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|
use futures::future::Future as _;
use futures::stream::Stream as _;
use snafu::{OptionExt as _, ResultExt as _};
use std::io::Write as _;
#[derive(Debug, snafu::Snafu)]
pub enum Error {
#[snafu(display("invalid command index: {}", idx))]
InvalidCommandIndex { idx: usize },
#[snafu(display("error during read: {}", source))]
Read { source: crate::readline::Error },
#[snafu(display("error during eval: {}", source))]
Eval { source: crate::eval::Error },
#[snafu(display("error during print: {}", source))]
Print { source: std::io::Error },
#[snafu(display("eof"))]
EOF,
}
pub type Result<T> = std::result::Result<T, Error>;
pub struct State {
idx: usize,
readline: Option<crate::readline::Readline>,
commands: std::collections::HashMap<usize, Command>,
}
impl State {
pub fn new() -> Result<Self> {
Ok(Self {
idx: 0,
readline: Some(Self::read()?),
commands: std::collections::HashMap::new(),
})
}
fn read() -> Result<crate::readline::Readline> {
crate::readline::readline("$ ", true).context(Read)
}
fn eval(
&mut self,
idx: usize,
line: &str,
) -> std::result::Result<(), Error> {
if self.commands.contains_key(&idx) {
return Err(Error::InvalidCommandIndex { idx });
}
let eval = crate::eval::eval(line).context(Eval);
match eval {
Ok(eval) => {
self.commands.insert(idx, Command::new(eval));
}
Err(e) => return Err(e),
}
Ok(())
}
fn command_start(
&mut self,
idx: usize,
cmd: &str,
args: &[String],
) -> Result<()> {
let command = self
.commands
.get_mut(&idx)
.context(InvalidCommandIndex { idx })?;
let cmd = cmd.to_string();
let args = args.to_vec();
eprint!("running '{} {:?}'\r\n", cmd, args);
command.cmd = Some(cmd);
command.args = Some(args);
Ok(())
}
fn command_output(&mut self, idx: usize, output: &[u8]) -> Result<()> {
let command = self
.commands
.get_mut(&idx)
.context(InvalidCommandIndex { idx })?;
command.output.append(&mut output.to_vec());
let stdout = std::io::stdout();
let mut stdout = stdout.lock();
stdout.write(output).context(Print)?;
stdout.flush().context(Print)?;
Ok(())
}
fn command_exit(
&mut self,
idx: usize,
status: std::process::ExitStatus,
) -> Result<()> {
let command = self
.commands
.get_mut(&idx)
.context(InvalidCommandIndex { idx })?;
command.status = Some(status);
eprint!("command exited: {}\r\n", status);
Ok(())
}
fn poll_with_errors(&mut self) -> futures::Poll<(), Error> {
loop {
let mut did_work = false;
if self.readline.is_none() && self.commands.is_empty() {
self.idx += 1;
self.readline = Some(Self::read()?)
}
if let Some(mut r) = self.readline.take() {
match r.poll() {
Ok(futures::Async::Ready(line)) => {
// overlapping RawScreen lifespans don't work properly
// - if readline creates a RawScreen, then eval
// creates a separate one, then readline drops it, the
// screen will go back to cooked even though a
// RawScreen instance is still live.
drop(r);
match self.eval(self.idx, &line) {
Ok(())
| Err(Error::Eval {
source:
crate::eval::Error::Parser {
source:
crate::parser::Error::CommandRequired,
..
},
}) => {}
Err(e) => return Err(e),
}
did_work = true;
}
Ok(futures::Async::NotReady) => {
self.readline.replace(r);
}
Err(crate::readline::Error::EOF) => {
return Err(Error::EOF)
}
Err(e) => return Err(e).context(Read),
}
}
for idx in self.commands.keys().cloned().collect::<Vec<usize>>() {
match self
.commands
.get_mut(&idx)
.unwrap()
.future
.poll()
.context(Eval)?
{
futures::Async::Ready(Some(event)) => match event {
crate::eval::CommandEvent::CommandStart(
cmd,
args,
) => {
self.command_start(idx, &cmd, &args)?;
did_work = true;
}
crate::eval::CommandEvent::Output(out) => {
self.command_output(idx, &out)?;
did_work = true;
}
crate::eval::CommandEvent::CommandExit(status) => {
self.command_exit(idx, status)?;
did_work = true;
}
},
futures::Async::Ready(None) => {
self.commands
.remove(&idx)
.context(InvalidCommandIndex { idx })?;
did_work = true;
}
futures::Async::NotReady => {}
}
}
if !did_work {
return Ok(futures::Async::NotReady);
}
}
}
}
impl futures::future::Future for State {
type Item = ();
type Error = ();
fn poll(&mut self) -> futures::Poll<Self::Item, Self::Error> {
loop {
match self.poll_with_errors() {
Ok(a) => return Ok(a),
Err(Error::EOF) => return Ok(futures::Async::Ready(())),
Err(e) => {
eprint!("error polling state: {}\r\n", e);
}
}
}
}
}
struct Command {
future: crate::eval::Eval,
cmd: Option<String>,
args: Option<Vec<String>>,
output: Vec<u8>,
status: Option<std::process::ExitStatus>,
}
impl Command {
fn new(future: crate::eval::Eval) -> Self {
Self {
future,
cmd: None,
args: None,
output: vec![],
status: None,
}
}
}
|
