1/////////////////////////////////////////////////////////////////////////////// 2// 3/// \file lz_encoder.c 4/// \brief LZ in window 5/// 6// Authors: Igor Pavlov 7// Lasse Collin 8// 9// This file has been put into the public domain. 10// You can do whatever you want with this file. 11// 12/////////////////////////////////////////////////////////////////////////////// 13 14#include "lz_encoder.h" 15#include "lz_encoder_hash.h" 16 17// See lz_encoder_hash.h. This is a bit hackish but avoids making 18// endianness a conditional in makefiles. 19#if defined(WORDS_BIGENDIAN) && !defined(HAVE_SMALL) 20# include "lz_encoder_hash_table.h" 21#endif 22 23#include "memcmplen.h" 24 25
| 1/////////////////////////////////////////////////////////////////////////////// 2// 3/// \file lz_encoder.c 4/// \brief LZ in window 5/// 6// Authors: Igor Pavlov 7// Lasse Collin 8// 9// This file has been put into the public domain. 10// You can do whatever you want with this file. 11// 12/////////////////////////////////////////////////////////////////////////////// 13 14#include "lz_encoder.h" 15#include "lz_encoder_hash.h" 16 17// See lz_encoder_hash.h. This is a bit hackish but avoids making 18// endianness a conditional in makefiles. 19#if defined(WORDS_BIGENDIAN) && !defined(HAVE_SMALL) 20# include "lz_encoder_hash_table.h" 21#endif 22 23#include "memcmplen.h" 24 25
|
26struct lzma_coder_s {
| 26typedef struct {
|
27 /// LZ-based encoder e.g. LZMA 28 lzma_lz_encoder lz; 29 30 /// History buffer and match finder 31 lzma_mf mf; 32 33 /// Next coder in the chain 34 lzma_next_coder next;
| 27 /// LZ-based encoder e.g. LZMA 28 lzma_lz_encoder lz; 29 30 /// History buffer and match finder 31 lzma_mf mf; 32 33 /// Next coder in the chain 34 lzma_next_coder next;
|
35};
| 35} lzma_coder;
|
36 37 38/// \brief Moves the data in the input window to free space for new data 39/// 40/// mf->buffer is a sliding input window, which keeps mf->keep_size_before 41/// bytes of input history available all the time. Now and then we need to 42/// "slide" the buffer to make space for the new data to the end of the 43/// buffer. At the same time, data older than keep_size_before is dropped. 44/// 45static void 46move_window(lzma_mf *mf) 47{ 48 // Align the move to a multiple of 16 bytes. Some LZ-based encoders 49 // like LZMA use the lowest bits of mf->read_pos to know the 50 // alignment of the uncompressed data. We also get better speed 51 // for memmove() with aligned buffers. 52 assert(mf->read_pos > mf->keep_size_before); 53 const uint32_t move_offset 54 = (mf->read_pos - mf->keep_size_before) & ~UINT32_C(15); 55 56 assert(mf->write_pos > move_offset); 57 const size_t move_size = mf->write_pos - move_offset; 58 59 assert(move_offset + move_size <= mf->size); 60 61 memmove(mf->buffer, mf->buffer + move_offset, move_size); 62 63 mf->offset += move_offset; 64 mf->read_pos -= move_offset; 65 mf->read_limit -= move_offset; 66 mf->write_pos -= move_offset; 67 68 return; 69} 70 71 72/// \brief Tries to fill the input window (mf->buffer) 73/// 74/// If we are the last encoder in the chain, our input data is in in[]. 75/// Otherwise we call the next filter in the chain to process in[] and 76/// write its output to mf->buffer. 77/// 78/// This function must not be called once it has returned LZMA_STREAM_END. 79/// 80static lzma_ret 81fill_window(lzma_coder *coder, const lzma_allocator *allocator, 82 const uint8_t *in, size_t *in_pos, size_t in_size, 83 lzma_action action) 84{ 85 assert(coder->mf.read_pos <= coder->mf.write_pos); 86 87 // Move the sliding window if needed. 88 if (coder->mf.read_pos >= coder->mf.size - coder->mf.keep_size_after) 89 move_window(&coder->mf); 90 91 // Maybe this is ugly, but lzma_mf uses uint32_t for most things 92 // (which I find cleanest), but we need size_t here when filling 93 // the history window. 94 size_t write_pos = coder->mf.write_pos; 95 lzma_ret ret; 96 if (coder->next.code == NULL) { 97 // Not using a filter, simply memcpy() as much as possible. 98 lzma_bufcpy(in, in_pos, in_size, coder->mf.buffer, 99 &write_pos, coder->mf.size); 100 101 ret = action != LZMA_RUN && *in_pos == in_size 102 ? LZMA_STREAM_END : LZMA_OK; 103 104 } else { 105 ret = coder->next.code(coder->next.coder, allocator, 106 in, in_pos, in_size, 107 coder->mf.buffer, &write_pos, 108 coder->mf.size, action); 109 } 110 111 coder->mf.write_pos = write_pos; 112 113 // Silence Valgrind. lzma_memcmplen() can read extra bytes 114 // and Valgrind will give warnings if those bytes are uninitialized 115 // because Valgrind cannot see that the values of the uninitialized 116 // bytes are eventually ignored. 