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 * No flags are currently supported. 73 */ 74 uint32_t flags; 75 76 /** 77 * \brief Number of worker threads to use 78 */ 79 uint32_t threads; 80 81 /** 82 * \brief Maximum uncompressed size of a Block 83 * 84 * The encoder will start a new .xz Block every block_size bytes. 85 * Using LZMA_FULL_FLUSH or LZMA_FULL_BARRIER with lzma_code() 86 * the caller may tell liblzma to start a new Block earlier. 87 * 88 * With LZMA2, a recommended block size is 2-4 times the LZMA2 89 * dictionary size. With very small dictionaries, it is recommended 90 * to use at least 1 MiB block size for good compression ratio, even 91 * if this is more than four times the dictionary size. Note that 92 * these are only recommendations for typical use cases; feel free 93 * to use other values. Just keep in mind that using a block size 94 * less than the LZMA2 dictionary size is waste of RAM. 95 * 96 * Set this to 0 to let liblzma choose the block size depending 97 * on the compression options. For LZMA2 it will be 3*dict_size 98 * or 1 MiB, whichever is more. 99 * 100 * For each thread, about 3 * block_size bytes of memory will be 101 * allocated. This may change in later liblzma versions. If so, 102 * the memory usage will probably be reduced, not increased. 103 */ 104 uint64_t block_size; 105 106 /** 107 * \brief Timeout to allow lzma_code() to return early 108 * 109 * Multithreading can make liblzma to consume input and produce 110 * output in a very bursty way: it may first read a lot of input 111 * to fill internal buffers, then no input or output occurs for 112 * a while. 113 * 114 * In single-threaded mode, lzma_code() won't return until it has 115 * either consumed all the input or filled the output buffer. If 116 * this is done in multithreaded mode, it may cause a call 117 * lzma_code() to take even tens of seconds, which isn't acceptable 118 * in all applications. 119 * 120 * To avoid very long blocking times in lzma_code(), a timeout 121 * (in milliseconds) may be set here. If lzma_code() would block 122 * longer than this number of milliseconds, it will return with 123 * LZMA_OK. Reasonable values are 100 ms or more. The xz command 124 * line tool uses 300 ms. 125 * 126 * If long blocking times are fine for you, set timeout to a special 127 * value of 0, which will disable the timeout mechanism and will make 128 * lzma_code() block until all the input is consumed or the output 129 * buffer has been filled. 130 * 131 * \note Even with a timeout, lzma_code() might sometimes take 132 * somewhat long time to return. No timing guarantees 133 * are made. 134 */ 135 uint32_t timeout; 136 137 /** 138 * \brief Compression preset (level and possible flags) 139 * 140 * The preset is set just like with lzma_easy_encoder(). 141 * The preset is ignored if filters below is non-NULL. 142 */ 143 uint32_t preset; 144 145 /** 146 * \brief Filter chain (alternative to a preset) 147 * 148 * If this is NULL, the preset above is used. Otherwise the preset 149 * is ignored and the filter chain specified here is used. 150 */ 151 const lzma_filter *filters; 152 153 /** 154 * \brief Integrity check type 155 * 156 * See check.h for available checks. The xz command line tool 157 * defaults to LZMA_CHECK_CRC64, which is a good choice if you 158 * are unsure. 159 */ 160 lzma_check check; 161 162 /* 163 * Reserved space to allow possible future extensions without 164 * breaking the ABI. You should not touch these, because the names 165 * of these variables may change. These are and will never be used 166 * with the currently supported options, so it is safe to leave these 167 * uninitialized. 