2 * This file is derived from various .h and .c files from the zlib-0.95
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 * - changed functions not used outside this file to "local"
10 * - added minCompression parameter to deflateInit2
11 * - added Z_PACKET_FLUSH (see zlib.h for details)
12 * - added inflateIncomp
14 * $Id: zlib.c,v 1.5 1997/03/04 03:26:35 paulus Exp $
18 * ==FILEVERSION 960926==
20 * This marker is used by the Linux installation script to determine
21 * whether an up-to-date version of this file is already installed.
25 /* zutil.h -- internal interface and configuration of the compression library
26 * Copyright (C) 1995 Jean-loup Gailly.
27 * For conditions of distribution and use, see copyright notice in zlib.h
30 /* WARNING: this file should *not* be used by applications. It is
31 part of the implementation of the compression library and is
32 subject to change. Applications should only use zlib.h.
35 /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */
44 /* compile with -Dlocal if your debugger can't find static symbols */
48 typedef unsigned char uch;
50 typedef unsigned short ush;
52 typedef unsigned long ulg;
54 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
56 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
57 /* To be used only when the state is known to be valid */
60 #define NULL ((void *) 0)
63 /* common constants */
68 # define DEF_WBITS MAX_WBITS
70 /* default windowBits for decompression. MAX_WBITS is for compression only */
72 #if MAX_MEM_LEVEL >= 8
73 # define DEF_MEM_LEVEL 8
75 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
77 /* default memLevel */
79 #define STORED_BLOCK 0
80 #define STATIC_TREES 1
82 /* The three kinds of block type */
86 /* The minimum and maximum match lengths */
90 #if defined(KERNEL) || defined(_KERNEL)
91 #include <sys/types.h>
93 #include <sys/systm.h>
94 # define zmemcpy(d, s, n) bcopy((s), (d), (n))
95 # define zmemzero bzero
98 #if defined(__KERNEL__)
99 /* Assume this is Linux */
100 #include <linux/string.h>
101 #define zmemcpy memcpy
102 #define zmemzero(dest, len) memset(dest, 0, len)
104 #else /* not kernel */
105 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
109 # define zmemcpy memcpy
110 # define zmemzero(dest, len) memset(dest, 0, len)
112 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
113 extern void zmemzero OF((Bytef* dest, uInt len));
115 #endif /* __KERNEL__ */
118 /* Diagnostic functions */
124 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
125 # define Trace(x) fprintf x
126 # define Tracev(x) {if (verbose) fprintf x ;}
127 # define Tracevv(x) {if (verbose>1) fprintf x ;}
128 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
129 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
131 # define Assert(cond,msg)
136 # define Tracecv(c,x)
140 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
142 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
143 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
145 #define ZALLOC(strm, items, size) \
146 (*((strm)->zalloc))((strm)->opaque, (items), (size))
147 #define ZFREE(strm, addr, size) \
148 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
149 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
151 /* deflate.h -- internal compression state
152 * Copyright (C) 1995 Jean-loup Gailly
153 * For conditions of distribution and use, see copyright notice in zlib.h
156 /* WARNING: this file should *not* be used by applications. It is
157 part of the implementation of the compression library and is
158 subject to change. Applications should only use zlib.h.
163 /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */
165 /* ===========================================================================
166 * Internal compression state.
174 #define LENGTH_CODES 29
175 /* number of length codes, not counting the special END_BLOCK code */
178 /* number of literal bytes 0..255 */
180 #define L_CODES (LITERALS+1+LENGTH_CODES)
181 /* number of Literal or Length codes, including the END_BLOCK code */
184 /* number of distance codes */
187 /* number of codes used to transfer the bit lengths */
189 #define HEAP_SIZE (2*L_CODES+1)
190 /* maximum heap size */
193 /* All codes must not exceed MAX_BITS bits */
195 #define INIT_STATE 42
196 #define BUSY_STATE 113
197 #define FLUSH_STATE 124
198 #define FINISH_STATE 666
202 /* Data structure describing a single value and its code string. */
203 typedef struct ct_data_s {
205 ush freq; /* frequency count */
206 ush code; /* bit string */
209 ush dad; /* father node in Huffman tree */
210 ush len; /* length of bit string */
219 typedef struct static_tree_desc_s static_tree_desc;
221 typedef struct tree_desc_s {
222 ct_data *dyn_tree; /* the dynamic tree */
223 int max_code; /* largest code with non zero frequency */
224 static_tree_desc *stat_desc; /* the corresponding static tree */
228 typedef Pos FAR Posf;
229 typedef unsigned IPos;
231 /* A Pos is an index in the character window. We use short instead of int to
232 * save space in the various tables. IPos is used only for parameter passing.
235 typedef struct deflate_state {
236 z_stream *strm; /* pointer back to this zlib stream */
237 int status; /* as the name implies */
238 Bytef *pending_buf; /* output still pending */
239 Bytef *pending_out; /* next pending byte to output to the stream */
240 int pending; /* nb of bytes in the pending buffer */
241 uLong adler; /* adler32 of uncompressed data */
242 int noheader; /* suppress zlib header and adler32 */
243 Byte data_type; /* UNKNOWN, BINARY or ASCII */
244 Byte method; /* STORED (for zip only) or DEFLATED */
245 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */
247 /* used by deflate.c: */
249 uInt w_size; /* LZ77 window size (32K by default) */
250 uInt w_bits; /* log2(w_size) (8..16) */
251 uInt w_mask; /* w_size - 1 */
254 /* Sliding window. Input bytes are read into the second half of the window,
255 * and move to the first half later to keep a dictionary of at least wSize
256 * bytes. With this organization, matches are limited to a distance of
257 * wSize-MAX_MATCH bytes, but this ensures that IO is always
258 * performed with a length multiple of the block size. Also, it limits
259 * the window size to 64K, which is quite useful on MSDOS.
260 * To do: use the user input buffer as sliding window.
264 /* Actual size of window: 2*wSize, except when the user input buffer
265 * is directly used as sliding window.
269 /* Link to older string with same hash index. To limit the size of this
270 * array to 64K, this link is maintained only for the last 32K strings.
271 * An index in this array is thus a window index modulo 32K.
274 Posf *head; /* Heads of the hash chains or NIL. */
276 uInt ins_h; /* hash index of string to be inserted */
277 uInt hash_size; /* number of elements in hash table */
278 uInt hash_bits; /* log2(hash_size) */
279 uInt hash_mask; /* hash_size-1 */
282 /* Number of bits by which ins_h must be shifted at each input
283 * step. It must be such that after MIN_MATCH steps, the oldest
284 * byte no longer takes part in the hash key, that is:
285 * hash_shift * MIN_MATCH >= hash_bits
289 /* Window position at the beginning of the current output block. Gets
290 * negative when the window is moved backwards.
293 uInt match_length; /* length of best match */
294 IPos prev_match; /* previous match */
295 int match_available; /* set if previous match exists */
296 uInt strstart; /* start of string to insert */
297 uInt match_start; /* start of matching string */
298 uInt lookahead; /* number of valid bytes ahead in window */
301 /* Length of the best match at previous step. Matches not greater than this
302 * are discarded. This is used in the lazy match evaluation.
305 uInt max_chain_length;
306 /* To speed up deflation, hash chains are never searched beyond this
307 * length. A higher limit improves compression ratio but degrades the
312 /* Attempt to find a better match only when the current match is strictly
313 * smaller than this value. This mechanism is used only for compression
316 # define max_insert_length max_lazy_match
317 /* Insert new strings in the hash table only if the match length is not
318 * greater than this length. This saves time but degrades compression.
319 * max_insert_length is used only for compression levels <= 3.
322 int level; /* compression level (1..9) */
323 int strategy; /* favor or force Huffman coding*/
326 /* Use a faster search when the previous match is longer than this */
328 int nice_match; /* Stop searching when current match exceeds this */
330 /* used by trees.c: */
331 /* Didn't use ct_data typedef below to supress compiler warning */
332 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
333 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
334 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
336 struct tree_desc_s l_desc; /* desc. for literal tree */
337 struct tree_desc_s d_desc; /* desc. for distance tree */
338 struct tree_desc_s bl_desc; /* desc. for bit length tree */
340 ush bl_count[MAX_BITS+1];
341 /* number of codes at each bit length for an optimal tree */
343 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
344 int heap_len; /* number of elements in the heap */
345 int heap_max; /* element of largest frequency */
346 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
347 * The same heap array is used to build all trees.
350 uch depth[2*L_CODES+1];
351 /* Depth of each subtree used as tie breaker for trees of equal frequency
354 uchf *l_buf; /* buffer for literals or lengths */
357 /* Size of match buffer for literals/lengths. There are 4 reasons for
358 * limiting lit_bufsize to 64K:
359 * - frequencies can be kept in 16 bit counters
360 * - if compression is not successful for the first block, all input
361 * data is still in the window so we can still emit a stored block even
362 * when input comes from standard input. (This can also be done for
363 * all blocks if lit_bufsize is not greater than 32K.)
364 * - if compression is not successful for a file smaller than 64K, we can
365 * even emit a stored file instead of a stored block (saving 5 bytes).
366 * This is applicable only for zip (not gzip or zlib).
367 * - creating new Huffman trees less frequently may not provide fast
368 * adaptation to changes in the input data statistics. (Take for
369 * example a binary file with poorly compressible code followed by
370 * a highly compressible string table.) Smaller buffer sizes give
371 * fast adaptation but have of course the overhead of transmitting
372 * trees more frequently.
373 * - I can't count above 4
376 uInt last_lit; /* running index in l_buf */
379 /* Buffer for distances. To simplify the code, d_buf and l_buf have
380 * the same number of elements. To use different lengths, an extra flag
381 * array would be necessary.
384 ulg opt_len; /* bit length of current block with optimal trees */
385 ulg static_len; /* bit length of current block with static trees */
386 ulg compressed_len; /* total bit length of compressed file */
387 uInt matches; /* number of string matches in current block */
388 int last_eob_len; /* bit length of EOB code for last block */
391 ulg bits_sent; /* bit length of the compressed data */
395 /* Output buffer. bits are inserted starting at the bottom (least
399 /* Number of valid bits in bi_buf. All bits above the last valid bit
403 uInt blocks_in_packet;
404 /* Number of blocks produced since the last time Z_PACKET_FLUSH
410 /* Output a byte on the stream.
411 * IN assertion: there is enough room in pending_buf.
413 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
416 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
417 /* Minimum amount of lookahead, except at the end of the input file.
418 * See deflate.c for comments about the MIN_MATCH+1.
421 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
422 /* In order to simplify the code, particularly on 16 bit machines, match
423 * distances are limited to MAX_DIST instead of WSIZE.
427 local void ct_init OF((deflate_state *s));
428 local int ct_tally OF((deflate_state *s, int dist, int lc));
429 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
431 local void ct_align OF((deflate_state *s));
432 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
434 local void ct_stored_type_only OF((deflate_state *s));
438 /* deflate.c -- compress data using the deflation algorithm
439 * Copyright (C) 1995 Jean-loup Gailly.
440 * For conditions of distribution and use, see copyright notice in zlib.h
446 * The "deflation" process depends on being able to identify portions
447 * of the input text which are identical to earlier input (within a
448 * sliding window trailing behind the input currently being processed).
450 * The most straightforward technique turns out to be the fastest for
451 * most input files: try all possible matches and select the longest.
452 * The key feature of this algorithm is that insertions into the string
453 * dictionary are very simple and thus fast, and deletions are avoided
454 * completely. Insertions are performed at each input character, whereas
455 * string matches are performed only when the previous match ends. So it
456 * is preferable to spend more time in matches to allow very fast string
457 * insertions and avoid deletions. The matching algorithm for small
458 * strings is inspired from that of Rabin & Karp. A brute force approach
459 * is used to find longer strings when a small match has been found.
460 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
461 * (by Leonid Broukhis).
462 * A previous version of this file used a more sophisticated algorithm
463 * (by Fiala and Greene) which is guaranteed to run in linear amortized
464 * time, but has a larger average cost, uses more memory and is patented.
465 * However the F&G algorithm may be faster for some highly redundant
466 * files if the parameter max_chain_length (described below) is too large.
470 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
471 * I found it in 'freeze' written by Leonid Broukhis.
472 * Thanks to many people for bug reports and testing.
476 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
477 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
479 * A description of the Rabin and Karp algorithm is given in the book
480 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
482 * Fiala,E.R., and Greene,D.H.
483 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
487 /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */
489 local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
491 If you use the zlib library in a product, an acknowledgment is welcome
492 in the documentation of your product. If for some reason you cannot
493 include such an acknowledgment, I would appreciate that you keep this
494 copyright string in the executable of your product.
498 /* Tail of hash chains */
501 # define TOO_FAR 4096
503 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
505 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
506 /* Minimum amount of lookahead, except at the end of the input file.
507 * See deflate.c for comments about the MIN_MATCH+1.
510 /* Values for max_lazy_match, good_match and max_chain_length, depending on
511 * the desired pack level (0..9). The values given below have been tuned to
512 * exclude worst case performance for pathological files. Better values may be
513 * found for specific files.
516 typedef struct config_s {
517 ush good_length; /* reduce lazy search above this match length */
518 ush max_lazy; /* do not perform lazy search above this match length */
519 ush nice_length; /* quit search above this match length */
523 local config configuration_table[10] = {
524 /* good lazy nice chain */
525 /* 0 */ {0, 0, 0, 0}, /* store only */
526 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
527 /* 2 */ {4, 5, 16, 8},
528 /* 3 */ {4, 6, 32, 32},
530 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
531 /* 5 */ {8, 16, 32, 32},
532 /* 6 */ {8, 16, 128, 128},
533 /* 7 */ {8, 32, 128, 256},
534 /* 8 */ {32, 128, 258, 1024},
535 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
537 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
538 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
543 /* result of memcmp for equal strings */
545 /* ===========================================================================
546 * Prototypes for local functions.
549 local void fill_window OF((deflate_state *s));
550 local int deflate_fast OF((deflate_state *s, int flush));
551 local int deflate_slow OF((deflate_state *s, int flush));
552 local void lm_init OF((deflate_state *s));
553 local int longest_match OF((deflate_state *s, IPos cur_match));
554 local void putShortMSB OF((deflate_state *s, uInt b));
555 local void flush_pending OF((z_stream *strm));
556 local int read_buf OF((z_stream *strm, charf *buf, unsigned size));
558 void match_init OF((void)); /* asm code initialization */
562 local void check_match OF((deflate_state *s, IPos start, IPos match,
567 /* ===========================================================================
568 * Update a hash value with the given input byte
569 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
570 * input characters, so that a running hash key can be computed from the
571 * previous key instead of complete recalculation each time.
