feat(request-response): add modules for json and cbor messages

This patch adds two modules to `libp2p::request_response`:

- `cbor`
- `json`

Both define a `Behaviour` type-alias that comes with a `Codec` implementation which uses the respective `serde` crate to serialize and deserialize the messages.

Fixes #3905.

Pull-Request: #3952.

Cargo.lock

@@ -2980,6 +2980,7 @@ dependencies = [
  "async-trait",
  "env_logger 0.10.0",
  "futures",
+ "futures_ringbuf",
  "instant",
  "libp2p-core",
  "libp2p-identity",
@@ -2990,6 +2991,9 @@ dependencies = [
  "libp2p-yamux",
  "log",
  "rand 0.8.5",
+ "serde",
+ "serde_cbor",
+ "serde_json",
  "smallvec",
  "void",
 ]
@@ -4653,6 +4657,16 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_cbor"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2bef2ebfde456fb76bbcf9f59315333decc4fda0b2b44b420243c11e0f5ec1f5"
+dependencies = [
+ "half",
+ "serde",
+]
+
 [[package]]
 name = "serde_derive"
 version = "1.0.163"

examples/file-sharing/src/network.rs

@@ -60,7 +60,7 @@ pub(crate) async fn new(
         transport,
         ComposedBehaviour {
             kademlia: Kademlia::new(peer_id, MemoryStore::new(peer_id)),
-            request_response: request_response::Behaviour::new(
+            request_response: request_response::Behaviour::with_codec(
                 FileExchangeCodec(),
                 iter::once((
                     StreamProtocol::new("/file-exchange/1"),

protocols/autonat/src/behaviour.rs

@@ -222,7 +222,7 @@ impl Behaviour {
         let protocols = iter::once((DEFAULT_PROTOCOL_NAME, ProtocolSupport::Full));
         let mut cfg = request_response::Config::default();
         cfg.set_request_timeout(config.timeout);
-        let inner = request_response::Behaviour::new(AutoNatCodec, protocols, cfg);
+        let inner = request_response::Behaviour::with_codec(AutoNatCodec, protocols, cfg);
         Self {
             local_peer_id,
             inner,

protocols/request-response/CHANGELOG.md

@@ -1,5 +1,9 @@
 ## 0.25.0 - unreleased
 
+- Add `request_response::json::Behaviour` and `request_response::cbor::Behaviour` building on top of the `serde` traits.
+  To conveniently construct these, we remove the `Codec` parameter from `Behaviour::new` and add `Behaviour::with_codec`.
+  See [PR 3952].
+
 - Raise MSRV to 1.65.
   See [PR 3715].
 - Remove deprecated `RequestResponse` prefixed items. See [PR 3702].
@@ -12,6 +16,7 @@
   Log the error instead.
   See [PR 3913].
 
+[PR 3952]: https://github.com/libp2p/rust-libp2p/pull/3952
 [PR 3605]: https://github.com/libp2p/rust-libp2p/pull/3605
 [PR 3715]: https://github.com/libp2p/rust-libp2p/pull/3715
 [PR 3702]: https://github.com/libp2p/rust-libp2p/pull/3702

protocols/request-response/Cargo.toml

@@ -18,10 +18,17 @@ libp2p-core = { workspace = true }
 libp2p-swarm = { workspace = true }
 libp2p-identity = { workspace = true }
 rand = "0.8"
+serde = { version = "1.0", optional = true}
+serde_json = { version = "1.0.96", optional = true }
+serde_cbor = { version = "0.11.2", optional = true }
 smallvec = "1.6.1"
 void = "1.0.2"
 log = "0.4.17"
 
+[features]
+json = ["dep:serde", "dep:serde_json", "libp2p-swarm/macros"]
+cbor = ["dep:serde", "dep:serde_cbor", "libp2p-swarm/macros"]
+
 [dev-dependencies]
 async-std = { version = "1.6.2", features = ["attributes"] }
 env_logger = "0.10.0"
@@ -30,6 +37,8 @@ libp2p-tcp = { workspace = true, features = ["async-io"] }
 libp2p-yamux = { workspace = true }
 rand = "0.8"
 libp2p-swarm-test = { workspace = true }
+futures_ringbuf = "0.3.1"
+serde = { version = "1.0", features = ["derive"]}
 
