fix(libp2p): Vendor from_fn, FromFnUpgrade which were removed

swap/src/network/swap_setup.rs

@@ -9,6 +9,7 @@ use serde::{Deserialize, Serialize};
 
 pub mod alice;
 pub mod bob;
+mod vendor_from_fn;
 
 pub const BUF_SIZE: usize = 1024 * 1024;
 
@@ -18,15 +19,17 @@ pub mod protocol {
     use libp2p::swarm::Stream;
     use void::Void;
 
+    use super::vendor_from_fn::{from_fn, FromFnUpgrade};
+
     pub fn new() -> SwapSetup {
         from_fn(
-            b"/comit/xmr/btc/swap_setup/1.0.0",
+            "/comit/xmr/btc/swap_setup/1.0.0",
             Box::new(|socket, _| future::ready(Ok(socket))),
         )
     }
 
     pub type SwapSetup = FromFnUpgrade<
-        &'static [u8],
+        &'static str,
         Box<dyn Fn(Stream, Endpoint) -> future::Ready<Result<Stream, Void>> + Send + 'static>,
     >;
 }

swap/src/network/swap_setup/vendor_from_fn.rs

@@ -0,0 +1,114 @@
+// Copyright 2020 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.
+
+// These functions have been vendored from https://github.com/libp2p/rust-libp2p/blob/v0.51.0/core/src/upgrade/from_fn.rs because they were removed from the library itself
+// This is recommended, see: https://github.com/libp2p/rust-libp2p/pull/3747
+// We replaced ProtocolName with AsRef<str>. See: https://github.com/libp2p/rust-libp2p/pull/3746/files
+
+use futures::prelude::*;
+use libp2p::{core::{Endpoint, UpgradeInfo}, InboundUpgrade, OutboundUpgrade};
+use std::iter;
+
+/// Initializes a new [`FromFnUpgrade`].
+///
+/// # Example
+///
+/// ```
+/// # use libp2p_core::transport::{Transport, MemoryTransport, memory::Channel};
+/// # use libp2p_core::{upgrade, Negotiated};
+/// # use std::io;
+/// # use futures::AsyncWriteExt;
+/// let _transport = MemoryTransport::default()
+///     .and_then(move |out, cp| {
+///         upgrade::apply(out, upgrade::from_fn("/foo/1", move |mut sock: Negotiated<Channel<Vec<u8>>>, endpoint| async move {
+///             if endpoint.is_dialer() {
+///                 upgrade::write_length_prefixed(&mut sock, "some handshake data").await?;
+///                 sock.close().await?;
+///             } else {
+///                 let handshake_data = upgrade::read_length_prefixed(&mut sock, 1024).await?;
+///                 if handshake_data != b"some handshake data" {
+///                     return Err(io::Error::new(io::ErrorKind::Other, "bad handshake"));
+///                 }
+///             }
+///             Ok(sock)
+///         }), cp, upgrade::Version::V1)
+///     });
+/// ```
+///
+pub fn from_fn<P, F, C, Fut, Out, Err>(protocol_name: P, fun: F) -> FromFnUpgrade<P, F>
+where
+    // Note: these bounds are there in order to help the compiler infer types
+    P: AsRef<str> + Clone,
+    F: FnOnce(C, Endpoint) -> Fut,
+    Fut: Future<Output = Result<Out, Err>>,
+{
+    FromFnUpgrade { protocol_name, fun }
+}
+
+/// Implements the `UpgradeInfo`, `InboundUpgrade` and `OutboundUpgrade` traits.
+///
+/// The upgrade consists in calling the function passed when creating this struct.
+#[derive(Debug, Clone)]
+pub struct FromFnUpgrade<P, F> {
+    protocol_name: P,
+    fun: F,
+}
+
+impl<P, F> UpgradeInfo for FromFnUpgrade<P, F>
+where
+    P: AsRef<str> + Clone,
+{
+    type Info = P;
+    type InfoIter = iter::Once<P>;
+
+    fn protocol_info(&self) -> Self::InfoIter {
+        iter::once(self.protocol_name.clone())
+    }
+}
+
+impl<C, P, F, Fut, Err, Out> InboundUpgrade<C> for FromFnUpgrade<P, F>
+where
+    P: AsRef<str> + Clone,
+    F: FnOnce(C, Endpoint) -> Fut,
+    Fut: Future<Output = Result<Out, Err>>,
+{
+    type Output = Out;
+    type Error = Err;
+    type Future = Fut;
+
+    fn upgrade_inbound(self, sock: C, _: Self::Info) -> Self::Future {
+        (self.fun)(sock, Endpoint::Listener)
+    }
+}
+
+impl<C, P, F, Fut, Err, Out> OutboundUpgrade<C> for FromFnUpgrade<P, F>
+where
+    P: AsRef<str> + Clone,
+    F: FnOnce(C, Endpoint) -> Fut,
+    Fut: Future<Output = Result<Out, Err>>,
+{
+    type Output = Out;
+    type Error = Err;
+    type Future = Fut;
+
+    fn upgrade_outbound(self, sock: C, _: Self::Info) -> Self::Future {
+        (self.fun)(sock, Endpoint::Dialer)
+    }
+}