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 1.2 1996/04/04 02:43:28 paulus Exp $
19 /* zutil.h -- internal interface and configuration of the compression library
20 * Copyright (C) 1995 Jean-loup Gailly.
21 * For conditions of distribution and use, see copyright notice in zlib.h
24 /* WARNING: this file should *not* be used by applications. It is
25 part of the implementation of the compression library and is
26 subject to change. Applications should only use zlib.h.
29 /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */
42 /* compile with -Dlocal if your debugger can't find static symbols */
46 typedef unsigned char uch;
48 typedef unsigned short ush;
50 typedef unsigned long ulg;
52 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
54 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
55 /* To be used only when the state is known to be valid */
58 #define NULL ((void *) 0)
61 /* common constants */
66 # define DEF_WBITS MAX_WBITS
68 /* default windowBits for decompression. MAX_WBITS is for compression only */
70 #if MAX_MEM_LEVEL >= 8
71 # define DEF_MEM_LEVEL 8
73 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
75 /* default memLevel */
77 #define STORED_BLOCK 0
78 #define STATIC_TREES 1
80 /* The three kinds of block type */
84 /* The minimum and maximum match lengths */
88 #if defined(KERNEL) || defined(_KERNEL)
89 # define zmemcpy(d, s, n) bcopy((s), (d), (n))
90 # define zmemzero bzero
92 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
96 # define zmemcpy memcpy
97 # define zmemzero(dest, len) memset(dest, 0, len)
99 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
100 extern void zmemzero OF((Bytef* dest, uInt len));
104 /* Diagnostic functions */
110 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
111 # define Trace(x) fprintf x
112 # define Tracev(x) {if (verbose) fprintf x ;}
113 # define Tracevv(x) {if (verbose>1) fprintf x ;}
114 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
115 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
117 # define Assert(cond,msg)
122 # define Tracecv(c,x)
126 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
128 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
129 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
131 #define ZALLOC(strm, items, size) \
132 (*((strm)->zalloc))((strm)->opaque, (items), (size))
133 #define ZFREE(strm, addr, size) \
134 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
135 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
137 /* deflate.h -- internal compression state
138 * Copyright (C) 1995 Jean-loup Gailly
139 * For conditions of distribution and use, see copyright notice in zlib.h
142 /* WARNING: this file should *not* be used by applications. It is
143 part of the implementation of the compression library and is
144 subject to change. Applications should only use zlib.h.
149 /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */
151 /* ===========================================================================
152 * Internal compression state.
160 #define LENGTH_CODES 29
161 /* number of length codes, not counting the special END_BLOCK code */
164 /* number of literal bytes 0..255 */
166 #define L_CODES (LITERALS+1+LENGTH_CODES)
167 /* number of Literal or Length codes, including the END_BLOCK code */
170 /* number of distance codes */
173 /* number of codes used to transfer the bit lengths */
175 #define HEAP_SIZE (2*L_CODES+1)
176 /* maximum heap size */
179 /* All codes must not exceed MAX_BITS bits */
181 #define INIT_STATE 42
182 #define BUSY_STATE 113
183 #define FLUSH_STATE 124
184 #define FINISH_STATE 666
188 /* Data structure describing a single value and its code string. */
189 typedef struct ct_data_s {
191 ush freq; /* frequency count */
192 ush code; /* bit string */
195 ush dad; /* father node in Huffman tree */
196 ush len; /* length of bit string */
205 typedef struct static_tree_desc_s static_tree_desc;
207 typedef struct tree_desc_s {
208 ct_data *dyn_tree; /* the dynamic tree */
209 int max_code; /* largest code with non zero frequency */
210 static_tree_desc *stat_desc; /* the corresponding static tree */
214 typedef Pos FAR Posf;
215 typedef unsigned IPos;
217 /* A Pos is an index in the character window. We use short instead of int to
218 * save space in the various tables. IPos is used only for parameter passing.
221 typedef struct deflate_state {
222 z_stream *strm; /* pointer back to this zlib stream */
223 int status; /* as the name implies */
224 Bytef *pending_buf; /* output still pending */
225 Bytef *pending_out; /* next pending byte to output to the stream */
226 int pending; /* nb of bytes in the pending buffer */
227 uLong adler; /* adler32 of uncompressed data */
228 int noheader; /* suppress zlib header and adler32 */
229 Byte data_type; /* UNKNOWN, BINARY or ASCII */
230 Byte method; /* STORED (for zip only) or DEFLATED */
231 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */
233 /* used by deflate.c: */
235 uInt w_size; /* LZ77 window size (32K by default) */
236 uInt w_bits; /* log2(w_size) (8..16) */
237 uInt w_mask; /* w_size - 1 */
240 /* Sliding window. Input bytes are read into the second half of the window,
241 * and move to the first half later to keep a dictionary of at least wSize
242 * bytes. With this organization, matches are limited to a distance of
243 * wSize-MAX_MATCH bytes, but this ensures that IO is always
244 * performed with a length multiple of the block size. Also, it limits
245 * the window size to 64K, which is quite useful on MSDOS.
246 * To do: use the user input buffer as sliding window.
250 /* Actual size of window: 2*wSize, except when the user input buffer
251 * is directly used as sliding window.
255 /* Link to older string with same hash index. To limit the size of this
256 * array to 64K, this link is maintained only for the last 32K strings.
257 * An index in this array is thus a window index modulo 32K.
260 Posf *head; /* Heads of the hash chains or NIL. */
262 uInt ins_h; /* hash index of string to be inserted */
263 uInt hash_size; /* number of elements in hash table */
264 uInt hash_bits; /* log2(hash_size) */
265 uInt hash_mask; /* hash_size-1 */
268 /* Number of bits by which ins_h must be shifted at each input
269 * step. It must be such that after MIN_MATCH steps, the oldest
270 * byte no longer takes part in the hash key, that is:
271 * hash_shift * MIN_MATCH >= hash_bits
275 /* Window position at the beginning of the current output block. Gets
276 * negative when the window is moved backwards.
279 uInt match_length; /* length of best match */
280 IPos prev_match; /* previous match */
281 int match_available; /* set if previous match exists */
282 uInt strstart; /* start of string to insert */
283 uInt match_start; /* start of matching string */
284 uInt lookahead; /* number of valid bytes ahead in window */
287 /* Length of the best match at previous step. Matches not greater than this
288 * are discarded. This is used in the lazy match evaluation.
291 uInt max_chain_length;
292 /* To speed up deflation, hash chains are never searched beyond this
293 * length. A higher limit improves compression ratio but degrades the
298 /* Attempt to find a better match only when the current match is strictly
299 * smaller than this value. This mechanism is used only for compression
302 # define max_insert_length max_lazy_match
303 /* Insert new strings in the hash table only if the match length is not
304 * greater than this length. This saves time but degrades compression.
305 * max_insert_length is used only for compression levels <= 3.
308 int level; /* compression level (1..9) */
309 int strategy; /* favor or force Huffman coding*/
312 /* Use a faster search when the previous match is longer than this */
314 int nice_match; /* Stop searching when current match exceeds this */
316 /* used by trees.c: */
317 /* Didn't use ct_data typedef below to supress compiler warning */
318 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
319 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
320 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
322 struct tree_desc_s l_desc; /* desc. for literal tree */
323 struct tree_desc_s d_desc; /* desc. for distance tree */
324 struct tree_desc_s bl_desc; /* desc. for bit length tree */
326 ush bl_count[MAX_BITS+1];
327 /* number of codes at each bit length for an optimal tree */
329 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
330 int heap_len; /* number of elements in the heap */
331 int heap_max; /* element of largest frequency */
332 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
333 * The same heap array is used to build all trees.
336 uch depth[2*L_CODES+1];
337 /* Depth of each subtree used as tie breaker for trees of equal frequency
340 uchf *l_buf; /* buffer for literals or lengths */
343 /* Size of match buffer for literals/lengths. There are 4 reasons for
344 * limiting lit_bufsize to 64K:
345 * - frequencies can be kept in 16 bit counters
346 * - if compression is not successful for the first block, all input
347 * data is still in the window so we can still emit a stored block even
348 * when input comes from standard input. (This can also be done for
349 * all blocks if lit_bufsize is not greater than 32K.)
350 * - if compression is not successful for a file smaller than 64K, we can
351 * even emit a stored file instead of a stored block (saving 5 bytes).
352 * This is applicable only for zip (not gzip or zlib).
353 * - creating new Huffman trees less frequently may not provide fast
354 * adaptation to changes in the input data statistics. (Take for
355 * example a binary file with poorly compressible code followed by
356 * a highly compressible string table.) Smaller buffer sizes give
357 * fast adaptation but have of course the overhead of transmitting
358 * trees more frequently.
359 * - I can't count above 4
362 uInt last_lit; /* running index in l_buf */
365 /* Buffer for distances. To simplify the code, d_buf and l_buf have
366 * the same number of elements. To use different lengths, an extra flag
367 * array would be necessary.
370 ulg opt_len; /* bit length of current block with optimal trees */
371 ulg static_len; /* bit length of current block with static trees */
372 ulg compressed_len; /* total bit length of compressed file */
373 uInt matches; /* number of string matches in current block */
374 int last_eob_len; /* bit length of EOB code for last block */
377 ulg bits_sent; /* bit length of the compressed data */
381 /* Output buffer. bits are inserted starting at the bottom (least
385 /* Number of valid bits in bi_buf. All bits above the last valid bit
389 uInt blocks_in_packet;
390 /* Number of blocks produced since the last time Z_PACKET_FLUSH
396 /* Output a byte on the stream.
397 * IN assertion: there is enough room in pending_buf.
399 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
402 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
403 /* Minimum amount of lookahead, except at the end of the input file.
404 * See deflate.c for comments about the MIN_MATCH+1.
407 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
408 /* In order to simplify the code, particularly on 16 bit machines, match
409 * distances are limited to MAX_DIST instead of WSIZE.
413 local void ct_init OF((deflate_state *s));
414 local int ct_tally OF((deflate_state *s, int dist, int lc));
415 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
417 local void ct_align OF((deflate_state *s));
418 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
420 local void ct_stored_type_only OF((deflate_state *s));
424 /* deflate.c -- compress data using the deflation algorithm
425 * Copyright (C) 1995 Jean-loup Gailly.
426 * For conditions of distribution and use, see copyright notice in zlib.h
432 * The "deflation" process depends on being able to identify portions
433 * of the input text which are identical to earlier input (within a
434 * sliding window trailing behind the input currently being processed).
436 * The most straightforward technique turns out to be the fastest for
437 * most input files: try all possible matches and select the longest.
438 * The key feature of this algorithm is that insertions into the string
439 * dictionary are very simple and thus fast, and deletions are avoided
440 * completely. Insertions are performed at each input character, whereas
441 * string matches are performed only when the previous match ends. So it
442 * is preferable to spend more time in matches to allow very fast string
443 * insertions and avoid deletions. The matching algorithm for small
444 * strings is inspired from that of Rabin & Karp. A brute force approach
445 * is used to find longer strings when a small match has been found.
446 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
447 * (by Leonid Broukhis).
448 * A previous version of this file used a more sophisticated algorithm
449 * (by Fiala and Greene) which is guaranteed to run in linear amortized
450 * time, but has a larger average cost, uses more memory and is patented.
451 * However the F&G algorithm may be faster for some highly redundant
452 * files if the parameter max_chain_length (described below) is too large.
456 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
457 * I found it in 'freeze' written by Leonid Broukhis.
458 * Thanks to many people for bug reports and testing.
462 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
463 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
465 * A description of the Rabin and Karp algorithm is given in the book
466 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
468 * Fiala,E.R., and Greene,D.H.
469 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
473 /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */
475 local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
477 If you use the zlib library in a product, an acknowledgment is welcome
478 in the documentation of your product. If for some reason you cannot
479 include such an acknowledgment, I would appreciate that you keep this
480 copyright string in the executable of your product.
484 /* Tail of hash chains */
487 # define TOO_FAR 4096
489 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
491 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
492 /* Minimum amount of lookahead, except at the end of the input file.
493 * See deflate.c for comments about the MIN_MATCH+1.
496 /* Values for max_lazy_match, good_match and max_chain_length, depending on
497 * the desired pack level (0..9). The values given below have been tuned to
498 * exclude worst case performance for pathological files. Better values may be
499 * found for specific files.
502 typedef struct config_s {
503 ush good_length; /* reduce lazy search above this match length */
504 ush max_lazy; /* do not perform lazy search above this match length */
505 ush nice_length; /* quit search above this match length */
509 local config configuration_table[10] = {
510 /* good lazy nice chain */
511 /* 0 */ {0, 0, 0, 0}, /* store only */
512 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
513 /* 2 */ {4, 5, 16, 8},
514 /* 3 */ {4, 6, 32, 32},
516 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
517 /* 5 */ {8, 16, 32, 32},
518 /* 6 */ {8, 16, 128, 128},
519 /* 7 */ {8, 32, 128, 256},
520 /* 8 */ {32, 128, 258, 1024},
521 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
523 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
524 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
529 /* result of memcmp for equal strings */
531 /* ===========================================================================
532 * Prototypes for local functions.
535 local void fill_window OF((deflate_state *s));
536 local int deflate_fast OF((deflate_state *s, int flush));
537 local int deflate_slow OF((deflate_state *s, int flush));
538 local void lm_init OF((deflate_state *s));
539 local int longest_match OF((deflate_state *s, IPos cur_match));
540 local void putShortMSB OF((deflate_state *s, uInt b));
541 local void flush_pending OF((z_stream *strm));
542 local int read_buf OF((z_stream *strm, charf *buf, unsigned size));
544 void match_init OF((void)); /* asm code initialization */
548 local void check_match OF((deflate_state *s, IPos start, IPos match,
553 /* ===========================================================================
554 * Update a hash value with the given input byte
555 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
556 * input characters, so that a running hash key can be computed from the
557 * previous key instead of complete recalculation each time.
559 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
562 /* ===========================================================================
563 * Insert string str in the dictionary and set match_head to the previous head
564 * of the hash chain (the most recent string with same hash key). Return
565 * the previous length of the hash chain.
566 * IN assertion: all calls to to INSERT_STRING are made with consecutive
567 * input characters and the first MIN_MATCH bytes of str are valid
568 * (except for the last MIN_MATCH-1 bytes of the input file).
