1 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 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402
|
/* unlzh.c -- decompress files in SCO compress -H (LZH) format.
* The code in this file is directly derived from the public domain 'ar002'
* written by Haruhiko Okumura.
*/
#ifdef RCSID
static char rcsid[] = "$Id: unlzh.c,v 1.2 1993/06/24 10:59:01 jloup Exp $";
#endif
#include <config.h>
#include <stdio.h>
#include "tailor.h"
#include "gzip.h"
#include "lzw.h" /* just for consistency checking */
/* decode.c */
local unsigned decode OF((unsigned count, uch buffer[]));
local void decode_start OF((void));
/* huf.c */
local void huf_decode_start OF((void));
local unsigned decode_c OF((void));
local unsigned decode_p OF((void));
local void read_pt_len OF((int nn, int nbit, int i_special));
local void read_c_len OF((void));
/* io.c */
local void fillbuf OF((int n));
local unsigned getbits OF((int n));
local void init_getbits OF((void));
/* maketbl.c */
local void make_table OF((int nchar, uch bitlen[],
int tablebits, ush table[]));
#define DICBIT 13 /* 12(-lh4-) or 13(-lh5-) */
#define DICSIZ ((unsigned) 1 << DICBIT)
#ifndef CHAR_BIT
# define CHAR_BIT 8
#endif
#ifndef UCHAR_MAX
# define UCHAR_MAX 255
#endif
#define BITBUFSIZ (CHAR_BIT * 2 * sizeof(char))
/* Do not use CHAR_BIT * sizeof(bitbuf), does not work on machines
* for which short is not on 16 bits (Cray).
*/
/* encode.c and decode.c */
#define MAXMATCH 256 /* formerly F (not more than UCHAR_MAX + 1) */
#define THRESHOLD 3 /* choose optimal value */
/* huf.c */
#define NC (UCHAR_MAX + MAXMATCH + 2 - THRESHOLD)
/* alphabet = {0, 1, 2, ..., NC - 1} */
#define CBIT 9 /* $\lfloor \log_2 NC \rfloor + 1$ */
#define CODE_BIT 16 /* codeword length */
#define NP (DICBIT + 1)
#define NT (CODE_BIT + 3)
#define PBIT 4 /* smallest integer such that (1U << PBIT) > NP */
#define TBIT 5 /* smallest integer such that (1U << TBIT) > NT */
#if NT > NP
# define NPT NT
#else
# define NPT NP
#endif
/* local ush left[2 * NC - 1]; */
/* local ush right[2 * NC - 1]; */
#define left prev
#define right head
#if NC > (1<<(BITS-2))
error cannot overlay left+right and prev
#endif
/* local uch c_len[NC]; */
#define c_len outbuf
#if NC > OUTBUFSIZ
error cannot overlay c_len and outbuf
#endif
local uch pt_len[NPT];
local unsigned blocksize;
local ush pt_table[256];
/* local ush c_table[4096]; */
#define c_table d_buf
#if (DIST_BUFSIZE-1) < 4095
error cannot overlay c_table and d_buf
#endif
/***********************************************************
io.c -- input/output
***********************************************************/
local ush bitbuf;
local unsigned subbitbuf;
local int bitcount;
local void fillbuf(n) /* Shift bitbuf n bits left, read n bits */
int n;
{
bitbuf <<= n;
while (n > bitcount) {
bitbuf |= subbitbuf << (n -= bitcount);
subbitbuf = (unsigned)try_byte();
if ((int)subbitbuf == EOF) subbitbuf = 0;
bitcount = CHAR_BIT;
}
bitbuf |= subbitbuf >> (bitcount -= n);
}
local unsigned getbits(n)
int n;
{
unsigned x;
x = bitbuf >> (BITBUFSIZ - n); fillbuf(n);
return x;
}
local void init_getbits()
{
bitbuf = 0; subbitbuf = 0; bitcount = 0;
fillbuf(BITBUFSIZ);
}
/***********************************************************
maketbl.c -- make table for decoding
***********************************************************/
local void make_table(nchar, bitlen, tablebits, table)
int nchar;
uch bitlen[];
int tablebits;
ush table[];
{
ush count[17], weight[17], start[18], *p;
unsigned i, k, len, ch, jutbits, avail, nextcode, mask;
for (i = 1; i <= 16; i++) count[i] = 0;
for (i = 0; i < (unsigned)nchar; i++) count[bitlen[i]]++;
start[1] = 0;
for (i = 1; i <= 16; i++)
start[i + 1] = start[i] + (count[i] << (16 - i));
if ((start[17] & 0xffff) != 0)
error("Bad table\n");
jutbits = 16 - tablebits;
for (i = 1; i <= (unsigned)tablebits; i++) {
start[i] >>= jutbits;
weight[i] = (unsigned) 1 << (tablebits - i);
}
while (i <= 16) {
weight[i] = (unsigned) 1 << (16 - i);
i++;
}
i = start[tablebits + 1] >> jutbits;
if (i != 0) {
k = 1 << tablebits;
while (i != k) table[i++] = 0;
}
avail = nchar;
mask = (unsigned) 1 << (15 - tablebits);
for (ch = 0; ch < (unsigned)nchar; ch++) {
if ((len = bitlen[ch]) == 0) continue;
