Annotation of embedaddon/rsync/zlib/inflate.c, revision 1.1.1.1
1.1 misho 1: /* inflate.c -- zlib decompression
2: * Copyright (C) 1995-2005 Mark Adler
3: * For conditions of distribution and use, see copyright notice in zlib.h
4: */
5:
6: /*
7: * Change history:
8: *
9: * 1.2.beta0 24 Nov 2002
10: * - First version -- complete rewrite of inflate to simplify code, avoid
11: * creation of window when not needed, minimize use of window when it is
12: * needed, make inffast.c even faster, implement gzip decoding, and to
13: * improve code readability and style over the previous zlib inflate code
14: *
15: * 1.2.beta1 25 Nov 2002
16: * - Use pointers for available input and output checking in inffast.c
17: * - Remove input and output counters in inffast.c
18: * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
19: * - Remove unnecessary second byte pull from length extra in inffast.c
20: * - Unroll direct copy to three copies per loop in inffast.c
21: *
22: * 1.2.beta2 4 Dec 2002
23: * - Change external routine names to reduce potential conflicts
24: * - Correct filename to inffixed.h for fixed tables in inflate.c
25: * - Make hbuf[] unsigned char to match parameter type in inflate.c
26: * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
27: * to avoid negation problem on Alphas (64 bit) in inflate.c
28: *
29: * 1.2.beta3 22 Dec 2002
30: * - Add comments on state->bits assertion in inffast.c
31: * - Add comments on op field in inftrees.h
32: * - Fix bug in reuse of allocated window after inflateReset()
33: * - Remove bit fields--back to byte structure for speed
34: * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
35: * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
36: * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
37: * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
38: * - Use local copies of stream next and avail values, as well as local bit
39: * buffer and bit count in inflate()--for speed when inflate_fast() not used
40: *
41: * 1.2.beta4 1 Jan 2003
42: * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
43: * - Move a comment on output buffer sizes from inffast.c to inflate.c
44: * - Add comments in inffast.c to introduce the inflate_fast() routine
45: * - Rearrange window copies in inflate_fast() for speed and simplification
46: * - Unroll last copy for window match in inflate_fast()
47: * - Use local copies of window variables in inflate_fast() for speed
48: * - Pull out common write == 0 case for speed in inflate_fast()
49: * - Make op and len in inflate_fast() unsigned for consistency
50: * - Add FAR to lcode and dcode declarations in inflate_fast()
51: * - Simplified bad distance check in inflate_fast()
52: * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
53: * source file infback.c to provide a call-back interface to inflate for
54: * programs like gzip and unzip -- uses window as output buffer to avoid
55: * window copying
56: *
57: * 1.2.beta5 1 Jan 2003
58: * - Improved inflateBack() interface to allow the caller to provide initial
59: * input in strm.
60: * - Fixed stored blocks bug in inflateBack()
61: *
62: * 1.2.beta6 4 Jan 2003
63: * - Added comments in inffast.c on effectiveness of POSTINC
64: * - Typecasting all around to reduce compiler warnings
65: * - Changed loops from while (1) or do {} while (1) to for (;;), again to
66: * make compilers happy
67: * - Changed type of window in inflateBackInit() to unsigned char *
68: *
69: * 1.2.beta7 27 Jan 2003
70: * - Changed many types to unsigned or unsigned short to avoid warnings
71: * - Added inflateCopy() function
72: *
73: * 1.2.0 9 Mar 2003
74: * - Changed inflateBack() interface to provide separate opaque descriptors
75: * for the in() and out() functions
76: * - Changed inflateBack() argument and in_func typedef to swap the length
77: * and buffer address return values for the input function
78: * - Check next_in and next_out for Z_NULL on entry to inflate()
79: *
80: * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
81: */
82:
83: #include "zutil.h"
84: #include "inftrees.h"
85: #include "inflate.h"
86: #include "inffast.h"
87:
88: #ifdef MAKEFIXED
89: # ifndef BUILDFIXED
90: # define BUILDFIXED
91: # endif
92: #endif
93:
94: /* function prototypes */
95: local void fixedtables OF((struct inflate_state FAR *state));
96: local int updatewindow OF((z_streamp strm, unsigned out));
97: #ifdef BUILDFIXED
98: void makefixed OF((void));
99: #endif
100: local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
101: unsigned len));
102:
103: int ZEXPORT inflateReset(strm)
104: z_streamp strm;
105: {
106: struct inflate_state FAR *state;
107:
108: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
109: state = (struct inflate_state FAR *)strm->state;
110: strm->total_in = strm->total_out = state->total = 0;
111: strm->msg = Z_NULL;
112: strm->adler = 1; /* to support ill-conceived Java test suite */
113: state->mode = HEAD;
114: state->last = 0;
115: state->havedict = 0;
116: state->dmax = 32768U;
117: state->head = Z_NULL;
118: state->wsize = 0;
119: state->whave = 0;
120: state->write = 0;
121: state->hold = 0;
122: state->bits = 0;
123: state->lencode = state->distcode = state->next = state->codes;
124: Tracev((stderr, "inflate: reset\n"));
125: return Z_OK;
126: }
127:
128: int ZEXPORT inflatePrime(strm, bits, value)
129: z_streamp strm;
130: int bits;
131: int value;
132: {
133: struct inflate_state FAR *state;
134:
135: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
136: state = (struct inflate_state FAR *)strm->state;
137: if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
138: value &= (1L << bits) - 1;
139: state->hold += value << state->bits;
140: state->bits += bits;
141: return Z_OK;
142: }
143:
144: int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
145: z_streamp strm;
146: int windowBits;
147: const char *version;
148: int stream_size;
149: {
150: struct inflate_state FAR *state;
151:
152: if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
153: stream_size != (int)(sizeof(z_stream)))
154: return Z_VERSION_ERROR;
155: if (strm == Z_NULL) return Z_STREAM_ERROR;
156: strm->msg = Z_NULL; /* in case we return an error */
157: if (strm->zalloc == (alloc_func)0) {
158: strm->zalloc = zcalloc;
159: strm->opaque = (voidpf)0;
160: }
161: if (strm->zfree == (free_func)0) strm->zfree = zcfree;
162: state = (struct inflate_state FAR *)
163: ZALLOC(strm, 1, sizeof(struct inflate_state));
164: if (state == Z_NULL) return Z_MEM_ERROR;
165: Tracev((stderr, "inflate: allocated\n"));
166: strm->state = (struct internal_state FAR *)state;
167: if (windowBits < 0) {
168: state->wrap = 0;
169: windowBits = -windowBits;
170: }
171: else {
172: state->wrap = (windowBits >> 4) + 1;
173: #ifdef GUNZIP
174: if (windowBits < 48) windowBits &= 15;
175: #endif
176: }
177: if (windowBits < 8 || windowBits > 15) {
178: ZFREE(strm, state);
179: strm->state = Z_NULL;
180: return Z_STREAM_ERROR;
181: }
182: state->wbits = (unsigned)windowBits;
183: state->window = Z_NULL;
184: return inflateReset(strm);
185: }
186:
187: int ZEXPORT inflateInit_(strm, version, stream_size)
188: z_streamp strm;
189: const char *version;
190: int stream_size;
191: {
192: return inflateInit2_(strm, DEF_WBITS, version, stream_size);
193: }
194:
195: /*
196: Return state with length and distance decoding tables and index sizes set to
197: fixed code decoding. Normally this returns fixed tables from inffixed.h.
198: If BUILDFIXED is defined, then instead this routine builds the tables the
199: first time it's called, and returns those tables the first time and
200: thereafter. This reduces the size of the code by about 2K bytes, in
201: exchange for a little execution time. However, BUILDFIXED should not be
202: used for threaded applications, since the rewriting of the tables and virgin
203: may not be thread-safe.
204: */
205: local void fixedtables(state)
206: struct inflate_state FAR *state;
207: {
208: #ifdef BUILDFIXED
209: static int virgin = 1;
210: static code *lenfix, *distfix;
211: static code fixed[544];
212:
213: /* build fixed huffman tables if first call (may not be thread safe) */
214: if (virgin) {
215: unsigned sym, bits;
216: static code *next;
217:
218: /* literal/length table */
219: sym = 0;
220: while (sym < 144) state->lens[sym++] = 8;
221: while (sym < 256) state->lens[sym++] = 9;
222: while (sym < 280) state->lens[sym++] = 7;
223: while (sym < 288) state->lens[sym++] = 8;
224: next = fixed;
225: lenfix = next;
226: bits = 9;
227: inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
228:
229: /* distance table */
230: sym = 0;
231: while (sym < 32) state->lens[sym++] = 5;
232: distfix = next;
233: bits = 5;
234: inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
235:
236: /* do this just once */
237: virgin = 0;
238: }
239: #else /* !BUILDFIXED */
240: # include "inffixed.h"
241: #endif /* BUILDFIXED */
242: state->lencode = lenfix;
243: state->lenbits = 9;
244: state->distcode = distfix;
245: state->distbits = 5;
246: }
247:
248: #ifdef MAKEFIXED
249: #include <stdio.h>
250:
251: /*
252: Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
253: defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
254: those tables to stdout, which would be piped to inffixed.h. A small program
255: can simply call makefixed to do this:
256:
257: void makefixed(void);
258:
259: int main(void)
260: {
261: makefixed();
262: return 0;
263: }
264:
265: Then that can be linked with zlib built with MAKEFIXED defined and run:
266:
267: a.out > inffixed.h
268: */
269: void makefixed()
270: {
271: unsigned low, size;
272: struct inflate_state state;
273:
274: fixedtables(&state);
275: puts(" /* inffixed.h -- table for decoding fixed codes");
276: puts(" * Generated automatically by makefixed().");
277: puts(" */");
278: puts("");
279: puts(" /* WARNING: this file should *not* be used by applications.");
280: puts(" It is part of the implementation of this library and is");
281: puts(" subject to change. Applications should only use zlib.h.");
282: puts(" */");
283: puts("");
284: size = 1U << 9;
285: printf(" static const code lenfix[%u] = {", size);
286: low = 0;
287: for (;;) {
288: if ((low % 7) == 0) printf("\n ");
289: printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits,
290: state.lencode[low].val);
291: if (++low == size) break;
292: putchar(',');
293: }
294: puts("\n };");
295: size = 1U << 5;
296: printf("\n static const code distfix[%u] = {", size);
297: low = 0;
298: for (;;) {
299: if ((low % 6) == 0) printf("\n ");
300: printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
301: state.distcode[low].val);
302: if (++low == size) break;
303: putchar(',');
304: }
305: puts("\n };");
306: }
307: #endif /* MAKEFIXED */
308:
309: /*
310: Update the window with the last wsize (normally 32K) bytes written before
311: returning. If window does not exist yet, create it. This is only called
312: when a window is already in use, or when output has been written during this
313: inflate call, but the end of the deflate stream has not been reached yet.
314: It is also called to create a window for dictionary data when a dictionary
315: is loaded.
316:
317: Providing output buffers larger than 32K to inflate() should provide a speed
318: advantage, since only the last 32K of output is copied to the sliding window
319: upon return from inflate(), and since all distances after the first 32K of
320: output will fall in the output data, making match copies simpler and faster.
321: The advantage may be dependent on the size of the processor's data caches.
