mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-13 10:02:38 +00:00
378 lines
8.6 KiB
C
378 lines
8.6 KiB
C
/* unlzw.c -- decompress files in LZW format.
|
|
* The code in this file is directly derived from the public domain 'compress'
|
|
* written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
|
|
* Ken Turkowski, Dave Mack and Peter Jannesen.
|
|
*
|
|
* This is a temporary version which will be rewritten in some future version
|
|
* to accommodate in-memory decompression.
|
|
*/
|
|
|
|
#ifdef RCSID
|
|
static char rcsid[] = "$Id: unlzw.c,v 1.3 1993/10/14 00:33:17 nate Exp $";
|
|
#endif
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include "tailor.h"
|
|
|
|
#ifdef HAVE_UNISTD_H
|
|
# include <unistd.h>
|
|
#endif
|
|
#ifndef NO_FCNTL_H
|
|
# include <fcntl.h>
|
|
#endif
|
|
|
|
#include "gzip.h"
|
|
#include "lzw.h"
|
|
|
|
typedef unsigned char char_type;
|
|
typedef long code_int;
|
|
typedef unsigned long count_int;
|
|
typedef unsigned short count_short;
|
|
typedef unsigned long cmp_code_int;
|
|
|
|
#define MAXCODE(n) (1L << (n))
|
|
|
|
#ifndef REGISTERS
|
|
# define REGISTERS 2
|
|
#endif
|
|
#define REG1
|
|
#define REG2
|
|
#define REG3
|
|
#define REG4
|
|
#define REG5
|
|
#define REG6
|
|
#define REG7
|
|
#define REG8
|
|
#define REG9
|
|
#define REG10
|
|
#define REG11
|
|
#define REG12
|
|
#define REG13
|
|
#define REG14
|
|
#define REG15
|
|
#define REG16
|
|
#if REGISTERS >= 1
|
|
# undef REG1
|
|
# define REG1 register
|
|
#endif
|
|
#if REGISTERS >= 2
|
|
# undef REG2
|
|
# define REG2 register
|
|
#endif
|
|
#if REGISTERS >= 3
|
|
# undef REG3
|
|
# define REG3 register
|
|
#endif
|
|
#if REGISTERS >= 4
|
|
# undef REG4
|
|
# define REG4 register
|
|
#endif
|
|
#if REGISTERS >= 5
|
|
# undef REG5
|
|
# define REG5 register
|
|
#endif
|
|
#if REGISTERS >= 6
|
|
# undef REG6
|
|
# define REG6 register
|
|
#endif
|
|
#if REGISTERS >= 7
|
|
# undef REG7
|
|
# define REG7 register
|
|
#endif
|
|
#if REGISTERS >= 8
|
|
# undef REG8
|
|
# define REG8 register
|
|
#endif
|
|
#if REGISTERS >= 9
|
|
# undef REG9
|
|
# define REG9 register
|
|
#endif
|
|
#if REGISTERS >= 10
|
|
# undef REG10
|
|
# define REG10 register
|
|
#endif
|
|
#if REGISTERS >= 11
|
|
# undef REG11
|
|
# define REG11 register
|
|
#endif
|
|
#if REGISTERS >= 12
|
|
# undef REG12
|
|
# define REG12 register
|
|
#endif
|
|
#if REGISTERS >= 13
|
|
# undef REG13
|
|
# define REG13 register
|
|
#endif
|
|
#if REGISTERS >= 14
|
|
# undef REG14
|
|
# define REG14 register
|
|
#endif
|
|
#if REGISTERS >= 15
|
|
# undef REG15
|
|
# define REG15 register
|
|
#endif
|
|
#if REGISTERS >= 16
|
|
# undef REG16
|
|
# define REG16 register
|
|
#endif
|
|
|
|
#ifndef BYTEORDER
|
|
# define BYTEORDER 0000
|
|
#endif
|
|
|
|
#ifndef NOALLIGN
|
|
# define NOALLIGN 0
|
|
#endif
|
|
|
|
|
|
union bytes {
|
|
long word;
|
|
struct {
|
|
#if BYTEORDER == 4321
|
|
char_type b1;
|
|
char_type b2;
|
|
char_type b3;
|
|
char_type b4;
|
|
#else
|
|
#if BYTEORDER == 1234
|
|
char_type b4;
|
|
char_type b3;
|
|
char_type b2;
|
|
char_type b1;
|
|
#else
|
|
# undef BYTEORDER
|
|
int dummy;
|
|
#endif
|
|
#endif
|
|
} bytes;
|
|
};
|
|
|
|
