diff options
Diffstat (limited to 'Minecraft.Client/Common/zlib/inffast.c')
| -rw-r--r-- | Minecraft.Client/Common/zlib/inffast.c | 661 |
1 files changed, 321 insertions, 340 deletions
diff --git a/Minecraft.Client/Common/zlib/inffast.c b/Minecraft.Client/Common/zlib/inffast.c index bda59ceb..89cce1af 100644 --- a/Minecraft.Client/Common/zlib/inffast.c +++ b/Minecraft.Client/Common/zlib/inffast.c @@ -1,340 +1,321 @@ -/* inffast.c -- fast decoding - * Copyright (C) 1995-2008, 2010, 2013 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" - -#ifndef ASMINF - -/* Allow machine dependent optimization for post-increment or pre-increment. - Based on testing to date, - Pre-increment preferred for: - - PowerPC G3 (Adler) - - MIPS R5000 (Randers-Pehrson) - Post-increment preferred for: - - none - No measurable difference: - - Pentium III (Anderson) - - M68060 (Nikl) - */ -#ifdef POSTINC -# define OFF 0 -# define PUP(a) *(a)++ -#else -# define OFF 1 -# define PUP(a) *++(a) -#endif - -/* - 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 - 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 += (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) { /* 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 = (unsigned)(here.val); - op &= 15; /* number of extra bits */ - 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) { /* distance base */ - dist = (unsigned)(here.val); - op &= 15; /* number of extra bits */ - 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); /* 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 + (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 + 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; -} - -/* - 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 */ +/* inffast.c -- fast decoding
+ * Copyright (C) 1995-2026 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(z_streamp strm, unsigned start) {
+ 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 const *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 = (z_const 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 = (z_const 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 = (z_const 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 = (z_const 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 */
|
