aboutsummaryrefslogtreecommitdiff
path: root/src/liblzma/api/lzma/container.h
blob: 0fbe9778525a6b5c3ee26f638265063871c5a84e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
/**
 * \file        lzma/container.h
 * \brief       File formats
 */

/*
 * Author: Lasse Collin
 *
 * This file has been put into the public domain.
 * You can do whatever you want with this file.
 *
 * See ../lzma.h for information about liblzma as a whole.
 */

#ifndef LZMA_H_INTERNAL
#	error Never include this file directly. Use <lzma.h> instead.
#endif


/************
 * Encoding *
 ************/

/**
 * \brief       Default compression preset
 *
 * It's not straightforward to recommend a default preset, because in some
 * cases keeping the resource usage relatively low is more important that
 * getting the maximum compression ratio.
 */
#define LZMA_PRESET_DEFAULT     UINT32_C(6)


/**
 * \brief       Mask for preset level
 *
 * This is useful only if you need to extract the level from the preset
 * variable. That should be rare.
 */
#define LZMA_PRESET_LEVEL_MASK  UINT32_C(0x1F)


/*
 * Preset flags
 *
 * Currently only one flag is defined.
 */

/**
 * \brief       Extreme compression preset
 *
 * This flag modifies the preset to make the encoding significantly slower
 * while improving the compression ratio only marginally. This is useful
 * when you don't mind wasting time to get as small result as possible.
 *
 * This flag doesn't affect the memory usage requirements of the decoder (at
 * least not significantly). The memory usage of the encoder may be increased
 * a little but only at the lowest preset levels (0-3).
 */
#define LZMA_PRESET_EXTREME       (UINT32_C(1) << 31)


/**
 * \brief       Multithreading options
 */
typedef struct {
	/**
	 * \brief       Flags
	 *
	 * Set this to zero if no flags are wanted.
	 *
	 * Encoder: No flags are currently supported.
	 *
	 * Decoder: Bitwise-or of zero or more of the decoder flags:
	 * LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
	 * LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK,
	 * LZMA_CONCATENATED, LZMA_FAIL_FAST
	 */
	uint32_t flags;

	/**
	 * \brief       Number of worker threads to use
	 */
	uint32_t threads;

	/**
	 * \brief       Encoder only: Maximum uncompressed size of a Block
	 *
	 * The encoder will start a new .xz Block every block_size bytes.
	 * Using LZMA_FULL_FLUSH or LZMA_FULL_BARRIER with lzma_code()
	 * the caller may tell liblzma to start a new Block earlier.
	 *
	 * With LZMA2, a recommended block size is 2-4 times the LZMA2
	 * dictionary size. With very small dictionaries, it is recommended
	 * to use at least 1 MiB block size for good compression ratio, even
	 * if this is more than four times the dictionary size. Note that
	 * these are only recommendations for typical use cases; feel free
	 * to use other values. Just keep in mind that using a block size
	 * less than the LZMA2 dictionary size is waste of RAM.
	 *
	 * Set this to 0 to let liblzma choose the block size depending
	 * on the compression options. For LZMA2 it will be 3*dict_size
	 * or 1 MiB, whichever is more.
	 *
	 * For each thread, about 3 * block_size bytes of memory will be
	 * allocated. This may change in later liblzma versions. If so,
	 * the memory usage will probably be reduced, not increased.
	 */
	uint64_t block_size;

	/**
	 * \brief       Timeout to allow lzma_code() to return early
	 *
	 * Multithreading can make liblzma to consume input and produce
	 * output in a very bursty way: it may first read a lot of input
	 * to fill internal buffers, then no input or output occurs for
	 * a while.
	 *
	 * In single-threaded mode, lzma_code() won't return until it has
	 * either consumed all the input or filled the output buffer. If
	 * this is done in multithreaded mode, it may cause a call
	 * lzma_code() to take even tens of seconds, which isn't acceptable
	 * in all applications.
	 *
	 * To avoid very long blocking times in lzma_code(), a timeout
	 * (in milliseconds) may be set here. If lzma_code() would block
	 * longer than this number of milliseconds, it will return with
	 * LZMA_OK. Reasonable values are 100 ms or more. The xz command
	 * line tool uses 300 ms.
	 *
	 * If long blocking times are fine for you, set timeout to a special
	 * value of 0, which will disable the timeout mechanism and will make
	 * lzma_code() block until all the input is consumed or the output
	 * buffer has been filled.
	 *
	 * \note        Even with a timeout, lzma_code() might sometimes take
	 *              somewhat long time to return. No timing guarantees
	 *              are made.
	 */
	uint32_t timeout;

