Refactoring

src/client.rs

@@ -2,6 +2,7 @@ use std::collections::HashMap;
 use std::net::SocketAddr;
 use std::sync::atomic::{self, AtomicU32};
 use std::sync::{Arc, Mutex};
+use std::borrow::Borrow;
 
 use arc_swap::ArcSwapOption;
 use log::{debug, error, trace};
@@ -29,6 +30,7 @@ use crate::endpoint::*;
 use crate::error::*;
 use crate::netapp::*;
 use crate::proto::*;
+use crate::proto2::*;
 use crate::util::*;
 
 pub(crate) struct ClientConn {
@@ -118,14 +120,15 @@ impl ClientConn {
 		self.query_send.store(None);
 	}
 
-	pub(crate) async fn call<T>(
+	pub(crate) async fn call<'a, T, B>(
 		self: Arc<Self>,
-		rq: &T,
-		path: &str,
+		rq: B,
+		path: &'a str,
 		prio: RequestPriority,
 	) -> Result<<T as Message>::Response, Error>
 	where
 		T: Message,
+		B: Borrow<T>,
 	{
 		let query_send = self.query_send.load_full().ok_or(Error::ConnectionClosed)?;
 
@@ -147,19 +150,17 @@ impl ClientConn {
 		};
 
 		// Encode request
-		let mut bytes = vec![];
+		let body = rmp_to_vec_all_named(rq.borrow())?;
+		drop(rq);
 
-		bytes.extend_from_slice(&[prio, path.as_bytes().len() as u8]);
-		bytes.extend_from_slice(path.as_bytes());
-
-		if let Some(by) = telemetry_id {
-			bytes.push(by.len() as u8);
-			bytes.extend(by);
-		} else {
-			bytes.push(0);
-		}
-
-		bytes.extend_from_slice(&rmp_to_vec_all_named(rq)?[..]);
+		let request = QueryMessage {
+			prio,
+			path: path.as_bytes(),
+			telemetry_id,
+			body: &body[..],
+		};
+		let bytes = request.encode();
+		drop(body);
 
 		// Send request through
 		let (resp_send, resp_recv) = oneshot::channel();

src/endpoint.rs

@@ -1,5 +1,6 @@
 use std::marker::PhantomData;
 use std::sync::Arc;
+use std::borrow::Borrow;
 
 use arc_swap::ArcSwapOption;
 use async_trait::async_trait;
@@ -88,16 +89,17 @@ where
 
 	/// Call this endpoint on a remote node (or on the local node,
 	/// for that matter)
-	pub async fn call(
+	pub async fn call<B>(
 		&self,
 		target: &NodeID,
-		req: &M,
+		req: B,
 		prio: RequestPriority,
-	) -> Result<<M as Message>::Response, Error> {
+	) -> Result<<M as Message>::Response, Error> 
+	where B: Borrow<M> {
 		if *target == self.netapp.id {
 			match self.handler.load_full() {
 				None => Err(Error::NoHandler),
-				Some(h) => Ok(h.handle(req, self.netapp.id).await),
+				Some(h) => Ok(h.handle(req.borrow(), self.netapp.id).await),
 			}
 		} else {
 			let conn = self

src/lib.rs

@@ -19,6 +19,7 @@ pub mod util;
 pub mod endpoint;
 pub mod proto;
 
+mod proto2;
 mod client;
 mod server;
 

src/proto.rs

@@ -96,6 +96,14 @@ impl SendQueue {
 	}
 }
 
+/// The SendLoop trait, which is implemented both by the client and the server
+/// connection objects (ServerConna and ClientConn) adds a method `.send_loop()`
+/// that takes a channel of messages to send and an asynchronous writer,
+/// and sends messages from the channel to the async writer, putting them in a queue
+/// before being sent and doing the round-robin sending strategy.
+///
+/// The `.send_loop()` exits when the sending end of the channel is closed,
+/// or if there is an error at any time writing to the async writer.
 #[async_trait]
 pub(crate) trait SendLoop: Sync {
 	async fn send_loop<W>(
@@ -128,9 +136,9 @@ pub(crate) trait SendLoop: Sync {
 				write.write_all(&header_id[..]).await?;
 
