Registration.cpp

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/*
 * Registration.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 "config.h"
#include "Configuration.h"
#include "api/Registration.h"
#include "storage/BundleStorage.h"
#include "core/BundleCore.h"
#include "core/BundleEvent.h"
#include "core/BundlePurgeEvent.h"
#include "core/FragmentManager.h"
#include "net/BundleReceivedEvent.h"

#ifdef HAVE_SQLITE
#include "storage/SQLiteBundleStorage.h"
#endif

#include <ibrdtn/data/TrackingBlock.h>
#include <ibrdtn/data/AgeBlock.h>

#include <ibrdtn/utils/Clock.h>
#include <ibrdtn/utils/Random.h>
#include <ibrcommon/Logger.h>

#include <limits.h>
#include <stdint.h>

namespace dtn
{
        namespace api
        {
                const std::string Registration::TAG = "Registration";
                ibrcommon::Mutex Registration::_handle_lock;
                std::set<std::string> Registration::_handles;

                const std::string Registration::gen_handle()
                {
                        std::string new_handle = dtn::utils::Random::gen_chars(16);

                        // if the local host is configured with an IPN address
                        if (dtn::core::BundleCore::local.isCompressable())
                        {
                                // .. then use 32-bit numbers only
                                uint32_t *int_handle = (uint32_t*)new_handle.c_str();
                                std::stringstream ss;
                                ss << *int_handle;
                                new_handle = ss.str();
                        }

                        return new_handle;
                }

                const std::string& Registration::alloc_handle(const std::string &handle)
                {
                        ibrcommon::MutexLock l(_handle_lock);
                        std::pair<std::set<std::string>::iterator, bool> ret = _handles.insert(handle);

                        while (!ret.second) {
                                ret = _handles.insert(gen_handle());
                        }

                        return (*ret.first);
                }

                const std::string& Registration::alloc_handle()
                {
                        return alloc_handle(gen_handle());
                }

                void Registration::free_handle(const std::string &handle)
                {
                        ibrcommon::MutexLock l(_handle_lock);
                        _handles.erase(handle);
                }

                Registration::Registration(const std::string &handle)
                 : _handle(alloc_handle(handle)),
                   _default_eid(core::BundleCore::local), _no_more_bundles(false),
                   _persistent(false), _detached(false), _expiry(0), _filter_fragments(true)
                {
                        _default_eid.setApplication(_handle);
                }

                Registration::Registration()
                 : _handle(alloc_handle()),
                   _default_eid(core::BundleCore::local), _no_more_bundles(false),
                   _persistent(false), _detached(false), _expiry(0), _filter_fragments(true)
                {
                        _default_eid.setApplication(_handle);
                }

                Registration::~Registration()
                {
                        free_handle(_handle);
                }

                void Registration::notify(const NOTIFY_CALL call)
                {
                        ibrcommon::MutexLock l(_wait_for_cond);
                        if (call == NOTIFY_BUNDLE_AVAILABLE)
                        {
                                _no_more_bundles = false;
                                _wait_for_cond.signal(true);
                        }
                        else
                        {
                                _notify_queue.push(call);
                        }
                }

                void Registration::wait_for_bundle(size_t timeout)
                {
                        ibrcommon::MutexLock l(_wait_for_cond);

                        while (_no_more_bundles)
                        {
                                if (timeout > 0)
                                {
                                        _wait_for_cond.wait(timeout);
                                }
                                else
                                {
                                        _wait_for_cond.wait();
                                }
                        }
                }

                Registration::NOTIFY_CALL Registration::wait()
                {
                        return _notify_queue.poll();
                }

                bool Registration::hasSubscribed(const dtn::data::EID &endpoint)
                {
                        ibrcommon::MutexLock l(_endpoints_lock);
                        return (_endpoints.find(endpoint) != _endpoints.end());
                }

                const std::set<dtn::data::EID> Registration::getSubscriptions()
                {
                        ibrcommon::MutexLock l(_endpoints_lock);
                        return _endpoints;
                }

                void Registration::delivered(const dtn::data::MetaBundle &m) const
                {
                        // raise bundle event
                        dtn::core::BundleEvent::raise(m, dtn::core::BUNDLE_DELIVERED);

                        if (m.get(dtn::data::PrimaryBlock::DESTINATION_IS_SINGLETON))
                        {
                                dtn::core::BundlePurgeEvent::raise(m);
                        }
                }

                dtn::data::Bundle Registration::receive() throw (dtn::storage::NoBundleFoundException)
                {
                        // get the global storage
                        dtn::storage::BundleStorage &storage = dtn::core::BundleCore::getInstance().getStorage();

                        // get the next bundles as MetaBundle
                        dtn::data::MetaBundle b = receiveMetaBundle();

