1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 /* trees.c -- output deflated data using Huffman coding
26 * Copyright (C) 1995-2012 Jean-loup Gailly
27 * detect_data_type() function provided freely by Cosmin Truta, 2006
28 * For conditions of distribution and use, see copyright notice in zlib.h
29 */
30
31 /*
32 * ALGORITHM
33 *
34 * The "deflation" process uses several Huffman trees. The more
35 * common source values are represented by shorter bit sequences.
36 *
37 * Each code tree is stored in a compressed form which is itself
38 * a Huffman encoding of the lengths of all the code strings (in
39 * ascending order by source values). The actual code strings are
40 * reconstructed from the lengths in the inflate process, as described
41 * in the deflate specification.
42 *
43 * REFERENCES
44 *
45 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
46 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
47 *
48 * Storer, James A.
49 * Data Compression: Methods and Theory, pp. 49-50.
50 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
51 *
52 * Sedgewick, R.
53 * Algorithms, p290.
54 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
55 */
56
57 /* @(#) $Id$ */
58
59 /* #define GEN_TREES_H */
60
61 #include "deflate.h"
62
63 #ifdef DEBUG
64 # include <ctype.h>
65 #endif
66
67 /* ===========================================================================
68 * Constants
69 */
70
71 #define MAX_BL_BITS 7
72 /* Bit length codes must not exceed MAX_BL_BITS bits */
73
74 #define END_BLOCK 256
75 /* end of block literal code */
76
77 #define REP_3_6 16
78 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
79
80 #define REPZ_3_10 17
81 /* repeat a zero length 3-10 times (3 bits of repeat count) */
82
83 #define REPZ_11_138 18
84 /* repeat a zero length 11-138 times (7 bits of repeat count) */
85
86 local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
87 = {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};
88
89 local const int extra_dbits[D_CODES] /* extra bits for each distance code */
90 = {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};
91
92 local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
93 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
94
95 local const uch bl_order[BL_CODES]
96 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
97 /* The lengths of the bit length codes are sent in order of decreasing
98 * probability, to avoid transmitting the lengths for unused bit length codes.
99 */
100
101 /* ===========================================================================
102 * Local data. These are initialized only once.
103 */
104
105 #define DIST_CODE_LEN 512 /* see definition of array dist_code below */
106
107 #if defined(GEN_TREES_H) || !defined(STDC)
108 /* non ANSI compilers may not accept trees.h */
109
110 local ct_data static_ltree[L_CODES+2];
111 /* The static literal tree. Since the bit lengths are imposed, there is no
112 * need for the L_CODES extra codes used during heap construction. However
113 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
114 * below).
115 */
116
117 local ct_data static_dtree[D_CODES];
118 /* The static distance tree. (Actually a trivial tree since all codes use
119 * 5 bits.)
120 */
121
122 uch _dist_code[DIST_CODE_LEN];
123 /* Distance codes. The first 256 values correspond to the distances
124 * 3 .. 258, the last 256 values correspond to the top 8 bits of
125 * the 15 bit distances.
126 */
127
128 uch _length_code[MAX_MATCH-MIN_MATCH+1];
129 /* length code for each normalized match length (0 == MIN_MATCH) */
130
131 local int base_length[LENGTH_CODES];
132 /* First normalized length for each code (0 = MIN_MATCH) */
133
134 local int base_dist[D_CODES];
135 /* First normalized distance for each code (0 = distance of 1) */
136
137 #else
138 # include "trees.h"
139 #endif /* GEN_TREES_H */
140
141 struct static_tree_desc_s {
142 const ct_data *static_tree; /* static tree or NULL */
143 const intf *extra_bits; /* extra bits for each code or NULL */
144 int extra_base; /* base index for extra_bits */
145 int elems; /* max number of elements in the tree */
146 int max_length; /* max bit length for the codes */
147 };
148
149 local static_tree_desc static_l_desc =
150 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
151
152 local static_tree_desc static_d_desc =
153 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
154
155 local static_tree_desc static_bl_desc =
156 {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
157
158 /* ===========================================================================
159 * Local (static) routines in this file.
160 */
161
162 local void tr_static_init OF((void));
163 local void init_block OF((deflate_state *s));
164 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
165 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
166 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
167 local void build_tree OF((deflate_state *s, tree_desc *desc));
168 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
169 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
170 local int build_bl_tree OF((deflate_state *s));
171 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
172 int blcodes));
173 local void compress_block OF((deflate_state *s, const ct_data *ltree,
174 const ct_data *dtree));
175 local int detect_data_type OF((deflate_state *s));
176 local unsigned bi_reverse OF((unsigned value, int length));
177 local void bi_windup OF((deflate_state *s));
178 local void bi_flush OF((deflate_state *s));
179 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
180 int header));
181
182 #ifdef GEN_TREES_H
183 local void gen_trees_header OF((void));
184 #endif
185
186 #ifndef DEBUG
187 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
188 /* Send a code of the given tree. c and tree must not have side effects */
189
190 #else /* DEBUG */
191 # define send_code(s, c, tree) \
192 { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
193 send_bits(s, tree[c].Code, tree[c].Len); }
194 #endif
195
196 /* ===========================================================================
197 * Output a short LSB first on the stream.