	/**
	 * \brief       Encoder only: Compression preset
	 *
	 * The preset is set just like with lzma_easy_encoder().
	 * The preset is ignored if filters below is non-NULL.
	 */
	uint32_t preset;

	/**
	 * \brief       Encoder only: Filter chain (alternative to a preset)
	 *
	 * If this is NULL, the preset above is used. Otherwise the preset
	 * is ignored and the filter chain specified here is used.
	 */
	const lzma_filter *filters;

	/**
	 * \brief       Encoder only: Integrity check type
	 *
	 * See check.h for available checks. The xz command line tool
	 * defaults to LZMA_CHECK_CRC64, which is a good choice if you
	 * are unsure.
	 */
	lzma_check check;

	/*
	 * Reserved space to allow possible future extensions without
	 * breaking the ABI. You should not touch these, because the names
	 * of these variables may change. These are and will never be used
	 * with the currently supported options, so it is safe to leave these
	 * uninitialized.
	 */
	lzma_reserved_enum reserved_enum1;
	lzma_reserved_enum reserved_enum2;
	lzma_reserved_enum reserved_enum3;
	uint32_t reserved_int1;
	uint32_t reserved_int2;
	uint32_t reserved_int3;
	uint32_t reserved_int4;

	/**
	 * \brief       Memory usage limit to reduce the number of threads
	 *
	 * Encoder: Ignored.
	 *
	 * Decoder:
	 *
	 * If the number of threads has been set so high that more than
	 * memlimit_threading bytes of memory would be needed, the number
	 * of threads will be reduced so that the memory usage will not exceed
	 * memlimit_threading bytes. However, if memlimit_threading cannot
	 * be met even in single-threaded mode, then decoding will continue
	 * in single-threaded mode and memlimit_threading may be exceeded
	 * even by a large amount. That is, memlimit_threading will never make
	 * lzma_code() return LZMA_MEMLIMIT_ERROR. To truly cap the memory
	 * usage, see memlimit_stop below.
	 *
	 * Setting memlimit_threading to UINT64_MAX or a similar huge value
	 * means that liblzma is allowed to keep the whole compressed file
	 * and the whole uncompressed file in memory in addition to the memory
	 * needed by the decompressor data structures used by each thread!
	 * In other words, a reasonable value limit must be set here or it
	 * will cause problems sooner or later. If you have no idea what
	 * a reasonable value could be, try lzma_physmem() / 4 as a starting
	 * point. Setting this limit will never prevent decompression of
	 * a file; this will only reduce the number of threads.
	 *
	 * If memlimit_threading is greater than memlimit_stop, then the value
	 * of memlimit_stop will be used for both.
	 */
	uint64_t memlimit_threading;

	/**
	 * \brief       Memory usage limit that should never be exceeded
	 *
	 * Encoder: Ignored.
	 *
	 * Decoder: If decompressing will need more than this amount of
	 * memory even in the single-threaded mode, then lzma_code() will
	 * return LZMA_MEMLIMIT_ERROR.
	 */
	uint64_t memlimit_stop;

	uint64_t reserved_int7;
	uint64_t reserved_int8;
	void *reserved_ptr1;
	void *reserved_ptr2;
	void *reserved_ptr3;
	void *reserved_ptr4;

} lzma_mt;


/**
 * \brief       Calculate approximate memory usage of easy encoder
 *
 * This function is a wrapper for lzma_raw_encoder_memusage().
 *
 * \param       preset  Compression preset (level and possible flags)
 *
 * \return      Number of bytes of memory required for the given
 *              preset when encoding. If an error occurs, for example
 *              due to unsupported preset, UINT64_MAX is returned.
 */
extern LZMA_API(uint64_t) lzma_easy_encoder_memusage(uint32_t preset)
		lzma_nothrow lzma_attr_pure;


