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
17 * ==FILEVERSION 971210==
19 * This marker is used by the Linux installation script to determine
20 * whether an up-to-date version of this file is already installed.
27 #if defined(__FreeBSD__) && defined(_KERNEL)
28 #define _tr_init _zlib104_tr_init
29 #define _tr_align _zlib104_tr_align
30 #define _tr_tally _zlib104_tr_tally
31 #define _tr_flush_block _zlib104_tr_flush_block
32 #define _tr_stored_block _zlib104_tr_stored_block
33 #define inflate_fast _zlib104_inflate_fast
34 #define inflate _zlib104_inflate
35 #define zlibVersion _zlib104_Version
41 * zutil.h -- internal interface and configuration of the compression library
42 * Copyright (C) 1995-1996 Jean-loup Gailly.
43 * For conditions of distribution and use, see copyright notice in zlib.h
46 /* WARNING: this file should *not* be used by applications. It is
47 part of the implementation of the compression library and is
48 subject to change. Applications should only use zlib.h.
51 /* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */
63 /* Assume this is a *BSD or SVR4 kernel */
64 #include <sys/types.h>
66 #include <sys/systm.h>
67 #include <sys/param.h>
68 #include <sys/kernel.h>
69 #include <sys/module.h>
73 #if defined(__KERNEL__)
74 /* Assume this is a Linux kernel */
75 #include <linux/string.h>
78 #else /* not kernel */
80 #if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS)
90 #endif /* __KERNEL__ */
96 /* compile with -Dlocal if your debugger can't find static symbols */
98 typedef unsigned char uch;
100 typedef unsigned short ush;
101 typedef ush FAR ushf;
102 typedef unsigned long ulg;
104 static const char *z_errmsg[10]; /* indexed by 2-zlib_error */
105 /* (size given to avoid silly warnings with Visual C++) */
107 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
109 #define ERR_RETURN(strm,err) \
110 return (strm->msg = (const char*)ERR_MSG(err), (err))
111 /* To be used only when the state is known to be valid */
113 /* common constants */
116 # define DEF_WBITS MAX_WBITS
118 /* default windowBits for decompression. MAX_WBITS is for compression only */
120 #if MAX_MEM_LEVEL >= 8
121 # define DEF_MEM_LEVEL 8
123 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
125 /* default memLevel */
127 #define STORED_BLOCK 0
128 #define STATIC_TREES 1
130 /* The three kinds of block type */
133 #define MAX_MATCH 258
134 /* The minimum and maximum match lengths */
136 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
138 /* target dependencies */
141 # define OS_CODE 0x00
144 # else /* MSC or DJGPP */
150 # define OS_CODE 0x06
153 #ifdef WIN32 /* Window 95 & Windows NT */
154 # define OS_CODE 0x0b
157 #if defined(VAXC) || defined(VMS)
158 # define OS_CODE 0x02
159 # define FOPEN(name, mode) \
160 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
164 # define OS_CODE 0x01
167 #if defined(ATARI) || defined(atarist)
168 # define OS_CODE 0x05
172 # define OS_CODE 0x07
175 #ifdef __50SERIES /* Prime/PRIMOS */
176 # define OS_CODE 0x0F
180 # define OS_CODE 0x0a
183 #if defined(_BEOS_) || defined(RISCOS)
184 # define fdopen(fd,mode) NULL /* No fdopen() */
187 /* Common defaults */
190 # define OS_CODE 0x03 /* assume Unix */
194 # define FOPEN(name, mode) fopen((name), (mode))
200 extern char *strerror OF((int));
201 # define zstrerror(errnum) strerror(errnum)
203 # define zstrerror(errnum) ""
209 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
210 /* Use our own functions for small and medium model with MSC <= 5.0.
211 * You may have to use the same strategy for Borland C (untested).
215 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
219 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */
220 # define zmemcpy _fmemcpy
221 # define zmemcmp _fmemcmp
222 # define zmemzero(dest, len) _fmemset(dest, 0, len)
224 # define zmemcpy memcpy
225 # define zmemcmp memcmp
226 # define zmemzero(dest, len) memset(dest, 0, len)
229 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
230 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len));
231 extern void zmemzero OF((Bytef* dest, uInt len));
234 /* Diagnostic functions */
240 extern void z_error OF((char *m));
241 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
242 # define Trace(x) fprintf x
243 # define Tracev(x) {if (verbose) fprintf x ;}
244 # define Tracevv(x) {if (verbose>1) fprintf x ;}
245 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
246 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
248 # define Assert(cond,msg)
253 # define Tracecv(c,x)
257 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));
259 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
260 void zcfree OF((voidpf opaque, voidpf ptr));
262 #define ZALLOC(strm, items, size) \
263 (*((strm)->zalloc))((strm)->opaque, (items), (size))
264 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
265 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
267 #endif /* _Z_UTIL_H */
271 /* deflate.h -- internal compression state
272 * Copyright (C) 1995-1996 Jean-loup Gailly
273 * For conditions of distribution and use, see copyright notice in zlib.h
276 /* WARNING: this file should *not* be used by applications. It is
277 part of the implementation of the compression library and is
278 subject to change. Applications should only use zlib.h.
281 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */
286 /* #include "zutil.h" */
288 /* ===========================================================================
289 * Internal compression state.
292 #define LENGTH_CODES 29
293 /* number of length codes, not counting the special END_BLOCK code */
296 /* number of literal bytes 0..255 */
298 #define L_CODES (LITERALS+1+LENGTH_CODES)
299 /* number of Literal or Length codes, including the END_BLOCK code */
302 /* number of distance codes */
305 /* number of codes used to transfer the bit lengths */
307 #define HEAP_SIZE (2*L_CODES+1)
308 /* maximum heap size */
311 /* All codes must not exceed MAX_BITS bits */
313 #define INIT_STATE 42
314 #define BUSY_STATE 113
315 #define FINISH_STATE 666
319 /* Data structure describing a single value and its code string. */
320 typedef struct ct_data_s {
322 ush freq; /* frequency count */
323 ush code; /* bit string */
326 ush dad; /* father node in Huffman tree */
327 ush len; /* length of bit string */
336 typedef struct static_tree_desc_s static_tree_desc;
338 typedef struct tree_desc_s {
339 ct_data *dyn_tree; /* the dynamic tree */
340 int max_code; /* largest code with non zero frequency */
341 static_tree_desc *stat_desc; /* the corresponding static tree */
345 typedef Pos FAR Posf;
346 typedef unsigned IPos;
348 /* A Pos is an index in the character window. We use short instead of int to
349 * save space in the various tables. IPos is used only for parameter passing.
352 typedef struct deflate_state {
353 z_streamp strm; /* pointer back to this zlib stream */
354 int status; /* as the name implies */
355 Bytef *pending_buf; /* output still pending */
356 ulg pending_buf_size; /* size of pending_buf */
357 Bytef *pending_out; /* next pending byte to output to the stream */
358 int pending; /* nb of bytes in the pending buffer */
359 int noheader; /* suppress zlib header and adler32 */
360 Byte data_type; /* UNKNOWN, BINARY or ASCII */
361 Byte method; /* STORED (for zip only) or DEFLATED */
362 int last_flush; /* value of flush param for previous deflate call */
364 /* used by deflate.c: */
366 uInt w_size; /* LZ77 window size (32K by default) */
367 uInt w_bits; /* log2(w_size) (8..16) */
368 uInt w_mask; /* w_size - 1 */
371 /* Sliding window. Input bytes are read into the second half of the window,
372 * and move to the first half later to keep a dictionary of at least wSize
373 * bytes. With this organization, matches are limited to a distance of
374 * wSize-MAX_MATCH bytes, but this ensures that IO is always
375 * performed with a length multiple of the block size. Also, it limits
376 * the window size to 64K, which is quite useful on MSDOS.
377 * To do: use the user input buffer as sliding window.
381 /* Actual size of window: 2*wSize, except when the user input buffer
382 * is directly used as sliding window.
386 /* Link to older string with same hash index. To limit the size of this
387 * array to 64K, this link is maintained only for the last 32K strings.
388 * An index in this array is thus a window index modulo 32K.
391 Posf *head; /* Heads of the hash chains or NIL. */
393 uInt ins_h; /* hash index of string to be inserted */
394 uInt hash_size; /* number of elements in hash table */
395 uInt hash_bits; /* log2(hash_size) */
396 uInt hash_mask; /* hash_size-1 */
399 /* Number of bits by which ins_h must be shifted at each input
400 * step. It must be such that after MIN_MATCH steps, the oldest
401 * byte no longer takes part in the hash key, that is:
402 * hash_shift * MIN_MATCH >= hash_bits
406 /* Window position at the beginning of the current output block. Gets
407 * negative when the window is moved backwards.
410 uInt match_length; /* length of best match */
411 IPos prev_match; /* previous match */
412 int match_available; /* set if previous match exists */
413 uInt strstart; /* start of string to insert */
414 uInt match_start; /* start of matching string */
415 uInt lookahead; /* number of valid bytes ahead in window */
418 /* Length of the best match at previous step. Matches not greater than this
419 * are discarded. This is used in the lazy match evaluation.
422 uInt max_chain_length;
423 /* To speed up deflation, hash chains are never searched beyond this
424 * length. A higher limit improves compression ratio but degrades the
429 /* Attempt to find a better match only when the current match is strictly
430 * smaller than this value. This mechanism is used only for compression
433 # define max_insert_length max_lazy_match
434 /* Insert new strings in the hash table only if the match length is not
435 * greater than this length. This saves time but degrades compression.
436 * max_insert_length is used only for compression levels <= 3.
439 int level; /* compression level (1..9) */
440 int strategy; /* favor or force Huffman coding*/
443 /* Use a faster search when the previous match is longer than this */
445 int nice_match; /* Stop searching when current match exceeds this */
447 /* used by trees.c: */
448 /* Didn't use ct_data typedef below to supress compiler warning */
449 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
450 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
451 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
453 struct tree_desc_s l_desc; /* desc. for literal tree */
454 struct tree_desc_s d_desc; /* desc. for distance tree */
455 struct tree_desc_s bl_desc; /* desc. for bit length tree */
457 ush bl_count[MAX_BITS+1];
458 /* number of codes at each bit length for an optimal tree */
460 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
461 int heap_len; /* number of elements in the heap */
462 int heap_max; /* element of largest frequency */
463 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
464 * The same heap array is used to build all trees.
467 uch depth[2*L_CODES+1];
468 /* Depth of each subtree used as tie breaker for trees of equal frequency
471 uchf *l_buf; /* buffer for literals or lengths */
474 /* Size of match buffer for literals/lengths. There are 4 reasons for
475 * limiting lit_bufsize to 64K:
476 * - frequencies can be kept in 16 bit counters
477 * - if compression is not successful for the first block, all input
478 * data is still in the window so we can still emit a stored block even
479 * when input comes from standard input. (This can also be done for
480 * all blocks if lit_bufsize is not greater than 32K.)
481 * - if compression is not successful for a file smaller than 64K, we can
482 * even emit a stored file instead of a stored block (saving 5 bytes).
483 * This is applicable only for zip (not gzip or zlib).
484 * - creating new Huffman trees less frequently may not provide fast
485 * adaptation to changes in the input data statistics. (Take for
486 * example a binary file with poorly compressible code followed by
487 * a highly compressible string table.) Smaller buffer sizes give
488 * fast adaptation but have of course the overhead of transmitting
489 * trees more frequently.
490 * - I can't count above 4
493 uInt last_lit; /* running index in l_buf */
496 /* Buffer for distances. To simplify the code, d_buf and l_buf have
497 * the same number of elements. To use different lengths, an extra flag
498 * array would be necessary.
501 ulg opt_len; /* bit length of current block with optimal trees */
502 ulg static_len; /* bit length of current block with static trees */
503 ulg compressed_len; /* total bit length of compressed file */
504 uInt matches; /* number of string matches in current block */
505 int last_eob_len; /* bit length of EOB code for last block */
508 ulg bits_sent; /* bit length of the compressed data */
512 /* Output buffer. bits are inserted starting at the bottom (least
516 /* Number of valid bits in bi_buf. All bits above the last valid bit
522 /* Output a byte on the stream.
523 * IN assertion: there is enough room in pending_buf.
525 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
528 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
529 /* Minimum amount of lookahead, except at the end of the input file.
530 * See deflate.c for comments about the MIN_MATCH+1.
533 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
534 /* In order to simplify the code, particularly on 16 bit machines, match
535 * distances are limited to MAX_DIST instead of WSIZE.
539 void _tr_init OF((deflate_state *s));
540 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
541 ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
543 void _tr_align OF((deflate_state *s));
544 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
546 void _tr_stored_type_only OF((deflate_state *));
552 /* deflate.c -- compress data using the deflation algorithm
553 * Copyright (C) 1995-1996 Jean-loup Gailly.
554 * For conditions of distribution and use, see copyright notice in zlib.h
560 * The "deflation" process depends on being able to identify portions
561 * of the input text which are identical to earlier input (within a
562 * sliding window trailing behind the input currently being processed).
564 * The most straightforward technique turns out to be the fastest for
565 * most input files: try all possible matches and select the longest.
566 * The key feature of this algorithm is that insertions into the string
567 * dictionary are very simple and thus fast, and deletions are avoided
568 * completely. Insertions are performed at each input character, whereas
569 * string matches are performed only when the previous match ends. So it
570 * is preferable to spend more time in matches to allow very fast string
571 * insertions and avoid deletions. The matching algorithm for small
572 * strings is inspired from that of Rabin & Karp. A brute force approach
573 * is used to find longer strings when a small match has been found.
574 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
575 * (by Leonid Broukhis).
576 * A previous version of this file used a more sophisticated algorithm
577 * (by Fiala and Greene) which is guaranteed to run in linear amortized
578 * time, but has a larger average cost, uses more memory and is patented.
579 * However the F&G algorithm may be faster for some highly redundant
580 * files if the parameter max_chain_length (described below) is too large.
584 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
585 * I found it in 'freeze' written by Leonid Broukhis.
586 * Thanks to many people for bug reports and testing.
590 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
591 * Available in ftp://ds.internic.net/rfc/rfc1951.txt
593 * A description of the Rabin and Karp algorithm is given in the book
594 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
596 * Fiala,E.R., and Greene,D.H.
597 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
601 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */
603 /* #include "deflate.h" */
605 char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly ";
607 If you use the zlib library in a product, an acknowledgment is welcome
608 in the documentation of your product. If for some reason you cannot
609 include such an acknowledgment, I would appreciate that you keep this
610 copyright string in the executable of your product.
613 /* ===========================================================================
614 * Function prototypes.
617 need_more, /* block not completed, need more input or more output */
618 block_done, /* block flush performed */
619 finish_started, /* finish started, need only more output at next deflate */
620 finish_done /* finish done, accept no more input or output */
623 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
624 /* Compression function. Returns the block state after the call. */
626 local void fill_window OF((deflate_state *s));
627 local block_state deflate_stored OF((deflate_state *s, int flush));
628 local block_state deflate_fast OF((deflate_state *s, int flush));
629 local block_state deflate_slow OF((deflate_state *s, int flush));
630 local void lm_init OF((deflate_state *s));
631 local void putShortMSB OF((deflate_state *s, uInt b));
632 local void flush_pending OF((z_streamp strm));
633 local int read_buf OF((z_streamp strm, charf *buf, unsigned size));
635 void match_init OF((void)); /* asm code initialization */
636 uInt longest_match OF((deflate_state *s, IPos cur_match));
638 local uInt longest_match OF((deflate_state *s, IPos cur_match));
642 local void check_match OF((deflate_state *s, IPos start, IPos match,
646 /* ===========================================================================
651 /* Tail of hash chains */
654 # define TOO_FAR 4096
656 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
658 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
659 /* Minimum amount of lookahead, except at the end of the input file.
660 * See deflate.c for comments about the MIN_MATCH+1.
663 /* Values for max_lazy_match, good_match and max_chain_length, depending on
664 * the desired pack level (0..9). The values given below have been tuned to
665 * exclude worst case performance for pathological files. Better values may be
666 * found for specific files.
