1/**
2 * \file lzma/container.h
3 * \brief File formats
4 * \note Never include this file directly. Use <lzma.h> instead.
5 */
6
7/*
8 * Author: Lasse Collin
9 *
10 * This file has been put into the public domain.
11 * You can do whatever you want with this file.
12 */
13
14#ifndef LZMA_H_INTERNAL
15# error Never include this file directly. Use <lzma.h> instead.
16#endif
17
18
19/************
20 * Encoding *
21 ************/
22
23/**
24 * \brief Default compression preset
25 *
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.
29 */
30#define LZMA_PRESET_DEFAULT UINT32_C(6)
31
32
33/**
34 * \brief Mask for preset level
35 *
36 * This is useful only if you need to extract the level from the preset
37 * variable. That should be rare.
38 */
39#define LZMA_PRESET_LEVEL_MASK UINT32_C(0x1F)
40
41
42/*
43 * Preset flags
44 *
45 * Currently only one flag is defined.
46 */
47
48/**
49 * \brief Extreme compression preset
50 *
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.
54 *
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).
58 */
59#define LZMA_PRESET_EXTREME (UINT32_C(1) << 31)
60
61
62/**
63 * \brief Multithreading options
64 */
65typedef struct {
66 /**
67 * \brief Flags
68 *
69 * Set this to zero if no flags are wanted.
70 *
71 * Encoder: No flags are currently supported.
72 *
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
77 * - LZMA_IGNORE_CHECK
78 * - LZMA_CONCATENATED
79 * - LZMA_FAIL_FAST
80 */
81 uint32_t flags;
82
83 /**
84 * \brief Number of worker threads to use
85 */
86 uint32_t threads;
87
88 /**
89 * \brief Encoder only: Maximum uncompressed size of a Block
90 *
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.
94 *
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.
102 *
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.
106 *
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.
110 */
111 uint64_t block_size;
112
113 /**
114 * \brief Timeout to allow lzma_code() to return early
115 *
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
119 * a while.
120 *
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.
126 *
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.
132 *
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.
137 *
138 * \note Even with a timeout, lzma_code() might sometimes take
139 * a long time to return. No timing guarantees are made.
140 */
141 uint32_t timeout;
142
143 /**
144 * \brief Encoder only: Compression preset
145 *
146 * The preset is set just like with lzma_easy_encoder().
147 * The preset is ignored if filters below is non-NULL.
148 */
149 uint32_t preset;
150
151 /**
152 * \brief Encoder only: Filter chain (alternative to a preset)
153 *
154 * If this is NULL, the preset above is used. Otherwise the preset
155 * is ignored and the filter chain specified here is used.
156 */
157 const lzma_filter *filters;
158
159 /**
160 * \brief Encoder only: Integrity check type
161 *
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
164 * are unsure.
165 */
166 lzma_check check;
167
168 /*
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
173 * uninitialized.
174 */
175 /** \private Reserved member. */
176 lzma_reserved_enum reserved_enum1;
177
178 /** \private Reserved member. */
179 lzma_reserved_enum reserved_enum2;
180
181 /** \private Reserved member. */
182 lzma_reserved_enum reserved_enum3;
183
184 /** \private Reserved member. */
185 uint32_t reserved_int1;
186
187 /** \private Reserved member. */
188 uint32_t reserved_int2;
189
190 /** \private Reserved member. */
191 uint32_t reserved_int3;
192
193 /** \private Reserved member. */
194 uint32_t reserved_int4;
195
196 /**
197 * \brief Memory usage limit to reduce the number of threads
198 *
199 * Encoder: Ignored.
200 *
201 * Decoder:
202 *
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.
212 *
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.
222 *
223 * If memlimit_threading is greater than memlimit_stop, then the value
224 * of memlimit_stop will be used for both.
225 */
226 uint64_t memlimit_threading;
227
228 /**
229 * \brief Memory usage limit that should never be exceeded
230 *
231 * Encoder: Ignored.
232 *
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.
