Mercurial > hg > orthanc-stone
diff Framework/Toolbox/ObserversRegistry.h @ 0:351ab0da0150
initial commit
author | Sebastien Jodogne <s.jodogne@gmail.com> |
---|---|
date | Fri, 14 Oct 2016 15:34:11 +0200 |
parents | |
children | ff1e935768e7 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Framework/Toolbox/ObserversRegistry.h Fri Oct 14 15:34:11 2016 +0200 @@ -0,0 +1,136 @@ +/** + * Stone of Orthanc + * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics + * Department, University Hospital of Liege, Belgium + * + * This program is free software: you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, either version 3 of the + * License, or (at your option) any later version. + * + * In addition, as a special exception, the copyright holders of this + * program give permission to link the code of its release with the + * OpenSSL project's "OpenSSL" library (or with modified versions of it + * that use the same license as the "OpenSSL" library), and distribute + * the linked executables. You must obey the GNU General Public License + * in all respects for all of the code used other than "OpenSSL". If you + * modify file(s) with this exception, you may extend this exception to + * your version of the file(s), but you are not obligated to do so. If + * you do not wish to do so, delete this exception statement from your + * version. If you delete this exception statement from all source files + * in the program, then also delete it here. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + **/ + + +#pragma once + +#include "../Orthanc/Core/OrthancException.h" + +#include <boost/noncopyable.hpp> +#include <boost/thread/mutex.hpp> +#include <set> + +namespace OrthancStone +{ + template < + typename Source, + typename Observer = typename Source::IChangeObserver + > + class ObserversRegistry : public boost::noncopyable + { + private: + struct ChangeFunctor : public boost::noncopyable + { + void operator() (Observer& observer, + const Source& source) + { + observer.NotifyChange(source); + } + }; + + typedef std::set<Observer*> Observers; + + boost::mutex mutex_; + Observers observers_; + bool empty_; + + public: + ObserversRegistry() : empty_(true) + { + } + + template <typename Functor> + void Notify(const Source* source, + Functor& functor) + { + if (empty_) + { + // Optimization to avoid the unnecessary locking of the mutex + return; + } + + if (source == NULL) + { + throw Orthanc::OrthancException(Orthanc::ErrorCode_ParameterOutOfRange); + } + + boost::mutex::scoped_lock lock(mutex_); + + for (typename Observers::const_iterator observer = observers_.begin(); + observer != observers_.end(); ++observer) + { + functor(**observer, *source); + } + } + + template <typename Functor> + void Notify(const Source* source) + { + // Use the default functor + Functor functor; + Notify(source, functor); + } + + void NotifyChange(const Source* source) + { + Notify<ChangeFunctor>(source); + } + + void Register(Observer& observer) + { + empty_ = false; + + boost::mutex::scoped_lock lock(mutex_); + observers_.insert(&observer); + } + + void Unregister(Observer& observer) + { + boost::mutex::scoped_lock lock(mutex_); + observers_.erase(&observer); + + if (observers_.empty()) + { + empty_ = true; + } + } + + bool IsEmpty() + { +#if 0 + boost::mutex::scoped_lock lock(mutex_); + return observers_.empty(); +#else + return empty_; +#endif + } + }; +}