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 Z_PACKET_FLUSH (see zlib.h for details)
11 * - added inflateIncomp
18 /* zutil.h -- internal interface and configuration of the compression library
19 * Copyright (C) 1995 Jean-loup Gailly.
20 * For conditions of distribution and use, see copyright notice in zlib.h
23 /* WARNING: this file should *not* be used by applications. It is
24 part of the implementation of the compression library and is
25 subject to change. Applications should only use zlib.h.
28 /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */
38 /* compile with -Dlocal if your debugger can't find static symbols */
42 typedef unsigned char uch;
44 typedef unsigned short ush;
46 typedef unsigned int ulg;
48 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
50 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
51 /* To be used only when the state is known to be valid */
54 #define NULL ((void *) 0)
57 /* common constants */
62 # define DEF_WBITS MAX_WBITS
64 /* default windowBits for decompression. MAX_WBITS is for compression only */
66 #if MAX_MEM_LEVEL >= 8
67 # define DEF_MEM_LEVEL 8
69 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
71 /* default memLevel */
73 #define STORED_BLOCK 0
74 #define STATIC_TREES 1
76 /* The three kinds of block type */
80 /* The minimum and maximum match lengths */
83 #define zmemcpy(d, s, n) bcopy((s), (d), (n))
84 #define zmemzero bzero
86 /* Diagnostic functions */
92 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
93 # define Trace(x) fprintf x
94 # define Tracev(x) {if (verbose) fprintf x ;}
95 # define Tracevv(x) {if (verbose>1) fprintf x ;}
96 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
97 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
99 # define Assert(cond,msg)
104 # define Tracecv(c,x)
108 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
110 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
111 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
113 #define ZALLOC(strm, items, size) \
114 (*((strm)->zalloc))((strm)->opaque, (items), (size))
115 #define ZFREE(strm, addr, size) \
116 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
117 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
119 /* deflate.h -- internal compression state
120 * Copyright (C) 1995 Jean-loup Gailly
121 * For conditions of distribution and use, see copyright notice in zlib.h
124 /* WARNING: this file should *not* be used by applications. It is
125 part of the implementation of the compression library and is
126 subject to change. Applications should only use zlib.h.
131 /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */
133 /* ===========================================================================
134 * Internal compression state.
142 #define LENGTH_CODES 29
143 /* number of length codes, not counting the special END_BLOCK code */
146 /* number of literal bytes 0..255 */
148 #define L_CODES (LITERALS+1+LENGTH_CODES)
149 /* number of Literal or Length codes, including the END_BLOCK code */
152 /* number of distance codes */
155 /* number of codes used to transfer the bit lengths */
157 #define HEAP_SIZE (2*L_CODES+1)
158 /* maximum heap size */
161 /* All codes must not exceed MAX_BITS bits */
163 #define INIT_STATE 42
164 #define BUSY_STATE 113
165 #define FLUSH_STATE 124
166 #define FINISH_STATE 666
170 /* Data structure describing a single value and its code string. */
171 typedef struct ct_data_s {
173 ush freq; /* frequency count */
174 ush code; /* bit string */
177 ush dad; /* father node in Huffman tree */
178 ush len; /* length of bit string */
187 typedef struct static_tree_desc_s static_tree_desc;
189 typedef struct tree_desc_s {
190 ct_data *dyn_tree; /* the dynamic tree */
191 int max_code; /* largest code with non zero frequency */
192 static_tree_desc *stat_desc; /* the corresponding static tree */
196 typedef Pos FAR Posf;
197 typedef unsigned IPos;
199 /* A Pos is an index in the character window. We use short instead of int to
200 * save space in the various tables. IPos is used only for parameter passing.
203 typedef struct deflate_state {
204 z_stream *strm; /* pointer back to this zlib stream */
205 int status; /* as the name implies */
206 Bytef *pending_buf; /* output still pending */
207 Bytef *pending_out; /* next pending byte to output to the stream */
208 int pending; /* nb of bytes in the pending buffer */
209 uLong adler; /* adler32 of uncompressed data */
210 int noheader; /* suppress zlib header and adler32 */
211 Byte data_type; /* UNKNOWN, BINARY or ASCII */
212 Byte method; /* STORED (for zip only) or DEFLATED */
214 /* used by deflate.c: */
216 uInt w_size; /* LZ77 window size (32K by default) */
217 uInt w_bits; /* log2(w_size) (8..16) */
218 uInt w_mask; /* w_size - 1 */
221 /* Sliding window. Input bytes are read into the second half of the window,
222 * and move to the first half later to keep a dictionary of at least wSize
223 * bytes. With this organization, matches are limited to a distance of
224 * wSize-MAX_MATCH bytes, but this ensures that IO is always
225 * performed with a length multiple of the block size. Also, it limits
226 * the window size to 64K, which is quite useful on MSDOS.
227 * To do: use the user input buffer as sliding window.
231 /* Actual size of window: 2*wSize, except when the user input buffer
232 * is directly used as sliding window.
236 /* Link to older string with same hash index. To limit the size of this
237 * array to 64K, this link is maintained only for the last 32K strings.
238 * An index in this array is thus a window index modulo 32K.
241 Posf *head; /* Heads of the hash chains or NIL. */
243 uInt ins_h; /* hash index of string to be inserted */
244 uInt hash_size; /* number of elements in hash table */
245 uInt hash_bits; /* log2(hash_size) */
246 uInt hash_mask; /* hash_size-1 */
249 /* Number of bits by which ins_h must be shifted at each input
250 * step. It must be such that after MIN_MATCH steps, the oldest
251 * byte no longer takes part in the hash key, that is:
252 * hash_shift * MIN_MATCH >= hash_bits
256 /* Window position at the beginning of the current output block. Gets
257 * negative when the window is moved backwards.
260 uInt match_length; /* length of best match */
261 IPos prev_match; /* previous match */
262 int match_available; /* set if previous match exists */
263 uInt strstart; /* start of string to insert */
264 uInt match_start; /* start of matching string */
265 uInt lookahead; /* number of valid bytes ahead in window */
268 /* Length of the best match at previous step. Matches not greater than this
269 * are discarded. This is used in the lazy match evaluation.
272 uInt max_chain_length;
273 /* To speed up deflation, hash chains are never searched beyond this
274 * length. A higher limit improves compression ratio but degrades the
279 /* Attempt to find a better match only when the current match is strictly
280 * smaller than this value. This mechanism is used only for compression
283 # define max_insert_length max_lazy_match
284 /* Insert new strings in the hash table only if the match length is not
285 * greater than this length. This saves time but degrades compression.
286 * max_insert_length is used only for compression levels <= 3.
289 int level; /* compression level (1..9) */
290 int strategy; /* favor or force Huffman coding*/
293 /* Use a faster search when the previous match is longer than this */
295 int nice_match; /* Stop searching when current match exceeds this */
297 /* used by trees.c: */
298 /* Didn't use ct_data typedef below to supress compiler warning */
299 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
300 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
301 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
303 struct tree_desc_s l_desc; /* desc. for literal tree */
304 struct tree_desc_s d_desc; /* desc. for distance tree */
305 struct tree_desc_s bl_desc; /* desc. for bit length tree */
307 ush bl_count[MAX_BITS+1];
308 /* number of codes at each bit length for an optimal tree */
310 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
311 int heap_len; /* number of elements in the heap */
312 int heap_max; /* element of largest frequency */
313 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
314 * The same heap array is used to build all trees.
317 uch depth[2*L_CODES+1];
318 /* Depth of each subtree used as tie breaker for trees of equal frequency
321 uchf *l_buf; /* buffer for literals or lengths */
324 /* Size of match buffer for literals/lengths. There are 4 reasons for
325 * limiting lit_bufsize to 64K:
326 * - frequencies can be kept in 16 bit counters
327 * - if compression is not successful for the first block, all input
328 * data is still in the window so we can still emit a stored block even
329 * when input comes from standard input. (This can also be done for
330 * all blocks if lit_bufsize is not greater than 32K.)
331 * - if compression is not successful for a file smaller than 64K, we can
332 * even emit a stored file instead of a stored block (saving 5 bytes).
333 * This is applicable only for zip (not gzip or zlib).
334 * - creating new Huffman trees less frequently may not provide fast
335 * adaptation to changes in the input data statistics. (Take for
336 * example a binary file with poorly compressible code followed by
337 * a highly compressible string table.) Smaller buffer sizes give
338 * fast adaptation but have of course the overhead of transmitting
339 * trees more frequently.
340 * - I can't count above 4
343 uInt last_lit; /* running index in l_buf */
346 /* Buffer for distances. To simplify the code, d_buf and l_buf have
347 * the same number of elements. To use different lengths, an extra flag
348 * array would be necessary.
351 ulg opt_len; /* bit length of current block with optimal trees */
352 ulg static_len; /* bit length of current block with static trees */
353 ulg compressed_len; /* total bit length of compressed file */
354 uInt matches; /* number of string matches in current block */
355 int last_eob_len; /* bit length of EOB code for last block */
358 ulg bits_sent; /* bit length of the compressed data */
362 /* Output buffer. bits are inserted starting at the bottom (least
366 /* Number of valid bits in bi_buf. All bits above the last valid bit
370 uInt blocks_in_packet;
371 /* Number of blocks produced since the last time Z_PACKET_FLUSH
377 /* Output a byte on the stream.
378 * IN assertion: there is enough room in pending_buf.
380 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
383 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
384 /* Minimum amount of lookahead, except at the end of the input file.
385 * See deflate.c for comments about the MIN_MATCH+1.
388 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
389 /* In order to simplify the code, particularly on 16 bit machines, match
390 * distances are limited to MAX_DIST instead of WSIZE.
394 local void ct_init OF((deflate_state *s));
395 local int ct_tally OF((deflate_state *s, int dist, int lc));
396 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
398 local void ct_align OF((deflate_state *s));
399 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
401 local void ct_stored_type_only OF((deflate_state *s));
405 /* deflate.c -- compress data using the deflation algorithm
406 * Copyright (C) 1995 Jean-loup Gailly.
407 * For conditions of distribution and use, see copyright notice in zlib.h
413 * The "deflation" process depends on being able to identify portions
414 * of the input text which are identical to earlier input (within a
415 * sliding window trailing behind the input currently being processed).
417 * The most straightforward technique turns out to be the fastest for
418 * most input files: try all possible matches and select the longest.
419 * The key feature of this algorithm is that insertions into the string
420 * dictionary are very simple and thus fast, and deletions are avoided
421 * completely. Insertions are performed at each input character, whereas
422 * string matches are performed only when the previous match ends. So it
423 * is preferable to spend more time in matches to allow very fast string
424 * insertions and avoid deletions. The matching algorithm for small
425 * strings is inspired from that of Rabin & Karp. A brute force approach
426 * is used to find longer strings when a small match has been found.
427 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
428 * (by Leonid Broukhis).
429 * A previous version of this file used a more sophisticated algorithm
430 * (by Fiala and Greene) which is guaranteed to run in linear amortized
431 * time, but has a larger average cost, uses more memory and is patented.
432 * However the F&G algorithm may be faster for some highly redundant
433 * files if the parameter max_chain_length (described below) is too large.
437 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
438 * I found it in 'freeze' written by Leonid Broukhis.
439 * Thanks to many people for bug reports and testing.
443 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
444 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
446 * A description of the Rabin and Karp algorithm is given in the book
447 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
449 * Fiala,E.R., and Greene,D.H.
450 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
454 /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */
456 char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
458 If you use the zlib library in a product, an acknowledgment is welcome
459 in the documentation of your product. If for some reason you cannot
460 include such an acknowledgment, I would appreciate that you keep this
461 copyright string in the executable of your product.
465 /* Tail of hash chains */
468 # define TOO_FAR 4096
470 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
472 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
473 /* Minimum amount of lookahead, except at the end of the input file.
474 * See deflate.c for comments about the MIN_MATCH+1.
477 /* Values for max_lazy_match, good_match and max_chain_length, depending on
478 * the desired pack level (0..9). The values given below have been tuned to
479 * exclude worst case performance for pathological files. Better values may be
480 * found for specific files.
483 typedef struct config_s {
484 ush good_length; /* reduce lazy search above this match length */
485 ush max_lazy; /* do not perform lazy search above this match length */
486 ush nice_length; /* quit search above this match length */
490 local config configuration_table[10] = {
491 /* good lazy nice chain */
492 /* 0 */ {0, 0, 0, 0}, /* store only */
493 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
494 /* 2 */ {4, 5, 16, 8},
495 /* 3 */ {4, 6, 32, 32},
497 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
498 /* 5 */ {8, 16, 32, 32},
499 /* 6 */ {8, 16, 128, 128},
500 /* 7 */ {8, 32, 128, 256},
501 /* 8 */ {32, 128, 258, 1024},
502 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
504 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
505 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
510 /* result of memcmp for equal strings */
512 /* ===========================================================================
513 * Prototypes for local functions.
516 local void fill_window OF((deflate_state *s));
517 local int deflate_fast OF((deflate_state *s, int flush));
518 local int deflate_slow OF((deflate_state *s, int flush));
519 local void lm_init OF((deflate_state *s));
520 local int longest_match OF((deflate_state *s, IPos cur_match));
521 local void putShortMSB OF((deflate_state *s, uInt b));
522 local void flush_pending OF((z_stream *strm));
523 local int zread_buf OF((z_stream *strm, charf *buf, unsigned size));
525 void match_init OF((void)); /* asm code initialization */
529 local void check_match OF((deflate_state *s, IPos start, IPos match,
534 /* ===========================================================================
535 * Update a hash value with the given input byte
536 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
537 * input characters, so that a running hash key can be computed from the
538 * previous key instead of complete recalculation each time.
540 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
543 /* ===========================================================================
544 * Insert string str in the dictionary and set match_head to the previous head
545 * of the hash chain (the most recent string with same hash key). Return
546 * the previous length of the hash chain.
547 * IN assertion: all calls to to INSERT_STRING are made with consecutive
548 * input characters and the first MIN_MATCH bytes of str are valid
549 * (except for the last MIN_MATCH-1 bytes of the input file).
551 #define INSERT_STRING(s, str, match_head) \
552 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
553 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
554 s->head[s->ins_h] = (str))
556 /* ===========================================================================
557 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
558 * prev[] will be initialized on the fly.
