send multiple messages though single write call

NTCPSession.cpp

@@ -547,6 +547,12 @@ namespace transport
  	}	
 
 	void NTCPSession::Send (i2p::I2NPMessage * msg)
+	{
+		boost::asio::async_write (m_Socket, CreateMsgBuffer (msg), boost::asio::transfer_all (),                      
+        	std::bind(&NTCPSession::HandleSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2, msg));	
+	}
+
+	boost::asio::const_buffers_1 NTCPSession::CreateMsgBuffer (I2NPMessage * msg)
 	{
 		uint8_t * sendBuffer;
 		int len;
@@ -579,9 +585,7 @@ namespace transport
 
 		int l = len + padding + 6;
 		m_Encryption.Encrypt(sendBuffer, l, sendBuffer);	
-
-		boost::asio::async_write (m_Socket, boost::asio::buffer (sendBuffer, l), boost::asio::transfer_all (),                      
-        	std::bind(&NTCPSession::HandleSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2, msg));	
+		return boost::asio::buffer ((const uint8_t *)sendBuffer, l);
 	}	
 		
 	void NTCPSession::HandleSent (const boost::system::error_code& ecode, std::size_t bytes_transferred, i2p::I2NPMessage * msg)
@@ -602,6 +606,34 @@ namespace transport
 		}	
 	}
 
+	void NTCPSession::Send (const std::vector<I2NPMessage *>& msgs)
+	{
+		std::vector<boost::asio::const_buffer> bufs;
+		for (auto it: msgs)
+			bufs.push_back (CreateMsgBuffer (it));
+		boost::asio::async_write (m_Socket, bufs, boost::asio::transfer_all (),                      
+        	std::bind(&NTCPSession::HandleBatchSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2, msgs));
+	}
+		
+	void NTCPSession::HandleBatchSent (const boost::system::error_code& ecode, std::size_t bytes_transferred, std::vector<I2NPMessage *> msgs)
+	{
+		for (auto it: msgs)
+			if (it) i2p::DeleteI2NPMessage (it);
+		if (ecode)
+        {
+			LogPrint (eLogWarning, "Couldn't send msgs: ", ecode.message ());
+			// we shouldn't call Terminate () here, because HandleReceive takes care
+			// TODO: 'delete this' statement in Terminate () must be eliminated later
+			// Terminate ();
+		}
+		else
+		{	
+			m_NumSentBytes += bytes_transferred;
+			ScheduleTermination (); // reset termination timer
+		}		
+	}	
+
+		
 	void NTCPSession::SendTimeSyncMessage ()
 	{
 		Send (nullptr);
@@ -625,8 +657,7 @@ namespace transport
 
 	void NTCPSession::PostI2NPMessages (std::vector<I2NPMessage *> msgs)
 	{
-		for (auto it: msgs)
-			if (it) Send (it);
+		Send (msgs);
 	}	
 		
 	void NTCPSession::ScheduleTermination ()

NTCPSession.h

@@ -101,7 +101,10 @@ namespace transport
 			bool DecryptNextBlock (const uint8_t * encrypted);	
 		
 			void Send (i2p::I2NPMessage * msg);
+			boost::asio::const_buffers_1 CreateMsgBuffer (I2NPMessage * msg);
 			void HandleSent (const boost::system::error_code& ecode, std::size_t bytes_transferred, i2p::I2NPMessage * msg);
+			void Send (const std::vector<I2NPMessage *>& msgs);
+			void HandleBatchSent (const boost::system::error_code& ecode, std::size_t bytes_transferred, std::vector<I2NPMessage *> msgs);
 			
 			
 			// timer