2 * This file is a conglomeration of various .h and .c files
3 * from the zlib-0.95 library source, slightly hacked.
5 * Changes that have been made include:
6 * - changed functions not used outside this file to "local"
7 * - added minCompression parameter to deflateInit2
8 * - added Z_PACKET_FLUSH (see zlib.h for details)
9 * - added inflateIncomp
14 /* zutil.h -- internal interface and configuration of the compression library
15 * Copyright (C) 1995 Jean-loup Gailly.
16 * For conditions of distribution and use, see copyright notice in zlib.h
19 /* WARNING: this file should *not* be used by applications. It is
20 part of the implementation of the compression library and is
21 subject to change. Applications should only use zlib.h.
24 /* $Id: zlib.c,v 1.1 1996/01/18 03:26:49 paulus Exp $ */
37 /* compile with -Dlocal if your debugger can't find static symbols */
41 typedef unsigned char uch;
43 typedef unsigned short ush;
45 typedef unsigned long ulg;
47 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
49 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
50 /* To be used only when the state is known to be valid */
52 /* common constants */
57 # define DEF_WBITS MAX_WBITS
59 /* default windowBits for decompression. MAX_WBITS is for compression only */
61 #if MAX_MEM_LEVEL >= 8
62 # define DEF_MEM_LEVEL 8
64 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
66 /* default memLevel */
68 #define STORED_BLOCK 0
69 #define STATIC_TREES 1
71 /* The three kinds of block type */
75 /* The minimum and maximum match lengths */
79 #if defined(KERNEL) || defined(_KERNEL)
80 # define zmemcpy(d, s, n) bcopy((s), (d), (n))
81 # define zmemzero bzero
83 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
87 # define zmemcpy memcpy
88 # define zmemzero(dest, len) memset(dest, 0, len)
90 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
91 extern void zmemzero OF((Bytef* dest, uInt len));
95 /* Diagnostic functions */
101 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
102 # define Trace(x) fprintf x
103 # define Tracev(x) {if (verbose) fprintf x ;}
104 # define Tracevv(x) {if (verbose>1) fprintf x ;}
105 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
106 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
108 # define Assert(cond,msg)
113 # define Tracecv(c,x)
117 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
119 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
120 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
122 #define ZALLOC(strm, items, size) \
123 (*((strm)->zalloc))((strm)->opaque, (items), (size))
124 #define ZFREE(strm, addr, size) \
125 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
126 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
128 /* deflate.h -- internal compression state
129 * Copyright (C) 1995 Jean-loup Gailly
130 * For conditions of distribution and use, see copyright notice in zlib.h
133 /* WARNING: this file should *not* be used by applications. It is
134 part of the implementation of the compression library and is
135 subject to change. Applications should only use zlib.h.
140 /* $Id: zlib.c,v 1.1 1996/01/18 03:26:49 paulus Exp $ */
142 /* ===========================================================================
143 * Internal compression state.
151 #define LENGTH_CODES 29
152 /* number of length codes, not counting the special END_BLOCK code */
155 /* number of literal bytes 0..255 */
157 #define L_CODES (LITERALS+1+LENGTH_CODES)
158 /* number of Literal or Length codes, including the END_BLOCK code */
161 /* number of distance codes */
164 /* number of codes used to transfer the bit lengths */
166 #define HEAP_SIZE (2*L_CODES+1)
167 /* maximum heap size */
170 /* All codes must not exceed MAX_BITS bits */
172 #define INIT_STATE 42
173 #define BUSY_STATE 113
174 #define FLUSH_STATE 124
175 #define FINISH_STATE 666
179 /* Data structure describing a single value and its code string. */
180 typedef struct ct_data_s {
182 ush freq; /* frequency count */
183 ush code; /* bit string */
186 ush dad; /* father node in Huffman tree */
187 ush len; /* length of bit string */
196 typedef struct static_tree_desc_s static_tree_desc;
198 typedef struct tree_desc_s {
199 ct_data *dyn_tree; /* the dynamic tree */
200 int max_code; /* largest code with non zero frequency */
201 static_tree_desc *stat_desc; /* the corresponding static tree */
205 typedef Pos FAR Posf;
206 typedef unsigned IPos;
208 /* A Pos is an index in the character window. We use short instead of int to
209 * save space in the various tables. IPos is used only for parameter passing.
212 typedef struct deflate_state {
213 z_stream *strm; /* pointer back to this zlib stream */
214 int status; /* as the name implies */
215 Bytef *pending_buf; /* output still pending */
216 Bytef *pending_out; /* next pending byte to output to the stream */
217 int pending; /* nb of bytes in the pending buffer */
218 uLong adler; /* adler32 of uncompressed data */
219 int noheader; /* suppress zlib header and adler32 */
220 Byte data_type; /* UNKNOWN, BINARY or ASCII */
221 Byte method; /* STORED (for zip only) or DEFLATED */
222 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */
224 /* used by deflate.c: */
226 uInt w_size; /* LZ77 window size (32K by default) */
227 uInt w_bits; /* log2(w_size) (8..16) */
228 uInt w_mask; /* w_size - 1 */
231 /* Sliding window. Input bytes are read into the second half of the window,
232 * and move to the first half later to keep a dictionary of at least wSize
233 * bytes. With this organization, matches are limited to a distance of
234 * wSize-MAX_MATCH bytes, but this ensures that IO is always
235 * performed with a length multiple of the block size. Also, it limits
236 * the window size to 64K, which is quite useful on MSDOS.
237 * To do: use the user input buffer as sliding window.
241 /* Actual size of window: 2*wSize, except when the user input buffer
242 * is directly used as sliding window.
246 /* Link to older string with same hash index. To limit the size of this
247 * array to 64K, this link is maintained only for the last 32K strings.
248 * An index in this array is thus a window index modulo 32K.
251 Posf *head; /* Heads of the hash chains or NIL. */
253 uInt ins_h; /* hash index of string to be inserted */
254 uInt hash_size; /* number of elements in hash table */
255 uInt hash_bits; /* log2(hash_size) */
256 uInt hash_mask; /* hash_size-1 */
259 /* Number of bits by which ins_h must be shifted at each input
260 * step. It must be such that after MIN_MATCH steps, the oldest
261 * byte no longer takes part in the hash key, that is:
262 * hash_shift * MIN_MATCH >= hash_bits
266 /* Window position at the beginning of the current output block. Gets
267 * negative when the window is moved backwards.
270 uInt match_length; /* length of best match */
271 IPos prev_match; /* previous match */
272 int match_available; /* set if previous match exists */
273 uInt strstart; /* start of string to insert */
274 uInt match_start; /* start of matching string */
275 uInt lookahead; /* number of valid bytes ahead in window */
278 /* Length of the best match at previous step. Matches not greater than this
279 * are discarded. This is used in the lazy match evaluation.
282 uInt max_chain_length;
283 /* To speed up deflation, hash chains are never searched beyond this
284 * length. A higher limit improves compression ratio but degrades the
289 /* Attempt to find a better match only when the current match is strictly
290 * smaller than this value. This mechanism is used only for compression
293 # define max_insert_length max_lazy_match
294 /* Insert new strings in the hash table only if the match length is not
295 * greater than this length. This saves time but degrades compression.
296 * max_insert_length is used only for compression levels <= 3.
299 int level; /* compression level (1..9) */
300 int strategy; /* favor or force Huffman coding*/
303 /* Use a faster search when the previous match is longer than this */
305 int nice_match; /* Stop searching when current match exceeds this */
307 /* used by trees.c: */
308 /* Didn't use ct_data typedef below to supress compiler warning */
309 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
310 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
311 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
313 struct tree_desc_s l_desc; /* desc. for literal tree */
314 struct tree_desc_s d_desc; /* desc. for distance tree */
315 struct tree_desc_s bl_desc; /* desc. for bit length tree */
317 ush bl_count[MAX_BITS+1];
318 /* number of codes at each bit length for an optimal tree */
320 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
321 int heap_len; /* number of elements in the heap */
322 int heap_max; /* element of largest frequency */
323 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
324 * The same heap array is used to build all trees.
327 uch depth[2*L_CODES+1];
328 /* Depth of each subtree used as tie breaker for trees of equal frequency
331 uchf *l_buf; /* buffer for literals or lengths */
334 /* Size of match buffer for literals/lengths. There are 4 reasons for
335 * limiting lit_bufsize to 64K:
336 * - frequencies can be kept in 16 bit counters
337 * - if compression is not successful for the first block, all input
338 * data is still in the window so we can still emit a stored block even
339 * when input comes from standard input. (This can also be done for
340 * all blocks if lit_bufsize is not greater than 32K.)
341 * - if compression is not successful for a file smaller than 64K, we can
342 * even emit a stored file instead of a stored block (saving 5 bytes).
343 * This is applicable only for zip (not gzip or zlib).
344 * - creating new Huffman trees less frequently may not provide fast
345 * adaptation to changes in the input data statistics. (Take for
346 * example a binary file with poorly compressible code followed by
347 * a highly compressible string table.) Smaller buffer sizes give
348 * fast adaptation but have of course the overhead of transmitting
349 * trees more frequently.
350 * - I can't count above 4
353 uInt last_lit; /* running index in l_buf */
356 /* Buffer for distances. To simplify the code, d_buf and l_buf have
357 * the same number of elements. To use different lengths, an extra flag
358 * array would be necessary.
361 ulg opt_len; /* bit length of current block with optimal trees */
362 ulg static_len; /* bit length of current block with static trees */
363 ulg compressed_len; /* total bit length of compressed file */
364 uInt matches; /* number of string matches in current block */
365 int last_eob_len; /* bit length of EOB code for last block */
368 ulg bits_sent; /* bit length of the compressed data */
372 /* Output buffer. bits are inserted starting at the bottom (least
376 /* Number of valid bits in bi_buf. All bits above the last valid bit
380 uInt blocks_in_packet;
381 /* Number of blocks produced since the last time Z_PACKET_FLUSH
387 /* Output a byte on the stream.
388 * IN assertion: there is enough room in pending_buf.
390 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
393 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
394 /* Minimum amount of lookahead, except at the end of the input file.
395 * See deflate.c for comments about the MIN_MATCH+1.
398 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
399 /* In order to simplify the code, particularly on 16 bit machines, match
400 * distances are limited to MAX_DIST instead of WSIZE.
404 local void ct_init OF((deflate_state *s));
405 local int ct_tally OF((deflate_state *s, int dist, int lc));
406 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
408 local void ct_align OF((deflate_state *s));
409 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
411 local void ct_stored_type_only OF((deflate_state *s));
415 /* deflate.c -- compress data using the deflation algorithm
416 * Copyright (C) 1995 Jean-loup Gailly.
417 * For conditions of distribution and use, see copyright notice in zlib.h
423 * The "deflation" process depends on being able to identify portions
424 * of the input text which are identical to earlier input (within a
425 * sliding window trailing behind the input currently being processed).
427 * The most straightforward technique turns out to be the fastest for
428 * most input files: try all possible matches and select the longest.
429 * The key feature of this algorithm is that insertions into the string
430 * dictionary are very simple and thus fast, and deletions are avoided
431 * completely. Insertions are performed at each input character, whereas
432 * string matches are performed only when the previous match ends. So it
433 * is preferable to spend more time in matches to allow very fast string
434 * insertions and avoid deletions. The matching algorithm for small
435 * strings is inspired from that of Rabin & Karp. A brute force approach
436 * is used to find longer strings when a small match has been found.
437 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
438 * (by Leonid Broukhis).
439 * A previous version of this file used a more sophisticated algorithm
440 * (by Fiala and Greene) which is guaranteed to run in linear amortized
441 * time, but has a larger average cost, uses more memory and is patented.
442 * However the F&G algorithm may be faster for some highly redundant
443 * files if the parameter max_chain_length (described below) is too large.
447 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
448 * I found it in 'freeze' written by Leonid Broukhis.
449 * Thanks to many people for bug reports and testing.
453 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
454 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
456 * A description of the Rabin and Karp algorithm is given in the book
457 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
459 * Fiala,E.R., and Greene,D.H.
460 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
464 /* $Id: zlib.c,v 1.1 1996/01/18 03:26:49 paulus Exp $ */
466 local char copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
468 If you use the zlib library in a product, an acknowledgment is welcome
469 in the documentation of your product. If for some reason you cannot
470 include such an acknowledgment, I would appreciate that you keep this
471 copyright string in the executable of your product.
475 /* Tail of hash chains */
478 # define TOO_FAR 4096
480 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
482 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
483 /* Minimum amount of lookahead, except at the end of the input file.
484 * See deflate.c for comments about the MIN_MATCH+1.
487 /* Values for max_lazy_match, good_match and max_chain_length, depending on
488 * the desired pack level (0..9). The values given below have been tuned to
489 * exclude worst case performance for pathological files. Better values may be
490 * found for specific files.
493 typedef struct config_s {
494 ush good_length; /* reduce lazy search above this match length */
495 ush max_lazy; /* do not perform lazy search above this match length */
496 ush nice_length; /* quit search above this match length */
500 local config configuration_table[10] = {
501 /* good lazy nice chain */
502 /* 0 */ {0, 0, 0, 0}, /* store only */
503 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
504 /* 2 */ {4, 5, 16, 8},
505 /* 3 */ {4, 6, 32, 32},
507 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
508 /* 5 */ {8, 16, 32, 32},
509 /* 6 */ {8, 16, 128, 128},
510 /* 7 */ {8, 32, 128, 256},
511 /* 8 */ {32, 128, 258, 1024},
512 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
514 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
515 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
520 /* result of memcmp for equal strings */
522 /* ===========================================================================
523 * Prototypes for local functions.
526 local void fill_window OF((deflate_state *s));
527 local int deflate_fast OF((deflate_state *s, int flush));
528 local int deflate_slow OF((deflate_state *s, int flush));
529 local void lm_init OF((deflate_state *s));
530 local int longest_match OF((deflate_state *s, IPos cur_match));
531 local void putShortMSB OF((deflate_state *s, uInt b));
532 local void flush_pending OF((z_stream *strm));
533 local int read_buf OF((z_stream *strm, charf *buf, unsigned size));
535 void match_init OF((void)); /* asm code initialization */
539 local void check_match OF((deflate_state *s, IPos start, IPos match,
544 /* ===========================================================================
545 * Update a hash value with the given input byte
546 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
547 * input characters, so that a running hash key can be computed from the
548 * previous key instead of complete recalculation each time.
