3 * \brief .xz Block handling
5 * \author Copyright (C) 1999-2006 Igor Pavlov
6 * \author Copyright (C) 2007 Lasse Collin
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
19 #ifndef LZMA_H_INTERNAL
20 # error Never include this file directly. Use <lzma.h> instead.
25 * \brief Options for the Block and Block Header encoders and decoders
27 * Different Block handling functions use different parts of this structure.
28 * Some read some members, other functions write, and some do both. Only the
29 * members listed for reading need to be initialized when the specified
30 * functions are called. The members marked for writing will be assigned
31 * new values at some point either by calling the given function or by
32 * later calls to lzma_code().
36 * \brief Block format version
38 * To prevent API and ABI breakages if new features are needed in
39 * Block, a version number is used to indicate which fields in this
40 * structure are in use. For now, version must always be zero.
41 * With non-zero version, most Block related functions will return
44 * The decoding functions will always set this to the lowest value
45 * that supports all the features indicated by the Block Header field.
46 * The application must check that the version number set by the
47 * decoding functions is supported by the application. Otherwise it
48 * is possible that the application will decode the Block incorrectly.
51 * - lzma_block_header_size()
52 * - lzma_block_header_encode()
53 * - lzma_block_compressed_size()
54 * - lzma_block_unpadded_size()
55 * - lzma_block_total_size()
56 * - lzma_block_encoder()
57 * - lzma_block_decoder()
58 * - lzma_block_buffer_encode()
59 * - lzma_block_buffer_decode()
62 * - lzma_block_header_decode()
67 * \brief Size of the Block Header field
69 * This is always a multiple of four.
72 * - lzma_block_header_encode()
73 * - lzma_block_header_decode()
74 * - lzma_block_compressed_size()
75 * - lzma_block_unpadded_size()
76 * - lzma_block_total_size()
77 * - lzma_block_decoder()
78 * - lzma_block_buffer_decode()
81 * - lzma_block_header_size()
82 * - lzma_block_buffer_encode()
85 # define LZMA_BLOCK_HEADER_SIZE_MIN 8
86 # define LZMA_BLOCK_HEADER_SIZE_MAX 1024
89 * \brief Type of integrity Check
91 * The Check ID is not stored into the Block Header, thus its value
92 * must be provided also when decoding.
95 * - lzma_block_header_encode()
96 * - lzma_block_header_decode()
97 * - lzma_block_compressed_size()
98 * - lzma_block_unpadded_size()
99 * - lzma_block_total_size()
100 * - lzma_block_encoder()
101 * - lzma_block_decoder()
102 * - lzma_block_buffer_encode()
103 * - lzma_block_buffer_decode()
108 * \brief Size of the Compressed Data in bytes
110 * Encoding: If this is not LZMA_VLI_UNKNOWN, Block Header encoder
111 * will store this value to the Block Header. Block encoder doesn't
112 * care about this value, but will set it once the encoding has been
115 * Decoding: If this is not LZMA_VLI_UNKNOWN, Block decoder will
116 * verify that the size of the Compressed Data field matches
119 * Usually you don't know this value when encoding in streamed mode,
120 * and thus cannot write this field into the Block Header.
122 * In non-streamed mode you can reserve space for this field before
123 * encoding the actual Block. After encoding the data, finish the
124 * Block by encoding the Block Header. Steps in detail:
126 * - Set compressed_size to some big enough value. If you don't know
127 * better, use LZMA_VLI_MAX, but remember that bigger values take
128 * more space in Block Header.
130 * - Call lzma_block_header_size() to see how much space you need to
131 * reserve for the Block Header.
133 * - Encode the Block using lzma_block_encoder() and lzma_code().
134 * It sets compressed_size to the correct value.
136 * - Use lzma_block_header_encode() to encode the Block Header.
137 * Because space was reserved in the first step, you don't need
138 * to call lzma_block_header_size() anymore, because due to
139 * reserving, header_size has to be big enough. If it is "too big",
140 * lzma_block_header_encode() will add enough Header Padding to
141 * make Block Header to match the size specified by header_size.
144 * - lzma_block_header_size()
145 * - lzma_block_header_encode()
146 * - lzma_block_compressed_size()
147 * - lzma_block_unpadded_size()
148 * - lzma_block_total_size()
149 * - lzma_block_decoder()
150 * - lzma_block_buffer_decode()
153 * - lzma_block_header_decode()
154 * - lzma_block_compressed_size()
155 * - lzma_block_encoder()
156 * - lzma_block_decoder()
157 * - lzma_block_buffer_encode()
158 * - lzma_block_buffer_decode()
160 lzma_vli compressed_size;
163 * \brief Uncompressed Size in bytes
165 * This is handled very similarly to compressed_size above.
