2 * ==FILEVERSION 960122==
4 * This file is a conglomeration of various .h and .c files
5 * from the zlib-0.95 library source, slightly hacked.
7 * Changes that have been made include:
8 * - changed functions not used outside this file to "local"
9 * - added minCompression parameter to deflateInit2
10 * - added Z_PACKET_FLUSH (see zlib.h for details)
11 * - added inflateIncomp
16 /* zutil.h -- internal interface and configuration of the compression library
17 * Copyright (C) 1995 Jean-loup Gailly.
18 * For conditions of distribution and use, see copyright notice in zlib.h
21 /* WARNING: this file should *not* be used by applications. It is
22 part of the implementation of the compression library and is
23 subject to change. Applications should only use zlib.h.
26 /* $Id: zlib.c,v 1.1 1996/06/11 06:41:38 paulus Exp $ */
39 /* compile with -Dlocal if your debugger can't find static symbols */
43 typedef unsigned char uch;
45 typedef unsigned short ush;
47 typedef unsigned long ulg;
49 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
51 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
52 /* To be used only when the state is known to be valid */
54 /* common constants */
59 # define DEF_WBITS MAX_WBITS
61 /* default windowBits for decompression. MAX_WBITS is for compression only */
63 #if MAX_MEM_LEVEL >= 8
64 # define DEF_MEM_LEVEL 8
66 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
68 /* default memLevel */
70 #define STORED_BLOCK 0
71 #define STATIC_TREES 1
73 /* The three kinds of block type */
77 /* The minimum and maximum match lengths */
81 #if defined(KERNEL) || defined(_KERNEL)
82 # define zmemcpy(d, s, n) bcopy((s), (d), (n))
83 # define zmemzero bzero
85 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
89 # define zmemcpy memcpy
90 # define zmemzero(dest, len) memset(dest, 0, len)
92 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
93 extern void zmemzero OF((Bytef* dest, uInt len));
97 /* Diagnostic functions */
103 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
104 # define Trace(x) fprintf x
105 # define Tracev(x) {if (verbose) fprintf x ;}
106 # define Tracevv(x) {if (verbose>1) fprintf x ;}
107 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
108 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
110 # define Assert(cond,msg)
115 # define Tracecv(c,x)
119 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
121 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
122 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
124 #define ZALLOC(strm, items, size) \
125 (*((strm)->zalloc))((strm)->opaque, (items), (size))
126 #define ZFREE(strm, addr, size) \
127 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
128 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
130 /* deflate.h -- internal compression state
131 * Copyright (C) 1995 Jean-loup Gailly
132 * For conditions of distribution and use, see copyright notice in zlib.h
135 /* WARNING: this file should *not* be used by applications. It is
136 part of the implementation of the compression library and is
137 subject to change. Applications should only use zlib.h.
142 /* $Id: zlib.c,v 1.1 1996/06/11 06:41:38 paulus Exp $ */
144 /* ===========================================================================
145 * Internal compression state.
153 #define LENGTH_CODES 29
154 /* number of length codes, not counting the special END_BLOCK code */
157 /* number of literal bytes 0..255 */
159 #define L_CODES (LITERALS+1+LENGTH_CODES)
160 /* number of Literal or Length codes, including the END_BLOCK code */
163 /* number of distance codes */
166 /* number of codes used to transfer the bit lengths */
168 #define HEAP_SIZE (2*L_CODES+1)
169 /* maximum heap size */
172 /* All codes must not exceed MAX_BITS bits */
174 #define INIT_STATE 42
175 #define BUSY_STATE 113
176 #define FLUSH_STATE 124
177 #define FINISH_STATE 666
181 /* Data structure describing a single value and its code string. */
182 typedef struct ct_data_s {
184 ush freq; /* frequency count */
185 ush code; /* bit string */
188 ush dad; /* father node in Huffman tree */
189 ush len; /* length of bit string */
198 typedef struct static_tree_desc_s static_tree_desc;
200 typedef struct tree_desc_s {
201 ct_data *dyn_tree; /* the dynamic tree */
202 int max_code; /* largest code with non zero frequency */
203 static_tree_desc *stat_desc; /* the corresponding static tree */
207 typedef Pos FAR Posf;
208 typedef unsigned IPos;
210 /* A Pos is an index in the character window. We use short instead of int to
211 * save space in the various tables. IPos is used only for parameter passing.
214 typedef struct deflate_state {
215 z_stream *strm; /* pointer back to this zlib stream */
216 int status; /* as the name implies */
217 Bytef *pending_buf; /* output still pending */
218 Bytef *pending_out; /* next pending byte to output to the stream */
219 int pending; /* nb of bytes in the pending buffer */
220 uLong adler; /* adler32 of uncompressed data */
221 int noheader; /* suppress zlib header and adler32 */
222 Byte data_type; /* UNKNOWN, BINARY or ASCII */
223 Byte method; /* STORED (for zip only) or DEFLATED */
224 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */
226 /* used by deflate.c: */
228 uInt w_size; /* LZ77 window size (32K by default) */
229 uInt w_bits; /* log2(w_size) (8..16) */
230 uInt w_mask; /* w_size - 1 */
233 /* Sliding window. Input bytes are read into the second half of the window,
234 * and move to the first half later to keep a dictionary of at least wSize
235 * bytes. With this organization, matches are limited to a distance of
236 * wSize-MAX_MATCH bytes, but this ensures that IO is always
237 * performed with a length multiple of the block size. Also, it limits
238 * the window size to 64K, which is quite useful on MSDOS.
239 * To do: use the user input buffer as sliding window.
243 /* Actual size of window: 2*wSize, except when the user input buffer
244 * is directly used as sliding window.
248 /* Link to older string with same hash index. To limit the size of this
249 * array to 64K, this link is maintained only for the last 32K strings.
250 * An index in this array is thus a window index modulo 32K.
253 Posf *head; /* Heads of the hash chains or NIL. */
255 uInt ins_h; /* hash index of string to be inserted */
256 uInt hash_size; /* number of elements in hash table */
257 uInt hash_bits; /* log2(hash_size) */
258 uInt hash_mask; /* hash_size-1 */
261 /* Number of bits by which ins_h must be shifted at each input
262 * step. It must be such that after MIN_MATCH steps, the oldest
263 * byte no longer takes part in the hash key, that is:
264 * hash_shift * MIN_MATCH >= hash_bits
268 /* Window position at the beginning of the current output block. Gets
269 * negative when the window is moved backwards.
272 uInt match_length; /* length of best match */
273 IPos prev_match; /* previous match */
274 int match_available; /* set if previous match exists */
275 uInt strstart; /* start of string to insert */
276 uInt match_start; /* start of matching string */
277 uInt lookahead; /* number of valid bytes ahead in window */
280 /* Length of the best match at previous step. Matches not greater than this
281 * are discarded. This is used in the lazy match evaluation.
284 uInt max_chain_length;
285 /* To speed up deflation, hash chains are never searched beyond this
286 * length. A higher limit improves compression ratio but degrades the
291 /* Attempt to find a better match only when the current match is strictly
292 * smaller than this value. This mechanism is used only for compression
295 # define max_insert_length max_lazy_match
296 /* Insert new strings in the hash table only if the match length is not
297 * greater than this length. This saves time but degrades compression.
298 * max_insert_length is used only for compression levels <= 3.
301 int level; /* compression level (1..9) */
302 int strategy; /* favor or force Huffman coding*/
305 /* Use a faster search when the previous match is longer than this */
307 int nice_match; /* Stop searching when current match exceeds this */
309 /* used by trees.c: */
310 /* Didn't use ct_data typedef below to supress compiler warning */
311 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
312 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
313 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
315 struct tree_desc_s l_desc; /* desc. for literal tree */
316 struct tree_desc_s d_desc; /* desc. for distance tree */
317 struct tree_desc_s bl_desc; /* desc. for bit length tree */
319 ush bl_count[MAX_BITS+1];
320 /* number of codes at each bit length for an optimal tree */
322 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
323 int heap_len; /* number of elements in the heap */
324 int heap_max; /* element of largest frequency */
325 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
326 * The same heap array is used to build all trees.
329 uch depth[2*L_CODES+1];
330 /* Depth of each subtree used as tie breaker for trees of equal frequency
333 uchf *l_buf; /* buffer for literals or lengths */
336 /* Size of match buffer for literals/lengths. There are 4 reasons for
337 * limiting lit_bufsize to 64K:
338 * - frequencies can be kept in 16 bit counters
339 * - if compression is not successful for the first block, all input
340 * data is still in the window so we can still emit a stored block even
341 * when input comes from standard input. (This can also be done for
342 * all blocks if lit_bufsize is not greater than 32K.)
343 * - if compression is not successful for a file smaller than 64K, we can
344 * even emit a stored file instead of a stored block (saving 5 bytes).
345 * This is applicable only for zip (not gzip or zlib).
346 * - creating new Huffman trees less frequently may not provide fast
347 * adaptation to changes in the input data statistics. (Take for
348 * example a binary file with poorly compressible code followed by
349 * a highly compressible string table.) Smaller buffer sizes give
350 * fast adaptation but have of course the overhead of transmitting
351 * trees more frequently.
352 * - I can't count above 4
355 uInt last_lit; /* running index in l_buf */
358 /* Buffer for distances. To simplify the code, d_buf and l_buf have
359 * the same number of elements. To use different lengths, an extra flag
360 * array would be necessary.
363 ulg opt_len; /* bit length of current block with optimal trees */
364 ulg static_len; /* bit length of current block with static trees */
365 ulg compressed_len; /* total bit length of compressed file */
366 uInt matches; /* number of string matches in current block */
367 int last_eob_len; /* bit length of EOB code for last block */
370 ulg bits_sent; /* bit length of the compressed data */
374 /* Output buffer. bits are inserted starting at the bottom (least
378 /* Number of valid bits in bi_buf. All bits above the last valid bit
382 uInt blocks_in_packet;
383 /* Number of blocks produced since the last time Z_PACKET_FLUSH
389 /* Output a byte on the stream.
390 * IN assertion: there is enough room in pending_buf.
392 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
395 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
396 /* Minimum amount of lookahead, except at the end of the input file.
397 * See deflate.c for comments about the MIN_MATCH+1.
400 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
401 /* In order to simplify the code, particularly on 16 bit machines, match
402 * distances are limited to MAX_DIST instead of WSIZE.
406 local void ct_init OF((deflate_state *s));
407 local int ct_tally OF((deflate_state *s, int dist, int lc));
408 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
410 local void ct_align OF((deflate_state *s));
411 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
413 local void ct_stored_type_only OF((deflate_state *s));
417 /* deflate.c -- compress data using the deflation algorithm
418 * Copyright (C) 1995 Jean-loup Gailly.
419 * For conditions of distribution and use, see copyright notice in zlib.h
425 * The "deflation" process depends on being able to identify portions
426 * of the input text which are identical to earlier input (within a
427 * sliding window trailing behind the input currently being processed).
429 * The most straightforward technique turns out to be the fastest for
430 * most input files: try all possible matches and select the longest.
431 * The key feature of this algorithm is that insertions into the string
432 * dictionary are very simple and thus fast, and deletions are avoided
433 * completely. Insertions are performed at each input character, whereas
434 * string matches are performed only when the previous match ends. So it
435 * is preferable to spend more time in matches to allow very fast string
436 * insertions and avoid deletions. The matching algorithm for small
437 * strings is inspired from that of Rabin & Karp. A brute force approach
438 * is used to find longer strings when a small match has been found.
439 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
440 * (by Leonid Broukhis).
441 * A previous version of this file used a more sophisticated algorithm
442 * (by Fiala and Greene) which is guaranteed to run in linear amortized
443 * time, but has a larger average cost, uses more memory and is patented.
444 * However the F&G algorithm may be faster for some highly redundant
445 * files if the parameter max_chain_length (described below) is too large.
449 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
450 * I found it in 'freeze' written by Leonid Broukhis.
451 * Thanks to many people for bug reports and testing.
455 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
456 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
458 * A description of the Rabin and Karp algorithm is given in the book
459 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
461 * Fiala,E.R., and Greene,D.H.
462 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
466 /* $Id: zlib.c,v 1.1 1996/06/11 06:41:38 paulus Exp $ */
468 local char copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
470 If you use the zlib library in a product, an acknowledgment is welcome
471 in the documentation of your product. If for some reason you cannot
472 include such an acknowledgment, I would appreciate that you keep this
473 copyright string in the executable of your product.
477 /* Tail of hash chains */
480 # define TOO_FAR 4096
482 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
484 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
485 /* Minimum amount of lookahead, except at the end of the input file.
486 * See deflate.c for comments about the MIN_MATCH+1.
489 /* Values for max_lazy_match, good_match and max_chain_length, depending on
490 * the desired pack level (0..9). The values given below have been tuned to
491 * exclude worst case performance for pathological files. Better values may be
492 * found for specific files.
495 typedef struct config_s {
496 ush good_length; /* reduce lazy search above this match length */
497 ush max_lazy; /* do not perform lazy search above this match length */
498 ush nice_length; /* quit search above this match length */
502 local config configuration_table[10] = {
503 /* good lazy nice chain */
504 /* 0 */ {0, 0, 0, 0}, /* store only */
505 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
506 /* 2 */ {4, 5, 16, 8},
507 /* 3 */ {4, 6, 32, 32},
509 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
510 /* 5 */ {8, 16, 32, 32},
511 /* 6 */ {8, 16, 128, 128},
512 /* 7 */ {8, 32, 128, 256},
513 /* 8 */ {32, 128, 258, 1024},
514 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
516 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
517 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
522 /* result of memcmp for equal strings */
524 /* ===========================================================================
525 * Prototypes for local functions.
528 local void fill_window OF((deflate_state *s));
529 local int deflate_fast OF((deflate_state *s, int flush));
530 local int deflate_slow OF((deflate_state *s, int flush));
531 local void lm_init OF((deflate_state *s));
532 local int longest_match OF((deflate_state *s, IPos cur_match));
533 local void putShortMSB OF((deflate_state *s, uInt b));
534 local void flush_pending OF((z_stream *strm));
535 local int read_buf OF((z_stream *strm, charf *buf, unsigned size));
537 void match_init OF((void)); /* asm code initialization */
541 local void check_match OF((deflate_state *s, IPos start, IPos match,
546 /* ===========================================================================
547 * Update a hash value with the given input byte
548 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
549 * input characters, so that a running hash key can be computed from the
550 * previous key instead of complete recalculation each time.