236 */
237 uint64_t memlimit_stop;
238
239 /** \private Reserved member. */
240 uint64_t reserved_int7;
241
242 /** \private Reserved member. */
243 uint64_t reserved_int8;
244
245 /** \private Reserved member. */
246 void *reserved_ptr1;
247
248 /** \private Reserved member. */
249 void *reserved_ptr2;
250
251 /** \private Reserved member. */
252 void *reserved_ptr3;
253
254 /** \private Reserved member. */
255 void *reserved_ptr4;
256
257} lzma_mt;
258
259
260/**
261 * \brief Calculate approximate memory usage of easy encoder
262 *
263 * This function is a wrapper for lzma_raw_encoder_memusage().
264 *
265 * \param preset Compression preset (level and possible flags)
266 *
267 * \return Number of bytes of memory required for the given
268 * preset when encoding or UINT64_MAX on error.
269 */
270extern LZMA_API(uint64_t) lzma_easy_encoder_memusage(uint32_t preset)
271 lzma_nothrow lzma_attr_pure;
272
273
274/**
275 * \brief Calculate approximate decoder memory usage of a preset
276 *
277 * This function is a wrapper for lzma_raw_decoder_memusage().
278 *
279 * \param preset Compression preset (level and possible flags)
280 *
281 * \return Number of bytes of memory required to decompress a file
282 * that was compressed using the given preset or UINT64_MAX
283 * on error.
284 */
285extern LZMA_API(uint64_t) lzma_easy_decoder_memusage(uint32_t preset)
286 lzma_nothrow lzma_attr_pure;
287
288
289/**
290 * \brief Initialize .xz Stream encoder using a preset number
291 *
292 * This function is intended for those who just want to use the basic features
293 * of liblzma (that is, most developers out there).
294 *
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.
298 *
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.
303 *
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.
317 *
318 * \return Possible lzma_ret values:
319 * - LZMA_OK: Initialization succeeded. Use lzma_code() to
320 * encode your data.
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.
328 */
329extern 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;
332
333
334/**
335 * \brief Single-call .xz Stream encoding using a preset number
336 *
337 * The maximum required output buffer size can be calculated with
338 * lzma_stream_buffer_bound().
339 *
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
343 * uncompressed data.
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].
353 *
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
359 * - LZMA_MEM_ERROR
360 * - LZMA_DATA_ERROR
361 * - LZMA_PROG_ERROR
362 */
363extern 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;
368
369
370/**
371 * \brief Initialize .xz Stream encoder using a custom filter chain
372 *
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
377 * information.
378 * \param check Type of the integrity check to calculate from
379 * uncompressed data.
380 *
381 * \return Possible lzma_ret values:
382 * - LZMA_OK: Initialization was successful.
383 * - LZMA_MEM_ERROR
384 * - LZMA_UNSUPPORTED_CHECK
385 * - LZMA_OPTIONS_ERROR
386 * - LZMA_PROG_ERROR
387 */
388extern 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;
391
392
393/**
394 * \brief Calculate approximate memory usage of multithreaded .xz encoder
395 *
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.
401 *
402 * \param options Compression options
403 *
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.
407 */
408extern LZMA_API(uint64_t) lzma_stream_encoder_mt_memusage(
409 const lzma_mt *options) lzma_nothrow lzma_attr_pure;
410
411
412/**
413 * \brief Initialize multithreaded .xz Stream encoder
414 *
415 * This provides the functionality of lzma_easy_encoder() and
416 * lzma_stream_encoder() as a single function for multithreaded use.
417 *
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.
421 *
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
425 *
426 * \return Possible lzma_ret values:
427 * - LZMA_OK
428 * - LZMA_MEM_ERROR
429 * - LZMA_UNSUPPORTED_CHECK
430 * - LZMA_OPTIONS_ERROR
431 * - LZMA_PROG_ERROR
432 */
433extern LZMA_API(lzma_ret) lzma_stream_encoder_mt(
434 lzma_stream *strm, const lzma_mt *options)
435 lzma_nothrow lzma_attr_warn_unused_result;
436
437
438/**
439 * \brief Initialize .lzma encoder (legacy file format)
440 *
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.