168 */ 169 lzma_reserved_enum reserved_enum1; 170 lzma_reserved_enum reserved_enum2; 171 lzma_reserved_enum reserved_enum3; 172 uint32_t reserved_int1; 173 uint32_t reserved_int2; 174 uint32_t reserved_int3; 175 uint32_t reserved_int4; 176 uint64_t reserved_int5; 177 uint64_t reserved_int6; 178 uint64_t reserved_int7; 179 uint64_t reserved_int8; 180 void *reserved_ptr1; 181 void *reserved_ptr2; 182 void *reserved_ptr3; 183 void *reserved_ptr4; 184 185 } lzma_mt; 186 187 188 /** 189 * \brief Calculate approximate memory usage of easy encoder 190 * 191 * This function is a wrapper for lzma_raw_encoder_memusage(). 192 * 193 * \param preset Compression preset (level and possible flags) 194 * 195 * \return Number of bytes of memory required for the given 196 * preset when encoding. If an error occurs, for example 197 * due to unsupported preset, UINT64_MAX is returned. 198 */ 199 extern LZMA_API(uint64_t) lzma_easy_encoder_memusage(uint32_t preset) 200 lzma_nothrow lzma_attr_pure; 201 202 203 /** 204 * \brief Calculate approximate decoder memory usage of a preset 205 * 206 * This function is a wrapper for lzma_raw_decoder_memusage(). 207 * 208 * \param preset Compression preset (level and possible flags) 209 * 210 * \return Number of bytes of memory required to decompress a file 211 * that was compressed using the given preset. If an error 212 * occurs, for example due to unsupported preset, UINT64_MAX 213 * is returned. 214 */ 215 extern LZMA_API(uint64_t) lzma_easy_decoder_memusage(uint32_t preset) 216 lzma_nothrow lzma_attr_pure; 217 218 219 /** 220 * \brief Initialize .xz Stream encoder using a preset number 221 * 222 * This function is intended for those who just want to use the basic features 223 * if liblzma (that is, most developers out there). 224 * 225 * \param strm Pointer to lzma_stream that is at least initialized 226 * with LZMA_STREAM_INIT. 227 * \param preset Compression preset to use. A preset consist of level 228 * number and zero or more flags. Usually flags aren't 229 * used, so preset is simply a number [0, 9] which match 230 * the options -0 ... -9 of the xz command line tool. 231 * Additional flags can be be set using bitwise-or with 232 * the preset level number, e.g. 6 | LZMA_PRESET_EXTREME. 233 * \param check Integrity check type to use. See check.h for available 234 * checks. The xz command line tool defaults to 235 * LZMA_CHECK_CRC64, which is a good choice if you are 236 * unsure. LZMA_CHECK_CRC32 is good too as long as the 237 * uncompressed file is not many gigabytes. 238 * 239 * \return - LZMA_OK: Initialization succeeded. Use lzma_code() to 240 * encode your data. 241 * - LZMA_MEM_ERROR: Memory allocation failed. 242 * - LZMA_OPTIONS_ERROR: The given compression preset is not 243 * supported by this build of liblzma. 244 * - LZMA_UNSUPPORTED_CHECK: The given check type is not 245 * supported by this liblzma build. 246 * - LZMA_PROG_ERROR: One or more of the parameters have values 247 * that will never be valid. For example, strm == NULL. 248 * 249 * If initialization fails (return value is not LZMA_OK), all the memory 250 * allocated for *strm by liblzma is always freed. Thus, there is no need 251 * to call lzma_end() after failed initialization. 252 * 253 * If initialization succeeds, use lzma_code() to do the actual encoding. 254 * Valid values for `action' (the second argument of lzma_code()) are 255 * LZMA_RUN, LZMA_SYNC_FLUSH, LZMA_FULL_FLUSH, and LZMA_FINISH. In future, 256 * there may be compression levels or flags that don't support LZMA_SYNC_FLUSH. 