source: MondoRescue/branches/3.3/mindi-busybox/archival/libarchive/decompress_unlzma.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: 11.9 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Small lzma deflate implementation.
4 * Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
5 *
6 * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
7 * Copyright (C) 1999-2005 Igor Pavlov
8 *
9 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 */
11#include "libbb.h"
12#include "bb_archive.h"
13
14#if ENABLE_FEATURE_LZMA_FAST
15# define speed_inline ALWAYS_INLINE
16# define size_inline
17#else
18# define speed_inline
19# define size_inline ALWAYS_INLINE
20#endif
21
22
23typedef struct {
24 int fd;
25 uint8_t *ptr;
26
27/* Was keeping rc on stack in unlzma and separately allocating buffer,
28 * but with "buffer 'attached to' allocated rc" code is smaller: */
29 /* uint8_t *buffer; */
30#define RC_BUFFER ((uint8_t*)(rc+1))
31
32 uint8_t *buffer_end;
33
34/* Had provisions for variable buffer, but we don't need it here */
35 /* int buffer_size; */
36#define RC_BUFFER_SIZE 0x10000
37
38 uint32_t code;
39 uint32_t range;
40 uint32_t bound;
41} rc_t;
42
43#define RC_TOP_BITS 24
44#define RC_MOVE_BITS 5
45#define RC_MODEL_TOTAL_BITS 11
46
47
48/* Called once in rc_do_normalize() */
49static void rc_read(rc_t *rc)
50{
51 int buffer_size = safe_read(rc->fd, RC_BUFFER, RC_BUFFER_SIZE);
52//TODO: return -1 instead
53//This will make unlzma delete broken unpacked file on unpack errors
54 if (buffer_size <= 0)
55 bb_error_msg_and_die("unexpected EOF");
56 rc->buffer_end = RC_BUFFER + buffer_size;
57 rc->ptr = RC_BUFFER;
58}
59
60/* Called twice, but one callsite is in speed_inline'd rc_is_bit_1() */
61static void rc_do_normalize(rc_t *rc)
62{
63 if (rc->ptr >= rc->buffer_end)
64 rc_read(rc);
65 rc->range <<= 8;
66 rc->code = (rc->code << 8) | *rc->ptr++;
67}
68static ALWAYS_INLINE void rc_normalize(rc_t *rc)
69{
70 if (rc->range < (1 << RC_TOP_BITS)) {
71 rc_do_normalize(rc);
72 }
73}
74
75/* Called once */
76static ALWAYS_INLINE rc_t* rc_init(int fd) /*, int buffer_size) */
77{
78 int i;
79 rc_t *rc;
80
81 rc = xzalloc(sizeof(*rc) + RC_BUFFER_SIZE);
82
83 rc->fd = fd;
84 /* rc->ptr = rc->buffer_end; */
85
86 for (i = 0; i < 5; i++) {
87 rc_do_normalize(rc);
88 }
89 rc->range = 0xffffffff;
90 return rc;
91}
92
93/* Called once */
94static ALWAYS_INLINE void rc_free(rc_t *rc)
95{
96 free(rc);
97}
98
99/* rc_is_bit_1 is called 9 times */
100static speed_inline int rc_is_bit_1(rc_t *rc, uint16_t *p)
101{
102 rc_normalize(rc);
103 rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
104 if (rc->code < rc->bound) {
105 rc->range = rc->bound;
106 *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
107 return 0;
108 }
109 rc->range -= rc->bound;
110 rc->code -= rc->bound;
111 *p -= *p >> RC_MOVE_BITS;
112 return 1;
113}
114
115/* Called 4 times in unlzma loop */
116static ALWAYS_INLINE int rc_get_bit(rc_t *rc, uint16_t *p, int *symbol)
117{
118 int ret = rc_is_bit_1(rc, p);
119 *symbol = *symbol * 2 + ret;
120 return ret;
121}
122
123/* Called once */
124static ALWAYS_INLINE int rc_direct_bit(rc_t *rc)
125{
126 rc_normalize(rc);
127 rc->range >>= 1;
128 if (rc->code >= rc->range) {
129 rc->code -= rc->range;
130 return 1;
131 }
132 return 0;
133}
134
135/* Called twice */
136static speed_inline void
137rc_bit_tree_decode(rc_t *rc, uint16_t *p, int num_levels, int *symbol)
138{
139 int i = num_levels;
140
141 *symbol = 1;
142 while (i--)
143 rc_get_bit(rc, p + *symbol, symbol);
144 *symbol -= 1 << num_levels;
145}
146
147
148typedef struct {
149 uint8_t pos;
150 uint32_t dict_size;
151 uint64_t dst_size;
152} PACKED lzma_header_t;
153
154
155/* #defines will force compiler to compute/optimize each one with each usage.
