1 /** 2 * \file lzma/container.h 3 * \brief File formats 4 */ 5 6 /* 7 * Author: 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 * See ../lzma.h for information about liblzma as a whole. 13 */ 14 15 #ifndef LZMA_H_INTERNAL 16 # error Never include this file directly. Use <lzma.h> instead. 17 #endif 18 19 20 /************ 21 * Encoding * 22 ************/ 23 24 /** 25 * \brief Default compression preset 26 * 27 * It's not straightforward to recommend a default preset, because in some 28 * cases keeping the resource usage relatively low is more important that 29 * getting the maximum compression ratio. 30 */ 31 #define LZMA_PRESET_DEFAULT UINT32_C(6) 32 33 34 /** 35 * \brief Mask for preset level 36 * 37 * This is useful only if you need to extract the level from the preset 38 * variable. That should be rare. 39 */ 40 #define LZMA_PRESET_LEVEL_MASK UINT32_C(0x1F) 41 42 43 /* 44 * Preset flags 45 * 46 * Currently only one flag is defined. 47 */ 48 49 /** 50 * \brief Extreme compression preset 51 * 52 * This flag modifies the preset to make the encoding significantly slower 53 * while improving the compression ratio only marginally. This is useful 54 * when you don't mind wasting time to get as small result as possible. 55 * 56 * This flag doesn't affect the memory usage requirements of the decoder (at 57 * least not significantly). The memory usage of the encoder may be increased 58 * a little but only at the lowest preset levels (0-3). 59 */ 60 #define LZMA_PRESET_EXTREME (UINT32_C(1) << 31) 61 62 63 /** 64 * \brief Multithreading options 65 */ 66 typedef struct { 67 /** 68 * \brief Flags 69 * 70 * Set this to zero if no flags are wanted. 71 * 72 * Encoder: No flags are currently supported. 73 * 74 * Decoder: Bitwise-or of zero or more of the decoder flags: 75 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK, 76 * LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK, 77 * LZMA_CONCATENATED, LZMA_FAIL_FAST 78 */ 79 uint32_t flags; 80 81 /** 82 * \brief Number of worker threads to use 83 */ 84 uint32_t threads; 85 86 /** 87 * \brief Encoder only: Maximum uncompressed size of a Block 88 * 89 * The encoder will start a new .xz Block every block_size bytes. 90 * Using LZMA_FULL_FLUSH or LZMA_FULL_BARRIER with lzma_code() 91 * the caller may tell liblzma to start a new Block earlier. 92 * 93 * With LZMA2, a recommended block size is 2-4 times the LZMA2 94 * dictionary size. With very small dictionaries, it is recommended 95 * to use at least 1 MiB block size for good compression ratio, even 96 * if this is more than four times the dictionary size. Note that 97 * these are only recommendations for typical use cases; feel free 98 * to use other values. Just keep in mind that using a block size 99 * less than the LZMA2 dictionary size is waste of RAM. 100 * 101 * Set this to 0 to let liblzma choose the block size depending 102 * on the compression options. For LZMA2 it will be 3*dict_size 103 * or 1 MiB, whichever is more. 104 * 105 * For each thread, about 3 * block_size bytes of memory will be 106 * allocated. This may change in later liblzma versions. If so, 107 * the memory usage will probably be reduced, not increased. 108 */ 109 uint64_t block_size; 110 111 /** 112 * \brief Timeout to allow lzma_code() to return early 113 * 114 * Multithreading can make liblzma to consume input and produce 115 * output in a very bursty way: it may first read a lot of input 116 * to fill internal buffers, then no input or output occurs for 117 * a while. 118 * 119 * In single-threaded mode, lzma_code() won't return until it has 120 * either consumed all the input or filled the output buffer. If 121 * this is done in multithreaded mode, it may cause a call 122 * lzma_code() to take even tens of seconds, which isn't acceptable 123 * in all applications. 124 * 125 * To avoid very long blocking times in lzma_code(), a timeout 126 * (in milliseconds) may be set here. If lzma_code() would block 127 * longer than this number of milliseconds, it will return with 128 * LZMA_OK. Reasonable values are 100 ms or more. The xz command 129 * line tool uses 300 ms. 130 * 131 * If long blocking times are fine for you, set timeout to a special 132 * value of 0, which will disable the timeout mechanism and will make 133 * lzma_code() block until all the input is consumed or the output 134 * buffer has been filled. 135 * 136 * \note Even with a timeout, lzma_code() might sometimes take 137 * somewhat long time to return. No timing guarantees 138 * are made. 139 */ 140 uint32_t timeout; 141 142 /** 143 * \brief Encoder only: Compression preset 144 * 145 * The preset is set just like with lzma_easy_encoder(). 