENCES
593 *
594 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
595 * Available in ftp://ds.internic.net/rfc/rfc1951.txt
596 *
597 * A description of the Rabin and Karp algorithm is given in the book
598 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
599 *
600 * Fiala,E.R., and Greene,D.H.
601 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
602 *
603 */
604
605/* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */
606
607/* #include "deflate.h" */
608
609char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly ";
610/*
611 If you use the zlib library in a product, an acknowledgment is welcome
612 in the documentation of your product. If for some reason you cannot
613 include such an acknowledgment, I would appreciate that you keep this
614 copyright string in the executable of your product.
615 */
616
617/* ===========================================================================
618 * Function prototypes.
619 */
620typedef enum {
621 need_more, /* block not completed, need more input or more output */
622 block_done, /* block flush performed */
623 finish_started, /* finish started, need only more output at next deflate */
624 finish_done /* finish done, accept no more input or output */
625} block_state;
626
627typedef block_state (*compress_func) OF((deflate_state *s, int flush));
628/* Compression function. Returns the block state after the call. */
629
630local void fill_window OF((deflate_state *s));
631local block_state deflate_stored OF((deflate_state *s, int flush));
632local block_state deflate_fast OF((deflate_state *s, int flush));
633local block_state deflate_slow OF((deflate_state *s, int flush));
634local void lm_init OF((deflate_state *s));
635local void putShortMSB OF((deflate_state *s, uInt b));
636local void flush_pending OF((z_streamp strm));
637local int read_buf OF((z_streamp strm, charf *buf, unsigned size));
638#ifdef ASMV
639 void match_init OF((void)); /* asm code initialization */
640 uInt longest_match OF((deflate_state *s, IPos cur_match));
641#else
642local uInt longest_match OF((deflate_state *s, IPos cur_match));
643#endif
644
645#ifdef DEBUG_ZLIB
646local void check_match OF((deflate_state *s, IPos start, IPos match,
647 int length));
648#endif
649
650/* ===========================================================================
651 * Local data
652 */
653
654#define NIL 0
655/* Tail of hash chains */
656
657#ifndef TOO_FAR
658# define TOO_FAR 4096
659#endif
660/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
661
662#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
663/* Minimum amount of lookahead, except at the end of the input file.
664 * See deflate.c for comments about the MIN_MATCH+1.
665 */
666
667/* Values for max_lazy_match, good_match and max_chain_length, depending on
668 * the desired pack level (0..9). The values given below have been tuned to
669 * exclude worst case performance for pathological files. Better values may be
670 * found for specific files.
671 */
672typedef struct config_s {
673 ush good_length; /* reduce lazy search above this match length */
674 ush max_lazy; /* do not perform lazy search above this match length */
675 ush nice_length; /* quit search above this match length */
676 ush max_chain;
677 compress_func func;
678} config;
679
680local config configuration_table[10] = {
681/* good lazy nice chain */
682/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
683/* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */
684/* 2 */ {4, 5, 16, 8, deflate_fast},
685/* 3 */ {4, 6, 32, 32, deflate_fast},
686
687/* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
688/* 5 */ {8, 16, 32, 32, deflate_slow},
689/* 6 */ {8, 16, 128, 128, deflate_slow},
690/* 7 */ {8, 32, 128, 256, deflate_slow},
691/* 8 */ {32, 128, 258, 1024, deflate_slow},
692/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
693
694/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
695 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
696 * meaning.
697 */
698
699#define EQUAL 0
700/* result of memcmp for equal strings */
701
702#ifndef NO_DUMMY_DECL
703struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
704#endif
705
706/* ===========================================================================
707 * Update a hash value with the given input byte
708 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
709 * input characters, so that a running hash key can be computed from the
710 * previous key instead of complete recalculation each time.
711 */
712#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
713
714
715/* ===========================================================================
716 * Insert string str in the dictionary and set match_head to the previous head
717 * of the hash chain (the most recent string with same hash key). Return
718 * the previous length of the hash chain.
719 * IN assertion: all calls to to INSERT_STRING are made with consecutive
720 * input characters and the first MIN_MATCH bytes of str are valid
721 * (except for the last MIN_MATCH-1 bytes of the input file).
722 */
723#define INSERT_STRING(s, str, match_head) \
724 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
725 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
726 s->head[s->ins_h] = (Pos)(str))
727
728/* ===========================================================================
729 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
730 * prev[] will be initialized on the fly.
731 */
732#define CLEAR_HASH(s) \
733 s->head[s->hash_size-1] = NIL; \
734 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
735
736/* ========================================================================= */
bf8c57c6
SW
737int
738deflateInit_(z_streamp strm, int level, const char * version,
739 int stream_size)
984263bc
MD
740{
741 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
742 Z_DEFAULT_STRATEGY, version, stream_size);
743 /* To do: ignore strm->next_in if we use it as window */
744}
745
746/* ========================================================================= */
bf8c57c6
SW
747int
748deflateInit2_(z_streamp strm, int level, int method, int windowBits,
749 int memLevel, int strategy, const char *version,
750 int stream_size)
984263bc
MD
751{
752 deflate_state *s;
753 int noheader = 0;
754 static char* my_version = ZLIB_VERSION;
755
756 ushf *overlay;
757 /* We overlay pending_buf and d_buf+l_buf. This works since the average
758 * output size for (length,distance) codes is <= 24 bits.
759 */
760
761 if (version == Z_NULL || version[0] != my_version[0] ||
762 stream_size != sizeof(z_stream)) {
763 return Z_VERSION_ERROR;
764 }
765 if (strm == Z_NULL) return Z_STREAM_ERROR;
766
767 strm->msg = Z_NULL;
768#ifndef NO_ZCFUNCS
769 if (strm->zalloc == Z_NULL) {
770 strm->zalloc = zcalloc;
771 strm->opaque = (voidpf)0;
772 }
773 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
774#endif
775
776 if (level == Z_DEFAULT_COMPRESSION) level = 6;
777
778 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
779 noheader = 1;
780 windowBits = -windowBits;
781 }
782 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
783 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
784 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
785 return Z_STREAM_ERROR;
786 }
787 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
788 if (s == Z_NULL) return Z_MEM_ERROR;
789 strm->state = (struct internal_state FAR *)s;
790 s->strm = strm;
791
792 s->noheader = noheader;
793 s->w_bits = windowBits;
794 s->w_size = 1 << s->w_bits;
795 s->w_mask = s->w_size - 1;
796
797 s->hash_bits = memLevel + 7;
798 s->hash_size = 1 << s->hash_bits;
799 s->hash_mask = s->hash_size - 1;
800 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
801
802 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
803 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
804 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
805
806 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
807
808 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
809 s->pending_buf = (uchf *) overlay;
810 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
811
812 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
813 s->pending_buf == Z_NULL) {
814 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR);
815 deflateEnd (strm);
816 return Z_MEM_ERROR;
817 }
818 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
819 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
820
821 s->level = level;
822 s->strategy = strategy;
823 s->method = (Byte)method;
824
825 return deflateReset(strm);
826}
827
828/* ========================================================================= */
bf8c57c6
SW
829int
830deflateSetDictionary(z_streamp strm, const Bytef *dictionary, uInt dictLength)
984263bc
MD
831{
832 deflate_state *s;
833 uInt length = dictLength;
834 uInt n;
835 IPos hash_head = 0;
836
837 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
838 return Z_STREAM_ERROR;
839
840 s = (deflate_state *) strm->state;
841 if (s->status != INIT_STATE) return Z_STREAM_ERROR;
842
843 strm->adler = adler32(strm->adler, dictionary, dictLength);
844
845 if (length < MIN_MATCH) return Z_OK;
846 if (length > MAX_DIST(s)) {
847 length = MAX_DIST(s);
848#ifndef USE_DICT_HEAD
849 dictionary += dictLength - length; /* use the tail of the dictionary */
850#endif
851 }
852 zmemcpy((charf *)s->window, dictionary, length);
853 s->strstart = length;
854 s->block_start = (long)length;
855
856 /* Insert all strings in the hash table (except for the last two bytes).
857 * s->lookahead stays null, so s->ins_h will be recomputed at the next
858 * call of fill_window.
859 */
860 s->ins_h = s->window[0];
861 UPDATE_HASH(s, s->ins_h, s->window[1]);
862 for (n = 0; n <= length - MIN_MATCH; n++) {
863 INSERT_STRING(s, n, hash_head);
864 }
865 if (hash_head) hash_head = 0; /* to make compiler happy */
866 return Z_OK;
867}
868
869/* ========================================================================= */
bf8c57c6
SW
870int
871deflateReset(z_streamp strm)
984263bc
MD
872{
873 deflate_state *s;
874
875 if (strm == Z_NULL || strm->state == Z_NULL ||
876 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
877
878 strm->total_in = strm->total_out = 0;
879 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
880 strm->data_type = Z_UNKNOWN;
881
882 s = (deflate_state *)strm->state;
883 s->pending = 0;
884 s->pending_out = s->pending_buf;
885
886 if (s->noheader < 0) {
887 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
888 }
889 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
890 strm->adler = 1;
891 s->last_flush = Z_NO_FLUSH;
892
893 _tr_init(s);
894 lm_init(s);
895
896 return Z_OK;
897}
898
899/* ========================================================================= */
bf8c57c6
SW
900int
901deflateParams(z_streamp strm, int level, int strategy)
984263bc
MD
902{
903 deflate_state *s;
904 compress_func func;
905 int err = Z_OK;
906
907 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
908 s = (deflate_state *) strm->state;
909
910 if (level == Z_DEFAULT_COMPRESSION) {
911 level = 6;
912 }
913 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
914 return Z_STREAM_ERROR;
915 }
916 func = configuration_table[s->level].func;
917
918 if (func != configuration_table[level].func && strm->total_in != 0) {
919 /* Flush the last buffer: */
920 err = deflate(strm, Z_PARTIAL_FLUSH);
921 }
922 if (s->level != level) {
923 s->level = level;
924 s->max_lazy_match = configuration_table[level].max_lazy;
925 s->good_match = configuration_table[level].good_length;
926 s->nice_match = configuration_table[level].nice_length;
927 s->max_chain_length = configuration_table[level].max_chain;
928 }
929 s->strategy = strategy;
930 return err;
931}
932
933/* =========================================================================
934 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
935 * IN assertion: the stream state is correct and there is enough room in
936 * pending_buf.
937 */
bf8c57c6
SW
938local void
939putShortMSB(deflate_state *s, uInt b)
984263bc
MD
940{
941 put_byte(s, (Byte)(b >> 8));
942 put_byte(s, (Byte)(b & 0xff));
943}
944
945/* =========================================================================
946 * Flush as much pending output as possible. All deflate() output goes
947 * through this function so some applications may wish to modify it
948 * to avoid allocating a large strm->next_out buffer and copying into it.
949 * (See also read_buf()).
950 */
bf8c57c6
SW
951local void
952flush_pending(z_streamp strm)
984263bc
MD
953{
954 deflate_state *s = (deflate_state *) strm->state;
955 unsigned len = s->pending;
956
957 if (len > strm->avail_out) len = strm->avail_out;
958 if (len == 0) return;
959
960 if (strm->next_out != Z_NULL) {
961 zmemcpy(strm->next_out, s->pending_out, len);
962 strm->next_out += len;
963 }
964 s->pending_out += len;
965 strm->total_out += len;
966 strm->avail_out -= len;
967 s->pending -= len;
968 if (s->pending == 0) {
969 s->pending_out = s->pending_buf;
970 }
971}
972
973/* ========================================================================= */
bf8c57c6
SW
974int
975deflate(z_streamp strm, int flush)
984263bc
MD
976{
977 int old_flush; /* value of flush param for previous deflate call */
978 deflate_state *s;
979
980 if (strm == Z_NULL || strm->state == Z_NULL ||
981 flush > Z_FINISH || flush < 0) {
982 return Z_STREAM_ERROR;
983 }
984 s = (deflate_state *) strm->state;
985
986 if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
987 (s->status == FINISH_STATE && flush != Z_FINISH)) {
988 ERR_RETURN(strm, Z_STREAM_ERROR);
989 }
990 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
991
992 s->strm = strm; /* just in case */
993 old_flush = s->last_flush;
994 s->last_flush = flush;
995
996 /* Write the zlib header */
997 if (s->status == INIT_STATE) {
998
999 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1000 uInt level_flags = (s->level-1) >> 1;
1001
1002 if (level_flags > 3) level_flags = 3;
1003 header |= (level_flags << 6);
1004 if (s->strstart != 0) header |= PRESET_DICT;
1005 header += 31 - (header % 31);
1006
1007 s->status = BUSY_STATE;
1008 putShortMSB(s, header);
1009
1010 /* Save the adler32 of the preset dictionary: */
1011 if (s->strstart != 0) {
1012 putShortMSB(s, (uInt)(strm->adler >> 16));
1013 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1014 }
1015 strm->adler = 1L;
1016 }
1017
1018 /* Flush as much pending output as possible */
1019 if (s->pending != 0) {
1020 flush_pending(strm);
1021 if (strm->avail_out == 0) {
1022 /* Since avail_out is 0, deflate will be called again with
1023 * more output space, but possibly with both pending and
1024 * avail_in equal to zero. There won't be anything to do,
1025 * but this is not an error situation so make sure we
1026 * return OK instead of BUF_ERROR at next call of deflate:
1027 */
1028 s->last_flush = -1;
1029 return Z_OK;
1030 }
1031
1032 /* Make sure there is something to do and avoid duplicate consecutive
1033 * flushes. For repeated and useless calls with Z_FINISH, we keep
1034 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1035 */
1036 } else if (strm->avail_in == 0 && flush <= old_flush &&
1037 flush != Z_FINISH) {
1038 ERR_RETURN(strm, Z_BUF_ERROR);
1039 }
1040
1041 /* User must not provide more input after the first FINISH: */
1042 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1043 ERR_RETURN(strm, Z_BUF_ERROR);
1044 }
1045
1046 /* Start a new block or continue the current one.