#if BYTEORDER == 4321 && NOALLIGN == 1
|
|
# define input(b,o,c,n,m){ \
|
|
(c) = (*(long *)(&(b)[(o)>>3])>>((o)&0x7))&(m); \
|
|
(o) += (n); \
|
|
}
|
|
#else
|
|
# define input(b,o,c,n,m){ \
|
|
REG1 char_type *p = &(b)[(o)>>3]; \
|
|
(c) = ((((long)(p[0]))|((long)(p[1])<<8)| \
|
|
((long)(p[2])<<16))>>((o)&0x7))&(m); \
|
|
(o) += (n); \
|
|
}
|
|
#endif
|
|
|
|
#ifndef MAXSEG_64K
|
|
/* DECLARE(ush, tab_prefix, (1<<BITS)); -- prefix code */
|
|
# define tab_prefixof(i) tab_prefix[i]
|
|
# define clear_tab_prefixof() memzero(tab_prefix, 256);
|
|
#else
|
|
/* DECLARE(ush, tab_prefix0, (1<<(BITS-1)); -- prefix for even codes */
|
|
/* DECLARE(ush, tab_prefix1, (1<<(BITS-1)); -- prefix for odd codes */
|
|
ush *tab_prefix[2];
|
|
# define tab_prefixof(i) tab_prefix[(i)&1][(i)>>1]
|
|
# define clear_tab_prefixof() \
|
|
memzero(tab_prefix0, 128), \
|
|
memzero(tab_prefix1, 128);
|
|
#endif
|
|
#define de_stack ((char_type *)(&d_buf[DIST_BUFSIZE-1]))
|
|
#define tab_suffixof(i) tab_suffix[i]
|
|
|
|
int block_mode = BLOCK_MODE; /* block compress mode -C compatible with 2.0 */
|
|
|
|
/* ============================================================================
|
|
* Decompress in to out. This routine adapts to the codes in the
|
|
* file building the "string" table on-the-fly; requiring no table to
|
|
* be stored in the compressed file.
|
|
* IN assertions: the buffer inbuf contains already the beginning of
|
|
* the compressed data, from offsets iptr to insize-1 included.
|
|
* The magic header has already been checked and skipped.
|
|
* bytes_in and bytes_out have been initialized.
|
|
*/
|
|
int unlzw(in, out)
|
|
int in, out; /* input and output file descriptors */
|
|
{
|
|
REG2 char_type *stackp;
|
|
REG3 code_int code;
|
|
REG4 int finchar;
|
|
REG5 code_int oldcode;
|
|
REG6 code_int incode;
|
|
REG7 long inbits;
|
|
REG8 long posbits;
|
|
REG9 int outpos;
|
|
/* REG10 int insize; (global) */
|
|
REG11 unsigned bitmask;
|
|
REG12 code_int free_ent;
|
|
REG13 code_int maxcode;
|
|
REG14 code_int maxmaxcode;
|
|
REG15 int n_bits;
|
|
REG16 int rsize;
|
|
|
|
#ifdef MAXSEG_64K
|
|
tab_prefix[0] = tab_prefix0;
|
|
tab_prefix[1] = tab_prefix1;
|
|
#endif
|
|
maxbits = get_byte();
|
|
block_mode = maxbits & BLOCK_MODE;
|
|
if ((maxbits & LZW_RESERVED) != 0) {
|
|
WARN((stderr, "\n%s: %s: warning, unknown flags 0x%x\n",
|
|
progname, ifname, maxbits & LZW_RESERVED));
|
|
}
|
|
maxbits &= BIT_MASK;
|
|
maxmaxcode = MAXCODE(maxbits);
|
|
|
|
if (maxbits > BITS) {
|
|
fprintf(stderr,
|
|
"\n%s: %s: compressed with %d bits, can only handle %d bits\n",
|
|
progname, ifname, maxbits, BITS);
|
|
exit_code = ERROR;
|
|
return ERROR;
|
|
}
|
|
rsize = insize;
|
|
maxcode = MAXCODE(n_bits = INIT_BITS)-1;
|
|
bitmask = (1<<n_bits)-1;
|
|
oldcode = -1;
|
|
finchar = 0;
|
|
outpos = 0;
|
|
posbits = inptr<<3;
|
|
|
|
free_ent = ((block_mode) ? FIRST : 256);
|
|
|
|
clear_tab_prefixof(); /* Initialize the first 256 entries in the table. */
|
|
|
|
for (code = 255 ; code >= 0 ; --code) {
|
|
tab_suffixof(code) = (char_type)code;
|
|
}
|
|
do {
|
|
REG1 int i;
|
|
int e;
|
|
int o;
|
|
|
|
resetbuf:
|
|
e = insize-(o = (posbits>>3));
|
|
|
|
