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|
mod table;
mod definitions;
pub use definitions::{Action, State, unpack};
use table::{EXIT_ACTIONS, ENTRY_ACTIONS, STATE_CHANGE};
impl State {
/// Get exit action for this state
#[inline(always)]
pub fn exit_action(&self) -> Action {
unsafe {
*EXIT_ACTIONS.get_unchecked(*self as usize)
}
}
/// Get entry action for this state
#[inline(always)]
pub fn entry_action(&self) -> Action {
unsafe {
*ENTRY_ACTIONS.get_unchecked(*self as usize)
}
}
}
const MAX_INTERMEDIATES: usize = 2;
const MAX_PARAMS: usize = 16;
/// ANSI VTE Parser
///
/// As described in http://vt100.net/emu/dec_ansi_parser
///
/// TODO: utf8 support
pub struct StateMachine {
state: State,
intermediates: [u8; MAX_INTERMEDIATES],
intermediate_idx: usize,
params: [i64; MAX_PARAMS],
num_params: usize,
ignoring: bool
}
impl StateMachine {
pub fn new() -> StateMachine {
StateMachine {
state: State::Ground,
intermediates: [0u8; MAX_INTERMEDIATES],
intermediate_idx: 0,
params: [0i64; MAX_PARAMS],
num_params: 0,
ignoring: false,
}
}
pub fn params(&self) -> &[i64] {
&self.params[..self.num_params]
}
pub fn intermediates(&self) -> &[u8] {
&self.intermediates[..self.intermediate_idx]
}
pub fn advance<P: Parser>(&mut self, parser: &mut P, byte: u8) {
// Handle state changes in the anywhere state before evaluating changes
// for current state.
let mut change = STATE_CHANGE[State::Anywhere as usize][byte as usize];
if change == 0 {
change = STATE_CHANGE[self.state as usize][byte as usize];
}
// Unpack into a state and action
let (state, action) = unpack(change);
self.perform_state_change(parser, state, action, byte);
}
fn perform_state_change<P>(&mut self, parser: &mut P, state: State, action: Action, byte: u8)
where P: Parser
{
macro_rules! maybe_action {
($action:expr, $arg:expr) => {
match $action {
Action::None | Action::Unused__ => (),
action => {
self.perform_action(parser, action, $arg);
},
}
}
}
match state {
State::Anywhere | State::Unused__ => {
// Just run the action
self.perform_action(parser, action, byte);
},
state => {
// Exit action for previous state
let exit_action = self.state.exit_action();
maybe_action!(exit_action, 0);
// Transition action
maybe_action!(action, byte);
// Entry action for new state
maybe_action!(state.entry_action(), 0);
// Assume the new state
self.state = state;
}
}
}
fn perform_action<P: Parser>(&mut self, parser: &mut P, action: Action, byte: u8) {
match action {
Action::Print => parser.print(self, byte as char),
Action::Execute => parser.execute(self, byte),
Action::Hook => parser.hook(self, byte),
Action::Put => parser.put(self, byte),
Action::OscStart => parser.osc_start(self, byte),
Action::OscPut => parser.osc_put(self, byte),
Action::OscEnd => parser.osc_end(self, byte),
Action::Unhook => parser.unhook(self, byte),
Action::CsiDispatch => parser.csi_dispatch(self, byte as char),
Action::EscDispatch => parser.esc_dispatch(self, byte),
Action::Ignore | Action::None | Action::Unused__=> (),
Action::Collect => {
if self.intermediate_idx == MAX_INTERMEDIATES {
self.ignoring = true;
} else {
self.intermediates[self.intermediate_idx] = byte;
self.intermediate_idx += 1;
}
},
Action::Param => {
// if byte == ';'
if byte == 0x3b {
// end of param; advance to next
self.num_params += 1;
let idx = self.num_params - 1; // borrowck
self.params[idx] = 0;
} else {
if self.num_params == 0 {
self.num_params = 1;
self.params[0] = 0;
}
let idx = self.num_params - 1;
self.params[idx] *= 10;
self.params[idx] += (byte - ('0' as u8)) as i64;
}
},
Action::Clear => {
self.intermediate_idx = 0;
self.num_params = 0;
self.ignoring = false;
}
}
}
}
pub trait Parser {
fn print(&mut self, &StateMachine, c: char);
fn execute(&mut self, &StateMachine, byte: u8);
fn hook(&mut self, &StateMachine, byte: u8);
fn put(&mut self, &StateMachine, byte: u8);
fn osc_start(&mut self, &StateMachine, byte: u8);
fn osc_put(&mut self, &StateMachine, byte: u8);
fn osc_end(&mut self, &StateMachine, byte: u8);
fn unhook(&mut self, &StateMachine, byte: u8);
fn csi_dispatch(&mut self, &StateMachine, c: char);
fn esc_dispatch(&mut self, &StateMachine, byte: u8);
}
|