/**
 * \brief       Calculate approximate decoder memory usage of a preset
 *
 * This function is a wrapper for lzma_raw_decoder_memusage().
 *
 * \param       preset  Compression preset (level and possible flags)
 *
 * \return      Number of bytes of memory required to decompress a file
 *              that was compressed using the given preset. If an error
 *              occurs, for example due to unsupported preset, UINT64_MAX
 *              is returned.
 */
extern LZMA_API(uint64_t) lzma_easy_decoder_memusage(uint32_t preset)
		lzma_nothrow lzma_attr_pure;


/**
 * \brief       Initialize .xz Stream encoder using a preset number
 *
 * This function is intended for those who just want to use the basic features
 * if liblzma (that is, most developers out there).
 *
 * \param       strm    Pointer to lzma_stream that is at least initialized
 *                      with LZMA_STREAM_INIT.
 * \param       preset  Compression preset to use. A preset consist of level
 *                      number and zero or more flags. Usually flags aren't
 *                      used, so preset is simply a number [0, 9] which match
 *                      the options -0 ... -9 of the xz command line tool.
 *                      Additional flags can be be set using bitwise-or with
 *                      the preset level number, e.g. 6 | LZMA_PRESET_EXTREME.
 * \param       check   Integrity check type to use. See check.h for available
 *                      checks. The xz command line tool defaults to
 *                      LZMA_CHECK_CRC64, which is a good choice if you are
 *                      unsure. LZMA_CHECK_CRC32 is good too as long as the
 *                      uncompressed file is not many gigabytes.
 *
 * \return      - LZMA_OK: Initialization succeeded. Use lzma_code() to
 *                encode your data.
 *              - LZMA_MEM_ERROR: Memory allocation failed.
 *              - LZMA_OPTIONS_ERROR: The given compression preset is not
 *                supported by this build of liblzma.
 *              - LZMA_UNSUPPORTED_CHECK: The given check type is not
 *                supported by this liblzma build.
 *              - LZMA_PROG_ERROR: One or more of the parameters have values
 *                that will never be valid. For example, strm == NULL.
 *
 * If initialization fails (return value is not LZMA_OK), all the memory
 * allocated for *strm by liblzma is always freed. Thus, there is no need
 * to call lzma_end() after failed initialization.
 *
 * If initialization succeeds, use lzma_code() to do the actual encoding.
 * Valid values for `action' (the second argument of lzma_code()) are
 * LZMA_RUN, LZMA_SYNC_FLUSH, LZMA_FULL_FLUSH, and LZMA_FINISH. In future,
 * there may be compression levels or flags that don't support LZMA_SYNC_FLUSH.
 */
extern LZMA_API(lzma_ret) lzma_easy_encoder(
		lzma_stream *strm, uint32_t preset, lzma_check check)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       Single-call .xz Stream encoding using a preset number
 *
 * The maximum required output buffer size can be calculated with
 * lzma_stream_buffer_bound().
 *
 * \param       preset      Compression preset to use. See the description
 *                          in lzma_easy_encoder().
 * \param       check       Type of the integrity check to calculate from
 *                          uncompressed data.
 * \param       allocator   lzma_allocator for custom allocator functions.
 *                          Set to NULL to use malloc() and free().
 * \param       in          Beginning of the input buffer
 * \param       in_size     Size of the input buffer
 * \param       out         Beginning of the output buffer
 * \param       out_pos     The next byte will be written to out[*out_pos].
 *                          *out_pos is updated only if encoding succeeds.
 * \param       out_size    Size of the out buffer; the first byte into
 *                          which no data is written to is out[out_size].
 *
 * \return      - LZMA_OK: Encoding was successful.
 *              - LZMA_BUF_ERROR: Not enough output buffer space.
 *              - LZMA_UNSUPPORTED_CHECK
 *              - LZMA_OPTIONS_ERROR
 *              - LZMA_MEM_ERROR
 *              - LZMA_DATA_ERROR
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_easy_buffer_encode(
		uint32_t preset, lzma_check check,
		const lzma_allocator *allocator,
		const uint8_t *in, size_t in_size,
		uint8_t *out, size_t *out_pos, size_t out_size) lzma_nothrow;