257 */ 258 extern LZMA_API(lzma_ret) lzma_easy_encoder( 259 lzma_stream *strm, uint32_t preset, lzma_check check) 260 lzma_nothrow lzma_attr_warn_unused_result; 261 262 263 /** 264 * \brief Single-call .xz Stream encoding using a preset number 265 * 266 * The maximum required output buffer size can be calculated with 267 * lzma_stream_buffer_bound(). 268 * 269 * \param preset Compression preset to use. See the description 270 * in lzma_easy_encoder(). 271 * \param check Type of the integrity check to calculate from 272 * uncompressed data. 273 * \param allocator lzma_allocator for custom allocator functions. 274 * Set to NULL to use malloc() and free(). 275 * \param in Beginning of the input buffer 276 * \param in_size Size of the input buffer 277 * \param out Beginning of the output buffer 278 * \param out_pos The next byte will be written to out[*out_pos]. 279 * *out_pos is updated only if encoding succeeds. 280 * \param out_size Size of the out buffer; the first byte into 281 * which no data is written to is out[out_size]. 282 * 283 * \return - LZMA_OK: Encoding was successful. 284 * - LZMA_BUF_ERROR: Not enough output buffer space. 285 * - LZMA_UNSUPPORTED_CHECK 286 * - LZMA_OPTIONS_ERROR 287 * - LZMA_MEM_ERROR 288 * - LZMA_DATA_ERROR 289 * - LZMA_PROG_ERROR 290 */ 291 extern LZMA_API(lzma_ret) lzma_easy_buffer_encode( 292 uint32_t preset, lzma_check check, 293 const lzma_allocator *allocator, 294 const uint8_t *in, size_t in_size, 295 uint8_t *out, size_t *out_pos, size_t out_size) lzma_nothrow; 296 297 298 /** 299 * \brief Initialize .xz Stream encoder using a custom filter chain 300 * 301 * \param strm Pointer to properly prepared lzma_stream 302 * \param filters Array of filters. This must be terminated with 303 * filters[n].id = LZMA_VLI_UNKNOWN. See filter.h for 304 * more information. 305 * \param check Type of the integrity check to calculate from 306 * uncompressed data. 307 * 308 * \return - LZMA_OK: Initialization was successful. 309 * - LZMA_MEM_ERROR 310 * - LZMA_UNSUPPORTED_CHECK 311 * - LZMA_OPTIONS_ERROR 312 * - LZMA_PROG_ERROR 313 */ 314 extern LZMA_API(lzma_ret) lzma_stream_encoder(lzma_stream *strm, 315 const lzma_filter *filters, lzma_check check) 316 lzma_nothrow lzma_attr_warn_unused_result; 317 318 319 /** 320 * \brief Calculate approximate memory usage of multithreaded .xz encoder 321 * 322 * Since doing the encoding in threaded mode doesn't affect the memory 323 * requirements of single-threaded decompressor, you can use 324 * lzma_easy_decoder_memusage(options->preset) or 325 * lzma_raw_decoder_memusage(options->filters) to calculate 326 * the decompressor memory requirements. 327 * 328 * \param options Compression options 329 * 330 * \return Number of bytes of memory required for encoding with the 331 * given options. If an error occurs, for example due to 332 * unsupported preset or filter chain, UINT64_MAX is returned. 333 */ 334 extern LZMA_API(uint64_t) lzma_stream_encoder_mt_memusage( 335 const lzma_mt *options) lzma_nothrow lzma_attr_pure; 336 337 338 /** 339 * \brief Initialize multithreaded .xz Stream encoder 340 * 341 * This provides the functionality of lzma_easy_encoder() and 342 * lzma_stream_encoder() as a single function for multithreaded use. 343 * 344 * The supported actions for lzma_code() are LZMA_RUN, LZMA_FULL_FLUSH, 345 * LZMA_FULL_BARRIER, and LZMA_FINISH. Support for LZMA_SYNC_FLUSH might be 346 * added in the future. 