 # Passing arguments to the docsrs builder in order to properly document cfg's.
 # More information: https://docs.rs/about/builds#cross-compiling

protocols/request-response/src/cbor.rs

@@ -0,0 +1,214 @@
+// Copyright 2023 Protocol Labs
+//
+// 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.
+
+/// A request-response behaviour using [`serde_cbor`] for serializing and deserializing the messages.
+///
+/// # Example
+///
+/// ```
+/// # use libp2p_request_response::{cbor, ProtocolSupport, self as request_response};
+/// # use libp2p_swarm::{StreamProtocol, SwarmBuilder};
+/// #[derive(Debug, serde::Serialize, serde::Deserialize)]
+/// struct GreetRequest {
+///     name: String,
+/// }
+///
+/// #[derive(Debug, serde::Serialize, serde::Deserialize)]
+/// struct GreetResponse {
+///     message: String,
+/// }
+///
+/// let behaviour = cbor::Behaviour::<GreetRequest, GreetResponse>::new(
+///     [(StreamProtocol::new("/my-cbor-protocol"), ProtocolSupport::Full)],
+///     request_response::Config::default()
+/// );
+/// ```
+pub type Behaviour<Req, Resp> = crate::Behaviour<codec::Codec<Req, Resp>>;
+
+mod codec {
+    use async_trait::async_trait;
+    use futures::prelude::*;
+    use futures::{AsyncRead, AsyncWrite};
+    use libp2p_swarm::StreamProtocol;
+    use serde::{de::DeserializeOwned, Serialize};
+    use std::{io, marker::PhantomData};
+
+    /// Max request size in bytes
+    const REQUEST_SIZE_MAXIMUM: u64 = 1024 * 1024;
+    /// Max response size in bytes
+    const RESPONSE_SIZE_MAXIMUM: u64 = 10 * 1024 * 1024;
+
+    pub struct Codec<Req, Resp> {
+        phantom: PhantomData<(Req, Resp)>,
+    }
+
+    impl<Req, Resp> Default for Codec<Req, Resp> {
+        fn default() -> Self {
+            Codec {
+                phantom: PhantomData,
+            }
+        }
+    }
+
+    impl<Req, Resp> Clone for Codec<Req, Resp> {
+        fn clone(&self) -> Self {
+            Self::default()
+        }
+    }
+
+    #[async_trait]
+    impl<Req, Resp> crate::Codec for Codec<Req, Resp>
+    where
+        Req: Send + Serialize + DeserializeOwned,
+        Resp: Send + Serialize + DeserializeOwned,
+    {
+        type Protocol = StreamProtocol;
+        type Request = Req;
+        type Response = Resp;
+
+        async fn read_request<T>(&mut self, _: &Self::Protocol, io: &mut T) -> io::Result<Req>
+        where
+            T: AsyncRead + Unpin + Send,
+        {
+            let mut vec = Vec::new();
+
+            io.take(REQUEST_SIZE_MAXIMUM).read_to_end(&mut vec).await?;
+
+            serde_cbor::from_slice(vec.as_slice()).map_err(into_io_error)
+        }
+
+        async fn read_response<T>(&mut self, _: &Self::Protocol, io: &mut T) -> io::Result<Resp>
+        where
+            T: AsyncRead + Unpin + Send,
+        {
+            let mut vec = Vec::new();
+
+            io.take(RESPONSE_SIZE_MAXIMUM).read_to_end(&mut vec).await?;
+
+            serde_cbor::from_slice(vec.as_slice()).map_err(into_io_error)
+        }
+
+        async fn write_request<T>(
+            &mut self,
+            _: &Self::Protocol,
+            io: &mut T,
+            req: Self::Request,
+        ) -> io::Result<()>
+        where
+            T: AsyncWrite + Unpin + Send,
+        {
+            let data: Vec<u8> = serde_cbor::to_vec(&req).map_err(into_io_error)?;
+
+            io.write_all(data.as_ref()).await?;
+
+            Ok(())
+        }
+
+        async fn write_response<T>(
+            &mut self,
+            _: &Self::Protocol,
+            io: &mut T,
+            resp: Self::Response,
+        ) -> io::Result<()>
+        where
+            T: AsyncWrite + Unpin + Send,
+        {
+            let data: Vec<u8> = serde_cbor::to_vec(&resp).map_err(into_io_error).unwrap();
+
+            io.write_all(data.as_ref()).await?;
+
+            Ok(())
+        }
+    }
+
+    fn into_io_error(err: serde_cbor::Error) -> io::Error {
+        if err.is_syntax() || err.is_data() {
+            return io::Error::new(io::ErrorKind::InvalidData, err);
+        }
+
+        if err.is_eof() {
+            return io::Error::new(io::ErrorKind::UnexpectedEof, err);
+        }
+
+        io::Error::new(io::ErrorKind::Other, err)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::cbor::codec::Codec;
+    use crate::Codec as _;
+    use futures::AsyncWriteExt;
+    use futures_ringbuf::Endpoint;
+    use libp2p_swarm::StreamProtocol;
+    use serde::{Deserialize, Serialize};
+
+    #[async_std::test]
+    async fn test_codec() {
+        let expected_request = TestRequest {
+            payload: "test_payload".to_string(),
+        };
+        let expected_response = TestResponse {
+            payload: "test_payload".to_string(),
+        };
+        let protocol = StreamProtocol::new("/test_cbor/1");
+        let mut codec = Codec::default();
+
+        let (mut a, mut b) = Endpoint::pair(124, 124);
+        codec
+            .write_request(&protocol, &mut a, expected_request.clone())
+            .await
+            .expect("Should write request");
+        a.close().await.unwrap();
+
+        let actual_request = codec
+            .read_request(&protocol, &mut b)
+            .await
+            .expect("Should read request");
+        b.close().await.unwrap();
+
+        assert_eq!(actual_request, expected_request);
+
+        let (mut a, mut b) = Endpoint::pair(124, 124);
+        codec
+            .write_response(&protocol, &mut a, expected_response.clone())
+            .await
+            .expect("Should write response");
+        a.close().await.unwrap();
+
+        let actual_response = codec
+            .read_response(&protocol, &mut b)
+            .await
+            .expect("Should read response");
+        b.close().await.unwrap();
+
+        assert_eq!(actual_response, expected_response);
+    }
+
+    #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+    struct TestRequest {
+        payload: String,
+    }
+
+    #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+    struct TestResponse {
+        payload: String,
+    }
+}