444 *
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.
448 *
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
451 * it possible.
452 *
453 * \param strm Pointer to lzma_stream that is at least initialized
454 * with LZMA_STREAM_INIT.
455 * \param options Pointer to encoder options
456 *
457 * \return Possible lzma_ret values:
458 * - LZMA_OK
459 * - LZMA_MEM_ERROR
460 * - LZMA_OPTIONS_ERROR
461 * - LZMA_PROG_ERROR
462 */
463extern LZMA_API(lzma_ret) lzma_alone_encoder(
464 lzma_stream *strm, const lzma_options_lzma *options)
465 lzma_nothrow lzma_attr_warn_unused_result;
466
467
468/**
469 * \brief Calculate output buffer size for single-call Stream encoder
470 *
471 * When trying to compress incompressible 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.
475 *
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.
479 *
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.
483 *
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 * incompressible data. Currently there is no function to
488 * calculate the maximum expansion of multi-call encoding.
489 *
490 * \param uncompressed_size Size in bytes of the uncompressed
491 * input data
492 *
493 * \return Maximum number of bytes needed to store the compressed data.
494 */
495extern LZMA_API(size_t) lzma_stream_buffer_bound(size_t uncompressed_size)
496 lzma_nothrow;
497
498
499/**
500 * \brief Single-call .xz Stream encoder
501 *
502 * \param filters Array of filters terminated with
503 * .id == LZMA_VLI_UNKNOWN. See filters.h for more
504 * information.
505 * \param check Type of the integrity check to calculate from
506 * uncompressed data.
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].
516 *
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
522 * - LZMA_MEM_ERROR
523 * - LZMA_DATA_ERROR
524 * - LZMA_PROG_ERROR
525 */
526extern 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;
532
533
534/**
535 * \brief MicroLZMA encoder
536 *
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.
544 *
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.
551 *
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.
559 *
560 * lzma_stream.avail_out must be at least 6. Otherwise LZMA_PROG_ERROR
561 * will be returned.
562 *
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.
568 *
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.
573 *
574 * \param strm Pointer to lzma_stream that is at least initialized
575 * with LZMA_STREAM_INIT.
576 * \param options Pointer to encoder options
577 *
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
582 * the data.
583 * - LZMA_OPTIONS_ERROR
584 * - LZMA_MEM_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.
588 */
589extern LZMA_API(lzma_ret) lzma_microlzma_encoder(
590 lzma_stream *strm, const lzma_options_lzma *options)
591 lzma_nothrow;
592
593
594/************
595 * Decoding *
596 ************/
597
598/**
599 * This flag makes lzma_code() return LZMA_NO_CHECK if the input stream
600 * being decoded has no integrity check. Note that when used with
601 * lzma_auto_decoder(), all .lzma files will trigger LZMA_NO_CHECK
602 * if LZMA_TELL_NO_CHECK is used.
603 */
604#define LZMA_TELL_NO_CHECK UINT32_C(0x01)
605
606
607/**
608 * This flag makes lzma_code() return LZMA_UNSUPPORTED_CHECK if the input
609 * stream has an integrity check, but the type of the integrity check is not
610 * supported by this liblzma version or build. Such files can still be
611 * decoded, but the integrity check cannot be verified.
612 */
613#define LZMA_TELL_UNSUPPORTED_CHECK UINT32_C(0x02)
614
615
616/**
617 * This flag makes lzma_code() return LZMA_GET_CHECK as soon as the type
618 * of the integrity check is known. The type can then be got with
619 * lzma_get_check().
620 */
621#define LZMA_TELL_ANY_CHECK UINT32_C(0x04)
622
623
624/**
625 * This flag makes lzma_code() not calculate and verify the integrity check
626 * of the compressed data in .xz files. This means that invalid integrity
627 * check values won't be detected and LZMA_DATA_ERROR won't be returned in
628 * such cases.
629 *
630 * This flag only affects the checks of the compressed data itself; the CRC32
631 * values in the .xz headers will still be verified normally.
