main
1import * as utils from "../utils/common.js";
2import * as trees from "./trees.js";
3import adler32 from "./adler32.js";
4import crc32 from "./crc32.js";
5import msg from "./messages.js";
6
7/* Public constants ==========================================================*/
8/* ===========================================================================*/
9
10
11/* Allowed flush values; see deflate() and inflate() below for details */
12export const Z_NO_FLUSH = 0;
13export const Z_PARTIAL_FLUSH = 1;
14//export const Z_SYNC_FLUSH = 2;
15export const Z_FULL_FLUSH = 3;
16export const Z_FINISH = 4;
17export const Z_BLOCK = 5;
18//export const Z_TREES = 6;
19
20
21/* Return codes for the compression/decompression functions. Negative values
22 * are errors, positive values are used for special but normal events.
23 */
24export const Z_OK = 0;
25export const Z_STREAM_END = 1;
26//export const Z_NEED_DICT = 2;
27//export const Z_ERRNO = -1;
28export const Z_STREAM_ERROR = -2;
29export const Z_DATA_ERROR = -3;
30//export const Z_MEM_ERROR = -4;
31export const Z_BUF_ERROR = -5;
32//export const Z_VERSION_ERROR = -6;
33
34
35/* compression levels */
36//export const Z_NO_COMPRESSION = 0;
37//export const Z_BEST_SPEED = 1;
38//export const Z_BEST_COMPRESSION = 9;
39export const Z_DEFAULT_COMPRESSION = -1;
40
41
42export const Z_FILTERED = 1;
43export const Z_HUFFMAN_ONLY = 2;
44export const Z_RLE = 3;
45export const Z_FIXED = 4;
46export const Z_DEFAULT_STRATEGY = 0;
47
48/* Possible values of the data_type field (though see inflate()) */
49//export const Z_BINARY = 0;
50//export const Z_TEXT = 1;
51//export const Z_ASCII = 1; // = Z_TEXT
52export const Z_UNKNOWN = 2;
53
54
55/* The deflate compression method */
56export const Z_DEFLATED = 8;
57
58/*============================================================================*/
59
60
61var MAX_MEM_LEVEL = 9;
62/* Maximum value for memLevel in deflateInit2 */
63var MAX_WBITS = 15;
64/* 32K LZ77 window */
65var DEF_MEM_LEVEL = 8;
66
67
68var LENGTH_CODES = 29;
69/* number of length codes, not counting the special END_BLOCK code */
70var LITERALS = 256;
71/* number of literal bytes 0..255 */
72var L_CODES = LITERALS + 1 + LENGTH_CODES;
73/* number of Literal or Length codes, including the END_BLOCK code */
74var D_CODES = 30;
75/* number of distance codes */
76var BL_CODES = 19;
77/* number of codes used to transfer the bit lengths */
78var HEAP_SIZE = 2 * L_CODES + 1;
79/* maximum heap size */
80var MAX_BITS = 15;
81/* All codes must not exceed MAX_BITS bits */
82
83var MIN_MATCH = 3;
84var MAX_MATCH = 258;
85var MIN_LOOKAHEAD = (MAX_MATCH + MIN_MATCH + 1);
86
87var PRESET_DICT = 0x20;
88
89var INIT_STATE = 42;
90var EXTRA_STATE = 69;
91var NAME_STATE = 73;
92var COMMENT_STATE = 91;
93var HCRC_STATE = 103;
94var BUSY_STATE = 113;
95var FINISH_STATE = 666;
96
97var BS_NEED_MORE = 1; /* block not completed, need more input or more output */
98var BS_BLOCK_DONE = 2; /* block flush performed */
99var BS_FINISH_STARTED = 3; /* finish started, need only more output at next deflate */
100var BS_FINISH_DONE = 4; /* finish done, accept no more input or output */
101
102var OS_CODE = 0x03; // Unix :) . Don't detect, use this default.
103
104function err(strm, errorCode) {
105 strm.msg = msg[errorCode];
106 return errorCode;
107}
108
109function rank(f) {
110 return ((f) << 1) - ((f) > 4 ? 9 : 0);
111}
112
113function zero(buf) { var len = buf.length; while (--len >= 0) { buf[len] = 0; } }
114
115
116/* =========================================================================
117 * Flush as much pending output as possible. All deflate() output goes
118 * through this function so some applications may wish to modify it
119 * to avoid allocating a large strm->output buffer and copying into it.
120 * (See also read_buf()).
121 */
122function flush_pending(strm) {
123 var s = strm.state;
124
125 //_tr_flush_bits(s);
126 var len = s.pending;
127 if (len > strm.avail_out) {
128 len = strm.avail_out;
129 }
130 if (len === 0) { return; }
131
132 utils.arraySet(strm.output, s.pending_buf, s.pending_out, len, strm.next_out);
133 strm.next_out += len;
134 s.pending_out += len;
135 strm.total_out += len;
136 strm.avail_out -= len;
137 s.pending -= len;
138 if (s.pending === 0) {
139 s.pending_out = 0;
140 }
141}
142
143
144function flush_block_only(s, last) {
145 trees._tr_flush_block(s, (s.block_start >= 0 ? s.block_start : -1), s.strstart - s.block_start, last);
146 s.block_start = s.strstart;
147 flush_pending(s.strm);
148}
149
150
151function put_byte(s, b) {
152 s.pending_buf[s.pending++] = b;
153}
154
155
156/* =========================================================================
157 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
158 * IN assertion: the stream state is correct and there is enough room in
159 * pending_buf.
160 */
161function putShortMSB(s, b) {
162// put_byte(s, (Byte)(b >> 8));
163// put_byte(s, (Byte)(b & 0xff));
164 s.pending_buf[s.pending++] = (b >>> 8) & 0xff;
165 s.pending_buf[s.pending++] = b & 0xff;
166}
167
168
169/* ===========================================================================
170 * Read a new buffer from the current input stream, update the adler32
171 * and total number of bytes read. All deflate() input goes through
172 * this function so some applications may wish to modify it to avoid
173 * allocating a large strm->input buffer and copying from it.
174 * (See also flush_pending()).
175 */
176function read_buf(strm, buf, start, size) {
177 var len = strm.avail_in;
178
179 if (len > size) { len = size; }
180 if (len === 0) { return 0; }
181
182 strm.avail_in -= len;
183
184 // zmemcpy(buf, strm->next_in, len);
185 utils.arraySet(buf, strm.input, strm.next_in, len, start);
186 if (strm.state.wrap === 1) {
187 strm.adler = adler32(strm.adler, buf, len, start);
188 }
189
190 else if (strm.state.wrap === 2) {
191 strm.adler = crc32(strm.adler, buf, len, start);
192 }
193
194 strm.next_in += len;
195 strm.total_in += len;
196
197 return len;
198}
199
200
201/* ===========================================================================
202 * Set match_start to the longest match starting at the given string and
203 * return its length. Matches shorter or equal to prev_length are discarded,
204 * in which case the result is equal to prev_length and match_start is
205 * garbage.
206 * IN assertions: cur_match is the head of the hash chain for the current
207 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
208 * OUT assertion: the match length is not greater than s->lookahead.
209 */
210function longest_match(s, cur_match) {
211 var chain_length = s.max_chain_length; /* max hash chain length */
212 var scan = s.strstart; /* current string */
213 var match; /* matched string */
214 var len; /* length of current match */
215 var best_len = s.prev_length; /* best match length so far */
216 var nice_match = s.nice_match; /* stop if match long enough */
217 var limit = (s.strstart > (s.w_size - MIN_LOOKAHEAD)) ?
218 s.strstart - (s.w_size - MIN_LOOKAHEAD) : 0/*NIL*/;
219
220 var _win = s.window; // shortcut
221
222 var wmask = s.w_mask;
223 var prev = s.prev;
224
225 /* Stop when cur_match becomes <= limit. To simplify the code,
226 * we prevent matches with the string of window index 0.
227 */
228
229 var strend = s.strstart + MAX_MATCH;
230 var scan_end1 = _win[scan + best_len - 1];
231 var scan_end = _win[scan + best_len];
232
233 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
234 * It is easy to get rid of this optimization if necessary.
235 */
236 // Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
237
238 /* Do not waste too much time if we already have a good match: */
239 if (s.prev_length >= s.good_match) {
240 chain_length >>= 2;
241 }
242 /* Do not look for matches beyond the end of the input. This is necessary
243 * to make deflate deterministic.