560 #define CLEAR_HASH(s) \
561 s->head[s->hash_size-1] = NIL; \
562 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
564 /* ========================================================================= */
565 int deflateInit (strm, level)
569 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 0);
570 /* To do: ignore strm->next_in if we use it as window */
573 /* ========================================================================= */
574 int deflateInit2 (strm, level, method, windowBits, memLevel, strategy)
585 if (strm == Z_NULL) return Z_STREAM_ERROR;
588 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
589 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
591 if (level == Z_DEFAULT_COMPRESSION) level = 6;
593 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
595 windowBits = -windowBits;
597 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
598 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
599 return Z_STREAM_ERROR;
601 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
602 if (s == Z_NULL) return Z_MEM_ERROR;
603 bzero(s, sizeof(*s));
604 strm->state = (struct internal_state FAR *)s;
607 s->noheader = noheader;
608 s->w_bits = windowBits;
609 s->w_size = 1 << s->w_bits;
610 s->w_mask = s->w_size - 1;
612 s->hash_bits = memLevel + 7;
613 s->hash_size = 1 << s->hash_bits;
614 s->hash_mask = s->hash_size - 1;
615 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
617 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
618 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
619 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
621 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
623 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
625 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
626 s->pending_buf == Z_NULL) {
627 strm->msg = z_errmsg[1-Z_MEM_ERROR];
631 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
632 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
633 /* We overlay pending_buf and d_buf+l_buf. This works since the average
634 * output size for (length,distance) codes is <= 32 bits (worst case
639 s->strategy = strategy;
640 s->method = (Byte)method;
641 s->blocks_in_packet = 0;
643 return deflateReset(strm);
646 /* ========================================================================= */
647 int deflateReset (strm)
652 if (strm == Z_NULL || strm->state == Z_NULL ||
653 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
655 strm->total_in = strm->total_out = 0;
656 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
657 strm->data_type = Z_UNKNOWN;
659 s = (deflate_state *)strm->state;
661 s->pending_out = s->pending_buf;
663 if (s->noheader < 0) {
664 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
666 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
675 /* =========================================================================
676 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
677 * IN assertion: the stream state is correct and there is enough room in
680 local void putShortMSB (s, b)
684 put_byte(s, (Byte)(b >> 8));
685 put_byte(s, (Byte)(b & 0xff));
688 /* =========================================================================
689 * Flush as much pending output as possible.
691 local void flush_pending(strm)
694 deflate_state *state = (deflate_state *) strm->state;
695 unsigned len = state->pending;
697 if (len > strm->avail_out) len = strm->avail_out;
698 if (len == 0) return;
700 if (strm->next_out != NULL) {
701 zmemcpy(strm->next_out, state->pending_out, len);
702 strm->next_out += len;
704 state->pending_out += len;
705 strm->total_out += len;
706 strm->avail_out -= len;
707 state->pending -= len;
708 if (state->pending == 0) {
709 state->pending_out = state->pending_buf;
713 /* ========================================================================= */
714 int deflate (strm, flush)
718 deflate_state *state = (deflate_state *) strm->state;
720 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
722 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
723 ERR_RETURN(strm, Z_STREAM_ERROR);
725 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
727 state->strm = strm; /* just in case */
729 /* Write the zlib header */
730 if (state->status == INIT_STATE) {
732 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
733 uInt level_flags = (state->level-1) >> 1;
735 if (level_flags > 3) level_flags = 3;
736 header |= (level_flags << 6);
737 header += 31 - (header % 31);
739 state->status = BUSY_STATE;
740 putShortMSB(state, header);
743 /* Flush as much pending output as possible */
744 if (state->pending != 0) {
746 if (strm->avail_out == 0) return Z_OK;
749 /* If we came back in here to get the last output from
750 * a previous flush, we're done for now.
752 if (state->status == FLUSH_STATE) {
753 state->status = BUSY_STATE;
754 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
758 /* User must not provide more input after the first FINISH: */
759 if (state->status == FINISH_STATE && strm->avail_in != 0) {
760 ERR_RETURN(strm, Z_BUF_ERROR);
763 /* Start a new block or continue the current one.
765 if (strm->avail_in != 0 || state->lookahead != 0 ||
766 (flush == Z_FINISH && state->status != FINISH_STATE)) {
769 if (flush == Z_FINISH) {
770 state->status = FINISH_STATE;
772 if (state->level <= 3) {
773 quit = deflate_fast(state, flush);
775 quit = deflate_slow(state, flush);
777 if (quit || strm->avail_out == 0)
779 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
780 * of deflate should use the same flush parameter to make sure
781 * that the flush is complete. So we don't have to output an
782 * empty block here, this will be done at next call. This also
783 * ensures that for a very small output buffer, we emit at most
788 /* If a flush was requested, we have a little more to output now. */
789 if (flush != Z_NO_FLUSH && flush != Z_FINISH
790 && state->status != FINISH_STATE) {
792 case Z_PARTIAL_FLUSH:
796 /* Output just the 3-bit `stored' block type value,
797 but not a zero length. */
798 ct_stored_type_only(state);
801 ct_stored_block(state, (char*)0, 0L, 0);
802 /* For a full flush, this empty block will be recognized
803 * as a special marker by inflate_sync().
805 if (flush == Z_FULL_FLUSH) {
806 CLEAR_HASH(state); /* forget history */
810 if (strm->avail_out == 0) {
811 /* We'll have to come back to get the rest of the output;
812 * this ensures we don't output a second zero-length stored
813 * block (or whatever).
815 state->status = FLUSH_STATE;
820 Assert(strm->avail_out > 0, "bug2");
822 if (flush != Z_FINISH) return Z_OK;
823 if (state->noheader) return Z_STREAM_END;
825 /* Write the zlib trailer (adler32) */
826 putShortMSB(state, (uInt)(state->adler >> 16));
827 putShortMSB(state, (uInt)(state->adler & 0xffff));
829 /* If avail_out is zero, the application will call deflate again
832 state->noheader = -1; /* write the trailer only once! */
833 return state->pending != 0 ? Z_OK : Z_STREAM_END;
836 /* ========================================================================= */
837 int deflateEnd (strm)
840 deflate_state *state = (deflate_state *) strm->state;
842 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
844 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
845 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
846 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
847 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
849 ZFREE(strm, state, sizeof(deflate_state));
850 strm->state = Z_NULL;
855 /* ===========================================================================
856 * Read a new buffer from the current input stream, update the adler32
857 * and total number of bytes read.
859 local int zread_buf(strm, buf, size)
864 unsigned len = strm->avail_in;
865 deflate_state *state = (deflate_state *) strm->state;
867 if (len > size) len = size;
868 if (len == 0) return 0;
870 strm->avail_in -= len;
872 if (!state->noheader) {
873 state->adler = adler32(state->adler, strm->next_in, len);
875 zmemcpy(buf, strm->next_in, len);
876 strm->next_in += len;
877 strm->total_in += len;
882 /* ===========================================================================
883 * Initialize the "longest match" routines for a new zlib stream
885 local void lm_init (s)
888 s->window_size = (ulg)2L*s->w_size;
892 /* Set the default configuration parameters:
894 s->max_lazy_match = configuration_table[s->level].max_lazy;
895 s->good_match = configuration_table[s->level].good_length;
896 s->nice_match = configuration_table[s->level].nice_length;
897 s->max_chain_length = configuration_table[s->level].max_chain;
902 s->match_length = MIN_MATCH-1;
903 s->match_available = 0;
906 match_init(); /* initialize the asm code */
910 /* ===========================================================================
911 * Set match_start to the longest match starting at the given string and
912 * return its length. Matches shorter or equal to prev_length are discarded,
913 * in which case the result is equal to prev_length and match_start is
915 * IN assertions: cur_match is the head of the hash chain for the current
916 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
919 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
920 * match.S. The code will be functionally equivalent.
922 local int longest_match(s, cur_match)
924 IPos cur_match; /* current match */
926 unsigned chain_length = s->max_chain_length;/* max hash chain length */
927 register Bytef *scan = s->window + s->strstart; /* current string */
928 register Bytef *match; /* matched string */
929 register int len; /* length of current match */
930 int best_len = s->prev_length; /* best match length so far */
931 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
932 s->strstart - (IPos)MAX_DIST(s) : NIL;
933 /* Stop when cur_match becomes <= limit. To simplify the code,
934 * we prevent matches with the string of window index 0.
936 Posf *prev = s->prev;
937 uInt wmask = s->w_mask;
940 /* Compare two bytes at a time. Note: this is not always beneficial.
941 * Try with and without -DUNALIGNED_OK to check.
943 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
944 register ush scan_start = *(ushf*)scan;
945 register ush scan_end = *(ushf*)(scan+best_len-1);
947 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
948 register Byte scan_end1 = scan[best_len-1];
949 register Byte scan_end = scan[best_len];
952 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
953 * It is easy to get rid of this optimization if necessary.
955 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
957 /* Do not waste too much time if we already have a good match: */
958 if (s->prev_length >= s->good_match) {
961 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
964 Assert(cur_match < s->strstart, "no future");
965 match = s->window + cur_match;
967 /* Skip to next match if the match length cannot increase
968 * or if the match length is less than 2:
970 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
971 /* This code assumes sizeof(unsigned short) == 2. Do not use
972 * UNALIGNED_OK if your compiler uses a different size.
974 if (*(ushf*)(match+best_len-1) != scan_end ||
975 *(ushf*)match != scan_start) continue;
977 /* It is not necessary to compare scan[2] and match[2] since they are
978 * always equal when the other bytes match, given that the hash keys
979 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
980 * strstart+3, +5, ... up to strstart+257. We check for insufficient
981 * lookahead only every 4th comparison; the 128th check will be made
982 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
983 * necessary to put more guard bytes at the end of the window, or
984 * to check more often for insufficient lookahead.
986 Assert(scan[2] == match[2], "scan[2]?");
989 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
990 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
991 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
992 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
994 /* The funny "do {}" generates better code on most compilers */
996 /* Here, scan <= window+strstart+257 */
997 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
998 if (*scan == *match) scan++;
1000 len = (MAX_MATCH - 1) - (int)(strend-scan);
1001 scan = strend - (MAX_MATCH-1);
1003 #else /* UNALIGNED_OK */
1005 if (match[best_len] != scan_end ||
1006 match[best_len-1] != scan_end1 ||
1008 *++match != scan[1]) continue;
1010 /* The check at best_len-1 can be removed because it will be made
1011 * again later. (This heuristic is not always a win.)
1012 * It is not necessary to compare scan[2] and match[2] since they
1013 * are always equal when the other bytes match, given that
1014 * the hash keys are equal and that HASH_BITS >= 8.
1017 Assert(*scan == *match, "match[2]?");
1019 /* We check for insufficient lookahead only every 8th comparison;
1020 * the 256th check will be made at strstart+258.
1023 } while (*++scan == *++match && *++scan == *++match &&
1024 *++scan == *++match && *++scan == *++match &&
1025 *++scan == *++match && *++scan == *++match &&
1026 *++scan == *++match && *++scan == *++match &&
1029 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1031 len = MAX_MATCH - (int)(strend - scan);
1032 scan = strend - MAX_MATCH;
1034 #endif /* UNALIGNED_OK */
1036 if (len > best_len) {
1037 s->match_start = cur_match;
1039 if (len >= s->nice_match) break;
1041 scan_end = *(ushf*)(scan+best_len-1);
1043 scan_end1 = scan[best_len-1];
1044 scan_end = scan[best_len];
1047 } while ((cur_match = prev[cur_match & wmask]) > limit
1048 && --chain_length != 0);
1055 /* ===========================================================================
1056 * Check that the match at match_start is indeed a match.
1058 local void check_match(s, start, match, length)
1063 /* check that the match is indeed a match */
1064 if (memcmp((charf *)s->window + match,
1065 (charf *)s->window + start, length) != EQUAL) {
1067 " start %u, match %u, length %d\n",
1068 start, match, length);
1069 do { fprintf(stderr, "%c%c", s->window[match++],
1070 s->window[start++]); } while (--length != 0);
1071 z_error("invalid match");
1074 fprintf(stderr,"\\[%d,%d]", start-match, length);
1075 do { putc(s->window[start++], stderr); } while (--length != 0);
1079 # define check_match(s, start, match, length)
1082 /* ===========================================================================
1083 * Fill the window when the lookahead becomes insufficient.
1084 * Updates strstart and lookahead.
1086 * IN assertion: lookahead < MIN_LOOKAHEAD
1087 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1088 * At least one byte has been read, or avail_in == 0; reads are
1089 * performed for at least two bytes (required for the zip translate_eol
1090 * option -- not supported here).
1092 local void fill_window(s)
1095 register unsigned n, m;
1097 unsigned more; /* Amount of free space at the end of the window. */
1098 uInt wsize = s->w_size;
1101 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1103 /* Deal with !@#$% 64K limit: */
1104 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1106 } else if (more == (unsigned)(-1)) {
1107 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1108 * and lookahead == 1 (input done one byte at time)
1112 /* If the window is almost full and there is insufficient lookahead,
1113 * move the upper half to the lower one to make room in the upper half.
1115 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1117 /* By the IN assertion, the window is not empty so we can't confuse
1118 * more == 0 with more == 64K on a 16 bit machine.
1120 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1122 s->match_start -= wsize;
1123 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1125 s->block_start -= (Long) wsize;
1127 /* Slide the hash table (could be avoided with 32 bit values
1128 at the expense of memory usage):
1134 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1141 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1142 /* If n is not on any hash chain, prev[n] is garbage but
1143 * its value will never be used.
1149 if (s->strm->avail_in == 0) return;
1151 /* If there was no sliding:
1152 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1153 * more == window_size - lookahead - strstart
1154 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1155 * => more >= window_size - 2*WSIZE + 2
1156 * In the BIG_MEM or MMAP case (not yet supported),
1157 * window_size == input_size + MIN_LOOKAHEAD &&
1158 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1159 * Otherwise, window_size == 2*WSIZE so more >= 2.
1160 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1162 Assert(more >= 2, "more < 2");
1164 n = zread_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1168 /* Initialize the hash value now that we have some input: */
1169 if (s->lookahead >= MIN_MATCH) {
1170 s->ins_h = s->window[s->strstart];
1171 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1173 Call UPDATE_HASH() MIN_MATCH-3 more times
1176 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1177 * but this is not important since only literal bytes will be emitted.
