2 * This file is derived from various .h and .c files from the zlib-0.95
3 * distribution by Jean-loup Gailly and Mark Adler, with some additions
4 * by Paul Mackerras to aid in implementing Deflate compression and
5 * decompression for PPP packets. See zlib.h for conditions of
6 * distribution and use.
8 * Changes that have been made include:
9 * - changed functions not used outside this file to "local"
10 * - added minCompression parameter to deflateInit2
11 * - added Z_PACKET_FLUSH (see zlib.h for details)
12 * - added inflateIncomp
19 /* zutil.h -- internal interface and configuration of the compression library
20 * Copyright (C) 1995 Jean-loup Gailly.
21 * For conditions of distribution and use, see copyright notice in zlib.h
24 /* WARNING: this file should *not* be used by applications. It is
25 part of the implementation of the compression library and is
26 subject to change. Applications should only use zlib.h.
29 /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */
38 /* compile with -Dlocal if your debugger can't find static symbols */
42 typedef unsigned char uch;
44 typedef unsigned short ush;
46 typedef unsigned int ulg;
48 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
50 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
51 /* To be used only when the state is known to be valid */
54 #define NULL ((void *) 0)
57 /* common constants */
62 # define DEF_WBITS MAX_WBITS
64 /* default windowBits for decompression. MAX_WBITS is for compression only */
66 #if MAX_MEM_LEVEL >= 8
67 # define DEF_MEM_LEVEL 8
69 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
71 /* default memLevel */
73 #define STORED_BLOCK 0
74 #define STATIC_TREES 1
76 /* The three kinds of block type */
80 /* The minimum and maximum match lengths */
84 #if defined(KERNEL) || defined(_KERNEL)
85 # define zmemcpy(d, s, n) bcopy((s), (d), (n))
86 # define zmemzero bzero
88 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
92 # define zmemcpy memcpy
93 # define zmemzero(dest, len) memset(dest, 0, len)
95 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
96 extern void zmemzero OF((Bytef* dest, uInt len));
100 /* Diagnostic functions */
106 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
107 # define Trace(x) fprintf x
108 # define Tracev(x) {if (verbose) fprintf x ;}
109 # define Tracevv(x) {if (verbose>1) fprintf x ;}
110 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
111 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
113 # define Assert(cond,msg)
118 # define Tracecv(c,x)
122 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
124 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
125 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
127 #define ZALLOC(strm, items, size) \
128 (*((strm)->zalloc))((strm)->opaque, (items), (size))
129 #define ZFREE(strm, addr, size) \
130 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
131 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
133 /* deflate.h -- internal compression state
134 * Copyright (C) 1995 Jean-loup Gailly
135 * For conditions of distribution and use, see copyright notice in zlib.h
138 /* WARNING: this file should *not* be used by applications. It is
139 part of the implementation of the compression library and is
140 subject to change. Applications should only use zlib.h.
145 /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */
147 /* ===========================================================================
148 * Internal compression state.
156 #define LENGTH_CODES 29
157 /* number of length codes, not counting the special END_BLOCK code */
160 /* number of literal bytes 0..255 */
162 #define L_CODES (LITERALS+1+LENGTH_CODES)
163 /* number of Literal or Length codes, including the END_BLOCK code */
166 /* number of distance codes */
169 /* number of codes used to transfer the bit lengths */
171 #define HEAP_SIZE (2*L_CODES+1)
172 /* maximum heap size */
175 /* All codes must not exceed MAX_BITS bits */
177 #define INIT_STATE 42
178 #define BUSY_STATE 113
179 #define FLUSH_STATE 124
180 #define FINISH_STATE 666
184 /* Data structure describing a single value and its code string. */
185 typedef struct ct_data_s {
187 ush freq; /* frequency count */
188 ush code; /* bit string */
191 ush dad; /* father node in Huffman tree */
192 ush len; /* length of bit string */
201 typedef struct static_tree_desc_s static_tree_desc;
203 typedef struct tree_desc_s {
204 ct_data *dyn_tree; /* the dynamic tree */
205 int max_code; /* largest code with non zero frequency */
206 static_tree_desc *stat_desc; /* the corresponding static tree */
210 typedef Pos FAR Posf;
211 typedef unsigned IPos;
213 /* A Pos is an index in the character window. We use short instead of int to
214 * save space in the various tables. IPos is used only for parameter passing.
217 typedef struct deflate_state {
218 z_stream *strm; /* pointer back to this zlib stream */
219 int status; /* as the name implies */
220 Bytef *pending_buf; /* output still pending */
221 Bytef *pending_out; /* next pending byte to output to the stream */
222 int pending; /* nb of bytes in the pending buffer */
223 uLong adler; /* adler32 of uncompressed data */
224 int noheader; /* suppress zlib header and adler32 */
225 Byte data_type; /* UNKNOWN, BINARY or ASCII */
226 Byte method; /* STORED (for zip only) or DEFLATED */
227 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */
229 /* used by deflate.c: */
231 uInt w_size; /* LZ77 window size (32K by default) */
232 uInt w_bits; /* log2(w_size) (8..16) */
233 uInt w_mask; /* w_size - 1 */
236 /* Sliding window. Input bytes are read into the second half of the window,
237 * and move to the first half later to keep a dictionary of at least wSize
238 * bytes. With this organization, matches are limited to a distance of
239 * wSize-MAX_MATCH bytes, but this ensures that IO is always
240 * performed with a length multiple of the block size. Also, it limits
241 * the window size to 64K, which is quite useful on MSDOS.
242 * To do: use the user input buffer as sliding window.
246 /* Actual size of window: 2*wSize, except when the user input buffer
247 * is directly used as sliding window.
251 /* Link to older string with same hash index. To limit the size of this
252 * array to 64K, this link is maintained only for the last 32K strings.
253 * An index in this array is thus a window index modulo 32K.
256 Posf *head; /* Heads of the hash chains or NIL. */
258 uInt ins_h; /* hash index of string to be inserted */
259 uInt hash_size; /* number of elements in hash table */
260 uInt hash_bits; /* log2(hash_size) */
261 uInt hash_mask; /* hash_size-1 */
264 /* Number of bits by which ins_h must be shifted at each input
265 * step. It must be such that after MIN_MATCH steps, the oldest
266 * byte no longer takes part in the hash key, that is:
267 * hash_shift * MIN_MATCH >= hash_bits
271 /* Window position at the beginning of the current output block. Gets
272 * negative when the window is moved backwards.
275 uInt match_length; /* length of best match */
276 IPos prev_match; /* previous match */
277 int match_available; /* set if previous match exists */
278 uInt strstart; /* start of string to insert */
279 uInt match_start; /* start of matching string */
280 uInt lookahead; /* number of valid bytes ahead in window */
283 /* Length of the best match at previous step. Matches not greater than this
284 * are discarded. This is used in the lazy match evaluation.
287 uInt max_chain_length;
288 /* To speed up deflation, hash chains are never searched beyond this
289 * length. A higher limit improves compression ratio but degrades the
294 /* Attempt to find a better match only when the current match is strictly
295 * smaller than this value. This mechanism is used only for compression
298 # define max_insert_length max_lazy_match
299 /* Insert new strings in the hash table only if the match length is not
300 * greater than this length. This saves time but degrades compression.
301 * max_insert_length is used only for compression levels <= 3.
304 int level; /* compression level (1..9) */
305 int strategy; /* favor or force Huffman coding*/
308 /* Use a faster search when the previous match is longer than this */
310 int nice_match; /* Stop searching when current match exceeds this */
312 /* used by trees.c: */
313 /* Didn't use ct_data typedef below to supress compiler warning */
314 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
315 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
316 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
318 struct tree_desc_s l_desc; /* desc. for literal tree */
319 struct tree_desc_s d_desc; /* desc. for distance tree */
320 struct tree_desc_s bl_desc; /* desc. for bit length tree */
322 ush bl_count[MAX_BITS+1];
323 /* number of codes at each bit length for an optimal tree */
325 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
326 int heap_len; /* number of elements in the heap */
327 int heap_max; /* element of largest frequency */
328 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
329 * The same heap array is used to build all trees.
332 uch depth[2*L_CODES+1];
333 /* Depth of each subtree used as tie breaker for trees of equal frequency
336 uchf *l_buf; /* buffer for literals or lengths */
339 /* Size of match buffer for literals/lengths. There are 4 reasons for
340 * limiting lit_bufsize to 64K:
341 * - frequencies can be kept in 16 bit counters
342 * - if compression is not successful for the first block, all input
343 * data is still in the window so we can still emit a stored block even
344 * when input comes from standard input. (This can also be done for
345 * all blocks if lit_bufsize is not greater than 32K.)
346 * - if compression is not successful for a file smaller than 64K, we can
347 * even emit a stored file instead of a stored block (saving 5 bytes).
348 * This is applicable only for zip (not gzip or zlib).
349 * - creating new Huffman trees less frequently may not provide fast
350 * adaptation to changes in the input data statistics. (Take for
351 * example a binary file with poorly compressible code followed by
352 * a highly compressible string table.) Smaller buffer sizes give
353 * fast adaptation but have of course the overhead of transmitting
354 * trees more frequently.
355 * - I can't count above 4
358 uInt last_lit; /* running index in l_buf */
361 /* Buffer for distances. To simplify the code, d_buf and l_buf have
362 * the same number of elements. To use different lengths, an extra flag
363 * array would be necessary.
366 ulg opt_len; /* bit length of current block with optimal trees */
367 ulg static_len; /* bit length of current block with static trees */
368 ulg compressed_len; /* total bit length of compressed file */
369 uInt matches; /* number of string matches in current block */
370 int last_eob_len; /* bit length of EOB code for last block */
373 ulg bits_sent; /* bit length of the compressed data */
377 /* Output buffer. bits are inserted starting at the bottom (least
381 /* Number of valid bits in bi_buf. All bits above the last valid bit
385 uInt blocks_in_packet;
386 /* Number of blocks produced since the last time Z_PACKET_FLUSH
392 /* Output a byte on the stream.
393 * IN assertion: there is enough room in pending_buf.
395 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
398 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
399 /* Minimum amount of lookahead, except at the end of the input file.
400 * See deflate.c for comments about the MIN_MATCH+1.
403 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
404 /* In order to simplify the code, particularly on 16 bit machines, match
405 * distances are limited to MAX_DIST instead of WSIZE.
409 local void ct_init OF((deflate_state *s));
410 local int ct_tally OF((deflate_state *s, int dist, int lc));
411 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
413 local void ct_align OF((deflate_state *s));
414 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
416 local void ct_stored_type_only OF((deflate_state *s));
420 /* deflate.c -- compress data using the deflation algorithm
421 * Copyright (C) 1995 Jean-loup Gailly.
422 * For conditions of distribution and use, see copyright notice in zlib.h
428 * The "deflation" process depends on being able to identify portions
429 * of the input text which are identical to earlier input (within a
430 * sliding window trailing behind the input currently being processed).
432 * The most straightforward technique turns out to be the fastest for
433 * most input files: try all possible matches and select the longest.
434 * The key feature of this algorithm is that insertions into the string
435 * dictionary are very simple and thus fast, and deletions are avoided
436 * completely. Insertions are performed at each input character, whereas
437 * string matches are performed only when the previous match ends. So it
438 * is preferable to spend more time in matches to allow very fast string
439 * insertions and avoid deletions. The matching algorithm for small
440 * strings is inspired from that of Rabin & Karp. A brute force approach
441 * is used to find longer strings when a small match has been found.
442 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
443 * (by Leonid Broukhis).
444 * A previous version of this file used a more sophisticated algorithm
445 * (by Fiala and Greene) which is guaranteed to run in linear amortized
446 * time, but has a larger average cost, uses more memory and is patented.
447 * However the F&G algorithm may be faster for some highly redundant
448 * files if the parameter max_chain_length (described below) is too large.
452 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
453 * I found it in 'freeze' written by Leonid Broukhis.
454 * Thanks to many people for bug reports and testing.
458 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
459 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
461 * A description of the Rabin and Karp algorithm is given in the book
462 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
464 * Fiala,E.R., and Greene,D.H.
465 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
469 /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */
471 local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
473 If you use the zlib library in a product, an acknowledgment is welcome
474 in the documentation of your product. If for some reason you cannot
475 include such an acknowledgment, I would appreciate that you keep this
476 copyright string in the executable of your product.
480 /* Tail of hash chains */
483 # define TOO_FAR 4096
485 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
487 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
488 /* Minimum amount of lookahead, except at the end of the input file.
489 * See deflate.c for comments about the MIN_MATCH+1.
492 /* Values for max_lazy_match, good_match and max_chain_length, depending on
493 * the desired pack level (0..9). The values given below have been tuned to
494 * exclude worst case performance for pathological files. Better values may be
495 * found for specific files.
498 typedef struct config_s {
499 ush good_length; /* reduce lazy search above this match length */
500 ush max_lazy; /* do not perform lazy search above this match length */
501 ush nice_length; /* quit search above this match length */
505 local config configuration_table[10] = {
506 /* good lazy nice chain */
507 /* 0 */ {0, 0, 0, 0}, /* store only */
508 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
509 /* 2 */ {4, 5, 16, 8},
510 /* 3 */ {4, 6, 32, 32},
512 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
513 /* 5 */ {8, 16, 32, 32},
514 /* 6 */ {8, 16, 128, 128},
515 /* 7 */ {8, 32, 128, 256},
516 /* 8 */ {32, 128, 258, 1024},
517 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
519 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
520 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
525 /* result of memcmp for equal strings */
527 /* ===========================================================================
528 * Prototypes for local functions.
531 local void fill_window OF((deflate_state *s));
532 local int deflate_fast OF((deflate_state *s, int flush));
533 local int deflate_slow OF((deflate_state *s, int flush));
534 local void lm_init OF((deflate_state *s));
535 local int longest_match OF((deflate_state *s, IPos cur_match));
536 local void putShortMSB OF((deflate_state *s, uInt b));
537 local void flush_pending OF((z_stream *strm));
538 local int read_buf OF((z_stream *strm, charf *buf, unsigned size));
540 void match_init OF((void)); /* asm code initialization */
544 local void check_match OF((deflate_state *s, IPos start, IPos match,
549 /* ===========================================================================
550 * Update a hash value with the given input byte
551 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
552 * input characters, so that a running hash key can be computed from the
553 * previous key instead of complete recalculation each time.
