From d9910ead61be1c46d016ecc97060199739a101b0 Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Mon, 27 May 2024 13:43:20 +0530
Subject: [PATCH] Add back TrafficStats used by cloud. (#2736)

---
 pkg/rtc/types/trafficstats.go | 161 ++++++++++++++++++++++++++++++++++
 1 file changed, 161 insertions(+)
 create mode 100644 pkg/rtc/types/trafficstats.go

diff --git a/pkg/rtc/types/trafficstats.go b/pkg/rtc/types/trafficstats.go
new file mode 100644
index 000000000..f5c0b386d
--- /dev/null
+++ b/pkg/rtc/types/trafficstats.go
@@ -0,0 +1,161 @@
+// 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 types
+
+import (
+	"time"
+
+	"github.com/livekit/protocol/livekit"
+)
+
+type TrafficStats struct {
+	StartTime         time.Time
+	EndTime           time.Time
+	Packets           uint32
+	PacketsLost       uint32
+	PacketsPadding    uint32
+	PacketsOutOfOrder uint32
+	Bytes             uint64
+}
+
+type TrafficTypeStats struct {
+	TrackType    livekit.TrackType
+	StreamType   livekit.StreamType
+	TrafficStats *TrafficStats
+}
+
+type TrafficLoad struct {
+	TrafficTypeStats []*TrafficTypeStats
+}
+
+func RTPStatsDiffToTrafficStats(before, after *livekit.RTPStats) *TrafficStats {
+	if after == nil {
+		return nil
+	}
+
+	startTime := after.StartTime
+	if before != nil {
+		startTime = before.EndTime
+	}
+
+	getAfter := func() *TrafficStats {
+		return &TrafficStats{
+			StartTime:         startTime.AsTime(),
+			EndTime:           after.EndTime.AsTime(),
+			Packets:           after.Packets,
+			PacketsLost:       after.PacketsLost,
+			PacketsPadding:    after.PacketsPadding,
+			PacketsOutOfOrder: after.PacketsOutOfOrder,
+			Bytes:             after.Bytes + after.BytesDuplicate + after.BytesPadding,
+		}
+	}
+
+	if before == nil {
+		return getAfter()
+	}
+
+	if (after.Packets - before.Packets) > (1 << 31) {
+		// after packets < before packets, probably got reset, just return after
+		return getAfter()
+	}
+	if ((after.Bytes + after.BytesDuplicate + after.BytesPadding) - (before.Bytes + before.BytesDuplicate + before.BytesPadding)) > (1 << 63) {
+		// after bytes < before bytes, probably got reset, just return after
+		return getAfter()
+	}
+
+	packetsLost := uint32(0)
+	if after.PacketsLost >= before.PacketsLost {
+		packetsLost = after.PacketsLost - before.PacketsLost
+	}
+	return &TrafficStats{
+		StartTime:         startTime.AsTime(),
+		EndTime:           after.EndTime.AsTime(),
+		Packets:           after.Packets - before.Packets,
+		PacketsLost:       packetsLost,
+		PacketsPadding:    after.PacketsPadding - before.PacketsPadding,
+		PacketsOutOfOrder: after.PacketsOutOfOrder - before.PacketsOutOfOrder,
+		Bytes:             (after.Bytes + after.BytesDuplicate + after.BytesPadding) - (before.Bytes + before.BytesDuplicate + before.BytesPadding),
+	}
+}
+
+func AggregateTrafficStats(statsList ...*TrafficStats) *TrafficStats {
+	if len(statsList) == 0 {
+		return nil
+	}
+
+	startTime := time.Time{}
+	endTime := time.Time{}
+
+	packets := uint32(0)
+	packetsLost := uint32(0)
+	packetsPadding := uint32(0)
+	packetsOutOfOrder := uint32(0)
+	bytes := uint64(0)
+
+	for _, stats := range statsList {
+		if startTime.IsZero() || startTime.After(stats.StartTime) {
+			startTime = stats.StartTime
+		}
+
+		if endTime.IsZero() || endTime.Before(stats.EndTime) {
+			endTime = stats.EndTime
+		}
+
+		packets += stats.Packets
+		packetsLost += stats.PacketsLost
+		packetsPadding += stats.PacketsPadding
+		packetsOutOfOrder += stats.PacketsOutOfOrder
+		bytes += stats.Bytes
+	}
+
+	if endTime.IsZero() {
+		endTime = time.Now()
+	}
+	return &TrafficStats{
+		StartTime:         startTime,
+		EndTime:           endTime,
+		Packets:           packets,
+		PacketsLost:       packetsLost,
+		PacketsPadding:    packetsPadding,
+		PacketsOutOfOrder: packetsOutOfOrder,
+		Bytes:             bytes,
+	}
+}
+
+func TrafficLoadToTrafficRate(trafficLoad *TrafficLoad) (
+	packetRateIn float64,
+	byteRateIn float64,
+	packetRateOut float64,
+	byteRateOut float64,
+) {
+	if trafficLoad == nil {
+		return
+	}
+
+	for _, trafficTypeStat := range trafficLoad.TrafficTypeStats {
+		elapsed := trafficTypeStat.TrafficStats.EndTime.Sub(trafficTypeStat.TrafficStats.StartTime).Seconds()
+		packetRate := float64(trafficTypeStat.TrafficStats.Packets) / elapsed
+		byteRate := float64(trafficTypeStat.TrafficStats.Bytes) / elapsed
+		switch trafficTypeStat.StreamType {
+		case livekit.StreamType_UPSTREAM:
+			packetRateIn += packetRate
+			byteRateIn += byteRate
+		case livekit.StreamType_DOWNSTREAM:
+			packetRateOut += packetRate
+			byteRateOut += byteRate
+		}
+	}
+	return
+}