From 28fdd992c99930f16d7f514084033845754db76a Mon Sep 17 00:00:00 2001
From: Jeff Becker <ampernand@gmail.com>
Date: Mon, 29 Aug 2016 12:09:37 -0400
Subject: [PATCH] add hooks for custom peer selection

---
 TunnelPool.cpp | 12 +++++++++---
 TunnelPool.h   | 17 +++++++++++++++--
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/TunnelPool.cpp b/TunnelPool.cpp
index 119556aa..ba7a86a3 100644
--- a/TunnelPool.cpp
+++ b/TunnelPool.cpp
@@ -15,7 +15,8 @@ namespace tunnel
 {
 	TunnelPool::TunnelPool (int numInboundHops, int numOutboundHops, int numInboundTunnels, int numOutboundTunnels):
 		m_NumInboundHops (numInboundHops), m_NumOutboundHops (numOutboundHops),
-		m_NumInboundTunnels (numInboundTunnels), m_NumOutboundTunnels (numOutboundTunnels), m_IsActive (true)
+		m_NumInboundTunnels (numInboundTunnels), m_NumOutboundTunnels (numOutboundTunnels), m_IsActive (true),
+		m_CustomPeerSelector(nullptr)
 	{
 	}
 
@@ -327,9 +328,14 @@ namespace tunnel
 
 	bool TunnelPool::SelectPeers (std::vector<std::shared_ptr<const i2p::data::IdentityEx> >& peers, bool isInbound)
 	{
-		if (m_ExplicitPeers) return SelectExplicitPeers (peers, isInbound);
 		int numHops = isInbound ? m_NumInboundHops : m_NumOutboundHops;
-		if (numHops <= 0) return true; // peers is empty 
+		// peers is empty
+		if (numHops <= 0) return true; 
+		// custom peer selector in use
+		if (m_CustomPeerSelector) return m_CustomPeerSelector->SelectPeers(peers, numHops, isInbound); 
+		// explicit peers in use
+		if (m_ExplicitPeers) return SelectExplicitPeers (peers, isInbound);
+
 		auto prevHop = i2p::context.GetSharedRouterInfo ();			
 		if(i2p::transport::transports.RoutesRestricted())
 		{
diff --git a/TunnelPool.h b/TunnelPool.h
index b32a554f..bffecba5 100644
--- a/TunnelPool.h
+++ b/TunnelPool.h
@@ -23,6 +23,16 @@ namespace tunnel
 	class InboundTunnel;
 	class OutboundTunnel;
 
+	/** interface for custom tunnel peer selection algorithm */
+	struct ITunnelPeerSelector
+	{
+		typedef std::shared_ptr<const i2p::data::IdentityEx> Peer;
+		typedef std::vector<Peer> TunnelPath;
+		virtual bool SelectPeers(TunnelPath & peers, int hops, bool isInbound) = 0;
+	};
+
+	typedef std::shared_ptr<ITunnelPeerSelector> TunnelPeerSelector;
+  
 	class TunnelPool: public std::enable_shared_from_this<TunnelPool> // per local destination
 	{
 		public:
@@ -55,7 +65,10 @@ namespace tunnel
 
 			int GetNumInboundTunnels () const { return m_NumInboundTunnels; };
 			int GetNumOutboundTunnels () const { return m_NumOutboundTunnels; };
-			
+
+			void SetCustomPeerSelector(TunnelPeerSelector selector);
+			TunnelPeerSelector GetCustomPeerSelector() const { return m_CustomPeerSelector; }
+    
 		private:
 
 			void CreateInboundTunnel ();	
@@ -79,7 +92,7 @@ namespace tunnel
 			mutable std::mutex m_TestsMutex;
 			std::map<uint32_t, std::pair<std::shared_ptr<OutboundTunnel>, std::shared_ptr<InboundTunnel> > > m_Tests;
 			bool m_IsActive;
-
+			TunnelPeerSelector m_CustomPeerSelector;
 		public:
 
 			// for HTTP only