1180 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1183 /* ===========================================================================
1184 * Flush the current block, with given end-of-file flag.
1185 * IN assertion: strstart is set to the end of the current match.
1187 #define FLUSH_BLOCK_ONLY(s, flush) { \
1188 ct_flush_block(s, (s->block_start >= 0L ? \
1189 (charf *)&s->window[(unsigned)s->block_start] : \
1190 (charf *)Z_NULL), (Long)s->strstart - s->block_start, (flush)); \
1191 s->block_start = s->strstart; \
1192 flush_pending(s->strm); \
1193 Tracev((stderr,"[FLUSH]")); \
1196 /* Same but force premature exit if necessary. */
1197 #define FLUSH_BLOCK(s, flush) { \
1198 FLUSH_BLOCK_ONLY(s, flush); \
1199 if (s->strm->avail_out == 0) return 1; \
1202 /* ===========================================================================
1203 * Compress as much as possible from the input stream, return true if
1204 * processing was terminated prematurely (no more input or output space).
1205 * This function does not perform lazy evaluationof matches and inserts
1206 * new strings in the dictionary only for unmatched strings or for short
1207 * matches. It is used only for the fast compression options.
1209 local int deflate_fast(s, flush)
1213 IPos hash_head = NIL; /* head of the hash chain */
1214 int bflush; /* set if current block must be flushed */
1216 s->prev_length = MIN_MATCH-1;
1219 /* Make sure that we always have enough lookahead, except
1220 * at the end of the input file. We need MAX_MATCH bytes
1221 * for the next match, plus MIN_MATCH bytes to insert the
1222 * string following the next match.
1224 if (s->lookahead < MIN_LOOKAHEAD) {
1226 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1228 if (s->lookahead == 0) break; /* flush the current block */
1231 /* Insert the string window[strstart .. strstart+2] in the
1232 * dictionary, and set hash_head to the head of the hash chain:
1234 if (s->lookahead >= MIN_MATCH) {
1235 INSERT_STRING(s, s->strstart, hash_head);
1238 /* Find the longest match, discarding those <= prev_length.
1239 * At this point we have always match_length < MIN_MATCH
1241 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1242 /* To simplify the code, we prevent matches with the string
1243 * of window index 0 (in particular we have to avoid a match
1244 * of the string with itself at the start of the input file).
1246 if (s->strategy != Z_HUFFMAN_ONLY) {
1247 s->match_length = longest_match (s, hash_head);
1249 /* longest_match() sets match_start */
1251 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1253 if (s->match_length >= MIN_MATCH) {
1254 check_match(s, s->strstart, s->match_start, s->match_length);
1256 bflush = ct_tally(s, s->strstart - s->match_start,
1257 s->match_length - MIN_MATCH);
1259 s->lookahead -= s->match_length;
1261 /* Insert new strings in the hash table only if the match length
1262 * is not too large. This saves time but degrades compression.
1264 if (s->match_length <= s->max_insert_length &&
1265 s->lookahead >= MIN_MATCH) {
1266 s->match_length--; /* string at strstart already in hash table */
1269 INSERT_STRING(s, s->strstart, hash_head);
1270 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1271 * always MIN_MATCH bytes ahead.
1273 } while (--s->match_length != 0);
1276 s->strstart += s->match_length;
1277 s->match_length = 0;
1278 s->ins_h = s->window[s->strstart];
1279 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1281 Call UPDATE_HASH() MIN_MATCH-3 more times
1283 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1284 * matter since it will be recomputed at next deflate call.
1288 /* No match, output a literal byte */
1289 Tracevv((stderr,"%c", s->window[s->strstart]));
1290 bflush = ct_tally (s, 0, s->window[s->strstart]);
1294 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1296 FLUSH_BLOCK(s, flush);
1297 return 0; /* normal exit */
1300 /* ===========================================================================
1301 * Same as above, but achieves better compression. We use a lazy
1302 * evaluation for matches: a match is finally adopted only if there is
1303 * no better match at the next window position.
1305 local int deflate_slow(s, flush)
1309 IPos hash_head = NIL; /* head of hash chain */
1310 int bflush; /* set if current block must be flushed */
1312 /* Process the input block. */
1314 /* Make sure that we always have enough lookahead, except
1315 * at the end of the input file. We need MAX_MATCH bytes
1316 * for the next match, plus MIN_MATCH bytes to insert the
1317 * string following the next match.
1319 if (s->lookahead < MIN_LOOKAHEAD) {
1321 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1323 if (s->lookahead == 0) break; /* flush the current block */
1326 /* Insert the string window[strstart .. strstart+2] in the
1327 * dictionary, and set hash_head to the head of the hash chain:
1329 if (s->lookahead >= MIN_MATCH) {
1330 INSERT_STRING(s, s->strstart, hash_head);
1333 if (flush == Z_INSERT_ONLY) {
1339 /* Find the longest match, discarding those <= prev_length.
1341 s->prev_length = s->match_length, s->prev_match = s->match_start;
1342 s->match_length = MIN_MATCH-1;
1344 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1345 s->strstart - hash_head <= MAX_DIST(s)) {
1346 /* To simplify the code, we prevent matches with the string
1347 * of window index 0 (in particular we have to avoid a match
1348 * of the string with itself at the start of the input file).
1350 if (s->strategy != Z_HUFFMAN_ONLY) {
1351 s->match_length = longest_match (s, hash_head);
1353 /* longest_match() sets match_start */
1354 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1356 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1357 (s->match_length == MIN_MATCH &&
1358 s->strstart - s->match_start > TOO_FAR))) {
1360 /* If prev_match is also MIN_MATCH, match_start is garbage
1361 * but we will ignore the current match anyway.
1363 s->match_length = MIN_MATCH-1;
1366 /* If there was a match at the previous step and the current
1367 * match is not better, output the previous match:
1369 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1370 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1371 /* Do not insert strings in hash table beyond this. */
1373 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1375 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1376 s->prev_length - MIN_MATCH);
1378 /* Insert in hash table all strings up to the end of the match.
1379 * strstart-1 and strstart are already inserted. If there is not
1380 * enough lookahead, the last two strings are not inserted in
1383 s->lookahead -= s->prev_length-1;
1384 s->prev_length -= 2;
1386 if (++s->strstart <= max_insert) {
1387 INSERT_STRING(s, s->strstart, hash_head);
1389 } while (--s->prev_length != 0);
1390 s->match_available = 0;
1391 s->match_length = MIN_MATCH-1;
1394 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1396 } else if (s->match_available) {
1397 /* If there was no match at the previous position, output a
1398 * single literal. If there was a match but the current match
1399 * is longer, truncate the previous match to a single literal.
1401 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1402 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1403 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1407 if (s->strm->avail_out == 0) return 1;
1409 /* There is no previous match to compare with, wait for
1410 * the next step to decide.
1412 s->match_available = 1;
1417 if (flush == Z_INSERT_ONLY) {
1418 s->block_start = s->strstart;
1421 Assert (flush != Z_NO_FLUSH, "no flush?");
1422 if (s->match_available) {
1423 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1424 ct_tally (s, 0, s->window[s->strstart-1]);
1425 s->match_available = 0;
1427 FLUSH_BLOCK(s, flush);
1433 /* trees.c -- output deflated data using Huffman coding
1434 * Copyright (C) 1995 Jean-loup Gailly
1435 * For conditions of distribution and use, see copyright notice in zlib.h
1441 * The "deflation" process uses several Huffman trees. The more
1442 * common source values are represented by shorter bit sequences.
1444 * Each code tree is stored in a compressed form which is itself
1445 * a Huffman encoding of the lengths of all the code strings (in
1446 * ascending order by source values). The actual code strings are
1447 * reconstructed from the lengths in the inflate process, as described
1448 * in the deflate specification.
1452 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1453 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1456 * Data Compression: Methods and Theory, pp. 49-50.
1457 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1461 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1464 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
1470 /* ===========================================================================
1474 #define MAX_BL_BITS 7
1475 /* Bit length codes must not exceed MAX_BL_BITS bits */
1477 #define END_BLOCK 256
1478 /* end of block literal code */
1481 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1483 #define REPZ_3_10 17
1484 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1486 #define REPZ_11_138 18
1487 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1489 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1490 = {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};
1492 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1493 = {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};
1495 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1496 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1498 local uch bl_order[BL_CODES]
1499 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1500 /* The lengths of the bit length codes are sent in order of decreasing
1501 * probability, to avoid transmitting the lengths for unused bit length codes.
1504 #define Buf_size (8 * 2*sizeof(char))
1505 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1506 * more than 16 bits on some systems.)
1509 /* ===========================================================================
1510 * Local data. These are initialized only once.
1511 * To do: initialize at compile time to be completely reentrant. ???
1514 local ct_data static_ltree[L_CODES+2];
1515 /* The static literal tree. Since the bit lengths are imposed, there is no
1516 * need for the L_CODES extra codes used during heap construction. However
1517 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1521 local ct_data static_dtree[D_CODES];
1522 /* The static distance tree. (Actually a trivial tree since all codes use
1526 local uch dist_code[512];
1527 /* distance codes. The first 256 values correspond to the distances
1528 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1529 * the 15 bit distances.
1532 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1533 /* length code for each normalized match length (0 == MIN_MATCH) */
1535 local int base_length[LENGTH_CODES];
1536 /* First normalized length for each code (0 = MIN_MATCH) */
1538 local int base_dist[D_CODES];
1539 /* First normalized distance for each code (0 = distance of 1) */
1541 struct static_tree_desc_s {
1542 ct_data *static_tree; /* static tree or NULL */
1543 intf *extra_bits; /* extra bits for each code or NULL */
1544 int extra_base; /* base index for extra_bits */
1545 int elems; /* max number of elements in the tree */
1546 int max_length; /* max bit length for the codes */
1549 local static_tree_desc static_l_desc =
1550 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1552 local static_tree_desc static_d_desc =
1553 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1555 local static_tree_desc static_bl_desc =
1556 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1558 /* ===========================================================================
1559 * Local (static) routines in this file.
1562 local void ct_static_init OF((void));
1563 local void init_block OF((deflate_state *s));
1564 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1565 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1566 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1567 local void build_tree OF((deflate_state *s, tree_desc *desc));
1568 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1569 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1570 local int build_bl_tree OF((deflate_state *s));
1571 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1573 local void compress_block OF((deflate_state *s, ct_data *ltree,
1575 local void set_data_type OF((deflate_state *s));
1576 local unsigned bi_reverse OF((unsigned value, int length));
1577 local void bi_windup OF((deflate_state *s));
1578 local void bi_flush OF((deflate_state *s));
1579 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1583 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1584 /* Send a code of the given tree. c and tree must not have side effects */
1586 #else /* DEBUG_ZLIB */
1587 # define send_code(s, c, tree) \
1588 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1589 send_bits(s, tree[c].Code, tree[c].Len); }
1592 #define d_code(dist) \
1593 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1594 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1595 * must not have side effects. dist_code[256] and dist_code[257] are never
1599 /* ===========================================================================
1600 * Output a short LSB first on the stream.
1601 * IN assertion: there is enough room in pendingBuf.
1603 #define put_short(s, w) { \
1604 put_byte(s, (uch)((w) & 0xff)); \
1605 put_byte(s, (uch)((ush)(w) >> 8)); \
1608 /* ===========================================================================
1609 * Send a value on a given number of bits.
1610 * IN assertion: length <= 16 and value fits in length bits.
1613 local void send_bits OF((deflate_state *s, int value, int length));
1615 local void send_bits(s, value, length)
1617 int value; /* value to send */
1618 int length; /* number of bits */
1620 Tracev((stderr," l %2d v %4x ", length, value));
1621 Assert(length > 0 && length <= 15, "invalid length");
1622 s->bits_sent += (ulg)length;
1624 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1625 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1626 * unused bits in value.
1628 if (s->bi_valid > (int)Buf_size - length) {
1629 s->bi_buf |= (value << s->bi_valid);
1630 put_short(s, s->bi_buf);
1631 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1632 s->bi_valid += length - Buf_size;
1634 s->bi_buf |= value << s->bi_valid;
1635 s->bi_valid += length;
1638 #else /* !DEBUG_ZLIB */
1640 #define send_bits(s, value, length) \
1641 { int len = length;\
1642 if (s->bi_valid > (int)Buf_size - len) {\
1644 s->bi_buf |= (val << s->bi_valid);\
1645 put_short(s, s->bi_buf);\
1646 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1647 s->bi_valid += len - Buf_size;\
1649 s->bi_buf |= (value) << s->bi_valid;\
1650 s->bi_valid += len;\
1653 #endif /* DEBUG_ZLIB */
1656 /* the arguments must not have side effects */
1658 /* ===========================================================================
1659 * Initialize the various 'constant' tables.
1660 * To do: do this at compile time.
1662 local void ct_static_init()
1664 int n; /* iterates over tree elements */
1665 int bits; /* bit counter */
1666 int length; /* length value */
1667 int code; /* code value */
1668 int dist; /* distance index */
1669 ush bl_count[MAX_BITS+1];
1670 /* number of codes at each bit length for an optimal tree */
1672 /* Initialize the mapping length (0..255) -> length code (0..28) */
1674 for (code = 0; code < LENGTH_CODES-1; code++) {
1675 base_length[code] = length;
1676 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1677 length_code[length++] = (uch)code;
1680 Assert (length == 256, "ct_static_init: length != 256");
1681 /* Note that the length 255 (match length 258) can be represented
1682 * in two different ways: code 284 + 5 bits or code 285, so we
1683 * overwrite length_code[255] to use the best encoding:
1685 length_code[length-1] = (uch)code;
1687 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1689 for (code = 0 ; code < 16; code++) {
1690 base_dist[code] = dist;
1691 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1692 dist_code[dist++] = (uch)code;
1695 Assert (dist == 256, "ct_static_init: dist != 256");
1696 dist >>= 7; /* from now on, all distances are divided by 128 */
1697 for ( ; code < D_CODES; code++) {
1698 base_dist[code] = dist << 7;
1699 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1700 dist_code[256 + dist++] = (uch)code;
1703 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1705 /* Construct the codes of the static literal tree */
1706 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1708 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1709 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1710 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1711 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1712 /* Codes 286 and 287 do not exist, but we must include them in the
1713 * tree construction to get a canonical Huffman tree (longest code
1716 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1718 /* The static distance tree is trivial: */
1719 for (n = 0; n < D_CODES; n++) {
1720 static_dtree[n].Len = 5;
1721 static_dtree[n].Code = bi_reverse(n, 5);
1725 /* ===========================================================================
1726 * Initialize the tree data structures for a new zlib stream.
