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[u-tools.git] / u-tools / apps / busybox / archival / libunarchive / decompress_unlzma.c
blob2cfcd9b7d3d9f1980602c23c606c3776bda4bab1
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 tarball for details.
10 */
11
12 #include "libbb.h"
13 #include "unarchive.h"
14
15 #if ENABLE_FEATURE_LZMA_FAST
16 # define speed_inline ALWAYS_INLINE
17 #else
18 # define speed_inline
19 #endif
20
21
22 typedef struct {
23 int fd;
24 uint8_t *ptr;
25
26 /* Was keeping rc on stack in unlzma and separately allocating buffer,
27 * but with "buffer 'attached to' allocated rc" code is smaller: */
28 /* uint8_t *buffer; */
29 #define RC_BUFFER ((uint8_t*)(rc+1))
30
31 uint8_t *buffer_end;
32
33 /* Had provisions for variable buffer, but we don't need it here */
34 /* int buffer_size; */
35 #define RC_BUFFER_SIZE 0x10000
36
37 uint32_t code;
38 uint32_t range;
39 uint32_t bound;
40 } rc_t;
41
42 #define RC_TOP_BITS 24
43 #define RC_MOVE_BITS 5
44 #define RC_MODEL_TOTAL_BITS 11
45
46
47 /* Called twice: once at startup and once in rc_normalize() */
48 static void rc_read(rc_t *rc)
49 {
50 int buffer_size = safe_read(rc->fd, RC_BUFFER, RC_BUFFER_SIZE);
51 if (buffer_size <= 0)
52 bb_error_msg_and_die("unexpected EOF");
53 rc->ptr = RC_BUFFER;
54 rc->buffer_end = RC_BUFFER + buffer_size;
55 }
56
57 /* Called once */
58 static rc_t* rc_init(int fd) /*, int buffer_size) */
59 {
60 int i;
61 rc_t *rc;
62
63 rc = xmalloc(sizeof(*rc) + RC_BUFFER_SIZE);
64
65 rc->fd = fd;
66 /* rc->buffer_size = buffer_size; */
67 rc->buffer_end = RC_BUFFER + RC_BUFFER_SIZE;
68 rc->ptr = rc->buffer_end;
69
70 rc->code = 0;
71 rc->range = 0xFFFFFFFF;
72 for (i = 0; i < 5; i++) {
73 if (rc->ptr >= rc->buffer_end)
74 rc_read(rc);
75 rc->code = (rc->code << 8) | *rc->ptr++;
76 }
77 return rc;
78 }
79
80 /* Called once */
81 static ALWAYS_INLINE void rc_free(rc_t *rc)
82 {
83 free(rc);
84 }
85
86 /* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */
87 static void rc_do_normalize(rc_t *rc)
88 {
89 if (rc->ptr >= rc->buffer_end)
90 rc_read(rc);
91 rc->range <<= 8;
92 rc->code = (rc->code << 8) | *rc->ptr++;
93 }
94 static ALWAYS_INLINE void rc_normalize(rc_t *rc)
95 {
96 if (rc->range < (1 << RC_TOP_BITS)) {
97 rc_do_normalize(rc);
98 }
99 }
100
101 /* rc_is_bit_0 is called 9 times */
102 /* Why rc_is_bit_0_helper exists?
103 * Because we want to always expose (rc->code < rc->bound) to optimizer.
104 * Thus rc_is_bit_0 is always inlined, and rc_is_bit_0_helper is inlined
105 * only if we compile for speed.
106 */
107 static speed_inline uint32_t rc_is_bit_0_helper(rc_t *rc, uint16_t *p)
108 {
109 rc_normalize(rc);
110 rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
111 return rc->bound;
112 }
113 static ALWAYS_INLINE int rc_is_bit_0(rc_t *rc, uint16_t *p)
114 {
115 uint32_t t = rc_is_bit_0_helper(rc, p);
116 return rc->code < t;
117 }
118
119 /* Called ~10 times, but very small, thus inlined */
120 static speed_inline void rc_update_bit_0(rc_t *rc, uint16_t *p)
121 {
122 rc->range = rc->bound;
123 *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
124 }
125 static speed_inline void rc_update_bit_1(rc_t *rc, uint16_t *p)
126 {
127 rc->range -= rc->bound;
128 rc->code -= rc->bound;
129 *p -= *p >> RC_MOVE_BITS;
130 }
131
132 /* Called 4 times in unlzma loop */
133 static int rc_get_bit(rc_t *rc, uint16_t *p, int *symbol)
134 {
135 if (rc_is_bit_0(rc, p)) {
136 rc_update_bit_0(rc, p);
137 *symbol *= 2;
138 return 0;
139 } else {
140 rc_update_bit_1(rc, p);
141 *symbol = *symbol * 2 + 1;
142 return 1;
143 }
144 }
145
146 /* Called once */
147 static ALWAYS_INLINE int rc_direct_bit(rc_t *rc)
148 {
149 rc_normalize(rc);
150 rc->range >>= 1;
151 if (rc->code >= rc->range) {
152 rc->code -= rc->range;
153 return 1;
154 }
155 return 0;
156 }
157
158 /* Called twice */
159 static speed_inline void
160 rc_bit_tree_decode(rc_t *rc, uint16_t *p, int num_levels, int *symbol)
161 {
162 int i = num_levels;
163
164 *symbol = 1;
165 while (i--)
166 rc_get_bit(rc, p + *symbol, symbol);
167 *symbol -= 1 << num_levels;
168 }
169
170
171 typedef struct {
172 uint8_t pos;
173 uint32_t dict_size;
174 uint64_t dst_size;
175 } __attribute__ ((packed)) lzma_header_t;
176
177
178 /* #defines will force compiler to compute/optimize each one with each usage.
