use core::ops::Deref; use super::command_parser::{Command, Error as ParserError}; const MAX_LINE_LEN: usize = 64; struct LineReader { buf: [u8; MAX_LINE_LEN], pos: usize, } impl LineReader { pub fn new() -> Self { LineReader { buf: [0; MAX_LINE_LEN], pos: 0, } } pub fn feed(&mut self, c: u8) -> Option { if c == 13 || c == 10 { // Enter if self.pos > 0 { let len = self.pos; self.pos = 0; Some(LineResult { buf: self.buf.clone(), len, }) } else { None } } else if self.pos < self.buf.len() { // Add input self.buf[self.pos] = c; self.pos += 1; None } else { // Buffer is full, ignore None } } } pub struct LineResult { buf: [u8; MAX_LINE_LEN], len: usize, } impl Deref for LineResult { type Target = [u8]; fn deref(&self) -> &Self::Target { &self.buf[..self.len] } } pub enum SessionOutput { Nothing, Command(Command), Error(ParserError), } impl From> for SessionOutput { fn from(input: Result) -> Self { input.map(SessionOutput::Command) .unwrap_or_else(SessionOutput::Error) } } pub const CHANNELS: usize = 2; pub struct Session { reader: LineReader, reporting: bool, report_pending: [bool; CHANNELS], } impl Default for Session { fn default() -> Self { Session::new() } } impl Session { pub fn new() -> Self { Session { reader: LineReader::new(), reporting: false, report_pending: [false; CHANNELS], } } pub fn reset(&mut self) { self.reader = LineReader::new(); self.reporting = false; self.report_pending = [false; CHANNELS]; } pub fn is_dirty(&self) -> bool { self.reader.pos > 0 } pub fn reporting(&self) -> bool { self.reporting } pub fn set_report_pending(&mut self, channel: usize) { if self.reporting { self.report_pending[channel] = true; } } pub fn is_report_pending(&self) -> Option { if ! self.reporting { None } else { self.report_pending.iter() .enumerate() .fold(None, |result, (channel, report_pending)| { result.or_else(|| { if *report_pending { Some(channel) } else { None } }) }) } } pub fn mark_report_sent(&mut self, channel: usize) { self.report_pending[channel] = false; } pub fn feed(&mut self, buf: &[u8]) -> (usize, SessionOutput) { let mut buf_bytes = 0; for (i, b) in buf.iter().enumerate() { buf_bytes = i + 1; let line = self.reader.feed(*b); match line { Some(line) => { let command = Command::parse(&line); match command { Ok(Command::Reporting(reporting)) => { self.reporting = reporting; } _ => {} } return (buf_bytes, command.into()); } None => {} } } (buf_bytes, SessionOutput::Nothing) } }