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trees.c
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1 /* trees.c -- output deflated data using Huffman coding
2 * Copyright (C) 1995-2010 Jean-loup Gailly
3 * detect_data_type() function provided freely by Cosmin Truta, 2006
4 * For conditions of distribution and use, see copyright notice in zlib.h
5 */
6
7 /*
8 * ALGORITHM
9 *
10 * The "deflation" process uses several Huffman trees. The more
11 * common source values are represented by shorter bit sequences.
12 *
13 * Each code tree is stored in a compressed form which is itself
14 * a Huffman encoding of the lengths of all the code strings (in
15 * ascending order by source values). The actual code strings are
16 * reconstructed from the lengths in the inflate process, as described
17 * in the deflate specification.
18 *
19 * REFERENCES
20 *
21 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
22 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
23 *
24 * Storer, James A.
25 * Data Compression: Methods and Theory, pp. 49-50.
26 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
27 *
28 * Sedgewick, R.
29 * Algorithms, p290.
30 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
31 */
32
33 /* @(#) $Id$ */
34
35 /* #define GEN_TREES_H */
36
37 #include "deflate.h"
38
39 #ifdef DEBUG
40 # include <ctype.h>
41 #endif
42
43 /* ===========================================================================
44 * Constants
45 */
46
47 #define MAX_BL_BITS 7
48 /* Bit length codes must not exceed MAX_BL_BITS bits */
49
50 #define END_BLOCK 256
51 /* end of block literal code */
52
53 #define REP_3_6 16
54 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
55
56 #define REPZ_3_10 17
57 /* repeat a zero length 3-10 times (3 bits of repeat count) */
58
59 #define REPZ_11_138 18
60 /* repeat a zero length 11-138 times (7 bits of repeat count) */
61
62 local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
63 = {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};
64
65 local const int extra_dbits[D_CODES] /* extra bits for each distance code */
66 = {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};
67
68 local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
69 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
70
71 local const uch bl_order[BL_CODES]
72 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
73 /* The lengths of the bit length codes are sent in order of decreasing
74 * probability, to avoid transmitting the lengths for unused bit length codes.
75 */
76
77 #define Buf_size (8 * 2*sizeof(char))
78 /* Number of bits used within bi_buf. (bi_buf might be implemented on
79 * more than 16 bits on some systems.)
80 */
81
82 /* ===========================================================================
83 * Local data. These are initialized only once.
84 */
85
86 #define DIST_CODE_LEN 512 /* see definition of array dist_code below */
87
88 #if defined(GEN_TREES_H) || !defined(STDC)
89 /* non ANSI compilers may not accept trees.h */
90
91 local ct_data static_ltree[L_CODES+2];
92 /* The static literal tree. Since the bit lengths are imposed, there is no
93 * need for the L_CODES extra codes used during heap construction. However
94 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
95 * below).
96 */
97
98 local ct_data static_dtree[D_CODES];
99 /* The static distance tree. (Actually a trivial tree since all codes use
100 * 5 bits.)
101 */
102
103 uch _dist_code[DIST_CODE_LEN];
104 /* Distance codes. The first 256 values correspond to the distances
105 * 3 .. 258, the last 256 values correspond to the top 8 bits of
106 * the 15 bit distances.
107 */
108
109 uch _length_code[MAX_MATCH-MIN_MATCH+1];
110 /* length code for each normalized match length (0 == MIN_MATCH) */
111
112 local int base_length[LENGTH_CODES];
113 /* First normalized length for each code (0 = MIN_MATCH) */
114
115 local int base_dist[D_CODES];
116 /* First normalized distance for each code (0 = distance of 1) */
117
118 #else
119 # include "trees.h"
120 #endif /* GEN_TREES_H */
121
122 struct static_tree_desc_s {
123 const ct_data *static_tree; /* static tree or NULL */
124 const intf *extra_bits; /* extra bits for each code or NULL */
125 int extra_base; /* base index for extra_bits */
126 int elems; /* max number of elements in the tree */
127 int max_length; /* max bit length for the codes */
128 };
129
130 local static_tree_desc static_l_desc =
131 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
132
133 local static_tree_desc static_d_desc =
134 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
135
136 local static_tree_desc static_bl_desc =
137 {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
138
139 /* ===========================================================================
140 * Local (static) routines in this file.
141 */
142
143 local void tr_static_init OF((void));
144 local void init_block OF((deflate_state *s));
145 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
146 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
147 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
148 local void build_tree OF((deflate_state *s, tree_desc *desc));
149 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
150 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
151 local int build_bl_tree OF((deflate_state *s));
152 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
153 int blcodes));
154 local void compress_block OF((deflate_state *s, ct_data *ltree,
155 ct_data *dtree));
156 local int detect_data_type OF((deflate_state *s));
157 local unsigned bi_reverse OF((unsigned value, int length));
158 local void bi_windup OF((deflate_state *s));
159 local void bi_flush OF((deflate_state *s));
160 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
161 int header));
162
163 #ifdef GEN_TREES_H
164 local void gen_trees_header OF((void));
165 #endif
166
167 #ifndef DEBUG
168 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
169 /* Send a code of the given tree. c and tree must not have side effects */
170
171 #else /* DEBUG */
172 # define send_code(s, c, tree) \
173 { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
174 send_bits(s, tree[c].Code, tree[c].Len); }
175 #endif
176
177 /* ===========================================================================
178 * Output a short LSB first on the stream.
179 * IN assertion: there is enough room in pendingBuf.
180 */
181 #define put_short(s, w) { \
182 put_byte(s, (uch)((w) & 0xff)); \
183 put_byte(s, (uch)((ush)(w) >> 8)); \
184 }
185
186 /* ===========================================================================
187 * Send a value on a given number of bits.
188 * IN assertion: length <= 16 and value fits in length bits.
189 */
190 #ifdef DEBUG
191 local void send_bits OF((deflate_state *s, int value, int length));
192
193 local void send_bits(s, value, length)
194 deflate_state *s;
195 int value; /* value to send */
196 int length; /* number of bits */
197 {
198 Tracevv((stderr," l %2d v %4x ", length, value));
199 Assert(length > 0 && length <= 15, "invalid length");
200 s->bits_sent += (ulg)length;
201
202 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
203 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
204 * unused bits in value.
