#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 void ZLIB_INTERNAL inflate_fast(strm, start) z_streamp strm; unsigned start; { struct inflate_state FAR *state; z_const unsigned char FAR *in; z_const 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; 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; 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) { 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) { len = (unsigned)(here.val); op &= 15; 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) { dist = (unsigned)(here.val); op &= 15; 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); 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 { *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) { from += wsize - op; if (op < len) { len -= op; do { *out++ = *from++; } while (--op); from = out - dist; } } else if (wnext < op) { from += wsize + wnext - op; op -= wnext; if (op < len) { len -= op; do { *out++ = *from++; } while (--op); from = window; if (wnext < len) { op = wnext; len -= op; do { *out++ = *from++; } while (--op); from = out - dist; } } } else { from += wnext - op; if (op < len) { len -= op; do { *out++ = *from++; } while (--op); from = out - dist; } } while (len > 2) { *out++ = *from++; *out++ = *from++; *out++ = *from++; len -= 3; } if (len) { *out++ = *from++; if (len > 1) *out++ = *from++; } } else { from = out - dist; do { *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) { 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; 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; } #endif