244 */
245 if (nice_match > s.lookahead) { nice_match = s.lookahead; }
246
247 // Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
248
249 do {
250 // Assert(cur_match < s->strstart, "no future");
251 match = cur_match;
252
253 /* Skip to next match if the match length cannot increase
254 * or if the match length is less than 2. Note that the checks below
255 * for insufficient lookahead only occur occasionally for performance
256 * reasons. Therefore uninitialized memory will be accessed, and
257 * conditional jumps will be made that depend on those values.
258 * However the length of the match is limited to the lookahead, so
259 * the output of deflate is not affected by the uninitialized values.
260 */
261
262 if (_win[match + best_len] !== scan_end ||
263 _win[match + best_len - 1] !== scan_end1 ||
264 _win[match] !== _win[scan] ||
265 _win[++match] !== _win[scan + 1]) {
266 continue;
267 }
268
269 /* The check at best_len-1 can be removed because it will be made
270 * again later. (This heuristic is not always a win.)
271 * It is not necessary to compare scan[2] and match[2] since they
272 * are always equal when the other bytes match, given that
273 * the hash keys are equal and that HASH_BITS >= 8.
274 */
275 scan += 2;
276 match++;
277 // Assert(*scan == *match, "match[2]?");
278
279 /* We check for insufficient lookahead only every 8th comparison;
280 * the 256th check will be made at strstart+258.
281 */
282 do {
283 // Do nothing
284 } while (_win[++scan] === _win[++match] && _win[++scan] === _win[++match] &&
285 _win[++scan] === _win[++match] && _win[++scan] === _win[++match] &&
286 _win[++scan] === _win[++match] && _win[++scan] === _win[++match] &&
287 _win[++scan] === _win[++match] && _win[++scan] === _win[++match] &&
288 scan < strend);
289
290 // Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
291
292 len = MAX_MATCH - (strend - scan);
293 scan = strend - MAX_MATCH;
294
295 if (len > best_len) {
296 s.match_start = cur_match;
297 best_len = len;
298 if (len >= nice_match) {
299 break;
300 }
301 scan_end1 = _win[scan + best_len - 1];
302 scan_end = _win[scan + best_len];
303 }
304 } while ((cur_match = prev[cur_match & wmask]) > limit && --chain_length !== 0);
305
306 if (best_len <= s.lookahead) {
307 return best_len;
308 }
309 return s.lookahead;
310}
311
312
313/* ===========================================================================
314 * Fill the window when the lookahead becomes insufficient.
315 * Updates strstart and lookahead.
316 *
317 * IN assertion: lookahead < MIN_LOOKAHEAD
318 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
319 * At least one byte has been read, or avail_in == 0; reads are
320 * performed for at least two bytes (required for the zip translate_eol
321 * option -- not supported here).
322 */
323function fill_window(s) {
324 var _w_size = s.w_size;
325 var p, n, m, more, str;
326
327 //Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
328
329 do {
330 more = s.window_size - s.lookahead - s.strstart;
331
332 // JS ints have 32 bit, block below not needed
333 /* Deal with !@#$% 64K limit: */
334 //if (sizeof(int) <= 2) {
335 // if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
336 // more = wsize;
337 //
338 // } else if (more == (unsigned)(-1)) {
339 // /* Very unlikely, but possible on 16 bit machine if
340 // * strstart == 0 && lookahead == 1 (input done a byte at time)
341 // */
342 // more--;
343 // }
344 //}
345
346
347 /* If the window is almost full and there is insufficient lookahead,
348 * move the upper half to the lower one to make room in the upper half.
349 */
350 if (s.strstart >= _w_size + (_w_size - MIN_LOOKAHEAD)) {
351
352 utils.arraySet(s.window, s.window, _w_size, _w_size, 0);
353 s.match_start -= _w_size;
354 s.strstart -= _w_size;
355 /* we now have strstart >= MAX_DIST */
356 s.block_start -= _w_size;
357
358 /* Slide the hash table (could be avoided with 32 bit values
359 at the expense of memory usage). We slide even when level == 0
360 to keep the hash table consistent if we switch back to level > 0
361 later. (Using level 0 permanently is not an optimal usage of
362 zlib, so we don't care about this pathological case.)
363 */
364
365 n = s.hash_size;
366 p = n;
367 do {
368 m = s.head[--p];
369 s.head[p] = (m >= _w_size ? m - _w_size : 0);
370 } while (--n);
371
372 n = _w_size;
373 p = n;
374 do {
375 m = s.prev[--p];
376 s.prev[p] = (m >= _w_size ? m - _w_size : 0);
377 /* If n is not on any hash chain, prev[n] is garbage but
378 * its value will never be used.
379 */
380 } while (--n);
381
382 more += _w_size;
383 }
384 if (s.strm.avail_in === 0) {
385 break;
386 }
387
388 /* If there was no sliding:
389 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
390 * more == window_size - lookahead - strstart
391 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
392 * => more >= window_size - 2*WSIZE + 2
393 * In the BIG_MEM or MMAP case (not yet supported),
394 * window_size == input_size + MIN_LOOKAHEAD &&
395 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
396 * Otherwise, window_size == 2*WSIZE so more >= 2.
397 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
398 */
399 //Assert(more >= 2, "more < 2");
400 n = read_buf(s.strm, s.window, s.strstart + s.lookahead, more);
401 s.lookahead += n;
402
403 /* Initialize the hash value now that we have some input: */
404 if (s.lookahead + s.insert >= MIN_MATCH) {
405 str = s.strstart - s.insert;
406 s.ins_h = s.window[str];
407
408 /* UPDATE_HASH(s, s->ins_h, s->window[str + 1]); */
409 s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[str + 1]) & s.hash_mask;
410//#if MIN_MATCH != 3
411// Call update_hash() MIN_MATCH-3 more times
412//#endif
413 while (s.insert) {
414 /* UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); */
415 s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[str + MIN_MATCH - 1]) & s.hash_mask;
416
417 s.prev[str & s.w_mask] = s.head[s.ins_h];
418 s.head[s.ins_h] = str;
419 str++;
420 s.insert--;
421 if (s.lookahead + s.insert < MIN_MATCH) {
422 break;
423 }
424 }
425 }
426 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
427 * but this is not important since only literal bytes will be emitted.
428 */
429
430 } while (s.lookahead < MIN_LOOKAHEAD && s.strm.avail_in !== 0);
431
432 /* If the WIN_INIT bytes after the end of the current data have never been
433 * written, then zero those bytes in order to avoid memory check reports of
434 * the use of uninitialized (or uninitialised as Julian writes) bytes by
435 * the longest match routines. Update the high water mark for the next
436 * time through here. WIN_INIT is set to MAX_MATCH since the longest match
437 * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
438 */
439// if (s.high_water < s.window_size) {
440// var curr = s.strstart + s.lookahead;
441// var init = 0;
442//
443// if (s.high_water < curr) {
444// /* Previous high water mark below current data -- zero WIN_INIT
445// * bytes or up to end of window, whichever is less.
446// */
447// init = s.window_size - curr;
448// if (init > WIN_INIT)
449// init = WIN_INIT;
450// zmemzero(s->window + curr, (unsigned)init);
451// s->high_water = curr + init;
452// }
453// else if (s->high_water < (ulg)curr + WIN_INIT) {
454// /* High water mark at or above current data, but below current data
455// * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
456// * to end of window, whichever is less.
457// */
458// init = (ulg)curr + WIN_INIT - s->high_water;
459// if (init > s->window_size - s->high_water)
460// init = s->window_size - s->high_water;
461// zmemzero(s->window + s->high_water, (unsigned)init);
462// s->high_water += init;
463// }
464// }
465//
466// Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
467// "not enough room for search");
468}
469
470/* ===========================================================================
471 * Copy without compression as much as possible from the input stream, return
472 * the current block state.
473 * This function does not insert new strings in the dictionary since
474 * uncompressible data is probably not useful. This function is used
475 * only for the level=0 compression option.
476 * NOTE: this function should be optimized to avoid extra copying from
477 * window to pending_buf.
