fn read_full(
stream: &mut UnixStream,
buf: &mut [u8],
may_be_quiet: bool,
) -> Result<Filled, String>Expand description
Fill buf from the stream.
Progress survives the poll timeout. The stream answers a read with
nothing available at any point - a frame’s body arrives in many chunks,
and the reader polls so it can look at its stop flag - so a timeout
mid-frame resumes where it left off rather than failing the frame. Only a
frame’s FIRST byte may report Filled::Quiet: once a frame has begun,
nothing arriving for STALL is a wedge.