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+/* explode.c -- Not copyrighted 1992 by Mark Adler
+ version c7, 27 June 1992 */
+
+
+/* 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
+ */
+
+
+/*
+ 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 are always coded. 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.
+ */
+
+#include "unz.h" /* this must supply the slide[] (byte) array */
+#include "unzipP.h"
+//#include <stdlib.h>
+#include "ds2_malloc.h"
+
+#ifndef WSIZE
+# define WSIZE 0x8000 /* window size--must be a power of two, and at least
+ 8K for zip's implode method */
+#endif /* !WSIZE */
+
+
+struct huft {
+ byte e; /* number of extra bits or operation */
+ byte b; /* number of bits in this code or subcode */
+ union {
+ UWORD n; /* literal, length base, or distance base */
+ struct huft *t; /* pointer to next level of table */
+ } v;
+};
+
+/* Function prototypes */
+/* routines from inflate.c */
+extern unsigned hufts;
+int huft_build OF((unsigned *, unsigned, unsigned, UWORD *, UWORD *,
+ struct huft **, int *));
+int huft_free OF((struct huft *));
+void flush OF((unsigned));
+
+/* routines here */
+int get_tree OF((unsigned *, unsigned));
+int explode_lit8 OF((struct huft *, struct huft *, struct huft *,
+ int, int, int));
+int explode_lit4 OF((struct huft *, struct huft *, struct huft *,
+ int, int, int));
+int explode_nolit8 OF((struct huft *, struct huft *, int, int));
+int explode_nolit4 OF((struct huft *, struct huft *, int, int));
+int explode ();
+
+extern file_in_zip_read_info_s *pfile_in_zip_read_info;
+extern unz_s *pUnzip;
+
+/* 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 "byte slide[8192];"
+ or "byte *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 */
+UWORD 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};
+UWORD 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};
+UWORD 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};
+UWORD 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};
+UWORD 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.
+ */
+
+extern UWORD bytebuf; /* (use the one in inflate.c) */
+#define NEXTBYTE (ReadByte(&bytebuf), bytebuf)
+#define NEEDBITS(n) {while(k<(n)){b|=((ULONG)NEXTBYTE)<<k;k+=8;}}
+#define DUMPBITS(n) {b>>=(n);k-=(n);}
+
+/* HERE */
+UWORD mask_bits[] = {
+ 0x0000,
+ 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
+ 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
+};
+union work area; /* see unzip.h for the definition of work */
+ULONG crc32val;
+ush bytebuf;
+ULONG bitbuf;
+int bits_left;
+boolean zipeof;
+
+int get_tree(l, n)
+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 */
+ ReadByte(&bytebuf);
+ i = bytebuf + 1; /* length/count pairs to read */
+ k = 0; /* next code */
+ do {
+ ReadByte(&bytebuf);
+ b = ((j = bytebuf) & 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 */
+}
+
+
+
+int explode_lit8(tb, tl, td, bb, bl, bd)
+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. */
+{
+ longint 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 ULONG 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 = pUnzip->pfile_in_zip_read->rest_read_uncompressed;
+ 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)
+ slide[w++] = (byte)t->v.n;
+ if (w == WSIZE)
+ {
+ flush(w);
+ 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 {
+ n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);
+ if (u && w <= d)
+ {
+ memset(slide + w, 0, e);
+ w += e;
+ d += e;
+ }
+ else
+#ifndef NOMEMCPY
+ if (w - d >= e) /* (this test assumes unsigned comparison) */
+ {
+ memcpy(slide + w, slide + d, e);
+ w += e;
+ d += e;
+ }
+ else /* do it slow to avoid memcpy() overlap */
