mirror of
https://github.com/cmclark00/retro-imager.git
synced 2025-05-19 00:15:21 +01:00
Qt/QML edition
This commit is contained in:
Floris Bos
commit
d7b361ba44
2168 changed files with 721948 additions and 0 deletions
323
dependencies/zlib-1.2.11/inffast.c
vendored
Normal file
323
dependencies/zlib-1.2.11/inffast.c
vendored
Normal file
|
|
@ -0,0 +1,323 @@
|
|||
/* inffast.c -- fast decoding
|
||||
* Copyright (C) 1995-2017 Mark Adler
|
||||
* For conditions of distribution and use, see copyright notice in zlib.h
|
||||
*/
|
||||
|
||||
#include "zutil.h"
|
||||
#include "inftrees.h"
|
||||
#include "inflate.h"
|
||||
#include "inffast.h"
|
||||
|
||||
#ifdef ASMINF
|
||||
# pragma message("Assembler code may have bugs -- use at your own risk")
|
||||
#else
|
||||
|
||||
/*
|
||||
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(strm, start)
|
||||
z_streamp strm;
|
||||
unsigned start; /* inflate()'s starting value for strm->avail_out */
|
||||
{
|
||||
struct inflate_state FAR *state;
|
||||
z_const unsigned char FAR *in; /* local strm->next_in */
|
||||
z_const unsigned char FAR *last; /* have enough input while in < last */
|
||||
unsigned char FAR *out; /* local strm->next_out */
|
||||
unsigned char FAR *beg; /* inflate()'s initial strm->next_out */
|
||||
unsigned char FAR *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 FAR *window; /* allocated sliding window, if wsize != 0 */
|
||||
unsigned long hold; /* local strm->hold */
|
||||
unsigned bits; /* local strm->bits */
|
||||
code const FAR *lcode; /* local strm->lencode */
|
||||
code const FAR *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 FAR *from; /* where to copy match from */
|
||||
|
||||
/* copy state to local variables */
|
||||
state = (struct inflate_state FAR *)strm->state;
|
||||
in = strm->next_in;
|
||||
last = in + (strm->avail_in - 5);
|
||||
out = strm->next_out;
|
||||
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 += (unsigned long)(*in++) << bits;
|
||||
bits += 8;
|
||||
hold += (unsigned long)(*in++) << bits;
|
||||
bits += 8;
|
||||
}
|
||||
here = lcode[hold & lmask];
|
||||
dolen:
|
||||
op = (unsigned)(here.bits);
|
||||
hold >>= op;
|
||||
bits -= op;
|
||||
op = (unsigned)(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));
|
||||
*out++ = (unsigned char)(here.val);
|
||||
}
|
||||
else if (op & 16) { /* length base */
|
||||
len = (unsigned)(here.val);
|
||||
op &= 15; /* number of extra bits */
|
||||
if (op) {
|
||||
if (bits < op) {
|
||||
hold += (unsigned long)(*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)(*in++) << bits;
|
||||
bits += 8;
|
||||
hold += (unsigned long)(*in++) << bits;
|
||||
bits += 8;
|
||||
}
|
||||
here = dcode[hold & dmask];
|
||||
dodist:
|
||||
op = (unsigned)(here.bits);
|
||||
hold >>= op;
|
||||
bits -= op;
|
||||
op = (unsigned)(here.op);
|
||||
if (op & 16) { /* distance base */
|
||||
dist = (unsigned)(here.val);
|
||||
op &= 15; /* number of extra bits */
|
||||
if (bits < op) {
|
||||
hold += (unsigned long)(*in++) << bits;
|
||||
bits += 8;
|
||||
if (bits < op) {
|
||||
hold += (unsigned long)(*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); /* 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 {
|
||||
*out++ = 0;
|
||||
} while (--len);
|
||||
continue;
|
||||
}
|
||||
len -= op - whave;
|
||||
do {
|
||||
*out++ = 0;
|
||||
} while (--op > whave);
|
||||
if (op == 0) {
|
||||
from = out - dist;
|
||||
do {
|
||||
*out++ = *from++;
|
||||
} while (--len);
|
||||
continue;
|
||||
}
|
||||
#endif
|
||||
}
|
||||
from = window;
|
||||
if (wnext == 0) { /* very common case */
|
||||
from += wsize - op;
|
||||
if (op < len) { /* some from window */
|
||||
len -= op;
|
||||
do {
|
||||
*out++ = *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 {
|
||||
*out++ = *from++;
|
||||
} while (--op);
|
||||
from = window;
|
||||
if (wnext < len) { /* some from start of window */
|
||||
op = wnext;
|
||||
len -= op;
|
||||
do {
|
||||
*out++ = *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 {
|
||||
*out++ = *from++;
|
||||
} while (--op);
|
||||
from = out - dist; /* rest from output */
|
||||
}
|
||||
}
|
||||
while (len > 2) {
|
||||
*out++ = *from++;
|
||||
*out++ = *from++;
|
||||
*out++ = *from++;
|
||||
len -= 3;
|
||||
}
|
||||
if (len) {
|
||||
*out++ = *from++;
|
||||
if (len > 1)
|
||||
*out++ = *from++;
|
||||
}
|
||||
}
|
||||
else {
|
||||
from = out - dist; /* copy direct from output */
|
||||
do { /* minimum length is three */
|
||||
*out++ = *from++;
|
||||
*out++ = *from++;
|
||||
*out++ = *from++;
|
||||
len -= 3;
|
||||
} while (len > 2);
|
||||
if (len) {
|
||||
*out++ = *from++;
|
||||
if (len > 1)
|
||||
*out++ = *from++;
|
||||
}
|
||||
}
|
||||
}
|
||||
else if ((op & 64) == 0) { /* 2nd level distance code */
|
||||
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) { /* 2nd level length code */
|
||||
here = lcode[here.val + (hold & ((1U << op) - 1))];
|
||||
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;
|
||||
strm->next_out = out;
|
||||
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;
|
||||
}
|
||||
|
||||
/*
|
||||
inflate_fast() speedups that turned out slower (on a PowerPC G3 750CXe):
|
||||
- Using bit fields for code structure
|
||||
- Different op definition to avoid & for extra bits (do & for table bits)
|
||||
- Three separate decoding do-loops for direct, window, and wnext == 0
|
||||
- Special case for distance > 1 copies to do overlapped load and store copy
|
||||
- Explicit branch predictions (based on measured branch probabilities)
|
||||
- Deferring match copy and interspersed it with decoding subsequent codes
|
||||
- Swapping literal/length else
|
||||
- Swapping window/direct else
|
||||
- Larger unrolled copy loops (three is about right)
|
||||
- Moving len -= 3 statement into middle of loop
|
||||
*/
|
||||
|
||||
#endif /* !ASMINF */
|
||||
Loading…
Add table
Add a link
Reference in a new issue