3 * \brief .xz Block handling
9 * This file has been put into the public domain.
10 * You can do whatever you want with this file.
12 * See ../lzma.h for information about liblzma as a whole.
15 #ifndef LZMA_H_INTERNAL
16 # error Never include this file directly. Use <lzma.h> instead.
21 * \brief Options for the Block and Block Header encoders and decoders
23 * Different Block handling functions use different parts of this structure.
24 * Some read some members, other functions write, and some do both. Only the
25 * members listed for reading need to be initialized when the specified
26 * functions are called. The members marked for writing will be assigned
27 * new values at some point either by calling the given function or by
28 * later calls to lzma_code().
32 * \brief Block format version
34 * To prevent API and ABI breakages if new features are needed in
35 * Block, a version number is used to indicate which fields in this
36 * structure are in use. For now, version must always be zero.
37 * With non-zero version, most Block related functions will return
40 * The decoding functions will always set this to the lowest value
41 * that supports all the features indicated by the Block Header field.
42 * The application must check that the version number set by the
43 * decoding functions is supported by the application. Otherwise it
44 * is possible that the application will decode the Block incorrectly.
47 * - lzma_block_header_size()
48 * - lzma_block_header_encode()
49 * - lzma_block_compressed_size()
50 * - lzma_block_unpadded_size()
51 * - lzma_block_total_size()
52 * - lzma_block_encoder()
53 * - lzma_block_decoder()
54 * - lzma_block_buffer_encode()
55 * - lzma_block_buffer_decode()
58 * - lzma_block_header_decode()
63 * \brief Size of the Block Header field
65 * This is always a multiple of four.
68 * - lzma_block_header_encode()
69 * - lzma_block_header_decode()
70 * - lzma_block_compressed_size()
71 * - lzma_block_unpadded_size()
72 * - lzma_block_total_size()
73 * - lzma_block_decoder()
74 * - lzma_block_buffer_decode()
77 * - lzma_block_header_size()
78 * - lzma_block_buffer_encode()
81 # define LZMA_BLOCK_HEADER_SIZE_MIN 8
82 # define LZMA_BLOCK_HEADER_SIZE_MAX 1024
85 * \brief Type of integrity Check
87 * The Check ID is not stored into the Block Header, thus its value
88 * must be provided also when decoding.
91 * - lzma_block_header_encode()
92 * - lzma_block_header_decode()
93 * - lzma_block_compressed_size()
94 * - lzma_block_unpadded_size()
95 * - lzma_block_total_size()
96 * - lzma_block_encoder()
97 * - lzma_block_decoder()
98 * - lzma_block_buffer_encode()
99 * - lzma_block_buffer_decode()
104 * \brief Size of the Compressed Data in bytes
106 * Encoding: If this is not LZMA_VLI_UNKNOWN, Block Header encoder
107 * will store this value to the Block Header. Block encoder doesn't
108 * care about this value, but will set it once the encoding has been
111 * Decoding: If this is not LZMA_VLI_UNKNOWN, Block decoder will
112 * verify that the size of the Compressed Data field matches
115 * Usually you don't know this value when encoding in streamed mode,
116 * and thus cannot write this field into the Block Header.
118 * In non-streamed mode you can reserve space for this field before
119 * encoding the actual Block. After encoding the data, finish the
120 * Block by encoding the Block Header. Steps in detail:
122 * - Set compressed_size to some big enough value. If you don't know
123 * better, use LZMA_VLI_MAX, but remember that bigger values take
124 * more space in Block Header.
126 * - Call lzma_block_header_size() to see how much space you need to
127 * reserve for the Block Header.
129 * - Encode the Block using lzma_block_encoder() and lzma_code().
130 * It sets compressed_size to the correct value.
132 * - Use lzma_block_header_encode() to encode the Block Header.
133 * Because space was reserved in the first step, you don't need
134 * to call lzma_block_header_size() anymore, because due to
135 * reserving, header_size has to be big enough. If it is "too big",
136 * lzma_block_header_encode() will add enough Header Padding to
137 * make Block Header to match the size specified by header_size.
140 * - lzma_block_header_size()
141 * - lzma_block_header_encode()
142 * - lzma_block_compressed_size()
143 * - lzma_block_unpadded_size()
144 * - lzma_block_total_size()
145 * - lzma_block_decoder()
146 * - lzma_block_buffer_decode()
149 * - lzma_block_header_decode()
150 * - lzma_block_compressed_size()
151 * - lzma_block_encoder()
152 * - lzma_block_decoder()
153 * - lzma_block_buffer_encode()
154 * - lzma_block_buffer_decode()
156 lzma_vli compressed_size;
159 * \brief Uncompressed Size in bytes
161 * This is handled very similarly to compressed_size above.
