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 1.7 2004/12/21 02:54:14 hsu 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(__DragonFly__) || 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/param.h>
58 #include <sys/types.h>
60 #include <sys/systm.h>
62 # define memcpy(d, s, n) bcopy((s), (d), (n))
63 # define memset(d, v, n) bzero((d), (n))
67 #if defined(__KERNEL__)
68 /* Assume this is a Linux kernel */
69 #include <linux/string.h>
72 #else /* not kernel */
74 #if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS)
84 #endif /* __KERNEL__ */
90 /* compile with -Dlocal if your debugger can't find static symbols */
92 typedef unsigned char uch;
94 typedef unsigned short ush;
96 typedef unsigned long ulg;
98 extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
99 /* (size given to avoid silly warnings with Visual C++) */
101 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
103 #define ERR_RETURN(strm,err) \
104 return (strm->msg = (const char*)ERR_MSG(err), (err))
105 /* To be used only when the state is known to be valid */
107 /* common constants */
110 # define DEF_WBITS MAX_WBITS
112 /* default windowBits for decompression. MAX_WBITS is for compression only */
114 #if MAX_MEM_LEVEL >= 8
115 # define DEF_MEM_LEVEL 8
117 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
119 /* default memLevel */
121 #define STORED_BLOCK 0
122 #define STATIC_TREES 1
124 /* The three kinds of block type */
127 #define MAX_MATCH 258
128 /* The minimum and maximum match lengths */
130 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
132 /* target dependencies */
135 # define OS_CODE 0x00
138 # else /* MSC or DJGPP */
144 # define OS_CODE 0x06
147 #ifdef WIN32 /* Window 95 & Windows NT */
148 # define OS_CODE 0x0b
151 #if defined(VAXC) || defined(VMS)
152 # define OS_CODE 0x02
153 # define FOPEN(name, mode) \
154 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
158 # define OS_CODE 0x01
161 #if defined(ATARI) || defined(atarist)
162 # define OS_CODE 0x05
166 # define OS_CODE 0x07
169 #ifdef __50SERIES /* Prime/PRIMOS */
170 # define OS_CODE 0x0F
174 # define OS_CODE 0x0a
177 #if defined(_BEOS_) || defined(RISCOS)
178 # define fdopen(fd,mode) NULL /* No fdopen() */
181 /* Common defaults */
184 # define OS_CODE 0x03 /* assume Unix */
188 # define FOPEN(name, mode) fopen((name), (mode))
194 extern char *strerror OF((int));
195 # define zstrerror(errnum) strerror(errnum)
197 # define zstrerror(errnum) ""
203 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
204 /* Use our own functions for small and medium model with MSC <= 5.0.
205 * You may have to use the same strategy for Borland C (untested).
209 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
213 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */
214 # define zmemcpy _fmemcpy
215 # define zmemcmp _fmemcmp
216 # define zmemzero(dest, len) _fmemset(dest, 0, len)
218 # define zmemcpy memcpy
219 # define zmemcmp memcmp
220 # define zmemzero(dest, len) memset(dest, 0, len)
223 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
224 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len));
225 extern void zmemzero OF((Bytef* dest, uInt len));
228 /* Diagnostic functions */
234 extern void z_error OF((char *m));
235 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
236 # define Trace(x) fprintf x
237 # define Tracev(x) {if (verbose) fprintf x ;}
238 # define Tracevv(x) {if (verbose>1) fprintf x ;}
239 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
240 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
242 # define Assert(cond,msg)
247 # define Tracecv(c,x)
251 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));
253 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
254 void zcfree OF((voidpf opaque, voidpf ptr));
256 #define ZALLOC(strm, items, size) \
257 (*((strm)->zalloc))((strm)->opaque, (items), (size))
258 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
259 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
261 #endif /* _Z_UTIL_H */
265 /* deflate.h -- internal compression state
266 * Copyright (C) 1995-1996 Jean-loup Gailly
267 * For conditions of distribution and use, see copyright notice in zlib.h
270 /* WARNING: this file should *not* be used by applications. It is
271 part of the implementation of the compression library and is
272 subject to change. Applications should only use zlib.h.
275 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */
280 /* #include "zutil.h" */
282 /* ===========================================================================
283 * Internal compression state.
286 #define LENGTH_CODES 29
287 /* number of length codes, not counting the special END_BLOCK code */
290 /* number of literal bytes 0..255 */
292 #define L_CODES (LITERALS+1+LENGTH_CODES)
293 /* number of Literal or Length codes, including the END_BLOCK code */
296 /* number of distance codes */
299 /* number of codes used to transfer the bit lengths */
301 #define HEAP_SIZE (2*L_CODES+1)
302 /* maximum heap size */
305 /* All codes must not exceed MAX_BITS bits */
307 #define INIT_STATE 42
308 #define BUSY_STATE 113
309 #define FINISH_STATE 666
313 /* Data structure describing a single value and its code string. */
314 typedef struct ct_data_s {
316 ush freq; /* frequency count */
317 ush code; /* bit string */
320 ush dad; /* father node in Huffman tree */
321 ush len; /* length of bit string */
330 typedef struct static_tree_desc_s static_tree_desc;
332 typedef struct tree_desc_s {
333 ct_data *dyn_tree; /* the dynamic tree */
334 int max_code; /* largest code with non zero frequency */
335 static_tree_desc *stat_desc; /* the corresponding static tree */
339 typedef Pos FAR Posf;
340 typedef unsigned IPos;
342 /* A Pos is an index in the character window. We use short instead of int to
343 * save space in the various tables. IPos is used only for parameter passing.
346 typedef struct deflate_state {
347 z_streamp strm; /* pointer back to this zlib stream */
348 int status; /* as the name implies */
349 Bytef *pending_buf; /* output still pending */
350 ulg pending_buf_size; /* size of pending_buf */
351 Bytef *pending_out; /* next pending byte to output to the stream */
352 int pending; /* nb of bytes in the pending buffer */
353 int noheader; /* suppress zlib header and adler32 */
354 Byte data_type; /* UNKNOWN, BINARY or ASCII */
355 Byte method; /* STORED (for zip only) or DEFLATED */
356 int last_flush; /* value of flush param for previous deflate call */
358 /* used by deflate.c: */
360 uInt w_size; /* LZ77 window size (32K by default) */
361 uInt w_bits; /* log2(w_size) (8..16) */
362 uInt w_mask; /* w_size - 1 */
365 /* Sliding window. Input bytes are read into the second half of the window,
366 * and move to the first half later to keep a dictionary of at least wSize
367 * bytes. With this organization, matches are limited to a distance of
368 * wSize-MAX_MATCH bytes, but this ensures that IO is always
369 * performed with a length multiple of the block size. Also, it limits
370 * the window size to 64K, which is quite useful on MSDOS.
371 * To do: use the user input buffer as sliding window.
375 /* Actual size of window: 2*wSize, except when the user input buffer
376 * is directly used as sliding window.
380 /* Link to older string with same hash index. To limit the size of this
381 * array to 64K, this link is maintained only for the last 32K strings.
382 * An index in this array is thus a window index modulo 32K.
385 Posf *head; /* Heads of the hash chains or NIL. */
387 uInt ins_h; /* hash index of string to be inserted */
388 uInt hash_size; /* number of elements in hash table */
389 uInt hash_bits; /* log2(hash_size) */
390 uInt hash_mask; /* hash_size-1 */
393 /* Number of bits by which ins_h must be shifted at each input
394 * step. It must be such that after MIN_MATCH steps, the oldest
395 * byte no longer takes part in the hash key, that is:
396 * hash_shift * MIN_MATCH >= hash_bits
400 /* Window position at the beginning of the current output block. Gets
401 * negative when the window is moved backwards.
404 uInt match_length; /* length of best match */
405 IPos prev_match; /* previous match */
406 int match_available; /* set if previous match exists */
407 uInt strstart; /* start of string to insert */
408 uInt match_start; /* start of matching string */
409 uInt lookahead; /* number of valid bytes ahead in window */
412 /* Length of the best match at previous step. Matches not greater than this
413 * are discarded. This is used in the lazy match evaluation.
416 uInt max_chain_length;
417 /* To speed up deflation, hash chains are never searched beyond this
418 * length. A higher limit improves compression ratio but degrades the
423 /* Attempt to find a better match only when the current match is strictly
424 * smaller than this value. This mechanism is used only for compression
427 # define max_insert_length max_lazy_match
428 /* Insert new strings in the hash table only if the match length is not
429 * greater than this length. This saves time but degrades compression.
430 * max_insert_length is used only for compression levels <= 3.
433 int level; /* compression level (1..9) */
434 int strategy; /* favor or force Huffman coding*/
437 /* Use a faster search when the previous match is longer than this */
439 int nice_match; /* Stop searching when current match exceeds this */
441 /* used by trees.c: */
442 /* Didn't use ct_data typedef below to supress compiler warning */
443 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
444 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
445 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
447 struct tree_desc_s l_desc; /* desc. for literal tree */
448 struct tree_desc_s d_desc; /* desc. for distance tree */
449 struct tree_desc_s bl_desc; /* desc. for bit length tree */
451 ush bl_count[MAX_BITS+1];
452 /* number of codes at each bit length for an optimal tree */
454 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
455 int heap_len; /* number of elements in the heap */
456 int heap_max; /* element of largest frequency */
457 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
458 * The same heap array is used to build all trees.
461 uch depth[2*L_CODES+1];
462 /* Depth of each subtree used as tie breaker for trees of equal frequency
465 uchf *l_buf; /* buffer for literals or lengths */
468 /* Size of match buffer for literals/lengths. There are 4 reasons for
469 * limiting lit_bufsize to 64K:
470 * - frequencies can be kept in 16 bit counters
471 * - if compression is not successful for the first block, all input
472 * data is still in the window so we can still emit a stored block even
473 * when input comes from standard input. (This can also be done for
474 * all blocks if lit_bufsize is not greater than 32K.)
475 * - if compression is not successful for a file smaller than 64K, we can
476 * even emit a stored file instead of a stored block (saving 5 bytes).
477 * This is applicable only for zip (not gzip or zlib).
478 * - creating new Huffman trees less frequently may not provide fast
479 * adaptation to changes in the input data statistics. (Take for
480 * example a binary file with poorly compressible code followed by
481 * a highly compressible string table.) Smaller buffer sizes give
482 * fast adaptation but have of course the overhead of transmitting
483 * trees more frequently.
484 * - I can't count above 4
487 uInt last_lit; /* running index in l_buf */
490 /* Buffer for distances. To simplify the code, d_buf and l_buf have
491 * the same number of elements. To use different lengths, an extra flag
492 * array would be necessary.
495 ulg opt_len; /* bit length of current block with optimal trees */
496 ulg static_len; /* bit length of current block with static trees */
497 ulg compressed_len; /* total bit length of compressed file */
498 uInt matches; /* number of string matches in current block */
499 int last_eob_len; /* bit length of EOB code for last block */
502 ulg bits_sent; /* bit length of the compressed data */
506 /* Output buffer. bits are inserted starting at the bottom (least
510 /* Number of valid bits in bi_buf. All bits above the last valid bit
516 /* Output a byte on the stream.
517 * IN assertion: there is enough room in pending_buf.
519 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
522 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
523 /* Minimum amount of lookahead, except at the end of the input file.
524 * See deflate.c for comments about the MIN_MATCH+1.
527 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
528 /* In order to simplify the code, particularly on 16 bit machines, match
529 * distances are limited to MAX_DIST instead of WSIZE.
533 void _tr_init OF((deflate_state *s));
534 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
535 ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
537 void _tr_align OF((deflate_state *s));
538 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
540 void _tr_stored_type_only OF((deflate_state *));
546 /* deflate.c -- compress data using the deflation algorithm
547 * Copyright (C) 1995-1996 Jean-loup Gailly.
548 * For conditions of distribution and use, see copyright notice in zlib.h
554 * The "deflation" process depends on being able to identify portions
555 * of the input text which are identical to earlier input (within a
556 * sliding window trailing behind the input currently being processed).
558 * The most straightforward technique turns out to be the fastest for
559 * most input files: try all possible matches and select the longest.
560 * The key feature of this algorithm is that insertions into the string
561 * dictionary are very simple and thus fast, and deletions are avoided
562 * completely. Insertions are performed at each input character, whereas
563 * string matches are performed only when the previous match ends. So it
564 * is preferable to spend more time in matches to allow very fast string
565 * insertions and avoid deletions. The matching algorithm for small
566 * strings is inspired from that of Rabin & Karp. A brute force approach
567 * is used to find longer strings when a small match has been found.
568 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
569 * (by Leonid Broukhis).
570 * A previous version of this file used a more sophisticated algorithm
571 * (by Fiala and Greene) which is guaranteed to run in linear amortized
572 * time, but has a larger average cost, uses more memory and is patented.
573 * However the F&G algorithm may be faster for some highly redundant
574 * files if the parameter max_chain_length (described below) is too large.
578 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
579 * I found it in 'freeze' written by Leonid Broukhis.
580 * Thanks to many people for bug reports and testing.
584 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
585 * Available in ftp://ds.internic.net/rfc/rfc1951.txt
587 * A description of the Rabin and Karp algorithm is given in the book
588 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
590 * Fiala,E.R., and Greene,D.H.
591 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
595 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */
597 /* #include "deflate.h" */
599 char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly ";
601 If you use the zlib library in a product, an acknowledgment is welcome
602 in the documentation of your product. If for some reason you cannot
603 include such an acknowledgment, I would appreciate that you keep this
604 copyright string in the executable of your product.
607 /* ===========================================================================
608 * Function prototypes.
611 need_more, /* block not completed, need more input or more output */
612 block_done, /* block flush performed */
613 finish_started, /* finish started, need only more output at next deflate */
614 finish_done /* finish done, accept no more input or output */
617 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
618 /* Compression function. Returns the block state after the call. */
620 local void fill_window OF((deflate_state *s));
621 local block_state deflate_stored OF((deflate_state *s, int flush));
622 local block_state deflate_fast OF((deflate_state *s, int flush));
623 local block_state deflate_slow OF((deflate_state *s, int flush));
624 local void lm_init OF((deflate_state *s));
625 local void putShortMSB OF((deflate_state *s, uInt b));
626 local void flush_pending OF((z_streamp strm));
627 local int read_buf OF((z_streamp strm, charf *buf, unsigned size));
629 void match_init OF((void)); /* asm code initialization */
630 uInt longest_match OF((deflate_state *s, IPos cur_match));
632 local uInt longest_match OF((deflate_state *s, IPos cur_match));
636 local void check_match OF((deflate_state *s, IPos start, IPos match,
640 /* ===========================================================================
645 /* Tail of hash chains */
648 # define TOO_FAR 4096
650 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
652 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
653 /* Minimum amount of lookahead, except at the end of the input file.
654 * See deflate.c for comments about the MIN_MATCH+1.
657 /* Values for max_lazy_match, good_match and max_chain_length, depending on
658 * the desired pack level (0..9). The values given below have been tuned to
659 * exclude worst case performance for pathological files. Better values may be
660 * found for specific files.
662 typedef struct config_s {
663 ush good_length; /* reduce lazy search above this match length */
664 ush max_lazy; /* do not perform lazy search above this match length */
665 ush nice_length; /* quit search above this match length */
670 local config configuration_table[10] = {
671 /* good lazy nice chain */
672 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
673 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */
674 /* 2 */ {4, 5, 16, 8, deflate_fast},
675 /* 3 */ {4, 6, 32, 32, deflate_fast},
677 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
678 /* 5 */ {8, 16, 32, 32, deflate_slow},
679 /* 6 */ {8, 16, 128, 128, deflate_slow},
680 /* 7 */ {8, 32, 128, 256, deflate_slow},
681 /* 8 */ {32, 128, 258, 1024, deflate_slow},
682 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
684 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
685 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
690 /* result of memcmp for equal strings */
692 #ifndef NO_DUMMY_DECL
693 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
696 /* ===========================================================================
697 * Update a hash value with the given input byte
698 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
699 * input characters, so that a running hash key can be computed from the
700 * previous key instead of complete recalculation each time.
702 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
705 /* ===========================================================================
706 * Insert string str in the dictionary and set match_head to the previous head
707 * of the hash chain (the most recent string with same hash key). Return
708 * the previous length of the hash chain.
709 * IN assertion: all calls to to INSERT_STRING are made with consecutive
710 * input characters and the first MIN_MATCH bytes of str are valid
711 * (except for the last MIN_MATCH-1 bytes of the input file).
