2 * \file lzma/container.h
4 * \note Never include this file directly. Use <lzma.h> instead.
10 * This file has been put into the public domain.
11 * You can do whatever you want with this file.
14 #ifndef LZMA_H_INTERNAL
15 # error Never include this file directly. Use <lzma.h> instead.
24 * \brief Default compression preset
26 * It's not straightforward to recommend a default preset, because in some
27 * cases keeping the resource usage relatively low is more important that
28 * getting the maximum compression ratio.
30 #define LZMA_PRESET_DEFAULT UINT32_C(6)
34 * \brief Mask for preset level
36 * This is useful only if you need to extract the level from the preset
37 * variable. That should be rare.
39 #define LZMA_PRESET_LEVEL_MASK UINT32_C(0x1F)
45 * Currently only one flag is defined.
49 * \brief Extreme compression preset
51 * This flag modifies the preset to make the encoding significantly slower
52 * while improving the compression ratio only marginally. This is useful
53 * when you don't mind spending time to get as small result as possible.
55 * This flag doesn't affect the memory usage requirements of the decoder (at
56 * least not significantly). The memory usage of the encoder may be increased
57 * a little but only at the lowest preset levels (0-3).
59 #define LZMA_PRESET_EXTREME (UINT32_C(1) << 31)
63 * \brief Multithreading options
69 * Set this to zero if no flags are wanted.
71 * Encoder: No flags are currently supported.
73 * Decoder: Bitwise-or of zero or more of the decoder flags:
74 * - LZMA_TELL_NO_CHECK
75 * - LZMA_TELL_UNSUPPORTED_CHECK
76 * - LZMA_TELL_ANY_CHECK
84 * \brief Number of worker threads to use
89 * \brief Encoder only: Maximum uncompressed size of a Block
91 * The encoder will start a new .xz Block every block_size bytes.
92 * Using LZMA_FULL_FLUSH or LZMA_FULL_BARRIER with lzma_code()
93 * the caller may tell liblzma to start a new Block earlier.
95 * With LZMA2, a recommended block size is 2-4 times the LZMA2
96 * dictionary size. With very small dictionaries, it is recommended
97 * to use at least 1 MiB block size for good compression ratio, even
98 * if this is more than four times the dictionary size. Note that
99 * these are only recommendations for typical use cases; feel free
100 * to use other values. Just keep in mind that using a block size
101 * less than the LZMA2 dictionary size is waste of RAM.
103 * Set this to 0 to let liblzma choose the block size depending
104 * on the compression options. For LZMA2 it will be 3*dict_size
105 * or 1 MiB, whichever is more.
107 * For each thread, about 3 * block_size bytes of memory will be
108 * allocated. This may change in later liblzma versions. If so,
109 * the memory usage will probably be reduced, not increased.
114 * \brief Timeout to allow lzma_code() to return early
116 * Multithreading can make liblzma consume input and produce
117 * output in a very bursty way: it may first read a lot of input
118 * to fill internal buffers, then no input or output occurs for
121 * In single-threaded mode, lzma_code() won't return until it has
122 * either consumed all the input or filled the output buffer. If
123 * this is done in multithreaded mode, it may cause a call
124 * lzma_code() to take even tens of seconds, which isn't acceptable
125 * in all applications.
127 * To avoid very long blocking times in lzma_code(), a timeout
128 * (in milliseconds) may be set here. If lzma_code() would block
129 * longer than this number of milliseconds, it will return with
130 * LZMA_OK. Reasonable values are 100 ms or more. The xz command
131 * line tool uses 300 ms.
133 * If long blocking times are acceptable, set timeout to a special
134 * value of 0. This will disable the timeout mechanism and will make
135 * lzma_code() block until all the input is consumed or the output
136 * buffer has been filled.
138 * \note Even with a timeout, lzma_code() might sometimes take
139 * a long time to return. No timing guarantees are made.
144 * \brief Encoder only: Compression preset
146 * The preset is set just like with lzma_easy_encoder().
147 * The preset is ignored if filters below is non-NULL.
152 * \brief Encoder only: Filter chain (alternative to a preset)
154 * If this is NULL, the preset above is used. Otherwise the preset
155 * is ignored and the filter chain specified here is used.
