1 files changed, 88 insertions, 0 deletions
diff --git a/src/async_stdin.rs b/src/async_stdin.rs
new file mode 100644
index 0000000..e3b0ead
--- /dev/null
+++ b/src/async_stdin.rs
@@ -0,0 +1,88 @@
+struct EventedStdin;
+
+const STDIN: i32 = 0;
+
+impl std::io::Read for EventedStdin {
+    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        let stdin = std::io::stdin();
+        let mut stdin = stdin.lock();
+        stdin.read(buf)
+    }
+}
+
+impl mio::Evented for EventedStdin {
+    fn register(
+        &self,
+        poll: &mio::Poll,
+        token: mio::Token,
+        interest: mio::Ready,
+        opts: mio::PollOpt,
+    ) -> std::io::Result<()> {
+        let fd = STDIN as std::os::unix::io::RawFd;
+        let eventedfd = mio::unix::EventedFd(&fd);
+        eventedfd.register(poll, token, interest, opts)
+    }
+
+    fn reregister(
+        &self,
+        poll: &mio::Poll,
+        token: mio::Token,
+        interest: mio::Ready,
+        opts: mio::PollOpt,
+    ) -> std::io::Result<()> {
+        let fd = STDIN as std::os::unix::io::RawFd;
+        let eventedfd = mio::unix::EventedFd(&fd);
+        eventedfd.reregister(poll, token, interest, opts)
+    }
+
+    fn deregister(&self, poll: &mio::Poll) -> std::io::Result<()> {
+        let fd = STDIN as std::os::unix::io::RawFd;
+        let eventedfd = mio::unix::EventedFd(&fd);
+        eventedfd.deregister(poll)
+    }
+}
+
+pub struct Stdin {
+    input: tokio::reactor::PollEvented2<EventedStdin>,
+}
+
+impl Stdin {
+    pub fn new() -> Self {
+        Self {
+            input: tokio::reactor::PollEvented2::new(EventedStdin),
+        }
+    }
+}
+
+impl std::io::Read for Stdin {
+    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        self.input.read(buf)
+    }
+}
+
+impl tokio::io::AsyncRead for Stdin {
+    fn poll_read(
+        &mut self,
+        buf: &mut [u8],
+    ) -> std::result::Result<futures::Async<usize>, tokio::io::Error> {
+        // XXX this is why i had to do the EventedFd thing - poll_read on its
+        // own will block reading from stdin, so i need a way to explicitly
+        // check readiness before doing the read
+        let ready = mio::Ready::readable();
+        match self.input.poll_read_ready(ready)? {
+            futures::Async::Ready(_) => {
+                let res = self.input.poll_read(buf);
+
+                // XXX i'm pretty sure this is wrong (if the single poll_read
+                // call didn't return all waiting data, clearing read ready
+                // state means that we won't get the rest until some more data
+                // beyond that appears), but i don't know that there's a way
+                // to do it correctly given that poll_read blocks
+                self.input.clear_read_ready(ready)?;
+
+                res
+            }
+            futures::Async::NotReady => Ok(futures::Async::NotReady),
+        }
+    }
+}