550 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
553 /* ===========================================================================
554 * Insert string str in the dictionary and set match_head to the previous head
555 * of the hash chain (the most recent string with same hash key). Return
556 * the previous length of the hash chain.
557 * IN assertion: all calls to to INSERT_STRING are made with consecutive
558 * input characters and the first MIN_MATCH bytes of str are valid
559 * (except for the last MIN_MATCH-1 bytes of the input file).
561 #define INSERT_STRING(s, str, match_head) \
562 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
563 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
564 s->head[s->ins_h] = (str))
566 /* ===========================================================================
567 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
568 * prev[] will be initialized on the fly.
570 #define CLEAR_HASH(s) \
571 s->head[s->hash_size-1] = NIL; \
572 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
574 /* ========================================================================= */
575 int deflateInit (strm, level)
579 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
581 /* To do: ignore strm->next_in if we use it as window */
584 /* ========================================================================= */
585 int deflateInit2 (strm, level, method, windowBits, memLevel,
586 strategy, minCompression)
598 if (strm == Z_NULL) return Z_STREAM_ERROR;
601 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
602 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
604 if (level == Z_DEFAULT_COMPRESSION) level = 6;
606 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
608 windowBits = -windowBits;
610 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
611 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
612 return Z_STREAM_ERROR;
614 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
615 if (s == Z_NULL) return Z_MEM_ERROR;
616 strm->state = (struct internal_state FAR *)s;
619 s->noheader = noheader;
620 s->w_bits = windowBits;
621 s->w_size = 1 << s->w_bits;
622 s->w_mask = s->w_size - 1;
624 s->hash_bits = memLevel + 7;
625 s->hash_size = 1 << s->hash_bits;
626 s->hash_mask = s->hash_size - 1;
627 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
629 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
630 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
631 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
633 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
635 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
637 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
638 s->pending_buf == Z_NULL) {
639 strm->msg = z_errmsg[1-Z_MEM_ERROR];
643 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
644 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
645 /* We overlay pending_buf and d_buf+l_buf. This works since the average
646 * output size for (length,distance) codes is <= 32 bits (worst case
651 s->strategy = strategy;
652 s->method = (Byte)method;
653 s->minCompr = minCompression;
654 s->blocks_in_packet = 0;
656 return deflateReset(strm);
659 /* ========================================================================= */
660 int deflateReset (strm)
665 if (strm == Z_NULL || strm->state == Z_NULL ||
666 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
668 strm->total_in = strm->total_out = 0;
669 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
670 strm->data_type = Z_UNKNOWN;
672 s = (deflate_state *)strm->state;
674 s->pending_out = s->pending_buf;
676 if (s->noheader < 0) {
677 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
679 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
688 /* =========================================================================
689 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
690 * IN assertion: the stream state is correct and there is enough room in
693 local void putShortMSB (s, b)
697 put_byte(s, (Byte)(b >> 8));
698 put_byte(s, (Byte)(b & 0xff));
701 /* =========================================================================
702 * Flush as much pending output as possible.
704 local void flush_pending(strm)
707 deflate_state *state = (deflate_state *) strm->state;
708 unsigned len = state->pending;
710 if (len > strm->avail_out) len = strm->avail_out;
711 if (len == 0) return;
713 if (strm->next_out != NULL) {
714 zmemcpy(strm->next_out, state->pending_out, len);
715 strm->next_out += len;
717 state->pending_out += len;
718 strm->total_out += len;
719 strm->avail_out -= len;
720 state->pending -= len;
721 if (state->pending == 0) {
722 state->pending_out = state->pending_buf;
726 /* ========================================================================= */
727 int deflate (strm, flush)
731 deflate_state *state = (deflate_state *) strm->state;
733 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
735 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
736 ERR_RETURN(strm, Z_STREAM_ERROR);
738 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
740 state->strm = strm; /* just in case */
742 /* Write the zlib header */
743 if (state->status == INIT_STATE) {
745 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
746 uInt level_flags = (state->level-1) >> 1;
748 if (level_flags > 3) level_flags = 3;
749 header |= (level_flags << 6);
750 header += 31 - (header % 31);
752 state->status = BUSY_STATE;
753 putShortMSB(state, header);
756 /* Flush as much pending output as possible */
757 if (state->pending != 0) {
759 if (strm->avail_out == 0) return Z_OK;
762 /* If we came back in here to get the last output from
763 * a previous flush, we're done for now.
765 if (state->status == FLUSH_STATE) {
766 state->status = BUSY_STATE;
767 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
771 /* User must not provide more input after the first FINISH: */
772 if (state->status == FINISH_STATE && strm->avail_in != 0) {
773 ERR_RETURN(strm, Z_BUF_ERROR);
776 /* Start a new block or continue the current one.
778 if (strm->avail_in != 0 || state->lookahead != 0 ||
779 (flush == Z_FINISH && state->status != FINISH_STATE)) {
782 if (flush == Z_FINISH) {
783 state->status = FINISH_STATE;
785 if (state->level <= 3) {
786 quit = deflate_fast(state, flush);
788 quit = deflate_slow(state, flush);
790 if (quit || strm->avail_out == 0)
792 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
793 * of deflate should use the same flush parameter to make sure
794 * that the flush is complete. So we don't have to output an
795 * empty block here, this will be done at next call. This also
796 * ensures that for a very small output buffer, we emit at most
801 /* If a flush was requested, we have a little more to output now. */
802 if (flush != Z_NO_FLUSH && flush != Z_FINISH
803 && state->status != FINISH_STATE) {
805 case Z_PARTIAL_FLUSH:
809 /* Output just the 3-bit `stored' block type value,
810 but not a zero length. */
811 ct_stored_type_only(state);
814 ct_stored_block(state, (char*)0, 0L, 0);
815 /* For a full flush, this empty block will be recognized
816 * as a special marker by inflate_sync().
818 if (flush == Z_FULL_FLUSH) {
819 CLEAR_HASH(state); /* forget history */
823 if (strm->avail_out == 0) {
824 /* We'll have to come back to get the rest of the output;
825 * this ensures we don't output a second zero-length stored
826 * block (or whatever).
828 state->status = FLUSH_STATE;
833 Assert(strm->avail_out > 0, "bug2");
835 if (flush != Z_FINISH) return Z_OK;
836 if (state->noheader) return Z_STREAM_END;
838 /* Write the zlib trailer (adler32) */
839 putShortMSB(state, (uInt)(state->adler >> 16));
840 putShortMSB(state, (uInt)(state->adler & 0xffff));
842 /* If avail_out is zero, the application will call deflate again
845 state->noheader = -1; /* write the trailer only once! */
846 return state->pending != 0 ? Z_OK : Z_STREAM_END;
849 /* ========================================================================= */
850 int deflateEnd (strm)
853 deflate_state *state = (deflate_state *) strm->state;
855 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
857 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
858 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
859 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
860 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
862 ZFREE(strm, state, sizeof(deflate_state));
863 strm->state = Z_NULL;
868 /* ===========================================================================
869 * Read a new buffer from the current input stream, update the adler32
870 * and total number of bytes read.
872 local int read_buf(strm, buf, size)
877 unsigned len = strm->avail_in;
878 deflate_state *state = (deflate_state *) strm->state;
880 if (len > size) len = size;
881 if (len == 0) return 0;
883 strm->avail_in -= len;
885 if (!state->noheader) {
886 state->adler = adler32(state->adler, strm->next_in, len);
888 zmemcpy(buf, strm->next_in, len);
889 strm->next_in += len;
890 strm->total_in += len;
895 /* ===========================================================================
896 * Initialize the "longest match" routines for a new zlib stream
898 local void lm_init (s)
901 s->window_size = (ulg)2L*s->w_size;
905 /* Set the default configuration parameters:
907 s->max_lazy_match = configuration_table[s->level].max_lazy;
908 s->good_match = configuration_table[s->level].good_length;
909 s->nice_match = configuration_table[s->level].nice_length;
910 s->max_chain_length = configuration_table[s->level].max_chain;
915 s->match_length = MIN_MATCH-1;
916 s->match_available = 0;
919 match_init(); /* initialize the asm code */
923 /* ===========================================================================
924 * Set match_start to the longest match starting at the given string and
925 * return its length. Matches shorter or equal to prev_length are discarded,
926 * in which case the result is equal to prev_length and match_start is
928 * IN assertions: cur_match is the head of the hash chain for the current
929 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
932 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
933 * match.S. The code will be functionally equivalent.
935 local int longest_match(s, cur_match)
937 IPos cur_match; /* current match */
939 unsigned chain_length = s->max_chain_length;/* max hash chain length */
940 register Bytef *scan = s->window + s->strstart; /* current string */
941 register Bytef *match; /* matched string */
942 register int len; /* length of current match */
943 int best_len = s->prev_length; /* best match length so far */
944 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
945 s->strstart - (IPos)MAX_DIST(s) : NIL;
946 /* Stop when cur_match becomes <= limit. To simplify the code,
947 * we prevent matches with the string of window index 0.
949 Posf *prev = s->prev;
950 uInt wmask = s->w_mask;
953 /* Compare two bytes at a time. Note: this is not always beneficial.
954 * Try with and without -DUNALIGNED_OK to check.
956 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
957 register ush scan_start = *(ushf*)scan;
958 register ush scan_end = *(ushf*)(scan+best_len-1);
960 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
961 register Byte scan_end1 = scan[best_len-1];
962 register Byte scan_end = scan[best_len];
965 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
966 * It is easy to get rid of this optimization if necessary.
968 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
970 /* Do not waste too much time if we already have a good match: */
971 if (s->prev_length >= s->good_match) {
974 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
977 Assert(cur_match < s->strstart, "no future");
978 match = s->window + cur_match;
980 /* Skip to next match if the match length cannot increase
981 * or if the match length is less than 2:
983 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
984 /* This code assumes sizeof(unsigned short) == 2. Do not use
985 * UNALIGNED_OK if your compiler uses a different size.
987 if (*(ushf*)(match+best_len-1) != scan_end ||
988 *(ushf*)match != scan_start) continue;
990 /* It is not necessary to compare scan[2] and match[2] since they are
991 * always equal when the other bytes match, given that the hash keys
992 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
993 * strstart+3, +5, ... up to strstart+257. We check for insufficient
994 * lookahead only every 4th comparison; the 128th check will be made
995 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
996 * necessary to put more guard bytes at the end of the window, or
997 * to check more often for insufficient lookahead.
999 Assert(scan[2] == match[2], "scan[2]?");
1002 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1003 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1004 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1005 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1007 /* The funny "do {}" generates better code on most compilers */
1009 /* Here, scan <= window+strstart+257 */
1010 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1011 if (*scan == *match) scan++;
1013 len = (MAX_MATCH - 1) - (int)(strend-scan);
1014 scan = strend - (MAX_MATCH-1);
1016 #else /* UNALIGNED_OK */
1018 if (match[best_len] != scan_end ||
1019 match[best_len-1] != scan_end1 ||
1021 *++match != scan[1]) continue;
1023 /* The check at best_len-1 can be removed because it will be made
1024 * again later. (This heuristic is not always a win.)
1025 * It is not necessary to compare scan[2] and match[2] since they
1026 * are always equal when the other bytes match, given that
1027 * the hash keys are equal and that HASH_BITS >= 8.
1030 Assert(*scan == *match, "match[2]?");
1032 /* We check for insufficient lookahead only every 8th comparison;
1033 * the 256th check will be made at strstart+258.
1036 } while (*++scan == *++match && *++scan == *++match &&
1037 *++scan == *++match && *++scan == *++match &&
1038 *++scan == *++match && *++scan == *++match &&
1039 *++scan == *++match && *++scan == *++match &&
1042 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1044 len = MAX_MATCH - (int)(strend - scan);
1045 scan = strend - MAX_MATCH;
1047 #endif /* UNALIGNED_OK */
1049 if (len > best_len) {
1050 s->match_start = cur_match;
1052 if (len >= s->nice_match) break;
1054 scan_end = *(ushf*)(scan+best_len-1);
1056 scan_end1 = scan[best_len-1];
1057 scan_end = scan[best_len];
1060 } while ((cur_match = prev[cur_match & wmask]) > limit
1061 && --chain_length != 0);
1068 /* ===========================================================================
1069 * Check that the match at match_start is indeed a match.
1071 local void check_match(s, start, match, length)
1076 /* check that the match is indeed a match */
1077 if (memcmp((charf *)s->window + match,
1078 (charf *)s->window + start, length) != EQUAL) {
1080 " start %u, match %u, length %d\n",
1081 start, match, length);
1082 do { fprintf(stderr, "%c%c", s->window[match++],
1083 s->window[start++]); } while (--length != 0);
1084 z_error("invalid match");
1087 fprintf(stderr,"\\[%d,%d]", start-match, length);
1088 do { putc(s->window[start++], stderr); } while (--length != 0);
1092 # define check_match(s, start, match, length)
1095 /* ===========================================================================
1096 * Fill the window when the lookahead becomes insufficient.
1097 * Updates strstart and lookahead.
1099 * IN assertion: lookahead < MIN_LOOKAHEAD
1100 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1101 * At least one byte has been read, or avail_in == 0; reads are
1102 * performed for at least two bytes (required for the zip translate_eol
1103 * option -- not supported here).
1105 local void fill_window(s)
1108 register unsigned n, m;
1110 unsigned more; /* Amount of free space at the end of the window. */
1111 uInt wsize = s->w_size;
1114 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1116 /* Deal with !@#$% 64K limit: */
1117 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1119 } else if (more == (unsigned)(-1)) {
1120 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1121 * and lookahead == 1 (input done one byte at time)
1125 /* If the window is almost full and there is insufficient lookahead,
1126 * move the upper half to the lower one to make room in the upper half.
1128 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1130 /* By the IN assertion, the window is not empty so we can't confuse
1131 * more == 0 with more == 64K on a 16 bit machine.
1133 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1135 s->match_start -= wsize;
1136 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1138 s->block_start -= (long) wsize;
1140 /* Slide the hash table (could be avoided with 32 bit values
1141 at the expense of memory usage):
1147 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1154 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1155 /* If n is not on any hash chain, prev[n] is garbage but
1156 * its value will never be used.
