f6bcfd974e
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@7748 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
872 lines
30 KiB
C
872 lines
30 KiB
C
/* explode.c -- put in the public domain by Mark Adler
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version c15, 6 July 1996 */
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/* You can do whatever you like with this source file, though I would
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prefer that if you modify it and redistribute it that you include
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comments to that effect with your name and the date. Thank you.
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History:
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vers date who what
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---- --------- -------------- ------------------------------------
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c1 30 Mar 92 M. Adler explode that uses huft_build from inflate
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(this gives over a 70% speed improvement
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over the original unimplode.c, which
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decoded a bit at a time)
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c2 4 Apr 92 M. Adler fixed bug for file sizes a multiple of 32k.
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c3 10 Apr 92 M. Adler added a little memory tracking if DEBUG
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c4 11 Apr 92 M. Adler added NOMEMCPY do kill use of memcpy()
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c5 21 Apr 92 M. Adler added the WSIZE #define to allow reducing
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the 32K window size for specialized
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applications.
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c6 31 May 92 M. Adler added typecasts to eliminate some warnings
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c7 27 Jun 92 G. Roelofs added more typecasts.
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c8 17 Oct 92 G. Roelofs changed ULONG/UWORD/byte to ulg/ush/uch.
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c9 19 Jul 93 J. Bush added more typecasts (to return values);
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made l[256] array static for Amiga.
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c10 8 Oct 93 G. Roelofs added used_csize for diagnostics; added
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buf and unshrink arguments to flush();
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undef'd various macros at end for Turbo C;
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removed NEXTBYTE macro (now in unzip.h)
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and bytebuf variable (not used); changed
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memset() to memzero().
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c11 9 Jan 94 M. Adler fixed incorrect used_csize calculation.
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c12 9 Apr 94 G. Roelofs fixed split comments on preprocessor lines
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to avoid bug in Encore compiler.
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c13 25 Aug 94 M. Adler fixed distance-length comment (orig c9 fix)
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c14 22 Nov 95 S. Maxwell removed unnecessary "static" on auto array
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c15 6 Jul 96 W. Haidinger added ulg typecasts to flush() calls.
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c16 8 Feb 98 C. Spieler added ZCONST modifiers to const tables
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and #ifdef DEBUG around debugging code.
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c16b 25 Mar 98 C. Spieler modified DLL code for slide redirection.
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*/
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/*
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Explode imploded (PKZIP method 6 compressed) data. This compression
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method searches for as much of the current string of bytes (up to a length
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of ~320) in the previous 4K or 8K bytes. If it doesn't find any matches
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(of at least length 2 or 3), it codes the next byte. Otherwise, it codes
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the length of the matched string and its distance backwards from the
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current position. Single bytes ("literals") are preceded by a one (a
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single bit) and are either uncoded (the eight bits go directly into the
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compressed stream for a total of nine bits) or Huffman coded with a
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supplied literal code tree. If literals are coded, then the minimum match
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length is three, otherwise it is two.
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There are therefore four kinds of imploded streams: 8K search with coded
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literals (min match = 3), 4K search with coded literals (min match = 3),
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8K with uncoded literals (min match = 2), and 4K with uncoded literals
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(min match = 2). The kind of stream is identified in two bits of a
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general purpose bit flag that is outside of the compressed stream.
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Distance-length pairs for matched strings are preceded by a zero bit (to
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distinguish them from literals) and are always coded. The distance comes
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first and is either the low six (4K) or low seven (8K) bits of the
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distance (uncoded), followed by the high six bits of the distance coded.
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Then the length is six bits coded (0..63 + min match length), and if the
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maximum such length is coded, then it's followed by another eight bits
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(uncoded) to be added to the coded length. This gives a match length
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range of 2..320 or 3..321 bytes.
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The literal, length, and distance codes are all represented in a slightly
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compressed form themselves. What is sent are the lengths of the codes for
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each value, which is sufficient to construct the codes. Each byte of the
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code representation is the code length (the low four bits representing
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1..16), and the number of values sequentially with that length (the high
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four bits also representing 1..16). There are 256 literal code values (if
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literals are coded), 64 length code values, and 64 distance code values,
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in that order at the beginning of the compressed stream. Each set of code
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values is preceded (redundantly) with a byte indicating how many bytes are
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in the code description that follows, in the range 1..256.