552 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
555 /* ===========================================================================
556 * Insert string str in the dictionary and set match_head to the previous head
557 * of the hash chain (the most recent string with same hash key). Return
558 * the previous length of the hash chain.
559 * IN assertion: all calls to to INSERT_STRING are made with consecutive
560 * input characters and the first MIN_MATCH bytes of str are valid
561 * (except for the last MIN_MATCH-1 bytes of the input file).
563 #define INSERT_STRING(s, str, match_head) \
564 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
565 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
566 s->head[s->ins_h] = (str))
568 /* ===========================================================================
569 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
570 * prev[] will be initialized on the fly.
572 #define CLEAR_HASH(s) \
573 s->head[s->hash_size-1] = NIL; \
574 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
576 /* ========================================================================= */
577 int deflateInit (strm, level)
581 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
583 /* To do: ignore strm->next_in if we use it as window */
586 /* ========================================================================= */
587 int deflateInit2 (strm, level, method, windowBits, memLevel,
588 strategy, minCompression)
600 if (strm == Z_NULL) return Z_STREAM_ERROR;
603 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
604 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
606 if (level == Z_DEFAULT_COMPRESSION) level = 6;
608 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
610 windowBits = -windowBits;
612 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
613 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
614 return Z_STREAM_ERROR;
616 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
617 if (s == Z_NULL) return Z_MEM_ERROR;
618 strm->state = (struct internal_state FAR *)s;
621 s->noheader = noheader;
622 s->w_bits = windowBits;
623 s->w_size = 1 << s->w_bits;
624 s->w_mask = s->w_size - 1;
626 s->hash_bits = memLevel + 7;
627 s->hash_size = 1 << s->hash_bits;
628 s->hash_mask = s->hash_size - 1;
629 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
631 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
632 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
633 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
635 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
637 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
639 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
640 s->pending_buf == Z_NULL) {
641 strm->msg = z_errmsg[1-Z_MEM_ERROR];
645 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
646 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
647 /* We overlay pending_buf and d_buf+l_buf. This works since the average
648 * output size for (length,distance) codes is <= 32 bits (worst case
653 s->strategy = strategy;
654 s->method = (Byte)method;
655 s->minCompr = minCompression;
656 s->blocks_in_packet = 0;
658 return deflateReset(strm);
661 /* ========================================================================= */
662 int deflateReset (strm)
667 if (strm == Z_NULL || strm->state == Z_NULL ||
668 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
670 strm->total_in = strm->total_out = 0;
671 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
672 strm->data_type = Z_UNKNOWN;
674 s = (deflate_state *)strm->state;
676 s->pending_out = s->pending_buf;
678 if (s->noheader < 0) {
679 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
681 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
690 /* =========================================================================
691 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
692 * IN assertion: the stream state is correct and there is enough room in
695 local void putShortMSB (s, b)
699 put_byte(s, (Byte)(b >> 8));
700 put_byte(s, (Byte)(b & 0xff));
703 /* =========================================================================
704 * Flush as much pending output as possible.
706 local void flush_pending(strm)
709 deflate_state *state = (deflate_state *) strm->state;
710 unsigned len = state->pending;
712 if (len > strm->avail_out) len = strm->avail_out;
713 if (len == 0) return;
715 if (strm->next_out != NULL) {
716 zmemcpy(strm->next_out, state->pending_out, len);
717 strm->next_out += len;
719 state->pending_out += len;
720 strm->total_out += len;
721 strm->avail_out -= len;
722 state->pending -= len;
723 if (state->pending == 0) {
724 state->pending_out = state->pending_buf;
728 /* ========================================================================= */
729 int deflate (strm, flush)
733 deflate_state *state = (deflate_state *) strm->state;
735 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
737 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
738 ERR_RETURN(strm, Z_STREAM_ERROR);
740 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
742 state->strm = strm; /* just in case */
744 /* Write the zlib header */
745 if (state->status == INIT_STATE) {
747 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
748 uInt level_flags = (state->level-1) >> 1;
750 if (level_flags > 3) level_flags = 3;
751 header |= (level_flags << 6);
752 header += 31 - (header % 31);
754 state->status = BUSY_STATE;
755 putShortMSB(state, header);
758 /* Flush as much pending output as possible */
759 if (state->pending != 0) {
761 if (strm->avail_out == 0) return Z_OK;
764 /* If we came back in here to get the last output from
765 * a previous flush, we're done for now.
767 if (state->status == FLUSH_STATE) {
768 state->status = BUSY_STATE;
769 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
773 /* User must not provide more input after the first FINISH: */
774 if (state->status == FINISH_STATE && strm->avail_in != 0) {
775 ERR_RETURN(strm, Z_BUF_ERROR);
778 /* Start a new block or continue the current one.
780 if (strm->avail_in != 0 || state->lookahead != 0 ||
781 (flush == Z_FINISH && state->status != FINISH_STATE)) {
784 if (flush == Z_FINISH) {
785 state->status = FINISH_STATE;
787 if (state->level <= 3) {
788 quit = deflate_fast(state, flush);
790 quit = deflate_slow(state, flush);
792 if (quit || strm->avail_out == 0)
794 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
795 * of deflate should use the same flush parameter to make sure
796 * that the flush is complete. So we don't have to output an
797 * empty block here, this will be done at next call. This also
798 * ensures that for a very small output buffer, we emit at most
803 /* If a flush was requested, we have a little more to output now. */
804 if (flush != Z_NO_FLUSH && flush != Z_FINISH
805 && state->status != FINISH_STATE) {
807 case Z_PARTIAL_FLUSH:
811 /* Output just the 3-bit `stored' block type value,
812 but not a zero length. */
813 ct_stored_type_only(state);
816 ct_stored_block(state, (char*)0, 0L, 0);
817 /* For a full flush, this empty block will be recognized
818 * as a special marker by inflate_sync().
820 if (flush == Z_FULL_FLUSH) {
821 CLEAR_HASH(state); /* forget history */
825 if (strm->avail_out == 0) {
826 /* We'll have to come back to get the rest of the output;
827 * this ensures we don't output a second zero-length stored
828 * block (or whatever).
830 state->status = FLUSH_STATE;
835 Assert(strm->avail_out > 0, "bug2");
837 if (flush != Z_FINISH) return Z_OK;
838 if (state->noheader) return Z_STREAM_END;
840 /* Write the zlib trailer (adler32) */
841 putShortMSB(state, (uInt)(state->adler >> 16));
842 putShortMSB(state, (uInt)(state->adler & 0xffff));
844 /* If avail_out is zero, the application will call deflate again
847 state->noheader = -1; /* write the trailer only once! */
848 return state->pending != 0 ? Z_OK : Z_STREAM_END;
851 /* ========================================================================= */
852 int deflateEnd (strm)
855 deflate_state *state = (deflate_state *) strm->state;
857 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
859 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
860 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
861 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
862 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
864 ZFREE(strm, state, sizeof(deflate_state));
865 strm->state = Z_NULL;
870 /* ===========================================================================
871 * Read a new buffer from the current input stream, update the adler32
872 * and total number of bytes read.
874 local int read_buf(strm, buf, size)
879 unsigned len = strm->avail_in;
880 deflate_state *state = (deflate_state *) strm->state;
882 if (len > size) len = size;
883 if (len == 0) return 0;
885 strm->avail_in -= len;
887 if (!state->noheader) {
888 state->adler = adler32(state->adler, strm->next_in, len);
890 zmemcpy(buf, strm->next_in, len);
891 strm->next_in += len;
892 strm->total_in += len;
897 /* ===========================================================================
898 * Initialize the "longest match" routines for a new zlib stream
900 local void lm_init (s)
903 s->window_size = (ulg)2L*s->w_size;
907 /* Set the default configuration parameters:
909 s->max_lazy_match = configuration_table[s->level].max_lazy;
910 s->good_match = configuration_table[s->level].good_length;
911 s->nice_match = configuration_table[s->level].nice_length;
912 s->max_chain_length = configuration_table[s->level].max_chain;
917 s->match_length = MIN_MATCH-1;
918 s->match_available = 0;
921 match_init(); /* initialize the asm code */
925 /* ===========================================================================
926 * Set match_start to the longest match starting at the given string and
927 * return its length. Matches shorter or equal to prev_length are discarded,
928 * in which case the result is equal to prev_length and match_start is
930 * IN assertions: cur_match is the head of the hash chain for the current
931 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
934 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
935 * match.S. The code will be functionally equivalent.
937 local int longest_match(s, cur_match)
939 IPos cur_match; /* current match */
941 unsigned chain_length = s->max_chain_length;/* max hash chain length */
942 register Bytef *scan = s->window + s->strstart; /* current string */
943 register Bytef *match; /* matched string */
944 register int len; /* length of current match */
945 int best_len = s->prev_length; /* best match length so far */
946 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
947 s->strstart - (IPos)MAX_DIST(s) : NIL;
948 /* Stop when cur_match becomes <= limit. To simplify the code,
949 * we prevent matches with the string of window index 0.
951 Posf *prev = s->prev;
952 uInt wmask = s->w_mask;
955 /* Compare two bytes at a time. Note: this is not always beneficial.
956 * Try with and without -DUNALIGNED_OK to check.
958 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
959 register ush scan_start = *(ushf*)scan;
960 register ush scan_end = *(ushf*)(scan+best_len-1);
962 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
963 register Byte scan_end1 = scan[best_len-1];
964 register Byte scan_end = scan[best_len];
967 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
968 * It is easy to get rid of this optimization if necessary.
970 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
972 /* Do not waste too much time if we already have a good match: */
973 if (s->prev_length >= s->good_match) {
976 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
979 Assert(cur_match < s->strstart, "no future");
980 match = s->window + cur_match;
982 /* Skip to next match if the match length cannot increase
983 * or if the match length is less than 2:
985 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
986 /* This code assumes sizeof(unsigned short) == 2. Do not use
987 * UNALIGNED_OK if your compiler uses a different size.
989 if (*(ushf*)(match+best_len-1) != scan_end ||
990 *(ushf*)match != scan_start) continue;
992 /* It is not necessary to compare scan[2] and match[2] since they are
993 * always equal when the other bytes match, given that the hash keys
994 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
995 * strstart+3, +5, ... up to strstart+257. We check for insufficient
996 * lookahead only every 4th comparison; the 128th check will be made
997 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
998 * necessary to put more guard bytes at the end of the window, or
999 * to check more often for insufficient lookahead.
1001 Assert(scan[2] == match[2], "scan[2]?");
1004 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1005 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1006 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1007 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1009 /* The funny "do {}" generates better code on most compilers */
1011 /* Here, scan <= window+strstart+257 */
1012 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1013 if (*scan == *match) scan++;
1015 len = (MAX_MATCH - 1) - (int)(strend-scan);
1016 scan = strend - (MAX_MATCH-1);
1018 #else /* UNALIGNED_OK */
1020 if (match[best_len] != scan_end ||
1021 match[best_len-1] != scan_end1 ||
1023 *++match != scan[1]) continue;
1025 /* The check at best_len-1 can be removed because it will be made
1026 * again later. (This heuristic is not always a win.)
1027 * It is not necessary to compare scan[2] and match[2] since they
1028 * are always equal when the other bytes match, given that
1029 * the hash keys are equal and that HASH_BITS >= 8.
1032 Assert(*scan == *match, "match[2]?");
1034 /* We check for insufficient lookahead only every 8th comparison;
1035 * the 256th check will be made at strstart+258.
1038 } while (*++scan == *++match && *++scan == *++match &&
1039 *++scan == *++match && *++scan == *++match &&
1040 *++scan == *++match && *++scan == *++match &&
1041 *++scan == *++match && *++scan == *++match &&
1044 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1046 len = MAX_MATCH - (int)(strend - scan);
1047 scan = strend - MAX_MATCH;
1049 #endif /* UNALIGNED_OK */
1051 if (len > best_len) {
1052 s->match_start = cur_match;
1054 if (len >= s->nice_match) break;
1056 scan_end = *(ushf*)(scan+best_len-1);
1058 scan_end1 = scan[best_len-1];
1059 scan_end = scan[best_len];
1062 } while ((cur_match = prev[cur_match & wmask]) > limit
1063 && --chain_length != 0);
1070 /* ===========================================================================
1071 * Check that the match at match_start is indeed a match.
1073 local void check_match(s, start, match, length)
1078 /* check that the match is indeed a match */
1079 if (memcmp((charf *)s->window + match,
1080 (charf *)s->window + start, length) != EQUAL) {
1082 " start %u, match %u, length %d\n",
1083 start, match, length);
1084 do { fprintf(stderr, "%c%c", s->window[match++],
1085 s->window[start++]); } while (--length != 0);
1086 z_error("invalid match");
1089 fprintf(stderr,"\\[%d,%d]", start-match, length);
1090 do { putc(s->window[start++], stderr); } while (--length != 0);
1094 # define check_match(s, start, match, length)
1097 /* ===========================================================================
1098 * Fill the window when the lookahead becomes insufficient.
1099 * Updates strstart and lookahead.
1101 * IN assertion: lookahead < MIN_LOOKAHEAD
1102 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1103 * At least one byte has been read, or avail_in == 0; reads are
1104 * performed for at least two bytes (required for the zip translate_eol
1105 * option -- not supported here).
1107 local void fill_window(s)
1110 register unsigned n, m;
1112 unsigned more; /* Amount of free space at the end of the window. */
1113 uInt wsize = s->w_size;
1116 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1118 /* Deal with !@#$% 64K limit: */
1119 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1121 } else if (more == (unsigned)(-1)) {
1122 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1123 * and lookahead == 1 (input done one byte at time)
1127 /* If the window is almost full and there is insufficient lookahead,
1128 * move the upper half to the lower one to make room in the upper half.
1130 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1132 /* By the IN assertion, the window is not empty so we can't confuse
1133 * more == 0 with more == 64K on a 16 bit machine.
1135 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1137 s->match_start -= wsize;
1138 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1140 s->block_start -= (long) wsize;
1142 /* Slide the hash table (could be avoided with 32 bit values
1143 at the expense of memory usage):
1149 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1156 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1157 /* If n is not on any hash chain, prev[n] is garbage but
1158 * its value will never be used.