713 #define INSERT_STRING(s, str, match_head) \
714 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
715 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
716 s->head[s->ins_h] = (Pos)(str))
718 /* ===========================================================================
719 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
720 * prev[] will be initialized on the fly.
722 #define CLEAR_HASH(s) \
723 s->head[s->hash_size-1] = NIL; \
724 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
726 /* ========================================================================= */
727 int deflateInit_(strm, level, version, stream_size)
733 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
734 Z_DEFAULT_STRATEGY, version, stream_size);
735 /* To do: ignore strm->next_in if we use it as window */
738 /* ========================================================================= */
739 int deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
740 version, stream_size)
752 static char* my_version = ZLIB_VERSION;
755 /* We overlay pending_buf and d_buf+l_buf. This works since the average
756 * output size for (length,distance) codes is <= 24 bits.
759 if (version == Z_NULL || version[0] != my_version[0] ||
760 stream_size != sizeof(z_stream)) {
761 return Z_VERSION_ERROR;
763 if (strm == Z_NULL) return Z_STREAM_ERROR;
767 if (strm->zalloc == Z_NULL) {
768 strm->zalloc = zcalloc;
769 strm->opaque = (voidpf)0;
771 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
774 if (level == Z_DEFAULT_COMPRESSION) level = 6;
776 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
778 windowBits = -windowBits;
780 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
781 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
782 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
783 return Z_STREAM_ERROR;
785 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
786 if (s == Z_NULL) return Z_MEM_ERROR;
787 strm->state = (struct internal_state FAR *)s;
790 s->noheader = noheader;
791 s->w_bits = windowBits;
792 s->w_size = 1 << s->w_bits;
793 s->w_mask = s->w_size - 1;
795 s->hash_bits = memLevel + 7;
796 s->hash_size = 1 << s->hash_bits;
797 s->hash_mask = s->hash_size - 1;
798 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
800 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
801 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
802 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
804 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
806 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
807 s->pending_buf = (uchf *) overlay;
808 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
810 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
811 s->pending_buf == Z_NULL) {
812 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR);
816 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
817 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
820 s->strategy = strategy;
821 s->method = (Byte)method;
823 return deflateReset(strm);
826 /* ========================================================================= */
827 int deflateSetDictionary (strm, dictionary, dictLength)
829 const Bytef *dictionary;
833 uInt length = dictLength;
837 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
838 return Z_STREAM_ERROR;
840 s = (deflate_state *) strm->state;
841 if (s->status != INIT_STATE) return Z_STREAM_ERROR;
843 strm->adler = adler32(strm->adler, dictionary, dictLength);
845 if (length < MIN_MATCH) return Z_OK;
846 if (length > MAX_DIST(s)) {
847 length = MAX_DIST(s);
848 #ifndef USE_DICT_HEAD
849 dictionary += dictLength - length; /* use the tail of the dictionary */
852 zmemcpy((charf *)s->window, dictionary, length);
853 s->strstart = length;
854 s->block_start = (long)length;
856 /* Insert all strings in the hash table (except for the last two bytes).
857 * s->lookahead stays null, so s->ins_h will be recomputed at the next
858 * call of fill_window.
860 s->ins_h = s->window[0];
861 UPDATE_HASH(s, s->ins_h, s->window[1]);
862 for (n = 0; n <= length - MIN_MATCH; n++) {
863 INSERT_STRING(s, n, hash_head);
865 if (hash_head) hash_head = 0; /* to make compiler happy */
869 /* ========================================================================= */
870 int deflateReset (strm)
875 if (strm == Z_NULL || strm->state == Z_NULL ||
876 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
878 strm->total_in = strm->total_out = 0;
879 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
880 strm->data_type = Z_UNKNOWN;
882 s = (deflate_state *)strm->state;
884 s->pending_out = s->pending_buf;
886 if (s->noheader < 0) {
887 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
889 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
891 s->last_flush = Z_NO_FLUSH;
899 /* ========================================================================= */
900 int deflateParams(strm, level, strategy)
909 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
910 s = (deflate_state *) strm->state;
912 if (level == Z_DEFAULT_COMPRESSION) {
915 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
916 return Z_STREAM_ERROR;
918 func = configuration_table[s->level].func;
920 if (func != configuration_table[level].func && strm->total_in != 0) {
921 /* Flush the last buffer: */
922 err = deflate(strm, Z_PARTIAL_FLUSH);
924 if (s->level != level) {
926 s->max_lazy_match = configuration_table[level].max_lazy;
927 s->good_match = configuration_table[level].good_length;
928 s->nice_match = configuration_table[level].nice_length;
929 s->max_chain_length = configuration_table[level].max_chain;
931 s->strategy = strategy;
935 /* =========================================================================
936 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
937 * IN assertion: the stream state is correct and there is enough room in
940 local void putShortMSB (s, b)
944 put_byte(s, (Byte)(b >> 8));
945 put_byte(s, (Byte)(b & 0xff));
948 /* =========================================================================
949 * Flush as much pending output as possible. All deflate() output goes
950 * through this function so some applications may wish to modify it
951 * to avoid allocating a large strm->next_out buffer and copying into it.
952 * (See also read_buf()).
954 local void flush_pending(strm)
957 deflate_state *s = (deflate_state *) strm->state;
958 unsigned len = s->pending;
960 if (len > strm->avail_out) len = strm->avail_out;
961 if (len == 0) return;
963 if (strm->next_out != Z_NULL) {
964 zmemcpy(strm->next_out, s->pending_out, len);
965 strm->next_out += len;
967 s->pending_out += len;
968 strm->total_out += len;
969 strm->avail_out -= len;
971 if (s->pending == 0) {
972 s->pending_out = s->pending_buf;
976 /* ========================================================================= */
977 int deflate (strm, flush)
981 int old_flush; /* value of flush param for previous deflate call */
984 if (strm == Z_NULL || strm->state == Z_NULL ||
985 flush > Z_FINISH || flush < 0) {
986 return Z_STREAM_ERROR;
988 s = (deflate_state *) strm->state;
990 if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
991 (s->status == FINISH_STATE && flush != Z_FINISH)) {
992 ERR_RETURN(strm, Z_STREAM_ERROR);
994 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
996 s->strm = strm; /* just in case */
997 old_flush = s->last_flush;
998 s->last_flush = flush;
1000 /* Write the zlib header */
1001 if (s->status == INIT_STATE) {
1003 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1004 uInt level_flags = (s->level-1) >> 1;
1006 if (level_flags > 3) level_flags = 3;
1007 header |= (level_flags << 6);
1008 if (s->strstart != 0) header |= PRESET_DICT;
1009 header += 31 - (header % 31);
1011 s->status = BUSY_STATE;
1012 putShortMSB(s, header);
1014 /* Save the adler32 of the preset dictionary: */
1015 if (s->strstart != 0) {
1016 putShortMSB(s, (uInt)(strm->adler >> 16));
1017 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1022 /* Flush as much pending output as possible */
1023 if (s->pending != 0) {
1024 flush_pending(strm);
1025 if (strm->avail_out == 0) {
1026 /* Since avail_out is 0, deflate will be called again with
1027 * more output space, but possibly with both pending and
1028 * avail_in equal to zero. There won't be anything to do,
1029 * but this is not an error situation so make sure we
1030 * return OK instead of BUF_ERROR at next call of deflate:
1036 /* Make sure there is something to do and avoid duplicate consecutive
1037 * flushes. For repeated and useless calls with Z_FINISH, we keep
1038 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1040 } else if (strm->avail_in == 0 && flush <= old_flush &&
1041 flush != Z_FINISH) {
1042 ERR_RETURN(strm, Z_BUF_ERROR);
1045 /* User must not provide more input after the first FINISH: */
1046 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1047 ERR_RETURN(strm, Z_BUF_ERROR);
1050 /* Start a new block or continue the current one.
1052 if (strm->avail_in != 0 || s->lookahead != 0 ||
1053 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1056 bstate = (*(configuration_table[s->level].func))(s, flush);
1058 if (bstate == finish_started || bstate == finish_done) {
1059 s->status = FINISH_STATE;
1061 if (bstate == need_more || bstate == finish_started) {
1062 if (strm->avail_out == 0) {
1063 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1066 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1067 * of deflate should use the same flush parameter to make sure
1068 * that the flush is complete. So we don't have to output an
1069 * empty block here, this will be done at next call. This also
1070 * ensures that for a very small output buffer, we emit at most
1074 if (bstate == block_done) {
1075 if (flush == Z_PARTIAL_FLUSH) {
1077 } else if (flush == Z_PACKET_FLUSH) {
1078 /* Output just the 3-bit `stored' block type value,
1079 but not a zero length. */
1080 _tr_stored_type_only(s);
1081 } else { /* FULL_FLUSH or SYNC_FLUSH */
1082 _tr_stored_block(s, (char*)0, 0L, 0);
1083 /* For a full flush, this empty block will be recognized
1084 * as a special marker by inflate_sync().
1086 if (flush == Z_FULL_FLUSH) {
1087 CLEAR_HASH(s); /* forget history */
1090 flush_pending(strm);
1091 if (strm->avail_out == 0) {
1092 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1097 Assert(strm->avail_out > 0, "bug2");
1099 if (flush != Z_FINISH) return Z_OK;
1100 if (s->noheader) return Z_STREAM_END;
1102 /* Write the zlib trailer (adler32) */
1103 putShortMSB(s, (uInt)(strm->adler >> 16));
1104 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1105 flush_pending(strm);
1106 /* If avail_out is zero, the application will call deflate again
1107 * to flush the rest.
1109 s->noheader = -1; /* write the trailer only once! */
1110 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1113 /* ========================================================================= */
1114 int deflateEnd (strm)
1120 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1121 s = (deflate_state *) strm->state;
1124 if (status != INIT_STATE && status != BUSY_STATE &&
1125 status != FINISH_STATE) {
1126 return Z_STREAM_ERROR;
1129 /* Deallocate in reverse order of allocations: */
1130 TRY_FREE(strm, s->pending_buf);
1131 TRY_FREE(strm, s->head);
1132 TRY_FREE(strm, s->prev);
1133 TRY_FREE(strm, s->window);
1136 strm->state = Z_NULL;
1138 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1141 /* =========================================================================
1142 * Copy the source state to the destination state.
1144 int deflateCopy (dest, source)
1152 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
1153 return Z_STREAM_ERROR;
1154 ss = (deflate_state *) source->state;
1156 zmemcpy(dest, source, sizeof(*dest));
1158 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1159 if (ds == Z_NULL) return Z_MEM_ERROR;
1160 dest->state = (struct internal_state FAR *) ds;
1161 zmemcpy(ds, ss, sizeof(*ds));
1164 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1165 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1166 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1167 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1168 ds->pending_buf = (uchf *) overlay;
1170 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1171 ds->pending_buf == Z_NULL) {
1175 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */
1176 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1177 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1178 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1179 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1181 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1182 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1183 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1185 ds->l_desc.dyn_tree = ds->dyn_ltree;
1186 ds->d_desc.dyn_tree = ds->dyn_dtree;
1187 ds->bl_desc.dyn_tree = ds->bl_tree;
1192 /* ===========================================================================
1193 * Return the number of bytes of output which are immediately available
1194 * for output from the decompressor.
1196 int deflateOutputPending (strm)
1199 if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1201 return ((deflate_state *)(strm->state))->pending;
1204 /* ===========================================================================
1205 * Read a new buffer from the current input stream, update the adler32
1206 * and total number of bytes read. All deflate() input goes through
1207 * this function so some applications may wish to modify it to avoid
1208 * allocating a large strm->next_in buffer and copying from it.
1209 * (See also flush_pending()).
1211 local int read_buf(strm, buf, size)
1216 unsigned len = strm->avail_in;
1218 if (len > size) len = size;
1219 if (len == 0) return 0;
1221 strm->avail_in -= len;
1223 if (!((deflate_state *)(strm->state))->noheader) {
1224 strm->adler = adler32(strm->adler, strm->next_in, len);
1226 zmemcpy(buf, strm->next_in, len);
1227 strm->next_in += len;
1228 strm->total_in += len;
1233 /* ===========================================================================
1234 * Initialize the "longest match" routines for a new zlib stream
1236 local void lm_init (s)
1239 s->window_size = (ulg)2L*s->w_size;
1243 /* Set the default configuration parameters:
1245 s->max_lazy_match = configuration_table[s->level].max_lazy;
1246 s->good_match = configuration_table[s->level].good_length;
1247 s->nice_match = configuration_table[s->level].nice_length;
1248 s->max_chain_length = configuration_table[s->level].max_chain;
1251 s->block_start = 0L;
1253 s->match_length = s->prev_length = MIN_MATCH-1;
1254 s->match_available = 0;
1257 match_init(); /* initialize the asm code */
1261 /* ===========================================================================
1262 * Set match_start to the longest match starting at the given string and
1263 * return its length. Matches shorter or equal to prev_length are discarded,
1264 * in which case the result is equal to prev_length and match_start is
1266 * IN assertions: cur_match is the head of the hash chain for the current
1267 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1268 * OUT assertion: the match length is not greater than s->lookahead.
1271 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1272 * match.S. The code will be functionally equivalent.
1274 local uInt longest_match(s, cur_match)
1276 IPos cur_match; /* current match */
1278 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1279 Bytef *scan = s->window + s->strstart; /* current string */
1280 Bytef *match; /* matched string */
1281 int len; /* length of current match */
1282 int best_len = s->prev_length; /* best match length so far */
1283 int nice_match = s->nice_match; /* stop if match long enough */
1284 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1285 s->strstart - (IPos)MAX_DIST(s) : NIL;
1286 /* Stop when cur_match becomes <= limit. To simplify the code,
1287 * we prevent matches with the string of window index 0.
1289 Posf *prev = s->prev;
1290 uInt wmask = s->w_mask;
1293 /* Compare two bytes at a time. Note: this is not always beneficial.
1294 * Try with and without -DUNALIGNED_OK to check.
1296 Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1297 ush scan_start = *(ushf*)scan;
1298 ush scan_end = *(ushf*)(scan+best_len-1);
1300 Bytef *strend = s->window + s->strstart + MAX_MATCH;
1301 Byte scan_end1 = scan[best_len-1];
1302 Byte scan_end = scan[best_len];
1305 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1306 * It is easy to get rid of this optimization if necessary.
1308 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1310 /* Do not waste too much time if we already have a good match: */
1311 if (s->prev_length >= s->good_match) {
1314 /* Do not look for matches beyond the end of the input. This is necessary
1315 * to make deflate deterministic.
1317 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1319 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1322 Assert(cur_match < s->strstart, "no future");
1323 match = s->window + cur_match;
1325 /* Skip to next match if the match length cannot increase
1326 * or if the match length is less than 2:
1328 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1329 /* This code assumes sizeof(unsigned short) == 2. Do not use
1330 * UNALIGNED_OK if your compiler uses a different size.
1332 if (*(ushf*)(match+best_len-1) != scan_end ||
1333 *(ushf*)match != scan_start) continue;
1335 /* It is not necessary to compare scan[2] and match[2] since they are
1336 * always equal when the other bytes match, given that the hash keys
1337 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1338 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1339 * lookahead only every 4th comparison; the 128th check will be made
1340 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1341 * necessary to put more guard bytes at the end of the window, or
1342 * to check more often for insufficient lookahead.
1344 Assert(scan[2] == match[2], "scan[2]?");
1347 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1348 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1349 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1350 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1352 /* The funny "do {}" generates better code on most compilers */
1354 /* Here, scan <= window+strstart+257 */
1355 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1356 if (*scan == *match) scan++;
1358 len = (MAX_MATCH - 1) - (int)(strend-scan);
1359 scan = strend - (MAX_MATCH-1);
1361 #else /* UNALIGNED_OK */
1363 if (match[best_len] != scan_end ||
1364 match[best_len-1] != scan_end1 ||
1366 *++match != scan[1]) continue;
1368 /* The check at best_len-1 can be removed because it will be made
1369 * again later. (This heuristic is not always a win.)
1370 * It is not necessary to compare scan[2] and match[2] since they
1371 * are always equal when the other bytes match, given that
1372 * the hash keys are equal and that HASH_BITS >= 8.
1375 Assert(*scan == *match, "match[2]?");
1377 /* We check for insufficient lookahead only every 8th comparison;
1378 * the 256th check will be made at strstart+258.