478 */
479function deflate_stored(s, flush) {
480 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
481 * to pending_buf_size, and each stored block has a 5 byte header:
482 */
483 var max_block_size = 0xffff;
484
485 if (max_block_size > s.pending_buf_size - 5) {
486 max_block_size = s.pending_buf_size - 5;
487 }
488
489 /* Copy as much as possible from input to output: */
490 for (;;) {
491 /* Fill the window as much as possible: */
492 if (s.lookahead <= 1) {
493
494 //Assert(s->strstart < s->w_size+MAX_DIST(s) ||
495 // s->block_start >= (long)s->w_size, "slide too late");
496// if (!(s.strstart < s.w_size + (s.w_size - MIN_LOOKAHEAD) ||
497// s.block_start >= s.w_size)) {
498// throw new Error("slide too late");
499// }
500
501 fill_window(s);
502 if (s.lookahead === 0 && flush === Z_NO_FLUSH) {
503 return BS_NEED_MORE;
504 }
505
506 if (s.lookahead === 0) {
507 break;
508 }
509 /* flush the current block */
510 }
511 //Assert(s->block_start >= 0L, "block gone");
512// if (s.block_start < 0) throw new Error("block gone");
513
514 s.strstart += s.lookahead;
515 s.lookahead = 0;
516
517 /* Emit a stored block if pending_buf will be full: */
518 var max_start = s.block_start + max_block_size;
519
520 if (s.strstart === 0 || s.strstart >= max_start) {
521 /* strstart == 0 is possible when wraparound on 16-bit machine */
522 s.lookahead = s.strstart - max_start;
523 s.strstart = max_start;
524 /*** FLUSH_BLOCK(s, 0); ***/
525 flush_block_only(s, false);
526 if (s.strm.avail_out === 0) {
527 return BS_NEED_MORE;
528 }
529 /***/
530
531
532 }
533 /* Flush if we may have to slide, otherwise block_start may become
534 * negative and the data will be gone:
535 */
536 if (s.strstart - s.block_start >= (s.w_size - MIN_LOOKAHEAD)) {
537 /*** FLUSH_BLOCK(s, 0); ***/
538 flush_block_only(s, false);
539 if (s.strm.avail_out === 0) {
540 return BS_NEED_MORE;
541 }
542 /***/
543 }
544 }
545
546 s.insert = 0;
547
548 if (flush === Z_FINISH) {
549 /*** FLUSH_BLOCK(s, 1); ***/
550 flush_block_only(s, true);
551 if (s.strm.avail_out === 0) {
552 return BS_FINISH_STARTED;
553 }
554 /***/
555 return BS_FINISH_DONE;
556 }
557
558 if (s.strstart > s.block_start) {
559 /*** FLUSH_BLOCK(s, 0); ***/
560 flush_block_only(s, false);
561 if (s.strm.avail_out === 0) {
562 return BS_NEED_MORE;
563 }
564 /***/
565 }
566
567 return BS_NEED_MORE;
568}
569
570/* ===========================================================================
571 * Compress as much as possible from the input stream, return the current
572 * block state.
573 * This function does not perform lazy evaluation of matches and inserts
574 * new strings in the dictionary only for unmatched strings or for short
575 * matches. It is used only for the fast compression options.
576 */
577function deflate_fast(s, flush) {
578 var hash_head; /* head of the hash chain */
579 var bflush; /* set if current block must be flushed */
580
581 for (;;) {
582 /* Make sure that we always have enough lookahead, except
583 * at the end of the input file. We need MAX_MATCH bytes
584 * for the next match, plus MIN_MATCH bytes to insert the
585 * string following the next match.
586 */
587 if (s.lookahead < MIN_LOOKAHEAD) {
588 fill_window(s);
589 if (s.lookahead < MIN_LOOKAHEAD && flush === Z_NO_FLUSH) {
590 return BS_NEED_MORE;
591 }
592 if (s.lookahead === 0) {
593 break; /* flush the current block */
594 }
595 }
596
597 /* Insert the string window[strstart .. strstart+2] in the
598 * dictionary, and set hash_head to the head of the hash chain:
599 */
600 hash_head = 0/*NIL*/;
601 if (s.lookahead >= MIN_MATCH) {
602 /*** INSERT_STRING(s, s.strstart, hash_head); ***/
603 s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + MIN_MATCH - 1]) & s.hash_mask;
604 hash_head = s.prev[s.strstart & s.w_mask] = s.head[s.ins_h];
605 s.head[s.ins_h] = s.strstart;
606 /***/
607 }
608
609 /* Find the longest match, discarding those <= prev_length.
610 * At this point we have always match_length < MIN_MATCH
611 */
612 if (hash_head !== 0/*NIL*/ && ((s.strstart - hash_head) <= (s.w_size - MIN_LOOKAHEAD))) {
613 /* To simplify the code, we prevent matches with the string
614 * of window index 0 (in particular we have to avoid a match
615 * of the string with itself at the start of the input file).
616 */
617 s.match_length = longest_match(s, hash_head);
618 /* longest_match() sets match_start */
619 }
620 if (s.match_length >= MIN_MATCH) {
621 // check_match(s, s.strstart, s.match_start, s.match_length); // for debug only
622
623 /*** _tr_tally_dist(s, s.strstart - s.match_start,
624 s.match_length - MIN_MATCH, bflush); ***/
625 bflush = trees._tr_tally(s, s.strstart - s.match_start, s.match_length - MIN_MATCH);
626
627 s.lookahead -= s.match_length;
628
629 /* Insert new strings in the hash table only if the match length
630 * is not too large. This saves time but degrades compression.
631 */
632 if (s.match_length <= s.max_lazy_match/*max_insert_length*/ && s.lookahead >= MIN_MATCH) {
633 s.match_length--; /* string at strstart already in table */
634 do {
635 s.strstart++;
636 /*** INSERT_STRING(s, s.strstart, hash_head); ***/
637 s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + MIN_MATCH - 1]) & s.hash_mask;
638 hash_head = s.prev[s.strstart & s.w_mask] = s.head[s.ins_h];
639 s.head[s.ins_h] = s.strstart;
640 /***/
641 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
642 * always MIN_MATCH bytes ahead.
643 */
644 } while (--s.match_length !== 0);
645 s.strstart++;
646 } else
647 {
648 s.strstart += s.match_length;
649 s.match_length = 0;
650 s.ins_h = s.window[s.strstart];
651 /* UPDATE_HASH(s, s.ins_h, s.window[s.strstart+1]); */
652 s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + 1]) & s.hash_mask;
653
654//#if MIN_MATCH != 3
655// Call UPDATE_HASH() MIN_MATCH-3 more times
656//#endif
657 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
658 * matter since it will be recomputed at next deflate call.
659 */
660 }
661 } else {
662 /* No match, output a literal byte */
663 //Tracevv((stderr,"%c", s.window[s.strstart]));
664 /*** _tr_tally_lit(s, s.window[s.strstart], bflush); ***/
665 bflush = trees._tr_tally(s, 0, s.window[s.strstart]);
666
667 s.lookahead--;
668 s.strstart++;
669 }
670 if (bflush) {
671 /*** FLUSH_BLOCK(s, 0); ***/
672 flush_block_only(s, false);
673 if (s.strm.avail_out === 0) {
674 return BS_NEED_MORE;
675 }
676 /***/
677 }
678 }
679 s.insert = ((s.strstart < (MIN_MATCH - 1)) ? s.strstart : MIN_MATCH - 1);
680 if (flush === Z_FINISH) {
681 /*** FLUSH_BLOCK(s, 1); ***/
682 flush_block_only(s, true);
683 if (s.strm.avail_out === 0) {
684 return BS_FINISH_STARTED;
685 }
686 /***/
687 return BS_FINISH_DONE;
688 }
689 if (s.last_lit) {
690 /*** FLUSH_BLOCK(s, 0); ***/
691 flush_block_only(s, false);
692 if (s.strm.avail_out === 0) {
693 return BS_NEED_MORE;
694 }
695 /***/
696 }
697 return BS_BLOCK_DONE;
698}
699
700/* ===========================================================================
701 * Same as above, but achieves better compression. We use a lazy
702 * evaluation for matches: a match is finally adopted only if there is
703 * no better match at the next window position.
704 */
705function deflate_slow(s, flush) {
706 var hash_head; /* head of hash chain */
707 var bflush; /* set if current block must be flushed */
708
709 var max_insert;
710
711 /* Process the input block. */
712 for (;;) {
713 /* Make sure that we always have enough lookahead, except
714 * at the end of the input file. We need MAX_MATCH bytes
715 * for the next match, plus MIN_MATCH bytes to insert the
716 * string following the next match.
717 */
718 if (s.lookahead < MIN_LOOKAHEAD) {
719 fill_window(s);
720 if (s.lookahead < MIN_LOOKAHEAD && flush === Z_NO_FLUSH) {
721 return BS_NEED_MORE;
722 }
723 if (s.lookahead === 0) { break; } /* flush the current block */
724 }
725
726 /* Insert the string window[strstart .. strstart+2] in the
727 * dictionary, and set hash_head to the head of the hash chain:
728 */
729 hash_head = 0/*NIL*/;
730 if (s.lookahead >= MIN_MATCH) {
731 /*** INSERT_STRING(s, s.strstart, hash_head); ***/
732 s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + MIN_MATCH - 1]) & s.hash_mask;
733 hash_head = s.prev[s.strstart & s.w_mask] = s.head[s.ins_h];
734 s.head[s.ins_h] = s.strstart;
735 /***/
736 }
737
738 /* Find the longest match, discarding those <= prev_length.
739 */
740 s.prev_length = s.match_length;
741 s.prev_match = s.match_start;
742 s.match_length = MIN_MATCH - 1;
743
744 if (hash_head !== 0/*NIL*/ && s.prev_length < s.max_lazy_match &&
745 s.strstart - hash_head <= (s.w_size - MIN_LOOKAHEAD)/*MAX_DIST(s)*/) {
746 /* To simplify the code, we prevent matches with the string
747 * of window index 0 (in particular we have to avoid a match
748 * of the string with itself at the start of the input file).
749 */
750 s.match_length = longest_match(s, hash_head);
751 /* longest_match() sets match_start */
752
753 if (s.match_length <= 5 &&
754 (s.strategy === Z_FILTERED || (s.match_length === MIN_MATCH && s.strstart - s.match_start > 4096/*TOO_FAR*/))) {
755
756 /* If prev_match is also MIN_MATCH, match_start is garbage
757 * but we will ignore the current match anyway.
758 */
759 s.match_length = MIN_MATCH - 1;
760 }
761 }
762 /* If there was a match at the previous step and the current
763 * match is not better, output the previous match:
764 */
765 if (s.prev_length >= MIN_MATCH && s.match_length <= s.prev_length) {
766 max_insert = s.strstart + s.lookahead - MIN_MATCH;
767 /* Do not insert strings in hash table beyond this. */
768
769 //check_match(s, s.strstart-1, s.prev_match, s.prev_length);
770
771 /***_tr_tally_dist(s, s.strstart - 1 - s.prev_match,
772 s.prev_length - MIN_MATCH, bflush);***/
773 bflush = trees._tr_tally(s, s.strstart - 1 - s.prev_match, s.prev_length - MIN_MATCH);
774 /* Insert in hash table all strings up to the end of the match.
775 * strstart-1 and strstart are already inserted. If there is not
776 * enough lookahead, the last two strings are not inserted in
777 * the hash table.
778 */
779 s.lookahead -= s.prev_length - 1;
780 s.prev_length -= 2;
781 do {
782 if (++s.strstart <= max_insert) {
783 /*** INSERT_STRING(s, s.strstart, hash_head); ***/
784 s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + MIN_MATCH - 1]) & s.hash_mask;
785 hash_head = s.prev[s.strstart & s.w_mask] = s.head[s.ins_h];
786 s.head[s.ins_h] = s.strstart;
787 /***/
788 }
789 } while (--s.prev_length !== 0);
790 s.match_available = 0;
791 s.match_length = MIN_MATCH - 1;
792 s.strstart++;
793
794 if (bflush) {
795 /*** FLUSH_BLOCK(s, 0); ***/
796 flush_block_only(s, false);
797 if (s.strm.avail_out === 0) {
798 return BS_NEED_MORE;
799 }
800 /***/
801 }
802
803 } else if (s.match_available) {
804 /* If there was no match at the previous position, output a
805 * single literal. If there was a match but the current match
806 * is longer, truncate the previous match to a single literal.
807 */
808 //Tracevv((stderr,"%c", s->window[s->strstart-1]));
809 /*** _tr_tally_lit(s, s.window[s.strstart-1], bflush); ***/
810 bflush = trees._tr_tally(s, 0, s.window[s.strstart - 1]);
811
812 if (bflush) {
813 /*** FLUSH_BLOCK_ONLY(s, 0) ***/
814 flush_block_only(s, false);
815 /***/
816 }
817 s.strstart++;
818 s.lookahead--;
819 if (s.strm.avail_out === 0) {
820 return BS_NEED_MORE;
821 }
822 } else {
823 /* There is no previous match to compare with, wait for
824 * the next step to decide.
825 */
826 s.match_available = 1;
827 s.strstart++;
828 s.lookahead--;
829 }
830 }
831 //Assert (flush != Z_NO_FLUSH, "no flush?");
832 if (s.match_available) {
833 //Tracevv((stderr,"%c", s->window[s->strstart-1]));
834 /*** _tr_tally_lit(s, s.window[s.strstart-1], bflush); ***/
835 bflush = trees._tr_tally(s, 0, s.window[s.strstart - 1]);
836
837 s.match_available = 0;
838 }
839 s.insert = s.strstart < MIN_MATCH - 1 ? s.strstart : MIN_MATCH - 1;
840 if (flush === Z_FINISH) {
841 /*** FLUSH_BLOCK(s, 1); ***/
842 flush_block_only(s, true);
843 if (s.strm.avail_out === 0) {
844 return BS_FINISH_STARTED;
845 }
846 /***/
847 return BS_FINISH_DONE;
848 }
849 if (s.last_lit) {
850 /*** FLUSH_BLOCK(s, 0); ***/
851 flush_block_only(s, false);
852 if (s.strm.avail_out === 0) {
853 return BS_NEED_MORE;
854 }
855 /***/
856 }
857
858 return BS_BLOCK_DONE;
859}
860
861
862/* ===========================================================================
863 * For Z_RLE, simply look for runs of bytes, generate matches only of distance
864 * one. Do not maintain a hash table. (It will be regenerated if this run of
865 * deflate switches away from Z_RLE.)
866 */
867function deflate_rle(s, flush) {
868 var bflush; /* set if current block must be flushed */
869 var prev; /* byte at distance one to match */
870 var scan, strend; /* scan goes up to strend for length of run */
871
872 var _win = s.window;
873
874 for (;;) {
875 /* Make sure that we always have enough lookahead, except
876 * at the end of the input file. We need MAX_MATCH bytes
877 * for the longest run, plus one for the unrolled loop.
878 */
879 if (s.lookahead <= MAX_MATCH) {
880 fill_window(s);
881 if (s.lookahead <= MAX_MATCH && flush === Z_NO_FLUSH) {
882 return BS_NEED_MORE;
883 }
884 if (s.lookahead === 0) { break; } /* flush the current block */
885 }
886
887 /* See how many times the previous byte repeats */
888 s.match_length = 0;
889 if (s.lookahead >= MIN_MATCH && s.strstart > 0) {
890 scan = s.strstart - 1;
891 prev = _win[scan];
892 if (prev === _win[++scan] && prev === _win[++scan] && prev === _win[++scan]) {
893 strend = s.strstart + MAX_MATCH;
894 do {
895 // Do nothing
896 } while (prev === _win[++scan] && prev === _win[++scan] &&
897 prev === _win[++scan] && prev === _win[++scan] &&
898 prev === _win[++scan] && prev === _win[++scan] &&
899 prev === _win[++scan] && prev === _win[++scan] &&
900 scan < strend);
901 s.match_length = MAX_MATCH - (strend - scan);
902 if (s.match_length > s.lookahead) {
903 s.match_length = s.lookahead;
904 }
905 }
906 //Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
907 }
908
909 /* Emit match if have run of MIN_MATCH or longer, else emit literal */
910 if (s.match_length >= MIN_MATCH) {
911 //check_match(s, s.strstart, s.strstart - 1, s.match_length);
912
913 /*** _tr_tally_dist(s, 1, s.match_length - MIN_MATCH, bflush); ***/
914 bflush = trees._tr_tally(s, 1, s.match_length - MIN_MATCH);
915
916 s.lookahead -= s.match_length;
917 s.strstart += s.match_length;
918 s.match_length = 0;
919 } else {
920 /* No match, output a literal byte */
921 //Tracevv((stderr,"%c", s->window[s->strstart]));
922 /*** _tr_tally_lit(s, s.window[s.strstart], bflush); ***/
923 bflush = trees._tr_tally(s, 0, s.window[s.strstart]);
924
925 s.lookahead--;
926 s.strstart++;
927 }
928 if (bflush) {
929 /*** FLUSH_BLOCK(s, 0); ***/
930 flush_block_only(s, false);
931 if (s.strm.avail_out === 0) {
932 return BS_NEED_MORE;
933 }
934 /***/
935 }
936 }
937 s.insert = 0;
938 if (flush === Z_FINISH) {
939 /*** FLUSH_BLOCK(s, 1); ***/
940 flush_block_only(s, true);
941 if (s.strm.avail_out === 0) {
942 return BS_FINISH_STARTED;
943 }
944 /***/
945 return BS_FINISH_DONE;
946 }
947 if (s.last_lit) {
948 /*** FLUSH_BLOCK(s, 0); ***/
949 flush_block_only(s, false);
950 if (s.strm.avail_out === 0) {
951 return BS_NEED_MORE;
952 }
953 /***/
954 }
955 return BS_BLOCK_DONE;
956}
957
958/* ===========================================================================
959 * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table.
