X-Git-Url: http://git.localhorst.tv/?a=blobdiff_plain;f=src%2Fnet%2Fnet.cpp;h=5d062343b8976f28425b3c45fd7b704dc00e0e2b;hb=ec40d74319e24480c00f63cb6cfdbd6e1c454f3d;hp=9b50479b135445ae0225a28f98653fee18c6f000;hpb=33b37e7242e4cbfa76e4a0d6e5bb54223b541162;p=blank.git

diff --git a/src/net/net.cpp b/src/net/net.cpp
index 9b50479..5d06234 100644
--- a/src/net/net.cpp
+++ b/src/net/net.cpp
@@ -1,9 +1,11 @@
+#include "CongestionControl.hpp"
 #include "Connection.hpp"
 #include "ConnectionHandler.hpp"
 #include "io.hpp"
 #include "Packet.hpp"
 
 #include "../app/init.hpp"
+#include "../geometry/const.hpp"
 #include "../model/Model.hpp"
 #include "../world/Entity.hpp"
 #include "../world/EntityState.hpp"
@@ -30,6 +32,168 @@ constexpr size_t Packet::BlockUpdate::MAX_LEN;
 constexpr size_t Packet::Message::MAX_LEN;
 constexpr size_t Packet::Message::MAX_MESSAGE_LEN;
 
+
+CongestionControl::CongestionControl()
+// I know, I know, it's an estimate (about 20 for IPv4, 48 for IPv6)
+: packet_overhead(20)
+// only sample every eighth packet for measuring RTT
+, sample_skip(8)
+, packets_lost(0)
+, packets_received(0)
+, packet_loss(0.0f)
+, stamp_cursor(15)
+, stamp_last(0)
+, rtt(64.0f)
+, next_sample(1000)
+, tx_bytes(0)
+, rx_bytes(0)
+, tx_kbps(0.0f)
+, rx_kbps(0.0f)
+, mode(GOOD)
+// rtt > 100ms or packet loss > 5% is BAD
+, bad_rtt(100.0f)
+, bad_loss(0.05f)
+// rtt > 250ms or packet loss > 15% is UGLY
+, ugly_rtt(250.0f)
+, ugly_loss(0.15f)
+, mode_keep_time(1000) {
+	Uint32 now = SDL_GetTicks();
+	for (Uint32 &s : stamps) {
+		s = now;
+	}
+	next_sample += now;
+	mode_entered = now;
+	mode_reset = now;
+	mode_step = now;
+}
+
+void CongestionControl::PacketSent(uint16_t seq) noexcept {
+	if (!SamplePacket(seq)) {
+		return;
+	}
+	stamp_cursor = (stamp_cursor + 1) % 16;
+	stamps[stamp_cursor] = SDL_GetTicks();
+	stamp_last = seq;
+}
+
+void CongestionControl::PacketLost(uint16_t seq) noexcept {
+	++packets_lost;
+	UpdatePacketLoss();
+	UpdateRTT(seq);
+}
+
+void CongestionControl::PacketReceived(uint16_t seq) noexcept {
+	++packets_received;
+	UpdatePacketLoss();
+	UpdateRTT(seq);
+}
+
+void CongestionControl::UpdatePacketLoss() noexcept {
+	unsigned int packets_total = packets_lost + packets_received;
+	if (packets_total >= 256) {
+		packet_loss = float(packets_lost) / float(packets_total);
+		packets_lost = 0;
+		packets_received = 0;
+	}
+}
+
+void CongestionControl::UpdateRTT(std::uint16_t seq) noexcept {
+	if (!SamplePacket(seq)) return;
+	int16_t diff = int16_t(seq) - int16_t(stamp_last);
+	diff /= sample_skip;
+	if (diff > 0 || diff < -15) {
+		// packet outside observed time frame
+		return;
+	}
+	int cur_rtt = SDL_GetTicks() - stamps[(stamp_cursor + diff + 16) % 16];
+	rtt += (cur_rtt - rtt) * 0.1f;
+}
+
+bool CongestionControl::SamplePacket(std::uint16_t seq) const noexcept {
+	return seq % sample_skip == 0;
+}
+
+void CongestionControl::PacketIn(const UDPpacket &pack) noexcept {
+	rx_bytes += pack.len + packet_overhead;
+	UpdateStats();
+}
+
+void CongestionControl::PacketOut(const UDPpacket &pack) noexcept {
+	tx_bytes += pack.len + packet_overhead;
+	UpdateStats();
+}
+
+void CongestionControl::UpdateStats() noexcept {
+	Uint32 now = SDL_GetTicks();
+	if (now < next_sample) {
+		// not yet
+		return;
+	}
+	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;
+	UpdateMode();
+}
+
+void CongestionControl::UpdateMode() noexcept {
+	Mode now_mode = Conditions();
+	if (now_mode > mode) {
+		ChangeMode(now_mode);
+	} else if (now_mode < mode) {
+		CheckUpgrade(now_mode);
+	} else {
+		KeepMode();
+	}
+}
+
+void CongestionControl::CheckUpgrade(Mode m) noexcept {
+	Uint32 now = SDL_GetTicks();
+	Uint32 time_in_mode = now - mode_entered;
+	if (time_in_mode < mode_keep_time) {
+		return;
+	}
+	ChangeMode(m);
+}
+
+void CongestionControl::ChangeMode(Mode m) noexcept {
+	Uint32 now = SDL_GetTicks();
+	if (m > mode) {
+		// changed to worse mode
+		// if we spent less than 10 seconds in better mode
+		// double keep time till up to 64 seconds
+		if (now - mode_entered < 10000) {
+			if (mode_keep_time < 64000) {
+				mode_keep_time *= 2;
+			}
+		}
+	}
+	mode = m;
+	mode_entered = now;
+	mode_reset = mode_entered;
+}
+
+void CongestionControl::KeepMode() noexcept {
+	mode_reset = SDL_GetTicks();
+	// if in good mode for 10 seconds, halve keep time till down to one second
+	if (mode == GOOD && mode_keep_time > 1000 && mode_step - mode_reset > 10000) {
+		mode_keep_time /= 2;
+		mode_step = mode_reset;
+	}
+}
+
+CongestionControl::Mode CongestionControl::Conditions() const noexcept {
+	if (rtt > ugly_rtt || packet_loss > ugly_loss) {
+		return UGLY;
+	} else if (rtt > bad_rtt || packet_loss > bad_loss) {
+		return BAD;
+	} else {
+		return GOOD;
+	}
+}
+
+
 Connection::Connection(const IPaddress &addr)
 : handler(nullptr)
 , addr(addr)
@@ -84,6 +248,11 @@ uint16_t Connection::Send(UDPpacket &udp_pack, UDPsocket sock) {
 		throw NetError("SDLNet_UDP_Send");
 	}
 
