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git.saurik.com Git - wxWidgets.git/blob - src/zlib/infback.c
1 /* infback.c -- inflate using a call-back interface
2 * Copyright (C) 1995-2005 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
7 This code is largely copied from inflate.c. Normally either infback.o or
8 inflate.o would be linked into an application--not both. The interface
9 with inffast.c is retained so that optimized assembler-coded versions of
10 inflate_fast() can be used with either inflate.c or infback.c.
18 /* function prototypes */
19 local
void fixedtables
OF((struct inflate_state FAR
*state
));
22 strm provides memory allocation functions in zalloc and zfree, or
23 Z_NULL to use the library memory allocation functions.
25 windowBits is in the range 8..15, and window is a user-supplied
26 window and output buffer that is 2**windowBits bytes.
28 int ZEXPORT
inflateBackInit_(strm
, windowBits
, window
, version
, stream_size
)
31 unsigned char FAR
*window
;
35 struct inflate_state FAR
*state
;
37 if (version
== Z_NULL
|| version
[0] != ZLIB_VERSION
[0] ||
38 stream_size
!= (int)(sizeof(z_stream
)))
39 return Z_VERSION_ERROR
;
40 if (strm
== Z_NULL
|| window
== Z_NULL
||
41 windowBits
< 8 || windowBits
> 15)
42 return Z_STREAM_ERROR
;
43 strm
->msg
= Z_NULL
; /* in case we return an error */
44 if (strm
->zalloc
== (alloc_func
)0) {
45 strm
->zalloc
= zcalloc
;
46 strm
->opaque
= (voidpf
)0;
48 if (strm
->zfree
== (free_func
)0) strm
->zfree
= zcfree
;
49 state
= (struct inflate_state FAR
*)ZALLOC(strm
, 1,
50 sizeof(struct inflate_state
));
51 if (state
== Z_NULL
) return Z_MEM_ERROR
;
52 Tracev((stderr
, "inflate: allocated\n"));
53 strm
->state
= (struct internal_state FAR
*)state
;
55 state
->wbits
= windowBits
;
56 state
->wsize
= 1U << windowBits
;
57 state
->window
= window
;
64 Return state with length and distance decoding tables and index sizes set to
65 fixed code decoding. Normally this returns fixed tables from inffixed.h.
66 If BUILDFIXED is defined, then instead this routine builds the tables the
67 first time it's called, and returns those tables the first time and
68 thereafter. This reduces the size of the code by about 2K bytes, in
69 exchange for a little execution time. However, BUILDFIXED should not be
70 used for threaded applications, since the rewriting of the tables and virgin
71 may not be thread-safe.
73 local
void fixedtables(state
)
74 struct inflate_state FAR
*state
;
77 static int virgin
= 1;
78 static code
*lenfix
, *distfix
;
79 static code fixed
[544];
81 /* build fixed huffman tables if first call (may not be thread safe) */
86 /* literal/length table */
88 while (sym
< 144) state
->lens
[sym
++] = 8;
89 while (sym
< 256) state
->lens
[sym
++] = 9;
90 while (sym
< 280) state
->lens
[sym
++] = 7;
91 while (sym
< 288) state
->lens
[sym
++] = 8;
95 inflate_table(LENS
, state
->lens
, 288, &(next
), &(bits
), state
->work
);
99 while (sym
< 32) state
->lens
[sym
++] = 5;
102 inflate_table(DISTS
, state
->lens
, 32, &(next
), &(bits
), state
->work
);
104 /* do this just once */
107 #else /* !BUILDFIXED */
108 # include "inffixed.h"
109 #endif /* BUILDFIXED */
110 state
->lencode
= lenfix
;
112 state
->distcode
= distfix
;
116 /* Macros for inflateBack(): */
118 /* Load returned state from inflate_fast() */
121 put = strm->next_out; \
122 left = strm->avail_out; \
123 next = strm->next_in; \
124 have = strm->avail_in; \
125 hold = state->hold; \
126 bits = state->bits; \
129 /* Set state from registers for inflate_fast() */
132 strm->next_out = put; \
133 strm->avail_out = left; \
134 strm->next_in = next; \
135 strm->avail_in = have; \
136 state->hold = hold; \
137 state->bits = bits; \
140 /* Clear the input bit accumulator */
147 /* Assure that some input is available. If input is requested, but denied,
148 then return a Z_BUF_ERROR from inflateBack(). */
152 have = in(in_desc, &next); \