+#endif /* !NOMEMCPY */
+ do {
+ slide[w++] = slide[d++];
+ } while (--e);
+ if (w == WSIZE)
+ {
+ flush(w);
+ w = u = 0;
+ }
+ } while (n);
+ }
+ }
+
+ /* flush out slide */
+ flush(w);
+ return pfile_in_zip_read_info->rest_read_compressed ? 5 : 0; /* should have read csize bytes */
+}
+
+
+
+int explode_lit4(tb, tl, td, bb, bl, bd)
+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. */
+{
+ longint 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 ULONG 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 = pUnzip->pfile_in_zip_read->rest_read_uncompressed;
+ 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)
+ slide[w++] = (byte)t->v.n;
+ if (w == WSIZE)
+ {
+ flush(w);
+ 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 {
+ n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);
+ if (u && w <= d)
+ {
+ memset(slide + w, 0, e);
+ w += e;
+ d += e;
+ }
+ else
+#ifndef NOMEMCPY
+ if (w - d >= e) /* (this test assumes unsigned comparison) */
+ {
+ memcpy(slide + w, slide + d, e);
+ w += e;
+ d += e;
+ }
+ else /* do it slow to avoid memcpy() overlap */
+#endif /* !NOMEMCPY */
+ do {
+ slide[w++] = slide[d++];
+ } while (--e);
+ if (w == WSIZE)
+ {
+ flush(w);
+ w = u = 0;
+ }
+ } while (n);
+ }
+ }
+
+ /* flush out slide */
+ flush(w);
+ return pfile_in_zip_read_info->rest_read_compressed ? 5 : 0; /* should have read csize bytes */
+}
+
+
+
+int explode_nolit8(tl, td, bl, bd)
+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. */
+{
+ longint 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 ULONG 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 = pUnzip->pfile_in_zip_read->rest_read_uncompressed;
+ while (s > 0) /* do until ucsize bytes uncompressed */
+ {
+ NEEDBITS(1)
+ if (b & 1) /* then literal--get eight bits */
+ {
+ DUMPBITS(1)
+ s--;
+ NEEDBITS(8)
+ slide[w++] = (byte)b;
+ if (w == WSIZE)
+ {
+ flush(w);
+ 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 {
+ n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);
+ if (u && w <= d)
+ {
+ memset(slide + w, 0, e);
+ w += e;
+ d += e;
+ }
+ else
+#ifndef NOMEMCPY
+ if (w - d >= e) /* (this test assumes unsigned comparison) */
+ {
+ memcpy(slide + w, slide + d, e);
+ w += e;
+ d += e;
+ }
+ else /* do it slow to avoid memcpy() overlap */
+#endif /* !NOMEMCPY */
+ do {
+ slide[w++] = slide[d++];
+ } while (--e);
+ if (w == WSIZE)
+ {
+ flush(w);
+ w = u = 0;
+ }
+ } while (n);
+ }
+ }
+
+ /* flush out slide */
+ flush(w);
+ return pfile_in_zip_read_info->rest_read_compressed ? 5 : 0; /* should have read csize bytes */
+}
+
+
+
+int explode_nolit4(tl, td, bl, bd)
+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. */
+{
+ longint 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 ULONG 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 = pUnzip->pfile_in_zip_read->rest_read_uncompressed;
+ while (s > 0) /* do until ucsize bytes uncompressed */
+ {
+ NEEDBITS(1)
+ if (b & 1) /* then literal--get eight bits */
+ {
+ DUMPBITS(1)
+ s--;
+ NEEDBITS(8)
+ slide[w++] = (byte)b;
+ if (w == WSIZE)
+ {
+ flush(w);
+ 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 {
+ n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);
+ if (u && w <= d)
+ {
+ memset(slide + w, 0, e);
+ w += e;
+ d += e;
+ }
+ else
+#ifndef NOMEMCPY
+ if (w - d >= e) /* (this test assumes unsigned comparison) */
+ {
+ memcpy(slide + w, slide + d, e);
+ w += e;
+ d += e;
+ }
+ else /* do it slow to avoid memcpy() overlap */
+#endif /* !NOMEMCPY */
+ do {
+ slide[w++] = slide[d++];
+ } while (--e);
+ if (w == WSIZE)
+ {
+ flush(w);
+ w = u = 0;
+ }
+ } while (n);
+ }
+ }
+
+ /* flush out slide */
+ flush(w);