668 typedef struct config_s {
669 ush good_length; /* reduce lazy search above this match length */
670 ush max_lazy; /* do not perform lazy search above this match length */
671 ush nice_length; /* quit search above this match length */
676 local config configuration_table[10] = {
677 /* good lazy nice chain */
678 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
679 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */
680 /* 2 */ {4, 5, 16, 8, deflate_fast},
681 /* 3 */ {4, 6, 32, 32, deflate_fast},
683 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
684 /* 5 */ {8, 16, 32, 32, deflate_slow},
685 /* 6 */ {8, 16, 128, 128, deflate_slow},
686 /* 7 */ {8, 32, 128, 256, deflate_slow},
687 /* 8 */ {32, 128, 258, 1024, deflate_slow},
688 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
690 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
691 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
696 /* result of memcmp for equal strings */
698 #ifndef NO_DUMMY_DECL
699 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
702 /* ===========================================================================
703 * Update a hash value with the given input byte
704 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
705 * input characters, so that a running hash key can be computed from the
706 * previous key instead of complete recalculation each time.
708 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
711 /* ===========================================================================
712 * Insert string str in the dictionary and set match_head to the previous head
713 * of the hash chain (the most recent string with same hash key). Return
714 * the previous length of the hash chain.
715 * IN assertion: all calls to to INSERT_STRING are made with consecutive
716 * input characters and the first MIN_MATCH bytes of str are valid
717 * (except for the last MIN_MATCH-1 bytes of the input file).
719 #define INSERT_STRING(s, str, match_head) \
720 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
721 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
722 s->head[s->ins_h] = (Pos)(str))
724 /* ===========================================================================
725 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
726 * prev[] will be initialized on the fly.
728 #define CLEAR_HASH(s) \
729 s->head[s->hash_size-1] = NIL; \
730 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
732 /* ========================================================================= */
733 int deflateInit_(strm, level, version, stream_size)
739 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
740 Z_DEFAULT_STRATEGY, version, stream_size);
741 /* To do: ignore strm->next_in if we use it as window */
744 /* ========================================================================= */
745 int deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
746 version, stream_size)
758 static char* my_version = ZLIB_VERSION;
761 /* We overlay pending_buf and d_buf+l_buf. This works since the average
762 * output size for (length,distance) codes is <= 24 bits.
765 if (version == Z_NULL || version[0] != my_version[0] ||
766 stream_size != sizeof(z_stream)) {
767 return Z_VERSION_ERROR;
769 if (strm == Z_NULL) return Z_STREAM_ERROR;
773 if (strm->zalloc == Z_NULL) {
774 strm->zalloc = zcalloc;
775 strm->opaque = (voidpf)0;
777 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
780 if (level == Z_DEFAULT_COMPRESSION) level = 6;
782 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
784 windowBits = -windowBits;
786 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
787 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
788 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
789 return Z_STREAM_ERROR;
791 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
792 if (s == Z_NULL) return Z_MEM_ERROR;
793 strm->state = (struct internal_state FAR *)s;
796 s->noheader = noheader;
797 s->w_bits = windowBits;
798 s->w_size = 1 << s->w_bits;
799 s->w_mask = s->w_size - 1;
801 s->hash_bits = memLevel + 7;
802 s->hash_size = 1 << s->hash_bits;
803 s->hash_mask = s->hash_size - 1;
804 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
806 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
807 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
808 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
810 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
812 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
813 s->pending_buf = (uchf *) overlay;
814 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
816 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
817 s->pending_buf == Z_NULL) {
818 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR);
822 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
823 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
826 s->strategy = strategy;
827 s->method = (Byte)method;
829 return deflateReset(strm);
832 /* ========================================================================= */
833 int deflateSetDictionary (strm, dictionary, dictLength)
835 const Bytef *dictionary;
839 uInt length = dictLength;
843 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
844 return Z_STREAM_ERROR;
846 s = (deflate_state *) strm->state;
847 if (s->status != INIT_STATE) return Z_STREAM_ERROR;
849 strm->adler = adler32(strm->adler, dictionary, dictLength);
851 if (length < MIN_MATCH) return Z_OK;
852 if (length > MAX_DIST(s)) {
853 length = MAX_DIST(s);
854 #ifndef USE_DICT_HEAD
855 dictionary += dictLength - length; /* use the tail of the dictionary */
858 zmemcpy((charf *)s->window, dictionary, length);
859 s->strstart = length;
860 s->block_start = (long)length;
862 /* Insert all strings in the hash table (except for the last two bytes).
863 * s->lookahead stays null, so s->ins_h will be recomputed at the next
864 * call of fill_window.
866 s->ins_h = s->window[0];
867 UPDATE_HASH(s, s->ins_h, s->window[1]);
868 for (n = 0; n <= length - MIN_MATCH; n++) {
869 INSERT_STRING(s, n, hash_head);
871 if (hash_head) hash_head = 0; /* to make compiler happy */
875 /* ========================================================================= */
876 int deflateReset (strm)
881 if (strm == Z_NULL || strm->state == Z_NULL ||
882 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
884 strm->total_in = strm->total_out = 0;
885 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
886 strm->data_type = Z_UNKNOWN;
888 s = (deflate_state *)strm->state;
890 s->pending_out = s->pending_buf;
892 if (s->noheader < 0) {
893 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
895 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
897 s->last_flush = Z_NO_FLUSH;
905 /* ========================================================================= */
906 int deflateParams(strm, level, strategy)
915 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
916 s = (deflate_state *) strm->state;
918 if (level == Z_DEFAULT_COMPRESSION) {
921 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
922 return Z_STREAM_ERROR;
924 func = configuration_table[s->level].func;
926 if (func != configuration_table[level].func && strm->total_in != 0) {
927 /* Flush the last buffer: */
928 err = deflate(strm, Z_PARTIAL_FLUSH);
930 if (s->level != level) {
932 s->max_lazy_match = configuration_table[level].max_lazy;
933 s->good_match = configuration_table[level].good_length;
934 s->nice_match = configuration_table[level].nice_length;
935 s->max_chain_length = configuration_table[level].max_chain;
937 s->strategy = strategy;
941 /* =========================================================================
942 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
943 * IN assertion: the stream state is correct and there is enough room in
946 local void putShortMSB (s, b)
950 put_byte(s, (Byte)(b >> 8));
951 put_byte(s, (Byte)(b & 0xff));
954 /* =========================================================================
955 * Flush as much pending output as possible. All deflate() output goes
956 * through this function so some applications may wish to modify it
957 * to avoid allocating a large strm->next_out buffer and copying into it.
958 * (See also read_buf()).
960 local void flush_pending(strm)
963 deflate_state *s = (deflate_state *) strm->state;
964 unsigned len = s->pending;
966 if (len > strm->avail_out) len = strm->avail_out;
967 if (len == 0) return;
969 if (strm->next_out != Z_NULL) {
970 zmemcpy(strm->next_out, s->pending_out, len);
971 strm->next_out += len;
973 s->pending_out += len;
974 strm->total_out += len;
975 strm->avail_out -= len;
977 if (s->pending == 0) {
978 s->pending_out = s->pending_buf;
982 /* ========================================================================= */
983 int deflate (strm, flush)
987 int old_flush; /* value of flush param for previous deflate call */
990 if (strm == Z_NULL || strm->state == Z_NULL ||
991 flush > Z_FINISH || flush < 0) {
992 return Z_STREAM_ERROR;
994 s = (deflate_state *) strm->state;
996 if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
997 (s->status == FINISH_STATE && flush != Z_FINISH)) {
998 ERR_RETURN(strm, Z_STREAM_ERROR);
1000 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
1002 s->strm = strm; /* just in case */
1003 old_flush = s->last_flush;
1004 s->last_flush = flush;
1006 /* Write the zlib header */
1007 if (s->status == INIT_STATE) {
1009 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1010 uInt level_flags = (s->level-1) >> 1;
1012 if (level_flags > 3) level_flags = 3;
1013 header |= (level_flags << 6);
1014 if (s->strstart != 0) header |= PRESET_DICT;
1015 header += 31 - (header % 31);
1017 s->status = BUSY_STATE;
1018 putShortMSB(s, header);
1020 /* Save the adler32 of the preset dictionary: */
1021 if (s->strstart != 0) {
1022 putShortMSB(s, (uInt)(strm->adler >> 16));
1023 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1028 /* Flush as much pending output as possible */
1029 if (s->pending != 0) {
1030 flush_pending(strm);
1031 if (strm->avail_out == 0) {
1032 /* Since avail_out is 0, deflate will be called again with
1033 * more output space, but possibly with both pending and
1034 * avail_in equal to zero. There won't be anything to do,
1035 * but this is not an error situation so make sure we
1036 * return OK instead of BUF_ERROR at next call of deflate:
1042 /* Make sure there is something to do and avoid duplicate consecutive
1043 * flushes. For repeated and useless calls with Z_FINISH, we keep
1044 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1046 } else if (strm->avail_in == 0 && flush <= old_flush &&
1047 flush != Z_FINISH) {
1048 ERR_RETURN(strm, Z_BUF_ERROR);
1051 /* User must not provide more input after the first FINISH: */
1052 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1053 ERR_RETURN(strm, Z_BUF_ERROR);
1056 /* Start a new block or continue the current one.
1058 if (strm->avail_in != 0 || s->lookahead != 0 ||
1059 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1062 bstate = (*(configuration_table[s->level].func))(s, flush);
1064 if (bstate == finish_started || bstate == finish_done) {
1065 s->status = FINISH_STATE;
1067 if (bstate == need_more || bstate == finish_started) {
1068 if (strm->avail_out == 0) {
1069 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1072 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1073 * of deflate should use the same flush parameter to make sure
1074 * that the flush is complete. So we don't have to output an
1075 * empty block here, this will be done at next call. This also
1076 * ensures that for a very small output buffer, we emit at most
1080 if (bstate == block_done) {
1081 if (flush == Z_PARTIAL_FLUSH) {
1083 } else if (flush == Z_PACKET_FLUSH) {
1084 /* Output just the 3-bit `stored' block type value,
1085 but not a zero length. */
1086 _tr_stored_type_only(s);
1087 } else { /* FULL_FLUSH or SYNC_FLUSH */
1088 _tr_stored_block(s, (char*)0, 0L, 0);
1089 /* For a full flush, this empty block will be recognized
1090 * as a special marker by inflate_sync().
1092 if (flush == Z_FULL_FLUSH) {
1093 CLEAR_HASH(s); /* forget history */
1096 flush_pending(strm);
1097 if (strm->avail_out == 0) {
1098 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1103 Assert(strm->avail_out > 0, "bug2");
1105 if (flush != Z_FINISH) return Z_OK;
1106 if (s->noheader) return Z_STREAM_END;
1108 /* Write the zlib trailer (adler32) */
1109 putShortMSB(s, (uInt)(strm->adler >> 16));
1110 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1111 flush_pending(strm);
1112 /* If avail_out is zero, the application will call deflate again
1113 * to flush the rest.
1115 s->noheader = -1; /* write the trailer only once! */
1116 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1119 /* ========================================================================= */
1120 int deflateEnd (strm)
1126 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1127 s = (deflate_state *) strm->state;
1130 if (status != INIT_STATE && status != BUSY_STATE &&
1131 status != FINISH_STATE) {
1132 return Z_STREAM_ERROR;
1135 /* Deallocate in reverse order of allocations: */
1136 TRY_FREE(strm, s->pending_buf);
1137 TRY_FREE(strm, s->head);
1138 TRY_FREE(strm, s->prev);
1139 TRY_FREE(strm, s->window);
1142 strm->state = Z_NULL;
1144 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1147 /* =========================================================================
1148 * Copy the source state to the destination state.
1150 int deflateCopy (dest, source)
1158 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
1159 return Z_STREAM_ERROR;
1160 ss = (deflate_state *) source->state;
1162 zmemcpy(dest, source, sizeof(*dest));
1164 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1165 if (ds == Z_NULL) return Z_MEM_ERROR;
1166 dest->state = (struct internal_state FAR *) ds;
1167 zmemcpy(ds, ss, sizeof(*ds));
1170 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1171 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1172 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1173 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1174 ds->pending_buf = (uchf *) overlay;
1176 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1177 ds->pending_buf == Z_NULL) {
1181 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */
1182 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1183 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1184 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1185 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1187 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1188 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1189 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1191 ds->l_desc.dyn_tree = ds->dyn_ltree;
1192 ds->d_desc.dyn_tree = ds->dyn_dtree;
1193 ds->bl_desc.dyn_tree = ds->bl_tree;
1198 /* ===========================================================================
1199 * Return the number of bytes of output which are immediately available
1200 * for output from the decompressor.
1202 int deflateOutputPending (strm)
1205 if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1207 return ((deflate_state *)(strm->state))->pending;
1210 /* ===========================================================================
1211 * Read a new buffer from the current input stream, update the adler32
1212 * and total number of bytes read. All deflate() input goes through
1213 * this function so some applications may wish to modify it to avoid
1214 * allocating a large strm->next_in buffer and copying from it.
1215 * (See also flush_pending()).
1217 local int read_buf(strm, buf, size)
1222 unsigned len = strm->avail_in;
1224 if (len > size) len = size;
1225 if (len == 0) return 0;
1227 strm->avail_in -= len;
1229 if (!((deflate_state *)(strm->state))->noheader) {
1230 strm->adler = adler32(strm->adler, strm->next_in, len);
1232 zmemcpy(buf, strm->next_in, len);
1233 strm->next_in += len;
1234 strm->total_in += len;
1239 /* ===========================================================================
1240 * Initialize the "longest match" routines for a new zlib stream
1242 local void lm_init (s)
1245 s->window_size = (ulg)2L*s->w_size;
1249 /* Set the default configuration parameters:
1251 s->max_lazy_match = configuration_table[s->level].max_lazy;
1252 s->good_match = configuration_table[s->level].good_length;
1253 s->nice_match = configuration_table[s->level].nice_length;
1254 s->max_chain_length = configuration_table[s->level].max_chain;
1257 s->block_start = 0L;
1259 s->match_length = s->prev_length = MIN_MATCH-1;
1260 s->match_available = 0;
1263 match_init(); /* initialize the asm code */
1267 /* ===========================================================================
1268 * Set match_start to the longest match starting at the given string and
1269 * return its length. Matches shorter or equal to prev_length are discarded,
1270 * in which case the result is equal to prev_length and match_start is
1272 * IN assertions: cur_match is the head of the hash chain for the current
1273 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1274 * OUT assertion: the match length is not greater than s->lookahead.
1277 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1278 * match.S. The code will be functionally equivalent.
1280 local uInt longest_match(s, cur_match)
1282 IPos cur_match; /* current match */
1284 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1285 register Bytef *scan = s->window + s->strstart; /* current string */
1286 register Bytef *match; /* matched string */
1287 register int len; /* length of current match */
1288 int best_len = s->prev_length; /* best match length so far */
1289 int nice_match = s->nice_match; /* stop if match long enough */
1290 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1291 s->strstart - (IPos)MAX_DIST(s) : NIL;
1292 /* Stop when cur_match becomes <= limit. To simplify the code,
1293 * we prevent matches with the string of window index 0.
1295 Posf *prev = s->prev;
1296 uInt wmask = s->w_mask;
1299 /* Compare two bytes at a time. Note: this is not always beneficial.
1300 * Try with and without -DUNALIGNED_OK to check.
1302 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1303 register ush scan_start = *(ushf*)scan;
1304 register ush scan_end = *(ushf*)(scan+best_len-1);
1306 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1307 register Byte scan_end1 = scan[best_len-1];
1308 register Byte scan_end = scan[best_len];
1311 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1312 * It is easy to get rid of this optimization if necessary.
1314 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1316 /* Do not waste too much time if we already have a good match: */
1317 if (s->prev_length >= s->good_match) {
1320 /* Do not look for matches beyond the end of the input. This is necessary
1321 * to make deflate deterministic.
1323 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1325 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1328 Assert(cur_match < s->strstart, "no future");
1329 match = s->window + cur_match;
1331 /* Skip to next match if the match length cannot increase
1332 * or if the match length is less than 2:
1334 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1335 /* This code assumes sizeof(unsigned short) == 2. Do not use
1336 * UNALIGNED_OK if your compiler uses a different size.
1338 if (*(ushf*)(match+best_len-1) != scan_end ||
1339 *(ushf*)match != scan_start) continue;
1341 /* It is not necessary to compare scan[2] and match[2] since they are
1342 * always equal when the other bytes match, given that the hash keys
1343 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1344 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1345 * lookahead only every 4th comparison; the 128th check will be made
1346 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1347 * necessary to put more guard bytes at the end of the window, or
1348 * to check more often for insufficient lookahead.