/**
 * \brief       Initialize .xz Stream encoder using a custom filter chain
 *
 * \param       strm    Pointer to properly prepared lzma_stream
 * \param       filters Array of filters. This must be terminated with
 *                      filters[n].id = LZMA_VLI_UNKNOWN. See filter.h for
 *                      more information.
 * \param       check   Type of the integrity check to calculate from
 *                      uncompressed data.
 *
 * \return      - LZMA_OK: Initialization was successful.
 *              - LZMA_MEM_ERROR
 *              - LZMA_UNSUPPORTED_CHECK
 *              - LZMA_OPTIONS_ERROR
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_stream_encoder(lzma_stream *strm,
		const lzma_filter *filters, lzma_check check)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       Calculate approximate memory usage of multithreaded .xz encoder
 *
 * Since doing the encoding in threaded mode doesn't affect the memory
 * requirements of single-threaded decompressor, you can use
 * lzma_easy_decoder_memusage(options->preset) or
 * lzma_raw_decoder_memusage(options->filters) to calculate
 * the decompressor memory requirements.
 *
 * \param       options Compression options
 *
 * \return      Number of bytes of memory required for encoding with the
 *              given options. If an error occurs, for example due to
 *              unsupported preset or filter chain, UINT64_MAX is returned.
 */
extern LZMA_API(uint64_t) lzma_stream_encoder_mt_memusage(
		const lzma_mt *options) lzma_nothrow lzma_attr_pure;


/**
 * \brief       Initialize multithreaded .xz Stream encoder
 *
 * This provides the functionality of lzma_easy_encoder() and
 * lzma_stream_encoder() as a single function for multithreaded use.
 *
 * The supported actions for lzma_code() are LZMA_RUN, LZMA_FULL_FLUSH,
 * LZMA_FULL_BARRIER, and LZMA_FINISH. Support for LZMA_SYNC_FLUSH might be
 * added in the future.
 *
 * \param       strm    Pointer to properly prepared lzma_stream
 * \param       options Pointer to multithreaded compression options
 *
 * \return      - LZMA_OK
 *              - LZMA_MEM_ERROR
 *              - LZMA_UNSUPPORTED_CHECK
 *              - LZMA_OPTIONS_ERROR
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_stream_encoder_mt(
		lzma_stream *strm, const lzma_mt *options)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       Initialize .lzma encoder (legacy file format)
 *
 * The .lzma format is sometimes called the LZMA_Alone format, which is the
 * reason for the name of this function. The .lzma format supports only the
 * LZMA1 filter. There is no support for integrity checks like CRC32.
 *
 * Use this function if and only if you need to create files readable by
 * legacy LZMA tools such as LZMA Utils 4.32.x. Moving to the .xz format
 * is strongly recommended.
 *
 * The valid action values for lzma_code() are LZMA_RUN and LZMA_FINISH.
 * No kind of flushing is supported, because the file format doesn't make
 * it possible.
 *
 * \return      - LZMA_OK
 *              - LZMA_MEM_ERROR
 *              - LZMA_OPTIONS_ERROR
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_alone_encoder(
		lzma_stream *strm, const lzma_options_lzma *options)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       Calculate output buffer size for single-call Stream encoder
 *
 * When trying to compress uncompressible data, the encoded size will be
 * slightly bigger than the input data. This function calculates how much
 * output buffer space is required to be sure that lzma_stream_buffer_encode()
 * doesn't return LZMA_BUF_ERROR.
 *
 * The calculated value is not exact, but it is guaranteed to be big enough.
 * The actual maximum output space required may be slightly smaller (up to
 * about 100 bytes). This should not be a problem in practice.
 *
 * If the calculated maximum size doesn't fit into size_t or would make the
 * Stream grow past LZMA_VLI_MAX (which should never happen in practice),
 * zero is returned to indicate the error.
 *
 * \note        The limit calculated by this function applies only to
 *              single-call encoding. Multi-call encoding may (and probably
 *              will) have larger maximum expansion when encoding
 *              uncompressible data. Currently there is no function to
 *              calculate the maximum expansion of multi-call encoding.
 */
extern LZMA_API(size_t) lzma_stream_buffer_bound(size_t uncompressed_size)
		lzma_nothrow;