555 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
558 /* ===========================================================================
559 * Insert string str in the dictionary and set match_head to the previous head
560 * of the hash chain (the most recent string with same hash key). Return
561 * the previous length of the hash chain.
562 * IN assertion: all calls to to INSERT_STRING are made with consecutive
563 * input characters and the first MIN_MATCH bytes of str are valid
564 * (except for the last MIN_MATCH-1 bytes of the input file).
566 #define INSERT_STRING(s, str, match_head) \
567 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
568 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
569 s->head[s->ins_h] = (str))
571 /* ===========================================================================
572 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
573 * prev[] will be initialized on the fly.
575 #define CLEAR_HASH(s) \
576 s->head[s->hash_size-1] = NIL; \
577 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
579 /* ========================================================================= */
580 int deflateInit (strm, level)
584 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
586 /* To do: ignore strm->next_in if we use it as window */
589 /* ========================================================================= */
590 int deflateInit2 (strm, level, method, windowBits, memLevel,
591 strategy, minCompression)
603 if (strm == Z_NULL) return Z_STREAM_ERROR;
606 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
607 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
609 if (level == Z_DEFAULT_COMPRESSION) level = 6;
611 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
613 windowBits = -windowBits;
615 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
616 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
617 return Z_STREAM_ERROR;
619 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
620 if (s == Z_NULL) return Z_MEM_ERROR;
621 strm->state = (struct internal_state FAR *)s;
624 s->noheader = noheader;
625 s->w_bits = windowBits;
626 s->w_size = 1 << s->w_bits;
627 s->w_mask = s->w_size - 1;
629 s->hash_bits = memLevel + 7;
630 s->hash_size = 1 << s->hash_bits;
631 s->hash_mask = s->hash_size - 1;
632 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
634 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
635 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
636 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
638 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
640 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
642 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
643 s->pending_buf == Z_NULL) {
644 strm->msg = z_errmsg[1-Z_MEM_ERROR];
648 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
649 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
650 /* We overlay pending_buf and d_buf+l_buf. This works since the average
651 * output size for (length,distance) codes is <= 32 bits (worst case
656 s->strategy = strategy;
657 s->method = (Byte)method;
658 s->minCompr = minCompression;
659 s->blocks_in_packet = 0;
661 return deflateReset(strm);
664 /* ========================================================================= */
665 int deflateReset (strm)
670 if (strm == Z_NULL || strm->state == Z_NULL ||
671 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
673 strm->total_in = strm->total_out = 0;
674 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
675 strm->data_type = Z_UNKNOWN;
677 s = (deflate_state *)strm->state;
679 s->pending_out = s->pending_buf;
681 if (s->noheader < 0) {
682 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
684 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
693 /* =========================================================================
694 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
695 * IN assertion: the stream state is correct and there is enough room in
698 local void putShortMSB (s, b)
702 put_byte(s, (Byte)(b >> 8));
703 put_byte(s, (Byte)(b & 0xff));
706 /* =========================================================================
707 * Flush as much pending output as possible.
709 local void flush_pending(strm)
712 deflate_state *state = (deflate_state *) strm->state;
713 unsigned len = state->pending;
715 if (len > strm->avail_out) len = strm->avail_out;
716 if (len == 0) return;
718 if (strm->next_out != NULL) {
719 zmemcpy(strm->next_out, state->pending_out, len);
720 strm->next_out += len;
722 state->pending_out += len;
723 strm->total_out += len;
724 strm->avail_out -= len;
725 state->pending -= len;
726 if (state->pending == 0) {
727 state->pending_out = state->pending_buf;
731 /* ========================================================================= */
732 int deflate (strm, flush)
736 deflate_state *state = (deflate_state *) strm->state;
738 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
740 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
741 ERR_RETURN(strm, Z_STREAM_ERROR);
743 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
745 state->strm = strm; /* just in case */
747 /* Write the zlib header */
748 if (state->status == INIT_STATE) {
750 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
751 uInt level_flags = (state->level-1) >> 1;
753 if (level_flags > 3) level_flags = 3;
754 header |= (level_flags << 6);
755 header += 31 - (header % 31);
757 state->status = BUSY_STATE;
758 putShortMSB(state, header);
761 /* Flush as much pending output as possible */
762 if (state->pending != 0) {
764 if (strm->avail_out == 0) return Z_OK;
767 /* If we came back in here to get the last output from
768 * a previous flush, we're done for now.
770 if (state->status == FLUSH_STATE) {
771 state->status = BUSY_STATE;
772 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
776 /* User must not provide more input after the first FINISH: */
777 if (state->status == FINISH_STATE && strm->avail_in != 0) {
778 ERR_RETURN(strm, Z_BUF_ERROR);
781 /* Start a new block or continue the current one.
783 if (strm->avail_in != 0 || state->lookahead != 0 ||
784 (flush == Z_FINISH && state->status != FINISH_STATE)) {
787 if (flush == Z_FINISH) {
788 state->status = FINISH_STATE;
790 if (state->level <= 3) {
791 quit = deflate_fast(state, flush);
793 quit = deflate_slow(state, flush);
795 if (quit || strm->avail_out == 0)
797 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
798 * of deflate should use the same flush parameter to make sure
799 * that the flush is complete. So we don't have to output an
800 * empty block here, this will be done at next call. This also
801 * ensures that for a very small output buffer, we emit at most
806 /* If a flush was requested, we have a little more to output now. */
807 if (flush != Z_NO_FLUSH && flush != Z_FINISH
808 && state->status != FINISH_STATE) {
810 case Z_PARTIAL_FLUSH:
814 /* Output just the 3-bit `stored' block type value,
815 but not a zero length. */
816 ct_stored_type_only(state);
819 ct_stored_block(state, (char*)0, 0L, 0);
820 /* For a full flush, this empty block will be recognized
821 * as a special marker by inflate_sync().
823 if (flush == Z_FULL_FLUSH) {
824 CLEAR_HASH(state); /* forget history */
828 if (strm->avail_out == 0) {
829 /* We'll have to come back to get the rest of the output;
830 * this ensures we don't output a second zero-length stored
831 * block (or whatever).
833 state->status = FLUSH_STATE;
838 Assert(strm->avail_out > 0, "bug2");
840 if (flush != Z_FINISH) return Z_OK;
841 if (state->noheader) return Z_STREAM_END;
843 /* Write the zlib trailer (adler32) */
844 putShortMSB(state, (uInt)(state->adler >> 16));
845 putShortMSB(state, (uInt)(state->adler & 0xffff));
847 /* If avail_out is zero, the application will call deflate again
850 state->noheader = -1; /* write the trailer only once! */
851 return state->pending != 0 ? Z_OK : Z_STREAM_END;
854 /* ========================================================================= */
855 int deflateEnd (strm)
858 deflate_state *state = (deflate_state *) strm->state;
860 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
862 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
863 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
864 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
865 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
867 ZFREE(strm, state, sizeof(deflate_state));
868 strm->state = Z_NULL;
873 /* ===========================================================================
874 * Read a new buffer from the current input stream, update the adler32
875 * and total number of bytes read.
877 local int read_buf(strm, buf, size)
882 unsigned len = strm->avail_in;
883 deflate_state *state = (deflate_state *) strm->state;
885 if (len > size) len = size;
886 if (len == 0) return 0;
888 strm->avail_in -= len;
890 if (!state->noheader) {
891 state->adler = adler32(state->adler, strm->next_in, len);
893 zmemcpy(buf, strm->next_in, len);
894 strm->next_in += len;
895 strm->total_in += len;
900 /* ===========================================================================
901 * Initialize the "longest match" routines for a new zlib stream
903 local void lm_init (s)
906 s->window_size = (ulg)2L*s->w_size;
910 /* Set the default configuration parameters:
912 s->max_lazy_match = configuration_table[s->level].max_lazy;
913 s->good_match = configuration_table[s->level].good_length;
914 s->nice_match = configuration_table[s->level].nice_length;
915 s->max_chain_length = configuration_table[s->level].max_chain;
920 s->match_length = MIN_MATCH-1;
921 s->match_available = 0;
924 match_init(); /* initialize the asm code */
928 /* ===========================================================================
929 * Set match_start to the longest match starting at the given string and
930 * return its length. Matches shorter or equal to prev_length are discarded,
931 * in which case the result is equal to prev_length and match_start is
933 * IN assertions: cur_match is the head of the hash chain for the current
934 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
937 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
938 * match.S. The code will be functionally equivalent.
940 local int longest_match(s, cur_match)
942 IPos cur_match; /* current match */
944 unsigned chain_length = s->max_chain_length;/* max hash chain length */
945 register Bytef *scan = s->window + s->strstart; /* current string */
946 register Bytef *match; /* matched string */
947 register int len; /* length of current match */
948 int best_len = s->prev_length; /* best match length so far */
949 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
950 s->strstart - (IPos)MAX_DIST(s) : NIL;
951 /* Stop when cur_match becomes <= limit. To simplify the code,
952 * we prevent matches with the string of window index 0.
954 Posf *prev = s->prev;
955 uInt wmask = s->w_mask;
958 /* Compare two bytes at a time. Note: this is not always beneficial.
959 * Try with and without -DUNALIGNED_OK to check.
961 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
962 register ush scan_start = *(ushf*)scan;
963 register ush scan_end = *(ushf*)(scan+best_len-1);
965 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
966 register Byte scan_end1 = scan[best_len-1];
967 register Byte scan_end = scan[best_len];
970 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
971 * It is easy to get rid of this optimization if necessary.
973 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
975 /* Do not waste too much time if we already have a good match: */
976 if (s->prev_length >= s->good_match) {
979 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
982 Assert(cur_match < s->strstart, "no future");
983 match = s->window + cur_match;
985 /* Skip to next match if the match length cannot increase
986 * or if the match length is less than 2:
988 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
989 /* This code assumes sizeof(unsigned short) == 2. Do not use
990 * UNALIGNED_OK if your compiler uses a different size.
992 if (*(ushf*)(match+best_len-1) != scan_end ||
993 *(ushf*)match != scan_start) continue;
995 /* It is not necessary to compare scan[2] and match[2] since they are
996 * always equal when the other bytes match, given that the hash keys
997 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
998 * strstart+3, +5, ... up to strstart+257. We check for insufficient
999 * lookahead only every 4th comparison; the 128th check will be made
1000 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1001 * necessary to put more guard bytes at the end of the window, or
1002 * to check more often for insufficient lookahead.
1004 Assert(scan[2] == match[2], "scan[2]?");
1007 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1008 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1009 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1010 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1012 /* The funny "do {}" generates better code on most compilers */
1014 /* Here, scan <= window+strstart+257 */
1015 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1016 if (*scan == *match) scan++;
1018 len = (MAX_MATCH - 1) - (int)(strend-scan);
1019 scan = strend - (MAX_MATCH-1);
1021 #else /* UNALIGNED_OK */
1023 if (match[best_len] != scan_end ||
1024 match[best_len-1] != scan_end1 ||
1026 *++match != scan[1]) continue;
1028 /* The check at best_len-1 can be removed because it will be made
1029 * again later. (This heuristic is not always a win.)
1030 * It is not necessary to compare scan[2] and match[2] since they
1031 * are always equal when the other bytes match, given that
1032 * the hash keys are equal and that HASH_BITS >= 8.
1035 Assert(*scan == *match, "match[2]?");
1037 /* We check for insufficient lookahead only every 8th comparison;
1038 * the 256th check will be made at strstart+258.
1041 } while (*++scan == *++match && *++scan == *++match &&
1042 *++scan == *++match && *++scan == *++match &&
1043 *++scan == *++match && *++scan == *++match &&
1044 *++scan == *++match && *++scan == *++match &&
1047 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1049 len = MAX_MATCH - (int)(strend - scan);
1050 scan = strend - MAX_MATCH;
1052 #endif /* UNALIGNED_OK */
1054 if (len > best_len) {
1055 s->match_start = cur_match;
1057 if (len >= s->nice_match) break;
1059 scan_end = *(ushf*)(scan+best_len-1);
1061 scan_end1 = scan[best_len-1];
1062 scan_end = scan[best_len];
1065 } while ((cur_match = prev[cur_match & wmask]) > limit
1066 && --chain_length != 0);
1073 /* ===========================================================================
1074 * Check that the match at match_start is indeed a match.
1076 local void check_match(s, start, match, length)
1081 /* check that the match is indeed a match */
1082 if (memcmp((charf *)s->window + match,
1083 (charf *)s->window + start, length) != EQUAL) {
1085 " start %u, match %u, length %d\n",
1086 start, match, length);
1087 do { fprintf(stderr, "%c%c", s->window[match++],
1088 s->window[start++]); } while (--length != 0);
1089 z_error("invalid match");
1092 fprintf(stderr,"\\[%d,%d]", start-match, length);
1093 do { putc(s->window[start++], stderr); } while (--length != 0);
1097 # define check_match(s, start, match, length)
1100 /* ===========================================================================
1101 * Fill the window when the lookahead becomes insufficient.
1102 * Updates strstart and lookahead.
1104 * IN assertion: lookahead < MIN_LOOKAHEAD
1105 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1106 * At least one byte has been read, or avail_in == 0; reads are
1107 * performed for at least two bytes (required for the zip translate_eol
1108 * option -- not supported here).
1110 local void fill_window(s)
1113 register unsigned n, m;
1115 unsigned more; /* Amount of free space at the end of the window. */
1116 uInt wsize = s->w_size;
1119 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1121 /* Deal with !@#$% 64K limit: */
1122 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1124 } else if (more == (unsigned)(-1)) {
1125 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1126 * and lookahead == 1 (input done one byte at time)
1130 /* If the window is almost full and there is insufficient lookahead,
1131 * move the upper half to the lower one to make room in the upper half.
1133 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1135 /* By the IN assertion, the window is not empty so we can't confuse
1136 * more == 0 with more == 64K on a 16 bit machine.
1138 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1140 s->match_start -= wsize;
1141 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1143 s->block_start -= (long) wsize;
1145 /* Slide the hash table (could be avoided with 32 bit values
1146 at the expense of memory usage):
1152 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1159 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1160 /* If n is not on any hash chain, prev[n] is garbage but
1161 * its value will never be used.