1047 */
1048 if (strm->avail_in != 0 || s->lookahead != 0 ||
1049 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1050 block_state bstate;
1051
1052 bstate = (*(configuration_table[s->level].func))(s, flush);
1053
1054 if (bstate == finish_started || bstate == finish_done) {
1055 s->status = FINISH_STATE;
1056 }
1057 if (bstate == need_more || bstate == finish_started) {
1058 if (strm->avail_out == 0) {
1059 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1060 }
1061 return Z_OK;
1062 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1063 * of deflate should use the same flush parameter to make sure
1064 * that the flush is complete. So we don't have to output an
1065 * empty block here, this will be done at next call. This also
1066 * ensures that for a very small output buffer, we emit at most
1067 * one empty block.
1068 */
1069 }
1070 if (bstate == block_done) {
1071 if (flush == Z_PARTIAL_FLUSH) {
1072 _tr_align(s);
1073 } else if (flush == Z_PACKET_FLUSH) {
1074 /* Output just the 3-bit `stored' block type value,
1075 but not a zero length. */
1076 _tr_stored_type_only(s);
1077 } else { /* FULL_FLUSH or SYNC_FLUSH */
60233e58 1078 _tr_stored_block(s, NULL, 0L, 0);
984263bc
MD
1079 /* For a full flush, this empty block will be recognized
1080 * as a special marker by inflate_sync().
1081 */
1082 if (flush == Z_FULL_FLUSH) {
1083 CLEAR_HASH(s); /* forget history */
1084 }
1085 }
1086 flush_pending(strm);
1087 if (strm->avail_out == 0) {
1088 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1089 return Z_OK;
1090 }
1091 }
1092 }
1093 Assert(strm->avail_out > 0, "bug2");
1094
1095 if (flush != Z_FINISH) return Z_OK;
1096 if (s->noheader) return Z_STREAM_END;
1097
1098 /* Write the zlib trailer (adler32) */
1099 putShortMSB(s, (uInt)(strm->adler >> 16));
1100 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1101 flush_pending(strm);
1102 /* If avail_out is zero, the application will call deflate again
1103 * to flush the rest.
1104 */
1105 s->noheader = -1; /* write the trailer only once! */
1106 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1107}
1108
1109/* ========================================================================= */
bf8c57c6
SW
1110int
1111deflateEnd(z_streamp strm)
984263bc
MD
1112{
1113 int status;
1114 deflate_state *s;
1115
1116 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1117 s = (deflate_state *) strm->state;
1118
1119 status = s->status;
1120 if (status != INIT_STATE && status != BUSY_STATE &&
1121 status != FINISH_STATE) {
1122 return Z_STREAM_ERROR;
1123 }
1124
1125 /* Deallocate in reverse order of allocations: */
1126 TRY_FREE(strm, s->pending_buf);
1127 TRY_FREE(strm, s->head);
1128 TRY_FREE(strm, s->prev);
1129 TRY_FREE(strm, s->window);
1130
1131 ZFREE(strm, s);
1132 strm->state = Z_NULL;
1133
1134 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1135}
1136
1137/* =========================================================================
1138 * Copy the source state to the destination state.
1139 */
bf8c57c6
SW
1140int
1141deflateCopy(z_streamp dest, z_streamp source)
984263bc
MD
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 */
bf8c57c6
SW
1191int
1192deflateOutputPending(z_streamp strm)
984263bc
MD
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 */
bf8c57c6
SW
1206local int
1207read_buf(z_streamp strm, charf *buf, unsigned size)
984263bc
MD
1208{
1209 unsigned len = strm->avail_in;
1210
1211 if (len > size) len = size;
1212 if (len == 0) return 0;
1213
1214 strm->avail_in -= len;
1215
1216 if (!((deflate_state *)(strm->state))->noheader) {
1217 strm->adler = adler32(strm->adler, strm->next_in, len);
1218 }
1219 zmemcpy(buf, strm->next_in, len);
1220 strm->next_in += len;
1221 strm->total_in += len;
1222
1223 return (int)len;
1224}
1225
1226/* ===========================================================================
1227 * Initialize the "longest match" routines for a new zlib stream
1228 */
bf8c57c6
SW
1229local void
1230lm_init(deflate_state *s)
984263bc
MD
1231{
1232 s->window_size = (ulg)2L*s->w_size;
1233
1234 CLEAR_HASH(s);
1235
1236 /* Set the default configuration parameters:
1237 */
1238 s->max_lazy_match = configuration_table[s->level].max_lazy;
1239 s->good_match = configuration_table[s->level].good_length;
1240 s->nice_match = configuration_table[s->level].nice_length;
1241 s->max_chain_length = configuration_table[s->level].max_chain;
1242
1243 s->strstart = 0;
1244 s->block_start = 0L;
1245 s->lookahead = 0;
1246 s->match_length = s->prev_length = MIN_MATCH-1;
1247 s->match_available = 0;
1248 s->ins_h = 0;
1249#ifdef ASMV
1250 match_init(); /* initialize the asm code */
1251#endif
1252}
1253
1254/* ===========================================================================
1255 * Set match_start to the longest match starting at the given string and
1256 * return its length. Matches shorter or equal to prev_length are discarded,
1257 * in which case the result is equal to prev_length and match_start is
1258 * garbage.
1259 * IN assertions: cur_match is the head of the hash chain for the current
1260 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1261 * OUT assertion: the match length is not greater than s->lookahead.
bf8c57c6
SW
1262 *
1263 * Parameters:
1264 * cur_match: current match
984263bc
MD
1265 */
1266#ifndef ASMV
1267/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1268 * match.S. The code will be functionally equivalent.
1269 */
bf8c57c6
SW
1270local uInt
1271longest_match(deflate_state *s, IPos cur_match)
984263bc
MD
1272{
1273 unsigned chain_length = s->max_chain_length;/* max hash chain length */
82ed7fc2
RG
1274 Bytef *scan = s->window + s->strstart; /* current string */
1275 Bytef *match; /* matched string */
1276 int len; /* length of current match */
984263bc
MD
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 */
82ed7fc2
RG
1291 Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1292 ush scan_start = *(ushf*)scan;
1293 ush scan_end = *(ushf*)(scan+best_len-1);
984263bc 1294#else
82ed7fc2
RG
1295 Bytef *strend = s->window + s->strstart + MAX_MATCH;
1296 Byte scan_end1 = scan[best_len-1];
1297 Byte scan_end = scan[best_len];
984263bc
MD
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 */
bf8c57c6
SW
1412local void
1413check_match(deflate_state *s, IPos start, IPos match, int length)
984263bc
MD
1414{
1415 /* check that the match is indeed a match */
1416 if (zmemcmp((charf *)s->window + match,
1417 (charf *)s->window + start, length) != EQUAL) {
1418 fprintf(stderr, " start %u, match %u, length %d\n",
1419 start, match, length);
1420 do {
1421 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1422 } while (--length != 0);
1423 z_error("invalid match");
1424 }
1425 if (z_verbose > 1) {
1426 fprintf(stderr,"\\[%d,%d]", start-match, length);
1427 do { putc(s->window[start++], stderr); } while (--length != 0);
1428 }
1429}
1430#else
1431# define check_match(s, start, match, length)
1432#endif
1433
1434/* ===========================================================================
1435 * Fill the window when the lookahead becomes insufficient.
1436 * Updates strstart and lookahead.
1437 *
1438 * IN assertion: lookahead < MIN_LOOKAHEAD
1439 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1440 * At least one byte has been read, or avail_in == 0; reads are
1441 * performed for at least two bytes (required for the zip translate_eol
1442 * option -- not supported here).
1443 */
bf8c57c6
SW
1444local void
1445fill_window(deflate_state *s)
984263bc 1446{
82ed7fc2
RG
1447 unsigned n, m;
1448 Posf *p;
984263bc
MD
1449 unsigned more; /* Amount of free space at the end of the window. */
1450 uInt wsize = s->w_size;
1451
1452 do {
1453 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1454
1455 /* Deal with !@#$% 64K limit: */
1456 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1457 more = wsize;
1458
1459 } else if (more == (unsigned)(-1)) {
1460 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1461 * and lookahead == 1 (input done one byte at time)
1462 */
1463 more--;
1464
1465 /* If the window is almost full and there is insufficient lookahead,
1466 * move the upper half to the lower one to make room in the upper half.
1467 */
1468 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1469
1470 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1471 (unsigned)wsize);
1472 s->match_start -= wsize;
1473 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1474 s->block_start -= (long) wsize;
1475
1476 /* Slide the hash table (could be avoided with 32 bit values
1477 at the expense of memory usage). We slide even when level == 0
1478 to keep the hash table consistent if we switch back to level > 0
1479 later. (Using level 0 permanently is not an optimal usage of
1480 zlib, so we don't care about this pathological case.)
1481 */
1482 n = s->hash_size;
1483 p = &s->head[n];
1484 do {
1485 m = *--p;
1486 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1487 } while (--n);
1488
1489 n = wsize;
1490 p = &s->prev[n];
1491 do {
1492 m = *--p;
1493 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1494 /* If n is not on any hash chain, prev[n] is garbage but
1495 * its value will never be used.
1496 */
1497 } while (--n);
1498 more += wsize;
1499 }
1500 if (s->strm->avail_in == 0) return;
1501
1502 /* If there was no sliding:
1503 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1504 * more == window_size - lookahead - strstart
1505 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1506 * => more >= window_size - 2*WSIZE + 2
1507 * In the BIG_MEM or MMAP case (not yet supported),
1508 * window_size == input_size + MIN_LOOKAHEAD &&
1509 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1510 * Otherwise, window_size == 2*WSIZE so more >= 2.
1511 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1512 */
1513 Assert(more >= 2, "more < 2");
1514
1515 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1516 more);
1517 s->lookahead += n;
1518
1519 /* Initialize the hash value now that we have some input: */
1520 if (s->lookahead >= MIN_MATCH) {
1521 s->ins_h = s->window[s->strstart];
1522 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1523#if MIN_MATCH != 3
1524 Call UPDATE_HASH() MIN_MATCH-3 more times
1525#endif
1526 }
1527 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1528 * but this is not important since only literal bytes will be emitted.
1529 */
1530
1531 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1532}
1533
1534/* ===========================================================================
1535 * Flush the current block, with given end-of-file flag.
1536 * IN assertion: strstart is set to the end of the current match.
1537 */
1538#define FLUSH_BLOCK_ONLY(s, eof) { \
1539 _tr_flush_block(s, (s->block_start >= 0L ? \
1540 (charf *)&s->window[(unsigned)s->block_start] : \
1541 (charf *)Z_NULL), \
1542 (ulg)((long)s->strstart - s->block_start), \
1543 (eof)); \
1544 s->block_start = s->strstart; \
1545 flush_pending(s->strm); \
1546 Tracev((stderr,"[FLUSH]")); \
1547}
1548
1549/* Same but force premature exit if necessary. */
1550#define FLUSH_BLOCK(s, eof) { \
1551 FLUSH_BLOCK_ONLY(s, eof); \
1552 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1553}
1554
1555/* ===========================================================================
1556 * Copy without compression as much as possible from the input stream, return
1557 * the current block state.
1558 * This function does not insert new strings in the dictionary since
1559 * uncompressible data is probably not useful. This function is used
1560 * only for the level=0 compression option.
1561 * NOTE: this function should be optimized to avoid extra copying from
1562 * window to pending_buf.
