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 */
39 /* compile with -Dlocal if your debugger can't find static symbols */
43 typedef unsigned char uch;
45 typedef unsigned short ush;
47 typedef unsigned int ulg;
49 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
51 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
52 /* To be used only when the state is known to be valid */
55 #define NULL ((void *) 0)
58 /* common constants */
63 # define DEF_WBITS MAX_WBITS
65 /* default windowBits for decompression. MAX_WBITS is for compression only */
67 #if MAX_MEM_LEVEL >= 8
68 # define DEF_MEM_LEVEL 8
70 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
72 /* default memLevel */
74 #define STORED_BLOCK 0
75 #define STATIC_TREES 1
77 /* The three kinds of block type */
81 /* The minimum and maximum match lengths */
84 #define zmemcpy(d, s, n) bcopy((s), (d), (n))
85 #define zmemzero bzero
87 /* Diagnostic functions */
93 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
94 # define Trace(x) fprintf x
95 # define Tracev(x) {if (verbose) fprintf x ;}
96 # define Tracevv(x) {if (verbose>1) fprintf x ;}
97 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
98 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
100 # define Assert(cond,msg)
105 # define Tracecv(c,x)
109 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
111 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
112 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
114 #define ZALLOC(strm, items, size) \
115 (*((strm)->zalloc))((strm)->opaque, (items), (size))
116 #define ZFREE(strm, addr, size) \
117 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
118 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
120 /* deflate.h -- internal compression state
121 * Copyright (C) 1995 Jean-loup Gailly
122 * For conditions of distribution and use, see copyright notice in zlib.h
125 /* WARNING: this file should *not* be used by applications. It is
126 part of the implementation of the compression library and is
127 subject to change. Applications should only use zlib.h.
132 /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */
134 /* ===========================================================================
135 * Internal compression state.
143 #define LENGTH_CODES 29
144 /* number of length codes, not counting the special END_BLOCK code */
147 /* number of literal bytes 0..255 */
149 #define L_CODES (LITERALS+1+LENGTH_CODES)
150 /* number of Literal or Length codes, including the END_BLOCK code */
153 /* number of distance codes */
156 /* number of codes used to transfer the bit lengths */
158 #define HEAP_SIZE (2*L_CODES+1)
159 /* maximum heap size */
162 /* All codes must not exceed MAX_BITS bits */
164 #define INIT_STATE 42
165 #define BUSY_STATE 113
166 #define FLUSH_STATE 124
167 #define FINISH_STATE 666
171 /* Data structure describing a single value and its code string. */
172 typedef struct ct_data_s {
174 ush freq; /* frequency count */
175 ush code; /* bit string */
178 ush dad; /* father node in Huffman tree */
179 ush len; /* length of bit string */
188 typedef struct static_tree_desc_s static_tree_desc;
190 typedef struct tree_desc_s {
191 ct_data *dyn_tree; /* the dynamic tree */
192 int max_code; /* largest code with non zero frequency */
193 static_tree_desc *stat_desc; /* the corresponding static tree */
197 typedef Pos FAR Posf;
198 typedef unsigned IPos;
200 /* A Pos is an index in the character window. We use short instead of int to
201 * save space in the various tables. IPos is used only for parameter passing.
204 typedef struct deflate_state {
205 z_stream *strm; /* pointer back to this zlib stream */
206 int status; /* as the name implies */
207 Bytef *pending_buf; /* output still pending */
208 Bytef *pending_out; /* next pending byte to output to the stream */
209 int pending; /* nb of bytes in the pending buffer */
210 uLong adler; /* adler32 of uncompressed data */
211 int noheader; /* suppress zlib header and adler32 */
212 Byte data_type; /* UNKNOWN, BINARY or ASCII */
213 Byte method; /* STORED (for zip only) or DEFLATED */
214 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */
216 /* used by deflate.c: */
218 uInt w_size; /* LZ77 window size (32K by default) */
219 uInt w_bits; /* log2(w_size) (8..16) */
220 uInt w_mask; /* w_size - 1 */
223 /* Sliding window. Input bytes are read into the second half of the window,
224 * and move to the first half later to keep a dictionary of at least wSize
225 * bytes. With this organization, matches are limited to a distance of
226 * wSize-MAX_MATCH bytes, but this ensures that IO is always
227 * performed with a length multiple of the block size. Also, it limits
228 * the window size to 64K, which is quite useful on MSDOS.
229 * To do: use the user input buffer as sliding window.
233 /* Actual size of window: 2*wSize, except when the user input buffer
234 * is directly used as sliding window.
238 /* Link to older string with same hash index. To limit the size of this
239 * array to 64K, this link is maintained only for the last 32K strings.
240 * An index in this array is thus a window index modulo 32K.
243 Posf *head; /* Heads of the hash chains or NIL. */
245 uInt ins_h; /* hash index of string to be inserted */
246 uInt hash_size; /* number of elements in hash table */
247 uInt hash_bits; /* log2(hash_size) */
248 uInt hash_mask; /* hash_size-1 */
251 /* Number of bits by which ins_h must be shifted at each input
252 * step. It must be such that after MIN_MATCH steps, the oldest
253 * byte no longer takes part in the hash key, that is:
254 * hash_shift * MIN_MATCH >= hash_bits
258 /* Window position at the beginning of the current output block. Gets
259 * negative when the window is moved backwards.
262 uInt match_length; /* length of best match */
263 IPos prev_match; /* previous match */
264 int match_available; /* set if previous match exists */
265 uInt strstart; /* start of string to insert */
266 uInt match_start; /* start of matching string */
267 uInt lookahead; /* number of valid bytes ahead in window */
270 /* Length of the best match at previous step. Matches not greater than this
271 * are discarded. This is used in the lazy match evaluation.
274 uInt max_chain_length;
275 /* To speed up deflation, hash chains are never searched beyond this
276 * length. A higher limit improves compression ratio but degrades the
281 /* Attempt to find a better match only when the current match is strictly
282 * smaller than this value. This mechanism is used only for compression
285 # define max_insert_length max_lazy_match
286 /* Insert new strings in the hash table only if the match length is not
287 * greater than this length. This saves time but degrades compression.
288 * max_insert_length is used only for compression levels <= 3.
291 int level; /* compression level (1..9) */
292 int strategy; /* favor or force Huffman coding*/
295 /* Use a faster search when the previous match is longer than this */
297 int nice_match; /* Stop searching when current match exceeds this */
299 /* used by trees.c: */
300 /* Didn't use ct_data typedef below to supress compiler warning */
301 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
302 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
303 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
305 struct tree_desc_s l_desc; /* desc. for literal tree */
306 struct tree_desc_s d_desc; /* desc. for distance tree */
307 struct tree_desc_s bl_desc; /* desc. for bit length tree */
309 ush bl_count[MAX_BITS+1];
310 /* number of codes at each bit length for an optimal tree */
312 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
313 int heap_len; /* number of elements in the heap */
314 int heap_max; /* element of largest frequency */
315 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
316 * The same heap array is used to build all trees.
319 uch depth[2*L_CODES+1];
320 /* Depth of each subtree used as tie breaker for trees of equal frequency
323 uchf *l_buf; /* buffer for literals or lengths */
326 /* Size of match buffer for literals/lengths. There are 4 reasons for
327 * limiting lit_bufsize to 64K:
328 * - frequencies can be kept in 16 bit counters
329 * - if compression is not successful for the first block, all input
330 * data is still in the window so we can still emit a stored block even
331 * when input comes from standard input. (This can also be done for
332 * all blocks if lit_bufsize is not greater than 32K.)
333 * - if compression is not successful for a file smaller than 64K, we can
334 * even emit a stored file instead of a stored block (saving 5 bytes).
335 * This is applicable only for zip (not gzip or zlib).
336 * - creating new Huffman trees less frequently may not provide fast
337 * adaptation to changes in the input data statistics. (Take for
338 * example a binary file with poorly compressible code followed by
339 * a highly compressible string table.) Smaller buffer sizes give
340 * fast adaptation but have of course the overhead of transmitting
341 * trees more frequently.
342 * - I can't count above 4
345 uInt last_lit; /* running index in l_buf */
348 /* Buffer for distances. To simplify the code, d_buf and l_buf have
349 * the same number of elements. To use different lengths, an extra flag
350 * array would be necessary.
353 ulg opt_len; /* bit length of current block with optimal trees */
354 ulg static_len; /* bit length of current block with static trees */
355 ulg compressed_len; /* total bit length of compressed file */
356 uInt matches; /* number of string matches in current block */
357 int last_eob_len; /* bit length of EOB code for last block */
360 ulg bits_sent; /* bit length of the compressed data */
364 /* Output buffer. bits are inserted starting at the bottom (least
368 /* Number of valid bits in bi_buf. All bits above the last valid bit
372 uInt blocks_in_packet;
373 /* Number of blocks produced since the last time Z_PACKET_FLUSH
379 /* Output a byte on the stream.
380 * IN assertion: there is enough room in pending_buf.
382 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
385 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
386 /* Minimum amount of lookahead, except at the end of the input file.
387 * See deflate.c for comments about the MIN_MATCH+1.
390 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
391 /* In order to simplify the code, particularly on 16 bit machines, match
392 * distances are limited to MAX_DIST instead of WSIZE.
396 local void ct_init OF((deflate_state *s));
397 local int ct_tally OF((deflate_state *s, int dist, int lc));
398 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
400 local void ct_align OF((deflate_state *s));
401 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
403 local void ct_stored_type_only OF((deflate_state *s));
407 /* deflate.c -- compress data using the deflation algorithm
408 * Copyright (C) 1995 Jean-loup Gailly.
409 * For conditions of distribution and use, see copyright notice in zlib.h
415 * The "deflation" process depends on being able to identify portions
416 * of the input text which are identical to earlier input (within a
417 * sliding window trailing behind the input currently being processed).
419 * The most straightforward technique turns out to be the fastest for
420 * most input files: try all possible matches and select the longest.
421 * The key feature of this algorithm is that insertions into the string
422 * dictionary are very simple and thus fast, and deletions are avoided
423 * completely. Insertions are performed at each input character, whereas
424 * string matches are performed only when the previous match ends. So it
425 * is preferable to spend more time in matches to allow very fast string
426 * insertions and avoid deletions. The matching algorithm for small
427 * strings is inspired from that of Rabin & Karp. A brute force approach
428 * is used to find longer strings when a small match has been found.
429 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
430 * (by Leonid Broukhis).
431 * A previous version of this file used a more sophisticated algorithm
432 * (by Fiala and Greene) which is guaranteed to run in linear amortized
433 * time, but has a larger average cost, uses more memory and is patented.
434 * However the F&G algorithm may be faster for some highly redundant
435 * files if the parameter max_chain_length (described below) is too large.
439 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
440 * I found it in 'freeze' written by Leonid Broukhis.
441 * Thanks to many people for bug reports and testing.
445 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
446 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
448 * A description of the Rabin and Karp algorithm is given in the book
449 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
451 * Fiala,E.R., and Greene,D.H.
452 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
456 /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */
458 char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
460 If you use the zlib library in a product, an acknowledgment is welcome
461 in the documentation of your product. If for some reason you cannot
462 include such an acknowledgment, I would appreciate that you keep this
463 copyright string in the executable of your product.
467 /* Tail of hash chains */
470 # define TOO_FAR 4096
472 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
474 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
475 /* Minimum amount of lookahead, except at the end of the input file.
476 * See deflate.c for comments about the MIN_MATCH+1.
479 /* Values for max_lazy_match, good_match and max_chain_length, depending on
480 * the desired pack level (0..9). The values given below have been tuned to
481 * exclude worst case performance for pathological files. Better values may be
482 * found for specific files.
485 typedef struct config_s {
486 ush good_length; /* reduce lazy search above this match length */
487 ush max_lazy; /* do not perform lazy search above this match length */
488 ush nice_length; /* quit search above this match length */
492 local config configuration_table[10] = {
493 /* good lazy nice chain */
494 /* 0 */ {0, 0, 0, 0}, /* store only */
495 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
496 /* 2 */ {4, 5, 16, 8},
497 /* 3 */ {4, 6, 32, 32},
499 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
500 /* 5 */ {8, 16, 32, 32},
501 /* 6 */ {8, 16, 128, 128},
502 /* 7 */ {8, 32, 128, 256},
503 /* 8 */ {32, 128, 258, 1024},
504 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
506 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
507 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
512 /* result of memcmp for equal strings */
514 /* ===========================================================================
515 * Prototypes for local functions.
518 local void fill_window OF((deflate_state *s));
519 local int deflate_fast OF((deflate_state *s, int flush));
520 local int deflate_slow OF((deflate_state *s, int flush));
521 local void lm_init OF((deflate_state *s));
522 local int longest_match OF((deflate_state *s, IPos cur_match));
523 local void putShortMSB OF((deflate_state *s, uInt b));
524 local void flush_pending OF((z_stream *strm));
525 local int zread_buf OF((z_stream *strm, charf *buf, unsigned size));
527 void match_init OF((void)); /* asm code initialization */
531 local void check_match OF((deflate_state *s, IPos start, IPos match,
536 /* ===========================================================================
537 * Update a hash value with the given input byte
538 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
539 * input characters, so that a running hash key can be computed from the
540 * previous key instead of complete recalculation each time.
542 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
545 /* ===========================================================================
546 * Insert string str in the dictionary and set match_head to the previous head
547 * of the hash chain (the most recent string with same hash key). Return
548 * the previous length of the hash chain.
549 * IN assertion: all calls to to INSERT_STRING are made with consecutive
550 * input characters and the first MIN_MATCH bytes of str are valid
551 * (except for the last MIN_MATCH-1 bytes of the input file).
553 #define INSERT_STRING(s, str, match_head) \
554 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
555 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
556 s->head[s->ins_h] = (str))
558 /* ===========================================================================
559 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
560 * prev[] will be initialized on the fly.