117 memzero(coder->mf.buffer + write_pos, LZMA_MEMCMPLEN_EXTRA); 118 119 // If end of stream has been reached or flushing completed, we allow 120 // the encoder to process all the input (that is, read_pos is allowed 121 // to reach write_pos). Otherwise we keep keep_size_after bytes 122 // available as prebuffer. 123 if (ret == LZMA_STREAM_END) { 124 assert(*in_pos == in_size); 125 ret = LZMA_OK; 126 coder->mf.action = action; 127 coder->mf.read_limit = coder->mf.write_pos; 128 129 } else if (coder->mf.write_pos > coder->mf.keep_size_after) { 130 // This needs to be done conditionally, because if we got 131 // only little new input, there may be too little input 132 // to do any encoding yet. 133 coder->mf.read_limit = coder->mf.write_pos 134 - coder->mf.keep_size_after; 135 } 136 137 // Restart the match finder after finished LZMA_SYNC_FLUSH. 138 if (coder->mf.pending > 0 139 && coder->mf.read_pos < coder->mf.read_limit) { 140 // Match finder may update coder->pending and expects it to 141 // start from zero, so use a temporary variable. 142 const uint32_t pending = coder->mf.pending; 143 coder->mf.pending = 0; 144 145 // Rewind read_pos so that the match finder can hash 146 // the pending bytes. 147 assert(coder->mf.read_pos >= pending); 148 coder->mf.read_pos -= pending; 149 150 // Call the skip function directly instead of using 151 // mf_skip(), since we don't want to touch mf->read_ahead. 152 coder->mf.skip(&coder->mf, pending); 153 } 154 155 return ret; 156} 157 158 159static lzma_ret
| 36 37 38/// \brief Moves the data in the input window to free space for new data 39/// 40/// mf->buffer is a sliding input window, which keeps mf->keep_size_before 41/// bytes of input history available all the time. Now and then we need to 42/// "slide" the buffer to make space for the new data to the end of the 43/// buffer. At the same time, data older than keep_size_before is dropped. 44/// 45static void 46move_window(lzma_mf *mf) 47{ 48 // Align the move to a multiple of 16 bytes. Some LZ-based encoders 49 // like LZMA use the lowest bits of mf->read_pos to know the 50 // alignment of the uncompressed data. We also get better speed 51 // for memmove() with aligned buffers. 52 assert(mf->read_pos > mf->keep_size_before); 53 const uint32_t move_offset 54 = (mf->read_pos - mf->keep_size_before) & ~UINT32_C(15); 55 56 assert(mf->write_pos > move_offset); 57 const size_t move_size = mf->write_pos - move_offset; 58 59 assert(move_offset + move_size <= mf->size); 60 61 memmove(mf->buffer, mf->buffer + move_offset, move_size); 62 63 mf->offset += move_offset; 64 mf->read_pos -= move_offset; 65 mf->read_limit -= move_offset; 66 mf->write_pos -= move_offset; 67 68 return; 69} 70 71 72/// \brief Tries to fill the input window (mf->buffer) 73/// 74/// If we are the last encoder in the chain, our input data is in in[]. 75/// Otherwise we call the next filter in the chain to process in[] and 76/// write its output to mf->buffer. 77/// 78/// This function must not be called once it has returned LZMA_STREAM_END. 79/// 80static lzma_ret 81fill_window(lzma_coder *coder, const lzma_allocator *allocator, 82 const uint8_t *in, size_t *in_pos, size_t in_size, 83 lzma_action action) 84{ 85 assert(coder->mf.read_pos <= coder->mf.write_pos); 86 87 // Move the sliding window if needed. 88 if (coder->mf.read_pos >= coder->mf.size - coder->mf.keep_size_after) 89 move_window(&coder->mf); 90 91 // Maybe this is ugly, but lzma_mf uses uint32_t for most things 92 // (which I find cleanest), but we need size_t here when filling 93 // the history window. 94 size_t write_pos = coder->mf.write_pos; 95 lzma_ret ret; 96 if (coder->next.code == NULL) { 97 // Not using a filter, simply memcpy() as much as possible. 98 lzma_bufcpy(in, in_pos, in_size, coder->mf.buffer, 99 &write_pos, coder->mf.size); 100 101 ret = action != LZMA_RUN && *in_pos == in_size 102 ? LZMA_STREAM_END : LZMA_OK; 103 104 } else { 105 ret = coder->next.code(coder->next.coder, allocator, 106 in, in_pos, in_size, 107 coder->mf.buffer, &write_pos, 108 coder->mf.size, action); 109 } 110 111 coder->mf.write_pos = write_pos; 112 113 // Silence Valgrind. lzma_memcmplen() can read extra bytes 114 // and Valgrind will give warnings if those bytes are uninitialized 115 // because Valgrind cannot see that the values of the uninitialized 116 // bytes are eventually ignored. 117 memzero(coder->mf.buffer + write_pos, LZMA_MEMCMPLEN_EXTRA); 118 119 // If end of stream has been reached or flushing completed, we allow 120 // the encoder to process all the input (that is, read_pos is allowed 121 // to reach write_pos). Otherwise we keep keep_size_after bytes 122 // available as prebuffer. 