570 #define INSERT_STRING(s, str, match_head) \
571 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
572 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
573 s->head[s->ins_h] = (str))
575 /* ===========================================================================
576 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
577 * prev[] will be initialized on the fly.
579 #define CLEAR_HASH(s) \
580 s->head[s->hash_size-1] = NIL; \
581 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
583 /* ========================================================================= */
584 int deflateInit (strm, level)
588 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
590 /* To do: ignore strm->next_in if we use it as window */
593 /* ========================================================================= */
594 int deflateInit2 (strm, level, method, windowBits, memLevel,
595 strategy, minCompression)
607 if (strm == Z_NULL) return Z_STREAM_ERROR;
610 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
611 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
613 if (level == Z_DEFAULT_COMPRESSION) level = 6;
615 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
617 windowBits = -windowBits;
619 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
620 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
621 return Z_STREAM_ERROR;
623 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
624 if (s == Z_NULL) return Z_MEM_ERROR;
625 strm->state = (struct internal_state FAR *)s;
628 s->noheader = noheader;
629 s->w_bits = windowBits;
630 s->w_size = 1 << s->w_bits;
631 s->w_mask = s->w_size - 1;
633 s->hash_bits = memLevel + 7;
634 s->hash_size = 1 << s->hash_bits;
635 s->hash_mask = s->hash_size - 1;
636 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
638 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
639 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
640 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
642 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
644 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
646 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
647 s->pending_buf == Z_NULL) {
648 strm->msg = z_errmsg[1-Z_MEM_ERROR];
652 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
653 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
654 /* We overlay pending_buf and d_buf+l_buf. This works since the average
655 * output size for (length,distance) codes is <= 32 bits (worst case
660 s->strategy = strategy;
661 s->method = (Byte)method;
662 s->minCompr = minCompression;
663 s->blocks_in_packet = 0;
665 return deflateReset(strm);
668 /* ========================================================================= */
669 int deflateReset (strm)
674 if (strm == Z_NULL || strm->state == Z_NULL ||
675 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
677 strm->total_in = strm->total_out = 0;
678 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
679 strm->data_type = Z_UNKNOWN;
681 s = (deflate_state *)strm->state;
683 s->pending_out = s->pending_buf;
685 if (s->noheader < 0) {
686 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
688 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
697 /* =========================================================================
698 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
699 * IN assertion: the stream state is correct and there is enough room in
702 local void putShortMSB (s, b)
706 put_byte(s, (Byte)(b >> 8));
707 put_byte(s, (Byte)(b & 0xff));
710 /* =========================================================================
711 * Flush as much pending output as possible.
713 local void flush_pending(strm)
716 deflate_state *state = (deflate_state *) strm->state;
717 unsigned len = state->pending;
719 if (len > strm->avail_out) len = strm->avail_out;
720 if (len == 0) return;
722 if (strm->next_out != NULL) {
723 zmemcpy(strm->next_out, state->pending_out, len);
724 strm->next_out += len;
726 state->pending_out += len;
727 strm->total_out += len;
728 strm->avail_out -= len;
729 state->pending -= len;
730 if (state->pending == 0) {
731 state->pending_out = state->pending_buf;
735 /* ========================================================================= */
736 int deflate (strm, flush)
740 deflate_state *state = (deflate_state *) strm->state;
742 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
744 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
745 ERR_RETURN(strm, Z_STREAM_ERROR);
747 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
749 state->strm = strm; /* just in case */
751 /* Write the zlib header */
752 if (state->status == INIT_STATE) {
754 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
755 uInt level_flags = (state->level-1) >> 1;
757 if (level_flags > 3) level_flags = 3;
758 header |= (level_flags << 6);
759 header += 31 - (header % 31);
761 state->status = BUSY_STATE;
762 putShortMSB(state, header);
765 /* Flush as much pending output as possible */
766 if (state->pending != 0) {
768 if (strm->avail_out == 0) return Z_OK;
771 /* If we came back in here to get the last output from
772 * a previous flush, we're done for now.
774 if (state->status == FLUSH_STATE) {
775 state->status = BUSY_STATE;
776 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
780 /* User must not provide more input after the first FINISH: */
781 if (state->status == FINISH_STATE && strm->avail_in != 0) {
782 ERR_RETURN(strm, Z_BUF_ERROR);
785 /* Start a new block or continue the current one.
787 if (strm->avail_in != 0 || state->lookahead != 0 ||
788 (flush == Z_FINISH && state->status != FINISH_STATE)) {
791 if (flush == Z_FINISH) {
792 state->status = FINISH_STATE;
794 if (state->level <= 3) {
795 quit = deflate_fast(state, flush);
797 quit = deflate_slow(state, flush);
799 if (quit || strm->avail_out == 0)
801 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
802 * of deflate should use the same flush parameter to make sure
803 * that the flush is complete. So we don't have to output an
804 * empty block here, this will be done at next call. This also
805 * ensures that for a very small output buffer, we emit at most
810 /* If a flush was requested, we have a little more to output now. */
811 if (flush != Z_NO_FLUSH && flush != Z_FINISH
812 && state->status != FINISH_STATE) {
814 case Z_PARTIAL_FLUSH:
818 /* Output just the 3-bit `stored' block type value,
819 but not a zero length. */
820 ct_stored_type_only(state);
823 ct_stored_block(state, (char*)0, 0L, 0);
824 /* For a full flush, this empty block will be recognized
825 * as a special marker by inflate_sync().
827 if (flush == Z_FULL_FLUSH) {
828 CLEAR_HASH(state); /* forget history */
832 if (strm->avail_out == 0) {
833 /* We'll have to come back to get the rest of the output;
834 * this ensures we don't output a second zero-length stored
835 * block (or whatever).
837 state->status = FLUSH_STATE;
842 Assert(strm->avail_out > 0, "bug2");
844 if (flush != Z_FINISH) return Z_OK;
845 if (state->noheader) return Z_STREAM_END;
847 /* Write the zlib trailer (adler32) */
848 putShortMSB(state, (uInt)(state->adler >> 16));
849 putShortMSB(state, (uInt)(state->adler & 0xffff));
851 /* If avail_out is zero, the application will call deflate again
854 state->noheader = -1; /* write the trailer only once! */
855 return state->pending != 0 ? Z_OK : Z_STREAM_END;
858 /* ========================================================================= */
859 int deflateEnd (strm)
862 deflate_state *state = (deflate_state *) strm->state;
864 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
866 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
867 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
868 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
869 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
871 ZFREE(strm, state, sizeof(deflate_state));
872 strm->state = Z_NULL;
877 /* ===========================================================================
878 * Read a new buffer from the current input stream, update the adler32
879 * and total number of bytes read.
881 local int read_buf(strm, buf, size)
886 unsigned len = strm->avail_in;
887 deflate_state *state = (deflate_state *) strm->state;
889 if (len > size) len = size;
890 if (len == 0) return 0;
892 strm->avail_in -= len;
894 if (!state->noheader) {
895 state->adler = adler32(state->adler, strm->next_in, len);
897 zmemcpy(buf, strm->next_in, len);
898 strm->next_in += len;
899 strm->total_in += len;
904 /* ===========================================================================
905 * Initialize the "longest match" routines for a new zlib stream
907 local void lm_init (s)
910 s->window_size = (ulg)2L*s->w_size;
914 /* Set the default configuration parameters:
916 s->max_lazy_match = configuration_table[s->level].max_lazy;
917 s->good_match = configuration_table[s->level].good_length;
918 s->nice_match = configuration_table[s->level].nice_length;
919 s->max_chain_length = configuration_table[s->level].max_chain;
924 s->match_length = MIN_MATCH-1;
925 s->match_available = 0;
928 match_init(); /* initialize the asm code */
932 /* ===========================================================================
933 * Set match_start to the longest match starting at the given string and
934 * return its length. Matches shorter or equal to prev_length are discarded,
935 * in which case the result is equal to prev_length and match_start is
937 * IN assertions: cur_match is the head of the hash chain for the current
938 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
941 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
942 * match.S. The code will be functionally equivalent.
944 local int longest_match(s, cur_match)
946 IPos cur_match; /* current match */
948 unsigned chain_length = s->max_chain_length;/* max hash chain length */
949 register Bytef *scan = s->window + s->strstart; /* current string */
950 register Bytef *match; /* matched string */
951 register int len; /* length of current match */
952 int best_len = s->prev_length; /* best match length so far */
953 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
954 s->strstart - (IPos)MAX_DIST(s) : NIL;
955 /* Stop when cur_match becomes <= limit. To simplify the code,
956 * we prevent matches with the string of window index 0.
958 Posf *prev = s->prev;
959 uInt wmask = s->w_mask;
962 /* Compare two bytes at a time. Note: this is not always beneficial.
963 * Try with and without -DUNALIGNED_OK to check.
965 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
966 register ush scan_start = *(ushf*)scan;
967 register ush scan_end = *(ushf*)(scan+best_len-1);
969 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
970 register Byte scan_end1 = scan[best_len-1];
971 register Byte scan_end = scan[best_len];
974 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
975 * It is easy to get rid of this optimization if necessary.
977 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
979 /* Do not waste too much time if we already have a good match: */
980 if (s->prev_length >= s->good_match) {
983 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
986 Assert(cur_match < s->strstart, "no future");
987 match = s->window + cur_match;
989 /* Skip to next match if the match length cannot increase
990 * or if the match length is less than 2:
992 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
993 /* This code assumes sizeof(unsigned short) == 2. Do not use
994 * UNALIGNED_OK if your compiler uses a different size.
996 if (*(ushf*)(match+best_len-1) != scan_end ||
997 *(ushf*)match != scan_start) continue;
999 /* It is not necessary to compare scan[2] and match[2] since they are
1000 * always equal when the other bytes match, given that the hash keys
1001 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1002 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1003 * lookahead only every 4th comparison; the 128th check will be made
1004 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1005 * necessary to put more guard bytes at the end of the window, or
1006 * to check more often for insufficient lookahead.
1008 Assert(scan[2] == match[2], "scan[2]?");
1011 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1012 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1013 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1014 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1016 /* The funny "do {}" generates better code on most compilers */
1018 /* Here, scan <= window+strstart+257 */
1019 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1020 if (*scan == *match) scan++;
1022 len = (MAX_MATCH - 1) - (int)(strend-scan);
1023 scan = strend - (MAX_MATCH-1);
1025 #else /* UNALIGNED_OK */
1027 if (match[best_len] != scan_end ||
1028 match[best_len-1] != scan_end1 ||
1030 *++match != scan[1]) continue;
1032 /* The check at best_len-1 can be removed because it will be made
1033 * again later. (This heuristic is not always a win.)
1034 * It is not necessary to compare scan[2] and match[2] since they
1035 * are always equal when the other bytes match, given that
1036 * the hash keys are equal and that HASH_BITS >= 8.
1039 Assert(*scan == *match, "match[2]?");
1041 /* We check for insufficient lookahead only every 8th comparison;
1042 * the 256th check will be made at strstart+258.
1045 } while (*++scan == *++match && *++scan == *++match &&
1046 *++scan == *++match && *++scan == *++match &&
1047 *++scan == *++match && *++scan == *++match &&
1048 *++scan == *++match && *++scan == *++match &&
1051 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1053 len = MAX_MATCH - (int)(strend - scan);
1054 scan = strend - MAX_MATCH;
1056 #endif /* UNALIGNED_OK */
1058 if (len > best_len) {
1059 s->match_start = cur_match;
1061 if (len >= s->nice_match) break;
1063 scan_end = *(ushf*)(scan+best_len-1);
1065 scan_end1 = scan[best_len-1];
1066 scan_end = scan[best_len];
1069 } while ((cur_match = prev[cur_match & wmask]) > limit
1070 && --chain_length != 0);
1077 /* ===========================================================================
1078 * Check that the match at match_start is indeed a match.
1080 local void check_match(s, start, match, length)
1085 /* check that the match is indeed a match */
1086 if (memcmp((charf *)s->window + match,
1087 (charf *)s->window + start, length) != EQUAL) {
1089 " start %u, match %u, length %d\n",
1090 start, match, length);
1091 do { fprintf(stderr, "%c%c", s->window[match++],
1092 s->window[start++]); } while (--length != 0);
1093 z_error("invalid match");
1096 fprintf(stderr,"\\[%d,%d]", start-match, length);
1097 do { putc(s->window[start++], stderr); } while (--length != 0);
1101 # define check_match(s, start, match, length)
1104 /* ===========================================================================
1105 * Fill the window when the lookahead becomes insufficient.
1106 * Updates strstart and lookahead.
1108 * IN assertion: lookahead < MIN_LOOKAHEAD
1109 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1110 * At least one byte has been read, or avail_in == 0; reads are
1111 * performed for at least two bytes (required for the zip translate_eol
1112 * option -- not supported here).
1114 local void fill_window(s)
1117 register unsigned n, m;
1119 unsigned more; /* Amount of free space at the end of the window. */
1120 uInt wsize = s->w_size;
1123 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1125 /* Deal with !@#$% 64K limit: */
1126 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1128 } else if (more == (unsigned)(-1)) {
1129 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1130 * and lookahead == 1 (input done one byte at time)
1134 /* If the window is almost full and there is insufficient lookahead,
1135 * move the upper half to the lower one to make room in the upper half.
1137 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1139 /* By the IN assertion, the window is not empty so we can't confuse
1140 * more == 0 with more == 64K on a 16 bit machine.
1142 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1144 s->match_start -= wsize;
1145 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1147 s->block_start -= (long) wsize;
1149 /* Slide the hash table (could be avoided with 32 bit values
1150 at the expense of memory usage):
1156 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1163 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1164 /* If n is not on any hash chain, prev[n] is garbage but
1165 * its value will never be used.
1171 if (s->strm->avail_in == 0) return;
1173 /* If there was no sliding:
1174 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1175 * more == window_size - lookahead - strstart
1176 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1177 * => more >= window_size - 2*WSIZE + 2
1178 * In the BIG_MEM or MMAP case (not yet supported),
1179 * window_size == input_size + MIN_LOOKAHEAD &&
1180 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1181 * Otherwise, window_size == 2*WSIZE so more >= 2.
