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 strm->state = (struct internal_state FAR *)s;
606 s->noheader = noheader;
607 s->w_bits = windowBits;
608 s->w_size = 1 << s->w_bits;
609 s->w_mask = s->w_size - 1;
611 s->hash_bits = memLevel + 7;
612 s->hash_size = 1 << s->hash_bits;
613 s->hash_mask = s->hash_size - 1;
614 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
616 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
617 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
618 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
620 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
622 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
624 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
625 s->pending_buf == Z_NULL) {
626 strm->msg = z_errmsg[1-Z_MEM_ERROR];
630 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
631 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
632 /* We overlay pending_buf and d_buf+l_buf. This works since the average
633 * output size for (length,distance) codes is <= 32 bits (worst case
638 s->strategy = strategy;
639 s->method = (Byte)method;
640 s->blocks_in_packet = 0;
642 return deflateReset(strm);
645 /* ========================================================================= */
646 int deflateReset (strm)
651 if (strm == Z_NULL || strm->state == Z_NULL ||
652 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
654 strm->total_in = strm->total_out = 0;
655 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
656 strm->data_type = Z_UNKNOWN;
658 s = (deflate_state *)strm->state;
660 s->pending_out = s->pending_buf;
662 if (s->noheader < 0) {
663 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
665 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
674 /* =========================================================================
675 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
676 * IN assertion: the stream state is correct and there is enough room in
679 local void putShortMSB (s, b)
683 put_byte(s, (Byte)(b >> 8));
684 put_byte(s, (Byte)(b & 0xff));
687 /* =========================================================================
688 * Flush as much pending output as possible.
690 local void flush_pending(strm)
693 deflate_state *state = (deflate_state *) strm->state;
694 unsigned len = state->pending;
696 if (len > strm->avail_out) len = strm->avail_out;
697 if (len == 0) return;
699 if (strm->next_out != NULL) {
700 zmemcpy(strm->next_out, state->pending_out, len);
701 strm->next_out += len;
703 state->pending_out += len;
704 strm->total_out += len;
705 strm->avail_out -= len;
706 state->pending -= len;
707 if (state->pending == 0) {
708 state->pending_out = state->pending_buf;
712 /* ========================================================================= */
713 int deflate (strm, flush)
717 deflate_state *state = (deflate_state *) strm->state;
719 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
721 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
722 ERR_RETURN(strm, Z_STREAM_ERROR);
724 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
726 state->strm = strm; /* just in case */
728 /* Write the zlib header */
729 if (state->status == INIT_STATE) {
731 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
732 uInt level_flags = (state->level-1) >> 1;
734 if (level_flags > 3) level_flags = 3;
735 header |= (level_flags << 6);
736 header += 31 - (header % 31);
738 state->status = BUSY_STATE;
739 putShortMSB(state, header);
742 /* Flush as much pending output as possible */
743 if (state->pending != 0) {
745 if (strm->avail_out == 0) return Z_OK;
748 /* If we came back in here to get the last output from
749 * a previous flush, we're done for now.
751 if (state->status == FLUSH_STATE) {
752 state->status = BUSY_STATE;
753 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
757 /* User must not provide more input after the first FINISH: */
758 if (state->status == FINISH_STATE && strm->avail_in != 0) {
759 ERR_RETURN(strm, Z_BUF_ERROR);
762 /* Start a new block or continue the current one.
764 if (strm->avail_in != 0 || state->lookahead != 0 ||
765 (flush == Z_FINISH && state->status != FINISH_STATE)) {
768 if (flush == Z_FINISH) {
769 state->status = FINISH_STATE;
771 if (state->level <= 3) {
772 quit = deflate_fast(state, flush);
774 quit = deflate_slow(state, flush);
776 if (quit || strm->avail_out == 0)
778 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
779 * of deflate should use the same flush parameter to make sure
780 * that the flush is complete. So we don't have to output an
781 * empty block here, this will be done at next call. This also
782 * ensures that for a very small output buffer, we emit at most
787 /* If a flush was requested, we have a little more to output now. */
788 if (flush != Z_NO_FLUSH && flush != Z_FINISH
789 && state->status != FINISH_STATE) {
791 case Z_PARTIAL_FLUSH:
795 /* Output just the 3-bit `stored' block type value,
796 but not a zero length. */
797 ct_stored_type_only(state);
800 ct_stored_block(state, (char*)0, 0L, 0);
801 /* For a full flush, this empty block will be recognized
802 * as a special marker by inflate_sync().
804 if (flush == Z_FULL_FLUSH) {
805 CLEAR_HASH(state); /* forget history */
809 if (strm->avail_out == 0) {
810 /* We'll have to come back to get the rest of the output;
811 * this ensures we don't output a second zero-length stored
812 * block (or whatever).
814 state->status = FLUSH_STATE;
819 Assert(strm->avail_out > 0, "bug2");
821 if (flush != Z_FINISH) return Z_OK;
822 if (state->noheader) return Z_STREAM_END;
824 /* Write the zlib trailer (adler32) */
825 putShortMSB(state, (uInt)(state->adler >> 16));
826 putShortMSB(state, (uInt)(state->adler & 0xffff));
828 /* If avail_out is zero, the application will call deflate again
831 state->noheader = -1; /* write the trailer only once! */
832 return state->pending != 0 ? Z_OK : Z_STREAM_END;
835 /* ========================================================================= */
836 int deflateEnd (strm)
839 deflate_state *state = (deflate_state *) strm->state;
841 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
843 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
844 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
845 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
846 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
848 ZFREE(strm, state, sizeof(deflate_state));
849 strm->state = Z_NULL;
854 /* ===========================================================================
855 * Read a new buffer from the current input stream, update the adler32
856 * and total number of bytes read.
858 local int zread_buf(strm, buf, size)
863 unsigned len = strm->avail_in;
864 deflate_state *state = (deflate_state *) strm->state;
866 if (len > size) len = size;
867 if (len == 0) return 0;
869 strm->avail_in -= len;
871 if (!state->noheader) {
872 state->adler = adler32(state->adler, strm->next_in, len);
874 zmemcpy(buf, strm->next_in, len);
875 strm->next_in += len;
876 strm->total_in += len;
881 /* ===========================================================================
882 * Initialize the "longest match" routines for a new zlib stream
884 local void lm_init (s)
887 s->window_size = (ulg)2L*s->w_size;
891 /* Set the default configuration parameters:
893 s->max_lazy_match = configuration_table[s->level].max_lazy;
894 s->good_match = configuration_table[s->level].good_length;
895 s->nice_match = configuration_table[s->level].nice_length;
896 s->max_chain_length = configuration_table[s->level].max_chain;
901 s->match_length = MIN_MATCH-1;
902 s->match_available = 0;
905 match_init(); /* initialize the asm code */
909 /* ===========================================================================
910 * Set match_start to the longest match starting at the given string and
911 * return its length. Matches shorter or equal to prev_length are discarded,
912 * in which case the result is equal to prev_length and match_start is
914 * IN assertions: cur_match is the head of the hash chain for the current
915 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
918 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
919 * match.S. The code will be functionally equivalent.
921 local int longest_match(s, cur_match)
923 IPos cur_match; /* current match */
925 unsigned chain_length = s->max_chain_length;/* max hash chain length */
926 register Bytef *scan = s->window + s->strstart; /* current string */
927 register Bytef *match; /* matched string */
928 register int len; /* length of current match */
929 int best_len = s->prev_length; /* best match length so far */
930 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
931 s->strstart - (IPos)MAX_DIST(s) : NIL;
932 /* Stop when cur_match becomes <= limit. To simplify the code,
933 * we prevent matches with the string of window index 0.
935 Posf *prev = s->prev;
936 uInt wmask = s->w_mask;
939 /* Compare two bytes at a time. Note: this is not always beneficial.
940 * Try with and without -DUNALIGNED_OK to check.
942 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
943 register ush scan_start = *(ushf*)scan;
944 register ush scan_end = *(ushf*)(scan+best_len-1);
946 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
947 register Byte scan_end1 = scan[best_len-1];
948 register Byte scan_end = scan[best_len];
951 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
952 * It is easy to get rid of this optimization if necessary.
954 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
956 /* Do not waste too much time if we already have a good match: */
957 if (s->prev_length >= s->good_match) {
960 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
963 Assert(cur_match < s->strstart, "no future");
964 match = s->window + cur_match;
966 /* Skip to next match if the match length cannot increase
967 * or if the match length is less than 2:
969 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
970 /* This code assumes sizeof(unsigned short) == 2. Do not use
971 * UNALIGNED_OK if your compiler uses a different size.
973 if (*(ushf*)(match+best_len-1) != scan_end ||
974 *(ushf*)match != scan_start) continue;
976 /* It is not necessary to compare scan[2] and match[2] since they are
977 * always equal when the other bytes match, given that the hash keys
978 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
979 * strstart+3, +5, ... up to strstart+257. We check for insufficient
980 * lookahead only every 4th comparison; the 128th check will be made
981 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
982 * necessary to put more guard bytes at the end of the window, or
983 * to check more often for insufficient lookahead.
985 Assert(scan[2] == match[2], "scan[2]?");
988 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
989 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
990 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
991 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
993 /* The funny "do {}" generates better code on most compilers */
995 /* Here, scan <= window+strstart+257 */
996 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
997 if (*scan == *match) scan++;
999 len = (MAX_MATCH - 1) - (int)(strend-scan);
1000 scan = strend - (MAX_MATCH-1);
1002 #else /* UNALIGNED_OK */
1004 if (match[best_len] != scan_end ||
1005 match[best_len-1] != scan_end1 ||
1007 *++match != scan[1]) continue;
1009 /* The check at best_len-1 can be removed because it will be made
1010 * again later. (This heuristic is not always a win.)
1011 * It is not necessary to compare scan[2] and match[2] since they
1012 * are always equal when the other bytes match, given that
1013 * the hash keys are equal and that HASH_BITS >= 8.
1016 Assert(*scan == *match, "match[2]?");
1018 /* We check for insufficient lookahead only every 8th comparison;
1019 * the 256th check will be made at strstart+258.
1022 } while (*++scan == *++match && *++scan == *++match &&
1023 *++scan == *++match && *++scan == *++match &&
1024 *++scan == *++match && *++scan == *++match &&
1025 *++scan == *++match && *++scan == *++match &&
1028 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1030 len = MAX_MATCH - (int)(strend - scan);
1031 scan = strend - MAX_MATCH;
1033 #endif /* UNALIGNED_OK */
1035 if (len > best_len) {
1036 s->match_start = cur_match;
1038 if (len >= s->nice_match) break;
1040 scan_end = *(ushf*)(scan+best_len-1);
1042 scan_end1 = scan[best_len-1];
1043 scan_end = scan[best_len];
1046 } while ((cur_match = prev[cur_match & wmask]) > limit
1047 && --chain_length != 0);
1054 /* ===========================================================================
1055 * Check that the match at match_start is indeed a match.
1057 local void check_match(s, start, match, length)
1062 /* check that the match is indeed a match */
1063 if (memcmp((charf *)s->window + match,
1064 (charf *)s->window + start, length) != EQUAL) {
1066 " start %u, match %u, length %d\n",
1067 start, match, length);
1068 do { fprintf(stderr, "%c%c", s->window[match++],
1069 s->window[start++]); } while (--length != 0);
1070 z_error("invalid match");
1073 fprintf(stderr,"\\[%d,%d]", start-match, length);
1074 do { putc(s->window[start++], stderr); } while (--length != 0);
1078 # define check_match(s, start, match, length)
1081 /* ===========================================================================
1082 * Fill the window when the lookahead becomes insufficient.
1083 * Updates strstart and lookahead.
1085 * IN assertion: lookahead < MIN_LOOKAHEAD
1086 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1087 * At least one byte has been read, or avail_in == 0; reads are
1088 * performed for at least two bytes (required for the zip translate_eol
1089 * option -- not supported here).
1091 local void fill_window(s)
1094 register unsigned n, m;
1096 unsigned more; /* Amount of free space at the end of the window. */
1097 uInt wsize = s->w_size;
1100 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1102 /* Deal with !@#$% 64K limit: */
1103 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1105 } else if (more == (unsigned)(-1)) {
1106 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1107 * and lookahead == 1 (input done one byte at time)
1111 /* If the window is almost full and there is insufficient lookahead,
1112 * move the upper half to the lower one to make room in the upper half.
1114 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1116 /* By the IN assertion, the window is not empty so we can't confuse
1117 * more == 0 with more == 64K on a 16 bit machine.