1563 */
bf8c57c6
SW
1564local block_state
1565deflate_stored(deflate_state *s, int flush)
984263bc
MD
1566{
1567 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1568 * to pending_buf_size, and each stored block has a 5 byte header:
1569 */
1570 ulg max_block_size = 0xffff;
1571 ulg max_start;
1572
1573 if (max_block_size > s->pending_buf_size - 5) {
1574 max_block_size = s->pending_buf_size - 5;
1575 }
1576
1577 /* Copy as much as possible from input to output: */
1578 for (;;) {
1579 /* Fill the window as much as possible: */
1580 if (s->lookahead <= 1) {
1581
1582 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1583 s->block_start >= (long)s->w_size, "slide too late");
1584
1585 fill_window(s);
1586 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1587
1588 if (s->lookahead == 0) break; /* flush the current block */
1589 }
1590 Assert(s->block_start >= 0L, "block gone");
1591
1592 s->strstart += s->lookahead;
1593 s->lookahead = 0;
1594
1595 /* Emit a stored block if pending_buf will be full: */
f23061d4 1596 max_start = s->block_start + max_block_size;
984263bc
MD
1597 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1598 /* strstart == 0 is possible when wraparound on 16-bit machine */
1599 s->lookahead = (uInt)(s->strstart - max_start);
1600 s->strstart = (uInt)max_start;
1601 FLUSH_BLOCK(s, 0);
1602 }
1603 /* Flush if we may have to slide, otherwise block_start may become
1604 * negative and the data will be gone:
1605 */
1606 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1607 FLUSH_BLOCK(s, 0);
1608 }
1609 }
1610 FLUSH_BLOCK(s, flush == Z_FINISH);
1611 return flush == Z_FINISH ? finish_done : block_done;
1612}
1613
1614/* ===========================================================================
1615 * Compress as much as possible from the input stream, return the current
1616 * block state.
1617 * This function does not perform lazy evaluation of matches and inserts
1618 * new strings in the dictionary only for unmatched strings or for short
1619 * matches. It is used only for the fast compression options.
1620 */
bf8c57c6
SW
1621local block_state
1622deflate_fast(deflate_state *s, int flush)
984263bc
MD
1623{
1624 IPos hash_head = NIL; /* head of the hash chain */
1625 int bflush; /* set if current block must be flushed */
1626
1627 for (;;) {
1628 /* Make sure that we always have enough lookahead, except
1629 * at the end of the input file. We need MAX_MATCH bytes
1630 * for the next match, plus MIN_MATCH bytes to insert the
1631 * string following the next match.
1632 */
1633 if (s->lookahead < MIN_LOOKAHEAD) {
1634 fill_window(s);
1635 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1636 return need_more;
1637 }
1638 if (s->lookahead == 0) break; /* flush the current block */
1639 }
1640
1641 /* Insert the string window[strstart .. strstart+2] in the
1642 * dictionary, and set hash_head to the head of the hash chain:
1643 */
1644 if (s->lookahead >= MIN_MATCH) {
1645 INSERT_STRING(s, s->strstart, hash_head);
1646 }
1647
1648 /* Find the longest match, discarding those <= prev_length.
1649 * At this point we have always match_length < MIN_MATCH
1650 */
1651 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1652 /* To simplify the code, we prevent matches with the string
1653 * of window index 0 (in particular we have to avoid a match
1654 * of the string with itself at the start of the input file).
1655 */
1656 if (s->strategy != Z_HUFFMAN_ONLY) {
1657 s->match_length = longest_match (s, hash_head);
1658 }
1659 /* longest_match() sets match_start */
1660 }
1661 if (s->match_length >= MIN_MATCH) {
1662 check_match(s, s->strstart, s->match_start, s->match_length);
1663
1664 bflush = _tr_tally(s, s->strstart - s->match_start,
1665 s->match_length - MIN_MATCH);
1666
1667 s->lookahead -= s->match_length;
1668
1669 /* Insert new strings in the hash table only if the match length
1670 * is not too large. This saves time but degrades compression.
1671 */
1672 if (s->match_length <= s->max_insert_length &&
1673 s->lookahead >= MIN_MATCH) {
1674 s->match_length--; /* string at strstart already in hash table */
1675 do {
1676 s->strstart++;
1677 INSERT_STRING(s, s->strstart, hash_head);
1678 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1679 * always MIN_MATCH bytes ahead.
1680 */
1681 } while (--s->match_length != 0);
1682 s->strstart++;
1683 } else {
1684 s->strstart += s->match_length;
1685 s->match_length = 0;
1686 s->ins_h = s->window[s->strstart];
1687 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1688#if MIN_MATCH != 3
1689 Call UPDATE_HASH() MIN_MATCH-3 more times
1690#endif
1691 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1692 * matter since it will be recomputed at next deflate call.
1693 */
1694 }
1695 } else {
1696 /* No match, output a literal byte */
1697 Tracevv((stderr,"%c", s->window[s->strstart]));
1698 bflush = _tr_tally (s, 0, s->window[s->strstart]);
1699 s->lookahead--;
1700 s->strstart++;
1701 }
1702 if (bflush) FLUSH_BLOCK(s, 0);
1703 }
1704 FLUSH_BLOCK(s, flush == Z_FINISH);
1705 return flush == Z_FINISH ? finish_done : block_done;
1706}
1707
1708/* ===========================================================================
1709 * Same as above, but achieves better compression. We use a lazy
1710 * evaluation for matches: a match is finally adopted only if there is
1711 * no better match at the next window position.
1712 */
bf8c57c6
SW
1713local block_state
1714deflate_slow(deflate_state *s, int flush)
984263bc
MD
1715{
1716 IPos hash_head = NIL; /* head of hash chain */
1717 int bflush; /* set if current block must be flushed */
1718
1719 /* Process the input block. */
1720 for (;;) {
1721 /* Make sure that we always have enough lookahead, except
1722 * at the end of the input file. We need MAX_MATCH bytes
1723 * for the next match, plus MIN_MATCH bytes to insert the
1724 * string following the next match.
1725 */
1726 if (s->lookahead < MIN_LOOKAHEAD) {
1727 fill_window(s);
1728 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1729 return need_more;
1730 }
1731 if (s->lookahead == 0) break; /* flush the current block */
1732 }
1733
1734 /* Insert the string window[strstart .. strstart+2] in the
1735 * dictionary, and set hash_head to the head of the hash chain:
1736 */
1737 if (s->lookahead >= MIN_MATCH) {
1738 INSERT_STRING(s, s->strstart, hash_head);
1739 }
1740
1741 /* Find the longest match, discarding those <= prev_length.
1742 */
1743 s->prev_length = s->match_length, s->prev_match = s->match_start;
1744 s->match_length = MIN_MATCH-1;
1745
1746 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1747 s->strstart - hash_head <= MAX_DIST(s)) {
1748 /* To simplify the code, we prevent matches with the string
1749 * of window index 0 (in particular we have to avoid a match
1750 * of the string with itself at the start of the input file).
1751 */
1752 if (s->strategy != Z_HUFFMAN_ONLY) {
1753 s->match_length = longest_match (s, hash_head);
1754 }
1755 /* longest_match() sets match_start */
1756
1757 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1758 (s->match_length == MIN_MATCH &&
1759 s->strstart - s->match_start > TOO_FAR))) {
1760
1761 /* If prev_match is also MIN_MATCH, match_start is garbage
1762 * but we will ignore the current match anyway.
1763 */
1764 s->match_length = MIN_MATCH-1;
1765 }
1766 }
1767 /* If there was a match at the previous step and the current
1768 * match is not better, output the previous match:
1769 */
1770 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1771 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1772 /* Do not insert strings in hash table beyond this. */
1773
1774 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1775
1776 bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
1777 s->prev_length - MIN_MATCH);
1778
1779 /* Insert in hash table all strings up to the end of the match.
1780 * strstart-1 and strstart are already inserted. If there is not
1781 * enough lookahead, the last two strings are not inserted in
1782 * the hash table.
1783 */
1784 s->lookahead -= s->prev_length-1;
1785 s->prev_length -= 2;
1786 do {
1787 if (++s->strstart <= max_insert) {
1788 INSERT_STRING(s, s->strstart, hash_head);
1789 }
1790 } while (--s->prev_length != 0);
1791 s->match_available = 0;
1792 s->match_length = MIN_MATCH-1;
1793 s->strstart++;
1794
1795 if (bflush) FLUSH_BLOCK(s, 0);
1796
1797 } else if (s->match_available) {
1798 /* If there was no match at the previous position, output a
1799 * single literal. If there was a match but the current match
1800 * is longer, truncate the previous match to a single literal.
1801 */
1802 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1803 if (_tr_tally (s, 0, s->window[s->strstart-1])) {
1804 FLUSH_BLOCK_ONLY(s, 0);
1805 }
1806 s->strstart++;
1807 s->lookahead--;
1808 if (s->strm->avail_out == 0) return need_more;
1809 } else {
1810 /* There is no previous match to compare with, wait for
1811 * the next step to decide.
1812 */
1813 s->match_available = 1;
1814 s->strstart++;
1815 s->lookahead--;
1816 }
1817 }
1818 Assert (flush != Z_NO_FLUSH, "no flush?");
1819 if (s->match_available) {
1820 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1821 _tr_tally (s, 0, s->window[s->strstart-1]);
1822 s->match_available = 0;
1823 }
1824 FLUSH_BLOCK(s, flush == Z_FINISH);
1825 return flush == Z_FINISH ? finish_done : block_done;
1826}
1827/* --- deflate.c */
1828
1829/* +++ trees.c */
1830/* trees.c -- output deflated data using Huffman coding
1831 * Copyright (C) 1995-1996 Jean-loup Gailly
1832 * For conditions of distribution and use, see copyright notice in zlib.h
1833 */
1834
1835/*
1836 * ALGORITHM
1837 *
1838 * The "deflation" process uses several Huffman trees. The more
1839 * common source values are represented by shorter bit sequences.
1840 *
1841 * Each code tree is stored in a compressed form which is itself
1842 * a Huffman encoding of the lengths of all the code strings (in
1843 * ascending order by source values). The actual code strings are
1844 * reconstructed from the lengths in the inflate process, as described
1845 * in the deflate specification.
1846 *
1847 * REFERENCES
1848 *
1849 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1850 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1851 *
1852 * Storer, James A.
1853 * Data Compression: Methods and Theory, pp. 49-50.
1854 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1855 *
1856 * Sedgewick, R.
1857 * Algorithms, p290.
1858 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1859 */
1860
1861/* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
1862
1863/* #include "deflate.h" */
1864
1865#ifdef DEBUG_ZLIB
1866# include <ctype.h>
1867#endif
1868
1869/* ===========================================================================
1870 * Constants
1871 */
1872
1873#define MAX_BL_BITS 7
1874/* Bit length codes must not exceed MAX_BL_BITS bits */
1875
1876#define END_BLOCK 256
1877/* end of block literal code */
1878
1879#define REP_3_6 16
1880/* repeat previous bit length 3-6 times (2 bits of repeat count) */
1881
1882#define REPZ_3_10 17
1883/* repeat a zero length 3-10 times (3 bits of repeat count) */
1884
1885#define REPZ_11_138 18
1886/* repeat a zero length 11-138 times (7 bits of repeat count) */
1887
1888local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1889 = {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};
1890
1891local int extra_dbits[D_CODES] /* extra bits for each distance code */
1892 = {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};
1893
1894local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1895 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1896
1897local uch bl_order[BL_CODES]
1898 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1899/* The lengths of the bit length codes are sent in order of decreasing
1900 * probability, to avoid transmitting the lengths for unused bit length codes.
1901 */
1902
1903#define Buf_size (8 * 2*sizeof(char))
1904/* Number of bits used within bi_buf. (bi_buf might be implemented on
1905 * more than 16 bits on some systems.)
1906 */
1907
1908/* ===========================================================================
1909 * Local data. These are initialized only once.
1910 */
1911
1912local ct_data static_ltree[L_CODES+2];
1913/* The static literal tree. Since the bit lengths are imposed, there is no
1914 * need for the L_CODES extra codes used during heap construction. However
1915 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
1916 * below).
1917 */
1918
1919local ct_data static_dtree[D_CODES];
1920/* The static distance tree. (Actually a trivial tree since all codes use
1921 * 5 bits.)
1922 */
1923
1924local uch dist_code[512];
1925/* distance codes. The first 256 values correspond to the distances
1926 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1927 * the 15 bit distances.
1928 */
1929
1930local uch length_code[MAX_MATCH-MIN_MATCH+1];
1931/* length code for each normalized match length (0 == MIN_MATCH) */
1932
1933local int base_length[LENGTH_CODES];
1934/* First normalized length for each code (0 = MIN_MATCH) */
1935
1936local int base_dist[D_CODES];
1937/* First normalized distance for each code (0 = distance of 1) */
1938
1939struct static_tree_desc_s {
1940 ct_data *static_tree; /* static tree or NULL */
1941 intf *extra_bits; /* extra bits for each code or NULL */
1942 int extra_base; /* base index for extra_bits */
1943 int elems; /* max number of elements in the tree */
1944 int max_length; /* max bit length for the codes */
1945};
1946
1947local static_tree_desc static_l_desc =
1948{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1949
1950local static_tree_desc static_d_desc =
1951{static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1952
1953local static_tree_desc static_bl_desc =
60233e58 1954{NULL, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
984263bc
MD
1955
1956/* ===========================================================================
1957 * Local (static) routines in this file.