562 #define CLEAR_HASH(s) \
563 s->head[s->hash_size-1] = NIL; \
564 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
566 /* ========================================================================= */
567 int deflateInit (strm, level)
571 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
573 /* To do: ignore strm->next_in if we use it as window */
576 /* ========================================================================= */
577 int deflateInit2 (strm, level, method, windowBits, memLevel,
578 strategy, minCompression)
590 if (strm == Z_NULL) return Z_STREAM_ERROR;
593 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
594 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
596 if (level == Z_DEFAULT_COMPRESSION) level = 6;
598 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
600 windowBits = -windowBits;
602 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
603 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
604 return Z_STREAM_ERROR;
606 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
607 if (s == Z_NULL) return Z_MEM_ERROR;
608 strm->state = (struct internal_state FAR *)s;
611 s->noheader = noheader;
612 s->w_bits = windowBits;
613 s->w_size = 1 << s->w_bits;
614 s->w_mask = s->w_size - 1;
616 s->hash_bits = memLevel + 7;
617 s->hash_size = 1 << s->hash_bits;
618 s->hash_mask = s->hash_size - 1;
619 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
621 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
622 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
623 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
625 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
627 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
629 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
630 s->pending_buf == Z_NULL) {
631 strm->msg = z_errmsg[1-Z_MEM_ERROR];
635 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
636 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
637 /* We overlay pending_buf and d_buf+l_buf. This works since the average
638 * output size for (length,distance) codes is <= 32 bits (worst case
643 s->strategy = strategy;
644 s->method = (Byte)method;
645 s->minCompr = minCompression;
646 s->blocks_in_packet = 0;
648 return deflateReset(strm);
651 /* ========================================================================= */
652 int deflateReset (strm)
657 if (strm == Z_NULL || strm->state == Z_NULL ||
658 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
660 strm->total_in = strm->total_out = 0;
661 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
662 strm->data_type = Z_UNKNOWN;
664 s = (deflate_state *)strm->state;
666 s->pending_out = s->pending_buf;
668 if (s->noheader < 0) {
669 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
671 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
680 /* =========================================================================
681 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
682 * IN assertion: the stream state is correct and there is enough room in
685 local void putShortMSB (s, b)
689 put_byte(s, (Byte)(b >> 8));
690 put_byte(s, (Byte)(b & 0xff));
693 /* =========================================================================
694 * Flush as much pending output as possible.
696 local void flush_pending(strm)
699 deflate_state *state = (deflate_state *) strm->state;
700 unsigned len = state->pending;
702 if (len > strm->avail_out) len = strm->avail_out;
703 if (len == 0) return;
705 if (strm->next_out != NULL) {
706 zmemcpy(strm->next_out, state->pending_out, len);
707 strm->next_out += len;
709 state->pending_out += len;
710 strm->total_out += len;
711 strm->avail_out -= len;
712 state->pending -= len;
713 if (state->pending == 0) {
714 state->pending_out = state->pending_buf;
718 /* ========================================================================= */
719 int deflate (strm, flush)
723 deflate_state *state = (deflate_state *) strm->state;
725 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
727 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
728 ERR_RETURN(strm, Z_STREAM_ERROR);
730 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
732 state->strm = strm; /* just in case */
734 /* Write the zlib header */
735 if (state->status == INIT_STATE) {
737 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
738 uInt level_flags = (state->level-1) >> 1;
740 if (level_flags > 3) level_flags = 3;
741 header |= (level_flags << 6);
742 header += 31 - (header % 31);
744 state->status = BUSY_STATE;
745 putShortMSB(state, header);
748 /* Flush as much pending output as possible */
749 if (state->pending != 0) {
751 if (strm->avail_out == 0) return Z_OK;
754 /* If we came back in here to get the last output from
755 * a previous flush, we're done for now.
757 if (state->status == FLUSH_STATE) {
758 state->status = BUSY_STATE;
759 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
763 /* User must not provide more input after the first FINISH: */
764 if (state->status == FINISH_STATE && strm->avail_in != 0) {
765 ERR_RETURN(strm, Z_BUF_ERROR);
768 /* Start a new block or continue the current one.
770 if (strm->avail_in != 0 || state->lookahead != 0 ||
771 (flush == Z_FINISH && state->status != FINISH_STATE)) {
774 if (flush == Z_FINISH) {
775 state->status = FINISH_STATE;
777 if (state->level <= 3) {
778 quit = deflate_fast(state, flush);
780 quit = deflate_slow(state, flush);
782 if (quit || strm->avail_out == 0)
784 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
785 * of deflate should use the same flush parameter to make sure
786 * that the flush is complete. So we don't have to output an
787 * empty block here, this will be done at next call. This also
788 * ensures that for a very small output buffer, we emit at most
793 /* If a flush was requested, we have a little more to output now. */
794 if (flush != Z_NO_FLUSH && flush != Z_FINISH
795 && state->status != FINISH_STATE) {
797 case Z_PARTIAL_FLUSH:
801 /* Output just the 3-bit `stored' block type value,
802 but not a zero length. */
803 ct_stored_type_only(state);
806 ct_stored_block(state, (char*)0, 0L, 0);
807 /* For a full flush, this empty block will be recognized
808 * as a special marker by inflate_sync().
810 if (flush == Z_FULL_FLUSH) {
811 CLEAR_HASH(state); /* forget history */
815 if (strm->avail_out == 0) {
816 /* We'll have to come back to get the rest of the output;
817 * this ensures we don't output a second zero-length stored
818 * block (or whatever).
820 state->status = FLUSH_STATE;
825 Assert(strm->avail_out > 0, "bug2");
827 if (flush != Z_FINISH) return Z_OK;
828 if (state->noheader) return Z_STREAM_END;
830 /* Write the zlib trailer (adler32) */
831 putShortMSB(state, (uInt)(state->adler >> 16));
832 putShortMSB(state, (uInt)(state->adler & 0xffff));
834 /* If avail_out is zero, the application will call deflate again
837 state->noheader = -1; /* write the trailer only once! */
838 return state->pending != 0 ? Z_OK : Z_STREAM_END;
841 /* ========================================================================= */
842 int deflateEnd (strm)
845 deflate_state *state = (deflate_state *) strm->state;
847 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
849 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
850 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
851 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
852 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
854 ZFREE(strm, state, sizeof(deflate_state));
855 strm->state = Z_NULL;
860 /* ===========================================================================
861 * Read a new buffer from the current input stream, update the adler32
862 * and total number of bytes read.
864 local int zread_buf(strm, buf, size)
869 unsigned len = strm->avail_in;
870 deflate_state *state = (deflate_state *) strm->state;
872 if (len > size) len = size;
873 if (len == 0) return 0;
875 strm->avail_in -= len;
877 if (!state->noheader) {
878 state->adler = adler32(state->adler, strm->next_in, len);
880 zmemcpy(buf, strm->next_in, len);
881 strm->next_in += len;
882 strm->total_in += len;
887 /* ===========================================================================
888 * Initialize the "longest match" routines for a new zlib stream
890 local void lm_init (s)
893 s->window_size = (ulg)2L*s->w_size;
897 /* Set the default configuration parameters:
899 s->max_lazy_match = configuration_table[s->level].max_lazy;
900 s->good_match = configuration_table[s->level].good_length;
901 s->nice_match = configuration_table[s->level].nice_length;
902 s->max_chain_length = configuration_table[s->level].max_chain;
907 s->match_length = MIN_MATCH-1;
908 s->match_available = 0;
911 match_init(); /* initialize the asm code */
915 /* ===========================================================================
916 * Set match_start to the longest match starting at the given string and
917 * return its length. Matches shorter or equal to prev_length are discarded,
918 * in which case the result is equal to prev_length and match_start is
920 * IN assertions: cur_match is the head of the hash chain for the current
921 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
924 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
925 * match.S. The code will be functionally equivalent.
927 local int longest_match(s, cur_match)
929 IPos cur_match; /* current match */
931 unsigned chain_length = s->max_chain_length;/* max hash chain length */
932 register Bytef *scan = s->window + s->strstart; /* current string */
933 register Bytef *match; /* matched string */
934 register int len; /* length of current match */
935 int best_len = s->prev_length; /* best match length so far */
936 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
937 s->strstart - (IPos)MAX_DIST(s) : NIL;
938 /* Stop when cur_match becomes <= limit. To simplify the code,
939 * we prevent matches with the string of window index 0.
941 Posf *prev = s->prev;
942 uInt wmask = s->w_mask;
945 /* Compare two bytes at a time. Note: this is not always beneficial.
946 * Try with and without -DUNALIGNED_OK to check.
948 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
949 register ush scan_start = *(ushf*)scan;
950 register ush scan_end = *(ushf*)(scan+best_len-1);
952 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
953 register Byte scan_end1 = scan[best_len-1];
954 register Byte scan_end = scan[best_len];
957 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
958 * It is easy to get rid of this optimization if necessary.
960 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
962 /* Do not waste too much time if we already have a good match: */
963 if (s->prev_length >= s->good_match) {
966 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
969 Assert(cur_match < s->strstart, "no future");
970 match = s->window + cur_match;
972 /* Skip to next match if the match length cannot increase
973 * or if the match length is less than 2:
975 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
976 /* This code assumes sizeof(unsigned short) == 2. Do not use
977 * UNALIGNED_OK if your compiler uses a different size.
979 if (*(ushf*)(match+best_len-1) != scan_end ||
980 *(ushf*)match != scan_start) continue;
982 /* It is not necessary to compare scan[2] and match[2] since they are
983 * always equal when the other bytes match, given that the hash keys
984 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
985 * strstart+3, +5, ... up to strstart+257. We check for insufficient
986 * lookahead only every 4th comparison; the 128th check will be made
987 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
988 * necessary to put more guard bytes at the end of the window, or
989 * to check more often for insufficient lookahead.
991 Assert(scan[2] == match[2], "scan[2]?");
994 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
995 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
996 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
997 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
999 /* The funny "do {}" generates better code on most compilers */
1001 /* Here, scan <= window+strstart+257 */
1002 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1003 if (*scan == *match) scan++;
1005 len = (MAX_MATCH - 1) - (int)(strend-scan);
1006 scan = strend - (MAX_MATCH-1);
1008 #else /* UNALIGNED_OK */
1010 if (match[best_len] != scan_end ||
1011 match[best_len-1] != scan_end1 ||
1013 *++match != scan[1]) continue;
1015 /* The check at best_len-1 can be removed because it will be made
1016 * again later. (This heuristic is not always a win.)
1017 * It is not necessary to compare scan[2] and match[2] since they
1018 * are always equal when the other bytes match, given that
1019 * the hash keys are equal and that HASH_BITS >= 8.
1022 Assert(*scan == *match, "match[2]?");
1024 /* We check for insufficient lookahead only every 8th comparison;
1025 * the 256th check will be made at strstart+258.
1028 } while (*++scan == *++match && *++scan == *++match &&
1029 *++scan == *++match && *++scan == *++match &&
1030 *++scan == *++match && *++scan == *++match &&
1031 *++scan == *++match && *++scan == *++match &&
1034 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1036 len = MAX_MATCH - (int)(strend - scan);
1037 scan = strend - MAX_MATCH;
1039 #endif /* UNALIGNED_OK */
1041 if (len > best_len) {
1042 s->match_start = cur_match;
1044 if (len >= s->nice_match) break;
1046 scan_end = *(ushf*)(scan+best_len-1);
1048 scan_end1 = scan[best_len-1];
1049 scan_end = scan[best_len];
1052 } while ((cur_match = prev[cur_match & wmask]) > limit
1053 && --chain_length != 0);
1060 /* ===========================================================================
1061 * Check that the match at match_start is indeed a match.
1063 local void check_match(s, start, match, length)
1068 /* check that the match is indeed a match */
1069 if (memcmp((charf *)s->window + match,
1070 (charf *)s->window + start, length) != EQUAL) {
1072 " start %u, match %u, length %d\n",
1073 start, match, length);
1074 do { fprintf(stderr, "%c%c", s->window[match++],
1075 s->window[start++]); } while (--length != 0);
1076 z_error("invalid match");
1079 fprintf(stderr,"\\[%d,%d]", start-match, length);
1080 do { putc(s->window[start++], stderr); } while (--length != 0);
1084 # define check_match(s, start, match, length)
1087 /* ===========================================================================
1088 * Fill the window when the lookahead becomes insufficient.
1089 * Updates strstart and lookahead.
1091 * IN assertion: lookahead < MIN_LOOKAHEAD
1092 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1093 * At least one byte has been read, or avail_in == 0; reads are
1094 * performed for at least two bytes (required for the zip translate_eol
1095 * option -- not supported here).
1097 local void fill_window(s)
1100 register unsigned n, m;
1102 unsigned more; /* Amount of free space at the end of the window. */
1103 uInt wsize = s->w_size;
1106 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1108 /* Deal with !@#$% 64K limit: */
1109 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1111 } else if (more == (unsigned)(-1)) {
1112 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1113 * and lookahead == 1 (input done one byte at time)
1117 /* If the window is almost full and there is insufficient lookahead,
1118 * move the upper half to the lower one to make room in the upper half.
1120 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1122 /* By the IN assertion, the window is not empty so we can't confuse
1123 * more == 0 with more == 64K on a 16 bit machine.
1125 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1127 s->match_start -= wsize;
1128 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1130 s->block_start -= (long) wsize;
1132 /* Slide the hash table (could be avoided with 32 bit values
1133 at the expense of memory usage):
1139 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1146 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1147 /* If n is not on any hash chain, prev[n] is garbage but
1148 * its value will never be used.
1154 if (s->strm->avail_in == 0) return;
1156 /* If there was no sliding:
1157 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1158 * more == window_size - lookahead - strstart
1159 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1160 * => more >= window_size - 2*WSIZE + 2
1161 * In the BIG_MEM or MMAP case (not yet supported),
1162 * window_size == input_size + MIN_LOOKAHEAD &&
1163 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1164 * Otherwise, window_size == 2*WSIZE so more >= 2.
1165 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1167 Assert(more >= 2, "more < 2");
1169 n = zread_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1173 /* Initialize the hash value now that we have some input: */
1174 if (s->lookahead >= MIN_MATCH) {
1175 s->ins_h = s->window[s->strstart];
1176 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1178 Call UPDATE_HASH() MIN_MATCH-3 more times
1181 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1182 * but this is not important since only literal bytes will be emitted.
1185 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1188 /* ===========================================================================
1189 * Flush the current block, with given end-of-file flag.
1190 * IN assertion: strstart is set to the end of the current match.
