| 1 |
/* lzo1x_d.ch -- implementation of the LZO1X decompression algorithm
|
| 2 |
|
| 3 |
This file is part of the LZO real-time data compression library.
|
| 4 |
|
| 5 |
Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
|
| 6 |
Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
|
| 7 |
Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
|
| 8 |
Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
|
| 9 |
Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
|
| 10 |
Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
|
| 11 |
Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
|
| 12 |
Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
|
| 13 |
Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
|
| 14 |
Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
|
| 15 |
Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
|
| 16 |
Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
|
| 17 |
Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer
|
| 18 |
All Rights Reserved.
|
| 19 |
|
| 20 |
The LZO library is free software; you can redistribute it and/or
|
| 21 |
modify it under the terms of the GNU General Public License as
|
| 22 |
published by the Free Software Foundation; either version 2 of
|
| 23 |
the License, or (at your option) any later version.
|
| 24 |
|
| 25 |
The LZO library is distributed in the hope that it will be useful,
|
| 26 |
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
| 27 |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
| 28 |
GNU General Public License for more details.
|
| 29 |
|
| 30 |
You should have received a copy of the GNU General Public License
|
| 31 |
along with the LZO library; see the file COPYING.
|
| 32 |
If not, write to the Free Software Foundation, Inc.,
|
| 33 |
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
| 34 |
|
| 35 |
Markus F.X.J. Oberhumer
|
| 36 |
<markus@oberhumer.com>
|
| 37 |
http://www.oberhumer.com/opensource/lzo/
|
| 38 |
*/
|
| 39 |
|
| 40 |
|
| 41 |
#include "lzo1_d.ch"
|
| 42 |
|
| 43 |
|
| 44 |
#undef __COPY4
|
| 45 |
#define __COPY4(dst,src) * (lzo_uint32p)(dst) = * (const lzo_uint32p)(src)
|
| 46 |
|
| 47 |
#undef COPY4
|
| 48 |
#if defined(LZO_UNALIGNED_OK_4)
|
| 49 |
# define COPY4(dst,src) __COPY4(dst,src)
|
| 50 |
#elif defined(LZO_ALIGNED_OK_4)
|
| 51 |
# define COPY4(dst,src) __COPY4((lzo_uintptr_t)(dst),(lzo_uintptr_t)(src))
|
| 52 |
#endif
|
| 53 |
|
| 54 |
|
| 55 |
/***********************************************************************
|
| 56 |
// decompress a block of data.
|
| 57 |
************************************************************************/
|
| 58 |
|
| 59 |
#if defined(DO_DECOMPRESS)
|
| 60 |
LZO_PUBLIC(int)
|
| 61 |
DO_DECOMPRESS ( const lzo_bytep in , lzo_uint in_len,