1958 */
1959
1960local void tr_static_init OF((void));
1961local void init_block OF((deflate_state *s));
1962local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1963local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1964local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1965local void build_tree OF((deflate_state *s, tree_desc *desc));
1966local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1967local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1968local int build_bl_tree OF((deflate_state *s));
1969local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1970 int blcodes));
1971local void compress_block OF((deflate_state *s, ct_data *ltree,
1972 ct_data *dtree));
1973local void set_data_type OF((deflate_state *s));
1974local unsigned bi_reverse OF((unsigned value, int length));
1975local void bi_windup OF((deflate_state *s));
1976local void bi_flush OF((deflate_state *s));
1977local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1978 int header));
1979
1980#ifndef DEBUG_ZLIB
1981# define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1982 /* Send a code of the given tree. c and tree must not have side effects */
1983
1984#else /* DEBUG_ZLIB */
1985# define send_code(s, c, tree) \
1986 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
1987 send_bits(s, tree[c].Code, tree[c].Len); }
1988#endif
1989
1990#define d_code(dist) \
1991 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1992/* Mapping from a distance to a distance code. dist is the distance - 1 and
1993 * must not have side effects. dist_code[256] and dist_code[257] are never
1994 * used.
1995 */
1996
1997/* ===========================================================================
1998 * Output a short LSB first on the stream.
1999 * IN assertion: there is enough room in pendingBuf.
2000 */
2001#define put_short(s, w) { \
2002 put_byte(s, (uch)((w) & 0xff)); \
2003 put_byte(s, (uch)((ush)(w) >> 8)); \
2004}
2005
2006/* ===========================================================================
2007 * Send a value on a given number of bits.
2008 * IN assertion: length <= 16 and value fits in length bits.
bf8c57c6
SW
2009 *
2010 * Parameters:
2011 * value: value to send
2012 * length: number of bits
984263bc
MD
2013 */
2014#ifdef DEBUG_ZLIB
2015local void send_bits OF((deflate_state *s, int value, int length));
2016
bf8c57c6
SW
2017local void
2018send_bits(deflate_state *s, int value, int length)
984263bc
MD
2019{
2020 Tracevv((stderr," l %2d v %4x ", length, value));
2021 Assert(length > 0 && length <= 15, "invalid length");
2022 s->bits_sent += (ulg)length;
2023
2024 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2025 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2026 * unused bits in value.
2027 */
2028 if (s->bi_valid > (int)Buf_size - length) {
2029 s->bi_buf |= (value << s->bi_valid);
2030 put_short(s, s->bi_buf);
2031 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2032 s->bi_valid += length - Buf_size;
2033 } else {
2034 s->bi_buf |= value << s->bi_valid;
2035 s->bi_valid += length;
2036 }
2037}
2038#else /* !DEBUG_ZLIB */
2039
2040#define send_bits(s, value, length) \
2041{ int len = length;\
2042 if (s->bi_valid > (int)Buf_size - len) {\
2043 int val = value;\
2044 s->bi_buf |= (val << s->bi_valid);\
2045 put_short(s, s->bi_buf);\
2046 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2047 s->bi_valid += len - Buf_size;\
2048 } else {\
2049 s->bi_buf |= (value) << s->bi_valid;\
2050 s->bi_valid += len;\
2051 }\
2052}
2053#endif /* DEBUG_ZLIB */
2054
984263bc
MD
2055/* the arguments must not have side effects */
2056
2057/* ===========================================================================
2058 * Initialize the various 'constant' tables. In a multi-threaded environment,
2059 * this function may be called by two threads concurrently, but this is
2060 * harmless since both invocations do exactly the same thing.
2061 */
bf8c57c6
SW
2062local void
2063tr_static_init(void)
984263bc
MD
2064{
2065 static int static_init_done = 0;
2066 int n; /* iterates over tree elements */
2067 int bits; /* bit counter */
2068 int length; /* length value */
2069 int code; /* code value */
2070 int dist; /* distance index */
2071 ush bl_count[MAX_BITS+1];
2072 /* number of codes at each bit length for an optimal tree */
2073
2074 if (static_init_done) return;
2075
2076 /* Initialize the mapping length (0..255) -> length code (0..28) */
2077 length = 0;
2078 for (code = 0; code < LENGTH_CODES-1; code++) {
2079 base_length[code] = length;
2080 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2081 length_code[length++] = (uch)code;
2082 }
2083 }
2084 Assert (length == 256, "tr_static_init: length != 256");
2085 /* Note that the length 255 (match length 258) can be represented
2086 * in two different ways: code 284 + 5 bits or code 285, so we
2087 * overwrite length_code[255] to use the best encoding:
2088 */
2089 length_code[length-1] = (uch)code;
2090
2091 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2092 dist = 0;
2093 for (code = 0 ; code < 16; code++) {
2094 base_dist[code] = dist;
2095 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2096 dist_code[dist++] = (uch)code;
2097 }
2098 }
2099 Assert (dist == 256, "tr_static_init: dist != 256");
2100 dist >>= 7; /* from now on, all distances are divided by 128 */
2101 for ( ; code < D_CODES; code++) {
2102 base_dist[code] = dist << 7;
2103 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2104 dist_code[256 + dist++] = (uch)code;
2105 }
2106 }
2107 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2108
2109 /* Construct the codes of the static literal tree */
2110 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2111 n = 0;
2112 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2113 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2114 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2115 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2116 /* Codes 286 and 287 do not exist, but we must include them in the
2117 * tree construction to get a canonical Huffman tree (longest code
2118 * all ones)
2119 */
2120 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2121
2122 /* The static distance tree is trivial: */
2123 for (n = 0; n < D_CODES; n++) {
2124 static_dtree[n].Len = 5;
2125 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2126 }
2127 static_init_done = 1;
2128}
2129
2130/* ===========================================================================
2131 * Initialize the tree data structures for a new zlib stream.
2132 */
bf8c57c6
SW
2133void
2134_tr_init(deflate_state *s)
984263bc
MD
2135{
2136 tr_static_init();
2137
2138 s->compressed_len = 0L;
2139
2140 s->l_desc.dyn_tree = s->dyn_ltree;
2141 s->l_desc.stat_desc = &static_l_desc;
2142
2143 s->d_desc.dyn_tree = s->dyn_dtree;
2144 s->d_desc.stat_desc = &static_d_desc;
2145
2146 s->bl_desc.dyn_tree = s->bl_tree;
2147 s->bl_desc.stat_desc = &static_bl_desc;
2148
2149 s->bi_buf = 0;
2150 s->bi_valid = 0;
2151 s->last_eob_len = 8; /* enough lookahead for inflate */
2152#ifdef DEBUG_ZLIB
2153 s->bits_sent = 0L;
2154#endif
2155
2156 /* Initialize the first block of the first file: */
2157 init_block(s);
2158}
2159
2160/* ===========================================================================
2161 * Initialize a new block.
2162 */
bf8c57c6
SW
2163local void
2164init_block(deflate_state *s)
984263bc
MD
2165{
2166 int n; /* iterates over tree elements */
2167
2168 /* Initialize the trees. */
2169 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2170 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2171 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2172
2173 s->dyn_ltree[END_BLOCK].Freq = 1;
2174 s->opt_len = s->static_len = 0L;
2175 s->last_lit = s->matches = 0;
2176}
2177
2178#define SMALLEST 1
2179/* Index within the heap array of least frequent node in the Huffman tree */
2180
2181
2182/* ===========================================================================
2183 * Remove the smallest element from the heap and recreate the heap with
2184 * one less element. Updates heap and heap_len.
2185 */
2186#define pqremove(s, tree, top) \
2187{\
2188 top = s->heap[SMALLEST]; \
2189 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2190 pqdownheap(s, tree, SMALLEST); \
2191}
2192
2193/* ===========================================================================
2194 * Compares to subtrees, using the tree depth as tie breaker when
2195 * the subtrees have equal frequency. This minimizes the worst case length.
2196 */
2197#define smaller(tree, n, m, depth) \
2198 (tree[n].Freq < tree[m].Freq || \
2199 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2200
2201/* ===========================================================================
2202 * Restore the heap property by moving down the tree starting at node k,
2203 * exchanging a node with the smallest of its two sons if necessary, stopping
2204 * when the heap property is re-established (each father smaller than its
2205 * two sons).
bf8c57c6
SW
2206 *
2207 * Parameters:
2208 * tree: the tree to restore
2209 * k: node to move down
984263bc 2210 */
bf8c57c6
SW
2211local void
2212pqdownheap(deflate_state *s, ct_data *tree, int k)
984263bc
MD
2213{
2214 int v = s->heap[k];
2215 int j = k << 1; /* left son of k */
2216 while (j <= s->heap_len) {
2217 /* Set j to the smallest of the two sons: */
2218 if (j < s->heap_len &&
2219 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2220 j++;
2221 }
2222 /* Exit if v is smaller than both sons */
2223 if (smaller(tree, v, s->heap[j], s->depth)) break;
2224
2225 /* Exchange v with the smallest son */
2226 s->heap[k] = s->heap[j]; k = j;
2227
2228 /* And continue down the tree, setting j to the left son of k */
2229 j <<= 1;
2230 }
2231 s->heap[k] = v;
2232}
2233
2234/* ===========================================================================
2235 * Compute the optimal bit lengths for a tree and update the total bit length
2236 * for the current block.
2237 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2238 * above are the tree nodes sorted by increasing frequency.
2239 * OUT assertions: the field len is set to the optimal bit length, the
2240 * array bl_count contains the frequencies for each bit length.
2241 * The length opt_len is updated; static_len is also updated if stree is
2242 * not null.
bf8c57c6
SW
2243 *
2244 * Parameters:
2245 * desc: the tree descriptor
984263bc 2246 */
bf8c57c6
SW
2247local void
2248gen_bitlen(deflate_state *s, tree_desc *desc)
984263bc
MD
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.
bf8c57c6
SW
2332 *
2333 * Parameters:
2334 * tree: the tree to decorate
2335 * max_code: largest code with non zero frequency
2336 * bl_count: number of codes at each bit length
984263bc 2337 */
bf8c57c6
SW
2338local void
2339gen_codes(ct_data *tree, int max_code, ushf *bl_count)
984263bc
MD
2340{
2341 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2342 ush code = 0; /* running code value */
2343 int bits; /* bit index */
2344 int n; /* code index */
2345
2346 /* The distribution counts are first used to generate the code values
2347 * without bit reversal.
2348 */
2349 for (bits = 1; bits <= MAX_BITS; bits++) {
2350 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2351 }
2352 /* Check that the bit counts in bl_count are consistent. The last code
2353 * must be all ones.
2354 */
2355 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2356 "inconsistent bit counts");
2357 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2358
2359 for (n = 0; n <= max_code; n++) {
2360 int len = tree[n].Len;
2361 if (len == 0) continue;
2362 /* Now reverse the bits */
2363 tree[n].Code = bi_reverse(next_code[len]++, len);
2364
2365 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2366 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2367 }
2368}
2369
2370/* ===========================================================================
2371 * Construct one Huffman tree and assigns the code bit strings and lengths.
2372 * Update the total bit length for the current block.
2373 * IN assertion: the field freq is set for all tree elements.
2374 * OUT assertions: the fields len and code are set to the optimal bit length
2375 * and corresponding code. The length opt_len is updated; static_len is
2376 * also updated if stree is not null. The field max_code is set.
bf8c57c6
SW
2377 *
2378 * Parameters:
2379 * desc: the tree descriptor
984263bc 2380 */
bf8c57c6
SW
2381local void
2382build_tree(deflate_state *s, tree_desc *desc)
984263bc
MD
2383{
2384 ct_data *tree = desc->dyn_tree;
2385 ct_data *stree = desc->stat_desc->static_tree;
2386 int elems = desc->stat_desc->elems;
2387 int n, m; /* iterate over heap elements */
2388 int max_code = -1; /* largest code with non zero frequency */
2389 int node; /* new node being created */
2390
2391 /* Construct the initial heap, with least frequent element in
2392 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2393 * heap[0] is not used.
2394 */
2395 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2396
2397 for (n = 0; n < elems; n++) {
2398 if (tree[n].Freq != 0) {
2399 s->heap[++(s->heap_len)] = max_code = n;
2400 s->depth[n] = 0;
2401 } else {
2402 tree[n].Len = 0;
2403 }
2404 }
2405
2406 /* The pkzip format requires that at least one distance code exists,
2407 * and that at least one bit should be sent even if there is only one
2408 * possible code. So to avoid special checks later on we force at least
2409 * two codes of non zero frequency.
2410 */
2411 while (s->heap_len < 2) {
2412 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2413 tree[node].Freq = 1;
2414 s->depth[node] = 0;
2415 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2416 /* node is 0 or 1 so it does not have extra bits */
2417 }
2418 desc->max_code = max_code;
2419
2420 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2421 * establish sub-heaps of increasing lengths:
2422 */
2423 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2424
2425 /* Construct the Huffman tree by repeatedly combining the least two
2426 * frequent nodes.
2427 */
2428 node = elems; /* next internal node of the tree */
2429 do {
2430 pqremove(s, tree, n); /* n = node of least frequency */
2431 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2432
2433 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2434 s->heap[--(s->heap_max)] = m;
2435
2436 /* Create a new node father of n and m */
2437 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2438 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2439 tree[n].Dad = tree[m].Dad = (ush)node;
2440#ifdef DUMP_BL_TREE
2441 if (tree == s->bl_tree) {
2442 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2443 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2444 }
2445#endif
2446 /* and insert the new node in the heap */
2447 s->heap[SMALLEST] = node++;
2448 pqdownheap(s, tree, SMALLEST);
2449
2450 } while (s->heap_len >= 2);
2451
2452 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2453
2454 /* At this point, the fields freq and dad are set. We can now
2455 * generate the bit lengths.
