Update root crate to use futures-0.3. (#1315)

Mostly mechanical. Creating a `CommonTransport` yields an
`io::Result<_>` now since creating the `DnsConfig` may fail with an
`io::Error` when creating the `ThreadPool`.

The `DnsConfig` `Transport` impl had to be changed slightly:

(a) PR [[1311]] requires some `Send` bounds.
(b) The async block had to be changed to work around lifetime inference
issues which resulted in an "one type is more general than the other"
error.

[1311]: https://github.com/libp2p/rust-libp2p/pull/1311

Cargo.toml

@@ -15,7 +15,7 @@ secp256k1 = ["libp2p-core/secp256k1", "libp2p-secio/secp256k1"]
 
 [dependencies]
 bytes = "0.4"
-futures = "0.1"
+futures = "0.3.1"
 multiaddr = { package = "parity-multiaddr", version = "0.5.1", path = "misc/multiaddr" }
 multihash = { package = "parity-multihash", version = "0.1.4", path = "misc/multihash" }
 lazy_static = "1.2"
@@ -34,10 +34,7 @@ libp2p-wasm-ext = { version = "0.6.0", path = "transports/wasm-ext" }
 libp2p-yamux = { version = "0.13.0", path = "muxers/yamux" }
 parking_lot = "0.9.0"
 smallvec = "1.0"
-tokio-codec = "0.1"
-tokio-executor = "0.1"
-tokio-io = "0.1"
-wasm-timer = "0.1"
+wasm-timer = "0.2.4"
 
 [target.'cfg(not(any(target_os = "emscripten", target_os = "unknown")))'.dependencies]
 libp2p-deflate = { version = "0.5.0", path = "protocols/deflate" }

src/bandwidth.rs

@@ -19,11 +19,11 @@
 // DEALINGS IN THE SOFTWARE.
 
 use crate::{Multiaddr, core::{Transport, transport::{ListenerEvent, TransportError}}};
-use futures::{prelude::*, try_ready};
+use futures::{prelude::*, io::{IoSlice, IoSliceMut}, ready};
 use lazy_static::lazy_static;
 use parking_lot::Mutex;
 use smallvec::{smallvec, SmallVec};
-use std::{cmp, io, io::Read, io::Write, sync::Arc, time::Duration};
+use std::{cmp, io, pin::Pin, sync::Arc, task::{Context, Poll}, time::Duration};
 use wasm_timer::Instant;
 
 /// Wraps around a `Transport` and logs the bandwidth that goes through all the opened connections.
@@ -35,7 +35,6 @@ pub struct BandwidthLogging<TInner> {
 
 impl<TInner> BandwidthLogging<TInner> {
     /// Creates a new `BandwidthLogging` around the transport.
-    #[inline]
     pub fn new(inner: TInner, period: Duration) -> (Self, Arc<BandwidthSinks>) {
         let mut period_seconds = cmp::min(period.as_secs(), 86400) as u32;
         if period.subsec_nanos() > 0 {
@@ -58,7 +57,10 @@ impl<TInner> BandwidthLogging<TInner> {
 
 impl<TInner> Transport for BandwidthLogging<TInner>
 where
-    TInner: Transport,
+    TInner: Transport + Unpin,
+    TInner::Dial: Unpin,
+    TInner::Listener: Unpin,
+    TInner::ListenerUpgrade: Unpin
 {
     type Output = BandwidthConnecLogging<TInner::Output>;
     type Error = TInner::Error;
@@ -90,22 +92,23 @@ pub struct BandwidthListener<TInner> {
 
 impl<TInner, TConn> Stream for BandwidthListener<TInner>
 where
-    TInner: Stream<Item = ListenerEvent<TConn>>,
+    TInner: TryStream<Ok = ListenerEvent<TConn>> + Unpin
 {
-    type Item = ListenerEvent<BandwidthFuture<TConn>>;
-    type Error = TInner::Error;
+    type Item = Result<ListenerEvent<BandwidthFuture<TConn>>, TInner::Error>;
 
-    fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
-        let event = match try_ready!(self.inner.poll()) {
-            Some(v) => v,
-            None => return Ok(Async::Ready(None))
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
+        let event =
+            if let Some(event) = ready!(self.inner.try_poll_next_unpin(cx)?) {
+                event
+            } else {
+                return Poll::Ready(None)
             };
 
         let event = event.map(|inner| {
             BandwidthFuture { inner, sinks: self.sinks.clone() }
         });
 