1119 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1121 s->match_start -= wsize;
1122 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1124 s->block_start -= (long) wsize;
1126 /* Slide the hash table (could be avoided with 32 bit values
1127 at the expense of memory usage):
1133 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1140 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1141 /* If n is not on any hash chain, prev[n] is garbage but
1142 * its value will never be used.
1148 if (s->strm->avail_in == 0) return;
1150 /* If there was no sliding:
1151 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1152 * more == window_size - lookahead - strstart
1153 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1154 * => more >= window_size - 2*WSIZE + 2
1155 * In the BIG_MEM or MMAP case (not yet supported),
1156 * window_size == input_size + MIN_LOOKAHEAD &&
1157 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1158 * Otherwise, window_size == 2*WSIZE so more >= 2.
1159 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1161 Assert(more >= 2, "more < 2");
1163 n = zread_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1167 /* Initialize the hash value now that we have some input: */
1168 if (s->lookahead >= MIN_MATCH) {
1169 s->ins_h = s->window[s->strstart];
1170 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1172 Call UPDATE_HASH() MIN_MATCH-3 more times
1175 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1176 * but this is not important since only literal bytes will be emitted.
1179 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1182 /* ===========================================================================
1183 * Flush the current block, with given end-of-file flag.
1184 * IN assertion: strstart is set to the end of the current match.
1186 #define FLUSH_BLOCK_ONLY(s, flush) { \
1187 ct_flush_block(s, (s->block_start >= 0L ? \
1188 (charf *)&s->window[(unsigned)s->block_start] : \
1189 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1190 s->block_start = s->strstart; \
1191 flush_pending(s->strm); \
1192 Tracev((stderr,"[FLUSH]")); \
1195 /* Same but force premature exit if necessary. */
1196 #define FLUSH_BLOCK(s, flush) { \
1197 FLUSH_BLOCK_ONLY(s, flush); \
1198 if (s->strm->avail_out == 0) return 1; \
1201 /* ===========================================================================
1202 * Compress as much as possible from the input stream, return true if
1203 * processing was terminated prematurely (no more input or output space).
1204 * This function does not perform lazy evaluationof matches and inserts
1205 * new strings in the dictionary only for unmatched strings or for short
1206 * matches. It is used only for the fast compression options.
1208 local int deflate_fast(s, flush)
1212 IPos hash_head = NIL; /* head of the hash chain */
1213 int bflush; /* set if current block must be flushed */
1215 s->prev_length = MIN_MATCH-1;
1218 /* Make sure that we always have enough lookahead, except
1219 * at the end of the input file. We need MAX_MATCH bytes
1220 * for the next match, plus MIN_MATCH bytes to insert the
1221 * string following the next match.
1223 if (s->lookahead < MIN_LOOKAHEAD) {
1225 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1227 if (s->lookahead == 0) break; /* flush the current block */
1230 /* Insert the string window[strstart .. strstart+2] in the
1231 * dictionary, and set hash_head to the head of the hash chain:
1233 if (s->lookahead >= MIN_MATCH) {
1234 INSERT_STRING(s, s->strstart, hash_head);
1237 /* Find the longest match, discarding those <= prev_length.
1238 * At this point we have always match_length < MIN_MATCH
1240 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1241 /* To simplify the code, we prevent matches with the string
1242 * of window index 0 (in particular we have to avoid a match
1243 * of the string with itself at the start of the input file).
1245 if (s->strategy != Z_HUFFMAN_ONLY) {
1246 s->match_length = longest_match (s, hash_head);
1248 /* longest_match() sets match_start */
1250 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1252 if (s->match_length >= MIN_MATCH) {
1253 check_match(s, s->strstart, s->match_start, s->match_length);
1255 bflush = ct_tally(s, s->strstart - s->match_start,
1256 s->match_length - MIN_MATCH);
1258 s->lookahead -= s->match_length;
1260 /* Insert new strings in the hash table only if the match length
1261 * is not too large. This saves time but degrades compression.
1263 if (s->match_length <= s->max_insert_length &&
1264 s->lookahead >= MIN_MATCH) {
1265 s->match_length--; /* string at strstart already in hash table */
1268 INSERT_STRING(s, s->strstart, hash_head);
1269 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1270 * always MIN_MATCH bytes ahead.
1272 } while (--s->match_length != 0);
1275 s->strstart += s->match_length;
1276 s->match_length = 0;
1277 s->ins_h = s->window[s->strstart];
1278 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1280 Call UPDATE_HASH() MIN_MATCH-3 more times
1282 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1283 * matter since it will be recomputed at next deflate call.
1287 /* No match, output a literal byte */
1288 Tracevv((stderr,"%c", s->window[s->strstart]));
1289 bflush = ct_tally (s, 0, s->window[s->strstart]);
1293 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1295 FLUSH_BLOCK(s, flush);
1296 return 0; /* normal exit */
1299 /* ===========================================================================
1300 * Same as above, but achieves better compression. We use a lazy
1301 * evaluation for matches: a match is finally adopted only if there is
1302 * no better match at the next window position.
1304 local int deflate_slow(s, flush)
1308 IPos hash_head = NIL; /* head of hash chain */
1309 int bflush; /* set if current block must be flushed */
1311 /* Process the input block. */
1313 /* Make sure that we always have enough lookahead, except
1314 * at the end of the input file. We need MAX_MATCH bytes
1315 * for the next match, plus MIN_MATCH bytes to insert the
1316 * string following the next match.
1318 if (s->lookahead < MIN_LOOKAHEAD) {
1320 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1322 if (s->lookahead == 0) break; /* flush the current block */
1325 /* Insert the string window[strstart .. strstart+2] in the
1326 * dictionary, and set hash_head to the head of the hash chain:
1328 if (s->lookahead >= MIN_MATCH) {
1329 INSERT_STRING(s, s->strstart, hash_head);
1332 if (flush == Z_INSERT_ONLY) {
1338 /* Find the longest match, discarding those <= prev_length.
1340 s->prev_length = s->match_length, s->prev_match = s->match_start;
1341 s->match_length = MIN_MATCH-1;
1343 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1344 s->strstart - hash_head <= MAX_DIST(s)) {
1345 /* To simplify the code, we prevent matches with the string
1346 * of window index 0 (in particular we have to avoid a match
1347 * of the string with itself at the start of the input file).
1349 if (s->strategy != Z_HUFFMAN_ONLY) {
1350 s->match_length = longest_match (s, hash_head);
1352 /* longest_match() sets match_start */
1353 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1355 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1356 (s->match_length == MIN_MATCH &&
1357 s->strstart - s->match_start > TOO_FAR))) {
1359 /* If prev_match is also MIN_MATCH, match_start is garbage
1360 * but we will ignore the current match anyway.
1362 s->match_length = MIN_MATCH-1;
1365 /* If there was a match at the previous step and the current
1366 * match is not better, output the previous match:
1368 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1369 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1370 /* Do not insert strings in hash table beyond this. */
1372 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1374 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1375 s->prev_length - MIN_MATCH);
1377 /* Insert in hash table all strings up to the end of the match.
1378 * strstart-1 and strstart are already inserted. If there is not
1379 * enough lookahead, the last two strings are not inserted in
1382 s->lookahead -= s->prev_length-1;
1383 s->prev_length -= 2;
1385 if (++s->strstart <= max_insert) {
1386 INSERT_STRING(s, s->strstart, hash_head);
1388 } while (--s->prev_length != 0);
1389 s->match_available = 0;
1390 s->match_length = MIN_MATCH-1;
1393 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1395 } else if (s->match_available) {
1396 /* If there was no match at the previous position, output a
1397 * single literal. If there was a match but the current match
1398 * is longer, truncate the previous match to a single literal.
1400 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1401 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1402 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1406 if (s->strm->avail_out == 0) return 1;
1408 /* There is no previous match to compare with, wait for
1409 * the next step to decide.
1411 s->match_available = 1;
1416 if (flush == Z_INSERT_ONLY) {
1417 s->block_start = s->strstart;
1420 Assert (flush != Z_NO_FLUSH, "no flush?");
1421 if (s->match_available) {
1422 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1423 ct_tally (s, 0, s->window[s->strstart-1]);
1424 s->match_available = 0;
1426 FLUSH_BLOCK(s, flush);
1432 /* trees.c -- output deflated data using Huffman coding
1433 * Copyright (C) 1995 Jean-loup Gailly
1434 * For conditions of distribution and use, see copyright notice in zlib.h
1440 * The "deflation" process uses several Huffman trees. The more
1441 * common source values are represented by shorter bit sequences.
1443 * Each code tree is stored in a compressed form which is itself
1444 * a Huffman encoding of the lengths of all the code strings (in
1445 * ascending order by source values). The actual code strings are
1446 * reconstructed from the lengths in the inflate process, as described
1447 * in the deflate specification.
1451 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1452 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1455 * Data Compression: Methods and Theory, pp. 49-50.
1456 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1460 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1463 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
1469 /* ===========================================================================
1473 #define MAX_BL_BITS 7
1474 /* Bit length codes must not exceed MAX_BL_BITS bits */
1476 #define END_BLOCK 256
1477 /* end of block literal code */
1480 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1482 #define REPZ_3_10 17
1483 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1485 #define REPZ_11_138 18
1486 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1488 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1489 = {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};
1491 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1492 = {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};
1494 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1495 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1497 local uch bl_order[BL_CODES]
1498 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1499 /* The lengths of the bit length codes are sent in order of decreasing
1500 * probability, to avoid transmitting the lengths for unused bit length codes.
1503 #define Buf_size (8 * 2*sizeof(char))
1504 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1505 * more than 16 bits on some systems.)
1508 /* ===========================================================================
1509 * Local data. These are initialized only once.
1510 * To do: initialize at compile time to be completely reentrant. ???
1513 local ct_data static_ltree[L_CODES+2];
1514 /* The static literal tree. Since the bit lengths are imposed, there is no
1515 * need for the L_CODES extra codes used during heap construction. However
1516 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1520 local ct_data static_dtree[D_CODES];
1521 /* The static distance tree. (Actually a trivial tree since all codes use
1525 local uch dist_code[512];
1526 /* distance codes. The first 256 values correspond to the distances
1527 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1528 * the 15 bit distances.
1531 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1532 /* length code for each normalized match length (0 == MIN_MATCH) */
1534 local int base_length[LENGTH_CODES];
1535 /* First normalized length for each code (0 = MIN_MATCH) */
1537 local int base_dist[D_CODES];
1538 /* First normalized distance for each code (0 = distance of 1) */
1540 struct static_tree_desc_s {
1541 ct_data *static_tree; /* static tree or NULL */
1542 intf *extra_bits; /* extra bits for each code or NULL */
1543 int extra_base; /* base index for extra_bits */
1544 int elems; /* max number of elements in the tree */
1545 int max_length; /* max bit length for the codes */
1548 local static_tree_desc static_l_desc =
1549 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1551 local static_tree_desc static_d_desc =
1552 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1554 local static_tree_desc static_bl_desc =
1555 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1557 /* ===========================================================================
1558 * Local (static) routines in this file.
1561 local void ct_static_init OF((void));
1562 local void init_block OF((deflate_state *s));
1563 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1564 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1565 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1566 local void build_tree OF((deflate_state *s, tree_desc *desc));
1567 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1568 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1569 local int build_bl_tree OF((deflate_state *s));
1570 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1572 local void compress_block OF((deflate_state *s, ct_data *ltree,
1574 local void set_data_type OF((deflate_state *s));
1575 local unsigned bi_reverse OF((unsigned value, int length));
1576 local void bi_windup OF((deflate_state *s));
1577 local void bi_flush OF((deflate_state *s));
1578 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1582 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1583 /* Send a code of the given tree. c and tree must not have side effects */
1585 #else /* DEBUG_ZLIB */
1586 # define send_code(s, c, tree) \
1587 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1588 send_bits(s, tree[c].Code, tree[c].Len); }
1591 #define d_code(dist) \
1592 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1593 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1594 * must not have side effects. dist_code[256] and dist_code[257] are never
1598 /* ===========================================================================
1599 * Output a short LSB first on the stream.
1600 * IN assertion: there is enough room in pendingBuf.
1602 #define put_short(s, w) { \
1603 put_byte(s, (uch)((w) & 0xff)); \
1604 put_byte(s, (uch)((ush)(w) >> 8)); \
1607 /* ===========================================================================
1608 * Send a value on a given number of bits.
