RetransmissionExtension.cpp

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/*
 * RetransmissionExtension.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/RetransmissionExtension.h"
#include "routing/RequeueBundleEvent.h"
#include "core/TimeEvent.h"
#include "core/BundleCore.h"
#include "core/EventDispatcher.h"
#include "core/BundleExpiredEvent.h"
#include "net/TransferAbortedEvent.h"
#include "net/TransferCompletedEvent.h"

#include <ibrdtn/utils/Clock.h>
#include <ibrdtn/data/Exceptions.h>
#include <ibrcommon/thread/MutexLock.h>


namespace dtn
{
        namespace routing
        {
                RetransmissionExtension::RetransmissionExtension()
                {
                }

                RetransmissionExtension::~RetransmissionExtension()
                {
                }

                void RetransmissionExtension::componentUp() throw ()
                {
                        dtn::core::EventDispatcher<dtn::core::TimeEvent>::add(this);
                        dtn::core::EventDispatcher<dtn::net::TransferAbortedEvent>::add(this);
                        dtn::core::EventDispatcher<dtn::routing::RequeueBundleEvent>::add(this);
                        dtn::core::EventDispatcher<dtn::core::BundleExpiredEvent>::add(this);
                }

                void RetransmissionExtension::componentDown() throw ()
                {
                        dtn::core::EventDispatcher<dtn::core::TimeEvent>::remove(this);
                        dtn::core::EventDispatcher<dtn::net::TransferAbortedEvent>::remove(this);
                        dtn::core::EventDispatcher<dtn::routing::RequeueBundleEvent>::remove(this);
                        dtn::core::EventDispatcher<dtn::core::BundleExpiredEvent>::remove(this);
                }

                void RetransmissionExtension::eventTransferCompleted(const dtn::data::EID &peer, const dtn::data::MetaBundle &meta) throw ()
                {
                        // remove the bundleid in our list
                        RetransmissionData data(meta, peer);
                        _set.erase(data);
                }

                void RetransmissionExtension::raiseEvent(const dtn::core::Event *evt) throw ()
                {
                        try {
                                const dtn::core::TimeEvent &time = dynamic_cast<const dtn::core::TimeEvent&>(*evt);

                                ibrcommon::MutexLock l(_mutex);
                                if (!_queue.empty())
                                {
                                        const RetransmissionData &data = _queue.front();

                                        if ( data.getTimestamp() <= time.getTimestamp() )
                                        {
                                                try {
                                                        const dtn::data::MetaBundle meta = dtn::core::BundleCore::getInstance().getStorage().info(data);

                                                        try {
                                                                // create a new bundle transfer
                                                                dtn::net::BundleTransfer transfer(data.destination, meta);

                                                                // re-queue the bundle
                                                                dtn::core::BundleCore::getInstance().getConnectionManager().queue(transfer);
                                                        } catch (const ibrcommon::Exception&) {
                                                                // do nothing here
                                                        }
                                                } catch (const ibrcommon::Exception&) {
                                                        // bundle is not available, abort transmission
                                                        dtn::net::TransferAbortedEvent::raise(data.destination, data, dtn::net::TransferAbortedEvent::REASON_BUNDLE_DELETED);
                                                }

                                                // remove the item off the queue
                                                _queue.pop();
                                        }
                                }
                                return;
                        } catch (const std::bad_cast&) { };

                        try {
                                const dtn::net::TransferAbortedEvent &aborted = dynamic_cast<const dtn::net::TransferAbortedEvent&>(*evt);

                                // remove the bundleid in our list
                                RetransmissionData data(aborted.getBundleID(), aborted.getPeer());
                                _set.erase(data);

                                return;
                        } catch (const std::bad_cast&) { };

                        try {
                                const dtn::routing::RequeueBundleEvent &requeue = dynamic_cast<const dtn::routing::RequeueBundleEvent&>(*evt);

                                const RetransmissionData data(requeue.getBundle(), requeue.getPeer());