-        Ok(Async::Ready(Some(event)))
+        Poll::Ready(Some(Ok(event)))
     }
 }
 
@@ -116,18 +119,13 @@ pub struct BandwidthFuture<TInner> {
     sinks: Arc<BandwidthSinks>,
 }
 
-impl<TInner> Future for BandwidthFuture<TInner>
-    where TInner: Future,
-{
-    type Item = BandwidthConnecLogging<TInner::Item>;
-    type Error = TInner::Error;
+impl<TInner: TryFuture + Unpin> Future for BandwidthFuture<TInner> {
+    type Output = Result<BandwidthConnecLogging<TInner::Ok>, TInner::Error>;
 
-    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-        let inner = try_ready!(self.inner.poll());
-        Ok(Async::Ready(BandwidthConnecLogging {
-            inner,
-            sinks: self.sinks.clone(),
-        }))
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
+        let inner = ready!(self.inner.try_poll_unpin(cx)?);
+        let logged = BandwidthConnecLogging { inner, sinks: self.sinks.clone() };
+        Poll::Ready(Ok(logged))
     }
 }
 
@@ -139,13 +137,11 @@ pub struct BandwidthSinks {
 
 impl BandwidthSinks {
     /// Returns the average number of bytes that have been downloaded in the period.
-    #[inline]
     pub fn average_download_per_sec(&self) -> u64 {
         self.download.lock().get()
     }
 
     /// Returns the average number of bytes that have been uploaded in the period.
-    #[inline]
     pub fn average_upload_per_sec(&self) -> u64 {
         self.upload.lock().get()
     }
@@ -157,56 +153,43 @@ pub struct BandwidthConnecLogging<TInner> {
     sinks: Arc<BandwidthSinks>,
 }
 
-impl<TInner> Read for BandwidthConnecLogging<TInner>
-    where TInner: Read
-{
-    #[inline]
-    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        let num_bytes = self.inner.read(buf)?;
+impl<TInner: AsyncRead + Unpin> AsyncRead for BandwidthConnecLogging<TInner> {
+    fn poll_read(mut self: Pin<&mut Self>, cx: &mut Context, buf: &mut [u8]) -> Poll<io::Result<usize>> {
+        let num_bytes = ready!(Pin::new(&mut self.inner).poll_read(cx, buf))?;
         self.sinks.download.lock().inject(num_bytes);
-        Ok(num_bytes)
+        Poll::Ready(Ok(num_bytes))
+    }
+
+    fn poll_read_vectored(mut self: Pin<&mut Self>, cx: &mut Context, bufs: &mut [IoSliceMut]) -> Poll<io::Result<usize>> {
+        let num_bytes = ready!(Pin::new(&mut self.inner).poll_read_vectored(cx, bufs))?;
+        self.sinks.download.lock().inject(num_bytes);
+        Poll::Ready(Ok(num_bytes))
     }
 }
 
-impl<TInner> tokio_io::AsyncRead for BandwidthConnecLogging<TInner>
-    where TInner: tokio_io::AsyncRead
-{
-    unsafe fn prepare_uninitialized_buffer(&self, buf: &mut [u8]) -> bool {
-        self.inner.prepare_uninitialized_buffer(buf)
-    }
-
-    fn read_buf<B: bytes::BufMut>(&mut self, buf: &mut B) -> Poll<usize, io::Error> {
-        self.inner.read_buf(buf)
-    }
-}
-
-impl<TInner> Write for BandwidthConnecLogging<TInner>
-    where TInner: Write
-{
-    #[inline]
-    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        let num_bytes = self.inner.write(buf)?;
+impl<TInner: AsyncWrite + Unpin> AsyncWrite for BandwidthConnecLogging<TInner> {
+    fn poll_write(mut self: Pin<&mut Self>, cx: &mut Context, buf: &[u8]) -> Poll<io::Result<usize>> {
+        let num_bytes = ready!(Pin::new(&mut self.inner).poll_write(cx, buf))?;
         self.sinks.upload.lock().inject(num_bytes);
-        Ok(num_bytes)
+        Poll::Ready(Ok(num_bytes))
     }
 
