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.
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
13 * $FreeBSD: src/sys/net/zlib.c,v 1.10.2.3 2002/03/24 23:12:48 jedgar Exp $
14 * $DragonFly: src/sys/net/zlib.c,v 1.2 2003/06/17 04:28:48 dillon Exp $
18 * ==FILEVERSION 971210==
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.
28 #if defined(__FreeBSD__) && defined(_KERNEL)
29 #define inflate inflate_ppp /* FreeBSD already has an inflate :-( */
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
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.
44 /* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */
56 /* Assume this is a *BSD or SVR4 kernel */
57 #include <sys/types.h>
59 #include <sys/systm.h>
61 # define memcpy(d, s, n) bcopy((s), (d), (n))
62 # define memset(d, v, n) bzero((d), (n))
66 #if defined(__KERNEL__)
67 /* Assume this is a Linux kernel */
68 #include <linux/string.h>
71 #else /* not kernel */
73 #if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS)
83 #endif /* __KERNEL__ */
89 /* compile with -Dlocal if your debugger can't find static symbols */
91 typedef unsigned char uch;
93 typedef unsigned short ush;
95 typedef unsigned long ulg;
97 extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
98 /* (size given to avoid silly warnings with Visual C++) */
100 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
102 #define ERR_RETURN(strm,err) \
103 return (strm->msg = (const char*)ERR_MSG(err), (err))
104 /* To be used only when the state is known to be valid */
106 /* common constants */
109 # define DEF_WBITS MAX_WBITS
111 /* default windowBits for decompression. MAX_WBITS is for compression only */
113 #if MAX_MEM_LEVEL >= 8
114 # define DEF_MEM_LEVEL 8
116 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
118 /* default memLevel */
120 #define STORED_BLOCK 0
121 #define STATIC_TREES 1
123 /* The three kinds of block type */
126 #define MAX_MATCH 258
127 /* The minimum and maximum match lengths */
129 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
131 /* target dependencies */
134 # define OS_CODE 0x00
137 # else /* MSC or DJGPP */
143 # define OS_CODE 0x06
146 #ifdef WIN32 /* Window 95 & Windows NT */
147 # define OS_CODE 0x0b
150 #if defined(VAXC) || defined(VMS)
151 # define OS_CODE 0x02
152 # define FOPEN(name, mode) \
153 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
157 # define OS_CODE 0x01
160 #if defined(ATARI) || defined(atarist)
161 # define OS_CODE 0x05
165 # define OS_CODE 0x07
168 #ifdef __50SERIES /* Prime/PRIMOS */
169 # define OS_CODE 0x0F
173 # define OS_CODE 0x0a
176 #if defined(_BEOS_) || defined(RISCOS)
177 # define fdopen(fd,mode) NULL /* No fdopen() */
180 /* Common defaults */
183 # define OS_CODE 0x03 /* assume Unix */
187 # define FOPEN(name, mode) fopen((name), (mode))
193 extern char *strerror OF((int));
194 # define zstrerror(errnum) strerror(errnum)
196 # define zstrerror(errnum) ""
202 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
203 /* Use our own functions for small and medium model with MSC <= 5.0.
204 * You may have to use the same strategy for Borland C (untested).
208 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
212 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */
213 # define zmemcpy _fmemcpy
214 # define zmemcmp _fmemcmp
215 # define zmemzero(dest, len) _fmemset(dest, 0, len)
217 # define zmemcpy memcpy
218 # define zmemcmp memcmp
219 # define zmemzero(dest, len) memset(dest, 0, len)
222 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
223 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len));
224 extern void zmemzero OF((Bytef* dest, uInt len));
227 /* Diagnostic functions */
233 extern void z_error OF((char *m));
234 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
235 # define Trace(x) fprintf x
236 # define Tracev(x) {if (verbose) fprintf x ;}
237 # define Tracevv(x) {if (verbose>1) fprintf x ;}
238 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
239 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
241 # define Assert(cond,msg)
246 # define Tracecv(c,x)
250 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));
252 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
253 void zcfree OF((voidpf opaque, voidpf ptr));
255 #define ZALLOC(strm, items, size) \
256 (*((strm)->zalloc))((strm)->opaque, (items), (size))
257 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
258 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
260 #endif /* _Z_UTIL_H */
264 /* deflate.h -- internal compression state
265 * Copyright (C) 1995-1996 Jean-loup Gailly
266 * For conditions of distribution and use, see copyright notice in zlib.h
269 /* WARNING: this file should *not* be used by applications. It is
270 part of the implementation of the compression library and is
271 subject to change. Applications should only use zlib.h.
274 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */
279 /* #include "zutil.h" */
281 /* ===========================================================================
282 * Internal compression state.
285 #define LENGTH_CODES 29
286 /* number of length codes, not counting the special END_BLOCK code */
289 /* number of literal bytes 0..255 */
291 #define L_CODES (LITERALS+1+LENGTH_CODES)
292 /* number of Literal or Length codes, including the END_BLOCK code */
295 /* number of distance codes */
298 /* number of codes used to transfer the bit lengths */
300 #define HEAP_SIZE (2*L_CODES+1)
301 /* maximum heap size */
304 /* All codes must not exceed MAX_BITS bits */
306 #define INIT_STATE 42
307 #define BUSY_STATE 113
308 #define FINISH_STATE 666
312 /* Data structure describing a single value and its code string. */
313 typedef struct ct_data_s {
315 ush freq; /* frequency count */
316 ush code; /* bit string */
319 ush dad; /* father node in Huffman tree */
320 ush len; /* length of bit string */
329 typedef struct static_tree_desc_s static_tree_desc;
331 typedef struct tree_desc_s {
332 ct_data *dyn_tree; /* the dynamic tree */
333 int max_code; /* largest code with non zero frequency */
334 static_tree_desc *stat_desc; /* the corresponding static tree */
338 typedef Pos FAR Posf;
339 typedef unsigned IPos;
341 /* A Pos is an index in the character window. We use short instead of int to
342 * save space in the various tables. IPos is used only for parameter passing.
345 typedef struct deflate_state {
346 z_streamp strm; /* pointer back to this zlib stream */
347 int status; /* as the name implies */
348 Bytef *pending_buf; /* output still pending */
349 ulg pending_buf_size; /* size of pending_buf */
350 Bytef *pending_out; /* next pending byte to output to the stream */
351 int pending; /* nb of bytes in the pending buffer */
352 int noheader; /* suppress zlib header and adler32 */
353 Byte data_type; /* UNKNOWN, BINARY or ASCII */
354 Byte method; /* STORED (for zip only) or DEFLATED */
355 int last_flush; /* value of flush param for previous deflate call */
357 /* used by deflate.c: */
359 uInt w_size; /* LZ77 window size (32K by default) */
360 uInt w_bits; /* log2(w_size) (8..16) */
361 uInt w_mask; /* w_size - 1 */
364 /* Sliding window. Input bytes are read into the second half of the window,
365 * and move to the first half later to keep a dictionary of at least wSize
366 * bytes. With this organization, matches are limited to a distance of
367 * wSize-MAX_MATCH bytes, but this ensures that IO is always
368 * performed with a length multiple of the block size. Also, it limits
369 * the window size to 64K, which is quite useful on MSDOS.
370 * To do: use the user input buffer as sliding window.
374 /* Actual size of window: 2*wSize, except when the user input buffer
375 * is directly used as sliding window.
379 /* Link to older string with same hash index. To limit the size of this
380 * array to 64K, this link is maintained only for the last 32K strings.
381 * An index in this array is thus a window index modulo 32K.
384 Posf *head; /* Heads of the hash chains or NIL. */
386 uInt ins_h; /* hash index of string to be inserted */
387 uInt hash_size; /* number of elements in hash table */
388 uInt hash_bits; /* log2(hash_size) */
389 uInt hash_mask; /* hash_size-1 */
392 /* Number of bits by which ins_h must be shifted at each input
393 * step. It must be such that after MIN_MATCH steps, the oldest
394 * byte no longer takes part in the hash key, that is:
395 * hash_shift * MIN_MATCH >= hash_bits
399 /* Window position at the beginning of the current output block. Gets
400 * negative when the window is moved backwards.
403 uInt match_length; /* length of best match */
404 IPos prev_match; /* previous match */
405 int match_available; /* set if previous match exists */
406 uInt strstart; /* start of string to insert */
407 uInt match_start; /* start of matching string */
408 uInt lookahead; /* number of valid bytes ahead in window */
411 /* Length of the best match at previous step. Matches not greater than this
412 * are discarded. This is used in the lazy match evaluation.
415 uInt max_chain_length;
416 /* To speed up deflation, hash chains are never searched beyond this
417 * length. A higher limit improves compression ratio but degrades the
422 /* Attempt to find a better match only when the current match is strictly
423 * smaller than this value. This mechanism is used only for compression
426 # define max_insert_length max_lazy_match
427 /* Insert new strings in the hash table only if the match length is not
428 * greater than this length. This saves time but degrades compression.
429 * max_insert_length is used only for compression levels <= 3.
432 int level; /* compression level (1..9) */
433 int strategy; /* favor or force Huffman coding*/
436 /* Use a faster search when the previous match is longer than this */
438 int nice_match; /* Stop searching when current match exceeds this */
440 /* used by trees.c: */
441 /* Didn't use ct_data typedef below to supress compiler warning */
442 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
443 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
444 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
446 struct tree_desc_s l_desc; /* desc. for literal tree */
447 struct tree_desc_s d_desc; /* desc. for distance tree */
448 struct tree_desc_s bl_desc; /* desc. for bit length tree */
450 ush bl_count[MAX_BITS+1];
451 /* number of codes at each bit length for an optimal tree */
453 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
454 int heap_len; /* number of elements in the heap */
455 int heap_max; /* element of largest frequency */
456 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
457 * The same heap array is used to build all trees.
460 uch depth[2*L_CODES+1];
461 /* Depth of each subtree used as tie breaker for trees of equal frequency
464 uchf *l_buf; /* buffer for literals or lengths */
467 /* Size of match buffer for literals/lengths. There are 4 reasons for
468 * limiting lit_bufsize to 64K:
469 * - frequencies can be kept in 16 bit counters
470 * - if compression is not successful for the first block, all input
471 * data is still in the window so we can still emit a stored block even
472 * when input comes from standard input. (This can also be done for
473 * all blocks if lit_bufsize is not greater than 32K.)
474 * - if compression is not successful for a file smaller than 64K, we can
475 * even emit a stored file instead of a stored block (saving 5 bytes).
476 * This is applicable only for zip (not gzip or zlib).
477 * - creating new Huffman trees less frequently may not provide fast
478 * adaptation to changes in the input data statistics. (Take for
479 * example a binary file with poorly compressible code followed by
480 * a highly compressible string table.) Smaller buffer sizes give
481 * fast adaptation but have of course the overhead of transmitting
482 * trees more frequently.
483 * - I can't count above 4
486 uInt last_lit; /* running index in l_buf */
489 /* Buffer for distances. To simplify the code, d_buf and l_buf have
490 * the same number of elements. To use different lengths, an extra flag
491 * array would be necessary.
494 ulg opt_len; /* bit length of current block with optimal trees */
495 ulg static_len; /* bit length of current block with static trees */
496 ulg compressed_len; /* total bit length of compressed file */
497 uInt matches; /* number of string matches in current block */
498 int last_eob_len; /* bit length of EOB code for last block */
501 ulg bits_sent; /* bit length of the compressed data */
505 /* Output buffer. bits are inserted starting at the bottom (least
509 /* Number of valid bits in bi_buf. All bits above the last valid bit
515 /* Output a byte on the stream.
516 * IN assertion: there is enough room in pending_buf.
518 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
521 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
522 /* Minimum amount of lookahead, except at the end of the input file.
523 * See deflate.c for comments about the MIN_MATCH+1.
526 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
527 /* In order to simplify the code, particularly on 16 bit machines, match
528 * distances are limited to MAX_DIST instead of WSIZE.
532 void _tr_init OF((deflate_state *s));
533 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
534 ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
536 void _tr_align OF((deflate_state *s));
537 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
539 void _tr_stored_type_only OF((deflate_state *));
545 /* deflate.c -- compress data using the deflation algorithm
546 * Copyright (C) 1995-1996 Jean-loup Gailly.
547 * For conditions of distribution and use, see copyright notice in zlib.h
553 * The "deflation" process depends on being able to identify portions
554 * of the input text which are identical to earlier input (within a
555 * sliding window trailing behind the input currently being processed).
557 * The most straightforward technique turns out to be the fastest for
558 * most input files: try all possible matches and select the longest.
559 * The key feature of this algorithm is that insertions into the string
560 * dictionary are very simple and thus fast, and deletions are avoided
561 * completely. Insertions are performed at each input character, whereas
562 * string matches are performed only when the previous match ends. So it
563 * is preferable to spend more time in matches to allow very fast string
564 * insertions and avoid deletions. The matching algorithm for small
565 * strings is inspired from that of Rabin & Karp. A brute force approach
566 * is used to find longer strings when a small match has been found.
567 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
568 * (by Leonid Broukhis).
569 * A previous version of this file used a more sophisticated algorithm
570 * (by Fiala and Greene) which is guaranteed to run in linear amortized
571 * time, but has a larger average cost, uses more memory and is patented.
572 * However the F&G algorithm may be faster for some highly redundant
573 * files if the parameter max_chain_length (described below) is too large.
577 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
578 * I found it in 'freeze' written by Leonid Broukhis.
579 * Thanks to many people for bug reports and testing.
583 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
584 * Available in ftp://ds.internic.net/rfc/rfc1951.txt
586 * A description of the Rabin and Karp algorithm is given in the book
587 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
589 * Fiala,E.R., and Greene,D.H.
590 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
594 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */
596 /* #include "deflate.h" */
598 char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly ";
600 If you use the zlib library in a product, an acknowledgment is welcome
601 in the documentation of your product. If for some reason you cannot
602 include such an acknowledgment, I would appreciate that you keep this
603 copyright string in the executable of your product.
606 /* ===========================================================================
607 * Function prototypes.
610 need_more, /* block not completed, need more input or more output */
611 block_done, /* block flush performed */
612 finish_started, /* finish started, need only more output at next deflate */
613 finish_done /* finish done, accept no more input or output */
616 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
617 /* Compression function. Returns the block state after the call. */
619 local void fill_window OF((deflate_state *s));
620 local block_state deflate_stored OF((deflate_state *s, int flush));
621 local block_state deflate_fast OF((deflate_state *s, int flush));
622 local block_state deflate_slow OF((deflate_state *s, int flush));
623 local void lm_init OF((deflate_state *s));
624 local void putShortMSB OF((deflate_state *s, uInt b));
625 local void flush_pending OF((z_streamp strm));
626 local int read_buf OF((z_streamp strm, charf *buf, unsigned size));
628 void match_init OF((void)); /* asm code initialization */
629 uInt longest_match OF((deflate_state *s, IPos cur_match));
631 local uInt longest_match OF((deflate_state *s, IPos cur_match));
635 local void check_match OF((deflate_state *s, IPos start, IPos match,
639 /* ===========================================================================
644 /* Tail of hash chains */
647 # define TOO_FAR 4096
649 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
651 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
652 /* Minimum amount of lookahead, except at the end of the input file.
653 * See deflate.c for comments about the MIN_MATCH+1.
656 /* Values for max_lazy_match, good_match and max_chain_length, depending on
657 * the desired pack level (0..9). The values given below have been tuned to
658 * exclude worst case performance for pathological files. Better values may be
659 * found for specific files.
661 typedef struct config_s {
662 ush good_length; /* reduce lazy search above this match length */
663 ush max_lazy; /* do not perform lazy search above this match length */
664 ush nice_length; /* quit search above this match length */
669 local config configuration_table[10] = {
670 /* good lazy nice chain */
671 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
672 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */
673 /* 2 */ {4, 5, 16, 8, deflate_fast},
674 /* 3 */ {4, 6, 32, 32, deflate_fast},
676 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
677 /* 5 */ {8, 16, 32, 32, deflate_slow},
678 /* 6 */ {8, 16, 128, 128, deflate_slow},
679 /* 7 */ {8, 32, 128, 256, deflate_slow},
680 /* 8 */ {32, 128, 258, 1024, deflate_slow},
681 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
683 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
684 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
689 /* result of memcmp for equal strings */
691 #ifndef NO_DUMMY_DECL
692 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
695 /* ===========================================================================
696 * Update a hash value with the given input byte
697 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
698 * input characters, so that a running hash key can be computed from the
699 * previous key instead of complete recalculation each time.
