DTNTPWorker.h

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/*
 * DTNTPWorker.h
 *
 * 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.
 *
 */

#ifndef DTNTPWORKER_H_
#define DTNTPWORKER_H_

#include "core/AbstractWorker.h"
#include "core/EventReceiver.h"
#include "net/DiscoveryServiceProvider.h"
#include "Configuration.h"

namespace dtn
{
        namespace daemon
        {
                class DTNTPWorker : public dtn::core::AbstractWorker, public dtn::core::EventReceiver, public dtn::net::DiscoveryServiceProvider
                {
                public:
                        DTNTPWorker();

                        virtual ~DTNTPWorker();

                        void callbackBundleReceived(const Bundle &b);

                        void raiseEvent(const dtn::core::Event *evt) throw ();

                        void update(const ibrcommon::vinterface &iface, DiscoveryAnnouncement &announcement)
                                throw(NoServiceHereException);

//                      /**
//                       * Determine the current local clock rating
//                       * @return The rating as double value.
//                       */
//                      double getClockRating() const;

                        class TimeSyncMessage
                        {
                        public:
                                enum MSG_TYPE
                                {
                                        TIMESYNC_REQUEST = 1,
                                        TIMESYNC_RESPONSE = 2
                                };

                                TimeSyncMessage();
                                ~TimeSyncMessage();

                                MSG_TYPE type;

                                timeval origin_timestamp;
                                double origin_rating;

                                timeval peer_timestamp;
                                double peer_rating;

                                friend std::ostream &operator<<(std::ostream &stream, const DTNTPWorker::TimeSyncMessage &obj);
                                friend std::istream &operator>>(std::istream &stream, DTNTPWorker::TimeSyncMessage &obj);
                        };

                private:
                        static const unsigned int PROTO_VERSION;
                        static const std::string TAG;

                        bool shouldSyncWith(const dtn::core::Node &node) const;

                        void syncWith(const dtn::core::Node &node);

                        bool hasReference() const;

                        void decode(const dtn::core::Node::Attribute &attr, unsigned int &version, dtn::data::Timestamp &timestamp, float &quality) const;

                        void sync(const TimeSyncMessage &msg, const struct timeval &tv, const struct timeval &local, const struct timeval &remote);

                        // sync threshold
                        float _sync_threshold;

                        // send discovery announcements with the local clock rating
                        bool _announce_rating;

                        // the base rating used to determine the current clock rating
                        double _base_rating;

                        // the local rating is at least decremented by this value between each synchronization
                        double _psi;

                        // current value for sigma
                        double _sigma;

                        // synchronize with other nodes
                        bool _sync;

                        // timestamp of the last synchronization with another (better) clock
                        timeval _last_sync_time;

                        // Mutex to lock the synchronization process
                        ibrcommon::Mutex _sync_lock;

                        // manage a list of recently sync'd nodes
                        ibrcommon::Mutex _blacklist_lock;
                        typedef std::map<EID, dtn::data::Timestamp> blacklist_map;
                        blacklist_map _sync_blacklist;
                };
        }
}

#endif /* DTNTPWORKER_H_ */