| /* infcodes.c -- process literals and length/distance pairs |
| * Copyright (C) 1995-1998 Mark Adler |
| * For conditions of distribution and use, see copyright notice in zlib.h |
| */ |
| |
| #include <linux/zutil.h> |
| #include "inftrees.h" |
| #include "infblock.h" |
| #include "infcodes.h" |
| #include "infutil.h" |
| #include "inffast.h" |
| |
| /* simplify the use of the inflate_huft type with some defines */ |
| #define exop word.what.Exop |
| #define bits word.what.Bits |
| |
| inflate_codes_statef *zlib_inflate_codes_new(bl, bd, tl, td, z) |
| uInt bl, bd; |
| inflate_huft *tl; |
| inflate_huft *td; /* need separate declaration for Borland C++ */ |
| z_streamp z; |
| { |
| inflate_codes_statef *c; |
| |
| c = &WS(z)->working_state; |
| { |
| c->mode = START; |
| c->lbits = (Byte)bl; |
| c->dbits = (Byte)bd; |
| c->ltree = tl; |
| c->dtree = td; |
| } |
| return c; |
| } |
| |
| |
| int zlib_inflate_codes(s, z, r) |
| inflate_blocks_statef *s; |
| z_streamp z; |
| int r; |
| { |
| uInt j; /* temporary storage */ |
| inflate_huft *t; /* temporary pointer */ |
| uInt e; /* extra bits or operation */ |
| uLong b; /* bit buffer */ |
| uInt k; /* bits in bit buffer */ |
| Bytef *p; /* input data pointer */ |
| uInt n; /* bytes available there */ |
| Bytef *q; /* output window write pointer */ |
| uInt m; /* bytes to end of window or read pointer */ |
| Bytef *f; /* pointer to copy strings from */ |
| inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ |
| |
| /* copy input/output information to locals (UPDATE macro restores) */ |
| LOAD |
| |
| /* process input and output based on current state */ |
| while (1) switch (c->mode) |
| { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ |
| case START: /* x: set up for LEN */ |
| #ifndef SLOW |
| if (m >= 258 && n >= 10) |
| { |
| UPDATE |
| r = zlib_inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); |
| LOAD |
| if (r != Z_OK) |
| { |
| c->mode = r == Z_STREAM_END ? WASH : BADCODE; |
| break; |
| } |
| } |
| #endif /* !SLOW */ |
| c->sub.code.need = c->lbits; |
| c->sub.code.tree = c->ltree; |
| c->mode = LEN; |
| case LEN: /* i: get length/literal/eob next */ |
| j = c->sub.code.need; |
| NEEDBITS(j) |
| t = c->sub.code.tree + ((uInt)b & zlib_inflate_mask[j]); |
| DUMPBITS(t->bits) |
| e = (uInt)(t->exop); |
| if (e == 0) /* literal */ |
| { |
| c->sub.lit = t->base; |
| c->mode = LIT; |
| break; |
| } |
| if (e & 16) /* length */ |
| { |
| c->sub.copy.get = e & 15; |
| c->len = t->base; |
| c->mode = LENEXT; |
| break; |
| } |
| if ((e & 64) == 0) /* next table */ |
| { |
| c->sub.code.need = e; |
| c->sub.code.tree = t + t->base; |
| break; |
| } |
| if (e & 32) /* end of block */ |
| { |
| c->mode = WASH; |
| break; |
| } |
| c->mode = BADCODE; /* invalid code */ |
| z->msg = (char*)"invalid literal/length code"; |
| r = Z_DATA_ERROR; |
| LEAVE |
| case LENEXT: /* i: getting length extra (have base) */ |
| j = c->sub.copy.get; |
| NEEDBITS(j) |
| c->len += (uInt)b & zlib_inflate_mask[j]; |
| DUMPBITS(j) |
| c->sub.code.need = c->dbits; |
| c->sub.code.tree = c->dtree; |
| c->mode = DIST; |
| case DIST: /* i: get distance next */ |
| j = c->sub.code.need; |
| NEEDBITS(j) |
| t = c->sub.code.tree + ((uInt)b & zlib_inflate_mask[j]); |
| DUMPBITS(t->bits) |
| e = (uInt)(t->exop); |
| if (e & 16) /* distance */ |
| { |
| c->sub.copy.get = e & 15; |
| c->sub.copy.dist = t->base; |
| c->mode = DISTEXT; |
| break; |
| } |
| if ((e & 64) == 0) /* next table */ |
| { |
| c->sub.code.need = e; |
| c->sub.code.tree = t + t->base; |
| break; |
| } |
| c->mode = BADCODE; /* invalid code */ |
| z->msg = (char*)"invalid distance code"; |
| r = Z_DATA_ERROR; |
| LEAVE |
| case DISTEXT: /* i: getting distance extra */ |
| j = c->sub.copy.get; |
| NEEDBITS(j) |
| c->sub.copy.dist += (uInt)b & zlib_inflate_mask[j]; |
| DUMPBITS(j) |
| c->mode = COPY; |
| case COPY: /* o: copying bytes in window, waiting for space */ |
| #ifndef __TURBOC__ /* Turbo C bug for following expression */ |
| f = (uInt)(q - s->window) < c->sub.copy.dist ? |
| s->end - (c->sub.copy.dist - (q - s->window)) : |
| q - c->sub.copy.dist; |
| #else |
| f = q - c->sub.copy.dist; |
| if ((uInt)(q - s->window) < c->sub.copy.dist) |
| f = s->end - (c->sub.copy.dist - (uInt)(q - s->window)); |
| #endif |
| while (c->len) |
| { |
| NEEDOUT |
| OUTBYTE(*f++) |
| if (f == s->end) |
| f = s->window; |
| c->len--; |
| } |
| c->mode = START; |
| break; |
| case LIT: /* o: got literal, waiting for output space */ |
| NEEDOUT |
| OUTBYTE(c->sub.lit) |
| c->mode = START; |
| break; |
| case WASH: /* o: got eob, possibly more output */ |
| if (k > 7) /* return unused byte, if any */ |
| { |
| k -= 8; |
| n++; |
| p--; /* can always return one */ |
| } |
| FLUSH |
| if (s->read != s->write) |
| LEAVE |
| c->mode = END; |
| case END: |
| r = Z_STREAM_END; |
| LEAVE |
| case BADCODE: /* x: got error */ |
| r = Z_DATA_ERROR; |
| LEAVE |
| default: |
| r = Z_STREAM_ERROR; |
| LEAVE |
| } |
| #ifdef NEED_DUMMY_RETURN |
| return Z_STREAM_ERROR; /* Some dumb compilers complain without this */ |
| #endif |
| } |
| |
| |
| void zlib_inflate_codes_free(c, z) |
| inflate_codes_statef *c; |
| z_streamp z; |
| { |
| } |