123 if (ret == LZMA_STREAM_END) { 124 assert(*in_pos == in_size); 125 ret = LZMA_OK; 126 coder->mf.action = action; 127 coder->mf.read_limit = coder->mf.write_pos; 128 129 } else if (coder->mf.write_pos > coder->mf.keep_size_after) { 130 // This needs to be done conditionally, because if we got 131 // only little new input, there may be too little input 132 // to do any encoding yet. 133 coder->mf.read_limit = coder->mf.write_pos 134 - coder->mf.keep_size_after; 135 } 136 137 // Restart the match finder after finished LZMA_SYNC_FLUSH. 138 if (coder->mf.pending > 0 139 && coder->mf.read_pos < coder->mf.read_limit) { 140 // Match finder may update coder->pending and expects it to 141 // start from zero, so use a temporary variable. 142 const uint32_t pending = coder->mf.pending; 143 coder->mf.pending = 0; 144 145 // Rewind read_pos so that the match finder can hash 146 // the pending bytes. 147 assert(coder->mf.read_pos >= pending); 148 coder->mf.read_pos -= pending; 149 150 // Call the skip function directly instead of using 151 // mf_skip(), since we don't want to touch mf->read_ahead. 152 coder->mf.skip(&coder->mf, pending); 153 } 154 155 return ret; 156} 157 158 159static lzma_ret
|
160lz_encode(lzma_coder *coder, const lzma_allocator *allocator,
| 160lz_encode(void *coder_ptr, const lzma_allocator *allocator,
|
161 const uint8_t *restrict in, size_t *restrict in_pos, 162 size_t in_size, 163 uint8_t *restrict out, size_t *restrict out_pos, 164 size_t out_size, lzma_action action) 165{
| 161 const uint8_t *restrict in, size_t *restrict in_pos, 162 size_t in_size, 163 uint8_t *restrict out, size_t *restrict out_pos, 164 size_t out_size, lzma_action action) 165{
|
| 166 lzma_coder *coder = coder_ptr; 167
|
166 while (*out_pos < out_size 167 && (*in_pos < in_size || action != LZMA_RUN)) { 168 // Read more data to coder->mf.buffer if needed. 169 if (coder->mf.action == LZMA_RUN && coder->mf.read_pos 170 >= coder->mf.read_limit) 171 return_if_error(fill_window(coder, allocator, 172 in, in_pos, in_size, action)); 173 174 // Encode 175 const lzma_ret ret = coder->lz.code(coder->lz.coder, 176 &coder->mf, out, out_pos, out_size); 177 if (ret != LZMA_OK) { 178 // Setting this to LZMA_RUN for cases when we are 179 // flushing. It doesn't matter when finishing or if 180 // an error occurred. 181 coder->mf.action = LZMA_RUN; 182 return ret; 183 } 184 } 185 186 return LZMA_OK; 187} 188 189 190static bool 191lz_encoder_prepare(lzma_mf *mf, const lzma_allocator *allocator, 192 const lzma_lz_options *lz_options) 193{ 194 // For now, the dictionary size is limited to 1.5 GiB. This may grow 195 // in the future if needed, but it needs a little more work than just 196 // changing this check. 197 if (lz_options->dict_size < LZMA_DICT_SIZE_MIN 198 || lz_options->dict_size 199 > (UINT32_C(1) << 30) + (UINT32_C(1) << 29) 200 || lz_options->nice_len > lz_options->match_len_max) 201 return true; 202 203 mf->keep_size_before = lz_options->before_size + lz_options->dict_size; 204 205 mf->keep_size_after = lz_options->after_size 206 + lz_options->match_len_max; 207 208 // To avoid constant memmove()s, allocate some extra space. Since 209 // memmove()s become more expensive when the size of the buffer 210 // increases, we reserve more space when a large dictionary is 211 // used to make the memmove() calls rarer. 212 // 213 // This works with dictionaries up to about 3 GiB. If bigger 214 // dictionary is wanted, some extra work is needed: 215 // - Several variables in lzma_mf have to be changed from uint32_t 216 // to size_t. 217 // - Memory usage calculation needs something too, e.g. use uint64_t 218 // for mf->size. 219 uint32_t reserve = lz_options->dict_size / 2; 220 if (reserve > (UINT32_C(1) << 30)) 221 reserve /= 2; 222 223 reserve += (lz_options->before_size + lz_options->match_len_max 224 + lz_options->after_size) / 2 + (UINT32_C(1) << 19); 225 226 const uint32_t old_size = mf->size; 227 mf->size = mf->keep_size_before + reserve + mf->keep_size_after; 228 229 // Deallocate the old history buffer if it exists but has different 230 // size than what is needed now. 231 if (mf->buffer != NULL && old_size != mf->size) { 232 lzma_free(mf->buffer, allocator); 233 mf->buffer = NULL; 234 } 235 236 // Match finder options 237 mf->match_len_max = lz_options->match_len_max; 238 mf->nice_len = lz_options->nice_len; 239 240 // cyclic_size has to stay smaller than 2 Gi. Note that this doesn't 241 // mean limiting dictionary size to less than 2 GiB. With a match 242 // finder that uses multibyte resolution (hashes start at e.g. every 243 // fourth byte), cyclic_size would stay below 2 Gi even when 244 // dictionary size is greater than 2 GiB. 245 // 246 // It would be possible to allow cyclic_size >= 2 Gi, but then we 247 // would need to be careful to use 64-bit types in various places 248 // (size_t could do since we would need bigger than 32-bit address 249 // space anyway). It would also require either zeroing a multigigabyte 250 // buffer at initialization (waste of time and RAM) or allow 251 // normalization in lz_encoder_mf.c to access uninitialized 252 // memory to keep the code simpler. The current way is simple and 253 // still allows pretty big dictionaries, so I don't expect these 254 // limits to change. 