premptively build path to selected intro's router every time we don't have it if we get an introset update, on the outbound context

include/llarp/pathbuilder.hpp

@@ -34,6 +34,12 @@ namespace llarp
       void
       BuildOne();
 
+      void
+      Build(const std::vector< RouterContact >& hops);
+
+      bool
+      SelectHops(llarp_nodedb* db, std::vector< RouterContact >& hops);
+
       void
       ManualRebuild(size_t N);
 

include/llarp/service/endpoint.hpp

@@ -271,6 +271,9 @@ namespace llarp
         void
         UpdateIntroSet();
 
+        bool
+        BuildOneAlignedTo(const RouterID& remote);
+
         void
         HandlePathBuilt(path::Path* path);
 

llarp/pathbuilder.cpp

@@ -198,31 +198,44 @@ namespace llarp
     void
     Builder::BuildOne()
     {
-      // select hops
       std::vector< RouterContact > hops;
+      if(SelectHops(router->nodedb, hops))
+        Build(hops);
+    }
+
+    bool
+    Builder::SelectHops(llarp_nodedb* nodedb,
+                        std::vector< RouterContact >& hops)
+    {
       hops.resize(numHops);
       size_t idx = 0;
       while(idx < numHops)
       {
         if(idx == 0)
         {
-          if(!SelectHop(router->nodedb, hops[0], hops[0], 0))
+          if(!SelectHop(nodedb, hops[0], hops[0], 0))
           {
             llarp::LogError("failed to select first hop");
-            return;
+            return false;
           }
         }
         else
         {
-          if(!SelectHop(router->nodedb, hops[idx - 1], hops[idx], idx))
+          if(!SelectHop(nodedb, hops[idx - 1], hops[idx], idx))
           {
             /// TODO: handle this failure properly
             llarp::LogWarn("Failed to select hop ", idx);
-            return;
+            return false;
           }
         }
         ++idx;
       }
+      return true;
+    }
+
+    void
+    Builder::Build(const std::vector< RouterContact >& hops)
+    {
       lastBuild = llarp_time_now_ms();
       // async generate keys
       AsyncPathKeyExchangeContext< Builder >* ctx =

llarp/service/endpoint.cpp

@@ -922,6 +922,8 @@ namespace llarp
       {
         currentIntroSet = *i;
         ShiftIntroduction();
+        if(GetPathByRouter(remoteIntro.router) == nullptr)
+          BuildOneAlignedTo(remoteIntro.router);
       }
       updatingIntroSet = false;
       return true;
@@ -1049,6 +1051,41 @@ namespace llarp
       return true;
     }
 
+    bool
+    Endpoint::OutboundContext::BuildOneAlignedTo(const RouterID& remote)
+    {
+      llarp::LogInfo(Name(), " building path to ", remote);
+      auto nodedb = m_Endpoint->Router()->nodedb;
+      std::vector< RouterContact > hops;
+      hops.resize(numHops);
+      for(size_t hop = 0; hop < numHops; ++hop)
+      {
+        if(hop == 0)
+        {
+          // first hop
+          if(router->NumberOfConnectedRouters())
+          {
+            if(!router->GetRandomConnectedRouter(hops[0]))
+              return false;
+          }
+          else if(!llarp_nodedb_select_random_hop(nodedb, hops[0], hops[0], 0))
+            return false;
+        }
+        else if(hop == numHops - 1)
+        {
+          // last hop
+          if(!llarp_nodedb_get_rc(nodedb, remote, hops[hop]))
+            return false;
+        }
+        // middle hop
+        else if(!llarp_nodedb_select_random_hop(nodedb, hops[hop - 1],
+                                                hops[hop], hop))
+          return false;
+      }
+      Build(hops);
+      return true;
+    }
+
     bool
     Endpoint::OutboundContext::MarkCurrentIntroBad(llarp_time_t now)
     {