helper: Add LFID route calculation
Loop-Free In-port Dependent (LFID) route calculation provides a set of loop-free paths.
Basically porting the existing code from https://github.com/schneiderklaus/ndnSIM-routing
Refs: #4985
Change-Id: I1ab25e729851cf2233c3b99be715ba0159cca0c7
diff --git a/helper/lfid/abstract-fib.hpp b/helper/lfid/abstract-fib.hpp
new file mode 100644
index 0000000..b5a118f
--- /dev/null
+++ b/helper/lfid/abstract-fib.hpp
@@ -0,0 +1,164 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2019 Klaus Schneider, The University of Arizona
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Klaus Schneider <klaus@cs.arizona.edu>
+ */
+
+#ifndef LFID_ABS_FIB_H
+#define LFID_ABS_FIB_H
+
+#include <set>
+#include <unordered_map>
+
+#include "ns3/abort.h"
+#include "ns3/ndnSIM/helper/lfid/fib-nexthop.hpp"
+#include "ns3/ptr.h"
+
+namespace ns3 {
+namespace ndn {
+
+class GlobalRouter;
+
+/**
+ * An abstract, lightweight representation of the FIB.
+ */
+class AbstractFib {
+public:
+ using AllNodeFib = std::unordered_map<int, AbstractFib>;
+
+ /**
+ * @param own The GlobalRouter object representing the current router
+ * @param numNodes The total number of nodes in the network
+ */
+ AbstractFib(const Ptr<GlobalRouter> own, int numNodes);
+
+public:
+ // Getters:
+ /**
+ * @return Return set of nexthops per destination
+ */
+ const std::set<FibNextHop>&
+ getNexthops(int dstId) const;
+
+ /**
+ * @return Return set of upward nexthops per destination
+ */
+ const std::set<FibNextHop>&
+ getUpwardNexthops(int dstId) const;
+
+ /**
+ * Make sure that FIB is consistent (each destination has at least one downward nexthop)
+ */
+ void
+ checkFib() const;
+
+ /**
+ * @return Return number nexthops per destination
+ * @pre Also assure that the destination is not equal to the current nodeId.
+ */
+ int
+ numEnabledNhPerDst(int dstId) const
+ {
+ NS_ABORT_UNLESS(dstId != nodeId);
+ return static_cast<int>(getNexthops(dstId).size());
+ }
+
+ int
+ getNodeId() const
+ {
+ return nodeId;
+ }
+
+ Ptr<GlobalRouter>
+ getGR() const;
+
+ std::string
+ getName() const
+ {
+ return nodeName;
+ }
+
+ int
+ getDegree() const
+ {
+ return nodeDegree;
+ }
+
+ int
+ getNumDsts() const
+ {
+ return static_cast<int>(perDstFib.size());
+ }
+
+ bool
+ contains(int dstId) const
+ {
+ return perDstFib.count(dstId) > 0;
+ }
+
+ // Functions for range-based loop:
+ auto
+ begin() const
+ {
+ return perDstFib.cbegin();
+ }
+
+ auto
+ end() const
+ {
+ return perDstFib.cend();
+ }
+
+ // Setters:
+ void
+ insert(int dstId, const FibNextHop& nh);
+
+ size_t
+ erase(int dstId, int nhId);
+
+private:
+ void
+ checkInputs();
+
+ void
+ createEmptyFib();
+
+private:
+ const int nodeId; // Own node id
+ const std::string nodeName; // Own node name
+ const int numberOfNodes;
+ const int nodeDegree;
+ const Ptr<GlobalRouter> ownRouter;
+
+ int upwardCounter;
+ int totalNhCounter;
+
+ // DstId -> set<FibNextHop>
+ std::unordered_map<int, std::set<FibNextHop>> perDstFib;
+ std::unordered_map<int, std::set<FibNextHop>> upwardPerDstFib;
+
+ friend std::ostream&
+ operator<<(std::ostream&, const AbstractFib& fib);
+};
+
+std::ostream&
+operator<<(std::ostream& os, const AbstractFib& fib);
+
+} // namespace ndn
+} // namespace ns-3
+
+#endif // LFID_ABS_FIB_H