table: delete PIT in-record and out-record when face is destroyed

refs #3685

Change-Id: I3c20417c9a30db69c90c9d59a30af1529bc1f98e
diff --git a/daemon/table/cleanup.hpp b/daemon/table/cleanup.hpp
new file mode 100644
index 0000000..3c84482
--- /dev/null
+++ b/daemon/table/cleanup.hpp
@@ -0,0 +1,52 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2016,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef NFD_DAEMON_TABLE_CLEANUP_HPP
+#define NFD_DAEMON_TABLE_CLEANUP_HPP
+
+#include "name-tree.hpp"
+#include "fib.hpp"
+#include "pit.hpp"
+
+namespace nfd {
+
+/** \brief cleanup tables when a face is destroyed
+ *
+ *  This function enumerates the NameTree, calls Fib::removeNextHop for each FIB entry,
+ *  calls Pit::deleteInOutRecords for each PIT entry, and finally
+ *  deletes any name tree entries that have become empty.
+ *
+ *  \note It's a design choice to let Fib and Pit classes decide what to do with each entry.
+ *        This function is only responsible for implementing the enumeration procedure.
+ *        The benefit of having this function instead of doing the enumeration in Fib and Pit
+ *        classes is to perform both FIB and PIT cleanups in one pass of NameTree enumeration,
+ *        so as to reduce performance overhead.
+ */
+void
+cleanupOnFaceRemoval(NameTree& nt, Fib& fib, Pit& pit, const Face& face);
+
+} // namespace nfd
+
+#endif // NFD_DAEMON_TABLE_CLEANUP_HPP