322: */
323: local int updatewindow(strm, out)
324: z_streamp strm;
325: unsigned out;
326: {
327: struct inflate_state FAR *state;
328: unsigned copy, dist;
329:
330: state = (struct inflate_state FAR *)strm->state;
331:
332: /* if it hasn't been done already, allocate space for the window */
333: if (state->window == Z_NULL) {
334: state->window = (unsigned char FAR *)
335: ZALLOC(strm, 1U << state->wbits,
336: sizeof(unsigned char));
337: if (state->window == Z_NULL) return 1;
338: }
339:
340: /* if window not in use yet, initialize */
341: if (state->wsize == 0) {
342: state->wsize = 1U << state->wbits;
343: state->write = 0;
344: state->whave = 0;
345: }
346:
347: /* copy state->wsize or less output bytes into the circular window */
348: copy = out - strm->avail_out;
349: if (copy >= state->wsize) {
350: zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
351: state->write = 0;
352: state->whave = state->wsize;
353: }
354: else {
355: dist = state->wsize - state->write;
356: if (dist > copy) dist = copy;
357: zmemcpy(state->window + state->write, strm->next_out - copy, dist);
358: copy -= dist;
359: if (copy) {
360: zmemcpy(state->window, strm->next_out - copy, copy);
361: state->write = copy;
362: state->whave = state->wsize;
363: }
364: else {
365: state->write += dist;
366: if (state->write == state->wsize) state->write = 0;
367: if (state->whave < state->wsize) state->whave += dist;
368: }
369: }
370: return 0;
371: }
372:
373: /* Macros for inflate(): */
374:
375: /* check function to use adler32() for zlib or crc32() for gzip */
376: #ifdef GUNZIP
377: # define UPDATE(check, buf, len) \
378: (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
379: #else
380: # define UPDATE(check, buf, len) adler32(check, buf, len)
381: #endif
382:
383: /* check macros for header crc */
384: #ifdef GUNZIP
385: # define CRC2(check, word) \
386: do { \
387: hbuf[0] = (unsigned char)(word); \
388: hbuf[1] = (unsigned char)((word) >> 8); \
389: check = crc32(check, hbuf, 2); \
390: } while (0)
391:
392: # define CRC4(check, word) \
393: do { \
394: hbuf[0] = (unsigned char)(word); \
395: hbuf[1] = (unsigned char)((word) >> 8); \
396: hbuf[2] = (unsigned char)((word) >> 16); \
397: hbuf[3] = (unsigned char)((word) >> 24); \
398: check = crc32(check, hbuf, 4); \
399: } while (0)
400: #endif
401:
402: /* Load registers with state in inflate() for speed */
403: #define LOAD() \
404: do { \
405: put = strm->next_out; \
406: left = strm->avail_out; \
407: next = strm->next_in; \
408: have = strm->avail_in; \
409: hold = state->hold; \
410: bits = state->bits; \
411: } while (0)
412:
413: /* Restore state from registers in inflate() */
414: #define RESTORE() \
415: do { \
416: strm->next_out = put; \
417: strm->avail_out = left; \
418: strm->next_in = next; \
419: strm->avail_in = have; \
420: state->hold = hold; \
421: state->bits = bits; \
422: } while (0)
423:
424: /* Clear the input bit accumulator */
425: #define INITBITS() \
426: do { \
427: hold = 0; \
428: bits = 0; \
429: } while (0)
430:
431: /* Get a byte of input into the bit accumulator, or return from inflate()
432: if there is no input available. */
433: #define PULLBYTE() \
434: do { \
435: if (have == 0) goto inf_leave; \
436: have--; \
437: hold += (unsigned long)(*next++) << bits; \
438: bits += 8; \
439: } while (0)
440:
441: /* Assure that there are at least n bits in the bit accumulator. If there is
442: not enough available input to do that, then return from inflate(). */
443: #define NEEDBITS(n) \
444: do { \
445: while (bits < (unsigned)(n)) \
446: PULLBYTE(); \
447: } while (0)
448:
449: /* Return the low n bits of the bit accumulator (n < 16) */
450: #define BITS(n) \
451: ((unsigned)hold & ((1U << (n)) - 1))
452:
453: /* Remove n bits from the bit accumulator */
454: #define DROPBITS(n) \
455: do { \
456: hold >>= (n); \
457: bits -= (unsigned)(n); \
458: } while (0)
459:
460: /* Remove zero to seven bits as needed to go to a byte boundary */
461: #define BYTEBITS() \
462: do { \
463: hold >>= bits & 7; \
464: bits -= bits & 7; \
465: } while (0)
466:
467: /* Reverse the bytes in a 32-bit value */
468: #define REVERSE(q) \
469: ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
470: (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
471:
472: /*
473: inflate() uses a state machine to process as much input data and generate as
474: much output data as possible before returning. The state machine is
475: structured roughly as follows:
476:
477: for (;;) switch (state) {
478: ...
479: case STATEn:
480: if (not enough input data or output space to make progress)
481: return;
482: ... make progress ...
483: state = STATEm;
484: break;
485: ...
486: }
487:
488: so when inflate() is called again, the same case is attempted again, and
489: if the appropriate resources are provided, the machine proceeds to the
490: next state. The NEEDBITS() macro is usually the way the state evaluates
491: whether it can proceed or should return. NEEDBITS() does the return if
492: the requested bits are not available. The typical use of the BITS macros
493: is:
494:
495: NEEDBITS(n);
496: ... do something with BITS(n) ...
497: DROPBITS(n);
498:
499: where NEEDBITS(n) either returns from inflate() if there isn't enough
500: input left to load n bits into the accumulator, or it continues. BITS(n)
501: gives the low n bits in the accumulator. When done, DROPBITS(n) drops
502: the low n bits off the accumulator. INITBITS() clears the accumulator
503: and sets the number of available bits to zero. BYTEBITS() discards just
504: enough bits to put the accumulator on a byte boundary. After BYTEBITS()
505: and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
506:
507: NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
508: if there is no input available. The decoding of variable length codes uses
509: PULLBYTE() directly in order to pull just enough bytes to decode the next
510: code, and no more.