157 const lzma_filter *filters;
160 * \brief Encoder only: Integrity check type
162 * See check.h for available checks. The xz command line tool
163 * defaults to LZMA_CHECK_CRC64, which is a good choice if you
169 * Reserved space to allow possible future extensions without
170 * breaking the ABI. You should not touch these, because the names
171 * of these variables may change. These are and will never be used
172 * with the currently supported options, so it is safe to leave these
175 /** \private Reserved member. */
176 lzma_reserved_enum reserved_enum1;
178 /** \private Reserved member. */
179 lzma_reserved_enum reserved_enum2;
181 /** \private Reserved member. */
182 lzma_reserved_enum reserved_enum3;
184 /** \private Reserved member. */
185 uint32_t reserved_int1;
187 /** \private Reserved member. */
188 uint32_t reserved_int2;
190 /** \private Reserved member. */
191 uint32_t reserved_int3;
193 /** \private Reserved member. */
194 uint32_t reserved_int4;
197 * \brief Memory usage limit to reduce the number of threads
203 * If the number of threads has been set so high that more than
204 * memlimit_threading bytes of memory would be needed, the number
205 * of threads will be reduced so that the memory usage will not exceed
206 * memlimit_threading bytes. However, if memlimit_threading cannot
207 * be met even in single-threaded mode, then decoding will continue
208 * in single-threaded mode and memlimit_threading may be exceeded
209 * even by a large amount. That is, memlimit_threading will never make
210 * lzma_code() return LZMA_MEMLIMIT_ERROR. To truly cap the memory
211 * usage, see memlimit_stop below.
213 * Setting memlimit_threading to UINT64_MAX or a similar huge value
214 * means that liblzma is allowed to keep the whole compressed file
215 * and the whole uncompressed file in memory in addition to the memory
216 * needed by the decompressor data structures used by each thread!
217 * In other words, a reasonable value limit must be set here or it
218 * will cause problems sooner or later. If you have no idea what
219 * a reasonable value could be, try lzma_physmem() / 4 as a starting
220 * point. Setting this limit will never prevent decompression of
221 * a file; this will only reduce the number of threads.
223 * If memlimit_threading is greater than memlimit_stop, then the value
224 * of memlimit_stop will be used for both.
226 uint64_t memlimit_threading;
229 * \brief Memory usage limit that should never be exceeded
233 * Decoder: If decompressing will need more than this amount of
234 * memory even in the single-threaded mode, then lzma_code() will
235 * return LZMA_MEMLIMIT_ERROR.
237 uint64_t memlimit_stop;
239 /** \private Reserved member. */
240 uint64_t reserved_int7;
242 /** \private Reserved member. */
243 uint64_t reserved_int8;
245 /** \private Reserved member. */
248 /** \private Reserved member. */
251 /** \private Reserved member. */
254 /** \private Reserved member. */
261 * \brief Calculate approximate memory usage of easy encoder
263 * This function is a wrapper for lzma_raw_encoder_memusage().
265 * \param preset Compression preset (level and possible flags)
267 * \return Number of bytes of memory required for the given
268 * preset when encoding or UINT64_MAX on error.
270 extern LZMA_API(uint64_t) lzma_easy_encoder_memusage(uint32_t preset)
271 lzma_nothrow lzma_attr_pure;
275 * \brief Calculate approximate decoder memory usage of a preset
277 * This function is a wrapper for lzma_raw_decoder_memusage().
279 * \param preset Compression preset (level and possible flags)
281 * \return Number of bytes of memory required to decompress a file
282 * that was compressed using the given preset or UINT64_MAX
285 extern LZMA_API(uint64_t) lzma_easy_decoder_memusage(uint32_t preset)
286 lzma_nothrow lzma_attr_pure;
290 * \brief Initialize .xz Stream encoder using a preset number
292 * This function is intended for those who just want to use the basic features
293 * of liblzma (that is, most developers out there).
295 * If initialization fails (return value is not LZMA_OK), all the memory
296 * allocated for *strm by liblzma is always freed. Thus, there is no need
297 * to call lzma_end() after failed initialization.
299 * If initialization succeeds, use lzma_code() to do the actual encoding.
300 * Valid values for `action' (the second argument of lzma_code()) are
301 * LZMA_RUN, LZMA_SYNC_FLUSH, LZMA_FULL_FLUSH, and LZMA_FINISH. In future,
302 * there may be compression levels or flags that don't support LZMA_SYNC_FLUSH.
304 * \param strm Pointer to lzma_stream that is at least initialized
305 * with LZMA_STREAM_INIT.
306 * \param preset Compression preset to use. A preset consist of level
307 * number and zero or more flags. Usually flags aren't
308 * used, so preset is simply a number [0, 9] which match
309 * the options -0 ... -9 of the xz command line tool.
310 * Additional flags can be be set using bitwise-or with
311 * the preset level number, e.g. 6 | LZMA_PRESET_EXTREME.