632 *
633 * Don't use this flag unless you know what you are doing. Possible reasons
634 * to use this flag:
635 *
636 * - Trying to recover data from a corrupt .xz file.
637 *
638 * - Speeding up decompression, which matters mostly with SHA-256
639 * or with files that have compressed extremely well. It's recommended
640 * to not use this flag for this purpose unless the file integrity is
641 * verified externally in some other way.
642 *
643 * Support for this flag was added in liblzma 5.1.4beta.
644 */
645#define LZMA_IGNORE_CHECK UINT32_C(0x10)
646
647
648/**
649 * This flag enables decoding of concatenated files with file formats that
650 * allow concatenating compressed files as is. From the formats currently
651 * supported by liblzma, only the .xz and .lz formats allow concatenated
652 * files. Concatenated files are not allowed with the legacy .lzma format.
653 *
654 * This flag also affects the usage of the `action' argument for lzma_code().
655 * When LZMA_CONCATENATED is used, lzma_code() won't return LZMA_STREAM_END
656 * unless LZMA_FINISH is used as `action'. Thus, the application has to set
657 * LZMA_FINISH in the same way as it does when encoding.
658 *
659 * If LZMA_CONCATENATED is not used, the decoders still accept LZMA_FINISH
660 * as `action' for lzma_code(), but the usage of LZMA_FINISH isn't required.
661 */
662#define LZMA_CONCATENATED UINT32_C(0x08)
663
664
665/**
666 * This flag makes the threaded decoder report errors (like LZMA_DATA_ERROR)
667 * as soon as they are detected. This saves time when the application has no
668 * interest in a partially decompressed truncated or corrupt file. Note that
669 * due to timing randomness, if the same truncated or corrupt input is
670 * decompressed multiple times with this flag, a different amount of output
671 * may be produced by different runs, and even the error code might vary.
672 *
673 * When using LZMA_FAIL_FAST, it is recommended to use LZMA_FINISH to tell
674 * the decoder when no more input will be coming because it can help fast
675 * detection and reporting of truncated files. Note that in this situation
676 * truncated files might be diagnosed with LZMA_DATA_ERROR instead of
677 * LZMA_OK or LZMA_BUF_ERROR!
678 *
679 * Without this flag the threaded decoder will provide as much output as
680 * possible at first and then report the pending error. This default behavior
681 * matches the single-threaded decoder and provides repeatable behavior
682 * with truncated or corrupt input. There are a few special cases where the
683 * behavior can still differ like memory allocation failures (LZMA_MEM_ERROR).
684 *
685 * Single-threaded decoders currently ignore this flag.
686 *
687 * Support for this flag was added in liblzma 5.3.3alpha. Note that in older
688 * versions this flag isn't supported (LZMA_OPTIONS_ERROR) even by functions
689 * that ignore this flag in newer liblzma versions.
690 */
691#define LZMA_FAIL_FAST UINT32_C(0x20)
692
693
694/**
695 * \brief Initialize .xz Stream decoder
696 *
697 * \param strm Pointer to lzma_stream that is at least initialized
698 * with LZMA_STREAM_INIT.
699 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX
700 * to effectively disable the limiter. liblzma
701 * 5.2.3 and earlier don't allow 0 here and return
702 * LZMA_PROG_ERROR; later versions treat 0 as if 1
703 * had been specified.
704 * \param flags Bitwise-or of zero or more of the decoder flags:
705 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
706 * LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK,
707 * LZMA_CONCATENATED, LZMA_FAIL_FAST
708 *
709 * \return Possible lzma_ret values:
710 * - LZMA_OK: Initialization was successful.
711 * - LZMA_MEM_ERROR: Cannot allocate memory.
712 * - LZMA_OPTIONS_ERROR: Unsupported flags
713 * - LZMA_PROG_ERROR
714 */
715extern LZMA_API(lzma_ret) lzma_stream_decoder(
716 lzma_stream *strm, uint64_t memlimit, uint32_t flags)
717 lzma_nothrow lzma_attr_warn_unused_result;
718
719
720/**
721 * \brief Initialize multithreaded .xz Stream decoder
722 *
723 * The decoder can decode multiple Blocks in parallel. This requires that each
724 * Block Header contains the Compressed Size and Uncompressed size fields
725 * which are added by the multi-threaded encoder, see lzma_stream_encoder_mt().