960 * (It will be regenerated if this run of deflate switches away from Huffman.)
961 */
962function deflate_huff(s, flush) {
963 var bflush; /* set if current block must be flushed */
964
965 for (;;) {
966 /* Make sure that we have a literal to write. */
967 if (s.lookahead === 0) {
968 fill_window(s);
969 if (s.lookahead === 0) {
970 if (flush === Z_NO_FLUSH) {
971 return BS_NEED_MORE;
972 }
973 break; /* flush the current block */
974 }
975 }
976
977 /* Output a literal byte */
978 s.match_length = 0;
979 //Tracevv((stderr,"%c", s->window[s->strstart]));
980 /*** _tr_tally_lit(s, s.window[s.strstart], bflush); ***/
981 bflush = trees._tr_tally(s, 0, s.window[s.strstart]);
982 s.lookahead--;
983 s.strstart++;
984 if (bflush) {
985 /*** FLUSH_BLOCK(s, 0); ***/
986 flush_block_only(s, false);
987 if (s.strm.avail_out === 0) {
988 return BS_NEED_MORE;
989 }
990 /***/
991 }
992 }
993 s.insert = 0;
994 if (flush === Z_FINISH) {
995 /*** FLUSH_BLOCK(s, 1); ***/
996 flush_block_only(s, true);
997 if (s.strm.avail_out === 0) {
998 return BS_FINISH_STARTED;
999 }
1000 /***/
1001 return BS_FINISH_DONE;
1002 }
1003 if (s.last_lit) {
1004 /*** FLUSH_BLOCK(s, 0); ***/
1005 flush_block_only(s, false);
1006 if (s.strm.avail_out === 0) {
1007 return BS_NEED_MORE;
1008 }
1009 /***/
1010 }
1011 return BS_BLOCK_DONE;
1012}
1013
1014/* Values for max_lazy_match, good_match and max_chain_length, depending on
1015 * the desired pack level (0..9). The values given below have been tuned to
1016 * exclude worst case performance for pathological files. Better values may be
1017 * found for specific files.
1018 */
1019function Config(good_length, max_lazy, nice_length, max_chain, func) {
1020 this.good_length = good_length;
1021 this.max_lazy = max_lazy;
1022 this.nice_length = nice_length;
1023 this.max_chain = max_chain;
1024 this.func = func;
1025}
1026
1027var configuration_table;
1028
1029configuration_table = [
1030 /* good lazy nice chain */
1031 new Config(0, 0, 0, 0, deflate_stored), /* 0 store only */
1032 new Config(4, 4, 8, 4, deflate_fast), /* 1 max speed, no lazy matches */
1033 new Config(4, 5, 16, 8, deflate_fast), /* 2 */
1034 new Config(4, 6, 32, 32, deflate_fast), /* 3 */
1035
1036 new Config(4, 4, 16, 16, deflate_slow), /* 4 lazy matches */
1037 new Config(8, 16, 32, 32, deflate_slow), /* 5 */
1038 new Config(8, 16, 128, 128, deflate_slow), /* 6 */
1039 new Config(8, 32, 128, 256, deflate_slow), /* 7 */
1040 new Config(32, 128, 258, 1024, deflate_slow), /* 8 */
1041 new Config(32, 258, 258, 4096, deflate_slow) /* 9 max compression */
1042];
1043
1044
1045/* ===========================================================================
1046 * Initialize the "longest match" routines for a new zlib stream
1047 */
1048function lm_init(s) {
1049 s.window_size = 2 * s.w_size;
1050
1051 /*** CLEAR_HASH(s); ***/
1052 zero(s.head); // Fill with NIL (= 0);
1053
1054 /* Set the default configuration parameters:
1055 */
1056 s.max_lazy_match = configuration_table[s.level].max_lazy;
1057 s.good_match = configuration_table[s.level].good_length;
1058 s.nice_match = configuration_table[s.level].nice_length;
1059 s.max_chain_length = configuration_table[s.level].max_chain;
1060
1061 s.strstart = 0;
1062 s.block_start = 0;
1063 s.lookahead = 0;
1064 s.insert = 0;
1065 s.match_length = s.prev_length = MIN_MATCH - 1;
1066 s.match_available = 0;
1067 s.ins_h = 0;
1068}
1069
1070
1071function DeflateState() {
1072 this.strm = null; /* pointer back to this zlib stream */
1073 this.status = 0; /* as the name implies */
1074 this.pending_buf = null; /* output still pending */
1075 this.pending_buf_size = 0; /* size of pending_buf */
1076 this.pending_out = 0; /* next pending byte to output to the stream */
1077 this.pending = 0; /* nb of bytes in the pending buffer */
1078 this.wrap = 0; /* bit 0 true for zlib, bit 1 true for gzip */
1079 this.gzhead = null; /* gzip header information to write */
1080 this.gzindex = 0; /* where in extra, name, or comment */
1081 this.method = Z_DEFLATED; /* can only be DEFLATED */
1082 this.last_flush = -1; /* value of flush param for previous deflate call */
1083
1084 this.w_size = 0; /* LZ77 window size (32K by default) */
1085 this.w_bits = 0; /* log2(w_size) (8..16) */
1086 this.w_mask = 0; /* w_size - 1 */
1087
1088 this.window = null;
1089 /* Sliding window. Input bytes are read into the second half of the window,
1090 * and move to the first half later to keep a dictionary of at least wSize
1091 * bytes. With this organization, matches are limited to a distance of
1092 * wSize-MAX_MATCH bytes, but this ensures that IO is always
1093 * performed with a length multiple of the block size.
1094 */
1095
1096 this.window_size = 0;
1097 /* Actual size of window: 2*wSize, except when the user input buffer
1098 * is directly used as sliding window.
1099 */
1100
1101 this.prev = null;
1102 /* Link to older string with same hash index. To limit the size of this
1103 * array to 64K, this link is maintained only for the last 32K strings.
1104 * An index in this array is thus a window index modulo 32K.
1105 */
1106
1107 this.head = null; /* Heads of the hash chains or NIL. */
1108
1109 this.ins_h = 0; /* hash index of string to be inserted */
1110 this.hash_size = 0; /* number of elements in hash table */
1111 this.hash_bits = 0; /* log2(hash_size) */
1112 this.hash_mask = 0; /* hash_size-1 */
1113
1114 this.hash_shift = 0;
1115 /* Number of bits by which ins_h must be shifted at each input
1116 * step. It must be such that after MIN_MATCH steps, the oldest
1117 * byte no longer takes part in the hash key, that is:
1118 * hash_shift * MIN_MATCH >= hash_bits
1119 */
1120
1121 this.block_start = 0;
1122 /* Window position at the beginning of the current output block. Gets
1123 * negative when the window is moved backwards.
1124 */
1125
1126 this.match_length = 0; /* length of best match */
1127 this.prev_match = 0; /* previous match */
1128 this.match_available = 0; /* set if previous match exists */
1129 this.strstart = 0; /* start of string to insert */
1130 this.match_start = 0; /* start of matching string */
1131 this.lookahead = 0; /* number of valid bytes ahead in window */
1132
1133 this.prev_length = 0;
1134 /* Length of the best match at previous step. Matches not greater than this
1135 * are discarded. This is used in the lazy match evaluation.
1136 */
1137
1138 this.max_chain_length = 0;
1139 /* To speed up deflation, hash chains are never searched beyond this
1140 * length. A higher limit improves compression ratio but degrades the
1141 * speed.
1142 */
1143
1144 this.max_lazy_match = 0;
1145 /* Attempt to find a better match only when the current match is strictly
1146 * smaller than this value. This mechanism is used only for compression
1147 * levels >= 4.
1148 */
1149 // That's alias to max_lazy_match, don't use directly
1150 //this.max_insert_length = 0;
1151 /* Insert new strings in the hash table only if the match length is not
1152 * greater than this length. This saves time but degrades compression.
1153 * max_insert_length is used only for compression levels <= 3.