255 mf->cyclic_size = lz_options->dict_size + 1; 256 257 // Validate the match finder ID and setup the function pointers. 258 switch (lz_options->match_finder) { 259#ifdef HAVE_MF_HC3 260 case LZMA_MF_HC3: 261 mf->find = &lzma_mf_hc3_find; 262 mf->skip = &lzma_mf_hc3_skip; 263 break; 264#endif 265#ifdef HAVE_MF_HC4 266 case LZMA_MF_HC4: 267 mf->find = &lzma_mf_hc4_find; 268 mf->skip = &lzma_mf_hc4_skip; 269 break; 270#endif 271#ifdef HAVE_MF_BT2 272 case LZMA_MF_BT2: 273 mf->find = &lzma_mf_bt2_find; 274 mf->skip = &lzma_mf_bt2_skip; 275 break; 276#endif 277#ifdef HAVE_MF_BT3 278 case LZMA_MF_BT3: 279 mf->find = &lzma_mf_bt3_find; 280 mf->skip = &lzma_mf_bt3_skip; 281 break; 282#endif 283#ifdef HAVE_MF_BT4 284 case LZMA_MF_BT4: 285 mf->find = &lzma_mf_bt4_find; 286 mf->skip = &lzma_mf_bt4_skip; 287 break; 288#endif 289 290 default: 291 return true; 292 } 293 294 // Calculate the sizes of mf->hash and mf->son and check that 295 // nice_len is big enough for the selected match finder. 296 const uint32_t hash_bytes = lz_options->match_finder & 0x0F; 297 if (hash_bytes > mf->nice_len) 298 return true; 299 300 const bool is_bt = (lz_options->match_finder & 0x10) != 0; 301 uint32_t hs; 302 303 if (hash_bytes == 2) { 304 hs = 0xFFFF; 305 } else { 306 // Round dictionary size up to the next 2^n - 1 so it can 307 // be used as a hash mask. 308 hs = lz_options->dict_size - 1; 309 hs |= hs >> 1; 310 hs |= hs >> 2; 311 hs |= hs >> 4; 312 hs |= hs >> 8; 313 hs >>= 1; 314 hs |= 0xFFFF; 315 316 if (hs > (UINT32_C(1) << 24)) { 317 if (hash_bytes == 3) 318 hs = (UINT32_C(1) << 24) - 1; 319 else 320 hs >>= 1; 321 } 322 } 323 324 mf->hash_mask = hs; 325 326 ++hs; 327 if (hash_bytes > 2) 328 hs += HASH_2_SIZE; 329 if (hash_bytes > 3) 330 hs += HASH_3_SIZE; 331/* 332 No match finder uses this at the moment. 333 if (mf->hash_bytes > 4) 334 hs += HASH_4_SIZE; 335*/ 336 337 const uint32_t old_hash_count = mf->hash_count; 338 const uint32_t old_sons_count = mf->sons_count; 339 mf->hash_count = hs; 340 mf->sons_count = mf->cyclic_size; 341 if (is_bt) 342 mf->sons_count *= 2; 343 344 // Deallocate the old hash array if it exists and has different size 345 // than what is needed now. 346 if (old_hash_count != mf->hash_count 347 || old_sons_count != mf->sons_count) { 348 lzma_free(mf->hash, allocator); 349 mf->hash = NULL; 350 351 lzma_free(mf->son, allocator); 352 mf->son = NULL; 353 } 354 355 // Maximum number of match finder cycles 356 mf->depth = lz_options->depth; 357 if (mf->depth == 0) { 358 if (is_bt) 359 mf->depth = 16 + mf->nice_len / 2; 360 else 361 mf->depth = 4 + mf->nice_len / 4; 362 } 363 364 return false; 365} 366 367 368static bool 369lz_encoder_init(lzma_mf *mf, const lzma_allocator *allocator, 370 const lzma_lz_options *lz_options) 371{ 372 // Allocate the history buffer. 373 if (mf->buffer == NULL) { 374 // lzma_memcmplen() is used for the dictionary buffer 375 // so we need to allocate a few extra bytes to prevent 376 // it from reading past the end of the buffer. 377 mf->buffer = lzma_alloc(mf->size + LZMA_MEMCMPLEN_EXTRA, 378 allocator); 379 if (mf->buffer == NULL) 380 return true; 381 382 // Keep Valgrind happy with lzma_memcmplen() and initialize 383 // the extra bytes whose value may get read but which will 384 // effectively get ignored. 385 memzero(mf->buffer + mf->size, LZMA_MEMCMPLEN_EXTRA); 386 } 387 388 // Use cyclic_size as initial mf->offset. This allows 389 // avoiding a few branches in the match finders. The downside is 390 // that match finder needs to be normalized more often, which may 391 // hurt performance with huge dictionaries. 392 mf->offset = mf->cyclic_size; 393 mf->read_pos = 0; 394 mf->read_ahead = 0; 395 mf->read_limit = 0; 396 mf->write_pos = 0; 397 mf->pending = 0; 398 399#if UINT32_MAX >= SIZE_MAX / 4 400 // Check for integer overflow. (Huge dictionaries are not 401 // possible on 32-bit CPU.) 402 if (mf->hash_count > SIZE_MAX / sizeof(uint32_t) 403 || mf->sons_count > SIZE_MAX / sizeof(uint32_t)) 404 return true; 405#endif 406 407 // Allocate and initialize the hash table. Since EMPTY_HASH_VALUE 408 // is zero, we can use lzma_alloc_zero() or memzero() for mf->hash. 409 // 410 // We don't need to initialize mf->son, but not doing that may 411 // make Valgrind complain in normalization (see normalize() in 412 // lz_encoder_mf.c). Skipping the initialization is *very* good 413 // when big dictionary is used but only small amount of data gets 414 // actually compressed: most of the mf->son won't get actually 415 // allocated by the kernel, so we avoid wasting RAM and improve 416 // initialization speed a lot. 417 if (mf->hash == NULL) { 418 mf->hash = lzma_alloc_zero(mf->hash_count * sizeof(uint32_t), 419 allocator); 420 mf->son = lzma_alloc(mf->sons_count * sizeof(uint32_t), 421 allocator); 422 423 if (mf->hash == NULL || mf->son == NULL) { 424 lzma_free(mf->hash, allocator); 425 mf->hash = NULL; 426 427 lzma_free(mf->son, allocator); 428 mf->son = NULL; 429 430 return true; 431 } 432 } else { 433/* 434 for (uint32_t i = 0; i < mf->hash_count; ++i) 435 mf->hash[i] = EMPTY_HASH_VALUE; 436*/ 437 memzero(mf->hash, mf->hash_count * sizeof(uint32_t)); 438 } 439 440 mf->cyclic_pos = 0; 441 442 // Handle preset dictionary. 