701 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
704 /* ===========================================================================
705 * Insert string str in the dictionary and set match_head to the previous head
706 * of the hash chain (the most recent string with same hash key). Return
707 * the previous length of the hash chain.
708 * IN assertion: all calls to to INSERT_STRING are made with consecutive
709 * input characters and the first MIN_MATCH bytes of str are valid
710 * (except for the last MIN_MATCH-1 bytes of the input file).
712 #define INSERT_STRING(s, str, match_head) \
713 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
714 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
715 s->head[s->ins_h] = (Pos)(str))
717 /* ===========================================================================
718 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
719 * prev[] will be initialized on the fly.
721 #define CLEAR_HASH(s) \
722 s->head[s->hash_size-1] = NIL; \
723 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
725 /* ========================================================================= */
726 int deflateInit_(strm, level, version, stream_size)
732 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
733 Z_DEFAULT_STRATEGY, version, stream_size);
734 /* To do: ignore strm->next_in if we use it as window */
737 /* ========================================================================= */
738 int deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
739 version, stream_size)
751 static char* my_version = ZLIB_VERSION;
754 /* We overlay pending_buf and d_buf+l_buf. This works since the average
755 * output size for (length,distance) codes is <= 24 bits.
758 if (version == Z_NULL || version[0] != my_version[0] ||
759 stream_size != sizeof(z_stream)) {
760 return Z_VERSION_ERROR;
762 if (strm == Z_NULL) return Z_STREAM_ERROR;
766 if (strm->zalloc == Z_NULL) {
767 strm->zalloc = zcalloc;
768 strm->opaque = (voidpf)0;
770 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
773 if (level == Z_DEFAULT_COMPRESSION) level = 6;
775 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
777 windowBits = -windowBits;
779 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
780 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
781 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
782 return Z_STREAM_ERROR;
784 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
785 if (s == Z_NULL) return Z_MEM_ERROR;
786 strm->state = (struct internal_state FAR *)s;
789 s->noheader = noheader;
790 s->w_bits = windowBits;
791 s->w_size = 1 << s->w_bits;
792 s->w_mask = s->w_size - 1;
794 s->hash_bits = memLevel + 7;
795 s->hash_size = 1 << s->hash_bits;
796 s->hash_mask = s->hash_size - 1;
797 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
799 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
800 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
801 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
803 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
805 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
806 s->pending_buf = (uchf *) overlay;
807 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
809 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
810 s->pending_buf == Z_NULL) {
811 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR);
815 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
816 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
819 s->strategy = strategy;
820 s->method = (Byte)method;
822 return deflateReset(strm);
825 /* ========================================================================= */
826 int deflateSetDictionary (strm, dictionary, dictLength)
828 const Bytef *dictionary;
832 uInt length = dictLength;
836 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
837 return Z_STREAM_ERROR;
839 s = (deflate_state *) strm->state;
840 if (s->status != INIT_STATE) return Z_STREAM_ERROR;
842 strm->adler = adler32(strm->adler, dictionary, dictLength);
844 if (length < MIN_MATCH) return Z_OK;
845 if (length > MAX_DIST(s)) {
846 length = MAX_DIST(s);
847 #ifndef USE_DICT_HEAD
848 dictionary += dictLength - length; /* use the tail of the dictionary */
851 zmemcpy((charf *)s->window, dictionary, length);
852 s->strstart = length;
853 s->block_start = (long)length;
855 /* Insert all strings in the hash table (except for the last two bytes).
856 * s->lookahead stays null, so s->ins_h will be recomputed at the next
857 * call of fill_window.
859 s->ins_h = s->window[0];
860 UPDATE_HASH(s, s->ins_h, s->window[1]);
861 for (n = 0; n <= length - MIN_MATCH; n++) {
862 INSERT_STRING(s, n, hash_head);
864 if (hash_head) hash_head = 0; /* to make compiler happy */
868 /* ========================================================================= */
869 int deflateReset (strm)
874 if (strm == Z_NULL || strm->state == Z_NULL ||
875 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
877 strm->total_in = strm->total_out = 0;
878 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
879 strm->data_type = Z_UNKNOWN;
881 s = (deflate_state *)strm->state;
883 s->pending_out = s->pending_buf;
885 if (s->noheader < 0) {
886 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
888 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
890 s->last_flush = Z_NO_FLUSH;
898 /* ========================================================================= */
899 int deflateParams(strm, level, strategy)
908 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
909 s = (deflate_state *) strm->state;
911 if (level == Z_DEFAULT_COMPRESSION) {
914 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
915 return Z_STREAM_ERROR;
917 func = configuration_table[s->level].func;
919 if (func != configuration_table[level].func && strm->total_in != 0) {
920 /* Flush the last buffer: */
921 err = deflate(strm, Z_PARTIAL_FLUSH);
923 if (s->level != level) {
925 s->max_lazy_match = configuration_table[level].max_lazy;
926 s->good_match = configuration_table[level].good_length;
927 s->nice_match = configuration_table[level].nice_length;
928 s->max_chain_length = configuration_table[level].max_chain;
930 s->strategy = strategy;
934 /* =========================================================================
935 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
936 * IN assertion: the stream state is correct and there is enough room in
939 local void putShortMSB (s, b)
943 put_byte(s, (Byte)(b >> 8));
944 put_byte(s, (Byte)(b & 0xff));
947 /* =========================================================================
948 * Flush as much pending output as possible. All deflate() output goes
949 * through this function so some applications may wish to modify it
950 * to avoid allocating a large strm->next_out buffer and copying into it.
951 * (See also read_buf()).
953 local void flush_pending(strm)
956 deflate_state *s = (deflate_state *) strm->state;
957 unsigned len = s->pending;
959 if (len > strm->avail_out) len = strm->avail_out;
960 if (len == 0) return;
962 if (strm->next_out != Z_NULL) {
963 zmemcpy(strm->next_out, s->pending_out, len);
964 strm->next_out += len;
966 s->pending_out += len;
967 strm->total_out += len;
968 strm->avail_out -= len;
970 if (s->pending == 0) {
971 s->pending_out = s->pending_buf;
975 /* ========================================================================= */
976 int deflate (strm, flush)
980 int old_flush; /* value of flush param for previous deflate call */
983 if (strm == Z_NULL || strm->state == Z_NULL ||
984 flush > Z_FINISH || flush < 0) {
985 return Z_STREAM_ERROR;
987 s = (deflate_state *) strm->state;
989 if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
990 (s->status == FINISH_STATE && flush != Z_FINISH)) {
991 ERR_RETURN(strm, Z_STREAM_ERROR);
993 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
995 s->strm = strm; /* just in case */
996 old_flush = s->last_flush;
997 s->last_flush = flush;
999 /* Write the zlib header */
1000 if (s->status == INIT_STATE) {
1002 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1003 uInt level_flags = (s->level-1) >> 1;
1005 if (level_flags > 3) level_flags = 3;
1006 header |= (level_flags << 6);
1007 if (s->strstart != 0) header |= PRESET_DICT;
1008 header += 31 - (header % 31);
1010 s->status = BUSY_STATE;
1011 putShortMSB(s, header);
1013 /* Save the adler32 of the preset dictionary: */
1014 if (s->strstart != 0) {
1015 putShortMSB(s, (uInt)(strm->adler >> 16));
1016 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1021 /* Flush as much pending output as possible */
1022 if (s->pending != 0) {
1023 flush_pending(strm);
1024 if (strm->avail_out == 0) {
1025 /* Since avail_out is 0, deflate will be called again with
1026 * more output space, but possibly with both pending and
1027 * avail_in equal to zero. There won't be anything to do,
1028 * but this is not an error situation so make sure we
1029 * return OK instead of BUF_ERROR at next call of deflate:
1035 /* Make sure there is something to do and avoid duplicate consecutive
1036 * flushes. For repeated and useless calls with Z_FINISH, we keep
1037 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1039 } else if (strm->avail_in == 0 && flush <= old_flush &&
1040 flush != Z_FINISH) {
1041 ERR_RETURN(strm, Z_BUF_ERROR);
1044 /* User must not provide more input after the first FINISH: */
1045 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1046 ERR_RETURN(strm, Z_BUF_ERROR);
1049 /* Start a new block or continue the current one.
1051 if (strm->avail_in != 0 || s->lookahead != 0 ||
1052 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1055 bstate = (*(configuration_table[s->level].func))(s, flush);
1057 if (bstate == finish_started || bstate == finish_done) {
1058 s->status = FINISH_STATE;
1060 if (bstate == need_more || bstate == finish_started) {
1061 if (strm->avail_out == 0) {
1062 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1065 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1066 * of deflate should use the same flush parameter to make sure
1067 * that the flush is complete. So we don't have to output an
1068 * empty block here, this will be done at next call. This also
1069 * ensures that for a very small output buffer, we emit at most
1073 if (bstate == block_done) {
1074 if (flush == Z_PARTIAL_FLUSH) {
1076 } else if (flush == Z_PACKET_FLUSH) {
1077 /* Output just the 3-bit `stored' block type value,
1078 but not a zero length. */
1079 _tr_stored_type_only(s);
1080 } else { /* FULL_FLUSH or SYNC_FLUSH */
1081 _tr_stored_block(s, (char*)0, 0L, 0);
1082 /* For a full flush, this empty block will be recognized
1083 * as a special marker by inflate_sync().
1085 if (flush == Z_FULL_FLUSH) {
1086 CLEAR_HASH(s); /* forget history */
1089 flush_pending(strm);
1090 if (strm->avail_out == 0) {
1091 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1096 Assert(strm->avail_out > 0, "bug2");
1098 if (flush != Z_FINISH) return Z_OK;
1099 if (s->noheader) return Z_STREAM_END;
1101 /* Write the zlib trailer (adler32) */
1102 putShortMSB(s, (uInt)(strm->adler >> 16));
1103 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1104 flush_pending(strm);
1105 /* If avail_out is zero, the application will call deflate again
1106 * to flush the rest.
1108 s->noheader = -1; /* write the trailer only once! */
1109 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1112 /* ========================================================================= */
1113 int deflateEnd (strm)
1119 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1120 s = (deflate_state *) strm->state;
1123 if (status != INIT_STATE && status != BUSY_STATE &&
1124 status != FINISH_STATE) {
1125 return Z_STREAM_ERROR;
1128 /* Deallocate in reverse order of allocations: */
1129 TRY_FREE(strm, s->pending_buf);
1130 TRY_FREE(strm, s->head);
1131 TRY_FREE(strm, s->prev);
1132 TRY_FREE(strm, s->window);
1135 strm->state = Z_NULL;
1137 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1140 /* =========================================================================
1141 * Copy the source state to the destination state.
1143 int deflateCopy (dest, source)
1151 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
1152 return Z_STREAM_ERROR;
1153 ss = (deflate_state *) source->state;
1155 zmemcpy(dest, source, sizeof(*dest));
1157 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1158 if (ds == Z_NULL) return Z_MEM_ERROR;
1159 dest->state = (struct internal_state FAR *) ds;
1160 zmemcpy(ds, ss, sizeof(*ds));
1163 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1164 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1165 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1166 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1167 ds->pending_buf = (uchf *) overlay;
1169 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1170 ds->pending_buf == Z_NULL) {
1174 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */
1175 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1176 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1177 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1178 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1180 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1181 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1182 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1184 ds->l_desc.dyn_tree = ds->dyn_ltree;
1185 ds->d_desc.dyn_tree = ds->dyn_dtree;
1186 ds->bl_desc.dyn_tree = ds->bl_tree;
1191 /* ===========================================================================
1192 * Return the number of bytes of output which are immediately available
1193 * for output from the decompressor.
1195 int deflateOutputPending (strm)
1198 if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1200 return ((deflate_state *)(strm->state))->pending;
1203 /* ===========================================================================
1204 * Read a new buffer from the current input stream, update the adler32
1205 * and total number of bytes read. All deflate() input goes through
1206 * this function so some applications may wish to modify it to avoid
1207 * allocating a large strm->next_in buffer and copying from it.
1208 * (See also flush_pending()).
1210 local int read_buf(strm, buf, size)
1215 unsigned len = strm->avail_in;
1217 if (len > size) len = size;
1218 if (len == 0) return 0;
1220 strm->avail_in -= len;
1222 if (!((deflate_state *)(strm->state))->noheader) {
1223 strm->adler = adler32(strm->adler, strm->next_in, len);
1225 zmemcpy(buf, strm->next_in, len);
1226 strm->next_in += len;
1227 strm->total_in += len;
1232 /* ===========================================================================
1233 * Initialize the "longest match" routines for a new zlib stream
1235 local void lm_init (s)
1238 s->window_size = (ulg)2L*s->w_size;
1242 /* Set the default configuration parameters:
1244 s->max_lazy_match = configuration_table[s->level].max_lazy;
1245 s->good_match = configuration_table[s->level].good_length;
1246 s->nice_match = configuration_table[s->level].nice_length;
1247 s->max_chain_length = configuration_table[s->level].max_chain;
1250 s->block_start = 0L;
1252 s->match_length = s->prev_length = MIN_MATCH-1;
1253 s->match_available = 0;
1256 match_init(); /* initialize the asm code */
1260 /* ===========================================================================
1261 * Set match_start to the longest match starting at the given string and
1262 * return its length. Matches shorter or equal to prev_length are discarded,
1263 * in which case the result is equal to prev_length and match_start is
1265 * IN assertions: cur_match is the head of the hash chain for the current
1266 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1267 * OUT assertion: the match length is not greater than s->lookahead.
1270 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1271 * match.S. The code will be functionally equivalent.
1273 local uInt longest_match(s, cur_match)
1275 IPos cur_match; /* current match */
1277 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1278 register Bytef *scan = s->window + s->strstart; /* current string */
1279 register Bytef *match; /* matched string */
1280 register int len; /* length of current match */
1281 int best_len = s->prev_length; /* best match length so far */
1282 int nice_match = s->nice_match; /* stop if match long enough */
1283 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1284 s->strstart - (IPos)MAX_DIST(s) : NIL;
1285 /* Stop when cur_match becomes <= limit. To simplify the code,
1286 * we prevent matches with the string of window index 0.
1288 Posf *prev = s->prev;
1289 uInt wmask = s->w_mask;
1292 /* Compare two bytes at a time. Note: this is not always beneficial.
1293 * Try with and without -DUNALIGNED_OK to check.
1295 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1296 register ush scan_start = *(ushf*)scan;
1297 register ush scan_end = *(ushf*)(scan+best_len-1);
1299 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1300 register Byte scan_end1 = scan[best_len-1];
1301 register Byte scan_end = scan[best_len];
1304 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1305 * It is easy to get rid of this optimization if necessary.
1307 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1309 /* Do not waste too much time if we already have a good match: */
1310 if (s->prev_length >= s->good_match) {
1313 /* Do not look for matches beyond the end of the input. This is necessary
1314 * to make deflate deterministic.
1316 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1318 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1321 Assert(cur_match < s->strstart, "no future");
1322 match = s->window + cur_match;
1324 /* Skip to next match if the match length cannot increase
1325 * or if the match length is less than 2:
1327 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1328 /* This code assumes sizeof(unsigned short) == 2. Do not use
1329 * UNALIGNED_OK if your compiler uses a different size.
1331 if (*(ushf*)(match+best_len-1) != scan_end ||
1332 *(ushf*)match != scan_start) continue;
1334 /* It is not necessary to compare scan[2] and match[2] since they are
1335 * always equal when the other bytes match, given that the hash keys
1336 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1337 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1338 * lookahead only every 4th comparison; the 128th check will be made
1339 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1340 * necessary to put more guard bytes at the end of the window, or
1341 * to check more often for insufficient lookahead.
1343 Assert(scan[2] == match[2], "scan[2]?");
1346 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1347 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1348 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1349 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1351 /* The funny "do {}" generates better code on most compilers */
1353 /* Here, scan <= window+strstart+257 */
1354 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1355 if (*scan == *match) scan++;
1357 len = (MAX_MATCH - 1) - (int)(strend-scan);
1358 scan = strend - (MAX_MATCH-1);
1360 #else /* UNALIGNED_OK */
1362 if (match[best_len] != scan_end ||
1363 match[best_len-1] != scan_end1 ||
1365 *++match != scan[1]) continue;
1367 /* The check at best_len-1 can be removed because it will be made
1368 * again later. (This heuristic is not always a win.)
1369 * It is not necessary to compare scan[2] and match[2] since they
1370 * are always equal when the other bytes match, given that
1371 * the hash keys are equal and that HASH_BITS >= 8.