1192 #define FLUSH_BLOCK_ONLY(s, flush) { \
1193 ct_flush_block(s, (s->block_start >= 0L ? \
1194 (charf *)&s->window[(unsigned)s->block_start] : \
1195 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1196 s->block_start = s->strstart; \
1197 flush_pending(s->strm); \
1198 Tracev((stderr,"[FLUSH]")); \
1201 /* Same but force premature exit if necessary. */
1202 #define FLUSH_BLOCK(s, flush) { \
1203 FLUSH_BLOCK_ONLY(s, flush); \
1204 if (s->strm->avail_out == 0) return 1; \
1207 /* ===========================================================================
1208 * Compress as much as possible from the input stream, return true if
1209 * processing was terminated prematurely (no more input or output space).
1210 * This function does not perform lazy evaluationof matches and inserts
1211 * new strings in the dictionary only for unmatched strings or for short
1212 * matches. It is used only for the fast compression options.
1214 local int deflate_fast(s, flush)
1218 IPos hash_head = NIL; /* head of the hash chain */
1219 int bflush; /* set if current block must be flushed */
1221 s->prev_length = MIN_MATCH-1;
1224 /* Make sure that we always have enough lookahead, except
1225 * at the end of the input file. We need MAX_MATCH bytes
1226 * for the next match, plus MIN_MATCH bytes to insert the
1227 * string following the next match.
1229 if (s->lookahead < MIN_LOOKAHEAD) {
1231 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1233 if (s->lookahead == 0) break; /* flush the current block */
1236 /* Insert the string window[strstart .. strstart+2] in the
1237 * dictionary, and set hash_head to the head of the hash chain:
1239 if (s->lookahead >= MIN_MATCH) {
1240 INSERT_STRING(s, s->strstart, hash_head);
1243 /* Find the longest match, discarding those <= prev_length.
1244 * At this point we have always match_length < MIN_MATCH
1246 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1247 /* To simplify the code, we prevent matches with the string
1248 * of window index 0 (in particular we have to avoid a match
1249 * of the string with itself at the start of the input file).
1251 if (s->strategy != Z_HUFFMAN_ONLY) {
1252 s->match_length = longest_match (s, hash_head);
1254 /* longest_match() sets match_start */
1256 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1258 if (s->match_length >= MIN_MATCH) {
1259 check_match(s, s->strstart, s->match_start, s->match_length);
1261 bflush = ct_tally(s, s->strstart - s->match_start,
1262 s->match_length - MIN_MATCH);
1264 s->lookahead -= s->match_length;
1266 /* Insert new strings in the hash table only if the match length
1267 * is not too large. This saves time but degrades compression.
1269 if (s->match_length <= s->max_insert_length &&
1270 s->lookahead >= MIN_MATCH) {
1271 s->match_length--; /* string at strstart already in hash table */
1274 INSERT_STRING(s, s->strstart, hash_head);
1275 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1276 * always MIN_MATCH bytes ahead.
1278 } while (--s->match_length != 0);
1281 s->strstart += s->match_length;
1282 s->match_length = 0;
1283 s->ins_h = s->window[s->strstart];
1284 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1286 Call UPDATE_HASH() MIN_MATCH-3 more times
1288 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1289 * matter since it will be recomputed at next deflate call.
1293 /* No match, output a literal byte */
1294 Tracevv((stderr,"%c", s->window[s->strstart]));
1295 bflush = ct_tally (s, 0, s->window[s->strstart]);
1299 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1301 FLUSH_BLOCK(s, flush);
1302 return 0; /* normal exit */
1305 /* ===========================================================================
1306 * Same as above, but achieves better compression. We use a lazy
1307 * evaluation for matches: a match is finally adopted only if there is
1308 * no better match at the next window position.
1310 local int deflate_slow(s, flush)
1314 IPos hash_head = NIL; /* head of hash chain */
1315 int bflush; /* set if current block must be flushed */
1317 /* Process the input block. */
1319 /* Make sure that we always have enough lookahead, except
1320 * at the end of the input file. We need MAX_MATCH bytes
1321 * for the next match, plus MIN_MATCH bytes to insert the
1322 * string following the next match.
1324 if (s->lookahead < MIN_LOOKAHEAD) {
1326 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1328 if (s->lookahead == 0) break; /* flush the current block */
1331 /* Insert the string window[strstart .. strstart+2] in the
1332 * dictionary, and set hash_head to the head of the hash chain:
1334 if (s->lookahead >= MIN_MATCH) {
1335 INSERT_STRING(s, s->strstart, hash_head);
1338 if (flush == Z_INSERT_ONLY) {
1344 /* Find the longest match, discarding those <= prev_length.
1346 s->prev_length = s->match_length, s->prev_match = s->match_start;
1347 s->match_length = MIN_MATCH-1;
1349 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1350 s->strstart - hash_head <= MAX_DIST(s)) {
1351 /* To simplify the code, we prevent matches with the string
1352 * of window index 0 (in particular we have to avoid a match
1353 * of the string with itself at the start of the input file).
1355 if (s->strategy != Z_HUFFMAN_ONLY) {
1356 s->match_length = longest_match (s, hash_head);
1358 /* longest_match() sets match_start */
1359 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1361 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1362 (s->match_length == MIN_MATCH &&
1363 s->strstart - s->match_start > TOO_FAR))) {
1365 /* If prev_match is also MIN_MATCH, match_start is garbage
1366 * but we will ignore the current match anyway.
1368 s->match_length = MIN_MATCH-1;
1371 /* If there was a match at the previous step and the current
1372 * match is not better, output the previous match:
1374 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1375 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1376 /* Do not insert strings in hash table beyond this. */
1378 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1380 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1381 s->prev_length - MIN_MATCH);
1383 /* Insert in hash table all strings up to the end of the match.
1384 * strstart-1 and strstart are already inserted. If there is not
1385 * enough lookahead, the last two strings are not inserted in
1388 s->lookahead -= s->prev_length-1;
1389 s->prev_length -= 2;
1391 if (++s->strstart <= max_insert) {
1392 INSERT_STRING(s, s->strstart, hash_head);
1394 } while (--s->prev_length != 0);
1395 s->match_available = 0;
1396 s->match_length = MIN_MATCH-1;
1399 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1401 } else if (s->match_available) {
1402 /* If there was no match at the previous position, output a
1403 * single literal. If there was a match but the current match
1404 * is longer, truncate the previous match to a single literal.
1406 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1407 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1408 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1412 if (s->strm->avail_out == 0) return 1;
1414 /* There is no previous match to compare with, wait for
1415 * the next step to decide.
1417 s->match_available = 1;
1422 if (flush == Z_INSERT_ONLY) {
1423 s->block_start = s->strstart;
1426 Assert (flush != Z_NO_FLUSH, "no flush?");
1427 if (s->match_available) {
1428 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1429 ct_tally (s, 0, s->window[s->strstart-1]);
1430 s->match_available = 0;
1432 FLUSH_BLOCK(s, flush);
1438 /* trees.c -- output deflated data using Huffman coding
1439 * Copyright (C) 1995 Jean-loup Gailly
1440 * For conditions of distribution and use, see copyright notice in zlib.h
1446 * The "deflation" process uses several Huffman trees. The more
1447 * common source values are represented by shorter bit sequences.
1449 * Each code tree is stored in a compressed form which is itself
1450 * a Huffman encoding of the lengths of all the code strings (in
1451 * ascending order by source values). The actual code strings are
1452 * reconstructed from the lengths in the inflate process, as described
1453 * in the deflate specification.
1457 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1458 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1461 * Data Compression: Methods and Theory, pp. 49-50.
1462 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1466 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1469 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
1475 /* ===========================================================================
1479 #define MAX_BL_BITS 7
1480 /* Bit length codes must not exceed MAX_BL_BITS bits */
1482 #define END_BLOCK 256
1483 /* end of block literal code */
1486 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1488 #define REPZ_3_10 17
1489 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1491 #define REPZ_11_138 18
1492 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1494 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1495 = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};
1497 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1498 = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
1500 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1501 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1503 local uch bl_order[BL_CODES]
1504 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1505 /* The lengths of the bit length codes are sent in order of decreasing
1506 * probability, to avoid transmitting the lengths for unused bit length codes.
1509 #define Buf_size (8 * 2*sizeof(char))
1510 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1511 * more than 16 bits on some systems.)
1514 /* ===========================================================================
1515 * Local data. These are initialized only once.
1516 * To do: initialize at compile time to be completely reentrant. ???
1519 local ct_data static_ltree[L_CODES+2];
1520 /* The static literal tree. Since the bit lengths are imposed, there is no
1521 * need for the L_CODES extra codes used during heap construction. However
1522 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1526 local ct_data static_dtree[D_CODES];
1527 /* The static distance tree. (Actually a trivial tree since all codes use
1531 local uch dist_code[512];
1532 /* distance codes. The first 256 values correspond to the distances
1533 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1534 * the 15 bit distances.
1537 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1538 /* length code for each normalized match length (0 == MIN_MATCH) */
1540 local int base_length[LENGTH_CODES];
1541 /* First normalized length for each code (0 = MIN_MATCH) */
1543 local int base_dist[D_CODES];
1544 /* First normalized distance for each code (0 = distance of 1) */
1546 struct static_tree_desc_s {
1547 ct_data *static_tree; /* static tree or NULL */
1548 intf *extra_bits; /* extra bits for each code or NULL */
1549 int extra_base; /* base index for extra_bits */
1550 int elems; /* max number of elements in the tree */
1551 int max_length; /* max bit length for the codes */
1554 local static_tree_desc static_l_desc =
1555 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1557 local static_tree_desc static_d_desc =
1558 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1560 local static_tree_desc static_bl_desc =
1561 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1563 /* ===========================================================================
1564 * Local (static) routines in this file.
1567 local void ct_static_init OF((void));
1568 local void init_block OF((deflate_state *s));
1569 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1570 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1571 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1572 local void build_tree OF((deflate_state *s, tree_desc *desc));
1573 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1574 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1575 local int build_bl_tree OF((deflate_state *s));
1576 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1578 local void compress_block OF((deflate_state *s, ct_data *ltree,
1580 local void set_data_type OF((deflate_state *s));
1581 local unsigned bi_reverse OF((unsigned value, int length));
1582 local void bi_windup OF((deflate_state *s));
1583 local void bi_flush OF((deflate_state *s));
1584 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1588 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1589 /* Send a code of the given tree. c and tree must not have side effects */
1591 #else /* DEBUG_ZLIB */
1592 # define send_code(s, c, tree) \
1593 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1594 send_bits(s, tree[c].Code, tree[c].Len); }
1597 #define d_code(dist) \
1598 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1599 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1600 * must not have side effects. dist_code[256] and dist_code[257] are never
1604 /* ===========================================================================
1605 * Output a short LSB first on the stream.
1606 * IN assertion: there is enough room in pendingBuf.
1608 #define put_short(s, w) { \
1609 put_byte(s, (uch)((w) & 0xff)); \
1610 put_byte(s, (uch)((ush)(w) >> 8)); \
1613 /* ===========================================================================
1614 * Send a value on a given number of bits.
1615 * IN assertion: length <= 16 and value fits in length bits.
1618 local void send_bits OF((deflate_state *s, int value, int length));
1620 local void send_bits(s, value, length)
1622 int value; /* value to send */
1623 int length; /* number of bits */
1625 Tracev((stderr," l %2d v %4x ", length, value));
1626 Assert(length > 0 && length <= 15, "invalid length");
1627 s->bits_sent += (ulg)length;
1629 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1630 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1631 * unused bits in value.
1633 if (s->bi_valid > (int)Buf_size - length) {
1634 s->bi_buf |= (value << s->bi_valid);
1635 put_short(s, s->bi_buf);
1636 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1637 s->bi_valid += length - Buf_size;
1639 s->bi_buf |= value << s->bi_valid;
1640 s->bi_valid += length;
1643 #else /* !DEBUG_ZLIB */
1645 #define send_bits(s, value, length) \
1646 { int len = length;\
1647 if (s->bi_valid > (int)Buf_size - len) {\
1649 s->bi_buf |= (val << s->bi_valid);\
1650 put_short(s, s->bi_buf);\
1651 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1652 s->bi_valid += len - Buf_size;\
1654 s->bi_buf |= (value) << s->bi_valid;\
1655 s->bi_valid += len;\
1658 #endif /* DEBUG_ZLIB */
1661 /* the arguments must not have side effects */
1663 /* ===========================================================================
1664 * Initialize the various 'constant' tables.
1665 * To do: do this at compile time.
1667 local void ct_static_init()
1669 int n; /* iterates over tree elements */
1670 int bits; /* bit counter */
1671 int length; /* length value */
1672 int code; /* code value */
1673 int dist; /* distance index */
1674 ush bl_count[MAX_BITS+1];
1675 /* number of codes at each bit length for an optimal tree */
1677 /* Initialize the mapping length (0..255) -> length code (0..28) */
1679 for (code = 0; code < LENGTH_CODES-1; code++) {
1680 base_length[code] = length;
1681 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1682 length_code[length++] = (uch)code;
1685 Assert (length == 256, "ct_static_init: length != 256");
1686 /* Note that the length 255 (match length 258) can be represented
1687 * in two different ways: code 284 + 5 bits or code 285, so we
1688 * overwrite length_code[255] to use the best encoding:
1690 length_code[length-1] = (uch)code;
1692 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1694 for (code = 0 ; code < 16; code++) {
1695 base_dist[code] = dist;
1696 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1697 dist_code[dist++] = (uch)code;
1700 Assert (dist == 256, "ct_static_init: dist != 256");
1701 dist >>= 7; /* from now on, all distances are divided by 128 */
1702 for ( ; code < D_CODES; code++) {
1703 base_dist[code] = dist << 7;
1704 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1705 dist_code[256 + dist++] = (uch)code;
1708 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1710 /* Construct the codes of the static literal tree */
1711 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1713 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1714 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1715 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1716 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1717 /* Codes 286 and 287 do not exist, but we must include them in the
1718 * tree construction to get a canonical Huffman tree (longest code
1721 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1723 /* The static distance tree is trivial: */
1724 for (n = 0; n < D_CODES; n++) {
1725 static_dtree[n].Len = 5;
1726 static_dtree[n].Code = bi_reverse(n, 5);
1730 /* ===========================================================================
1731 * Initialize the tree data structures for a new zlib stream.