163 * Unlike compressed_size, uncompressed_size is needed by fewer
164 * functions. This is because uncompressed_size isn't needed to
165 * validate that Block stays within proper limits.
168 * - lzma_block_header_size()
169 * - lzma_block_header_encode()
170 * - lzma_block_decoder()
171 * - lzma_block_buffer_decode()
174 * - lzma_block_header_decode()
175 * - lzma_block_encoder()
176 * - lzma_block_decoder()
177 * - lzma_block_buffer_encode()
178 * - lzma_block_buffer_decode()
180 lzma_vli uncompressed_size;
183 * \brief Array of filters
185 * There can be 1-4 filters. The end of the array is marked with
186 * .id = LZMA_VLI_UNKNOWN.
189 * - lzma_block_header_size()
190 * - lzma_block_header_encode()
191 * - lzma_block_encoder()
192 * - lzma_block_decoder()
193 * - lzma_block_buffer_encode()
194 * - lzma_block_buffer_decode()
197 * - lzma_block_header_decode(): Note that this does NOT free()
198 * the old filter options structures. All unused filters[] will
199 * have .id == LZMA_VLI_UNKNOWN and .options == NULL. If
200 * decoding fails, all filters[] are guaranteed to be
201 * LZMA_VLI_UNKNOWN and NULL.
203 * \note Because of the array is terminated with
204 * .id = LZMA_VLI_UNKNOWN, the actual array must
205 * have LZMA_FILTERS_MAX + 1 members or the Block
206 * Header decoder will overflow the buffer.
208 lzma_filter *filters;
211 * Reserved space to allow possible future extensions without
212 * breaking the ABI. You should not touch these, because the names
213 * of these variables may change. These are and will never be used
214 * with the currently supported options, so it is safe to leave these
220 uint32_t reserved_int1;
221 uint32_t reserved_int2;
222 lzma_vli reserved_int3;
223 lzma_vli reserved_int4;
224 lzma_vli reserved_int5;
225 lzma_vli reserved_int6;
226 lzma_vli reserved_int7;
227 lzma_vli reserved_int8;
228 lzma_reserved_enum reserved_enum1;
229 lzma_reserved_enum reserved_enum2;
230 lzma_reserved_enum reserved_enum3;
231 lzma_reserved_enum reserved_enum4;
232 lzma_bool reserved_bool1;
233 lzma_bool reserved_bool2;
234 lzma_bool reserved_bool3;
235 lzma_bool reserved_bool4;
236 lzma_bool reserved_bool5;
237 lzma_bool reserved_bool6;
238 lzma_bool reserved_bool7;
239 lzma_bool reserved_bool8;
245 * \brief Decode the Block Header Size field
247 * To decode Block Header using lzma_block_header_decode(), the size of the
248 * Block Header has to be known and stored into lzma_block.header_size.
249 * The size can be calculated from the first byte of a Block using this macro.
250 * Note that if the first byte is 0x00, it indicates beginning of Index; use
251 * this macro only when the byte is not 0x00.
253 * There is no encoding macro, because Block Header encoder is enough for that.
255 #define lzma_block_header_size_decode(b) (((uint32_t)(b) + 1) * 4)
259 * \brief Calculate Block Header Size
261 * Calculate the minimum size needed for the Block Header field using the
262 * settings specified in the lzma_block structure. Note that it is OK to
263 * increase the calculated header_size value as long as it is a multiple of
264 * four and doesn't exceed LZMA_BLOCK_HEADER_SIZE_MAX. Increasing header_size
265 * just means that lzma_block_header_encode() will add Header Padding.
267 * \return - LZMA_OK: Size calculated successfully and stored to
268 * block->header_size.
269 * - LZMA_OPTIONS_ERROR: Unsupported version, filters or
271 * - LZMA_PROG_ERROR: Invalid values like compressed_size == 0.
273 * \note This doesn't check that all the options are valid i.e. this
274 * may return LZMA_OK even if lzma_block_header_encode() or
275 * lzma_block_encoder() would fail. If you want to validate the
276 * filter chain, consider using lzma_memlimit_encoder() which as
277 * a side-effect validates the filter chain.
