Event receiving/committing infrastructure

vfs/src/lib.rs

@@ -26,7 +26,7 @@ pub trait VfsBackend: sealed::Sealed {
     fn read_dir(&mut self, path: &Path) -> io::Result<ReadDir>;
     fn metadata(&mut self, path: &Path) -> io::Result<Metadata>;
 
-    fn event_receiver(&mut self) -> crossbeam_channel::Receiver<VfsEvent>;
+    fn event_receiver(&self) -> crossbeam_channel::Receiver<VfsEvent>;
     fn watch(&mut self, path: &Path) -> io::Result<()>;
     fn unwatch(&mut self, path: &Path) -> io::Result<()>;
 }
@@ -101,6 +101,15 @@ impl VfsLock {
         let path = path.as_ref();
         self.backend.read_dir(path)
     }
+
+    pub fn event_receiver(&self) -> crossbeam_channel::Receiver<VfsEvent> {
+        self.backend.event_receiver()
+    }
+
+    pub fn commit_event(&mut self, _event: &VfsEvent) -> io::Result<()> {
+        // Because we hold no state, there's no cache to update here.
+        Ok(())
+    }
 }
 
 /// A virtual filesystem with a configurable backend.
@@ -156,4 +165,14 @@ impl Vfs {
         let path = path.as_ref();
         self.inner.lock().unwrap().read_dir(path)
     }
+
+    /// Retrieve a handle to the event receiver for this `Vfs`.
+    pub fn event_receiver(&self) -> crossbeam_channel::Receiver<VfsEvent> {
+        self.inner.lock().unwrap().event_receiver()
+    }
+
+    /// Commit an event to this `Vfs`.
+    pub fn commit_event(&self, event: &VfsEvent) -> io::Result<()> {
+        self.inner.lock().unwrap().commit_event(event)
+    }
 }

vfs/src/noop_backend.rs

@@ -42,7 +42,7 @@ impl VfsBackend for NoopBackend {
         ))
     }
 
-    fn event_receiver(&mut self) -> crossbeam_channel::Receiver<VfsEvent> {
+    fn event_receiver(&self) -> crossbeam_channel::Receiver<VfsEvent> {
         crossbeam_channel::never()
     }
 

vfs/src/std_backend.rs

@@ -82,7 +82,7 @@ impl VfsBackend for StdBackend {
         })
     }
 
-    fn event_receiver(&mut self) -> crossbeam_channel::Receiver<VfsEvent> {
+    fn event_receiver(&self) -> crossbeam_channel::Receiver<VfsEvent> {
         self.watcher_receiver.clone()
     }