1162 if (s->strm->avail_in == 0) return;
1164 /* If there was no sliding:
1165 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1166 * more == window_size - lookahead - strstart
1167 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1168 * => more >= window_size - 2*WSIZE + 2
1169 * In the BIG_MEM or MMAP case (not yet supported),
1170 * window_size == input_size + MIN_LOOKAHEAD &&
1171 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1172 * Otherwise, window_size == 2*WSIZE so more >= 2.
1173 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1175 Assert(more >= 2, "more < 2");
1177 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1181 /* Initialize the hash value now that we have some input: */
1182 if (s->lookahead >= MIN_MATCH) {
1183 s->ins_h = s->window[s->strstart];
1184 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1186 Call UPDATE_HASH() MIN_MATCH-3 more times
1189 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1190 * but this is not important since only literal bytes will be emitted.
1193 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1196 /* ===========================================================================
1197 * Flush the current block, with given end-of-file flag.
1198 * IN assertion: strstart is set to the end of the current match.
1200 #define FLUSH_BLOCK_ONLY(s, flush) { \
1201 ct_flush_block(s, (s->block_start >= 0L ? \
1202 (charf *)&s->window[(unsigned)s->block_start] : \
1203 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1204 s->block_start = s->strstart; \
1205 flush_pending(s->strm); \
1206 Tracev((stderr,"[FLUSH]")); \
1209 /* Same but force premature exit if necessary. */
1210 #define FLUSH_BLOCK(s, flush) { \
1211 FLUSH_BLOCK_ONLY(s, flush); \
1212 if (s->strm->avail_out == 0) return 1; \
1215 /* ===========================================================================
1216 * Compress as much as possible from the input stream, return true if
1217 * processing was terminated prematurely (no more input or output space).
1218 * This function does not perform lazy evaluationof matches and inserts
1219 * new strings in the dictionary only for unmatched strings or for short
1220 * matches. It is used only for the fast compression options.
1222 local int deflate_fast(s, flush)
1226 IPos hash_head; /* head of the hash chain */
1227 int bflush; /* set if current block must be flushed */
1229 s->prev_length = MIN_MATCH-1;
1232 /* Make sure that we always have enough lookahead, except
1233 * at the end of the input file. We need MAX_MATCH bytes
1234 * for the next match, plus MIN_MATCH bytes to insert the
1235 * string following the next match.
1237 if (s->lookahead < MIN_LOOKAHEAD) {
1239 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1241 if (s->lookahead == 0) break; /* flush the current block */
1244 /* Insert the string window[strstart .. strstart+2] in the
1245 * dictionary, and set hash_head to the head of the hash chain:
1247 if (s->lookahead >= MIN_MATCH) {
1248 INSERT_STRING(s, s->strstart, hash_head);
1251 /* Find the longest match, discarding those <= prev_length.
1252 * At this point we have always match_length < MIN_MATCH
1254 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1255 /* To simplify the code, we prevent matches with the string
1256 * of window index 0 (in particular we have to avoid a match
1257 * of the string with itself at the start of the input file).
1259 if (s->strategy != Z_HUFFMAN_ONLY) {
1260 s->match_length = longest_match (s, hash_head);
1262 /* longest_match() sets match_start */
1264 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1266 if (s->match_length >= MIN_MATCH) {
1267 check_match(s, s->strstart, s->match_start, s->match_length);
1269 bflush = ct_tally(s, s->strstart - s->match_start,
1270 s->match_length - MIN_MATCH);
1272 s->lookahead -= s->match_length;
1274 /* Insert new strings in the hash table only if the match length
1275 * is not too large. This saves time but degrades compression.
1277 if (s->match_length <= s->max_insert_length &&
1278 s->lookahead >= MIN_MATCH) {
1279 s->match_length--; /* string at strstart already in hash table */
1282 INSERT_STRING(s, s->strstart, hash_head);
1283 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1284 * always MIN_MATCH bytes ahead.
1286 } while (--s->match_length != 0);
1289 s->strstart += s->match_length;
1290 s->match_length = 0;
1291 s->ins_h = s->window[s->strstart];
1292 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1294 Call UPDATE_HASH() MIN_MATCH-3 more times
1296 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1297 * matter since it will be recomputed at next deflate call.
1301 /* No match, output a literal byte */
1302 Tracevv((stderr,"%c", s->window[s->strstart]));
1303 bflush = ct_tally (s, 0, s->window[s->strstart]);
1307 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1309 FLUSH_BLOCK(s, flush);
1310 return 0; /* normal exit */
1313 /* ===========================================================================
1314 * Same as above, but achieves better compression. We use a lazy
1315 * evaluation for matches: a match is finally adopted only if there is
1316 * no better match at the next window position.
1318 local int deflate_slow(s, flush)
1322 IPos hash_head; /* head of hash chain */
1323 int bflush; /* set if current block must be flushed */
1325 /* Process the input block. */
1327 /* Make sure that we always have enough lookahead, except
1328 * at the end of the input file. We need MAX_MATCH bytes
1329 * for the next match, plus MIN_MATCH bytes to insert the
1330 * string following the next match.
1332 if (s->lookahead < MIN_LOOKAHEAD) {
1334 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1336 if (s->lookahead == 0) break; /* flush the current block */
1339 /* Insert the string window[strstart .. strstart+2] in the
1340 * dictionary, and set hash_head to the head of the hash chain:
1342 if (s->lookahead >= MIN_MATCH) {
1343 INSERT_STRING(s, s->strstart, hash_head);
1346 /* Find the longest match, discarding those <= prev_length.
1348 s->prev_length = s->match_length, s->prev_match = s->match_start;
1349 s->match_length = MIN_MATCH-1;
1351 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1352 s->strstart - hash_head <= MAX_DIST(s)) {
1353 /* To simplify the code, we prevent matches with the string
1354 * of window index 0 (in particular we have to avoid a match
1355 * of the string with itself at the start of the input file).
1357 if (s->strategy != Z_HUFFMAN_ONLY) {
1358 s->match_length = longest_match (s, hash_head);
1360 /* longest_match() sets match_start */
1361 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1363 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1364 (s->match_length == MIN_MATCH &&
1365 s->strstart - s->match_start > TOO_FAR))) {
1367 /* If prev_match is also MIN_MATCH, match_start is garbage
1368 * but we will ignore the current match anyway.
1370 s->match_length = MIN_MATCH-1;
1373 /* If there was a match at the previous step and the current
1374 * match is not better, output the previous match:
1376 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1377 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1378 /* Do not insert strings in hash table beyond this. */
1380 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1382 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1383 s->prev_length - MIN_MATCH);
1385 /* Insert in hash table all strings up to the end of the match.
1386 * strstart-1 and strstart are already inserted. If there is not
1387 * enough lookahead, the last two strings are not inserted in
1390 s->lookahead -= s->prev_length-1;
1391 s->prev_length -= 2;
1393 if (++s->strstart <= max_insert) {
1394 INSERT_STRING(s, s->strstart, hash_head);
1396 } while (--s->prev_length != 0);
1397 s->match_available = 0;
1398 s->match_length = MIN_MATCH-1;
1401 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1403 } else if (s->match_available) {
1404 /* If there was no match at the previous position, output a
1405 * single literal. If there was a match but the current match
1406 * is longer, truncate the previous match to a single literal.
1408 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1409 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1410 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1414 if (s->strm->avail_out == 0) return 1;
1416 /* There is no previous match to compare with, wait for
1417 * the next step to decide.
1419 s->match_available = 1;
1424 Assert (flush != Z_NO_FLUSH, "no flush?");
1425 if (s->match_available) {
1426 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1427 ct_tally (s, 0, s->window[s->strstart-1]);
1428 s->match_available = 0;
1430 FLUSH_BLOCK(s, flush);
1436 /* trees.c -- output deflated data using Huffman coding
1437 * Copyright (C) 1995 Jean-loup Gailly
1438 * For conditions of distribution and use, see copyright notice in zlib.h
1444 * The "deflation" process uses several Huffman trees. The more
1445 * common source values are represented by shorter bit sequences.
1447 * Each code tree is stored in a compressed form which is itself
1448 * a Huffman encoding of the lengths of all the code strings (in
1449 * ascending order by source values). The actual code strings are
1450 * reconstructed from the lengths in the inflate process, as described
1451 * in the deflate specification.
1455 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1456 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1459 * Data Compression: Methods and Theory, pp. 49-50.
1460 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1464 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1467 /* $Id: zlib.c,v 1.1 1996/01/18 03:26:49 paulus Exp $ */
1473 /* ===========================================================================
1477 #define MAX_BL_BITS 7
1478 /* Bit length codes must not exceed MAX_BL_BITS bits */
1480 #define END_BLOCK 256
1481 /* end of block literal code */
1484 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1486 #define REPZ_3_10 17
1487 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1489 #define REPZ_11_138 18
1490 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1492 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1493 = {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};
1495 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1496 = {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};
1498 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1499 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1501 local uch bl_order[BL_CODES]
1502 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1503 /* The lengths of the bit length codes are sent in order of decreasing
1504 * probability, to avoid transmitting the lengths for unused bit length codes.
1507 #define Buf_size (8 * 2*sizeof(char))
1508 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1509 * more than 16 bits on some systems.)
1512 /* ===========================================================================
1513 * Local data. These are initialized only once.
1514 * To do: initialize at compile time to be completely reentrant. ???
1517 local ct_data static_ltree[L_CODES+2];
1518 /* The static literal tree. Since the bit lengths are imposed, there is no
1519 * need for the L_CODES extra codes used during heap construction. However
1520 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1524 local ct_data static_dtree[D_CODES];
1525 /* The static distance tree. (Actually a trivial tree since all codes use
1529 local uch dist_code[512];
1530 /* distance codes. The first 256 values correspond to the distances
1531 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1532 * the 15 bit distances.
1535 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1536 /* length code for each normalized match length (0 == MIN_MATCH) */
1538 local int base_length[LENGTH_CODES];
1539 /* First normalized length for each code (0 = MIN_MATCH) */
1541 local int base_dist[D_CODES];
1542 /* First normalized distance for each code (0 = distance of 1) */
1544 struct static_tree_desc_s {
1545 ct_data *static_tree; /* static tree or NULL */
1546 intf *extra_bits; /* extra bits for each code or NULL */
1547 int extra_base; /* base index for extra_bits */
1548 int elems; /* max number of elements in the tree */
1549 int max_length; /* max bit length for the codes */
1552 local static_tree_desc static_l_desc =
1553 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1555 local static_tree_desc static_d_desc =
1556 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1558 local static_tree_desc static_bl_desc =
1559 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1561 /* ===========================================================================
1562 * Local (static) routines in this file.
1565 local void ct_static_init OF((void));
1566 local void init_block OF((deflate_state *s));
1567 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1568 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1569 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1570 local void build_tree OF((deflate_state *s, tree_desc *desc));
1571 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1572 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1573 local int build_bl_tree OF((deflate_state *s));
1574 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1576 local void compress_block OF((deflate_state *s, ct_data *ltree,
1578 local void set_data_type OF((deflate_state *s));
1579 local unsigned bi_reverse OF((unsigned value, int length));
1580 local void bi_windup OF((deflate_state *s));
1581 local void bi_flush OF((deflate_state *s));
1582 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1586 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1587 /* Send a code of the given tree. c and tree must not have side effects */
1589 #else /* DEBUG_ZLIB */
1590 # define send_code(s, c, tree) \
1591 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1592 send_bits(s, tree[c].Code, tree[c].Len); }
1595 #define d_code(dist) \
1596 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1597 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1598 * must not have side effects. dist_code[256] and dist_code[257] are never
1602 /* ===========================================================================
1603 * Output a short LSB first on the stream.
1604 * IN assertion: there is enough room in pendingBuf.
1606 #define put_short(s, w) { \
1607 put_byte(s, (uch)((w) & 0xff)); \
1608 put_byte(s, (uch)((ush)(w) >> 8)); \
1611 /* ===========================================================================
1612 * Send a value on a given number of bits.
1613 * IN assertion: length <= 16 and value fits in length bits.
1616 local void send_bits OF((deflate_state *s, int value, int length));
1618 local void send_bits(s, value, length)
1620 int value; /* value to send */
1621 int length; /* number of bits */
1623 Tracev((stderr," l %2d v %4x ", length, value));
1624 Assert(length > 0 && length <= 15, "invalid length");
1625 s->bits_sent += (ulg)length;
1627 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1628 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1629 * unused bits in value.
1631 if (s->bi_valid > (int)Buf_size - length) {
1632 s->bi_buf |= (value << s->bi_valid);
1633 put_short(s, s->bi_buf);
1634 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1635 s->bi_valid += length - Buf_size;
1637 s->bi_buf |= value << s->bi_valid;
1638 s->bi_valid += length;
1641 #else /* !DEBUG_ZLIB */
1643 #define send_bits(s, value, length) \
1644 { int len = length;\
1645 if (s->bi_valid > (int)Buf_size - len) {\
1647 s->bi_buf |= (val << s->bi_valid);\
1648 put_short(s, s->bi_buf);\
1649 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1650 s->bi_valid += len - Buf_size;\
1652 s->bi_buf |= (value) << s->bi_valid;\
1653 s->bi_valid += len;\
1656 #endif /* DEBUG_ZLIB */
1659 #define MAX(a,b) (a >= b ? a : b)
1660 /* the arguments must not have side effects */
1662 /* ===========================================================================
1663 * Initialize the various 'constant' tables.
1664 * To do: do this at compile time.
1666 local void ct_static_init()
1668 int n; /* iterates over tree elements */
1669 int bits; /* bit counter */
1670 int length; /* length value */
1671 int code; /* code value */
1672 int dist; /* distance index */
1673 ush bl_count[MAX_BITS+1];
1674 /* number of codes at each bit length for an optimal tree */
1676 /* Initialize the mapping length (0..255) -> length code (0..28) */
1678 for (code = 0; code < LENGTH_CODES-1; code++) {
1679 base_length[code] = length;
1680 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1681 length_code[length++] = (uch)code;
1684 Assert (length == 256, "ct_static_init: length != 256");
1685 /* Note that the length 255 (match length 258) can be represented
1686 * in two different ways: code 284 + 5 bits or code 285, so we
1687 * overwrite length_code[255] to use the best encoding:
1689 length_code[length-1] = (uch)code;
1691 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1693 for (code = 0 ; code < 16; code++) {
1694 base_dist[code] = dist;
1695 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1696 dist_code[dist++] = (uch)code;
1699 Assert (dist == 256, "ct_static_init: dist != 256");
1700 dist >>= 7; /* from now on, all distances are divided by 128 */
1701 for ( ; code < D_CODES; code++) {
1702 base_dist[code] = dist << 7;
1703 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1704 dist_code[256 + dist++] = (uch)code;
1707 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1709 /* Construct the codes of the static literal tree */
1710 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1712 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1713 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1714 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1715 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1716 /* Codes 286 and 287 do not exist, but we must include them in the
1717 * tree construction to get a canonical Huffman tree (longest code
1720 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1722 /* The static distance tree is trivial: */
1723 for (n = 0; n < D_CODES; n++) {
1724 static_dtree[n].Len = 5;
1725 static_dtree[n].Code = bi_reverse(n, 5);
1729 /* ===========================================================================
1730 * Initialize the tree data structures for a new zlib stream.