for (i = 0 ; i < e ; ++i) {
|
|
inbuf[i] = inbuf[i+o];
|
|
}
|
|
insize = e;
|
|
posbits = 0;
|
|
|
|
if (insize < INBUF_EXTRA) {
|
|
if ((rsize = read(in, (char*)inbuf+insize, INBUFSIZ)) == EOF) {
|
|
read_error();
|
|
}
|
|
insize += rsize;
|
|
bytes_in += (ulg)rsize;
|
|
}
|
|
inbits = ((rsize != 0) ? ((long)insize - insize%n_bits)<<3 :
|
|
((long)insize<<3)-(n_bits-1));
|
|
|
|
while (inbits > posbits) {
|
|
if (free_ent > maxcode) {
|
|
posbits = ((posbits-1) +
|
|
((n_bits<<3)-(posbits-1+(n_bits<<3))%(n_bits<<3)));
|
|
++n_bits;
|
|
if (n_bits == maxbits) {
|
|
maxcode = maxmaxcode;
|
|
} else {
|
|
maxcode = MAXCODE(n_bits)-1;
|
|
}
|
|
bitmask = (1<<n_bits)-1;
|
|
goto resetbuf;
|
|
}
|
|
input(inbuf,posbits,code,n_bits,bitmask);
|
|
Tracev((stderr, "%d ", code));
|
|
|
|
if (oldcode == -1) {
|
|
if (code >= 256) error("corrupt input.");
|
|
outbuf[outpos++] = (char_type)(finchar = (int)(oldcode=code));
|
|
continue;
|
|
}
|
|
if (code == CLEAR && block_mode) {
|
|
clear_tab_prefixof();
|
|
free_ent = FIRST - 1;
|
|
posbits = ((posbits-1) +
|
|
((n_bits<<3)-(posbits-1+(n_bits<<3))%(n_bits<<3)));
|
|
maxcode = MAXCODE(n_bits = INIT_BITS)-1;
|
|
bitmask = (1<<n_bits)-1;
|
|
goto resetbuf;
|
|
}
|
|
incode = code;
|
|
stackp = de_stack;
|
|
|
|
if (code >= free_ent) { /* Special case for KwKwK string. */
|
|
if (code > free_ent) {
|
|
#ifdef DEBUG
|
|
char_type *p;
|
|
|
|
posbits -= n_bits;
|
|
p = &inbuf[posbits>>3];
|
|
fprintf(stderr,
|
|
"code:%ld free_ent:%ld n_bits:%d insize:%u\n",
|
|
code, free_ent, n_bits, insize);
|
|
fprintf(stderr,
|
|
"posbits:%ld inbuf:%02X %02X %02X %02X %02X\n",
|
|
posbits, p[-1],p[0],p[1],p[2],p[3]);
|
|
#endif
|
|
if (!test && outpos > 0) {
|
|
write_buf(out, (char*)outbuf, outpos);
|
|
bytes_out += (ulg)outpos;
|
|
}
|
|
error(to_stdout ? "corrupt input." :
|
|
"corrupt input. Use zcat to recover some data.");
|
|
}
|
|
*--stackp = (char_type)finchar;
|
|
code = oldcode;
|
|
}
|
|
|
|
while ((cmp_code_int)code >= (cmp_code_int)256) {
|
|
/* Generate output characters in reverse order */
|
|
*--stackp = tab_suffixof(code);
|
|
code = tab_prefixof(code);
|
|
}
|
|
*--stackp = (char_type)(finchar = tab_suffixof(code));
|
|
|
|
/* And put them out in forward order */
|
|
{
|
|
REG1 int i;
|
|
|
|
if (outpos+(i = (de_stack-stackp)) >= OUTBUFSIZ) {
|
|
do {
|
|
if (i > OUTBUFSIZ-outpos) i = OUTBUFSIZ-outpos;
|
|
|
|
if (i > 0) {
|
|
memcpy(outbuf+outpos, stackp, i);
|
|
outpos += i;
|
|
}
|
|
if (outpos >= OUTBUFSIZ) {
|
|
if (!test) {
|
|
write_buf(out, (char*)outbuf, outpos);
|
|
bytes_out += (ulg)outpos;
|
|
}
|
|
outpos = 0;
|
|
}
|
|
stackp+= i;
|
|
} while ((i = (de_stack-stackp)) > 0);
|
|
} else {
|
|
memcpy(outbuf+outpos, stackp, i);
|
|
outpos += i;
|
|
}
|
|
}
|
|
|
|
if ((code = free_ent) < maxmaxcode) { /* Generate the new entry. */
|
|
|
|
tab_prefixof(code) = (unsigned short)oldcode;
|
|
tab_suffixof(code) = (char_type)finchar;
|
|
free_ent = code+1;
|
|
}
|
|
oldcode = incode; /* Remember previous code. */
|
|
}
|
|
} while (rsize != 0);
|
|
|
|
if (!test && outpos > 0) {
|
|
write_buf(out, (char*)outbuf, outpos);
|
|
bytes_out += (ulg)outpos;
|
|
}
|
|
return OK;
|
|
}
|