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51#include <linux/module.h>
52#include <linux/zutil.h>
53#include "defutil.h"
54
55
56
57
58
59typedef enum {
60 need_more,
61 block_done,
62 finish_started,
63 finish_done
64} block_state;
65
66typedef block_state (*compress_func) (deflate_state *s, int flush);
67
68
69static void fill_window (deflate_state *s);
70static block_state deflate_stored (deflate_state *s, int flush);
71static block_state deflate_fast (deflate_state *s, int flush);
72static block_state deflate_slow (deflate_state *s, int flush);
73static void lm_init (deflate_state *s);
74static void putShortMSB (deflate_state *s, uInt b);
75static void flush_pending (z_streamp strm);
76static int read_buf (z_streamp strm, Byte *buf, unsigned size);
77static uInt longest_match (deflate_state *s, IPos cur_match);
78
79#ifdef DEBUG_ZLIB
80static void check_match (deflate_state *s, IPos start, IPos match,
81 int length);
82#endif
83
84
85
86
87
88#define NIL 0
89
90
91#ifndef TOO_FAR
92# define TOO_FAR 4096
93#endif
94
95
96#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
97
98
99
100
101
102
103
104
105
106typedef struct config_s {
107 ush good_length;
108 ush max_lazy;
109 ush nice_length;
110 ush max_chain;
111 compress_func func;
112} config;
113
114static const config configuration_table[10] = {
115
116 {0, 0, 0, 0, deflate_stored},
117 {4, 4, 8, 4, deflate_fast},
118 {4, 5, 16, 8, deflate_fast},
119 {4, 6, 32, 32, deflate_fast},
120
121 {4, 4, 16, 16, deflate_slow},
122 {8, 16, 32, 32, deflate_slow},
123 {8, 16, 128, 128, deflate_slow},
124 {8, 32, 128, 256, deflate_slow},
125 {32, 128, 258, 1024, deflate_slow},
126 {32, 258, 258, 4096, deflate_slow}};
127
128
129
130
131
132
133#define EQUAL 0
134
135
136
137
138
139
140
141
142#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
143
144
145
146
147
148
149
150
151
152
153#define INSERT_STRING(s, str, match_head) \
154 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
155 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
156 s->head[s->ins_h] = (Pos)(str))
157
158
159
160
161
162#define CLEAR_HASH(s) \
163 s->head[s->hash_size-1] = NIL; \
164 memset((char *)s->head, 0, (unsigned)(s->hash_size-1)*sizeof(*s->head));
165
166
167int zlib_deflateInit2(
168 z_streamp strm,
169 int level,
170 int method,
171 int windowBits,
172 int memLevel,
173 int strategy
174)
175{
176 deflate_state *s;
177 int noheader = 0;
178 deflate_workspace *mem;
179
180 ush *overlay;
181
182
183
184
185 if (strm == NULL) return Z_STREAM_ERROR;
186
187 strm->msg = NULL;
188
189 if (level == Z_DEFAULT_COMPRESSION) level = 6;
190
191 mem = (deflate_workspace *) strm->workspace;
192
193 if (windowBits < 0) {
194 noheader = 1;
195 windowBits = -windowBits;
196 }
197 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
198 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
199 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
200 return Z_STREAM_ERROR;
201 }
202 s = (deflate_state *) &(mem->deflate_memory);
203 strm->state = (struct internal_state *)s;
204 s->strm = strm;
205
206 s->noheader = noheader;
207 s->w_bits = windowBits;
208 s->w_size = 1 << s->w_bits;
209 s->w_mask = s->w_size - 1;
210
211 s->hash_bits = memLevel + 7;
212 s->hash_size = 1 << s->hash_bits;
213 s->hash_mask = s->hash_size - 1;
214 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
215
216 s->window = (Byte *) mem->window_memory;
217 s->prev = (Pos *) mem->prev_memory;