1381 } while (*++scan == *++match && *++scan == *++match &&
1382 *++scan == *++match && *++scan == *++match &&
1383 *++scan == *++match && *++scan == *++match &&
1384 *++scan == *++match && *++scan == *++match &&
1387 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1389 len = MAX_MATCH - (int)(strend - scan);
1390 scan = strend - MAX_MATCH;
1392 #endif /* UNALIGNED_OK */
1394 if (len > best_len) {
1395 s->match_start = cur_match;
1397 if (len >= nice_match) break;
1399 scan_end = *(ushf*)(scan+best_len-1);
1401 scan_end1 = scan[best_len-1];
1402 scan_end = scan[best_len];
1405 } while ((cur_match = prev[cur_match & wmask]) > limit
1406 && --chain_length != 0);
1408 if ((uInt)best_len <= s->lookahead) return best_len;
1409 return s->lookahead;
1414 /* ===========================================================================
1415 * Check that the match at match_start is indeed a match.
1417 local void check_match(s, start, match, length)
1422 /* check that the match is indeed a match */
1423 if (zmemcmp((charf *)s->window + match,
1424 (charf *)s->window + start, length) != EQUAL) {
1425 fprintf(stderr, " start %u, match %u, length %d\n",
1426 start, match, length);
1428 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1429 } while (--length != 0);
1430 z_error("invalid match");
1432 if (z_verbose > 1) {
1433 fprintf(stderr,"\\[%d,%d]", start-match, length);
1434 do { putc(s->window[start++], stderr); } while (--length != 0);
1438 # define check_match(s, start, match, length)
1441 /* ===========================================================================
1442 * Fill the window when the lookahead becomes insufficient.
1443 * Updates strstart and lookahead.
1445 * IN assertion: lookahead < MIN_LOOKAHEAD
1446 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1447 * At least one byte has been read, or avail_in == 0; reads are
1448 * performed for at least two bytes (required for the zip translate_eol
1449 * option -- not supported here).
1451 local void fill_window(s)
1456 unsigned more; /* Amount of free space at the end of the window. */
1457 uInt wsize = s->w_size;
1460 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1462 /* Deal with !@#$% 64K limit: */
1463 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1466 } else if (more == (unsigned)(-1)) {
1467 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1468 * and lookahead == 1 (input done one byte at time)
1472 /* If the window is almost full and there is insufficient lookahead,
1473 * move the upper half to the lower one to make room in the upper half.
1475 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1477 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1479 s->match_start -= wsize;
1480 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1481 s->block_start -= (long) wsize;
1483 /* Slide the hash table (could be avoided with 32 bit values
1484 at the expense of memory usage). We slide even when level == 0
1485 to keep the hash table consistent if we switch back to level > 0
1486 later. (Using level 0 permanently is not an optimal usage of
1487 zlib, so we don't care about this pathological case.)
1493 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1500 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1501 /* If n is not on any hash chain, prev[n] is garbage but
1502 * its value will never be used.
1507 if (s->strm->avail_in == 0) return;
1509 /* If there was no sliding:
1510 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1511 * more == window_size - lookahead - strstart
1512 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1513 * => more >= window_size - 2*WSIZE + 2
1514 * In the BIG_MEM or MMAP case (not yet supported),
1515 * window_size == input_size + MIN_LOOKAHEAD &&
1516 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1517 * Otherwise, window_size == 2*WSIZE so more >= 2.
1518 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1520 Assert(more >= 2, "more < 2");
1522 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1526 /* Initialize the hash value now that we have some input: */
1527 if (s->lookahead >= MIN_MATCH) {
1528 s->ins_h = s->window[s->strstart];
1529 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1531 Call UPDATE_HASH() MIN_MATCH-3 more times
1534 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1535 * but this is not important since only literal bytes will be emitted.
1538 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1541 /* ===========================================================================
1542 * Flush the current block, with given end-of-file flag.
1543 * IN assertion: strstart is set to the end of the current match.
1545 #define FLUSH_BLOCK_ONLY(s, eof) { \
1546 _tr_flush_block(s, (s->block_start >= 0L ? \
1547 (charf *)&s->window[(unsigned)s->block_start] : \
1549 (ulg)((long)s->strstart - s->block_start), \
1551 s->block_start = s->strstart; \
1552 flush_pending(s->strm); \
1553 Tracev((stderr,"[FLUSH]")); \
1556 /* Same but force premature exit if necessary. */
1557 #define FLUSH_BLOCK(s, eof) { \
1558 FLUSH_BLOCK_ONLY(s, eof); \
1559 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1562 /* ===========================================================================
1563 * Copy without compression as much as possible from the input stream, return
1564 * the current block state.
1565 * This function does not insert new strings in the dictionary since
1566 * uncompressible data is probably not useful. This function is used
1567 * only for the level=0 compression option.
1568 * NOTE: this function should be optimized to avoid extra copying from
1569 * window to pending_buf.
1571 local block_state deflate_stored(s, flush)
1575 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1576 * to pending_buf_size, and each stored block has a 5 byte header:
1578 ulg max_block_size = 0xffff;
1581 if (max_block_size > s->pending_buf_size - 5) {
1582 max_block_size = s->pending_buf_size - 5;
1585 /* Copy as much as possible from input to output: */
1587 /* Fill the window as much as possible: */
1588 if (s->lookahead <= 1) {
1590 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1591 s->block_start >= (long)s->w_size, "slide too late");
1594 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1596 if (s->lookahead == 0) break; /* flush the current block */
1598 Assert(s->block_start >= 0L, "block gone");
1600 s->strstart += s->lookahead;
1603 /* Emit a stored block if pending_buf will be full: */
1604 max_start = s->block_start + max_block_size;
1605 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1606 /* strstart == 0 is possible when wraparound on 16-bit machine */
1607 s->lookahead = (uInt)(s->strstart - max_start);
1608 s->strstart = (uInt)max_start;
1611 /* Flush if we may have to slide, otherwise block_start may become
1612 * negative and the data will be gone:
1614 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1618 FLUSH_BLOCK(s, flush == Z_FINISH);
1619 return flush == Z_FINISH ? finish_done : block_done;
1622 /* ===========================================================================
1623 * Compress as much as possible from the input stream, return the current
1625 * This function does not perform lazy evaluation of matches and inserts
1626 * new strings in the dictionary only for unmatched strings or for short
1627 * matches. It is used only for the fast compression options.
1629 local block_state deflate_fast(s, flush)
1633 IPos hash_head = NIL; /* head of the hash chain */
1634 int bflush; /* set if current block must be flushed */
1637 /* Make sure that we always have enough lookahead, except
1638 * at the end of the input file. We need MAX_MATCH bytes
1639 * for the next match, plus MIN_MATCH bytes to insert the
1640 * string following the next match.
1642 if (s->lookahead < MIN_LOOKAHEAD) {
1644 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1647 if (s->lookahead == 0) break; /* flush the current block */
1650 /* Insert the string window[strstart .. strstart+2] in the
1651 * dictionary, and set hash_head to the head of the hash chain:
1653 if (s->lookahead >= MIN_MATCH) {
1654 INSERT_STRING(s, s->strstart, hash_head);
1657 /* Find the longest match, discarding those <= prev_length.
1658 * At this point we have always match_length < MIN_MATCH
1660 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1661 /* To simplify the code, we prevent matches with the string
1662 * of window index 0 (in particular we have to avoid a match
1663 * of the string with itself at the start of the input file).
1665 if (s->strategy != Z_HUFFMAN_ONLY) {
1666 s->match_length = longest_match (s, hash_head);
1668 /* longest_match() sets match_start */
1670 if (s->match_length >= MIN_MATCH) {
1671 check_match(s, s->strstart, s->match_start, s->match_length);
1673 bflush = _tr_tally(s, s->strstart - s->match_start,
1674 s->match_length - MIN_MATCH);
1676 s->lookahead -= s->match_length;
1678 /* Insert new strings in the hash table only if the match length
1679 * is not too large. This saves time but degrades compression.
1681 if (s->match_length <= s->max_insert_length &&
1682 s->lookahead >= MIN_MATCH) {
1683 s->match_length--; /* string at strstart already in hash table */
1686 INSERT_STRING(s, s->strstart, hash_head);
1687 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1688 * always MIN_MATCH bytes ahead.
1690 } while (--s->match_length != 0);
1693 s->strstart += s->match_length;
1694 s->match_length = 0;
1695 s->ins_h = s->window[s->strstart];
1696 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1698 Call UPDATE_HASH() MIN_MATCH-3 more times
1700 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1701 * matter since it will be recomputed at next deflate call.
1705 /* No match, output a literal byte */
1706 Tracevv((stderr,"%c", s->window[s->strstart]));
1707 bflush = _tr_tally (s, 0, s->window[s->strstart]);
1711 if (bflush) FLUSH_BLOCK(s, 0);
1713 FLUSH_BLOCK(s, flush == Z_FINISH);
1714 return flush == Z_FINISH ? finish_done : block_done;
1717 /* ===========================================================================
1718 * Same as above, but achieves better compression. We use a lazy
1719 * evaluation for matches: a match is finally adopted only if there is
1720 * no better match at the next window position.
1722 local block_state deflate_slow(s, flush)
1726 IPos hash_head = NIL; /* head of hash chain */
1727 int bflush; /* set if current block must be flushed */
1729 /* Process the input block. */
1731 /* Make sure that we always have enough lookahead, except
1732 * at the end of the input file. We need MAX_MATCH bytes
1733 * for the next match, plus MIN_MATCH bytes to insert the
1734 * string following the next match.
1736 if (s->lookahead < MIN_LOOKAHEAD) {
1738 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1741 if (s->lookahead == 0) break; /* flush the current block */
1744 /* Insert the string window[strstart .. strstart+2] in the
1745 * dictionary, and set hash_head to the head of the hash chain:
1747 if (s->lookahead >= MIN_MATCH) {
1748 INSERT_STRING(s, s->strstart, hash_head);
1751 /* Find the longest match, discarding those <= prev_length.
1753 s->prev_length = s->match_length, s->prev_match = s->match_start;
1754 s->match_length = MIN_MATCH-1;
1756 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1757 s->strstart - hash_head <= MAX_DIST(s)) {
1758 /* To simplify the code, we prevent matches with the string
1759 * of window index 0 (in particular we have to avoid a match
1760 * of the string with itself at the start of the input file).
1762 if (s->strategy != Z_HUFFMAN_ONLY) {
1763 s->match_length = longest_match (s, hash_head);
1765 /* longest_match() sets match_start */
1767 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1768 (s->match_length == MIN_MATCH &&
1769 s->strstart - s->match_start > TOO_FAR))) {
1771 /* If prev_match is also MIN_MATCH, match_start is garbage
1772 * but we will ignore the current match anyway.
1774 s->match_length = MIN_MATCH-1;
1777 /* If there was a match at the previous step and the current
1778 * match is not better, output the previous match:
1780 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1781 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1782 /* Do not insert strings in hash table beyond this. */
1784 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1786 bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
1787 s->prev_length - MIN_MATCH);
1789 /* Insert in hash table all strings up to the end of the match.
1790 * strstart-1 and strstart are already inserted. If there is not
1791 * enough lookahead, the last two strings are not inserted in
1794 s->lookahead -= s->prev_length-1;
1795 s->prev_length -= 2;
1797 if (++s->strstart <= max_insert) {
1798 INSERT_STRING(s, s->strstart, hash_head);
1800 } while (--s->prev_length != 0);
1801 s->match_available = 0;
1802 s->match_length = MIN_MATCH-1;
1805 if (bflush) FLUSH_BLOCK(s, 0);
1807 } else if (s->match_available) {
1808 /* If there was no match at the previous position, output a
1809 * single literal. If there was a match but the current match
1810 * is longer, truncate the previous match to a single literal.
1812 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1813 if (_tr_tally (s, 0, s->window[s->strstart-1])) {
1814 FLUSH_BLOCK_ONLY(s, 0);
1818 if (s->strm->avail_out == 0) return need_more;
1820 /* There is no previous match to compare with, wait for
1821 * the next step to decide.
1823 s->match_available = 1;
1828 Assert (flush != Z_NO_FLUSH, "no flush?");
1829 if (s->match_available) {
1830 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1831 _tr_tally (s, 0, s->window[s->strstart-1]);
1832 s->match_available = 0;
1834 FLUSH_BLOCK(s, flush == Z_FINISH);
1835 return flush == Z_FINISH ? finish_done : block_done;
1840 /* trees.c -- output deflated data using Huffman coding
1841 * Copyright (C) 1995-1996 Jean-loup Gailly
1842 * For conditions of distribution and use, see copyright notice in zlib.h
1848 * The "deflation" process uses several Huffman trees. The more
1849 * common source values are represented by shorter bit sequences.
1851 * Each code tree is stored in a compressed form which is itself
1852 * a Huffman encoding of the lengths of all the code strings (in
1853 * ascending order by source values). The actual code strings are
1854 * reconstructed from the lengths in the inflate process, as described
1855 * in the deflate specification.
1859 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1860 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1863 * Data Compression: Methods and Theory, pp. 49-50.
1864 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1868 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1871 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
1873 /* #include "deflate.h" */
1879 /* ===========================================================================
1883 #define MAX_BL_BITS 7
1884 /* Bit length codes must not exceed MAX_BL_BITS bits */
1886 #define END_BLOCK 256
1887 /* end of block literal code */
1890 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1892 #define REPZ_3_10 17
1893 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1895 #define REPZ_11_138 18
1896 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1898 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1899 = {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};
1901 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1902 = {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};
1904 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1905 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1907 local uch bl_order[BL_CODES]
1908 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1909 /* The lengths of the bit length codes are sent in order of decreasing
1910 * probability, to avoid transmitting the lengths for unused bit length codes.
1913 #define Buf_size (8 * 2*sizeof(char))
1914 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1915 * more than 16 bits on some systems.)
1918 /* ===========================================================================
1919 * Local data. These are initialized only once.
1922 local ct_data static_ltree[L_CODES+2];
1923 /* The static literal tree. Since the bit lengths are imposed, there is no
1924 * need for the L_CODES extra codes used during heap construction. However
1925 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
1929 local ct_data static_dtree[D_CODES];
1930 /* The static distance tree. (Actually a trivial tree since all codes use
1934 local uch dist_code[512];
1935 /* distance codes. The first 256 values correspond to the distances
1936 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1937 * the 15 bit distances.
1940 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1941 /* length code for each normalized match length (0 == MIN_MATCH) */
1943 local int base_length[LENGTH_CODES];
1944 /* First normalized length for each code (0 = MIN_MATCH) */
1946 local int base_dist[D_CODES];
1947 /* First normalized distance for each code (0 = distance of 1) */
1949 struct static_tree_desc_s {
1950 ct_data *static_tree; /* static tree or NULL */
1951 intf *extra_bits; /* extra bits for each code or NULL */
1952 int extra_base; /* base index for extra_bits */
1953 int elems; /* max number of elements in the tree */
1954 int max_length; /* max bit length for the codes */
1957 local static_tree_desc static_l_desc =
1958 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1960 local static_tree_desc static_d_desc =
1961 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1963 local static_tree_desc static_bl_desc =
1964 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1966 /* ===========================================================================
1967 * Local (static) routines in this file.
1970 local void tr_static_init OF((void));
1971 local void init_block OF((deflate_state *s));
1972 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1973 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1974 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1975 local void build_tree OF((deflate_state *s, tree_desc *desc));
1976 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1977 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1978 local int build_bl_tree OF((deflate_state *s));
1979 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1981 local void compress_block OF((deflate_state *s, ct_data *ltree,
1983 local void set_data_type OF((deflate_state *s));
1984 local unsigned bi_reverse OF((unsigned value, int length));
1985 local void bi_windup OF((deflate_state *s));
1986 local void bi_flush OF((deflate_state *s));
1987 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1991 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1992 /* Send a code of the given tree. c and tree must not have side effects */
1994 #else /* DEBUG_ZLIB */
1995 # define send_code(s, c, tree) \
1996 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
1997 send_bits(s, tree[c].Code, tree[c].Len); }
2000 #define d_code(dist) \
2001 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
2002 /* Mapping from a distance to a distance code. dist is the distance - 1 and
2003 * must not have side effects. dist_code[256] and dist_code[257] are never
2007 /* ===========================================================================
2008 * Output a short LSB first on the stream.
2009 * IN assertion: there is enough room in pendingBuf.
2011 #define put_short(s, w) { \
2012 put_byte(s, (uch)((w) & 0xff)); \
2013 put_byte(s, (uch)((ush)(w) >> 8)); \
2016 /* ===========================================================================
2017 * Send a value on a given number of bits.