1167 if (s->strm->avail_in == 0) return;
1169 /* If there was no sliding:
1170 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1171 * more == window_size - lookahead - strstart
1172 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1173 * => more >= window_size - 2*WSIZE + 2
1174 * In the BIG_MEM or MMAP case (not yet supported),
1175 * window_size == input_size + MIN_LOOKAHEAD &&
1176 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1177 * Otherwise, window_size == 2*WSIZE so more >= 2.
1178 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1180 Assert(more >= 2, "more < 2");
1182 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1186 /* Initialize the hash value now that we have some input: */
1187 if (s->lookahead >= MIN_MATCH) {
1188 s->ins_h = s->window[s->strstart];
1189 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1191 Call UPDATE_HASH() MIN_MATCH-3 more times
1194 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1195 * but this is not important since only literal bytes will be emitted.
1198 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1201 /* ===========================================================================
1202 * Flush the current block, with given end-of-file flag.
1203 * IN assertion: strstart is set to the end of the current match.
1205 #define FLUSH_BLOCK_ONLY(s, flush) { \
1206 ct_flush_block(s, (s->block_start >= 0L ? \
1207 (charf *)&s->window[(unsigned)s->block_start] : \
1208 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1209 s->block_start = s->strstart; \
1210 flush_pending(s->strm); \
1211 Tracev((stderr,"[FLUSH]")); \
1214 /* Same but force premature exit if necessary. */
1215 #define FLUSH_BLOCK(s, flush) { \
1216 FLUSH_BLOCK_ONLY(s, flush); \
1217 if (s->strm->avail_out == 0) return 1; \
1220 /* ===========================================================================
1221 * Compress as much as possible from the input stream, return true if
1222 * processing was terminated prematurely (no more input or output space).
1223 * This function does not perform lazy evaluationof matches and inserts
1224 * new strings in the dictionary only for unmatched strings or for short
1225 * matches. It is used only for the fast compression options.
1227 local int deflate_fast(s, flush)
1231 IPos hash_head = NIL; /* head of the hash chain */
1232 int bflush; /* set if current block must be flushed */
1234 s->prev_length = MIN_MATCH-1;
1237 /* Make sure that we always have enough lookahead, except
1238 * at the end of the input file. We need MAX_MATCH bytes
1239 * for the next match, plus MIN_MATCH bytes to insert the
1240 * string following the next match.
1242 if (s->lookahead < MIN_LOOKAHEAD) {
1244 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1246 if (s->lookahead == 0) break; /* flush the current block */
1249 /* Insert the string window[strstart .. strstart+2] in the
1250 * dictionary, and set hash_head to the head of the hash chain:
1252 if (s->lookahead >= MIN_MATCH) {
1253 INSERT_STRING(s, s->strstart, hash_head);
1256 /* Find the longest match, discarding those <= prev_length.
1257 * At this point we have always match_length < MIN_MATCH
1259 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1260 /* To simplify the code, we prevent matches with the string
1261 * of window index 0 (in particular we have to avoid a match
1262 * of the string with itself at the start of the input file).
1264 if (s->strategy != Z_HUFFMAN_ONLY) {
1265 s->match_length = longest_match (s, hash_head);
1267 /* longest_match() sets match_start */
1269 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1271 if (s->match_length >= MIN_MATCH) {
1272 check_match(s, s->strstart, s->match_start, s->match_length);
1274 bflush = ct_tally(s, s->strstart - s->match_start,
1275 s->match_length - MIN_MATCH);
1277 s->lookahead -= s->match_length;
1279 /* Insert new strings in the hash table only if the match length
1280 * is not too large. This saves time but degrades compression.
1282 if (s->match_length <= s->max_insert_length &&
1283 s->lookahead >= MIN_MATCH) {
1284 s->match_length--; /* string at strstart already in hash table */
1287 INSERT_STRING(s, s->strstart, hash_head);
1288 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1289 * always MIN_MATCH bytes ahead.
1291 } while (--s->match_length != 0);
1294 s->strstart += s->match_length;
1295 s->match_length = 0;
1296 s->ins_h = s->window[s->strstart];
1297 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1299 Call UPDATE_HASH() MIN_MATCH-3 more times
1301 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1302 * matter since it will be recomputed at next deflate call.
1306 /* No match, output a literal byte */
1307 Tracevv((stderr,"%c", s->window[s->strstart]));
1308 bflush = ct_tally (s, 0, s->window[s->strstart]);
1312 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1314 FLUSH_BLOCK(s, flush);
1315 return 0; /* normal exit */
1318 /* ===========================================================================
1319 * Same as above, but achieves better compression. We use a lazy
1320 * evaluation for matches: a match is finally adopted only if there is
1321 * no better match at the next window position.
1323 local int deflate_slow(s, flush)
1327 IPos hash_head = NIL; /* head of hash chain */
1328 int bflush; /* set if current block must be flushed */
1330 /* Process the input block. */
1332 /* Make sure that we always have enough lookahead, except
1333 * at the end of the input file. We need MAX_MATCH bytes
1334 * for the next match, plus MIN_MATCH bytes to insert the
1335 * string following the next match.
1337 if (s->lookahead < MIN_LOOKAHEAD) {
1339 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1341 if (s->lookahead == 0) break; /* flush the current block */
1344 /* Insert the string window[strstart .. strstart+2] in the
1345 * dictionary, and set hash_head to the head of the hash chain:
1347 if (s->lookahead >= MIN_MATCH) {
1348 INSERT_STRING(s, s->strstart, hash_head);
1351 if (flush == Z_INSERT_ONLY) {
1357 /* Find the longest match, discarding those <= prev_length.
1359 s->prev_length = s->match_length, s->prev_match = s->match_start;
1360 s->match_length = MIN_MATCH-1;
1362 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1363 s->strstart - hash_head <= MAX_DIST(s)) {
1364 /* To simplify the code, we prevent matches with the string
1365 * of window index 0 (in particular we have to avoid a match
1366 * of the string with itself at the start of the input file).
1368 if (s->strategy != Z_HUFFMAN_ONLY) {
1369 s->match_length = longest_match (s, hash_head);
1371 /* longest_match() sets match_start */
1372 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1374 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1375 (s->match_length == MIN_MATCH &&
1376 s->strstart - s->match_start > TOO_FAR))) {
1378 /* If prev_match is also MIN_MATCH, match_start is garbage
1379 * but we will ignore the current match anyway.
1381 s->match_length = MIN_MATCH-1;
1384 /* If there was a match at the previous step and the current
1385 * match is not better, output the previous match:
1387 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1388 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1389 /* Do not insert strings in hash table beyond this. */
1391 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1393 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1394 s->prev_length - MIN_MATCH);
1396 /* Insert in hash table all strings up to the end of the match.
1397 * strstart-1 and strstart are already inserted. If there is not
1398 * enough lookahead, the last two strings are not inserted in
1401 s->lookahead -= s->prev_length-1;
1402 s->prev_length -= 2;
1404 if (++s->strstart <= max_insert) {
1405 INSERT_STRING(s, s->strstart, hash_head);
1407 } while (--s->prev_length != 0);
1408 s->match_available = 0;
1409 s->match_length = MIN_MATCH-1;
1412 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1414 } else if (s->match_available) {
1415 /* If there was no match at the previous position, output a
1416 * single literal. If there was a match but the current match
1417 * is longer, truncate the previous match to a single literal.
1419 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1420 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1421 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1425 if (s->strm->avail_out == 0) return 1;
1427 /* There is no previous match to compare with, wait for
1428 * the next step to decide.
1430 s->match_available = 1;
1435 if (flush == Z_INSERT_ONLY) {
1436 s->block_start = s->strstart;
1439 Assert (flush != Z_NO_FLUSH, "no flush?");
1440 if (s->match_available) {
1441 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1442 ct_tally (s, 0, s->window[s->strstart-1]);
1443 s->match_available = 0;
1445 FLUSH_BLOCK(s, flush);
1451 /* trees.c -- output deflated data using Huffman coding
1452 * Copyright (C) 1995 Jean-loup Gailly
1453 * For conditions of distribution and use, see copyright notice in zlib.h
1459 * The "deflation" process uses several Huffman trees. The more
1460 * common source values are represented by shorter bit sequences.
1462 * Each code tree is stored in a compressed form which is itself
1463 * a Huffman encoding of the lengths of all the code strings (in
1464 * ascending order by source values). The actual code strings are
1465 * reconstructed from the lengths in the inflate process, as described
1466 * in the deflate specification.
1470 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1471 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1474 * Data Compression: Methods and Theory, pp. 49-50.
1475 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1479 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1482 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
1488 /* ===========================================================================
1492 #define MAX_BL_BITS 7
1493 /* Bit length codes must not exceed MAX_BL_BITS bits */
1495 #define END_BLOCK 256
1496 /* end of block literal code */
1499 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1501 #define REPZ_3_10 17
1502 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1504 #define REPZ_11_138 18
1505 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1507 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1508 = {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};
1510 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1511 = {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};
1513 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1514 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1516 local uch bl_order[BL_CODES]
1517 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1518 /* The lengths of the bit length codes are sent in order of decreasing
1519 * probability, to avoid transmitting the lengths for unused bit length codes.
1522 #define Buf_size (8 * 2*sizeof(char))
1523 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1524 * more than 16 bits on some systems.)
1527 /* ===========================================================================
1528 * Local data. These are initialized only once.
1529 * To do: initialize at compile time to be completely reentrant. ???
1532 local ct_data static_ltree[L_CODES+2];
1533 /* The static literal tree. Since the bit lengths are imposed, there is no
1534 * need for the L_CODES extra codes used during heap construction. However
1535 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1539 local ct_data static_dtree[D_CODES];
1540 /* The static distance tree. (Actually a trivial tree since all codes use
1544 local uch dist_code[512];
1545 /* distance codes. The first 256 values correspond to the distances
1546 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1547 * the 15 bit distances.
1550 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1551 /* length code for each normalized match length (0 == MIN_MATCH) */
1553 local int base_length[LENGTH_CODES];
1554 /* First normalized length for each code (0 = MIN_MATCH) */
1556 local int base_dist[D_CODES];
1557 /* First normalized distance for each code (0 = distance of 1) */
1559 struct static_tree_desc_s {
1560 ct_data *static_tree; /* static tree or NULL */
1561 intf *extra_bits; /* extra bits for each code or NULL */
1562 int extra_base; /* base index for extra_bits */
1563 int elems; /* max number of elements in the tree */
1564 int max_length; /* max bit length for the codes */
1567 local static_tree_desc static_l_desc =
1568 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1570 local static_tree_desc static_d_desc =
1571 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1573 local static_tree_desc static_bl_desc =
1574 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1576 /* ===========================================================================
1577 * Local (static) routines in this file.
1580 local void ct_static_init OF((void));
1581 local void init_block OF((deflate_state *s));
1582 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1583 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1584 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1585 local void build_tree OF((deflate_state *s, tree_desc *desc));
1586 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1587 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1588 local int build_bl_tree OF((deflate_state *s));
1589 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1591 local void compress_block OF((deflate_state *s, ct_data *ltree,
1593 local void set_data_type OF((deflate_state *s));
1594 local unsigned bi_reverse OF((unsigned value, int length));
1595 local void bi_windup OF((deflate_state *s));
1596 local void bi_flush OF((deflate_state *s));
1597 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1601 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1602 /* Send a code of the given tree. c and tree must not have side effects */
1604 #else /* DEBUG_ZLIB */
1605 # define send_code(s, c, tree) \
1606 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1607 send_bits(s, tree[c].Code, tree[c].Len); }
1610 #define d_code(dist) \
1611 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1612 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1613 * must not have side effects. dist_code[256] and dist_code[257] are never
1617 /* ===========================================================================
1618 * Output a short LSB first on the stream.
1619 * IN assertion: there is enough room in pendingBuf.
1621 #define put_short(s, w) { \
1622 put_byte(s, (uch)((w) & 0xff)); \
1623 put_byte(s, (uch)((ush)(w) >> 8)); \
1626 /* ===========================================================================
1627 * Send a value on a given number of bits.
1628 * IN assertion: length <= 16 and value fits in length bits.
1631 local void send_bits OF((deflate_state *s, int value, int length));
1633 local void send_bits(s, value, length)
1635 int value; /* value to send */
1636 int length; /* number of bits */
1638 Tracev((stderr," l %2d v %4x ", length, value));
1639 Assert(length > 0 && length <= 15, "invalid length");
1640 s->bits_sent += (ulg)length;
1642 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1643 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1644 * unused bits in value.
1646 if (s->bi_valid > (int)Buf_size - length) {
1647 s->bi_buf |= (value << s->bi_valid);
1648 put_short(s, s->bi_buf);
1649 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1650 s->bi_valid += length - Buf_size;
1652 s->bi_buf |= value << s->bi_valid;
1653 s->bi_valid += length;
1656 #else /* !DEBUG_ZLIB */
1658 #define send_bits(s, value, length) \
1659 { int len = length;\
1660 if (s->bi_valid > (int)Buf_size - len) {\
1662 s->bi_buf |= (val << s->bi_valid);\
1663 put_short(s, s->bi_buf);\
1664 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1665 s->bi_valid += len - Buf_size;\
1667 s->bi_buf |= (value) << s->bi_valid;\
1668 s->bi_valid += len;\
1671 #endif /* DEBUG_ZLIB */
1674 #define MAX(a,b) (a >= b ? a : b)
1675 /* the arguments must not have side effects */
1677 /* ===========================================================================
1678 * Initialize the various 'constant' tables.
1679 * To do: do this at compile time.
1681 local void ct_static_init()
1683 int n; /* iterates over tree elements */
1684 int bits; /* bit counter */
1685 int length; /* length value */
1686 int code; /* code value */
1687 int dist; /* distance index */
1688 ush bl_count[MAX_BITS+1];
1689 /* number of codes at each bit length for an optimal tree */
1691 /* Initialize the mapping length (0..255) -> length code (0..28) */
1693 for (code = 0; code < LENGTH_CODES-1; code++) {
1694 base_length[code] = length;
1695 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1696 length_code[length++] = (uch)code;
1699 Assert (length == 256, "ct_static_init: length != 256");
1700 /* Note that the length 255 (match length 258) can be represented
1701 * in two different ways: code 284 + 5 bits or code 285, so we
1702 * overwrite length_code[255] to use the best encoding:
1704 length_code[length-1] = (uch)code;
1706 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1708 for (code = 0 ; code < 16; code++) {
1709 base_dist[code] = dist;
1710 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1711 dist_code[dist++] = (uch)code;
1714 Assert (dist == 256, "ct_static_init: dist != 256");
1715 dist >>= 7; /* from now on, all distances are divided by 128 */
1716 for ( ; code < D_CODES; code++) {
1717 base_dist[code] = dist << 7;
1718 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1719 dist_code[256 + dist++] = (uch)code;
1722 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1724 /* Construct the codes of the static literal tree */
1725 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1727 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1728 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1729 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1730 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1731 /* Codes 286 and 287 do not exist, but we must include them in the
1732 * tree construction to get a canonical Huffman tree (longest code
1735 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1737 /* The static distance tree is trivial: */
1738 for (n = 0; n < D_CODES; n++) {
1739 static_dtree[n].Len = 5;
1740 static_dtree[n].Code = bi_reverse(n, 5);
1744 /* ===========================================================================
1745 * Initialize the tree data structures for a new zlib stream.