573 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
576 /* ===========================================================================
577 * Insert string str in the dictionary and set match_head to the previous head
578 * of the hash chain (the most recent string with same hash key). Return
579 * the previous length of the hash chain.
580 * IN assertion: all calls to to INSERT_STRING are made with consecutive
581 * input characters and the first MIN_MATCH bytes of str are valid
582 * (except for the last MIN_MATCH-1 bytes of the input file).
584 #define INSERT_STRING(s, str, match_head) \
585 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
586 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
587 s->head[s->ins_h] = (str))
589 /* ===========================================================================
590 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
591 * prev[] will be initialized on the fly.
593 #define CLEAR_HASH(s) \
594 s->head[s->hash_size-1] = NIL; \
595 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
597 /* ========================================================================= */
598 int deflateInit (strm, level)
602 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
604 /* To do: ignore strm->next_in if we use it as window */
607 /* ========================================================================= */
608 int deflateInit2 (strm, level, method, windowBits, memLevel,
609 strategy, minCompression)
621 if (strm == Z_NULL) return Z_STREAM_ERROR;
624 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
625 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
627 if (level == Z_DEFAULT_COMPRESSION) level = 6;
629 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
631 windowBits = -windowBits;
633 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
634 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
635 return Z_STREAM_ERROR;
637 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
638 if (s == Z_NULL) return Z_MEM_ERROR;
639 strm->state = (struct internal_state FAR *)s;
642 s->noheader = noheader;
643 s->w_bits = windowBits;
644 s->w_size = 1 << s->w_bits;
645 s->w_mask = s->w_size - 1;
647 s->hash_bits = memLevel + 7;
648 s->hash_size = 1 << s->hash_bits;
649 s->hash_mask = s->hash_size - 1;
650 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
652 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
653 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
654 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
656 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
658 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
660 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
661 s->pending_buf == Z_NULL) {
662 strm->msg = z_errmsg[1-Z_MEM_ERROR];
666 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
667 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
668 /* We overlay pending_buf and d_buf+l_buf. This works since the average
669 * output size for (length,distance) codes is <= 32 bits (worst case
674 s->strategy = strategy;
675 s->method = (Byte)method;
676 s->minCompr = minCompression;
677 s->blocks_in_packet = 0;
679 return deflateReset(strm);
682 /* ========================================================================= */
683 int deflateReset (strm)
688 if (strm == Z_NULL || strm->state == Z_NULL ||
689 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
691 strm->total_in = strm->total_out = 0;
692 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
693 strm->data_type = Z_UNKNOWN;
695 s = (deflate_state *)strm->state;
697 s->pending_out = s->pending_buf;
699 if (s->noheader < 0) {
700 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
702 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
711 /* =========================================================================
712 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
713 * IN assertion: the stream state is correct and there is enough room in
716 local void putShortMSB (s, b)
720 put_byte(s, (Byte)(b >> 8));
721 put_byte(s, (Byte)(b & 0xff));
724 /* =========================================================================
725 * Flush as much pending output as possible.
727 local void flush_pending(strm)
730 deflate_state *state = (deflate_state *) strm->state;
731 unsigned len = state->pending;
733 if (len > strm->avail_out) len = strm->avail_out;
734 if (len == 0) return;
736 if (strm->next_out != NULL) {
737 zmemcpy(strm->next_out, state->pending_out, len);
738 strm->next_out += len;
740 state->pending_out += len;
741 strm->total_out += len;
742 strm->avail_out -= len;
743 state->pending -= len;
744 if (state->pending == 0) {
745 state->pending_out = state->pending_buf;
749 /* ========================================================================= */
750 int deflate (strm, flush)
754 deflate_state *state = (deflate_state *) strm->state;
756 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
758 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
759 ERR_RETURN(strm, Z_STREAM_ERROR);
761 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
763 state->strm = strm; /* just in case */
765 /* Write the zlib header */
766 if (state->status == INIT_STATE) {
768 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
769 uInt level_flags = (state->level-1) >> 1;
771 if (level_flags > 3) level_flags = 3;
772 header |= (level_flags << 6);
773 header += 31 - (header % 31);
775 state->status = BUSY_STATE;
776 putShortMSB(state, header);
779 /* Flush as much pending output as possible */
780 if (state->pending != 0) {
782 if (strm->avail_out == 0) return Z_OK;
785 /* If we came back in here to get the last output from
786 * a previous flush, we're done for now.
788 if (state->status == FLUSH_STATE) {
789 state->status = BUSY_STATE;
790 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
794 /* User must not provide more input after the first FINISH: */
795 if (state->status == FINISH_STATE && strm->avail_in != 0) {
796 ERR_RETURN(strm, Z_BUF_ERROR);
799 /* Start a new block or continue the current one.
801 if (strm->avail_in != 0 || state->lookahead != 0 ||
802 (flush == Z_FINISH && state->status != FINISH_STATE)) {
805 if (flush == Z_FINISH) {
806 state->status = FINISH_STATE;
808 if (state->level <= 3) {
809 quit = deflate_fast(state, flush);
811 quit = deflate_slow(state, flush);
813 if (quit || strm->avail_out == 0)
815 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
816 * of deflate should use the same flush parameter to make sure
817 * that the flush is complete. So we don't have to output an
818 * empty block here, this will be done at next call. This also
819 * ensures that for a very small output buffer, we emit at most
824 /* If a flush was requested, we have a little more to output now. */
825 if (flush != Z_NO_FLUSH && flush != Z_FINISH
826 && state->status != FINISH_STATE) {
828 case Z_PARTIAL_FLUSH:
832 /* Output just the 3-bit `stored' block type value,
833 but not a zero length. */
834 ct_stored_type_only(state);
837 ct_stored_block(state, (char*)0, 0L, 0);
838 /* For a full flush, this empty block will be recognized
839 * as a special marker by inflate_sync().
841 if (flush == Z_FULL_FLUSH) {
842 CLEAR_HASH(state); /* forget history */
846 if (strm->avail_out == 0) {
847 /* We'll have to come back to get the rest of the output;
848 * this ensures we don't output a second zero-length stored
849 * block (or whatever).
851 state->status = FLUSH_STATE;
856 Assert(strm->avail_out > 0, "bug2");
858 if (flush != Z_FINISH) return Z_OK;
859 if (state->noheader) return Z_STREAM_END;
861 /* Write the zlib trailer (adler32) */
862 putShortMSB(state, (uInt)(state->adler >> 16));
863 putShortMSB(state, (uInt)(state->adler & 0xffff));
865 /* If avail_out is zero, the application will call deflate again
868 state->noheader = -1; /* write the trailer only once! */
869 return state->pending != 0 ? Z_OK : Z_STREAM_END;
872 /* ========================================================================= */
873 int deflateEnd (strm)
876 deflate_state *state = (deflate_state *) strm->state;
878 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
880 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
881 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
882 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
883 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
885 ZFREE(strm, state, sizeof(deflate_state));
886 strm->state = Z_NULL;
891 /* ===========================================================================
892 * Read a new buffer from the current input stream, update the adler32
893 * and total number of bytes read.
895 local int read_buf(strm, buf, size)
900 unsigned len = strm->avail_in;
901 deflate_state *state = (deflate_state *) strm->state;
903 if (len > size) len = size;
904 if (len == 0) return 0;
906 strm->avail_in -= len;
908 if (!state->noheader) {
909 state->adler = adler32(state->adler, strm->next_in, len);
911 zmemcpy(buf, strm->next_in, len);
912 strm->next_in += len;
913 strm->total_in += len;
918 /* ===========================================================================
919 * Initialize the "longest match" routines for a new zlib stream
921 local void lm_init (s)
924 s->window_size = (ulg)2L*s->w_size;
928 /* Set the default configuration parameters:
930 s->max_lazy_match = configuration_table[s->level].max_lazy;
931 s->good_match = configuration_table[s->level].good_length;
932 s->nice_match = configuration_table[s->level].nice_length;
933 s->max_chain_length = configuration_table[s->level].max_chain;
938 s->match_length = MIN_MATCH-1;
939 s->match_available = 0;
942 match_init(); /* initialize the asm code */
946 /* ===========================================================================
947 * Set match_start to the longest match starting at the given string and
948 * return its length. Matches shorter or equal to prev_length are discarded,
949 * in which case the result is equal to prev_length and match_start is
951 * IN assertions: cur_match is the head of the hash chain for the current
952 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
955 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
956 * match.S. The code will be functionally equivalent.
958 local int longest_match(s, cur_match)
960 IPos cur_match; /* current match */
962 unsigned chain_length = s->max_chain_length;/* max hash chain length */
963 register Bytef *scan = s->window + s->strstart; /* current string */
964 register Bytef *match; /* matched string */
965 register int len; /* length of current match */
966 int best_len = s->prev_length; /* best match length so far */
967 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
968 s->strstart - (IPos)MAX_DIST(s) : NIL;
969 /* Stop when cur_match becomes <= limit. To simplify the code,
970 * we prevent matches with the string of window index 0.
972 Posf *prev = s->prev;
973 uInt wmask = s->w_mask;
976 /* Compare two bytes at a time. Note: this is not always beneficial.
977 * Try with and without -DUNALIGNED_OK to check.
979 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
980 register ush scan_start = *(ushf*)scan;
981 register ush scan_end = *(ushf*)(scan+best_len-1);
983 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
984 register Byte scan_end1 = scan[best_len-1];
985 register Byte scan_end = scan[best_len];
988 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
989 * It is easy to get rid of this optimization if necessary.
991 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
993 /* Do not waste too much time if we already have a good match: */
994 if (s->prev_length >= s->good_match) {
997 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1000 Assert(cur_match < s->strstart, "no future");
1001 match = s->window + cur_match;
1003 /* Skip to next match if the match length cannot increase
1004 * or if the match length is less than 2:
1006 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1007 /* This code assumes sizeof(unsigned short) == 2. Do not use
1008 * UNALIGNED_OK if your compiler uses a different size.
1010 if (*(ushf*)(match+best_len-1) != scan_end ||
1011 *(ushf*)match != scan_start) continue;
1013 /* It is not necessary to compare scan[2] and match[2] since they are
1014 * always equal when the other bytes match, given that the hash keys
1015 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1016 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1017 * lookahead only every 4th comparison; the 128th check will be made
1018 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1019 * necessary to put more guard bytes at the end of the window, or
1020 * to check more often for insufficient lookahead.
1022 Assert(scan[2] == match[2], "scan[2]?");
1025 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1026 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1027 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1028 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1030 /* The funny "do {}" generates better code on most compilers */
1032 /* Here, scan <= window+strstart+257 */
1033 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1034 if (*scan == *match) scan++;
1036 len = (MAX_MATCH - 1) - (int)(strend-scan);
1037 scan = strend - (MAX_MATCH-1);
1039 #else /* UNALIGNED_OK */
1041 if (match[best_len] != scan_end ||
1042 match[best_len-1] != scan_end1 ||
1044 *++match != scan[1]) continue;
1046 /* The check at best_len-1 can be removed because it will be made
1047 * again later. (This heuristic is not always a win.)
1048 * It is not necessary to compare scan[2] and match[2] since they
1049 * are always equal when the other bytes match, given that
1050 * the hash keys are equal and that HASH_BITS >= 8.
1053 Assert(*scan == *match, "match[2]?");
1055 /* We check for insufficient lookahead only every 8th comparison;
1056 * the 256th check will be made at strstart+258.
1059 } while (*++scan == *++match && *++scan == *++match &&
1060 *++scan == *++match && *++scan == *++match &&
1061 *++scan == *++match && *++scan == *++match &&
1062 *++scan == *++match && *++scan == *++match &&
1065 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1067 len = MAX_MATCH - (int)(strend - scan);
1068 scan = strend - MAX_MATCH;
1070 #endif /* UNALIGNED_OK */
1072 if (len > best_len) {
1073 s->match_start = cur_match;
1075 if (len >= s->nice_match) break;
1077 scan_end = *(ushf*)(scan+best_len-1);
1079 scan_end1 = scan[best_len-1];
1080 scan_end = scan[best_len];
1083 } while ((cur_match = prev[cur_match & wmask]) > limit
1084 && --chain_length != 0);
1091 /* ===========================================================================
1092 * Check that the match at match_start is indeed a match.
1094 local void check_match(s, start, match, length)
1099 /* check that the match is indeed a match */
1100 if (memcmp((charf *)s->window + match,
1101 (charf *)s->window + start, length) != EQUAL) {
1103 " start %u, match %u, length %d\n",
1104 start, match, length);
1105 do { fprintf(stderr, "%c%c", s->window[match++],
1106 s->window[start++]); } while (--length != 0);
1107 z_error("invalid match");
1110 fprintf(stderr,"\\[%d,%d]", start-match, length);
1111 do { putc(s->window[start++], stderr); } while (--length != 0);
1115 # define check_match(s, start, match, length)
1118 /* ===========================================================================
1119 * Fill the window when the lookahead becomes insufficient.
1120 * Updates strstart and lookahead.
1122 * IN assertion: lookahead < MIN_LOOKAHEAD
1123 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1124 * At least one byte has been read, or avail_in == 0; reads are
1125 * performed for at least two bytes (required for the zip translate_eol
1126 * option -- not supported here).
1128 local void fill_window(s)
1131 register unsigned n, m;
1133 unsigned more; /* Amount of free space at the end of the window. */
1134 uInt wsize = s->w_size;
1137 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1139 /* Deal with !@#$% 64K limit: */
1140 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1142 } else if (more == (unsigned)(-1)) {
1143 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1144 * and lookahead == 1 (input done one byte at time)
1148 /* If the window is almost full and there is insufficient lookahead,
1149 * move the upper half to the lower one to make room in the upper half.
1151 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1153 /* By the IN assertion, the window is not empty so we can't confuse
1154 * more == 0 with more == 64K on a 16 bit machine.
1156 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1158 s->match_start -= wsize;
1159 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1161 s->block_start -= (long) wsize;
1163 /* Slide the hash table (could be avoided with 32 bit values
1164 at the expense of memory usage):
1170 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1177 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1178 /* If n is not on any hash chain, prev[n] is garbage but
1179 * its value will never be used.