1182 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1184 Assert(more >= 2, "more < 2");
1186 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1190 /* Initialize the hash value now that we have some input: */
1191 if (s->lookahead >= MIN_MATCH) {
1192 s->ins_h = s->window[s->strstart];
1193 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1195 Call UPDATE_HASH() MIN_MATCH-3 more times
1198 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1199 * but this is not important since only literal bytes will be emitted.
1202 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1205 /* ===========================================================================
1206 * Flush the current block, with given end-of-file flag.
1207 * IN assertion: strstart is set to the end of the current match.
1209 #define FLUSH_BLOCK_ONLY(s, flush) { \
1210 ct_flush_block(s, (s->block_start >= 0L ? \
1211 (charf *)&s->window[(unsigned)s->block_start] : \
1212 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1213 s->block_start = s->strstart; \
1214 flush_pending(s->strm); \
1215 Tracev((stderr,"[FLUSH]")); \
1218 /* Same but force premature exit if necessary. */
1219 #define FLUSH_BLOCK(s, flush) { \
1220 FLUSH_BLOCK_ONLY(s, flush); \
1221 if (s->strm->avail_out == 0) return 1; \
1224 /* ===========================================================================
1225 * Compress as much as possible from the input stream, return true if
1226 * processing was terminated prematurely (no more input or output space).
1227 * This function does not perform lazy evaluationof matches and inserts
1228 * new strings in the dictionary only for unmatched strings or for short
1229 * matches. It is used only for the fast compression options.
1231 local int deflate_fast(s, flush)
1235 IPos hash_head = NIL; /* head of the hash chain */
1236 int bflush; /* set if current block must be flushed */
1238 s->prev_length = MIN_MATCH-1;
1241 /* Make sure that we always have enough lookahead, except
1242 * at the end of the input file. We need MAX_MATCH bytes
1243 * for the next match, plus MIN_MATCH bytes to insert the
1244 * string following the next match.
1246 if (s->lookahead < MIN_LOOKAHEAD) {
1248 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1250 if (s->lookahead == 0) break; /* flush the current block */
1253 /* Insert the string window[strstart .. strstart+2] in the
1254 * dictionary, and set hash_head to the head of the hash chain:
1256 if (s->lookahead >= MIN_MATCH) {
1257 INSERT_STRING(s, s->strstart, hash_head);
1260 /* Find the longest match, discarding those <= prev_length.
1261 * At this point we have always match_length < MIN_MATCH
1263 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1264 /* To simplify the code, we prevent matches with the string
1265 * of window index 0 (in particular we have to avoid a match
1266 * of the string with itself at the start of the input file).
1268 if (s->strategy != Z_HUFFMAN_ONLY) {
1269 s->match_length = longest_match (s, hash_head);
1271 /* longest_match() sets match_start */
1273 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1275 if (s->match_length >= MIN_MATCH) {
1276 check_match(s, s->strstart, s->match_start, s->match_length);
1278 bflush = ct_tally(s, s->strstart - s->match_start,
1279 s->match_length - MIN_MATCH);
1281 s->lookahead -= s->match_length;
1283 /* Insert new strings in the hash table only if the match length
1284 * is not too large. This saves time but degrades compression.
1286 if (s->match_length <= s->max_insert_length &&
1287 s->lookahead >= MIN_MATCH) {
1288 s->match_length--; /* string at strstart already in hash table */
1291 INSERT_STRING(s, s->strstart, hash_head);
1292 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1293 * always MIN_MATCH bytes ahead.
1295 } while (--s->match_length != 0);
1298 s->strstart += s->match_length;
1299 s->match_length = 0;
1300 s->ins_h = s->window[s->strstart];
1301 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1303 Call UPDATE_HASH() MIN_MATCH-3 more times
1305 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1306 * matter since it will be recomputed at next deflate call.
1310 /* No match, output a literal byte */
1311 Tracevv((stderr,"%c", s->window[s->strstart]));
1312 bflush = ct_tally (s, 0, s->window[s->strstart]);
1316 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1318 FLUSH_BLOCK(s, flush);
1319 return 0; /* normal exit */
1322 /* ===========================================================================
1323 * Same as above, but achieves better compression. We use a lazy
1324 * evaluation for matches: a match is finally adopted only if there is
1325 * no better match at the next window position.
1327 local int deflate_slow(s, flush)
1331 IPos hash_head = NIL; /* head of hash chain */
1332 int bflush; /* set if current block must be flushed */
1334 /* Process the input block. */
1336 /* Make sure that we always have enough lookahead, except
1337 * at the end of the input file. We need MAX_MATCH bytes
1338 * for the next match, plus MIN_MATCH bytes to insert the
1339 * string following the next match.
1341 if (s->lookahead < MIN_LOOKAHEAD) {
1343 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1345 if (s->lookahead == 0) break; /* flush the current block */
1348 /* Insert the string window[strstart .. strstart+2] in the
1349 * dictionary, and set hash_head to the head of the hash chain:
1351 if (s->lookahead >= MIN_MATCH) {
1352 INSERT_STRING(s, s->strstart, hash_head);
1355 /* Find the longest match, discarding those <= prev_length.
1357 s->prev_length = s->match_length, s->prev_match = s->match_start;
1358 s->match_length = MIN_MATCH-1;
1360 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1361 s->strstart - hash_head <= MAX_DIST(s)) {
1362 /* To simplify the code, we prevent matches with the string
1363 * of window index 0 (in particular we have to avoid a match
1364 * of the string with itself at the start of the input file).
1366 if (s->strategy != Z_HUFFMAN_ONLY) {
1367 s->match_length = longest_match (s, hash_head);
1369 /* longest_match() sets match_start */
1370 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1372 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1373 (s->match_length == MIN_MATCH &&
1374 s->strstart - s->match_start > TOO_FAR))) {
1376 /* If prev_match is also MIN_MATCH, match_start is garbage
1377 * but we will ignore the current match anyway.
1379 s->match_length = MIN_MATCH-1;
1382 /* If there was a match at the previous step and the current
1383 * match is not better, output the previous match:
1385 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1386 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1387 /* Do not insert strings in hash table beyond this. */
1389 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1391 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1392 s->prev_length - MIN_MATCH);
1394 /* Insert in hash table all strings up to the end of the match.
1395 * strstart-1 and strstart are already inserted. If there is not
1396 * enough lookahead, the last two strings are not inserted in
1399 s->lookahead -= s->prev_length-1;
1400 s->prev_length -= 2;
1402 if (++s->strstart <= max_insert) {
1403 INSERT_STRING(s, s->strstart, hash_head);
1405 } while (--s->prev_length != 0);
1406 s->match_available = 0;
1407 s->match_length = MIN_MATCH-1;
1410 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1412 } else if (s->match_available) {
1413 /* If there was no match at the previous position, output a
1414 * single literal. If there was a match but the current match
1415 * is longer, truncate the previous match to a single literal.
1417 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1418 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1419 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1423 if (s->strm->avail_out == 0) return 1;
1425 /* There is no previous match to compare with, wait for
1426 * the next step to decide.
1428 s->match_available = 1;
1433 Assert (flush != Z_NO_FLUSH, "no flush?");
1434 if (s->match_available) {
1435 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1436 ct_tally (s, 0, s->window[s->strstart-1]);
1437 s->match_available = 0;
1439 FLUSH_BLOCK(s, flush);
1445 /* trees.c -- output deflated data using Huffman coding
1446 * Copyright (C) 1995 Jean-loup Gailly
1447 * For conditions of distribution and use, see copyright notice in zlib.h
1453 * The "deflation" process uses several Huffman trees. The more
1454 * common source values are represented by shorter bit sequences.
1456 * Each code tree is stored in a compressed form which is itself
1457 * a Huffman encoding of the lengths of all the code strings (in
1458 * ascending order by source values). The actual code strings are
1459 * reconstructed from the lengths in the inflate process, as described
1460 * in the deflate specification.
1464 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1465 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1468 * Data Compression: Methods and Theory, pp. 49-50.
1469 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1473 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1476 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
1482 /* ===========================================================================
1486 #define MAX_BL_BITS 7
1487 /* Bit length codes must not exceed MAX_BL_BITS bits */
1489 #define END_BLOCK 256
1490 /* end of block literal code */
1493 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1495 #define REPZ_3_10 17
1496 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1498 #define REPZ_11_138 18
1499 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1501 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1502 = {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};
1504 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1505 = {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};
1507 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1508 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1510 local uch bl_order[BL_CODES]
1511 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1512 /* The lengths of the bit length codes are sent in order of decreasing
1513 * probability, to avoid transmitting the lengths for unused bit length codes.
1516 #define Buf_size (8 * 2*sizeof(char))
1517 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1518 * more than 16 bits on some systems.)
1521 /* ===========================================================================
1522 * Local data. These are initialized only once.
1523 * To do: initialize at compile time to be completely reentrant. ???
1526 local ct_data static_ltree[L_CODES+2];
1527 /* The static literal tree. Since the bit lengths are imposed, there is no
1528 * need for the L_CODES extra codes used during heap construction. However
1529 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1533 local ct_data static_dtree[D_CODES];
1534 /* The static distance tree. (Actually a trivial tree since all codes use
1538 local uch dist_code[512];
1539 /* distance codes. The first 256 values correspond to the distances
1540 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1541 * the 15 bit distances.
1544 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1545 /* length code for each normalized match length (0 == MIN_MATCH) */
1547 local int base_length[LENGTH_CODES];
1548 /* First normalized length for each code (0 = MIN_MATCH) */
1550 local int base_dist[D_CODES];
1551 /* First normalized distance for each code (0 = distance of 1) */
1553 struct static_tree_desc_s {
1554 ct_data *static_tree; /* static tree or NULL */
1555 intf *extra_bits; /* extra bits for each code or NULL */
1556 int extra_base; /* base index for extra_bits */
1557 int elems; /* max number of elements in the tree */
1558 int max_length; /* max bit length for the codes */
1561 local static_tree_desc static_l_desc =
1562 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1564 local static_tree_desc static_d_desc =
1565 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1567 local static_tree_desc static_bl_desc =
1568 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1570 /* ===========================================================================
1571 * Local (static) routines in this file.
1574 local void ct_static_init OF((void));
1575 local void init_block OF((deflate_state *s));
1576 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1577 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1578 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1579 local void build_tree OF((deflate_state *s, tree_desc *desc));
1580 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1581 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1582 local int build_bl_tree OF((deflate_state *s));
1583 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1585 local void compress_block OF((deflate_state *s, ct_data *ltree,
1587 local void set_data_type OF((deflate_state *s));
1588 local unsigned bi_reverse OF((unsigned value, int length));
1589 local void bi_windup OF((deflate_state *s));
1590 local void bi_flush OF((deflate_state *s));
1591 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1595 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1596 /* Send a code of the given tree. c and tree must not have side effects */
1598 #else /* DEBUG_ZLIB */
1599 # define send_code(s, c, tree) \
1600 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1601 send_bits(s, tree[c].Code, tree[c].Len); }
1604 #define d_code(dist) \
1605 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1606 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1607 * must not have side effects. dist_code[256] and dist_code[257] are never
1611 /* ===========================================================================
1612 * Output a short LSB first on the stream.
1613 * IN assertion: there is enough room in pendingBuf.
1615 #define put_short(s, w) { \
1616 put_byte(s, (uch)((w) & 0xff)); \
1617 put_byte(s, (uch)((ush)(w) >> 8)); \
1620 /* ===========================================================================
1621 * Send a value on a given number of bits.
1622 * IN assertion: length <= 16 and value fits in length bits.
1625 local void send_bits OF((deflate_state *s, int value, int length));
1627 local void send_bits(s, value, length)
1629 int value; /* value to send */
1630 int length; /* number of bits */
1632 Tracev((stderr," l %2d v %4x ", length, value));
1633 Assert(length > 0 && length <= 15, "invalid length");
1634 s->bits_sent += (ulg)length;
1636 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1637 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1638 * unused bits in value.
1640 if (s->bi_valid > (int)Buf_size - length) {
1641 s->bi_buf |= (value << s->bi_valid);
1642 put_short(s, s->bi_buf);
1643 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1644 s->bi_valid += length - Buf_size;
1646 s->bi_buf |= value << s->bi_valid;
1647 s->bi_valid += length;
1650 #else /* !DEBUG_ZLIB */
1652 #define send_bits(s, value, length) \
1653 { int len = length;\
1654 if (s->bi_valid > (int)Buf_size - len) {\
1656 s->bi_buf |= (val << s->bi_valid);\
1657 put_short(s, s->bi_buf);\
1658 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1659 s->bi_valid += len - Buf_size;\
1661 s->bi_buf |= (value) << s->bi_valid;\
1662 s->bi_valid += len;\
1665 #endif /* DEBUG_ZLIB */
1668 #define MAX(a,b) (a >= b ? a : b)
1669 /* the arguments must not have side effects */
1671 /* ===========================================================================
1672 * Initialize the various 'constant' tables.
1673 * To do: do this at compile time.
1675 local void ct_static_init()
1677 int n; /* iterates over tree elements */
1678 int bits; /* bit counter */
1679 int length; /* length value */
1680 int code; /* code value */
1681 int dist; /* distance index */
1682 ush bl_count[MAX_BITS+1];
1683 /* number of codes at each bit length for an optimal tree */
1685 /* Initialize the mapping length (0..255) -> length code (0..28) */
1687 for (code = 0; code < LENGTH_CODES-1; code++) {
1688 base_length[code] = length;
1689 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1690 length_code[length++] = (uch)code;
1693 Assert (length == 256, "ct_static_init: length != 256");
1694 /* Note that the length 255 (match length 258) can be represented
1695 * in two different ways: code 284 + 5 bits or code 285, so we
1696 * overwrite length_code[255] to use the best encoding:
1698 length_code[length-1] = (uch)code;
1700 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1702 for (code = 0 ; code < 16; code++) {
1703 base_dist[code] = dist;
1704 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1705 dist_code[dist++] = (uch)code;
1708 Assert (dist == 256, "ct_static_init: dist != 256");
1709 dist >>= 7; /* from now on, all distances are divided by 128 */
1710 for ( ; code < D_CODES; code++) {
1711 base_dist[code] = dist << 7;
1712 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1713 dist_code[256 + dist++] = (uch)code;
1716 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1718 /* Construct the codes of the static literal tree */
1719 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1721 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1722 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1723 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1724 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1725 /* Codes 286 and 287 do not exist, but we must include them in the
1726 * tree construction to get a canonical Huffman tree (longest code
1729 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1731 /* The static distance tree is trivial: */
1732 for (n = 0; n < D_CODES; n++) {
1733 static_dtree[n].Len = 5;
1734 static_dtree[n].Code = bi_reverse(n, 5);
1738 /* ===========================================================================
1739 * Initialize the tree data structures for a new zlib stream.