312 * \param check Integrity check type to use. See check.h for available
313 * checks. The xz command line tool defaults to
314 * LZMA_CHECK_CRC64, which is a good choice if you are
315 * unsure. LZMA_CHECK_CRC32 is good too as long as the
316 * uncompressed file is not many gigabytes.
318 * \return Possible lzma_ret values:
319 * - LZMA_OK: Initialization succeeded. Use lzma_code() to
321 * - LZMA_MEM_ERROR: Memory allocation failed.
322 * - LZMA_OPTIONS_ERROR: The given compression preset is not
323 * supported by this build of liblzma.
324 * - LZMA_UNSUPPORTED_CHECK: The given check type is not
325 * supported by this liblzma build.
326 * - LZMA_PROG_ERROR: One or more of the parameters have values
327 * that will never be valid. For example, strm == NULL.
329 extern LZMA_API(lzma_ret) lzma_easy_encoder(
330 lzma_stream *strm, uint32_t preset, lzma_check check)
331 lzma_nothrow lzma_attr_warn_unused_result;
335 * \brief Single-call .xz Stream encoding using a preset number
337 * The maximum required output buffer size can be calculated with
338 * lzma_stream_buffer_bound().
340 * \param preset Compression preset to use. See the description
341 * in lzma_easy_encoder().
342 * \param check Type of the integrity check to calculate from
344 * \param allocator lzma_allocator for custom allocator functions.
345 * Set to NULL to use malloc() and free().
346 * \param in Beginning of the input buffer
347 * \param in_size Size of the input buffer
348 * \param[out] out Beginning of the output buffer
349 * \param[out] out_pos The next byte will be written to out[*out_pos].
350 * *out_pos is updated only if encoding succeeds.
351 * \param out_size Size of the out buffer; the first byte into
352 * which no data is written to is out[out_size].
354 * \return Possible lzma_ret values:
355 * - LZMA_OK: Encoding was successful.
356 * - LZMA_BUF_ERROR: Not enough output buffer space.
357 * - LZMA_UNSUPPORTED_CHECK
358 * - LZMA_OPTIONS_ERROR
363 extern LZMA_API(lzma_ret) lzma_easy_buffer_encode(
364 uint32_t preset, lzma_check check,
365 const lzma_allocator *allocator,
366 const uint8_t *in, size_t in_size,
367 uint8_t *out, size_t *out_pos, size_t out_size) lzma_nothrow;
371 * \brief Initialize .xz Stream encoder using a custom filter chain
373 * \param strm Pointer to lzma_stream that is at least initialized
374 * with LZMA_STREAM_INIT.
375 * \param filters Array of filters terminated with
376 * .id == LZMA_VLI_UNKNOWN. See filters.h for more
378 * \param check Type of the integrity check to calculate from
381 * \return Possible lzma_ret values:
382 * - LZMA_OK: Initialization was successful.
384 * - LZMA_UNSUPPORTED_CHECK
385 * - LZMA_OPTIONS_ERROR
388 extern LZMA_API(lzma_ret) lzma_stream_encoder(lzma_stream *strm,
389 const lzma_filter *filters, lzma_check check)
390 lzma_nothrow lzma_attr_warn_unused_result;
394 * \brief Calculate approximate memory usage of multithreaded .xz encoder
396 * Since doing the encoding in threaded mode doesn't affect the memory
397 * requirements of single-threaded decompressor, you can use
398 * lzma_easy_decoder_memusage(options->preset) or
399 * lzma_raw_decoder_memusage(options->filters) to calculate
400 * the decompressor memory requirements.
402 * \param options Compression options
404 * \return Number of bytes of memory required for encoding with the
405 * given options. If an error occurs, for example due to
406 * unsupported preset or filter chain, UINT64_MAX is returned.
408 extern LZMA_API(uint64_t) lzma_stream_encoder_mt_memusage(
409 const lzma_mt *options) lzma_nothrow lzma_attr_pure;
413 * \brief Initialize multithreaded .xz Stream encoder
415 * This provides the functionality of lzma_easy_encoder() and
416 * lzma_stream_encoder() as a single function for multithreaded use.
418 * The supported actions for lzma_code() are LZMA_RUN, LZMA_FULL_FLUSH,
419 * LZMA_FULL_BARRIER, and LZMA_FINISH. Support for LZMA_SYNC_FLUSH might be
420 * added in the future.
422 * \param strm Pointer to lzma_stream that is at least initialized
423 * with LZMA_STREAM_INIT.