1747 local void ct_init(s)
1750 if (static_dtree[0].Len == 0) {
1751 ct_static_init(); /* To do: at compile time */
1754 s->compressed_len = 0L;
1756 s->l_desc.dyn_tree = s->dyn_ltree;
1757 s->l_desc.stat_desc = &static_l_desc;
1759 s->d_desc.dyn_tree = s->dyn_dtree;
1760 s->d_desc.stat_desc = &static_d_desc;
1762 s->bl_desc.dyn_tree = s->bl_tree;
1763 s->bl_desc.stat_desc = &static_bl_desc;
1767 s->last_eob_len = 8; /* enough lookahead for inflate */
1771 s->blocks_in_packet = 0;
1773 /* Initialize the first block of the first file: */
1777 /* ===========================================================================
1778 * Initialize a new block.
1780 local void init_block(s)
1783 int n; /* iterates over tree elements */
1785 /* Initialize the trees. */
1786 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1787 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1788 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1790 s->dyn_ltree[END_BLOCK].Freq = 1;
1791 s->opt_len = s->static_len = 0L;
1792 s->last_lit = s->matches = 0;
1796 /* Index within the heap array of least frequent node in the Huffman tree */
1799 /* ===========================================================================
1800 * Remove the smallest element from the heap and recreate the heap with
1801 * one less element. Updates heap and heap_len.
1803 #define pqremove(s, tree, top) \
1805 top = s->heap[SMALLEST]; \
1806 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1807 pqdownheap(s, tree, SMALLEST); \
1810 /* ===========================================================================
1811 * Compares to subtrees, using the tree depth as tie breaker when
1812 * the subtrees have equal frequency. This minimizes the worst case length.
1814 #define smaller(tree, n, m, depth) \
1815 (tree[n].Freq < tree[m].Freq || \
1816 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1818 /* ===========================================================================
1819 * Restore the heap property by moving down the tree starting at node k,
1820 * exchanging a node with the smallest of its two sons if necessary, stopping
1821 * when the heap property is re-established (each father smaller than its
1824 local void pqdownheap(s, tree, k)
1826 ct_data *tree; /* the tree to restore */
1827 int k; /* node to move down */
1830 int j = k << 1; /* left son of k */
1831 while (j <= s->heap_len) {
1832 /* Set j to the smallest of the two sons: */
1833 if (j < s->heap_len &&
1834 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1837 /* Exit if v is smaller than both sons */
1838 if (smaller(tree, v, s->heap[j], s->depth)) break;
1840 /* Exchange v with the smallest son */
1841 s->heap[k] = s->heap[j]; k = j;
1843 /* And continue down the tree, setting j to the left son of k */
1849 /* ===========================================================================
1850 * Compute the optimal bit lengths for a tree and update the total bit length
1851 * for the current block.
1852 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1853 * above are the tree nodes sorted by increasing frequency.
1854 * OUT assertions: the field len is set to the optimal bit length, the
1855 * array bl_count contains the frequencies for each bit length.
1856 * The length opt_len is updated; static_len is also updated if stree is
1859 local void gen_bitlen(s, desc)
1861 tree_desc *desc; /* the tree descriptor */
1863 ct_data *tree = desc->dyn_tree;
1864 int max_code = desc->max_code;
1865 ct_data *stree = desc->stat_desc->static_tree;
1866 intf *extra = desc->stat_desc->extra_bits;
1867 int base = desc->stat_desc->extra_base;
1868 int max_length = desc->stat_desc->max_length;
1869 int h; /* heap index */
1870 int n, m; /* iterate over the tree elements */
1871 int bits; /* bit length */
1872 int xbits; /* extra bits */
1873 ush f; /* frequency */
1874 int overflow = 0; /* number of elements with bit length too large */
1876 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1878 /* In a first pass, compute the optimal bit lengths (which may
1879 * overflow in the case of the bit length tree).
1881 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1883 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1885 bits = tree[tree[n].Dad].Len + 1;
1886 if (bits > max_length) bits = max_length, overflow++;
1887 tree[n].Len = (ush)bits;
1888 /* We overwrite tree[n].Dad which is no longer needed */
1890 if (n > max_code) continue; /* not a leaf node */
1892 s->bl_count[bits]++;
1894 if (n >= base) xbits = extra[n-base];
1896 s->opt_len += (ulg)f * (bits + xbits);
1897 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1899 if (overflow == 0) return;
1901 Trace((stderr,"\nbit length overflow\n"));
1902 /* This happens for example on obj2 and pic of the Calgary corpus */
1904 /* Find the first bit length which could increase: */
1906 bits = max_length-1;
1907 while (s->bl_count[bits] == 0) bits--;
1908 s->bl_count[bits]--; /* move one leaf down the tree */
1909 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1910 s->bl_count[max_length]--;
1911 /* The brother of the overflow item also moves one step up,
1912 * but this does not affect bl_count[max_length]
1915 } while (overflow > 0);
1917 /* Now recompute all bit lengths, scanning in increasing frequency.
1918 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1919 * lengths instead of fixing only the wrong ones. This idea is taken
1920 * from 'ar' written by Haruhiko Okumura.)
1922 for (bits = max_length; bits != 0; bits--) {
1923 n = s->bl_count[bits];
1926 if (m > max_code) continue;
1927 if (tree[m].Len != (unsigned) bits) {
1928 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1929 s->opt_len += ((long)bits - (long)tree[m].Len)
1930 *(long)tree[m].Freq;
1931 tree[m].Len = (ush)bits;
1938 /* ===========================================================================
1939 * Generate the codes for a given tree and bit counts (which need not be
1941 * IN assertion: the array bl_count contains the bit length statistics for
1942 * the given tree and the field len is set for all tree elements.
1943 * OUT assertion: the field code is set for all tree elements of non
1946 local void gen_codes (tree, max_code, bl_count)
1947 ct_data *tree; /* the tree to decorate */
1948 int max_code; /* largest code with non zero frequency */
1949 ushf *bl_count; /* number of codes at each bit length */
1951 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1952 ush code = 0; /* running code value */
1953 int bits; /* bit index */
1954 int n; /* code index */
1956 /* The distribution counts are first used to generate the code values
1957 * without bit reversal.
1959 for (bits = 1; bits <= MAX_BITS; bits++) {
1960 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1962 /* Check that the bit counts in bl_count are consistent. The last code
1965 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1966 "inconsistent bit counts");
1967 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1969 for (n = 0; n <= max_code; n++) {
1970 int len = tree[n].Len;
1971 if (len == 0) continue;
1972 /* Now reverse the bits */
1973 tree[n].Code = bi_reverse(next_code[len]++, len);
1975 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1976 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1980 /* ===========================================================================
1981 * Construct one Huffman tree and assigns the code bit strings and lengths.
1982 * Update the total bit length for the current block.
1983 * IN assertion: the field freq is set for all tree elements.
1984 * OUT assertions: the fields len and code are set to the optimal bit length
1985 * and corresponding code. The length opt_len is updated; static_len is
1986 * also updated if stree is not null. The field max_code is set.
1988 local void build_tree(s, desc)
1990 tree_desc *desc; /* the tree descriptor */
1992 ct_data *tree = desc->dyn_tree;
1993 ct_data *stree = desc->stat_desc->static_tree;
1994 int elems = desc->stat_desc->elems;
1995 int n, m; /* iterate over heap elements */
1996 int max_code = -1; /* largest code with non zero frequency */
1997 int node; /* new node being created */
1999 /* Construct the initial heap, with least frequent element in
2000 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2001 * heap[0] is not used.
2003 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2005 for (n = 0; n < elems; n++) {
2006 if (tree[n].Freq != 0) {
2007 s->heap[++(s->heap_len)] = max_code = n;
2014 /* The pkzip format requires that at least one distance code exists,
2015 * and that at least one bit should be sent even if there is only one
2016 * possible code. So to avoid special checks later on we force at least
2017 * two codes of non zero frequency.
2019 while (s->heap_len < 2) {
2020 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2021 tree[node].Freq = 1;
2023 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2024 /* node is 0 or 1 so it does not have extra bits */
2026 desc->max_code = max_code;
2028 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2029 * establish sub-heaps of increasing lengths:
2031 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2033 /* Construct the Huffman tree by repeatedly combining the least two
2036 node = elems; /* next internal node of the tree */
2038 pqremove(s, tree, n); /* n = node of least frequency */
2039 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2041 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2042 s->heap[--(s->heap_max)] = m;
2044 /* Create a new node father of n and m */
2045 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2046 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2047 tree[n].Dad = tree[m].Dad = (ush)node;
2049 if (tree == s->bl_tree) {
2050 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2051 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2054 /* and insert the new node in the heap */
2055 s->heap[SMALLEST] = node++;
2056 pqdownheap(s, tree, SMALLEST);
2058 } while (s->heap_len >= 2);
2060 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2062 /* At this point, the fields freq and dad are set. We can now
2063 * generate the bit lengths.
2065 gen_bitlen(s, (tree_desc *)desc);
2067 /* The field len is now set, we can generate the bit codes */
2068 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2071 /* ===========================================================================
2072 * Scan a literal or distance tree to determine the frequencies of the codes
2073 * in the bit length tree.
2075 local void scan_tree (s, tree, max_code)
2077 ct_data *tree; /* the tree to be scanned */
2078 int max_code; /* and its largest code of non zero frequency */
2080 int n; /* iterates over all tree elements */
2081 int prevlen = -1; /* last emitted length */
2082 int curlen; /* length of current code */
2083 int nextlen = tree[0].Len; /* length of next code */
2084 int count = 0; /* repeat count of the current code */
2085 int max_count = 7; /* max repeat count */
2086 int min_count = 4; /* min repeat count */
2088 if (nextlen == 0) max_count = 138, min_count = 3;
2089 tree[max_code+1].Len = (ush)0xffff; /* guard */
2091 for (n = 0; n <= max_code; n++) {
2092 curlen = nextlen; nextlen = tree[n+1].Len;
2093 if (++count < max_count && curlen == nextlen) {
2095 } else if (count < min_count) {
2096 s->bl_tree[curlen].Freq += count;
2097 } else if (curlen != 0) {
2098 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2099 s->bl_tree[REP_3_6].Freq++;
2100 } else if (count <= 10) {
2101 s->bl_tree[REPZ_3_10].Freq++;
2103 s->bl_tree[REPZ_11_138].Freq++;
2105 count = 0; prevlen = curlen;
2107 max_count = 138, min_count = 3;
2108 } else if (curlen == nextlen) {
2109 max_count = 6, min_count = 3;
2111 max_count = 7, min_count = 4;
2116 /* ===========================================================================
2117 * Send a literal or distance tree in compressed form, using the codes in
2120 local void send_tree (s, tree, max_code)
2122 ct_data *tree; /* the tree to be scanned */
2123 int max_code; /* and its largest code of non zero frequency */
2125 int n; /* iterates over all tree elements */
2126 int prevlen = -1; /* last emitted length */
2127 int curlen; /* length of current code */
2128 int nextlen = tree[0].Len; /* length of next code */
2129 int count = 0; /* repeat count of the current code */
2130 int max_count = 7; /* max repeat count */
2131 int min_count = 4; /* min repeat count */
2133 /* tree[max_code+1].Len = -1; */ /* guard already set */
2134 if (nextlen == 0) max_count = 138, min_count = 3;
2136 for (n = 0; n <= max_code; n++) {
2137 curlen = nextlen; nextlen = tree[n+1].Len;
2138 if (++count < max_count && curlen == nextlen) {
2140 } else if (count < min_count) {
2141 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2143 } else if (curlen != 0) {
2144 if (curlen != prevlen) {
2145 send_code(s, curlen, s->bl_tree); count--;
2147 Assert(count >= 3 && count <= 6, " 3_6?");
2148 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2150 } else if (count <= 10) {
2151 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2154 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2156 count = 0; prevlen = curlen;
2158 max_count = 138, min_count = 3;
2159 } else if (curlen == nextlen) {
2160 max_count = 6, min_count = 3;
2162 max_count = 7, min_count = 4;
2167 /* ===========================================================================
2168 * Construct the Huffman tree for the bit lengths and return the index in
2169 * bl_order of the last bit length code to send.
2171 local int build_bl_tree(s)
2174 int max_blindex; /* index of last bit length code of non zero freq */
2176 /* Determine the bit length frequencies for literal and distance trees */
2177 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2178 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2180 /* Build the bit length tree: */
2181 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2182 /* opt_len now includes the length of the tree representations, except
2183 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2186 /* Determine the number of bit length codes to send. The pkzip format
2187 * requires that at least 4 bit length codes be sent. (appnote.txt says
2188 * 3 but the actual value used is 4.)
2190 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2191 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2193 /* Update opt_len to include the bit length tree and counts */
2194 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2195 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2196 s->opt_len, s->static_len));
2201 /* ===========================================================================
2202 * Send the header for a block using dynamic Huffman trees: the counts, the
2203 * lengths of the bit length codes, the literal tree and the distance tree.
2204 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2206 local void send_all_trees(s, lcodes, dcodes, blcodes)
2208 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2210 int rank; /* index in bl_order */
2212 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2213 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2215 Tracev((stderr, "\nbl counts: "));
2216 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2217 send_bits(s, dcodes-1, 5);
2218 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2219 for (rank = 0; rank < blcodes; rank++) {
2220 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2221 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2223 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2225 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2226 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2228 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2229 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2232 /* ===========================================================================
2233 * Send a stored block
2235 local void ct_stored_block(s, buf, stored_len, eof)
2237 charf *buf; /* input block */
2238 ulg stored_len; /* length of input block */
2239 int eof; /* true if this is the last block for a file */
2241 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2242 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2243 s->compressed_len += (stored_len + 4) << 3;
2245 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2248 /* Send just the `stored block' type code without any length bytes or data.