198 * IN assertion: there is enough room in pendingBuf.
199 */
200 #define put_short(s, w) { \
201 put_byte(s, (uch)((w) & 0xff)); \
202 put_byte(s, (uch)((ush)(w) >> 8)); \
203 }
204
205 /* ===========================================================================
206 * Send a value on a given number of bits.
207 * IN assertion: length <= 16 and value fits in length bits.
208 */
209 #ifdef DEBUG
210 local void send_bits OF((deflate_state *s, int value, int length));
211
212 local void send_bits(s, value, length)
213 deflate_state *s;
214 int value; /* value to send */
215 int length; /* number of bits */
216 {
217 Tracevv((stderr," l %2d v %4x ", length, value));
218 Assert(length > 0 && length <= 15, "invalid length");
219 s->bits_sent += (ulg)length;
220
221 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
222 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
223 * unused bits in value.
224 */
225 if (s->bi_valid > (int)Buf_size - length) {
226 s->bi_buf |= (ush)value << s->bi_valid;
227 put_short(s, s->bi_buf);
228 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
229 s->bi_valid += length - Buf_size;
230 } else {
231 s->bi_buf |= (ush)value << s->bi_valid;
232 s->bi_valid += length;
233 }
234 }
235 #else /* !DEBUG */
236
237 #define send_bits(s, value, length) \
238 { int len = length;\
239 if (s->bi_valid > (int)Buf_size - len) {\
240 int val = value;\
241 s->bi_buf |= (ush)val << s->bi_valid;\
242 put_short(s, s->bi_buf);\
243 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
244 s->bi_valid += len - Buf_size;\
245 } else {\
246 s->bi_buf |= (ush)(value) << s->bi_valid;\
247 s->bi_valid += len;\
248 }\
249 }
250 #endif /* DEBUG */
251
252
253 /* the arguments must not have side effects */
254
255 /* ===========================================================================
256 * Initialize the various 'constant' tables.
257 */
258 local void tr_static_init()
259 {
260 #if defined(GEN_TREES_H) || !defined(STDC)
261 static int static_init_done = 0;
262 int n; /* iterates over tree elements */
263 int bits; /* bit counter */
264 int length; /* length value */
265 int code; /* code value */
266 int dist; /* distance index */
267 ush bl_count[MAX_BITS+1];
268 /* number of codes at each bit length for an optimal tree */
269
270 if (static_init_done) return;
271
272 /* For some embedded targets, global variables are not initialized: */
273 #ifdef NO_INIT_GLOBAL_POINTERS
274 static_l_desc.static_tree = static_ltree;
275 static_l_desc.extra_bits = extra_lbits;
276 static_d_desc.static_tree = static_dtree;
277 static_d_desc.extra_bits = extra_dbits;
278 static_bl_desc.extra_bits = extra_blbits;
279 #endif
280
281 /* Initialize the mapping length (0..255) -> length code (0..28) */
282 length = 0;
283 for (code = 0; code < LENGTH_CODES-1; code++) {
284 base_length[code] = length;
285 for (n = 0; n < (1<<extra_lbits[code]); n++) {
286 _length_code[length++] = (uch)code;
287 }
288 }
289 Assert (length == 256, "tr_static_init: length != 256");
290 /* Note that the length 255 (match length 258) can be represented
291 * in two different ways: code 284 + 5 bits or code 285, so we
292 * overwrite length_code[255] to use the best encoding:
293 */
294 _length_code[length-1] = (uch)code;
295
296 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
297 dist = 0;
298 for (code = 0 ; code < 16; code++) {
299 base_dist[code] = dist;
300 for (n = 0; n < (1<<extra_dbits[code]); n++) {
301 _dist_code[dist++] = (uch)code;
302 }
303 }
304 Assert (dist == 256, "tr_static_init: dist != 256");
305 dist >>= 7; /* from now on, all distances are divided by 128 */
306 for ( ; code < D_CODES; code++) {
307 base_dist[code] = dist << 7;
308 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
309 _dist_code[256 + dist++] = (uch)code;
310 }
311 }
312 Assert (dist == 256, "tr_static_init: 256+dist != 512");
313
314 /* Construct the codes of the static literal tree */
315 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
316 n = 0;
317 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
318 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
319 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
320 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
321 /* Codes 286 and 287 do not exist, but we must include them in the
322 * tree construction to get a canonical Huffman tree (longest code
323 * all ones)
324 */
325 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
326
327 /* The static distance tree is trivial: */
328 for (n = 0; n < D_CODES; n++) {
329 static_dtree[n].Len = 5;
330 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
331 }
332 static_init_done = 1;
333
334 # ifdef GEN_TREES_H
335 gen_trees_header();
336 # endif
337 #endif /* defined(GEN_TREES_H) || !defined(STDC) */
338 }
339
340 /* ===========================================================================
341 * Genererate the file trees.h describing the static trees.