424 * \param options Pointer to multithreaded compression options
426 * \return Possible lzma_ret values:
429 * - LZMA_UNSUPPORTED_CHECK
430 * - LZMA_OPTIONS_ERROR
433 extern LZMA_API(lzma_ret) lzma_stream_encoder_mt(
434 lzma_stream *strm, const lzma_mt *options)
435 lzma_nothrow lzma_attr_warn_unused_result;
439 * \brief Initialize .lzma encoder (legacy file format)
441 * The .lzma format is sometimes called the LZMA_Alone format, which is the
442 * reason for the name of this function. The .lzma format supports only the
443 * LZMA1 filter. There is no support for integrity checks like CRC32.
445 * Use this function if and only if you need to create files readable by
446 * legacy LZMA tools such as LZMA Utils 4.32.x. Moving to the .xz format
447 * is strongly recommended.
449 * The valid action values for lzma_code() are LZMA_RUN and LZMA_FINISH.
450 * No kind of flushing is supported, because the file format doesn't make
453 * \param strm Pointer to lzma_stream that is at least initialized
454 * with LZMA_STREAM_INIT.
455 * \param options Pointer to encoder options
457 * \return Possible lzma_ret values:
460 * - LZMA_OPTIONS_ERROR
463 extern LZMA_API(lzma_ret) lzma_alone_encoder(
464 lzma_stream *strm, const lzma_options_lzma *options)
465 lzma_nothrow lzma_attr_warn_unused_result;
469 * \brief Calculate output buffer size for single-call Stream encoder
471 * When trying to compress uncompressible data, the encoded size will be
472 * slightly bigger than the input data. This function calculates how much
473 * output buffer space is required to be sure that lzma_stream_buffer_encode()
474 * doesn't return LZMA_BUF_ERROR.
476 * The calculated value is not exact, but it is guaranteed to be big enough.
477 * The actual maximum output space required may be slightly smaller (up to
478 * about 100 bytes). This should not be a problem in practice.
480 * If the calculated maximum size doesn't fit into size_t or would make the
481 * Stream grow past LZMA_VLI_MAX (which should never happen in practice),
482 * zero is returned to indicate the error.
484 * \note The limit calculated by this function applies only to
485 * single-call encoding. Multi-call encoding may (and probably
486 * will) have larger maximum expansion when encoding
487 * uncompressible data. Currently there is no function to
488 * calculate the maximum expansion of multi-call encoding.
490 * \param uncompressed_size Size in bytes of the uncompressed
493 * \return Maximum number of bytes needed to store the compressed data.
495 extern LZMA_API(size_t) lzma_stream_buffer_bound(size_t uncompressed_size)
500 * \brief Single-call .xz Stream encoder
502 * \param filters Array of filters terminated with
503 * .id == LZMA_VLI_UNKNOWN. See filters.h for more
505 * \param check Type of the integrity check to calculate from
507 * \param allocator lzma_allocator for custom allocator functions.
508 * Set to NULL to use malloc() and free().
509 * \param in Beginning of the input buffer
510 * \param in_size Size of the input buffer
511 * \param[out] out Beginning of the output buffer
512 * \param[out] out_pos The next byte will be written to out[*out_pos].
513 * *out_pos is updated only if encoding succeeds.
514 * \param out_size Size of the out buffer; the first byte into
515 * which no data is written to is out[out_size].
517 * \return Possible lzma_ret values:
518 * - LZMA_OK: Encoding was successful.
519 * - LZMA_BUF_ERROR: Not enough output buffer space.
520 * - LZMA_UNSUPPORTED_CHECK
521 * - LZMA_OPTIONS_ERROR
526 extern LZMA_API(lzma_ret) lzma_stream_buffer_encode(
527 lzma_filter *filters, lzma_check check,
528 const lzma_allocator *allocator,
529 const uint8_t *in, size_t in_size,
530 uint8_t *out, size_t *out_pos, size_t out_size)
531 lzma_nothrow lzma_attr_warn_unused_result;
535 * \brief MicroLZMA encoder
537 * The MicroLZMA format is a raw LZMA stream whose first byte (always 0x00)
538 * has been replaced with bitwise-negation of the LZMA properties (lc/lp/pb).
539 * This encoding ensures that the first byte of MicroLZMA stream is never
540 * 0x00. There is no end of payload marker and thus the uncompressed size
541 * must be stored separately. For the best error detection the dictionary
542 * size should be stored separately as well but alternatively one may use
543 * the uncompressed size as the dictionary size when decoding.
545 * With the MicroLZMA encoder, lzma_code() behaves slightly unusually.