+	if (HasHandler()) {
+		Handler().PacketOut(udp_pack);
+		Handler().PacketSent(seq);
+	}
+
 	FlagSend();
 	return seq;
 }
@@ -111,6 +280,7 @@ 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) {
@@ -149,31 +319,30 @@ uint16_t Connection::SendPing(UDPpacket &udp_pack, UDPsocket sock) {
 
 
 ConnectionHandler::ConnectionHandler()
-: packets_lost(0)
-, packets_received(0)
-, packet_loss(0.0f) {
+: cc() {
 
 }
 
+void ConnectionHandler::PacketSent(uint16_t seq) noexcept {
+	cc.PacketSent(seq);
+}
+
 void ConnectionHandler::PacketLost(uint16_t seq) {
 	OnPacketLost(seq);
-	++packets_lost;
-	UpdatePacketLoss();
+	cc.PacketLost(seq);
 }
 
 void ConnectionHandler::PacketReceived(uint16_t seq) {
 	OnPacketReceived(seq);
-	++packets_received;
-	UpdatePacketLoss();
+	cc.PacketReceived(seq);
 }
 
-void ConnectionHandler::UpdatePacketLoss() noexcept {
-	unsigned int packets_total = packets_lost + packets_received;
-	if (packets_total >= 256) {
-		packet_loss = float(packets_lost) / float(packets_total);
-		packets_lost = 0;
-		packets_received = 0;
-	}
+void ConnectionHandler::PacketIn(const UDPpacket &pack) noexcept {
+	cc.PacketIn(pack);
+}
+
+void ConnectionHandler::PacketOut(const UDPpacket &pack) noexcept {
+	cc.PacketOut(pack);
 }
 
 
@@ -277,8 +446,8 @@ void Packet::Payload::Read(glm::quat &val, size_t off) const noexcept {
 }
 
 void Packet::Payload::Write(const EntityState &state, size_t off) noexcept {
-	Write(state.chunk_pos, off);
-	WritePackU(state.block_pos * (1.0f / 16.0f), off + 12);
+	Write(state.pos.chunk, off);
+	WritePackU(state.pos.block * (1.0f / ExactLocation::fscale), off + 12);
 	Write(state.velocity, off + 18);
 	Write(state.orient, off + 30);
 	WritePackN(state.pitch * PI_0p5_inv, off + 38);
@@ -286,20 +455,20 @@ void Packet::Payload::Write(const EntityState &state, size_t off) noexcept {
 }
 
 void Packet::Payload::Read(EntityState &state, size_t off) const noexcept {
-	Read(state.chunk_pos, off);
-	ReadPackU(state.block_pos, off + 12);
+	Read(state.pos.chunk, off);
+	ReadPackU(state.pos.block, off + 12);
 	Read(state.velocity, off + 18);
 	Read(state.orient, off + 30);
 	ReadPackN(state.pitch, off + 38);
 	ReadPackN(state.yaw, off + 40);
-	state.block_pos *= 16.0f;
+	state.pos.block *= ExactLocation::fscale;
 	state.pitch *= PI_0p5;
 	state.yaw *= PI;
 }
 
 void Packet::Payload::Write(const EntityState &state, const glm::ivec3 &base, size_t off) noexcept {
-	WritePackB(state.chunk_pos - base, off);
-	WritePackU(state.block_pos * (1.0f / 16.0f), off + 3);
+	WritePackB(state.pos.chunk - base, off);
+	WritePackU(state.pos.block * (1.0f / ExactLocation::fscale), off + 3);
 	Write(state.velocity, off + 9);
 	Write(state.orient, off + 21);
 	WritePackN(state.pitch * PI_0p5_inv, off + 29);
@@ -307,14 +476,14 @@ void Packet::Payload::Write(const EntityState &state, const glm::ivec3 &base, si
 }
 
 void Packet::Payload::Read(EntityState &state, const glm::ivec3 &base, size_t off) const noexcept {
-	ReadPackB(state.chunk_pos, off);
-	ReadPackU(state.block_pos, off + 3);
+	ReadPackB(state.pos.chunk, off);
+	ReadPackU(state.pos.block, off + 3);
 	Read(state.velocity, off + 9);
 	Read(state.orient, off + 21);
 	ReadPackN(state.pitch, off + 29);
 	ReadPackN(state.yaw, off + 31);
-	state.chunk_pos += base;
-	state.block_pos *= 16.0f;
+	state.pos.chunk += base;
+	state.pos.block *= ExactLocation::fscale;
 	state.pitch *= PI_0p5;
 	state.yaw *= PI;
 }