nsync/sync-interest-table.cc

/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2012 University of California, Los Angeles
 *
 * 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: Zhenkai Zhu <zhenkai@cs.ucla.edu>
 *         Chaoyi Bian <bcy@pku.edu.cn>
 *         Alexander Afanasyev <alexander.afanasyev@ucla.edu>
 */

#include "sync-interest-table.h"
#include "sync-logging.h"
using namespace std;

INIT_LOGGER("SyncInterestTable");

namespace Sync
{

SyncInterestTable::SyncInterestTable(boost::asio::io_service& io, ndn::time::system_clock::Duration lifetime)
  : m_entryLifetime(lifetime)
  , m_scheduler(io)
{
  m_scheduler.scheduleEvent(ndn::time::seconds(4),
                            ndn::bind(&SyncInterestTable::expireInterests, this));
}

SyncInterestTable::~SyncInterestTable()
{
}

Interest
SyncInterestTable::pop()
{
  if (m_table.size() == 0)
    BOOST_THROW_EXCEPTION(Error::InterestTableIsEmpty());

  Interest ret = *m_table.begin();
  m_table.erase(m_table.begin());

  return ret;
}

bool
SyncInterestTable::insert(DigestConstPtr digest, const string &name, bool unknownState/*=false*/)
{
  bool existent = false;

  InterestContainer::index<named>::type::iterator it = m_table.get<named>().find(name);
  if (it != m_table.end())
    {
      existent = true;
      m_table.erase(it);
    }
  m_table.insert(Interest(digest, name, unknownState));

  return existent;
}

uint32_t
SyncInterestTable::size() const
{
  return m_table.size();
}

bool
SyncInterestTable::remove(const string &name)
{
  InterestContainer::index<named>::type::iterator item = m_table.get<named>().find(name);
  if (item != m_table.get<named>().end())
    {
      m_table.get<named>().erase(name);
      return true;
    }

  return false;
}

bool
SyncInterestTable::remove(DigestConstPtr digest)
{
  InterestContainer::index<hashed>::type::iterator item = m_table.get<hashed>().find(digest);
  if (item != m_table.get<hashed>().end())
    {
      m_table.get<hashed>().erase(digest); // erase all records associated with the digest
      return true;
    }
  return false;
}

void SyncInterestTable::expireInterests()
{
  uint32_t count = 0;
  ndn::time::system_clock::TimePoint expireTime = ndn::time::system_clock::now() - m_entryLifetime;

  while (m_table.size() > 0)
    {
      InterestContainer::index<timed>::type::iterator item = m_table.get<timed>().begin();

      if (item->m_time <= expireTime)
        {
          m_table.get<timed>().erase(item);
          count ++;
        }
      else
        break;
  }

  m_scheduler.scheduleEvent(ndn::time::seconds(4),
                            ndn::bind(&SyncInterestTable::expireInterests, this));
}


}