|
| 62 |
lzo_bytep out, lzo_uintp out_len,
|
| 63 |
lzo_voidp wrkmem )
|
| 64 |
#endif
|
| 65 |
{
|
| 66 |
register lzo_bytep op;
|
| 67 |
register const lzo_bytep ip;
|
| 68 |
register lzo_uint t;
|
| 69 |
#if defined(COPY_DICT)
|
| 70 |
lzo_uint m_off;
|
| 71 |
const lzo_bytep dict_end;
|
| 72 |
#else
|
| 73 |
register const lzo_bytep m_pos;
|
| 74 |
#endif
|
| 75 |
|
| 76 |
const lzo_bytep const ip_end = in + in_len;
|
| 77 |
#if defined(HAVE_ANY_OP)
|
| 78 |
lzo_bytep const op_end = out + *out_len;
|
| 79 |
#endif
|
| 80 |
#if defined(LZO1Z)
|
| 81 |
lzo_uint last_m_off = 0;
|
| 82 |
#endif
|
| 83 |
|
| 84 |
LZO_UNUSED(wrkmem);
|
| 85 |
|
| 86 |
#if defined(COPY_DICT)
|
| 87 |
if (dict)
|
| 88 |
{
|
| 89 |
if (dict_len > M4_MAX_OFFSET)
|
| 90 |
{
|
| 91 |
dict += dict_len - M4_MAX_OFFSET;
|
| 92 |
dict_len = M4_MAX_OFFSET;
|
| 93 |
}
|
| 94 |
dict_end = dict + dict_len;
|
| 95 |
}
|
| 96 |
else
|
| 97 |
{
|
| 98 |
dict_len = 0;
|
| 99 |
dict_end = NULL;
|
| 100 |
}
|
| 101 |
#endif /* COPY_DICT */
|
| 102 |
|
| 103 |
*out_len = 0;
|
| 104 |
|
| 105 |
op = out;
|
| 106 |
ip = in;
|
| 107 |
|
| 108 |
if (*ip > 17)
|
| 109 |
{
|
| 110 |
t = *ip++ - 17;
|
| 111 |
if (t < 4)
|
| 112 |
goto match_next;
|
| 113 |
assert(t > 0); NEED_OP(t); NEED_IP(t+1);
|
| 114 |
do *op++ = *ip++; while (--t > 0);
|
| 115 |
goto first_literal_run;
|
| 116 |
}
|
| 117 |
|
| 118 |
while (TEST_IP && TEST_OP)
|
| 119 |
{
|
| 120 |
t = *ip++;
|
| 121 |
if (t >= 16)
|
| 122 |
goto match;
|
| 123 |
/* a literal run */
|
| 124 |
if (t == 0)
|
| 125 |
{
|
| 126 |
NEED_IP(1);
|
| 127 |
while (*ip == 0)
|
| 128 |
{
|
| 129 |
t += 255;
|
| 130 |
ip++;
|
| 131 |
NEED_IP(1);
|
| 132 |
}
|
| 133 |
t += 15 + *ip++;
|
| 134 |
}
|
| 135 |
/* copy literals */
|
| 136 |
assert(t > 0); NEED_OP(t+3); NEED_IP(t+4);
|
| 137 |
#if defined(LZO_UNALIGNED_OK_4) || defined(LZO_ALIGNED_OK_4)
|
| 138 |
#if !defined(LZO_UNALIGNED_OK_4)
|
| 139 |
if (PTR_ALIGNED2_4(op,ip))
|
| 140 |
{
|
| 141 |
#endif
|
| 142 |
COPY4(op,ip);
|
| 143 |
op += 4; ip += 4;
|
| 144 |
if (--t > 0)
|
| 145 |
{
|
| 146 |
if (t >= 4)
|
| 147 |
{
|
| 148 |
do {
|
| 149 |
COPY4(op,ip);
|
| 150 |
op += 4; ip += 4; t -= 4;
|
| 151 |
} while (t >= 4);
|
| 152 |
if (t > 0) do *op++ = *ip++; while (--t > 0);
|
| 153 |
}
|
| 154 |
else
|
| 155 |
do *op++ = *ip++; while (--t > 0);
|
| 156 |
}
|
| 157 |
#if !defined(LZO_UNALIGNED_OK_4)
|
| 158 |
}
|
| 159 |
else
|
| 160 |
#endif
|
| 161 |
#endif
|
| 162 |
#if !defined(LZO_UNALIGNED_OK_4)
|
| 163 |
{
|
| 164 |
*op++ = *ip++; *op++ = *ip++; *op++ = *ip++;
|
| 165 |
do *op++ = *ip++; while (--t > 0);
|
| 166 |
}
|
| 167 |
#endif
|
| 168 |
|
| 169 |
|
| 170 |
first_literal_run:
|
| 171 |
|
| 172 |
|
| 173 |
t = *ip++;
|
| 174 |