1350 Assert(scan[2] == match[2], "scan[2]?");
1353 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1354 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1355 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1356 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1358 /* The funny "do {}" generates better code on most compilers */
1360 /* Here, scan <= window+strstart+257 */
1361 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1362 if (*scan == *match) scan++;
1364 len = (MAX_MATCH - 1) - (int)(strend-scan);
1365 scan = strend - (MAX_MATCH-1);
1367 #else /* UNALIGNED_OK */
1369 if (match[best_len] != scan_end ||
1370 match[best_len-1] != scan_end1 ||
1372 *++match != scan[1]) continue;
1374 /* The check at best_len-1 can be removed because it will be made
1375 * again later. (This heuristic is not always a win.)
1376 * It is not necessary to compare scan[2] and match[2] since they
1377 * are always equal when the other bytes match, given that
1378 * the hash keys are equal and that HASH_BITS >= 8.
1381 Assert(*scan == *match, "match[2]?");
1383 /* We check for insufficient lookahead only every 8th comparison;
1384 * the 256th check will be made at strstart+258.
1387 } while (*++scan == *++match && *++scan == *++match &&
1388 *++scan == *++match && *++scan == *++match &&
1389 *++scan == *++match && *++scan == *++match &&
1390 *++scan == *++match && *++scan == *++match &&
1393 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1395 len = MAX_MATCH - (int)(strend - scan);
1396 scan = strend - MAX_MATCH;
1398 #endif /* UNALIGNED_OK */
1400 if (len > best_len) {
1401 s->match_start = cur_match;
1403 if (len >= nice_match) break;
1405 scan_end = *(ushf*)(scan+best_len-1);
1407 scan_end1 = scan[best_len-1];
1408 scan_end = scan[best_len];
1411 } while ((cur_match = prev[cur_match & wmask]) > limit
1412 && --chain_length != 0);
1414 if ((uInt)best_len <= s->lookahead) return best_len;
1415 return s->lookahead;
1420 /* ===========================================================================
1421 * Check that the match at match_start is indeed a match.
1423 local void check_match(s, start, match, length)
1428 /* check that the match is indeed a match */
1429 if (zmemcmp((charf *)s->window + match,
1430 (charf *)s->window + start, length) != EQUAL) {
1431 fprintf(stderr, " start %u, match %u, length %d\n",
1432 start, match, length);
1434 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1435 } while (--length != 0);
1436 z_error("invalid match");
1438 if (z_verbose > 1) {
1439 fprintf(stderr,"\\[%d,%d]", start-match, length);
1440 do { putc(s->window[start++], stderr); } while (--length != 0);
1444 # define check_match(s, start, match, length)
1447 /* ===========================================================================
1448 * Fill the window when the lookahead becomes insufficient.
1449 * Updates strstart and lookahead.
1451 * IN assertion: lookahead < MIN_LOOKAHEAD
1452 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1453 * At least one byte has been read, or avail_in == 0; reads are
1454 * performed for at least two bytes (required for the zip translate_eol
1455 * option -- not supported here).
1457 local void fill_window(s)
1460 register unsigned n, m;
1462 unsigned more; /* Amount of free space at the end of the window. */
1463 uInt wsize = s->w_size;
1466 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1468 /* Deal with !@#$% 64K limit: */
1469 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1472 } else if (more == (unsigned)(-1)) {
1473 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1474 * and lookahead == 1 (input done one byte at time)
1478 /* If the window is almost full and there is insufficient lookahead,
1479 * move the upper half to the lower one to make room in the upper half.
1481 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1483 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1485 s->match_start -= wsize;
1486 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1487 s->block_start -= (long) wsize;
1489 /* Slide the hash table (could be avoided with 32 bit values
1490 at the expense of memory usage). We slide even when level == 0
1491 to keep the hash table consistent if we switch back to level > 0
1492 later. (Using level 0 permanently is not an optimal usage of
1493 zlib, so we don't care about this pathological case.)
1499 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1506 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1507 /* If n is not on any hash chain, prev[n] is garbage but
1508 * its value will never be used.
1513 if (s->strm->avail_in == 0) return;
1515 /* If there was no sliding:
1516 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1517 * more == window_size - lookahead - strstart
1518 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1519 * => more >= window_size - 2*WSIZE + 2
1520 * In the BIG_MEM or MMAP case (not yet supported),
1521 * window_size == input_size + MIN_LOOKAHEAD &&
1522 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1523 * Otherwise, window_size == 2*WSIZE so more >= 2.
1524 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1526 Assert(more >= 2, "more < 2");
1528 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1532 /* Initialize the hash value now that we have some input: */
1533 if (s->lookahead >= MIN_MATCH) {
1534 s->ins_h = s->window[s->strstart];
1535 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1537 Call UPDATE_HASH() MIN_MATCH-3 more times
1540 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1541 * but this is not important since only literal bytes will be emitted.
1544 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1547 /* ===========================================================================
1548 * Flush the current block, with given end-of-file flag.
1549 * IN assertion: strstart is set to the end of the current match.
1551 #define FLUSH_BLOCK_ONLY(s, eof) { \
1552 _tr_flush_block(s, (s->block_start >= 0L ? \
1553 (charf *)&s->window[(unsigned)s->block_start] : \
1555 (ulg)((long)s->strstart - s->block_start), \
1557 s->block_start = s->strstart; \
1558 flush_pending(s->strm); \
1559 Tracev((stderr,"[FLUSH]")); \
1562 /* Same but force premature exit if necessary. */
1563 #define FLUSH_BLOCK(s, eof) { \
1564 FLUSH_BLOCK_ONLY(s, eof); \
1565 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1568 /* ===========================================================================
1569 * Copy without compression as much as possible from the input stream, return
1570 * the current block state.
1571 * This function does not insert new strings in the dictionary since
1572 * uncompressible data is probably not useful. This function is used
1573 * only for the level=0 compression option.
1574 * NOTE: this function should be optimized to avoid extra copying from
1575 * window to pending_buf.
1577 local block_state deflate_stored(s, flush)
1581 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1582 * to pending_buf_size, and each stored block has a 5 byte header:
1584 ulg max_block_size = 0xffff;
1587 if (max_block_size > s->pending_buf_size - 5) {
1588 max_block_size = s->pending_buf_size - 5;
1591 /* Copy as much as possible from input to output: */
1593 /* Fill the window as much as possible: */
1594 if (s->lookahead <= 1) {
1596 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1597 s->block_start >= (long)s->w_size, "slide too late");
1600 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1602 if (s->lookahead == 0) break; /* flush the current block */
1604 Assert(s->block_start >= 0L, "block gone");
1606 s->strstart += s->lookahead;
1609 /* Emit a stored block if pending_buf will be full: */
1610 max_start = s->block_start + max_block_size;
1611 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1612 /* strstart == 0 is possible when wraparound on 16-bit machine */
1613 s->lookahead = (uInt)(s->strstart - max_start);
1614 s->strstart = (uInt)max_start;
1617 /* Flush if we may have to slide, otherwise block_start may become
1618 * negative and the data will be gone:
1620 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1624 FLUSH_BLOCK(s, flush == Z_FINISH);
1625 return flush == Z_FINISH ? finish_done : block_done;
1628 /* ===========================================================================
1629 * Compress as much as possible from the input stream, return the current
1631 * This function does not perform lazy evaluation of matches and inserts
1632 * new strings in the dictionary only for unmatched strings or for short
1633 * matches. It is used only for the fast compression options.
1635 local block_state deflate_fast(s, flush)
1639 IPos hash_head = NIL; /* head of the hash chain */
1640 int bflush; /* set if current block must be flushed */
1643 /* Make sure that we always have enough lookahead, except
1644 * at the end of the input file. We need MAX_MATCH bytes
1645 * for the next match, plus MIN_MATCH bytes to insert the
1646 * string following the next match.
1648 if (s->lookahead < MIN_LOOKAHEAD) {
1650 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1653 if (s->lookahead == 0) break; /* flush the current block */
1656 /* Insert the string window[strstart .. strstart+2] in the
1657 * dictionary, and set hash_head to the head of the hash chain:
1659 if (s->lookahead >= MIN_MATCH) {
1660 INSERT_STRING(s, s->strstart, hash_head);
1663 /* Find the longest match, discarding those <= prev_length.
1664 * At this point we have always match_length < MIN_MATCH
1666 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1667 /* To simplify the code, we prevent matches with the string
1668 * of window index 0 (in particular we have to avoid a match
1669 * of the string with itself at the start of the input file).
1671 if (s->strategy != Z_HUFFMAN_ONLY) {
1672 s->match_length = longest_match (s, hash_head);
1674 /* longest_match() sets match_start */
1676 if (s->match_length >= MIN_MATCH) {
1677 check_match(s, s->strstart, s->match_start, s->match_length);
1679 bflush = _tr_tally(s, s->strstart - s->match_start,
1680 s->match_length - MIN_MATCH);
1682 s->lookahead -= s->match_length;
1684 /* Insert new strings in the hash table only if the match length
1685 * is not too large. This saves time but degrades compression.
1687 if (s->match_length <= s->max_insert_length &&
1688 s->lookahead >= MIN_MATCH) {
1689 s->match_length--; /* string at strstart already in hash table */
1692 INSERT_STRING(s, s->strstart, hash_head);
1693 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1694 * always MIN_MATCH bytes ahead.
1696 } while (--s->match_length != 0);
1699 s->strstart += s->match_length;
1700 s->match_length = 0;
1701 s->ins_h = s->window[s->strstart];
1702 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1704 Call UPDATE_HASH() MIN_MATCH-3 more times
1706 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1707 * matter since it will be recomputed at next deflate call.
1711 /* No match, output a literal byte */
1712 Tracevv((stderr,"%c", s->window[s->strstart]));
1713 bflush = _tr_tally (s, 0, s->window[s->strstart]);
1717 if (bflush) FLUSH_BLOCK(s, 0);
1719 FLUSH_BLOCK(s, flush == Z_FINISH);
1720 return flush == Z_FINISH ? finish_done : block_done;
1723 /* ===========================================================================
1724 * Same as above, but achieves better compression. We use a lazy
1725 * evaluation for matches: a match is finally adopted only if there is
1726 * no better match at the next window position.
1728 local block_state deflate_slow(s, flush)
1732 IPos hash_head = NIL; /* head of hash chain */
1733 int bflush; /* set if current block must be flushed */
1735 /* Process the input block. */
1737 /* Make sure that we always have enough lookahead, except
1738 * at the end of the input file. We need MAX_MATCH bytes
1739 * for the next match, plus MIN_MATCH bytes to insert the
1740 * string following the next match.
1742 if (s->lookahead < MIN_LOOKAHEAD) {
1744 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1747 if (s->lookahead == 0) break; /* flush the current block */
1750 /* Insert the string window[strstart .. strstart+2] in the
1751 * dictionary, and set hash_head to the head of the hash chain:
1753 if (s->lookahead >= MIN_MATCH) {
1754 INSERT_STRING(s, s->strstart, hash_head);
1757 /* Find the longest match, discarding those <= prev_length.
1759 s->prev_length = s->match_length, s->prev_match = s->match_start;
1760 s->match_length = MIN_MATCH-1;
1762 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1763 s->strstart - hash_head <= MAX_DIST(s)) {
1764 /* To simplify the code, we prevent matches with the string
1765 * of window index 0 (in particular we have to avoid a match
1766 * of the string with itself at the start of the input file).
1768 if (s->strategy != Z_HUFFMAN_ONLY) {
1769 s->match_length = longest_match (s, hash_head);
1771 /* longest_match() sets match_start */
1773 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1774 (s->match_length == MIN_MATCH &&
1775 s->strstart - s->match_start > TOO_FAR))) {
1777 /* If prev_match is also MIN_MATCH, match_start is garbage
1778 * but we will ignore the current match anyway.
1780 s->match_length = MIN_MATCH-1;
1783 /* If there was a match at the previous step and the current
1784 * match is not better, output the previous match:
1786 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1787 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1788 /* Do not insert strings in hash table beyond this. */
1790 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1792 bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
1793 s->prev_length - MIN_MATCH);
1795 /* Insert in hash table all strings up to the end of the match.
1796 * strstart-1 and strstart are already inserted. If there is not
1797 * enough lookahead, the last two strings are not inserted in
1800 s->lookahead -= s->prev_length-1;
1801 s->prev_length -= 2;
1803 if (++s->strstart <= max_insert) {
1804 INSERT_STRING(s, s->strstart, hash_head);
1806 } while (--s->prev_length != 0);
1807 s->match_available = 0;
1808 s->match_length = MIN_MATCH-1;
1811 if (bflush) FLUSH_BLOCK(s, 0);
1813 } else if (s->match_available) {
1814 /* If there was no match at the previous position, output a
1815 * single literal. If there was a match but the current match
1816 * is longer, truncate the previous match to a single literal.
1818 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1819 if (_tr_tally (s, 0, s->window[s->strstart-1])) {
1820 FLUSH_BLOCK_ONLY(s, 0);
1824 if (s->strm->avail_out == 0) return need_more;
1826 /* There is no previous match to compare with, wait for
1827 * the next step to decide.
1829 s->match_available = 1;
1834 Assert (flush != Z_NO_FLUSH, "no flush?");
1835 if (s->match_available) {
1836 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1837 _tr_tally (s, 0, s->window[s->strstart-1]);
1838 s->match_available = 0;
1840 FLUSH_BLOCK(s, flush == Z_FINISH);
1841 return flush == Z_FINISH ? finish_done : block_done;
1846 /* trees.c -- output deflated data using Huffman coding
1847 * Copyright (C) 1995-1996 Jean-loup Gailly
1848 * For conditions of distribution and use, see copyright notice in zlib.h
1854 * The "deflation" process uses several Huffman trees. The more
1855 * common source values are represented by shorter bit sequences.
1857 * Each code tree is stored in a compressed form which is itself
1858 * a Huffman encoding of the lengths of all the code strings (in
1859 * ascending order by source values). The actual code strings are
1860 * reconstructed from the lengths in the inflate process, as described
1861 * in the deflate specification.
1865 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1866 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1869 * Data Compression: Methods and Theory, pp. 49-50.
1870 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1874 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1877 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
1879 /* #include "deflate.h" */
1885 /* ===========================================================================
1889 #define MAX_BL_BITS 7
1890 /* Bit length codes must not exceed MAX_BL_BITS bits */
1892 #define END_BLOCK 256
1893 /* end of block literal code */
1896 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1898 #define REPZ_3_10 17
1899 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1901 #define REPZ_11_138 18
1902 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1904 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1905 = {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};
1907 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1908 = {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};
1910 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1911 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1913 local uch bl_order[BL_CODES]
1914 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1915 /* The lengths of the bit length codes are sent in order of decreasing
1916 * probability, to avoid transmitting the lengths for unused bit length codes.
1919 #define Buf_size (8 * 2*sizeof(char))
1920 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1921 * more than 16 bits on some systems.)
1924 /* ===========================================================================
1925 * Local data. These are initialized only once.
1928 local ct_data static_ltree[L_CODES+2];
1929 /* The static literal tree. Since the bit lengths are imposed, there is no
1930 * need for the L_CODES extra codes used during heap construction. However
1931 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
1935 local ct_data static_dtree[D_CODES];
1936 /* The static distance tree. (Actually a trivial tree since all codes use
1940 local uch dist_code[512];
1941 /* distance codes. The first 256 values correspond to the distances
1942 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1943 * the 15 bit distances.
1946 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1947 /* length code for each normalized match length (0 == MIN_MATCH) */
1949 local int base_length[LENGTH_CODES];
1950 /* First normalized length for each code (0 = MIN_MATCH) */
1952 local int base_dist[D_CODES];
1953 /* First normalized distance for each code (0 = distance of 1) */
1955 struct static_tree_desc_s {
1956 ct_data *static_tree; /* static tree or NULL */
1957 intf *extra_bits; /* extra bits for each code or NULL */
1958 int extra_base; /* base index for extra_bits */
1959 int elems; /* max number of elements in the tree */
1960 int max_length; /* max bit length for the codes */
1963 local static_tree_desc static_l_desc =
1964 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1966 local static_tree_desc static_d_desc =
1967 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1969 local static_tree_desc static_bl_desc =
1970 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1972 /* ===========================================================================
1973 * Local (static) routines in this file.