2018 * IN assertion: length <= 16 and value fits in length bits.
2021 local void send_bits OF((deflate_state *s, int value, int length));
2023 local void send_bits(s, value, length)
2025 int value; /* value to send */
2026 int length; /* number of bits */
2028 Tracevv((stderr," l %2d v %4x ", length, value));
2029 Assert(length > 0 && length <= 15, "invalid length");
2030 s->bits_sent += (ulg)length;
2032 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2033 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2034 * unused bits in value.
2036 if (s->bi_valid > (int)Buf_size - length) {
2037 s->bi_buf |= (value << s->bi_valid);
2038 put_short(s, s->bi_buf);
2039 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2040 s->bi_valid += length - Buf_size;
2042 s->bi_buf |= value << s->bi_valid;
2043 s->bi_valid += length;
2046 #else /* !DEBUG_ZLIB */
2048 #define send_bits(s, value, length) \
2049 { int len = length;\
2050 if (s->bi_valid > (int)Buf_size - len) {\
2052 s->bi_buf |= (val << s->bi_valid);\
2053 put_short(s, s->bi_buf);\
2054 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2055 s->bi_valid += len - Buf_size;\
2057 s->bi_buf |= (value) << s->bi_valid;\
2058 s->bi_valid += len;\
2061 #endif /* DEBUG_ZLIB */
2063 /* the arguments must not have side effects */
2065 /* ===========================================================================
2066 * Initialize the various 'constant' tables. In a multi-threaded environment,
2067 * this function may be called by two threads concurrently, but this is
2068 * harmless since both invocations do exactly the same thing.
2070 local void tr_static_init()
2072 static int static_init_done = 0;
2073 int n; /* iterates over tree elements */
2074 int bits; /* bit counter */
2075 int length; /* length value */
2076 int code; /* code value */
2077 int dist; /* distance index */
2078 ush bl_count[MAX_BITS+1];
2079 /* number of codes at each bit length for an optimal tree */
2081 if (static_init_done) return;
2083 /* Initialize the mapping length (0..255) -> length code (0..28) */
2085 for (code = 0; code < LENGTH_CODES-1; code++) {
2086 base_length[code] = length;
2087 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2088 length_code[length++] = (uch)code;
2091 Assert (length == 256, "tr_static_init: length != 256");
2092 /* Note that the length 255 (match length 258) can be represented
2093 * in two different ways: code 284 + 5 bits or code 285, so we
2094 * overwrite length_code[255] to use the best encoding:
2096 length_code[length-1] = (uch)code;
2098 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2100 for (code = 0 ; code < 16; code++) {
2101 base_dist[code] = dist;
2102 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2103 dist_code[dist++] = (uch)code;
2106 Assert (dist == 256, "tr_static_init: dist != 256");
2107 dist >>= 7; /* from now on, all distances are divided by 128 */
2108 for ( ; code < D_CODES; code++) {
2109 base_dist[code] = dist << 7;
2110 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2111 dist_code[256 + dist++] = (uch)code;
2114 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2116 /* Construct the codes of the static literal tree */
2117 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2119 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2120 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2121 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2122 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2123 /* Codes 286 and 287 do not exist, but we must include them in the
2124 * tree construction to get a canonical Huffman tree (longest code
2127 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2129 /* The static distance tree is trivial: */
2130 for (n = 0; n < D_CODES; n++) {
2131 static_dtree[n].Len = 5;
2132 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2134 static_init_done = 1;
2137 /* ===========================================================================
2138 * Initialize the tree data structures for a new zlib stream.
2145 s->compressed_len = 0L;
2147 s->l_desc.dyn_tree = s->dyn_ltree;
2148 s->l_desc.stat_desc = &static_l_desc;
2150 s->d_desc.dyn_tree = s->dyn_dtree;
2151 s->d_desc.stat_desc = &static_d_desc;
2153 s->bl_desc.dyn_tree = s->bl_tree;
2154 s->bl_desc.stat_desc = &static_bl_desc;
2158 s->last_eob_len = 8; /* enough lookahead for inflate */
2163 /* Initialize the first block of the first file: */
2167 /* ===========================================================================
2168 * Initialize a new block.
2170 local void init_block(s)
2173 int n; /* iterates over tree elements */
2175 /* Initialize the trees. */
2176 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2177 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2178 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2180 s->dyn_ltree[END_BLOCK].Freq = 1;
2181 s->opt_len = s->static_len = 0L;
2182 s->last_lit = s->matches = 0;
2186 /* Index within the heap array of least frequent node in the Huffman tree */
2189 /* ===========================================================================
2190 * Remove the smallest element from the heap and recreate the heap with
2191 * one less element. Updates heap and heap_len.
2193 #define pqremove(s, tree, top) \
2195 top = s->heap[SMALLEST]; \
2196 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2197 pqdownheap(s, tree, SMALLEST); \
2200 /* ===========================================================================
2201 * Compares to subtrees, using the tree depth as tie breaker when
2202 * the subtrees have equal frequency. This minimizes the worst case length.
2204 #define smaller(tree, n, m, depth) \
2205 (tree[n].Freq < tree[m].Freq || \
2206 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2208 /* ===========================================================================
2209 * Restore the heap property by moving down the tree starting at node k,
2210 * exchanging a node with the smallest of its two sons if necessary, stopping
2211 * when the heap property is re-established (each father smaller than its
2214 local void pqdownheap(s, tree, k)
2216 ct_data *tree; /* the tree to restore */
2217 int k; /* node to move down */
2220 int j = k << 1; /* left son of k */
2221 while (j <= s->heap_len) {
2222 /* Set j to the smallest of the two sons: */
2223 if (j < s->heap_len &&
2224 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2227 /* Exit if v is smaller than both sons */
2228 if (smaller(tree, v, s->heap[j], s->depth)) break;
2230 /* Exchange v with the smallest son */
2231 s->heap[k] = s->heap[j]; k = j;
2233 /* And continue down the tree, setting j to the left son of k */
2239 /* ===========================================================================
2240 * Compute the optimal bit lengths for a tree and update the total bit length
2241 * for the current block.
2242 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2243 * above are the tree nodes sorted by increasing frequency.
2244 * OUT assertions: the field len is set to the optimal bit length, the
2245 * array bl_count contains the frequencies for each bit length.
2246 * The length opt_len is updated; static_len is also updated if stree is
2249 local void gen_bitlen(s, desc)
2251 tree_desc *desc; /* the tree descriptor */
2253 ct_data *tree = desc->dyn_tree;
2254 int max_code = desc->max_code;
2255 ct_data *stree = desc->stat_desc->static_tree;
2256 intf *extra = desc->stat_desc->extra_bits;
2257 int base = desc->stat_desc->extra_base;
2258 int max_length = desc->stat_desc->max_length;
2259 int h; /* heap index */
2260 int n, m; /* iterate over the tree elements */
2261 int bits; /* bit length */
2262 int xbits; /* extra bits */
2263 ush f; /* frequency */
2264 int overflow = 0; /* number of elements with bit length too large */
2266 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2268 /* In a first pass, compute the optimal bit lengths (which may
2269 * overflow in the case of the bit length tree).
2271 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2273 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2275 bits = tree[tree[n].Dad].Len + 1;
2276 if (bits > max_length) bits = max_length, overflow++;
2277 tree[n].Len = (ush)bits;
2278 /* We overwrite tree[n].Dad which is no longer needed */
2280 if (n > max_code) continue; /* not a leaf node */
2282 s->bl_count[bits]++;
2284 if (n >= base) xbits = extra[n-base];
2286 s->opt_len += (ulg)f * (bits + xbits);
2287 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2289 if (overflow == 0) return;
2291 Trace((stderr,"\nbit length overflow\n"));
2292 /* This happens for example on obj2 and pic of the Calgary corpus */
2294 /* Find the first bit length which could increase: */
2296 bits = max_length-1;
2297 while (s->bl_count[bits] == 0) bits--;
2298 s->bl_count[bits]--; /* move one leaf down the tree */
2299 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2300 s->bl_count[max_length]--;
2301 /* The brother of the overflow item also moves one step up,
2302 * but this does not affect bl_count[max_length]
2305 } while (overflow > 0);
2307 /* Now recompute all bit lengths, scanning in increasing frequency.
2308 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2309 * lengths instead of fixing only the wrong ones. This idea is taken
2310 * from 'ar' written by Haruhiko Okumura.)
2312 for (bits = max_length; bits != 0; bits--) {
2313 n = s->bl_count[bits];
2316 if (m > max_code) continue;
2317 if (tree[m].Len != (unsigned) bits) {
2318 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2319 s->opt_len += ((long)bits - (long)tree[m].Len)
2320 *(long)tree[m].Freq;
2321 tree[m].Len = (ush)bits;
2328 /* ===========================================================================
2329 * Generate the codes for a given tree and bit counts (which need not be
2331 * IN assertion: the array bl_count contains the bit length statistics for
2332 * the given tree and the field len is set for all tree elements.
2333 * OUT assertion: the field code is set for all tree elements of non
2336 local void gen_codes (tree, max_code, bl_count)
2337 ct_data *tree; /* the tree to decorate */
2338 int max_code; /* largest code with non zero frequency */
2339 ushf *bl_count; /* number of codes at each bit length */
2341 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2342 ush code = 0; /* running code value */
2343 int bits; /* bit index */
2344 int n; /* code index */
2346 /* The distribution counts are first used to generate the code values
2347 * without bit reversal.
2349 for (bits = 1; bits <= MAX_BITS; bits++) {
2350 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2352 /* Check that the bit counts in bl_count are consistent. The last code
2355 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2356 "inconsistent bit counts");
2357 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2359 for (n = 0; n <= max_code; n++) {
2360 int len = tree[n].Len;
2361 if (len == 0) continue;
2362 /* Now reverse the bits */
2363 tree[n].Code = bi_reverse(next_code[len]++, len);
2365 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2366 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2370 /* ===========================================================================
2371 * Construct one Huffman tree and assigns the code bit strings and lengths.
2372 * Update the total bit length for the current block.
2373 * IN assertion: the field freq is set for all tree elements.
2374 * OUT assertions: the fields len and code are set to the optimal bit length
2375 * and corresponding code. The length opt_len is updated; static_len is
2376 * also updated if stree is not null. The field max_code is set.
2378 local void build_tree(s, desc)
2380 tree_desc *desc; /* the tree descriptor */
2382 ct_data *tree = desc->dyn_tree;
2383 ct_data *stree = desc->stat_desc->static_tree;
2384 int elems = desc->stat_desc->elems;
2385 int n, m; /* iterate over heap elements */
2386 int max_code = -1; /* largest code with non zero frequency */
2387 int node; /* new node being created */
2389 /* Construct the initial heap, with least frequent element in
2390 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2391 * heap[0] is not used.
2393 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2395 for (n = 0; n < elems; n++) {
2396 if (tree[n].Freq != 0) {
2397 s->heap[++(s->heap_len)] = max_code = n;
2404 /* The pkzip format requires that at least one distance code exists,
2405 * and that at least one bit should be sent even if there is only one
2406 * possible code. So to avoid special checks later on we force at least
2407 * two codes of non zero frequency.
2409 while (s->heap_len < 2) {
2410 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2411 tree[node].Freq = 1;
2413 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2414 /* node is 0 or 1 so it does not have extra bits */
2416 desc->max_code = max_code;
2418 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2419 * establish sub-heaps of increasing lengths:
2421 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2423 /* Construct the Huffman tree by repeatedly combining the least two
2426 node = elems; /* next internal node of the tree */
2428 pqremove(s, tree, n); /* n = node of least frequency */
2429 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2431 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2432 s->heap[--(s->heap_max)] = m;
2434 /* Create a new node father of n and m */
2435 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2436 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2437 tree[n].Dad = tree[m].Dad = (ush)node;
2439 if (tree == s->bl_tree) {
2440 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2441 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2444 /* and insert the new node in the heap */
2445 s->heap[SMALLEST] = node++;
2446 pqdownheap(s, tree, SMALLEST);
2448 } while (s->heap_len >= 2);
2450 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2452 /* At this point, the fields freq and dad are set. We can now
2453 * generate the bit lengths.
2455 gen_bitlen(s, (tree_desc *)desc);
2457 /* The field len is now set, we can generate the bit codes */
2458 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2461 /* ===========================================================================
2462 * Scan a literal or distance tree to determine the frequencies of the codes
2463 * in the bit length tree.
2465 local void scan_tree (s, tree, max_code)
2467 ct_data *tree; /* the tree to be scanned */
2468 int max_code; /* and its largest code of non zero frequency */
2470 int n; /* iterates over all tree elements */
2471 int prevlen = -1; /* last emitted length */
2472 int curlen; /* length of current code */
2473 int nextlen = tree[0].Len; /* length of next code */
2474 int count = 0; /* repeat count of the current code */
2475 int max_count = 7; /* max repeat count */
2476 int min_count = 4; /* min repeat count */
2478 if (nextlen == 0) max_count = 138, min_count = 3;
2479 tree[max_code+1].Len = (ush)0xffff; /* guard */
2481 for (n = 0; n <= max_code; n++) {
2482 curlen = nextlen; nextlen = tree[n+1].Len;
2483 if (++count < max_count && curlen == nextlen) {
2485 } else if (count < min_count) {
2486 s->bl_tree[curlen].Freq += count;
2487 } else if (curlen != 0) {
2488 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2489 s->bl_tree[REP_3_6].Freq++;
2490 } else if (count <= 10) {
2491 s->bl_tree[REPZ_3_10].Freq++;
2493 s->bl_tree[REPZ_11_138].Freq++;
2495 count = 0; prevlen = curlen;
2497 max_count = 138, min_count = 3;
2498 } else if (curlen == nextlen) {
2499 max_count = 6, min_count = 3;
2501 max_count = 7, min_count = 4;
2506 /* ===========================================================================
2507 * Send a literal or distance tree in compressed form, using the codes in
2510 local void send_tree (s, tree, max_code)
2512 ct_data *tree; /* the tree to be scanned */
2513 int max_code; /* and its largest code of non zero frequency */
2515 int n; /* iterates over all tree elements */
2516 int prevlen = -1; /* last emitted length */
2517 int curlen; /* length of current code */
2518 int nextlen = tree[0].Len; /* length of next code */
2519 int count = 0; /* repeat count of the current code */
2520 int max_count = 7; /* max repeat count */
2521 int min_count = 4; /* min repeat count */
2523 /* tree[max_code+1].Len = -1; */ /* guard already set */
2524 if (nextlen == 0) max_count = 138, min_count = 3;
2526 for (n = 0; n <= max_code; n++) {
2527 curlen = nextlen; nextlen = tree[n+1].Len;
2528 if (++count < max_count && curlen == nextlen) {
2530 } else if (count < min_count) {
2531 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2533 } else if (curlen != 0) {
2534 if (curlen != prevlen) {
2535 send_code(s, curlen, s->bl_tree); count--;
2537 Assert(count >= 3 && count <= 6, " 3_6?");
2538 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2540 } else if (count <= 10) {
2541 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2544 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2546 count = 0; prevlen = curlen;
2548 max_count = 138, min_count = 3;
2549 } else if (curlen == nextlen) {
2550 max_count = 6, min_count = 3;
2552 max_count = 7, min_count = 4;
2557 /* ===========================================================================
2558 * Construct the Huffman tree for the bit lengths and return the index in
2559 * bl_order of the last bit length code to send.
2561 local int build_bl_tree(s)
2564 int max_blindex; /* index of last bit length code of non zero freq */
2566 /* Determine the bit length frequencies for literal and distance trees */
2567 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2568 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2570 /* Build the bit length tree: */
2571 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2572 /* opt_len now includes the length of the tree representations, except
2573 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2576 /* Determine the number of bit length codes to send. The pkzip format
2577 * requires that at least 4 bit length codes be sent. (appnote.txt says
2578 * 3 but the actual value used is 4.)
2580 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2581 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2583 /* Update opt_len to include the bit length tree and counts */
2584 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2585 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2586 s->opt_len, s->static_len));
2591 /* ===========================================================================
2592 * Send the header for a block using dynamic Huffman trees: the counts, the
2593 * lengths of the bit length codes, the literal tree and the distance tree.