1185 if (s->strm->avail_in == 0) return;
1187 /* If there was no sliding:
1188 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1189 * more == window_size - lookahead - strstart
1190 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1191 * => more >= window_size - 2*WSIZE + 2
1192 * In the BIG_MEM or MMAP case (not yet supported),
1193 * window_size == input_size + MIN_LOOKAHEAD &&
1194 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1195 * Otherwise, window_size == 2*WSIZE so more >= 2.
1196 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1198 Assert(more >= 2, "more < 2");
1200 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1204 /* Initialize the hash value now that we have some input: */
1205 if (s->lookahead >= MIN_MATCH) {
1206 s->ins_h = s->window[s->strstart];
1207 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1209 Call UPDATE_HASH() MIN_MATCH-3 more times
1212 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1213 * but this is not important since only literal bytes will be emitted.
1216 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1219 /* ===========================================================================
1220 * Flush the current block, with given end-of-file flag.
1221 * IN assertion: strstart is set to the end of the current match.
1223 #define FLUSH_BLOCK_ONLY(s, flush) { \
1224 ct_flush_block(s, (s->block_start >= 0L ? \
1225 (charf *)&s->window[(unsigned)s->block_start] : \
1226 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1227 s->block_start = s->strstart; \
1228 flush_pending(s->strm); \
1229 Tracev((stderr,"[FLUSH]")); \
1232 /* Same but force premature exit if necessary. */
1233 #define FLUSH_BLOCK(s, flush) { \
1234 FLUSH_BLOCK_ONLY(s, flush); \
1235 if (s->strm->avail_out == 0) return 1; \
1238 /* ===========================================================================
1239 * Compress as much as possible from the input stream, return true if
1240 * processing was terminated prematurely (no more input or output space).
1241 * This function does not perform lazy evaluationof matches and inserts
1242 * new strings in the dictionary only for unmatched strings or for short
1243 * matches. It is used only for the fast compression options.
1245 local int deflate_fast(s, flush)
1249 IPos hash_head = NIL; /* head of the hash chain */
1250 int bflush; /* set if current block must be flushed */
1252 s->prev_length = MIN_MATCH-1;
1255 /* Make sure that we always have enough lookahead, except
1256 * at the end of the input file. We need MAX_MATCH bytes
1257 * for the next match, plus MIN_MATCH bytes to insert the
1258 * string following the next match.
1260 if (s->lookahead < MIN_LOOKAHEAD) {
1262 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1264 if (s->lookahead == 0) break; /* flush the current block */
1267 /* Insert the string window[strstart .. strstart+2] in the
1268 * dictionary, and set hash_head to the head of the hash chain:
1270 if (s->lookahead >= MIN_MATCH) {
1271 INSERT_STRING(s, s->strstart, hash_head);
1274 /* Find the longest match, discarding those <= prev_length.
1275 * At this point we have always match_length < MIN_MATCH
1277 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1278 /* To simplify the code, we prevent matches with the string
1279 * of window index 0 (in particular we have to avoid a match
1280 * of the string with itself at the start of the input file).
1282 if (s->strategy != Z_HUFFMAN_ONLY) {
1283 s->match_length = longest_match (s, hash_head);
1285 /* longest_match() sets match_start */
1287 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1289 if (s->match_length >= MIN_MATCH) {
1290 check_match(s, s->strstart, s->match_start, s->match_length);
1292 bflush = ct_tally(s, s->strstart - s->match_start,
1293 s->match_length - MIN_MATCH);
1295 s->lookahead -= s->match_length;
1297 /* Insert new strings in the hash table only if the match length
1298 * is not too large. This saves time but degrades compression.
1300 if (s->match_length <= s->max_insert_length &&
1301 s->lookahead >= MIN_MATCH) {
1302 s->match_length--; /* string at strstart already in hash table */
1305 INSERT_STRING(s, s->strstart, hash_head);
1306 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1307 * always MIN_MATCH bytes ahead.
1309 } while (--s->match_length != 0);
1312 s->strstart += s->match_length;
1313 s->match_length = 0;
1314 s->ins_h = s->window[s->strstart];
1315 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1317 Call UPDATE_HASH() MIN_MATCH-3 more times
1319 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1320 * matter since it will be recomputed at next deflate call.
1324 /* No match, output a literal byte */
1325 Tracevv((stderr,"%c", s->window[s->strstart]));
1326 bflush = ct_tally (s, 0, s->window[s->strstart]);
1330 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1332 FLUSH_BLOCK(s, flush);
1333 return 0; /* normal exit */
1336 /* ===========================================================================
1337 * Same as above, but achieves better compression. We use a lazy
1338 * evaluation for matches: a match is finally adopted only if there is
1339 * no better match at the next window position.
1341 local int deflate_slow(s, flush)
1345 IPos hash_head = NIL; /* head of hash chain */
1346 int bflush; /* set if current block must be flushed */
1348 /* Process the input block. */
1350 /* Make sure that we always have enough lookahead, except
1351 * at the end of the input file. We need MAX_MATCH bytes
1352 * for the next match, plus MIN_MATCH bytes to insert the
1353 * string following the next match.
1355 if (s->lookahead < MIN_LOOKAHEAD) {
1357 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1359 if (s->lookahead == 0) break; /* flush the current block */
1362 /* Insert the string window[strstart .. strstart+2] in the
1363 * dictionary, and set hash_head to the head of the hash chain:
1365 if (s->lookahead >= MIN_MATCH) {
1366 INSERT_STRING(s, s->strstart, hash_head);
1369 /* Find the longest match, discarding those <= prev_length.
1371 s->prev_length = s->match_length, s->prev_match = s->match_start;
1372 s->match_length = MIN_MATCH-1;
1374 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1375 s->strstart - hash_head <= MAX_DIST(s)) {
1376 /* To simplify the code, we prevent matches with the string
1377 * of window index 0 (in particular we have to avoid a match
1378 * of the string with itself at the start of the input file).
1380 if (s->strategy != Z_HUFFMAN_ONLY) {
1381 s->match_length = longest_match (s, hash_head);
1383 /* longest_match() sets match_start */
1384 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1386 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1387 (s->match_length == MIN_MATCH &&
1388 s->strstart - s->match_start > TOO_FAR))) {
1390 /* If prev_match is also MIN_MATCH, match_start is garbage
1391 * but we will ignore the current match anyway.
1393 s->match_length = MIN_MATCH-1;
1396 /* If there was a match at the previous step and the current
1397 * match is not better, output the previous match:
1399 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1400 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1401 /* Do not insert strings in hash table beyond this. */
1403 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1405 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1406 s->prev_length - MIN_MATCH);
1408 /* Insert in hash table all strings up to the end of the match.
1409 * strstart-1 and strstart are already inserted. If there is not
1410 * enough lookahead, the last two strings are not inserted in
1413 s->lookahead -= s->prev_length-1;
1414 s->prev_length -= 2;
1416 if (++s->strstart <= max_insert) {
1417 INSERT_STRING(s, s->strstart, hash_head);
1419 } while (--s->prev_length != 0);
1420 s->match_available = 0;
1421 s->match_length = MIN_MATCH-1;
1424 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1426 } else if (s->match_available) {
1427 /* If there was no match at the previous position, output a
1428 * single literal. If there was a match but the current match
1429 * is longer, truncate the previous match to a single literal.
1431 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1432 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1433 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1437 if (s->strm->avail_out == 0) return 1;
1439 /* There is no previous match to compare with, wait for
1440 * the next step to decide.
1442 s->match_available = 1;
1447 Assert (flush != Z_NO_FLUSH, "no flush?");
1448 if (s->match_available) {
1449 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1450 ct_tally (s, 0, s->window[s->strstart-1]);
1451 s->match_available = 0;
1453 FLUSH_BLOCK(s, flush);
1459 /* trees.c -- output deflated data using Huffman coding
1460 * Copyright (C) 1995 Jean-loup Gailly
1461 * For conditions of distribution and use, see copyright notice in zlib.h
1467 * The "deflation" process uses several Huffman trees. The more
1468 * common source values are represented by shorter bit sequences.
1470 * Each code tree is stored in a compressed form which is itself
1471 * a Huffman encoding of the lengths of all the code strings (in
1472 * ascending order by source values). The actual code strings are
1473 * reconstructed from the lengths in the inflate process, as described
1474 * in the deflate specification.
1478 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1479 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1482 * Data Compression: Methods and Theory, pp. 49-50.
1483 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1487 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1490 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
1496 /* ===========================================================================
1500 #define MAX_BL_BITS 7
1501 /* Bit length codes must not exceed MAX_BL_BITS bits */
1503 #define END_BLOCK 256
1504 /* end of block literal code */
1507 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1509 #define REPZ_3_10 17
1510 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1512 #define REPZ_11_138 18
1513 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1515 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1516 = {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};
1518 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1519 = {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};
1521 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1522 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1524 local uch bl_order[BL_CODES]
1525 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1526 /* The lengths of the bit length codes are sent in order of decreasing
1527 * probability, to avoid transmitting the lengths for unused bit length codes.
1530 #define Buf_size (8 * 2*sizeof(char))
1531 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1532 * more than 16 bits on some systems.)
1535 /* ===========================================================================
1536 * Local data. These are initialized only once.
1537 * To do: initialize at compile time to be completely reentrant. ???
1540 local ct_data static_ltree[L_CODES+2];
1541 /* The static literal tree. Since the bit lengths are imposed, there is no
1542 * need for the L_CODES extra codes used during heap construction. However
1543 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1547 local ct_data static_dtree[D_CODES];
1548 /* The static distance tree. (Actually a trivial tree since all codes use
1552 local uch dist_code[512];
1553 /* distance codes. The first 256 values correspond to the distances
1554 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1555 * the 15 bit distances.
1558 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1559 /* length code for each normalized match length (0 == MIN_MATCH) */
1561 local int base_length[LENGTH_CODES];
1562 /* First normalized length for each code (0 = MIN_MATCH) */
1564 local int base_dist[D_CODES];
1565 /* First normalized distance for each code (0 = distance of 1) */
1567 struct static_tree_desc_s {
1568 ct_data *static_tree; /* static tree or NULL */
1569 intf *extra_bits; /* extra bits for each code or NULL */
1570 int extra_base; /* base index for extra_bits */
1571 int elems; /* max number of elements in the tree */
1572 int max_length; /* max bit length for the codes */
1575 local static_tree_desc static_l_desc =
1576 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1578 local static_tree_desc static_d_desc =
1579 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1581 local static_tree_desc static_bl_desc =
1582 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1584 /* ===========================================================================
1585 * Local (static) routines in this file.
1588 local void ct_static_init OF((void));
1589 local void init_block OF((deflate_state *s));
1590 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1591 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1592 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1593 local void build_tree OF((deflate_state *s, tree_desc *desc));
1594 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1595 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1596 local int build_bl_tree OF((deflate_state *s));
1597 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1599 local void compress_block OF((deflate_state *s, ct_data *ltree,
1601 local void set_data_type OF((deflate_state *s));
1602 local unsigned bi_reverse OF((unsigned value, int length));
1603 local void bi_windup OF((deflate_state *s));
1604 local void bi_flush OF((deflate_state *s));
1605 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1609 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1610 /* Send a code of the given tree. c and tree must not have side effects */
1612 #else /* DEBUG_ZLIB */
1613 # define send_code(s, c, tree) \
1614 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1615 send_bits(s, tree[c].Code, tree[c].Len); }
1618 #define d_code(dist) \
1619 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1620 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1621 * must not have side effects. dist_code[256] and dist_code[257] are never
1625 /* ===========================================================================
1626 * Output a short LSB first on the stream.
1627 * IN assertion: there is enough room in pendingBuf.
1629 #define put_short(s, w) { \
1630 put_byte(s, (uch)((w) & 0xff)); \
1631 put_byte(s, (uch)((ush)(w) >> 8)); \
1634 /* ===========================================================================
1635 * Send a value on a given number of bits.
1636 * IN assertion: length <= 16 and value fits in length bits.
1639 local void send_bits OF((deflate_state *s, int value, int length));
1641 local void send_bits(s, value, length)
1643 int value; /* value to send */
1644 int length; /* number of bits */
1646 Tracev((stderr," l %2d v %4x ", length, value));
1647 Assert(length > 0 && length <= 15, "invalid length");
1648 s->bits_sent += (ulg)length;
1650 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1651 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1652 * unused bits in value.
1654 if (s->bi_valid > (int)Buf_size - length) {
1655 s->bi_buf |= (value << s->bi_valid);
1656 put_short(s, s->bi_buf);
1657 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1658 s->bi_valid += length - Buf_size;
1660 s->bi_buf |= value << s->bi_valid;
1661 s->bi_valid += length;
1664 #else /* !DEBUG_ZLIB */
1666 #define send_bits(s, value, length) \
1667 { int len = length;\
1668 if (s->bi_valid > (int)Buf_size - len) {\
1670 s->bi_buf |= (val << s->bi_valid);\
1671 put_short(s, s->bi_buf);\
1672 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1673 s->bi_valid += len - Buf_size;\
1675 s->bi_buf |= (value) << s->bi_valid;\
1676 s->bi_valid += len;\
1679 #endif /* DEBUG_ZLIB */
1682 #define MAX(a,b) (a >= b ? a : b)
1683 /* the arguments must not have side effects */
1685 /* ===========================================================================
1686 * Initialize the various 'constant' tables.
1687 * To do: do this at compile time.