156 * Have heart and use enum instead. */
157enum {
158 LZMA_BASE_SIZE = 1846,
159 LZMA_LIT_SIZE = 768,
160
161 LZMA_NUM_POS_BITS_MAX = 4,
162
163 LZMA_LEN_NUM_LOW_BITS = 3,
164 LZMA_LEN_NUM_MID_BITS = 3,
165 LZMA_LEN_NUM_HIGH_BITS = 8,
166
167 LZMA_LEN_CHOICE = 0,
168 LZMA_LEN_CHOICE_2 = (LZMA_LEN_CHOICE + 1),
169 LZMA_LEN_LOW = (LZMA_LEN_CHOICE_2 + 1),
170 LZMA_LEN_MID = (LZMA_LEN_LOW \
171 + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS))),
172 LZMA_LEN_HIGH = (LZMA_LEN_MID \
173 + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS))),
174 LZMA_NUM_LEN_PROBS = (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS)),
175
176 LZMA_NUM_STATES = 12,
177 LZMA_NUM_LIT_STATES = 7,
178
179 LZMA_START_POS_MODEL_INDEX = 4,
180 LZMA_END_POS_MODEL_INDEX = 14,
181 LZMA_NUM_FULL_DISTANCES = (1 << (LZMA_END_POS_MODEL_INDEX >> 1)),
182
183 LZMA_NUM_POS_SLOT_BITS = 6,
184 LZMA_NUM_LEN_TO_POS_STATES = 4,
185
186 LZMA_NUM_ALIGN_BITS = 4,
187
188 LZMA_MATCH_MIN_LEN = 2,
189
190 LZMA_IS_MATCH = 0,
191 LZMA_IS_REP = (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
192 LZMA_IS_REP_G0 = (LZMA_IS_REP + LZMA_NUM_STATES),
193 LZMA_IS_REP_G1 = (LZMA_IS_REP_G0 + LZMA_NUM_STATES),
194 LZMA_IS_REP_G2 = (LZMA_IS_REP_G1 + LZMA_NUM_STATES),
195 LZMA_IS_REP_0_LONG = (LZMA_IS_REP_G2 + LZMA_NUM_STATES),
196 LZMA_POS_SLOT = (LZMA_IS_REP_0_LONG \
197 + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
198 LZMA_SPEC_POS = (LZMA_POS_SLOT \
199 + (LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS)),
200 LZMA_ALIGN = (LZMA_SPEC_POS \
201 + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX),
202 LZMA_LEN_CODER = (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS)),
203 LZMA_REP_LEN_CODER = (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS),
204 LZMA_LITERAL = (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS),
205};
206
207
208IF_DESKTOP(long long) int FAST_FUNC
209unpack_lzma_stream(transformer_state_t *xstate)
210{
211 IF_DESKTOP(long long total_written = 0;)
212 lzma_header_t header;
213 int lc, pb, lp;
214 uint32_t pos_state_mask;
215 uint32_t literal_pos_mask;
216 uint16_t *p;
217 rc_t *rc;
218 int i;
219 uint8_t *buffer;
220 uint8_t previous_byte = 0;
221 size_t buffer_pos = 0, global_pos = 0;
222 int len = 0;
223 int state = 0;
224 uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
225
226 if (full_read(xstate->src_fd, &header, sizeof(header)) != sizeof(header)
227 || header.pos >= (9 * 5 * 5)
228 ) {
229 bb_error_msg("bad lzma header");
230 return -1;
231 }
232
233 i = header.pos / 9;
234 lc = header.pos % 9;
235 pb = i / 5;
236 lp = i % 5;
237 pos_state_mask = (1 << pb) - 1;
238 literal_pos_mask = (1 << lp) - 1;
239
240 /* Example values from linux-3.3.4.tar.lzma:
241 * dict_size: 64M, dst_size: 2^64-1
242 */
243 header.dict_size = SWAP_LE32(header.dict_size);
244 header.dst_size = SWAP_LE64(header.dst_size);
245
246 if (header.dict_size == 0)
247 header.dict_size++;
248
249 buffer = xmalloc(MIN(header.dst_size, header.dict_size));
250
251 {
252 int num_probs;
253
