summaryrefslogtreecommitdiff
path: root/Build/source/libs/unzip/explode.c
diff options
context:
space:
mode:
Diffstat (limited to 'Build/source/libs/unzip/explode.c')
-rw-r--r--Build/source/libs/unzip/explode.c871
1 files changed, 871 insertions, 0 deletions
diff --git a/Build/source/libs/unzip/explode.c b/Build/source/libs/unzip/explode.c
new file mode 100644
index 00000000000..c1a8f80032a
--- /dev/null
+++ b/Build/source/libs/unzip/explode.c
@@ -0,0 +1,871 @@
+/* explode.c -- put in the public domain by Mark Adler
+ version c15, 6 July 1996 */
+
+
+/* You can do whatever you like with this source file, though I would
+ prefer that if you modify it and redistribute it that you include
+ comments to that effect with your name and the date. Thank you.
+
+ History:
+ vers date who what
+ ---- --------- -------------- ------------------------------------
+ c1 30 Mar 92 M. Adler explode that uses huft_build from inflate
+ (this gives over a 70% speed improvement
+ over the original unimplode.c, which
+ decoded a bit at a time)
+ c2 4 Apr 92 M. Adler fixed bug for file sizes a multiple of 32k.
+ c3 10 Apr 92 M. Adler added a little memory tracking if DEBUG
+ c4 11 Apr 92 M. Adler added NOMEMCPY do kill use of memcpy()
+ c5 21 Apr 92 M. Adler added the WSIZE #define to allow reducing
+ the 32K window size for specialized
+ applications.
+ c6 31 May 92 M. Adler added typecasts to eliminate some warnings
+ c7 27 Jun 92 G. Roelofs added more typecasts.
+ c8 17 Oct 92 G. Roelofs changed ULONG/UWORD/byte to ulg/ush/uch.
+ c9 19 Jul 93 J. Bush added more typecasts (to return values);
+ made l[256] array static for Amiga.
+ c10 8 Oct 93 G. Roelofs added used_csize for diagnostics; added
+ buf and unshrink arguments to flush();
+ undef'd various macros at end for Turbo C;
+ removed NEXTBYTE macro (now in unzip.h)
+ and bytebuf variable (not used); changed
+ memset() to memzero().
+ c11 9 Jan 94 M. Adler fixed incorrect used_csize calculation.
+ c12 9 Apr 94 G. Roelofs fixed split comments on preprocessor lines
+ to avoid bug in Encore compiler.
+ c13 25 Aug 94 M. Adler fixed distance-length comment (orig c9 fix)
+ c14 22 Nov 95 S. Maxwell removed unnecessary "static" on auto array
+ c15 6 Jul 96 W. Haidinger added ulg typecasts to flush() calls.
+ c16 8 Feb 98 C. Spieler added ZCONST modifiers to const tables
+ and #ifdef DEBUG around debugging code.
+ c16b 25 Mar 98 C. Spieler modified DLL code for slide redirection.
+ */
+
+
+/*
+ Explode imploded (PKZIP method 6 compressed) data. This compression
+ method searches for as much of the current string of bytes (up to a length
+ of ~320) in the previous 4K or 8K bytes. If it doesn't find any matches
+ (of at least length 2 or 3), it codes the next byte. Otherwise, it codes
+ the length of the matched string and its distance backwards from the
+ current position. Single bytes ("literals") are preceded by a one (a
+ single bit) and are either uncoded (the eight bits go directly into the
+ compressed stream for a total of nine bits) or Huffman coded with a
+ supplied literal code tree. If literals are coded, then the minimum match
+ length is three, otherwise it is two.
+
+ There are therefore four kinds of imploded streams: 8K search with coded
+ literals (min match = 3), 4K search with coded literals (min match = 3),
+ 8K with uncoded literals (min match = 2), and 4K with uncoded literals
+ (min match = 2). The kind of stream is identified in two bits of a
+ general purpose bit flag that is outside of the compressed stream.
+
+ Distance-length pairs for matched strings are preceded by a zero bit (to
+ distinguish them from literals) and are always coded. The distance comes
+ first and is either the low six (4K) or low seven (8K) bits of the
+ distance (uncoded), followed by the high six bits of the distance coded.
