NeighborDatabase.cpp

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/*
 * NeighborDatabase.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/NeighborDatabase.h"
#include "core/BundleCore.h"
#include <ibrdtn/utils/Clock.h>
#include <ibrcommon/Logger.h>
#include <limits>

namespace dtn
{
        namespace routing
        {
                NeighborDatabase::NeighborEntry::NeighborEntry()
                 : eid(), _filter(), _filter_expire(0), _filter_state(FILTER_EXPIRED, FILTER_FINAL)
                {}

                NeighborDatabase::NeighborEntry::NeighborEntry(const dtn::data::EID &e)
                 : eid(e), _filter(), _filter_expire(0), _filter_state(FILTER_EXPIRED, FILTER_FINAL)
                { }

                NeighborDatabase::NeighborEntry::~NeighborEntry()
                {
                }

                void NeighborDatabase::NeighborEntry::update(const ibrcommon::BloomFilter &bf, const dtn::data::Number &lifetime)
                {
                        ibrcommon::ThreadsafeState<FILTER_REQUEST_STATE>::Locked l = _filter_state.lock();
                        _filter = bf;

                        if (lifetime == 0)
                        {
                                _filter_expire = std::numeric_limits<dtn::data::Size>::max();
                        }
                        else
                        {
                                _filter_expire = dtn::utils::Clock::getExpireTime(lifetime);
                        }

                        l = FILTER_AVAILABLE;
                }

                void NeighborDatabase::NeighborEntry::reset()
                {
                        ibrcommon::ThreadsafeState<FILTER_REQUEST_STATE>::Locked l = _filter_state.lock();

                        l = FILTER_EXPIRED;

                        // do not expire again in the next 60 seconds
                        _filter_expire = dtn::utils::Clock::getTime() + 60;
                }

                void NeighborDatabase::NeighborEntry::add(const dtn::data::MetaBundle &bundle)
                {
                        _summary.add(bundle);
                }

                bool NeighborDatabase::NeighborEntry::has(const dtn::data::BundleID &id, const bool require_bloomfilter) const
                {
                        if (_filter_state == FILTER_AVAILABLE)
                        {
                                if (id.isIn(_filter))
                                        return true;
                        }
                        else if (require_bloomfilter)
                        {
                                throw BloomfilterNotAvailableException(eid);
                        }

                        return _summary.has(id);
                }

                bool NeighborDatabase::NeighborEntry::isFilterValid() const
                {
                        return (_filter_state == FILTER_AVAILABLE);
                }

                bool NeighborDatabase::NeighborEntry::isExpired(const dtn::data::Timestamp &timestamp) const
                {
                        // expired after 15 minutes
                        return (_last_update + 900) < timestamp;
                }

                const dtn::data::Timestamp& NeighborDatabase::NeighborEntry::getLastUpdate() const
                {
                        return _last_update;
                }

                void NeighborDatabase::NeighborEntry::touch()
                {
                        _last_update = dtn::utils::Clock::getTime();
                }

                void NeighborDatabase::NeighborEntry::expire(const dtn::data::Timestamp &timestamp)
                {
                        {
                                ibrcommon::ThreadsafeState<FILTER_REQUEST_STATE>::Locked l = _filter_state.lock();

                                if ((_filter_expire > 0) && (_filter_expire < timestamp))
                                {
                                        IBRCOMMON_LOGGER_DEBUG_TAG("NeighborDatabase", 15) << "summary vector of " << eid.getString() << " is expired" << IBRCOMMON_LOGGER_ENDL;

                                        // set the filter state to expired once
                                        l = FILTER_EXPIRED;

                                        // do not expire again in the next 60 seconds
                                        _filter_expire = timestamp + 60;
                                }
                        }

                        _summary.expire(timestamp);
                }

                void NeighborDatabase::expire(const dtn::data::Timestamp &timestamp)
                {
                        for (neighbor_map::iterator iter = _entries.begin(); iter != _entries.end(); )
                        {
                                NeighborEntry &entry = (*iter->second);