279 extern LZMA_API(lzma_ret) lzma_block_header_size(lzma_block *block)
280 lzma_attr_warn_unused_result;
284 * \brief Encode Block Header
286 * The caller must have calculated the size of the Block Header already with
287 * lzma_block_header_size(). If larger value than the one calculated by
288 * lzma_block_header_size() is used, the Block Header will be padded to the
291 * \param out Beginning of the output buffer. This must be
292 * at least block->header_size bytes.
293 * \param block Block options to be encoded.
295 * \return - LZMA_OK: Encoding was successful. block->header_size
296 * bytes were written to output buffer.
297 * - LZMA_OPTIONS_ERROR: Invalid or unsupported options.
298 * - LZMA_PROG_ERROR: Invalid arguments, for example
299 * block->header_size is invalid or block->filters is NULL.
301 extern LZMA_API(lzma_ret) lzma_block_header_encode(
302 const lzma_block *block, uint8_t *out)
303 lzma_attr_warn_unused_result;
307 * \brief Decode Block Header
309 * The size of the Block Header must have already been decoded with
310 * lzma_block_header_size_decode() macro and stored to block->header_size.
311 * block->filters must have been allocated, but not necessarily initialized.
312 * Possible existing filter options are _not_ freed.
314 * \param block Destination for block options with header_size
315 * properly initialized.
316 * \param allocator lzma_allocator for custom allocator functions.
317 * Set to NULL to use malloc() (and also free()
318 * if an error occurs).
319 * \param in Beginning of the input buffer. This must be
320 * at least block->header_size bytes.
322 * \return - LZMA_OK: Decoding was successful. block->header_size
323 * bytes were read from the input buffer.
324 * - LZMA_OPTIONS_ERROR: The Block Header specifies some
325 * unsupported options such as unsupported filters.
326 * - LZMA_DATA_ERROR: Block Header is corrupt, for example,
327 * the CRC32 doesn't match.
328 * - LZMA_PROG_ERROR: Invalid arguments, for example
329 * block->header_size is invalid or block->filters is NULL.
331 extern LZMA_API(lzma_ret) lzma_block_header_decode(lzma_block *block,
332 lzma_allocator *allocator, const uint8_t *in)
333 lzma_attr_warn_unused_result;
337 * \brief Validate and set Compressed Size according to Unpadded Size
339 * Block Header stores Compressed Size, but Index has Unpadded Size. If the
340 * application has already parsed the Index and is now decoding Blocks,
341 * it can calculate Compressed Size from Unpadded Size. This function does
342 * exactly that with error checking:
344 * - Compressed Size calculated from Unpadded Size must be positive integer,
345 * that is, Unpadded Size must be big enough that after Block Header and
346 * Check fields there's still at least one byte for Compressed Size.
348 * - If Compressed Size was present in Block Header, the new value
349 * calculated from Unpadded Size is compared against the value
352 * \note This function must be called _after_ decoding the Block Header
353 * field so that it can properly validate Compressed Size if it
354 * was present in Block Header.
356 * \return - LZMA_OK: block->compressed_size was set successfully.
357 * - LZMA_DATA_ERROR: unpadded_size is too small compared to
358 * block->header_size and lzma_check_size(block->check).
359 * - LZMA_PROG_ERROR: Some values are invalid. For example,
360 * block->header_size must be a multiple of four and
361 * between 8 and 1024 inclusive.
363 extern LZMA_API(lzma_ret) lzma_block_compressed_size(
364 lzma_block *block, lzma_vli unpadded_size)
365 lzma_attr_warn_unused_result;
369 * \brief Calculate Unpadded Size
371 * The Index field stores Unpadded Size and Uncompressed Size. The latter
372 * can be taken directly from the lzma_block structure after coding a Block,
373 * but Unpadded Size needs to be calculated from Block Header Size,
374 * Compressed Size, and size of the Check field. This is where this function
377 * \return Unpadded Size on success, or zero on error.
379 extern LZMA_API(lzma_vli) lzma_block_unpadded_size(const lzma_block *block)
384 * \brief Calculate the total encoded size of a Block
386 * This is equivalent to lzma_block_unpadded_size() except that the returned
387 * value includes the size of the Block Padding field.
389 * \return On success, total encoded size of the Block. On error,
392 extern LZMA_API(lzma_vli) lzma_block_total_size(const lzma_block *block)
397 * \brief Initialize .xz Block encoder
399 * Valid actions for lzma_code() are LZMA_RUN, LZMA_SYNC_FLUSH (only if the
400 * filter chain supports it), and LZMA_FINISH.