+ Then the length is six bits coded (0..63 + min match length), and if the
+ maximum such length is coded, then it's followed by another eight bits
+ (uncoded) to be added to the coded length. This gives a match length
+ range of 2..320 or 3..321 bytes.
+
+ The literal, length, and distance codes are all represented in a slightly
+ compressed form themselves. What is sent are the lengths of the codes for
+ each value, which is sufficient to construct the codes. Each byte of the
+ code representation is the code length (the low four bits representing
+ 1..16), and the number of values sequentially with that length (the high
+ four bits also representing 1..16). There are 256 literal code values (if
+ literals are coded), 64 length code values, and 64 distance code values,
+ in that order at the beginning of the compressed stream. Each set of code
+ values is preceded (redundantly) with a byte indicating how many bytes are
+ in the code description that follows, in the range 1..256.
+
+ The codes themselves are decoded using tables made by huft_build() from
+ the bit lengths. That routine and its comments are in the inflate.c
+ module.
+ */
+
+#define UNZIP_INTERNAL
+#include "unzip.h" /* must supply slide[] (uch) array and NEXTBYTE macro */
+
+#ifndef WSIZE
+# define WSIZE 0x8000 /* window size--must be a power of two, and */
+#endif /* at least 8K for zip's implode method */
+
+#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
+# define wsize G._wsize
+#else
+# define wsize WSIZE
+#endif
+
+/* routines here */
+static int get_tree OF((__GPRO__ unsigned *l, unsigned n));
+static int explode_lit8 OF((__GPRO__ struct huft *tb, struct huft *tl,
+ struct huft *td, int bb, int bl, int bd));
+static int explode_lit4 OF((__GPRO__ struct huft *tb, struct huft *tl,
+ struct huft *td, int bb, int bl, int bd));
+static int explode_nolit8 OF((__GPRO__ struct huft *tl, struct huft *td,
+ int bl, int bd));
+static int explode_nolit4 OF((__GPRO__ struct huft *tl, struct huft *td,
+ int bl, int bd));
+int explode OF((__GPRO));
+
+
+/* The implode algorithm uses a sliding 4K or 8K byte window on the
+ uncompressed stream to find repeated byte strings. This is implemented
+ here as a circular buffer. The index is updated simply by incrementing
+ and then and'ing with 0x0fff (4K-1) or 0x1fff (8K-1). Here, the 32K
+ buffer of inflate is used, and it works just as well to always have
+ a 32K circular buffer, so the index is anded with 0x7fff. This is
+ done to allow the window to also be used as the output buffer. */
+/* This must be supplied in an external module useable like "uch slide[8192];"
+ or "uch *slide;", where the latter would be malloc'ed. In unzip, slide[]
+ is actually a 32K area for use by inflate, which uses a 32K sliding window.
+ */
+
+
+/* Tables for length and distance */
+static ZCONST ush cplen2[] =
+ {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
+ 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,
+ 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
+ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65};
+static ZCONST ush cplen3[] =
+ {3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
+ 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
+ 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,
+ 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66};
+static ZCONST ush extra[] =
+ {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 8};
+static ZCONST ush cpdist4[] =
+ {1, 65, 129, 193, 257, 321, 385, 449, 513, 577, 641, 705,
+ 769, 833, 897, 961, 1025, 1089, 1153, 1217, 1281, 1345, 1409, 1473,
+ 1537, 1601, 1665, 1729, 1793, 1857, 1921, 1985, 2049, 2113, 2177,
+ 2241, 2305, 2369, 2433, 2497, 2561, 2625, 2689, 2753, 2817, 2881,
+ 2945, 3009, 3073, 3137, 3201, 3265, 3329, 3393, 3457, 3521, 3585,
+ 3649, 3713, 3777, 3841, 3905, 3969, 4033};
+static ZCONST ush cpdist8[] =
+ {1, 129, 257, 385, 513, 641, 769, 897, 1025, 1153, 1281,
+ 1409, 1537, 1665, 1793, 1921, 2049, 2177, 2305, 2433, 2561, 2689,
+ 2817, 2945, 3073, 3201, 3329, 3457, 3585, 3713, 3841, 3969, 4097,
+ 4225, 4353, 4481, 4609, 4737, 4865, 4993, 5121, 5249, 5377, 5505,
+ 5633, 5761, 5889, 6017, 6145, 6273, 6401, 6529, 6657, 6785, 6913,
+ 7041, 7169, 7297, 7425, 7553, 7681, 7809, 7937, 8065};
+
+
+/* Macros for inflate() bit peeking and grabbing.