1733 local void ct_init(s)
1736 if (static_dtree[0].Len == 0) {
1737 ct_static_init(); /* To do: at compile time */
1740 s->compressed_len = 0L;
1742 s->l_desc.dyn_tree = s->dyn_ltree;
1743 s->l_desc.stat_desc = &static_l_desc;
1745 s->d_desc.dyn_tree = s->dyn_dtree;
1746 s->d_desc.stat_desc = &static_d_desc;
1748 s->bl_desc.dyn_tree = s->bl_tree;
1749 s->bl_desc.stat_desc = &static_bl_desc;
1753 s->last_eob_len = 8; /* enough lookahead for inflate */
1757 s->blocks_in_packet = 0;
1759 /* Initialize the first block of the first file: */
1763 /* ===========================================================================
1764 * Initialize a new block.
1766 local void init_block(s)
1769 int n; /* iterates over tree elements */
1771 /* Initialize the trees. */
1772 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1773 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1774 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1776 s->dyn_ltree[END_BLOCK].Freq = 1;
1777 s->opt_len = s->static_len = 0L;
1778 s->last_lit = s->matches = 0;
1782 /* Index within the heap array of least frequent node in the Huffman tree */
1785 /* ===========================================================================
1786 * Remove the smallest element from the heap and recreate the heap with
1787 * one less element. Updates heap and heap_len.
1789 #define pqremove(s, tree, top) \
1791 top = s->heap[SMALLEST]; \
1792 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1793 pqdownheap(s, tree, SMALLEST); \
1796 /* ===========================================================================
1797 * Compares to subtrees, using the tree depth as tie breaker when
1798 * the subtrees have equal frequency. This minimizes the worst case length.
1800 #define smaller(tree, n, m, depth) \
1801 (tree[n].Freq < tree[m].Freq || \
1802 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1804 /* ===========================================================================
1805 * Restore the heap property by moving down the tree starting at node k,
1806 * exchanging a node with the smallest of its two sons if necessary, stopping
1807 * when the heap property is re-established (each father smaller than its
1810 local void pqdownheap(s, tree, k)
1812 ct_data *tree; /* the tree to restore */
1813 int k; /* node to move down */
1816 int j = k << 1; /* left son of k */
1817 while (j <= s->heap_len) {
1818 /* Set j to the smallest of the two sons: */
1819 if (j < s->heap_len &&
1820 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1823 /* Exit if v is smaller than both sons */
1824 if (smaller(tree, v, s->heap[j], s->depth)) break;
1826 /* Exchange v with the smallest son */
1827 s->heap[k] = s->heap[j]; k = j;
1829 /* And continue down the tree, setting j to the left son of k */
1835 /* ===========================================================================
1836 * Compute the optimal bit lengths for a tree and update the total bit length
1837 * for the current block.
1838 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1839 * above are the tree nodes sorted by increasing frequency.
1840 * OUT assertions: the field len is set to the optimal bit length, the
1841 * array bl_count contains the frequencies for each bit length.
1842 * The length opt_len is updated; static_len is also updated if stree is
1845 local void gen_bitlen(s, desc)
1847 tree_desc *desc; /* the tree descriptor */
1849 ct_data *tree = desc->dyn_tree;
1850 int max_code = desc->max_code;
1851 ct_data *stree = desc->stat_desc->static_tree;
1852 intf *extra = desc->stat_desc->extra_bits;
1853 int base = desc->stat_desc->extra_base;
1854 int max_length = desc->stat_desc->max_length;
1855 int h; /* heap index */
1856 int n, m; /* iterate over the tree elements */
1857 int bits; /* bit length */
1858 int xbits; /* extra bits */
1859 ush f; /* frequency */
1860 int overflow = 0; /* number of elements with bit length too large */
1862 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1864 /* In a first pass, compute the optimal bit lengths (which may
1865 * overflow in the case of the bit length tree).
1867 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1869 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1871 bits = tree[tree[n].Dad].Len + 1;
1872 if (bits > max_length) bits = max_length, overflow++;
1873 tree[n].Len = (ush)bits;
1874 /* We overwrite tree[n].Dad which is no longer needed */
1876 if (n > max_code) continue; /* not a leaf node */
1878 s->bl_count[bits]++;
1880 if (n >= base) xbits = extra[n-base];
1882 s->opt_len += (ulg)f * (bits + xbits);
1883 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1885 if (overflow == 0) return;
1887 Trace((stderr,"\nbit length overflow\n"));
1888 /* This happens for example on obj2 and pic of the Calgary corpus */
1890 /* Find the first bit length which could increase: */
1892 bits = max_length-1;
1893 while (s->bl_count[bits] == 0) bits--;
1894 s->bl_count[bits]--; /* move one leaf down the tree */
1895 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1896 s->bl_count[max_length]--;
1897 /* The brother of the overflow item also moves one step up,
1898 * but this does not affect bl_count[max_length]
1901 } while (overflow > 0);
1903 /* Now recompute all bit lengths, scanning in increasing frequency.
1904 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1905 * lengths instead of fixing only the wrong ones. This idea is taken
1906 * from 'ar' written by Haruhiko Okumura.)
1908 for (bits = max_length; bits != 0; bits--) {
1909 n = s->bl_count[bits];
1912 if (m > max_code) continue;
1913 if (tree[m].Len != (unsigned) bits) {
1914 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1915 s->opt_len += ((long)bits - (long)tree[m].Len)
1916 *(long)tree[m].Freq;
1917 tree[m].Len = (ush)bits;
1924 /* ===========================================================================
1925 * Generate the codes for a given tree and bit counts (which need not be
1927 * IN assertion: the array bl_count contains the bit length statistics for
1928 * the given tree and the field len is set for all tree elements.
1929 * OUT assertion: the field code is set for all tree elements of non
1932 local void gen_codes (tree, max_code, bl_count)
1933 ct_data *tree; /* the tree to decorate */
1934 int max_code; /* largest code with non zero frequency */
1935 ushf *bl_count; /* number of codes at each bit length */
1937 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1938 ush code = 0; /* running code value */
1939 int bits; /* bit index */
1940 int n; /* code index */
1942 /* The distribution counts are first used to generate the code values
1943 * without bit reversal.
1945 for (bits = 1; bits <= MAX_BITS; bits++) {
1946 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1948 /* Check that the bit counts in bl_count are consistent. The last code
1951 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1952 "inconsistent bit counts");
1953 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1955 for (n = 0; n <= max_code; n++) {
1956 int len = tree[n].Len;
1957 if (len == 0) continue;
1958 /* Now reverse the bits */
1959 tree[n].Code = bi_reverse(next_code[len]++, len);
1961 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1962 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1966 /* ===========================================================================
1967 * Construct one Huffman tree and assigns the code bit strings and lengths.
1968 * Update the total bit length for the current block.
1969 * IN assertion: the field freq is set for all tree elements.
1970 * OUT assertions: the fields len and code are set to the optimal bit length
1971 * and corresponding code. The length opt_len is updated; static_len is
1972 * also updated if stree is not null. The field max_code is set.
1974 local void build_tree(s, desc)
1976 tree_desc *desc; /* the tree descriptor */
1978 ct_data *tree = desc->dyn_tree;
1979 ct_data *stree = desc->stat_desc->static_tree;
1980 int elems = desc->stat_desc->elems;
1981 int n, m; /* iterate over heap elements */
1982 int max_code = -1; /* largest code with non zero frequency */
1983 int node; /* new node being created */
1985 /* Construct the initial heap, with least frequent element in
1986 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
1987 * heap[0] is not used.
1989 s->heap_len = 0, s->heap_max = HEAP_SIZE;
1991 for (n = 0; n < elems; n++) {
1992 if (tree[n].Freq != 0) {
1993 s->heap[++(s->heap_len)] = max_code = n;
2000 /* The pkzip format requires that at least one distance code exists,
2001 * and that at least one bit should be sent even if there is only one
2002 * possible code. So to avoid special checks later on we force at least
2003 * two codes of non zero frequency.
2005 while (s->heap_len < 2) {
2006 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2007 tree[node].Freq = 1;
2009 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2010 /* node is 0 or 1 so it does not have extra bits */
2012 desc->max_code = max_code;
2014 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2015 * establish sub-heaps of increasing lengths:
2017 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2019 /* Construct the Huffman tree by repeatedly combining the least two
2022 node = elems; /* next internal node of the tree */
2024 pqremove(s, tree, n); /* n = node of least frequency */
2025 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2027 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2028 s->heap[--(s->heap_max)] = m;
2030 /* Create a new node father of n and m */
2031 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2032 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2033 tree[n].Dad = tree[m].Dad = (ush)node;
2035 if (tree == s->bl_tree) {
2036 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2037 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2040 /* and insert the new node in the heap */
2041 s->heap[SMALLEST] = node++;
2042 pqdownheap(s, tree, SMALLEST);
2044 } while (s->heap_len >= 2);
2046 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2048 /* At this point, the fields freq and dad are set. We can now
2049 * generate the bit lengths.
2051 gen_bitlen(s, (tree_desc *)desc);
2053 /* The field len is now set, we can generate the bit codes */
2054 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2057 /* ===========================================================================
2058 * Scan a literal or distance tree to determine the frequencies of the codes
2059 * in the bit length tree.
2061 local void scan_tree (s, tree, max_code)
2063 ct_data *tree; /* the tree to be scanned */
2064 int max_code; /* and its largest code of non zero frequency */
2066 int n; /* iterates over all tree elements */
2067 int prevlen = -1; /* last emitted length */
2068 int curlen; /* length of current code */
2069 int nextlen = tree[0].Len; /* length of next code */
2070 int count = 0; /* repeat count of the current code */
2071 int max_count = 7; /* max repeat count */
2072 int min_count = 4; /* min repeat count */
2074 if (nextlen == 0) max_count = 138, min_count = 3;
2075 tree[max_code+1].Len = (ush)0xffff; /* guard */
2077 for (n = 0; n <= max_code; n++) {
2078 curlen = nextlen; nextlen = tree[n+1].Len;
2079 if (++count < max_count && curlen == nextlen) {
2081 } else if (count < min_count) {
2082 s->bl_tree[curlen].Freq += count;
2083 } else if (curlen != 0) {
2084 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2085 s->bl_tree[REP_3_6].Freq++;
2086 } else if (count <= 10) {
2087 s->bl_tree[REPZ_3_10].Freq++;
2089 s->bl_tree[REPZ_11_138].Freq++;
2091 count = 0; prevlen = curlen;
2093 max_count = 138, min_count = 3;
2094 } else if (curlen == nextlen) {
2095 max_count = 6, min_count = 3;
2097 max_count = 7, min_count = 4;
2102 /* ===========================================================================
2103 * Send a literal or distance tree in compressed form, using the codes in
2106 local void send_tree (s, tree, max_code)
2108 ct_data *tree; /* the tree to be scanned */
2109 int max_code; /* and its largest code of non zero frequency */
2111 int n; /* iterates over all tree elements */
2112 int prevlen = -1; /* last emitted length */
2113 int curlen; /* length of current code */
2114 int nextlen = tree[0].Len; /* length of next code */
2115 int count = 0; /* repeat count of the current code */
2116 int max_count = 7; /* max repeat count */
2117 int min_count = 4; /* min repeat count */
2119 /* tree[max_code+1].Len = -1; */ /* guard already set */
2120 if (nextlen == 0) max_count = 138, min_count = 3;
2122 for (n = 0; n <= max_code; n++) {
2123 curlen = nextlen; nextlen = tree[n+1].Len;
2124 if (++count < max_count && curlen == nextlen) {
2126 } else if (count < min_count) {
2127 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2129 } else if (curlen != 0) {
2130 if (curlen != prevlen) {
2131 send_code(s, curlen, s->bl_tree); count--;
2133 Assert(count >= 3 && count <= 6, " 3_6?");
2134 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2136 } else if (count <= 10) {
2137 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2140 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2142 count = 0; prevlen = curlen;
2144 max_count = 138, min_count = 3;
2145 } else if (curlen == nextlen) {
2146 max_count = 6, min_count = 3;
2148 max_count = 7, min_count = 4;
2153 /* ===========================================================================
2154 * Construct the Huffman tree for the bit lengths and return the index in
2155 * bl_order of the last bit length code to send.
2157 local int build_bl_tree(s)
2160 int max_blindex; /* index of last bit length code of non zero freq */
2162 /* Determine the bit length frequencies for literal and distance trees */
2163 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2164 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2166 /* Build the bit length tree: */
2167 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2168 /* opt_len now includes the length of the tree representations, except
2169 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2172 /* Determine the number of bit length codes to send. The pkzip format
2173 * requires that at least 4 bit length codes be sent. (appnote.txt says
2174 * 3 but the actual value used is 4.)
2176 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2177 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2179 /* Update opt_len to include the bit length tree and counts */
2180 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2181 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2182 s->opt_len, s->static_len));
2187 /* ===========================================================================
2188 * Send the header for a block using dynamic Huffman trees: the counts, the
2189 * lengths of the bit length codes, the literal tree and the distance tree.
2190 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2192 local void send_all_trees(s, lcodes, dcodes, blcodes)
2194 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2196 int rank; /* index in bl_order */
2198 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2199 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2201 Tracev((stderr, "\nbl counts: "));
2202 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2203 send_bits(s, dcodes-1, 5);
2204 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2205 for (rank = 0; rank < blcodes; rank++) {
2206 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2207 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2209 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2211 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2212 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2214 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2215 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2218 /* ===========================================================================
2219 * Send a stored block
2221 local void ct_stored_block(s, buf, stored_len, eof)
2223 charf *buf; /* input block */
2224 ulg stored_len; /* length of input block */
2225 int eof; /* true if this is the last block for a file */
2227 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2228 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2229 s->compressed_len += (stored_len + 4) << 3;
2231 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2234 /* Send just the `stored block' type code without any length bytes or data.
2236 local void ct_stored_type_only(s)
2239 send_bits(s, (STORED_BLOCK << 1), 3);
2241 s->compressed_len = (s->compressed_len + 3) & ~7L;
2245 /* ===========================================================================
2246 * Send one empty static block to give enough lookahead for inflate.