1154 */
1155
1156 this.level = 0; /* compression level (1..9) */
1157 this.strategy = 0; /* favor or force Huffman coding*/
1158
1159 this.good_match = 0;
1160 /* Use a faster search when the previous match is longer than this */
1161
1162 this.nice_match = 0; /* Stop searching when current match exceeds this */
1163
1164 /* used by trees.c: */
1165
1166 /* Didn't use ct_data typedef below to suppress compiler warning */
1167
1168 // struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
1169 // struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
1170 // struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
1171
1172 // Use flat array of DOUBLE size, with interleaved fata,
1173 // because JS does not support effective
1174 this.dyn_ltree = new utils.Buf16(HEAP_SIZE * 2);
1175 this.dyn_dtree = new utils.Buf16((2 * D_CODES + 1) * 2);
1176 this.bl_tree = new utils.Buf16((2 * BL_CODES + 1) * 2);
1177 zero(this.dyn_ltree);
1178 zero(this.dyn_dtree);
1179 zero(this.bl_tree);
1180
1181 this.l_desc = null; /* desc. for literal tree */
1182 this.d_desc = null; /* desc. for distance tree */
1183 this.bl_desc = null; /* desc. for bit length tree */
1184
1185 //ush bl_count[MAX_BITS+1];
1186 this.bl_count = new utils.Buf16(MAX_BITS + 1);
1187 /* number of codes at each bit length for an optimal tree */
1188
1189 //int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
1190 this.heap = new utils.Buf16(2 * L_CODES + 1); /* heap used to build the Huffman trees */
1191 zero(this.heap);
1192
1193 this.heap_len = 0; /* number of elements in the heap */
1194 this.heap_max = 0; /* element of largest frequency */
1195 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
1196 * The same heap array is used to build all trees.
1197 */
1198
1199 this.depth = new utils.Buf16(2 * L_CODES + 1); //uch depth[2*L_CODES+1];
1200 zero(this.depth);
1201 /* Depth of each subtree used as tie breaker for trees of equal frequency
1202 */
1203
1204 this.l_buf = 0; /* buffer index for literals or lengths */
1205
1206 this.lit_bufsize = 0;
1207 /* Size of match buffer for literals/lengths. There are 4 reasons for
1208 * limiting lit_bufsize to 64K:
1209 * - frequencies can be kept in 16 bit counters
1210 * - if compression is not successful for the first block, all input
1211 * data is still in the window so we can still emit a stored block even
1212 * when input comes from standard input. (This can also be done for
1213 * all blocks if lit_bufsize is not greater than 32K.)
1214 * - if compression is not successful for a file smaller than 64K, we can
1215 * even emit a stored file instead of a stored block (saving 5 bytes).
1216 * This is applicable only for zip (not gzip or zlib).
1217 * - creating new Huffman trees less frequently may not provide fast
1218 * adaptation to changes in the input data statistics. (Take for
1219 * example a binary file with poorly compressible code followed by
1220 * a highly compressible string table.) Smaller buffer sizes give
1221 * fast adaptation but have of course the overhead of transmitting
1222 * trees more frequently.
1223 * - I can't count above 4
1224 */
1225
1226 this.last_lit = 0; /* running index in l_buf */
1227
1228 this.d_buf = 0;
1229 /* Buffer index for distances. To simplify the code, d_buf and l_buf have
1230 * the same number of elements. To use different lengths, an extra flag
1231 * array would be necessary.
1232 */
1233
1234 this.opt_len = 0; /* bit length of current block with optimal trees */
1235 this.static_len = 0; /* bit length of current block with static trees */
1236 this.matches = 0; /* number of string matches in current block */
1237 this.insert = 0; /* bytes at end of window left to insert */
1238
1239
1240 this.bi_buf = 0;
1241 /* Output buffer. bits are inserted starting at the bottom (least
1242 * significant bits).
1243 */
1244 this.bi_valid = 0;
1245 /* Number of valid bits in bi_buf. All bits above the last valid bit
1246 * are always zero.
1247 */
1248
1249 // Used for window memory init. We safely ignore it for JS. That makes
1250 // sense only for pointers and memory check tools.
1251 //this.high_water = 0;
1252 /* High water mark offset in window for initialized bytes -- bytes above
1253 * this are set to zero in order to avoid memory check warnings when
1254 * longest match routines access bytes past the input. This is then
1255 * updated to the new high water mark.
1256 */
1257}
1258
1259
1260function deflateResetKeep(strm) {
1261 var s;
1262
1263 if (!strm || !strm.state) {
1264 return err(strm, Z_STREAM_ERROR);
1265 }
1266
1267 strm.total_in = strm.total_out = 0;
1268 strm.data_type = Z_UNKNOWN;
1269
1270 s = strm.state;
1271 s.pending = 0;
1272 s.pending_out = 0;
1273
1274 if (s.wrap < 0) {
1275 s.wrap = -s.wrap;
1276 /* was made negative by deflate(..., Z_FINISH); */
1277 }
1278 s.status = (s.wrap ? INIT_STATE : BUSY_STATE);
1279 strm.adler = (s.wrap === 2) ?
1280 0 // crc32(0, Z_NULL, 0)
1281 :
1282 1; // adler32(0, Z_NULL, 0)
1283 s.last_flush = Z_NO_FLUSH;
1284 trees._tr_init(s);
1285 return Z_OK;
1286}
1287
1288
1289function deflateReset(strm) {
1290 var ret = deflateResetKeep(strm);
1291 if (ret === Z_OK) {
1292 lm_init(strm.state);
1293 }
1294 return ret;
1295}
1296
1297
1298function deflateSetHeader(strm, head) {
1299 if (!strm || !strm.state) { return Z_STREAM_ERROR; }
1300 if (strm.state.wrap !== 2) { return Z_STREAM_ERROR; }
1301 strm.state.gzhead = head;
1302 return Z_OK;
1303}
1304
1305
1306function deflateInit2(strm, level, method, windowBits, memLevel, strategy) {
1307 if (!strm) { // === Z_NULL
1308 return Z_STREAM_ERROR;
1309 }
1310 var wrap = 1;
1311
1312 if (level === Z_DEFAULT_COMPRESSION) {
1313 level = 6;
1314 }
1315
1316 if (windowBits < 0) { /* suppress zlib wrapper */
1317 wrap = 0;
1318 windowBits = -windowBits;
1319 }
1320
1321 else if (windowBits > 15) {
1322 wrap = 2; /* write gzip wrapper instead */
1323 windowBits -= 16;
1324 }
1325
1326
1327 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method !== Z_DEFLATED ||
1328 windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
1329 strategy < 0 || strategy > Z_FIXED) {
1330 return err(strm, Z_STREAM_ERROR);
1331 }
1332
1333
1334 if (windowBits === 8) {
1335 windowBits = 9;
1336 }
1337 /* until 256-byte window bug fixed */
1338
1339 var s = new DeflateState();
1340
1341 strm.state = s;
1342 s.strm = strm;
1343
1344 s.wrap = wrap;
1345 s.gzhead = null;
1346 s.w_bits = windowBits;
1347 s.w_size = 1 << s.w_bits;
1348 s.w_mask = s.w_size - 1;
1349
1350 s.hash_bits = memLevel + 7;
1351 s.hash_size = 1 << s.hash_bits;
1352 s.hash_mask = s.hash_size - 1;
1353 s.hash_shift = ~~((s.hash_bits + MIN_MATCH - 1) / MIN_MATCH);
1354
1355 s.window = new utils.Buf8(s.w_size * 2);
1356 s.head = new utils.Buf16(s.hash_size);
1357 s.prev = new utils.Buf16(s.w_size);
1358
1359 // Don't need mem init magic for JS.
1360 //s.high_water = 0; /* nothing written to s->window yet */
1361
1362 s.lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
1363
1364 s.pending_buf_size = s.lit_bufsize * 4;
1365
1366 //overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
1367 //s->pending_buf = (uchf *) overlay;
1368 s.pending_buf = new utils.Buf8(s.pending_buf_size);
1369
1370 // It is offset from `s.pending_buf` (size is `s.lit_bufsize * 2`)
1371 //s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
1372 s.d_buf = 1 * s.lit_bufsize;
1373
1374 //s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
1375 s.l_buf = (1 + 2) * s.lit_bufsize;
1376
1377 s.level = level;
1378 s.strategy = strategy;
1379 s.method = method;
1380
1381 return deflateReset(strm);
1382}
1383
1384function deflateInit(strm, level) {
1385 return deflateInit2(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
1386}
1387
1388
1389function deflate(strm, flush) {
1390 var old_flush, s;
1391 var beg, val; // for gzip header write only
1392
1393 if (!strm || !strm.state ||
1394 flush > Z_BLOCK || flush < 0) {
1395 return strm ? err(strm, Z_STREAM_ERROR) : Z_STREAM_ERROR;
1396 }
1397
1398 s = strm.state;
1399
1400 if (!strm.output ||
1401 (!strm.input && strm.avail_in !== 0) ||
1402 (s.status === FINISH_STATE && flush !== Z_FINISH)) {
1403 return err(strm, (strm.avail_out === 0) ? Z_BUF_ERROR : Z_STREAM_ERROR);
1404 }
1405
1406 s.strm = strm; /* just in case */
1407 old_flush = s.last_flush;
1408 s.last_flush = flush;
1409
1410 /* Write the header */
1411 if (s.status === INIT_STATE) {
1412
1413 if (s.wrap === 2) { // GZIP header
1414 strm.adler = 0; //crc32(0L, Z_NULL, 0);
1415 put_byte(s, 31);
1416 put_byte(s, 139);
1417 put_byte(s, 8);
1418 if (!s.gzhead) { // s->gzhead == Z_NULL
1419 put_byte(s, 0);
1420 put_byte(s, 0);
1421 put_byte(s, 0);
1422 put_byte(s, 0);
1423 put_byte(s, 0);
1424 put_byte(s, s.level === 9 ? 2 :
1425 (s.strategy >= Z_HUFFMAN_ONLY || s.level < 2 ?