 				if item.data.len() - item.cursor > MAX_CHUNK_LENGTH as usize {
-					let header_size =
+					let size_header =
 						ChunkLength::to_be_bytes(MAX_CHUNK_LENGTH | CHUNK_HAS_CONTINUATION);
-					write.write_all(&header_size[..]).await?;
+					write.write_all(&size_header[..]).await?;
 
 					let new_cursor = item.cursor + MAX_CHUNK_LENGTH as usize;
 					write.write_all(&item.data[item.cursor..new_cursor]).await?;
@@ -140,8 +148,8 @@ pub(crate) trait SendLoop: Sync {
 				} else {
 					let send_len = (item.data.len() - item.cursor) as ChunkLength;
 
-					let header_size = ChunkLength::to_be_bytes(send_len);
-					write.write_all(&header_size[..]).await?;
+					let size_header = ChunkLength::to_be_bytes(send_len);
+					write.write_all(&size_header[..]).await?;
 
 					write.write_all(&item.data[item.cursor..]).await?;
 				}
@@ -166,9 +174,15 @@ pub(crate) trait SendLoop: Sync {
 	}
 }
 
+/// The RecvLoop trait, which is implemented both by the client and the server
+/// connection objects (ServerConn and ClientConn) adds a method `.recv_loop()`
+/// and a prototype of a handler for received messages `.recv_handler()` that
+/// must be filled by implementors. `.recv_loop()` receives messages in a loop
+/// according to the protocol defined above: chunks of message in progress of being
+/// received are stored in a buffer, and when the last chunk of a message is received,
+/// the full message is passed to the receive handler.
 #[async_trait]
 pub(crate) trait RecvLoop: Sync + 'static {
-	// Returns true if we should stop receiving after this
 	fn recv_handler(self: &Arc<Self>, id: RequestID, msg: Vec<u8>);
 
 	async fn recv_loop<R>(self: Arc<Self>, mut read: R) -> Result<(), Error>

src/proto2.rs

@@ -0,0 +1,75 @@
+use crate::proto::*;
+use crate::error::*;
+
+pub(crate) struct QueryMessage<'a> {
+	pub(crate) prio: RequestPriority,
+	pub(crate) path: &'a [u8],
+	pub(crate) telemetry_id: Option<Vec<u8>>,
+	pub(crate) body: &'a [u8],
+}
+
+/// QueryMessage encoding:
+/// - priority: u8
+/// - path length: u8
+/// - path: [u8; path length]
+/// - telemetry id length: u8
+/// - telemetry id: [u8; telemetry id length]
+/// - body [u8; ..]
+impl<'a> QueryMessage<'a> {
+	pub(crate) fn encode(self) -> Vec<u8> {
+		let tel_len = match &self.telemetry_id {
+			Some(t) => t.len(),
+			None => 0,
+		};
+
+		let mut ret = Vec::with_capacity(10 + self.path.len() + tel_len + self.body.len());
+
+		ret.push(self.prio);
+
+		ret.push(self.path.len() as u8);
+		ret.extend_from_slice(self.path);
+
+		if let Some(t) = self.telemetry_id {
+			ret.push(t.len() as u8);
+			ret.extend(t);
+		} else {
+			ret.push(0u8);
+		}
+
+		ret.extend_from_slice(self.body);
+
+		ret
+	}
+
+	pub(crate) fn decode(bytes: &'a [u8]) -> Result<Self, Error> {
+		if bytes.len() < 3 {
+			return Err(Error::Message("Invalid protocol message".into()));
+		}
+
+		let path_length = bytes[1] as usize;
+		if bytes.len() < 3 + path_length {
+			return Err(Error::Message("Invalid protocol message".into()));
+		}
+
+		let telemetry_id_len = bytes[2 + path_length] as usize;
+		if bytes.len() < 3 + path_length + telemetry_id_len {
+			return Err(Error::Message("Invalid protocol message".into()));
+		}
+
+		let path = &bytes[2..2 + path_length];
+		let telemetry_id = if telemetry_id_len > 0 {
+			Some(bytes[3 + path_length .. 3 + path_length + telemetry_id_len].to_vec())
+		} else {
+			None
+		};
+
+		let body = &bytes[3 + path_length + telemetry_id_len..];
+
+		Ok(Self {
+			prio: bytes[0],
+			path,
+			telemetry_id,
+			body,
+		})
+	}
+}

