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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
* Copyright (c) 2014, 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/>.
*/
#ifndef NFD_DAEMON_FW_STRATEGY_HPP
#define NFD_DAEMON_FW_STRATEGY_HPP
#include "forwarder.hpp"
#include "table/measurements-accessor.hpp"
namespace nfd {
namespace fw {
/** \brief represents a forwarding strategy
*/
class Strategy : public enable_shared_from_this<Strategy>, noncopyable
{
public:
Strategy(Forwarder& forwarder, const Name& name);
virtual
~Strategy();
/// a Name that represent the Strategy program
const Name&
getName() const;
public: // triggers
/** \brief trigger after Interest is received
*
* The Interest:
* - does not violate Scope
* - is not looped
* - cannot be satisfied by ContentStore
* - is under a namespace managed by this strategy
*
* The strategy should decide whether and where to forward this Interest.
* - If the strategy decides to forward this Interest,
* invoke this->sendInterest one or more times, either now or shortly after
* - If strategy concludes that this Interest cannot be forwarded,
* invoke this->rejectPendingInterest so that PIT entry will be deleted shortly
*
* \note The strategy is permitted to store a weak reference to fibEntry.
* Do not store a shared reference, because PIT entry may be deleted at any moment.
* fibEntry is passed by value to allow obtaining a weak reference from it.
* \note The strategy is permitted to store a shared reference to pitEntry.
* pitEntry is passed by value to reflect this fact.
*/
virtual void
afterReceiveInterest(const Face& inFace,
const Interest& interest,
shared_ptr<fib::Entry> fibEntry,
shared_ptr<pit::Entry> pitEntry) = 0;
/** \brief trigger before PIT entry is satisfied
*
* This trigger is invoked when an incoming Data satisfies the PIT entry.
* It can be invoked even if the PIT entry has already been satisfied.
*
* In this base class this method does nothing.
*
* \note The strategy is permitted to store a shared reference to pitEntry.
* pitEntry is passed by value to reflect this fact.
*/
virtual void
beforeSatisfyInterest(shared_ptr<pit::Entry> pitEntry,
const Face& inFace, const Data& data);
/** \brief trigger before PIT entry expires
*
* PIT entry expires when InterestLifetime has elapsed for all InRecords,
* and it is not satisfied by an incoming Data.
*
* This trigger is not invoked for PIT entry already satisfied.
*
* In this base class this method does nothing.
*
* \note The strategy is permitted to store a shared reference to pitEntry.
* pitEntry is passed by value to reflect this fact.
*/
virtual void
beforeExpirePendingInterest(shared_ptr<pit::Entry> pitEntry);
protected: // actions
/// send Interest to outFace
VIRTUAL_WITH_TESTS void
sendInterest(shared_ptr<pit::Entry> pitEntry,
shared_ptr<Face> outFace,
bool wantNewNonce = false);
/** \brief decide that a pending Interest cannot be forwarded
*
* This shall not be called if the pending Interest has been
* forwarded earlier, and does not need to be resent now.
*/
VIRTUAL_WITH_TESTS void
rejectPendingInterest(shared_ptr<pit::Entry> pitEntry);
protected: // accessors
MeasurementsAccessor&
getMeasurements();
shared_ptr<Face>
getFace(FaceId id);
private:
Name m_name;
/** \brief reference to the forwarder
*
* Triggers can access forwarder indirectly via actions.
*/
Forwarder& m_forwarder;
MeasurementsAccessor m_measurements;
};
inline const Name&
Strategy::getName() const
{
return m_name;
}
inline void
Strategy::sendInterest(shared_ptr<pit::Entry> pitEntry,
shared_ptr<Face> outFace,
bool wantNewNonce)
{
m_forwarder.onOutgoingInterest(pitEntry, *outFace, wantNewNonce);
}
inline void
Strategy::rejectPendingInterest(shared_ptr<pit::Entry> pitEntry)
{
m_forwarder.onInterestReject(pitEntry);
}
inline MeasurementsAccessor&
Strategy::getMeasurements()
{
return m_measurements;
}
inline shared_ptr<Face>
Strategy::getFace(FaceId id)
{
return m_forwarder.getFace(id);
}
} // namespace fw
} // namespace nfd
#endif // NFD_DAEMON_FW_STRATEGY_HPP