                                if (entry.isExpired(timestamp)) {
                                        delete (*iter).second;
                                        _entries.erase(iter++);
                                } else {
                                        entry.expire(timestamp);
                                        ++iter;
                                }
                        }
                }

                void NeighborDatabase::NeighborEntry::acquireTransfer(const dtn::data::BundleID &id) throw (NoMoreTransfersAvailable, AlreadyInTransitException)
                {
                        // check if enough resources available to transfer the bundle
                        if (_transit_bundles.size() >= dtn::core::BundleCore::max_bundles_in_transit) throw NoMoreTransfersAvailable();

                        // check if the bundle is already in transit
                        if (_transit_bundles.find(id) != _transit_bundles.end()) throw AlreadyInTransitException();

                        // insert the bundle into the transit list
                        _transit_bundles.insert(id);

                        IBRCOMMON_LOGGER_DEBUG_TAG("NeighborDatabase", 20) << "acquire transfer of " << id.toString() << " to " << eid.getString() << " (" << _transit_bundles.size() << " bundles in transit)" << IBRCOMMON_LOGGER_ENDL;
                }

                dtn::data::Size NeighborDatabase::NeighborEntry::getFreeTransferSlots() const
                {
                        const dtn::data::Size transit_bundles = _transit_bundles.size();

                        if (dtn::core::BundleCore::max_bundles_in_transit <= transit_bundles) return 0;
                        return dtn::core::BundleCore::max_bundles_in_transit - transit_bundles;
                }

                bool NeighborDatabase::NeighborEntry::isTransferThresholdReached() const
                {
                        return _transit_bundles.size() <= (dtn::core::BundleCore::max_bundles_in_transit / 2);
                }

                void NeighborDatabase::NeighborEntry::releaseTransfer(const dtn::data::BundleID &id)
                {
                        _transit_bundles.erase(id);

                        IBRCOMMON_LOGGER_DEBUG_TAG("NeighborDatabase", 20) << "release transfer of " << id.toString() << " to " << eid.getString() << " (" << _transit_bundles.size() << " bundles in transit)" << IBRCOMMON_LOGGER_ENDL;
                }

                void NeighborDatabase::NeighborEntry::putDataset(NeighborDataset &dset)
                {
                        pair<data_set::iterator, bool> ret = _datasets.insert( dset );

                        if (!ret.second) {
                                _datasets.erase(ret.first);
                                _datasets.insert( dset );
                        }
                }

                NeighborDatabase::NeighborDatabase()
                {
                }

                NeighborDatabase::~NeighborDatabase()
                {
                        ibrcommon::MutexLock l(*this);
                        std::set<dtn::data::EID> ret;

                        for (neighbor_map::const_iterator iter = _entries.begin(); iter != _entries.end(); ++iter)
                        {
                                delete (*iter).second;
                        }
                }

                NeighborDatabase::NeighborEntry& NeighborDatabase::create(const dtn::data::EID &eid) throw ()
                {
                        neighbor_map::iterator iter = _entries.find(eid);
                        if (iter == _entries.end())
                        {
                                NeighborEntry *entry = new NeighborEntry(eid);
                                pair<neighbor_map::iterator,bool> itm = _entries.insert( pair<dtn::data::EID, NeighborDatabase::NeighborEntry*>(eid, entry) );
                                iter = itm.first;
                        }

                        // set last update timestamp
                        (*(*iter).second).touch();

                        return *(*iter).second;
                }

                NeighborDatabase::NeighborEntry& NeighborDatabase::get(const dtn::data::EID &eid, bool noCached) throw (EntryNotFoundException)
                {
                        if (noCached && !dtn::core::BundleCore::getInstance().getConnectionManager().isNeighbor(eid))
                                throw NeighborDatabase::EntryNotFoundException();

                        neighbor_map::iterator iter = _entries.find(eid);
                        if (iter == _entries.end())
                        {
                                throw EntryNotFoundException();
                        }

                        // set last update timestamp
                        (*(*iter).second).touch();

                        return *(*iter).second;
                }

                void NeighborDatabase::remove(const dtn::data::EID &eid)
                {
                        neighbor_map::iterator iter = _entries.find(eid);
                        if (iter == _entries.end())
                        {
                                delete (*iter).second;
                                _entries.erase(iter);
                        }
                }
        }
}