511:
512: Some states loop until they get enough input, making sure that enough
513: state information is maintained to continue the loop where it left off
514: if NEEDBITS() returns in the loop. For example, want, need, and keep
515: would all have to actually be part of the saved state in case NEEDBITS()
516: returns:
517:
518: case STATEw:
519: while (want < need) {
520: NEEDBITS(n);
521: keep[want++] = BITS(n);
522: DROPBITS(n);
523: }
524: state = STATEx;
525: case STATEx:
526:
527: As shown above, if the next state is also the next case, then the break
528: is omitted.
529:
530: A state may also return if there is not enough output space available to
531: complete that state. Those states are copying stored data, writing a
532: literal byte, and copying a matching string.
533:
534: When returning, a "goto inf_leave" is used to update the total counters,
535: update the check value, and determine whether any progress has been made
536: during that inflate() call in order to return the proper return code.
537: Progress is defined as a change in either strm->avail_in or strm->avail_out.
538: When there is a window, goto inf_leave will update the window with the last
539: output written. If a goto inf_leave occurs in the middle of decompression
540: and there is no window currently, goto inf_leave will create one and copy
541: output to the window for the next call of inflate().
542:
543: In this implementation, the flush parameter of inflate() only affects the
544: return code (per zlib.h). inflate() always writes as much as possible to
545: strm->next_out, given the space available and the provided input--the effect
546: documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
547: the allocation of and copying into a sliding window until necessary, which
548: provides the effect documented in zlib.h for Z_FINISH when the entire input
549: stream available. So the only thing the flush parameter actually does is:
550: when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
551: will return Z_BUF_ERROR if it has not reached the end of the stream.
552: */
553:
554: int ZEXPORT inflate(strm, flush)
555: z_streamp strm;
556: int flush;
557: {
558: struct inflate_state FAR *state;
559: unsigned char FAR *next; /* next input */
560: unsigned char FAR *put; /* next output */
561: unsigned have, left; /* available input and output */
562: unsigned long hold; /* bit buffer */
563: unsigned bits; /* bits in bit buffer */
564: unsigned in, out; /* save starting available input and output */
565: unsigned copy; /* number of stored or match bytes to copy */
566: unsigned char FAR *from; /* where to copy match bytes from */
567: code this; /* current decoding table entry */
568: code last; /* parent table entry */
569: unsigned len; /* length to copy for repeats, bits to drop */
570: int ret; /* return code */
571: #ifdef GUNZIP
572: unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
573: #endif
574: static const unsigned short order[19] = /* permutation of code lengths */
575: {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
576:
577: if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
578: (strm->next_in == Z_NULL && strm->avail_in != 0))
579: return Z_STREAM_ERROR;
580:
581: state = (struct inflate_state FAR *)strm->state;
582: if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
583: LOAD();
584: in = have;
585: out = left;
586: ret = Z_OK;
587: for (;;)
588: switch (state->mode) {
589: case HEAD:
590: if (state->wrap == 0) {
591: state->mode = TYPEDO;
592: break;
593: }
594: NEEDBITS(16);
595: #ifdef GUNZIP
596: if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
597: state->check = crc32(0L, Z_NULL, 0);
598: CRC2(state->check, hold);
599: INITBITS();
600: state->mode = FLAGS;
601: break;
602: }
603: state->flags = 0; /* expect zlib header */
604: if (state->head != Z_NULL)
605: state->head->done = -1;
606: if (!(state->wrap & 1) || /* check if zlib header allowed */
607: #else
608: if (
609: #endif
610: ((BITS(8) << 8) + (hold >> 8)) % 31) {
611: strm->msg = (char *)"incorrect header check";
612: state->mode = BAD;
613: break;
614: }
615: if (BITS(4) != Z_DEFLATED) {
616: strm->msg = (char *)"unknown compression method";
617: state->mode = BAD;
618: break;
619: }
620: DROPBITS(4);
621: len = BITS(4) + 8;
622: if (len > state->wbits) {
623: strm->msg = (char *)"invalid window size";
624: state->mode = BAD;
625: break;
626: }
627: state->dmax = 1U << len;
628: Tracev((stderr, "inflate: zlib header ok\n"));
629: strm->adler = state->check = adler32(0L, Z_NULL, 0);
630: state->mode = hold & 0x200 ? DICTID : TYPE;
631: INITBITS();
632: break;
633: #ifdef GUNZIP
634: case FLAGS:
635: NEEDBITS(16);
636: state->flags = (int)(hold);
637: if ((state->flags & 0xff) != Z_DEFLATED) {
638: strm->msg = (char *)"unknown compression method";
639: state->mode = BAD;
640: break;
641: }
642: if (state->flags & 0xe000) {
643: strm->msg = (char *)"unknown header flags set";
644: state->mode = BAD;
645: break;
646: }
647: if (state->head != Z_NULL)
648: state->head->text = (int)((hold >> 8) & 1);
649: if (state->flags & 0x0200) CRC2(state->check, hold);
650: INITBITS();
651: state->mode = TIME;
652: /* FALL THROUGH */
653: case TIME:
654: NEEDBITS(32);
655: if (state->head != Z_NULL)
656: state->head->time = hold;
657: if (state->flags & 0x0200) CRC4(state->check, hold);
658: INITBITS();
659: state->mode = OS;
660: /* FALL THROUGH */
661: case OS:
662: NEEDBITS(16);
663: if (state->head != Z_NULL) {
664: state->head->xflags = (int)(hold & 0xff);
665: state->head->os = (int)(hold >> 8);
666: }
667: if (state->flags & 0x0200) CRC2(state->check, hold);
668: INITBITS();
669: state->mode = EXLEN;
670: /* FALL THROUGH */
671: case EXLEN:
672: if (state->flags & 0x0400) {
673: NEEDBITS(16);
674: state->length = (unsigned)(hold);
675: if (state->head != Z_NULL)
676: state->head->extra_len = (unsigned)hold;
677: if (state->flags & 0x0200) CRC2(state->check, hold);
678: INITBITS();
679: }
680: else if (state->head != Z_NULL)
681: state->head->extra = Z_NULL;
682: state->mode = EXTRA;
683: /* FALL THROUGH */
684: case EXTRA:
685: if (state->flags & 0x0400) {
686: copy = state->length;
687: if (copy > have) copy = have;
688: if (copy) {
689: if (state->head != Z_NULL &&
690: state->head->extra != Z_NULL) {
691: len = state->head->extra_len - state->length;
692: zmemcpy(state->head->extra + len, next,
693: len + copy > state->head->extra_max ?
