detect_targets/
desired_targets.rs

1use crate::detect_targets;
2
3use std::sync::Arc;
4
5use tokio::sync::SetOnce;
6
7#[derive(Debug)]
8enum DesiredTargetsInner {
9    AutoDetect(Arc<SetOnce<Vec<String>>>),
10    Initialized(Vec<String>),
11}
12
13#[derive(Debug)]
14pub struct DesiredTargets(DesiredTargetsInner);
15
16impl DesiredTargets {
17    fn initialized(targets: Vec<String>) -> Self {
18        Self(DesiredTargetsInner::Initialized(targets))
19    }
20
21    fn auto_detect() -> Self {
22        let arc = Arc::new(SetOnce::new());
23
24        let set_once = arc.clone();
25        tokio::spawn(async move {
26            set_once.set(detect_targets().await).unwrap();
27        });
28
29        Self(DesiredTargetsInner::AutoDetect(arc))
30    }
31
32    pub async fn get(&self) -> &[String] {
33        use DesiredTargetsInner::*;
34
35        match &self.0 {
36            Initialized(targets) => targets,
37            AutoDetect(set_once) => set_once.wait().await,
38        }
39    }
40
41    /// If `DesiredTargets` is provided with a list of desired targets instead
42    /// of detecting the targets, then this function would return `Some`.
43    pub fn get_initialized(&self) -> Option<&[String]> {
44        use DesiredTargetsInner::*;
45
46        match &self.0 {
47            Initialized(targets) => Some(targets),
48            AutoDetect(..) => None,
49        }
50    }
51}
52
53/// If opts_targets is `Some`, then it will be used.
54/// Otherwise, call `detect_targets` using `tokio::spawn` to detect targets.
55///
56/// Since `detect_targets` internally spawns a process and wait for it,
57/// it's pretty costy, it is recommended to run this fn ASAP and
58/// reuse the result.
59pub fn get_desired_targets(opts_targets: Option<Vec<String>>) -> DesiredTargets {
60    if let Some(targets) = opts_targets {
61        DesiredTargets::initialized(targets)
62    } else {
63        DesiredTargets::auto_detect()
64    }
65}
detect_targets/desired_targets.rs

detect_targets/
desired_targets.rs