protocols/request-response/src/json.rs

@@ -0,0 +1,202 @@
+// Copyright 2023 Protocol Labs
+//
+// 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.
+
+/// A request-response behaviour using [`serde_json`] for serializing and deserializing the messages.
+///
+/// # Example
+///
+/// ```
+/// # use libp2p_request_response::{json, ProtocolSupport, self as request_response};
+/// # use libp2p_swarm::{StreamProtocol};
+/// #[derive(Debug, serde::Serialize, serde::Deserialize)]
+/// struct GreetRequest {
+///     name: String,
+/// }
+///
+/// #[derive(Debug, serde::Serialize, serde::Deserialize)]
+/// struct GreetResponse {
+///     message: String,
+/// }
+///
+/// let behaviour = json::Behaviour::<GreetRequest, GreetResponse>::new(
+///     [(StreamProtocol::new("/my-json-protocol"), ProtocolSupport::Full)],
+///     request_response::Config::default()
+/// );
+/// ```
+pub type Behaviour<Req, Resp> = crate::Behaviour<codec::Codec<Req, Resp>>;
+
+mod codec {
+    use async_trait::async_trait;
+    use futures::prelude::*;
+    use futures::{AsyncRead, AsyncWrite};
+    use libp2p_swarm::StreamProtocol;
+    use serde::{de::DeserializeOwned, Serialize};
+    use std::{io, marker::PhantomData};
+
+    /// Max request size in bytes
+    const REQUEST_SIZE_MAXIMUM: u64 = 1024 * 1024;
+    /// Max response size in bytes
+    const RESPONSE_SIZE_MAXIMUM: u64 = 10 * 1024 * 1024;
+
+    pub struct Codec<Req, Resp> {
+        phantom: PhantomData<(Req, Resp)>,
+    }
+
+    impl<Req, Resp> Default for Codec<Req, Resp> {
+        fn default() -> Self {
+            Codec {
+                phantom: PhantomData,
+            }
+        }
+    }
+
+    impl<Req, Resp> Clone for Codec<Req, Resp> {
+        fn clone(&self) -> Self {
+            Self::default()
+        }
+    }
+
+    #[async_trait]
+    impl<Req, Resp> crate::Codec for Codec<Req, Resp>
+    where
+        Req: Send + Serialize + DeserializeOwned,
+        Resp: Send + Serialize + DeserializeOwned,
+    {
+        type Protocol = StreamProtocol;
+        type Request = Req;
+        type Response = Resp;
+
+        async fn read_request<T>(&mut self, _: &Self::Protocol, io: &mut T) -> io::Result<Req>
+        where
+            T: AsyncRead + Unpin + Send,
+        {
+            let mut vec = Vec::new();
+
+            io.take(REQUEST_SIZE_MAXIMUM).read_to_end(&mut vec).await?;
+
+            Ok(serde_json::from_slice(vec.as_slice())?)
+        }
+
+        async fn read_response<T>(&mut self, _: &Self::Protocol, io: &mut T) -> io::Result<Resp>
+        where
+            T: AsyncRead + Unpin + Send,
+        {
+            let mut vec = Vec::new();
+
+            io.take(RESPONSE_SIZE_MAXIMUM).read_to_end(&mut vec).await?;
+
+            Ok(serde_json::from_slice(vec.as_slice())?)
+        }
+
+        async fn write_request<T>(
+            &mut self,
+            _: &Self::Protocol,
+            io: &mut T,
+            req: Self::Request,
+        ) -> io::Result<()>
+        where
+            T: AsyncWrite + Unpin + Send,
+        {
+            let data = serde_json::to_vec(&req)?;
+
+            io.write_all(data.as_ref()).await?;
+
+            Ok(())
+        }
+
+        async fn write_response<T>(