2594 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2596 local void send_all_trees(s, lcodes, dcodes, blcodes)
2598 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2600 int rank; /* index in bl_order */
2602 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2603 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2605 Tracev((stderr, "\nbl counts: "));
2606 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2607 send_bits(s, dcodes-1, 5);
2608 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2609 for (rank = 0; rank < blcodes; rank++) {
2610 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2611 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2613 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2615 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2616 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2618 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2619 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2622 /* ===========================================================================
2623 * Send a stored block
2625 void _tr_stored_block(s, buf, stored_len, eof)
2627 charf *buf; /* input block */
2628 ulg stored_len; /* length of input block */
2629 int eof; /* true if this is the last block for a file */
2631 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2632 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
2633 s->compressed_len += (stored_len + 4) << 3;
2635 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2638 /* Send just the `stored block' type code without any length bytes or data.
2640 void _tr_stored_type_only(s)
2643 send_bits(s, (STORED_BLOCK << 1), 3);
2645 s->compressed_len = (s->compressed_len + 3) & ~7L;
2649 /* ===========================================================================
2650 * Send one empty static block to give enough lookahead for inflate.
2651 * This takes 10 bits, of which 7 may remain in the bit buffer.
2652 * The current inflate code requires 9 bits of lookahead. If the
2653 * last two codes for the previous block (real code plus EOB) were coded
2654 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
2655 * the last real code. In this case we send two empty static blocks instead
2656 * of one. (There are no problems if the previous block is stored or fixed.)
2657 * To simplify the code, we assume the worst case of last real code encoded
2663 send_bits(s, STATIC_TREES<<1, 3);
2664 send_code(s, END_BLOCK, static_ltree);
2665 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2667 /* Of the 10 bits for the empty block, we have already sent
2668 * (10 - bi_valid) bits. The lookahead for the last real code (before
2669 * the EOB of the previous block) was thus at least one plus the length
2670 * of the EOB plus what we have just sent of the empty static block.
2672 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
2673 send_bits(s, STATIC_TREES<<1, 3);
2674 send_code(s, END_BLOCK, static_ltree);
2675 s->compressed_len += 10L;
2678 s->last_eob_len = 7;
2681 /* ===========================================================================
2682 * Determine the best encoding for the current block: dynamic trees, static
2683 * trees or store, and output the encoded block to the zip file. This function
2684 * returns the total compressed length for the file so far.
2686 ulg _tr_flush_block(s, buf, stored_len, eof)
2688 charf *buf; /* input block, or NULL if too old */
2689 ulg stored_len; /* length of input block */
2690 int eof; /* true if this is the last block for a file */
2692 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2693 int max_blindex = 0; /* index of last bit length code of non zero freq */
2695 /* Build the Huffman trees unless a stored block is forced */
2698 /* Check if the file is ascii or binary */
2699 if (s->data_type == Z_UNKNOWN) set_data_type(s);
2701 /* Construct the literal and distance trees */
2702 build_tree(s, (tree_desc *)(&(s->l_desc)));
2703 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2706 build_tree(s, (tree_desc *)(&(s->d_desc)));
2707 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2709 /* At this point, opt_len and static_len are the total bit lengths of
2710 * the compressed block data, excluding the tree representations.
2713 /* Build the bit length tree for the above two trees, and get the index
2714 * in bl_order of the last bit length code to send.
2716 max_blindex = build_bl_tree(s);
2718 /* Determine the best encoding. Compute first the block length in bytes*/
2719 opt_lenb = (s->opt_len+3+7)>>3;
2720 static_lenb = (s->static_len+3+7)>>3;
2722 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2723 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2726 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2729 Assert(buf != (char*)0, "lost buf");
2730 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
2733 /* If compression failed and this is the first and last block,
2734 * and if the .zip file can be seeked (to rewrite the local header),
2735 * the whole file is transformed into a stored file:
2737 #ifdef STORED_FILE_OK
2738 # ifdef FORCE_STORED_FILE
2739 if (eof && s->compressed_len == 0L) { /* force stored file */
2741 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
2743 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2744 if (buf == (charf*)0) error ("block vanished");
2746 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
2747 s->compressed_len = stored_len << 3;
2750 #endif /* STORED_FILE_OK */
2753 if (buf != (char*)0) { /* force stored block */
2755 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2756 /* 4: two words for the lengths */
2758 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2759 * Otherwise we can't have processed more than WSIZE input bytes since
2760 * the last block flush, because compression would have been
2761 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2762 * transform a block into a stored block.
2764 _tr_stored_block(s, buf, stored_len, eof);
2767 } else if (static_lenb >= 0) { /* force static trees */
2769 } else if (static_lenb == opt_lenb) {
2771 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2772 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2773 s->compressed_len += 3 + s->static_len;
2775 send_bits(s, (DYN_TREES<<1)+eof, 3);
2776 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2778 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2779 s->compressed_len += 3 + s->opt_len;
2781 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2786 s->compressed_len += 7; /* align on byte boundary */
2788 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2789 s->compressed_len-7*eof));
2791 return s->compressed_len >> 3;
2794 /* ===========================================================================
2795 * Save the match info and tally the frequency counts. Return true if
2796 * the current block must be flushed.
2798 int _tr_tally (s, dist, lc)
2800 unsigned dist; /* distance of matched string */
2801 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2803 s->d_buf[s->last_lit] = (ush)dist;
2804 s->l_buf[s->last_lit++] = (uch)lc;
2806 /* lc is the unmatched char */
2807 s->dyn_ltree[lc].Freq++;
2810 /* Here, lc is the match length - MIN_MATCH */
2811 dist--; /* dist = match distance - 1 */
2812 Assert((ush)dist < (ush)MAX_DIST(s) &&
2813 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2814 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
2816 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2817 s->dyn_dtree[d_code(dist)].Freq++;
2820 /* Try to guess if it is profitable to stop the current block here */
2821 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2822 /* Compute an upper bound for the compressed length */
2823 ulg out_length = (ulg)s->last_lit*8L;
2824 ulg in_length = (ulg)((long)s->strstart - s->block_start);
2826 for (dcode = 0; dcode < D_CODES; dcode++) {
2827 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2828 (5L+extra_dbits[dcode]);
2831 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2832 s->last_lit, in_length, out_length,
2833 100L - out_length*100L/in_length));
2834 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2836 return (s->last_lit == s->lit_bufsize-1);
2837 /* We avoid equality with lit_bufsize because of wraparound at 64K
2838 * on 16 bit machines and because stored blocks are restricted to
2843 /* ===========================================================================
2844 * Send the block data compressed using the given Huffman trees
2846 local void compress_block(s, ltree, dtree)
2848 ct_data *ltree; /* literal tree */
2849 ct_data *dtree; /* distance tree */
2851 unsigned dist; /* distance of matched string */
2852 int lc; /* match length or unmatched char (if dist == 0) */
2853 unsigned lx = 0; /* running index in l_buf */
2854 unsigned code; /* the code to send */
2855 int extra; /* number of extra bits to send */
2857 if (s->last_lit != 0) do {
2858 dist = s->d_buf[lx];
2859 lc = s->l_buf[lx++];
2861 send_code(s, lc, ltree); /* send a literal byte */
2862 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2864 /* Here, lc is the match length - MIN_MATCH */
2865 code = length_code[lc];
2866 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2867 extra = extra_lbits[code];
2869 lc -= base_length[code];
2870 send_bits(s, lc, extra); /* send the extra length bits */
2872 dist--; /* dist is now the match distance - 1 */
2873 code = d_code(dist);
2874 Assert (code < D_CODES, "bad d_code");
2876 send_code(s, code, dtree); /* send the distance code */
2877 extra = extra_dbits[code];
2879 dist -= base_dist[code];
2880 send_bits(s, dist, extra); /* send the extra distance bits */
2882 } /* literal or match pair ? */
2884 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2885 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2887 } while (lx < s->last_lit);
2889 send_code(s, END_BLOCK, ltree);
2890 s->last_eob_len = ltree[END_BLOCK].Len;
2893 /* ===========================================================================
2894 * Set the data type to ASCII or BINARY, using a crude approximation:
2895 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2896 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2897 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2899 local void set_data_type(s)
2903 unsigned ascii_freq = 0;
2904 unsigned bin_freq = 0;
2905 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2906 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2907 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2908 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
2911 /* ===========================================================================
2912 * Reverse the first len bits of a code, using straightforward code (a faster
2913 * method would use a table)
2914 * IN assertion: 1 <= len <= 15
2916 local unsigned bi_reverse(code, len)
2917 unsigned code; /* the value to invert */
2918 int len; /* its bit length */
2923 code >>= 1, res <<= 1;
2924 } while (--len > 0);
2928 /* ===========================================================================
2929 * Flush the bit buffer, keeping at most 7 bits in it.
2931 local void bi_flush(s)
2934 if (s->bi_valid == 16) {
2935 put_short(s, s->bi_buf);
2938 } else if (s->bi_valid >= 8) {
2939 put_byte(s, (Byte)s->bi_buf);
2945 /* ===========================================================================
2946 * Flush the bit buffer and align the output on a byte boundary
2948 local void bi_windup(s)
2951 if (s->bi_valid > 8) {
2952 put_short(s, s->bi_buf);
2953 } else if (s->bi_valid > 0) {
2954 put_byte(s, (Byte)s->bi_buf);
2959 s->bits_sent = (s->bits_sent+7) & ~7;
2963 /* ===========================================================================
2964 * Copy a stored block, storing first the length and its
2965 * one's complement if requested.
2967 local void copy_block(s, buf, len, header)
2969 charf *buf; /* the input data */
2970 unsigned len; /* its length */
2971 int header; /* true if block header must be written */
2973 bi_windup(s); /* align on byte boundary */
2974 s->last_eob_len = 8; /* enough lookahead for inflate */
2977 put_short(s, (ush)len);
2978 put_short(s, (ush)~len);
2980 s->bits_sent += 2*16;
2984 s->bits_sent += (ulg)len<<3;
2986 /* bundle up the put_byte(s, *buf++) calls */
2987 zmemcpy(&s->pending_buf[s->pending], buf, len);
2993 /* inflate.c -- zlib interface to inflate modules
2994 * Copyright (C) 1995-1996 Mark Adler
2995 * For conditions of distribution and use, see copyright notice in zlib.h
2998 /* #include "zutil.h" */
3000 /* +++ infblock.h */
3001 /* infblock.h -- header to use infblock.c
3002 * Copyright (C) 1995-1996 Mark Adler
3003 * For conditions of distribution and use, see copyright notice in zlib.h
3006 /* WARNING: this file should *not* be used by applications. It is
3007 part of the implementation of the compression library and is
3008 subject to change. Applications should only use zlib.h.
3011 struct inflate_blocks_state;
3012 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3014 extern inflate_blocks_statef * inflate_blocks_new OF((
3016 check_func c, /* check function */
3017 uInt w)); /* window size */
3019 extern int inflate_blocks OF((
3020 inflate_blocks_statef *,
3022 int)); /* initial return code */
3024 extern void inflate_blocks_reset OF((
3025 inflate_blocks_statef *,
3027 uLongf *)); /* check value on output */
3029 extern int inflate_blocks_free OF((
3030 inflate_blocks_statef *,
3032 uLongf *)); /* check value on output */
3034 extern void inflate_set_dictionary OF((
3035 inflate_blocks_statef *s,
3036 const Bytef *d, /* dictionary */
3037 uInt n)); /* dictionary length */
3039 extern int inflate_addhistory OF((
3040 inflate_blocks_statef *,
3043 extern int inflate_packet_flush OF((
3044 inflate_blocks_statef *));
3045 /* --- infblock.h */
3047 #ifndef NO_DUMMY_DECL
3048 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3051 /* inflate private state */
3052 struct internal_state {
3056 METHOD, /* waiting for method byte */
3057 FLAG, /* waiting for flag byte */
3058 DICT4, /* four dictionary check bytes to go */
3059 DICT3, /* three dictionary check bytes to go */
3060 DICT2, /* two dictionary check bytes to go */
3061 DICT1, /* one dictionary check byte to go */
3062 DICT0, /* waiting for inflateSetDictionary */
3063 BLOCKS, /* decompressing blocks */
3064 CHECK4, /* four check bytes to go */
3065 CHECK3, /* three check bytes to go */
3066 CHECK2, /* two check bytes to go */
3067 CHECK1, /* one check byte to go */
3068 DONE, /* finished check, done */
3069 BAD} /* got an error--stay here */
3070 mode; /* current inflate mode */
3072 /* mode dependent information */
3074 uInt method; /* if FLAGS, method byte */
3076 uLong was; /* computed check value */
3077 uLong need; /* stream check value */
3078 } check; /* if CHECK, check values to compare */
3079 uInt marker; /* if BAD, inflateSync's marker bytes count */
3080 } sub; /* submode */
3082 /* mode independent information */
3083 int nowrap; /* flag for no wrapper */
3084 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3085 inflate_blocks_statef
3086 *blocks; /* current inflate_blocks state */
3096 if (z == Z_NULL || z->state == Z_NULL)
3097 return Z_STREAM_ERROR;
3098 z->total_in = z->total_out = 0;
3100 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3101 inflate_blocks_reset(z->state->blocks, z, &c);
3102 Trace((stderr, "inflate: reset\n"));
3112 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3113 return Z_STREAM_ERROR;
3114 if (z->state->blocks != Z_NULL)
3115 inflate_blocks_free(z->state->blocks, z, &c);
3118 Trace((stderr, "inflate: end\n"));
3123 int inflateInit2_(z, w, version, stream_size)
3126 const char *version;
3129 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3130 stream_size != sizeof(z_stream))
3131 return Z_VERSION_ERROR;
3133 /* initialize state */
3135 return Z_STREAM_ERROR;
3138 if (z->zalloc == Z_NULL)
3140 z->zalloc = zcalloc;
3141 z->opaque = (voidpf)0;
3143 if (z->zfree == Z_NULL) z->zfree = zcfree;
3145 if ((z->state = (struct internal_state FAR *)
3146 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3148 z->state->blocks = Z_NULL;
3150 /* handle undocumented nowrap option (no zlib header or check) */
3151 z->state->nowrap = 0;
3155 z->state->nowrap = 1;
3158 /* set window size */
3159 if (w < 8 || w > 15)
3162 return Z_STREAM_ERROR;
3164 z->state->wbits = (uInt)w;
3166 /* create inflate_blocks state */
3167 if ((z->state->blocks =
3168 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3174 Trace((stderr, "inflate: allocated\n"));
3182 int inflateInit_(z, version, stream_size)
3184 const char *version;
3187 return inflateInit2_(z, DEF_WBITS, version, stream_size);
3191 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3192 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3201 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0)
3202 return Z_STREAM_ERROR;
3204 while (1) switch (z->state->mode)
3208 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3210 z->state->mode = BAD;
3211 z->msg = (char*)"unknown compression method";
3212 z->state->sub.marker = 5; /* can't try inflateSync */
3215 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3217 z->state->mode = BAD;
3218 z->msg = (char*)"invalid window size";
3219 z->state->sub.marker = 5; /* can't try inflateSync */
3222 z->state->mode = FLAG;
3226 if (((z->state->sub.method << 8) + b) % 31)
3228 z->state->mode = BAD;
3229 z->msg = (char*)"incorrect header check";
3230 z->state->sub.marker = 5; /* can't try inflateSync */
3233 Trace((stderr, "inflate: zlib header ok\n"));
3234 if (!(b & PRESET_DICT))
3236 z->state->mode = BLOCKS;
3239 z->state->mode = DICT4;
3242 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3243 z->state->mode = DICT3;
3246 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3247 z->state->mode = DICT2;
3250 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3251 z->state->mode = DICT1;
3254 z->state->sub.check.need += (uLong)NEXTBYTE;
3255 z->adler = z->state->sub.check.need;
3256 z->state->mode = DICT0;
3259 z->state->mode = BAD;
3260 z->msg = (char*)"need dictionary";
3261 z->state->sub.marker = 0; /* can try inflateSync */
3262 return Z_STREAM_ERROR;
3264 r = inflate_blocks(z->state->blocks, z, r);
3265 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3266 r = inflate_packet_flush(z->state->blocks);
3267 if (r == Z_DATA_ERROR)
3269 z->state->mode = BAD;
3270 z->state->sub.marker = 0; /* can try inflateSync */
3273 if (r != Z_STREAM_END)
3276 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3277 if (z->state->nowrap)
3279 z->state->mode = DONE;
3282 z->state->mode = CHECK4;
3285 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3286 z->state->mode = CHECK3;
3289 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3290 z->state->mode = CHECK2;
3293 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3294 z->state->mode = CHECK1;
3297 z->state->sub.check.need += (uLong)NEXTBYTE;
3299 if (z->state->sub.check.was != z->state->sub.check.need)
3301 z->state->mode = BAD;
3302 z->msg = (char*)"incorrect data check";
3303 z->state->sub.marker = 5; /* can't try inflateSync */
3306 Trace((stderr, "inflate: zlib check ok\n"));
3307 z->state->mode = DONE;
3309 return Z_STREAM_END;
3311 return Z_DATA_ERROR;
3313 return Z_STREAM_ERROR;
3317 if (f != Z_PACKET_FLUSH)
3319 z->state->mode = BAD;
3320 z->msg = (char *)"need more for packet flush";
3321 z->state->sub.marker = 0; /* can try inflateSync */
3322 return Z_DATA_ERROR;
3326 int inflateSetDictionary(z, dictionary, dictLength)
3328 const Bytef *dictionary;
3331 uInt length = dictLength;
3333 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3334 return Z_STREAM_ERROR;
3336 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3339 if (length >= ((uInt)1<<z->state->wbits))
3341 length = (1<<z->state->wbits)-1;
3342 dictionary += dictLength - length;
3344 inflate_set_dictionary(z->state->blocks, dictionary, length);
3345 z->state->mode = BLOCKS;
3350 * This subroutine adds the data at next_in/avail_in to the output history
3351 * without performing any output. The output buffer must be "caught up";
3352 * i.e. no pending output (hence s->read equals s->write), and the state must
3353 * be BLOCKS (i.e. we should be willing to see the start of a series of
3354 * BLOCKS). On exit, the output will also be caught up, and the checksum
3355 * will have been updated if need be.
