diff options
Diffstat (limited to 'src/liblzma/api/lzma/block.h')
| -rw-r--r-- | src/liblzma/api/lzma/block.h | 39 |
1 files changed, 17 insertions, 22 deletions
diff --git a/src/liblzma/api/lzma/block.h b/src/liblzma/api/lzma/block.h index 10e97446..68f6755b 100644 --- a/src/liblzma/api/lzma/block.h +++ b/src/liblzma/api/lzma/block.h @@ -32,27 +32,14 @@ typedef struct { * \brief Block format version * * To prevent API and ABI breakages if new features are needed in - * Block, a version number is used to indicate which fields in this - * structure are in use. For now, version must always be zero. - * With non-zero version, most Block related functions will return - * LZMA_OPTIONS_ERROR. - * - * The decoding functions will always set this to the lowest value - * that supports all the features indicated by the Block Header field. - * The application must check that the version number set by the - * decoding functions is supported by the application. Otherwise it - * is possible that the application will decode the Block incorrectly. + * the Block field, a version number is used to indicate which + * fields in this structure are in use. For now, version must always + * be zero. With non-zero version, most Block related functions will + * return LZMA_OPTIONS_ERROR. * * Read by: - * - lzma_block_header_size() - * - lzma_block_header_encode() - * - 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() + * - All functions that take pointer to lzma_block as argument, + * including lzma_block_header_decode(). * * Written by: * - lzma_block_header_decode() @@ -323,13 +310,18 @@ extern LZMA_API(lzma_ret) lzma_block_header_encode( /** * \brief Decode Block Header * + * block->version should be set to the highest value supported by the + * application; currently the only possible version is zero. This function + * will set version to the lowest value that still supports all the features + * required by the Block Header. + * * The size of the Block Header must have already been decoded with * lzma_block_header_size_decode() macro and stored to block->header_size. + * * block->filters must have been allocated, but not necessarily initialized. * Possible existing filter options are _not_ freed. * - * \param block Destination for block options with header_size - * properly initialized. + * \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). @@ -339,7 +331,10 @@ extern LZMA_API(lzma_ret) lzma_block_header_encode( * \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. + * 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 |