2247 * This takes 10 bits, of which 7 may remain in the bit buffer.
2248 * The current inflate code requires 9 bits of lookahead. If the EOB
2249 * code for the previous block was coded on 5 bits or less, inflate
2250 * may have only 5+3 bits of lookahead to decode this EOB.
2251 * (There are no problems if the previous block is stored or fixed.)
2253 local void ct_align(s)
2256 send_bits(s, STATIC_TREES<<1, 3);
2257 send_code(s, END_BLOCK, static_ltree);
2258 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2260 /* Of the 10 bits for the empty block, we have already sent
2261 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2262 * block was thus its length plus what we have just sent.
2264 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2265 send_bits(s, STATIC_TREES<<1, 3);
2266 send_code(s, END_BLOCK, static_ltree);
2267 s->compressed_len += 10L;
2270 s->last_eob_len = 7;
2273 /* ===========================================================================
2274 * Determine the best encoding for the current block: dynamic trees, static
2275 * trees or store, and output the encoded block to the zip file. This function
2276 * returns the total compressed length for the file so far.
2278 local ulg ct_flush_block(s, buf, stored_len, flush)
2280 charf *buf; /* input block, or NULL if too old */
2281 ulg stored_len; /* length of input block */
2282 int flush; /* Z_FINISH if this is the last block for a file */
2284 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2285 int max_blindex; /* index of last bit length code of non zero freq */
2286 int eof = flush == Z_FINISH;
2288 ++s->blocks_in_packet;
2290 /* Check if the file is ascii or binary */
2291 if (s->data_type == UNKNOWN) set_data_type(s);
2293 /* Construct the literal and distance trees */
2294 build_tree(s, (tree_desc *)(&(s->l_desc)));
2295 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2298 build_tree(s, (tree_desc *)(&(s->d_desc)));
2299 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2301 /* At this point, opt_len and static_len are the total bit lengths of
2302 * the compressed block data, excluding the tree representations.
2305 /* Build the bit length tree for the above two trees, and get the index
2306 * in bl_order of the last bit length code to send.
2308 max_blindex = build_bl_tree(s);
2310 /* Determine the best encoding. Compute first the block length in bytes */
2311 opt_lenb = (s->opt_len+3+7)>>3;
2312 static_lenb = (s->static_len+3+7)>>3;
2314 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2315 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2318 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2320 /* If compression failed and this is the first and last block,
2321 * and if the .zip file can be seeked (to rewrite the local header),
2322 * the whole file is transformed into a stored file:
2324 #ifdef STORED_FILE_OK
2325 # ifdef FORCE_STORED_FILE
2326 if (eof && compressed_len == 0L) /* force stored file */
2328 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2331 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2332 if (buf == (charf*)0) error ("block vanished");
2334 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2335 s->compressed_len = stored_len << 3;
2338 #endif /* STORED_FILE_OK */
2340 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
2341 * compression, and this block contains all the data since the last
2342 * time we used Z_PACKET_FLUSH, then just omit this block completely
2345 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
2346 && opt_lenb > stored_len - s->minCompr) {
2347 s->blocks_in_packet = 0;
2348 /* output nothing */
2352 if (buf != (char*)0) /* force stored block */
2354 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2355 /* 4: two words for the lengths */
2358 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2359 * Otherwise we can't have processed more than WSIZE input bytes since
2360 * the last block flush, because compression would have been
2361 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2362 * transform a block into a stored block.
2364 ct_stored_block(s, buf, stored_len, eof);
2368 if (static_lenb >= 0) /* force static trees */
2370 if (static_lenb == opt_lenb)
2373 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2374 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2375 s->compressed_len += 3 + s->static_len;
2377 send_bits(s, (DYN_TREES<<1)+eof, 3);
2378 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2380 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2381 s->compressed_len += 3 + s->opt_len;
2383 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2388 s->compressed_len += 7; /* align on byte boundary */
2390 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2391 s->compressed_len-7*eof));
2393 return s->compressed_len >> 3;
2396 /* ===========================================================================
2397 * Save the match info and tally the frequency counts. Return true if
2398 * the current block must be flushed.
2400 local int ct_tally (s, dist, lc)
2402 int dist; /* distance of matched string */
2403 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2405 s->d_buf[s->last_lit] = (ush)dist;
2406 s->l_buf[s->last_lit++] = (uch)lc;
2408 /* lc is the unmatched char */
2409 s->dyn_ltree[lc].Freq++;
2412 /* Here, lc is the match length - MIN_MATCH */
2413 dist--; /* dist = match distance - 1 */
2414 Assert((ush)dist < (ush)MAX_DIST(s) &&
2415 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2416 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2418 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2419 s->dyn_dtree[d_code(dist)].Freq++;
2422 /* Try to guess if it is profitable to stop the current block here */
2423 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2424 /* Compute an upper bound for the compressed length */
2425 ulg out_length = (ulg)s->last_lit*8L;
2426 ulg in_length = (ulg)s->strstart - s->block_start;
2428 for (dcode = 0; dcode < D_CODES; dcode++) {
2429 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2430 (5L+extra_dbits[dcode]);
2433 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2434 s->last_lit, in_length, out_length,
2435 100L - out_length*100L/in_length));
2436 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2438 return (s->last_lit == s->lit_bufsize-1);
2439 /* We avoid equality with lit_bufsize because of wraparound at 64K
2440 * on 16 bit machines and because stored blocks are restricted to
2445 /* ===========================================================================
2446 * Send the block data compressed using the given Huffman trees
2448 local void compress_block(s, ltree, dtree)
2450 ct_data *ltree; /* literal tree */
2451 ct_data *dtree; /* distance tree */
2453 unsigned dist; /* distance of matched string */
2454 int lc; /* match length or unmatched char (if dist == 0) */
2455 unsigned lx = 0; /* running index in l_buf */
2456 unsigned code; /* the code to send */
2457 int extra; /* number of extra bits to send */
2459 if (s->last_lit != 0) do {
2460 dist = s->d_buf[lx];
2461 lc = s->l_buf[lx++];
2463 send_code(s, lc, ltree); /* send a literal byte */
2464 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2466 /* Here, lc is the match length - MIN_MATCH */
2467 code = length_code[lc];
2468 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2469 extra = extra_lbits[code];
2471 lc -= base_length[code];
2472 send_bits(s, lc, extra); /* send the extra length bits */
2474 dist--; /* dist is now the match distance - 1 */
2475 code = d_code(dist);
2476 Assert (code < D_CODES, "bad d_code");
2478 send_code(s, code, dtree); /* send the distance code */
2479 extra = extra_dbits[code];
2481 dist -= base_dist[code];
2482 send_bits(s, dist, extra); /* send the extra distance bits */
2484 } /* literal or match pair ? */
2486 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2487 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2489 } while (lx < s->last_lit);
2491 send_code(s, END_BLOCK, ltree);
2492 s->last_eob_len = ltree[END_BLOCK].Len;
2495 /* ===========================================================================
2496 * Set the data type to ASCII or BINARY, using a crude approximation:
2497 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2498 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2499 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2501 local void set_data_type(s)
2505 unsigned ascii_freq = 0;
2506 unsigned bin_freq = 0;
2507 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2508 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2509 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2510 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2513 /* ===========================================================================
2514 * Reverse the first len bits of a code, using straightforward code (a faster
2515 * method would use a table)
2516 * IN assertion: 1 <= len <= 15
2518 local unsigned bi_reverse(code, len)
2519 unsigned code; /* the value to invert */
2520 int len; /* its bit length */
2522 register unsigned res = 0;
2525 code >>= 1, res <<= 1;
2526 } while (--len > 0);
2530 /* ===========================================================================
2531 * Flush the bit buffer, keeping at most 7 bits in it.
2533 local void bi_flush(s)
2536 if (s->bi_valid == 16) {
2537 put_short(s, s->bi_buf);
2540 } else if (s->bi_valid >= 8) {
2541 put_byte(s, (Byte)s->bi_buf);
2547 /* ===========================================================================
2548 * Flush the bit buffer and align the output on a byte boundary
2550 local void bi_windup(s)
2553 if (s->bi_valid > 8) {
2554 put_short(s, s->bi_buf);
2555 } else if (s->bi_valid > 0) {
2556 put_byte(s, (Byte)s->bi_buf);
2561 s->bits_sent = (s->bits_sent+7) & ~7;
2565 /* ===========================================================================
2566 * Copy a stored block, storing first the length and its
2567 * one's complement if requested.
2569 local void copy_block(s, buf, len, header)
2571 charf *buf; /* the input data */
2572 unsigned len; /* its length */
2573 int header; /* true if block header must be written */
2575 bi_windup(s); /* align on byte boundary */
2576 s->last_eob_len = 8; /* enough lookahead for inflate */
2579 put_short(s, (ush)len);
2580 put_short(s, (ush)~len);
2582 s->bits_sent += 2*16;
2586 s->bits_sent += (ulg)len<<3;
2589 put_byte(s, *buf++);
2595 /* infblock.h -- header to use infblock.c
2596 * Copyright (C) 1995 Mark Adler
2597 * For conditions of distribution and use, see copyright notice in zlib.h
2600 /* WARNING: this file should *not* be used by applications. It is
2601 part of the implementation of the compression library and is
2602 subject to change. Applications should only use zlib.h.
2605 struct inflate_blocks_state;
2606 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2608 local inflate_blocks_statef * inflate_blocks_new OF((
2610 check_func c, /* check function */
2611 uInt w)); /* window size */
2613 local int inflate_blocks OF((
2614 inflate_blocks_statef *,
2616 int)); /* initial return code */
2618 local void inflate_blocks_reset OF((
2619 inflate_blocks_statef *,
2621 uLongf *)); /* check value on output */
2623 local int inflate_blocks_free OF((
2624 inflate_blocks_statef *,
2626 uLongf *)); /* check value on output */
2628 local int inflate_addhistory OF((
2629 inflate_blocks_statef *,
2632 local int inflate_packet_flush OF((
2633 inflate_blocks_statef *));
2636 /* inftrees.h -- header to use inftrees.c
2637 * Copyright (C) 1995 Mark Adler
2638 * For conditions of distribution and use, see copyright notice in zlib.h
2641 /* WARNING: this file should *not* be used by applications. It is
2642 part of the implementation of the compression library and is
2643 subject to change. Applications should only use zlib.h.
2646 /* Huffman code lookup table entry--this entry is four bytes for machines
2647 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2649 typedef struct inflate_huft_s FAR inflate_huft;
2651 struct inflate_huft_s {
2654 Byte Exop; /* number of extra bits or operation */
2655 Byte Bits; /* number of bits in this code or subcode */
2657 uInt Nalloc; /* number of these allocated here */
2658 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2659 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2661 uInt Base; /* literal, length base, or distance base */
2662 inflate_huft *Next; /* pointer to next level of table */
2667 local uInt inflate_hufts;
2670 local int inflate_trees_bits OF((
2671 uIntf *, /* 19 code lengths */
2672 uIntf *, /* bits tree desired/actual depth */
2673 inflate_huft * FAR *, /* bits tree result */
2674 z_stream *)); /* for zalloc, zfree functions */
2676 local int inflate_trees_dynamic OF((
2677 uInt, /* number of literal/length codes */
2678 uInt, /* number of distance codes */
2679 uIntf *, /* that many (total) code lengths */
2680 uIntf *, /* literal desired/actual bit depth */
2681 uIntf *, /* distance desired/actual bit depth */
2682 inflate_huft * FAR *, /* literal/length tree result */
2683 inflate_huft * FAR *, /* distance tree result */
2684 z_stream *)); /* for zalloc, zfree functions */
2686 local int inflate_trees_fixed OF((
2687 uIntf *, /* literal desired/actual bit depth */
2688 uIntf *, /* distance desired/actual bit depth */
2689 inflate_huft * FAR *, /* literal/length tree result */
2690 inflate_huft * FAR *)); /* distance tree result */
2692 local int inflate_trees_free OF((
2693 inflate_huft *, /* tables to free */
2694 z_stream *)); /* for zfree function */
2698 /* infcodes.h -- header to use infcodes.c
2699 * Copyright (C) 1995 Mark Adler
2700 * For conditions of distribution and use, see copyright notice in zlib.h
2703 /* WARNING: this file should *not* be used by applications. It is
2704 part of the implementation of the compression library and is
2705 subject to change. Applications should only use zlib.h.