1741 local void ct_init(s)
1744 if (static_dtree[0].Len == 0) {
1745 ct_static_init(); /* To do: at compile time */
1748 s->compressed_len = 0L;
1750 s->l_desc.dyn_tree = s->dyn_ltree;
1751 s->l_desc.stat_desc = &static_l_desc;
1753 s->d_desc.dyn_tree = s->dyn_dtree;
1754 s->d_desc.stat_desc = &static_d_desc;
1756 s->bl_desc.dyn_tree = s->bl_tree;
1757 s->bl_desc.stat_desc = &static_bl_desc;
1761 s->last_eob_len = 8; /* enough lookahead for inflate */
1765 s->blocks_in_packet = 0;
1767 /* Initialize the first block of the first file: */
1771 /* ===========================================================================
1772 * Initialize a new block.
1774 local void init_block(s)
1777 int n; /* iterates over tree elements */
1779 /* Initialize the trees. */
1780 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1781 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1782 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1784 s->dyn_ltree[END_BLOCK].Freq = 1;
1785 s->opt_len = s->static_len = 0L;
1786 s->last_lit = s->matches = 0;
1790 /* Index within the heap array of least frequent node in the Huffman tree */
1793 /* ===========================================================================
1794 * Remove the smallest element from the heap and recreate the heap with
1795 * one less element. Updates heap and heap_len.
1797 #define pqremove(s, tree, top) \
1799 top = s->heap[SMALLEST]; \
1800 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1801 pqdownheap(s, tree, SMALLEST); \
1804 /* ===========================================================================
1805 * Compares to subtrees, using the tree depth as tie breaker when
1806 * the subtrees have equal frequency. This minimizes the worst case length.
1808 #define smaller(tree, n, m, depth) \
1809 (tree[n].Freq < tree[m].Freq || \
1810 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1812 /* ===========================================================================
1813 * Restore the heap property by moving down the tree starting at node k,
1814 * exchanging a node with the smallest of its two sons if necessary, stopping
1815 * when the heap property is re-established (each father smaller than its
1818 local void pqdownheap(s, tree, k)
1820 ct_data *tree; /* the tree to restore */
1821 int k; /* node to move down */
1824 int j = k << 1; /* left son of k */
1825 while (j <= s->heap_len) {
1826 /* Set j to the smallest of the two sons: */
1827 if (j < s->heap_len &&
1828 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1831 /* Exit if v is smaller than both sons */
1832 if (smaller(tree, v, s->heap[j], s->depth)) break;
1834 /* Exchange v with the smallest son */
1835 s->heap[k] = s->heap[j]; k = j;
1837 /* And continue down the tree, setting j to the left son of k */
1843 /* ===========================================================================
1844 * Compute the optimal bit lengths for a tree and update the total bit length
1845 * for the current block.
1846 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1847 * above are the tree nodes sorted by increasing frequency.
1848 * OUT assertions: the field len is set to the optimal bit length, the
1849 * array bl_count contains the frequencies for each bit length.
1850 * The length opt_len is updated; static_len is also updated if stree is
1853 local void gen_bitlen(s, desc)
1855 tree_desc *desc; /* the tree descriptor */
1857 ct_data *tree = desc->dyn_tree;
1858 int max_code = desc->max_code;
1859 ct_data *stree = desc->stat_desc->static_tree;
1860 intf *extra = desc->stat_desc->extra_bits;
1861 int base = desc->stat_desc->extra_base;
1862 int max_length = desc->stat_desc->max_length;
1863 int h; /* heap index */
1864 int n, m; /* iterate over the tree elements */
1865 int bits; /* bit length */
1866 int xbits; /* extra bits */
1867 ush f; /* frequency */
1868 int overflow = 0; /* number of elements with bit length too large */
1870 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1872 /* In a first pass, compute the optimal bit lengths (which may
1873 * overflow in the case of the bit length tree).
1875 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1877 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1879 bits = tree[tree[n].Dad].Len + 1;
1880 if (bits > max_length) bits = max_length, overflow++;
1881 tree[n].Len = (ush)bits;
1882 /* We overwrite tree[n].Dad which is no longer needed */
1884 if (n > max_code) continue; /* not a leaf node */
1886 s->bl_count[bits]++;
1888 if (n >= base) xbits = extra[n-base];
1890 s->opt_len += (ulg)f * (bits + xbits);
1891 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1893 if (overflow == 0) return;
1895 Trace((stderr,"\nbit length overflow\n"));
1896 /* This happens for example on obj2 and pic of the Calgary corpus */
1898 /* Find the first bit length which could increase: */
1900 bits = max_length-1;
1901 while (s->bl_count[bits] == 0) bits--;
1902 s->bl_count[bits]--; /* move one leaf down the tree */
1903 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1904 s->bl_count[max_length]--;
1905 /* The brother of the overflow item also moves one step up,
1906 * but this does not affect bl_count[max_length]
1909 } while (overflow > 0);
1911 /* Now recompute all bit lengths, scanning in increasing frequency.
1912 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1913 * lengths instead of fixing only the wrong ones. This idea is taken
1914 * from 'ar' written by Haruhiko Okumura.)
1916 for (bits = max_length; bits != 0; bits--) {
1917 n = s->bl_count[bits];
1920 if (m > max_code) continue;
1921 if (tree[m].Len != (unsigned) bits) {
1922 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1923 s->opt_len += ((long)bits - (long)tree[m].Len)
1924 *(long)tree[m].Freq;
1925 tree[m].Len = (ush)bits;
1932 /* ===========================================================================
1933 * Generate the codes for a given tree and bit counts (which need not be
1935 * IN assertion: the array bl_count contains the bit length statistics for
1936 * the given tree and the field len is set for all tree elements.
1937 * OUT assertion: the field code is set for all tree elements of non
1940 local void gen_codes (tree, max_code, bl_count)
1941 ct_data *tree; /* the tree to decorate */
1942 int max_code; /* largest code with non zero frequency */
1943 ushf *bl_count; /* number of codes at each bit length */
1945 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1946 ush code = 0; /* running code value */
1947 int bits; /* bit index */
1948 int n; /* code index */
1950 /* The distribution counts are first used to generate the code values
1951 * without bit reversal.
1953 for (bits = 1; bits <= MAX_BITS; bits++) {
1954 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1956 /* Check that the bit counts in bl_count are consistent. The last code
1959 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1960 "inconsistent bit counts");
1961 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1963 for (n = 0; n <= max_code; n++) {
1964 int len = tree[n].Len;
1965 if (len == 0) continue;
1966 /* Now reverse the bits */
1967 tree[n].Code = bi_reverse(next_code[len]++, len);
1969 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1970 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1974 /* ===========================================================================
1975 * Construct one Huffman tree and assigns the code bit strings and lengths.
1976 * Update the total bit length for the current block.
1977 * IN assertion: the field freq is set for all tree elements.
1978 * OUT assertions: the fields len and code are set to the optimal bit length
1979 * and corresponding code. The length opt_len is updated; static_len is
1980 * also updated if stree is not null. The field max_code is set.
1982 local void build_tree(s, desc)
1984 tree_desc *desc; /* the tree descriptor */
1986 ct_data *tree = desc->dyn_tree;
1987 ct_data *stree = desc->stat_desc->static_tree;
1988 int elems = desc->stat_desc->elems;
1989 int n, m; /* iterate over heap elements */
1990 int max_code = -1; /* largest code with non zero frequency */
1991 int node; /* new node being created */
1993 /* Construct the initial heap, with least frequent element in
1994 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
1995 * heap[0] is not used.
1997 s->heap_len = 0, s->heap_max = HEAP_SIZE;
1999 for (n = 0; n < elems; n++) {
2000 if (tree[n].Freq != 0) {
2001 s->heap[++(s->heap_len)] = max_code = n;
2008 /* The pkzip format requires that at least one distance code exists,
2009 * and that at least one bit should be sent even if there is only one
2010 * possible code. So to avoid special checks later on we force at least
2011 * two codes of non zero frequency.
2013 while (s->heap_len < 2) {
2014 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2015 tree[node].Freq = 1;
2017 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2018 /* node is 0 or 1 so it does not have extra bits */
2020 desc->max_code = max_code;
2022 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2023 * establish sub-heaps of increasing lengths:
2025 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2027 /* Construct the Huffman tree by repeatedly combining the least two
2030 node = elems; /* next internal node of the tree */
2032 pqremove(s, tree, n); /* n = node of least frequency */
2033 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2035 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2036 s->heap[--(s->heap_max)] = m;
2038 /* Create a new node father of n and m */
2039 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2040 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2041 tree[n].Dad = tree[m].Dad = (ush)node;
2043 if (tree == s->bl_tree) {
2044 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2045 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2048 /* and insert the new node in the heap */
2049 s->heap[SMALLEST] = node++;
2050 pqdownheap(s, tree, SMALLEST);
2052 } while (s->heap_len >= 2);
2054 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2056 /* At this point, the fields freq and dad are set. We can now
2057 * generate the bit lengths.
2059 gen_bitlen(s, (tree_desc *)desc);
2061 /* The field len is now set, we can generate the bit codes */
2062 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2065 /* ===========================================================================
2066 * Scan a literal or distance tree to determine the frequencies of the codes
2067 * in the bit length tree.
2069 local void scan_tree (s, tree, max_code)
2071 ct_data *tree; /* the tree to be scanned */
2072 int max_code; /* and its largest code of non zero frequency */
2074 int n; /* iterates over all tree elements */
2075 int prevlen = -1; /* last emitted length */
2076 int curlen; /* length of current code */
2077 int nextlen = tree[0].Len; /* length of next code */
2078 int count = 0; /* repeat count of the current code */
2079 int max_count = 7; /* max repeat count */
2080 int min_count = 4; /* min repeat count */
2082 if (nextlen == 0) max_count = 138, min_count = 3;
2083 tree[max_code+1].Len = (ush)0xffff; /* guard */
2085 for (n = 0; n <= max_code; n++) {
2086 curlen = nextlen; nextlen = tree[n+1].Len;
2087 if (++count < max_count && curlen == nextlen) {
2089 } else if (count < min_count) {
2090 s->bl_tree[curlen].Freq += count;
2091 } else if (curlen != 0) {
2092 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2093 s->bl_tree[REP_3_6].Freq++;
2094 } else if (count <= 10) {
2095 s->bl_tree[REPZ_3_10].Freq++;
2097 s->bl_tree[REPZ_11_138].Freq++;
2099 count = 0; prevlen = curlen;
2101 max_count = 138, min_count = 3;
2102 } else if (curlen == nextlen) {
2103 max_count = 6, min_count = 3;
2105 max_count = 7, min_count = 4;
2110 /* ===========================================================================
2111 * Send a literal or distance tree in compressed form, using the codes in
2114 local void send_tree (s, tree, max_code)
2116 ct_data *tree; /* the tree to be scanned */
2117 int max_code; /* and its largest code of non zero frequency */
2119 int n; /* iterates over all tree elements */
2120 int prevlen = -1; /* last emitted length */
2121 int curlen; /* length of current code */
2122 int nextlen = tree[0].Len; /* length of next code */
2123 int count = 0; /* repeat count of the current code */
2124 int max_count = 7; /* max repeat count */
2125 int min_count = 4; /* min repeat count */
2127 /* tree[max_code+1].Len = -1; */ /* guard already set */
2128 if (nextlen == 0) max_count = 138, min_count = 3;
2130 for (n = 0; n <= max_code; n++) {
2131 curlen = nextlen; nextlen = tree[n+1].Len;
2132 if (++count < max_count && curlen == nextlen) {
2134 } else if (count < min_count) {
2135 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2137 } else if (curlen != 0) {
2138 if (curlen != prevlen) {
2139 send_code(s, curlen, s->bl_tree); count--;
2141 Assert(count >= 3 && count <= 6, " 3_6?");
2142 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2144 } else if (count <= 10) {
2145 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2148 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2150 count = 0; prevlen = curlen;
2152 max_count = 138, min_count = 3;
2153 } else if (curlen == nextlen) {
2154 max_count = 6, min_count = 3;
2156 max_count = 7, min_count = 4;
2161 /* ===========================================================================
2162 * Construct the Huffman tree for the bit lengths and return the index in
2163 * bl_order of the last bit length code to send.
2165 local int build_bl_tree(s)
2168 int max_blindex; /* index of last bit length code of non zero freq */
2170 /* Determine the bit length frequencies for literal and distance trees */
2171 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2172 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2174 /* Build the bit length tree: */
2175 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2176 /* opt_len now includes the length of the tree representations, except
2177 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2180 /* Determine the number of bit length codes to send. The pkzip format
2181 * requires that at least 4 bit length codes be sent. (appnote.txt says
2182 * 3 but the actual value used is 4.)
2184 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2185 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2187 /* Update opt_len to include the bit length tree and counts */
2188 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2189 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2190 s->opt_len, s->static_len));
2195 /* ===========================================================================
2196 * Send the header for a block using dynamic Huffman trees: the counts, the
2197 * lengths of the bit length codes, the literal tree and the distance tree.
2198 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2200 local void send_all_trees(s, lcodes, dcodes, blcodes)
2202 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2204 int rank; /* index in bl_order */
2206 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2207 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2209 Tracev((stderr, "\nbl counts: "));
2210 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2211 send_bits(s, dcodes-1, 5);
2212 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2213 for (rank = 0; rank < blcodes; rank++) {
2214 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2215 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2217 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2219 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2220 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2222 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2223 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2226 /* ===========================================================================
2227 * Send a stored block
2229 local void ct_stored_block(s, buf, stored_len, eof)
2231 charf *buf; /* input block */
2232 ulg stored_len; /* length of input block */
2233 int eof; /* true if this is the last block for a file */
2235 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2236 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2237 s->compressed_len += (stored_len + 4) << 3;
2239 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2242 /* Send just the `stored block' type code without any length bytes or data.