694: state->head->extra_max - len : copy);
695: }
696: if (state->flags & 0x0200)
697: state->check = crc32(state->check, next, copy);
698: have -= copy;
699: next += copy;
700: state->length -= copy;
701: }
702: if (state->length) goto inf_leave;
703: }
704: state->length = 0;
705: state->mode = NAME;
706: /* FALL THROUGH */
707: case NAME:
708: if (state->flags & 0x0800) {
709: if (have == 0) goto inf_leave;
710: copy = 0;
711: do {
712: len = (unsigned)(next[copy++]);
713: if (state->head != Z_NULL &&
714: state->head->name != Z_NULL &&
715: state->length < state->head->name_max)
716: state->head->name[state->length++] = len;
717: } while (len && copy < have);
718: if (state->flags & 0x0200)
719: state->check = crc32(state->check, next, copy);
720: have -= copy;
721: next += copy;
722: if (len) goto inf_leave;
723: }
724: else if (state->head != Z_NULL)
725: state->head->name = Z_NULL;
726: state->length = 0;
727: state->mode = COMMENT;
728: /* FALL THROUGH */
729: case COMMENT:
730: if (state->flags & 0x1000) {
731: if (have == 0) goto inf_leave;
732: copy = 0;
733: do {
734: len = (unsigned)(next[copy++]);
735: if (state->head != Z_NULL &&
736: state->head->comment != Z_NULL &&
737: state->length < state->head->comm_max)
738: state->head->comment[state->length++] = len;
739: } while (len && copy < have);
740: if (state->flags & 0x0200)
741: state->check = crc32(state->check, next, copy);
742: have -= copy;
743: next += copy;
744: if (len) goto inf_leave;
745: }
746: else if (state->head != Z_NULL)
747: state->head->comment = Z_NULL;
748: state->mode = HCRC;
749: /* FALL THROUGH */
750: case HCRC:
751: if (state->flags & 0x0200) {
752: NEEDBITS(16);
753: if (hold != (state->check & 0xffff)) {
754: strm->msg = (char *)"header crc mismatch";
755: state->mode = BAD;
756: break;
757: }
758: INITBITS();
759: }
760: if (state->head != Z_NULL) {
761: state->head->hcrc = (int)((state->flags >> 9) & 1);
762: state->head->done = 1;
763: }
764: strm->adler = state->check = crc32(0L, Z_NULL, 0);
765: state->mode = TYPE;
766: break;
767: #endif
768: case DICTID:
769: NEEDBITS(32);
770: strm->adler = state->check = REVERSE(hold);
771: INITBITS();
772: state->mode = DICT;
773: /* FALL THROUGH */
774: case DICT:
775: if (state->havedict == 0) {
776: RESTORE();
777: return Z_NEED_DICT;
778: }
779: strm->adler = state->check = adler32(0L, Z_NULL, 0);
780: state->mode = TYPE;
781: /* FALL THROUGH */
782: case TYPE:
783: if (flush == Z_BLOCK) goto inf_leave;
784: /* FALL THROUGH */
785: case TYPEDO:
786: if (state->last) {
787: BYTEBITS();
788: state->mode = CHECK;
789: break;
790: }
791: NEEDBITS(3);
792: state->last = BITS(1);
793: DROPBITS(1);
794: switch (BITS(2)) {
795: case 0: /* stored block */
796: Tracev((stderr, "inflate: stored block%s\n",
797: state->last ? " (last)" : ""));
798: state->mode = STORED;
799: break;
800: case 1: /* fixed block */
801: fixedtables(state);
802: Tracev((stderr, "inflate: fixed codes block%s\n",
803: state->last ? " (last)" : ""));
804: state->mode = LEN; /* decode codes */
805: break;
806: case 2: /* dynamic block */
807: Tracev((stderr, "inflate: dynamic codes block%s\n",
808: state->last ? " (last)" : ""));
809: state->mode = TABLE;
810: break;
811: case 3:
812: strm->msg = (char *)"invalid block type";
813: state->mode = BAD;
814: }
815: DROPBITS(2);
816: break;
817: case STORED:
818: BYTEBITS(); /* go to byte boundary */
819: NEEDBITS(32);
820: if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
821: strm->msg = (char *)"invalid stored block lengths";
822: state->mode = BAD;
823: break;
824: }
825: state->length = (unsigned)hold & 0xffff;
826: Tracev((stderr, "inflate: stored length %u\n",
827: state->length));
828: INITBITS();
829: state->mode = COPY;
830: /* FALL THROUGH */
831: case COPY:
832: copy = state->length;
833: if (copy) {
834: if (copy > have) copy = have;
835: if (copy > left) copy = left;
836: if (copy == 0) goto inf_leave;
837: zmemcpy(put, next, copy);
838: have -= copy;
839: next += copy;
840: left -= copy;
841: put += copy;
842: state->length -= copy;