2456 */
2457 gen_bitlen(s, (tree_desc *)desc);
2458
2459 /* The field len is now set, we can generate the bit codes */
2460 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2461}
2462
2463/* ===========================================================================
2464 * Scan a literal or distance tree to determine the frequencies of the codes
2465 * in the bit length tree.
bf8c57c6
SW
2466 *
2467 * Parameters:
2468 * tree: the tree to be scanned
2469 * max_code: and its largest code of non zero frequency
984263bc 2470 */
bf8c57c6
SW
2471local void
2472scan_tree (deflate_state *s, ct_data *tree, int max_code)
984263bc
MD
2473{
2474 int n; /* iterates over all tree elements */
2475 int prevlen = -1; /* last emitted length */
2476 int curlen; /* length of current code */
2477 int nextlen = tree[0].Len; /* length of next code */
2478 int count = 0; /* repeat count of the current code */
2479 int max_count = 7; /* max repeat count */
2480 int min_count = 4; /* min repeat count */
2481
2482 if (nextlen == 0) max_count = 138, min_count = 3;
2483 tree[max_code+1].Len = (ush)0xffff; /* guard */
2484
2485 for (n = 0; n <= max_code; n++) {
2486 curlen = nextlen; nextlen = tree[n+1].Len;
2487 if (++count < max_count && curlen == nextlen) {
2488 continue;
2489 } else if (count < min_count) {
2490 s->bl_tree[curlen].Freq += count;
2491 } else if (curlen != 0) {
2492 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2493 s->bl_tree[REP_3_6].Freq++;
2494 } else if (count <= 10) {
2495 s->bl_tree[REPZ_3_10].Freq++;
2496 } else {
2497 s->bl_tree[REPZ_11_138].Freq++;
2498 }
2499 count = 0; prevlen = curlen;
2500 if (nextlen == 0) {
2501 max_count = 138, min_count = 3;
2502 } else if (curlen == nextlen) {
2503 max_count = 6, min_count = 3;
2504 } else {
2505 max_count = 7, min_count = 4;
2506 }
2507 }
2508}
2509
2510/* ===========================================================================
2511 * Send a literal or distance tree in compressed form, using the codes in
2512 * bl_tree.
bf8c57c6
SW
2513 *
2514 * Parameters:
2515 * tree: the tree to be scanned
2516 * max_code: and its largest code of non zero frequency
984263bc 2517 */
bf8c57c6
SW
2518local void
2519send_tree(deflate_state *s, ct_data *tree, int max_code)
984263bc
MD
2520{
2521 int n; /* iterates over all tree elements */
2522 int prevlen = -1; /* last emitted length */
2523 int curlen; /* length of current code */
2524 int nextlen = tree[0].Len; /* length of next code */
2525 int count = 0; /* repeat count of the current code */
2526 int max_count = 7; /* max repeat count */
2527 int min_count = 4; /* min repeat count */
2528
2529 /* tree[max_code+1].Len = -1; */ /* guard already set */
2530 if (nextlen == 0) max_count = 138, min_count = 3;
2531
2532 for (n = 0; n <= max_code; n++) {
2533 curlen = nextlen; nextlen = tree[n+1].Len;
2534 if (++count < max_count && curlen == nextlen) {
2535 continue;
2536 } else if (count < min_count) {
2537 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2538
2539 } else if (curlen != 0) {
2540 if (curlen != prevlen) {
2541 send_code(s, curlen, s->bl_tree); count--;
2542 }
2543 Assert(count >= 3 && count <= 6, " 3_6?");
2544 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2545
2546 } else if (count <= 10) {
2547 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2548
2549 } else {
2550 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2551 }
2552 count = 0; prevlen = curlen;
2553 if (nextlen == 0) {
2554 max_count = 138, min_count = 3;
2555 } else if (curlen == nextlen) {
2556 max_count = 6, min_count = 3;
2557 } else {
2558 max_count = 7, min_count = 4;
2559 }
2560 }
2561}
2562
2563/* ===========================================================================
2564 * Construct the Huffman tree for the bit lengths and return the index in
2565 * bl_order of the last bit length code to send.
2566 */
bf8c57c6
SW
2567local int
2568build_bl_tree(deflate_state *s)
984263bc
MD
2569{
2570 int max_blindex; /* index of last bit length code of non zero freq */
2571
2572 /* Determine the bit length frequencies for literal and distance trees */
2573 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2574 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2575
2576 /* Build the bit length tree: */
2577 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2578 /* opt_len now includes the length of the tree representations, except
2579 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2580 */
2581
2582 /* Determine the number of bit length codes to send. The pkzip format
2583 * requires that at least 4 bit length codes be sent. (appnote.txt says
2584 * 3 but the actual value used is 4.)
2585 */
2586 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2587 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2588 }
2589 /* Update opt_len to include the bit length tree and counts */
2590 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2591 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2592 s->opt_len, s->static_len));
2593
2594 return max_blindex;
2595}
2596
2597/* ===========================================================================
2598 * Send the header for a block using dynamic Huffman trees: the counts, the
2599 * lengths of the bit length codes, the literal tree and the distance tree.
2600 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
bf8c57c6
SW
2601 *
2602 * Parameters:
2603 * lcodes, dcodes, blcodes: number of codes for each tree
984263bc 2604 */
bf8c57c6
SW
2605local void
2606send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes)
984263bc
MD
2607{
2608 int rank; /* index in bl_order */
2609
2610 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2611 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2612 "too many codes");
2613 Tracev((stderr, "\nbl counts: "));
2614 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2615 send_bits(s, dcodes-1, 5);
2616 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2617 for (rank = 0; rank < blcodes; rank++) {
2618 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2619 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2620 }
2621 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2622
2623 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2624 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2625
2626 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2627 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2628}
2629
2630/* ===========================================================================
2631 * Send a stored block
bf8c57c6
SW
2632 *
2633 * Parameters:
2634 * buf: input block
2635 * stored_len: length of input block
2636 * eof: true if this is the last block for a file
984263bc 2637 */
bf8c57c6
SW
2638void
2639_tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
984263bc
MD
2640{
2641 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2642 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
2643 s->compressed_len += (stored_len + 4) << 3;
2644
2645 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2646}
2647
2648/* Send just the `stored block' type code without any length bytes or data.
2649 */
bf8c57c6
SW
2650void
2651_tr_stored_type_only(deflate_state *s)
984263bc
MD
2652{
2653 send_bits(s, (STORED_BLOCK << 1), 3);
2654 bi_windup(s);
2655 s->compressed_len = (s->compressed_len + 3) & ~7L;
2656}
2657
2658
2659/* ===========================================================================
2660 * Send one empty static block to give enough lookahead for inflate.
2661 * This takes 10 bits, of which 7 may remain in the bit buffer.
2662 * The current inflate code requires 9 bits of lookahead. If the
2663 * last two codes for the previous block (real code plus EOB) were coded
2664 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
2665 * the last real code. In this case we send two empty static blocks instead
2666 * of one. (There are no problems if the previous block is stored or fixed.)
2667 * To simplify the code, we assume the worst case of last real code encoded
2668 * on one bit only.
2669 */
bf8c57c6
SW
2670void
2671_tr_align(deflate_state *s)
984263bc
MD
2672{
2673 send_bits(s, STATIC_TREES<<1, 3);
2674 send_code(s, END_BLOCK, static_ltree);
2675 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2676 bi_flush(s);
2677 /* Of the 10 bits for the empty block, we have already sent
2678 * (10 - bi_valid) bits. The lookahead for the last real code (before
2679 * the EOB of the previous block) was thus at least one plus the length
2680 * of the EOB plus what we have just sent of the empty static block.
2681 */
2682 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
2683 send_bits(s, STATIC_TREES<<1, 3);
2684 send_code(s, END_BLOCK, static_ltree);
2685 s->compressed_len += 10L;
2686 bi_flush(s);
2687 }
2688 s->last_eob_len = 7;
2689}
2690
2691/* ===========================================================================
2692 * Determine the best encoding for the current block: dynamic trees, static
2693 * trees or store, and output the encoded block to the zip file. This function
2694 * returns the total compressed length for the file so far.
bf8c57c6
SW
2695 *
2696 * Parameters:
2697 * buf: input block, or NULL if too old
2698 * stored_len: length of input block
2699 * eof: true if this is the last block for a file
984263bc 2700 */
bf8c57c6
SW
2701ulg
2702_tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
984263bc
MD
2703{
2704 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2705 int max_blindex = 0; /* index of last bit length code of non zero freq */
2706
2707 /* Build the Huffman trees unless a stored block is forced */
2708 if (s->level > 0) {
2709
2710 /* Check if the file is ascii or binary */
2711 if (s->data_type == Z_UNKNOWN) set_data_type(s);
2712
2713 /* Construct the literal and distance trees */
2714 build_tree(s, (tree_desc *)(&(s->l_desc)));
2715 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2716 s->static_len));
2717
2718 build_tree(s, (tree_desc *)(&(s->d_desc)));
2719 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2720 s->static_len));
2721 /* At this point, opt_len and static_len are the total bit lengths of
2722 * the compressed block data, excluding the tree representations.
2723 */
2724
2725 /* Build the bit length tree for the above two trees, and get the index
2726 * in bl_order of the last bit length code to send.
2727 */
2728 max_blindex = build_bl_tree(s);
2729
2730 /* Determine the best encoding. Compute first the block length in bytes*/
2731 opt_lenb = (s->opt_len+3+7)>>3;
2732 static_lenb = (s->static_len+3+7)>>3;
2733
2734 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2735 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2736 s->last_lit));
2737
2738 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2739
2740 } else {
60233e58 2741 Assert(buf != NULL, "lost buf");
984263bc
MD
2742 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
2743 }
2744
2745 /* If compression failed and this is the first and last block,
2746 * and if the .zip file can be seeked (to rewrite the local header),
2747 * the whole file is transformed into a stored file:
2748 */
2749#ifdef STORED_FILE_OK
2750# ifdef FORCE_STORED_FILE
2751 if (eof && s->compressed_len == 0L) { /* force stored file */
2752# else
2753 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
2754# endif
2755 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
60233e58 2756 if (buf == NULL) error ("block vanished");
984263bc
MD
2757
2758 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
2759 s->compressed_len = stored_len << 3;
2760 s->method = STORED;
2761 } else
2762#endif /* STORED_FILE_OK */
2763
2764#ifdef FORCE_STORED
60233e58 2765 if (buf != NULL) { /* force stored block */
984263bc 2766#else
60233e58 2767 if (stored_len+4 <= opt_lenb && buf != NULL) {
984263bc
MD
2768 /* 4: two words for the lengths */
2769#endif
2770 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2771 * Otherwise we can't have processed more than WSIZE input bytes since
2772 * the last block flush, because compression would have been
2773 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2774 * transform a block into a stored block.
2775 */
2776 _tr_stored_block(s, buf, stored_len, eof);
2777
2778#ifdef FORCE_STATIC
2779 } else if (static_lenb >= 0) { /* force static trees */
2780#else
2781 } else if (static_lenb == opt_lenb) {
2782#endif
2783 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2784 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2785 s->compressed_len += 3 + s->static_len;
2786 } else {
2787 send_bits(s, (DYN_TREES<<1)+eof, 3);
2788 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2789 max_blindex+1);
2790 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2791 s->compressed_len += 3 + s->opt_len;
2792 }
2793 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2794 init_block(s);
2795
2796 if (eof) {
2797 bi_windup(s);
2798 s->compressed_len += 7; /* align on byte boundary */
2799 }
2800 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2801 s->compressed_len-7*eof));
2802
2803 return s->compressed_len >> 3;
2804}
2805
2806/* ===========================================================================
2807 * Save the match info and tally the frequency counts. Return true if
2808 * the current block must be flushed.
bf8c57c6
SW
2809 *
2810 * Parameters:
2811 * dist: distance of matched string
2812 * lc: match length-MIN_MATCH or unmatched char (if dist==0)
984263bc 2813 */
bf8c57c6
SW
2814int
2815_tr_tally(deflate_state *s, unsigned dist, unsigned lc)
984263bc
MD
2816{
2817 s->d_buf[s->last_lit] = (ush)dist;
2818 s->l_buf[s->last_lit++] = (uch)lc;
2819 if (dist == 0) {
2820 /* lc is the unmatched char */
2821 s->dyn_ltree[lc].Freq++;
2822 } else {
2823 s->matches++;
2824 /* Here, lc is the match length - MIN_MATCH */
2825 dist--; /* dist = match distance - 1 */
2826 Assert((ush)dist < (ush)MAX_DIST(s) &&
2827 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2828 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
2829
2830 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2831 s->dyn_dtree[d_code(dist)].Freq++;
2832 }
2833
2834 /* Try to guess if it is profitable to stop the current block here */
2835 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2836 /* Compute an upper bound for the compressed length */
2837 ulg out_length = (ulg)s->last_lit*8L;
2838 ulg in_length = (ulg)((long)s->strstart - s->block_start);
2839 int dcode;
2840 for (dcode = 0; dcode < D_CODES; dcode++) {
2841 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2842 (5L+extra_dbits[dcode]);
2843 }
2844 out_length >>= 3;
2845 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2846 s->last_lit, in_length, out_length,
2847 100L - out_length*100L/in_length));
2848 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2849 }
2850 return (s->last_lit == s->lit_bufsize-1);
2851 /* We avoid equality with lit_bufsize because of wraparound at 64K
2852 * on 16 bit machines and because stored blocks are restricted to
2853 * 64K-1 bytes.
