text: /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
  /**
   * Copyright (c) 2014-2017,  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/>.
   */
  
  #include "cs-policy-priority-fifo.hpp"
  #include "cs.hpp"
  
  namespace nfd {
  namespace cs {
  namespace priority_fifo {
  
  const std::string PriorityFifoPolicy::POLICY_NAME = "priority_fifo";
  NFD_REGISTER_CS_POLICY(PriorityFifoPolicy);
  
  PriorityFifoPolicy::PriorityFifoPolicy()
    : Policy(POLICY_NAME)
  {
  }
  
  PriorityFifoPolicy::~PriorityFifoPolicy()
  {
    for (auto entryInfoMapPair : m_entryInfoMap) {
      delete entryInfoMapPair.second;
    }
  }
  
  void
  PriorityFifoPolicy::doAfterInsert(iterator i)
  {
    this->attachQueue(i);
    this->evictEntries();
  }
  
  void
  PriorityFifoPolicy::doAfterRefresh(iterator i)
  {
    this->detachQueue(i);
    this->attachQueue(i);
  }
  
  void
  PriorityFifoPolicy::doBeforeErase(iterator i)
  {
    this->detachQueue(i);
  }
  
  void
  PriorityFifoPolicy::doBeforeUse(iterator i)
  {
    BOOST_ASSERT(m_entryInfoMap.find(i) != m_entryInfoMap.end());
  }
  
  void
  PriorityFifoPolicy::evictEntries()
  {
    BOOST_ASSERT(this->getCs() != nullptr);
  
    while (this->getCs()->size() > this->getLimit()) {
      this->evictOne();
    }
  }
  
  void
  PriorityFifoPolicy::evictOne()
  {
    BOOST_ASSERT(!m_queues[QUEUE_UNSOLICITED].empty() ||
                 !m_queues[QUEUE_STALE].empty() ||
                 !m_queues[QUEUE_FIFO].empty());
  
    iterator i;
    if (!m_queues[QUEUE_UNSOLICITED].empty()) {
      i = m_queues[QUEUE_UNSOLICITED].front();
    }
    else if (!m_queues[QUEUE_STALE].empty()) {
      i = m_queues[QUEUE_STALE].front();
    }
    else if (!m_queues[QUEUE_FIFO].empty()) {
      i = m_queues[QUEUE_FIFO].front();
    }
  
    this->detachQueue(i);
    this->emitSignal(beforeEvict, i);
  }
  
  void
  PriorityFifoPolicy::attachQueue(iterator i)
  {
    BOOST_ASSERT(m_entryInfoMap.find(i) == m_entryInfoMap.end());
  
    EntryInfo* entryInfo = new EntryInfo();
    if (i->isUnsolicited()) {
      entryInfo->queueType = QUEUE_UNSOLICITED;
    }
    else if (i->isStale()) {
      entryInfo->queueType = QUEUE_STALE;
    }
    else {
      entryInfo->queueType = QUEUE_FIFO;
      entryInfo->moveStaleEventId = scheduler::schedule(i->getData().getFreshnessPeriod(),
                                                        bind(&PriorityFifoPolicy::moveToStaleQueue, this, i));
    }
  
    Queue& queue = m_queues[entryInfo->queueType];
    entryInfo->queueIt = queue.insert(queue.end(), i);
    m_entryInfoMap[i] = entryInfo;
  }
  
  void
  PriorityFifoPolicy::detachQueue(iterator i)
  {
    BOOST_ASSERT(m_entryInfoMap.find(i) != m_entryInfoMap.end());
  
    EntryInfo* entryInfo = m_entryInfoMap[i];
    if (entryInfo->queueType == QUEUE_FIFO) {
      scheduler::cancel(entryInfo->moveStaleEventId);
    }
  
    m_queues[entryInfo->queueType].erase(entryInfo->queueIt);
    m_entryInfoMap.erase(i);
    delete entryInfo;
  }
  
  void
  PriorityFifoPolicy::moveToStaleQueue(iterator i)
  {
    BOOST_ASSERT(m_entryInfoMap.find(i) != m_entryInfoMap.end());
  
    EntryInfo* entryInfo = m_entryInfoMap[i];
    BOOST_ASSERT(entryInfo->queueType == QUEUE_FIFO);
  
    m_queues[QUEUE_FIFO].erase(entryInfo->queueIt);
  
    entryInfo->queueType = QUEUE_STALE;
    Queue& queue = m_queues[QUEUE_STALE];
    entryInfo->queueIt = queue.insert(queue.end(), i);
    m_entryInfoMap[i] = entryInfo;
  }
  
  } // namespace priority_fifo
  } // namespace cs
  } // namespace nfd
  