Merge pull request 'add streaming body to requests and responses' (#3) from stream-body into mainv0.5.0

Reviewed-on: https://git.deuxfleurs.fr/lx/netapp/pulls/3

1 files changed, 70 insertions, 36 deletions

diff --git a/src/endpoint.rs b/src/endpoint.rs
index 42e9a98..3cafafe 100644
--- a/src/endpoint.rs
+++ b/src/endpoint.rs
@@ -1,33 +1,25 @@
-use std::borrow::Borrow;
 use std::marker::PhantomData;
 use std::sync::Arc;
 
 use arc_swap::ArcSwapOption;
 use async_trait::async_trait;
 
-use serde::{Deserialize, Serialize};
-
 use crate::error::Error;
+use crate::message::*;
 use crate::netapp::*;
-use crate::proto::*;
-use crate::util::*;
-
-/// This trait should be implemented by all messages your application
-/// wants to handle
-pub trait Message: Serialize + for<'de> Deserialize<'de> + Send + Sync {
-	type Response: Serialize + for<'de> Deserialize<'de> + Send + Sync;
-}
 
 /// This trait should be implemented by an object of your application
-/// that can handle a message of type `M`.
+/// that can handle a message of type `M`, if it wishes to handle
+/// streams attached to the request and/or to send back streams
+/// attached to the response..
 ///
 /// The handler object should be in an Arc, see `Endpoint::set_handler`
 #[async_trait]
-pub trait EndpointHandler<M>: Send + Sync
+pub trait StreamingEndpointHandler<M>: Send + Sync
 where
 	M: Message,
 {
-	async fn handle(self: &Arc<Self>, m: &M, from: NodeID) -> M::Response;
+	async fn handle(self: &Arc<Self>, m: Req<M>, from: NodeID) -> Resp<M>;
 }
 
 /// If one simply wants to use an endpoint in a client fashion,
@@ -35,12 +27,41 @@ where
 /// use the unit type `()` as the handler type:
 /// it will panic if it is ever made to handle request.
 #[async_trait]
-impl<M: Message + 'static> EndpointHandler<M> for () {
+impl<M: Message> EndpointHandler<M> for () {
 	async fn handle(self: &Arc<()>, _m: &M, _from: NodeID) -> M::Response {
 		panic!("This endpoint should not have a local handler.");
 	}
 }
 
+// ----
+
+/// This trait should be implemented by an object of your application
+/// that can handle a message of type `M`, in the cases where it doesn't
+/// care about attached stream in the request nor in the response.
+#[async_trait]
+pub trait EndpointHandler<M>: Send + Sync
+where
+	M: Message,
+{
+	async fn handle(self: &Arc<Self>, m: &M, from: NodeID) -> M::Response;
+}
+
+#[async_trait]
+impl<T, M> StreamingEndpointHandler<M> for T
+where
+	T: EndpointHandler<M>,
+	M: Message,
+{
+	async fn handle(self: &Arc<Self>, mut m: Req<M>, from: NodeID) -> Resp<M> {
+		// Immediately drop stream to ignore all data that comes in,
+		// instead of buffering it indefinitely
+		drop(m.take_stream());
+		Resp::new(EndpointHandler::handle(self, m.msg(), from).await)
+	}
+}
+
+// ----
+
 /// This struct represents an endpoint for message of type `M`.
 ///
 /// Creating a new endpoint is done by calling `NetApp::endpoint`.
@@ -50,13 +71,13 @@ impl<M: Message + 'static> EndpointHandler<M> for () {
 /// An `Endpoint` is used both to send requests to remote nodes,
 /// and to specify the handler for such requests on the local node.
 /// The type `H` represents the type of the handler object for
-/// endpoint messages (see `EndpointHandler`).
+/// endpoint messages (see `StreamingEndpointHandler`).
 pub struct Endpoint<M, H>
 where
 	M: Message,
-	H: EndpointHandler<M>,
+	H: StreamingEndpointHandler<M>,
 {
-	phantom: PhantomData<M>,
+	_phantom: PhantomData<M>,
 	netapp: Arc<NetApp>,
 	path: String,
 	handler: ArcSwapOption<H>,
@@ -65,11 +86,11 @@ where
 impl<M, H> Endpoint<M, H>
 where
 	M: Message,
-	H: EndpointHandler<M>,
+	H: StreamingEndpointHandler<M>,
 {
 	pub(crate) fn new(netapp: Arc<NetApp>, path: String) -> Self {
 		Self {
-			phantom: PhantomData::default(),
+			_phantom: PhantomData::default(),
 			netapp,
 			path,
 			handler: ArcSwapOption::from(None),
@@ -88,20 +109,22 @@ where
 	}
 