1976 local void tr_static_init OF((void));
1977 local void init_block OF((deflate_state *s));
1978 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1979 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1980 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1981 local void build_tree OF((deflate_state *s, tree_desc *desc));
1982 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1983 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1984 local int build_bl_tree OF((deflate_state *s));
1985 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1987 local void compress_block OF((deflate_state *s, ct_data *ltree,
1989 local void set_data_type OF((deflate_state *s));
1990 local unsigned bi_reverse OF((unsigned value, int length));
1991 local void bi_windup OF((deflate_state *s));
1992 local void bi_flush OF((deflate_state *s));
1993 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1997 # define send_code(s, c, tree) send_bits(s, tree[(c)].Code, tree[(c)].Len)
1998 /* Send a code of the given tree. c and tree must not have side effects */
2000 #else /* DEBUG_ZLIB */
2001 # define send_code(s, c, tree) \
2002 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
2003 send_bits(s, tree[c].Code, tree[c].Len); }
2006 #define d_code(dist) \
2007 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
2008 /* Mapping from a distance to a distance code. dist is the distance - 1 and
2009 * must not have side effects. dist_code[256] and dist_code[257] are never
2013 /* ===========================================================================
2014 * Output a short LSB first on the stream.
2015 * IN assertion: there is enough room in pendingBuf.
2017 #define put_short(s, w) { \
2018 put_byte(s, (uch)((w) & 0xff)); \
2019 put_byte(s, (uch)((ush)(w) >> 8)); \
2022 /* ===========================================================================
2023 * Send a value on a given number of bits.
2024 * IN assertion: length <= 16 and value fits in length bits.
2027 local void send_bits OF((deflate_state *s, int value, int length));
2029 local void send_bits(s, value, length)
2031 int value; /* value to send */
2032 int length; /* number of bits */
2034 Tracevv((stderr," l %2d v %4x ", length, value));
2035 Assert(length > 0 && length <= 15, "invalid length");
2036 s->bits_sent += (ulg)length;
2038 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2039 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2040 * unused bits in value.
2042 if (s->bi_valid > (int)Buf_size - length) {
2043 s->bi_buf |= (value << s->bi_valid);
2044 put_short(s, s->bi_buf);
2045 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2046 s->bi_valid += length - Buf_size;
2048 s->bi_buf |= value << s->bi_valid;
2049 s->bi_valid += length;
2052 #else /* !DEBUG_ZLIB */
2054 #define send_bits(s, value, length) \
2055 { int len = (length);\
2056 if ((s)->bi_valid > (int)Buf_size - len) {\
2058 (s)->bi_buf |= (val << (s)->bi_valid);\
2059 put_short((s), (s)->bi_buf);\
2060 (s)->bi_buf = (ush)val >> (Buf_size - (s)->bi_valid);\
2061 (s)->bi_valid += len - Buf_size;\
2063 (s)->bi_buf |= (value) << (s)->bi_valid;\
2064 (s)->bi_valid += len;\
2067 #endif /* DEBUG_ZLIB */
2069 /* the arguments must not have side effects */
2071 /* ===========================================================================
2072 * Initialize the various 'constant' tables. In a multi-threaded environment,
2073 * this function may be called by two threads concurrently, but this is
2074 * harmless since both invocations do exactly the same thing.
2076 local void tr_static_init()
2078 static int static_init_done = 0;
2079 int n; /* iterates over tree elements */
2080 int bits; /* bit counter */
2081 int length; /* length value */
2082 int code; /* code value */
2083 int dist; /* distance index */
2084 ush bl_count[MAX_BITS+1];
2085 /* number of codes at each bit length for an optimal tree */
2087 if (static_init_done) return;
2089 /* Initialize the mapping length (0..255) -> length code (0..28) */
2091 for (code = 0; code < LENGTH_CODES-1; code++) {
2092 base_length[code] = length;
2093 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2094 length_code[length++] = (uch)code;
2097 Assert (length == 256, "tr_static_init: length != 256");
2098 /* Note that the length 255 (match length 258) can be represented
2099 * in two different ways: code 284 + 5 bits or code 285, so we
2100 * overwrite length_code[255] to use the best encoding:
2102 length_code[length-1] = (uch)code;
2104 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2106 for (code = 0 ; code < 16; code++) {
2107 base_dist[code] = dist;
2108 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2109 dist_code[dist++] = (uch)code;
2112 Assert (dist == 256, "tr_static_init: dist != 256");
2113 dist >>= 7; /* from now on, all distances are divided by 128 */
2114 for ( ; code < D_CODES; code++) {
2115 base_dist[code] = dist << 7;
2116 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2117 dist_code[256 + dist++] = (uch)code;
2120 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2122 /* Construct the codes of the static literal tree */
2123 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2125 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2126 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2127 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2128 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2129 /* Codes 286 and 287 do not exist, but we must include them in the
2130 * tree construction to get a canonical Huffman tree (longest code
2133 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2135 /* The static distance tree is trivial: */
2136 for (n = 0; n < D_CODES; n++) {
2137 static_dtree[n].Len = 5;
2138 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2140 static_init_done = 1;
2143 /* ===========================================================================
2144 * Initialize the tree data structures for a new zlib stream.
2151 s->compressed_len = 0L;
2153 s->l_desc.dyn_tree = s->dyn_ltree;
2154 s->l_desc.stat_desc = &static_l_desc;
2156 s->d_desc.dyn_tree = s->dyn_dtree;
2157 s->d_desc.stat_desc = &static_d_desc;
2159 s->bl_desc.dyn_tree = s->bl_tree;
2160 s->bl_desc.stat_desc = &static_bl_desc;
2164 s->last_eob_len = 8; /* enough lookahead for inflate */
2169 /* Initialize the first block of the first file: */
2173 /* ===========================================================================
2174 * Initialize a new block.
2176 local void init_block(s)
2179 int n; /* iterates over tree elements */
2181 /* Initialize the trees. */
2182 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2183 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2184 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2186 s->dyn_ltree[END_BLOCK].Freq = 1;
2187 s->opt_len = s->static_len = 0L;
2188 s->last_lit = s->matches = 0;
2192 /* Index within the heap array of least frequent node in the Huffman tree */
2195 /* ===========================================================================
2196 * Remove the smallest element from the heap and recreate the heap with
2197 * one less element. Updates heap and heap_len.
2199 #define pqremove(s, tree, top) \
2201 top = s->heap[SMALLEST]; \
2202 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2203 pqdownheap(s, tree, SMALLEST); \
2206 /* ===========================================================================
2207 * Compares to subtrees, using the tree depth as tie breaker when
2208 * the subtrees have equal frequency. This minimizes the worst case length.
2210 #define smaller(tree, n, m, depth) \
2211 (tree[n].Freq < tree[m].Freq || \
2212 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2214 /* ===========================================================================
2215 * Restore the heap property by moving down the tree starting at node k,
2216 * exchanging a node with the smallest of its two sons if necessary, stopping
2217 * when the heap property is re-established (each father smaller than its
2220 local void pqdownheap(s, tree, k)
2222 ct_data *tree; /* the tree to restore */
2223 int k; /* node to move down */
2226 int j = k << 1; /* left son of k */
2227 while (j <= s->heap_len) {
2228 /* Set j to the smallest of the two sons: */
2229 if (j < s->heap_len &&
2230 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2233 /* Exit if v is smaller than both sons */
2234 if (smaller(tree, v, s->heap[j], s->depth)) break;
2236 /* Exchange v with the smallest son */
2237 s->heap[k] = s->heap[j]; k = j;
2239 /* And continue down the tree, setting j to the left son of k */
2245 /* ===========================================================================
2246 * Compute the optimal bit lengths for a tree and update the total bit length
2247 * for the current block.
2248 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2249 * above are the tree nodes sorted by increasing frequency.
2250 * OUT assertions: the field len is set to the optimal bit length, the
2251 * array bl_count contains the frequencies for each bit length.
2252 * The length opt_len is updated; static_len is also updated if stree is
2255 local void gen_bitlen(s, desc)
2257 tree_desc *desc; /* the tree descriptor */
2259 ct_data *tree = desc->dyn_tree;
2260 int max_code = desc->max_code;
2261 ct_data *stree = desc->stat_desc->static_tree;
2262 intf *extra = desc->stat_desc->extra_bits;
2263 int base = desc->stat_desc->extra_base;
2264 int max_length = desc->stat_desc->max_length;
2265 int h; /* heap index */
2266 int n, m; /* iterate over the tree elements */
2267 int bits; /* bit length */
2268 int xbits; /* extra bits */
2269 ush f; /* frequency */
2270 int overflow = 0; /* number of elements with bit length too large */
2272 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2274 /* In a first pass, compute the optimal bit lengths (which may
2275 * overflow in the case of the bit length tree).
2277 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2279 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2281 bits = tree[tree[n].Dad].Len + 1;
2282 if (bits > max_length) bits = max_length, overflow++;
2283 tree[n].Len = (ush)bits;
2284 /* We overwrite tree[n].Dad which is no longer needed */
2286 if (n > max_code) continue; /* not a leaf node */
2288 s->bl_count[bits]++;
2290 if (n >= base) xbits = extra[n-base];
2292 s->opt_len += (ulg)f * (bits + xbits);
2293 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2295 if (overflow == 0) return;
2297 Trace((stderr,"\nbit length overflow\n"));
2298 /* This happens for example on obj2 and pic of the Calgary corpus */
2300 /* Find the first bit length which could increase: */
2302 bits = max_length-1;
2303 while (s->bl_count[bits] == 0) bits--;
2304 s->bl_count[bits]--; /* move one leaf down the tree */
2305 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2306 s->bl_count[max_length]--;
2307 /* The brother of the overflow item also moves one step up,
2308 * but this does not affect bl_count[max_length]
2311 } while (overflow > 0);
2313 /* Now recompute all bit lengths, scanning in increasing frequency.
2314 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2315 * lengths instead of fixing only the wrong ones. This idea is taken
2316 * from 'ar' written by Haruhiko Okumura.)
2318 for (bits = max_length; bits != 0; bits--) {
2319 n = s->bl_count[bits];
2322 if (m > max_code) continue;
2323 if (tree[m].Len != (unsigned) bits) {
2324 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2325 s->opt_len += ((long)bits - (long)tree[m].Len)
2326 *(long)tree[m].Freq;
2327 tree[m].Len = (ush)bits;
2334 /* ===========================================================================
2335 * Generate the codes for a given tree and bit counts (which need not be
2337 * IN assertion: the array bl_count contains the bit length statistics for
2338 * the given tree and the field len is set for all tree elements.
2339 * OUT assertion: the field code is set for all tree elements of non
2342 local void gen_codes (tree, max_code, bl_count)
2343 ct_data *tree; /* the tree to decorate */
2344 int max_code; /* largest code with non zero frequency */
2345 ushf *bl_count; /* number of codes at each bit length */
2347 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2348 ush code = 0; /* running code value */
2349 int bits; /* bit index */
2350 int n; /* code index */
2352 /* The distribution counts are first used to generate the code values
2353 * without bit reversal.
2355 for (bits = 1; bits <= MAX_BITS; bits++) {
2356 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2358 /* Check that the bit counts in bl_count are consistent. The last code
2361 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2362 "inconsistent bit counts");
2363 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2365 for (n = 0; n <= max_code; n++) {
2366 int len = tree[n].Len;
2367 if (len == 0) continue;
2368 /* Now reverse the bits */
2369 tree[n].Code = bi_reverse(next_code[len]++, len);
2371 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2372 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2376 /* ===========================================================================
2377 * Construct one Huffman tree and assigns the code bit strings and lengths.
2378 * Update the total bit length for the current block.
2379 * IN assertion: the field freq is set for all tree elements.
2380 * OUT assertions: the fields len and code are set to the optimal bit length
2381 * and corresponding code. The length opt_len is updated; static_len is
2382 * also updated if stree is not null. The field max_code is set.
2384 local void build_tree(s, desc)
2386 tree_desc *desc; /* the tree descriptor */
2388 ct_data *tree = desc->dyn_tree;
2389 ct_data *stree = desc->stat_desc->static_tree;
2390 int elems = desc->stat_desc->elems;
2391 int n, m; /* iterate over heap elements */
2392 int max_code = -1; /* largest code with non zero frequency */
2393 int node; /* new node being created */
2395 /* Construct the initial heap, with least frequent element in
2396 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2397 * heap[0] is not used.
2399 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2401 for (n = 0; n < elems; n++) {
2402 if (tree[n].Freq != 0) {
2403 s->heap[++(s->heap_len)] = max_code = n;
2410 /* The pkzip format requires that at least one distance code exists,
2411 * and that at least one bit should be sent even if there is only one
2412 * possible code. So to avoid special checks later on we force at least
2413 * two codes of non zero frequency.
2415 while (s->heap_len < 2) {
2416 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2417 tree[node].Freq = 1;
2419 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2420 /* node is 0 or 1 so it does not have extra bits */
2422 desc->max_code = max_code;
2424 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2425 * establish sub-heaps of increasing lengths:
2427 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2429 /* Construct the Huffman tree by repeatedly combining the least two
2432 node = elems; /* next internal node of the tree */
2434 pqremove(s, tree, n); /* n = node of least frequency */
2435 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2437 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2438 s->heap[--(s->heap_max)] = m;
2440 /* Create a new node father of n and m */
2441 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2442 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2443 tree[n].Dad = tree[m].Dad = (ush)node;
2445 if (tree == s->bl_tree) {
2446 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2447 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2450 /* and insert the new node in the heap */
2451 s->heap[SMALLEST] = node++;
2452 pqdownheap(s, tree, SMALLEST);
2454 } while (s->heap_len >= 2);
2456 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2458 /* At this point, the fields freq and dad are set. We can now
2459 * generate the bit lengths.
2461 gen_bitlen(s, (tree_desc *)desc);
2463 /* The field len is now set, we can generate the bit codes */
2464 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2467 /* ===========================================================================
2468 * Scan a literal or distance tree to determine the frequencies of the codes
2469 * in the bit length tree.
2471 local void scan_tree (s, tree, max_code)
2473 ct_data *tree; /* the tree to be scanned */
2474 int max_code; /* and its largest code of non zero frequency */
2476 int n; /* iterates over all tree elements */
2477 int prevlen = -1; /* last emitted length */
2478 int curlen; /* length of current code */
2479 int nextlen = tree[0].Len; /* length of next code */
2480 int count = 0; /* repeat count of the current code */
2481 int max_count = 7; /* max repeat count */
2482 int min_count = 4; /* min repeat count */
2484 if (nextlen == 0) max_count = 138, min_count = 3;
2485 tree[max_code+1].Len = (ush)0xffff; /* guard */
2487 for (n = 0; n <= max_code; n++) {
2488 curlen = nextlen; nextlen = tree[n+1].Len;
2489 if (++count < max_count && curlen == nextlen) {
2491 } else if (count < min_count) {
2492 s->bl_tree[curlen].Freq += count;
2493 } else if (curlen != 0) {
2494 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2495 s->bl_tree[REP_3_6].Freq++;
2496 } else if (count <= 10) {
2497 s->bl_tree[REPZ_3_10].Freq++;
2499 s->bl_tree[REPZ_11_138].Freq++;
2501 count = 0; prevlen = curlen;
2503 max_count = 138, min_count = 3;
2504 } else if (curlen == nextlen) {
2505 max_count = 6, min_count = 3;
2507 max_count = 7, min_count = 4;
2512 /* ===========================================================================
2513 * Send a literal or distance tree in compressed form, using the codes in
2516 local void send_tree (s, tree, max_code)
2518 ct_data *tree; /* the tree to be scanned */
2519 int max_code; /* and its largest code of non zero frequency */
2521 int n; /* iterates over all tree elements */
2522 int prevlen = -1; /* last emitted length */
2523 int curlen; /* length of current code */
2524 int nextlen = tree[0].Len; /* length of next code */
2525 int count = 0; /* repeat count of the current code */
2526 int max_count = 7; /* max repeat count */
2527 int min_count = 4; /* min repeat count */
2529 /* tree[max_code+1].Len = -1; */ /* guard already set */
2530 if (nextlen == 0) max_count = 138, min_count = 3;
2532 for (n = 0; n <= max_code; n++) {
2533 curlen = nextlen; nextlen = tree[n+1].Len;
2534 if (++count < max_count && curlen == nextlen) {
2536 } else if (count < min_count) {
2537 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2539 } else if (curlen != 0) {
2540 if (curlen != prevlen) {
2541 send_code(s, curlen, s->bl_tree); count--;
2543 Assert(count >= 3 && count <= 6, " 3_6?");
2544 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2546 } else if (count <= 10) {
2547 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2550 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2552 count = 0; prevlen = curlen;
2554 max_count = 138, min_count = 3;
2555 } else if (curlen == nextlen) {
2556 max_count = 6, min_count = 3;
2558 max_count = 7, min_count = 4;
2563 /* ===========================================================================
2564 * Construct the Huffman tree for the bit lengths and return the index in
2565 * bl_order of the last bit length code to send.
