ChannelInterval.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:
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 *   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
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 */

#ifndef _MIRA_CHANNELINTERVAL_H_
#define _MIRA_CHANNELINTERVAL_H_

#include <fw/ChannelReadWrite.h>
#include <fw/Framework.h>

namespace mira {


template <typename T>
class ChannelInterval
{
public:
    ChannelInterval() :
        mInterval(Duration::microseconds(0)),
        mLast(Time::unixEpoch())
    {}

    ChannelInterval(Duration iv) :
        mInterval(iv),
        mLast(Time::unixEpoch())
    {}

    Channel<T> subscribe(Authority& authority,
                         const std::string& channelID,
                         boost::function<void (ChannelRead<T>)> fn)
    {
        mFunction = fn;
        return authority.subscribe<T>(channelID, &ChannelInterval<T>::callback, this);
    }

    template<typename Class>
    Channel<T> subscribe(Authority& authority,
                         const std::string& channelID,
                         void (Class::*f)(ChannelRead<T>), Class* obj)
    {
        return subscribe(authority, channelID, boost::bind(f, obj, _1));
    }

    void setInterval(Duration iv)
    {
        mInterval = iv;
    }

    Duration interval() const
    {
        return mInterval;
    }

    Time last() const
    {
        return mLast;
    }

    void callback(ChannelRead<T> value)
    {
        const Time ts = Time::now();
        if (ts - mLast < mInterval || !mFunction)
            return;
        mFunction(value);
        mLast = ts;
    }

private:
    boost::function<void (ChannelRead<T>)> mFunction;
    Duration mInterval;
    Time mLast;
};


}

#endif