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 1.9 2005/12/11 13:28:53 swildner 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 /* ========================================================================= */
728 deflateInit_(z_streamp strm, int level, const char * version,
731 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
732 Z_DEFAULT_STRATEGY, version, stream_size);
733 /* To do: ignore strm->next_in if we use it as window */
736 /* ========================================================================= */
738 deflateInit2_(z_streamp strm, int level, int method, int windowBits,
739 int memLevel, int strategy, const char *version,
744 static char* my_version = ZLIB_VERSION;
747 /* We overlay pending_buf and d_buf+l_buf. This works since the average
748 * output size for (length,distance) codes is <= 24 bits.
751 if (version == Z_NULL || version[0] != my_version[0] ||
752 stream_size != sizeof(z_stream)) {
753 return Z_VERSION_ERROR;
755 if (strm == Z_NULL) return Z_STREAM_ERROR;
759 if (strm->zalloc == Z_NULL) {
760 strm->zalloc = zcalloc;
761 strm->opaque = (voidpf)0;
763 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
766 if (level == Z_DEFAULT_COMPRESSION) level = 6;
768 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
770 windowBits = -windowBits;
772 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
773 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
774 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
775 return Z_STREAM_ERROR;
777 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
778 if (s == Z_NULL) return Z_MEM_ERROR;
779 strm->state = (struct internal_state FAR *)s;
782 s->noheader = noheader;
783 s->w_bits = windowBits;
784 s->w_size = 1 << s->w_bits;
785 s->w_mask = s->w_size - 1;
787 s->hash_bits = memLevel + 7;
788 s->hash_size = 1 << s->hash_bits;
789 s->hash_mask = s->hash_size - 1;
790 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
792 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
793 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
794 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
796 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
798 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
799 s->pending_buf = (uchf *) overlay;
800 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
802 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
803 s->pending_buf == Z_NULL) {
804 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR);
808 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
809 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
812 s->strategy = strategy;
813 s->method = (Byte)method;
815 return deflateReset(strm);
818 /* ========================================================================= */
820 deflateSetDictionary(z_streamp strm, const Bytef *dictionary, uInt dictLength)
823 uInt length = dictLength;
827 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
828 return Z_STREAM_ERROR;
830 s = (deflate_state *) strm->state;
831 if (s->status != INIT_STATE) return Z_STREAM_ERROR;
833 strm->adler = adler32(strm->adler, dictionary, dictLength);
835 if (length < MIN_MATCH) return Z_OK;
836 if (length > MAX_DIST(s)) {
837 length = MAX_DIST(s);
838 #ifndef USE_DICT_HEAD
839 dictionary += dictLength - length; /* use the tail of the dictionary */
842 zmemcpy((charf *)s->window, dictionary, length);
843 s->strstart = length;
844 s->block_start = (long)length;
846 /* Insert all strings in the hash table (except for the last two bytes).
847 * s->lookahead stays null, so s->ins_h will be recomputed at the next
848 * call of fill_window.
850 s->ins_h = s->window[0];
851 UPDATE_HASH(s, s->ins_h, s->window[1]);
852 for (n = 0; n <= length - MIN_MATCH; n++) {
853 INSERT_STRING(s, n, hash_head);
855 if (hash_head) hash_head = 0; /* to make compiler happy */
859 /* ========================================================================= */
861 deflateReset(z_streamp strm)
865 if (strm == Z_NULL || strm->state == Z_NULL ||
866 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
868 strm->total_in = strm->total_out = 0;
869 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
870 strm->data_type = Z_UNKNOWN;
872 s = (deflate_state *)strm->state;
874 s->pending_out = s->pending_buf;
876 if (s->noheader < 0) {
877 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
879 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
881 s->last_flush = Z_NO_FLUSH;
889 /* ========================================================================= */
891 deflateParams(z_streamp strm, int level, int strategy)
897 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
898 s = (deflate_state *) strm->state;
900 if (level == Z_DEFAULT_COMPRESSION) {
903 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
904 return Z_STREAM_ERROR;
906 func = configuration_table[s->level].func;
908 if (func != configuration_table[level].func && strm->total_in != 0) {
909 /* Flush the last buffer: */
910 err = deflate(strm, Z_PARTIAL_FLUSH);
912 if (s->level != level) {
914 s->max_lazy_match = configuration_table[level].max_lazy;
915 s->good_match = configuration_table[level].good_length;
916 s->nice_match = configuration_table[level].nice_length;
917 s->max_chain_length = configuration_table[level].max_chain;
919 s->strategy = strategy;
923 /* =========================================================================
924 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
925 * IN assertion: the stream state is correct and there is enough room in
929 putShortMSB(deflate_state *s, uInt b)
931 put_byte(s, (Byte)(b >> 8));
932 put_byte(s, (Byte)(b & 0xff));
935 /* =========================================================================
936 * Flush as much pending output as possible. All deflate() output goes
937 * through this function so some applications may wish to modify it
938 * to avoid allocating a large strm->next_out buffer and copying into it.
939 * (See also read_buf()).
942 flush_pending(z_streamp strm)
944 deflate_state *s = (deflate_state *) strm->state;
945 unsigned len = s->pending;
947 if (len > strm->avail_out) len = strm->avail_out;
948 if (len == 0) return;
950 if (strm->next_out != Z_NULL) {
951 zmemcpy(strm->next_out, s->pending_out, len);
952 strm->next_out += len;
954 s->pending_out += len;
955 strm->total_out += len;
956 strm->avail_out -= len;
958 if (s->pending == 0) {
959 s->pending_out = s->pending_buf;
963 /* ========================================================================= */
965 deflate(z_streamp strm, int flush)
967 int old_flush; /* value of flush param for previous deflate call */
970 if (strm == Z_NULL || strm->state == Z_NULL ||
971 flush > Z_FINISH || flush < 0) {
972 return Z_STREAM_ERROR;
974 s = (deflate_state *) strm->state;
976 if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
977 (s->status == FINISH_STATE && flush != Z_FINISH)) {
978 ERR_RETURN(strm, Z_STREAM_ERROR);
980 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
982 s->strm = strm; /* just in case */
983 old_flush = s->last_flush;
984 s->last_flush = flush;
986 /* Write the zlib header */
987 if (s->status == INIT_STATE) {
989 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
990 uInt level_flags = (s->level-1) >> 1;
992 if (level_flags > 3) level_flags = 3;
993 header |= (level_flags << 6);
994 if (s->strstart != 0) header |= PRESET_DICT;
995 header += 31 - (header % 31);
997 s->status = BUSY_STATE;
998 putShortMSB(s, header);
1000 /* Save the adler32 of the preset dictionary: */
1001 if (s->strstart != 0) {
1002 putShortMSB(s, (uInt)(strm->adler >> 16));
1003 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1008 /* Flush as much pending output as possible */
1009 if (s->pending != 0) {
1010 flush_pending(strm);
1011 if (strm->avail_out == 0) {
1012 /* Since avail_out is 0, deflate will be called again with
1013 * more output space, but possibly with both pending and
1014 * avail_in equal to zero. There won't be anything to do,
1015 * but this is not an error situation so make sure we
1016 * return OK instead of BUF_ERROR at next call of deflate:
1022 /* Make sure there is something to do and avoid duplicate consecutive
1023 * flushes. For repeated and useless calls with Z_FINISH, we keep
1024 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1026 } else if (strm->avail_in == 0 && flush <= old_flush &&
1027 flush != Z_FINISH) {
1028 ERR_RETURN(strm, Z_BUF_ERROR);
1031 /* User must not provide more input after the first FINISH: */
1032 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1033 ERR_RETURN(strm, Z_BUF_ERROR);
1036 /* Start a new block or continue the current one.
1038 if (strm->avail_in != 0 || s->lookahead != 0 ||
1039 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1042 bstate = (*(configuration_table[s->level].func))(s, flush);
1044 if (bstate == finish_started || bstate == finish_done) {
1045 s->status = FINISH_STATE;
1047 if (bstate == need_more || bstate == finish_started) {
1048 if (strm->avail_out == 0) {
1049 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1052 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1053 * of deflate should use the same flush parameter to make sure
1054 * that the flush is complete. So we don't have to output an
1055 * empty block here, this will be done at next call. This also
1056 * ensures that for a very small output buffer, we emit at most
1060 if (bstate == block_done) {
1061 if (flush == Z_PARTIAL_FLUSH) {
1063 } else if (flush == Z_PACKET_FLUSH) {
1064 /* Output just the 3-bit `stored' block type value,
1065 but not a zero length. */
1066 _tr_stored_type_only(s);
1067 } else { /* FULL_FLUSH or SYNC_FLUSH */
1068 _tr_stored_block(s, (char*)0, 0L, 0);
1069 /* For a full flush, this empty block will be recognized
1070 * as a special marker by inflate_sync().
1072 if (flush == Z_FULL_FLUSH) {
1073 CLEAR_HASH(s); /* forget history */
1076 flush_pending(strm);
1077 if (strm->avail_out == 0) {
1078 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1083 Assert(strm->avail_out > 0, "bug2");
1085 if (flush != Z_FINISH) return Z_OK;
1086 if (s->noheader) return Z_STREAM_END;
1088 /* Write the zlib trailer (adler32) */
1089 putShortMSB(s, (uInt)(strm->adler >> 16));
1090 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1091 flush_pending(strm);
1092 /* If avail_out is zero, the application will call deflate again
1093 * to flush the rest.
1095 s->noheader = -1; /* write the trailer only once! */
1096 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1099 /* ========================================================================= */
1101 deflateEnd(z_streamp strm)
1106 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1107 s = (deflate_state *) strm->state;
1110 if (status != INIT_STATE && status != BUSY_STATE &&
1111 status != FINISH_STATE) {
1112 return Z_STREAM_ERROR;
1115 /* Deallocate in reverse order of allocations: */
1116 TRY_FREE(strm, s->pending_buf);
1117 TRY_FREE(strm, s->head);
1118 TRY_FREE(strm, s->prev);
1119 TRY_FREE(strm, s->window);
1122 strm->state = Z_NULL;
1124 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1127 /* =========================================================================
1128 * Copy the source state to the destination state.
1131 deflateCopy(z_streamp dest, z_streamp source)
1137 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
1138 return Z_STREAM_ERROR;
1139 ss = (deflate_state *) source->state;
1141 zmemcpy(dest, source, sizeof(*dest));
1143 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1144 if (ds == Z_NULL) return Z_MEM_ERROR;
1145 dest->state = (struct internal_state FAR *) ds;
1146 zmemcpy(ds, ss, sizeof(*ds));
1149 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1150 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1151 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1152 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1153 ds->pending_buf = (uchf *) overlay;
1155 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1156 ds->pending_buf == Z_NULL) {
1160 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */
1161 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1162 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1163 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1164 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1166 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1167 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1168 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1170 ds->l_desc.dyn_tree = ds->dyn_ltree;
1171 ds->d_desc.dyn_tree = ds->dyn_dtree;
1172 ds->bl_desc.dyn_tree = ds->bl_tree;
1177 /* ===========================================================================
1178 * Return the number of bytes of output which are immediately available
1179 * for output from the decompressor.
1182 deflateOutputPending(z_streamp strm)
1184 if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1186 return ((deflate_state *)(strm->state))->pending;
1189 /* ===========================================================================
1190 * Read a new buffer from the current input stream, update the adler32
1191 * and total number of bytes read. All deflate() input goes through
1192 * this function so some applications may wish to modify it to avoid
1193 * allocating a large strm->next_in buffer and copying from it.
1194 * (See also flush_pending()).
1197 read_buf(z_streamp strm, charf *buf, unsigned size)
1199 unsigned len = strm->avail_in;
1201 if (len > size) len = size;
1202 if (len == 0) return 0;
1204 strm->avail_in -= len;
1206 if (!((deflate_state *)(strm->state))->noheader) {
1207 strm->adler = adler32(strm->adler, strm->next_in, len);
1209 zmemcpy(buf, strm->next_in, len);
1210 strm->next_in += len;
1211 strm->total_in += len;
1216 /* ===========================================================================
1217 * Initialize the "longest match" routines for a new zlib stream
1220 lm_init(deflate_state *s)
1222 s->window_size = (ulg)2L*s->w_size;
1226 /* Set the default configuration parameters:
1228 s->max_lazy_match = configuration_table[s->level].max_lazy;
1229 s->good_match = configuration_table[s->level].good_length;
1230 s->nice_match = configuration_table[s->level].nice_length;
1231 s->max_chain_length = configuration_table[s->level].max_chain;
1234 s->block_start = 0L;
1236 s->match_length = s->prev_length = MIN_MATCH-1;
1237 s->match_available = 0;
1240 match_init(); /* initialize the asm code */
1244 /* ===========================================================================
1245 * Set match_start to the longest match starting at the given string and
1246 * return its length. Matches shorter or equal to prev_length are discarded,
1247 * in which case the result is equal to prev_length and match_start is
1249 * IN assertions: cur_match is the head of the hash chain for the current
1250 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1251 * OUT assertion: the match length is not greater than s->lookahead.
1254 * cur_match: current match
1257 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1258 * match.S. The code will be functionally equivalent.
1261 longest_match(deflate_state *s, IPos cur_match)
1263 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1264 Bytef *scan = s->window + s->strstart; /* current string */
1265 Bytef *match; /* matched string */
1266 int len; /* length of current match */
1267 int best_len = s->prev_length; /* best match length so far */
1268 int nice_match = s->nice_match; /* stop if match long enough */
1269 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1270 s->strstart - (IPos)MAX_DIST(s) : NIL;
1271 /* Stop when cur_match becomes <= limit. To simplify the code,
1272 * we prevent matches with the string of window index 0.
1274 Posf *prev = s->prev;
1275 uInt wmask = s->w_mask;
1278 /* Compare two bytes at a time. Note: this is not always beneficial.
1279 * Try with and without -DUNALIGNED_OK to check.
1281 Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1282 ush scan_start = *(ushf*)scan;
1283 ush scan_end = *(ushf*)(scan+best_len-1);
1285 Bytef *strend = s->window + s->strstart + MAX_MATCH;
1286 Byte scan_end1 = scan[best_len-1];
1287 Byte scan_end = scan[best_len];
1290 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1291 * It is easy to get rid of this optimization if necessary.