/**
 * \brief       Single-call .xz Stream encoder
 *
 * \param       filters     Array of filters. This must be terminated with
 *                          filters[n].id = LZMA_VLI_UNKNOWN. See filter.h
 *                          for more information.
 * \param       check       Type of the integrity check to calculate from
 *                          uncompressed data.
 * \param       allocator   lzma_allocator for custom allocator functions.
 *                          Set to NULL to use malloc() and free().
 * \param       in          Beginning of the input buffer
 * \param       in_size     Size of the input buffer
 * \param       out         Beginning of the output buffer
 * \param       out_pos     The next byte will be written to out[*out_pos].
 *                          *out_pos is updated only if encoding succeeds.
 * \param       out_size    Size of the out buffer; the first byte into
 *                          which no data is written to is out[out_size].
 *
 * \return      - LZMA_OK: Encoding was successful.
 *              - LZMA_BUF_ERROR: Not enough output buffer space.
 *              - LZMA_UNSUPPORTED_CHECK
 *              - LZMA_OPTIONS_ERROR
 *              - LZMA_MEM_ERROR
 *              - LZMA_DATA_ERROR
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_stream_buffer_encode(
		lzma_filter *filters, lzma_check check,
		const lzma_allocator *allocator,
		const uint8_t *in, size_t in_size,
		uint8_t *out, size_t *out_pos, size_t out_size)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       MicroLZMA encoder
 *
 * The MicroLZMA format is a raw LZMA stream whose first byte (always 0x00)
 * has been replaced with bitwise-negation of the LZMA properties (lc/lp/pb).
 * This encoding ensures that the first byte of MicroLZMA stream is never
 * 0x00. There is no end of payload marker and thus the uncompressed size
 * must be stored separately. For the best error detection the dictionary
 * size should be stored separately as well but alternatively one may use
 * the uncompressed size as the dictionary size when decoding.
 *
 * With the MicroLZMA encoder, lzma_code() behaves slightly unusually.
 * The action argument must be LZMA_FINISH and the return value will never be
 * LZMA_OK. Thus the encoding is always done with a single lzma_code() after
 * the initialization. The benefit of the combination of initialization
 * function and lzma_code() is that memory allocations can be re-used for
 * better performance.
 *
 * lzma_code() will try to encode as much input as is possible to fit into
 * the given output buffer. If not all input can be encoded, the stream will
 * be finished without encoding all the input. The caller must check both
 * input and output buffer usage after lzma_code() (total_in and total_out
 * in lzma_stream can be convenient). Often lzma_code() can fill the output
 * buffer completely if there is a lot of input, but sometimes a few bytes
 * may remain unused because the next LZMA symbol would require more space.
 *
 * lzma_stream.avail_out must be at least 6. Otherwise LZMA_PROG_ERROR
 * will be returned.
 *
 * The LZMA dictionary should be reasonably low to speed up the encoder
 * re-initialization. A good value is bigger than the resulting
 * uncompressed size of most of the output chunks. For example, if output
 * size is 4 KiB, dictionary size of 32 KiB or 64 KiB is good. If the
 * data compresses extremely well, even 128 KiB may be useful.
 *
 * The MicroLZMA format and this encoder variant were made with the EROFS
 * file system in mind. This format may be convenient in other embedded
 * uses too where many small streams are needed. XZ Embedded includes a
 * decoder for this format.
 *
 * \return      - LZMA_STREAM_END: All good. Check the amounts of input used
 *                and output produced. Store the amount of input used
 *                (uncompressed size) as it needs to be known to decompress
 *                the data.
 *              - LZMA_OPTIONS_ERROR
 *              - LZMA_MEM_ERROR
 *              - LZMA_PROG_ERROR: In addition to the generic reasons for this
 *                error code, this may also be returned if there isn't enough
 *                output space (6 bytes) to create a valid MicroLZMA stream.
 */
extern LZMA_API(lzma_ret) lzma_microlzma_encoder(
		lzma_stream *strm, const lzma_options_lzma *options);