1689 local void ct_static_init()
1691 int n; /* iterates over tree elements */
1692 int bits; /* bit counter */
1693 int length; /* length value */
1694 int code; /* code value */
1695 int dist; /* distance index */
1696 ush bl_count[MAX_BITS+1];
1697 /* number of codes at each bit length for an optimal tree */
1699 /* Initialize the mapping length (0..255) -> length code (0..28) */
1701 for (code = 0; code < LENGTH_CODES-1; code++) {
1702 base_length[code] = length;
1703 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1704 length_code[length++] = (uch)code;
1707 Assert (length == 256, "ct_static_init: length != 256");
1708 /* Note that the length 255 (match length 258) can be represented
1709 * in two different ways: code 284 + 5 bits or code 285, so we
1710 * overwrite length_code[255] to use the best encoding:
1712 length_code[length-1] = (uch)code;
1714 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1716 for (code = 0 ; code < 16; code++) {
1717 base_dist[code] = dist;
1718 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1719 dist_code[dist++] = (uch)code;
1722 Assert (dist == 256, "ct_static_init: dist != 256");
1723 dist >>= 7; /* from now on, all distances are divided by 128 */
1724 for ( ; code < D_CODES; code++) {
1725 base_dist[code] = dist << 7;
1726 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1727 dist_code[256 + dist++] = (uch)code;
1730 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1732 /* Construct the codes of the static literal tree */
1733 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1735 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1736 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1737 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1738 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1739 /* Codes 286 and 287 do not exist, but we must include them in the
1740 * tree construction to get a canonical Huffman tree (longest code
1743 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1745 /* The static distance tree is trivial: */
1746 for (n = 0; n < D_CODES; n++) {
1747 static_dtree[n].Len = 5;
1748 static_dtree[n].Code = bi_reverse(n, 5);
1752 /* ===========================================================================
1753 * Initialize the tree data structures for a new zlib stream.
1755 local void ct_init(s)
1758 if (static_dtree[0].Len == 0) {
1759 ct_static_init(); /* To do: at compile time */
1762 s->compressed_len = 0L;
1764 s->l_desc.dyn_tree = s->dyn_ltree;
1765 s->l_desc.stat_desc = &static_l_desc;
1767 s->d_desc.dyn_tree = s->dyn_dtree;
1768 s->d_desc.stat_desc = &static_d_desc;
1770 s->bl_desc.dyn_tree = s->bl_tree;
1771 s->bl_desc.stat_desc = &static_bl_desc;
1775 s->last_eob_len = 8; /* enough lookahead for inflate */
1779 s->blocks_in_packet = 0;
1781 /* Initialize the first block of the first file: */
1785 /* ===========================================================================
1786 * Initialize a new block.
1788 local void init_block(s)
1791 int n; /* iterates over tree elements */
1793 /* Initialize the trees. */
1794 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1795 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1796 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1798 s->dyn_ltree[END_BLOCK].Freq = 1;
1799 s->opt_len = s->static_len = 0L;
1800 s->last_lit = s->matches = 0;
1804 /* Index within the heap array of least frequent node in the Huffman tree */
1807 /* ===========================================================================
1808 * Remove the smallest element from the heap and recreate the heap with
1809 * one less element. Updates heap and heap_len.
1811 #define pqremove(s, tree, top) \
1813 top = s->heap[SMALLEST]; \
1814 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1815 pqdownheap(s, tree, SMALLEST); \
1818 /* ===========================================================================
1819 * Compares to subtrees, using the tree depth as tie breaker when
1820 * the subtrees have equal frequency. This minimizes the worst case length.
1822 #define smaller(tree, n, m, depth) \
1823 (tree[n].Freq < tree[m].Freq || \
1824 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1826 /* ===========================================================================
1827 * Restore the heap property by moving down the tree starting at node k,
1828 * exchanging a node with the smallest of its two sons if necessary, stopping
1829 * when the heap property is re-established (each father smaller than its
1832 local void pqdownheap(s, tree, k)
1834 ct_data *tree; /* the tree to restore */
1835 int k; /* node to move down */
1838 int j = k << 1; /* left son of k */
1839 while (j <= s->heap_len) {
1840 /* Set j to the smallest of the two sons: */
1841 if (j < s->heap_len &&
1842 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1845 /* Exit if v is smaller than both sons */
1846 if (smaller(tree, v, s->heap[j], s->depth)) break;
1848 /* Exchange v with the smallest son */
1849 s->heap[k] = s->heap[j]; k = j;
1851 /* And continue down the tree, setting j to the left son of k */
1857 /* ===========================================================================
1858 * Compute the optimal bit lengths for a tree and update the total bit length
1859 * for the current block.
1860 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1861 * above are the tree nodes sorted by increasing frequency.
1862 * OUT assertions: the field len is set to the optimal bit length, the
1863 * array bl_count contains the frequencies for each bit length.
1864 * The length opt_len is updated; static_len is also updated if stree is
1867 local void gen_bitlen(s, desc)
1869 tree_desc *desc; /* the tree descriptor */
1871 ct_data *tree = desc->dyn_tree;
1872 int max_code = desc->max_code;
1873 ct_data *stree = desc->stat_desc->static_tree;
1874 intf *extra = desc->stat_desc->extra_bits;
1875 int base = desc->stat_desc->extra_base;
1876 int max_length = desc->stat_desc->max_length;
1877 int h; /* heap index */
1878 int n, m; /* iterate over the tree elements */
1879 int bits; /* bit length */
1880 int xbits; /* extra bits */
1881 ush f; /* frequency */
1882 int overflow = 0; /* number of elements with bit length too large */
1884 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1886 /* In a first pass, compute the optimal bit lengths (which may
1887 * overflow in the case of the bit length tree).
1889 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1891 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1893 bits = tree[tree[n].Dad].Len + 1;
1894 if (bits > max_length) bits = max_length, overflow++;
1895 tree[n].Len = (ush)bits;
1896 /* We overwrite tree[n].Dad which is no longer needed */
1898 if (n > max_code) continue; /* not a leaf node */
1900 s->bl_count[bits]++;
1902 if (n >= base) xbits = extra[n-base];
1904 s->opt_len += (ulg)f * (bits + xbits);
1905 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1907 if (overflow == 0) return;
1909 Trace((stderr,"\nbit length overflow\n"));
1910 /* This happens for example on obj2 and pic of the Calgary corpus */
1912 /* Find the first bit length which could increase: */
1914 bits = max_length-1;
1915 while (s->bl_count[bits] == 0) bits--;
1916 s->bl_count[bits]--; /* move one leaf down the tree */
1917 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1918 s->bl_count[max_length]--;
1919 /* The brother of the overflow item also moves one step up,
1920 * but this does not affect bl_count[max_length]
1923 } while (overflow > 0);
1925 /* Now recompute all bit lengths, scanning in increasing frequency.
1926 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1927 * lengths instead of fixing only the wrong ones. This idea is taken
1928 * from 'ar' written by Haruhiko Okumura.)
1930 for (bits = max_length; bits != 0; bits--) {
1931 n = s->bl_count[bits];
1934 if (m > max_code) continue;
1935 if (tree[m].Len != (unsigned) bits) {
1936 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1937 s->opt_len += ((long)bits - (long)tree[m].Len)
1938 *(long)tree[m].Freq;
1939 tree[m].Len = (ush)bits;
1946 /* ===========================================================================
1947 * Generate the codes for a given tree and bit counts (which need not be
1949 * IN assertion: the array bl_count contains the bit length statistics for
1950 * the given tree and the field len is set for all tree elements.
1951 * OUT assertion: the field code is set for all tree elements of non
1954 local void gen_codes (tree, max_code, bl_count)
1955 ct_data *tree; /* the tree to decorate */
1956 int max_code; /* largest code with non zero frequency */
1957 ushf *bl_count; /* number of codes at each bit length */
1959 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1960 ush code = 0; /* running code value */
1961 int bits; /* bit index */
1962 int n; /* code index */
1964 /* The distribution counts are first used to generate the code values
1965 * without bit reversal.
1967 for (bits = 1; bits <= MAX_BITS; bits++) {
1968 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1970 /* Check that the bit counts in bl_count are consistent. The last code
1973 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1974 "inconsistent bit counts");
1975 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1977 for (n = 0; n <= max_code; n++) {
1978 int len = tree[n].Len;
1979 if (len == 0) continue;
1980 /* Now reverse the bits */
1981 tree[n].Code = bi_reverse(next_code[len]++, len);
1983 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1984 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1988 /* ===========================================================================
1989 * Construct one Huffman tree and assigns the code bit strings and lengths.
1990 * Update the total bit length for the current block.
1991 * IN assertion: the field freq is set for all tree elements.
1992 * OUT assertions: the fields len and code are set to the optimal bit length
1993 * and corresponding code. The length opt_len is updated; static_len is
1994 * also updated if stree is not null. The field max_code is set.
1996 local void build_tree(s, desc)
1998 tree_desc *desc; /* the tree descriptor */
2000 ct_data *tree = desc->dyn_tree;
2001 ct_data *stree = desc->stat_desc->static_tree;
2002 int elems = desc->stat_desc->elems;
2003 int n, m; /* iterate over heap elements */
2004 int max_code = -1; /* largest code with non zero frequency */
2005 int node; /* new node being created */
2007 /* Construct the initial heap, with least frequent element in
2008 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2009 * heap[0] is not used.
2011 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2013 for (n = 0; n < elems; n++) {
2014 if (tree[n].Freq != 0) {
2015 s->heap[++(s->heap_len)] = max_code = n;
2022 /* The pkzip format requires that at least one distance code exists,
2023 * and that at least one bit should be sent even if there is only one
2024 * possible code. So to avoid special checks later on we force at least
2025 * two codes of non zero frequency.
2027 while (s->heap_len < 2) {
2028 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2029 tree[node].Freq = 1;
2031 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2032 /* node is 0 or 1 so it does not have extra bits */
2034 desc->max_code = max_code;
2036 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2037 * establish sub-heaps of increasing lengths:
2039 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2041 /* Construct the Huffman tree by repeatedly combining the least two
2044 node = elems; /* next internal node of the tree */
2046 pqremove(s, tree, n); /* n = node of least frequency */
2047 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2049 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2050 s->heap[--(s->heap_max)] = m;
2052 /* Create a new node father of n and m */
2053 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2054 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2055 tree[n].Dad = tree[m].Dad = (ush)node;
2057 if (tree == s->bl_tree) {
2058 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2059 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2062 /* and insert the new node in the heap */
2063 s->heap[SMALLEST] = node++;
2064 pqdownheap(s, tree, SMALLEST);
2066 } while (s->heap_len >= 2);
2068 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2070 /* At this point, the fields freq and dad are set. We can now
2071 * generate the bit lengths.
2073 gen_bitlen(s, (tree_desc *)desc);
2075 /* The field len is now set, we can generate the bit codes */
2076 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2079 /* ===========================================================================
2080 * Scan a literal or distance tree to determine the frequencies of the codes
2081 * in the bit length tree.
2083 local void scan_tree (s, tree, max_code)
2085 ct_data *tree; /* the tree to be scanned */
2086 int max_code; /* and its largest code of non zero frequency */
2088 int n; /* iterates over all tree elements */
2089 int prevlen = -1; /* last emitted length */
2090 int curlen; /* length of current code */
2091 int nextlen = tree[0].Len; /* length of next code */
2092 int count = 0; /* repeat count of the current code */
2093 int max_count = 7; /* max repeat count */
2094 int min_count = 4; /* min repeat count */
2096 if (nextlen == 0) max_count = 138, min_count = 3;
2097 tree[max_code+1].Len = (ush)0xffff; /* guard */
2099 for (n = 0; n <= max_code; n++) {
2100 curlen = nextlen; nextlen = tree[n+1].Len;
2101 if (++count < max_count && curlen == nextlen) {
2103 } else if (count < min_count) {
2104 s->bl_tree[curlen].Freq += count;
2105 } else if (curlen != 0) {
2106 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2107 s->bl_tree[REP_3_6].Freq++;
2108 } else if (count <= 10) {
2109 s->bl_tree[REPZ_3_10].Freq++;
2111 s->bl_tree[REPZ_11_138].Freq++;
2113 count = 0; prevlen = curlen;
2115 max_count = 138, min_count = 3;
2116 } else if (curlen == nextlen) {
2117 max_count = 6, min_count = 3;
2119 max_count = 7, min_count = 4;
2124 /* ===========================================================================
2125 * Send a literal or distance tree in compressed form, using the codes in
2128 local void send_tree (s, tree, max_code)
2130 ct_data *tree; /* the tree to be scanned */
2131 int max_code; /* and its largest code of non zero frequency */
2133 int n; /* iterates over all tree elements */
2134 int prevlen = -1; /* last emitted length */
2135 int curlen; /* length of current code */
2136 int nextlen = tree[0].Len; /* length of next code */
2137 int count = 0; /* repeat count of the current code */
2138 int max_count = 7; /* max repeat count */
2139 int min_count = 4; /* min repeat count */
2141 /* tree[max_code+1].Len = -1; */ /* guard already set */
2142 if (nextlen == 0) max_count = 138, min_count = 3;
2144 for (n = 0; n <= max_code; n++) {
2145 curlen = nextlen; nextlen = tree[n+1].Len;
2146 if (++count < max_count && curlen == nextlen) {
2148 } else if (count < min_count) {
2149 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2151 } else if (curlen != 0) {
2152 if (curlen != prevlen) {
2153 send_code(s, curlen, s->bl_tree); count--;
2155 Assert(count >= 3 && count <= 6, " 3_6?");
2156 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2158 } else if (count <= 10) {
2159 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2162 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2164 count = 0; prevlen = curlen;
2166 max_count = 138, min_count = 3;
2167 } else if (curlen == nextlen) {
2168 max_count = 6, min_count = 3;
2170 max_count = 7, min_count = 4;
2175 /* ===========================================================================
2176 * Construct the Huffman tree for the bit lengths and return the index in
2177 * bl_order of the last bit length code to send.
2179 local int build_bl_tree(s)
2182 int max_blindex; /* index of last bit length code of non zero freq */
2184 /* Determine the bit length frequencies for literal and distance trees */
2185 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2186 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2188 /* Build the bit length tree: */
2189 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2190 /* opt_len now includes the length of the tree representations, except
2191 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2194 /* Determine the number of bit length codes to send. The pkzip format
2195 * requires that at least 4 bit length codes be sent. (appnote.txt says
2196 * 3 but the actual value used is 4.)
2198 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2199 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2201 /* Update opt_len to include the bit length tree and counts */
2202 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2203 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2204 s->opt_len, s->static_len));
2209 /* ===========================================================================
2210 * Send the header for a block using dynamic Huffman trees: the counts, the
2211 * lengths of the bit length codes, the literal tree and the distance tree.
2212 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2214 local void send_all_trees(s, lcodes, dcodes, blcodes)
2216 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2218 int rank; /* index in bl_order */
2220 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2221 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2223 Tracev((stderr, "\nbl counts: "));
2224 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2225 send_bits(s, dcodes-1, 5);
2226 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2227 for (rank = 0; rank < blcodes; rank++) {
2228 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2229 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2231 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2233 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2234 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2236 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2237 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2240 /* ===========================================================================
2241 * Send a stored block
2243 local void ct_stored_block(s, buf, stored_len, eof)
2245 charf *buf; /* input block */
2246 ulg stored_len; /* length of input block */
2247 int eof; /* true if this is the last block for a file */
2249 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2250 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2251 s->compressed_len += (stored_len + 4) << 3;
2253 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2256 /* Send just the `stored block' type code without any length bytes or data.
