Add additional metrics for lost packets and bytes

quinn-proto/src/connection/mod.rs

@@ -1370,7 +1370,13 @@ impl Connection {
             let old_bytes_in_flight = self.in_flight.bytes;
             let largest_lost_sent = self.spaces[pn_space].sent_packets[&largest_lost].time_sent;
             self.lost_packets += lost_packets.len() as u64;
-            trace!("packets lost: {:?}", lost_packets);
+            self.stats.path.lost_packets += lost_packets.len() as u64;
+            self.stats.path.lost_bytes += size_of_lost_packets as u64;
+            trace!(
+                "packets lost: {:?}, bytes lost: {}",
+                lost_packets,
+                size_of_lost_packets
+            );
             for packet in &lost_packets {
                 let info = self.spaces[pn_space].sent_packets.remove(packet).unwrap(); // safe: lost_packets is populated just above
                 self.remove_in_flight(pn_space, &info);

quinn-proto/src/connection/packet_builder.rs

@@ -188,6 +188,7 @@ impl PacketBuilder {
 
         conn.in_flight.insert(&packet);
         conn.spaces[space_id].sent(exact_number, packet);
+        conn.stats.path.sent_packets += 1;
         conn.reset_keep_alive(now);
         if size != 0 {
             if ack_eliciting {

quinn-proto/src/connection/stats.rs

@@ -126,6 +126,12 @@ pub struct PathStats {
     pub cwnd: u64,
     /// Congestion events on the connection
     pub congestion_events: u64,
+    /// The amount of packets lost on this path
+    pub lost_packets: u64,
+    /// The amount of bytes lost on this path
+    pub lost_bytes: u64,
+    /// The amount of packets sent on this path
+    pub sent_packets: u64,
 }
 
 /// Connection statistics