There's so many Duplicated read_string_from method in different
subsystem's implementation, so as read_u64_from/read_i64_from methods.
(1) Move the read_string_from method into `lib.rs`,
called by each subsystem implementation as needed.
(2) Refactor read_u[i]64_from method with the help Rust Generic f
unction `read_from` and wrapped by read_u64_from or read_i64_from.
fix: #20
Signed-off-by: LiYa'nan <oliverliyn@gmail.com>
Delete check_support and stop detecting subsystems by finding in the
root folders because the detecting method is not accurate.
Signed-off-by: Tim Zhang <tim@hyper.sh>
Use idiomatic Option::None to represent optional fields.
This enables updates where not all fields need to be specified.
Signed-off-by: Tim Zhang <tim@hyper.sh>