2258 local void ct_stored_type_only(s)
2261 send_bits(s, (STORED_BLOCK << 1), 3);
2263 s->compressed_len = (s->compressed_len + 3) & ~7L;
2267 /* ===========================================================================
2268 * Send one empty static block to give enough lookahead for inflate.
2269 * This takes 10 bits, of which 7 may remain in the bit buffer.
2270 * The current inflate code requires 9 bits of lookahead. If the EOB
2271 * code for the previous block was coded on 5 bits or less, inflate
2272 * may have only 5+3 bits of lookahead to decode this EOB.
2273 * (There are no problems if the previous block is stored or fixed.)
2275 local void ct_align(s)
2278 send_bits(s, STATIC_TREES<<1, 3);
2279 send_code(s, END_BLOCK, static_ltree);
2280 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2282 /* Of the 10 bits for the empty block, we have already sent
2283 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2284 * block was thus its length plus what we have just sent.
2286 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2287 send_bits(s, STATIC_TREES<<1, 3);
2288 send_code(s, END_BLOCK, static_ltree);
2289 s->compressed_len += 10L;
2292 s->last_eob_len = 7;
2295 /* ===========================================================================
2296 * Determine the best encoding for the current block: dynamic trees, static
2297 * trees or store, and output the encoded block to the zip file. This function
2298 * returns the total compressed length for the file so far.
2300 local ulg ct_flush_block(s, buf, stored_len, flush)
2302 charf *buf; /* input block, or NULL if too old */
2303 ulg stored_len; /* length of input block */
2304 int flush; /* Z_FINISH if this is the last block for a file */
2306 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2307 int max_blindex; /* index of last bit length code of non zero freq */
2308 int eof = flush == Z_FINISH;
2310 ++s->blocks_in_packet;
2312 /* Check if the file is ascii or binary */
2313 if (s->data_type == UNKNOWN) set_data_type(s);
2315 /* Construct the literal and distance trees */
2316 build_tree(s, (tree_desc *)(&(s->l_desc)));
2317 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2320 build_tree(s, (tree_desc *)(&(s->d_desc)));
2321 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2323 /* At this point, opt_len and static_len are the total bit lengths of
2324 * the compressed block data, excluding the tree representations.
2327 /* Build the bit length tree for the above two trees, and get the index
2328 * in bl_order of the last bit length code to send.
2330 max_blindex = build_bl_tree(s);
2332 /* Determine the best encoding. Compute first the block length in bytes */
2333 opt_lenb = (s->opt_len+3+7)>>3;
2334 static_lenb = (s->static_len+3+7)>>3;
2336 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2337 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2340 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2342 /* If compression failed and this is the first and last block,
2343 * and if the .zip file can be seeked (to rewrite the local header),
2344 * the whole file is transformed into a stored file:
2346 #ifdef STORED_FILE_OK
2347 # ifdef FORCE_STORED_FILE
2348 if (eof && compressed_len == 0L) /* force stored file */
2350 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2353 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2354 if (buf == (charf*)0) error ("block vanished");
2356 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2357 s->compressed_len = stored_len << 3;
2360 #endif /* STORED_FILE_OK */
2362 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
2363 * compression, and this block contains all the data since the last
2364 * time we used Z_PACKET_FLUSH, then just omit this block completely
2367 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
2368 && opt_lenb > stored_len - s->minCompr) {
2369 s->blocks_in_packet = 0;
2370 /* output nothing */
2374 if (buf != (char*)0) /* force stored block */
2376 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2377 /* 4: two words for the lengths */
2380 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2381 * Otherwise we can't have processed more than WSIZE input bytes since
2382 * the last block flush, because compression would have been
2383 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2384 * transform a block into a stored block.
2386 ct_stored_block(s, buf, stored_len, eof);
2390 if (static_lenb >= 0) /* force static trees */
2392 if (static_lenb == opt_lenb)
2395 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2396 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2397 s->compressed_len += 3 + s->static_len;
2399 send_bits(s, (DYN_TREES<<1)+eof, 3);
2400 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2402 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2403 s->compressed_len += 3 + s->opt_len;
2405 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2410 s->compressed_len += 7; /* align on byte boundary */
2412 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2413 s->compressed_len-7*eof));
2415 return s->compressed_len >> 3;
2418 /* ===========================================================================
2419 * Save the match info and tally the frequency counts. Return true if
2420 * the current block must be flushed.
2422 local int ct_tally (s, dist, lc)
2424 int dist; /* distance of matched string */
2425 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2427 s->d_buf[s->last_lit] = (ush)dist;
2428 s->l_buf[s->last_lit++] = (uch)lc;
2430 /* lc is the unmatched char */
2431 s->dyn_ltree[lc].Freq++;
2434 /* Here, lc is the match length - MIN_MATCH */
2435 dist--; /* dist = match distance - 1 */
2436 Assert((ush)dist < (ush)MAX_DIST(s) &&
2437 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2438 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2440 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2441 s->dyn_dtree[d_code(dist)].Freq++;
2444 /* Try to guess if it is profitable to stop the current block here */
2445 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2446 /* Compute an upper bound for the compressed length */
2447 ulg out_length = (ulg)s->last_lit*8L;
2448 ulg in_length = (ulg)s->strstart - s->block_start;
2450 for (dcode = 0; dcode < D_CODES; dcode++) {
2451 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2452 (5L+extra_dbits[dcode]);
2455 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2456 s->last_lit, in_length, out_length,
2457 100L - out_length*100L/in_length));
2458 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2460 return (s->last_lit == s->lit_bufsize-1);
2461 /* We avoid equality with lit_bufsize because of wraparound at 64K
2462 * on 16 bit machines and because stored blocks are restricted to
2467 /* ===========================================================================
2468 * Send the block data compressed using the given Huffman trees
2470 local void compress_block(s, ltree, dtree)
2472 ct_data *ltree; /* literal tree */
2473 ct_data *dtree; /* distance tree */
2475 unsigned dist; /* distance of matched string */
2476 int lc; /* match length or unmatched char (if dist == 0) */
2477 unsigned lx = 0; /* running index in l_buf */
2478 unsigned code; /* the code to send */
2479 int extra; /* number of extra bits to send */
2481 if (s->last_lit != 0) do {
2482 dist = s->d_buf[lx];
2483 lc = s->l_buf[lx++];
2485 send_code(s, lc, ltree); /* send a literal byte */
2486 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2488 /* Here, lc is the match length - MIN_MATCH */
2489 code = length_code[lc];
2490 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2491 extra = extra_lbits[code];
2493 lc -= base_length[code];
2494 send_bits(s, lc, extra); /* send the extra length bits */
2496 dist--; /* dist is now the match distance - 1 */
2497 code = d_code(dist);
2498 Assert (code < D_CODES, "bad d_code");
2500 send_code(s, code, dtree); /* send the distance code */
2501 extra = extra_dbits[code];
2503 dist -= base_dist[code];
2504 send_bits(s, dist, extra); /* send the extra distance bits */
2506 } /* literal or match pair ? */
2508 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2509 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2511 } while (lx < s->last_lit);
2513 send_code(s, END_BLOCK, ltree);
2514 s->last_eob_len = ltree[END_BLOCK].Len;
2517 /* ===========================================================================
2518 * Set the data type to ASCII or BINARY, using a crude approximation:
2519 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2520 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2521 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2523 local void set_data_type(s)
2527 unsigned ascii_freq = 0;
2528 unsigned bin_freq = 0;
2529 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2530 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2531 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2532 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2535 /* ===========================================================================
2536 * Reverse the first len bits of a code, using straightforward code (a faster
2537 * method would use a table)
2538 * IN assertion: 1 <= len <= 15
2540 local unsigned bi_reverse(code, len)
2541 unsigned code; /* the value to invert */
2542 int len; /* its bit length */
2544 register unsigned res = 0;
2547 code >>= 1, res <<= 1;
2548 } while (--len > 0);
2552 /* ===========================================================================
2553 * Flush the bit buffer, keeping at most 7 bits in it.
2555 local void bi_flush(s)
2558 if (s->bi_valid == 16) {
2559 put_short(s, s->bi_buf);
2562 } else if (s->bi_valid >= 8) {
2563 put_byte(s, (Byte)s->bi_buf);
2569 /* ===========================================================================
2570 * Flush the bit buffer and align the output on a byte boundary
2572 local void bi_windup(s)
2575 if (s->bi_valid > 8) {
2576 put_short(s, s->bi_buf);
2577 } else if (s->bi_valid > 0) {
2578 put_byte(s, (Byte)s->bi_buf);
2583 s->bits_sent = (s->bits_sent+7) & ~7;
2587 /* ===========================================================================
2588 * Copy a stored block, storing first the length and its
2589 * one's complement if requested.
2591 local void copy_block(s, buf, len, header)
2593 charf *buf; /* the input data */
2594 unsigned len; /* its length */
2595 int header; /* true if block header must be written */
2597 bi_windup(s); /* align on byte boundary */
2598 s->last_eob_len = 8; /* enough lookahead for inflate */
2601 put_short(s, (ush)len);
2602 put_short(s, (ush)~len);
2604 s->bits_sent += 2*16;
2608 s->bits_sent += (ulg)len<<3;
2611 put_byte(s, *buf++);
2617 /* infblock.h -- header to use infblock.c
2618 * Copyright (C) 1995 Mark Adler
2619 * For conditions of distribution and use, see copyright notice in zlib.h
2622 /* WARNING: this file should *not* be used by applications. It is
2623 part of the implementation of the compression library and is
2624 subject to change. Applications should only use zlib.h.
2627 struct inflate_blocks_state;
2628 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2630 local inflate_blocks_statef * inflate_blocks_new OF((
2632 check_func c, /* check function */
2633 uInt w)); /* window size */
2635 local int inflate_blocks OF((
2636 inflate_blocks_statef *,
2638 int)); /* initial return code */
2640 local void inflate_blocks_reset OF((
2641 inflate_blocks_statef *,
2643 uLongf *)); /* check value on output */
2645 local int inflate_blocks_free OF((
2646 inflate_blocks_statef *,
2648 uLongf *)); /* check value on output */
2650 local int inflate_addhistory OF((
2651 inflate_blocks_statef *,
2654 local int inflate_packet_flush OF((
2655 inflate_blocks_statef *));
2658 /* inftrees.h -- header to use inftrees.c
2659 * Copyright (C) 1995 Mark Adler
2660 * For conditions of distribution and use, see copyright notice in zlib.h
2663 /* WARNING: this file should *not* be used by applications. It is
2664 part of the implementation of the compression library and is
2665 subject to change. Applications should only use zlib.h.
2668 /* Huffman code lookup table entry--this entry is four bytes for machines
2669 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2671 typedef struct inflate_huft_s FAR inflate_huft;
2673 struct inflate_huft_s {
2676 Byte Exop; /* number of extra bits or operation */
2677 Byte Bits; /* number of bits in this code or subcode */
2679 uInt Nalloc; /* number of these allocated here */
2680 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2681 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2683 uInt Base; /* literal, length base, or distance base */
2684 inflate_huft *Next; /* pointer to next level of table */
2689 local uInt inflate_hufts;
2692 local int inflate_trees_bits OF((
2693 uIntf *, /* 19 code lengths */
2694 uIntf *, /* bits tree desired/actual depth */
2695 inflate_huft * FAR *, /* bits tree result */
2696 z_stream *)); /* for zalloc, zfree functions */
2698 local int inflate_trees_dynamic OF((
2699 uInt, /* number of literal/length codes */
2700 uInt, /* number of distance codes */
2701 uIntf *, /* that many (total) code lengths */
2702 uIntf *, /* literal desired/actual bit depth */
2703 uIntf *, /* distance desired/actual bit depth */
2704 inflate_huft * FAR *, /* literal/length tree result */
2705 inflate_huft * FAR *, /* distance tree result */
2706 z_stream *)); /* for zalloc, zfree functions */
2708 local int inflate_trees_fixed OF((
2709 uIntf *, /* literal desired/actual bit depth */
2710 uIntf *, /* distance desired/actual bit depth */
2711 inflate_huft * FAR *, /* literal/length tree result */
2712 inflate_huft * FAR *)); /* distance tree result */
2714 local int inflate_trees_free OF((
2715 inflate_huft *, /* tables to free */
2716 z_stream *)); /* for zfree function */
2720 /* infcodes.h -- header to use infcodes.c
2721 * Copyright (C) 1995 Mark Adler
2722 * For conditions of distribution and use, see copyright notice in zlib.h
2725 /* WARNING: this file should *not* be used by applications. It is
2726 part of the implementation of the compression library and is
2727 subject to change. Applications should only use zlib.h.