2244 local void ct_stored_type_only(s)
2247 send_bits(s, (STORED_BLOCK << 1), 3);
2249 s->compressed_len = (s->compressed_len + 3) & ~7L;
2253 /* ===========================================================================
2254 * Send one empty static block to give enough lookahead for inflate.
2255 * This takes 10 bits, of which 7 may remain in the bit buffer.
2256 * The current inflate code requires 9 bits of lookahead. If the EOB
2257 * code for the previous block was coded on 5 bits or less, inflate
2258 * may have only 5+3 bits of lookahead to decode this EOB.
2259 * (There are no problems if the previous block is stored or fixed.)
2261 local void ct_align(s)
2264 send_bits(s, STATIC_TREES<<1, 3);
2265 send_code(s, END_BLOCK, static_ltree);
2266 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2268 /* Of the 10 bits for the empty block, we have already sent
2269 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2270 * block was thus its length plus what we have just sent.
2272 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2273 send_bits(s, STATIC_TREES<<1, 3);
2274 send_code(s, END_BLOCK, static_ltree);
2275 s->compressed_len += 10L;
2278 s->last_eob_len = 7;
2281 /* ===========================================================================
2282 * Determine the best encoding for the current block: dynamic trees, static
2283 * trees or store, and output the encoded block to the zip file. This function
2284 * returns the total compressed length for the file so far.
2286 local ulg ct_flush_block(s, buf, stored_len, flush)
2288 charf *buf; /* input block, or NULL if too old */
2289 ulg stored_len; /* length of input block */
2290 int flush; /* Z_FINISH if this is the last block for a file */
2292 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2293 int max_blindex; /* index of last bit length code of non zero freq */
2294 int eof = flush == Z_FINISH;
2296 ++s->blocks_in_packet;
2298 /* Check if the file is ascii or binary */
2299 if (s->data_type == UNKNOWN) set_data_type(s);
2301 /* Construct the literal and distance trees */
2302 build_tree(s, (tree_desc *)(&(s->l_desc)));
2303 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2306 build_tree(s, (tree_desc *)(&(s->d_desc)));
2307 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2309 /* At this point, opt_len and static_len are the total bit lengths of
2310 * the compressed block data, excluding the tree representations.
2313 /* Build the bit length tree for the above two trees, and get the index
2314 * in bl_order of the last bit length code to send.
2316 max_blindex = build_bl_tree(s);
2318 /* Determine the best encoding. Compute first the block length in bytes */
2319 opt_lenb = (s->opt_len+3+7)>>3;
2320 static_lenb = (s->static_len+3+7)>>3;
2322 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2323 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2326 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2328 /* If compression failed and this is the first and last block,
2329 * and if the .zip file can be seeked (to rewrite the local header),
2330 * the whole file is transformed into a stored file:
2332 #ifdef STORED_FILE_OK
2333 # ifdef FORCE_STORED_FILE
2334 if (eof && compressed_len == 0L) /* force stored file */
2336 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2339 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2340 if (buf == (charf*)0) error ("block vanished");
2342 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2343 s->compressed_len = stored_len << 3;
2346 #endif /* STORED_FILE_OK */
2348 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
2349 * compression, and this block contains all the data since the last
2350 * time we used Z_PACKET_FLUSH, then just omit this block completely
2353 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
2354 && opt_lenb > stored_len - s->minCompr) {
2355 s->blocks_in_packet = 0;
2356 /* output nothing */
2360 if (buf != (char*)0) /* force stored block */
2362 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2363 /* 4: two words for the lengths */
2366 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2367 * Otherwise we can't have processed more than WSIZE input bytes since
2368 * the last block flush, because compression would have been
2369 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2370 * transform a block into a stored block.
2372 ct_stored_block(s, buf, stored_len, eof);
2376 if (static_lenb >= 0) /* force static trees */
2378 if (static_lenb == opt_lenb)
2381 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2382 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2383 s->compressed_len += 3 + s->static_len;
2385 send_bits(s, (DYN_TREES<<1)+eof, 3);
2386 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2388 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2389 s->compressed_len += 3 + s->opt_len;
2391 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2396 s->compressed_len += 7; /* align on byte boundary */
2398 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2399 s->compressed_len-7*eof));
2401 return s->compressed_len >> 3;
2404 /* ===========================================================================
2405 * Save the match info and tally the frequency counts. Return true if
2406 * the current block must be flushed.
2408 local int ct_tally (s, dist, lc)
2410 int dist; /* distance of matched string */
2411 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2413 s->d_buf[s->last_lit] = (ush)dist;
2414 s->l_buf[s->last_lit++] = (uch)lc;
2416 /* lc is the unmatched char */
2417 s->dyn_ltree[lc].Freq++;
2420 /* Here, lc is the match length - MIN_MATCH */
2421 dist--; /* dist = match distance - 1 */
2422 Assert((ush)dist < (ush)MAX_DIST(s) &&
2423 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2424 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2426 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2427 s->dyn_dtree[d_code(dist)].Freq++;
2430 /* Try to guess if it is profitable to stop the current block here */
2431 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2432 /* Compute an upper bound for the compressed length */
2433 ulg out_length = (ulg)s->last_lit*8L;
2434 ulg in_length = (ulg)s->strstart - s->block_start;
2436 for (dcode = 0; dcode < D_CODES; dcode++) {
2437 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2438 (5L+extra_dbits[dcode]);
2441 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2442 s->last_lit, in_length, out_length,
2443 100L - out_length*100L/in_length));
2444 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2446 return (s->last_lit == s->lit_bufsize-1);
2447 /* We avoid equality with lit_bufsize because of wraparound at 64K
2448 * on 16 bit machines and because stored blocks are restricted to
2453 /* ===========================================================================
2454 * Send the block data compressed using the given Huffman trees
2456 local void compress_block(s, ltree, dtree)
2458 ct_data *ltree; /* literal tree */
2459 ct_data *dtree; /* distance tree */
2461 unsigned dist; /* distance of matched string */
2462 int lc; /* match length or unmatched char (if dist == 0) */
2463 unsigned lx = 0; /* running index in l_buf */
2464 unsigned code; /* the code to send */
2465 int extra; /* number of extra bits to send */
2467 if (s->last_lit != 0) do {
2468 dist = s->d_buf[lx];
2469 lc = s->l_buf[lx++];
2471 send_code(s, lc, ltree); /* send a literal byte */
2472 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2474 /* Here, lc is the match length - MIN_MATCH */
2475 code = length_code[lc];
2476 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2477 extra = extra_lbits[code];
2479 lc -= base_length[code];
2480 send_bits(s, lc, extra); /* send the extra length bits */
2482 dist--; /* dist is now the match distance - 1 */
2483 code = d_code(dist);
2484 Assert (code < D_CODES, "bad d_code");
2486 send_code(s, code, dtree); /* send the distance code */
2487 extra = extra_dbits[code];
2489 dist -= base_dist[code];
2490 send_bits(s, dist, extra); /* send the extra distance bits */
2492 } /* literal or match pair ? */
2494 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2495 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2497 } while (lx < s->last_lit);
2499 send_code(s, END_BLOCK, ltree);
2500 s->last_eob_len = ltree[END_BLOCK].Len;
2503 /* ===========================================================================
2504 * Set the data type to ASCII or BINARY, using a crude approximation:
2505 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2506 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2507 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2509 local void set_data_type(s)
2513 unsigned ascii_freq = 0;
2514 unsigned bin_freq = 0;
2515 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2516 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2517 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2518 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2521 /* ===========================================================================
2522 * Reverse the first len bits of a code, using straightforward code (a faster
2523 * method would use a table)
2524 * IN assertion: 1 <= len <= 15
2526 local unsigned bi_reverse(code, len)
2527 unsigned code; /* the value to invert */
2528 int len; /* its bit length */
2530 register unsigned res = 0;
2533 code >>= 1, res <<= 1;
2534 } while (--len > 0);
2538 /* ===========================================================================
2539 * Flush the bit buffer, keeping at most 7 bits in it.
2541 local void bi_flush(s)
2544 if (s->bi_valid == 16) {
2545 put_short(s, s->bi_buf);
2548 } else if (s->bi_valid >= 8) {
2549 put_byte(s, (Byte)s->bi_buf);
2555 /* ===========================================================================
2556 * Flush the bit buffer and align the output on a byte boundary
2558 local void bi_windup(s)
2561 if (s->bi_valid > 8) {
2562 put_short(s, s->bi_buf);
2563 } else if (s->bi_valid > 0) {
2564 put_byte(s, (Byte)s->bi_buf);
2569 s->bits_sent = (s->bits_sent+7) & ~7;
2573 /* ===========================================================================
2574 * Copy a stored block, storing first the length and its
2575 * one's complement if requested.
2577 local void copy_block(s, buf, len, header)
2579 charf *buf; /* the input data */
2580 unsigned len; /* its length */
2581 int header; /* true if block header must be written */
2583 bi_windup(s); /* align on byte boundary */
2584 s->last_eob_len = 8; /* enough lookahead for inflate */
2587 put_short(s, (ush)len);
2588 put_short(s, (ush)~len);
2590 s->bits_sent += 2*16;
2594 s->bits_sent += (ulg)len<<3;
2597 put_byte(s, *buf++);
2603 /* infblock.h -- header to use infblock.c
2604 * Copyright (C) 1995 Mark Adler
2605 * For conditions of distribution and use, see copyright notice in zlib.h
2608 /* WARNING: this file should *not* be used by applications. It is
2609 part of the implementation of the compression library and is
2610 subject to change. Applications should only use zlib.h.
2613 struct inflate_blocks_state;
2614 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2616 local inflate_blocks_statef * inflate_blocks_new OF((
2618 check_func c, /* check function */
2619 uInt w)); /* window size */
2621 local int inflate_blocks OF((
2622 inflate_blocks_statef *,
2624 int)); /* initial return code */
2626 local void inflate_blocks_reset OF((
2627 inflate_blocks_statef *,
2629 uLongf *)); /* check value on output */
2631 local int inflate_blocks_free OF((
2632 inflate_blocks_statef *,
2634 uLongf *)); /* check value on output */
2636 local int inflate_addhistory OF((
2637 inflate_blocks_statef *,
2640 local int inflate_packet_flush OF((
2641 inflate_blocks_statef *));
2644 /* inftrees.h -- header to use inftrees.c
2645 * Copyright (C) 1995 Mark Adler
2646 * For conditions of distribution and use, see copyright notice in zlib.h
2649 /* WARNING: this file should *not* be used by applications. It is
2650 part of the implementation of the compression library and is
2651 subject to change. Applications should only use zlib.h.
2654 /* Huffman code lookup table entry--this entry is four bytes for machines
2655 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2657 typedef struct inflate_huft_s FAR inflate_huft;
2659 struct inflate_huft_s {
2662 Byte Exop; /* number of extra bits or operation */
2663 Byte Bits; /* number of bits in this code or subcode */
2665 uInt Nalloc; /* number of these allocated here */
2666 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2667 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2669 uInt Base; /* literal, length base, or distance base */
2670 inflate_huft *Next; /* pointer to next level of table */
2675 local uInt inflate_hufts;
2678 local int inflate_trees_bits OF((
2679 uIntf *, /* 19 code lengths */
2680 uIntf *, /* bits tree desired/actual depth */
2681 inflate_huft * FAR *, /* bits tree result */
2682 z_stream *)); /* for zalloc, zfree functions */
2684 local int inflate_trees_dynamic OF((
2685 uInt, /* number of literal/length codes */
2686 uInt, /* number of distance codes */
2687 uIntf *, /* that many (total) code lengths */
2688 uIntf *, /* literal desired/actual bit depth */
2689 uIntf *, /* distance desired/actual bit depth */
2690 inflate_huft * FAR *, /* literal/length tree result */
2691 inflate_huft * FAR *, /* distance tree result */
2692 z_stream *)); /* for zalloc, zfree functions */
2694 local int inflate_trees_fixed OF((
2695 uIntf *, /* literal desired/actual bit depth */
2696 uIntf *, /* distance desired/actual bit depth */
2697 inflate_huft * FAR *, /* literal/length tree result */
2698 inflate_huft * FAR *)); /* distance tree result */
2700 local int inflate_trees_free OF((
2701 inflate_huft *, /* tables to free */
2702 z_stream *)); /* for zfree function */
2706 /* infcodes.h -- header to use infcodes.c
2707 * Copyright (C) 1995 Mark Adler
2708 * For conditions of distribution and use, see copyright notice in zlib.h
2711 /* WARNING: this file should *not* be used by applications. It is
2712 part of the implementation of the compression library and is
2713 subject to change. Applications should only use zlib.h.
