From 634bad14d976c7160e0db6ce7053a445da15031e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Torjus=20H=C3=A5kestad?= <torjus@usit.uio.no>
Date: Wed, 6 Dec 2023 00:08:14 +0100
Subject: [PATCH] Add viewcount to stream list endpoint

---
 go.mod              |  2 +-
 ministream-frontend |  2 +-
 server/server.go    | 13 +++++++++++--
 server/stream.go    | 16 +++++++++++++---
 4 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/go.mod b/go.mod
index 4488ff9..013cb95 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.21.3
 
 require (
 	github.com/go-chi/chi/v5 v5.0.10
+	github.com/google/uuid v1.4.0
 	github.com/pelletier/go-toml/v2 v2.1.0
 	github.com/pion/interceptor v0.1.25
 	github.com/pion/sdp/v3 v3.0.6
@@ -15,7 +16,6 @@ require (
 require (
 	github.com/cpuguy83/go-md2man/v2 v2.0.3 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/google/uuid v1.4.0 // indirect
 	github.com/pion/datachannel v1.5.5 // indirect
 	github.com/pion/dtls/v2 v2.2.8 // indirect
 	github.com/pion/ice/v3 v3.0.2 // indirect
diff --git a/ministream-frontend b/ministream-frontend
index 717790c..ccbc8de 160000
--- a/ministream-frontend
+++ b/ministream-frontend
@@ -1 +1 @@
-Subproject commit 717790cb97390295e94d832fb8bc9cc83314812a
+Subproject commit ccbc8de04d35c3b1317a1e421538e630bbab1b82
diff --git a/server/server.go b/server/server.go
index 653af4e..1d54f5a 100644
--- a/server/server.go
+++ b/server/server.go
@@ -136,9 +136,18 @@ func (s *Server) DeleteHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) ListHandler(w http.ResponseWriter, r *http.Request) {
-	streams := s.streams.List()
+	type StreamInfo struct {
+		StreamKey string `json:"streamKey"`
+		ViewCount int    `json:"viewCount"`
+	}
+
+	infos := []StreamInfo{}
+	for key, stream := range s.streams.Streams {
+		infos = append(infos, StreamInfo{StreamKey: key, ViewCount: len(stream.viewers)})
+	}
+
 	enc := json.NewEncoder(w)
-	enc.Encode(&streams)
+	enc.Encode(&infos)
 }
 
 func (s *Server) WhipHandler(w http.ResponseWriter, r *http.Request) {
diff --git a/server/stream.go b/server/stream.go
index 6337791..3b54083 100644
--- a/server/stream.go
+++ b/server/stream.go
@@ -10,6 +10,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/google/uuid"
 	"github.com/pion/interceptor"
 	"github.com/pion/interceptor/pkg/nack"
 	"github.com/pion/interceptor/pkg/stats"
@@ -42,7 +43,7 @@ type Stream struct {
 	peerConnectionStatsMu sync.Mutex
 	lastUpdate            time.Time
 	localTracks           []*webrtc.TrackLocalStaticRTP
-	peers                 []*webrtc.PeerConnection
+	viewers               map[string]*webrtc.PeerConnection
 	mu                    sync.Mutex
 }
 
@@ -72,6 +73,7 @@ func (s *StreamStore) StatsHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Stream) AddListener(sd *webrtc.SessionDescription) (*webrtc.SessionDescription, error) {
+	viewerID := uuid.New().String()
 	m := &webrtc.MediaEngine{}
 	if err := m.RegisterDefaultCodecs(); err != nil {
 		panic(err)
@@ -124,6 +126,10 @@ func (s *Stream) AddListener(sd *webrtc.SessionDescription) (*webrtc.SessionDesc
 		rtpSender, err := peerConnection.AddTrack(ltrack)
 		if err != nil {
 			// TODO, stop peerconn
+			peerConnection.Close()
+			s.mu.Lock()
+			delete(s.viewers, viewerID)
+			s.mu.Unlock()
 			return nil, err
 		}
 		go func() {
@@ -131,6 +137,9 @@ func (s *Stream) AddListener(sd *webrtc.SessionDescription) (*webrtc.SessionDesc
 			for {
 				if _, _, err := rtpSender.Read(rtcpBuf); err != nil {
 					peerConnection.Close()
+					s.mu.Lock()
+					delete(s.viewers, viewerID)
+					s.mu.Unlock()
 					return
 				}
 			}
@@ -173,7 +182,7 @@ func (s *Stream) AddListener(sd *webrtc.SessionDescription) (*webrtc.SessionDesc
 	// in a production application you should exchange ICE Candidates via OnICECandidate
 	<-gatherComplete
 	s.mu.Lock()
-	s.peers = append(s.peers, peerConnection)
+	s.viewers[viewerID] = peerConnection
 
 	defer s.mu.Unlock()
 
@@ -189,6 +198,7 @@ func (s *StreamStore) Add(streamKey string, sd *webrtc.SessionDescription) (*web
 			store:               s,
 			lastUpdate:          time.Now(),
 			peerConnectionStats: make(map[string]*stats.Stats),
+			viewers:             make(map[string]*webrtc.PeerConnection),
 		}
 		m := &webrtc.MediaEngine{}
 		if err := m.RegisterDefaultCodecs(); err != nil {
@@ -391,7 +401,7 @@ func (s *StreamStore) Delete(streamKey string) error {
 	defer s.mu.Unlock()
 	delete(s.Streams, streamKey)
 
-	for _, peer := range stream.peers {
+	for _, peer := range stream.viewers {
 		if err := peer.Close(); err != nil {
 			slog.Warn("Error closing peer.", "error", err)
 		}