2854 */
2855}
2856
2857/* ===========================================================================
2858 * Send the block data compressed using the given Huffman trees
bf8c57c6
SW
2859 *
2860 * Parameters:
2861 * ltree: literal tree
2862 * dtree: distance tree
984263bc 2863 */
bf8c57c6
SW
2864local void
2865compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree)
984263bc
MD
2866{
2867 unsigned dist; /* distance of matched string */
2868 int lc; /* match length or unmatched char (if dist == 0) */
2869 unsigned lx = 0; /* running index in l_buf */
2870 unsigned code; /* the code to send */
2871 int extra; /* number of extra bits to send */
2872
2873 if (s->last_lit != 0) do {
2874 dist = s->d_buf[lx];
2875 lc = s->l_buf[lx++];
2876 if (dist == 0) {
2877 send_code(s, lc, ltree); /* send a literal byte */
2878 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2879 } else {
2880 /* Here, lc is the match length - MIN_MATCH */
2881 code = length_code[lc];
2882 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2883 extra = extra_lbits[code];
2884 if (extra != 0) {
2885 lc -= base_length[code];
2886 send_bits(s, lc, extra); /* send the extra length bits */
2887 }
2888 dist--; /* dist is now the match distance - 1 */
2889 code = d_code(dist);
2890 Assert (code < D_CODES, "bad d_code");
2891
2892 send_code(s, code, dtree); /* send the distance code */
2893 extra = extra_dbits[code];
2894 if (extra != 0) {
2895 dist -= base_dist[code];
2896 send_bits(s, dist, extra); /* send the extra distance bits */
2897 }
2898 } /* literal or match pair ? */
2899
2900 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2901 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2902
2903 } while (lx < s->last_lit);
2904
2905 send_code(s, END_BLOCK, ltree);
2906 s->last_eob_len = ltree[END_BLOCK].Len;
2907}
2908
2909/* ===========================================================================
2910 * Set the data type to ASCII or BINARY, using a crude approximation:
2911 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2912 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2913 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2914 */
bf8c57c6
SW
2915local void
2916set_data_type(deflate_state *s)
984263bc
MD
2917{
2918 int n = 0;
2919 unsigned ascii_freq = 0;
2920 unsigned bin_freq = 0;
2921 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2922 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2923 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2924 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
2925}
2926
2927/* ===========================================================================
2928 * Reverse the first len bits of a code, using straightforward code (a faster
2929 * method would use a table)
2930 * IN assertion: 1 <= len <= 15
bf8c57c6
SW
2931 *
2932 * Parameters:
2933 * code: the value to invert
2934 * len: its bit length
984263bc 2935 */
bf8c57c6
SW
2936local unsigned
2937bi_reverse(unsigned code, int len)
984263bc 2938{
82ed7fc2 2939 unsigned res = 0;
984263bc
MD
2940 do {
2941 res |= code & 1;
2942 code >>= 1, res <<= 1;
2943 } while (--len > 0);
2944 return res >> 1;
2945}
2946
2947/* ===========================================================================
2948 * Flush the bit buffer, keeping at most 7 bits in it.
2949 */
bf8c57c6
SW
2950local void
2951bi_flush(deflate_state *s)
984263bc
MD
2952{
2953 if (s->bi_valid == 16) {
2954 put_short(s, s->bi_buf);
2955 s->bi_buf = 0;
2956 s->bi_valid = 0;
2957 } else if (s->bi_valid >= 8) {
2958 put_byte(s, (Byte)s->bi_buf);
2959 s->bi_buf >>= 8;
2960 s->bi_valid -= 8;
2961 }
2962}
2963
2964/* ===========================================================================
2965 * Flush the bit buffer and align the output on a byte boundary
2966 */
bf8c57c6
SW
2967local void
2968bi_windup(deflate_state *s)
984263bc
MD
2969{
2970 if (s->bi_valid > 8) {
2971 put_short(s, s->bi_buf);
2972 } else if (s->bi_valid > 0) {
2973 put_byte(s, (Byte)s->bi_buf);
2974 }
2975 s->bi_buf = 0;
2976 s->bi_valid = 0;
2977#ifdef DEBUG_ZLIB
2978 s->bits_sent = (s->bits_sent+7) & ~7;
2979#endif
2980}
2981
2982/* ===========================================================================
2983 * Copy a stored block, storing first the length and its
2984 * one's complement if requested.
bf8c57c6
SW
2985 *
2986 * Parameters:
2987 * buf: the input data
2988 * len: its length
2989 * header: true if block header must be written
984263bc 2990 */
bf8c57c6
SW
2991local void
2992copy_block(deflate_state *s, charf *buf, unsigned len, int header)
984263bc
MD
2993{
2994 bi_windup(s); /* align on byte boundary */
2995 s->last_eob_len = 8; /* enough lookahead for inflate */
2996
2997 if (header) {
2998 put_short(s, (ush)len);
2999 put_short(s, (ush)~len);
3000#ifdef DEBUG_ZLIB
3001 s->bits_sent += 2*16;
3002#endif
3003 }
3004#ifdef DEBUG_ZLIB
3005 s->bits_sent += (ulg)len<<3;
3006#endif
3007 /* bundle up the put_byte(s, *buf++) calls */
3008 zmemcpy(&s->pending_buf[s->pending], buf, len);
3009 s->pending += len;
3010}
3011/* --- trees.c */
3012
3013/* +++ inflate.c */
3014/* inflate.c -- zlib interface to inflate modules
3015 * Copyright (C) 1995-1996 Mark Adler
3016 * For conditions of distribution and use, see copyright notice in zlib.h
3017 */
3018
3019/* #include "zutil.h" */
3020
3021/* +++ infblock.h */
3022/* infblock.h -- header to use infblock.c
3023 * Copyright (C) 1995-1996 Mark Adler
3024 * For conditions of distribution and use, see copyright notice in zlib.h
3025 */
3026
3027/* WARNING: this file should *not* be used by applications. It is
3028 part of the implementation of the compression library and is
3029 subject to change. Applications should only use zlib.h.
3030 */
3031
3032struct inflate_blocks_state;
3033typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3034
3035extern inflate_blocks_statef * inflate_blocks_new OF((
3036 z_streamp z,
3037 check_func c, /* check function */
3038 uInt w)); /* window size */
3039
3040extern int inflate_blocks OF((
3041 inflate_blocks_statef *,
3042 z_streamp ,
3043 int)); /* initial return code */
3044
3045extern void inflate_blocks_reset OF((
3046 inflate_blocks_statef *,
3047 z_streamp ,
3048 uLongf *)); /* check value on output */
3049
3050extern int inflate_blocks_free OF((
3051 inflate_blocks_statef *,
3052 z_streamp ,
3053 uLongf *)); /* check value on output */
3054
3055extern void inflate_set_dictionary OF((
3056 inflate_blocks_statef *s,
3057 const Bytef *d, /* dictionary */
3058 uInt n)); /* dictionary length */
3059
3060extern int inflate_addhistory OF((
3061 inflate_blocks_statef *,
3062 z_streamp));
3063
3064extern int inflate_packet_flush OF((
3065 inflate_blocks_statef *));
3066/* --- infblock.h */
3067
3068#ifndef NO_DUMMY_DECL
3069struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3070#endif
3071
3072/* inflate private state */
3073struct internal_state {
3074
3075 /* mode */
3076 enum {
3077 METHOD, /* waiting for method byte */
3078 FLAG, /* waiting for flag byte */
3079 DICT4, /* four dictionary check bytes to go */
3080 DICT3, /* three dictionary check bytes to go */
3081 DICT2, /* two dictionary check bytes to go */
3082 DICT1, /* one dictionary check byte to go */
3083 DICT0, /* waiting for inflateSetDictionary */
3084 BLOCKS, /* decompressing blocks */
3085 CHECK4, /* four check bytes to go */
3086 CHECK3, /* three check bytes to go */
3087 CHECK2, /* two check bytes to go */
3088 CHECK1, /* one check byte to go */
3089 DONE, /* finished check, done */
3090 BAD} /* got an error--stay here */
3091 mode; /* current inflate mode */
3092
3093 /* mode dependent information */
3094 union {
3095 uInt method; /* if FLAGS, method byte */
3096 struct {
3097 uLong was; /* computed check value */
3098 uLong need; /* stream check value */
3099 } check; /* if CHECK, check values to compare */
3100 uInt marker; /* if BAD, inflateSync's marker bytes count */
3101 } sub; /* submode */
3102
3103 /* mode independent information */
3104 int nowrap; /* flag for no wrapper */
3105 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3106 inflate_blocks_statef
3107 *blocks; /* current inflate_blocks state */
3108
3109};
3110
3111
bf8c57c6
SW
3112int
3113inflateReset(z_streamp z)
984263bc
MD
3114{
3115 uLong c;
3116
3117 if (z == Z_NULL || z->state == Z_NULL)
3118 return Z_STREAM_ERROR;
3119 z->total_in = z->total_out = 0;
3120 z->msg = Z_NULL;
3121 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3122 inflate_blocks_reset(z->state->blocks, z, &c);
3123 Trace((stderr, "inflate: reset\n"));
3124 return Z_OK;
3125}
3126
3127
bf8c57c6
SW
3128int
3129inflateEnd(z_streamp z)
984263bc
MD
3130{
3131 uLong c;
3132
3133 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3134 return Z_STREAM_ERROR;
3135 if (z->state->blocks != Z_NULL)
3136 inflate_blocks_free(z->state->blocks, z, &c);
3137 ZFREE(z, z->state);
3138 z->state = Z_NULL;
3139 Trace((stderr, "inflate: end\n"));
3140 return Z_OK;
3141}
3142
3143
bf8c57c6
SW
3144int
3145inflateInit2_(z_streamp z, int w, const char *version, int stream_size)
984263bc
MD
3146{
3147 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3148 stream_size != sizeof(z_stream))
3149 return Z_VERSION_ERROR;
3150
3151 /* initialize state */
3152 if (z == Z_NULL)
3153 return Z_STREAM_ERROR;
3154 z->msg = Z_NULL;
3155#ifndef NO_ZCFUNCS
3156 if (z->zalloc == Z_NULL)
3157 {
3158 z->zalloc = zcalloc;
3159 z->opaque = (voidpf)0;
3160 }
3161 if (z->zfree == Z_NULL) z->zfree = zcfree;
3162#endif
3163 if ((z->state = (struct internal_state FAR *)
3164 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3165 return Z_MEM_ERROR;
3166 z->state->blocks = Z_NULL;
3167
3168 /* handle undocumented nowrap option (no zlib header or check) */
3169 z->state->nowrap = 0;
3170 if (w < 0)
3171 {
3172 w = - w;
3173 z->state->nowrap = 1;
3174 }
3175
3176 /* set window size */
3177 if (w < 8 || w > 15)
3178 {
3179 inflateEnd(z);
3180 return Z_STREAM_ERROR;
3181 }
3182 z->state->wbits = (uInt)w;
3183
3184 /* create inflate_blocks state */
3185 if ((z->state->blocks =
3186 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3187 == Z_NULL)
3188 {
3189 inflateEnd(z);
3190 return Z_MEM_ERROR;
3191 }
3192 Trace((stderr, "inflate: allocated\n"));
3193
3194 /* reset state */
3195 inflateReset(z);
3196 return Z_OK;
3197}
3198
3199
bf8c57c6
SW
3200int
3201inflateInit_(z_streamp z, const char *version, int stream_size)
984263bc
MD
3202{
3203 return inflateInit2_(z, DEF_WBITS, version, stream_size);
3204}
3205
3206
3207#define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3208#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3209
bf8c57c6
SW
3210int
3211inflate(z_streamp z, int f)
984263bc
MD
3212{
3213 int r;
3214 uInt b;
3215
3216 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0)
3217 return Z_STREAM_ERROR;
3218 r = Z_BUF_ERROR;
3219 while (1) switch (z->state->mode)
3220 {
3221 case METHOD:
3222 NEEDBYTE
3223 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3224 {
3225 z->state->mode = BAD;
3226 z->msg = (char*)"unknown compression method";
3227 z->state->sub.marker = 5; /* can't try inflateSync */
3228 break;
3229 }
3230 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3231 {
3232 z->state->mode = BAD;
3233 z->msg = (char*)"invalid window size";
3234 z->state->sub.marker = 5; /* can't try inflateSync */
3235 break;
3236 }
3237 z->state->mode = FLAG;
3238 case FLAG:
3239 NEEDBYTE
3240 b = NEXTBYTE;
3241 if (((z->state->sub.method << 8) + b) % 31)
3242 {
3243 z->state->mode = BAD;
3244 z->msg = (char*)"incorrect header check";
3245 z->state->sub.marker = 5; /* can't try inflateSync */
3246 break;
3247 }
3248 Trace((stderr, "inflate: zlib header ok\n"));
3249 if (!(b & PRESET_DICT))
3250 {
3251 z->state->mode = BLOCKS;
3252 break;
3253 }
3254 z->state->mode = DICT4;
3255 case DICT4:
3256 NEEDBYTE
3257 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3258 z->state->mode = DICT3;
3259 case DICT3:
3260 NEEDBYTE
3261 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3262 z->state->mode = DICT2;
3263 case DICT2:
3264 NEEDBYTE
3265 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3266 z->state->mode = DICT1;
