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
14 * $Id: zlib.c,v 1.6 1997/04/30 05:41:19 paulus Exp $
18 * ==FILEVERSION 970421==
20 * This marker is used by the Linux installation script to determine
21 * whether an up-to-date version of this file is already installed.
25 /* zutil.h -- internal interface and configuration of the compression library
26 * Copyright (C) 1995 Jean-loup Gailly.
27 * For conditions of distribution and use, see copyright notice in zlib.h
30 /* WARNING: this file should *not* be used by applications. It is
31 part of the implementation of the compression library and is
32 subject to change. Applications should only use zlib.h.
35 /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */
44 /* compile with -Dlocal if your debugger can't find static symbols */
48 typedef unsigned char uch;
50 typedef unsigned short ush;
52 typedef unsigned long ulg;
54 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
56 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
57 /* To be used only when the state is known to be valid */
60 #define NULL ((void *) 0)
63 /* common constants */
68 # define DEF_WBITS MAX_WBITS
70 /* default windowBits for decompression. MAX_WBITS is for compression only */
72 #if MAX_MEM_LEVEL >= 8
73 # define DEF_MEM_LEVEL 8
75 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
77 /* default memLevel */
79 #define STORED_BLOCK 0
80 #define STATIC_TREES 1
82 /* The three kinds of block type */
86 /* The minimum and maximum match lengths */
90 #if defined(KERNEL) || defined(_KERNEL)
91 #include <sys/types.h>
93 #include <sys/systm.h>
94 # define zmemcpy(d, s, n) bcopy((s), (d), (n))
95 # define zmemzero bzero
98 #if defined(__KERNEL__)
99 /* Assume this is Linux */
100 #include <linux/string.h>
101 #define zmemcpy memcpy
102 #define zmemzero(dest, len) memset(dest, 0, len)
104 #else /* not kernel */
105 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
109 # define zmemcpy memcpy
110 # define zmemzero(dest, len) memset(dest, 0, len)
112 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
113 extern void zmemzero OF((Bytef* dest, uInt len));
115 #endif /* __KERNEL__ */
118 /* Diagnostic functions */
124 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
125 # define Trace(x) fprintf x
126 # define Tracev(x) {if (verbose) fprintf x ;}
127 # define Tracevv(x) {if (verbose>1) fprintf x ;}
128 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
129 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
131 # define Assert(cond,msg)
136 # define Tracecv(c,x)
140 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
142 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
143 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
145 #define ZALLOC(strm, items, size) \
146 (*((strm)->zalloc))((strm)->opaque, (items), (size))
147 #define ZALLOC_INIT(strm, items, size) \
148 (*((strm)->zalloc_init))((strm)->opaque, (items), (size))
149 #define ZFREE(strm, addr, size) \
150 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
151 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
153 /* deflate.h -- internal compression state
154 * Copyright (C) 1995 Jean-loup Gailly
155 * For conditions of distribution and use, see copyright notice in zlib.h
158 /* WARNING: this file should *not* be used by applications. It is
159 part of the implementation of the compression library and is
160 subject to change. Applications should only use zlib.h.
165 /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */
167 /* ===========================================================================
168 * Internal compression state.
176 #define LENGTH_CODES 29
177 /* number of length codes, not counting the special END_BLOCK code */
180 /* number of literal bytes 0..255 */
182 #define L_CODES (LITERALS+1+LENGTH_CODES)
183 /* number of Literal or Length codes, including the END_BLOCK code */
186 /* number of distance codes */
189 /* number of codes used to transfer the bit lengths */
191 #define HEAP_SIZE (2*L_CODES+1)
192 /* maximum heap size */
195 /* All codes must not exceed MAX_BITS bits */
197 #define INIT_STATE 42
198 #define BUSY_STATE 113
199 #define FLUSH_STATE 124
200 #define FINISH_STATE 666
204 /* Data structure describing a single value and its code string. */
205 typedef struct ct_data_s {
207 ush freq; /* frequency count */
208 ush code; /* bit string */
211 ush dad; /* father node in Huffman tree */
212 ush len; /* length of bit string */
221 typedef struct static_tree_desc_s static_tree_desc;
223 typedef struct tree_desc_s {
224 ct_data *dyn_tree; /* the dynamic tree */
225 int max_code; /* largest code with non zero frequency */
226 static_tree_desc *stat_desc; /* the corresponding static tree */
230 typedef Pos FAR Posf;
231 typedef unsigned IPos;
233 /* A Pos is an index in the character window. We use short instead of int to
234 * save space in the various tables. IPos is used only for parameter passing.
237 typedef struct deflate_state {
238 z_stream *strm; /* pointer back to this zlib stream */
239 int status; /* as the name implies */
240 Bytef *pending_buf; /* output still pending */
241 Bytef *pending_out; /* next pending byte to output to the stream */
242 int pending; /* nb of bytes in the pending buffer */
243 uLong adler; /* adler32 of uncompressed data */
244 int noheader; /* suppress zlib header and adler32 */
245 Byte data_type; /* UNKNOWN, Z_BINARY or ASCII */
246 Byte method; /* STORED (for zip only) or DEFLATED */
247 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */
249 /* used by deflate.c: */
251 uInt w_size; /* LZ77 window size (32K by default) */
252 uInt w_bits; /* log2(w_size) (8..16) */
253 uInt w_mask; /* w_size - 1 */
256 /* Sliding window. Input bytes are read into the second half of the window,
257 * and move to the first half later to keep a dictionary of at least wSize
258 * bytes. With this organization, matches are limited to a distance of
259 * wSize-MAX_MATCH bytes, but this ensures that IO is always
260 * performed with a length multiple of the block size. Also, it limits
261 * the window size to 64K, which is quite useful on MSDOS.
262 * To do: use the user input buffer as sliding window.
266 /* Actual size of window: 2*wSize, except when the user input buffer
267 * is directly used as sliding window.
271 /* Link to older string with same hash index. To limit the size of this
272 * array to 64K, this link is maintained only for the last 32K strings.
273 * An index in this array is thus a window index modulo 32K.
276 Posf *head; /* Heads of the hash chains or NIL. */
278 uInt ins_h; /* hash index of string to be inserted */
279 uInt hash_size; /* number of elements in hash table */
280 uInt hash_bits; /* log2(hash_size) */
281 uInt hash_mask; /* hash_size-1 */
284 /* Number of bits by which ins_h must be shifted at each input
285 * step. It must be such that after MIN_MATCH steps, the oldest
286 * byte no longer takes part in the hash key, that is:
287 * hash_shift * MIN_MATCH >= hash_bits
291 /* Window position at the beginning of the current output block. Gets
292 * negative when the window is moved backwards.
295 uInt match_length; /* length of best match */
296 IPos prev_match; /* previous match */
297 int match_available; /* set if previous match exists */
298 uInt strstart; /* start of string to insert */
299 uInt match_start; /* start of matching string */
300 uInt lookahead; /* number of valid bytes ahead in window */
303 /* Length of the best match at previous step. Matches not greater than this
304 * are discarded. This is used in the lazy match evaluation.
307 uInt max_chain_length;
308 /* To speed up deflation, hash chains are never searched beyond this
309 * length. A higher limit improves compression ratio but degrades the
314 /* Attempt to find a better match only when the current match is strictly
315 * smaller than this value. This mechanism is used only for compression
318 # define max_insert_length max_lazy_match
319 /* Insert new strings in the hash table only if the match length is not
320 * greater than this length. This saves time but degrades compression.
321 * max_insert_length is used only for compression levels <= 3.
324 int level; /* compression level (1..9) */
325 int strategy; /* favor or force Huffman coding*/
328 /* Use a faster search when the previous match is longer than this */
330 int nice_match; /* Stop searching when current match exceeds this */
332 /* used by trees.c: */
333 /* Didn't use ct_data typedef below to supress compiler warning */
334 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
335 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
336 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
338 struct tree_desc_s l_desc; /* desc. for literal tree */
339 struct tree_desc_s d_desc; /* desc. for distance tree */
340 struct tree_desc_s bl_desc; /* desc. for bit length tree */
342 ush bl_count[MAX_BITS+1];
343 /* number of codes at each bit length for an optimal tree */
345 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
346 int heap_len; /* number of elements in the heap */
347 int heap_max; /* element of largest frequency */
348 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
349 * The same heap array is used to build all trees.
352 uch depth[2*L_CODES+1];
353 /* Depth of each subtree used as tie breaker for trees of equal frequency
356 uchf *l_buf; /* buffer for literals or lengths */
359 /* Size of match buffer for literals/lengths. There are 4 reasons for
360 * limiting lit_bufsize to 64K:
361 * - frequencies can be kept in 16 bit counters
362 * - if compression is not successful for the first block, all input
363 * data is still in the window so we can still emit a stored block even
364 * when input comes from standard input. (This can also be done for
365 * all blocks if lit_bufsize is not greater than 32K.)
366 * - if compression is not successful for a file smaller than 64K, we can
367 * even emit a stored file instead of a stored block (saving 5 bytes).
368 * This is applicable only for zip (not gzip or zlib).
369 * - creating new Huffman trees less frequently may not provide fast
370 * adaptation to changes in the input data statistics. (Take for
371 * example a binary file with poorly compressible code followed by
372 * a highly compressible string table.) Smaller buffer sizes give
373 * fast adaptation but have of course the overhead of transmitting
374 * trees more frequently.
375 * - I can't count above 4
378 uInt last_lit; /* running index in l_buf */
381 /* Buffer for distances. To simplify the code, d_buf and l_buf have
382 * the same number of elements. To use different lengths, an extra flag
383 * array would be necessary.
386 ulg opt_len; /* bit length of current block with optimal trees */
387 ulg static_len; /* bit length of current block with static trees */
388 ulg compressed_len; /* total bit length of compressed file */
389 uInt matches; /* number of string matches in current block */
390 int last_eob_len; /* bit length of EOB code for last block */
393 ulg bits_sent; /* bit length of the compressed data */
397 /* Output buffer. bits are inserted starting at the bottom (least
401 /* Number of valid bits in bi_buf. All bits above the last valid bit
405 uInt blocks_in_packet;
406 /* Number of blocks produced since the last time Z_PACKET_FLUSH
412 /* Output a byte on the stream.
413 * IN assertion: there is enough room in pending_buf.
415 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
418 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
419 /* Minimum amount of lookahead, except at the end of the input file.
420 * See deflate.c for comments about the MIN_MATCH+1.
423 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
424 /* In order to simplify the code, particularly on 16 bit machines, match
425 * distances are limited to MAX_DIST instead of WSIZE.
429 local void ct_init OF((deflate_state *s));
430 local int ct_tally OF((deflate_state *s, int dist, int lc));
431 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
433 local void ct_align OF((deflate_state *s));
434 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
436 local void ct_stored_type_only OF((deflate_state *s));
440 /* deflate.c -- compress data using the deflation algorithm
441 * Copyright (C) 1995 Jean-loup Gailly.
442 * For conditions of distribution and use, see copyright notice in zlib.h
448 * The "deflation" process depends on being able to identify portions
449 * of the input text which are identical to earlier input (within a
450 * sliding window trailing behind the input currently being processed).
452 * The most straightforward technique turns out to be the fastest for
453 * most input files: try all possible matches and select the longest.
454 * The key feature of this algorithm is that insertions into the string
455 * dictionary are very simple and thus fast, and deletions are avoided
456 * completely. Insertions are performed at each input character, whereas
457 * string matches are performed only when the previous match ends. So it
458 * is preferable to spend more time in matches to allow very fast string
459 * insertions and avoid deletions. The matching algorithm for small
460 * strings is inspired from that of Rabin & Karp. A brute force approach
461 * is used to find longer strings when a small match has been found.
462 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
463 * (by Leonid Broukhis).
464 * A previous version of this file used a more sophisticated algorithm
465 * (by Fiala and Greene) which is guaranteed to run in linear amortized
466 * time, but has a larger average cost, uses more memory and is patented.
467 * However the F&G algorithm may be faster for some highly redundant
468 * files if the parameter max_chain_length (described below) is too large.
472 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
473 * I found it in 'freeze' written by Leonid Broukhis.
474 * Thanks to many people for bug reports and testing.
478 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
479 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
481 * A description of the Rabin and Karp algorithm is given in the book
482 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
484 * Fiala,E.R., and Greene,D.H.
485 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
489 /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */
491 local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
493 If you use the zlib library in a product, an acknowledgment is welcome
494 in the documentation of your product. If for some reason you cannot
495 include such an acknowledgment, I would appreciate that you keep this
496 copyright string in the executable of your product.
500 /* Tail of hash chains */
503 # define TOO_FAR 4096
505 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
507 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
508 /* Minimum amount of lookahead, except at the end of the input file.
509 * See deflate.c for comments about the MIN_MATCH+1.
512 /* Values for max_lazy_match, good_match and max_chain_length, depending on
513 * the desired pack level (0..9). The values given below have been tuned to
514 * exclude worst case performance for pathological files. Better values may be
515 * found for specific files.
518 typedef struct config_s {
519 ush good_length; /* reduce lazy search above this match length */
520 ush max_lazy; /* do not perform lazy search above this match length */
521 ush nice_length; /* quit search above this match length */
525 local config configuration_table[10] = {
526 /* good lazy nice chain */
527 /* 0 */ {0, 0, 0, 0}, /* store only */
528 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
529 /* 2 */ {4, 5, 16, 8},
530 /* 3 */ {4, 6, 32, 32},
532 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
533 /* 5 */ {8, 16, 32, 32},
534 /* 6 */ {8, 16, 128, 128},
535 /* 7 */ {8, 32, 128, 256},
536 /* 8 */ {32, 128, 258, 1024},
537 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
539 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
540 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
545 /* result of memcmp for equal strings */
547 /* ===========================================================================
548 * Prototypes for local functions.
551 local void fill_window OF((deflate_state *s));
552 local int deflate_fast OF((deflate_state *s, int flush));
553 local int deflate_slow OF((deflate_state *s, int flush));
554 local void lm_init OF((deflate_state *s));
555 local int longest_match OF((deflate_state *s, IPos cur_match));
556 local void putShortMSB OF((deflate_state *s, uInt b));
557 local void flush_pending OF((z_stream *strm));
558 local int read_buf OF((z_stream *strm, charf *buf, unsigned size));
560 void match_init OF((void)); /* asm code initialization */
564 local void check_match OF((deflate_state *s, IPos start, IPos match,
569 /* ===========================================================================
570 * Update a hash value with the given input byte
571 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
572 * input characters, so that a running hash key can be computed from the
573 * previous key instead of complete recalculation each time.