3358 int inflateIncomp(z)
3361 if (z->state->mode != BLOCKS)
3362 return Z_DATA_ERROR;
3363 return inflate_addhistory(z->state->blocks, z);
3370 uInt n; /* number of bytes to look at */
3371 Bytef *p; /* pointer to bytes */
3372 uInt m; /* number of marker bytes found in a row */
3373 uLong r, w; /* temporaries to save total_in and total_out */
3376 if (z == Z_NULL || z->state == Z_NULL)
3377 return Z_STREAM_ERROR;
3378 if (z->state->mode != BAD)
3380 z->state->mode = BAD;
3381 z->state->sub.marker = 0;
3383 if ((n = z->avail_in) == 0)
3386 m = z->state->sub.marker;
3391 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3401 z->total_in += p - z->next_in;
3404 z->state->sub.marker = m;
3406 /* return no joy or set up to restart on a new block */
3408 return Z_DATA_ERROR;
3409 r = z->total_in; w = z->total_out;
3411 z->total_in = r; z->total_out = w;
3412 z->state->mode = BLOCKS;
3420 /* +++ infblock.c */
3421 /* infblock.c -- interpret and process block types to last block
3422 * Copyright (C) 1995-1996 Mark Adler
3423 * For conditions of distribution and use, see copyright notice in zlib.h
3426 /* #include "zutil.h" */
3427 /* #include "infblock.h" */
3429 /* +++ inftrees.h */
3430 /* inftrees.h -- header to use inftrees.c
3431 * Copyright (C) 1995-1996 Mark Adler
3432 * For conditions of distribution and use, see copyright notice in zlib.h
3435 /* WARNING: this file should *not* be used by applications. It is
3436 part of the implementation of the compression library and is
3437 subject to change. Applications should only use zlib.h.
3440 /* Huffman code lookup table entry--this entry is four bytes for machines
3441 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3443 typedef struct inflate_huft_s FAR inflate_huft;
3445 struct inflate_huft_s {
3448 Byte Exop; /* number of extra bits or operation */
3449 Byte Bits; /* number of bits in this code or subcode */
3451 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
3452 } word; /* 16-bit, 8 bytes for 32-bit machines) */
3454 uInt Base; /* literal, length base, or distance base */
3455 inflate_huft *Next; /* pointer to next level of table */
3460 extern uInt inflate_hufts;
3463 extern int inflate_trees_bits OF((
3464 uIntf *, /* 19 code lengths */
3465 uIntf *, /* bits tree desired/actual depth */
3466 inflate_huft * FAR *, /* bits tree result */
3467 z_streamp )); /* for zalloc, zfree functions */
3469 extern int inflate_trees_dynamic OF((
3470 uInt, /* number of literal/length codes */
3471 uInt, /* number of distance codes */
3472 uIntf *, /* that many (total) code lengths */
3473 uIntf *, /* literal desired/actual bit depth */
3474 uIntf *, /* distance desired/actual bit depth */
3475 inflate_huft * FAR *, /* literal/length tree result */
3476 inflate_huft * FAR *, /* distance tree result */
3477 z_streamp )); /* for zalloc, zfree functions */
3479 extern int inflate_trees_fixed OF((
3480 uIntf *, /* literal desired/actual bit depth */
3481 uIntf *, /* distance desired/actual bit depth */
3482 inflate_huft * FAR *, /* literal/length tree result */
3483 inflate_huft * FAR *)); /* distance tree result */
3485 extern int inflate_trees_free OF((
3486 inflate_huft *, /* tables to free */
3487 z_streamp )); /* for zfree function */
3489 /* --- inftrees.h */
3491 /* +++ infcodes.h */
3492 /* infcodes.h -- header to use infcodes.c
3493 * Copyright (C) 1995-1996 Mark Adler
3494 * For conditions of distribution and use, see copyright notice in zlib.h
3497 /* WARNING: this file should *not* be used by applications. It is
3498 part of the implementation of the compression library and is
3499 subject to change. Applications should only use zlib.h.
3502 struct inflate_codes_state;
3503 typedef struct inflate_codes_state FAR inflate_codes_statef;
3505 extern inflate_codes_statef *inflate_codes_new OF((
3507 inflate_huft *, inflate_huft *,
3510 extern int inflate_codes OF((
3511 inflate_blocks_statef *,
3515 extern void inflate_codes_free OF((
3516 inflate_codes_statef *,
3519 /* --- infcodes.h */
3522 /* infutil.h -- types and macros common to blocks and codes
3523 * Copyright (C) 1995-1996 Mark Adler
3524 * For conditions of distribution and use, see copyright notice in zlib.h
3527 /* WARNING: this file should *not* be used by applications. It is
3528 part of the implementation of the compression library and is
3529 subject to change. Applications should only use zlib.h.
3536 TYPE, /* get type bits (3, including end bit) */
3537 LENS, /* get lengths for stored */
3538 STORED, /* processing stored block */
3539 TABLE, /* get table lengths */
3540 BTREE, /* get bit lengths tree for a dynamic block */
3541 DTREE, /* get length, distance trees for a dynamic block */
3542 CODES, /* processing fixed or dynamic block */
3543 DRY, /* output remaining window bytes */
3544 DONEB, /* finished last block, done */
3545 BADB} /* got a data error--stuck here */
3548 /* inflate blocks semi-private state */
3549 struct inflate_blocks_state {
3552 inflate_block_mode mode; /* current inflate_block mode */
3554 /* mode dependent information */
3556 uInt left; /* if STORED, bytes left to copy */
3558 uInt table; /* table lengths (14 bits) */
3559 uInt index; /* index into blens (or border) */
3560 uIntf *blens; /* bit lengths of codes */
3561 uInt bb; /* bit length tree depth */
3562 inflate_huft *tb; /* bit length decoding tree */
3563 } trees; /* if DTREE, decoding info for trees */
3566 inflate_huft *td; /* trees to free */
3567 inflate_codes_statef
3569 } decode; /* if CODES, current state */
3570 } sub; /* submode */
3571 uInt last; /* true if this block is the last block */
3573 /* mode independent information */
3574 uInt bitk; /* bits in bit buffer */
3575 uLong bitb; /* bit buffer */
3576 Bytef *window; /* sliding window */
3577 Bytef *end; /* one byte after sliding window */
3578 Bytef *read; /* window read pointer */
3579 Bytef *write; /* window write pointer */
3580 check_func checkfn; /* check function */
3581 uLong check; /* check on output */
3586 /* defines for inflate input/output */
3587 /* update pointers and return */
3588 #define UPDBITS {s->bitb=b;s->bitk=k;}
3589 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3590 #define UPDOUT {s->write=q;}
3591 #define UPDATE {UPDBITS UPDIN UPDOUT}
3592 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3593 /* get bytes and bits */
3594 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3595 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3596 #define NEXTBYTE (n--,*p++)
3597 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3598 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3600 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3601 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3602 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3603 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3604 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;}
3605 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3606 /* load local pointers */
3607 #define LOAD {LOADIN LOADOUT}
3609 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3610 extern uInt inflate_mask[17];
3612 /* copy as much as possible from the sliding window to the output area */
3613 extern int inflate_flush OF((
3614 inflate_blocks_statef *,
3618 #ifndef NO_DUMMY_DECL
3619 struct internal_state {int dummy;}; /* for buggy compilers */
3625 #ifndef NO_DUMMY_DECL
3626 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3629 /* Table for deflate from PKZIP's appnote.txt. */
3630 local const uInt border[] = { /* Order of the bit length code lengths */
3631 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3634 Notes beyond the 1.93a appnote.txt:
3636 1. Distance pointers never point before the beginning of the output
3638 2. Distance pointers can point back across blocks, up to 32k away.
3639 3. There is an implied maximum of 7 bits for the bit length table and
3640 15 bits for the actual data.
3641 4. If only one code exists, then it is encoded using one bit. (Zero
3642 would be more efficient, but perhaps a little confusing.) If two
3643 codes exist, they are coded using one bit each (0 and 1).
3644 5. There is no way of sending zero distance codes--a dummy must be
3645 sent if there are none. (History: a pre 2.0 version of PKZIP would
3646 store blocks with no distance codes, but this was discovered to be
3647 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3648 zero distance codes, which is sent as one code of zero bits in
3650 6. There are up to 286 literal/length codes. Code 256 represents the
3651 end-of-block. Note however that the static length tree defines
3652 288 codes just to fill out the Huffman codes. Codes 286 and 287
3653 cannot be used though, since there is no length base or extra bits
3654 defined for them. Similarily, there are up to 30 distance codes.
3655 However, static trees define 32 codes (all 5 bits) to fill out the
3656 Huffman codes, but the last two had better not show up in the data.
3657 7. Unzip can check dynamic Huffman blocks for complete code sets.
3658 The exception is that a single code would not be complete (see #4).
3659 8. The five bits following the block type is really the number of
3660 literal codes sent minus 257.
3661 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3662 (1+6+6). Therefore, to output three times the length, you output
3663 three codes (1+1+1), whereas to output four times the same length,
3664 you only need two codes (1+3). Hmm.
3665 10. In the tree reconstruction algorithm, Code = Code + Increment
3666 only if BitLength(i) is not zero. (Pretty obvious.)
3667 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3668 12. Note: length code 284 can represent 227-258, but length code 285
3669 really is 258. The last length deserves its own, short code
3670 since it gets used a lot in very redundant files. The length
3671 258 is special since 258 - 3 (the min match length) is 255.
3672 13. The literal/length and distance code bit lengths are read as a
3673 single stream of lengths. It is possible (and advantageous) for
3674 a repeat code (16, 17, or 18) to go across the boundary between
3675 the two sets of lengths.
3679 void inflate_blocks_reset(s, z, c)
3680 inflate_blocks_statef *s;
3684 if (s->checkfn != Z_NULL)
3686 if (s->mode == BTREE || s->mode == DTREE)
3687 ZFREE(z, s->sub.trees.blens);
3688 if (s->mode == CODES)
3690 inflate_codes_free(s->sub.decode.codes, z);
3691 inflate_trees_free(s->sub.decode.td, z);
3692 inflate_trees_free(s->sub.decode.tl, z);
3697 s->read = s->write = s->window;
3698 if (s->checkfn != Z_NULL)
3699 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
3700 Trace((stderr, "inflate: blocks reset\n"));
3704 inflate_blocks_statef *inflate_blocks_new(z, c, w)
3709 inflate_blocks_statef *s;
3711 if ((s = (inflate_blocks_statef *)ZALLOC
3712 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3714 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3719 s->end = s->window + w;
3722 Trace((stderr, "inflate: blocks allocated\n"));
3723 inflate_blocks_reset(s, z, &s->check);
3729 extern uInt inflate_hufts;
3731 int inflate_blocks(s, z, r)
3732 inflate_blocks_statef *s;
3736 uInt t; /* temporary storage */
3737 uLong b; /* bit buffer */
3738 uInt k; /* bits in bit buffer */
3739 Bytef *p; /* input data pointer */
3740 uInt n; /* bytes available there */
3741 Bytef *q; /* output window write pointer */
3742 uInt m; /* bytes to end of window or read pointer */
3744 /* copy input/output information to locals (UPDATE macro restores) */
3747 /* process input based on current state */
3748 while (1) switch (s->mode)
3756 case 0: /* stored */
3757 Trace((stderr, "inflate: stored block%s\n",
3758 s->last ? " (last)" : ""));
3760 t = k & 7; /* go to byte boundary */
3762 s->mode = LENS; /* get length of stored block */
3765 Trace((stderr, "inflate: fixed codes block%s\n",
3766 s->last ? " (last)" : ""));
3769 inflate_huft *tl, *td;
3771 inflate_trees_fixed(&bl, &bd, &tl, &td);
3772 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3773 if (s->sub.decode.codes == Z_NULL)
3778 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3779 s->sub.decode.td = Z_NULL;
3784 case 2: /* dynamic */
3785 Trace((stderr, "inflate: dynamic codes block%s\n",
3786 s->last ? " (last)" : ""));
3790 case 3: /* illegal */
3793 z->msg = (char*)"invalid block type";
3800 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
3803 z->msg = (char*)"invalid stored block lengths";
3807 s->sub.left = (uInt)b & 0xffff;
3808 b = k = 0; /* dump bits */
3809 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3810 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
3822 if ((s->sub.left -= t) != 0)
3824 Tracev((stderr, "inflate: stored end, %lu total out\n",
3825 z->total_out + (q >= s->read ? q - s->read :
3826 (s->end - s->read) + (q - s->window))));
3827 s->mode = s->last ? DRY : TYPE;
3831 s->sub.trees.table = t = (uInt)b & 0x3fff;
3832 #ifndef PKZIP_BUG_WORKAROUND
3833 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3836 z->msg = (char*)"too many length or distance symbols";
3841 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3844 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3850 s->sub.trees.index = 0;
3851 Tracev((stderr, "inflate: table sizes ok\n"));
3854 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3857 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3860 while (s->sub.trees.index < 19)
3861 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3862 s->sub.trees.bb = 7;
3863 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3864 &s->sub.trees.tb, z);
3868 if (r == Z_DATA_ERROR) {
3869 ZFREE(z, s->sub.trees.blens);
3874 s->sub.trees.index = 0;
3875 Tracev((stderr, "inflate: bits tree ok\n"));
3878 while (t = s->sub.trees.table,
3879 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3884 t = s->sub.trees.bb;
3886 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3887 t = h->word.what.Bits;
3892 s->sub.trees.blens[s->sub.trees.index++] = c;
3894 else /* c == 16..18 */
3896 i = c == 18 ? 7 : c - 14;
3897 j = c == 18 ? 11 : 3;
3900 j += (uInt)b & inflate_mask[i];
3902 i = s->sub.trees.index;
3903 t = s->sub.trees.table;
3904 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3907 inflate_trees_free(s->sub.trees.tb, z);
3908 ZFREE(z, s->sub.trees.blens);
3910 z->msg = (char*)"invalid bit length repeat";
3914 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3916 s->sub.trees.blens[i++] = c;
3918 s->sub.trees.index = i;
3921 inflate_trees_free(s->sub.trees.tb, z);
3922 s->sub.trees.tb = Z_NULL;
3925 inflate_huft *tl, *td;
3926 inflate_codes_statef *c;
3928 bl = 9; /* must be <= 9 for lookahead assumptions */
3929 bd = 6; /* must be <= 9 for lookahead assumptions */
3930 t = s->sub.trees.table;
3934 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3935 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3938 if (t == (uInt)Z_DATA_ERROR) {
3939 ZFREE(z, s->sub.trees.blens);
3945 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n",
3946 inflate_hufts, sizeof(inflate_huft)));
3947 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3949 inflate_trees_free(td, z);
3950 inflate_trees_free(tl, z);
3955 * this ZFREE must occur *BEFORE* we mess with sub.decode, because
3956 * sub.trees is union'd with sub.decode.