+ return pfile_in_zip_read_info->rest_read_compressed ? 5 : 0; /* should have read csize bytes */
+}
+
+
+
+int explode ()
+/* 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 */
+
+
+ /* 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 suprised to find out the 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 = pUnzip->pfile_in_zip_read->rest_read_compressed > 200000L ? 8 : 7;
+
+
+ /* With literal tree--minimum match length is 3 */
+ hufts = 0; /* initialze huft's malloc'ed */
+ if (pUnzip->cur_file_info.flag & 4)
+ {
+ bb = 9; /* base table size for literals */
+ if ((r = get_tree(l, 256)) != 0)
+ return r;
+ if ((r = huft_build(l, 256, 256, NULL, NULL, &tb, &bb)) != 0)
+ {
+ if (r == 1)
+ huft_free(tb);
+ return r;
+ }
+ if ((r = get_tree(l, 64)) != 0)
+ return r;
+ if ((r = huft_build(l, 64, 0, cplen3, extra, &tl, &bl)) != 0)
+ {
+ if (r == 1)
+ huft_free(tl);
+ huft_free(tb);
+ return r;
+ }
+ if ((r = get_tree(l, 64)) != 0)
+ return r;
+ if (pUnzip->cur_file_info.flag & 2) /* true if 8K */
+ {
+ if ((r = huft_build(l, 64, 0, cpdist8, extra, &td, &bd)) != 0)
+ {
+ if (r == 1)
+ huft_free(td);
+ huft_free(tl);
+ huft_free(tb);
+ return r;
+ }
+ r = explode_lit8(tb, tl, td, bb, bl, bd);
+ }
+ else /* else 4K */
+ {
+ if ((r = huft_build(l, 64, 0, cpdist4, extra, &td, &bd)) != 0)
+ {
+ if (r == 1)
+ huft_free(td);
+ huft_free(tl);
+ huft_free(tb);
+ return r;
+ }
+ r = explode_lit4(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(l, 64)) != 0)
+ return r;
+ if ((r = huft_build(l, 64, 0, cplen2, extra, &tl, &bl)) != 0)
+ {
+ if (r == 1)
+ huft_free(tl);
+ return r;
+ }
+ if ((r = get_tree(l, 64)) != 0)
+ return r;
+ if (pUnzip->cur_file_info.flag & 2) /* true if 8K */
+ {
+ if ((r = huft_build(l, 64, 0, cpdist8, extra, &td, &bd)) != 0)
+ {
+ if (r == 1)
+ huft_free(td);
+ huft_free(tl);
+ return r;
+ }
+ r = explode_nolit8(tl, td, bl, bd);
+ }
+ else /* else 4K */
+ {
+ if ((r = huft_build(l, 64, 0, cpdist4, extra, &td, &bd)) != 0)
+ {
+ if (r == 1)
+ huft_free(td);
+ huft_free(tl);
+ return r;
+ }
+ r = explode_nolit4(tl, td, bl, bd);
+ }
+ huft_free(td);
+ huft_free(tl);
+ }
+#ifdef DEBUG
+ fprintf(stderr, "<%u > ", hufts);
+#endif /* DEBUG */
+ return r;
+}
+
+
+int ReadByte(x)
+ UWORD *x;
+{
+ /*
+ * read a byte; return 8 if byte available, 0 if not
+ */
+
+ if (pfile_in_zip_read_info->stream.avail_in == 0)
+ {
+ unsigned int uReadThis = UNZ_BUFSIZE;
+
+ if (pfile_in_zip_read_info->rest_read_compressed <= 0)
+ return (0);
+
+ if (pfile_in_zip_read_info->rest_read_compressed < uReadThis)
+ uReadThis = (uInt) pfile_in_zip_read_info->rest_read_compressed;
+ if (uReadThis == 0)
+ return UNZ_EOF;
+ if (fseek (pfile_in_zip_read_info->file,
+ pfile_in_zip_read_info->pos_in_zipfile +
+ pfile_in_zip_read_info->byte_before_the_zipfile, SEEK_SET) != 0)
+ return UNZ_ERRNO;
+ if (fread (pfile_in_zip_read_info->read_buffer, uReadThis, 1,
+ pfile_in_zip_read_info->file) != 1)
+ return UNZ_ERRNO;
+ pfile_in_zip_read_info->pos_in_zipfile += uReadThis;
+
+ pfile_in_zip_read_info->rest_read_compressed -= uReadThis;
+
+ pfile_in_zip_read_info->stream.next_in =
+ (Bytef *) pfile_in_zip_read_info->read_buffer;
+ pfile_in_zip_read_info->stream.avail_in = (uInt) uReadThis;
+ }
+
+ *x = *pfile_in_zip_read_info->stream.next_in++;
+ pfile_in_zip_read_info->stream.avail_in--;
+
+ return 8;
+}
+
+/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
+#define BMAX 16 /* maximum bit length of any code (16 for explode) */
+#define N_MAX 288 /* maximum number of codes in any set */
+
+unsigned hufts; /* track memory usage */
+
+
+int huft_build(b, n, s, d, e, t, m)
+unsigned *b; /* code lengths in bits (all assumed <= BMAX) */