1164 if (s->strm->avail_in == 0) return;
1166 /* If there was no sliding:
1167 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1168 * more == window_size - lookahead - strstart
1169 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1170 * => more >= window_size - 2*WSIZE + 2
1171 * In the BIG_MEM or MMAP case (not yet supported),
1172 * window_size == input_size + MIN_LOOKAHEAD &&
1173 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1174 * Otherwise, window_size == 2*WSIZE so more >= 2.
1175 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1177 Assert(more >= 2, "more < 2");
1179 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1183 /* Initialize the hash value now that we have some input: */
1184 if (s->lookahead >= MIN_MATCH) {
1185 s->ins_h = s->window[s->strstart];
1186 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1188 Call UPDATE_HASH() MIN_MATCH-3 more times
1191 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1192 * but this is not important since only literal bytes will be emitted.
1195 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1198 /* ===========================================================================
1199 * Flush the current block, with given end-of-file flag.
1200 * IN assertion: strstart is set to the end of the current match.
1202 #define FLUSH_BLOCK_ONLY(s, flush) { \
1203 ct_flush_block(s, (s->block_start >= 0L ? \
1204 (charf *)&s->window[(unsigned)s->block_start] : \
1205 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1206 s->block_start = s->strstart; \
1207 flush_pending(s->strm); \
1208 Tracev((stderr,"[FLUSH]")); \
1211 /* Same but force premature exit if necessary. */
1212 #define FLUSH_BLOCK(s, flush) { \
1213 FLUSH_BLOCK_ONLY(s, flush); \
1214 if (s->strm->avail_out == 0) return 1; \
1217 /* ===========================================================================
1218 * Compress as much as possible from the input stream, return true if
1219 * processing was terminated prematurely (no more input or output space).
1220 * This function does not perform lazy evaluationof matches and inserts
1221 * new strings in the dictionary only for unmatched strings or for short
1222 * matches. It is used only for the fast compression options.
1224 local int deflate_fast(s, flush)
1228 IPos hash_head; /* head of the hash chain */
1229 int bflush; /* set if current block must be flushed */
1231 s->prev_length = MIN_MATCH-1;
1234 /* Make sure that we always have enough lookahead, except
1235 * at the end of the input file. We need MAX_MATCH bytes
1236 * for the next match, plus MIN_MATCH bytes to insert the
1237 * string following the next match.
1239 if (s->lookahead < MIN_LOOKAHEAD) {
1241 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1243 if (s->lookahead == 0) break; /* flush the current block */
1246 /* Insert the string window[strstart .. strstart+2] in the
1247 * dictionary, and set hash_head to the head of the hash chain:
1249 if (s->lookahead >= MIN_MATCH) {
1250 INSERT_STRING(s, s->strstart, hash_head);
1253 /* Find the longest match, discarding those <= prev_length.
1254 * At this point we have always match_length < MIN_MATCH
1256 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1257 /* To simplify the code, we prevent matches with the string
1258 * of window index 0 (in particular we have to avoid a match
1259 * of the string with itself at the start of the input file).
1261 if (s->strategy != Z_HUFFMAN_ONLY) {
1262 s->match_length = longest_match (s, hash_head);
1264 /* longest_match() sets match_start */
1266 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1268 if (s->match_length >= MIN_MATCH) {
1269 check_match(s, s->strstart, s->match_start, s->match_length);
1271 bflush = ct_tally(s, s->strstart - s->match_start,
1272 s->match_length - MIN_MATCH);
1274 s->lookahead -= s->match_length;
1276 /* Insert new strings in the hash table only if the match length
1277 * is not too large. This saves time but degrades compression.
1279 if (s->match_length <= s->max_insert_length &&
1280 s->lookahead >= MIN_MATCH) {
1281 s->match_length--; /* string at strstart already in hash table */
1284 INSERT_STRING(s, s->strstart, hash_head);
1285 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1286 * always MIN_MATCH bytes ahead.
1288 } while (--s->match_length != 0);
1291 s->strstart += s->match_length;
1292 s->match_length = 0;
1293 s->ins_h = s->window[s->strstart];
1294 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1296 Call UPDATE_HASH() MIN_MATCH-3 more times
1298 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1299 * matter since it will be recomputed at next deflate call.
1303 /* No match, output a literal byte */
1304 Tracevv((stderr,"%c", s->window[s->strstart]));
1305 bflush = ct_tally (s, 0, s->window[s->strstart]);
1309 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1311 FLUSH_BLOCK(s, flush);
1312 return 0; /* normal exit */
1315 /* ===========================================================================
1316 * Same as above, but achieves better compression. We use a lazy
1317 * evaluation for matches: a match is finally adopted only if there is
1318 * no better match at the next window position.
1320 local int deflate_slow(s, flush)
1324 IPos hash_head; /* head of hash chain */
1325 int bflush; /* set if current block must be flushed */
1327 /* Process the input block. */
1329 /* Make sure that we always have enough lookahead, except
1330 * at the end of the input file. We need MAX_MATCH bytes
1331 * for the next match, plus MIN_MATCH bytes to insert the
1332 * string following the next match.
1334 if (s->lookahead < MIN_LOOKAHEAD) {
1336 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1338 if (s->lookahead == 0) break; /* flush the current block */
1341 /* Insert the string window[strstart .. strstart+2] in the
1342 * dictionary, and set hash_head to the head of the hash chain:
1344 if (s->lookahead >= MIN_MATCH) {
1345 INSERT_STRING(s, s->strstart, hash_head);
1348 /* Find the longest match, discarding those <= prev_length.
1350 s->prev_length = s->match_length, s->prev_match = s->match_start;
1351 s->match_length = MIN_MATCH-1;
1353 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1354 s->strstart - hash_head <= MAX_DIST(s)) {
1355 /* To simplify the code, we prevent matches with the string
1356 * of window index 0 (in particular we have to avoid a match
1357 * of the string with itself at the start of the input file).
1359 if (s->strategy != Z_HUFFMAN_ONLY) {
1360 s->match_length = longest_match (s, hash_head);
1362 /* longest_match() sets match_start */
1363 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1365 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1366 (s->match_length == MIN_MATCH &&
1367 s->strstart - s->match_start > TOO_FAR))) {
1369 /* If prev_match is also MIN_MATCH, match_start is garbage
1370 * but we will ignore the current match anyway.
1372 s->match_length = MIN_MATCH-1;
1375 /* If there was a match at the previous step and the current
1376 * match is not better, output the previous match:
1378 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1379 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1380 /* Do not insert strings in hash table beyond this. */
1382 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1384 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1385 s->prev_length - MIN_MATCH);
1387 /* Insert in hash table all strings up to the end of the match.
1388 * strstart-1 and strstart are already inserted. If there is not
1389 * enough lookahead, the last two strings are not inserted in
1392 s->lookahead -= s->prev_length-1;
1393 s->prev_length -= 2;
1395 if (++s->strstart <= max_insert) {
1396 INSERT_STRING(s, s->strstart, hash_head);
1398 } while (--s->prev_length != 0);
1399 s->match_available = 0;
1400 s->match_length = MIN_MATCH-1;
1403 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1405 } else if (s->match_available) {
1406 /* If there was no match at the previous position, output a
1407 * single literal. If there was a match but the current match
1408 * is longer, truncate the previous match to a single literal.
1410 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1411 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1412 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1416 if (s->strm->avail_out == 0) return 1;
1418 /* There is no previous match to compare with, wait for
1419 * the next step to decide.
1421 s->match_available = 1;
1426 Assert (flush != Z_NO_FLUSH, "no flush?");
1427 if (s->match_available) {
1428 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1429 ct_tally (s, 0, s->window[s->strstart-1]);
1430 s->match_available = 0;
1432 FLUSH_BLOCK(s, flush);
1438 /* trees.c -- output deflated data using Huffman coding
1439 * Copyright (C) 1995 Jean-loup Gailly
1440 * For conditions of distribution and use, see copyright notice in zlib.h
1446 * The "deflation" process uses several Huffman trees. The more
1447 * common source values are represented by shorter bit sequences.
1449 * Each code tree is stored in a compressed form which is itself
1450 * a Huffman encoding of the lengths of all the code strings (in
1451 * ascending order by source values). The actual code strings are
1452 * reconstructed from the lengths in the inflate process, as described
1453 * in the deflate specification.
1457 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1458 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1461 * Data Compression: Methods and Theory, pp. 49-50.
1462 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1466 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1469 /* $Id: zlib.c,v 1.1 1996/06/11 06:41:38 paulus Exp $ */
1475 /* ===========================================================================
1479 #define MAX_BL_BITS 7
1480 /* Bit length codes must not exceed MAX_BL_BITS bits */
1482 #define END_BLOCK 256
1483 /* end of block literal code */
1486 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1488 #define REPZ_3_10 17
1489 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1491 #define REPZ_11_138 18
1492 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1494 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1495 = {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};
1497 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1498 = {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};
1500 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1501 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1503 local uch bl_order[BL_CODES]
1504 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1505 /* The lengths of the bit length codes are sent in order of decreasing
1506 * probability, to avoid transmitting the lengths for unused bit length codes.
1509 #define Buf_size (8 * 2*sizeof(char))
1510 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1511 * more than 16 bits on some systems.)
1514 /* ===========================================================================
1515 * Local data. These are initialized only once.
1516 * To do: initialize at compile time to be completely reentrant. ???
1519 local ct_data static_ltree[L_CODES+2];
1520 /* The static literal tree. Since the bit lengths are imposed, there is no
1521 * need for the L_CODES extra codes used during heap construction. However
1522 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1526 local ct_data static_dtree[D_CODES];
1527 /* The static distance tree. (Actually a trivial tree since all codes use
1531 local uch dist_code[512];
1532 /* distance codes. The first 256 values correspond to the distances
1533 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1534 * the 15 bit distances.
1537 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1538 /* length code for each normalized match length (0 == MIN_MATCH) */
1540 local int base_length[LENGTH_CODES];
1541 /* First normalized length for each code (0 = MIN_MATCH) */
1543 local int base_dist[D_CODES];
1544 /* First normalized distance for each code (0 = distance of 1) */
1546 struct static_tree_desc_s {
1547 ct_data *static_tree; /* static tree or NULL */
1548 intf *extra_bits; /* extra bits for each code or NULL */
1549 int extra_base; /* base index for extra_bits */
1550 int elems; /* max number of elements in the tree */
1551 int max_length; /* max bit length for the codes */
1554 local static_tree_desc static_l_desc =
1555 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1557 local static_tree_desc static_d_desc =
1558 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1560 local static_tree_desc static_bl_desc =
1561 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1563 /* ===========================================================================
1564 * Local (static) routines in this file.
1567 local void ct_static_init OF((void));
1568 local void init_block OF((deflate_state *s));
1569 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1570 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1571 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1572 local void build_tree OF((deflate_state *s, tree_desc *desc));
1573 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1574 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1575 local int build_bl_tree OF((deflate_state *s));
1576 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1578 local void compress_block OF((deflate_state *s, ct_data *ltree,
1580 local void set_data_type OF((deflate_state *s));
1581 local unsigned bi_reverse OF((unsigned value, int length));
1582 local void bi_windup OF((deflate_state *s));
1583 local void bi_flush OF((deflate_state *s));
1584 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1588 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1589 /* Send a code of the given tree. c and tree must not have side effects */
1591 #else /* DEBUG_ZLIB */
1592 # define send_code(s, c, tree) \
1593 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1594 send_bits(s, tree[c].Code, tree[c].Len); }
1597 #define d_code(dist) \
1598 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1599 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1600 * must not have side effects. dist_code[256] and dist_code[257] are never
1604 /* ===========================================================================
1605 * Output a short LSB first on the stream.
1606 * IN assertion: there is enough room in pendingBuf.
1608 #define put_short(s, w) { \
1609 put_byte(s, (uch)((w) & 0xff)); \
1610 put_byte(s, (uch)((ush)(w) >> 8)); \
1613 /* ===========================================================================
1614 * Send a value on a given number of bits.
1615 * IN assertion: length <= 16 and value fits in length bits.
1618 local void send_bits OF((deflate_state *s, int value, int length));
1620 local void send_bits(s, value, length)
1622 int value; /* value to send */
1623 int length; /* number of bits */
1625 Tracev((stderr," l %2d v %4x ", length, value));
1626 Assert(length > 0 && length <= 15, "invalid length");
1627 s->bits_sent += (ulg)length;
1629 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1630 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1631 * unused bits in value.
1633 if (s->bi_valid > (int)Buf_size - length) {
1634 s->bi_buf |= (value << s->bi_valid);
1635 put_short(s, s->bi_buf);
1636 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1637 s->bi_valid += length - Buf_size;
1639 s->bi_buf |= value << s->bi_valid;
1640 s->bi_valid += length;
1643 #else /* !DEBUG_ZLIB */
1645 #define send_bits(s, value, length) \
1646 { int len = length;\
1647 if (s->bi_valid > (int)Buf_size - len) {\
1649 s->bi_buf |= (val << s->bi_valid);\
1650 put_short(s, s->bi_buf);\
1651 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1652 s->bi_valid += len - Buf_size;\
1654 s->bi_buf |= (value) << s->bi_valid;\
1655 s->bi_valid += len;\
1658 #endif /* DEBUG_ZLIB */
1661 #define MAX(a,b) (a >= b ? a : b)
1662 /* the arguments must not have side effects */
1664 /* ===========================================================================
1665 * Initialize the various 'constant' tables.
1666 * To do: do this at compile time.
1668 local void ct_static_init()
1670 int n; /* iterates over tree elements */
1671 int bits; /* bit counter */
1672 int length; /* length value */
1673 int code; /* code value */
1674 int dist; /* distance index */
1675 ush bl_count[MAX_BITS+1];
1676 /* number of codes at each bit length for an optimal tree */
1678 /* Initialize the mapping length (0..255) -> length code (0..28) */
1680 for (code = 0; code < LENGTH_CODES-1; code++) {
1681 base_length[code] = length;
1682 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1683 length_code[length++] = (uch)code;
1686 Assert (length == 256, "ct_static_init: length != 256");
1687 /* Note that the length 255 (match length 258) can be represented
1688 * in two different ways: code 284 + 5 bits or code 285, so we
1689 * overwrite length_code[255] to use the best encoding:
1691 length_code[length-1] = (uch)code;
1693 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1695 for (code = 0 ; code < 16; code++) {
1696 base_dist[code] = dist;
1697 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1698 dist_code[dist++] = (uch)code;
1701 Assert (dist == 256, "ct_static_init: dist != 256");
1702 dist >>= 7; /* from now on, all distances are divided by 128 */
1703 for ( ; code < D_CODES; code++) {
1704 base_dist[code] = dist << 7;
1705 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1706 dist_code[256 + dist++] = (uch)code;
1709 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1711 /* Construct the codes of the static literal tree */
1712 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1714 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1715 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1716 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1717 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1718 /* Codes 286 and 287 do not exist, but we must include them in the
1719 * tree construction to get a canonical Huffman tree (longest code
1722 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1724 /* The static distance tree is trivial: */
1725 for (n = 0; n < D_CODES; n++) {
1726 static_dtree[n].Len = 5;
1727 static_dtree[n].Code = bi_reverse(n, 5);
1731 /* ===========================================================================
1732 * Initialize the tree data structures for a new zlib stream.