1374 Assert(*scan == *match, "match[2]?");
1376 /* We check for insufficient lookahead only every 8th comparison;
1377 * the 256th check will be made at strstart+258.
1380 } while (*++scan == *++match && *++scan == *++match &&
1381 *++scan == *++match && *++scan == *++match &&
1382 *++scan == *++match && *++scan == *++match &&
1383 *++scan == *++match && *++scan == *++match &&
1386 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1388 len = MAX_MATCH - (int)(strend - scan);
1389 scan = strend - MAX_MATCH;
1391 #endif /* UNALIGNED_OK */
1393 if (len > best_len) {
1394 s->match_start = cur_match;
1396 if (len >= nice_match) break;
1398 scan_end = *(ushf*)(scan+best_len-1);
1400 scan_end1 = scan[best_len-1];
1401 scan_end = scan[best_len];
1404 } while ((cur_match = prev[cur_match & wmask]) > limit
1405 && --chain_length != 0);
1407 if ((uInt)best_len <= s->lookahead) return best_len;
1408 return s->lookahead;
1413 /* ===========================================================================
1414 * Check that the match at match_start is indeed a match.
1416 local void check_match(s, start, match, length)
1421 /* check that the match is indeed a match */
1422 if (zmemcmp((charf *)s->window + match,
1423 (charf *)s->window + start, length) != EQUAL) {
1424 fprintf(stderr, " start %u, match %u, length %d\n",
1425 start, match, length);
1427 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1428 } while (--length != 0);
1429 z_error("invalid match");
1431 if (z_verbose > 1) {
1432 fprintf(stderr,"\\[%d,%d]", start-match, length);
1433 do { putc(s->window[start++], stderr); } while (--length != 0);
1437 # define check_match(s, start, match, length)
1440 /* ===========================================================================
1441 * Fill the window when the lookahead becomes insufficient.
1442 * Updates strstart and lookahead.
1444 * IN assertion: lookahead < MIN_LOOKAHEAD
1445 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1446 * At least one byte has been read, or avail_in == 0; reads are
1447 * performed for at least two bytes (required for the zip translate_eol
1448 * option -- not supported here).
1450 local void fill_window(s)
1453 register unsigned n, m;
1455 unsigned more; /* Amount of free space at the end of the window. */
1456 uInt wsize = s->w_size;
1459 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1461 /* Deal with !@#$% 64K limit: */
1462 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1465 } else if (more == (unsigned)(-1)) {
1466 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1467 * and lookahead == 1 (input done one byte at time)
1471 /* If the window is almost full and there is insufficient lookahead,
1472 * move the upper half to the lower one to make room in the upper half.
1474 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1476 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1478 s->match_start -= wsize;
1479 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1480 s->block_start -= (long) wsize;
1482 /* Slide the hash table (could be avoided with 32 bit values
1483 at the expense of memory usage). We slide even when level == 0
1484 to keep the hash table consistent if we switch back to level > 0
1485 later. (Using level 0 permanently is not an optimal usage of
1486 zlib, so we don't care about this pathological case.)
1492 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1499 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1500 /* If n is not on any hash chain, prev[n] is garbage but
1501 * its value will never be used.
1506 if (s->strm->avail_in == 0) return;
1508 /* If there was no sliding:
1509 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1510 * more == window_size - lookahead - strstart
1511 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1512 * => more >= window_size - 2*WSIZE + 2
1513 * In the BIG_MEM or MMAP case (not yet supported),
1514 * window_size == input_size + MIN_LOOKAHEAD &&
1515 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1516 * Otherwise, window_size == 2*WSIZE so more >= 2.
1517 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1519 Assert(more >= 2, "more < 2");
1521 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1525 /* Initialize the hash value now that we have some input: */
1526 if (s->lookahead >= MIN_MATCH) {
1527 s->ins_h = s->window[s->strstart];
1528 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1530 Call UPDATE_HASH() MIN_MATCH-3 more times
1533 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1534 * but this is not important since only literal bytes will be emitted.
1537 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1540 /* ===========================================================================
1541 * Flush the current block, with given end-of-file flag.
1542 * IN assertion: strstart is set to the end of the current match.
1544 #define FLUSH_BLOCK_ONLY(s, eof) { \
1545 _tr_flush_block(s, (s->block_start >= 0L ? \
1546 (charf *)&s->window[(unsigned)s->block_start] : \
1548 (ulg)((long)s->strstart - s->block_start), \
1550 s->block_start = s->strstart; \
1551 flush_pending(s->strm); \
1552 Tracev((stderr,"[FLUSH]")); \
1555 /* Same but force premature exit if necessary. */
1556 #define FLUSH_BLOCK(s, eof) { \
1557 FLUSH_BLOCK_ONLY(s, eof); \
1558 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1561 /* ===========================================================================
1562 * Copy without compression as much as possible from the input stream, return
1563 * the current block state.
1564 * This function does not insert new strings in the dictionary since
1565 * uncompressible data is probably not useful. This function is used
1566 * only for the level=0 compression option.
1567 * NOTE: this function should be optimized to avoid extra copying from
1568 * window to pending_buf.
1570 local block_state deflate_stored(s, flush)
1574 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1575 * to pending_buf_size, and each stored block has a 5 byte header:
1577 ulg max_block_size = 0xffff;
1580 if (max_block_size > s->pending_buf_size - 5) {
1581 max_block_size = s->pending_buf_size - 5;
1584 /* Copy as much as possible from input to output: */
1586 /* Fill the window as much as possible: */
1587 if (s->lookahead <= 1) {
1589 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1590 s->block_start >= (long)s->w_size, "slide too late");
1593 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1595 if (s->lookahead == 0) break; /* flush the current block */
1597 Assert(s->block_start >= 0L, "block gone");
1599 s->strstart += s->lookahead;
1602 /* Emit a stored block if pending_buf will be full: */
1603 max_start = s->block_start + max_block_size;
1604 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1605 /* strstart == 0 is possible when wraparound on 16-bit machine */
1606 s->lookahead = (uInt)(s->strstart - max_start);
1607 s->strstart = (uInt)max_start;
1610 /* Flush if we may have to slide, otherwise block_start may become
1611 * negative and the data will be gone:
1613 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1617 FLUSH_BLOCK(s, flush == Z_FINISH);
1618 return flush == Z_FINISH ? finish_done : block_done;
1621 /* ===========================================================================
1622 * Compress as much as possible from the input stream, return the current
1624 * This function does not perform lazy evaluation of matches and inserts
1625 * new strings in the dictionary only for unmatched strings or for short
1626 * matches. It is used only for the fast compression options.
1628 local block_state deflate_fast(s, flush)
1632 IPos hash_head = NIL; /* head of the hash chain */
1633 int bflush; /* set if current block must be flushed */
1636 /* Make sure that we always have enough lookahead, except
1637 * at the end of the input file. We need MAX_MATCH bytes
1638 * for the next match, plus MIN_MATCH bytes to insert the
1639 * string following the next match.
1641 if (s->lookahead < MIN_LOOKAHEAD) {
1643 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1646 if (s->lookahead == 0) break; /* flush the current block */
1649 /* Insert the string window[strstart .. strstart+2] in the
1650 * dictionary, and set hash_head to the head of the hash chain:
1652 if (s->lookahead >= MIN_MATCH) {
1653 INSERT_STRING(s, s->strstart, hash_head);
1656 /* Find the longest match, discarding those <= prev_length.
1657 * At this point we have always match_length < MIN_MATCH
1659 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1660 /* To simplify the code, we prevent matches with the string
1661 * of window index 0 (in particular we have to avoid a match
1662 * of the string with itself at the start of the input file).
1664 if (s->strategy != Z_HUFFMAN_ONLY) {
1665 s->match_length = longest_match (s, hash_head);
1667 /* longest_match() sets match_start */
1669 if (s->match_length >= MIN_MATCH) {
1670 check_match(s, s->strstart, s->match_start, s->match_length);
1672 bflush = _tr_tally(s, s->strstart - s->match_start,
1673 s->match_length - MIN_MATCH);
1675 s->lookahead -= s->match_length;
1677 /* Insert new strings in the hash table only if the match length
1678 * is not too large. This saves time but degrades compression.
1680 if (s->match_length <= s->max_insert_length &&
1681 s->lookahead >= MIN_MATCH) {
1682 s->match_length--; /* string at strstart already in hash table */
1685 INSERT_STRING(s, s->strstart, hash_head);
1686 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1687 * always MIN_MATCH bytes ahead.
1689 } while (--s->match_length != 0);
1692 s->strstart += s->match_length;
1693 s->match_length = 0;
1694 s->ins_h = s->window[s->strstart];
1695 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1697 Call UPDATE_HASH() MIN_MATCH-3 more times
1699 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1700 * matter since it will be recomputed at next deflate call.
1704 /* No match, output a literal byte */
1705 Tracevv((stderr,"%c", s->window[s->strstart]));
1706 bflush = _tr_tally (s, 0, s->window[s->strstart]);
1710 if (bflush) FLUSH_BLOCK(s, 0);
1712 FLUSH_BLOCK(s, flush == Z_FINISH);
1713 return flush == Z_FINISH ? finish_done : block_done;
1716 /* ===========================================================================
1717 * Same as above, but achieves better compression. We use a lazy
1718 * evaluation for matches: a match is finally adopted only if there is
1719 * no better match at the next window position.
1721 local block_state deflate_slow(s, flush)
1725 IPos hash_head = NIL; /* head of hash chain */
1726 int bflush; /* set if current block must be flushed */
1728 /* Process the input block. */
1730 /* Make sure that we always have enough lookahead, except
1731 * at the end of the input file. We need MAX_MATCH bytes
1732 * for the next match, plus MIN_MATCH bytes to insert the
1733 * string following the next match.
1735 if (s->lookahead < MIN_LOOKAHEAD) {
1737 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1740 if (s->lookahead == 0) break; /* flush the current block */
1743 /* Insert the string window[strstart .. strstart+2] in the
1744 * dictionary, and set hash_head to the head of the hash chain:
1746 if (s->lookahead >= MIN_MATCH) {
1747 INSERT_STRING(s, s->strstart, hash_head);
1750 /* Find the longest match, discarding those <= prev_length.
1752 s->prev_length = s->match_length, s->prev_match = s->match_start;
1753 s->match_length = MIN_MATCH-1;
1755 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1756 s->strstart - hash_head <= MAX_DIST(s)) {
1757 /* To simplify the code, we prevent matches with the string
1758 * of window index 0 (in particular we have to avoid a match
1759 * of the string with itself at the start of the input file).
1761 if (s->strategy != Z_HUFFMAN_ONLY) {
1762 s->match_length = longest_match (s, hash_head);
1764 /* longest_match() sets match_start */
1766 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1767 (s->match_length == MIN_MATCH &&
1768 s->strstart - s->match_start > TOO_FAR))) {
1770 /* If prev_match is also MIN_MATCH, match_start is garbage
1771 * but we will ignore the current match anyway.
1773 s->match_length = MIN_MATCH-1;
1776 /* If there was a match at the previous step and the current
1777 * match is not better, output the previous match:
1779 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1780 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1781 /* Do not insert strings in hash table beyond this. */
1783 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1785 bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
1786 s->prev_length - MIN_MATCH);
1788 /* Insert in hash table all strings up to the end of the match.
1789 * strstart-1 and strstart are already inserted. If there is not
1790 * enough lookahead, the last two strings are not inserted in
1793 s->lookahead -= s->prev_length-1;
1794 s->prev_length -= 2;
1796 if (++s->strstart <= max_insert) {
1797 INSERT_STRING(s, s->strstart, hash_head);
1799 } while (--s->prev_length != 0);
1800 s->match_available = 0;
1801 s->match_length = MIN_MATCH-1;
1804 if (bflush) FLUSH_BLOCK(s, 0);
1806 } else if (s->match_available) {
1807 /* If there was no match at the previous position, output a
1808 * single literal. If there was a match but the current match
1809 * is longer, truncate the previous match to a single literal.
1811 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1812 if (_tr_tally (s, 0, s->window[s->strstart-1])) {
1813 FLUSH_BLOCK_ONLY(s, 0);
1817 if (s->strm->avail_out == 0) return need_more;
1819 /* There is no previous match to compare with, wait for
1820 * the next step to decide.
1822 s->match_available = 1;
1827 Assert (flush != Z_NO_FLUSH, "no flush?");
1828 if (s->match_available) {
1829 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1830 _tr_tally (s, 0, s->window[s->strstart-1]);
1831 s->match_available = 0;
1833 FLUSH_BLOCK(s, flush == Z_FINISH);
1834 return flush == Z_FINISH ? finish_done : block_done;
1839 /* trees.c -- output deflated data using Huffman coding
1840 * Copyright (C) 1995-1996 Jean-loup Gailly
1841 * For conditions of distribution and use, see copyright notice in zlib.h
1847 * The "deflation" process uses several Huffman trees. The more
1848 * common source values are represented by shorter bit sequences.
1850 * Each code tree is stored in a compressed form which is itself
1851 * a Huffman encoding of the lengths of all the code strings (in
1852 * ascending order by source values). The actual code strings are
1853 * reconstructed from the lengths in the inflate process, as described
1854 * in the deflate specification.
1858 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1859 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1862 * Data Compression: Methods and Theory, pp. 49-50.
1863 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1867 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1870 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
1872 /* #include "deflate.h" */
1878 /* ===========================================================================
1882 #define MAX_BL_BITS 7
1883 /* Bit length codes must not exceed MAX_BL_BITS bits */
1885 #define END_BLOCK 256
1886 /* end of block literal code */
1889 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1891 #define REPZ_3_10 17
1892 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1894 #define REPZ_11_138 18
1895 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1897 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1898 = {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};
1900 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1901 = {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};
1903 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1904 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1906 local uch bl_order[BL_CODES]
1907 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1908 /* The lengths of the bit length codes are sent in order of decreasing
1909 * probability, to avoid transmitting the lengths for unused bit length codes.
1912 #define Buf_size (8 * 2*sizeof(char))
1913 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1914 * more than 16 bits on some systems.)
1917 /* ===========================================================================
1918 * Local data. These are initialized only once.
1921 local ct_data static_ltree[L_CODES+2];
1922 /* The static literal tree. Since the bit lengths are imposed, there is no
1923 * need for the L_CODES extra codes used during heap construction. However
1924 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
1928 local ct_data static_dtree[D_CODES];
1929 /* The static distance tree. (Actually a trivial tree since all codes use
1933 local uch dist_code[512];
1934 /* distance codes. The first 256 values correspond to the distances
1935 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1936 * the 15 bit distances.
1939 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1940 /* length code for each normalized match length (0 == MIN_MATCH) */
1942 local int base_length[LENGTH_CODES];
1943 /* First normalized length for each code (0 = MIN_MATCH) */
1945 local int base_dist[D_CODES];
1946 /* First normalized distance for each code (0 = distance of 1) */
1948 struct static_tree_desc_s {
1949 ct_data *static_tree; /* static tree or NULL */
1950 intf *extra_bits; /* extra bits for each code or NULL */
1951 int extra_base; /* base index for extra_bits */
1952 int elems; /* max number of elements in the tree */
1953 int max_length; /* max bit length for the codes */
1956 local static_tree_desc static_l_desc =
1957 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1959 local static_tree_desc static_d_desc =
1960 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1962 local static_tree_desc static_bl_desc =
1963 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1965 /* ===========================================================================
1966 * Local (static) routines in this file.
1969 local void tr_static_init OF((void));
1970 local void init_block OF((deflate_state *s));
1971 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1972 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1973 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1974 local void build_tree OF((deflate_state *s, tree_desc *desc));
1975 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1976 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1977 local int build_bl_tree OF((deflate_state *s));
1978 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1980 local void compress_block OF((deflate_state *s, ct_data *ltree,
1982 local void set_data_type OF((deflate_state *s));
1983 local unsigned bi_reverse OF((unsigned value, int length));
1984 local void bi_windup OF((deflate_state *s));
1985 local void bi_flush OF((deflate_state *s));
1986 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1990 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1991 /* Send a code of the given tree. c and tree must not have side effects */
1993 #else /* DEBUG_ZLIB */
1994 # define send_code(s, c, tree) \
1995 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
1996 send_bits(s, tree[c].Code, tree[c].Len); }
1999 #define d_code(dist) \
2000 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
2001 /* Mapping from a distance to a distance code. dist is the distance - 1 and
2002 * must not have side effects. dist_code[256] and dist_code[257] are never
2006 /* ===========================================================================
2007 * Output a short LSB first on the stream.