546 * The action argument must be LZMA_FINISH and the return value will never be
547 * LZMA_OK. Thus the encoding is always done with a single lzma_code() after
548 * the initialization. The benefit of the combination of initialization
549 * function and lzma_code() is that memory allocations can be re-used for
550 * better performance.
552 * lzma_code() will try to encode as much input as is possible to fit into
553 * the given output buffer. If not all input can be encoded, the stream will
554 * be finished without encoding all the input. The caller must check both
555 * input and output buffer usage after lzma_code() (total_in and total_out
556 * in lzma_stream can be convenient). Often lzma_code() can fill the output
557 * buffer completely if there is a lot of input, but sometimes a few bytes
558 * may remain unused because the next LZMA symbol would require more space.
560 * lzma_stream.avail_out must be at least 6. Otherwise LZMA_PROG_ERROR
563 * The LZMA dictionary should be reasonably low to speed up the encoder
564 * re-initialization. A good value is bigger than the resulting
565 * uncompressed size of most of the output chunks. For example, if output
566 * size is 4 KiB, dictionary size of 32 KiB or 64 KiB is good. If the
567 * data compresses extremely well, even 128 KiB may be useful.
569 * The MicroLZMA format and this encoder variant were made with the EROFS
570 * file system in mind. This format may be convenient in other embedded
571 * uses too where many small streams are needed. XZ Embedded includes a
572 * decoder for this format.
574 * \param strm Pointer to lzma_stream that is at least initialized
575 * with LZMA_STREAM_INIT.
576 * \param options Pointer to encoder options
578 * \return Possible lzma_ret values:
579 * - LZMA_STREAM_END: All good. Check the amounts of input used
580 * and output produced. Store the amount of input used
581 * (uncompressed size) as it needs to be known to decompress
583 * - LZMA_OPTIONS_ERROR
585 * - LZMA_PROG_ERROR: In addition to the generic reasons for this
586 * error code, this may also be returned if there isn't enough
587 * output space (6 bytes) to create a valid MicroLZMA stream.
589 extern LZMA_API(lzma_ret) lzma_microlzma_encoder(
590 lzma_stream *strm, const lzma_options_lzma *options);
598 * This flag makes lzma_code() return LZMA_NO_CHECK if the input stream
599 * being decoded has no integrity check. Note that when used with
600 * lzma_auto_decoder(), all .lzma files will trigger LZMA_NO_CHECK
601 * if LZMA_TELL_NO_CHECK is used.
603 #define LZMA_TELL_NO_CHECK UINT32_C(0x01)
607 * This flag makes lzma_code() return LZMA_UNSUPPORTED_CHECK if the input
608 * stream has an integrity check, but the type of the integrity check is not
609 * supported by this liblzma version or build. Such files can still be
610 * decoded, but the integrity check cannot be verified.
612 #define LZMA_TELL_UNSUPPORTED_CHECK UINT32_C(0x02)
616 * This flag makes lzma_code() return LZMA_GET_CHECK as soon as the type
617 * of the integrity check is known. The type can then be got with
620 #define LZMA_TELL_ANY_CHECK UINT32_C(0x04)
624 * This flag makes lzma_code() not calculate and verify the integrity check
625 * of the compressed data in .xz files. This means that invalid integrity
626 * check values won't be detected and LZMA_DATA_ERROR won't be returned in
629 * This flag only affects the checks of the compressed data itself; the CRC32
630 * values in the .xz headers will still be verified normally.
632 * Don't use this flag unless you know what you are doing. Possible reasons
635 * - Trying to recover data from a corrupt .xz file.
637 * - Speeding up decompression, which matters mostly with SHA-256
638 * or with files that have compressed extremely well. It's recommended
639 * to not use this flag for this purpose unless the file integrity is
640 * verified externally in some other way.
642 * Support for this flag was added in liblzma 5.1.4beta.
644 #define LZMA_IGNORE_CHECK UINT32_C(0x10)
648 * This flag enables decoding of concatenated files with file formats that
649 * allow concatenating compressed files as is. From the formats currently
650 * supported by liblzma, only the .xz and .lz formats allow concatenated
651 * files. Concatenated files are not allowed with the legacy .lzma format.
653 * This flag also affects the usage of the `action' argument for lzma_code().
654 * When LZMA_CONCATENATED is used, lzma_code() won't return LZMA_STREAM_END
655 * unless LZMA_FINISH is used as `action'. Thus, the application has to set
656 * LZMA_FINISH in the same way as it does when encoding.