2730 struct inflate_codes_state;
2731 typedef struct inflate_codes_state FAR inflate_codes_statef;
2733 local inflate_codes_statef *inflate_codes_new OF((
2735 inflate_huft *, inflate_huft *,
2738 local int inflate_codes OF((
2739 inflate_blocks_statef *,
2743 local void inflate_codes_free OF((
2744 inflate_codes_statef *,
2749 /* inflate.c -- zlib interface to inflate modules
2750 * Copyright (C) 1995 Mark Adler
2751 * For conditions of distribution and use, see copyright notice in zlib.h
2754 /* inflate private state */
2755 struct internal_state {
2759 METHOD, /* waiting for method byte */
2760 FLAG, /* waiting for flag byte */
2761 BLOCKS, /* decompressing blocks */
2762 CHECK4, /* four check bytes to go */
2763 CHECK3, /* three check bytes to go */
2764 CHECK2, /* two check bytes to go */
2765 CHECK1, /* one check byte to go */
2766 DONE, /* finished check, done */
2767 BAD} /* got an error--stay here */
2768 mode; /* current inflate mode */
2770 /* mode dependent information */
2772 uInt method; /* if FLAGS, method byte */
2774 uLong was; /* computed check value */
2775 uLong need; /* stream check value */
2776 } check; /* if CHECK, check values to compare */
2777 uInt marker; /* if BAD, inflateSync's marker bytes count */
2778 } sub; /* submode */
2780 /* mode independent information */
2781 int nowrap; /* flag for no wrapper */
2782 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2783 inflate_blocks_statef
2784 *blocks; /* current inflate_blocks state */
2794 if (z == Z_NULL || z->state == Z_NULL)
2795 return Z_STREAM_ERROR;
2796 z->total_in = z->total_out = 0;
2798 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2799 inflate_blocks_reset(z->state->blocks, z, &c);
2800 Trace((stderr, "inflate: reset\n"));
2810 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2811 return Z_STREAM_ERROR;
2812 if (z->state->blocks != Z_NULL)
2813 inflate_blocks_free(z->state->blocks, z, &c);
2814 ZFREE(z, z->state, sizeof(struct internal_state));
2816 Trace((stderr, "inflate: end\n"));
2821 int inflateInit2(z, w)
2825 /* initialize state */
2827 return Z_STREAM_ERROR;
2828 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2829 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2830 if ((z->state = (struct internal_state FAR *)
2831 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2833 z->state->blocks = Z_NULL;
2835 /* handle undocumented nowrap option (no zlib header or check) */
2836 z->state->nowrap = 0;
2840 z->state->nowrap = 1;
2843 /* set window size */
2844 if (w < 8 || w > 15)
2847 return Z_STREAM_ERROR;
2849 z->state->wbits = (uInt)w;
2851 /* create inflate_blocks state */
2852 if ((z->state->blocks =
2853 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2859 Trace((stderr, "inflate: allocated\n"));
2870 return inflateInit2(z, DEF_WBITS);
2874 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2875 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2884 if (z == Z_NULL || z->next_in == Z_NULL)
2885 return Z_STREAM_ERROR;
2887 while (1) switch (z->state->mode)
2891 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2893 z->state->mode = BAD;
2894 z->msg = "unknown compression method";
2895 z->state->sub.marker = 5; /* can't try inflateSync */
2898 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2900 z->state->mode = BAD;
2901 z->msg = "invalid window size";
2902 z->state->sub.marker = 5; /* can't try inflateSync */
2905 z->state->mode = FLAG;
2908 if ((b = NEXTBYTE) & 0x20)
2910 z->state->mode = BAD;
2911 z->msg = "invalid reserved bit";
2912 z->state->sub.marker = 5; /* can't try inflateSync */
2915 if (((z->state->sub.method << 8) + b) % 31)
2917 z->state->mode = BAD;
2918 z->msg = "incorrect header check";
2919 z->state->sub.marker = 5; /* can't try inflateSync */
2922 Trace((stderr, "inflate: zlib header ok\n"));
2923 z->state->mode = BLOCKS;
2925 r = inflate_blocks(z->state->blocks, z, r);
2926 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2927 r = inflate_packet_flush(z->state->blocks);
2928 if (r == Z_DATA_ERROR)
2930 z->state->mode = BAD;
2931 z->state->sub.marker = 0; /* can try inflateSync */
2934 if (r != Z_STREAM_END)
2937 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2938 if (z->state->nowrap)
2940 z->state->mode = DONE;
2943 z->state->mode = CHECK4;
2946 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2947 z->state->mode = CHECK3;
2950 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2951 z->state->mode = CHECK2;
2954 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2955 z->state->mode = CHECK1;
2958 z->state->sub.check.need += (uLong)NEXTBYTE;
2960 if (z->state->sub.check.was != z->state->sub.check.need)
2962 z->state->mode = BAD;
2963 z->msg = "incorrect data check";
2964 z->state->sub.marker = 5; /* can't try inflateSync */
2967 Trace((stderr, "inflate: zlib check ok\n"));
2968 z->state->mode = DONE;
2970 return Z_STREAM_END;
2972 return Z_DATA_ERROR;
2974 return Z_STREAM_ERROR;
2978 if (f != Z_PACKET_FLUSH)
2980 z->state->mode = BAD;
2981 z->state->sub.marker = 0; /* can try inflateSync */
2982 return Z_DATA_ERROR;
2986 * This subroutine adds the data at next_in/avail_in to the output history
2987 * without performing any output. The output buffer must be "caught up";
2988 * i.e. no pending output (hence s->read equals s->write), and the state must
2989 * be BLOCKS (i.e. we should be willing to see the start of a series of
2990 * BLOCKS). On exit, the output will also be caught up, and the checksum
2991 * will have been updated if need be.
2994 int inflateIncomp(z)
2997 if (z->state->mode != BLOCKS)
2998 return Z_DATA_ERROR;
2999 return inflate_addhistory(z->state->blocks, z);
3006 uInt n; /* number of bytes to look at */
3007 Bytef *p; /* pointer to bytes */
3008 uInt m; /* number of marker bytes found in a row */
3009 uLong r, w; /* temporaries to save total_in and total_out */
3012 if (z == Z_NULL || z->state == Z_NULL)
3013 return Z_STREAM_ERROR;
3014 if (z->state->mode != BAD)
3016 z->state->mode = BAD;
3017 z->state->sub.marker = 0;
3019 if ((n = z->avail_in) == 0)
3022 m = z->state->sub.marker;
3027 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3037 z->total_in += p - z->next_in;
3040 z->state->sub.marker = m;
3042 /* return no joy or set up to restart on a new block */
3044 return Z_DATA_ERROR;
3045 r = z->total_in; w = z->total_out;
3047 z->total_in = r; z->total_out = w;
3048 z->state->mode = BLOCKS;
3056 /* infutil.h -- types and macros common to blocks and codes
3057 * Copyright (C) 1995 Mark Adler
3058 * For conditions of distribution and use, see copyright notice in zlib.h
3061 /* WARNING: this file should *not* be used by applications. It is
3062 part of the implementation of the compression library and is
3063 subject to change. Applications should only use zlib.h.
3066 /* inflate blocks semi-private state */
3067 struct inflate_blocks_state {
3071 TYPE, /* get type bits (3, including end bit) */
3072 LENS, /* get lengths for stored */
3073 STORED, /* processing stored block */
3074 TABLE, /* get table lengths */
3075 BTREE, /* get bit lengths tree for a dynamic block */
3076 DTREE, /* get length, distance trees for a dynamic block */
3077 CODES, /* processing fixed or dynamic block */
3078 DRY, /* output remaining window bytes */
3079 DONEB, /* finished last block, done */
3080 BADB} /* got a data error--stuck here */
3081 mode; /* current inflate_block mode */
3083 /* mode dependent information */
3085 uInt left; /* if STORED, bytes left to copy */
3087 uInt table; /* table lengths (14 bits) */
3088 uInt index; /* index into blens (or border) */
3089 uIntf *blens; /* bit lengths of codes */
3090 uInt bb; /* bit length tree depth */
3091 inflate_huft *tb; /* bit length decoding tree */
3092 int nblens; /* # elements allocated at blens */
3093 } trees; /* if DTREE, decoding info for trees */
3095 inflate_huft *tl, *td; /* trees to free */
3096 inflate_codes_statef
3098 } decode; /* if CODES, current state */
3099 } sub; /* submode */
3100 uInt last; /* true if this block is the last block */
3102 /* mode independent information */
3103 uInt bitk; /* bits in bit buffer */
3104 uLong bitb; /* bit buffer */
3105 Bytef *window; /* sliding window */
3106 Bytef *end; /* one byte after sliding window */
3107 Bytef *read; /* window read pointer */
3108 Bytef *write; /* window write pointer */
3109 check_func checkfn; /* check function */
3110 uLong check; /* check on output */
3115 /* defines for inflate input/output */
3116 /* update pointers and return */
3117 #define UPDBITS {s->bitb=b;s->bitk=k;}
3118 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3119 #define UPDOUT {s->write=q;}
3120 #define UPDATE {UPDBITS UPDIN UPDOUT}
3121 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3122 /* get bytes and bits */
3123 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3124 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3125 #define NEXTBYTE (n--,*p++)
3126 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3127 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3129 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3130 #define LOADOUT {q=s->write;m=WAVAIL;}
3131 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3132 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3133 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3134 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3135 /* load local pointers */
3136 #define LOAD {LOADIN LOADOUT}
3138 /* And'ing with mask[n] masks the lower n bits */
3139 local uInt inflate_mask[] = {
3141 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3142 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3145 /* copy as much as possible from the sliding window to the output area */
3146 local int inflate_flush OF((
3147 inflate_blocks_statef *,
3152 /* inffast.h -- header to use inffast.c
3153 * Copyright (C) 1995 Mark Adler
3154 * For conditions of distribution and use, see copyright notice in zlib.h
3157 /* WARNING: this file should *not* be used by applications. It is
3158 part of the implementation of the compression library and is
3159 subject to change. Applications should only use zlib.h.
3162 local int inflate_fast OF((
3167 inflate_blocks_statef *,
3172 /* infblock.c -- interpret and process block types to last block
3173 * Copyright (C) 1995 Mark Adler
3174 * For conditions of distribution and use, see copyright notice in zlib.h
3177 /* Table for deflate from PKZIP's appnote.txt. */
3178 local uInt border[] = { /* Order of the bit length code lengths */
3179 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3182 Notes beyond the 1.93a appnote.txt:
3184 1. Distance pointers never point before the beginning of the output
3186 2. Distance pointers can point back across blocks, up to 32k away.
3187 3. There is an implied maximum of 7 bits for the bit length table and
3188 15 bits for the actual data.
3189 4. If only one code exists, then it is encoded using one bit. (Zero
3190 would be more efficient, but perhaps a little confusing.) If two
3191 codes exist, they are coded using one bit each (0 and 1).
3192 5. There is no way of sending zero distance codes--a dummy must be
3193 sent if there are none. (History: a pre 2.0 version of PKZIP would
3194 store blocks with no distance codes, but this was discovered to be
3195 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3196 zero distance codes, which is sent as one code of zero bits in
3198 6. There are up to 286 literal/length codes. Code 256 represents the
3199 end-of-block. Note however that the static length tree defines
3200 288 codes just to fill out the Huffman codes. Codes 286 and 287
3201 cannot be used though, since there is no length base or extra bits
3202 defined for them. Similarily, there are up to 30 distance codes.
3203 However, static trees define 32 codes (all 5 bits) to fill out the
3204 Huffman codes, but the last two had better not show up in the data.
3205 7. Unzip can check dynamic Huffman blocks for complete code sets.
3206 The exception is that a single code would not be complete (see #4).
3207 8. The five bits following the block type is really the number of
3208 literal codes sent minus 257.
3209 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3210 (1+6+6). Therefore, to output three times the length, you output
3211 three codes (1+1+1), whereas to output four times the same length,
3212 you only need two codes (1+3). Hmm.
3213 10. In the tree reconstruction algorithm, Code = Code + Increment
3214 only if BitLength(i) is not zero. (Pretty obvious.)
3215 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3216 12. Note: length code 284 can represent 227-258, but length code 285
3217 really is 258. The last length deserves its own, short code
3218 since it gets used a lot in very redundant files. The length
3219 258 is special since 258 - 3 (the min match length) is 255.
3220 13. The literal/length and distance code bit lengths are read as a
3221 single stream of lengths. It is possible (and advantageous) for
3222 a repeat code (16, 17, or 18) to go across the boundary between
3223 the two sets of lengths.
3227 local void inflate_blocks_reset(s, z, c)
3228 inflate_blocks_statef *s;
3232 if (s->checkfn != Z_NULL)
3234 if (s->mode == BTREE || s->mode == DTREE)
3235 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3236 if (s->mode == CODES)
3238 inflate_codes_free(s->sub.decode.codes, z);
3239 inflate_trees_free(s->sub.decode.td, z);
3240 inflate_trees_free(s->sub.decode.tl, z);
3245 s->read = s->write = s->window;
3246 if (s->checkfn != Z_NULL)
3247 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3248 Trace((stderr, "inflate: blocks reset\n"));
3252 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
3257 inflate_blocks_statef *s;
3259 if ((s = (inflate_blocks_statef *)ZALLOC
3260 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3262 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3264 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3267 s->end = s->window + w;
3270 Trace((stderr, "inflate: blocks allocated\n"));
3271 inflate_blocks_reset(s, z, &s->check);
3276 local int inflate_blocks(s, z, r)
3277 inflate_blocks_statef *s;
3281 uInt t; /* temporary storage */
3282 uLong b; /* bit buffer */
3283 uInt k; /* bits in bit buffer */
3284 Bytef *p; /* input data pointer */
3285 uInt n; /* bytes available there */
3286 Bytef *q; /* output window write pointer */
3287 uInt m; /* bytes to end of window or read pointer */
3289 /* copy input/output information to locals (UPDATE macro restores) */
3292 /* process input based on current state */
3293 while (1) switch (s->mode)
3301 case 0: /* stored */
3302 Trace((stderr, "inflate: stored block%s\n",
3303 s->last ? " (last)" : ""));
3305 t = k & 7; /* go to byte boundary */
3307 s->mode = LENS; /* get length of stored block */
3310 Trace((stderr, "inflate: fixed codes block%s\n",
3311 s->last ? " (last)" : ""));
3314 inflate_huft *tl, *td;
3316 inflate_trees_fixed(&bl, &bd, &tl, &td);
3317 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3318 if (s->sub.decode.codes == Z_NULL)
3323 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3324 s->sub.decode.td = Z_NULL;
3329 case 2: /* dynamic */
3330 Trace((stderr, "inflate: dynamic codes block%s\n",
3331 s->last ? " (last)" : ""));
3335 case 3: /* illegal */
3338 z->msg = "invalid block type";
3345 if (((~b) >> 16) != (b & 0xffff))
3348 z->msg = "invalid stored block lengths";
3352 s->sub.left = (uInt)b & 0xffff;
3353 b = k = 0; /* dump bits */
3354 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3355 s->mode = s->sub.left ? STORED : TYPE;
3367 if ((s->sub.left -= t) != 0)
3369 Tracev((stderr, "inflate: stored end, %lu total out\n",
3370 z->total_out + (q >= s->read ? q - s->read :
3371 (s->end - s->read) + (q - s->window))));
3372 s->mode = s->last ? DRY : TYPE;
3376 s->sub.trees.table = t = (uInt)b & 0x3fff;
3377 #ifndef PKZIP_BUG_WORKAROUND
3378 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3381 z->msg = "too many length or distance symbols";
3386 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3389 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3394 s->sub.trees.nblens = t;
3396 s->sub.trees.index = 0;
3397 Tracev((stderr, "inflate: table sizes ok\n"));
3400 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3403 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3406 while (s->sub.trees.index < 19)
3407 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3408 s->sub.trees.bb = 7;
3409 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3410 &s->sub.trees.tb, z);
3414 if (r == Z_DATA_ERROR)
3418 s->sub.trees.index = 0;
3419 Tracev((stderr, "inflate: bits tree ok\n"));
3422 while (t = s->sub.trees.table,
3423 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3428 t = s->sub.trees.bb;
3430 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3431 t = h->word.what.Bits;
3436 s->sub.trees.blens[s->sub.trees.index++] = c;
3438 else /* c == 16..18 */
3440 i = c == 18 ? 7 : c - 14;
3441 j = c == 18 ? 11 : 3;
3444 j += (uInt)b & inflate_mask[i];
3446 i = s->sub.trees.index;
3447 t = s->sub.trees.table;
3448 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3452 z->msg = "invalid bit length repeat";
3456 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3458 s->sub.trees.blens[i++] = c;
3460 s->sub.trees.index = i;
3463 inflate_trees_free(s->sub.trees.tb, z);
3464 s->sub.trees.tb = Z_NULL;
3467 inflate_huft *tl, *td;
3468 inflate_codes_statef *c;
3470 bl = 9; /* must be <= 9 for lookahead assumptions */
3471 bd = 6; /* must be <= 9 for lookahead assumptions */
3472 t = s->sub.trees.table;
3473 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3474 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3477 if (t == (uInt)Z_DATA_ERROR)
3482 Tracev((stderr, "inflate: trees ok\n"));
3483 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3485 inflate_trees_free(td, z);
3486 inflate_trees_free(tl, z);
3490 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3491 s->sub.decode.codes = c;
3492 s->sub.decode.tl = tl;
3493 s->sub.decode.td = td;
3498 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3499 return inflate_flush(s, z, r);
3501 inflate_codes_free(s->sub.decode.codes, z);
3502 inflate_trees_free(s->sub.decode.td, z);
3503 inflate_trees_free(s->sub.decode.tl, z);
3505 Tracev((stderr, "inflate: codes end, %lu total out\n",
3506 z->total_out + (q >= s->read ? q - s->read :
3507 (s->end - s->read) + (q - s->window))));
3513 if (k > 7) /* return unused byte, if any */
3515 Assert(k < 16, "inflate_codes grabbed too many bytes")
3518 p--; /* can always return one */
3523 if (s->read != s->write)
3539 local int inflate_blocks_free(s, z, c)
3540 inflate_blocks_statef *s;
3544 inflate_blocks_reset(s, z, c);
3545 ZFREE(z, s->window, s->end - s->window);
3546 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3547 Trace((stderr, "inflate: blocks freed\n"));
3552 * This subroutine adds the data at next_in/avail_in to the output history
3553 * without performing any output. The output buffer must be "caught up";
3554 * i.e. no pending output (hence s->read equals s->write), and the state must
3555 * be BLOCKS (i.e. we should be willing to see the start of a series of
3556 * BLOCKS). On exit, the output will also be caught up, and the checksum
3557 * will have been updated if need be.
