From 8878e5c4d126e1f8a14b76180dc56f0db8faaabd Mon Sep 17 00:00:00 2001
From: Jeff Becker <jeff@i2p.rocks>
Date: Fri, 28 Sep 2018 08:22:50 -0400
Subject: [PATCH] redundancy with outbound contexts

have multiple outbound contexts and send on the one that is alive
---
 include/llarp/service/endpoint.hpp | 10 ++++--
 llarp/service/endpoint.cpp         | 58 ++++++++++++++++++++++--------
 2 files changed, 51 insertions(+), 17 deletions(-)

diff --git a/include/llarp/service/endpoint.hpp b/include/llarp/service/endpoint.hpp
index c47083070..ae6eaa98f 100644
--- a/include/llarp/service/endpoint.hpp
+++ b/include/llarp/service/endpoint.hpp
@@ -29,6 +29,8 @@ namespace llarp
 
       static const llarp_time_t INTROSET_PUBLISH_RETRY_INTERVAL = 5000;
 
+      static const size_t MAX_OUTBOUND_CONTEXT_COUNT = 4;
+
       Endpoint(const std::string& nickname, llarp_router* r);
       ~Endpoint();
 
@@ -243,6 +245,10 @@ namespace llarp
         bool
         MarkCurrentIntroBad(llarp_time_t now);
 
+        /// return true if we are ready to send
+        bool
+        ReadyToSend() const;
+
         bool
         ShouldBuildMore() const;
 
@@ -405,8 +411,8 @@ namespace llarp
       std::unordered_map< Address, PendingBufferQueue, Address::Hash >
           m_PendingTraffic;
 
-      std::unordered_map< Address, std::unique_ptr< OutboundContext >,
-                          Address::Hash >
+      std::unordered_multimap< Address, std::unique_ptr< OutboundContext >,
+                               Address::Hash >
           m_RemoteSessions;
 
       std::unordered_multimap< Address, std::unique_ptr< OutboundContext >,
diff --git a/llarp/service/endpoint.cpp b/llarp/service/endpoint.cpp
index c574c29f9..dc7fb1217 100644
--- a/llarp/service/endpoint.cpp
+++ b/llarp/service/endpoint.cpp
@@ -643,22 +643,32 @@ namespace llarp
       Address addr;
       introset.A.CalculateAddress(addr.data());
 
-      // only add new session if it's not there
-      if(m_RemoteSessions.find(addr) == m_RemoteSessions.end())
+      if(m_RemoteSessions.count(addr) >= MAX_OUTBOUND_CONTEXT_COUNT)
       {
-        OutboundContext* ctx = new OutboundContext(introset, this);
-        m_RemoteSessions.insert(
-            std::make_pair(addr, std::unique_ptr< OutboundContext >(ctx)));
-        llarp::LogInfo("Created New outbound context for ", addr.ToString());
+        auto itr = m_RemoteSessions.find(addr);
+
+        auto i = m_PendingServiceLookups.find(addr);
+        if(i != m_PendingServiceLookups.end())
+        {
+          auto f = i->second;
+          m_PendingServiceLookups.erase(i);
+          f(addr, itr->second.get());
+        }
+        return;
       }
 
+      OutboundContext* ctx = new OutboundContext(introset, this);
+      m_RemoteSessions.insert(
+          std::make_pair(addr, std::unique_ptr< OutboundContext >(ctx)));
+      llarp::LogInfo("Created New outbound context for ", addr.ToString());
+
       // inform pending
       auto itr = m_PendingServiceLookups.find(addr);
       if(itr != m_PendingServiceLookups.end())
       {
         auto f = itr->second;
         m_PendingServiceLookups.erase(itr);
-        f(itr->first, m_RemoteSessions.at(addr).get());
+        f(addr, ctx);
       }
     }
 
@@ -917,10 +927,17 @@ namespace llarp
       return true;
     }
 
+    bool
+    Endpoint::OutboundContext::ReadyToSend() const
+    {
+      return GetPathByRouter(remoteIntro.router) != nullptr;
+    }
+
     bool
     Endpoint::SendToOrQueue(const Address& remote, llarp_buffer_t data,
                             ProtocolType t)
     {
+      // inbound converstation
       {
         auto itr = m_AddressToService.find(remote);
         if(itr != m_AddressToService.end())
@@ -974,20 +991,31 @@ namespace llarp
               llarp::LogError("failed to encrypt and sign");
               return false;
             }
-            llarp::LogDebug(Name(), " send ", data.sz, " via ", remoteIntro);
+            llarp::LogDebug(Name(), " send ", data.sz, " via ",
+                            remoteIntro.router);
             return p->SendRoutingMessage(&transfer, Router());
           }
         }
       }
+      // outbound converstation
       if(HasPathToService(remote))
       {
-        llarp::LogDebug(Name(), " has session to ", remote, " sending ",
-                        data.sz, " bytes");
-        auto itr = m_RemoteSessions.find(remote);
-        itr->second->AsyncEncryptAndSendTo(data, t);
-        return true;
+        auto range = m_RemoteSessions.equal_range(remote);
+        auto itr   = range.first;
+        while(itr != range.second)
+        {
+          if(itr->second->ReadyToSend())
+          {
+            itr->second->AsyncEncryptAndSendTo(data, t);
+            return true;
+          }
+          ++itr;
+        }
+        // all paths are not ready?
+        return false;
       }
 
+      // no converstation
       auto itr = m_PendingTraffic.find(remote);
       if(itr == m_PendingTraffic.end())
       {
@@ -1227,8 +1255,8 @@ namespace llarp
         routing::PathTransferMessage transfer(msg, remoteIntro.pathID);
         if(path->SendRoutingMessage(&transfer, m_Endpoint->Router()))
         {
-          llarp::LogInfo("sent data to ", remoteIntro.pathID, " on ",
-                         remoteIntro.router);
+          llarp::LogDebug("sent data to ", remoteIntro.pathID, " on ",
+                          remoteIntro.router);
           lastGoodSend = now;
         }
         else