1293 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1295 /* Do not waste too much time if we already have a good match: */
1296 if (s->prev_length >= s->good_match) {
1299 /* Do not look for matches beyond the end of the input. This is necessary
1300 * to make deflate deterministic.
1302 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1304 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1307 Assert(cur_match < s->strstart, "no future");
1308 match = s->window + cur_match;
1310 /* Skip to next match if the match length cannot increase
1311 * or if the match length is less than 2:
1313 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1314 /* This code assumes sizeof(unsigned short) == 2. Do not use
1315 * UNALIGNED_OK if your compiler uses a different size.
1317 if (*(ushf*)(match+best_len-1) != scan_end ||
1318 *(ushf*)match != scan_start) continue;
1320 /* It is not necessary to compare scan[2] and match[2] since they are
1321 * always equal when the other bytes match, given that the hash keys
1322 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1323 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1324 * lookahead only every 4th comparison; the 128th check will be made
1325 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1326 * necessary to put more guard bytes at the end of the window, or
1327 * to check more often for insufficient lookahead.
1329 Assert(scan[2] == match[2], "scan[2]?");
1332 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1333 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1334 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1335 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1337 /* The funny "do {}" generates better code on most compilers */
1339 /* Here, scan <= window+strstart+257 */
1340 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1341 if (*scan == *match) scan++;
1343 len = (MAX_MATCH - 1) - (int)(strend-scan);
1344 scan = strend - (MAX_MATCH-1);
1346 #else /* UNALIGNED_OK */
1348 if (match[best_len] != scan_end ||
1349 match[best_len-1] != scan_end1 ||
1351 *++match != scan[1]) continue;
1353 /* The check at best_len-1 can be removed because it will be made
1354 * again later. (This heuristic is not always a win.)
1355 * It is not necessary to compare scan[2] and match[2] since they
1356 * are always equal when the other bytes match, given that
1357 * the hash keys are equal and that HASH_BITS >= 8.
1360 Assert(*scan == *match, "match[2]?");
1362 /* We check for insufficient lookahead only every 8th comparison;
1363 * the 256th check will be made at strstart+258.
1366 } while (*++scan == *++match && *++scan == *++match &&
1367 *++scan == *++match && *++scan == *++match &&
1368 *++scan == *++match && *++scan == *++match &&
1369 *++scan == *++match && *++scan == *++match &&
1372 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1374 len = MAX_MATCH - (int)(strend - scan);
1375 scan = strend - MAX_MATCH;
1377 #endif /* UNALIGNED_OK */
1379 if (len > best_len) {
1380 s->match_start = cur_match;
1382 if (len >= nice_match) break;
1384 scan_end = *(ushf*)(scan+best_len-1);
1386 scan_end1 = scan[best_len-1];
1387 scan_end = scan[best_len];
1390 } while ((cur_match = prev[cur_match & wmask]) > limit
1391 && --chain_length != 0);
1393 if ((uInt)best_len <= s->lookahead) return best_len;
1394 return s->lookahead;
1399 /* ===========================================================================
1400 * Check that the match at match_start is indeed a match.
1403 check_match(deflate_state *s, IPos start, IPos match, int length)
1405 /* check that the match is indeed a match */
1406 if (zmemcmp((charf *)s->window + match,
1407 (charf *)s->window + start, length) != EQUAL) {
1408 fprintf(stderr, " start %u, match %u, length %d\n",
1409 start, match, length);
1411 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1412 } while (--length != 0);
1413 z_error("invalid match");
1415 if (z_verbose > 1) {
1416 fprintf(stderr,"\\[%d,%d]", start-match, length);
1417 do { putc(s->window[start++], stderr); } while (--length != 0);
1421 # define check_match(s, start, match, length)
1424 /* ===========================================================================
1425 * Fill the window when the lookahead becomes insufficient.
1426 * Updates strstart and lookahead.
1428 * IN assertion: lookahead < MIN_LOOKAHEAD
1429 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1430 * At least one byte has been read, or avail_in == 0; reads are
1431 * performed for at least two bytes (required for the zip translate_eol
1432 * option -- not supported here).
1435 fill_window(deflate_state *s)
1439 unsigned more; /* Amount of free space at the end of the window. */
1440 uInt wsize = s->w_size;
1443 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1445 /* Deal with !@#$% 64K limit: */
1446 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1449 } else if (more == (unsigned)(-1)) {
1450 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1451 * and lookahead == 1 (input done one byte at time)
1455 /* If the window is almost full and there is insufficient lookahead,
1456 * move the upper half to the lower one to make room in the upper half.
1458 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1460 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1462 s->match_start -= wsize;
1463 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1464 s->block_start -= (long) wsize;
1466 /* Slide the hash table (could be avoided with 32 bit values
1467 at the expense of memory usage). We slide even when level == 0
1468 to keep the hash table consistent if we switch back to level > 0
1469 later. (Using level 0 permanently is not an optimal usage of
1470 zlib, so we don't care about this pathological case.)
1476 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1483 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1484 /* If n is not on any hash chain, prev[n] is garbage but
1485 * its value will never be used.
1490 if (s->strm->avail_in == 0) return;
1492 /* If there was no sliding:
1493 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1494 * more == window_size - lookahead - strstart
1495 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1496 * => more >= window_size - 2*WSIZE + 2
1497 * In the BIG_MEM or MMAP case (not yet supported),
1498 * window_size == input_size + MIN_LOOKAHEAD &&
1499 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1500 * Otherwise, window_size == 2*WSIZE so more >= 2.
1501 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1503 Assert(more >= 2, "more < 2");
1505 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1509 /* Initialize the hash value now that we have some input: */
1510 if (s->lookahead >= MIN_MATCH) {
1511 s->ins_h = s->window[s->strstart];
1512 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1514 Call UPDATE_HASH() MIN_MATCH-3 more times
1517 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1518 * but this is not important since only literal bytes will be emitted.
1521 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1524 /* ===========================================================================
1525 * Flush the current block, with given end-of-file flag.
1526 * IN assertion: strstart is set to the end of the current match.
1528 #define FLUSH_BLOCK_ONLY(s, eof) { \
1529 _tr_flush_block(s, (s->block_start >= 0L ? \
1530 (charf *)&s->window[(unsigned)s->block_start] : \
1532 (ulg)((long)s->strstart - s->block_start), \
1534 s->block_start = s->strstart; \
1535 flush_pending(s->strm); \
1536 Tracev((stderr,"[FLUSH]")); \
1539 /* Same but force premature exit if necessary. */
1540 #define FLUSH_BLOCK(s, eof) { \
1541 FLUSH_BLOCK_ONLY(s, eof); \
1542 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1545 /* ===========================================================================
1546 * Copy without compression as much as possible from the input stream, return
1547 * the current block state.
1548 * This function does not insert new strings in the dictionary since
1549 * uncompressible data is probably not useful. This function is used
1550 * only for the level=0 compression option.
1551 * NOTE: this function should be optimized to avoid extra copying from
1552 * window to pending_buf.
1555 deflate_stored(deflate_state *s, int flush)
1557 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1558 * to pending_buf_size, and each stored block has a 5 byte header:
1560 ulg max_block_size = 0xffff;
1563 if (max_block_size > s->pending_buf_size - 5) {
1564 max_block_size = s->pending_buf_size - 5;
1567 /* Copy as much as possible from input to output: */
1569 /* Fill the window as much as possible: */
1570 if (s->lookahead <= 1) {
1572 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1573 s->block_start >= (long)s->w_size, "slide too late");
1576 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1578 if (s->lookahead == 0) break; /* flush the current block */
1580 Assert(s->block_start >= 0L, "block gone");
1582 s->strstart += s->lookahead;
1585 /* Emit a stored block if pending_buf will be full: */
1586 max_start = s->block_start + max_block_size;
1587 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1588 /* strstart == 0 is possible when wraparound on 16-bit machine */
1589 s->lookahead = (uInt)(s->strstart - max_start);
1590 s->strstart = (uInt)max_start;
1593 /* Flush if we may have to slide, otherwise block_start may become
1594 * negative and the data will be gone:
1596 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1600 FLUSH_BLOCK(s, flush == Z_FINISH);
1601 return flush == Z_FINISH ? finish_done : block_done;
1604 /* ===========================================================================
1605 * Compress as much as possible from the input stream, return the current
1607 * This function does not perform lazy evaluation of matches and inserts
1608 * new strings in the dictionary only for unmatched strings or for short
1609 * matches. It is used only for the fast compression options.
1612 deflate_fast(deflate_state *s, int flush)
1614 IPos hash_head = NIL; /* head of the hash chain */
1615 int bflush; /* set if current block must be flushed */
1618 /* Make sure that we always have enough lookahead, except
1619 * at the end of the input file. We need MAX_MATCH bytes
1620 * for the next match, plus MIN_MATCH bytes to insert the
1621 * string following the next match.
1623 if (s->lookahead < MIN_LOOKAHEAD) {
1625 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1628 if (s->lookahead == 0) break; /* flush the current block */
1631 /* Insert the string window[strstart .. strstart+2] in the
1632 * dictionary, and set hash_head to the head of the hash chain:
1634 if (s->lookahead >= MIN_MATCH) {
1635 INSERT_STRING(s, s->strstart, hash_head);
1638 /* Find the longest match, discarding those <= prev_length.
1639 * At this point we have always match_length < MIN_MATCH
1641 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1642 /* To simplify the code, we prevent matches with the string
1643 * of window index 0 (in particular we have to avoid a match
1644 * of the string with itself at the start of the input file).
1646 if (s->strategy != Z_HUFFMAN_ONLY) {
1647 s->match_length = longest_match (s, hash_head);
1649 /* longest_match() sets match_start */
1651 if (s->match_length >= MIN_MATCH) {
1652 check_match(s, s->strstart, s->match_start, s->match_length);
1654 bflush = _tr_tally(s, s->strstart - s->match_start,
1655 s->match_length - MIN_MATCH);
1657 s->lookahead -= s->match_length;
1659 /* Insert new strings in the hash table only if the match length
1660 * is not too large. This saves time but degrades compression.
1662 if (s->match_length <= s->max_insert_length &&
1663 s->lookahead >= MIN_MATCH) {
1664 s->match_length--; /* string at strstart already in hash table */
1667 INSERT_STRING(s, s->strstart, hash_head);
1668 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1669 * always MIN_MATCH bytes ahead.
1671 } while (--s->match_length != 0);
1674 s->strstart += s->match_length;
1675 s->match_length = 0;
1676 s->ins_h = s->window[s->strstart];
1677 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1679 Call UPDATE_HASH() MIN_MATCH-3 more times
1681 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1682 * matter since it will be recomputed at next deflate call.
1686 /* No match, output a literal byte */
1687 Tracevv((stderr,"%c", s->window[s->strstart]));
1688 bflush = _tr_tally (s, 0, s->window[s->strstart]);
1692 if (bflush) FLUSH_BLOCK(s, 0);
1694 FLUSH_BLOCK(s, flush == Z_FINISH);
1695 return flush == Z_FINISH ? finish_done : block_done;
1698 /* ===========================================================================
1699 * Same as above, but achieves better compression. We use a lazy
1700 * evaluation for matches: a match is finally adopted only if there is
1701 * no better match at the next window position.
1704 deflate_slow(deflate_state *s, int flush)
1706 IPos hash_head = NIL; /* head of hash chain */
1707 int bflush; /* set if current block must be flushed */
1709 /* Process the input block. */
1711 /* Make sure that we always have enough lookahead, except
1712 * at the end of the input file. We need MAX_MATCH bytes
1713 * for the next match, plus MIN_MATCH bytes to insert the
1714 * string following the next match.
1716 if (s->lookahead < MIN_LOOKAHEAD) {
1718 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1721 if (s->lookahead == 0) break; /* flush the current block */
1724 /* Insert the string window[strstart .. strstart+2] in the
1725 * dictionary, and set hash_head to the head of the hash chain:
1727 if (s->lookahead >= MIN_MATCH) {
1728 INSERT_STRING(s, s->strstart, hash_head);
1731 /* Find the longest match, discarding those <= prev_length.
1733 s->prev_length = s->match_length, s->prev_match = s->match_start;
1734 s->match_length = MIN_MATCH-1;
1736 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1737 s->strstart - hash_head <= MAX_DIST(s)) {
1738 /* To simplify the code, we prevent matches with the string
1739 * of window index 0 (in particular we have to avoid a match
1740 * of the string with itself at the start of the input file).
1742 if (s->strategy != Z_HUFFMAN_ONLY) {
1743 s->match_length = longest_match (s, hash_head);
1745 /* longest_match() sets match_start */
1747 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1748 (s->match_length == MIN_MATCH &&
1749 s->strstart - s->match_start > TOO_FAR))) {
1751 /* If prev_match is also MIN_MATCH, match_start is garbage
1752 * but we will ignore the current match anyway.
1754 s->match_length = MIN_MATCH-1;
1757 /* If there was a match at the previous step and the current
1758 * match is not better, output the previous match:
1760 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1761 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1762 /* Do not insert strings in hash table beyond this. */
1764 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1766 bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
1767 s->prev_length - MIN_MATCH);
1769 /* Insert in hash table all strings up to the end of the match.
1770 * strstart-1 and strstart are already inserted. If there is not
1771 * enough lookahead, the last two strings are not inserted in
1774 s->lookahead -= s->prev_length-1;
1775 s->prev_length -= 2;
1777 if (++s->strstart <= max_insert) {
1778 INSERT_STRING(s, s->strstart, hash_head);
1780 } while (--s->prev_length != 0);
1781 s->match_available = 0;
1782 s->match_length = MIN_MATCH-1;
1785 if (bflush) FLUSH_BLOCK(s, 0);
1787 } else if (s->match_available) {
1788 /* If there was no match at the previous position, output a
1789 * single literal. If there was a match but the current match
1790 * is longer, truncate the previous match to a single literal.
1792 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1793 if (_tr_tally (s, 0, s->window[s->strstart-1])) {
1794 FLUSH_BLOCK_ONLY(s, 0);
1798 if (s->strm->avail_out == 0) return need_more;
1800 /* There is no previous match to compare with, wait for
1801 * the next step to decide.