2008 * IN assertion: there is enough room in pendingBuf.
2010 #define put_short(s, w) { \
2011 put_byte(s, (uch)((w) & 0xff)); \
2012 put_byte(s, (uch)((ush)(w) >> 8)); \
2015 /* ===========================================================================
2016 * Send a value on a given number of bits.
2017 * IN assertion: length <= 16 and value fits in length bits.
2020 local void send_bits OF((deflate_state *s, int value, int length));
2022 local void send_bits(s, value, length)
2024 int value; /* value to send */
2025 int length; /* number of bits */
2027 Tracevv((stderr," l %2d v %4x ", length, value));
2028 Assert(length > 0 && length <= 15, "invalid length");
2029 s->bits_sent += (ulg)length;
2031 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2032 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2033 * unused bits in value.
2035 if (s->bi_valid > (int)Buf_size - length) {
2036 s->bi_buf |= (value << s->bi_valid);
2037 put_short(s, s->bi_buf);
2038 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2039 s->bi_valid += length - Buf_size;
2041 s->bi_buf |= value << s->bi_valid;
2042 s->bi_valid += length;
2045 #else /* !DEBUG_ZLIB */
2047 #define send_bits(s, value, length) \
2048 { int len = length;\
2049 if (s->bi_valid > (int)Buf_size - len) {\
2051 s->bi_buf |= (val << s->bi_valid);\
2052 put_short(s, s->bi_buf);\
2053 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2054 s->bi_valid += len - Buf_size;\
2056 s->bi_buf |= (value) << s->bi_valid;\
2057 s->bi_valid += len;\
2060 #endif /* DEBUG_ZLIB */
2063 #define MAX(a,b) (a >= b ? a : b)
2064 /* the arguments must not have side effects */
2066 /* ===========================================================================
2067 * Initialize the various 'constant' tables. In a multi-threaded environment,
2068 * this function may be called by two threads concurrently, but this is
2069 * harmless since both invocations do exactly the same thing.
2071 local void tr_static_init()
2073 static int static_init_done = 0;
2074 int n; /* iterates over tree elements */
2075 int bits; /* bit counter */
2076 int length; /* length value */
2077 int code; /* code value */
2078 int dist; /* distance index */
2079 ush bl_count[MAX_BITS+1];
2080 /* number of codes at each bit length for an optimal tree */
2082 if (static_init_done) return;
2084 /* Initialize the mapping length (0..255) -> length code (0..28) */
2086 for (code = 0; code < LENGTH_CODES-1; code++) {
2087 base_length[code] = length;
2088 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2089 length_code[length++] = (uch)code;
2092 Assert (length == 256, "tr_static_init: length != 256");
2093 /* Note that the length 255 (match length 258) can be represented
2094 * in two different ways: code 284 + 5 bits or code 285, so we
2095 * overwrite length_code[255] to use the best encoding:
2097 length_code[length-1] = (uch)code;
2099 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2101 for (code = 0 ; code < 16; code++) {
2102 base_dist[code] = dist;
2103 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2104 dist_code[dist++] = (uch)code;
2107 Assert (dist == 256, "tr_static_init: dist != 256");
2108 dist >>= 7; /* from now on, all distances are divided by 128 */
2109 for ( ; code < D_CODES; code++) {
2110 base_dist[code] = dist << 7;
2111 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2112 dist_code[256 + dist++] = (uch)code;
2115 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2117 /* Construct the codes of the static literal tree */
2118 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2120 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2121 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2122 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2123 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2124 /* Codes 286 and 287 do not exist, but we must include them in the
2125 * tree construction to get a canonical Huffman tree (longest code
2128 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2130 /* The static distance tree is trivial: */
2131 for (n = 0; n < D_CODES; n++) {
2132 static_dtree[n].Len = 5;
2133 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2135 static_init_done = 1;
2138 /* ===========================================================================
2139 * Initialize the tree data structures for a new zlib stream.
2146 s->compressed_len = 0L;
2148 s->l_desc.dyn_tree = s->dyn_ltree;
2149 s->l_desc.stat_desc = &static_l_desc;
2151 s->d_desc.dyn_tree = s->dyn_dtree;
2152 s->d_desc.stat_desc = &static_d_desc;
2154 s->bl_desc.dyn_tree = s->bl_tree;
2155 s->bl_desc.stat_desc = &static_bl_desc;
2159 s->last_eob_len = 8; /* enough lookahead for inflate */
2164 /* Initialize the first block of the first file: */
2168 /* ===========================================================================
2169 * Initialize a new block.
2171 local void init_block(s)
2174 int n; /* iterates over tree elements */
2176 /* Initialize the trees. */
2177 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2178 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2179 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2181 s->dyn_ltree[END_BLOCK].Freq = 1;
2182 s->opt_len = s->static_len = 0L;
2183 s->last_lit = s->matches = 0;
2187 /* Index within the heap array of least frequent node in the Huffman tree */
2190 /* ===========================================================================
2191 * Remove the smallest element from the heap and recreate the heap with
2192 * one less element. Updates heap and heap_len.
2194 #define pqremove(s, tree, top) \
2196 top = s->heap[SMALLEST]; \
2197 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2198 pqdownheap(s, tree, SMALLEST); \
2201 /* ===========================================================================
2202 * Compares to subtrees, using the tree depth as tie breaker when
2203 * the subtrees have equal frequency. This minimizes the worst case length.
2205 #define smaller(tree, n, m, depth) \
2206 (tree[n].Freq < tree[m].Freq || \
2207 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2209 /* ===========================================================================
2210 * Restore the heap property by moving down the tree starting at node k,
2211 * exchanging a node with the smallest of its two sons if necessary, stopping
2212 * when the heap property is re-established (each father smaller than its
2215 local void pqdownheap(s, tree, k)
2217 ct_data *tree; /* the tree to restore */
2218 int k; /* node to move down */
2221 int j = k << 1; /* left son of k */
2222 while (j <= s->heap_len) {
2223 /* Set j to the smallest of the two sons: */
2224 if (j < s->heap_len &&
2225 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2228 /* Exit if v is smaller than both sons */
2229 if (smaller(tree, v, s->heap[j], s->depth)) break;
2231 /* Exchange v with the smallest son */
2232 s->heap[k] = s->heap[j]; k = j;
2234 /* And continue down the tree, setting j to the left son of k */
2240 /* ===========================================================================
2241 * Compute the optimal bit lengths for a tree and update the total bit length
2242 * for the current block.
2243 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2244 * above are the tree nodes sorted by increasing frequency.
2245 * OUT assertions: the field len is set to the optimal bit length, the
2246 * array bl_count contains the frequencies for each bit length.
2247 * The length opt_len is updated; static_len is also updated if stree is
2250 local void gen_bitlen(s, desc)
2252 tree_desc *desc; /* the tree descriptor */
2254 ct_data *tree = desc->dyn_tree;
2255 int max_code = desc->max_code;
2256 ct_data *stree = desc->stat_desc->static_tree;
2257 intf *extra = desc->stat_desc->extra_bits;
2258 int base = desc->stat_desc->extra_base;
2259 int max_length = desc->stat_desc->max_length;
2260 int h; /* heap index */
2261 int n, m; /* iterate over the tree elements */
2262 int bits; /* bit length */
2263 int xbits; /* extra bits */
2264 ush f; /* frequency */
2265 int overflow = 0; /* number of elements with bit length too large */
2267 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2269 /* In a first pass, compute the optimal bit lengths (which may
2270 * overflow in the case of the bit length tree).
2272 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2274 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2276 bits = tree[tree[n].Dad].Len + 1;
2277 if (bits > max_length) bits = max_length, overflow++;
2278 tree[n].Len = (ush)bits;
2279 /* We overwrite tree[n].Dad which is no longer needed */
2281 if (n > max_code) continue; /* not a leaf node */
2283 s->bl_count[bits]++;
2285 if (n >= base) xbits = extra[n-base];
2287 s->opt_len += (ulg)f * (bits + xbits);
2288 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2290 if (overflow == 0) return;
2292 Trace((stderr,"\nbit length overflow\n"));
2293 /* This happens for example on obj2 and pic of the Calgary corpus */
2295 /* Find the first bit length which could increase: */
2297 bits = max_length-1;
2298 while (s->bl_count[bits] == 0) bits--;
2299 s->bl_count[bits]--; /* move one leaf down the tree */
2300 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2301 s->bl_count[max_length]--;
2302 /* The brother of the overflow item also moves one step up,
2303 * but this does not affect bl_count[max_length]
2306 } while (overflow > 0);
2308 /* Now recompute all bit lengths, scanning in increasing frequency.
2309 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2310 * lengths instead of fixing only the wrong ones. This idea is taken
2311 * from 'ar' written by Haruhiko Okumura.)
2313 for (bits = max_length; bits != 0; bits--) {
2314 n = s->bl_count[bits];
2317 if (m > max_code) continue;
2318 if (tree[m].Len != (unsigned) bits) {
2319 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2320 s->opt_len += ((long)bits - (long)tree[m].Len)
2321 *(long)tree[m].Freq;
2322 tree[m].Len = (ush)bits;
2329 /* ===========================================================================
2330 * Generate the codes for a given tree and bit counts (which need not be
2332 * IN assertion: the array bl_count contains the bit length statistics for
2333 * the given tree and the field len is set for all tree elements.
2334 * OUT assertion: the field code is set for all tree elements of non
2337 local void gen_codes (tree, max_code, bl_count)
2338 ct_data *tree; /* the tree to decorate */
2339 int max_code; /* largest code with non zero frequency */
2340 ushf *bl_count; /* number of codes at each bit length */
2342 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2343 ush code = 0; /* running code value */
2344 int bits; /* bit index */
2345 int n; /* code index */
2347 /* The distribution counts are first used to generate the code values
2348 * without bit reversal.
2350 for (bits = 1; bits <= MAX_BITS; bits++) {
2351 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2353 /* Check that the bit counts in bl_count are consistent. The last code
2356 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2357 "inconsistent bit counts");
2358 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2360 for (n = 0; n <= max_code; n++) {
2361 int len = tree[n].Len;
2362 if (len == 0) continue;
2363 /* Now reverse the bits */
2364 tree[n].Code = bi_reverse(next_code[len]++, len);
2366 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2367 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2371 /* ===========================================================================
2372 * Construct one Huffman tree and assigns the code bit strings and lengths.
2373 * Update the total bit length for the current block.
2374 * IN assertion: the field freq is set for all tree elements.
2375 * OUT assertions: the fields len and code are set to the optimal bit length
2376 * and corresponding code. The length opt_len is updated; static_len is
2377 * also updated if stree is not null. The field max_code is set.
2379 local void build_tree(s, desc)
2381 tree_desc *desc; /* the tree descriptor */
2383 ct_data *tree = desc->dyn_tree;
2384 ct_data *stree = desc->stat_desc->static_tree;
2385 int elems = desc->stat_desc->elems;
2386 int n, m; /* iterate over heap elements */
2387 int max_code = -1; /* largest code with non zero frequency */
2388 int node; /* new node being created */
2390 /* Construct the initial heap, with least frequent element in
2391 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2392 * heap[0] is not used.
2394 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2396 for (n = 0; n < elems; n++) {
2397 if (tree[n].Freq != 0) {
2398 s->heap[++(s->heap_len)] = max_code = n;
2405 /* The pkzip format requires that at least one distance code exists,
2406 * and that at least one bit should be sent even if there is only one
2407 * possible code. So to avoid special checks later on we force at least
2408 * two codes of non zero frequency.
2410 while (s->heap_len < 2) {
2411 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2412 tree[node].Freq = 1;
2414 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2415 /* node is 0 or 1 so it does not have extra bits */
2417 desc->max_code = max_code;
2419 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2420 * establish sub-heaps of increasing lengths:
2422 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2424 /* Construct the Huffman tree by repeatedly combining the least two
2427 node = elems; /* next internal node of the tree */
2429 pqremove(s, tree, n); /* n = node of least frequency */
2430 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2432 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2433 s->heap[--(s->heap_max)] = m;
2435 /* Create a new node father of n and m */
2436 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2437 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2438 tree[n].Dad = tree[m].Dad = (ush)node;
2440 if (tree == s->bl_tree) {
2441 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2442 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2445 /* and insert the new node in the heap */
2446 s->heap[SMALLEST] = node++;
2447 pqdownheap(s, tree, SMALLEST);
2449 } while (s->heap_len >= 2);
2451 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2453 /* At this point, the fields freq and dad are set. We can now
2454 * generate the bit lengths.
2456 gen_bitlen(s, (tree_desc *)desc);
2458 /* The field len is now set, we can generate the bit codes */
2459 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2462 /* ===========================================================================
2463 * Scan a literal or distance tree to determine the frequencies of the codes
2464 * in the bit length tree.
2466 local void scan_tree (s, tree, max_code)
2468 ct_data *tree; /* the tree to be scanned */
2469 int max_code; /* and its largest code of non zero frequency */
2471 int n; /* iterates over all tree elements */
2472 int prevlen = -1; /* last emitted length */
2473 int curlen; /* length of current code */
2474 int nextlen = tree[0].Len; /* length of next code */
2475 int count = 0; /* repeat count of the current code */
2476 int max_count = 7; /* max repeat count */
2477 int min_count = 4; /* min repeat count */
2479 if (nextlen == 0) max_count = 138, min_count = 3;
2480 tree[max_code+1].Len = (ush)0xffff; /* guard */
2482 for (n = 0; n <= max_code; n++) {
2483 curlen = nextlen; nextlen = tree[n+1].Len;
2484 if (++count < max_count && curlen == nextlen) {
2486 } else if (count < min_count) {
2487 s->bl_tree[curlen].Freq += count;
2488 } else if (curlen != 0) {
2489 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2490 s->bl_tree[REP_3_6].Freq++;
2491 } else if (count <= 10) {
2492 s->bl_tree[REPZ_3_10].Freq++;
2494 s->bl_tree[REPZ_11_138].Freq++;
2496 count = 0; prevlen = curlen;
2498 max_count = 138, min_count = 3;
2499 } else if (curlen == nextlen) {
2500 max_count = 6, min_count = 3;
2502 max_count = 7, min_count = 4;
2507 /* ===========================================================================
2508 * Send a literal or distance tree in compressed form, using the codes in
2511 local void send_tree (s, tree, max_code)
2513 ct_data *tree; /* the tree to be scanned */
2514 int max_code; /* and its largest code of non zero frequency */
2516 int n; /* iterates over all tree elements */
2517 int prevlen = -1; /* last emitted length */
2518 int curlen; /* length of current code */
2519 int nextlen = tree[0].Len; /* length of next code */
2520 int count = 0; /* repeat count of the current code */
2521 int max_count = 7; /* max repeat count */
2522 int min_count = 4; /* min repeat count */
2524 /* tree[max_code+1].Len = -1; */ /* guard already set */
2525 if (nextlen == 0) max_count = 138, min_count = 3;
2527 for (n = 0; n <= max_code; n++) {
2528 curlen = nextlen; nextlen = tree[n+1].Len;
2529 if (++count < max_count && curlen == nextlen) {
2531 } else if (count < min_count) {
2532 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2534 } else if (curlen != 0) {
2535 if (curlen != prevlen) {
2536 send_code(s, curlen, s->bl_tree); count--;
2538 Assert(count >= 3 && count <= 6, " 3_6?");
2539 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2541 } else if (count <= 10) {
2542 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2545 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2547 count = 0; prevlen = curlen;
2549 max_count = 138, min_count = 3;
2550 } else if (curlen == nextlen) {
2551 max_count = 6, min_count = 3;
2553 max_count = 7, min_count = 4;
2558 /* ===========================================================================
2559 * Construct the Huffman tree for the bit lengths and return the index in
2560 * bl_order of the last bit length code to send.
2562 local int build_bl_tree(s)
2565 int max_blindex; /* index of last bit length code of non zero freq */
2567 /* Determine the bit length frequencies for literal and distance trees */
2568 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2569 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2571 /* Build the bit length tree: */
2572 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2573 /* opt_len now includes the length of the tree representations, except
2574 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2577 /* Determine the number of bit length codes to send. The pkzip format
2578 * requires that at least 4 bit length codes be sent. (appnote.txt says
2579 * 3 but the actual value used is 4.)
2581 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2582 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2584 /* Update opt_len to include the bit length tree and counts */
2585 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2586 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2587 s->opt_len, s->static_len));
2592 /* ===========================================================================
2593 * Send the header for a block using dynamic Huffman trees: the counts, the
2594 * lengths of the bit length codes, the literal tree and the distance tree.