443 if (lz_options->preset_dict != NULL 444 && lz_options->preset_dict_size > 0) { 445 // If the preset dictionary is bigger than the actual 446 // dictionary, use only the tail. 447 mf->write_pos = my_min(lz_options->preset_dict_size, mf->size); 448 memcpy(mf->buffer, lz_options->preset_dict 449 + lz_options->preset_dict_size - mf->write_pos, 450 mf->write_pos); 451 mf->action = LZMA_SYNC_FLUSH; 452 mf->skip(mf, mf->write_pos); 453 } 454 455 mf->action = LZMA_RUN; 456 457 return false; 458} 459 460 461extern uint64_t 462lzma_lz_encoder_memusage(const lzma_lz_options *lz_options) 463{ 464 // Old buffers must not exist when calling lz_encoder_prepare(). 465 lzma_mf mf = { 466 .buffer = NULL, 467 .hash = NULL, 468 .son = NULL, 469 .hash_count = 0, 470 .sons_count = 0, 471 }; 472 473 // Setup the size information into mf. 474 if (lz_encoder_prepare(&mf, NULL, lz_options)) 475 return UINT64_MAX; 476 477 // Calculate the memory usage. 478 return ((uint64_t)(mf.hash_count) + mf.sons_count) * sizeof(uint32_t) 479 + mf.size + sizeof(lzma_coder); 480} 481 482 483static void
| 168 while (*out_pos < out_size 169 && (*in_pos < in_size || action != LZMA_RUN)) { 170 // Read more data to coder->mf.buffer if needed. 171 if (coder->mf.action == LZMA_RUN && coder->mf.read_pos 172 >= coder->mf.read_limit) 173 return_if_error(fill_window(coder, allocator, 174 in, in_pos, in_size, action)); 175 176 // Encode 177 const lzma_ret ret = coder->lz.code(coder->lz.coder, 178 &coder->mf, out, out_pos, out_size); 179 if (ret != LZMA_OK) { 180 // Setting this to LZMA_RUN for cases when we are 181 // flushing. It doesn't matter when finishing or if 182 // an error occurred. 183 coder->mf.action = LZMA_RUN; 184 return ret; 185 } 186 } 187 188 return LZMA_OK; 189} 190 191 192static bool 193lz_encoder_prepare(lzma_mf *mf, const lzma_allocator *allocator, 194 const lzma_lz_options *lz_options) 195{ 196 // For now, the dictionary size is limited to 1.5 GiB. This may grow 197 // in the future if needed, but it needs a little more work than just 198 // changing this check. 199 if (lz_options->dict_size < LZMA_DICT_SIZE_MIN 200 || lz_options->dict_size 201 > (UINT32_C(1) << 30) + (UINT32_C(1) << 29) 202 || lz_options->nice_len > lz_options->match_len_max) 203 return true; 204 205 mf->keep_size_before = lz_options->before_size + lz_options->dict_size; 206 207 mf->keep_size_after = lz_options->after_size 208 + lz_options->match_len_max; 209 210 // To avoid constant memmove()s, allocate some extra space. Since 211 // memmove()s become more expensive when the size of the buffer 212 // increases, we reserve more space when a large dictionary is 213 // used to make the memmove() calls rarer. 214 // 215 // This works with dictionaries up to about 3 GiB. If bigger 216 // dictionary is wanted, some extra work is needed: 217 // - Several variables in lzma_mf have to be changed from uint32_t 218 // to size_t. 219 // - Memory usage calculation needs something too, e.g. use uint64_t 220 // for mf->size. 221 uint32_t reserve = lz_options->dict_size / 2; 222 if (reserve > (UINT32_C(1) << 30)) 223 reserve /= 2; 224 225 reserve += (lz_options->before_size + lz_options->match_len_max 226 + lz_options->after_size) / 2 + (UINT32_C(1) << 19); 227 228 const uint32_t old_size = mf->size; 229 mf->size = mf->keep_size_before + reserve + mf->keep_size_after; 230 231 // Deallocate the old history buffer if it exists but has different 232 // size than what is needed now. 233 if (mf->buffer != NULL && old_size != mf->size) { 234 lzma_free(mf->buffer, allocator); 235 mf->buffer = NULL; 236 } 237 238 // Match finder options 239 mf->match_len_max = lz_options->match_len_max; 240 mf->nice_len = lz_options->nice_len; 241 242 // cyclic_size has to stay smaller than 2 Gi. Note that this doesn't 243 // mean limiting dictionary size to less than 2 GiB. With a match 244 // finder that uses multibyte resolution (hashes start at e.g. every 245 // fourth byte), cyclic_size would stay below 2 Gi even when 246 // dictionary size is greater than 2 GiB. 247 // 248 // It would be possible to allow cyclic_size >= 2 Gi, but then we 249 // would need to be careful to use 64-bit types in various places 250 // (size_t could do since we would need bigger than 32-bit address 251 // space anyway). It would also require either zeroing a multigigabyte 252 // buffer at initialization (waste of time and RAM) or allow 253 // normalization in lz_encoder_mf.c to access uninitialized 254 // memory to keep the code simpler. The current way is simple and 255 // still allows pretty big dictionaries, so I don't expect these 256 // limits to change. 