342 */
343 #ifdef GEN_TREES_H
344 # ifndef DEBUG
345 # include <stdio.h>
346 # endif
347
348 # define SEPARATOR(i, last, width) \
349 ((i) == (last)? "\n};\n\n" : \
350 ((i) % (width) == (width)-1 ? ",\n" : ", "))
351
352 void gen_trees_header()
353 {
354 FILE *header = fopen("trees.h", "w");
355 int i;
356
357 Assert (header != NULL, "Can't open trees.h");
358 fprintf(header,
359 "/* header created automatically with -DGEN_TREES_H */\n\n");
360
361 fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
362 for (i = 0; i < L_CODES+2; i++) {
363 fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
364 static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
365 }
366
367 fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
368 for (i = 0; i < D_CODES; i++) {
369 fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
370 static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
371 }
372
373 fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");
374 for (i = 0; i < DIST_CODE_LEN; i++) {
375 fprintf(header, "%2u%s", _dist_code[i],
376 SEPARATOR(i, DIST_CODE_LEN-1, 20));
377 }
378
379 fprintf(header,
380 "const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
381 for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
382 fprintf(header, "%2u%s", _length_code[i],
383 SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
384 }
385
386 fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
387 for (i = 0; i < LENGTH_CODES; i++) {
388 fprintf(header, "%1u%s", base_length[i],
389 SEPARATOR(i, LENGTH_CODES-1, 20));
390 }
391
392 fprintf(header, "local const int base_dist[D_CODES] = {\n");
393 for (i = 0; i < D_CODES; i++) {
394 fprintf(header, "%5u%s", base_dist[i],
395 SEPARATOR(i, D_CODES-1, 10));
396 }
397
398 fclose(header);
399 }
400 #endif /* GEN_TREES_H */
401
402 /* ===========================================================================
403 * Initialize the tree data structures for a new zlib stream.
404 */
405 void ZLIB_INTERNAL _tr_init(s)
406 deflate_state *s;
407 {
408 tr_static_init();
409
410 s->l_desc.dyn_tree = s->dyn_ltree;
411 s->l_desc.stat_desc = &static_l_desc;
412
413 s->d_desc.dyn_tree = s->dyn_dtree;
414 s->d_desc.stat_desc = &static_d_desc;
415
416 s->bl_desc.dyn_tree = s->bl_tree;
417 s->bl_desc.stat_desc = &static_bl_desc;
418
419 s->bi_buf = 0;
420 s->bi_valid = 0;
421 #ifdef DEBUG
422 s->compressed_len = 0L;
423 s->bits_sent = 0L;
424 #endif
425
426 /* Initialize the first block of the first file: */
427 init_block(s);
428 }
429
430 /* ===========================================================================
431 * Initialize a new block.
432 */
433 local void init_block(s)
434 deflate_state *s;
435 {
436 int n; /* iterates over tree elements */
437
438 /* Initialize the trees. */
439 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
440 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
441 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
442
443 s->dyn_ltree[END_BLOCK].Freq = 1;
444 s->opt_len = s->static_len = 0L;
445 s->last_lit = s->matches = 0;
446 }
447
448 #define SMALLEST 1
449 /* Index within the heap array of least frequent node in the Huffman tree */
450
451
452 /* ===========================================================================
453 * Remove the smallest element from the heap and recreate the heap with
454 * one less element. Updates heap and heap_len.
455 */
456 #define pqremove(s, tree, top) \
457 {\
458 top = s->heap[SMALLEST]; \
459 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
460 pqdownheap(s, tree, SMALLEST); \
461 }
462
463 /* ===========================================================================
464 * Compares to subtrees, using the tree depth as tie breaker when
465 * the subtrees have equal frequency. This minimizes the worst case length.
466 */
467 #define smaller(tree, n, m, depth) \
468 (tree[n].Freq < tree[m].Freq || \
469 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
470
471 /* ===========================================================================
472 * Restore the heap property by moving down the tree starting at node k,
473 * exchanging a node with the smallest of its two sons if necessary, stopping
474 * when the heap property is re-established (each father smaller than its
475 * two sons).
476 */
477 local void pqdownheap(s, tree, k)
478 deflate_state *s;
479 ct_data *tree; /* the tree to restore */
480 int k; /* node to move down */
481 {
482 int v = s->heap[k];
483 int j = k << 1; /* left son of k */
484 while (j <= s->heap_len) {
485 /* Set j to the smallest of the two sons: */
486 if (j < s->heap_len &&
487 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
488 j++;
489 }
490 /* Exit if v is smaller than both sons */
491 if (smaller(tree, v, s->heap[j], s->depth)) break;
492
493 /* Exchange v with the smallest son */
494 s->heap[k] = s->heap[j]; k = j;
495
496 /* And continue down the tree, setting j to the left son of k */
497 j <<= 1;
498 }
499 s->heap[k] = v;
500 }
501
502 /* ===========================================================================
503 * Compute the optimal bit lengths for a tree and update the total bit length
504 * for the current block.