-    #[inline]
-    fn flush(&mut self) -> io::Result<()> {
-        self.inner.flush()
+    fn poll_write_vectored(mut self: Pin<&mut Self>, cx: &mut Context, bufs: &[IoSlice]) -> Poll<io::Result<usize>> {
+        let num_bytes = ready!(Pin::new(&mut self.inner).poll_write_vectored(cx, bufs))?;
+        self.sinks.upload.lock().inject(num_bytes);
+        Poll::Ready(Ok(num_bytes))
     }
-}
 
-impl<TInner> tokio_io::AsyncWrite for BandwidthConnecLogging<TInner>
-    where TInner: tokio_io::AsyncWrite
-{
-    #[inline]
-    fn shutdown(&mut self) -> Poll<(), io::Error> {
-        self.inner.shutdown()
+    fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.inner).poll_flush(cx)
+    }
+
+    fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.inner).poll_close(cx)
     }
 }
 
 /// Returns the number of seconds that have elapsed between an arbitrary EPOCH and now.
-#[inline]
 fn current_second() -> u32 {
     lazy_static! {
         static ref EPOCH: Instant = Instant::now();
@@ -267,7 +250,6 @@ impl BandwidthSink {
             self.bytes.remove(0);
             self.bytes.push(0);
         }
-
         self.latest_update = current_second;
     }
 }

src/lib.rs

@@ -158,8 +158,6 @@ pub use futures;
 pub use multiaddr;
 #[doc(inline)]
 pub use multihash;
-pub use tokio_io;
-pub use tokio_codec;
 
 #[doc(inline)]
 pub use libp2p_core as core;
@@ -229,7 +227,7 @@ use std::{error, io, time::Duration};
 /// > **Note**: This `Transport` is not suitable for production usage, as its implementation
 /// >           reserves the right to support additional protocols or remove deprecated protocols.
 pub fn build_development_transport(keypair: identity::Keypair)
-    -> impl Transport<Output = (PeerId, impl core::muxing::StreamMuxer<OutboundSubstream = impl Send, Substream = impl Send, Error = impl Into<io::Error>> + Send + Sync), Error = impl error::Error + Send, Listener = impl Send, Dial = impl Send, ListenerUpgrade = impl Send> + Clone
+    -> io::Result<impl Transport<Output = (PeerId, impl core::muxing::StreamMuxer<OutboundSubstream = impl Send, Substream = impl Send, Error = impl Into<io::Error>> + Send + Sync), Error = impl error::Error + Send, Listener = impl Send, Dial = impl Send, ListenerUpgrade = impl Send> + Clone>
 {
      build_tcp_ws_secio_mplex_yamux(keypair)
 }
@@ -241,14 +239,14 @@ pub fn build_development_transport(keypair: identity::Keypair)
 ///
 /// > **Note**: If you ever need to express the type of this `Transport`.
 pub fn build_tcp_ws_secio_mplex_yamux(keypair: identity::Keypair)
-    -> impl Transport<Output = (PeerId, impl core::muxing::StreamMuxer<OutboundSubstream = impl Send, Substream = impl Send, Error = impl Into<io::Error>> + Send + Sync), Error = impl error::Error + Send, Listener = impl Send, Dial = impl Send, ListenerUpgrade = impl Send> + Clone
+    -> io::Result<impl Transport<Output = (PeerId, impl core::muxing::StreamMuxer<OutboundSubstream = impl Send, Substream = impl Send, Error = impl Into<io::Error>> + Send + Sync), Error = impl error::Error + Send, Listener = impl Send, Dial = impl Send, ListenerUpgrade = impl Send> + Clone>
 {
-    CommonTransport::new()
+    Ok(CommonTransport::new()?
         .upgrade(core::upgrade::Version::V1)
         .authenticate(secio::SecioConfig::new(keypair))
         .multiplex(core::upgrade::SelectUpgrade::new(yamux::Config::default(), mplex::MplexConfig::new()))
         .map(|(peer, muxer), _| (peer, core::muxing::StreamMuxerBox::new(muxer)))
-        .timeout(Duration::from_secs(20))
+        .timeout(Duration::from_secs(20)))
 }
 