1728 local void ct_init(s)
1731 if (static_dtree[0].Len == 0) {
1732 ct_static_init(); /* To do: at compile time */
1735 s->compressed_len = 0L;
1737 s->l_desc.dyn_tree = s->dyn_ltree;
1738 s->l_desc.stat_desc = &static_l_desc;
1740 s->d_desc.dyn_tree = s->dyn_dtree;
1741 s->d_desc.stat_desc = &static_d_desc;
1743 s->bl_desc.dyn_tree = s->bl_tree;
1744 s->bl_desc.stat_desc = &static_bl_desc;
1748 s->last_eob_len = 8; /* enough lookahead for inflate */
1752 s->blocks_in_packet = 0;
1754 /* Initialize the first block of the first file: */
1758 /* ===========================================================================
1759 * Initialize a new block.
1761 local void init_block(s)
1764 int n; /* iterates over tree elements */
1766 /* Initialize the trees. */
1767 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1768 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1769 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1771 s->dyn_ltree[END_BLOCK].Freq = 1;
1772 s->opt_len = s->static_len = 0L;
1773 s->last_lit = s->matches = 0;
1777 /* Index within the heap array of least frequent node in the Huffman tree */
1780 /* ===========================================================================
1781 * Remove the smallest element from the heap and recreate the heap with
1782 * one less element. Updates heap and heap_len.
1784 #define pqremove(s, tree, top) \
1786 top = s->heap[SMALLEST]; \
1787 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1788 pqdownheap(s, tree, SMALLEST); \
1791 /* ===========================================================================
1792 * Compares to subtrees, using the tree depth as tie breaker when
1793 * the subtrees have equal frequency. This minimizes the worst case length.
1795 #define smaller(tree, n, m, depth) \
1796 (tree[n].Freq < tree[m].Freq || \
1797 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1799 /* ===========================================================================
1800 * Restore the heap property by moving down the tree starting at node k,
1801 * exchanging a node with the smallest of its two sons if necessary, stopping
1802 * when the heap property is re-established (each father smaller than its
1805 local void pqdownheap(s, tree, k)
1807 ct_data *tree; /* the tree to restore */
1808 int k; /* node to move down */
1811 int j = k << 1; /* left son of k */
1812 while (j <= s->heap_len) {
1813 /* Set j to the smallest of the two sons: */
1814 if (j < s->heap_len &&
1815 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1818 /* Exit if v is smaller than both sons */
1819 if (smaller(tree, v, s->heap[j], s->depth)) break;
1821 /* Exchange v with the smallest son */
1822 s->heap[k] = s->heap[j]; k = j;
1824 /* And continue down the tree, setting j to the left son of k */
1830 /* ===========================================================================
1831 * Compute the optimal bit lengths for a tree and update the total bit length
1832 * for the current block.
1833 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1834 * above are the tree nodes sorted by increasing frequency.
1835 * OUT assertions: the field len is set to the optimal bit length, the
1836 * array bl_count contains the frequencies for each bit length.
1837 * The length opt_len is updated; static_len is also updated if stree is
1840 local void gen_bitlen(s, desc)
1842 tree_desc *desc; /* the tree descriptor */
1844 ct_data *tree = desc->dyn_tree;
1845 int max_code = desc->max_code;
1846 ct_data *stree = desc->stat_desc->static_tree;
1847 intf *extra = desc->stat_desc->extra_bits;
1848 int base = desc->stat_desc->extra_base;
1849 int max_length = desc->stat_desc->max_length;
1850 int h; /* heap index */
1851 int n, m; /* iterate over the tree elements */
1852 int bits; /* bit length */
1853 int xbits; /* extra bits */
1854 ush f; /* frequency */
1855 int overflow = 0; /* number of elements with bit length too large */
1857 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1859 /* In a first pass, compute the optimal bit lengths (which may
1860 * overflow in the case of the bit length tree).
1862 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1864 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1866 bits = tree[tree[n].Dad].Len + 1;
1867 if (bits > max_length) bits = max_length, overflow++;
1868 tree[n].Len = (ush)bits;
1869 /* We overwrite tree[n].Dad which is no longer needed */
1871 if (n > max_code) continue; /* not a leaf node */
1873 s->bl_count[bits]++;
1875 if (n >= base) xbits = extra[n-base];
1877 s->opt_len += (ulg)f * (bits + xbits);
1878 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1880 if (overflow == 0) return;
1882 Trace((stderr,"\nbit length overflow\n"));
1883 /* This happens for example on obj2 and pic of the Calgary corpus */
1885 /* Find the first bit length which could increase: */
1887 bits = max_length-1;
1888 while (s->bl_count[bits] == 0) bits--;
1889 s->bl_count[bits]--; /* move one leaf down the tree */
1890 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1891 s->bl_count[max_length]--;
1892 /* The brother of the overflow item also moves one step up,
1893 * but this does not affect bl_count[max_length]
1896 } while (overflow > 0);
1898 /* Now recompute all bit lengths, scanning in increasing frequency.
1899 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1900 * lengths instead of fixing only the wrong ones. This idea is taken
1901 * from 'ar' written by Haruhiko Okumura.)
1903 for (bits = max_length; bits != 0; bits--) {
1904 n = s->bl_count[bits];
1907 if (m > max_code) continue;
1908 if (tree[m].Len != (unsigned) bits) {
1909 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1910 s->opt_len += ((Long)bits - (Long)tree[m].Len)
1911 *(Long)tree[m].Freq;
1912 tree[m].Len = (ush)bits;
1919 /* ===========================================================================
1920 * Generate the codes for a given tree and bit counts (which need not be
1922 * IN assertion: the array bl_count contains the bit length statistics for
1923 * the given tree and the field len is set for all tree elements.
1924 * OUT assertion: the field code is set for all tree elements of non
1927 local void gen_codes (tree, max_code, bl_count)
1928 ct_data *tree; /* the tree to decorate */
1929 int max_code; /* largest code with non zero frequency */
1930 ushf *bl_count; /* number of codes at each bit length */
1932 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1933 ush code = 0; /* running code value */
1934 int bits; /* bit index */
1935 int n; /* code index */
1937 /* The distribution counts are first used to generate the code values
1938 * without bit reversal.
1940 for (bits = 1; bits <= MAX_BITS; bits++) {
1941 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1943 /* Check that the bit counts in bl_count are consistent. The last code
1946 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1947 "inconsistent bit counts");
1948 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1950 for (n = 0; n <= max_code; n++) {
1951 int len = tree[n].Len;
1952 if (len == 0) continue;
1953 /* Now reverse the bits */
1954 tree[n].Code = bi_reverse(next_code[len]++, len);
1956 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1957 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1961 /* ===========================================================================
1962 * Construct one Huffman tree and assigns the code bit strings and lengths.
1963 * Update the total bit length for the current block.
1964 * IN assertion: the field freq is set for all tree elements.
1965 * OUT assertions: the fields len and code are set to the optimal bit length
1966 * and corresponding code. The length opt_len is updated; static_len is
1967 * also updated if stree is not null. The field max_code is set.
1969 local void build_tree(s, desc)
1971 tree_desc *desc; /* the tree descriptor */
1973 ct_data *tree = desc->dyn_tree;
1974 ct_data *stree = desc->stat_desc->static_tree;
1975 int elems = desc->stat_desc->elems;
1976 int n, m; /* iterate over heap elements */
1977 int max_code = -1; /* largest code with non zero frequency */
1978 int node; /* new node being created */
1980 /* Construct the initial heap, with least frequent element in
1981 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
1982 * heap[0] is not used.
1984 s->heap_len = 0, s->heap_max = HEAP_SIZE;
1986 for (n = 0; n < elems; n++) {
1987 if (tree[n].Freq != 0) {
1988 s->heap[++(s->heap_len)] = max_code = n;
1995 /* The pkzip format requires that at least one distance code exists,
1996 * and that at least one bit should be sent even if there is only one
1997 * possible code. So to avoid special checks later on we force at least
1998 * two codes of non zero frequency.
2000 while (s->heap_len < 2) {
2001 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2002 tree[node].Freq = 1;
2004 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2005 /* node is 0 or 1 so it does not have extra bits */
2007 desc->max_code = max_code;
2009 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2010 * establish sub-heaps of increasing lengths:
2012 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2014 /* Construct the Huffman tree by repeatedly combining the least two
2017 node = elems; /* next internal node of the tree */
2019 pqremove(s, tree, n); /* n = node of least frequency */
2020 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2022 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2023 s->heap[--(s->heap_max)] = m;
2025 /* Create a new node father of n and m */
2026 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2027 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2028 tree[n].Dad = tree[m].Dad = (ush)node;
2030 if (tree == s->bl_tree) {
2031 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2032 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2035 /* and insert the new node in the heap */
2036 s->heap[SMALLEST] = node++;
2037 pqdownheap(s, tree, SMALLEST);
2039 } while (s->heap_len >= 2);
2041 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2043 /* At this point, the fields freq and dad are set. We can now
2044 * generate the bit lengths.
2046 gen_bitlen(s, (tree_desc *)desc);
2048 /* The field len is now set, we can generate the bit codes */
2049 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2052 /* ===========================================================================
2053 * Scan a literal or distance tree to determine the frequencies of the codes
2054 * in the bit length tree.
2056 local void scan_tree (s, tree, max_code)
2058 ct_data *tree; /* the tree to be scanned */
2059 int max_code; /* and its largest code of non zero frequency */
2061 int n; /* iterates over all tree elements */
2062 int prevlen = -1; /* last emitted length */
2063 int curlen; /* length of current code */
2064 int nextlen = tree[0].Len; /* length of next code */
2065 int count = 0; /* repeat count of the current code */
2066 int max_count = 7; /* max repeat count */
2067 int min_count = 4; /* min repeat count */
2069 if (nextlen == 0) max_count = 138, min_count = 3;
2070 tree[max_code+1].Len = (ush)0xffff; /* guard */
2072 for (n = 0; n <= max_code; n++) {
2073 curlen = nextlen; nextlen = tree[n+1].Len;
2074 if (++count < max_count && curlen == nextlen) {
2076 } else if (count < min_count) {
2077 s->bl_tree[curlen].Freq += count;
2078 } else if (curlen != 0) {
2079 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2080 s->bl_tree[REP_3_6].Freq++;
2081 } else if (count <= 10) {
2082 s->bl_tree[REPZ_3_10].Freq++;
2084 s->bl_tree[REPZ_11_138].Freq++;
2086 count = 0; prevlen = curlen;
2088 max_count = 138, min_count = 3;
2089 } else if (curlen == nextlen) {
2090 max_count = 6, min_count = 3;
2092 max_count = 7, min_count = 4;
2097 /* ===========================================================================
2098 * Send a literal or distance tree in compressed form, using the codes in
2101 local void send_tree (s, tree, max_code)
2103 ct_data *tree; /* the tree to be scanned */
2104 int max_code; /* and its largest code of non zero frequency */
2106 int n; /* iterates over all tree elements */
2107 int prevlen = -1; /* last emitted length */
2108 int curlen; /* length of current code */
2109 int nextlen = tree[0].Len; /* length of next code */
2110 int count = 0; /* repeat count of the current code */
2111 int max_count = 7; /* max repeat count */
2112 int min_count = 4; /* min repeat count */
2114 /* tree[max_code+1].Len = -1; */ /* guard already set */
2115 if (nextlen == 0) max_count = 138, min_count = 3;
2117 for (n = 0; n <= max_code; n++) {
2118 curlen = nextlen; nextlen = tree[n+1].Len;
2119 if (++count < max_count && curlen == nextlen) {
2121 } else if (count < min_count) {
2122 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2124 } else if (curlen != 0) {
2125 if (curlen != prevlen) {
2126 send_code(s, curlen, s->bl_tree); count--;
2128 Assert(count >= 3 && count <= 6, " 3_6?");
2129 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2131 } else if (count <= 10) {
2132 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2135 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2137 count = 0; prevlen = curlen;
2139 max_count = 138, min_count = 3;
2140 } else if (curlen == nextlen) {
2141 max_count = 6, min_count = 3;
2143 max_count = 7, min_count = 4;
2148 /* ===========================================================================
2149 * Construct the Huffman tree for the bit lengths and return the index in
2150 * bl_order of the last bit length code to send.
2152 local int build_bl_tree(s)
2155 int max_blindex; /* index of last bit length code of non zero freq */
2157 /* Determine the bit length frequencies for literal and distance trees */
2158 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2159 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2161 /* Build the bit length tree: */
2162 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2163 /* opt_len now includes the length of the tree representations, except
2164 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2167 /* Determine the number of bit length codes to send. The pkzip format
2168 * requires that at least 4 bit length codes be sent. (appnote.txt says
2169 * 3 but the actual value used is 4.)
2171 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2172 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2174 /* Update opt_len to include the bit length tree and counts */
2175 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2176 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2177 s->opt_len, s->static_len));
2182 /* ===========================================================================
2183 * Send the header for a block using dynamic Huffman trees: the counts, the
2184 * lengths of the bit length codes, the literal tree and the distance tree.
2185 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2187 local void send_all_trees(s, lcodes, dcodes, blcodes)
2189 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2191 int rank; /* index in bl_order */
2193 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2194 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2196 Tracev((stderr, "\nbl counts: "));
2197 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2198 send_bits(s, dcodes-1, 5);
2199 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2200 for (rank = 0; rank < blcodes; rank++) {
2201 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2202 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2204 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2206 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2207 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2209 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2210 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2213 /* ===========================================================================
2214 * Send a stored block
2216 local void ct_stored_block(s, buf, stored_len, eof)
2218 charf *buf; /* input block */
2219 ulg stored_len; /* length of input block */
2220 int eof; /* true if this is the last block for a file */
2222 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2223 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2224 s->compressed_len += (stored_len + 4) << 3;
2226 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2229 /* Send just the `stored block' type code without any length bytes or data.
2231 local void ct_stored_type_only(s)
2234 send_bits(s, (STORED_BLOCK << 1), 3);
2236 s->compressed_len = (s->compressed_len + 3) & ~7L;
2240 /* ===========================================================================
2241 * Send one empty static block to give enough lookahead for inflate.
