/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2011-2013 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: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
 */

#ifndef AGGREGATE_STATS_POLICY_H_
#define AGGREGATE_STATS_POLICY_H_

#include <boost/intrusive/options.hpp>
#include <boost/intrusive/list.hpp>

namespace ns3 {
namespace ndn {
namespace ndnSIM {

/**
 * @brief Traits for policy that just keeps track of number of elements
 * It's doing a rather expensive job, but just in case it needs to be extended later
 */
struct aggregate_stats_policy_traits
{
  /// @brief Name that can be used to identify the policy (for NS-3 object model and logging)
  static std::string GetName () { return "AggregateStats"; }
  struct policy_hook_type { };

  template<class Container>
  struct container_hook
  {
    struct type { };
  };

  template<class Base,
           class Container,
           class Hook>
  struct policy
  {
    // typedef typename boost::intrusive::list< Container, Hook > policy_container;

    // could be just typedef
    class type
    {
    public:
      typedef Container parent_trie;

      type (Base &base)
        : base_ (base)
        , m_updates (0)
        , m_inserts (0)
        , m_lookups (0)
        , m_erases (0)
      {
      }

      inline void
      update (typename parent_trie::iterator item)
      {
        m_updates ++;
        // do nothing
      }

      inline bool
      insert (typename parent_trie::iterator item)
      {
        m_inserts ++;
        return true;
      }

      inline void
      lookup (typename parent_trie::iterator item)
      {
        m_lookups ++;
      }

      inline void
      erase (typename parent_trie::iterator item)
      {
        m_erases ++;
      }

      inline void
      set_max_size (uint32_t) {}

      inline uint32_t
      get_max_size () const { return 0; }

      inline void
      clear ()
      {
        // is called only at the end of simulation
      }

      inline void
      ResetStats ()
      {
        m_updates = 0;
        m_inserts = 0;
        m_lookups = 0;
        m_erases = 0;
      }

      inline uint64_t
      GetUpdates () const { return m_updates; }

      inline uint64_t
      GetInserts () const { return m_inserts; }

      inline uint64_t
      GetLookups () const { return m_lookups; }

      inline uint64_t
      GetErases () const { return m_erases; }

    private:
      type () : base_(*((Base*)0)) { };

    private:
      Base &base_;
      
      uint64_t m_updates;
      uint64_t m_inserts;
      uint64_t m_lookups;
      uint64_t m_erases;
    };
  };
};

} // ndnSIM
} // ndn
} // ns3

#endif // AGGREGATE_STATS_POLICY_H_