Method read

api/src/terminal/ldisc.rs:328–370

(&mut self, buf: &mut [u8])

    }

    pub fn read(&mut self, buf: &mut [u8]) -> AxResult<usize> {
        if buf.is_empty() {
            return Ok(0);
        }
        if matches!(self.processor, Processor::None(_, _)) {
            let read = self.buf_rx.pop_slice(buf);
            return if read == 0 {
                Err(AxError::WouldBlock)
            } else {
                Ok(read)
            };
        }

        let term = self.terminal.termios.lock().clone();
        let vmin = if term.canonical() {
            1
        } else {
            let vtime = term.special_char(VTIME);
            if vtime > 0 {
                todo!();
            }
            term.special_char(VMIN) as usize
        };

        if buf.len() < vmin as usize {
            return Err(AxError::WouldBlock);
        }

        let mut total_read = 0;
        let set = match &self.processor {
            Processor::Manual(_) => None,
            Processor::External(set) => Some(set),
            _ => unreachable!(),
        };
        let pollable = WaitPollable(set);
        block_on(poll_io(&pollable, IoEvents::IN, false, || {
            total_read += self.buf_rx.pop_slice(&mut buf[total_read..]);
            self.poll_tx.wake();
            (total_read >= vmin)
                .then_some(total_read)
                .ok_or(AxError::WouldBlock)
        }))
    }
}