257 mf->cyclic_size = lz_options->dict_size + 1; 258 259 // Validate the match finder ID and setup the function pointers. 260 switch (lz_options->match_finder) { 261#ifdef HAVE_MF_HC3 262 case LZMA_MF_HC3: 263 mf->find = &lzma_mf_hc3_find; 264 mf->skip = &lzma_mf_hc3_skip; 265 break; 266#endif 267#ifdef HAVE_MF_HC4 268 case LZMA_MF_HC4: 269 mf->find = &lzma_mf_hc4_find; 270 mf->skip = &lzma_mf_hc4_skip; 271 break; 272#endif 273#ifdef HAVE_MF_BT2 274 case LZMA_MF_BT2: 275 mf->find = &lzma_mf_bt2_find; 276 mf->skip = &lzma_mf_bt2_skip; 277 break; 278#endif 279#ifdef HAVE_MF_BT3 280 case LZMA_MF_BT3: 281 mf->find = &lzma_mf_bt3_find; 282 mf->skip = &lzma_mf_bt3_skip; 283 break; 284#endif 285#ifdef HAVE_MF_BT4 286 case LZMA_MF_BT4: 287 mf->find = &lzma_mf_bt4_find; 288 mf->skip = &lzma_mf_bt4_skip; 289 break; 290#endif 291 292 default: 293 return true; 294 } 295 296 // Calculate the sizes of mf->hash and mf->son and check that 297 // nice_len is big enough for the selected match finder. 298 const uint32_t hash_bytes = lz_options->match_finder & 0x0F; 299 if (hash_bytes > mf->nice_len) 300 return true; 301 302 const bool is_bt = (lz_options->match_finder & 0x10) != 0; 303 uint32_t hs; 304 305 if (hash_bytes == 2) { 306 hs = 0xFFFF; 307 } else { 308 // Round dictionary size up to the next 2^n - 1 so it can 309 // be used as a hash mask. 310 hs = lz_options->dict_size - 1; 311 hs |= hs >> 1; 312 hs |= hs >> 2; 313 hs |= hs >> 4; 314 hs |= hs >> 8; 315 hs >>= 1; 316 hs |= 0xFFFF; 317 318 if (hs > (UINT32_C(1) << 24)) { 319 if (hash_bytes == 3) 320 hs = (UINT32_C(1) << 24) - 1; 321 else 322 hs >>= 1; 323 } 324 } 325 326 mf->hash_mask = hs; 327 328 ++hs; 329 if (hash_bytes > 2) 330 hs += HASH_2_SIZE; 331 if (hash_bytes > 3) 332 hs += HASH_3_SIZE; 333/* 334 No match finder uses this at the moment. 335 if (mf->hash_bytes > 4) 336 hs += HASH_4_SIZE; 337*/ 338 339 const uint32_t old_hash_count = mf->hash_count; 340 const uint32_t old_sons_count = mf->sons_count; 341 mf->hash_count = hs; 342 mf->sons_count = mf->cyclic_size; 343 if (is_bt) 344 mf->sons_count *= 2; 345 346 // Deallocate the old hash array if it exists and has different size 347 // than what is needed now. 348 if (old_hash_count != mf->hash_count 349 || old_sons_count != mf->sons_count) { 350 lzma_free(mf->hash, allocator); 351 mf->hash = NULL; 352 353 lzma_free(mf->son, allocator); 354 mf->son = NULL; 355 } 356 357 // Maximum number of match finder cycles 358 mf->depth = lz_options->depth; 359 if (mf->depth == 0) { 360 if (is_bt) 361 mf->depth = 16 + mf->nice_len / 2; 362 else 363 mf->depth = 4 + mf->nice_len / 4; 364 } 365 366 return false; 367} 368 369 370static bool 371lz_encoder_init(lzma_mf *mf, const lzma_allocator *allocator, 372 const lzma_lz_options *lz_options) 373{ 374 // Allocate the history buffer. 375 if (mf->buffer == NULL) { 376 // lzma_memcmplen() is used for the dictionary buffer 377 // so we need to allocate a few extra bytes to prevent 378 // it from reading past the end of the buffer. 379 mf->buffer = lzma_alloc(mf->size + LZMA_MEMCMPLEN_EXTRA, 380 allocator); 381 if (mf->buffer == NULL) 382 return true; 383 384 // Keep Valgrind happy with lzma_memcmplen() and initialize 385 // the extra bytes whose value may get read but which will 386 // effectively get ignored. 387 memzero(mf->buffer + mf->size, LZMA_MEMCMPLEN_EXTRA); 388 } 389 390 // Use cyclic_size as initial mf->offset. This allows 391 // avoiding a few branches in the match finders. The downside is 392 // that match finder needs to be normalized more often, which may 393 // hurt performance with huge dictionaries. 