1609 * IN assertion: length <= 16 and value fits in length bits.
1612 local void send_bits OF((deflate_state *s, int value, int length));
1614 local void send_bits(s, value, length)
1616 int value; /* value to send */
1617 int length; /* number of bits */
1619 Tracev((stderr," l %2d v %4x ", length, value));
1620 Assert(length > 0 && length <= 15, "invalid length");
1621 s->bits_sent += (ulg)length;
1623 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1624 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1625 * unused bits in value.
1627 if (s->bi_valid > (int)Buf_size - length) {
1628 s->bi_buf |= (value << s->bi_valid);
1629 put_short(s, s->bi_buf);
1630 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1631 s->bi_valid += length - Buf_size;
1633 s->bi_buf |= value << s->bi_valid;
1634 s->bi_valid += length;
1637 #else /* !DEBUG_ZLIB */
1639 #define send_bits(s, value, length) \
1640 { int len = length;\
1641 if (s->bi_valid > (int)Buf_size - len) {\
1643 s->bi_buf |= (val << s->bi_valid);\
1644 put_short(s, s->bi_buf);\
1645 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1646 s->bi_valid += len - Buf_size;\
1648 s->bi_buf |= (value) << s->bi_valid;\
1649 s->bi_valid += len;\
1652 #endif /* DEBUG_ZLIB */
1655 /* the arguments must not have side effects */
1657 /* ===========================================================================
1658 * Initialize the various 'constant' tables.
1659 * To do: do this at compile time.
1661 local void ct_static_init()
1663 int n; /* iterates over tree elements */
1664 int bits; /* bit counter */
1665 int length; /* length value */
1666 int code; /* code value */
1667 int dist; /* distance index */
1668 ush bl_count[MAX_BITS+1];
1669 /* number of codes at each bit length for an optimal tree */
1671 /* Initialize the mapping length (0..255) -> length code (0..28) */
1673 for (code = 0; code < LENGTH_CODES-1; code++) {
1674 base_length[code] = length;
1675 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1676 length_code[length++] = (uch)code;
1679 Assert (length == 256, "ct_static_init: length != 256");
1680 /* Note that the length 255 (match length 258) can be represented
1681 * in two different ways: code 284 + 5 bits or code 285, so we
1682 * overwrite length_code[255] to use the best encoding:
1684 length_code[length-1] = (uch)code;
1686 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1688 for (code = 0 ; code < 16; code++) {
1689 base_dist[code] = dist;
1690 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1691 dist_code[dist++] = (uch)code;
1694 Assert (dist == 256, "ct_static_init: dist != 256");
1695 dist >>= 7; /* from now on, all distances are divided by 128 */
1696 for ( ; code < D_CODES; code++) {
1697 base_dist[code] = dist << 7;
1698 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1699 dist_code[256 + dist++] = (uch)code;
1702 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1704 /* Construct the codes of the static literal tree */
1705 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1707 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1708 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1709 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1710 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1711 /* Codes 286 and 287 do not exist, but we must include them in the
1712 * tree construction to get a canonical Huffman tree (longest code
1715 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1717 /* The static distance tree is trivial: */
1718 for (n = 0; n < D_CODES; n++) {
1719 static_dtree[n].Len = 5;
1720 static_dtree[n].Code = bi_reverse(n, 5);
1724 /* ===========================================================================
1725 * Initialize the tree data structures for a new zlib stream.
1727 local void ct_init(s)
1730 if (static_dtree[0].Len == 0) {
1731 ct_static_init(); /* To do: at compile time */
1734 s->compressed_len = 0L;
1736 s->l_desc.dyn_tree = s->dyn_ltree;
1737 s->l_desc.stat_desc = &static_l_desc;
1739 s->d_desc.dyn_tree = s->dyn_dtree;
1740 s->d_desc.stat_desc = &static_d_desc;
1742 s->bl_desc.dyn_tree = s->bl_tree;
1743 s->bl_desc.stat_desc = &static_bl_desc;
1747 s->last_eob_len = 8; /* enough lookahead for inflate */
1751 s->blocks_in_packet = 0;
1753 /* Initialize the first block of the first file: */
1757 /* ===========================================================================
1758 * Initialize a new block.
1760 local void init_block(s)
1763 int n; /* iterates over tree elements */
1765 /* Initialize the trees. */
1766 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1767 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1768 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1770 s->dyn_ltree[END_BLOCK].Freq = 1;
1771 s->opt_len = s->static_len = 0L;
1772 s->last_lit = s->matches = 0;
1776 /* Index within the heap array of least frequent node in the Huffman tree */
1779 /* ===========================================================================
1780 * Remove the smallest element from the heap and recreate the heap with
1781 * one less element. Updates heap and heap_len.
1783 #define pqremove(s, tree, top) \
1785 top = s->heap[SMALLEST]; \
1786 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1787 pqdownheap(s, tree, SMALLEST); \
1790 /* ===========================================================================
1791 * Compares to subtrees, using the tree depth as tie breaker when
1792 * the subtrees have equal frequency. This minimizes the worst case length.
1794 #define smaller(tree, n, m, depth) \
1795 (tree[n].Freq < tree[m].Freq || \
1796 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1798 /* ===========================================================================
1799 * Restore the heap property by moving down the tree starting at node k,
1800 * exchanging a node with the smallest of its two sons if necessary, stopping
1801 * when the heap property is re-established (each father smaller than its
1804 local void pqdownheap(s, tree, k)
1806 ct_data *tree; /* the tree to restore */
1807 int k; /* node to move down */
1810 int j = k << 1; /* left son of k */
1811 while (j <= s->heap_len) {
1812 /* Set j to the smallest of the two sons: */
1813 if (j < s->heap_len &&
1814 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1817 /* Exit if v is smaller than both sons */
1818 if (smaller(tree, v, s->heap[j], s->depth)) break;
1820 /* Exchange v with the smallest son */
1821 s->heap[k] = s->heap[j]; k = j;
1823 /* And continue down the tree, setting j to the left son of k */
1829 /* ===========================================================================
1830 * Compute the optimal bit lengths for a tree and update the total bit length
1831 * for the current block.
1832 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1833 * above are the tree nodes sorted by increasing frequency.
1834 * OUT assertions: the field len is set to the optimal bit length, the
1835 * array bl_count contains the frequencies for each bit length.
1836 * The length opt_len is updated; static_len is also updated if stree is
1839 local void gen_bitlen(s, desc)
1841 tree_desc *desc; /* the tree descriptor */
1843 ct_data *tree = desc->dyn_tree;
1844 int max_code = desc->max_code;
1845 ct_data *stree = desc->stat_desc->static_tree;
1846 intf *extra = desc->stat_desc->extra_bits;
1847 int base = desc->stat_desc->extra_base;
1848 int max_length = desc->stat_desc->max_length;
1849 int h; /* heap index */
1850 int n, m; /* iterate over the tree elements */
1851 int bits; /* bit length */
1852 int xbits; /* extra bits */
1853 ush f; /* frequency */
1854 int overflow = 0; /* number of elements with bit length too large */
1856 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1858 /* In a first pass, compute the optimal bit lengths (which may
1859 * overflow in the case of the bit length tree).
1861 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1863 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1865 bits = tree[tree[n].Dad].Len + 1;
1866 if (bits > max_length) bits = max_length, overflow++;
1867 tree[n].Len = (ush)bits;
1868 /* We overwrite tree[n].Dad which is no longer needed */
1870 if (n > max_code) continue; /* not a leaf node */
1872 s->bl_count[bits]++;
1874 if (n >= base) xbits = extra[n-base];
1876 s->opt_len += (ulg)f * (bits + xbits);
1877 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1879 if (overflow == 0) return;
1881 Trace((stderr,"\nbit length overflow\n"));
1882 /* This happens for example on obj2 and pic of the Calgary corpus */
1884 /* Find the first bit length which could increase: */
1886 bits = max_length-1;
1887 while (s->bl_count[bits] == 0) bits--;
1888 s->bl_count[bits]--; /* move one leaf down the tree */
1889 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1890 s->bl_count[max_length]--;
1891 /* The brother of the overflow item also moves one step up,
1892 * but this does not affect bl_count[max_length]
1895 } while (overflow > 0);
1897 /* Now recompute all bit lengths, scanning in increasing frequency.
1898 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1899 * lengths instead of fixing only the wrong ones. This idea is taken
1900 * from 'ar' written by Haruhiko Okumura.)
1902 for (bits = max_length; bits != 0; bits--) {
1903 n = s->bl_count[bits];
1906 if (m > max_code) continue;
1907 if (tree[m].Len != (unsigned) bits) {
1908 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1909 s->opt_len += ((long)bits - (long)tree[m].Len)
1910 *(long)tree[m].Freq;
1911 tree[m].Len = (ush)bits;
1918 /* ===========================================================================
1919 * Generate the codes for a given tree and bit counts (which need not be
1921 * IN assertion: the array bl_count contains the bit length statistics for
1922 * the given tree and the field len is set for all tree elements.
1923 * OUT assertion: the field code is set for all tree elements of non
1926 local void gen_codes (tree, max_code, bl_count)
1927 ct_data *tree; /* the tree to decorate */
1928 int max_code; /* largest code with non zero frequency */
1929 ushf *bl_count; /* number of codes at each bit length */
1931 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1932 ush code = 0; /* running code value */
1933 int bits; /* bit index */
1934 int n; /* code index */
1936 /* The distribution counts are first used to generate the code values
1937 * without bit reversal.
1939 for (bits = 1; bits <= MAX_BITS; bits++) {
1940 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1942 /* Check that the bit counts in bl_count are consistent. The last code
1945 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1946 "inconsistent bit counts");
1947 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1949 for (n = 0; n <= max_code; n++) {
1950 int len = tree[n].Len;
1951 if (len == 0) continue;
1952 /* Now reverse the bits */
1953 tree[n].Code = bi_reverse(next_code[len]++, len);
1955 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1956 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1960 /* ===========================================================================
1961 * Construct one Huffman tree and assigns the code bit strings and lengths.
1962 * Update the total bit length for the current block.
1963 * IN assertion: the field freq is set for all tree elements.
1964 * OUT assertions: the fields len and code are set to the optimal bit length
1965 * and corresponding code. The length opt_len is updated; static_len is
1966 * also updated if stree is not null. The field max_code is set.
1968 local void build_tree(s, desc)
1970 tree_desc *desc; /* the tree descriptor */
1972 ct_data *tree = desc->dyn_tree;
1973 ct_data *stree = desc->stat_desc->static_tree;
1974 int elems = desc->stat_desc->elems;
1975 int n, m; /* iterate over heap elements */
1976 int max_code = -1; /* largest code with non zero frequency */
1977 int node; /* new node being created */
1979 /* Construct the initial heap, with least frequent element in
1980 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
1981 * heap[0] is not used.
1983 s->heap_len = 0, s->heap_max = HEAP_SIZE;
1985 for (n = 0; n < elems; n++) {
1986 if (tree[n].Freq != 0) {
1987 s->heap[++(s->heap_len)] = max_code = n;
1994 /* The pkzip format requires that at least one distance code exists,
1995 * and that at least one bit should be sent even if there is only one
1996 * possible code. So to avoid special checks later on we force at least
1997 * two codes of non zero frequency.
1999 while (s->heap_len < 2) {
2000 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2001 tree[node].Freq = 1;
2003 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2004 /* node is 0 or 1 so it does not have extra bits */
2006 desc->max_code = max_code;
2008 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2009 * establish sub-heaps of increasing lengths:
2011 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2013 /* Construct the Huffman tree by repeatedly combining the least two
2016 node = elems; /* next internal node of the tree */
2018 pqremove(s, tree, n); /* n = node of least frequency */
2019 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2021 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2022 s->heap[--(s->heap_max)] = m;
2024 /* Create a new node father of n and m */
2025 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2026 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2027 tree[n].Dad = tree[m].Dad = (ush)node;
2029 if (tree == s->bl_tree) {
2030 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2031 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2034 /* and insert the new node in the heap */
2035 s->heap[SMALLEST] = node++;
2036 pqdownheap(s, tree, SMALLEST);
2038 } while (s->heap_len >= 2);
2040 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2042 /* At this point, the fields freq and dad are set. We can now
2043 * generate the bit lengths.
2045 gen_bitlen(s, (tree_desc *)desc);
2047 /* The field len is now set, we can generate the bit codes */
2048 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2051 /* ===========================================================================
2052 * Scan a literal or distance tree to determine the frequencies of the codes
2053 * in the bit length tree.