254 num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
255 p = xmalloc(num_probs * sizeof(*p));
256 num_probs += LZMA_LITERAL - LZMA_BASE_SIZE;
257 for (i = 0; i < num_probs; i++)
258 p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
259 }
260
261 rc = rc_init(xstate->src_fd); /*, RC_BUFFER_SIZE); */
262
263 while (global_pos + buffer_pos < header.dst_size) {
264 int pos_state = (buffer_pos + global_pos) & pos_state_mask;
265 uint16_t *prob = p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
266
267 if (!rc_is_bit_1(rc, prob)) {
268 static const char next_state[LZMA_NUM_STATES] =
269 { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 };
270 int mi = 1;
271
272 prob = (p + LZMA_LITERAL
273 + (LZMA_LIT_SIZE * ((((buffer_pos + global_pos) & literal_pos_mask) << lc)
274 + (previous_byte >> (8 - lc))
275 )
276 )
277 );
278
279 if (state >= LZMA_NUM_LIT_STATES) {
280 int match_byte;
281 uint32_t pos = buffer_pos - rep0;
282
283 while (pos >= header.dict_size)
284 pos += header.dict_size;
285 match_byte = buffer[pos];
286 do {
287 int bit;
288
289 match_byte <<= 1;
290 bit = match_byte & 0x100;
291 bit ^= (rc_get_bit(rc, prob + 0x100 + bit + mi, &mi) << 8); /* 0x100 or 0 */
292 if (bit)
293 break;
294 } while (mi < 0x100);
295 }
296 while (mi < 0x100) {
297 rc_get_bit(rc, prob + mi, &mi);
298 }
299
300 state = next_state[state];
301
302 previous_byte = (uint8_t) mi;
303#if ENABLE_FEATURE_LZMA_FAST
304 one_byte1:
305 buffer[buffer_pos++] = previous_byte;
306 if (buffer_pos == header.dict_size) {
307 buffer_pos = 0;
308 global_pos += header.dict_size;
309 if (transformer_write(xstate, buffer, header.dict_size) != (ssize_t)header.dict_size)
310 goto bad;
311 IF_DESKTOP(total_written += header.dict_size;)
312 }
313#else
314 len = 1;
315 goto one_byte2;
316#endif
317 } else {
318 int num_bits;
319 int offset;
320 uint16_t *prob2;
321#define prob_len prob2
322
323 prob2 = p + LZMA_IS_REP + state;
324 if (!rc_is_bit_1(rc, prob2)) {
325 rep3 = rep2;
326 rep2 = rep1;
327 rep1 = rep0;
328 state = state < LZMA_NUM_LIT_STATES ? 0 : 3;
329 prob2 = p + LZMA_LEN_CODER;
330 } else {
331 prob2 += LZMA_IS_REP_G0 - LZMA_IS_REP;
332 if (!rc_is_bit_1(rc, prob2)) {
333 prob2 = (p + LZMA_IS_REP_0_LONG
334 + (state << LZMA_NUM_POS_BITS_MAX)
335 + pos_state
336 );
337 if (!rc_is_bit_1(rc, prob2)) {
338#if ENABLE_FEATURE_LZMA_FAST
339 uint32_t pos = buffer_pos - rep0;
340 state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
341 while (pos >= header.dict_size)
342 pos += header.dict_size;
343 previous_byte = buffer[pos];
344 goto one_byte1;
345#else
346 state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
347 len = 1;
348 goto string;
349#endif
350 }
351 } else {
352 uint32_t distance;
353
354 prob2 += LZMA_IS_REP_G1 - LZMA_IS_REP_G0;
355 distance = rep1;
356 if (rc_is_bit_1(rc, prob2)) {
357 prob2 += LZMA_IS_REP_G2 - LZMA_IS_REP_G1;
358 distance = rep2;
359 if (rc_is_bit_1(rc, prob2)) {
360 distance = rep3;
361 rep3 = rep2;
362 }
363 rep2 = rep1;
364 }
365 rep1 = rep0;
366 rep0 = distance;
