Add upgrade::map_with_addr (#331)

* Add upgrade::map_with_addr

* Some help for inferrence

core/src/upgrade/map_addr.rs

@@ -0,0 +1,80 @@
+// Copyright 2018 Parity Technologies (UK) Ltd.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+use std::io::Error as IoError;
+use futures::{future, prelude::*};
+use tokio_io::{AsyncRead, AsyncWrite};
+use upgrade::{ConnectionUpgrade, Endpoint};
+use Multiaddr;
+
+/// Applies a closure on the output of a connection upgrade.
+#[inline]
+pub fn map_with_addr<U, F, I, O>(upgrade: U, map: F) -> MapAddr<U, F>
+    where F: FnOnce(I, &Multiaddr) -> O
+{
+    MapAddr { upgrade, map }
+}
+
+/// Application of a closure on the output of a connection upgrade.
+#[derive(Debug, Copy, Clone)]
+pub struct MapAddr<U, F> {
+    upgrade: U,
+    map: F,
+}
+
+impl<C, U, F, O, Maf> ConnectionUpgrade<C, Maf> for MapAddr<U, F>
+where
+    U: ConnectionUpgrade<C, Maf>,
+    U::Future: 'static,     // TODO: 'static :(
+    U::MultiaddrFuture: Future<Item = Multiaddr, Error = IoError> + 'static,    // TODO: 'static :(
+    U::Output: 'static,     // TODO: 'static :(
+    C: AsyncRead + AsyncWrite,
+    F: FnOnce(U::Output, &Multiaddr) -> O + 'static,     // TODO: 'static :(
+{
+    type NamesIter = U::NamesIter;
+    type UpgradeIdentifier = U::UpgradeIdentifier;
+
+    fn protocol_names(&self) -> Self::NamesIter {
+        self.upgrade.protocol_names()
+    }
+
+    type Output = O;
+    type MultiaddrFuture = future::FutureResult<Multiaddr, IoError>;
+    type Future = Box<Future<Item = (O, Self::MultiaddrFuture), Error = IoError>>;
+
+    fn upgrade(
+        self,
+        socket: C,
+        id: Self::UpgradeIdentifier,
+        ty: Endpoint,
+        remote_addr: Maf,
+    ) -> Self::Future {
+        let map = self.map;
+        let fut = self.upgrade
+            .upgrade(socket, id, ty, remote_addr)
+            .and_then(|(out, addr)| {
+                addr.map(move |addr| {
+                    let out = map(out, &addr);
+                    (out, future::ok(addr))
+                })
+            });
+        Box::new(fut) as Box<_>
+    }
+}

core/src/upgrade/mod.rs

@@ -22,6 +22,7 @@ pub mod apply;
 pub mod choice;
 pub mod denied;
 pub mod map;
+pub mod map_addr;
 pub mod plaintext;
 pub mod toggleable;
 pub mod traits;
@@ -30,6 +31,7 @@ pub use self::apply::apply;
 pub use self::choice::{or, OrUpgrade};
 pub use self::denied::DeniedConnectionUpgrade;
 pub use self::map::map;
+pub use self::map_addr::map_with_addr;
 pub use self::plaintext::PlainTextConfig;
 pub use self::toggleable::toggleable;
 pub use self::traits::{ConnectionUpgrade, Endpoint};