nextcode = start[len] + weight[len];
if (len <= (unsigned)tablebits) {
for (i = start[len]; i < nextcode; i++) table[i] = ch;
} else {
k = start[len];
p = &table[k >> jutbits];
i = len - tablebits;
while (i != 0) {
if (*p == 0) {
right[avail] = left[avail] = 0;
*p = avail++;
}
if (k & mask) p = &right[*p];
else p = &left[*p];
k <<= 1; i--;
}
*p = ch;
}
start[len] = nextcode;
}
}
/***********************************************************
huf.c -- static Huffman
***********************************************************/
local void read_pt_len(nn, nbit, i_special)
int nn;
int nbit;
int i_special;
{
int i, c, n;
unsigned mask;
n = getbits(nbit);
if (n == 0) {
c = getbits(nbit);
for (i = 0; i < nn; i++) pt_len[i] = 0;
for (i = 0; i < 256; i++) pt_table[i] = c;
} else {
i = 0;
while (i < n) {
c = bitbuf >> (BITBUFSIZ - 3);
if (c == 7) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 3);
while (mask & bitbuf) { mask >>= 1; c++; }
}
fillbuf((c < 7) ? 3 : c - 3);
pt_len[i++] = c;
if (i == i_special) {
c = getbits(2);
while (--c >= 0) pt_len[i++] = 0;
}
}
while (i < nn) pt_len[i++] = 0;
make_table(nn, pt_len, 8, pt_table);
}
}
local void read_c_len()
{
int i, c, n;
unsigned mask;
n = getbits(CBIT);
if (n == 0) {
c = getbits(CBIT);
for (i = 0; i < NC; i++) c_len[i] = 0;
for (i = 0; i < 4096; i++) c_table[i] = c;
} else {
i = 0;
while (i < n) {
c = pt_table[bitbuf >> (BITBUFSIZ - 8)];
if (c >= NT) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 8);
do {
if (bitbuf & mask) c = right[c];
else c = left [c];
mask >>= 1;
} while (c >= NT);
}
fillbuf((int) pt_len[c]);
if (c <= 2) {
if (c == 0) c = 1;
else if (c == 1) c = getbits(4) + 3;
else c = getbits(CBIT) + 20;
while (--c >= 0) c_len[i++] = 0;
} else c_len[i++] = c - 2;
}
while (i < NC) c_len[i++] = 0;
make_table(NC, c_len, 12, c_table);
}
}
local unsigned decode_c()
{
unsigned j, mask;
if (blocksize == 0) {
blocksize = getbits(16);
if (blocksize == 0) {
return NC; /* end of file */
}
read_pt_len(NT, TBIT, 3);
read_c_len();
read_pt_len(NP, PBIT, -1);
}
blocksize--;
j = c_table[bitbuf >> (BITBUFSIZ - 12)];
if (j >= NC) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 12);
do {
if (bitbuf & mask) j = right[j];
else j = left [j];
mask >>= 1;
} while (j >= NC);
}
fillbuf((int) c_len[j]);
return j;
}
local unsigned decode_p()
{
unsigned j, mask;
j = pt_table[bitbuf >> (BITBUFSIZ - 8)];
if (j >= NP) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 8);
do {
if (bitbuf & mask) j = right[j];
else j = left [j];
mask >>= 1;
} while (j >= NP);
}
fillbuf((int) pt_len[j]);
if (j != 0) j = ((unsigned) 1 << (j - 1)) + getbits((int) (j - 1));
return j;
}
local void huf_decode_start()
{
init_getbits(); blocksize = 0;
}
/***********************************************************
decode.c
***********************************************************/
local int j; /* remaining bytes to copy */
local int done; /* set at end of input */
local void decode_start()
{
huf_decode_start();
j = 0;
done = 0;
}
/* Decode the input and return the number of decoded bytes put in buffer
*/
local unsigned decode(count, buffer)
unsigned count;
uch buffer[];
/* The calling function must keep the number of
bytes to be processed. This function decodes
either 'count' bytes or 'DICSIZ' bytes, whichever
is smaller, into the array 'buffer[]' of size
'DICSIZ' or more.
Call decode_start() once for each new file
before calling this function.
*/
{
local unsigned i;
unsigned r, c;
r = 0;
while (--j >= 0) {
buffer[r] = buffer[i];
i = (i + 1) & (DICSIZ - 1);
if (++r == count) return r;
}
for ( ; ; ) {
c = decode_c();
if (c == NC) {
done = 1;
return r;
}
if (c <= UCHAR_MAX) {
buffer[r] = c;
if (++r == count) return r;
} else {
j = c - (UCHAR_MAX + 1 - THRESHOLD);
i = (r - decode_p() - 1) & (DICSIZ - 1);
while (--j >= 0) {
buffer[r] = buffer[i];
i = (i + 1) & (DICSIZ - 1);
if (++r == count) return r;
}
}
}
}
/* ===========================================================================
* Unlzh in to out. Return OK or ERROR.
*/
int unlzh(in, out)
int in;
int out;
{
unsigned n;
ifd = in;
ofd = out;
decode_start();
while (!done) {
n = decode((unsigned) DICSIZ, window);
if (!test && n > 0) {
write_buf(out, (char*)window, n);
}
}
return OK;
}
|