2716 struct inflate_codes_state;
2717 typedef struct inflate_codes_state FAR inflate_codes_statef;
2719 local inflate_codes_statef *inflate_codes_new OF((
2721 inflate_huft *, inflate_huft *,
2724 local int inflate_codes OF((
2725 inflate_blocks_statef *,
2729 local void inflate_codes_free OF((
2730 inflate_codes_statef *,
2735 /* inflate.c -- zlib interface to inflate modules
2736 * Copyright (C) 1995 Mark Adler
2737 * For conditions of distribution and use, see copyright notice in zlib.h
2740 /* inflate private state */
2741 struct internal_state {
2745 METHOD, /* waiting for method byte */
2746 FLAG, /* waiting for flag byte */
2747 BLOCKS, /* decompressing blocks */
2748 CHECK4, /* four check bytes to go */
2749 CHECK3, /* three check bytes to go */
2750 CHECK2, /* two check bytes to go */
2751 CHECK1, /* one check byte to go */
2752 DONE, /* finished check, done */
2753 BAD} /* got an error--stay here */
2754 mode; /* current inflate mode */
2756 /* mode dependent information */
2758 uInt method; /* if FLAGS, method byte */
2760 uLong was; /* computed check value */
2761 uLong need; /* stream check value */
2762 } check; /* if CHECK, check values to compare */
2763 uInt marker; /* if BAD, inflateSync's marker bytes count */
2764 } sub; /* submode */
2766 /* mode independent information */
2767 int nowrap; /* flag for no wrapper */
2768 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2769 inflate_blocks_statef
2770 *blocks; /* current inflate_blocks state */
2780 if (z == Z_NULL || z->state == Z_NULL)
2781 return Z_STREAM_ERROR;
2782 z->total_in = z->total_out = 0;
2784 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2785 inflate_blocks_reset(z->state->blocks, z, &c);
2786 Trace((stderr, "inflate: reset\n"));
2796 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2797 return Z_STREAM_ERROR;
2798 if (z->state->blocks != Z_NULL)
2799 inflate_blocks_free(z->state->blocks, z, &c);
2800 ZFREE(z, z->state, sizeof(struct internal_state));
2802 Trace((stderr, "inflate: end\n"));
2807 int inflateInit2(z, w)
2811 /* initialize state */
2813 return Z_STREAM_ERROR;
2814 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2815 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2816 if ((z->state = (struct internal_state FAR *)
2817 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2819 z->state->blocks = Z_NULL;
2821 /* handle undocumented nowrap option (no zlib header or check) */
2822 z->state->nowrap = 0;
2826 z->state->nowrap = 1;
2829 /* set window size */
2830 if (w < 8 || w > 15)
2833 return Z_STREAM_ERROR;
2835 z->state->wbits = (uInt)w;
2837 /* create inflate_blocks state */
2838 if ((z->state->blocks =
2839 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2845 Trace((stderr, "inflate: allocated\n"));
2856 return inflateInit2(z, DEF_WBITS);
2860 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2861 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2870 if (z == Z_NULL || z->next_in == Z_NULL)
2871 return Z_STREAM_ERROR;
2873 while (1) switch (z->state->mode)
2877 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2879 z->state->mode = BAD;
2880 z->msg = "unknown compression method";
2881 z->state->sub.marker = 5; /* can't try inflateSync */
2884 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2886 z->state->mode = BAD;
2887 z->msg = "invalid window size";
2888 z->state->sub.marker = 5; /* can't try inflateSync */
2891 z->state->mode = FLAG;
2894 if ((b = NEXTBYTE) & 0x20)
2896 z->state->mode = BAD;
2897 z->msg = "invalid reserved bit";
2898 z->state->sub.marker = 5; /* can't try inflateSync */
2901 if (((z->state->sub.method << 8) + b) % 31)
2903 z->state->mode = BAD;
2904 z->msg = "incorrect header check";
2905 z->state->sub.marker = 5; /* can't try inflateSync */
2908 Trace((stderr, "inflate: zlib header ok\n"));
2909 z->state->mode = BLOCKS;
2911 r = inflate_blocks(z->state->blocks, z, r);
2912 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2913 r = inflate_packet_flush(z->state->blocks);
2914 if (r == Z_DATA_ERROR)
2916 z->state->mode = BAD;
2917 z->state->sub.marker = 0; /* can try inflateSync */
2920 if (r != Z_STREAM_END)
2923 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2924 if (z->state->nowrap)
2926 z->state->mode = DONE;
2929 z->state->mode = CHECK4;
2932 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2933 z->state->mode = CHECK3;
2936 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2937 z->state->mode = CHECK2;
2940 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2941 z->state->mode = CHECK1;
2944 z->state->sub.check.need += (uLong)NEXTBYTE;
2946 if (z->state->sub.check.was != z->state->sub.check.need)
2948 z->state->mode = BAD;
2949 z->msg = "incorrect data check";
2950 z->state->sub.marker = 5; /* can't try inflateSync */
2953 Trace((stderr, "inflate: zlib check ok\n"));
2954 z->state->mode = DONE;
2956 return Z_STREAM_END;
2958 return Z_DATA_ERROR;
2960 return Z_STREAM_ERROR;
2964 if (f != Z_PACKET_FLUSH)
2966 z->state->mode = BAD;
2967 z->state->sub.marker = 0; /* can try inflateSync */
2968 return Z_DATA_ERROR;
2972 * This subroutine adds the data at next_in/avail_in to the output history
2973 * without performing any output. The output buffer must be "caught up";
2974 * i.e. no pending output (hence s->read equals s->write), and the state must
2975 * be BLOCKS (i.e. we should be willing to see the start of a series of
2976 * BLOCKS). On exit, the output will also be caught up, and the checksum
2977 * will have been updated if need be.
2980 int inflateIncomp(z)
2983 if (z->state->mode != BLOCKS)
2984 return Z_DATA_ERROR;
2985 return inflate_addhistory(z->state->blocks, z);
2992 uInt n; /* number of bytes to look at */
2993 Bytef *p; /* pointer to bytes */
2994 uInt m; /* number of marker bytes found in a row */
2995 uLong r, w; /* temporaries to save total_in and total_out */
2998 if (z == Z_NULL || z->state == Z_NULL)
2999 return Z_STREAM_ERROR;
3000 if (z->state->mode != BAD)
3002 z->state->mode = BAD;
3003 z->state->sub.marker = 0;
3005 if ((n = z->avail_in) == 0)
3008 m = z->state->sub.marker;
3013 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3023 z->total_in += p - z->next_in;
3026 z->state->sub.marker = m;
3028 /* return no joy or set up to restart on a new block */
3030 return Z_DATA_ERROR;
3031 r = z->total_in; w = z->total_out;
3033 z->total_in = r; z->total_out = w;
3034 z->state->mode = BLOCKS;
3042 /* infutil.h -- types and macros common to blocks and codes
3043 * Copyright (C) 1995 Mark Adler
3044 * For conditions of distribution and use, see copyright notice in zlib.h
3047 /* WARNING: this file should *not* be used by applications. It is
3048 part of the implementation of the compression library and is
3049 subject to change. Applications should only use zlib.h.
3052 /* inflate blocks semi-private state */
3053 struct inflate_blocks_state {
3057 TYPE, /* get type bits (3, including end bit) */
3058 LENS, /* get lengths for stored */
3059 STORED, /* processing stored block */
3060 TABLE, /* get table lengths */
3061 BTREE, /* get bit lengths tree for a dynamic block */
3062 DTREE, /* get length, distance trees for a dynamic block */
3063 CODES, /* processing fixed or dynamic block */
3064 DRY, /* output remaining window bytes */
3065 DONEB, /* finished last block, done */
3066 BADB} /* got a data error--stuck here */
3067 mode; /* current inflate_block mode */
3069 /* mode dependent information */
3071 uInt left; /* if STORED, bytes left to copy */
3073 uInt table; /* table lengths (14 bits) */
3074 uInt index; /* index into blens (or border) */
3075 uIntf *blens; /* bit lengths of codes */
3076 uInt bb; /* bit length tree depth */
3077 inflate_huft *tb; /* bit length decoding tree */
3078 int nblens; /* # elements allocated at blens */
3079 } trees; /* if DTREE, decoding info for trees */
3081 inflate_huft *tl, *td; /* trees to free */
3082 inflate_codes_statef
3084 } decode; /* if CODES, current state */
3085 } sub; /* submode */
3086 uInt last; /* true if this block is the last block */
3088 /* mode independent information */
3089 uInt bitk; /* bits in bit buffer */
3090 uLong bitb; /* bit buffer */
3091 Bytef *window; /* sliding window */
3092 Bytef *end; /* one byte after sliding window */
3093 Bytef *read; /* window read pointer */
3094 Bytef *write; /* window write pointer */
3095 check_func checkfn; /* check function */
3096 uLong check; /* check on output */
3101 /* defines for inflate input/output */
3102 /* update pointers and return */
3103 #define UPDBITS {s->bitb=b;s->bitk=k;}
3104 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3105 #define UPDOUT {s->write=q;}
3106 #define UPDATE {UPDBITS UPDIN UPDOUT}
3107 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3108 /* get bytes and bits */
3109 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3110 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3111 #define NEXTBYTE (n--,*p++)
3112 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3113 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3115 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3116 #define LOADOUT {q=s->write;m=WAVAIL;}
3117 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3118 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3119 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3120 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3121 /* load local pointers */
3122 #define LOAD {LOADIN LOADOUT}
3124 /* And'ing with mask[n] masks the lower n bits */
3125 local uInt inflate_mask[] = {
3127 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3128 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3131 /* copy as much as possible from the sliding window to the output area */
3132 local int inflate_flush OF((
3133 inflate_blocks_statef *,
3138 /* inffast.h -- header to use inffast.c
3139 * Copyright (C) 1995 Mark Adler
3140 * For conditions of distribution and use, see copyright notice in zlib.h
3143 /* WARNING: this file should *not* be used by applications. It is
3144 part of the implementation of the compression library and is
3145 subject to change. Applications should only use zlib.h.
3148 local int inflate_fast OF((
3153 inflate_blocks_statef *,
3158 /* infblock.c -- interpret and process block types to last block
3159 * Copyright (C) 1995 Mark Adler
3160 * For conditions of distribution and use, see copyright notice in zlib.h
3163 /* Table for deflate from PKZIP's appnote.txt. */
3164 local uInt border[] = { /* Order of the bit length code lengths */
3165 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3168 Notes beyond the 1.93a appnote.txt:
3170 1. Distance pointers never point before the beginning of the output
3172 2. Distance pointers can point back across blocks, up to 32k away.
3173 3. There is an implied maximum of 7 bits for the bit length table and
3174 15 bits for the actual data.
3175 4. If only one code exists, then it is encoded using one bit. (Zero
3176 would be more efficient, but perhaps a little confusing.) If two
3177 codes exist, they are coded using one bit each (0 and 1).
3178 5. There is no way of sending zero distance codes--a dummy must be
3179 sent if there are none. (History: a pre 2.0 version of PKZIP would
3180 store blocks with no distance codes, but this was discovered to be
3181 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3182 zero distance codes, which is sent as one code of zero bits in
3184 6. There are up to 286 literal/length codes. Code 256 represents the
3185 end-of-block. Note however that the static length tree defines
3186 288 codes just to fill out the Huffman codes. Codes 286 and 287
3187 cannot be used though, since there is no length base or extra bits
3188 defined for them. Similarily, there are up to 30 distance codes.
3189 However, static trees define 32 codes (all 5 bits) to fill out the
3190 Huffman codes, but the last two had better not show up in the data.
3191 7. Unzip can check dynamic Huffman blocks for complete code sets.
3192 The exception is that a single code would not be complete (see #4).
3193 8. The five bits following the block type is really the number of
3194 literal codes sent minus 257.
3195 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3196 (1+6+6). Therefore, to output three times the length, you output
3197 three codes (1+1+1), whereas to output four times the same length,
3198 you only need two codes (1+3). Hmm.
3199 10. In the tree reconstruction algorithm, Code = Code + Increment
3200 only if BitLength(i) is not zero. (Pretty obvious.)
3201 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3202 12. Note: length code 284 can represent 227-258, but length code 285
3203 really is 258. The last length deserves its own, short code
3204 since it gets used a lot in very redundant files. The length
3205 258 is special since 258 - 3 (the min match length) is 255.
3206 13. The literal/length and distance code bit lengths are read as a
3207 single stream of lengths. It is possible (and advantageous) for
3208 a repeat code (16, 17, or 18) to go across the boundary between
3209 the two sets of lengths.
3213 local void inflate_blocks_reset(s, z, c)
3214 inflate_blocks_statef *s;
3218 if (s->checkfn != Z_NULL)
3220 if (s->mode == BTREE || s->mode == DTREE)
3221 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3222 if (s->mode == CODES)
3224 inflate_codes_free(s->sub.decode.codes, z);
3225 inflate_trees_free(s->sub.decode.td, z);
3226 inflate_trees_free(s->sub.decode.tl, z);
3231 s->read = s->write = s->window;
3232 if (s->checkfn != Z_NULL)
3233 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3234 Trace((stderr, "inflate: blocks reset\n"));
3238 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
3243 inflate_blocks_statef *s;
3245 if ((s = (inflate_blocks_statef *)ZALLOC
3246 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3248 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3250 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3253 s->end = s->window + w;
3256 Trace((stderr, "inflate: blocks allocated\n"));
3257 inflate_blocks_reset(s, z, &s->check);
3262 local int inflate_blocks(s, z, r)
3263 inflate_blocks_statef *s;
3267 uInt t; /* temporary storage */
3268 uLong b; /* bit buffer */
3269 uInt k; /* bits in bit buffer */
3270 Bytef *p; /* input data pointer */
3271 uInt n; /* bytes available there */
3272 Bytef *q; /* output window write pointer */
3273 uInt m; /* bytes to end of window or read pointer */
3275 /* copy input/output information to locals (UPDATE macro restores) */
3278 /* process input based on current state */
3279 while (1) switch (s->mode)
3287 case 0: /* stored */
3288 Trace((stderr, "inflate: stored block%s\n",
3289 s->last ? " (last)" : ""));
3291 t = k & 7; /* go to byte boundary */
3293 s->mode = LENS; /* get length of stored block */
3296 Trace((stderr, "inflate: fixed codes block%s\n",
3297 s->last ? " (last)" : ""));
3300 inflate_huft *tl, *td;
3302 inflate_trees_fixed(&bl, &bd, &tl, &td);
3303 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3304 if (s->sub.decode.codes == Z_NULL)
3309 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3310 s->sub.decode.td = Z_NULL;
3315 case 2: /* dynamic */
3316 Trace((stderr, "inflate: dynamic codes block%s\n",
3317 s->last ? " (last)" : ""));
3321 case 3: /* illegal */
3324 z->msg = "invalid block type";
3331 if (((~b) >> 16) != (b & 0xffff))
3334 z->msg = "invalid stored block lengths";
3338 s->sub.left = (uInt)b & 0xffff;
3339 b = k = 0; /* dump bits */
3340 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3341 s->mode = s->sub.left ? STORED : TYPE;
3353 if ((s->sub.left -= t) != 0)
3355 Tracev((stderr, "inflate: stored end, %lu total out\n",
3356 z->total_out + (q >= s->read ? q - s->read :
3357 (s->end - s->read) + (q - s->window))));
3358 s->mode = s->last ? DRY : TYPE;
3362 s->sub.trees.table = t = (uInt)b & 0x3fff;
3363 #ifndef PKZIP_BUG_WORKAROUND
3364 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3367 z->msg = "too many length or distance symbols";
3372 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3375 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3380 s->sub.trees.nblens = t;
3382 s->sub.trees.index = 0;
3383 Tracev((stderr, "inflate: table sizes ok\n"));
3386 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3389 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3392 while (s->sub.trees.index < 19)
3393 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3394 s->sub.trees.bb = 7;
3395 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3396 &s->sub.trees.tb, z);
3400 if (r == Z_DATA_ERROR)
3404 s->sub.trees.index = 0;
3405 Tracev((stderr, "inflate: bits tree ok\n"));
3408 while (t = s->sub.trees.table,
3409 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3414 t = s->sub.trees.bb;
3416 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3417 t = h->word.what.Bits;
3422 s->sub.trees.blens[s->sub.trees.index++] = c;
3424 else /* c == 16..18 */
3426 i = c == 18 ? 7 : c - 14;
3427 j = c == 18 ? 11 : 3;
3430 j += (uInt)b & inflate_mask[i];
3432 i = s->sub.trees.index;
3433 t = s->sub.trees.table;
3434 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3438 z->msg = "invalid bit length repeat";
3442 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3444 s->sub.trees.blens[i++] = c;
3446 s->sub.trees.index = i;
3449 inflate_trees_free(s->sub.trees.tb, z);
3450 s->sub.trees.tb = Z_NULL;
3453 inflate_huft *tl, *td;
3454 inflate_codes_statef *c;
3456 bl = 9; /* must be <= 9 for lookahead assumptions */
3457 bd = 6; /* must be <= 9 for lookahead assumptions */
3458 t = s->sub.trees.table;
3459 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3460 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3463 if (t == (uInt)Z_DATA_ERROR)
3468 Tracev((stderr, "inflate: trees ok\n"));
3469 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3471 inflate_trees_free(td, z);
3472 inflate_trees_free(tl, z);
3476 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3477 s->sub.decode.codes = c;
3478 s->sub.decode.tl = tl;
3479 s->sub.decode.td = td;
3484 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3485 return inflate_flush(s, z, r);
3487 inflate_codes_free(s->sub.decode.codes, z);
3488 inflate_trees_free(s->sub.decode.td, z);
3489 inflate_trees_free(s->sub.decode.tl, z);
3491 Tracev((stderr, "inflate: codes end, %lu total out\n",
3492 z->total_out + (q >= s->read ? q - s->read :
3493 (s->end - s->read) + (q - s->window))));
3499 if (k > 7) /* return unused byte, if any */
3501 Assert(k < 16, "inflate_codes grabbed too many bytes")
3504 p--; /* can always return one */
3509 if (s->read != s->write)
3525 local int inflate_blocks_free(s, z, c)
3526 inflate_blocks_statef *s;
3530 inflate_blocks_reset(s, z, c);
3531 ZFREE(z, s->window, s->end - s->window);
3532 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3533 Trace((stderr, "inflate: blocks freed\n"));
3538 * This subroutine adds the data at next_in/avail_in to the output history
3539 * without performing any output. The output buffer must be "caught up";
3540 * i.e. no pending output (hence s->read equals s->write), and the state must
3541 * be BLOCKS (i.e. we should be willing to see the start of a series of
3542 * BLOCKS). On exit, the output will also be caught up, and the checksum
3543 * will have been updated if need be.
