diff options
Diffstat (limited to 'lib/zlib_inflate')
-rw-r--r-- | lib/zlib_inflate/Makefile | 4 | ||||
-rw-r--r-- | lib/zlib_inflate/infblock.c | 365 | ||||
-rw-r--r-- | lib/zlib_inflate/infblock.h | 48 | ||||
-rw-r--r-- | lib/zlib_inflate/infcodes.c | 202 | ||||
-rw-r--r-- | lib/zlib_inflate/infcodes.h | 33 | ||||
-rw-r--r-- | lib/zlib_inflate/inffast.c | 462 | ||||
-rw-r--r-- | lib/zlib_inflate/inffast.h | 12 | ||||
-rw-r--r-- | lib/zlib_inflate/inffixed.h | 94 | ||||
-rw-r--r-- | lib/zlib_inflate/inflate.c | 1086 | ||||
-rw-r--r-- | lib/zlib_inflate/inflate.h | 107 | ||||
-rw-r--r-- | lib/zlib_inflate/inflate_syms.c | 3 | ||||
-rw-r--r-- | lib/zlib_inflate/inflate_sync.c | 152 | ||||
-rw-r--r-- | lib/zlib_inflate/inftrees.c | 683 | ||||
-rw-r--r-- | lib/zlib_inflate/inftrees.h | 99 | ||||
-rw-r--r-- | lib/zlib_inflate/infutil.c | 88 | ||||
-rw-r--r-- | lib/zlib_inflate/infutil.h | 176 |
16 files changed, 1729 insertions, 1885 deletions
diff --git a/lib/zlib_inflate/Makefile b/lib/zlib_inflate/Makefile index 221c139e0df..bf065482fa6 100644 --- a/lib/zlib_inflate/Makefile +++ b/lib/zlib_inflate/Makefile @@ -15,5 +15,5 @@ obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate.o -zlib_inflate-objs := infblock.o infcodes.o inffast.o inflate.o \ - inflate_sync.o inftrees.o infutil.o inflate_syms.o +zlib_inflate-objs := inffast.o inflate.o \ + inftrees.o inflate_syms.o diff --git a/lib/zlib_inflate/infblock.c b/lib/zlib_inflate/infblock.c deleted file mode 100644 index c16cdeff51a..00000000000 --- a/lib/zlib_inflate/infblock.c +++ /dev/null @@ -1,365 +0,0 @@ -/* infblock.c -- interpret and process block types to last block - * Copyright (C) 1995-1998 Mark Adler - * For conditions of distribution and use, see copyright notice in zlib.h - */ - -#include <linux/zutil.h> -#include "infblock.h" -#include "inftrees.h" -#include "infcodes.h" -#include "infutil.h" - -struct inflate_codes_state; - -/* simplify the use of the inflate_huft type with some defines */ -#define exop word.what.Exop -#define bits word.what.Bits - -/* Table for deflate from PKZIP's appnote.txt. */ -static const uInt border[] = { /* Order of the bit length code lengths */ - 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; - -/* - Notes beyond the 1.93a appnote.txt: - - 1. Distance pointers never point before the beginning of the output - stream. - 2. Distance pointers can point back across blocks, up to 32k away. - 3. There is an implied maximum of 7 bits for the bit length table and - 15 bits for the actual data. - 4. If only one code exists, then it is encoded using one bit. (Zero - would be more efficient, but perhaps a little confusing.) If two - codes exist, they are coded using one bit each (0 and 1). - 5. There is no way of sending zero distance codes--a dummy must be - sent if there are none. (History: a pre 2.0 version of PKZIP would - store blocks with no distance codes, but this was discovered to be - too harsh a criterion.) Valid only for 1.93a. 2.04c does allow - zero distance codes, which is sent as one code of zero bits in - length. - 6. There are up to 286 literal/length codes. Code 256 represents the - end-of-block. Note however that the static length tree defines - 288 codes just to fill out the Huffman codes. Codes 286 and 287 - cannot be used though, since there is no length base or extra bits - defined for them. Similarily, there are up to 30 distance codes. - However, static trees define 32 codes (all 5 bits) to fill out the - Huffman codes, but the last two had better not show up in the data. - 7. Unzip can check dynamic Huffman blocks for complete code sets. - The exception is that a single code would not be complete (see #4). - 8. The five bits following the block type is really the number of - literal codes sent minus 