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The codes themselves are decoded using tables made by huft_build() from
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the bit lengths. That routine and its comments are in the inflate.c
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module.
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*/
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#define UNZIP_INTERNAL
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#include "unzip.h" /* must supply slide[] (uch) array and NEXTBYTE macro */
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#ifndef WSIZE
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# define WSIZE 0x8000 /* window size--must be a power of two, and */
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#endif /* at least 8K for zip's implode method */
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#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
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# define wsize G._wsize
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#else
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# define wsize WSIZE
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#endif
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/* routines here */
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static int get_tree OF((__GPRO__ unsigned *l, unsigned n));
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static int explode_lit8 OF((__GPRO__ struct huft *tb, struct huft *tl,
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struct huft *td, int bb, int bl, int bd));
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static int explode_lit4 OF((__GPRO__ struct huft *tb, struct huft *tl,
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struct huft *td, int bb, int bl, int bd));
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static int explode_nolit8 OF((__GPRO__ struct huft *tl, struct huft *td,
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int bl, int bd));
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static int explode_nolit4 OF((__GPRO__ struct huft *tl, struct huft *td,
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int bl, int bd));
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int explode OF((__GPRO));
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/* The implode algorithm uses a sliding 4K or 8K byte window on the
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uncompressed stream to find repeated byte strings. This is implemented
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here as a circular buffer. The index is updated simply by incrementing
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and then and'ing with 0x0fff (4K-1) or 0x1fff (8K-1). Here, the 32K
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buffer of inflate is used, and it works just as well to always have
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a 32K circular buffer, so the index is anded with 0x7fff. This is
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done to allow the window to also be used as the output buffer. */
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/* This must be supplied in an external module useable like "uch slide[8192];"
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or "uch *slide;", where the latter would be malloc'ed. In unzip, slide[]
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is actually a 32K area for use by inflate, which uses a 32K sliding window.
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*/
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/* Tables for length and distance */
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static ZCONST ush cplen2[] =
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{2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
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18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,
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35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
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52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65};
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static ZCONST ush cplen3[] =
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{3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
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19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
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36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,
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53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66};
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static ZCONST ush extra[] =
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{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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8};
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static ZCONST ush cpdist4[] =
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{1, 65, 129, 193, 257, 321, 385, 449, 513, 577, 641, 705,
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769, 833, 897, 961, 1025, 1089, 1153, 1217, 1281, 1345, 1409, 1473,
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1537, 1601, 1665, 1729, 1793, 1857, 1921, 1985, 2049, 2113, 2177,
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2241, 2305, 2369, 2433, 2497, 2561, 2625, 2689, 2753, 2817, 2881,
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2945, 3009, 3073, 3137, 3201, 3265, 3329, 3393, 3457, 3521, 3585,
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3649, 3713, 3777, 3841, 3905, 3969, 4033};
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static ZCONST ush cpdist8[] =
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{1, 129, 257, 385, 513, 641, 769, 897, 1025, 1153, 1281,
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1409, 1537, 1665, 1793, 1921, 2049, 2177, 2305, 2433, 2561, 2689,
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2817, 2945, 3073, 3201, 3329, 3457, 3585, 3713, 3841, 3969, 4097,
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4225, 4353, 4481, 4609, 4737, 4865, 4993, 5121, 5249, 5377, 5505,
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5633, 5761, 5889, 6017, 6145, 6273, 6401, 6529, 6657, 6785, 6913,
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7041, 7169, 7297, 7425, 7553, 7681, 7809, 7937, 8065};
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/* Macros for inflate() bit peeking and grabbing.
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The usage is:
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NEEDBITS(j)
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x = b & mask_bits[j];
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DUMPBITS(j)
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where NEEDBITS makes sure that b has at least j bits in it, and
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DUMPBITS removes the bits from b. The macros use the variable k
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for the number of bits in b. Normally, b and k are register
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variables for speed.
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*/
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#define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE)<<k;k+=8;}}
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#define DUMPBITS(n) {b>>=(n);k-=(n);}
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static int get_tree(__G__ l, n)
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__GDEF
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unsigned *l; /* bit lengths */
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unsigned n; /* number expected */
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/* Get the bit lengths for a code representation from the compressed
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stream. If get_tree() returns 4, then there is an error in the data.
