Add dump of sending queue

src/proto.rs

@@ -1,5 +1,6 @@
 use std::collections::{HashMap, VecDeque};
 use std::sync::Arc;
+use std::fmt::Write;
 
 use log::trace;
 
@@ -94,6 +95,15 @@ impl SendQueue {
 	fn is_empty(&self) -> bool {
 		self.items.iter().all(|(_k, v)| v.is_empty())
 	}
+	fn dump(&self) -> String {
+		let mut ret = String::new();
+		for (prio, q) in self.items.iter() {
+			for item in q.iter() {
+				write!(&mut ret, " [{} {} ({})]", prio, item.data.len() - item.cursor, item.id).unwrap();
+			}
+		}
+		ret
+	}
 }
 
 /// The SendLoop trait, which is implemented both by the client and the server
@@ -117,6 +127,7 @@ pub(crate) trait SendLoop: Sync {
 		let mut sending = SendQueue::new();
 		let mut should_exit = false;
 		while !should_exit || !sending.is_empty() {
+			trace!("send_loop: queue = {}", sending.dump());
 			if let Ok((id, prio, data)) = msg_recv.try_recv() {
 				trace!("send_loop: got {}, {} bytes", id, data.len());
 				sending.push(SendQueueItem {