575 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
578 /* ===========================================================================
579 * Insert string str in the dictionary and set match_head to the previous head
580 * of the hash chain (the most recent string with same hash key). Return
581 * the previous length of the hash chain.
582 * IN assertion: all calls to to INSERT_STRING are made with consecutive
583 * input characters and the first MIN_MATCH bytes of str are valid
584 * (except for the last MIN_MATCH-1 bytes of the input file).
586 #define INSERT_STRING(s, str, match_head) \
587 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
588 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
589 s->head[s->ins_h] = (str))
591 /* ===========================================================================
592 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
593 * prev[] will be initialized on the fly.
595 #define CLEAR_HASH(s) \
596 s->head[s->hash_size-1] = NIL; \
597 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
599 /* ========================================================================= */
600 int deflateInit (strm, level)
604 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
606 /* To do: ignore strm->next_in if we use it as window */
609 /* ========================================================================= */
610 int deflateInit2 (strm, level, method, windowBits, memLevel,
611 strategy, minCompression)
623 if (strm == Z_NULL) return Z_STREAM_ERROR;
626 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
627 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
629 if (level == Z_DEFAULT_COMPRESSION) level = 6;
631 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
633 windowBits = -windowBits;
635 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
636 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
637 return Z_STREAM_ERROR;
639 s = (deflate_state *) ZALLOC_INIT(strm, 1, sizeof(deflate_state));
640 if (s == Z_NULL) return Z_MEM_ERROR;
641 strm->state = (struct internal_state FAR *)s;
644 s->noheader = noheader;
645 s->w_bits = windowBits;
646 s->w_size = 1 << s->w_bits;
647 s->w_mask = s->w_size - 1;
649 s->hash_bits = memLevel + 7;
650 s->hash_size = 1 << s->hash_bits;
651 s->hash_mask = s->hash_size - 1;
652 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
654 s->window = (Bytef *) ZALLOC_INIT(strm, s->w_size, 2*sizeof(Byte));
655 s->prev = (Posf *) ZALLOC_INIT(strm, s->w_size, sizeof(Pos));
656 s->head = (Posf *) ZALLOC_INIT(strm, s->hash_size, sizeof(Pos));
658 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
660 s->pending_buf = (uchf *) ZALLOC_INIT(strm, s->lit_bufsize, 2*sizeof(ush));
662 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
663 s->pending_buf == Z_NULL) {
664 strm->msg = z_errmsg[1-Z_MEM_ERROR];
668 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
669 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
670 /* We overlay pending_buf and d_buf+l_buf. This works since the average
671 * output size for (length,distance) codes is <= 32 bits (worst case
676 s->strategy = strategy;
677 s->method = (Byte)method;
678 s->minCompr = minCompression;
679 s->blocks_in_packet = 0;
681 return deflateReset(strm);
684 /* ========================================================================= */
685 int deflateReset (strm)
690 if (strm == Z_NULL || strm->state == Z_NULL ||
691 strm->zalloc == Z_NULL || strm->zfree == Z_NULL ||
692 strm->zalloc_init == Z_NULL) return Z_STREAM_ERROR;
694 strm->total_in = strm->total_out = 0;
695 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
696 strm->data_type = Z_UNKNOWN;
698 s = (deflate_state *)strm->state;
700 s->pending_out = s->pending_buf;
702 if (s->noheader < 0) {
703 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
705 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
714 /* =========================================================================
715 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
716 * IN assertion: the stream state is correct and there is enough room in
719 local void putShortMSB (s, b)
723 put_byte(s, (Byte)(b >> 8));
724 put_byte(s, (Byte)(b & 0xff));
727 /* =========================================================================
728 * Flush as much pending output as possible.
730 local void flush_pending(strm)
733 deflate_state *state = (deflate_state *) strm->state;
734 unsigned len = state->pending;
736 if (len > strm->avail_out) len = strm->avail_out;
737 if (len == 0) return;
739 if (strm->next_out != NULL) {
740 zmemcpy(strm->next_out, state->pending_out, len);
741 strm->next_out += len;
743 state->pending_out += len;
744 strm->total_out += len;
745 strm->avail_out -= len;
746 state->pending -= len;
747 if (state->pending == 0) {
748 state->pending_out = state->pending_buf;
752 /* ========================================================================= */
753 int deflate (strm, flush)
757 deflate_state *state = (deflate_state *) strm->state;
759 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
761 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
762 ERR_RETURN(strm, Z_STREAM_ERROR);
764 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
766 state->strm = strm; /* just in case */
768 /* Write the zlib header */
769 if (state->status == INIT_STATE) {
771 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
772 uInt level_flags = (state->level-1) >> 1;
774 if (level_flags > 3) level_flags = 3;
775 header |= (level_flags << 6);
776 header += 31 - (header % 31);
778 state->status = BUSY_STATE;
779 putShortMSB(state, header);
782 /* Flush as much pending output as possible */
783 if (state->pending != 0) {
785 if (strm->avail_out == 0) return Z_OK;
788 /* If we came back in here to get the last output from
789 * a previous flush, we're done for now.
791 if (state->status == FLUSH_STATE) {
792 state->status = BUSY_STATE;
793 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
797 /* User must not provide more input after the first FINISH: */
798 if (state->status == FINISH_STATE && strm->avail_in != 0) {
799 ERR_RETURN(strm, Z_BUF_ERROR);
802 /* Start a new block or continue the current one.
804 if (strm->avail_in != 0 || state->lookahead != 0 ||
805 (flush == Z_FINISH && state->status != FINISH_STATE)) {
808 if (flush == Z_FINISH) {
809 state->status = FINISH_STATE;
811 if (state->level <= 3) {
812 quit = deflate_fast(state, flush);
814 quit = deflate_slow(state, flush);
816 if (quit || strm->avail_out == 0)
818 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
819 * of deflate should use the same flush parameter to make sure
820 * that the flush is complete. So we don't have to output an
821 * empty block here, this will be done at next call. This also
822 * ensures that for a very small output buffer, we emit at most
827 /* If a flush was requested, we have a little more to output now. */
828 if (flush != Z_NO_FLUSH && flush != Z_FINISH
829 && state->status != FINISH_STATE) {
831 case Z_PARTIAL_FLUSH:
835 /* Output just the 3-bit `stored' block type value,
836 but not a zero length. */
837 ct_stored_type_only(state);
840 ct_stored_block(state, (char*)0, 0L, 0);
841 /* For a full flush, this empty block will be recognized
842 * as a special marker by inflate_sync().
844 if (flush == Z_FULL_FLUSH) {
845 CLEAR_HASH(state); /* forget history */
849 if (strm->avail_out == 0) {
850 /* We'll have to come back to get the rest of the output;
851 * this ensures we don't output a second zero-length stored
852 * block (or whatever).
854 state->status = FLUSH_STATE;
859 Assert(strm->avail_out > 0, "bug2");
861 if (flush != Z_FINISH) return Z_OK;
862 if (state->noheader) return Z_STREAM_END;
864 /* Write the zlib trailer (adler32) */
865 putShortMSB(state, (uInt)(state->adler >> 16));
866 putShortMSB(state, (uInt)(state->adler & 0xffff));
868 /* If avail_out is zero, the application will call deflate again
871 state->noheader = -1; /* write the trailer only once! */
872 return state->pending != 0 ? Z_OK : Z_STREAM_END;
875 /* ========================================================================= */
876 int deflateEnd (strm)
879 deflate_state *state = (deflate_state *) strm->state;
881 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
883 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
884 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
885 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
886 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
888 ZFREE(strm, state, sizeof(deflate_state));
889 strm->state = Z_NULL;
894 /* ===========================================================================
895 * Read a new buffer from the current input stream, update the adler32
896 * and total number of bytes read.
898 local int read_buf(strm, buf, size)
903 unsigned len = strm->avail_in;
904 deflate_state *state = (deflate_state *) strm->state;
906 if (len > size) len = size;
907 if (len == 0) return 0;
909 strm->avail_in -= len;
911 if (!state->noheader) {
912 state->adler = adler32(state->adler, strm->next_in, len);
914 zmemcpy(buf, strm->next_in, len);
915 strm->next_in += len;
916 strm->total_in += len;
921 /* ===========================================================================
922 * Initialize the "longest match" routines for a new zlib stream
924 local void lm_init (s)
927 s->window_size = (ulg)2L*s->w_size;
931 /* Set the default configuration parameters:
933 s->max_lazy_match = configuration_table[s->level].max_lazy;
934 s->good_match = configuration_table[s->level].good_length;
935 s->nice_match = configuration_table[s->level].nice_length;
936 s->max_chain_length = configuration_table[s->level].max_chain;
941 s->match_length = MIN_MATCH-1;
942 s->match_available = 0;
945 match_init(); /* initialize the asm code */
949 /* ===========================================================================
950 * Set match_start to the longest match starting at the given string and
951 * return its length. Matches shorter or equal to prev_length are discarded,
952 * in which case the result is equal to prev_length and match_start is
954 * IN assertions: cur_match is the head of the hash chain for the current
955 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
958 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
959 * match.S. The code will be functionally equivalent.
961 local int longest_match(s, cur_match)
963 IPos cur_match; /* current match */
965 unsigned chain_length = s->max_chain_length;/* max hash chain length */
966 register Bytef *scan = s->window + s->strstart; /* current string */
967 register Bytef *match; /* matched string */
968 register int len; /* length of current match */
969 int best_len = s->prev_length; /* best match length so far */
970 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
971 s->strstart - (IPos)MAX_DIST(s) : NIL;
972 /* Stop when cur_match becomes <= limit. To simplify the code,
973 * we prevent matches with the string of window index 0.
975 Posf *prev = s->prev;
976 uInt wmask = s->w_mask;
979 /* Compare two bytes at a time. Note: this is not always beneficial.
980 * Try with and without -DUNALIGNED_OK to check.
982 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
983 register ush scan_start = *(ushf*)scan;
984 register ush scan_end = *(ushf*)(scan+best_len-1);
986 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
987 register Byte scan_end1 = scan[best_len-1];
988 register Byte scan_end = scan[best_len];
991 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
992 * It is easy to get rid of this optimization if necessary.
994 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
996 /* Do not waste too much time if we already have a good match: */
997 if (s->prev_length >= s->good_match) {
1000 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1003 Assert(cur_match < s->strstart, "no future");
1004 match = s->window + cur_match;
1006 /* Skip to next match if the match length cannot increase
1007 * or if the match length is less than 2:
1009 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1010 /* This code assumes sizeof(unsigned short) == 2. Do not use
1011 * UNALIGNED_OK if your compiler uses a different size.
1013 if (*(ushf*)(match+best_len-1) != scan_end ||
1014 *(ushf*)match != scan_start) continue;
1016 /* It is not necessary to compare scan[2] and match[2] since they are
1017 * always equal when the other bytes match, given that the hash keys
1018 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1019 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1020 * lookahead only every 4th comparison; the 128th check will be made
1021 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1022 * necessary to put more guard bytes at the end of the window, or
1023 * to check more often for insufficient lookahead.
1025 Assert(scan[2] == match[2], "scan[2]?");
1028 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1029 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1030 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1031 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1033 /* The funny "do {}" generates better code on most compilers */
1035 /* Here, scan <= window+strstart+257 */
1036 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1037 if (*scan == *match) scan++;
1039 len = (MAX_MATCH - 1) - (int)(strend-scan);
1040 scan = strend - (MAX_MATCH-1);
1042 #else /* UNALIGNED_OK */
1044 if (match[best_len] != scan_end ||
1045 match[best_len-1] != scan_end1 ||
1047 *++match != scan[1]) continue;
1049 /* The check at best_len-1 can be removed because it will be made
1050 * again later. (This heuristic is not always a win.)
1051 * It is not necessary to compare scan[2] and match[2] since they
1052 * are always equal when the other bytes match, given that
1053 * the hash keys are equal and that HASH_BITS >= 8.
1056 Assert(*scan == *match, "match[2]?");
1058 /* We check for insufficient lookahead only every 8th comparison;
1059 * the 256th check will be made at strstart+258.
1062 } while (*++scan == *++match && *++scan == *++match &&
1063 *++scan == *++match && *++scan == *++match &&
1064 *++scan == *++match && *++scan == *++match &&
1065 *++scan == *++match && *++scan == *++match &&
1068 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1070 len = MAX_MATCH - (int)(strend - scan);
1071 scan = strend - MAX_MATCH;
1073 #endif /* UNALIGNED_OK */
1075 if (len > best_len) {
1076 s->match_start = cur_match;
1078 if (len >= s->nice_match) break;
1080 scan_end = *(ushf*)(scan+best_len-1);
1082 scan_end1 = scan[best_len-1];
1083 scan_end = scan[best_len];
1086 } while ((cur_match = prev[cur_match & wmask]) > limit
1087 && --chain_length != 0);
1094 /* ===========================================================================
1095 * Check that the match at match_start is indeed a match.
1097 local void check_match(s, start, match, length)
1102 /* check that the match is indeed a match */
1103 if (memcmp((charf *)s->window + match,
1104 (charf *)s->window + start, length) != EQUAL) {
1106 " start %u, match %u, length %d\n",
1107 start, match, length);
1108 do { fprintf(stderr, "%c%c", s->window[match++],
1109 s->window[start++]); } while (--length != 0);
1110 z_error("invalid match");
1113 fprintf(stderr,"\\[%d,%d]", start-match, length);
1114 do { putc(s->window[start++], stderr); } while (--length != 0);
1118 # define check_match(s, start, match, length)
1121 /* ===========================================================================
1122 * Fill the window when the lookahead becomes insufficient.
1123 * Updates strstart and lookahead.
1125 * IN assertion: lookahead < MIN_LOOKAHEAD
1126 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1127 * At least one byte has been read, or avail_in == 0; reads are
1128 * performed for at least two bytes (required for the zip translate_eol
1129 * option -- not supported here).
1131 local void fill_window(s)
1134 register unsigned n, m;
1136 unsigned more; /* Amount of free space at the end of the window. */
1137 uInt wsize = s->w_size;
1140 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1142 /* Deal with !@#$% 64K limit: */
1143 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1145 } else if (more == (unsigned)(-1)) {
1146 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1147 * and lookahead == 1 (input done one byte at time)
1151 /* If the window is almost full and there is insufficient lookahead,
1152 * move the upper half to the lower one to make room in the upper half.