1803 s->match_available = 1;
1808 Assert (flush != Z_NO_FLUSH, "no flush?");
1809 if (s->match_available) {
1810 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1811 _tr_tally (s, 0, s->window[s->strstart-1]);
1812 s->match_available = 0;
1814 FLUSH_BLOCK(s, flush == Z_FINISH);
1815 return flush == Z_FINISH ? finish_done : block_done;
1820 /* trees.c -- output deflated data using Huffman coding
1821 * Copyright (C) 1995-1996 Jean-loup Gailly
1822 * For conditions of distribution and use, see copyright notice in zlib.h
1828 * The "deflation" process uses several Huffman trees. The more
1829 * common source values are represented by shorter bit sequences.
1831 * Each code tree is stored in a compressed form which is itself
1832 * a Huffman encoding of the lengths of all the code strings (in
1833 * ascending order by source values). The actual code strings are
1834 * reconstructed from the lengths in the inflate process, as described
1835 * in the deflate specification.
1839 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1840 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1843 * Data Compression: Methods and Theory, pp. 49-50.
1844 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1848 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1851 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
1853 /* #include "deflate.h" */
1859 /* ===========================================================================
1863 #define MAX_BL_BITS 7
1864 /* Bit length codes must not exceed MAX_BL_BITS bits */
1866 #define END_BLOCK 256
1867 /* end of block literal code */
1870 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1872 #define REPZ_3_10 17
1873 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1875 #define REPZ_11_138 18
1876 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1878 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1879 = {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};
1881 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1882 = {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};
1884 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1885 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1887 local uch bl_order[BL_CODES]
1888 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1889 /* The lengths of the bit length codes are sent in order of decreasing
1890 * probability, to avoid transmitting the lengths for unused bit length codes.
1893 #define Buf_size (8 * 2*sizeof(char))
1894 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1895 * more than 16 bits on some systems.)
1898 /* ===========================================================================
1899 * Local data. These are initialized only once.
1902 local ct_data static_ltree[L_CODES+2];
1903 /* The static literal tree. Since the bit lengths are imposed, there is no
1904 * need for the L_CODES extra codes used during heap construction. However
1905 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
1909 local ct_data static_dtree[D_CODES];
1910 /* The static distance tree. (Actually a trivial tree since all codes use
1914 local uch dist_code[512];
1915 /* distance codes. The first 256 values correspond to the distances
1916 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1917 * the 15 bit distances.
1920 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1921 /* length code for each normalized match length (0 == MIN_MATCH) */
1923 local int base_length[LENGTH_CODES];
1924 /* First normalized length for each code (0 = MIN_MATCH) */
1926 local int base_dist[D_CODES];
1927 /* First normalized distance for each code (0 = distance of 1) */
1929 struct static_tree_desc_s {
1930 ct_data *static_tree; /* static tree or NULL */
1931 intf *extra_bits; /* extra bits for each code or NULL */
1932 int extra_base; /* base index for extra_bits */
1933 int elems; /* max number of elements in the tree */
1934 int max_length; /* max bit length for the codes */
1937 local static_tree_desc static_l_desc =
1938 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1940 local static_tree_desc static_d_desc =
1941 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1943 local static_tree_desc static_bl_desc =
1944 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1946 /* ===========================================================================
1947 * Local (static) routines in this file.
1950 local void tr_static_init OF((void));
1951 local void init_block OF((deflate_state *s));
1952 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1953 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1954 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1955 local void build_tree OF((deflate_state *s, tree_desc *desc));
1956 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1957 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1958 local int build_bl_tree OF((deflate_state *s));
1959 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1961 local void compress_block OF((deflate_state *s, ct_data *ltree,
1963 local void set_data_type OF((deflate_state *s));
1964 local unsigned bi_reverse OF((unsigned value, int length));
1965 local void bi_windup OF((deflate_state *s));
1966 local void bi_flush OF((deflate_state *s));
1967 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1971 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1972 /* Send a code of the given tree. c and tree must not have side effects */
1974 #else /* DEBUG_ZLIB */
1975 # define send_code(s, c, tree) \
1976 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
1977 send_bits(s, tree[c].Code, tree[c].Len); }
1980 #define d_code(dist) \
1981 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1982 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1983 * must not have side effects. dist_code[256] and dist_code[257] are never
1987 /* ===========================================================================
1988 * Output a short LSB first on the stream.
1989 * IN assertion: there is enough room in pendingBuf.
1991 #define put_short(s, w) { \
1992 put_byte(s, (uch)((w) & 0xff)); \
1993 put_byte(s, (uch)((ush)(w) >> 8)); \
1996 /* ===========================================================================
1997 * Send a value on a given number of bits.
1998 * IN assertion: length <= 16 and value fits in length bits.
2001 * value: value to send
2002 * length: number of bits
2005 local void send_bits OF((deflate_state *s, int value, int length));
2008 send_bits(deflate_state *s, int value, int length)
2010 Tracevv((stderr," l %2d v %4x ", length, value));
2011 Assert(length > 0 && length <= 15, "invalid length");
2012 s->bits_sent += (ulg)length;
2014 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2015 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2016 * unused bits in value.
2018 if (s->bi_valid > (int)Buf_size - length) {
2019 s->bi_buf |= (value << s->bi_valid);
2020 put_short(s, s->bi_buf);
2021 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2022 s->bi_valid += length - Buf_size;
2024 s->bi_buf |= value << s->bi_valid;
2025 s->bi_valid += length;
2028 #else /* !DEBUG_ZLIB */
2030 #define send_bits(s, value, length) \
2031 { int len = length;\
2032 if (s->bi_valid > (int)Buf_size - len) {\
2034 s->bi_buf |= (val << s->bi_valid);\
2035 put_short(s, s->bi_buf);\
2036 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2037 s->bi_valid += len - Buf_size;\
2039 s->bi_buf |= (value) << s->bi_valid;\
2040 s->bi_valid += len;\
2043 #endif /* DEBUG_ZLIB */
2045 /* the arguments must not have side effects */
2047 /* ===========================================================================
2048 * Initialize the various 'constant' tables. In a multi-threaded environment,
2049 * this function may be called by two threads concurrently, but this is
2050 * harmless since both invocations do exactly the same thing.
2053 tr_static_init(void)
2055 static int static_init_done = 0;
2056 int n; /* iterates over tree elements */
2057 int bits; /* bit counter */
2058 int length; /* length value */
2059 int code; /* code value */
2060 int dist; /* distance index */
2061 ush bl_count[MAX_BITS+1];
2062 /* number of codes at each bit length for an optimal tree */
2064 if (static_init_done) return;
2066 /* Initialize the mapping length (0..255) -> length code (0..28) */
2068 for (code = 0; code < LENGTH_CODES-1; code++) {
2069 base_length[code] = length;
2070 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2071 length_code[length++] = (uch)code;
2074 Assert (length == 256, "tr_static_init: length != 256");
2075 /* Note that the length 255 (match length 258) can be represented
2076 * in two different ways: code 284 + 5 bits or code 285, so we
2077 * overwrite length_code[255] to use the best encoding:
2079 length_code[length-1] = (uch)code;
2081 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2083 for (code = 0 ; code < 16; code++) {
2084 base_dist[code] = dist;
2085 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2086 dist_code[dist++] = (uch)code;
2089 Assert (dist == 256, "tr_static_init: dist != 256");
2090 dist >>= 7; /* from now on, all distances are divided by 128 */
2091 for ( ; code < D_CODES; code++) {
2092 base_dist[code] = dist << 7;
2093 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2094 dist_code[256 + dist++] = (uch)code;
2097 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2099 /* Construct the codes of the static literal tree */
2100 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2102 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2103 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2104 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2105 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2106 /* Codes 286 and 287 do not exist, but we must include them in the
2107 * tree construction to get a canonical Huffman tree (longest code
2110 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2112 /* The static distance tree is trivial: */
2113 for (n = 0; n < D_CODES; n++) {
2114 static_dtree[n].Len = 5;
2115 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2117 static_init_done = 1;
2120 /* ===========================================================================
2121 * Initialize the tree data structures for a new zlib stream.
2124 _tr_init(deflate_state *s)
2128 s->compressed_len = 0L;
2130 s->l_desc.dyn_tree = s->dyn_ltree;
2131 s->l_desc.stat_desc = &static_l_desc;
2133 s->d_desc.dyn_tree = s->dyn_dtree;
2134 s->d_desc.stat_desc = &static_d_desc;
2136 s->bl_desc.dyn_tree = s->bl_tree;
2137 s->bl_desc.stat_desc = &static_bl_desc;
2141 s->last_eob_len = 8; /* enough lookahead for inflate */
2146 /* Initialize the first block of the first file: */
2150 /* ===========================================================================
2151 * Initialize a new block.
2154 init_block(deflate_state *s)
2156 int n; /* iterates over tree elements */
2158 /* Initialize the trees. */
2159 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2160 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2161 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2163 s->dyn_ltree[END_BLOCK].Freq = 1;
2164 s->opt_len = s->static_len = 0L;
2165 s->last_lit = s->matches = 0;
2169 /* Index within the heap array of least frequent node in the Huffman tree */
2172 /* ===========================================================================
2173 * Remove the smallest element from the heap and recreate the heap with
2174 * one less element. Updates heap and heap_len.
2176 #define pqremove(s, tree, top) \
2178 top = s->heap[SMALLEST]; \
2179 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2180 pqdownheap(s, tree, SMALLEST); \
2183 /* ===========================================================================
2184 * Compares to subtrees, using the tree depth as tie breaker when
2185 * the subtrees have equal frequency. This minimizes the worst case length.
2187 #define smaller(tree, n, m, depth) \
2188 (tree[n].Freq < tree[m].Freq || \
2189 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2191 /* ===========================================================================
2192 * Restore the heap property by moving down the tree starting at node k,
2193 * exchanging a node with the smallest of its two sons if necessary, stopping
2194 * when the heap property is re-established (each father smaller than its
2198 * tree: the tree to restore
2199 * k: node to move down
2202 pqdownheap(deflate_state *s, ct_data *tree, int k)
2205 int j = k << 1; /* left son of k */
2206 while (j <= s->heap_len) {
2207 /* Set j to the smallest of the two sons: */
2208 if (j < s->heap_len &&
2209 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2212 /* Exit if v is smaller than both sons */
2213 if (smaller(tree, v, s->heap[j], s->depth)) break;
2215 /* Exchange v with the smallest son */
2216 s->heap[k] = s->heap[j]; k = j;
2218 /* And continue down the tree, setting j to the left son of k */
2224 /* ===========================================================================
2225 * Compute the optimal bit lengths for a tree and update the total bit length
2226 * for the current block.
2227 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2228 * above are the tree nodes sorted by increasing frequency.
2229 * OUT assertions: the field len is set to the optimal bit length, the
2230 * array bl_count contains the frequencies for each bit length.
2231 * The length opt_len is updated; static_len is also updated if stree is
2235 * desc: the tree descriptor
2238 gen_bitlen(deflate_state *s, tree_desc *desc)
2240 ct_data *tree = desc->dyn_tree;
2241 int max_code = desc->max_code;
2242 ct_data *stree = desc->stat_desc->static_tree;
2243 intf *extra = desc->stat_desc->extra_bits;
2244 int base = desc->stat_desc->extra_base;
2245 int max_length = desc->stat_desc->max_length;
2246 int h; /* heap index */
2247 int n, m; /* iterate over the tree elements */
2248 int bits; /* bit length */
2249 int xbits; /* extra bits */
2250 ush f; /* frequency */
2251 int overflow = 0; /* number of elements with bit length too large */
2253 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2255 /* In a first pass, compute the optimal bit lengths (which may
2256 * overflow in the case of the bit length tree).
2258 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2260 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2262 bits = tree[tree[n].Dad].Len + 1;
2263 if (bits > max_length) bits = max_length, overflow++;
2264 tree[n].Len = (ush)bits;
2265 /* We overwrite tree[n].Dad which is no longer needed */
2267 if (n > max_code) continue; /* not a leaf node */
2269 s->bl_count[bits]++;
2271 if (n >= base) xbits = extra[n-base];
2273 s->opt_len += (ulg)f * (bits + xbits);
2274 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2276 if (overflow == 0) return;
2278 Trace((stderr,"\nbit length overflow\n"));
2279 /* This happens for example on obj2 and pic of the Calgary corpus */
2281 /* Find the first bit length which could increase: */
2283 bits = max_length-1;
2284 while (s->bl_count[bits] == 0) bits--;
2285 s->bl_count[bits]--; /* move one leaf down the tree */
2286 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2287 s->bl_count[max_length]--;
2288 /* The brother of the overflow item also moves one step up,
2289 * but this does not affect bl_count[max_length]
2292 } while (overflow > 0);
2294 /* Now recompute all bit lengths, scanning in increasing frequency.
2295 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2296 * lengths instead of fixing only the wrong ones. This idea is taken
2297 * from 'ar' written by Haruhiko Okumura.)
2299 for (bits = max_length; bits != 0; bits--) {
2300 n = s->bl_count[bits];
2303 if (m > max_code) continue;
2304 if (tree[m].Len != (unsigned) bits) {
2305 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2306 s->opt_len += ((long)bits - (long)tree[m].Len)
2307 *(long)tree[m].Freq;
2308 tree[m].Len = (ush)bits;
2315 /* ===========================================================================
2316 * Generate the codes for a given tree and bit counts (which need not be
2318 * IN assertion: the array bl_count contains the bit length statistics for
2319 * the given tree and the field len is set for all tree elements.
2320 * OUT assertion: the field code is set for all tree elements of non
2324 * tree: the tree to decorate
2325 * max_code: largest code with non zero frequency
2326 * bl_count: number of codes at each bit length
2329 gen_codes(ct_data *tree, int max_code, ushf *bl_count)
2331 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2332 ush code = 0; /* running code value */
2333 int bits; /* bit index */
2334 int n; /* code index */
2336 /* The distribution counts are first used to generate the code values
2337 * without bit reversal.
2339 for (bits = 1; bits <= MAX_BITS; bits++) {
2340 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2342 /* Check that the bit counts in bl_count are consistent. The last code
2345 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2346 "inconsistent bit counts");
2347 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2349 for (n = 0; n <= max_code; n++) {
2350 int len = tree[n].Len;
2351 if (len == 0) continue;
2352 /* Now reverse the bits */
2353 tree[n].Code = bi_reverse(next_code[len]++, len);
2355 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2356 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2360 /* ===========================================================================
2361 * Construct one Huffman tree and assigns the code bit strings and lengths.