/************
 * Decoding *
 ************/

/**
 * This flag makes lzma_code() return LZMA_NO_CHECK if the input stream
 * being decoded has no integrity check. Note that when used with
 * lzma_auto_decoder(), all .lzma files will trigger LZMA_NO_CHECK
 * if LZMA_TELL_NO_CHECK is used.
 */
#define LZMA_TELL_NO_CHECK              UINT32_C(0x01)


/**
 * This flag makes lzma_code() return LZMA_UNSUPPORTED_CHECK if the input
 * stream has an integrity check, but the type of the integrity check is not
 * supported by this liblzma version or build. Such files can still be
 * decoded, but the integrity check cannot be verified.
 */
#define LZMA_TELL_UNSUPPORTED_CHECK     UINT32_C(0x02)


/**
 * This flag makes lzma_code() return LZMA_GET_CHECK as soon as the type
 * of the integrity check is known. The type can then be got with
 * lzma_get_check().
 */
#define LZMA_TELL_ANY_CHECK             UINT32_C(0x04)


/**
 * This flag makes lzma_code() not calculate and verify the integrity check
 * of the compressed data in .xz files. This means that invalid integrity
 * check values won't be detected and LZMA_DATA_ERROR won't be returned in
 * such cases.
 *
 * This flag only affects the checks of the compressed data itself; the CRC32
 * values in the .xz headers will still be verified normally.
 *
 * Don't use this flag unless you know what you are doing. Possible reasons
 * to use this flag:
 *
 *   - Trying to recover data from a corrupt .xz file.
 *
 *   - Speeding up decompression, which matters mostly with SHA-256
 *     or with files that have compressed extremely well. It's recommended
 *     to not use this flag for this purpose unless the file integrity is
 *     verified externally in some other way.
 *
 * Support for this flag was added in liblzma 5.1.4beta.
 */
#define LZMA_IGNORE_CHECK               UINT32_C(0x10)


/**
 * This flag enables decoding of concatenated files with file formats that
 * allow concatenating compressed files as is. From the formats currently
 * supported by liblzma, only the .xz format allows concatenated files.
 * Concatenated files are not allowed with the legacy .lzma format.
 *
 * This flag also affects the usage of the `action' argument for lzma_code().
 * When LZMA_CONCATENATED is used, lzma_code() won't return LZMA_STREAM_END
 * unless LZMA_FINISH is used as `action'. Thus, the application has to set
 * LZMA_FINISH in the same way as it does when encoding.
 *
 * If LZMA_CONCATENATED is not used, the decoders still accept LZMA_FINISH
 * as `action' for lzma_code(), but the usage of LZMA_FINISH isn't required.
 */
#define LZMA_CONCATENATED               UINT32_C(0x08)


/**
 * This flag makes the threaded decoder report errors (like LZMA_DATA_ERROR)
 * as soon as they are detected. This saves time when the application has no
 * interest in a partially decompressed truncated or corrupt file. Note that
 * due to timing randomness, if the same truncated or corrupt input is
 * decompressed multiple times with this flag, a different amount of output
 * may be produced by different runs, and even the error code might vary.
 *
 * When using LZMA_FAIL_FAST, it is recommended to use LZMA_FINISH to tell
 * the decoder when no more input will be coming because it can help fast
 * detection and reporting of truncated files. Note that in this situation
 * truncated files might be diagnosed with LZMA_DATA_ERROR instead of
 * LZMA_OK or LZMA_BUF_ERROR!
 *
 * Without this flag the threaded decoder will provide as much output as
 * possible at first and then report the pending error. This default behavior
 * matches the single-threaded decoder and provides repeatable behavior
 * with truncated or corrupt input. There are a few special cases where the
 * behavior can still differ like memory allocation failures (LZMA_MEM_ERROR).
 *
 * Single-threaded decoders currently ignore this flag.
 *
 * Support for this flag was added in liblzma 5.3.3alpha. Note that in older
 * versions this flag isn't supported (LZMA_OPTIONS_ERROR) even by functions
 * that ignore this flag in newer liblzma versions.
 */
#define LZMA_FAIL_FAST                  UINT32_C(0x20)