218 s->head = (Pos *) mem->head_memory;
219
220 s->lit_bufsize = 1 << (memLevel + 6);
221
222 overlay = (ush *) mem->overlay_memory;
223 s->pending_buf = (uch *) overlay;
224 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
225
226 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
227 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
228
229 s->level = level;
230 s->strategy = strategy;
231 s->method = (Byte)method;
232
233 return zlib_deflateReset(strm);
234}
235
236
237#if 0
238int zlib_deflateSetDictionary(
239 z_streamp strm,
240 const Byte *dictionary,
241 uInt dictLength
242)
243{
244 deflate_state *s;
245 uInt length = dictLength;
246 uInt n;
247 IPos hash_head = 0;
248
249 if (strm == NULL || strm->state == NULL || dictionary == NULL)
250 return Z_STREAM_ERROR;
251
252 s = (deflate_state *) strm->state;
253 if (s->status != INIT_STATE) return Z_STREAM_ERROR;
254
255 strm->adler = zlib_adler32(strm->adler, dictionary, dictLength);
256
257 if (length < MIN_MATCH) return Z_OK;
258 if (length > MAX_DIST(s)) {
259 length = MAX_DIST(s);
260#ifndef USE_DICT_HEAD
261 dictionary += dictLength - length;
262#endif
263 }
264 memcpy((char *)s->window, dictionary, length);
265 s->strstart = length;
266 s->block_start = (long)length;
267
268
269
270
271
272 s->ins_h = s->window[0];
273 UPDATE_HASH(s, s->ins_h, s->window[1]);
274 for (n = 0; n <= length - MIN_MATCH; n++) {
275 INSERT_STRING(s, n, hash_head);
276 }
277 if (hash_head) hash_head = 0;
278 return Z_OK;
279}
280#endif
281
282
283int zlib_deflateReset(
284 z_streamp strm
285)
286{
287 deflate_state *s;
288
289 if (strm == NULL || strm->state == NULL)
290 return Z_STREAM_ERROR;
291
292 strm->total_in = strm->total_out = 0;
293 strm->msg = NULL;
294 strm->data_type = Z_UNKNOWN;
295
296 s = (deflate_state *)strm->state;
297 s->pending = 0;
298 s->pending_out = s->pending_buf;
299
300 if (s->noheader < 0) {
301 s->noheader = 0;
302 }
303 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
304 strm->adler = 1;
305 s->last_flush = Z_NO_FLUSH;
306
307 zlib_tr_init(s);
308 lm_init(s);
309
310 return Z_OK;
311}
312
313
314#if 0
315int zlib_deflateParams(
316 z_streamp strm,
317 int level,
318 int strategy
319)
320{
321 deflate_state *s;
322 compress_func func;
323 int err = Z_OK;
324
325 if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
326 s = (deflate_state *) strm->state;
327
328 if (level == Z_DEFAULT_COMPRESSION) {
329 level = 6;
330 }
331 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
332 return Z_STREAM_ERROR;
333 }
334 func = configuration_table[s->level].func;
335
336 if (func != configuration_table[level].func && strm->total_in != 0) {
337
338 err = zlib_deflate(strm, Z_PARTIAL_FLUSH);
339 }
340 if (s->level != level) {
341 s->level = level;
342 s->max_lazy_match = configuration_table[level].max_lazy;
343 s->good_match = configuration_table[level].good_length;
344 s->nice_match = configuration_table[level].nice_length;
345 s->max_chain_length = configuration_table[level].max_chain;
346 }
347 s->strategy = strategy;
348 return err;
349}
350#endif
351
352
353
354
355
356
357static void putShortMSB(
358 deflate_state *s,
359 uInt b
360)
361{
362 put_byte(s, (Byte)(b >> 8));
363 put_byte(s, (Byte)(b & 0xff));
364}
365
366
367
368
369
370
371
372static void flush_pending(
373 z_streamp strm
374)
375{
376 deflate_state *s = (deflate_state *) strm->state;
377 unsigned len = s->pending;
378
379 if (len > strm->avail_out) len = strm->avail_out;
380 if (len == 0) return;