+ The usage is:
+
+ NEEDBITS(j)
+ x = b & mask_bits[j];
+ DUMPBITS(j)
+
+ where NEEDBITS makes sure that b has at least j bits in it, and
+ DUMPBITS removes the bits from b. The macros use the variable k
+ for the number of bits in b. Normally, b and k are register
+ variables for speed.
+ */
+
+#define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE)<<k;k+=8;}}
+#define DUMPBITS(n) {b>>=(n);k-=(n);}
+
+
+
+static int get_tree(__G__ l, n)
+ __GDEF
+unsigned *l; /* bit lengths */
+unsigned n; /* number expected */
+/* Get the bit lengths for a code representation from the compressed
+ stream. If get_tree() returns 4, then there is an error in the data.
+ Otherwise zero is returned. */
+{
+ unsigned i; /* bytes remaining in list */
+ unsigned k; /* lengths entered */
+ unsigned j; /* number of codes */
+ unsigned b; /* bit length for those codes */
+
+
+ /* get bit lengths */
+ i = NEXTBYTE + 1; /* length/count pairs to read */
+ k = 0; /* next code */
+ do {
+ b = ((j = NEXTBYTE) & 0xf) + 1; /* bits in code (1..16) */
+ j = ((j & 0xf0) >> 4) + 1; /* codes with those bits (1..16) */
+ if (k + j > n)
+ return 4; /* don't overflow l[] */
+ do {
+ l[k++] = b;
+ } while (--j);
+ } while (--i);
+ return k != n ? 4 : 0; /* should have read n of them */
+}
+
+
+
+static int explode_lit8(__G__ tb, tl, td, bb, bl, bd)
+ __GDEF
+struct huft *tb, *tl, *td; /* literal, length, and distance tables */
+int bb, bl, bd; /* number of bits decoded by those */
+/* Decompress the imploded data using coded 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 mb, ml, md; /* masks for bb, 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 */
+ mb = mask_bits[bb]; /* precompute masks for speed */
+ ml = mask_bits[bl];
+ md = mask_bits[bd];
+ s = G.ucsize;
+ while (s > 0) /* do until ucsize bytes uncompressed */
+ {
+ NEEDBITS(1)
+ if (b & 1) /* then literal--decode it */
+ {
+ DUMPBITS(1)
+ s--;
+ NEEDBITS((unsigned)bb) /* get coded literal */
+ if ((e = (t = tb + ((~(unsigned)b) & mb))->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)
+ redirSlide[w++] = (uch)t->v.n;
+ if (w == wsize)
+ {
+ flush(__G__ redirSlide, (ulg)w, 0);
+ w = u = 0;
+ }
+ }
+ 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_lit4(__G__ tb, tl, td, bb, bl, bd)
+ __GDEF
+struct huft *tb, *tl, *td; /* literal, length, and distance tables */
+int bb, bl, bd; /* number of bits decoded by those */
+/* Decompress the imploded data using coded 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 mb, ml, md; /* masks for bb, 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 */
+ mb = mask_bits[bb]; /* precompute masks for speed */
+ ml = mask_bits[bl];
+ md = mask_bits[bd];
+ s = G.ucsize;
+ while (s > 0) /* do until ucsize bytes uncompressed */
+ {
+ NEEDBITS(1)
+ if (b & 1) /* then literal--decode it */
+ {
+ DUMPBITS(1)
+ s--;
+ NEEDBITS((unsigned)bb) /* get coded literal */
+ if ((e = (t = tb + ((~(unsigned)b) & mb))->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)
+ redirSlide[w++] = (uch)t->v.n;
+ if (w == wsize)
+ {
+ flush(__G__ redirSlide, (ulg)w, 0);
+ w = u = 0;
+ }
+ }
+ 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;
+}
+
+
+
+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