fw: implement self-learning forwarding strategy
refs #4279
Change-Id: I3c80820f9e3382d204a75ea3248234581b4d97d2
diff --git a/daemon/fw/self-learning-strategy.hpp b/daemon/fw/self-learning-strategy.hpp
new file mode 100644
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+++ b/daemon/fw/self-learning-strategy.hpp
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+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2014-2019, 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_SELF_LEARNING_STRATEGY_HPP
+#define NFD_DAEMON_FW_SELF_LEARNING_STRATEGY_HPP
+
+#include "fw/strategy.hpp"
+
+#include <ndn-cxx/lp/prefix-announcement-header.hpp>
+
+namespace nfd {
+namespace fw {
+
+/** \brief Self-learning strategy
+ *
+ * This strategy first broadcasts Interest to learn a single path towards data,
+ * then unicasts subsequent Interests along the learned path
+ *
+ * \see https://redmine.named-data.net/attachments/864/Self-learning-strategy-v1.pdf
+ */
+class SelfLearningStrategy : public Strategy
+{
+public:
+ explicit
+ SelfLearningStrategy(Forwarder& forwarder, const Name& name = getStrategyName());
+
+ static const Name&
+ getStrategyName();
+
+ /// StrategyInfo on pit::InRecord
+ class InRecordInfo : public StrategyInfo
+ {
+ public:
+ static constexpr int
+ getTypeId()
+ {
+ return 1040;
+ }
+
+ public:
+ bool isNonDiscoveryInterest = false;
+ };
+
+ /// StrategyInfo on pit::OutRecord
+ class OutRecordInfo : public StrategyInfo
+ {
+ public:
+ static constexpr int
+ getTypeId()
+ {
+ return 1041;
+ }
+
+ public:
+ bool isNonDiscoveryInterest = false;
+ };
+
+public: // triggers
+ void
+ afterReceiveInterest(const Face& inFace, const Interest& interest,
+ const shared_ptr<pit::Entry>& pitEntry) override;
+
+ void
+ afterReceiveData(const shared_ptr<pit::Entry>& pitEntry,
+ const Face& inFace, const Data& data) override;
+
+ void
+ afterReceiveNack(const Face& inFace, const lp::Nack& nack,
+ const shared_ptr<pit::Entry>& pitEntry) override;
+
+private: // operations
+
+ /** \brief Send an Interest to all possible faces
+ *
+ * This function is invoked when the forwarder has no matching FIB entries for
+ * an incoming discovery Interest, which will be forwarded to faces that
+ * - do not violate the Interest scope
+ * - are non-local
+ * - are not the face from which the Interest arrived, unless the face is ad-hoc
+ */
+ void
+ broadcastInterest(const Interest& interest, const Face& inFace,
+ const shared_ptr<pit::Entry>& pitEntry);
+
+ /** \brief Send an Interest to \p nexthops
+ */
+ void
+ multicastInterest(const Interest& interest, const Face& inFace,
+ const shared_ptr<pit::Entry>& pitEntry,
+ const fib::NextHopList& nexthops);
+
+ /** \brief Find a Prefix Announcement for the Data on the RIB thread, and forward
+ * the Data with the Prefix Announcement on the main thread
+ */
+ void
+ asyncProcessData(const shared_ptr<pit::Entry>& pitEntry, const Face& inFace, const Data& data);
+
+ /** \brief Check whether a PrefixAnnouncement needs to be attached to an incoming Data
+ *
+ * The conditions that a Data packet requires a PrefixAnnouncement are
+ * - the incoming Interest was discovery and
+ * - the outgoing Interest was non-discovery and
+ * - this forwarder does not directly connect to the consumer
+ */
+ static bool
+ needPrefixAnn(const shared_ptr<pit::Entry>& pitEntry);
+
+ /** \brief Add a route using RibManager::slAnnounce on the RIB thread
+ */
+ void
+ addRoute(const shared_ptr<pit::Entry>& pitEntry, const Face& inFace,
+ const Data& data, const ndn::PrefixAnnouncement& pa);
+
+ /** \brief renew a route using RibManager::slRenew on the RIB thread
+ */
+ void
+ renewRoute(const Name& name, FaceId inFaceId, time::milliseconds maxLifetime);
+
+private:
+ static const time::milliseconds ROUTE_RENEW_LIFETIME;
+};
+
+} // namespace fw
+} // namespace nfd
+
+#endif // NFD_DAEMON_FW_SELF_LEARNING_STRATEGY_HPP