146 * The preset is ignored if filters below is non-NULL. 147 */ 148 uint32_t preset; 149 150 /** 151 * \brief Encoder only: Filter chain (alternative to a preset) 152 * 153 * If this is NULL, the preset above is used. Otherwise the preset 154 * is ignored and the filter chain specified here is used. 155 */ 156 const lzma_filter *filters; 157 158 /** 159 * \brief Encoder only: Integrity check type 160 * 161 * See check.h for available checks. The xz command line tool 162 * defaults to LZMA_CHECK_CRC64, which is a good choice if you 163 * are unsure. 164 */ 165 lzma_check check; 166 167 /* 168 * Reserved space to allow possible future extensions without 169 * breaking the ABI. You should not touch these, because the names 170 * of these variables may change. These are and will never be used 171 * with the currently supported options, so it is safe to leave these 172 * uninitialized. 173 */ 174 lzma_reserved_enum reserved_enum1; 175 lzma_reserved_enum reserved_enum2; 176 lzma_reserved_enum reserved_enum3; 177 uint32_t reserved_int1; 178 uint32_t reserved_int2; 179 uint32_t reserved_int3; 180 uint32_t reserved_int4; 181 182 /** 183 * \brief Memory usage limit to reduce the number of threads 184 * 185 * Encoder: Ignored. 186 * 187 * Decoder: 188 * 189 * If the number of threads has been set so high that more than 190 * memlimit_threading bytes of memory would be needed, the number 191 * of threads will be reduced so that the memory usage will not exceed 192 * memlimit_threading bytes. However, if memlimit_threading cannot 193 * be met even in single-threaded mode, then decoding will continue 194 * in single-threaded mode and memlimit_threading may be exceeded 195 * even by a large amount. That is, memlimit_threading will never make 196 * lzma_code() return LZMA_MEMLIMIT_ERROR. To truly cap the memory 197 * usage, see memlimit_stop below. 198 * 199 * Setting memlimit_threading to UINT64_MAX or a similar huge value 200 * means that liblzma is allowed to keep the whole compressed file 201 * and the whole uncompressed file in memory in addition to the memory 202 * needed by the decompressor data structures used by each thread! 203 * In other words, a reasonable value limit must be set here or it 204 * will cause problems sooner or later. If you have no idea what 205 * a reasonable value could be, try lzma_physmem() / 4 as a starting 206 * point. Setting this limit will never prevent decompression of 207 * a file; this will only reduce the number of threads. 208 * 209 * If memlimit_threading is greater than memlimit_stop, then the value 210 * of memlimit_stop will be used for both. 211 */ 212 uint64_t memlimit_threading; 213 214 /** 215 * \brief Memory usage limit that should never be exceeded 216 * 217 * Encoder: Ignored. 218 * 219 * Decoder: If decompressing will need more than this amount of 220 * memory even in the single-threaded mode, then lzma_code() will 221 * return LZMA_MEMLIMIT_ERROR. 222 */ 223 uint64_t memlimit_stop; 224 225 uint64_t reserved_int7; 226 uint64_t reserved_int8; 227 void *reserved_ptr1; 228 void *reserved_ptr2; 229 void *reserved_ptr3; 230 void *reserved_ptr4; 231 232 } lzma_mt; 233 234 235 /** 236 * \brief Calculate approximate memory usage of easy encoder 237 * 238 * This function is a wrapper for lzma_raw_encoder_memusage(). 239 * 240 * \param preset Compression preset (level and possible flags) 241 * 242 * \return Number of bytes of memory required for the given 243 * preset when encoding. If an error occurs, for example 244 * due to unsupported preset, UINT64_MAX is returned. 245 */ 246 extern LZMA_API(uint64_t) lzma_easy_encoder_memusage(uint32_t preset) 247 lzma_nothrow lzma_attr_pure; 248 249 250 /** 251 * \brief Calculate approximate decoder memory usage of a preset 252 * 253 * This function is a wrapper for lzma_raw_decoder_memusage(). 254 * 255 * \param preset Compression preset (level and possible flags) 256 * 257 * \return Number of bytes of memory required to decompress a file 258 * that was compressed using the given preset. If an error 259 * occurs, for example due to unsupported preset, UINT64_MAX 260 * is returned. 261 */ 262 extern LZMA_API(uint64_t) lzma_easy_decoder_memusage(uint32_t preset) 263 lzma_nothrow lzma_attr_pure; 264 265 266 /** 267 * \brief Initialize .xz Stream encoder using a preset number 268 * 269 * This function is intended for those who just want to use the basic features 270 * if liblzma (that is, most developers out there). 