167 * Unlike compressed_size, uncompressed_size is needed by fewer
168 * functions. This is because uncompressed_size isn't needed to
169 * validate that Block stays within proper limits.
172 * - lzma_block_header_size()
173 * - lzma_block_header_encode()
174 * - lzma_block_decoder()
175 * - lzma_block_buffer_decode()
178 * - lzma_block_header_decode()
179 * - lzma_block_encoder()
180 * - lzma_block_decoder()
181 * - lzma_block_buffer_encode()
182 * - lzma_block_buffer_decode()
184 lzma_vli uncompressed_size;
187 * \brief Array of filters
189 * There can be 1-4 filters. The end of the array is marked with
190 * .id = LZMA_VLI_UNKNOWN.
193 * - lzma_block_header_size()
194 * - lzma_block_header_encode()
195 * - lzma_block_encoder()
196 * - lzma_block_decoder()
197 * - lzma_block_buffer_encode()
198 * - lzma_block_buffer_decode()
201 * - lzma_block_header_decode(): Note that this does NOT free()
202 * the old filter options structures. All unused filters[] will
203 * have .id == LZMA_VLI_UNKNOWN and .options == NULL. If
204 * decoding fails, all filters[] are guaranteed to be
205 * LZMA_VLI_UNKNOWN and NULL.
207 * \note Because of the array is terminated with
208 * .id = LZMA_VLI_UNKNOWN, the actual array must
209 * have LZMA_FILTERS_MAX + 1 members or the Block
210 * Header decoder will overflow the buffer.
212 lzma_filter *filters;
215 * Reserved space to allow possible future extensions without
216 * breaking the ABI. You should not touch these, because the names
217 * of these variables may change. These are and will never be used
218 * with the currently supported options, so it is safe to leave these
224 uint32_t reserved_int1;
225 uint32_t reserved_int2;
226 lzma_vli reserved_int3;
227 lzma_vli reserved_int4;
228 lzma_vli reserved_int5;
229 lzma_vli reserved_int6;
230 lzma_vli reserved_int7;
231 lzma_vli reserved_int8;
232 lzma_reserved_enum reserved_enum1;
233 lzma_reserved_enum reserved_enum2;
234 lzma_reserved_enum reserved_enum3;
235 lzma_reserved_enum reserved_enum4;
236 lzma_bool reserved_bool1;
237 lzma_bool reserved_bool2;
238 lzma_bool reserved_bool3;
239 lzma_bool reserved_bool4;
240 lzma_bool reserved_bool5;
241 lzma_bool reserved_bool6;
242 lzma_bool reserved_bool7;
243 lzma_bool reserved_bool8;
249 * \brief Decode the Block Header Size field
251 * To decode Block Header using lzma_block_header_decode(), the size of the
252 * Block Header has to be known and stored into lzma_block.header_size.
253 * The size can be calculated from the first byte of a Block using this macro.
254 * Note that if the first byte is 0x00, it indicates beginning of Index; use
255 * this macro only when the byte is not 0x00.
257 * There is no encoding macro, because Block Header encoder is enough for that.
259 #define lzma_block_header_size_decode(b) (((uint32_t)(b) + 1) * 4)
263 * \brief Calculate Block Header Size
265 * Calculate the minimum size needed for the Block Header field using the
266 * settings specified in the lzma_block structure. Note that it is OK to
267 * increase the calculated header_size value as long as it is a multiple of
268 * four and doesn't exceed LZMA_BLOCK_HEADER_SIZE_MAX. Increasing header_size
269 * just means that lzma_block_header_encode() will add Header Padding.
271 * \return - LZMA_OK: Size calculated successfully and stored to
272 * block->header_size.
273 * - LZMA_OPTIONS_ERROR: Unsupported version, filters or
275 * - LZMA_PROG_ERROR: Invalid values like compressed_size == 0.
277 * \note This doesn't check that all the options are valid i.e. this
278 * may return LZMA_OK even if lzma_block_header_encode() or
279 * lzma_block_encoder() would fail. If you want to validate the
280 * filter chain, consider using lzma_memlimit_encoder() which as
281 * a side-effect validates the filter chain.
