Impl __append_log (no compile)

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
Save commit

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
Save commit: on the way find_min_id_plog

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>