381
382 if (strm->next_out != NULL) {
383 memcpy(strm->next_out, s->pending_out, len);
384 strm->next_out += len;
385 }
386 s->pending_out += len;
387 strm->total_out += len;
388 strm->avail_out -= len;
389 s->pending -= len;
390 if (s->pending == 0) {
391 s->pending_out = s->pending_buf;
392 }
393}
394
395
396int zlib_deflate(
397 z_streamp strm,
398 int flush
399)
400{
401 int old_flush;
402 deflate_state *s;
403
404 if (strm == NULL || strm->state == NULL ||
405 flush > Z_FINISH || flush < 0) {
406 return Z_STREAM_ERROR;
407 }
408 s = (deflate_state *) strm->state;
409
410 if ((strm->next_in == NULL && strm->avail_in != 0) ||
411 (s->status == FINISH_STATE && flush != Z_FINISH)) {
412 return Z_STREAM_ERROR;
413 }
414 if (strm->avail_out == 0) return Z_BUF_ERROR;
415
416 s->strm = strm;
417 old_flush = s->last_flush;
418 s->last_flush = flush;
419
420
421 if (s->status == INIT_STATE) {
422
423 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
424 uInt level_flags = (s->level-1) >> 1;
425
426 if (level_flags > 3) level_flags = 3;
427 header |= (level_flags << 6);
428 if (s->strstart != 0) header |= PRESET_DICT;
429 header += 31 - (header % 31);
430
431 s->status = BUSY_STATE;
432 putShortMSB(s, header);
433
434
435 if (s->strstart != 0) {
436 putShortMSB(s, (uInt)(strm->adler >> 16));
437 putShortMSB(s, (uInt)(strm->adler & 0xffff));
438 }
439 strm->adler = 1L;
440 }
441
442
443 if (s->pending != 0) {
444 flush_pending(strm);
445 if (strm->avail_out == 0) {
446
447
448
449
450
451
452 s->last_flush = -1;
453 return Z_OK;
454 }
455
456
457
458
459
460 } else if (strm->avail_in == 0 && flush <= old_flush &&
461 flush != Z_FINISH) {
462 return Z_BUF_ERROR;
463 }
464
465
466 if (s->status == FINISH_STATE && strm->avail_in != 0) {
467 return Z_BUF_ERROR;
468 }
469
470
471
472 if (strm->avail_in != 0 || s->lookahead != 0 ||
473 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
474 block_state bstate;
475
476 bstate = (*(configuration_table[s->level].func))(s, flush);
477
478 if (bstate == finish_started || bstate == finish_done) {
479 s->status = FINISH_STATE;
480 }
481 if (bstate == need_more || bstate == finish_started) {
482 if (strm->avail_out == 0) {
483 s->last_flush = -1;
484 }
485 return Z_OK;
486
487
488
489
490
491
492
493 }
494 if (bstate == block_done) {
495 if (flush == Z_PARTIAL_FLUSH) {
496 zlib_tr_align(s);
497 } else if (flush == Z_PACKET_FLUSH) {
498
499
500 zlib_tr_stored_type_only(s);
501 } else {
502 zlib_tr_stored_block(s, (char*)0, 0L, 0);
503
504
505
506 if (flush == Z_FULL_FLUSH) {
507 CLEAR_HASH(s);
508 }
509 }
510 flush_pending(strm);
511 if (strm->avail_out == 0) {
512 s->last_flush = -1;
513 return Z_OK;
514 }
515 }
516 }
517 Assert(strm->avail_out > 0, "bug2");
518
519 if (flush != Z_FINISH) return Z_OK;
520 if (s->noheader) return Z_STREAM_END;
521
522
523 putShortMSB(s, (uInt)(strm->adler >> 16));
524 putShortMSB(s, (uInt)(strm->adler & 0xffff));
525 flush_pending(strm);
526
527
528
529 s->noheader = -1;
530 return s->pending != 0 ? Z_OK : Z_STREAM_END;
531}
532
533
534int zlib_deflateEnd(
535 z_streamp strm
536)
537{
538 int status;
539 deflate_state *s;
540
541 if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
542 s = (deflate_state *) strm->state;
543
544 status = s->status;
545 if (status != INIT_STATE && status != BUSY_STATE &&
546 status != FINISH_STATE) {
547 return Z_STREAM_ERROR;
548 }
549
550 strm->state = NULL;
551
552 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