3559 local int inflate_addhistory(s, z)
3560 inflate_blocks_statef *s;
3563 uLong b; /* bit buffer */ /* NOT USED HERE */
3564 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3565 uInt t; /* temporary storage */
3566 Bytef *p; /* input data pointer */
3567 uInt n; /* bytes available there */
3568 Bytef *q; /* output window write pointer */
3569 uInt m; /* bytes to end of window or read pointer */
3571 if (s->read != s->write)
3572 return Z_STREAM_ERROR;
3573 if (s->mode != TYPE)
3574 return Z_DATA_ERROR;
3576 /* we're ready to rock */
3578 /* while there is input ready, copy to output buffer, moving
3579 * pointers as needed.
3582 t = n; /* how many to do */
3583 /* is there room until end of buffer? */
3585 /* update check information */
3586 if (s->checkfn != Z_NULL)
3587 s->check = (*s->checkfn)(s->check, q, t);
3593 s->read = q; /* drag read pointer forward */
3594 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
3596 s->read = q = s->window;
3606 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3607 * a `stored' block type value but not the (zero) length bytes.
3609 local int inflate_packet_flush(s)
3610 inflate_blocks_statef *s;
3612 if (s->mode != LENS)
3613 return Z_DATA_ERROR;
3620 /* inftrees.c -- generate Huffman trees for efficient decoding
3621 * Copyright (C) 1995 Mark Adler
3622 * For conditions of distribution and use, see copyright notice in zlib.h
3625 /* simplify the use of the inflate_huft type with some defines */
3626 #define base more.Base
3627 #define next more.Next
3628 #define exop word.what.Exop
3629 #define bits word.what.Bits
3632 local int huft_build OF((
3633 uIntf *, /* code lengths in bits */
3634 uInt, /* number of codes */
3635 uInt, /* number of "simple" codes */
3636 uIntf *, /* list of base values for non-simple codes */
3637 uIntf *, /* list of extra bits for non-simple codes */
3638 inflate_huft * FAR*,/* result: starting table */
3639 uIntf *, /* maximum lookup bits (returns actual) */
3640 z_stream *)); /* for zalloc function */
3642 local voidpf falloc OF((
3643 voidpf, /* opaque pointer (not used) */
3644 uInt, /* number of items */
3645 uInt)); /* size of item */
3647 local void ffree OF((
3648 voidpf q, /* opaque pointer (not used) */
3649 voidpf p, /* what to free (not used) */
3650 uInt n)); /* number of bytes (not used) */
3652 /* Tables for deflate from PKZIP's appnote.txt. */
3653 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3654 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3655 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3656 /* actually lengths - 2; also see note #13 above about 258 */
3657 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3658 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3659 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3660 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3661 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3662 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3663 8193, 12289, 16385, 24577};
3664 local uInt cpdext[] = { /* Extra bits for distance codes */
3665 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3666 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3670 Huffman code decoding is performed using a multi-level table lookup.
3671 The fastest way to decode is to simply build a lookup table whose
3672 size is determined by the longest code. However, the time it takes
3673 to build this table can also be a factor if the data being decoded
3674 is not very long. The most common codes are necessarily the
3675 shortest codes, so those codes dominate the decoding time, and hence
3676 the speed. The idea is you can have a shorter table that decodes the
3677 shorter, more probable codes, and then point to subsidiary tables for
3678 the longer codes. The time it costs to decode the longer codes is
3679 then traded against the time it takes to make longer tables.
3681 This results of this trade are in the variables lbits and dbits
3682 below. lbits is the number of bits the first level table for literal/
3683 length codes can decode in one step, and dbits is the same thing for
3684 the distance codes. Subsequent tables are also less than or equal to
3685 those sizes. These values may be adjusted either when all of the
3686 codes are shorter than that, in which case the longest code length in
3687 bits is used, or when the shortest code is *longer* than the requested
3688 table size, in which case the length of the shortest code in bits is
3691 There are two different values for the two tables, since they code a
3692 different number of possibilities each. The literal/length table
3693 codes 286 possible values, or in a flat code, a little over eight
3694 bits. The distance table codes 30 possible values, or a little less
3695 than five bits, flat. The optimum values for speed end up being
3696 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3697 The optimum values may differ though from machine to machine, and
3698 possibly even between compilers. Your mileage may vary.
3702 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3703 #define BMAX 15 /* maximum bit length of any code */
3704 #define N_MAX 288 /* maximum number of codes in any set */
3710 local int huft_build(b, n, s, d, e, t, m, zs)
3711 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3712 uInt n; /* number of codes (assumed <= N_MAX) */
3713 uInt s; /* number of simple-valued codes (0..s-1) */
3714 uIntf *d; /* list of base values for non-simple codes */
3715 uIntf *e; /* list of extra bits for non-simple codes */
3716 inflate_huft * FAR *t; /* result: starting table */
3717 uIntf *m; /* maximum lookup bits, returns actual */
3718 z_stream *zs; /* for zalloc function */
3719 /* Given a list of code lengths and a maximum table size, make a set of
3720 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3721 if the given code set is incomplete (the tables are still built in this
3722 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3723 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3726 uInt a; /* counter for codes of length k */
3727 uInt c[BMAX+1]; /* bit length count table */
3728 uInt f; /* i repeats in table every f entries */
3729 int g; /* maximum code length */
3730 int h; /* table level */
3731 register uInt i; /* counter, current code */
3732 register uInt j; /* counter */
3733 register int k; /* number of bits in current code */
3734 int l; /* bits per table (returned in m) */
3735 register uIntf *p; /* pointer into c[], b[], or v[] */
3736 inflate_huft *q; /* points to current table */
3737 struct inflate_huft_s r; /* table entry for structure assignment */
3738 inflate_huft *u[BMAX]; /* table stack */
3739 uInt v[N_MAX]; /* values in order of bit length */
3740 register int w; /* bits before this table == (l * h) */
3741 uInt x[BMAX+1]; /* bit offsets, then code stack */
3742 uIntf *xp; /* pointer into x */
3743 int y; /* number of dummy codes added */
3744 uInt z; /* number of entries in current table */
3747 /* Generate counts for each bit length */
3749 #define C0 *p++ = 0;
3750 #define C2 C0 C0 C0 C0
3751 #define C4 C2 C2 C2 C2
3752 C4 /* clear c[]--assume BMAX+1 is 16 */
3755 c[*p++]++; /* assume all entries <= BMAX */
3757 if (c[0] == n) /* null input--all zero length codes */
3759 *t = (inflate_huft *)Z_NULL;
3765 /* Find minimum and maximum length, bound *m by those */
3767 for (j = 1; j <= BMAX; j++)
3770 k = j; /* minimum code length */
3773 for (i = BMAX; i; i--)
3776 g = i; /* maximum code length */
3782 /* Adjust last length count to fill out codes, if needed */
3783 for (y = 1 << j; j < i; j++, y <<= 1)
3784 if ((y -= c[j]) < 0)
3785 return Z_DATA_ERROR;
3786 if ((y -= c[i]) < 0)
3787 return Z_DATA_ERROR;
3791 /* Generate starting offsets into the value table for each length */
3793 p = c + 1; xp = x + 2;
3794 while (--i) { /* note that i == g from above */
3795 *xp++ = (j += *p++);
3799 /* Make a table of values in order of bit lengths */
3802 if ((j = *p++) != 0)
3807 /* Generate the Huffman codes and for each, make the table entries */
3808 x[0] = i = 0; /* first Huffman code is zero */
3809 p = v; /* grab values in bit order */
3810 h = -1; /* no tables yet--level -1 */
3811 w = -l; /* bits decoded == (l * h) */
3812 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3813 q = (inflate_huft *)Z_NULL; /* ditto */
3816 /* go through the bit lengths (k already is bits in shortest code) */
3822 /* here i is the Huffman code of length k bits for value *p */
3823 /* make tables up to required level */
3827 w += l; /* previous table always l bits */
3829 /* compute minimum size table less than or equal to l bits */
3830 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3831 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3832 { /* too few codes for k-w bit table */
3833 f -= a + 1; /* deduct codes from patterns left */
3836 while (++j < z) /* try smaller tables up to z bits */
3838 if ((f <<= 1) <= *++xp)
3839 break; /* enough codes to use up j bits */
3840 f -= *xp; /* else deduct codes from patterns */
3843 z = 1 << j; /* table entries for j-bit table */
3845 /* allocate and link in new table */
3846 if ((q = (inflate_huft *)ZALLOC
3847 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3850 inflate_trees_free(u[0], zs);
3851 return Z_MEM_ERROR; /* not enough memory */
3853 q->word.Nalloc = z + 1;
3855 inflate_hufts += z + 1;
3857 *t = q + 1; /* link to list for huft_free() */
3858 *(t = &(q->next)) = Z_NULL;
3859 u[h] = ++q; /* table starts after link */
3861 /* connect to last table, if there is one */
3864 x[h] = i; /* save pattern for backing up */
3865 r.bits = (Byte)l; /* bits to dump before this table */
3866 r.exop = (Byte)j; /* bits in this table */
3867 r.next = q; /* pointer to this table */
3868 j = i >> (w - l); /* (get around Turbo C bug) */
3869 u[h-1][j] = r; /* connect to last table */
3873 /* set up table entry in r */
3874 r.bits = (Byte)(k - w);
3876 r.exop = 128 + 64; /* out of values--invalid code */
3879 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3880 r.base = *p++; /* simple code is just the value */
3884 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3885 r.base = d[*p++ - s];
3888 /* fill code-like entries with r */
3890 for (j = i >> w; j < z; j += f)
3893 /* backwards increment the k-bit code i */
3894 for (j = 1 << (k - 1); i & j; j >>= 1)
3898 /* backup over finished tables */
3899 while ((i & ((1 << w) - 1)) != x[h])
3901 h--; /* don't need to update q */
3908 /* Return Z_BUF_ERROR if we were given an incomplete table */
3909 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3913 local int inflate_trees_bits(c, bb, tb, z)
3914 uIntf *c; /* 19 code lengths */
3915 uIntf *bb; /* bits tree desired/actual depth */
3916 inflate_huft * FAR *tb; /* bits tree result */
3917 z_stream *z; /* for zfree function */
3921 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3922 if (r == Z_DATA_ERROR)
3923 z->msg = "oversubscribed dynamic bit lengths tree";
3924 else if (r == Z_BUF_ERROR)
3926 inflate_trees_free(*tb, z);
3927 z->msg = "incomplete dynamic bit lengths tree";
3934 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3935 uInt nl; /* number of literal/length codes */
3936 uInt nd; /* number of distance codes */
3937 uIntf *c; /* that many (total) code lengths */
3938 uIntf *bl; /* literal desired/actual bit depth */
3939 uIntf *bd; /* distance desired/actual bit depth */
3940 inflate_huft * FAR *tl; /* literal/length tree result */
3941 inflate_huft * FAR *td; /* distance tree result */
3942 z_stream *z; /* for zfree function */
3946 /* build literal/length tree */
3947 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3949 if (r == Z_DATA_ERROR)
3950 z->msg = "oversubscribed literal/length tree";
3951 else if (r == Z_BUF_ERROR)
3953 inflate_trees_free(*tl, z);
3954 z->msg = "incomplete literal/length tree";
3960 /* build distance tree */
3961 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3963 if (r == Z_DATA_ERROR)
3964 z->msg = "oversubscribed literal/length tree";
3965 else if (r == Z_BUF_ERROR) {
3966 #ifdef PKZIP_BUG_WORKAROUND
3970 inflate_trees_free(*td, z);
3971 z->msg = "incomplete literal/length tree";
3974 inflate_trees_free(*tl, z);
3984 /* build fixed tables only once--keep them here */
3985 local int fixed_lock = 0;
3986 local int fixed_built = 0;
3987 #define FIXEDH 530 /* number of hufts used by fixed tables */
3988 local uInt fixed_left = FIXEDH;
3989 local inflate_huft fixed_mem[FIXEDH];
3990 local uInt fixed_bl;
3991 local uInt fixed_bd;
3992 local inflate_huft *fixed_tl;
3993 local inflate_huft *fixed_td;
3996 local voidpf falloc(q, n, s)
3997 voidpf q; /* opaque pointer (not used) */
3998 uInt n; /* number of items */
3999 uInt s; /* size of item */
4001 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
4002 "inflate_trees falloc overflow");
4003 if (q) s++; /* to make some compilers happy */
4005 return (voidpf)(fixed_mem + fixed_left);
4009 local void ffree(q, p, n)
4014 Assert(0, "inflate_trees ffree called!");
