fib: fix route unregister bug during update

refs: #5179

Change-Id: I19952ebcb0c78c405f3d820694a7b0f1cf7a3fe6
diff --git a/src/route/fib.cpp b/src/route/fib.cpp
index 1004889..2d34a36 100644
--- a/src/route/fib.cpp
+++ b/src/route/fib.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020,  The University of Memphis,
+ * Copyright (c) 2014-2021,  The University of Memphis,
  *                           Regents of the University of California
  *
  * This file is part of NLSR (Named-data Link State Routing).
@@ -54,7 +54,7 @@
 
   // Only unregister the prefix if it ISN'T a neighbor.
   if (it != m_table.end() && isNotNeighbor((it->second).name)) {
-    for (const auto& nexthop : (it->second).nexthopList.getNextHops()) {
+    for (const auto& nexthop : (it->second).nexthopSet) {
       unregisterPrefix((it->second).name, nexthop.getConnectingFaceUri());
     }
     m_table.erase(it);
@@ -62,16 +62,17 @@
 }
 
 void
-Fib::addNextHopsToFibEntryAndNfd(FibEntry& entry, const NexthopList& hopsToAdd)
+Fib::addNextHopsToFibEntryAndNfd(FibEntry& entry, const NextHopsUriSortedSet& hopsToAdd)
 {
   const ndn::Name& name = entry.name;
 
   bool shouldRegister = isNotNeighbor(name);
 
-  for (const auto& hop : hopsToAdd.getNextHops())
+  for (const auto& hop : hopsToAdd)
   {
     // Add nexthop to FIB entry
-    entry.nexthopList.addNextHop(hop);
+    NLSR_LOG_DEBUG("Adding " << hop.getConnectingFaceUri() << " to " << entry.name);
+    entry.nexthopSet.addNextHop(hop);
 
     if (shouldRegister) {
       // Add nexthop to NDN-FIB
@@ -92,7 +93,7 @@
   // the length of the list of all next hops.
   unsigned int maxFaces = getNumberOfFacesForName(allHops);
 
-  NexthopList hopsToAdd;
+  NextHopsUriSortedSet hopsToAdd;
   unsigned int nFaces = 0;
 
   // Create a list of next hops to be installed with length == maxFaces
@@ -129,10 +130,11 @@
     FibEntry& entry = (entryIt->second);
     addNextHopsToFibEntryAndNfd(entry, hopsToAdd);
 
-    std::set<NextHop, NextHopComparator> hopsToRemove;
-    std::set_difference(entry.nexthopList.begin(), entry.nexthopList.end(),
+    std::set<NextHop, NextHopUriSortedComparator> hopsToRemove;
+    std::set_difference(entry.nexthopSet.begin(), entry.nexthopSet.end(),
                         hopsToAdd.begin(), hopsToAdd.end(),
-                        std::inserter(hopsToRemove, hopsToRemove.end()), NextHopComparator());
+                        std::inserter(hopsToRemove, hopsToRemove.begin()),
+                        NextHopUriSortedComparator());
 
     bool isUpdatable = isNotNeighbor(entry.name);
     // Remove the uninstalled next hops from NFD and FIB entry
@@ -141,7 +143,7 @@
         unregisterPrefix(entry.name, hop.getConnectingFaceUri());
       }
       NLSR_LOG_DEBUG("Removing " << hop.getConnectingFaceUri() << " from " << entry.name);
-      entry.nexthopList.removeNextHop(hop);
+      entry.nexthopSet.removeNextHop(hop);
     }
 
     // Increment sequence number
@@ -161,7 +163,7 @@
 {
   NLSR_LOG_DEBUG("Clean called");
   for (const auto& it : m_table) {
-    for (const auto& hop : it.second.nexthopList.getNextHops()) {
+    for (const auto& hop : it.second.nexthopSet) {
       unregisterPrefix(it.second.name, hop.getConnectingFaceUri());
     }
   }
@@ -339,7 +341,7 @@
 
   entry.seqNo += 1;
 
-  for (const NextHop& hop : entry.nexthopList) {
+  for (const NextHop& hop : entry.nexthopSet) {
     registerPrefix(entry.name,
                    ndn::FaceUri(hop.getConnectingFaceUri()),
                    hop.getRouteCostAsAdjustedInteger(),
@@ -355,9 +357,9 @@
 {
   NLSR_LOG_DEBUG("-------------------FIB-----------------------------");
   for (const auto& entry : m_table) {
-    NLSR_LOG_DEBUG("Name Prefix: " << entry.second.name);
+    NLSR_LOG_DEBUG("Name prefix: "  << entry.first);
     NLSR_LOG_DEBUG("Seq No: " <<  entry.second.seqNo);
-    NLSR_LOG_DEBUG(entry.second.nexthopList);
+    NLSR_LOG_DEBUG("Nexthop List: \n" << entry.second.nexthopSet);
   }
 }
 