+unsigned n; /* number of codes (assumed <= N_MAX) */
+unsigned s; /* number of simple-valued codes (0..s-1) */
+ush *d; /* list of base values for non-simple codes */
+ush *e; /* list of extra bits for non-simple codes */
+struct huft **t; /* result: starting table */
+int *m; /* maximum lookup bits, returns actual */
+/* Given a list of code lengths and a maximum table size, make a set of
+ tables to decode that set of codes. Return zero on success, one if
+ the given code set is incomplete (the tables are still built in this
+ case), two if the input is invalid (all zero length codes or an
+ oversubscribed set of lengths), and three if not enough memory. */
+{
+ unsigned a; /* counter for codes of length k */
+ unsigned c[BMAX+1]; /* bit length count table */
+ unsigned f; /* i repeats in table every f entries */
+ int g; /* maximum code length */
+ int h; /* table level */
+ register unsigned i; /* counter, current code */
+ register unsigned j; /* counter */
+ register int k; /* number of bits in current code */
+ int l; /* bits per table (returned in m) */
+ register unsigned *p; /* pointer into c[], b[], or v[] */
+ register struct huft *q; /* points to current table */
+ struct huft r; /* table entry for structure assignment */
+ struct huft *u[BMAX]; /* table stack */
+ unsigned v[N_MAX]; /* values in order of bit length */
+ register int w; /* bits before this table == (l * h) */
+ unsigned x[BMAX+1]; /* bit offsets, then code stack */
+ unsigned *xp; /* pointer into x */
+ int y; /* number of dummy codes added */
+ unsigned z; /* number of entries in current table */
+
+
+ /* Generate counts for each bit length */
+ memset(c, 0, sizeof(c));
+ p = b; i = n;
+ do {
+ c[*p++]++; /* assume all entries <= BMAX */
+ } while (--i);
+ if (c[0] == n) /* null input--all zero length codes */
+ {
+ *t = (struct huft *)NULL;
+ *m = 0;
+ return 0;
+ }
+
+
+ /* Find minimum and maximum length, bound *m by those */
+ l = *m;
+ for (j = 1; j <= BMAX; j++)
+ if (c[j])
+ break;
+ k = j; /* minimum code length */
+ if ((unsigned)l < j)
+ l = j;
+ for (i = BMAX; i; i--)
+ if (c[i])
+ break;
+ g = i; /* maximum code length */
+ if ((unsigned)l > i)
+ l = i;
+ *m = l;
+
+
+ /* Adjust last length count to fill out codes, if needed */
+ for (y = 1 << j; j < i; j++, y <<= 1)
+ if ((y -= c[j]) < 0)
+ return 2; /* bad input: more codes than bits */
+ if ((y -= c[i]) < 0)
+ return 2;
+ c[i] += y;
+
+
+ /* Generate starting offsets into the value table for each length */
+ x[1] = j = 0;
+ p = c + 1; xp = x + 2;
+ while (--i) { /* note that i == g from above */
+ *xp++ = (j += *p++);
+ }
+
+
+ /* Make a table of values in order of bit lengths */
+ p = b; i = 0;
+ do {
+ if ((j = *p++) != 0)
+ v[x[j]++] = i;
+ } while (++i < n);
+
+
+ /* Generate the Huffman codes and for each, make the table entries */
+ x[0] = i = 0; /* first Huffman code is zero */
+ p = v; /* grab values in bit order */
+ h = -1; /* no tables yet--level -1 */
+ w = -l; /* bits decoded == (l * h) */
+ u[0] = (struct huft *)NULL; /* just to keep compilers happy */
+ q = (struct huft *)NULL; /* ditto */
+ z = 0; /* ditto */
+
+ /* go through the bit lengths (k already is bits in shortest code) */
+ for (; k <= g; k++)
+ {
+ a = c[k];
+ while (a--)
+ {
+ /* here i is the Huffman code of length k bits for value *p */
+ /* make tables up to required level */
+ while (k > w + l)
+ {
+ h++;
+ w += l; /* previous table always l bits */
+
+ /* compute minimum size table less than or equal to l bits */
+ z = (z = g - w) > (unsigned)l ? l : z; /* upper limit on table size */
+ if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
+ { /* too few codes for k-w bit table */
