Squashed 'livekit-server/' content from commit 154b4d26

git-subtree-dir: livekit-server
git-subtree-split: 154b4d26b769c68a03c096124094b97bf61a996f

pkg/rtc/medialossproxy.go

@@ -0,0 +1,105 @@
+// Copyright 2023 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rtc
+
+import (
+	"sync"
+	"time"
+
+	"github.com/pion/rtcp"
+
+	"github.com/livekit/protocol/livekit"
+	"github.com/livekit/protocol/logger"
+
+	"github.com/livekit/livekit-server/pkg/sfu"
+)
+
+const (
+	downLostUpdateDelta = time.Second
+)
+
+type MediaLossProxyParams struct {
+	Logger logger.Logger
+}
+
+type MediaLossProxy struct {
+	params MediaLossProxyParams
+
+	lock                 sync.Mutex
+	maxDownFracLost      uint8
+	maxDownFracLostTs    time.Time
+	maxDownFracLostValid bool
+
+	onMediaLossUpdate func(fractionalLoss uint8)
+}
+
+func NewMediaLossProxy(params MediaLossProxyParams) *MediaLossProxy {
+	return &MediaLossProxy{params: params}
+}
+
+func (m *MediaLossProxy) OnMediaLossUpdate(f func(fractionalLoss uint8)) {
+	m.lock.Lock()
+	m.onMediaLossUpdate = f
+	m.lock.Unlock()
+}
+
+func (m *MediaLossProxy) HandleMaxLossFeedback(_ *sfu.DownTrack, report *rtcp.ReceiverReport) {
+	m.lock.Lock()
+	for _, rr := range report.Reports {
+		m.maxDownFracLostValid = true
+		if m.maxDownFracLost < rr.FractionLost {
+			m.maxDownFracLost = rr.FractionLost
+		}
+	}
+	m.lock.Unlock()
+
+	m.maybeUpdateLoss()
+}
+
+func (m *MediaLossProxy) NotifySubscriberNodeMediaLoss(_nodeID livekit.NodeID, fractionalLoss uint8) {
+	m.lock.Lock()
+	m.maxDownFracLostValid = true
+	if m.maxDownFracLost < fractionalLoss {
+		m.maxDownFracLost = fractionalLoss
+	}
+	m.lock.Unlock()
+
+	m.maybeUpdateLoss()
+}
+
+func (m *MediaLossProxy) maybeUpdateLoss() {
+	var (
+		shouldUpdate bool
+		maxLost      uint8
+	)
+
+	m.lock.Lock()
+	now := time.Now()
+	if now.Sub(m.maxDownFracLostTs) > downLostUpdateDelta && m.maxDownFracLostValid {
+		shouldUpdate = true
+		maxLost = m.maxDownFracLost
+		m.maxDownFracLost = 0
+		m.maxDownFracLostTs = now
+		m.maxDownFracLostValid = false
+	}
+	onMediaLossUpdate := m.onMediaLossUpdate
+	m.lock.Unlock()
+
+	if shouldUpdate {
+		if onMediaLossUpdate != nil {
+			onMediaLossUpdate(maxLost)
+		}
+	}
+}