505 * IN assertion: the fields freq and dad are set, heap[heap_max] and
506 * above are the tree nodes sorted by increasing frequency.
507 * OUT assertions: the field len is set to the optimal bit length, the
508 * array bl_count contains the frequencies for each bit length.
509 * The length opt_len is updated; static_len is also updated if stree is
510 * not null.
511 */
512 local void gen_bitlen(s, desc)
513 deflate_state *s;
514 tree_desc *desc; /* the tree descriptor */
515 {
516 ct_data *tree = desc->dyn_tree;
517 int max_code = desc->max_code;
518 const ct_data *stree = desc->stat_desc->static_tree;
519 const intf *extra = desc->stat_desc->extra_bits;
520 int base = desc->stat_desc->extra_base;
521 int max_length = desc->stat_desc->max_length;
522 int h; /* heap index */
523 int n, m; /* iterate over the tree elements */
524 int bits; /* bit length */
525 int xbits; /* extra bits */
526 ush f; /* frequency */
527 int overflow = 0; /* number of elements with bit length too large */
528
529 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
530
531 /* In a first pass, compute the optimal bit lengths (which may
532 * overflow in the case of the bit length tree).
533 */
534 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
535
536 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
537 n = s->heap[h];
538 bits = tree[tree[n].Dad].Len + 1;
539 if (bits > max_length) bits = max_length, overflow++;
540 tree[n].Len = (ush)bits;
541 /* We overwrite tree[n].Dad which is no longer needed */
542
543 if (n > max_code) continue; /* not a leaf node */
544
545 s->bl_count[bits]++;
546 xbits = 0;
547 if (n >= base) xbits = extra[n-base];
548 f = tree[n].Freq;
549 s->opt_len += (ulg)f * (bits + xbits);
550 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
551 }
552 if (overflow == 0) return;
553
554 Trace((stderr,"\nbit length overflow\n"));
555 /* This happens for example on obj2 and pic of the Calgary corpus */
556
557 /* Find the first bit length which could increase: */
558 do {
559 bits = max_length-1;
560 while (s->bl_count[bits] == 0) bits--;
561 s->bl_count[bits]--; /* move one leaf down the tree */
562 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
563 s->bl_count[max_length]--;
564 /* The brother of the overflow item also moves one step up,
565 * but this does not affect bl_count[max_length]
566 */
567 overflow -= 2;
568 } while (overflow > 0);
569
570 /* Now recompute all bit lengths, scanning in increasing frequency.
571 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
572 * lengths instead of fixing only the wrong ones. This idea is taken
573 * from 'ar' written by Haruhiko Okumura.)
574 */
575 for (bits = max_length; bits != 0; bits--) {
576 n = s->bl_count[bits];
577 while (n != 0) {
578 m = s->heap[--h];
579 if (m > max_code) continue;
580 if ((unsigned) tree[m].Len != (unsigned) bits) {
581 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
582 s->opt_len += ((long)bits - (long)tree[m].Len)
583 *(long)tree[m].Freq;
584 tree[m].Len = (ush)bits;
585 }
586 n--;
587 }
588 }
589 }
590
591 /* ===========================================================================
592 * Generate the codes for a given tree and bit counts (which need not be
593 * optimal).
594 * IN assertion: the array bl_count contains the bit length statistics for
595 * the given tree and the field len is set for all tree elements.
596 * OUT assertion: the field code is set for all tree elements of non
597 * zero code length.
598 */
599 local void gen_codes (tree, max_code, bl_count)
600 ct_data *tree; /* the tree to decorate */
601 int max_code; /* largest code with non zero frequency */
602 ushf *bl_count; /* number of codes at each bit length */
603 {
604 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
605 ush code = 0; /* running code value */
606 int bits; /* bit index */
607 int n; /* code index */
608
609 /* The distribution counts are first used to generate the code values
610 * without bit reversal.
611 */
612 for (bits = 1; bits <= MAX_BITS; bits++) {
613 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
614 }
615 /* Check that the bit counts in bl_count are consistent. The last code
616 * must be all ones.
617 */
618 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
619 "inconsistent bit counts");
620 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
621
622 for (n = 0; n <= max_code; n++) {
623 int len = tree[n].Len;
624 if (len == 0) continue;
625 /* Now reverse the bits */
626 tree[n].Code = bi_reverse(next_code[len]++, len);
627
628 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
629 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
630 }
631 }
632
633 /* ===========================================================================
634 * Construct one Huffman tree and assigns the code bit strings and lengths.
635 * Update the total bit length for the current block.
636 * IN assertion: the field freq is set for all tree elements.
637 * OUT assertions: the fields len and code are set to the optimal bit length
638 * and corresponding code. The length opt_len is updated; static_len is
639 * also updated if stree is not null. The field max_code is set.
640 */
641 local void build_tree(s, desc)
642 deflate_state *s;
643 tree_desc *desc; /* the tree descriptor */
644 {
645 ct_data *tree = desc->dyn_tree;
646 const ct_data *stree = desc->stat_desc->static_tree;
647 int elems = desc->stat_desc->elems;
648 int n, m; /* iterate over heap elements */
649 int max_code = -1; /* largest code with non zero frequency */
650 int node; /* new node being created */
651
652 /* Construct the initial heap, with least frequent element in
653 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
654 * heap[0] is not used.
