function for updating CacheEntry timestamp and mark as verified

Hash2Pub/src/Hash2Pub/DHTProtocol.hs

@@ -196,3 +196,14 @@ deleteCacheEntry = Map.update modifier
     modifier (ProxyEntry idPointer _) = Just (ProxyEntry idPointer Nothing)
     modifier NodeEntry {} = Nothing
 
+-- | Mark a cache entry as verified after pinging it, possibly bumping its timestamp.
+markCacheEntryAsVerified :: Maybe POSIXTime     -- ^ the (current) timestamp to be
+                                                -- given to the entry, or Nothing
+                         -> NodeID              -- ^ which node to mark
+                         -> NodeCache           -- ^ current node cache
+                         -> NodeCache           -- ^ new NodeCache with the updated entry
+markCacheEntryAsVerified timestamp = Map.adjust adjustFunc
+    where
+        adjustFunc (NodeEntry _ ns ts) = NodeEntry True ns $ fromMaybe ts timestamp
+        adjustFunc (ProxyEntry _ (Just entry)) = adjustFunc entry
+        adjustFunc entry = entry