347 * 348 * \param strm Pointer to properly prepared lzma_stream 349 * \param options Pointer to multithreaded compression options 350 * 351 * \return - LZMA_OK 352 * - LZMA_MEM_ERROR 353 * - LZMA_UNSUPPORTED_CHECK 354 * - LZMA_OPTIONS_ERROR 355 * - LZMA_PROG_ERROR 356 */ 357 extern LZMA_API(lzma_ret) lzma_stream_encoder_mt( 358 lzma_stream *strm, const lzma_mt *options) 359 lzma_nothrow lzma_attr_warn_unused_result; 360 361 362 /** 363 * \brief Initialize .lzma encoder (legacy file format) 364 * 365 * The .lzma format is sometimes called the LZMA_Alone format, which is the 366 * reason for the name of this function. The .lzma format supports only the 367 * LZMA1 filter. There is no support for integrity checks like CRC32. 368 * 369 * Use this function if and only if you need to create files readable by 370 * legacy LZMA tools such as LZMA Utils 4.32.x. Moving to the .xz format 371 * is strongly recommended. 372 * 373 * The valid action values for lzma_code() are LZMA_RUN and LZMA_FINISH. 374 * No kind of flushing is supported, because the file format doesn't make 375 * it possible. 376 * 377 * \return - LZMA_OK 378 * - LZMA_MEM_ERROR 379 * - LZMA_OPTIONS_ERROR 380 * - LZMA_PROG_ERROR 381 */ 382 extern LZMA_API(lzma_ret) lzma_alone_encoder( 383 lzma_stream *strm, const lzma_options_lzma *options) 384 lzma_nothrow lzma_attr_warn_unused_result; 385 386 387 /** 388 * \brief Calculate output buffer size for single-call Stream encoder 389 * 390 * When trying to compress uncompressible data, the encoded size will be 391 * slightly bigger than the input data. This function calculates how much 392 * output buffer space is required to be sure that lzma_stream_buffer_encode() 393 * doesn't return LZMA_BUF_ERROR. 394 * 395 * The calculated value is not exact, but it is guaranteed to be big enough. 396 * The actual maximum output space required may be slightly smaller (up to 397 * about 100 bytes). This should not be a problem in practice. 398 * 399 * If the calculated maximum size doesn't fit into size_t or would make the 400 * Stream grow past LZMA_VLI_MAX (which should never happen in practice), 401 * zero is returned to indicate the error. 402 * 403 * \note The limit calculated by this function applies only to 404 * single-call encoding. Multi-call encoding may (and probably 405 * will) have larger maximum expansion when encoding 406 * uncompressible data. Currently there is no function to 407 * calculate the maximum expansion of multi-call encoding. 408 */ 409 extern LZMA_API(size_t) lzma_stream_buffer_bound(size_t uncompressed_size) 410 lzma_nothrow; 411 412 413 /** 414 * \brief Single-call .xz Stream encoder 415 * 416 * \param filters Array of filters. This must be terminated with 417 * filters[n].id = LZMA_VLI_UNKNOWN. See filter.h 418 * for more information. 419 * \param check Type of the integrity check to calculate from 420 * uncompressed data. 421 * \param allocator lzma_allocator for custom allocator functions. 422 * Set to NULL to use malloc() and free(). 423 * \param in Beginning of the input buffer 424 * \param in_size Size of the input buffer 425 * \param out Beginning of the output buffer 426 * \param out_pos The next byte will be written to out[*out_pos]. 427 * *out_pos is updated only if encoding succeeds. 428 * \param out_size Size of the out buffer; the first byte into 429 * which no data is written to is out[out_size]. 430 * 431 * \return - LZMA_OK: Encoding was successful. 432 * - LZMA_BUF_ERROR: Not enough output buffer space. 