1732 local void ct_init(s)
1735 if (static_dtree[0].Len == 0) {
1736 ct_static_init(); /* To do: at compile time */
1739 s->compressed_len = 0L;
1741 s->l_desc.dyn_tree = s->dyn_ltree;
1742 s->l_desc.stat_desc = &static_l_desc;
1744 s->d_desc.dyn_tree = s->dyn_dtree;
1745 s->d_desc.stat_desc = &static_d_desc;
1747 s->bl_desc.dyn_tree = s->bl_tree;
1748 s->bl_desc.stat_desc = &static_bl_desc;
1752 s->last_eob_len = 8; /* enough lookahead for inflate */
1756 s->blocks_in_packet = 0;
1758 /* Initialize the first block of the first file: */
1762 /* ===========================================================================
1763 * Initialize a new block.
1765 local void init_block(s)
1768 int n; /* iterates over tree elements */
1770 /* Initialize the trees. */
1771 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1772 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1773 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1775 s->dyn_ltree[END_BLOCK].Freq = 1;
1776 s->opt_len = s->static_len = 0L;
1777 s->last_lit = s->matches = 0;
1781 /* Index within the heap array of least frequent node in the Huffman tree */
1784 /* ===========================================================================
1785 * Remove the smallest element from the heap and recreate the heap with
1786 * one less element. Updates heap and heap_len.
1788 #define pqremove(s, tree, top) \
1790 top = s->heap[SMALLEST]; \
1791 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1792 pqdownheap(s, tree, SMALLEST); \
1795 /* ===========================================================================
1796 * Compares to subtrees, using the tree depth as tie breaker when
1797 * the subtrees have equal frequency. This minimizes the worst case length.
1799 #define smaller(tree, n, m, depth) \
1800 (tree[n].Freq < tree[m].Freq || \
1801 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1803 /* ===========================================================================
1804 * Restore the heap property by moving down the tree starting at node k,
1805 * exchanging a node with the smallest of its two sons if necessary, stopping
1806 * when the heap property is re-established (each father smaller than its
1809 local void pqdownheap(s, tree, k)
1811 ct_data *tree; /* the tree to restore */
1812 int k; /* node to move down */
1815 int j = k << 1; /* left son of k */
1816 while (j <= s->heap_len) {
1817 /* Set j to the smallest of the two sons: */
1818 if (j < s->heap_len &&
1819 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1822 /* Exit if v is smaller than both sons */
1823 if (smaller(tree, v, s->heap[j], s->depth)) break;
1825 /* Exchange v with the smallest son */
1826 s->heap[k] = s->heap[j]; k = j;
1828 /* And continue down the tree, setting j to the left son of k */
1834 /* ===========================================================================
1835 * Compute the optimal bit lengths for a tree and update the total bit length
1836 * for the current block.
1837 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1838 * above are the tree nodes sorted by increasing frequency.
1839 * OUT assertions: the field len is set to the optimal bit length, the
1840 * array bl_count contains the frequencies for each bit length.
1841 * The length opt_len is updated; static_len is also updated if stree is
1844 local void gen_bitlen(s, desc)
1846 tree_desc *desc; /* the tree descriptor */
1848 ct_data *tree = desc->dyn_tree;
1849 int max_code = desc->max_code;
1850 ct_data *stree = desc->stat_desc->static_tree;
1851 intf *extra = desc->stat_desc->extra_bits;
1852 int base = desc->stat_desc->extra_base;
1853 int max_length = desc->stat_desc->max_length;
1854 int h; /* heap index */
1855 int n, m; /* iterate over the tree elements */
1856 int bits; /* bit length */
1857 int xbits; /* extra bits */
1858 ush f; /* frequency */
1859 int overflow = 0; /* number of elements with bit length too large */
1861 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1863 /* In a first pass, compute the optimal bit lengths (which may
1864 * overflow in the case of the bit length tree).
1866 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1868 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1870 bits = tree[tree[n].Dad].Len + 1;
1871 if (bits > max_length) bits = max_length, overflow++;
1872 tree[n].Len = (ush)bits;
1873 /* We overwrite tree[n].Dad which is no longer needed */
1875 if (n > max_code) continue; /* not a leaf node */
1877 s->bl_count[bits]++;
1879 if (n >= base) xbits = extra[n-base];
1881 s->opt_len += (ulg)f * (bits + xbits);
1882 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1884 if (overflow == 0) return;
1886 Trace((stderr,"\nbit length overflow\n"));
1887 /* This happens for example on obj2 and pic of the Calgary corpus */
1889 /* Find the first bit length which could increase: */
1891 bits = max_length-1;
1892 while (s->bl_count[bits] == 0) bits--;
1893 s->bl_count[bits]--; /* move one leaf down the tree */
1894 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1895 s->bl_count[max_length]--;
1896 /* The brother of the overflow item also moves one step up,
1897 * but this does not affect bl_count[max_length]
1900 } while (overflow > 0);
1902 /* Now recompute all bit lengths, scanning in increasing frequency.
1903 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1904 * lengths instead of fixing only the wrong ones. This idea is taken
1905 * from 'ar' written by Haruhiko Okumura.)
1907 for (bits = max_length; bits != 0; bits--) {
1908 n = s->bl_count[bits];
1911 if (m > max_code) continue;
1912 if (tree[m].Len != (unsigned) bits) {
1913 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1914 s->opt_len += ((long)bits - (long)tree[m].Len)
1915 *(long)tree[m].Freq;
1916 tree[m].Len = (ush)bits;
1923 /* ===========================================================================
1924 * Generate the codes for a given tree and bit counts (which need not be
1926 * IN assertion: the array bl_count contains the bit length statistics for
1927 * the given tree and the field len is set for all tree elements.
1928 * OUT assertion: the field code is set for all tree elements of non
1931 local void gen_codes (tree, max_code, bl_count)
1932 ct_data *tree; /* the tree to decorate */
1933 int max_code; /* largest code with non zero frequency */
1934 ushf *bl_count; /* number of codes at each bit length */
1936 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1937 ush code = 0; /* running code value */
1938 int bits; /* bit index */
1939 int n; /* code index */
1941 /* The distribution counts are first used to generate the code values
1942 * without bit reversal.
1944 for (bits = 1; bits <= MAX_BITS; bits++) {
1945 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1947 /* Check that the bit counts in bl_count are consistent. The last code
1950 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1951 "inconsistent bit counts");
1952 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1954 for (n = 0; n <= max_code; n++) {
1955 int len = tree[n].Len;
1956 if (len == 0) continue;
1957 /* Now reverse the bits */
1958 tree[n].Code = bi_reverse(next_code[len]++, len);
1960 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1961 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1965 /* ===========================================================================
1966 * Construct one Huffman tree and assigns the code bit strings and lengths.
1967 * Update the total bit length for the current block.
1968 * IN assertion: the field freq is set for all tree elements.
1969 * OUT assertions: the fields len and code are set to the optimal bit length
1970 * and corresponding code. The length opt_len is updated; static_len is
1971 * also updated if stree is not null. The field max_code is set.
1973 local void build_tree(s, desc)
1975 tree_desc *desc; /* the tree descriptor */
1977 ct_data *tree = desc->dyn_tree;
1978 ct_data *stree = desc->stat_desc->static_tree;
1979 int elems = desc->stat_desc->elems;
1980 int n, m; /* iterate over heap elements */
1981 int max_code = -1; /* largest code with non zero frequency */
1982 int node; /* new node being created */
1984 /* Construct the initial heap, with least frequent element in
1985 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
1986 * heap[0] is not used.
1988 s->heap_len = 0, s->heap_max = HEAP_SIZE;
1990 for (n = 0; n < elems; n++) {
1991 if (tree[n].Freq != 0) {
1992 s->heap[++(s->heap_len)] = max_code = n;
1999 /* The pkzip format requires that at least one distance code exists,
2000 * and that at least one bit should be sent even if there is only one
2001 * possible code. So to avoid special checks later on we force at least
2002 * two codes of non zero frequency.
2004 while (s->heap_len < 2) {
2005 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2006 tree[node].Freq = 1;
2008 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2009 /* node is 0 or 1 so it does not have extra bits */
2011 desc->max_code = max_code;
2013 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2014 * establish sub-heaps of increasing lengths:
2016 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2018 /* Construct the Huffman tree by repeatedly combining the least two
2021 node = elems; /* next internal node of the tree */
2023 pqremove(s, tree, n); /* n = node of least frequency */
2024 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2026 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2027 s->heap[--(s->heap_max)] = m;
2029 /* Create a new node father of n and m */
2030 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2031 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2032 tree[n].Dad = tree[m].Dad = (ush)node;
2034 if (tree == s->bl_tree) {
2035 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2036 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2039 /* and insert the new node in the heap */
2040 s->heap[SMALLEST] = node++;
2041 pqdownheap(s, tree, SMALLEST);
2043 } while (s->heap_len >= 2);
2045 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2047 /* At this point, the fields freq and dad are set. We can now
2048 * generate the bit lengths.
2050 gen_bitlen(s, (tree_desc *)desc);
2052 /* The field len is now set, we can generate the bit codes */
2053 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2056 /* ===========================================================================
2057 * Scan a literal or distance tree to determine the frequencies of the codes
2058 * in the bit length tree.
2060 local void scan_tree (s, tree, max_code)
2062 ct_data *tree; /* the tree to be scanned */
2063 int max_code; /* and its largest code of non zero frequency */
2065 int n; /* iterates over all tree elements */
2066 int prevlen = -1; /* last emitted length */
2067 int curlen; /* length of current code */
2068 int nextlen = tree[0].Len; /* length of next code */
2069 int count = 0; /* repeat count of the current code */
2070 int max_count = 7; /* max repeat count */
2071 int min_count = 4; /* min repeat count */
2073 if (nextlen == 0) max_count = 138, min_count = 3;
2074 tree[max_code+1].Len = (ush)0xffff; /* guard */
2076 for (n = 0; n <= max_code; n++) {
2077 curlen = nextlen; nextlen = tree[n+1].Len;
2078 if (++count < max_count && curlen == nextlen) {
2080 } else if (count < min_count) {
2081 s->bl_tree[curlen].Freq += count;
2082 } else if (curlen != 0) {
2083 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2084 s->bl_tree[REP_3_6].Freq++;
2085 } else if (count <= 10) {
2086 s->bl_tree[REPZ_3_10].Freq++;
2088 s->bl_tree[REPZ_11_138].Freq++;
2090 count = 0; prevlen = curlen;
2092 max_count = 138, min_count = 3;
2093 } else if (curlen == nextlen) {
2094 max_count = 6, min_count = 3;
2096 max_count = 7, min_count = 4;
2101 /* ===========================================================================
2102 * Send a literal or distance tree in compressed form, using the codes in
2105 local void send_tree (s, tree, max_code)
2107 ct_data *tree; /* the tree to be scanned */
2108 int max_code; /* and its largest code of non zero frequency */
2110 int n; /* iterates over all tree elements */
2111 int prevlen = -1; /* last emitted length */
2112 int curlen; /* length of current code */
2113 int nextlen = tree[0].Len; /* length of next code */
2114 int count = 0; /* repeat count of the current code */
2115 int max_count = 7; /* max repeat count */
2116 int min_count = 4; /* min repeat count */
2118 /* tree[max_code+1].Len = -1; */ /* guard already set */
2119 if (nextlen == 0) max_count = 138, min_count = 3;
2121 for (n = 0; n <= max_code; n++) {
2122 curlen = nextlen; nextlen = tree[n+1].Len;
2123 if (++count < max_count && curlen == nextlen) {
2125 } else if (count < min_count) {
2126 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2128 } else if (curlen != 0) {
2129 if (curlen != prevlen) {
2130 send_code(s, curlen, s->bl_tree); count--;
2132 Assert(count >= 3 && count <= 6, " 3_6?");
2133 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2135 } else if (count <= 10) {
2136 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2139 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2141 count = 0; prevlen = curlen;
2143 max_count = 138, min_count = 3;
2144 } else if (curlen == nextlen) {
2145 max_count = 6, min_count = 3;
2147 max_count = 7, min_count = 4;
2152 /* ===========================================================================
2153 * Construct the Huffman tree for the bit lengths and return the index in
2154 * bl_order of the last bit length code to send.
2156 local int build_bl_tree(s)
2159 int max_blindex; /* index of last bit length code of non zero freq */
2161 /* Determine the bit length frequencies for literal and distance trees */
2162 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2163 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2165 /* Build the bit length tree: */
2166 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2167 /* opt_len now includes the length of the tree representations, except
2168 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2171 /* Determine the number of bit length codes to send. The pkzip format
2172 * requires that at least 4 bit length codes be sent. (appnote.txt says
2173 * 3 but the actual value used is 4.)
2175 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2176 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2178 /* Update opt_len to include the bit length tree and counts */
2179 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2180 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2181 s->opt_len, s->static_len));
2186 /* ===========================================================================
2187 * Send the header for a block using dynamic Huffman trees: the counts, the
2188 * lengths of the bit length codes, the literal tree and the distance tree.
2189 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2191 local void send_all_trees(s, lcodes, dcodes, blcodes)
2193 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2195 int rank; /* index in bl_order */
2197 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2198 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2200 Tracev((stderr, "\nbl counts: "));
2201 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2202 send_bits(s, dcodes-1, 5);
2203 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2204 for (rank = 0; rank < blcodes; rank++) {
2205 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2206 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2208 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2210 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2211 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2213 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2214 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2217 /* ===========================================================================
2218 * Send a stored block
2220 local void ct_stored_block(s, buf, stored_len, eof)
2222 charf *buf; /* input block */
2223 ulg stored_len; /* length of input block */
2224 int eof; /* true if this is the last block for a file */
2226 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2227 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2228 s->compressed_len += (stored_len + 4) << 3;
2230 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2233 /* Send just the `stored block' type code without any length bytes or data.
