reuse NTCP2 frame buffers

libi2pd/NTCP2.cpp

@@ -143,7 +143,7 @@ namespace transport
 		m_Server (server), m_Socket (m_Server.GetService ()), 
 		m_IsEstablished (false), m_IsTerminated (false),
 		m_SessionRequestBuffer (nullptr), m_SessionCreatedBuffer (nullptr), m_SessionConfirmedBuffer (nullptr),
-		m_NextReceivedBuffer (nullptr), m_NextSendBuffer (nullptr),
+		m_NextReceivedLen (0), m_NextReceivedBuffer (nullptr), m_NextSendBuffer (nullptr),
 		m_ReceiveSequenceNumber (0), m_SendSequenceNumber (0), m_IsSending (false)
 	{
 		m_Establisher.reset (new NTCP2Establisher);
@@ -647,11 +647,15 @@ namespace transport
 		}
 		else
 		{
-			i2p::crypto::Siphash<8> (m_ReceiveIV, m_ReceiveIV, 8, m_ReceiveSipKey); 
+			i2p::crypto::Siphash<8> (m_ReceiveIV, m_ReceiveIV, 8, m_ReceiveSipKey);
+			uint16_t oldLen = m_NextReceivedLen; 
 			m_NextReceivedLen = be16toh (m_NextReceivedLen ^ bufbe16toh(m_ReceiveIV));
 			LogPrint (eLogDebug, "NTCP2: received length ", m_NextReceivedLen);
-			delete[] m_NextReceivedBuffer;
-			m_NextReceivedBuffer = new uint8_t[m_NextReceivedLen];
+			if (m_NextReceivedLen > oldLen)
+			{
+				delete[] m_NextReceivedBuffer;
+				m_NextReceivedBuffer = new uint8_t[m_NextReceivedLen];
+			}
 			Receive ();
 		}
 	}
@@ -784,7 +788,8 @@ namespace transport
 	{
 		if (!m_SendQueue.empty ())
 		{
-			uint8_t * payload = new uint8_t[NTCP2_UNENCRYPTED_FRAME_MAX_SIZE];
+			auto buf = m_Server.NewNTCP2FrameBuffer ();
+			uint8_t * payload = buf->data ();
 			size_t s = 0;
 			// add I2NP blocks
 			while (!m_SendQueue.empty ())
@@ -815,7 +820,7 @@ namespace transport
 			s += paddingSize;
 			// send
 			SendNextFrame (payload, s);
-			delete[] payload;
+			m_Server.DeleteNTCP2FrameBuffer (buf);
 		} 
 	}
 

libi2pd/NTCP2.h

@@ -6,8 +6,10 @@
 #include <thread>
 #include <list>
 #include <map>
+#include <array>
 #include <openssl/bn.h>
 #include <boost/asio.hpp>
+#include "util.h"
 #include "RouterInfo.h"
 #include "TransportSession.h"
 
@@ -57,6 +59,7 @@ namespace transport
 	};		
 	
 
+	typedef std::array<uint8_t, NTCP2_UNENCRYPTED_FRAME_MAX_SIZE> NTCP2FrameBuffer;
 	struct NTCP2Establisher
 	{
 		NTCP2Establisher ();
@@ -187,6 +190,9 @@ namespace transport
 		
 			void Connect(const boost::asio::ip::address & address, uint16_t port, std::shared_ptr<NTCP2Session> conn);
 
+			NTCP2FrameBuffer * NewNTCP2FrameBuffer () { return m_NTCP2FrameBuffersPool.Acquire(); }
+			void DeleteNTCP2FrameBuffer (NTCP2FrameBuffer * buf) { return m_NTCP2FrameBuffersPool.Release(buf); }
+
 		private:
 
 			void Run ();
@@ -210,6 +216,8 @@ namespace transport
 			std::map<i2p::data::IdentHash, std::shared_ptr<NTCP2Session> > m_NTCP2Sessions; 
 			std::list<std::shared_ptr<NTCP2Session> > m_PendingIncomingSessions;
 
+			i2p::util::MemoryPool<NTCP2FrameBuffer> m_NTCP2FrameBuffersPool;
+
 		public:
 
 			// for HTTP/I2PControl