further work on streams

most changes still required are related to error handling

src/client.rs

@@ -227,9 +227,8 @@ impl ClientConn {
 
 		let code = resp[0];
 		if code == 0 {
-			let mut deser = rmp_serde::decode::Deserializer::from_read_ref(&resp[1..]);
-			let res = T::Response::deserialize_msg(&mut deser, stream).await?;
-			Ok(res)
+			let ser_resp = rmp_serde::decode::from_read_ref(&resp[1..])?;
+			Ok(T::Response::deserialize_msg(ser_resp, stream).await)
 		} else {
 			let msg = String::from_utf8(resp[1..].to_vec()).unwrap_or_default();
 			Err(Error::Remote(code, msg))

src/endpoint.rs

@@ -5,8 +5,7 @@ use std::sync::Arc;
 use arc_swap::ArcSwapOption;
 use async_trait::async_trait;
 
-use serde::de::Error as DeError;
-use serde::{Deserialize, Deserializer, Serialize, Serializer};
+use serde::{Deserialize, Serialize};
 
 use crate::error::Error;
 use crate::netapp::*;
@@ -22,42 +21,61 @@ pub trait Message: SerializeMessage + Send + Sync {
 /// A trait for de/serializing messages, with possible associated stream.
 #[async_trait]
 pub trait SerializeMessage: Sized {
-	fn serialize_msg<S: Serializer>(
-		&self,
-		serializer: S,
-	) -> Result<(S::Ok, Option<AssociatedStream>), S::Error>;
+	type SerializableSelf: Serialize + for<'de> Deserialize<'de> + Send;
 
-	async fn deserialize_msg<'de, D: Deserializer<'de> + Send>(
-		deserializer: D,
-		stream: AssociatedStream,
-	) -> Result<Self, D::Error>;
+	// TODO should return Result
+	fn serialize_msg(&self) -> (Self::SerializableSelf, Option<AssociatedStream>);
+
+	// TODO should return Result
+	async fn deserialize_msg(ser_self: Self::SerializableSelf, stream: AssociatedStream) -> Self;
 }
 
+pub trait AutoSerialize: Serialize + for<'de> Deserialize<'de> + Clone + Send + Sync {}
+
 #[async_trait]
 impl<T> SerializeMessage for T
 where
-	T: Serialize + for<'de> Deserialize<'de> + Send + Sync,
+	T: AutoSerialize,
 {
-	fn serialize_msg<S: Serializer>(
-		&self,
-		serializer: S,
-	) -> Result<(S::Ok, Option<AssociatedStream>), S::Error> {
-		self.serialize(serializer).map(|r| (r, None))
+	type SerializableSelf = Self;
+	fn serialize_msg(&self) -> (Self::SerializableSelf, Option<AssociatedStream>) {
+		(self.clone(), None)
 	}
 
-	async fn deserialize_msg<'de, D: Deserializer<'de> + Send>(
-		deserializer: D,
-		mut stream: AssociatedStream,
-	) -> Result<Self, D::Error> {
-		use futures::StreamExt;
+	async fn deserialize_msg(ser_self: Self::SerializableSelf, stream: AssociatedStream) -> Self {
+		// TODO verify no stream
+		ser_self
+	}
+}
 
-		let res = Self::deserialize(deserializer)?;
-		if stream.next().await.is_some() {
-			return Err(D::Error::custom(
-				"failed to deserialize: found associated stream when none expected",
-			));
+impl AutoSerialize for () {}
+
+#[async_trait]
+impl<T, E> SerializeMessage for Result<T, E>
+where
+	T: SerializeMessage + Send,
+	E: SerializeMessage + Send,
+{
+	type SerializableSelf = Result<T::SerializableSelf, E::SerializableSelf>;
+
+	fn serialize_msg(&self) -> (Self::SerializableSelf, Option<AssociatedStream>) {
+		match self {
+			Ok(ok) => {
+				let (msg, stream) = ok.serialize_msg();
+				(Ok(msg), stream)
+			}
+			Err(err) => {
+				let (msg, stream) = err.serialize_msg();
+				(Err(msg), stream)
+			}
+		}
+	}
+
+	async fn deserialize_msg(ser_self: Self::SerializableSelf, stream: AssociatedStream) -> Self {
+		match ser_self {
+			Ok(ok) => Ok(T::deserialize_msg(ok, stream).await),
+			Err(err) => Err(E::deserialize_msg(err, stream).await),
 		}
-		Ok(res)
 	}
 }
 