271 * 272 * \param strm Pointer to lzma_stream that is at least initialized 273 * with LZMA_STREAM_INIT. 274 * \param preset Compression preset to use. A preset consist of level 275 * number and zero or more flags. Usually flags aren't 276 * used, so preset is simply a number [0, 9] which match 277 * the options -0 ... -9 of the xz command line tool. 278 * Additional flags can be be set using bitwise-or with 279 * the preset level number, e.g. 6 | LZMA_PRESET_EXTREME. 280 * \param check Integrity check type to use. See check.h for available 281 * checks. The xz command line tool defaults to 282 * LZMA_CHECK_CRC64, which is a good choice if you are 283 * unsure. LZMA_CHECK_CRC32 is good too as long as the 284 * uncompressed file is not many gigabytes. 285 * 286 * \return - LZMA_OK: Initialization succeeded. Use lzma_code() to 287 * encode your data. 288 * - LZMA_MEM_ERROR: Memory allocation failed. 289 * - LZMA_OPTIONS_ERROR: The given compression preset is not 290 * supported by this build of liblzma. 291 * - LZMA_UNSUPPORTED_CHECK: The given check type is not 292 * supported by this liblzma build. 293 * - LZMA_PROG_ERROR: One or more of the parameters have values 294 * that will never be valid. For example, strm == NULL. 295 * 296 * If initialization fails (return value is not LZMA_OK), all the memory 297 * allocated for *strm by liblzma is always freed. Thus, there is no need 298 * to call lzma_end() after failed initialization. 299 * 300 * If initialization succeeds, use lzma_code() to do the actual encoding. 301 * Valid values for `action' (the second argument of lzma_code()) are 302 * LZMA_RUN, LZMA_SYNC_FLUSH, LZMA_FULL_FLUSH, and LZMA_FINISH. In future, 303 * there may be compression levels or flags that don't support LZMA_SYNC_FLUSH. 304 */ 305 extern LZMA_API(lzma_ret) lzma_easy_encoder( 306 lzma_stream *strm, uint32_t preset, lzma_check check) 307 lzma_nothrow lzma_attr_warn_unused_result; 308 309 310 /** 311 * \brief Single-call .xz Stream encoding using a preset number 312 * 313 * The maximum required output buffer size can be calculated with 314 * lzma_stream_buffer_bound(). 315 * 316 * \param preset Compression preset to use. See the description 317 * in lzma_easy_encoder(). 318 * \param check Type of the integrity check to calculate from 319 * uncompressed data. 320 * \param allocator lzma_allocator for custom allocator functions. 321 * Set to NULL to use malloc() and free(). 322 * \param in Beginning of the input buffer 323 * \param in_size Size of the input buffer 324 * \param out Beginning of the output buffer 325 * \param out_pos The next byte will be written to out[*out_pos]. 326 * *out_pos is updated only if encoding succeeds. 327 * \param out_size Size of the out buffer; the first byte into 328 * which no data is written to is out[out_size]. 329 * 330 * \return - LZMA_OK: Encoding was successful. 331 * - LZMA_BUF_ERROR: Not enough output buffer space. 332 * - LZMA_UNSUPPORTED_CHECK 333 * - LZMA_OPTIONS_ERROR 334 * - LZMA_MEM_ERROR 335 * - LZMA_DATA_ERROR 336 * - LZMA_PROG_ERROR 337 */ 338 extern LZMA_API(lzma_ret) lzma_easy_buffer_encode( 339 uint32_t preset, lzma_check check, 340 const lzma_allocator *allocator, 341 const uint8_t *in, size_t in_size, 342 uint8_t *out, size_t *out_pos, size_t out_size) lzma_nothrow; 343 344 345 /** 346 * \brief Initialize .xz Stream encoder using a custom filter chain 347 * 348 * \param strm Pointer to properly prepared lzma_stream 349 * \param filters Array of filters. This must be terminated with 350 * filters[n].id = LZMA_VLI_UNKNOWN. See filter.h for 351 * more information. 352 * \param check Type of the integrity check to calculate from 353 * uncompressed data. 354 * 355 * \return - LZMA_OK: Initialization was successful. 356 * - LZMA_MEM_ERROR 357 * - LZMA_UNSUPPORTED_CHECK 358 * - LZMA_OPTIONS_ERROR 359 * - LZMA_PROG_ERROR 360 */ 361 extern LZMA_API(lzma_ret) lzma_stream_encoder(lzma_stream *strm, 362 const lzma_filter *filters, lzma_check check) 363 lzma_nothrow lzma_attr_warn_unused_result; 364 365 366 /** 367 * \brief Calculate approximate memory usage of multithreaded .xz encoder 368 * 369 * Since doing the encoding in threaded mode doesn't affect the memory 370 * requirements of single-threaded decompressor, you can use 371 * lzma_easy_decoder_memusage(options->preset) or 372 * lzma_raw_decoder_memusage(options->filters) to calculate 373 * the decompressor memory requirements. 374 * 375 * \param options Compression options 376 * 377 * \return Number of bytes of memory required for encoding with the 378 * given options. If an error occurs, for example due to 379 * unsupported preset or filter chain, UINT64_MAX is returned. 