205 */
206 if (s->bi_valid > (int)Buf_size - length) {
207 s->bi_buf |= (ush)value << s->bi_valid;
208 put_short(s, s->bi_buf);
209 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
210 s->bi_valid += length - Buf_size;
211 } else {
212 s->bi_buf |= (ush)value << s->bi_valid;
213 s->bi_valid += length;
214 }
215 }
216 #else /* !DEBUG */
217
218 #define send_bits(s, value, length) \
219 { int len = length;\
220 if (s->bi_valid > (int)Buf_size - len) {\
221 int val = value;\
222 s->bi_buf |= (ush)val << s->bi_valid;\
223 put_short(s, s->bi_buf);\
224 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
225 s->bi_valid += len - Buf_size;\
226 } else {\
227 s->bi_buf |= (ush)(value) << s->bi_valid;\
228 s->bi_valid += len;\
229 }\
230 }
231 #endif /* DEBUG */
232
233
234 /* the arguments must not have side effects */
235
236 /* ===========================================================================
237 * Initialize the various 'constant' tables.
238 */
239 local void tr_static_init()
240 {
241 #if defined(GEN_TREES_H) || !defined(STDC)
242 static int static_init_done = 0;
243 int n; /* iterates over tree elements */
244 int bits; /* bit counter */
245 int length; /* length value */
246 int code; /* code value */
247 int dist; /* distance index */
248 ush bl_count[MAX_BITS+1];
249 /* number of codes at each bit length for an optimal tree */
250
251 if (static_init_done) return;
252
253 /* For some embedded targets, global variables are not initialized: */
254 #ifdef NO_INIT_GLOBAL_POINTERS
255 static_l_desc.static_tree = static_ltree;
256 static_l_desc.extra_bits = extra_lbits;
257 static_d_desc.static_tree = static_dtree;
258 static_d_desc.extra_bits = extra_dbits;
259 static_bl_desc.extra_bits = extra_blbits;
260 #endif
261
262 /* Initialize the mapping length (0..255) -> length code (0..28) */
263 length = 0;
264 for (code = 0; code < LENGTH_CODES-1; code++) {
265 base_length[code] = length;
266 for (n = 0; n < (1<<extra_lbits[code]); n++) {
267 _length_code[length++] = (uch)code;
268 }
269 }
270 Assert (length == 256, "tr_static_init: length != 256");
271 /* Note that the length 255 (match length 258) can be represented
272 * in two different ways: code 284 + 5 bits or code 285, so we
273 * overwrite length_code[255] to use the best encoding:
274 */
275 _length_code[length-1] = (uch)code;
276
277 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
278 dist = 0;
279 for (code = 0 ; code < 16; code++) {
280 base_dist[code] = dist;
281 for (n = 0; n < (1<<extra_dbits[code]); n++) {
282 _dist_code[dist++] = (uch)code;
283 }
284 }
285 Assert (dist == 256, "tr_static_init: dist != 256");
286 dist >>= 7; /* from now on, all distances are divided by 128 */
287 for ( ; code < D_CODES; code++) {
288 base_dist[code] = dist << 7;
289 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
290 _dist_code[256 + dist++] = (uch)code;
291 }
292 }
293 Assert (dist == 256, "tr_static_init: 256+dist != 512");
294
295 /* Construct the codes of the static literal tree */
296 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
297 n = 0;
298 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
299 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
300 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
301 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
302 /* Codes 286 and 287 do not exist, but we must include them in the
303 * tree construction to get a canonical Huffman tree (longest code
304 * all ones)
305 */
306 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
307
308 /* The static distance tree is trivial: */
309 for (n = 0; n < D_CODES; n++) {
310 static_dtree[n].Len = 5;
311 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
312 }
313 static_init_done = 1;
314
315 # ifdef GEN_TREES_H
316 gen_trees_header();
317 # endif
318 #endif /* defined(GEN_TREES_H) || !defined(STDC) */
319 }
320
321 /* ===========================================================================
322 * Genererate the file trees.h describing the static trees.
323 */
324 #ifdef GEN_TREES_H
325 # ifndef DEBUG
326 # include <stdio.h>
327 # endif
328
329 # define SEPARATOR(i, last, width) \
330 ((i) == (last)? "\n};\n\n" : \
331 ((i) % (width) == (width)-1 ? ",\n" : ", "))
332
333 void gen_trees_header()
334 {
335 FILE *header = fopen("trees.h", "w");
336 int i;
337
338 Assert (header != NULL, "Can't open trees.h");
339 fprintf(header,
340 "/* header created automatically with -DGEN_TREES_H */\n\n");
341
342 fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
343 for (i = 0; i < L_CODES+2; i++) {
344 fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
345 static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
346 }
347
348 fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
349 for (i = 0; i < D_CODES; i++) {
350 fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
351 static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
352 }
353
354 fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");
355 for (i = 0; i < DIST_CODE_LEN; i++) {
356 fprintf(header, "%2u%s", _dist_code[i],
357 SEPARATOR(i, DIST_CODE_LEN-1, 20));
358 }
359
360 fprintf(header,
361 "const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
362 for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
363 fprintf(header, "%2u%s", _length_code[i],
364 SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
365 }
366
367 fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
368 for (i = 0; i < LENGTH_CODES; i++) {
369 fprintf(header, "%1u%s", base_length[i],
370 SEPARATOR(i, LENGTH_CODES-1, 20));
371 }
372
373 fprintf(header, "local const int base_dist[D_CODES] = {\n");
374 for (i = 0; i < D_CODES; i++) {
375 fprintf(header, "%5u%s", base_dist[i],
376 SEPARATOR(i, D_CODES-1, 10));
377 }
378
379 fclose(header);
380 }
381 #endif /* GEN_TREES_H */
382
383 /* ===========================================================================
384 * Initialize the tree data structures for a new zlib stream.
