pub fn read_message<R, T>(r: &mut R) -> Result<Option<T>>where
R: Read,
T: DeserializeOwned,Expand description
Read a length-prefixed JSON message from a stream.
Wire format: [u8; 4] little-endian length, then length bytes
of UTF-8 JSON. Returns Ok(None) on clean EOF, Err on truncated
reads or malformed JSON.