@@ -139,7 +157,7 @@ where
 		prio: RequestPriority,
 	) -> Result<<M as Message>::Response, Error>
 	where
-		B: Borrow<M>,
+		B: Borrow<M> + Send + Sync,
 	{
 		if *target == self.netapp.id {
 			match self.handler.load_full() {
@@ -202,8 +220,8 @@ where
 		match self.0.handler.load_full() {
 			None => Err(Error::NoHandler),
 			Some(h) => {
-				let mut deser = rmp_serde::decode::Deserializer::from_read_ref(buf);
-				let req = M::deserialize_msg(&mut deser, stream).await?;
+				let req = rmp_serde::decode::from_read_ref(buf)?;
+				let req = M::deserialize_msg(req, stream).await;
 				let res = h.handle(&req, from).await;
 				let res_bytes = rmp_to_vec_all_named(&res)?;
 				Ok(res_bytes)

src/netapp.rs

@@ -32,12 +32,14 @@ pub(crate) type VersionTag = [u8; 16];
 /// Value of the Netapp version used in the version tag
 pub(crate) const NETAPP_VERSION_TAG: u64 = 0x6e65746170700004; // netapp 0x0004
 
-#[derive(Serialize, Deserialize, Debug)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub(crate) struct HelloMessage {
 	pub server_addr: Option<IpAddr>,
 	pub server_port: u16,
 }
 
+impl AutoSerialize for HelloMessage {}
+
 impl Message for HelloMessage {
 	type Response = ();
 }

src/peering/fullmesh.rs

@@ -29,7 +29,7 @@ const FAILED_PING_THRESHOLD: usize = 3;
 
 // -- Protocol messages --
 
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Clone)]
 struct PingMessage {
 	pub id: u64,
 	pub peer_list_hash: hash::Digest,
@@ -39,7 +39,9 @@ impl Message for PingMessage {
 	type Response = PingMessage;
 }
 
-#[derive(Serialize, Deserialize)]
+impl AutoSerialize for PingMessage {}
+
+#[derive(Serialize, Deserialize, Clone)]
 struct PeerListMessage {
 	pub list: Vec<(NodeID, SocketAddr)>,
 }
@@ -48,6 +50,8 @@ impl Message for PeerListMessage {
 	type Response = PeerListMessage;
 }
 
+impl AutoSerialize for PeerListMessage {}
+
 // -- Algorithm data structures --
 
 #[derive(Debug)]

src/proto.rs

@@ -151,9 +151,10 @@ impl Stream for DataReader {
 				}
 
 				let mut body = [0; MAX_CHUNK_LENGTH as usize];
-				body[..buf.len()].copy_from_slice(&buf);
+				let len = buf.len();
+				body[..len].copy_from_slice(buf);
 				buf.clear();
-				Poll::Ready(Some((body, MAX_CHUNK_LENGTH as usize)))
+				Poll::Ready(Some((body, len)))
 			}
 		}
 	}

src/util.rs

@@ -8,6 +8,8 @@ use futures::Stream;
 
 use log::info;
 
+use serde::Serialize;
+
 use tokio::sync::watch;
 
 /// A node's identifier, which is also its public cryptographic key
@@ -34,7 +36,8 @@ where
 	let mut se = rmp_serde::Serializer::new(&mut wr)
 		.with_struct_map()
 		.with_string_variants();
-	let (_, stream) = val.serialize_msg(&mut se)?;
+	let (val, stream) = val.serialize_msg();
+	val.serialize(&mut se)?;
 	Ok((wr, stream))
 }