3545 local int inflate_addhistory(s, z)
3546 inflate_blocks_statef *s;
3549 uLong b; /* bit buffer */ /* NOT USED HERE */
3550 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3551 uInt t; /* temporary storage */
3552 Bytef *p; /* input data pointer */
3553 uInt n; /* bytes available there */
3554 Bytef *q; /* output window write pointer */
3555 uInt m; /* bytes to end of window or read pointer */
3557 if (s->read != s->write)
3558 return Z_STREAM_ERROR;
3559 if (s->mode != TYPE)
3560 return Z_DATA_ERROR;
3562 /* we're ready to rock */
3564 /* while there is input ready, copy to output buffer, moving
3565 * pointers as needed.
3568 t = n; /* how many to do */
3569 /* is there room until end of buffer? */
3571 /* update check information */
3572 if (s->checkfn != Z_NULL)
3573 s->check = (*s->checkfn)(s->check, q, t);
3579 s->read = q; /* drag read pointer forward */
3580 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
3582 s->read = q = s->window;
3592 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3593 * a `stored' block type value but not the (zero) length bytes.
3595 local int inflate_packet_flush(s)
3596 inflate_blocks_statef *s;
3598 if (s->mode != LENS)
3599 return Z_DATA_ERROR;
3606 /* inftrees.c -- generate Huffman trees for efficient decoding
3607 * Copyright (C) 1995 Mark Adler
3608 * For conditions of distribution and use, see copyright notice in zlib.h
3611 /* simplify the use of the inflate_huft type with some defines */
3612 #define base more.Base
3613 #define next more.Next
3614 #define exop word.what.Exop
3615 #define bits word.what.Bits
3618 local int huft_build OF((
3619 uIntf *, /* code lengths in bits */
3620 uInt, /* number of codes */
3621 uInt, /* number of "simple" codes */
3622 uIntf *, /* list of base values for non-simple codes */
3623 uIntf *, /* list of extra bits for non-simple codes */
3624 inflate_huft * FAR*,/* result: starting table */
3625 uIntf *, /* maximum lookup bits (returns actual) */
3626 z_stream *)); /* for zalloc function */
3628 local voidpf falloc OF((
3629 voidpf, /* opaque pointer (not used) */
3630 uInt, /* number of items */
3631 uInt)); /* size of item */
3633 local void ffree OF((
3634 voidpf q, /* opaque pointer (not used) */
3635 voidpf p, /* what to free (not used) */
3636 uInt n)); /* number of bytes (not used) */
3638 /* Tables for deflate from PKZIP's appnote.txt. */
3639 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3640 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3641 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3642 /* actually lengths - 2; also see note #13 above about 258 */
3643 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3644 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3645 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3646 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3647 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3648 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3649 8193, 12289, 16385, 24577};
3650 local uInt cpdext[] = { /* Extra bits for distance codes */
3651 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3652 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3656 Huffman code decoding is performed using a multi-level table lookup.
3657 The fastest way to decode is to simply build a lookup table whose
3658 size is determined by the longest code. However, the time it takes
3659 to build this table can also be a factor if the data being decoded
3660 is not very long. The most common codes are necessarily the
3661 shortest codes, so those codes dominate the decoding time, and hence
3662 the speed. The idea is you can have a shorter table that decodes the
3663 shorter, more probable codes, and then point to subsidiary tables for
3664 the longer codes. The time it costs to decode the longer codes is
3665 then traded against the time it takes to make longer tables.
3667 This results of this trade are in the variables lbits and dbits
3668 below. lbits is the number of bits the first level table for literal/
3669 length codes can decode in one step, and dbits is the same thing for
3670 the distance codes. Subsequent tables are also less than or equal to
3671 those sizes. These values may be adjusted either when all of the
3672 codes are shorter than that, in which case the longest code length in
3673 bits is used, or when the shortest code is *longer* than the requested
3674 table size, in which case the length of the shortest code in bits is
3677 There are two different values for the two tables, since they code a
3678 different number of possibilities each. The literal/length table
3679 codes 286 possible values, or in a flat code, a little over eight
3680 bits. The distance table codes 30 possible values, or a little less
3681 than five bits, flat. The optimum values for speed end up being
3682 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3683 The optimum values may differ though from machine to machine, and
3684 possibly even between compilers. Your mileage may vary.
3688 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3689 #define BMAX 15 /* maximum bit length of any code */
3690 #define N_MAX 288 /* maximum number of codes in any set */
3696 local int huft_build(b, n, s, d, e, t, m, zs)
3697 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3698 uInt n; /* number of codes (assumed <= N_MAX) */
3699 uInt s; /* number of simple-valued codes (0..s-1) */
3700 uIntf *d; /* list of base values for non-simple codes */
3701 uIntf *e; /* list of extra bits for non-simple codes */
3702 inflate_huft * FAR *t; /* result: starting table */
3703 uIntf *m; /* maximum lookup bits, returns actual */
3704 z_stream *zs; /* for zalloc function */
3705 /* Given a list of code lengths and a maximum table size, make a set of
3706 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3707 if the given code set is incomplete (the tables are still built in this
3708 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3709 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3712 uInt a; /* counter for codes of length k */
3713 uInt c[BMAX+1]; /* bit length count table */
3714 uInt f; /* i repeats in table every f entries */
3715 int g; /* maximum code length */
3716 int h; /* table level */
3717 register uInt i; /* counter, current code */
3718 register uInt j; /* counter */
3719 register int k; /* number of bits in current code */
3720 int l; /* bits per table (returned in m) */
3721 register uIntf *p; /* pointer into c[], b[], or v[] */
3722 inflate_huft *q; /* points to current table */
3723 struct inflate_huft_s r; /* table entry for structure assignment */
3724 inflate_huft *u[BMAX]; /* table stack */
3725 uInt v[N_MAX]; /* values in order of bit length */
3726 register int w; /* bits before this table == (l * h) */
3727 uInt x[BMAX+1]; /* bit offsets, then code stack */
3728 uIntf *xp; /* pointer into x */
3729 int y; /* number of dummy codes added */
3730 uInt z; /* number of entries in current table */
3733 /* Generate counts for each bit length */
3735 #define C0 *p++ = 0;
3736 #define C2 C0 C0 C0 C0
3737 #define C4 C2 C2 C2 C2
3738 C4 /* clear c[]--assume BMAX+1 is 16 */
3741 c[*p++]++; /* assume all entries <= BMAX */
3743 if (c[0] == n) /* null input--all zero length codes */
3745 *t = (inflate_huft *)Z_NULL;
3751 /* Find minimum and maximum length, bound *m by those */
3753 for (j = 1; j <= BMAX; j++)
3756 k = j; /* minimum code length */
3759 for (i = BMAX; i; i--)
3762 g = i; /* maximum code length */
3768 /* Adjust last length count to fill out codes, if needed */
3769 for (y = 1 << j; j < i; j++, y <<= 1)
3770 if ((y -= c[j]) < 0)
3771 return Z_DATA_ERROR;
3772 if ((y -= c[i]) < 0)
3773 return Z_DATA_ERROR;
3777 /* Generate starting offsets into the value table for each length */
3779 p = c + 1; xp = x + 2;
3780 while (--i) { /* note that i == g from above */
3781 *xp++ = (j += *p++);
3785 /* Make a table of values in order of bit lengths */
3788 if ((j = *p++) != 0)
3793 /* Generate the Huffman codes and for each, make the table entries */
3794 x[0] = i = 0; /* first Huffman code is zero */
3795 p = v; /* grab values in bit order */
3796 h = -1; /* no tables yet--level -1 */
3797 w = -l; /* bits decoded == (l * h) */
3798 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3799 q = (inflate_huft *)Z_NULL; /* ditto */
3802 /* go through the bit lengths (k already is bits in shortest code) */
3808 /* here i is the Huffman code of length k bits for value *p */
3809 /* make tables up to required level */
3813 w += l; /* previous table always l bits */
3815 /* compute minimum size table less than or equal to l bits */
3816 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3817 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3818 { /* too few codes for k-w bit table */
3819 f -= a + 1; /* deduct codes from patterns left */
3822 while (++j < z) /* try smaller tables up to z bits */
3824 if ((f <<= 1) <= *++xp)
3825 break; /* enough codes to use up j bits */
3826 f -= *xp; /* else deduct codes from patterns */
3829 z = 1 << j; /* table entries for j-bit table */
3831 /* allocate and link in new table */
3832 if ((q = (inflate_huft *)ZALLOC
3833 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3836 inflate_trees_free(u[0], zs);
3837 return Z_MEM_ERROR; /* not enough memory */
3839 q->word.Nalloc = z + 1;
3841 inflate_hufts += z + 1;
3843 *t = q + 1; /* link to list for huft_free() */
3844 *(t = &(q->next)) = Z_NULL;
3845 u[h] = ++q; /* table starts after link */
3847 /* connect to last table, if there is one */
3850 x[h] = i; /* save pattern for backing up */
3851 r.bits = (Byte)l; /* bits to dump before this table */
3852 r.exop = (Byte)j; /* bits in this table */
3853 r.next = q; /* pointer to this table */
3854 j = i >> (w - l); /* (get around Turbo C bug) */
3855 u[h-1][j] = r; /* connect to last table */
3859 /* set up table entry in r */
3860 r.bits = (Byte)(k - w);
3862 r.exop = 128 + 64; /* out of values--invalid code */
3865 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3866 r.base = *p++; /* simple code is just the value */
3870 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3871 r.base = d[*p++ - s];
3874 /* fill code-like entries with r */
3876 for (j = i >> w; j < z; j += f)
3879 /* backwards increment the k-bit code i */
3880 for (j = 1 << (k - 1); i & j; j >>= 1)
3884 /* backup over finished tables */
3885 while ((i & ((1 << w) - 1)) != x[h])
3887 h--; /* don't need to update q */
3894 /* Return Z_BUF_ERROR if we were given an incomplete table */
3895 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3899 local int inflate_trees_bits(c, bb, tb, z)
3900 uIntf *c; /* 19 code lengths */
3901 uIntf *bb; /* bits tree desired/actual depth */
3902 inflate_huft * FAR *tb; /* bits tree result */
3903 z_stream *z; /* for zfree function */
3907 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3908 if (r == Z_DATA_ERROR)
3909 z->msg = "oversubscribed dynamic bit lengths tree";
3910 else if (r == Z_BUF_ERROR)
3912 inflate_trees_free(*tb, z);
3913 z->msg = "incomplete dynamic bit lengths tree";
3920 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3921 uInt nl; /* number of literal/length codes */
3922 uInt nd; /* number of distance codes */
3923 uIntf *c; /* that many (total) code lengths */
3924 uIntf *bl; /* literal desired/actual bit depth */
3925 uIntf *bd; /* distance desired/actual bit depth */
3926 inflate_huft * FAR *tl; /* literal/length tree result */
3927 inflate_huft * FAR *td; /* distance tree result */
3928 z_stream *z; /* for zfree function */
3932 /* build literal/length tree */
3933 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3935 if (r == Z_DATA_ERROR)
3936 z->msg = "oversubscribed literal/length tree";
3937 else if (r == Z_BUF_ERROR)
3939 inflate_trees_free(*tl, z);
3940 z->msg = "incomplete literal/length tree";
3946 /* build distance tree */
3947 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3949 if (r == Z_DATA_ERROR)
3950 z->msg = "oversubscribed literal/length tree";
3951 else if (r == Z_BUF_ERROR) {
3952 #ifdef PKZIP_BUG_WORKAROUND
3956 inflate_trees_free(*td, z);
3957 z->msg = "incomplete literal/length tree";
3960 inflate_trees_free(*tl, z);
3970 /* build fixed tables only once--keep them here */
3971 local int fixed_lock = 0;
3972 local int fixed_built = 0;
3973 #define FIXEDH 530 /* number of hufts used by fixed tables */
3974 local uInt fixed_left = FIXEDH;
3975 local inflate_huft fixed_mem[FIXEDH];
3976 local uInt fixed_bl;
3977 local uInt fixed_bd;
3978 local inflate_huft *fixed_tl;
3979 local inflate_huft *fixed_td;
3982 local voidpf falloc(q, n, s)
3983 voidpf q; /* opaque pointer (not used) */
3984 uInt n; /* number of items */
3985 uInt s; /* size of item */
3987 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
3988 "inflate_trees falloc overflow");
3989 if (q) s++; /* to make some compilers happy */
3991 return (voidpf)(fixed_mem + fixed_left);
3995 local void ffree(q, p, n)
4000 Assert(0, "inflate_trees ffree called!");