2250 local void ct_stored_type_only(s)
2253 send_bits(s, (STORED_BLOCK << 1), 3);
2255 s->compressed_len = (s->compressed_len + 3) & ~7L;
2259 /* ===========================================================================
2260 * Send one empty static block to give enough lookahead for inflate.
2261 * This takes 10 bits, of which 7 may remain in the bit buffer.
2262 * The current inflate code requires 9 bits of lookahead. If the EOB
2263 * code for the previous block was coded on 5 bits or less, inflate
2264 * may have only 5+3 bits of lookahead to decode this EOB.
2265 * (There are no problems if the previous block is stored or fixed.)
2267 local void ct_align(s)
2270 send_bits(s, STATIC_TREES<<1, 3);
2271 send_code(s, END_BLOCK, static_ltree);
2272 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2274 /* Of the 10 bits for the empty block, we have already sent
2275 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2276 * block was thus its length plus what we have just sent.
2278 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2279 send_bits(s, STATIC_TREES<<1, 3);
2280 send_code(s, END_BLOCK, static_ltree);
2281 s->compressed_len += 10L;
2284 s->last_eob_len = 7;
2287 /* ===========================================================================
2288 * Determine the best encoding for the current block: dynamic trees, static
2289 * trees or store, and output the encoded block to the zip file. This function
2290 * returns the total compressed length for the file so far.
2292 local ulg ct_flush_block(s, buf, stored_len, flush)
2294 charf *buf; /* input block, or NULL if too old */
2295 ulg stored_len; /* length of input block */
2296 int flush; /* Z_FINISH if this is the last block for a file */
2298 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2299 int max_blindex; /* index of last bit length code of non zero freq */
2300 int eof = flush == Z_FINISH;
2302 ++s->blocks_in_packet;
2304 /* Check if the file is ascii or binary */
2305 if (s->data_type == UNKNOWN) set_data_type(s);
2307 /* Construct the literal and distance trees */
2308 build_tree(s, (tree_desc *)(&(s->l_desc)));
2309 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2312 build_tree(s, (tree_desc *)(&(s->d_desc)));
2313 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2315 /* At this point, opt_len and static_len are the total bit lengths of
2316 * the compressed block data, excluding the tree representations.
2319 /* Build the bit length tree for the above two trees, and get the index
2320 * in bl_order of the last bit length code to send.
2322 max_blindex = build_bl_tree(s);
2324 /* Determine the best encoding. Compute first the block length in bytes */
2325 opt_lenb = (s->opt_len+3+7)>>3;
2326 static_lenb = (s->static_len+3+7)>>3;
2328 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2329 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2332 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2334 /* If compression failed and this is the first and last block,
2335 * and if the .zip file can be seeked (to rewrite the local header),
2336 * the whole file is transformed into a stored file:
2338 #ifdef STORED_FILE_OK
2339 # ifdef FORCE_STORED_FILE
2340 if (eof && compressed_len == 0L) /* force stored file */
2342 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2345 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2346 if (buf == (charf*)0) error ("block vanished");
2348 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2349 s->compressed_len = stored_len << 3;
2352 #endif /* STORED_FILE_OK */
2354 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
2355 * compression, and this block contains all the data since the last
2356 * time we used Z_PACKET_FLUSH, then just omit this block completely
2359 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
2360 && opt_lenb > stored_len - s->minCompr) {
2361 s->blocks_in_packet = 0;
2362 /* output nothing */
2366 if (buf != (char*)0) /* force stored block */
2368 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2369 /* 4: two words for the lengths */
2372 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2373 * Otherwise we can't have processed more than WSIZE input bytes since
2374 * the last block flush, because compression would have been
2375 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2376 * transform a block into a stored block.
2378 ct_stored_block(s, buf, stored_len, eof);
2382 if (static_lenb >= 0) /* force static trees */
2384 if (static_lenb == opt_lenb)
2387 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2388 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2389 s->compressed_len += 3 + s->static_len;
2391 send_bits(s, (DYN_TREES<<1)+eof, 3);
2392 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2394 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2395 s->compressed_len += 3 + s->opt_len;
2397 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2402 s->compressed_len += 7; /* align on byte boundary */
2404 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2405 s->compressed_len-7*eof));
2407 return s->compressed_len >> 3;
2410 /* ===========================================================================
2411 * Save the match info and tally the frequency counts. Return true if
2412 * the current block must be flushed.
2414 local int ct_tally (s, dist, lc)
2416 int dist; /* distance of matched string */
2417 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2419 s->d_buf[s->last_lit] = (ush)dist;
2420 s->l_buf[s->last_lit++] = (uch)lc;
2422 /* lc is the unmatched char */
2423 s->dyn_ltree[lc].Freq++;
2426 /* Here, lc is the match length - MIN_MATCH */
2427 dist--; /* dist = match distance - 1 */
2428 Assert((ush)dist < (ush)MAX_DIST(s) &&
2429 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2430 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2432 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2433 s->dyn_dtree[d_code(dist)].Freq++;
2436 /* Try to guess if it is profitable to stop the current block here */
2437 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2438 /* Compute an upper bound for the compressed length */
2439 ulg out_length = (ulg)s->last_lit*8L;
2440 ulg in_length = (ulg)s->strstart - s->block_start;
2442 for (dcode = 0; dcode < D_CODES; dcode++) {
2443 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2444 (5L+extra_dbits[dcode]);
2447 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2448 s->last_lit, in_length, out_length,
2449 100L - out_length*100L/in_length));
2450 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2452 return (s->last_lit == s->lit_bufsize-1);
2453 /* We avoid equality with lit_bufsize because of wraparound at 64K
2454 * on 16 bit machines and because stored blocks are restricted to
2459 /* ===========================================================================
2460 * Send the block data compressed using the given Huffman trees
2462 local void compress_block(s, ltree, dtree)
2464 ct_data *ltree; /* literal tree */
2465 ct_data *dtree; /* distance tree */
2467 unsigned dist; /* distance of matched string */
2468 int lc; /* match length or unmatched char (if dist == 0) */
2469 unsigned lx = 0; /* running index in l_buf */
2470 unsigned code; /* the code to send */
2471 int extra; /* number of extra bits to send */
2473 if (s->last_lit != 0) do {
2474 dist = s->d_buf[lx];
2475 lc = s->l_buf[lx++];
2477 send_code(s, lc, ltree); /* send a literal byte */
2478 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2480 /* Here, lc is the match length - MIN_MATCH */
2481 code = length_code[lc];
2482 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2483 extra = extra_lbits[code];
2485 lc -= base_length[code];
2486 send_bits(s, lc, extra); /* send the extra length bits */
2488 dist--; /* dist is now the match distance - 1 */
2489 code = d_code(dist);
2490 Assert (code < D_CODES, "bad d_code");
2492 send_code(s, code, dtree); /* send the distance code */
2493 extra = extra_dbits[code];
2495 dist -= base_dist[code];
2496 send_bits(s, dist, extra); /* send the extra distance bits */
2498 } /* literal or match pair ? */
2500 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2501 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2503 } while (lx < s->last_lit);
2505 send_code(s, END_BLOCK, ltree);
2506 s->last_eob_len = ltree[END_BLOCK].Len;
2509 /* ===========================================================================
2510 * Set the data type to ASCII or BINARY, using a crude approximation:
2511 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2512 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2513 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2515 local void set_data_type(s)
2519 unsigned ascii_freq = 0;
2520 unsigned bin_freq = 0;
2521 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2522 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2523 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2524 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2527 /* ===========================================================================
2528 * Reverse the first len bits of a code, using straightforward code (a faster
2529 * method would use a table)
2530 * IN assertion: 1 <= len <= 15
2532 local unsigned bi_reverse(code, len)
2533 unsigned code; /* the value to invert */
2534 int len; /* its bit length */
2536 register unsigned res = 0;
2539 code >>= 1, res <<= 1;
2540 } while (--len > 0);
2544 /* ===========================================================================
2545 * Flush the bit buffer, keeping at most 7 bits in it.
2547 local void bi_flush(s)
2550 if (s->bi_valid == 16) {
2551 put_short(s, s->bi_buf);
2554 } else if (s->bi_valid >= 8) {
2555 put_byte(s, (Byte)s->bi_buf);
2561 /* ===========================================================================
2562 * Flush the bit buffer and align the output on a byte boundary
2564 local void bi_windup(s)
2567 if (s->bi_valid > 8) {
2568 put_short(s, s->bi_buf);
2569 } else if (s->bi_valid > 0) {
2570 put_byte(s, (Byte)s->bi_buf);
2575 s->bits_sent = (s->bits_sent+7) & ~7;
2579 /* ===========================================================================
2580 * Copy a stored block, storing first the length and its
2581 * one's complement if requested.
2583 local void copy_block(s, buf, len, header)
2585 charf *buf; /* the input data */
2586 unsigned len; /* its length */
2587 int header; /* true if block header must be written */
2589 bi_windup(s); /* align on byte boundary */
2590 s->last_eob_len = 8; /* enough lookahead for inflate */
2593 put_short(s, (ush)len);
2594 put_short(s, (ush)~len);
2596 s->bits_sent += 2*16;
2600 s->bits_sent += (ulg)len<<3;
2603 put_byte(s, *buf++);
2609 /* infblock.h -- header to use infblock.c
2610 * Copyright (C) 1995 Mark Adler
2611 * For conditions of distribution and use, see copyright notice in zlib.h
2614 /* WARNING: this file should *not* be used by applications. It is
2615 part of the implementation of the compression library and is
2616 subject to change. Applications should only use zlib.h.
2619 struct inflate_blocks_state;
2620 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2622 local inflate_blocks_statef * inflate_blocks_new OF((
2624 check_func c, /* check function */
2625 uInt w)); /* window size */
2627 local int inflate_blocks OF((
2628 inflate_blocks_statef *,
2630 int)); /* initial return code */
2632 local void inflate_blocks_reset OF((
2633 inflate_blocks_statef *,
2635 uLongf *)); /* check value on output */
2637 local int inflate_blocks_free OF((
2638 inflate_blocks_statef *,
2640 uLongf *)); /* check value on output */
2642 local int inflate_addhistory OF((
2643 inflate_blocks_statef *,
2646 local int inflate_packet_flush OF((
2647 inflate_blocks_statef *));
2650 /* inftrees.h -- header to use inftrees.c
2651 * Copyright (C) 1995 Mark Adler
2652 * For conditions of distribution and use, see copyright notice in zlib.h
2655 /* WARNING: this file should *not* be used by applications. It is
2656 part of the implementation of the compression library and is
2657 subject to change. Applications should only use zlib.h.
2660 /* Huffman code lookup table entry--this entry is four bytes for machines
2661 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2663 typedef struct inflate_huft_s FAR inflate_huft;
2665 struct inflate_huft_s {
2668 Byte Exop; /* number of extra bits or operation */
2669 Byte Bits; /* number of bits in this code or subcode */
2671 uInt Nalloc; /* number of these allocated here */
2672 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2673 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2675 uInt Base; /* literal, length base, or distance base */
2676 inflate_huft *Next; /* pointer to next level of table */
2681 local uInt inflate_hufts;
2684 local int inflate_trees_bits OF((
2685 uIntf *, /* 19 code lengths */
2686 uIntf *, /* bits tree desired/actual depth */
2687 inflate_huft * FAR *, /* bits tree result */
2688 z_stream *)); /* for zalloc, zfree functions */
2690 local int inflate_trees_dynamic OF((
2691 uInt, /* number of literal/length codes */
2692 uInt, /* number of distance codes */
2693 uIntf *, /* that many (total) code lengths */
2694 uIntf *, /* literal desired/actual bit depth */
2695 uIntf *, /* distance desired/actual bit depth */
2696 inflate_huft * FAR *, /* literal/length tree result */
2697 inflate_huft * FAR *, /* distance tree result */
2698 z_stream *)); /* for zalloc, zfree functions */
2700 local int inflate_trees_fixed OF((
2701 uIntf *, /* literal desired/actual bit depth */
2702 uIntf *, /* distance desired/actual bit depth */
2703 inflate_huft * FAR *, /* literal/length tree result */
2704 inflate_huft * FAR *)); /* distance tree result */
2706 local int inflate_trees_free OF((
2707 inflate_huft *, /* tables to free */
2708 z_stream *)); /* for zfree function */
2712 /* infcodes.h -- header to use infcodes.c
2713 * Copyright (C) 1995 Mark Adler
2714 * For conditions of distribution and use, see copyright notice in zlib.h
2717 /* WARNING: this file should *not* be used by applications. It is
2718 part of the implementation of the compression library and is
2719 subject to change. Applications should only use zlib.h.