/**
 * \brief       Initialize .xz Stream decoder
 *
 * \param       strm        Pointer to properly prepared lzma_stream
 * \param       memlimit    Memory usage limit as bytes. Use UINT64_MAX
 *                          to effectively disable the limiter. liblzma
 *                          5.2.3 and earlier don't allow 0 here and return
 *                          LZMA_PROG_ERROR; later versions treat 0 as if 1
 *                          had been specified.
 * \param       flags       Bitwise-or of zero or more of the decoder flags:
 *                          LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
 *                          LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK,
 *                          LZMA_CONCATENATED, LZMA_FAIL_FAST
 *
 * \return      - LZMA_OK: Initialization was successful.
 *              - LZMA_MEM_ERROR: Cannot allocate memory.
 *              - LZMA_OPTIONS_ERROR: Unsupported flags
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_stream_decoder(
		lzma_stream *strm, uint64_t memlimit, uint32_t flags)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       Initialize multithreaded .xz Stream decoder
 *
 * \param       strm        Pointer to properly prepared lzma_stream
 * \param       options     Pointer to multithreaded compression options
 *
 * The decoder can decode multiple Blocks in parallel. This requires that each
 * Block Header contains the Compressed Size and Uncompressed size fields
 * which are added by the multi-threaded encoder, see lzma_stream_encoder_mt().
 *
 * A Stream with one Block will only utilize one thread. A Stream with multiple
 * Blocks but without size information in Block Headers will be processed in
 * single-threaded mode in the same way as done by lzma_stream_decoder().
 * Concatenated Streams are processed one Stream at a time; no inter-Stream
 * parallelization is done.
 *
 * This function behaves like lzma_stream_decoder() when options->threads == 1
 * and options->memlimit_threading <= 1.
 *
 * \return      - LZMA_OK: Initialization was successful.
 *              - LZMA_MEM_ERROR: Cannot allocate memory.
 *              - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached.
 *              - LZMA_OPTIONS_ERROR: Unsupported flags.
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_stream_decoder_mt(
		lzma_stream *strm, const lzma_mt *options)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       Decode .xz Streams and .lzma files with autodetection
 *
 * This decoder autodetects between the .xz and .lzma file formats, and
 * calls lzma_stream_decoder() or lzma_alone_decoder() once the type
 * of the input file has been detected.
 *
 * If the flag LZMA_CONCATENATED is used and the input is a .lzma file:
 * For historical reasons concatenated .lzma files aren't supported.
 * If there is trailing data after one .lzma stream, lzma_code() will
 * return LZMA_DATA_ERROR. (lzma_alone_decoder() doesn't have such a check
 * as it doesn't support any decoder flags. It will return LZMA_STREAM_END
 * after one .lzma stream.)
 *
 * \param       strm        Pointer to properly prepared lzma_stream
 * \param       memlimit    Memory usage limit as bytes. Use UINT64_MAX
 *                          to effectively disable the limiter. liblzma
 *                          5.2.3 and earlier don't allow 0 here and return
 *                          LZMA_PROG_ERROR; later versions treat 0 as if 1
 *                          had been specified.
 * \param       flags       Bitwise-or of zero or more of the decoder flags:
 *                          LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
 *                          LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK,
 *                          LZMA_CONCATENATED, LZMA_FAIL_FAST
 *
 * \return      - LZMA_OK: Initialization was successful.
 *              - LZMA_MEM_ERROR: Cannot allocate memory.
 *              - LZMA_OPTIONS_ERROR: Unsupported flags
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_auto_decoder(
		lzma_stream *strm, uint64_t memlimit, uint32_t flags)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       Initialize .lzma decoder (legacy file format)
 *
 * \param       strm        Pointer to properly prepared lzma_stream
 * \param       memlimit    Memory usage limit as bytes. Use UINT64_MAX
 *                          to effectively disable the limiter. liblzma
 *                          5.2.3 and earlier don't allow 0 here and return
 *                          LZMA_PROG_ERROR; later versions treat 0 as if 1
 *                          had been specified.
 *
 * Valid `action' arguments to lzma_code() are LZMA_RUN and LZMA_FINISH.
 * There is no need to use LZMA_FINISH, but it's allowed because it may
 * simplify certain types of applications.
 *
 * \return      - LZMA_OK
 *              - LZMA_MEM_ERROR
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_alone_decoder(
		lzma_stream *strm, uint64_t memlimit)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       Single-call .xz Stream decoder
 *
 * \param       memlimit    Pointer to how much memory the decoder is allowed
 *                          to allocate. The value pointed by this pointer is
 *                          modified if and only if LZMA_MEMLIMIT_ERROR is
 *                          returned.
 * \param       flags       Bitwise-or of zero or more of the decoder flags:
 *                          LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
 *                          LZMA_IGNORE_CHECK, LZMA_CONCATENATED,
 *                          LZMA_FAIL_FAST. Note that LZMA_TELL_ANY_CHECK
 *                          is not allowed and will return LZMA_PROG_ERROR.
 * \param       allocator   lzma_allocator for custom allocator functions.
 *                          Set to NULL to use malloc() and free().
 * \param       in          Beginning of the input buffer
 * \param       in_pos      The next byte will be read from in[*in_pos].
 *                          *in_pos is updated only if decoding succeeds.
 * \param       in_size     Size of the input buffer; the first byte that
 *                          won't be read is in[in_size].
 * \param       out         Beginning of the output buffer
 * \param       out_pos     The next byte will be written to out[*out_pos].
 *                          *out_pos is updated only if decoding succeeds.
 * \param       out_size    Size of the out buffer; the first byte into
 *                          which no data is written to is out[out_size].
 *
 * \return      - LZMA_OK: Decoding was successful.
 *              - LZMA_FORMAT_ERROR
 *              - LZMA_OPTIONS_ERROR
 *              - LZMA_DATA_ERROR
 *              - LZMA_NO_CHECK: This can be returned only if using
 *                the LZMA_TELL_NO_CHECK flag.
 *              - LZMA_UNSUPPORTED_CHECK: This can be returned only if using
 *                the LZMA_TELL_UNSUPPORTED_CHECK flag.
 *              - LZMA_MEM_ERROR
 *              - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached.
 *                The minimum required memlimit value was stored to *memlimit.
 *              - LZMA_BUF_ERROR: Output buffer was too small.
 *              - LZMA_PROG_ERROR
 */
extern LZMA_API(lzma_ret) lzma_stream_buffer_decode(
		uint64_t *memlimit, uint32_t flags,
		const lzma_allocator *allocator,
		const uint8_t *in, size_t *in_pos, size_t in_size,
		uint8_t *out, size_t *out_pos, size_t out_size)
		lzma_nothrow lzma_attr_warn_unused_result;


