Buffer.h

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/* ============================================================
 *
 * This file is a part of CCA project
 *
 * Copyright (C) 2011 by Arne Nordmann <anordman at cor-lab dot uni-bielefeld dot de>
 *
 * This file may be licensed under the terms of the
 * GNU Lesser General Public License Version 3 (the ``LGPL''),
 * or (at your option) any later version.
 *
 * Software distributed under the License is distributed
 * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
 * express or implied. See the LGPL for the specific language
 * governing rights and limitations.
 *
 * You should have received a copy of the LGPL along with this
 * program. If not, go to http://www.gnu.org/licenses/lgpl.html
 * or write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The development of this software was supported by:
 *   CoR-Lab, Research Institute for Cognition and Robotics
 *     Bielefeld University
 *
 * ============================================================ */

#pragma once

#include <string>
#include <sstream>
#include <iostream>
#include <exception>

#include <boost/shared_ptr.hpp>

#include "rsc/misc/langutils.h"

#include "cca/buffer/BufferException.h"

namespace cca {

using namespace rsc::misc;

template<class DATATYPE>
class Buffering {

public:

    typedef ::boost::shared_ptr<DATATYPE> DataPtr;

    Buffering() {
    }
    virtual ~Buffering() {
    }

    virtual DataPtr get() throw () = 0;

    virtual void add(DataPtr item) = 0;

    virtual bool empty() const = 0;

    virtual bool newItem() const = 0;

    virtual unsigned int size() const = 0;

    virtual void purge() = 0;

protected:
    Buffering(Buffering &buffer);

    void operator=(const Buffering&);
};

template<class DATATYPE>
class Buffer: public Buffering<DATATYPE> {

public:

    typedef ::boost::shared_ptr<Buffer<DATATYPE> > Ptr;

    typedef ::boost::shared_ptr<DATATYPE> DataPtr;

    Buffer(bool alwaysKeepLatest = true) :
            warm(false), numItems(0), keepLatest(alwaysKeepLatest),
                    newitem(false) {
    }

    virtual ~Buffer() {
    }

    virtual std::string print() const {
        std::ostringstream outstream(std::ostringstream::out);
        outstream.precision(3); // Precision when printing double values
        outstream << "<Buffer>" << std::endl;
        return outstream.str();
    }

    virtual DataPtr get() throw () = 0;

    virtual void add(DataPtr item) = 0;

    virtual bool empty() const {
        if (this->keepLatest) {
            return (!this->warm);
        } else {
            return (this->size() == 0);
        }
    }

    virtual bool newItem() const {
        return this->newitem;
    }

    virtual unsigned int size() const {
        return this->numItems;
    }

    virtual void purge() = 0;

protected:
    Buffer(Buffer &buffer);

    void operator=(const Buffer&);

    bool warm;

    unsigned int numItems;

    bool keepLatest;

    bool newitem;
};

}