385 */
386 void ZLIB_INTERNAL _tr_init(s)
387 deflate_state *s;
388 {
389 tr_static_init();
390
391 s->l_desc.dyn_tree = s->dyn_ltree;
392 s->l_desc.stat_desc = &static_l_desc;
393
394 s->d_desc.dyn_tree = s->dyn_dtree;
395 s->d_desc.stat_desc = &static_d_desc;
396
397 s->bl_desc.dyn_tree = s->bl_tree;
398 s->bl_desc.stat_desc = &static_bl_desc;
399
400 s->bi_buf = 0;
401 s->bi_valid = 0;
402 s->last_eob_len = 8; /* enough lookahead for inflate */
403 #ifdef DEBUG
404 s->compressed_len = 0L;
405 s->bits_sent = 0L;
406 #endif
407
408 /* Initialize the first block of the first file: */
409 init_block(s);
410 }
411
412 /* ===========================================================================
413 * Initialize a new block.
414 */
415 local void init_block(s)
416 deflate_state *s;
417 {
418 int n; /* iterates over tree elements */
419
420 /* Initialize the trees. */
421 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
422 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
423 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
424
425 s->dyn_ltree[END_BLOCK].Freq = 1;
426 s->opt_len = s->static_len = 0L;
427 s->last_lit = s->matches = 0;
428 }
429
430 #define SMALLEST 1
431 /* Index within the heap array of least frequent node in the Huffman tree */
432
433
434 /* ===========================================================================
435 * Remove the smallest element from the heap and recreate the heap with
436 * one less element. Updates heap and heap_len.
437 */
438 #define pqremove(s, tree, top) \
439 {\
440 top = s->heap[SMALLEST]; \
441 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
442 pqdownheap(s, tree, SMALLEST); \
443 }
444
445 /* ===========================================================================
446 * Compares to subtrees, using the tree depth as tie breaker when
447 * the subtrees have equal frequency. This minimizes the worst case length.
448 */
449 #define smaller(tree, n, m, depth) \
450 (tree[n].Freq < tree[m].Freq || \
451 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
452
453 /* ===========================================================================
454 * Restore the heap property by moving down the tree starting at node k,
455 * exchanging a node with the smallest of its two sons if necessary, stopping
456 * when the heap property is re-established (each father smaller than its
457 * two sons).
458 */
459 local void pqdownheap(s, tree, k)
460 deflate_state *s;
461 ct_data *tree; /* the tree to restore */
462 int k; /* node to move down */
463 {
464 int v = s->heap[k];
465 int j = k << 1; /* left son of k */
466 while (j <= s->heap_len) {
467 /* Set j to the smallest of the two sons: */
468 if (j < s->heap_len &&
469 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
470 j++;
471 }
472 /* Exit if v is smaller than both sons */
473 if (smaller(tree, v, s->heap[j], s->depth)) break;
474
475 /* Exchange v with the smallest son */
476 s->heap[k] = s->heap[j]; k = j;
477
478 /* And continue down the tree, setting j to the left son of k */
479 j <<= 1;
480 }
481 s->heap[k] = v;
482 }
483
484 /* ===========================================================================
485 * Compute the optimal bit lengths for a tree and update the total bit length
486 * for the current block.
487 * IN assertion: the fields freq and dad are set, heap[heap_max] and
488 * above are the tree nodes sorted by increasing frequency.
489 * OUT assertions: the field len is set to the optimal bit length, the
490 * array bl_count contains the frequencies for each bit length.
491 * The length opt_len is updated; static_len is also updated if stree is
492 * not null.
493 */
494 local void gen_bitlen(s, desc)
495 deflate_state *s;
496 tree_desc *desc; /* the tree descriptor */
497 {
498 ct_data *tree = desc->dyn_tree;
499 int max_code = desc->max_code;
500 const ct_data *stree = desc->stat_desc->static_tree;
501 const intf *extra = desc->stat_desc->extra_bits;
502 int base = desc->stat_desc->extra_base;
503 int max_length = desc->stat_desc->max_length;
504 int h; /* heap index */
505 int n, m; /* iterate over the tree elements */
506 int bits; /* bit length */
507 int xbits; /* extra bits */
508 ush f; /* frequency */
509 int overflow = 0; /* number of elements with bit length too large */
510
511 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
512
513 /* In a first pass, compute the optimal bit lengths (which may
514 * overflow in the case of the bit length tree).
515 */
516 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
517
518 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
519 n = s->heap[h];
520 bits = tree[tree[n].Dad].Len + 1;
521 if (bits > max_length) bits = max_length, overflow++;
522 tree[n].Len = (ush)bits;
523 /* We overwrite tree[n].Dad which is no longer needed */
524
525 if (n > max_code) continue; /* not a leaf node */
526
527 s->bl_count[bits]++;
528 xbits = 0;
529 if (n >= base) xbits = extra[n-base];
530 f = tree[n].Freq;
531 s->opt_len += (ulg)f * (bits + xbits);
532 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
533 }
534 if (overflow == 0) return;
535
536 Trace((stderr,"\nbit length overflow\n"));
537 /* This happens for example on obj2 and pic of the Calgary corpus */
538
539 /* Find the first bit length which could increase: */
540 do {
541 bits = max_length-1;
542 while (s->bl_count[bits] == 0) bits--;
543 s->bl_count[bits]--; /* move one leaf down the tree */
544 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
545 s->bl_count[max_length]--;
546 /* The brother of the overflow item also moves one step up,
547 * but this does not affect bl_count[max_length]
548 */
549 overflow -= 2;
550 } while (overflow > 0);
551
552 /* Now recompute all bit lengths, scanning in increasing frequency.
553 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
554 * lengths instead of fixing only the wrong ones. This idea is taken
555 * from 'ar' written by Haruhiko Okumura.)
556 */
557 for (bits = max_length; bits != 0; bits--) {
558 n = s->bl_count[bits];
559 while (n != 0) {
560 m = s->heap[--h];
561 if (m > max_code) continue;
562 if ((unsigned) tree[m].Len != (unsigned) bits) {
563 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
564 s->opt_len += ((long)bits - (long)tree[m].Len)
565 *(long)tree[m].Freq;
566 tree[m].Len = (ush)bits;
567 }
568 n--;
569 }
570 }
571 }
572
573 /* ===========================================================================
574 * Generate the codes for a given tree and bit counts (which need not be
575 * optimal).