394 mf->offset = mf->cyclic_size; 395 mf->read_pos = 0; 396 mf->read_ahead = 0; 397 mf->read_limit = 0; 398 mf->write_pos = 0; 399 mf->pending = 0; 400 401#if UINT32_MAX >= SIZE_MAX / 4 402 // Check for integer overflow. (Huge dictionaries are not 403 // possible on 32-bit CPU.) 404 if (mf->hash_count > SIZE_MAX / sizeof(uint32_t) 405 || mf->sons_count > SIZE_MAX / sizeof(uint32_t)) 406 return true; 407#endif 408 409 // Allocate and initialize the hash table. Since EMPTY_HASH_VALUE 410 // is zero, we can use lzma_alloc_zero() or memzero() for mf->hash. 411 // 412 // We don't need to initialize mf->son, but not doing that may 413 // make Valgrind complain in normalization (see normalize() in 414 // lz_encoder_mf.c). Skipping the initialization is *very* good 415 // when big dictionary is used but only small amount of data gets 416 // actually compressed: most of the mf->son won't get actually 417 // allocated by the kernel, so we avoid wasting RAM and improve 418 // initialization speed a lot. 419 if (mf->hash == NULL) { 420 mf->hash = lzma_alloc_zero(mf->hash_count * sizeof(uint32_t), 421 allocator); 422 mf->son = lzma_alloc(mf->sons_count * sizeof(uint32_t), 423 allocator); 424 425 if (mf->hash == NULL || mf->son == NULL) { 426 lzma_free(mf->hash, allocator); 427 mf->hash = NULL; 428 429 lzma_free(mf->son, allocator); 430 mf->son = NULL; 431 432 return true; 433 } 434 } else { 435/* 436 for (uint32_t i = 0; i < mf->hash_count; ++i) 437 mf->hash[i] = EMPTY_HASH_VALUE; 438*/ 439 memzero(mf->hash, mf->hash_count * sizeof(uint32_t)); 440 } 441 442 mf->cyclic_pos = 0; 443 444 // Handle preset dictionary. 445 if (lz_options->preset_dict != NULL 446 && lz_options->preset_dict_size > 0) { 447 // If the preset dictionary is bigger than the actual 448 // dictionary, use only the tail. 449 mf->write_pos = my_min(lz_options->preset_dict_size, mf->size); 450 memcpy(mf->buffer, lz_options->preset_dict 451 + lz_options->preset_dict_size - mf->write_pos, 452 mf->write_pos); 453 mf->action = LZMA_SYNC_FLUSH; 454 mf->skip(mf, mf->write_pos); 455 } 456 457 mf->action = LZMA_RUN; 458 459 return false; 460} 461 462 463extern uint64_t 464lzma_lz_encoder_memusage(const lzma_lz_options *lz_options) 465{ 466 // Old buffers must not exist when calling lz_encoder_prepare(). 467 lzma_mf mf = { 468 .buffer = NULL, 469 .hash = NULL, 470 .son = NULL, 471 .hash_count = 0, 472 .sons_count = 0, 473 }; 474 475 // Setup the size information into mf. 476 if (lz_encoder_prepare(&mf, NULL, lz_options)) 477 return UINT64_MAX; 478 479 // Calculate the memory usage. 480 return ((uint64_t)(mf.hash_count) + mf.sons_count) * sizeof(uint32_t) 481 + mf.size + sizeof(lzma_coder); 482} 483 484 485static void
|
484lz_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
| 486lz_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
|
485{
| 487{
|
| 488 lzma_coder *coder = coder_ptr; 489
|
486 lzma_next_end(&coder->next, allocator); 487 488 lzma_free(coder->mf.son, allocator); 489 lzma_free(coder->mf.hash, allocator); 490 lzma_free(coder->mf.buffer, allocator); 491 492 if (coder->lz.end != NULL) 493 coder->lz.end(coder->lz.coder, allocator); 494 else 495 lzma_free(coder->lz.coder, allocator); 496 497 lzma_free(coder, allocator); 498 return; 499} 500 501 502static lzma_ret
| 490 lzma_next_end(&coder->next, allocator); 491 492 lzma_free(coder->mf.son, allocator); 493 lzma_free(coder->mf.hash, allocator); 494 lzma_free(coder->mf.buffer, allocator); 495 496 if (coder->lz.end != NULL) 497 coder->lz.end(coder->lz.coder, allocator); 498 else 499 lzma_free(coder->lz.coder, allocator); 500 501 lzma_free(coder, allocator); 502 return; 503} 504 505 506static lzma_ret
|
503lz_encoder_update(lzma_coder *coder, const lzma_allocator *allocator,
| 507lz_encoder_update(void *coder_ptr, const lzma_allocator *allocator,
|
504 const lzma_filter *filters_null lzma_attribute((__unused__)), 505 const lzma_filter *reversed_filters) 506{
| 508 const lzma_filter *filters_null lzma_attribute((__unused__)), 509 const lzma_filter *reversed_filters) 510{
|
| 511 lzma_coder *coder = coder_ptr; 512
|
507 if (coder->lz.options_update == NULL) 508 return LZMA_PROG_ERROR; 509 510 return_if_error(coder->lz.options_update( 511 coder->lz.coder, reversed_filters)); 512 513 return lzma_next_filter_update( 514 &coder->next, allocator, reversed_filters + 1); 515} 516 517 518extern lzma_ret 519lzma_lz_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator, 520 const lzma_filter_info *filters, 521 lzma_ret (*lz_init)(lzma_lz_encoder *lz, 522 const lzma_allocator *allocator, const void *options, 523 lzma_lz_options *lz_options)) 524{ 525#ifdef HAVE_SMALL 526 // We need that the CRC32 table has been initialized. 527 lzma_crc32_init(); 528#endif 529 530 // Allocate and initialize the base data structure.
| 513 if (coder->lz.options_update == NULL) 514 return LZMA_PROG_ERROR; 515 516 return_if_error(coder->lz.options_update( 517 coder->lz.coder, reversed_filters)); 518 519 return lzma_next_filter_update( 520 &coder->next, allocator, reversed_filters + 1); 521} 522 523 524extern lzma_ret 525lzma_lz_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator, 526 const lzma_filter_info *filters, 527 lzma_ret (*lz_init)(lzma_lz_encoder *lz, 528 const lzma_allocator *allocator, const void *options, 529 lzma_lz_options *lz_options)) 530{ 531#ifdef HAVE_SMALL 532 // We need that the CRC32 table has been initialized. 533 lzma_crc32_init(); 534#endif 535 536 // Allocate and initialize the base data structure.