1734 local void ct_init(s)
1737 if (static_dtree[0].Len == 0) {
1738 ct_static_init(); /* To do: at compile time */
1741 s->compressed_len = 0L;
1743 s->l_desc.dyn_tree = s->dyn_ltree;
1744 s->l_desc.stat_desc = &static_l_desc;
1746 s->d_desc.dyn_tree = s->dyn_dtree;
1747 s->d_desc.stat_desc = &static_d_desc;
1749 s->bl_desc.dyn_tree = s->bl_tree;
1750 s->bl_desc.stat_desc = &static_bl_desc;
1754 s->last_eob_len = 8; /* enough lookahead for inflate */
1758 s->blocks_in_packet = 0;
1760 /* Initialize the first block of the first file: */
1764 /* ===========================================================================
1765 * Initialize a new block.
1767 local void init_block(s)
1770 int n; /* iterates over tree elements */
1772 /* Initialize the trees. */
1773 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1774 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1775 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1777 s->dyn_ltree[END_BLOCK].Freq = 1;
1778 s->opt_len = s->static_len = 0L;
1779 s->last_lit = s->matches = 0;
1783 /* Index within the heap array of least frequent node in the Huffman tree */
1786 /* ===========================================================================
1787 * Remove the smallest element from the heap and recreate the heap with
1788 * one less element. Updates heap and heap_len.
1790 #define pqremove(s, tree, top) \
1792 top = s->heap[SMALLEST]; \
1793 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1794 pqdownheap(s, tree, SMALLEST); \
1797 /* ===========================================================================
1798 * Compares to subtrees, using the tree depth as tie breaker when
1799 * the subtrees have equal frequency. This minimizes the worst case length.
1801 #define smaller(tree, n, m, depth) \
1802 (tree[n].Freq < tree[m].Freq || \
1803 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1805 /* ===========================================================================
1806 * Restore the heap property by moving down the tree starting at node k,
1807 * exchanging a node with the smallest of its two sons if necessary, stopping
1808 * when the heap property is re-established (each father smaller than its
1811 local void pqdownheap(s, tree, k)
1813 ct_data *tree; /* the tree to restore */
1814 int k; /* node to move down */
1817 int j = k << 1; /* left son of k */
1818 while (j <= s->heap_len) {
1819 /* Set j to the smallest of the two sons: */
1820 if (j < s->heap_len &&
1821 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1824 /* Exit if v is smaller than both sons */
1825 if (smaller(tree, v, s->heap[j], s->depth)) break;
1827 /* Exchange v with the smallest son */
1828 s->heap[k] = s->heap[j]; k = j;
1830 /* And continue down the tree, setting j to the left son of k */
1836 /* ===========================================================================
1837 * Compute the optimal bit lengths for a tree and update the total bit length
1838 * for the current block.
1839 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1840 * above are the tree nodes sorted by increasing frequency.
1841 * OUT assertions: the field len is set to the optimal bit length, the
1842 * array bl_count contains the frequencies for each bit length.
1843 * The length opt_len is updated; static_len is also updated if stree is
1846 local void gen_bitlen(s, desc)
1848 tree_desc *desc; /* the tree descriptor */
1850 ct_data *tree = desc->dyn_tree;
1851 int max_code = desc->max_code;
1852 ct_data *stree = desc->stat_desc->static_tree;
1853 intf *extra = desc->stat_desc->extra_bits;
1854 int base = desc->stat_desc->extra_base;
1855 int max_length = desc->stat_desc->max_length;
1856 int h; /* heap index */
1857 int n, m; /* iterate over the tree elements */
1858 int bits; /* bit length */
1859 int xbits; /* extra bits */
1860 ush f; /* frequency */
1861 int overflow = 0; /* number of elements with bit length too large */
1863 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1865 /* In a first pass, compute the optimal bit lengths (which may
1866 * overflow in the case of the bit length tree).
1868 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1870 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1872 bits = tree[tree[n].Dad].Len + 1;
1873 if (bits > max_length) bits = max_length, overflow++;
1874 tree[n].Len = (ush)bits;
1875 /* We overwrite tree[n].Dad which is no longer needed */
1877 if (n > max_code) continue; /* not a leaf node */
1879 s->bl_count[bits]++;
1881 if (n >= base) xbits = extra[n-base];
1883 s->opt_len += (ulg)f * (bits + xbits);
1884 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1886 if (overflow == 0) return;
1888 Trace((stderr,"\nbit length overflow\n"));
1889 /* This happens for example on obj2 and pic of the Calgary corpus */
1891 /* Find the first bit length which could increase: */
1893 bits = max_length-1;
1894 while (s->bl_count[bits] == 0) bits--;
1895 s->bl_count[bits]--; /* move one leaf down the tree */
1896 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1897 s->bl_count[max_length]--;
1898 /* The brother of the overflow item also moves one step up,
1899 * but this does not affect bl_count[max_length]
1902 } while (overflow > 0);
1904 /* Now recompute all bit lengths, scanning in increasing frequency.
1905 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1906 * lengths instead of fixing only the wrong ones. This idea is taken
1907 * from 'ar' written by Haruhiko Okumura.)
1909 for (bits = max_length; bits != 0; bits--) {
1910 n = s->bl_count[bits];
1913 if (m > max_code) continue;
1914 if (tree[m].Len != (unsigned) bits) {
1915 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1916 s->opt_len += ((long)bits - (long)tree[m].Len)
1917 *(long)tree[m].Freq;
1918 tree[m].Len = (ush)bits;
1925 /* ===========================================================================
1926 * Generate the codes for a given tree and bit counts (which need not be
1928 * IN assertion: the array bl_count contains the bit length statistics for
1929 * the given tree and the field len is set for all tree elements.
1930 * OUT assertion: the field code is set for all tree elements of non
1933 local void gen_codes (tree, max_code, bl_count)
1934 ct_data *tree; /* the tree to decorate */
1935 int max_code; /* largest code with non zero frequency */
1936 ushf *bl_count; /* number of codes at each bit length */
1938 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1939 ush code = 0; /* running code value */
1940 int bits; /* bit index */
1941 int n; /* code index */
1943 /* The distribution counts are first used to generate the code values
1944 * without bit reversal.
1946 for (bits = 1; bits <= MAX_BITS; bits++) {
1947 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1949 /* Check that the bit counts in bl_count are consistent. The last code
1952 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1953 "inconsistent bit counts");
1954 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1956 for (n = 0; n <= max_code; n++) {
1957 int len = tree[n].Len;
1958 if (len == 0) continue;
1959 /* Now reverse the bits */
1960 tree[n].Code = bi_reverse(next_code[len]++, len);
1962 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1963 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1967 /* ===========================================================================
1968 * Construct one Huffman tree and assigns the code bit strings and lengths.
1969 * Update the total bit length for the current block.
1970 * IN assertion: the field freq is set for all tree elements.
1971 * OUT assertions: the fields len and code are set to the optimal bit length
1972 * and corresponding code. The length opt_len is updated; static_len is
1973 * also updated if stree is not null. The field max_code is set.
1975 local void build_tree(s, desc)
1977 tree_desc *desc; /* the tree descriptor */
1979 ct_data *tree = desc->dyn_tree;
1980 ct_data *stree = desc->stat_desc->static_tree;
1981 int elems = desc->stat_desc->elems;
1982 int n, m; /* iterate over heap elements */
1983 int max_code = -1; /* largest code with non zero frequency */
1984 int node; /* new node being created */
1986 /* Construct the initial heap, with least frequent element in
1987 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
1988 * heap[0] is not used.
1990 s->heap_len = 0, s->heap_max = HEAP_SIZE;
1992 for (n = 0; n < elems; n++) {
1993 if (tree[n].Freq != 0) {
1994 s->heap[++(s->heap_len)] = max_code = n;
2001 /* The pkzip format requires that at least one distance code exists,
2002 * and that at least one bit should be sent even if there is only one
2003 * possible code. So to avoid special checks later on we force at least
2004 * two codes of non zero frequency.
2006 while (s->heap_len < 2) {
2007 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2008 tree[node].Freq = 1;
2010 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2011 /* node is 0 or 1 so it does not have extra bits */
2013 desc->max_code = max_code;
2015 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2016 * establish sub-heaps of increasing lengths:
2018 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2020 /* Construct the Huffman tree by repeatedly combining the least two
2023 node = elems; /* next internal node of the tree */
2025 pqremove(s, tree, n); /* n = node of least frequency */
2026 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2028 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2029 s->heap[--(s->heap_max)] = m;
2031 /* Create a new node father of n and m */
2032 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2033 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2034 tree[n].Dad = tree[m].Dad = (ush)node;
2036 if (tree == s->bl_tree) {
2037 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2038 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2041 /* and insert the new node in the heap */
2042 s->heap[SMALLEST] = node++;
2043 pqdownheap(s, tree, SMALLEST);
2045 } while (s->heap_len >= 2);
2047 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2049 /* At this point, the fields freq and dad are set. We can now
2050 * generate the bit lengths.
2052 gen_bitlen(s, (tree_desc *)desc);
2054 /* The field len is now set, we can generate the bit codes */
2055 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2058 /* ===========================================================================
2059 * Scan a literal or distance tree to determine the frequencies of the codes
2060 * in the bit length tree.
2062 local void scan_tree (s, tree, max_code)
2064 ct_data *tree; /* the tree to be scanned */
2065 int max_code; /* and its largest code of non zero frequency */
2067 int n; /* iterates over all tree elements */
2068 int prevlen = -1; /* last emitted length */
2069 int curlen; /* length of current code */
2070 int nextlen = tree[0].Len; /* length of next code */
2071 int count = 0; /* repeat count of the current code */
2072 int max_count = 7; /* max repeat count */
2073 int min_count = 4; /* min repeat count */
2075 if (nextlen == 0) max_count = 138, min_count = 3;
2076 tree[max_code+1].Len = (ush)0xffff; /* guard */
2078 for (n = 0; n <= max_code; n++) {
2079 curlen = nextlen; nextlen = tree[n+1].Len;
2080 if (++count < max_count && curlen == nextlen) {
2082 } else if (count < min_count) {
2083 s->bl_tree[curlen].Freq += count;
2084 } else if (curlen != 0) {
2085 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2086 s->bl_tree[REP_3_6].Freq++;
2087 } else if (count <= 10) {
2088 s->bl_tree[REPZ_3_10].Freq++;
2090 s->bl_tree[REPZ_11_138].Freq++;
2092 count = 0; prevlen = curlen;
2094 max_count = 138, min_count = 3;
2095 } else if (curlen == nextlen) {
2096 max_count = 6, min_count = 3;
2098 max_count = 7, min_count = 4;
2103 /* ===========================================================================
2104 * Send a literal or distance tree in compressed form, using the codes in
2107 local void send_tree (s, tree, max_code)
2109 ct_data *tree; /* the tree to be scanned */
2110 int max_code; /* and its largest code of non zero frequency */
2112 int n; /* iterates over all tree elements */
2113 int prevlen = -1; /* last emitted length */
2114 int curlen; /* length of current code */
2115 int nextlen = tree[0].Len; /* length of next code */
2116 int count = 0; /* repeat count of the current code */
2117 int max_count = 7; /* max repeat count */
2118 int min_count = 4; /* min repeat count */
2120 /* tree[max_code+1].Len = -1; */ /* guard already set */
2121 if (nextlen == 0) max_count = 138, min_count = 3;
2123 for (n = 0; n <= max_code; n++) {
2124 curlen = nextlen; nextlen = tree[n+1].Len;
2125 if (++count < max_count && curlen == nextlen) {
2127 } else if (count < min_count) {
2128 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2130 } else if (curlen != 0) {
2131 if (curlen != prevlen) {
2132 send_code(s, curlen, s->bl_tree); count--;
2134 Assert(count >= 3 && count <= 6, " 3_6?");
2135 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2137 } else if (count <= 10) {
2138 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2141 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2143 count = 0; prevlen = curlen;
2145 max_count = 138, min_count = 3;
2146 } else if (curlen == nextlen) {
2147 max_count = 6, min_count = 3;
2149 max_count = 7, min_count = 4;
2154 /* ===========================================================================
2155 * Construct the Huffman tree for the bit lengths and return the index in
2156 * bl_order of the last bit length code to send.
2158 local int build_bl_tree(s)
2161 int max_blindex; /* index of last bit length code of non zero freq */
2163 /* Determine the bit length frequencies for literal and distance trees */
2164 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2165 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2167 /* Build the bit length tree: */
2168 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2169 /* opt_len now includes the length of the tree representations, except
2170 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2173 /* Determine the number of bit length codes to send. The pkzip format
2174 * requires that at least 4 bit length codes be sent. (appnote.txt says
2175 * 3 but the actual value used is 4.)
2177 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2178 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2180 /* Update opt_len to include the bit length tree and counts */
2181 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2182 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2183 s->opt_len, s->static_len));
2188 /* ===========================================================================
2189 * Send the header for a block using dynamic Huffman trees: the counts, the
2190 * lengths of the bit length codes, the literal tree and the distance tree.
2191 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2193 local void send_all_trees(s, lcodes, dcodes, blcodes)
2195 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2197 int rank; /* index in bl_order */
2199 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2200 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2202 Tracev((stderr, "\nbl counts: "));
2203 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2204 send_bits(s, dcodes-1, 5);
2205 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2206 for (rank = 0; rank < blcodes; rank++) {
2207 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2208 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2210 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2212 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2213 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2215 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2216 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2219 /* ===========================================================================
2220 * Send a stored block
2222 local void ct_stored_block(s, buf, stored_len, eof)
2224 charf *buf; /* input block */
2225 ulg stored_len; /* length of input block */
2226 int eof; /* true if this is the last block for a file */
2228 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2229 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2230 s->compressed_len += (stored_len + 4) << 3;
2232 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2235 /* Send just the `stored block' type code without any length bytes or data.