283 extern LZMA_API(lzma_ret) lzma_block_header_size(lzma_block *block)
284 lzma_attr_warn_unused_result;
288 * \brief Encode Block Header
290 * The caller must have calculated the size of the Block Header already with
291 * lzma_block_header_size(). If larger value than the one calculated by
292 * lzma_block_header_size() is used, the Block Header will be padded to the
295 * \param out Beginning of the output buffer. This must be
296 * at least block->header_size bytes.
297 * \param block Block options to be encoded.
299 * \return - LZMA_OK: Encoding was successful. block->header_size
300 * bytes were written to output buffer.
301 * - LZMA_OPTIONS_ERROR: Invalid or unsupported options.
302 * - LZMA_PROG_ERROR: Invalid arguments, for example
303 * block->header_size is invalid or block->filters is NULL.
305 extern LZMA_API(lzma_ret) lzma_block_header_encode(
306 const lzma_block *block, uint8_t *out)
307 lzma_attr_warn_unused_result;
311 * \brief Decode Block Header
313 * The size of the Block Header must have already been decoded with
314 * lzma_block_header_size_decode() macro and stored to block->header_size.
315 * block->filters must have been allocated, but not necessarily initialized.
316 * Possible existing filter options are _not_ freed.
318 * \param block Destination for block options with header_size
319 * properly initialized.
320 * \param allocator lzma_allocator for custom allocator functions.
321 * Set to NULL to use malloc() (and also free()
322 * if an error occurs).
323 * \param in Beginning of the input buffer. This must be
324 * at least block->header_size bytes.
326 * \return - LZMA_OK: Decoding was successful. block->header_size
327 * bytes were read from the input buffer.
328 * - LZMA_OPTIONS_ERROR: The Block Header specifies some
329 * unsupported options such as unsupported filters.
330 * - LZMA_DATA_ERROR: Block Header is corrupt, for example,
331 * the CRC32 doesn't match.
332 * - LZMA_PROG_ERROR: Invalid arguments, for example
333 * block->header_size is invalid or block->filters is NULL.
335 extern LZMA_API(lzma_ret) lzma_block_header_decode(lzma_block *block,
336 lzma_allocator *allocator, const uint8_t *in)
337 lzma_attr_warn_unused_result;
341 * \brief Validate and set Compressed Size according to Unpadded Size
343 * Block Header stores Compressed Size, but Index has Unpadded Size. If the
344 * application has already parsed the Index and is now decoding Blocks,
345 * it can calculate Compressed Size from Unpadded Size. This function does
346 * exactly that with error checking:
348 * - Compressed Size calculated from Unpadded Size must be positive integer,
349 * that is, Unpadded Size must be big enough that after Block Header and
350 * Check fields there's still at least one byte for Compressed Size.
352 * - If Compressed Size was present in Block Header, the new value
353 * calculated from Unpadded Size is compared against the value
356 * \note This function must be called _after_ decoding the Block Header
357 * field so that it can properly validate Compressed Size if it
358 * was present in Block Header.
360 * \return - LZMA_OK: block->compressed_size was set successfully.
361 * - LZMA_DATA_ERROR: unpadded_size is too small compared to
362 * block->header_size and lzma_check_size(block->check).
363 * - LZMA_PROG_ERROR: Some values are invalid. For example,
364 * block->header_size must be a multiple of four and
365 * between 8 and 1024 inclusive.
367 extern LZMA_API(lzma_ret) lzma_block_compressed_size(
368 lzma_block *block, lzma_vli unpadded_size)
369 lzma_attr_warn_unused_result;
373 * \brief Calculate Unpadded Size
375 * The Index field stores Unpadded Size and Uncompressed Size. The latter
376 * can be taken directly from the lzma_block structure after coding a Block,
377 * but Unpadded Size needs to be calculated from Block Header Size,
378 * Compressed Size, and size of the Check field. This is where this function
381 * \return Unpadded Size on success, or zero on error.
383 extern LZMA_API(lzma_vli) lzma_block_unpadded_size(const lzma_block *block)
388 * \brief Calculate the total encoded size of a Block
390 * This is equivalent to lzma_block_unpadded_size() except that the returned
391 * value includes the size of the Block Padding field.
393 * \return On success, total encoded size of the Block. On error,
396 extern LZMA_API(lzma_vli) lzma_block_total_size(const lzma_block *block)
401 * \brief Initialize .xz Block encoder
403 * Valid actions for lzma_code() are LZMA_RUN, LZMA_SYNC_FLUSH (only if the
404 * filter chain supports it), and LZMA_FINISH.