2362 * Update the total bit length for the current block.
2363 * IN assertion: the field freq is set for all tree elements.
2364 * OUT assertions: the fields len and code are set to the optimal bit length
2365 * and corresponding code. The length opt_len is updated; static_len is
2366 * also updated if stree is not null. The field max_code is set.
2369 * desc: the tree descriptor
2372 build_tree(deflate_state *s, tree_desc *desc)
2374 ct_data *tree = desc->dyn_tree;
2375 ct_data *stree = desc->stat_desc->static_tree;
2376 int elems = desc->stat_desc->elems;
2377 int n, m; /* iterate over heap elements */
2378 int max_code = -1; /* largest code with non zero frequency */
2379 int node; /* new node being created */
2381 /* Construct the initial heap, with least frequent element in
2382 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2383 * heap[0] is not used.
2385 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2387 for (n = 0; n < elems; n++) {
2388 if (tree[n].Freq != 0) {
2389 s->heap[++(s->heap_len)] = max_code = n;
2396 /* The pkzip format requires that at least one distance code exists,
2397 * and that at least one bit should be sent even if there is only one
2398 * possible code. So to avoid special checks later on we force at least
2399 * two codes of non zero frequency.
2401 while (s->heap_len < 2) {
2402 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2403 tree[node].Freq = 1;
2405 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2406 /* node is 0 or 1 so it does not have extra bits */
2408 desc->max_code = max_code;
2410 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2411 * establish sub-heaps of increasing lengths:
2413 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2415 /* Construct the Huffman tree by repeatedly combining the least two
2418 node = elems; /* next internal node of the tree */
2420 pqremove(s, tree, n); /* n = node of least frequency */
2421 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2423 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2424 s->heap[--(s->heap_max)] = m;
2426 /* Create a new node father of n and m */
2427 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2428 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2429 tree[n].Dad = tree[m].Dad = (ush)node;
2431 if (tree == s->bl_tree) {
2432 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2433 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2436 /* and insert the new node in the heap */
2437 s->heap[SMALLEST] = node++;
2438 pqdownheap(s, tree, SMALLEST);
2440 } while (s->heap_len >= 2);
2442 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2444 /* At this point, the fields freq and dad are set. We can now
2445 * generate the bit lengths.
2447 gen_bitlen(s, (tree_desc *)desc);
2449 /* The field len is now set, we can generate the bit codes */
2450 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2453 /* ===========================================================================
2454 * Scan a literal or distance tree to determine the frequencies of the codes
2455 * in the bit length tree.
2458 * tree: the tree to be scanned
2459 * max_code: and its largest code of non zero frequency
2462 scan_tree (deflate_state *s, ct_data *tree, int max_code)
2464 int n; /* iterates over all tree elements */
2465 int prevlen = -1; /* last emitted length */
2466 int curlen; /* length of current code */
2467 int nextlen = tree[0].Len; /* length of next code */
2468 int count = 0; /* repeat count of the current code */
2469 int max_count = 7; /* max repeat count */
2470 int min_count = 4; /* min repeat count */
2472 if (nextlen == 0) max_count = 138, min_count = 3;
2473 tree[max_code+1].Len = (ush)0xffff; /* guard */
2475 for (n = 0; n <= max_code; n++) {
2476 curlen = nextlen; nextlen = tree[n+1].Len;
2477 if (++count < max_count && curlen == nextlen) {
2479 } else if (count < min_count) {
2480 s->bl_tree[curlen].Freq += count;
2481 } else if (curlen != 0) {
2482 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2483 s->bl_tree[REP_3_6].Freq++;
2484 } else if (count <= 10) {
2485 s->bl_tree[REPZ_3_10].Freq++;
2487 s->bl_tree[REPZ_11_138].Freq++;
2489 count = 0; prevlen = curlen;
2491 max_count = 138, min_count = 3;
2492 } else if (curlen == nextlen) {
2493 max_count = 6, min_count = 3;
2495 max_count = 7, min_count = 4;
2500 /* ===========================================================================
2501 * Send a literal or distance tree in compressed form, using the codes in
2505 * tree: the tree to be scanned
2506 * max_code: and its largest code of non zero frequency
2509 send_tree(deflate_state *s, ct_data *tree, int max_code)
2511 int n; /* iterates over all tree elements */
2512 int prevlen = -1; /* last emitted length */
2513 int curlen; /* length of current code */
2514 int nextlen = tree[0].Len; /* length of next code */
2515 int count = 0; /* repeat count of the current code */
2516 int max_count = 7; /* max repeat count */
2517 int min_count = 4; /* min repeat count */
2519 /* tree[max_code+1].Len = -1; */ /* guard already set */
2520 if (nextlen == 0) max_count = 138, min_count = 3;
2522 for (n = 0; n <= max_code; n++) {
2523 curlen = nextlen; nextlen = tree[n+1].Len;
2524 if (++count < max_count && curlen == nextlen) {
2526 } else if (count < min_count) {
2527 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2529 } else if (curlen != 0) {
2530 if (curlen != prevlen) {
2531 send_code(s, curlen, s->bl_tree); count--;
2533 Assert(count >= 3 && count <= 6, " 3_6?");
2534 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2536 } else if (count <= 10) {
2537 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2540 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2542 count = 0; prevlen = curlen;
2544 max_count = 138, min_count = 3;
2545 } else if (curlen == nextlen) {
2546 max_count = 6, min_count = 3;
2548 max_count = 7, min_count = 4;
2553 /* ===========================================================================
2554 * Construct the Huffman tree for the bit lengths and return the index in
2555 * bl_order of the last bit length code to send.
2558 build_bl_tree(deflate_state *s)
2560 int max_blindex; /* index of last bit length code of non zero freq */
2562 /* Determine the bit length frequencies for literal and distance trees */
2563 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2564 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2566 /* Build the bit length tree: */
2567 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2568 /* opt_len now includes the length of the tree representations, except
2569 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2572 /* Determine the number of bit length codes to send. The pkzip format
2573 * requires that at least 4 bit length codes be sent. (appnote.txt says
2574 * 3 but the actual value used is 4.)
2576 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2577 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2579 /* Update opt_len to include the bit length tree and counts */
2580 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2581 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2582 s->opt_len, s->static_len));
2587 /* ===========================================================================
2588 * Send the header for a block using dynamic Huffman trees: the counts, the
2589 * lengths of the bit length codes, the literal tree and the distance tree.
2590 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2593 * lcodes, dcodes, blcodes: number of codes for each tree
2596 send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes)
2598 int rank; /* index in bl_order */
2600 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2601 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2603 Tracev((stderr, "\nbl counts: "));
2604 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2605 send_bits(s, dcodes-1, 5);
2606 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2607 for (rank = 0; rank < blcodes; rank++) {
2608 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2609 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2611 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2613 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2614 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2616 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2617 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2620 /* ===========================================================================
2621 * Send a stored block
2625 * stored_len: length of input block
2626 * eof: true if this is the last block for a file
2629 _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
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.
2641 _tr_stored_type_only(deflate_state *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
2661 _tr_align(deflate_state *s)
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.
2687 * buf: input block, or NULL if too old
2688 * stored_len: length of input block
2689 * eof: true if this is the last block for a file
2692 _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
2694 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2695 int max_blindex = 0; /* index of last bit length code of non zero freq */
2697 /* Build the Huffman trees unless a stored block is forced */
2700 /* Check if the file is ascii or binary */
2701 if (s->data_type == Z_UNKNOWN) set_data_type(s);
2703 /* Construct the literal and distance trees */
2704 build_tree(s, (tree_desc *)(&(s->l_desc)));
2705 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2708 build_tree(s, (tree_desc *)(&(s->d_desc)));
2709 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2711 /* At this point, opt_len and static_len are the total bit lengths of
2712 * the compressed block data, excluding the tree representations.
2715 /* Build the bit length tree for the above two trees, and get the index
2716 * in bl_order of the last bit length code to send.
2718 max_blindex = build_bl_tree(s);
2720 /* Determine the best encoding. Compute first the block length in bytes*/
2721 opt_lenb = (s->opt_len+3+7)>>3;
2722 static_lenb = (s->static_len+3+7)>>3;
2724 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2725 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2728 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2731 Assert(buf != (char*)0, "lost buf");
2732 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
2735 /* If compression failed and this is the first and last block,
2736 * and if the .zip file can be seeked (to rewrite the local header),
2737 * the whole file is transformed into a stored file:
2739 #ifdef STORED_FILE_OK
2740 # ifdef FORCE_STORED_FILE
2741 if (eof && s->compressed_len == 0L) { /* force stored file */
2743 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
2745 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2746 if (buf == (charf*)0) error ("block vanished");
2748 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
2749 s->compressed_len = stored_len << 3;
2752 #endif /* STORED_FILE_OK */
2755 if (buf != (char*)0) { /* force stored block */
2757 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2758 /* 4: two words for the lengths */
2760 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2761 * Otherwise we can't have processed more than WSIZE input bytes since
2762 * the last block flush, because compression would have been
2763 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2764 * transform a block into a stored block.
2766 _tr_stored_block(s, buf, stored_len, eof);
2769 } else if (static_lenb >= 0) { /* force static trees */
2771 } else if (static_lenb == opt_lenb) {
2773 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2774 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2775 s->compressed_len += 3 + s->static_len;
2777 send_bits(s, (DYN_TREES<<1)+eof, 3);
2778 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2780 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2781 s->compressed_len += 3 + s->opt_len;
2783 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2788 s->compressed_len += 7; /* align on byte boundary */
2790 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2791 s->compressed_len-7*eof));
2793 return s->compressed_len >> 3;
2796 /* ===========================================================================
2797 * Save the match info and tally the frequency counts. Return true if
2798 * the current block must be flushed.
2801 * dist: distance of matched string
2802 * lc: match length-MIN_MATCH or unmatched char (if dist==0)
2805 _tr_tally(deflate_state *s, unsigned dist, unsigned lc)
2807 s->d_buf[s->last_lit] = (ush)dist;
2808 s->l_buf[s->last_lit++] = (uch)lc;
2810 /* lc is the unmatched char */
2811 s->dyn_ltree[lc].Freq++;
2814 /* Here, lc is the match length - MIN_MATCH */
2815 dist--; /* dist = match distance - 1 */
2816 Assert((ush)dist < (ush)MAX_DIST(s) &&
2817 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2818 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
2820 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2821 s->dyn_dtree[d_code(dist)].Freq++;
2824 /* Try to guess if it is profitable to stop the current block here */
2825 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2826 /* Compute an upper bound for the compressed length */
2827 ulg out_length = (ulg)s->last_lit*8L;
2828 ulg in_length = (ulg)((long)s->strstart - s->block_start);
2830 for (dcode = 0; dcode < D_CODES; dcode++) {
2831 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2832 (5L+extra_dbits[dcode]);
2835 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2836 s->last_lit, in_length, out_length,
2837 100L - out_length*100L/in_length));
2838 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2840 return (s->last_lit == s->lit_bufsize-1);
2841 /* We avoid equality with lit_bufsize because of wraparound at 64K
2842 * on 16 bit machines and because stored blocks are restricted to
2847 /* ===========================================================================
2848 * Send the block data compressed using the given Huffman trees
2851 * ltree: literal tree
2852 * dtree: distance tree
2855 compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree)
2857 unsigned dist; /* distance of matched string */
2858 int lc; /* match length or unmatched char (if dist == 0) */
2859 unsigned lx = 0; /* running index in l_buf */
2860 unsigned code; /* the code to send */
2861 int extra; /* number of extra bits to send */
2863 if (s->last_lit != 0) do {
2864 dist = s->d_buf[lx];
2865 lc = s->l_buf[lx++];
2867 send_code(s, lc, ltree); /* send a literal byte */
2868 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2870 /* Here, lc is the match length - MIN_MATCH */
2871 code = length_code[lc];
2872 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2873 extra = extra_lbits[code];
2875 lc -= base_length[code];
2876 send_bits(s, lc, extra); /* send the extra length bits */
2878 dist--; /* dist is now the match distance - 1 */
2879 code = d_code(dist);
2880 Assert (code < D_CODES, "bad d_code");
2882 send_code(s, code, dtree); /* send the distance code */
2883 extra = extra_dbits[code];
2885 dist -= base_dist[code];
2886 send_bits(s, dist, extra); /* send the extra distance bits */
2888 } /* literal or match pair ? */
2890 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2891 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2893 } while (lx < s->last_lit);
2895 send_code(s, END_BLOCK, ltree);
2896 s->last_eob_len = ltree[END_BLOCK].Len;
2899 /* ===========================================================================
2900 * Set the data type to ASCII or BINARY, using a crude approximation:
2901 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2902 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2903 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2906 set_data_type(deflate_state *s)
2909 unsigned ascii_freq = 0;
2910 unsigned bin_freq = 0;
2911 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2912 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2913 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2914 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
2917 /* ===========================================================================
2918 * Reverse the first len bits of a code, using straightforward code (a faster
2919 * method would use a table)
2920 * IN assertion: 1 <= len <= 15
2923 * code: the value to invert
2924 * len: its bit length
2927 bi_reverse(unsigned code, int len)
2932 code >>= 1, res <<= 1;
2933 } while (--len > 0);
2937 /* ===========================================================================
2938 * Flush the bit buffer, keeping at most 7 bits in it.
2941 bi_flush(deflate_state *s)
2943 if (s->bi_valid == 16) {
2944 put_short(s, s->bi_buf);
2947 } else if (s->bi_valid >= 8) {
2948 put_byte(s, (Byte)s->bi_buf);
2954 /* ===========================================================================
2955 * Flush the bit buffer and align the output on a byte boundary
2958 bi_windup(deflate_state *s)
2960 if (s->bi_valid > 8) {
2961 put_short(s, s->bi_buf);
2962 } else if (s->bi_valid > 0) {
2963 put_byte(s, (Byte)s->bi_buf);
2968 s->bits_sent = (s->bits_sent+7) & ~7;
2972 /* ===========================================================================
2973 * Copy a stored block, storing first the length and its
2974 * one's complement if requested.