 	/// Call this endpoint on a remote node (or on the local node,
-	/// for that matter)
-	pub async fn call<B>(
+	/// for that matter). This function invokes the full version that
+	/// allows to attach a stream to the request and to
+	/// receive such a stream attached to the response.
+	pub async fn call_streaming<T>(
 		&self,
 		target: &NodeID,
-		req: B,
+		req: T,
 		prio: RequestPriority,
-	) -> Result<<M as Message>::Response, Error>
+	) -> Result<Resp<M>, Error>
 	where
-		B: Borrow<M>,
+		T: IntoReq<M>,
 	{
 		if *target == self.netapp.id {
 			match self.handler.load_full() {
 				None => Err(Error::NoHandler),
-				Some(h) => Ok(h.handle(req.borrow(), self.netapp.id).await),
+				Some(h) => Ok(h.handle(req.into_req_local(), self.netapp.id).await),
 			}
 		} else {
 			let conn = self
@@ -116,10 +139,22 @@ where
 					"Not connected: {}",
 					hex::encode(&target[..8])
 				))),
-				Some(c) => c.call(req, self.path.as_str(), prio).await,
+				Some(c) => c.call(req.into_req()?, self.path.as_str(), prio).await,
 			}
 		}
 	}
+
+	/// Call this endpoint on a remote node. This function is the simplified
+	/// version that doesn't allow to have streams attached to the request
+	/// or the response; see `call_streaming` for the full version.
+	pub async fn call(
+		&self,
+		target: &NodeID,
+		req: M,
+		prio: RequestPriority,
+	) -> Result<<M as Message>::Response, Error> {
+		Ok(self.call_streaming(target, req, prio).await?.into_msg())
+	}
 }
 
 // ---- Internal stuff ----
@@ -128,7 +163,7 @@ pub(crate) type DynEndpoint = Box<dyn GenericEndpoint + Send + Sync>;
 
 #[async_trait]
 pub(crate) trait GenericEndpoint {
-	async fn handle(&self, buf: &[u8], from: NodeID) -> Result<Vec<u8>, Error>;
+	async fn handle(&self, req_enc: ReqEnc, from: NodeID) -> Result<RespEnc, Error>;
 	fn drop_handler(&self);
 	fn clone_endpoint(&self) -> DynEndpoint;
 }
@@ -137,22 +172,21 @@ pub(crate) trait GenericEndpoint {
 pub(crate) struct EndpointArc<M, H>(pub(crate) Arc<Endpoint<M, H>>)
 where
 	M: Message,
-	H: EndpointHandler<M>;
+	H: StreamingEndpointHandler<M>;
 
 #[async_trait]
 impl<M, H> GenericEndpoint for EndpointArc<M, H>
 where
-	M: Message + 'static,
-	H: EndpointHandler<M> + 'static,
+	M: Message,
+	H: StreamingEndpointHandler<M> + 'static,
 {
-	async fn handle(&self, buf: &[u8], from: NodeID) -> Result<Vec<u8>, Error> {
+	async fn handle(&self, req_enc: ReqEnc, from: NodeID) -> Result<RespEnc, Error> {
 		match self.0.handler.load_full() {
 			None => Err(Error::NoHandler),
 			Some(h) => {
-				let req = rmp_serde::decode::from_read_ref::<_, M>(buf)?;
-				let res = h.handle(&req, from).await;
-				let res_bytes = rmp_to_vec_all_named(&res)?;
-				Ok(res_bytes)
+				let req = Req::from_enc(req_enc)?;
+				let res = h.handle(req, from).await;
+				Ok(res.into_enc()?)
 			}
 		}
 	}