2708 struct inflate_codes_state;
2709 typedef struct inflate_codes_state FAR inflate_codes_statef;
2711 local inflate_codes_statef *inflate_codes_new OF((
2713 inflate_huft *, inflate_huft *,
2716 local int inflate_codes OF((
2717 inflate_blocks_statef *,
2721 local void inflate_codes_free OF((
2722 inflate_codes_statef *,
2727 /* inflate.c -- zlib interface to inflate modules
2728 * Copyright (C) 1995 Mark Adler
2729 * For conditions of distribution and use, see copyright notice in zlib.h
2732 /* inflate private state */
2733 struct internal_state {
2737 METHOD, /* waiting for method byte */
2738 FLAG, /* waiting for flag byte */
2739 BLOCKS, /* decompressing blocks */
2740 CHECK4, /* four check bytes to go */
2741 CHECK3, /* three check bytes to go */
2742 CHECK2, /* two check bytes to go */
2743 CHECK1, /* one check byte to go */
2744 DONE, /* finished check, done */
2745 BAD} /* got an error--stay here */
2746 mode; /* current inflate mode */
2748 /* mode dependent information */
2750 uInt method; /* if FLAGS, method byte */
2752 uLong was; /* computed check value */
2753 uLong need; /* stream check value */
2754 } check; /* if CHECK, check values to compare */
2755 uInt marker; /* if BAD, inflateSync's marker bytes count */
2756 } sub; /* submode */
2758 /* mode independent information */
2759 int nowrap; /* flag for no wrapper */
2760 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2761 inflate_blocks_statef
2762 *blocks; /* current inflate_blocks state */
2772 if (z == Z_NULL || z->state == Z_NULL)
2773 return Z_STREAM_ERROR;
2774 z->total_in = z->total_out = 0;
2776 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2777 inflate_blocks_reset(z->state->blocks, z, &c);
2778 Trace((stderr, "inflate: reset\n"));
2788 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2789 return Z_STREAM_ERROR;
2790 if (z->state->blocks != Z_NULL)
2791 inflate_blocks_free(z->state->blocks, z, &c);
2792 ZFREE(z, z->state, sizeof(struct internal_state));
2794 Trace((stderr, "inflate: end\n"));
2799 int inflateInit2(z, w)
2803 /* initialize state */
2805 return Z_STREAM_ERROR;
2806 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2807 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2808 if ((z->state = (struct internal_state FAR *)
2809 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2811 z->state->blocks = Z_NULL;
2813 /* handle undocumented nowrap option (no zlib header or check) */
2814 z->state->nowrap = 0;
2818 z->state->nowrap = 1;
2821 /* set window size */
2822 if (w < 8 || w > 15)
2825 return Z_STREAM_ERROR;
2827 z->state->wbits = (uInt)w;
2829 /* create inflate_blocks state */
2830 if ((z->state->blocks =
2831 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2837 Trace((stderr, "inflate: allocated\n"));
2848 return inflateInit2(z, DEF_WBITS);
2852 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2853 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2862 if (z == Z_NULL || z->next_in == Z_NULL)
2863 return Z_STREAM_ERROR;
2865 while (1) switch (z->state->mode)
2869 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2871 z->state->mode = BAD;
2872 z->msg = "unknown compression method";
2873 z->state->sub.marker = 5; /* can't try inflateSync */
2876 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2878 z->state->mode = BAD;
2879 z->msg = "invalid window size";
2880 z->state->sub.marker = 5; /* can't try inflateSync */
2883 z->state->mode = FLAG;
2886 if ((b = NEXTBYTE) & 0x20)
2888 z->state->mode = BAD;
2889 z->msg = "invalid reserved bit";
2890 z->state->sub.marker = 5; /* can't try inflateSync */
2893 if (((z->state->sub.method << 8) + b) % 31)
2895 z->state->mode = BAD;
2896 z->msg = "incorrect header check";
2897 z->state->sub.marker = 5; /* can't try inflateSync */
2900 Trace((stderr, "inflate: zlib header ok\n"));
2901 z->state->mode = BLOCKS;
2903 r = inflate_blocks(z->state->blocks, z, r);
2904 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2905 r = inflate_packet_flush(z->state->blocks);
2906 if (r == Z_DATA_ERROR)
2908 z->state->mode = BAD;
2909 z->state->sub.marker = 0; /* can try inflateSync */
2912 if (r != Z_STREAM_END)
2915 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2916 if (z->state->nowrap)
2918 z->state->mode = DONE;
2921 z->state->mode = CHECK4;
2924 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2925 z->state->mode = CHECK3;
2928 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2929 z->state->mode = CHECK2;
2932 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2933 z->state->mode = CHECK1;
2936 z->state->sub.check.need += (uLong)NEXTBYTE;
2938 if (z->state->sub.check.was != z->state->sub.check.need)
2940 z->state->mode = BAD;
2941 z->msg = "incorrect data check";
2942 z->state->sub.marker = 5; /* can't try inflateSync */
2945 Trace((stderr, "inflate: zlib check ok\n"));
2946 z->state->mode = DONE;
2948 return Z_STREAM_END;
2950 return Z_DATA_ERROR;
2952 return Z_STREAM_ERROR;
2956 if (f != Z_PACKET_FLUSH)
2958 z->state->mode = BAD;
2959 z->state->sub.marker = 0; /* can try inflateSync */
2960 return Z_DATA_ERROR;
2964 * This subroutine adds the data at next_in/avail_in to the output history
2965 * without performing any output. The output buffer must be "caught up";
2966 * i.e. no pending output (hence s->read equals s->write), and the state must
2967 * be BLOCKS (i.e. we should be willing to see the start of a series of
2968 * BLOCKS). On exit, the output will also be caught up, and the checksum
2969 * will have been updated if need be.
2972 int inflateIncomp(z)
2975 if (z->state->mode != BLOCKS)
2976 return Z_DATA_ERROR;
2977 return inflate_addhistory(z->state->blocks, z);
2984 uInt n; /* number of bytes to look at */
2985 Bytef *p; /* pointer to bytes */
2986 uInt m; /* number of marker bytes found in a row */
2987 uLong r, w; /* temporaries to save total_in and total_out */
2990 if (z == Z_NULL || z->state == Z_NULL)
2991 return Z_STREAM_ERROR;
2992 if (z->state->mode != BAD)
2994 z->state->mode = BAD;
2995 z->state->sub.marker = 0;
2997 if ((n = z->avail_in) == 0)
3000 m = z->state->sub.marker;
3005 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3015 z->total_in += p - z->next_in;
3018 z->state->sub.marker = m;
3020 /* return no joy or set up to restart on a new block */
3022 return Z_DATA_ERROR;
3023 r = z->total_in; w = z->total_out;
3025 z->total_in = r; z->total_out = w;
3026 z->state->mode = BLOCKS;
3034 /* infutil.h -- types and macros common to blocks and codes
3035 * Copyright (C) 1995 Mark Adler
3036 * For conditions of distribution and use, see copyright notice in zlib.h
3039 /* WARNING: this file should *not* be used by applications. It is
3040 part of the implementation of the compression library and is
3041 subject to change. Applications should only use zlib.h.
3044 /* inflate blocks semi-private state */
3045 struct inflate_blocks_state {
3049 TYPE, /* get type bits (3, including end bit) */
3050 LENS, /* get lengths for stored */
3051 STORED, /* processing stored block */
3052 TABLE, /* get table lengths */
3053 BTREE, /* get bit lengths tree for a dynamic block */
3054 DTREE, /* get length, distance trees for a dynamic block */
3055 CODES, /* processing fixed or dynamic block */
3056 DRY, /* output remaining window bytes */
3057 DONEB, /* finished last block, done */
3058 BADB} /* got a data error--stuck here */
3059 mode; /* current inflate_block mode */
3061 /* mode dependent information */
3063 uInt left; /* if STORED, bytes left to copy */
3065 uInt table; /* table lengths (14 bits) */
3066 uInt index; /* index into blens (or border) */
3067 uIntf *blens; /* bit lengths of codes */
3068 uInt bb; /* bit length tree depth */
3069 inflate_huft *tb; /* bit length decoding tree */
3070 int nblens; /* # elements allocated at blens */
3071 } trees; /* if DTREE, decoding info for trees */
3073 inflate_huft *tl, *td; /* trees to free */
3074 inflate_codes_statef
3076 } decode; /* if CODES, current state */
3077 } sub; /* submode */
3078 uInt last; /* true if this block is the last block */
3080 /* mode independent information */
3081 uInt bitk; /* bits in bit buffer */
3082 uLong bitb; /* bit buffer */
3083 Bytef *window; /* sliding window */
3084 Bytef *end; /* one byte after sliding window */
3085 Bytef *read; /* window read pointer */
3086 Bytef *write; /* window write pointer */
3087 check_func checkfn; /* check function */
3088 uLong check; /* check on output */
3093 /* defines for inflate input/output */
3094 /* update pointers and return */
3095 #define UPDBITS {s->bitb=b;s->bitk=k;}
3096 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3097 #define UPDOUT {s->write=q;}
3098 #define UPDATE {UPDBITS UPDIN UPDOUT}
3099 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3100 /* get bytes and bits */
3101 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3102 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3103 #define NEXTBYTE (n--,*p++)
3104 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3105 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3107 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3108 #define LOADOUT {q=s->write;m=WAVAIL;}
3109 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3110 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3111 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3112 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3113 /* load local pointers */
3114 #define LOAD {LOADIN LOADOUT}
3116 /* And'ing with mask[n] masks the lower n bits */
3117 local uInt inflate_mask[] = {
3119 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3120 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3123 /* copy as much as possible from the sliding window to the output area */
3124 local int inflate_flush OF((
3125 inflate_blocks_statef *,
3130 /* inffast.h -- header to use inffast.c
3131 * Copyright (C) 1995 Mark Adler
3132 * For conditions of distribution and use, see copyright notice in zlib.h
3135 /* WARNING: this file should *not* be used by applications. It is
3136 part of the implementation of the compression library and is
3137 subject to change. Applications should only use zlib.h.
3140 local int inflate_fast OF((
3145 inflate_blocks_statef *,
3150 /* infblock.c -- interpret and process block types to last block
3151 * Copyright (C) 1995 Mark Adler
3152 * For conditions of distribution and use, see copyright notice in zlib.h
3155 /* Table for deflate from PKZIP's appnote.txt. */
3156 local uInt border[] = { /* Order of the bit length code lengths */
3157 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3160 Notes beyond the 1.93a appnote.txt:
3162 1. Distance pointers never point before the beginning of the output
3164 2. Distance pointers can point back across blocks, up to 32k away.
3165 3. There is an implied maximum of 7 bits for the bit length table and
3166 15 bits for the actual data.
3167 4. If only one code exists, then it is encoded using one bit. (Zero
3168 would be more efficient, but perhaps a little confusing.) If two
3169 codes exist, they are coded using one bit each (0 and 1).
3170 5. There is no way of sending zero distance codes--a dummy must be
3171 sent if there are none. (History: a pre 2.0 version of PKZIP would
3172 store blocks with no distance codes, but this was discovered to be
3173 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3174 zero distance codes, which is sent as one code of zero bits in
3176 6. There are up to 286 literal/length codes. Code 256 represents the
3177 end-of-block. Note however that the static length tree defines
3178 288 codes just to fill out the Huffman codes. Codes 286 and 287
3179 cannot be used though, since there is no length base or extra bits
3180 defined for them. Similarily, there are up to 30 distance codes.
3181 However, static trees define 32 codes (all 5 bits) to fill out the
3182 Huffman codes, but the last two had better not show up in the data.
3183 7. Unzip can check dynamic Huffman blocks for complete code sets.
3184 The exception is that a single code would not be complete (see #4).
3185 8. The five bits following the block type is really the number of
3186 literal codes sent minus 257.
3187 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3188 (1+6+6). Therefore, to output three times the length, you output
3189 three codes (1+1+1), whereas to output four times the same length,
3190 you only need two codes (1+3). Hmm.
3191 10. In the tree reconstruction algorithm, Code = Code + Increment
3192 only if BitLength(i) is not zero. (Pretty obvious.)
3193 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3194 12. Note: length code 284 can represent 227-258, but length code 285
3195 really is 258. The last length deserves its own, short code
3196 since it gets used a lot in very redundant files. The length
3197 258 is special since 258 - 3 (the min match length) is 255.
3198 13. The literal/length and distance code bit lengths are read as a
3199 single stream of lengths. It is possible (and advantageous) for
3200 a repeat code (16, 17, or 18) to go across the boundary between
3201 the two sets of lengths.
3205 local void inflate_blocks_reset(s, z, c)
3206 inflate_blocks_statef *s;
3210 if (s->checkfn != Z_NULL)
3212 if (s->mode == BTREE || s->mode == DTREE)
3213 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3214 if (s->mode == CODES)
3216 inflate_codes_free(s->sub.decode.codes, z);
3217 inflate_trees_free(s->sub.decode.td, z);
3218 inflate_trees_free(s->sub.decode.tl, z);
3223 s->read = s->write = s->window;
3224 if (s->checkfn != Z_NULL)
3225 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3226 Trace((stderr, "inflate: blocks reset\n"));
3230 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
3235 inflate_blocks_statef *s;
3237 if ((s = (inflate_blocks_statef *)ZALLOC
3238 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3240 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3242 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3245 s->end = s->window + w;
3248 Trace((stderr, "inflate: blocks allocated\n"));
3249 inflate_blocks_reset(s, z, &s->check);
3254 local int inflate_blocks(s, z, r)
3255 inflate_blocks_statef *s;
3259 uInt t; /* temporary storage */
3260 uLong b; /* bit buffer */
3261 uInt k; /* bits in bit buffer */
3262 Bytef *p; /* input data pointer */
3263 uInt n; /* bytes available there */
3264 Bytef *q; /* output window write pointer */
3265 uInt m; /* bytes to end of window or read pointer */
3267 /* copy input/output information to locals (UPDATE macro restores) */
3270 /* process input based on current state */
3271 while (1) switch (s->mode)
3279 case 0: /* stored */
3280 Trace((stderr, "inflate: stored block%s\n",
3281 s->last ? " (last)" : ""));
3283 t = k & 7; /* go to byte boundary */
3285 s->mode = LENS; /* get length of stored block */
3288 Trace((stderr, "inflate: fixed codes block%s\n",
3289 s->last ? " (last)" : ""));
3292 inflate_huft *tl, *td;
3294 inflate_trees_fixed(&bl, &bd, &tl, &td);
3295 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3296 if (s->sub.decode.codes == Z_NULL)
3301 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3302 s->sub.decode.td = Z_NULL;
3307 case 2: /* dynamic */
3308 Trace((stderr, "inflate: dynamic codes block%s\n",
3309 s->last ? " (last)" : ""));
3313 case 3: /* illegal */
3316 z->msg = "invalid block type";
3323 if (((~b) >> 16) != (b & 0xffff))
3326 z->msg = "invalid stored block lengths";
3330 s->sub.left = (uInt)b & 0xffff;
3331 b = k = 0; /* dump bits */
3332 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3333 s->mode = s->sub.left ? STORED : TYPE;
3345 if ((s->sub.left -= t) != 0)
3347 Tracev((stderr, "inflate: stored end, %lu total out\n",
3348 z->total_out + (q >= s->read ? q - s->read :
3349 (s->end - s->read) + (q - s->window))));
3350 s->mode = s->last ? DRY : TYPE;
3354 s->sub.trees.table = t = (uInt)b & 0x3fff;
3355 #ifndef PKZIP_BUG_WORKAROUND
3356 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3359 z->msg = "too many length or distance symbols";
3364 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3367 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3372 s->sub.trees.nblens = t;
3374 s->sub.trees.index = 0;
3375 Tracev((stderr, "inflate: table sizes ok\n"));
3378 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3381 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3384 while (s->sub.trees.index < 19)
3385 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3386 s->sub.trees.bb = 7;
3387 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3388 &s->sub.trees.tb, z);
3392 if (r == Z_DATA_ERROR)
3396 s->sub.trees.index = 0;
3397 Tracev((stderr, "inflate: bits tree ok\n"));
3400 while (t = s->sub.trees.table,
3401 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3406 t = s->sub.trees.bb;
3408 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3409 t = h->word.what.Bits;
3414 s->sub.trees.blens[s->sub.trees.index++] = c;
3416 else /* c == 16..18 */
3418 i = c == 18 ? 7 : c - 14;
3419 j = c == 18 ? 11 : 3;
3422 j += (uInt)b & inflate_mask[i];
3424 i = s->sub.trees.index;
3425 t = s->sub.trees.table;
3426 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3430 z->msg = "invalid bit length repeat";
3434 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3436 s->sub.trees.blens[i++] = c;
3438 s->sub.trees.index = i;
3441 inflate_trees_free(s->sub.trees.tb, z);
3442 s->sub.trees.tb = Z_NULL;
3445 inflate_huft *tl, *td;
3446 inflate_codes_statef *c;
3448 bl = 9; /* must be <= 9 for lookahead assumptions */
3449 bd = 6; /* must be <= 9 for lookahead assumptions */
3450 t = s->sub.trees.table;
3451 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3452 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3455 if (t == (uInt)Z_DATA_ERROR)
3460 Tracev((stderr, "inflate: trees ok\n"));
3461 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3463 inflate_trees_free(td, z);
3464 inflate_trees_free(tl, z);
3468 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3469 s->sub.decode.codes = c;
3470 s->sub.decode.tl = tl;
3471 s->sub.decode.td = td;
3476 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3477 return inflate_flush(s, z, r);
3479 inflate_codes_free(s->sub.decode.codes, z);
3480 inflate_trees_free(s->sub.decode.td, z);
3481 inflate_trees_free(s->sub.decode.tl, z);
3483 Tracev((stderr, "inflate: codes end, %lu total out\n",
3484 z->total_out + (q >= s->read ? q - s->read :
3485 (s->end - s->read) + (q - s->window))));
3491 if (k > 7) /* return unused byte, if any */
3493 Assert(k < 16, "inflate_codes grabbed too many bytes")
3496 p--; /* can always return one */
3501 if (s->read != s->write)
3517 local int inflate_blocks_free(s, z, c)
3518 inflate_blocks_statef *s;
3522 inflate_blocks_reset(s, z, c);
3523 ZFREE(z, s->window, s->end - s->window);
3524 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3525 Trace((stderr, "inflate: blocks freed\n"));
3530 * This subroutine adds the data at next_in/avail_in to the output history
3531 * without performing any output. The output buffer must be "caught up";
3532 * i.e. no pending output (hence s->read equals s->write), and the state must
3533 * be BLOCKS (i.e. we should be willing to see the start of a series of
3534 * BLOCKS). On exit, the output will also be caught up, and the checksum
3535 * will have been updated if need be.