2242 * This takes 10 bits, of which 7 may remain in the bit buffer.
2243 * The current inflate code requires 9 bits of lookahead. If the EOB
2244 * code for the previous block was coded on 5 bits or less, inflate
2245 * may have only 5+3 bits of lookahead to decode this EOB.
2246 * (There are no problems if the previous block is stored or fixed.)
2248 local void ct_align(s)
2251 send_bits(s, STATIC_TREES<<1, 3);
2252 send_code(s, END_BLOCK, static_ltree);
2253 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2255 /* Of the 10 bits for the empty block, we have already sent
2256 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2257 * block was thus its length plus what we have just sent.
2259 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2260 send_bits(s, STATIC_TREES<<1, 3);
2261 send_code(s, END_BLOCK, static_ltree);
2262 s->compressed_len += 10L;
2265 s->last_eob_len = 7;
2268 /* ===========================================================================
2269 * Determine the best encoding for the current block: dynamic trees, static
2270 * trees or store, and output the encoded block to the zip file. This function
2271 * returns the total compressed length for the file so far.
2273 local ulg ct_flush_block(s, buf, stored_len, flush)
2275 charf *buf; /* input block, or NULL if too old */
2276 ulg stored_len; /* length of input block */
2277 int flush; /* Z_FINISH if this is the last block for a file */
2279 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2280 int max_blindex; /* index of last bit length code of non zero freq */
2281 int eof = flush == Z_FINISH;
2283 ++s->blocks_in_packet;
2285 /* Check if the file is ascii or binary */
2286 if (s->data_type == UNKNOWN) set_data_type(s);
2288 /* Construct the literal and distance trees */
2289 build_tree(s, (tree_desc *)(&(s->l_desc)));
2290 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2293 build_tree(s, (tree_desc *)(&(s->d_desc)));
2294 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2296 /* At this point, opt_len and static_len are the total bit lengths of
2297 * the compressed block data, excluding the tree representations.
2300 /* Build the bit length tree for the above two trees, and get the index
2301 * in bl_order of the last bit length code to send.
2303 max_blindex = build_bl_tree(s);
2305 /* Determine the best encoding. Compute first the block length in bytes */
2306 opt_lenb = (s->opt_len+3+7)>>3;
2307 static_lenb = (s->static_len+3+7)>>3;
2309 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2310 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2313 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2315 /* If compression failed and this is the first and last block,
2316 * and if the .zip file can be seeked (to rewrite the local header),
2317 * the whole file is transformed into a stored file:
2319 #ifdef STORED_FILE_OK
2320 # ifdef FORCE_STORED_FILE
2321 if (eof && compressed_len == 0L) /* force stored file */
2323 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2326 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2327 if (buf == (charf*)0) error ("block vanished");
2329 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2330 s->compressed_len = stored_len << 3;
2333 #endif /* STORED_FILE_OK */
2336 if (buf != (char*)0) /* force stored block */
2338 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2339 /* 4: two words for the lengths */
2342 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2343 * Otherwise we can't have processed more than WSIZE input bytes since
2344 * the last block flush, because compression would have been
2345 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2346 * transform a block into a stored block.
2348 ct_stored_block(s, buf, stored_len, eof);
2352 if (static_lenb >= 0) /* force static trees */
2354 if (static_lenb == opt_lenb)
2357 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2358 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2359 s->compressed_len += 3 + s->static_len;
2361 send_bits(s, (DYN_TREES<<1)+eof, 3);
2362 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2364 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2365 s->compressed_len += 3 + s->opt_len;
2367 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2372 s->compressed_len += 7; /* align on byte boundary */
2374 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2375 s->compressed_len-7*eof));
2377 return s->compressed_len >> 3;
2380 /* ===========================================================================
2381 * Save the match info and tally the frequency counts. Return true if
2382 * the current block must be flushed.
2384 local int ct_tally (s, dist, lc)
2386 int dist; /* distance of matched string */
2387 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2389 s->d_buf[s->last_lit] = (ush)dist;
2390 s->l_buf[s->last_lit++] = (uch)lc;
2392 /* lc is the unmatched char */
2393 s->dyn_ltree[lc].Freq++;
2396 /* Here, lc is the match length - MIN_MATCH */
2397 dist--; /* dist = match distance - 1 */
2398 Assert((ush)dist < (ush)MAX_DIST(s) &&
2399 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2400 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2402 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2403 s->dyn_dtree[d_code(dist)].Freq++;
2406 /* Try to guess if it is profitable to stop the current block here */
2407 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2408 /* Compute an upper bound for the compressed length */
2409 ulg out_length = (ulg)s->last_lit*8L;
2410 ulg in_length = (ulg)s->strstart - s->block_start;
2412 for (dcode = 0; dcode < D_CODES; dcode++) {
2413 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2414 (5L+extra_dbits[dcode]);
2417 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2418 s->last_lit, in_length, out_length,
2419 100L - out_length*100L/in_length));
2420 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2422 return (s->last_lit == s->lit_bufsize-1);
2423 /* We avoid equality with lit_bufsize because of wraparound at 64K
2424 * on 16 bit machines and because stored blocks are restricted to
2429 /* ===========================================================================
2430 * Send the block data compressed using the given Huffman trees
2432 local void compress_block(s, ltree, dtree)
2434 ct_data *ltree; /* literal tree */
2435 ct_data *dtree; /* distance tree */
2437 unsigned dist; /* distance of matched string */
2438 int lc; /* match length or unmatched char (if dist == 0) */
2439 unsigned lx = 0; /* running index in l_buf */
2440 unsigned code; /* the code to send */
2441 int extra; /* number of extra bits to send */
2443 if (s->last_lit != 0) do {
2444 dist = s->d_buf[lx];
2445 lc = s->l_buf[lx++];
2447 send_code(s, lc, ltree); /* send a literal byte */
2448 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2450 /* Here, lc is the match length - MIN_MATCH */
2451 code = length_code[lc];
2452 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2453 extra = extra_lbits[code];
2455 lc -= base_length[code];
2456 send_bits(s, lc, extra); /* send the extra length bits */
2458 dist--; /* dist is now the match distance - 1 */
2459 code = d_code(dist);
2460 Assert (code < D_CODES, "bad d_code");
2462 send_code(s, code, dtree); /* send the distance code */
2463 extra = extra_dbits[code];
2465 dist -= base_dist[code];
2466 send_bits(s, dist, extra); /* send the extra distance bits */
2468 } /* literal or match pair ? */
2470 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2471 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2473 } while (lx < s->last_lit);
2475 send_code(s, END_BLOCK, ltree);
2476 s->last_eob_len = ltree[END_BLOCK].Len;
2479 /* ===========================================================================
2480 * Set the data type to ASCII or BINARY, using a crude approximation:
2481 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2482 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2483 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2485 local void set_data_type(s)
2489 unsigned ascii_freq = 0;
2490 unsigned bin_freq = 0;
2491 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2492 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2493 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2494 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2497 /* ===========================================================================
2498 * Reverse the first len bits of a code, using straightforward code (a faster
2499 * method would use a table)
2500 * IN assertion: 1 <= len <= 15
2502 local unsigned bi_reverse(code, len)
2503 unsigned code; /* the value to invert */
2504 int len; /* its bit length */
2506 register unsigned res = 0;
2509 code >>= 1, res <<= 1;
2510 } while (--len > 0);
2514 /* ===========================================================================
2515 * Flush the bit buffer, keeping at most 7 bits in it.
2517 local void bi_flush(s)
2520 if (s->bi_valid == 16) {
2521 put_short(s, s->bi_buf);
2524 } else if (s->bi_valid >= 8) {
2525 put_byte(s, (Byte)s->bi_buf);
2531 /* ===========================================================================
2532 * Flush the bit buffer and align the output on a byte boundary
2534 local void bi_windup(s)
2537 if (s->bi_valid > 8) {
2538 put_short(s, s->bi_buf);
2539 } else if (s->bi_valid > 0) {
2540 put_byte(s, (Byte)s->bi_buf);
2545 s->bits_sent = (s->bits_sent+7) & ~7;
2549 /* ===========================================================================
2550 * Copy a stored block, storing first the length and its
2551 * one's complement if requested.
2553 local void copy_block(s, buf, len, header)
2555 charf *buf; /* the input data */
2556 unsigned len; /* its length */
2557 int header; /* true if block header must be written */
2559 bi_windup(s); /* align on byte boundary */
2560 s->last_eob_len = 8; /* enough lookahead for inflate */
2563 put_short(s, (ush)len);
2564 put_short(s, (ush)~len);
2566 s->bits_sent += 2*16;
2570 s->bits_sent += (ulg)len<<3;
2573 put_byte(s, *buf++);
2579 /* infblock.h -- header to use infblock.c
2580 * Copyright (C) 1995 Mark Adler
2581 * For conditions of distribution and use, see copyright notice in zlib.h
2584 /* WARNING: this file should *not* be used by applications. It is
2585 part of the implementation of the compression library and is
2586 subject to change. Applications should only use zlib.h.
2589 struct inflate_blocks_state;
2590 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2592 local inflate_blocks_statef * inflate_blocks_new OF((
2594 check_func c, /* check function */
2595 uInt w)); /* window size */
2597 local int inflate_blocks OF((
2598 inflate_blocks_statef *,
2600 int)); /* initial return code */
2602 local void inflate_blocks_reset OF((
2603 inflate_blocks_statef *,
2605 uLongf *)); /* check value on output */
2607 local int inflate_blocks_free OF((
2608 inflate_blocks_statef *,
2610 uLongf *)); /* check value on output */
2612 local int inflate_addhistory OF((
2613 inflate_blocks_statef *,
2616 local int inflate_packet_flush OF((
2617 inflate_blocks_statef *));
2620 /* inftrees.h -- header to use inftrees.c
2621 * Copyright (C) 1995 Mark Adler
2622 * For conditions of distribution and use, see copyright notice in zlib.h
2625 /* WARNING: this file should *not* be used by applications. It is
2626 part of the implementation of the compression library and is
2627 subject to change. Applications should only use zlib.h.
2630 /* Huffman code lookup table entry--this entry is four bytes for machines
2631 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2633 typedef struct inflate_huft_s FAR inflate_huft;
2635 struct inflate_huft_s {
2638 Byte Exop; /* number of extra bits or operation */
2639 Byte Bits; /* number of bits in this code or subcode */
2641 uInt Nalloc; /* number of these allocated here */
2642 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2643 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2645 uInt Base; /* literal, length base, or distance base */
2646 inflate_huft *Next; /* pointer to next level of table */
2651 local uInt inflate_hufts;
2654 local int inflate_trees_bits OF((
2655 uIntf *, /* 19 code lengths */
2656 uIntf *, /* bits tree desired/actual depth */
2657 inflate_huft * FAR *, /* bits tree result */
2658 z_stream *)); /* for zalloc, zfree functions */
2660 local int inflate_trees_dynamic OF((
2661 uInt, /* number of literal/length codes */
2662 uInt, /* number of distance codes */
2663 uIntf *, /* that many (total) code lengths */
2664 uIntf *, /* literal desired/actual bit depth */
2665 uIntf *, /* distance desired/actual bit depth */
2666 inflate_huft * FAR *, /* literal/length tree result */
2667 inflate_huft * FAR *, /* distance tree result */
2668 z_stream *)); /* for zalloc, zfree functions */
2670 local int inflate_trees_fixed OF((
2671 uIntf *, /* literal desired/actual bit depth */
2672 uIntf *, /* distance desired/actual bit depth */
2673 inflate_huft * FAR *, /* literal/length tree result */
2674 inflate_huft * FAR *)); /* distance tree result */
2676 local int inflate_trees_free OF((
2677 inflate_huft *, /* tables to free */
2678 z_stream *)); /* for zfree function */
2682 /* infcodes.h -- header to use infcodes.c
2683 * Copyright (C) 1995 Mark Adler
2684 * For conditions of distribution and use, see copyright notice in zlib.h
2687 /* WARNING: this file should *not* be used by applications. It is
2688 part of the implementation of the compression library and is
2689 subject to change. Applications should only use zlib.h.
