From 5d49b048fdff8a8d3e12e315eb1807fd9e18cb28 Mon Sep 17 00:00:00 2001
From: mrkubax10 <mrkubax10@onet.pl>
Date: Fri, 9 Feb 2024 12:17:17 +0100
Subject: [PATCH] Adapt NetworkManager retry interval to current reliable
 packet RTT

This will make sure to not drop packets when connection is slower.
---
 src/common/network/network_manager.cpp   | 20 ++++++++++++++------
 src/common/network/network_manager.hpp   |  3 +++
 src/game/screens/game_session_screen.cpp |  1 +
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/common/network/network_manager.cpp b/src/common/network/network_manager.cpp
index 5165065..b51fb7a 100644
--- a/src/common/network/network_manager.cpp
+++ b/src/common/network/network_manager.cpp
@@ -30,7 +30,7 @@ SOFTWARE.
 
 using namespace polygun::network;
 
-static const double NETWORK_MANAGER_PACKET_RETRY_INTERVAL = 4;
+static const time_t NETWORK_MANAGER_PACKET_RETRY_INTERVAL = 4;
 static const uint8_t NETWORK_MANAGER_MAX_RETRY_COUNT = 10;
 
 NetworkManager::NetworkManager(std::shared_ptr<UDPSocket> socket, const NetworkEndpoint& endpoint) :
@@ -40,7 +40,8 @@ NetworkManager::NetworkManager(std::shared_ptr<UDPSocket> socket, const NetworkE
 	m_outgoing_packets(),
 	m_incoming_packets(),
 	m_socket(socket),
-	m_endpoint(endpoint)
+	m_endpoint(endpoint),
+	m_reliable_packet_rtt(0)
 {}
 
 NetworkManager::NetworkManager(const std::string& ip, unsigned short port) :
@@ -50,7 +51,8 @@ NetworkManager::NetworkManager(const std::string& ip, unsigned short port) :
 	m_outgoing_packets(),
 	m_incoming_packets(),
 	m_socket(new UDPSocket),
-	m_endpoint()
+	m_endpoint(),
+	m_reliable_packet_rtt(0)
 {
 	m_socket->connect(ip, port);
 	m_endpoint = m_socket->get_endpoint();
@@ -66,7 +68,7 @@ NetworkPacket NetworkManager::create_packet(uint8_t flags, uint8_t id) {
 void NetworkManager::send_packet(const NetworkPacket& packet) {
 	acquire();
 	if(packet.get_flags() & NetworkPacketFlag::FLAG_RELIABLE) {
-		m_outgoing_packets.push_back(QueuedPacket{packet, -10, 0});
+		m_outgoing_packets.push_back(QueuedPacket{packet, -10, time(nullptr), 0});
 		sort_packets(m_outgoing_packets);
 	}
 	else
@@ -99,8 +101,13 @@ void NetworkManager::push_packet(NetworkPacket& packet) {
 		std::vector<QueuedPacket>::iterator it = std::find_if(m_outgoing_packets.begin(), m_outgoing_packets.end(), [num](const QueuedPacket& queued_packet) {
 			return queued_packet.m_packet.get_num()==num;
 		});
-		if(it!=m_outgoing_packets.end())
+		if(it!=m_outgoing_packets.end()) {
+			m_reliable_packet_rtt = time(nullptr)-it->m_send_time;
+#if defined(NETWORK_MANAGER_VERBOSE)
+			LOG_VERBOSE("Reliable packet RTT: %jd", m_reliable_packet_rtt);
+#endif
 			m_outgoing_packets.erase(it);
+		}
 		release();
 		return;
 	}
@@ -134,7 +141,8 @@ void NetworkManager::update() {
 			i--;
 			continue;
 		}
-		if(time(0)-packet.m_last_retry>=NETWORK_MANAGER_PACKET_RETRY_INTERVAL) {
+		const time_t retry_interval = std::max(NETWORK_MANAGER_PACKET_RETRY_INTERVAL, m_reliable_packet_rtt);
+		if(time(0)-packet.m_last_retry>=retry_interval) {
 			if(packet.m_last_retry>0)
 				LOG_VERBOSE("Resending reliable packet with num %d",packet.m_packet.get_num());
 			m_socket->send(packet.m_packet, m_endpoint);
diff --git a/src/common/network/network_manager.hpp b/src/common/network/network_manager.hpp
index 60a755d..7043428 100644
--- a/src/common/network/network_manager.hpp
+++ b/src/common/network/network_manager.hpp
@@ -38,8 +38,10 @@ namespace polygun::network {
 		struct QueuedPacket {
 			NetworkPacket m_packet;
 			time_t m_last_retry;
+			time_t m_send_time;
 			uint8_t m_retries;
 		};
+
 	public:
 		NetworkManager(std::shared_ptr<UDPSocket> socket, const NetworkEndpoint& endpoint);
 		NetworkManager(const std::string& ip, unsigned short port);
@@ -66,6 +68,7 @@ namespace polygun::network {
 		std::vector<QueuedPacket> m_incoming_packets;
 		std::shared_ptr<UDPSocket> m_socket;
 		NetworkEndpoint m_endpoint;
+		time_t m_reliable_packet_rtt;
 
 	private:
 		static void sort_packets(std::vector<QueuedPacket>& packets);
diff --git a/src/game/screens/game_session_screen.cpp b/src/game/screens/game_session_screen.cpp
index c77bd0e..77e4e39 100644
--- a/src/game/screens/game_session_screen.cpp
+++ b/src/game/screens/game_session_screen.cpp
@@ -236,6 +236,7 @@ void GameSessionScreen::connection_thread_func() {
 					return;
 				case network::NetworkPacketID::PACKET_ACTIVITY:
 					last_server_activity = time(nullptr);
+					continue;
 				default:
 					break;
 				}