EpidemicRoutingExtension.cpp

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/*
 * EpidemicRoutingExtension.cpp
 *
 * Copyright (C) 2011 IBR, TU Braunschweig
 *
 * Written-by: Johannes Morgenroth <morgenroth@ibr.cs.tu-bs.de>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include "routing/epidemic/EpidemicRoutingExtension.h"

#include "routing/QueueBundleEvent.h"
#include "routing/NodeHandshakeEvent.h"
#include "net/TransferCompletedEvent.h"
#include "net/TransferAbortedEvent.h"
#include "core/NodeEvent.h"
#include "core/Node.h"
#include "net/ConnectionEvent.h"
#include "net/ConnectionManager.h"
#include "Configuration.h"
#include "core/BundleCore.h"
#include "core/EventDispatcher.h"
#include "core/BundleEvent.h"

#include <ibrdtn/data/MetaBundle.h>
#include <ibrcommon/thread/MutexLock.h>
#include <ibrcommon/Logger.h>

#include <functional>
#include <list>
#include <algorithm>

#include <iomanip>
#include <ios>
#include <iostream>
#include <set>
#include <memory>

#include <stdlib.h>
#include <typeinfo>

namespace dtn
{
        namespace routing
        {
                const std::string EpidemicRoutingExtension::TAG = "EpidemicRoutingExtension";

                EpidemicRoutingExtension::EpidemicRoutingExtension()
                {
                        // write something to the syslog
                        IBRCOMMON_LOGGER_TAG(EpidemicRoutingExtension::TAG, info) << "Initializing epidemic routing module" << IBRCOMMON_LOGGER_ENDL;
                }

                EpidemicRoutingExtension::~EpidemicRoutingExtension()
                {
                        join();
                }

                void EpidemicRoutingExtension::requestHandshake(const dtn::data::EID&, NodeHandshake &request) const
                {
                        request.addRequest(BloomFilterSummaryVector::identifier);
                }

                void EpidemicRoutingExtension::eventDataChanged(const dtn::data::EID &peer) throw ()
                {
                        // transfer the next bundle to this destination
                        _taskqueue.push( new SearchNextBundleTask( peer ) );
                }

                void EpidemicRoutingExtension::eventBundleQueued(const dtn::data::EID &peer, const dtn::data::MetaBundle &meta) throw ()
                {
                        // new bundles trigger a recheck for all neighbors
                        const std::set<dtn::core::Node> nl = dtn::core::BundleCore::getInstance().getConnectionManager().getNeighbors();

                        for (std::set<dtn::core::Node>::const_iterator iter = nl.begin(); iter != nl.end(); ++iter)
                        {
                                const dtn::core::Node &n = (*iter);

                                if (n.getEID() != peer)
                                {
                                        // trigger all routing modules to search for bundles to forward
                                        eventDataChanged(n.getEID());
                                }
                        }
                }

                void EpidemicRoutingExtension::raiseEvent(const dtn::core::Event *evt) throw ()
                {
                        try {
                                const NodeHandshakeEvent &handshake = dynamic_cast<const NodeHandshakeEvent&>(*evt);

                                if (handshake.state == NodeHandshakeEvent::HANDSHAKE_UPDATED)
                                {
                                        // transfer the next bundle to this destination
                                        _taskqueue.push( new SearchNextBundleTask( handshake.peer ) );
                                }
                                else if (handshake.state == NodeHandshakeEvent::HANDSHAKE_COMPLETED)
                                {
                                        // transfer the next bundle to this destination
                                        _taskqueue.push( new SearchNextBundleTask( handshake.peer ) );
                                }
                                return;
                        } catch (const std::bad_cast&) { };
                }

                void EpidemicRoutingExtension::componentUp() throw ()
                {
                        dtn::core::EventDispatcher<dtn::routing::NodeHandshakeEvent>::add(this);

                        // reset the task queue
                        _taskqueue.reset();

                        // routine checked for throw() on 15.02.2013
                        try {
                                // run the thread
                                start();
                        } catch (const ibrcommon::ThreadException &ex) {
                                IBRCOMMON_LOGGER_TAG(EpidemicRoutingExtension::TAG, error) << "componentUp failed: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                        }
                }

                void EpidemicRoutingExtension::componentDown() throw ()
                {
                        dtn::core::EventDispatcher<dtn::routing::NodeHandshakeEvent>::remove(this);

                        try {
                                // stop the thread
                                stop();
                                join();
                        } catch (const ibrcommon::ThreadException &ex) {
                                IBRCOMMON_LOGGER_TAG(EpidemicRoutingExtension::TAG, error) << "componentDown failed: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                        }
                }

                void EpidemicRoutingExtension::__cancellation() throw ()
                {
                        _taskqueue.abort();
                }

                void EpidemicRoutingExtension::run() throw ()
                {
                        class BundleFilter : public dtn::storage::BundleSelector
                        {
                        public:
                                BundleFilter(const NeighborDatabase::NeighborEntry &entry, const std::set<dtn::core::Node> &neighbors)
                                 : _entry(entry), _neighbors(neighbors)
                                {};

                                virtual ~BundleFilter() {};

                                virtual dtn::data::Size limit() const throw () { return _entry.getFreeTransferSlots(); };

                                virtual bool shouldAdd(const dtn::data::MetaBundle &meta) const throw (dtn::storage::BundleSelectorException)
                                {
                                        // check Scope Control Block - do not forward bundles with hop limit == 0
                                        if (meta.hopcount == 0)
                                        {
                                                return false;
                                        }

                                        // do not forward local bundles
                                        if ((meta.destination.getNode() == dtn::core::BundleCore::local)
                                                        && meta.get(dtn::data::PrimaryBlock::DESTINATION_IS_SINGLETON)
                                                )
                                        {
                                                return false;
                                        }

