ChannelReadInterval.h

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/*
 * Copyright (C) 2012 by
 *   MetraLabs GmbH (MLAB), GERMANY
 * and
 *   Neuroinformatics and Cognitive Robotics Labs (NICR) at TU Ilmenau, GERMANY
 * All rights reserved.
 *
 * Contact: info@mira-project.org
 *
 * Commercial Usage:
 *   Licensees holding valid commercial licenses may use this file in
 *   accordance with the commercial license agreement provided with the
 *   software or, alternatively, in accordance with the terms contained in
 *   a written agreement between you and MLAB or NICR.
 *
 * GNU General Public License Usage:
 *   Alternatively, this file may be used under the terms of the GNU
 *   General Public License version 3.0 as published by the Free Software
 *   Foundation and appearing in the file LICENSE.GPL3 included in the
 *   packaging of this file. Please review the following information to
 *   ensure the GNU General Public License version 3.0 requirements will be
 *   met: http://www.gnu.org/copyleft/gpl.html.
 *   Alternatively you may (at your option) use any later version of the GNU
 *   General Public License if such license has been publicly approved by
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 * IN NO EVENT SHALL "MLAB" OR "NICR" BE LIABLE TO ANY PARTY FOR DIRECT,
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 */

#ifndef _MIRA_CHANNELREADINTERVAL_H_
#define _MIRA_CHANNELREADINTERVAL_H_

#ifndef Q_MOC_RUN
#include <boost/shared_ptr.hpp>
#endif

#include <fw/ChannelReadWrite.h>

namespace mira {


template<typename T>
class ChannelReadInterval
{
    typedef ConcreteChannel<T>              ChannelType;
    typedef ChannelType*                    ChannelTypePtr;

    typedef typename ChannelType::Buffer    Buffer;
    typedef typename ChannelType::ValueType ValueType;
    typedef typename ChannelType::Slot      Slot;

public:
    typedef std::list<ChannelRead<T> > IntervalList;

    class const_iterator
    {
    public:

        // some STL conform typedefs that are needed for iterators
        typedef ptrdiff_t                          difference_type;
        typedef std::bidirectional_iterator_tag    iterator_category;
        typedef ValueType                          value_type;
        typedef const ValueType*                   pointer;
        typedef const ValueType&                   reference;

    private:

        friend class ChannelReadInterval;
        const_iterator(const typename IntervalList::const_iterator& i) : mIterator(i) {}

    public:

        const_iterator(const const_iterator& other) : mIterator(other.mIterator) {}

    public:

        operator ChannelRead<T>() const { return *mIterator; }

#if (__cplusplus >= 200710)
        explicit operator typename IntervalList::const_iterator() const { return mIterator; }
#else
        operator typename IntervalList::const_iterator() const { return mIterator; }
#endif

    public:

        reference operator*() const  { return (*(*mIterator)); }
        pointer   operator->() const { return &(*(*mIterator)); }

        const_iterator& operator++() {
            ++mIterator;
            return *this;
        }

        const_iterator operator++(int) {
            iterator tmp = *this;
            ++mIterator;
            return tmp;
        }

        const_iterator& operator--() {
            --mIterator;
            return *this;
        }

        const_iterator operator--(int) {
            iterator tmp = *this;
            --mIterator;
            return tmp;
        }

    public:

        bool operator==(const const_iterator& other) const {
            return mIterator==other.mIterator;
        }
        bool operator!=(const const_iterator& other) const {
            return mIterator!=other.mIterator;
        }

    private:

        typename IntervalList::const_iterator mIterator;
    };

    typedef const_iterator iterator;

public:

    const_iterator begin() const { return const_iterator(mInterval.begin()); }
    const_iterator end()   const { return const_iterator(mInterval.end());   }

public:

    std::size_t size() const { return mInterval.size(); }
    bool empty() const { return mInterval.empty(); }

public:

    ChannelReadInterval() : mChannel(NULL) {}

    ChannelReadInterval(ChannelTypePtr channel,
                        std::list<ChannelBufferBase::Slot*>& slotList) :
        mChannel(channel)
    {
        // add all slots of the interval to our own interval list
        // create one ChannelRead object per slot within the interval
        for(auto it=slotList.begin(); it!=slotList.end(); ++it)
        {
            // since the underlying channel buffer stores the slots starting
            // with the newest and ending with the oldest, we are moving
            // backward in time, however in our interval list we want to start
            // with the oldest element and end with the newest, so push_front
            // to revert the order.
            mInterval.emplace_front(channel, *it);
        }
    }

public:

    void finish() {
        mInterval.clear();
        mChannel = NULL;
    }

    const std::string& getChannelID() {
        static std::string emptyString;
        return mChannel!=NULL ? mChannel->getID() : emptyString;
    }

    std::string getTypename() const {
        return mChannel!=NULL ? mChannel->getTypename() : "";
    }

    TypeMetaPtr getTypeMeta() const {
        return mChannel!=NULL ? mChannel->getTypeMeta() : TypeMetaPtr();
    }

    Channel<T> getChannel();

private:

    void checkValid() const {
        if(mChannel==NULL)
            MIRA_THROW(XAccessViolation, "Trying to access ChannelReadInterval"
                       " that was not assigned with valid data");
    }

    ChannelTypePtr mChannel;
    IntervalList mInterval;
};


} // namespace

#endif