655 */
656 s->heap_len = 0, s->heap_max = HEAP_SIZE;
657
658 for (n = 0; n < elems; n++) {
659 if (tree[n].Freq != 0) {
660 s->heap[++(s->heap_len)] = max_code = n;
661 s->depth[n] = 0;
662 } else {
663 tree[n].Len = 0;
664 }
665 }
666
667 /* The pkzip format requires that at least one distance code exists,
668 * and that at least one bit should be sent even if there is only one
669 * possible code. So to avoid special checks later on we force at least
670 * two codes of non zero frequency.
671 */
672 while (s->heap_len < 2) {
673 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
674 tree[node].Freq = 1;
675 s->depth[node] = 0;
676 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
677 /* node is 0 or 1 so it does not have extra bits */
678 }
679 desc->max_code = max_code;
680
681 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
682 * establish sub-heaps of increasing lengths:
683 */
684 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
685
686 /* Construct the Huffman tree by repeatedly combining the least two
687 * frequent nodes.
688 */
689 node = elems; /* next internal node of the tree */
690 do {
691 pqremove(s, tree, n); /* n = node of least frequency */
692 m = s->heap[SMALLEST]; /* m = node of next least frequency */
693
694 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
695 s->heap[--(s->heap_max)] = m;
696
697 /* Create a new node father of n and m */
698 tree[node].Freq = tree[n].Freq + tree[m].Freq;
699 s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?
700 s->depth[n] : s->depth[m]) + 1);
701 tree[n].Dad = tree[m].Dad = (ush)node;
702 #ifdef DUMP_BL_TREE
703 if (tree == s->bl_tree) {
704 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
705 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
706 }
707 #endif
708 /* and insert the new node in the heap */
709 s->heap[SMALLEST] = node++;
710 pqdownheap(s, tree, SMALLEST);
711
712 } while (s->heap_len >= 2);
713
714 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
715
716 /* At this point, the fields freq and dad are set. We can now
717 * generate the bit lengths.
718 */
719 gen_bitlen(s, (tree_desc *)desc);
720
721 /* The field len is now set, we can generate the bit codes */
722 gen_codes ((ct_data *)tree, max_code, s->bl_count);
723 }
724
725 /* ===========================================================================
726 * Scan a literal or distance tree to determine the frequencies of the codes
727 * in the bit length tree.
728 */
729 local void scan_tree (s, tree, max_code)
730 deflate_state *s;
731 ct_data *tree; /* the tree to be scanned */
732 int max_code; /* and its largest code of non zero frequency */
733 {
734 int n; /* iterates over all tree elements */
735 int prevlen = -1; /* last emitted length */
736 int curlen; /* length of current code */
737 int nextlen = tree[0].Len; /* length of next code */
738 int count = 0; /* repeat count of the current code */
739 int max_count = 7; /* max repeat count */
740 int min_count = 4; /* min repeat count */
741
742 if (nextlen == 0) max_count = 138, min_count = 3;
743 tree[max_code+1].Len = (ush)0xffff; /* guard */
744
745 for (n = 0; n <= max_code; n++) {
746 curlen = nextlen; nextlen = tree[n+1].Len;
747 if (++count < max_count && curlen == nextlen) {
748 continue;
749 } else if (count < min_count) {
750 s->bl_tree[curlen].Freq += count;
751 } else if (curlen != 0) {
752 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
753 s->bl_tree[REP_3_6].Freq++;
754 } else if (count <= 10) {
755 s->bl_tree[REPZ_3_10].Freq++;
756 } else {
757 s->bl_tree[REPZ_11_138].Freq++;
758 }
759 count = 0; prevlen = curlen;
760 if (nextlen == 0) {
761 max_count = 138, min_count = 3;
762 } else if (curlen == nextlen) {
763 max_count = 6, min_count = 3;
764 } else {
765 max_count = 7, min_count = 4;
766 }
767 }
768 }
769
770 /* ===========================================================================
771 * Send a literal or distance tree in compressed form, using the codes in
772 * bl_tree.