2567 local int build_bl_tree(s)
2570 int max_blindex; /* index of last bit length code of non zero freq */
2572 /* Determine the bit length frequencies for literal and distance trees */
2573 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2574 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2576 /* Build the bit length tree: */
2577 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2578 /* opt_len now includes the length of the tree representations, except
2579 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2582 /* Determine the number of bit length codes to send. The pkzip format
2583 * requires that at least 4 bit length codes be sent. (appnote.txt says
2584 * 3 but the actual value used is 4.)
2586 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2587 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2589 /* Update opt_len to include the bit length tree and counts */
2590 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2591 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2592 s->opt_len, s->static_len));
2597 /* ===========================================================================
2598 * Send the header for a block using dynamic Huffman trees: the counts, the
2599 * lengths of the bit length codes, the literal tree and the distance tree.
2600 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2602 local void send_all_trees(s, lcodes, dcodes, blcodes)
2604 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2606 int rank; /* index in bl_order */
2608 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2609 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2611 Tracev((stderr, "\nbl counts: "));
2612 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2613 send_bits(s, dcodes-1, 5);
2614 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2615 for (rank = 0; rank < blcodes; rank++) {
2616 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2617 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2619 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2621 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2622 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2624 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2625 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2628 /* ===========================================================================
2629 * Send a stored block
2631 void _tr_stored_block(s, buf, stored_len, eof)
2633 charf *buf; /* input block */
2634 ulg stored_len; /* length of input block */
2635 int eof; /* true if this is the last block for a file */
2637 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2638 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
2639 s->compressed_len += (stored_len + 4) << 3;
2641 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2644 /* Send just the `stored block' type code without any length bytes or data.
2646 void _tr_stored_type_only(s)
2649 send_bits(s, (STORED_BLOCK << 1), 3);
2651 s->compressed_len = (s->compressed_len + 3) & ~7L;
2655 /* ===========================================================================
2656 * Send one empty static block to give enough lookahead for inflate.
2657 * This takes 10 bits, of which 7 may remain in the bit buffer.
2658 * The current inflate code requires 9 bits of lookahead. If the
2659 * last two codes for the previous block (real code plus EOB) were coded
2660 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
2661 * the last real code. In this case we send two empty static blocks instead
2662 * of one. (There are no problems if the previous block is stored or fixed.)
2663 * To simplify the code, we assume the worst case of last real code encoded
2669 send_bits(s, STATIC_TREES<<1, 3);
2670 send_code(s, END_BLOCK, static_ltree);
2671 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2673 /* Of the 10 bits for the empty block, we have already sent
2674 * (10 - bi_valid) bits. The lookahead for the last real code (before
2675 * the EOB of the previous block) was thus at least one plus the length
2676 * of the EOB plus what we have just sent of the empty static block.
2678 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
2679 send_bits(s, STATIC_TREES<<1, 3);
2680 send_code(s, END_BLOCK, static_ltree);
2681 s->compressed_len += 10L;
2684 s->last_eob_len = 7;
2687 /* ===========================================================================
2688 * Determine the best encoding for the current block: dynamic trees, static
2689 * trees or store, and output the encoded block to the zip file. This function
2690 * returns the total compressed length for the file so far.
2692 ulg _tr_flush_block(s, buf, stored_len, eof)
2694 charf *buf; /* input block, or NULL if too old */
2695 ulg stored_len; /* length of input block */
2696 int eof; /* true if this is the last block for a file */
2698 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2699 int max_blindex = 0; /* index of last bit length code of non zero freq */
2701 /* Build the Huffman trees unless a stored block is forced */
2704 /* Check if the file is ascii or binary */
2705 if (s->data_type == Z_UNKNOWN) set_data_type(s);
2707 /* Construct the literal and distance trees */
2708 build_tree(s, (tree_desc *)(&(s->l_desc)));
2709 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2712 build_tree(s, (tree_desc *)(&(s->d_desc)));
2713 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2715 /* At this point, opt_len and static_len are the total bit lengths of
2716 * the compressed block data, excluding the tree representations.
2719 /* Build the bit length tree for the above two trees, and get the index
2720 * in bl_order of the last bit length code to send.
2722 max_blindex = build_bl_tree(s);
2724 /* Determine the best encoding. Compute first the block length in bytes*/
2725 opt_lenb = (s->opt_len+3+7)>>3;
2726 static_lenb = (s->static_len+3+7)>>3;
2728 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2729 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2732 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2735 Assert(buf != (char*)0, "lost buf");
2736 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
2739 /* If compression failed and this is the first and last block,
2740 * and if the .zip file can be seeked (to rewrite the local header),
2741 * the whole file is transformed into a stored file:
2743 #ifdef STORED_FILE_OK
2744 # ifdef FORCE_STORED_FILE
2745 if (eof && s->compressed_len == 0L) { /* force stored file */
2747 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
2749 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2750 if (buf == (charf*)0) error ("block vanished");
2752 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
2753 s->compressed_len = stored_len << 3;
2756 #endif /* STORED_FILE_OK */
2759 if (buf != (char*)0) { /* force stored block */
2761 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2762 /* 4: two words for the lengths */
2764 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2765 * Otherwise we can't have processed more than WSIZE input bytes since
2766 * the last block flush, because compression would have been
2767 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2768 * transform a block into a stored block.
2770 _tr_stored_block(s, buf, stored_len, eof);
2773 } else if (static_lenb >= 0) { /* force static trees */
2775 } else if (static_lenb == opt_lenb) {
2777 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2778 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2779 s->compressed_len += 3 + s->static_len;
2781 send_bits(s, (DYN_TREES<<1)+eof, 3);
2782 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2784 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2785 s->compressed_len += 3 + s->opt_len;
2787 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2792 s->compressed_len += 7; /* align on byte boundary */
2794 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2795 s->compressed_len-7*eof));
2797 return s->compressed_len >> 3;
2800 /* ===========================================================================
2801 * Save the match info and tally the frequency counts. Return true if
2802 * the current block must be flushed.
2804 int _tr_tally (s, dist, lc)
2806 unsigned dist; /* distance of matched string */
2807 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2809 s->d_buf[s->last_lit] = (ush)dist;
2810 s->l_buf[s->last_lit++] = (uch)lc;
2812 /* lc is the unmatched char */
2813 s->dyn_ltree[lc].Freq++;
2816 /* Here, lc is the match length - MIN_MATCH */
2817 dist--; /* dist = match distance - 1 */
2818 Assert((ush)dist < (ush)MAX_DIST(s) &&
2819 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2820 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
2822 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2823 s->dyn_dtree[d_code(dist)].Freq++;
2826 /* Try to guess if it is profitable to stop the current block here */
2827 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2828 /* Compute an upper bound for the compressed length */
2829 ulg out_length = (ulg)s->last_lit*8L;
2830 ulg in_length = (ulg)((long)s->strstart - s->block_start);
2832 for (dcode = 0; dcode < D_CODES; dcode++) {
2833 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2834 (5L+extra_dbits[dcode]);
2837 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2838 s->last_lit, in_length, out_length,
2839 100L - out_length*100L/in_length));
2840 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2842 return (s->last_lit == s->lit_bufsize-1);
2843 /* We avoid equality with lit_bufsize because of wraparound at 64K
2844 * on 16 bit machines and because stored blocks are restricted to
2849 /* ===========================================================================
2850 * Send the block data compressed using the given Huffman trees
2852 local void compress_block(s, ltree, dtree)
2854 ct_data *ltree; /* literal tree */
2855 ct_data *dtree; /* distance tree */
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).
2905 local void set_data_type(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
2922 local unsigned bi_reverse(code, len)
2923 unsigned code; /* the value to invert */
2924 int len; /* its bit length */
2926 register unsigned res = 0;
2929 code >>= 1, res <<= 1;
2930 } while (--len > 0);
2934 /* ===========================================================================
2935 * Flush the bit buffer, keeping at most 7 bits in it.
2937 local void bi_flush(s)
2940 if (s->bi_valid == 16) {
2941 put_short(s, s->bi_buf);
2944 } else if (s->bi_valid >= 8) {
2945 put_byte(s, (Byte)s->bi_buf);
2951 /* ===========================================================================
2952 * Flush the bit buffer and align the output on a byte boundary
2954 local void bi_windup(s)
2957 if (s->bi_valid > 8) {
2958 put_short(s, s->bi_buf);
2959 } else if (s->bi_valid > 0) {
2960 put_byte(s, (Byte)s->bi_buf);
2965 s->bits_sent = (s->bits_sent+7) & ~7;
2969 /* ===========================================================================
2970 * Copy a stored block, storing first the length and its
2971 * one's complement if requested.
2973 local void copy_block(s, buf, len, header)
2975 charf *buf; /* the input data */
2976 unsigned len; /* its length */
2977 int header; /* true if block header must be written */
2979 bi_windup(s); /* align on byte boundary */
2980 s->last_eob_len = 8; /* enough lookahead for inflate */
2983 put_short(s, (ush)len);
2984 put_short(s, (ush)~len);
2986 s->bits_sent += 2*16;
2990 s->bits_sent += (ulg)len<<3;
2992 /* bundle up the put_byte(s, *buf++) calls */
2993 zmemcpy(&s->pending_buf[s->pending], buf, len);
2999 /* inflate.c -- zlib interface to inflate modules
3000 * Copyright (C) 1995-1996 Mark Adler
3001 * For conditions of distribution and use, see copyright notice in zlib.h
3004 /* #include "zutil.h" */
3006 /* +++ infblock.h */
3007 /* infblock.h -- header to use infblock.c
3008 * Copyright (C) 1995-1996 Mark Adler
3009 * For conditions of distribution and use, see copyright notice in zlib.h
3012 /* WARNING: this file should *not* be used by applications. It is
3013 part of the implementation of the compression library and is
3014 subject to change. Applications should only use zlib.h.
3017 struct inflate_blocks_state;
3018 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3020 extern inflate_blocks_statef * inflate_blocks_new OF((
3022 check_func c, /* check function */
3023 uInt w)); /* window size */
3025 extern int inflate_blocks OF((
3026 inflate_blocks_statef *,
3028 int)); /* initial return code */
3030 extern void inflate_blocks_reset OF((
3031 inflate_blocks_statef *,
3033 uLongf *)); /* check value on output */
3035 extern int inflate_blocks_free OF((
3036 inflate_blocks_statef *,
3038 uLongf *)); /* check value on output */
3040 extern void inflate_set_dictionary OF((
3041 inflate_blocks_statef *s,
3042 const Bytef *d, /* dictionary */
3043 uInt n)); /* dictionary length */
3045 extern int inflate_addhistory OF((
3046 inflate_blocks_statef *,
3049 extern int inflate_packet_flush OF((
3050 inflate_blocks_statef *));
3051 /* --- infblock.h */
3053 #ifndef NO_DUMMY_DECL
3054 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3057 /* inflate private state */
3058 struct internal_state {
3062 METHOD, /* waiting for method byte */
3063 FLAG, /* waiting for flag byte */
3064 DICT4, /* four dictionary check bytes to go */
3065 DICT3, /* three dictionary check bytes to go */
3066 DICT2, /* two dictionary check bytes to go */
3067 DICT1, /* one dictionary check byte to go */
3068 DICT0, /* waiting for inflateSetDictionary */
3069 BLOCKS, /* decompressing blocks */
3070 CHECK4, /* four check bytes to go */
3071 CHECK3, /* three check bytes to go */
3072 CHECK2, /* two check bytes to go */
3073 CHECK1, /* one check byte to go */
3074 DONE, /* finished check, done */
3075 BAD} /* got an error--stay here */
3076 mode; /* current inflate mode */
3078 /* mode dependent information */
3080 uInt method; /* if FLAGS, method byte */
3082 uLong was; /* computed check value */
3083 uLong need; /* stream check value */
3084 } check; /* if CHECK, check values to compare */
3085 uInt marker; /* if BAD, inflateSync's marker bytes count */
3086 } sub; /* submode */
3088 /* mode independent information */
3089 int nowrap; /* flag for no wrapper */
3090 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3091 inflate_blocks_statef
3092 *blocks; /* current inflate_blocks state */
3102 if (z == Z_NULL || z->state == Z_NULL)
3103 return Z_STREAM_ERROR;
3104 z->total_in = z->total_out = 0;
3106 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3107 inflate_blocks_reset(z->state->blocks, z, &c);
3108 Trace((stderr, "inflate: reset\n"));
3118 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3119 return Z_STREAM_ERROR;
3120 if (z->state->blocks != Z_NULL)
3121 inflate_blocks_free(z->state->blocks, z, &c);
3124 Trace((stderr, "inflate: end\n"));
3129 int inflateInit2_(z, w, version, stream_size)
3132 const char *version;
3135 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3136 stream_size != sizeof(z_stream))
3137 return Z_VERSION_ERROR;
3139 /* initialize state */
3141 return Z_STREAM_ERROR;
3144 if (z->zalloc == Z_NULL)
3146 z->zalloc = zcalloc;
3147 z->opaque = (voidpf)0;
3149 if (z->zfree == Z_NULL) z->zfree = zcfree;
3151 if ((z->state = (struct internal_state FAR *)
3152 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3154 z->state->blocks = Z_NULL;
3156 /* handle undocumented nowrap option (no zlib header or check) */
3157 z->state->nowrap = 0;
3161 z->state->nowrap = 1;
3164 /* set window size */
3165 if (w < 8 || w > 15)
3168 return Z_STREAM_ERROR;
3170 z->state->wbits = (uInt)w;
3172 /* create inflate_blocks state */
3173 if ((z->state->blocks =
3174 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3180 Trace((stderr, "inflate: allocated\n"));
3188 int inflateInit_(z, version, stream_size)
3190 const char *version;
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++)
3207 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0)
3208 return Z_STREAM_ERROR;
3210 while (1) switch (z->state->mode)
3214 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3216 z->state->mode = BAD;
3217 z->msg = (char*)"unknown compression method";
3218 z->state->sub.marker = 5; /* can't try inflateSync */
3221 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3223 z->state->mode = BAD;
3224 z->msg = (char*)"invalid window size";
3225 z->state->sub.marker = 5; /* can't try inflateSync */
3228 z->state->mode = FLAG;
3232 if (((z->state->sub.method << 8) + b) % 31)
3234 z->state->mode = BAD;
3235 z->msg = (char*)"incorrect header check";
3236 z->state->sub.marker = 5; /* can't try inflateSync */
3239 Trace((stderr, "inflate: zlib header ok\n"));
3240 if (!(b & PRESET_DICT))
3242 z->state->mode = BLOCKS;
3245 z->state->mode = DICT4;
3248 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3249 z->state->mode = DICT3;
3252 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3253 z->state->mode = DICT2;
3256 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3257 z->state->mode = DICT1;
3260 z->state->sub.check.need += (uLong)NEXTBYTE;
3261 z->adler = z->state->sub.check.need;
3262 z->state->mode = DICT0;
3265 z->state->mode = BAD;
3266 z->msg = (char*)"need dictionary";
3267 z->state->sub.marker = 0; /* can try inflateSync */
3268 return Z_STREAM_ERROR;
3270 r = inflate_blocks(z->state->blocks, z, r);
3271 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3272 r = inflate_packet_flush(z->state->blocks);
3273 if (r == Z_DATA_ERROR)
3275 z->state->mode = BAD;
3276 z->state->sub.marker = 0; /* can try inflateSync */
3279 if (r != Z_STREAM_END)
3282 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3283 if (z->state->nowrap)
3285 z->state->mode = DONE;
3288 z->state->mode = CHECK4;
3291 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3292 z->state->mode = CHECK3;
3295 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3296 z->state->mode = CHECK2;
3299 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3300 z->state->mode = CHECK1;
3303 z->state->sub.check.need += (uLong)NEXTBYTE;
3305 if (z->state->sub.check.was != z->state->sub.check.need)
3307 z->state->mode = BAD;
3308 z->msg = (char*)"incorrect data check";
3309 z->state->sub.marker = 5; /* can't try inflateSync */
3312 Trace((stderr, "inflate: zlib check ok\n"));
3313 z->state->mode = DONE;
3315 return Z_STREAM_END;
3317 return Z_DATA_ERROR;
3319 return Z_STREAM_ERROR;
3323 if (f != Z_PACKET_FLUSH)
3325 z->state->mode = BAD;
3326 z->msg = (char *)"need more for packet flush";
3327 z->state->sub.marker = 0; /* can try inflateSync */
3328 return Z_DATA_ERROR;
3332 int inflateSetDictionary(z, dictionary, dictLength)
3334 const Bytef *dictionary;
3337 uInt length = dictLength;
3339 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3340 return Z_STREAM_ERROR;
3342 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3345 if (length >= ((uInt)1<<z->state->wbits))
3347 length = (1<<z->state->wbits)-1;
3348 dictionary += dictLength - length;
3350 inflate_set_dictionary(z->state->blocks, dictionary, length);
3351 z->state->mode = BLOCKS;
3356 * This subroutine adds the data at next_in/avail_in to the output history
3357 * without performing any output. The output buffer must be "caught up";
3358 * i.e. no pending output (hence s->read equals s->write), and the state must
3359 * be BLOCKS (i.e. we should be willing to see the start of a series of
3360 * BLOCKS). On exit, the output will also be caught up, and the checksum
3361 * will have been updated if need be.