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Otherwise zero is returned. */
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{
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unsigned i; /* bytes remaining in list */
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unsigned k; /* lengths entered */
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unsigned j; /* number of codes */
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unsigned b; /* bit length for those codes */
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/* get bit lengths */
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i = NEXTBYTE + 1; /* length/count pairs to read */
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k = 0; /* next code */
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do {
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b = ((j = NEXTBYTE) & 0xf) + 1; /* bits in code (1..16) */
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j = ((j & 0xf0) >> 4) + 1; /* codes with those bits (1..16) */
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if (k + j > n)
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return 4; /* don't overflow l[] */
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do {
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l[k++] = b;
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} while (--j);
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} while (--i);
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return k != n ? 4 : 0; /* should have read n of them */
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}
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static int explode_lit8(__G__ tb, tl, td, bb, bl, bd)
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__GDEF
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struct huft *tb, *tl, *td; /* literal, length, and distance tables */
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int bb, bl, bd; /* number of bits decoded by those */
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/* Decompress the imploded data using coded literals and an 8K sliding
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window. */
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{
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long s; /* bytes to decompress */
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register unsigned e; /* table entry flag/number of extra bits */
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unsigned n, d; /* length and index for copy */
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unsigned w; /* current window position */
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struct huft *t; /* pointer to table entry */
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unsigned mb, ml, md; /* masks for bb, bl, and bd bits */
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register ulg b; /* bit buffer */
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register unsigned k; /* number of bits in bit buffer */
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unsigned u; /* true if unflushed */
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/* explode the coded data */
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b = k = w = 0; /* initialize bit buffer, window */
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u = 1; /* buffer unflushed */
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mb = mask_bits[bb]; /* precompute masks for speed */
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ml = mask_bits[bl];
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md = mask_bits[bd];
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s = G.ucsize;
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while (s > 0) /* do until ucsize bytes uncompressed */
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{
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NEEDBITS(1)
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if (b & 1) /* then literal--decode it */
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{
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DUMPBITS(1)
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s--;
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NEEDBITS((unsigned)bb) /* get coded literal */
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if ((e = (t = tb + ((~(unsigned)b) & mb))->e) > 16)
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do {
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if (e == 99)
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return 1;
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DUMPBITS(t->b)
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e -= 16;
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NEEDBITS(e)
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} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
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DUMPBITS(t->b)