433 * - LZMA_UNSUPPORTED_CHECK 434 * - LZMA_OPTIONS_ERROR 435 * - LZMA_MEM_ERROR 436 * - LZMA_DATA_ERROR 437 * - LZMA_PROG_ERROR 438 */ 439 extern LZMA_API(lzma_ret) lzma_stream_buffer_encode( 440 lzma_filter *filters, lzma_check check, 441 const lzma_allocator *allocator, 442 const uint8_t *in, size_t in_size, 443 uint8_t *out, size_t *out_pos, size_t out_size) 444 lzma_nothrow lzma_attr_warn_unused_result; 445 446 447 /************ 448 * Decoding * 449 ************/ 450 451 /** 452 * This flag makes lzma_code() return LZMA_NO_CHECK if the input stream 453 * being decoded has no integrity check. Note that when used with 454 * lzma_auto_decoder(), all .lzma files will trigger LZMA_NO_CHECK 455 * if LZMA_TELL_NO_CHECK is used. 456 */ 457 #define LZMA_TELL_NO_CHECK UINT32_C(0x01) 458 459 460 /** 461 * This flag makes lzma_code() return LZMA_UNSUPPORTED_CHECK if the input 462 * stream has an integrity check, but the type of the integrity check is not 463 * supported by this liblzma version or build. Such files can still be 464 * decoded, but the integrity check cannot be verified. 465 */ 466 #define LZMA_TELL_UNSUPPORTED_CHECK UINT32_C(0x02) 467 468 469 /** 470 * This flag makes lzma_code() return LZMA_GET_CHECK as soon as the type 471 * of the integrity check is known. The type can then be got with 472 * lzma_get_check(). 473 */ 474 #define LZMA_TELL_ANY_CHECK UINT32_C(0x04) 475 476 477 /** 478 * This flag makes lzma_code() not calculate and verify the integrity check 479 * of the compressed data in .xz files. This means that invalid integrity 480 * check values won't be detected and LZMA_DATA_ERROR won't be returned in 481 * such cases. 482 * 483 * This flag only affects the checks of the compressed data itself; the CRC32 484 * values in the .xz headers will still be verified normally. 485 * 486 * Don't use this flag unless you know what you are doing. Possible reasons 487 * to use this flag: 488 * 489 * - Trying to recover data from a corrupt .xz file. 490 * 491 * - Speeding up decompression, which matters mostly with SHA-256 492 * or with files that have compressed extremely well. It's recommended 493 * to not use this flag for this purpose unless the file integrity is 494 * verified externally in some other way. 495 * 496 * Support for this flag was added in liblzma 5.1.4beta. 497 */ 498 #define LZMA_IGNORE_CHECK UINT32_C(0x10) 499 500 501 /** 502 * This flag enables decoding of concatenated files with file formats that 503 * allow concatenating compressed files as is. From the formats currently 504 * supported by liblzma, only the .xz format allows concatenated files. 505 * Concatenated files are not allowed with the legacy .lzma format. 506 * 507 * This flag also affects the usage of the `action' argument for lzma_code(). 508 * When LZMA_CONCATENATED is used, lzma_code() won't return LZMA_STREAM_END 509 * unless LZMA_FINISH is used as `action'. Thus, the application has to set 510 * LZMA_FINISH in the same way as it does when encoding. 511 * 512 * If LZMA_CONCATENATED is not used, the decoders still accept LZMA_FINISH 513 * as `action' for lzma_code(), but the usage of LZMA_FINISH isn't required. 514 */ 515 #define LZMA_CONCATENATED UINT32_C(0x08) 516 517 518 /** 519 * \brief Initialize .xz Stream decoder 520 * 521 * \param strm Pointer to properly prepared lzma_stream 522 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX 523 * to effectively disable the limiter. 524 * \param flags Bitwise-or of zero or more of the decoder flags: 525 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK, 526 * LZMA_TELL_ANY_CHECK, LZMA_CONCATENATED 527 * 528 * \return - LZMA_OK: Initialization was successful. 529 * - LZMA_MEM_ERROR: Cannot allocate memory. 