src/client.rs

@@ -190,7 +190,7 @@ impl ClientConn {
 		#[cfg(feature = "telemetry")]
 		span.set_attribute(KeyValue::new("len_query_msg", req_msg_len as i64));
 
-		query_send.send((id, prio, req_stream))?;
+		query_send.send((id, prio, req_order, req_stream))?;
 
 		cfg_if::cfg_if! {
 			if #[cfg(feature = "telemetry")] {

src/message.rs

@@ -44,7 +44,7 @@ pub const PRIO_SECONDARY: RequestPriority = 0x01;
 #[derive(Clone, Copy)]
 pub struct OrderTagStream(u64);
 #[derive(Clone, Copy, Serialize, Deserialize, Debug)]
-pub struct OrderTag(u64, u64);
+pub struct OrderTag(pub(crate) u64, pub(crate) u64);
 
 impl OrderTag {
 	pub fn stream() -> OrderTagStream {

src/send.rs

@@ -1,4 +1,4 @@
-use std::collections::VecDeque;
+use std::collections::{HashMap, VecDeque};
 use std::pin::Pin;
 use std::sync::Arc;
 use std::task::{Context, Poll};
@@ -7,7 +7,7 @@ use async_trait::async_trait;
 use bytes::{BufMut, Bytes, BytesMut};
 use log::*;
 
-use futures::AsyncWriteExt;
+use futures::{AsyncWriteExt, Future};
 use kuska_handshake::async_std::BoxStreamWrite;
 use tokio::sync::mpsc;
 
@@ -36,15 +36,21 @@ pub(crate) const ERROR_MARKER: ChunkLength = 0x4000;
 pub(crate) const CHUNK_HAS_CONTINUATION: ChunkLength = 0x8000;
 pub(crate) const CHUNK_LENGTH_MASK: ChunkLength = 0x3FFF;
 
-pub(crate) type SendStream = (RequestID, RequestPriority, ByteStream);
+pub(crate) type SendStream = (RequestID, RequestPriority, Option<OrderTag>, ByteStream);
 
 struct SendQueue {
-	items: Vec<(u8, VecDeque<SendQueueItem>)>,
+	items: Vec<(u8, SendQueuePriority)>,
+}
+
+struct SendQueuePriority {
+	items: VecDeque<SendQueueItem>,
+	order: HashMap<u64, VecDeque<u64>>,
 }
 
 struct SendQueueItem {
 	id: RequestID,
 	prio: RequestPriority,
+	order_tag: Option<OrderTag>,
 	data: ByteStreamReader,
 }
 
@@ -59,11 +65,11 @@ impl SendQueue {
 		let pos_prio = match self.items.binary_search_by(|(p, _)| p.cmp(&prio)) {
 			Ok(i) => i,
 			Err(i) => {
-				self.items.insert(i, (prio, VecDeque::new()));
+				self.items.insert(i, (prio, SendQueuePriority::new()));
 				i
 			}
 		};
-		self.items[pos_prio].1.push_back(item);
+		self.items[pos_prio].1.push(item);
 	}
 	fn is_empty(&self) -> bool {
 		self.items.iter().all(|(_k, v)| v.is_empty())
@@ -75,6 +81,69 @@ impl SendQueue {
 	}
 }
 