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redirSlide[w++] = (uch)t->v.n;
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if (w == wsize)
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{
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flush(__G__ redirSlide, (ulg)w, 0);
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w = u = 0;
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}
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}
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else /* else distance/length */
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{
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DUMPBITS(1)
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NEEDBITS(7) /* get distance low bits */
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d = (unsigned)b & 0x7f;
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DUMPBITS(7)
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NEEDBITS((unsigned)bd) /* get coded distance high bits */
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if ((e = (t = td + ((~(unsigned)b) & md))->e) > 16)
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do {
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if (e == 99)
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return 1;
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DUMPBITS(t->b)
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e -= 16;
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NEEDBITS(e)
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} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
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DUMPBITS(t->b)
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d = w - d - t->v.n; /* construct offset */
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NEEDBITS((unsigned)bl) /* get coded length */
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if ((e = (t = tl + ((~(unsigned)b) & ml))->e) > 16)
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do {
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if (e == 99)
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return 1;
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DUMPBITS(t->b)
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e -= 16;
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NEEDBITS(e)
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} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
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DUMPBITS(t->b)
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n = t->v.n;
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if (e) /* get length extra bits */
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{
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NEEDBITS(8)
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n += (unsigned)b & 0xff;
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DUMPBITS(8)
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}
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/* do the copy */
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s -= n;
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do {
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#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
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if (G.redirect_slide) {
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/* &= w/ wsize not needed and wrong if redirect */
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if (d >= wsize)
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return 1;
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n -= (e = (e = wsize - (d > w ? d : w)) > n ? n : e);
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} else
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#endif
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n -= (e = (e = wsize - ((d &= wsize-1) > w ? d : w)) > n ? n : e);
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if (u && w <= d)
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{
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memzero(redirSlide + w, e);
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w += e;
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d += e;
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}
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else
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#ifndef NOMEMCPY
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if (w - d >= e) /* (this test assumes unsigned comparison) */
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{
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memcpy(redirSlide + w, redirSlide + d, e);
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w += e;
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d += e;
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}
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else /* do it slow to avoid memcpy() overlap */
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#endif /* !NOMEMCPY */
