diff options
Diffstat (limited to 'src/liblzma/api/lzma/block.h')
| -rw-r--r-- | src/liblzma/api/lzma/block.h | 578 |
1 files changed, 578 insertions, 0 deletions
diff --git a/src/liblzma/api/lzma/block.h b/src/liblzma/api/lzma/block.h new file mode 100644 index 0000000..082e558 --- /dev/null +++ b/src/liblzma/api/lzma/block.h @@ -0,0 +1,578 @@ +/** + * \file lzma/block.h + * \brief .xz Block handling + */ + +/* + * 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 + + +/** + * \brief Options for the Block and Block Header encoders and decoders + * + * Different Block handling functions use different parts of this structure. + * Some read some members, other functions write, and some do both. Only the + * members listed for reading need to be initialized when the specified + * functions are called. The members marked for writing will be assigned + * new values at some point either by calling the given function or by + * later calls to lzma_code(). + */ +typedef struct { + /** + * \brief Block format version + * + * To prevent API and ABI breakages when new features are needed, + * a version number is used to indicate which fields in this + * structure are in use: + * - liblzma >= 5.0.0: version = 0 is supported. + * - liblzma >= 5.1.4beta: Support for version = 1 was added, + * which adds the ignore_check field. + * + * If version is greater than one, most Block related functions + * will return LZMA_OPTIONS_ERROR (lzma_block_header_decode() works + * with any version value). + * + * Read by: + * - All functions that take pointer to lzma_block as argument, + * including lzma_block_header_decode(). + * + * Written by: + * - lzma_block_header_decode() + */ + uint32_t version; + + /** + * \brief Size of the Block Header field + * + * This is always a multiple of four. + * + * Read by: + * - lzma_block_header_encode() + * - lzma_block_header_decode() + * - lzma_block_compressed_size() + * - lzma_block_unpadded_size() + * - lzma_block_total_size() + * - lzma_block_decoder() + * - lzma_block_buffer_decode() + * + * Written by: + * - lzma_block_header_size() + * - lzma_block_buffer_encode() + */ + uint32_t header_size; +# define LZMA_BLOCK_HEADER_SIZE_MIN 8 +# define LZMA_BLOCK_HEADER_SIZE_MAX 1024 + + /** + * \brief Type of integrity Check + * + * The Check ID is not stored into the Block Header, thus its value + * must be provided also when decoding. + * + * Read by: + * - lzma_block_header_encode() + * - lzma_block_header_decode() + * - lzma_block_compressed_size() + * - lzma_block_unpadded_size() + * - lzma_block_total_size() + * - lzma_block_encoder() + * - lzma_block_decoder() + * - lzma_block_buffer_encode() + * - lzma_block_buffer_decode() + */ + lzma_check check; + + /** + * \brief Size of the Compressed Data in bytes + * + * Encoding: If this is not LZMA_VLI_UNKNOWN, Block Header encoder + * will store this value to the Block Header. Block encoder doesn't + * care about this value, but will set it once the encoding has been + * finished. + * + * Decoding: If this is not LZMA_VLI_UNKNOWN, Block decoder will + * verify that the size of the Compressed Data field matches + * compressed_size. + * + * Usually you don't know this value when encoding in streamed mode, + * and thus cannot write this field into the Block Header. + * + * In non-streamed mode you can reserve space for this field before + * encoding the actual Block. After encoding the data, finish the + * Block by encoding the Block Header. Steps in detail: + * + * - Set compressed_size to some big enough value. If you don't know + * better, use LZMA_VLI_MAX, but remember that bigger values take + * more space in Block Header. + * + * - Call lzma_block_header_size() to see how much space you need to + * reserve for the Block Header. + * + * - Encode the Block using lzma_block_encoder() and lzma_code(). + * It sets compressed_size to the correct value. + * + * - Use lzma_block_header_encode() to encode the Block Header. + * Because space was reserved in the first step, you don't need + * to call lzma_block_header_size() anymore, because due to + * reserving, header_size has to be big enough. If it is "too big", + * lzma_block_header_encode() will add enough Header Padding to + * make Block Header to match the size specified by header_size. + * + * Read by: + * - lzma_block_header_size() + * - lzma_block_header_encode() + * - lzma_block_compressed_size() + * - lzma_block_unpadded_size() + * - lzma_block_total_size() + * - lzma_block_decoder() + * - lzma_block_buffer_decode() + * + * Written by: + * - lzma_block_header_decode() + * - lzma_block_compressed_size() + * - lzma_block_encoder() + * - lzma_block_decoder() + * - lzma_block_buffer_encode() + * - lzma_block_buffer_decode() + */ + lzma_vli compressed_size; + + /** + * \brief Uncompressed Size in bytes + * + * This is handled very similarly to compressed_size above. + * + * uncompressed_size is needed by fewer functions than + * compressed_size. This is because uncompressed_size isn't + * needed to validate that Block stays within proper limits. + * + * Read by: + * - lzma_block_header_size() + * - lzma_block_header_encode() + * - lzma_block_decoder() + * - lzma_block_buffer_decode() + * + * Written by: + * - lzma_block_header_decode() + * - lzma_block_encoder() + * - lzma_block_decoder() + * - lzma_block_buffer_encode() + * - lzma_block_buffer_decode() + */ + lzma_vli uncompressed_size; + + /** + * \brief Array of filters + * + * There can be 1-4 filters. The end of the array is marked with + * .id = LZMA_VLI_UNKNOWN. + * + * Read by: + * - lzma_block_header_size() + * - lzma_block_header_encode() + * - lzma_block_encoder() + * - lzma_block_decoder() + * - lzma_block_buffer_encode() + * - lzma_block_buffer_decode() + * + * Written by: + * - lzma_block_header_decode(): Note that this does NOT free() + * the old filter options structures. All unused filters[] will + * have .id == LZMA_VLI_UNKNOWN and .options == NULL. If + * decoding fails, all filters[] are guaranteed to be + * LZMA_VLI_UNKNOWN and NULL. + * + * \note Because of the array is terminated with + * .id = LZMA_VLI_UNKNOWN, the actual array must + * have LZMA_FILTERS_MAX + 1 members or the Block + * Header decoder will overflow the buffer. + */ + lzma_filter *filters; + + /** + * \brief Raw value stored in the Check field + * + * After successful coding, the first lzma_check_size(check) bytes + * of this array contain the raw value stored in the Check field. + * + * Note that CRC32 and CRC64 are stored in little endian byte order. + * Take it into account if you display the Check values to the user. + * + * Written by: + * - lzma_block_encoder() + * - lzma_block_decoder() + * - lzma_block_buffer_encode() + * - lzma_block_buffer_decode() + */ + uint8_t raw_check[LZMA_CHECK_SIZE_MAX]; + + /* + * 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. + */ + void *reserved_ptr1; + void *reserved_ptr2; + void *reserved_ptr3; + uint32_t reserved_int1; + uint32_t reserved_int2; + lzma_vli reserved_int3; + lzma_vli reserved_int4; + lzma_vli reserved_int5; + lzma_vli reserved_int6; + lzma_vli reserved_int7; + lzma_vli reserved_int8; + lzma_reserved_enum reserved_enum1; + lzma_reserved_enum reserved_enum2; + lzma_reserved_enum reserved_enum3; + lzma_reserved_enum reserved_enum4; + + /** + * \brief A flag to Block decoder to not verify the Check field + * + * This field is supported by liblzma >= 5.1.4beta if .version >= 1. + * + * If this is set to true, the integrity check won't be calculated + * and verified. Unless you know what you are doing, you should + * leave this to false. (A reason to set this to true is when the + * file integrity is verified externally anyway and you want to + * speed up the decompression, which matters mostly when using + * SHA-256 as the integrity check.) + * + * If .version >= 1, read by: + * - lzma_block_decoder() + * - lzma_block_buffer_decode() + * + * Written by (.version is ignored): + * - lzma_block_header_decode() always sets this to false + */ + lzma_bool ignore_check; + + lzma_bool reserved_bool2; + lzma_bool reserved_bool3; + lzma_bool reserved_bool4; + lzma_bool reserved_bool5; + lzma_bool reserved_bool6; + lzma_bool reserved_bool7; + lzma_bool reserved_bool8; + +} lzma_block; + + +/** + * \brief Decode the Block Header Size field + * + * To decode Block Header using lzma_block_header_decode(), the size of the + * Block Header has to be known and stored into lzma_block.header_size. + * The size can be calculated from the first byte of a Block using this macro. + * Note that if the first byte is 0x00, it indicates beginning of Index; use + * this macro only when the byte is not 0x00. + * + * There is no encoding macro, because Block Header encoder is enough for that. + */ +#define lzma_block_header_size_decode(b) (((uint32_t)(b) + 1) * 4) + + +/** + * \brief Calculate Block Header Size + * + * Calculate the minimum size needed for the Block Header field using the + * settings specified in the lzma_block structure. Note that it is OK to + * increase the calculated header_size value as long as it is a multiple of + * four and doesn't exceed LZMA_BLOCK_HEADER_SIZE_MAX. Increasing header_size + * just means that lzma_block_header_encode() will add Header Padding. + * + * \return - LZMA_OK: Size calculated successfully and stored to + * block->header_size. + * - LZMA_OPTIONS_ERROR: Unsupported version, filters or + * filter options. + * - LZMA_PROG_ERROR: Invalid values like