773 */
774 local void send_tree (s, tree, max_code)
775 deflate_state *s;
776 ct_data *tree; /* the tree to be scanned */
777 int max_code; /* and its largest code of non zero frequency */
778 {
779 int n; /* iterates over all tree elements */
780 int prevlen = -1; /* last emitted length */
781 int curlen; /* length of current code */
782 int nextlen = tree[0].Len; /* length of next code */
783 int count = 0; /* repeat count of the current code */
784 int max_count = 7; /* max repeat count */
785 int min_count = 4; /* min repeat count */
786
787 /* tree[max_code+1].Len = -1; */ /* guard already set */
788 if (nextlen == 0) max_count = 138, min_count = 3;
789
790 for (n = 0; n <= max_code; n++) {
791 curlen = nextlen; nextlen = tree[n+1].Len;
792 if (++count < max_count && curlen == nextlen) {
793 continue;
794 } else if (count < min_count) {
795 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
796
797 } else if (curlen != 0) {
798 if (curlen != prevlen) {
799 send_code(s, curlen, s->bl_tree); count--;
800 }
801 Assert(count >= 3 && count <= 6, " 3_6?");
802 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
803
804 } else if (count <= 10) {
805 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
806
807 } else {
808 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
809 }
810 count = 0; prevlen = curlen;
811 if (nextlen == 0) {
812 max_count = 138, min_count = 3;
813 } else if (curlen == nextlen) {
814 max_count = 6, min_count = 3;
815 } else {
816 max_count = 7, min_count = 4;
817 }
818 }
819 }
820
821 /* ===========================================================================
822 * Construct the Huffman tree for the bit lengths and return the index in
823 * bl_order of the last bit length code to send.
824 */
825 local int build_bl_tree(s)
826 deflate_state *s;
827 {
828 int max_blindex; /* index of last bit length code of non zero freq */
829
830 /* Determine the bit length frequencies for literal and distance trees */
831 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
832 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
833
834 /* Build the bit length tree: */
835 build_tree(s, (tree_desc *)(&(s->bl_desc)));
836 /* opt_len now includes the length of the tree representations, except
837 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
838 */
839
840 /* Determine the number of bit length codes to send. The pkzip format
841 * requires that at least 4 bit length codes be sent. (appnote.txt says
842 * 3 but the actual value used is 4.)
843 */
844 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
845 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
846 }
847 /* Update opt_len to include the bit length tree and counts */
848 s->opt_len += 3*(max_blindex+1) + 5+5+4;
849 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
850 s->opt_len, s->static_len));
851
852 return max_blindex;
853 }
854
855 /* ===========================================================================
856 * Send the header for a block using dynamic Huffman trees: the counts, the
857 * lengths of the bit length codes, the literal tree and the distance tree.
858 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
859 */
860 local void send_all_trees(s, lcodes, dcodes, blcodes)
861 deflate_state *s;
862 int lcodes, dcodes, blcodes; /* number of codes for each tree */
863 {
864 int rank; /* index in bl_order */
865
866 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
867 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
868 "too many codes");
869 Tracev((stderr, "\nbl counts: "));
870 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
871 send_bits(s, dcodes-1, 5);
872 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
873 for (rank = 0; rank < blcodes; rank++) {
874 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
875 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
876 }
877 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
878
879 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
880 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
881
882 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
883 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
884 }
885
886 /* ===========================================================================
887 * Send a stored block
888 */
889 void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
890 deflate_state *s;
891 charf *buf; /* input block */
892 ulg stored_len; /* length of input block */
893 int last; /* one if this is the last block for a file */
894 {
895 send_bits(s, (STORED_BLOCK<<1)+last, 3); /* send block type */
896 #ifdef DEBUG
897 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
898 s->compressed_len += (stored_len + 4) << 3;
899 #endif
900 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
901 }
902
903 /* ===========================================================================
904 * Flush the bits in the bit buffer to pending output (leaves at most 7 bits)
905 */
906 void ZLIB_INTERNAL _tr_flush_bits(s)
907 deflate_state *s;
908 {
909 bi_flush(s);
910 }
911
912 /* ===========================================================================
913 * Send one empty static block to give enough lookahead for inflate.
914 * This takes 10 bits, of which 7 may remain in the bit buffer.
915 */
916 void ZLIB_INTERNAL _tr_align(s)
917 deflate_state *s;
918 {
919 send_bits(s, STATIC_TREES<<1, 3);
920 send_code(s, END_BLOCK, static_ltree);
921 #ifdef DEBUG
922 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
923 #endif
924 bi_flush(s);
925 }
926
927 /* ===========================================================================
928 * Determine the best encoding for the current block: dynamic trees, static
929 * trees or store, and output the encoded block to the zip file.
930 */
931 void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
932 deflate_state *s;
933 charf *buf; /* input block, or NULL if too old */
934 ulg stored_len; /* length of input block */
935 int last; /* one if this is the last block for a file */
936 {
937 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
938 int max_blindex = 0; /* index of last bit length code of non zero freq */
939
940 /* Build the Huffman trees unless a stored block is forced */
941 if (s->level > 0) {
942
943 /* Check if the file is binary or text */
944 if (s->strm->data_type == Z_UNKNOWN)
945 s->strm->data_type = detect_data_type(s);
946
947 /* Construct the literal and distance trees */
948 build_tree(s, (tree_desc *)(&(s->l_desc)));
949 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
950 s->static_len));
951
952 build_tree(s, (tree_desc *)(&(s->d_desc)));
953 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
954 s->static_len));
955 /* At this point, opt_len and static_len are the total bit lengths of
956 * the compressed block data, excluding the tree representations.
957 */
958
959 /* Build the bit length tree for the above two trees, and get the index
960 * in bl_order of the last bit length code to send.
