internal: Load VFS config changes in parallel

crates/vfs/src/loader.rs

@@ -43,6 +43,13 @@ pub struct Config {
     pub watch: Vec<usize>,
 }
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum LoadingProgress {
+    Started,
+    Progress(usize),
+    Finished,
+}
+
 /// Message about an action taken by a [`Handle`].
 pub enum Message {
     /// Indicate a gradual progress.
@@ -52,7 +59,7 @@ pub enum Message {
         /// The total files to be loaded.
         n_total: usize,
         /// The files that have been loaded successfully.
-        n_done: Option<usize>,
+        n_done: LoadingProgress,
         /// The dir being loaded, `None` if its for a file.
         dir: Option<AbsPathBuf>,
         /// The [`Config`] version.
@@ -65,7 +72,7 @@ pub enum Message {
 }
 
 /// Type that will receive [`Messages`](Message) from a [`Handle`].
-pub type Sender = Box<dyn Fn(Message) + Send>;
+pub type Sender = Box<dyn Fn(Message) + Send + Sync>;
 
 /// Interface for reading and watching files.
 pub trait Handle: fmt::Debug {