2595 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2597 local void send_all_trees(s, lcodes, dcodes, blcodes)
2599 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2601 int rank; /* index in bl_order */
2603 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2604 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2606 Tracev((stderr, "\nbl counts: "));
2607 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2608 send_bits(s, dcodes-1, 5);
2609 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2610 for (rank = 0; rank < blcodes; rank++) {
2611 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2612 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2614 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2616 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2617 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2619 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2620 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2623 /* ===========================================================================
2624 * Send a stored block
2626 void _tr_stored_block(s, buf, stored_len, eof)
2628 charf *buf; /* input block */
2629 ulg stored_len; /* length of input block */
2630 int eof; /* true if this is the last block for a file */
2632 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2633 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
2634 s->compressed_len += (stored_len + 4) << 3;
2636 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2639 /* Send just the `stored block' type code without any length bytes or data.
2641 void _tr_stored_type_only(s)
2644 send_bits(s, (STORED_BLOCK << 1), 3);
2646 s->compressed_len = (s->compressed_len + 3) & ~7L;
2650 /* ===========================================================================
2651 * Send one empty static block to give enough lookahead for inflate.
2652 * This takes 10 bits, of which 7 may remain in the bit buffer.
2653 * The current inflate code requires 9 bits of lookahead. If the
2654 * last two codes for the previous block (real code plus EOB) were coded
2655 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
2656 * the last real code. In this case we send two empty static blocks instead
2657 * of one. (There are no problems if the previous block is stored or fixed.)
2658 * To simplify the code, we assume the worst case of last real code encoded
2664 send_bits(s, STATIC_TREES<<1, 3);
2665 send_code(s, END_BLOCK, static_ltree);
2666 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2668 /* Of the 10 bits for the empty block, we have already sent
2669 * (10 - bi_valid) bits. The lookahead for the last real code (before
2670 * the EOB of the previous block) was thus at least one plus the length
2671 * of the EOB plus what we have just sent of the empty static block.
2673 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
2674 send_bits(s, STATIC_TREES<<1, 3);
2675 send_code(s, END_BLOCK, static_ltree);
2676 s->compressed_len += 10L;
2679 s->last_eob_len = 7;
2682 /* ===========================================================================
2683 * Determine the best encoding for the current block: dynamic trees, static
2684 * trees or store, and output the encoded block to the zip file. This function
2685 * returns the total compressed length for the file so far.
2687 ulg _tr_flush_block(s, buf, stored_len, eof)
2689 charf *buf; /* input block, or NULL if too old */
2690 ulg stored_len; /* length of input block */
2691 int eof; /* true if this is the last block for a file */
2693 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2694 int max_blindex = 0; /* index of last bit length code of non zero freq */
2696 /* Build the Huffman trees unless a stored block is forced */
2699 /* Check if the file is ascii or binary */
2700 if (s->data_type == Z_UNKNOWN) set_data_type(s);
2702 /* Construct the literal and distance trees */
2703 build_tree(s, (tree_desc *)(&(s->l_desc)));
2704 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2707 build_tree(s, (tree_desc *)(&(s->d_desc)));
2708 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2710 /* At this point, opt_len and static_len are the total bit lengths of
2711 * the compressed block data, excluding the tree representations.
2714 /* Build the bit length tree for the above two trees, and get the index
2715 * in bl_order of the last bit length code to send.
2717 max_blindex = build_bl_tree(s);
2719 /* Determine the best encoding. Compute first the block length in bytes*/
2720 opt_lenb = (s->opt_len+3+7)>>3;
2721 static_lenb = (s->static_len+3+7)>>3;
2723 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2724 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2727 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2730 Assert(buf != (char*)0, "lost buf");
2731 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
2734 /* If compression failed and this is the first and last block,
2735 * and if the .zip file can be seeked (to rewrite the local header),
2736 * the whole file is transformed into a stored file:
2738 #ifdef STORED_FILE_OK
2739 # ifdef FORCE_STORED_FILE
2740 if (eof && s->compressed_len == 0L) { /* force stored file */
2742 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
2744 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2745 if (buf == (charf*)0) error ("block vanished");
2747 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
2748 s->compressed_len = stored_len << 3;
2751 #endif /* STORED_FILE_OK */
2754 if (buf != (char*)0) { /* force stored block */
2756 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2757 /* 4: two words for the lengths */
2759 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2760 * Otherwise we can't have processed more than WSIZE input bytes since
2761 * the last block flush, because compression would have been
2762 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2763 * transform a block into a stored block.
2765 _tr_stored_block(s, buf, stored_len, eof);
2768 } else if (static_lenb >= 0) { /* force static trees */
2770 } else if (static_lenb == opt_lenb) {
2772 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2773 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2774 s->compressed_len += 3 + s->static_len;
2776 send_bits(s, (DYN_TREES<<1)+eof, 3);
2777 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2779 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2780 s->compressed_len += 3 + s->opt_len;
2782 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2787 s->compressed_len += 7; /* align on byte boundary */
2789 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2790 s->compressed_len-7*eof));
2792 return s->compressed_len >> 3;
2795 /* ===========================================================================
2796 * Save the match info and tally the frequency counts. Return true if
2797 * the current block must be flushed.
2799 int _tr_tally (s, dist, lc)
2801 unsigned dist; /* distance of matched string */
2802 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2804 s->d_buf[s->last_lit] = (ush)dist;
2805 s->l_buf[s->last_lit++] = (uch)lc;
2807 /* lc is the unmatched char */
2808 s->dyn_ltree[lc].Freq++;
2811 /* Here, lc is the match length - MIN_MATCH */
2812 dist--; /* dist = match distance - 1 */
2813 Assert((ush)dist < (ush)MAX_DIST(s) &&
2814 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2815 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
2817 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2818 s->dyn_dtree[d_code(dist)].Freq++;
2821 /* Try to guess if it is profitable to stop the current block here */
2822 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2823 /* Compute an upper bound for the compressed length */
2824 ulg out_length = (ulg)s->last_lit*8L;
2825 ulg in_length = (ulg)((long)s->strstart - s->block_start);
2827 for (dcode = 0; dcode < D_CODES; dcode++) {
2828 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2829 (5L+extra_dbits[dcode]);
2832 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2833 s->last_lit, in_length, out_length,
2834 100L - out_length*100L/in_length));
2835 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2837 return (s->last_lit == s->lit_bufsize-1);
2838 /* We avoid equality with lit_bufsize because of wraparound at 64K
2839 * on 16 bit machines and because stored blocks are restricted to
2844 /* ===========================================================================
2845 * Send the block data compressed using the given Huffman trees
2847 local void compress_block(s, ltree, dtree)
2849 ct_data *ltree; /* literal tree */
2850 ct_data *dtree; /* distance tree */
2852 unsigned dist; /* distance of matched string */
2853 int lc; /* match length or unmatched char (if dist == 0) */
2854 unsigned lx = 0; /* running index in l_buf */
2855 unsigned code; /* the code to send */
2856 int extra; /* number of extra bits to send */
2858 if (s->last_lit != 0) do {
2859 dist = s->d_buf[lx];
2860 lc = s->l_buf[lx++];
2862 send_code(s, lc, ltree); /* send a literal byte */
2863 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2865 /* Here, lc is the match length - MIN_MATCH */
2866 code = length_code[lc];
2867 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2868 extra = extra_lbits[code];
2870 lc -= base_length[code];
2871 send_bits(s, lc, extra); /* send the extra length bits */
2873 dist--; /* dist is now the match distance - 1 */
2874 code = d_code(dist);
2875 Assert (code < D_CODES, "bad d_code");
2877 send_code(s, code, dtree); /* send the distance code */
2878 extra = extra_dbits[code];
2880 dist -= base_dist[code];
2881 send_bits(s, dist, extra); /* send the extra distance bits */
2883 } /* literal or match pair ? */
2885 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2886 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2888 } while (lx < s->last_lit);
2890 send_code(s, END_BLOCK, ltree);
2891 s->last_eob_len = ltree[END_BLOCK].Len;
2894 /* ===========================================================================
2895 * Set the data type to ASCII or BINARY, using a crude approximation:
2896 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2897 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2898 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2900 local void set_data_type(s)
2904 unsigned ascii_freq = 0;
2905 unsigned bin_freq = 0;
2906 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2907 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2908 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2909 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
2912 /* ===========================================================================
2913 * Reverse the first len bits of a code, using straightforward code (a faster
2914 * method would use a table)
2915 * IN assertion: 1 <= len <= 15
2917 local unsigned bi_reverse(code, len)
2918 unsigned code; /* the value to invert */
2919 int len; /* its bit length */
2921 register unsigned res = 0;
2924 code >>= 1, res <<= 1;
2925 } while (--len > 0);
2929 /* ===========================================================================
2930 * Flush the bit buffer, keeping at most 7 bits in it.
2932 local void bi_flush(s)
2935 if (s->bi_valid == 16) {
2936 put_short(s, s->bi_buf);
2939 } else if (s->bi_valid >= 8) {
2940 put_byte(s, (Byte)s->bi_buf);
2946 /* ===========================================================================
2947 * Flush the bit buffer and align the output on a byte boundary
2949 local void bi_windup(s)
2952 if (s->bi_valid > 8) {
2953 put_short(s, s->bi_buf);
2954 } else if (s->bi_valid > 0) {
2955 put_byte(s, (Byte)s->bi_buf);
2960 s->bits_sent = (s->bits_sent+7) & ~7;
2964 /* ===========================================================================
2965 * Copy a stored block, storing first the length and its
2966 * one's complement if requested.
2968 local void copy_block(s, buf, len, header)
2970 charf *buf; /* the input data */
2971 unsigned len; /* its length */
2972 int header; /* true if block header must be written */
2974 bi_windup(s); /* align on byte boundary */
2975 s->last_eob_len = 8; /* enough lookahead for inflate */
2978 put_short(s, (ush)len);
2979 put_short(s, (ush)~len);
2981 s->bits_sent += 2*16;
2985 s->bits_sent += (ulg)len<<3;
2987 /* bundle up the put_byte(s, *buf++) calls */
2988 zmemcpy(&s->pending_buf[s->pending], buf, len);
2994 /* inflate.c -- zlib interface to inflate modules
2995 * Copyright (C) 1995-1996 Mark Adler
2996 * For conditions of distribution and use, see copyright notice in zlib.h
2999 /* #include "zutil.h" */
3001 /* +++ infblock.h */
3002 /* infblock.h -- header to use infblock.c
3003 * Copyright (C) 1995-1996 Mark Adler
3004 * For conditions of distribution and use, see copyright notice in zlib.h
3007 /* WARNING: this file should *not* be used by applications. It is
3008 part of the implementation of the compression library and is
3009 subject to change. Applications should only use zlib.h.
3012 struct inflate_blocks_state;
3013 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3015 extern inflate_blocks_statef * inflate_blocks_new OF((
3017 check_func c, /* check function */
3018 uInt w)); /* window size */
3020 extern int inflate_blocks OF((
3021 inflate_blocks_statef *,
3023 int)); /* initial return code */
3025 extern void inflate_blocks_reset OF((
3026 inflate_blocks_statef *,
3028 uLongf *)); /* check value on output */
3030 extern int inflate_blocks_free OF((
3031 inflate_blocks_statef *,
3033 uLongf *)); /* check value on output */
3035 extern void inflate_set_dictionary OF((
3036 inflate_blocks_statef *s,
3037 const Bytef *d, /* dictionary */
3038 uInt n)); /* dictionary length */
3040 extern int inflate_addhistory OF((
3041 inflate_blocks_statef *,
3044 extern int inflate_packet_flush OF((
3045 inflate_blocks_statef *));
3046 /* --- infblock.h */
3048 #ifndef NO_DUMMY_DECL
3049 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3052 /* inflate private state */
3053 struct internal_state {
3057 METHOD, /* waiting for method byte */
3058 FLAG, /* waiting for flag byte */
3059 DICT4, /* four dictionary check bytes to go */
3060 DICT3, /* three dictionary check bytes to go */
3061 DICT2, /* two dictionary check bytes to go */
3062 DICT1, /* one dictionary check byte to go */
3063 DICT0, /* waiting for inflateSetDictionary */
3064 BLOCKS, /* decompressing blocks */
3065 CHECK4, /* four check bytes to go */
3066 CHECK3, /* three check bytes to go */
3067 CHECK2, /* two check bytes to go */
3068 CHECK1, /* one check byte to go */
3069 DONE, /* finished check, done */
3070 BAD} /* got an error--stay here */
3071 mode; /* current inflate mode */
3073 /* mode dependent information */
3075 uInt method; /* if FLAGS, method byte */
3077 uLong was; /* computed check value */
3078 uLong need; /* stream check value */
3079 } check; /* if CHECK, check values to compare */
3080 uInt marker; /* if BAD, inflateSync's marker bytes count */
3081 } sub; /* submode */
3083 /* mode independent information */
3084 int nowrap; /* flag for no wrapper */
3085 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3086 inflate_blocks_statef
3087 *blocks; /* current inflate_blocks state */
3097 if (z == Z_NULL || z->state == Z_NULL)
3098 return Z_STREAM_ERROR;
3099 z->total_in = z->total_out = 0;
3101 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3102 inflate_blocks_reset(z->state->blocks, z, &c);
3103 Trace((stderr, "inflate: reset\n"));
3113 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3114 return Z_STREAM_ERROR;
3115 if (z->state->blocks != Z_NULL)
3116 inflate_blocks_free(z->state->blocks, z, &c);
3119 Trace((stderr, "inflate: end\n"));
3124 int inflateInit2_(z, w, version, stream_size)
3127 const char *version;
3130 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3131 stream_size != sizeof(z_stream))
3132 return Z_VERSION_ERROR;
3134 /* initialize state */
3136 return Z_STREAM_ERROR;
3139 if (z->zalloc == Z_NULL)
3141 z->zalloc = zcalloc;
3142 z->opaque = (voidpf)0;
3144 if (z->zfree == Z_NULL) z->zfree = zcfree;
3146 if ((z->state = (struct internal_state FAR *)
3147 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3149 z->state->blocks = Z_NULL;
3151 /* handle undocumented nowrap option (no zlib header or check) */
3152 z->state->nowrap = 0;
3156 z->state->nowrap = 1;
3159 /* set window size */
3160 if (w < 8 || w > 15)
3163 return Z_STREAM_ERROR;
3165 z->state->wbits = (uInt)w;
3167 /* create inflate_blocks state */
3168 if ((z->state->blocks =
3169 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3175 Trace((stderr, "inflate: allocated\n"));
3183 int inflateInit_(z, version, stream_size)
3185 const char *version;
3188 return inflateInit2_(z, DEF_WBITS, version, stream_size);
3192 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3193 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3202 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0)
3203 return Z_STREAM_ERROR;
3205 while (1) switch (z->state->mode)
3209 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3211 z->state->mode = BAD;
3212 z->msg = (char*)"unknown compression method";
3213 z->state->sub.marker = 5; /* can't try inflateSync */
3216 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3218 z->state->mode = BAD;
3219 z->msg = (char*)"invalid window size";
3220 z->state->sub.marker = 5; /* can't try inflateSync */
3223 z->state->mode = FLAG;
3227 if (((z->state->sub.method << 8) + b) % 31)
3229 z->state->mode = BAD;
3230 z->msg = (char*)"incorrect header check";
3231 z->state->sub.marker = 5; /* can't try inflateSync */
3234 Trace((stderr, "inflate: zlib header ok\n"));
3235 if (!(b & PRESET_DICT))
3237 z->state->mode = BLOCKS;
3240 z->state->mode = DICT4;
3243 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3244 z->state->mode = DICT3;
3247 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3248 z->state->mode = DICT2;
3251 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3252 z->state->mode = DICT1;
3255 z->state->sub.check.need += (uLong)NEXTBYTE;
3256 z->adler = z->state->sub.check.need;
3257 z->state->mode = DICT0;
3260 z->state->mode = BAD;
3261 z->msg = (char*)"need dictionary";
3262 z->state->sub.marker = 0; /* can try inflateSync */
3263 return Z_STREAM_ERROR;
3265 r = inflate_blocks(z->state->blocks, z, r);
3266 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3267 r = inflate_packet_flush(z->state->blocks);
3268 if (r == Z_DATA_ERROR)
3270 z->state->mode = BAD;
3271 z->state->sub.marker = 0; /* can try inflateSync */
3274 if (r != Z_STREAM_END)
3277 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3278 if (z->state->nowrap)
3280 z->state->mode = DONE;
3283 z->state->mode = CHECK4;
3286 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3287 z->state->mode = CHECK3;
3290 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3291 z->state->mode = CHECK2;
3294 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3295 z->state->mode = CHECK1;
3298 z->state->sub.check.need += (uLong)NEXTBYTE;
3300 if (z->state->sub.check.was != z->state->sub.check.need)
3302 z->state->mode = BAD;
3303 z->msg = (char*)"incorrect data check";
3304 z->state->sub.marker = 5; /* can't try inflateSync */
3307 Trace((stderr, "inflate: zlib check ok\n"));
3308 z->state->mode = DONE;
3310 return Z_STREAM_END;
3312 return Z_DATA_ERROR;
3314 return Z_STREAM_ERROR;
3318 if (f != Z_PACKET_FLUSH)
3320 z->state->mode = BAD;
3321 z->msg = (char *)"need more for packet flush";
3322 z->state->sub.marker = 0; /* can try inflateSync */
3323 return Z_DATA_ERROR;
3327 int inflateSetDictionary(z, dictionary, dictLength)
3329 const Bytef *dictionary;
3332 uInt length = dictLength;
3334 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3335 return Z_STREAM_ERROR;
3337 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3340 if (length >= ((uInt)1<<z->state->wbits))
3342 length = (1<<z->state->wbits)-1;
3343 dictionary += dictLength - length;
3345 inflate_set_dictionary(z->state->blocks, dictionary, length);
3346 z->state->mode = BLOCKS;
3351 * This subroutine adds the data at next_in/avail_in to the output history
3352 * without performing any output. The output buffer must be "caught up";
3353 * i.e. no pending output (hence s->read equals s->write), and the state must
3354 * be BLOCKS (i.e. we should be willing to see the start of a series of
3355 * BLOCKS). On exit, the output will also be caught up, and the checksum
3356 * will have been updated if need be.
