Improve resend algorithm to be exact about when to resend

common/net/daybreak_connection.cpp

@@ -44,12 +44,7 @@ void EQ::Net::DaybreakConnectionManager::Attach(uv_loop_t *loop)
 			DaybreakConnectionManager *c = (DaybreakConnectionManager*)handle->data;
 			c->UpdateDataBudget();
 			c->Process();
-			auto now = Clock::now();
+			c->ProcessResend();
-			if (std::chrono::duration_cast<std::chrono::milliseconds>(now - c->m_last_resend_check).count() > c->m_resend_check_interval) {
-				c->ProcessResend();
-				c->m_last_resend_check = now;
-				return;
-			}
 		}, update_rate, update_rate);
 
 		uv_udp_init(loop, &m_socket);
@@ -1122,16 +1117,53 @@ void EQ::Net::DaybreakConnection::ProcessResend(int stream)
 		reference_resend_delay = s->sent_packets.begin()->second.resend_delay;
 
 		// Check if the first packet has timed out
-		auto time_since_first_sent = std::chrono::duration_cast<std::chrono::milliseconds>(now - s->sent_packets.begin()->second.first_sent).count();
+		auto &first_packet = s->sent_packets.begin()->second;
+		auto time_since_first_sent = std::chrono::duration_cast<std::chrono::milliseconds>(now - first_packet.first_sent).count();
+
+		// make sure that the first_packet in the list first_sent time is within the resend_delay and now
+		// if it is not, then we need to resend all packets in the list
+		if (time_since_first_sent <= first_packet.resend_delay && !m_acked_since_last_resend) {
+			LogNetcodeDetail(
+				"Not resending packets for stream [{}] time since first sent [{}] resend delay [{}] m_acked_since_last_resend [{}]",
+				stream,
+				time_since_first_sent,
+				first_packet.resend_delay,
+				m_acked_since_last_resend
+			);
+			return;
+		}
+
 		if (time_since_first_sent >= m_owner->m_options.resend_timeout) {
 			Close();
 			return;
 		}
 	}
 
+	if (LogSys.IsLogEnabled(Logs::Detail, Logs::Netcode)) {
+		size_t    total_size = 0;
+		for (auto &e: s->sent_packets) {
+			total_size += e.second.packet.Length();
+		}
+
+		LogNetcodeDetail(
+			"Resending packets for stream [{}] packet count [{}] total packet size [{}] m_acked_since_last_resend [{}]",
+			stream,
+			s->sent_packets.size(),
+			total_size,
+			m_acked_since_last_resend
+		);
+	}
+
 	for (auto &e: s->sent_packets) {
 		if (m_resend_packets_sent >= MAX_CLIENT_RECV_PACKETS_PER_WINDOW ||
 			m_resend_bytes_sent >= MAX_CLIENT_RECV_BYTES_PER_WINDOW) {
+			LogNetcodeDetail(
+				"Stopping resend because we hit thresholds m_resend_packets_sent [{}] max [{}] m_resend_bytes_sent [{}] max [{}]",
+				m_resend_packets_sent,
+				MAX_CLIENT_RECV_PACKETS_PER_WINDOW,
+				m_resend_bytes_sent,
+				MAX_CLIENT_RECV_BYTES_PER_WINDOW
+			);
 			break;
 		}
 
@@ -1163,6 +1195,8 @@ void EQ::Net::DaybreakConnection::ProcessResend(int stream)
 			m_owner->m_options.resend_delay_max
 		);
 	}
+
+	m_acked_since_last_resend = false;
 }
 
 void EQ::Net::DaybreakConnection::Ack(int stream, uint16_t seq)
@@ -1183,6 +1217,7 @@ void EQ::Net::DaybreakConnection::Ack(int stream, uint16_t seq)
 			m_rolling_ping = (m_rolling_ping * 2 + round_time) / 3;
 
 			iter = s->sent_packets.erase(iter);
+			m_acked_since_last_resend = true;
 		}
 		else {
 			++iter;

common/net/daybreak_connection.h

@@ -184,6 +184,7 @@ namespace EQ
 			// resend tracking
 			size_t m_resend_packets_sent = 0;
 			size_t m_resend_bytes_sent = 0;
+			bool m_acked_since_last_resend = false;
 
 			struct DaybreakSentPacket
 			{
@@ -322,10 +323,6 @@ namespace EQ
 			void Attach(uv_loop_t *loop);
 			void Detach();
 
-			// resend
-			Timestamp m_last_resend_check;
-			int m_resend_check_interval = 50;
-
 			EQ::Random m_rand;
 			uv_timer_t m_timer;
 			uv_udp_t m_socket;