2237 local void ct_stored_type_only(s)
2240 send_bits(s, (STORED_BLOCK << 1), 3);
2242 s->compressed_len = (s->compressed_len + 3) & ~7L;
2246 /* ===========================================================================
2247 * Send one empty static block to give enough lookahead for inflate.
2248 * This takes 10 bits, of which 7 may remain in the bit buffer.
2249 * The current inflate code requires 9 bits of lookahead. If the EOB
2250 * code for the previous block was coded on 5 bits or less, inflate
2251 * may have only 5+3 bits of lookahead to decode this EOB.
2252 * (There are no problems if the previous block is stored or fixed.)
2254 local void ct_align(s)
2257 send_bits(s, STATIC_TREES<<1, 3);
2258 send_code(s, END_BLOCK, static_ltree);
2259 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2261 /* Of the 10 bits for the empty block, we have already sent
2262 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2263 * block was thus its length plus what we have just sent.
2265 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2266 send_bits(s, STATIC_TREES<<1, 3);
2267 send_code(s, END_BLOCK, static_ltree);
2268 s->compressed_len += 10L;
2271 s->last_eob_len = 7;
2274 /* ===========================================================================
2275 * Determine the best encoding for the current block: dynamic trees, static
2276 * trees or store, and output the encoded block to the zip file. This function
2277 * returns the total compressed length for the file so far.
2279 local ulg ct_flush_block(s, buf, stored_len, flush)
2281 charf *buf; /* input block, or NULL if too old */
2282 ulg stored_len; /* length of input block */
2283 int flush; /* Z_FINISH if this is the last block for a file */
2285 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2286 int max_blindex; /* index of last bit length code of non zero freq */
2287 int eof = flush == Z_FINISH;
2289 ++s->blocks_in_packet;
2291 /* Check if the file is ascii or binary */
2292 if (s->data_type == UNKNOWN) set_data_type(s);
2294 /* Construct the literal and distance trees */
2295 build_tree(s, (tree_desc *)(&(s->l_desc)));
2296 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2299 build_tree(s, (tree_desc *)(&(s->d_desc)));
2300 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2302 /* At this point, opt_len and static_len are the total bit lengths of
2303 * the compressed block data, excluding the tree representations.
2306 /* Build the bit length tree for the above two trees, and get the index
2307 * in bl_order of the last bit length code to send.
2309 max_blindex = build_bl_tree(s);
2311 /* Determine the best encoding. Compute first the block length in bytes */
2312 opt_lenb = (s->opt_len+3+7)>>3;
2313 static_lenb = (s->static_len+3+7)>>3;
2315 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2316 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2319 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2321 /* If compression failed and this is the first and last block,
2322 * and if the .zip file can be seeked (to rewrite the local header),
2323 * the whole file is transformed into a stored file:
2325 #ifdef STORED_FILE_OK
2326 # ifdef FORCE_STORED_FILE
2327 if (eof && compressed_len == 0L) /* force stored file */
2329 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2332 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2333 if (buf == (charf*)0) error ("block vanished");
2335 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2336 s->compressed_len = stored_len << 3;
2339 #endif /* STORED_FILE_OK */
2341 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
2342 * compression, and this block contains all the data since the last
2343 * time we used Z_PACKET_FLUSH, then just omit this block completely
2346 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
2347 && opt_lenb > stored_len - s->minCompr) {
2348 s->blocks_in_packet = 0;
2349 /* output nothing */
2353 if (buf != (char*)0) /* force stored block */
2355 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2356 /* 4: two words for the lengths */
2359 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2360 * Otherwise we can't have processed more than WSIZE input bytes since
2361 * the last block flush, because compression would have been
2362 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2363 * transform a block into a stored block.
2365 ct_stored_block(s, buf, stored_len, eof);
2369 if (static_lenb >= 0) /* force static trees */
2371 if (static_lenb == opt_lenb)
2374 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2375 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2376 s->compressed_len += 3 + s->static_len;
2378 send_bits(s, (DYN_TREES<<1)+eof, 3);
2379 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2381 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2382 s->compressed_len += 3 + s->opt_len;
2384 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2389 s->compressed_len += 7; /* align on byte boundary */
2391 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2392 s->compressed_len-7*eof));
2394 return s->compressed_len >> 3;
2397 /* ===========================================================================
2398 * Save the match info and tally the frequency counts. Return true if
2399 * the current block must be flushed.
2401 local int ct_tally (s, dist, lc)
2403 int dist; /* distance of matched string */
2404 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2406 s->d_buf[s->last_lit] = (ush)dist;
2407 s->l_buf[s->last_lit++] = (uch)lc;
2409 /* lc is the unmatched char */
2410 s->dyn_ltree[lc].Freq++;
2413 /* Here, lc is the match length - MIN_MATCH */
2414 dist--; /* dist = match distance - 1 */
2415 Assert((ush)dist < (ush)MAX_DIST(s) &&
2416 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2417 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2419 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2420 s->dyn_dtree[d_code(dist)].Freq++;
2423 /* Try to guess if it is profitable to stop the current block here */
2424 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2425 /* Compute an upper bound for the compressed length */
2426 ulg out_length = (ulg)s->last_lit*8L;
2427 ulg in_length = (ulg)s->strstart - s->block_start;
2429 for (dcode = 0; dcode < D_CODES; dcode++) {
2430 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2431 (5L+extra_dbits[dcode]);
2434 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2435 s->last_lit, in_length, out_length,
2436 100L - out_length*100L/in_length));
2437 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2439 return (s->last_lit == s->lit_bufsize-1);
2440 /* We avoid equality with lit_bufsize because of wraparound at 64K
2441 * on 16 bit machines and because stored blocks are restricted to
2446 /* ===========================================================================
2447 * Send the block data compressed using the given Huffman trees
2449 local void compress_block(s, ltree, dtree)
2451 ct_data *ltree; /* literal tree */
2452 ct_data *dtree; /* distance tree */
2454 unsigned dist; /* distance of matched string */
2455 int lc; /* match length or unmatched char (if dist == 0) */
2456 unsigned lx = 0; /* running index in l_buf */
2457 unsigned code; /* the code to send */
2458 int extra; /* number of extra bits to send */
2460 if (s->last_lit != 0) do {
2461 dist = s->d_buf[lx];
2462 lc = s->l_buf[lx++];
2464 send_code(s, lc, ltree); /* send a literal byte */
2465 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2467 /* Here, lc is the match length - MIN_MATCH */
2468 code = length_code[lc];
2469 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2470 extra = extra_lbits[code];
2472 lc -= base_length[code];
2473 send_bits(s, lc, extra); /* send the extra length bits */
2475 dist--; /* dist is now the match distance - 1 */
2476 code = d_code(dist);
2477 Assert (code < D_CODES, "bad d_code");
2479 send_code(s, code, dtree); /* send the distance code */
2480 extra = extra_dbits[code];
2482 dist -= base_dist[code];
2483 send_bits(s, dist, extra); /* send the extra distance bits */
2485 } /* literal or match pair ? */
2487 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2488 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2490 } while (lx < s->last_lit);
2492 send_code(s, END_BLOCK, ltree);
2493 s->last_eob_len = ltree[END_BLOCK].Len;
2496 /* ===========================================================================
2497 * Set the data type to ASCII or BINARY, using a crude approximation:
2498 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2499 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2500 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2502 local void set_data_type(s)
2506 unsigned ascii_freq = 0;
2507 unsigned bin_freq = 0;
2508 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2509 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2510 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2511 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2514 /* ===========================================================================
2515 * Reverse the first len bits of a code, using straightforward code (a faster
2516 * method would use a table)
2517 * IN assertion: 1 <= len <= 15
2519 local unsigned bi_reverse(code, len)
2520 unsigned code; /* the value to invert */
2521 int len; /* its bit length */
2523 register unsigned res = 0;
2526 code >>= 1, res <<= 1;
2527 } while (--len > 0);
2531 /* ===========================================================================
2532 * Flush the bit buffer, keeping at most 7 bits in it.
2534 local void bi_flush(s)
2537 if (s->bi_valid == 16) {
2538 put_short(s, s->bi_buf);
2541 } else if (s->bi_valid >= 8) {
2542 put_byte(s, (Byte)s->bi_buf);
2548 /* ===========================================================================
2549 * Flush the bit buffer and align the output on a byte boundary
2551 local void bi_windup(s)
2554 if (s->bi_valid > 8) {
2555 put_short(s, s->bi_buf);
2556 } else if (s->bi_valid > 0) {
2557 put_byte(s, (Byte)s->bi_buf);
2562 s->bits_sent = (s->bits_sent+7) & ~7;
2566 /* ===========================================================================
2567 * Copy a stored block, storing first the length and its
2568 * one's complement if requested.
2570 local void copy_block(s, buf, len, header)
2572 charf *buf; /* the input data */
2573 unsigned len; /* its length */
2574 int header; /* true if block header must be written */
2576 bi_windup(s); /* align on byte boundary */
2577 s->last_eob_len = 8; /* enough lookahead for inflate */
2580 put_short(s, (ush)len);
2581 put_short(s, (ush)~len);
2583 s->bits_sent += 2*16;
2587 s->bits_sent += (ulg)len<<3;
2590 put_byte(s, *buf++);
2596 /* infblock.h -- header to use infblock.c
2597 * Copyright (C) 1995 Mark Adler
2598 * For conditions of distribution and use, see copyright notice in zlib.h
2601 /* WARNING: this file should *not* be used by applications. It is
2602 part of the implementation of the compression library and is
2603 subject to change. Applications should only use zlib.h.
2606 struct inflate_blocks_state;
2607 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2609 local inflate_blocks_statef * inflate_blocks_new OF((
2611 check_func c, /* check function */
2612 uInt w)); /* window size */
2614 local int inflate_blocks OF((
2615 inflate_blocks_statef *,
2617 int)); /* initial return code */
2619 local void inflate_blocks_reset OF((
2620 inflate_blocks_statef *,
2622 uLongf *)); /* check value on output */
2624 local int inflate_blocks_free OF((
2625 inflate_blocks_statef *,
2627 uLongf *)); /* check value on output */
2629 local int inflate_addhistory OF((
2630 inflate_blocks_statef *,
2633 local int inflate_packet_flush OF((
2634 inflate_blocks_statef *));
2637 /* inftrees.h -- header to use inftrees.c
2638 * Copyright (C) 1995 Mark Adler
2639 * For conditions of distribution and use, see copyright notice in zlib.h
2642 /* WARNING: this file should *not* be used by applications. It is
2643 part of the implementation of the compression library and is
2644 subject to change. Applications should only use zlib.h.
2647 /* Huffman code lookup table entry--this entry is four bytes for machines
2648 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2650 typedef struct inflate_huft_s FAR inflate_huft;
2652 struct inflate_huft_s {
2655 Byte Exop; /* number of extra bits or operation */
2656 Byte Bits; /* number of bits in this code or subcode */
2658 uInt Nalloc; /* number of these allocated here */
2659 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2660 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2662 uInt Base; /* literal, length base, or distance base */
2663 inflate_huft *Next; /* pointer to next level of table */
2668 local uInt inflate_hufts;
2671 local int inflate_trees_bits OF((
2672 uIntf *, /* 19 code lengths */
2673 uIntf *, /* bits tree desired/actual depth */
2674 inflate_huft * FAR *, /* bits tree result */
2675 z_stream *)); /* for zalloc, zfree functions */
2677 local int inflate_trees_dynamic OF((
2678 uInt, /* number of literal/length codes */
2679 uInt, /* number of distance codes */
2680 uIntf *, /* that many (total) code lengths */
2681 uIntf *, /* literal desired/actual bit depth */
2682 uIntf *, /* distance desired/actual bit depth */
2683 inflate_huft * FAR *, /* literal/length tree result */
2684 inflate_huft * FAR *, /* distance tree result */
2685 z_stream *)); /* for zalloc, zfree functions */
2687 local int inflate_trees_fixed OF((
2688 uIntf *, /* literal desired/actual bit depth */
2689 uIntf *, /* distance desired/actual bit depth */
2690 inflate_huft * FAR *, /* literal/length tree result */
2691 inflate_huft * FAR *)); /* distance tree result */
2693 local int inflate_trees_free OF((
2694 inflate_huft *, /* tables to free */
2695 z_stream *)); /* for zfree function */
2699 /* infcodes.h -- header to use infcodes.c
2700 * Copyright (C) 1995 Mark Adler
2701 * For conditions of distribution and use, see copyright notice in zlib.h
2704 /* WARNING: this file should *not* be used by applications. It is
2705 part of the implementation of the compression library and is
2706 subject to change. Applications should only use zlib.h.