2722 struct inflate_codes_state;
2723 typedef struct inflate_codes_state FAR inflate_codes_statef;
2725 local inflate_codes_statef *inflate_codes_new OF((
2727 inflate_huft *, inflate_huft *,
2730 local int inflate_codes OF((
2731 inflate_blocks_statef *,
2735 local void inflate_codes_free OF((
2736 inflate_codes_statef *,
2741 /* inflate.c -- zlib interface to inflate modules
2742 * Copyright (C) 1995 Mark Adler
2743 * For conditions of distribution and use, see copyright notice in zlib.h
2746 /* inflate private state */
2747 struct internal_state {
2751 METHOD, /* waiting for method byte */
2752 FLAG, /* waiting for flag byte */
2753 BLOCKS, /* decompressing blocks */
2754 CHECK4, /* four check bytes to go */
2755 CHECK3, /* three check bytes to go */
2756 CHECK2, /* two check bytes to go */
2757 CHECK1, /* one check byte to go */
2758 DONE, /* finished check, done */
2759 BAD} /* got an error--stay here */
2760 mode; /* current inflate mode */
2762 /* mode dependent information */
2764 uInt method; /* if FLAGS, method byte */
2766 uLong was; /* computed check value */
2767 uLong need; /* stream check value */
2768 } check; /* if CHECK, check values to compare */
2769 uInt marker; /* if BAD, inflateSync's marker bytes count */
2770 } sub; /* submode */
2772 /* mode independent information */
2773 int nowrap; /* flag for no wrapper */
2774 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2775 inflate_blocks_statef
2776 *blocks; /* current inflate_blocks state */
2786 if (z == Z_NULL || z->state == Z_NULL)
2787 return Z_STREAM_ERROR;
2788 z->total_in = z->total_out = 0;
2790 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2791 inflate_blocks_reset(z->state->blocks, z, &c);
2792 Trace((stderr, "inflate: reset\n"));
2802 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2803 return Z_STREAM_ERROR;
2804 if (z->state->blocks != Z_NULL)
2805 inflate_blocks_free(z->state->blocks, z, &c);
2806 ZFREE(z, z->state, sizeof(struct internal_state));
2808 Trace((stderr, "inflate: end\n"));
2813 int inflateInit2(z, w)
2817 /* initialize state */
2819 return Z_STREAM_ERROR;
2820 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2821 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2822 if ((z->state = (struct internal_state FAR *)
2823 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2825 z->state->blocks = Z_NULL;
2827 /* handle undocumented nowrap option (no zlib header or check) */
2828 z->state->nowrap = 0;
2832 z->state->nowrap = 1;
2835 /* set window size */
2836 if (w < 8 || w > 15)
2839 return Z_STREAM_ERROR;
2841 z->state->wbits = (uInt)w;
2843 /* create inflate_blocks state */
2844 if ((z->state->blocks =
2845 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2851 Trace((stderr, "inflate: allocated\n"));
2862 return inflateInit2(z, DEF_WBITS);
2866 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2867 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2876 if (z == Z_NULL || z->next_in == Z_NULL)
2877 return Z_STREAM_ERROR;
2879 while (1) switch (z->state->mode)
2883 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2885 z->state->mode = BAD;
2886 z->msg = "unknown compression method";
2887 z->state->sub.marker = 5; /* can't try inflateSync */
2890 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2892 z->state->mode = BAD;
2893 z->msg = "invalid window size";
2894 z->state->sub.marker = 5; /* can't try inflateSync */
2897 z->state->mode = FLAG;
2900 if ((b = NEXTBYTE) & 0x20)
2902 z->state->mode = BAD;
2903 z->msg = "invalid reserved bit";
2904 z->state->sub.marker = 5; /* can't try inflateSync */
2907 if (((z->state->sub.method << 8) + b) % 31)
2909 z->state->mode = BAD;
2910 z->msg = "incorrect header check";
2911 z->state->sub.marker = 5; /* can't try inflateSync */
2914 Trace((stderr, "inflate: zlib header ok\n"));
2915 z->state->mode = BLOCKS;
2917 r = inflate_blocks(z->state->blocks, z, r);
2918 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2919 r = inflate_packet_flush(z->state->blocks);
2920 if (r == Z_DATA_ERROR)
2922 z->state->mode = BAD;
2923 z->state->sub.marker = 0; /* can try inflateSync */
2926 if (r != Z_STREAM_END)
2929 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2930 if (z->state->nowrap)
2932 z->state->mode = DONE;
2935 z->state->mode = CHECK4;
2938 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2939 z->state->mode = CHECK3;
2942 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2943 z->state->mode = CHECK2;
2946 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2947 z->state->mode = CHECK1;
2950 z->state->sub.check.need += (uLong)NEXTBYTE;
2952 if (z->state->sub.check.was != z->state->sub.check.need)
2954 z->state->mode = BAD;
2955 z->msg = "incorrect data check";
2956 z->state->sub.marker = 5; /* can't try inflateSync */
2959 Trace((stderr, "inflate: zlib check ok\n"));
2960 z->state->mode = DONE;
2962 return Z_STREAM_END;
2964 return Z_DATA_ERROR;
2966 return Z_STREAM_ERROR;
2970 if (f != Z_PACKET_FLUSH)
2972 z->state->mode = BAD;
2973 z->state->sub.marker = 0; /* can try inflateSync */
2974 return Z_DATA_ERROR;
2978 * This subroutine adds the data at next_in/avail_in to the output history
2979 * without performing any output. The output buffer must be "caught up";
2980 * i.e. no pending output (hence s->read equals s->write), and the state must
2981 * be BLOCKS (i.e. we should be willing to see the start of a series of
2982 * BLOCKS). On exit, the output will also be caught up, and the checksum
2983 * will have been updated if need be.
2986 int inflateIncomp(z)
2989 if (z->state->mode != BLOCKS)
2990 return Z_DATA_ERROR;
2991 return inflate_addhistory(z->state->blocks, z);
2998 uInt n; /* number of bytes to look at */
2999 Bytef *p; /* pointer to bytes */
3000 uInt m; /* number of marker bytes found in a row */
3001 uLong r, w; /* temporaries to save total_in and total_out */
3004 if (z == Z_NULL || z->state == Z_NULL)
3005 return Z_STREAM_ERROR;
3006 if (z->state->mode != BAD)
3008 z->state->mode = BAD;
3009 z->state->sub.marker = 0;
3011 if ((n = z->avail_in) == 0)
3014 m = z->state->sub.marker;
3019 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3029 z->total_in += p - z->next_in;
3032 z->state->sub.marker = m;
3034 /* return no joy or set up to restart on a new block */
3036 return Z_DATA_ERROR;
3037 r = z->total_in; w = z->total_out;
3039 z->total_in = r; z->total_out = w;
3040 z->state->mode = BLOCKS;
3048 /* infutil.h -- types and macros common to blocks and codes
3049 * Copyright (C) 1995 Mark Adler
3050 * For conditions of distribution and use, see copyright notice in zlib.h
3053 /* WARNING: this file should *not* be used by applications. It is
3054 part of the implementation of the compression library and is
3055 subject to change. Applications should only use zlib.h.
3058 /* inflate blocks semi-private state */
3059 struct inflate_blocks_state {
3063 TYPE, /* get type bits (3, including end bit) */
3064 LENS, /* get lengths for stored */
3065 STORED, /* processing stored block */
3066 TABLE, /* get table lengths */
3067 BTREE, /* get bit lengths tree for a dynamic block */
3068 DTREE, /* get length, distance trees for a dynamic block */
3069 CODES, /* processing fixed or dynamic block */
3070 DRY, /* output remaining window bytes */
3071 DONEB, /* finished last block, done */
3072 BADB} /* got a data error--stuck here */
3073 mode; /* current inflate_block mode */
3075 /* mode dependent information */
3077 uInt left; /* if STORED, bytes left to copy */
3079 uInt table; /* table lengths (14 bits) */
3080 uInt index; /* index into blens (or border) */
3081 uIntf *blens; /* bit lengths of codes */
3082 uInt bb; /* bit length tree depth */
3083 inflate_huft *tb; /* bit length decoding tree */
3084 int nblens; /* # elements allocated at blens */
3085 } trees; /* if DTREE, decoding info for trees */
3087 inflate_huft *tl, *td; /* trees to free */
3088 inflate_codes_statef
3090 } decode; /* if CODES, current state */
3091 } sub; /* submode */
3092 uInt last; /* true if this block is the last block */
3094 /* mode independent information */
3095 uInt bitk; /* bits in bit buffer */
3096 uLong bitb; /* bit buffer */
3097 Bytef *window; /* sliding window */
3098 Bytef *end; /* one byte after sliding window */
3099 Bytef *read; /* window read pointer */
3100 Bytef *write; /* window write pointer */
3101 check_func checkfn; /* check function */
3102 uLong check; /* check on output */
3107 /* defines for inflate input/output */
3108 /* update pointers and return */
3109 #define UPDBITS {s->bitb=b;s->bitk=k;}
3110 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3111 #define UPDOUT {s->write=q;}
3112 #define UPDATE {UPDBITS UPDIN UPDOUT}
3113 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3114 /* get bytes and bits */
3115 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3116 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3117 #define NEXTBYTE (n--,*p++)
3118 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3119 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3121 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3122 #define LOADOUT {q=s->write;m=WAVAIL;}
3123 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3124 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3125 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3126 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3127 /* load local pointers */
3128 #define LOAD {LOADIN LOADOUT}
3130 /* And'ing with mask[n] masks the lower n bits */
3131 local uInt inflate_mask[] = {
3133 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3134 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3137 /* copy as much as possible from the sliding window to the output area */
3138 local int inflate_flush OF((
3139 inflate_blocks_statef *,
3144 /* inffast.h -- header to use inffast.c
3145 * Copyright (C) 1995 Mark Adler
3146 * For conditions of distribution and use, see copyright notice in zlib.h
3149 /* WARNING: this file should *not* be used by applications. It is
3150 part of the implementation of the compression library and is
3151 subject to change. Applications should only use zlib.h.
3154 local int inflate_fast OF((
3159 inflate_blocks_statef *,
3164 /* infblock.c -- interpret and process block types to last block
3165 * Copyright (C) 1995 Mark Adler
3166 * For conditions of distribution and use, see copyright notice in zlib.h
3169 /* Table for deflate from PKZIP's appnote.txt. */
3170 local uInt border[] = { /* Order of the bit length code lengths */
3171 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3174 Notes beyond the 1.93a appnote.txt:
3176 1. Distance pointers never point before the beginning of the output
3178 2. Distance pointers can point back across blocks, up to 32k away.
3179 3. There is an implied maximum of 7 bits for the bit length table and
3180 15 bits for the actual data.
3181 4. If only one code exists, then it is encoded using one bit. (Zero
3182 would be more efficient, but perhaps a little confusing.) If two
3183 codes exist, they are coded using one bit each (0 and 1).
3184 5. There is no way of sending zero distance codes--a dummy must be
3185 sent if there are none. (History: a pre 2.0 version of PKZIP would
3186 store blocks with no distance codes, but this was discovered to be
3187 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3188 zero distance codes, which is sent as one code of zero bits in
3190 6. There are up to 286 literal/length codes. Code 256 represents the
3191 end-of-block. Note however that the static length tree defines
3192 288 codes just to fill out the Huffman codes. Codes 286 and 287
3193 cannot be used though, since there is no length base or extra bits
3194 defined for them. Similarily, there are up to 30 distance codes.
3195 However, static trees define 32 codes (all 5 bits) to fill out the
3196 Huffman codes, but the last two had better not show up in the data.
3197 7. Unzip can check dynamic Huffman blocks for complete code sets.
3198 The exception is that a single code would not be complete (see #4).
3199 8. The five bits following the block type is really the number of
3200 literal codes sent minus 257.
3201 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3202 (1+6+6). Therefore, to output three times the length, you output
3203 three codes (1+1+1), whereas to output four times the same length,
3204 you only need two codes (1+3). Hmm.
3205 10. In the tree reconstruction algorithm, Code = Code + Increment
3206 only if BitLength(i) is not zero. (Pretty obvious.)
3207 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3208 12. Note: length code 284 can represent 227-258, but length code 285
3209 really is 258. The last length deserves its own, short code
3210 since it gets used a lot in very redundant files. The length
3211 258 is special since 258 - 3 (the min match length) is 255.
3212 13. The literal/length and distance code bit lengths are read as a
3213 single stream of lengths. It is possible (and advantageous) for
3214 a repeat code (16, 17, or 18) to go across the boundary between
3215 the two sets of lengths.
3219 local void inflate_blocks_reset(s, z, c)
3220 inflate_blocks_statef *s;
3224 if (s->checkfn != Z_NULL)
3226 if (s->mode == BTREE || s->mode == DTREE)
3227 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3228 if (s->mode == CODES)
3230 inflate_codes_free(s->sub.decode.codes, z);
3231 inflate_trees_free(s->sub.decode.td, z);
3232 inflate_trees_free(s->sub.decode.tl, z);
3237 s->read = s->write = s->window;
3238 if (s->checkfn != Z_NULL)
3239 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3240 Trace((stderr, "inflate: blocks reset\n"));
3244 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
3249 inflate_blocks_statef *s;
3251 if ((s = (inflate_blocks_statef *)ZALLOC
3252 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3254 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3256 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3259 s->end = s->window + w;
3262 Trace((stderr, "inflate: blocks allocated\n"));
3263 inflate_blocks_reset(s, z, &s->check);
3268 local int inflate_blocks(s, z, r)
3269 inflate_blocks_statef *s;
3273 uInt t; /* temporary storage */
3274 uLong b; /* bit buffer */
3275 uInt k; /* bits in bit buffer */
3276 Bytef *p; /* input data pointer */
3277 uInt n; /* bytes available there */
3278 Bytef *q; /* output window write pointer */
3279 uInt m; /* bytes to end of window or read pointer */
3281 /* copy input/output information to locals (UPDATE macro restores) */
3284 /* process input based on current state */
3285 while (1) switch (s->mode)
3293 case 0: /* stored */
3294 Trace((stderr, "inflate: stored block%s\n",
3295 s->last ? " (last)" : ""));
3297 t = k & 7; /* go to byte boundary */
3299 s->mode = LENS; /* get length of stored block */
3302 Trace((stderr, "inflate: fixed codes block%s\n",
3303 s->last ? " (last)" : ""));
3306 inflate_huft *tl, *td;
3308 inflate_trees_fixed(&bl, &bd, &tl, &td);
3309 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3310 if (s->sub.decode.codes == Z_NULL)
3315 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3316 s->sub.decode.td = Z_NULL;
3321 case 2: /* dynamic */
3322 Trace((stderr, "inflate: dynamic codes block%s\n",
3323 s->last ? " (last)" : ""));
3327 case 3: /* illegal */
3330 z->msg = "invalid block type";
3337 if (((~b) >> 16) != (b & 0xffff))
3340 z->msg = "invalid stored block lengths";
3344 s->sub.left = (uInt)b & 0xffff;
3345 b = k = 0; /* dump bits */
3346 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3347 s->mode = s->sub.left ? STORED : TYPE;
3359 if ((s->sub.left -= t) != 0)
3361 Tracev((stderr, "inflate: stored end, %lu total out\n",
3362 z->total_out + (q >= s->read ? q - s->read :
3363 (s->end - s->read) + (q - s->window))));
3364 s->mode = s->last ? DRY : TYPE;
3368 s->sub.trees.table = t = (uInt)b & 0x3fff;
3369 #ifndef PKZIP_BUG_WORKAROUND
3370 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3373 z->msg = "too many length or distance symbols";
3378 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3381 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3386 s->sub.trees.nblens = t;
3388 s->sub.trees.index = 0;
3389 Tracev((stderr, "inflate: table sizes ok\n"));
3392 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3395 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3398 while (s->sub.trees.index < 19)
3399 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3400 s->sub.trees.bb = 7;
3401 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3402 &s->sub.trees.tb, z);
3406 if (r == Z_DATA_ERROR)
3410 s->sub.trees.index = 0;
3411 Tracev((stderr, "inflate: bits tree ok\n"));
3414 while (t = s->sub.trees.table,
3415 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3420 t = s->sub.trees.bb;
3422 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3423 t = h->word.what.Bits;
3428 s->sub.trees.blens[s->sub.trees.index++] = c;
3430 else /* c == 16..18 */
3432 i = c == 18 ? 7 : c - 14;
3433 j = c == 18 ? 11 : 3;
3436 j += (uInt)b & inflate_mask[i];
3438 i = s->sub.trees.index;
3439 t = s->sub.trees.table;
3440 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3444 z->msg = "invalid bit length repeat";
3448 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3450 s->sub.trees.blens[i++] = c;
3452 s->sub.trees.index = i;
3455 inflate_trees_free(s->sub.trees.tb, z);
3456 s->sub.trees.tb = Z_NULL;
3459 inflate_huft *tl, *td;
3460 inflate_codes_statef *c;
3462 bl = 9; /* must be <= 9 for lookahead assumptions */
3463 bd = 6; /* must be <= 9 for lookahead assumptions */
3464 t = s->sub.trees.table;
3465 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3466 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3469 if (t == (uInt)Z_DATA_ERROR)
3474 Tracev((stderr, "inflate: trees ok\n"));
3475 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3477 inflate_trees_free(td, z);
3478 inflate_trees_free(tl, z);
3482 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3483 s->sub.decode.codes = c;
3484 s->sub.decode.tl = tl;
3485 s->sub.decode.td = td;
3490 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3491 return inflate_flush(s, z, r);
3493 inflate_codes_free(s->sub.decode.codes, z);
3494 inflate_trees_free(s->sub.decode.td, z);
3495 inflate_trees_free(s->sub.decode.tl, z);
3497 Tracev((stderr, "inflate: codes end, %lu total out\n",
3498 z->total_out + (q >= s->read ? q - s->read :
3499 (s->end - s->read) + (q - s->window))));
3505 if (k > 7) /* return unused byte, if any */
3507 Assert(k < 16, "inflate_codes grabbed too many bytes")
3510 p--; /* can always return one */
3515 if (s->read != s->write)
3531 local int inflate_blocks_free(s, z, c)
3532 inflate_blocks_statef *s;
3536 inflate_blocks_reset(s, z, c);
3537 ZFREE(z, s->window, s->end - s->window);
3538 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3539 Trace((stderr, "inflate: blocks freed\n"));
3544 * This subroutine adds the data at next_in/avail_in to the output history
3545 * without performing any output. The output buffer must be "caught up";
3546 * i.e. no pending output (hence s->read equals s->write), and the state must
3547 * be BLOCKS (i.e. we should be willing to see the start of a series of
3548 * BLOCKS). On exit, the output will also be caught up, and the checksum
3549 * will have been updated if need be.