161 /* Get a byte of input into the bit accumulator, or return from inflateBack()
162 with an error if there is no input available. */
167 hold += (unsigned long)(*next++) << bits; \
171 /* Assure that there are at least n bits in the bit accumulator. If there is
172 not enough available input to do that, then return from inflateBack() with
174 #define NEEDBITS(n) \
176 while (bits < (unsigned)(n)) \
180 /* Return the low n bits of the bit accumulator (n < 16) */
182 ((unsigned)hold & ((1U << (n)) - 1))
184 /* Remove n bits from the bit accumulator */
185 #define DROPBITS(n) \
188 bits -= (unsigned)(n); \
191 /* Remove zero to seven bits as needed to go to a byte boundary */
198 /* Assure that some output space is available, by writing out the window
199 if it's full. If the write fails, return from inflateBack() with a
204 put = state->window; \
205 left = state->wsize; \
206 state->whave = left; \
207 if (out(out_desc, put, left)) { \
215 strm provides the memory allocation functions and window buffer on input,
216 and provides information on the unused input on return. For Z_DATA_ERROR
217 returns, strm will also provide an error message.
219 in() and out() are the call-back input and output functions. When
220 inflateBack() needs more input, it calls in(). When inflateBack() has
221 filled the window with output, or when it completes with data in the
222 window, it calls out() to write out the data. The application must not
223 change the provided input until in() is called again or inflateBack()
224 returns. The application must not change the window/output buffer until
225 inflateBack() returns.
227 in() and out() are called with a descriptor parameter provided in the
228 inflateBack() call. This parameter can be a structure that provides the
229 information required to do the read or write, as well as accumulated
230 information on the input and output such as totals and check values.
232 in() should return zero on failure. out() should return non-zero on
233 failure. If either in() or out() fails, than inflateBack() returns a
234 Z_BUF_ERROR. strm->next_in can be checked for Z_NULL to see whether it
235 was in() or out() that caused in the error. Otherwise, inflateBack()
236 returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
237 error, or Z_MEM_ERROR if it could not allocate memory for the state.
238 inflateBack() can also return Z_STREAM_ERROR if the input parameters
239 are not correct, i.e. strm is Z_NULL or the state was not initialized.
241 int ZEXPORT
inflateBack(strm
, in
, in_desc
, out
, out_desc
)
248 struct inflate_state FAR
*state
;
249 unsigned char FAR
*next
; /* next input */
250 unsigned char FAR
*put
; /* next output */
251 unsigned have
, left
; /* available input and output */
252 unsigned long hold
; /* bit buffer */
253 unsigned bits
; /* bits in bit buffer */
254 unsigned copy
; /* number of stored or match bytes to copy */
255 unsigned char FAR
*from
; /* where to copy match bytes from */
256 code
this; /* current decoding table entry */
257 code last
; /* parent table entry */
258 unsigned len
; /* length to copy for repeats, bits to drop */
259 int ret
; /* return code */
260 static const unsigned short order
[19] = /* permutation of code lengths */
261 {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
263 /* Check that the strm exists and that the state was initialized */
264 if (strm
== Z_NULL
|| strm
->state
== Z_NULL
)
265 return Z_STREAM_ERROR
;
266 state
= (struct inflate_state FAR
*)strm
->state
;
268 /* Reset the state */
273 next
= strm
->next_in
;
274 have
= next
!= Z_NULL
? strm
->avail_in
: 0;
280 /* Inflate until end of block marked as last */
282 switch (state
->mode
) {
284 /* determine and dispatch block type */
291 state
->last
= BITS(1);
294 case 0: /* stored block */
295 Tracev((stderr
, "inflate: stored block%s\n",
296 state
->last
? " (last)" : ""));
297 state
->mode
= STORED
