ChannelSubscriber.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
 *   MLAB and NICR (or its successors, if any).
 *
 * IN NO EVENT SHALL "MLAB" OR "NICR" BE LIABLE TO ANY PARTY FOR DIRECT,
 * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF
 * THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF "MLAB" OR
 * "NICR" HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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 */

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

#include <utils/Bind.h>

#include <fw/AbstractChannel.h>
#include <fw/AbstractChannelSubscriber.h>

#include <fw/Status.h>


#ifndef _MIRA_CHANNELSUBSCRIBER_H_
#define _MIRA_CHANNELSUBSCRIBER_H_

namespace mira {


// forward declaration
template<typename T>
class ConcreteChannel;


template<typename T, typename ChannelRead>
class ChannelSubscriber : public AbstractChannelSubscriber
{
public:

    typedef ConcreteChannel<T> ChannelType;

public:

    ChannelSubscriber(DispatcherThread* dispatcher,
                      boost::function<void (ChannelRead)> invokeFn,
                      DiagnosticsModulePtr diagnosticsModule = NULL) :
        AbstractChannelSubscriber(dispatcher,diagnosticsModule),
        mChannel(NULL),
        mInvokeFn(invokeFn),
        mLastTimestamp(Time::invalid()) {}

    AbstractChannelPtr getChannel() { return mChannel; }

    void attachChannel(ChannelType* channel) {
        assert(mChannel==NULL);
        mChannel=channel;
    }

    virtual void detachChannel() {
        mChannel=NULL;
    }


    // implements IRunnable
    virtual void run(DispatcherThread* dispatcher)
    {
        if(!mEnabled)
            return;

        // prevents this Runnable instance from being destroyed while we are in here
        IRunnablePtr This = this->shared_from_this();

        assert(mChannel!=NULL);
        std::string channelid = mChannel->getID();

        try {

            // read the latest data from the Channel and call the invoke
            // function while securing that it was not already invoked with
            // the same data (timestamp)
            auto r = mChannel->read();
            Time n = r.getTimestamp();
            if (mLastTimestamp != n)
            {
                mLastTimestamp = n;
                mInvokeFn(r);
            }

            if(mDiagnosticsModule)
                mDiagnosticsModule->ok(channelid);
        }
        catch(Exception& ex) {
            if (!mDiagnosticsModule || mDiagnosticsModule->error(channelid,
                       ex.message(), "Exception while invoking subscriber")) {
                MIRA_LOG_EXCEPTION(ERROR,ex) << "Exception:\n";
            }
        }
        catch(std::exception& ex) {
            if (!mDiagnosticsModule || mDiagnosticsModule->error(channelid,
                        ex.what(), "Exception while invoking subscriber")) {
                MIRA_LOG_EXCEPTION(ERROR,ex) << "Exception:\n";
            }
        }
    }


private:

    ChannelType* mChannel;
    boost::function<void (ChannelRead)> mInvokeFn;
    Time mLastTimestamp;
};


}

#endif