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//

// FIFOStrategy.h

//

// $Id: //poco/1.3/Foundation/include/Poco/FIFOStrategy.h#5 $

//

// Library: Foundation

// Package: Events

// Module:  FIFOStragegy

//

// Implementation of the FIFOStrategy template.

//

// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.

// and Contributors.

//

// Permission is hereby granted, free of charge, to any person or organization

// obtaining a copy of the software and accompanying documentation covered by

// this license (the "Software") to use, reproduce, display, distribute,

// execute, and transmit the Software, and to prepare derivative works of the

// Software, and to permit third-parties to whom the Software is furnished to

// do so, all subject to the following:

// 

// The copyright notices in the Software and this entire statement, including

// the above license grant, this restriction and the following disclaimer,

// must be included in all copies of the Software, in whole or in part, and

// all derivative works of the Software, unless such copies or derivative

// works are solely in the form of machine-executable object code generated by

// a source language processor.

// 

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT

// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE

// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,

// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

// DEALINGS IN THE SOFTWARE.

//

#ifndef  Foundation_FIFOStrategy_INCLUDED

#define  Foundation_FIFOStrategy_INCLUDED

#include "Poco/NotificationStrategy.h"

#include <map>

#include <list>

#include <memory>

namespace Poco {

template <class TArgs, class TDelegate, class TCompare> 

class FIFOStrategy: public NotificationStrategy<TArgs, TDelegate>

{

public:

        typedef std::list<TDelegate*>                    Delegates;

        typedef typename Delegates::iterator             Iterator;

        typedef typename Delegates::const_iterator       ConstIterator;

        typedef std::map<TDelegate*, Iterator, TCompare> DelegateIndex;

        typedef typename DelegateIndex::iterator         IndexIterator;

        typedef typename DelegateIndex::const_iterator   ConstIndexIterator;

        FIFOStrategy()

        {

        }

        FIFOStrategy(const FIFOStrategy& s)

        {

                operator = (s);

        }

        ~FIFOStrategy()

        {

                clear();

        }

        void notify(const void* sender, TArgs& arguments)

        {

                std::vector<Iterator> delMe;

                Iterator it    = _observers.begin();

                Iterator itEnd = _observers.end();

                for (; it != itEnd; ++it)

                {

                        if (!(*it)->notify(sender, arguments))

                        {

                                // schedule for deletion

                                delMe.push_back(it);

                        }

                }

                while (!delMe.empty())

                {

                        typename std::vector<Iterator>::iterator vit = delMe.end();

                        --vit;

                        delete **vit;

                        _observers.erase(*vit);

                        delMe.pop_back();

                }

        }

        void add(const TDelegate& delegate)

        {

                IndexIterator it = _observerIndex.find(const_cast<TDelegate*>(&delegate));

                if (it != _observerIndex.end())

                {

                        delete *it->second;

                        _observers.erase(it->second);

                        _observerIndex.erase(it);

                }

                std::auto_ptr<TDelegate> pDelegate(delegate.clone());

                _observers.push_back(pDelegate.get());

                bool tmp = _observerIndex.insert(std::make_pair(pDelegate.get(), --_observers.end())).second;

                poco_assert (tmp);

                pDelegate.release();

        }

        void remove(const TDelegate& delegate)

        {

                IndexIterator it = _observerIndex.find(const_cast<TDelegate*>(&delegate));

                if (it != _observerIndex.end())

                {

                        delete *it->second;

                        _observers.erase(it->second);

                        _observerIndex.erase(it);

                }

        }

        FIFOStrategy& operator = (const FIFOStrategy& s)

        {

                if (this != &s)

                {

                        for (ConstIterator it = s._observers.begin(); it != s._observers.end(); ++it)

                        {

                                add(**it);

                        }

                }

                return *this;

        }

        void clear()

        {

                for (Iterator it = _observers.begin(); it != _observers.end(); ++it)

                {

                        delete *it;

                }

                _observers.clear();

                _observerIndex.clear();

        }

        bool empty() const

        {

                return _observers.empty();

        }

protected:

        Delegates     _observers;     /// Stores the delegates in the order they were added.

        DelegateIndex _observerIndex; /// For faster lookup when add/remove is used.

};

} // namespace Poco

#endif