|
531 if (next->coder == NULL) { 532 next->coder = lzma_alloc(sizeof(lzma_coder), allocator); 533 if (next->coder == NULL)
| 537 lzma_coder *coder = next->coder; 538 if (coder == NULL) { 539 coder = lzma_alloc(sizeof(lzma_coder), allocator); 540 if (coder == NULL)
|
534 return LZMA_MEM_ERROR; 535
| 541 return LZMA_MEM_ERROR; 542
|
| 543 next->coder = coder;
|
536 next->code = &lz_encode; 537 next->end = &lz_encoder_end; 538 next->update = &lz_encoder_update; 539
| 544 next->code = &lz_encode; 545 next->end = &lz_encoder_end; 546 next->update = &lz_encoder_update; 547
|
540 next->coder->lz.coder = NULL; 541 next->coder->lz.code = NULL; 542 next->coder->lz.end = NULL;
| 548 coder->lz.coder = NULL; 549 coder->lz.code = NULL; 550 coder->lz.end = NULL;
|
543
| 551
|
544 next->coder->mf.buffer = NULL; 545 next->coder->mf.hash = NULL; 546 next->coder->mf.son = NULL; 547 next->coder->mf.hash_count = 0; 548 next->coder->mf.sons_count = 0;
| 552 // mf.size is initialized to silence Valgrind 553 // when used on optimized binaries (GCC may reorder 554 // code in a way that Valgrind gets unhappy). 555 coder->mf.buffer = NULL; 556 coder->mf.size = 0; 557 coder->mf.hash = NULL; 558 coder->mf.son = NULL; 559 coder->mf.hash_count = 0; 560 coder->mf.sons_count = 0;
|
549
| 561
|
550 next->coder->next = LZMA_NEXT_CODER_INIT;
| 562 coder->next = LZMA_NEXT_CODER_INIT;
|
551 } 552 553 // Initialize the LZ-based encoder. 554 lzma_lz_options lz_options;
| 563 } 564 565 // Initialize the LZ-based encoder. 566 lzma_lz_options lz_options;
|
555 return_if_error(lz_init(&next->coder->lz, allocator,
| 567 return_if_error(lz_init(&coder->lz, allocator,
|
556 filters[0].options, &lz_options)); 557
| 568 filters[0].options, &lz_options)); 569
|
558 // Setup the size information into next->coder->mf and deallocate
| 570 // Setup the size information into coder->mf and deallocate
|
559 // old buffers if they have wrong size.
| 571 // old buffers if they have wrong size.
|
560 if (lz_encoder_prepare(&next->coder->mf, allocator, &lz_options))
| 572 if (lz_encoder_prepare(&coder->mf, allocator, &lz_options))
|
561 return LZMA_OPTIONS_ERROR; 562 563 // Allocate new buffers if needed, and do the rest of 564 // the initialization.
| 573 return LZMA_OPTIONS_ERROR; 574 575 // Allocate new buffers if needed, and do the rest of 576 // the initialization.
|
565 if (lz_encoder_init(&next->coder->mf, allocator, &lz_options))
| 577 if (lz_encoder_init(&coder->mf, allocator, &lz_options))
|
566 return LZMA_MEM_ERROR; 567 568 // Initialize the next filter in the chain, if any.
| 578 return LZMA_MEM_ERROR; 579 580 // Initialize the next filter in the chain, if any.
|
569 return lzma_next_filter_init(&next->coder->next, allocator, 570 filters + 1);
| 581 return lzma_next_filter_init(&coder->next, allocator, filters + 1);
|
571} 572 573 574extern LZMA_API(lzma_bool) 575lzma_mf_is_supported(lzma_match_finder mf) 576{ 577 bool ret = false; 578 579#ifdef HAVE_MF_HC3 580 if (mf == LZMA_MF_HC3) 581 ret = true; 582#endif 583 584#ifdef HAVE_MF_HC4 585 if (mf == LZMA_MF_HC4) 586 ret = true; 587#endif 588 589#ifdef HAVE_MF_BT2 590 if (mf == LZMA_MF_BT2) 591 ret = true; 592#endif 593 594#ifdef HAVE_MF_BT3 595 if (mf == LZMA_MF_BT3) 596 ret = true; 597#endif 598 599#ifdef HAVE_MF_BT4 600 if (mf == LZMA_MF_BT4) 601 ret = true; 602#endif 603 604 return ret; 605}
| 582} 583 584 585extern LZMA_API(lzma_bool) 586lzma_mf_is_supported(lzma_match_finder mf) 587{ 588 bool ret = false; 589 590#ifdef HAVE_MF_HC3 591 if (mf == LZMA_MF_HC3) 592 ret = true; 593#endif 594 595#ifdef HAVE_MF_HC4 596 if (mf == LZMA_MF_HC4) 597 ret = true; 598#endif 599 600#ifdef HAVE_MF_BT2 601 if (mf == LZMA_MF_BT2) 602 ret = true; 603#endif 604 605#ifdef HAVE_MF_BT3 606 if (mf == LZMA_MF_BT3) 607 ret = true; 608#endif 609 610#ifdef HAVE_MF_BT4 611 if (mf == LZMA_MF_BT4) 612 ret = true; 613#endif 614 615 return ret; 616}
|