src/server.rs

@@ -29,6 +29,7 @@ use kuska_handshake::async_std::{handshake_server, BoxStream};
 use crate::error::*;
 use crate::netapp::*;
 use crate::proto::*;
+use crate::proto2::*;
 use crate::util::*;
 
 // The client and server connection structs (client.rs and server.rs)
@@ -116,22 +117,8 @@ impl ServerConn {
 	}
 
 	async fn recv_handler_aux(self: &Arc<Self>, bytes: &[u8]) -> Result<Vec<u8>, Error> {
-		if bytes.len() < 2 {
-			return Err(Error::Message("Invalid protocol message".into()));
-		}
-
-		// byte 0 is the request priority, we don't care here
-		let path_length = bytes[1] as usize;
-		if bytes.len() < 2 + path_length {
-			return Err(Error::Message("Invalid protocol message".into()));
-		}
-
-		let path = &bytes[2..2 + path_length];
-		let path = String::from_utf8(path.to_vec())?;
-
-		let telemetry_id_len = bytes[2 + path_length] as usize;
-
-		let data = &bytes[3 + path_length + telemetry_id_len..];
+		let msg = QueryMessage::decode(bytes)?;
+		let path = String::from_utf8(msg.path.to_vec())?;
 
 		let handler_opt = {
 			let endpoints = self.netapp.endpoints.read().unwrap();
@@ -143,10 +130,9 @@ impl ServerConn {
 				if #[cfg(feature = "telemetry")] {
 					let tracer = opentelemetry::global::tracer("netapp");
 
-					let mut span = if telemetry_id_len > 0 {
-						let by = bytes[3+path_length..3+path_length+telemetry_id_len].to_vec();
+					let mut span = if let Some(telemetry_id) = msg.telemetry_id {
 						let propagator = BinaryPropagator::new();
-						let context = propagator.from_bytes(by);
+						let context = propagator.from_bytes(telemetry_id);
 						let context = Context::new().with_remote_span_context(context);
 						tracer.span_builder(format!(">> RPC {}", path))
 							.with_kind(SpanKind::Server)
@@ -161,13 +147,13 @@ impl ServerConn {
 							.start(&tracer)
 					};
 					span.set_attribute(KeyValue::new("path", path.to_string()));
-					span.set_attribute(KeyValue::new("len_query", data.len() as i64));
+					span.set_attribute(KeyValue::new("len_query", msg.body.len() as i64));
 
-					handler.handle(data, self.peer_id)
+					handler.handle(msg.body, self.peer_id)
 						.with_context(Context::current_with_span(span))
 						.await
 				} else {
-					handler.handle(data, self.peer_id).await
+					handler.handle(msg.body, self.peer_id).await
 				}
 			}
 		} else {
@@ -191,16 +177,16 @@ impl RecvLoop for ServerConn {
 			let prio = if !bytes.is_empty() { bytes[0] } else { 0u8 };
 			let resp = self2.recv_handler_aux(&bytes[..]).await;
 
-			let mut resp_bytes = vec![];
-			match resp {
+			let resp_bytes = match resp {
 				Ok(rb) => {
-					resp_bytes.push(0u8);
-					resp_bytes.extend(&rb[..]);
+					let mut resp_bytes = vec![0u8];
+					resp_bytes.extend(rb);
+					resp_bytes
 				}
 				Err(e) => {
-					resp_bytes.push(e.code());
-				}
+					vec![e.code()]
 				}
+			};
 
 			trace!("ServerConn sending response to {}: ", id);