From 62b811c2c150dd502bde36f9960a8ece112c992c Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Sat, 28 Sep 2024 09:49:45 -0400
Subject: [PATCH] use memory pool for SSU2 received packets arrays

---
 libi2pd/SSU2.cpp | 36 ++++++++++++++++++++++++------------
 libi2pd/SSU2.h   | 18 +++++++++++++++++-
 libi2pd/util.h   | 12 ++++++++++--
 3 files changed, 51 insertions(+), 15 deletions(-)

diff --git a/libi2pd/SSU2.cpp b/libi2pd/SSU2.cpp
index d661c33b..ec36d6fb 100644
--- a/libi2pd/SSU2.cpp
+++ b/libi2pd/SSU2.cpp
@@ -368,9 +368,9 @@ namespace transport
 			size_t moreBytes = socket.available (ec);
 			if (!ec && moreBytes)
 			{
-				std::vector<Packet *> packets;
-				packets.push_back (packet);
-				while (moreBytes && packets.size () < SSU2_MAX_NUM_PACKETS_PER_BATCH)
+				auto packets = m_PacketsArrayPool.AcquireMt ();
+				packets->AddPacket (packet);
+				while (moreBytes && packets->numPackets < SSU2_MAX_NUM_PACKETS_PER_BATCH)
 				{
 					packet = m_PacketsPool.AcquireMt ();
 					packet->len = socket.receive_from (boost::asio::buffer (packet->buf, SSU2_MAX_PACKET_SIZE), packet->from, 0, ec);
@@ -378,7 +378,13 @@ namespace transport
 					{
 						i2p::transport::transports.UpdateReceivedBytes (packet->len);
 						if (packet->len >= SSU2_MIN_RECEIVED_PACKET_SIZE)
-							packets.push_back (packet);
+						{	
+							if (!packets->AddPacket (packet))
+							{
+								LogPrint (eLogError, "SSU2: Received packets array is full");
+								m_PacketsPool.ReleaseMt (packet);
+							}	
+						}	
 						else // drop too short packets
 							m_PacketsPool.ReleaseMt (packet);
 						moreBytes = socket.available(ec);
@@ -391,10 +397,7 @@ namespace transport
 						break;
 					}
 				}
-				GetService ().post ([packets = std::move (packets), this]() mutable
-					{
-						HandleReceivedPackets (std::move (packets));
-					});
+				GetService ().post (std::bind (&SSU2Server::HandleReceivedPackets, this, packets));
 			}
 			else
 				GetService ().post (std::bind (&SSU2Server::HandleReceivedPacket, this, packet));
@@ -438,15 +441,23 @@ namespace transport
 		}
 	}
 
-	void SSU2Server::HandleReceivedPackets (std::vector<Packet *>&& packets)
+	void SSU2Server::HandleReceivedPackets (Packets * packets)
 	{
+		if (!packets) return;
 		if (m_IsThroughProxy)
-			for (auto& packet: packets)
+			for (size_t i = 0; i < packets->numPackets; i++)
+			{
+				auto& packet = (*packets)[i];
 				ProcessNextPacketFromProxy (packet->buf, packet->len);
+			}	
 		else
-			for (auto& packet: packets)
+			for (size_t i = 0; i < packets->numPackets; i++)
+			{
+				auto& packet = (*packets)[i];
 				ProcessNextPacket (packet->buf, packet->len, packet->from);
-		m_PacketsPool.ReleaseMt (std::move (packets));
+			}	
+		m_PacketsPool.ReleaseMt (packets->data (), packets->numPackets);
+		m_PacketsArrayPool.ReleaseMt (packets);
 		if (m_LastSession && m_LastSession->GetState () != eSSU2SessionStateTerminated)
 			m_LastSession->FlushData ();
 	}
@@ -1098,6 +1109,7 @@ namespace transport
 			}	
 			
 			m_PacketsPool.CleanUpMt ();
+			m_PacketsArrayPool.CleanUpMt ();
 			m_SentPacketsPool.CleanUp ();
 			m_IncompleteMessagesPool.CleanUp ();
 			m_FragmentsPool.CleanUp ();
diff --git a/libi2pd/SSU2.h b/libi2pd/SSU2.h
index 36b946c5..97ef879f 100644
--- a/libi2pd/SSU2.h
+++ b/libi2pd/SSU2.h
@@ -12,6 +12,7 @@
 #include <unordered_map>
 #include <unordered_set>
 #include <vector>
+#include <array>
 #include <mutex>
 #include <random>
 #include "util.h"
@@ -51,6 +52,20 @@ namespace transport
 			boost::asio::ip::udp::endpoint from;
 		};
 
+		struct Packets: public std::array<Packet *, SSU2_MAX_NUM_PACKETS_PER_BATCH>
+		{
+			size_t numPackets = 0;
+			bool AddPacket (Packet *p) 
+			{
+				if (p && numPackets < size ()) 
+				{ 
+					data()[numPackets] = p; numPackets++; 
+					return true;
+				} 
+				return false;
+			} 
+		};
+	
 		class ReceiveService: public i2p::util::RunnableService
 		{
 			public:
@@ -127,7 +142,7 @@ namespace transport
 			void HandleReceivedFrom (const boost::system::error_code& ecode, size_t bytes_transferred,
 				Packet * packet, boost::asio::ip::udp::socket& socket);
 			void HandleReceivedPacket (Packet * packet);
-			void HandleReceivedPackets (std::vector<Packet *>&& packets);
+			void HandleReceivedPackets (Packets * packets);
 			void ProcessNextPacket (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint);
 
 			void ScheduleTermination ();
@@ -172,6 +187,7 @@ namespace transport
 			std::unordered_map<uint32_t, std::weak_ptr<SSU2Session> > m_Relays; // we are introducer, relay tag -> session
 			std::list<std::pair<i2p::data::IdentHash, uint32_t> > m_Introducers, m_IntroducersV6; // introducers we are connected to
 			i2p::util::MemoryPoolMt<Packet> m_PacketsPool;
+			i2p::util::MemoryPoolMt<Packets> m_PacketsArrayPool;
 			i2p::util::MemoryPool<SSU2SentPacket> m_SentPacketsPool;
 			i2p::util::MemoryPool<SSU2IncompleteMessage> m_IncompleteMessagesPool;
 			i2p::util::MemoryPool<SSU2IncompleteMessage::Fragment> m_FragmentsPool;
diff --git a/libi2pd/util.h b/libi2pd/util.h
index dbc69c25..e39a9259 100644
--- a/libi2pd/util.h
+++ b/libi2pd/util.h
@@ -131,14 +131,22 @@ namespace util
 				this->Release (t);
 			}
 
+			void ReleaseMt (T * * arr, size_t num)
+			{
+				if (!arr || !num) return;
+				std::lock_guard<std::mutex> l(m_Mutex);
+				for (size_t i = 0; i < num; i++)
+					this->Release (arr[i]);
+			}	
+			
 			template<template<typename, typename...>class C, typename... R>
-			void ReleaseMt(C<T *, R...>&& c)
+			void ReleaseMt(const C<T *, R...>& c)
 			{
 				std::lock_guard<std::mutex> l(m_Mutex);
 				for (auto& it: c)
 					this->Release (it);
 			}
-
+			
 			template<typename... TArgs>
 			std::shared_ptr<T> AcquireSharedMt (TArgs&&... args)
 			{