843: break;
844: }
845: Tracev((stderr, "inflate: stored end\n"));
846: state->mode = TYPE;
847: break;
848: case TABLE:
849: NEEDBITS(14);
850: state->nlen = BITS(5) + 257;
851: DROPBITS(5);
852: state->ndist = BITS(5) + 1;
853: DROPBITS(5);
854: state->ncode = BITS(4) + 4;
855: DROPBITS(4);
856: #ifndef PKZIP_BUG_WORKAROUND
857: if (state->nlen > 286 || state->ndist > 30) {
858: strm->msg = (char *)"too many length or distance symbols";
859: state->mode = BAD;
860: break;
861: }
862: #endif
863: Tracev((stderr, "inflate: table sizes ok\n"));
864: state->have = 0;
865: state->mode = LENLENS;
866: /* FALL THROUGH */
867: case LENLENS:
868: while (state->have < state->ncode) {
869: NEEDBITS(3);
870: state->lens[order[state->have++]] = (unsigned short)BITS(3);
871: DROPBITS(3);
872: }
873: while (state->have < 19)
874: state->lens[order[state->have++]] = 0;
875: state->next = state->codes;
876: state->lencode = (code const FAR *)(state->next);
877: state->lenbits = 7;
878: ret = inflate_table(CODES, state->lens, 19, &(state->next),
879: &(state->lenbits), state->work);
880: if (ret) {
881: strm->msg = (char *)"invalid code lengths set";
882: state->mode = BAD;
883: break;
884: }
885: Tracev((stderr, "inflate: code lengths ok\n"));
886: state->have = 0;
887: state->mode = CODELENS;
888: /* FALL THROUGH */
889: case CODELENS:
890: while (state->have < state->nlen + state->ndist) {
891: for (;;) {
892: this = state->lencode[BITS(state->lenbits)];
893: if ((unsigned)(this.bits) <= bits) break;
894: PULLBYTE();
895: }
896: if (this.val < 16) {
897: NEEDBITS(this.bits);
898: DROPBITS(this.bits);
899: state->lens[state->have++] = this.val;
900: }
901: else {
902: if (this.val == 16) {
903: NEEDBITS(this.bits + 2);
904: DROPBITS(this.bits);
905: if (state->have == 0) {
906: strm->msg = (char *)"invalid bit length repeat";
907: state->mode = BAD;
908: break;
909: }
910: len = state->lens[state->have - 1];
911: copy = 3 + BITS(2);
912: DROPBITS(2);
913: }
914: else if (this.val == 17) {
915: NEEDBITS(this.bits + 3);
916: DROPBITS(this.bits);
917: len = 0;
918: copy = 3 + BITS(3);
919: DROPBITS(3);
920: }
921: else {
922: NEEDBITS(this.bits + 7);
923: DROPBITS(this.bits);
924: len = 0;
925: copy = 11 + BITS(7);
926: DROPBITS(7);
927: }
928: if (state->have + copy > state->nlen + state->ndist) {
929: strm->msg = (char *)"invalid bit length repeat";
930: state->mode = BAD;
931: break;
932: }
933: while (copy--)
934: state->lens[state->have++] = (unsigned short)len;
935: }
936: }
937:
938: /* handle error breaks in while */
939: if (state->mode == BAD) break;
940:
941: /* build code tables */
942: state->next = state->codes;
943: state->lencode = (code const FAR *)(state->next);
944: state->lenbits = 9;
945: ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
946: &(state->lenbits), state->work);
947: if (ret) {
948: strm->msg = (char *)"invalid literal/lengths set";
949: state->mode = BAD;
950: break;
951: }
952: state->distcode = (code const FAR *)(state->next);
953: state->distbits = 6;
954: ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
955: &(state->next), &(state->distbits), state->work);
956: if (ret) {
957: strm->msg = (char *)"invalid distances set";
958: state->mode = BAD;
959: break;
960: }
961: Tracev((stderr, "inflate: codes ok\n"));
962: state->mode = LEN;
963: /* FALL THROUGH */
964: case LEN:
965: if (have >= 6 && left >= 258) {
966: RESTORE();
967: inflate_fast(strm, out);
968: LOAD();
969: break;
970: }
971: for (;;) {
972: this = state->lencode[BITS(state->lenbits)];
973: if ((unsigned)(this.bits) <= bits) break;
974: PULLBYTE();
975: }
976: if (this.op && (this.op & 0xf0) == 0) {
977: last = this;
978: for (;;) {
979: this = state->lencode[last.val +
980: (BITS(last.bits + last.op) >> last.bits)];
981: if ((unsigned)(last.bits + this.bits) <= bits) break;
982: PULLBYTE();
983: }
984: DROPBITS(last.bits);
985: }
986: DROPBITS(this.bits);
987: state->length = (unsigned)this.val;
988: if ((int)(this.op) == 0) {
989: Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?