+            &mut self,
+            _: &Self::Protocol,
+            io: &mut T,
+            resp: Self::Response,
+        ) -> io::Result<()>
+        where
+            T: AsyncWrite + Unpin + Send,
+        {
+            let data = serde_json::to_vec(&resp)?;
+
+            io.write_all(data.as_ref()).await?;
+
+            Ok(())
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::Codec;
+    use futures::AsyncWriteExt;
+    use futures_ringbuf::Endpoint;
+    use libp2p_swarm::StreamProtocol;
+    use serde::{Deserialize, Serialize};
+
+    #[async_std::test]
+    async fn test_codec() {
+        let expected_request = TestRequest {
+            payload: "test_payload".to_string(),
+        };
+        let expected_response = TestResponse {
+            payload: "test_payload".to_string(),
+        };
+        let protocol = StreamProtocol::new("/test_json/1");
+        let mut codec: super::codec::Codec<TestRequest, TestResponse> =
+            super::codec::Codec::default();
+
+        let (mut a, mut b) = Endpoint::pair(124, 124);
+        codec
+            .write_request(&protocol, &mut a, expected_request.clone())
+            .await
+            .expect("Should write request");
+        a.close().await.unwrap();
+
+        let actual_request = codec
+            .read_request(&protocol, &mut b)
+            .await
+            .expect("Should read request");
+        b.close().await.unwrap();
+
+        assert_eq!(actual_request, expected_request);
+
+        let (mut a, mut b) = Endpoint::pair(124, 124);
+        codec
+            .write_response(&protocol, &mut a, expected_response.clone())
+            .await
+            .expect("Should write response");
+        a.close().await.unwrap();
+
+        let actual_response = codec
+            .read_response(&protocol, &mut b)
+            .await
+            .expect("Should read response");
+        b.close().await.unwrap();
+
+        assert_eq!(actual_response, expected_response);
+    }
+
+    #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+    struct TestRequest {
+        payload: String,
+    }
+
+    #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+    struct TestResponse {
+        payload: String,
+    }
+}

protocols/request-response/src/lib.rs

@@ -28,7 +28,7 @@
 //! over the actual messages being sent, which are defined in terms of a
 //! [`Codec`]. Creating a request/response protocol thus amounts
 //! to providing an implementation of this trait which can then be
-//! given to [`Behaviour::new`]. Further configuration options are
+//! given to [`Behaviour::with_codec`]. Further configuration options are
 //! available via the [`Config`].
 //!
 //! Requests are sent using [`Behaviour::send_request`] and the
@@ -39,6 +39,14 @@
 //! receiving a [`Message::Request`] via
 //! [`Event::Message`].
 //!
+//! ## Predefined codecs
+//!
+//! In case your message types implement [`serde::Serialize`] and [`serde::Deserialize`],
+//! you can use two predefined behaviours:
+//!
+//! - [`cbor::Behaviour`] for CBOR-encoded messages
+//! - [`json::Behaviour`] for JSON-encoded messages
+//!
 //! ## Protocol Families
 //!
 //! A single [`Behaviour`] instance can be used with an entire
@@ -58,8 +66,12 @@
 