402 * \return - LZMA_OK: All good, continue with lzma_code().
404 * - LZMA_OPTIONS_ERROR
405 * - LZMA_UNSUPPORTED_CHECK: block->check specfies a Check ID
406 * that is not supported by this buid of liblzma. Initializing
407 * the encoder failed.
410 extern LZMA_API(lzma_ret) lzma_block_encoder(
411 lzma_stream *strm, lzma_block *block)
412 lzma_attr_warn_unused_result;
416 * \brief Initialize .xz Block decoder
418 * Valid actions for lzma_code() are LZMA_RUN and LZMA_FINISH. Using
419 * LZMA_FINISH is not required. It is supported only for convenience.
421 * \return - LZMA_OK: All good, continue with lzma_code().
422 * - LZMA_UNSUPPORTED_CHECK: Initialization was successful, but
423 * the given Check ID is not supported, thus Check will be
428 extern LZMA_API(lzma_ret) lzma_block_decoder(
429 lzma_stream *strm, lzma_block *block)
430 lzma_attr_warn_unused_result;
434 * \brief Calculate maximum output buffer size for single-call encoding
436 * This is equivalent to lzma_stream_buffer_bound() but for .xz Blocks.
437 * See the documentation of lzma_stream_buffer_bound().
439 extern LZMA_API(size_t) lzma_block_buffer_bound(size_t uncompressed_size);
443 * \brief Single-call .xz Block encoder
445 * In contrast to the multi-call encoder initialized with
446 * lzma_block_encoder(), this function encodes also the Block Header. This
447 * is required to make it possible to write appropriate Block Header also
448 * in case the data isn't compressible, and different filter chain has to be
449 * used to encode the data in uncompressed form using uncompressed chunks
450 * of the LZMA2 filter.
452 * When the data isn't compressible, header_size, compressed_size, and
453 * uncompressed_size are set just like when the data was compressible, but
454 * it is possible that header_size is too small to hold the filter chain
455 * specified in block->filters, because that isn't necessarily the filter
456 * chain that was actually used to encode the data. lzma_block_unpadded_size()
457 * still works normally, because it doesn't read the filters array.
459 * \param block Block options: block->version, block->check,
460 * and block->filters must be initialized.
461 * \param allocator lzma_allocator for custom allocator functions.
462 * Set to NULL to use malloc() and free().
463 * \param in Beginning of the input buffer
464 * \param in_size Size of the input buffer
465 * \param out Beginning of the output buffer
466 * \param out_pos The next byte will be written to out[*out_pos].
467 * *out_pos is updated only if encoding succeeds.
468 * \param out_size Size of the out buffer; the first byte into
469 * which no data is written to is out[out_size].
471 * \return - LZMA_OK: Encoding was successful.
472 * - LZMA_BUF_ERROR: Not enough output buffer space.
473 * - LZMA_OPTIONS_ERROR
478 extern LZMA_API(lzma_ret) lzma_block_buffer_encode(
479 lzma_block *block, lzma_allocator *allocator,
480 const uint8_t *in, size_t in_size,
481 uint8_t *out, size_t *out_pos, size_t out_size)
482 lzma_attr_warn_unused_result;
486 * \brief Single-call .xz Block decoder
488 * This is single-call equivalent of lzma_block_decoder(), and requires that
489 * the caller has already decoded Block Header and checked its memory usage.
491 * \param block Block options just like with lzma_block_decoder().
492 * \param allocator lzma_allocator for custom allocator functions.
493 * Set to NULL to use malloc() and free().
494 * \param in Beginning of the input buffer
495 * \param in_pos The next byte will be read from in[*in_pos].
496 * *in_pos is updated only if decoding succeeds.
497 * \param in_size Size of the input buffer; the first byte that
498 * won't be read is in[in_size].
499 * \param out Beginning of the output buffer
500 * \param out_pos The next byte will be written to out[*out_pos].
501 * *out_pos is updated only if encoding succeeds.
502 * \param out_size Size of the out buffer; the first byte into
503 * which no data is written to is out[out_size].
505 * \return - LZMA_OK: Decoding was successful.
506 * - LZMA_OPTIONS_ERROR
509 * - LZMA_BUF_ERROR: Output buffer was too small.
512 extern LZMA_API(lzma_ret) lzma_block_buffer_decode(
513 lzma_block *block, lzma_allocator *allocator,
514 const uint8_t *in, size_t *in_pos, size_t in_size,
515 uint8_t *out, size_t *out_pos, size_t out_size);