553}
554
555
556
557
558#if 0
559int zlib_deflateCopy (
560 z_streamp dest,
561 z_streamp source
562)
563{
564#ifdef MAXSEG_64K
565 return Z_STREAM_ERROR;
566#else
567 deflate_state *ds;
568 deflate_state *ss;
569 ush *overlay;
570 deflate_workspace *mem;
571
572
573 if (source == NULL || dest == NULL || source->state == NULL) {
574 return Z_STREAM_ERROR;
575 }
576
577 ss = (deflate_state *) source->state;
578
579 *dest = *source;
580
581 mem = (deflate_workspace *) dest->workspace;
582
583 ds = &(mem->deflate_memory);
584
585 dest->state = (struct internal_state *) ds;
586 *ds = *ss;
587 ds->strm = dest;
588
589 ds->window = (Byte *) mem->window_memory;
590 ds->prev = (Pos *) mem->prev_memory;
591 ds->head = (Pos *) mem->head_memory;
592 overlay = (ush *) mem->overlay_memory;
593 ds->pending_buf = (uch *) overlay;
594
595 memcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
596 memcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
597 memcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
598 memcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
599
600 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
601 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
602 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
603
604 ds->l_desc.dyn_tree = ds->dyn_ltree;
605 ds->d_desc.dyn_tree = ds->dyn_dtree;
606 ds->bl_desc.dyn_tree = ds->bl_tree;
607
608 return Z_OK;
609#endif
610}
611#endif
612
613
614
615
616
617
618
619
620static int read_buf(
621 z_streamp strm,
622 Byte *buf,
623 unsigned size
624)
625{
626 unsigned len = strm->avail_in;
627
628 if (len > size) len = size;
629 if (len == 0) return 0;
630
631 strm->avail_in -= len;
632
633 if (!((deflate_state *)(strm->state))->noheader) {
634 strm->adler = zlib_adler32(strm->adler, strm->next_in, len);
635 }
636 memcpy(buf, strm->next_in, len);
637 strm->next_in += len;
638 strm->total_in += len;
639
640 return (int)len;
641}
642
643
644
645
646static void lm_init(
647 deflate_state *s
648)
649{
650 s->window_size = (ulg)2L*s->w_size;
651
652 CLEAR_HASH(s);
653
654
655
656 s->max_lazy_match = configuration_table[s->level].max_lazy;
657 s->good_match = configuration_table[s->level].good_length;
658 s->nice_match = configuration_table[s->level].nice_length;
659 s->max_chain_length = configuration_table[s->level].max_chain;
660
661 s->strstart = 0;
662 s->block_start = 0L;
663 s->lookahead = 0;
664 s->match_length = s->prev_length = MIN_MATCH-1;
665 s->match_available = 0;
666 s->ins_h = 0;
667}
668
669
670
671
672
673
674
675
676
677
678
679
680
681static uInt longest_match(
682 deflate_state *s,
683 IPos cur_match
684)
685{
686 unsigned chain_length = s->max_chain_length;
687 register Byte *scan = s->window + s->strstart;
688 register Byte *match;
689 register int len;
690 int best_len = s->prev_length;
691 int nice_match = s->nice_match;
692 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
693 s->strstart - (IPos)MAX_DIST(s) : NIL;
694
695
696
697 Pos *prev = s->prev;
698 uInt wmask = s->w_mask;
699
700#ifdef UNALIGNED_OK
701
702
703
704 register Byte *strend = s->window + s->strstart + MAX_MATCH - 1;
705 register ush scan_start = *(ush*)scan;
706 register ush scan_end = *(ush*)(scan+best_len-1);
707#else
708 register Byte *strend = s->window + s->strstart + MAX_MATCH;
709 register Byte scan_end1 = scan[best_len-1];
710 register Byte scan_end = scan[best_len];
711#endif
712
713
714
715
716 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