3551 local int inflate_addhistory(s, z)
3552 inflate_blocks_statef *s;
3555 uLong b; /* bit buffer */ /* NOT USED HERE */
3556 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3557 uInt t; /* temporary storage */
3558 Bytef *p; /* input data pointer */
3559 uInt n; /* bytes available there */
3560 Bytef *q; /* output window write pointer */
3561 uInt m; /* bytes to end of window or read pointer */
3563 if (s->read != s->write)
3564 return Z_STREAM_ERROR;
3565 if (s->mode != TYPE)
3566 return Z_DATA_ERROR;
3568 /* we're ready to rock */
3570 /* while there is input ready, copy to output buffer, moving
3571 * pointers as needed.
3574 t = n; /* how many to do */
3575 /* is there room until end of buffer? */
3577 /* update check information */
3578 if (s->checkfn != Z_NULL)
3579 s->check = (*s->checkfn)(s->check, q, t);
3585 s->read = q; /* drag read pointer forward */
3586 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
3588 s->read = q = s->window;
3598 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3599 * a `stored' block type value but not the (zero) length bytes.
3601 local int inflate_packet_flush(s)
3602 inflate_blocks_statef *s;
3604 if (s->mode != LENS)
3605 return Z_DATA_ERROR;
3612 /* inftrees.c -- generate Huffman trees for efficient decoding
3613 * Copyright (C) 1995 Mark Adler
3614 * For conditions of distribution and use, see copyright notice in zlib.h
3617 /* simplify the use of the inflate_huft type with some defines */
3618 #define base more.Base
3619 #define next more.Next
3620 #define exop word.what.Exop
3621 #define bits word.what.Bits
3624 local int huft_build OF((
3625 uIntf *, /* code lengths in bits */
3626 uInt, /* number of codes */
3627 uInt, /* number of "simple" codes */
3628 uIntf *, /* list of base values for non-simple codes */
3629 uIntf *, /* list of extra bits for non-simple codes */
3630 inflate_huft * FAR*,/* result: starting table */
3631 uIntf *, /* maximum lookup bits (returns actual) */
3632 z_stream *)); /* for zalloc function */
3634 local voidpf falloc OF((
3635 voidpf, /* opaque pointer (not used) */
3636 uInt, /* number of items */
3637 uInt)); /* size of item */
3639 local void ffree OF((
3640 voidpf q, /* opaque pointer (not used) */
3641 voidpf p, /* what to free (not used) */
3642 uInt n)); /* number of bytes (not used) */
3644 /* Tables for deflate from PKZIP's appnote.txt. */
3645 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3646 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3647 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3648 /* actually lengths - 2; also see note #13 above about 258 */
3649 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3650 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3651 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3652 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3653 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3654 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3655 8193, 12289, 16385, 24577};
3656 local uInt cpdext[] = { /* Extra bits for distance codes */
3657 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3658 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3662 Huffman code decoding is performed using a multi-level table lookup.
3663 The fastest way to decode is to simply build a lookup table whose
3664 size is determined by the longest code. However, the time it takes
3665 to build this table can also be a factor if the data being decoded
3666 is not very long. The most common codes are necessarily the
3667 shortest codes, so those codes dominate the decoding time, and hence
3668 the speed. The idea is you can have a shorter table that decodes the
3669 shorter, more probable codes, and then point to subsidiary tables for
3670 the longer codes. The time it costs to decode the longer codes is
3671 then traded against the time it takes to make longer tables.
3673 This results of this trade are in the variables lbits and dbits
3674 below. lbits is the number of bits the first level table for literal/
3675 length codes can decode in one step, and dbits is the same thing for
3676 the distance codes. Subsequent tables are also less than or equal to
3677 those sizes. These values may be adjusted either when all of the
3678 codes are shorter than that, in which case the longest code length in
3679 bits is used, or when the shortest code is *longer* than the requested
3680 table size, in which case the length of the shortest code in bits is
3683 There are two different values for the two tables, since they code a
3684 different number of possibilities each. The literal/length table
3685 codes 286 possible values, or in a flat code, a little over eight
3686 bits. The distance table codes 30 possible values, or a little less
3687 than five bits, flat. The optimum values for speed end up being
3688 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3689 The optimum values may differ though from machine to machine, and
3690 possibly even between compilers. Your mileage may vary.
3694 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3695 #define BMAX 15 /* maximum bit length of any code */
3696 #define N_MAX 288 /* maximum number of codes in any set */
3702 local int huft_build(b, n, s, d, e, t, m, zs)
3703 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3704 uInt n; /* number of codes (assumed <= N_MAX) */
3705 uInt s; /* number of simple-valued codes (0..s-1) */
3706 uIntf *d; /* list of base values for non-simple codes */
3707 uIntf *e; /* list of extra bits for non-simple codes */
3708 inflate_huft * FAR *t; /* result: starting table */
3709 uIntf *m; /* maximum lookup bits, returns actual */
3710 z_stream *zs; /* for zalloc function */
3711 /* Given a list of code lengths and a maximum table size, make a set of
3712 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3713 if the given code set is incomplete (the tables are still built in this
3714 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3715 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3718 uInt a; /* counter for codes of length k */
3719 uInt c[BMAX+1]; /* bit length count table */
3720 uInt f; /* i repeats in table every f entries */
3721 int g; /* maximum code length */
3722 int h; /* table level */
3723 register uInt i; /* counter, current code */
3724 register uInt j; /* counter */
3725 register int k; /* number of bits in current code */
3726 int l; /* bits per table (returned in m) */
3727 register uIntf *p; /* pointer into c[], b[], or v[] */
3728 inflate_huft *q; /* points to current table */
3729 struct inflate_huft_s r; /* table entry for structure assignment */
3730 inflate_huft *u[BMAX]; /* table stack */
3731 uInt v[N_MAX]; /* values in order of bit length */
3732 register int w; /* bits before this table == (l * h) */
3733 uInt x[BMAX+1]; /* bit offsets, then code stack */
3734 uIntf *xp; /* pointer into x */
3735 int y; /* number of dummy codes added */
3736 uInt z; /* number of entries in current table */
3739 /* Generate counts for each bit length */
3741 #define C0 *p++ = 0;
3742 #define C2 C0 C0 C0 C0
3743 #define C4 C2 C2 C2 C2
3744 C4 /* clear c[]--assume BMAX+1 is 16 */
3747 c[*p++]++; /* assume all entries <= BMAX */
3749 if (c[0] == n) /* null input--all zero length codes */
3751 *t = (inflate_huft *)Z_NULL;
3757 /* Find minimum and maximum length, bound *m by those */
3759 for (j = 1; j <= BMAX; j++)
3762 k = j; /* minimum code length */
3765 for (i = BMAX; i; i--)
3768 g = i; /* maximum code length */
3774 /* Adjust last length count to fill out codes, if needed */
3775 for (y = 1 << j; j < i; j++, y <<= 1)
3776 if ((y -= c[j]) < 0)
3777 return Z_DATA_ERROR;
3778 if ((y -= c[i]) < 0)
3779 return Z_DATA_ERROR;
3783 /* Generate starting offsets into the value table for each length */
3785 p = c + 1; xp = x + 2;
3786 while (--i) { /* note that i == g from above */
3787 *xp++ = (j += *p++);
3791 /* Make a table of values in order of bit lengths */
3794 if ((j = *p++) != 0)
3799 /* Generate the Huffman codes and for each, make the table entries */
3800 x[0] = i = 0; /* first Huffman code is zero */
3801 p = v; /* grab values in bit order */
3802 h = -1; /* no tables yet--level -1 */
3803 w = -l; /* bits decoded == (l * h) */
3804 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3805 q = (inflate_huft *)Z_NULL; /* ditto */
3808 /* go through the bit lengths (k already is bits in shortest code) */
3814 /* here i is the Huffman code of length k bits for value *p */
3815 /* make tables up to required level */
3819 w += l; /* previous table always l bits */
3821 /* compute minimum size table less than or equal to l bits */
3822 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3823 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3824 { /* too few codes for k-w bit table */
3825 f -= a + 1; /* deduct codes from patterns left */
3828 while (++j < z) /* try smaller tables up to z bits */
3830 if ((f <<= 1) <= *++xp)
3831 break; /* enough codes to use up j bits */
3832 f -= *xp; /* else deduct codes from patterns */
3835 z = 1 << j; /* table entries for j-bit table */
3837 /* allocate and link in new table */
3838 if ((q = (inflate_huft *)ZALLOC
3839 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3842 inflate_trees_free(u[0], zs);
3843 return Z_MEM_ERROR; /* not enough memory */
3845 q->word.Nalloc = z + 1;
3847 inflate_hufts += z + 1;
3849 *t = q + 1; /* link to list for huft_free() */
3850 *(t = &(q->next)) = Z_NULL;
3851 u[h] = ++q; /* table starts after link */
3853 /* connect to last table, if there is one */
3856 x[h] = i; /* save pattern for backing up */
3857 r.bits = (Byte)l; /* bits to dump before this table */
3858 r.exop = (Byte)j; /* bits in this table */
3859 r.next = q; /* pointer to this table */
3860 j = i >> (w - l); /* (get around Turbo C bug) */
3861 u[h-1][j] = r; /* connect to last table */
3865 /* set up table entry in r */
3866 r.bits = (Byte)(k - w);
3868 r.exop = 128 + 64; /* out of values--invalid code */
3871 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3872 r.base = *p++; /* simple code is just the value */
3876 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3877 r.base = d[*p++ - s];
3880 /* fill code-like entries with r */
3882 for (j = i >> w; j < z; j += f)
3885 /* backwards increment the k-bit code i */
3886 for (j = 1 << (k - 1); i & j; j >>= 1)
3890 /* backup over finished tables */
3891 while ((i & ((1 << w) - 1)) != x[h])
3893 h--; /* don't need to update q */
3900 /* Return Z_BUF_ERROR if we were given an incomplete table */
3901 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3905 local int inflate_trees_bits(c, bb, tb, z)
3906 uIntf *c; /* 19 code lengths */
3907 uIntf *bb; /* bits tree desired/actual depth */
3908 inflate_huft * FAR *tb; /* bits tree result */
3909 z_stream *z; /* for zfree function */
3913 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3914 if (r == Z_DATA_ERROR)
3915 z->msg = "oversubscribed dynamic bit lengths tree";
3916 else if (r == Z_BUF_ERROR)
3918 inflate_trees_free(*tb, z);
3919 z->msg = "incomplete dynamic bit lengths tree";
3926 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3927 uInt nl; /* number of literal/length codes */
3928 uInt nd; /* number of distance codes */
3929 uIntf *c; /* that many (total) code lengths */
3930 uIntf *bl; /* literal desired/actual bit depth */
3931 uIntf *bd; /* distance desired/actual bit depth */
3932 inflate_huft * FAR *tl; /* literal/length tree result */
3933 inflate_huft * FAR *td; /* distance tree result */
3934 z_stream *z; /* for zfree function */
3938 /* build literal/length tree */
3939 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3941 if (r == Z_DATA_ERROR)
3942 z->msg = "oversubscribed literal/length tree";
3943 else if (r == Z_BUF_ERROR)
3945 inflate_trees_free(*tl, z);
3946 z->msg = "incomplete literal/length tree";
3952 /* build distance tree */
3953 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3955 if (r == Z_DATA_ERROR)
3956 z->msg = "oversubscribed literal/length tree";
3957 else if (r == Z_BUF_ERROR) {
3958 #ifdef PKZIP_BUG_WORKAROUND
3962 inflate_trees_free(*td, z);
3963 z->msg = "incomplete literal/length tree";
3966 inflate_trees_free(*tl, z);
3976 /* build fixed tables only once--keep them here */
3977 local int fixed_lock = 0;
3978 local int fixed_built = 0;
3979 #define FIXEDH 530 /* number of hufts used by fixed tables */
3980 local uInt fixed_left = FIXEDH;
3981 local inflate_huft fixed_mem[FIXEDH];
3982 local uInt fixed_bl;
3983 local uInt fixed_bd;
3984 local inflate_huft *fixed_tl;
3985 local inflate_huft *fixed_td;
3988 local voidpf falloc(q, n, s)
3989 voidpf q; /* opaque pointer (not used) */
3990 uInt n; /* number of items */
3991 uInt s; /* size of item */
3993 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
3994 "inflate_trees falloc overflow");
3995 if (q) s++; /* to make some compilers happy */
3997 return (voidpf)(fixed_mem + fixed_left);
4001 local void ffree(q, p, n)
4006 Assert(0, "inflate_trees ffree called!");