2055 local void scan_tree (s, tree, max_code)
2057 ct_data *tree; /* the tree to be scanned */
2058 int max_code; /* and its largest code of non zero frequency */
2060 int n; /* iterates over all tree elements */
2061 int prevlen = -1; /* last emitted length */
2062 int curlen; /* length of current code */
2063 int nextlen = tree[0].Len; /* length of next code */
2064 int count = 0; /* repeat count of the current code */
2065 int max_count = 7; /* max repeat count */
2066 int min_count = 4; /* min repeat count */
2068 if (nextlen == 0) max_count = 138, min_count = 3;
2069 tree[max_code+1].Len = (ush)0xffff; /* guard */
2071 for (n = 0; n <= max_code; n++) {
2072 curlen = nextlen; nextlen = tree[n+1].Len;
2073 if (++count < max_count && curlen == nextlen) {
2075 } else if (count < min_count) {
2076 s->bl_tree[curlen].Freq += count;
2077 } else if (curlen != 0) {
2078 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2079 s->bl_tree[REP_3_6].Freq++;
2080 } else if (count <= 10) {
2081 s->bl_tree[REPZ_3_10].Freq++;
2083 s->bl_tree[REPZ_11_138].Freq++;
2085 count = 0; prevlen = curlen;
2087 max_count = 138, min_count = 3;
2088 } else if (curlen == nextlen) {
2089 max_count = 6, min_count = 3;
2091 max_count = 7, min_count = 4;
2096 /* ===========================================================================
2097 * Send a literal or distance tree in compressed form, using the codes in
2100 local void send_tree (s, tree, max_code)
2102 ct_data *tree; /* the tree to be scanned */
2103 int max_code; /* and its largest code of non zero frequency */
2105 int n; /* iterates over all tree elements */
2106 int prevlen = -1; /* last emitted length */
2107 int curlen; /* length of current code */
2108 int nextlen = tree[0].Len; /* length of next code */
2109 int count = 0; /* repeat count of the current code */
2110 int max_count = 7; /* max repeat count */
2111 int min_count = 4; /* min repeat count */
2113 /* tree[max_code+1].Len = -1; */ /* guard already set */
2114 if (nextlen == 0) max_count = 138, min_count = 3;
2116 for (n = 0; n <= max_code; n++) {
2117 curlen = nextlen; nextlen = tree[n+1].Len;
2118 if (++count < max_count && curlen == nextlen) {
2120 } else if (count < min_count) {
2121 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2123 } else if (curlen != 0) {
2124 if (curlen != prevlen) {
2125 send_code(s, curlen, s->bl_tree); count--;
2127 Assert(count >= 3 && count <= 6, " 3_6?");
2128 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2130 } else if (count <= 10) {
2131 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2134 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2136 count = 0; prevlen = curlen;
2138 max_count = 138, min_count = 3;
2139 } else if (curlen == nextlen) {
2140 max_count = 6, min_count = 3;
2142 max_count = 7, min_count = 4;
2147 /* ===========================================================================
2148 * Construct the Huffman tree for the bit lengths and return the index in
2149 * bl_order of the last bit length code to send.
2151 local int build_bl_tree(s)
2154 int max_blindex; /* index of last bit length code of non zero freq */
2156 /* Determine the bit length frequencies for literal and distance trees */
2157 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2158 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2160 /* Build the bit length tree: */
2161 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2162 /* opt_len now includes the length of the tree representations, except
2163 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2166 /* Determine the number of bit length codes to send. The pkzip format
2167 * requires that at least 4 bit length codes be sent. (appnote.txt says
2168 * 3 but the actual value used is 4.)
2170 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2171 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2173 /* Update opt_len to include the bit length tree and counts */
2174 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2175 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2176 s->opt_len, s->static_len));
2181 /* ===========================================================================
2182 * Send the header for a block using dynamic Huffman trees: the counts, the
2183 * lengths of the bit length codes, the literal tree and the distance tree.
2184 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2186 local void send_all_trees(s, lcodes, dcodes, blcodes)
2188 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2190 int rank; /* index in bl_order */
2192 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2193 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2195 Tracev((stderr, "\nbl counts: "));
2196 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2197 send_bits(s, dcodes-1, 5);
2198 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2199 for (rank = 0; rank < blcodes; rank++) {
2200 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2201 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2203 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2205 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2206 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2208 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2209 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2212 /* ===========================================================================
2213 * Send a stored block
2215 local void ct_stored_block(s, buf, stored_len, eof)
2217 charf *buf; /* input block */
2218 ulg stored_len; /* length of input block */
2219 int eof; /* true if this is the last block for a file */
2221 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2222 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2223 s->compressed_len += (stored_len + 4) << 3;
2225 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2228 /* Send just the `stored block' type code without any length bytes or data.
2230 local void ct_stored_type_only(s)
2233 send_bits(s, (STORED_BLOCK << 1), 3);
2235 s->compressed_len = (s->compressed_len + 3) & ~7L;
2239 /* ===========================================================================
2240 * Send one empty static block to give enough lookahead for inflate.
2241 * This takes 10 bits, of which 7 may remain in the bit buffer.
2242 * The current inflate code requires 9 bits of lookahead. If the EOB
2243 * code for the previous block was coded on 5 bits or less, inflate
2244 * may have only 5+3 bits of lookahead to decode this EOB.
2245 * (There are no problems if the previous block is stored or fixed.)
2247 local void ct_align(s)
2250 send_bits(s, STATIC_TREES<<1, 3);
2251 send_code(s, END_BLOCK, static_ltree);
2252 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2254 /* Of the 10 bits for the empty block, we have already sent
2255 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2256 * block was thus its length plus what we have just sent.
2258 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2259 send_bits(s, STATIC_TREES<<1, 3);
2260 send_code(s, END_BLOCK, static_ltree);
2261 s->compressed_len += 10L;
2264 s->last_eob_len = 7;
2267 /* ===========================================================================
2268 * Determine the best encoding for the current block: dynamic trees, static
2269 * trees or store, and output the encoded block to the zip file. This function
2270 * returns the total compressed length for the file so far.
2272 local ulg ct_flush_block(s, buf, stored_len, flush)
2274 charf *buf; /* input block, or NULL if too old */
2275 ulg stored_len; /* length of input block */
2276 int flush; /* Z_FINISH if this is the last block for a file */
2278 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2279 int max_blindex; /* index of last bit length code of non zero freq */
2280 int eof = flush == Z_FINISH;
2282 ++s->blocks_in_packet;
2284 /* Check if the file is ascii or binary */
2285 if (s->data_type == UNKNOWN) set_data_type(s);
2287 /* Construct the literal and distance trees */
2288 build_tree(s, (tree_desc *)(&(s->l_desc)));
2289 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2292 build_tree(s, (tree_desc *)(&(s->d_desc)));
2293 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2295 /* At this point, opt_len and static_len are the total bit lengths of
2296 * the compressed block data, excluding the tree representations.
2299 /* Build the bit length tree for the above two trees, and get the index
2300 * in bl_order of the last bit length code to send.
2302 max_blindex = build_bl_tree(s);
2304 /* Determine the best encoding. Compute first the block length in bytes */
2305 opt_lenb = (s->opt_len+3+7)>>3;
2306 static_lenb = (s->static_len+3+7)>>3;
2308 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2309 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2312 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2314 /* If compression failed and this is the first and last block,
2315 * and if the .zip file can be seeked (to rewrite the local header),
2316 * the whole file is transformed into a stored file:
2318 #ifdef STORED_FILE_OK
2319 # ifdef FORCE_STORED_FILE
2320 if (eof && compressed_len == 0L) /* force stored file */
2322 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2325 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2326 if (buf == (charf*)0) error ("block vanished");
2328 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2329 s->compressed_len = stored_len << 3;
2332 #endif /* STORED_FILE_OK */
2335 if (buf != (char*)0) /* force stored block */
2337 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2338 /* 4: two words for the lengths */
2341 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2342 * Otherwise we can't have processed more than WSIZE input bytes since
2343 * the last block flush, because compression would have been
2344 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2345 * transform a block into a stored block.
2347 ct_stored_block(s, buf, stored_len, eof);
2351 if (static_lenb >= 0) /* force static trees */
2353 if (static_lenb == opt_lenb)
2356 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2357 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2358 s->compressed_len += 3 + s->static_len;
2360 send_bits(s, (DYN_TREES<<1)+eof, 3);
2361 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2363 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2364 s->compressed_len += 3 + s->opt_len;
2366 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2371 s->compressed_len += 7; /* align on byte boundary */
2373 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2374 s->compressed_len-7*eof));
2376 return s->compressed_len >> 3;
2379 /* ===========================================================================
2380 * Save the match info and tally the frequency counts. Return true if
2381 * the current block must be flushed.
2383 local int ct_tally (s, dist, lc)
2385 int dist; /* distance of matched string */
2386 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2388 s->d_buf[s->last_lit] = (ush)dist;
2389 s->l_buf[s->last_lit++] = (uch)lc;
2391 /* lc is the unmatched char */
2392 s->dyn_ltree[lc].Freq++;
2395 /* Here, lc is the match length - MIN_MATCH */
2396 dist--; /* dist = match distance - 1 */
2397 Assert((ush)dist < (ush)MAX_DIST(s) &&
2398 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2399 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2401 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2402 s->dyn_dtree[d_code(dist)].Freq++;
2405 /* Try to guess if it is profitable to stop the current block here */
2406 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2407 /* Compute an upper bound for the compressed length */
2408 ulg out_length = (ulg)s->last_lit*8L;
2409 ulg in_length = (ulg)s->strstart - s->block_start;
2411 for (dcode = 0; dcode < D_CODES; dcode++) {
2412 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2413 (5L+extra_dbits[dcode]);
2416 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2417 s->last_lit, in_length, out_length,
2418 100L - out_length*100L/in_length));
2419 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2421 return (s->last_lit == s->lit_bufsize-1);
2422 /* We avoid equality with lit_bufsize because of wraparound at 64K
2423 * on 16 bit machines and because stored blocks are restricted to
2428 /* ===========================================================================
2429 * Send the block data compressed using the given Huffman trees
2431 local void compress_block(s, ltree, dtree)
2433 ct_data *ltree; /* literal tree */
2434 ct_data *dtree; /* distance tree */
2436 unsigned dist; /* distance of matched string */
2437 int lc; /* match length or unmatched char (if dist == 0) */
2438 unsigned lx = 0; /* running index in l_buf */
2439 unsigned code; /* the code to send */
2440 int extra; /* number of extra bits to send */
2442 if (s->last_lit != 0) do {
2443 dist = s->d_buf[lx];
2444 lc = s->l_buf[lx++];
2446 send_code(s, lc, ltree); /* send a literal byte */
2447 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2449 /* Here, lc is the match length - MIN_MATCH */
2450 code = length_code[lc];
2451 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2452 extra = extra_lbits[code];
2454 lc -= base_length[code];
2455 send_bits(s, lc, extra); /* send the extra length bits */
2457 dist--; /* dist is now the match distance - 1 */
2458 code = d_code(dist);
2459 Assert (code < D_CODES, "bad d_code");
2461 send_code(s, code, dtree); /* send the distance code */
2462 extra = extra_dbits[code];
2464 dist -= base_dist[code];
2465 send_bits(s, dist, extra); /* send the extra distance bits */
2467 } /* literal or match pair ? */
2469 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2470 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2472 } while (lx < s->last_lit);
2474 send_code(s, END_BLOCK, ltree);
2475 s->last_eob_len = ltree[END_BLOCK].Len;
2478 /* ===========================================================================
2479 * Set the data type to ASCII or BINARY, using a crude approximation:
2480 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2481 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2482 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2484 local void set_data_type(s)
2488 unsigned ascii_freq = 0;
2489 unsigned bin_freq = 0;
2490 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2491 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2492 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2493 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2496 /* ===========================================================================
2497 * Reverse the first len bits of a code, using straightforward code (a faster
2498 * method would use a table)
2499 * IN assertion: 1 <= len <= 15
2501 local unsigned bi_reverse(code, len)
2502 unsigned code; /* the value to invert */
2503 int len; /* its bit length */
2505 register unsigned res = 0;
2508 code >>= 1, res <<= 1;
2509 } while (--len > 0);
2513 /* ===========================================================================
2514 * Flush the bit buffer, keeping at most 7 bits in it.
