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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;
-}
-
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-25 15:48:44 +0000