717
718
719 if (s->prev_length >= s->good_match) {
720 chain_length >>= 2;
721 }
722
723
724
725 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
726
727 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
728
729 do {
730 Assert(cur_match < s->strstart, "no future");
731 match = s->window + cur_match;
732
733
734
735
736#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
737
738
739
740 if (*(ush*)(match+best_len-1) != scan_end ||
741 *(ush*)match != scan_start) continue;
742
743
744
745
746
747
748
749
750
751
752 Assert(scan[2] == match[2], "scan[2]?");
753 scan++, match++;
754 do {
755 } while (*(ush*)(scan+=2) == *(ush*)(match+=2) &&
756 *(ush*)(scan+=2) == *(ush*)(match+=2) &&
757 *(ush*)(scan+=2) == *(ush*)(match+=2) &&
758 *(ush*)(scan+=2) == *(ush*)(match+=2) &&
759 scan < strend);
760
761
762
763 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
764 if (*scan == *match) scan++;
765
766 len = (MAX_MATCH - 1) - (int)(strend-scan);
767 scan = strend - (MAX_MATCH-1);
768
769#else
770
771 if (match[best_len] != scan_end ||
772 match[best_len-1] != scan_end1 ||
773 *match != *scan ||
774 *++match != scan[1]) continue;
775
776
777
778
779
780
781
782 scan += 2, match++;
783 Assert(*scan == *match, "match[2]?");
784
785
786
787
788 do {
789 } while (*++scan == *++match && *++scan == *++match &&
790 *++scan == *++match && *++scan == *++match &&
791 *++scan == *++match && *++scan == *++match &&
792 *++scan == *++match && *++scan == *++match &&
793 scan < strend);
794
795 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
796
797 len = MAX_MATCH - (int)(strend - scan);
798 scan = strend - MAX_MATCH;
799
800#endif
801
802 if (len > best_len) {
803 s->match_start = cur_match;
804 best_len = len;
805 if (len >= nice_match) break;
806#ifdef UNALIGNED_OK
807 scan_end = *(ush*)(scan+best_len-1);
808#else
809 scan_end1 = scan[best_len-1];
810 scan_end = scan[best_len];
811#endif
812 }
813 } while ((cur_match = prev[cur_match & wmask]) > limit
814 && --chain_length != 0);
815
816 if ((uInt)best_len <= s->lookahead) return best_len;
817 return s->lookahead;
818}
819
820#ifdef DEBUG_ZLIB
821
822
823
824static void check_match(
825 deflate_state *s,
826 IPos start,
827 IPos match,
828 int length
829)
830{
831
832 if (memcmp((char *)s->window + match,
833 (char *)s->window + start, length) != EQUAL) {
834 fprintf(stderr, " start %u, match %u, length %d\n",
835 start, match, length);
836 do {
837 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
838 } while (--length != 0);
839 z_error("invalid match");
840 }
841 if (z_verbose > 1) {
842 fprintf(stderr,"\\[%d,%d]", start-match, length);
843 do { putc(s->window[start++], stderr); } while (--length != 0);
844 }
845}
846#else
847# define check_match(s, start, match, length)
848#endif
849
850
851
852
853
854
855
856
857
858
859
860static void fill_window(
861 deflate_state *s
862)
863{
864 register unsigned n, m;
865 register Pos *p;
866 unsigned more;
867 uInt wsize = s->w_size;
868
869 do {
870 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
871
872
873 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
874 more = wsize;
875
876 } else if (more == (unsigned)(-1)) {
877
878
879
880 more--;
881
882
883
884
885 } else if (s->strstart >= wsize+MAX_DIST(s)) {
886
887 memcpy((char *)s->window, (char *)s->window+wsize,
888 (unsigned)wsize);
889 s->match_start -= wsize;
890 s->strstart -= wsize;
891 s->block_start -= (long) wsize;
892
893
894
895