2516 local void bi_flush(s)
2519 if (s->bi_valid == 16) {
2520 put_short(s, s->bi_buf);
2523 } else if (s->bi_valid >= 8) {
2524 put_byte(s, (Byte)s->bi_buf);
2530 /* ===========================================================================
2531 * Flush the bit buffer and align the output on a byte boundary
2533 local void bi_windup(s)
2536 if (s->bi_valid > 8) {
2537 put_short(s, s->bi_buf);
2538 } else if (s->bi_valid > 0) {
2539 put_byte(s, (Byte)s->bi_buf);
2544 s->bits_sent = (s->bits_sent+7) & ~7;
2548 /* ===========================================================================
2549 * Copy a stored block, storing first the length and its
2550 * one's complement if requested.
2552 local void copy_block(s, buf, len, header)
2554 charf *buf; /* the input data */
2555 unsigned len; /* its length */
2556 int header; /* true if block header must be written */
2558 bi_windup(s); /* align on byte boundary */
2559 s->last_eob_len = 8; /* enough lookahead for inflate */
2562 put_short(s, (ush)len);
2563 put_short(s, (ush)~len);
2565 s->bits_sent += 2*16;
2569 s->bits_sent += (ulg)len<<3;
2572 put_byte(s, *buf++);
2578 /* infblock.h -- header to use infblock.c
2579 * Copyright (C) 1995 Mark Adler
2580 * For conditions of distribution and use, see copyright notice in zlib.h
2583 /* WARNING: this file should *not* be used by applications. It is
2584 part of the implementation of the compression library and is
2585 subject to change. Applications should only use zlib.h.
2588 struct inflate_blocks_state;
2589 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2591 local inflate_blocks_statef * inflate_blocks_new OF((
2593 check_func c, /* check function */
2594 uInt w)); /* window size */
2596 local int inflate_blocks OF((
2597 inflate_blocks_statef *,
2599 int)); /* initial return code */
2601 local void inflate_blocks_reset OF((
2602 inflate_blocks_statef *,
2604 uLongf *)); /* check value on output */
2606 local int inflate_blocks_free OF((
2607 inflate_blocks_statef *,
2609 uLongf *)); /* check value on output */
2611 local int inflate_addhistory OF((
2612 inflate_blocks_statef *,
2615 local int inflate_packet_flush OF((
2616 inflate_blocks_statef *));
2619 /* inftrees.h -- header to use inftrees.c
2620 * Copyright (C) 1995 Mark Adler
2621 * For conditions of distribution and use, see copyright notice in zlib.h
2624 /* WARNING: this file should *not* be used by applications. It is
2625 part of the implementation of the compression library and is
2626 subject to change. Applications should only use zlib.h.
2629 /* Huffman code lookup table entry--this entry is four bytes for machines
2630 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2632 typedef struct inflate_huft_s FAR inflate_huft;
2634 struct inflate_huft_s {
2637 Byte Exop; /* number of extra bits or operation */
2638 Byte Bits; /* number of bits in this code or subcode */
2640 uInt Nalloc; /* number of these allocated here */
2641 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2642 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2644 uInt Base; /* literal, length base, or distance base */
2645 inflate_huft *Next; /* pointer to next level of table */
2650 local uInt inflate_hufts;
2653 local int inflate_trees_bits OF((
2654 uIntf *, /* 19 code lengths */
2655 uIntf *, /* bits tree desired/actual depth */
2656 inflate_huft * FAR *, /* bits tree result */
2657 z_stream *)); /* for zalloc, zfree functions */
2659 local int inflate_trees_dynamic OF((
2660 uInt, /* number of literal/length codes */
2661 uInt, /* number of distance codes */
2662 uIntf *, /* that many (total) code lengths */
2663 uIntf *, /* literal desired/actual bit depth */
2664 uIntf *, /* distance desired/actual bit depth */
2665 inflate_huft * FAR *, /* literal/length tree result */
2666 inflate_huft * FAR *, /* distance tree result */
2667 z_stream *)); /* for zalloc, zfree functions */
2669 local int inflate_trees_fixed OF((
2670 uIntf *, /* literal desired/actual bit depth */
2671 uIntf *, /* distance desired/actual bit depth */
2672 inflate_huft * FAR *, /* literal/length tree result */
2673 inflate_huft * FAR *)); /* distance tree result */
2675 local int inflate_trees_free OF((
2676 inflate_huft *, /* tables to free */
2677 z_stream *)); /* for zfree function */
2681 /* infcodes.h -- header to use infcodes.c
2682 * Copyright (C) 1995 Mark Adler
2683 * For conditions of distribution and use, see copyright notice in zlib.h
2686 /* WARNING: this file should *not* be used by applications. It is
2687 part of the implementation of the compression library and is
2688 subject to change. Applications should only use zlib.h.
2691 struct inflate_codes_state;
2692 typedef struct inflate_codes_state FAR inflate_codes_statef;
2694 local inflate_codes_statef *inflate_codes_new OF((
2696 inflate_huft *, inflate_huft *,
2699 local int inflate_codes OF((
2700 inflate_blocks_statef *,
2704 local void inflate_codes_free OF((
2705 inflate_codes_statef *,
2710 /* inflate.c -- zlib interface to inflate modules
2711 * Copyright (C) 1995 Mark Adler
2712 * For conditions of distribution and use, see copyright notice in zlib.h
2715 /* inflate private state */
2716 struct internal_state {
2720 METHOD, /* waiting for method byte */
2721 FLAG, /* waiting for flag byte */
2722 BLOCKS, /* decompressing blocks */
2723 CHECK4, /* four check bytes to go */
2724 CHECK3, /* three check bytes to go */
2725 CHECK2, /* two check bytes to go */
2726 CHECK1, /* one check byte to go */
2727 DONE, /* finished check, done */
2728 ZBAD} /* got an error--stay here */
2729 mode; /* current inflate mode */
2731 /* mode dependent information */
2733 uInt method; /* if FLAGS, method byte */
2735 uLong was; /* computed check value */
2736 uLong need; /* stream check value */
2737 } check; /* if CHECK, check values to compare */
2738 uInt marker; /* if ZBAD, inflateSync's marker bytes count */
2739 } sub; /* submode */
2741 /* mode independent information */
2742 int nowrap; /* flag for no wrapper */
2743 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2744 inflate_blocks_statef
2745 *blocks; /* current inflate_blocks state */
2755 if (z == Z_NULL || z->state == Z_NULL)
2756 return Z_STREAM_ERROR;
2757 z->total_in = z->total_out = 0;
2759 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2760 inflate_blocks_reset(z->state->blocks, z, &c);
2761 Trace((stderr, "inflate: reset\n"));
2771 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2772 return Z_STREAM_ERROR;
2773 if (z->state->blocks != Z_NULL)
2774 inflate_blocks_free(z->state->blocks, z, &c);
2775 ZFREE(z, z->state, sizeof(struct internal_state));
2777 Trace((stderr, "inflate: end\n"));
2782 int inflateInit2(z, w)
2786 /* initialize state */
2788 return Z_STREAM_ERROR;
2789 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2790 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2791 if ((z->state = (struct internal_state FAR *)
2792 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2794 z->state->blocks = Z_NULL;
2796 /* handle undocumented nowrap option (no zlib header or check) */
2797 z->state->nowrap = 0;
2801 z->state->nowrap = 1;
2804 /* set window size */
2805 if (w < 8 || w > 15)
2808 return Z_STREAM_ERROR;
2810 z->state->wbits = (uInt)w;
2812 /* create inflate_blocks state */
2813 if ((z->state->blocks =
2814 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2820 Trace((stderr, "inflate: allocated\n"));
2831 return inflateInit2(z, DEF_WBITS);
2835 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2836 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2845 if (z == Z_NULL || z->next_in == Z_NULL)
2846 return Z_STREAM_ERROR;
2848 while (1) switch (z->state->mode)
2852 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2854 z->state->mode = ZBAD;
2855 z->msg = "unknown compression method";
2856 z->state->sub.marker = 5; /* can't try inflateSync */
2859 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2861 z->state->mode = ZBAD;
2862 z->msg = "invalid window size";
2863 z->state->sub.marker = 5; /* can't try inflateSync */
2866 z->state->mode = FLAG;
2869 if ((b = NEXTBYTE) & 0x20)
2871 z->state->mode = ZBAD;
2872 z->msg = "invalid reserved bit";
2873 z->state->sub.marker = 5; /* can't try inflateSync */
2876 if (((z->state->sub.method << 8) + b) % 31)
2878 z->state->mode = ZBAD;
2879 z->msg = "incorrect header check";
2880 z->state->sub.marker = 5; /* can't try inflateSync */
2883 Trace((stderr, "inflate: zlib header ok\n"));
2884 z->state->mode = BLOCKS;
2886 r = inflate_blocks(z->state->blocks, z, r);
2887 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2888 r = inflate_packet_flush(z->state->blocks);
2889 if (r == Z_DATA_ERROR)
2891 z->state->mode = ZBAD;
2892 z->state->sub.marker = 0; /* can try inflateSync */
2895 if (r != Z_STREAM_END)
2898 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2899 if (z->state->nowrap)
2901 z->state->mode = DONE;
2904 z->state->mode = CHECK4;
2907 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2908 z->state->mode = CHECK3;
2911 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2912 z->state->mode = CHECK2;
2915 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2916 z->state->mode = CHECK1;
2919 z->state->sub.check.need += (uLong)NEXTBYTE;
2921 if (z->state->sub.check.was != z->state->sub.check.need)
2923 z->state->mode = ZBAD;
2924 z->msg = "incorrect data check";
2925 z->state->sub.marker = 5; /* can't try inflateSync */
2928 Trace((stderr, "inflate: zlib check ok\n"));
2929 z->state->mode = DONE;
2931 return Z_STREAM_END;
2933 return Z_DATA_ERROR;
2935 return Z_STREAM_ERROR;
2939 if (f != Z_PACKET_FLUSH)
2941 z->state->mode = ZBAD;
2942 z->state->sub.marker = 0; /* can try inflateSync */
2943 return Z_DATA_ERROR;
2947 * This subroutine adds the data at next_in/avail_in to the output history
2948 * without performing any output. The output buffer must be "caught up";
2949 * i.e. no pending output (hence s->read equals s->write), and the state must
2950 * be BLOCKS (i.e. we should be willing to see the start of a series of
2951 * BLOCKS). On exit, the output will also be caught up, and the checksum
2952 * will have been updated if need be.
2955 int inflateIncomp(z)
2958 if (z->state->mode != BLOCKS)
2959 return Z_DATA_ERROR;
2960 return inflate_addhistory(z->state->blocks, z);
2967 uInt n; /* number of bytes to look at */
2968 Bytef *p; /* pointer to bytes */
2969 uInt m; /* number of marker bytes found in a row */
2970 uLong r, w; /* temporaries to save total_in and total_out */
2973 if (z == Z_NULL || z->state == Z_NULL)
2974 return Z_STREAM_ERROR;
2975 if (z->state->mode != ZBAD)
2977 z->state->mode = ZBAD;
2978 z->state->sub.marker = 0;
2980 if ((n = z->avail_in) == 0)
2983 m = z->state->sub.marker;
2988 if (*p == (Byte)(m < 2 ? 0 : 0xff))
2998 z->total_in += p - z->next_in;
3001 z->state->sub.marker = m;
3003 /* return no joy or set up to restart on a new block */
3005 return Z_DATA_ERROR;
3006 r = z->total_in; w = z->total_out;
3008 z->total_in = r; z->total_out = w;
3009 z->state->mode = BLOCKS;
3017 /* infutil.h -- types and macros common to blocks and codes
3018 * Copyright (C) 1995 Mark Adler
3019 * For conditions of distribution and use, see copyright notice in zlib.h
3022 /* WARNING: this file should *not* be used by applications. It is
3023 part of the implementation of the compression library and is
3024 subject to change. Applications should only use zlib.h.