726 *
727 * A Stream with one Block will only utilize one thread. A Stream with multiple
728 * Blocks but without size information in Block Headers will be processed in
729 * single-threaded mode in the same way as done by lzma_stream_decoder().
730 * Concatenated Streams are processed one Stream at a time; no inter-Stream
731 * parallelization is done.
732 *
733 * This function behaves like lzma_stream_decoder() when options->threads == 1
734 * and options->memlimit_threading <= 1.
735 *
736 * \param strm Pointer to lzma_stream that is at least initialized
737 * with LZMA_STREAM_INIT.
738 * \param options Pointer to multithreaded compression options
739 *
740 * \return Possible lzma_ret values:
741 * - LZMA_OK: Initialization was successful.
742 * - LZMA_MEM_ERROR: Cannot allocate memory.
743 * - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached.
744 * - LZMA_OPTIONS_ERROR: Unsupported flags.
745 * - LZMA_PROG_ERROR
746 */
747extern LZMA_API(lzma_ret) lzma_stream_decoder_mt(
748 lzma_stream *strm, const lzma_mt *options)
749 lzma_nothrow lzma_attr_warn_unused_result;
750
751
752/**
753 * \brief Decode .xz, .lzma, and .lz (lzip) files with autodetection
754 *
755 * This decoder autodetects between the .xz, .lzma, and .lz file formats,
756 * and calls lzma_stream_decoder(), lzma_alone_decoder(), or
757 * lzma_lzip_decoder() once the type of the input file has been detected.
758 *
759 * Support for .lz was added in 5.4.0.
760 *
761 * If the flag LZMA_CONCATENATED is used and the input is a .lzma file:
762 * For historical reasons concatenated .lzma files aren't supported.
763 * If there is trailing data after one .lzma stream, lzma_code() will
764 * return LZMA_DATA_ERROR. (lzma_alone_decoder() doesn't have such a check
765 * as it doesn't support any decoder flags. It will return LZMA_STREAM_END
766 * after one .lzma stream.)
767 *
768 * \param strm Pointer to lzma_stream that is at least initialized
769 * with LZMA_STREAM_INIT.
770 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX
771 * to effectively disable the limiter. liblzma
772 * 5.2.3 and earlier don't allow 0 here and return
773 * LZMA_PROG_ERROR; later versions treat 0 as if 1
774 * had been specified.
775 * \param flags Bitwise-or of zero or more of the decoder flags:
776 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
777 * LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK,
778 * LZMA_CONCATENATED, LZMA_FAIL_FAST
779 *
780 * \return Possible lzma_ret values:
781 * - LZMA_OK: Initialization was successful.
782 * - LZMA_MEM_ERROR: Cannot allocate memory.
783 * - LZMA_OPTIONS_ERROR: Unsupported flags
784 * - LZMA_PROG_ERROR
785 */
786extern LZMA_API(lzma_ret) lzma_auto_decoder(
787 lzma_stream *strm, uint64_t memlimit, uint32_t flags)
788 lzma_nothrow lzma_attr_warn_unused_result;
789
790
791/**
792 * \brief Initialize .lzma decoder (legacy file format)
793 *
794 * Valid `action' arguments to lzma_code() are LZMA_RUN and LZMA_FINISH.
795 * There is no need to use LZMA_FINISH, but it's allowed because it may
796 * simplify certain types of applications.
797 *
798 * \param strm Pointer to lzma_stream that is at least initialized
799 * with LZMA_STREAM_INIT.
800 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX
801 * to effectively disable the limiter. liblzma
802 * 5.2.3 and earlier don't allow 0 here and return
803 * LZMA_PROG_ERROR; later versions treat 0 as if 1
804 * had been specified.
