Custom ProtocolsHandler and multiple protocols.

  1. Implement a custom ProtocolsHandler instead of using
     the OneShotHandler for better control and error handling.
     In particular, all request/response sending/receiving is
     kept in the substreams upgrades and thus the background
     task of a connection.
  2. Support multiple protocols (usually protocol versions)
     with a single `RequestResponse` instance, with
     configurable inbound/outbound support.

protocols/request-response/Cargo.toml

@@ -10,11 +10,11 @@ keywords = ["peer-to-peer", "libp2p", "networking"]
 categories = ["network-programming", "asynchronous"]
 
 [dependencies]
-bytes = "0.5"
 futures = "0.3.1"
 libp2p-core = { version = "0.19.0", path = "../../core" }
 libp2p-swarm = { version = "0.19.0", path = "../../swarm" }
 smallvec = "1.4"
+wasm-timer = "0.2"
 
 [dev-dependencies]
 async-std = "< 1.6"

protocols/request-response/src/codec.rs

@@ -0,0 +1,64 @@
+// 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.
+
+pub use libp2p_core::ProtocolName;
+
+use futures::{prelude::*, future::BoxFuture};
+use std::io;
+
+/// A `RequestResponseCodec` defines the request and response types
+/// for a [`RequestResponse`](crate::RequestResponse) protocol or
+/// protocol family and how they are encoded / decoded on an I/O stream.
+pub trait RequestResponseCodec {
+    /// The type of protocol(s) or protocol versions being negotiated.
+    type Protocol: ProtocolName + Send + Sync + Clone;
+    /// The type of inbound and outbound requests.
+    type Request: Send + Clone;
+    /// The type of inbound and outbound responses.
+    type Response: Send;
+
+    /// Reads a request from the given I/O stream according to the
+    /// negotiated protocol.
+    fn read_request<'a, T>(&mut self, protocol: &Self::Protocol, io: &'a mut T)
+        -> BoxFuture<'a, Result<Self::Request, io::Error>>
+    where
+        T: AsyncRead + Unpin + Send;
+
+    /// Reads a response from the given I/O stream according to the
+    /// negotiated protocol.
+    fn read_response<'a, T>(&mut self, protocol: &Self::Protocol, io: &'a mut T)
+        -> BoxFuture<'a, Result<Self::Response, io::Error>>
+    where
+        T: AsyncRead + Unpin + Send;
+
+    /// Writes a request to the given I/O stream according to the
+    /// negotiated protocol.
+    fn write_request<'a, T>(&mut self, protocol: &Self::Protocol, io: &'a mut T, req: Self::Request)
+        -> BoxFuture<'a, Result<(), io::Error>>
+    where
+        T: AsyncWrite + Unpin + Send;
+
+    /// Writes a response to the given I/O stream according to the
+    /// negotiated protocol.
+    fn write_response<'a, T>(&mut self, protocol: &Self::Protocol, io: &'a mut T, res: Self::Response)
+        -> BoxFuture<'a, Result<(), io::Error>>
+    where
+        T: AsyncWrite + Unpin + Send;
+}