shorter ack request interval for datagrams

libi2pd/Datagram.cpp

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2024, The PurpleI2P Project
+* Copyright (c) 2013-2025, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -104,8 +104,7 @@ namespace datagram
 
 		if (verified)
 		{
-			auto h = identity.GetIdentHash();
-			auto session = ObtainSession(h);
+			auto session = ObtainSession (identity.GetIdentHash());
 			session->Ack();
 			auto r = FindReceiver(toPort);
 			if(r)
@@ -381,10 +380,14 @@ namespace datagram
 			if (!found)
 			{
 				m_RoutingSession = m_LocalDestination->GetRoutingSession(m_RemoteLeaseSet, true);
+				if (m_RoutingSession)
+				{	
+					m_RoutingSession->SetAckRequestInterval (DATAGRAM_SESSION_ACK_REQUEST_INTERVAL);
 					if (!m_RoutingSession->GetOwner () || !m_RoutingSession->IsReadyToSend ())
 						m_PendingRoutingSessions.push_back (m_RoutingSession);
 				}	
 			}
+		}
 
 		auto path = m_RoutingSession->GetSharedRoutingPath();
 		if (path && m_RoutingSession->IsRatchets () && (m_RoutingSession->CleanupUnconfirmedTags () ||

libi2pd/Datagram.h

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2024, The PurpleI2P Project
+* Copyright (c) 2013-2025, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -44,6 +44,7 @@ namespace datagram
 	// max 64 messages buffered in send queue for each datagram session
 	const size_t DATAGRAM_SEND_QUEUE_MAX_SIZE = 64;
 	const uint64_t DATAGRAM_MAX_FLUSH_INTERVAL = 5; // in milliseconds
+	const int DATAGRAM_SESSION_ACK_REQUEST_INTERVAL = 5500; // in milliseconds
 
 	class DatagramSession : public std::enable_shared_from_this<DatagramSession>
 	{

libi2pd/ECIESX25519AEADRatchetSession.cpp

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2024, The PurpleI2P Project
+* Copyright (c) 2013-2025, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -913,7 +913,7 @@ namespace garlic
 			}
 		}
 		if (!sendAckRequest && !first &&
-		    ((!m_AckRequestMsgID && ts > m_LastAckRequestSendTime + ECIESX25519_ACK_REQUEST_INTERVAL) || // regular request
+		    ((!m_AckRequestMsgID && ts > m_LastAckRequestSendTime + m_AckRequestInterval) || // regular request
 		     (m_AckRequestMsgID && ts > m_LastAckRequestSendTime + LEASESET_CONFIRMATION_TIMEOUT))) // previous request failed. try again
 		{	
 			// not LeaseSet

libi2pd/ECIESX25519AEADRatchetSession.h

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2024, The PurpleI2P Project
+* Copyright (c) 2013-2025, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -33,7 +33,7 @@ namespace garlic
 	const int ECIESX25519_SESSION_CREATE_TIMEOUT = 3; // in seconds, NSR must be send after NS received
 	const int ECIESX25519_SESSION_ESTABLISH_TIMEOUT = 15; // in seconds 
 	const int ECIESX25519_PREVIOUS_TAGSET_EXPIRATION_TIMEOUT = 180; // in seconds
-	const int ECIESX25519_ACK_REQUEST_INTERVAL = 33000; // in milliseconds
+	const int ECIESX25519_DEFAULT_ACK_REQUEST_INTERVAL = 33000; // in milliseconds
 	const int ECIESX25519_ACK_REQUEST_MAX_NUM_ATTEMPTS = 3;
 	const int ECIESX25519_TAGSET_MAX_NUM_TAGS = 8192; // number of tags we request new tagset after
 	const int ECIESX25519_MIN_NUM_GENERATED_TAGS = 24;
@@ -164,7 +164,7 @@ namespace garlic
 			~ECIESX25519AEADRatchetSession ();
 
 			bool HandleNextMessage (uint8_t * buf, size_t len, std::shared_ptr<ReceiveRatchetTagSet> receiveTagset, int index = 0);
-			std::shared_ptr<I2NPMessage> WrapSingleMessage (std::shared_ptr<const I2NPMessage> msg);
+			std::shared_ptr<I2NPMessage> WrapSingleMessage (std::shared_ptr<const I2NPMessage> msg) override;
 			std::shared_ptr<I2NPMessage> WrapOneTimeMessage (std::shared_ptr<const I2NPMessage> msg);
 
 			const uint8_t * GetRemoteStaticKey () const { return m_RemoteStaticKey; }
@@ -180,11 +180,12 @@ namespace garlic
 			bool CanBeRestarted (uint64_t ts) const { return ts > m_SessionCreatedTimestamp + ECIESX25519_RESTART_TIMEOUT; }
 			bool IsInactive (uint64_t ts) const { return ts > m_LastActivityTimestamp + ECIESX25519_INACTIVITY_TIMEOUT && CanBeRestarted (ts); }
 
-			bool IsRatchets () const { return true; };
-			bool IsReadyToSend () const { return m_State != eSessionStateNewSessionSent; };
-			bool IsTerminated () const { return m_IsTerminated; }
-			uint64_t GetLastActivityTimestamp () const { return m_LastActivityTimestamp; };
-			bool CleanupUnconfirmedTags (); // return true if unaswered Ack requests, called from I2CP
+			bool IsRatchets () const override { return true; };
+			bool IsReadyToSend () const override { return m_State != eSessionStateNewSessionSent; };
+			bool IsTerminated () const override { return m_IsTerminated; }
+			uint64_t GetLastActivityTimestamp () const override { return m_LastActivityTimestamp; };
+			void SetAckRequestInterval (int interval) override { m_AckRequestInterval = interval; };
+			bool CleanupUnconfirmedTags () override; // return true if unaswered Ack requests, called from I2CP
 			
 		protected:
 
@@ -235,6 +236,7 @@ namespace garlic
 			uint64_t m_LastAckRequestSendTime = 0; // milliseconds
 			uint32_t m_AckRequestMsgID = 0; 
 			int m_AckRequestNumAttempts = 0;
+			int m_AckRequestInterval = ECIESX25519_DEFAULT_ACK_REQUEST_INTERVAL; // milliseconds
 			
 		public:
 

libi2pd/Garlic.h

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2024, The PurpleI2P Project
+* Copyright (c) 2013-2025, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -116,6 +116,7 @@ namespace garlic
 			virtual bool IsReadyToSend () const { return true; };
 			virtual bool IsTerminated () const { return !GetOwner (); };
 			virtual uint64_t GetLastActivityTimestamp () const { return 0; }; // non-zero for rathets only
+			virtual void SetAckRequestInterval (int interval) {}; // in milliseconds, override in ECIESX25519AEADRatchetSession
 			
 			void SetLeaseSetUpdated ()
 			{