1426 4 : 0));
1427 put_byte(s, OS_CODE);
1428 s.status = BUSY_STATE;
1429 }
1430 else {
1431 put_byte(s, (s.gzhead.text ? 1 : 0) +
1432 (s.gzhead.hcrc ? 2 : 0) +
1433 (!s.gzhead.extra ? 0 : 4) +
1434 (!s.gzhead.name ? 0 : 8) +
1435 (!s.gzhead.comment ? 0 : 16)
1436 );
1437 put_byte(s, s.gzhead.time & 0xff);
1438 put_byte(s, (s.gzhead.time >> 8) & 0xff);
1439 put_byte(s, (s.gzhead.time >> 16) & 0xff);
1440 put_byte(s, (s.gzhead.time >> 24) & 0xff);
1441 put_byte(s, s.level === 9 ? 2 :
1442 (s.strategy >= Z_HUFFMAN_ONLY || s.level < 2 ?
1443 4 : 0));
1444 put_byte(s, s.gzhead.os & 0xff);
1445 if (s.gzhead.extra && s.gzhead.extra.length) {
1446 put_byte(s, s.gzhead.extra.length & 0xff);
1447 put_byte(s, (s.gzhead.extra.length >> 8) & 0xff);
1448 }
1449 if (s.gzhead.hcrc) {
1450 strm.adler = crc32(strm.adler, s.pending_buf, s.pending, 0);
1451 }
1452 s.gzindex = 0;
1453 s.status = EXTRA_STATE;
1454 }
1455 }
1456 else // DEFLATE header
1457 {
1458 var header = (Z_DEFLATED + ((s.w_bits - 8) << 4)) << 8;
1459 var level_flags = -1;
1460
1461 if (s.strategy >= Z_HUFFMAN_ONLY || s.level < 2) {
1462 level_flags = 0;
1463 } else if (s.level < 6) {
1464 level_flags = 1;
1465 } else if (s.level === 6) {
1466 level_flags = 2;
1467 } else {
1468 level_flags = 3;
1469 }
1470 header |= (level_flags << 6);
1471 if (s.strstart !== 0) { header |= PRESET_DICT; }
1472 header += 31 - (header % 31);
1473
1474 s.status = BUSY_STATE;
1475 putShortMSB(s, header);
1476
1477 /* Save the adler32 of the preset dictionary: */
1478 if (s.strstart !== 0) {
1479 putShortMSB(s, strm.adler >>> 16);
1480 putShortMSB(s, strm.adler & 0xffff);
1481 }
1482 strm.adler = 1; // adler32(0L, Z_NULL, 0);
1483 }
1484 }
1485
1486//#ifdef GZIP
1487 if (s.status === EXTRA_STATE) {
1488 if (s.gzhead.extra/* != Z_NULL*/) {
1489 beg = s.pending; /* start of bytes to update crc */
1490
1491 while (s.gzindex < (s.gzhead.extra.length & 0xffff)) {
1492 if (s.pending === s.pending_buf_size) {
1493 if (s.gzhead.hcrc && s.pending > beg) {
1494 strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg);
1495 }
1496 flush_pending(strm);
1497 beg = s.pending;
1498 if (s.pending === s.pending_buf_size) {
1499 break;
1500 }
1501 }
1502 put_byte(s, s.gzhead.extra[s.gzindex] & 0xff);
1503 s.gzindex++;
1504 }
1505 if (s.gzhead.hcrc && s.pending > beg) {
1506 strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg);
1507 }
1508 if (s.gzindex === s.gzhead.extra.length) {
1509 s.gzindex = 0;
1510 s.status = NAME_STATE;
1511 }
1512 }
1513 else {
1514 s.status = NAME_STATE;
1515 }
1516 }
1517 if (s.status === NAME_STATE) {
1518 if (s.gzhead.name/* != Z_NULL*/) {
1519 beg = s.pending; /* start of bytes to update crc */
1520 //int val;
1521
1522 do {
1523 if (s.pending === s.pending_buf_size) {
1524 if (s.gzhead.hcrc && s.pending > beg) {
1525 strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg);
1526 }
1527 flush_pending(strm);
1528 beg = s.pending;
1529 if (s.pending === s.pending_buf_size) {
1530 val = 1;
1531 break;
1532 }
1533 }
1534 // JS specific: little magic to add zero terminator to end of string
1535 if (s.gzindex < s.gzhead.name.length) {
1536 val = s.gzhead.name.charCodeAt(s.gzindex++) & 0xff;
1537 } else {
1538 val = 0;
1539 }
1540 put_byte(s, val);
1541 } while (val !== 0);
1542
1543 if (s.gzhead.hcrc && s.pending > beg) {
1544 strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg);
1545 }
1546 if (val === 0) {
1547 s.gzindex = 0;
1548 s.status = COMMENT_STATE;
1549 }
1550 }
1551 else {
1552 s.status = COMMENT_STATE;
1553 }
1554 }
1555 if (s.status === COMMENT_STATE) {
1556 if (s.gzhead.comment/* != Z_NULL*/) {
1557 beg = s.pending; /* start of bytes to update crc */
1558 //int val;
1559
1560 do {
1561 if (s.pending === s.pending_buf_size) {
1562 if (s.gzhead.hcrc && s.pending > beg) {
1563 strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg);
1564 }
1565 flush_pending(strm);
1566 beg = s.pending;
1567 if (s.pending === s.pending_buf_size) {
1568 val = 1;
1569 break;
1570 }
1571 }
1572 // JS specific: little magic to add zero terminator to end of string
1573 if (s.gzindex < s.gzhead.comment.length) {
1574 val = s.gzhead.comment.charCodeAt(s.gzindex++) & 0xff;
1575 } else {
1576 val = 0;
1577 }
1578 put_byte(s, val);
1579 } while (val !== 0);
1580
1581 if (s.gzhead.hcrc && s.pending > beg) {
1582 strm.adler = crc32(strm.adler, s.pending_buf, s.pending - beg, beg);
1583 }
1584 if (val === 0) {
1585 s.status = HCRC_STATE;
1586 }
1587 }
1588 else {
1589 s.status = HCRC_STATE;
1590 }
1591 }
1592 if (s.status === HCRC_STATE) {
1593 if (s.gzhead.hcrc) {
1594 if (s.pending + 2 > s.pending_buf_size) {
1595 flush_pending(strm);
1596 }
1597 if (s.pending + 2 <= s.pending_buf_size) {
1598 put_byte(s, strm.adler & 0xff);
1599 put_byte(s, (strm.adler >> 8) & 0xff);
1600 strm.adler = 0; //crc32(0L, Z_NULL, 0);
1601 s.status = BUSY_STATE;
1602 }
1603 }
1604 else {
1605 s.status = BUSY_STATE;
1606 }
1607 }
1608//#endif
1609
1610 /* Flush as much pending output as possible */
1611 if (s.pending !== 0) {
1612 flush_pending(strm);
1613 if (strm.avail_out === 0) {
1614 /* Since avail_out is 0, deflate will be called again with
1615 * more output space, but possibly with both pending and
1616 * avail_in equal to zero. There won't be anything to do,
1617 * but this is not an error situation so make sure we
1618 * return OK instead of BUF_ERROR at next call of deflate:
1619 */
1620 s.last_flush = -1;
1621 return Z_OK;
1622 }
1623
1624 /* Make sure there is something to do and avoid duplicate consecutive
1625 * flushes. For repeated and useless calls with Z_FINISH, we keep
1626 * returning Z_STREAM_END instead of Z_BUF_ERROR.
