source: MondoRescue/branches/3.3/mindi-busybox/archival/libarchive/lzo1x_d.c@ 3621

Last change on this file since 3621 was 3621, checked in by Bruno Cornec, 7 years ago

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.
  • Property svn:eol-style set to native
File size: 9.1 KB
Line 
1/* implementation of the LZO1X decompression algorithm
2
3 This file is part of the LZO real-time data compression library.
4
5 Copyright (C) 1996..2008 Markus Franz Xaver Johannes Oberhumer
6 All Rights Reserved.
7
8 Markus F.X.J. Oberhumer <markus@oberhumer.com>
9 http://www.oberhumer.com/opensource/lzo/
10
11 The LZO library is free software; you can redistribute it and/or
12 modify it under the terms of the GNU General Public License as
13 published by the Free Software Foundation; either version 2 of
14 the License, or (at your option) any later version.
15
16 The LZO library is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with the LZO library; see the file COPYING.
23 If not, write to the Free Software Foundation, Inc.,
24 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
25 */
26#include "libbb.h"
27#include "liblzo.h"
28
29/***********************************************************************
30// decompress a block of data.
31************************************************************************/
32/* safe decompression with overrun testing */
33int lzo1x_decompress_safe(const uint8_t* in, unsigned in_len,
34 uint8_t* out, unsigned* out_len,
35 void* wrkmem UNUSED_PARAM)
36{
37 register uint8_t* op;
38 register const uint8_t* ip;
39 register unsigned t;
40#if defined(COPY_DICT)
41 unsigned m_off;
42 const uint8_t* dict_end;
43#else
44 register const uint8_t* m_pos = NULL; /* possibly not needed */
45#endif
46 const uint8_t* const ip_end = in + in_len;
47#if defined(HAVE_ANY_OP)
48 uint8_t* const op_end = out + *out_len;
49#endif
50#if defined(LZO1Z)
51 unsigned last_m_off = 0;
52#endif
53
54// LZO_UNUSED(wrkmem);
55
56#if defined(COPY_DICT)
57 if (dict) {
58 if (dict_len > M4_MAX_OFFSET) {
59 dict += dict_len - M4_MAX_OFFSET;
60 dict_len = M4_MAX_OFFSET;
61 }
62 dict_end = dict + dict_len;
63 } else {
64 dict_len = 0;
65 dict_end = NULL;
66 }
67#endif /* COPY_DICT */
68
69 *out_len = 0;
70
71 op = out;
72 ip = in;
73
74 if (*ip > 17) {
75 t = *ip++ - 17;
76 if (t < 4)
77 goto match_next;
78 assert(t > 0); NEED_OP(t); NEED_IP(t+1);
79 do *op++ = *ip++; while (--t > 0);
80 goto first_literal_run;
81 }
82
83 while (TEST_IP && TEST_OP) {
84 t = *ip++;
85 if (t >= 16)
86 goto match;
87 /* a literal run */
88 if (t == 0) {
89 NEED_IP(1);
90 while (*ip == 0) {
91 t += 255;
92 ip++;
93 NEED_IP(1);
94 }
95 TEST_IV(t);
96 t += 15 + *ip++;
97 }
98 /* copy literals */
99 assert(t > 0);
100 NEED_OP(t+3);
101 NEED_IP(t+4);
102#if defined(LZO_UNALIGNED_OK_4) || defined(LZO_ALIGNED_OK_4)
103# if !defined(LZO_UNALIGNED_OK_4)
104 if (PTR_ALIGNED2_4(op, ip))
105# endif
106 {
107 COPY4(op, ip);
108 op += 4;
109 ip += 4;
110 if (--t > 0) {
111 if (t >= 4) {
112 do {
113 COPY4(op, ip);
114 op += 4;
115 ip += 4;
116 t -= 4;
117 } while (t >= 4);
118 if (t > 0)
119 do *op++ = *ip++; while (--t > 0);
120 } else {
121 do *op++ = *ip++; while (--t > 0);
122 }
123 }
124 }
125# if !defined(LZO_UNALIGNED_OK_4)
126 else
127# endif
128#endif
129#if !defined(LZO_UNALIGNED_OK_4)