3027 /* inflate blocks semi-private state */
3028 struct inflate_blocks_state {
3032 TYPE, /* get type bits (3, including end bit) */
3033 LENS, /* get lengths for stored */
3034 STORED, /* processing stored block */
3035 TABLE, /* get table lengths */
3036 BTREE, /* get bit lengths tree for a dynamic block */
3037 DTREE, /* get length, distance trees for a dynamic block */
3038 CODES, /* processing fixed or dynamic block */
3039 DRY, /* output remaining window bytes */
3040 DONEB, /* finished last block, done */
3041 BADB} /* got a data error--stuck here */
3042 mode; /* current inflate_block mode */
3044 /* mode dependent information */
3046 uInt left; /* if STORED, bytes left to copy */
3048 uInt table; /* table lengths (14 bits) */
3049 uInt index; /* index into blens (or border) */
3050 uIntf *blens; /* bit lengths of codes */
3051 uInt bb; /* bit length tree depth */
3052 inflate_huft *tb; /* bit length decoding tree */
3053 int nblens; /* # elements allocated at blens */
3054 } trees; /* if DTREE, decoding info for trees */
3056 inflate_huft *tl, *td; /* trees to free */
3057 inflate_codes_statef
3059 } decode; /* if CODES, current state */
3060 } sub; /* submode */
3061 uInt last; /* true if this block is the last block */
3063 /* mode independent information */
3064 uInt bitk; /* bits in bit buffer */
3065 uLong bitb; /* bit buffer */
3066 Bytef *window; /* sliding window */
3067 Bytef *end; /* one byte after sliding window */
3068 Bytef *read; /* window read pointer */
3069 Bytef *write; /* window write pointer */
3070 check_func checkfn; /* check function */
3071 uLong check; /* check on output */
3076 /* defines for inflate input/output */
3077 /* update pointers and return */
3078 #define UPDBITS {s->bitb=b;s->bitk=k;}
3079 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3080 #define UPDOUT {s->write=q;}
3081 #define UPDATE {UPDBITS UPDIN UPDOUT}
3082 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3083 /* get bytes and bits */
3084 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3085 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3086 #define NEXTBYTE (n--,*p++)
3087 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3088 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3090 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3091 #define LOADOUT {q=s->write;m=WAVAIL;}
3092 #define ZWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3093 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3094 #define NEEDOUT {if(m==0){ZWRAP if(m==0){FLUSH ZWRAP if(m==0) LEAVE}}r=Z_OK;}
3095 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3096 /* load local pointers */
3097 #define LOAD {LOADIN LOADOUT}
3099 /* And'ing with mask[n] masks the lower n bits */
3100 local uInt inflate_mask[] = {
3102 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3103 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3106 /* copy as much as possible from the sliding window to the output area */
3107 local int inflate_flush OF((
3108 inflate_blocks_statef *,
3113 /* inffast.h -- header to use inffast.c
3114 * Copyright (C) 1995 Mark Adler
3115 * For conditions of distribution and use, see copyright notice in zlib.h
3118 /* WARNING: this file should *not* be used by applications. It is
3119 part of the implementation of the compression library and is
3120 subject to change. Applications should only use zlib.h.
3123 local int inflate_fast OF((
3128 inflate_blocks_statef *,
3133 /* infblock.c -- interpret and process block types to last block
3134 * Copyright (C) 1995 Mark Adler
3135 * For conditions of distribution and use, see copyright notice in zlib.h
3138 /* Table for deflate from PKZIP's appnote.txt. */
3139 local uInt border[] = { /* Order of the bit length code lengths */
3140 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3143 Notes beyond the 1.93a appnote.txt:
3145 1. Distance pointers never point before the beginning of the output
3147 2. Distance pointers can point back across blocks, up to 32k away.
3148 3. There is an implied maximum of 7 bits for the bit length table and
3149 15 bits for the actual data.
3150 4. If only one code exists, then it is encoded using one bit. (Zero
3151 would be more efficient, but perhaps a little confusing.) If two
3152 codes exist, they are coded using one bit each (0 and 1).
3153 5. There is no way of sending zero distance codes--a dummy must be
3154 sent if there are none. (History: a pre 2.0 version of PKZIP would
3155 store blocks with no distance codes, but this was discovered to be
3156 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3157 zero distance codes, which is sent as one code of zero bits in
3159 6. There are up to 286 literal/length codes. Code 256 represents the
3160 end-of-block. Note however that the static length tree defines
3161 288 codes just to fill out the Huffman codes. Codes 286 and 287
3162 cannot be used though, since there is no length base or extra bits
3163 defined for them. Similarily, there are up to 30 distance codes.
3164 However, static trees define 32 codes (all 5 bits) to fill out the
3165 Huffman codes, but the last two had better not show up in the data.
3166 7. Unzip can check dynamic Huffman blocks for complete code sets.
3167 The exception is that a single code would not be complete (see #4).
3168 8. The five bits following the block type is really the number of
3169 literal codes sent minus 257.
3170 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3171 (1+6+6). Therefore, to output three times the length, you output
3172 three codes (1+1+1), whereas to output four times the same length,
3173 you only need two codes (1+3). Hmm.
3174 10. In the tree reconstruction algorithm, Code = Code + Increment
3175 only if BitLength(i) is not zero. (Pretty obvious.)
3176 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3177 12. Note: length code 284 can represent 227-258, but length code 285
3178 really is 258. The last length deserves its own, short code
3179 since it gets used a lot in very redundant files. The length
3180 258 is special since 258 - 3 (the min match length) is 255.
3181 13. The literal/length and distance code bit lengths are read as a
3182 single stream of lengths. It is possible (and advantageous) for
3183 a repeat code (16, 17, or 18) to go across the boundary between
3184 the two sets of lengths.
3188 local void inflate_blocks_reset(s, z, c)
3189 inflate_blocks_statef *s;
3193 if (s->checkfn != Z_NULL)
3195 if (s->mode == BTREE || s->mode == DTREE)
3196 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3197 if (s->mode == CODES)
3199 inflate_codes_free(s->sub.decode.codes, z);
3200 inflate_trees_free(s->sub.decode.td, z);
3201 inflate_trees_free(s->sub.decode.tl, z);
3206 s->read = s->write = s->window;
3207 if (s->checkfn != Z_NULL)
3208 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3209 Trace((stderr, "inflate: blocks reset\n"));
3213 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
3218 inflate_blocks_statef *s;
3220 if ((s = (inflate_blocks_statef *)ZALLOC
3221 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3223 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3225 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3228 s->end = s->window + w;
3231 Trace((stderr, "inflate: blocks allocated\n"));
3232 inflate_blocks_reset(s, z, &s->check);
3237 local int inflate_blocks(s, z, r)
3238 inflate_blocks_statef *s;
3242 uInt t; /* temporary storage */
3243 uLong b; /* bit buffer */
3244 uInt k; /* bits in bit buffer */
3245 Bytef *p; /* input data pointer */
3246 uInt n; /* bytes available there */
3247 Bytef *q; /* output window write pointer */
3248 uInt m; /* bytes to end of window or read pointer */
3250 /* copy input/output information to locals (UPDATE macro restores) */
3253 /* process input based on current state */
3254 while (1) switch (s->mode)
3262 case 0: /* stored */
3263 Trace((stderr, "inflate: stored block%s\n",
3264 s->last ? " (last)" : ""));
3266 t = k & 7; /* go to byte boundary */
3268 s->mode = LENS; /* get length of stored block */
3271 Trace((stderr, "inflate: fixed codes block%s\n",
3272 s->last ? " (last)" : ""));
3275 inflate_huft *tl, *td;
3277 inflate_trees_fixed(&bl, &bd, &tl, &td);
3278 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3279 if (s->sub.decode.codes == Z_NULL)
3284 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3285 s->sub.decode.td = Z_NULL;
3290 case 2: /* dynamic */
3291 Trace((stderr, "inflate: dynamic codes block%s\n",
3292 s->last ? " (last)" : ""));
3296 case 3: /* illegal */
3299 z->msg = "invalid block type";
3306 if (((~b) >> 16) != (b & 0xffff))
3309 z->msg = "invalid stored block lengths";
3313 s->sub.left = (uInt)b & 0xffff;
3314 b = k = 0; /* dump bits */
3315 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3316 s->mode = s->sub.left ? STORED : TYPE;
3328 if ((s->sub.left -= t) != 0)
3330 Tracev((stderr, "inflate: stored end, %lu total out\n",
3331 z->total_out + (q >= s->read ? q - s->read :
3332 (s->end - s->read) + (q - s->window))));
3333 s->mode = s->last ? DRY : TYPE;
3337 s->sub.trees.table = t = (uInt)b & 0x3fff;
3338 #ifndef PKZIP_BUG_WORKAROUND
3339 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3342 z->msg = "too many length or distance symbols";
3347 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3350 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3355 s->sub.trees.nblens = t;
3357 s->sub.trees.index = 0;
3358 Tracev((stderr, "inflate: table sizes ok\n"));
3361 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3364 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3367 while (s->sub.trees.index < 19)
3368 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3369 s->sub.trees.bb = 7;
3370 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3371 &s->sub.trees.tb, z);
3375 if (r == Z_DATA_ERROR)
3379 s->sub.trees.index = 0;
3380 Tracev((stderr, "inflate: bits tree ok\n"));
3383 while (t = s->sub.trees.table,
3384 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3389 t = s->sub.trees.bb;
3391 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3392 t = h->word.what.Bits;
3397 s->sub.trees.blens[s->sub.trees.index++] = c;
3399 else /* c == 16..18 */
3401 i = c == 18 ? 7 : c - 14;
3402 j = c == 18 ? 11 : 3;
3405 j += (uInt)b & inflate_mask[i];
3407 i = s->sub.trees.index;
3408 t = s->sub.trees.table;
3409 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3413 z->msg = "invalid bit length repeat";
3417 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3419 s->sub.trees.blens[i++] = c;
3421 s->sub.trees.index = i;
3424 inflate_trees_free(s->sub.trees.tb, z);
3425 s->sub.trees.tb = Z_NULL;
3428 inflate_huft *tl, *td;
3429 inflate_codes_statef *c;
3431 bl = 9; /* must be <= 9 for lookahead assumptions */
3432 bd = 6; /* must be <= 9 for lookahead assumptions */
3433 t = s->sub.trees.table;
3434 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3435 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3438 if (t == (uInt)Z_DATA_ERROR)
3443 Tracev((stderr, "inflate: trees ok\n"));
3444 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3446 inflate_trees_free(td, z);
3447 inflate_trees_free(tl, z);
3451 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3452 s->sub.decode.codes = c;
3453 s->sub.decode.tl = tl;
3454 s->sub.decode.td = td;
3459 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3460 return inflate_flush(s, z, r);
3462 inflate_codes_free(s->sub.decode.codes, z);
3463 inflate_trees_free(s->sub.decode.td, z);
3464 inflate_trees_free(s->sub.decode.tl, z);
3466 Tracev((stderr, "inflate: codes end, %lu total out\n",
3467 z->total_out + (q >= s->read ? q - s->read :
3468 (s->end - s->read) + (q - s->window))));
3474 if (k > 7) /* return unused byte, if any */
3476 Assert(k < 16, "inflate_codes grabbed too many bytes")
3479 p--; /* can always return one */
3484 if (s->read != s->write)
3500 local int inflate_blocks_free(s, z, c)
3501 inflate_blocks_statef *s;
3505 inflate_blocks_reset(s, z, c);
3506 ZFREE(z, s->window, s->end - s->window);
3507 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3508 Trace((stderr, "inflate: blocks freed\n"));
3513 * This subroutine adds the data at next_in/avail_in to the output history
3514 * without performing any output. The output buffer must be "caught up";
3515 * i.e. no pending output (hence s->read equals s->write), and the state must
3516 * be BLOCKS (i.e. we should be willing to see the start of a series of
3517 * BLOCKS). On exit, the output will also be caught up, and the checksum
3518 * will have been updated if need be.
3520 local int inflate_addhistory(s, z)
3521 inflate_blocks_statef *s;
3524 uLong b; /* bit buffer */ /* NOT USED HERE */
3525 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3526 uInt t; /* temporary storage */
3527 Bytef *p; /* input data pointer */
3528 uInt n; /* bytes available there */
3529 Bytef *q; /* output window write pointer */
3530 uInt m; /* bytes to end of window or read pointer */
3532 if (s->read != s->write)
3533 return Z_STREAM_ERROR;
3534 if (s->mode != TYPE)
3535 return Z_DATA_ERROR;
3537 /* we're ready to rock */
3539 /* while there is input ready, copy to output buffer, moving
3540 * pointers as needed.
3543 t = n; /* how many to do */
3544 /* is there room until end of buffer? */
3546 /* update check information */
3547 if (s->checkfn != Z_NULL)
3548 s->check = (*s->checkfn)(s->check, q, t);
3554 s->read = q; /* drag read pointer forward */
3555 /* ZWRAP */ /* expand ZWRAP macro by hand to handle s->read */
3557 s->read = q = s->window;
3567 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3568 * a `stored' block type value but not the (zero) length bytes.