1154 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1156 /* By the IN assertion, the window is not empty so we can't confuse
1157 * more == 0 with more == 64K on a 16 bit machine.
1159 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1161 s->match_start -= wsize;
1162 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1164 s->block_start -= (long) wsize;
1166 /* Slide the hash table (could be avoided with 32 bit values
1167 at the expense of memory usage):
1173 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1180 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1181 /* If n is not on any hash chain, prev[n] is garbage but
1182 * its value will never be used.
1188 if (s->strm->avail_in == 0) return;
1190 /* If there was no sliding:
1191 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1192 * more == window_size - lookahead - strstart
1193 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1194 * => more >= window_size - 2*WSIZE + 2
1195 * In the BIG_MEM or MMAP case (not yet supported),
1196 * window_size == input_size + MIN_LOOKAHEAD &&
1197 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1198 * Otherwise, window_size == 2*WSIZE so more >= 2.
1199 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1201 Assert(more >= 2, "more < 2");
1203 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1207 /* Initialize the hash value now that we have some input: */
1208 if (s->lookahead >= MIN_MATCH) {
1209 s->ins_h = s->window[s->strstart];
1210 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1212 Call UPDATE_HASH() MIN_MATCH-3 more times
1215 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1216 * but this is not important since only literal bytes will be emitted.
1219 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1222 /* ===========================================================================
1223 * Flush the current block, with given end-of-file flag.
1224 * IN assertion: strstart is set to the end of the current match.
1226 #define FLUSH_BLOCK_ONLY(s, flush) { \
1227 ct_flush_block(s, (s->block_start >= 0L ? \
1228 (charf *)&s->window[(unsigned)s->block_start] : \
1229 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1230 s->block_start = s->strstart; \
1231 flush_pending(s->strm); \
1232 Tracev((stderr,"[FLUSH]")); \
1235 /* Same but force premature exit if necessary. */
1236 #define FLUSH_BLOCK(s, flush) { \
1237 FLUSH_BLOCK_ONLY(s, flush); \
1238 if (s->strm->avail_out == 0) return 1; \
1241 /* ===========================================================================
1242 * Compress as much as possible from the input stream, return true if
1243 * processing was terminated prematurely (no more input or output space).
1244 * This function does not perform lazy evaluationof matches and inserts
1245 * new strings in the dictionary only for unmatched strings or for short
1246 * matches. It is used only for the fast compression options.
1248 local int deflate_fast(s, flush)
1252 IPos hash_head = NIL; /* head of the hash chain */
1253 int bflush; /* set if current block must be flushed */
1255 s->prev_length = MIN_MATCH-1;
1258 /* Make sure that we always have enough lookahead, except
1259 * at the end of the input file. We need MAX_MATCH bytes
1260 * for the next match, plus MIN_MATCH bytes to insert the
1261 * string following the next match.
1263 if (s->lookahead < MIN_LOOKAHEAD) {
1265 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1267 if (s->lookahead == 0) break; /* flush the current block */
1270 /* Insert the string window[strstart .. strstart+2] in the
1271 * dictionary, and set hash_head to the head of the hash chain:
1273 if (s->lookahead >= MIN_MATCH) {
1274 INSERT_STRING(s, s->strstart, hash_head);
1277 /* Find the longest match, discarding those <= prev_length.
1278 * At this point we have always match_length < MIN_MATCH
1280 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1281 /* To simplify the code, we prevent matches with the string
1282 * of window index 0 (in particular we have to avoid a match
1283 * of the string with itself at the start of the input file).
1285 if (s->strategy != Z_HUFFMAN_ONLY) {
1286 s->match_length = longest_match (s, hash_head);
1288 /* longest_match() sets match_start */
1290 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1292 if (s->match_length >= MIN_MATCH) {
1293 check_match(s, s->strstart, s->match_start, s->match_length);
1295 bflush = ct_tally(s, s->strstart - s->match_start,
1296 s->match_length - MIN_MATCH);
1298 s->lookahead -= s->match_length;
1300 /* Insert new strings in the hash table only if the match length
1301 * is not too large. This saves time but degrades compression.
1303 if (s->match_length <= s->max_insert_length &&
1304 s->lookahead >= MIN_MATCH) {
1305 s->match_length--; /* string at strstart already in hash table */
1308 INSERT_STRING(s, s->strstart, hash_head);
1309 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1310 * always MIN_MATCH bytes ahead.
1312 } while (--s->match_length != 0);
1315 s->strstart += s->match_length;
1316 s->match_length = 0;
1317 s->ins_h = s->window[s->strstart];
1318 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1320 Call UPDATE_HASH() MIN_MATCH-3 more times
1322 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1323 * matter since it will be recomputed at next deflate call.
1327 /* No match, output a literal byte */
1328 Tracevv((stderr,"%c", s->window[s->strstart]));
1329 bflush = ct_tally (s, 0, s->window[s->strstart]);
1333 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1335 FLUSH_BLOCK(s, flush);
1336 return 0; /* normal exit */
1339 /* ===========================================================================
1340 * Same as above, but achieves better compression. We use a lazy
1341 * evaluation for matches: a match is finally adopted only if there is
1342 * no better match at the next window position.
1344 local int deflate_slow(s, flush)
1348 IPos hash_head = NIL; /* head of hash chain */
1349 int bflush; /* set if current block must be flushed */
1351 /* Process the input block. */
1353 /* Make sure that we always have enough lookahead, except
1354 * at the end of the input file. We need MAX_MATCH bytes
1355 * for the next match, plus MIN_MATCH bytes to insert the
1356 * string following the next match.
1358 if (s->lookahead < MIN_LOOKAHEAD) {
1360 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1362 if (s->lookahead == 0) break; /* flush the current block */
1365 /* Insert the string window[strstart .. strstart+2] in the
1366 * dictionary, and set hash_head to the head of the hash chain:
1368 if (s->lookahead >= MIN_MATCH) {
1369 INSERT_STRING(s, s->strstart, hash_head);
1372 /* Find the longest match, discarding those <= prev_length.
1374 s->prev_length = s->match_length, s->prev_match = s->match_start;
1375 s->match_length = MIN_MATCH-1;
1377 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1378 s->strstart - hash_head <= MAX_DIST(s)) {
1379 /* To simplify the code, we prevent matches with the string
1380 * of window index 0 (in particular we have to avoid a match
1381 * of the string with itself at the start of the input file).
1383 if (s->strategy != Z_HUFFMAN_ONLY) {
1384 s->match_length = longest_match (s, hash_head);
1386 /* longest_match() sets match_start */
1387 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1389 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1390 (s->match_length == MIN_MATCH &&
1391 s->strstart - s->match_start > TOO_FAR))) {
1393 /* If prev_match is also MIN_MATCH, match_start is garbage
1394 * but we will ignore the current match anyway.
1396 s->match_length = MIN_MATCH-1;
1399 /* If there was a match at the previous step and the current
1400 * match is not better, output the previous match:
1402 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1403 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1404 /* Do not insert strings in hash table beyond this. */
1406 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1408 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1409 s->prev_length - MIN_MATCH);
1411 /* Insert in hash table all strings up to the end of the match.
1412 * strstart-1 and strstart are already inserted. If there is not
1413 * enough lookahead, the last two strings are not inserted in
1416 s->lookahead -= s->prev_length-1;
1417 s->prev_length -= 2;
1419 if (++s->strstart <= max_insert) {
1420 INSERT_STRING(s, s->strstart, hash_head);
1422 } while (--s->prev_length != 0);
1423 s->match_available = 0;
1424 s->match_length = MIN_MATCH-1;
1427 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1429 } else if (s->match_available) {
1430 /* If there was no match at the previous position, output a
1431 * single literal. If there was a match but the current match
1432 * is longer, truncate the previous match to a single literal.
1434 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1435 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1436 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1440 if (s->strm->avail_out == 0) return 1;
1442 /* There is no previous match to compare with, wait for
1443 * the next step to decide.
1445 s->match_available = 1;
1450 Assert (flush != Z_NO_FLUSH, "no flush?");
1451 if (s->match_available) {
1452 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1453 ct_tally (s, 0, s->window[s->strstart-1]);
1454 s->match_available = 0;
1456 FLUSH_BLOCK(s, flush);
1462 /* trees.c -- output deflated data using Huffman coding
1463 * Copyright (C) 1995 Jean-loup Gailly
1464 * For conditions of distribution and use, see copyright notice in zlib.h
1470 * The "deflation" process uses several Huffman trees. The more
1471 * common source values are represented by shorter bit sequences.
1473 * Each code tree is stored in a compressed form which is itself
1474 * a Huffman encoding of the lengths of all the code strings (in
1475 * ascending order by source values). The actual code strings are
1476 * reconstructed from the lengths in the inflate process, as described
1477 * in the deflate specification.
1481 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1482 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1485 * Data Compression: Methods and Theory, pp. 49-50.
1486 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1490 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1493 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
1499 /* ===========================================================================
1503 #define MAX_BL_BITS 7
1504 /* Bit length codes must not exceed MAX_BL_BITS bits */
1506 #define END_BLOCK 256
1507 /* end of block literal code */
1510 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1512 #define REPZ_3_10 17
1513 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1515 #define REPZ_11_138 18
1516 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1518 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1519 = {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};
1521 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1522 = {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};
1524 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1525 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1527 local uch bl_order[BL_CODES]
1528 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1529 /* The lengths of the bit length codes are sent in order of decreasing
1530 * probability, to avoid transmitting the lengths for unused bit length codes.
1533 #define Buf_size (8 * 2*sizeof(char))
1534 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1535 * more than 16 bits on some systems.)
1538 /* ===========================================================================
1539 * Local data. These are initialized only once.
1540 * To do: initialize at compile time to be completely reentrant. ???
1543 local ct_data static_ltree[L_CODES+2];
1544 /* The static literal tree. Since the bit lengths are imposed, there is no
1545 * need for the L_CODES extra codes used during heap construction. However
1546 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1550 local ct_data static_dtree[D_CODES];
1551 /* The static distance tree. (Actually a trivial tree since all codes use
1555 local uch dist_code[512];
1556 /* distance codes. The first 256 values correspond to the distances
1557 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1558 * the 15 bit distances.
1561 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1562 /* length code for each normalized match length (0 == MIN_MATCH) */
1564 local int base_length[LENGTH_CODES];
1565 /* First normalized length for each code (0 = MIN_MATCH) */
1567 local int base_dist[D_CODES];
1568 /* First normalized distance for each code (0 = distance of 1) */
1570 struct static_tree_desc_s {
1571 ct_data *static_tree; /* static tree or NULL */
1572 intf *extra_bits; /* extra bits for each code or NULL */
1573 int extra_base; /* base index for extra_bits */
1574 int elems; /* max number of elements in the tree */
1575 int max_length; /* max bit length for the codes */
1578 local static_tree_desc static_l_desc =
1579 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1581 local static_tree_desc static_d_desc =
1582 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1584 local static_tree_desc static_bl_desc =
1585 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1587 /* ===========================================================================
1588 * Local (static) routines in this file.
1591 local void ct_static_init OF((void));
1592 local void init_block OF((deflate_state *s));
1593 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1594 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1595 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1596 local void build_tree OF((deflate_state *s, tree_desc *desc));
1597 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1598 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1599 local int build_bl_tree OF((deflate_state *s));
1600 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1602 local void compress_block OF((deflate_state *s, ct_data *ltree,
1604 local void set_data_type OF((deflate_state *s));
1605 local unsigned bi_reverse OF((unsigned value, int length));
1606 local void bi_windup OF((deflate_state *s));
1607 local void bi_flush OF((deflate_state *s));
1608 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1612 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1613 /* Send a code of the given tree. c and tree must not have side effects */
1615 #else /* DEBUG_ZLIB */
1616 # define send_code(s, c, tree) \
1617 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1618 send_bits(s, tree[c].Code, tree[c].Len); }
1621 #define d_code(dist) \
1622 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1623 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1624 * must not have side effects. dist_code[256] and dist_code[257] are never
1628 /* ===========================================================================
1629 * Output a short LSB first on the stream.
1630 * IN assertion: there is enough room in pendingBuf.
1632 #define put_short(s, w) { \
1633 put_byte(s, (uch)((w) & 0xff)); \
1634 put_byte(s, (uch)((ush)(w) >> 8)); \
1637 /* ===========================================================================
1638 * Send a value on a given number of bits.
1639 * IN assertion: length <= 16 and value fits in length bits.
1642 local void send_bits OF((deflate_state *s, int value, int length));
1644 local void send_bits(s, value, length)
1646 int value; /* value to send */
1647 int length; /* number of bits */
1649 Tracev((stderr," l %2d v %4x ", length, value));
1650 Assert(length > 0 && length <= 15, "invalid length");
1651 s->bits_sent += (ulg)length;
1653 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1654 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1655 * unused bits in value.
1657 if (s->bi_valid > (int)Buf_size - length) {
1658 s->bi_buf |= (value << s->bi_valid);
1659 put_short(s, s->bi_buf);
1660 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1661 s->bi_valid += length - Buf_size;
1663 s->bi_buf |= value << s->bi_valid;
1664 s->bi_valid += length;
1667 #else /* !DEBUG_ZLIB */
1669 #define send_bits(s, value, length) \
1670 { int len = length;\
1671 if (s->bi_valid > (int)Buf_size - len) {\
1673 s->bi_buf |= (val << s->bi_valid);\
1674 put_short(s, s->bi_buf);\
1675 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1676 s->bi_valid += len - Buf_size;\
1678 s->bi_buf |= (value) << s->bi_valid;\
1679 s->bi_valid += len;\
1682 #endif /* DEBUG_ZLIB */
1685 #define MAX(a,b) (a >= b ? a : b)
1686 /* the arguments must not have side effects */
1688 /* ===========================================================================
1689 * Initialize the various 'constant' tables.
1690 * To do: do this at compile time.
