This source file includes following definitions.
- inflate_fast
#include "zutil.h"
#include "inftrees.h"
#include "inflate.h"
#include "inffast.h"
#ifndef ASMINF
#ifdef POSTINC
# define OFF 0
# define PUP(a) *(a)++
#else
# define OFF 1
# define PUP(a) *++(a)
#endif
void ZLIB_INTERNAL inflate_fast(strm, start)
z_streamp strm;
unsigned start;
{
struct inflate_state FAR *state;
unsigned char FAR *in;
unsigned char FAR *last;
unsigned char FAR *out;
unsigned char FAR *beg;
unsigned char FAR *end;
#ifdef INFLATE_STRICT
unsigned dmax;
#endif
unsigned wsize;
unsigned whave;
unsigned wnext;
unsigned char FAR *window;
unsigned long hold;
unsigned bits;
code const FAR *lcode;
code const FAR *dcode;
unsigned lmask;
unsigned dmask;
code here;
unsigned op;
unsigned len;
unsigned dist;
unsigned char FAR *from;
state = (struct inflate_state FAR *)strm->state;
in = strm->next_in - OFF;
last = in + (strm->avail_in - 5);
out = strm->next_out - OFF;
beg = out - (start - strm->avail_out);
end = out + (strm->avail_out - 257);
#ifdef INFLATE_STRICT
dmax = state->dmax;
#endif
wsize = state->wsize;
whave = state->whave;
wnext = state->wnext;
window = state->window;
hold = state->hold;
bits = state->bits;
lcode = state->lencode;
dcode = state->distcode;
lmask = (1U << state->lenbits) - 1;
dmask = (1U << state->distbits) - 1;
do {
if (bits < 15) {
hold += (unsigned long)(PUP(in)) << bits;
bits += 8;
hold += (unsigned long)(PUP(in)) << bits;
bits += 8;
}
here = lcode[hold & lmask];
dolen:
op = (unsigned)(here.bits);
hold >>= op;
bits -= op;
op = (unsigned)(here.op);
if (op == 0) {
Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
"inflate: literal '%c'\n" :
"inflate: literal 0x%02x\n", here.val));
PUP(out) = (unsigned char)(here.val);
}
else if (op & 16) {
len = (unsigned)(here.val);
op &= 15;
if (op) {
if (bits < op) {
hold += (unsigned long)(PUP(in)) << bits;
bits += 8;
}
len += (unsigned)hold & ((1U << op) - 1);
hold >>= op;
bits -= op;
}
Tracevv((stderr, "inflate: length %u\n", len));
if (bits < 15) {
hold += (unsigned long)(PUP(in)) << bits;
bits += 8;
hold += (unsigned long)(PUP(in)) << bits;
bits += 8;
}
here = dcode[hold & dmask];
dodist:
op = (unsigned)(here.bits);
hold >>= op;
bits -= op;
op = (unsigned)(here.op);
if (op & 16) {
dist = (unsigned)(here.val);
op &= 15;
if (bits < op) {
hold += (unsigned long)(PUP(in)) << bits;
bits += 8;
if (bits < op) {
hold += (unsigned long)(PUP(in)) << bits;
bits += 8;
}
}
dist += (unsigned)hold & ((1U << op) - 1);
#ifdef INFLATE_STRICT
if (dist > dmax) {
strm->msg = (char *)"invalid distance too far back";
state->mode = BAD;
break;
}
#endif
hold >>= op;
bits -= op;
Tracevv((stderr, "inflate: distance %u\n", dist));
op = (unsigned)(out - beg);
if (dist > op) {
op = dist - op;
if (op > whave) {
if (state->sane) {
strm->msg =
(char *)"invalid distance too far back";
state->mode = BAD;
break;
}
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
if (len <= op - whave) {
do {
PUP(out) = 0;
} while (--len);
continue;
}
len -= op - whave;
do {
PUP(out) = 0;
} while (--op > whave);
if (op == 0) {
from = out - dist;
do {
PUP(out) = PUP(from);
} while (--len);
continue;
}
#endif
}
from = window - OFF;
if (wnext == 0) {
from += wsize - op;
if (op < len) {
len -= op;
do {
PUP(out) = PUP(from);
} while (--op);
from = out - dist;
}
}
else if (wnext < op) {
from += wsize + wnext - op;
op -= wnext;
if (op < len) {
len -= op;
do {
PUP(out) = PUP(from);
} while (--op);
from = window - OFF;
if (wnext < len) {
op = wnext;
len -= op;
do {
PUP(out) = PUP(from);
} while (--op);
from = out - dist;
}
}
}
else {
from += wnext - op;
if (op < len) {
len -= op;
do {
PUP(out) = PUP(from);
} while (--op);
from = out - dist;
}
}
while (len > 2) {
PUP(out) = PUP(from);
PUP(out) = PUP(from);
PUP(out) = PUP(from);
len -= 3;
}
if (len) {
PUP(out) = PUP(from);
if (len > 1)
PUP(out) = PUP(from);
}
}
else {
from = out - dist;
do {
PUP(out) = PUP(from);
PUP(out) = PUP(from);
PUP(out) = PUP(from);
len -= 3;
} while (len > 2);
if (len) {
PUP(out) = PUP(from);
if (len > 1)
PUP(out) = PUP(from);
}
}
}
else if ((op & 64) == 0) {
here = dcode[here.val + (hold & ((1U << op) - 1))];
goto dodist;
}
else {
strm->msg = (char *)"invalid distance code";
state->mode = BAD;
break;
}
}
else if ((op & 64) == 0) {
here = lcode[here.val + (hold & ((1U << op) - 1))];
goto dolen;
}
else if (op & 32) {
Tracevv((stderr, "inflate: end of block\n"));
state->mode = TYPE;
break;
}
else {
strm->msg = (char *)"invalid literal/length code";
state->mode = BAD;
break;
}
} while (in < last && out < end);
len = bits >> 3;
in -= len;
bits -= len << 3;
hold &= (1U << bits) - 1;
strm->next_in = in + OFF;
strm->next_out = out + OFF;
strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
strm->avail_out = (unsigned)(out < end ?
257 + (end - out) : 257 - (out - end));
state->hold = hold;
state->bits = bits;
return;
}
#endif