2692 struct inflate_codes_state;
2693 typedef struct inflate_codes_state FAR inflate_codes_statef;
2695 local inflate_codes_statef *inflate_codes_new OF((
2697 inflate_huft *, inflate_huft *,
2700 local int inflate_codes OF((
2701 inflate_blocks_statef *,
2705 local void inflate_codes_free OF((
2706 inflate_codes_statef *,
2711 /* inflate.c -- zlib interface to inflate modules
2712 * Copyright (C) 1995 Mark Adler
2713 * For conditions of distribution and use, see copyright notice in zlib.h
2716 /* inflate private state */
2717 struct internal_state {
2721 METHOD, /* waiting for method byte */
2722 FLAG, /* waiting for flag byte */
2723 BLOCKS, /* decompressing blocks */
2724 CHECK4, /* four check bytes to go */
2725 CHECK3, /* three check bytes to go */
2726 CHECK2, /* two check bytes to go */
2727 CHECK1, /* one check byte to go */
2728 DONE, /* finished check, done */
2729 ZBAD} /* got an error--stay here */
2730 mode; /* current inflate mode */
2732 /* mode dependent information */
2734 uInt method; /* if FLAGS, method byte */
2736 uLong was; /* computed check value */
2737 uLong need; /* stream check value */
2738 } check; /* if CHECK, check values to compare */
2739 uInt marker; /* if ZBAD, inflateSync's marker bytes count */
2740 } sub; /* submode */
2742 /* mode independent information */
2743 int nowrap; /* flag for no wrapper */
2744 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2745 inflate_blocks_statef
2746 *blocks; /* current inflate_blocks state */
2756 if (z == Z_NULL || z->state == Z_NULL)
2757 return Z_STREAM_ERROR;
2758 z->total_in = z->total_out = 0;
2760 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2761 inflate_blocks_reset(z->state->blocks, z, &c);
2762 Trace((stderr, "inflate: reset\n"));
2772 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2773 return Z_STREAM_ERROR;
2774 if (z->state->blocks != Z_NULL)
2775 inflate_blocks_free(z->state->blocks, z, &c);
2776 ZFREE(z, z->state, sizeof(struct internal_state));
2778 Trace((stderr, "inflate: end\n"));
2783 int inflateInit2(z, w)
2787 /* initialize state */
2789 return Z_STREAM_ERROR;
2790 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2791 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2792 if ((z->state = (struct internal_state FAR *)
2793 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2795 z->state->blocks = Z_NULL;
2797 /* handle undocumented nowrap option (no zlib header or check) */
2798 z->state->nowrap = 0;
2802 z->state->nowrap = 1;
2805 /* set window size */
2806 if (w < 8 || w > 15)
2809 return Z_STREAM_ERROR;
2811 z->state->wbits = (uInt)w;
2813 /* create inflate_blocks state */
2814 if ((z->state->blocks =
2815 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2821 Trace((stderr, "inflate: allocated\n"));
2832 return inflateInit2(z, DEF_WBITS);
2836 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2837 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2846 if (z == Z_NULL || z->next_in == Z_NULL)
2847 return Z_STREAM_ERROR;
2849 while (1) switch (z->state->mode)
2853 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2855 z->state->mode = ZBAD;
2856 z->msg = "unknown compression method";
2857 z->state->sub.marker = 5; /* can't try inflateSync */
2860 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2862 z->state->mode = ZBAD;
2863 z->msg = "invalid window size";
2864 z->state->sub.marker = 5; /* can't try inflateSync */
2867 z->state->mode = FLAG;
2870 if ((b = NEXTBYTE) & 0x20)
2872 z->state->mode = ZBAD;
2873 z->msg = "invalid reserved bit";
2874 z->state->sub.marker = 5; /* can't try inflateSync */
2877 if (((z->state->sub.method << 8) + b) % 31)
2879 z->state->mode = ZBAD;
2880 z->msg = "incorrect header check";
2881 z->state->sub.marker = 5; /* can't try inflateSync */
2884 Trace((stderr, "inflate: zlib header ok\n"));
2885 z->state->mode = BLOCKS;
2887 r = inflate_blocks(z->state->blocks, z, r);
2888 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2889 r = inflate_packet_flush(z->state->blocks);
2890 if (r == Z_DATA_ERROR)
2892 z->state->mode = ZBAD;
2893 z->state->sub.marker = 0; /* can try inflateSync */
2896 if (r != Z_STREAM_END)
2899 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2900 if (z->state->nowrap)
2902 z->state->mode = DONE;
2905 z->state->mode = CHECK4;
2908 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2909 z->state->mode = CHECK3;
2912 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2913 z->state->mode = CHECK2;
2916 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2917 z->state->mode = CHECK1;
2920 z->state->sub.check.need += (uLong)NEXTBYTE;
2922 if (z->state->sub.check.was != z->state->sub.check.need)
2924 z->state->mode = ZBAD;
2925 z->msg = "incorrect data check";
2926 z->state->sub.marker = 5; /* can't try inflateSync */
2929 Trace((stderr, "inflate: zlib check ok\n"));
2930 z->state->mode = DONE;
2932 return Z_STREAM_END;
2934 return Z_DATA_ERROR;
2936 return Z_STREAM_ERROR;
2940 if (f != Z_PACKET_FLUSH)
2942 z->state->mode = ZBAD;
2943 z->state->sub.marker = 0; /* can try inflateSync */
2944 return Z_DATA_ERROR;
2948 * This subroutine adds the data at next_in/avail_in to the output history
2949 * without performing any output. The output buffer must be "caught up";
2950 * i.e. no pending output (hence s->read equals s->write), and the state must
2951 * be BLOCKS (i.e. we should be willing to see the start of a series of
2952 * BLOCKS). On exit, the output will also be caught up, and the checksum
2953 * will have been updated if need be.
2956 int inflateIncomp(z)
2959 if (z->state->mode != BLOCKS)
2960 return Z_DATA_ERROR;
2961 return inflate_addhistory(z->state->blocks, z);
2968 uInt n; /* number of bytes to look at */
2969 Bytef *p; /* pointer to bytes */
2970 uInt m; /* number of marker bytes found in a row */
2971 uLong r, w; /* temporaries to save total_in and total_out */
2974 if (z == Z_NULL || z->state == Z_NULL)
2975 return Z_STREAM_ERROR;
2976 if (z->state->mode != ZBAD)
2978 z->state->mode = ZBAD;
2979 z->state->sub.marker = 0;
2981 if ((n = z->avail_in) == 0)
2984 m = z->state->sub.marker;
2989 if (*p == (Byte)(m < 2 ? 0 : 0xff))
2999 z->total_in += p - z->next_in;
3002 z->state->sub.marker = m;
3004 /* return no joy or set up to restart on a new block */
3006 return Z_DATA_ERROR;
3007 r = z->total_in; w = z->total_out;
3009 z->total_in = r; z->total_out = w;
3010 z->state->mode = BLOCKS;
3018 /* infutil.h -- types and macros common to blocks and codes
3019 * Copyright (C) 1995 Mark Adler
3020 * For conditions of distribution and use, see copyright notice in zlib.h
3023 /* WARNING: this file should *not* be used by applications. It is
3024 part of the implementation of the compression library and is
3025 subject to change. Applications should only use zlib.h.
3028 /* inflate blocks semi-private state */
3029 struct inflate_blocks_state {
3033 TYPE, /* get type bits (3, including end bit) */
3034 LENS, /* get lengths for stored */
3035 STORED, /* processing stored block */
3036 TABLE, /* get table lengths */
3037 BTREE, /* get bit lengths tree for a dynamic block */
3038 DTREE, /* get length, distance trees for a dynamic block */
3039 CODES, /* processing fixed or dynamic block */
3040 DRY, /* output remaining window bytes */
3041 DONEB, /* finished last block, done */
3042 BADB} /* got a data error--stuck here */
3043 mode; /* current inflate_block mode */
3045 /* mode dependent information */
3047 uInt left; /* if STORED, bytes left to copy */
3049 uInt table; /* table lengths (14 bits) */
3050 uInt index; /* index into blens (or border) */
3051 uIntf *blens; /* bit lengths of codes */
3052 uInt bb; /* bit length tree depth */
3053 inflate_huft *tb; /* bit length decoding tree */
3054 int nblens; /* # elements allocated at blens */
3055 } trees; /* if DTREE, decoding info for trees */
3057 inflate_huft *tl, *td; /* trees to free */
3058 inflate_codes_statef
3060 } decode; /* if CODES, current state */
3061 } sub; /* submode */
3062 uInt last; /* true if this block is the last block */
3064 /* mode independent information */
3065 uInt bitk; /* bits in bit buffer */
3066 uLong bitb; /* bit buffer */
3067 Bytef *window; /* sliding window */
3068 Bytef *end; /* one byte after sliding window */
3069 Bytef *read; /* window read pointer */
3070 Bytef *write; /* window write pointer */
3071 check_func checkfn; /* check function */
3072 uLong check; /* check on output */
3077 /* defines for inflate input/output */
3078 /* update pointers and return */
3079 #define UPDBITS {s->bitb=b;s->bitk=k;}
3080 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3081 #define UPDOUT {s->write=q;}
3082 #define UPDATE {UPDBITS UPDIN UPDOUT}
3083 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3084 /* get bytes and bits */
3085 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3086 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3087 #define NEXTBYTE (n--,*p++)
3088 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3089 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3091 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3092 #define LOADOUT {q=s->write;m=WAVAIL;}
3093 #define ZWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3094 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3095 #define NEEDOUT {if(m==0){ZWRAP if(m==0){FLUSH ZWRAP if(m==0) LEAVE}}r=Z_OK;}
3096 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3097 /* load local pointers */
3098 #define LOAD {LOADIN LOADOUT}
3100 /* And'ing with mask[n] masks the lower n bits */
3101 local uInt inflate_mask[] = {
3103 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3104 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3107 /* copy as much as possible from the sliding window to the output area */
3108 local int inflate_flush OF((
3109 inflate_blocks_statef *,
3114 /* inffast.h -- header to use inffast.c
3115 * Copyright (C) 1995 Mark Adler
3116 * For conditions of distribution and use, see copyright notice in zlib.h
3119 /* WARNING: this file should *not* be used by applications. It is
3120 part of the implementation of the compression library and is
3121 subject to change. Applications should only use zlib.h.
3124 local int inflate_fast OF((
3129 inflate_blocks_statef *,
3134 /* infblock.c -- interpret and process block types to last block
3135 * Copyright (C) 1995 Mark Adler
3136 * For conditions of distribution and use, see copyright notice in zlib.h
3139 /* Table for deflate from PKZIP's appnote.txt. */
3140 local uInt border[] = { /* Order of the bit length code lengths */
3141 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3144 Notes beyond the 1.93a appnote.txt:
3146 1. Distance pointers never point before the beginning of the output
3148 2. Distance pointers can point back across blocks, up to 32k away.
3149 3. There is an implied maximum of 7 bits for the bit length table and
3150 15 bits for the actual data.
3151 4. If only one code exists, then it is encoded using one bit. (Zero
3152 would be more efficient, but perhaps a little confusing.) If two
3153 codes exist, they are coded using one bit each (0 and 1).
3154 5. There is no way of sending zero distance codes--a dummy must be
3155 sent if there are none. (History: a pre 2.0 version of PKZIP would
3156 store blocks with no distance codes, but this was discovered to be
3157 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3158 zero distance codes, which is sent as one code of zero bits in
3160 6. There are up to 286 literal/length codes. Code 256 represents the
3161 end-of-block. Note however that the static length tree defines
3162 288 codes just to fill out the Huffman codes. Codes 286 and 287
3163 cannot be used though, since there is no length base or extra bits
3164 defined for them. Similarily, there are up to 30 distance codes.
3165 However, static trees define 32 codes (all 5 bits) to fill out the
3166 Huffman codes, but the last two had better not show up in the data.
3167 7. Unzip can check dynamic Huffman blocks for complete code sets.
3168 The exception is that a single code would not be complete (see #4).
3169 8. The five bits following the block type is really the number of
3170 literal codes sent minus 257.
3171 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3172 (1+6+6). Therefore, to output three times the length, you output
3173 three codes (1+1+1), whereas to output four times the same length,
3174 you only need two codes (1+3). Hmm.
3175 10. In the tree reconstruction algorithm, Code = Code + Increment
3176 only if BitLength(i) is not zero. (Pretty obvious.)
3177 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3178 12. Note: length code 284 can represent 227-258, but length code 285
3179 really is 258. The last length deserves its own, short code
3180 since it gets used a lot in very redundant files. The length
3181 258 is special since 258 - 3 (the min match length) is 255.
3182 13. The literal/length and distance code bit lengths are read as a
3183 single stream of lengths. It is possible (and advantageous) for
3184 a repeat code (16, 17, or 18) to go across the boundary between
3185 the two sets of lengths.
3189 local void inflate_blocks_reset(s, z, c)
3190 inflate_blocks_statef *s;
3194 if (s->checkfn != Z_NULL)
3196 if (s->mode == BTREE || s->mode == DTREE)
3197 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3198 if (s->mode == CODES)
3200 inflate_codes_free(s->sub.decode.codes, z);
3201 inflate_trees_free(s->sub.decode.td, z);
3202 inflate_trees_free(s->sub.decode.tl, z);
3207 s->read = s->write = s->window;
3208 if (s->checkfn != Z_NULL)
3209 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3210 Trace((stderr, "inflate: blocks reset\n"));
3214 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
3219 inflate_blocks_statef *s;
3221 if ((s = (inflate_blocks_statef *)ZALLOC
3222 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3224 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3226 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3229 s->end = s->window + w;
3232 Trace((stderr, "inflate: blocks allocated\n"));
3233 inflate_blocks_reset(s, z, &s->check);
3238 local int inflate_blocks(s, z, r)
3239 inflate_blocks_statef *s;
3243 uInt t; /* temporary storage */
3244 uLong b; /* bit buffer */
3245 uInt k; /* bits in bit buffer */
3246 Bytef *p; /* input data pointer */
3247 uInt n; /* bytes available there */
3248 Bytef *q; /* output window write pointer */
3249 uInt m; /* bytes to end of window or read pointer */
3251 /* copy input/output information to locals (UPDATE macro restores) */
3254 /* process input based on current state */
3255 while (1) switch (s->mode)
3263 case 0: /* stored */
3264 Trace((stderr, "inflate: stored block%s\n",
3265 s->last ? " (last)" : ""));
3267 t = k & 7; /* go to byte boundary */
3269 s->mode = LENS; /* get length of stored block */
3272 Trace((stderr, "inflate: fixed codes block%s\n",
3273 s->last ? " (last)" : ""));
3276 inflate_huft *tl, *td;
3278 inflate_trees_fixed(&bl, &bd, &tl, &td);
3279 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3280 if (s->sub.decode.codes == Z_NULL)
3285 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3286 s->sub.decode.td = Z_NULL;
3291 case 2: /* dynamic */
3292 Trace((stderr, "inflate: dynamic codes block%s\n",
3293 s->last ? " (last)" : ""));
3297 case 3: /* illegal */
3300 z->msg = "invalid block type";
3307 if (((~b) >> 16) != (b & 0xffff))
3310 z->msg = "invalid stored block lengths";
3314 s->sub.left = (uInt)b & 0xffff;
3315 b = k = 0; /* dump bits */
3316 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3317 s->mode = s->sub.left ? STORED : TYPE;
3329 if ((s->sub.left -= t) != 0)
3331 Tracev((stderr, "inflate: stored end, %lu total out\n",
3332 z->total_out + (q >= s->read ? q - s->read :
3333 (s->end - s->read) + (q - s->window))));
3334 s->mode = s->last ? DRY : TYPE;
3338 s->sub.trees.table = t = (uInt)b & 0x3fff;
3339 #ifndef PKZIP_BUG_WORKAROUND
3340 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3343 z->msg = "too many length or distance symbols";
3348 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3351 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3356 s->sub.trees.nblens = t;
3358 s->sub.trees.index = 0;
3359 Tracev((stderr, "inflate: table sizes ok\n"));
3362 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3365 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3368 while (s->sub.trees.index < 19)
3369 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3370 s->sub.trees.bb = 7;
3371 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3372 &s->sub.trees.tb, z);
3376 if (r == Z_DATA_ERROR)
3380 s->sub.trees.index = 0;
3381 Tracev((stderr, "inflate: bits tree ok\n"));
3384 while (t = s->sub.trees.table,
3385 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3390 t = s->sub.trees.bb;
3392 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3393 t = h->word.what.Bits;
3398 s->sub.trees.blens[s->sub.trees.index++] = c;
3400 else /* c == 16..18 */
3402 i = c == 18 ? 7 : c - 14;
3403 j = c == 18 ? 11 : 3;
3406 j += (uInt)b & inflate_mask[i];
3408 i = s->sub.trees.index;
3409 t = s->sub.trees.table;
3410 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3414 z->msg = "invalid bit length repeat";
3418 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3420 s->sub.trees.blens[i++] = c;
3422 s->sub.trees.index = i;
3425 inflate_trees_free(s->sub.trees.tb, z);
3426 s->sub.trees.tb = Z_NULL;
3429 inflate_huft *tl, *td;
3430 inflate_codes_statef *c;
3432 bl = 9; /* must be <= 9 for lookahead assumptions */
3433 bd = 6; /* must be <= 9 for lookahead assumptions */
3434 t = s->sub.trees.table;
3435 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3436 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3439 if (t == (uInt)Z_DATA_ERROR)
3444 Tracev((stderr, "inflate: trees ok\n"));
3445 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3447 inflate_trees_free(td, z);
3448 inflate_trees_free(tl, z);
3452 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3453 s->sub.decode.codes = c;
3454 s->sub.decode.tl = tl;
3455 s->sub.decode.td = td;
3460 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3461 return inflate_flush(s, z, r);
3463 inflate_codes_free(s->sub.decode.codes, z);
3464 inflate_trees_free(s->sub.decode.td, z);
3465 inflate_trees_free(s->sub.decode.tl, z);
3467 Tracev((stderr, "inflate: codes end, %lu total out\n",
3468 z->total_out + (q >= s->read ? q - s->read :
3469 (s->end - s->read) + (q - s->window))));
3475 if (k > 7) /* return unused byte, if any */
3477 Assert(k < 16, "inflate_codes grabbed too many bytes")
3480 p--; /* can always return one */
3485 if (s->read != s->write)
3501 local int inflate_blocks_free(s, z, c)
3502 inflate_blocks_statef *s;
3506 inflate_blocks_reset(s, z, c);
3507 ZFREE(z, s->window, s->end - s->window);
3508 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3509 Trace((stderr, "inflate: blocks freed\n"));
3514 * This subroutine adds the data at next_in/avail_in to the output history
3515 * without performing any output. The output buffer must be "caught up";
3516 * i.e. no pending output (hence s->read equals s->write), and the state must
3517 * be BLOCKS (i.e. we should be willing to see the start of a series of
3518 * BLOCKS). On exit, the output will also be caught up, and the checksum
3519 * will have been updated if need be.
