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author | David Oberhollenzer <david.oberhollenzer@sigma-star.at> | 2019-05-05 21:45:04 +0200 |
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committer | David Oberhollenzer <david.oberhollenzer@sigma-star.at> | 2019-05-05 21:45:04 +0200 |
commit | a5f604469d5cde8cb654e209f1ec30bf8e44b51e (patch) | |
tree | 58e41e92e9f25de67e21e40510eb3150dac31712 /include/compress.h | |
parent | c7f38d808144e8f82805a6b84bfe48740af31b14 (diff) |
Comment on all the things
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'include/compress.h')
-rw-r--r-- | include/compress.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/include/compress.h b/include/compress.h index ad193e8..5bb689b 100644 --- a/include/compress.h +++ b/include/compress.h @@ -11,15 +11,66 @@ typedef struct compressor_t compressor_t; +/** + * @struct compressor_t + * + * @brief Encapsultes a compressor with a simple interface to compress or + * uncompress/extract blocks of data + */ struct compressor_t { + /** + * @brief Compress or uncompress a chunk of data + * + * @param cmp A pointer to the compressor object + * @param in A pointer to the input buffer + * @param size The number of bytes in the input buffer to process + * @param out A pointer to the output buffer + * @param outsize The number of bytes available in the output buffer + * + * @return On success, the number of bytes written to the output + * buffer, -1 on failure, 0 if the output buffer was too small. + * The compressor also returns 0 if the compressed result ends + * up larger than the original input. + */ ssize_t (*do_block)(compressor_t *cmp, const uint8_t *in, size_t size, uint8_t *out, size_t outsize); + /** + * @brief Destroy a compressor object and free up all memory it uses + * + * @param cmp A pointer to the compressor object + */ void (*destroy)(compressor_t *stream); }; +/** + * @brief Check if a given compressor is available + * + * @memberof compressor_t + * + * This function checks if a given compressor is available, since some + * compressors may not be supported yet, or simply disabled in the + * compile configuration. + * + * @param id A SquashFS compressor id + * + * @return true if the given compressor is available + */ bool compressor_exists(E_SQFS_COMPRESSOR id); +/** + * @brief Create a compressor object + * + * @memberof compressor_t + * + * @param id A SquashFS compressor id + * @param compress true if the resulting object should compress data, false + * if it should actually extract already compressed blocks. + * @param block_size The configured block size for the SquashFS image. May be + * of interest to some compressors. + * + * @return A pointer to a new compressor object or NULL on failure. + */ compressor_t *compressor_create(E_SQFS_COMPRESSOR id, bool compress, size_t block_size); |