chaser_oxide/
async_process.rs

1//! Internal module providing an async child process abstraction for `async-std` or `tokio`.
2
3use std::ffi::OsStr;
4use std::pin::Pin;
5pub use std::process::{ExitStatus, Stdio};
6use std::task::{Context, Poll};
7
8cfg_if::cfg_if! {
9    if #[cfg(feature = "async-std-runtime")] {
10        use ::async_std::process;
11    } else if #[cfg(feature = "tokio-runtime")] {
12        use ::tokio::process;
13    }
14}
15
16#[derive(Debug)]
17pub struct Command {
18    inner: process::Command,
19}
20
21impl Command {
22    pub fn new<S: AsRef<OsStr>>(program: S) -> Self {
23        let mut inner = process::Command::new(program);
24        // Since the kill and/or wait methods are async, we can't call
25        // explicitely in the Drop implementation. We MUST rely on the
26        // runtime implemetation which is already designed to deal with
27        // this case where the user didn't explicitely kill the child
28        // process before dropping the handle.
29        inner.kill_on_drop(true);
30        Self { inner }
31    }
32
33    pub fn arg<S: AsRef<OsStr>>(&mut self, arg: S) -> &mut Self {
34        self.inner.arg(arg);
35        self
36    }
37
38    pub fn args<I, S>(&mut self, args: I) -> &mut Self
39    where
40        I: IntoIterator<Item = S>,
41        S: AsRef<OsStr>,
42    {
43        self.inner.args(args);
44        self
45    }
46
47    pub fn envs<I, K, V>(&mut self, vars: I) -> &mut Self
48    where
49        I: IntoIterator<Item = (K, V)>,
50        K: AsRef<OsStr>,
51        V: AsRef<OsStr>,
52    {
53        self.inner.envs(vars);
54        self
55    }
56
57    pub fn stderr<T: Into<Stdio>>(&mut self, cfg: T) -> &mut Self {
58        self.inner.stderr(cfg);
59        self
60    }
61
62    pub fn spawn(&mut self) -> std::io::Result<Child> {
63        let inner = self.inner.spawn()?;
64        Ok(Child::new(inner))
65    }
66}
67
68#[derive(Debug)]
69pub struct Child {
70    pub stderr: Option<ChildStderr>,
71    pub inner: process::Child,
72}
73
74/// Wrapper for an async child process.
75///
76/// The inner implementation depends on the selected async runtime (features `async-std-runtime`
77/// or `tokio-runtime`).
78impl Child {
79    fn new(mut inner: process::Child) -> Self {
80        let stderr = inner.stderr.take();
81        Self {
82            inner,
83            stderr: stderr.map(|inner| ChildStderr { inner }),
84        }
85    }
86
87    /// Kill the child process synchronously and asynchronously wait for the
88    /// child to exit
89    pub async fn kill(&mut self) -> std::io::Result<()> {
90        cfg_if::cfg_if! {
91            if #[cfg(feature = "async-std-runtime")] {
92                self.inner.kill()?;
93                self.wait().await?;
94                Ok(())
95            } else if #[cfg(feature = "tokio-runtime")] {
96                // Tokio already waits internally
97                self.inner.kill().await
98            }
99        }
100    }
101
102    /// Asynchronously wait for the child process to exit
103    pub async fn wait(&mut self) -> std::io::Result<ExitStatus> {
104        cfg_if::cfg_if! {
105            if #[cfg(feature = "async-std-runtime")] {
106                self.inner.status().await
107            } else if #[cfg(feature = "tokio-runtime")] {
108                self.inner.wait().await
109            }
110        }
111    }
112
113    /// If the child process has exited, get its status
114    pub fn try_wait(&mut self) -> std::io::Result<Option<ExitStatus>> {
115        cfg_if::cfg_if! {
116            if #[cfg(feature = "async-std-runtime")] {
117                self.inner.try_status()
118            } else if #[cfg(feature = "tokio-runtime")] {
119                self.inner.try_wait()
120            }
121        }
122    }
123
124    /// Return a mutable reference to the inner process
125    ///
126    /// `stderr` may not be available.
127    pub fn as_mut_inner(&mut self) -> &mut process::Child {
128        &mut self.inner
129    }
130
131    /// Return the inner process
132    pub fn into_inner(self) -> process::Child {
133        let mut inner = self.inner;
134        inner.stderr = self.stderr.map(ChildStderr::into_inner);
135        inner
136    }
137}
138
139#[derive(Debug)]
140pub struct ChildStderr {
141    pub inner: process::ChildStderr,
142}
143
144impl ChildStderr {
145    pub fn into_inner(self) -> process::ChildStderr {
146        self.inner
147    }
148}
149
150impl futures::AsyncRead for ChildStderr {
151    fn poll_read(
152        mut self: Pin<&mut Self>,
153        cx: &mut Context<'_>,
154        buf: &mut [u8],
155    ) -> Poll<std::io::Result<usize>> {
156        cfg_if::cfg_if! {
157            if #[cfg(feature = "async-std-runtime")] {
158                Pin::new(&mut self.inner).poll_read(cx, buf)
159            } else if #[cfg(feature = "tokio-runtime")] {
160                let mut buf = tokio::io::ReadBuf::new(buf);
161                futures::ready!(tokio::io::AsyncRead::poll_read(
162                    Pin::new(&mut self.inner),
163                    cx,
164                    &mut buf
165                ))?;
166                Poll::Ready(Ok(buf.filled().len()))
167            }
168        }
169    }
170}
chaser_oxide/async_process.rs

chaser_oxide/
async_process.rs