179 * Have heart and use enum instead. */
180 enum {
181 LZMA_BASE_SIZE = 1846,
182 LZMA_LIT_SIZE = 768,
183
184 LZMA_NUM_POS_BITS_MAX = 4,
185
186 LZMA_LEN_NUM_LOW_BITS = 3,
187 LZMA_LEN_NUM_MID_BITS = 3,
188 LZMA_LEN_NUM_HIGH_BITS = 8,
189
190 LZMA_LEN_CHOICE = 0,
191 LZMA_LEN_CHOICE_2 = (LZMA_LEN_CHOICE + 1),
192 LZMA_LEN_LOW = (LZMA_LEN_CHOICE_2 + 1),
193 LZMA_LEN_MID = (LZMA_LEN_LOW \
194 + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS))),
195 LZMA_LEN_HIGH = (LZMA_LEN_MID \
196 + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS))),
197 LZMA_NUM_LEN_PROBS = (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS)),
198
199 LZMA_NUM_STATES = 12,
200 LZMA_NUM_LIT_STATES = 7,
201
202 LZMA_START_POS_MODEL_INDEX = 4,
203 LZMA_END_POS_MODEL_INDEX = 14,
204 LZMA_NUM_FULL_DISTANCES = (1 << (LZMA_END_POS_MODEL_INDEX >> 1)),
205
206 LZMA_NUM_POS_SLOT_BITS = 6,
207 LZMA_NUM_LEN_TO_POS_STATES = 4,
208
209 LZMA_NUM_ALIGN_BITS = 4,
210
211 LZMA_MATCH_MIN_LEN = 2,
212
213 LZMA_IS_MATCH = 0,
214 LZMA_IS_REP = (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
215 LZMA_IS_REP_G0 = (LZMA_IS_REP + LZMA_NUM_STATES),
216 LZMA_IS_REP_G1 = (LZMA_IS_REP_G0 + LZMA_NUM_STATES),
217 LZMA_IS_REP_G2 = (LZMA_IS_REP_G1 + LZMA_NUM_STATES),
218 LZMA_IS_REP_0_LONG = (LZMA_IS_REP_G2 + LZMA_NUM_STATES),
219 LZMA_POS_SLOT = (LZMA_IS_REP_0_LONG \
220 + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
221 LZMA_SPEC_POS = (LZMA_POS_SLOT \
222 + (LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS)),
223 LZMA_ALIGN = (LZMA_SPEC_POS \
224 + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX),
225 LZMA_LEN_CODER = (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS)),
226 LZMA_REP_LEN_CODER = (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS),
227 LZMA_LITERAL = (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS),
228 };
229
230
231 USE_DESKTOP(long long) int FAST_FUNC
232 unpack_lzma_stream(int src_fd, int dst_fd)
233 {
234 USE_DESKTOP(long long total_written = 0;)
235 lzma_header_t header;
236 int lc, pb, lp;
237 uint32_t pos_state_mask;
238 uint32_t literal_pos_mask;
239 uint32_t pos;
240 uint16_t *p;
241 uint16_t *prob;
242 uint16_t *prob_lit;
243 int num_bits;
244 int num_probs;
245 rc_t *rc;
246 int i, mi;
247 uint8_t *buffer;
248 uint8_t previous_byte = 0;
249 size_t buffer_pos = 0, global_pos = 0;
250 int len = 0;
251 int state = 0;
252 uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
253
254 xread(src_fd, &header, sizeof(header));
255
256 if (header.pos >= (9 * 5 * 5))
257 bb_error_msg_and_die("bad header");
258 mi = header.pos / 9;
259 lc = header.pos % 9;
260 pb = mi / 5;
261 lp = mi % 5;
262 pos_state_mask = (1 << pb) - 1;
263 literal_pos_mask = (1 << lp) - 1;
264
265 header.dict_size = SWAP_LE32(header.dict_size);
266 header.dst_size = SWAP_LE64(header.dst_size);
267
268 if (header.dict_size == 0)
269 header.dict_size = 1;
270
271 buffer = xmalloc(MIN(header.dst_size, header.dict_size));
272
273 num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
274 p = xmalloc(num_probs * sizeof(*p));