367 }
368 state = state < LZMA_NUM_LIT_STATES ? 8 : 11;
369 prob2 = p + LZMA_REP_LEN_CODER;
370 }
371
372 prob_len = prob2 + LZMA_LEN_CHOICE;
373 num_bits = LZMA_LEN_NUM_LOW_BITS;
374 if (!rc_is_bit_1(rc, prob_len)) {
375 prob_len += LZMA_LEN_LOW - LZMA_LEN_CHOICE
376 + (pos_state << LZMA_LEN_NUM_LOW_BITS);
377 offset = 0;
378 } else {
379 prob_len += LZMA_LEN_CHOICE_2 - LZMA_LEN_CHOICE;
380 if (!rc_is_bit_1(rc, prob_len)) {
381 prob_len += LZMA_LEN_MID - LZMA_LEN_CHOICE_2
382 + (pos_state << LZMA_LEN_NUM_MID_BITS);
383 offset = 1 << LZMA_LEN_NUM_LOW_BITS;
384 num_bits += LZMA_LEN_NUM_MID_BITS - LZMA_LEN_NUM_LOW_BITS;
385 } else {
386 prob_len += LZMA_LEN_HIGH - LZMA_LEN_CHOICE_2;
387 offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
388 + (1 << LZMA_LEN_NUM_MID_BITS));
389 num_bits += LZMA_LEN_NUM_HIGH_BITS - LZMA_LEN_NUM_LOW_BITS;
390 }
391 }
392 rc_bit_tree_decode(rc, prob_len, num_bits, &len);
393 len += offset;
394
395 if (state < 4) {
396 int pos_slot;
397 uint16_t *prob3;
398
399 state += LZMA_NUM_LIT_STATES;
400 prob3 = p + LZMA_POS_SLOT +
401 ((len < LZMA_NUM_LEN_TO_POS_STATES ? len :
402 LZMA_NUM_LEN_TO_POS_STATES - 1)
403 << LZMA_NUM_POS_SLOT_BITS);
404 rc_bit_tree_decode(rc, prob3,
405 LZMA_NUM_POS_SLOT_BITS, &pos_slot);
406 rep0 = pos_slot;
407 if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
408 int i2, mi2, num_bits2 = (pos_slot >> 1) - 1;
409 rep0 = 2 | (pos_slot & 1);
410 if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
411 rep0 <<= num_bits2;
412 prob3 = p + LZMA_SPEC_POS + rep0 - pos_slot - 1;
413 } else {
414 for (; num_bits2 != LZMA_NUM_ALIGN_BITS; num_bits2--)
415 rep0 = (rep0 << 1) | rc_direct_bit(rc);
416 rep0 <<= LZMA_NUM_ALIGN_BITS;
417 prob3 = p + LZMA_ALIGN;
418 }
419 i2 = 1;
420 mi2 = 1;
421 while (num_bits2--) {
422 if (rc_get_bit(rc, prob3 + mi2, &mi2))
423 rep0 |= i2;
424 i2 <<= 1;
425 }
426 }
427 if (++rep0 == 0)
428 break;
429 }
430
431 len += LZMA_MATCH_MIN_LEN;
432 IF_NOT_FEATURE_LZMA_FAST(string:)
433 do {
434 uint32_t pos = buffer_pos - rep0;
435 while (pos >= header.dict_size)
436 pos += header.dict_size;
437 previous_byte = buffer[pos];
438 IF_NOT_FEATURE_LZMA_FAST(one_byte2:)
439 buffer[buffer_pos++] = previous_byte;
440 if (buffer_pos == header.dict_size) {
441 buffer_pos = 0;
442 global_pos += header.dict_size;
443 if (transformer_write(xstate, buffer, header.dict_size) != (ssize_t)header.dict_size)
444 goto bad;
445 IF_DESKTOP(total_written += header.dict_size;)
446 }
447 len--;
448 } while (len != 0 && buffer_pos < header.dst_size);
449 /* FIXME: ...........^^^^^
450 * shouldn't it be "global_pos + buffer_pos < header.dst_size"?
451 */
452 }
453 }
454
455 {
456 IF_NOT_DESKTOP(int total_written = 0; /* success */)
457 IF_DESKTOP(total_written += buffer_pos;)
458 if (transformer_write(xstate, buffer, buffer_pos) != (ssize_t)buffer_pos) {
459 bad:
460 total_written = -1; /* failure */
461 }
462 rc_free(rc);
463 free(p);
464 free(buffer);
465 return total_written;
466 }
467}
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