lib(tokio): ExclusiveExecutor

1 files changed, 34 insertions, 0 deletions

diff --git a/qml_plugin/src/lib.rs b/qml_plugin/src/lib.rs
index e4ad346..f9f095e 100644
--- a/qml_plugin/src/lib.rs
+++ b/qml_plugin/src/lib.rs
@@ -1,5 +1,7 @@
 use std::sync::LazyLock;
 
+use tokio::task;
+
 static RUNTIME: LazyLock<tokio::runtime::Runtime> = LazyLock::new(
     || {
         tokio::runtime::Builder::new_multi_thread()
@@ -9,5 +11,37 @@ static RUNTIME: LazyLock<tokio::runtime::Runtime> = LazyLock::new(
     },
 );
 
+/// for example duckduckgo we wanna cancel first request if user types new query
+/// using this guarentee that only one request is running at a time or at least
+/// the first one is being aborted
+#[derive(Default)]
+pub struct ExclusiveExecutor {
+    handle: Option<task::JoinHandle<()>>,
+}
+
+impl ExclusiveExecutor {
+    pub fn new() -> Self {
+        Self {
+            handle: None,
+        }
+    }
+
+    #[track_caller]
+    pub fn spawn<F>(&mut self, future: F)
+    where
+        F: Future<Output = ()> + Send + 'static,
+        F::Output: Send + 'static,
+    {
+        if let Some(handle) = self
+            .handle
+            .take()
+        {
+            handle.abort();
+        }
+
+        self.handle = Some(RUNTIME.spawn(future))
+    }
+}
+
 mod launcher;
 mod web;