 /// Implementation of `Transport` that supports the most common protocols.
@@ -276,27 +274,27 @@ struct CommonTransportInner {
 impl CommonTransport {
     /// Initializes the `CommonTransport`.
     #[cfg(not(any(target_os = "emscripten", target_os = "unknown")))]
-    pub fn new() -> CommonTransport {
+    pub fn new() -> io::Result<CommonTransport> {
         let tcp = tcp::TcpConfig::new().nodelay(true);
-        let transport = dns::DnsConfig::new(tcp);
+        let transport = dns::DnsConfig::new(tcp)?;
         #[cfg(feature = "libp2p-websocket")]
         let transport = {
             let trans_clone = transport.clone();
             transport.or_transport(websocket::WsConfig::new(trans_clone))
         };
 
-        CommonTransport {
+        Ok(CommonTransport {
             inner: CommonTransportInner { inner: transport }
-        }
+        })
     }
 
     /// Initializes the `CommonTransport`.
     #[cfg(any(target_os = "emscripten", target_os = "unknown"))]
-    pub fn new() -> CommonTransport {
+    pub fn new() -> io::Result<CommonTransport> {
         let inner = core::transport::dummy::DummyTransport::new();
-        CommonTransport {
+        Ok(CommonTransport {
             inner: CommonTransportInner { inner }
-        }
+        })
     }
 }
 

src/simple.rs

@@ -20,9 +20,8 @@
 
 use crate::core::upgrade::{InboundUpgrade, OutboundUpgrade, UpgradeInfo, Negotiated};
 use bytes::Bytes;
-use futures::{future::FromErr, prelude::*};
-use std::{iter, io::Error as IoError, sync::Arc};
-use tokio_io::{AsyncRead, AsyncWrite};
+use futures::prelude::*;
+use std::{iter, sync::Arc};
 
 /// Implementation of `ConnectionUpgrade`. Convenient to use with small protocols.
 #[derive(Debug)]
@@ -35,7 +34,6 @@ pub struct SimpleProtocol<F> {
 
 impl<F> SimpleProtocol<F> {
     /// Builds a `SimpleProtocol`.
-    #[inline]
     pub fn new<N>(info: N, upgrade: F) -> SimpleProtocol<F>
     where
         N: Into<Bytes>,
@@ -48,7 +46,6 @@ impl<F> SimpleProtocol<F> {
 }
 
 impl<F> Clone for SimpleProtocol<F> {
-    #[inline]
     fn clone(&self) -> Self {
         SimpleProtocol {
             info: self.info.clone(),
@@ -61,42 +58,39 @@ impl<F> UpgradeInfo for SimpleProtocol<F> {
     type Info = Bytes;
     type InfoIter = iter::Once<Self::Info>;
 
-    #[inline]
     fn protocol_info(&self) -> Self::InfoIter {
         iter::once(self.info.clone())
     }
 }
 
-impl<C, F, O> InboundUpgrade<C> for SimpleProtocol<F>
+impl<C, F, O, A, E> InboundUpgrade<C> for SimpleProtocol<F>
 where
     C: AsyncRead + AsyncWrite,
     F: Fn(Negotiated<C>) -> O,
-    O: IntoFuture<Error = IoError>
+    O: Future<Output = Result<A, E>> + Unpin
 {
-    type Output = O::Item;
-    type Error = IoError;
-    type Future = FromErr<O::Future, IoError>;
+    type Output = A;
+    type Error = E;
+    type Future = O;
 
-    #[inline]
     fn upgrade_inbound(self, socket: Negotiated<C>, _: Self::Info) -> Self::Future {
         let upgrade = &self.upgrade;
-        upgrade(socket).into_future().from_err()
+        upgrade(socket)
     }
 }
 
-impl<C, F, O> OutboundUpgrade<C> for SimpleProtocol<F>
+impl<C, F, O, A, E> OutboundUpgrade<C> for SimpleProtocol<F>
 where
     C: AsyncRead + AsyncWrite,
     F: Fn(Negotiated<C>) -> O,
-    O: IntoFuture<Error = IoError>
+    O: Future<Output = Result<A, E>> + Unpin
 {
-    type Output = O::Item;
-    type Error = IoError;
-    type Future = FromErr<O::Future, IoError>;
+    type Output = A;
+    type Error = E;
+    type Future = O;
 
-    #[inline]
     fn upgrade_outbound(self, socket: Negotiated<C>, _: Self::Info) -> Self::Future {
         let upgrade = &self.upgrade;
-        upgrade(socket).into_future().from_err()
+        upgrade(socket)
     }
 }

transports/dns/src/lib.rs

@@ -33,14 +33,14 @@
 //! replaced with respectively an `/ip4/` or an `/ip6/` component.
 //!
 