3570 local int inflate_packet_flush(s)
3571 inflate_blocks_statef *s;
3573 if (s->mode != LENS)
3574 return Z_DATA_ERROR;
3581 /* inftrees.c -- generate Huffman trees for efficient decoding
3582 * Copyright (C) 1995 Mark Adler
3583 * For conditions of distribution and use, see copyright notice in zlib.h
3586 /* simplify the use of the inflate_huft type with some defines */
3587 #define base more.Base
3588 #define next more.Next
3589 #define exop word.what.Exop
3590 #define bits word.what.Bits
3593 local int huft_build OF((
3594 uIntf *, /* code lengths in bits */
3595 uInt, /* number of codes */
3596 uInt, /* number of "simple" codes */
3597 uIntf *, /* list of base values for non-simple codes */
3598 uIntf *, /* list of extra bits for non-simple codes */
3599 inflate_huft * FAR*,/* result: starting table */
3600 uIntf *, /* maximum lookup bits (returns actual) */
3601 z_stream *)); /* for zalloc function */
3603 local voidpf falloc OF((
3604 voidpf, /* opaque pointer (not used) */
3605 uInt, /* number of items */
3606 uInt)); /* size of item */
3608 local void ffree OF((
3609 voidpf q, /* opaque pointer (not used) */
3610 voidpf p, /* what to free (not used) */
3611 uInt n)); /* number of bytes (not used) */
3613 /* Tables for deflate from PKZIP's appnote.txt. */
3614 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3615 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3616 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3617 /* actually lengths - 2; also see note #13 above about 258 */
3618 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3619 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3620 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3621 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3622 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3623 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3624 8193, 12289, 16385, 24577};
3625 local uInt cpdext[] = { /* Extra bits for distance codes */
3626 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3627 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3631 Huffman code decoding is performed using a multi-level table lookup.
3632 The fastest way to decode is to simply build a lookup table whose
3633 size is determined by the longest code. However, the time it takes
3634 to build this table can also be a factor if the data being decoded
3635 is not very long. The most common codes are necessarily the
3636 shortest codes, so those codes dominate the decoding time, and hence
3637 the speed. The idea is you can have a shorter table that decodes the
3638 shorter, more probable codes, and then point to subsidiary tables for
3639 the longer codes. The time it costs to decode the longer codes is
3640 then traded against the time it takes to make longer tables.
3642 This results of this trade are in the variables lbits and dbits
3643 below. lbits is the number of bits the first level table for literal/
3644 length codes can decode in one step, and dbits is the same thing for
3645 the distance codes. Subsequent tables are also less than or equal to
3646 those sizes. These values may be adjusted either when all of the
3647 codes are shorter than that, in which case the longest code length in
3648 bits is used, or when the shortest code is *longer* than the requested
3649 table size, in which case the length of the shortest code in bits is
3652 There are two different values for the two tables, since they code a
3653 different number of possibilities each. The literal/length table
3654 codes 286 possible values, or in a flat code, a little over eight
3655 bits. The distance table codes 30 possible values, or a little less
3656 than five bits, flat. The optimum values for speed end up being
3657 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3658 The optimum values may differ though from machine to machine, and
3659 possibly even between compilers. Your mileage may vary.
3663 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3664 #define BMAX 15 /* maximum bit length of any code */
3665 #define N_MAX 288 /* maximum number of codes in any set */
3671 local int huft_build(b, n, s, d, e, t, m, zs)
3672 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3673 uInt n; /* number of codes (assumed <= N_MAX) */
3674 uInt s; /* number of simple-valued codes (0..s-1) */
3675 uIntf *d; /* list of base values for non-simple codes */
3676 uIntf *e; /* list of extra bits for non-simple codes */
3677 inflate_huft * FAR *t; /* result: starting table */
3678 uIntf *m; /* maximum lookup bits, returns actual */
3679 z_stream *zs; /* for zalloc function */
3680 /* Given a list of code lengths and a maximum table size, make a set of
3681 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3682 if the given code set is incomplete (the tables are still built in this
3683 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3684 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3687 uInt a; /* counter for codes of length k */
3688 uInt c[BMAX+1]; /* bit length count table */
3689 uInt f; /* i repeats in table every f entries */
3690 int g; /* maximum code length */
3691 int h; /* table level */
3692 register uInt i; /* counter, current code */
3693 register uInt j; /* counter */
3694 register int k; /* number of bits in current code */
3695 int l; /* bits per table (returned in m) */
3696 register uIntf *p; /* pointer into c[], b[], or v[] */
3697 inflate_huft *q; /* points to current table */
3698 struct inflate_huft_s r; /* table entry for structure assignment */
3699 inflate_huft *u[BMAX]; /* table stack */
3700 uInt v[N_MAX]; /* values in order of bit length */
3701 register int w; /* bits before this table == (l * h) */
3702 uInt x[BMAX+1]; /* bit offsets, then code stack */
3703 uIntf *xp; /* pointer into x */
3704 int y; /* number of dummy codes added */
3705 uInt z; /* number of entries in current table */
3708 /* Generate counts for each bit length */
3710 #define C0 *p++ = 0;
3711 #define C2 C0 C0 C0 C0
3712 #define C4 C2 C2 C2 C2
3713 C4 /* clear c[]--assume BMAX+1 is 16 */
3716 c[*p++]++; /* assume all entries <= BMAX */
3718 if (c[0] == n) /* null input--all zero length codes */
3720 *t = (inflate_huft *)Z_NULL;
3726 /* Find minimum and maximum length, bound *m by those */
3728 for (j = 1; j <= BMAX; j++)
3731 k = j; /* minimum code length */
3734 for (i = BMAX; i; i--)
3737 g = i; /* maximum code length */
3743 /* Adjust last length count to fill out codes, if needed */
3744 for (y = 1 << j; j < i; j++, y <<= 1)
3745 if ((y -= c[j]) < 0)
3746 return Z_DATA_ERROR;
3747 if ((y -= c[i]) < 0)
3748 return Z_DATA_ERROR;
3752 /* Generate starting offsets into the value table for each length */
3754 p = c + 1; xp = x + 2;
3755 while (--i) { /* note that i == g from above */
3756 *xp++ = (j += *p++);
3760 /* Make a table of values in order of bit lengths */
3763 if ((j = *p++) != 0)
3768 /* Generate the Huffman codes and for each, make the table entries */
3769 x[0] = i = 0; /* first Huffman code is zero */
3770 p = v; /* grab values in bit order */
3771 h = -1; /* no tables yet--level -1 */
3772 w = -l; /* bits decoded == (l * h) */
3773 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3774 q = (inflate_huft *)Z_NULL; /* ditto */
3777 /* go through the bit lengths (k already is bits in shortest code) */
3783 /* here i is the Huffman code of length k bits for value *p */
3784 /* make tables up to required level */
3788 w += l; /* previous table always l bits */
3790 /* compute minimum size table less than or equal to l bits */
3791 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3792 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3793 { /* too few codes for k-w bit table */
3794 f -= a + 1; /* deduct codes from patterns left */
3797 while (++j < z) /* try smaller tables up to z bits */
3799 if ((f <<= 1) <= *++xp)
3800 break; /* enough codes to use up j bits */
3801 f -= *xp; /* else deduct codes from patterns */
3804 z = 1 << j; /* table entries for j-bit table */
3806 /* allocate and link in new table */
3807 if ((q = (inflate_huft *)ZALLOC
3808 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3811 inflate_trees_free(u[0], zs);
3812 return Z_MEM_ERROR; /* not enough memory */
3814 q->word.Nalloc = z + 1;
3816 inflate_hufts += z + 1;
3818 *t = q + 1; /* link to list for huft_free() */
3819 *(t = &(q->next)) = Z_NULL;
3820 u[h] = ++q; /* table starts after link */
3822 /* connect to last table, if there is one */
3825 x[h] = i; /* save pattern for backing up */
3826 r.bits = (Byte)l; /* bits to dump before this table */
3827 r.exop = (Byte)j; /* bits in this table */
3828 r.next = q; /* pointer to this table */
3829 j = i >> (w - l); /* (get around Turbo C bug) */
3830 u[h-1][j] = r; /* connect to last table */
3834 /* set up table entry in r */
3835 r.bits = (Byte)(k - w);
3837 r.exop = 128 + 64; /* out of values--invalid code */
3840 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3841 r.base = *p++; /* simple code is just the value */
3845 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3846 r.base = d[*p++ - s];
3849 /* fill code-like entries with r */
3851 for (j = i >> w; j < z; j += f)
3854 /* backwards increment the k-bit code i */
3855 for (j = 1 << (k - 1); i & j; j >>= 1)
3859 /* backup over finished tables */
3860 while ((i & ((1 << w) - 1)) != x[h])
3862 h--; /* don't need to update q */
3869 /* Return Z_BUF_ERROR if we were given an incomplete table */
3870 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3874 local int inflate_trees_bits(c, bb, tb, z)
3875 uIntf *c; /* 19 code lengths */
3876 uIntf *bb; /* bits tree desired/actual depth */
3877 inflate_huft * FAR *tb; /* bits tree result */
3878 z_stream *z; /* for zfree function */
3882 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3883 if (r == Z_DATA_ERROR)
3884 z->msg = "oversubscribed dynamic bit lengths tree";
3885 else if (r == Z_BUF_ERROR)
3887 inflate_trees_free(*tb, z);
3888 z->msg = "incomplete dynamic bit lengths tree";
3895 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3896 uInt nl; /* number of literal/length codes */
3897 uInt nd; /* number of distance codes */
3898 uIntf *c; /* that many (total) code lengths */
3899 uIntf *bl; /* literal desired/actual bit depth */
3900 uIntf *bd; /* distance desired/actual bit depth */
3901 inflate_huft * FAR *tl; /* literal/length tree result */
3902 inflate_huft * FAR *td; /* distance tree result */
3903 z_stream *z; /* for zfree function */
3907 /* build literal/length tree */
3908 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3910 if (r == Z_DATA_ERROR)
3911 z->msg = "oversubscribed literal/length tree";
3912 else if (r == Z_BUF_ERROR)
3914 inflate_trees_free(*tl, z);
3915 z->msg = "incomplete literal/length tree";
3921 /* build distance tree */
3922 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3924 if (r == Z_DATA_ERROR)
3925 z->msg = "oversubscribed literal/length tree";
3926 else if (r == Z_BUF_ERROR) {
3927 #ifdef PKZIP_BUG_WORKAROUND
3931 inflate_trees_free(*td, z);
3932 z->msg = "incomplete literal/length tree";
3935 inflate_trees_free(*tl, z);
3945 /* build fixed tables only once--keep them here */
3946 #ifdef MULTI_THREADED
3947 local volatile int fixed_lock = 0;
3949 local int fixed_built = 0;
3950 #define FIXEDH 530 /* number of hufts used by fixed tables */
3951 local uInt fixed_left = FIXEDH;
3952 local inflate_huft fixed_mem[FIXEDH];
3953 local uInt fixed_bl;
3954 local uInt fixed_bd;
3955 local inflate_huft *fixed_tl;
3956 local inflate_huft *fixed_td;
3959 local voidpf falloc(q, n, s)
3960 voidpf q; /* opaque pointer (not used) */
3961 uInt n; /* number of items */
3962 uInt s; /* size of item */
3964 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
3965 "inflate_trees falloc overflow");
3966 if (q) s++; /* to make some compilers happy */
3968 return (voidpf)(fixed_mem + fixed_left);
3972 local void ffree(q, p, n)
3977 Assert(0, "inflate_trees ffree called!");
3978 if (q) q = p; /* to make some compilers happy */
3982 local int inflate_trees_fixed(bl, bd, tl, td)
3983 uIntf *bl; /* literal desired/actual bit depth */
3984 uIntf *bd; /* distance desired/actual bit depth */
3985 inflate_huft * FAR *tl; /* literal/length tree result */
3986 inflate_huft * FAR *td; /* distance tree result */
3988 /* build fixed tables if not built already--lock out other instances */
3989 #ifdef MULTI_THREADED
3990 while (++fixed_lock > 1)
3995 int k; /* temporary variable */
3996 unsigned c[288]; /* length list for huft_build */