658 * If LZMA_CONCATENATED is not used, the decoders still accept LZMA_FINISH
659 * as `action' for lzma_code(), but the usage of LZMA_FINISH isn't required.
661 #define LZMA_CONCATENATED UINT32_C(0x08)
665 * This flag makes the threaded decoder report errors (like LZMA_DATA_ERROR)
666 * as soon as they are detected. This saves time when the application has no
667 * interest in a partially decompressed truncated or corrupt file. Note that
668 * due to timing randomness, if the same truncated or corrupt input is
669 * decompressed multiple times with this flag, a different amount of output
670 * may be produced by different runs, and even the error code might vary.
672 * When using LZMA_FAIL_FAST, it is recommended to use LZMA_FINISH to tell
673 * the decoder when no more input will be coming because it can help fast
674 * detection and reporting of truncated files. Note that in this situation
675 * truncated files might be diagnosed with LZMA_DATA_ERROR instead of
676 * LZMA_OK or LZMA_BUF_ERROR!
678 * Without this flag the threaded decoder will provide as much output as
679 * possible at first and then report the pending error. This default behavior
680 * matches the single-threaded decoder and provides repeatable behavior
681 * with truncated or corrupt input. There are a few special cases where the
682 * behavior can still differ like memory allocation failures (LZMA_MEM_ERROR).
684 * Single-threaded decoders currently ignore this flag.
686 * Support for this flag was added in liblzma 5.3.3alpha. Note that in older
687 * versions this flag isn't supported (LZMA_OPTIONS_ERROR) even by functions
688 * that ignore this flag in newer liblzma versions.
690 #define LZMA_FAIL_FAST UINT32_C(0x20)
694 * \brief Initialize .xz Stream decoder
696 * \param strm Pointer to lzma_stream that is at least initialized
697 * with LZMA_STREAM_INIT.
698 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX
699 * to effectively disable the limiter. liblzma
700 * 5.2.3 and earlier don't allow 0 here and return
701 * LZMA_PROG_ERROR; later versions treat 0 as if 1
702 * had been specified.
703 * \param flags Bitwise-or of zero or more of the decoder flags:
704 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
705 * LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK,
706 * LZMA_CONCATENATED, LZMA_FAIL_FAST
708 * \return Possible lzma_ret values:
709 * - LZMA_OK: Initialization was successful.
710 * - LZMA_MEM_ERROR: Cannot allocate memory.
711 * - LZMA_OPTIONS_ERROR: Unsupported flags
714 extern LZMA_API(lzma_ret) lzma_stream_decoder(
715 lzma_stream *strm, uint64_t memlimit, uint32_t flags)
716 lzma_nothrow lzma_attr_warn_unused_result;
720 * \brief Initialize multithreaded .xz Stream decoder
722 * The decoder can decode multiple Blocks in parallel. This requires that each
723 * Block Header contains the Compressed Size and Uncompressed size fields
724 * which are added by the multi-threaded encoder, see lzma_stream_encoder_mt().
726 * A Stream with one Block will only utilize one thread. A Stream with multiple
727 * Blocks but without size information in Block Headers will be processed in
728 * single-threaded mode in the same way as done by lzma_stream_decoder().
729 * Concatenated Streams are processed one Stream at a time; no inter-Stream
730 * parallelization is done.
732 * This function behaves like lzma_stream_decoder() when options->threads == 1
733 * and options->memlimit_threading <= 1.
735 * \param strm Pointer to lzma_stream that is at least initialized
736 * with LZMA_STREAM_INIT.
737 * \param options Pointer to multithreaded compression options
739 * \return Possible lzma_ret values:
740 * - LZMA_OK: Initialization was successful.
741 * - LZMA_MEM_ERROR: Cannot allocate memory.
742 * - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached.
743 * - LZMA_OPTIONS_ERROR: Unsupported flags.
746 extern LZMA_API(lzma_ret) lzma_stream_decoder_mt(
747 lzma_stream *strm, const lzma_mt *options)
748 lzma_nothrow lzma_attr_warn_unused_result;
752 * \brief Decode .xz, .lzma, and .lz (lzip) files with autodetection
754 * This decoder autodetects between the .xz, .lzma, and .lz file formats,
755 * and calls lzma_stream_decoder(), lzma_alone_decoder(), or
756 * lzma_lzip_decoder() once the type of the input file has been detected.
758 * Support for .lz was added in 5.4.0.
760 * If the flag LZMA_CONCATENATED is used and the input is a .lzma file:
761 * For historical reasons concatenated .lzma files aren't supported.
