nexthop-list.hpp

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * 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).
 * 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/>.
 */
 
#ifndef NLSR_NEXTHOP_LIST_HPP
#define NLSR_NEXTHOP_LIST_HPP
 
#include "nexthop.hpp"
#include "adjacent.hpp"
 
#include <ndn-cxx/face.hpp>
#include <ndn-cxx/util/ostream-joiner.hpp>
 
#include <set>
 
namespace nlsr {
 
struct NextHopComparator {
  bool
  operator() (const NextHop& nh1, const NextHop& nh2) const {
    if (nh1.getRouteCostAsAdjustedInteger() < nh2.getRouteCostAsAdjustedInteger()) {
      return true;
    }
    else if (nh1.getRouteCostAsAdjustedInteger() == nh2.getRouteCostAsAdjustedInteger()) {
      return nh1.getConnectingFaceUri() < nh2.getConnectingFaceUri();
    }
    else {
      return false;
    }
  }
};
 
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:
  NexthopListT() = default;
 
  void
  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
  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
  {
    return m_nexthopList.size();
  }
 
  void
  clear()
  {
    m_nexthopList.clear();
  }
 
  const std::set<NextHop, T>&
  getNextHops() const
  {
    return m_nexthopList;
  }
 
  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() const
  {
    return m_nexthopList.begin();
  }
 
  iterator
  end() const
  {
    return m_nexthopList.end();
  }
 
  const_iterator
  cbegin() const
  {
    return m_nexthopList.begin();
  }
 
  const_iterator
  cend() const
  {
    return m_nexthopList.end();
  }
 
  reverse_iterator
  rbegin() const
  {
    return m_nexthopList.rbegin();
  }
 
  reverse_iterator
  rend() const
  {
    return m_nexthopList.rend();
  }
 
private:
  std::set<NextHop, T> m_nexthopList;
};
 
typedef NexthopListT<> NexthopList;
 
template<typename T>
bool
operator==(const NexthopListT<T>& lhs, const NexthopListT<T>& rhs)
{
  return lhs.getNextHops() == rhs.getNextHops();
}
 
template<typename T>
bool
operator!=(const NexthopListT<T>& lhs, const NexthopListT<T>& rhs)
{
  return !(lhs == rhs);
}
 
template<typename T>
std::ostream&
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
 
#endif // NLSR_NEXTHOP_LIST_HPP