130 {
131 *op++ = *ip++;
132 *op++ = *ip++;
133 *op++ = *ip++;
134 do *op++ = *ip++; while (--t > 0);
135 }
136#endif
137
138 first_literal_run:
139 t = *ip++;
140 if (t >= 16)
141 goto match;
142#if defined(COPY_DICT)
143#if defined(LZO1Z)
144 m_off = (1 + M2_MAX_OFFSET) + (t << 6) + (*ip++ >> 2);
145 last_m_off = m_off;
146#else
147 m_off = (1 + M2_MAX_OFFSET) + (t >> 2) + (*ip++ << 2);
148#endif
149 NEED_OP(3);
150 t = 3; COPY_DICT(t,m_off)
151#else /* !COPY_DICT */
152#if defined(LZO1Z)
153 t = (1 + M2_MAX_OFFSET) + (t << 6) + (*ip++ >> 2);
154 m_pos = op - t;
155 last_m_off = t;
156#else
157 m_pos = op - (1 + M2_MAX_OFFSET);
158 m_pos -= t >> 2;
159 m_pos -= *ip++ << 2;
160#endif
161 TEST_LB(m_pos); NEED_OP(3);
162 *op++ = *m_pos++;
163 *op++ = *m_pos++;
164 *op++ = *m_pos;
165#endif /* COPY_DICT */
166 goto match_done;
167
168 /* handle matches */
169 do {
170 match:
171 if (t >= 64) { /* a M2 match */
172#if defined(COPY_DICT)
173#if defined(LZO1X)
174 m_off = 1 + ((t >> 2) & 7) + (*ip++ << 3);
175 t = (t >> 5) - 1;
176#elif defined(LZO1Y)
177 m_off = 1 + ((t >> 2) & 3) + (*ip++ << 2);
178 t = (t >> 4) - 3;
179#elif defined(LZO1Z)
180 m_off = t & 0x1f;
181 if (m_off >= 0x1c)
182 m_off = last_m_off;
183 else {
184 m_off = 1 + (m_off << 6) + (*ip++ >> 2);
185 last_m_off = m_off;
186 }
187 t = (t >> 5) - 1;
188#endif
189#else /* !COPY_DICT */
190#if defined(LZO1X)
191 m_pos = op - 1;
192 m_pos -= (t >> 2) & 7;
193 m_pos -= *ip++ << 3;
194 t = (t >> 5) - 1;
195#elif defined(LZO1Y)
196 m_pos = op - 1;
197 m_pos -= (t >> 2) & 3;
198 m_pos -= *ip++ << 2;
199 t = (t >> 4) - 3;
200#elif defined(LZO1Z)
201 {
202 unsigned off = t & 0x1f;
203 m_pos = op;
204 if (off >= 0x1c) {
205 assert(last_m_off > 0);
206 m_pos -= last_m_off;
207 } else {
208 off = 1 + (off << 6) + (*ip++ >> 2);
209 m_pos -= off;
210 last_m_off = off;
211 }
212 }
213 t = (t >> 5) - 1;
214#endif
215 TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1);
216 goto copy_match;
217#endif /* COPY_DICT */
218 }
219 else if (t >= 32) { /* a M3 match */
220 t &= 31;
221 if (t == 0) {
222 NEED_IP(1);
223 while (*ip == 0) {
224 t += 255;
225 ip++;
226 NEED_IP(1);
227 }
228 TEST_IV(t);
229 t += 31 + *ip++;
230 }
231#if defined(COPY_DICT)
232#if defined(LZO1Z)
233 m_off = 1 + (ip[0] << 6) + (ip[1] >> 2);
234 last_m_off = m_off;
235#else
236 m_off = 1 + (ip[0] >> 2) + (ip[1] << 6);
237#endif
238#else /* !COPY_DICT */
239#if defined(LZO1Z)
240 {
241 unsigned off = 1 + (ip[0] << 6) + (ip[1] >> 2);
242 m_pos = op - off;
243 last_m_off = off;
244 }
245#elif defined(LZO_UNALIGNED_OK_2) && defined(LZO_ABI_LITTLE_ENDIAN)
246 m_pos = op - 1;
247 m_pos -= (* (const lzo_ushortp) ip) >> 2;
248#else
249 m_pos = op - 1;
250 m_pos -= (ip[0] >> 2) + (ip[1] << 6);
251#endif
252#endif /* COPY_DICT */
253 ip += 2;
254 }
255 else if (t >= 16) { /* a M4 match */
256#if defined(COPY_DICT)
257 m_off = (t & 8) << 11;
258#else /* !COPY_DICT */
259 m_pos = op;
260 m_pos -= (t & 8) << 11;
261#endif /* COPY_DICT */
262 t &= 7;
263 if (t == 0) {
264 NEED_IP(1);
265 while (*ip == 0) {
266 t += 255;
267 ip++;
268 NEED_IP(1);
269 }
270 TEST_IV(t);
271 t += 7 + *ip++;
272 }
273#if defined(COPY_DICT)
274#if defined(LZO1Z)
275 m_off += (ip[0] << 6) + (ip[1] >> 2);
276#else
277 m_off += (ip[0] >> 2) + (ip[1] << 6);
278#endif