762 * If there is trailing data after one .lzma stream, lzma_code() will
763 * return LZMA_DATA_ERROR. (lzma_alone_decoder() doesn't have such a check
764 * as it doesn't support any decoder flags. It will return LZMA_STREAM_END
765 * after one .lzma stream.)
767 * \param strm Pointer to lzma_stream that is at least initialized
768 * with LZMA_STREAM_INIT.
769 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX
770 * to effectively disable the limiter. liblzma
771 * 5.2.3 and earlier don't allow 0 here and return
772 * LZMA_PROG_ERROR; later versions treat 0 as if 1
773 * had been specified.
774 * \param flags Bitwise-or of zero or more of the decoder flags:
775 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
776 * LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK,
777 * LZMA_CONCATENATED, LZMA_FAIL_FAST
779 * \return Possible lzma_ret values:
780 * - LZMA_OK: Initialization was successful.
781 * - LZMA_MEM_ERROR: Cannot allocate memory.
782 * - LZMA_OPTIONS_ERROR: Unsupported flags
785 extern LZMA_API(lzma_ret) lzma_auto_decoder(
786 lzma_stream *strm, uint64_t memlimit, uint32_t flags)
787 lzma_nothrow lzma_attr_warn_unused_result;
791 * \brief Initialize .lzma decoder (legacy file format)
793 * Valid `action' arguments to lzma_code() are LZMA_RUN and LZMA_FINISH.
794 * There is no need to use LZMA_FINISH, but it's allowed because it may
795 * simplify certain types of applications.
797 * \param strm Pointer to lzma_stream that is at least initialized
798 * with LZMA_STREAM_INIT.
799 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX
800 * to effectively disable the limiter. liblzma
801 * 5.2.3 and earlier don't allow 0 here and return
802 * LZMA_PROG_ERROR; later versions treat 0 as if 1
803 * had been specified.
805 * \return Possible lzma_ret values:
810 extern LZMA_API(lzma_ret) lzma_alone_decoder(
811 lzma_stream *strm, uint64_t memlimit)
812 lzma_nothrow lzma_attr_warn_unused_result;
816 * \brief Initialize .lz (lzip) decoder (a foreign file format)
818 * This decoder supports the .lz format version 0 and the unextended .lz
821 * - Files in the format version 0 were produced by lzip 1.3 and older.
822 * Such files aren't common but may be found from file archives
823 * as a few source packages were released in this format. People
824 * might have old personal files in this format too. Decompression
825 * support for the format version 0 was removed in lzip 1.18.
827 * - lzip 1.3 added decompression support for .lz format version 1 files.
828 * Compression support was added in lzip 1.4. In lzip 1.6 the .lz format
829 * version 1 was extended to support the Sync Flush marker. This extension
830 * is not supported by liblzma. lzma_code() will return LZMA_DATA_ERROR
831 * at the location of the Sync Flush marker. In practice files with
832 * the Sync Flush marker are very rare and thus liblzma can decompress
833 * almost all .lz files.
835 * Just like with lzma_stream_decoder() for .xz files, LZMA_CONCATENATED
836 * should be used when decompressing normal standalone .lz files.
838 * The .lz format allows putting non-.lz data at the end of a file after at
839 * least one valid .lz member. That is, one can append custom data at the end
840 * of a .lz file and the decoder is required to ignore it. In liblzma this
841 * is relevant only when LZMA_CONCATENATED is used. In that case lzma_code()
842 * will return LZMA_STREAM_END and leave lzma_stream.next_in pointing to
843 * the first byte of the non-.lz data. An exception to this is if the first
844 * 1-3 bytes of the non-.lz data are identical to the .lz magic bytes
845 * (0x4C, 0x5A, 0x49, 0x50; "LZIP" in US-ASCII). In such a case the 1-3 bytes
846 * will have been ignored by lzma_code(). If one wishes to locate the non-.lz
847 * data reliably, one must ensure that the first byte isn't 0x4C. Actually
848 * one should ensure that none of the first four bytes of trailing data are
849 * equal to the magic bytes because lzip >= 1.20 requires it by default.
851 * \param strm Pointer to lzma_stream that is at least initialized
852 * with LZMA_STREAM_INIT.
853 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX
854 * to effectively disable the limiter.
855 * \param flags Bitwise-or of flags, or zero for no flags.
856 * All decoder flags listed above are supported
857 * although only LZMA_CONCATENATED and (in very rare
858 * cases) LZMA_IGNORE_CHECK are actually useful.
859 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
860 * and LZMA_FAIL_FAST do nothing. LZMA_TELL_ANY_CHECK
861 * is supported for consistency only as CRC32 is
862 * always used in the .lz format.