530 * - LZMA_OPTIONS_ERROR: Unsupported flags 531 * - LZMA_PROG_ERROR 532 */ 533 extern LZMA_API(lzma_ret) lzma_stream_decoder( 534 lzma_stream *strm, uint64_t memlimit, uint32_t flags) 535 lzma_nothrow lzma_attr_warn_unused_result; 536 537 538 /** 539 * \brief Decode .xz Streams and .lzma files with autodetection 540 * 541 * This decoder autodetects between the .xz and .lzma file formats, and 542 * calls lzma_stream_decoder() or lzma_alone_decoder() once the type 543 * of the input file has been detected. 544 * 545 * \param strm Pointer to properly prepared lzma_stream 546 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX 547 * to effectively disable the limiter. 548 * \param flags Bitwise-or of flags, or zero for no flags. 549 * 550 * \return - LZMA_OK: Initialization was successful. 551 * - LZMA_MEM_ERROR: Cannot allocate memory. 552 * - LZMA_OPTIONS_ERROR: Unsupported flags 553 * - LZMA_PROG_ERROR 554 */ 555 extern LZMA_API(lzma_ret) lzma_auto_decoder( 556 lzma_stream *strm, uint64_t memlimit, uint32_t flags) 557 lzma_nothrow lzma_attr_warn_unused_result; 558 559 560 /** 561 * \brief Initialize .lzma decoder (legacy file format) 562 * 563 * Valid `action' arguments to lzma_code() are LZMA_RUN and LZMA_FINISH. 564 * There is no need to use LZMA_FINISH, but allowing it may simplify 565 * certain types of applications. 566 * 567 * \return - LZMA_OK 568 * - LZMA_MEM_ERROR 569 * - LZMA_PROG_ERROR 570 */ 571 extern LZMA_API(lzma_ret) lzma_alone_decoder( 572 lzma_stream *strm, uint64_t memlimit) 573 lzma_nothrow lzma_attr_warn_unused_result; 574 575 576 /** 577 * \brief Single-call .xz Stream decoder 578 * 579 * \param memlimit Pointer to how much memory the decoder is allowed 580 * to allocate. The value pointed by this pointer is 581 * modified if and only if LZMA_MEMLIMIT_ERROR is 582 * returned. 583 * \param flags Bitwise-or of zero or more of the decoder flags: 584 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK, 585 * LZMA_CONCATENATED. Note that LZMA_TELL_ANY_CHECK 586 * is not allowed and will return LZMA_PROG_ERROR. 587 * \param allocator lzma_allocator for custom allocator functions. 588 * Set to NULL to use malloc() and free(). 589 * \param in Beginning of the input buffer 590 * \param in_pos The next byte will be read from in[*in_pos]. 591 * *in_pos is updated only if decoding succeeds. 592 * \param in_size Size of the input buffer; the first byte that 593 * won't be read is in[in_size]. 594 * \param out Beginning of the output buffer 595 * \param out_pos The next byte will be written to out[*out_pos]. 596 * *out_pos is updated only if decoding succeeds. 597 * \param out_size Size of the out buffer; the first byte into 598 * which no data is written to is out[out_size]. 599 * 600 * \return - LZMA_OK: Decoding was successful. 601 * - LZMA_FORMAT_ERROR 602 * - LZMA_OPTIONS_ERROR 603 * - LZMA_DATA_ERROR 604 * - LZMA_NO_CHECK: This can be returned only if using 605 * the LZMA_TELL_NO_CHECK flag. 606 * - LZMA_UNSUPPORTED_CHECK: This can be returned only if using 607 * the LZMA_TELL_UNSUPPORTED_CHECK flag. 608 * - LZMA_MEM_ERROR 609 * - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached. 610 * The minimum required memlimit value was stored to *memlimit. 611 * - LZMA_BUF_ERROR: Output buffer was too small. 612 * - LZMA_PROG_ERROR 613 */ 614 extern LZMA_API(lzma_ret) lzma_stream_buffer_decode( 615 uint64_t *memlimit, uint32_t flags, 616 const lzma_allocator *allocator, 617 const uint8_t *in, size_t *in_pos, size_t in_size, 618 uint8_t *out, size_t *out_pos, size_t out_size) 619 lzma_nothrow lzma_attr_warn_unused_result; 620