Function read_message 

pub fn read_message<R: BufRead>(
    reader: &mut R,
    limit: usize,
) -> Result<Option<Incoming>, FrameError>

Reads one line of at most limit bytes. Ok(None) is the host closing its end. A line over the limit is drained to its newline and refused.

Errors

Returns the overlong, not-JSON, not-a-request or stream failure.