3364 int inflateIncomp(z)
3367 if (z->state->mode != BLOCKS)
3368 return Z_DATA_ERROR;
3369 return inflate_addhistory(z->state->blocks, z);
3376 uInt n; /* number of bytes to look at */
3377 Bytef *p; /* pointer to bytes */
3378 uInt m; /* number of marker bytes found in a row */
3379 uLong r, w; /* temporaries to save total_in and total_out */
3382 if (z == Z_NULL || z->state == Z_NULL)
3383 return Z_STREAM_ERROR;
3384 if (z->state->mode != BAD)
3386 z->state->mode = BAD;
3387 z->state->sub.marker = 0;
3389 if ((n = z->avail_in) == 0)
3392 m = z->state->sub.marker;
3397 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3407 z->total_in += p - z->next_in;
3410 z->state->sub.marker = m;
3412 /* return no joy or set up to restart on a new block */
3414 return Z_DATA_ERROR;
3415 r = z->total_in; w = z->total_out;
3417 z->total_in = r; z->total_out = w;
3418 z->state->mode = BLOCKS;
3426 /* +++ infblock.c */
3427 /* infblock.c -- interpret and process block types to last block
3428 * Copyright (C) 1995-1996 Mark Adler
3429 * For conditions of distribution and use, see copyright notice in zlib.h
3432 /* #include "zutil.h" */
3433 /* #include "infblock.h" */
3435 /* +++ inftrees.h */
3436 /* inftrees.h -- header to use inftrees.c
3437 * Copyright (C) 1995-1996 Mark Adler
3438 * For conditions of distribution and use, see copyright notice in zlib.h
3441 /* WARNING: this file should *not* be used by applications. It is
3442 part of the implementation of the compression library and is
3443 subject to change. Applications should only use zlib.h.
3446 /* Huffman code lookup table entry--this entry is four bytes for machines
3447 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3449 typedef struct inflate_huft_s FAR inflate_huft;
3451 struct inflate_huft_s {
3454 Byte Exop; /* number of extra bits or operation */
3455 Byte Bits; /* number of bits in this code or subcode */
3457 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
3458 } word; /* 16-bit, 8 bytes for 32-bit machines) */
3460 uInt Base; /* literal, length base, or distance base */
3461 inflate_huft *Next; /* pointer to next level of table */
3466 extern uInt inflate_hufts;
3469 extern int inflate_trees_bits OF((
3470 uIntf *, /* 19 code lengths */
3471 uIntf *, /* bits tree desired/actual depth */
3472 inflate_huft * FAR *, /* bits tree result */
3473 z_streamp )); /* for zalloc, zfree functions */
3475 extern int inflate_trees_dynamic OF((
3476 uInt, /* number of literal/length codes */
3477 uInt, /* number of distance codes */
3478 uIntf *, /* that many (total) code lengths */
3479 uIntf *, /* literal desired/actual bit depth */
3480 uIntf *, /* distance desired/actual bit depth */
3481 inflate_huft * FAR *, /* literal/length tree result */
3482 inflate_huft * FAR *, /* distance tree result */
3483 z_streamp )); /* for zalloc, zfree functions */
3485 extern int inflate_trees_fixed OF((
3486 uIntf *, /* literal desired/actual bit depth */
3487 uIntf *, /* distance desired/actual bit depth */
3488 inflate_huft * FAR *, /* literal/length tree result */
3489 inflate_huft * FAR *)); /* distance tree result */
3491 extern int inflate_trees_free OF((
3492 inflate_huft *, /* tables to free */
3493 z_streamp )); /* for zfree function */
3495 /* --- inftrees.h */
3497 /* +++ infcodes.h */
3498 /* infcodes.h -- header to use infcodes.c
3499 * Copyright (C) 1995-1996 Mark Adler
3500 * For conditions of distribution and use, see copyright notice in zlib.h
3503 /* WARNING: this file should *not* be used by applications. It is
3504 part of the implementation of the compression library and is
3505 subject to change. Applications should only use zlib.h.
3508 struct inflate_codes_state;
3509 typedef struct inflate_codes_state FAR inflate_codes_statef;
3511 extern inflate_codes_statef *inflate_codes_new OF((
3513 inflate_huft *, inflate_huft *,
3516 extern int inflate_codes OF((
3517 inflate_blocks_statef *,
3521 extern void inflate_codes_free OF((
3522 inflate_codes_statef *,
3525 /* --- infcodes.h */
3528 /* infutil.h -- types and macros common to blocks and codes
3529 * Copyright (C) 1995-1996 Mark Adler
3530 * For conditions of distribution and use, see copyright notice in zlib.h
3533 /* WARNING: this file should *not* be used by applications. It is
3534 part of the implementation of the compression library and is
3535 subject to change. Applications should only use zlib.h.
3542 TYPE, /* get type bits (3, including end bit) */
3543 LENS, /* get lengths for stored */
3544 STORED, /* processing stored block */
3545 TABLE, /* get table lengths */
3546 BTREE, /* get bit lengths tree for a dynamic block */
3547 DTREE, /* get length, distance trees for a dynamic block */
3548 CODES, /* processing fixed or dynamic block */
3549 DRY, /* output remaining window bytes */
3550 DONEB, /* finished last block, done */
3551 BADB} /* got a data error--stuck here */
3554 /* inflate blocks semi-private state */
3555 struct inflate_blocks_state {
3558 inflate_block_mode mode; /* current inflate_block mode */
3560 /* mode dependent information */
3562 uInt left; /* if STORED, bytes left to copy */
3564 uInt table; /* table lengths (14 bits) */
3565 uInt index; /* index into blens (or border) */
3566 uIntf *blens; /* bit lengths of codes */
3567 uInt bb; /* bit length tree depth */
3568 inflate_huft *tb; /* bit length decoding tree */
3569 } trees; /* if DTREE, decoding info for trees */
3572 inflate_huft *td; /* trees to free */
3573 inflate_codes_statef
3575 } decode; /* if CODES, current state */
3576 } sub; /* submode */
3577 uInt last; /* true if this block is the last block */
3579 /* mode independent information */
3580 uInt bitk; /* bits in bit buffer */
3581 uLong bitb; /* bit buffer */
3582 Bytef *window; /* sliding window */
3583 Bytef *end; /* one byte after sliding window */
3584 Bytef *read; /* window read pointer */
3585 Bytef *write; /* window write pointer */
3586 check_func checkfn; /* check function */
3587 uLong check; /* check on output */
3592 /* defines for inflate input/output */
3593 /* update pointers and return */
3594 #define UPDBITS {s->bitb=b;s->bitk=k;}
3595 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3596 #define UPDOUT {s->write=q;}
3597 #define UPDATE {UPDBITS UPDIN UPDOUT}
3598 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3599 /* get bytes and bits */
3600 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3601 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3602 #define NEXTBYTE (n--,*p++)
3603 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3604 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3606 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3607 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3608 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3609 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3610 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;}
3611 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3612 /* load local pointers */
3613 #define LOAD {LOADIN LOADOUT}
3615 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3616 extern uInt inflate_mask[17];
3618 /* copy as much as possible from the sliding window to the output area */
3619 extern int inflate_flush OF((
3620 inflate_blocks_statef *,
3624 #ifndef NO_DUMMY_DECL
3625 struct internal_state {int dummy;}; /* for buggy compilers */
3631 #ifndef NO_DUMMY_DECL
3632 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3635 /* Table for deflate from PKZIP's appnote.txt. */
3636 local const uInt border[] = { /* Order of the bit length code lengths */
3637 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3640 Notes beyond the 1.93a appnote.txt:
3642 1. Distance pointers never point before the beginning of the output
3644 2. Distance pointers can point back across blocks, up to 32k away.
3645 3. There is an implied maximum of 7 bits for the bit length table and
3646 15 bits for the actual data.
3647 4. If only one code exists, then it is encoded using one bit. (Zero
3648 would be more efficient, but perhaps a little confusing.) If two
3649 codes exist, they are coded using one bit each (0 and 1).
3650 5. There is no way of sending zero distance codes--a dummy must be
3651 sent if there are none. (History: a pre 2.0 version of PKZIP would
3652 store blocks with no distance codes, but this was discovered to be
3653 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3654 zero distance codes, which is sent as one code of zero bits in
3656 6. There are up to 286 literal/length codes. Code 256 represents the
3657 end-of-block. Note however that the static length tree defines
3658 288 codes just to fill out the Huffman codes. Codes 286 and 287
3659 cannot be used though, since there is no length base or extra bits
3660 defined for them. Similarily, there are up to 30 distance codes.
3661 However, static trees define 32 codes (all 5 bits) to fill out the
3662 Huffman codes, but the last two had better not show up in the data.
3663 7. Unzip can check dynamic Huffman blocks for complete code sets.
3664 The exception is that a single code would not be complete (see #4).
3665 8. The five bits following the block type is really the number of
3666 literal codes sent minus 257.
3667 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3668 (1+6+6). Therefore, to output three times the length, you output
3669 three codes (1+1+1), whereas to output four times the same length,
3670 you only need two codes (1+3). Hmm.
3671 10. In the tree reconstruction algorithm, Code = Code + Increment
3672 only if BitLength(i) is not zero. (Pretty obvious.)
3673 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3674 12. Note: length code 284 can represent 227-258, but length code 285
3675 really is 258. The last length deserves its own, short code
3676 since it gets used a lot in very redundant files. The length
3677 258 is special since 258 - 3 (the min match length) is 255.
3678 13. The literal/length and distance code bit lengths are read as a
3679 single stream of lengths. It is possible (and advantageous) for
3680 a repeat code (16, 17, or 18) to go across the boundary between
3681 the two sets of lengths.
3685 void inflate_blocks_reset(s, z, c)
3686 inflate_blocks_statef *s;
3690 if (s->checkfn != Z_NULL)
3692 if (s->mode == BTREE || s->mode == DTREE)
3693 ZFREE(z, s->sub.trees.blens);
3694 if (s->mode == CODES)
3696 inflate_codes_free(s->sub.decode.codes, z);
3697 inflate_trees_free(s->sub.decode.td, z);
3698 inflate_trees_free(s->sub.decode.tl, z);
3703 s->read = s->write = s->window;
3704 if (s->checkfn != Z_NULL)
3705 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
3706 Trace((stderr, "inflate: blocks reset\n"));
3710 inflate_blocks_statef *inflate_blocks_new(z, c, w)
3715 inflate_blocks_statef *s;
3717 if ((s = (inflate_blocks_statef *)ZALLOC
3718 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3720 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3725 s->end = s->window + w;
3728 Trace((stderr, "inflate: blocks allocated\n"));
3729 inflate_blocks_reset(s, z, &s->check);
3735 extern uInt inflate_hufts;
3737 int inflate_blocks(s, z, r)
3738 inflate_blocks_statef *s;
3742 uInt t; /* temporary storage */
3743 uLong b; /* bit buffer */
3744 uInt k; /* bits in bit buffer */
3745 Bytef *p; /* input data pointer */
3746 uInt n; /* bytes available there */
3747 Bytef *q; /* output window write pointer */
3748 uInt m; /* bytes to end of window or read pointer */
3750 /* copy input/output information to locals (UPDATE macro restores) */
3753 /* process input based on current state */
3754 while (1) switch (s->mode)
3762 case 0: /* stored */
3763 Trace((stderr, "inflate: stored block%s\n",
3764 s->last ? " (last)" : ""));
3766 t = k & 7; /* go to byte boundary */
3768 s->mode = LENS; /* get length of stored block */
3771 Trace((stderr, "inflate: fixed codes block%s\n",
3772 s->last ? " (last)" : ""));
3775 inflate_huft *tl, *td;
3777 inflate_trees_fixed(&bl, &bd, &tl, &td);
3778 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3779 if (s->sub.decode.codes == Z_NULL)
3784 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3785 s->sub.decode.td = Z_NULL;
3790 case 2: /* dynamic */
3791 Trace((stderr, "inflate: dynamic codes block%s\n",
3792 s->last ? " (last)" : ""));
3796 case 3: /* illegal */
3799 z->msg = (char*)"invalid block type";
3806 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
3809 z->msg = (char*)"invalid stored block lengths";
3813 s->sub.left = (uInt)b & 0xffff;
3814 b = k = 0; /* dump bits */
3815 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3816 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
3828 if ((s->sub.left -= t) != 0)
3830 Tracev((stderr, "inflate: stored end, %lu total out\n",
3831 z->total_out + (q >= s->read ? q - s->read :
3832 (s->end - s->read) + (q - s->window))));
3833 s->mode = s->last ? DRY : TYPE;
3837 s->sub.trees.table = t = (uInt)b & 0x3fff;
3838 #ifndef PKZIP_BUG_WORKAROUND
3839 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3842 z->msg = (char*)"too many length or distance symbols";
3847 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3850 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3856 s->sub.trees.index = 0;
3857 Tracev((stderr, "inflate: table sizes ok\n"));
3860 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3863 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3866 while (s->sub.trees.index < 19)
3867 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3868 s->sub.trees.bb = 7;
3869 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3870 &s->sub.trees.tb, z);
3874 if (r == Z_DATA_ERROR) {
3875 ZFREE(z, s->sub.trees.blens);
3880 s->sub.trees.index = 0;
3881 Tracev((stderr, "inflate: bits tree ok\n"));
3884 while (t = s->sub.trees.table,
3885 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3890 t = s->sub.trees.bb;
3892 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3893 t = h->word.what.Bits;
3898 s->sub.trees.blens[s->sub.trees.index++] = c;
3900 else /* c == 16..18 */
3902 i = c == 18 ? 7 : c - 14;
3903 j = c == 18 ? 11 : 3;
3906 j += (uInt)b & inflate_mask[i];
3908 i = s->sub.trees.index;
3909 t = s->sub.trees.table;
3910 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3913 inflate_trees_free(s->sub.trees.tb, z);
3914 ZFREE(z, s->sub.trees.blens);
3916 z->msg = (char*)"invalid bit length repeat";
3920 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3922 s->sub.trees.blens[i++] = c;
3924 s->sub.trees.index = i;
3927 inflate_trees_free(s->sub.trees.tb, z);
3928 s->sub.trees.tb = Z_NULL;
3931 inflate_huft *tl, *td;
3932 inflate_codes_statef *c;
3934 bl = 9; /* must be <= 9 for lookahead assumptions */
3935 bd = 6; /* must be <= 9 for lookahead assumptions */
3936 t = s->sub.trees.table;
3940 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3941 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3944 if (t == (uInt)Z_DATA_ERROR) {
3945 ZFREE(z, s->sub.trees.blens);
3951 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n",
3952 inflate_hufts, sizeof(inflate_huft)));
3953 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3955 inflate_trees_free(td, z);
3956 inflate_trees_free(tl, z);
3961 * this ZFREE must occur *BEFORE* we mess with sub.decode, because
3962 * sub.trees is union'd with sub.decode.