380 */ 381 extern LZMA_API(uint64_t) lzma_stream_encoder_mt_memusage( 382 const lzma_mt *options) lzma_nothrow lzma_attr_pure; 383 384 385 /** 386 * \brief Initialize multithreaded .xz Stream encoder 387 * 388 * This provides the functionality of lzma_easy_encoder() and 389 * lzma_stream_encoder() as a single function for multithreaded use. 390 * 391 * The supported actions for lzma_code() are LZMA_RUN, LZMA_FULL_FLUSH, 392 * LZMA_FULL_BARRIER, and LZMA_FINISH. Support for LZMA_SYNC_FLUSH might be 393 * added in the future. 394 * 395 * \param strm Pointer to properly prepared lzma_stream 396 * \param options Pointer to multithreaded compression options 397 * 398 * \return - LZMA_OK 399 * - LZMA_MEM_ERROR 400 * - LZMA_UNSUPPORTED_CHECK 401 * - LZMA_OPTIONS_ERROR 402 * - LZMA_PROG_ERROR 403 */ 404 extern LZMA_API(lzma_ret) lzma_stream_encoder_mt( 405 lzma_stream *strm, const lzma_mt *options) 406 lzma_nothrow lzma_attr_warn_unused_result; 407 408 409 /** 410 * \brief Initialize .lzma encoder (legacy file format) 411 * 412 * The .lzma format is sometimes called the LZMA_Alone format, which is the 413 * reason for the name of this function. The .lzma format supports only the 414 * LZMA1 filter. There is no support for integrity checks like CRC32. 415 * 416 * Use this function if and only if you need to create files readable by 417 * legacy LZMA tools such as LZMA Utils 4.32.x. Moving to the .xz format 418 * is strongly recommended. 419 * 420 * The valid action values for lzma_code() are LZMA_RUN and LZMA_FINISH. 421 * No kind of flushing is supported, because the file format doesn't make 422 * it possible. 423 * 424 * \return - LZMA_OK 425 * - LZMA_MEM_ERROR 426 * - LZMA_OPTIONS_ERROR 427 * - LZMA_PROG_ERROR 428 */ 429 extern LZMA_API(lzma_ret) lzma_alone_encoder( 430 lzma_stream *strm, const lzma_options_lzma *options) 431 lzma_nothrow lzma_attr_warn_unused_result; 432 433 434 /** 435 * \brief Calculate output buffer size for single-call Stream encoder 436 * 437 * When trying to compress uncompressible data, the encoded size will be 438 * slightly bigger than the input data. This function calculates how much 439 * output buffer space is required to be sure that lzma_stream_buffer_encode() 440 * doesn't return LZMA_BUF_ERROR. 441 * 442 * The calculated value is not exact, but it is guaranteed to be big enough. 443 * The actual maximum output space required may be slightly smaller (up to 444 * about 100 bytes). This should not be a problem in practice. 445 * 446 * If the calculated maximum size doesn't fit into size_t or would make the 447 * Stream grow past LZMA_VLI_MAX (which should never happen in practice), 448 * zero is returned to indicate the error. 449 * 450 * \note The limit calculated by this function applies only to 451 * single-call encoding. Multi-call encoding may (and probably 452 * will) have larger maximum expansion when encoding 453 * uncompressible data. Currently there is no function to 454 * calculate the maximum expansion of multi-call encoding. 455 */ 456 extern LZMA_API(size_t) lzma_stream_buffer_bound(size_t uncompressed_size) 457 lzma_nothrow; 458 459 460 /** 461 * \brief Single-call .xz Stream encoder 462 * 463 * \param filters Array of filters. This must be terminated with 464 * filters[n].id = LZMA_VLI_UNKNOWN. See filter.h 465 * for more information. 466 * \param check Type of the integrity check to calculate from 467 * uncompressed data. 468 * \param allocator lzma_allocator for custom allocator functions. 469 * Set to NULL to use malloc() and free(). 470 * \param in Beginning of the input buffer 471 * \param in_size Size of the input buffer 472 * \param out Beginning of the output buffer 473 * \param out_pos The next byte will be written to out[*out_pos]. 474 * *out_pos is updated only if encoding succeeds. 475 * \param out_size Size of the out buffer; the first byte into 476 * which no data is written to is out[out_size]. 477 * 478 * \return - LZMA_OK: Encoding was successful. 479 * - LZMA_BUF_ERROR: Not enough output buffer space. 480 * - LZMA_UNSUPPORTED_CHECK 481 * - LZMA_OPTIONS_ERROR 482 * - LZMA_MEM_ERROR 483 * - LZMA_DATA_ERROR 484 * - LZMA_PROG_ERROR 485 */ 486 extern LZMA_API(lzma_ret) lzma_stream_buffer_encode( 487 lzma_filter *filters, lzma_check check, 488 const lzma_allocator *allocator, 489 const uint8_t *in, size_t in_size, 490 uint8_t *out, size_t *out_pos, size_t out_size) 491 lzma_nothrow lzma_attr_warn_unused_result; 492 493 494 /** 495 * \brief MicroLZMA encoder 496 * 497 * The MicroLZMA format is a raw LZMA stream whose first byte (always 0x00) 498 * has been replaced with bitwise-negation of the LZMA properties (lc/lp/pb). 