257. - 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits - (1+6+6). Therefore, to output three times the length, you output - three codes (1+1+1), whereas to output four times the same length, - you only need two codes (1+3). Hmm. - 10. In the tree reconstruction algorithm, Code = Code + Increment - only if BitLength(i) is not zero. (Pretty obvious.) - 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) - 12. Note: length code 284 can represent 227-258, but length code 285 - really is 258. The last length deserves its own, short code - since it gets used a lot in very redundant files. The length - 258 is special since 258 - 3 (the min match length) is 255. - 13. The literal/length and distance code bit lengths are read as a - single stream of lengths. It is possible (and advantageous) for - a repeat code (16, 17, or 18) to go across the boundary between - the two sets of lengths. - */ - - -void zlib_inflate_blocks_reset( - inflate_blocks_statef *s, - z_streamp z, - uLong *c -) -{ - if (c != NULL) - *c = s->check; - if (s->mode == CODES) - zlib_inflate_codes_free(s->sub.decode.codes, z); - s->mode = TYPE; - s->bitk = 0; - s->bitb = 0; - s->read = s->write = s->window; - if (s->checkfn != NULL) - z->adler = s->check = (*s->checkfn)(0L, NULL, 0); -} - -inflate_blocks_statef *zlib_inflate_blocks_new( - z_streamp z, - check_func c, - uInt w -) -{ - inflate_blocks_statef *s; - - s = &WS(z)->working_blocks_state; - s->hufts = WS(z)->working_hufts; - s->window = WS(z)->working_window; - s->end = s->window + w; - s->checkfn = c; - s->mode = TYPE; - zlib_inflate_blocks_reset(s, z, NULL); - return s; -} - - -int zlib_inflate_blocks( - inflate_blocks_statef *s, - z_streamp z, - int r -) -{ - uInt t; /* temporary storage */ - uLong b; /* bit buffer */ - uInt k; /* bits in bit buffer */ - Byte *p; /* input data pointer */ - uInt n; /* bytes available there */ - Byte *q; /* output window write pointer */ - uInt m; /* bytes to end of window or read pointer */ - - /* copy input/output information to locals (UPDATE macro restores) */ - LOAD - - /* process input based on current state */ - while (1) switch (s->mode) - { - case TYPE: - NEEDBITS(3) - t = (uInt)b & 7; - s->last = t & 1; - switch (t >> 1) - { - case 0: /* stored */ - DUMPBITS(3) - t = k & 7; /* go to byte boundary */ - DUMPBITS(t) - s->mode = LENS; /* get length of stored block */ - break; - case 1: /* fixed */ - { - uInt bl, bd; - inflate_huft *tl, *td; - - zlib_inflate_trees_fixed(&bl, &bd, &tl, &td, s->hufts, z); - s->sub.decode.codes = zlib_inflate_codes_new(bl, bd, tl, td, z); - if (s->sub.decode.codes == NULL) - { - r = Z_MEM_ERROR; - LEAVE - } - } - DUMPBITS(3) - s->mode = CODES; - break; - case 2: /* dynamic */ - DUMPBITS(3) - s->mode = TABLE; - break; - case 3: /* illegal */ - DUMPBITS(3) - s->mode = B_BAD; - z->msg = (char*)"invalid block type"; - r = Z_DATA_ERROR; - LEAVE - } - break; - case LENS: - NEEDBITS(32) - if ((((~b) >> 16) & 0xffff) != (b & 0xffff)) - { - s->mode = B_BAD; - z->msg = (char*)"invalid stored block lengths"; - r = Z_DATA_ERROR; - LEAVE - } - s->sub.left = (uInt)b & 0xffff; - b = k = 0; /* dump bits */ - s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE); - break; - case STORED: - if (n == 0) - LEAVE - NEEDOUT - t = s->sub.left; - if (t > n) t = n; - if (t > m) t = m; - memcpy(q, p, t); - p += t; n -= t; - q += t; m -= t; - if ((s->sub.left -= t) != 0) - break; - s->mode = s->last ? DRY : TYPE; - break; - case TABLE: - NEEDBITS(14) - s->sub.trees.table = t = (uInt)b & 0x3fff; -#ifndef PKZIP_BUG_WORKAROUND - if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) - { - s->mode = B_BAD; - z->msg = (char*)"too many length or distance symbols"; - r = Z_DATA_ERROR; - LEAVE - } -#endif - { - s->sub.trees.blens = WS(z)->working_blens; - } - DUMPBITS(14) - s->sub.trees.index = 0; - s->mode = BTREE; - case BTREE: - while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) - { - NEEDBITS(3) - s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; - DUMPBITS(3) - } - while (s->sub.trees.index < 19) - s->sub.trees.blens[border[s->sub.trees.index++]] = 0; - s->sub.trees.bb = 7; - t = zlib_inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, - &s->sub.trees.tb, s->hufts, z); - if (t != Z_OK) - { - r = t; - if (r == Z_DATA_ERROR) - s->mode = B_BAD; - LEAVE - } - s->sub.trees.index = 0; - s->mode = DTREE; - case DTREE: - while (t = s->sub.trees.table, - s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) - { - inflate_huft *h; - uInt i, j, c; - - t = s->sub.trees.bb; - NEEDBITS(t) - h = s->sub.trees.tb + ((uInt)b & zlib_inflate_mask[t]); - t = h->bits; - c = h->base; - if (c < 16) - { - DUMPBITS(t) - s->sub.trees.blens[s->sub.trees.index++] = c; - } - else /* c == 16..18 */ - { - i = c == 18 ? 7 : c - 14; - j = c == 18 ? 11 : 3; - NEEDBITS(t + i) - DUMPBITS(t) - j += (uInt)b & zlib_inflate_mask[i]; - DUMPBITS(i) - i = s->sub.trees.index; - t = s->sub.trees.table; - if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || - (c == 16 && i < 1)) - { - s->mode = B_BAD; - z->msg = (char*)"invalid bit length repeat"; - r = Z_DATA_ERROR; - LEAVE - } - c = c == 16 ? s->sub.trees.blens[i - 1] : 0; - do { - s->sub.trees.blens[i++] = c; - } while (--j); - s->sub.trees.index = i; - } - } - s->sub.trees.tb = NULL; - { - uInt bl, bd; - inflate_huft *tl, *td; - inflate_codes_statef *c; - - bl = 9; /* must be <= 9 for lookahead assumptions */ - bd = 6; /* must be <= 9 for lookahead assumptions */ - t = s->sub.trees.table; - t = zlib_inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), - s->sub.trees.blens, &bl, &bd, &tl, &td, - s->hufts, z); - if (t != Z_OK) - { - if (t == (uInt)Z_DATA_ERROR) - s->mode = B_BAD; - r = t; - LEAVE - } - if ((c = zlib_inflate_codes_new(bl, bd, tl, td, z)) == NULL) - { - r = Z_MEM_ERROR; - LEAVE - } - s->sub.decode.codes = c; - } - s->mode = CODES; - case CODES: - UPDATE - if ((r = zlib_inflate_codes(s, z, r)) != Z_STREAM_END) - return zlib_inflate_flush(s, z, r); - r = Z_OK; - zlib_inflate_codes_free(s->sub.decode.codes, z); - LOAD - if (!s->last) - { - s->mode = TYPE; - break; - } - s->mode = DRY; - case DRY: - FLUSH - if (s->read != s->write) - LEAVE - s->mode = B_DONE; - case B_DONE: - r = Z_STREAM_END; - LEAVE - case B_BAD: - r = Z_DATA_ERROR; - LEAVE - default: - r = Z_STREAM_ERROR; - LEAVE - } -} - - -int zlib_inflate_blocks_free( - inflate_blocks_statef *s, - z_streamp z -) -{ - zlib_inflate_blocks_reset(s, z, NULL); - return Z_OK; -} - - -#if 0 -void zlib_inflate_set_dictionary( - inflate_blocks_statef *s, - const Byte *d, - uInt n -) -{ - memcpy(s->window, d, n); - s->read = s->write = s->window + n; -} -#endif /* 0 */ - - -/* Returns true if inflate is currently at the end of a block generated - * by Z_SYNC_FLUSH or Z_FULL_FLUSH. - * IN assertion: s != NULL - */ -#if 0 -int zlib_inflate_blocks_sync_point( - inflate_blocks_statef *s -) -{ - return s->mode == LENS; -} -#endif /* 0 */ diff --git a/lib/zlib_inflate/infblock.h b/lib/zlib_inflate/infblock.h deleted file mode 100644 index ceee60b5107..00000000000 --- a/lib/zlib_inflate/infblock.h +++ /dev/null @@ -1,48 +0,0 @@ -/* infblock.h -- header to use infblock.c - * Copyright (C) 1995-1998 Mark Adler - * For conditions of distribution and use, see copyright notice in zlib.h - */ - -/* WARNING: this file should *not* be used by applications. It is - part of the implementation of the compression library and is - subject to change. Applications should only use zlib.h. - */ - -#ifndef _INFBLOCK_H -#define _INFBLOCK_H - -struct inflate_blocks_state; -typedef