2235 local void ct_stored_type_only(s)
2238 send_bits(s, (STORED_BLOCK << 1), 3);
2240 s->compressed_len = (s->compressed_len + 3) & ~7L;
2244 /* ===========================================================================
2245 * Send one empty static block to give enough lookahead for inflate.
2246 * This takes 10 bits, of which 7 may remain in the bit buffer.
2247 * The current inflate code requires 9 bits of lookahead. If the EOB
2248 * code for the previous block was coded on 5 bits or less, inflate
2249 * may have only 5+3 bits of lookahead to decode this EOB.
2250 * (There are no problems if the previous block is stored or fixed.)
2252 local void ct_align(s)
2255 send_bits(s, STATIC_TREES<<1, 3);
2256 send_code(s, END_BLOCK, static_ltree);
2257 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2259 /* Of the 10 bits for the empty block, we have already sent
2260 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2261 * block was thus its length plus what we have just sent.
2263 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2264 send_bits(s, STATIC_TREES<<1, 3);
2265 send_code(s, END_BLOCK, static_ltree);
2266 s->compressed_len += 10L;
2269 s->last_eob_len = 7;
2272 /* ===========================================================================
2273 * Determine the best encoding for the current block: dynamic trees, static
2274 * trees or store, and output the encoded block to the zip file. This function
2275 * returns the total compressed length for the file so far.
2277 local ulg ct_flush_block(s, buf, stored_len, flush)
2279 charf *buf; /* input block, or NULL if too old */
2280 ulg stored_len; /* length of input block */
2281 int flush; /* Z_FINISH if this is the last block for a file */
2283 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2284 int max_blindex; /* index of last bit length code of non zero freq */
2285 int eof = flush == Z_FINISH;
2287 ++s->blocks_in_packet;
2289 /* Check if the file is ascii or binary */
2290 if (s->data_type == UNKNOWN) set_data_type(s);
2292 /* Construct the literal and distance trees */
2293 build_tree(s, (tree_desc *)(&(s->l_desc)));
2294 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2297 build_tree(s, (tree_desc *)(&(s->d_desc)));
2298 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2300 /* At this point, opt_len and static_len are the total bit lengths of
2301 * the compressed block data, excluding the tree representations.
2304 /* Build the bit length tree for the above two trees, and get the index
2305 * in bl_order of the last bit length code to send.
2307 max_blindex = build_bl_tree(s);
2309 /* Determine the best encoding. Compute first the block length in bytes */
2310 opt_lenb = (s->opt_len+3+7)>>3;
2311 static_lenb = (s->static_len+3+7)>>3;
2313 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2314 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2317 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2319 /* If compression failed and this is the first and last block,
2320 * and if the .zip file can be seeked (to rewrite the local header),
2321 * the whole file is transformed into a stored file:
2323 #ifdef STORED_FILE_OK
2324 # ifdef FORCE_STORED_FILE
2325 if (eof && compressed_len == 0L) /* force stored file */
2327 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2330 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2331 if (buf == (charf*)0) error ("block vanished");
2333 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2334 s->compressed_len = stored_len << 3;
2337 #endif /* STORED_FILE_OK */
2339 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
2340 * compression, and this block contains all the data since the last
2341 * time we used Z_PACKET_FLUSH, then just omit this block completely
2344 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
2345 && opt_lenb > stored_len - s->minCompr) {
2346 s->blocks_in_packet = 0;
2347 /* output nothing */
2351 if (buf != (char*)0) /* force stored block */
2353 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2354 /* 4: two words for the lengths */
2357 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2358 * Otherwise we can't have processed more than WSIZE input bytes since
2359 * the last block flush, because compression would have been
2360 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2361 * transform a block into a stored block.
2363 ct_stored_block(s, buf, stored_len, eof);
2367 if (static_lenb >= 0) /* force static trees */
2369 if (static_lenb == opt_lenb)
2372 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2373 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2374 s->compressed_len += 3 + s->static_len;
2376 send_bits(s, (DYN_TREES<<1)+eof, 3);
2377 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2379 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2380 s->compressed_len += 3 + s->opt_len;
2382 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2387 s->compressed_len += 7; /* align on byte boundary */
2389 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2390 s->compressed_len-7*eof));
2392 return s->compressed_len >> 3;
2395 /* ===========================================================================
2396 * Save the match info and tally the frequency counts. Return true if
2397 * the current block must be flushed.
2399 local int ct_tally (s, dist, lc)
2401 int dist; /* distance of matched string */
2402 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2404 s->d_buf[s->last_lit] = (ush)dist;
2405 s->l_buf[s->last_lit++] = (uch)lc;
2407 /* lc is the unmatched char */
2408 s->dyn_ltree[lc].Freq++;
2411 /* Here, lc is the match length - MIN_MATCH */
2412 dist--; /* dist = match distance - 1 */
2413 Assert((ush)dist < (ush)MAX_DIST(s) &&
2414 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2415 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2417 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2418 s->dyn_dtree[d_code(dist)].Freq++;
2421 /* Try to guess if it is profitable to stop the current block here */
2422 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2423 /* Compute an upper bound for the compressed length */
2424 ulg out_length = (ulg)s->last_lit*8L;
2425 ulg in_length = (ulg)s->strstart - s->block_start;
2427 for (dcode = 0; dcode < D_CODES; dcode++) {
2428 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2429 (5L+extra_dbits[dcode]);
2432 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2433 s->last_lit, in_length, out_length,
2434 100L - out_length*100L/in_length));
2435 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2437 return (s->last_lit == s->lit_bufsize-1);
2438 /* We avoid equality with lit_bufsize because of wraparound at 64K
2439 * on 16 bit machines and because stored blocks are restricted to
2444 /* ===========================================================================
2445 * Send the block data compressed using the given Huffman trees
2447 local void compress_block(s, ltree, dtree)
2449 ct_data *ltree; /* literal tree */
2450 ct_data *dtree; /* distance tree */
2452 unsigned dist; /* distance of matched string */
2453 int lc; /* match length or unmatched char (if dist == 0) */
2454 unsigned lx = 0; /* running index in l_buf */
2455 unsigned code; /* the code to send */
2456 int extra; /* number of extra bits to send */
2458 if (s->last_lit != 0) do {
2459 dist = s->d_buf[lx];
2460 lc = s->l_buf[lx++];
2462 send_code(s, lc, ltree); /* send a literal byte */
2463 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2465 /* Here, lc is the match length - MIN_MATCH */
2466 code = length_code[lc];
2467 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2468 extra = extra_lbits[code];
2470 lc -= base_length[code];
2471 send_bits(s, lc, extra); /* send the extra length bits */
2473 dist--; /* dist is now the match distance - 1 */
2474 code = d_code(dist);
2475 Assert (code < D_CODES, "bad d_code");
2477 send_code(s, code, dtree); /* send the distance code */
2478 extra = extra_dbits[code];
2480 dist -= base_dist[code];
2481 send_bits(s, dist, extra); /* send the extra distance bits */
2483 } /* literal or match pair ? */
2485 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2486 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2488 } while (lx < s->last_lit);
2490 send_code(s, END_BLOCK, ltree);
2491 s->last_eob_len = ltree[END_BLOCK].Len;
2494 /* ===========================================================================
2495 * Set the data type to ASCII or BINARY, using a crude approximation:
2496 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2497 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2498 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2500 local void set_data_type(s)
2504 unsigned ascii_freq = 0;
2505 unsigned bin_freq = 0;
2506 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2507 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2508 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2509 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2512 /* ===========================================================================
2513 * Reverse the first len bits of a code, using straightforward code (a faster
2514 * method would use a table)
2515 * IN assertion: 1 <= len <= 15
2517 local unsigned bi_reverse(code, len)
2518 unsigned code; /* the value to invert */
2519 int len; /* its bit length */
2521 register unsigned res = 0;
2524 code >>= 1, res <<= 1;
2525 } while (--len > 0);
2529 /* ===========================================================================
2530 * Flush the bit buffer, keeping at most 7 bits in it.
2532 local void bi_flush(s)
2535 if (s->bi_valid == 16) {
2536 put_short(s, s->bi_buf);
2539 } else if (s->bi_valid >= 8) {
2540 put_byte(s, (Byte)s->bi_buf);
2546 /* ===========================================================================
2547 * Flush the bit buffer and align the output on a byte boundary
2549 local void bi_windup(s)
2552 if (s->bi_valid > 8) {
2553 put_short(s, s->bi_buf);
2554 } else if (s->bi_valid > 0) {
2555 put_byte(s, (Byte)s->bi_buf);
2560 s->bits_sent = (s->bits_sent+7) & ~7;
2564 /* ===========================================================================
2565 * Copy a stored block, storing first the length and its
2566 * one's complement if requested.
2568 local void copy_block(s, buf, len, header)
2570 charf *buf; /* the input data */
2571 unsigned len; /* its length */
2572 int header; /* true if block header must be written */
2574 bi_windup(s); /* align on byte boundary */
2575 s->last_eob_len = 8; /* enough lookahead for inflate */
2578 put_short(s, (ush)len);
2579 put_short(s, (ush)~len);
2581 s->bits_sent += 2*16;
2585 s->bits_sent += (ulg)len<<3;
2588 put_byte(s, *buf++);
2594 /* infblock.h -- header to use infblock.c
2595 * Copyright (C) 1995 Mark Adler
2596 * For conditions of distribution and use, see copyright notice in zlib.h
2599 /* WARNING: this file should *not* be used by applications. It is
2600 part of the implementation of the compression library and is
2601 subject to change. Applications should only use zlib.h.
2604 struct inflate_blocks_state;
2605 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2607 local inflate_blocks_statef * inflate_blocks_new OF((
2609 check_func c, /* check function */
2610 uInt w)); /* window size */
2612 local int inflate_blocks OF((
2613 inflate_blocks_statef *,
2615 int)); /* initial return code */
2617 local void inflate_blocks_reset OF((
2618 inflate_blocks_statef *,
2620 uLongf *)); /* check value on output */
2622 local int inflate_blocks_free OF((
2623 inflate_blocks_statef *,
2625 uLongf *)); /* check value on output */
2627 local int inflate_addhistory OF((
2628 inflate_blocks_statef *,
2631 local int inflate_packet_flush OF((
2632 inflate_blocks_statef *));
2635 /* inftrees.h -- header to use inftrees.c
2636 * Copyright (C) 1995 Mark Adler
2637 * For conditions of distribution and use, see copyright notice in zlib.h
2640 /* WARNING: this file should *not* be used by applications. It is
2641 part of the implementation of the compression library and is
2642 subject to change. Applications should only use zlib.h.
2645 /* Huffman code lookup table entry--this entry is four bytes for machines
2646 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2648 typedef struct inflate_huft_s FAR inflate_huft;
2650 struct inflate_huft_s {
2653 Byte Exop; /* number of extra bits or operation */
2654 Byte Bits; /* number of bits in this code or subcode */
2656 uInt Nalloc; /* number of these allocated here */
2657 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2658 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2660 uInt Base; /* literal, length base, or distance base */
2661 inflate_huft *Next; /* pointer to next level of table */
2666 local uInt inflate_hufts;
2669 local int inflate_trees_bits OF((
2670 uIntf *, /* 19 code lengths */
2671 uIntf *, /* bits tree desired/actual depth */
2672 inflate_huft * FAR *, /* bits tree result */
2673 z_stream *)); /* for zalloc, zfree functions */
2675 local int inflate_trees_dynamic OF((
2676 uInt, /* number of literal/length codes */
2677 uInt, /* number of distance codes */
2678 uIntf *, /* that many (total) code lengths */
2679 uIntf *, /* literal desired/actual bit depth */
2680 uIntf *, /* distance desired/actual bit depth */
2681 inflate_huft * FAR *, /* literal/length tree result */
2682 inflate_huft * FAR *, /* distance tree result */
2683 z_stream *)); /* for zalloc, zfree functions */
2685 local int inflate_trees_fixed OF((
2686 uIntf *, /* literal desired/actual bit depth */
2687 uIntf *, /* distance desired/actual bit depth */
2688 inflate_huft * FAR *, /* literal/length tree result */
2689 inflate_huft * FAR *)); /* distance tree result */
2691 local int inflate_trees_free OF((
2692 inflate_huft *, /* tables to free */
2693 z_stream *)); /* for zfree function */
2697 /* infcodes.h -- header to use infcodes.c
2698 * Copyright (C) 1995 Mark Adler
2699 * For conditions of distribution and use, see copyright notice in zlib.h
2702 /* WARNING: this file should *not* be used by applications. It is
2703 part of the implementation of the compression library and is
2704 subject to change. Applications should only use zlib.h.