3521 local int inflate_addhistory(s, z)
3522 inflate_blocks_statef *s;
3525 uLong b; /* bit buffer */ /* NOT USED HERE */
3526 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3527 uInt t; /* temporary storage */
3528 Bytef *p; /* input data pointer */
3529 uInt n; /* bytes available there */
3530 Bytef *q; /* output window write pointer */
3531 uInt m; /* bytes to end of window or read pointer */
3533 if (s->read != s->write)
3534 return Z_STREAM_ERROR;
3535 if (s->mode != TYPE)
3536 return Z_DATA_ERROR;
3538 /* we're ready to rock */
3540 /* while there is input ready, copy to output buffer, moving
3541 * pointers as needed.
3544 t = n; /* how many to do */
3545 /* is there room until end of buffer? */
3547 /* update check information */
3548 if (s->checkfn != Z_NULL)
3549 s->check = (*s->checkfn)(s->check, q, t);
3555 s->read = q; /* drag read pointer forward */
3556 /* ZWRAP */ /* expand ZWRAP macro by hand to handle s->read */
3558 s->read = q = s->window;
3568 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3569 * a `stored' block type value but not the (zero) length bytes.
3571 local int inflate_packet_flush(s)
3572 inflate_blocks_statef *s;
3574 if (s->mode != LENS)
3575 return Z_DATA_ERROR;
3582 /* inftrees.c -- generate Huffman trees for efficient decoding
3583 * Copyright (C) 1995 Mark Adler
3584 * For conditions of distribution and use, see copyright notice in zlib.h
3587 /* simplify the use of the inflate_huft type with some defines */
3588 #define base more.Base
3589 #define next more.Next
3590 #define exop word.what.Exop
3591 #define bits word.what.Bits
3594 local int huft_build OF((
3595 uIntf *, /* code lengths in bits */
3596 uInt, /* number of codes */
3597 uInt, /* number of "simple" codes */
3598 uIntf *, /* list of base values for non-simple codes */
3599 uIntf *, /* list of extra bits for non-simple codes */
3600 inflate_huft * FAR*,/* result: starting table */
3601 uIntf *, /* maximum lookup bits (returns actual) */
3602 z_stream *)); /* for zalloc function */
3604 local voidpf falloc OF((
3605 voidpf, /* opaque pointer (not used) */
3606 uInt, /* number of items */
3607 uInt)); /* size of item */
3609 local void ffree OF((
3610 voidpf q, /* opaque pointer (not used) */
3611 voidpf p, /* what to free (not used) */
3612 uInt n)); /* number of bytes (not used) */
3614 /* Tables for deflate from PKZIP's appnote.txt. */
3615 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3616 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3617 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3618 /* actually lengths - 2; also see note #13 above about 258 */
3619 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3620 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3621 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3622 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3623 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3624 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3625 8193, 12289, 16385, 24577};
3626 local uInt cpdext[] = { /* Extra bits for distance codes */
3627 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3628 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3632 Huffman code decoding is performed using a multi-level table lookup.
3633 The fastest way to decode is to simply build a lookup table whose
3634 size is determined by the longest code. However, the time it takes
3635 to build this table can also be a factor if the data being decoded
3636 is not very long. The most common codes are necessarily the
3637 shortest codes, so those codes dominate the decoding time, and hence
3638 the speed. The idea is you can have a shorter table that decodes the
3639 shorter, more probable codes, and then point to subsidiary tables for
3640 the longer codes. The time it costs to decode the longer codes is
3641 then traded against the time it takes to make longer tables.
3643 This results of this trade are in the variables lbits and dbits
3644 below. lbits is the number of bits the first level table for literal/
3645 length codes can decode in one step, and dbits is the same thing for
3646 the distance codes. Subsequent tables are also less than or equal to
3647 those sizes. These values may be adjusted either when all of the
3648 codes are shorter than that, in which case the longest code length in
3649 bits is used, or when the shortest code is *longer* than the requested
3650 table size, in which case the length of the shortest code in bits is
3653 There are two different values for the two tables, since they code a
3654 different number of possibilities each. The literal/length table
3655 codes 286 possible values, or in a flat code, a little over eight
3656 bits. The distance table codes 30 possible values, or a little less
3657 than five bits, flat. The optimum values for speed end up being
3658 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3659 The optimum values may differ though from machine to machine, and
3660 possibly even between compilers. Your mileage may vary.
3664 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3665 #define BMAX 15 /* maximum bit length of any code */
3666 #define N_MAX 288 /* maximum number of codes in any set */
3672 local int huft_build(b, n, s, d, e, t, m, zs)
3673 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3674 uInt n; /* number of codes (assumed <= N_MAX) */
3675 uInt s; /* number of simple-valued codes (0..s-1) */
3676 uIntf *d; /* list of base values for non-simple codes */
3677 uIntf *e; /* list of extra bits for non-simple codes */
3678 inflate_huft * FAR *t; /* result: starting table */
3679 uIntf *m; /* maximum lookup bits, returns actual */
3680 z_stream *zs; /* for zalloc function */
3681 /* Given a list of code lengths and a maximum table size, make a set of
3682 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3683 if the given code set is incomplete (the tables are still built in this
3684 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3685 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3688 uInt a; /* counter for codes of length k */
3689 uInt c[BMAX+1]; /* bit length count table */
3690 uInt f; /* i repeats in table every f entries */
3691 int g; /* maximum code length */
3692 int h; /* table level */
3693 register uInt i; /* counter, current code */
3694 register uInt j; /* counter */
3695 register int k; /* number of bits in current code */
3696 int l; /* bits per table (returned in m) */
3697 register uIntf *p; /* pointer into c[], b[], or v[] */
3698 inflate_huft *q; /* points to current table */
3699 struct inflate_huft_s r; /* table entry for structure assignment */
3700 inflate_huft *u[BMAX]; /* table stack */
3701 uInt v[N_MAX]; /* values in order of bit length */
3702 register int w; /* bits before this table == (l * h) */
3703 uInt x[BMAX+1]; /* bit offsets, then code stack */
3704 uIntf *xp; /* pointer into x */
3705 int y; /* number of dummy codes added */
3706 uInt z; /* number of entries in current table */
3709 /* Generate counts for each bit length */
3711 #define C0 *p++ = 0;
3712 #define C2 C0 C0 C0 C0
3713 #define C4 C2 C2 C2 C2
3714 C4 /* clear c[]--assume BMAX+1 is 16 */
3717 c[*p++]++; /* assume all entries <= BMAX */
3719 if (c[0] == n) /* null input--all zero length codes */
3721 *t = (inflate_huft *)Z_NULL;
3727 /* Find minimum and maximum length, bound *m by those */
3729 for (j = 1; j <= BMAX; j++)
3732 k = j; /* minimum code length */
3735 for (i = BMAX; i; i--)
3738 g = i; /* maximum code length */
3744 /* Adjust last length count to fill out codes, if needed */
3745 for (y = 1 << j; j < i; j++, y <<= 1)
3746 if ((y -= c[j]) < 0)
3747 return Z_DATA_ERROR;
3748 if ((y -= c[i]) < 0)
3749 return Z_DATA_ERROR;
3753 /* Generate starting offsets into the value table for each length */
3755 p = c + 1; xp = x + 2;
3756 while (--i) { /* note that i == g from above */
3757 *xp++ = (j += *p++);
3761 /* Make a table of values in order of bit lengths */
3764 if ((j = *p++) != 0)
3769 /* Generate the Huffman codes and for each, make the table entries */
3770 x[0] = i = 0; /* first Huffman code is zero */
3771 p = v; /* grab values in bit order */
3772 h = -1; /* no tables yet--level -1 */
3773 w = -l; /* bits decoded == (l * h) */
3774 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3775 q = (inflate_huft *)Z_NULL; /* ditto */
3778 /* go through the bit lengths (k already is bits in shortest code) */
3784 /* here i is the Huffman code of length k bits for value *p */
3785 /* make tables up to required level */
3789 w += l; /* previous table always l bits */
3791 /* compute minimum size table less than or equal to l bits */
3792 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3793 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3794 { /* too few codes for k-w bit table */
3795 f -= a + 1; /* deduct codes from patterns left */
3798 while (++j < z) /* try smaller tables up to z bits */
3800 if ((f <<= 1) <= *++xp)
3801 break; /* enough codes to use up j bits */
3802 f -= *xp; /* else deduct codes from patterns */
3805 z = 1 << j; /* table entries for j-bit table */
3807 /* allocate and link in new table */
3808 if ((q = (inflate_huft *)ZALLOC
3809 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3812 inflate_trees_free(u[0], zs);
3813 return Z_MEM_ERROR; /* not enough memory */
3815 q->word.Nalloc = z + 1;
3817 inflate_hufts += z + 1;
3819 *t = q + 1; /* link to list for huft_free() */
3820 *(t = &(q->next)) = Z_NULL;
3821 u[h] = ++q; /* table starts after link */
3823 /* connect to last table, if there is one */
3826 x[h] = i; /* save pattern for backing up */
3827 r.bits = (Byte)l; /* bits to dump before this table */
3828 r.exop = (Byte)j; /* bits in this table */
3829 r.next = q; /* pointer to this table */
3830 j = i >> (w - l); /* (get around Turbo C bug) */
3831 u[h-1][j] = r; /* connect to last table */
3835 /* set up table entry in r */
3836 r.bits = (Byte)(k - w);
3838 r.exop = 128 + 64; /* out of values--invalid code */
3841 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3842 r.base = *p++; /* simple code is just the value */
3846 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3847 r.base = d[*p++ - s];
3850 /* fill code-like entries with r */
3852 for (j = i >> w; j < z; j += f)
3855 /* backwards increment the k-bit code i */
3856 for (j = 1 << (k - 1); i & j; j >>= 1)
3860 /* backup over finished tables */
3861 while ((i & ((1 << w) - 1)) != x[h])
3863 h--; /* don't need to update q */
3870 /* Return Z_BUF_ERROR if we were given an incomplete table */
3871 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3875 local int inflate_trees_bits(c, bb, tb, z)
3876 uIntf *c; /* 19 code lengths */
3877 uIntf *bb; /* bits tree desired/actual depth */
3878 inflate_huft * FAR *tb; /* bits tree result */
3879 z_stream *z; /* for zfree function */
3883 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3884 if (r == Z_DATA_ERROR)
3885 z->msg = "oversubscribed dynamic bit lengths tree";
3886 else if (r == Z_BUF_ERROR)
3888 inflate_trees_free(*tb, z);
3889 z->msg = "incomplete dynamic bit lengths tree";
3896 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3897 uInt nl; /* number of literal/length codes */
3898 uInt nd; /* number of distance codes */
3899 uIntf *c; /* that many (total) code lengths */
3900 uIntf *bl; /* literal desired/actual bit depth */
3901 uIntf *bd; /* distance desired/actual bit depth */
3902 inflate_huft * FAR *tl; /* literal/length tree result */
3903 inflate_huft * FAR *td; /* distance tree result */
3904 z_stream *z; /* for zfree function */
3908 /* build literal/length tree */
3909 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3911 if (r == Z_DATA_ERROR)
3912 z->msg = "oversubscribed literal/length tree";
3913 else if (r == Z_BUF_ERROR)
3915 inflate_trees_free(*tl, z);
3916 z->msg = "incomplete literal/length tree";
3922 /* build distance tree */
3923 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3925 if (r == Z_DATA_ERROR)
3926 z->msg = "oversubscribed literal/length tree";
3927 else if (r == Z_BUF_ERROR) {
3928 #ifdef PKZIP_BUG_WORKAROUND
3932 inflate_trees_free(*td, z);
3933 z->msg = "incomplete literal/length tree";
3936 inflate_trees_free(*tl, z);
3946 /* build fixed tables only once--keep them here */
3947 #ifdef MULTI_THREADED
3948 local volatile int fixed_lock = 0;
3950 local int fixed_built = 0;
3951 #define FIXEDH 530 /* number of hufts used by fixed tables */
3952 local uInt fixed_left = FIXEDH;
3953 local inflate_huft fixed_mem[FIXEDH];
3954 local uInt fixed_bl;
3955 local uInt fixed_bd;
3956 local inflate_huft *fixed_tl;
3957 local inflate_huft *fixed_td;
3960 local voidpf falloc(q, n, s)
3961 voidpf q; /* opaque pointer (not used) */
3962 uInt n; /* number of items */
3963 uInt s; /* size of item */
3965 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
3966 "inflate_trees falloc overflow");
3967 if (q) s++; /* to make some compilers happy */
3969 return (voidpf)(fixed_mem + fixed_left);
3973 local void ffree(q, p, n)
3978 Assert(0, "inflate_trees ffree called!");