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do {
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redirSlide[w++] = redirSlide[d++];
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} while (--e);
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if (w == wsize)
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{
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flush(__G__ redirSlide, (ulg)w, 0);
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w = u = 0;
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}
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} while (n);
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}
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}
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/* flush out redirSlide */
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flush(__G__ redirSlide, (ulg)w, 0);
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if (G.csize + G.incnt + (k >> 3)) /* should have read csize bytes, but */
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{ /* sometimes read one too many: k>>3 compensates */
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G.used_csize = G.lrec.csize - G.csize - G.incnt - (k >> 3);
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return 5;
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}
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return 0;
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}
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static int explode_lit4(__G__ tb, tl, td, bb, bl, bd)
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__GDEF
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struct huft *tb, *tl, *td; /* literal, length, and distance tables */
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int bb, bl, bd; /* number of bits decoded by those */
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/* Decompress the imploded data using coded literals and a 4K sliding
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window. */
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{
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long s; /* bytes to decompress */
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register unsigned e; /* table entry flag/number of extra bits */
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unsigned n, d; /* length and index for copy */
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unsigned w; /* current window position */
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struct huft *t; /* pointer to table entry */
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unsigned mb, ml, md; /* masks for bb, bl, and bd bits */
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register ulg b; /* bit buffer */
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register unsigned k; /* number of bits in bit buffer */
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unsigned u; /* true if unflushed */
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/* explode the coded data */
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b = k = w = 0; /* initialize bit buffer, window */
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u = 1; /* buffer unflushed */
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mb = mask_bits[bb]; /* precompute masks for speed */
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ml = mask_bits[bl];
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md = mask_bits[bd];
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s = G.ucsize;
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while (s > 0) /* do until ucsize bytes uncompressed */
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{
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NEEDBITS(1)
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if (b & 1) /* then literal--decode it */
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{
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DUMPBITS(1)
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s--;
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NEEDBITS((unsigned)bb) /* get coded literal */
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if ((e = (t = tb + ((~(unsigned)b) & mb))->e) > 16)
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do {
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if (e == 99)
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return 1;
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DUMPBITS(t->b)
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e -= 16;
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NEEDBITS(e)
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} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
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DUMPBITS(t->b)
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redirSlide[w++] = (uch)t->v.n;
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if (w == wsize)
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{
