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/* infback.c -- inflate using a call-back interface
* Copyright (C) 1995-2005 Mark Adler
* Copyright (C) 1995-2009 Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*/
/*
This code is largely copied from inflate.c. Normally either infback.o or
inflate.o would be linked into an application--not both. The interface
with inffast.c is retained so that optimized assembler-coded versions of
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if (state == Z_NULL) return Z_MEM_ERROR;
Tracev((stderr, "inflate: allocated\n"));
strm->state = (struct internal_state FAR *)state;
state->dmax = 32768U;
state->wbits = windowBits;
state->wsize = 1U << windowBits;
state->window = window;
state->write = 0;
state->wnext = 0;
state->whave = 0;
return Z_OK;
}
/*
Return state with length and distance decoding tables and index sizes set to
fixed code decoding. Normally this returns fixed tables from inffixed.h.
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unsigned char FAR *next; /* next input */
unsigned char FAR *put; /* next output */
unsigned have, left; /* available input and output */
unsigned long hold; /* bit buffer */
unsigned bits; /* bits in bit buffer */
unsigned copy; /* number of stored or match bytes to copy */
unsigned char FAR *from; /* where to copy match bytes from */
code this; /* current decoding table entry */
code here; /* current decoding table entry */
code last; /* parent table entry */
unsigned len; /* length to copy for repeats, bits to drop */
int ret; /* return code */
static const unsigned short order[19] = /* permutation of code lengths */
{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
/* Check that the strm exists and that the state was initialized */
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}
Tracev((stderr, "inflate: code lengths ok\n"));
/* get length and distance code code lengths */
state->have = 0;
while (state->have < state->nlen + state->ndist) {
for (;;) {
this = state->lencode[BITS(state->lenbits)];
if ((unsigned)(this.bits) <= bits) break;
here = state->lencode[BITS(state->lenbits)];
if ((unsigned)(here.bits) <= bits) break;
PULLBYTE();
}
if (this.val < 16) {
NEEDBITS(this.bits);
DROPBITS(this.bits);
state->lens[state->have++] = this.val;
if (here.val < 16) {
NEEDBITS(here.bits);
DROPBITS(here.bits);
state->lens[state->have++] = here.val;
}
else {
if (this.val == 16) {
NEEDBITS(this.bits + 2);
DROPBITS(this.bits);
if (here.val == 16) {
NEEDBITS(here.bits + 2);
DROPBITS(here.bits);
if (state->have == 0) {
strm->msg = (char *)"invalid bit length repeat";
state->mode = BAD;
break;
}
len = (unsigned)(state->lens[state->have - 1]);
copy = 3 + BITS(2);
DROPBITS(2);
}
else if (this.val == 17) {
NEEDBITS(this.bits + 3);
DROPBITS(this.bits);
else if (here.val == 17) {
NEEDBITS(here.bits + 3);
DROPBITS(here.bits);
len = 0;
copy = 3 + BITS(3);
DROPBITS(3);
}
else {
NEEDBITS(this.bits + 7);
DROPBITS(this.bits);
NEEDBITS(here.bits + 7);
DROPBITS(here.bits);
len = 0;
copy = 11 + BITS(7);
DROPBITS(7);
}
if (state->have + copy > state->nlen + state->ndist) {
strm->msg = (char *)"invalid bit length repeat";
state->mode = BAD;
break;
}
while (copy--)
state->lens[state->have++] = (unsigned short)len;
}
}
/* handle error breaks in while */
if (state->mode == BAD) break;
/* check for end-of-block code (better have one) */
if (state->lens[256] == 0) {
strm->msg = (char *)"invalid code -- missing end-of-block";
state->mode = BAD;
break;
}
/* build code tables */
/* build code tables -- note: do not change the lenbits or distbits
values here (9 and 6) without reading the comments in inftrees.h
concerning the ENOUGH constants, which depend on those values */
state->next = state->codes;
state->lencode = (code const FAR *)(state->next);
state->lenbits = 9;
ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
&(state->lenbits), state->work);
if (ret) {
strm->msg = (char *)"invalid literal/lengths set";
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inflate_fast(strm, state->wsize);
LOAD();
break;
}
/* get a literal, length, or end-of-block code */
for (;;) {
this = state->lencode[BITS(state->lenbits)];
if ((unsigned)(this.bits) <= bits) break;
here = state->lencode[BITS(state->lenbits)];
if ((unsigned)(here.bits) <= bits) break;
PULLBYTE();
}
if (this.op && (this.op & 0xf0) == 0) {
last = this;
if (here.op && (here.op & 0xf0) == 0) {
last = here;
for (;;) {
this = state->lencode[last.val +
here = state->lencode[last.val +
(BITS(last.bits + last.op) >> last.bits)];
if ((unsigned)(last.bits + this.bits) <= bits) break;
if ((unsigned)(last.bits + here.bits) <= bits) break;
PULLBYTE();
}
DROPBITS(last.bits);
}
DROPBITS(this.bits);
state->length = (unsigned)this.val;
DROPBITS(here.bits);
state->length = (unsigned)here.val;
/* process literal */
if (this.op == 0) {
Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?
if (here.op == 0) {
Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
"inflate: literal '%c'\n" :
"inflate: literal 0x%02x\n", this.val));
"inflate: literal 0x%02x\n", here.val));
ROOM();
*put++ = (unsigned char)(state->length);
left--;
state->mode = LEN;
break;
}
/* process end of block */
if (this.op & 32) {
if (here.op & 32) {
Tracevv((stderr, "inflate: end of block\n"));
state->mode = TYPE;
break;
}
/* invalid code */
if (this.op & 64) {
if (here.op & 64) {
strm->msg = (char *)"invalid literal/length code";
state->mode = BAD;
break;
}
/* length code -- get extra bits, if any */
state->extra = (unsigned)(this.op) & 15;
state->extra = (unsigned)(here.op) & 15;
if (state->extra != 0) {
NEEDBITS(state->extra);
state->length += BITS(state->extra);
DROPBITS(state->extra);
}
Tracevv((stderr, "inflate: length %u\n", state->length));
/* get distance code */
for (;;) {
this = state->distcode[BITS(state->distbits)];
if ((unsigned)(this.bits) <= bits) break;
here = state->distcode[BITS(state->distbits)];
if ((unsigned)(here.bits) <= bits) break;
PULLBYTE();
}
if ((this.op & 0xf0) == 0) {
last = this;
if ((here.op & 0xf0) == 0) {
last = here;
for (;;) {
this = state->distcode[last.val +
here = state->distcode[last.val +
(BITS(last.bits + last.op) >> last.bits)];
if ((unsigned)(last.bits + this.bits) <= bits) break;
if ((unsigned)(last.bits + here.bits) <= bits) break;
PULLBYTE();
}
DROPBITS(last.bits);
}
DROPBITS(this.bits);
if (this.op & 64) {
DROPBITS(here.bits);
if (here.op & 64) {
strm->msg = (char *)"invalid distance code";
state->mode = BAD;
break;
}
state->offset = (unsigned)this.val;
state->offset = (unsigned)here.val;
/* get distance extra bits, if any */
state->extra = (unsigned)(this.op) & 15;
state->extra = (unsigned)(here.op) & 15;
if (state->extra != 0) {
NEEDBITS(state->extra);
state->offset += BITS(state->extra);
DROPBITS(state->extra);
}
if (state->offset > state->wsize - (state->whave < state->wsize ?
left : 0)) {
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