2707 struct inflate_codes_state;
2708 typedef struct inflate_codes_state FAR inflate_codes_statef;
2710 local inflate_codes_statef *inflate_codes_new OF((
2712 inflate_huft *, inflate_huft *,
2715 local int inflate_codes OF((
2716 inflate_blocks_statef *,
2720 local void inflate_codes_free OF((
2721 inflate_codes_statef *,
2726 /* inflate.c -- zlib interface to inflate modules
2727 * Copyright (C) 1995 Mark Adler
2728 * For conditions of distribution and use, see copyright notice in zlib.h
2731 /* inflate private state */
2732 struct internal_state {
2736 METHOD, /* waiting for method byte */
2737 FLAG, /* waiting for flag byte */
2738 BLOCKS, /* decompressing blocks */
2739 CHECK4, /* four check bytes to go */
2740 CHECK3, /* three check bytes to go */
2741 CHECK2, /* two check bytes to go */
2742 CHECK1, /* one check byte to go */
2743 DONE, /* finished check, done */
2744 BAD} /* got an error--stay here */
2745 mode; /* current inflate mode */
2747 /* mode dependent information */
2749 uInt method; /* if FLAGS, method byte */
2751 uLong was; /* computed check value */
2752 uLong need; /* stream check value */
2753 } check; /* if CHECK, check values to compare */
2754 uInt marker; /* if BAD, inflateSync's marker bytes count */
2755 } sub; /* submode */
2757 /* mode independent information */
2758 int nowrap; /* flag for no wrapper */
2759 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2760 inflate_blocks_statef
2761 *blocks; /* current inflate_blocks state */
2771 if (z == Z_NULL || z->state == Z_NULL)
2772 return Z_STREAM_ERROR;
2773 z->total_in = z->total_out = 0;
2775 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2776 inflate_blocks_reset(z->state->blocks, z, &c);
2777 Trace((stderr, "inflate: reset\n"));
2787 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2788 return Z_STREAM_ERROR;
2789 if (z->state->blocks != Z_NULL)
2790 inflate_blocks_free(z->state->blocks, z, &c);
2791 ZFREE(z, z->state, sizeof(struct internal_state));
2793 Trace((stderr, "inflate: end\n"));
2798 int inflateInit2(z, w)
2802 /* initialize state */
2804 return Z_STREAM_ERROR;
2805 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2806 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2807 if ((z->state = (struct internal_state FAR *)
2808 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2810 z->state->blocks = Z_NULL;
2812 /* handle undocumented nowrap option (no zlib header or check) */
2813 z->state->nowrap = 0;
2817 z->state->nowrap = 1;
2820 /* set window size */
2821 if (w < 8 || w > 15)
2824 return Z_STREAM_ERROR;
2826 z->state->wbits = (uInt)w;
2828 /* create inflate_blocks state */
2829 if ((z->state->blocks =
2830 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2836 Trace((stderr, "inflate: allocated\n"));
2847 return inflateInit2(z, DEF_WBITS);
2851 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2852 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2861 if (z == Z_NULL || z->next_in == Z_NULL)
2862 return Z_STREAM_ERROR;
2864 while (1) switch (z->state->mode)
2868 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2870 z->state->mode = BAD;
2871 z->msg = "unknown compression method";
2872 z->state->sub.marker = 5; /* can't try inflateSync */
2875 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2877 z->state->mode = BAD;
2878 z->msg = "invalid window size";
2879 z->state->sub.marker = 5; /* can't try inflateSync */
2882 z->state->mode = FLAG;
2885 if ((b = NEXTBYTE) & 0x20)
2887 z->state->mode = BAD;
2888 z->msg = "invalid reserved bit";
2889 z->state->sub.marker = 5; /* can't try inflateSync */
2892 if (((z->state->sub.method << 8) + b) % 31)
2894 z->state->mode = BAD;
2895 z->msg = "incorrect header check";
2896 z->state->sub.marker = 5; /* can't try inflateSync */
2899 Trace((stderr, "inflate: zlib header ok\n"));
2900 z->state->mode = BLOCKS;
2902 r = inflate_blocks(z->state->blocks, z, r);
2903 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2904 r = inflate_packet_flush(z->state->blocks);
2905 if (r == Z_DATA_ERROR)
2907 z->state->mode = BAD;
2908 z->state->sub.marker = 0; /* can try inflateSync */
2911 if (r != Z_STREAM_END)
2914 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2915 if (z->state->nowrap)
2917 z->state->mode = DONE;
2920 z->state->mode = CHECK4;
2923 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2924 z->state->mode = CHECK3;
2927 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2928 z->state->mode = CHECK2;
2931 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2932 z->state->mode = CHECK1;
2935 z->state->sub.check.need += (uLong)NEXTBYTE;
2937 if (z->state->sub.check.was != z->state->sub.check.need)
2939 z->state->mode = BAD;
2940 z->msg = "incorrect data check";
2941 z->state->sub.marker = 5; /* can't try inflateSync */
2944 Trace((stderr, "inflate: zlib check ok\n"));
2945 z->state->mode = DONE;
2947 return Z_STREAM_END;
2949 return Z_DATA_ERROR;
2951 return Z_STREAM_ERROR;
2955 if (f != Z_PACKET_FLUSH)
2957 z->state->mode = BAD;
2958 z->state->sub.marker = 0; /* can try inflateSync */
2959 return Z_DATA_ERROR;
2963 * This subroutine adds the data at next_in/avail_in to the output history
2964 * without performing any output. The output buffer must be "caught up";
2965 * i.e. no pending output (hence s->read equals s->write), and the state must
2966 * be BLOCKS (i.e. we should be willing to see the start of a series of
2967 * BLOCKS). On exit, the output will also be caught up, and the checksum
2968 * will have been updated if need be.
2971 int inflateIncomp(z)
2974 if (z->state->mode != BLOCKS)
2975 return Z_DATA_ERROR;
2976 return inflate_addhistory(z->state->blocks, z);
2983 uInt n; /* number of bytes to look at */
2984 Bytef *p; /* pointer to bytes */
2985 uInt m; /* number of marker bytes found in a row */
2986 uLong r, w; /* temporaries to save total_in and total_out */
2989 if (z == Z_NULL || z->state == Z_NULL)
2990 return Z_STREAM_ERROR;
2991 if (z->state->mode != BAD)
2993 z->state->mode = BAD;
2994 z->state->sub.marker = 0;
2996 if ((n = z->avail_in) == 0)
2999 m = z->state->sub.marker;
3004 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3014 z->total_in += p - z->next_in;
3017 z->state->sub.marker = m;
3019 /* return no joy or set up to restart on a new block */
3021 return Z_DATA_ERROR;
3022 r = z->total_in; w = z->total_out;
3024 z->total_in = r; z->total_out = w;
3025 z->state->mode = BLOCKS;
3033 /* infutil.h -- types and macros common to blocks and codes
3034 * Copyright (C) 1995 Mark Adler
3035 * For conditions of distribution and use, see copyright notice in zlib.h
3038 /* WARNING: this file should *not* be used by applications. It is
3039 part of the implementation of the compression library and is
3040 subject to change. Applications should only use zlib.h.
3043 /* inflate blocks semi-private state */
3044 struct inflate_blocks_state {
3048 TYPE, /* get type bits (3, including end bit) */
3049 LENS, /* get lengths for stored */
3050 STORED, /* processing stored block */
3051 TABLE, /* get table lengths */
3052 BTREE, /* get bit lengths tree for a dynamic block */
3053 DTREE, /* get length, distance trees for a dynamic block */
3054 CODES, /* processing fixed or dynamic block */
3055 DRY, /* output remaining window bytes */
3056 DONEB, /* finished last block, done */
3057 BADB} /* got a data error--stuck here */
3058 mode; /* current inflate_block mode */
3060 /* mode dependent information */
3062 uInt left; /* if STORED, bytes left to copy */
3064 uInt table; /* table lengths (14 bits) */
3065 uInt index; /* index into blens (or border) */
3066 uIntf *blens; /* bit lengths of codes */
3067 uInt bb; /* bit length tree depth */
3068 inflate_huft *tb; /* bit length decoding tree */
3069 int nblens; /* # elements allocated at blens */
3070 } trees; /* if DTREE, decoding info for trees */
3072 inflate_huft *tl, *td; /* trees to free */
3073 inflate_codes_statef
3075 } decode; /* if CODES, current state */
3076 } sub; /* submode */
3077 uInt last; /* true if this block is the last block */
3079 /* mode independent information */
3080 uInt bitk; /* bits in bit buffer */
3081 uLong bitb; /* bit buffer */
3082 Bytef *window; /* sliding window */
3083 Bytef *end; /* one byte after sliding window */
3084 Bytef *read; /* window read pointer */
3085 Bytef *write; /* window write pointer */
3086 check_func checkfn; /* check function */
3087 uLong check; /* check on output */
3092 /* defines for inflate input/output */
3093 /* update pointers and return */
3094 #define UPDBITS {s->bitb=b;s->bitk=k;}
3095 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3096 #define UPDOUT {s->write=q;}
3097 #define UPDATE {UPDBITS UPDIN UPDOUT}
3098 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3099 /* get bytes and bits */
3100 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3101 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3102 #define NEXTBYTE (n--,*p++)
3103 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3104 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3106 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3107 #define LOADOUT {q=s->write;m=WAVAIL;}
3108 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3109 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3110 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3111 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3112 /* load local pointers */
3113 #define LOAD {LOADIN LOADOUT}
3115 /* And'ing with mask[n] masks the lower n bits */
3116 local uInt inflate_mask[] = {
3118 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3119 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3122 /* copy as much as possible from the sliding window to the output area */
3123 local int inflate_flush OF((
3124 inflate_blocks_statef *,
3129 /* inffast.h -- header to use inffast.c
3130 * Copyright (C) 1995 Mark Adler
3131 * For conditions of distribution and use, see copyright notice in zlib.h
3134 /* WARNING: this file should *not* be used by applications. It is
3135 part of the implementation of the compression library and is
3136 subject to change. Applications should only use zlib.h.
3139 local int inflate_fast OF((
3144 inflate_blocks_statef *,
3149 /* infblock.c -- interpret and process block types to last block
3150 * Copyright (C) 1995 Mark Adler
3151 * For conditions of distribution and use, see copyright notice in zlib.h
3154 /* Table for deflate from PKZIP's appnote.txt. */
3155 local uInt border[] = { /* Order of the bit length code lengths */
3156 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3159 Notes beyond the 1.93a appnote.txt:
3161 1. Distance pointers never point before the beginning of the output
3163 2. Distance pointers can point back across blocks, up to 32k away.
3164 3. There is an implied maximum of 7 bits for the bit length table and
3165 15 bits for the actual data.
3166 4. If only one code exists, then it is encoded using one bit. (Zero
3167 would be more efficient, but perhaps a little confusing.) If two
3168 codes exist, they are coded using one bit each (0 and 1).
3169 5. There is no way of sending zero distance codes--a dummy must be
3170 sent if there are none. (History: a pre 2.0 version of PKZIP would
3171 store blocks with no distance codes, but this was discovered to be
3172 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3173 zero distance codes, which is sent as one code of zero bits in
3175 6. There are up to 286 literal/length codes. Code 256 represents the
3176 end-of-block. Note however that the static length tree defines
3177 288 codes just to fill out the Huffman codes. Codes 286 and 287
3178 cannot be used though, since there is no length base or extra bits
3179 defined for them. Similarily, there are up to 30 distance codes.
3180 However, static trees define 32 codes (all 5 bits) to fill out the
3181 Huffman codes, but the last two had better not show up in the data.
3182 7. Unzip can check dynamic Huffman blocks for complete code sets.
3183 The exception is that a single code would not be complete (see #4).
3184 8. The five bits following the block type is really the number of
3185 literal codes sent minus 257.
3186 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3187 (1+6+6). Therefore, to output three times the length, you output
3188 three codes (1+1+1), whereas to output four times the same length,
3189 you only need two codes (1+3). Hmm.
3190 10. In the tree reconstruction algorithm, Code = Code + Increment
3191 only if BitLength(i) is not zero. (Pretty obvious.)
3192 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3193 12. Note: length code 284 can represent 227-258, but length code 285
3194 really is 258. The last length deserves its own, short code
3195 since it gets used a lot in very redundant files. The length
3196 258 is special since 258 - 3 (the min match length) is 255.
3197 13. The literal/length and distance code bit lengths are read as a
3198 single stream of lengths. It is possible (and advantageous) for
3199 a repeat code (16, 17, or 18) to go across the boundary between
3200 the two sets of lengths.
3204 void inflate_blocks_reset(s, z, c)
3205 inflate_blocks_statef *s;
3209 if (s->checkfn != Z_NULL)
3211 if (s->mode == BTREE || s->mode == DTREE)
3212 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3213 if (s->mode == CODES)
3215 inflate_codes_free(s->sub.decode.codes, z);
3216 inflate_trees_free(s->sub.decode.td, z);
3217 inflate_trees_free(s->sub.decode.tl, z);
3222 s->read = s->write = s->window;
3223 if (s->checkfn != Z_NULL)
3224 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3225 Trace((stderr, "inflate: blocks reset\n"));
3229 inflate_blocks_statef *inflate_blocks_new(z, c, w)
3234 inflate_blocks_statef *s;
3236 if ((s = (inflate_blocks_statef *)ZALLOC
3237 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3239 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3241 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3244 s->end = s->window + w;
3247 Trace((stderr, "inflate: blocks allocated\n"));
3248 inflate_blocks_reset(s, z, &s->check);
3253 int inflate_blocks(s, z, r)
3254 inflate_blocks_statef *s;
3258 uInt t; /* temporary storage */
3259 uLong b; /* bit buffer */
3260 uInt k; /* bits in bit buffer */
3261 Bytef *p; /* input data pointer */
3262 uInt n; /* bytes available there */
3263 Bytef *q; /* output window write pointer */
3264 uInt m; /* bytes to end of window or read pointer */
3266 /* copy input/output information to locals (UPDATE macro restores) */
3269 /* process input based on current state */
3270 while (1) switch (s->mode)
3278 case 0: /* stored */
3279 Trace((stderr, "inflate: stored block%s\n",
3280 s->last ? " (last)" : ""));
3282 t = k & 7; /* go to byte boundary */
3284 s->mode = LENS; /* get length of stored block */
3287 Trace((stderr, "inflate: fixed codes block%s\n",
3288 s->last ? " (last)" : ""));
3291 inflate_huft *tl, *td;
3293 inflate_trees_fixed(&bl, &bd, &tl, &td);
3294 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3295 if (s->sub.decode.codes == Z_NULL)
3300 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3301 s->sub.decode.td = Z_NULL;
3306 case 2: /* dynamic */
3307 Trace((stderr, "inflate: dynamic codes block%s\n",
3308 s->last ? " (last)" : ""));
3312 case 3: /* illegal */
3315 z->msg = "invalid block type";
3322 if (((~b) >> 16) != (b & 0xffff))
3325 z->msg = "invalid stored block lengths";
3329 s->sub.left = (uInt)b & 0xffff;
3330 b = k = 0; /* dump bits */
3331 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3332 s->mode = s->sub.left ? STORED : TYPE;
3344 if ((s->sub.left -= t) != 0)
3346 Tracev((stderr, "inflate: stored end, %lu total out\n",
3347 z->total_out + (q >= s->read ? q - s->read :
3348 (s->end - s->read) + (q - s->window))));
3349 s->mode = s->last ? DRY : TYPE;
3353 s->sub.trees.table = t = (uInt)b & 0x3fff;
3354 #ifndef PKZIP_BUG_WORKAROUND
3355 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3358 z->msg = "too many length or distance symbols";
3363 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3366 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3371 s->sub.trees.nblens = t;
3373 s->sub.trees.index = 0;
3374 Tracev((stderr, "inflate: table sizes ok\n"));
3377 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3380 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3383 while (s->sub.trees.index < 19)
3384 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3385 s->sub.trees.bb = 7;
3386 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3387 &s->sub.trees.tb, z);
3391 if (r == Z_DATA_ERROR)
3395 s->sub.trees.index = 0;
3396 Tracev((stderr, "inflate: bits tree ok\n"));
3399 while (t = s->sub.trees.table,
3400 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3405 t = s->sub.trees.bb;
3407 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3408 t = h->word.what.Bits;
3413 s->sub.trees.blens[s->sub.trees.index++] = c;
3415 else /* c == 16..18 */
3417 i = c == 18 ? 7 : c - 14;
3418 j = c == 18 ? 11 : 3;
3421 j += (uInt)b & inflate_mask[i];
3423 i = s->sub.trees.index;
3424 t = s->sub.trees.table;
3425 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3429 z->msg = "invalid bit length repeat";
3433 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3435 s->sub.trees.blens[i++] = c;
3437 s->sub.trees.index = i;
3440 inflate_trees_free(s->sub.trees.tb, z);
3441 s->sub.trees.tb = Z_NULL;
3444 inflate_huft *tl, *td;
3445 inflate_codes_statef *c;
3447 bl = 9; /* must be <= 9 for lookahead assumptions */
3448 bd = 6; /* must be <= 9 for lookahead assumptions */
3449 t = s->sub.trees.table;
3450 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3451 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3454 if (t == (uInt)Z_DATA_ERROR)
3459 Tracev((stderr, "inflate: trees ok\n"));
3460 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3462 inflate_trees_free(td, z);
3463 inflate_trees_free(tl, z);
3467 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3468 s->sub.decode.codes = c;
3469 s->sub.decode.tl = tl;
3470 s->sub.decode.td = td;
3475 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3476 return inflate_flush(s, z, r);
3478 inflate_codes_free(s->sub.decode.codes, z);
3479 inflate_trees_free(s->sub.decode.td, z);
3480 inflate_trees_free(s->sub.decode.tl, z);
3482 Tracev((stderr, "inflate: codes end, %lu total out\n",
3483 z->total_out + (q >= s->read ? q - s->read :
3484 (s->end - s->read) + (q - s->window))));
3490 if (k > 7) /* return unused byte, if any */
3492 Assert(k < 16, "inflate_codes grabbed too many bytes")
3495 p--; /* can always return one */
3500 if (s->read != s->write)
3516 int inflate_blocks_free(s, z, c)
3517 inflate_blocks_statef *s;
3521 inflate_blocks_reset(s, z, c);
3522 ZFREE(z, s->window, s->end - s->window);
3523 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3524 Trace((stderr, "inflate: blocks freed\n"));
3529 * This subroutine adds the data at next_in/avail_in to the output history
3530 * without performing any output. The output buffer must be "caught up";
3531 * i.e. no pending output (hence s->read equals s->write), and the state must
3532 * be BLOCKS (i.e. we should be willing to see the start of a series of
3533 * BLOCKS). On exit, the output will also be caught up, and the checksum
3534 * will have been updated if need be.