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flush(__G__ redirSlide, (ulg)w, 0);
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w = u = 0;
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}
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}
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else /* else distance/length */
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{
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DUMPBITS(1)
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NEEDBITS(6) /* get distance low bits */
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d = (unsigned)b & 0x3f;
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DUMPBITS(6)
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NEEDBITS((unsigned)bd) /* get coded distance high bits */
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if ((e = (t = td + ((~(unsigned)b) & md))->e) > 16)
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do {
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if (e == 99)
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return 1;
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DUMPBITS(t->b)
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e -= 16;
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NEEDBITS(e)
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} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
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DUMPBITS(t->b)
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d = w - d - t->v.n; /* construct offset */
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NEEDBITS((unsigned)bl) /* get coded length */
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if ((e = (t = tl + ((~(unsigned)b) & ml))->e) > 16)
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do {
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if (e == 99)
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return 1;
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DUMPBITS(t->b)
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e -= 16;
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NEEDBITS(e)
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} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
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DUMPBITS(t->b)
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n = t->v.n;
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if (e) /* get length extra bits */
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{
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NEEDBITS(8)
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n += (unsigned)b & 0xff;
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DUMPBITS(8)
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}
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/* do the copy */
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s -= n;
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do {
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#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
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if (G.redirect_slide) {
|
|
/* &= w/ wsize not needed and wrong if redirect */
|
|
if (d >= wsize)
|
|
return 1;
|
|
n -= (e = (e = wsize - (d > w ? d : w)) > n ? n : e);
|
|
} else
|
|
#endif
|
|
n -= (e = (e = wsize - ((d &= wsize-1) > w ? d : w)) > n ? n : e);
|
|
if (u && w <= d)
|
|
{
|
|
memzero(redirSlide + w, e);
|
|
w += e;
|
|
d += e;
|
|
}
|
|
else
|
|
#ifndef NOMEMCPY
|
|
if (w - d >= e) /* (this test assumes unsigned comparison) */
|
|
{
|
|
memcpy(redirSlide + w, redirSlide + d, e);
|
|
w += e;
|
|
d += e;
|
|
}
|
|
else /* do it slow to avoid memcpy() overlap */
|
|
#endif /* !NOMEMCPY */
|
|
do {
|
|
redirSlide[w++] = redirSlide[d++];
|
|
} while (--e);
|
|
if (w == wsize)
|
|
{
|
|
flush(__G__ redirSlide, (ulg)w, 0);
|
|
w = u = 0;
|
|
}
|
|
} while (n);
|
|
}
|
|
}
|
|
|
|
/* flush out redirSlide */
|
|
flush(__G__ redirSlide, (ulg)w, 0);
|
|
if (G.csize + G.incnt + (k >> 3)) /* should have read csize bytes, but */
|
|
{ /* sometimes read one too many: k>>3 compensates */
|
|
G.used_csize = G.lrec.csize - G.csize - G.incnt - (k >> 3);
|
|
return 5;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
static int explode_nolit8(__G__ tl, td, bl, bd)
|
|
__GDEF
|
|
struct huft *tl, *td; /* length and distance decoder tables */
|
|
int bl, bd; /* number of bits decoded by tl[] and td[] */
|
|
/* Decompress the imploded data using uncoded literals and an 8K sliding
|
|
window. */
|
|
{
|
|
long s; /* bytes to decompress */
|
|
register unsigned e; /* table entry flag/number of extra bits */
|
|
unsigned n, d; /* length and index for copy */
|
|
unsigned w; /* current window position */
|
|
struct huft *t; /* pointer to table entry */
|
|
unsigned ml, md; /* masks for bl and bd bits */
|
|
register ulg b; /* bit buffer */
|
|
register unsigned k; /* number of bits in bit buffer */
|
|
unsigned u; /* true if unflushed */
|