compressed_size == 0. + * + * \note This doesn't check that all the options are valid i.e. this + * may return LZMA_OK even if lzma_block_header_encode() or + * lzma_block_encoder() would fail. If you want to validate the + * filter chain, consider using lzma_memlimit_encoder() which as + * a side-effect validates the filter chain. + */ +extern LZMA_API(lzma_ret) lzma_block_header_size(lzma_block *block) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Encode Block Header + * + * The caller must have calculated the size of the Block Header already with + * lzma_block_header_size(). If a value larger than the one calculated by + * lzma_block_header_size() is used, the Block Header will be padded to the + * specified size. + * + * \param out Beginning of the output buffer. This must be + * at least block->header_size bytes. + * \param block Block options to be encoded. + * + * \return - LZMA_OK: Encoding was successful. block->header_size + * bytes were written to output buffer. + * - LZMA_OPTIONS_ERROR: Invalid or unsupported options. + * - LZMA_PROG_ERROR: Invalid arguments, for example + * block->header_size is invalid or block->filters is NULL. + */ +extern LZMA_API(lzma_ret) lzma_block_header_encode( + const lzma_block *block, uint8_t *out) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Decode Block Header + * + * block->version should (usually) be set to the highest value supported + * by the application. If the application sets block->version to a value + * higher than supported by the current liblzma version, this function will + * downgrade block->version to the highest value supported by it. Thus one + * should check the value of block->version after calling this function if + * block->version was set to a non-zero value and the application doesn't + * otherwise know that the liblzma version being used is new enough to + * support the specified block->version. + * + * The size of the Block Header must have already been decoded with + * lzma_block_header_size_decode() macro and stored to block->header_size. + * + * The integrity check type from Stream Header must have been stored + * to block->check. + * + * block->filters must have been allocated, but they don't need to be + * initialized (possible existing filter options are not freed). + * + * \param block Destination for Block options. + * \param allocator lzma_allocator for custom allocator functions. + * Set to NULL to use malloc() (and also free() + * if an error occurs). + * \param in Beginning of the input buffer. This must be + * at least block->header_size bytes. + * + * \return - LZMA_OK: Decoding was successful. block->header_size + * bytes were read from the input buffer. + * - LZMA_OPTIONS_ERROR: The Block Header specifies some + * unsupported options such as unsupported filters. This can + * happen also if block->version was set to a too low value + * compared to what would be required to properly represent + * the information stored in the Block Header. + * - LZMA_DATA_ERROR: Block Header is corrupt, for example, + * the CRC32 doesn't match. + * - LZMA_PROG_ERROR: Invalid arguments, for example + * block->header_size is invalid or block->filters is NULL. + */ +extern LZMA_API(lzma_ret) lzma_block_header_decode(lzma_block *block, + const lzma_allocator *allocator, const uint8_t *in) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Validate and set Compressed Size according to Unpadded Size + * + * Block Header stores Compressed Size, but Index has Unpadded Size. If the + * application has already parsed the Index and is now decoding Blocks, + * it can calculate Compressed Size from Unpadded Size. This function does + * exactly that with error checking: + * + * - Compressed Size calculated from Unpadded Size must be positive integer, + * that is, Unpadded Size must be big enough that after Block Header and + * Check fields there's still at least one byte for Compressed Size. + * + * - If Compressed Size was present in Block Header, the new value + * calculated from Unpadded Size is compared against the value + * from Block Header. + * + * \note This function must be called _after_ decoding the Block Header + * field so that it can properly validate Compressed Size if it + * was present in Block Header. + * + * \return - LZMA_OK: block->compressed_size was set successfully. + * - LZMA_DATA_ERROR: unpadded_size is too small compared to + * block->header_size and lzma_check_size(block->check). + * - LZMA_PROG_ERROR: Some values are invalid. For example, + * block->header_size must be a multiple of four and + * between 8 and 1024 inclusive. + */ +extern LZMA_API(lzma_ret) lzma_block_compressed_size( + lzma_block *block, lzma_vli unpadded_size) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Calculate