4015 if (q) q = p; /* to make some compilers happy */
4019 local int inflate_trees_fixed(bl, bd, tl, td)
4020 uIntf *bl; /* literal desired/actual bit depth */
4021 uIntf *bd; /* distance desired/actual bit depth */
4022 inflate_huft * FAR *tl; /* literal/length tree result */
4023 inflate_huft * FAR *td; /* distance tree result */
4025 /* build fixed tables if not built already--lock out other instances */
4026 while (++fixed_lock > 1)
4030 int k; /* temporary variable */
4031 unsigned c[288]; /* length list for huft_build */
4032 z_stream z; /* for falloc function */
4034 /* set up fake z_stream for memory routines */
4040 for (k = 0; k < 144; k++)
4042 for (; k < 256; k++)
4044 for (; k < 280; k++)
4046 for (; k < 288; k++)
4049 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4051 /* distance table */
4052 for (k = 0; k < 30; k++)
4055 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4069 local int inflate_trees_free(t, z)
4070 inflate_huft *t; /* table to free */
4071 z_stream *z; /* for zfree function */
4072 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4073 list of the tables it made, with the links in a dummy first entry of
4076 register inflate_huft *p, *q;
4078 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4083 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4090 /* infcodes.c -- process literals and length/distance pairs
4091 * Copyright (C) 1995 Mark Adler
4092 * For conditions of distribution and use, see copyright notice in zlib.h
4095 /* simplify the use of the inflate_huft type with some defines */
4096 #define base more.Base
4097 #define next more.Next
4098 #define exop word.what.Exop
4099 #define bits word.what.Bits
4101 /* inflate codes private state */
4102 struct inflate_codes_state {
4105 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4106 START, /* x: set up for LEN */
4107 LEN, /* i: get length/literal/eob next */
4108 LENEXT, /* i: getting length extra (have base) */
4109 DIST, /* i: get distance next */
4110 DISTEXT, /* i: getting distance extra */
4111 COPY, /* o: copying bytes in window, waiting for space */
4112 LIT, /* o: got literal, waiting for output space */
4113 WASH, /* o: got eob, possibly still output waiting */
4114 END, /* x: got eob and all data flushed */
4115 BADCODE} /* x: got error */
4116 mode; /* current inflate_codes mode */
4118 /* mode dependent information */
4122 inflate_huft *tree; /* pointer into tree */
4123 uInt need; /* bits needed */
4124 } code; /* if LEN or DIST, where in tree */
4125 uInt lit; /* if LIT, literal */
4127 uInt get; /* bits to get for extra */
4128 uInt dist; /* distance back to copy from */
4129 } copy; /* if EXT or COPY, where and how much */
4130 } sub; /* submode */
4132 /* mode independent information */
4133 Byte lbits; /* ltree bits decoded per branch */
4134 Byte dbits; /* dtree bits decoder per branch */
4135 inflate_huft *ltree; /* literal/length/eob tree */
4136 inflate_huft *dtree; /* distance tree */
4141 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4143 inflate_huft *tl, *td;
4146 inflate_codes_statef *c;
4148 if ((c = (inflate_codes_statef *)
4149 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4152 c->lbits = (Byte)bl;
4153 c->dbits = (Byte)bd;
4156 Tracev((stderr, "inflate: codes new\n"));
4162 local int inflate_codes(s, z, r)
4163 inflate_blocks_statef *s;
4167 uInt j; /* temporary storage */
4168 inflate_huft *t; /* temporary pointer */
4169 uInt e; /* extra bits or operation */
4170 uLong b; /* bit buffer */
4171 uInt k; /* bits in bit buffer */
4172 Bytef *p; /* input data pointer */
4173 uInt n; /* bytes available there */
4174 Bytef *q; /* output window write pointer */
4175 uInt m; /* bytes to end of window or read pointer */
4176 Bytef *f; /* pointer to copy strings from */
4177 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4179 /* copy input/output information to locals (UPDATE macro restores) */
4182 /* process input and output based on current state */
4183 while (1) switch (c->mode)
4184 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4185 case START: /* x: set up for LEN */
4187 if (m >= 258 && n >= 10)
4190 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4194 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4199 c->sub.code.need = c->lbits;
4200 c->sub.code.tree = c->ltree;
4202 case LEN: /* i: get length/literal/eob next */
4203 j = c->sub.code.need;
4205 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4207 e = (uInt)(t->exop);
4208 if (e == 0) /* literal */
4210 c->sub.lit = t->base;
4211 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4212 "inflate: literal '%c'\n" :
4213 "inflate: literal 0x%02x\n", t->base));
4217 if (e & 16) /* length */
4219 c->sub.copy.get = e & 15;
4224 if ((e & 64) == 0) /* next table */
4226 c->sub.code.need = e;
4227 c->sub.code.tree = t->next;
4230 if (e & 32) /* end of block */
4232 Tracevv((stderr, "inflate: end of block\n"));
4236 c->mode = BADCODE; /* invalid code */
4237 z->msg = "invalid literal/length code";
4240 case LENEXT: /* i: getting length extra (have base) */
4241 j = c->sub.copy.get;
4243 c->len += (uInt)b & inflate_mask[j];
4245 c->sub.code.need = c->dbits;
4246 c->sub.code.tree = c->dtree;
4247 Tracevv((stderr, "inflate: length %u\n", c->len));
4249 case DIST: /* i: get distance next */
4250 j = c->sub.code.need;
4252 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4254 e = (uInt)(t->exop);
4255 if (e & 16) /* distance */
4257 c->sub.copy.get = e & 15;
4258 c->sub.copy.dist = t->base;
4262 if ((e & 64) == 0) /* next table */
4264 c->sub.code.need = e;
4265 c->sub.code.tree = t->next;
4268 c->mode = BADCODE; /* invalid code */
4269 z->msg = "invalid distance code";
4272 case DISTEXT: /* i: getting distance extra */
4273 j = c->sub.copy.get;
4275 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4277 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4279 case COPY: /* o: copying bytes in window, waiting for space */
4280 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4281 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4282 s->end - (c->sub.copy.dist - (q - s->window)) :
4283 q - c->sub.copy.dist;
4285 f = q - c->sub.copy.dist;
4286 if ((uInt)(q - s->window) < c->sub.copy.dist)
4287 f = s->end - (c->sub.copy.dist - (q - s->window));
4299 case LIT: /* o: got literal, waiting for output space */
4304 case WASH: /* o: got eob, possibly more output */
4306 if (s->read != s->write)
4312 case BADCODE: /* x: got error */
4322 local void inflate_codes_free(c, z)
4323 inflate_codes_statef *c;
4326 ZFREE(z, c, sizeof(struct inflate_codes_state));
4327 Tracev((stderr, "inflate: codes free\n"));
4331 /* inflate_util.c -- data and routines common to blocks and codes
4332 * Copyright (C) 1995 Mark Adler
4333 * For conditions of distribution and use, see copyright notice in zlib.h
4336 /* copy as much as possible from the sliding window to the output area */
4337 local int inflate_flush(s, z, r)
4338 inflate_blocks_statef *s;
4345 /* local copies of source and destination pointers */
4349 /* compute number of bytes to copy as far as end of window */
4350 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4351 if (n > z->avail_out) n = z->avail_out;
4352 if (n && r == Z_BUF_ERROR) r = Z_OK;
4354 /* update counters */
4358 /* update check information */
4359 if (s->checkfn != Z_NULL)
4360 s->check = (*s->checkfn)(s->check, q, n);
4362 /* copy as far as end of window */
4369 /* see if more to copy at beginning of window */
4374 if (s->write == s->end)
4375 s->write = s->window;
4377 /* compute bytes to copy */
4378 n = (uInt)(s->write - q);
4379 if (n > z->avail_out) n = z->avail_out;
4380 if (n && r == Z_BUF_ERROR) r = Z_OK;
4382 /* update counters */
4386 /* update check information */
4387 if (s->checkfn != Z_NULL)
4388 s->check = (*s->checkfn)(s->check, q, n);
4398 /* update pointers */
4408 /* inffast.c -- process literals and length/distance pairs fast
4409 * Copyright (C) 1995 Mark Adler
4410 * For conditions of distribution and use, see copyright notice in zlib.h
4413 /* simplify the use of the inflate_huft type with some defines */
4414 #define base more.Base
4415 #define next more.Next
4416 #define exop word.what.Exop
4417 #define bits word.what.Bits
4419 /* macros for bit input with no checking and for returning unused bytes */
4420 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4421 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4423 /* Called with number of bytes left to write in window at least 258
4424 (the maximum string length) and number of input bytes available
4425 at least ten. The ten bytes are six bytes for the longest length/
4426 distance pair plus four bytes for overloading the bit buffer. */
4428 local int inflate_fast(bl, bd, tl, td, s, z)
4430 inflate_huft *tl, *td;
4431 inflate_blocks_statef *s;
4434 inflate_huft *t; /* temporary pointer */
4435 uInt e; /* extra bits or operation */
4436 uLong b; /* bit buffer */
4437 uInt k; /* bits in bit buffer */
4438 Bytef *p; /* input data pointer */
4439 uInt n; /* bytes available there */
4440 Bytef *q; /* output window write pointer */
4441 uInt m; /* bytes to end of window or read pointer */
4442 uInt ml; /* mask for literal/length tree */
4443 uInt md; /* mask for distance tree */
4444 uInt c; /* bytes to copy */
4445 uInt d; /* distance back to copy from */
4446 Bytef *r; /* copy source pointer */
4448 /* load input, output, bit values */
4451 /* initialize masks */
4452 ml = inflate_mask[bl];
4453 md = inflate_mask[bd];
4455 /* do until not enough input or output space for fast loop */
4456 do { /* assume called with m >= 258 && n >= 10 */
4457 /* get literal/length code */
4458 GRABBITS(20) /* max bits for literal/length code */
4459 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4462 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4463 "inflate: * literal '%c'\n" :
4464 "inflate: * literal 0x%02x\n", t->base));
4465 *q++ = (Byte)t->base;
4473 /* get extra bits for length */
4475 c = t->base + ((uInt)b & inflate_mask[e]);
4477 Tracevv((stderr, "inflate: * length %u\n", c));
4479 /* decode distance base of block to copy */
4480 GRABBITS(15); /* max bits for distance code */
4481 e = (t = td + ((uInt)b & md))->exop;
4486 /* get extra bits to add to distance base */
4488 GRABBITS(e) /* get extra bits (up to 13) */
4489 d = t->base + ((uInt)b & inflate_mask[e]);
4491 Tracevv((stderr, "inflate: * distance %u\n", d));
4495 if ((uInt)(q - s->window) >= d) /* offset before dest */
4498 *q++ = *r++; c--; /* minimum count is three, */
4499 *q++ = *r++; c--; /* so unroll loop a little */
4501 else /* else offset after destination */
4503 e = d - (q - s->window); /* bytes from offset to end */
4504 r = s->end - e; /* pointer to offset */
4505 if (c > e) /* if source crosses, */
4507 c -= e; /* copy to end of window */
4511 r = s->window; /* copy rest from start of window */
4514 do { /* copy all or what's left */
4519 else if ((e & 64) == 0)
4520 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4523 z->msg = "invalid distance code";
4526 return Z_DATA_ERROR;
4533 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4536 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4537 "inflate: * literal '%c'\n" :
4538 "inflate: * literal 0x%02x\n", t->base));
4539 *q++ = (Byte)t->base;
4546 Tracevv((stderr, "inflate: * end of block\n"));
4549 return Z_STREAM_END;
4553 z->msg = "invalid literal/length code";
4556 return Z_DATA_ERROR;
4559 } while (m >= 258 && n >= 10);
4561 /* not enough input or output--restore pointers and return */
4569 /* zutil.c -- target dependent utility functions for the compression library
4570 * Copyright (C) 1995 Jean-loup Gailly.
4571 * For conditions of distribution and use, see copyright notice in zlib.h
4574 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
4576 char *zlib_version = ZLIB_VERSION;
4578 char *z_errmsg[] = {
4579 "stream end", /* Z_STREAM_END 1 */
4581 "file error", /* Z_ERRNO (-1) */
4582 "stream error", /* Z_STREAM_ERROR (-2) */
4583 "data error", /* Z_DATA_ERROR (-3) */
4584 "insufficient memory", /* Z_MEM_ERROR (-4) */
4585 "buffer error", /* Z_BUF_ERROR (-5) */
4590 /* adler32.c -- compute the Adler-32 checksum of a data stream
4591 * Copyright (C) 1995 Mark Adler
4592 * For conditions of distribution and use, see copyright notice in zlib.h
4595 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
4597 #define BASE 65521L /* largest prime smaller than 65536 */
4599 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4601 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4602 #define DO2(buf) DO1(buf); DO1(buf);
4603 #define DO4(buf) DO2(buf); DO2(buf);
4604 #define DO8(buf) DO4(buf); DO4(buf);
4605 #define DO16(buf) DO8(buf); DO8(buf);
4607 /* ========================================================================= */
4608 uLong adler32(adler, buf, len)
4613 unsigned long s1 = adler & 0xffff;
4614 unsigned long s2 = (adler >> 16) & 0xffff;
4617 if (buf == Z_NULL) return 1L;
4620 k = len < NMAX ? len : NMAX;
4632 return (s2 << 16) | s1;