 #![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
 
+#[cfg(feature = "cbor")]
+pub mod cbor;
 mod codec;
 mod handler;
+#[cfg(feature = "json")]
+pub mod json;
 
 pub use codec::Codec;
 pub use handler::ProtocolSupport;
@@ -328,13 +340,26 @@ where
     pending_outbound_requests: HashMap<PeerId, SmallVec<[RequestProtocol<TCodec>; 10]>>,
 }
 
+impl<TCodec> Behaviour<TCodec>
+where
+    TCodec: Codec + Default + Clone + Send + 'static,
+{
+    /// Creates a new `Behaviour` for the given protocols and configuration, using [`Default`] to construct the codec.
+    pub fn new<I>(protocols: I, cfg: Config) -> Self
+    where
+        I: IntoIterator<Item = (TCodec::Protocol, ProtocolSupport)>,
+    {
+        Self::with_codec(TCodec::default(), protocols, cfg)
+    }
+}
+
 impl<TCodec> Behaviour<TCodec>
 where
     TCodec: Codec + Clone + Send + 'static,
 {
     /// Creates a new `Behaviour` for the given
     /// protocols, codec and configuration.
-    pub fn new<I>(codec: TCodec, protocols: I, cfg: Config) -> Self
+    pub fn with_codec<I>(codec: TCodec, protocols: I, cfg: Config) -> Self
     where
         I: IntoIterator<Item = (TCodec::Protocol, ProtocolSupport)>,
     {

protocols/request-response/tests/ping.rs

@@ -43,8 +43,9 @@ async fn is_response_outbound() {
     ));
     let cfg = request_response::Config::default();
 
-    let mut swarm1 =
-        Swarm::new_ephemeral(|_| request_response::Behaviour::new(PingCodec(), protocols, cfg));
+    let mut swarm1 = Swarm::new_ephemeral(|_| {
+        request_response::Behaviour::with_codec(PingCodec(), protocols, cfg)
+    });
 
     let request_id1 = swarm1
         .behaviour_mut()
@@ -87,11 +88,12 @@ async fn ping_protocol() {
     let cfg = request_response::Config::default();
 
     let mut swarm1 = Swarm::new_ephemeral(|_| {
-        request_response::Behaviour::new(PingCodec(), protocols.clone(), cfg.clone())
+        request_response::Behaviour::with_codec(PingCodec(), protocols.clone(), cfg.clone())
     });
     let peer1_id = *swarm1.local_peer_id();
-    let mut swarm2 =
-        Swarm::new_ephemeral(|_| request_response::Behaviour::new(PingCodec(), protocols, cfg));
+    let mut swarm2 = Swarm::new_ephemeral(|_| {
+        request_response::Behaviour::with_codec(PingCodec(), protocols, cfg)
+    });
     let peer2_id = *swarm2.local_peer_id();
 
     swarm1.listen().await;
@@ -178,11 +180,12 @@ async fn emits_inbound_connection_closed_failure() {
     let cfg = request_response::Config::default();
 
     let mut swarm1 = Swarm::new_ephemeral(|_| {
-        request_response::Behaviour::new(PingCodec(), protocols.clone(), cfg.clone())
+        request_response::Behaviour::with_codec(PingCodec(), protocols.clone(), cfg.clone())
     });
     let peer1_id = *swarm1.local_peer_id();
-    let mut swarm2 =
-        Swarm::new_ephemeral(|_| request_response::Behaviour::new(PingCodec(), protocols, cfg));
+    let mut swarm2 = Swarm::new_ephemeral(|_| {
+        request_response::Behaviour::with_codec(PingCodec(), protocols, cfg)
+    });
     let peer2_id = *swarm2.local_peer_id();
 
     swarm1.listen().await;
@@ -241,11 +244,12 @@ async fn emits_inbound_connection_closed_if_channel_is_dropped() {
     let cfg = request_response::Config::default();
 
     let mut swarm1 = Swarm::new_ephemeral(|_| {
-        request_response::Behaviour::new(PingCodec(), protocols.clone(), cfg.clone())
+        request_response::Behaviour::with_codec(PingCodec(), protocols.clone(), cfg.clone())
     });
     let peer1_id = *swarm1.local_peer_id();
-    let mut swarm2 =
-        Swarm::new_ephemeral(|_| request_response::Behaviour::new(PingCodec(), protocols, cfg));
+    let mut swarm2 = Swarm::new_ephemeral(|_| {
+        request_response::Behaviour::with_codec(PingCodec(), protocols, cfg)
+    });
     let peer2_id = *swarm2.local_peer_id();
 
     swarm1.listen().await;