struct inflate_blocks_state inflate_blocks_statef; - -extern inflate_blocks_statef * zlib_inflate_blocks_new ( - z_streamp z, - check_func c, /* check function */ - uInt w); /* window size */ - -extern int zlib_inflate_blocks ( - inflate_blocks_statef *, - z_streamp , - int); /* initial return code */ - -extern void zlib_inflate_blocks_reset ( - inflate_blocks_statef *, - z_streamp , - uLong *); /* check value on output */ - -extern int zlib_inflate_blocks_free ( - inflate_blocks_statef *, - z_streamp); - -#if 0 -extern void zlib_inflate_set_dictionary ( - inflate_blocks_statef *s, - const Byte *d, /* dictionary */ - uInt n); /* dictionary length */ -#endif /* 0 */ - -#if 0 -extern int zlib_inflate_blocks_sync_point ( - inflate_blocks_statef *s); -#endif /* 0 */ - -#endif /* _INFBLOCK_H */ diff --git a/lib/zlib_inflate/infcodes.c b/lib/zlib_inflate/infcodes.c deleted file mode 100644 index 07cd7591cbb..00000000000 --- a/lib/zlib_inflate/infcodes.c +++ /dev/null @@ -1,202 +0,0 @@ -/* 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( - uInt bl, - uInt 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( - 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 */ - Byte *p; /* input data pointer */ - uInt n; /* bytes available there */ - Byte *q; /* output window write pointer */ - uInt m; /* bytes to end of window or read pointer */ - Byte *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 */ - f = q - c->sub.copy.dist; - while (f < s->window) /* modulo window size-"while" instead */ - f += s->end - s->window; /* of "if" handles invalid distances */ - 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( - inflate_codes_statef *c, - z_streamp z -) -{ -} diff --git a/lib/zlib_inflate/infcodes.h b/lib/zlib_inflate/infcodes.h deleted file mode 100644 index 5cff417523b..00000000000 --- a/lib/zlib_inflate/infcodes.h +++ /dev/null @@ -1,33 +0,0 @@ -/* infcodes.h -- header to use infcodes.c - * Copyright (C) 1995-1998 Mark Adler - * For conditions of distribution and use, see copyright notice in zlib.h - */ - -/* WARNING: this file should *not* be used by applications. It is - part of the implementation of the compression library and is - subject to change. Applications should only use zlib.h. - */ - -#ifndef _INFCODES_H -#define _INFCODES_H - -#include "infblock.h" - -struct inflate_codes_state; -typedef struct inflate_codes_state inflate_codes_statef; - -extern inflate_codes_statef *zlib_inflate_codes_new ( - uInt, uInt, - inflate_huft *, inflate_huft *, - z_streamp ); - -extern int zlib_inflate_codes ( - inflate_blocks_statef *, - z_streamp , - int); - -extern void zlib_inflate_codes_free ( - inflate_codes_statef *, - z_streamp ); - -#endif /* _INFCODES_H */ diff --git a/lib/zlib_inflate/inffast.c b/lib/zlib_inflate/inffast.c index 0bd7623fc85..02a16eacb72 100644 --- a/lib/zlib_inflate/inffast.c +++ b/lib/zlib_inflate/inffast.c @@ -1,176 +1,312 @@ -/* inffast.c -- process literals and length/distance pairs fast - * Copyright (C) 1995-1998 Mark Adler - * For conditions of distribution and use, see copyright notice in zlib.h +/* inffast.c -- fast decoding + * Copyright (C) 1995-2004 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 "inflate.h" #include "inffast.h" -struct inflate_codes_state; - -/* simplify the use of the inflate_huft type with some defines */ -#define exop word.what.Exop -#define bits word.what.Bits - -/* macros for bit input with no checking and for returning unused bytes */ -#define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} -#define UNGRAB {c=z->avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;} - -/* Called with number of bytes left to write in window at least 258 - (the maximum string length) and number of input bytes available - at least ten. The ten bytes are six