990: "inflate: literal '%c'\n" :
991: "inflate: literal 0x%02x\n", this.val));
992: state->mode = LIT;
993: break;
994: }
995: if (this.op & 32) {
996: Tracevv((stderr, "inflate: end of block\n"));
997: state->mode = TYPE;
998: break;
999: }
1000: if (this.op & 64) {
1001: strm->msg = (char *)"invalid literal/length code";
1002: state->mode = BAD;
1003: break;
1004: }
1005: state->extra = (unsigned)(this.op) & 15;
1006: state->mode = LENEXT;
1007: /* FALL THROUGH */
1008: case LENEXT:
1009: if (state->extra) {
1010: NEEDBITS(state->extra);
1011: state->length += BITS(state->extra);
1012: DROPBITS(state->extra);
1013: }
1014: Tracevv((stderr, "inflate: length %u\n", state->length));
1015: state->mode = DIST;
1016: /* FALL THROUGH */
1017: case DIST:
1018: for (;;) {
1019: this = state->distcode[BITS(state->distbits)];
1020: if ((unsigned)(this.bits) <= bits) break;
1021: PULLBYTE();
1022: }
1023: if ((this.op & 0xf0) == 0) {
1024: last = this;
1025: for (;;) {
1026: this = state->distcode[last.val +
1027: (BITS(last.bits + last.op) >> last.bits)];
1028: if ((unsigned)(last.bits + this.bits) <= bits) break;
1029: PULLBYTE();
1030: }
1031: DROPBITS(last.bits);
1032: }
1033: DROPBITS(this.bits);
1034: if (this.op & 64) {
1035: strm->msg = (char *)"invalid distance code";
1036: state->mode = BAD;
1037: break;
1038: }
1039: state->offset = (unsigned)this.val;
1040: state->extra = (unsigned)(this.op) & 15;
1041: state->mode = DISTEXT;
1042: /* FALL THROUGH */
1043: case DISTEXT:
1044: if (state->extra) {
1045: NEEDBITS(state->extra);
1046: state->offset += BITS(state->extra);
1047: DROPBITS(state->extra);
1048: }
1049: #ifdef INFLATE_STRICT
1050: if (state->offset > state->dmax) {
1051: strm->msg = (char *)"invalid distance too far back";
1052: state->mode = BAD;
1053: break;
1054: }
1055: #endif
1056: if (state->offset > state->whave + out - left) {
1057: strm->msg = (char *)"invalid distance too far back";
1058: state->mode = BAD;
1059: break;
1060: }
1061: Tracevv((stderr, "inflate: distance %u\n", state->offset));
1062: state->mode = MATCH;
1063: /* FALL THROUGH */
1064: case MATCH:
1065: if (left == 0) goto inf_leave;
1066: copy = out - left;
1067: if (state->offset > copy) { /* copy from window */
1068: copy = state->offset - copy;
1069: if (copy > state->write) {
1070: copy -= state->write;
1071: from = state->window + (state->wsize - copy);
1072: }
1073: else
1074: from = state->window + (state->write - copy);
1075: if (copy > state->length) copy = state->length;
1076: }
1077: else { /* copy from output */
1078: from = put - state->offset;
1079: copy = state->length;
1080: }
1081: if (copy > left) copy = left;
1082: left -= copy;
1083: state->length -= copy;
1084: do {
1085: *put++ = *from++;
1086: } while (--copy);
1087: if (state->length == 0) state->mode = LEN;
1088: break;
1089: case LIT:
1090: if (left == 0) goto inf_leave;
1091: *put++ = (unsigned char)(state->length);
1092: left--;
1093: state->mode = LEN;
1094: break;
1095: case CHECK:
1096: if (state->wrap) {
1097: NEEDBITS(32);
1098: out -= left;
1099: strm->total_out += out;
1100: state->total += out;
1101: if (out)
1102: strm->adler = state->check =
1103: UPDATE(state->check, put - out, out);
1104: out = left;
1105: if ((
1106: #ifdef GUNZIP
1107: state->flags ? hold :
1108: #endif
1109: REVERSE(hold)) != state->check) {
1110: strm->msg = (char *)"incorrect data check";
1111: state->mode = BAD;
1112: break;
1113: }
1114: INITBITS();
1115: Tracev((stderr, "inflate: check matches trailer\n"));
1116: }
1117: #ifdef GUNZIP
1118: state->mode = LENGTH;
1119: /* FALL THROUGH */
1120: case LENGTH:
1121: if (state->wrap && state->flags) {
1122: NEEDBITS(32);
1123: if (hold != (state->total & 0xffffffffUL)) {
1124: strm->msg = (char *)"incorrect length check";
1125: state->mode = BAD;
1126: break;
1127: }
1128: INITBITS();
1129: Tracev((stderr, "inflate: length matches trailer\n"));
1130: }
1131: #endif
1132: state->mode = DONE;
1133: /* FALL THROUGH */
1134: case DONE:
1135: ret = Z_STREAM_END;
1136: goto inf_leave;
1137: case BAD:
1138: ret = Z_DATA_ERROR;
1139: goto inf_leave;
1140: case MEM:
1141: return Z_MEM_ERROR;
1142: case SYNC:
1143: default:
1144: return Z_STREAM_ERROR;
1145: }
1146:
1147: /*
1148: Return from inflate(), updating the total counts and the check value.
1149: If there was no progress during the inflate() call, return a buffer
1150: error. Call updatewindow() to create and/or update the window state.
1151: Note: a memory error from inflate() is non-recoverable.
1152: */
1153: inf_leave:
1154: RESTORE();
1155: if (state->wsize || (state->mode < CHECK && out != strm->avail_out))
1156: if (updatewindow(strm, out)) {
1157: state->mode = MEM;
1158: return Z_MEM_ERROR;
1159: }
1160: in -= strm->avail_in;
1161: out -= strm->avail_out;
1162: strm->total_in += in;
1163: strm->total_out += out;
1164: state->total += out;
1165: if (state->wrap && out)
1166: strm->adler = state->check =
1167: UPDATE(state->check, strm->next_out - out, out);
1168: strm->data_type = state->bits + (state->last ? 64 : 0) +
1169: (state->mode == TYPE ? 128 : 0);
1170: if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1171: ret = Z_BUF_ERROR;
1172: return ret;
1173: }
1174:
1175: int ZEXPORT inflateEnd(strm)
1176: z_streamp strm;
1177: {
1178: struct inflate_state FAR *state;
1179: if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
1180: return Z_STREAM_ERROR;
1181: state = (struct inflate_state FAR *)strm->state;
1182: if (state->window != Z_NULL) ZFREE(strm, state->window);
1183: ZFREE(strm, strm->state);
1184: strm->state = Z_NULL;
1185: Tracev((stderr, "inflate: end\n"));
1186: return Z_OK;
1187: }
1188:
1189: int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
1190: z_streamp strm;
1191: const Bytef *dictionary;
1192: uInt dictLength;
1193: {
1194: struct inflate_state FAR *state;
1195: unsigned long id;
1196:
1197: /* check state */
1198: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1199: state = (struct inflate_state FAR *)strm->state;
1200: if (state->wrap != 0 && state->mode != DICT)
1201: return Z_STREAM_ERROR;
1202:
1203: /* check for correct dictionary id */
1204: if (state->mode == DICT) {
1205: id = adler32(0L, Z_NULL, 0);
1206: id = adler32(id, dictionary, dictLength);
1207: if (id != state->check)
1208: return Z_DATA_ERROR;
1209: }
1210:
1211: /* copy dictionary to window */
1212: if (updatewindow(strm, strm->avail_out)) {
1213: state->mode = MEM;
1214: return Z_MEM_ERROR;
1215: }
1216: if (dictLength > state->wsize) {
1217: zmemcpy(state->window, dictionary + dictLength - state->wsize,
1218: state->wsize);
1219: state->whave = state->wsize;
1220: }
1221: else {
1222: zmemcpy(state->window + state->wsize - dictLength, dictionary,
1223: dictLength);
1224: state->whave = dictLength;
1225: }
1226: state->havedict = 1;
1227: Tracev((stderr, "inflate: dictionary set\n"));
1228: return Z_OK;
1229: }
1230:
1231: int ZEXPORT inflateGetHeader(strm, head)
1232: z_streamp strm;
1233: gz_headerp head;
1234: {
1235: struct inflate_state FAR *state;
1236:
1237: /* check state */
1238: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1239: state = (struct inflate_state FAR *)strm->state;
1240: if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1241:
1242: /* save header structure */
1243: state->head = head;
1244: head->done = 0;
1245: return Z_OK;
1246: }
1247:
1248: /*
1249: Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
1250: or when out of input. When called, *have is the number of pattern bytes
1251: found in order so far, in 0..3. On return *have is updated to the new
1252: state. If on return *have equals four, then the pattern was found and the
1253: return value is how many bytes were read including the last byte of the
1254: pattern. If *have is less than four, then the pattern has not been found
1255: yet and the return value is len. In the latter case, syncsearch() can be
1256: called again with more data and the *have state. *have is initialized to
1257: zero for the first call.
