allow 0ms latency for tunnel

libi2pd/Tunnel.cpp

@@ -33,7 +33,7 @@ namespace tunnel
 		TunnelBase (config->GetTunnelID (), config->GetNextTunnelID (), config->GetNextIdentHash ()),
 		m_Config (config), m_IsShortBuildMessage (false), m_Pool (nullptr),
 		m_State (eTunnelStatePending), m_FarEndTransports (i2p::data::RouterInfo::eAllTransports),
-		m_IsRecreated (false), m_Latency (0)
+		m_IsRecreated (false), m_Latency (UNKNOWN_LATENCY)
 	{
 	}
 
@@ -198,10 +198,10 @@ namespace tunnel
 		return established;
 	}
 
-	bool Tunnel::LatencyFitsRange(uint64_t lower, uint64_t upper) const
+	bool Tunnel::LatencyFitsRange(int lowerbound, int upperbound) const
 	{
 		auto latency = GetMeanLatency();
-		return latency >= lower && latency <= upper;
+		return latency >= lowerbound && latency <= upperbound;
 	}
 
 	void Tunnel::EncryptTunnelMsg (std::shared_ptr<const I2NPMessage> in, std::shared_ptr<I2NPMessage> out)

libi2pd/Tunnel.h

@@ -39,6 +39,7 @@ namespace tunnel
 	const int TUNNEL_CREATION_TIMEOUT = 30; // 30 seconds
 	const int STANDARD_NUM_RECORDS = 4; // in VariableTunnelBuild message
 	const int MAX_NUM_RECORDS = 8;
+	const int UNKNOWN_LATENCY = -1;
 	const int HIGH_LATENCY_PER_HOP = 250; // in milliseconds
 	const int MAX_TUNNEL_MSGS_BATCH_SIZE = 100; // handle messages without interrupt
 	const uint16_t DEFAULT_MAX_NUM_TRANSIT_TUNNELS = 5000;
@@ -108,14 +109,14 @@ namespace tunnel
 			void EncryptTunnelMsg (std::shared_ptr<const I2NPMessage> in, std::shared_ptr<I2NPMessage> out) override;
 
 			/** @brief add latency sample */
-			void AddLatencySample(const uint64_t ms) { m_Latency = (m_Latency + ms) >> 1; }
+			void AddLatencySample(const int ms) { m_Latency = LatencyIsKnown() ? (m_Latency + ms) >> 1 : ms; }
 			/** @brief get this tunnel's estimated latency */
-			uint64_t GetMeanLatency() const { return m_Latency; }
+			int GetMeanLatency() const { return m_Latency; }
 			/** @brief return true if this tunnel's latency fits in range [lowerbound, upperbound] */
-			bool LatencyFitsRange(uint64_t lowerbound, uint64_t upperbound) const;
+			bool LatencyFitsRange(int lowerbound, int upperbound) const;
 
-			bool LatencyIsKnown() const { return m_Latency > 0; }
+			bool LatencyIsKnown() const { return m_Latency != UNKNOWN_LATENCY; }
-			bool IsSlow () const { return LatencyIsKnown() && (int)m_Latency > HIGH_LATENCY_PER_HOP*GetNumHops (); }
+			bool IsSlow () const { return LatencyIsKnown() && m_Latency > HIGH_LATENCY_PER_HOP*GetNumHops (); }
 
 			/** visit all hops we currently store */
 			void VisitTunnelHops(TunnelHopVisitor v);
@@ -129,7 +130,7 @@ namespace tunnel
 			TunnelState m_State;
 			i2p::data::RouterInfo::CompatibleTransports m_FarEndTransports;
 			bool m_IsRecreated; // if tunnel is replaced by new, or new tunnel requested to replace
-			uint64_t m_Latency; // in milliseconds
+			int m_Latency; // in milliseconds
 	};
 
 	class OutboundTunnel: public Tunnel

libi2pd/TunnelPool.cpp

@@ -477,8 +477,10 @@ namespace tunnel
 		}
 		if (found)
 		{
-			uint64_t dlt = i2p::util::GetMillisecondsSinceEpoch () - timestamp;
+			int dlt = (int)((int64_t)i2p::util::GetMillisecondsSinceEpoch () - (int64_t)timestamp);
 			LogPrint (eLogDebug, "Tunnels: Test of ", msgID, " successful. ", dlt, " milliseconds");
+			if (dlt < 0)
+				dlt = 0;
 			int numHops = 0;
 			if (test.first) numHops += test.first->GetNumHops ();
 			if (test.second) numHops += test.second->GetNumHops ();
@@ -488,7 +490,7 @@ namespace tunnel
 				if (test.first->GetState () != eTunnelStateExpiring)
 					test.first->SetState (eTunnelStateEstablished);
 				// update latency
-				uint64_t latency = 0;
+				int latency = 0;
 				if (numHops) latency = dlt*test.first->GetNumHops ()/numHops;
 				if (!latency) latency = dlt/2;
 				test.first->AddLatencySample(latency);
@@ -498,7 +500,7 @@ namespace tunnel
 				if (test.second->GetState () != eTunnelStateExpiring)
 					test.second->SetState (eTunnelStateEstablished);
 				// update latency
-				uint64_t latency = 0;
+				int latency = 0;
 				if (numHops) latency = dlt*test.second->GetNumHops ()/numHops;
 				if (!latency) latency = dlt/2;
 				test.second->AddLatencySample(latency);

libi2pd/TunnelPool.h

@@ -105,7 +105,7 @@ namespace tunnel
 			bool HasCustomPeerSelector();
 
 			/** @brief make this tunnel pool yield tunnels that fit latency range [min, max] */
-			void RequireLatency(uint64_t min, uint64_t max) { m_MinLatency = min; m_MaxLatency = max; }
+			void RequireLatency(int min, int max) { m_MinLatency = min; m_MaxLatency = max; }
 
 			/** @brief return true if this tunnel pool has a latency requirement */
 			bool HasLatencyRequirement() const { return m_MinLatency > 0 && m_MaxLatency > 0; }
@@ -150,8 +150,8 @@ namespace tunnel
 			std::mutex m_CustomPeerSelectorMutex;
 			ITunnelPeerSelector * m_CustomPeerSelector;
 
-			uint64_t m_MinLatency = 0; // if > 0 this tunnel pool will try building tunnels with minimum latency by ms
+			int m_MinLatency = 0; // if > 0 this tunnel pool will try building tunnels with minimum latency by ms
-			uint64_t m_MaxLatency = 0; // if > 0 this tunnel pool will try building tunnels with maximum latency by ms
+			int m_MaxLatency = 0; // if > 0 this tunnel pool will try building tunnels with maximum latency by ms
 
 			std::random_device m_Rd;
 			std::mt19937 m_Rng;