3958 ZFREE(z, s->sub.trees.blens);
3959 s->sub.decode.codes = c;
3960 s->sub.decode.tl = tl;
3961 s->sub.decode.td = td;
3966 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3967 return inflate_flush(s, z, r);
3969 inflate_codes_free(s->sub.decode.codes, z);
3970 inflate_trees_free(s->sub.decode.td, z);
3971 inflate_trees_free(s->sub.decode.tl, z);
3973 Tracev((stderr, "inflate: codes end, %lu total out\n",
3974 z->total_out + (q >= s->read ? q - s->read :
3975 (s->end - s->read) + (q - s->window))));
3981 if (k > 7) /* return unused byte, if any */
3983 Assert(k < 16, "inflate_codes grabbed too many bytes")
3986 p--; /* can always return one */
3991 if (s->read != s->write)
4007 int inflate_blocks_free(s, z, c)
4008 inflate_blocks_statef *s;
4012 inflate_blocks_reset(s, z, c);
4013 ZFREE(z, s->window);
4015 Trace((stderr, "inflate: blocks freed\n"));
4020 void inflate_set_dictionary(s, d, n)
4021 inflate_blocks_statef *s;
4025 zmemcpy((charf *)s->window, d, n);
4026 s->read = s->write = s->window + n;
4030 * This subroutine adds the data at next_in/avail_in to the output history
4031 * without performing any output. The output buffer must be "caught up";
4032 * i.e. no pending output (hence s->read equals s->write), and the state must
4033 * be BLOCKS (i.e. we should be willing to see the start of a series of
4034 * BLOCKS). On exit, the output will also be caught up, and the checksum
4035 * will have been updated if need be.
4037 int inflate_addhistory(s, z)
4038 inflate_blocks_statef *s;
4041 uLong b; /* bit buffer */ /* NOT USED HERE */
4042 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
4043 uInt t; /* temporary storage */
4044 Bytef *p; /* input data pointer */
4045 uInt n; /* bytes available there */
4046 Bytef *q; /* output window write pointer */
4047 uInt m; /* bytes to end of window or read pointer */
4049 if (s->read != s->write)
4050 return Z_STREAM_ERROR;
4051 if (s->mode != TYPE)
4052 return Z_DATA_ERROR;
4054 /* we're ready to rock */
4056 /* while there is input ready, copy to output buffer, moving
4057 * pointers as needed.
4060 t = n; /* how many to do */
4061 /* is there room until end of buffer? */
4063 /* update check information */
4064 if (s->checkfn != Z_NULL)
4065 s->check = (*s->checkfn)(s->check, q, t);
4071 s->read = q; /* drag read pointer forward */
4072 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */
4074 s->read = q = s->window;
4084 * At the end of a Deflate-compressed PPP packet, we expect to have seen
4085 * a `stored' block type value but not the (zero) length bytes.
4087 int inflate_packet_flush(s)
4088 inflate_blocks_statef *s;
4090 if (s->mode != LENS)
4091 return Z_DATA_ERROR;
4095 /* --- infblock.c */
4097 /* +++ inftrees.c */
4098 /* inftrees.c -- generate Huffman trees for efficient decoding
4099 * Copyright (C) 1995-1996 Mark Adler
4100 * For conditions of distribution and use, see copyright notice in zlib.h
4103 /* #include "zutil.h" */
4104 /* #include "inftrees.h" */
4106 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler ";
4108 If you use the zlib library in a product, an acknowledgment is welcome
4109 in the documentation of your product. If for some reason you cannot
4110 include such an acknowledgment, I would appreciate that you keep this
4111 copyright string in the executable of your product.
4114 #ifndef NO_DUMMY_DECL
4115 struct internal_state {int dummy;}; /* for buggy compilers */
4118 /* simplify the use of the inflate_huft type with some defines */
4119 #define base more.Base
4120 #define next more.Next
4121 #define exop word.what.Exop
4122 #define bits word.what.Bits
4125 local int huft_build OF((
4126 uIntf *, /* code lengths in bits */
4127 uInt, /* number of codes */
4128 uInt, /* number of "simple" codes */
4129 const uIntf *, /* list of base values for non-simple codes */
4130 const uIntf *, /* list of extra bits for non-simple codes */
4131 inflate_huft * FAR*,/* result: starting table */
4132 uIntf *, /* maximum lookup bits (returns actual) */
4133 z_streamp )); /* for zalloc function */
4135 local voidpf falloc OF((
4136 voidpf, /* opaque pointer (not used) */
4137 uInt, /* number of items */
4138 uInt)); /* size of item */
4140 /* Tables for deflate from PKZIP's appnote.txt. */
4141 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4142 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4143 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4144 /* see note #13 above about 258 */
4145 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4146 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4147 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4148 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4149 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4150 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4151 8193, 12289, 16385, 24577};
4152 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4153 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4154 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4158 Huffman code decoding is performed using a multi-level table lookup.
4159 The fastest way to decode is to simply build a lookup table whose
4160 size is determined by the longest code. However, the time it takes
4161 to build this table can also be a factor if the data being decoded
4162 is not very long. The most common codes are necessarily the
4163 shortest codes, so those codes dominate the decoding time, and hence
4164 the speed. The idea is you can have a shorter table that decodes the
4165 shorter, more probable codes, and then point to subsidiary tables for
4166 the longer codes. The time it costs to decode the longer codes is
4167 then traded against the time it takes to make longer tables.
4169 This results of this trade are in the variables lbits and dbits
4170 below. lbits is the number of bits the first level table for literal/
4171 length codes can decode in one step, and dbits is the same thing for
4172 the distance codes. Subsequent tables are also less than or equal to
4173 those sizes. These values may be adjusted either when all of the
4174 codes are shorter than that, in which case the longest code length in
4175 bits is used, or when the shortest code is *longer* than the requested
4176 table size, in which case the length of the shortest code in bits is
4179 There are two different values for the two tables, since they code a
4180 different number of possibilities each. The literal/length table
4181 codes 286 possible values, or in a flat code, a little over eight
4182 bits. The distance table codes 30 possible values, or a little less
4183 than five bits, flat. The optimum values for speed end up being
4184 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4185 The optimum values may differ though from machine to machine, and
4186 possibly even between compilers. Your mileage may vary.
4190 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4191 #define BMAX 15 /* maximum bit length of any code */
4192 #define N_MAX 288 /* maximum number of codes in any set */
4198 local int huft_build(b, n, s, d, e, t, m, zs)
4199 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
4200 uInt n; /* number of codes (assumed <= N_MAX) */
4201 uInt s; /* number of simple-valued codes (0..s-1) */
4202 const uIntf *d; /* list of base values for non-simple codes */
4203 const uIntf *e; /* list of extra bits for non-simple codes */
4204 inflate_huft * FAR *t; /* result: starting table */
4205 uIntf *m; /* maximum lookup bits, returns actual */
4206 z_streamp zs; /* for zalloc function */
4207 /* Given a list of code lengths and a maximum table size, make a set of
4208 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
4209 if the given code set is incomplete (the tables are still built in this
4210 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of
4211 lengths), or Z_MEM_ERROR if not enough memory. */
4214 uInt a; /* counter for codes of length k */
4215 uInt c[BMAX+1]; /* bit length count table */
4216 uInt f; /* i repeats in table every f entries */
4217 int g; /* maximum code length */
4218 int h; /* table level */
4219 uInt i; /* counter, current code */
4220 uInt j; /* counter */
4221 int k; /* number of bits in current code */
4222 int l; /* bits per table (returned in m) */
4223 uIntf *p; /* pointer into c[], b[], or v[] */
4224 inflate_huft *q; /* points to current table */
4225 struct inflate_huft_s r; /* table entry for structure assignment */
4226 inflate_huft *u[BMAX]; /* table stack */
4227 uInt v[N_MAX]; /* values in order of bit length */
4228 int w; /* bits before this table == (l * h) */
4229 uInt x[BMAX+1]; /* bit offsets, then code stack */
4230 uIntf *xp; /* pointer into x */
4231 int y; /* number of dummy codes added */
4232 uInt z; /* number of entries in current table */
4235 /* Generate counts for each bit length */
4237 #define C0 *p++ = 0;
4238 #define C2 C0 C0 C0 C0
4239 #define C4 C2 C2 C2 C2
4240 C4 /* clear c[]--assume BMAX+1 is 16 */
4243 c[*p++]++; /* assume all entries <= BMAX */
4245 if (c[0] == n) /* null input--all zero length codes */
4247 *t = (inflate_huft *)Z_NULL;
4253 /* Find minimum and maximum length, bound *m by those */
4255 for (j = 1; j <= BMAX; j++)
4258 k = j; /* minimum code length */
4261 for (i = BMAX; i; i--)
4264 g = i; /* maximum code length */
4270 /* Adjust last length count to fill out codes, if needed */
4271 for (y = 1 << j; j < i; j++, y <<= 1)
4272 if ((y -= c[j]) < 0)
4273 return Z_DATA_ERROR;
4274 if ((y -= c[i]) < 0)
4275 return Z_DATA_ERROR;
4279 /* Generate starting offsets into the value table for each length */
4281 p = c + 1; xp = x + 2;
4282 while (--i) { /* note that i == g from above */
4283 *xp++ = (j += *p++);
4287 /* Make a table of values in order of bit lengths */
4290 if ((j = *p++) != 0)
4293 n = x[g]; /* set n to length of v */
4296 /* Generate the Huffman codes and for each, make the table entries */
4297 x[0] = i = 0; /* first Huffman code is zero */
4298 p = v; /* grab values in bit order */
4299 h = -1; /* no tables yet--level -1 */
4300 w = -l; /* bits decoded == (l * h) */
4301 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
4302 q = (inflate_huft *)Z_NULL; /* ditto */
4305 /* go through the bit lengths (k already is bits in shortest code) */
4311 /* here i is the Huffman code of length k bits for value *p */
4312 /* make tables up to required level */
4316 w += l; /* previous table always l bits */
4318 /* compute minimum size table less than or equal to l bits */
4320 z = z > (uInt)l ? l : z; /* table size upper limit */
4321 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
4322 { /* too few codes for k-w bit table */
4323 f -= a + 1; /* deduct codes from patterns left */
4326 while (++j < z) /* try smaller tables up to z bits */
4328 if ((f <<= 1) <= *++xp)
4329 break; /* enough codes to use up j bits */
4330 f -= *xp; /* else deduct codes from patterns */
4333 z = 1 << j; /* table entries for j-bit table */
4335 /* allocate and link in new table */
4336 if ((q = (inflate_huft *)ZALLOC
4337 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
4340 inflate_trees_free(u[0], zs);
4341 return Z_MEM_ERROR; /* not enough memory */
4344 inflate_hufts += z + 1;
4346 *t = q + 1; /* link to list for huft_free() */
4347 *(t = &(q->next)) = Z_NULL;
4348 u[h] = ++q; /* table starts after link */
4350 /* connect to last table, if there is one */
4353 x[h] = i; /* save pattern for backing up */
4354 r.bits = (Byte)l; /* bits to dump before this table */
4355 r.exop = (Byte)j; /* bits in this table */
4356 r.next = q; /* pointer to this table */
4357 j = i >> (w - l); /* (get around Turbo C bug) */
4358 u[h-1][j] = r; /* connect to last table */
4362 /* set up table entry in r */
4363 r.bits = (Byte)(k - w);
4365 r.exop = 128 + 64; /* out of values--invalid code */
4368 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
4369 r.base = *p++; /* simple code is just the value */
4373 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4374 r.base = d[*p++ - s];
4377 /* fill code-like entries with r */
4379 for (j = i >> w; j < z; j += f)
4382 /* backwards increment the k-bit code i */
4383 for (j = 1 << (k - 1); i & j; j >>= 1)
4387 /* backup over finished tables */
4388 while ((i & ((1 << w) - 1)) != x[h])
4390 h--; /* don't need to update q */
4397 /* Return Z_BUF_ERROR if we were given an incomplete table */
4398 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4402 int inflate_trees_bits(c, bb, tb, z)
4403 uIntf *c; /* 19 code lengths */
4404 uIntf *bb; /* bits tree desired/actual depth */
4405 inflate_huft * FAR *tb; /* bits tree result */
4406 z_streamp z; /* for zfree function */
4410 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
4411 if (r == Z_DATA_ERROR)
4412 z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4413 else if (r == Z_BUF_ERROR || *bb == 0)
4415 inflate_trees_free(*tb, z);
4416 z->msg = (char*)"incomplete dynamic bit lengths tree";
4423 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
4424 uInt nl; /* number of literal/length codes */
4425 uInt nd; /* number of distance codes */
4426 uIntf *c; /* that many (total) code lengths */
4427 uIntf *bl; /* literal desired/actual bit depth */
4428 uIntf *bd; /* distance desired/actual bit depth */
4429 inflate_huft * FAR *tl; /* literal/length tree result */
4430 inflate_huft * FAR *td; /* distance tree result */
4431 z_streamp z; /* for zfree function */
4435 /* build literal/length tree */
4436 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z);
4437 if (r != Z_OK || *bl == 0)
4439 if (r == Z_DATA_ERROR)
4440 z->msg = (char*)"oversubscribed literal/length tree";
4441 else if (r != Z_MEM_ERROR)
4443 inflate_trees_free(*tl, z);
4444 z->msg = (char*)"incomplete literal/length tree";
4450 /* build distance tree */
4451 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z);
4452 if (r != Z_OK || (*bd == 0 && nl > 257))
4454 if (r == Z_DATA_ERROR)
4455 z->msg = (char*)"oversubscribed distance tree";
4456 else if (r == Z_BUF_ERROR) {
4457 #ifdef PKZIP_BUG_WORKAROUND
4461 inflate_trees_free(*td, z);
4462 z->msg = (char*)"incomplete distance tree";
4465 else if (r != Z_MEM_ERROR)
4467 z->msg = (char*)"empty distance tree with lengths";
4470 inflate_trees_free(*tl, z);
4480 /* build fixed tables only once--keep them here */
4481 local int fixed_built = 0;
4482 #define FIXEDH 530 /* number of hufts used by fixed tables */
4483 local inflate_huft fixed_mem[FIXEDH];
4484 local uInt fixed_bl;
4485 local uInt fixed_bd;
4486 local inflate_huft *fixed_tl;
4487 local inflate_huft *fixed_td;
4490 local voidpf falloc(q, n, s)
4491 voidpf q; /* opaque pointer */
4492 uInt n; /* number of items */
4493 uInt s; /* size of item */
4495 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q,
4496 "inflate_trees falloc overflow");
4497 *(intf *)q -= n+s-s; /* s-s to avoid warning */
4498 return (voidpf)(fixed_mem + *(intf *)q);
4502 int inflate_trees_fixed(bl, bd, tl, td)
4503 uIntf *bl; /* literal desired/actual bit depth */
4504 uIntf *bd; /* distance desired/actual bit depth */
4505 inflate_huft * FAR *tl; /* literal/length tree result */
4506 inflate_huft * FAR *td; /* distance tree result */
4508 /* build fixed tables if not already (multiple overlapped executions ok) */
4511 int k; /* temporary variable */
4512 unsigned c[288]; /* length list for huft_build */
4513 z_stream z; /* for falloc function */
4514 int f = FIXEDH; /* number of hufts left in fixed_mem */
4516 /* set up fake z_stream for memory routines */
4519 z.opaque = (voidpf)&f;
4522 for (k = 0; k < 144; k++)
4524 for (; k < 256; k++)
4526 for (; k < 280; k++)
4528 for (; k < 288; k++)
4531 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4533 /* distance table */
4534 for (k = 0; k < 30; k++)
4537 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4540 Assert(f == 0, "invalid build of fixed tables");
4551 int inflate_trees_free(t, z)
4552 inflate_huft *t; /* table to free */
4553 z_streamp z; /* for zfree function */
4554 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4555 list of the tables it made, with the links in a dummy first entry of
4558 inflate_huft *p, *q, *r;
4560 /* Reverse linked list */
4570 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4579 /* --- inftrees.c */
4581 /* +++ infcodes.c */
4582 /* infcodes.c -- process literals and length/distance pairs
4583 * Copyright (C) 1995-1996 Mark Adler
4584 * For conditions of distribution and use, see copyright notice in zlib.h
4587 /* #include "zutil.h" */
4588 /* #include "inftrees.h" */
4589 /* #include "infblock.h" */
4590 /* #include "infcodes.h" */
4591 /* #include "infutil.h" */
4594 /* inffast.h -- header to use inffast.c
4595 * Copyright (C) 1995-1996 Mark Adler
4596 * For conditions of distribution and use, see copyright notice in zlib.h
4599 /* WARNING: this file should *not* be used by applications. It is
4600 part of the implementation of the compression library and is
4601 subject to change. Applications should only use zlib.h.