1692 local void ct_static_init()
1694 int n; /* iterates over tree elements */
1695 int bits; /* bit counter */
1696 int length; /* length value */
1697 int code; /* code value */
1698 int dist; /* distance index */
1699 ush bl_count[MAX_BITS+1];
1700 /* number of codes at each bit length for an optimal tree */
1702 /* Initialize the mapping length (0..255) -> length code (0..28) */
1704 for (code = 0; code < LENGTH_CODES-1; code++) {
1705 base_length[code] = length;
1706 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1707 length_code[length++] = (uch)code;
1710 Assert (length == 256, "ct_static_init: length != 256");
1711 /* Note that the length 255 (match length 258) can be represented
1712 * in two different ways: code 284 + 5 bits or code 285, so we
1713 * overwrite length_code[255] to use the best encoding:
1715 length_code[length-1] = (uch)code;
1717 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1719 for (code = 0 ; code < 16; code++) {
1720 base_dist[code] = dist;
1721 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1722 dist_code[dist++] = (uch)code;
1725 Assert (dist == 256, "ct_static_init: dist != 256");
1726 dist >>= 7; /* from now on, all distances are divided by 128 */
1727 for ( ; code < D_CODES; code++) {
1728 base_dist[code] = dist << 7;
1729 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1730 dist_code[256 + dist++] = (uch)code;
1733 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1735 /* Construct the codes of the static literal tree */
1736 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1738 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1739 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1740 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1741 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1742 /* Codes 286 and 287 do not exist, but we must include them in the
1743 * tree construction to get a canonical Huffman tree (longest code
1746 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1748 /* The static distance tree is trivial: */
1749 for (n = 0; n < D_CODES; n++) {
1750 static_dtree[n].Len = 5;
1751 static_dtree[n].Code = bi_reverse(n, 5);
1755 /* ===========================================================================
1756 * Initialize the tree data structures for a new zlib stream.
1758 local void ct_init(s)
1761 if (static_dtree[0].Len == 0) {
1762 ct_static_init(); /* To do: at compile time */
1765 s->compressed_len = 0L;
1767 s->l_desc.dyn_tree = s->dyn_ltree;
1768 s->l_desc.stat_desc = &static_l_desc;
1770 s->d_desc.dyn_tree = s->dyn_dtree;
1771 s->d_desc.stat_desc = &static_d_desc;
1773 s->bl_desc.dyn_tree = s->bl_tree;
1774 s->bl_desc.stat_desc = &static_bl_desc;
1778 s->last_eob_len = 8; /* enough lookahead for inflate */
1782 s->blocks_in_packet = 0;
1784 /* Initialize the first block of the first file: */
1788 /* ===========================================================================
1789 * Initialize a new block.
1791 local void init_block(s)
1794 int n; /* iterates over tree elements */
1796 /* Initialize the trees. */
1797 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1798 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1799 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1801 s->dyn_ltree[END_BLOCK].Freq = 1;
1802 s->opt_len = s->static_len = 0L;
1803 s->last_lit = s->matches = 0;
1807 /* Index within the heap array of least frequent node in the Huffman tree */
1810 /* ===========================================================================
1811 * Remove the smallest element from the heap and recreate the heap with
1812 * one less element. Updates heap and heap_len.
1814 #define pqremove(s, tree, top) \
1816 top = s->heap[SMALLEST]; \
1817 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1818 pqdownheap(s, tree, SMALLEST); \
1821 /* ===========================================================================
1822 * Compares to subtrees, using the tree depth as tie breaker when
1823 * the subtrees have equal frequency. This minimizes the worst case length.
1825 #define smaller(tree, n, m, depth) \
1826 (tree[n].Freq < tree[m].Freq || \
1827 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1829 /* ===========================================================================
1830 * Restore the heap property by moving down the tree starting at node k,
1831 * exchanging a node with the smallest of its two sons if necessary, stopping
1832 * when the heap property is re-established (each father smaller than its
1835 local void pqdownheap(s, tree, k)
1837 ct_data *tree; /* the tree to restore */
1838 int k; /* node to move down */
1841 int j = k << 1; /* left son of k */
1842 while (j <= s->heap_len) {
1843 /* Set j to the smallest of the two sons: */
1844 if (j < s->heap_len &&
1845 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1848 /* Exit if v is smaller than both sons */
1849 if (smaller(tree, v, s->heap[j], s->depth)) break;
1851 /* Exchange v with the smallest son */
1852 s->heap[k] = s->heap[j]; k = j;
1854 /* And continue down the tree, setting j to the left son of k */
1860 /* ===========================================================================
1861 * Compute the optimal bit lengths for a tree and update the total bit length
1862 * for the current block.
1863 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1864 * above are the tree nodes sorted by increasing frequency.
1865 * OUT assertions: the field len is set to the optimal bit length, the
1866 * array bl_count contains the frequencies for each bit length.
1867 * The length opt_len is updated; static_len is also updated if stree is
1870 local void gen_bitlen(s, desc)
1872 tree_desc *desc; /* the tree descriptor */
1874 ct_data *tree = desc->dyn_tree;
1875 int max_code = desc->max_code;
1876 ct_data *stree = desc->stat_desc->static_tree;
1877 intf *extra = desc->stat_desc->extra_bits;
1878 int base = desc->stat_desc->extra_base;
1879 int max_length = desc->stat_desc->max_length;
1880 int h; /* heap index */
1881 int n, m; /* iterate over the tree elements */
1882 int bits; /* bit length */
1883 int xbits; /* extra bits */
1884 ush f; /* frequency */
1885 int overflow = 0; /* number of elements with bit length too large */
1887 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1889 /* In a first pass, compute the optimal bit lengths (which may
1890 * overflow in the case of the bit length tree).
1892 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1894 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1896 bits = tree[tree[n].Dad].Len + 1;
1897 if (bits > max_length) bits = max_length, overflow++;
1898 tree[n].Len = (ush)bits;
1899 /* We overwrite tree[n].Dad which is no longer needed */
1901 if (n > max_code) continue; /* not a leaf node */
1903 s->bl_count[bits]++;
1905 if (n >= base) xbits = extra[n-base];
1907 s->opt_len += (ulg)f * (bits + xbits);
1908 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1910 if (overflow == 0) return;
1912 Trace((stderr,"\nbit length overflow\n"));
1913 /* This happens for example on obj2 and pic of the Calgary corpus */
1915 /* Find the first bit length which could increase: */
1917 bits = max_length-1;
1918 while (s->bl_count[bits] == 0) bits--;
1919 s->bl_count[bits]--; /* move one leaf down the tree */
1920 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1921 s->bl_count[max_length]--;
1922 /* The brother of the overflow item also moves one step up,
1923 * but this does not affect bl_count[max_length]
1926 } while (overflow > 0);
1928 /* Now recompute all bit lengths, scanning in increasing frequency.
1929 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1930 * lengths instead of fixing only the wrong ones. This idea is taken
1931 * from 'ar' written by Haruhiko Okumura.)
1933 for (bits = max_length; bits != 0; bits--) {
1934 n = s->bl_count[bits];
1937 if (m > max_code) continue;
1938 if (tree[m].Len != (unsigned) bits) {
1939 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1940 s->opt_len += ((long)bits - (long)tree[m].Len)
1941 *(long)tree[m].Freq;
1942 tree[m].Len = (ush)bits;
1949 /* ===========================================================================
1950 * Generate the codes for a given tree and bit counts (which need not be
1952 * IN assertion: the array bl_count contains the bit length statistics for
1953 * the given tree and the field len is set for all tree elements.
1954 * OUT assertion: the field code is set for all tree elements of non
1957 local void gen_codes (tree, max_code, bl_count)
1958 ct_data *tree; /* the tree to decorate */
1959 int max_code; /* largest code with non zero frequency */
1960 ushf *bl_count; /* number of codes at each bit length */
1962 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1963 ush code = 0; /* running code value */
1964 int bits; /* bit index */
1965 int n; /* code index */
1967 /* The distribution counts are first used to generate the code values
1968 * without bit reversal.
1970 for (bits = 1; bits <= MAX_BITS; bits++) {
1971 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1973 /* Check that the bit counts in bl_count are consistent. The last code
1976 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1977 "inconsistent bit counts");
1978 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1980 for (n = 0; n <= max_code; n++) {
1981 int len = tree[n].Len;
1982 if (len == 0) continue;
1983 /* Now reverse the bits */
1984 tree[n].Code = bi_reverse(next_code[len]++, len);
1986 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1987 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1991 /* ===========================================================================
1992 * Construct one Huffman tree and assigns the code bit strings and lengths.
1993 * Update the total bit length for the current block.
1994 * IN assertion: the field freq is set for all tree elements.
1995 * OUT assertions: the fields len and code are set to the optimal bit length
1996 * and corresponding code. The length opt_len is updated; static_len is
1997 * also updated if stree is not null. The field max_code is set.
1999 local void build_tree(s, desc)
2001 tree_desc *desc; /* the tree descriptor */
2003 ct_data *tree = desc->dyn_tree;
2004 ct_data *stree = desc->stat_desc->static_tree;
2005 int elems = desc->stat_desc->elems;
2006 int n, m; /* iterate over heap elements */
2007 int max_code = -1; /* largest code with non zero frequency */
2008 int node; /* new node being created */
2010 /* Construct the initial heap, with least frequent element in
2011 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2012 * heap[0] is not used.
2014 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2016 for (n = 0; n < elems; n++) {
2017 if (tree[n].Freq != 0) {
2018 s->heap[++(s->heap_len)] = max_code = n;
2025 /* The pkzip format requires that at least one distance code exists,
2026 * and that at least one bit should be sent even if there is only one
2027 * possible code. So to avoid special checks later on we force at least
2028 * two codes of non zero frequency.
2030 while (s->heap_len < 2) {
2031 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2032 tree[node].Freq = 1;
2034 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2035 /* node is 0 or 1 so it does not have extra bits */
2037 desc->max_code = max_code;
2039 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2040 * establish sub-heaps of increasing lengths:
2042 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2044 /* Construct the Huffman tree by repeatedly combining the least two
2047 node = elems; /* next internal node of the tree */
2049 pqremove(s, tree, n); /* n = node of least frequency */
2050 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2052 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2053 s->heap[--(s->heap_max)] = m;
2055 /* Create a new node father of n and m */
2056 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2057 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2058 tree[n].Dad = tree[m].Dad = (ush)node;
2060 if (tree == s->bl_tree) {
2061 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2062 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2065 /* and insert the new node in the heap */
2066 s->heap[SMALLEST] = node++;
2067 pqdownheap(s, tree, SMALLEST);
2069 } while (s->heap_len >= 2);
2071 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2073 /* At this point, the fields freq and dad are set. We can now
2074 * generate the bit lengths.
2076 gen_bitlen(s, (tree_desc *)desc);
2078 /* The field len is now set, we can generate the bit codes */
2079 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2082 /* ===========================================================================
2083 * Scan a literal or distance tree to determine the frequencies of the codes
2084 * in the bit length tree.
2086 local void scan_tree (s, tree, max_code)
2088 ct_data *tree; /* the tree to be scanned */
2089 int max_code; /* and its largest code of non zero frequency */
2091 int n; /* iterates over all tree elements */
2092 int prevlen = -1; /* last emitted length */
2093 int curlen; /* length of current code */
2094 int nextlen = tree[0].Len; /* length of next code */
2095 int count = 0; /* repeat count of the current code */
2096 int max_count = 7; /* max repeat count */
2097 int min_count = 4; /* min repeat count */
2099 if (nextlen == 0) max_count = 138, min_count = 3;
2100 tree[max_code+1].Len = (ush)0xffff; /* guard */
2102 for (n = 0; n <= max_code; n++) {
2103 curlen = nextlen; nextlen = tree[n+1].Len;
2104 if (++count < max_count && curlen == nextlen) {
2106 } else if (count < min_count) {
2107 s->bl_tree[curlen].Freq += count;
2108 } else if (curlen != 0) {
2109 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2110 s->bl_tree[REP_3_6].Freq++;
2111 } else if (count <= 10) {
2112 s->bl_tree[REPZ_3_10].Freq++;
2114 s->bl_tree[REPZ_11_138].Freq++;
2116 count = 0; prevlen = curlen;
2118 max_count = 138, min_count = 3;
2119 } else if (curlen == nextlen) {
2120 max_count = 6, min_count = 3;
2122 max_count = 7, min_count = 4;
2127 /* ===========================================================================
2128 * Send a literal or distance tree in compressed form, using the codes in
2131 local void send_tree (s, tree, max_code)
2133 ct_data *tree; /* the tree to be scanned */
2134 int max_code; /* and its largest code of non zero frequency */
2136 int n; /* iterates over all tree elements */
2137 int prevlen = -1; /* last emitted length */
2138 int curlen; /* length of current code */
2139 int nextlen = tree[0].Len; /* length of next code */
2140 int count = 0; /* repeat count of the current code */
2141 int max_count = 7; /* max repeat count */
2142 int min_count = 4; /* min repeat count */
2144 /* tree[max_code+1].Len = -1; */ /* guard already set */
2145 if (nextlen == 0) max_count = 138, min_count = 3;
2147 for (n = 0; n <= max_code; n++) {
2148 curlen = nextlen; nextlen = tree[n+1].Len;
2149 if (++count < max_count && curlen == nextlen) {
2151 } else if (count < min_count) {
2152 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2154 } else if (curlen != 0) {
2155 if (curlen != prevlen) {
2156 send_code(s, curlen, s->bl_tree); count--;
2158 Assert(count >= 3 && count <= 6, " 3_6?");
2159 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2161 } else if (count <= 10) {
2162 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2165 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2167 count = 0; prevlen = curlen;
2169 max_count = 138, min_count = 3;
2170 } else if (curlen == nextlen) {
2171 max_count = 6, min_count = 3;
2173 max_count = 7, min_count = 4;
2178 /* ===========================================================================
2179 * Construct the Huffman tree for the bit lengths and return the index in
2180 * bl_order of the last bit length code to send.
2182 local int build_bl_tree(s)
2185 int max_blindex; /* index of last bit length code of non zero freq */
2187 /* Determine the bit length frequencies for literal and distance trees */
2188 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2189 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2191 /* Build the bit length tree: */
2192 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2193 /* opt_len now includes the length of the tree representations, except
2194 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2197 /* Determine the number of bit length codes to send. The pkzip format
2198 * requires that at least 4 bit length codes be sent. (appnote.txt says
2199 * 3 but the actual value used is 4.)
2201 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2202 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2204 /* Update opt_len to include the bit length tree and counts */
2205 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2206 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2207 s->opt_len, s->static_len));
2212 /* ===========================================================================
2213 * Send the header for a block using dynamic Huffman trees: the counts, the
2214 * lengths of the bit length codes, the literal tree and the distance tree.