3359 int inflateIncomp(z)
3362 if (z->state->mode != BLOCKS)
3363 return Z_DATA_ERROR;
3364 return inflate_addhistory(z->state->blocks, z);
3371 uInt n; /* number of bytes to look at */
3372 Bytef *p; /* pointer to bytes */
3373 uInt m; /* number of marker bytes found in a row */
3374 uLong r, w; /* temporaries to save total_in and total_out */
3377 if (z == Z_NULL || z->state == Z_NULL)
3378 return Z_STREAM_ERROR;
3379 if (z->state->mode != BAD)
3381 z->state->mode = BAD;
3382 z->state->sub.marker = 0;
3384 if ((n = z->avail_in) == 0)
3387 m = z->state->sub.marker;
3392 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3402 z->total_in += p - z->next_in;
3405 z->state->sub.marker = m;
3407 /* return no joy or set up to restart on a new block */
3409 return Z_DATA_ERROR;
3410 r = z->total_in; w = z->total_out;
3412 z->total_in = r; z->total_out = w;
3413 z->state->mode = BLOCKS;
3421 /* +++ infblock.c */
3422 /* infblock.c -- interpret and process block types to last block
3423 * Copyright (C) 1995-1996 Mark Adler
3424 * For conditions of distribution and use, see copyright notice in zlib.h
3427 /* #include "zutil.h" */
3428 /* #include "infblock.h" */
3430 /* +++ inftrees.h */
3431 /* inftrees.h -- header to use inftrees.c
3432 * Copyright (C) 1995-1996 Mark Adler
3433 * For conditions of distribution and use, see copyright notice in zlib.h
3436 /* WARNING: this file should *not* be used by applications. It is
3437 part of the implementation of the compression library and is
3438 subject to change. Applications should only use zlib.h.
3441 /* Huffman code lookup table entry--this entry is four bytes for machines
3442 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3444 typedef struct inflate_huft_s FAR inflate_huft;
3446 struct inflate_huft_s {
3449 Byte Exop; /* number of extra bits or operation */
3450 Byte Bits; /* number of bits in this code or subcode */
3452 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
3453 } word; /* 16-bit, 8 bytes for 32-bit machines) */
3455 uInt Base; /* literal, length base, or distance base */
3456 inflate_huft *Next; /* pointer to next level of table */
3461 extern uInt inflate_hufts;
3464 extern int inflate_trees_bits OF((
3465 uIntf *, /* 19 code lengths */
3466 uIntf *, /* bits tree desired/actual depth */
3467 inflate_huft * FAR *, /* bits tree result */
3468 z_streamp )); /* for zalloc, zfree functions */
3470 extern int inflate_trees_dynamic OF((
3471 uInt, /* number of literal/length codes */
3472 uInt, /* number of distance codes */
3473 uIntf *, /* that many (total) code lengths */
3474 uIntf *, /* literal desired/actual bit depth */
3475 uIntf *, /* distance desired/actual bit depth */
3476 inflate_huft * FAR *, /* literal/length tree result */
3477 inflate_huft * FAR *, /* distance tree result */
3478 z_streamp )); /* for zalloc, zfree functions */
3480 extern int inflate_trees_fixed OF((
3481 uIntf *, /* literal desired/actual bit depth */
3482 uIntf *, /* distance desired/actual bit depth */
3483 inflate_huft * FAR *, /* literal/length tree result */
3484 inflate_huft * FAR *)); /* distance tree result */
3486 extern int inflate_trees_free OF((
3487 inflate_huft *, /* tables to free */
3488 z_streamp )); /* for zfree function */
3490 /* --- inftrees.h */
3492 /* +++ infcodes.h */
3493 /* infcodes.h -- header to use infcodes.c
3494 * Copyright (C) 1995-1996 Mark Adler
3495 * For conditions of distribution and use, see copyright notice in zlib.h
3498 /* WARNING: this file should *not* be used by applications. It is
3499 part of the implementation of the compression library and is
3500 subject to change. Applications should only use zlib.h.
3503 struct inflate_codes_state;
3504 typedef struct inflate_codes_state FAR inflate_codes_statef;
3506 extern inflate_codes_statef *inflate_codes_new OF((
3508 inflate_huft *, inflate_huft *,
3511 extern int inflate_codes OF((
3512 inflate_blocks_statef *,
3516 extern void inflate_codes_free OF((
3517 inflate_codes_statef *,
3520 /* --- infcodes.h */
3523 /* infutil.h -- types and macros common to blocks and codes
3524 * Copyright (C) 1995-1996 Mark Adler
3525 * For conditions of distribution and use, see copyright notice in zlib.h
3528 /* WARNING: this file should *not* be used by applications. It is
3529 part of the implementation of the compression library and is
3530 subject to change. Applications should only use zlib.h.
3537 TYPE, /* get type bits (3, including end bit) */
3538 LENS, /* get lengths for stored */
3539 STORED, /* processing stored block */
3540 TABLE, /* get table lengths */
3541 BTREE, /* get bit lengths tree for a dynamic block */
3542 DTREE, /* get length, distance trees for a dynamic block */
3543 CODES, /* processing fixed or dynamic block */
3544 DRY, /* output remaining window bytes */
3545 DONEB, /* finished last block, done */
3546 BADB} /* got a data error--stuck here */
3549 /* inflate blocks semi-private state */
3550 struct inflate_blocks_state {
3553 inflate_block_mode mode; /* current inflate_block mode */
3555 /* mode dependent information */
3557 uInt left; /* if STORED, bytes left to copy */
3559 uInt table; /* table lengths (14 bits) */
3560 uInt index; /* index into blens (or border) */
3561 uIntf *blens; /* bit lengths of codes */
3562 uInt bb; /* bit length tree depth */
3563 inflate_huft *tb; /* bit length decoding tree */
3564 } trees; /* if DTREE, decoding info for trees */
3567 inflate_huft *td; /* trees to free */
3568 inflate_codes_statef
3570 } decode; /* if CODES, current state */
3571 } sub; /* submode */
3572 uInt last; /* true if this block is the last block */
3574 /* mode independent information */
3575 uInt bitk; /* bits in bit buffer */
3576 uLong bitb; /* bit buffer */
3577 Bytef *window; /* sliding window */
3578 Bytef *end; /* one byte after sliding window */
3579 Bytef *read; /* window read pointer */
3580 Bytef *write; /* window write pointer */
3581 check_func checkfn; /* check function */
3582 uLong check; /* check on output */
3587 /* defines for inflate input/output */
3588 /* update pointers and return */
3589 #define UPDBITS {s->bitb=b;s->bitk=k;}
3590 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3591 #define UPDOUT {s->write=q;}
3592 #define UPDATE {UPDBITS UPDIN UPDOUT}
3593 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3594 /* get bytes and bits */
3595 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3596 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3597 #define NEXTBYTE (n--,*p++)
3598 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3599 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3601 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3602 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3603 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3604 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3605 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;}
3606 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3607 /* load local pointers */
3608 #define LOAD {LOADIN LOADOUT}
3610 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3611 extern uInt inflate_mask[17];
3613 /* copy as much as possible from the sliding window to the output area */
3614 extern int inflate_flush OF((
3615 inflate_blocks_statef *,
3619 #ifndef NO_DUMMY_DECL
3620 struct internal_state {int dummy;}; /* for buggy compilers */
3626 #ifndef NO_DUMMY_DECL
3627 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3630 /* Table for deflate from PKZIP's appnote.txt. */
3631 local const uInt border[] = { /* Order of the bit length code lengths */
3632 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3635 Notes beyond the 1.93a appnote.txt:
3637 1. Distance pointers never point before the beginning of the output
3639 2. Distance pointers can point back across blocks, up to 32k away.
3640 3. There is an implied maximum of 7 bits for the bit length table and
3641 15 bits for the actual data.
3642 4. If only one code exists, then it is encoded using one bit. (Zero
3643 would be more efficient, but perhaps a little confusing.) If two
3644 codes exist, they are coded using one bit each (0 and 1).
3645 5. There is no way of sending zero distance codes--a dummy must be
3646 sent if there are none. (History: a pre 2.0 version of PKZIP would
3647 store blocks with no distance codes, but this was discovered to be
3648 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3649 zero distance codes, which is sent as one code of zero bits in
3651 6. There are up to 286 literal/length codes. Code 256 represents the
3652 end-of-block. Note however that the static length tree defines
3653 288 codes just to fill out the Huffman codes. Codes 286 and 287
3654 cannot be used though, since there is no length base or extra bits
3655 defined for them. Similarily, there are up to 30 distance codes.
3656 However, static trees define 32 codes (all 5 bits) to fill out the
3657 Huffman codes, but the last two had better not show up in the data.
3658 7. Unzip can check dynamic Huffman blocks for complete code sets.
3659 The exception is that a single code would not be complete (see #4).
3660 8. The five bits following the block type is really the number of
3661 literal codes sent minus 257.
3662 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3663 (1+6+6). Therefore, to output three times the length, you output
3664 three codes (1+1+1), whereas to output four times the same length,
3665 you only need two codes (1+3). Hmm.
3666 10. In the tree reconstruction algorithm, Code = Code + Increment
3667 only if BitLength(i) is not zero. (Pretty obvious.)
3668 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3669 12. Note: length code 284 can represent 227-258, but length code 285
3670 really is 258. The last length deserves its own, short code
3671 since it gets used a lot in very redundant files. The length
3672 258 is special since 258 - 3 (the min match length) is 255.
3673 13. The literal/length and distance code bit lengths are read as a
3674 single stream of lengths. It is possible (and advantageous) for
3675 a repeat code (16, 17, or 18) to go across the boundary between
3676 the two sets of lengths.
3680 void inflate_blocks_reset(s, z, c)
3681 inflate_blocks_statef *s;
3685 if (s->checkfn != Z_NULL)
3687 if (s->mode == BTREE || s->mode == DTREE)
3688 ZFREE(z, s->sub.trees.blens);
3689 if (s->mode == CODES)
3691 inflate_codes_free(s->sub.decode.codes, z);
3692 inflate_trees_free(s->sub.decode.td, z);
3693 inflate_trees_free(s->sub.decode.tl, z);
3698 s->read = s->write = s->window;
3699 if (s->checkfn != Z_NULL)
3700 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
3701 Trace((stderr, "inflate: blocks reset\n"));
3705 inflate_blocks_statef *inflate_blocks_new(z, c, w)
3710 inflate_blocks_statef *s;
3712 if ((s = (inflate_blocks_statef *)ZALLOC
3713 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3715 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3720 s->end = s->window + w;
3723 Trace((stderr, "inflate: blocks allocated\n"));
3724 inflate_blocks_reset(s, z, &s->check);
3730 extern uInt inflate_hufts;
3732 int inflate_blocks(s, z, r)
3733 inflate_blocks_statef *s;
3737 uInt t; /* temporary storage */
3738 uLong b; /* bit buffer */
3739 uInt k; /* bits in bit buffer */
3740 Bytef *p; /* input data pointer */
3741 uInt n; /* bytes available there */
3742 Bytef *q; /* output window write pointer */
3743 uInt m; /* bytes to end of window or read pointer */
3745 /* copy input/output information to locals (UPDATE macro restores) */
3748 /* process input based on current state */
3749 while (1) switch (s->mode)
3757 case 0: /* stored */
3758 Trace((stderr, "inflate: stored block%s\n",
3759 s->last ? " (last)" : ""));
3761 t = k & 7; /* go to byte boundary */
3763 s->mode = LENS; /* get length of stored block */
3766 Trace((stderr, "inflate: fixed codes block%s\n",
3767 s->last ? " (last)" : ""));
3770 inflate_huft *tl, *td;
3772 inflate_trees_fixed(&bl, &bd, &tl, &td);
3773 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3774 if (s->sub.decode.codes == Z_NULL)
3779 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3780 s->sub.decode.td = Z_NULL;
3785 case 2: /* dynamic */
3786 Trace((stderr, "inflate: dynamic codes block%s\n",
3787 s->last ? " (last)" : ""));
3791 case 3: /* illegal */
3794 z->msg = (char*)"invalid block type";
3801 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
3804 z->msg = (char*)"invalid stored block lengths";
3808 s->sub.left = (uInt)b & 0xffff;
3809 b = k = 0; /* dump bits */
3810 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3811 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
3823 if ((s->sub.left -= t) != 0)
3825 Tracev((stderr, "inflate: stored end, %lu total out\n",
3826 z->total_out + (q >= s->read ? q - s->read :
3827 (s->end - s->read) + (q - s->window))));
3828 s->mode = s->last ? DRY : TYPE;
3832 s->sub.trees.table = t = (uInt)b & 0x3fff;
3833 #ifndef PKZIP_BUG_WORKAROUND
3834 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3837 z->msg = (char*)"too many length or distance symbols";
3842 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3845 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3851 s->sub.trees.index = 0;
3852 Tracev((stderr, "inflate: table sizes ok\n"));
3855 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3858 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3861 while (s->sub.trees.index < 19)
3862 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3863 s->sub.trees.bb = 7;
3864 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3865 &s->sub.trees.tb, z);
3869 if (r == Z_DATA_ERROR) {
3870 ZFREE(z, s->sub.trees.blens);
3875 s->sub.trees.index = 0;
3876 Tracev((stderr, "inflate: bits tree ok\n"));
3879 while (t = s->sub.trees.table,
3880 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3885 t = s->sub.trees.bb;
3887 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3888 t = h->word.what.Bits;
3893 s->sub.trees.blens[s->sub.trees.index++] = c;
3895 else /* c == 16..18 */
3897 i = c == 18 ? 7 : c - 14;
3898 j = c == 18 ? 11 : 3;
3901 j += (uInt)b & inflate_mask[i];
3903 i = s->sub.trees.index;
3904 t = s->sub.trees.table;
3905 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3908 inflate_trees_free(s->sub.trees.tb, z);
3909 ZFREE(z, s->sub.trees.blens);
3911 z->msg = (char*)"invalid bit length repeat";
3915 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3917 s->sub.trees.blens[i++] = c;
3919 s->sub.trees.index = i;
3922 inflate_trees_free(s->sub.trees.tb, z);
3923 s->sub.trees.tb = Z_NULL;
3926 inflate_huft *tl, *td;
3927 inflate_codes_statef *c;
3929 bl = 9; /* must be <= 9 for lookahead assumptions */
3930 bd = 6; /* must be <= 9 for lookahead assumptions */
3931 t = s->sub.trees.table;
3935 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3936 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3939 if (t == (uInt)Z_DATA_ERROR) {
3940 ZFREE(z, s->sub.trees.blens);
3946 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n",
3947 inflate_hufts, sizeof(inflate_huft)));
3948 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3950 inflate_trees_free(td, z);
3951 inflate_trees_free(tl, z);
3956 * this ZFREE must occur *BEFORE* we mess with sub.decode, because
3957 * sub.trees is union'd with sub.decode.