                        // load the bundle
                        return storage.get(b);
                }

                dtn::data::MetaBundle Registration::receiveMetaBundle() throw (dtn::storage::NoBundleFoundException)
                {
                        ibrcommon::MutexLock l(_receive_lock);

                        while(true)
                        {
                                try {
                                        // get the first bundle in the queue
                                        dtn::data::MetaBundle b = _queue.pop();
                                        return b;
                                } catch (const ibrcommon::QueueUnblockedException &e) {
                                        if (e.reason == ibrcommon::QueueUnblockedException::QUEUE_ABORT)
                                        {
                                                IBRCOMMON_LOGGER_DEBUG_TAG(Registration::TAG, 25) << "search for more bundles" << IBRCOMMON_LOGGER_ENDL;

                                                // query for new bundles
                                                underflow();
                                        }
                                }
                                catch(const dtn::storage::NoBundleFoundException & ){
                                }
                        }

                        throw dtn::storage::NoBundleFoundException();
                }

                void Registration::underflow()
                {
                        bool fragment_conf = dtn::daemon::Configuration::getInstance().getNetwork().doFragmentation();

                        // expire outdated bundles in the list
                        _queue.expire(dtn::utils::Clock::getTime());

#ifdef HAVE_SQLITE
                        class BundleFilter : public dtn::storage::BundleSelector, public dtn::storage::SQLiteDatabase::SQLBundleQuery
#else
                        class BundleFilter : public dtn::storage::BundleSelector
#endif
                        {
                        public:
                                BundleFilter(const std::set<dtn::data::EID> endpoints, const RegistrationQueue &queue, bool loopback, bool fragment_filter)
                                 : _endpoints(endpoints), _queue(queue), _loopback(loopback), _fragment_filter(fragment_filter)
                                {};

                                virtual ~BundleFilter() {};

                                virtual dtn::data::Size limit() const throw () { return dtn::core::BundleCore::max_bundles_in_transit; };

                                virtual bool shouldAdd(const dtn::data::MetaBundle &meta) const throw (dtn::storage::BundleSelectorException)
                                {
                                        // filter fragments if requested
                                        if (meta.isFragment() && _fragment_filter)
                                        {
                                                return false;
                                        }

                                        if (_endpoints.find(meta.destination) == _endpoints.end())
                                        {
                                                return false;
                                        }

                                        // filter own bundles
                                        if (!_loopback)
                                        {
                                                if (_endpoints.find(meta.source) != _endpoints.end())
                                                {
                                                        return false;
                                                }
                                        }

                                        IBRCOMMON_LOGGER_DEBUG_TAG(Registration::TAG, 30) << "search bundle in the list of delivered bundles: " << meta.toString() << IBRCOMMON_LOGGER_ENDL;

                                        if (_queue.has(meta))
                                        {
                                                return false;
                                        }

                                        return true;
                                };

#ifdef HAVE_SQLITE
                                const std::string getWhere() const throw ()
                                {
                                        if (_endpoints.size() > 1)
                                        {
                                                std::string where = "(";

                                                for (size_t i = _endpoints.size() - 1; i > 0; i--)
                                                {
                                                        where += "destination = ? OR ";
                                                }

                                                return where + "destination = ?)";
                                        }
                                        else if (_endpoints.size() == 1)
                                        {
                                                return "destination = ?";
                                        }
                                        else
                                        {
                                                return "destination = null";
                                        }
                                };

                                int bind(sqlite3_stmt *st, int offset) const throw ()
                                {
                                        int o = offset;

                                        for (std::set<dtn::data::EID>::const_iterator iter = _endpoints.begin(); iter != _endpoints.end(); ++iter)
                                        {
                                                const std::string data = (*iter).getString();

                                                sqlite3_bind_text(st, o, data.c_str(), static_cast<int>(data.size()), SQLITE_TRANSIENT);
                                                o++;
                                        }

                                        return o;
                                }
#endif

                        private:
                                const std::set<dtn::data::EID> _endpoints;
                                const RegistrationQueue &_queue;
                                const bool _loopback;
                                const bool _fragment_filter;
                        } filter(_endpoints, _queue, false, fragment_conf && _filter_fragments);

                        // query the database for more bundles
                        ibrcommon::MutexLock l(_endpoints_lock);

                        try {
                                dtn::core::BundleCore::getInstance().getSeeker().get( filter, _queue );
                        } catch (const dtn::storage::NoBundleFoundException&) {
                                _no_more_bundles = true;
                                throw;
                        }
                }

                Registration::RegistrationQueue::RegistrationQueue()
                {
                }

                Registration::RegistrationQueue::~RegistrationQueue()
                {
                }

                void Registration::RegistrationQueue::put(const dtn::data::MetaBundle &bundle) throw ()
                {
                        try {
                                _queue.push(bundle);

                                ibrcommon::MutexLock l(_lock);
                                _recv_bundles.add(bundle);