if (t >= 16)
|
| 175 |
goto match;
|
| 176 |
#if defined(COPY_DICT)
|
| 177 |
#if defined(LZO1Z)
|
| 178 |
m_off = (1 + M2_MAX_OFFSET) + (t << 6) + (*ip++ >> 2);
|
| 179 |
last_m_off = m_off;
|
| 180 |
#else
|
| 181 |
m_off = (1 + M2_MAX_OFFSET) + (t >> 2) + (*ip++ << 2);
|
| 182 |
#endif
|
| 183 |
NEED_OP(3);
|
| 184 |
t = 3; COPY_DICT(t,m_off)
|
| 185 |
#else /* !COPY_DICT */
|
| 186 |
#if defined(LZO1Z)
|
| 187 |
t = (1 + M2_MAX_OFFSET) + (t << 6) + (*ip++ >> 2);
|
| 188 |
m_pos = op - t;
|
| 189 |
last_m_off = t;
|
| 190 |
#else
|
| 191 |
m_pos = op - (1 + M2_MAX_OFFSET);
|
| 192 |
m_pos -= t >> 2;
|
| 193 |
m_pos -= *ip++ << 2;
|
| 194 |
#endif
|
| 195 |
TEST_LB(m_pos); NEED_OP(3);
|
| 196 |
*op++ = *m_pos++; *op++ = *m_pos++; *op++ = *m_pos;
|
| 197 |
#endif /* COPY_DICT */
|
| 198 |
goto match_done;
|
| 199 |
|
| 200 |
|
| 201 |
/* handle matches */
|
| 202 |
do {
|
| 203 |
match:
|
| 204 |
if (t >= 64) /* a M2 match */
|
| 205 |
{
|
| 206 |
#if defined(COPY_DICT)
|
| 207 |
#if defined(LZO1X)
|
| 208 |
m_off = 1 + ((t >> 2) & 7) + (*ip++ << 3);
|
| 209 |
t = (t >> 5) - 1;
|
| 210 |
#elif defined(LZO1Y)
|
| 211 |
m_off = 1 + ((t >> 2) & 3) + (*ip++ << 2);
|
| 212 |
t = (t >> 4) - 3;
|
| 213 |
#elif defined(LZO1Z)
|
| 214 |
m_off = t & 0x1f;
|
| 215 |
if (m_off >= 0x1c)
|
| 216 |
m_off = last_m_off;
|
| 217 |
else
|
| 218 |
{
|
| 219 |
m_off = 1 + (m_off << 6) + (*ip++ >> 2);
|
| 220 |
last_m_off = m_off;
|
| 221 |
}
|
| 222 |
t = (t >> 5) - 1;
|
| 223 |
#endif
|
| 224 |
#else /* !COPY_DICT */
|
| 225 |
#if defined(LZO1X)
|
| 226 |
m_pos = op - 1;
|
| 227 |
m_pos -= (t >> 2) & 7;
|
| 228 |
m_pos -= *ip++ << 3;
|
| 229 |
t = (t >> 5) - 1;
|
| 230 |
#elif defined(LZO1Y)
|
| 231 |
m_pos = op - 1;
|
| 232 |
m_pos -= (t >> 2) & 3;
|
| 233 |
m_pos -= *ip++ << 2;
|
| 234 |
t = (t >> 4) - 3;
|
| 235 |
#elif defined(LZO1Z)
|
| 236 |
{
|
| 237 |
lzo_uint off = t & 0x1f;
|
| 238 |
m_pos = op;
|
| 239 |
if (off >= 0x1c)
|
| 240 |
{
|
| 241 |
assert(last_m_off > 0);
|
| 242 |
m_pos -= last_m_off;
|
| 243 |
}
|
| 244 |
else
|
| 245 |
{
|
| 246 |
off = 1 + (off << 6) + (*ip++ >> 2);
|
| 247 |
m_pos -= off;
|
| 248 |
last_m_off = off;
|
| 249 |
}
|
| 250 |
}
|
| 251 |
t = (t >> 5) - 1;
|
| 252 |
#endif
|
| 253 |
TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1);
|
| 254 |
goto copy_match;
|
| 255 |
#endif /* COPY_DICT */
|
| 256 |
}
|
| 257 |
else if (t >= 32) /* a M3 match */
|
| 258 |
{
|
| 259 |
t &= 31;
|
| 260 |
if (t == 0)
|
| 261 |
{
|
| 262 |
NEED_IP(1);
|
| 263 |
while (*ip == 0)
|
| 264 |
{
|
| 265 |
t += 255;
|
| 266 |
ip++;
|
| 267 |
NEED_IP(1);
|
| 268 |
}
|
| 269 |
t += 31 + *ip++;
|
| 270 |
}
|
| 271 |
#if defined(COPY_DICT)
|
| 272 |
#if defined(LZO1Z)
|
| 273 |
m_off = 1 + (ip[0] << 6) + (ip[1] >> 2);