-use futures::{prelude::*, channel::oneshot};
+use futures::{prelude::*, channel::oneshot, future::BoxFuture};
 use libp2p_core::{
     Transport,
     multiaddr::{Protocol, Multiaddr},
     transport::{TransportError, ListenerEvent}
 };
 use log::{error, debug, trace};
-use std::{error, fmt, io, net::ToSocketAddrs, pin::Pin};
+use std::{error, fmt, io, net::ToSocketAddrs};
 
 /// Represents the configuration for a DNS transport capability of libp2p.
 ///
@@ -90,8 +90,9 @@ where
 
 impl<T> Transport for DnsConfig<T>
 where
-    T: Transport + 'static,
-    T::Error: 'static,
+    T: Transport + Send + 'static,
+    T::Error: Send,
+    T::Dial: Send
 {
     type Output = T::Output;
     type Error = DnsErr<T::Error>;
@@ -102,7 +103,7 @@ where
     type ListenerUpgrade = future::MapErr<T::ListenerUpgrade, fn(T::Error) -> Self::Error>;
     type Dial = future::Either<
         future::MapErr<T::Dial, fn(T::Error) -> Self::Error>,
-        Pin<Box<dyn Future<Output = Result<Self::Output, Self::Error>>>>
+        BoxFuture<'static, Result<Self::Output, Self::Error>>
     >;
 
     fn listen_on(self, addr: Multiaddr) -> Result<Self::Listener, TransportError<Self::Error>> {
@@ -166,21 +167,21 @@ where
             })
             .collect::<stream::FuturesOrdered<_>>();
 
-        let inner = self.inner;
-        Ok(future::Either::Right(Box::pin(async {
-            let addr = addr;
-            let outcome: Vec<_> = resolve_futs.collect().await;
+        let future = resolve_futs.collect::<Vec<_>>()
+            .then(move |outcome| async move {
                 let outcome = outcome.into_iter().collect::<Result<Vec<_>, _>>()?;
                 let outcome = outcome.into_iter().collect::<Multiaddr>();
                 debug!("DNS resolution outcome: {} => {}", addr, outcome);
 
-            match inner.dial(outcome) {
+                match self.inner.dial(outcome) {
                     Ok(d) => d.await.map_err(DnsErr::Underlying),
                     Err(TransportError::MultiaddrNotSupported(_addr)) =>
                         Err(DnsErr::MultiaddrNotSupported),
-                Err(TransportError::Other(err)) => Err(DnsErr::Underlying(err)),
+                    Err(TransportError::Other(err)) => Err(DnsErr::Underlying(err))
                 }
-        }) as Pin<Box<_>>))
+            });
+
+        Ok(future.boxed().right_future())
     }
 }
 
@@ -231,14 +232,13 @@ where TErr: error::Error + 'static
 #[cfg(test)]
 mod tests {
     use super::DnsConfig;
-    use futures::prelude::*;
+    use futures::{future::BoxFuture, prelude::*, stream::BoxStream};
     use libp2p_core::{
         Transport,
         multiaddr::{Protocol, Multiaddr},
         transport::ListenerEvent,
         transport::TransportError,
     };
-    use std::pin::Pin;
 
     #[test]
     fn basic_resolve() {
@@ -248,9 +248,9 @@ mod tests {
         impl Transport for CustomTransport {
             type Output = ();
             type Error = std::io::Error;
-            type Listener = Pin<Box<dyn Stream<Item = Result<ListenerEvent<Self::ListenerUpgrade>, Self::Error>>>>;
-            type ListenerUpgrade = Pin<Box<dyn Future<Output = Result<Self::Output, Self::Error>>>>;
-            type Dial = Pin<Box<dyn Future<Output = Result<Self::Output, Self::Error>>>>;
+            type Listener = BoxStream<'static, Result<ListenerEvent<Self::ListenerUpgrade>, Self::Error>>;
+            type ListenerUpgrade = BoxFuture<'static, Result<Self::Output, Self::Error>>;
+            type Dial = BoxFuture<'static, Result<Self::Output, Self::Error>>;
 
             fn listen_on(self, _: Multiaddr) -> Result<Self::Listener, TransportError<Self::Error>> {
                 unreachable!()