3979 if (q) q = p; /* to make some compilers happy */
3983 local int inflate_trees_fixed(bl, bd, tl, td)
3984 uIntf *bl; /* literal desired/actual bit depth */
3985 uIntf *bd; /* distance desired/actual bit depth */
3986 inflate_huft * FAR *tl; /* literal/length tree result */
3987 inflate_huft * FAR *td; /* distance tree result */
3989 /* build fixed tables if not built already--lock out other instances */
3990 #ifdef MULTI_THREADED
3991 while (++fixed_lock > 1)
3996 int k; /* temporary variable */
3997 unsigned c[288]; /* length list for huft_build */
3998 z_stream z; /* for falloc function */
4000 /* set up fake z_stream for memory routines */
4006 for (k = 0; k < 144; k++)
4008 for (; k < 256; k++)
4010 for (; k < 280; k++)
4012 for (; k < 288; k++)
4015 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4017 /* distance table */
4018 for (k = 0; k < 30; k++)
4021 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4026 #ifdef MULTI_THREADED
4037 local int inflate_trees_free(t, z)
4038 inflate_huft *t; /* table to free */
4039 z_stream *z; /* for zfree function */
4040 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4041 list of the tables it made, with the links in a dummy first entry of
4044 register inflate_huft *p, *q;
4046 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4051 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4058 /* infcodes.c -- process literals and length/distance pairs
4059 * Copyright (C) 1995 Mark Adler
4060 * For conditions of distribution and use, see copyright notice in zlib.h
4063 /* simplify the use of the inflate_huft type with some defines */
4064 #define base more.Base
4065 #define next more.Next
4066 #define exop word.what.Exop
4067 #define bits word.what.Bits
4069 /* inflate codes private state */
4070 struct inflate_codes_state {
4073 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4074 START, /* x: set up for LEN */
4075 LEN, /* i: get length/literal/eob next */
4076 LENEXT, /* i: getting length extra (have base) */
4077 DIST, /* i: get distance next */
4078 DISTEXT, /* i: getting distance extra */
4079 COPY, /* o: copying bytes in window, waiting for space */
4080 LIT, /* o: got literal, waiting for output space */
4081 WASH, /* o: got eob, possibly still output waiting */
4082 END, /* x: got eob and all data flushed */
4083 BADCODE} /* x: got error */
4084 mode; /* current inflate_codes mode */
4086 /* mode dependent information */
4090 inflate_huft *tree; /* pointer into tree */
4091 uInt need; /* bits needed */
4092 } code; /* if LEN or DIST, where in tree */
4093 uInt lit; /* if LIT, literal */
4095 uInt get; /* bits to get for extra */
4096 uInt dist; /* distance back to copy from */
4097 } copy; /* if EXT or COPY, where and how much */
4098 } sub; /* submode */
4100 /* mode independent information */
4101 Byte lbits; /* ltree bits decoded per branch */
4102 Byte dbits; /* dtree bits decoder per branch */
4103 inflate_huft *ltree; /* literal/length/eob tree */
4104 inflate_huft *dtree; /* distance tree */
4109 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4111 inflate_huft *tl, *td;
4114 inflate_codes_statef *c;
4116 if ((c = (inflate_codes_statef *)
4117 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4120 c->lbits = (Byte)bl;
4121 c->dbits = (Byte)bd;
4124 Tracev((stderr, "inflate: codes new\n"));
4130 local int inflate_codes(s, z, r)
4131 inflate_blocks_statef *s;
4135 uInt j; /* temporary storage */
4136 inflate_huft *t; /* temporary pointer */
4137 uInt e; /* extra bits or operation */
4138 uLong b; /* bit buffer */
4139 uInt k; /* bits in bit buffer */
4140 Bytef *p; /* input data pointer */
4141 uInt n; /* bytes available there */
4142 Bytef *q; /* output window write pointer */
4143 uInt m; /* bytes to end of window or read pointer */
4144 Bytef *f; /* pointer to copy strings from */
4145 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4147 /* copy input/output information to locals (UPDATE macro restores) */
4150 /* process input and output based on current state */
4151 while (1) switch (c->mode)
4152 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4153 case START: /* x: set up for LEN */
4155 if (m >= 258 && n >= 10)
4158 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4162 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4167 c->sub.code.need = c->lbits;
4168 c->sub.code.tree = c->ltree;
4170 case LEN: /* i: get length/literal/eob next */
4171 j = c->sub.code.need;
4173 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4175 e = (uInt)(t->exop);
4176 if (e == 0) /* literal */
4178 c->sub.lit = t->base;
4179 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4180 "inflate: literal '%c'\n" :
4181 "inflate: literal 0x%02x\n", t->base));
4185 if (e & 16) /* length */
4187 c->sub.copy.get = e & 15;
4192 if ((e & 64) == 0) /* next table */
4194 c->sub.code.need = e;
4195 c->sub.code.tree = t->next;
4198 if (e & 32) /* end of block */
4200 Tracevv((stderr, "inflate: end of block\n"));
4204 c->mode = BADCODE; /* invalid code */
4205 z->msg = "invalid literal/length code";
4208 case LENEXT: /* i: getting length extra (have base) */
4209 j = c->sub.copy.get;
4211 c->len += (uInt)b & inflate_mask[j];
4213 c->sub.code.need = c->dbits;
4214 c->sub.code.tree = c->dtree;
4215 Tracevv((stderr, "inflate: length %u\n", c->len));
4217 case DIST: /* i: get distance next */
4218 j = c->sub.code.need;
4220 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4222 e = (uInt)(t->exop);
4223 if (e & 16) /* distance */
4225 c->sub.copy.get = e & 15;
4226 c->sub.copy.dist = t->base;
4230 if ((e & 64) == 0) /* next table */
4232 c->sub.code.need = e;
4233 c->sub.code.tree = t->next;
4236 c->mode = BADCODE; /* invalid code */
4237 z->msg = "invalid distance code";
4240 case DISTEXT: /* i: getting distance extra */
4241 j = c->sub.copy.get;
4243 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4245 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4247 case COPY: /* o: copying bytes in window, waiting for space */
4248 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4249 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4250 s->end - (c->sub.copy.dist - (q - s->window)) :
4251 q - c->sub.copy.dist;
4253 f = q - c->sub.copy.dist;
4254 if ((uInt)(q - s->window) < c->sub.copy.dist)
4255 f = s->end - (c->sub.copy.dist - (q - s->window));
4267 case LIT: /* o: got literal, waiting for output space */
4272 case WASH: /* o: got eob, possibly more output */
4274 if (s->read != s->write)
4280 case BADCODE: /* x: got error */
4290 local void inflate_codes_free(c, z)
4291 inflate_codes_statef *c;
4294 ZFREE(z, c, sizeof(struct inflate_codes_state));
4295 Tracev((stderr, "inflate: codes free\n"));
4299 /* inflate_util.c -- data and routines common to blocks and codes
4300 * Copyright (C) 1995 Mark Adler
4301 * For conditions of distribution and use, see copyright notice in zlib.h
4304 /* copy as much as possible from the sliding window to the output area */
4305 local int inflate_flush(s, z, r)
4306 inflate_blocks_statef *s;
4313 /* local copies of source and destination pointers */
4317 /* compute number of bytes to copy as far as end of window */
4318 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4319 if (n > z->avail_out) n = z->avail_out;
4320 if (n && r == Z_BUF_ERROR) r = Z_OK;
4322 /* update counters */
4326 /* update check information */
4327 if (s->checkfn != Z_NULL)
4328 s->check = (*s->checkfn)(s->check, q, n);
4330 /* copy as far as end of window */
4337 /* see if more to copy at beginning of window */
4342 if (s->write == s->end)
4343 s->write = s->window;
4345 /* compute bytes to copy */
4346 n = (uInt)(s->write - q);
4347 if (n > z->avail_out) n = z->avail_out;
4348 if (n && r == Z_BUF_ERROR) r = Z_OK;
4350 /* update counters */
4354 /* update check information */
4355 if (s->checkfn != Z_NULL)
4356 s->check = (*s->checkfn)(s->check, q, n);
4366 /* update pointers */
4376 /* inffast.c -- process literals and length/distance pairs fast
4377 * Copyright (C) 1995 Mark Adler
4378 * For conditions of distribution and use, see copyright notice in zlib.h
4381 /* simplify the use of the inflate_huft type with some defines */
4382 #define base more.Base
4383 #define next more.Next
4384 #define exop word.what.Exop
4385 #define bits word.what.Bits
4387 /* macros for bit input with no checking and for returning unused bytes */
4388 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4389 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4391 /* Called with number of bytes left to write in window at least 258
4392 (the maximum string length) and number of input bytes available
4393 at least ten. The ten bytes are six bytes for the longest length/
4394 distance pair plus four bytes for overloading the bit buffer. */
4396 local int inflate_fast(bl, bd, tl, td, s, z)
4398 inflate_huft *tl, *td;
4399 inflate_blocks_statef *s;
4402 inflate_huft *t; /* temporary pointer */
4403 uInt e; /* extra bits or operation */
4404 uLong b; /* bit buffer */
4405 uInt k; /* bits in bit buffer */
4406 Bytef *p; /* input data pointer */
4407 uInt n; /* bytes available there */
4408 Bytef *q; /* output window write pointer */
4409 uInt m; /* bytes to end of window or read pointer */
4410 uInt ml; /* mask for literal/length tree */
4411 uInt md; /* mask for distance tree */
4412 uInt c; /* bytes to copy */
4413 uInt d; /* distance back to copy from */
4414 Bytef *r; /* copy source pointer */
4416 /* load input, output, bit values */
4419 /* initialize masks */
4420 ml = inflate_mask[bl];
4421 md = inflate_mask[bd];
4423 /* do until not enough input or output space for fast loop */
4424 do { /* assume called with m >= 258 && n >= 10 */
4425 /* get literal/length code */
4426 GRABBITS(20) /* max bits for literal/length code */
4427 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4430 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4431 "inflate: * literal '%c'\n" :
4432 "inflate: * literal 0x%02x\n", t->base));
4433 *q++ = (Byte)t->base;
4441 /* get extra bits for length */
4443 c = t->base + ((uInt)b & inflate_mask[e]);
4445 Tracevv((stderr, "inflate: * length %u\n", c));
4447 /* decode distance base of block to copy */
4448 GRABBITS(15); /* max bits for distance code */
4449 e = (t = td + ((uInt)b & md))->exop;
4454 /* get extra bits to add to distance base */
4456 GRABBITS(e) /* get extra bits (up to 13) */
4457 d = t->base + ((uInt)b & inflate_mask[e]);
4459 Tracevv((stderr, "inflate: * distance %u\n", d));
4463 if ((uInt)(q - s->window) >= d) /* offset before dest */
4466 *q++ = *r++; c--; /* minimum count is three, */
4467 *q++ = *r++; c--; /* so unroll loop a little */
4469 else /* else offset after destination */
4471 e = d - (q - s->window); /* bytes from offset to end */
4472 r = s->end - e; /* pointer to offset */
4473 if (c > e) /* if source crosses, */
4475 c -= e; /* copy to end of window */
4479 r = s->window; /* copy rest from start of window */
4482 do { /* copy all or what's left */
4487 else if ((e & 64) == 0)
4488 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4491 z->msg = "invalid distance code";
4494 return Z_DATA_ERROR;
4501 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4504 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4505 "inflate: * literal '%c'\n" :
4506 "inflate: * literal 0x%02x\n", t->base));
4507 *q++ = (Byte)t->base;
4514 Tracevv((stderr, "inflate: * end of block\n"));
4517 return Z_STREAM_END;
4521 z->msg = "invalid literal/length code";
4524 return Z_DATA_ERROR;
4527 } while (m >= 258 && n >= 10);
4529 /* not enough input or output--restore pointers and return */
4537 /* zutil.c -- target dependent utility functions for the compression library
4538 * Copyright (C) 1995 Jean-loup Gailly.
4539 * For conditions of distribution and use, see copyright notice in zlib.h
4542 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
4544 char *zlib_version = ZLIB_VERSION;
4546 char *z_errmsg[] = {
4547 "stream end", /* Z_STREAM_END 1 */
4549 "file error", /* Z_ERRNO (-1) */
4550 "stream error", /* Z_STREAM_ERROR (-2) */
4551 "data error", /* Z_DATA_ERROR (-3) */
4552 "insufficient memory", /* Z_MEM_ERROR (-4) */
4553 "buffer error", /* Z_BUF_ERROR (-5) */
4558 /* adler32.c -- compute the Adler-32 checksum of a data stream
4559 * Copyright (C) 1995 Mark Adler
4560 * For conditions of distribution and use, see copyright notice in zlib.h
4563 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
4565 #define BASE 65521L /* largest prime smaller than 65536 */
4567 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4569 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4570 #define DO2(buf) DO1(buf); DO1(buf);
4571 #define DO4(buf) DO2(buf); DO2(buf);
4572 #define DO8(buf) DO4(buf); DO4(buf);
4573 #define DO16(buf) DO8(buf); DO8(buf);
4575 /* ========================================================================= */
4576 uLong adler32(adler, buf, len)
4581 uLong s1 = adler & 0xffff;
4582 uLong s2 = (adler >> 16) & 0xffff;
4585 if (buf == Z_NULL) return 1L;
4588 k = len < NMAX ? len : NMAX;
4600 return (s2 << 16) | s1;