2709 struct inflate_codes_state;
2710 typedef struct inflate_codes_state FAR inflate_codes_statef;
2712 local inflate_codes_statef *inflate_codes_new OF((
2714 inflate_huft *, inflate_huft *,
2717 local int inflate_codes OF((
2718 inflate_blocks_statef *,
2722 local void inflate_codes_free OF((
2723 inflate_codes_statef *,
2728 /* inflate.c -- zlib interface to inflate modules
2729 * Copyright (C) 1995 Mark Adler
2730 * For conditions of distribution and use, see copyright notice in zlib.h
2733 /* inflate private state */
2734 struct internal_state {
2738 METHOD, /* waiting for method byte */
2739 FLAG, /* waiting for flag byte */
2740 BLOCKS, /* decompressing blocks */
2741 CHECK4, /* four check bytes to go */
2742 CHECK3, /* three check bytes to go */
2743 CHECK2, /* two check bytes to go */
2744 CHECK1, /* one check byte to go */
2745 DONE, /* finished check, done */
2746 BAD} /* got an error--stay here */
2747 mode; /* current inflate mode */
2749 /* mode dependent information */
2751 uInt method; /* if FLAGS, method byte */
2753 uLong was; /* computed check value */
2754 uLong need; /* stream check value */
2755 } check; /* if CHECK, check values to compare */
2756 uInt marker; /* if BAD, inflateSync's marker bytes count */
2757 } sub; /* submode */
2759 /* mode independent information */
2760 int nowrap; /* flag for no wrapper */
2761 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2762 inflate_blocks_statef
2763 *blocks; /* current inflate_blocks state */
2773 if (z == Z_NULL || z->state == Z_NULL)
2774 return Z_STREAM_ERROR;
2775 z->total_in = z->total_out = 0;
2777 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2778 inflate_blocks_reset(z->state->blocks, z, &c);
2779 Trace((stderr, "inflate: reset\n"));
2789 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2790 return Z_STREAM_ERROR;
2791 if (z->state->blocks != Z_NULL)
2792 inflate_blocks_free(z->state->blocks, z, &c);
2793 ZFREE(z, z->state, sizeof(struct internal_state));
2795 Trace((stderr, "inflate: end\n"));
2800 int inflateInit2(z, w)
2804 /* initialize state */
2806 return Z_STREAM_ERROR;
2807 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2808 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2809 if ((z->state = (struct internal_state FAR *)
2810 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2812 z->state->blocks = Z_NULL;
2814 /* handle undocumented nowrap option (no zlib header or check) */
2815 z->state->nowrap = 0;
2819 z->state->nowrap = 1;
2822 /* set window size */
2823 if (w < 8 || w > 15)
2826 return Z_STREAM_ERROR;
2828 z->state->wbits = (uInt)w;
2830 /* create inflate_blocks state */
2831 if ((z->state->blocks =
2832 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2838 Trace((stderr, "inflate: allocated\n"));
2849 return inflateInit2(z, DEF_WBITS);
2853 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2854 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2863 if (z == Z_NULL || z->next_in == Z_NULL)
2864 return Z_STREAM_ERROR;
2866 while (1) switch (z->state->mode)
2870 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2872 z->state->mode = BAD;
2873 z->msg = "unknown compression method";
2874 z->state->sub.marker = 5; /* can't try inflateSync */
2877 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2879 z->state->mode = BAD;
2880 z->msg = "invalid window size";
2881 z->state->sub.marker = 5; /* can't try inflateSync */
2884 z->state->mode = FLAG;
2887 if ((b = NEXTBYTE) & 0x20)
2889 z->state->mode = BAD;
2890 z->msg = "invalid reserved bit";
2891 z->state->sub.marker = 5; /* can't try inflateSync */
2894 if (((z->state->sub.method << 8) + b) % 31)
2896 z->state->mode = BAD;
2897 z->msg = "incorrect header check";
2898 z->state->sub.marker = 5; /* can't try inflateSync */
2901 Trace((stderr, "inflate: zlib header ok\n"));
2902 z->state->mode = BLOCKS;
2904 r = inflate_blocks(z->state->blocks, z, r);
2905 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2906 r = inflate_packet_flush(z->state->blocks);
2907 if (r == Z_DATA_ERROR)
2909 z->state->mode = BAD;
2910 z->state->sub.marker = 0; /* can try inflateSync */
2913 if (r != Z_STREAM_END)
2916 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2917 if (z->state->nowrap)
2919 z->state->mode = DONE;
2922 z->state->mode = CHECK4;
2925 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2926 z->state->mode = CHECK3;
2929 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2930 z->state->mode = CHECK2;
2933 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2934 z->state->mode = CHECK1;
2937 z->state->sub.check.need += (uLong)NEXTBYTE;
2939 if (z->state->sub.check.was != z->state->sub.check.need)
2941 z->state->mode = BAD;
2942 z->msg = "incorrect data check";
2943 z->state->sub.marker = 5; /* can't try inflateSync */
2946 Trace((stderr, "inflate: zlib check ok\n"));
2947 z->state->mode = DONE;
2949 return Z_STREAM_END;
2951 return Z_DATA_ERROR;
2953 return Z_STREAM_ERROR;
2957 if (f != Z_PACKET_FLUSH)
2959 z->state->mode = BAD;
2960 z->state->sub.marker = 0; /* can try inflateSync */
2961 return Z_DATA_ERROR;
2965 * This subroutine adds the data at next_in/avail_in to the output history
2966 * without performing any output. The output buffer must be "caught up";
2967 * i.e. no pending output (hence s->read equals s->write), and the state must
2968 * be BLOCKS (i.e. we should be willing to see the start of a series of
2969 * BLOCKS). On exit, the output will also be caught up, and the checksum
2970 * will have been updated if need be.
2973 int inflateIncomp(z)
2976 if (z->state->mode != BLOCKS)
2977 return Z_DATA_ERROR;
2978 return inflate_addhistory(z->state->blocks, z);
2985 uInt n; /* number of bytes to look at */
2986 Bytef *p; /* pointer to bytes */
2987 uInt m; /* number of marker bytes found in a row */
2988 uLong r, w; /* temporaries to save total_in and total_out */
2991 if (z == Z_NULL || z->state == Z_NULL)
2992 return Z_STREAM_ERROR;
2993 if (z->state->mode != BAD)
2995 z->state->mode = BAD;
2996 z->state->sub.marker = 0;
2998 if ((n = z->avail_in) == 0)
3001 m = z->state->sub.marker;
3006 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3016 z->total_in += p - z->next_in;
3019 z->state->sub.marker = m;
3021 /* return no joy or set up to restart on a new block */
3023 return Z_DATA_ERROR;
3024 r = z->total_in; w = z->total_out;
3026 z->total_in = r; z->total_out = w;
3027 z->state->mode = BLOCKS;
3035 /* infutil.h -- types and macros common to blocks and codes
3036 * Copyright (C) 1995 Mark Adler
3037 * For conditions of distribution and use, see copyright notice in zlib.h
3040 /* WARNING: this file should *not* be used by applications. It is
3041 part of the implementation of the compression library and is
3042 subject to change. Applications should only use zlib.h.
3045 /* inflate blocks semi-private state */
3046 struct inflate_blocks_state {
3050 TYPE, /* get type bits (3, including end bit) */
3051 LENS, /* get lengths for stored */
3052 STORED, /* processing stored block */
3053 TABLE, /* get table lengths */
3054 BTREE, /* get bit lengths tree for a dynamic block */
3055 DTREE, /* get length, distance trees for a dynamic block */
3056 CODES, /* processing fixed or dynamic block */
3057 DRY, /* output remaining window bytes */
3058 DONEB, /* finished last block, done */
3059 BADB} /* got a data error--stuck here */
3060 mode; /* current inflate_block mode */
3062 /* mode dependent information */
3064 uInt left; /* if STORED, bytes left to copy */
3066 uInt table; /* table lengths (14 bits) */
3067 uInt index; /* index into blens (or border) */
3068 uIntf *blens; /* bit lengths of codes */
3069 uInt bb; /* bit length tree depth */
3070 inflate_huft *tb; /* bit length decoding tree */
3071 int nblens; /* # elements allocated at blens */
3072 } trees; /* if DTREE, decoding info for trees */
3074 inflate_huft *tl, *td; /* trees to free */
3075 inflate_codes_statef
3077 } decode; /* if CODES, current state */
3078 } sub; /* submode */
3079 uInt last; /* true if this block is the last block */
3081 /* mode independent information */
3082 uInt bitk; /* bits in bit buffer */
3083 uLong bitb; /* bit buffer */
3084 Bytef *window; /* sliding window */
3085 Bytef *end; /* one byte after sliding window */
3086 Bytef *read; /* window read pointer */
3087 Bytef *write; /* window write pointer */
3088 check_func checkfn; /* check function */
3089 uLong check; /* check on output */
3094 /* defines for inflate input/output */
3095 /* update pointers and return */
3096 #define UPDBITS {s->bitb=b;s->bitk=k;}
3097 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3098 #define UPDOUT {s->write=q;}
3099 #define UPDATE {UPDBITS UPDIN UPDOUT}
3100 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3101 /* get bytes and bits */
3102 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3103 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3104 #define NEXTBYTE (n--,*p++)
3105 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3106 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3108 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3109 #define LOADOUT {q=s->write;m=WAVAIL;}
3110 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3111 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3112 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3113 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3114 /* load local pointers */
3115 #define LOAD {LOADIN LOADOUT}
3117 /* And'ing with mask[n] masks the lower n bits */
3118 local uInt inflate_mask[] = {
3120 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3121 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3124 /* copy as much as possible from the sliding window to the output area */
3125 local int inflate_flush OF((
3126 inflate_blocks_statef *,
3131 /* inffast.h -- header to use inffast.c
3132 * Copyright (C) 1995 Mark Adler
3133 * For conditions of distribution and use, see copyright notice in zlib.h
3136 /* WARNING: this file should *not* be used by applications. It is
3137 part of the implementation of the compression library and is
3138 subject to change. Applications should only use zlib.h.
3141 local int inflate_fast OF((
3146 inflate_blocks_statef *,
3151 /* infblock.c -- interpret and process block types to last block
3152 * Copyright (C) 1995 Mark Adler
3153 * For conditions of distribution and use, see copyright notice in zlib.h
3156 /* Table for deflate from PKZIP's appnote.txt. */
3157 local uInt border[] = { /* Order of the bit length code lengths */
3158 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3161 Notes beyond the 1.93a appnote.txt:
3163 1. Distance pointers never point before the beginning of the output
3165 2. Distance pointers can point back across blocks, up to 32k away.
3166 3. There is an implied maximum of 7 bits for the bit length table and
3167 15 bits for the actual data.
3168 4. If only one code exists, then it is encoded using one bit. (Zero
3169 would be more efficient, but perhaps a little confusing.) If two
3170 codes exist, they are coded using one bit each (0 and 1).
3171 5. There is no way of sending zero distance codes--a dummy must be
3172 sent if there are none. (History: a pre 2.0 version of PKZIP would
3173 store blocks with no distance codes, but this was discovered to be
3174 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3175 zero distance codes, which is sent as one code of zero bits in
3177 6. There are up to 286 literal/length codes. Code 256 represents the
3178 end-of-block. Note however that the static length tree defines
3179 288 codes just to fill out the Huffman codes. Codes 286 and 287
3180 cannot be used though, since there is no length base or extra bits
3181 defined for them. Similarily, there are up to 30 distance codes.
3182 However, static trees define 32 codes (all 5 bits) to fill out the
3183 Huffman codes, but the last two had better not show up in the data.
3184 7. Unzip can check dynamic Huffman blocks for complete code sets.
3185 The exception is that a single code would not be complete (see #4).
3186 8. The five bits following the block type is really the number of
3187 literal codes sent minus 257.
3188 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3189 (1+6+6). Therefore, to output three times the length, you output
3190 three codes (1+1+1), whereas to output four times the same length,
3191 you only need two codes (1+3). Hmm.
3192 10. In the tree reconstruction algorithm, Code = Code + Increment
3193 only if BitLength(i) is not zero. (Pretty obvious.)
3194 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3195 12. Note: length code 284 can represent 227-258, but length code 285
3196 really is 258. The last length deserves its own, short code
3197 since it gets used a lot in very redundant files. The length
3198 258 is special since 258 - 3 (the min match length) is 255.
3199 13. The literal/length and distance code bit lengths are read as a
3200 single stream of lengths. It is possible (and advantageous) for
3201 a repeat code (16, 17, or 18) to go across the boundary between
3202 the two sets of lengths.
3206 void inflate_blocks_reset(s, z, c)
3207 inflate_blocks_statef *s;
3211 if (s->checkfn != Z_NULL)
3213 if (s->mode == BTREE || s->mode == DTREE)
3214 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3215 if (s->mode == CODES)
3217 inflate_codes_free(s->sub.decode.codes, z);
3218 inflate_trees_free(s->sub.decode.td, z);
3219 inflate_trees_free(s->sub.decode.tl, z);
3224 s->read = s->write = s->window;
3225 if (s->checkfn != Z_NULL)
3226 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3227 Trace((stderr, "inflate: blocks reset\n"));
3231 inflate_blocks_statef *inflate_blocks_new(z, c, w)
3236 inflate_blocks_statef *s;
3238 if ((s = (inflate_blocks_statef *)ZALLOC
3239 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3241 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3243 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3246 s->end = s->window + w;
3249 Trace((stderr, "inflate: blocks allocated\n"));
3250 inflate_blocks_reset(s, z, &s->check);
3255 int inflate_blocks(s, z, r)
3256 inflate_blocks_statef *s;
3260 uInt t; /* temporary storage */
3261 uLong b; /* bit buffer */
3262 uInt k; /* bits in bit buffer */
3263 Bytef *p; /* input data pointer */
3264 uInt n; /* bytes available there */
3265 Bytef *q; /* output window write pointer */
3266 uInt m; /* bytes to end of window or read pointer */
3268 /* copy input/output information to locals (UPDATE macro restores) */
3271 /* process input based on current state */
3272 while (1) switch (s->mode)
3280 case 0: /* stored */
3281 Trace((stderr, "inflate: stored block%s\n",
3282 s->last ? " (last)" : ""));
3284 t = k & 7; /* go to byte boundary */
3286 s->mode = LENS; /* get length of stored block */
3289 Trace((stderr, "inflate: fixed codes block%s\n",
3290 s->last ? " (last)" : ""));
3293 inflate_huft *tl, *td;
3295 inflate_trees_fixed(&bl, &bd, &tl, &td);
3296 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3297 if (s->sub.decode.codes == Z_NULL)
3302 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3303 s->sub.decode.td = Z_NULL;
3308 case 2: /* dynamic */
3309 Trace((stderr, "inflate: dynamic codes block%s\n",
3310 s->last ? " (last)" : ""));
3314 case 3: /* illegal */
3317 z->msg = "invalid block type";
3324 if (((~b) >> 16) != (b & 0xffff))
3327 z->msg = "invalid stored block lengths";
3331 s->sub.left = (uInt)b & 0xffff;
3332 b = k = 0; /* dump bits */
3333 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3334 s->mode = s->sub.left ? STORED : TYPE;
3346 if ((s->sub.left -= t) != 0)
3348 Tracev((stderr, "inflate: stored end, %lu total out\n",
3349 z->total_out + (q >= s->read ? q - s->read :
3350 (s->end - s->read) + (q - s->window))));
3351 s->mode = s->last ? DRY : TYPE;
3355 s->sub.trees.table = t = (uInt)b & 0x3fff;
3356 #ifndef PKZIP_BUG_WORKAROUND
3357 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3360 z->msg = "too many length or distance symbols";
3365 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3368 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3373 s->sub.trees.nblens = t;
3375 s->sub.trees.index = 0;
3376 Tracev((stderr, "inflate: table sizes ok\n"));
3379 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3382 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3385 while (s->sub.trees.index < 19)
3386 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3387 s->sub.trees.bb = 7;
3388 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3389 &s->sub.trees.tb, z);
3393 if (r == Z_DATA_ERROR)
3397 s->sub.trees.index = 0;
3398 Tracev((stderr, "inflate: bits tree ok\n"));
3401 while (t = s->sub.trees.table,
3402 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3407 t = s->sub.trees.bb;
3409 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3410 t = h->word.what.Bits;
3415 s->sub.trees.blens[s->sub.trees.index++] = c;
3417 else /* c == 16..18 */
3419 i = c == 18 ? 7 : c - 14;
3420 j = c == 18 ? 11 : 3;
3423 j += (uInt)b & inflate_mask[i];
3425 i = s->sub.trees.index;
3426 t = s->sub.trees.table;
3427 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3431 z->msg = "invalid bit length repeat";
3435 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3437 s->sub.trees.blens[i++] = c;
3439 s->sub.trees.index = i;
3442 inflate_trees_free(s->sub.trees.tb, z);
3443 s->sub.trees.tb = Z_NULL;
3446 inflate_huft *tl, *td;
3447 inflate_codes_statef *c;
3449 bl = 9; /* must be <= 9 for lookahead assumptions */
3450 bd = 6; /* must be <= 9 for lookahead assumptions */
3451 t = s->sub.trees.table;
3452 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3453 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3456 if (t == (uInt)Z_DATA_ERROR)
3461 Tracev((stderr, "inflate: trees ok\n"));
3462 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3464 inflate_trees_free(td, z);
3465 inflate_trees_free(tl, z);
3469 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3470 s->sub.decode.codes = c;
3471 s->sub.decode.tl = tl;
3472 s->sub.decode.td = td;
3477 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3478 return inflate_flush(s, z, r);
3480 inflate_codes_free(s->sub.decode.codes, z);
3481 inflate_trees_free(s->sub.decode.td, z);
3482 inflate_trees_free(s->sub.decode.tl, z);
3484 Tracev((stderr, "inflate: codes end, %lu total out\n",
3485 z->total_out + (q >= s->read ? q - s->read :
3486 (s->end - s->read) + (q - s->window))));
3492 if (k > 7) /* return unused byte, if any */
3494 Assert(k < 16, "inflate_codes grabbed too many bytes")
3497 p--; /* can always return one */
3502 if (s->read != s->write)
3518 int inflate_blocks_free(s, z, c)
3519 inflate_blocks_statef *s;
3523 inflate_blocks_reset(s, z, c);
3524 ZFREE(z, s->window, s->end - s->window);
3525 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3526 Trace((stderr, "inflate: blocks freed\n"));
3531 * This subroutine adds the data at next_in/avail_in to the output history
3532 * without performing any output. The output buffer must be "caught up";
3533 * i.e. no pending output (hence s->read equals s->write), and the state must
3534 * be BLOCKS (i.e. we should be willing to see the start of a series of
3535 * BLOCKS). On exit, the output will also be caught up, and the checksum
3536 * will have been updated if need be.