2215 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2217 local void send_all_trees(s, lcodes, dcodes, blcodes)
2219 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2221 int rank; /* index in bl_order */
2223 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2224 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2226 Tracev((stderr, "\nbl counts: "));
2227 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2228 send_bits(s, dcodes-1, 5);
2229 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2230 for (rank = 0; rank < blcodes; rank++) {
2231 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2232 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2234 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2236 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2237 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2239 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2240 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2243 /* ===========================================================================
2244 * Send a stored block
2246 local void ct_stored_block(s, buf, stored_len, eof)
2248 charf *buf; /* input block */
2249 ulg stored_len; /* length of input block */
2250 int eof; /* true if this is the last block for a file */
2252 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2253 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2254 s->compressed_len += (stored_len + 4) << 3;
2256 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2259 /* Send just the `stored block' type code without any length bytes or data.
2261 local void ct_stored_type_only(s)
2264 send_bits(s, (STORED_BLOCK << 1), 3);
2266 s->compressed_len = (s->compressed_len + 3) & ~7L;
2270 /* ===========================================================================
2271 * Send one empty static block to give enough lookahead for inflate.
2272 * This takes 10 bits, of which 7 may remain in the bit buffer.
2273 * The current inflate code requires 9 bits of lookahead. If the EOB
2274 * code for the previous block was coded on 5 bits or less, inflate
2275 * may have only 5+3 bits of lookahead to decode this EOB.
2276 * (There are no problems if the previous block is stored or fixed.)
2278 local void ct_align(s)
2281 send_bits(s, STATIC_TREES<<1, 3);
2282 send_code(s, END_BLOCK, static_ltree);
2283 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2285 /* Of the 10 bits for the empty block, we have already sent
2286 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2287 * block was thus its length plus what we have just sent.
2289 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2290 send_bits(s, STATIC_TREES<<1, 3);
2291 send_code(s, END_BLOCK, static_ltree);
2292 s->compressed_len += 10L;
2295 s->last_eob_len = 7;
2298 /* ===========================================================================
2299 * Determine the best encoding for the current block: dynamic trees, static
2300 * trees or store, and output the encoded block to the zip file. This function
2301 * returns the total compressed length for the file so far.
2303 local ulg ct_flush_block(s, buf, stored_len, flush)
2305 charf *buf; /* input block, or NULL if too old */
2306 ulg stored_len; /* length of input block */
2307 int flush; /* Z_FINISH if this is the last block for a file */
2309 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2310 int max_blindex; /* index of last bit length code of non zero freq */
2311 int eof = flush == Z_FINISH;
2313 ++s->blocks_in_packet;
2315 /* Check if the file is ascii or binary */
2316 if (s->data_type == UNKNOWN) set_data_type(s);
2318 /* Construct the literal and distance trees */
2319 build_tree(s, (tree_desc *)(&(s->l_desc)));
2320 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2323 build_tree(s, (tree_desc *)(&(s->d_desc)));
2324 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2326 /* At this point, opt_len and static_len are the total bit lengths of
2327 * the compressed block data, excluding the tree representations.
2330 /* Build the bit length tree for the above two trees, and get the index
2331 * in bl_order of the last bit length code to send.
2333 max_blindex = build_bl_tree(s);
2335 /* Determine the best encoding. Compute first the block length in bytes */
2336 opt_lenb = (s->opt_len+3+7)>>3;
2337 static_lenb = (s->static_len+3+7)>>3;
2339 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2340 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2343 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2345 /* If compression failed and this is the first and last block,
2346 * and if the .zip file can be seeked (to rewrite the local header),
2347 * the whole file is transformed into a stored file:
2349 #ifdef STORED_FILE_OK
2350 # ifdef FORCE_STORED_FILE
2351 if (eof && compressed_len == 0L) /* force stored file */
2353 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2356 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2357 if (buf == (charf*)0) error ("block vanished");
2359 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2360 s->compressed_len = stored_len << 3;
2363 #endif /* STORED_FILE_OK */
2365 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
2366 * compression, and this block contains all the data since the last
2367 * time we used Z_PACKET_FLUSH, then just omit this block completely
2370 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
2371 && opt_lenb > stored_len - s->minCompr) {
2372 s->blocks_in_packet = 0;
2373 /* output nothing */
2377 if (buf != (char*)0) /* force stored block */
2379 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2380 /* 4: two words for the lengths */
2383 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2384 * Otherwise we can't have processed more than WSIZE input bytes since
2385 * the last block flush, because compression would have been
2386 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2387 * transform a block into a stored block.
2389 ct_stored_block(s, buf, stored_len, eof);
2393 if (static_lenb >= 0) /* force static trees */
2395 if (static_lenb == opt_lenb)
2398 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2399 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2400 s->compressed_len += 3 + s->static_len;
2402 send_bits(s, (DYN_TREES<<1)+eof, 3);
2403 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2405 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2406 s->compressed_len += 3 + s->opt_len;
2408 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2413 s->compressed_len += 7; /* align on byte boundary */
2415 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2416 s->compressed_len-7*eof));
2418 return s->compressed_len >> 3;
2421 /* ===========================================================================
2422 * Save the match info and tally the frequency counts. Return true if
2423 * the current block must be flushed.
2425 local int ct_tally (s, dist, lc)
2427 int dist; /* distance of matched string */
2428 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2430 s->d_buf[s->last_lit] = (ush)dist;
2431 s->l_buf[s->last_lit++] = (uch)lc;
2433 /* lc is the unmatched char */
2434 s->dyn_ltree[lc].Freq++;
2437 /* Here, lc is the match length - MIN_MATCH */
2438 dist--; /* dist = match distance - 1 */
2439 Assert((ush)dist < (ush)MAX_DIST(s) &&
2440 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2441 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2443 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2444 s->dyn_dtree[d_code(dist)].Freq++;
2447 /* Try to guess if it is profitable to stop the current block here */
2448 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2449 /* Compute an upper bound for the compressed length */
2450 ulg out_length = (ulg)s->last_lit*8L;
2451 ulg in_length = (ulg)s->strstart - s->block_start;
2453 for (dcode = 0; dcode < D_CODES; dcode++) {
2454 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2455 (5L+extra_dbits[dcode]);
2458 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2459 s->last_lit, in_length, out_length,
2460 100L - out_length*100L/in_length));
2461 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2463 return (s->last_lit == s->lit_bufsize-1);
2464 /* We avoid equality with lit_bufsize because of wraparound at 64K
2465 * on 16 bit machines and because stored blocks are restricted to
2470 /* ===========================================================================
2471 * Send the block data compressed using the given Huffman trees
2473 local void compress_block(s, ltree, dtree)
2475 ct_data *ltree; /* literal tree */
2476 ct_data *dtree; /* distance tree */
2478 unsigned dist; /* distance of matched string */
2479 int lc; /* match length or unmatched char (if dist == 0) */
2480 unsigned lx = 0; /* running index in l_buf */
2481 unsigned code; /* the code to send */
2482 int extra; /* number of extra bits to send */
2484 if (s->last_lit != 0) do {
2485 dist = s->d_buf[lx];
2486 lc = s->l_buf[lx++];
2488 send_code(s, lc, ltree); /* send a literal byte */
2489 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2491 /* Here, lc is the match length - MIN_MATCH */
2492 code = length_code[lc];
2493 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2494 extra = extra_lbits[code];
2496 lc -= base_length[code];
2497 send_bits(s, lc, extra); /* send the extra length bits */
2499 dist--; /* dist is now the match distance - 1 */
2500 code = d_code(dist);
2501 Assert (code < D_CODES, "bad d_code");
2503 send_code(s, code, dtree); /* send the distance code */
2504 extra = extra_dbits[code];
2506 dist -= base_dist[code];
2507 send_bits(s, dist, extra); /* send the extra distance bits */
2509 } /* literal or match pair ? */
2511 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2512 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2514 } while (lx < s->last_lit);
2516 send_code(s, END_BLOCK, ltree);
2517 s->last_eob_len = ltree[END_BLOCK].Len;
2520 /* ===========================================================================
2521 * Set the data type to ASCII or Z_BINARY, using a crude approximation:
2522 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2523 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2524 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2526 local void set_data_type(s)
2530 unsigned ascii_freq = 0;
2531 unsigned bin_freq = 0;
2532 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2533 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2534 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2535 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : ASCII);
2538 /* ===========================================================================
2539 * Reverse the first len bits of a code, using straightforward code (a faster
2540 * method would use a table)
2541 * IN assertion: 1 <= len <= 15
2543 local unsigned bi_reverse(code, len)
2544 unsigned code; /* the value to invert */
2545 int len; /* its bit length */
2547 register unsigned res = 0;
2550 code >>= 1, res <<= 1;
2551 } while (--len > 0);
2555 /* ===========================================================================
2556 * Flush the bit buffer, keeping at most 7 bits in it.
2558 local void bi_flush(s)
2561 if (s->bi_valid == 16) {
2562 put_short(s, s->bi_buf);
2565 } else if (s->bi_valid >= 8) {
2566 put_byte(s, (Byte)s->bi_buf);
2572 /* ===========================================================================
2573 * Flush the bit buffer and align the output on a byte boundary
2575 local void bi_windup(s)
2578 if (s->bi_valid > 8) {
2579 put_short(s, s->bi_buf);
2580 } else if (s->bi_valid > 0) {
2581 put_byte(s, (Byte)s->bi_buf);
2586 s->bits_sent = (s->bits_sent+7) & ~7;
2590 /* ===========================================================================
2591 * Copy a stored block, storing first the length and its
2592 * one's complement if requested.
2594 local void copy_block(s, buf, len, header)
2596 charf *buf; /* the input data */
2597 unsigned len; /* its length */
2598 int header; /* true if block header must be written */
2600 bi_windup(s); /* align on byte boundary */
2601 s->last_eob_len = 8; /* enough lookahead for inflate */
2604 put_short(s, (ush)len);
2605 put_short(s, (ush)~len);
2607 s->bits_sent += 2*16;
2611 s->bits_sent += (ulg)len<<3;
2614 put_byte(s, *buf++);
2620 /* infblock.h -- header to use infblock.c
2621 * Copyright (C) 1995 Mark Adler
2622 * For conditions of distribution and use, see copyright notice in zlib.h
2625 /* WARNING: this file should *not* be used by applications. It is
2626 part of the implementation of the compression library and is
2627 subject to change. Applications should only use zlib.h.
2630 struct inflate_blocks_state;
2631 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2633 local inflate_blocks_statef * inflate_blocks_new OF((
2635 check_func c, /* check function */
2636 uInt w)); /* window size */
2638 local int inflate_blocks OF((
2639 inflate_blocks_statef *,
2641 int)); /* initial return code */
2643 local void inflate_blocks_reset OF((
2644 inflate_blocks_statef *,
2646 uLongf *)); /* check value on output */
2648 local int inflate_blocks_free OF((
2649 inflate_blocks_statef *,
2651 uLongf *)); /* check value on output */
2653 local int inflate_addhistory OF((
2654 inflate_blocks_statef *,
2657 local int inflate_packet_flush OF((
2658 inflate_blocks_statef *));
2661 /* inftrees.h -- header to use inftrees.c
2662 * Copyright (C) 1995 Mark Adler
2663 * For conditions of distribution and use, see copyright notice in zlib.h
2666 /* WARNING: this file should *not* be used by applications. It is
2667 part of the implementation of the compression library and is
2668 subject to change. Applications should only use zlib.h.
2671 /* Huffman code lookup table entry--this entry is four bytes for machines
2672 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2674 typedef struct inflate_huft_s FAR inflate_huft;
2676 struct inflate_huft_s {
2679 Byte Exop; /* number of extra bits or operation */
2680 Byte Bits; /* number of bits in this code or subcode */
2682 uInt Nalloc; /* number of these allocated here */
2683 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2684 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2686 uInt Base; /* literal, length base, or distance base */
2687 inflate_huft *Next; /* pointer to next level of table */
2692 local uInt inflate_hufts;
2695 local int inflate_trees_bits OF((
2696 uIntf *, /* 19 code lengths */
2697 uIntf *, /* bits tree desired/actual depth */
2698 inflate_huft * FAR *, /* bits tree result */
2699 z_stream *)); /* for zalloc, zfree functions */
2701 local int inflate_trees_dynamic OF((
2702 uInt, /* number of literal/length codes */
2703 uInt, /* number of distance codes */
2704 uIntf *, /* that many (total) code lengths */
2705 uIntf *, /* literal desired/actual bit depth */
2706 uIntf *, /* distance desired/actual bit depth */
2707 inflate_huft * FAR *, /* literal/length tree result */
2708 inflate_huft * FAR *, /* distance tree result */
2709 z_stream *)); /* for zalloc, zfree functions */
2711 local int inflate_trees_fixed OF((
2712 uIntf *, /* literal desired/actual bit depth */
2713 uIntf *, /* distance desired/actual bit depth */
2714 inflate_huft * FAR *, /* literal/length tree result */
2715 inflate_huft * FAR *)); /* distance tree result */
2717 local int inflate_trees_free OF((
2718 inflate_huft *, /* tables to free */
2719 z_stream *)); /* for zfree function */
2723 /* infcodes.h -- header to use infcodes.c
2724 * Copyright (C) 1995 Mark Adler
2725 * For conditions of distribution and use, see copyright notice in zlib.h
2728 /* WARNING: this file should *not* be used by applications. It is
2729 part of the implementation of the compression library and is
2730 subject to change. Applications should only use zlib.h.