2977 * buf: the input data
2979 * header: true if block header must be written
2982 copy_block(deflate_state *s, charf *buf, unsigned len, int header)
2984 bi_windup(s); /* align on byte boundary */
2985 s->last_eob_len = 8; /* enough lookahead for inflate */
2988 put_short(s, (ush)len);
2989 put_short(s, (ush)~len);
2991 s->bits_sent += 2*16;
2995 s->bits_sent += (ulg)len<<3;
2997 /* bundle up the put_byte(s, *buf++) calls */
2998 zmemcpy(&s->pending_buf[s->pending], buf, len);
3004 /* inflate.c -- zlib interface to inflate modules
3005 * Copyright (C) 1995-1996 Mark Adler
3006 * For conditions of distribution and use, see copyright notice in zlib.h
3009 /* #include "zutil.h" */
3011 /* +++ infblock.h */
3012 /* infblock.h -- header to use infblock.c
3013 * Copyright (C) 1995-1996 Mark Adler
3014 * For conditions of distribution and use, see copyright notice in zlib.h
3017 /* WARNING: this file should *not* be used by applications. It is
3018 part of the implementation of the compression library and is
3019 subject to change. Applications should only use zlib.h.
3022 struct inflate_blocks_state;
3023 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3025 extern inflate_blocks_statef * inflate_blocks_new OF((
3027 check_func c, /* check function */
3028 uInt w)); /* window size */
3030 extern int inflate_blocks OF((
3031 inflate_blocks_statef *,
3033 int)); /* initial return code */
3035 extern void inflate_blocks_reset OF((
3036 inflate_blocks_statef *,
3038 uLongf *)); /* check value on output */
3040 extern int inflate_blocks_free OF((
3041 inflate_blocks_statef *,
3043 uLongf *)); /* check value on output */
3045 extern void inflate_set_dictionary OF((
3046 inflate_blocks_statef *s,
3047 const Bytef *d, /* dictionary */
3048 uInt n)); /* dictionary length */
3050 extern int inflate_addhistory OF((
3051 inflate_blocks_statef *,
3054 extern int inflate_packet_flush OF((
3055 inflate_blocks_statef *));
3056 /* --- infblock.h */
3058 #ifndef NO_DUMMY_DECL
3059 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3062 /* inflate private state */
3063 struct internal_state {
3067 METHOD, /* waiting for method byte */
3068 FLAG, /* waiting for flag byte */
3069 DICT4, /* four dictionary check bytes to go */
3070 DICT3, /* three dictionary check bytes to go */
3071 DICT2, /* two dictionary check bytes to go */
3072 DICT1, /* one dictionary check byte to go */
3073 DICT0, /* waiting for inflateSetDictionary */
3074 BLOCKS, /* decompressing blocks */
3075 CHECK4, /* four check bytes to go */
3076 CHECK3, /* three check bytes to go */
3077 CHECK2, /* two check bytes to go */
3078 CHECK1, /* one check byte to go */
3079 DONE, /* finished check, done */
3080 BAD} /* got an error--stay here */
3081 mode; /* current inflate mode */
3083 /* mode dependent information */
3085 uInt method; /* if FLAGS, method byte */
3087 uLong was; /* computed check value */
3088 uLong need; /* stream check value */
3089 } check; /* if CHECK, check values to compare */
3090 uInt marker; /* if BAD, inflateSync's marker bytes count */
3091 } sub; /* submode */
3093 /* mode independent information */
3094 int nowrap; /* flag for no wrapper */
3095 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3096 inflate_blocks_statef
3097 *blocks; /* current inflate_blocks state */
3103 inflateReset(z_streamp z)
3107 if (z == Z_NULL || z->state == Z_NULL)
3108 return Z_STREAM_ERROR;
3109 z->total_in = z->total_out = 0;
3111 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3112 inflate_blocks_reset(z->state->blocks, z, &c);
3113 Trace((stderr, "inflate: reset\n"));
3119 inflateEnd(z_streamp z)
3123 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3124 return Z_STREAM_ERROR;
3125 if (z->state->blocks != Z_NULL)
3126 inflate_blocks_free(z->state->blocks, z, &c);
3129 Trace((stderr, "inflate: end\n"));
3135 inflateInit2_(z_streamp z, int w, const char *version, int stream_size)
3137 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3138 stream_size != sizeof(z_stream))
3139 return Z_VERSION_ERROR;
3141 /* initialize state */
3143 return Z_STREAM_ERROR;
3146 if (z->zalloc == Z_NULL)
3148 z->zalloc = zcalloc;
3149 z->opaque = (voidpf)0;
3151 if (z->zfree == Z_NULL) z->zfree = zcfree;
3153 if ((z->state = (struct internal_state FAR *)
3154 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3156 z->state->blocks = Z_NULL;
3158 /* handle undocumented nowrap option (no zlib header or check) */
3159 z->state->nowrap = 0;
3163 z->state->nowrap = 1;
3166 /* set window size */
3167 if (w < 8 || w > 15)
3170 return Z_STREAM_ERROR;
3172 z->state->wbits = (uInt)w;
3174 /* create inflate_blocks state */
3175 if ((z->state->blocks =
3176 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3182 Trace((stderr, "inflate: allocated\n"));
3191 inflateInit_(z_streamp z, const char *version, int stream_size)
3193 return inflateInit2_(z, DEF_WBITS, version, stream_size);
3197 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3198 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3201 inflate(z_streamp z, int f)
3206 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0)
3207 return Z_STREAM_ERROR;
3209 while (1) switch (z->state->mode)
3213 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3215 z->state->mode = BAD;
3216 z->msg = (char*)"unknown compression method";
3217 z->state->sub.marker = 5; /* can't try inflateSync */
3220 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3222 z->state->mode = BAD;
3223 z->msg = (char*)"invalid window size";
3224 z->state->sub.marker = 5; /* can't try inflateSync */
3227 z->state->mode = FLAG;
3231 if (((z->state->sub.method << 8) + b) % 31)
3233 z->state->mode = BAD;
3234 z->msg = (char*)"incorrect header check";
3235 z->state->sub.marker = 5; /* can't try inflateSync */
3238 Trace((stderr, "inflate: zlib header ok\n"));
3239 if (!(b & PRESET_DICT))
3241 z->state->mode = BLOCKS;
3244 z->state->mode = DICT4;
3247 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3248 z->state->mode = DICT3;
3251 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3252 z->state->mode = DICT2;
3255 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3256 z->state->mode = DICT1;
3259 z->state->sub.check.need += (uLong)NEXTBYTE;
3260 z->adler = z->state->sub.check.need;
3261 z->state->mode = DICT0;
3264 z->state->mode = BAD;
3265 z->msg = (char*)"need dictionary";
3266 z->state->sub.marker = 0; /* can try inflateSync */
3267 return Z_STREAM_ERROR;
3269 r = inflate_blocks(z->state->blocks, z, r);
3270 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3271 r = inflate_packet_flush(z->state->blocks);
3272 if (r == Z_DATA_ERROR)
3274 z->state->mode = BAD;
3275 z->state->sub.marker = 0; /* can try inflateSync */
3278 if (r != Z_STREAM_END)
3281 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3282 if (z->state->nowrap)
3284 z->state->mode = DONE;
3287 z->state->mode = CHECK4;
3290 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3291 z->state->mode = CHECK3;
3294 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3295 z->state->mode = CHECK2;
3298 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3299 z->state->mode = CHECK1;
3302 z->state->sub.check.need += (uLong)NEXTBYTE;
3304 if (z->state->sub.check.was != z->state->sub.check.need)
3306 z->state->mode = BAD;
3307 z->msg = (char*)"incorrect data check";
3308 z->state->sub.marker = 5; /* can't try inflateSync */
3311 Trace((stderr, "inflate: zlib check ok\n"));
3312 z->state->mode = DONE;
3314 return Z_STREAM_END;
3316 return Z_DATA_ERROR;
3318 return Z_STREAM_ERROR;
3322 if (f != Z_PACKET_FLUSH)
3324 z->state->mode = BAD;
3325 z->msg = (char *)"need more for packet flush";
3326 z->state->sub.marker = 0; /* can try inflateSync */
3327 return Z_DATA_ERROR;
3332 inflateSetDictionary(z_streamp z, const Bytef *dictionary, uInt dictLength)
3334 uInt length = dictLength;
3336 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3337 return Z_STREAM_ERROR;
3339 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3342 if (length >= ((uInt)1<<z->state->wbits))
3344 length = (1<<z->state->wbits)-1;
3345 dictionary += dictLength - length;
3347 inflate_set_dictionary(z->state->blocks, dictionary, length);
3348 z->state->mode = BLOCKS;
3353 * This subroutine adds the data at next_in/avail_in to the output history
3354 * without performing any output. The output buffer must be "caught up";
3355 * i.e. no pending output (hence s->read equals s->write), and the state must
3356 * be BLOCKS (i.e. we should be willing to see the start of a series of
3357 * BLOCKS). On exit, the output will also be caught up, and the checksum
3358 * will have been updated if need be.
3362 inflateIncomp(z_stream *z)
3364 if (z->state->mode != BLOCKS)
3365 return Z_DATA_ERROR;
3366 return inflate_addhistory(z->state->blocks, z);
3371 inflateSync(z_streamp z)
3373 uInt n; /* number of bytes to look at */
3374 Bytef *p; /* pointer to bytes */
3375 uInt m; /* number of marker bytes found in a row */
3376 uLong r, w; /* temporaries to save total_in and total_out */
3379 if (z == Z_NULL || z->state == Z_NULL)
3380 return Z_STREAM_ERROR;
3381 if (z->state->mode != BAD)
3383 z->state->mode = BAD;
3384 z->state->sub.marker = 0;
3386 if ((n = z->avail_in) == 0)
3389 m = z->state->sub.marker;
3394 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3404 z->total_in += p - z->next_in;
3407 z->state->sub.marker = m;
3409 /* return no joy or set up to restart on a new block */
3411 return Z_DATA_ERROR;
3412 r = z->total_in; w = z->total_out;
3414 z->total_in = r; z->total_out = w;
3415 z->state->mode = BLOCKS;
3423 /* +++ infblock.c */
3424 /* infblock.c -- interpret and process block types to last block
3425 * Copyright (C) 1995-1996 Mark Adler
3426 * For conditions of distribution and use, see copyright notice in zlib.h
3429 /* #include "zutil.h" */
3430 /* #include "infblock.h" */
3432 /* +++ inftrees.h */
3433 /* inftrees.h -- header to use inftrees.c
3434 * Copyright (C) 1995-1996 Mark Adler
3435 * For conditions of distribution and use, see copyright notice in zlib.h
3438 /* WARNING: this file should *not* be used by applications. It is
3439 part of the implementation of the compression library and is
3440 subject to change. Applications should only use zlib.h.
3443 /* Huffman code lookup table entry--this entry is four bytes for machines
3444 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3446 typedef struct inflate_huft_s FAR inflate_huft;
3448 struct inflate_huft_s {
3451 Byte Exop; /* number of extra bits or operation */
3452 Byte Bits; /* number of bits in this code or subcode */
3454 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
3455 } word; /* 16-bit, 8 bytes for 32-bit machines) */
3457 uInt Base; /* literal, length base, or distance base */
3458 inflate_huft *Next; /* pointer to next level of table */
3463 extern uInt inflate_hufts;
3466 extern int inflate_trees_bits OF((
3467 uIntf *, /* 19 code lengths */
3468 uIntf *, /* bits tree desired/actual depth */
3469 inflate_huft * FAR *, /* bits tree result */
3470 z_streamp )); /* for zalloc, zfree functions */
3472 extern int inflate_trees_dynamic OF((
3473 uInt, /* number of literal/length codes */
3474 uInt, /* number of distance codes */
3475 uIntf *, /* that many (total) code lengths */
3476 uIntf *, /* literal desired/actual bit depth */
3477 uIntf *, /* distance desired/actual bit depth */
3478 inflate_huft * FAR *, /* literal/length tree result */
3479 inflate_huft * FAR *, /* distance tree result */
3480 z_streamp )); /* for zalloc, zfree functions */
3482 extern int inflate_trees_fixed OF((
3483 uIntf *, /* literal desired/actual bit depth */
3484 uIntf *, /* distance desired/actual bit depth */
3485 inflate_huft * FAR *, /* literal/length tree result */
3486 inflate_huft * FAR *)); /* distance tree result */
3488 extern int inflate_trees_free OF((
3489 inflate_huft *, /* tables to free */
3490 z_streamp )); /* for zfree function */
3492 /* --- inftrees.h */
3494 /* +++ infcodes.h */
3495 /* infcodes.h -- header to use infcodes.c
3496 * Copyright (C) 1995-1996 Mark Adler
3497 * For conditions of distribution and use, see copyright notice in zlib.h
3500 /* WARNING: this file should *not* be used by applications. It is
3501 part of the implementation of the compression library and is
3502 subject to change. Applications should only use zlib.h.
3505 struct inflate_codes_state;
3506 typedef struct inflate_codes_state FAR inflate_codes_statef;
3508 extern inflate_codes_statef *inflate_codes_new OF((
3510 inflate_huft *, inflate_huft *,
3513 extern int inflate_codes OF((
3514 inflate_blocks_statef *,
3518 extern void inflate_codes_free OF((
3519 inflate_codes_statef *,
3522 /* --- infcodes.h */
3525 /* infutil.h -- types and macros common to blocks and codes
3526 * Copyright (C) 1995-1996 Mark Adler
3527 * For conditions of distribution and use, see copyright notice in zlib.h
3530 /* WARNING: this file should *not* be used by applications. It is
3531 part of the implementation of the compression library and is
3532 subject to change. Applications should only use zlib.h.