4007 if (q) q = p; /* to make some compilers happy */
4011 local int inflate_trees_fixed(bl, bd, tl, td)
4012 uIntf *bl; /* literal desired/actual bit depth */
4013 uIntf *bd; /* distance desired/actual bit depth */
4014 inflate_huft * FAR *tl; /* literal/length tree result */
4015 inflate_huft * FAR *td; /* distance tree result */
4017 /* build fixed tables if not built already--lock out other instances */
4018 while (++fixed_lock > 1)
4022 int k; /* temporary variable */
4023 unsigned c[288]; /* length list for huft_build */
4024 z_stream z; /* for falloc function */
4026 /* set up fake z_stream for memory routines */
4032 for (k = 0; k < 144; k++)
4034 for (; k < 256; k++)
4036 for (; k < 280; k++)
4038 for (; k < 288; k++)
4041 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4043 /* distance table */
4044 for (k = 0; k < 30; k++)
4047 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4061 local int inflate_trees_free(t, z)
4062 inflate_huft *t; /* table to free */
4063 z_stream *z; /* for zfree function */
4064 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4065 list of the tables it made, with the links in a dummy first entry of
4068 register inflate_huft *p, *q;
4070 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4075 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4082 /* infcodes.c -- process literals and length/distance pairs
4083 * Copyright (C) 1995 Mark Adler
4084 * For conditions of distribution and use, see copyright notice in zlib.h
4087 /* simplify the use of the inflate_huft type with some defines */
4088 #define base more.Base
4089 #define next more.Next
4090 #define exop word.what.Exop
4091 #define bits word.what.Bits
4093 /* inflate codes private state */
4094 struct inflate_codes_state {
4097 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4098 START, /* x: set up for LEN */
4099 LEN, /* i: get length/literal/eob next */
4100 LENEXT, /* i: getting length extra (have base) */
4101 DIST, /* i: get distance next */
4102 DISTEXT, /* i: getting distance extra */
4103 COPY, /* o: copying bytes in window, waiting for space */
4104 LIT, /* o: got literal, waiting for output space */
4105 WASH, /* o: got eob, possibly still output waiting */
4106 END, /* x: got eob and all data flushed */
4107 BADCODE} /* x: got error */
4108 mode; /* current inflate_codes mode */
4110 /* mode dependent information */
4114 inflate_huft *tree; /* pointer into tree */
4115 uInt need; /* bits needed */
4116 } code; /* if LEN or DIST, where in tree */
4117 uInt lit; /* if LIT, literal */
4119 uInt get; /* bits to get for extra */
4120 uInt dist; /* distance back to copy from */
4121 } copy; /* if EXT or COPY, where and how much */
4122 } sub; /* submode */
4124 /* mode independent information */
4125 Byte lbits; /* ltree bits decoded per branch */
4126 Byte dbits; /* dtree bits decoder per branch */
4127 inflate_huft *ltree; /* literal/length/eob tree */
4128 inflate_huft *dtree; /* distance tree */
4133 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4135 inflate_huft *tl, *td;
4138 inflate_codes_statef *c;
4140 if ((c = (inflate_codes_statef *)
4141 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4144 c->lbits = (Byte)bl;
4145 c->dbits = (Byte)bd;
4148 Tracev((stderr, "inflate: codes new\n"));
4154 local int inflate_codes(s, z, r)
4155 inflate_blocks_statef *s;
4159 uInt j; /* temporary storage */
4160 inflate_huft *t; /* temporary pointer */
4161 uInt e; /* extra bits or operation */
4162 uLong b; /* bit buffer */
4163 uInt k; /* bits in bit buffer */
4164 Bytef *p; /* input data pointer */
4165 uInt n; /* bytes available there */
4166 Bytef *q; /* output window write pointer */
4167 uInt m; /* bytes to end of window or read pointer */
4168 Bytef *f; /* pointer to copy strings from */
4169 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4171 /* copy input/output information to locals (UPDATE macro restores) */
4174 /* process input and output based on current state */
4175 while (1) switch (c->mode)
4176 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4177 case START: /* x: set up for LEN */
4179 if (m >= 258 && n >= 10)
4182 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4186 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4191 c->sub.code.need = c->lbits;
4192 c->sub.code.tree = c->ltree;
4194 case LEN: /* i: get length/literal/eob next */
4195 j = c->sub.code.need;
4197 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4199 e = (uInt)(t->exop);
4200 if (e == 0) /* literal */
4202 c->sub.lit = t->base;
4203 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4204 "inflate: literal '%c'\n" :
4205 "inflate: literal 0x%02x\n", t->base));
4209 if (e & 16) /* length */
4211 c->sub.copy.get = e & 15;
4216 if ((e & 64) == 0) /* next table */
4218 c->sub.code.need = e;
4219 c->sub.code.tree = t->next;
4222 if (e & 32) /* end of block */
4224 Tracevv((stderr, "inflate: end of block\n"));
4228 c->mode = BADCODE; /* invalid code */
4229 z->msg = "invalid literal/length code";
4232 case LENEXT: /* i: getting length extra (have base) */
4233 j = c->sub.copy.get;
4235 c->len += (uInt)b & inflate_mask[j];
4237 c->sub.code.need = c->dbits;
4238 c->sub.code.tree = c->dtree;
4239 Tracevv((stderr, "inflate: length %u\n", c->len));
4241 case DIST: /* i: get distance next */
4242 j = c->sub.code.need;
4244 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4246 e = (uInt)(t->exop);
4247 if (e & 16) /* distance */
4249 c->sub.copy.get = e & 15;
4250 c->sub.copy.dist = t->base;
4254 if ((e & 64) == 0) /* next table */
4256 c->sub.code.need = e;
4257 c->sub.code.tree = t->next;
4260 c->mode = BADCODE; /* invalid code */
4261 z->msg = "invalid distance code";
4264 case DISTEXT: /* i: getting distance extra */
4265 j = c->sub.copy.get;
4267 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4269 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4271 case COPY: /* o: copying bytes in window, waiting for space */
4272 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4273 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4274 s->end - (c->sub.copy.dist - (q - s->window)) :
4275 q - c->sub.copy.dist;
4277 f = q - c->sub.copy.dist;
4278 if ((uInt)(q - s->window) < c->sub.copy.dist)
4279 f = s->end - (c->sub.copy.dist - (q - s->window));
4291 case LIT: /* o: got literal, waiting for output space */
4296 case WASH: /* o: got eob, possibly more output */
4298 if (s->read != s->write)
4304 case BADCODE: /* x: got error */
4314 local void inflate_codes_free(c, z)
4315 inflate_codes_statef *c;
4318 ZFREE(z, c, sizeof(struct inflate_codes_state));
4319 Tracev((stderr, "inflate: codes free\n"));
4323 /* inflate_util.c -- data and routines common to blocks and codes
4324 * Copyright (C) 1995 Mark Adler
4325 * For conditions of distribution and use, see copyright notice in zlib.h
4328 /* copy as much as possible from the sliding window to the output area */
4329 local int inflate_flush(s, z, r)
4330 inflate_blocks_statef *s;
4337 /* local copies of source and destination pointers */
4341 /* compute number of bytes to copy as far as end of window */
4342 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4343 if (n > z->avail_out) n = z->avail_out;
4344 if (n && r == Z_BUF_ERROR) r = Z_OK;
4346 /* update counters */
4350 /* update check information */
4351 if (s->checkfn != Z_NULL)
4352 s->check = (*s->checkfn)(s->check, q, n);
4354 /* copy as far as end of window */
4361 /* see if more to copy at beginning of window */
4366 if (s->write == s->end)
4367 s->write = s->window;
4369 /* compute bytes to copy */
4370 n = (uInt)(s->write - q);
4371 if (n > z->avail_out) n = z->avail_out;
4372 if (n && r == Z_BUF_ERROR) r = Z_OK;
4374 /* update counters */
4378 /* update check information */
4379 if (s->checkfn != Z_NULL)
4380 s->check = (*s->checkfn)(s->check, q, n);
4390 /* update pointers */
4400 /* inffast.c -- process literals and length/distance pairs fast
4401 * Copyright (C) 1995 Mark Adler
4402 * For conditions of distribution and use, see copyright notice in zlib.h
4405 /* simplify the use of the inflate_huft type with some defines */
4406 #define base more.Base
4407 #define next more.Next
4408 #define exop word.what.Exop
4409 #define bits word.what.Bits
4411 /* macros for bit input with no checking and for returning unused bytes */
4412 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4413 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4415 /* Called with number of bytes left to write in window at least 258
4416 (the maximum string length) and number of input bytes available
4417 at least ten. The ten bytes are six bytes for the longest length/
4418 distance pair plus four bytes for overloading the bit buffer. */
4420 local int inflate_fast(bl, bd, tl, td, s, z)
4422 inflate_huft *tl, *td;
4423 inflate_blocks_statef *s;
4426 inflate_huft *t; /* temporary pointer */
4427 uInt e; /* extra bits or operation */
4428 uLong b; /* bit buffer */
4429 uInt k; /* bits in bit buffer */
4430 Bytef *p; /* input data pointer */
4431 uInt n; /* bytes available there */
4432 Bytef *q; /* output window write pointer */
4433 uInt m; /* bytes to end of window or read pointer */
4434 uInt ml; /* mask for literal/length tree */
4435 uInt md; /* mask for distance tree */
4436 uInt c; /* bytes to copy */
4437 uInt d; /* distance back to copy from */
4438 Bytef *r; /* copy source pointer */
4440 /* load input, output, bit values */
4443 /* initialize masks */
4444 ml = inflate_mask[bl];
4445 md = inflate_mask[bd];
4447 /* do until not enough input or output space for fast loop */
4448 do { /* assume called with m >= 258 && n >= 10 */
4449 /* get literal/length code */
4450 GRABBITS(20) /* max bits for literal/length code */
4451 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4454 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4455 "inflate: * literal '%c'\n" :
4456 "inflate: * literal 0x%02x\n", t->base));
4457 *q++ = (Byte)t->base;
4465 /* get extra bits for length */
4467 c = t->base + ((uInt)b & inflate_mask[e]);
4469 Tracevv((stderr, "inflate: * length %u\n", c));
4471 /* decode distance base of block to copy */
4472 GRABBITS(15); /* max bits for distance code */
4473 e = (t = td + ((uInt)b & md))->exop;
4478 /* get extra bits to add to distance base */
4480 GRABBITS(e) /* get extra bits (up to 13) */
4481 d = t->base + ((uInt)b & inflate_mask[e]);
4483 Tracevv((stderr, "inflate: * distance %u\n", d));
4487 if ((uInt)(q - s->window) >= d) /* offset before dest */
4490 *q++ = *r++; c--; /* minimum count is three, */
4491 *q++ = *r++; c--; /* so unroll loop a little */
4493 else /* else offset after destination */
4495 e = d - (q - s->window); /* bytes from offset to end */
4496 r = s->end - e; /* pointer to offset */
4497 if (c > e) /* if source crosses, */
4499 c -= e; /* copy to end of window */
4503 r = s->window; /* copy rest from start of window */
4506 do { /* copy all or what's left */
4511 else if ((e & 64) == 0)
4512 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4515 z->msg = "invalid distance code";
4518 return Z_DATA_ERROR;
4525 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4528 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4529 "inflate: * literal '%c'\n" :
4530 "inflate: * literal 0x%02x\n", t->base));
4531 *q++ = (Byte)t->base;
4538 Tracevv((stderr, "inflate: * end of block\n"));
4541 return Z_STREAM_END;
4545 z->msg = "invalid literal/length code";
4548 return Z_DATA_ERROR;
4551 } while (m >= 258 && n >= 10);
4553 /* not enough input or output--restore pointers and return */
4561 /* zutil.c -- target dependent utility functions for the compression library
4562 * Copyright (C) 1995 Jean-loup Gailly.
4563 * For conditions of distribution and use, see copyright notice in zlib.h
4566 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
4568 char *zlib_version = ZLIB_VERSION;
4570 char *z_errmsg[] = {
4571 "stream end", /* Z_STREAM_END 1 */
4573 "file error", /* Z_ERRNO (-1) */
4574 "stream error", /* Z_STREAM_ERROR (-2) */
4575 "data error", /* Z_DATA_ERROR (-3) */
4576 "insufficient memory", /* Z_MEM_ERROR (-4) */
4577 "buffer error", /* Z_BUF_ERROR (-5) */
4582 /* adler32.c -- compute the Adler-32 checksum of a data stream
4583 * Copyright (C) 1995 Mark Adler
4584 * For conditions of distribution and use, see copyright notice in zlib.h
4587 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
4589 #define BASE 65521L /* largest prime smaller than 65536 */
4591 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4593 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4594 #define DO2(buf) DO1(buf); DO1(buf);
4595 #define DO4(buf) DO2(buf); DO2(buf);
4596 #define DO8(buf) DO4(buf); DO4(buf);
4597 #define DO16(buf) DO8(buf); DO8(buf);
4599 /* ========================================================================= */
4600 uLong adler32(adler, buf, len)
4605 unsigned long s1 = adler & 0xffff;
4606 unsigned long s2 = (adler >> 16) & 0xffff;
4609 if (buf == Z_NULL) return 1L;
4612 k = len < NMAX ? len : NMAX;
4624 return (s2 << 16) | s1;