|
| 274 |
last_m_off = m_off;
|
| 275 |
#else
|
| 276 |
m_off = 1 + (ip[0] >> 2) + (ip[1] << 6);
|
| 277 |
#endif
|
| 278 |
#else /* !COPY_DICT */
|
| 279 |
#if defined(LZO1Z)
|
| 280 |
{
|
| 281 |
lzo_uint off = 1 + (ip[0] << 6) + (ip[1] >> 2);
|
| 282 |
m_pos = op - off;
|
| 283 |
last_m_off = off;
|
| 284 |
}
|
| 285 |
#elif defined(LZO_UNALIGNED_OK_2) && defined(LZO_ABI_LITTLE_ENDIAN)
|
| 286 |
m_pos = op - 1;
|
| 287 |
m_pos -= (* (const lzo_ushortp) ip) >> 2;
|
| 288 |
#else
|
| 289 |
m_pos = op - 1;
|
| 290 |
m_pos -= (ip[0] >> 2) + (ip[1] << 6);
|
| 291 |
#endif
|
| 292 |
#endif /* COPY_DICT */
|
| 293 |
ip += 2;
|
| 294 |
}
|
| 295 |
else if (t >= 16) /* a M4 match */
|
| 296 |
{
|
| 297 |
#if defined(COPY_DICT)
|
| 298 |
m_off = (t & 8) << 11;
|
| 299 |
#else /* !COPY_DICT */
|
| 300 |
m_pos = op;
|
| 301 |
m_pos -= (t & 8) << 11;
|
| 302 |
#endif /* COPY_DICT */
|
| 303 |
t &= 7;
|
| 304 |
if (t == 0)
|
| 305 |
{
|
| 306 |
NEED_IP(1);
|
| 307 |
while (*ip == 0)
|
| 308 |
{
|
| 309 |
t += 255;
|
| 310 |
ip++;
|
| 311 |
NEED_IP(1);
|
| 312 |
}
|
| 313 |
t += 7 + *ip++;
|
| 314 |
}
|
| 315 |
#if defined(COPY_DICT)
|
| 316 |
#if defined(LZO1Z)
|
| 317 |
m_off += (ip[0] << 6) + (ip[1] >> 2);
|
| 318 |
#else
|
| 319 |
m_off += (ip[0] >> 2) + (ip[1] << 6);
|
| 320 |
#endif
|
| 321 |
ip += 2;
|
| 322 |
if (m_off == 0)
|
| 323 |
goto eof_found;
|
| 324 |
m_off += 0x4000;
|
| 325 |
#if defined(LZO1Z)
|
| 326 |
last_m_off = m_off;
|
| 327 |
#endif
|
| 328 |
#else /* !COPY_DICT */
|
| 329 |
#if defined(LZO1Z)
|
| 330 |
m_pos -= (ip[0] << 6) + (ip[1] >> 2);
|
| 331 |
#elif defined(LZO_UNALIGNED_OK_2) && defined(LZO_ABI_LITTLE_ENDIAN)
|
| 332 |
m_pos -= (* (const lzo_ushortp) ip) >> 2;
|
| 333 |
#else
|
| 334 |
m_pos -= (ip[0] >> 2) + (ip[1] << 6);
|
| 335 |
#endif
|
| 336 |
ip += 2;
|
| 337 |
if (m_pos == op)
|
| 338 |
goto eof_found;
|
| 339 |
m_pos -= 0x4000;
|
| 340 |
#if defined(LZO1Z)
|
| 341 |
last_m_off = pd((const lzo_bytep)op, m_pos);
|
| 342 |
#endif
|
| 343 |
#endif /* COPY_DICT */
|
| 344 |
}
|
| 345 |
else /* a M1 match */
|
| 346 |
{
|
| 347 |
#if defined(COPY_DICT)
|
| 348 |
#if defined(LZO1Z)
|
| 349 |
m_off = 1 + (t << 6) + (*ip++ >> 2);
|
| 350 |
last_m_off = m_off;
|
| 351 |
#else
|
| 352 |
m_off = 1 + (t >> 2) + (*ip++ << 2);
|
| 353 |
#endif
|
| 354 |
NEED_OP(2);
|
| 355 |
t = 2; COPY_DICT(t,m_off)
|
| 356 |
#else /* !COPY_DICT */
|
| 357 |
#if defined(LZO1Z)
|
| 358 |
t = 1 + (t << 6) + (*ip++ >> 2);
|
| 359 |
m_pos = op - t;
|
| 360 |
last_m_off = t;
|
| 361 |
#else
|
| 362 |
m_pos = op - 1;
|
| 363 |
m_pos -= t >> 2;
|
| 364 |
m_pos -= *ip++ << 2;
|
| 365 |
#endif
|
| 366 |
TEST_LB(m_pos); NEED_OP(2);
|
| 367 |
*op++ = *m_pos++; *op++ = *m_pos;
|
| 368 |