576 * IN assertion: the array bl_count contains the bit length statistics for
577 * the given tree and the field len is set for all tree elements.
578 * OUT assertion: the field code is set for all tree elements of non
579 * zero code length.
580 */
581 local void gen_codes (tree, max_code, bl_count)
582 ct_data *tree; /* the tree to decorate */
583 int max_code; /* largest code with non zero frequency */
584 ushf *bl_count; /* number of codes at each bit length */
585 {
586 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
587 ush code = 0; /* running code value */
588 int bits; /* bit index */
589 int n; /* code index */
590
591 /* The distribution counts are first used to generate the code values
592 * without bit reversal.
593 */
594 for (bits = 1; bits <= MAX_BITS; bits++) {
595 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
596 }
597 /* Check that the bit counts in bl_count are consistent. The last code
598 * must be all ones.
599 */
600 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
601 "inconsistent bit counts");
602 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
603
604 for (n = 0; n <= max_code; n++) {
605 int len = tree[n].Len;
606 if (len == 0) continue;
607 /* Now reverse the bits */
608 tree[n].Code = bi_reverse(next_code[len]++, len);
609
610 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
611 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
612 }
613 }
614
615 /* ===========================================================================
616 * Construct one Huffman tree and assigns the code bit strings and lengths.
617 * Update the total bit length for the current block.
618 * IN assertion: the field freq is set for all tree elements.
619 * OUT assertions: the fields len and code are set to the optimal bit length
620 * and corresponding code. The length opt_len is updated; static_len is
621 * also updated if stree is not null. The field max_code is set.
622 */
623 local void build_tree(s, desc)
624 deflate_state *s;
625 tree_desc *desc; /* the tree descriptor */
626 {
627 ct_data *tree = desc->dyn_tree;
628 const ct_data *stree = desc->stat_desc->static_tree;
629 int elems = desc->stat_desc->elems;
630 int n, m; /* iterate over heap elements */
631 int max_code = -1; /* largest code with non zero frequency */
632 int node; /* new node being created */
633
634 /* Construct the initial heap, with least frequent element in
635 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
636 * heap[0] is not used.
637 */
638 s->heap_len = 0, s->heap_max = HEAP_SIZE;
639
640 for (n = 0; n < elems; n++) {
641 if (tree[n].Freq != 0) {
642 s->heap[++(s->heap_len)] = max_code = n;
643 s->depth[n] = 0;
644 } else {
645 tree[n].Len = 0;
646 }
647 }
648
649 /* The pkzip format requires that at least one distance code exists,
650 * and that at least one bit should be sent even if there is only one
651 * possible code. So to avoid special checks later on we force at least
652 * two codes of non zero frequency.
653 */
654 while (s->heap_len < 2) {
655 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
656 tree[node].Freq = 1;
657 s->depth[node] = 0;
658 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
659 /* node is 0 or 1 so it does not have extra bits */
660 }
661 desc->max_code = max_code;
662
663 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
664 * establish sub-heaps of increasing lengths:
665 */
666 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
667
668 /* Construct the Huffman tree by repeatedly combining the least two
669 * frequent nodes.
670 */
671 node = elems; /* next internal node of the tree */
672 do {
673 pqremove(s, tree, n); /* n = node of least frequency */
674 m = s->heap[SMALLEST]; /* m = node of next least frequency */
675
676 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
677 s->heap[--(s->heap_max)] = m;
678
679 /* Create a new node father of n and m */
680 tree[node].Freq = tree[n].Freq + tree[m].Freq;
681 s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?
682 s->depth[n] : s->depth[m]) + 1);
683 tree[n].Dad = tree[m].Dad = (ush)node;
684 #ifdef DUMP_BL_TREE
685 if (tree == s->bl_tree) {
686 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
687 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
688 }
689 #endif
690 /* and insert the new node in the heap */
691 s->heap[SMALLEST] = node++;
692 pqdownheap(s, tree, SMALLEST);
693
694 } while (s->heap_len >= 2);
695
696 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
697
698 /* At this point, the fields freq and dad are set. We can now
699 * generate the bit lengths.
700 */
701 gen_bitlen(s, (tree_desc *)desc);
702
703 /* The field len is now set, we can generate the bit codes */
704 gen_codes ((ct_data *)tree, max_code, s->bl_count);
705 }
706
707 /* ===========================================================================
708 * Scan a literal or distance tree to determine the frequencies of the codes
709 * in the bit length tree.
710 */
711 local void scan_tree (s, tree, max_code)
712 deflate_state *s;
713 ct_data *tree; /* the tree to be scanned */
714 int max_code; /* and its largest code of non zero frequency */
715 {
716 int n; /* iterates over all tree elements */
717 int prevlen = -1; /* last emitted length */
718 int curlen; /* length of current code */
719 int nextlen = tree[0].Len; /* length of next code */
720 int count = 0; /* repeat count of the current code */
721 int max_count = 7; /* max repeat count */
722 int min_count = 4; /* min repeat count */
723
724 if (nextlen == 0) max_count = 138, min_count = 3;
725 tree[max_code+1].Len = (ush)0xffff; /* guard */
726
727 for (n = 0; n <= max_code; n++) {
728 curlen = nextlen; nextlen = tree[n+1].Len;
729 if (++count < max_count && curlen == nextlen) {
730 continue;
731 } else if (count < min_count) {
732 s->bl_tree[curlen].Freq += count;
733 } else if (curlen != 0) {
734 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
735 s->bl_tree[REP_3_6].Freq++;
736 } else if (count <= 10) {
737 s->bl_tree[REPZ_3_10].Freq++;
738 } else {
739 s->bl_tree[REPZ_11_138].Freq++;
740 }
741 count = 0; prevlen = curlen;
742 if (nextlen == 0) {
743 max_count = 138, min_count = 3;
744 } else if (curlen == nextlen) {
745 max_count = 6, min_count = 3;
746 } else {
747 max_count = 7, min_count = 4;
748 }
749 }
750 }
751
752 /* ===========================================================================
753 * Send a literal or distance tree in compressed form, using the codes in
754 * bl_tree.