3538 local int inflate_addhistory(s, z)
3539 inflate_blocks_statef *s;
3542 uLong b; /* bit buffer */ /* NOT USED HERE */
3543 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3544 uInt t; /* temporary storage */
3545 Bytef *p; /* input data pointer */
3546 uInt n; /* bytes available there */
3547 Bytef *q; /* output window write pointer */
3548 uInt m; /* bytes to end of window or read pointer */
3550 if (s->read != s->write)
3551 return Z_STREAM_ERROR;
3552 if (s->mode != TYPE)
3553 return Z_DATA_ERROR;
3555 /* we're ready to rock */
3557 /* while there is input ready, copy to output buffer, moving
3558 * pointers as needed.
3561 t = n; /* how many to do */
3562 /* is there room until end of buffer? */
3564 /* update check information */
3565 if (s->checkfn != Z_NULL)
3566 s->check = (*s->checkfn)(s->check, q, t);
3572 s->read = q; /* drag read pointer forward */
3573 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
3575 s->read = q = s->window;
3585 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3586 * a `stored' block type value but not the (zero) length bytes.
3588 local int inflate_packet_flush(s)
3589 inflate_blocks_statef *s;
3591 if (s->mode != LENS)
3592 return Z_DATA_ERROR;
3599 /* inftrees.c -- generate Huffman trees for efficient decoding
3600 * Copyright (C) 1995 Mark Adler
3601 * For conditions of distribution and use, see copyright notice in zlib.h
3604 /* simplify the use of the inflate_huft type with some defines */
3605 #define base more.Base
3606 #define next more.Next
3607 #define exop word.what.Exop
3608 #define bits word.what.Bits
3611 local int huft_build OF((
3612 uIntf *, /* code lengths in bits */
3613 uInt, /* number of codes */
3614 uInt, /* number of "simple" codes */
3615 uIntf *, /* list of base values for non-simple codes */
3616 uIntf *, /* list of extra bits for non-simple codes */
3617 inflate_huft * FAR*,/* result: starting table */
3618 uIntf *, /* maximum lookup bits (returns actual) */
3619 z_stream *)); /* for zalloc function */
3621 local voidpf falloc OF((
3622 voidpf, /* opaque pointer (not used) */
3623 uInt, /* number of items */
3624 uInt)); /* size of item */
3626 local void ffree OF((
3627 voidpf q, /* opaque pointer (not used) */
3628 voidpf p, /* what to free (not used) */
3629 uInt n)); /* number of bytes (not used) */
3631 /* Tables for deflate from PKZIP's appnote.txt. */
3632 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3633 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3634 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3635 /* actually lengths - 2; also see note #13 above about 258 */
3636 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3637 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3638 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3639 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3640 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3641 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3642 8193, 12289, 16385, 24577};
3643 local uInt cpdext[] = { /* Extra bits for distance codes */
3644 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3645 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3649 Huffman code decoding is performed using a multi-level table lookup.
3650 The fastest way to decode is to simply build a lookup table whose
3651 size is determined by the longest code. However, the time it takes
3652 to build this table can also be a factor if the data being decoded
3653 is not very long. The most common codes are necessarily the
3654 shortest codes, so those codes dominate the decoding time, and hence
3655 the speed. The idea is you can have a shorter table that decodes the
3656 shorter, more probable codes, and then point to subsidiary tables for
3657 the longer codes. The time it costs to decode the longer codes is
3658 then traded against the time it takes to make longer tables.
3660 This results of this trade are in the variables lbits and dbits
3661 below. lbits is the number of bits the first level table for literal/
3662 length codes can decode in one step, and dbits is the same thing for
3663 the distance codes. Subsequent tables are also less than or equal to
3664 those sizes. These values may be adjusted either when all of the
3665 codes are shorter than that, in which case the longest code length in
3666 bits is used, or when the shortest code is *longer* than the requested
3667 table size, in which case the length of the shortest code in bits is
3670 There are two different values for the two tables, since they code a
3671 different number of possibilities each. The literal/length table
3672 codes 286 possible values, or in a flat code, a little over eight
3673 bits. The distance table codes 30 possible values, or a little less
3674 than five bits, flat. The optimum values for speed end up being
3675 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3676 The optimum values may differ though from machine to machine, and
3677 possibly even between compilers. Your mileage may vary.
3681 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3682 #define BMAX 15 /* maximum bit length of any code */
3683 #define N_MAX 288 /* maximum number of codes in any set */
3689 local int huft_build(b, n, s, d, e, t, m, zs)
3690 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3691 uInt n; /* number of codes (assumed <= N_MAX) */
3692 uInt s; /* number of simple-valued codes (0..s-1) */
3693 uIntf *d; /* list of base values for non-simple codes */
3694 uIntf *e; /* list of extra bits for non-simple codes */
3695 inflate_huft * FAR *t; /* result: starting table */
3696 uIntf *m; /* maximum lookup bits, returns actual */
3697 z_stream *zs; /* for zalloc function */
3698 /* Given a list of code lengths and a maximum table size, make a set of
3699 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3700 if the given code set is incomplete (the tables are still built in this
3701 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3702 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3705 uInt a; /* counter for codes of length k */
3706 uInt c[BMAX+1]; /* bit length count table */
3707 uInt f; /* i repeats in table every f entries */
3708 int g; /* maximum code length */
3709 int h; /* table level */
3710 register uInt i; /* counter, current code */
3711 register uInt j; /* counter */
3712 register int k; /* number of bits in current code */
3713 int l; /* bits per table (returned in m) */
3714 register uIntf *p; /* pointer into c[], b[], or v[] */
3715 inflate_huft *q; /* points to current table */
3716 struct inflate_huft_s r; /* table entry for structure assignment */
3717 inflate_huft *u[BMAX]; /* table stack */
3718 uInt v[N_MAX]; /* values in order of bit length */
3719 register int w; /* bits before this table == (l * h) */
3720 uInt x[BMAX+1]; /* bit offsets, then code stack */
3721 uIntf *xp; /* pointer into x */
3722 int y; /* number of dummy codes added */
3723 uInt z; /* number of entries in current table */
3726 /* Generate counts for each bit length */
3728 #define C0 *p++ = 0;
3729 #define C2 C0 C0 C0 C0
3730 #define C4 C2 C2 C2 C2
3731 C4 /* clear c[]--assume BMAX+1 is 16 */
3734 c[*p++]++; /* assume all entries <= BMAX */
3736 if (c[0] == n) /* null input--all zero length codes */
3738 *t = (inflate_huft *)Z_NULL;
3744 /* Find minimum and maximum length, bound *m by those */
3746 for (j = 1; j <= BMAX; j++)
3749 k = j; /* minimum code length */
3752 for (i = BMAX; i; i--)
3755 g = i; /* maximum code length */
3761 /* Adjust last length count to fill out codes, if needed */
3762 for (y = 1 << j; j < i; j++, y <<= 1)
3763 if ((y -= c[j]) < 0)
3764 return Z_DATA_ERROR;
3765 if ((y -= c[i]) < 0)
3766 return Z_DATA_ERROR;
3770 /* Generate starting offsets into the value table for each length */
3772 p = c + 1; xp = x + 2;
3773 while (--i) { /* note that i == g from above */
3774 *xp++ = (j += *p++);
3778 /* Make a table of values in order of bit lengths */
3781 if ((j = *p++) != 0)
3786 /* Generate the Huffman codes and for each, make the table entries */
3787 x[0] = i = 0; /* first Huffman code is zero */
3788 p = v; /* grab values in bit order */
3789 h = -1; /* no tables yet--level -1 */
3790 w = -l; /* bits decoded == (l * h) */
3791 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3792 q = (inflate_huft *)Z_NULL; /* ditto */
3795 /* go through the bit lengths (k already is bits in shortest code) */
3801 /* here i is the Huffman code of length k bits for value *p */
3802 /* make tables up to required level */
3806 w += l; /* previous table always l bits */
3808 /* compute minimum size table less than or equal to l bits */
3809 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3810 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3811 { /* too few codes for k-w bit table */
3812 f -= a + 1; /* deduct codes from patterns left */
3815 while (++j < z) /* try smaller tables up to z bits */
3817 if ((f <<= 1) <= *++xp)
3818 break; /* enough codes to use up j bits */
3819 f -= *xp; /* else deduct codes from patterns */
3822 z = 1 << j; /* table entries for j-bit table */
3824 /* allocate and link in new table */
3825 if ((q = (inflate_huft *)ZALLOC
3826 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3829 inflate_trees_free(u[0], zs);
3830 return Z_MEM_ERROR; /* not enough memory */
3832 q->word.Nalloc = z + 1;
3834 inflate_hufts += z + 1;
3836 *t = q + 1; /* link to list for huft_free() */
3837 *(t = &(q->next)) = Z_NULL;
3838 u[h] = ++q; /* table starts after link */
3840 /* connect to last table, if there is one */
3843 x[h] = i; /* save pattern for backing up */
3844 r.bits = (Byte)l; /* bits to dump before this table */
3845 r.exop = (Byte)j; /* bits in this table */
3846 r.next = q; /* pointer to this table */
3847 j = i >> (w - l); /* (get around Turbo C bug) */
3848 u[h-1][j] = r; /* connect to last table */
3852 /* set up table entry in r */
3853 r.bits = (Byte)(k - w);
3855 r.exop = 128 + 64; /* out of values--invalid code */
3858 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3859 r.base = *p++; /* simple code is just the value */
3863 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3864 r.base = d[*p++ - s];
3867 /* fill code-like entries with r */
3869 for (j = i >> w; j < z; j += f)
3872 /* backwards increment the k-bit code i */
3873 for (j = 1 << (k - 1); i & j; j >>= 1)
3877 /* backup over finished tables */
3878 while ((i & ((1 << w) - 1)) != x[h])
3880 h--; /* don't need to update q */
3887 /* Return Z_BUF_ERROR if we were given an incomplete table */
3888 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3892 int inflate_trees_bits(c, bb, tb, z)
3893 uIntf *c; /* 19 code lengths */
3894 uIntf *bb; /* bits tree desired/actual depth */
3895 inflate_huft * FAR *tb; /* bits tree result */
3896 z_stream *z; /* for zfree function */
3900 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3901 if (r == Z_DATA_ERROR)
3902 z->msg = "oversubscribed dynamic bit lengths tree";
3903 else if (r == Z_BUF_ERROR)
3905 inflate_trees_free(*tb, z);
3906 z->msg = "incomplete dynamic bit lengths tree";
3913 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3914 uInt nl; /* number of literal/length codes */
3915 uInt nd; /* number of distance codes */
3916 uIntf *c; /* that many (total) code lengths */
3917 uIntf *bl; /* literal desired/actual bit depth */
3918 uIntf *bd; /* distance desired/actual bit depth */
3919 inflate_huft * FAR *tl; /* literal/length tree result */
3920 inflate_huft * FAR *td; /* distance tree result */
3921 z_stream *z; /* for zfree function */
3925 /* build literal/length tree */
3926 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3928 if (r == Z_DATA_ERROR)
3929 z->msg = "oversubscribed literal/length tree";
3930 else if (r == Z_BUF_ERROR)
3932 inflate_trees_free(*tl, z);
3933 z->msg = "incomplete literal/length tree";
3939 /* build distance tree */
3940 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3942 if (r == Z_DATA_ERROR)
3943 z->msg = "oversubscribed literal/length tree";
3944 else if (r == Z_BUF_ERROR) {
3945 #ifdef PKZIP_BUG_WORKAROUND
3949 inflate_trees_free(*td, z);
3950 z->msg = "incomplete literal/length tree";
3953 inflate_trees_free(*tl, z);
3963 /* build fixed tables only once--keep them here */
3964 local int fixed_lock = 0;
3965 local int fixed_built = 0;
3966 #define FIXEDH 530 /* number of hufts used by fixed tables */
3967 local uInt fixed_left = FIXEDH;
3968 local inflate_huft fixed_mem[FIXEDH];
3969 local uInt fixed_bl;
3970 local uInt fixed_bd;
3971 local inflate_huft *fixed_tl;
3972 local inflate_huft *fixed_td;
3975 local voidpf falloc(q, n, s)
3976 voidpf q; /* opaque pointer (not used) */
3977 uInt n; /* number of items */
3978 uInt s; /* size of item */
3980 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
3981 "inflate_trees falloc overflow");
3982 if (q) s++; /* to make some compilers happy */
3984 return (voidpf)(fixed_mem + fixed_left);
3988 local void ffree(q, p, n)
3993 Assert(0, "inflate_trees ffree called!");