3959 ZFREE(z, s->sub.trees.blens);
3960 s->sub.decode.codes = c;
3961 s->sub.decode.tl = tl;
3962 s->sub.decode.td = td;
3967 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3968 return inflate_flush(s, z, r);
3970 inflate_codes_free(s->sub.decode.codes, z);
3971 inflate_trees_free(s->sub.decode.td, z);
3972 inflate_trees_free(s->sub.decode.tl, z);
3974 Tracev((stderr, "inflate: codes end, %lu total out\n",
3975 z->total_out + (q >= s->read ? q - s->read :
3976 (s->end - s->read) + (q - s->window))));
3982 if (k > 7) /* return unused byte, if any */
3984 Assert(k < 16, "inflate_codes grabbed too many bytes")
3987 p--; /* can always return one */
3992 if (s->read != s->write)
4008 int inflate_blocks_free(s, z, c)
4009 inflate_blocks_statef *s;
4013 inflate_blocks_reset(s, z, c);
4014 ZFREE(z, s->window);
4016 Trace((stderr, "inflate: blocks freed\n"));
4021 void inflate_set_dictionary(s, d, n)
4022 inflate_blocks_statef *s;
4026 zmemcpy((charf *)s->window, d, n);
4027 s->read = s->write = s->window + n;
4031 * This subroutine adds the data at next_in/avail_in to the output history
4032 * without performing any output. The output buffer must be "caught up";
4033 * i.e. no pending output (hence s->read equals s->write), and the state must
4034 * be BLOCKS (i.e. we should be willing to see the start of a series of
4035 * BLOCKS). On exit, the output will also be caught up, and the checksum
4036 * will have been updated if need be.
4038 int inflate_addhistory(s, z)
4039 inflate_blocks_statef *s;
4042 uLong b; /* bit buffer */ /* NOT USED HERE */
4043 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
4044 uInt t; /* temporary storage */
4045 Bytef *p; /* input data pointer */
4046 uInt n; /* bytes available there */
4047 Bytef *q; /* output window write pointer */
4048 uInt m; /* bytes to end of window or read pointer */
4050 if (s->read != s->write)
4051 return Z_STREAM_ERROR;
4052 if (s->mode != TYPE)
4053 return Z_DATA_ERROR;
4055 /* we're ready to rock */
4057 /* while there is input ready, copy to output buffer, moving
4058 * pointers as needed.
4061 t = n; /* how many to do */
4062 /* is there room until end of buffer? */
4064 /* update check information */
4065 if (s->checkfn != Z_NULL)
4066 s->check = (*s->checkfn)(s->check, q, t);
4072 s->read = q; /* drag read pointer forward */
4073 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */
4075 s->read = q = s->window;
4085 * At the end of a Deflate-compressed PPP packet, we expect to have seen
4086 * a `stored' block type value but not the (zero) length bytes.
4088 int inflate_packet_flush(s)
4089 inflate_blocks_statef *s;
4091 if (s->mode != LENS)
4092 return Z_DATA_ERROR;
4096 /* --- infblock.c */
4098 /* +++ inftrees.c */
4099 /* inftrees.c -- generate Huffman trees for efficient decoding
4100 * Copyright (C) 1995-1996 Mark Adler
4101 * For conditions of distribution and use, see copyright notice in zlib.h
4104 /* #include "zutil.h" */
4105 /* #include "inftrees.h" */
4107 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler ";
4109 If you use the zlib library in a product, an acknowledgment is welcome
4110 in the documentation of your product. If for some reason you cannot
4111 include such an acknowledgment, I would appreciate that you keep this
4112 copyright string in the executable of your product.
4115 #ifndef NO_DUMMY_DECL
4116 struct internal_state {int dummy;}; /* for buggy compilers */
4119 /* simplify the use of the inflate_huft type with some defines */
4120 #define base more.Base
4121 #define next more.Next
4122 #define exop word.what.Exop
4123 #define bits word.what.Bits
4126 local int huft_build OF((
4127 uIntf *, /* code lengths in bits */
4128 uInt, /* number of codes */
4129 uInt, /* number of "simple" codes */
4130 const uIntf *, /* list of base values for non-simple codes */
4131 const uIntf *, /* list of extra bits for non-simple codes */
4132 inflate_huft * FAR*,/* result: starting table */
4133 uIntf *, /* maximum lookup bits (returns actual) */
4134 z_streamp )); /* for zalloc function */
4136 local voidpf falloc OF((
4137 voidpf, /* opaque pointer (not used) */
4138 uInt, /* number of items */
4139 uInt)); /* size of item */
4141 /* Tables for deflate from PKZIP's appnote.txt. */
4142 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4143 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4144 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4145 /* see note #13 above about 258 */
4146 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4147 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4148 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4149 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4150 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4151 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4152 8193, 12289, 16385, 24577};
4153 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4154 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4155 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4159 Huffman code decoding is performed using a multi-level table lookup.
4160 The fastest way to decode is to simply build a lookup table whose
4161 size is determined by the longest code. However, the time it takes
4162 to build this table can also be a factor if the data being decoded
4163 is not very long. The most common codes are necessarily the
4164 shortest codes, so those codes dominate the decoding time, and hence
4165 the speed. The idea is you can have a shorter table that decodes the
4166 shorter, more probable codes, and then point to subsidiary tables for
4167 the longer codes. The time it costs to decode the longer codes is
4168 then traded against the time it takes to make longer tables.
4170 This results of this trade are in the variables lbits and dbits
4171 below. lbits is the number of bits the first level table for literal/
4172 length codes can decode in one step, and dbits is the same thing for
4173 the distance codes. Subsequent tables are also less than or equal to
4174 those sizes. These values may be adjusted either when all of the
4175 codes are shorter than that, in which case the longest code length in
4176 bits is used, or when the shortest code is *longer* than the requested
4177 table size, in which case the length of the shortest code in bits is
4180 There are two different values for the two tables, since they code a
4181 different number of possibilities each. The literal/length table
4182 codes 286 possible values, or in a flat code, a little over eight
4183 bits. The distance table codes 30 possible values, or a little less
4184 than five bits, flat. The optimum values for speed end up being
4185 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4186 The optimum values may differ though from machine to machine, and
4187 possibly even between compilers. Your mileage may vary.
4191 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4192 #define BMAX 15 /* maximum bit length of any code */
4193 #define N_MAX 288 /* maximum number of codes in any set */
4199 local int huft_build(b, n, s, d, e, t, m, zs)
4200 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
4201 uInt n; /* number of codes (assumed <= N_MAX) */
4202 uInt s; /* number of simple-valued codes (0..s-1) */
4203 const uIntf *d; /* list of base values for non-simple codes */
4204 const uIntf *e; /* list of extra bits for non-simple codes */
4205 inflate_huft * FAR *t; /* result: starting table */
4206 uIntf *m; /* maximum lookup bits, returns actual */
4207 z_streamp zs; /* for zalloc function */
4208 /* Given a list of code lengths and a maximum table size, make a set of
4209 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
4210 if the given code set is incomplete (the tables are still built in this
4211 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of
4212 lengths), or Z_MEM_ERROR if not enough memory. */
4215 uInt a; /* counter for codes of length k */
4216 uInt c[BMAX+1]; /* bit length count table */
4217 uInt f; /* i repeats in table every f entries */
4218 int g; /* maximum code length */
4219 int h; /* table level */
4220 register uInt i; /* counter, current code */
4221 register uInt j; /* counter */
4222 register int k; /* number of bits in current code */
4223 int l; /* bits per table (returned in m) */
4224 register uIntf *p; /* pointer into c[], b[], or v[] */
4225 inflate_huft *q; /* points to current table */
4226 struct inflate_huft_s r; /* table entry for structure assignment */
4227 inflate_huft *u[BMAX]; /* table stack */
4228 uInt v[N_MAX]; /* values in order of bit length */
4229 register int w; /* bits before this table == (l * h) */
4230 uInt x[BMAX+1]; /* bit offsets, then code stack */
4231 uIntf *xp; /* pointer into x */
4232 int y; /* number of dummy codes added */
4233 uInt z; /* number of entries in current table */
4236 /* Generate counts for each bit length */
4238 #define C0 *p++ = 0;
4239 #define C2 C0 C0 C0 C0
4240 #define C4 C2 C2 C2 C2
4241 C4 /* clear c[]--assume BMAX+1 is 16 */
4244 c[*p++]++; /* assume all entries <= BMAX */
4246 if (c[0] == n) /* null input--all zero length codes */
4248 *t = (inflate_huft *)Z_NULL;
4254 /* Find minimum and maximum length, bound *m by those */
4256 for (j = 1; j <= BMAX; j++)
4259 k = j; /* minimum code length */
4262 for (i = BMAX; i; i--)
4265 g = i; /* maximum code length */
4271 /* Adjust last length count to fill out codes, if needed */
4272 for (y = 1 << j; j < i; j++, y <<= 1)
4273 if ((y -= c[j]) < 0)
4274 return Z_DATA_ERROR;
4275 if ((y -= c[i]) < 0)
4276 return Z_DATA_ERROR;
4280 /* Generate starting offsets into the value table for each length */
4282 p = c + 1; xp = x + 2;
4283 while (--i) { /* note that i == g from above */
4284 *xp++ = (j += *p++);
4288 /* Make a table of values in order of bit lengths */
4291 if ((j = *p++) != 0)
4294 n = x[g]; /* set n to length of v */
4297 /* Generate the Huffman codes and for each, make the table entries */
4298 x[0] = i = 0; /* first Huffman code is zero */
4299 p = v; /* grab values in bit order */
4300 h = -1; /* no tables yet--level -1 */
4301 w = -l; /* bits decoded == (l * h) */
4302 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
4303 q = (inflate_huft *)Z_NULL; /* ditto */
4306 /* go through the bit lengths (k already is bits in shortest code) */
4312 /* here i is the Huffman code of length k bits for value *p */
4313 /* make tables up to required level */
4317 w += l; /* previous table always l bits */
4319 /* compute minimum size table less than or equal to l bits */
4321 z = z > (uInt)l ? l : z; /* table size upper limit */
4322 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
4323 { /* too few codes for k-w bit table */
4324 f -= a + 1; /* deduct codes from patterns left */
4327 while (++j < z) /* try smaller tables up to z bits */
4329 if ((f <<= 1) <= *++xp)
4330 break; /* enough codes to use up j bits */
4331 f -= *xp; /* else deduct codes from patterns */
4334 z = 1 << j; /* table entries for j-bit table */
4336 /* allocate and link in new table */
4337 if ((q = (inflate_huft *)ZALLOC
4338 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
4341 inflate_trees_free(u[0], zs);
4342 return Z_MEM_ERROR; /* not enough memory */
4345 inflate_hufts += z + 1;
4347 *t = q + 1; /* link to list for huft_free() */
4348 *(t = &(q->next)) = Z_NULL;
4349 u[h] = ++q; /* table starts after link */
4351 /* connect to last table, if there is one */
4354 x[h] = i; /* save pattern for backing up */
4355 r.bits = (Byte)l; /* bits to dump before this table */
4356 r.exop = (Byte)j; /* bits in this table */
4357 r.next = q; /* pointer to this table */
4358 j = i >> (w - l); /* (get around Turbo C bug) */
4359 u[h-1][j] = r; /* connect to last table */
4363 /* set up table entry in r */
4364 r.bits = (Byte)(k - w);
4366 r.exop = 128 + 64; /* out of values--invalid code */
4369 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
4370 r.base = *p++; /* simple code is just the value */
4374 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4375 r.base = d[*p++ - s];
4378 /* fill code-like entries with r */
4380 for (j = i >> w; j < z; j += f)
4383 /* backwards increment the k-bit code i */
4384 for (j = 1 << (k - 1); i & j; j >>= 1)
4388 /* backup over finished tables */
4389 while ((i & ((1 << w) - 1)) != x[h])
4391 h--; /* don't need to update q */
4398 /* Return Z_BUF_ERROR if we were given an incomplete table */
4399 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4403 int inflate_trees_bits(c, bb, tb, z)
4404 uIntf *c; /* 19 code lengths */
4405 uIntf *bb; /* bits tree desired/actual depth */
4406 inflate_huft * FAR *tb; /* bits tree result */
4407 z_streamp z; /* for zfree function */
4411 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
4412 if (r == Z_DATA_ERROR)
4413 z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4414 else if (r == Z_BUF_ERROR || *bb == 0)
4416 inflate_trees_free(*tb, z);
4417 z->msg = (char*)"incomplete dynamic bit lengths tree";
4424 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
4425 uInt nl; /* number of literal/length codes */
4426 uInt nd; /* number of distance codes */
4427 uIntf *c; /* that many (total) code lengths */
4428 uIntf *bl; /* literal desired/actual bit depth */
4429 uIntf *bd; /* distance desired/actual bit depth */
4430 inflate_huft * FAR *tl; /* literal/length tree result */
4431 inflate_huft * FAR *td; /* distance tree result */
4432 z_streamp z; /* for zfree function */
4436 /* build literal/length tree */
4437 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z);
4438 if (r != Z_OK || *bl == 0)
4440 if (r == Z_DATA_ERROR)
4441 z->msg = (char*)"oversubscribed literal/length tree";
4442 else if (r != Z_MEM_ERROR)
4444 inflate_trees_free(*tl, z);
4445 z->msg = (char*)"incomplete literal/length tree";
4451 /* build distance tree */
4452 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z);
4453 if (r != Z_OK || (*bd == 0 && nl > 257))
4455 if (r == Z_DATA_ERROR)
4456 z->msg = (char*)"oversubscribed distance tree";
4457 else if (r == Z_BUF_ERROR) {
4458 #ifdef PKZIP_BUG_WORKAROUND
4462 inflate_trees_free(*td, z);
4463 z->msg = (char*)"incomplete distance tree";
4466 else if (r != Z_MEM_ERROR)
4468 z->msg = (char*)"empty distance tree with lengths";
4471 inflate_trees_free(*tl, z);
4481 /* build fixed tables only once--keep them here */
4482 local int fixed_built = 0;
4483 #define FIXEDH 530 /* number of hufts used by fixed tables */
4484 local inflate_huft fixed_mem[FIXEDH];
4485 local uInt fixed_bl;
4486 local uInt fixed_bd;
4487 local inflate_huft *fixed_tl;
4488 local inflate_huft *fixed_td;
4491 local voidpf falloc(q, n, s)
4492 voidpf q; /* opaque pointer */
4493 uInt n; /* number of items */
4494 uInt s; /* size of item */
4496 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q,
4497 "inflate_trees falloc overflow");
4498 *(intf *)q -= n+s-s; /* s-s to avoid warning */
4499 return (voidpf)(fixed_mem + *(intf *)q);
4503 int inflate_trees_fixed(bl, bd, tl, td)
4504 uIntf *bl; /* literal desired/actual bit depth */
4505 uIntf *bd; /* distance desired/actual bit depth */
4506 inflate_huft * FAR *tl; /* literal/length tree result */
4507 inflate_huft * FAR *td; /* distance tree result */
4509 /* build fixed tables if not already (multiple overlapped executions ok) */
4512 int k; /* temporary variable */
4513 unsigned c[288]; /* length list for huft_build */
4514 z_stream z; /* for falloc function */
4515 int f = FIXEDH; /* number of hufts left in fixed_mem */
4517 /* set up fake z_stream for memory routines */
4520 z.opaque = (voidpf)&f;
4523 for (k = 0; k < 144; k++)
4525 for (; k < 256; k++)
4527 for (; k < 280; k++)
4529 for (; k < 288; k++)
4532 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4534 /* distance table */
4535 for (k = 0; k < 30; k++)
4538 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4541 Assert(f == 0, "invalid build of fixed tables");
4552 int inflate_trees_free(t, z)
4553 inflate_huft *t; /* table to free */
4554 z_streamp z; /* for zfree function */
4555 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4556 list of the tables it made, with the links in a dummy first entry of
4559 register inflate_huft *p, *q, *r;
4561 /* Reverse linked list */
4571 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4580 /* --- inftrees.c */
4582 /* +++ infcodes.c */
4583 /* infcodes.c -- process literals and length/distance pairs
4584 * Copyright (C) 1995-1996 Mark Adler
4585 * For conditions of distribution and use, see copyright notice in zlib.h
4588 /* #include "zutil.h" */
4589 /* #include "inftrees.h" */
4590 /* #include "infblock.h" */
4591 /* #include "infcodes.h" */
4592 /* #include "infutil.h" */
4595 /* inffast.h -- header to use inffast.c
4596 * Copyright (C) 1995-1996 Mark Adler
4597 * For conditions of distribution and use, see copyright notice in zlib.h
4600 /* WARNING: this file should *not* be used by applications. It is
4601 part of the implementation of the compression library and is
4602 subject to change. Applications should only use zlib.h.