/**
 * \brief       MicroLZMA decoder
 *
 * See lzma_microlzma_decoder() for more information.
 *
 * The lzma_code() usage with this decoder is completely normal. The
 * special behavior of lzma_code() applies to lzma_microlzma_encoder() only.
 *
 * \param       strm        Pointer to properly prepared lzma_stream
 * \param       comp_size   Compressed size of the MicroLZMA stream.
 *                          The caller must somehow know this exactly.
 * \param       uncomp_size Uncompressed size of the MicroLZMA stream.
 *                          If the exact uncompressed size isn't known, this
 *                          can be set to a value that is at most as big as
 *                          the exact uncompressed size would be, but then the
 *                          next argument uncomp_size_is_exact must be false.
 * \param       uncomp_size_is_exact
 *                          If true, uncomp_size must be exactly correct.
 *                          This will improve error detection at the end of
 *                          the stream. If the exact uncompressed size isn't
 *                          known, this must be false. uncomp_size must still
 *                          be at most as big as the exact uncompressed size
 *                          is. Setting this to false when the exact size is
 *                          known will work but error detection at the end of
 *                          the stream will be weaker.
 * \param       dict_size   LZMA dictionary size that was used when
 *                          compressing the data. It is OK to use a bigger
 *                          value too but liblzma will then allocate more
 *                          memory than would actually be required and error
 *                          detection will be slightly worse. (Note that with
 *                          the implementation in XZ Embedded it doesn't
 *                          affect the memory usage if one specifies bigger
 *                          dictionary than actually required.)
 */
extern LZMA_API(lzma_ret) lzma_microlzma_decoder(
		lzma_stream *strm, uint64_t comp_size,
		uint64_t uncomp_size, lzma_bool uncomp_size_is_exact,
		uint32_t dict_size);