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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
/*
* Copyright (c) 2011 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 _CCNX_RIT_H_
#define _CCNX_RIT_H_
#include <list>
#include "ns3/nstime.h"
#include "ns3/ccnx-name-components.h"
#include "ns3/object.h"
#include "ns3/nstime.h"
#include "ns3/event-id.h"
#include <boost/multi_index_container.hpp>
#include <boost/multi_index/tag.hpp>
#include <boost/multi_index/ordered_index.hpp>
#include <boost/multi_index/sequenced_index.hpp>
#include <boost/multi_index/hashed_index.hpp>
#include <boost/multi_index/member.hpp>
namespace ns3 {
class CcnxInterestHeader;
/**
* \ingroup ccnx
* \brief Recently satisfied interest
*
* This entry holds information about recently satisfied interest
*
* RIT entries will stay in the table for a while before being cleaned out
*/
struct CcnxRitEntry
{
CcnxNameComponents m_prefix; ///< \brief Prefix of the recently satisfied interest
uint32_t m_nonce; ///< \brief Nonce of the recently satisfied interest
Time m_expireTime; ///< \brief Time when the record should be removed
CcnxRitEntry (const CcnxNameComponents &prefix, uint32_t nonce, const Time &timeout)
: m_prefix (prefix)
, m_nonce (nonce)
, m_expireTime (timeout)
{ }
};
/**
* \ingroup ccnx
* \brief Private namespace for CCNx RIT implementation
*/
namespace __ccnx_private_rit
{
class nonce {}; ///< tag for nonce hash
class timestamp {}; ///< tag for timestamp-ordered records (for cleanup optimization)
};
/**
* \ingroup ccnx
* \brief Typedef for RIT container implemented as a Boost.MultiIndex container
*
* - First index (tag<nonce>) is a non-unique hash index based on
* nonce (there could be several records with the same nonce,
* provided that the prefixes are different
* - Second index (tag<timestamp>) is a sequenced index based on
* arrival order (for clean-up optimizations)
*
* Container allows having non-unique nonce values. In the
* implementation it is allowed only if prefixes are different. During
* the lookup process, the nonce field is checked first and, if a
* match found, the prefix field will be checked to match prefix of
* the interest.
*
* \see http://www.boost.org/doc/libs/1_46_1/libs/multi_index/doc/ for more information on Boost.MultiIndex library
*/
struct CcnxRitContainer
{
typedef
boost::multi_index::multi_index_container<
CcnxRitEntry,
boost::multi_index::indexed_by<
boost::multi_index::hashed_non_unique<
boost::multi_index::tag<__ccnx_private_rit::nonce>,
boost::multi_index::member<CcnxRitEntry, uint32_t, &CcnxRitEntry::m_nonce>
>,
boost::multi_index::sequenced<
boost::multi_index::tag<__ccnx_private_rit::timestamp> >
>
> type;
};
/**
* \ingroup ccnx
* \brief Recently satisfied interest storage
*
* This storage holds information about all recently satisfied
* interests (prefix and nonce).
*
* There is no hard limit on number of entries (limited by the amount
* of the available memory). Entries are removed after preconfigured
* amount of time (RitTimeout, default is 1 second).
*/
class CcnxRit : public CcnxRitContainer::type, public Object
{
public:
/**
* \brief Interface ID
*
* \return interface ID
*/
static TypeId GetTypeId ();
/**
* \brief Default constructor
*/
CcnxRit ();
virtual ~CcnxRit( );
/**
* \brief Find corresponding RIT entry for the given content name
*
* This check consists of two steps. First, we find records with
* the same nonce. Then check prefixes of all found records and if
* prefix of any of them matched prefix of the interest, this
* function returns true. In all other cases, it will return false.
*
* \param header header of the interest packet in question
*
* \returns true if the same interest was recently satisfied
*/
bool WasRecentlySatisfied (const CcnxInterestHeader &header);
/**
* \brief Add a new RIT entry
*
* This function asserts (only in debug) if the same interest is
* already present in RIT. The caller is responsible of calling
* WasRecentlySatisfied before calling SetRecentlySatisfied.
*
* \param header header of the interest packet in question
*/
void SetRecentlySatisfied (const CcnxInterestHeader &header);
/**
* \brief Set RIT entries lifetime
*
* \param lifetime of RIT entries timeout
*/
void SetRitTimeout (const Time &timeout);
/**
* \brief Get RIT entries lifetime
*
* \returns lifetime of RIT entries timeout
*/
Time GetRitTimeout () const;
/**
* \brief Set cleanup timeout
*
* Side effect: current clean up even (if any) will be cancelled and a new event started
*
* \param timeout cleanup timeout
*/
void SetCleanupTimeout (const Time &timeout);
/**
* \brief Get cleanup timeout
*
* \returns cleanup timeout
*/
Time GetCleanupTimeout () const;
private:
/**
* \brief Periodic even to clean up stalled entries
*/
void CleanExpired ();
private:
Time m_ritTimeout; ///< \brief Configurable timeout of RIT entries
Time m_cleanupTimeout; ///< \brief Configurable timeout of how often cleanup events are working
EventId m_cleanupEvent; ///< \brief Cleanup event
};
} // namespace ns3
#endif // _CCNX_RIT_H_