Function read_request_with_limits 

pub fn read_request_with_limits<'a>(
    socket: &impl AsFd,
    storage: &'a mut [u8],
    limits: RequestLimits,
) -> Result<Request<'a>>

Read one request with inclusive logical quotas. Known policy exhaustion returns LimitExceeded; insufficient physical storage returns BufferTooSmall. A tied policy/capacity boundary is a policy failure. Gzip retains the complete wire body and original physical expansion slack. All storage is provisional on failure; discard it and close the socket.