3964 ZFREE(z, s->sub.trees.blens);
3965 s->sub.decode.codes = c;
3966 s->sub.decode.tl = tl;
3967 s->sub.decode.td = td;
3972 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3973 return inflate_flush(s, z, r);
3975 inflate_codes_free(s->sub.decode.codes, z);
3976 inflate_trees_free(s->sub.decode.td, z);
3977 inflate_trees_free(s->sub.decode.tl, z);
3979 Tracev((stderr, "inflate: codes end, %lu total out\n",
3980 z->total_out + (q >= s->read ? q - s->read :
3981 (s->end - s->read) + (q - s->window))));
3987 if (k > 7) /* return unused byte, if any */
3989 Assert(k < 16, "inflate_codes grabbed too many bytes")
3992 p--; /* can always return one */
3997 if (s->read != s->write)
4013 int inflate_blocks_free(s, z, c)
4014 inflate_blocks_statef *s;
4018 inflate_blocks_reset(s, z, c);
4019 ZFREE(z, s->window);
4021 Trace((stderr, "inflate: blocks freed\n"));
4026 void inflate_set_dictionary(s, d, n)
4027 inflate_blocks_statef *s;
4031 zmemcpy((charf *)s->window, d, n);
4032 s->read = s->write = s->window + n;
4036 * This subroutine adds the data at next_in/avail_in to the output history
4037 * without performing any output. The output buffer must be "caught up";
4038 * i.e. no pending output (hence s->read equals s->write), and the state must
4039 * be BLOCKS (i.e. we should be willing to see the start of a series of
4040 * BLOCKS). On exit, the output will also be caught up, and the checksum
4041 * will have been updated if need be.
4043 int inflate_addhistory(s, z)
4044 inflate_blocks_statef *s;
4047 uLong b; /* bit buffer */ /* NOT USED HERE */
4048 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
4049 uInt t; /* temporary storage */
4050 Bytef *p; /* input data pointer */
4051 uInt n; /* bytes available there */
4052 Bytef *q; /* output window write pointer */
4053 uInt m; /* bytes to end of window or read pointer */
4055 if (s->read != s->write)
4056 return Z_STREAM_ERROR;
4057 if (s->mode != TYPE)
4058 return Z_DATA_ERROR;
4060 /* we're ready to rock */
4062 /* while there is input ready, copy to output buffer, moving
4063 * pointers as needed.
4066 t = n; /* how many to do */
4067 /* is there room until end of buffer? */
4069 /* update check information */
4070 if (s->checkfn != Z_NULL)
4071 s->check = (*s->checkfn)(s->check, q, t);
4077 s->read = q; /* drag read pointer forward */
4078 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */
4080 s->read = q = s->window;
4090 * At the end of a Deflate-compressed PPP packet, we expect to have seen
4091 * a `stored' block type value but not the (zero) length bytes.
4093 int inflate_packet_flush(s)
4094 inflate_blocks_statef *s;
4096 if (s->mode != LENS)
4097 return Z_DATA_ERROR;
4101 /* --- infblock.c */
4103 /* +++ inftrees.c */
4104 /* inftrees.c -- generate Huffman trees for efficient decoding
4105 * Copyright (C) 1995-1996 Mark Adler
4106 * For conditions of distribution and use, see copyright notice in zlib.h
4109 /* #include "zutil.h" */
4110 /* #include "inftrees.h" */
4112 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler ";
4114 If you use the zlib library in a product, an acknowledgment is welcome
4115 in the documentation of your product. If for some reason you cannot
4116 include such an acknowledgment, I would appreciate that you keep this
4117 copyright string in the executable of your product.
4120 #ifndef NO_DUMMY_DECL
4121 struct internal_state {int dummy;}; /* for buggy compilers */
4124 /* simplify the use of the inflate_huft type with some defines */
4125 #define base more.Base
4126 #define next more.Next
4127 #define exop word.what.Exop
4128 #define bits word.what.Bits
4131 local int huft_build OF((
4132 uIntf *, /* code lengths in bits */
4133 uInt, /* number of codes */
4134 uInt, /* number of "simple" codes */
4135 const uIntf *, /* list of base values for non-simple codes */
4136 const uIntf *, /* list of extra bits for non-simple codes */
4137 inflate_huft * FAR*,/* result: starting table */
4138 uIntf *, /* maximum lookup bits (returns actual) */
4139 z_streamp )); /* for zalloc function */
4141 local voidpf falloc OF((
4142 voidpf, /* opaque pointer (not used) */
4143 uInt, /* number of items */
4144 uInt)); /* size of item */
4146 /* Tables for deflate from PKZIP's appnote.txt. */
4147 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4148 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4149 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4150 /* see note #13 above about 258 */
4151 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4152 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4153 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4154 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4155 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4156 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4157 8193, 12289, 16385, 24577};
4158 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4159 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4160 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4164 Huffman code decoding is performed using a multi-level table lookup.
4165 The fastest way to decode is to simply build a lookup table whose
4166 size is determined by the longest code. However, the time it takes
4167 to build this table can also be a factor if the data being decoded
4168 is not very long. The most common codes are necessarily the
4169 shortest codes, so those codes dominate the decoding time, and hence
4170 the speed. The idea is you can have a shorter table that decodes the
4171 shorter, more probable codes, and then point to subsidiary tables for
4172 the longer codes. The time it costs to decode the longer codes is
4173 then traded against the time it takes to make longer tables.
4175 This results of this trade are in the variables lbits and dbits
4176 below. lbits is the number of bits the first level table for literal/
4177 length codes can decode in one step, and dbits is the same thing for
4178 the distance codes. Subsequent tables are also less than or equal to
4179 those sizes. These values may be adjusted either when all of the
4180 codes are shorter than that, in which case the longest code length in
4181 bits is used, or when the shortest code is *longer* than the requested
4182 table size, in which case the length of the shortest code in bits is
4185 There are two different values for the two tables, since they code a
4186 different number of possibilities each. The literal/length table
4187 codes 286 possible values, or in a flat code, a little over eight
4188 bits. The distance table codes 30 possible values, or a little less
4189 than five bits, flat. The optimum values for speed end up being
4190 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4191 The optimum values may differ though from machine to machine, and
4192 possibly even between compilers. Your mileage may vary.
4196 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4197 #define BMAX 15 /* maximum bit length of any code */
4198 #define N_MAX 288 /* maximum number of codes in any set */
4204 local int huft_build(b, n, s, d, e, t, m, zs)
4205 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
4206 uInt n; /* number of codes (assumed <= N_MAX) */
4207 uInt s; /* number of simple-valued codes (0..s-1) */
4208 const uIntf *d; /* list of base values for non-simple codes */
4209 const uIntf *e; /* list of extra bits for non-simple codes */
4210 inflate_huft * FAR *t; /* result: starting table */
4211 uIntf *m; /* maximum lookup bits, returns actual */
4212 z_streamp zs; /* for zalloc function */
4213 /* Given a list of code lengths and a maximum table size, make a set of
4214 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
4215 if the given code set is incomplete (the tables are still built in this
4216 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of
4217 lengths), or Z_MEM_ERROR if not enough memory. */
4220 uInt a; /* counter for codes of length k */
4221 uInt c[BMAX+1]; /* bit length count table */
4222 uInt f; /* i repeats in table every f entries */
4223 int g; /* maximum code length */
4224 int h; /* table level */
4225 register uInt i; /* counter, current code */
4226 register uInt j; /* counter */
4227 register int k; /* number of bits in current code */
4228 int l; /* bits per table (returned in m) */
4229 register uIntf *p; /* pointer into c[], b[], or v[] */
4230 inflate_huft *q; /* points to current table */
4231 struct inflate_huft_s r; /* table entry for structure assignment */
4232 inflate_huft *u[BMAX]; /* table stack */
4233 uInt v[N_MAX]; /* values in order of bit length */
4234 register int w; /* bits before this table == (l * h) */
4235 uInt x[BMAX+1]; /* bit offsets, then code stack */
4236 uIntf *xp; /* pointer into x */
4237 int y; /* number of dummy codes added */
4238 uInt z; /* number of entries in current table */
4241 /* Generate counts for each bit length */
4243 #define C0 *p++ = 0;
4244 #define C2 C0 C0 C0 C0
4245 #define C4 C2 C2 C2 C2
4246 C4 /* clear c[]--assume BMAX+1 is 16 */
4249 c[*p++]++; /* assume all entries <= BMAX */
4251 if (c[0] == n) /* null input--all zero length codes */
4253 *t = (inflate_huft *)Z_NULL;
4259 /* Find minimum and maximum length, bound *m by those */
4261 for (j = 1; j <= BMAX; j++)
4264 k = j; /* minimum code length */
4267 for (i = BMAX; i; i--)
4270 g = i; /* maximum code length */
4276 /* Adjust last length count to fill out codes, if needed */
4277 for (y = 1 << j; j < i; j++, y <<= 1)
4278 if ((y -= c[j]) < 0)
4279 return Z_DATA_ERROR;
4280 if ((y -= c[i]) < 0)
4281 return Z_DATA_ERROR;
4285 /* Generate starting offsets into the value table for each length */
4287 p = c + 1; xp = x + 2;
4288 while (--i) { /* note that i == g from above */
4289 *xp++ = (j += *p++);
4293 /* Make a table of values in order of bit lengths */
4296 if ((j = *p++) != 0)
4299 n = x[g]; /* set n to length of v */
4302 /* Generate the Huffman codes and for each, make the table entries */
4303 x[0] = i = 0; /* first Huffman code is zero */
4304 p = v; /* grab values in bit order */
4305 h = -1; /* no tables yet--level -1 */
4306 w = -l; /* bits decoded == (l * h) */
4307 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
4308 q = (inflate_huft *)Z_NULL; /* ditto */
4311 /* go through the bit lengths (k already is bits in shortest code) */
4317 /* here i is the Huffman code of length k bits for value *p */
4318 /* make tables up to required level */
4322 w += l; /* previous table always l bits */
4324 /* compute minimum size table less than or equal to l bits */
4326 z = z > (uInt)l ? l : z; /* table size upper limit */
4327 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
4328 { /* too few codes for k-w bit table */
4329 f -= a + 1; /* deduct codes from patterns left */
4332 while (++j < z) /* try smaller tables up to z bits */
4334 if ((f <<= 1) <= *++xp)
4335 break; /* enough codes to use up j bits */
4336 f -= *xp; /* else deduct codes from patterns */
4339 z = 1 << j; /* table entries for j-bit table */
4341 /* allocate and link in new table */
4342 if ((q = (inflate_huft *)ZALLOC
4343 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
4346 inflate_trees_free(u[0], zs);
4347 return Z_MEM_ERROR; /* not enough memory */
4350 inflate_hufts += z + 1;
4352 *t = q + 1; /* link to list for huft_free() */
4353 *(t = &(q->next)) = Z_NULL;
4354 u[h] = ++q; /* table starts after link */
4356 /* connect to last table, if there is one */
4359 x[h] = i; /* save pattern for backing up */
4360 r.bits = (Byte)l; /* bits to dump before this table */
4361 r.exop = (Byte)j; /* bits in this table */
4362 r.next = q; /* pointer to this table */
4363 j = i >> (w - l); /* (get around Turbo C bug) */
4364 u[h-1][j] = r; /* connect to last table */
4368 /* set up table entry in r */
4369 r.bits = (Byte)(k - w);
4371 r.exop = 128 + 64; /* out of values--invalid code */
4374 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
4375 r.base = *p++; /* simple code is just the value */
4379 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4380 r.base = d[*p++ - s];
4383 /* fill code-like entries with r */
4385 for (j = i >> w; j < z; j += f)
4388 /* backwards increment the k-bit code i */
4389 for (j = 1 << (k - 1); i & j; j >>= 1)
4393 /* backup over finished tables */
4394 while ((i & ((1 << w) - 1)) != x[h])
4396 h--; /* don't need to update q */
4403 /* Return Z_BUF_ERROR if we were given an incomplete table */
4404 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4408 int inflate_trees_bits(c, bb, tb, z)
4409 uIntf *c; /* 19 code lengths */
4410 uIntf *bb; /* bits tree desired/actual depth */
4411 inflate_huft * FAR *tb; /* bits tree result */
4412 z_streamp z; /* for zfree function */
4416 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
4417 if (r == Z_DATA_ERROR)
4418 z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4419 else if (r == Z_BUF_ERROR || *bb == 0)
4421 inflate_trees_free(*tb, z);
4422 z->msg = (char*)"incomplete dynamic bit lengths tree";
4429 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
4430 uInt nl; /* number of literal/length codes */
4431 uInt nd; /* number of distance codes */
4432 uIntf *c; /* that many (total) code lengths */
4433 uIntf *bl; /* literal desired/actual bit depth */
4434 uIntf *bd; /* distance desired/actual bit depth */
4435 inflate_huft * FAR *tl; /* literal/length tree result */
4436 inflate_huft * FAR *td; /* distance tree result */
4437 z_streamp z; /* for zfree function */
4441 /* build literal/length tree */
4442 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z);
4443 if (r != Z_OK || *bl == 0)
4445 if (r == Z_DATA_ERROR)
4446 z->msg = (char*)"oversubscribed literal/length tree";
4447 else if (r != Z_MEM_ERROR)
4449 inflate_trees_free(*tl, z);
4450 z->msg = (char*)"incomplete literal/length tree";
4456 /* build distance tree */
4457 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z);
4458 if (r != Z_OK || (*bd == 0 && nl > 257))
4460 if (r == Z_DATA_ERROR)
4461 z->msg = (char*)"oversubscribed distance tree";
4462 else if (r == Z_BUF_ERROR) {
4463 #ifdef PKZIP_BUG_WORKAROUND
4467 inflate_trees_free(*td, z);
4468 z->msg = (char*)"incomplete distance tree";
4471 else if (r != Z_MEM_ERROR)
4473 z->msg = (char*)"empty distance tree with lengths";
4476 inflate_trees_free(*tl, z);
4486 /* build fixed tables only once--keep them here */
4487 local int fixed_built = 0;
4488 #define FIXEDH 530 /* number of hufts used by fixed tables */
4489 local inflate_huft fixed_mem[FIXEDH];
4490 local uInt fixed_bl;
4491 local uInt fixed_bd;
4492 local inflate_huft *fixed_tl;
4493 local inflate_huft *fixed_td;
4496 local voidpf falloc(q, n, s)
4497 voidpf q; /* opaque pointer */
4498 uInt n; /* number of items */
4499 uInt s; /* size of item */
4501 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q,
4502 "inflate_trees falloc overflow");
4503 *(intf *)q -= n+s-s; /* s-s to avoid warning */
4504 return (voidpf)(fixed_mem + *(intf *)q);
4508 int inflate_trees_fixed(bl, bd, tl, td)
4509 uIntf *bl; /* literal desired/actual bit depth */
4510 uIntf *bd; /* distance desired/actual bit depth */
4511 inflate_huft * FAR *tl; /* literal/length tree result */
4512 inflate_huft * FAR *td; /* distance tree result */
4514 /* build fixed tables if not already (multiple overlapped executions ok) */
4517 int k; /* temporary variable */
4518 unsigned c[288]; /* length list for huft_build */
4519 z_stream z; /* for falloc function */
4520 int f = FIXEDH; /* number of hufts left in fixed_mem */
4522 /* set up fake z_stream for memory routines */
4525 z.opaque = (voidpf)&f;
4528 for (k = 0; k < 144; k++)
4530 for (; k < 256; k++)
4532 for (; k < 280; k++)
4534 for (; k < 288; k++)
4537 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4539 /* distance table */
4540 for (k = 0; k < 30; k++)
4543 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4546 Assert(f == 0, "invalid build of fixed tables");
4557 int inflate_trees_free(t, z)
4558 inflate_huft *t; /* table to free */
4559 z_streamp z; /* for zfree function */
4560 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4561 list of the tables it made, with the links in a dummy first entry of
4564 register inflate_huft *p, *q, *r;
4566 /* Reverse linked list */
4576 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4585 /* --- inftrees.c */
4587 /* +++ infcodes.c */
4588 /* infcodes.c -- process literals and length/distance pairs
4589 * Copyright (C) 1995-1996 Mark Adler
4590 * For conditions of distribution and use, see copyright notice in zlib.h
4593 /* #include "zutil.h" */
4594 /* #include "inftrees.h" */
4595 /* #include "infblock.h" */
4596 /* #include "infcodes.h" */
4597 /* #include "infutil.h" */
4600 /* inffast.h -- header to use inffast.c
4601 * Copyright (C) 1995-1996 Mark Adler
4602 * For conditions of distribution and use, see copyright notice in zlib.h
4605 /* WARNING: this file should *not* be used by applications. It is
4606 part of the implementation of the compression library and is
4607 subject to change. Applications should only use zlib.h.