#endif /* COPY_DICT */
|
| 369 |
goto match_done;
|
| 370 |
}
|
| 371 |
|
| 372 |
/* copy match */
|
| 373 |
#if defined(COPY_DICT)
|
| 374 |
|
| 375 |
NEED_OP(t+3-1);
|
| 376 |
t += 3-1; COPY_DICT(t,m_off)
|
| 377 |
|
| 378 |
#else /* !COPY_DICT */
|
| 379 |
|
| 380 |
TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1);
|
| 381 |
#if defined(LZO_UNALIGNED_OK_4) || defined(LZO_ALIGNED_OK_4)
|
| 382 |
#if !defined(LZO_UNALIGNED_OK_4)
|
| 383 |
if (t >= 2 * 4 - (3 - 1) && PTR_ALIGNED2_4(op,m_pos))
|
| 384 |
{
|
| 385 |
assert((op - m_pos) >= 4); /* both pointers are aligned */
|
| 386 |
#else
|
| 387 |
if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4)
|
| 388 |
{
|
| 389 |
#endif
|
| 390 |
COPY4(op,m_pos);
|
| 391 |
op += 4; m_pos += 4; t -= 4 - (3 - 1);
|
| 392 |
do {
|
| 393 |
COPY4(op,m_pos);
|
| 394 |
op += 4; m_pos += 4; t -= 4;
|
| 395 |
} while (t >= 4);
|
| 396 |
if (t > 0) do *op++ = *m_pos++; while (--t > 0);
|
| 397 |
}
|
| 398 |
else
|
| 399 |
#endif
|
| 400 |
{
|
| 401 |
copy_match:
|
| 402 |
*op++ = *m_pos++; *op++ = *m_pos++;
|
| 403 |
do *op++ = *m_pos++; while (--t > 0);
|
| 404 |
}
|
| 405 |
|
| 406 |
#endif /* COPY_DICT */
|
| 407 |
|
| 408 |
match_done:
|
| 409 |
#if defined(LZO1Z)
|
| 410 |
t = ip[-1] & 3;
|
| 411 |
#else
|
| 412 |
t = ip[-2] & 3;
|
| 413 |
#endif
|
| 414 |
if (t == 0)
|
| 415 |
break;
|
| 416 |
|
| 417 |
/* copy literals */
|
| 418 |
match_next:
|
| 419 |
assert(t > 0); assert(t < 4); NEED_OP(t); NEED_IP(t+1);
|
| 420 |
#if 0
|
| 421 |
do *op++ = *ip++; while (--t > 0);
|
| 422 |
#else
|
| 423 |
*op++ = *ip++;
|
| 424 |
if (t > 1) { *op++ = *ip++; if (t > 2) { *op++ = *ip++; } }
|
| 425 |
#endif
|
| 426 |
t = *ip++;
|
| 427 |
} while (TEST_IP && TEST_OP);
|
| 428 |
}
|
| 429 |
|
| 430 |
#if defined(HAVE_TEST_IP) || defined(HAVE_TEST_OP)
|
| 431 |
/* no EOF code was found */
|
| 432 |
*out_len = pd(op, out);
|
| 433 |
return LZO_E_EOF_NOT_FOUND;
|
| 434 |
#endif
|
| 435 |
|
| 436 |
eof_found:
|
| 437 |
assert(t == 1);
|
| 438 |
*out_len = pd(op, out);
|
| 439 |
return (ip == ip_end ? LZO_E_OK :
|
| 440 |
(ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
|
| 441 |
|
| 442 |
|
| 443 |
#if defined(HAVE_NEED_IP)
|
| 444 |
input_overrun:
|
| 445 |
*out_len = pd(op, out);
|
| 446 |
return LZO_E_INPUT_OVERRUN;
|
| 447 |
#endif
|
| 448 |
|
| 449 |
#if defined(HAVE_NEED_OP)
|
| 450 |
output_overrun:
|
| 451 |
*out_len = pd(op, out);
|
| 452 |
return LZO_E_OUTPUT_OVERRUN;
|
| 453 |
#endif
|
| 454 |
|
| 455 |
#if defined(LZO_TEST_OVERRUN_LOOKBEHIND)
|
| 456 |
lookbehind_overrun:
|
| 457 |
*out_len = pd(op, out);
|
| 458 |
return LZO_E_LOOKBEHIND_OVERRUN;
|
| 459 |
#endif
|
| 460 |
}
|
| 461 |
|
| 462 |
|
| 463 |
/*
|
| 464 |
vi:ts=4:et
|
| 465 |
*/
|
| 466 |
|