+ f -= a + 1; /* deduct codes from patterns left */
+ xp = c + k;
+ while (++j < z) /* try smaller tables up to z bits */
+ {
+ if ((f <<= 1) <= *++xp)
+ break; /* enough codes to use up j bits */
+ f -= *xp; /* else deduct codes from patterns */
+ }
+ }
+ z = 1 << j; /* table entries for j-bit table */
+
+ /* allocate and link in new table */
+ if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
+ (struct huft *)NULL)
+ {
+ if (h)
+ huft_free(u[0]);
+ return 3; /* not enough memory */
+ }
+ hufts += z + 1; /* track memory usage */
+ *t = q + 1; /* link to list for huft_free() */
+ *(t = &(q->v.t)) = (struct huft *)NULL;
+ u[h] = ++q; /* table starts after link */
+
+ /* connect to last table, if there is one */
+ if (h)
+ {
+ x[h] = i; /* save pattern for backing up */
+ r.b = (uch)l; /* bits to dump before this table */
+ r.e = (uch)(16 + j); /* bits in this table */
+ r.v.t = q; /* pointer to this table */
+ j = i >> (w - l); /* (get around Turbo C bug) */
+ u[h-1][j] = r; /* connect to last table */
+ }
+ }
+
+ /* set up table entry in r */
+ r.b = (uch)(k - w);
+ if (p >= v + n)
+ r.e = 99; /* out of values--invalid code */
+ else if (*p < s)
+ {
+ r.e = (uch)(*p < 256 ? 16 : 15); /* 256 is end-of-block code */
+ r.v.n = *p++; /* simple code is just the value */
+ }
+ else
+ {
+ r.e = (uch)e[*p - s]; /* non-simple--look up in lists */
+ r.v.n = d[*p++ - s];
+ }
+
+ /* fill code-like entries with r */
+ f = 1 << (k - w);
+ for (j = i >> w; j < z; j += f)
+ q[j] = r;
+
+ /* backwards increment the k-bit code i */
+ for (j = 1 << (k - 1); i & j; j >>= 1)
+ i ^= j;
+ i ^= j;
+
+ /* backup over finished tables */
+ while ((i & ((1 << w) - 1)) != x[h])
+ {
+ h--; /* don't need to update q */
+ w -= l;
+ }
+ }
+ }
+
+
+ /* Return true (1) if we were given an incomplete table */
+ return y != 0 && g != 1;
+}
+
+
+int huft_free(t)
+struct huft *t; /* table to free */
+/* Free the malloc'ed tables built by huft_build(), which makes a linked
+ list of the tables it made, with the links in a dummy first entry of
+ each table. */
+{
+ register struct huft *p, *q;
+
+
+ /* Go through linked list, freeing from the malloced (t[-1]) address. */
+ p = t;
+ while (p != (struct huft *)NULL)
+ {
+ q = (--p)->v.t;
+ free(p);
+ p = q;
+ }
+ return 0;
+}
+
+void flush(w)
+unsigned w; /* number of bytes to flush */
+/* Do the equivalent of OUTB for the bytes slide[0..w-1]. */
+{
+ memmove (pfile_in_zip_read_info->stream.next_out, slide, w);
+ pfile_in_zip_read_info->crc32 = crc32 (pfile_in_zip_read_info->crc32,
+ pfile_in_zip_read_info->stream.next_out,
+ w);
+ pfile_in_zip_read_info->stream.next_out += w;
+ pfile_in_zip_read_info->stream.avail_out -= w;
+ pfile_in_zip_read_info->stream.total_out += w;
+}
+
+void flush_stack(w)
+unsigned w; /* number of bytes to flush */
+/* Do the equivalent of OUTB for the bytes slide[0..w-1]. */
+{
+ memmove (pfile_in_zip_read_info->stream.next_out, stack, w);
+ pfile_in_zip_read_info->crc32 = crc32 (pfile_in_zip_read_info->crc32,
+ pfile_in_zip_read_info->stream.next_out,
+ w);
+ pfile_in_zip_read_info->stream.next_out += w;
+ pfile_in_zip_read_info->stream.avail_out -= w;
+ pfile_in_zip_read_info->stream.total_out += w;
+}
+
+/****************************/
+/* Function FillBitBuffer() */
+/****************************/
+
+int FillBitBuffer()
+{
+ /*
+ * Fill bitbuf, which is 32 bits. This function is only used by the
+ * READBIT and PEEKBIT macros (which are used by all of the uncompression
+ * routines).
+ */
+ UWORD temp;
+
+ zipeof = 1;
+ while (bits_left < 25 && ReadByte(&temp) == 8)
+ {
+ bitbuf |= (ULONG)temp << bits_left;
+ bits_left += 8;
+ zipeof = 0;
+ }
+ return 0;
+}
+