2733 struct inflate_codes_state;
2734 typedef struct inflate_codes_state FAR inflate_codes_statef;
2736 local inflate_codes_statef *inflate_codes_new OF((
2738 inflate_huft *, inflate_huft *,
2741 local int inflate_codes OF((
2742 inflate_blocks_statef *,
2746 local void inflate_codes_free OF((
2747 inflate_codes_statef *,
2752 /* inflate.c -- zlib interface to inflate modules
2753 * Copyright (C) 1995 Mark Adler
2754 * For conditions of distribution and use, see copyright notice in zlib.h
2757 /* inflate private state */
2758 struct internal_state {
2762 METHOD, /* waiting for method byte */
2763 FLAG, /* waiting for flag byte */
2764 BLOCKS, /* decompressing blocks */
2765 CHECK4, /* four check bytes to go */
2766 CHECK3, /* three check bytes to go */
2767 CHECK2, /* two check bytes to go */
2768 CHECK1, /* one check byte to go */
2769 DONE, /* finished check, done */
2770 BAD} /* got an error--stay here */
2771 mode; /* current inflate mode */
2773 /* mode dependent information */
2775 uInt method; /* if FLAGS, method byte */
2777 uLong was; /* computed check value */
2778 uLong need; /* stream check value */
2779 } check; /* if CHECK, check values to compare */
2780 uInt marker; /* if BAD, inflateSync's marker bytes count */
2781 } sub; /* submode */
2783 /* mode independent information */
2784 int nowrap; /* flag for no wrapper */
2785 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2786 inflate_blocks_statef
2787 *blocks; /* current inflate_blocks state */
2797 if (z == Z_NULL || z->state == Z_NULL)
2798 return Z_STREAM_ERROR;
2799 z->total_in = z->total_out = 0;
2801 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2802 inflate_blocks_reset(z->state->blocks, z, &c);
2803 Trace((stderr, "inflate: reset\n"));
2813 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2814 return Z_STREAM_ERROR;
2815 if (z->state->blocks != Z_NULL)
2816 inflate_blocks_free(z->state->blocks, z, &c);
2817 ZFREE(z, z->state, sizeof(struct internal_state));
2819 Trace((stderr, "inflate: end\n"));
2824 int inflateInit2(z, w)
2828 /* initialize state */
2830 return Z_STREAM_ERROR;
2831 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2832 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2833 if ((z->state = (struct internal_state FAR *)
2834 ZALLOC_INIT(z,1,sizeof(struct internal_state))) == Z_NULL)
2836 z->state->blocks = Z_NULL;
2838 /* handle undocumented nowrap option (no zlib header or check) */
2839 z->state->nowrap = 0;
2843 z->state->nowrap = 1;
2846 /* set window size */
2847 if (w < 8 || w > 15)
2850 return Z_STREAM_ERROR;
2852 z->state->wbits = (uInt)w;
2854 /* create inflate_blocks state */
2855 if ((z->state->blocks =
2856 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2862 Trace((stderr, "inflate: allocated\n"));
2873 return inflateInit2(z, DEF_WBITS);
2877 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2878 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2887 if (z == Z_NULL || z->next_in == Z_NULL)
2888 return Z_STREAM_ERROR;
2890 while (1) switch (z->state->mode)
2894 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2896 z->state->mode = BAD;
2897 z->msg = "unknown compression method";
2898 z->state->sub.marker = 5; /* can't try inflateSync */
2901 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2903 z->state->mode = BAD;
2904 z->msg = "invalid window size";
2905 z->state->sub.marker = 5; /* can't try inflateSync */
2908 z->state->mode = FLAG;
2911 if ((b = NEXTBYTE) & 0x20)
2913 z->state->mode = BAD;
2914 z->msg = "invalid reserved bit";
2915 z->state->sub.marker = 5; /* can't try inflateSync */
2918 if (((z->state->sub.method << 8) + b) % 31)
2920 z->state->mode = BAD;
2921 z->msg = "incorrect header check";
2922 z->state->sub.marker = 5; /* can't try inflateSync */
2925 Trace((stderr, "inflate: zlib header ok\n"));
2926 z->state->mode = BLOCKS;
2928 r = inflate_blocks(z->state->blocks, z, r);
2929 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2930 r = inflate_packet_flush(z->state->blocks);
2931 if (r == Z_DATA_ERROR)
2933 z->state->mode = BAD;
2934 z->state->sub.marker = 0; /* can try inflateSync */
2937 if (r != Z_STREAM_END)
2940 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2941 if (z->state->nowrap)
2943 z->state->mode = DONE;
2946 z->state->mode = CHECK4;
2949 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2950 z->state->mode = CHECK3;
2953 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2954 z->state->mode = CHECK2;
2957 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2958 z->state->mode = CHECK1;
2961 z->state->sub.check.need += (uLong)NEXTBYTE;
2963 if (z->state->sub.check.was != z->state->sub.check.need)
2965 z->state->mode = BAD;
2966 z->msg = "incorrect data check";
2967 z->state->sub.marker = 5; /* can't try inflateSync */
2970 Trace((stderr, "inflate: zlib check ok\n"));
2971 z->state->mode = DONE;
2973 return Z_STREAM_END;
2975 return Z_DATA_ERROR;
2977 return Z_STREAM_ERROR;
2981 if (f != Z_PACKET_FLUSH)
2983 z->state->mode = BAD;
2984 z->state->sub.marker = 0; /* can try inflateSync */
2985 return Z_DATA_ERROR;
2989 * This subroutine adds the data at next_in/avail_in to the output history
2990 * without performing any output. The output buffer must be "caught up";
2991 * i.e. no pending output (hence s->read equals s->write), and the state must
2992 * be BLOCKS (i.e. we should be willing to see the start of a series of
2993 * BLOCKS). On exit, the output will also be caught up, and the checksum
2994 * will have been updated if need be.
2997 int inflateIncomp(z)
3000 if (z->state->mode != BLOCKS)
3001 return Z_DATA_ERROR;
3002 return inflate_addhistory(z->state->blocks, z);
3009 uInt n; /* number of bytes to look at */
3010 Bytef *p; /* pointer to bytes */
3011 uInt m; /* number of marker bytes found in a row */
3012 uLong r, w; /* temporaries to save total_in and total_out */
3015 if (z == Z_NULL || z->state == Z_NULL)
3016 return Z_STREAM_ERROR;
3017 if (z->state->mode != BAD)
3019 z->state->mode = BAD;
3020 z->state->sub.marker = 0;
3022 if ((n = z->avail_in) == 0)
3025 m = z->state->sub.marker;
3030 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3040 z->total_in += p - z->next_in;
3043 z->state->sub.marker = m;
3045 /* return no joy or set up to restart on a new block */
3047 return Z_DATA_ERROR;
3048 r = z->total_in; w = z->total_out;
3050 z->total_in = r; z->total_out = w;
3051 z->state->mode = BLOCKS;
3059 /* infutil.h -- types and macros common to blocks and codes
3060 * Copyright (C) 1995 Mark Adler
3061 * For conditions of distribution and use, see copyright notice in zlib.h
3064 /* WARNING: this file should *not* be used by applications. It is
3065 part of the implementation of the compression library and is
3066 subject to change. Applications should only use zlib.h.
3069 /* inflate blocks semi-private state */
3070 struct inflate_blocks_state {
3074 TYPE, /* get type bits (3, including end bit) */
3075 LENS, /* get lengths for stored */
3076 STORED, /* processing stored block */
3077 TABLE, /* get table lengths */
3078 BTREE, /* get bit lengths tree for a dynamic block */
3079 DTREE, /* get length, distance trees for a dynamic block */
3080 CODES, /* processing fixed or dynamic block */
3081 DRY, /* output remaining window bytes */
3082 DONEB, /* finished last block, done */
3083 BADB} /* got a data error--stuck here */
3084 mode; /* current inflate_block mode */
3086 /* mode dependent information */
3088 uInt left; /* if STORED, bytes left to copy */
3090 uInt table; /* table lengths (14 bits) */
3091 uInt index; /* index into blens (or border) */
3092 uIntf *blens; /* bit lengths of codes */
3093 uInt bb; /* bit length tree depth */
3094 inflate_huft *tb; /* bit length decoding tree */
3095 int nblens; /* # elements allocated at blens */
3096 } trees; /* if DTREE, decoding info for trees */
3098 inflate_huft *tl, *td; /* trees to free */
3099 inflate_codes_statef
3101 } decode; /* if CODES, current state */
3102 } sub; /* submode */
3103 uInt last; /* true if this block is the last block */
3105 /* mode independent information */
3106 uInt bitk; /* bits in bit buffer */
3107 uLong bitb; /* bit buffer */
3108 Bytef *window; /* sliding window */
3109 Bytef *end; /* one byte after sliding window */
3110 Bytef *read; /* window read pointer */
3111 Bytef *write; /* window write pointer */
3112 check_func checkfn; /* check function */
3113 uLong check; /* check on output */
3118 /* defines for inflate input/output */
3119 /* update pointers and return */
3120 #define UPDBITS {s->bitb=b;s->bitk=k;}
3121 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3122 #define UPDOUT {s->write=q;}
3123 #define UPDATE {UPDBITS UPDIN UPDOUT}
3124 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3125 /* get bytes and bits */
3126 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3127 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3128 #define NEXTBYTE (n--,*p++)
3129 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3130 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3132 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3133 #define LOADOUT {q=s->write;m=WAVAIL;}
3134 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3135 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3136 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3137 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3138 /* load local pointers */
3139 #define LOAD {LOADIN LOADOUT}
3141 /* And'ing with mask[n] masks the lower n bits */
3142 local uInt inflate_mask[] = {
3144 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3145 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3148 /* copy as much as possible from the sliding window to the output area */
3149 local int inflate_flush OF((
3150 inflate_blocks_statef *,
3155 /* inffast.h -- header to use inffast.c
3156 * Copyright (C) 1995 Mark Adler
3157 * For conditions of distribution and use, see copyright notice in zlib.h
3160 /* WARNING: this file should *not* be used by applications. It is
3161 part of the implementation of the compression library and is
3162 subject to change. Applications should only use zlib.h.
3165 local int inflate_fast OF((
3170 inflate_blocks_statef *,
3175 /* infblock.c -- interpret and process block types to last block
3176 * Copyright (C) 1995 Mark Adler
3177 * For conditions of distribution and use, see copyright notice in zlib.h
3180 /* Table for deflate from PKZIP's appnote.txt. */
3181 local uInt border[] = { /* Order of the bit length code lengths */
3182 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3185 Notes beyond the 1.93a appnote.txt:
3187 1. Distance pointers never point before the beginning of the output
3189 2. Distance pointers can point back across blocks, up to 32k away.
3190 3. There is an implied maximum of 7 bits for the bit length table and
3191 15 bits for the actual data.
3192 4. If only one code exists, then it is encoded using one bit. (Zero
3193 would be more efficient, but perhaps a little confusing.) If two
3194 codes exist, they are coded using one bit each (0 and 1).
3195 5. There is no way of sending zero distance codes--a dummy must be
3196 sent if there are none. (History: a pre 2.0 version of PKZIP would
3197 store blocks with no distance codes, but this was discovered to be
3198 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3199 zero distance codes, which is sent as one code of zero bits in
3201 6. There are up to 286 literal/length codes. Code 256 represents the
3202 end-of-block. Note however that the static length tree defines
3203 288 codes just to fill out the Huffman codes. Codes 286 and 287
3204 cannot be used though, since there is no length base or extra bits
3205 defined for them. Similarily, there are up to 30 distance codes.
3206 However, static trees define 32 codes (all 5 bits) to fill out the
3207 Huffman codes, but the last two had better not show up in the data.
3208 7. Unzip can check dynamic Huffman blocks for complete code sets.
3209 The exception is that a single code would not be complete (see #4).
3210 8. The five bits following the block type is really the number of
3211 literal codes sent minus 257.
3212 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3213 (1+6+6). Therefore, to output three times the length, you output
3214 three codes (1+1+1), whereas to output four times the same length,
3215 you only need two codes (1+3). Hmm.
3216 10. In the tree reconstruction algorithm, Code = Code + Increment
3217 only if BitLength(i) is not zero. (Pretty obvious.)
3218 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3219 12. Note: length code 284 can represent 227-258, but length code 285
3220 really is 258. The last length deserves its own, short code
3221 since it gets used a lot in very redundant files. The length
3222 258 is special since 258 - 3 (the min match length) is 255.
3223 13. The literal/length and distance code bit lengths are read as a
3224 single stream of lengths. It is possible (and advantageous) for
3225 a repeat code (16, 17, or 18) to go across the boundary between
3226 the two sets of lengths.
3230 local void inflate_blocks_reset(s, z, c)
3231 inflate_blocks_statef *s;
3235 if (s->checkfn != Z_NULL)
3237 if (s->mode == BTREE || s->mode == DTREE)
3238 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3239 if (s->mode == CODES)
3241 inflate_codes_free(s->sub.decode.codes, z);
3242 inflate_trees_free(s->sub.decode.td, z);
3243 inflate_trees_free(s->sub.decode.tl, z);
3248 s->read = s->write = s->window;
3249 if (s->checkfn != Z_NULL)
3250 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3251 Trace((stderr, "inflate: blocks reset\n"));
3255 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
3260 inflate_blocks_statef *s;
3262 if ((s = (inflate_blocks_statef *)ZALLOC_INIT
3263 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3265 if ((s->window = (Bytef *)ZALLOC_INIT(z, 1, w)) == Z_NULL)
3267 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3270 s->end = s->window + w;
3273 Trace((stderr, "inflate: blocks allocated\n"));
3274 inflate_blocks_reset(s, z, &s->check);
3279 local int inflate_blocks(s, z, r)
3280 inflate_blocks_statef *s;
3284 uInt t; /* temporary storage */
3285 uLong b; /* bit buffer */
3286 uInt k; /* bits in bit buffer */
3287 Bytef *p; /* input data pointer */
3288 uInt n; /* bytes available there */
3289 Bytef *q; /* output window write pointer */
3290 uInt m; /* bytes to end of window or read pointer */
3292 /* copy input/output information to locals (UPDATE macro restores) */
3295 /* process input based on current state */
3296 while (1) switch (s->mode)
3304 case 0: /* stored */
3305 Trace((stderr, "inflate: stored block%s\n",
3306 s->last ? " (last)" : ""));
3308 t = k & 7; /* go to byte boundary */
3310 s->mode = LENS; /* get length of stored block */
3313 Trace((stderr, "inflate: fixed codes block%s\n",
3314 s->last ? " (last)" : ""));
3317 inflate_huft *tl, *td;
3319 inflate_trees_fixed(&bl, &bd, &tl, &td);
3320 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3321 if (s->sub.decode.codes == Z_NULL)
3326 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3327 s->sub.decode.td = Z_NULL;
3332 case 2: /* dynamic */
3333 Trace((stderr, "inflate: dynamic codes block%s\n",
3334 s->last ? " (last)" : ""));
3338 case 3: /* illegal */
3341 z->msg = "invalid block type";
3348 if (((~b) >> 16) != (b & 0xffff))
3351 z->msg = "invalid stored block lengths";
3355 s->sub.left = (uInt)b & 0xffff;
3356 b = k = 0; /* dump bits */
3357 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3358 s->mode = s->sub.left ? STORED : TYPE;
3370 if ((s->sub.left -= t) != 0)
3372 Tracev((stderr, "inflate: stored end, %lu total out\n",
3373 z->total_out + (q >= s->read ? q - s->read :
3374 (s->end - s->read) + (q - s->window))));
3375 s->mode = s->last ? DRY : TYPE;
3379 s->sub.trees.table = t = (uInt)b & 0x3fff;
3380 #ifndef PKZIP_BUG_WORKAROUND
3381 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3384 z->msg = "too many length or distance symbols";
3389 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3392 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3397 s->sub.trees.nblens = t;
3399 s->sub.trees.index = 0;
3400 Tracev((stderr, "inflate: table sizes ok\n"));
3403 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3406 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3409 while (s->sub.trees.index < 19)
3410 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3411 s->sub.trees.bb = 7;
3412 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3413 &s->sub.trees.tb, z);
3417 if (r == Z_DATA_ERROR)
3421 s->sub.trees.index = 0;
3422 Tracev((stderr, "inflate: bits tree ok\n"));
3425 while (t = s->sub.trees.table,
3426 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3431 t = s->sub.trees.bb;
3433 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3434 t = h->word.what.Bits;
3439 s->sub.trees.blens[s->sub.trees.index++] = c;
3441 else /* c == 16..18 */
3443 i = c == 18 ? 7 : c - 14;
3444 j = c == 18 ? 11 : 3;
3447 j += (uInt)b & inflate_mask[i];
3449 i = s->sub.trees.index;
3450 t = s->sub.trees.table;
3451 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3455 z->msg = "invalid bit length repeat";
3459 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3461 s->sub.trees.blens[i++] = c;
3463 s->sub.trees.index = i;
3466 inflate_trees_free(s->sub.trees.tb, z);
3467 s->sub.trees.tb = Z_NULL;
3470 inflate_huft *tl, *td;
3471 inflate_codes_statef *c;
3473 bl = 9; /* must be <= 9 for lookahead assumptions */
3474 bd = 6; /* must be <= 9 for lookahead assumptions */
3475 t = s->sub.trees.table;
3476 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3477 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3480 if (t == (uInt)Z_DATA_ERROR)
3485 Tracev((stderr, "inflate: trees ok\n"));
3486 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3488 inflate_trees_free(td, z);
3489 inflate_trees_free(tl, z);
3493 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3494 s->sub.decode.codes = c;
3495 s->sub.decode.tl = tl;
3496 s->sub.decode.td = td;
3501 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3502 return inflate_flush(s, z, r);
3504 inflate_codes_free(s->sub.decode.codes, z);
3505 inflate_trees_free(s->sub.decode.td, z);
3506 inflate_trees_free(s->sub.decode.tl, z);
3508 Tracev((stderr, "inflate: codes end, %lu total out\n",
3509 z->total_out + (q >= s->read ? q - s->read :
3510 (s->end - s->read) + (q - s->window))));
3516 if (k > 7) /* return unused byte, if any */
3518 Assert(k < 16, "inflate_codes grabbed too many bytes")
3521 p--; /* can always return one */
3526 if (s->read != s->write)
3542 local int inflate_blocks_free(s, z, c)
3543 inflate_blocks_statef *s;
3547 inflate_blocks_reset(s, z, c);
3548 ZFREE(z, s->window, s->end - s->window);
3549 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3550 Trace((stderr, "inflate: blocks freed\n"));
3555 * This subroutine adds the data at next_in/avail_in to the output history
3556 * without performing any output. The output buffer must be "caught up";
3557 * i.e. no pending output (hence s->read equals s->write), and the state must
3558 * be BLOCKS (i.e. we should be willing to see the start of a series of
3559 * BLOCKS). On exit, the output will also be caught up, and the checksum
3560 * will have been updated if need be.
