From 428aa363dd2b44756a5b16aa17e8c2030de801a0 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Sun, 15 Sep 2019 20:40:01 +0200 Subject: Move condensed-sparse-file handling to libsquashfs Add another helper function for getting a blocks from a condensed sparse file, then rewrite the data writer to use that instead, using an sqfs_file_t pointer instead of direct file i/o. Signed-off-by: David Oberhollenzer --- include/sqfs/io.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'include/sqfs') diff --git a/include/sqfs/io.h b/include/sqfs/io.h index cf6f1fa..bbc3da9 100644 --- a/include/sqfs/io.h +++ b/include/sqfs/io.h @@ -189,6 +189,35 @@ SQFS_API int sqfs_file_create_block(sqfs_file_t *file, uint64_t offset, size_t size, void *user, uint32_t flags, sqfs_block_t **out); +/** + * @brief Read a chunk from a condensed version of a sparse file and turn it + * into a block that can be fed to a block processor. + * + * @member sqfs_file_t + * + * This function works on condensed sparse files, i.e. a sparse file that had + * its holdes removed. The given mapping describes the original data region + * that are actually packed next to each other. The function emulates the + * orignal sparse file by zero-initializing the block data, then figuring + * out which regions overlap the block, working out their physical location and + * stitching the block together. + * + * @param file A pointer to a file implementation. + * @param offset A byte offset into the file. + * @param size The number of bytes to read, starting at the given offset. + * @param user A user pointer to set for the block. + * @param flags The flags to store in the newly created block. + * @param map Describes the data regions of the original sparse file. + * @param out Returns a pointer to a block on success. + * + * @return Zero on success, an @ref E_SQFS_ERROR identifier on failure. + */ +SQFS_API int sqfs_file_create_block_dense(sqfs_file_t *file, uint64_t offset, + size_t size, void *user, + uint32_t flags, + const sqfs_sparse_map_t *map, + sqfs_block_t **out); + #ifdef __cplusplus } #endif -- cgit v1.2.3