279 ip += 2;
280 if (m_off == 0)
281 goto eof_found;
282 m_off += 0x4000;
283#if defined(LZO1Z)
284 last_m_off = m_off;
285#endif
286#else /* !COPY_DICT */
287#if defined(LZO1Z)
288 m_pos -= (ip[0] << 6) + (ip[1] >> 2);
289#elif defined(LZO_UNALIGNED_OK_2) && defined(LZO_ABI_LITTLE_ENDIAN)
290 m_pos -= (* (const lzo_ushortp) ip) >> 2;
291#else
292 m_pos -= (ip[0] >> 2) + (ip[1] << 6);
293#endif
294 ip += 2;
295 if (m_pos == op)
296 goto eof_found;
297 m_pos -= 0x4000;
298#if defined(LZO1Z)
299 last_m_off = pd((const uint8_t*)op, m_pos);
300#endif
301#endif /* COPY_DICT */
302 }
303 else { /* a M1 match */
304#if defined(COPY_DICT)
305#if defined(LZO1Z)
306 m_off = 1 + (t << 6) + (*ip++ >> 2);
307 last_m_off = m_off;
308#else
309 m_off = 1 + (t >> 2) + (*ip++ << 2);
310#endif
311 NEED_OP(2);
312 t = 2; COPY_DICT(t,m_off)
313#else /* !COPY_DICT */
314#if defined(LZO1Z)
315 t = 1 + (t << 6) + (*ip++ >> 2);
316 m_pos = op - t;
317 last_m_off = t;
318#else
319 m_pos = op - 1;
320 m_pos -= t >> 2;
321 m_pos -= *ip++ << 2;
322#endif
323 TEST_LB(m_pos); NEED_OP(2);
324 *op++ = *m_pos++;
325 *op++ = *m_pos;
326#endif /* COPY_DICT */
327 goto match_done;
328 }
329
330 /* copy match */
331#if defined(COPY_DICT)
332
333 NEED_OP(t+3-1);
334 t += 3-1; COPY_DICT(t,m_off)
335
336#else /* !COPY_DICT */
337
338 TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1);
339#if defined(LZO_UNALIGNED_OK_4) || defined(LZO_ALIGNED_OK_4)
340# if !defined(LZO_UNALIGNED_OK_4)
341 if (t >= 2 * 4 - (3 - 1) && PTR_ALIGNED2_4(op,m_pos)) {
342 assert((op - m_pos) >= 4); /* both pointers are aligned */
343# else
344 if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) {
345# endif
346 COPY4(op,m_pos);
347 op += 4; m_pos += 4; t -= 4 - (3 - 1);
348 do {
349 COPY4(op,m_pos);
350 op += 4; m_pos += 4; t -= 4;
351 } while (t >= 4);
352 if (t > 0)
353 do *op++ = *m_pos++; while (--t > 0);
354 }
355 else
356#endif
357 {
358 copy_match:
359 *op++ = *m_pos++; *op++ = *m_pos++;
360 do *op++ = *m_pos++; while (--t > 0);
361 }
362
363#endif /* COPY_DICT */
364
365 match_done:
366#if defined(LZO1Z)
367 t = ip[-1] & 3;
368#else
369 t = ip[-2] & 3;
370#endif
371 if (t == 0)
372 break;
373
374 /* copy literals */
375 match_next:
376 assert(t > 0);
377 assert(t < 4);
378 NEED_OP(t);
379 NEED_IP(t+1);
380#if 0
381 do *op++ = *ip++; while (--t > 0);
382#else
383 *op++ = *ip++;
384 if (t > 1) {
385 *op++ = *ip++;
386 if (t > 2)
387 *op++ = *ip++;
388 }
389#endif
390 t = *ip++;
391 } while (TEST_IP && TEST_OP);
392 }
393
394//#if defined(HAVE_TEST_IP) || defined(HAVE_TEST_OP)
395 /* no EOF code was found */
396 *out_len = pd(op, out);
397 return LZO_E_EOF_NOT_FOUND;
398//#endif
399
400 eof_found:
401 assert(t == 1);
402 *out_len = pd(op, out);
403 return (ip == ip_end ? LZO_E_OK :
404 (ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
405
406//#if defined(HAVE_NEED_IP)
407 input_overrun:
408 *out_len = pd(op, out);
409 return LZO_E_INPUT_OVERRUN;
410//#endif
411
412//#if defined(HAVE_NEED_OP)
413 output_overrun:
414 *out_len = pd(op, out);
415 return LZO_E_OUTPUT_OVERRUN;
416//#endif
417
418//#if defined(LZO_TEST_OVERRUN_LOOKBEHIND)
419 lookbehind_overrun:
420 *out_len = pd(op, out);
421 return LZO_E_LOOKBEHIND_OVERRUN;
422//#endif
423}
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