|
|
|
|
|
/* explode the coded data */
|
|
b = k = w = 0; /* initialize bit buffer, window */
|
|
u = 1; /* buffer unflushed */
|
|
ml = mask_bits[bl]; /* precompute masks for speed */
|
|
md = mask_bits[bd];
|
|
s = G.ucsize;
|
|
while (s > 0) /* do until ucsize bytes uncompressed */
|
|
{
|
|
NEEDBITS(1)
|
|
if (b & 1) /* then literal--get eight bits */
|
|
{
|
|
DUMPBITS(1)
|
|
s--;
|
|
NEEDBITS(8)
|
|
redirSlide[w++] = (uch)b;
|
|
if (w == wsize)
|
|
{
|
|
flush(__G__ redirSlide, (ulg)w, 0);
|
|
w = u = 0;
|
|
}
|
|
DUMPBITS(8)
|
|
}
|
|
else /* else distance/length */
|
|
{
|
|
DUMPBITS(1)
|
|
NEEDBITS(7) /* get distance low bits */
|
|
d = (unsigned)b & 0x7f;
|
|
DUMPBITS(7)
|
|
NEEDBITS((unsigned)bd) /* get coded distance high bits */
|
|
if ((e = (t = td + ((~(unsigned)b) & md))->e) > 16)
|
|
do {
|
|
if (e == 99)
|
|
return 1;
|
|
DUMPBITS(t->b)
|
|
e -= 16;
|
|
NEEDBITS(e)
|
|
} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
|
|
DUMPBITS(t->b)
|
|
d = w - d - t->v.n; /* construct offset */
|
|
NEEDBITS((unsigned)bl) /* get coded length */
|
|
if ((e = (t = tl + ((~(unsigned)b) & ml))->e) > 16)
|
|
do {
|
|
if (e == 99)
|
|
return 1;
|
|
DUMPBITS(t->b)
|
|
e -= 16;
|
|
NEEDBITS(e)
|
|
} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
|
|
DUMPBITS(t->b)
|
|
n = t->v.n;
|
|
if (e) /* get length extra bits */
|
|
{
|
|
NEEDBITS(8)
|
|
n += (unsigned)b & 0xff;
|
|
DUMPBITS(8)
|
|
}
|
|
|
|
/* do the copy */
|
|
s -= n;
|
|
do {
|
|
#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
|
|
if (G.redirect_slide) {
|
|
/* &= w/ wsize not needed and wrong if redirect */
|
|
if (d >= wsize)
|
|
return 1;
|
|
n -= (e = (e = wsize - (d > w ? d : w)) > n ? n : e);
|
|
} else
|
|
#endif
|
|
n -= (e = (e = wsize - ((d &= wsize-1) > w ? d : w)) > n ? n : e);
|
|
if (u && w <= d)
|
|
{
|
|
memzero(redirSlide + w, e);
|
|
w += e;
|
|
d += e;
|
|
}
|
|
else
|
|
#ifndef NOMEMCPY
|
|
if (w - d >= e) /* (this test assumes unsigned comparison) */
|
|
{
|
|
memcpy(redirSlide + w, redirSlide + d, e);
|
|
w += e;
|
|
d += e;
|
|
}
|
|
else /* do it slow to avoid memcpy() overlap */
|
|
#endif /* !NOMEMCPY */
|
|
do {
|
|
redirSlide[w++] = redirSlide[d++];
|
|
} while (--e);
|
|
if (w == wsize)
|
|
{
|
|
flush(__G__ redirSlide, (ulg)w, 0);
|
|
w = u = 0;
|
|
}
|
|
} while (n);
|
|
}
|
|
}
|
|
|
|
/* flush out redirSlide */
|
|
flush(__G__ redirSlide, (ulg)w, 0);
|
|
if (G.csize + G.incnt + (k >> 3)) /* should have read csize bytes, but */
|
|
{ /* sometimes read one too many: k>>3 compensates */
|
|
G.used_csize = G.lrec.csize - G.csize - G.incnt - (k >> 3);
|
|
return 5;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
static int explode_nolit4(__G__ tl, td, bl, bd)
|
|
__GDEF
|
|
struct huft *tl, *td; /* length and distance decoder tables */
|
|
int bl, bd; /* number of bits decoded by tl[] and td[] */
|
|
/* Decompress the imploded data using uncoded literals and a 4K sliding
|
|
window. */
|
|
{
|
|
long s; /* bytes to decompress */
|
|
register unsigned e; /* table entry flag/number of extra bits */
|
|
unsigned n, d; /* length and index for copy */
|
|
unsigned w; /* current window position */
|
|
struct huft *t; /* pointer to table entry */
|
|
unsigned ml, md; /* masks for bl and bd bits */
|
|
register ulg b; /* bit buffer */
|
|
register unsigned k; /* number of bits in bit buffer */
|
|
unsigned u; /* true if unflushed */
|
|
|
|
|
|
/* explode the coded data */
|
|
b = k = w = 0; /* initialize bit buffer, window */
|
|
u = 1; /* buffer unflushed */
|
|
ml = mask_bits[bl]; /* precompute masks for speed */
|
|
md = mask_bits[bd];
|
|
s = G.ucsize;
|
|
while (s > 0) /* do until ucsize bytes uncompressed */
|
|
{
|
|
NEEDBITS(1)
|
|
if (b & 1) /* then literal--get eight bits */
|
|
{
|
|
DUMPBITS(1)
|
|
s--;
|
|
NEEDBITS(8)
|
|
redirSlide[w++] = (uch)b;
|
|
if (w == wsize)
|
|
{
|
|
flush(__G__ redirSlide, (ulg)w, 0);
|
|
w = u = 0;
|
|
}
|
|
DUMPBITS(8)
|
|
}
|
|
else /* else distance/length */
|
|
{
|
|
DUMPBITS(1)
|
|
NEEDBITS(6) /* get distance low bits */
|
|
d = (unsigned)b & 0x3f;
|
|
DUMPBITS(6)
|
|
NEEDBITS((unsigned)bd) /* get coded distance high bits */
|
|
if ((e = (t = td + ((~(unsigned)b) & md))->e) > 16)
|
|
do {
|
|
if (e == 99)
|
|
return 1;
|
|
DUMPBITS(t->b)
|
|
e -= 16;
|
|
NEEDBITS(e)
|
|
} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
|
|
DUMPBITS(t->b)
|
|
d = w - d - t->v.n; /* construct offset */
|
|
NEEDBITS((unsigned)bl) /* get coded length */
|
|
if ((e = (t = tl + ((~(unsigned)b) & ml))->e) > 16)
|
|
do {
|
|
if (e == 99)
|
|
return 1;
|
|
DUMPBITS(t->b)
|
|
e -= 16;
|
|
NEEDBITS(e)
|
|
} while ((e = (t = t->v.t + ((~(unsigned)b) & mask_bits[e]))->e) > 16);
|
|
DUMPBITS(t->b)
|
|
n = t->v.n;
|
|
if (e) /* get length extra bits */
|
|
{
|
|
NEEDBITS(8)
|
|
n += (unsigned)b & 0xff;
|
|
DUMPBITS(8)
|
|
}
|
|
|
|
/* do the copy */
|
|
s -= n;
|
|
do {
|
|
#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
|
|
if (G.redirect_slide) {
|
|
/* &= w/ wsize not needed and wrong if redirect */
|
|
if (d >= wsize)
|
|