                                        // check Scope Control Block - do not forward non-group bundles with hop limit <= 1
                                        if ((meta.hopcount <= 1) && (meta.get(dtn::data::PrimaryBlock::DESTINATION_IS_SINGLETON)))
                                        {
                                                return false;
                                        }

                                        // do not forward bundles addressed to this neighbor,
                                        // because this is handled by neighbor routing extension
                                        if (_entry.eid == meta.destination.getNode())
                                        {
                                                return false;
                                        }

                                        // if this is a singleton bundle ...
                                        if (meta.get(dtn::data::PrimaryBlock::DESTINATION_IS_SINGLETON))
                                        {
                                                const dtn::core::Node n(meta.destination.getNode());

                                                // do not forward the bundle if the final destination is available
                                                if (_neighbors.find(n) != _neighbors.end())
                                                {
                                                        return false;
                                                }
                                        }

                                        // do not forward bundles already known by the destination
                                        // throws BloomfilterNotAvailableException if no filter is available or it is expired
                                        try {
                                                if (_entry.has(meta, true))
                                                {
                                                        return false;
                                                }
                                        } catch (const dtn::routing::NeighborDatabase::BloomfilterNotAvailableException&) {
                                                throw dtn::storage::BundleSelectorException();
                                        }

                                        return true;
                                };

                        private:
                                const NeighborDatabase::NeighborEntry &_entry;
                                const std::set<dtn::core::Node> &_neighbors;
                        };

                        // list for bundles
                        dtn::storage::BundleResultList list;

                        // set of known neighbors
                        std::set<dtn::core::Node> neighbors;

                        while (true)
                        {
                                try {
                                        Task *t = _taskqueue.getnpop(true);
                                        std::auto_ptr<Task> killer(t);

                                        IBRCOMMON_LOGGER_DEBUG_TAG(EpidemicRoutingExtension::TAG, 50) << "processing task " << t->toString() << IBRCOMMON_LOGGER_ENDL;

                                        try {
                                                try {
                                                        SearchNextBundleTask &task = dynamic_cast<SearchNextBundleTask&>(*t);

                                                        // lock the neighbor database while searching for bundles
                                                        try {
                                                                NeighborDatabase &db = (**this).getNeighborDB();
                                                                ibrcommon::MutexLock l(db);
                                                                NeighborDatabase::NeighborEntry &entry = db.get(task.eid, true);

                                                                // check if enough transfer slots available (threshold reached)
                                                                if (!entry.isTransferThresholdReached())
                                                                        throw NeighborDatabase::NoMoreTransfersAvailable();

                                                                if (dtn::daemon::Configuration::getInstance().getNetwork().doPreferDirect()) {
                                                                        // get current neighbor list
                                                                        neighbors = dtn::core::BundleCore::getInstance().getConnectionManager().getNeighbors();
                                                                } else {
                                                                        // "prefer direct" option disabled - clear the list of neighbors
                                                                        neighbors.clear();
                                                                }

                                                                // get the bundle filter of the neighbor
                                                                const BundleFilter filter(entry, neighbors);

                                                                // some debug output
                                                                IBRCOMMON_LOGGER_DEBUG_TAG(EpidemicRoutingExtension::TAG, 40) << "search some bundles not known by " << task.eid.getString() << IBRCOMMON_LOGGER_ENDL;

                                                                // query some unknown bundle from the storage
                                                                list.clear();
                                                                (**this).getSeeker().get(filter, list);
                                                        } catch (const dtn::storage::BundleSelectorException&) {
                                                                // query a new summary vector from this neighbor
                                                                (**this).doHandshake(task.eid);
                                                        }

                                                        // send the bundles as long as we have resources
                                                        for (std::list<dtn::data::MetaBundle>::const_iterator iter = list.begin(); iter != list.end(); ++iter)
                                                        {
                                                                try {
                                                                        // transfer the bundle to the neighbor
                                                                        transferTo(task.eid, *iter);
                                                                } catch (const NeighborDatabase::AlreadyInTransitException&) { };
                                                        }
                                                } catch (const NeighborDatabase::NoMoreTransfersAvailable &ex) {
                                                        IBRCOMMON_LOGGER_DEBUG_TAG(TAG, 10) << "task " << t->toString() << " aborted: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                                                } catch (const NeighborDatabase::NeighborNotAvailableException &ex) {
                                                        IBRCOMMON_LOGGER_DEBUG_TAG(TAG, 10) << "task " << t->toString() << " aborted: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                                                } catch (const dtn::storage::NoBundleFoundException &ex) {
                                                        IBRCOMMON_LOGGER_DEBUG_TAG(TAG, 10) << "task " << t->toString() << " aborted: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                                                } catch (const std::bad_cast&) { };
                                        } catch (const ibrcommon::Exception &ex) {
                                                IBRCOMMON_LOGGER_DEBUG_TAG(EpidemicRoutingExtension::TAG, 20) << "task failed: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                                        }
                                } catch (const std::exception &ex) {
                                        IBRCOMMON_LOGGER_DEBUG_TAG(EpidemicRoutingExtension::TAG, 15) << "terminated due to " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                                        return;
                                }

                                yield();
                        }
                }

                /****************************************/

                EpidemicRoutingExtension::SearchNextBundleTask::SearchNextBundleTask(const dtn::data::EID &e)
                 : eid(e)
                { }

                EpidemicRoutingExtension::SearchNextBundleTask::~SearchNextBundleTask()
                { }

                std::string EpidemicRoutingExtension::SearchNextBundleTask::toString()
                {
                        return "SearchNextBundleTask: " + eid.getString();
                }
        }
}