From 015bb899f8e3fb014bfa69fdcbb30db1c1163384 Mon Sep 17 00:00:00 2001
From: Daniel Karbach <daniel.karbach@localhorst.tv>
Date: Tue, 27 Oct 2015 13:47:08 +0100
Subject: [PATCH] collect network bandwidth usage stats

---
 src/net/ConnectionHandler.hpp | 16 +++++++++++++++-
 src/net/net.cpp               | 33 +++++++++++++++++++++++++++++++--
 2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/src/net/ConnectionHandler.hpp b/src/net/ConnectionHandler.hpp
index be01d10..76103fe 100644
--- a/src/net/ConnectionHandler.hpp
+++ b/src/net/ConnectionHandler.hpp
@@ -17,11 +17,18 @@ public:
 	float PacketLoss() const noexcept { return packet_loss; }
 	/// smooth average round trip time in milliseconds
 	float RoundTripTime() const noexcept { return rtt; }
+	/// estimated kilobytes transferred per second
+	float Upstream() const noexcept { return tx_kbps; }
+	/// estimated kilobytes received per second
+	float Downstream() const noexcept { return rx_kbps; }
 
-	void PacketSent(std::uint16_t);
+	void PacketSent(std::uint16_t) noexcept;
 	void PacketLost(std::uint16_t);
 	void PacketReceived(std::uint16_t);
 
+	void PacketIn(const UDPpacket &) noexcept;
+	void PacketOut(const UDPpacket &) noexcept;
+
 	void Handle(const UDPpacket &);
 
 	virtual void OnTimeout() { }
@@ -31,6 +38,7 @@ private:
 	void UpdateRTT(std::uint16_t) noexcept;
 	bool SamplePacket(std::uint16_t) const noexcept;
 	int HeadDiff(std::uint16_t) const noexcept;
+	void UpdateStats() noexcept;
 
 	// called as soon as the remote end ack'd given packet
 	virtual void OnPacketReceived(std::uint16_t) { }
@@ -61,6 +69,12 @@ private:
 	std::uint16_t stamp_last;
 	float rtt;
 
+	Uint32 next_sample;
+	std::size_t tx_bytes;
+	std::size_t rx_bytes;
+	float tx_kbps;
+	float rx_kbps;
+
 };
 
 }
diff --git a/src/net/net.cpp b/src/net/net.cpp
index 59176aa..0686d54 100644
--- a/src/net/net.cpp
+++ b/src/net/net.cpp
@@ -85,6 +85,7 @@ uint16_t Connection::Send(UDPpacket &udp_pack, UDPsocket sock) {
 	}
 
 	if (HasHandler()) {
+		Handler().PacketOut(udp_pack);
 		Handler().PacketSent(seq);
 	}
 
@@ -115,6 +116,7 @@ void Connection::Received(const UDPpacket &udp_pack) {
 	}
 
 	Packet::TControl ctrl_new = pack.header.ctrl;
+	Handler().PacketIn(udp_pack);
 	Handler().Handle(udp_pack);
 
 	if (diff > 0) {
@@ -158,14 +160,20 @@ ConnectionHandler::ConnectionHandler()
 , packet_loss(0.0f)
 , stamp_cursor(15)
 , stamp_last(0)
-, rtt(64.0f) {
+, rtt(64.0f)
+, next_sample(1000)
+, tx_bytes(0)
+, rx_bytes(0)
+, tx_kbps(0.0f)
+, rx_kbps(0.0f) {
 	Uint32 now = SDL_GetTicks();
 	for (Uint32 &s : stamps) {
 		s = now;
 	}
+	next_sample += now;
 }
 
-void ConnectionHandler::PacketSent(uint16_t seq) {
+void ConnectionHandler::PacketSent(uint16_t seq) noexcept {
 	if (!SamplePacket(seq)) {
 		return;
 	}
@@ -218,6 +226,27 @@ int ConnectionHandler::HeadDiff(std::uint16_t seq) const noexcept {
 	return diff / 8;
 }
 
+void ConnectionHandler::PacketIn(const UDPpacket &pack) noexcept {
+	rx_bytes += pack.len + 20; // I know, I know, it's an estimate (about 48 for IPv6)
+	UpdateStats();
+}
+
+void ConnectionHandler::PacketOut(const UDPpacket &pack) noexcept {
+	tx_bytes += pack.len + 20;
+	UpdateStats();
+}
+
+void ConnectionHandler::UpdateStats() noexcept {
+	Uint32 now = SDL_GetTicks();
+	if (now >= next_sample) {
+		tx_kbps = float(tx_bytes) * (1.0f / 1024.0f);
+		rx_kbps = float(rx_bytes) * (1.0f / 1024.0f);
+		tx_bytes = 0;
+		rx_bytes = 0;
+		next_sample += 1000;
+	}
+}
+
 
 ostream &operator <<(ostream &out, const IPaddress &addr) {
 	const unsigned char *host = reinterpret_cast<const unsigned char *>(&addr.host);
-- 
2.39.2