3267 case DICT1:
3268 NEEDBYTE
3269 z->state->sub.check.need += (uLong)NEXTBYTE;
3270 z->adler = z->state->sub.check.need;
3271 z->state->mode = DICT0;
3272 return Z_NEED_DICT;
3273 case DICT0:
3274 z->state->mode = BAD;
3275 z->msg = (char*)"need dictionary";
3276 z->state->sub.marker = 0; /* can try inflateSync */
3277 return Z_STREAM_ERROR;
3278 case BLOCKS:
3279 r = inflate_blocks(z->state->blocks, z, r);
3280 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3281 r = inflate_packet_flush(z->state->blocks);
3282 if (r == Z_DATA_ERROR)
3283 {
3284 z->state->mode = BAD;
3285 z->state->sub.marker = 0; /* can try inflateSync */
3286 break;
3287 }
3288 if (r != Z_STREAM_END)
3289 return r;
3290 r = Z_OK;
3291 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3292 if (z->state->nowrap)
3293 {
3294 z->state->mode = DONE;
3295 break;
3296 }
3297 z->state->mode = CHECK4;
3298 case CHECK4:
3299 NEEDBYTE
3300 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3301 z->state->mode = CHECK3;
3302 case CHECK3:
3303 NEEDBYTE
3304 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3305 z->state->mode = CHECK2;
3306 case CHECK2:
3307 NEEDBYTE
3308 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3309 z->state->mode = CHECK1;
3310 case CHECK1:
3311 NEEDBYTE
3312 z->state->sub.check.need += (uLong)NEXTBYTE;
3313
3314 if (z->state->sub.check.was != z->state->sub.check.need)
3315 {
3316 z->state->mode = BAD;
3317 z->msg = (char*)"incorrect data check";
3318 z->state->sub.marker = 5; /* can't try inflateSync */
3319 break;
3320 }
3321 Trace((stderr, "inflate: zlib check ok\n"));
3322 z->state->mode = DONE;
3323 case DONE:
3324 return Z_STREAM_END;
3325 case BAD:
3326 return Z_DATA_ERROR;
3327 default:
3328 return Z_STREAM_ERROR;
3329 }
3330
3331 empty:
3332 if (f != Z_PACKET_FLUSH)
3333 return r;
3334 z->state->mode = BAD;
3335 z->msg = (char *)"need more for packet flush";
3336 z->state->sub.marker = 0; /* can try inflateSync */
3337 return Z_DATA_ERROR;
3338}
3339
3340
bf8c57c6
SW
3341int
3342inflateSetDictionary(z_streamp z, const Bytef *dictionary, uInt dictLength)
984263bc
MD
3343{
3344 uInt length = dictLength;
3345
3346 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3347 return Z_STREAM_ERROR;
3348
3349 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3350 z->adler = 1L;
3351
3352 if (length >= ((uInt)1<<z->state->wbits))
3353 {
3354 length = (1<<z->state->wbits)-1;
3355 dictionary += dictLength - length;
3356 }
3357 inflate_set_dictionary(z->state->blocks, dictionary, length);
3358 z->state->mode = BLOCKS;
3359 return Z_OK;
3360}
3361
3362/*
3363 * This subroutine adds the data at next_in/avail_in to the output history
3364 * without performing any output. The output buffer must be "caught up";
3365 * i.e. no pending output (hence s->read equals s->write), and the state must
3366 * be BLOCKS (i.e. we should be willing to see the start of a series of
3367 * BLOCKS). On exit, the output will also be caught up, and the checksum
3368 * will have been updated if need be.
3369 */
3370
bf8c57c6
SW
3371int
3372inflateIncomp(z_stream *z)
984263bc
MD
3373{
3374 if (z->state->mode != BLOCKS)
3375 return Z_DATA_ERROR;
3376 return inflate_addhistory(z->state->blocks, z);
3377}
3378
3379
bf8c57c6
SW
3380int
3381inflateSync(z_streamp z)
984263bc
MD
3382{
3383 uInt n; /* number of bytes to look at */
3384 Bytef *p; /* pointer to bytes */
3385 uInt m; /* number of marker bytes found in a row */
3386 uLong r, w; /* temporaries to save total_in and total_out */
3387
3388 /* set up */
3389 if (z == Z_NULL || z->state == Z_NULL)
3390 return Z_STREAM_ERROR;
3391 if (z->state->mode != BAD)
3392 {
3393 z->state->mode = BAD;
3394 z->state->sub.marker = 0;
3395 }
3396 if ((n = z->avail_in) == 0)
3397 return Z_BUF_ERROR;
3398 p = z->next_in;
3399 m = z->state->sub.marker;
3400
3401 /* search */
3402 while (n && m < 4)
3403 {
3404 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3405 m++;
3406 else if (*p)
3407 m = 0;
3408 else
3409 m = 4 - m;
3410 p++, n--;
3411 }
3412
3413 /* restore */
3414 z->total_in += p - z->next_in;
3415 z->next_in = p;
3416 z->avail_in = n;
3417 z->state->sub.marker = m;
3418
3419 /* return no joy or set up to restart on a new block */
3420 if (m != 4)
3421 return Z_DATA_ERROR;
3422 r = z->total_in; w = z->total_out;
3423 inflateReset(z);
3424 z->total_in = r; z->total_out = w;
3425 z->state->mode = BLOCKS;
3426 return Z_OK;
3427}
3428
3429#undef NEEDBYTE
3430#undef NEXTBYTE
3431/* --- inflate.c */
3432
3433/* +++ infblock.c */
3434/* infblock.c -- interpret and process block types to last block
3435 * Copyright (C) 1995-1996 Mark Adler
3436 * For conditions of distribution and use, see copyright notice in zlib.h
3437 */
3438
3439/* #include "zutil.h" */
3440/* #include "infblock.h" */
3441
3442/* +++ inftrees.h */
3443/* inftrees.h -- header to use inftrees.c
3444 * Copyright (C) 1995-1996 Mark Adler
3445 * For conditions of distribution and use, see copyright notice in zlib.h
3446 */
3447
3448/* WARNING: this file should *not* be used by applications. It is
3449 part of the implementation of the compression library and is
3450 subject to change. Applications should only use zlib.h.
3451 */
3452
3453/* Huffman code lookup table entry--this entry is four bytes for machines
3454 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3455
3456typedef struct inflate_huft_s FAR inflate_huft;
3457
3458struct inflate_huft_s {
3459 union {
3460 struct {
3461 Byte Exop; /* number of extra bits or operation */
3462 Byte Bits; /* number of bits in this code or subcode */
3463 } what;
3464 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
3465 } word; /* 16-bit, 8 bytes for 32-bit machines) */
3466 union {
3467 uInt Base; /* literal, length base, or distance base */
3468 inflate_huft *Next; /* pointer to next level of table */
3469 } more;
3470};
3471
3472#ifdef DEBUG_ZLIB
3473 extern uInt inflate_hufts;
3474#endif
3475
3476extern int inflate_trees_bits OF((
3477 uIntf *, /* 19 code lengths */
3478 uIntf *, /* bits tree desired/actual depth */
3479 inflate_huft * FAR *, /* bits tree result */
3480 z_streamp )); /* for zalloc, zfree functions */
3481
3482extern int inflate_trees_dynamic OF((
3483 uInt, /* number of literal/length codes */
3484 uInt, /* number of distance codes */
3485 uIntf *, /* that many (total) code lengths */
3486 uIntf *, /* literal desired/actual bit depth */
3487 uIntf *, /* distance desired/actual bit depth */
3488 inflate_huft * FAR *, /* literal/length tree result */
3489 inflate_huft * FAR *, /* distance tree result */
3490 z_streamp )); /* for zalloc, zfree functions */
3491
3492extern int inflate_trees_fixed OF((
3493 uIntf *, /* literal desired/actual bit depth */
3494 uIntf *, /* distance desired/actual bit depth */
3495 inflate_huft * FAR *, /* literal/length tree result */
3496 inflate_huft * FAR *)); /* distance tree result */
3497
3498extern int inflate_trees_free OF((
3499 inflate_huft *, /* tables to free */
3500 z_streamp )); /* for zfree function */
3501
3502/* --- inftrees.h */
3503
3504/* +++ infcodes.h */
3505/* infcodes.h -- header to use infcodes.c
3506 * Copyright (C) 1995-1996 Mark Adler
3507 * For conditions of distribution and use, see copyright notice in zlib.h
3508 */
3509
3510/* WARNING: this file should *not* be used by applications. It is
3511 part of the implementation of the compression library and is
3512 subject to change. Applications should only use zlib.h.
3513 */
3514
3515struct inflate_codes_state;
3516typedef struct inflate_codes_state FAR inflate_codes_statef;
3517
3518extern inflate_codes_statef *inflate_codes_new OF((
3519 uInt, uInt,
3520 inflate_huft *, inflate_huft *,
3521 z_streamp ));
3522
3523extern int inflate_codes OF((
3524 inflate_blocks_statef *,
3525 z_streamp ,
3526 int));
3527
3528extern void inflate_codes_free OF((
3529 inflate_codes_statef *,
3530 z_streamp ));
3531
3532/* --- infcodes.h */
3533
3534/* +++ infutil.h */
3535/* infutil.h -- types and macros common to blocks and codes
3536 * Copyright (C) 1995-1996 Mark Adler
3537 * For conditions of distribution and use, see copyright notice in zlib.h
3538 */
3539
3540/* WARNING: this file should *not* be used by applications. It is
3541 part of the implementation of the compression library and is
3542 subject to change. Applications should only use zlib.h.
3543 */
3544
3545#ifndef _INFUTIL_H
3546#define _INFUTIL_H
3547
3548typedef enum {
3549 TYPE, /* get type bits (3, including end bit) */
3550 LENS, /* get lengths for stored */
3551 STORED, /* processing stored block */
3552 TABLE, /* get table lengths */
3553 BTREE, /* get bit lengths tree for a dynamic block */
3554 DTREE, /* get length, distance trees for a dynamic block */
3555 CODES, /* processing fixed or dynamic block */
3556 DRY, /* output remaining window bytes */
3557 DONEB, /* finished last block, done */
3558 BADB} /* got a data error--stuck here */
3559inflate_block_mode;
3560
3561/* inflate blocks semi-private state */
3562struct inflate_blocks_state {
3563
3564 /* mode */
3565 inflate_block_mode mode; /* current inflate_block mode */
3566
3567 /* mode dependent information */
3568 union {
3569 uInt left; /* if STORED, bytes left to copy */
3570 struct {
3571 uInt table; /* table lengths (14 bits) */
3572 uInt index; /* index into blens (or border) */
3573 uIntf *blens; /* bit lengths of codes */
3574 uInt bb; /* bit length tree depth */
3575 inflate_huft *tb; /* bit length decoding tree */
3576 } trees; /* if DTREE, decoding info for trees */
3577 struct {
3578 inflate_huft *tl;
3579 inflate_huft *td; /* trees to free */
3580 inflate_codes_statef
3581 *codes;
3582 } decode; /* if CODES, current state */
3583 } sub; /* submode */
3584 uInt last; /* true if this block is the last block */
3585
3586 /* mode independent information */
3587 uInt bitk; /* bits in bit buffer */
3588 uLong bitb; /* bit buffer */
3589 Bytef *window; /* sliding window */
3590 Bytef *end; /* one byte after sliding window */
3591 Bytef *read; /* window read pointer */
3592 Bytef *write; /* window write pointer */
3593 check_func checkfn; /* check function */
3594 uLong check; /* check on output */
3595
3596};
3597
3598
3599/* defines for inflate input/output */
3600/* update pointers and return */
3601#define UPDBITS {s->bitb=b;s->bitk=k;}
3602#define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3603#define UPDOUT {s->write=q;}
3604#define UPDATE {UPDBITS UPDIN UPDOUT}
3605#define LEAVE {UPDATE return inflate_flush(s,z,r);}
3606/* get bytes and bits */
3607#define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3608#define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3609#define NEXTBYTE (n--,*p++)
3610#define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3611#define DUMPBITS(j) {b>>=(j);k-=(j);}
3612/* output bytes */
3613#define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3614#define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3615#define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3616#define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3617#define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;}
3618#define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3619/* load local pointers */
3620#define LOAD {LOADIN LOADOUT}
3621
3622/* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3623extern uInt inflate_mask[17];
3624
3625/* copy as much as possible from the sliding window to the output area */
3626extern int inflate_flush OF((
3627 inflate_blocks_statef *,
3628 z_streamp ,
3629 int));
3630
3631#ifndef NO_DUMMY_DECL
3632struct internal_state {int dummy;}; /* for buggy compilers */
3633#endif
3634
3635#endif
3636/* --- infutil.h */
3637
3638#ifndef NO_DUMMY_DECL
3639struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3640#endif
3641
3642/* Table for deflate from PKZIP's appnote.txt. */
3643local const uInt border[] = { /* Order of the bit length code lengths */
3644 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3645
3646/*
3647 Notes beyond the 1.93a appnote.txt:
3648
3649 1. Distance pointers never point before the beginning of the output
3650 stream.