3536 local int inflate_addhistory(s, z)
3537 inflate_blocks_statef *s;
3540 uLong b; /* bit buffer */ /* NOT USED HERE */
3541 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3542 uInt t; /* temporary storage */
3543 Bytef *p; /* input data pointer */
3544 uInt n; /* bytes available there */
3545 Bytef *q; /* output window write pointer */
3546 uInt m; /* bytes to end of window or read pointer */
3548 if (s->read != s->write)
3549 return Z_STREAM_ERROR;
3550 if (s->mode != TYPE)
3551 return Z_DATA_ERROR;
3553 /* we're ready to rock */
3555 /* while there is input ready, copy to output buffer, moving
3556 * pointers as needed.
3559 t = n; /* how many to do */
3560 /* is there room until end of buffer? */
3562 /* update check information */
3563 if (s->checkfn != Z_NULL)
3564 s->check = (*s->checkfn)(s->check, q, t);
3570 s->read = q; /* drag read pointer forward */
3571 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
3573 s->read = q = s->window;
3583 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3584 * a `stored' block type value but not the (zero) length bytes.
3586 local int inflate_packet_flush(s)
3587 inflate_blocks_statef *s;
3589 if (s->mode != LENS)
3590 return Z_DATA_ERROR;
3597 /* inftrees.c -- generate Huffman trees for efficient decoding
3598 * Copyright (C) 1995 Mark Adler
3599 * For conditions of distribution and use, see copyright notice in zlib.h
3602 /* simplify the use of the inflate_huft type with some defines */
3603 #define base more.Base
3604 #define next more.Next
3605 #define exop word.what.Exop
3606 #define bits word.what.Bits
3609 local int huft_build OF((
3610 uIntf *, /* code lengths in bits */
3611 uInt, /* number of codes */
3612 uInt, /* number of "simple" codes */
3613 uIntf *, /* list of base values for non-simple codes */
3614 uIntf *, /* list of extra bits for non-simple codes */
3615 inflate_huft * FAR*,/* result: starting table */
3616 uIntf *, /* maximum lookup bits (returns actual) */
3617 z_stream *)); /* for zalloc function */
3619 local voidpf falloc OF((
3620 voidpf, /* opaque pointer (not used) */
3621 uInt, /* number of items */
3622 uInt)); /* size of item */
3624 local void ffree OF((
3625 voidpf q, /* opaque pointer (not used) */
3626 voidpf p, /* what to free (not used) */
3627 uInt n)); /* number of bytes (not used) */
3629 /* Tables for deflate from PKZIP's appnote.txt. */
3630 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3631 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3632 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3633 /* actually lengths - 2; also see note #13 above about 258 */
3634 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3635 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3636 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3637 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3638 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3639 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3640 8193, 12289, 16385, 24577};
3641 local uInt cpdext[] = { /* Extra bits for distance codes */
3642 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3643 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3647 Huffman code decoding is performed using a multi-level table lookup.
3648 The fastest way to decode is to simply build a lookup table whose
3649 size is determined by the longest code. However, the time it takes
3650 to build this table can also be a factor if the data being decoded
3651 is not very long. The most common codes are necessarily the
3652 shortest codes, so those codes dominate the decoding time, and hence
3653 the speed. The idea is you can have a shorter table that decodes the
3654 shorter, more probable codes, and then point to subsidiary tables for
3655 the longer codes. The time it costs to decode the longer codes is
3656 then traded against the time it takes to make longer tables.
3658 This results of this trade are in the variables lbits and dbits
3659 below. lbits is the number of bits the first level table for literal/
3660 length codes can decode in one step, and dbits is the same thing for
3661 the distance codes. Subsequent tables are also less than or equal to
3662 those sizes. These values may be adjusted either when all of the
3663 codes are shorter than that, in which case the longest code length in
3664 bits is used, or when the shortest code is *longer* than the requested
3665 table size, in which case the length of the shortest code in bits is
3668 There are two different values for the two tables, since they code a
3669 different number of possibilities each. The literal/length table
3670 codes 286 possible values, or in a flat code, a little over eight
3671 bits. The distance table codes 30 possible values, or a little less
3672 than five bits, flat. The optimum values for speed end up being
3673 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3674 The optimum values may differ though from machine to machine, and
3675 possibly even between compilers. Your mileage may vary.
3679 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3680 #define BMAX 15 /* maximum bit length of any code */
3681 #define N_MAX 288 /* maximum number of codes in any set */
3687 local int huft_build(b, n, s, d, e, t, m, zs)
3688 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3689 uInt n; /* number of codes (assumed <= N_MAX) */
3690 uInt s; /* number of simple-valued codes (0..s-1) */
3691 uIntf *d; /* list of base values for non-simple codes */
3692 uIntf *e; /* list of extra bits for non-simple codes */
3693 inflate_huft * FAR *t; /* result: starting table */
3694 uIntf *m; /* maximum lookup bits, returns actual */
3695 z_stream *zs; /* for zalloc function */
3696 /* Given a list of code lengths and a maximum table size, make a set of
3697 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3698 if the given code set is incomplete (the tables are still built in this
3699 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3700 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3703 uInt a; /* counter for codes of length k */
3704 uInt c[BMAX+1]; /* bit length count table */
3705 uInt f; /* i repeats in table every f entries */
3706 int g; /* maximum code length */
3707 int h; /* table level */
3708 register uInt i; /* counter, current code */
3709 register uInt j; /* counter */
3710 register int k; /* number of bits in current code */
3711 int l; /* bits per table (returned in m) */
3712 register uIntf *p; /* pointer into c[], b[], or v[] */
3713 inflate_huft *q; /* points to current table */
3714 struct inflate_huft_s r; /* table entry for structure assignment */
3715 inflate_huft *u[BMAX]; /* table stack */
3716 uInt v[N_MAX]; /* values in order of bit length */
3717 register int w; /* bits before this table == (l * h) */
3718 uInt x[BMAX+1]; /* bit offsets, then code stack */
3719 uIntf *xp; /* pointer into x */
3720 int y; /* number of dummy codes added */
3721 uInt z; /* number of entries in current table */
3724 /* Generate counts for each bit length */
3726 #define C0 *p++ = 0;
3727 #define C2 C0 C0 C0 C0
3728 #define C4 C2 C2 C2 C2
3729 C4 /* clear c[]--assume BMAX+1 is 16 */
3732 c[*p++]++; /* assume all entries <= BMAX */
3734 if (c[0] == n) /* null input--all zero length codes */
3736 *t = (inflate_huft *)Z_NULL;
3742 /* Find minimum and maximum length, bound *m by those */
3744 for (j = 1; j <= BMAX; j++)
3747 k = j; /* minimum code length */
3750 for (i = BMAX; i; i--)
3753 g = i; /* maximum code length */
3759 /* Adjust last length count to fill out codes, if needed */
3760 for (y = 1 << j; j < i; j++, y <<= 1)
3761 if ((y -= c[j]) < 0)
3762 return Z_DATA_ERROR;
3763 if ((y -= c[i]) < 0)
3764 return Z_DATA_ERROR;
3768 /* Generate starting offsets into the value table for each length */
3770 p = c + 1; xp = x + 2;
3771 while (--i) { /* note that i == g from above */
3772 *xp++ = (j += *p++);
3776 /* Make a table of values in order of bit lengths */
3779 if ((j = *p++) != 0)
3784 /* Generate the Huffman codes and for each, make the table entries */
3785 x[0] = i = 0; /* first Huffman code is zero */
3786 p = v; /* grab values in bit order */
3787 h = -1; /* no tables yet--level -1 */
3788 w = -l; /* bits decoded == (l * h) */
3789 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3790 q = (inflate_huft *)Z_NULL; /* ditto */
3793 /* go through the bit lengths (k already is bits in shortest code) */
3799 /* here i is the Huffman code of length k bits for value *p */
3800 /* make tables up to required level */
3804 w += l; /* previous table always l bits */
3806 /* compute minimum size table less than or equal to l bits */
3807 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3808 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3809 { /* too few codes for k-w bit table */
3810 f -= a + 1; /* deduct codes from patterns left */
3813 while (++j < z) /* try smaller tables up to z bits */
3815 if ((f <<= 1) <= *++xp)
3816 break; /* enough codes to use up j bits */
3817 f -= *xp; /* else deduct codes from patterns */
3820 z = 1 << j; /* table entries for j-bit table */
3822 /* allocate and link in new table */
3823 if ((q = (inflate_huft *)ZALLOC
3824 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3827 inflate_trees_free(u[0], zs);
3828 return Z_MEM_ERROR; /* not enough memory */
3830 q->word.Nalloc = z + 1;
3832 inflate_hufts += z + 1;
3834 *t = q + 1; /* link to list for huft_free() */
3835 *(t = &(q->next)) = Z_NULL;
3836 u[h] = ++q; /* table starts after link */
3838 /* connect to last table, if there is one */
3841 x[h] = i; /* save pattern for backing up */
3842 r.bits = (Byte)l; /* bits to dump before this table */
3843 r.exop = (Byte)j; /* bits in this table */
3844 r.next = q; /* pointer to this table */
3845 j = i >> (w - l); /* (get around Turbo C bug) */
3846 u[h-1][j] = r; /* connect to last table */
3850 /* set up table entry in r */
3851 r.bits = (Byte)(k - w);
3853 r.exop = 128 + 64; /* out of values--invalid code */
3856 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3857 r.base = *p++; /* simple code is just the value */
3861 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3862 r.base = d[*p++ - s];
3865 /* fill code-like entries with r */
3867 for (j = i >> w; j < z; j += f)
3870 /* backwards increment the k-bit code i */
3871 for (j = 1 << (k - 1); i & j; j >>= 1)
3875 /* backup over finished tables */
3876 while ((i & ((1 << w) - 1)) != x[h])
3878 h--; /* don't need to update q */
3885 /* Return Z_BUF_ERROR if we were given an incomplete table */
3886 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3890 int inflate_trees_bits(c, bb, tb, z)
3891 uIntf *c; /* 19 code lengths */
3892 uIntf *bb; /* bits tree desired/actual depth */
3893 inflate_huft * FAR *tb; /* bits tree result */
3894 z_stream *z; /* for zfree function */
3898 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3899 if (r == Z_DATA_ERROR)
3900 z->msg = "oversubscribed dynamic bit lengths tree";
3901 else if (r == Z_BUF_ERROR)
3903 inflate_trees_free(*tb, z);
3904 z->msg = "incomplete dynamic bit lengths tree";
3911 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3912 uInt nl; /* number of literal/length codes */
3913 uInt nd; /* number of distance codes */
3914 uIntf *c; /* that many (total) code lengths */
3915 uIntf *bl; /* literal desired/actual bit depth */
3916 uIntf *bd; /* distance desired/actual bit depth */
3917 inflate_huft * FAR *tl; /* literal/length tree result */
3918 inflate_huft * FAR *td; /* distance tree result */
3919 z_stream *z; /* for zfree function */
3923 /* build literal/length tree */
3924 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3926 if (r == Z_DATA_ERROR)
3927 z->msg = "oversubscribed literal/length tree";
3928 else if (r == Z_BUF_ERROR)
3930 inflate_trees_free(*tl, z);
3931 z->msg = "incomplete literal/length tree";
3937 /* build distance tree */
3938 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3940 if (r == Z_DATA_ERROR)
3941 z->msg = "oversubscribed literal/length tree";
3942 else if (r == Z_BUF_ERROR) {
3943 #ifdef PKZIP_BUG_WORKAROUND
3947 inflate_trees_free(*td, z);
3948 z->msg = "incomplete literal/length tree";
3951 inflate_trees_free(*tl, z);
3961 /* build fixed tables only once--keep them here */
3962 local int fixed_lock = 0;
3963 local int fixed_built = 0;
3964 #define FIXEDH 530 /* number of hufts used by fixed tables */
3965 local uInt fixed_left = FIXEDH;
3966 local inflate_huft fixed_mem[FIXEDH];
3967 local uInt fixed_bl;
3968 local uInt fixed_bd;
3969 local inflate_huft *fixed_tl;
3970 local inflate_huft *fixed_td;
3973 local voidpf falloc(q, n, s)
3974 voidpf q; /* opaque pointer (not used) */
3975 uInt n; /* number of items */
3976 uInt s; /* size of item */
3978 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
3979 "inflate_trees falloc overflow");
3980 if (q) s++; /* to make some compilers happy */
3982 return (voidpf)(fixed_mem + fixed_left);
3986 local void ffree(q, p, n)
3991 Assert(0, "inflate_trees ffree called!");