1627 */
1628 } else if (strm.avail_in === 0 && rank(flush) <= rank(old_flush) &&
1629 flush !== Z_FINISH) {
1630 return err(strm, Z_BUF_ERROR);
1631 }
1632
1633 /* User must not provide more input after the first FINISH: */
1634 if (s.status === FINISH_STATE && strm.avail_in !== 0) {
1635 return err(strm, Z_BUF_ERROR);
1636 }
1637
1638 /* Start a new block or continue the current one.
1639 */
1640 if (strm.avail_in !== 0 || s.lookahead !== 0 ||
1641 (flush !== Z_NO_FLUSH && s.status !== FINISH_STATE)) {
1642 var bstate = (s.strategy === Z_HUFFMAN_ONLY) ? deflate_huff(s, flush) :
1643 (s.strategy === Z_RLE ? deflate_rle(s, flush) :
1644 configuration_table[s.level].func(s, flush));
1645
1646 if (bstate === BS_FINISH_STARTED || bstate === BS_FINISH_DONE) {
1647 s.status = FINISH_STATE;
1648 }
1649 if (bstate === BS_NEED_MORE || bstate === BS_FINISH_STARTED) {
1650 if (strm.avail_out === 0) {
1651 s.last_flush = -1;
1652 /* avoid BUF_ERROR next call, see above */
1653 }
1654 return Z_OK;
1655 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1656 * of deflate should use the same flush parameter to make sure
1657 * that the flush is complete. So we don't have to output an
1658 * empty block here, this will be done at next call. This also
1659 * ensures that for a very small output buffer, we emit at most
1660 * one empty block.
1661 */
1662 }
1663 if (bstate === BS_BLOCK_DONE) {
1664 if (flush === Z_PARTIAL_FLUSH) {
1665 trees._tr_align(s);
1666 }
1667 else if (flush !== Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
1668
1669 trees._tr_stored_block(s, 0, 0, false);
1670 /* For a full flush, this empty block will be recognized
1671 * as a special marker by inflate_sync().
1672 */
1673 if (flush === Z_FULL_FLUSH) {
1674 /*** CLEAR_HASH(s); ***/ /* forget history */
1675 zero(s.head); // Fill with NIL (= 0);
1676
1677 if (s.lookahead === 0) {
1678 s.strstart = 0;
1679 s.block_start = 0;
1680 s.insert = 0;
1681 }
1682 }
1683 }
1684 flush_pending(strm);
1685 if (strm.avail_out === 0) {
1686 s.last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1687 return Z_OK;
1688 }
1689 }
1690 }
1691 //Assert(strm->avail_out > 0, "bug2");
1692 //if (strm.avail_out <= 0) { throw new Error("bug2");}
1693
1694 if (flush !== Z_FINISH) { return Z_OK; }
1695 if (s.wrap <= 0) { return Z_STREAM_END; }
1696
1697 /* Write the trailer */
1698 if (s.wrap === 2) {
1699 put_byte(s, strm.adler & 0xff);
1700 put_byte(s, (strm.adler >> 8) & 0xff);
1701 put_byte(s, (strm.adler >> 16) & 0xff);
1702 put_byte(s, (strm.adler >> 24) & 0xff);
1703 put_byte(s, strm.total_in & 0xff);
1704 put_byte(s, (strm.total_in >> 8) & 0xff);
1705 put_byte(s, (strm.total_in >> 16) & 0xff);
1706 put_byte(s, (strm.total_in >> 24) & 0xff);
1707 }
1708 else
1709 {
1710 putShortMSB(s, strm.adler >>> 16);
1711 putShortMSB(s, strm.adler & 0xffff);
1712 }
1713
1714 flush_pending(strm);
1715 /* If avail_out is zero, the application will call deflate again
1716 * to flush the rest.
1717 */
1718 if (s.wrap > 0) { s.wrap = -s.wrap; }
1719 /* write the trailer only once! */
1720 return s.pending !== 0 ? Z_OK : Z_STREAM_END;
1721}
1722
1723function deflateEnd(strm) {
1724 var status;
1725
1726 if (!strm/*== Z_NULL*/ || !strm.state/*== Z_NULL*/) {
1727 return Z_STREAM_ERROR;
1728 }
1729
1730 status = strm.state.status;
1731 if (status !== INIT_STATE &&
1732 status !== EXTRA_STATE &&
1733 status !== NAME_STATE &&
1734 status !== COMMENT_STATE &&
1735 status !== HCRC_STATE &&
1736 status !== BUSY_STATE &&
1737 status !== FINISH_STATE
1738 ) {
1739 return err(strm, Z_STREAM_ERROR);
1740 }
1741
1742 strm.state = null;
1743
1744 return status === BUSY_STATE ? err(strm, Z_DATA_ERROR) : Z_OK;
1745}
1746
1747
1748/* =========================================================================
1749 * Initializes the compression dictionary from the given byte
1750 * sequence without producing any compressed output.
1751 */
1752function deflateSetDictionary(strm, dictionary) {
1753 var dictLength = dictionary.length;
1754
1755 var s;
1756 var str, n;
1757 var wrap;
1758 var avail;
1759 var next;
1760 var input;
1761 var tmpDict;
1762
1763 if (!strm/*== Z_NULL*/ || !strm.state/*== Z_NULL*/) {
1764 return Z_STREAM_ERROR;
1765 }
1766
1767 s = strm.state;
1768 wrap = s.wrap;
1769
1770 if (wrap === 2 || (wrap === 1 && s.status !== INIT_STATE) || s.lookahead) {
1771 return Z_STREAM_ERROR;
1772 }
1773
1774 /* when using zlib wrappers, compute Adler-32 for provided dictionary */
1775 if (wrap === 1) {
1776 /* adler32(strm->adler, dictionary, dictLength); */
1777 strm.adler = adler32(strm.adler, dictionary, dictLength, 0);
1778 }
1779
1780 s.wrap = 0; /* avoid computing Adler-32 in read_buf */
1781
1782 /* if dictionary would fill window, just replace the history */
1783 if (dictLength >= s.w_size) {
1784 if (wrap === 0) { /* already empty otherwise */
1785 /*** CLEAR_HASH(s); ***/
1786 zero(s.head); // Fill with NIL (= 0);
1787 s.strstart = 0;
1788 s.block_start = 0;
1789 s.insert = 0;
1790 }
1791 /* use the tail */
1792 // dictionary = dictionary.slice(dictLength - s.w_size);
1793 tmpDict = new utils.Buf8(s.w_size);
1794 utils.arraySet(tmpDict, dictionary, dictLength - s.w_size, s.w_size, 0);
1795 dictionary = tmpDict;
1796 dictLength = s.w_size;
1797 }
1798 /* insert dictionary into window and hash */
1799 avail = strm.avail_in;
1800 next = strm.next_in;
1801 input = strm.input;
1802 strm.avail_in = dictLength;
1803 strm.next_in = 0;
1804 strm.input = dictionary;
1805 fill_window(s);
1806 while (s.lookahead >= MIN_MATCH) {
1807 str = s.strstart;
1808 n = s.lookahead - (MIN_MATCH - 1);
1809 do {
1810 /* UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); */
1811 s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[str + MIN_MATCH - 1]) & s.hash_mask;
1812
1813 s.prev[str & s.w_mask] = s.head[s.ins_h];
1814
1815 s.head[s.ins_h] = str;
1816 str++;
1817 } while (--n);
1818 s.strstart = str;
1819 s.lookahead = MIN_MATCH - 1;
1820 fill_window(s);
1821 }
1822 s.strstart += s.lookahead;
1823 s.block_start = s.strstart;
1824 s.insert = s.lookahead;
1825 s.lookahead = 0;
1826 s.match_length = s.prev_length = MIN_MATCH - 1;
1827 s.match_available = 0;
1828 strm.next_in = next;
1829 strm.input = input;
1830 strm.avail_in = avail;
1831 s.wrap = wrap;
1832 return Z_OK;
1833}
1834
1835
1836export { deflateInit, deflateInit2, deflateReset, deflateResetKeep, deflateSetHeader, deflate, deflateEnd, deflateSetDictionary };
1837export var deflateInfo = 'pako deflate (from Nodeca project)';
1838
1839/* Not implemented
1840exports.deflateBound = deflateBound;
1841exports.deflateCopy = deflateCopy;
1842exports.deflateParams = deflateParams;
1843exports.deflatePending = deflatePending;
1844exports.deflatePrime = deflatePrime;
1845exports.deflateTune = deflateTune;
1846*/