896
897
898
899 n = s->hash_size;
900 p = &s->head[n];
901 do {
902 m = *--p;
903 *p = (Pos)(m >= wsize ? m-wsize : NIL);
904 } while (--n);
905
906 n = wsize;
907 p = &s->prev[n];
908 do {
909 m = *--p;
910 *p = (Pos)(m >= wsize ? m-wsize : NIL);
911
912
913
914 } while (--n);
915 more += wsize;
916 }
917 if (s->strm->avail_in == 0) return;
918
919
920
921
922
923
924
925
926
927
928
929
930 Assert(more >= 2, "more < 2");
931
932 n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
933 s->lookahead += n;
934
935
936 if (s->lookahead >= MIN_MATCH) {
937 s->ins_h = s->window[s->strstart];
938 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
939#if MIN_MATCH != 3
940 Call UPDATE_HASH() MIN_MATCH-3 more times
941#endif
942 }
943
944
945
946
947 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
948}
949
950
951
952
953
954#define FLUSH_BLOCK_ONLY(s, eof) { \
955 zlib_tr_flush_block(s, (s->block_start >= 0L ? \
956 (char *)&s->window[(unsigned)s->block_start] : \
957 NULL), \
958 (ulg)((long)s->strstart - s->block_start), \
959 (eof)); \
960 s->block_start = s->strstart; \
961 flush_pending(s->strm); \
962 Tracev((stderr,"[FLUSH]")); \
963}
964
965
966#define FLUSH_BLOCK(s, eof) { \
967 FLUSH_BLOCK_ONLY(s, eof); \
968 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
969}
970
971
972
973
974
975
976
977
978
979
980static block_state deflate_stored(
981 deflate_state *s,
982 int flush
983)
984{
985
986
987
988 ulg max_block_size = 0xffff;
989 ulg max_start;
990
991 if (max_block_size > s->pending_buf_size - 5) {
992 max_block_size = s->pending_buf_size - 5;
993 }
994
995
996 for (;;) {
997
998 if (s->lookahead <= 1) {
999
1000 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1001 s->block_start >= (long)s->w_size, "slide too late");
1002
1003 fill_window(s);
1004 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1005
1006 if (s->lookahead == 0) break;
1007 }
1008 Assert(s->block_start >= 0L, "block gone");
1009
1010 s->strstart += s->lookahead;
1011 s->lookahead = 0;
1012
1013
1014 max_start = s->block_start + max_block_size;
1015 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1016
1017 s->lookahead = (uInt)(s->strstart - max_start);
1018 s->strstart = (uInt)max_start;
1019 FLUSH_BLOCK(s, 0);
1020 }
1021
1022
1023
1024 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1025 FLUSH_BLOCK(s, 0);
1026 }
1027 }
1028 FLUSH_BLOCK(s, flush == Z_FINISH);
1029 return flush == Z_FINISH ? finish_done : block_done;
1030}
1031
1032
1033
1034
1035
1036
1037
1038
1039static block_state deflate_fast(
1040 deflate_state *s,
1041 int flush
1042)
1043{
1044 IPos hash_head = NIL;
1045 int bflush;
1046
1047 for (;;) {
1048
1049
1050
1051
1052
1053 if (s->lookahead < MIN_LOOKAHEAD) {
1054 fill_window(s);
1055 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1056 return need_more;
1057 }
1058 if (s->lookahead == 0) break;
1059 }
1060
1061
1062
1063
1064 if (s->lookahead >= MIN_MATCH) {
1065 INSERT_STRING(s, s->strstart, hash_head);
1066 }
1067
1068
1069
1070
1071 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1072
1073
1074
1075
1076 if (s->strategy != Z_HUFFMAN_ONLY) {
1077 s->match_length = longest_match (s, hash_head);
1078 }
1079
1080 }
1081 if (s->match_length >= MIN_MATCH) {
1082 check_match(s, s->strstart, s->match_start, s->match_length);
1083
1084 bflush = zlib_tr_tally(s, s->strstart - s->match_start,
1085 s->match_length - MIN_MATCH);
1086
1087 s->lookahead -= s->match_length;
1088
1089
1090
1091
