show tunlel creation success ratio

HTTPServer.cpp

@@ -659,6 +659,7 @@ namespace util
 			default: s << "Unknown";
 		} 
 		s << "<br>";
+		s << "<b>Tunnel creation success rate:</b> " << i2p::tunnel::tunnels.GetTunnelCreationSuccessRate () << "%<br>";
 		s << "<b>Data path:</b> " << i2p::util::filesystem::GetDataDir().string() << "<br><br>";
 		s << "<b>Our external address:</b>" << "<br>" ;
 		for (auto& address : i2p::context.GetRouterInfo().GetAddresses())

Tunnel.cpp

@@ -203,7 +203,8 @@ namespace tunnel
 
 	Tunnels tunnels;
 
-	Tunnels::Tunnels (): m_IsRunning (false), m_Thread (nullptr)
+	Tunnels::Tunnels (): m_IsRunning (false), m_Thread (nullptr),
+		m_NumSuccesiveTunnelCreations (0), m_NumFailedTunnelCreations (0)
 	{
 	}
 
@@ -488,20 +489,24 @@ namespace tunnel
 					{
 						LogPrint ("Pending tunnel build request ", it->first, " timeout. Deleted");
 						it = pendingTunnels.erase (it);
+						m_NumFailedTunnelCreations++;
 					}
 					else
 						it++;
 				break;
 				case eTunnelStateBuildFailed:
 					LogPrint ("Pending tunnel build request ", it->first, " failed. Deleted");
 					it = pendingTunnels.erase (it);
+					m_NumFailedTunnelCreations++;
 				break;
 				case eTunnelStateBuildReplyReceived:
 					// intermediate state, will be either established of build failed
 					it++;
 				break;	
 				default:
+					// success
 					it = pendingTunnels.erase (it);
+					m_NumSuccesiveTunnelCreations++;
 			}	
 		}	
 	}

Tunnel.h

@@ -175,13 +175,21 @@ namespace tunnel
 			std::shared_ptr<TunnelPool> m_ExploratoryPool;
 			i2p::util::Queue<I2NPMessage> m_Queue;
 
+			// some stats
+			int m_NumSuccesiveTunnelCreations, m_NumFailedTunnelCreations;
+
 		public:
 
 			// for HTTP only
 			const decltype(m_OutboundTunnels)& GetOutboundTunnels () const { return m_OutboundTunnels; };
 			const decltype(m_InboundTunnels)& GetInboundTunnels () const { return m_InboundTunnels; };
 			const decltype(m_TransitTunnels)& GetTransitTunnels () const { return m_TransitTunnels; };
 			int GetQueueSize () { return m_Queue.GetSize (); };
+			int GetTunnelCreationSuccessRate () const // in percents
+			{ 
+				int totalNum = m_NumSuccesiveTunnelCreations + m_NumFailedTunnelCreations;
+				return totalNum ? m_NumSuccesiveTunnelCreations*100/totalNum : 0;
+			}		
 	};	
 
 	extern Tunnels tunnels;