4001 if (q) q = p; /* to make some compilers happy */
4005 local int inflate_trees_fixed(bl, bd, tl, td)
4006 uIntf *bl; /* literal desired/actual bit depth */
4007 uIntf *bd; /* distance desired/actual bit depth */
4008 inflate_huft * FAR *tl; /* literal/length tree result */
4009 inflate_huft * FAR *td; /* distance tree result */
4011 /* build fixed tables if not built already--lock out other instances */
4012 while (++fixed_lock > 1)
4016 int k; /* temporary variable */
4017 unsigned c[288]; /* length list for huft_build */
4018 z_stream z; /* for falloc function */
4020 /* set up fake z_stream for memory routines */
4026 for (k = 0; k < 144; k++)
4028 for (; k < 256; k++)
4030 for (; k < 280; k++)
4032 for (; k < 288; k++)
4035 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4037 /* distance table */
4038 for (k = 0; k < 30; k++)
4041 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4055 local int inflate_trees_free(t, z)
4056 inflate_huft *t; /* table to free */
4057 z_stream *z; /* for zfree function */
4058 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4059 list of the tables it made, with the links in a dummy first entry of
4062 register inflate_huft *p, *q;
4064 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4069 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4076 /* infcodes.c -- process literals and length/distance pairs
4077 * Copyright (C) 1995 Mark Adler
4078 * For conditions of distribution and use, see copyright notice in zlib.h
4081 /* simplify the use of the inflate_huft type with some defines */
4082 #define base more.Base
4083 #define next more.Next
4084 #define exop word.what.Exop
4085 #define bits word.what.Bits
4087 /* inflate codes private state */
4088 struct inflate_codes_state {
4091 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4092 START, /* x: set up for LEN */
4093 LEN, /* i: get length/literal/eob next */
4094 LENEXT, /* i: getting length extra (have base) */
4095 DIST, /* i: get distance next */
4096 DISTEXT, /* i: getting distance extra */
4097 COPY, /* o: copying bytes in window, waiting for space */
4098 LIT, /* o: got literal, waiting for output space */
4099 WASH, /* o: got eob, possibly still output waiting */
4100 END, /* x: got eob and all data flushed */
4101 BADCODE} /* x: got error */
4102 mode; /* current inflate_codes mode */
4104 /* mode dependent information */
4108 inflate_huft *tree; /* pointer into tree */
4109 uInt need; /* bits needed */
4110 } code; /* if LEN or DIST, where in tree */
4111 uInt lit; /* if LIT, literal */
4113 uInt get; /* bits to get for extra */
4114 uInt dist; /* distance back to copy from */
4115 } copy; /* if EXT or COPY, where and how much */
4116 } sub; /* submode */
4118 /* mode independent information */
4119 Byte lbits; /* ltree bits decoded per branch */
4120 Byte dbits; /* dtree bits decoder per branch */
4121 inflate_huft *ltree; /* literal/length/eob tree */
4122 inflate_huft *dtree; /* distance tree */
4127 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4129 inflate_huft *tl, *td;
4132 inflate_codes_statef *c;
4134 if ((c = (inflate_codes_statef *)
4135 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4138 c->lbits = (Byte)bl;
4139 c->dbits = (Byte)bd;
4142 Tracev((stderr, "inflate: codes new\n"));
4148 local int inflate_codes(s, z, r)
4149 inflate_blocks_statef *s;
4153 uInt j; /* temporary storage */
4154 inflate_huft *t; /* temporary pointer */
4155 uInt e; /* extra bits or operation */
4156 uLong b; /* bit buffer */
4157 uInt k; /* bits in bit buffer */
4158 Bytef *p; /* input data pointer */
4159 uInt n; /* bytes available there */
4160 Bytef *q; /* output window write pointer */
4161 uInt m; /* bytes to end of window or read pointer */
4162 Bytef *f; /* pointer to copy strings from */
4163 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4165 /* copy input/output information to locals (UPDATE macro restores) */
4168 /* process input and output based on current state */
4169 while (1) switch (c->mode)
4170 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4171 case START: /* x: set up for LEN */
4173 if (m >= 258 && n >= 10)
4176 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4180 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4185 c->sub.code.need = c->lbits;
4186 c->sub.code.tree = c->ltree;
4188 case LEN: /* i: get length/literal/eob next */
4189 j = c->sub.code.need;
4191 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4193 e = (uInt)(t->exop);
4194 if (e == 0) /* literal */
4196 c->sub.lit = t->base;
4197 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4198 "inflate: literal '%c'\n" :
4199 "inflate: literal 0x%02x\n", t->base));
4203 if (e & 16) /* length */
4205 c->sub.copy.get = e & 15;
4210 if ((e & 64) == 0) /* next table */
4212 c->sub.code.need = e;
4213 c->sub.code.tree = t->next;
4216 if (e & 32) /* end of block */
4218 Tracevv((stderr, "inflate: end of block\n"));
4222 c->mode = BADCODE; /* invalid code */
4223 z->msg = "invalid literal/length code";
4226 case LENEXT: /* i: getting length extra (have base) */
4227 j = c->sub.copy.get;
4229 c->len += (uInt)b & inflate_mask[j];
4231 c->sub.code.need = c->dbits;
4232 c->sub.code.tree = c->dtree;
4233 Tracevv((stderr, "inflate: length %u\n", c->len));
4235 case DIST: /* i: get distance next */
4236 j = c->sub.code.need;
4238 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4240 e = (uInt)(t->exop);
4241 if (e & 16) /* distance */
4243 c->sub.copy.get = e & 15;
4244 c->sub.copy.dist = t->base;
4248 if ((e & 64) == 0) /* next table */
4250 c->sub.code.need = e;
4251 c->sub.code.tree = t->next;
4254 c->mode = BADCODE; /* invalid code */
4255 z->msg = "invalid distance code";
4258 case DISTEXT: /* i: getting distance extra */
4259 j = c->sub.copy.get;
4261 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4263 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4265 case COPY: /* o: copying bytes in window, waiting for space */
4266 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4267 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4268 s->end - (c->sub.copy.dist - (q - s->window)) :
4269 q - c->sub.copy.dist;
4271 f = q - c->sub.copy.dist;
4272 if ((uInt)(q - s->window) < c->sub.copy.dist)
4273 f = s->end - (c->sub.copy.dist - (q - s->window));
4285 case LIT: /* o: got literal, waiting for output space */
4290 case WASH: /* o: got eob, possibly more output */
4292 if (s->read != s->write)
4298 case BADCODE: /* x: got error */
4308 local void inflate_codes_free(c, z)
4309 inflate_codes_statef *c;
4312 ZFREE(z, c, sizeof(struct inflate_codes_state));
4313 Tracev((stderr, "inflate: codes free\n"));
4317 /* inflate_util.c -- data and routines common to blocks and codes
4318 * Copyright (C) 1995 Mark Adler
4319 * For conditions of distribution and use, see copyright notice in zlib.h
4322 /* copy as much as possible from the sliding window to the output area */
4323 local int inflate_flush(s, z, r)
4324 inflate_blocks_statef *s;
4331 /* local copies of source and destination pointers */
4335 /* compute number of bytes to copy as far as end of window */
4336 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4337 if (n > z->avail_out) n = z->avail_out;
4338 if (n && r == Z_BUF_ERROR) r = Z_OK;
4340 /* update counters */
4344 /* update check information */
4345 if (s->checkfn != Z_NULL)
4346 s->check = (*s->checkfn)(s->check, q, n);
4348 /* copy as far as end of window */
4355 /* see if more to copy at beginning of window */
4360 if (s->write == s->end)
4361 s->write = s->window;
4363 /* compute bytes to copy */
4364 n = (uInt)(s->write - q);
4365 if (n > z->avail_out) n = z->avail_out;
4366 if (n && r == Z_BUF_ERROR) r = Z_OK;
4368 /* update counters */
4372 /* update check information */
4373 if (s->checkfn != Z_NULL)
4374 s->check = (*s->checkfn)(s->check, q, n);
4384 /* update pointers */
4394 /* inffast.c -- process literals and length/distance pairs fast
4395 * Copyright (C) 1995 Mark Adler
4396 * For conditions of distribution and use, see copyright notice in zlib.h
4399 /* simplify the use of the inflate_huft type with some defines */
4400 #define base more.Base
4401 #define next more.Next
4402 #define exop word.what.Exop
4403 #define bits word.what.Bits
4405 /* macros for bit input with no checking and for returning unused bytes */
4406 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4407 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4409 /* Called with number of bytes left to write in window at least 258
4410 (the maximum string length) and number of input bytes available
4411 at least ten. The ten bytes are six bytes for the longest length/
4412 distance pair plus four bytes for overloading the bit buffer. */
4414 local int inflate_fast(bl, bd, tl, td, s, z)
4416 inflate_huft *tl, *td;
4417 inflate_blocks_statef *s;
4420 inflate_huft *t; /* temporary pointer */
4421 uInt e; /* extra bits or operation */
4422 uLong b; /* bit buffer */
4423 uInt k; /* bits in bit buffer */
4424 Bytef *p; /* input data pointer */
4425 uInt n; /* bytes available there */
4426 Bytef *q; /* output window write pointer */
4427 uInt m; /* bytes to end of window or read pointer */
4428 uInt ml; /* mask for literal/length tree */
4429 uInt md; /* mask for distance tree */
4430 uInt c; /* bytes to copy */
4431 uInt d; /* distance back to copy from */
4432 Bytef *r; /* copy source pointer */
4434 /* load input, output, bit values */
4437 /* initialize masks */
4438 ml = inflate_mask[bl];
4439 md = inflate_mask[bd];
4441 /* do until not enough input or output space for fast loop */
4442 do { /* assume called with m >= 258 && n >= 10 */
4443 /* get literal/length code */
4444 GRABBITS(20) /* max bits for literal/length code */
4445 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4448 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4449 "inflate: * literal '%c'\n" :
4450 "inflate: * literal 0x%02x\n", t->base));
4451 *q++ = (Byte)t->base;
4459 /* get extra bits for length */
4461 c = t->base + ((uInt)b & inflate_mask[e]);
4463 Tracevv((stderr, "inflate: * length %u\n", c));
4465 /* decode distance base of block to copy */
4466 GRABBITS(15); /* max bits for distance code */
4467 e = (t = td + ((uInt)b & md))->exop;
4472 /* get extra bits to add to distance base */
4474 GRABBITS(e) /* get extra bits (up to 13) */
4475 d = t->base + ((uInt)b & inflate_mask[e]);
4477 Tracevv((stderr, "inflate: * distance %u\n", d));
4481 if ((uInt)(q - s->window) >= d) /* offset before dest */
4484 *q++ = *r++; c--; /* minimum count is three, */
4485 *q++ = *r++; c--; /* so unroll loop a little */
4487 else /* else offset after destination */
4489 e = d - (q - s->window); /* bytes from offset to end */
4490 r = s->end - e; /* pointer to offset */
4491 if (c > e) /* if source crosses, */
4493 c -= e; /* copy to end of window */
4497 r = s->window; /* copy rest from start of window */
4500 do { /* copy all or what's left */
4505 else if ((e & 64) == 0)
4506 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4509 z->msg = "invalid distance code";
4512 return Z_DATA_ERROR;
4519 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4522 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4523 "inflate: * literal '%c'\n" :
4524 "inflate: * literal 0x%02x\n", t->base));
4525 *q++ = (Byte)t->base;
4532 Tracevv((stderr, "inflate: * end of block\n"));
4535 return Z_STREAM_END;
4539 z->msg = "invalid literal/length code";
4542 return Z_DATA_ERROR;
4545 } while (m >= 258 && n >= 10);
4547 /* not enough input or output--restore pointers and return */
4555 /* zutil.c -- target dependent utility functions for the compression library
4556 * Copyright (C) 1995 Jean-loup Gailly.
4557 * For conditions of distribution and use, see copyright notice in zlib.h
4560 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
4562 char *zlib_version = ZLIB_VERSION;
4564 char *z_errmsg[] = {
4565 "stream end", /* Z_STREAM_END 1 */
4567 "file error", /* Z_ERRNO (-1) */
4568 "stream error", /* Z_STREAM_ERROR (-2) */
4569 "data error", /* Z_DATA_ERROR (-3) */
4570 "insufficient memory", /* Z_MEM_ERROR (-4) */
4571 "buffer error", /* Z_BUF_ERROR (-5) */
4576 /* adler32.c -- compute the Adler-32 checksum of a data stream
4577 * Copyright (C) 1995 Mark Adler
4578 * For conditions of distribution and use, see copyright notice in zlib.h
4581 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
4583 #define BASE 65521L /* largest prime smaller than 65536 */
4585 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4587 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4588 #define DO2(buf) DO1(buf); DO1(buf);
4589 #define DO4(buf) DO2(buf); DO2(buf);
4590 #define DO8(buf) DO4(buf); DO4(buf);
4591 #define DO16(buf) DO8(buf); DO8(buf);
4593 /* ========================================================================= */
4594 uLong adler32(adler, buf, len)
4599 unsigned long s1 = adler & 0xffff;
4600 unsigned long s2 = (adler >> 16) & 0xffff;
4603 if (buf == Z_NULL) return 1L;
4606 k = len < NMAX ? len : NMAX;
4618 return (s2 << 16) | s1;