3562 local int inflate_addhistory(s, z)
3563 inflate_blocks_statef *s;
3566 uLong b; /* bit buffer */ /* NOT USED HERE */
3567 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3568 uInt t; /* temporary storage */
3569 Bytef *p; /* input data pointer */
3570 uInt n; /* bytes available there */
3571 Bytef *q; /* output window write pointer */
3572 uInt m; /* bytes to end of window or read pointer */
3574 if (s->read != s->write)
3575 return Z_STREAM_ERROR;
3576 if (s->mode != TYPE)
3577 return Z_DATA_ERROR;
3579 /* we're ready to rock */
3581 /* while there is input ready, copy to output buffer, moving
3582 * pointers as needed.
3585 t = n; /* how many to do */
3586 /* is there room until end of buffer? */
3588 /* update check information */
3589 if (s->checkfn != Z_NULL)
3590 s->check = (*s->checkfn)(s->check, q, t);
3596 s->read = q; /* drag read pointer forward */
3597 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
3599 s->read = q = s->window;
3609 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3610 * a `stored' block type value but not the (zero) length bytes.
3612 local int inflate_packet_flush(s)
3613 inflate_blocks_statef *s;
3615 if (s->mode != LENS)
3616 return Z_DATA_ERROR;
3623 /* inftrees.c -- generate Huffman trees for efficient decoding
3624 * Copyright (C) 1995 Mark Adler
3625 * For conditions of distribution and use, see copyright notice in zlib.h
3628 /* simplify the use of the inflate_huft type with some defines */
3629 #define base more.Base
3630 #define next more.Next
3631 #define exop word.what.Exop
3632 #define bits word.what.Bits
3635 local int huft_build OF((
3636 uIntf *, /* code lengths in bits */
3637 uInt, /* number of codes */
3638 uInt, /* number of "simple" codes */
3639 uIntf *, /* list of base values for non-simple codes */
3640 uIntf *, /* list of extra bits for non-simple codes */
3641 inflate_huft * FAR*,/* result: starting table */
3642 uIntf *, /* maximum lookup bits (returns actual) */
3643 z_stream *)); /* for zalloc function */
3645 local voidpf falloc OF((
3646 voidpf, /* opaque pointer (not used) */
3647 uInt, /* number of items */
3648 uInt)); /* size of item */
3650 local void ffree OF((
3651 voidpf q, /* opaque pointer (not used) */
3652 voidpf p, /* what to free (not used) */
3653 uInt n)); /* number of bytes (not used) */
3655 /* Tables for deflate from PKZIP's appnote.txt. */
3656 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3657 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3658 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3659 /* actually lengths - 2; also see note #13 above about 258 */
3660 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3661 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3662 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3663 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3664 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3665 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3666 8193, 12289, 16385, 24577};
3667 local uInt cpdext[] = { /* Extra bits for distance codes */
3668 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3669 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3673 Huffman code decoding is performed using a multi-level table lookup.
3674 The fastest way to decode is to simply build a lookup table whose
3675 size is determined by the longest code. However, the time it takes
3676 to build this table can also be a factor if the data being decoded
3677 is not very long. The most common codes are necessarily the
3678 shortest codes, so those codes dominate the decoding time, and hence
3679 the speed. The idea is you can have a shorter table that decodes the
3680 shorter, more probable codes, and then point to subsidiary tables for
3681 the longer codes. The time it costs to decode the longer codes is
3682 then traded against the time it takes to make longer tables.
3684 This results of this trade are in the variables lbits and dbits
3685 below. lbits is the number of bits the first level table for literal/
3686 length codes can decode in one step, and dbits is the same thing for
3687 the distance codes. Subsequent tables are also less than or equal to
3688 those sizes. These values may be adjusted either when all of the
3689 codes are shorter than that, in which case the longest code length in
3690 bits is used, or when the shortest code is *longer* than the requested
3691 table size, in which case the length of the shortest code in bits is
3694 There are two different values for the two tables, since they code a
3695 different number of possibilities each. The literal/length table
3696 codes 286 possible values, or in a flat code, a little over eight
3697 bits. The distance table codes 30 possible values, or a little less
3698 than five bits, flat. The optimum values for speed end up being
3699 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3700 The optimum values may differ though from machine to machine, and
3701 possibly even between compilers. Your mileage may vary.
3705 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3706 #define BMAX 15 /* maximum bit length of any code */
3707 #define N_MAX 288 /* maximum number of codes in any set */
3713 local int huft_build(b, n, s, d, e, t, m, zs)
3714 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3715 uInt n; /* number of codes (assumed <= N_MAX) */
3716 uInt s; /* number of simple-valued codes (0..s-1) */
3717 uIntf *d; /* list of base values for non-simple codes */
3718 uIntf *e; /* list of extra bits for non-simple codes */
3719 inflate_huft * FAR *t; /* result: starting table */
3720 uIntf *m; /* maximum lookup bits, returns actual */
3721 z_stream *zs; /* for zalloc function */
3722 /* Given a list of code lengths and a maximum table size, make a set of
3723 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3724 if the given code set is incomplete (the tables are still built in this
3725 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3726 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3729 uInt a; /* counter for codes of length k */
3730 uInt c[BMAX+1]; /* bit length count table */
3731 uInt f; /* i repeats in table every f entries */
3732 int g; /* maximum code length */
3733 int h; /* table level */
3734 register uInt i; /* counter, current code */
3735 register uInt j; /* counter */
3736 register int k; /* number of bits in current code */
3737 int l; /* bits per table (returned in m) */
3738 register uIntf *p; /* pointer into c[], b[], or v[] */
3739 inflate_huft *q; /* points to current table */
3740 struct inflate_huft_s r; /* table entry for structure assignment */
3741 inflate_huft *u[BMAX]; /* table stack */
3742 uInt v[N_MAX]; /* values in order of bit length */
3743 register int w; /* bits before this table == (l * h) */
3744 uInt x[BMAX+1]; /* bit offsets, then code stack */
3745 uIntf *xp; /* pointer into x */
3746 int y; /* number of dummy codes added */
3747 uInt z; /* number of entries in current table */
3750 /* Generate counts for each bit length */
3752 #define C0 *p++ = 0;
3753 #define C2 C0 C0 C0 C0
3754 #define C4 C2 C2 C2 C2
3755 C4 /* clear c[]--assume BMAX+1 is 16 */
3758 c[*p++]++; /* assume all entries <= BMAX */
3760 if (c[0] == n) /* null input--all zero length codes */
3762 *t = (inflate_huft *)Z_NULL;
3768 /* Find minimum and maximum length, bound *m by those */
3770 for (j = 1; j <= BMAX; j++)
3773 k = j; /* minimum code length */
3776 for (i = BMAX; i; i--)
3779 g = i; /* maximum code length */
3785 /* Adjust last length count to fill out codes, if needed */
3786 for (y = 1 << j; j < i; j++, y <<= 1)
3787 if ((y -= c[j]) < 0)
3788 return Z_DATA_ERROR;
3789 if ((y -= c[i]) < 0)
3790 return Z_DATA_ERROR;
3794 /* Generate starting offsets into the value table for each length */
3796 p = c + 1; xp = x + 2;
3797 while (--i) { /* note that i == g from above */
3798 *xp++ = (j += *p++);
3802 /* Make a table of values in order of bit lengths */
3805 if ((j = *p++) != 0)
3810 /* Generate the Huffman codes and for each, make the table entries */
3811 x[0] = i = 0; /* first Huffman code is zero */
3812 p = v; /* grab values in bit order */
3813 h = -1; /* no tables yet--level -1 */
3814 w = -l; /* bits decoded == (l * h) */
3815 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3816 q = (inflate_huft *)Z_NULL; /* ditto */
3819 /* go through the bit lengths (k already is bits in shortest code) */
3825 /* here i is the Huffman code of length k bits for value *p */
3826 /* make tables up to required level */
3830 w += l; /* previous table always l bits */
3832 /* compute minimum size table less than or equal to l bits */
3833 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3834 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3835 { /* too few codes for k-w bit table */
3836 f -= a + 1; /* deduct codes from patterns left */
3839 while (++j < z) /* try smaller tables up to z bits */
3841 if ((f <<= 1) <= *++xp)
3842 break; /* enough codes to use up j bits */
3843 f -= *xp; /* else deduct codes from patterns */
3846 z = 1 << j; /* table entries for j-bit table */
3848 /* allocate and link in new table */
3849 if ((q = (inflate_huft *)ZALLOC
3850 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3853 inflate_trees_free(u[0], zs);
3854 return Z_MEM_ERROR; /* not enough memory */
3856 q->word.Nalloc = z + 1;
3858 inflate_hufts += z + 1;
3860 *t = q + 1; /* link to list for huft_free() */
3861 *(t = &(q->next)) = Z_NULL;
3862 u[h] = ++q; /* table starts after link */
3864 /* connect to last table, if there is one */
3867 x[h] = i; /* save pattern for backing up */
3868 r.bits = (Byte)l; /* bits to dump before this table */
3869 r.exop = (Byte)j; /* bits in this table */
3870 r.next = q; /* pointer to this table */
3871 j = i >> (w - l); /* (get around Turbo C bug) */
3872 u[h-1][j] = r; /* connect to last table */
3876 /* set up table entry in r */
3877 r.bits = (Byte)(k - w);
3879 r.exop = 128 + 64; /* out of values--invalid code */
3882 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3883 r.base = *p++; /* simple code is just the value */
3887 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3888 r.base = d[*p++ - s];
3891 /* fill code-like entries with r */
3893 for (j = i >> w; j < z; j += f)
3896 /* backwards increment the k-bit code i */
3897 for (j = 1 << (k - 1); i & j; j >>= 1)
3901 /* backup over finished tables */
3902 while ((i & ((1 << w) - 1)) != x[h])
3904 h--; /* don't need to update q */
3911 /* Return Z_BUF_ERROR if we were given an incomplete table */
3912 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3916 local int inflate_trees_bits(c, bb, tb, z)
3917 uIntf *c; /* 19 code lengths */
3918 uIntf *bb; /* bits tree desired/actual depth */
3919 inflate_huft * FAR *tb; /* bits tree result */
3920 z_stream *z; /* for zfree function */
3924 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3925 if (r == Z_DATA_ERROR)
3926 z->msg = "oversubscribed dynamic bit lengths tree";
3927 else if (r == Z_BUF_ERROR)
3929 inflate_trees_free(*tb, z);
3930 z->msg = "incomplete dynamic bit lengths tree";
3937 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3938 uInt nl; /* number of literal/length codes */
3939 uInt nd; /* number of distance codes */
3940 uIntf *c; /* that many (total) code lengths */
3941 uIntf *bl; /* literal desired/actual bit depth */
3942 uIntf *bd; /* distance desired/actual bit depth */
3943 inflate_huft * FAR *tl; /* literal/length tree result */
3944 inflate_huft * FAR *td; /* distance tree result */
3945 z_stream *z; /* for zfree function */
3949 /* build literal/length tree */
3950 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3952 if (r == Z_DATA_ERROR)
3953 z->msg = "oversubscribed literal/length tree";
3954 else if (r == Z_BUF_ERROR)
3956 inflate_trees_free(*tl, z);
3957 z->msg = "incomplete literal/length tree";
3963 /* build distance tree */
3964 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3966 if (r == Z_DATA_ERROR)
3967 z->msg = "oversubscribed literal/length tree";
3968 else if (r == Z_BUF_ERROR) {
3969 #ifdef PKZIP_BUG_WORKAROUND
3973 inflate_trees_free(*td, z);
3974 z->msg = "incomplete literal/length tree";
3977 inflate_trees_free(*tl, z);
3987 /* build fixed tables only once--keep them here */
3988 local int fixed_lock = 0;
3989 local int fixed_built = 0;
3990 #define FIXEDH 530 /* number of hufts used by fixed tables */
3991 local uInt fixed_left = FIXEDH;
3992 local inflate_huft fixed_mem[FIXEDH];
3993 local uInt fixed_bl;
3994 local uInt fixed_bd;
3995 local inflate_huft *fixed_tl;
3996 local inflate_huft *fixed_td;
3999 local voidpf falloc(q, n, s)
4000 voidpf q; /* opaque pointer (not used) */
4001 uInt n; /* number of items */
4002 uInt s; /* size of item */
4004 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
4005 "inflate_trees falloc overflow");
4006 if (q) s++; /* to make some compilers happy */
4008 return (voidpf)(fixed_mem + fixed_left);
4012 local void ffree(q, p, n)
4017 Assert(0, "inflate_trees ffree called!");