755 */
756 local void send_tree (s, tree, max_code)
757 deflate_state *s;
758 ct_data *tree; /* the tree to be scanned */
759 int max_code; /* and its largest code of non zero frequency */
760 {
761 int n; /* iterates over all tree elements */
762 int prevlen = -1; /* last emitted length */
763 int curlen; /* length of current code */
764 int nextlen = tree[0].Len; /* length of next code */
765 int count = 0; /* repeat count of the current code */
766 int max_count = 7; /* max repeat count */
767 int min_count = 4; /* min repeat count */
768
769 /* tree[max_code+1].Len = -1; */ /* guard already set */
770 if (nextlen == 0) max_count = 138, min_count = 3;
771
772 for (n = 0; n <= max_code; n++) {
773 curlen = nextlen; nextlen = tree[n+1].Len;
774 if (++count < max_count && curlen == nextlen) {
775 continue;
776 } else if (count < min_count) {
777 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
778
779 } else if (curlen != 0) {
780 if (curlen != prevlen) {
781 send_code(s, curlen, s->bl_tree); count--;
782 }
783 Assert(count >= 3 && count <= 6, " 3_6?");
784 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
785
786 } else if (count <= 10) {
787 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
788
789 } else {
790 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
791 }
792 count = 0; prevlen = curlen;
793 if (nextlen == 0) {
794 max_count = 138, min_count = 3;
795 } else if (curlen == nextlen) {
796 max_count = 6, min_count = 3;
797 } else {
798 max_count = 7, min_count = 4;
799 }
800 }
801 }
802
803 /* ===========================================================================
804 * Construct the Huffman tree for the bit lengths and return the index in
805 * bl_order of the last bit length code to send.
806 */
807 local int build_bl_tree(s)
808 deflate_state *s;
809 {
810 int max_blindex; /* index of last bit length code of non zero freq */
811
812 /* Determine the bit length frequencies for literal and distance trees */
813 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
814 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
815
816 /* Build the bit length tree: */
817 build_tree(s, (tree_desc *)(&(s->bl_desc)));
818 /* opt_len now includes the length of the tree representations, except
819 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
820 */
821
822 /* Determine the number of bit length codes to send. The pkzip format
823 * requires that at least 4 bit length codes be sent. (appnote.txt says
824 * 3 but the actual value used is 4.)
825 */
826 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
827 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
828 }
829 /* Update opt_len to include the bit length tree and counts */
830 s->opt_len += 3*(max_blindex+1) + 5+5+4;
831 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
832 s->opt_len, s->static_len));
833
834 return max_blindex;
835 }
836
837 /* ===========================================================================
838 * Send the header for a block using dynamic Huffman trees: the counts, the
839 * lengths of the bit length codes, the literal tree and the distance tree.
840 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
841 */
842 local void send_all_trees(s, lcodes, dcodes, blcodes)
843 deflate_state *s;
844 int lcodes, dcodes, blcodes; /* number of codes for each tree */
845 {
846 int rank; /* index in bl_order */
847
848 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
849 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
850 "too many codes");
851 Tracev((stderr, "\nbl counts: "));
852 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
853 send_bits(s, dcodes-1, 5);
854 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
855 for (rank = 0; rank < blcodes; rank++) {
856 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
857 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
858 }
859 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
860
861 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
862 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
863
864 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
865 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
866 }
867
868 /* ===========================================================================
869 * Send a stored block
870 */
871 void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
872 deflate_state *s;
873 charf *buf; /* input block */
874 ulg stored_len; /* length of input block */
875 int last; /* one if this is the last block for a file */
876 {
877 send_bits(s, (STORED_BLOCK<<1)+last, 3); /* send block type */
878 #ifdef DEBUG
879 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
880 s->compressed_len += (stored_len + 4) << 3;
881 #endif
882 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
883 }
884
885 /* ===========================================================================
886 * Send one empty static block to give enough lookahead for inflate.
887 * This takes 10 bits, of which 7 may remain in the bit buffer.
888 * The current inflate code requires 9 bits of lookahead. If the
889 * last two codes for the previous block (real code plus EOB) were coded
890 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
891 * the last real code. In this case we send two empty static blocks instead
892 * of one. (There are no problems if the previous block is stored or fixed.)
893 * To simplify the code, we assume the worst case of last real code encoded
894 * on one bit only.
895 */
896 void ZLIB_INTERNAL _tr_align(s)
897 deflate_state *s;
898 {
899 send_bits(s, STATIC_TREES<<1, 3);
900 send_code(s, END_BLOCK, static_ltree);
901 #ifdef DEBUG
902 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
903 #endif
904 bi_flush(s);
905 /* Of the 10 bits for the empty block, we have already sent
906 * (10 - bi_valid) bits. The lookahead for the last real code (before
907 * the EOB of the previous block) was thus at least one plus the length
908 * of the EOB plus what we have just sent of the empty static block.
909 */
910 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
911 send_bits(s, STATIC_TREES<<1, 3);
912 send_code(s, END_BLOCK, static_ltree);
913 #ifdef DEBUG
914 s->compressed_len += 10L;
915 #endif
916 bi_flush(s);
917 }
918 s->last_eob_len = 7;
919 }
920
921 /* ===========================================================================
922 * Determine the best encoding for the current block: dynamic trees, static
923 * trees or store, and output the encoded block to the zip file.
924 */
925 void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
926 deflate_state *s;
927 charf *buf; /* input block, or NULL if too old */
928 ulg stored_len; /* length of input block */
929 int last; /* one if this is the last block for a file */
930 {
931 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
932 int max_blindex = 0; /* index of last bit length code of non zero freq */
933
934 /* Build the Huffman trees unless a stored block is forced */
935 if (s->level > 0) {
936
937 /* Check if the file is binary or text */
938 if (s->strm->data_type == Z_UNKNOWN)
939 s->strm->data_type = detect_data_type(s);
940
941 /* Construct the literal and distance trees */
942 build_tree(s, (tree_desc *)(&(s->l_desc)));
943 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
944 s->static_len));
945
946 build_tree(s, (tree_desc *)(&(s->d_desc)));
947 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
948 s->static_len));
949 /* At this point, opt_len and static_len are the total bit lengths of
950 * the compressed block data, excluding the tree representations.