3992 if (q) q = p; /* to make some compilers happy */
3996 int inflate_trees_fixed(bl, bd, tl, td)
3997 uIntf *bl; /* literal desired/actual bit depth */
3998 uIntf *bd; /* distance desired/actual bit depth */
3999 inflate_huft * FAR *tl; /* literal/length tree result */
4000 inflate_huft * FAR *td; /* distance tree result */
4002 /* build fixed tables if not built already--lock out other instances */
4003 while (++fixed_lock > 1)
4007 int k; /* temporary variable */
4008 unsigned c[288]; /* length list for huft_build */
4009 z_stream z; /* for falloc function */
4011 /* set up fake z_stream for memory routines */
4017 for (k = 0; k < 144; k++)
4019 for (; k < 256; k++)
4021 for (; k < 280; k++)
4023 for (; k < 288; k++)
4026 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4028 /* distance table */
4029 for (k = 0; k < 30; k++)
4032 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4046 int inflate_trees_free(t, z)
4047 inflate_huft *t; /* table to free */
4048 z_stream *z; /* for zfree function */
4049 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4050 list of the tables it made, with the links in a dummy first entry of
4053 register inflate_huft *p, *q;
4055 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4060 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4067 /* infcodes.c -- process literals and length/distance pairs
4068 * Copyright (C) 1995 Mark Adler
4069 * For conditions of distribution and use, see copyright notice in zlib.h
4072 /* simplify the use of the inflate_huft type with some defines */
4073 #define base more.Base
4074 #define next more.Next
4075 #define exop word.what.Exop
4076 #define bits word.what.Bits
4078 /* inflate codes private state */
4079 struct inflate_codes_state {
4082 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4083 START, /* x: set up for LEN */
4084 LEN, /* i: get length/literal/eob next */
4085 LENEXT, /* i: getting length extra (have base) */
4086 DIST, /* i: get distance next */
4087 DISTEXT, /* i: getting distance extra */
4088 COPY, /* o: copying bytes in window, waiting for space */
4089 LIT, /* o: got literal, waiting for output space */
4090 WASH, /* o: got eob, possibly still output waiting */
4091 END, /* x: got eob and all data flushed */
4092 BADCODE} /* x: got error */
4093 mode; /* current inflate_codes mode */
4095 /* mode dependent information */
4099 inflate_huft *tree; /* pointer into tree */
4100 uInt need; /* bits needed */
4101 } code; /* if LEN or DIST, where in tree */
4102 uInt lit; /* if LIT, literal */
4104 uInt get; /* bits to get for extra */
4105 uInt dist; /* distance back to copy from */
4106 } copy; /* if EXT or COPY, where and how much */
4107 } sub; /* submode */
4109 /* mode independent information */
4110 Byte lbits; /* ltree bits decoded per branch */
4111 Byte dbits; /* dtree bits decoder per branch */
4112 inflate_huft *ltree; /* literal/length/eob tree */
4113 inflate_huft *dtree; /* distance tree */
4118 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4120 inflate_huft *tl, *td;
4123 inflate_codes_statef *c;
4125 if ((c = (inflate_codes_statef *)
4126 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4129 c->lbits = (Byte)bl;
4130 c->dbits = (Byte)bd;
4133 Tracev((stderr, "inflate: codes new\n"));
4139 int inflate_codes(s, z, r)
4140 inflate_blocks_statef *s;
4144 uInt j; /* temporary storage */
4145 inflate_huft *t; /* temporary pointer */
4146 uInt e; /* extra bits or operation */
4147 uLong b; /* bit buffer */
4148 uInt k; /* bits in bit buffer */
4149 Bytef *p; /* input data pointer */
4150 uInt n; /* bytes available there */
4151 Bytef *q; /* output window write pointer */
4152 uInt m; /* bytes to end of window or read pointer */
4153 Bytef *f; /* pointer to copy strings from */
4154 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4156 /* copy input/output information to locals (UPDATE macro restores) */
4159 /* process input and output based on current state */
4160 while (1) switch (c->mode)
4161 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4162 case START: /* x: set up for LEN */
4164 if (m >= 258 && n >= 10)
4167 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4171 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4176 c->sub.code.need = c->lbits;
4177 c->sub.code.tree = c->ltree;
4179 case LEN: /* i: get length/literal/eob next */
4180 j = c->sub.code.need;
4182 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4184 e = (uInt)(t->exop);
4185 if (e == 0) /* literal */
4187 c->sub.lit = t->base;
4188 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4189 "inflate: literal '%c'\n" :
4190 "inflate: literal 0x%02x\n", t->base));
4194 if (e & 16) /* length */
4196 c->sub.copy.get = e & 15;
4201 if ((e & 64) == 0) /* next table */
4203 c->sub.code.need = e;
4204 c->sub.code.tree = t->next;
4207 if (e & 32) /* end of block */
4209 Tracevv((stderr, "inflate: end of block\n"));
4213 c->mode = BADCODE; /* invalid code */
4214 z->msg = "invalid literal/length code";
4217 case LENEXT: /* i: getting length extra (have base) */
4218 j = c->sub.copy.get;
4220 c->len += (uInt)b & inflate_mask[j];
4222 c->sub.code.need = c->dbits;
4223 c->sub.code.tree = c->dtree;
4224 Tracevv((stderr, "inflate: length %u\n", c->len));
4226 case DIST: /* i: get distance next */
4227 j = c->sub.code.need;
4229 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4231 e = (uInt)(t->exop);
4232 if (e & 16) /* distance */
4234 c->sub.copy.get = e & 15;
4235 c->sub.copy.dist = t->base;
4239 if ((e & 64) == 0) /* next table */
4241 c->sub.code.need = e;
4242 c->sub.code.tree = t->next;
4245 c->mode = BADCODE; /* invalid code */
4246 z->msg = "invalid distance code";
4249 case DISTEXT: /* i: getting distance extra */
4250 j = c->sub.copy.get;
4252 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4254 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4256 case COPY: /* o: copying bytes in window, waiting for space */
4257 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4258 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4259 s->end - (c->sub.copy.dist - (q - s->window)) :
4260 q - c->sub.copy.dist;
4262 f = q - c->sub.copy.dist;
4263 if ((uInt)(q - s->window) < c->sub.copy.dist)
4264 f = s->end - (c->sub.copy.dist - (q - s->window));
4276 case LIT: /* o: got literal, waiting for output space */
4281 case WASH: /* o: got eob, possibly more output */
4283 if (s->read != s->write)
4289 case BADCODE: /* x: got error */
4299 void inflate_codes_free(c, z)
4300 inflate_codes_statef *c;
4303 ZFREE(z, c, sizeof(struct inflate_codes_state));
4304 Tracev((stderr, "inflate: codes free\n"));
4308 /* inflate_util.c -- data and routines common to blocks and codes
4309 * Copyright (C) 1995 Mark Adler
4310 * For conditions of distribution and use, see copyright notice in zlib.h
4313 /* copy as much as possible from the sliding window to the output area */
4314 int inflate_flush(s, z, r)
4315 inflate_blocks_statef *s;
4322 /* local copies of source and destination pointers */
4326 /* compute number of bytes to copy as far as end of window */
4327 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4328 if (n > z->avail_out) n = z->avail_out;
4329 if (n && r == Z_BUF_ERROR) r = Z_OK;
4331 /* update counters */
4335 /* update check information */
4336 if (s->checkfn != Z_NULL)
4337 s->check = (*s->checkfn)(s->check, q, n);
4339 /* copy as far as end of window */
4346 /* see if more to copy at beginning of window */
4351 if (s->write == s->end)
4352 s->write = s->window;
4354 /* compute bytes to copy */
4355 n = (uInt)(s->write - q);
4356 if (n > z->avail_out) n = z->avail_out;
4357 if (n && r == Z_BUF_ERROR) r = Z_OK;
4359 /* update counters */
4363 /* update check information */
4364 if (s->checkfn != Z_NULL)
4365 s->check = (*s->checkfn)(s->check, q, n);
4375 /* update pointers */
4385 /* inffast.c -- process literals and length/distance pairs fast
4386 * Copyright (C) 1995 Mark Adler
4387 * For conditions of distribution and use, see copyright notice in zlib.h
4390 /* simplify the use of the inflate_huft type with some defines */
4391 #define base more.Base
4392 #define next more.Next
4393 #define exop word.what.Exop
4394 #define bits word.what.Bits
4396 /* macros for bit input with no checking and for returning unused bytes */
4397 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4398 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4400 /* Called with number of bytes left to write in window at least 258
4401 (the maximum string length) and number of input bytes available
4402 at least ten. The ten bytes are six bytes for the longest length/
4403 distance pair plus four bytes for overloading the bit buffer. */
4405 int inflate_fast(bl, bd, tl, td, s, z)
4407 inflate_huft *tl, *td;
4408 inflate_blocks_statef *s;
4411 inflate_huft *t; /* temporary pointer */
4412 uInt e; /* extra bits or operation */
4413 uLong b; /* bit buffer */
4414 uInt k; /* bits in bit buffer */
4415 Bytef *p; /* input data pointer */
4416 uInt n; /* bytes available there */
4417 Bytef *q; /* output window write pointer */
4418 uInt m; /* bytes to end of window or read pointer */
4419 uInt ml; /* mask for literal/length tree */
4420 uInt md; /* mask for distance tree */
4421 uInt c; /* bytes to copy */
4422 uInt d; /* distance back to copy from */
4423 Bytef *r; /* copy source pointer */
4425 /* load input, output, bit values */
4428 /* initialize masks */
4429 ml = inflate_mask[bl];
4430 md = inflate_mask[bd];
4432 /* do until not enough input or output space for fast loop */
4433 do { /* assume called with m >= 258 && n >= 10 */
4434 /* get literal/length code */
4435 GRABBITS(20) /* max bits for literal/length code */
4436 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4439 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4440 "inflate: * literal '%c'\n" :
4441 "inflate: * literal 0x%02x\n", t->base));
4442 *q++ = (Byte)t->base;
4450 /* get extra bits for length */
4452 c = t->base + ((uInt)b & inflate_mask[e]);
4454 Tracevv((stderr, "inflate: * length %u\n", c));
4456 /* decode distance base of block to copy */
4457 GRABBITS(15); /* max bits for distance code */
4458 e = (t = td + ((uInt)b & md))->exop;
4463 /* get extra bits to add to distance base */
4465 GRABBITS(e) /* get extra bits (up to 13) */
4466 d = t->base + ((uInt)b & inflate_mask[e]);
4468 Tracevv((stderr, "inflate: * distance %u\n", d));
4472 if ((uInt)(q - s->window) >= d) /* offset before dest */
4475 *q++ = *r++; c--; /* minimum count is three, */
4476 *q++ = *r++; c--; /* so unroll loop a little */
4478 else /* else offset after destination */
4480 e = d - (q - s->window); /* bytes from offset to end */
4481 r = s->end - e; /* pointer to offset */
4482 if (c > e) /* if source crosses, */
4484 c -= e; /* copy to end of window */
4488 r = s->window; /* copy rest from start of window */
4491 do { /* copy all or what's left */
4496 else if ((e & 64) == 0)
4497 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4500 z->msg = "invalid distance code";
4503 return Z_DATA_ERROR;
4510 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4513 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4514 "inflate: * literal '%c'\n" :
4515 "inflate: * literal 0x%02x\n", t->base));
4516 *q++ = (Byte)t->base;
4523 Tracevv((stderr, "inflate: * end of block\n"));
4526 return Z_STREAM_END;
4530 z->msg = "invalid literal/length code";
4533 return Z_DATA_ERROR;
4536 } while (m >= 258 && n >= 10);
4538 /* not enough input or output--restore pointers and return */
4546 /* zutil.c -- target dependent utility functions for the compression library
4547 * Copyright (C) 1995 Jean-loup Gailly.
4548 * For conditions of distribution and use, see copyright notice in zlib.h
4551 /* $Id: zlib.c,v 1.1 1996/01/18 03:26:49 paulus Exp $ */
4553 char *zlib_version = ZLIB_VERSION;
4555 char *z_errmsg[] = {
4556 "stream end", /* Z_STREAM_END 1 */
4558 "file error", /* Z_ERRNO (-1) */
4559 "stream error", /* Z_STREAM_ERROR (-2) */
4560 "data error", /* Z_DATA_ERROR (-3) */
4561 "insufficient memory", /* Z_MEM_ERROR (-4) */
4562 "buffer error", /* Z_BUF_ERROR (-5) */
4567 /* adler32.c -- compute the Adler-32 checksum of a data stream
4568 * Copyright (C) 1995 Mark Adler
4569 * For conditions of distribution and use, see copyright notice in zlib.h
4572 /* $Id: zlib.c,v 1.1 1996/01/18 03:26:49 paulus Exp $ */
4574 #define BASE 65521L /* largest prime smaller than 65536 */
4576 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4578 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4579 #define DO2(buf) DO1(buf); DO1(buf);
4580 #define DO4(buf) DO2(buf); DO2(buf);
4581 #define DO8(buf) DO4(buf); DO4(buf);
4582 #define DO16(buf) DO8(buf); DO8(buf);
4584 /* ========================================================================= */
4585 uLong adler32(adler, buf, len)
4590 unsigned long s1 = adler & 0xffff;
4591 unsigned long s2 = (adler >> 16) & 0xffff;
4594 if (buf == Z_NULL) return 1L;
4597 k = len < NMAX ? len : NMAX;
4609 return (s2 << 16) | s1;