4605 extern int inflate_fast OF((
4610 inflate_blocks_statef *,
4614 /* simplify the use of the inflate_huft type with some defines */
4615 #define base more.Base
4616 #define next more.Next
4617 #define exop word.what.Exop
4618 #define bits word.what.Bits
4620 /* inflate codes private state */
4621 struct inflate_codes_state {
4624 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4625 START, /* x: set up for LEN */
4626 LEN, /* i: get length/literal/eob next */
4627 LENEXT, /* i: getting length extra (have base) */
4628 DIST, /* i: get distance next */
4629 DISTEXT, /* i: getting distance extra */
4630 COPY, /* o: copying bytes in window, waiting for space */
4631 LIT, /* o: got literal, waiting for output space */
4632 WASH, /* o: got eob, possibly still output waiting */
4633 END, /* x: got eob and all data flushed */
4634 BADCODE} /* x: got error */
4635 mode; /* current inflate_codes mode */
4637 /* mode dependent information */
4641 inflate_huft *tree; /* pointer into tree */
4642 uInt need; /* bits needed */
4643 } code; /* if LEN or DIST, where in tree */
4644 uInt lit; /* if LIT, literal */
4646 uInt get; /* bits to get for extra */
4647 uInt dist; /* distance back to copy from */
4648 } copy; /* if EXT or COPY, where and how much */
4649 } sub; /* submode */
4651 /* mode independent information */
4652 Byte lbits; /* ltree bits decoded per branch */
4653 Byte dbits; /* dtree bits decoder per branch */
4654 inflate_huft *ltree; /* literal/length/eob tree */
4655 inflate_huft *dtree; /* distance tree */
4660 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4663 inflate_huft *td; /* need separate declaration for Borland C++ */
4666 inflate_codes_statef *c;
4668 if ((c = (inflate_codes_statef *)
4669 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4672 c->lbits = (Byte)bl;
4673 c->dbits = (Byte)bd;
4676 Tracev((stderr, "inflate: codes new\n"));
4682 int inflate_codes(s, z, r)
4683 inflate_blocks_statef *s;
4687 uInt j; /* temporary storage */
4688 inflate_huft *t; /* temporary pointer */
4689 uInt e; /* extra bits or operation */
4690 uLong b; /* bit buffer */
4691 uInt k; /* bits in bit buffer */
4692 Bytef *p; /* input data pointer */
4693 uInt n; /* bytes available there */
4694 Bytef *q; /* output window write pointer */
4695 uInt m; /* bytes to end of window or read pointer */
4696 Bytef *f; /* pointer to copy strings from */
4697 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4699 /* copy input/output information to locals (UPDATE macro restores) */
4702 /* process input and output based on current state */
4703 while (1) switch (c->mode)
4704 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4705 case START: /* x: set up for LEN */
4707 if (m >= 258 && n >= 10)
4710 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4714 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4719 c->sub.code.need = c->lbits;
4720 c->sub.code.tree = c->ltree;
4722 case LEN: /* i: get length/literal/eob next */
4723 j = c->sub.code.need;
4725 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4727 e = (uInt)(t->exop);
4728 if (e == 0) /* literal */
4730 c->sub.lit = t->base;
4731 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4732 "inflate: literal '%c'\n" :
4733 "inflate: literal 0x%02x\n", t->base));
4737 if (e & 16) /* length */
4739 c->sub.copy.get = e & 15;
4744 if ((e & 64) == 0) /* next table */
4746 c->sub.code.need = e;
4747 c->sub.code.tree = t->next;
4750 if (e & 32) /* end of block */
4752 Tracevv((stderr, "inflate: end of block\n"));
4756 c->mode = BADCODE; /* invalid code */
4757 z->msg = (char*)"invalid literal/length code";
4760 case LENEXT: /* i: getting length extra (have base) */
4761 j = c->sub.copy.get;
4763 c->len += (uInt)b & inflate_mask[j];
4765 c->sub.code.need = c->dbits;
4766 c->sub.code.tree = c->dtree;
4767 Tracevv((stderr, "inflate: length %u\n", c->len));
4769 case DIST: /* i: get distance next */
4770 j = c->sub.code.need;
4772 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4774 e = (uInt)(t->exop);
4775 if (e & 16) /* distance */
4777 c->sub.copy.get = e & 15;
4778 c->sub.copy.dist = t->base;
4782 if ((e & 64) == 0) /* next table */
4784 c->sub.code.need = e;
4785 c->sub.code.tree = t->next;
4788 c->mode = BADCODE; /* invalid code */
4789 z->msg = (char*)"invalid distance code";
4792 case DISTEXT: /* i: getting distance extra */
4793 j = c->sub.copy.get;
4795 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4797 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4799 case COPY: /* o: copying bytes in window, waiting for space */
4800 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4801 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4802 s->end - (c->sub.copy.dist - (q - s->window)) :
4803 q - c->sub.copy.dist;
4805 f = q - c->sub.copy.dist;
4806 if ((uInt)(q - s->window) < c->sub.copy.dist)
4807 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
4819 case LIT: /* o: got literal, waiting for output space */
4824 case WASH: /* o: got eob, possibly more output */
4826 if (s->read != s->write)
4832 case BADCODE: /* x: got error */
4842 void inflate_codes_free(c, z)
4843 inflate_codes_statef *c;
4847 Tracev((stderr, "inflate: codes free\n"));
4849 /* --- infcodes.c */
4852 /* inflate_util.c -- data and routines common to blocks and codes
4853 * Copyright (C) 1995-1996 Mark Adler
4854 * For conditions of distribution and use, see copyright notice in zlib.h
4857 /* #include "zutil.h" */
4858 /* #include "infblock.h" */
4859 /* #include "inftrees.h" */
4860 /* #include "infcodes.h" */
4861 /* #include "infutil.h" */
4863 #ifndef NO_DUMMY_DECL
4864 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4867 /* And'ing with mask[n] masks the lower n bits */
4868 uInt inflate_mask[17] = {
4870 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
4871 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
4875 /* copy as much as possible from the sliding window to the output area */
4876 int inflate_flush(s, z, r)
4877 inflate_blocks_statef *s;
4885 /* local copies of source and destination pointers */
4889 /* compute number of bytes to copy as far as end of window */
4890 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4891 if (n > z->avail_out) n = z->avail_out;
4892 if (n && r == Z_BUF_ERROR) r = Z_OK;
4894 /* update counters */
4898 /* update check information */
4899 if (s->checkfn != Z_NULL)
4900 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4902 /* copy as far as end of window */
4909 /* see if more to copy at beginning of window */
4914 if (s->write == s->end)
4915 s->write = s->window;
4917 /* compute bytes to copy */
4918 n = (uInt)(s->write - q);
4919 if (n > z->avail_out) n = z->avail_out;
4920 if (n && r == Z_BUF_ERROR) r = Z_OK;
4922 /* update counters */
4926 /* update check information */
4927 if (s->checkfn != Z_NULL)
4928 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4938 /* update pointers */
4948 /* inffast.c -- process literals and length/distance pairs fast
4949 * Copyright (C) 1995-1996 Mark Adler
4950 * For conditions of distribution and use, see copyright notice in zlib.h
4953 /* #include "zutil.h" */
4954 /* #include "inftrees.h" */
4955 /* #include "infblock.h" */
4956 /* #include "infcodes.h" */
4957 /* #include "infutil.h" */
4958 /* #include "inffast.h" */
4960 #ifndef NO_DUMMY_DECL
4961 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4964 /* simplify the use of the inflate_huft type with some defines */
4965 #define base more.Base
4966 #define next more.Next
4967 #define exop word.what.Exop
4968 #define bits word.what.Bits
4970 /* macros for bit input with no checking and for returning unused bytes */
4971 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4972 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4974 /* Called with number of bytes left to write in window at least 258
4975 (the maximum string length) and number of input bytes available
4976 at least ten. The ten bytes are six bytes for the longest length/
4977 distance pair plus four bytes for overloading the bit buffer. */
4979 int inflate_fast(bl, bd, tl, td, s, z)
4982 inflate_huft *td; /* need separate declaration for Borland C++ */
4983 inflate_blocks_statef *s;
4986 inflate_huft *t; /* temporary pointer */
4987 uInt e; /* extra bits or operation */
4988 uLong b; /* bit buffer */
4989 uInt k; /* bits in bit buffer */
4990 Bytef *p; /* input data pointer */
4991 uInt n; /* bytes available there */
4992 Bytef *q; /* output window write pointer */
4993 uInt m; /* bytes to end of window or read pointer */
4994 uInt ml; /* mask for literal/length tree */
4995 uInt md; /* mask for distance tree */
4996 uInt c; /* bytes to copy */
4997 uInt d; /* distance back to copy from */
4998 Bytef *r; /* copy source pointer */
5000 /* load input, output, bit values */
5003 /* initialize masks */
5004 ml = inflate_mask[bl];
5005 md = inflate_mask[bd];
5007 /* do until not enough input or output space for fast loop */
5008 do { /* assume called with m >= 258 && n >= 10 */
5009 /* get literal/length code */
5010 GRABBITS(20) /* max bits for literal/length code */
5011 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5014 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5015 "inflate: * literal '%c'\n" :
5016 "inflate: * literal 0x%02x\n", t->base));
5017 *q++ = (Byte)t->base;
5025 /* get extra bits for length */
5027 c = t->base + ((uInt)b & inflate_mask[e]);
5029 Tracevv((stderr, "inflate: * length %u\n", c));
5031 /* decode distance base of block to copy */
5032 GRABBITS(15); /* max bits for distance code */
5033 e = (t = td + ((uInt)b & md))->exop;
5038 /* get extra bits to add to distance base */
5040 GRABBITS(e) /* get extra bits (up to 13) */
5041 d = t->base + ((uInt)b & inflate_mask[e]);
5043 Tracevv((stderr, "inflate: * distance %u\n", d));
5047 if ((uInt)(q - s->window) >= d) /* offset before dest */
5050 *q++ = *r++; c--; /* minimum count is three, */
5051 *q++ = *r++; c--; /* so unroll loop a little */
5053 else /* else offset after destination */
5055 e = d - (uInt)(q - s->window); /* bytes from offset to end */
5056 r = s->end - e; /* pointer to offset */
5057 if (c > e) /* if source crosses, */
5059 c -= e; /* copy to end of window */
5063 r = s->window; /* copy rest from start of window */
5066 do { /* copy all or what's left */
5071 else if ((e & 64) == 0)
5072 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
5075 z->msg = (char*)"invalid distance code";
5078 return Z_DATA_ERROR;
5085 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
5088 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5089 "inflate: * literal '%c'\n" :
5090 "inflate: * literal 0x%02x\n", t->base));
5091 *q++ = (Byte)t->base;
5098 Tracevv((stderr, "inflate: * end of block\n"));
5101 return Z_STREAM_END;
5105 z->msg = (char*)"invalid literal/length code";
5108 return Z_DATA_ERROR;
5111 } while (m >= 258 && n >= 10);
5113 /* not enough input or output--restore pointers and return */
5121 /* zutil.c -- target dependent utility functions for the compression library
5122 * Copyright (C) 1995-1996 Jean-loup Gailly.
5123 * For conditions of distribution and use, see copyright notice in zlib.h
5126 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */
5132 /* #include "zutil.h" */
5134 #ifndef NO_DUMMY_DECL
5135 struct internal_state {int dummy;}; /* for buggy compilers */
5139 extern void exit OF((int));
5142 static const char *z_errmsg[10] = {
5143 "need dictionary", /* Z_NEED_DICT 2 */
5144 "stream end", /* Z_STREAM_END 1 */
5146 "file error", /* Z_ERRNO (-1) */
5147 "stream error", /* Z_STREAM_ERROR (-2) */
5148 "data error", /* Z_DATA_ERROR (-3) */
5149 "insufficient memory", /* Z_MEM_ERROR (-4) */
5150 "buffer error", /* Z_BUF_ERROR (-5) */
5151 "incompatible version",/* Z_VERSION_ERROR (-6) */
5155 const char *zlibVersion()
5157 return ZLIB_VERSION;
5164 fprintf(stderr, "%s\n", m);
5171 void zmemcpy(dest, source, len)
5176 if (len == 0) return;
5178 *dest++ = *source++; /* ??? to be unrolled */
5179 } while (--len != 0);
5182 int zmemcmp(s1, s2, len)
5189 for (j = 0; j < len; j++) {
5190 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5195 void zmemzero(dest, len)
5199 if (len == 0) return;
5201 *dest++ = 0; /* ??? to be unrolled */
5202 } while (--len != 0);
5207 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5208 /* Small and medium model in Turbo C are for now limited to near allocation
5209 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5213 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5214 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5215 * must fix the pointer. Warning: the pointer must be put back to its
5216 * original form in order to free it, use zcfree().
5222 local int next_ptr = 0;
5224 typedef struct ptr_table_s {
5229 local ptr_table table[MAX_PTR];
5230 /* This table is used to remember the original form of pointers
5231 * to large buffers (64K). Such pointers are normalized with a zero offset.
5232 * Since MSDOS is not a preemptive multitasking OS, this table is not
5233 * protected from concurrent access. This hack doesn't work anyway on
5234 * a protected system like OS/2. Use Microsoft C instead.
5237 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5239 voidpf buf = opaque; /* just to make some compilers happy */
5240 ulg bsize = (ulg)items*size;
5242 /* If we allocate less than 65520 bytes, we assume that farmalloc
5243 * will return a usable pointer which doesn't have to be normalized.
5245 if (bsize < 65520L) {
5246 buf = farmalloc(bsize);
5247 if (*(ush*)&buf != 0) return buf;
5249 buf = farmalloc(bsize + 16L);
5251 if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5252 table[next_ptr].org_ptr = buf;
5254 /* Normalize the pointer to seg:0 */
5255 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5257 table[next_ptr++].new_ptr = buf;
5261 void zcfree (voidpf opaque, voidpf ptr)
5264 if (*(ush*)&ptr != 0) { /* object < 64K */
5268 /* Find the original pointer */
5269 for (n = 0; n < next_ptr; n++) {
5270 if (ptr != table[n].new_ptr) continue;
5272 farfree(table[n].org_ptr);
5273 while (++n < next_ptr) {
5274 table[n-1] = table[n];
5279 ptr = opaque; /* just to make some compilers happy */
5280 Assert(0, "zcfree: ptr not found");
5283 #endif /* __TURBOC__ */
5286 #if defined(M_I86) && !defined(__32BIT__)
5287 /* Microsoft C in 16-bit mode */
5291 #if (!defined(_MSC_VER) || (_MSC_VER < 600))
5292 # define _halloc halloc
5293 # define _hfree hfree
5296 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5298 if (opaque) opaque = 0; /* to make compiler happy */
5299 return _halloc((long)items, size);
5302 void zcfree (voidpf opaque, voidpf ptr)
5304 if (opaque) opaque = 0; /* to make compiler happy */
5311 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5314 extern voidp calloc OF((uInt items, uInt size));
5315 extern void free OF((voidpf ptr));
5318 voidpf zcalloc (opaque, items, size)
5323 if (opaque) items += size - size; /* make compiler happy */
5324 return (voidpf)calloc(items, size);
5327 void zcfree (opaque, ptr)
5332 if (opaque) return; /* make compiler happy */
5335 #endif /* MY_ZCALLOC */
5339 /* adler32.c -- compute the Adler-32 checksum of a data stream
5340 * Copyright (C) 1995-1996 Mark Adler
5341 * For conditions of distribution and use, see copyright notice in zlib.h
5344 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */
5346 /* #include "zlib.h" */
5348 #define BASE 65521L /* largest prime smaller than 65536 */
5350 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5352 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;}
5353 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
5354 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
5355 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
5356 #define DO16(buf) DO8(buf,0); DO8(buf,8);
5358 /* ========================================================================= */
5359 uLong adler32(adler, buf, len)
5364 unsigned long s1 = adler & 0xffff;
5365 unsigned long s2 = (adler >> 16) & 0xffff;
5368 if (buf == Z_NULL) return 1L;
5371 k = len < NMAX ? len : NMAX;
5385 return (s2 << 16) | s1;