3539 TYPE, /* get type bits (3, including end bit) */
3540 LENS, /* get lengths for stored */
3541 STORED, /* processing stored block */
3542 TABLE, /* get table lengths */
3543 BTREE, /* get bit lengths tree for a dynamic block */
3544 DTREE, /* get length, distance trees for a dynamic block */
3545 CODES, /* processing fixed or dynamic block */
3546 DRY, /* output remaining window bytes */
3547 DONEB, /* finished last block, done */
3548 BADB} /* got a data error--stuck here */
3551 /* inflate blocks semi-private state */
3552 struct inflate_blocks_state {
3555 inflate_block_mode mode; /* current inflate_block mode */
3557 /* mode dependent information */
3559 uInt left; /* if STORED, bytes left to copy */
3561 uInt table; /* table lengths (14 bits) */
3562 uInt index; /* index into blens (or border) */
3563 uIntf *blens; /* bit lengths of codes */
3564 uInt bb; /* bit length tree depth */
3565 inflate_huft *tb; /* bit length decoding tree */
3566 } trees; /* if DTREE, decoding info for trees */
3569 inflate_huft *td; /* trees to free */
3570 inflate_codes_statef
3572 } decode; /* if CODES, current state */
3573 } sub; /* submode */
3574 uInt last; /* true if this block is the last block */
3576 /* mode independent information */
3577 uInt bitk; /* bits in bit buffer */
3578 uLong bitb; /* bit buffer */
3579 Bytef *window; /* sliding window */
3580 Bytef *end; /* one byte after sliding window */
3581 Bytef *read; /* window read pointer */
3582 Bytef *write; /* window write pointer */
3583 check_func checkfn; /* check function */
3584 uLong check; /* check on output */
3589 /* defines for inflate input/output */
3590 /* update pointers and return */
3591 #define UPDBITS {s->bitb=b;s->bitk=k;}
3592 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3593 #define UPDOUT {s->write=q;}
3594 #define UPDATE {UPDBITS UPDIN UPDOUT}
3595 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3596 /* get bytes and bits */
3597 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3598 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3599 #define NEXTBYTE (n--,*p++)
3600 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3601 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3603 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3604 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3605 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3606 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3607 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;}
3608 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3609 /* load local pointers */
3610 #define LOAD {LOADIN LOADOUT}
3612 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3613 extern uInt inflate_mask[17];
3615 /* copy as much as possible from the sliding window to the output area */
3616 extern int inflate_flush OF((
3617 inflate_blocks_statef *,
3621 #ifndef NO_DUMMY_DECL
3622 struct internal_state {int dummy;}; /* for buggy compilers */
3628 #ifndef NO_DUMMY_DECL
3629 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3632 /* Table for deflate from PKZIP's appnote.txt. */
3633 local const uInt border[] = { /* Order of the bit length code lengths */
3634 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3637 Notes beyond the 1.93a appnote.txt:
3639 1. Distance pointers never point before the beginning of the output
3641 2. Distance pointers can point back across blocks, up to 32k away.
3642 3. There is an implied maximum of 7 bits for the bit length table and
3643 15 bits for the actual data.
3644 4. If only one code exists, then it is encoded using one bit. (Zero
3645 would be more efficient, but perhaps a little confusing.) If two
3646 codes exist, they are coded using one bit each (0 and 1).
3647 5. There is no way of sending zero distance codes--a dummy must be
3648 sent if there are none. (History: a pre 2.0 version of PKZIP would
3649 store blocks with no distance codes, but this was discovered to be
3650 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3651 zero distance codes, which is sent as one code of zero bits in
3653 6. There are up to 286 literal/length codes. Code 256 represents the
3654 end-of-block. Note however that the static length tree defines
3655 288 codes just to fill out the Huffman codes. Codes 286 and 287
3656 cannot be used though, since there is no length base or extra bits
3657 defined for them. Similarily, there are up to 30 distance codes.
3658 However, static trees define 32 codes (all 5 bits) to fill out the
3659 Huffman codes, but the last two had better not show up in the data.
3660 7. Unzip can check dynamic Huffman blocks for complete code sets.
3661 The exception is that a single code would not be complete (see #4).
3662 8. The five bits following the block type is really the number of
3663 literal codes sent minus 257.
3664 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3665 (1+6+6). Therefore, to output three times the length, you output
3666 three codes (1+1+1), whereas to output four times the same length,
3667 you only need two codes (1+3). Hmm.
3668 10. In the tree reconstruction algorithm, Code = Code + Increment
3669 only if BitLength(i) is not zero. (Pretty obvious.)
3670 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3671 12. Note: length code 284 can represent 227-258, but length code 285
3672 really is 258. The last length deserves its own, short code
3673 since it gets used a lot in very redundant files. The length
3674 258 is special since 258 - 3 (the min match length) is 255.
3675 13. The literal/length and distance code bit lengths are read as a
3676 single stream of lengths. It is possible (and advantageous) for
3677 a repeat code (16, 17, or 18) to go across the boundary between
3678 the two sets of lengths.
3683 inflate_blocks_reset(inflate_blocks_statef *s, z_streamp z, uLongf *c)
3685 if (s->checkfn != Z_NULL)
3687 if (s->mode == BTREE || s->mode == DTREE)
3688 ZFREE(z, s->sub.trees.blens);
3689 if (s->mode == CODES)
3691 inflate_codes_free(s->sub.decode.codes, z);
3692 inflate_trees_free(s->sub.decode.td, z);
3693 inflate_trees_free(s->sub.decode.tl, z);
3698 s->read = s->write = s->window;
3699 if (s->checkfn != Z_NULL)
3700 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
3701 Trace((stderr, "inflate: blocks reset\n"));
3705 inflate_blocks_statef *
3706 inflate_blocks_new(z_streamp z, check_func c, uInt w)
3708 inflate_blocks_statef *s;
3710 if ((s = (inflate_blocks_statef *)ZALLOC
3711 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3713 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3718 s->end = s->window + w;
3721 Trace((stderr, "inflate: blocks allocated\n"));
3722 inflate_blocks_reset(s, z, &s->check);
3728 extern uInt inflate_hufts;
3732 inflate_blocks(inflate_blocks_statef *s, z_streamp z, int r)
3734 uInt t; /* temporary storage */
3735 uLong b; /* bit buffer */
3736 uInt k; /* bits in bit buffer */
3737 Bytef *p; /* input data pointer */
3738 uInt n; /* bytes available there */
3739 Bytef *q; /* output window write pointer */
3740 uInt m; /* bytes to end of window or read pointer */
3742 /* copy input/output information to locals (UPDATE macro restores) */
3745 /* process input based on current state */
3746 while (1) switch (s->mode)
3754 case 0: /* stored */
3755 Trace((stderr, "inflate: stored block%s\n",
3756 s->last ? " (last)" : ""));
3758 t = k & 7; /* go to byte boundary */
3760 s->mode = LENS; /* get length of stored block */
3763 Trace((stderr, "inflate: fixed codes block%s\n",
3764 s->last ? " (last)" : ""));
3767 inflate_huft *tl, *td;
3769 inflate_trees_fixed(&bl, &bd, &tl, &td);
3770 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3771 if (s->sub.decode.codes == Z_NULL)
3776 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3777 s->sub.decode.td = Z_NULL;
3782 case 2: /* dynamic */
3783 Trace((stderr, "inflate: dynamic codes block%s\n",
3784 s->last ? " (last)" : ""));
3788 case 3: /* illegal */
3791 z->msg = (char*)"invalid block type";
3798 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
3801 z->msg = (char*)"invalid stored block lengths";
3805 s->sub.left = (uInt)b & 0xffff;
3806 b = k = 0; /* dump bits */
3807 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3808 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
3820 if ((s->sub.left -= t) != 0)
3822 Tracev((stderr, "inflate: stored end, %lu total out\n",
3823 z->total_out + (q >= s->read ? q - s->read :
3824 (s->end - s->read) + (q - s->window))));
3825 s->mode = s->last ? DRY : TYPE;
3829 s->sub.trees.table = t = (uInt)b & 0x3fff;
3830 #ifndef PKZIP_BUG_WORKAROUND
3831 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3834 z->msg = (char*)"too many length or distance symbols";
3839 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3842 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3848 s->sub.trees.index = 0;
3849 Tracev((stderr, "inflate: table sizes ok\n"));
3852 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3855 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3858 while (s->sub.trees.index < 19)
3859 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3860 s->sub.trees.bb = 7;
3861 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3862 &s->sub.trees.tb, z);
3866 if (r == Z_DATA_ERROR) {
3867 ZFREE(z, s->sub.trees.blens);
3872 s->sub.trees.index = 0;
3873 Tracev((stderr, "inflate: bits tree ok\n"));
3876 while (t = s->sub.trees.table,
3877 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3882 t = s->sub.trees.bb;
3884 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3885 t = h->word.what.Bits;
3890 s->sub.trees.blens[s->sub.trees.index++] = c;
3892 else /* c == 16..18 */
3894 i = c == 18 ? 7 : c - 14;
3895 j = c == 18 ? 11 : 3;
3898 j += (uInt)b & inflate_mask[i];
3900 i = s->sub.trees.index;
3901 t = s->sub.trees.table;
3902 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3905 inflate_trees_free(s->sub.trees.tb, z);
3906 ZFREE(z, s->sub.trees.blens);
3908 z->msg = (char*)"invalid bit length repeat";
3912 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3914 s->sub.trees.blens[i++] = c;
3916 s->sub.trees.index = i;
3919 inflate_trees_free(s->sub.trees.tb, z);
3920 s->sub.trees.tb = Z_NULL;
3923 inflate_huft *tl, *td;
3924 inflate_codes_statef *c;
3926 bl = 9; /* must be <= 9 for lookahead assumptions */
3927 bd = 6; /* must be <= 9 for lookahead assumptions */
3928 t = s->sub.trees.table;
3932 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3933 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3936 if (t == (uInt)Z_DATA_ERROR) {
3937 ZFREE(z, s->sub.trees.blens);
3943 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n",
3944 inflate_hufts, sizeof(inflate_huft)));
3945 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3947 inflate_trees_free(td, z);
3948 inflate_trees_free(tl, z);
3953 * this ZFREE must occur *BEFORE* we mess with sub.decode, because
3954 * sub.trees is union'd with sub.decode.
3956 ZFREE(z, s->sub.trees.blens);
3957 s->sub.decode.codes = c;
3958 s->sub.decode.tl = tl;
3959 s->sub.decode.td = td;
3964 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3965 return inflate_flush(s, z, r);
3967 inflate_codes_free(s->sub.decode.codes, z);
3968 inflate_trees_free(s->sub.decode.td, z);
3969 inflate_trees_free(s->sub.decode.tl, z);
3971 Tracev((stderr, "inflate: codes end, %lu total out\n",
3972 z->total_out + (q >= s->read ? q - s->read :
3973 (s->end - s->read) + (q - s->window))));
3979 if (k > 7) /* return unused byte, if any */
3981 Assert(k < 16, "inflate_codes grabbed too many bytes")
3984 p--; /* can always return one */
3989 if (s->read != s->write)
4006 inflate_blocks_free(inflate_blocks_statef *s, z_streamp z, uLongf *c)
4008 inflate_blocks_reset(s, z, c);
4009 ZFREE(z, s->window);
4011 Trace((stderr, "inflate: blocks freed\n"));
4017 inflate_set_dictionary(inflate_blocks_statef *s, const Bytef *d, uInt n)
4019 zmemcpy((charf *)s->window, d, n);
4020 s->read = s->write = s->window + n;
4024 * This subroutine adds the data at next_in/avail_in to the output history
4025 * without performing any output. The output buffer must be "caught up";
4026 * i.e. no pending output (hence s->read equals s->write), and the state must
4027 * be BLOCKS (i.e. we should be willing to see the start of a series of
4028 * BLOCKS). On exit, the output will also be caught up, and the checksum
4029 * will have been updated if need be.
4032 inflate_addhistory(inflate_blocks_statef *s, z_stream *z)
4034 uLong b; /* bit buffer */ /* NOT USED HERE */
4035 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
4036 uInt t; /* temporary storage */
4037 Bytef *p; /* input data pointer */
4038 uInt n; /* bytes available there */
4039 Bytef *q; /* output window write pointer */
4040 uInt m; /* bytes to end of window or read pointer */
4042 if (s->read != s->write)
4043 return Z_STREAM_ERROR;
4044 if (s->mode != TYPE)
4045 return Z_DATA_ERROR;
4047 /* we're ready to rock */
4049 /* while there is input ready, copy to output buffer, moving
4050 * pointers as needed.
4053 t = n; /* how many to do */
4054 /* is there room until end of buffer? */
4056 /* update check information */
4057 if (s->checkfn != Z_NULL)
4058 s->check = (*s->checkfn)(s->check, q, t);
4064 s->read = q; /* drag read pointer forward */
4065 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */
4067 s->read = q = s->window;
4077 * At the end of a Deflate-compressed PPP packet, we expect to have seen
4078 * a `stored' block type value but not the (zero) length bytes.
4081 inflate_packet_flush(inflate_blocks_statef *s)
4083 if (s->mode != LENS)
4084 return Z_DATA_ERROR;
4088 /* --- infblock.c */
4090 /* +++ inftrees.c */
4091 /* inftrees.c -- generate Huffman trees for efficient decoding
4092 * Copyright (C) 1995-1996 Mark Adler
4093 * For conditions of distribution and use, see copyright notice in zlib.h
4096 /* #include "zutil.h" */
4097 /* #include "inftrees.h" */
4099 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler ";
4101 If you use the zlib library in a product, an acknowledgment is welcome
4102 in the documentation of your product. If for some reason you cannot
4103 include such an acknowledgment, I would appreciate that you keep this
4104 copyright string in the executable of your product.
4107 #ifndef NO_DUMMY_DECL
4108 struct internal_state {int dummy;}; /* for buggy compilers */
4111 /* simplify the use of the inflate_huft type with some defines */
4112 #define base more.Base
4113 #define next more.Next
4114 #define exop word.what.Exop
4115 #define bits word.what.Bits
4118 local int huft_build OF((
4119 uIntf *, /* code lengths in bits */
4120 uInt, /* number of codes */
4121 uInt, /* number of "simple" codes */
4122 const uIntf *, /* list of base values for non-simple codes */
4123 const uIntf *, /* list of extra bits for non-simple codes */
4124 inflate_huft * FAR*,/* result: starting table */
4125 uIntf *, /* maximum lookup bits (returns actual) */
4126 z_streamp )); /* for zalloc function */
4128 local voidpf falloc OF((
4129 voidpf, /* opaque pointer (not used) */
4130 uInt, /* number of items */
4131 uInt)); /* size of item */
4133 /* Tables for deflate from PKZIP's appnote.txt. */
4134 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4135 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4136 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4137 /* see note #13 above about 258 */
4138 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4139 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4140 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4141 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4142 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4143 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4144 8193, 12289, 16385, 24577};
4145 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4146 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4147 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4151 Huffman code decoding is performed using a multi-level table lookup.