499 * This encoding ensures that the first byte of MicroLZMA stream is never 500 * 0x00. There is no end of payload marker and thus the uncompressed size 501 * must be stored separately. For the best error detection the dictionary 502 * size should be stored separately as well but alternatively one may use 503 * the uncompressed size as the dictionary size when decoding. 504 * 505 * With the MicroLZMA encoder, lzma_code() behaves slightly unusually. 506 * The action argument must be LZMA_FINISH and the return value will never be 507 * LZMA_OK. Thus the encoding is always done with a single lzma_code() after 508 * the initialization. The benefit of the combination of initialization 509 * function and lzma_code() is that memory allocations can be re-used for 510 * better performance. 511 * 512 * lzma_code() will try to encode as much input as is possible to fit into 513 * the given output buffer. If not all input can be encoded, the stream will 514 * be finished without encoding all the input. The caller must check both 515 * input and output buffer usage after lzma_code() (total_in and total_out 516 * in lzma_stream can be convenient). Often lzma_code() can fill the output 517 * buffer completely if there is a lot of input, but sometimes a few bytes 518 * may remain unused because the next LZMA symbol would require more space. 519 * 520 * lzma_stream.avail_out must be at least 6. Otherwise LZMA_PROG_ERROR 521 * will be returned. 522 * 523 * The LZMA dictionary should be reasonably low to speed up the encoder 524 * re-initialization. A good value is bigger than the resulting 525 * uncompressed size of most of the output chunks. For example, if output 526 * size is 4 KiB, dictionary size of 32 KiB or 64 KiB is good. If the 527 * data compresses extremely well, even 128 KiB may be useful. 528 * 529 * The MicroLZMA format and this encoder variant were made with the EROFS 530 * file system in mind. This format may be convenient in other embedded 531 * uses too where many small streams are needed. XZ Embedded includes a 532 * decoder for this format. 533 * 534 * \return - LZMA_STREAM_END: All good. Check the amounts of input used 535 * and output produced. Store the amount of input used 536 * (uncompressed size) as it needs to be known to decompress 537 * the data. 538 * - LZMA_OPTIONS_ERROR 539 * - LZMA_MEM_ERROR 540 * - LZMA_PROG_ERROR: In addition to the generic reasons for this 541 * error code, this may also be returned if there isn't enough 542 * output space (6 bytes) to create a valid MicroLZMA stream. 543 */ 544 extern LZMA_API(lzma_ret) lzma_microlzma_encoder( 545 lzma_stream *strm, const lzma_options_lzma *options); 546 547 548 /************ 549 * Decoding * 550 ************/ 551 552 /** 553 * This flag makes lzma_code() return LZMA_NO_CHECK if the input stream 554 * being decoded has no integrity check. Note that when used with 555 * lzma_auto_decoder(), all .lzma files will trigger LZMA_NO_CHECK 556 * if LZMA_TELL_NO_CHECK is used. 557 */ 558 #define LZMA_TELL_NO_CHECK UINT32_C(0x01) 559 560 561 /** 562 * This flag makes lzma_code() return LZMA_UNSUPPORTED_CHECK if the input 563 * stream has an integrity check, but the type of the integrity check is not 564 * supported by this liblzma version or build. Such files can still be 565 * decoded, but the integrity check cannot be verified. 566 */ 567 #define LZMA_TELL_UNSUPPORTED_CHECK UINT32_C(0x02) 568 569 570 /** 571 * This flag makes lzma_code() return LZMA_GET_CHECK as soon as the type 572 * of the integrity check is known. The type can then be got with 573 * lzma_get_check(). 574 */ 575 #define LZMA_TELL_ANY_CHECK UINT32_C(0x04) 576 577 578 /** 579 * This flag makes lzma_code() not calculate and verify the integrity check 580 * of the compressed data in .xz files. This means that invalid integrity 581 * check values won't be detected and LZMA_DATA_ERROR won't be returned in 582 * such cases. 583 * 584 * This flag only affects the checks of the compressed data itself; the CRC32 585 * values in the .xz headers will still be verified normally. 586 * 587 * Don't use this flag unless you know what you are doing. Possible reasons 588 * to use this flag: 589 * 590 * - Trying to recover data from a corrupt .xz file. 591 * 592 * - Speeding up decompression, which matters mostly with SHA-256 593 * or with files that have compressed extremely well. It's recommended 594 * to not use this flag for this purpose unless the file integrity is 595 * verified externally in some other way. 596 * 597 * Support for this flag was added in liblzma 5.1.4beta. 598 */ 599 #define LZMA_IGNORE_CHECK UINT32_C(0x10) 600 601 602 /** 603 * This flag enables decoding of concatenated files with file formats that 604 * allow concatenating compressed files as is. From the formats currently 605 * supported by liblzma, only the .xz and .lz formats allow concatenated 606 * files. Concatenated files are not allowed with the legacy .lzma format. 