table: NameTree::findLongestPrefixMatch predicate

refs #1313

Change-Id: I759c8ddf9bc0fe5b970c979f69131a98b1ef32e4
diff --git a/daemon/table/name-tree-entry.hpp b/daemon/table/name-tree-entry.hpp
index b6f53db..cef42ff 100644
--- a/daemon/table/name-tree-entry.hpp
+++ b/daemon/table/name-tree-entry.hpp
@@ -71,6 +71,9 @@
 
   std::vector<shared_ptr<Entry> >&
   getChildren();
+  
+  bool
+  isEmpty() const;
 
   void
   setFibEntry(shared_ptr<fib::Entry> fib);
@@ -140,6 +143,15 @@
   return m_children;
 }
 
+inline bool
+Entry::isEmpty() const
+{
+  return m_children.empty() &&
+         !static_cast<bool>(m_fibEntry) &&
+         m_pitEntries.empty() &&
+         !static_cast<bool>(m_measurementsEntry);
+}
+
 inline shared_ptr<fib::Entry>
 Entry::getFibEntry() const
 {