bytes for the longest length/ - distance pair plus four bytes for overloading the bit buffer. */ - -int zlib_inflate_fast( - uInt bl, - uInt bd, - inflate_huft *tl, - inflate_huft *td, /* need separate declaration for Borland C++ */ - inflate_blocks_statef *s, - z_streamp z -) +#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 inflate_fast(strm, start) +z_streamp strm; +unsigned start; /* inflate()'s starting value for strm->avail_out */ { - inflate_huft *t; /* temporary pointer */ - uInt e; /* extra bits or operation */ - uLong b; /* bit buffer */ - uInt k; /* bits in bit buffer */ - Byte *p; /* input data pointer */ - uInt n; /* bytes available there */ - Byte *q; /* output window write pointer */ - uInt m; /* bytes to end of window or read pointer */ - uInt ml; /* mask for literal/length tree */ - uInt md; /* mask for distance tree */ - uInt c; /* bytes to copy */ - uInt d; /* distance back to copy from */ - Byte *r; /* copy source pointer */ - - /* load input, output, bit values */ - LOAD - - /* initialize masks */ - ml = zlib_inflate_mask[bl]; - md = zlib_inflate_mask[bd]; - - /* do until not enough input or output space for fast loop */ - do { /* assume called with m >= 258 && n >= 10 */ - /* get literal/length code */ - GRABBITS(20) /* max bits for literal/length code */ - if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) - { - DUMPBITS(t->bits) - *q++ = (Byte)t->base; - m--; - continue; - } + struct inflate_state *state; + unsigned char *in; /* local strm->next_in */ + unsigned char *last; /* while in < last, enough input available */ + 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 write; /* window write index */ + unsigned char *window; /* allocated sliding window, if wsize != 0 */ + unsigned long 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 this; /* 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; + write = state->write; + 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 { - DUMPBITS(t->bits) - if (e & 16) - { - /* get extra bits for length */ - e &= 15; - c = t->base + ((uInt)b & zlib_inflate_mask[e]); - DUMPBITS(e) - - /* decode distance base of block to copy */ - GRABBITS(15); /* max bits for distance code */ - e = (t = td + ((uInt)b & md))->exop; - do { - DUMPBITS(t->bits) - if (e & 16) - { - /* get extra bits to add to distance base */ - e &= 15; - GRABBITS(e) /* get extra bits (up to 13) */ - d = t->base + ((uInt)b & zlib_inflate_mask[e]); - DUMPBITS(e) - - /* do the copy */ - m -= c; - r = q - d; - if (r < s->window) /* wrap if needed */ - { - do { - r += s->end - s->window; /* force pointer in window */ - } while (r < s->window); /* covers invalid distances */ - e = s->end - r; - if (c > e) - { - c -= e; /* wrapped copy */ - do { - *q++ = *r++; - } while (--e); - r = s->window; - do { - *q++ = *r++; - } while (--c); - } - else /* normal copy */ - { - *q++ = *r++; c--; - *q++ = *r++; c--; - do { - *q++ = *r++; - } while (--c); - } + if (bits < 15) { + hold += (unsigned long)(PUP(in)) << bits; + bits += 8; + hold += (unsigned long)(PUP(in)) << bits; + bits += 8; + } + this = lcode[hold & lmask]; + dolen: + op = (unsigned)(this.bits); + hold >>= op; + bits -= op; + op = (unsigned)(this.op); + if (op == 0) { /* literal */ + PUP(out) = (unsigned char)(this.val); + } + else if (op & 16) { /* length base */ + len = (unsigned)(this.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; + } + if (bits < 15) { + hold += (unsigned long)(PUP(in)) << bits; + bits += 8; + hold += (unsigned long)(PUP(in)) << bits; + bits += 8; + } + this = dcode[hold & dmask]; + dodist: + op = (unsigned)(this.bits); + hold >>= op; + bits -= op; + op = (unsigned)(this.op); + if (op & 16) { /* distance base */ + dist = (unsigned)(this.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 = |