805 *
806 * \return Possible lzma_ret values:
807 * - LZMA_OK
808 * - LZMA_MEM_ERROR
809 * - LZMA_PROG_ERROR
810 */
811extern LZMA_API(lzma_ret) lzma_alone_decoder(
812 lzma_stream *strm, uint64_t memlimit)
813 lzma_nothrow lzma_attr_warn_unused_result;
814
815
816/**
817 * \brief Initialize .lz (lzip) decoder (a foreign file format)
818 *
819 * This decoder supports the .lz format version 0 and the unextended .lz
820 * format version 1:
821 *
822 * - Files in the format version 0 were produced by lzip 1.3 and older.
823 * Such files aren't common but may be found from file archives
824 * as a few source packages were released in this format. People
825 * might have old personal files in this format too. Decompression
826 * support for the format version 0 was removed in lzip 1.18.
827 *
828 * - lzip 1.3 added decompression support for .lz format version 1 files.
829 * Compression support was added in lzip 1.4. In lzip 1.6 the .lz format
830 * version 1 was extended to support the Sync Flush marker. This extension
831 * is not supported by liblzma. lzma_code() will return LZMA_DATA_ERROR
832 * at the location of the Sync Flush marker. In practice files with
833 * the Sync Flush marker are very rare and thus liblzma can decompress
834 * almost all .lz files.
835 *
836 * Just like with lzma_stream_decoder() for .xz files, LZMA_CONCATENATED
837 * should be used when decompressing normal standalone .lz files.
838 *
839 * The .lz format allows putting non-.lz data at the end of a file after at
840 * least one valid .lz member. That is, one can append custom data at the end
841 * of a .lz file and the decoder is required to ignore it. In liblzma this
842 * is relevant only when LZMA_CONCATENATED is used. In that case lzma_code()
843 * will return LZMA_STREAM_END and leave lzma_stream.next_in pointing to
844 * the first byte of the non-.lz data. An exception to this is if the first
845 * 1-3 bytes of the non-.lz data are identical to the .lz magic bytes
846 * (0x4C, 0x5A, 0x49, 0x50; "LZIP" in US-ASCII). In such a case the 1-3 bytes
847 * will have been ignored by lzma_code(). If one wishes to locate the non-.lz
848 * data reliably, one must ensure that the first byte isn't 0x4C. Actually
849 * one should ensure that none of the first four bytes of trailing data are
850 * equal to the magic bytes because lzip >= 1.20 requires it by default.
851 *
852 * \param strm Pointer to lzma_stream that is at least initialized
853 * with LZMA_STREAM_INIT.
854 * \param memlimit Memory usage limit as bytes. Use UINT64_MAX
855 * to effectively disable the limiter.
856 * \param flags Bitwise-or of flags, or zero for no flags.
857 * All decoder flags listed above are supported
858 * although only LZMA_CONCATENATED and (in very rare
859 * cases) LZMA_IGNORE_CHECK are actually useful.
860 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
861 * and LZMA_FAIL_FAST do nothing. LZMA_TELL_ANY_CHECK
862 * is supported for consistency only as CRC32 is
863 * always used in the .lz format.
864 *
865 * \return Possible lzma_ret values:
866 * - LZMA_OK: Initialization was successful.
867 * - LZMA_MEM_ERROR: Cannot allocate memory.
868 * - LZMA_OPTIONS_ERROR: Unsupported flags
869 * - LZMA_PROG_ERROR
870 */
871extern LZMA_API(lzma_ret) lzma_lzip_decoder(
872 lzma_stream *strm, uint64_t memlimit, uint32_t flags)
873 lzma_nothrow lzma_attr_warn_unused_result;
874
875
876/**
877 * \brief Single-call .xz Stream decoder
878 *
879 * \param memlimit Pointer to how much memory the decoder is allowed
880 * to allocate. The value pointed by this pointer is
881 * modified if and only if LZMA_MEMLIMIT_ERROR is
882 * returned.
883 * \param flags Bitwise-or of zero or more of the decoder flags:
884 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
885 * LZMA_IGNORE_CHECK, LZMA_CONCATENATED,
886 * LZMA_FAIL_FAST. Note that LZMA_TELL_ANY_CHECK
887 * is not allowed and will return LZMA_PROG_ERROR.