3997 z_stream z; /* for falloc function */
3999 /* set up fake z_stream for memory routines */
4005 for (k = 0; k < 144; k++)
4007 for (; k < 256; k++)
4009 for (; k < 280; k++)
4011 for (; k < 288; k++)
4014 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4016 /* distance table */
4017 for (k = 0; k < 30; k++)
4020 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4025 #ifdef MULTI_THREADED
4036 local int inflate_trees_free(t, z)
4037 inflate_huft *t; /* table to free */
4038 z_stream *z; /* for zfree function */
4039 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4040 list of the tables it made, with the links in a dummy first entry of
4043 register inflate_huft *p, *q;
4045 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4050 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4057 /* infcodes.c -- process literals and length/distance pairs
4058 * Copyright (C) 1995 Mark Adler
4059 * For conditions of distribution and use, see copyright notice in zlib.h
4062 /* simplify the use of the inflate_huft type with some defines */
4063 #define base more.Base
4064 #define next more.Next
4065 #define exop word.what.Exop
4066 #define bits word.what.Bits
4068 /* inflate codes private state */
4069 struct inflate_codes_state {
4072 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4073 START, /* x: set up for LEN */
4074 LEN, /* i: get length/literal/eob next */
4075 LENEXT, /* i: getting length extra (have base) */
4076 DIST, /* i: get distance next */
4077 DISTEXT, /* i: getting distance extra */
4078 COPY, /* o: copying bytes in window, waiting for space */
4079 LIT, /* o: got literal, waiting for output space */
4080 WASH, /* o: got eob, possibly still output waiting */
4081 END, /* x: got eob and all data flushed */
4082 BADCODE} /* x: got error */
4083 mode; /* current inflate_codes mode */
4085 /* mode dependent information */
4089 inflate_huft *tree; /* pointer into tree */
4090 uInt need; /* bits needed */
4091 } code; /* if LEN or DIST, where in tree */
4092 uInt lit; /* if LIT, literal */
4094 uInt get; /* bits to get for extra */
4095 uInt dist; /* distance back to copy from */
4096 } copy; /* if EXT or COPY, where and how much */
4097 } sub; /* submode */
4099 /* mode independent information */
4100 Byte lbits; /* ltree bits decoded per branch */
4101 Byte dbits; /* dtree bits decoder per branch */
4102 inflate_huft *ltree; /* literal/length/eob tree */
4103 inflate_huft *dtree; /* distance tree */
4108 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4110 inflate_huft *tl, *td;
4113 inflate_codes_statef *c;
4115 if ((c = (inflate_codes_statef *)
4116 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4119 c->lbits = (Byte)bl;
4120 c->dbits = (Byte)bd;
4123 Tracev((stderr, "inflate: codes new\n"));
4129 local int inflate_codes(s, z, r)
4130 inflate_blocks_statef *s;
4134 uInt j; /* temporary storage */
4135 inflate_huft *t; /* temporary pointer */
4136 uInt e; /* extra bits or operation */
4137 uLong b; /* bit buffer */
4138 uInt k; /* bits in bit buffer */
4139 Bytef *p; /* input data pointer */
4140 uInt n; /* bytes available there */
4141 Bytef *q; /* output window write pointer */
4142 uInt m; /* bytes to end of window or read pointer */
4143 Bytef *f; /* pointer to copy strings from */
4144 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4146 /* copy input/output information to locals (UPDATE macro restores) */
4149 /* process input and output based on current state */
4150 while (1) switch (c->mode)
4151 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4152 case START: /* x: set up for LEN */
4154 if (m >= 258 && n >= 10)
4157 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4161 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4166 c->sub.code.need = c->lbits;
4167 c->sub.code.tree = c->ltree;
4169 case LEN: /* i: get length/literal/eob next */
4170 j = c->sub.code.need;
4172 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4174 e = (uInt)(t->exop);
4175 if (e == 0) /* literal */
4177 c->sub.lit = t->base;
4178 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4179 "inflate: literal '%c'\n" :
4180 "inflate: literal 0x%02x\n", t->base));
4184 if (e & 16) /* length */
4186 c->sub.copy.get = e & 15;
4191 if ((e & 64) == 0) /* next table */
4193 c->sub.code.need = e;
4194 c->sub.code.tree = t->next;
4197 if (e & 32) /* end of block */
4199 Tracevv((stderr, "inflate: end of block\n"));
4203 c->mode = BADCODE; /* invalid code */
4204 z->msg = "invalid literal/length code";
4207 case LENEXT: /* i: getting length extra (have base) */
4208 j = c->sub.copy.get;
4210 c->len += (uInt)b & inflate_mask[j];
4212 c->sub.code.need = c->dbits;
4213 c->sub.code.tree = c->dtree;
4214 Tracevv((stderr, "inflate: length %u\n", c->len));
4216 case DIST: /* i: get distance next */
4217 j = c->sub.code.need;
4219 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4221 e = (uInt)(t->exop);
4222 if (e & 16) /* distance */
4224 c->sub.copy.get = e & 15;
4225 c->sub.copy.dist = t->base;
4229 if ((e & 64) == 0) /* next table */
4231 c->sub.code.need = e;
4232 c->sub.code.tree = t->next;
4235 c->mode = BADCODE; /* invalid code */
4236 z->msg = "invalid distance code";
4239 case DISTEXT: /* i: getting distance extra */
4240 j = c->sub.copy.get;
4242 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4244 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4246 case COPY: /* o: copying bytes in window, waiting for space */
4247 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4248 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4249 s->end - (c->sub.copy.dist - (q - s->window)) :
4250 q - c->sub.copy.dist;
4252 f = q - c->sub.copy.dist;
4253 if ((uInt)(q - s->window) < c->sub.copy.dist)
4254 f = s->end - (c->sub.copy.dist - (q - s->window));
4266 case LIT: /* o: got literal, waiting for output space */
4271 case WASH: /* o: got eob, possibly more output */
4273 if (s->read != s->write)
4279 case BADCODE: /* x: got error */
4289 local void inflate_codes_free(c, z)
4290 inflate_codes_statef *c;
4293 ZFREE(z, c, sizeof(struct inflate_codes_state));
4294 Tracev((stderr, "inflate: codes free\n"));
4298 /* inflate_util.c -- data and routines common to blocks and codes
4299 * Copyright (C) 1995 Mark Adler
4300 * For conditions of distribution and use, see copyright notice in zlib.h
4303 /* copy as much as possible from the sliding window to the output area */
4304 local int inflate_flush(s, z, r)
4305 inflate_blocks_statef *s;
4312 /* local copies of source and destination pointers */
4316 /* compute number of bytes to copy as far as end of window */
4317 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4318 if (n > z->avail_out) n = z->avail_out;
4319 if (n && r == Z_BUF_ERROR) r = Z_OK;
4321 /* update counters */
4325 /* update check information */
4326 if (s->checkfn != Z_NULL)
4327 s->check = (*s->checkfn)(s->check, q, n);
4329 /* copy as far as end of window */
4336 /* see if more to copy at beginning of window */
4341 if (s->write == s->end)
4342 s->write = s->window;
4344 /* compute bytes to copy */
4345 n = (uInt)(s->write - q);
4346 if (n > z->avail_out) n = z->avail_out;
4347 if (n && r == Z_BUF_ERROR) r = Z_OK;
4349 /* update counters */
4353 /* update check information */
4354 if (s->checkfn != Z_NULL)
4355 s->check = (*s->checkfn)(s->check, q, n);
4365 /* update pointers */
4375 /* inffast.c -- process literals and length/distance pairs fast
4376 * Copyright (C) 1995 Mark Adler
4377 * For conditions of distribution and use, see copyright notice in zlib.h
4380 /* simplify the use of the inflate_huft type with some defines */
4381 #define base more.Base
4382 #define next more.Next
4383 #define exop word.what.Exop
4384 #define bits word.what.Bits
4386 /* macros for bit input with no checking and for returning unused bytes */
4387 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4388 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4390 /* Called with number of bytes left to write in window at least 258
4391 (the maximum string length) and number of input bytes available
4392 at least ten. The ten bytes are six bytes for the longest length/
4393 distance pair plus four bytes for overloading the bit buffer. */
4395 local int inflate_fast(bl, bd, tl, td, s, z)
4397 inflate_huft *tl, *td;
4398 inflate_blocks_statef *s;
4401 inflate_huft *t; /* temporary pointer */
4402 uInt e; /* extra bits or operation */
4403 uLong b; /* bit buffer */
4404 uInt k; /* bits in bit buffer */
4405 Bytef *p; /* input data pointer */
4406 uInt n; /* bytes available there */
4407 Bytef *q; /* output window write pointer */
4408 uInt m; /* bytes to end of window or read pointer */
4409 uInt ml; /* mask for literal/length tree */
4410 uInt md; /* mask for distance tree */
4411 uInt c; /* bytes to copy */
4412 uInt d; /* distance back to copy from */
4413 Bytef *r; /* copy source pointer */
4415 /* load input, output, bit values */
4418 /* initialize masks */
4419 ml = inflate_mask[bl];
4420 md = inflate_mask[bd];
4422 /* do until not enough input or output space for fast loop */
4423 do { /* assume called with m >= 258 && n >= 10 */
4424 /* get literal/length code */
4425 GRABBITS(20) /* max bits for literal/length code */
4426 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4429 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4430 "inflate: * literal '%c'\n" :
4431 "inflate: * literal 0x%02x\n", t->base));
4432 *q++ = (Byte)t->base;
4440 /* get extra bits for length */
4442 c = t->base + ((uInt)b & inflate_mask[e]);
4444 Tracevv((stderr, "inflate: * length %u\n", c));
4446 /* decode distance base of block to copy */
4447 GRABBITS(15); /* max bits for distance code */
4448 e = (t = td + ((uInt)b & md))->exop;
4453 /* get extra bits to add to distance base */
4455 GRABBITS(e) /* get extra bits (up to 13) */
4456 d = t->base + ((uInt)b & inflate_mask[e]);
4458 Tracevv((stderr, "inflate: * distance %u\n", d));
4462 if ((uInt)(q - s->window) >= d) /* offset before dest */
4465 *q++ = *r++; c--; /* minimum count is three, */
4466 *q++ = *r++; c--; /* so unroll loop a little */
4468 else /* else offset after destination */
4470 e = d - (q - s->window); /* bytes from offset to end */
4471 r = s->end - e; /* pointer to offset */
4472 if (c > e) /* if source crosses, */
4474 c -= e; /* copy to end of window */
4478 r = s->window; /* copy rest from start of window */
4481 do { /* copy all or what's left */
4486 else if ((e & 64) == 0)
4487 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4490 z->msg = "invalid distance code";
4493 return Z_DATA_ERROR;
4500 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4503 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4504 "inflate: * literal '%c'\n" :
4505 "inflate: * literal 0x%02x\n", t->base));
4506 *q++ = (Byte)t->base;
4513 Tracevv((stderr, "inflate: * end of block\n"));
4516 return Z_STREAM_END;
4520 z->msg = "invalid literal/length code";
4523 return Z_DATA_ERROR;
4526 } while (m >= 258 && n >= 10);
4528 /* not enough input or output--restore pointers and return */
4536 /* zutil.c -- target dependent utility functions for the compression library
4537 * Copyright (C) 1995 Jean-loup Gailly.
4538 * For conditions of distribution and use, see copyright notice in zlib.h
4541 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
4543 char *zlib_version = ZLIB_VERSION;
4545 char *z_errmsg[] = {
4546 "stream end", /* Z_STREAM_END 1 */
4548 "file error", /* Z_ERRNO (-1) */
4549 "stream error", /* Z_STREAM_ERROR (-2) */
4550 "data error", /* Z_DATA_ERROR (-3) */
4551 "insufficient memory", /* Z_MEM_ERROR (-4) */
4552 "buffer error", /* Z_BUF_ERROR (-5) */
4557 /* adler32.c -- compute the Adler-32 checksum of a data stream
4558 * Copyright (C) 1995 Mark Adler
4559 * For conditions of distribution and use, see copyright notice in zlib.h
4562 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
4564 #define BASE 65521L /* largest prime smaller than 65536 */
4566 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4568 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4569 #define DO2(buf) DO1(buf); DO1(buf);
4570 #define DO4(buf) DO2(buf); DO2(buf);
4571 #define DO8(buf) DO4(buf); DO4(buf);
4572 #define DO16(buf) DO8(buf); DO8(buf);
4574 /* ========================================================================= */
4575 uLong adler32(adler, buf, len)
4580 unsigned long s1 = adler & 0xffff;
4581 unsigned long s2 = (adler >> 16) & 0xffff;
4584 if (buf == Z_NULL) return 1L;
4587 k = len < NMAX ? len : NMAX;
4599 return (s2 << 16) | s1;