1 files changed, 39 insertions, 0 deletions
diff --git a/third_party/rust/tokio-fs/src/file/metadata.rs b/third_party/rust/tokio-fs/src/file/metadata.rs
new file mode 100644
index 0000000000..b55ca103c1
--- /dev/null
+++ b/third_party/rust/tokio-fs/src/file/metadata.rs
@@ -0,0 +1,39 @@
+use super::File;
+
+use futures::{Future, Poll};
+
+use std::fs::File as StdFile;
+use std::fs::Metadata;
+use std::io;
+
+const POLL_AFTER_RESOLVE: &str = "Cannot poll MetadataFuture after it resolves";
+
+/// Future returned by `File::metadata` and resolves to a `(Metadata, File)` instance.
+#[derive(Debug)]
+pub struct MetadataFuture {
+    file: Option<File>,
+}
+
+impl MetadataFuture {
+    pub(crate) fn new(file: File) -> Self {
+        MetadataFuture { file: Some(file) }
+    }
+
+    fn std(&mut self) -> &mut StdFile {
+        self.file.as_mut().expect(POLL_AFTER_RESOLVE).std()
+    }
+}
+
+impl Future for MetadataFuture {
+    type Item = (File, Metadata);
+    type Error = io::Error;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        let metadata = try_ready!(::blocking_io(|| {
+            StdFile::metadata(self.std())
+        }));
+
+        let file = self.file.take().expect(POLL_AFTER_RESOLVE);
+        Ok((file, metadata).into())
+    }
+}