951 */
952
953 /* Build the bit length tree for the above two trees, and get the index
954 * in bl_order of the last bit length code to send.
955 */
956 max_blindex = build_bl_tree(s);
957
958 /* Determine the best encoding. Compute the block lengths in bytes. */
959 opt_lenb = (s->opt_len+3+7)>>3;
960 static_lenb = (s->static_len+3+7)>>3;
961
962 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
963 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
964 s->last_lit));
965
966 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
967
968 } else {
969 Assert(buf != (char*)0, "lost buf");
970 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
971 }
972
973 #ifdef FORCE_STORED
974 if (buf != (char*)0) { /* force stored block */
975 #else
976 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
977 /* 4: two words for the lengths */
978 #endif
979 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
980 * Otherwise we can't have processed more than WSIZE input bytes since
981 * the last block flush, because compression would have been
982 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
983 * transform a block into a stored block.
984 */
985 _tr_stored_block(s, buf, stored_len, last);
986
987 #ifdef FORCE_STATIC
988 } else if (static_lenb >= 0) { /* force static trees */
989 #else
990 } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
991 #endif
992 send_bits(s, (STATIC_TREES<<1)+last, 3);
993 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
994 #ifdef DEBUG
995 s->compressed_len += 3 + s->static_len;
996 #endif
997 } else {
998 send_bits(s, (DYN_TREES<<1)+last, 3);
999 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
1000 max_blindex+1);
1001 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
1002 #ifdef DEBUG
1003 s->compressed_len += 3 + s->opt_len;
1004 #endif
1005 }
1006 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
1007 /* The above check is made mod 2^32, for files larger than 512 MB
1008 * and uLong implemented on 32 bits.
1009 */
1010 init_block(s);
1011
1012 if (last) {
1013 bi_windup(s);
1014 #ifdef DEBUG
1015 s->compressed_len += 7; /* align on byte boundary */
1016 #endif
1017 }
1018 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
1019 s->compressed_len-7*last));
1020 }
1021
1022 /* ===========================================================================
1023 * Save the match info and tally the frequency counts. Return true if
1024 * the current block must be flushed.
1025 */
1026 int ZLIB_INTERNAL _tr_tally (s, dist, lc)
1027 deflate_state *s;
1028 unsigned dist; /* distance of matched string */
1029 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
1030 {
1031 s->d_buf[s->last_lit] = (ush)dist;
1032 s->l_buf[s->last_lit++] = (uch)lc;
1033 if (dist == 0) {
1034 /* lc is the unmatched char */
1035 s->dyn_ltree[lc].Freq++;
1036 } else {
1037 s->matches++;
1038 /* Here, lc is the match length - MIN_MATCH */
1039 dist--; /* dist = match distance - 1 */
1040 Assert((ush)dist < (ush)MAX_DIST(s) &&
1041 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
1042 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
1043
1044 s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
1045 s->dyn_dtree[d_code(dist)].Freq++;
1046 }
1047
1048 #ifdef TRUNCATE_BLOCK
1049 /* Try to guess if it is profitable to stop the current block here */
1050 if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
1051 /* Compute an upper bound for the compressed length */
1052 ulg out_length = (ulg)s->last_lit*8L;
1053 ulg in_length = (ulg)((long)s->strstart - s->block_start);
1054 int dcode;
1055 for (dcode = 0; dcode < D_CODES; dcode++) {
1056 out_length += (ulg)s->dyn_dtree[dcode].Freq *
1057 (5L+extra_dbits[dcode]);
1058 }
1059 out_length >>= 3;
1060 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
1061 s->last_lit, in_length, out_length,
1062 100L - out_length*100L/in_length));
1063 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
1064 }
1065 #endif
1066 return (s->last_lit == s->lit_bufsize-1);
1067 /* We avoid equality with lit_bufsize because of wraparound at 64K
1068 * on 16 bit machines and because stored blocks are restricted to
1069 * 64K-1 bytes.
1070 */
1071 }
1072
1073 /* ===========================================================================
1074 * Send the block data compressed using the given Huffman trees
1075 */
1076 local void compress_block(s, ltree, dtree)
1077 deflate_state *s;
1078 ct_data *ltree; /* literal tree */
1079 ct_data *dtree; /* distance tree */
1080 {
1081 unsigned dist; /* distance of matched string */
1082 int lc; /* match length or unmatched char (if dist == 0) */
1083 unsigned lx = 0; /* running index in l_buf */
1084 unsigned code; /* the code to send */
1085 int extra; /* number of extra bits to send */
1086
1087 if (s->last_lit != 0) do {
1088 dist = s->d_buf[lx];
1089 lc = s->l_buf[lx++];
1090 if (dist == 0) {
1091 send_code(s, lc, ltree); /* send a literal byte */
1092 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
1093 } else {
1094 /* Here, lc is the match length - MIN_MATCH */
1095 code = _length_code[lc];
1096 send_code(s, code+LITERALS+1, ltree); /* send the length code */
1097 extra = extra_lbits[code];
1098 if (extra != 0) {
1099 lc -= base_length[code];
1100 send_bits(s, lc, extra); /* send the extra length bits */
1101 }
1102 dist--; /* dist is now the match distance - 1 */
1103 code = d_code(dist);
1104 Assert (code < D_CODES, "bad d_code");
1105
1106 send_code(s, code, dtree); /* send the distance code */
1107 extra = extra_dbits[code];
1108 if (extra != 0) {
1109 dist -= base_dist[code];
1110 send_bits(s, dist, extra); /* send the extra distance bits */
1111 }
1112 } /* literal or match pair ? */
1113
1114 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
1115 Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
1116 "pendingBuf overflow");
1117
1118 } while (lx < s->last_lit);
1119
1120 send_code(s, END_BLOCK, ltree);
1121 s->last_eob_len = ltree[END_BLOCK].Len;
1122 }
1123
1124 /* ===========================================================================
1125 * Check if the data type is TEXT or BINARY, using the following algorithm:
1126 * - TEXT if the two conditions below are satisfied:
1127 * a) There are no non-portable control characters belonging to the
1128 * "black list" (0..6, 14..25, 28..31).