1092 if (s->match_length <= s->max_insert_length &&
1093 s->lookahead >= MIN_MATCH) {
1094 s->match_length--;
1095 do {
1096 s->strstart++;
1097 INSERT_STRING(s, s->strstart, hash_head);
1098
1099
1100
1101 } while (--s->match_length != 0);
1102 s->strstart++;
1103 } else {
1104 s->strstart += s->match_length;
1105 s->match_length = 0;
1106 s->ins_h = s->window[s->strstart];
1107 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1108#if MIN_MATCH != 3
1109 Call UPDATE_HASH() MIN_MATCH-3 more times
1110#endif
1111
1112
1113
1114 }
1115 } else {
1116
1117 Tracevv((stderr,"%c", s->window[s->strstart]));
1118 bflush = zlib_tr_tally (s, 0, s->window[s->strstart]);
1119 s->lookahead--;
1120 s->strstart++;
1121 }
1122 if (bflush) FLUSH_BLOCK(s, 0);
1123 }
1124 FLUSH_BLOCK(s, flush == Z_FINISH);
1125 return flush == Z_FINISH ? finish_done : block_done;
1126}
1127
1128
1129
1130
1131
1132
1133static block_state deflate_slow(
1134 deflate_state *s,
1135 int flush
1136)
1137{
1138 IPos hash_head = NIL;
1139 int bflush;
1140
1141
1142 for (;;) {
1143
1144
1145
1146
1147
1148 if (s->lookahead < MIN_LOOKAHEAD) {
1149 fill_window(s);
1150 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1151 return need_more;
1152 }
1153 if (s->lookahead == 0) break;
1154 }
1155
1156
1157
1158
1159 if (s->lookahead >= MIN_MATCH) {
1160 INSERT_STRING(s, s->strstart, hash_head);
1161 }
1162
1163
1164
1165 s->prev_length = s->match_length, s->prev_match = s->match_start;
1166 s->match_length = MIN_MATCH-1;
1167
1168 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1169 s->strstart - hash_head <= MAX_DIST(s)) {
1170
1171
1172
1173
1174 if (s->strategy != Z_HUFFMAN_ONLY) {
1175 s->match_length = longest_match (s, hash_head);
1176 }
1177
1178
1179 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1180 (s->match_length == MIN_MATCH &&
1181 s->strstart - s->match_start > TOO_FAR))) {
1182
1183
1184
1185
1186 s->match_length = MIN_MATCH-1;
1187 }
1188 }
1189
1190
1191
1192 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1193 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1194
1195
1196 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1197
1198 bflush = zlib_tr_tally(s, s->strstart -1 - s->prev_match,
1199 s->prev_length - MIN_MATCH);
1200
1201
1202
1203
1204
1205
1206 s->lookahead -= s->prev_length-1;
1207 s->prev_length -= 2;
1208 do {
1209 if (++s->strstart <= max_insert) {
1210 INSERT_STRING(s, s->strstart, hash_head);
1211 }
1212 } while (--s->prev_length != 0);
1213 s->match_available = 0;
1214 s->match_length = MIN_MATCH-1;
1215 s->strstart++;
1216
1217 if (bflush) FLUSH_BLOCK(s, 0);
1218
1219 } else if (s->match_available) {
1220
1221
1222
1223
1224 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1225 if (zlib_tr_tally (s, 0, s->window[s->strstart-1])) {
1226 FLUSH_BLOCK_ONLY(s, 0);
1227 }
1228 s->strstart++;
1229 s->lookahead--;
1230 if (s->strm->avail_out == 0) return need_more;
1231 } else {
1232
1233
1234
1235 s->match_available = 1;
1236 s->strstart++;
1237 s->lookahead--;
1238 }
1239 }
1240 Assert (flush != Z_NO_FLUSH, "no flush?");
1241 if (s->match_available) {
1242 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1243 zlib_tr_tally (s, 0, s->window[s->strstart-1]);
1244 s->match_available = 0;
1245 }
1246 FLUSH_BLOCK(s, flush == Z_FINISH);
1247 return flush == Z_FINISH ? finish_done : block_done;
1248}
1249
1250int zlib_deflate_workspacesize(void)
1251{
1252 return sizeof(deflate_workspace);
1253}
1254