                                IBRCOMMON_LOGGER_DEBUG_TAG(Registration::TAG, 10) << "[RegistrationQueue] add bundle to list of delivered bundles: " << bundle.toString() << IBRCOMMON_LOGGER_ENDL;
                        } catch (const ibrcommon::Exception&) { }
                }

                dtn::data::MetaBundle Registration::RegistrationQueue::pop() throw (const ibrcommon::QueueUnblockedException)
                {
                        return _queue.take();
                }

                bool Registration::RegistrationQueue::has(const dtn::data::BundleID &bundle) const throw ()
                {
                        ibrcommon::MutexLock l(const_cast<ibrcommon::Mutex&>(_lock));
                        return _recv_bundles.has(bundle);
                }

                void Registration::RegistrationQueue::expire(const dtn::data::Timestamp &timestamp) throw ()
                {
                        ibrcommon::MutexLock l(_lock);
                        _recv_bundles.expire(timestamp);
                }

                void Registration::RegistrationQueue::abort() throw ()
                {
                        _queue.abort();
                }

                void Registration::RegistrationQueue::reset() throw ()
                {
                        _queue.reset();
                }

                void Registration::subscribe(const dtn::data::EID &endpoint)
                {
                        {
                                ibrcommon::MutexLock l(_endpoints_lock);

                                // add endpoint to the local set
                                _endpoints.insert(endpoint);
                        }

                        // trigger the search for new bundles
                        notify(NOTIFY_BUNDLE_AVAILABLE);
                }

                void Registration::unsubscribe(const dtn::data::EID &endpoint)
                {
                        ibrcommon::MutexLock l(_endpoints_lock);
                        _endpoints.erase(endpoint);
                }

                bool Registration::operator==(const std::string &other) const
                {
                        return (_handle == other);
                }

                bool Registration::operator==(const Registration &other) const
                {
                        return (_handle == other._handle);
                }

                bool Registration::operator<(const Registration &other) const
                {
                        return (_handle < other._handle);
                }

                void Registration::abort()
                {
                        _queue.abort();
                        _notify_queue.abort();

                        ibrcommon::MutexLock l(_wait_for_cond);
                        _wait_for_cond.abort();
                }

                const dtn::data::EID& Registration::getDefaultEID() const
                {
                        return _default_eid;
                }

                const std::string& Registration::getHandle() const
                {
                        return _handle;
                }

                void Registration::setPersistent(ibrcommon::Timer::time_t lifetime)
                {
                        _expiry = lifetime + ibrcommon::Timer::get_current_time();
                        _persistent = true;
                }

                void Registration::unsetPersistent()
                {
                        _persistent = false;
                }

                bool Registration::isPersistent()
                {
                        if(_expiry <= ibrcommon::Timer::get_current_time())
                        {
                                _persistent = false;
                        }

                        return _persistent;
                }

                bool Registration::isPersistent() const
                {
                        if(_expiry <= ibrcommon::Timer::get_current_time())
                        {
                                return false;
                        }

                        return _persistent;
                }

                void Registration::setFilterFragments(bool val)
                {
                        _filter_fragments = val;
                }

                ibrcommon::Timer::time_t Registration::getExpireTime() const
                {
                        if(!isPersistent()) throw NotPersistentException("Registration is not persistent.");

                        return _expiry;

                }

                void Registration::attach()
                {
                        ibrcommon::MutexLock l(_attach_lock);
                        if(!_detached) throw AlreadyAttachedException("Registration is already attached to a client.");

                        _detached = false;
                }

                void Registration::detach()
                {
                        ibrcommon::MutexLock l1(_wait_for_cond);
                        ibrcommon::MutexLock l2(_attach_lock);

                        _detached = true;

                        _queue.reset();
                        _notify_queue.reset();

                        _wait_for_cond.reset();
                }

                void Registration::processIncomingBundle(const dtn::data::EID &source, dtn::data::Bundle &bundle)
                {
                        // check address fields for "api:me", this has to be replaced
                        static const dtn::data::EID clienteid("api:me");

                        // create a new sequence number
                        bundle.relabel();

                        // if the relabeling results in a zero timestamp, add an ageblock
                        if (bundle.timestamp == 0)
                        {
                                // check for ageblock
                                try {
                                        bundle.find<dtn::data::AgeBlock>();
                                } catch (const dtn::data::Bundle::NoSuchBlockFoundException&) {
                                        // add a new ageblock
                                        bundle.push_front<dtn::data::AgeBlock>();
                                }
                        }

                        // set the source address to the sending EID
                        bundle.source = source;

                        if (bundle.destination == clienteid) bundle.destination = source;
                        if (bundle.reportto == clienteid) bundle.reportto = source;
                        if (bundle.custodian == clienteid) bundle.custodian = source;

                        // inject the bundle
                        dtn::core::BundleCore::inject(source, bundle);
                }
        }
}