3537 local int inflate_addhistory(s, z)
3538 inflate_blocks_statef *s;
3541 uLong b; /* bit buffer */ /* NOT USED HERE */
3542 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3543 uInt t; /* temporary storage */
3544 Bytef *p; /* input data pointer */
3545 uInt n; /* bytes available there */
3546 Bytef *q; /* output window write pointer */
3547 uInt m; /* bytes to end of window or read pointer */
3549 if (s->read != s->write)
3550 return Z_STREAM_ERROR;
3551 if (s->mode != TYPE)
3552 return Z_DATA_ERROR;
3554 /* we're ready to rock */
3556 /* while there is input ready, copy to output buffer, moving
3557 * pointers as needed.
3560 t = n; /* how many to do */
3561 /* is there room until end of buffer? */
3563 /* update check information */
3564 if (s->checkfn != Z_NULL)
3565 s->check = (*s->checkfn)(s->check, q, t);
3571 s->read = q; /* drag read pointer forward */
3572 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
3574 s->read = q = s->window;
3584 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3585 * a `stored' block type value but not the (zero) length bytes.
3587 local int inflate_packet_flush(s)
3588 inflate_blocks_statef *s;
3590 if (s->mode != LENS)
3591 return Z_DATA_ERROR;
3598 /* inftrees.c -- generate Huffman trees for efficient decoding
3599 * Copyright (C) 1995 Mark Adler
3600 * For conditions of distribution and use, see copyright notice in zlib.h
3603 /* simplify the use of the inflate_huft type with some defines */
3604 #define base more.Base
3605 #define next more.Next
3606 #define exop word.what.Exop
3607 #define bits word.what.Bits
3610 local int huft_build OF((
3611 uIntf *, /* code lengths in bits */
3612 uInt, /* number of codes */
3613 uInt, /* number of "simple" codes */
3614 uIntf *, /* list of base values for non-simple codes */
3615 uIntf *, /* list of extra bits for non-simple codes */
3616 inflate_huft * FAR*,/* result: starting table */
3617 uIntf *, /* maximum lookup bits (returns actual) */
3618 z_stream *)); /* for zalloc function */
3620 local voidpf falloc OF((
3621 voidpf, /* opaque pointer (not used) */
3622 uInt, /* number of items */
3623 uInt)); /* size of item */
3625 local void ffree OF((
3626 voidpf q, /* opaque pointer (not used) */
3627 voidpf p, /* what to free (not used) */
3628 uInt n)); /* number of bytes (not used) */
3630 /* Tables for deflate from PKZIP's appnote.txt. */
3631 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3632 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3633 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3634 /* actually lengths - 2; also see note #13 above about 258 */
3635 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3636 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3637 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3638 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3639 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3640 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3641 8193, 12289, 16385, 24577};
3642 local uInt cpdext[] = { /* Extra bits for distance codes */
3643 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3644 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3648 Huffman code decoding is performed using a multi-level table lookup.
3649 The fastest way to decode is to simply build a lookup table whose
3650 size is determined by the longest code. However, the time it takes
3651 to build this table can also be a factor if the data being decoded
3652 is not very long. The most common codes are necessarily the
3653 shortest codes, so those codes dominate the decoding time, and hence
3654 the speed. The idea is you can have a shorter table that decodes the
3655 shorter, more probable codes, and then point to subsidiary tables for
3656 the longer codes. The time it costs to decode the longer codes is
3657 then traded against the time it takes to make longer tables.
3659 This results of this trade are in the variables lbits and dbits
3660 below. lbits is the number of bits the first level table for literal/
3661 length codes can decode in one step, and dbits is the same thing for
3662 the distance codes. Subsequent tables are also less than or equal to
3663 those sizes. These values may be adjusted either when all of the
3664 codes are shorter than that, in which case the longest code length in
3665 bits is used, or when the shortest code is *longer* than the requested
3666 table size, in which case the length of the shortest code in bits is
3669 There are two different values for the two tables, since they code a
3670 different number of possibilities each. The literal/length table
3671 codes 286 possible values, or in a flat code, a little over eight
3672 bits. The distance table codes 30 possible values, or a little less
3673 than five bits, flat. The optimum values for speed end up being
3674 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3675 The optimum values may differ though from machine to machine, and
3676 possibly even between compilers. Your mileage may vary.
3680 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3681 #define BMAX 15 /* maximum bit length of any code */
3682 #define N_MAX 288 /* maximum number of codes in any set */
3688 local int huft_build(b, n, s, d, e, t, m, zs)
3689 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3690 uInt n; /* number of codes (assumed <= N_MAX) */
3691 uInt s; /* number of simple-valued codes (0..s-1) */
3692 uIntf *d; /* list of base values for non-simple codes */
3693 uIntf *e; /* list of extra bits for non-simple codes */
3694 inflate_huft * FAR *t; /* result: starting table */
3695 uIntf *m; /* maximum lookup bits, returns actual */
3696 z_stream *zs; /* for zalloc function */
3697 /* Given a list of code lengths and a maximum table size, make a set of
3698 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3699 if the given code set is incomplete (the tables are still built in this
3700 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3701 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3704 uInt a; /* counter for codes of length k */
3705 uInt c[BMAX+1]; /* bit length count table */
3706 uInt f; /* i repeats in table every f entries */
3707 int g; /* maximum code length */
3708 int h; /* table level */
3709 register uInt i; /* counter, current code */
3710 register uInt j; /* counter */
3711 register int k; /* number of bits in current code */
3712 int l; /* bits per table (returned in m) */
3713 register uIntf *p; /* pointer into c[], b[], or v[] */
3714 inflate_huft *q; /* points to current table */
3715 struct inflate_huft_s r; /* table entry for structure assignment */
3716 inflate_huft *u[BMAX]; /* table stack */
3717 uInt v[N_MAX]; /* values in order of bit length */
3718 register int w; /* bits before this table == (l * h) */
3719 uInt x[BMAX+1]; /* bit offsets, then code stack */
3720 uIntf *xp; /* pointer into x */
3721 int y; /* number of dummy codes added */
3722 uInt z; /* number of entries in current table */
3725 /* Generate counts for each bit length */
3727 #define C0 *p++ = 0;
3728 #define C2 C0 C0 C0 C0
3729 #define C4 C2 C2 C2 C2
3730 C4 /* clear c[]--assume BMAX+1 is 16 */
3733 c[*p++]++; /* assume all entries <= BMAX */
3735 if (c[0] == n) /* null input--all zero length codes */
3737 *t = (inflate_huft *)Z_NULL;
3743 /* Find minimum and maximum length, bound *m by those */
3745 for (j = 1; j <= BMAX; j++)
3748 k = j; /* minimum code length */
3751 for (i = BMAX; i; i--)
3754 g = i; /* maximum code length */
3760 /* Adjust last length count to fill out codes, if needed */
3761 for (y = 1 << j; j < i; j++, y <<= 1)
3762 if ((y -= c[j]) < 0)
3763 return Z_DATA_ERROR;
3764 if ((y -= c[i]) < 0)
3765 return Z_DATA_ERROR;
3769 /* Generate starting offsets into the value table for each length */
3771 p = c + 1; xp = x + 2;
3772 while (--i) { /* note that i == g from above */
3773 *xp++ = (j += *p++);
3777 /* Make a table of values in order of bit lengths */
3780 if ((j = *p++) != 0)
3785 /* Generate the Huffman codes and for each, make the table entries */
3786 x[0] = i = 0; /* first Huffman code is zero */
3787 p = v; /* grab values in bit order */
3788 h = -1; /* no tables yet--level -1 */
3789 w = -l; /* bits decoded == (l * h) */
3790 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3791 q = (inflate_huft *)Z_NULL; /* ditto */
3794 /* go through the bit lengths (k already is bits in shortest code) */
3800 /* here i is the Huffman code of length k bits for value *p */
3801 /* make tables up to required level */
3805 w += l; /* previous table always l bits */
3807 /* compute minimum size table less than or equal to l bits */
3808 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3809 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3810 { /* too few codes for k-w bit table */
3811 f -= a + 1; /* deduct codes from patterns left */
3814 while (++j < z) /* try smaller tables up to z bits */
3816 if ((f <<= 1) <= *++xp)
3817 break; /* enough codes to use up j bits */
3818 f -= *xp; /* else deduct codes from patterns */
3821 z = 1 << j; /* table entries for j-bit table */
3823 /* allocate and link in new table */
3824 if ((q = (inflate_huft *)ZALLOC
3825 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3828 inflate_trees_free(u[0], zs);
3829 return Z_MEM_ERROR; /* not enough memory */
3831 q->word.Nalloc = z + 1;
3833 inflate_hufts += z + 1;
3835 *t = q + 1; /* link to list for huft_free() */
3836 *(t = &(q->next)) = Z_NULL;
3837 u[h] = ++q; /* table starts after link */
3839 /* connect to last table, if there is one */
3842 x[h] = i; /* save pattern for backing up */
3843 r.bits = (Byte)l; /* bits to dump before this table */
3844 r.exop = (Byte)j; /* bits in this table */
3845 r.next = q; /* pointer to this table */
3846 j = i >> (w - l); /* (get around Turbo C bug) */
3847 u[h-1][j] = r; /* connect to last table */
3851 /* set up table entry in r */
3852 r.bits = (Byte)(k - w);
3854 r.exop = 128 + 64; /* out of values--invalid code */
3857 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3858 r.base = *p++; /* simple code is just the value */
3862 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3863 r.base = d[*p++ - s];
3866 /* fill code-like entries with r */
3868 for (j = i >> w; j < z; j += f)
3871 /* backwards increment the k-bit code i */
3872 for (j = 1 << (k - 1); i & j; j >>= 1)
3876 /* backup over finished tables */
3877 while ((i & ((1 << w) - 1)) != x[h])
3879 h--; /* don't need to update q */
3886 /* Return Z_BUF_ERROR if we were given an incomplete table */
3887 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3891 local int inflate_trees_bits(c, bb, tb, z)
3892 uIntf *c; /* 19 code lengths */
3893 uIntf *bb; /* bits tree desired/actual depth */
3894 inflate_huft * FAR *tb; /* bits tree result */
3895 z_stream *z; /* for zfree function */
3899 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3900 if (r == Z_DATA_ERROR)
3901 z->msg = "oversubscribed dynamic bit lengths tree";
3902 else if (r == Z_BUF_ERROR)
3904 inflate_trees_free(*tb, z);
3905 z->msg = "incomplete dynamic bit lengths tree";
3912 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3913 uInt nl; /* number of literal/length codes */
3914 uInt nd; /* number of distance codes */
3915 uIntf *c; /* that many (total) code lengths */
3916 uIntf *bl; /* literal desired/actual bit depth */
3917 uIntf *bd; /* distance desired/actual bit depth */
3918 inflate_huft * FAR *tl; /* literal/length tree result */
3919 inflate_huft * FAR *td; /* distance tree result */
3920 z_stream *z; /* for zfree function */
3924 /* build literal/length tree */
3925 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3927 if (r == Z_DATA_ERROR)
3928 z->msg = "oversubscribed literal/length tree";
3929 else if (r == Z_BUF_ERROR)
3931 inflate_trees_free(*tl, z);
3932 z->msg = "incomplete literal/length tree";
3938 /* build distance tree */
3939 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3941 if (r == Z_DATA_ERROR)
3942 z->msg = "oversubscribed literal/length tree";
3943 else if (r == Z_BUF_ERROR) {
3944 #ifdef PKZIP_BUG_WORKAROUND
3948 inflate_trees_free(*td, z);
3949 z->msg = "incomplete literal/length tree";
3952 inflate_trees_free(*tl, z);
3962 /* build fixed tables only once--keep them here */
3963 local int fixed_lock = 0;
3964 local int fixed_built = 0;
3965 #define FIXEDH 530 /* number of hufts used by fixed tables */
3966 local uInt fixed_left = FIXEDH;
3967 local inflate_huft fixed_mem[FIXEDH];
3968 local uInt fixed_bl;
3969 local uInt fixed_bd;
3970 local inflate_huft *fixed_tl;
3971 local inflate_huft *fixed_td;
3974 local voidpf falloc(q, n, s)
3975 voidpf q; /* opaque pointer (not used) */
3976 uInt n; /* number of items */
3977 uInt s; /* size of item */
3979 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
3980 "inflate_trees falloc overflow");
3981 if (q) s++; /* to make some compilers happy */
3983 return (voidpf)(fixed_mem + fixed_left);
3987 local void ffree(q, p, n)
3992 Assert(0, "inflate_trees ffree called!");