diff --git a/src/route/fib.hpp b/src/route/fib.hpp
index e8f8a40..25b5956 100644
--- a/src/route/fib.hpp
+++ b/src/route/fib.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020,  The University of Memphis,
+ * Copyright (c) 2014-2021,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -31,11 +31,13 @@
 
 namespace nlsr {
 
+typedef NexthopListT<NextHopUriSortedComparator> NextHopsUriSortedSet;
+
 struct FibEntry {
   ndn::Name name;
   ndn::scheduler::ScopedEventId refreshEventId;
   int32_t seqNo = 1;
-  NexthopList nexthopList;
+  NextHopsUriSortedSet nexthopSet;
 };
 
 typedef std::function<void(FibEntry&)> afterRefreshCallback;
@@ -153,7 +155,7 @@
    * \sa Fib::removeOldNextHopsFromFibEntryAndNfd
    */
   void
-  addNextHopsToFibEntryAndNfd(FibEntry& entry, const NexthopList& hopsToAdd);
+  addNextHopsToFibEntryAndNfd(FibEntry& entry, const NextHopsUriSortedSet& hopsToAdd);
 
   unsigned int
   getNumberOfFacesForName(const NexthopList& nextHopList);
diff --git a/src/route/nexthop-list.cpp b/src/route/nexthop-list.cpp
deleted file mode 100644
index 7ab1352..0000000
--- a/src/route/nexthop-list.cpp
+++ /dev/null
@@ -1,102 +0,0 @@
-/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/*
- * Copyright (c) 2014-2020,  The University of Memphis,
- *                           Regents of the University of California,
- *                           Arizona Board of Regents.
- *
- * This file is part of NLSR (Named-data Link State Routing).
- * See AUTHORS.md for complete list of NLSR authors and contributors.
- *
- * NLSR 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.
- *
- * NLSR 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
- * NLSR, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "nexthop-list.hpp"
-#include "common.hpp"
-#include "nexthop.hpp"
-
-#include <ndn-cxx/util/ostream-joiner.hpp>
-
-namespace nlsr {
-
-static bool
-nexthopAddCompare(const NextHop& nh1, const NextHop& nh2)
-{
-  return nh1.getConnectingFaceUri() == nh2.getConnectingFaceUri();
-}
-
-static bool
-nexthopRemoveCompare(const NextHop& nh1, const NextHop& nh2)
-{
-  return (nh1.getConnectingFaceUri() == nh2.getConnectingFaceUri() &&
-          nh1.getRouteCostAsAdjustedInteger() == nh2.getRouteCostAsAdjustedInteger()) ;
-}
-
-bool
-operator==(const NexthopList& lhs, const NexthopList& rhs)
-{
-  if (lhs.size() != rhs.size()) {
-    return false;
-  }
-
-  NexthopList slhs = lhs;
-  NexthopList srhs = rhs;
-
-  for (struct {std::set<NextHop>::iterator lItr;
-    std::set<NextHop>::iterator rItr;} pair = {slhs.begin(), srhs.begin()};
-       (pair.lItr != slhs.end() || pair.rItr != srhs.end());
-       pair.rItr++, pair.lItr++) {
-    if (!((*pair.lItr) == (*pair.rItr))) {
-      return false;
-    }
-  }
-  return true;
-}
-
-bool
-operator!=(const NexthopList& lhs, const NexthopList& rhs)
-{
-  return !(lhs == rhs);
-}
-
-std::ostream&
-operator<<(std::ostream& os, const NexthopList& nhl)
-{
-  os << "    ";
-  std::copy(nhl.cbegin(), nhl.cend(), ndn::make_ostream_joiner(os, "\n    "));
-  return os;
-}
-
-void
-NexthopList::addNextHop(const NextHop& nh)
-{
-  auto it = std::find_if(m_nexthopList.begin(), m_nexthopList.end(),
-                         std::bind(&nexthopAddCompare, _1, nh));
-  if (it == m_nexthopList.end()) {
-    m_nexthopList.insert(nh);
-  }
-  else if (it->getRouteCost() > nh.getRouteCost()) {
-    removeNextHop(*it);
-    m_nexthopList.insert(nh);
-  }
-}
-
-void
-NexthopList::removeNextHop(const NextHop& nh)
-{
-  auto it = std::find_if(m_nexthopList.begin(), m_nexthopList.end(),
-                         std::bind(&nexthopRemoveCompare, _1, nh));
-  if (it != m_nexthopList.end()) {
-    m_nexthopList.erase(it);
-  }
-}
-
-} // namespace nlsr
diff --git a/src/route/nexthop-list.hpp b/src/route/nexthop-list.hpp
index 537448e..98e5760 100644
--- a/src/route/nexthop-list.hpp
+++ b/src/route/nexthop-list.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020,  The University of Memphis,
+ * Copyright (c) 2014-2021,  The University of Memphis,
  *                           Regents of the University of California
  *
  * This file is part of NLSR (Named-data Link State Routing).
@@ -25,6 +25,8 @@
 #include "adjacent.hpp"
 
