dht: don't send unnecessary findNode

src/dht.cpp

@@ -382,7 +382,7 @@ Dht::searchSendGetValues(Sp<Search> sr, SearchNode* pn, bool update)
         }
 
         if (sr->callbacks.empty()) { /* 'find_node' request */
-            if (not n)
+            if (not n or n->isSynced(now))
                 return nullptr;
 
             /* if (logger_)
@@ -491,9 +491,9 @@ void Dht::searchSendAnnounceValue(const Sp<Search>& sr) {
                         sr->id.toString().c_str(), sn->node->toString().c_str(), a.value->id);
                 sn->acked[a.value->id] = {
                     network_engine.sendRefreshValue(sn->node, sr->id, a.value->id, sn->token, onDone,
-                    [this, ws, node=sn->node, v=a.value, 
-                     onDone, 
-                     onExpired, 
+                    [this, ws, node=sn->node, v=a.value,
+                     onDone,
+                     onExpired,
                      created = a.permanent ? time_point::max() : a.created,
                      next_refresh_time
                     ](const net::Request& /*req*/, net::DhtProtocolException&& e){
@@ -591,7 +591,7 @@ Dht::searchSynchedNodeListen(const Sp<Search>& sr, SearchNode& n)
     std::weak_ptr<Search> ws = sr;
     for (const auto& l : sr->listeners) {
         const auto& query = l.second.query;
-        
+
         auto r = n.listenStatus.find(query);
         if (n.getListenTime(r, listenExp) > scheduler.time())
             continue;
@@ -725,7 +725,7 @@ Dht::searchStep(Sp<Search> sr)
 
     while (sr->currentlySolicitedNodeCount() < MAX_REQUESTED_SEARCH_NODES and searchSendGetValues(sr));
 
-    
+
     if (sr->getNumberOfConsecutiveBadNodes() >= std::min<size_t>(sr->nodes.size(), SEARCH_MAX_BAD_NODES))
     {
         if (logger_)
@@ -2528,7 +2528,7 @@ Dht::saveState(const std::string& path) const
     state.nodes = exportNodes();
     state.values = exportValues();
     std::ofstream file(path);
-    msgpack::pack(file, state);    
+    msgpack::pack(file, state);
 }
 
 void