961 */
962 max_blindex = build_bl_tree(s);
963
964 /* Determine the best encoding. Compute the block lengths in bytes. */
965 opt_lenb = (s->opt_len+3+7)>>3;
966 static_lenb = (s->static_len+3+7)>>3;
967
968 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
969 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
970 s->last_lit));
971
972 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
973
974 } else {
975 Assert(buf != (char*)0, "lost buf");
976 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
977 }
978
979 #ifdef FORCE_STORED
980 if (buf != (char*)0) { /* force stored block */
981 #else
982 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
983 /* 4: two words for the lengths */
984 #endif
985 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
986 * Otherwise we can't have processed more than WSIZE input bytes since
987 * the last block flush, because compression would have been
988 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
989 * transform a block into a stored block.
990 */
991 _tr_stored_block(s, buf, stored_len, last);
992
993 #ifdef FORCE_STATIC
994 } else if (static_lenb >= 0) { /* force static trees */
995 #else
996 } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
997 #endif
998 send_bits(s, (STATIC_TREES<<1)+last, 3);
999 compress_block(s, (const ct_data *)static_ltree,
1000 (const ct_data *)static_dtree);
1001 #ifdef DEBUG
1002 s->compressed_len += 3 + s->static_len;
1003 #endif
1004 } else {
1005 send_bits(s, (DYN_TREES<<1)+last, 3);
1006 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
1007 max_blindex+1);
1008 compress_block(s, (const ct_data *)s->dyn_ltree,
1009 (const ct_data *)s->dyn_dtree);
1010 #ifdef DEBUG
1011 s->compressed_len += 3 + s->opt_len;
1012 #endif
1013 }
1014 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
1015 /* The above check is made mod 2^32, for files larger than 512 MB
1016 * and uLong implemented on 32 bits.
1017 */
1018 init_block(s);
1019
1020 if (last) {
1021 bi_windup(s);
1022 #ifdef DEBUG
1023 s->compressed_len += 7; /* align on byte boundary */
1024 #endif
1025 }
1026 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
1027 s->compressed_len-7*last));
1028 }
1029
1030 /* ===========================================================================
1031 * Save the match info and tally the frequency counts. Return true if
1032 * the current block must be flushed.
1033 */
1034 int ZLIB_INTERNAL _tr_tally (s, dist, lc)
1035 deflate_state *s;
1036 unsigned dist; /* distance of matched string */
1037 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
1038 {
1039 s->d_buf[s->last_lit] = (ush)dist;
1040 s->l_buf[s->last_lit++] = (uch)lc;
1041 if (dist == 0) {
1042 /* lc is the unmatched char */
1043 s->dyn_ltree[lc].Freq++;
1044 } else {
1045 s->matches++;
1046 /* Here, lc is the match length - MIN_MATCH */
1047 dist--; /* dist = match distance - 1 */
1048 Assert((ush)dist < (ush)MAX_DIST(s) &&
1049 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
1050 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
1051
1052 s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
1053 s->dyn_dtree[d_code(dist)].Freq++;
1054 }
1055
1056 #ifdef TRUNCATE_BLOCK
1057 /* Try to guess if it is profitable to stop the current block here */
1058 if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
1059 /* Compute an upper bound for the compressed length */
1060 ulg out_length = (ulg)s->last_lit*8L;
1061 ulg in_length = (ulg)((long)s->strstart - s->block_start);
1062 int dcode;
1063 for (dcode = 0; dcode < D_CODES; dcode++) {
1064 out_length += (ulg)s->dyn_dtree[dcode].Freq *
1065 (5L+extra_dbits[dcode]);
1066 }
1067 out_length >>= 3;
1068 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
1069 s->last_lit, in_length, out_length,
1070 100L - out_length*100L/in_length));
1071 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
1072 }
1073 #endif
1074 return (s->last_lit == s->lit_bufsize-1);
1075 /* We avoid equality with lit_bufsize because of wraparound at 64K
1076 * on 16 bit machines and because stored blocks are restricted to
1077 * 64K-1 bytes.
1078 */
1079 }
1080
1081 /* ===========================================================================
1082 * Send the block data compressed using the given Huffman trees
1083 */
1084 local void compress_block(s, ltree, dtree)
1085 deflate_state *s;
1086 const ct_data *ltree; /* literal tree */
1087 const ct_data *dtree; /* distance tree */
1088 {
1089 unsigned dist; /* distance of matched string */
1090 int lc; /* match length or unmatched char (if dist == 0) */
1091 unsigned lx = 0; /* running index in l_buf */
1092 unsigned code; /* the code to send */
1093 int extra; /* number of extra bits to send */
1094
1095 if (s->last_lit != 0) do {
1096 dist = s->d_buf[lx];
1097 lc = s->l_buf[lx++];
1098 if (dist == 0) {
1099 send_code(s, lc, ltree); /* send a literal byte */
1100 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
1101 } else {
1102 /* Here, lc is the match length - MIN_MATCH */
1103 code = _length_code[lc];
1104 send_code(s, code+LITERALS+1, ltree); /* send the length code */
1105 extra = extra_lbits[code];
1106 if (extra != 0) {
1107 lc -= base_length[code];
1108 send_bits(s, lc, extra); /* send the extra length bits */
1109 }
1110 dist--; /* dist is now the match distance - 1 */
1111 code = d_code(dist);
1112 Assert (code < D_CODES, "bad d_code");
1113
1114 send_code(s, code, dtree); /* send the distance code */
1115 extra = extra_dbits[code];
1116 if (extra != 0) {
1117 dist -= base_dist[code];
1118 send_bits(s, dist, extra); /* send the extra distance bits */
1119 }
1120 } /* literal or match pair ? */
1121
1122 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
1123 Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
1124 "pendingBuf overflow");
1125
1126 } while (lx < s->last_lit);
1127
1128 send_code(s, END_BLOCK, ltree);
1129 }
1130
1131 /* ===========================================================================
1132 * Check if the data type is TEXT or BINARY, using the following algorithm:
1133 * - TEXT if the two conditions below are satisfied:
1134 * a) There are no non-portable control characters belonging to the
1135 * "black list" (0..6, 14..25, 28..31).