275 num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
276 for (i = 0; i < num_probs; i++)
277 p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
278
279 rc = rc_init(src_fd); /*, RC_BUFFER_SIZE); */
280
281 while (global_pos + buffer_pos < header.dst_size) {
282 int pos_state = (buffer_pos + global_pos) & pos_state_mask;
283
284 prob = p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
285 if (rc_is_bit_0(rc, prob)) {
286 mi = 1;
287 rc_update_bit_0(rc, prob);
288 prob = (p + LZMA_LITERAL
289 + (LZMA_LIT_SIZE * ((((buffer_pos + global_pos) & literal_pos_mask) << lc)
290 + (previous_byte >> (8 - lc))
291 )
292 )
293 );
294
295 if (state >= LZMA_NUM_LIT_STATES) {
296 int match_byte;
297
298 pos = buffer_pos - rep0;
299 while (pos >= header.dict_size)
300 pos += header.dict_size;
301 match_byte = buffer[pos];
302 do {
303 int bit;
304
305 match_byte <<= 1;
306 bit = match_byte & 0x100;
307 prob_lit = prob + 0x100 + bit + mi;
308 bit ^= (rc_get_bit(rc, prob_lit, &mi) << 8); /* 0x100 or 0 */
309 if (bit)
310 break;
311 } while (mi < 0x100);
312 }
313 while (mi < 0x100) {
314 prob_lit = prob + mi;
315 rc_get_bit(rc, prob_lit, &mi);
316 }
317
318 state -= 3;
319 if (state < 4-3)
320 state = 0;
321 if (state >= 10-3)
322 state -= 6-3;
323
324 previous_byte = (uint8_t) mi;
325 #if ENABLE_FEATURE_LZMA_FAST
326 one_byte1:
327 buffer[buffer_pos++] = previous_byte;
328 if (buffer_pos == header.dict_size) {
329 buffer_pos = 0;
330 global_pos += header.dict_size;
331 if (full_write(dst_fd, buffer, header.dict_size) != (ssize_t)header.dict_size)
332 goto bad;
333 USE_DESKTOP(total_written += header.dict_size;)
334 }
335 #else
336 len = 1;
337 goto one_byte2;
338 #endif
339 } else {
340 int offset;
341 uint16_t *prob_len;
342
343 rc_update_bit_1(rc, prob);
344 prob = p + LZMA_IS_REP + state;
345 if (rc_is_bit_0(rc, prob)) {
346 rc_update_bit_0(rc, prob);
347 rep3 = rep2;
348 rep2 = rep1;
349 rep1 = rep0;
350 state = state < LZMA_NUM_LIT_STATES ? 0 : 3;
351 prob = p + LZMA_LEN_CODER;
352 } else {
353 rc_update_bit_1(rc, prob);
354 prob = p + LZMA_IS_REP_G0 + state;
355 if (rc_is_bit_0(rc, prob)) {
356 rc_update_bit_0(rc, prob);
357 prob = (p + LZMA_IS_REP_0_LONG
358 + (state << LZMA_NUM_POS_BITS_MAX)
359 + pos_state
360 );
361 if (rc_is_bit_0(rc, prob)) {
362 rc_update_bit_0(rc, prob);
363
364 state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
365 #if ENABLE_FEATURE_LZMA_FAST
366 pos = buffer_pos - rep0;
367 while (pos >= header.dict_size)
368 pos += header.dict_size;
369 previous_byte = buffer[pos];
370 goto one_byte1;
371 #else
372 len = 1;
373 goto string;
374 #endif
375 } else {
376 rc_update_bit_1(rc, prob);
377 }
378 } else {
379 uint32_t distance;
380
381 rc_update_bit_1(rc, prob);
382 prob = p + LZMA_IS_REP_G1 + state;
383 if (rc_is_bit_0(rc, prob)) {
384 rc_update_bit_0(rc, prob);
385 distance = rep1;
386 } else {
387 rc_update_bit_1(rc, prob);
388 prob = p + LZMA_IS_REP_G2 + state;
389 if (rc_is_bit_0(rc, prob)) {
390 rc_update_bit_0(rc, prob);
391 distance = rep2;
392 } else {