888 * \param allocator lzma_allocator for custom allocator functions.
889 * Set to NULL to use malloc() and free().
890 * \param in Beginning of the input buffer
891 * \param in_pos The next byte will be read from in[*in_pos].
892 * *in_pos is updated only if decoding succeeds.
893 * \param in_size Size of the input buffer; the first byte that
894 * won't be read is in[in_size].
895 * \param[out] out Beginning of the output buffer
896 * \param[out] out_pos The next byte will be written to out[*out_pos].
897 * *out_pos is updated only if decoding succeeds.
898 * \param out_size Size of the out buffer; the first byte into
899 * which no data is written to is out[out_size].
900 *
901 * \return Possible lzma_ret values:
902 * - LZMA_OK: Decoding was successful.
903 * - LZMA_FORMAT_ERROR
904 * - LZMA_OPTIONS_ERROR
905 * - LZMA_DATA_ERROR
906 * - LZMA_NO_CHECK: This can be returned only if using
907 * the LZMA_TELL_NO_CHECK flag.
908 * - LZMA_UNSUPPORTED_CHECK: This can be returned only if using
909 * the LZMA_TELL_UNSUPPORTED_CHECK flag.
910 * - LZMA_MEM_ERROR
911 * - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached.
912 * The minimum required memlimit value was stored to *memlimit.
913 * - LZMA_BUF_ERROR: Output buffer was too small.
914 * - LZMA_PROG_ERROR
915 */
916extern LZMA_API(lzma_ret) lzma_stream_buffer_decode(
917 uint64_t *memlimit, uint32_t flags,
918 const lzma_allocator *allocator,
919 const uint8_t *in, size_t *in_pos, size_t in_size,
920 uint8_t *out, size_t *out_pos, size_t out_size)
921 lzma_nothrow lzma_attr_warn_unused_result;
922
923
924/**
925 * \brief MicroLZMA decoder
926 *
927 * See lzma_microlzma_encoder() for more information.
928 *
929 * The lzma_code() usage with this decoder is completely normal. The
930 * special behavior of lzma_code() applies to lzma_microlzma_encoder() only.
931 *
932 * \param strm Pointer to lzma_stream that is at least initialized
933 * with LZMA_STREAM_INIT.
934 * \param comp_size Compressed size of the MicroLZMA stream.
935 * The caller must somehow know this exactly.
936 * \param uncomp_size Uncompressed size of the MicroLZMA stream.
937 * If the exact uncompressed size isn't known, this
938 * can be set to a value that is at most as big as
939 * the exact uncompressed size would be, but then the
940 * next argument uncomp_size_is_exact must be false.
941 * \param uncomp_size_is_exact
942 * If true, uncomp_size must be exactly correct.
943 * This will improve error detection at the end of
944 * the stream. If the exact uncompressed size isn't
945 * known, this must be false. uncomp_size must still
946 * be at most as big as the exact uncompressed size
947 * is. Setting this to false when the exact size is
948 * known will work but error detection at the end of
949 * the stream will be weaker.
950 * \param dict_size LZMA dictionary size that was used when
951 * compressing the data. It is OK to use a bigger
952 * value too but liblzma will then allocate more
953 * memory than would actually be required and error
954 * detection will be slightly worse. (Note that with
955 * the implementation in XZ Embedded it doesn't
956 * affect the memory usage if one specifies bigger
957 * dictionary than actually required.)
958 *
959 * \return Possible lzma_ret values:
960 * - LZMA_OK
961 * - LZMA_MEM_ERROR
962 * - LZMA_OPTIONS_ERROR
963 * - LZMA_PROG_ERROR
964 */
965extern LZMA_API(lzma_ret) lzma_microlzma_decoder(
966 lzma_stream *strm, uint64_t comp_size,
967 uint64_t uncomp_size, lzma_bool uncomp_size_is_exact,
968 uint32_t dict_size) lzma_nothrow;
969

source code of include/lzma/container.h