1258: */
1259: local unsigned syncsearch(have, buf, len)
1260: unsigned FAR *have;
1261: unsigned char FAR *buf;
1262: unsigned len;
1263: {
1264: unsigned got;
1265: unsigned next;
1266:
1267: got = *have;
1268: next = 0;
1269: while (next < len && got < 4) {
1270: if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1271: got++;
1272: else if (buf[next])
1273: got = 0;
1274: else
1275: got = 4 - got;
1276: next++;
1277: }
1278: *have = got;
1279: return next;
1280: }
1281:
1282: int ZEXPORT inflateSync(strm)
1283: z_streamp strm;
1284: {
1285: unsigned len; /* number of bytes to look at or looked at */
1286: unsigned long in, out; /* temporary to save total_in and total_out */
1287: unsigned char buf[4]; /* to restore bit buffer to byte string */
1288: struct inflate_state FAR *state;
1289:
1290: /* check parameters */
1291: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1292: state = (struct inflate_state FAR *)strm->state;
1293: if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1294:
1295: /* if first time, start search in bit buffer */
1296: if (state->mode != SYNC) {
1297: state->mode = SYNC;
1298: state->hold <<= state->bits & 7;
1299: state->bits -= state->bits & 7;
1300: len = 0;
1301: while (state->bits >= 8) {
1302: buf[len++] = (unsigned char)(state->hold);
1303: state->hold >>= 8;
1304: state->bits -= 8;
1305: }
1306: state->have = 0;
1307: syncsearch(&(state->have), buf, len);
1308: }
1309:
1310: /* search available input */
1311: len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1312: strm->avail_in -= len;
1313: strm->next_in += len;
1314: strm->total_in += len;
1315:
1316: /* return no joy or set up to restart inflate() on a new block */
1317: if (state->have != 4) return Z_DATA_ERROR;
1318: in = strm->total_in; out = strm->total_out;
1319: inflateReset(strm);
1320: strm->total_in = in; strm->total_out = out;
1321: state->mode = TYPE;
1322: return Z_OK;
1323: }
1324:
1325: /*
1326: Returns true if inflate is currently at the end of a block generated by
1327: Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1328: implementation to provide an additional safety check. PPP uses
1329: Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1330: block. When decompressing, PPP checks that at the end of input packet,
1331: inflate is waiting for these length bytes.
1332: */
1333: int ZEXPORT inflateSyncPoint(strm)
1334: z_streamp strm;
1335: {
1336: struct inflate_state FAR *state;
1337:
1338: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1339: state = (struct inflate_state FAR *)strm->state;
1340: return state->mode == STORED && state->bits == 0;
1341: }
1342:
1343: int ZEXPORT inflateCopy(dest, source)
1344: z_streamp dest;
1345: z_streamp source;
1346: {
1347: struct inflate_state FAR *state;
1348: struct inflate_state FAR *copy;
1349: unsigned char FAR *window;
1350: unsigned wsize;
1351:
1352: /* check input */
1353: if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
1354: source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
1355: return Z_STREAM_ERROR;
1356: state = (struct inflate_state FAR *)source->state;
1357:
1358: /* allocate space */
1359: copy = (struct inflate_state FAR *)
1360: ZALLOC(source, 1, sizeof(struct inflate_state));
1361: if (copy == Z_NULL) return Z_MEM_ERROR;
1362: window = Z_NULL;
1363: if (state->window != Z_NULL) {
1364: window = (unsigned char FAR *)
1365: ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1366: if (window == Z_NULL) {
1367: ZFREE(source, copy);
1368: return Z_MEM_ERROR;
1369: }
1370: }
1371:
1372: /* copy state */
1373: zmemcpy(dest, source, sizeof(z_stream));
1374: zmemcpy(copy, state, sizeof(struct inflate_state));
1375: if (state->lencode >= state->codes &&
1376: state->lencode <= state->codes + ENOUGH - 1) {
1377: copy->lencode = copy->codes + (state->lencode - state->codes);
1378: copy->distcode = copy->codes + (state->distcode - state->codes);
1379: }
1380: copy->next = copy->codes + (state->next - state->codes);
1381: if (window != Z_NULL) {
1382: wsize = 1U << state->wbits;
1383: zmemcpy(window, state->window, wsize);
1384: }
1385: copy->window = window;
1386: dest->state = (struct internal_state FAR *)copy;
1387: return Z_OK;
1388: }
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