rust: foundation (inventory, platform, scan, export, textutil, config)

rust/src/cancel.rs

@@ -0,0 +1,41 @@
+//! A clonable cancellation token, the equivalent of a Go context's Done.
+
+use crossbeam_channel::{Receiver, Sender};
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex};
+
+#[derive(Clone)]
+pub struct Cancel(Arc<Inner>);
+
+struct Inner {
+    flag: AtomicBool,
+    tx: Mutex<Option<Sender<()>>>,
+    rx: Receiver<()>,
+}
+
+impl Default for Cancel {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Cancel {
+    pub fn new() -> Cancel {
+        let (tx, rx) = crossbeam_channel::bounded(0);
+        Cancel(Arc::new(Inner { flag: AtomicBool::new(false), tx: Mutex::new(Some(tx)), rx }))
+    }
+
+    pub fn cancel(&self) {
+        self.0.flag.store(true, Ordering::Relaxed);
+        self.0.tx.lock().unwrap().take();
+    }
+
+    pub fn is_cancelled(&self) -> bool {
+        self.0.flag.load(Ordering::Relaxed)
+    }
+
+    /// Becomes ready (disconnected) once cancelled; for use in select.
+    pub fn done(&self) -> &Receiver<()> {
+        &self.0.rx
+    }
+}