4610 extern int inflate_fast OF((
4615 inflate_blocks_statef *,
4619 /* simplify the use of the inflate_huft type with some defines */
4620 #define base more.Base
4621 #define next more.Next
4622 #define exop word.what.Exop
4623 #define bits word.what.Bits
4625 /* inflate codes private state */
4626 struct inflate_codes_state {
4629 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4630 START, /* x: set up for LEN */
4631 LEN, /* i: get length/literal/eob next */
4632 LENEXT, /* i: getting length extra (have base) */
4633 DIST, /* i: get distance next */
4634 DISTEXT, /* i: getting distance extra */
4635 COPY, /* o: copying bytes in window, waiting for space */
4636 LIT, /* o: got literal, waiting for output space */
4637 WASH, /* o: got eob, possibly still output waiting */
4638 END, /* x: got eob and all data flushed */
4639 BADCODE} /* x: got error */
4640 mode; /* current inflate_codes mode */
4642 /* mode dependent information */
4646 inflate_huft *tree; /* pointer into tree */
4647 uInt need; /* bits needed */
4648 } code; /* if LEN or DIST, where in tree */
4649 uInt lit; /* if LIT, literal */
4651 uInt get; /* bits to get for extra */
4652 uInt dist; /* distance back to copy from */
4653 } copy; /* if EXT or COPY, where and how much */
4654 } sub; /* submode */
4656 /* mode independent information */
4657 Byte lbits; /* ltree bits decoded per branch */
4658 Byte dbits; /* dtree bits decoder per branch */
4659 inflate_huft *ltree; /* literal/length/eob tree */
4660 inflate_huft *dtree; /* distance tree */
4665 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4668 inflate_huft *td; /* need separate declaration for Borland C++ */
4671 inflate_codes_statef *c;
4673 if ((c = (inflate_codes_statef *)
4674 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4677 c->lbits = (Byte)bl;
4678 c->dbits = (Byte)bd;
4681 Tracev((stderr, "inflate: codes new\n"));
4687 int inflate_codes(s, z, r)
4688 inflate_blocks_statef *s;
4692 uInt j; /* temporary storage */
4693 inflate_huft *t; /* temporary pointer */
4694 uInt e; /* extra bits or operation */
4695 uLong b; /* bit buffer */
4696 uInt k; /* bits in bit buffer */
4697 Bytef *p; /* input data pointer */
4698 uInt n; /* bytes available there */
4699 Bytef *q; /* output window write pointer */
4700 uInt m; /* bytes to end of window or read pointer */
4701 Bytef *f; /* pointer to copy strings from */
4702 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4704 /* copy input/output information to locals (UPDATE macro restores) */
4707 /* process input and output based on current state */
4708 while (1) switch (c->mode)
4709 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4710 case START: /* x: set up for LEN */
4712 if (m >= 258 && n >= 10)
4715 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4719 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4724 c->sub.code.need = c->lbits;
4725 c->sub.code.tree = c->ltree;
4727 case LEN: /* i: get length/literal/eob next */
4728 j = c->sub.code.need;
4730 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4732 e = (uInt)(t->exop);
4733 if (e == 0) /* literal */
4735 c->sub.lit = t->base;
4736 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4737 "inflate: literal '%c'\n" :
4738 "inflate: literal 0x%02x\n", t->base));
4742 if (e & 16) /* length */
4744 c->sub.copy.get = e & 15;
4749 if ((e & 64) == 0) /* next table */
4751 c->sub.code.need = e;
4752 c->sub.code.tree = t->next;
4755 if (e & 32) /* end of block */
4757 Tracevv((stderr, "inflate: end of block\n"));
4761 c->mode = BADCODE; /* invalid code */
4762 z->msg = (char*)"invalid literal/length code";
4765 case LENEXT: /* i: getting length extra (have base) */
4766 j = c->sub.copy.get;
4768 c->len += (uInt)b & inflate_mask[j];
4770 c->sub.code.need = c->dbits;
4771 c->sub.code.tree = c->dtree;
4772 Tracevv((stderr, "inflate: length %u\n", c->len));
4774 case DIST: /* i: get distance next */
4775 j = c->sub.code.need;
4777 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4779 e = (uInt)(t->exop);
4780 if (e & 16) /* distance */
4782 c->sub.copy.get = e & 15;
4783 c->sub.copy.dist = t->base;
4787 if ((e & 64) == 0) /* next table */
4789 c->sub.code.need = e;
4790 c->sub.code.tree = t->next;
4793 c->mode = BADCODE; /* invalid code */
4794 z->msg = (char*)"invalid distance code";
4797 case DISTEXT: /* i: getting distance extra */
4798 j = c->sub.copy.get;
4800 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4802 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4804 case COPY: /* o: copying bytes in window, waiting for space */
4805 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4806 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4807 s->end - (c->sub.copy.dist - (q - s->window)) :
4808 q - c->sub.copy.dist;
4810 f = q - c->sub.copy.dist;
4811 if ((uInt)(q - s->window) < c->sub.copy.dist)
4812 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
4824 case LIT: /* o: got literal, waiting for output space */
4829 case WASH: /* o: got eob, possibly more output */
4831 if (s->read != s->write)
4837 case BADCODE: /* x: got error */
4847 void inflate_codes_free(c, z)
4848 inflate_codes_statef *c;
4852 Tracev((stderr, "inflate: codes free\n"));
4854 /* --- infcodes.c */
4857 /* inflate_util.c -- data and routines common to blocks and codes
4858 * Copyright (C) 1995-1996 Mark Adler
4859 * For conditions of distribution and use, see copyright notice in zlib.h
4862 /* #include "zutil.h" */
4863 /* #include "infblock.h" */
4864 /* #include "inftrees.h" */
4865 /* #include "infcodes.h" */
4866 /* #include "infutil.h" */
4868 #ifndef NO_DUMMY_DECL
4869 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4872 /* And'ing with mask[n] masks the lower n bits */
4873 uInt inflate_mask[17] = {
4875 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
4876 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
4880 /* copy as much as possible from the sliding window to the output area */
4881 int inflate_flush(s, z, r)
4882 inflate_blocks_statef *s;
4890 /* local copies of source and destination pointers */
4894 /* compute number of bytes to copy as far as end of window */
4895 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4896 if (n > z->avail_out) n = z->avail_out;
4897 if (n && r == Z_BUF_ERROR) r = Z_OK;
4899 /* update counters */
4903 /* update check information */
4904 if (s->checkfn != Z_NULL)
4905 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4907 /* copy as far as end of window */
4914 /* see if more to copy at beginning of window */
4919 if (s->write == s->end)
4920 s->write = s->window;
4922 /* compute bytes to copy */
4923 n = (uInt)(s->write - q);
4924 if (n > z->avail_out) n = z->avail_out;
4925 if (n && r == Z_BUF_ERROR) r = Z_OK;
4927 /* update counters */
4931 /* update check information */
4932 if (s->checkfn != Z_NULL)
4933 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4943 /* update pointers */
4953 /* inffast.c -- process literals and length/distance pairs fast
4954 * Copyright (C) 1995-1996 Mark Adler
4955 * For conditions of distribution and use, see copyright notice in zlib.h
4958 /* #include "zutil.h" */
4959 /* #include "inftrees.h" */
4960 /* #include "infblock.h" */
4961 /* #include "infcodes.h" */
4962 /* #include "infutil.h" */
4963 /* #include "inffast.h" */
4965 #ifndef NO_DUMMY_DECL
4966 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4969 /* simplify the use of the inflate_huft type with some defines */
4970 #define base more.Base
4971 #define next more.Next
4972 #define exop word.what.Exop
4973 #define bits word.what.Bits
4975 /* macros for bit input with no checking and for returning unused bytes */
4976 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4977 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4979 /* Called with number of bytes left to write in window at least 258
4980 (the maximum string length) and number of input bytes available
4981 at least ten. The ten bytes are six bytes for the longest length/
4982 distance pair plus four bytes for overloading the bit buffer. */
4984 int inflate_fast(bl, bd, tl, td, s, z)
4987 inflate_huft *td; /* need separate declaration for Borland C++ */
4988 inflate_blocks_statef *s;
4991 inflate_huft *t; /* temporary pointer */
4992 uInt e; /* extra bits or operation */
4993 uLong b; /* bit buffer */
4994 uInt k; /* bits in bit buffer */
4995 Bytef *p; /* input data pointer */
4996 uInt n; /* bytes available there */
4997 Bytef *q; /* output window write pointer */
4998 uInt m; /* bytes to end of window or read pointer */
4999 uInt ml; /* mask for literal/length tree */
5000 uInt md; /* mask for distance tree */
5001 uInt c; /* bytes to copy */
5002 uInt d; /* distance back to copy from */
5003 Bytef *r; /* copy source pointer */
5005 /* load input, output, bit values */
5008 /* initialize masks */
5009 ml = inflate_mask[bl];
5010 md = inflate_mask[bd];
5012 /* do until not enough input or output space for fast loop */
5013 do { /* assume called with m >= 258 && n >= 10 */
5014 /* get literal/length code */
5015 GRABBITS(20) /* max bits for literal/length code */
5016 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5019 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5020 "inflate: * literal '%c'\n" :
5021 "inflate: * literal 0x%02x\n", t->base));
5022 *q++ = (Byte)t->base;
5030 /* get extra bits for length */
5032 c = t->base + ((uInt)b & inflate_mask[e]);
5034 Tracevv((stderr, "inflate: * length %u\n", c));
5036 /* decode distance base of block to copy */
5037 GRABBITS(15); /* max bits for distance code */
5038 e = (t = td + ((uInt)b & md))->exop;
5043 /* get extra bits to add to distance base */
5045 GRABBITS(e) /* get extra bits (up to 13) */
5046 d = t->base + ((uInt)b & inflate_mask[e]);
5048 Tracevv((stderr, "inflate: * distance %u\n", d));
5052 if ((uInt)(q - s->window) >= d) /* offset before dest */
5055 *q++ = *r++; c--; /* minimum count is three, */
5056 *q++ = *r++; c--; /* so unroll loop a little */
5058 else /* else offset after destination */
5060 e = d - (uInt)(q - s->window); /* bytes from offset to end */
5061 r = s->end - e; /* pointer to offset */
5062 if (c > e) /* if source crosses, */
5064 c -= e; /* copy to end of window */
5068 r = s->window; /* copy rest from start of window */
5071 do { /* copy all or what's left */
5076 else if ((e & 64) == 0)
5077 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
5080 z->msg = (char*)"invalid distance code";
5083 return Z_DATA_ERROR;
5090 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
5093 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5094 "inflate: * literal '%c'\n" :
5095 "inflate: * literal 0x%02x\n", t->base));
5096 *q++ = (Byte)t->base;
5103 Tracevv((stderr, "inflate: * end of block\n"));
5106 return Z_STREAM_END;
5110 z->msg = (char*)"invalid literal/length code";
5113 return Z_DATA_ERROR;
5116 } while (m >= 258 && n >= 10);
5118 /* not enough input or output--restore pointers and return */
5126 /* zutil.c -- target dependent utility functions for the compression library
5127 * Copyright (C) 1995-1996 Jean-loup Gailly.
5128 * For conditions of distribution and use, see copyright notice in zlib.h
5131 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */
5137 /* #include "zutil.h" */
5139 #ifndef NO_DUMMY_DECL
5140 struct internal_state {int dummy;}; /* for buggy compilers */
5144 extern void exit OF((int));
5147 static const char *z_errmsg[10] = {
5148 "need dictionary", /* Z_NEED_DICT 2 */
5149 "stream end", /* Z_STREAM_END 1 */
5151 "file error", /* Z_ERRNO (-1) */
5152 "stream error", /* Z_STREAM_ERROR (-2) */
5153 "data error", /* Z_DATA_ERROR (-3) */
5154 "insufficient memory", /* Z_MEM_ERROR (-4) */
5155 "buffer error", /* Z_BUF_ERROR (-5) */
5156 "incompatible version",/* Z_VERSION_ERROR (-6) */
5160 const char *zlibVersion()
5162 return ZLIB_VERSION;
5169 fprintf(stderr, "%s\n", m);
5176 void zmemcpy(dest, source, len)
5181 if (len == 0) return;
5183 *dest++ = *source++; /* ??? to be unrolled */
5184 } while (--len != 0);
5187 int zmemcmp(s1, s2, len)
5194 for (j = 0; j < len; j++) {
5195 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5200 void zmemzero(dest, len)
5204 if (len == 0) return;
5206 *dest++ = 0; /* ??? to be unrolled */
5207 } while (--len != 0);
5212 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5213 /* Small and medium model in Turbo C are for now limited to near allocation
5214 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5218 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5219 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5220 * must fix the pointer. Warning: the pointer must be put back to its
5221 * original form in order to free it, use zcfree().
5227 local int next_ptr = 0;
5229 typedef struct ptr_table_s {
5234 local ptr_table table[MAX_PTR];
5235 /* This table is used to remember the original form of pointers
5236 * to large buffers (64K). Such pointers are normalized with a zero offset.
5237 * Since MSDOS is not a preemptive multitasking OS, this table is not
5238 * protected from concurrent access. This hack doesn't work anyway on
5239 * a protected system like OS/2. Use Microsoft C instead.
5242 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5244 voidpf buf = opaque; /* just to make some compilers happy */
5245 ulg bsize = (ulg)items*size;
5247 /* If we allocate less than 65520 bytes, we assume that farmalloc
5248 * will return a usable pointer which doesn't have to be normalized.
5250 if (bsize < 65520L) {
5251 buf = farmalloc(bsize);
5252 if (*(ush*)&buf != 0) return buf;
5254 buf = farmalloc(bsize + 16L);
5256 if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5257 table[next_ptr].org_ptr = buf;
5259 /* Normalize the pointer to seg:0 */
5260 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5262 table[next_ptr++].new_ptr = buf;
5266 void zcfree (voidpf opaque, voidpf ptr)
5269 if (*(ush*)&ptr != 0) { /* object < 64K */
5273 /* Find the original pointer */
5274 for (n = 0; n < next_ptr; n++) {
5275 if (ptr != table[n].new_ptr) continue;
5277 farfree(table[n].org_ptr);
5278 while (++n < next_ptr) {
5279 table[n-1] = table[n];
5284 ptr = opaque; /* just to make some compilers happy */
5285 Assert(0, "zcfree: ptr not found");
5288 #endif /* __TURBOC__ */
5291 #if defined(M_I86) && !defined(__32BIT__)
5292 /* Microsoft C in 16-bit mode */
5296 #if (!defined(_MSC_VER) || (_MSC_VER < 600))
5297 # define _halloc halloc
5298 # define _hfree hfree
5301 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5303 if (opaque) opaque = 0; /* to make compiler happy */
5304 return _halloc((long)items, size);
5307 void zcfree (voidpf opaque, voidpf ptr)
5309 if (opaque) opaque = 0; /* to make compiler happy */
5316 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5319 extern voidp calloc OF((uInt items, uInt size));
5320 extern void free OF((voidpf ptr));
5323 voidpf zcalloc (opaque, items, size)
5328 if (opaque) items += size - size; /* make compiler happy */
5329 return (voidpf)calloc(items, size);
5332 void zcfree (opaque, ptr)
5337 if (opaque) return; /* make compiler happy */
5340 #endif /* MY_ZCALLOC */
5344 /* adler32.c -- compute the Adler-32 checksum of a data stream
5345 * Copyright (C) 1995-1996 Mark Adler
5346 * For conditions of distribution and use, see copyright notice in zlib.h
5349 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */
5351 /* #include "zlib.h" */
5353 #define BASE 65521L /* largest prime smaller than 65536 */
5355 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5357 #define DO1(buf,i) {s1 += buf[(i)]; s2 += s1;}
5358 #define DO2(buf,i) DO1(buf,i); DO1(buf,(i)+1);
5359 #define DO4(buf,i) DO2(buf,i); DO2(buf,(i)+2);
5360 #define DO8(buf,i) DO4(buf,i); DO4(buf,(i)+4);
5361 #define DO16(buf) DO8(buf,0); DO8(buf,8);
5363 /* ========================================================================= */
5364 uLong adler32(adler, buf, len)
5369 unsigned long s1 = adler & 0xffff;
5370 unsigned long s2 = (adler >> 16) & 0xffff;
5373 if (buf == Z_NULL) return 1L;
5376 k = len < NMAX ? len : NMAX;
5390 return (s2 << 16) | s1;
5396 zlib_modevent(module_t mod, int type, void *unused)
5407 static moduledata_t zlib_mod = {
5412 DECLARE_MODULE(zlib, zlib_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
5413 MODULE_VERSION(zlib, 1);
5414 #endif /* _KERNEL */