1129 * b) There is at least one printable character belonging to the
1130 * "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
1131 * - BINARY otherwise.
1132 * - The following partially-portable control characters form a
1133 * "gray list" that is ignored in this detection algorithm:
1134 * (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
1135 * IN assertion: the fields Freq of dyn_ltree are set.
1136 */
1137 local int detect_data_type(s)
1138 deflate_state *s;
1139 {
1140 /* black_mask is the bit mask of black-listed bytes
1141 * set bits 0..6, 14..25, and 28..31
1142 * 0xf3ffc07f = binary 11110011111111111100000001111111
1143 */
1144 unsigned long black_mask = 0xf3ffc07fUL;
1145 int n;
1146
1147 /* Check for non-textual ("black-listed") bytes. */
1148 for (n = 0; n <= 31; n++, black_mask >>= 1)
1149 if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
1150 return Z_BINARY;
1151
1152 /* Check for textual ("white-listed") bytes. */
1153 if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
1154 || s->dyn_ltree[13].Freq != 0)
1155 return Z_TEXT;
1156 for (n = 32; n < LITERALS; n++)
1157 if (s->dyn_ltree[n].Freq != 0)
1158 return Z_TEXT;
1159
1160 /* There are no "black-listed" or "white-listed" bytes:
1161 * this stream either is empty or has tolerated ("gray-listed") bytes only.
1162 */
1163 return Z_BINARY;
1164 }
1165
1166 /* ===========================================================================
1167 * Reverse the first len bits of a code, using straightforward code (a faster
1168 * method would use a table)
1169 * IN assertion: 1 <= len <= 15
1170 */
1171 local unsigned bi_reverse(code, len)
1172 unsigned code; /* the value to invert */
1173 int len; /* its bit length */
1174 {
1175 register unsigned res = 0;
1176 do {
1177 res |= code & 1;
1178 code >>= 1, res <<= 1;
1179 } while (--len > 0);
1180 return res >> 1;
1181 }
1182
1183 /* ===========================================================================
1184 * Flush the bit buffer, keeping at most 7 bits in it.
1185 */
1186 local void bi_flush(s)
1187 deflate_state *s;
1188 {
1189 if (s->bi_valid == 16) {
1190 put_short(s, s->bi_buf);
1191 s->bi_buf = 0;
1192 s->bi_valid = 0;
1193 } else if (s->bi_valid >= 8) {
1194 put_byte(s, (Byte)s->bi_buf);
1195 s->bi_buf >>= 8;
1196 s->bi_valid -= 8;
1197 }
1198 }
1199
1200 /* ===========================================================================
1201 * Flush the bit buffer and align the output on a byte boundary
1202 */
1203 local void bi_windup(s)
1204 deflate_state *s;
1205 {
1206 if (s->bi_valid > 8) {
1207 put_short(s, s->bi_buf);
1208 } else if (s->bi_valid > 0) {
1209 put_byte(s, (Byte)s->bi_buf);
1210 }
1211 s->bi_buf = 0;
1212 s->bi_valid = 0;
1213 #ifdef DEBUG
1214 s->bits_sent = (s->bits_sent+7) & ~7;
1215 #endif
1216 }
1217
1218 /* ===========================================================================
1219 * Copy a stored block, storing first the length and its
1220 * one's complement if requested.
1221 */
1222 local void copy_block(s, buf, len, header)
1223 deflate_state *s;
1224 charf *buf; /* the input data */
1225 unsigned len; /* its length */
1226 int header; /* true if block header must be written */
1227 {
1228 bi_windup(s); /* align on byte boundary */
1229 s->last_eob_len = 8; /* enough lookahead for inflate */
1230
1231 if (header) {
1232 put_short(s, (ush)len);
1233 put_short(s, (ush)~len);
1234 #ifdef DEBUG
1235 s->bits_sent += 2*16;
1236 #endif
1237 }
1238 #ifdef DEBUG
1239 s->bits_sent += (ulg)len<<3;
1240 #endif
1241 while (len--) {
1242 put_byte(s, *buf++);
1243 }
1244 }
extra_dbits
local const int extra_dbits[D_CODES]
Definition: trees.c:66
static_tree_desc_s
Definition: deflate.c:155
Tracecv
#define Tracecv(c, x)
Definition: zutil.h:261
static_dtree
local ct_data static_dtree[D_CODES]
Definition: trees.c:98
ushf
ush FAR ushf
Definition: zutil.h:40
static_tree_desc_s::extra_bits
const intf * extra_bits
Definition: trees.c:124
STORED_BLOCK
#define STORED_BLOCK
Definition: zutil.h:66
BL_CODES
#define BL_CODES
Definition: deflate.h:42
Byte
unsigned char Byte
Definition: zconf.h:333
MIN_MATCH
#define MIN_MATCH
Definition: zutil.h:71
detect_data_type
local int detect_data_type(deflate_state *s)
Definition: trees.c:1137
Z_UNKNOWN
#define Z_UNKNOWN
Definition: zlib.h:202
_tr_align
void ZLIB_INTERNAL _tr_align(deflate_state *s)
Definition: trees.c:896
MAX_BITS
#define MAX_BITS
Definition: deflate.h:48
static_tree_desc_s::extra_base
int extra_base
Definition: trees.c:125
Assert
#define Assert(cond, msg)
Definition: zutil.h:256
END_BLOCK
#define END_BLOCK
Definition: trees.c:50
SMALLEST
#define SMALLEST
Definition: trees.c:430
Tracev
#define Tracev(x)
Definition: zutil.h:258
base_dist
local int base_dist[D_CODES]
Definition: trees.c:115
pqdownheap
local void pqdownheap(deflate_state *s, ct_data *tree, int k)
Definition: trees.c:459
gen_codes
local void gen_codes(ct_data *tree, int max_code, ushf *bl_count)
Definition: trees.c:581
init_block
local void init_block(deflate_state *s)
Definition: trees.c:415
LENGTH_CODES
#define LENGTH_CODES