3651 2. Distance pointers can point back across blocks, up to 32k away.
3652 3. There is an implied maximum of 7 bits for the bit length table and
3653 15 bits for the actual data.
3654 4. If only one code exists, then it is encoded using one bit. (Zero
3655 would be more efficient, but perhaps a little confusing.) If two
3656 codes exist, they are coded using one bit each (0 and 1).
3657 5. There is no way of sending zero distance codes--a dummy must be
3658 sent if there are none. (History: a pre 2.0 version of PKZIP would
3659 store blocks with no distance codes, but this was discovered to be
3660 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3661 zero distance codes, which is sent as one code of zero bits in
3662 length.
3663 6. There are up to 286 literal/length codes. Code 256 represents the
3664 end-of-block. Note however that the static length tree defines
3665 288 codes just to fill out the Huffman codes. Codes 286 and 287
3666 cannot be used though, since there is no length base or extra bits
3667 defined for them. Similarily, there are up to 30 distance codes.
3668 However, static trees define 32 codes (all 5 bits) to fill out the
3669 Huffman codes, but the last two had better not show up in the data.
3670 7. Unzip can check dynamic Huffman blocks for complete code sets.
3671 The exception is that a single code would not be complete (see #4).
3672 8. The five bits following the block type is really the number of
3673 literal codes sent minus 257.
3674 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3675 (1+6+6). Therefore, to output three times the length, you output
3676 three codes (1+1+1), whereas to output four times the same length,
3677 you only need two codes (1+3). Hmm.
3678 10. In the tree reconstruction algorithm, Code = Code + Increment
3679 only if BitLength(i) is not zero. (Pretty obvious.)
3680 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3681 12. Note: length code 284 can represent 227-258, but length code 285
3682 really is 258. The last length deserves its own, short code
3683 since it gets used a lot in very redundant files. The length
3684 258 is special since 258 - 3 (the min match length) is 255.
3685 13. The literal/length and distance code bit lengths are read as a
3686 single stream of lengths. It is possible (and advantageous) for
3687 a repeat code (16, 17, or 18) to go across the boundary between
3688 the two sets of lengths.
3689 */
3690
3691
bf8c57c6
SW
3692void
3693inflate_blocks_reset(inflate_blocks_statef *s, z_streamp z, uLongf *c)
984263bc
MD
3694{
3695 if (s->checkfn != Z_NULL)
3696 *c = s->check;
3697 if (s->mode == BTREE || s->mode == DTREE)
3698 ZFREE(z, s->sub.trees.blens);
3699 if (s->mode == CODES)
3700 {
3701 inflate_codes_free(s->sub.decode.codes, z);
3702 inflate_trees_free(s->sub.decode.td, z);
3703 inflate_trees_free(s->sub.decode.tl, z);
3704 }
3705 s->mode = TYPE;
3706 s->bitk = 0;
3707 s->bitb = 0;
3708 s->read = s->write = s->window;
3709 if (s->checkfn != Z_NULL)
3710 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
3711 Trace((stderr, "inflate: blocks reset\n"));
3712}
3713
3714
bf8c57c6
SW
3715inflate_blocks_statef *
3716inflate_blocks_new(z_streamp z, check_func c, uInt w)
984263bc
MD
3717{
3718 inflate_blocks_statef *s;
3719
3720 if ((s = (inflate_blocks_statef *)ZALLOC
3721 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3722 return s;
3723 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3724 {
3725 ZFREE(z, s);
3726 return Z_NULL;
3727 }
3728 s->end = s->window + w;
3729 s->checkfn = c;
3730 s->mode = TYPE;
3731 Trace((stderr, "inflate: blocks allocated\n"));
3732 inflate_blocks_reset(s, z, &s->check);
3733 return s;
3734}
3735
3736
3737#ifdef DEBUG_ZLIB
3738 extern uInt inflate_hufts;
3739#endif
bf8c57c6
SW
3740
3741int
3742inflate_blocks(inflate_blocks_statef *s, z_streamp z, int r)
984263bc
MD
3743{
3744 uInt t; /* temporary storage */
3745 uLong b; /* bit buffer */
3746 uInt k; /* bits in bit buffer */
3747 Bytef *p; /* input data pointer */
3748 uInt n; /* bytes available there */
3749 Bytef *q; /* output window write pointer */
3750 uInt m; /* bytes to end of window or read pointer */
3751
3752 /* copy input/output information to locals (UPDATE macro restores) */
3753 LOAD
3754
3755 /* process input based on current state */
3756 while (1) switch (s->mode)
3757 {
3758 case TYPE:
3759 NEEDBITS(3)
3760 t = (uInt)b & 7;
3761 s->last = t & 1;
3762 switch (t >> 1)
3763 {
3764 case 0: /* stored */
3765 Trace((stderr, "inflate: stored block%s\n",
3766 s->last ? " (last)" : ""));
3767 DUMPBITS(3)
3768 t = k & 7; /* go to byte boundary */
3769 DUMPBITS(t)
3770 s->mode = LENS; /* get length of stored block */
3771 break;
3772 case 1: /* fixed */
3773 Trace((stderr, "inflate: fixed codes block%s\n",
3774 s->last ? " (last)" : ""));
3775 {
3776 uInt bl, bd;
3777 inflate_huft *tl, *td;
3778
3779 inflate_trees_fixed(&bl, &bd, &tl, &td);
3780 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3781 if (s->sub.decode.codes == Z_NULL)
3782 {
3783 r = Z_MEM_ERROR;
3784 LEAVE
3785 }
3786 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3787 s->sub.decode.td = Z_NULL;
3788 }
3789 DUMPBITS(3)
3790 s->mode = CODES;
3791 break;
3792 case 2: /* dynamic */
3793 Trace((stderr, "inflate: dynamic codes block%s\n",
3794 s->last ? " (last)" : ""));
3795 DUMPBITS(3)
3796 s->mode = TABLE;
3797 break;
3798 case 3: /* illegal */
3799 DUMPBITS(3)
3800 s->mode = BADB;
3801 z->msg = (char*)"invalid block type";
3802 r = Z_DATA_ERROR;
3803 LEAVE
3804 }
3805 break;
3806 case LENS:
3807 NEEDBITS(32)
3808 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
3809 {
3810 s->mode = BADB;
3811 z->msg = (char*)"invalid stored block lengths";
3812 r = Z_DATA_ERROR;
3813 LEAVE
3814 }
3815 s->sub.left = (uInt)b & 0xffff;
3816 b = k = 0; /* dump bits */
3817 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3818 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
3819 break;
3820 case STORED:
3821 if (n == 0)
3822 LEAVE
3823 NEEDOUT
3824 t = s->sub.left;
3825 if (t > n) t = n;
3826 if (t > m) t = m;
3827 zmemcpy(q, p, t);
3828 p += t; n -= t;
3829 q += t; m -= t;
3830 if ((s->sub.left -= t) != 0)
3831 break;
3832 Tracev((stderr, "inflate: stored end, %lu total out\n",
3833 z->total_out + (q >= s->read ? q - s->read :
3834 (s->end - s->read) + (q - s->window))));
3835 s->mode = s->last ? DRY : TYPE;
3836 break;
3837 case TABLE:
3838 NEEDBITS(14)
3839 s->sub.trees.table = t = (uInt)b & 0x3fff;
3840#ifndef PKZIP_BUG_WORKAROUND
3841 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3842 {
3843 s->mode = BADB;
3844 z->msg = (char*)"too many length or distance symbols";
3845 r = Z_DATA_ERROR;
3846 LEAVE
3847 }
3848#endif
3849 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3850 if (t < 19)
3851 t = 19;
3852 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3853 {
3854 r = Z_MEM_ERROR;
3855 LEAVE
3856 }
3857 DUMPBITS(14)
3858 s->sub.trees.index = 0;
3859 Tracev((stderr, "inflate: table sizes ok\n"));
3860 s->mode = BTREE;
3861 case BTREE:
3862 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3863 {
3864 NEEDBITS(3)
3865 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3866 DUMPBITS(3)
3867 }
3868 while (s->sub.trees.index < 19)
3869 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3870 s->sub.trees.bb = 7;
3871 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3872 &s->sub.trees.tb, z);
3873 if (t != Z_OK)
3874 {
3875 r = t;
3876 if (r == Z_DATA_ERROR) {
3877 ZFREE(z, s->sub.trees.blens);
3878 s->mode = BADB;
3879 }
3880 LEAVE
3881 }
3882 s->sub.trees.index = 0;
3883 Tracev((stderr, "inflate: bits tree ok\n"));
3884 s->mode = DTREE;
3885 case DTREE:
3886 while (t = s->sub.trees.table,
3887 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3888 {
3889 inflate_huft *h;
3890 uInt i, j, c;
3891
3892 t = s->sub.trees.bb;
3893 NEEDBITS(t)
3894 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3895 t = h->word.what.Bits;
3896 c = h->more.Base;
3897 if (c < 16)
3898 {
3899 DUMPBITS(t)
3900 s->sub.trees.blens[s->sub.trees.index++] = c;
3901 }
3902 else /* c == 16..18 */
3903 {
3904 i = c == 18 ? 7 : c - 14;
3905 j = c == 18 ? 11 : 3;
3906 NEEDBITS(t + i)
3907 DUMPBITS(t)
3908 j += (uInt)b & inflate_mask[i];
3909 DUMPBITS(i)
3910 i = s->sub.trees.index;
3911 t = s->sub.trees.table;
3912 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3913 (c == 16 && i < 1))
3914 {
3915 inflate_trees_free(s->sub.trees.tb, z);
3916 ZFREE(z, s->sub.trees.blens);
3917 s->mode = BADB;
3918 z->msg = (char*)"invalid bit length repeat";
3919 r = Z_DATA_ERROR;
3920 LEAVE
3921 }
3922 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3923 do {
3924 s->sub.trees.blens[i++] = c;
3925 } while (--j);
3926 s->sub.trees.index = i;
3927 }
3928 }
3929 inflate_trees_free(s->sub.trees.tb, z);
3930 s->sub.trees.tb = Z_NULL;
3931 {
3932 uInt bl, bd;
3933 inflate_huft *tl, *td;
3934 inflate_codes_statef *c;
3935
3936 bl = 9; /* must be <= 9 for lookahead assumptions */
3937 bd = 6; /* must be <= 9 for lookahead assumptions */
3938 t = s->sub.trees.table;
3939#ifdef DEBUG_ZLIB
3940 inflate_hufts = 0;
3941#endif
3942 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3943 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3944 if (t != Z_OK)
3945 {
3946 if (t == (uInt)Z_DATA_ERROR) {
3947 ZFREE(z, s->sub.trees.blens);
3948 s->mode = BADB;
3949 }
3950 r = t;
3951 LEAVE
3952 }
3953 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n",
3954 inflate_hufts, sizeof(inflate_huft)));
3955 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3956 {
3957 inflate_trees_free(td, z);
3958 inflate_trees_free(tl, z);
3959 r = Z_MEM_ERROR;
3960 LEAVE
3961 }
3962 /*
3963 * this ZFREE must occur *BEFORE* we mess with sub.decode, because
3964 * sub.trees is union'd with sub.decode.
3965 */
3966 ZFREE(z, s->sub.trees.blens);
3967 s->sub.decode.codes = c;
3968 s->sub.decode.tl = tl;
3969 s->sub.decode.td = td;
3970 }
3971 s->mode = CODES;
3972 case CODES:
3973 UPDATE
3974 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3975 return inflate_flush(s, z, r);
3976 r = Z_OK;
3977 inflate_codes_free(s->sub.decode.codes, z);
3978 inflate_trees_free(s->sub.decode.td, z);
3979 inflate_trees_free(s->sub.decode.tl, z);
3980 LOAD
3981 Tracev((stderr, "inflate: codes end, %lu total out\n",
3982 z->total_out + (q >= s->read ? q - s->read :
3983 (s->end - s->read) + (q - s->window))));
3984 if (!s->last)
3985 {
3986 s->mode = TYPE;
3987 break;
3988 }
3989 if (k > 7) /* return unused byte, if any */
3990 {
3991 Assert(k < 16, "inflate_codes grabbed too many bytes")
3992 k -= 8;
3993 n++;
3994 p--; /* can always return one */
3995 }
3996 s->mode = DRY;
3997 case DRY:
3998 FLUSH
3999 if (s->read != s->write)
4000 LEAVE
4001 s->mode = DONEB;
4002 case DONEB:
4003 r = Z_STREAM_END;
4004 LEAVE
4005 case BADB:
4006 r = Z_DATA_ERROR;
4007 LEAVE
4008 default:
4009 r = Z_STREAM_ERROR;