From 51cbffd097f6d3c55e40c4faabd89cbe108339db Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Thu, 7 Apr 2022 10:57:57 -0400
Subject: [PATCH] don't lookup session for every sinle packet

---
 libi2pd/SSU2.cpp | 19 ++++++++++++++-----
 libi2pd/SSU2.h   |  1 +
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/libi2pd/SSU2.cpp b/libi2pd/SSU2.cpp
index a27cf063..433a3afb 100644
--- a/libi2pd/SSU2.cpp
+++ b/libi2pd/SSU2.cpp
@@ -1282,13 +1282,20 @@ namespace transport
 		uint64_t connID;
 		memcpy (&connID, buf, 8);
 		connID ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 24));
-		auto it = m_Sessions.find (connID);
-		if (it != m_Sessions.end ())
+		if (!m_LastSession || m_LastSession->GetConnID () != connID)
 		{
-			if (it->second->IsEstablished ())
-				it->second->ProcessData (buf, len);
+			auto it = m_Sessions.find (connID);
+			if (it != m_Sessions.end ())
+				m_LastSession = it->second;
+			else
+				m_LastSession = nullptr;
+		}
+		if (m_LastSession)
+		{
+			if (m_LastSession->IsEstablished ())
+				m_LastSession->ProcessData (buf, len);
 			else	
-				it->second->ProcessSessionConfirmed (buf, len);
+				m_LastSession->ProcessSessionConfirmed (buf, len);
 		}	
 		else 
 		{
@@ -1388,6 +1395,8 @@ namespace transport
 				{
 					if (it->second->IsEstablished ())
 						it->second->TerminateByTimeout ();
+					if (it->second == m_LastSession)
+						 m_LastSession = nullptr;
 					it = m_Sessions.erase (it); 
 				}
 				else
diff --git a/libi2pd/SSU2.h b/libi2pd/SSU2.h
index 43bc35f3..f9d0f848 100644
--- a/libi2pd/SSU2.h
+++ b/libi2pd/SSU2.h
@@ -269,6 +269,7 @@ namespace transport
 			std::map<boost::asio::ip::udp::endpoint, std::pair<uint64_t, uint32_t> > m_IncomingTokens, m_OutgoingTokens; // remote endpoint -> (token, expires in seconds)
 			i2p::util::MemoryPoolMt<Packet> m_PacketsPool;
 			boost::asio::deadline_timer m_TerminationTimer, m_ResendTimer;
+			std::shared_ptr<SSU2Session> m_LastSession;
 
 		public: