1 files changed, 46 insertions, 0 deletions
diff --git a/third_party/rust/futures-0.1.29/src/sink/flush.rs b/third_party/rust/futures-0.1.29/src/sink/flush.rs
new file mode 100644
index 0000000000..f66811e03d
--- /dev/null
+++ b/third_party/rust/futures-0.1.29/src/sink/flush.rs
@@ -0,0 +1,46 @@
+use {Poll, Async, Future};
+use sink::Sink;
+
+/// Future for the `Sink::flush` combinator, which polls the sink until all data
+/// has been flushed.
+#[derive(Debug)]
+#[must_use = "futures do nothing unless polled"]
+pub struct Flush<S> {
+    sink: Option<S>,
+}
+
+pub fn new<S: Sink>(sink: S) -> Flush<S> {
+    Flush { sink: Some(sink) }
+}
+
+impl<S: Sink> Flush<S> {
+    /// Get a shared reference to the inner sink.
+    pub fn get_ref(&self) -> &S {
+        self.sink.as_ref().expect("Attempted `Flush::get_ref` after the flush completed")
+    }
+
+    /// Get a mutable reference to the inner sink.
+    pub fn get_mut(&mut self) -> &mut S {
+        self.sink.as_mut().expect("Attempted `Flush::get_mut` after the flush completed")
+    }
+
+    /// Consume the `Flush` and return the inner sink.
+    pub fn into_inner(self) -> S {
+        self.sink.expect("Attempted `Flush::into_inner` after the flush completed")
+    }
+}
+
+impl<S: Sink> Future for Flush<S> {
+    type Item = S;
+    type Error = S::SinkError;
+
+    fn poll(&mut self) -> Poll<S, S::SinkError> {
+        let mut sink = self.sink.take().expect("Attempted to poll Flush after it completed");
+        if sink.poll_complete()?.is_ready() {
+            Ok(Async::Ready(sink))
+        } else {
+            self.sink = Some(sink);
+            Ok(Async::NotReady)
+        }
+    }
+}