INLINE USHORT decode_p(void){
USHORT i, j, m;
j = pt_table[GETBITS(8)];
if (j < np) {
DROPBITS(pt_len[j]);
} else {
DROPBITS(8);
i = GETBITS(16);
m = 0x8000;
do {
if (i & m) j = right[j];
else j = left [j];
m >>= 1;
} while (j >= np);
DROPBITS(pt_len[j] - 8);
}
if (j != np-1) {
if (j > 0) {
j = (USHORT)(GETBITS(i=(USHORT)(j-1)) | (1U << (j-1)));
DROPBITS(i);
}
lastlen=j;
}
return lastlen;
}
INLINE USHORT DecodePosition(void){
USHORT i, j, c;
i = GETBITS(8); DROPBITS(8);
c = (USHORT) (d_code[i] << 8);
j = d_len[i];
i = (USHORT) (((i << j) | GETBITS(j)) & 0xff); DROPBITS(j);
return (USHORT) (c | i) ;
}
INLINE USHORT decode_c(void){
USHORT i, j, m;
j = c_table[GETBITS(12)];
if (j < N1) {
DROPBITS(c_len[j]);
} else {
DROPBITS(12);
i = GETBITS(16);
m = 0x8000;
do {
if (i & m) j = right[j];
else j = left [j];
m >>= 1;
} while (j >= N1);
DROPBITS(c_len[j] - 12);
}
return j;
}
static USHORT read_tree_p(void){
USHORT i,n;
n = GETBITS(5);
DROPBITS(5);
if (n>0){
for (i=0; i<n; i++) {
pt_len[i] = (UCHAR)GETBITS(4);
DROPBITS(4);
}
for (i=n; i<np; i++) pt_len[i] = 0;
if (make_table(np,pt_len,8,pt_table)) return 1;
} else {
n = GETBITS(5);
DROPBITS(5);
for (i=0; i<np; i++) pt_len[i] = 0;
for (i=0; i<256; i++) pt_table[i] = n;
}
return 0;
}
static USHORT read_tree_c(void){
USHORT i,n;
n = GETBITS(9);
DROPBITS(9);
if (n>0){
for (i=0; i<n; i++) {
c_len[i] = (UCHAR)GETBITS(5);
DROPBITS(5);
}
for (i=n; i<510; i++) c_len[i] = 0;
if (make_table(510,c_len,12,c_table)) return 1;
} else {
n = GETBITS(9);
DROPBITS(9);
for (i=0; i<510; i++) c_len[i] = 0;
for (i=0; i<4096; i++) c_table[i] = n;
}
return 0;
}
USHORT Unpack_QUICK(UCHAR *in, UCHAR *out, USHORT origsize){
USHORT i, j;
UCHAR *outend;
initbitbuf(in);
outend = out+origsize;
while (out < outend) {
if (GETBITS(1)!=0) {
DROPBITS(1);
*out++ = text[quick_text_loc++ & QBITMASK] = (UCHAR)GETBITS(8); DROPBITS(8);
} else {
DROPBITS(1);
j = (USHORT) (GETBITS(2)+2); DROPBITS(2);
i = (USHORT) (quick_text_loc - GETBITS(8) - 1); DROPBITS(8);
while(j--) {
*out++ = text[quick_text_loc++ & QBITMASK] = text[i++ & QBITMASK];
}
}
}
quick_text_loc = (USHORT)((quick_text_loc+5) & QBITMASK);
return 0;
}
INLINE USHORT DecodeChar(void){
USHORT c;
c = son[R];
/* travel from root to leaf, */
/* choosing the smaller child node (son[]) if the read bit is 0, */
/* the bigger (son[]+1} if 1 */
while (c < T) {
c = son[c + GETBITS(1)];
DROPBITS(1);
}
c -= T;
update(c);
return c;
}
/*
Decode literal, length, and distance codes and write out the resulting
literal and match bytes until either not enough input or output is
available, an end-of-block is encountered, or a data error is encountered.
When large enough input and output buffers are supplied to inflate(), for
example, a 16K input buffer and a 64K output buffer, more than 95% of the
inflate execution time is spent in this routine.
Entry assumptions:
state->mode == LEN
strm->avail_in >= 6
strm->avail_out >= 258
start >= strm->avail_out
state->bits < 8
On return, state->mode is one of:
LEN -- ran out of enough output space or enough available input
TYPE -- reached end of block code, inflate() to interpret next block
BAD -- error in block data
Notes:
- The maximum input bits used by a length/distance pair is 15 bits for the
length code, 5 bits for the length extra, 15 bits for the distance code,
and 13 bits for the distance extra. This totals 48 bits, or six bytes.