607 * 608 * This flag also affects the usage of the `action' argument for lzma_code(). 609 * When LZMA_CONCATENATED is used, lzma_code() won't return LZMA_STREAM_END 610 * unless LZMA_FINISH is used as `action'. Thus, the application has to set 611 * LZMA_FINISH in the same way as it does when encoding. 612 * 613 * If LZMA_CONCATENATED is not used, the decoders still accept LZMA_FINISH 614 * as `action' for lzma_code(), but the usage of LZMA_FINISH isn't required. 615 */ 616 #define LZMA_CONCATENATED UINT32_C(0x08) 617 618 619 /** 620 * This flag makes the threaded decoder report errors (like LZMA_DATA_ERROR) 621 * as soon as they are detected. This saves time when the application has no 622 * interest in a partially decompressed truncated or corrupt file. Note that 623 * due to timing randomness, if the same truncated or corrupt input is 624 * decompressed multiple times with this flag, a different amount of output 625 * may be produced by different runs, and even the error code might vary. 626 * 627 * When using LZMA_FAIL_FAST, it is recommended to use LZMA_FINISH to tell 628 * the decoder when no more input will be coming because it can help fast 629 * detection and reporting of truncated files. Note that in this situation 630 * truncated files might be diagnosed with LZMA_DATA_ERROR instead of 631 * LZMA_OK or LZMA_BUF_ERROR! 632 * 633 * Without this flag the threaded decoder will provide as much output as 634 * possible at first and then report the pending error. This default behavior 635 * matches the single-threaded decoder and provides repeatable behavior 636 * with truncated or corrupt input. There are a few special cases where the 637 * behavior can still differ like memory allocation failures (LZMA_MEM_ERROR). 638 * 639 * Single-threaded decoders currently ignore this flag. 640 * 641 * Support for this flag was added in liblzma 5.3.3alpha. Note that in older 642 * versions this flag isn't supported (LZMA_OPTIONS_ERROR) even by functions 643 * that ignore this flag in newer liblzma versions. 644 */ 645 #define LZMA_FAIL_FAST UINT32_C(0x20) 646 647 648 /** 649 * \brief Initialize .xz Stream decoder 650 * 651 * \param strm Pointer to properly prepared lzma_stream 652 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX 653 * to effectively disable the limiter. liblzma 654 * 5.2.3 and earlier don't allow 0 here and return 655 * LZMA_PROG_ERROR; later versions treat 0 as if 1 656 * had been specified. 657 * \param flags Bitwise-or of zero or more of the decoder flags: 658 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK, 659 * LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK, 660 * LZMA_CONCATENATED, LZMA_FAIL_FAST 661 * 662 * \return - LZMA_OK: Initialization was successful. 663 * - LZMA_MEM_ERROR: Cannot allocate memory. 664 * - LZMA_OPTIONS_ERROR: Unsupported flags 665 * - LZMA_PROG_ERROR 666 */ 667 extern LZMA_API(lzma_ret) lzma_stream_decoder( 668 lzma_stream *strm, uint64_t memlimit, uint32_t flags) 669 lzma_nothrow lzma_attr_warn_unused_result; 670 671 672 /** 673 * \brief Initialize multithreaded .xz Stream decoder 674 * 675 * \param strm Pointer to properly prepared lzma_stream 676 * \param options Pointer to multithreaded compression options 677 * 678 * The decoder can decode multiple Blocks in parallel. This requires that each 679 * Block Header contains the Compressed Size and Uncompressed size fields 680 * which are added by the multi-threaded encoder, see lzma_stream_encoder_mt(). 681 * 682 * A Stream with one Block will only utilize one thread. A Stream with multiple 683 * Blocks but without size information in Block Headers will be processed in 684 * single-threaded mode in the same way as done by lzma_stream_decoder(). 685 * Concatenated Streams are processed one Stream at a time; no inter-Stream 686 * parallelization is done. 687 * 688 * This function behaves like lzma_stream_decoder() when options->threads == 1 689 * and options->memlimit_threading <= 1. 690 * 691 * \return - LZMA_OK: Initialization was successful. 692 * - LZMA_MEM_ERROR: Cannot allocate memory. 693 * - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached. 694 * - LZMA_OPTIONS_ERROR: Unsupported flags. 695 * - LZMA_PROG_ERROR 696 */ 697 extern LZMA_API(lzma_ret) lzma_stream_decoder_mt( 698 lzma_stream *strm, const lzma_mt *options) 699 lzma_nothrow lzma_attr_warn_unused_result; 700 701 702 /** 703 * \brief Decode .xz, .lzma, and .lz (lzip) files with autodetection 704 * 705 * This decoder autodetects between the .xz, .lzma, and .lz file formats, 706 * and calls lzma_stream_decoder(), lzma_alone_decoder(), or 707 * lzma_lzip_decoder() once the type of the input file has been detected. 