3994 if (q) q = p; /* to make some compilers happy */
3998 int inflate_trees_fixed(bl, bd, tl, td)
3999 uIntf *bl; /* literal desired/actual bit depth */
4000 uIntf *bd; /* distance desired/actual bit depth */
4001 inflate_huft * FAR *tl; /* literal/length tree result */
4002 inflate_huft * FAR *td; /* distance tree result */
4004 /* build fixed tables if not built already--lock out other instances */
4005 while (++fixed_lock > 1)
4009 int k; /* temporary variable */
4010 unsigned c[288]; /* length list for huft_build */
4011 z_stream z; /* for falloc function */
4013 /* set up fake z_stream for memory routines */
4019 for (k = 0; k < 144; k++)
4021 for (; k < 256; k++)
4023 for (; k < 280; k++)
4025 for (; k < 288; k++)
4028 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4030 /* distance table */
4031 for (k = 0; k < 30; k++)
4034 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4048 int inflate_trees_free(t, z)
4049 inflate_huft *t; /* table to free */
4050 z_stream *z; /* for zfree function */
4051 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4052 list of the tables it made, with the links in a dummy first entry of
4055 register inflate_huft *p, *q;
4057 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4062 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4069 /* infcodes.c -- process literals and length/distance pairs
4070 * Copyright (C) 1995 Mark Adler
4071 * For conditions of distribution and use, see copyright notice in zlib.h
4074 /* simplify the use of the inflate_huft type with some defines */
4075 #define base more.Base
4076 #define next more.Next
4077 #define exop word.what.Exop
4078 #define bits word.what.Bits
4080 /* inflate codes private state */
4081 struct inflate_codes_state {
4084 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4085 START, /* x: set up for LEN */
4086 LEN, /* i: get length/literal/eob next */
4087 LENEXT, /* i: getting length extra (have base) */
4088 DIST, /* i: get distance next */
4089 DISTEXT, /* i: getting distance extra */
4090 COPY, /* o: copying bytes in window, waiting for space */
4091 LIT, /* o: got literal, waiting for output space */
4092 WASH, /* o: got eob, possibly still output waiting */
4093 END, /* x: got eob and all data flushed */
4094 BADCODE} /* x: got error */
4095 mode; /* current inflate_codes mode */
4097 /* mode dependent information */
4101 inflate_huft *tree; /* pointer into tree */
4102 uInt need; /* bits needed */
4103 } code; /* if LEN or DIST, where in tree */
4104 uInt lit; /* if LIT, literal */
4106 uInt get; /* bits to get for extra */
4107 uInt dist; /* distance back to copy from */
4108 } copy; /* if EXT or COPY, where and how much */
4109 } sub; /* submode */
4111 /* mode independent information */
4112 Byte lbits; /* ltree bits decoded per branch */
4113 Byte dbits; /* dtree bits decoder per branch */
4114 inflate_huft *ltree; /* literal/length/eob tree */
4115 inflate_huft *dtree; /* distance tree */
4120 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4122 inflate_huft *tl, *td;
4125 inflate_codes_statef *c;
4127 if ((c = (inflate_codes_statef *)
4128 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4131 c->lbits = (Byte)bl;
4132 c->dbits = (Byte)bd;
4135 Tracev((stderr, "inflate: codes new\n"));
4141 int inflate_codes(s, z, r)
4142 inflate_blocks_statef *s;
4146 uInt j; /* temporary storage */
4147 inflate_huft *t; /* temporary pointer */
4148 uInt e; /* extra bits or operation */
4149 uLong b; /* bit buffer */
4150 uInt k; /* bits in bit buffer */
4151 Bytef *p; /* input data pointer */
4152 uInt n; /* bytes available there */
4153 Bytef *q; /* output window write pointer */
4154 uInt m; /* bytes to end of window or read pointer */
4155 Bytef *f; /* pointer to copy strings from */
4156 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4158 /* copy input/output information to locals (UPDATE macro restores) */
4161 /* process input and output based on current state */
4162 while (1) switch (c->mode)
4163 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4164 case START: /* x: set up for LEN */
4166 if (m >= 258 && n >= 10)
4169 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4173 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4178 c->sub.code.need = c->lbits;
4179 c->sub.code.tree = c->ltree;
4181 case LEN: /* i: get length/literal/eob next */
4182 j = c->sub.code.need;
4184 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4186 e = (uInt)(t->exop);
4187 if (e == 0) /* literal */
4189 c->sub.lit = t->base;
4190 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4191 "inflate: literal '%c'\n" :
4192 "inflate: literal 0x%02x\n", t->base));
4196 if (e & 16) /* length */
4198 c->sub.copy.get = e & 15;
4203 if ((e & 64) == 0) /* next table */
4205 c->sub.code.need = e;
4206 c->sub.code.tree = t->next;
4209 if (e & 32) /* end of block */
4211 Tracevv((stderr, "inflate: end of block\n"));
4215 c->mode = BADCODE; /* invalid code */
4216 z->msg = "invalid literal/length code";
4219 case LENEXT: /* i: getting length extra (have base) */
4220 j = c->sub.copy.get;
4222 c->len += (uInt)b & inflate_mask[j];
4224 c->sub.code.need = c->dbits;
4225 c->sub.code.tree = c->dtree;
4226 Tracevv((stderr, "inflate: length %u\n", c->len));
4228 case DIST: /* i: get distance next */
4229 j = c->sub.code.need;
4231 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4233 e = (uInt)(t->exop);
4234 if (e & 16) /* distance */
4236 c->sub.copy.get = e & 15;
4237 c->sub.copy.dist = t->base;
4241 if ((e & 64) == 0) /* next table */
4243 c->sub.code.need = e;
4244 c->sub.code.tree = t->next;
4247 c->mode = BADCODE; /* invalid code */
4248 z->msg = "invalid distance code";
4251 case DISTEXT: /* i: getting distance extra */
4252 j = c->sub.copy.get;
4254 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4256 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4258 case COPY: /* o: copying bytes in window, waiting for space */
4259 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4260 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4261 s->end - (c->sub.copy.dist - (q - s->window)) :
4262 q - c->sub.copy.dist;
4264 f = q - c->sub.copy.dist;
4265 if ((uInt)(q - s->window) < c->sub.copy.dist)
4266 f = s->end - (c->sub.copy.dist - (q - s->window));
4278 case LIT: /* o: got literal, waiting for output space */
4283 case WASH: /* o: got eob, possibly more output */
4285 if (s->read != s->write)
4291 case BADCODE: /* x: got error */
4301 void inflate_codes_free(c, z)
4302 inflate_codes_statef *c;
4305 ZFREE(z, c, sizeof(struct inflate_codes_state));
4306 Tracev((stderr, "inflate: codes free\n"));
4310 /* inflate_util.c -- data and routines common to blocks and codes
4311 * Copyright (C) 1995 Mark Adler
4312 * For conditions of distribution and use, see copyright notice in zlib.h
4315 /* copy as much as possible from the sliding window to the output area */
4316 int inflate_flush(s, z, r)
4317 inflate_blocks_statef *s;
4324 /* local copies of source and destination pointers */
4328 /* compute number of bytes to copy as far as end of window */
4329 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4330 if (n > z->avail_out) n = z->avail_out;
4331 if (n && r == Z_BUF_ERROR) r = Z_OK;
4333 /* update counters */
4337 /* update check information */
4338 if (s->checkfn != Z_NULL)
4339 s->check = (*s->checkfn)(s->check, q, n);
4341 /* copy as far as end of window */
4348 /* see if more to copy at beginning of window */
4353 if (s->write == s->end)
4354 s->write = s->window;
4356 /* compute bytes to copy */
4357 n = (uInt)(s->write - q);
4358 if (n > z->avail_out) n = z->avail_out;
4359 if (n && r == Z_BUF_ERROR) r = Z_OK;
4361 /* update counters */
4365 /* update check information */
4366 if (s->checkfn != Z_NULL)
4367 s->check = (*s->checkfn)(s->check, q, n);
4377 /* update pointers */
4387 /* inffast.c -- process literals and length/distance pairs fast
4388 * Copyright (C) 1995 Mark Adler
4389 * For conditions of distribution and use, see copyright notice in zlib.h
4392 /* simplify the use of the inflate_huft type with some defines */
4393 #define base more.Base
4394 #define next more.Next
4395 #define exop word.what.Exop
4396 #define bits word.what.Bits
4398 /* macros for bit input with no checking and for returning unused bytes */
4399 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4400 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4402 /* Called with number of bytes left to write in window at least 258
4403 (the maximum string length) and number of input bytes available
4404 at least ten. The ten bytes are six bytes for the longest length/
4405 distance pair plus four bytes for overloading the bit buffer. */
4407 int inflate_fast(bl, bd, tl, td, s, z)
4409 inflate_huft *tl, *td;
4410 inflate_blocks_statef *s;
4413 inflate_huft *t; /* temporary pointer */
4414 uInt e; /* extra bits or operation */
4415 uLong b; /* bit buffer */
4416 uInt k; /* bits in bit buffer */
4417 Bytef *p; /* input data pointer */
4418 uInt n; /* bytes available there */
4419 Bytef *q; /* output window write pointer */
4420 uInt m; /* bytes to end of window or read pointer */
4421 uInt ml; /* mask for literal/length tree */
4422 uInt md; /* mask for distance tree */
4423 uInt c; /* bytes to copy */
4424 uInt d; /* distance back to copy from */
4425 Bytef *r; /* copy source pointer */
4427 /* load input, output, bit values */
4430 /* initialize masks */
4431 ml = inflate_mask[bl];
4432 md = inflate_mask[bd];
4434 /* do until not enough input or output space for fast loop */
4435 do { /* assume called with m >= 258 && n >= 10 */
4436 /* get literal/length code */
4437 GRABBITS(20) /* max bits for literal/length code */
4438 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4441 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4442 "inflate: * literal '%c'\n" :
4443 "inflate: * literal 0x%02x\n", t->base));
4444 *q++ = (Byte)t->base;
4452 /* get extra bits for length */
4454 c = t->base + ((uInt)b & inflate_mask[e]);
4456 Tracevv((stderr, "inflate: * length %u\n", c));
4458 /* decode distance base of block to copy */
4459 GRABBITS(15); /* max bits for distance code */
4460 e = (t = td + ((uInt)b & md))->exop;
4465 /* get extra bits to add to distance base */
4467 GRABBITS(e) /* get extra bits (up to 13) */
4468 d = t->base + ((uInt)b & inflate_mask[e]);
4470 Tracevv((stderr, "inflate: * distance %u\n", d));
4474 if ((uInt)(q - s->window) >= d) /* offset before dest */
4477 *q++ = *r++; c--; /* minimum count is three, */
4478 *q++ = *r++; c--; /* so unroll loop a little */
4480 else /* else offset after destination */
4482 e = d - (q - s->window); /* bytes from offset to end */
4483 r = s->end - e; /* pointer to offset */
4484 if (c > e) /* if source crosses, */
4486 c -= e; /* copy to end of window */
4490 r = s->window; /* copy rest from start of window */
4493 do { /* copy all or what's left */
4498 else if ((e & 64) == 0)
4499 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4502 z->msg = "invalid distance code";
4505 return Z_DATA_ERROR;
4512 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4515 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4516 "inflate: * literal '%c'\n" :
4517 "inflate: * literal 0x%02x\n", t->base));
4518 *q++ = (Byte)t->base;
4525 Tracevv((stderr, "inflate: * end of block\n"));
4528 return Z_STREAM_END;
4532 z->msg = "invalid literal/length code";
4535 return Z_DATA_ERROR;
4538 } while (m >= 258 && n >= 10);
4540 /* not enough input or output--restore pointers and return */
4548 /* zutil.c -- target dependent utility functions for the compression library
4549 * Copyright (C) 1995 Jean-loup Gailly.
4550 * For conditions of distribution and use, see copyright notice in zlib.h
4553 /* $Id: zlib.c,v 1.1 1996/06/11 06:41:38 paulus Exp $ */
4555 char *zlib_version = ZLIB_VERSION;
4557 char *z_errmsg[] = {
4558 "stream end", /* Z_STREAM_END 1 */
4560 "file error", /* Z_ERRNO (-1) */
4561 "stream error", /* Z_STREAM_ERROR (-2) */
4562 "data error", /* Z_DATA_ERROR (-3) */
4563 "insufficient memory", /* Z_MEM_ERROR (-4) */
4564 "buffer error", /* Z_BUF_ERROR (-5) */
4569 /* adler32.c -- compute the Adler-32 checksum of a data stream
4570 * Copyright (C) 1995 Mark Adler
4571 * For conditions of distribution and use, see copyright notice in zlib.h
4574 /* $Id: zlib.c,v 1.1 1996/06/11 06:41:38 paulus Exp $ */
4576 #define BASE 65521L /* largest prime smaller than 65536 */
4578 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4580 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4581 #define DO2(buf) DO1(buf); DO1(buf);
4582 #define DO4(buf) DO2(buf); DO2(buf);
4583 #define DO8(buf) DO4(buf); DO4(buf);
4584 #define DO16(buf) DO8(buf); DO8(buf);
4586 /* ========================================================================= */
4587 uLong adler32(adler, buf, len)
4592 unsigned long s1 = adler & 0xffff;
4593 unsigned long s2 = (adler >> 16) & 0xffff;
4596 if (buf == Z_NULL) return 1L;
4599 k = len < NMAX ? len : NMAX;
4611 return (s2 << 16) | s1;