Unpadded Size + * + * The Index field stores Unpadded Size and Uncompressed Size. The latter + * can be taken directly from the lzma_block structure after coding a Block, + * but Unpadded Size needs to be calculated from Block Header Size, + * Compressed Size, and size of the Check field. This is where this function + * is needed. + * + * \return Unpadded Size on success, or zero on error. + */ +extern LZMA_API(lzma_vli) lzma_block_unpadded_size(const lzma_block *block) + lzma_nothrow lzma_attr_pure; + + +/** + * \brief Calculate the total encoded size of a Block + * + * This is equivalent to lzma_block_unpadded_size() except that the returned + * value includes the size of the Block Padding field. + * + * \return On success, total encoded size of the Block. On error, + * zero is returned. + */ +extern LZMA_API(lzma_vli) lzma_block_total_size(const lzma_block *block) + lzma_nothrow lzma_attr_pure; + + +/** + * \brief Initialize .xz Block encoder + * + * Valid actions for lzma_code() are LZMA_RUN, LZMA_SYNC_FLUSH (only if the + * filter chain supports it), and LZMA_FINISH. + * + * \return - LZMA_OK: All good, continue with lzma_code(). + * - LZMA_MEM_ERROR + * - LZMA_OPTIONS_ERROR + * - LZMA_UNSUPPORTED_CHECK: block->check specifies a Check ID + * that is not supported by this build of liblzma. Initializing + * the encoder failed. + * - LZMA_PROG_ERROR + */ +extern LZMA_API(lzma_ret) lzma_block_encoder( + lzma_stream *strm, lzma_block *block) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Initialize .xz Block decoder + * + * Valid actions for lzma_code() are LZMA_RUN and LZMA_FINISH. Using + * LZMA_FINISH is not required. It is supported only for convenience. + * + * \return - LZMA_OK: All good, continue with lzma_code(). + * - LZMA_PROG_ERROR + * - LZMA_MEM_ERROR + */ +extern LZMA_API(lzma_ret) lzma_block_decoder( + lzma_stream *strm, lzma_block *block) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Calculate maximum output size for single-call Block encoding + * + * This is equivalent to lzma_stream_buffer_bound() but for .xz Blocks. + * See the documentation of lzma_stream_buffer_bound(). + */ +extern LZMA_API(size_t) lzma_block_buffer_bound(size_t uncompressed_size) + lzma_nothrow; + + +/** + * \brief Single-call .xz Block encoder + * + * In contrast to the multi-call encoder initialized with + * lzma_block_encoder(), this function encodes also the Block Header. This + * is required to make it possible to write appropriate Block Header also + * in case the data isn't compressible, and different filter chain has to be + * used to encode the data in uncompressed form using uncompressed chunks + * of the LZMA2 filter. + * + * When the data isn't compressible, header_size, compressed_size, and + * uncompressed_size are set just like when the data was compressible, but + * it is possible that header_size is too small to hold the filter chain + * specified in block->filters, because that isn't necessarily the filter + * chain that was actually used to encode the data. lzma_block_unpadded_size() + * still works normally, because it doesn't read the filters array. + * + * \param block Block options: block->version, block->check, + * and block->filters must have been initialized. + * \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_block_buffer_encode( + lzma_block *block, 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 Single-call uncompressed .xz Block encoder + * + * This is like lzma_block_buffer_encode() except this doesn't try to + * compress the data and instead encodes the data using LZMA2 uncompressed + * chunks. The required output buffer size can be determined with + * lzma_block_buffer_bound(). + * + * Since the data won't be compressed, this function ignores block->filters. + * This function doesn't take lzma_allocator because this function doesn't + * allocate any memory from the heap. + */ +extern LZMA_API(lzma_ret) lzma_block_uncomp_encode(lzma_block *block, + 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 Single-call .xz Block decoder + * + * This is single-call equivalent of lzma_block_decoder(), and requires that + * the caller has already decoded Block Header and checked its memory usage. + * + * \param block Block options just like with lzma_block_decoder(). + * \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 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: Decoding was successful. + * - LZMA_OPTIONS_ERROR + * - LZMA_DATA_ERROR + * - LZMA_MEM_ERROR + * - LZMA_BUF_ERROR: Output buffer was too small. + * - LZMA_PROG_ERROR + */ +extern LZMA_API(lzma_ret) lzma_block_buffer_decode( + lzma_block *block, 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; |