708 * 709 * Support for .lz was added in 5.4.0. 710 * 711 * If the flag LZMA_CONCATENATED is used and the input is a .lzma file: 712 * For historical reasons concatenated .lzma files aren't supported. 713 * If there is trailing data after one .lzma stream, lzma_code() will 714 * return LZMA_DATA_ERROR. (lzma_alone_decoder() doesn't have such a check 715 * as it doesn't support any decoder flags. It will return LZMA_STREAM_END 716 * after one .lzma stream.) 717 * 718 * \param strm Pointer to properly prepared lzma_stream 719 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX 720 * to effectively disable the limiter. liblzma 721 * 5.2.3 and earlier don't allow 0 here and return 722 * LZMA_PROG_ERROR; later versions treat 0 as if 1 723 * had been specified. 724 * \param flags Bitwise-or of zero or more of the decoder flags: 725 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK, 726 * LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK, 727 * LZMA_CONCATENATED, LZMA_FAIL_FAST 728 * 729 * \return - LZMA_OK: Initialization was successful. 730 * - LZMA_MEM_ERROR: Cannot allocate memory. 731 * - LZMA_OPTIONS_ERROR: Unsupported flags 732 * - LZMA_PROG_ERROR 733 */ 734 extern LZMA_API(lzma_ret) lzma_auto_decoder( 735 lzma_stream *strm, uint64_t memlimit, uint32_t flags) 736 lzma_nothrow lzma_attr_warn_unused_result; 737 738 739 /** 740 * \brief Initialize .lzma decoder (legacy file format) 741 * 742 * \param strm Pointer to properly prepared lzma_stream 743 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX 744 * to effectively disable the limiter. liblzma 745 * 5.2.3 and earlier don't allow 0 here and return 746 * LZMA_PROG_ERROR; later versions treat 0 as if 1 747 * had been specified. 748 * 749 * Valid `action' arguments to lzma_code() are LZMA_RUN and LZMA_FINISH. 750 * There is no need to use LZMA_FINISH, but it's allowed because it may 751 * simplify certain types of applications. 752 * 753 * \return - LZMA_OK 754 * - LZMA_MEM_ERROR 755 * - LZMA_PROG_ERROR 756 */ 757 extern LZMA_API(lzma_ret) lzma_alone_decoder( 758 lzma_stream *strm, uint64_t memlimit) 759 lzma_nothrow lzma_attr_warn_unused_result; 760 761 762 /** 763 * \brief Initialize .lz (lzip) decoder (a foreign file format) 764 * 765 * \param strm Pointer to properly prepared lzma_stream 766 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX 767 * to effectively disable the limiter. 768 * \param flags Bitwise-or of flags, or zero for no flags. 769 * All decoder flags listed above are supported 770 * although only LZMA_CONCATENATED and (in very rare 771 * cases) LZMA_IGNORE_CHECK are actually useful. 772 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK, 773 * and LZMA_FAIL_FAST do nothing. LZMA_TELL_ANY_CHECK 774 * is supported for consistency only as CRC32 is 775 * always used in the .lz format. 776 * 777 * This decoder supports the .lz format version 0 and the unextended .lz 778 * format version 1: 779 * 780 * - Files in the format version 0 were produced by lzip 1.3 and older. 781 * Such files aren't common but may be found from file archives 782 * as a few source packages were released in this format. People 783 * might have old personal files in this format too. Decompression 784 * support for the format version 0 was removed in lzip 1.18. 785 * 786 * - lzip 1.3 added decompression support for .lz format version 1 files. 787 * Compression support was added in lzip 1.4. In lzip 1.6 the .lz format 788 * version 1 was extended to support the Sync Flush marker. This extension 789 * is not supported by liblzma. lzma_code() will return LZMA_DATA_ERROR 790 * at the location of the Sync Flush marker. In practice files with 791 * the Sync Flush marker are very rare and thus liblzma can decompress 792 * almost all .lz files. 793 * 794 * Just like with lzma_stream_decoder() for .xz files, LZMA_CONCATENATED 795 * should be used when decompressing normal standalone .lz files. 796 * 797 * The .lz format allows putting non-.lz data at the end of a file after at 798 * least one valid .lz member. That is, one can append custom data at the end 799 * of a .lz file and the decoder is required to ignore it. In liblzma this 800 * is relevant only when LZMA_CONCATENATED is used. In that case lzma_code() 801 * will return LZMA_STREAM_END and leave lzma_stream.next_in pointing to 802 * the first byte of the non-.lz data. An exception to this is if the first 803 * 1-3 bytes of the non-.lz data are identical to the .lz magic bytes 804 * (0x4C, 0x5A, 0x49, 0x50; "LZIP" in US-ASCII). In such a case the 1-3 bytes 805 * will have been ignored by lzma_code(). If one wishes to locate the non-.lz 806 * data reliably, one must ensure that the first byte isn't 0x4C. Actually 807 * one should ensure that none of the first four bytes of trailing data are 808 * equal to the magic bytes because lzip >= 1.20 requires it by default. 