Therefore if strm->avail_in >= 6, then there is enough input to avoid
checking for available input while decoding.
- The maximum bytes that a single length/distance pair can output is 258
bytes, which is the maximum length that can be coded. inflate_fast()
requires strm->avail_out >= 258 for each loop to avoid checking for
output space.
*/
void ZLIB_INTERNAL inflate_fast(z_stream *strm, unsigned long start) {
/* start: inflate()'s starting value for strm->avail_out */
struct inflate_state *state;
const unsigned char *in; /* local strm->next_in */
const unsigned char *last; /* have enough input while in < last */
unsigned char *out; /* local strm->next_out */
unsigned char *beg; /* inflate()'s initial strm->next_out */
unsigned char *end; /* while out < end, enough space available */
#ifdef INFLATE_STRICT
unsigned dmax; /* maximum distance from zlib header */
#endif
unsigned wsize; /* window size or zero if not using window */
unsigned whave; /* valid bytes in the window */
unsigned wnext; /* window write index */
unsigned char *window; /* allocated sliding window, if wsize != 0 */
uint32_t hold; /* local strm->hold */
unsigned bits; /* local strm->bits */
code const *lcode; /* local strm->lencode */
code const *dcode; /* local strm->distcode */
unsigned lmask; /* mask for first level of length codes */
unsigned dmask; /* mask for first level of distance codes */
code here; /* retrieved table entry */
unsigned op; /* code bits, operation, extra bits, or */
/* window position, window bytes to copy */
unsigned len; /* match length, unused bytes */
unsigned dist; /* match distance */
unsigned char *from; /* where to copy match from */
/* copy state to local variables */
state = (struct inflate_state *)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;
/* decode literals and length/distances until end-of-block or not enough
input data or output space */
do {
if (bits < 15) {
hold += (PUP(in) << bits);
bits += 8;
hold += (PUP(in) << bits);
bits += 8;
}
here = lcode[hold & lmask];
dolen:
DROPBITS(here.bits);
op = here.op;
if (op == 0) { /* literal */
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) { /* length base */
len = here.val;
op &= 15; /* number of extra bits */
if (op) {
if (bits < op) {
hold += (PUP(in) << bits);
bits += 8;
}
len += BITS(op);
DROPBITS(op);
}
Tracevv((stderr, "inflate: length %u\n", len));
if (bits < 15) {
hold += (PUP(in) << bits);
bits += 8;
hold += (PUP(in) << bits);
bits += 8;
}
here = dcode[hold & dmask];
dodist:
DROPBITS(here.bits);
op = here.op;
if (op & 16) { /* distance base */
dist = here.val;
op &= 15; /* number of extra bits */
if (bits < op) {
hold += (PUP(in) << bits);
bits += 8;
if (bits < op) {
hold += (PUP(in) << bits);
bits += 8;
}
}
dist += BITS(op);
#ifdef INFLATE_STRICT
if (dist > dmax) {
strm->msg = (char *)"invalid distance too far back";
state->mode = BAD;
break;
}
#endif
DROPBITS(op);
Tracevv((stderr, "inflate: distance %u\n", dist));
op = (unsigned)(out - beg); /* max distance in output */
if (dist > op) { /* see if copy from window */
op = dist - op; /* distance back in window */
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) { /* very common case */
from += wsize - op;
if (op < len) { /* some from window */
len -= op;
do {
PUP(out) = PUP(from);
} while (--op);
from = out - dist; /* rest from output */
}
} else if (wnext < op) { /* wrap around window */
from += wsize + wnext - op;
op -= wnext;
if (op < len) { /* some from end of window */
len -= op;
do {
PUP(out) = PUP(from);
} while (--op);
from = window - OFF;
if (wnext < len) { /* some from start of window */
op = wnext;
len -= op;
do {
PUP(out) = PUP(from);
} while (--op);
from = out - dist; /* rest from output */
}
}
} else { /* contiguous in window */
from += wnext - op;
if (op < len) { /* some from window */
len -= op;
do {
PUP(out) = PUP(from);
} while (--op);
from = out - dist; /* rest from output */
}
}
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; /* copy direct from output */
do { /* minimum length is three */
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) { /* 2nd level distance code */
here = dcode[here.val + BITS(op)];
goto dodist;
} else {
strm->msg = (char *)"invalid distance code";
state->mode = BAD;
break;
}
} else if ((op & 64) == 0) { /* 2nd level length code */
here = lcode[here.val + BITS(op)];
goto dolen;
} else if (op & 32) { /* end-of-block */
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);
/* return unused bytes (on entry, bits < 8, so in won't go too far back) */
len = bits >> 3;
in -= len;
bits -= len << 3;
hold &= (1U << bits) - 1;
/* update state and return */
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;
}
