NFD

Longest prefix match function of FIB is currently equivalent to:

1. let nte be the longest prefix match NameTree entry for name
2. if nte is nullptr, return the root FIB entry
3. if nte contains a FIB entry, return this FIB entry
4. let nte be its parent, goto step 2

This design assumes the NameTree is hashtable. It would be inefficient if NameTree is a trie.

This task moves to an alternate design:

• NameTree::findLongestPrefixMatch should take a predicate that determines whether an entry is acceptable NameTree::findLongestPrefixMatch(const Name& name, function<bool(name_tree::entry)> predicate);
• Current NameTree should implement the "walk up" algorithm in this method
• Fib::findLongestPrefixMatch and Measurements::findLongestPrefixMatch supply a predicate that checks whether FIB/Measurements entry exists