4604 extern int inflate_fast OF((
4609 inflate_blocks_statef *,
4613 /* simplify the use of the inflate_huft type with some defines */
4614 #define base more.Base
4615 #define next more.Next
4616 #define exop word.what.Exop
4617 #define bits word.what.Bits
4619 /* inflate codes private state */
4620 struct inflate_codes_state {
4623 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4624 START, /* x: set up for LEN */
4625 LEN, /* i: get length/literal/eob next */
4626 LENEXT, /* i: getting length extra (have base) */
4627 DIST, /* i: get distance next */
4628 DISTEXT, /* i: getting distance extra */
4629 COPY, /* o: copying bytes in window, waiting for space */
4630 LIT, /* o: got literal, waiting for output space */
4631 WASH, /* o: got eob, possibly still output waiting */
4632 END, /* x: got eob and all data flushed */
4633 BADCODE} /* x: got error */
4634 mode; /* current inflate_codes mode */
4636 /* mode dependent information */
4640 inflate_huft *tree; /* pointer into tree */
4641 uInt need; /* bits needed */
4642 } code; /* if LEN or DIST, where in tree */
4643 uInt lit; /* if LIT, literal */
4645 uInt get; /* bits to get for extra */
4646 uInt dist; /* distance back to copy from */
4647 } copy; /* if EXT or COPY, where and how much */
4648 } sub; /* submode */
4650 /* mode independent information */
4651 Byte lbits; /* ltree bits decoded per branch */
4652 Byte dbits; /* dtree bits decoder per branch */
4653 inflate_huft *ltree; /* literal/length/eob tree */
4654 inflate_huft *dtree; /* distance tree */
4659 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4662 inflate_huft *td; /* need separate declaration for Borland C++ */
4665 inflate_codes_statef *c;
4667 if ((c = (inflate_codes_statef *)
4668 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4671 c->lbits = (Byte)bl;
4672 c->dbits = (Byte)bd;
4675 Tracev((stderr, "inflate: codes new\n"));
4681 int inflate_codes(s, z, r)
4682 inflate_blocks_statef *s;
4686 uInt j; /* temporary storage */
4687 inflate_huft *t; /* temporary pointer */
4688 uInt e; /* extra bits or operation */
4689 uLong b; /* bit buffer */
4690 uInt k; /* bits in bit buffer */
4691 Bytef *p; /* input data pointer */
4692 uInt n; /* bytes available there */
4693 Bytef *q; /* output window write pointer */
4694 uInt m; /* bytes to end of window or read pointer */
4695 Bytef *f; /* pointer to copy strings from */
4696 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4698 /* copy input/output information to locals (UPDATE macro restores) */
4701 /* process input and output based on current state */
4702 while (1) switch (c->mode)
4703 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4704 case START: /* x: set up for LEN */
4706 if (m >= 258 && n >= 10)
4709 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4713 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4718 c->sub.code.need = c->lbits;
4719 c->sub.code.tree = c->ltree;
4721 case LEN: /* i: get length/literal/eob next */
4722 j = c->sub.code.need;
4724 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4726 e = (uInt)(t->exop);
4727 if (e == 0) /* literal */
4729 c->sub.lit = t->base;
4730 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4731 "inflate: literal '%c'\n" :
4732 "inflate: literal 0x%02x\n", t->base));
4736 if (e & 16) /* length */
4738 c->sub.copy.get = e & 15;
4743 if ((e & 64) == 0) /* next table */
4745 c->sub.code.need = e;
4746 c->sub.code.tree = t->next;
4749 if (e & 32) /* end of block */
4751 Tracevv((stderr, "inflate: end of block\n"));
4755 c->mode = BADCODE; /* invalid code */
4756 z->msg = (char*)"invalid literal/length code";
4759 case LENEXT: /* i: getting length extra (have base) */
4760 j = c->sub.copy.get;
4762 c->len += (uInt)b & inflate_mask[j];
4764 c->sub.code.need = c->dbits;
4765 c->sub.code.tree = c->dtree;
4766 Tracevv((stderr, "inflate: length %u\n", c->len));
4768 case DIST: /* i: get distance next */
4769 j = c->sub.code.need;
4771 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4773 e = (uInt)(t->exop);
4774 if (e & 16) /* distance */
4776 c->sub.copy.get = e & 15;
4777 c->sub.copy.dist = t->base;
4781 if ((e & 64) == 0) /* next table */
4783 c->sub.code.need = e;
4784 c->sub.code.tree = t->next;
4787 c->mode = BADCODE; /* invalid code */
4788 z->msg = (char*)"invalid distance code";
4791 case DISTEXT: /* i: getting distance extra */
4792 j = c->sub.copy.get;
4794 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4796 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4798 case COPY: /* o: copying bytes in window, waiting for space */
4799 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4800 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4801 s->end - (c->sub.copy.dist - (q - s->window)) :
4802 q - c->sub.copy.dist;
4804 f = q - c->sub.copy.dist;
4805 if ((uInt)(q - s->window) < c->sub.copy.dist)
4806 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
4818 case LIT: /* o: got literal, waiting for output space */
4823 case WASH: /* o: got eob, possibly more output */
4825 if (s->read != s->write)
4831 case BADCODE: /* x: got error */
4841 void inflate_codes_free(c, z)
4842 inflate_codes_statef *c;
4846 Tracev((stderr, "inflate: codes free\n"));
4848 /* --- infcodes.c */
4851 /* inflate_util.c -- data and routines common to blocks and codes
4852 * Copyright (C) 1995-1996 Mark Adler
4853 * For conditions of distribution and use, see copyright notice in zlib.h
4856 /* #include "zutil.h" */
4857 /* #include "infblock.h" */
4858 /* #include "inftrees.h" */
4859 /* #include "infcodes.h" */
4860 /* #include "infutil.h" */
4862 #ifndef NO_DUMMY_DECL
4863 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4866 /* And'ing with mask[n] masks the lower n bits */
4867 uInt inflate_mask[17] = {
4869 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
4870 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
4874 /* copy as much as possible from the sliding window to the output area */
4875 int inflate_flush(s, z, r)
4876 inflate_blocks_statef *s;
4884 /* local copies of source and destination pointers */
4888 /* compute number of bytes to copy as far as end of window */
4889 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4890 if (n > z->avail_out) n = z->avail_out;
4891 if (n && r == Z_BUF_ERROR) r = Z_OK;
4893 /* update counters */
4897 /* update check information */
4898 if (s->checkfn != Z_NULL)
4899 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4901 /* copy as far as end of window */
4908 /* see if more to copy at beginning of window */
4913 if (s->write == s->end)
4914 s->write = s->window;
4916 /* compute bytes to copy */
4917 n = (uInt)(s->write - q);
4918 if (n > z->avail_out) n = z->avail_out;
4919 if (n && r == Z_BUF_ERROR) r = Z_OK;
4921 /* update counters */
4925 /* update check information */
4926 if (s->checkfn != Z_NULL)
4927 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4937 /* update pointers */
4947 /* inffast.c -- process literals and length/distance pairs fast
4948 * Copyright (C) 1995-1996 Mark Adler
4949 * For conditions of distribution and use, see copyright notice in zlib.h
4952 /* #include "zutil.h" */
4953 /* #include "inftrees.h" */
4954 /* #include "infblock.h" */
4955 /* #include "infcodes.h" */
4956 /* #include "infutil.h" */
4957 /* #include "inffast.h" */
4959 #ifndef NO_DUMMY_DECL
4960 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4963 /* simplify the use of the inflate_huft type with some defines */
4964 #define base more.Base
4965 #define next more.Next
4966 #define exop word.what.Exop
4967 #define bits word.what.Bits
4969 /* macros for bit input with no checking and for returning unused bytes */
4970 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4971 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4973 /* Called with number of bytes left to write in window at least 258
4974 (the maximum string length) and number of input bytes available
4975 at least ten. The ten bytes are six bytes for the longest length/
4976 distance pair plus four bytes for overloading the bit buffer. */
4978 int inflate_fast(bl, bd, tl, td, s, z)
4981 inflate_huft *td; /* need separate declaration for Borland C++ */
4982 inflate_blocks_statef *s;
4985 inflate_huft *t; /* temporary pointer */
4986 uInt e; /* extra bits or operation */
4987 uLong b; /* bit buffer */
4988 uInt k; /* bits in bit buffer */
4989 Bytef *p; /* input data pointer */
4990 uInt n; /* bytes available there */
4991 Bytef *q; /* output window write pointer */
4992 uInt m; /* bytes to end of window or read pointer */
4993 uInt ml; /* mask for literal/length tree */
4994 uInt md; /* mask for distance tree */
4995 uInt c; /* bytes to copy */
4996 uInt d; /* distance back to copy from */
4997 Bytef *r; /* copy source pointer */
4999 /* load input, output, bit values */
5002 /* initialize masks */
5003 ml = inflate_mask[bl];
5004 md = inflate_mask[bd];
5006 /* do until not enough input or output space for fast loop */
5007 do { /* assume called with m >= 258 && n >= 10 */
5008 /* get literal/length code */
5009 GRABBITS(20) /* max bits for literal/length code */
5010 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5013 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5014 "inflate: * literal '%c'\n" :
5015 "inflate: * literal 0x%02x\n", t->base));
5016 *q++ = (Byte)t->base;
5024 /* get extra bits for length */
5026 c = t->base + ((uInt)b & inflate_mask[e]);
5028 Tracevv((stderr, "inflate: * length %u\n", c));
5030 /* decode distance base of block to copy */
5031 GRABBITS(15); /* max bits for distance code */
5032 e = (t = td + ((uInt)b & md))->exop;
5037 /* get extra bits to add to distance base */
5039 GRABBITS(e) /* get extra bits (up to 13) */
5040 d = t->base + ((uInt)b & inflate_mask[e]);
5042 Tracevv((stderr, "inflate: * distance %u\n", d));
5046 if ((uInt)(q - s->window) >= d) /* offset before dest */
5049 *q++ = *r++; c--; /* minimum count is three, */
5050 *q++ = *r++; c--; /* so unroll loop a little */
5052 else /* else offset after destination */
5054 e = d - (uInt)(q - s->window); /* bytes from offset to end */
5055 r = s->end - e; /* pointer to offset */
5056 if (c > e) /* if source crosses, */
5058 c -= e; /* copy to end of window */
5062 r = s->window; /* copy rest from start of window */
5065 do { /* copy all or what's left */
5070 else if ((e & 64) == 0)
5071 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
5074 z->msg = (char*)"invalid distance code";
5077 return Z_DATA_ERROR;
5084 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
5087 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5088 "inflate: * literal '%c'\n" :
5089 "inflate: * literal 0x%02x\n", t->base));
5090 *q++ = (Byte)t->base;
5097 Tracevv((stderr, "inflate: * end of block\n"));
5100 return Z_STREAM_END;
5104 z->msg = (char*)"invalid literal/length code";
5107 return Z_DATA_ERROR;
5110 } while (m >= 258 && n >= 10);
5112 /* not enough input or output--restore pointers and return */
5120 /* zutil.c -- target dependent utility functions for the compression library
5121 * Copyright (C) 1995-1996 Jean-loup Gailly.
5122 * For conditions of distribution and use, see copyright notice in zlib.h
5125 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */
5131 /* #include "zutil.h" */
5133 #ifndef NO_DUMMY_DECL
5134 struct internal_state {int dummy;}; /* for buggy compilers */
5138 extern void exit OF((int));
5141 static const char *z_errmsg[10] = {
5142 "need dictionary", /* Z_NEED_DICT 2 */
5143 "stream end", /* Z_STREAM_END 1 */
5145 "file error", /* Z_ERRNO (-1) */
5146 "stream error", /* Z_STREAM_ERROR (-2) */
5147 "data error", /* Z_DATA_ERROR (-3) */
5148 "insufficient memory", /* Z_MEM_ERROR (-4) */
5149 "buffer error", /* Z_BUF_ERROR (-5) */
5150 "incompatible version",/* Z_VERSION_ERROR (-6) */
5154 const char *zlibVersion()
5156 return ZLIB_VERSION;
5163 fprintf(stderr, "%s\n", m);
5170 void zmemcpy(dest, source, len)
5175 if (len == 0) return;
5177 *dest++ = *source++; /* ??? to be unrolled */
5178 } while (--len != 0);
5181 int zmemcmp(s1, s2, len)
5188 for (j = 0; j < len; j++) {
5189 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5194 void zmemzero(dest, len)
5198 if (len == 0) return;
5200 *dest++ = 0; /* ??? to be unrolled */
5201 } while (--len != 0);
5206 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5207 /* Small and medium model in Turbo C are for now limited to near allocation
5208 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5212 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5213 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5214 * must fix the pointer. Warning: the pointer must be put back to its
5215 * original form in order to free it, use zcfree().
5221 local int next_ptr = 0;
5223 typedef struct ptr_table_s {
5228 local ptr_table table[MAX_PTR];
5229 /* This table is used to remember the original form of pointers
5230 * to large buffers (64K). Such pointers are normalized with a zero offset.
5231 * Since MSDOS is not a preemptive multitasking OS, this table is not
5232 * protected from concurrent access. This hack doesn't work anyway on
5233 * a protected system like OS/2. Use Microsoft C instead.
5236 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5238 voidpf buf = opaque; /* just to make some compilers happy */
5239 ulg bsize = (ulg)items*size;
5241 /* If we allocate less than 65520 bytes, we assume that farmalloc
5242 * will return a usable pointer which doesn't have to be normalized.
5244 if (bsize < 65520L) {
5245 buf = farmalloc(bsize);
5246 if (*(ush*)&buf != 0) return buf;
5248 buf = farmalloc(bsize + 16L);
5250 if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5251 table[next_ptr].org_ptr = buf;
5253 /* Normalize the pointer to seg:0 */
5254 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5256 table[next_ptr++].new_ptr = buf;
5260 void zcfree (voidpf opaque, voidpf ptr)
5263 if (*(ush*)&ptr != 0) { /* object < 64K */
5267 /* Find the original pointer */
5268 for (n = 0; n < next_ptr; n++) {
5269 if (ptr != table[n].new_ptr) continue;
5271 farfree(table[n].org_ptr);
5272 while (++n < next_ptr) {
5273 table[n-1] = table[n];
5278 ptr = opaque; /* just to make some compilers happy */
5279 Assert(0, "zcfree: ptr not found");
5282 #endif /* __TURBOC__ */
5285 #if defined(M_I86) && !defined(__32BIT__)
5286 /* Microsoft C in 16-bit mode */
5290 #if (!defined(_MSC_VER) || (_MSC_VER < 600))
5291 # define _halloc halloc
5292 # define _hfree hfree
5295 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5297 if (opaque) opaque = 0; /* to make compiler happy */
5298 return _halloc((long)items, size);
5301 void zcfree (voidpf opaque, voidpf ptr)
5303 if (opaque) opaque = 0; /* to make compiler happy */
5310 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5313 extern voidp calloc OF((uInt items, uInt size));
5314 extern void free OF((voidpf ptr));
5317 voidpf zcalloc (opaque, items, size)
5322 if (opaque) items += size - size; /* make compiler happy */
5323 return (voidpf)calloc(items, size);
5326 void zcfree (opaque, ptr)
5331 if (opaque) return; /* make compiler happy */
5334 #endif /* MY_ZCALLOC */
5338 /* adler32.c -- compute the Adler-32 checksum of a data stream
5339 * Copyright (C) 1995-1996 Mark Adler
5340 * For conditions of distribution and use, see copyright notice in zlib.h
5343 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */
5345 /* #include "zlib.h" */
5347 #define BASE 65521L /* largest prime smaller than 65536 */
5349 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5351 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;}
5352 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
5353 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
5354 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
5355 #define DO16(buf) DO8(buf,0); DO8(buf,8);
5357 /* ========================================================================= */
5358 uLong adler32(adler, buf, len)
5363 unsigned long s1 = adler & 0xffff;
5364 unsigned long s2 = (adler >> 16) & 0xffff;
5367 if (buf == Z_NULL) return 1L;
5370 k = len < NMAX ? len : NMAX;
5384 return (s2 << 16) | s1;