406 * \return - LZMA_OK: All good, continue with lzma_code().
408 * - LZMA_OPTIONS_ERROR
409 * - LZMA_UNSUPPORTED_CHECK: block->check specfies a Check ID
410 * that is not supported by this buid of liblzma. Initializing
411 * the encoder failed.
414 extern LZMA_API(lzma_ret) lzma_block_encoder(
415 lzma_stream *strm, lzma_block *block)
416 lzma_attr_warn_unused_result;
420 * \brief Initialize .xz Block decoder
422 * Valid actions for lzma_code() are LZMA_RUN and LZMA_FINISH. Using
423 * LZMA_FINISH is not required. It is supported only for convenience.
425 * \return - LZMA_OK: All good, continue with lzma_code().
426 * - LZMA_UNSUPPORTED_CHECK: Initialization was successful, but
427 * the given Check ID is not supported, thus Check will be
432 extern LZMA_API(lzma_ret) lzma_block_decoder(
433 lzma_stream *strm, lzma_block *block)
434 lzma_attr_warn_unused_result;
438 * \brief Calculate maximum output buffer size for single-call encoding
440 * This is equivalent to lzma_stream_buffer_bound() but for .xz Blocks.
441 * See the documentation of lzma_stream_buffer_bound().
443 extern LZMA_API(size_t) lzma_block_buffer_bound(size_t uncompressed_size);
447 * \brief Single-call .xz Block encoder
449 * In contrast to the multi-call encoder initialized with
450 * lzma_block_encoder(), this function encodes also the Block Header. This
451 * is required to make it possible to write appropriate Block Header also
452 * in case the data isn't compressible, and different filter chain has to be
453 * used to encode the data in uncompressed form using uncompressed chunks
454 * of the LZMA2 filter.
456 * When the data isn't compressible, header_size, compressed_size, and
457 * uncompressed_size are set just like when the data was compressible, but
458 * it is possible that header_size is too small to hold the filter chain
459 * specified in block->filters, because that isn't necessarily the filter
460 * chain that was actually used to encode the data. lzma_block_unpadded_size()
461 * still works normally, because it doesn't read the filters array.
463 * \param block Block options: block->version, block->check,
464 * and block->filters must be initialized.
465 * \param allocator lzma_allocator for custom allocator functions.
466 * Set to NULL to use malloc() and free().
467 * \param in Beginning of the input buffer
468 * \param in_size Size of the input buffer
469 * \param out Beginning of the output buffer
470 * \param out_pos The next byte will be written to out[*out_pos].
471 * *out_pos is updated only if encoding succeeds.
472 * \param out_size Size of the out buffer; the first byte into
473 * which no data is written to is out[out_size].
475 * \return - LZMA_OK: Encoding was successful.
476 * - LZMA_BUF_ERROR: Not enough output buffer space.
477 * - LZMA_OPTIONS_ERROR
482 extern LZMA_API(lzma_ret) lzma_block_buffer_encode(
483 lzma_block *block, lzma_allocator *allocator,
484 const uint8_t *in, size_t in_size,
485 uint8_t *out, size_t *out_pos, size_t out_size)
486 lzma_attr_warn_unused_result;
490 * \brief Single-call .xz Block decoder
492 * This is single-call equivalent of lzma_block_decoder(), and requires that
493 * the caller has already decoded Block Header and checked its memory usage.
495 * \param block Block options just like with lzma_block_decoder().
496 * \param allocator lzma_allocator for custom allocator functions.
497 * Set to NULL to use malloc() and free().
498 * \param in Beginning of the input buffer
499 * \param in_pos The next byte will be read from in[*in_pos].
500 * *in_pos is updated only if decoding succeeds.
501 * \param in_size Size of the input buffer; the first byte that
502 * won't be read is in[in_size].
503 * \param out Beginning of the output buffer
504 * \param out_pos The next byte will be written to out[*out_pos].
505 * *out_pos is updated only if encoding succeeds.
506 * \param out_size Size of the out buffer; the first byte into
507 * which no data is written to is out[out_size].
509 * \return - LZMA_OK: Decoding was successful.
510 * - LZMA_OPTIONS_ERROR
513 * - LZMA_BUF_ERROR: Output buffer was too small.
516 extern LZMA_API(lzma_ret) lzma_block_buffer_decode(
517 lzma_block *block, lzma_allocator *allocator,
518 const uint8_t *in, size_t *in_pos, size_t in_size,
519 uint8_t *out, size_t *out_pos, size_t out_size);