3993 if (q) q = p; /* to make some compilers happy */
3997 local int inflate_trees_fixed(bl, bd, tl, td)
3998 uIntf *bl; /* literal desired/actual bit depth */
3999 uIntf *bd; /* distance desired/actual bit depth */
4000 inflate_huft * FAR *tl; /* literal/length tree result */
4001 inflate_huft * FAR *td; /* distance tree result */
4003 /* build fixed tables if not built already--lock out other instances */
4004 while (++fixed_lock > 1)
4008 int k; /* temporary variable */
4009 unsigned c[288]; /* length list for huft_build */
4010 z_stream z; /* for falloc function */
4012 /* set up fake z_stream for memory routines */
4018 for (k = 0; k < 144; k++)
4020 for (; k < 256; k++)
4022 for (; k < 280; k++)
4024 for (; k < 288; k++)
4027 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4029 /* distance table */
4030 for (k = 0; k < 30; k++)
4033 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4047 local int inflate_trees_free(t, z)
4048 inflate_huft *t; /* table to free */
4049 z_stream *z; /* for zfree function */
4050 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4051 list of the tables it made, with the links in a dummy first entry of
4054 register inflate_huft *p, *q;
4056 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4061 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4068 /* infcodes.c -- process literals and length/distance pairs
4069 * Copyright (C) 1995 Mark Adler
4070 * For conditions of distribution and use, see copyright notice in zlib.h
4073 /* simplify the use of the inflate_huft type with some defines */
4074 #define base more.Base
4075 #define next more.Next
4076 #define exop word.what.Exop
4077 #define bits word.what.Bits
4079 /* inflate codes private state */
4080 struct inflate_codes_state {
4083 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4084 START, /* x: set up for LEN */
4085 LEN, /* i: get length/literal/eob next */
4086 LENEXT, /* i: getting length extra (have base) */
4087 DIST, /* i: get distance next */
4088 DISTEXT, /* i: getting distance extra */
4089 COPY, /* o: copying bytes in window, waiting for space */
4090 LIT, /* o: got literal, waiting for output space */
4091 WASH, /* o: got eob, possibly still output waiting */
4092 END, /* x: got eob and all data flushed */
4093 BADCODE} /* x: got error */
4094 mode; /* current inflate_codes mode */
4096 /* mode dependent information */
4100 inflate_huft *tree; /* pointer into tree */
4101 uInt need; /* bits needed */
4102 } code; /* if LEN or DIST, where in tree */
4103 uInt lit; /* if LIT, literal */
4105 uInt get; /* bits to get for extra */
4106 uInt dist; /* distance back to copy from */
4107 } copy; /* if EXT or COPY, where and how much */
4108 } sub; /* submode */
4110 /* mode independent information */
4111 Byte lbits; /* ltree bits decoded per branch */
4112 Byte dbits; /* dtree bits decoder per branch */
4113 inflate_huft *ltree; /* literal/length/eob tree */
4114 inflate_huft *dtree; /* distance tree */
4119 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4121 inflate_huft *tl, *td;
4124 inflate_codes_statef *c;
4126 if ((c = (inflate_codes_statef *)
4127 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4130 c->lbits = (Byte)bl;
4131 c->dbits = (Byte)bd;
4134 Tracev((stderr, "inflate: codes new\n"));
4140 local int inflate_codes(s, z, r)
4141 inflate_blocks_statef *s;
4145 uInt j; /* temporary storage */
4146 inflate_huft *t; /* temporary pointer */
4147 uInt e; /* extra bits or operation */
4148 uLong b; /* bit buffer */
4149 uInt k; /* bits in bit buffer */
4150 Bytef *p; /* input data pointer */
4151 uInt n; /* bytes available there */
4152 Bytef *q; /* output window write pointer */
4153 uInt m; /* bytes to end of window or read pointer */
4154 Bytef *f; /* pointer to copy strings from */
4155 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4157 /* copy input/output information to locals (UPDATE macro restores) */
4160 /* process input and output based on current state */
4161 while (1) switch (c->mode)
4162 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4163 case START: /* x: set up for LEN */
4165 if (m >= 258 && n >= 10)
4168 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4172 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4177 c->sub.code.need = c->lbits;
4178 c->sub.code.tree = c->ltree;
4180 case LEN: /* i: get length/literal/eob next */
4181 j = c->sub.code.need;
4183 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4185 e = (uInt)(t->exop);
4186 if (e == 0) /* literal */
4188 c->sub.lit = t->base;
4189 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4190 "inflate: literal '%c'\n" :
4191 "inflate: literal 0x%02x\n", t->base));
4195 if (e & 16) /* length */
4197 c->sub.copy.get = e & 15;
4202 if ((e & 64) == 0) /* next table */
4204 c->sub.code.need = e;
4205 c->sub.code.tree = t->next;
4208 if (e & 32) /* end of block */
4210 Tracevv((stderr, "inflate: end of block\n"));
4214 c->mode = BADCODE; /* invalid code */
4215 z->msg = "invalid literal/length code";
4218 case LENEXT: /* i: getting length extra (have base) */
4219 j = c->sub.copy.get;
4221 c->len += (uInt)b & inflate_mask[j];
4223 c->sub.code.need = c->dbits;
4224 c->sub.code.tree = c->dtree;
4225 Tracevv((stderr, "inflate: length %u\n", c->len));
4227 case DIST: /* i: get distance next */
4228 j = c->sub.code.need;
4230 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4232 e = (uInt)(t->exop);
4233 if (e & 16) /* distance */
4235 c->sub.copy.get = e & 15;
4236 c->sub.copy.dist = t->base;
4240 if ((e & 64) == 0) /* next table */
4242 c->sub.code.need = e;
4243 c->sub.code.tree = t->next;
4246 c->mode = BADCODE; /* invalid code */
4247 z->msg = "invalid distance code";
4250 case DISTEXT: /* i: getting distance extra */
4251 j = c->sub.copy.get;
4253 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4255 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4257 case COPY: /* o: copying bytes in window, waiting for space */
4258 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4259 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4260 s->end - (c->sub.copy.dist - (q - s->window)) :
4261 q - c->sub.copy.dist;
4263 f = q - c->sub.copy.dist;
4264 if ((uInt)(q - s->window) < c->sub.copy.dist)
4265 f = s->end - (c->sub.copy.dist - (q - s->window));
4277 case LIT: /* o: got literal, waiting for output space */
4282 case WASH: /* o: got eob, possibly more output */
4284 if (s->read != s->write)
4290 case BADCODE: /* x: got error */
4300 local void inflate_codes_free(c, z)
4301 inflate_codes_statef *c;
4304 ZFREE(z, c, sizeof(struct inflate_codes_state));
4305 Tracev((stderr, "inflate: codes free\n"));
4309 /* inflate_util.c -- data and routines common to blocks and codes
4310 * Copyright (C) 1995 Mark Adler
4311 * For conditions of distribution and use, see copyright notice in zlib.h
4314 /* copy as much as possible from the sliding window to the output area */
4315 local int inflate_flush(s, z, r)
4316 inflate_blocks_statef *s;
4323 /* local copies of source and destination pointers */
4327 /* compute number of bytes to copy as far as end of window */
4328 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4329 if (n > z->avail_out) n = z->avail_out;
4330 if (n && r == Z_BUF_ERROR) r = Z_OK;
4332 /* update counters */
4336 /* update check information */
4337 if (s->checkfn != Z_NULL)
4338 s->check = (*s->checkfn)(s->check, q, n);
4340 /* copy as far as end of window */
4347 /* see if more to copy at beginning of window */
4352 if (s->write == s->end)
4353 s->write = s->window;
4355 /* compute bytes to copy */
4356 n = (uInt)(s->write - q);
4357 if (n > z->avail_out) n = z->avail_out;
4358 if (n && r == Z_BUF_ERROR) r = Z_OK;
4360 /* update counters */
4364 /* update check information */
4365 if (s->checkfn != Z_NULL)
4366 s->check = (*s->checkfn)(s->check, q, n);
4376 /* update pointers */
4386 /* inffast.c -- process literals and length/distance pairs fast
4387 * Copyright (C) 1995 Mark Adler
4388 * For conditions of distribution and use, see copyright notice in zlib.h
4391 /* simplify the use of the inflate_huft type with some defines */
4392 #define base more.Base
4393 #define next more.Next
4394 #define exop word.what.Exop
4395 #define bits word.what.Bits
4397 /* macros for bit input with no checking and for returning unused bytes */
4398 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4399 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4401 /* Called with number of bytes left to write in window at least 258
4402 (the maximum string length) and number of input bytes available
4403 at least ten. The ten bytes are six bytes for the longest length/
4404 distance pair plus four bytes for overloading the bit buffer. */
4406 local int inflate_fast(bl, bd, tl, td, s, z)
4408 inflate_huft *tl, *td;
4409 inflate_blocks_statef *s;
4412 inflate_huft *t; /* temporary pointer */
4413 uInt e; /* extra bits or operation */
4414 uLong b; /* bit buffer */
4415 uInt k; /* bits in bit buffer */
4416 Bytef *p; /* input data pointer */
4417 uInt n; /* bytes available there */
4418 Bytef *q; /* output window write pointer */
4419 uInt m; /* bytes to end of window or read pointer */
4420 uInt ml; /* mask for literal/length tree */
4421 uInt md; /* mask for distance tree */
4422 uInt c; /* bytes to copy */
4423 uInt d; /* distance back to copy from */
4424 Bytef *r; /* copy source pointer */
4426 /* load input, output, bit values */
4429 /* initialize masks */
4430 ml = inflate_mask[bl];
4431 md = inflate_mask[bd];
4433 /* do until not enough input or output space for fast loop */
4434 do { /* assume called with m >= 258 && n >= 10 */
4435 /* get literal/length code */
4436 GRABBITS(20) /* max bits for literal/length code */
4437 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4440 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4441 "inflate: * literal '%c'\n" :
4442 "inflate: * literal 0x%02x\n", t->base));
4443 *q++ = (Byte)t->base;
4451 /* get extra bits for length */
4453 c = t->base + ((uInt)b & inflate_mask[e]);
4455 Tracevv((stderr, "inflate: * length %u\n", c));
4457 /* decode distance base of block to copy */
4458 GRABBITS(15); /* max bits for distance code */
4459 e = (t = td + ((uInt)b & md))->exop;
4464 /* get extra bits to add to distance base */
4466 GRABBITS(e) /* get extra bits (up to 13) */
4467 d = t->base + ((uInt)b & inflate_mask[e]);
4469 Tracevv((stderr, "inflate: * distance %u\n", d));
4473 if ((uInt)(q - s->window) >= d) /* offset before dest */
4476 *q++ = *r++; c--; /* minimum count is three, */
4477 *q++ = *r++; c--; /* so unroll loop a little */
4479 else /* else offset after destination */
4481 e = d - (q - s->window); /* bytes from offset to end */
4482 r = s->end - e; /* pointer to offset */
4483 if (c > e) /* if source crosses, */
4485 c -= e; /* copy to end of window */
4489 r = s->window; /* copy rest from start of window */
4492 do { /* copy all or what's left */
4497 else if ((e & 64) == 0)
4498 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4501 z->msg = "invalid distance code";
4504 return Z_DATA_ERROR;
4511 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4514 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4515 "inflate: * literal '%c'\n" :
4516 "inflate: * literal 0x%02x\n", t->base));
4517 *q++ = (Byte)t->base;
4524 Tracevv((stderr, "inflate: * end of block\n"));
4527 return Z_STREAM_END;
4531 z->msg = "invalid literal/length code";
4534 return Z_DATA_ERROR;
4537 } while (m >= 258 && n >= 10);
4539 /* not enough input or output--restore pointers and return */
4547 /* zutil.c -- target dependent utility functions for the compression library
4548 * Copyright (C) 1995 Jean-loup Gailly.
4549 * For conditions of distribution and use, see copyright notice in zlib.h
4552 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
4554 char *zlib_version = ZLIB_VERSION;
4556 char *z_errmsg[] = {
4557 "stream end", /* Z_STREAM_END 1 */
4559 "file error", /* Z_ERRNO (-1) */
4560 "stream error", /* Z_STREAM_ERROR (-2) */
4561 "data error", /* Z_DATA_ERROR (-3) */
4562 "insufficient memory", /* Z_MEM_ERROR (-4) */
4563 "buffer error", /* Z_BUF_ERROR (-5) */
4568 /* adler32.c -- compute the Adler-32 checksum of a data stream
4569 * Copyright (C) 1995 Mark Adler
4570 * For conditions of distribution and use, see copyright notice in zlib.h
4573 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
4575 #define BASE 65521L /* largest prime smaller than 65536 */
4577 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4579 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4580 #define DO2(buf) DO1(buf); DO1(buf);
4581 #define DO4(buf) DO2(buf); DO2(buf);
4582 #define DO8(buf) DO4(buf); DO4(buf);
4583 #define DO16(buf) DO8(buf); DO8(buf);
4585 /* ========================================================================= */
4586 uLong adler32(adler, buf, len)
4591 unsigned long s1 = adler & 0xffff;
4592 unsigned long s2 = (adler >> 16) & 0xffff;
4595 if (buf == Z_NULL) return 1L;
4598 k = len < NMAX ? len : NMAX;
4610 return (s2 << 16) | s1;