src/route/nexthop-list.cpp

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
 * Copyright (c) 2014-2016,  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 <iostream>

#include "common.hpp"
#include "nexthop-list.hpp"
#include "nexthop.hpp"
#include "logger.hpp"

namespace nlsr {

INIT_LOGGER("NexthopList");

using namespace std;

static bool
nexthopCompare(NextHop& nh1, NextHop& nh2)
{
  return nh1.getConnectingFaceUri() == nh2.getConnectingFaceUri();
}

static bool
nexthopRemoveCompare(NextHop& nh1, NextHop& nh2)
{
  return (nh1.getConnectingFaceUri() == nh2.getConnectingFaceUri() &&
          nh1.getRouteCostAsAdjustedInteger() == nh2.getRouteCostAsAdjustedInteger()) ;
}

static bool
nextHopSortingComparator(const NextHop& nh1, const NextHop& nh2)
{
  if (nh1.getRouteCostAsAdjustedInteger() < nh2.getRouteCostAsAdjustedInteger()) {
    return true;
  }
  else if (nh1.getRouteCostAsAdjustedInteger() == nh2.getRouteCostAsAdjustedInteger()) {
    return nh1.getConnectingFaceUri() < nh2.getConnectingFaceUri();
  }
  else {
    return false;
  }
}

/**
Add next hop to the Next Hop list
If next hop is new it is added
If next hop already exists in next
hop list then updates the route
cost with new next hop's route cost
*/

void
NexthopList::addNextHop(NextHop& nh)
{
  std::list<NextHop>::iterator it = std::find_if(m_nexthopList.begin(),
                                                 m_nexthopList.end(),
                                                 ndn::bind(&nexthopCompare, _1, nh));
  if (it == m_nexthopList.end()) {
    m_nexthopList.push_back(nh);
    return;
  }
  if ((*it).getRouteCost() > nh.getRouteCost()) {
    (*it).setRouteCost(nh.getRouteCost());
  }
}

/**
Remove a next hop only if both next hop face and route cost are same

*/

void
NexthopList::removeNextHop(NextHop& nh)
{
  std::list<NextHop>::iterator it = std::find_if(m_nexthopList.begin(),
                                                 m_nexthopList.end(),
                                                 ndn::bind(&nexthopRemoveCompare, _1, nh));
  if (it != m_nexthopList.end()) {
    m_nexthopList.erase(it);
  }
}

void
NexthopList::sort()
{
  m_nexthopList.sort(nextHopSortingComparator);
}

void
NexthopList::writeLog()
{
  int i = 1;
  sort();
  for (std::list<NextHop>::iterator it = m_nexthopList.begin();
       it != m_nexthopList.end() ; it++, i++) {
    _LOG_DEBUG("Nexthop " << i << ": " << (*it).getConnectingFaceUri()
               << " Route Cost: " << (*it).getRouteCost());
  }
}

} // namespace nlsr