809 * 810 * \return - LZMA_OK: Initialization was successful. 811 * - LZMA_MEM_ERROR: Cannot allocate memory. 812 * - LZMA_OPTIONS_ERROR: Unsupported flags 813 * - LZMA_PROG_ERROR 814 */ 815 extern LZMA_API(lzma_ret) lzma_lzip_decoder( 816 lzma_stream *strm, uint64_t memlimit, uint32_t flags) 817 lzma_nothrow lzma_attr_warn_unused_result; 818 819 820 /** 821 * \brief Single-call .xz Stream decoder 822 * 823 * \param memlimit Pointer to how much memory the decoder is allowed 824 * to allocate. The value pointed by this pointer is 825 * modified if and only if LZMA_MEMLIMIT_ERROR is 826 * returned. 827 * \param flags Bitwise-or of zero or more of the decoder flags: 828 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK, 829 * LZMA_IGNORE_CHECK, LZMA_CONCATENATED, 830 * LZMA_FAIL_FAST. Note that LZMA_TELL_ANY_CHECK 831 * is not allowed and will return LZMA_PROG_ERROR. 832 * \param allocator lzma_allocator for custom allocator functions. 833 * Set to NULL to use malloc() and free(). 834 * \param in Beginning of the input buffer 835 * \param in_pos The next byte will be read from in[*in_pos]. 836 * *in_pos is updated only if decoding succeeds. 837 * \param in_size Size of the input buffer; the first byte that 838 * won't be read is in[in_size]. 839 * \param out Beginning of the output buffer 840 * \param out_pos The next byte will be written to out[*out_pos]. 841 * *out_pos is updated only if decoding succeeds. 842 * \param out_size Size of the out buffer; the first byte into 843 * which no data is written to is out[out_size]. 844 * 845 * \return - LZMA_OK: Decoding was successful. 846 * - LZMA_FORMAT_ERROR 847 * - LZMA_OPTIONS_ERROR 848 * - LZMA_DATA_ERROR 849 * - LZMA_NO_CHECK: This can be returned only if using 850 * the LZMA_TELL_NO_CHECK flag. 851 * - LZMA_UNSUPPORTED_CHECK: This can be returned only if using 852 * the LZMA_TELL_UNSUPPORTED_CHECK flag. 853 * - LZMA_MEM_ERROR 854 * - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached. 855 * The minimum required memlimit value was stored to *memlimit. 856 * - LZMA_BUF_ERROR: Output buffer was too small. 857 * - LZMA_PROG_ERROR 858 */ 859 extern LZMA_API(lzma_ret) lzma_stream_buffer_decode( 860 uint64_t *memlimit, uint32_t flags, 861 const lzma_allocator *allocator, 862 const uint8_t *in, size_t *in_pos, size_t in_size, 863 uint8_t *out, size_t *out_pos, size_t out_size) 864 lzma_nothrow lzma_attr_warn_unused_result; 865 866 867 /** 868 * \brief MicroLZMA decoder 869 * 870 * See lzma_microlzma_decoder() for more information. 871 * 872 * The lzma_code() usage with this decoder is completely normal. The 873 * special behavior of lzma_code() applies to lzma_microlzma_encoder() only. 874 * 875 * \param strm Pointer to properly prepared lzma_stream 876 * \param comp_size Compressed size of the MicroLZMA stream. 877 * The caller must somehow know this exactly. 878 * \param uncomp_size Uncompressed size of the MicroLZMA stream. 879 * If the exact uncompressed size isn't known, this 880 * can be set to a value that is at most as big as 881 * the exact uncompressed size would be, but then the 882 * next argument uncomp_size_is_exact must be false. 883 * \param uncomp_size_is_exact 884 * If true, uncomp_size must be exactly correct. 885 * This will improve error detection at the end of 886 * the stream. If the exact uncompressed size isn't 887 * known, this must be false. uncomp_size must still 888 * be at most as big as the exact uncompressed size 889 * is. Setting this to false when the exact size is 890 * known will work but error detection at the end of 891 * the stream will be weaker. 892 * \param dict_size LZMA dictionary size that was used when 893 * compressing the data. It is OK to use a bigger 894 * value too but liblzma will then allocate more 895 * memory than would actually be required and error 896 * detection will be slightly worse. (Note that with 897 * the implementation in XZ Embedded it doesn't 898 * affect the memory usage if one specifies bigger 899 * dictionary than actually required.) 900 */ 901 extern LZMA_API(lzma_ret) lzma_microlzma_decoder( 902 lzma_stream *strm, uint64_t comp_size, 903 uint64_t uncomp_size, lzma_bool uncomp_size_is_exact, 904 uint32_t dict_size); 905