From 86b6c71ca0c9387775834cdf52058e54e6bf740b Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Fri, 7 May 2021 02:23:10 +0200
Subject: [PATCH] Reformat stats display, protect against division by zero.

---
 rtpconn/rtpstats.go    |  7 +++++--
 static/stats.js        | 35 ++++++++++++++++++++---------------
 webserver/webserver.go |  5 ++++-
 3 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/rtpconn/rtpstats.go b/rtpconn/rtpstats.go
index e7975bd..16e934b 100644
--- a/rtpconn/rtpstats.go
+++ b/rtpconn/rtpstats.go
@@ -23,8 +23,11 @@ func (c *webClient) GetStats() *stats.Client {
 		tracks := up.getTracks()
 		for _, t := range tracks {
 			s := t.cache.GetStats(false)
-			loss :=  float64(s.Expected - s.Received) /
-				float64(s.Expected)
+			var loss float64
+			if s.Expected > 0 {
+				loss = float64(s.Expected-s.Received) /
+					float64(s.Expected)
+			}
 			jitter := time.Duration(t.jitter.Jitter()) *
 				(time.Second / time.Duration(t.jitter.HZ()))
 			rate, _ := t.rate.Estimate()
diff --git a/static/stats.js b/static/stats.js
index 31c5fa0..25dc692 100644
--- a/static/stats.js
+++ b/static/stats.js
@@ -56,11 +56,15 @@ function formatGroup(group) {
             tr2.appendChild(td3);
             table.appendChild(tr2);
             if(client.up)
-                for(let j = 0; j < client.up.length; j++)
-                    table.appendChild(formatConn('↑', client.up[j]));
+                for(let j = 0; j < client.up.length; j++) {
+                    let rows = formatConn('↑', client.up[j]);
+                    rows.forEach(r => table.appendChild(r));
+                }
             if(client.down)
-                for(let j = 0; j < client.down.length; j++)
-                    table.appendChild(formatConn('↓', client.down[j]));
+                for(let j = 0; j < client.down.length; j++) {
+                    let rows = formatConn('↓', client.down[j]);
+                    rows.forEach(r => table.appendChild(r));
+                }
         }
         td2.appendChild(table);
         tr.appendChild(td2);
@@ -76,24 +80,25 @@ function formatConn(direction, conn) {
     td2.textContent = conn.id;
     tr.appendChild(td2);
     let td3 = document.createElement('td');
-    if(conn.maxBitrate)
-        td3.textContent = direction + ' ' + conn.maxBitrate;
-    else
-        td3.textContent = direction;
+    td3.textContent = direction;
     tr.appendChild(td3);
     let td4 = document.createElement('td');
-    if(conn.tracks) {
-        let table = document.createElement('table');
-        for(let i = 0; i < conn.tracks.length; i++)
-            table.appendChild(formatTrack(conn.tracks[i]));
-        td4.appendChild(table);
-    }
+    if(conn.maxBitrate)
+        td4.textContent = `${conn.maxBitrate}`;
     tr.appendChild(td4);
-    return tr;
+    let rows = [tr];
+    if(conn.tracks) {
+        for(let i = 0; i < conn.tracks.length; i++)
+            rows.push(formatTrack(conn.tracks[i]));
+    }
+    return rows;
 }
 
 function formatTrack(track) {
     let tr = document.createElement('tr');
+    tr.appendChild(document.createElement('td'));
+    tr.appendChild(document.createElement('td'));
+    tr.appendChild(document.createElement('td'));
     let td = document.createElement('td');
     if(track.maxBitrate)
         td.textContent = `${track.bitrate||0}/${track.maxBitrate}`;
diff --git a/webserver/webserver.go b/webserver/webserver.go
index 805fc0e..36348bc 100644
--- a/webserver/webserver.go
+++ b/webserver/webserver.go
@@ -370,7 +370,10 @@ func statsHandler(w http.ResponseWriter, r *http.Request, dataDir string) {
 
 	ss := stats.GetGroups()
 	e := json.NewEncoder(w)
-	e.Encode(ss)
+	err = e.Encode(ss)
+	if err != nil {
+		log.Printf("stats.json: %v", err)
+	}
 	return
 }