1136 * b) There is at least one printable character belonging to the
1137 * "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
1138 * - BINARY otherwise.
1139 * - The following partially-portable control characters form a
1140 * "gray list" that is ignored in this detection algorithm:
1141 * (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
1142 * IN assertion: the fields Freq of dyn_ltree are set.
1143 */
1144 local int detect_data_type(s)
1145 deflate_state *s;
1146 {
1147 /* black_mask is the bit mask of black-listed bytes
1148 * set bits 0..6, 14..25, and 28..31
1149 * 0xf3ffc07f = binary 11110011111111111100000001111111
1150 */
1151 unsigned long black_mask = 0xf3ffc07fUL;
1152 int n;
1153
1154 /* Check for non-textual ("black-listed") bytes. */
1155 for (n = 0; n <= 31; n++, black_mask >>= 1)
1156 if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
1157 return Z_BINARY;
1158
1159 /* Check for textual ("white-listed") bytes. */
1160 if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
1161 || s->dyn_ltree[13].Freq != 0)
1162 return Z_TEXT;
1163 for (n = 32; n < LITERALS; n++)
1164 if (s->dyn_ltree[n].Freq != 0)
1165 return Z_TEXT;
1166
1167 /* There are no "black-listed" or "white-listed" bytes:
1168 * this stream either is empty or has tolerated ("gray-listed") bytes only.
1169 */
1170 return Z_BINARY;
1171 }
1172
1173 /* ===========================================================================
1174 * Reverse the first len bits of a code, using straightforward code (a faster
1175 * method would use a table)
1176 * IN assertion: 1 <= len <= 15
1177 */
1178 local unsigned bi_reverse(code, len)
1179 unsigned code; /* the value to invert */
1180 int len; /* its bit length */
1181 {
1182 register unsigned res = 0;
1183 do {
1184 res |= code & 1;
1185 code >>= 1, res <<= 1;
1186 } while (--len > 0);
1187 return res >> 1;
1188 }
1189
1190 /* ===========================================================================
1191 * Flush the bit buffer, keeping at most 7 bits in it.
1192 */
1193 local void bi_flush(s)
1194 deflate_state *s;
1195 {
1196 if (s->bi_valid == 16) {
1197 put_short(s, s->bi_buf);
1198 s->bi_buf = 0;
1199 s->bi_valid = 0;
1200 } else if (s->bi_valid >= 8) {
1201 put_byte(s, (Byte)s->bi_buf);
1202 s->bi_buf >>= 8;
1203 s->bi_valid -= 8;
1204 }
1205 }
1206
1207 /* ===========================================================================
1208 * Flush the bit buffer and align the output on a byte boundary
1209 */
1210 local void bi_windup(s)
1211 deflate_state *s;
1212 {
1213 if (s->bi_valid > 8) {
1214 put_short(s, s->bi_buf);
1215 } else if (s->bi_valid > 0) {
1216 put_byte(s, (Byte)s->bi_buf);
1217 }
1218 s->bi_buf = 0;
1219 s->bi_valid = 0;
1220 #ifdef DEBUG
1221 s->bits_sent = (s->bits_sent+7) & ~7;
1222 #endif
1223 }
1224
1225 /* ===========================================================================
1226 * Copy a stored block, storing first the length and its
1227 * one's complement if requested.
1228 */
1229 local void copy_block(s, buf, len, header)
1230 deflate_state *s;
1231 charf *buf; /* the input data */
1232 unsigned len; /* its length */
1233 int header; /* true if block header must be written */
1234 {
1235 bi_windup(s); /* align on byte boundary */
1236
1237 if (header) {
1238 put_short(s, (ush)len);
1239 put_short(s, (ush)~len);
1240 #ifdef DEBUG
1241 s->bits_sent += 2*16;
1242 #endif
1243 }
1244 #ifdef DEBUG
1245 s->bits_sent += (ulg)len<<3;
1246 #endif
1247 while (len--) {
1248 put_byte(s, *buf++);
1249 }
1250 }