4018 if (q) q = p; /* to make some compilers happy */
4022 local int inflate_trees_fixed(bl, bd, tl, td)
4023 uIntf *bl; /* literal desired/actual bit depth */
4024 uIntf *bd; /* distance desired/actual bit depth */
4025 inflate_huft * FAR *tl; /* literal/length tree result */
4026 inflate_huft * FAR *td; /* distance tree result */
4028 /* build fixed tables if not built already--lock out other instances */
4029 while (++fixed_lock > 1)
4033 int k; /* temporary variable */
4034 unsigned c[288]; /* length list for huft_build */
4035 z_stream z; /* for falloc function */
4037 /* set up fake z_stream for memory routines */
4043 for (k = 0; k < 144; k++)
4045 for (; k < 256; k++)
4047 for (; k < 280; k++)
4049 for (; k < 288; k++)
4052 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4054 /* distance table */
4055 for (k = 0; k < 30; k++)
4058 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4072 local int inflate_trees_free(t, z)
4073 inflate_huft *t; /* table to free */
4074 z_stream *z; /* for zfree function */
4075 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4076 list of the tables it made, with the links in a dummy first entry of
4079 register inflate_huft *p, *q;
4081 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4086 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4093 /* infcodes.c -- process literals and length/distance pairs
4094 * Copyright (C) 1995 Mark Adler
4095 * For conditions of distribution and use, see copyright notice in zlib.h
4098 /* simplify the use of the inflate_huft type with some defines */
4099 #define base more.Base
4100 #define next more.Next
4101 #define exop word.what.Exop
4102 #define bits word.what.Bits
4104 /* inflate codes private state */
4105 struct inflate_codes_state {
4108 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4109 START, /* x: set up for LEN */
4110 LEN, /* i: get length/literal/eob next */
4111 LENEXT, /* i: getting length extra (have base) */
4112 DIST, /* i: get distance next */
4113 DISTEXT, /* i: getting distance extra */
4114 COPY, /* o: copying bytes in window, waiting for space */
4115 LIT, /* o: got literal, waiting for output space */
4116 WASH, /* o: got eob, possibly still output waiting */
4117 END, /* x: got eob and all data flushed */
4118 BADCODE} /* x: got error */
4119 mode; /* current inflate_codes mode */
4121 /* mode dependent information */
4125 inflate_huft *tree; /* pointer into tree */
4126 uInt need; /* bits needed */
4127 } code; /* if LEN or DIST, where in tree */
4128 uInt lit; /* if LIT, literal */
4130 uInt get; /* bits to get for extra */
4131 uInt dist; /* distance back to copy from */
4132 } copy; /* if EXT or COPY, where and how much */
4133 } sub; /* submode */
4135 /* mode independent information */
4136 Byte lbits; /* ltree bits decoded per branch */
4137 Byte dbits; /* dtree bits decoder per branch */
4138 inflate_huft *ltree; /* literal/length/eob tree */
4139 inflate_huft *dtree; /* distance tree */
4144 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4146 inflate_huft *tl, *td;
4149 inflate_codes_statef *c;
4151 if ((c = (inflate_codes_statef *)
4152 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4155 c->lbits = (Byte)bl;
4156 c->dbits = (Byte)bd;
4159 Tracev((stderr, "inflate: codes new\n"));
4165 local int inflate_codes(s, z, r)
4166 inflate_blocks_statef *s;
4170 uInt j; /* temporary storage */
4171 inflate_huft *t; /* temporary pointer */
4172 uInt e; /* extra bits or operation */
4173 uLong b; /* bit buffer */
4174 uInt k; /* bits in bit buffer */
4175 Bytef *p; /* input data pointer */
4176 uInt n; /* bytes available there */
4177 Bytef *q; /* output window write pointer */
4178 uInt m; /* bytes to end of window or read pointer */
4179 Bytef *f; /* pointer to copy strings from */
4180 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4182 /* copy input/output information to locals (UPDATE macro restores) */
4185 /* process input and output based on current state */
4186 while (1) switch (c->mode)
4187 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4188 case START: /* x: set up for LEN */
4190 if (m >= 258 && n >= 10)
4193 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4197 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4202 c->sub.code.need = c->lbits;
4203 c->sub.code.tree = c->ltree;
4205 case LEN: /* i: get length/literal/eob next */
4206 j = c->sub.code.need;
4208 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4210 e = (uInt)(t->exop);
4211 if (e == 0) /* literal */
4213 c->sub.lit = t->base;
4214 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4215 "inflate: literal '%c'\n" :
4216 "inflate: literal 0x%02x\n", t->base));
4220 if (e & 16) /* length */
4222 c->sub.copy.get = e & 15;
4227 if ((e & 64) == 0) /* next table */
4229 c->sub.code.need = e;
4230 c->sub.code.tree = t->next;
4233 if (e & 32) /* end of block */
4235 Tracevv((stderr, "inflate: end of block\n"));
4239 c->mode = BADCODE; /* invalid code */
4240 z->msg = "invalid literal/length code";
4243 case LENEXT: /* i: getting length extra (have base) */
4244 j = c->sub.copy.get;
4246 c->len += (uInt)b & inflate_mask[j];
4248 c->sub.code.need = c->dbits;
4249 c->sub.code.tree = c->dtree;
4250 Tracevv((stderr, "inflate: length %u\n", c->len));
4252 case DIST: /* i: get distance next */
4253 j = c->sub.code.need;
4255 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4257 e = (uInt)(t->exop);
4258 if (e & 16) /* distance */
4260 c->sub.copy.get = e & 15;
4261 c->sub.copy.dist = t->base;
4265 if ((e & 64) == 0) /* next table */
4267 c->sub.code.need = e;
4268 c->sub.code.tree = t->next;
4271 c->mode = BADCODE; /* invalid code */
4272 z->msg = "invalid distance code";
4275 case DISTEXT: /* i: getting distance extra */
4276 j = c->sub.copy.get;
4278 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4280 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4282 case COPY: /* o: copying bytes in window, waiting for space */
4283 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4284 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4285 s->end - (c->sub.copy.dist - (q - s->window)) :
4286 q - c->sub.copy.dist;
4288 f = q - c->sub.copy.dist;
4289 if ((uInt)(q - s->window) < c->sub.copy.dist)
4290 f = s->end - (c->sub.copy.dist - (q - s->window));
4302 case LIT: /* o: got literal, waiting for output space */
4307 case WASH: /* o: got eob, possibly more output */
4309 if (s->read != s->write)
4315 case BADCODE: /* x: got error */
4325 local void inflate_codes_free(c, z)
4326 inflate_codes_statef *c;
4329 ZFREE(z, c, sizeof(struct inflate_codes_state));
4330 Tracev((stderr, "inflate: codes free\n"));
4334 /* inflate_util.c -- data and routines common to blocks and codes
4335 * Copyright (C) 1995 Mark Adler
4336 * For conditions of distribution and use, see copyright notice in zlib.h
4339 /* copy as much as possible from the sliding window to the output area */
4340 local int inflate_flush(s, z, r)
4341 inflate_blocks_statef *s;
4348 /* local copies of source and destination pointers */
4352 /* compute number of bytes to copy as far as end of window */
4353 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4354 if (n > z->avail_out) n = z->avail_out;
4355 if (n && r == Z_BUF_ERROR) r = Z_OK;
4357 /* update counters */
4361 /* update check information */
4362 if (s->checkfn != Z_NULL)
4363 s->check = (*s->checkfn)(s->check, q, n);
4365 /* copy as far as end of window */
4372 /* see if more to copy at beginning of window */
4377 if (s->write == s->end)
4378 s->write = s->window;
4380 /* compute bytes to copy */
4381 n = (uInt)(s->write - q);
4382 if (n > z->avail_out) n = z->avail_out;
4383 if (n && r == Z_BUF_ERROR) r = Z_OK;
4385 /* update counters */
4389 /* update check information */
4390 if (s->checkfn != Z_NULL)
4391 s->check = (*s->checkfn)(s->check, q, n);
4401 /* update pointers */
4411 /* inffast.c -- process literals and length/distance pairs fast
4412 * Copyright (C) 1995 Mark Adler
4413 * For conditions of distribution and use, see copyright notice in zlib.h
4416 /* simplify the use of the inflate_huft type with some defines */
4417 #define base more.Base
4418 #define next more.Next
4419 #define exop word.what.Exop
4420 #define bits word.what.Bits
4422 /* macros for bit input with no checking and for returning unused bytes */
4423 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4424 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4426 /* Called with number of bytes left to write in window at least 258
4427 (the maximum string length) and number of input bytes available
4428 at least ten. The ten bytes are six bytes for the longest length/
4429 distance pair plus four bytes for overloading the bit buffer. */
4431 local int inflate_fast(bl, bd, tl, td, s, z)
4433 inflate_huft *tl, *td;
4434 inflate_blocks_statef *s;
4437 inflate_huft *t; /* temporary pointer */
4438 uInt e; /* extra bits or operation */
4439 uLong b; /* bit buffer */
4440 uInt k; /* bits in bit buffer */
4441 Bytef *p; /* input data pointer */
4442 uInt n; /* bytes available there */
4443 Bytef *q; /* output window write pointer */
4444 uInt m; /* bytes to end of window or read pointer */
4445 uInt ml; /* mask for literal/length tree */
4446 uInt md; /* mask for distance tree */
4447 uInt c; /* bytes to copy */
4448 uInt d; /* distance back to copy from */
4449 Bytef *r; /* copy source pointer */
4451 /* load input, output, bit values */
4454 /* initialize masks */
4455 ml = inflate_mask[bl];
4456 md = inflate_mask[bd];
4458 /* do until not enough input or output space for fast loop */
4459 do { /* assume called with m >= 258 && n >= 10 */
4460 /* get literal/length code */
4461 GRABBITS(20) /* max bits for literal/length code */
4462 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4465 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4466 "inflate: * literal '%c'\n" :
4467 "inflate: * literal 0x%02x\n", t->base));
4468 *q++ = (Byte)t->base;
4476 /* get extra bits for length */
4478 c = t->base + ((uInt)b & inflate_mask[e]);
4480 Tracevv((stderr, "inflate: * length %u\n", c));
4482 /* decode distance base of block to copy */
4483 GRABBITS(15); /* max bits for distance code */
4484 e = (t = td + ((uInt)b & md))->exop;
4489 /* get extra bits to add to distance base */
4491 GRABBITS(e) /* get extra bits (up to 13) */
4492 d = t->base + ((uInt)b & inflate_mask[e]);
4494 Tracevv((stderr, "inflate: * distance %u\n", d));
4498 if ((uInt)(q - s->window) >= d) /* offset before dest */
4501 *q++ = *r++; c--; /* minimum count is three, */
4502 *q++ = *r++; c--; /* so unroll loop a little */
4504 else /* else offset after destination */
4506 e = d - (q - s->window); /* bytes from offset to end */
4507 r = s->end - e; /* pointer to offset */
4508 if (c > e) /* if source crosses, */
4510 c -= e; /* copy to end of window */
4514 r = s->window; /* copy rest from start of window */
4517 do { /* copy all or what's left */
4522 else if ((e & 64) == 0)
4523 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4526 z->msg = "invalid distance code";
4529 return Z_DATA_ERROR;
4536 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4539 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4540 "inflate: * literal '%c'\n" :
4541 "inflate: * literal 0x%02x\n", t->base));
4542 *q++ = (Byte)t->base;
4549 Tracevv((stderr, "inflate: * end of block\n"));
4552 return Z_STREAM_END;
4556 z->msg = "invalid literal/length code";
4559 return Z_DATA_ERROR;
4562 } while (m >= 258 && n >= 10);
4564 /* not enough input or output--restore pointers and return */
4572 /* zutil.c -- target dependent utility functions for the compression library
4573 * Copyright (C) 1995 Jean-loup Gailly.
4574 * For conditions of distribution and use, see copyright notice in zlib.h
4577 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
4579 char *zlib_version = ZLIB_VERSION;
4581 char *z_errmsg[] = {
4582 "stream end", /* Z_STREAM_END 1 */
4584 "file error", /* Z_ERRNO (-1) */
4585 "stream error", /* Z_STREAM_ERROR (-2) */
4586 "data error", /* Z_DATA_ERROR (-3) */
4587 "insufficient memory", /* Z_MEM_ERROR (-4) */
4588 "buffer error", /* Z_BUF_ERROR (-5) */
4593 /* adler32.c -- compute the Adler-32 checksum of a data stream
4594 * Copyright (C) 1995 Mark Adler
4595 * For conditions of distribution and use, see copyright notice in zlib.h
4598 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
4600 #define BASE 65521L /* largest prime smaller than 65536 */
4602 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4604 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4605 #define DO2(buf) DO1(buf); DO1(buf);
4606 #define DO4(buf) DO2(buf); DO2(buf);
4607 #define DO8(buf) DO4(buf); DO4(buf);
4608 #define DO16(buf) DO8(buf); DO8(buf);
4610 /* ========================================================================= */
4611 uLong adler32(adler, buf, len)
4616 unsigned long s1 = adler & 0xffff;
4617 unsigned long s2 = (adler >> 16) & 0xffff;
4620 if (buf == Z_NULL) return 1L;
4623 k = len < NMAX ? len : NMAX;
4635 return (s2 << 16) | s1;