;
299 case 1: /* fixed block */
301 Tracev((stderr
, "inflate: fixed codes block%s\n",
302 state
->last
? " (last)" : ""));
303 state
->mode
= LEN
; /* decode codes */
305 case 2: /* dynamic block */
306 Tracev((stderr
, "inflate: dynamic codes block%s\n",
307 state
->last
? " (last)" : ""));
311 strm
->msg
= (char *)"invalid block type";
318 /* get and verify stored block length */
319 BYTEBITS(); /* go to byte boundary */
321 if ((hold
& 0xffff) != ((hold
>> 16) ^ 0xffff)) {
322 strm
->msg
= (char *)"invalid stored block lengths";
326 state
->length
= (unsigned)hold
& 0xffff;
327 Tracev((stderr
, "inflate: stored length %u\n",
331 /* copy stored block from input to output */
332 while (state
->length
!= 0) {
333 copy
= state
->length
;
336 if (copy
> have
) copy
= have
;
337 if (copy
> left
) copy
= left
;
338 zmemcpy(put
, next
, copy
);
343 state
->length
-= copy
;
345 Tracev((stderr
, "inflate: stored end\n"));
350 /* get dynamic table entries descriptor */
352 state
->nlen
= BITS(5) + 257;
354 state
->ndist
= BITS(5) + 1;
356 state
->ncode
= BITS(4) + 4;
358 #ifndef PKZIP_BUG_WORKAROUND
359 if (state
->nlen
> 286 || state
->ndist
> 30) {
360 strm
->msg
= (char *)"too many length or distance symbols";
365 Tracev((stderr
, "inflate: table sizes ok\n"));
367 /* get code length code lengths (not a typo) */
369 while (state
->have
< state
->ncode
) {
371 state
->lens
[order
[state
->have
++]] = (unsigned short)BITS(3);
374 while (state
->have
< 19)
375 state
->lens
[order
[state
->have
++]] = 0;
376 state
->next
= state
->codes
;
377 state
->lencode
= (code
const FAR
*)(state
->next
);
379 ret
= inflate_table(CODES
, state
->lens
, 19, &(state
->next
),
380 &(state
->lenbits
), state
->work
);
382 strm
->msg
= (char *)"invalid code lengths set";
386 Tracev((stderr
, "inflate: code lengths ok\n"));
388 /* get length and distance code code lengths */
390 while (state
->have
< state
->nlen
+ state
->ndist
) {
392 this = state
->lencode
[BITS(state
->lenbits
)];
393 if ((unsigned)(this.bits
) <= bits
) break;
399 state
->lens
[state
->have
++] = this.val
;
402 if (this.val
== 16) {
403 NEEDBITS(this.bits
+ 2);
405 if (state
->have
== 0) {
406 strm
->msg
= (char *)"invalid bit length repeat";
410 len
= (unsigned)(state
->lens
[state
->have
- 1]);
414 else if (this.val
== 17) {
415 NEEDBITS(this.bits
+ 3);
422 NEEDBITS(this.bits
+ 7);
428 if (state
->have
+ copy
> state
->nlen
+ state
->ndist
) {
429 strm
->msg
= (char *)"invalid bit length repeat";
434 state
->lens
[state
->have
++] = (unsigned short)len
;
438 /* handle error breaks in while */
439 if (state
->mode
== BAD
) break;
441 /* build code tables */
442 state
->next
= state
->codes
;
443 state
->lencode
= (code
const FAR
*)(state
->next
);
445 ret
= inflate_table(LENS
, state
->lens
, state
->nlen
, &(state
->next
),
446 &(state
->lenbits
), state
->work
);
448 strm
->msg
= (char *)"invalid literal/lengths set";
452 state
->distcode
= (code
const FAR
*)(state
->next
);
454 ret
= inflate_table(DISTS
, state
->lens
+ state
->nlen
, state
->ndist
,
455 &(state
->next
), &(state
->distbits
), state
->work
);
457 strm
->msg
= (char *)"invalid distances set";
461 Tracev((stderr
, "inflate: codes ok\n"));
465 /* use inflate_fast() if we have enough input and output */
466 if (have
>= 6 && left
>= 258) {
468 if (state
->whave
< state
->wsize
)
469 state
->whave
= state
->wsize
- left
;
470 inflate_fast(strm
, state
->wsize
);
475 /* get a literal, length, or end-of-block code */
477 this = state
->lencode
[BITS(state
->lenbits
)];
478 if ((unsigned)(this.bits
) <= bits
) break;
481 if (this.op
&& (this.op
& 0xf0) == 0) {
484 this = state
->lencode
[last
.val
+
485 (BITS(last
.bits
+ last
.op
) >> last
.bits
)];
486 if ((unsigned)(last
.bits
+ this.bits
) <= bits
) break;
492 state
->length
= (unsigned)this.val
;
494 /* process literal */
496 Tracevv((stderr
, this.val
>= 0x20 && this.val
< 0x7f ?
