[fuse-devel] read(..) vs read_buf(..) ***HELP***

[Joachim S. <js...@la...>]

dear fuse-developers,

=== what is read_buf(..) and how is it supposed to be working ===
i was looking at the fuse.h source code documentation and the 
fusexmp_fh.c implementation. but still i don't understand what 
read_buf(..) is supposed to be doing.

is there another example for how to use read_buf(..)?


=== my client wants read_buf(..) but i want to use read(..) ===
my current FUSE client implementation wants to use read_buf(..) and not 
read(..). why is that?

i really don't understand why hello.c uses read(..) and my 
implementation, which is basically a 1:1 copy of hello.c, wants to use 
read_buf(..) instead.

i hope someone can help me!

best wishes,
joachim





=== function signatures of read(..) and read_buf(..) ===

int read(const char *path, char *buf, size_t size, off_t offset, struct 
fuse_file_info *fileInfo) {
    ...
}

	/** Store data from an open file in a buffer
	 *
	 * Similar to the read() method, but data is stored and
	 * returned in a generic buffer.
	 *
	 * No actual copying of data has to take place, the source
	 * file descriptor may simply be stored in the buffer for
	 * later data transfer.
	 *
	 * The buffer must be allocated dynamically and stored at the
	 * location pointed to by bufp.  If the buffer contains memory
	 * regions, they too must be allocated using malloc().  The
	 * allocated memory will be freed by the caller.
	 *
	 * Introduced in version 2.9
	 */
int read_buf(const char *path, struct fuse_bufvec **bufp, size_t size, 
off_t off, struct fuse_file_info *fileInfo) {
    ...
}