4152 The fastest way to decode is to simply build a lookup table whose
4153 size is determined by the longest code. However, the time it takes
4154 to build this table can also be a factor if the data being decoded
4155 is not very long. The most common codes are necessarily the
4156 shortest codes, so those codes dominate the decoding time, and hence
4157 the speed. The idea is you can have a shorter table that decodes the
4158 shorter, more probable codes, and then point to subsidiary tables for
4159 the longer codes. The time it costs to decode the longer codes is
4160 then traded against the time it takes to make longer tables.
4162 This results of this trade are in the variables lbits and dbits
4163 below. lbits is the number of bits the first level table for literal/
4164 length codes can decode in one step, and dbits is the same thing for
4165 the distance codes. Subsequent tables are also less than or equal to
4166 those sizes. These values may be adjusted either when all of the
4167 codes are shorter than that, in which case the longest code length in
4168 bits is used, or when the shortest code is *longer* than the requested
4169 table size, in which case the length of the shortest code in bits is
4172 There are two different values for the two tables, since they code a
4173 different number of possibilities each. The literal/length table
4174 codes 286 possible values, or in a flat code, a little over eight
4175 bits. The distance table codes 30 possible values, or a little less
4176 than five bits, flat. The optimum values for speed end up being
4177 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4178 The optimum values may differ though from machine to machine, and
4179 possibly even between compilers. Your mileage may vary.
4183 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4184 #define BMAX 15 /* maximum bit length of any code */
4185 #define N_MAX 288 /* maximum number of codes in any set */
4193 * b: code lengths in bits (all assumed <= BMAX)
4194 * n: number of codes (assumed <= N_MAX)
4195 * s: number of simple-valued codes (0..s-1)
4196 * d: list of base values for non-simple codes
4197 * e: list of extra bits for non-simple codes
4198 * t: result: starting table
4199 * m: maximum lookup bits, returns actual
4200 * zs: for zalloc function
4202 * Given a list of code lengths and a maximum table size, make a set of
4203 * tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
4204 * if the given code set is incomplete (the tables are still built in this
4205 * case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of
4206 * lengths), or Z_MEM_ERROR if not enough memory.
4209 huft_build(uIntf *b, uInt n, uInt s, const uIntf *d, const uIntf *e,
4210 inflate_huft * FAR *t, uIntf *m, z_streamp zs)
4213 uInt a; /* counter for codes of length k */
4214 uInt c[BMAX+1]; /* bit length count table */
4215 uInt f; /* i repeats in table every f entries */
4216 int g; /* maximum code length */
4217 int h; /* table level */
4218 uInt i; /* counter, current code */
4219 uInt j; /* counter */
4220 int k; /* number of bits in current code */
4221 int l; /* bits per table (returned in m) */
4222 uIntf *p; /* pointer into c[], b[], or v[] */
4223 inflate_huft *q; /* points to current table */
4224 struct inflate_huft_s r; /* table entry for structure assignment */
4225 inflate_huft *u[BMAX]; /* table stack */
4226 uInt v[N_MAX]; /* values in order of bit length */
4227 int w; /* bits before this table == (l * h) */
4228 uInt x[BMAX+1]; /* bit offsets, then code stack */
4229 uIntf *xp; /* pointer into x */
4230 int y; /* number of dummy codes added */
4231 uInt z; /* number of entries in current table */
4234 /* Generate counts for each bit length */
4236 #define C0 *p++ = 0;
4237 #define C2 C0 C0 C0 C0
4238 #define C4 C2 C2 C2 C2
4239 C4 /* clear c[]--assume BMAX+1 is 16 */
4242 c[*p++]++; /* assume all entries <= BMAX */
4244 if (c[0] == n) /* null input--all zero length codes */
4246 *t = (inflate_huft *)Z_NULL;
4252 /* Find minimum and maximum length, bound *m by those */
4254 for (j = 1; j <= BMAX; j++)
4257 k = j; /* minimum code length */
4260 for (i = BMAX; i; i--)
4263 g = i; /* maximum code length */
4269 /* Adjust last length count to fill out codes, if needed */
4270 for (y = 1 << j; j < i; j++, y <<= 1)
4271 if ((y -= c[j]) < 0)
4272 return Z_DATA_ERROR;
4273 if ((y -= c[i]) < 0)
4274 return Z_DATA_ERROR;
4278 /* Generate starting offsets into the value table for each length */
4280 p = c + 1; xp = x + 2;
4281 while (--i) { /* note that i == g from above */
4282 *xp++ = (j += *p++);
4286 /* Make a table of values in order of bit lengths */
4289 if ((j = *p++) != 0)
4292 n = x[g]; /* set n to length of v */
4295 /* Generate the Huffman codes and for each, make the table entries */
4296 x[0] = i = 0; /* first Huffman code is zero */
4297 p = v; /* grab values in bit order */
4298 h = -1; /* no tables yet--level -1 */
4299 w = -l; /* bits decoded == (l * h) */
4300 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
4301 q = (inflate_huft *)Z_NULL; /* ditto */
4304 /* go through the bit lengths (k already is bits in shortest code) */
4310 /* here i is the Huffman code of length k bits for value *p */
4311 /* make tables up to required level */
4315 w += l; /* previous table always l bits */
4317 /* compute minimum size table less than or equal to l bits */
4319 z = z > (uInt)l ? l : z; /* table size upper limit */
4320 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
4321 { /* too few codes for k-w bit table */
4322 f -= a + 1; /* deduct codes from patterns left */
4325 while (++j < z) /* try smaller tables up to z bits */
4327 if ((f <<= 1) <= *++xp)
4328 break; /* enough codes to use up j bits */
4329 f -= *xp; /* else deduct codes from patterns */
4332 z = 1 << j; /* table entries for j-bit table */
4334 /* allocate and link in new table */
4335 if ((q = (inflate_huft *)ZALLOC
4336 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
4339 inflate_trees_free(u[0], zs);
4340 return Z_MEM_ERROR; /* not enough memory */
4343 inflate_hufts += z + 1;
4345 *t = q + 1; /* link to list for huft_free() */
4346 *(t = &(q->next)) = Z_NULL;
4347 u[h] = ++q; /* table starts after link */
4349 /* connect to last table, if there is one */
4352 x[h] = i; /* save pattern for backing up */
4353 r.bits = (Byte)l; /* bits to dump before this table */
4354 r.exop = (Byte)j; /* bits in this table */
4355 r.next = q; /* pointer to this table */
4356 j = i >> (w - l); /* (get around Turbo C bug) */
4357 u[h-1][j] = r; /* connect to last table */
4361 /* set up table entry in r */
4362 r.bits = (Byte)(k - w);
4364 r.exop = 128 + 64; /* out of values--invalid code */
4367 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
4368 r.base = *p++; /* simple code is just the value */
4372 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4373 r.base = d[*p++ - s];
4376 /* fill code-like entries with r */
4378 for (j = i >> w; j < z; j += f)
4381 /* backwards increment the k-bit code i */
4382 for (j = 1 << (k - 1); i & j; j >>= 1)
4386 /* backup over finished tables */
4387 while ((i & ((1 << w) - 1)) != x[h])
4389 h--; /* don't need to update q */
4396 /* Return Z_BUF_ERROR if we were given an incomplete table */
4397 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4402 * c: 19 code lengths
4403 * bb: bits tree desired/actual depth
4404 * tb: bits tree result
4405 * z: for zfree function
4408 inflate_trees_bits(uIntf *c, uIntf *bb, inflate_huft * FAR *tb, z_streamp z)
4412 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
4413 if (r == Z_DATA_ERROR)
4414 z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4415 else if (r == Z_BUF_ERROR || *bb == 0)
4417 inflate_trees_free(*tb, z);
4418 z->msg = (char*)"incomplete dynamic bit lengths tree";
4426 * nl: number of literal/length codes
4427 * nd: number of distance codes
4428 * c: that many (total) code lengths
4429 * bl: literal desired/actual bit depth
4430 * bd: distance desired/actual bit depth
4431 * tl: literal/length tree result
4432 * td: distance tree result
4433 * z: for zfree function
4436 inflate_trees_dynamic(uInt nl, uInt nd, uIntf *c, uIntf *bl, uIntf *bd,
4437 inflate_huft * FAR *tl, inflate_huft * FAR *td,
4442 /* build literal/length tree */
4443 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z);
4444 if (r != Z_OK || *bl == 0)
4446 if (r == Z_DATA_ERROR)
4447 z->msg = (char*)"oversubscribed literal/length tree";
4448 else if (r != Z_MEM_ERROR)
4450 inflate_trees_free(*tl, z);
4451 z->msg = (char*)"incomplete literal/length tree";
4457 /* build distance tree */
4458 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z);
4459 if (r != Z_OK || (*bd == 0 && nl > 257))
4461 if (r == Z_DATA_ERROR)
4462 z->msg = (char*)"oversubscribed distance tree";
4463 else if (r == Z_BUF_ERROR) {
4464 #ifdef PKZIP_BUG_WORKAROUND
4468 inflate_trees_free(*td, z);
4469 z->msg = (char*)"incomplete distance tree";
4472 else if (r != Z_MEM_ERROR)
4474 z->msg = (char*)"empty distance tree with lengths";
4477 inflate_trees_free(*tl, z);
4487 /* build fixed tables only once--keep them here */
4488 local int fixed_built = 0;
4489 #define FIXEDH 530 /* number of hufts used by fixed tables */
4490 local inflate_huft fixed_mem[FIXEDH];
4491 local uInt fixed_bl;
4492 local uInt fixed_bd;
4493 local inflate_huft *fixed_tl;
4494 local inflate_huft *fixed_td;
4499 * n: number of items
4503 falloc(voidpf q, uInt n, uInt s)
4505 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q,
4506 "inflate_trees falloc overflow");
4507 *(intf *)q -= n+s-s; /* s-s to avoid warning */
4508 return (voidpf)(fixed_mem + *(intf *)q);
4513 * bl: literal desired/actual bit depth
4514 * bd: distance desired/actual bit depth
4515 * tl: literal/length tree result
4516 * td: distance tree result
4519 inflate_trees_fixed(uIntf *bl, uIntf *bd, inflate_huft * FAR *tl,
4520 inflate_huft * FAR *td)
4522 /* build fixed tables if not already (multiple overlapped executions ok) */
4525 int k; /* temporary variable */
4526 unsigned c[288]; /* length list for huft_build */
4527 z_stream z; /* for falloc function */
4528 int f = FIXEDH; /* number of hufts left in fixed_mem */
4530 /* set up fake z_stream for memory routines */
4533 z.opaque = (voidpf)&f;
4536 for (k = 0; k < 144; k++)
4538 for (; k < 256; k++)
4540 for (; k < 280; k++)
4542 for (; k < 288; k++)
4545 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4547 /* distance table */
4548 for (k = 0; k < 30; k++)
4551 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4554 Assert(f == 0, "invalid build of fixed tables");
4567 * z: for zfree function
4568 * Free the malloc'ed tables built by huft_build(), which makes a linked
4569 * list of the tables it made, with the links in a dummy first entry of
4573 inflate_trees_free(inflate_huft *t, z_streamp z)
4575 inflate_huft *p, *q, *r;
4577 /* Reverse linked list */
4587 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4596 /* --- inftrees.c */
4598 /* +++ infcodes.c */
4599 /* infcodes.c -- process literals and length/distance pairs
4600 * Copyright (C) 1995-1996 Mark Adler
4601 * For conditions of distribution and use, see copyright notice in zlib.h
4604 /* #include "zutil.h" */
4605 /* #include "inftrees.h" */
4606 /* #include "infblock.h" */
4607 /* #include "infcodes.h" */
4608 /* #include "infutil.h" */
4611 /* inffast.h -- header to use inffast.c
4612 * Copyright (C) 1995-1996 Mark Adler
4613 * For conditions of distribution and use, see copyright notice in zlib.h
4616 /* WARNING: this file should *not* be used by applications. It is
4617 part of the implementation of the compression library and is
4618 subject to change. Applications should only use zlib.h.