 #include <ndn-cxx/face.hpp>
+#include <ndn-cxx/util/ostream-joiner.hpp>
+
 #include <set>
 
 namespace nlsr {
@@ -44,10 +46,31 @@
   }
 };
 
-class NexthopList
+struct NextHopUriSortedComparator {
+  bool
+  operator() (const NextHop& nh1, const NextHop& nh2) const {
+    return nh1.getConnectingFaceUri() < nh2.getConnectingFaceUri();
+  }
+};
+
+static inline bool
+nexthopAddCompare(const NextHop& nh1, const NextHop& nh2)
+{
+  return nh1.getConnectingFaceUri() == nh2.getConnectingFaceUri();
+}
+
+static inline bool
+nexthopRemoveCompare(const NextHop& nh1, const NextHop& nh2)
+{
+  return (nh1.getConnectingFaceUri() == nh2.getConnectingFaceUri() &&
+          nh1.getRouteCostAsAdjustedInteger() == nh2.getRouteCostAsAdjustedInteger()) ;
+}
+
+template<typename T = NextHopComparator>
+class NexthopListT
 {
 public:
-  NexthopList() = default;
+  NexthopListT() = default;
 
   /*! \brief Adds a next hop to the list.
     \param nh The next hop.
@@ -57,7 +80,18 @@
     hop's route cost is updated.
   */
   void
-  addNextHop(const NextHop& nh);
+  addNextHop(const NextHop& nh)
+  {
+    auto it = std::find_if(m_nexthopList.begin(), m_nexthopList.end(),
+                           std::bind(&nexthopAddCompare, _1, nh));
+    if (it == m_nexthopList.end()) {
+      m_nexthopList.insert(nh);
+    }
+    else if (it->getRouteCost() > nh.getRouteCost()) {
+      removeNextHop(*it);
+      m_nexthopList.insert(nh);
+    }
+  }
 
   /*! \brief Remove a next hop from the Next Hop list
       \param nh The NextHop we want to remove.
@@ -65,7 +99,14 @@
     The next hop gets removed only if both next hop face and route cost are same.
   */
   void
-  removeNextHop(const NextHop& nh);
+  removeNextHop(const NextHop& nh)
+  {
+    auto it = std::find_if(m_nexthopList.begin(), m_nexthopList.end(),
+                           std::bind(&nexthopRemoveCompare, _1, nh));
+    if (it != m_nexthopList.end()) {
+      m_nexthopList.erase(it);
+    }
+  }
 
   size_t
   size() const
@@ -79,24 +120,25 @@
     m_nexthopList.clear();
   }
 
-  const std::set<NextHop, NextHopComparator>&
+  const std::set<NextHop, T>&
   getNextHops() const
   {
     return m_nexthopList;
   }
 
-  typedef std::set<NextHop, NextHopComparator>::iterator iterator;
-  typedef std::set<NextHop, NextHopComparator>::const_iterator const_iterator;
-  typedef std::set<NextHop, NextHopComparator>::reverse_iterator reverse_iterator;
+  typedef T value_type;
+  typedef typename std::set<NextHop, T>::iterator iterator;
+  typedef typename std::set<NextHop, T>::const_iterator const_iterator;
+  typedef typename std::set<NextHop, T>::reverse_iterator reverse_iterator;
 
   iterator
-  begin()
+  begin() const
   {
     return m_nexthopList.begin();
   }
 
   iterator
-  end()
+  end() const
   {
     return m_nexthopList.end();
   }
@@ -126,20 +168,33 @@
   }
 
 private:
-  std::set<NextHop, NextHopComparator> m_nexthopList;
+  std::set<NextHop, T> m_nexthopList;
 };
 
-bool
-operator==(NexthopList& lhs, NexthopList& rhs);
+typedef NexthopListT<> NexthopList;
 
+template<typename T>
 bool
-operator==(const NexthopList& lhs, const NexthopList& rhs);
+operator==(const NexthopListT<T>& lhs, const NexthopListT<T>& rhs)
+{
+  return lhs.getNextHops() == rhs.getNextHops();
+}
 
+template<typename T>
 bool
-operator!=(const NexthopList& lhs, const NexthopList& rhs);
+operator!=(const NexthopListT<T>& lhs, const NexthopListT<T>& rhs)
+{
+  return !(lhs == rhs);
+}
 
+template<typename T>
 std::ostream&
-operator<<(std::ostream& os, const NexthopList& nhl);
+operator<<(std::ostream& os, const NexthopListT<T>& nhl)
+{
+  os << "    ";
+  std::copy(nhl.cbegin(), nhl.cend(), ndn::make_ostream_joiner(os, "\n    "));
+  return os;
+}
 
 } // namespace nlsr