497 "inflate: literal '%c'\n" :
498 "inflate: literal 0x%02x\n", this.val
));
500 *put
++ = (unsigned char)(state
->length
);
506 /* process end of block */
508 Tracevv((stderr
, "inflate: end of block\n"));
515 strm
->msg
= (char *)"invalid literal/length code";
520 /* length code -- get extra bits, if any */
521 state
->extra
= (unsigned)(this.op
) & 15;
522 if (state
->extra
!= 0) {
523 NEEDBITS(state
->extra
);
524 state
->length
+= BITS(state
->extra
);
525 DROPBITS(state
->extra
);
527 Tracevv((stderr
, "inflate: length %u\n", state
->length
));
529 /* get distance code */
531 this = state
->distcode
[BITS(state
->distbits
)];
532 if ((unsigned)(this.bits
) <= bits
) break;
535 if ((this.op
& 0xf0) == 0) {
538 this = state
->distcode
[last
.val
+
539 (BITS(last
.bits
+ last
.op
) >> last
.bits
)];
540 if ((unsigned)(last
.bits
+ this.bits
) <= bits
) break;
547 strm
->msg
= (char *)"invalid distance code";
551 state
->offset
= (unsigned)this.val
;
553 /* get distance extra bits, if any */
554 state
->extra
= (unsigned)(this.op
) & 15;
555 if (state
->extra
!= 0) {
556 NEEDBITS(state
->extra
);
557 state
->offset
+= BITS(state
->extra
);
558 DROPBITS(state
->extra
);
560 if (state
->offset
> state
->wsize
- (state
->whave
< state
->wsize
?
562 strm
->msg
= (char *)"invalid distance too far back";
566 Tracevv((stderr
, "inflate: distance %u\n", state
->offset
));
568 /* copy match from window to output */
571 copy
= state
->wsize
- state
->offset
;
577 from
= put
- state
->offset
;
580 if (copy
> state
->length
) copy
= state
->length
;
581 state
->length
-= copy
;
586 } while (state
->length
!= 0);
590 /* inflate stream terminated properly -- write leftover output */
592 if (left
< state
->wsize
) {
593 if (out(out_desc
, state
->window
, state
->wsize
- left
))
602 default: /* can't happen, but makes compilers happy */
603 ret
= Z_STREAM_ERROR
;
607 /* Return unused input */
609 strm
->next_in
= next
;
610 strm
->avail_in
= have
;
614 int ZEXPORT
inflateBackEnd(strm
)
617 if (strm
== Z_NULL
|| strm
->state
== Z_NULL
|| strm
->zfree
== (free_func
)0)
618 return Z_STREAM_ERROR
;
619 ZFREE(strm
, strm
->state
);
620 strm
->state
= Z_NULL
;
621 Tracev((stderr
, "inflate: end\n"));