+impl SendQueuePriority {
+	fn new() -> Self {
+		Self {
+			items: VecDeque::new(),
+			order: HashMap::new(),
+		}
+	}
+	fn push(&mut self, item: SendQueueItem) {
+		if let Some(OrderTag(stream, order)) = item.order_tag {
+			let order_vec = self.order.entry(stream).or_default();
+			let i = order_vec.iter().take_while(|o2| **o2 < order).count();
+			order_vec.insert(i, order);
+		}
+		self.items.push_back(item);
+	}
+	fn is_empty(&self) -> bool {
+		self.items.is_empty()
+	}
+	fn poll_next_ready(&mut self, ctx: &mut Context<'_>) -> Poll<(RequestID, DataFrame)> {
+		for (j, item) in self.items.iter_mut().enumerate() {
+			if let Some(OrderTag(stream, order)) = item.order_tag {
+				if order > *self.order.get(&stream).unwrap().front().unwrap() {
+					continue;
+				}
+			}
+
+			let mut item_reader = item.data.read_exact_or_eos(MAX_CHUNK_LENGTH as usize);
+			if let Poll::Ready(bytes_or_err) = Pin::new(&mut item_reader).poll(ctx) {
+				let id = item.id;
+				let eos = item.data.eos();
+
+				let packet = bytes_or_err.map_err(|e| match e {
+					ReadExactError::Stream(err) => err,
+					_ => unreachable!(),
+				});
+
+				if eos || packet.is_err() {
+					if let Some(OrderTag(stream, order)) = item.order_tag {
+						assert_eq!(
+							self.order.get_mut(&stream).unwrap().pop_front(),
+							Some(order)
+						)
+					}
+					self.items.remove(j);
+				}
+
+				let data_frame = DataFrame::from_packet(packet, !eos);
+
+				return Poll::Ready((id, data_frame));
+			}
+		}
+
+		Poll::Pending
+	}
+	fn dump(&self, prio: u8) -> String {
+		self.items
+			.iter()
+			.map(|i| format!("[{} {} {:?}]", prio, i.id, i.order_tag))
+			.collect::<Vec<_>>()
+			.join(" ")
+	}
+}
+
 struct SendQueuePollNextReady<'a> {
 	queue: &'a mut SendQueue,
 }
@@ -84,37 +153,11 @@ impl<'a> futures::Future for SendQueuePollNextReady<'a> {
 
 	fn poll(mut self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<Self::Output> {
 		for (i, (_prio, items_at_prio)) in self.queue.items.iter_mut().enumerate() {
-			let mut ready_item = None;
+			if let Poll::Ready(res) = items_at_prio.poll_next_ready(ctx) {
-			for (j, item) in items_at_prio.iter_mut().enumerate() {
+				if items_at_prio.is_empty() {
-				let mut item_reader = item.data.read_exact_or_eos(MAX_CHUNK_LENGTH as usize);
-				match Pin::new(&mut item_reader).poll(ctx) {
-					Poll::Pending => (),
-					Poll::Ready(ready_v) => {
-						ready_item = Some((j, ready_v));
-						break;
-					}
-				}
-			}
-
-			if let Some((j, bytes_or_err)) = ready_item {
-				let item = items_at_prio.remove(j).unwrap();
-				let id = item.id;
-				let eos = item.data.eos();
-
-				let packet = bytes_or_err.map_err(|e| match e {
-					ReadExactError::Stream(err) => err,
-					_ => unreachable!(),
-				});
-
-				let data_frame = DataFrame::from_packet(packet, !eos);
-
-				if !eos && !matches!(data_frame, DataFrame::Error(_)) {
-					items_at_prio.push_back(item);
-				} else if items_at_prio.is_empty() {
 					self.queue.items.remove(i);
 				}
-
+				return Poll::Ready(res);
-				return Poll::Ready((id, data_frame));
 			}
 		}
 		// If the queue is empty, this futures is eternally pending.
@@ -200,8 +243,7 @@ pub(crate) trait SendLoop: Sync {
 				sending
 					.items
 					.iter()
-					.map(|(_, i)| i.iter().map(|x| x.id))
+					.map(|(prio, i)| i.dump(*prio))
-					.flatten()
 					.collect::<Vec<_>>()
 			);
 
@@ -217,12 +259,14 @@ pub(crate) trait SendLoop: Sync {
 			// recv_fut is cancellation-safe according to tokio doc,
 			// send_fut is cancellation-safe as implemented above?
 			tokio::select! {
+				biased;	// always read incomming channel first if it has data
 				sth = recv_fut => {
-					if let Some((id, prio, data)) = sth {
+					if let Some((id, prio, order_tag, data)) = sth {
 						trace!("send_loop: add stream {} to send", id);
 						sending.push(SendQueueItem {
 							id,
 							prio,
+							order_tag,
 							data: ByteStreamReader::new(data),
 						});
 					} else {

src/server.rs

@@ -186,7 +186,7 @@ impl RecvLoop for ServerConn {
 
 			let (resp_stream, resp_order) = RespEnc::encode(resp_enc_result);
 			resp_send
-				.send((id, prio, resp_stream))
+				.send((id, prio, resp_order, resp_stream))
 				.log_err("ServerConn recv_handler send resp bytes");
 			Ok::<_, Error>(())
 		});