return 1;
|
|
n -= (e = (e = wsize - (d > w ? d : w)) > n ? n : e);
|
|
} else
|
|
#endif
|
|
n -= (e = (e = wsize - ((d &= wsize-1) > w ? d : w)) > n ? n : e);
|
|
if (u && w <= d)
|
|
{
|
|
memzero(redirSlide + w, e);
|
|
w += e;
|
|
d += e;
|
|
}
|
|
else
|
|
#ifndef NOMEMCPY
|
|
if (w - d >= e) /* (this test assumes unsigned comparison) */
|
|
{
|
|
memcpy(redirSlide + w, redirSlide + d, e);
|
|
w += e;
|
|
d += e;
|
|
}
|
|
else /* do it slow to avoid memcpy() overlap */
|
|
#endif /* !NOMEMCPY */
|
|
do {
|
|
redirSlide[w++] = redirSlide[d++];
|
|
} while (--e);
|
|
if (w == wsize)
|
|
{
|
|
flush(__G__ redirSlide, (ulg)w, 0);
|
|
w = u = 0;
|
|
}
|
|
} while (n);
|
|
}
|
|
}
|
|
|
|
/* flush out redirSlide */
|
|
flush(__G__ redirSlide, (ulg)w, 0);
|
|
if (G.csize + G.incnt + (k >> 3)) /* should have read csize bytes, but */
|
|
{ /* sometimes read one too many: k>>3 compensates */
|
|
G.used_csize = G.lrec.csize - G.csize - G.incnt - (k >> 3);
|
|
return 5;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
int explode(__G)
|
|
__GDEF
|
|
/* Explode an imploded compressed stream. Based on the general purpose
|
|
bit flag, decide on coded or uncoded literals, and an 8K or 4K sliding
|
|
window. Construct the literal (if any), length, and distance codes and
|
|
the tables needed to decode them (using huft_build() from inflate.c),
|
|
and call the appropriate routine for the type of data in the remainder
|
|
of the stream. The four routines are nearly identical, differing only
|
|
in whether the literal is decoded or simply read in, and in how many
|
|
bits are read in, uncoded, for the low distance bits. */
|
|
{
|
|
unsigned r; /* return codes */
|
|
struct huft *tb; /* literal code table */
|
|
struct huft *tl; /* length code table */
|
|
struct huft *td; /* distance code table */
|
|
int bb; /* bits for tb */
|
|
int bl; /* bits for tl */
|
|
int bd; /* bits for td */
|
|
unsigned l[256]; /* bit lengths for codes */
|
|
|
|
#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
|
|
if (G.redirect_slide)
|
|
wsize = G.redirect_size, redirSlide = G.redirect_buffer;
|
|
else
|
|
wsize = WSIZE, redirSlide = slide;
|
|
#endif
|
|
|
|
/* Tune base table sizes. Note: I thought that to truly optimize speed,
|
|
I would have to select different bl, bd, and bb values for different
|
|
compressed file sizes. I was surprised to find out that the values of
|
|
7, 7, and 9 worked best over a very wide range of sizes, except that
|
|
bd = 8 worked marginally better for large compressed sizes. */
|
|
bl = 7;
|
|
bd = (G.csize + G.incnt) > 200000L ? 8 : 7;
|
|
|
|
|
|
/* With literal tree--minimum match length is 3 */
|
|
#ifdef DEBUG
|
|
G.hufts = 0; /* initialize huft's malloc'ed */
|
|
#endif
|
|
if (G.lrec.general_purpose_bit_flag & 4)
|
|
{
|
|
bb = 9; /* base table size for literals */
|
|
if ((r = get_tree(__G__ l, 256)) != 0)
|
|
return (int)r;
|
|
if ((r = huft_build(__G__ l, 256, 256, NULL, NULL, &tb, &bb)) != 0)
|
|
{
|
|
if (r == 1)
|
|
huft_free(tb);
|
|
return (int)r;
|
|
}
|
|
if ((r = get_tree(__G__ l, 64)) != 0)
|
|
return (int)r;
|
|
if ((r = huft_build(__G__ l, 64, 0, cplen3, extra, &tl, &bl)) != 0)
|
|
{
|
|
if (r == 1)
|
|
huft_free(tl);
|
|
huft_free(tb);
|
|
return (int)r;
|
|
}
|
|
if ((r = get_tree(__G__ l, 64)) != 0)
|
|
return (int)r;
|
|
if (G.lrec.general_purpose_bit_flag & 2) /* true if 8K */
|
|
{
|
|
if ((r = huft_build(__G__ l, 64, 0, cpdist8, extra, &td, &bd)) != 0)
|
|
{
|
|
if (r == 1)
|
|
huft_free(td);
|
|
huft_free(tl);
|
|
huft_free(tb);
|
|
return (int)r;
|
|
}
|
|
r = explode_lit8(__G__ tb, tl, td, bb, bl, bd);
|
|
}
|
|
else /* else 4K */
|
|
{
|
|
if ((r = huft_build(__G__ l, 64, 0, cpdist4, extra, &td, &bd)) != 0)
|
|
{
|
|
if (r == 1)
|
|
huft_free(td);
|
|
huft_free(tl);
|
|
huft_free(tb);
|
|
return (int)r;
|
|
}
|
|
r = explode_lit4(__G__ tb, tl, td, bb, bl, bd);
|
|
}
|
|
huft_free(td);
|
|
huft_free(tl);
|
|
huft_free(tb);
|
|
}
|
|
else
|
|
|
|
|
|
/* No literal tree--minimum match length is 2 */
|
|
{
|
|
if ((r = get_tree(__G__ l, 64)) != 0)
|
|
return (int)r;
|
|
if ((r = huft_build(__G__ l, 64, 0, cplen2, extra, &tl, &bl)) != 0)
|
|
{
|
|
if (r == 1)
|
|
huft_free(tl);
|
|
return (int)r;
|
|
}
|
|
if ((r = get_tree(__G__ l, 64)) != 0)
|
|
return (int)r;
|
|
if (G.lrec.general_purpose_bit_flag & 2) /* true if 8K */
|
|
{
|
|
if ((r = huft_build(__G__ l, 64, 0, cpdist8, extra, &td, &bd)) != 0)
|
|
{
|
|
if (r == 1)
|
|
huft_free(td);
|
|
huft_free(tl);
|
|
return (int)r;
|
|
}
|
|
r = explode_nolit8(__G__ tl, td, bl, bd);
|
|
}
|
|
else /* else 4K */
|
|
{
|
|
if ((r = huft_build(__G__ l, 64, 0, cpdist4, extra, &td, &bd)) != 0)
|
|
{
|
|
if (r == 1)
|
|
huft_free(td);
|
|
huft_free(tl);
|
|
return (int)r;
|
|
}
|
|
r = explode_nolit4(__G__ tl, td, bl, bd);
|
|
}
|
|
huft_free(td);
|
|
huft_free(tl);
|
|
}
|
|
Trace((stderr, "<%u > ", G.hufts));
|
|
return (int)r;
|
|
}
|
|
|
|
/* so explode.c and inflate.c can be compiled together into one object: */
|
|
#undef NEXTBYTE
|
|
#undef NEEDBITS
|
|
#undef DUMPBITS
|