864 * \return Possible lzma_ret values:
865 * - LZMA_OK: Initialization was successful.
866 * - LZMA_MEM_ERROR: Cannot allocate memory.
867 * - LZMA_OPTIONS_ERROR: Unsupported flags
870 extern LZMA_API(lzma_ret) lzma_lzip_decoder(
871 lzma_stream *strm, uint64_t memlimit, uint32_t flags)
872 lzma_nothrow lzma_attr_warn_unused_result;
876 * \brief Single-call .xz Stream decoder
878 * \param memlimit Pointer to how much memory the decoder is allowed
879 * to allocate. The value pointed by this pointer is
880 * modified if and only if LZMA_MEMLIMIT_ERROR is
882 * \param flags Bitwise-or of zero or more of the decoder flags:
883 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
884 * LZMA_IGNORE_CHECK, LZMA_CONCATENATED,
885 * LZMA_FAIL_FAST. Note that LZMA_TELL_ANY_CHECK
886 * is not allowed and will return LZMA_PROG_ERROR.
887 * \param allocator lzma_allocator for custom allocator functions.
888 * Set to NULL to use malloc() and free().
889 * \param in Beginning of the input buffer
890 * \param in_pos The next byte will be read from in[*in_pos].
891 * *in_pos is updated only if decoding succeeds.
892 * \param in_size Size of the input buffer; the first byte that
893 * won't be read is in[in_size].
894 * \param[out] out Beginning of the output buffer
895 * \param[out] out_pos The next byte will be written to out[*out_pos].
896 * *out_pos is updated only if decoding succeeds.
897 * \param out_size Size of the out buffer; the first byte into
898 * which no data is written to is out[out_size].
900 * \return Possible lzma_ret values:
901 * - LZMA_OK: Decoding was successful.
902 * - LZMA_FORMAT_ERROR
903 * - LZMA_OPTIONS_ERROR
905 * - LZMA_NO_CHECK: This can be returned only if using
906 * the LZMA_TELL_NO_CHECK flag.
907 * - LZMA_UNSUPPORTED_CHECK: This can be returned only if using
908 * the LZMA_TELL_UNSUPPORTED_CHECK flag.
910 * - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached.
911 * The minimum required memlimit value was stored to *memlimit.
912 * - LZMA_BUF_ERROR: Output buffer was too small.
915 extern LZMA_API(lzma_ret) lzma_stream_buffer_decode(
916 uint64_t *memlimit, uint32_t flags,
917 const lzma_allocator *allocator,
918 const uint8_t *in, size_t *in_pos, size_t in_size,
919 uint8_t *out, size_t *out_pos, size_t out_size)
920 lzma_nothrow lzma_attr_warn_unused_result;
924 * \brief MicroLZMA decoder
926 * See lzma_microlzma_encoder() for more information.
928 * The lzma_code() usage with this decoder is completely normal. The
929 * special behavior of lzma_code() applies to lzma_microlzma_encoder() only.
931 * \param strm Pointer to lzma_stream that is at least initialized
932 * with LZMA_STREAM_INIT.
933 * \param comp_size Compressed size of the MicroLZMA stream.
934 * The caller must somehow know this exactly.
935 * \param uncomp_size Uncompressed size of the MicroLZMA stream.
936 * If the exact uncompressed size isn't known, this
937 * can be set to a value that is at most as big as
938 * the exact uncompressed size would be, but then the
939 * next argument uncomp_size_is_exact must be false.
940 * \param uncomp_size_is_exact
941 * If true, uncomp_size must be exactly correct.
942 * This will improve error detection at the end of
943 * the stream. If the exact uncompressed size isn't
944 * known, this must be false. uncomp_size must still
945 * be at most as big as the exact uncompressed size
946 * is. Setting this to false when the exact size is
947 * known will work but error detection at the end of
948 * the stream will be weaker.
949 * \param dict_size LZMA dictionary size that was used when
950 * compressing the data. It is OK to use a bigger
951 * value too but liblzma will then allocate more
952 * memory than would actually be required and error
953 * detection will be slightly worse. (Note that with
954 * the implementation in XZ Embedded it doesn't
955 * affect the memory usage if one specifies bigger
956 * dictionary than actually required.)
958 * \return Possible lzma_ret values:
961 * - LZMA_OPTIONS_ERROR
964 extern LZMA_API(lzma_ret) lzma_microlzma_decoder(
965 lzma_stream *strm, uint64_t comp_size,
966 uint64_t uncomp_size, lzma_bool uncomp_size_is_exact,