393 rc_update_bit_1(rc, prob);
394 distance = rep3;
395 rep3 = rep2;
396 }
397 rep2 = rep1;
398 }
399 rep1 = rep0;
400 rep0 = distance;
401 }
402 state = state < LZMA_NUM_LIT_STATES ? 8 : 11;
403 prob = p + LZMA_REP_LEN_CODER;
404 }
405
406 prob_len = prob + LZMA_LEN_CHOICE;
407 if (rc_is_bit_0(rc, prob_len)) {
408 rc_update_bit_0(rc, prob_len);
409 prob_len = (prob + LZMA_LEN_LOW
410 + (pos_state << LZMA_LEN_NUM_LOW_BITS));
411 offset = 0;
412 num_bits = LZMA_LEN_NUM_LOW_BITS;
413 } else {
414 rc_update_bit_1(rc, prob_len);
415 prob_len = prob + LZMA_LEN_CHOICE_2;
416 if (rc_is_bit_0(rc, prob_len)) {
417 rc_update_bit_0(rc, prob_len);
418 prob_len = (prob + LZMA_LEN_MID
419 + (pos_state << LZMA_LEN_NUM_MID_BITS));
420 offset = 1 << LZMA_LEN_NUM_LOW_BITS;
421 num_bits = LZMA_LEN_NUM_MID_BITS;
422 } else {
423 rc_update_bit_1(rc, prob_len);
424 prob_len = prob + LZMA_LEN_HIGH;
425 offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
426 + (1 << LZMA_LEN_NUM_MID_BITS));
427 num_bits = LZMA_LEN_NUM_HIGH_BITS;
428 }
429 }
430 rc_bit_tree_decode(rc, prob_len, num_bits, &len);
431 len += offset;
432
433 if (state < 4) {
434 int pos_slot;
435
436 state += LZMA_NUM_LIT_STATES;
437 prob = p + LZMA_POS_SLOT +
438 ((len < LZMA_NUM_LEN_TO_POS_STATES ? len :
439 LZMA_NUM_LEN_TO_POS_STATES - 1)
440 << LZMA_NUM_POS_SLOT_BITS);
441 rc_bit_tree_decode(rc, prob, LZMA_NUM_POS_SLOT_BITS,
442 &pos_slot);
443 if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
444 num_bits = (pos_slot >> 1) - 1;
445 rep0 = 2 | (pos_slot & 1);
446 if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
447 rep0 <<= num_bits;
448 prob = p + LZMA_SPEC_POS + rep0 - pos_slot - 1;
449 } else {
450 num_bits -= LZMA_NUM_ALIGN_BITS;
451 while (num_bits--)
452 rep0 = (rep0 << 1) | rc_direct_bit(rc);
453 prob = p + LZMA_ALIGN;
454 rep0 <<= LZMA_NUM_ALIGN_BITS;
455 num_bits = LZMA_NUM_ALIGN_BITS;
456 }
457 i = 1;
458 mi = 1;
459 while (num_bits--) {
460 if (rc_get_bit(rc, prob + mi, &mi))
461 rep0 |= i;
462 i <<= 1;
463 }
464 } else
465 rep0 = pos_slot;
466 if (++rep0 == 0)
467 break;
468 }
469
470 len += LZMA_MATCH_MIN_LEN;
471 SKIP_FEATURE_LZMA_FAST(string:)
472 do {
473 pos = buffer_pos - rep0;
474 while (pos >= header.dict_size)
475 pos += header.dict_size;
476 previous_byte = buffer[pos];
477 SKIP_FEATURE_LZMA_FAST(one_byte2:)
478 buffer[buffer_pos++] = previous_byte;
479 if (buffer_pos == header.dict_size) {
480 buffer_pos = 0;
481 global_pos += header.dict_size;
482 if (full_write(dst_fd, buffer, header.dict_size) != (ssize_t)header.dict_size)
483 goto bad;
484 USE_DESKTOP(total_written += header.dict_size;)
485 }
486 len--;
487 } while (len != 0 && buffer_pos < header.dst_size);
488 }
489 }
490
491 {
492 SKIP_DESKTOP(int total_written = 0; /* success */)
493 USE_DESKTOP(total_written += buffer_pos;)
494 if (full_write(dst_fd, buffer, buffer_pos) != (ssize_t)buffer_pos) {
495 bad:
496 total_written = -1; /* failure */
497 }
498 rc_free(rc);
499 free(p);
500 free(buffer);
501 return total_written;
502 }
503 }
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