                                ibrcommon::MutexLock l(_mutex);
                                std::set<RetransmissionData>::const_iterator iter = _set.find(data);

                                if (iter != _set.end())
                                {
                                        // increment the retry counter
                                        RetransmissionData data2 = (*iter);
                                        data2++;

                                        // remove the item
                                        _set.erase(data);

                                        if (data2.getCount() <= 8)
                                        {
                                                // requeue the bundle
                                                _set.insert(data2);
                                                _queue.push(data2);
                                        }
                                        else
                                        {
                                                dtn::net::TransferAbortedEvent::raise(requeue.getPeer(), requeue.getBundle(), dtn::net::TransferAbortedEvent::REASON_RETRY_LIMIT_REACHED);
                                        }
                                }
                                else
                                {
                                        // queue the bundle
                                        _set.insert(data);
                                        _queue.push(data);
                                }

                                return;
                        } catch (const std::bad_cast&) { };

                        try {
                                const dtn::core::BundleExpiredEvent &expired = dynamic_cast<const dtn::core::BundleExpiredEvent&>(*evt);

                                // delete all matching elements in the queue
                                ibrcommon::MutexLock l(_mutex);

                                dtn::data::Size elements = _queue.size();
                                for (dtn::data::Size i = 0; i < elements; ++i)
                                {
                                        const RetransmissionData &data = _queue.front();

                                        if ((dtn::data::BundleID&)data == expired.getBundle())
                                        {
                                                dtn::net::TransferAbortedEvent::raise(data.destination, data, dtn::net::TransferAbortedEvent::REASON_BUNDLE_DELETED);
                                        }
                                        else
                                        {
                                                _queue.push(data);
                                        }

                                        _queue.pop();
                                }

                                return;
                        } catch (const std::bad_cast&) { };
                }

                bool RetransmissionExtension::RetransmissionData::operator!=(const RetransmissionData &obj)
                {
                        const dtn::data::BundleID &id1 = dynamic_cast<const dtn::data::BundleID&>(obj);
                        const dtn::data::BundleID &id2 = dynamic_cast<const dtn::data::BundleID&>(*this);

                        if (id1 != id2) return true;
                        if (obj.destination != destination) return true;

                        return false;
                }

                bool RetransmissionExtension::RetransmissionData::operator==(const RetransmissionData &obj)
                {
                        const dtn::data::BundleID &id1 = dynamic_cast<const dtn::data::BundleID&>(obj);
                        const dtn::data::BundleID &id2 = dynamic_cast<const dtn::data::BundleID&>(*this);

                        if (id1 != id2) return false;
                        if (obj.destination != destination) return false;

                        return true;
                }

                dtn::data::Size RetransmissionExtension::RetransmissionData::getCount() const
                {
                        return _count;
                }

                const dtn::data::Timestamp& RetransmissionExtension::RetransmissionData::getTimestamp() const
                {
                        return _timestamp;
                }

                RetransmissionExtension::RetransmissionData& RetransmissionExtension::RetransmissionData::operator++(int)
                {
                        _count++;
                        _timestamp = dtn::utils::Clock::getTime();
                        float backoff = ::pow((float)retry, (int)_count -1);
                        _timestamp += static_cast<dtn::data::Size>(backoff);

                        return (*this);
                }

                RetransmissionExtension::RetransmissionData& RetransmissionExtension::RetransmissionData::operator++()
                {
                        _count++;
                        _timestamp = dtn::utils::Clock::getTime();
                        float backoff = ::pow((float)retry, (int)_count -1);
                        _timestamp += static_cast<dtn::data::Size>(backoff);

                        return (*this);
                }

                RetransmissionExtension::RetransmissionData::RetransmissionData(const dtn::data::BundleID &id, const dtn::data::EID &d, const dtn::data::Size r)
                 : dtn::data::BundleID(id), destination(d), _timestamp(0), _count(0), retry(r)
                {
                        (*this)++;
                }

                RetransmissionExtension::RetransmissionData::~RetransmissionData()
                {
                }
        }
}