4621 extern int inflate_fast OF((
4626 inflate_blocks_statef *,
4630 /* simplify the use of the inflate_huft type with some defines */
4631 #define base more.Base
4632 #define next more.Next
4633 #define exop word.what.Exop
4634 #define bits word.what.Bits
4636 /* inflate codes private state */
4637 struct inflate_codes_state {
4640 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4641 START, /* x: set up for LEN */
4642 LEN, /* i: get length/literal/eob next */
4643 LENEXT, /* i: getting length extra (have base) */
4644 DIST, /* i: get distance next */
4645 DISTEXT, /* i: getting distance extra */
4646 COPY, /* o: copying bytes in window, waiting for space */
4647 LIT, /* o: got literal, waiting for output space */
4648 WASH, /* o: got eob, possibly still output waiting */
4649 END, /* x: got eob and all data flushed */
4650 BADCODE} /* x: got error */
4651 mode; /* current inflate_codes mode */
4653 /* mode dependent information */
4657 inflate_huft *tree; /* pointer into tree */
4658 uInt need; /* bits needed */
4659 } code; /* if LEN or DIST, where in tree */
4660 uInt lit; /* if LIT, literal */
4662 uInt get; /* bits to get for extra */
4663 uInt dist; /* distance back to copy from */
4664 } copy; /* if EXT or COPY, where and how much */
4665 } sub; /* submode */
4667 /* mode independent information */
4668 Byte lbits; /* ltree bits decoded per branch */
4669 Byte dbits; /* dtree bits decoder per branch */
4670 inflate_huft *ltree; /* literal/length/eob tree */
4671 inflate_huft *dtree; /* distance tree */
4677 * td: need separate declaration for Borland C++
4679 inflate_codes_statef *
4680 inflate_codes_new(uInt bl, uInt bd, inflate_huft *tl, inflate_huft *td,
4683 inflate_codes_statef *c;
4685 if ((c = (inflate_codes_statef *)
4686 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4689 c->lbits = (Byte)bl;
4690 c->dbits = (Byte)bd;
4693 Tracev((stderr, "inflate: codes new\n"));
4700 inflate_codes(inflate_blocks_statef *s, z_streamp z, int r)
4702 uInt j; /* temporary storage */
4703 inflate_huft *t; /* temporary pointer */
4704 uInt e; /* extra bits or operation */
4705 uLong b; /* bit buffer */
4706 uInt k; /* bits in bit buffer */
4707 Bytef *p; /* input data pointer */
4708 uInt n; /* bytes available there */
4709 Bytef *q; /* output window write pointer */
4710 uInt m; /* bytes to end of window or read pointer */
4711 Bytef *f; /* pointer to copy strings from */
4712 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4714 /* copy input/output information to locals (UPDATE macro restores) */
4717 /* process input and output based on current state */
4718 while (1) switch (c->mode)
4719 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4720 case START: /* x: set up for LEN */
4722 if (m >= 258 && n >= 10)
4725 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4729 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4734 c->sub.code.need = c->lbits;
4735 c->sub.code.tree = c->ltree;
4737 case LEN: /* i: get length/literal/eob next */
4738 j = c->sub.code.need;
4740 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4742 e = (uInt)(t->exop);
4743 if (e == 0) /* literal */
4745 c->sub.lit = t->base;
4746 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4747 "inflate: literal '%c'\n" :
4748 "inflate: literal 0x%02x\n", t->base));
4752 if (e & 16) /* length */
4754 c->sub.copy.get = e & 15;
4759 if ((e & 64) == 0) /* next table */
4761 c->sub.code.need = e;
4762 c->sub.code.tree = t->next;
4765 if (e & 32) /* end of block */
4767 Tracevv((stderr, "inflate: end of block\n"));
4771 c->mode = BADCODE; /* invalid code */
4772 z->msg = (char*)"invalid literal/length code";
4775 case LENEXT: /* i: getting length extra (have base) */
4776 j = c->sub.copy.get;
4778 c->len += (uInt)b & inflate_mask[j];
4780 c->sub.code.need = c->dbits;
4781 c->sub.code.tree = c->dtree;
4782 Tracevv((stderr, "inflate: length %u\n", c->len));
4784 case DIST: /* i: get distance next */
4785 j = c->sub.code.need;
4787 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4789 e = (uInt)(t->exop);
4790 if (e & 16) /* distance */
4792 c->sub.copy.get = e & 15;
4793 c->sub.copy.dist = t->base;
4797 if ((e & 64) == 0) /* next table */
4799 c->sub.code.need = e;
4800 c->sub.code.tree = t->next;
4803 c->mode = BADCODE; /* invalid code */
4804 z->msg = (char*)"invalid distance code";
4807 case DISTEXT: /* i: getting distance extra */
4808 j = c->sub.copy.get;
4810 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4812 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4814 case COPY: /* o: copying bytes in window, waiting for space */
4815 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4816 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4817 s->end - (c->sub.copy.dist - (q - s->window)) :
4818 q - c->sub.copy.dist;
4820 f = q - c->sub.copy.dist;
4821 if ((uInt)(q - s->window) < c->sub.copy.dist)
4822 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
4834 case LIT: /* o: got literal, waiting for output space */
4839 case WASH: /* o: got eob, possibly more output */
4841 if (s->read != s->write)
4847 case BADCODE: /* x: got error */
4858 inflate_codes_free(inflate_codes_statef *c, z_streamp z)
4861 Tracev((stderr, "inflate: codes free\n"));
4863 /* --- infcodes.c */
4866 /* inflate_util.c -- data and routines common to blocks and codes
4867 * Copyright (C) 1995-1996 Mark Adler
4868 * For conditions of distribution and use, see copyright notice in zlib.h
4871 /* #include "zutil.h" */
4872 /* #include "infblock.h" */
4873 /* #include "inftrees.h" */
4874 /* #include "infcodes.h" */
4875 /* #include "infutil.h" */
4877 #ifndef NO_DUMMY_DECL
4878 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4881 /* And'ing with mask[n] masks the lower n bits */
4882 uInt inflate_mask[17] = {
4884 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
4885 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
4889 /* copy as much as possible from the sliding window to the output area */
4891 inflate_flush(inflate_blocks_statef *s, z_streamp z, int r)
4897 /* local copies of source and destination pointers */
4901 /* compute number of bytes to copy as far as end of window */
4902 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4903 if (n > z->avail_out) n = z->avail_out;
4904 if (n && r == Z_BUF_ERROR) r = Z_OK;
4906 /* update counters */
4910 /* update check information */
4911 if (s->checkfn != Z_NULL)
4912 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4914 /* copy as far as end of window */
4921 /* see if more to copy at beginning of window */
4926 if (s->write == s->end)
4927 s->write = s->window;
4929 /* compute bytes to copy */
4930 n = (uInt)(s->write - q);
4931 if (n > z->avail_out) n = z->avail_out;
4932 if (n && r == Z_BUF_ERROR) r = Z_OK;
4934 /* update counters */
4938 /* update check information */
4939 if (s->checkfn != Z_NULL)
4940 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4950 /* update pointers */
4960 /* inffast.c -- process literals and length/distance pairs fast
4961 * Copyright (C) 1995-1996 Mark Adler
4962 * For conditions of distribution and use, see copyright notice in zlib.h
4965 /* #include "zutil.h" */
4966 /* #include "inftrees.h" */
4967 /* #include "infblock.h" */
4968 /* #include "infcodes.h" */
4969 /* #include "infutil.h" */
4970 /* #include "inffast.h" */
4972 #ifndef NO_DUMMY_DECL
4973 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4976 /* simplify the use of the inflate_huft type with some defines */
4977 #define base more.Base
4978 #define next more.Next
4979 #define exop word.what.Exop
4980 #define bits word.what.Bits
4982 /* macros for bit input with no checking and for returning unused bytes */
4983 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4984 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4986 /* Called with number of bytes left to write in window at least 258
4987 * (the maximum string length) and number of input bytes available
4988 * at least ten. The ten bytes are six bytes for the longest length/
4989 * distance pair plus four bytes for overloading the bit buffer.
4992 * td: need separate declaration for Borland C++
4995 inflate_fast(uInt bl, uInt bd, inflate_huft *tl, inflate_huft *td,
4996 inflate_blocks_statef *s, z_streamp z)
4998 inflate_huft *t; /* temporary pointer */
4999 uInt e; /* extra bits or operation */
5000 uLong b; /* bit buffer */
5001 uInt k; /* bits in bit buffer */
5002 Bytef *p; /* input data pointer */
5003 uInt n; /* bytes available there */
5004 Bytef *q; /* output window write pointer */
5005 uInt m; /* bytes to end of window or read pointer */
5006 uInt ml; /* mask for literal/length tree */
5007 uInt md; /* mask for distance tree */
5008 uInt c; /* bytes to copy */
5009 uInt d; /* distance back to copy from */
5010 Bytef *r; /* copy source pointer */
5012 /* load input, output, bit values */
5015 /* initialize masks */
5016 ml = inflate_mask[bl];
5017 md = inflate_mask[bd];
5019 /* do until not enough input or output space for fast loop */
5020 do { /* assume called with m >= 258 && n >= 10 */
5021 /* get literal/length code */
5022 GRABBITS(20) /* max bits for literal/length code */
5023 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5026 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5027 "inflate: * literal '%c'\n" :
5028 "inflate: * literal 0x%02x\n", t->base));
5029 *q++ = (Byte)t->base;
5037 /* get extra bits for length */
5039 c = t->base + ((uInt)b & inflate_mask[e]);
5041 Tracevv((stderr, "inflate: * length %u\n", c));
5043 /* decode distance base of block to copy */
5044 GRABBITS(15); /* max bits for distance code */
5045 e = (t = td + ((uInt)b & md))->exop;
5050 /* get extra bits to add to distance base */
5052 GRABBITS(e) /* get extra bits (up to 13) */
5053 d = t->base + ((uInt)b & inflate_mask[e]);
5055 Tracevv((stderr, "inflate: * distance %u\n", d));
5059 if ((uInt)(q - s->window) >= d) /* offset before dest */
5062 *q++ = *r++; c--; /* minimum count is three, */
5063 *q++ = *r++; c--; /* so unroll loop a little */
5065 else /* else offset after destination */
5067 e = d - (uInt)(q - s->window); /* bytes from offset to end */
5068 r = s->end - e; /* pointer to offset */
5069 if (c > e) /* if source crosses, */
5071 c -= e; /* copy to end of window */
5075 r = s->window; /* copy rest from start of window */
5078 do { /* copy all or what's left */
5083 else if ((e & 64) == 0)
5084 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
5087 z->msg = (char*)"invalid distance code";
5090 return Z_DATA_ERROR;
5097 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
5100 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5101 "inflate: * literal '%c'\n" :
5102 "inflate: * literal 0x%02x\n", t->base));
5103 *q++ = (Byte)t->base;
5110 Tracevv((stderr, "inflate: * end of block\n"));
5113 return Z_STREAM_END;
5117 z->msg = (char*)"invalid literal/length code";
5120 return Z_DATA_ERROR;
5123 } while (m >= 258 && n >= 10);
5125 /* not enough input or output--restore pointers and return */
5133 /* zutil.c -- target dependent utility functions for the compression library
5134 * Copyright (C) 1995-1996 Jean-loup Gailly.
5135 * For conditions of distribution and use, see copyright notice in zlib.h
5138 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */
5144 /* #include "zutil.h" */
5146 #ifndef NO_DUMMY_DECL
5147 struct internal_state {int dummy;}; /* for buggy compilers */
5151 extern void exit OF((int));
5154 static const char *z_errmsg[10] = {
5155 "need dictionary", /* Z_NEED_DICT 2 */
5156 "stream end", /* Z_STREAM_END 1 */
5158 "file error", /* Z_ERRNO (-1) */
5159 "stream error", /* Z_STREAM_ERROR (-2) */
5160 "data error", /* Z_DATA_ERROR (-3) */
5161 "insufficient memory", /* Z_MEM_ERROR (-4) */
5162 "buffer error", /* Z_BUF_ERROR (-5) */
5163 "incompatible version",/* Z_VERSION_ERROR (-6) */
5170 return ZLIB_VERSION;
5177 fprintf(stderr, "%s\n", m);
5185 zmemcpy(Bytef *dest, Bytef *source, uInt len)
5187 if (len == 0) return;
5189 *dest++ = *source++; /* ??? to be unrolled */
5190 } while (--len != 0);
5194 zmemcmp(Bytef *s1, Bytef *s2, uInt len)
5198 for (j = 0; j < len; j++) {
5199 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5205 zmemzero(Bytef *dest, uInt len)
5207 if (len == 0) return;
5209 *dest++ = 0; /* ??? to be unrolled */
5210 } while (--len != 0);
5215 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5216 /* Small and medium model in Turbo C are for now limited to near allocation
5217 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5221 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5222 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5223 * must fix the pointer. Warning: the pointer must be put back to its
5224 * original form in order to free it, use zcfree().
5230 local int next_ptr = 0;
5232 typedef struct ptr_table_s {
5237 local ptr_table table[MAX_PTR];
5238 /* This table is used to remember the original form of pointers
5239 * to large buffers (64K). Such pointers are normalized with a zero offset.
5240 * Since MSDOS is not a preemptive multitasking OS, this table is not
5241 * protected from concurrent access. This hack doesn't work anyway on
5242 * a protected system like OS/2. Use Microsoft C instead.
5246 zcalloc(voidpf opaque, unsigned items, unsigned size)
5248 voidpf buf = opaque; /* just to make some compilers happy */
5249 ulg bsize = (ulg)items*size;
5251 /* If we allocate less than 65520 bytes, we assume that farmalloc
5252 * will return a usable pointer which doesn't have to be normalized.
5254 if (bsize < 65520L) {
5255 buf = farmalloc(bsize);
5256 if (*(ush*)&buf != 0) return buf;
5258 buf = farmalloc(bsize + 16L);
5260 if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5261 table[next_ptr].org_ptr = buf;
5263 /* Normalize the pointer to seg:0 */
5264 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5266 table[next_ptr++].new_ptr = buf;
5271 zcfree(voidpf opaque, voidpf ptr)
5274 if (*(ush*)&ptr != 0) { /* object < 64K */
5278 /* Find the original pointer */
5279 for (n = 0; n < next_ptr; n++) {
5280 if (ptr != table[n].new_ptr) continue;
5282 farfree(table[n].org_ptr);
5283 while (++n < next_ptr) {
5284 table[n-1] = table[n];
5289 ptr = opaque; /* just to make some compilers happy */
5290 Assert(0, "zcfree: ptr not found");
5293 #endif /* __TURBOC__ */
5296 #if defined(M_I86) && !defined(__32BIT__)
5297 /* Microsoft C in 16-bit mode */
5301 #if (!defined(_MSC_VER) || (_MSC_VER < 600))
5302 # define _halloc halloc
5303 # define _hfree hfree
5307 zcalloc(voidpf opaque, unsigned items, unsigned size)
5309 if (opaque) opaque = 0; /* to make compiler happy */
5310 return _halloc((long)items, size);
5314 zcfree(voidpf opaque, voidpf ptr)
5316 if (opaque) opaque = 0; /* to make compiler happy */
5323 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5326 extern voidp calloc OF((uInt items, uInt size));
5327 extern void free OF((voidpf ptr));
5331 zcalloc(voidpf opaque, unsigned items, unsigned size)
5333 if (opaque) items += size - size; /* make compiler happy */
5334 return (voidpf)calloc(items, size);
5338 zcfree(voidpf opaque, voidpf ptr)
5341 if (opaque) return; /* make compiler happy */
5344 #endif /* MY_ZCALLOC */
5348 /* adler32.c -- compute the Adler-32 checksum of a data stream
5349 * Copyright (C) 1995-1996 Mark Adler
5350 * For conditions of distribution and use, see copyright notice in zlib.h
5353 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */
5355 /* #include "zlib.h" */
5357 #define BASE 65521L /* largest prime smaller than 65536 */
5359 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5361 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;}
5362 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
5363 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
5364 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
5365 #define DO16(buf) DO8(buf,0); DO8(buf,8);
5367 /* ========================================================================= */
5369 adler32(uLong adler, const Bytef *buf, uInt len)
5371 unsigned long s1 = adler & 0xffff;
5372 unsigned long s2 = (adler >> 16) & 0xffff;
5375 if (buf == Z_NULL) return 1L;
5378 k = len < NMAX ? len : NMAX;
5392 return (s2 << 16) | s1;