Definition: deflate.h:30
internal_state::dyn_ltree
struct ct_data_s dyn_ltree[HEAP_SIZE]
Definition: deflate.h:192
REP_3_6
#define REP_3_6
Definition: trees.c:53
ZLIB_INTERNAL
#define ZLIB_INTERNAL
Definition: compress.c:8
static_d_desc
local static_tree_desc static_d_desc
Definition: trees.c:133
tree_desc_s::dyn_tree
ct_data * dyn_tree
Definition: deflate.h:81
tree_desc_s::stat_desc
static_tree_desc * stat_desc
Definition: deflate.h:83
Z_FIXED
#define Z_FIXED
Definition: zlib.h:195
base_length
local int base_length[LENGTH_CODES]
Definition: trees.c:112
smaller
#define smaller(tree, n, m, depth)
Definition: trees.c:449
MAX_DIST
#define MAX_DIST(s)
Definition: deflate.h:283
REPZ_11_138
#define REPZ_11_138
Definition: trees.c:59
put_short
#define put_short(s, w)
Definition: trees.c:181
gen_bitlen
local void gen_bitlen(deflate_state *s, tree_desc *desc)
Definition: trees.c:494
tree_desc_s::max_code
int max_code
Definition: deflate.h:82
bi_reverse
local unsigned bi_reverse(unsigned code, int len)
Definition: trees.c:1171
LITERALS
#define LITERALS
Definition: deflate.h:33
send_all_trees
local void send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes)
Definition: trees.c:842
DIST_CODE_LEN
#define DIST_CODE_LEN
Definition: trees.c:86
OF
local void tr_static_init OF((void))
compress_block
local void compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree)
Definition: trees.c:1076
internal_state::strm
z_streamp strm
Definition: deflate.h:95
static_tree_desc_s::elems
int elems
Definition: trees.c:126
trees.h
Code
#define Code
Definition: deflate.h:74
_tr_init
void ZLIB_INTERNAL _tr_init(deflate_state *s)
Definition: trees.c:386
MAX_BL_BITS
#define MAX_BL_BITS
Definition: trees.c:47
send_bits
#define send_bits(s, value, length)
Definition: trees.c:218
ush
unsigned short ush
Definition: zutil.h:39
bits
unsigned int bits
Definition: tif_acorn.c:68
local
#define local
Definition: adler32.c:10
MAX_MATCH
#define MAX_MATCH
Definition: zutil.h:72
tree_desc_s
Definition: deflate.h:80
HEAP_SIZE
#define HEAP_SIZE
Definition: deflate.h:45
static_bl_desc
local static_tree_desc static_bl_desc
Definition: trees.c:136
Len
#define Len
Definition: deflate.h:76
put_byte
#define put_byte(s, c)
Definition: deflate.h:275
extra_lbits
local const int extra_lbits[LENGTH_CODES]
Definition: trees.c:63
tr_static_init
local void tr_static_init()
Definition: trees.c:239
bl_order
local const uch bl_order[BL_CODES]
Definition: trees.c:72
Z_BINARY
#define Z_BINARY
Definition: zlib.h:199
internal_state::d_buf
ushf * d_buf
Definition: deflate.h:238
Trace
#define Trace(x)
Definition: zutil.h:257
send_tree
local void send_tree(deflate_state *s, ct_data *tree, int max_code)
Definition: trees.c:756
_tr_stored_block
void ZLIB_INTERNAL _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int last)
Definition: trees.c:871
pqremove
#define pqremove(s, tree, top)
Definition: trees.c:438
code
Definition: inftrees.h:24
intf
int FAR intf
Definition: zconf.h:345
_dist_code
uch _dist_code[DIST_CODE_LEN]
Definition: trees.c:103
_tr_tally
int ZLIB_INTERNAL _tr_tally(deflate_state *s, unsigned dist, unsigned lc)
Definition: trees.c:1026
scan_tree
local void scan_tree(deflate_state *s, ct_data *tree, int max_code)
Definition: trees.c:711
Buf_size
#define Buf_size
Definition: trees.c:77
d_code
#define d_code(dist)
Definition: deflate.h:301
static_tree_desc_s::max_length
int max_length
Definition: trees.c:127
internal_state
Definition: deflate.h:94
uch
unsigned char uch
Definition: zutil.h:37
_length_code
uch _length_code[MAX_MATCH-MIN_MATCH+1]
Definition: trees.c:109
ulg
unsigned long ulg
Definition: zutil.h:41
bi_windup
local void bi_windup(deflate_state *s)
Definition: trees.c:1203
Freq
#define Freq
Definition: deflate.h:73
build_tree
local void build_tree(deflate_state *s, tree_desc *desc)
Definition: trees.c:623
build_bl_tree
local int build_bl_tree(deflate_state *s)
Definition: trees.c:807
copy_block
local void copy_block(deflate_state *s, charf *buf, unsigned len, int header)
Definition: trees.c:1222
STATIC_TREES
#define STATIC_TREES
Definition: zutil.h:67
ct_data_s
Definition: deflate.h:62
_tr_flush_block
void ZLIB_INTERNAL _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int last)
Definition: trees.c:925
static_tree_desc_s::static_tree
const ct_data * static_tree
Definition: trees.c:123
static_ltree
local ct_data static_ltree[L_CODES+2]
Definition: trees.c:91
deflate.h
D_CODES
#define D_CODES
Definition: deflate.h:39
REPZ_3_10
#define REPZ_3_10
Definition: trees.c:56
extra_blbits
local const int extra_blbits[BL_CODES]
Definition: trees.c:69
DYN_TREES
#define DYN_TREES
Definition: zutil.h:68
Z_TEXT
#define Z_TEXT
Definition: zlib.h:200
send_code
#define send_code(s, c, tree)
Definition: trees.c:168
bi_flush
local void bi_flush(deflate_state *s)
Definition: trees.c:1186
uInt
unsigned int uInt
Definition: zconf.h:335
charf
char FAR charf
Definition: zconf.h:344
static_l_desc
local static_tree_desc static_l_desc
Definition: trees.c:130
Tracevv
#define Tracevv(x)
Definition: zutil.h:259
L_CODES
#define L_CODES
Definition: deflate.h:36